The metabolism of organic matter in the coastal regions of the ocean may significantly affect the oceaniccarbon budget. This paper describes the high percentage (30%) of oceanic oxidation that occurs in coastal areas and the impact of this metabolism on the carboncycle and climate of earth. Organic metabolism in the ocean appears to be a source of carbon dioxide release into the atmosphere. Oxidation in the coastal zone is of special interest, as it is likely influenced by anthropogenic activity. Recommendations for future research on this topic are proposed. 129 refs., 2 figs., 6 tabs.
Measurements of carbon metabolism, production and exchange along food webs suggest that large fractions of the organic matter produced on continental shelves must be exported to continental slopes. The annual loss of organic matter from continental shelf ecosystems is far greater than in the open ocean. If part of the loss of nearshore primary production has increased in those coastal zones where anthropogenic inorganic nutrient supplies have been consistently increasing since the industrial revolution, then burial and diagenesis of this material in slope depocentres could represent the missing BMTs of carbon in global CO/sub 2/ budgets.
Present and potential future changes to the global environment have important implications for marine pollution and for the air-sea exchange of both anthropogenic and natural substances. This report addresses three issues related to the potential impact of global change on the air-sea exchange of chemicals: Global change and the air-sea transfer of the nutrients nitrogen and iron. Global change and the air-sea exchange of gases. Oceanic responses to radiative and oxidative changes in the atmosphere. The deposition of atmospheric anthropogenic nitrogen has probably increased biological productivity in coastal regions along many continental margins. Atmospheric deposition of new nitrogen may also have increased productivity somewhat in mid-ocean regions. The projected future increases of nitrogen oxide emissions from Asia, Africa and South America will provide significant increases in the rate of deposition of oxidized nitrogen to the central ...
Only half of the carbon dioxide produced by burning fossil fuels stays in the atmosphere. It is thought that the oceans absorb the rest. To understand the world's climate it is necessary to know how the atmosphere, ocean and biosphere interact.
Objectives(i) Investigate the correlation between Antarctic sea-ice and equatorial sea-surface temperature anomalies in a realistically forced ocean model simulation of the last 50 years. (ii) Determine whether and how the enormous seasonal change in distribution of sea-ice modifies the seasonal cycle at the Equator. (iii) Determine the detailed pathways of wave propagation both in a historically-forced simulation and in response to realistic perturbations. (iv) Quantify the amplitude of the response i [continued...]DescriptionIt is well known that the equatorial ocean-atmosphere system plays a key role in global climate events such as the El Nino-Southern Oscillation (ENSO) phenomenon. There is now compelling evidence that changes in the Antarctic can strongly and quickly affect the equatorial ocean and the ENSO cycle. Observations demonstrate statistically significant correlations ...
Slowly, scientists come to realize that there are huge quantities of natural methan hydrates and their interest is awakened. Important questions in this connection are their possible use as future energy sources, the consequences of using methan hydrates on the climate, their integration into the carboncycle, the cementation of the continental slopes by gas hydrates and their stability and their role in some geological-biological-geochemical processes, especially in the marine area. Towards the end of the 20th century, the basic problems and applied problem scenarios, e.g. the foundation of production platforms dor petroleum and natural gas in gas-hydrate-containing sediments, was the reason for Japan, Canada, USA, China, Germany and India to install national research programmes of various sorts in order to deal with the problems of gas hydrates. Also international programmes like the INTEGRATED OCEAN DRILLING PROGRAM ...
One tiny marine plant makes life on Earth possible: phytoplankton. These microscopic photosynthetic drifters form the basis of the marine food web, they regulate carbon in the atmosphere, and are responsible for half of the photosynthesis that takes place on this planet.
SZI global distribution due to biogeochemical cycle in environment reservoirs has been studied. It is shown that during the operation of nuclear fuel cycle facilities and at a modern level of the decontamination factor the SZI concentration in some natural media (soil, the Earth biosphere, ocean mixing layer) will increase by 4-5 orders. Recommended gradual increase of the decontamnation factor in time for conserving the SZI concentration level not exceeding one order in comparison with modern one is given. At that to the end of the century the decontamination factor must be of an order of 1 x 10U in the case of SZI intake to the ocean mixing layer and of 1 x 10V in the case of its intake to the atmosphere.
"1"2"9I global distribution due to biogeochemical cycle in environment reservoirs has been studied. It is shown that during the operation of nuclear fuel cycle facilities and at a modern level of the decontamination factor the "1"2"9I concentration in some natural media (soil, the Earth biosphere, ocean mixing layer) will increase by 4-5 orders. Recommended gradual increase of the decontamnation factor in time for conserving the "1"2"9I concentration level not exceeding one order in comparison with modern one is given. At that to the end fof the centary the decontamination factor must be of an order of 1x10"4 in the case of "1"2"9I intake to the ocean mixing layer and of 1x10"5 in the case of its intake to the atmosphere.
The oceanic phytoplancton productivity may essentially influence the total rate of the atmospheric CO{sub 2} absorption by the ocean - that is, a considerable amount of CO{sub 2} will be taken-up in the 50 micrometers thick layer near the air-sea interface. Even if phytoplancton production constitutes only 5% of the total oceanic biota production, this will increase the rate of CO{sub 2} absorption more than twice compared with the present estimates. The reason is that metabolic activity of phytoplancton leads to the emergence in a thin scin (50 micrometers, the average size of phytoplancton cells) layer near the water surface of an additional minimum in the CO{sub 2} partial pressure profile and of an additional maximum of {Delta} {sup 13}C in the same area. These two extremums cannot be detected if the corresponding characteristics are averaged over any microscopic area in the well mixing layer that is more than 1 meter ...
The carboncycle is an important part of major biogeochemical cycles. Many techniques may be used to characterize carbon amounts and sources in the environment. Here we first review the most popular techniques for the determination of organic and inorganic carbon concentrations. Decarbonatation techniques are also reviewed in details since it is often an important part of organic carbon analysis. The second part of this paper addresses the use of carbon stable isotopes to characterize organic carbon sources and processes in the environment. An overview of general stable isotopes background and terminology is given as well as the most popular analytical techniques.
The use of global three-dimensional (3-D) models with satellite observations of CO2 in inverse modeling studies is an area of growing importance for understanding Earth s carboncycle. Here we use the GEOS-Chem model (version 8-02-01) CO2 mode with multiple modifications in order to assess their impact on CO2 forward simulations. Modifications include CO2 surface emissions from shipping (0.19 PgC yr 1), 3-D spatially-distributed emissions from aviation (0.16 PgC yr 1), and 3-D chemical production of CO2 (1.05 PgC yr 1). Although CO2 chemical production from the oxidation of CO, CH4 and other carbon gases is recognized as an important contribution to global CO2, it is typically accounted for by conversion from its precursors at the surface rather than in the free troposphere. We base our model 3-D spatial distribution of CO2 chemical production on monthly-averaged loss rates of CO (a key precursor and intermediate in the ...
The collision of the Earth with extra-terrestrial ice-volatile bodies is proposed as a mechanism to produce rapid changes in the geologic record. These bodies would be analogs of the ice satellites found for the Jovian planets and suspected for comets and certain low density bodies in the Asteroid belt. Five generic end-members are postulated: (1) water ice; (2) dry ice: carbon-carbon dioxide rich, (3) oceanic (chloride) ice; (4) sulfur-rich ice; (5) ammonia hydrate-rich ice; and (6) clathrate: methane-rich ice. Due to the volatile nature of these bodies, evidence for their impact with the Earth would be subtle and probably best reflected geochemically or in the fossil record. Actual boloids impacting the Earth may have a variable composition, generally some admixture with water ice. However for discussion purposes, only the effects of a dominant component will be treated. The general geological effects of such collisions, as a function of the ...
A 5 V glassy carbon capacitor stack was built consisting of four bipolar and two end-plate electrodes. More than 100,000 charging/discharging cycles were applied to test the stability of the double-layer capacitor. Low and high frequency resistances were measured as a function of the number of cycles. (author) 2 figs., 1 ref.
Microscopy and chemotaxonomy from HPLC analysis of phytoplankton pigments initiated in 2003 suggest that Noctiluca miliaris blooms are becoming more intense ...
Field studies among diverse biomes demonstrate that nitrogen concentration (% N) at leaf- and canopy-scales is strongly related to carbon uptake and cycling ...
This study investigates the turnover of polysaccharides by heterotrophic bacterioplankton in the northern Bay of Biscay, a productive marine system on the continental margin of the temperate Atlantic Ocean. Bacterial biomass production (BBP) near the surface ranged from 0.5 to 25.7 nmol C L?1 h?1 during small phytoplankton blooms in May and June that occurred after the main spring bloom. A direct relationship between BBP and total polysaccharides strongly suggests the dependence of bacterial growth on the availability of semi-labile organic matter. Concentrations of combined glucose as well as rate constants of extracellular glucosidase activity and glucose uptake were determined to estimate the actual carbon fluxes from bacterial polysaccharide turnover. Results reveal that ...
Spacecraft studies of the three terrestrial planets with atmospheres have made it possible to make meaningful comparisons that shed light on their common origin and divergent evolutionary paths. Early in their histories, all three apparently had oceans and extensive volcanism; Mars and Earth, at least, had magnetic fields, and Earth, at least, had life. All three currently have climates determined by energy balance relationships involving carbon dioxide, water and aerosols, regulated by solar energy deposition, atmospheric and ocean circulation, composition, and cloud physics and chemistry. This paper addresses the extent to which current knowledge allows us to explain the observed state of each planet, its planetology, climatology and biology, within a common framework. Areas of ignorance...
Decadal-scale climate variations over the Pacific Ocean and its surroundings are strongly related to the so-called Pacific decadal oscillation (PDO) which is coherent with wintertime climate over North America and Asian monsoon, and have important impacts on marine ecosystems and fisheries. In a near-term climate prediction covering the period up to 2030, we require knowledge of the future state of internal variations in the climate system such as the PDO as well as the global warming signal. We perform sets of ensemble hindcast and forecast experiments using a coupled atmosphere-ocean climate model to examine the predictability of internal variations on decadal timescales, in addition to the response to external forcing due to changes in concentrations of greenhouse gases and aerosols, volcanic activity, and solar cycle variations. Our results highlight that an initialization of the upper-ocean state ...
This study describes the construction of a simple mathematical model its validation through the simulation in transient state of a real cycle performed by a solar refrigerator based on physical adsorption using an activated carbon/methanol pair. The deviation from experimental results was 4% for the cycled mass of methanol, 2.2 % for maximum collector average temperature, and 3 x 10{sup -3} for the theoretical cycle coefficient of performance. Additional simulations of the same cycle inputting values representing different types and larger amounts of activated carbon showed the possibility of increasing the cycled methanol mass up to about 150%. (author) 26 refs., 16 figs., 9 tabs.
The key component for improving the energy efficiency and cycle life of the electrically rechargeable zinc-air battery is the bifunctional air electrode. The air electrodes described in this paper contained different types of carbon black as the substrate for the perovskite catalyst (La{sub 0.6}Ca{sub 0.4}CoO{sub 3}). Morphological and physical properties of the carbon substrates play an important role in enhancing the activity and stability of the bifunctional air electrode. Current-potential curves and cycle-life tests were applied in order to gather information on the activity and stability of these electrodes. (authors)
This site explains how temperature, pressure, and salinity work together to determine the density of ocean water. The three density layers of the ocean are described by means of text description and a graphic illustration.
Effects of dopant and coating carbon nanotube on anodic performance of Si were studied for metallic anode Li ion rechargeable battery with large capacity. Although the large Li intercalation capacity higher than 1500mAhg{sup -1} is exhibited on pure Si, it decreased drastically with increasing cycle number. Increasing the electrical conductivity by doping Cr or B is effective for increasing the initial capacity and the cycle stability of Si for Li intercalation. Coating semiconductive Si with the carbon nanotube by decomposition of hydrocarbon is effective for increasing the cycle stability, though the initial Li intercalation capacity slightly decreased. Conducting binder is also important for increasing the cycle stability and it was found that Li intercalation capacity higher than 1500mAhg{sup -1} can be sustained by using poly vinyliden fruolide. ...
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?
In this project we determined primary production and optical variability in the shelf and slope waters off of Cape Hatteras, N.C. These processes were addressed in conjunction with other Ocean Margins Program investigators, during the Spring Transition period and during Summer. We found that there were significant differences in measured parameters between Spring and Summer, enabling us to develop seasonally specific carbon production and ecosystem models as well as seasonal and regional algorithm improvements for use in remote sensing applications.
The Earth`s oceans, forests, agricultural lands and other natural areas absorb about half of the carbon dioxide emitted from anthropogenic sources. Terrestrial carbon sequestration strategies are immediately available to bridge the gap between current terrestrial sequestration capacity and high-capacity geologic sequestration projects available in 10 to 20 years. Terrestrial carbon sequestration strategies consist of implementing land management practices aimed at decreasing CO2 emitted into the atmosphere and developing advanced measurement tools to inventory and monitor carbon processes in soils and biota. In addition to atmospheric CO2 mitigation and carbon trading advantages, terrestrial carbon sequestration produces a variety of benefits which include reclamation of degraded lands, increased soil productivity, increased land value ...
Two important greenhouse gases, CO{sub 2} and CH{sub 4}, are closely connected to the carboncycling of wetlands. Although virgin wetlands are mostly carbon accumulating ecosystems, major proportion of the CO{sub 2} bound annually in photosynthesis is released back to the atmosphere. Main portion of the carboncycling in wetlands is quite fast while a small proportion of carbon diffusing from soil is released from organic matter, which may be ten thousand years old. Methane is formed in the anaerobic layers of wetlands, from where it is released gradually to the atmosphere. The decomposition in anaerobic conditions is very slow, which means that usually only a few percent of the annual carboncycling takes place as methane. Research on CO{sub 2} fluxes of different virgin and managed peatlands was the main topic of this ...
To apply the CO{sub 2} absorber at about 1000{sup o}C for integrated coal gasification combined cycle (IGCC) furnace, the reactions of calcium oxide and CO{sub 2} at high temperatures was examined. Calcium carbonate reacts with sodium hydrogen carbonate below 200{sup o}C and forms sodium-calcium complex carbonate. The sodium-calcium complex carbonate melts at 813{sup o}C, and the carbon dioxide absorption and discharge reversible reactions of calcium-oxide takes place via liquid at around 1000{sup o}C. Sintering of calcium oxide at high temperature has been successfully avoided by the addition of sodium.
Diel variations in rates of C export, sucrose-phosphate synthase (SPS) and sucrose synthase (SS) activity, and C reserves were investigated in Zostera marina L. (eelgrass) to elucidate the environmental...Full Text Available
This paper presents ionic conductivity results obtained with polymer electrolytes and also with propylene carbonate solutions. The domain of electrochemical activity of this salt has been determined using cycle volt-amperometry in propylene carbonate. Preliminary experiments on the stability of the polymer electrolyte with respect to the lithium electrode have been carried out for a possible subsequent use in lithium batteries. (J.S.) 4 refs.
Silicon/carbon composite anode materials were prepared by pyrolyzing the phenol-formaldehyde resin (PFR) mixed with silicon and graphite powders. Scanning electron microscopic (SEM) observation showed that the morphology stability of the composite electrodes can be retained during cycling. A structure evolution mechanism is proposed to illuminate the enhancement of cycleability of the composite electrode. The composite used as anode material for lithium ion batteries possesses a reversible capacity of over 700 mAh/g.
The carbon isotope profiles of shallow-marine carbonates from the Barremian-Aptian Kharaib and Shuaiba formations of the Arabian Gulf region range between 0.5 and 7{per_thousand} {delta}{sup 13}C PDB (Peedee belemnite). Systematic variations can be correlated with isotope profiles reported from Tethyan pelagic limestone sequences. The detailed correspondence between the isotopic signature of the relatively well-dated pelagic limestones and the poorly dated shallow-water limestones from the Arabian Gulf region suggests that global marine carbon isotope changes apparently affected deep-sea and shallow-water carbonate sediments similarly and at a similar time resolution. Although oxygen isotopes have been reset during diagenesis, carbon isotopes appear to have maintained their primary marine signature through time. No evidence has been found to connect carbon ...
Growing competitiveness of alternative manufacturing routes requires cost minimization in the production of drop forged components. The authors analyse the potential of medium carbon, vanadium microalloyed steels for drop forging. Laboratory and industrial experiments have been carried out emphasizing deformation and temperature cycles, strain rates and dwell times showing a typical processing path, associated mechanical properties and corresponding microstructures. The steels the required levels of mechanical properties on cooling after forging, eliminating subsequent heat treatment. The machinability of V-microalloyed steels is also improved when compared with plain medium carbon steels. (author)
This paper investigates various usages of natural gas (NG) as an energy source for different hydrogen production technologies. A comparison is made between the different methods of hydrogen production, based on the total amount of natural gas needed to produce a specific quantity of hydrogen, carbon dioxide emissions per mole of hydrogen produced, water requirements per mole of hydrogen produced, and a cost sensitivity analysis that takes into account the fuel cost, carbon dioxide capture cost and a carbon tax. The methods examined are the copper-chlorine (Cu-Cl) thermochemical cycle, steam methane reforming (SMR) and a modified sulfur-iodine (S-I) thermochemical cycle. Also, an integrated Cu-Cl/SMR plant is examined to show the unique advantages of modifying existing SMR plants with new h...
Spherical nanostructured Si/C composite was prepared by spray drying technique, followed by heat treatment, in which nanosized silicon and fine graphite particles were homogeneously embedded in carbon matrix pyrolyzed by phenol formaldehyde resin. Cyclic voltammetry tests showed two pairs of redox peaks corresponding to lithiation and delithiation of Si/C composite. The Si/C composite exhibited a reversible capacity of 635 mAh g"-"1 and good cycle performance used in lithium ion batteries. To improve cycle performance of this Si/C composite further, the carbon-coated Si/C composite was synthesized by the second spray drying and heat treatment processing. The cycle performance of carbon-coated Si/C composite was improved significantly, which was attributed to the formation of stable SEI passivation layers on the outer surface of carbon shell ...
This paper investigates various usages of natural gas (NG) as an energy source for different hydrogen production technologies. A comparison is made between the different methods of hydrogen production, based on the total amount of natural gas needed to produce a specific quantity of hydrogen, carbon dioxide emissions per mole of hydrogen produced, water requirements per mole of hydrogen produced, and a cost sensitivity analysis that takes into account the fuel cost, carbon dioxide capture cost and a carbon tax. The methods examined are the copper-chlorine (Cu-Cl) thermochemical cycle, steam methane reforming (SMR) and a modified sulfur-iodine (S-I) thermochemical cycle. Also, an integrated Cu-Cl/SMR plant is examined to show the unique advantages of modifying existing SMR plants with new hydrogen production technology. The analysis shows that the thermochemical Cu-Cl ...
This paper investigates various usages of natural gas (NG) as an energy source for different hydrogen production technologies. A comparison is made between the different methods of hydrogen production, based on the total amount of natural gas needed to produce a specific quantity of hydrogen, carbon dioxide emissions per mole of hydrogen produced, water requirements per mole of hydrogen produced, and a cost sensitivity analysis that takes into account the fuel cost, carbon dioxide capture cost and a carbon tax. The methods examined are the copper-chlorine (Cu-Cl) thermochemical cycle, steam methane reforming (SMR) and a modified sulfur-iodine (S-I) thermochemical cycle. Also, an integrated Cu-Cl/SMR plant is examined to show the unique advantages of modifying existing SMR plants with new hydrogen production technology. The analysis shows that the thermochemical Cu-Cl ...
The effect of accelerated thermal cycling on a joint between modified 9Cr-1Mo steel (Grade 91) and Alloy 800 welded with Inconel 82 and 182 filler material is discussed. This is part of a trimetallic transition joint involving Grade 91-Alloy 800-316LN austenitic stainless steel for steam generator application. It has been shown that, during thermal cycling following the typical post-weld tempering treatment at 760 deg. C for 2 h, no carbon diffusion occurs from the ferritic steel towards the weld metal. There is, in fact, a hardness increase at the ferritic steel/weld metal interface which is probably a result of work hardening. Carbon migration sets in only after unusually long post-weld heat treatments for 20 and 50 h at 760 deg. C followed by thermal cycling. Significantly, even under the most severe thermal cycling test conditions imposed, no cracking or ...
The Forsmark and the Laxemar investigation areas are examined by the Swedish Nuclear Fuel and Waste Management Co. for a possible construction of a deep repository for nuclear waste. In the case of a future leakage of waste, the radioactive isotopes could end up in the ecosystems above the repository. The fate of the radionuclides and their possible radiological impacts are then highly determined by ecosystem carboncycling. An important part of the carboncycling is the soil carbon effluxes, and in the investigation areas soil carbon effluxes have been examined with the closed chamber technique. This paper is divided into two parts. Firstly, there were problems with the equipment measuring the soil carbon dioxide efflux, and the first part is a description of the problem, how it was corrected and its possible causes. The second part is a ...
It has been understood that production of hydrogen from fossil and carbonaceous fuels with reduced CO{sub 2} emission to the atmosphere is key to the production of hydrogen-rich fuels for mitigating the CO{sub 2} greenhouse gas climate change problem. The conventional methods of hydrogen production from fossil fuels (coal, oil, gas and biomass) include steam reforming and water gas shift mainly of natural gas (SRM). In order to suppress CO{sub 2} emission from the steam reforming process, CO{sub 2} must be concentrated and sequestered either in or under the ocean or underground (in aquifers, or depleted oil or gas wells). Up to about 40% of the energy is lost in this process. An alternative process is the pyrolysis or the thermal decomposition of methane, natural gas (TDM) to hydrogen and carbon. The carbon can either be sequestered or sold on the market as a materials commodity or used as a fuel at a later date under less ...
In order to investigate the charging mode of an in-series assembly of lithium-carbon battery cells, a test has been performed on 5 commercial cells (18650) of 0.95 Ah nominal capacity. Results show that it is possible to cycle the cells at 80% of their output capacities during more than 2000 cycles. The management of the battery consists in maintaining a constant battery voltage as soon as a cell reaches its limit voltage during constant current charging. The initial dispersion of cells has been maintained practically constant during the cycling and the charge state of all cells has decreased progressively. (J.S.)
Research in concentrated thermal solar power plants of all types and, in particular, those based on central receiver, namely solar tower plants, has experienced great impetus in the last decade, reaching full commercial operation with the PS10 plant in Spain. In spite of previous demonstration plants testing different receivers and power cycle layouts, this first commercial power plant adopted a cavity receiver generating saturated steam and therefore penalising cycle efficiency in order to gain plant reliability. According to the experience gained, if a competitive Levelised Cost of Electricity is to be reached, capital and maintenance costs must be reduced and efficiencies must be increased. To achieve these goals, modifying the power cycle is deemed essential, whether using superheated ...
In the study, wind data from the Comprehensive Ocean-Atmosphere Data Set (COADS) are used to determine atmospheric circulation changes which are empirically associated with the air temperature changes. Some understanding of the natural processes which produce climate change is anticipated from the study of these associations. Systematic changes of wind in US coastal regions with periods of climate warming and cooling suggest circulation changes, in addition to carbon dioxide-controlled radiation effects, could produce the climate changes indicated by air temperature. A statistical procedure for analyses of COADS was used to determine decade-period vector wind-field differences from the COADS record period. The statistical procedure for these analyses is explained and the wind differences are compared to summaries of mid-Atlantic coast island-station observations.
Carbons derived from the phase separation of polyacrylonitrile/solvent mixtures were investigated as lithium intercalation anodes for rechargeable lithium-ion batteries. The carbon electrodes have a bulk density of 0.35-0.5 g/cm{sup 3}, relatively low surface areas (< 10 m{sup 2}/g), and micron-size cells. Pyrolysis temperature influences the reversible lithium intercalation and the irreversible capacity (associated with the formation of the passivating layer). Carbon electrodes pyrolyzed at 600{degrees}C have first-cycle capacity as high as 550 mAh/g as well as large irreversible capacity, 440 mAh/g. Electrodes prepared at 1050{degrees}C have reversible capacities around 270 mAh/g with relatively lower capacity losses (120 mAh/g). Doping the organic precursors with phosphoric acid, prior to pyrolysis at 1050{degrees}C, leads to carbon electrodes with reversible capacities as ...
A highly efficient integrated energy conversion system is built based on a methane catalytic decomposition reactor (MCDR) together with a direct carbon fuel cell (DCFC) and an internal reforming solid oxide fuel cell (IRSOFC). In the MCDR, methane is decomposed to pure carbon and hydrogen. Carbon is used as the fuel of DCFC to generate power and produce pure carbon dioxide. The hydrogen and unconverted methane are used as the fuel in the IRSOFC. A gas turbine cycle is also used to produce more power output from the thermal energy generated in the IRSOFC. The output performance and efficiency of both the DCFC and IRSOFC are investigated and compared by development of exact models of them. It is found that this system has a unique loading flexibility due to the good high-loading property of ...
We examined, using thermo analytical methods, the effects of 2000 deg. C heat-treated graphite powders and heating rate of cure after impregnation on the thermal stability and carbon yield of furfuryl alcohol, which is frequently used not only as an impregnation but also as a matrix precursor for carbon fiber-reinforced carbon composites. It was founded that the addition of 30 wt%. graphite powders of furfuryl alcohol and the heating rate 35 deg. C/min showed the highest thermal stability of furfuryl alcohol/graphite powder mixture. The carbon yield above 1000 deg. C was enhanced more than 10% in comparison with the absence of graphite powders. It would be expected that this result can contribute to some extent to reduce the repeating number of processing cycle (carbonization {yields} impregnation {yields} cure {yields} re-carbonization) ...
SnO{sub 2}-carbon nanotube (CNT) composite sheets are synthesized using poly(vinylpyrrolidone) to uniformly load a monolayer of SnO{sub 2} nanoparticles onto the surfaces of CNTs and CNT bundles within cross-stacked CNT sheets. When they are used as high-capacity (over 850 mA h g{sup -1}) and binder-free anodes in rechargeable lithium-ion batteries, they exhibit good cycle performance. (Abstract Copyright [2009], Wiley Periodicals, Inc.)
The Formerly Utilized Sites Remedial Action Program (FUSRAP) is to evaluate the radiological conditions at former MED-US AEC sites. Purpose of the Ocean FUSRAP program is to assess the feasibility of ocean disposal of FUSRAP waste which contains trace natural radioactive materials. This paper presents soil characterization information on the Middlesex, NJ, Sampling Plant site, and reports preliminary ocean dispersion calculations. (DLC)
A series of speeches is presented which cover political aspects of ocean energy, legislation, the status of the DOE Ocean Energy Program, the Maritime Administration OTEC Support Program. Six workshop reports are given covering ocean energy technology and systems concepts, power systems concepts, environmental developments, energy transfer and utilization, construction and test capabilities, and industry development. (LEW)
In this book are found technical and scientific papers on the main works of the Direction of the Fuel Cycle (DCC) in France. The study fields are: the up-side of the nuclear fuel cycle with theoretical studies (plasma simulation) and technological developments and instrumentation (lasers diodes, carbides plasma projection, carbon 13 enrichment); the down-side nuclear fuel cycle with theoretical studies (ion Eu{sup 3+} complexation simulation, decay simulation, uranium and plutonium diffusion study, electrolyser operating simulation), scenario studies ( recycling, wastes management), experimental studies; dismantling and cleaning (soils cleaning, surface-active agent for decontamination, fault tree analysis); analysis with expert systems and mass spectrometry. (A.L.B.)
Alloy 800 from three different commercial heats have been continuously cycled and cycled with a hold period at 922/sup 0/K. The starting microstructures of these heats reflects an inherently wide spectrum of possibilities for Alloy 800. The amounts and morphologies of the TiC and M/sub 23/C/sub 6/ carbides are different among the heats. During cycling, M/sub 23/C/sub 6/ forms intragranularly in a solution annealed heat. This precipitation contributes to the cyclic hardening. Both mill annealed heats of Alloy 800 are stable to carbide precipitation during cycling. The heat with the lower carbon content formed ..gamma..' during cycling but the volume fraction was too low to contribute to hardening. The inclusion of hold periods caused the dislocation substructure to become more diffuse in the mill annealed heats. The cyclic hardening was enhanced with the ...
Uniaxial low-cycle fatigue and creep-fatigue tests have been carried out on hollow alloy 800 specimens that were either filled with air or with a molten mixture of sodium nitrate, potassium nitrate and an oxidizer. Low-cycle fatigue tests were carried out at 1200/sup 0/F and 650/sup 0/F by cycling the strain continuously between equal mangitude of tensile and compressive values at a rate of 4 x 10/sup -3/sec/sup -1/ until failure. The creep-fatigue tests were carried out at 1200/sup 0/F. The loading cycle differed from that of low-cycle fatigue testing only in the imposition of a hold at the peak compressive strain in each cycle. Cracks always initiated on the inner surface of the hollow specimen, and therefore, corrosive effects on crack propagation and initiation were controlled by the environment within the specimen cavity. In common with tests carried out ...
The purpose of the Ocean FUSRAP Program, which began in March 1981, is to assess the technical, environmental, and institutional feasibility of disposing, in the ocean and on the ocean floor, of FUSRAP waste which contains traces of natural radioactive materials. The initial planning has focused on the Middlesex, New Jersey, Sampling Plant site and surrounding properties, which contain on the order of 100,000 metric tons of material. The Belgian Congo uranium ore and other uranium ores used by the United States were handled at the sampling plant site and have since been removed.
This paper presents the isothermal characteristics of methanol onto two specimens of activated carbons namely Maxsorb III and Tsurumi activated charcoal. Dubinin Raduskevich (D-R) equation is used to correlate the adsorption isotherms and to form the pressure-temperature-concentration diagram for both of the assorted pairs. Experimental results show that the maximum adsorption capacity of Maxsorb III/methanol pair is 1.76 times that of activated charcoal/methanol pair. Employing a time-independent mathematical model, the performance of adsorption cooling cycle using Maxsorb III/methanol and activated charcoal/methanol pairs has been studied and compared with that of three other types of carbon based adsorbent/methanol pairs. Theoretical calculations show the superiority of Maxsorb III/methanol pair for both of air-conditioning and ice-making applications. (author)
The lithium carbon batteries studied in this paper use plasticized polymer electrolytes made with passive polymer matrix swollen by a liquid electrolyte with a high ionic conductivity (> 10{sup -3} S/cm at 25 deg. C). The polymers used to prepare the gels are polyacrylonitrile (PAN) and vinylidene poly-fluoride (PVdF). The electrochemical and physical properties of these materials are analyzed according to their composition. The behaviour of solid electrolytes with different materials of lithium ion insertion (graphite and LiNiO{sub 2}) are studied and compared to liquid electrolytes. The parameters taken into account are the reversible and irreversible capacities, the cycling performance and the admissible current densities. Finally, complete lithium ion batteries with gelled electrolytes were manufactured and tested. (J.S.) 2 refs.
Studies of the adsorption of oxides of sulfur and nitrogen, and their coadsorption, on black carbon in the form of n-hexane soot have been carried out by microgravimetry, EPR and FTIR spectroscopy over a wide range of experimental conditions. The mechanisms of adsorption of O{sub 2} and NO{sub 2} are entirely different, as reflected by adsorption isotherms, the behavior of carbon`s unpaired electrons, the spectral features of surface species formed, mass changes during adsorption-desorption cycles, and an essential lack of competition for surface sites. Significant effects of temperature, water, SO{sub 2} and NO{sub 2} concentration, O{sub 2}, simulated solar radiation, and the presence of trace metals, have been observed and interpreted.
This report discusses the activities of two major groups of forest soil microorganisms, the bacteria and the fungi. Special attention is paid to their participation in the decay of major forest litter substrates, including leaves, branches and roots. The influence of bacteria and fungi in symbiotic associations with woody plant roots upon the cycles of carbon and nitrogen is described. The impacts of certain forest mamagement alternatives are assessed in terms of the creation of elimination of suitable environments for the activity of soil microorganisms. A bibliography is included. 507 refs., 1 tab.
The low cycle fatigue testing was carried out to provide a basis for comparison of the behavior of the two kinds of Alloy 800 (low carbon Alloy 800 and high carbon Alloy 800H). The testing was done at temperatures of 500"0C and 650"0C either with or without hold. The results obtained were as follows: (1) At 650"0C, the low-cycle fatigue life was essentially the same for the two alloys on the basis of strain amplitude, but Alloy 800H had a longer life on the basis of stress amplitude. (2) At 500"0C, the two alloys exhibited longer lives than at 650"0C, with Alloy 800 exhibiting 2-3 times longer life than Alloy 800H when compared on the basis of plastic strain range. At this temperature the stress range showed the maximum for Alloy 800H. (3) When a creep effect was introduced either by way of a hold time or a reduced frequency, Alloy 800 exhibited a greater reduction in life than in Alloy 800H. (4) At ...
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 ...
Modern combined cycle power plants with natural gas as the only fuel reach efficiencies of up to 58% for electric power generation. Nevertheless the reserves of natural gas are more limited compared to the reserves of coal. Therefore possibilities should be investigated to use coal for such plants also. One concept, that combines the use of coal in a combined cycle application with high efficiencies is examined in this paper. According to this concept the exhaust gas of the gas turbine (vitiated air) is the combustion air for the pulverised coal combustion, that takes place in the bottoming steam generator. Due to the low oxygen content of the vitiated air the burnout of the coal may be incomplete. In order to avoid the incomplete combustion of the coal and the resulting decrease of the efficiency of the plant and possible emission problems, a catalyst, that converts carbon monoxide and unburnt carbon ...
Modern combined cycle power plants with natural gas as the only fuel reach efficiencies of up to 55% for electric power generation. Nevertheless the reserve of natural gas is more limited compared to the reserve of coal. Therefore possibilities should be investigated to use coal for such plants also. One concept, that combines the use of coal in a combined cycle application with high efficiencies is examined in this paper. According to this concept the exhaust gas of the gas turbine (vitiated air) is the combustion air for the pulverized coal combustion, that takes place in the bottoming steam generator. Due to the low oxygen content of the vitiated air the burnout of the coal may be incomplete. In order to avoid the incomplete combustion of the coal and the resulting decrease of the efficiency of the plant and possible emission problems, a catalyst, that converts carbon monoxide and unburnt carbon to ...
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 ...
The basic feature in the functional ecology of any mire ecosystem is retardation of the effective decay of organic material resulting in a conspicuous accumulation of plant debris as peat overtime. The carbon accumulation process is slow, and climatic change may have an impact on the carboncycle of peatlands, therefore, it has been of interest to study the rate of carbon accumulation by geological methods from dated peat strata. The approach is hampered by several facts. First, the mires vary enormously as to their vegetation and hydrology and hence their production and decay properties. It follows that a great number of study sites are needed. Second, the peat in mires expands both vertically and laterally, and this requires a spatial reconstruction of carbon accumulation within a mire basin. Third, simple geological methods cannot account for the actual rate of ...
The need for a hydrogen economy is driven by increasing fuel prices, depleting oil reserves and uncertainty over supplies, and concerns about global warming and environmental pollution. Alternative methods to portable energy sources such as fossil fuels are being developed that are more efficient and carbon-emission-neutral. A prospective method is to produce hydrogen as an energy carrier. This paper presented a study on the degradation of materials under conditions of the sulphur-iodine (SI) thermochemical cycle. The paper provided background information on the study and presented a schematic of the SI cycle. A literature review was presented along with materials selected, such as refractory metals, reactive metals, superalloys, glassy metals, ceramics, cermets, polymers, composites, and coatings. The experimental method was then described. A capsule method was developed to rapidly quantify the decomposition rate of the ...
The physicochemical forms and partitioning of corrosion products released from stainless steel upon exposure to selected environmental conditions is the subject of this investigation. This report describes the influence of calcareous sediment on the rate of release and fate of corrosion products produced when neutron-activated stainless steel specimens were exposed to a Globigerina ooze taken from the Northeast Pacific Ocean. The calcareous ooze used in this study consists largely of planktonic formanifera tests and was found to be about 90% CaCO_3. The trace metal content of this sediment was typical of average deep-sea carbonate sediments, and the ratios of trace elements to Ti were not remarkably different from a coastal clayey silt or a Northeast Pacific pelagic red clay. Most (>80%) of the trace metals extracted by sequential chemical treatment were associated with reductant-soluble materials, i.e., amorphous Mn and Fe oxides, or were ...
period T. Also shown is the returned chirp from a specular reflector at ...... algorithms is a Brown (1977) model of the return waveform, which assumes a ...... Townsend, W.F., 1980: An initial assessment of the performance achieved by ...
The world's oceans contain a complex mixture of micro-organisms that are for the most part, uncharacterized both genetically and biochemically. We report here a metagenomic study of the marine planktonic...Full Text Available
The Subseabed Disposal Program has recently completed a 30-day, 0.286-scale laboratory simulation of an In Situ Heat Transfer Experiment (ISHTE), scheduled for eventual deployment in the deep ocean 600 nautical miles north of Hawaii. 10 figures.
The Subseabed Disposal Program has recently completed a 30-day, 0.286-scale laboratory simulation of an In Situ Heat Transfer Experiment (ISHTE), scheduled for eventual deployment in the deep ocean 600 nautical miles north of Hawaii. 10 figures.
The report gives an initial assessment of the feasibility of disposing of flue gas desulfurization wastes in mines and in the ocean. The purpose of the assessment was to evaluate environmental, technical, regulatory, and economic aspects of the use of such disposal sites. Availab...
A newly carbon-doped Lithium titanate (Li4Ti5O12/C) spinel-type composite material was routinely prepared by a simple solid-state reaction method using carbonization of polyacrylonitrile (PAN) as carbon source in an inert atmosphere. Impedance measurement shows that the resistance of the composite electrode is substantially lower than that of the pure one. Electrochemical performances of the prepared materials were investigated. Results indicate that the composite materials obtained with 10wt.% PAN shows relatively higher specific capacity, better cycling and higher rate performance. The first discharge specific capacity of 158mAhg^-^1, 138mAhg^-^1, and 121mAhg^-^1 were obtained at 0.2C rate, 1/3C rate, and 3C rate at room temperature, respectively. And it was also found that tap density o...
A highly efficient integrated energy conversion system is built based on a methane catalytic decomposition reactor (MCDR) together with a direct carbon fuel cell (DCFC) and an internal reforming solid oxide fuel cell (IRSOFC). In the MCDR, methane is decomposed to pure carbon and hydrogen. Carbon is used as the fuel of DCFC to generate power and produce pure carbon dioxide. The hydrogen and unconverted methane are used as the fuel in the IRSOFC. A gas turbine cycle is also used to produce more power output from the thermal energy generated in the IRSOFC. The output performance and efficiency of both the DCFC and IRSOFC are investigated and compared by development of exact models of them. It is found that this system has a unique loading flexibility due to the good high-loading property of DCFC and the good low loading property of IRSOFC. The effects of temperature, pressure, current ...
Abstract A critical aspect of reestablishing a self-sustaining Jarrah (Eucalyptus marginata) forest ecosystem to bauxite-mined areas is to ensure that vital ecosystem functions such as litter decomposition and nutrient cycling are returned. Significant research has been undertaken over the past 20 years relating to litter decomposition and nutrient cycling. Studies have shown that litter accumulates rapidly in restored areas (1-4 ton ha-1 yr-1) and the accumulated litter tends to be richer in nitrogen due to intentionally elevated densities of nitrogen-fixing species. This leads to a lower (carbon:nitrogen) C:N ratio (60:1 compared to 130:1 in unmined forest) that may promote mineralization of organic N to inorganic forms in restored areas. The major nutrient store in the unmined forest is...
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 to the wide availability of natural gas. 34 refs., 5 figs., 2 ...
... Studies People Projects Opportunities Framework Critical Sectors Development Goals Geographic Region Geographic Scale Research Themes Printer-Friendly Center for Ocean Solutions Early Career Fellowship Program Location: Stanford, California Source: The Center for Ocean Solutions (“Ocean Solutions”) seeks one or more recent graduates who have received a JD, MBA or PhD in the natural, physical or social sciences in the last five years, and who ...
''Climates of the Oceans'' deals with the atmosphere over the world oceans and provides a treatment not only of the climatic elements such as temperature, pressure, wind, precipitation etc., but also of the circulation of the atmosphere and its changes throughout the year. The connection between sea and overlying air is examined through studies of the water and heat balance. Numerous maps and tables illustrate the elements and their fluctuations over the water and on islands and coasts.
Soil acidification via acid precipitation is recognized to have detrimental impacts on forest ecosystems, which is in part associated with the function of ethylene released from the soil. However, the impacts of acidification on the cycling of ethylene in forest soils have not been fully taken into consideration in global change studies. Forest topsoils (0?5 cm) under four temperate forest stands were sampled to study the effects of a pH change on the emissions of ethylene and carbon dioxide from the soils and concentrations of dissolved organic carbon (DOC) released into the soils. Increasing acidification or alkalinization of forest soils could increase concentrations of DOC released into the soils under anoxic and oxic conditions. The ethylene emission from these forest topsoils could s...
Abstract A large remaining source of uncertainty in global model predictions of future climate is how ecosystem carbon (C) cycle feedbacks to climate change. We conducted a field manipulative experiment of warming and nitrogen (N) addition in a temperate steppe in northern China during two contrasting hydrological growing seasons in 2006 [wet with total precipitation 11.2% above the long-term mean (348 mm)] and 2007 (dry with total precipitation 46.7% below the long-term mean). Irrespective of strong intra- and interannual variations in ecosystem C fluxes, responses of ecosystem C fluxes to warming and N addition did not change between the two growing seasons, suggesting independence of warming and N responses of net ecosystem C exchange (NEE) upon hydrological variations in the temperate ...
High energy consumption and the world population increase will lead to a shrinking use of fossil fuels. The combustion of Fossil fuel leads to the increase of carbon dioxide concentration in the atmosphere which leads to the probable increase of global warming. Therefore, concerns about carbon dioxide emissions may discourage widespread dependence on fossil fuels and encourage the development and use of renewable energy systems employing a variety of technologies Renewable energy systems have themselves an environmental impact. Land use and material employed are two areas that may have an adverse impact to the positive environmental picture of the renewable energy systems. The objective of this paper is to analyze these impacts with the use of a very powerful tool, the Life Cycle Assessment. (author)
This task within the EU R and D for ITER was aimed at the development of basic manufacturing solutions for the high heat flux plasma facing components such as the divertor targets, the baffles and limiters. More than 50 representative small-scale mock-ups have been manufactured with beryllium, carbon and tungsten armour using various joining technologies. High heat flux testing of 20 of these mock-ups showed the carbon mono-blocks to be the most robust solution, surviving 2000 cycles at absorbed heat fluxes of up to 24 MW m{sup -2}. With flat armour tiles rapid joint failures occurred at 5-16 MW m{sup -2} depending on joining technology and armour material. These test results serve as a basis for the selection of manufacturing options and materials for the prototypes now being ordered. (orig.) 11 refs.
Nanocomposites comprising nanocrystal silicon (Si), disordered carbon (DC), and multi-walled carbon nanotubes (MWCNTs) - denoted as Si/DC/MWCNTs - have been prepared by pyrolyzing the phenol-formaldehyde resin (PFR) mixed with Si and MWCNTs. This nanocomposite anode material showed a discharge capacity of 1216 mAh/g in the first cycle, and a charge capacity of 711 mAh/g after 20 charge-discharge, much higher than that of Si/DC composite. It can be observed that Si particles wrapped in MWCNTs were homogeneously embedded into the matrix of the DC. The improved electrochemical performance is hypothesized to be mainly attributed to the morphology stability of the composite due to the excellent resiliency and distinct electric conductivity of the MWCNTs.
An efficient method of hydrogen storage in nano-porous carbons is its reversible sorption by electrochemical decomposition of a KOH water solution [1-3] 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 desorpt(TPD). The nature of the hydrogen/carbon interaction was studied by electrochemical analysis at different temperatures. The TPD experiments ...
Carbon nanofiber (CNF) supported cobalt oxide composites as high-capacity anode materials were prepared through a facile, effective method for potential use in rechargeable lithium-ion batteries. The effects of the calcining temperature on the crystallinity, grain size, specific surface area of Co{sub 3}O{sub 4} and phase transformation from Co{sub 3}O{sub 4} to CoO were studied in detail. Both the specific surface area and CNF content in CNF-cobalt oxide composites strongly affect the electrochemical performance of these series composites. The CNF-Co{sub 3}O{sub 4} composite with 24.3% CNF pyrolyzed at 500 deg. C in Ar shows an excellent cycling performance, retaining a specific capacity of 881 mAh g{sup -1} beyond 100 cycles. Homogeneous deposition and distribution of nanosized Co{sub 3}O{sub 4} particles on the surface of CNF can stabilize the electronic and ionic conductivity as well as the morphology of Co{sub 3}O{sub ...
Carbon nanofiber (CNF) supported cobalt oxide composites as high-capacity anode materials were prepared through a facile, effective method for potential use in rechargeable lithium-ion batteries. The effects of the calcining temperature on the crystallinity, grain size, specific surface area of Co{sub 3}O{sub 4} and phase transformation from Co{sub 3}O{sub 4} to CoO were studied in detail. Both the specific surface area and CNF content in CNF-cobalt oxide composites strongly affect the electrochemical performance of these series composites. The CNF-Co{sub 3}O{sub 4} composite with 24.3% CNF pyrolyzed at 500{sup o}C in Ar shows an excellent cycling performance, retaining a specific capacity of 881 mAh g{sup -1} beyond 100 cycles. Homogeneous deposition and distribution of nanosized Co{sub 3}O{sub 4} particles on the surface of CNF can stabilize the electronic and ionic conductivity as well as the morphology of Co{sub 3}O{sub ...
An electrolyte for high voltage lithium metal anode cells must simultaneously satisfy at least the following requirements; (i) high cycling efficiency on the lithium metal anode; (ii) higher oxidation potential than the charging voltage, and (iii) high specific conductivity. We have examined various electrolytes for lithium metal anode cells using a high voltage cathode, LiMn{sub 1.9}Co{sub 0.1}O{sub 4}. Of the electrolytes resistant to high voltage that we used, a system containing 60 to 90 vol.% of dimethyl carbonate (DMC) mixed with ethylene carbonate (EC) and 1.0 M lithium hexafluorophosphate (LiPF{sub 6}) provided the best cycling efficiency on a lithium metal anode, as well as a high specific conductivity around 10 mS cm{sup -1} at 20 C. (orig.)
In this study, the exhaust gas from a common-rail direct injection diesel engine was investigated both upstream and downstream warm-up catalytic converters (WCC). Three different types of ultra-low sulfur fuels (ethanol-diesel blend, ethanol-diesel blend with cetane improver and pure diesel) were tested in this study. The objective of the work was to study the engine performance and the formation of THC (total hydro carbon), CO (carbon monoxide), NO{sub x} (nitrogen oxides), smoke and PM (particulate matters) when using these fuels. THC and CO emissions of the ethanol-diesel blend fuels were slightly increased, and about 50-80% mean conversion efficiencies of THC and CO on catalysts were achieved in the ECE R49 13-mode cycle. Smoke was decreased by more than 42% in the entire ECE 13-mode cycles. From the measurement of scanning mobility particle sizer (SMPS) for the particle size range of 10-385 nm, the ...
Basic properties and battery performances of the novel high temperature stable lithium salt (Li{sub 2}B{sub 12}F{sub 12}, Dilithium Dodecafluorododecaborate; Li{sub 2}DFB) were studied using a Mn-based cathode and anode composed of a hard carbon and graphite mixture. The effect of co-solvents (mainly linear carbonate in electrolyte formulation of PC/EC/co-solvent (5/30/65 vol% mixture)) on conductivity, viscosity, charge-discharge capacities, rate performance, temperature performance, cycle life and storage life at 60 C was investigated. Conductivity of Li{sub 2}DFB electrolyte increased with reducing its viscosity by changing co-solvent and increasing the volume of the higher dielectric solvent. Li{sub 2}DFB electrolytes showed comparable discharge capacity and columbic efficiency against LiPF{sub 6} electrolyte. Li{sub 2}DFB electrolytes improved the storage life and cycle life of a Mn-based cell at ...
'The interactions of carbon tetrachloride with strongly basic oxides and hydroxides have been studied by several techniques in order to understand the surface reactions and the subsequent bulk reactions that result in the destruction of the chlorinated hydrocarbon. Emphasis has been placed on understanding the surface phases, as well as the bulk phases, that are present during these transformations. As a result of the study with barium oxide, a reaction cycle has been demonstrated that may have practical significance in the removal of chlorinated hydrocarbons.'
The overall purpose of this research was to evaluate the independent and interactive effects of elevated levels of CO{sub 2} and O{sub 3} on tree leaf litter quality and decomposition. This research was conducted at the Aspen FACE (Free Air CO{sub 2} Enrichment) facility near Rhinelander, Wisconsin. This research comprised one facet of a larger project assessing how CO{sub 2} and O{sub 3} pollutants will alter carbon sequestration and nutrient cycling in north temperate forest ecosystems.
The basic principle of the green building philosophy is to design buildings that consider environmental performance. Residential and commercial buildings in Canada consume about 30 per cent of the total secondary energy use and are responsible for approximately 29 per cent of carbon dioxide equivalent greenhouse gas emissions and many other wastes. An optimization model was developed which minimizes life cycle cost and life cycle environmental impact. The model distinguishes different energy sources and incorporates their impacts, such as resource depletion, global warming and acidification. The model also considers design variables such as window type, orientation, building orientation, window-to-wall ratio, wall type and roof type. The model can be used to identify optimum green building designs for given conditions. The model uses expanded cumulative exergy consumption as the indicator for life cycle ...
The economic feasibility of using granular activated carbon (GAC) to remove organic contaminants from industrial and municipal wastewater is contingent upon its reuse during multiple adsorption-regeneration cycles. The most common process for the regeneration of GAC is the thermal method. Drawbacks associated with thermal regeneration include a 5--10% loss of carbon due to oxidation and attrition, a decrease in adsorption capacity, and high energy costs. The purpose of this study was to investigate the regeneration of GAC using hydrothermal technology. Phenol contaminated and non-contaminated GAC samples were regenerated using supercritical water (411 deg C and 26.2 MPa) with dissolved oxygen concentrations of 0 mg/L, 5 mg/L, and 100 mg/L. For comparative purposes, GAC was regenerated using subcritical water (300 deg C and 12.4 MPa) with a dissolved oxygen concentration of 5 mg/L. Regenerated GAC samples were evaluated in ...
Studies are made of optimum materials and methods for manufacturing low-carbon fuels for reduction in greenhouse gas emissions. When their thermal dynamic limits and the technological maturity are considered, it is inferred that no extensive improvement will be achieved by merely improving on the efficiency of the existing fuels. The use of various high-efficiency driving power sources utterly different in mechanism from the conventional ones, such as those for fuel cell-powered automobiles, and the promotion of the use of low-carbon fuels such as methanol and methane for all kinds of driving power sources including those for the said fuel cell-powered automobiles, will become necessary. The use will also be necessary of recyclable materials. The biomass resources, in particular, since they absorb CO2 gas in their growing process by virtue of photosynthesis, may be said to be free of CO2 gas emissions. They have their own problems, however, ...
Oxide catalysis plays a central role in hydrocarbon processing and improvements in catalytic activity or selectivity are of great technological importance because these improvements will translate directly into more efficient utilization of hydrocarbon supplies and lower energy consumption in separation processes. An understanding of the relationships between surface structure and catalytic properties is needed to describe and improve oxide catalysts. Our approach has been to prepare supported oxides that have a specific structure and oxidation state and then employ these structures in reaction studies. Our current research program is focused on studying the fundamental relationships between structure and reactivity for two important reactions that are present in many oxide-catalyzed processes, partial oxidation and carbon-carbon bond formation. Oxide catalysis can be a complex process with both metal cation and oxygen anions participating in the chemical ...
The abatement of CO{sub 2} emissions is a huge technical and economical challenge. Fossil fuels, which represent 88% of the world primary energy consumption, are the main source of the 25 billions of CO{sub 2} released each year in the atmosphere. The mastery of CO{sub 2} emissions cannot come from a single technology but must result from the simultaneous implementation of several means, like the development of carbon-free energies and the mastery of fossil fuel emissions. The opportunities of progress are numerous and compatible with the economic development. This document presents, first, the different greenhouse gases, the CO{sub 2} emissions per country and the main sources of CO{sub 2} emissions (power and heat generation, transports). Then it presents different ways of abatement of CO{sub 2} emissions: clean coal technologies, gas combined cycles, CO{sub 2} sequestration, reduction of fuel consumption in transports, development of ...
The performance of four different organic coating systems applied to carbon and weathering steel coupons has been assessed in this investigation. applied on the surface of carbon steel and weathering steel coupons. The coupons have been evaluated using five different tests, three field tests and two accelerated tests. The field tests were carried out at three atmospheric stations, located at COSIPA in Cubatao-SP, at Alto da Serra in Cubatao-SP and at Paula Souza in Sao Paulo city. The accelerated tests consisted of (a) exposure to alternate cycles of ultraviolet radiation/condensation combined with salt spray cycles (UVCON combined with Salt Spray) and of (b) exposure to alternate cycles of ultraviolet radiation/condensation combined with the Prohesion test. The performance of the coatings was assessed by visual observation and photographs, using a method based on ASTM D-610, ASTM ...
The present study includes thermal stability of some fatty acids as phase change materials (PCMs). The selected fatty acids were stearic, palmitic, myristic and lauric acid with melting temperatures between 40-63{sup o}C and industrial-grade with 90-95% purity. Latent heat storage capacity and phase transition temperature of the PCMs were determined by Differential Scanning Calorimetry (DSC) technique as a function of after repeated thermal cycles such as 40, 410, 700 and 910. The present work also comprises the investigation of corrosion resistance of some construction materials to the fatty acids over a long period. The containment materials tested were stainless steel (SS 304 L), carbon steel (steel C20), aluminium (Al) and copper (Cu). Gravimetric analysis as mass loss (mg/cm{sup 2}), corrosion rate (mg/day) and a microscopic or metallographic investigation were performed for corrosion tests after 910 thermal cycles. ...
ObjectivesNot EnteredDescriptionMethane hydrate in an ice-like substance consisting of molecules of methane gas combined chemically with water. It is stable at high pressures and low temperatures. Since the ocean floor is normally cold, but temperatures increase with depth inside the Earth, such conditions normally prevail for a few hundred meters below the seafloor where the ocean depth is more than a few hundred metres. Methane beneath the ocean floor is formed by the decomposition of organic material. At the edges of the co [continued...
Federal regulators were set to vote on a plan to protect deep water corals and other sensitive fish habitats that will likely include a permanent ban on ...
The classification of petrels (Pterodroma spp.) from Round Island, near Mauritius in the Indian Ocean, has confounded researchers since their...Full Text Available
Deforestation farther inland causes delayed reactions. When roots no longer hold soil in place, it ends up muddying streams, rivers, and coastal waters. ...
A Self-Powered Underwater Robot for Ocean Exploration and Beyond ... first unmanned underwater vehicle (UUV) that is completely powered by renewable energy . ...
The company reports that with the help of outside companies, they completed all major fixes including high-voltage transmission lines to neighborhood ...
A strategy for the management of the disposal of low-level radioactive wastes into coastal zones and ocean waters has developed over the past three decades. While there has been a substantial increase in the number of international and required agreements there has also been a concomitant improvement in our understanding of the ocean and the processes at work within it. This has allowed more rigorous and reliable assessments to be made of the radiological consequences. With the continued development of basic guidelines of radiological protection by the International Commission on Radiological Protection (ICRP) methodologies have been formulated to derive the fundamental scientific requirement - the relationship between disposal or release rate to the ocean and the resultant radiation dose to exposed human populations.
... 2008. Characterizing the relative contributions of large vessels to total ocean noise fields: a case study using the Gerry E. Studds Stellwagen Bank ...
Cheap air conditioning from oceanic temperature differences is a possible new competitor for coal in coastal regions. Coal suppliers planning expansion in growing economies need to be aware of the possibilities and limitations of this new competitor. Ocean thermal energy conversion (OTEC) used to be uneconomic but the National Energy Laboratory of Hawaii (NELH) has developed a very economic method of utilising the temperature difference between warm ocean surface and cold deep ocean to generate energy for air conditioning. The article outlines the process and mentions demonstrations of OTEC technology to produce electricity and air conditioning at a site in Kailua-Kona, Hawaii. Indonesia and India have viable sites for OTEC installations, and NELH is working with Madras State on a project to construct a commercial OTEC plant in India. 2 photos.
... Mineral and Organic Matter in the Coastal and Near-Coastal Ocean. ... Personal Author(s) : Stavn, Robert H. ; Spiering, Bruce A. ; Gould, Richard W ...
Although various legislation and regulations have been adopted to promote the use of alternative-fuel vehicles for curbing urban air pollution problems, there is a lack of systematic comparisons of emission control cost-effectiveness among various alternative-fuel vehicle types. In this paper, life-cycle emission reductions and life-cycle costs were estimated for passenger cars fueled with methanol, ethanol, liquefied petroleum gas, compressed natural gas, and electricity. Vehicle emission estimates included both exhaust and evaporative emissions for air pollutants of hydrocarbon, carbon monoxide, nitrogen oxides, and air-toxic pollutants of benzene, formaldehyde, 1,3-butadiene, and acetaldehyde. Vehicle life-cycle cost estimates accounted for vehicle purchase prices, vehicle life, fuel costs, and vehicle maintenance costs. Emission control cost-effectiveness presented in dollars per ton of emission ...
A new type of zinc electrode is matched with new bifunctional air electrodes to produce a zinc-air battery of a novel design. The zinc electrode is a flow-thru type made from copper foam-metal. The air electrode uses corrosion resistant carbon black as a high area support for a highly dispersed spinel oxide electrocatalyst. The battery design employs flowing electrolyte, 12 M KOH saturated or supersaturated with zincate. Single cells as large as 200 cm{sup 2} (1/5 EV design scale) having a capacity of 20 AH have been tested with C/4--C/16 constant current cycling. More extensive and realistic life cycle testing was done with 2 Ah cells, including the Simplified Federal Urban Driving Schedule (SFUDS) cycle. This testing has confirmed that these cells can provide the necessary transient power response required for urban EV applications. The cells achieved an average of 72 SFUDS repetitions (7.2 hrs) per ...
A new performance model of the externally fired combined cycle (EFCC) is implemented in ASPEN (Advanced System for Process ENgineering), a chemical process simulator. The model accounts for interactions within and between approximately a dozen major process areas. The new model is applied to case studies to evaluate the sensitivity of process performance to the ranges of uncertainty in key model inputs such as heat losses, carbon conversion, and air leakage rates, and to illustrate how alternative designs, including steam injection and flue gas desulfurization (FGD), can affect plant thermal efficiency and net power output. The model results suggest that careful attention to the design of the FGD system is needed, especially with respect to reheat, and that steam injection may offer cost savings associated with reducing the size of the steam turbine with little or no penalty on plant output or plant efficiency. Uncertainties in the slagging ...
Various electrochemical capacitors (ultracapacitors) are being developed for hybrid vehicles as candidate power assist devices for the fast response engine. The primary functions of the ultracapacitor are to level the dynamic power loads on the primary propulsion device and recover available energy from regenerative breaking during off-peak power periods. Ultracapacitors show promise toward being able to accept high regenerative pulses while exhibiting very high cycle life. This paper will present test data from selected US Department of Energy (DOE) supported ultracapacitor projects designed to meet the fast response engine requirements. Devices containing carbon, conducting polymers, and metal oxide electrode materials in combination with aqueous or organic electrolytes are being supported by the DOE. This paper will present and discuss testing data obtained from recent prototype capacitors supplied by Maxwell Energy Products, Inc., SAFT ...
Anaerobic digestion of slurry represents an environmental opportunity for both slurry management and renewable energy production in countries with high animal density. This study evaluated the environmental impacts of 4 biogas production alternatives in which slurry was the only input in the process, without supplementary addition of easily degradable carbon. This was achieved by exposing the slurry to different separation technologies. The biomass mixture input for biogas production included solid fraction from slurry separation as well as raw slurry, proportioned in order to achieve economical methane yield. The separation processes considered in this study were mechanical separation; mechanical separation combined with the addition of flocculants; and mechanical separation combined with a thermal treatment. Four biogas alternatives were compared to a reference slurry management scenario, notably to use the slurry as a fertilizer without prior treatment. The ...
Most prior climate change assessments for U.S. agriculture have focused on major world food crops such as wheat and maize. While useful from a national and global perspective, these results are not particularly relevant to the Northeastern U.S. agriculture economy, which is dominated by dairy milk production, and high-value horticultural crops such as apples (Malus domestica), grapes (vitis vinifera), sweet corn (Zea mays var. rugosa), cabbage (Brassica oleracea var. capitata), and maple syrup (sugar maple, Acer saccharum). We used statistically downscaled climate projections generated by the HadCM3 atmosphere-ocean general circulation model, run with Intergovernmental Panel on Climate Change future emissions scenarios Alfi (higher) and B1 (lower), to evaluate several climate thresholds of direct relevance to agriculture in the region. A longer (frostfree) growing season could create new opportunities for farmers with enough capital to take risks on new crops ...
The production of ozone in a negative corona discharge fed by carbon dioxide with embedded traces of oxygen and water has been studied. The presence of traces of oxygen in both pure and dry CO_2 leads to an increase in nascent ozone concentrations. In contrast, traces of water vapour (0-800 ppm) are shown to rapidly suppress ozone concentrations with the largest decreases being observed at lowest gas pressures in the discharge (300 Torr). The presence of water vapour did not considerably affect the electrical properties of negative dc corona suggesting that a chemical process is responsible for the ozone loss. We have shown that the addition of water up to a concentration of 1500 ppm has only a marginal effect on the processes of ozone formation but the catalytic cycle of ozone destruction involving OH radicals can be the reason for observed decrease in the total ozone concentration with increasing water concentration.
Red mud suspensions are studied as passivating agents for iron in alkaline chloride media. Red mud particles in alkaline media are negatively charged, and can absorb considerable amounts of protons without significant changes in pH. These particles adhere easily to an iron surface forming aggregates of heterogeneous shape, smaller than 10 #mu#mx10 #mu#m. These adhered particles recrystallise on potential cycling, and hinder metal dissolution and magnetite formation. Carbon steel samples passivated in red mud suspensions become resistant to corrosion in alkaline chloride media. Corrosion potential versus time records and impedance spectroscopy measurements allow formulating some hypotheses about the inhibiting mechanism.
Red mud suspensions are studied as passivating agents for iron in alkaline chloride media. Red mud particles in alkaline media are negatively charged, and can absorb considerable amounts of protons without significant changes in pH. These particles adhere easily to an iron surface forming aggregates of heterogeneous shape, smaller than 10 {mu}mx10 {mu}m. These adhered particles recrystallise on potential cycling, and hinder metal dissolution and magnetite formation. Carbon steel samples passivated in red mud suspensions become resistant to corrosion in alkaline chloride media. Corrosion potential versus time records and impedance spectroscopy measurements allow formulating some hypotheses about the inhibiting mechanism.
The peanut plant (Arachis hypogaea L.), unlike other known legumes, can sustain nitrogen fixation when prolonged periods of darkness or detopping curtail the supply of photosynthate to the nodule. This ability to withstand photosynthate stress is attributed to the presence of lipid bodies in infected nodule cells. In both dark-treated and detopped plants, the lipid bodies show a gradual decrease in numbers, suggesting their utilization as a source of energy and carbon for nitrogen fixation. Lipolytic activity can be localized in the lipid bodies, and the existence of #beta#-oxidation pathway and glyoxylate cycle is shown by the release of "1"4CO_2 from "1"4C lineoleoyl coenzyme A by the nodule homogenate.
Remote sensing is the most practical method available to managers of fire-prone forests for quantifying and mapping fire impacts. Differenced Normalised Burn Ratio (?NBR) is among the most widely used spectral indices for the mapping of burn severity but is difficult to interpret in terms of fire-related changes in key biophysical attributes and processes. We propose to quantify burn severity as a change in the leaf area index (?LAI) of a stand. LAI is a key biophysical attribute of forests, and is central to understanding their water and carboncycles. Previous studies have suggested that changes in canopy LAI may be a major contributor to ?NBR and to the composite burn index (CBI) that is frequently used in combination with the NBR to assess burn severity on the ground. We applied remote...
A methane catalytic decomposition reactor-direct carbon fuel cell-internal reforming solid oxide fuel cell (MCDR-DCFC-IRSOFC) energy system is highly efficient for converting the chemical energy of methane into electrical energy. A gas turbine cycle is also used to output more power from the thermal energy generated in the IRSOFC. In part I of this work, models of the fuel cells and the system are proposed and validated. In this part, exergy conservation analysis is carried out based on the developed electrochemical and thermodynamic models. The ratio of the exergy destruction of each unit is examined. The results show that the electrical exergy efficiency of 68.24% is achieved with the system. The possibility of further recovery of the waste heat is discussed and the combined power-heat exergy efficiency is over 80%. (author)
A methane catalytic decomposition reactor-direct carbon fuel cell-internal reforming solid oxide fuel cell (MCDR-DCFC-IRSOFC) energy system is highly efficient for converting the chemical energy of methane into electrical energy. A gas turbine cycle is also used to output more power from the thermal energy generated in the IRSOFC. In part I of this work, models of the fuel cells and the system are proposed and validated. In this part, exergy conservation analysis is carried out based on the developed electrochemical and thermodynamic models. The ratio of the exergy destruction of each unit is examined. The results show that the electrical exergy efficiency of 68.24% is achieved with the system. The possibility of further recovery of the waste heat is discussed and the combined power-heat e...
The erosion of rocks rich in organic matter typically leads to the complete mineralization of the organic material. However, in some cases, it is re-deposited to become a part of sediments once more. This process should be considered to be a part of global carboncycle, possibly much more significant than assumed to-date. The research presented here aims to characterize re-worked organic matter occurring in post-glacial sediments of southern part of Poland, in the Oder river valley (the Racib?rz town region, Miocene, Pleistocene and Holocene age). Organic substances extracted from the sediments originated from organic matter that had resided in rocks eroded by glaciers. Sediments were sampled in two boreholes which sediments were correlated. Sediments were extracted and extracts analyzed w...
The comprehensive theoretical and experimental study of the adsorption of water and methanol molecules on active sites (carboxyl and phenol hydroxyl groups) on the graphitized thermal carbon black is performed. It is shown that microclusters formed upon the adsorption of these molecules on such sites are characterized by the cyclic structure comprising 4?5 molecules similar to that whose existence was revealed previously in liquid water and on the surface of silver iodide. The analysis of the studied adsorption clusters demonstrated that the formation of such cycles is governed primarily by the hydrogen bonding; however, a definite role is played also by energy effects associated with the changes in the state of molecular motion during adsorption. It is shown that the generalized Langmuir ...
Smooth and notched specimens of the bearing steel 100Cr6 (SAE 52100) in a bainitic condition were used to determine the S-N curves under tensile, torsional and combined in- and out-of-phase loading. In the area of high-cycle fatigue, crack initiation was most likely caused by inclusions like Titanium Carbon nitrides or Aluminium Oxides. A micro mechanical model for the crack initiation by inclusions was developed. Another model was developed to describe the influence of these inclusions on the lifetime. A weakest-link model, using the statistical distribution of inclusions and surface flaws, was used to describe the endurance limit. (orig.)
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)
With an objective to use reproducible vegetable oil as a substitute fuel, studies were performed to use emulsified rapeseed oil at an optimal mixing ratio with water in a direct injection diesel engine. The experiment used a water cooled, lateral installation, single-cylinder, direct injection, four-cycle diesel engine, and the tested fuel used an emulsified rapeseed oil fuel with rapeseed oil added with water at a rate of 20% by weight. As a result of the experiment using the emulsified rapeseed oil, it was found that reducing the injection opening diameter smaller than the standard opening diameter improves the engine performance and simultaneously reduces concentrations of HC, CO and exhaust smoke. The optimal opening diameter was about 0.22 mm. Increasing the valve opening pressure reduced the NOx concentration, but increased the HC concentration. Using the emulsified rapeseed oil fuel accumulated more carbon below the head, but much ...
An automated Time Resolved Aerosol Collector (TRAC) has been developed for sequential sampling of field-collected aerosols for laboratory-based Computer Controlled Scanning Electron Microscopy/Energy Dispersed X-ray (CCSEM/EDX) single particle analysis. The collector is optimized for use of grid-supported 20 nm carbon films as deposition substrates. The carbon films have low enough X-ray background to permit EDX analysis down to 0.1-0.2 ?m particles, including detection of low-Z elements: C, N, & O. The TRAC provides unattended sampling onto a set of 151 individual grids, at sequential time intervals as short as 1 min. After collection, the samples are sealed and refrigerated pending analysis. The utility of the TRAC-CCSEM/EDX approach is exemplified using the aerosol samples collected during the Texas 2000 Air Quality Studies (Aug. 15 ? Sept. 15, 2000). We are able to quantitatively follow the time evolution in the relative contribution of ...
Products of a power plant flue gas desulfurization scrubber are discharged into a pond as sludge consisting of calcite (initial delta13C 3.2-3.8 per thousand), gypsum (initial delta34S 7.6-8.6 per thousand), and aqueous solution. Reducing conditions exist below a boundary that appears to move vertically as a function of changes in pond water level. Under reducing conditions, bacteria partially reduce aqueous sulfate to low-delta34S sulfide, consuming organic carbon and generating low-delta13C bicarbonate. Under oxidizing conditions, sulfide is converted to sulfate, leading to calcite dissolution, gypsum precipitation, and isotopic re-equilibration of remaining calcite with dissolved bicarbonate near the pond surface. The gypsum has delta34S near 6 per thousand, and calcite has delta13C as low as -1.7 per thousand; the changes from initial values correspond to predictions based on isotopic balance and reaction stoichiometry. The pond largely contains the products of ...
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 off which may pass a methanation device.
A thermal analyzer-differential scanning calorimeter-mass spectrometer (TG-DSC-MS) was used to study oxygen carriers (OC) for their potential use for the application of chemical looping combustion (CLC) to solid fuels. Reaction rates, changes in reaction rates with repeated oxidation-reductions, exothermic heats during oxidation, and the effect of changing reduction gas compositions were studied. Oxidation rates were greater than reduction rates and reaction rates were reproducible through multiple oxidation-reduction cycles except where agglomeration occurred with powders. Iron oxide (Fe{sub 2}O{sub 3} powder) and iron-based catalysts were found suitable for CLC of solid fuels having rapid reduction rates which increased with higher reducing gas concentrations. Fe{sub 2}O{sub 3} powder was used to oxidize a high carbon coal char in an inert gas removing 88% of the carbon from the char. Other properties such as cost and ...
The processes controlling total carbon (C) storage and release from the terrestrial biosphere are still poorly quantified. We conclude from analysis of paleodata and climatebiome model output that terrestrial C exchanges since the last glacial maximum (LGM) were dominated by slow processes of C sequestration in soils, possibly modified by C starvation and reduced water use efficiency of trees during the LGM. In contrast, future C cycling will be dominated by human activities, not only from increasing C release with burning of fossil fuels, and but also from indirect effects which increase C storage in the terrestrial biosphere and decrease C storage in the biosphere. Comparison of the positive and negative C flux processes involved suggests that if the C sequestration processes are important, they likely will be so during the next few decades, gradually being counteracted by the C release processes. (Copyright (c) l993 Kluwer Academic ...
The impacts of the expected climate change on Finnish lake ecosystems were studied with the biota of the mesohumic Lake Paeaejaervi, southern Finland. Experimental conditions, from small-scale experiments on single species level to a large-scale ecosystem manipulation, were established to simulate directly the future climate and/or loading of nutrients and dissolved organic matter (DOM) from the drainage area. The experimental studies were accomplished by modelling the carbon flow in the pelagic food web as well as the growth of littoral macrophytes. The main hypothese tested were as follows: As a consequence of the climate change (rising temperature and increasing precipitation) the loading of nutrients and dissolved organic matter (DOM) from the drainage area to the lake will increase. In the pelagic zone this will be first reflected i higher productivity of primary producers and bacteria, but will later affect the entire food chain. Increase in atmospheric ...
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 carrier investigating ...
This study is part of a greater project from IPT (Sao Paulo's Institute of Technology), which foresaw an energetic use for elephant-grass (Pennisetum purpureum). Biomass gasification is an sustainable option for energy supply, which presents low pollutants emission rate and allows - through the global cycle of growing and consumption of feedstock (vegetables), a balance between consumption and production of carbonic gas, preventing an increase of the carbonic gas levels in the atmosphere. A gasifier was built with internal diameter of 400 mm and total height of 4600 mm . The equipment was tested for gasification of elephant-grass (Pennisetum purpureum) at a 100 kg/h rate. The equipment was tested and some constructive faults were detected. In the countryside, this biomass is commonly used for cattle feeding It was evaluated an adequate diesel-electric-generator. to work at hybrid regime, using 70% biomass gas and ...
Metabolic engineering of photosynthetic organisms is required for utilization of light energy and for reducing carbon emissions.Control of transcriptional regulators is a powerful approach for changing cellular dynamics, because a set of genes is concomitantly regulated. Here, we show that overexpression of a group 2 ? factor, SigE, enhances the expressions of sugar catabolic genes in the unicellular cyanobacterium, Synechocystis sp. PCC 6803. Transcriptome analysis revealed that genes for the oxidative pentose phosphate pathway and glycogen catabolism are induced by overproduction of SigE. Immunoblotting showed that protein levels of sugar catabolic enzymes, such as glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, glycogen phosphorylase, and isoamylase, are increased. Glycogen levels are reduced in the SigE-overexpressing strain grown under light. Metabolome analysis revealed that metabolite levels of the TCA cycle and ...
LiFePO{sub 4} cathode materials with distinct particle sizes were prepared by a planetary ball-milling method. The effects of particle size on the morphology, thermal stability and electrochemical performance of LiFePO{sub 4} cathode materials were investigated. The ball-milling method decreased particle size, thereby reducing the length of diffusion and improving the reversibility of the lithium ion intercalation/deintercalation. It is worth noting that the small particle sample prepared using malonic acid as a carbon source achieved a high capacity of 161 mAh g{sup -1} at a 0.1 C rate and had a very flat capacity curve during the early 50 cycles. However, the big particle samples ({proportional_to}400 nm) decayed more dramatically in capacity than the small particle size samples ({proportional_to}200 nm) at high current densities. The improvement in electrode performance was mainly due to the fine particles, the small size distribution, and ...
A single particle micro-electrode technique has been applied, to study adsorption and mass transport phenomena of a TEABF{sub 4}/acetonitrile solution in a nano-porous carbon. The nano-porous carbon, which is obtained from SiC, has a very small and narrow pore size distribution around 8 Angstrom. Therefore, it is a good model material for studying adsorption processes in micropores. The results from cyclic voltammetry showed that a higher specific capacitance was obtained in the positive potential interval (vs Ag/AgNO{sub 3}). Upon activation cycling the mass transport inside the nano-porous particle becomes drastically hindered, probably by TEA{sup +} that is adsorbed and is partially blocking the micropores. Effective diffusion coefficients, Deff, were determined from potential step experiments. At positive potentials Deff was 1.5 {+-} 0.5 x 10{sup -8} cm{sup 2}s{sup -1}, whereas at more negative potentials Deff decreased ...
The carbon dioxide concentration has been measured in air samples collected approximately once per week at 22 globally distributed sites during 1981-1984. All samples were analyzed on the same non-dispersive infrared analyzer apparatus. The measured concentrations are directly traceable to the WMO primary CO/sub 2/ standards. Samples which do not contain well-mixed, regionally representative air or which have been contaminated during or subsequent to sampling, have been identified. The selected data have been analyzed using an objective curve fitting method which enables improved estimation of uncertainties associated with derived parameters. The latitudinal distribution of annual mean CO/sub 2/ concentration at the network sites shows significant interannual variability possibly related to the 1982-1983 El NinoSouthern Oscillation event. No evidence was found for significant interannnual variations or trend in the phase or amplitude of the seasonal ...
Polyacrylonitrile (PAN)-based polymer electrolytes have obtained considerable attention due to their fascinating characteristics such as appreciable ionic conductivity at ambient temperatures and mechanical stability. This study is based on the system PAN-ethylene carbonate (EC)-propylene carbonate (PC)-lithium trifluoromethanesulfonate (LiCF3SO3). The composition 15 mol% PAN-42 mol% EC-36 mol% PC-7 mol% LiCF3SO3 has shown a maximum room temperature conductivity of 1.2 x 10(-3) stop S cm(-1) stop. Also, it was possible to make a thin, transparent film out of that composition. Cells of the form, Li/PAN-EC-PC-LiCF3SO3/polypyrrole (PPy)-alkylsulfonate (AS) were investigated using cyclic voltammetry and continuous charge-discharge tests. When cycled at low scan rates, a higher capacity could be obtained and well-defined peaks were present. The appearance of peaks elucidates the fact that redox reactions occur completely. This ...
Pyrrolo[2,1-c][1,4]benzodiazepine (PBD) chemicals are antitumor antibiotics inhibiting nucleic acid synthesis. An indole carboxylate-PBD hybrid with six-carbon spacer structure (IN6CPBD) has been previously demonstrated to induce melanoma cell apoptosis and reduce metastasis in mouse lungs. This study aimed at investigating the efficacy of the other hybrid compound with four-carbon spacer (IN4CPBD) and elucidating its anti-metastatic mechanism. Human melanoma A375 cells with IN4CPBD treatment underwent cytotoxicity and apoptosis-associated assays. Transwell migration assay, Western blotting, and ELISA were used for mechanistic study. IN4CPBD exhibited potent melanoma cytotoxicity through interrupting G1/S cell cycle progression, increasing DNA fragmentation and hypodipoidic DNA contents, a...
Kelvin-Helmholtz instability of short gravity waves is examined in order to explain the recent findings of the decrease in momentum transfer from hurricane winds to sea waves. A three-fluid configuration of a foam layer between the atmosphere and the ocean is suggested to provide signifficant stabilization of the system and shifting the marginal critical wavelength to the shortwave part of the spectrum. It is conjectured that such stabilization leads to the observed drag reduction. The high contrasts in three fluid densities provide a universal mechanism for stabilizing surface perturbations.
... Rachel has also studied Geological Oceanography at the School of Ocean and Earth Sciences, University of Wales, Bangor, including a year spent at the Institute of Oceanographic Sciences Deacon Laboratory, Surrey, as a student researcher for the British Mid-Ocean Ridge Initiative (BRIDGE). Rachel has authored the following 1 Working Papers: 2002 ecm-2002-05 Towards Integrated Catchment/Coastal Management: Science, Policy ...
Separate abstracts were prepared for 20 papers in this conference report and includes all papers in the ''engineering'' section (program E). Ocean thermal energy conversion (OTEC), moorings, cables, corrosion protection, corrosion testing, coatings, offshore platforms, pipelines, OTEC models and pilot plants, and energy transfer are topics discussed.
The aim of this paper is to provide a general view of wave energy resource assessment. First, a review of the origin of waves and the transformation they undergo as they propagate towards the coast through waters of decreasing depth is presented. Following this, the wave and wave-energy parameters and the statistics required for resource characterization are described. The various types of wave data and their usefulness for the present purposes are summarised. A common methodology for assessment of the wave energy resource is developed. Finally, a general description of the global open ocean resource is presented.
...ENSO Applications Center (PEAC) Institutional Affiliation: PEAC's core members are The National Oceanic and Atmospheric Administration - Office of Global Programs (NOAA/OGP) The NOAA National Weather Service - Pacific Region (NWS-PR), The University of Hawaii - School of Ocean and Earth Science and Technology UH/SOEST, The University of Guam - Water and Energy Research Institute (UOG/WERI), and a regional association of the USAPI Governments, the Pacific Basin ...
Reinterpretation of the South Florida basin reveals that it was a keep-up carbonate shelf during the Lower Cretaceous. Until the Cenomanian, it was connected to the Bahamas and the Cay Sal Bank north of Cuba. The Cenomanian sea level rise was at least partially responsible for the formation of the Florida Straits, isolating the platform. The combination of an abrupt worldwide rise in sea level and subsidence caused the South Florida platform to founder, ending shallow-water and evaporitic sedimentation over the majority of the shelf. The Cay Sal and Bahamian platforms remained as active shallow shelves separated by the Old Bahamas Channel. The Lower Cretaceous sediments are characterized by shallow shelf limestones, dolomites, and evaporites (mostly anhydrite). The evaporite-rich sections, originally thought to represent basinal facies, are reinterpreted as supratidal to shallow subtidal evaporites, based on examination of core and cuttings. Influx of normal marine ...
An outcrop-based study combining detailed lithofacies analysis with high-resolution sequence stratigraphy in the Paradox Basin, southwestern United States. has shown that complex lateral and vertical facies variations occur in relatively consistent and predictable patterns. Large-scale facies shifts of several kilometers occur across major sequence boundaries whereas small-scale lateral and vertical variations develop from stacking of individual cycles. Understanding of vertical stacking patterns and lateral distribution of facies in outcrop can be directly applied to both three-dimensional distribution of reservoir facies in the subsurface as well as the evaluation of heterogeneity within individual reservoirs. The Desert Creek and Ismay intervals of the Paradox Formation (Pennsylvanian) exposed along the San Juan River in southeastern Utah are characterized by high-frequency cyclic repetition of carbonate and siliciclastic facies controlled ...
Silicon is an attractive alloy-type anode material because of its highest known capacity (4200 mAh/g). However, lithium insertion into and extraction from silicon are accompanied by a huge volume change, up to 300%, which induces a strong strain on silicon and causes pulverization and rapid capacity fading due to the loss of the electrical contact between part of silicon and current collector. Si nanostructures such as nanowires, which are chemically and electrically bonded to the current collector, can overcome the pulverization problem, however, the heavy metal current collectors in these systems are larger in weight than Si active material. Herein we report a novel anode structure free of heavy metal current collectors by integrating a flexible, conductive carbon nanotube (CNT) network into a Si anode. The composite film is free-standing and has a structure similar to the steel bar reinforced concrete, where the infiltrated CNT network functions as both ...
The summertime tropical cyclogenesis rate per unit area in the eastern Pacific ocean is arguably higher than in any other location in the world. Many if not most of these cyclones form from African easterly waves which cross Central America into the Pacific. Of order 25% of these waves intensify into cyclones. A significant fraction of east Pacific tropical cyclones undergoes landfall on the Mexican coast. Those which do not, generally dissipate over cold ocean waters north of the east Pacific intertropical convergence zone, often not far from land. The layer of warm ocean water which supports the development of east Pacific cyclones is unusually shallow and is structured by anticyclonic vortices which form by various processes and propagate slowly to the west. These vortices locally deepen the oceanic mixed layer and support stronger convection than their surroundings, possibly promoting ...
The Formerly Utilized Sites Remedial Action Program (FUSRAP) of the Department of Energy is designed to identify and evaluate the radiological conditions at sites formerly used by the Corps of Engineers Manhattan Engineer District and the US Atomic Energy Commission. Where required, remedial action will be instituted to remove potential restrictions on the use of the sites due to residual low-level radioactive contamination. A total of 31 sites that may require remedial action has been identified. The purpose of the Ocean FUSRAP Program, which began in March 1981, is to assess the technical, environmental, and institutional feasibility of disposing, in the ocean and on the ocean floor, of FUSRAP soil and rubble which contains traces of natural radioactive materials. The initial focus has been on the Middlesex, New Jersey, Sampling Plant site and surrounding properties, which contain on the order of 100,000 metric tons of ...
The Formerly Utilized Sites Remedial Action Program (FUSRAP) of the Department of Energy is designed to identify and evaluate the radiological conditions at sites formerly used by the Corps of Engineers Manhattan Engineer District and the US Atomic Energy Commission. Where required, remedial action will be instituted to remove potential restrictions on the use of the sites due to residual low-level radioactive contamination. A total of 31 sites that may require remedial action has been identified. The purpose of the Ocean FUSRAP Program, which began in March 1981, is to assess the technical, environmental, and institutional feasibility of disposing, in the ocean and on the ocean floor, of FUSRAP soil and rubble which contains traces of natural radioactive materials. The initial focus has been on the Middlesex, New Jersey, Sampling Plant site and surrounding properties, which contain on the order of 100,000 metric tons of ...
This paper reports on the first U.S. tanker converted to a floating production, storage, and offloading (FPSO) unit which takes up station in Gombe-Beta field off Gabon by Dec. 1. FPSO Ocean Producer will work under a 3 year, day rate contract let late in 1990 by Amoco-Gabon Bombe Marin co., a unit of Amoco Production Co. (OGJ, Dec. 24, 1990, p. 27). Gombe-Beta field is in the Atlantic Ocean about 70 miles south of Port Gentil, Gabon. Ocean Producer will be moored in 50 ft of water 3.7 miles off Gabon, with Bombe-Beta's unmanned production platform about 820 ft astern. The vessel will be held in position by a disconnectable, asymmetric, six point, spread mooring system, It is owned and operated by Oceaneering International Services Ltd. (OISL). Affiliate Oceaneering Production Systems (OPS) converted the 78,061 dwt oil tanker MT Baltimore Sea at a capital cost of $25 ...
The basic biology of the menstrual cycle is a complex, coordinated sequence of events involving the hypothalamus, anterior pituitary, ovary, and endometrium. The menstrual cycle with all its...Full Text Available
Political leaders in numerous nations argue for an upper limit of the global average surface temperature of 2 K above the pre-industrial level, in order to attempt to avoid the most serious impacts of climate change. This paper analyzes what this limit implies in terms of radiative forcing, emissions pathways and abatement costs, for a range of assumptions on rate of ocean heat uptake and climate sensitivity. The primary aim is to analyze the importance of ocean heat uptake for radiative forcing pathways that temporarily overshoot the long-run stabilization forcing, yet keep the temperature increase at or below the 2 K limit. In order to generate such pathways, an integrated climate-economy model, MiMiC, is used, in which the emissions pathways generated represent the least-cost solution o...
This book, an updated version of the 1985 edition, contains thirteen chapters, beginning with a preface which provides the objective of the book. The primary objective is to offer a comprehensive survey of the biological, hydrological, mathematical, and biochemical aspects of stream, lake, estuary, and ocean pollution analysis. The book also contains ten appendices of useful tables and nomographs of pertinent data. This book provides a very good summary and review of stream, lake, estuary, and ocean pollution. This book is recommended for environmental engineering students, environmental consulting engineers, and regulatory personnel. It provides an excellent summary of the field of stream and lake analysis and modeling. Every chapter includes a significant number of questions and pertinent references.
Spratly Islands, located in the southern part of the South China Sea (SCS), consist of more than 100 small islands, coral reefs and banks. Remote sensing is the only way to obtain a synoptic view of all of the islands in such a large area. It has been demonstrated that satellite synthetic aperture radar (SAR) imagery is a very powerful tool for monitoring meso-scale and small-scale ocean processes in a large area. In this study, satellite SAR images were used to study the ocean environment in the area of Spratly Islands. The aim was to understand the capability of satellite remote sensing to monitor ocean processes and provide information for future field studies. Two sets of high-resolution European Remote Sensing satellite (ERS)-2 SAR images over the entire Spratly Islands area were coll...
Various SST indices in the Indo-Pacific region have been proposed in the literature in light of a long-range seasonal forecasting of the Indian Summer Monsoon (ISM). However, the dynamics associated with these different indices have never been compared in detail. To this end, the present work re-examines the variabilities of ISM rainfall, onset and withdrawal dates at interannual timescales and explores their relationships with El Ni?o-Southern Oscillation (ENSO) and various modes of coupled variability in the Indian Ocean. Based on recent findings in the literature, five SST indices are considered here: Ni?o3.4 SST index in December?January both preceding [Nino(?1)] and following the ISM [Nino(0)], South East Indian Ocean (SEIO) SST in February?March, the Indian Ocean Basin (IOB) mode in ...
Man's wastes are polluting the oceans from various sources and delivered by various routes. The result has been the loss of habitat and the irreversible altering of marine ecosystems. Development in the coastal zones and offshore activities that disrupt biologically sensitive areas have led to international negotiations to regulate these impacts and develop a law of the sea. Basic to international cooperation, however, is the need to develop answers to questions about the ecological consequences of development programs and the carrying capacity of the oceans. Current information does not demonstrate long-term global impacts, making it difficult to detect and predict incremental changes and causal relationships. Society needs to determine how much environmental damage it will accept and then to develop appropriate technology, such as biomonitoring. Society also needs to reexamine its positions on technology-based regulatory controls to ...
Understanding the processes responsible for coastal change is important for managing our coastal resources, both natural and economic. The current scientific understanding of coastal sediment transport and geology suggests that examining coastal processes at regional scales can lead to significant insight into how the coastal zone evolves. To better identify the significant processes affecting our coastlines and how those processes create coastal change we developed a Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System, which is comprised of the Model Coupling Toolkit to exchange data fields between the ocean model ROMS, the atmosphere model WRF, the wave model SWAN, and the sediment capabilities of the Community Sediment Transport Model. This formulation builds upon ...
The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg U/m{sup 3} in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific nonwoven fabric was used as the adsorbent packed in an adsorption cage 16 m{sup 2} in cross-sectional area and 16 cm in height. We submerged three adsorption cages in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The three adsorption cages consisted of stacks of 52 000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the nonwoven fabric was >1 kg in terms of yellow cake during a total submersion time of 240 days in the ocean.
The total amount of uranium dissolved in seawater at a uniform concentration of 3 mg U/m3 in the world's oceans is 4.5 billion tons. An adsorption method using polymeric adsorbents capable of specifically recovering uranium from seawater is reported to be economically feasible. A uranium-specific nonwoven fabric was used as the adsorbent packed in an adsorption cage 16 m2 in cross-sectional area and 16 cm in height. We submerged three adsorption cages in the Pacific Ocean at a depth of 20 m at 7 km offshore of Japan. The three adsorption cages consisted of stacks of 52 000 sheets of the uranium-specific non-woven fabric with a total mass of 350 kg. The total amount of uranium recovered by the nonwoven fabric was >1 kg in terms of yellow cake during a total submersion time of 240 days in the ocean.
Beach rocks are observed frequently on the tropical and subtropical sandy beaches where they express thin beds dipping seaward at less than 15 degrees. They consist of beach sediments including fossil shells, fragments of corals, diatoms and other biocarbonates, and are well cemented within the inter-tidal zone with calcium carbonate originated in sea water. Therefore, they are not only good indicators which show the past sea level, but also provide good sample material for radiocarbon dating. The locations of beach rocks give us an optimum condition studying a carboncycle between land and marine environment by analyzing their isotope fractionations. In order to estimate the origin of calcium carbonate which worked as an adhesive when beach rocks were formed and to estimate the formative ages of beach rocks, a total of 330 fossil corals, fossil shells and calcarenite or calcirdite samples were ...
This report documents the technical development for a patent disclosure of a double-clad process for the continuous casting of thin-strip carbon steel. The fundamental idea of the disclosure is to form a product strip by depositing molten steel between two, cooled, clad strips of the same material. The claimed benefits include: (a) the conservation of energy in steel making through the elimination of soaking pits and reheat cycles, and (b) an improved surface on both sides of the as-cast product such that it will be suitable for direct feed to a cold-reduction mill. However, the process as conceived is not necessarily limited to the casting of carbon steel, but may be also applied to other metals and alloys. The work is described under three headings as follows. Preliminary Considerations and Scoping Analysis presents the basic idea of the double-clad, thin-strip casting process; the energy conservation potential; scoping ...
Anthropogenic nitrogen (N) deposition affects many natural processes, including forest litter decomposition. Saprotrophic fungi are the only organisms capable of completely decomposing lignocellulosic (woody) litter in temperate ecosystems, and therefore the responses of fungi to N deposition are critical in understanding the effects of global change on the forest carboncycle. Plant litter decomposition under elevated N has been intensively studied, with varying results. The complexity of forest floor biota and variability in litter quality have obscured N-elevation effects on decomposers. Field experiments often utilize standardized substrates and N-levels, but few studies have controlled the decay organisms. Decomposition of beech (Fagus sylvatica) blocks inoculated with two cord-forming basidiomycete fungi, Hypholoma fasciculare and Phanerochaete velutina, was compared experimentally under realistic levels of simulated N deposition at ...
The electrochemical intercalation of non-solvated lithium in different graphited materials has been performed in LiClO{sub 4}-ethylene carbonate (EC) medium. The irreversible capacity observed during the first output is mainly due to the formation of a passivation layer made of electrolyte reduction products. These products have been characterized for different electrode reduction potentials using transmission electron microscopy (image, diffraction) and electron energy loss spectroscopy (EELS). EC reduction on the electrode surface in presence of LiClO{sub 4} leads to the formation of Li{sub 2}CO{sub 3} for potentials close to 0.8 V vs Li{sup +}/Li. For lower potentials, the electrolyte reduction reaction goes on with the formation of different lithium alkyl-carbonates. In LiClO{sub 4}-propylene carbonate (PC) medium, the interface phenomena are different. The reduction of a graphite electrode is characterized by the ...
A new 500 kV one cycle electric circuit breaker with a mininum interrupting time of 12.5 m sec is described. The breaker, associated with a 1/4 cycle relay, insures a one cycle interruption. 5 refs.
of satellite, aircraft and ground-based observations. In ..... swarm traps by Utah Department of Food and Agriculture (DAF) personnel. Preliminary Results ..... the 150th anniversary of the book's publication and the 200th anniversary of Darwin's birth. ...... cold war submarine missions to find that Arctic Ocean ...
BackgroundDinoflagellates are unicellular, often photosynthetic protists that play a major role in the dynamics of the Earth's oceans and climate. Sequencing of dinoflagellate nuclear...Full Text Available
Meso- and submesoscales (fronts, eddies, filaments) in surface ocean flow have a crucial influence on marine ecosystems. Their dynamics partly control the foraging behavior and the displacement of marine...Full Text Available
The ratio of particle velocity to translation speed exceeds 1 for 98% of .... The westward movement of the meandering jet and eddy system transports nutrient- rich ...... J. Hydrometeor., 4, 1044-1066. Gedney, N., P. M. Cox, H. Douville, ...
BackgroundIt has been reported that the El Niño–Southern Oscillation (ENSO) influences the interannual variation of endemic cholera in Bangladesh. There is increased...Full Text Available
BackgroundFood supply from the ocean is constrained by the shortage of domesticated and selected fish. Development of genomic models of economically important fishes should assist...Full Text Available
Separate abstracts were prepared for 60 papers in this volume of conference proceedings. None other papers in the proceedings were previously abstracted for EDB. Also included in the proceedings but not indexed separately are six workshop summaries and a session introduction. (LEW)
Computer programs have been developed to define the temperature increase which would be needed to bring deep-ocean water into density equilibrium with surface water for locations where data are available. A series of continuous-flow studies on phytoplankton blooms resulting from mixtures of 80 percent deep and 20 percent surface water in 2000-liter concrete culturing vessels (''reactors'') has been completed. A quantitative determination of nutrient utilization and flow through a combined primary and secondary trophic level system has been completed. This study utilized the clam Tapes semidecussata, fed from phytoplankton grown in 80 percent deep and 20 percent surface water. An analysis of the fate of the deep water discharged from a floating OTEC plant indicates that horizontal containment of the resulting deep water: surface water mixture is necessary if conditions optimal for open-sea mariculture are to obtain. The design of ...
In the IEEE Marine Technology Society OCEANS 2009 Conference, Biloxi. October 26-29, 2009. Biloxi, MS. Al-Hamdan, M.; Estes, M.; Quattrochi, D.; Thom, R.; ...
provides global ocean-surface wind fields with more structures than numerical weather prediction (Geophys. Res. Lett., Vol 25, No. 6, 761-764). The NSCAT data sets was produced...
Records of past climates contained in ice cores, ocean sediments, and other archives show that large, abrupt, widespread climate changes have occurred repeatedly in the past. These changes were especially...Full Text Available
Foreward: Preface; Introduction; The natural science of global climate change; Land and water use; Coastal zones and oceans; Energy and industry; Energy and social systems; Technological change; and Sponsoring organizations, International Advisory Board, and project participants.
It is now widely accepted that novel infectious disease can be a leading cause of serious population decline and even outright extinction in some invertebrate and vertebrate groups (e.g., amphibians)....Full Text Available
Harmful algal blooms, caused by rapid growth and accumulation of certain microalgae in the ocean, pose considerable impacts on marine environments, aquatic industries and even public health. Here, we...Full Text Available
Ocean thermal energy conversion (OTEC) plants discharge large volumes of cold water into the upper ocean. A three-dimensional, limited-area model was developed to investigate the regional influence of the far-field effluent plume created by the negatively buoyant discharge. The model was applied to discharges from a 40-MW/sub e/ OTEC plant into coastal waters characterized by various ambient ocean conditions. A typical ambient temperature structure and nutrient distribution, as well as the behavior of the effluent plume itself, were strongly modified by the discharge-induced circulation. Although temperature perturbations in the plume were small, upward entrainment of nutrients from below the thermocline was significant. The regional influence of discharges from an 80-MW/sub e/ OTEC plant, the interactions between the discharges from two adjacent 40-MW/sub e/ OTEC plants, and the effects of coastal boundary and bottom ...
Adenosine triphosphate (ATP) is an indicator of living biomass in marine particulates. This report details the method used by Lawrence Berkeley Laboratory to analyze particulate ATP in samples taken from oligotrophic, tropical ocean waters. It represents a synthesis of previously published methods.
BackgroundOceans are iron-deficient and nutrient-poor environments. These conditions impart limitations on our understanding of and our ability to identify microorganisms from the...Full Text Available
Picocyanobacteria of the genus Synechococcus are important contributors to marine primary production and are ubiquitous in the world's oceans. This genus is genetically diverse, and...Full Text Available
The present paper is concerned with the prediction method for the motions and tensions of mooring lines on slack-moored floating oceanic architectural building in coastal zone. The motions and the tensions of mooring lines were estimated by the time domain numerical simulation in the present method. The present method includes the nonlinearity of mooring system, slow varying wave drift force. The authors performed a time domain numerical simulation for motions and the tensions of mooring lines on floating barge in two component waves. Also, the results obtained by numerical simulation were compared with the experimental results. The validity of the present method was confirmed.
It is often advantageous to generate power with combinations of wind and ocean waves. In fact ocean waves, their generation, propagation, dissipation are directly related to wind velocity and its duration oven the sea. In this paper an attempt has been made to demonstrate statistically to present some advantages with combined wind and ocean wave power generation. Even though many conceptual techniques and methods are possible to harness combined power generation, it is important to test feasibility of combined output as well as individual outputs mathematically. One of the major advantages of combined wind and wave power generation is to improve probability of continuous power supply (it minimises the interruptions and compensates power fluctuations with one another). Some of the major wave characteristics like wave Height (H), Time period (T), Wave length (L) significantly influence wave power generation. Interestingly, ...
This paper reports on steam injection cycle which is similar to supplementary fired combined cycle, but for the utilized steam medium produced by HRSG, its temperature is higher and pressure is lower than in the combined cycle. In comparison with the thermodynamic advantage of the two cycles, a clear understanding of physical concept can be gotten simply by energy balance. The difference of total power output between them is subtraction of enthalpy difference of exhaust steam and feed water of HRSG in steam injection cycle from the rejected heat by water coolant of condenser in combined cycle, when using the identical gas turbine and the same amount of total fuel consumption. In general case, formulas and data are given to indicate this comparison by the ratio of steam mass flow supplied by HRSG of the two cycles. The analysis of Cheng ...
Electricity generation from natural gas in gas turbine units can be made substantially more efficient by preliminary methane conversion to a synthesis gas containing hydrogen and carbon monoxide and/or by the use of some of the synthesis gas produced in industry. An alternative improvement involves the introduction of solid oxide fuel cells (SOFCs) and the use of the synthesis gas in them. In this study, a modified scheme of gas turbine cycle that includes an SOFC, a membrane reactor (instead of a traditional combustion chamber), and a catalytic reactor to perform methane conversion to produce hydrogen (synthesis gas) is proposed. Variations of the energy and exergy efficiencies of the integrated system with operating conditions are provided, showing, for example, that SOFC efficiency is enhanced if the fuel cell active area is augmented. The SOFC stack efficiency can be maximized by reducing the steam generation while increasing the stack ...
The untreated, heat- and alkali-treated Lentinus sajor-caju mycelia were used for the recovery of uranium from aqueous solutions. The effect of pH, temperature, initial concentration of UO{sub 2} {sup 2+} ions and contact time parameters were investigated in a batch system. The particles sizes of the fungal mycelia were ranging from 100 to 200 {mu}m. Biosorption equilibriums were established in about 30 min and the correlation regression coefficients show that the adsorption process can be well defined by the Freundlich equation. The alkali treated form had a high biosorption capacity (378 mg/g) than those of the untreated (268 mg/g) and heat-treated fungal mycelia (342 mg/g). Optimum biosorption was observed at pH 4.5 for all the tested fungal preparations and was independent of temperature (5-35 deg. C). In addition, the polarity and surface energy of the fungal biomass film preparations were determined by contact angle measurement. The fungal biomass could be regenerated using 10 mM ...
We report the direct molecular dynamics simulations for molecular ball bearings composed of fullerene molecules (C{sub 60} and C{sub 20}) and multi-walled carbon nanotubes. The comparison of friction levels indicates that fullerene ball bearings have extremely low friction (with minimal frictional forces of 5.283 x 10{sup -7} and 6.768 x 10{sup -7} nN/atom for C{sub 60} and C{sub 20} bearings) and energy dissipation (lowest dissipation per cycle of 0.013 and 0.016 meV/atom for C{sub 60} and C{sub 20} bearings). A single fullerene inside the ball bearings exhibits various motion statuses of mixed translation and rotation. The influences of the shaft's distortion on the long-ranged potential energy and normal force are discussed. The phonic dissipation mechanism leads to a non-monotonic function between the friction and the load rate for the molecular bearings.
Electrodeposition of tertiary alumina/yttria/carbon nanotube (Al2O3/Y2O3/CNT) nanocomposite by using pulsed current has been studied in this investigation. Coating process has been performed on nickel sulphate bath and nanostructure of obtained compound layer is examined with high precision figure analysis of SEM nanographs. The effects of process variables, i.e., Y2O3 concentration, treatment time, frequency and duty cycle, have been experimentally studied. Statistical methods are used to achieve the minimum of corrosion rate and average size of nanoparticles. Finally the contribution percentage of different effective factors is revealed and confirmation run shows the validity of obtained results. Also it has been revealed that by changing the size of nanoparticles, corrosion properties o...
One aspect of the research program SFB 570 'Distortion engineering' is the in situ X-Ray diffraction analysis of phases and residual stresses during complete heat treatment cycles. These investigations result in experimental evidence available for the extensive computations. The optimisation of the instrumentation will be reported. A surface decarburisation of samples made from the ball bearing steel 100Cr6 could be avoided for a temperature range from 800 to 900 C and a holding time of one hour by a combination of evacuate the furnace and using a certain nitrogen flow as protective gas. At lower temperatures small amounts of ferrite caused by an increased diffusion rate of carbon lead again to a surface decarburisation up to a depth of 2 {mu}m. It was proved that with an evacuation of the X-Ray beam path at constant power of the X-Ray source the intensity of diffraction lines could be increased by more than a factor of 4. The ...
This paper examines the global impacts of a policy that internalizes the external costs (related to air pollution damage, excluding climate costs) of electricity generation using a combined energy systems and macroeconomic model. Starting point are estimates of the monetary damage costs for SO{sub 2}, NO {sub X} , and PM per kWh electricity generated, taking into account the fuel type, sulfur content, removal technology, generation efficiency, and population density. Internalizing these externalities implies that clean and advanced technologies increase their share in global electricity production. Particularly, advanced coal power plants, natural gas combined cycles, natural gas fuel cells, wind and biomass technologies gain significant market shares at the expense of traditional coal- and gas-fired plants. Global carbon dioxide emissions are lowered by 3% to 5%. Sulfur dioxide emissions drop significantly below the already low level. The ...
This paper examines the global impacts of a policy that internalizes the external costs (related to air pollution damage, excluding climate costs) of electricity generation using a combined energy systems and macroeconomic model. Starting point are estimates of the monetary damage costs for SO{sub 2}, NOX, and PM per kWh electricity generated, taking into account the fuel type, sulfur content, removal technology, generation efficiency, and population density. Internalizing these externalities implies that clean and advanced technologies increase their share in global electricity production. Particularly, advanced coal power plants, natural gas combined cycles, natural gas fuel cells, wind and biomass technologies gain significant market shares at the expense of traditional coal- and gas-fired plants. Global carbon dioxide emissions are lowered by 3% to 5%. Sulfur dioxide emissions drop significantly below the already low level. The policy ...
ObjectivesThe overall objective of the proposal is to test the conclusions reached in a recent article by Magnani, Mencuccini et al (2007), in which we proposed for the first time that the Net Ecosystem Productivity (NEP) of forests of the temperate and boreal region does not depend on temperature or rainfall but, rather, on nitrogen deposition (Ndep) from the atmosphere. It is widely accepted that Ndep can increase forest C sequestration, however the results from our 2007 paper reported a sensitivity dC/ [continued...]DescriptionCombustion of fossil fuels and use of fertilisers in agriculture has increased the amount of nitrogen compounds present in the atmosphere and the biosphere. More atmospheric nitrogen is converted into reactive nitrogen by anthropogenic activities than by all natural processes combined. This phenomenal historical increase in nitrogen deposition is responsible for several serious environmental problems, such as soil acidification and nitrogen saturation, nitrate ...
Proof-of-principle experiments are reported for a new concept in electrically rechargeable zinc-air battery. The zinc electrode is a porous flow-thru type using a copper foam metal substrate with zinc deposition onto the foam metal from concentrated zincate electrolyte (as used in zinc-slurry type batteries). The bifunctional air electrode employs low-cost materials, being fabricated entirely from carbon-based precursors and small amounts of nickel and/or cobalt oxide. Corrosion measurements on the graphite materials in the air electrode indicate sufficient corrosion resistance for 8000 h life on charge. A prototype single cell was constructed having 1.5 Ah capacity producing 1.2 V discharge -2.0 charge at the three hour rate and has produced stable voltages for more than 150 cycles. Based on the 1.5 Ah prototype characteristics, design calculations for a 32 kWh battery project an energy density of about 110 Wh/kg, peak power density of 140 ...
This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors from January 1997 to June 1997. Topics that have been investigated include (a) fatigue of carbon, low-alloy, and austenitic stainless steels (SSs) used in reactor piping and pressure vessels, (b) irradiation-assisted stress corrosion cracking of Types 304 and 304L SS, and (c) EAC of Alloys 600 and 690. Fatigue tests were conducted on ferritic and austenitic SSs in water that contained various concentrations of dissolved oxygen (DO) to determine whether a slow strain rate applied during various portions of a tensile-loading cycle is equally effective in decreasing fatigue life. Slow-strain-rate-tensile tests were conducted in simulated boiling water reactor (BWR) water at 288 C on SS specimens irradiated to a low fluence in the Halden reactor and the results were compared with similar data from a ...
An Allis-Chalmers, Model 2900, turbocharged diesel engine was converted to a dual-fuel engine in which ethyl alcohol was fumigated between the turbocharger and the intake manifold, and the diesel fuel was injected normally at a reduced rate. Tests were performed to determine if crankcase oil dilution that had occurred was caused by the following independent parameters: proof of the ethyl alcohol, crankcase oil temperature, engine load at maximum torque speed, and percentage of total energy in the form of ethyl alcohol. Engine tests were steady state for six hours, after which the crankcase oil was sampled for American Society for Testing and Materials (ASTM) laboratory tests for determination of flash points and fire points, water by centrifuge, water by distillation, and viscosity at room temperature. Results indicate a decrease in thermal efficiency and an increase in exhaust carbon monoxide as the percentage of total energy as alcohol is increased. Additional ...
Catalytic combustion has demonstrated the ability to provide low NO /SUB x/ emissions while maintainin high combustion efficiency. Recently, under joint NASA Lewis, EPA, and Acurex sponsorship, a catalytic reactor was tested for 1000 hours to demonstrate durability in combustion environments representative of advanced automotive gas turbine engines. At a 740K air preheat temperature and a propane fuel/air ratio of 0.028 by mass (/phi/FA = 0.44), the adiabatic flame temperature was held at about 1700K. The graded cell monolithic reactor measured 5 cm in diameter by 10.2 cm in length and was operated at a reference velocity of 13.4 m/s at 1 atmosphere pressure Measured NO /SUB x/ levels remained below 5 ppm while unburned hydrocarbon concentrations registered near zero and carbon monoxide levels were nominally below 20 ppm. The durability test included several parametric turndown studies and ended with a series of on/off cycling tests to further ...
The Partnership for a New Generation of Vehicles (PNGV) program intends to develop new designs for automobiles that will reduce fuel consumption by two thirds but otherwise have price, comfort, safety, and other measures of performance similar to the typical automobile now on the market. PNGV vehicle designs are expected to substitute lightweight materials, such as aluminum, magnesium, carbon-reinforced polymer composites, glass-reinforced polymer composites, and ultra- light steel, for heavier materials such as steel and iron in automobile components. The target mass of a PNGV vehicle is 1,960 pounds, as compared to the average current vehicle that weights 3,240 pounds. Other changes could include the use of different ferrous alloys, engineering changes, or incorporation of advanced ceramic components. Widespread adoption of these vehicle designs would affect materials markets and require concurrent development and adoption of supporting technologies to supply the ...
Chemical-looping combustion is a two-stage process proposed as an alternative for the combustion of carbonaceous materials, such as natural gas or coal gas, for almost complete CO{sub 2} capture. In the reduction stage, the structural oxygen contained in the lattice of a reducible inorganic oxide, is used for combustion of the carbonaceous material. In the regeneration stage the oxygen carrier, found in a reduced state after the reduction stage, is regenerated with pure air to recover the physical and chemical properties of the carrier, ready to reinitiate a new cycle reduction-regeneration. In a typical multicycle reactor test, the carriers are subjected to accumulative chemical and thermal stresses and the performance will, probably, decay progressively with the number of cycles. The occurrence of some side reactions may limit the efficiency of the overall process in CO{sub 2} capture. In this paper, titania-supported iron oxides with ...
A compartment model, including removal of organic matter in a forest ecosystem, is developed to describe matter cycling and net CO{sub 2} flux of the ecosystem especially of managed forests. The model consists of five carbon stocks: atmosphere, foliage, woody matter, underground matter, and dead organic matter in the soil. Employing appropriate values of ecophysiological parameters in the model and simulation of man-made sugi (Cryptomeria japonica D. Don) plantation forests shows that these forests have high growth potential with a maximum total phytomass of over 750 t ha{sup -1} in dry matter basis. When the typical pattern of thinning regime for sugi plantation forests in Japan is applied to the present model, the simulated forest biomass developments compare well with mensuration data from various forestry sites. The CO{sub 2} balance between the sugi forest ecosystem and the atmosphere reveals a net CO{sub 2} fixation of 49.38 million ton ...
The Chinese government has enacted policies to promote alternative vehicle fuels (AVFs) and alternative fuel vehicles (AFVs), including city bus fleets. The life cycle (LC), energy savings (ES) and GHG reduction (GR) profiles of AVFs/AFVs are critical to those policy decisions. The well-to-wheels module of the Tsinghua-CA3EM model is employed to investigate actual performance data. Compared with conventional buses, AFVs offer differences in performance in terms of both ES and GR. Only half of the AFVs analyzed demonstrate dual benefits. However, all non-oil/gas pathways can substitute oil/gas with coal. Current policies seek to promote technology improvements and market creation initiatives within the guiding framework of national-level diversification and district-level uniformity. Combined with their actual LC behavior and in keeping with near- and long-term strategies, integrated policies should seek to (1) apply hybrid electric technology to diesel buses; (2) ...
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 ...
In this investigation natural gas has been used as an alternative fuel in diesel engines. Experiments have been performed to study the performance of the dual fuel engine with different diesel quantities as pilot injection. It was suggested in this research that combustion in the dual fuel engine occurred in four stages: the delay period, the slow stage of combustion, the rapid stage of combustion and the fourth stage of combustion. Because of the slower flame speed of natural gas and also because of the prolonged delay period, the combustion of the gas-air continued well into the expansion stroke. These resulted in lower efficiency and higher brake specific fuel consumption, and also higher exhaust gas temperature and higher carbon monoxide in the exhaust when the engine ran on dual fuel. The carbon dioxide and black smoke in the exhaust decreased as the gas was introduced in the engine. The ratio of alternative to diesel fuel was varied at ...
The purpose of this DOE-funded effort is to develop continuous processes for solvent extraction of coal for the production of carbon products. These carbon products include materials used in metals smelting, especially in the aluminum and steel industries, as well as porous carbon structural material referred to as ''carbon foam'' and carbon fibers. During this reporting period, efforts have focused on the facility modifications for continuous hydrotreating, as well as developing improved protocols for producing synthetic pitches.
The Heat Cycle Research Facility (HCRF) is an experimental binary-cycle facility used to investigate different concepts and/or components for generating electrical power from a geothermal resource. This report briefly desc
Metazoan life cycles can be complex in different ways. A number of diverse phenotypes and reproductive events can sequentially occur along the cycle, and at certain stages a variety of developmental...Full Text Available
The work presented here demonstrates the ability of proton-transfer-reaction mass spectrometry (PTR-MS) to perform fast-response measurements of volatile organic compounds (VOCs) (including methanol, acetonitrile, acetaldehyde, acetone, PAN-type compounds, alpha- and beta-pinene, nopinone and pinonaldehyde) at the pptv level and its versatile applicability in the field of environmental trace gas analysis. Laboratory and field experiments including various calibration techniques and intercomparisons with other measurement techniques such as gas chromatography, atmospheric pressure chemical ionization and Fourier transformation infrared spectroscopy were performed providing a first characterization of the PTR-MS instrument performance (sensitivity, detection limit, precision, accuracy). Typically a detection limit (S/N=2) of 50 pptv for a 10 s signal integration time, a precision of 5 % and an accuracy in the range between 10 and 25 % were observed. Due to its compactness and ruggedness ...
A fuel cycle economic analysis was performed on four fuel cycles to provide a baseline for initial cost comparison using the Gen IV Economic Modeling Work Group G4 ECON spreadsheet model, Decision Programming Language software, the 2006 Advanced Fuel Cycle Cost Basis report, industry cost data, international papers, the nuclear power related cost study from MIT, Harvard, and the University of Chicago. The analysis developed and compared the fuel cycle cost component of the total cost of energy for a wide range of fuel cycles including: once through, thermal with fast recycle, continuous fast recycle, and thermal recycle.
The improvement in the functions of the viscous flow calculation method VEGA-SHIP around a ship and the expansion of application range were described as the numerical flow simulation in ship and ocean engineering and at the same time application examples to the ocean engineering by the general-purpose flow simulation code FLOW-3D handling the non-steady flow with a free surface were introduced as the numerical simulation regarding such products as a water gate and a dam. In the VEGA-SHIP, water surface was handled as a fixed wall so that wave could not be calculated. Therefore, an algorithm for calculating wave on the water surface was added to the VEGA-SHIP and a calculation method simultaneously considering the creation of wave around the ship and viscosity was developed. The FLOW-3D was used to calculate the phenomenon where inside liquid moved greatly due to the oscillation of a tank and hit against and damaged the tank ceiling in the tank, ...
Measurements of dissolved and atmospheric nitrous oxide (N{sub 2}O) are presented for three coastal environments: (1) the central North Sea, (2) the German Bight, and (3) the Gironde estuary. The contribution of coastal regions to the oceanic emissions of atmospheric N{sub 2}O were also determined. N{sub 2}O was measured with a gas chromatograph equipped with an electron capture detector and analyzed. The surface waters of the central North Sea and the German bight were found to be near equilibrium with the overlying atmosphere, while the mean saturation in the Gironde estuary was 132%. Mean saturations in coastal regions without estuaries or upwelling phenomena were only slightly higher than in the open ocean. When estuaries and regions with upwelling are included, however, approximately 60% of the oceanic N{sub 2}O flux is attributable to coastal regions. A review of published data indicated that previous studies have ...
A parameterized surface wave-induced vertical mixing (B"v) is incorporated into the Modular Ocean Model version 4 (MOM4). A comparison of the two numerical experiments with and without B"v shows that B"v can significantly improve the upper-ocean (20-100m) simulation in summer. The simulated upper-ocean temperature errors are reduced in summer due to the surface wave-induced vertical diffusive heat flux. The non-breaking-wave-induced vertical mixing can increase the probability of the simulated SST biases between -1^oC and 1^oC from 64% to 76% in the Southern Hemisphere (60^oS-10^oS) in January, and from 66% to 75% in the Northern Hemisphere (10^oN-60^oN) in July. The averaged mixed layer depth (MLD) simulated by the MOM4 without B"v is 14.4m shallower than the observations in 10^oS-60^oS i...
The tidal motion of the ocean water through the ambient magnetic field, generates secondary electric field. This motionally induced electric field can be detected in the sea or inland and has a potential for electrical soundings of the Earth. A first goal of the paper is to gain an understanding of the global distribution of the electric signal due to tidal ocean flow. We simulate the electric signals for two tidal constituents - lunar semidiurnal (M2) and diurnal (O1) tides. We assume a realistic Earth's conductivity model with a surface thin shell and 1-D mantle underneath. Simulations demonstrate that in some coastal regions the amplitudes of the electric field can reach 100 mV/km and 10 mV/km for M2 and O1 tides respectively. The changes of lithosphere resistance produce detectable changes in the tidal electric signals. We show that our predictions are in a good agreement with observations.
The central features of the mechanical cycle that drives the contraction of muscle are two translational steps: the working stroke, whereby an attached myosin crossbridge moves relative to the actin...Full Text Available
Many of the world's coral reefs suffered high coral mortality during the 1998 ENSO, with the highest mortality in the western Indian Ocean (WIO). A meta-analysis of field data on change in coral cover across the 1998 ENSO event was conducted for 36 major reef areas in the WIO, and relationship of the change with the historical sea-surface temperature (SST) variability investigated. WIO reefs were categorized into three major SST groups of differing coral cover change. Cover change was negatively associated with standard deviation (SD) SST until about SD 2.3, with increasing flatness of the SST frequency distributions. It increased with further increase in SD as the SST distributions became strongly bimodal in the Arabian/Persian Gulf area. The study indicates that environmental resistance/...
Remotely sensed ocean color data and numerical modeling have been used to study the phenology of both spring and fall phytoplankton blooms (FPBs) in the Nova Scotian Shelf (NSS)-Gulf of Maine (GoM) region. The ocean color data reveal a general pattern of westward progression of the spring phytoplankton bloom (SPB), and an eastward progression of the FPB in the NSS-GoM region. The spatial pattern of mean chlorophyll concentration in spring is similar to that in fall, with a lower concentration in the NSS and higher in the GoM. Interannually, there is a weak but significant tendency for years with earlier (delayed) SPBs to be followed by delayed (earlier) FPBs, but the mean chlorophyll concentrations during SPBs are not correlated with those during FPBs. The interannual variability of SPB ti...
The Offshore Comet is a modern offshore drilling rig with a hydraulic-cylinder-actuated jacking (raising and lowering) system. Hydraulic-cylinder jacking provides a safe and efficient method for placing the rig at the desired height above the water and insuring that it can withstand the expected heavy loads imposed by machinery, supplies, and the ocean environment. The drilling rig consists of a steel-hulled barge that is floated to the site and then supported during drilling operations by four steel triangular-cross-section lattice legs. The legs are planted firmly on the ocean bottom by a procedure called preloading. Each leg with its integral footing weighs 657 tons. The barge with its deck load can weigh up to 9200 tons.
In 1946, the Philippines raised claims in the South China Sea over an area already known as Spratly Islands. This claim advanced through peculiar stages, starting when Thomas Cloma allegedly discovered islands in 1946, later named as Freedomland, and maturing to some extent in 1978 by the governments claim over the so-called Kalayaan Island Group. Considered as an oceanic expansion of its frontiers, this paper reviews the basis of the claim, first over the nature of Clomas activities, and secondly over the measures the Philippine government took as a reaction of Clomas claim of discovery of an area already known in western cartography as the Spratlys. Eventually, what is the nature of the link between the 1978 Kalayaan Islands Groups official claim and 1956 Clomas private one?
Regional Ocean Modeling System (ROMS v 3.0), a three-dimensional numerical ocean model, was previously enhanced for shallow water applications by including wave-induced radiation stress forcing provided through coupling to wave propagation models (SWAN, REF/DIF). This enhancement made it suitable for surf zone applications as demonstrated using examples of obliquely incident waves on a planar beach and rip current formation in longshore bar trough morphology (Haas and Warner, 2009). In this contribution, we present an update to the coupled model which implements a wave roller model and also a modified method of the radiation stress term based on Mellor (2008, 2011a,b,in press) that includes a vertical distribution which better simulates non-conservative (i.e., wave breaking) processes and ...
The purpose of this paper is to check up a GPS (global positioning system) impact on scientific research activities of the Geodetic Society of Japan. First, it is mentioned that the conventional geoid-based concept of 'gravity anomaly' should be changed to a new definition, according to the GPS-determined ellipsoidal height system. Secondly, the results of many experiments, which have been made to monitor ocean-plate motions relative to the Japanese island-arcs, demonstrate that GPS is a powerful tool for obtaining temporal changes in horizontal displacement induced by the plate motion. Therefore, it is suggested that terrestrial measurements, such as triangulation and long-range leveling, would be replaced by GPS measurements in near future. Moreover, it is pointed out that GPS geodesy should play an important role in monitoring secular sea level trend due to global warming of the atmosphere and ocean. 19 refs., 4 figs.
Mesopelagic zooplankton may meet their nutritional and metabolic requirements in a number of ways including consumption of sinking particles, carnivory, and vertical migration. How these feeding modes change with depth or location, however, is poorly known. We analyzed fatty acid (FA) profiles to characterize zooplankton diet and large particle (>51?m) composition in the mesopelagic zone (base of euphotic zone ?1000m) at two contrasting time-series sites in the subarctic (station K2) and subtropical (station ALOHA) Pacific Ocean. Total FA concentration was 15.5 times higher in zooplankton tissue at K2, largely due to FA storage by seasonal vertical migrators such as Neocalanus and Eucalanus. FA biomarkers specific to herbivory implied a higher plant-derived food sou...
World demand for rare-earth elements and the metal yttrium?which are crucial for novel electronic equipment and green-energy technologies?is increasing rapidly. Several types of seafloor sediment harbour high concentrations of these elements. However, seafloor sediments have not been regarded as a rare-earth element and yttrium resource, because data on the spatial distribution of these deposits are insufficient. Here, we report measurements of the elemental composition of over 2,000 seafloor sediments, sampled at depth intervals of around one metre, at 78 sites that cover a large part of the Pacific Ocean. We show that deep-sea mud contains high concentrations of rare-earth elements and yttrium at numerous sites throughout the eastern South and central North Pacific. We estimate that an a...
The electrolyte was brought into contact with air and potassium carbonate was measured with various contact time in order to check the defect of carbon dioxide in the air on zinc-air cell. The relationship between potassium carbonate concentration in electrolyte and battery capacity was also studied. The potassium carbonate concentration in the electrolyte. The rate of carbon dioxide absorption was mainly affected by the pore size of hydrophobic membrane. Our study showed that adapting the pore of hydrophobic membrane decreased the loss of cell discharge performance due to the presence of carbon dioxide or water vapor in the atmosphere. 7 refs., 12 figs., 1 tab.
Carbon supported catalysts can lose their activity over a period of time due to the sintering of the nanometer-sized catalyst particles. The sintering of metal clusters on carbon supports can occur due to the weak interaction between the metal and the support and also due to the corrosion of carbon, especially in fuel cell electrocatalysts. The sintering may be reduced by increasing the interaction between the metal and the support and also by increasing the corrosion resistance of carbon supports. In an effort to mitigate the growth of the nanoparticles, carbon-substituted boron defects were introduced in the carbon lattice. The interaction between the Pt nanoparticles on the pure and boron-doped carbon supports was examined using X-ray photoelectron spectroscopy (XPS). The results indicate that the interaction between the Pt nanoparticles ...
Mineral carbonation is based on the reaction of carbon dioxide with metal-oxide bearing minerals, usually containing magnesium or calcium silicate, to form hardly soluble carbonates and other solid byproducts. The concept is based on acceleration of the naturally occurring rock weathering process. In the present work the calcium silicate is present in the mineral, wollastonite. To accelerate the process and make it potentially useful for practical applications, mineral carbonation is conducted here using an indirect two-step route in which the reactive component (Ca^2^+ ions in considered case) is first extracted from the mineral matrix and afterwards carbonated. Two solid byproducts are formed in this process: silica in the extraction step and calcium carbonate in the carbonation step. In...
Carbon-14 was analysed by direct absorption of carbon dioxide on the mixture of organic amine compound and scintillation cocktail then counted by low level liquid scintillation counter. This method can be applied for radiocarbon dating. In this study, the effects of carbon dioxide absorption, and counting efficiency were investigated using various commercial available cocktail. It was found that permafluor V and Ready Gel showed the highest carbon dioxide absorption whereas the Permafluor V showed the highest counting efficiency
The principle for working out the time-temperature schedule of the carbonization was determined through the investigation on the carbonization process of the green body and the phenol formaldehyde resin. During the carbonization process, the crack at lower temperatures is due to strain inhomogeneity produced in press. But the crack at higher temperatures results from the improper increasing rate of temperature. The application of the autoclave-carbonization process can increase the mechanical properties of the spherical fuel elements.
Wetlands can potentially sequester vast amounts of carbon. However, over 50% of wetlands globally have been degraded or lost. Restoration of wetland systems may therefore result in increased sequestration of carbon. Preliminary results of our investigations into atmospheric carbon sequestration by restored coastal wetlands indicate that carbon can be sequestered in substantial quantities in the first 2-50 years after restoration of natural hydrology and sediment accretion processes.
This critical review with 28 references examines absorption and emission in the v2 band of the carbon dioxide molecule at around the 15micron wavelength. The argument for additional infrared absorption, the enhanced greenhouse effect due to increased carbon dioxide concentrations, and radiation transport and increased emissions are discussed. Experiments studying the transmission spectra of pure carbon dioxide and carbon dioxide in nitrogen, and comparing them with the results of climate modelling using the HITRAN and GEISA databases, are described.
The safety analysis checklist scope and the criteria of key parameters needed to be checked for Daya bay reload cycles are introduced. The INCORE code package was used for the safety evaluation of Daya bay unit 2 cycle 2. The method and the contents can not only be applicable for Daya Bay reload cycles but also for Qinshan 600 MW and Qinshan 300 MW reload cycles.
The use of natural energy sources and their conversion to secondary forms of energy are a crucial base for the development of our society with its continuous change of requirements due to an increase in population and the broadening of the needs in our modern life. As a consequence the consumption of primary energy resources rose drastically worldwide during the last 5 decades in particular in the industrialized regions such as Europe. Parallel in time the increasing awareness of negative effects of fuel dependent pollution on the environment and the introduction of stringent emission control regulations about 3 decades ago initiated extensive development and retrofit activities resulting in the today applied high level state of the art. As an additional challenge the worldwide debate about the potential effects of the emission of the s.c green house gases on the global climate in particular carbon dioxide from the use of predominantly fossil fuels have initiated ...
Herbivores and pathogens impact the species composition, ecosystem function, and socioeconomic value of forests. Herbivores and pathogens are an integral part of forests, but sometimes produce undesirable effects and a degradation of forest resources. In the United States, a few species of forest pests routinely have significant impacts on up to 20 million ha of forest with economic costs that probably exceed $1 billion/year. Climatic change could alter patterns of disturbance from herbivores and pathogens through: (1) direct effects on the development and survival of herbivores and pathogens; (2) physiological changes in tree defenses; and (3) indirect effects from changes in the abundance of natural enemies (e.g. parasitoids of insect herbivores), mutualists (e.g. insect vectors of tree pathogens), and competitors. Because of their short life cycles, mobility, reproductive potential, and physiological sensitivity to temperature, even modest climate change will ...
This paper presents an investigation into the feasibility and potential advantages of a small scale Miller cycle natural gas engine for applications such as domestic combined heat and power systems. The Miller cycle engine is compared to a standard Otto cycle engine using cycle analyses and multidimensional simulation, and basic engine design implications are discussed. It is found that the Miller cycle engine has a potential for improved fuel efficiency, but at the cost of a reduced power to weight ratio. A fuel efficiency advantage of 5{yields}10% compared to a standard Otto cycle engine appears possible, however it is stated that further investigations, in particular into the topic of engine friction, are required in order to validate the findings. (author)
This paper presents an investigation into the feasibility and potential advantages of a small scale Miller cycle natural gas engine for applications such as domestic combined heat and power systems. The Miller cycle engine is compared to a standard Otto cycle engine using cycle analyses and multidimensional simulation, and basic engine design implications are discussed. It is found that the Miller cycle engine has a potential for improved fuel efficiency, but at the cost of a reduced power to weight ratio. A fuel efficiency advantage of Formula Not Shown compared to a standard Otto cycle engine appears possible, however it is stated that further investigations, in particular into the topic of engine friction, are required in order to validate the findings.
... This course is jointly taught between the School of Civil Engineering and the Environment and the School of Ocean and Earth Sciences. Scholarships 2 UK/EU fees only Scholarships are available for the academic year 2010/11. Awards will be given on the basis of merit. Flexible part-time study route available Back to top Home | About Us | Prospective Students |...
Part I of this thesis is on long-term iceberg collision-risk assessment methods for fixed offshore structures. Estimates for the long-term probability that an iceberg will hit a fixed offshore structure are based on estimates of the total volume of produced iceberg, a model for the size distribution of icebergs and a description of how iceberg trajectories ``fill`` the plane (the ocean`s surface). Part II of the thesis discusses methods for analysis of low resolution data in the sense that the size of the area covered by each pixel is not small compared to the dominating floes. Still, this type of data can provide estimates of the ice extent (and hence the ice edge) and ice concentration. The estimates of the ice edge (at least) seem to be physically significant in the sense that ``in some way`` they can reflect ice drift in an image time sequence. A priori this is far from obvious. A central idea is that the ``ice edge`` is close to a transition zone between two ...
The Subseabed Disposal Project (SDP) was part of an international program that investigated the feasibility of high-level radioactive waste disposal in the deep ocean sediments. This report briefly describes the seven-step iterative performance assessment procedures used in this study and presents representative results of the last iteration. The results of the performance are compared to interim standards developed for the SDP, to other conceptual repositories, and to related metrics. The attributes, limitations, uncertainties, and remaining tasks in the SDP feasibility phase are discussed.
... The National Oceanography Centre, Southampton is one of the world's leading research centres for the study of ocean and earth sciences. Southampton General Hospital One of the country's leading teaching hospitals and the base for the University's School of Medicine. Winchester School of Art Founded in 1863, Winchester School of Art is based 12 miles (20 kilometres) north of Southampton in the historic city of Winchester,...
Calls for containers to transport compressed natural gas, and a ship or barge to house some 200 employees in the Terra Nova offshore oilfield while the oil field's floating production, storage and offloading (FPSO) system is undergoing a major overhaul, are attracting attention on Canada's east coast offshore oilpatch. The FPSO is located offshore, 350 km east of St. John's, Newfoundland. Petro-Canada, operators of the FPSO anticipate that by having all required personnel nearby, the total shutdown time for the overhaul could be minimized. The CNG container was designed by Trans Ocean Gas Inc. in response to an invitation by Husky Oil and Petro-Canada, the White Rose field partners. Trans Ocean Gas strongly believes that CNG will become the technology of choice for getting natural gas ashore and to markets from stranded hydrocarbon pools in Atlantic Canada and the rest of the world where pipeline systems would be too ...
This report highlights the significance of the geological sciences to the nation and to society. Discussions include understanding plate tectonics and surface processes, exploring the continental crust, ocean basins and the deep earth, applications of geology to social problems such as mineral resources, waste disposal, siting of critical facilities, geological hazards, water resources management, and coastal zones. The state of health of geological research is also discussed. (ACR)
...Modern Languages Music Philosophy Faculty of Medicine Faculty of Medicine page Academic unit: Medicine Faculty of Natural and Environmental Sciences Faculty of Natural and Environmental Sciences page Academic units: Biological Sciences Chemistry National Oceanography Centre, Southampton Ocean and Earth Science Faculty of Physical and Applied Sciences Faculty of Physical and Applied Sciences page Academic units: Electronics and Computer Science Optoelectronics Research Centre Physics and Astronomy Faculty of Social and Human Sciences ...
... 01, 2009 | Rate It Marine Technology Society https://www.mtsociety.org/home.aspx emphasizes the importance of marine technology as it applies to global issues, encourages marine technology education and facilitates the use of marine technology in managing marine resources Added: Mar. 11, 2010 |...
In this activity, students will make a turbidity current. They will discover how fluids of differing densities interact with one another, learn some ways the densities of fluids can be changed and observe how density currents transport and deposit tremendous amounts of sediment in lakes and in the ocean. Additional options allow students to create and observe different kinds of density currents.
The oceanic bathypelagic realm (1000–4000 m) is a nutrient-poor habitat. Most fishes living there have pelagic larvae using the rich waters of the upper 200 m. Morphological...Full Text Available
...6 Resource type: reference data Global Change Master Directory An extensive source of information about satellite and in situ Earth science data, with broad coverage of the atmosphere, hydrosphere, oceans, solid earth, and biosphere. Author: NASA Subjects: climatology, global change, oceanographic data DeweyClass: 551.6 Resource type: documents, news International ...
DescriptionRemote sensing of the sea surface from satellites in near-polar orbits has contributed greatly to our understanding of the links between physical and biological processes in marine systems. However most of this progress has been made in open oceanic waters or major upwelling areas, and many unresolved problems are encountered in coastal regions and shelf seas. In these optically complex waters, quantitative remote sensing requires a more sophisticated interpretation strategy than that implemente [continued...
Resistive analogous meters for spatial and time characteristics in ocean agitation are most often used in practical oceanography in coastal zones but are based on bridge circuits determined to have shortcomings in their linearity range. This shortcoming is eliminated in the circuit of an instrument developed in an oceanographic laboratory (IMIO, Vana). Principle and block circuits are indicated, and static calibration curves are presented as are the correlative functions in the frequency spectrums obtained with the help of sea agitation recorded at a fixed point and at a depth of 6 meters.
Ammonia is a common and highly toxic pollutant which, in sufficient quantities, will adversely affect aquatic organisms. This ammonia criteria document for salt water will allow establishment of regulatory standards for ammonia discharge into estuaries, near coastal zones and oceans. Possible adverse impacts in highly sensitive and abundant ecosystems such as estuaries make regulation particularly important.
As part of an ongoing strategic research project to find barrels of radioactive waste off San Francisco, the U.S. Navy (USN), the U.S. Geological Survey (USGS), and the Gulf of the Farallones National Marine Sanctuary (GFNMS) pooled their expertise, resources, and technology to form a partnership to verify new computer enhancement techniques developed for detecting targets the size of 55 gallon barrels on sidescan sonar images. Between 1946 and 1970, approximately 47,800 large barrels and other containers of radioactive waste were dumped in the ocean west of San Francisco; the containers litter an area of the sea floor of at least 1400 km {sup 2} knows as the Farallon Island Radioactive Waste Dump. The exact location of the containers and the potential hazard the containers pose to the environment is unknown. The USGS developed computer techniques and contracted with private industry to enhance sidescan data, collected in cooperation with the GFNMS, to detect ...
Deteriorating air quality in urban areas is leading bus manufacturers to look for cleaner drives of urban buses. Various new systems are now available, but it is difficult to compare them and verify their effects without having a driving cycle accurately representing contemporary average urban bus use. The idealized form (engine cycle, passenger car cycle or different kW/tonnes ratio and traffic conditions) of existing driving cycles disqualifies them for the purpose. For this reason, it was decided to attempt the development of a new driving cycle for urban buses. To this end, measurements were carried out on buses in service in four major Dutch towns. The resulting data were combined to produce a reference cycle comprising all data relating to urban bus use. Statistical methods were then used to compare a large number of 15-20 minute ...
This report summarizes work performed on this project from October 2004 through March 2005. In previous work, a surfactant modified zeolite (SMZ) was shown to be an effective system for removing BTEX contaminants from produced water. Additional work on this project demonstrated that a compost-based biofilter could biodegrade the BTEX contaminants found in the SMZ regeneration waste gas stream. However, it was also determined that the BTEX concentrations in the waste gas stream varied significantly during the regeneration period and the initial BTEX concentrations were too high for the biofilter to handle effectively. A series of experiments were conducted to determine the feasibility of using a passive adsorption column placed upstream of the biofilter to attenuate the peak gas-phase VOC concentrations delivered to the biofilter during the SMZ regeneration process. In preparation for the field test of the SMZ/VPB treatment system in New Mexico, a pilot-scale SMZ system was also ...
Nuclear power plants of 20 units of in Korea are generating about 700 MTU of spent fuels annually. The inventory of spent fuels in Korea were estimated about 10,087.07 MTU at end of 2008, and the storage space of spent fuels won't be available any more at 2016 due to the saturation of the spent fuel pools in the plants. In addition, in order to reduce carbon emission and correspond to the enormous electricity demand in Korea, 8 units of nuclear power plants are under construction and several more plants are under planning. The 100,000 MTU of spent fuel inventory are expected by the year of 2095 in Korea. Therefore, short term and long term of spent fuel management plans are under discussion and implementation in Korea. As a short term of spent fuel management strategy for the target year of 2016, central or local spent fuel dry interim storage options are mostly under discussion. As a long term of management plan, fast reactor and advanced fuel ...
The Fast Flux Test Facility (FFTF) is a 400 MWt sodium-cooled fast reactor operated by Westinghouse Hanford Company for the US Department of Energy to conduct fuels and materials testing in support of the US Liquid Metal Fast Breeder Reactor programme. Early in 1982, the FFTF began its first 100 day irradiation cycle. Since that time the plant has operated very well, achieving a cycle capacity factor of 94 per cent in the most recent irradiation cycle. The authors describe the results achieved in the first three cycles of operation and carrying through to the fourth reactor cycle which began in January 1984. (author).
Kawasaki Heavy Industries, Ltd. has developed a gas turbine combined cycle and cogeneration plant computer aided engineering (CAE) system, which creates cycle heat balance automatically on given configurations of gas turbines, heat recovery boilers, steam turbines and auxiliaries. The system can predict the performance of the plant as a function of control set points, loads, process steam requirements and ambient conditions, which enables accurate and fast design of gas turbine combined cycle and cogeneration plants. (author)
The carbon-isotope ratio recently obtained for the carbon found in the Murchison meteorite, which has been shown (by the racemic nature of twelve component amino acids) to be free of terrestrial contamination,...Full Text Available
This patent describes a process for removing carbon dioxide from a feed stream of natural gas having at least methane, ethane and heavier. It comprises: first, separating the feed stream in a first separator to form a first stream having substantially all of the propane and heavier hydrocarbons and carbon dioxide and ethane and a second stream, having methane, carbon dioxide and ethane; separating the second stream in a second separator into a stream of carbon dioxide product and a third stream having ethane, methane and carbon dioxide: mixing at least a portion of the third stream with a polar compound; stream after the mixing in an absorber; separating the vapor and liquid of the third stream after the mixing in an absorber; absorbing the remaining unabsorbed carbon dioxide in a lean portion of the polar compound in the absorber, the absorber ...
Carbon dioxide is a waste product of aerobic cellular respiration in all aerobic life forms. PaCO2 represents the balance between the carbon dioxide produced and that eliminated. Hypocapnia...Full Text Available
A method of making high strength coke briquettes suitable for use as blast furnace coke comprising, (A) providing coal, (B) heating the coal at a temperature at or above the softening point of the coal to form partially carbonized char, (C) cooling the partially carbonized char below the softening point of the coal, (D) mixing the cooled partially carbonized char and tar to form a mixture of tar and partially carbonized char, (E) briquetting the mixture of tar and partially carbonized char to form briquettes of tar and partially carbonized char, (F) calcinating the briquettes to form high strength briquettes.
The compressive and torsional buckling behavior of carbon nanotube bundles at room temperature is examined with classical molecular dynamics simulation. The critical compressive load and stiffness of a single carbon nanotube in the bundle are found to be similar to those of individual carbon nanotubes. However, the critical torsional moment and stiffness of a single carbon nanotube in the bundle are found to be higher than those of individual carbon nanotubes. In addition, this study demonstrates that van der Waals interactions between the nanotubes in the bundle significantly affect the critical compressive load of the nanotube bundle.
This report presents a brief description of the fabrication and advantages of a composite, carbon-metal fiber material which does not require lubrication.
We prepared cathodes with various types of activated carbon and measured the cathodes' electrochemical performance according to the kind of activated carbon. Activated carbon supplies airflow channels and reaction sites in the cathode of zinc air batteries. When we use activated carbon with a high specific surface area as the cathode's catalyst substrate, we expect high electrochemical performance because this type of carbon provides more air flow channels and reaction sites. We focused on investigating the relationship between the cathode's pore structure and its electrochemical characterizations. We also studied the effects of the various activated carbon materials on the zinc air batteries' performance. Increasing the macropores or mesopores in the activated carbon resulted in achieving more power from ...
... rate on the tensile properties of SA-106 carbon steel pipe, in support of analysis and experimental modeling of postulated pipe whip in nuclear ...
... The fuel proposed was a medium-thermal carbon black-liquid JP-i1 mixture. JP-iO or exo-tetrahydrodi (cyclopentadieue) is a pure hydrocarbon with ...
Background:To determine nutrient requirements by the carbon oxidation techniques, it is necessary to know the fraction of carbon dioxide produced during the oxidative...Full Text Available
Ab initio planewave pseudopotential method is used to study carbon diffusion and pairing in crystalline silicon. The calculation is performed with a 40 Ry planewave cutoff and 2x2x2 special k-point sampling with a supercell of 64 atoms. It is found that substitutional carbon attracts interstitial Si forming a <001> C interstitial with a large binding energy of 1.45 eV. The interstitial carbon is mobile and can migrate with a migration energy of 0.5 eV. The interstitial carbon can bind further to another substitutional carbon forming a substitutional carbon-interstitutional carbon pair with a binding energy of 1.0 eV. This model is used to understand the effect of high C concentration on the transient enhanced diffusion in Si.
Studies were conducted of the bifunctional oxygen electrode. The development of a rechargeable metal-oxygen (air) cell has been hampered to a great extent by the lack of a stable and cost effective oxygen electrode capable of use during both charge and discharge. The first type of bifunctional electrode consists of two distinct catalytifc layers. The oxygen reduction catalyst layer containing a supported gold catalyst is in contact with a hydrophilic nickel layer in which evolution of oxygen takes place. Loadings of gold from 0.5 to 1.0 mg/cm/sup 2/ were investigated; carbon, graphite, metal, and spinel oxides were evaluated as substrates. The second part of the research effort was centered on developing a reversible oxygen electrode containing only one catalytic layer for both reduction and evolution of oxygen. The work was directed specifically to the study of perovskite type of oxides with the composition AA/sup 1/BO/sub 3/ where A is an element of the ...
Plutonium and minor actinides produced as by-products of the UO_2 nuclear cycle could be considered as waste or energy source depending on the strategy selected in the nuclear energy programme. Considering Pu and Minor Actinides as a source, they can be burned in existing water reactor for diminishing the radiotoxicity of the spent fuel, it is necessary to use 'inactive' materials as matrix like ThO_2. ThO_2 matrix has demonstrated its Pu burning efficiency and higher corrosion resistance than UO_2. Uranium-plutonium mixed oxide (MOX) fuel efficiency is low because the presence of U in MOX results in the creation of some new Pu under irradiation. The dissolution behaviour of irradiated (Th,Pu)O_2 pellets with burn-up of 38.8 MWd/kg Th has been studied in carbonated (20 mM HCO_3"-), deionised and granite ground water solution in a hot cell. The dissolution behaviour of Th, Pu, U and Np was studied in order to find out whether radionuclides ...
The Fredericksberg of South Florida may have a great oil potential that has been overlooked as a primary target in past decades. Previous exploration in the area has targeted the Lower Cretaceous oil-producing Sunniland Formation lower in the stratigraphic section. The Fredericksberg Dollar Bay Formation has hydrocarbon shows in many wells occurring in limestone biohermal deposits as well as in an upper dolomitic section. The Dollar Bay Formation is part of the Big Cypress Group of the Comanchean Series of the Lower Cretaceous. The Lower Cretaceous lithology is composed of evaporitic-carbonatecycles consisting of anhydrites, dolomites, and limestones. There are also present some calcareous shales, mudstones, salt, lignitic material, and carbonaceous material, especially in the anhydrite and limestone intervals. The limestones are usually micritic, chalky, calcarenitic, sometimes argillaceous, containing skeletal particles of gastropods, ...
The effect of liquefied natural gas on pollutant emissions was evaluated experimentally with used and new appliances in the laboratory and with appliances installed in residences, targeting information gaps from previous studies. Burner selection targeted available technologies that are projected to comprise the majority of installed appliances over the next decade. Experiments were conducted on 13 cooktop sets, 12 ovens, 5 broiler burners, 5 storage water heaters, 4 forced air furnaces, 1 wall furnace, and 6 tankless water heaters. Air-free concentrations and fuel-based emission factors were determined for carbon monoxide, nitrogen oxides, nitrogen dioxide, and the number of (predominantly ultrafine) particles over complete burns?including transient effects (device warm-up and intermittent firing of burners) following ignition--and during more stable end-of-burn conditions. Formaldehyde was measured over multi-burn cycles. The baseline fuel ...
Callus cultures derived from pith tissue of Nicotiana tobacum were grown on two media either under continuous illumination or in complete darkness. The first medium limited greening ability of callus grown in the light (3 milligrams per liter naphthalene acetic acid, 0.3 milligram per liter 2-isopentenylaminopurine, Murashige and Skoog salts, and 2% sucrose). The second medium encouraged chlorophyll synthesis (greening) though not shoot formation (0.3 milligram per liter naphthalene acetic acid; 0.3 milligrams per liter 2-isopentylaminopurine). To measure intracellular concentrations, calli were grown for 15 days on these standard media containing (U-/sup 14/C)sucrose. The dry weight proportions of the calli (as a fraction of fresh weight) and many metabolite concentrations nearly doubled in light-grown cells compared to dark-grown cells and increase 30 to 40% on low-auxin media relative to high-auxin media. Glutamine concentrations (from 4 to 26 millimolar) were very high, probably ...
The use of jojoba methyl ester as a pilot fuel was investigated for almost the first time as a way to improve the performance of dual fuel engine running on natural gas or liquefied petroleum gas (LPG) at part load. The dual fuel engine used was Ricardo E6 variable compression diesel engine and it used either compressed natural gas (CNG) or LPG as the main fuel and jojoba methyl ester as a pilot fuel. Diesel fuel was used as a reference fuel for the dual fuel engine results. During the experimental tests, the following have been measured: engine efficiency in terms of specific fuel consumption, brake power output, combustion noise in terms of maximum pressure rise rate and maximum pressure, exhaust emissions in terms of carbon monoxide and hydrocarbons, knocking limits in terms of maximum torque at onset of knocking, and cyclic variability data of 100 engine cycles in terms of maximum pressure and its pressure rise rate average and standard ...
The set of activities performed by SENTECH, Inc. addressed the specific recommendations provided to the Department of Energy (DOE) by its advisors, including the Hydrogen Technical Advisory Panel and the review panel members of the DOE Annual Hydrogen Program Review. SENTECH`s efforts were conducted under five tasks: Task 1: Technology and Process Analysis; Task 2: Hydrogen Information Development and Transfer; Task 3: Educational Products; Task 4: Systems Analysis; and Task 5: Life Cycle Costs. SENTECH activities were executed in two broad areas--analysis and technology transfer. The analytical tasks undertaken in FY97 were focused on two types of analysis--systems analysis and technical/economic assessments. These analytical activities benefit DOE by providing data that allow it to define the strategic goals of the hydrogen R and D program. By collecting analysis of the energy efficiency, environmental externality, and economic competitiveness factors of hydrogen ...
An experimental study was performed to provide the combustion and emission characteristics resulting from fuel-reactivity controlled compression ignition (RCCI) combustion mode utilizing dual-fuel approach in a light-duty, multi-cylinder diesel engine. In-cylinder fuel blending using port fuel injection of gasoline before intake valve opening (IVO) and early-cycle, direct injection of diesel fuel was used as the charge preparation and fuel blending strategy. In order to achieve the desired auto-ignition quality through the stratification of the fuel-air equivalence ratio ( ), blends of commercially available gasoline and diesel fuel were used. Engine experiments were performed at an engine speed of 2300rpm and an engine load of 4.3bar brake mean effective pressure (BMEP). It was found that significant reduction in both nitrogen oxide (NOx) and particulate matter (PM) was realized successfully through the RCCI combustion mode even without applying exhaust gas ...
This paper reported on a study in which a life cycle assessment (LCA) of cotton production in Australia was conducted to evaluate energy use and greenhouse gas (GHG) emissions from tillage to export shipping. The study showed that on-farm indirect cotton-farming is the most energy consuming component, consuming nearly 32.36 GJ/ha of energy. On-farm indirect cotton-farming is the most GHG emitting component, emitting about 1.64 tonne of carbon dioxide (CO{sub 2})/ha. Energy use and the emissions by off-farm direct cotton-farming were calculated as 5.09 GJ/ha and 0.14 tonne CO{sub 2}/ha respectively. Energy consumed by off-farm indirect farming was found to be 0.036 GJ/ha or 0.002 tonne CO{sub 2}/ha. The total energy usage and greenhouse gas emissions in the Australian cotton farming system were estimated to be 46.43 GJ/ha and 2.42 tonnes CO{sub 2}/ha for on-farm, and 5.13 GJ/ha and 0.145 tonne CO{sub 2}/ha for the off-farm sections. In total, ...
The suitability of the sunflower for biodiesel production was discussed in terms of the reference values on carbon dioxide equivalents (CO{sub 2eq}) emissions for every phase of the biofuels chain as indicated in the European Union (EU) Directive on renewable energies. A life cycle analysis performed on the agricultural phase of the sunflower showed that CO{sub 2eq} emissions from the cultivation phase exceeded the EU reference value. This paper highlighted the relevance of allocation methods to spread out energy consumption and CO{sub 2eq} emissions among sunflower biodiesel and oilcake. Allocation was made according to the principles of mass content, energy content and the economic value of co-products. The CO{sub 2eq} reductions obtained with the 3 methods were approximately 60, 50 and 25 per cent, respectively when compared to a case without allocation. Since these methods did not distinguish the different functionality of co-products in ...
White lupin (Lupinus albus L.) is an annual crop that has been used for phytostabilization of acidified multi-contaminated soils. Once the culture cycle is over, after shoot harvesting, a progressive transference of contaminants from roots to soil may take place as decomposition of roots occurs. An incubation experiment with Cu, Zn, Cd, and As-loaded roots of white lupin and soils with different pH values and concentrations of these contaminants from the area affected by a mine spill at Aznalcollar (near Seville, Spain) was performed in order to assess the effect of the decomposition of the roots to the pH and (NH_4)_2SO_4-extractable levels of these pollutants in the soils. Pollutants loaded-roots were mineralized (56 d) at a ratio similar to animal manures (15.8-19.4% of total organic carbon) in soil. The estimated root inputs of contaminants in comparison to their extractable concentrations in soil were high, especially in the control, ...
The aim of this work was to compare the electrochemical behaviors and safety performance of graphite and the lithium titanate spinel Li1.33Ti1.67O4 with half-cells versus Li metal. Their electrochemical properties in 1 M LiPF6/EC + DEC (1:1 w/w) or 1 M LiPF6/PC + DEC (1:1 w/w) at room and elevated temperatures (30 and 60 deg C) have been studied using galvanostatic cycling. At 30 deg C graphite has higher reversible capacity than Li1.33Ti1.67O4 when using the LiPF6/EC + DEC as electrolyte. At 60 deg C graphite declines in cell capacity yet Li1.33Ti1.67O4 remains almost unchanged. In a propylene carbonate (PC) containing electrolyte, graphite electrode exfoliates and loses its mechanical integrity while Li1.33Ti1.67O4 electrode is very stable. An accelerating rate calorimeter (ARC) and microcalorimeter have been used to compare the thermal stability of lithiated lithium titanate spinel and graphite. Results show that Li1.33Ti1.67O4 may be used ...
A solid electrolyte for lithium batteries requires several properties: a good ionic conductivity of about 10{sup -3} S/cm at 298 deg. K, a high cationic transport number (greater than 0.5), a redox stability window higher than 4.5 V, a good stability of the interface with the lithium electrode, and a sufficient mechanical stability. The family of gelled or hybrid electrolytes seems to meet all these requirements. Thus, a systematic study of the gelling of an ethylene carbonate and lithium bistrifluorosulfonimide (LiTFSI) based electrolyte has been carried out. The polymers used for gel or pseudo-gel synthesis are POE, PMMA and PAN which represent 3 different cases of interaction with the electrolyte. All the properties mentioned above have been studied according to the nature of the polymer and to the concentration of lithium salt, showing the advantages and drawbacks of each polymer. The possibility of using some of these gels in lithium-ion batteries has been ...
The electrochemical capacitor devices described in this report were deliverables from the US Department of Energy--Idaho Operations Office (DOE-ID) Contract No. DE-AC07-92ID13404 as part of the US Department of Energy`s (DOE) High Power Energy Storage Program. The Idaho national Engineering and Environmental Laboratory (INEEL) has responsibility for technical management, testing, and evaluation of high-power batteries and electrochemical capacitors under this Program. The DOE has developed various electrochemical capacitors as candidate power assist devices for the Partnership for a New Generation of Vehicles (PNGV) fast response engine requirement. This contract with Maxwell Energy Products, Inc. (Maxwell) was intended to develop a high-energy-density, high-power-density ultracapacitor that is capable of load leveling batteries in electric vehicles. The performance criteria for this device are delivery of 5 W {center_dot} h/kg of useful energy that can be used by the vehicle at an ...
The present article describes the features of the fully-fired combined cycles and the outline of the plant. Hitachi has optimized fully-fired combined cycle systems by executing a heat recovery type combined cycle. For the fully-fired combined cycles, it is possible to raise plant efficiency through the selection of adequate gas turbine types and cycles. It is possible to apply existing boiler facilities, fuel combustion systems, and stacks. It is possible to execute civil and architectural works on existing plants in-service as well as modification works during routine inspections. The NOx increment by gas turbine unit installations can be reduced by denitration plant modifications. Examples of the fully-fired combined cycles under planning are also introduced. Furthermore, the relational technique and operational characteristics are mentioned, as for ...
A life cycle assessment was performed to quantify the non-renewable (fossil) energy use and global warming potential (GWP) in electricity generation from a typical gas fired combined cycle power plant in Singapore. The cost of electricity generation was estimated using a life cycle cost analysis (LCCA) tool. The life cycle assessment (LCA) of a 367.5 MW gas fired combined cycle power plant operating in Singapore revealed that hidden processes consume about 8% additional energy in addition to the fuel embedded energy, and the hidden GWP is about 18%. The natural gas consumed during the operational phase accounted for 82% of the life cycle cost of electricity generation. An empirical relation between plant efficiency and life cycle energy use and GWP in addition to a scenario for electricity cost with varying gas prices and plant efficiency ...
A life cycle assessment was performed to quantify the non-renewable (fossil) energy use and global warming potential (GWP) in electricity generation from a typical gas fired combined cycle power plant in Singapore. The cost of electricity generation was estimated using a life cycle cost analysis (LCCA) tool. The life cycle assessment (LCA) of a 367.5 MW gas fired combined cycle power plant operating in Singapore revealed that hidden processes consume about 8% additional energy in addition to the fuel embedded energy, and the hidden GWP is about 18%. The natural gas consumed during the operational phase accounted for 82% of the life cycle cost of electricity generation. An empirical relation between plant efficiency and life cycle energy use and GWP in addition to a scenario for electricity cost with varying gas prices and plant efficiency ...
A unified model is presented for a class of combined energy systems, in which the systems mainly consist of a heat engine, a combustor and a counter-flow heat exchanger and the heat engine in the systems may have different thermodynamic cycle modes such as the Brayton cycle, Carnot cycle, Stirling cycle, Ericsson cycle, and so on. Not only the irreversibilities of the heat leak and finite-rate heat transfer but also the different cycle modes of the heat engine are considered in the model. On the basis of Newton's law, expressions for the overall efficiency and power output of the combined energy system with an irreversible Brayton cycle are derived. The maximum overall efficiency and power output and other relevant parameters are calculated. The general characteristic curves of the system are presented for some given parameters. ...
A process is described for removing carbon dioxide from a feed stream of natural gas, having at least methane, ethane and heavier hydrocarbon, comprising: separating the feed stream in a first separator to form a first stream, having substantially all of the propane and heavier hydrocarbons and carbon dioxide and ethane, and a second stream, having methane, carbon dioxide and ethane; mixing the second stream with a polar compound to form a third stream; separating the vapor and liquid of the third stream in the bottom portion of an absorber; absorbing carbon dioxide and ethane from the separated vapor of Step C in a lean portion of the polar compound in the absorber, the absorber carbon dioxide and ethane forming a fourth stream; separating the ethane from the polar compound and carbon dioxide in a separator; separating the first stream in a third separator to ...
An Otto cycle engine with internal and external irreversibilities of friction and heat leakage, in which the heat transfer between the working fluid and the environment obeys linear phenomenological heat transfer law [q ?? ?(T ?1)], is studied in this paper. The optimal piston motion trajectory for maximizing the work output per cycle is derived for the fixed total cycle time and fuel consumed per cycle. Optimal control theory is applied to determine the optimal piston trajectories for the cases of with and without piston acceleration constraint on each stroke and the optimal distribution of the total cycle time among the strokes. The optimal piston motion with acceleration constraint for each stroke consists of three segments, including initial maximum acceleration and final maximum decel...
Many aspects of cellular motility and mechanics are cyclic in nature such as the extension and retraction of lamellipodia or filopodia. Inherent to the cycles of extension and retraction that test the environment is the production of mechano-chemical signals that can alter long-term cell behavior, transcription patterns, and cell fate. We are just starting to define such cycles in several aspects of cell motility, including periodic contractions, integrin cycles of binding and release as well as the normal oscillations in motile activity. Cycles of local cell contraction and release are directly coupled to cycles of stressing and releasing extracellular contacts (matrix or cells) as well as cytoplasmic mechanotransducers. Stretching can alter external physical properties or sites exposed b...
The advantage of high-resolution sequence stratigraphy, which takes base-levels as reference, is that it can be applied to continental depositional basins controlled by multiple factors and can effectively improve the accuracy and resolution of sequential stratigraphic analysis. Moreover, the principles of base-level cycles are also suitable for analyzing sequential stratigraphy in continental coal-bearing basins because of their accuracy in forecasting distribution of coal measures. By taking the Dongsheng coalfield in the Ordos basin as an example, the extensive application of base-level cycles in exploration and exploitation of coal is analyzed. The result shows that the Yan'an formation in the Dongsheng area is a long-term base-level cycle which is bordered by nonconformities and made up of five mid-term cycles and 13 short-term cycles. The long-term ...
Carbon Black and activated carbon materials providing high surface areas and a distinct pore distribution are prime materials for supercapacitor applications at frequencies < 0.5 Hz. A number of these materials were tested for their specific capacitance, surface and pore size distribution. High capacitance electrodes were manufactured on the laboratory scale with attention to ease of processability. (author) 1 fig., 1 ref.
Layered carbon fiber mats have been prepared by layer-by-layer (LBL) electrospinning of polyacrylonitrile onto thin natural cellulose paper and subsequent carbonization. The layered carbon fiber mat has been proved to be a promising microbial fuel cell anode for high density layered biofilm propagation and high bioelectrocatalytic anodic current density.
The carbon content of silicon single crystals and polycrystals has been measured by charged particle activation analysis (CPAA) and infrared absorption. The authors obtained a linear relationship between the absorption coefficient at 605 cm/sup -1/ and the carbon content obtained by CPAA. They obtained a conversion factor of (1.00 +- 0.03) 10/sup 17//cm/sup 2/ for a 100% substitutional carbon.
The effect of sodium on the partial oxidation of methane over MoO{sub 3}-SiO{sub 2} in the presence of molecular oxygen has been investigated. As in the sodium-free case, the major products are formaldehyde, carbon monoxide, carbon dioxide, and water. Kinetic analysis indicates that methane is directly oxidized to formaldehyde and carbon dioxide. Formaldehyde is oxidized to carbon monoxide, which is itself further oxidized, providing an alternative route to carbon dioxide. The kinetic model shows that sodium poisons the direct oxidation of methane to formaldehyde and carbon dioxide, but promotes the oxidation of formaldehyde and carbon monoxide. Model predictions of rates and selectivities are in good agreement with the experimental data. A mechanism that explains both the poisoning and promotion effects of sodium on MoO{sub 3}-SiO{sub 2} is ...
In order to apply chemical-looping combustion to a practical power plant, carbon deposition on the solid particle is one of the key problems to be overcome. Six kinds of solid particles were examined to clarify the kinetic behavior of carbon deposition. The effects of the solid composition, feed gas composition, and reaction temperature on carbon deposition were investigated by thermogravimetrical reactor on the basis of NiO/YSZ particle. From the viewpoints of both reactivity and resistance against carbon deposition, the particle of NiO mixed with YSZ (i.e., yttria-stabilized zirconia) was found to be a good candidate for chemical-looping combustion. It has been observed that carbon deposition could be completely avoided with very low concentration of water vapor. By means of a proposed model, the condition that carbon deposition would be avoided was ...
In this work, a comprehensive model has been developed for the absorption of carbon dioxide into promoted hot potassium carbonate solution. The model, which is based on penetration theory, incorporates an extensive set of important reactions and takes into account the coupling between mass transfer and chemical kinetics. The penetration theory provides an appropriate absorption rate and enhancement factor for the chemical absorption. Operating data for carbon dioxide absorption into DEA-hot potassium carbonate solution has been compared with model predictions. The impact of parameters such inlet temperature of lean solution, promoter concentration, liquid split fraction, hot feed location and type of promoter on the performance of a split-flow absorber have been examined. The use of other promoters is an efficient way to enhance the carbon dioxide absorption, which has been ...
Air flow rates and carbon dioxide concentrations of air entering and exiting eight H-Area waste tanks were monitored for a period of one year. The average instanteous concentration of carbon dioxide in air is within the range reported offsite, and therefore is not affect by operation of the coal-fired power plant adjacent to the tank farm. Waste solutions in each of the tanks were observed to be continuously absorbing carbon dioxide. The rate of absorption of carbon dioxide decreased linearly with the pH of the solution. Personnel exposure associated with the routine sampling and analysis of radioactive wastes stored at SRP to determine the levels of corrosion inhibitors in solution could be reduced by monitoring the absorption of carbon dioxide and using the relationship between pH and carbon dioxide absorption to determine the free hydroxide concentration in ...
This paper describes the estimated the rate of carbon accumulation in the woody biomass and total carbon storage in the forests including trees, soil and litter in Korea. The relevant data come from the Statistical Yearbook of Forestry and major results of the studies on forest biomass in Korea. Most of the forests, which has been denuded or degraded during the 2nd World War and the Korean War, were recovered through ``Reforestation Project(1973-1987)`` and natural regeneration. So, now they are mostly young secondary forests and grow rapidly. Total carbon removal by forests is estimated at 8.1 million tonnes of carbon(MtC) and the carbon emission by commercial harvesting at 0.9 MtC. therefore, the forests in Korea play an essential role as a net carbon sink. The annul net carbon removal is 7.2 MtC and accounts for about 11.0% of total ...
Vulnerability to xylem embolism by freeze-thaw cycles and water stress was quantified in ring-porous (Quercus gambelii Nutt.), diffuse-porous (Populus tremuloides Michx.,...Full Text Available
We show here sodium ion cycling between complex I from Klebsiella pneumoniae and the F1F0 ATP synthase from Ilyobacter tartaricus in a reconstituted...Full Text Available
Most genetic changes that promote tumorigenesis involve dysregulation of G1 cell cycle progression. A key regulatory site in G1 is a growth factor–dependent restriction point (R) where cells...Full Text Available
This paper presents part-load evaluation of a natural gas-fired chemical looping combustion (CLC) combined cycle with CO2 capture. The novel combined cycle employs an air-based gas turbine, a CO2-turbine and a steam turbine cycle. In this combined cycle, the CLC reactors replace combustion chamber of the gas turbine. The proposed combined cycle has a net plant efficiency of about 52.2% at full-load, including CO2 compression to 200 bar. The part-load evaluation shows that reducing the load down to 60% results in an efficiency drop of 2.6%-points. However, the plant shows better relative part-load efficiency compared to conventional combined cycles. The pressure in CLC-reduction and -oxidation reactors is balanced by airflow control, using a compressor equipped with variable guide vanes. A combination of control strategies is discussed for plant start-up and ...
This presentation describes a method for analyzing, quantifying, and minimizing the total cost of fossil, combined cycle, and pumped hydro power plant cycling operation. The method has been developed, refined, and applied during engineering studies at some 160 units in the United States and 8 units at the Irish Electric Supply Board (ESB) generating system. The basic premise of these studies was that utilities are underestimating the cost of cycling operation. The studies showed that the cost of cycling conventional boiler/turbine fossil power plants can range from between $2,500 and $500,000 per start-stop cycle. It was found that utilities typically estimate these costs by factors of 3 to 30 below actual costs and, thus, often significantly underestimate their true cycling costs. Knowledge of the actual, or total, cost of cycling will ...
During the last 15 years cycles with CO{sub 2} capture have been in focus, due to the growing concern over our climate. Often, a natural gas fired combined cycle with a chemical absorption plant for CO{sub 2} capture from the flue gases have been used as a reference in comparisons between cycles. Neither the integration of the steam production for regeneration of amines in the combined cycle nor the off-design behaviour of such a plant has been extensively studied before. In this paper, the integration of steam production for regeneration of the amines is modelled at design load and studied in off-design conditions for a combined cycle. Different ambient conditions and part-load strategies and their influence on the cycle performance are also examined. Of particular interest is a novel strategy with the possibility of longer life of gas turbine blading, with ...
The hair follicle cycle successively goes through the anagen, catagen, telogen, and latency phases, which correspond, respectively, to hair growth, arrest, shedding, and absence before a new anagen...Full Text Available
Microstructural evolution due to thermal effects was studied in micro solder joints (55 {+-} 5 {micro}m). The composition of the Sn/Pb solder studied was found to be hypereutectic with a tin content of 65--70 wt%.This was determined by Energy Dispersive X-ray analysis and confirmed with quantitative stereology. The quantitative stereological value of the surface-to-volume ratio was used to characterize and compare the coarsening during thermal cycling from 0--160 C to the coarsening during annealing at 160 C. The initial coarsening of the annealed samples was more rapid than the cycled samples, but tapered off as time to the one-half as expected. Because the substrates to which the solder was bonded have different thermal expansion coefficients, the cycled samples experienced a mechanical strain with thermal cycling. The low-strain cycled samples had a 2.8% strain imposed on the ...
The Fast Flux Test Facility (FFTF) was designed to test fast-reactor fuels and other nonfuel materials. In its 37 reactor cycles of operations, the FFTF reactor has performed very well and successfully completed all the irradiation testings with an operating efficiency factor as high as 98%. Since FFTF is an experimental reactor, its core loading changed from cycle to cycle. Depending on the number of test assemblies in the core and their location, the core loading can change significantly from an essentially homogeneous core loading to a relatively nonhomogeneous or even highly localized heterogeneous loading. Consequently, the core reload design and initial criticality analyses were required for each operating cycle. The zero power initial critical control rod bank height was predicted before each reactor startup. The initial critical prediction depends on the reactivity conditions at the end of the ...
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 turbine (ALSTOM GT10C) ...
The photosynthetic activity of the green alga Scenedesmus quadricauda was investigated during synchronous growth in light/dark cycles. The rate of O2 evolution increased...Full Text Available
SummaryFor mammalian somatic cells the importance of microtubule cytoskeleton integrity in interphase cell cycle progression is uncertain. The loss, diminishment, or stabilization...Full Text Available
In this paper we have proposed a novel gas turbine cycle with hydrogen-fueled chemical-looping combustion, and the system study on two hydrogen-fueled power plants, the new gas turbine cycle and an advanced gas turbine cycle with H{sub 2}/O{sub 2} combustion, has been investigated with the aid of exergy principle (EUD methodology). The hydrogen fueled chemical-looping combustion in the new gas turbine cycle consists of two successive reactions: hydrogen fuel is reacted with metal oxide (reduction of metal oxide), and then instead of air or pure oxygen, the reduced metal is successively oxidized by the saturated air. As a result, the new hydrogen-fueled gas turbine cycle has a breakthrough performance, with at least about 12 percentage-point higher efficiency compared to the gas turbine cycle with H{sub 2}/O{sub 2} combustion, and will be environmentally superior ...
Rocket-Based Combined-Cycle (RBCC) engines intended for missiles and/or space launch applications incorporate features of rocket propulsion systems operating in concert with airbreathing engine cycles. Performance evaluation of these types of engines, which are intended to operate from static sea level take-off to supersonic cruise or accerlerate to orbit, requires ground test capabilities which integrate rocket component testing with airbreathing engine testing. A combined cycle engine test facility has been constructed in the General Applied Science Laboratories, Inc. (GASL) Aeropropulsion Test Laboratory to meet this requirement. The facility was designed to support the development of an innovative combined cycle engine concept which features a rocket based ramjet combustor. The test requirements included the ability to conduct tests in which the propulsive force was generated by rocket only, the ...
A high-voltage cathode initiates an electron emission, resulting in a reduction in the carbon dioxide concentration in exhaust gas from the burning of hydrocarbon fuel. Assuming that the observed carbon dioxide reduction is originated from the molecular decomposition, the energy needed for the endothermic reaction of this carbon dioxide reduction may stem primarily from the internal energy reduction in the exhaust gas in accordance of the first law of the thermodynamics. An oxygen increase due to the reduction in carbon dioxide in a discharge gas was observed in real time.
An analytical electron microscope study is presented on carbonaceous material in two chondritic porous aggregates, W7029* A and W7010* A2, from the Johnson Space Center Cosmic Dust Collection. The finding of well-ordered carbon-2H (lonsdaleite) in the two aggregates suggests that a record of hydrocarbon carbonization may be preserved in these materials. This carbon is a metastable phase resulting from hydrous pyrolysis below 300-350"0C and may be a precursor to poorly graphitized carbons in primitive extra terrestrial materials. (UK).
The interest of irradiation by carbon ions is in the fact that the carbon ions leave all their energy to a determined depth. ( phenomenon known under the name of Bragg peak)This high diffusion in tissue gives an RBE particularly high. The indications of this therapy are chordomas, and chondrosarcomas of the skull base, some cyst adenoid carcinomas, pulmonary cancer, sarcomas, hepato carcinomas, melanomas. In the light of results in term of efficiency, the place of irradiation by carbon ions should widen. (N.C.)
An experimental study was conducted to determine the effects of ply thickness in composite laminates on thermally induced cracking and changes in the coefficient of thermal expansion (CTE). After a few thermal cycles, laminates with thick-plies cracked, resulting in large changes in CTE. CTE`s of the thin-ply laminates were unaffected by microcracking during the first 500 thermal cycles, whereas, the CTE`s of the thick-ply laminates changed significantly. After about 1500 cycles, microdamage had also reduced the CTE of the thin-ply laminates to a value of about half of their initial value.
For the development of a rechargeable zinc/air battery, La{sub 0.6}Ca{sub 0.4}CoO{sub 3}-catalyzed (perovskite) bifunctional oxygen electrodes and pasted zinc electrodes were prepared and tested in monopolar zinc/air cells. The cells were cycled in moderately alkaline electrolyte. The maximum power as well as the cycle life of the cells were investigated. Up to 450 cycles could be reached, and attractive specific energies and powers were obtained. (author) 3 figs., 4 refs.
ObjectivesThe overall aim of the proposed research is explicit in the project title, i.e. the creation of a map of current vertical land movements in the UK based on an optimal combination of absolute gravity (AG) and continuous GPS (CGPS). This is consistent with specific objective (ii) of WP1.9 of the Oceans 2025 programme and is related to priority topic area 4 (application of satellite geodesy to sea level science) of the NERC Strategic Ocean Funding Initiative (SOFI). From long term geological an [continued...]DescriptionThe proposed research aims to create a map of current vertical land movements in the UK based on an optimal combination of estimates from two geodetic surveying and monitoring techniques; the measurement of absolute gravity (AG) and the use of high precision, continuous GPS (CGPS) observations. From long term geological and geophysical studies, vertical land movements in the UK are thought to be of the order of 1 to 2 ...
In 1982 the semi-submersible drilling unit Ocean Ranger capsized and sank off the Grand Banks, resulting in the loss of the entire 84-man crew. A Royal Commission was set up to conduct an enquiry into the incident, and to carry out a process of research and opinion-gathering towards providing recommendations to both federal and Newfoundland governments. The primary purpose of the Commission was to determine why the Ocean Ranger sank, why none of the crew were saved, and how to avoid similar disasters. A number of studies and seminars were held to focus expert knowledge and opinion in several key fields and to update studies and fill gaps in the data base. Summaries of selected study reports and the seminar proceedings are presented in the following areas: the environment, including ice, marine climatology, weather forecasting services, wave climatology, oceanographic information, and seabed information; design, including mobile offshore ...
The adsorption capacity of radionuclides onto suspended sediment was experimented on each of the coastal seawater sampled around the Kori and the Wolsung nuclear power plant. During the experiment the quantity and size fraction of suspended sediment were adjusted and the seawater and sediment chemistry is approximated to the expected field condition. Because the sorption capacity depends on the specific minerals, ocean chemistry and radionuclide involved, it is necessary to analyze sediment mineralogy. Clay mineral is dominant in seabed mineral and suspended sediment as the result of x-ray diffraction. Radionuclide sorbed to silty-clay mineral can be rather transported to ocean than scavenged to seabed because of low quantity and fine grained suspended sediment in the coast around the Kori and the Wolsung. The result of adsorption examinations shows that {sup 139}Ce and {sup 51}Cr and {sup 110m}Ag are strongly sorbed to suspended particle, ...
The adsorption capacity of radionuclides onto suspended sediment was experimented on each of the coastal seawater sampled around the Kori and the Wolsung nuclear power plant. During the experiment the quantity and size fraction of suspended sediment were adjusted and the seawater and sediment chemistry is approximated to the expected field condition. Because the sorption capacity depends on the specific minerals, ocean chemistry and radionuclide involved, it is necessary to analyze sediment mineralogy. Clay mineral is dominant in seabed mineral and suspended sediment as the result of x-ray diffraction. Radionuclide sorbed to silty-clay mineral can be rather transported to ocean than scavenged to seabed because of low quantity and fine grained suspended sediment in the coast around the Kori and the Wolsung. The result of adsorption examinations shows that "1"3"9Ce and "5"1Cr and "1"1"0"mAg are strongly sorbed to suspended particle, while ...
The authors have discovered chert xenoliths from green rocks in the Pippu area, central Hokkaido, Japan. Reports were given on the discovery with regard to the state of its production, chemical composition of the green rocks, and radiolarian fossils produced from the chert and their age. Considerations were given on the geological significance thereof. On 23 green rocks and five cherts out of the collected samples, rock slices were prepared, and petrographic statement was made by using a polarizing microscope. In addition, the whole petro-chemical composition analysis was performed on green rocks to discuss the radiolarian fossils and geological ages. The following conclusions were obtained as a result: green rocks may be identified as a product of igneous activities in a large plate in a certain period from the latter Callovian period of the middle age of the Jurassic period to the Barremian period of the Paleozoic era in the Cretaceous period; and their formation field should have ...
A simple analytical/numerical model has been developed for computing the evolution, over periods of up to a few hours, of the current and temperature profile in the upper layer of the ocean. The model is based upon conservation laws for heat and momentum, and employs an eddy diffusion parameterisation which is dependent on both the wind speed and the wind stress applied at the sea surface. Other parameters such as the bulk-skin surface temperature difference and CO$_2$ flux are determined by application of the Molecular Oceanic Boundary Layer Model (MOBLAM) of Schluessel and Soloviev. A similar model, for the current profile only, predicts a temporary increase in wave breaking intensity and decrease in wave height under conditions where the wind speed increases suddenly, such as, for example, during gusts and squalls. The model results are compared with measurements from the lagrangian Skin Depth Experimental Profiler (SkinDeEP) surface ...
Platinum Group Element (PGE) concentrations in garnet pyroxenite xenoliths from Oahu, Hawaii, are significantly lower than those in mantle peridotites and show fractionated patterns (e.g. PdN/OsN=2-10, PdN/IrN=4-24; N=chondrite normalized) and very high ReN/OsN ratios (9-248). Mass balance calculations show that the bulk rock pyroxenite PGE inventory is controlled by the presence of sulfide phases. The 187Os/188Os ratios of these pyroxenites vary from subchondritic to suprachondritic (0.123-0.164); and the 187Os/188Os ratios show good correlations with bulk rock and clinopyroxene major and trace element compositions, and bulk rock PGE and sulfur abundances. These observations suggest that the Os isotope compositions in these pyroxenites largely reflect primary processes in the oceanic mant...
The cell cycle-regulatory transcription factor E2F-1 is regulated by interactions with proteins such as the retinoblastoma gene product and by cell cycle-dependent alterations in E2F-1 mRNA abundance....Full Text Available
The possibility of having properly designed multinational fuel cycle agreements which would contribute to public acceptance of nuclear energy are explored. The advantages of existing international cooperation in the field of uranium enrichment and nuclear waste disposal and reprocessing are discussed. The possible forms of multinational co-operation under an international organisation, committed the non-proliferation and operating under international law and covering storage facilities, security of raw materials and the nuclear fuel cycle are summarised in model form. (U.K.).
The fuel management study on 18-months fuel cycle project is introduced for Daya Bay Nuclear Power Station. Station from the selection of the objective of fuel management for 18-months cycle, the method used and the analysis done are explained in detail to reach the final loading pattern chosen
The state of chromatin during the cell cycle was examined using synchronized cultures of CHO hamster cells. Results support Mazia's dynamic chromosome cycle model and indicate that DNA-interactive chemotherapeutic agents elicit different types of kinetic responses in treated cells, suggesting a degree of specificity of interaction between various alkylating and intercalating agents and the genome. Effects of sarkosyl crystals, heparin, and chemotherapeutic agents, neocarzinostatin and adriamycin, on chromation are discussed. (HLW)
We propose a dynamical model for business cycle based on an optimal DI model. In the model there exists a conserved quantity, which corresponds to the total energy in a dynamical system. We found that the business cycle with the period 6 or 7 years is nicely reproduced, since the model predicts a periodic motion in the conservative system.
Laser-Doppler anemometry was used to investigate mean flow and turbulence fields in a direct injection diesel engine, motored at speeds of 1500, 2250 and 3000 rev/min. Both cycle-resolved and ensemble-averaged measurements were made in the upper part of the cylinder during the inlet and compression strokes. The cycle-resolved measurements in the inlet stroke are discussed in this paper.
18-Months cycle reload design verifications of Daya Bay NPS is briefly described. It was attempted giving the description of analysis scope and key technology for a nuclear power plant which will be changed fuel management strategy from one year to 18-months cycle
Two researchers, Tom Goreau of the Discovery Laboratory in Jamaica and Raymond Hayes of Howard University, claim that they have evidence that nearly clinches the temperature connection to the bleached corals in the Caribbean and that the coral bleaching is an indication of Greenhouse warming. The incidents of scattered bleaching of corals, which have been reported for decades, are increasing in both intensity and frequency. The researchers based their theory on increased temperature of the seas measured by satellites. However, some other scientists feel that the satellites measure the temperature of only the top few millimeters of the water and that since corals lie on reefs perhaps 60 to 100 feet below the ocean surface, the elevated temperatures are not significant.
This paper describes the phenomenology of nuclear explosions and technologies for their detection as relevant to On-Site Inspection (OSI) for a comprehensive test-ban (CTB). Our experience with the US nuclear test program which has been primarily carried out at the Nevada Test Site (NTS) and in the Pacific Ocean. The goals of OSI are to resolve ambiguous events, reduce uncertainty, deter attempts at evasion, and provide responsive and technically competent means of confirming the occurrence of a nuclear explosion should deterrence fail. These goals would include finding evidence of an evasive nuclear explosion or evidence that the event was non-nuclear, such as an earthquake or large chemical explosion.
A shock absorber mechanism and method for use on the leg structure of a jack-up offshore drilling rig is described. It is mounted on the bottom of each existing leg of a drilling rig and comprises a pointed piston member which is positioned on the bottom of the leg structure and projects downwards through the can/footing of the rig leg. The piston member is held in place by a resilient tension member which is designed to absorb shock forces during vertical/axial impact of the leg structure when contact is made with the ocean floor. (author).
The theme of the conference was recent developments in airborne remote sensing and their applications. The proceedings contain the papers presented at 14 general sessions and 13 interactive sessions covering airborne platforms, sensor systems, airborne/spaceborne synergy, atmospheric and oceanic measurements, land cover/land use, emergency response and reconnaissance, data handling, forestry, agriculture, water resources, geospatial reference, system calibration, environmental monitoring and planning, and information product advancements. Two papers are abstracted separately.
In the United States, economic growth increasingly requires that greater volumes of freshwater be made available for new users, yet supplies of freshwater are already allocated to existing users. Currently, water for new users is made available through re-allocation of xisting water supplies-for example, by cities purchasing agricultural water rights. Water may also be made available through conservation efforts and, in some locales, through the development of ''new'' water from non-traditional sources such as the oceans, deep aquifer rackish groundwater, and water reuse.
... (restricted)] 251-260 Revisiting new variant famine: the case of Swaziland by Scott Naysmith & Alex Waal & Alan Whiteside [Downloadable! (restricted)] 261-269 Food prices and the HIV response: findings from rapid regional assessments in eastern and southern Africa in 2008[InlineMediaObject not available: see fulltext.][InlineMediaObject not available: see fulltext.] by Stuart Gillespie & Paul Jere & John Msuya & Scott Drimie [Downloadable! (restricted)] 271-289 Declining global per capita agricultural production and warming oceans ...
... (restricted)] 319-341 The value of container terminal investment to ocean carrier strategy by Thomas Pawlik & Lars Stemmler & Alfred J Baird ... (restricted)] 142-173 Prediction of arrival times and human resources allocation for container terminal by Gianfranco Fancello & Claudia Pani & Marco Pisano ... (restricted)] 347-369 Analysis of berth allocation and inspection operations in a container terminal by Yongpei Guan & Kang-hung Yang [Downloadable! (... (restricted)] 237-262 Container terminal concessions: A game theory application to the case of the ports of Pakistan by Naima Saeed & Odd ...
...assistantship in Suburban Ecology Location: Bedford, NY Deadline: August 15, 2008 Postdoctoral Fellow in energy Location: University of Waterloo, Ontario, Canada Deadline: August 11, 2008 Junior Professional Fellowship Sustainable Development Governance Programme Location: UNU, Yokohama, Japan Deadline: August 1, 2008 Center for Ocean Solutions Early Career Fellowship Program Location: Stanford, California Deadline: July 15, 2008 Asian MetaCentre for Population and Sustainable Development Analysis Postdoctoral Research Fellow Location: Singapore Deadline: July 15, ...
A study for Cs-137 radionuclide dispersion in the marine environment through of compartmental model (Box Model) is presented. The model simulates the surface water contamination caused by direct atmospheric deposition, surface wash off, desorption from sediments and transfer with the ground water of accidentally released radionuclides. For this study the model was applied to the North Sea, near to Sellafield, based on the transfer coefficients obtain at the literature. The results obtained are in good agreement with the literature, being that the model developed can be applied in to the brazilian coastal regions. (author). 7 refs, 7 figs.
In 2009 the European Space Agency satellite mission GOCE (Gravity Field and Steady-State Ocean Circulation Explorer) was launched. Its objectives are the precise and detailed determination of the Earth's gravity field and geoid. Its core instrument, a three axis gravitational gradiometer, measures the gravity gradient components V xx , V yy , V zz and V xz (second-order derivatives of the gravity potential V) with high precision and V xy , V yz with low precision, all in the instrument reference frame. The long wavelength gravity field is recovered from the orbit, measured by GPS (Global Positioning System). Characteristic elements of the mission are precise star tracking, a Sun-synchronous and very low (260 km) orbit, angular control by magnetic torquing and an extremely stiff and thermally stable instrument environment. GOCE is complementary to GRACE (Gravity Recovery and Climate Experiment), another satellite gravity mission, launched in 2002. While ...
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 ...
Lithium ion batteries use an oxide as a positive electrode and a carbon material as a negative electrode. The performances of carbon electrodes have rapidly evolved during the last years thanks to the substitution of soft carbons of Conoco or MCMB-2510 type by graphites (F-399, MCMB-2528) and then by hard carbons. These high capacity carbons (700 mAh/g) have higher service life and volume capacity than graphites but their irreversible losses are greater (>20%). In this work, materials with similar electrochemical performances are prepared by mechanical crushing. Mechanical crushing allows to obtain a wide range of carbon materials with various morphologies, specific surfaces and levels of disorder. The formation of the passivation film is directly linked with the surface of materials. A reaction scheme of the reversible and irreversible capacities has been ...
Tensile properties of reduced-activation 10Cr-30Mn austenitic steels with carbon levels from 0.003 to 0.55% were investigated over the temperature range from room temperature to 873 K after neutron irradiation in the Japan Materials Testing Reactor at 573 K to 8.5x10"2"2 n/m"2. Irradiation-induced increase in yield stress increased significantly with carbon concentration up to about 0.1% and it was constant above 0.1% carbon. A high density of dislocation loops with small (below 10 nm) and large (20-30 nm) sizes formed during irradiation. The high density, small loops caused a large irradiation hardening, while the large loops contributed only slightly to irradiation hardening. It was considered that carbon atoms formed the small loops together with irradiation defects. The deformation channeling was observed in the irradiated high carbon steels, 0.11 and 0.55% ...
Many sunspot cycles are double peaked. In 1967 Gnevyshev suggested that actually all cycles have two peaks generated by different physical mechanisms, but sometimes the gap between them is too short for the maxima to be distinguished in indices of the total sunspot activity. Here we show that indeed all cycles have two peaks easily identified in sunspot activity in different latitudinal bands. We study the double peaks in the last 12 sunspot cycles and show that they are manifestation of the two surges of toroidal field - the one generated from the poloidal field advected all the way on the surface to the poles, down to the tachocline and equatorward to sunspot latitudes, and another one generated from the poloidal field diffused at midlatitudes from the surface to the tachocline and transformed there into toroidal field. The existence of these two surges of toroidal field is due to the relative ...
Concepts involving combined gas-turbine/steam-turbine power-generation plants, in which the fuel gas for the gas turbine is produced via the gasification of coal, are now extremely advanced. This technology already permits efficiencies of around 50% current development targets view 65% as achievable. In conventional technology, efficiencies are tied to conditions, such as air and cooling-water temperatures, at the particular location. In combined-cycle power plants, the properties of the fuel coal also play an important part. There are, in face, coals which can be more advantageously used in a combined-cycle power plant than in a conventional one. These differences, combined with advantageous concepts for coal-fired combined-cycle power-generating plants, are presented and analyzed. Particular attention is devoted to individual losses occurring at coal conversion, thermodynamic cycles, integration of ...
A series of hydrogenation/dehydrogenation cycles have been performed on palladium wire samples, stressed by a constant mechanical tension, in order to investigate the changes in electrical and mechanical properties. A large increase of palladium electrical resistivity has been reported due to the combined effects of the production of defects linked to hydrogen insertion into the host lattice and the stress applied to the sample. An increase of the palladium sample strain due to hydrogenation/dehydrogenation cycles in ????? phase transitions is observed compared to the sample subjected to mechanical tension only. The loss of initial metallurgical properties of the sample occurs already after the first hydrogen cycle, i.e. a displacement from the initial metallic behavior (increase of the resistivity and decrease of thermal coefficient of resistivity) to a worse one occurs already after the first hydrogen ...
A new process engineering flowsheet reflecting an improved design of the LASL Bismuth Sulfate thermochemical cycle is presented. The design is based on laboratory data that indicate a lowered endothermic heat load for a partial decomposition of the solid bismuth sulfate. A small electrical energy demand should result from operation of the sulfur dioxide electrolytic step at lower acid concentration, in principle. The results of the flowsheeting analysis yield a thermal efficiency of 50% for the cycle when coupled to a conceptual fusion energy heat source at 1500/sup 0/K. A parametric analysis shows a slight drop in efficiency as the temperature of the heat source is decreased. The LASL Bismuth Sulfate thermochemical cycle appears to have potential as a means of producing hydrogen from high-temperature heat sources such as fusion, fission, and solar energy; it also appears to be competitive with alternative thermochemical ...
Long life cycles covering more than one year are known for all orders of insects. There are different mechanisms of prolongation of the life cycle: (1) slow larval development; (2) prolongation of the adult stage with several reproduction periods; (3) prolongation of diapause; (4) combination of these mechanisms in one life cycle. Lasting suboptimal conditions (such as low temperature, low quality of food or instability of food resources, natural enemies, etc.) tend to prolong life cycles of all individuals in a population. In this case, the larvae feed and develop for longer than a year, and the active periods are interrupted by dormancy periods. The nature of this dormancy is unknown: in some cases it appears to be simple quiescence, in others it has been experimentally shown to be a tru...
The closed-cycle hydrogen-oxygen PEM regenerative fuel cell (RFC) at Nasa Glenn Research Center has successfully demonstrated closed-cycle operation at rated power for multiple charge/discharge cycles. During the charge cycle the RFC has absorbed input electrical power simulating a solar day cycle ranging from zero to 15 kWe peak, and delivered steady 5 kWe output power for periods exceeding 8 h. Orderly transitions from charge to discharge mode, and return to charging after full discharge, have been accomplished without incident. The RFC is beginning to demonstrate its potential as an energy storage device for aerospace solar power systems such as solar electric aircraft, lunar and planetary surface installations - any airless environment where minimum system weight is critical. This hard...
Tunable output wavelength is an important character of a free electron laser (FEL). As generally understood, to alter the wavelength of a high-gain harmonic generation (HGHG) FEL laser, the seed laser must be tunable. A few-cycle, high intensity laser obtained by optical compression usually has pretty broad bandwidth in the spectral domain, which can be used as the seed laser of a HGHG and may open the possibility to approach a HGHG scheme with fully tunable wavelength. In this paper, a HGHG FEL seeded by a few-cycle laser is theoretically discussed and numerically investigated. A few-cycle seed laser significantly influences HGHG FEL performance, especially in output wavelength tuning. For a HGHG FEL seeded by a 4-cycle 786 nm laser, output wavelength tunability range up to 14.9% of the central wavelength 262 nm is observed by adjusting the resonant condition.
The objective of this study is to analyze the effects of heat loss characterized by a percentage of the fuel's energy, friction and variable specific heats of working fluid on the performance of an air standard Otto cycle with a restriction of maximum cycle temperature. A more realistic and precise relationship between the fuel's chemical energy and the heat leakage that is based on a pair of inequalities is derived through the resulting temperature. The variations in power output and thermal efficiency with compression ratio, and the relations between the power output and the thermal efficiency of the cycle are presented. The results show that the power output as well as the efficiency where maximum power output occurs will increase with increase of the maximum cycle temperature. The temp...
Japan's basic nuclear policy is to reprocess spent fuel and to effectively use the recovered plutonium and uranium. MOX fuel utilization in LWRs is promoted in 16-18 reactors by FY2015. Commercial operation of Rokkasho Reprocessing Plant is planned to start in 2012. Prototype reactor 'Monju' restarted operation in May 2010. From FY 2007, Fast Reactor Cycle Technology Development Project (FaCT project) started which focuses more toward the commercialization stage FBR cycle. Basic scenario of Japan's R and D aims for realization of demonstration FBR by around 2025 and introducing commercial FBRs before 2050. Smooth transition from LWR fuel cycle to FBR one is an important point. For nuclear fuel cycle which requires long term R and D, human resources development and keeping is vitally important. (author)
The Fast Flux Test Facility (FFTF) core loading during its ninth operating cycle was significantly different from that of previous cycles because of the presence of the Core Demonstration Experiment (CDE). The CDE consists of a number of axially blanketed fuel assemblies and internal blankets prototypic of advanced oxide cores in Liquid Metal Reactors (LMR). In preparation for the Cycle 9 reload design effort, a careful assessment of control rod worth and reactivity calculations for Cycles 1 through 8 was made. The goal of this study was to establish calculational biases and reduce uncertainties factored into the reload design calculations. These analyses helped assure that the operational objectives for Cycle 9 were met.
The Fast Flux Test Facility (FFTF) core loading during its ninth operating cycle was significantly different from that of previous cycles because of the presence of the Core Demonstration Experiment (CDE). The CDE consists of a number of axially blanketed fuel assemblies and internal blankets prototypic of advanced oxide cores in Liquid Metal Reactors (LMR). In preparation for the Cycle 9 reload design effort, a careful assessment of control rod worth and reactivity calculations for Cycles 1 through 8 was made. The goal of this study was to establish calculational biases and reduce uncertainties factored into the reload design calculations. These analyses helped assure that the operational objectives for Cycle 9 were met.
Biodiesel is produced from vegetable oils that have been chemically modified by esterification; an example is rapeseed oil methyl ester (RME), made by treating rapeseed oil with methanol. Biodiesel can be burned directly in diesel engines. Oil from the rapeseed variety known as 00 was the first type of vegetable oil used for transesterification to produce biodiesel. Many other oils have been used successfully as biodiesel feedstock including sunflower oil in Southern France and Italy, soybean oil in the USA, and palm oil in Malaysia. Biodiesel can be made from a wide range of feedstock and multi-feedstock blends. Compared to conventional diesel biodiesel has some environmentally friendly advantages, e.g. biodiesel is reported to release fewer solid particles. Potentially even more important is the low level of carbon dioxide generation associated with biodiesel, at a time when CO{sub 2} emissions are falling in every industrial sector except transport. ...
This report describes the accomplishments of the University of Georgia in establishing an academic program geared toward the emerging biobased products industry. By virtue of its strengths and structure, the University of Georgia is particularly well-suited for developing a program focused on plant- and microbial-based bioproducts, and it was in this general area that this program was developed. The program had several unique characteristics. First, we implemented a distinguished lecture series that brought outstanding scientists and engineers to our University to interact with students and share their vision of the biobased economy. Second, we offered industrially-oriented and multidisciplinary courses that provided students with a broad background on various facets of biobased business and technology. Third, we provided the students with opportunities to expand beyond the classroom by engaging in research lab rotations and industrial internships. Fourth, each student was engaged in a ...
Uniaxial low-cycle fatigue and creep-fatigue tests have been carried out on hollow alloy 800 specimens that were filled with steam. Two testing temperatures were employed, each with its own steam condition. These temperatures and steam conditions were 650/sup 0/F with saturated steam (5% liquid, 95% vapor) and 1200/sup 0/F with superheated steam at 2200 psi. The low-cycle fatigue tests were carried out at both 650/sup 0/F and 1200/sup 0/F by cycling the strain between equal tensile and compressive magnitudes until specimen failure or until it was no longer practical to continue the test. The creep-fatigue tests were carried out to failure by cycling the strain in the same fashion as in the low-cycle fatigue tests but with holds imposed at either the peak tensile strain or the peak compressive strain or at both peak tensile and compressive strains in each loading ...
This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this ``soluble`` zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated ...
This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this soluble'' zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc ...
The LiMnO{sub 2} lamellar oxide, obtained by exchange reaction from its sodium homologue {alpha}-NaMnO{sub 2}, has been used as a positive electrode for lithium batteries. After the first electrochemical cycle, the shape of the potential-composition curve changes and indicates a change in the structure. This modification changes imperceptibly at each cycle and after about 40 cycles, a stationary state is reached. Powder spectra refinement using the Rietvelt method shows a migration of manganese ions from the thin sheets towards the inter-sheet space. After a single cycle, 8% of the manganese ions are already present in the lithium site and this rate reaches 13% after 3 cycles. During long cycling, a redistribution of ions and vacancies inside the cfc oxygenated pile leads to a structure very similar to the LiMn{sub 2}O{sub 4} spinel. This structure evolution is ...
Characteristic study for the recycled fuel cycle, MOX fuel and Th-MOX fuel in PWR was performed with the comparison of 4 w/o UO2 fuel. It was assumed that there are no limit in reprocessing and no technical difficulty in recycling of spent fuel. The effect of recycling, plutonium composition, conversion ratio, MTC, FTC was investigated to each cycle. (Th+Pu)O_2 recycle option was advantageous because the loading amount of plutonium could be reduced from 8.3 w/o at once-through cycle to 3.5 w/o. (Th+Pu)O_2 recycled fuel was known to be higher Pu-239 consumption rate and more Pu-240(242) production rate. The (Th+U)O2 and (U+Pu)O2 once-through fuel cycle revealed high conversion ratio. The (U+Pu)O_2 recycled fuel cycle, however, showed low conversion ratio. Safety of each cycle was ensured by negative MTC and FTC
Treatment of coal or coconut shell activated carbons with either phosgene or chlorine at 180{degree}C followed by washing with methanol or water results in chlorinated carbons with very similar pore structures to their precursors. Water adsorption experiments show that the modified materials are relatively hydrophobic, presumably as a result of replacement of oxygen-containing surface groups by chlorine. Adsorption of the model hydrophobic vapour chloropicrin from humid air is usually better for the modified carbons which, unlike the controls, do not appear to be subject to degradation in performance on ageing in a humid atmosphere. The stability of the modified carbons is probably a consequence of the chlorination of those sites on the control carbons that are prone to ready oxidation or hydroxylation. 1 tab., 2 figs., 17 refs.
This issue of Carbon Market Perspectives on 'Pathways for implementing REDD+: Experience from carbon markets and communities' discusses the role of carbon markets in scaling up investments for REDD+ in developing countries. Nine articles authored by experienced negotiators on REDD+, carbon market actors, project developers and other leading experts share experiences and make suggestions on the key elements of a future international REDD+ regime: Architecture and underlying principles, measuring, reporting and verification (MRV), private-sector involvement, the rights of indigenous people and local communities, biodiversity conservation and environmental integrity. The articles are grouped under three main topics: the lessons of existing REDD+ projects; the future REDD+ regime and the role of carbon markets; and experiences and ideas about the involvement of ...
Comparatively evaluates methods for removal of carbon dioxide from waste gases emitted from industrial plants. The evaluations concentrate on carbon dioxide absorption by water solutions of alkalis and amines. The Hindered Amines Process, developed by Exxon in the USA, is analyzed. Chemical reactions of carbon dioxide absorption in solutions with hindered amines are evaluated. The following US patents which protect processes for carbon dioxide absorption by means of hindered amines are evaluated: No. 4,112,052, No. 4,101,633, No. 4,112,051, No. 4,100,257, No. 4,112,050, No. 4,094,957. Efficiency of carbon dioxide removal by each of the processes is pointed out. 12 refs.
Carbon black is widely used as an active filler in the rubber industry to improve the physical properties of rubber. The surface energy of carbon black is high compared to that of various elastomers like styrene?butadiene rubber (SBR), butadiene rubber (BR) and ethylene?propylene?diene rubber (EPDM). The work aims at reducing the surface energy of carbon black by modifying its surface for application especially in rubber blends. The present paper looks into the possibility of using plasma polymerisation of acetylene as a surface modification technique for carbon black in comparison with silica. Thermogravimetric analysis, wetting behaviour with various liquids of known surface tension and time of flight secondary ion mass spectrometry (ToF-SIMS) were used to characterise the carbon black b...
Polyacrylonitrile (PAN)-based carbon fabric (CF) was modified with strong HNO3 oxidation and then introduced into polyimide (PI) composites. The friction and wear properties of the carbon fabric reinforced polyimide composites (CFRP), sliding against GCr15 stainless steel rings, were investigated on an M-2000 model ring-on-block test rig under dry sliding. Experimental results revealed that the carbon fiber surface treatment largely reduced the friction and wear of the CFRP. Compared with the untreated ones, the surface-modified CF can enhance the tribological properties of CFRP efficiently due to the improved adhesion between the CF and the PI matrix. Scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) study of the carbon fiber surface showed that the fiber surfa...
Methane and carbon dioxide are the two main constituents of biogas. Biogas also contains traces of nitrogen, hydrogen, oxygen and hydrogen sulphide. When diesel engine runs on biogas, the combustion is poor as compared to diesel fuel. One of the reasons of poor combustion is the presence of carbon dioxide in the biogas. Percentage of methane and carbon dioxide in biogas varies with maturities of feed stock, temperature, water content, loading rate of raw material and bacterial actions. This paper examines the effect of variations of carbon dioxide in biogas on the performance of the engine to simulate the performance of the engine running with biogas from different sources (varying proportion of methane and carbon dioxide). (Author)
A decontamination washer for working dresses using liquid and supercritical carbon dioxide were designed and manufactured. The size of reactor for decontamination and solidification is about 16 liter. The system is a closed one with recycling ability of carbon dioxide. The efficiency of recycling of carbon dioxide and that of separation of solutes in carbon dioxide were checked. They met all the design goals. A remote control system of the carbon dioxide flow was set in a control panel. The manufactured decontamination washer was brought to Wolsung nuclear power plants, and installed to check the efficiency of decontamination and the feasibility of usage in nuclear power plants. The elimination of radioactive oil from the contaminated dresses were very high. However, the decontamination factor was lower than the design goal value. It's due to the low removal rate of ...
The moment analysis of pulse responses was applied to a biological activated carbon (BAC) bed to evaluate the microbial activity. Glucose and activated carbon fiber (ACF) were employed in experiments as a model tracer and an activated carbon respectively. No significant difference in biodegradation rates of glucose by microorganisms attached on different solid supports such as activated carbon inactivated carbon and glass fibers was observed. However, higher microbial activity was obtained from microorganisms supported on the ACF in terms of the apparent degradation of total organic including metabolic byproducts by microorganisms, since part of the metabolic byproducts was irreversibly deposited onto the ACF. 11 refs., 6 figs.
The adsorption of CO2 on a number of activated carbons, thermal carbon black, and oxide materials at 195 K was studied using static and dynamic techniques. The landing surface areas ?(CO2) ? 0.19 nm2 on thermal carbon black and the absolute values of sorption for P/P 0 < 0.4 were determined. The density of adsorbed CO2 in the micropore volume was estimated at ?(CO2) = 0.91 g/cm3. It was demonstrated that the previously found effect of a weakening of the sorption interaction of nitrogen molecules with thin-walled materials (which manifested itself in an analysis of sorption isotherms by a comparative method) was pronounced to a lesser degree for the sorption of CO2. At the same time, the presence of supermicropores in activated carbon samples resulted in overestimated values of surface area...
Preliminary observations on the isothermal carbon transfer in low-carbon Alloy-800 exposed in sodium with AISI-304 type of steel at 550_0 are reported. The alloy was found to undergo a carburization comparable or slightly lower than that observed for the AISI-304 stainless steel for carbon activities above 6 x 10 /sup -3/ at 550_0C, but was not found to decarburize below such a carbon activity value. In the examined range the chemical composition of the alloys does not affect the process out of the experimental uncertainty of measure. Conclusions concerning the effective diffusion for carbon in the alloy are formulated. Preliminary relationships were found for an empirical evaluation of the carburization of the Alloy-800 in sodium of known carbon activity.
In this study the technical and economical possibilities of burning carbon monoxide (CO) of the flue gas and utilizing of the released heat in hot air cupola furnace used for melting have been studied. As basis for examining was burning of cleaned furnace...
This study was designed to evaluate the suitability of a novel bioabsorbable material in treating bone defects. A poly(desaminotyrosyl-tyrosine-ethyl ester carbonate) (PDTE carbonate) membrane (thickness...Full Text Available
The present invention relates to a method of recycling polymeric waste products into monomers and high value forms of carbon by pyrolytic conversion using an induction coupled RF plasma heated reactor.
Porous carbon with high surface area and pore volume was prepared by a reverse replication process and its toluene equilibrium adsorption behavior was investigated. The preparation process of the porous carbon was composed of following sub-processes in series: synthesis and template preparation of silica gel, impregnation and polymerization of DVB monomer in silica template, carbonization of DVB polymer in a silica-polymer composite, and HF-assisted selective etching of silica in carbon-silica composite, The prepared porous carbon was nano porous and had ultrahigh specific surface area (2007 m{sup 2}/g) and large pore volume (3.07cm{sup 3}/g). The nanoporous carbon showed rapid toluene adsorption rate and good toluene adsorption capacity, compared with a commercial Y-type zeolite, In the present study, a reverse replication process to prepare nanoporous ...
A study in northeast Germany has shown that the establishment of short rotation coppices (SRC) of Robinia pseudoacacia L. may be a viable option for improving farmers income on marginal soils. The plantations produce woody biomass at a fast rate for energy use. Carbon is accumulated in the harvestable biomass, as well as in the stump and the roots. These plant compartments form a long-term carbon storage pool because they can survive a harvest, stay vital at the site and continue to grow as the plant ages. As organic litter decomposes, additional carbon is sequestered under SRC as soil organic carbon. The carbon sequestration in SRC of R. pseudoacacia on mining sites within the Lower Lusatian region in northeast Germany was studied and the results were complemented with findings of current field studies conducted on reclaimed mine sites. The average above ground dry matter ...
Recently we have found that carbon nano-materials have ability to recognize softer actinides(III). In this presentation, separation of americium(III) from lanthanides(III) by chromatography with carbon nano-materials, such as carbon nano-tubes and graphite, has been investigated by batch adsorption experiments and chromatography. The separation factor (SF) between americium(III) and lanthanide(III) was about 2 in the range of pH from 1 to 4 by using carbon nano-tube, graphite and activated charcoal. The separation factor depended on the diameter of carbon nano-tubes. Smaller one, 3-20 nm diameter, showed the best selectivity for americium(III), which separation factor was about 2.0, although larger one, 40-70 nm, showed almost no selectivity. The same behavior has been observed by using graphite powder and activated charcoal although acid- or alkali pretreated activated charcoal ...
Carbon nanotubes (CNTs) are considered one of the most promising materials in nanotechnology, with attractive properties for many technologic applications. The different synthesis, purification, and...Full Text Available
BackgroundThe precision in carbon ion radiotherapy depends on the calibration of Hounsfield units (HU) as measured with computed tomography (CT) to water equivalence. This calibration...Full Text Available
The acetogenic bacterium Clostridium thermoaceticum ATCC 39073 grew at the expense of the two-carbon substrates oxalate and glyoxylate. Other two-carbon substrates (acetaldehyde, acetate,...Full Text Available
Recent work has indicated that the suppression of boron transient enhanced diffusion (TED) in carbon-rich Si is caused by nonequilibrium Si point defect concentrations, specifically the undersaturation of Si self-interstitials, that result from the coupled out-diffusion of carbon interstitials via the kick-out and Frank--Turnbull reactions. This study of boron TED reduction in Si{sub 1-x-y}Ge{sub x}C{sub y} during 750{sup o}C inert anneals has revealed that the use of an additional reaction that further reduces the Si self-interstitial concentration is necessary to describe accurately the time evolved diffusion behavior of boron. In this article, we present a comprehensive model which includes {l_brace}311{r_brace} defects, boron-interstitial clusters, a carbon kick-out reaction, a carbon Frank--Turnbull reaction, and a carbon interstitial-carbon substitutional ...
Recent work has indicated that the suppression of boron transient enhanced diffusion (TED) in carbon-rich Si is caused by nonequilibrium Si point defect concentrations, specifically the undersaturation of Si self-interstitials, that result from the coupled out-diffusion of carbon interstitials via the kick-out and Frank--Turnbull reactions. This study of boron TED reduction in Si_1_-_x_-_yGe_xC_y during 750"oC inert anneals has revealed that the use of an additional reaction that further reduces the Si self-interstitial concentration is necessary to describe accurately the time evolved diffusion behavior of boron. In this article, we present a comprehensive model which includes #left brace#311#right brace# defects, boron-interstitial clusters, a carbon kick-out reaction, a carbon Frank--Turnbull reaction, and a carbon interstitial-carbon substitutional (C_iC_s) ...
A laboratory differential simulation method is used for the design of carbonization columns at coal-tar processing in which phenols are regenerated from phenolate solution by carbon dioxide absorption. The design method is based on integration of local absorption rates of carbon dioxide along the column. The local absorption rates into industrial phenolate mixture are measured in a laboratory model contactor for various compositions of the gas and liquid phases under the conditions that ensure the absorption rates in the laboratory absorber simulate the local rates in the industrial column. On the bases of the calculations, two-step carbonization columns were designed for 30000 t/year of the phenolate solution treatment by carbon dioxide. The absorption proceeds at higher pressure of 500 kPa and temperatures from 50 to 65 C, pure carbon dioxide is used and ...
We have isolated a second gene (MLS1), which in addition to DAL7, encodes malate synthase from S. cerevisiae. Expression of the two genes is specific for their physiological roles in carbon and nitrogen...Full Text Available
Concentration of an amine solution for removal of hydrogen sulfides and carbon dioxide from natural gas, is tested by carbon dioxide absorption measurement in an apparatus allowing complete reaction to give reliable results.
Several inexpensive and non-toxic solvents with low vapour pressures were investigated for their suitability as alternative solvents for the absorption of carbon dioxide from flue gas. The solvents include poly(ethylene glycol)s, poly(ethylene glycol) ethers, poly(ethylenimine) and glycerol-based substances. Solvent properties such as thermal stability, solubility of carbon dioxide and selectivity over nitrogen were investigated in a systematic study using a thermogravimetric analyser. Absorption results are reported for pure carbon dioxide and nitrogen as well as a mixture of both gases. Desorption and long-term sorption behaviour are also discussed. Glycerol and poly(ethylene glycol)s show a high solubility of carbon dioxide. Due to the high viscosity of the solvent, carbon dioxide absorption in poly(ethylenimine) is very slow in spite of the presence of favourable amine groups. ...
A process is claimed for selectively preparing alpha-olefins having from 2 to about 22 carbon atoms by contacting a gaseous mixture containing carbon monoxide and hydrogen with an iron titanate alkali metal hydroxide catalyst at reaction conditions correlated so as to favor the formation of a substantial proportion of such alpha-olefin product.
Rationale: Ventilator-induced lung injury (VILI) leads to an unacceptably high mortality. In this regard, the antiinflammatory properties of inhaled carbon monoxide (CO) may provide...Full Text Available
The goal of this DOE Vision-21 project work scope is to develop an integrated suite of software tools that can be used to simulate and visualize advanced plant concepts. Existing process simulation software does not meet the DOE's objective of ''virtual simulation'' which is needed to evaluate complex cycles. The overall intent of the DOE is to improve predictive tools for cycle analysis, and to improve the component models that are used in turn to simulate the cycle. Advanced component models are available; however, a generic coupling capability that will link the advanced component models to the cycle simulation software remains to be developed. In the current project, the coupling of the cycle analysis and cycle component simulation software will be based on an existing suite of programs. The challenge is to ...
A series of ball-on-disc wear and friction measurements were made for surfaces which have a chemical vapour deposition carbon silicon alloy layer on a carbon substrate (fine grain POCO graphite). Nitrogen ion irradiation was used to improve the wear resistance of the carbon alloy surface. For comparison, measurements were also taken for alumina against alumina. It was found that the lowest friction coefficient and lowest wear occurred for ion irradiated coated samples containing 4% Si in the alloy and that the performance was superior to that of alumina. ((orig.))
A series of ball-on-disc wear and friction measurements were made for surfaces which have a chemical vapour deposition carbon silicon alloy layer on a carbon substrate (fine grain POCO graphite). Nitrogen ion irradiation was used to improve the wear resistance of the carbon alloy surface. For comparison, measurements were also taken for alumina against alumina. It was found that the lowest friction coefficient and lowest wear occurred for ion irradiated coated samples containing 4% Si in the alloy and that the performance was superior to that of alumina. ((orig.)).
Research activity during the 1991--1992 funding period has been concerned with the following topics relevant to carbon monoxide activation. (1) Exploratory studies of water gas shift catalysts heterogenized on polystyrene based polymers. (2) Mechanistic investigation of the nucleophilic activation of CO in metal carbonyl clusters. (3) Application of fast reaction techniques to prepare and to investigate reactive organometallic intermediates relevant to the activation of hydrocarbons toward carbonylation and to the formation of carbon-carbon bonds via the migratory insertion of CO into metal alkyl bonds.
Research activity during the 1991--1992 funding period has been concerned with the following topics relevant to carbon monoxide activation. (1) Exploratory studies of water gas shift catalysts heterogenized on polystyrene based polymers. (2) Mechanistic investigation of the nucleophilic activation of CO in metal carbonyl clusters. (3) Application of fast reaction techniques to prepare and to investigate reactive organometallic intermediates relevant to the activation of hydrocarbons toward carbonylation and to the formation of carbon-carbon bonds via the migratory insertion of CO into metal alkyl bonds.
The accuracy of the carbon 14 dating method is dependent on the fluctuations of carbon 14 in the atmosphere over long periods of time. Fossil corals that are dated by both carbon 14 and uranium-thorium methods allows the setting of calibration curves for the carbon 14 method for the last 50.000 years. The uranium-thorium method is based on the measurement of the ratio of 2 isotopes: thorium 230 and uranium 234 that are both present in the decay chain of uranium 238. (A.C.)
A billet of low-density carbon-bonded carbon fiber (CBCF) composite is machined into a desired attenuator or load element shape (usually tapering). The CBCF composite is used as a free-standing load element or, preferably, brazed to the copper, brass or aluminum components of coaxial transmission lines or microwave waveguides. A novel braze method was developed for the brazing step. The resulting attenuator and/or load devices are robust, relatively inexpensive, more easily fabricated, and have improved performance over conventional graded-coating loads.
A process is claimed for selectively preparing a mixture of two-carbon atom oxygenated hydrocarbons, namely, acetic acid, ethanol and acetaldehyde, by continuously contacting a gaseous reaction mixture containing hydrogen and carbon monoxide with a solid catalyst comprising rhodium in combination with one or more alkali metals selected from the group consisting of lithium, potassium, cesium and rubidium at reaction conditions correlated so as to favor the formation of a substantial proportion of such two-carbon atom products.
... interactive surfaces and interfaces, and 3) the more complex a ... carbonate or calcium phosphate with a thin interface ... diameter) for nerve prosthesis. ...
Mixed microstructures have been studied in low- carbon microalloyed steels suitable for automotive applications, after continuous cooling from the hot-rolled condition. Microstructural features such as polygonal ferrite, bainitic and acicular ferrite and microphase constituent are identified using transmission electron microscopy. The influence of these mixed structures on the tensile strength, impact toughness and fracture behaviour is examined. It is found that improvements in impact toughness as compared with microalloyed medium- carbon ferrite/pearlite steels can be achieved from these predominantly acicular structures developed by controlling alloy composition and continuous cooling of these lower carbon steels. (orig.).
Mixed microstructures have been studied in low- carbon microalloyed steels suitable for automotive applications, after continuous cooling from the hot-rolled condition. Microstructural features such as polygonal ferrite, bainitic and acicular ferrite and microphase constituent are identified using transmission electron microscopy. The influence of these mixed structures on the tensile strength, impact toughness and fracture behaviour is examined. It is found that improvements in impact toughness as compared with microalloyed medium- carbon ferrite/pearlite steels can be achieved from these predominantly acicular structures developed by controlling alloy composition and continuous cooling of these lower carbon steels. (orig.).
...Investigating Biochar: from Source to Sink (Overview - Research) The Sustainable Agriculture Flagship is leading national collaborative research analysing the properties ...and potential of a variety of biochars to improve soil health and sequester carbon. The Sustainable Agriculture Flagship is leading national collaborative research ...analysing the properties and potential of a variety of biochars to improve soil health and sequester carbon. Biochar, sustainable agriculture, soil,...carbon, SAF, pyrolysis, fertiliser, biochar, soil types, greenhouse gas, herbicide, pesticide, bioenergy, soil science, carbon-rich solid, ...
In the framework of the carbon storage two forestry methods are analyzed by the author: the standing capitalization (slowing of the crops) and the spices substitution (slow growing species by fast growing species). The construction of a model taking into account the all stage of the carbon implication (biomass, soil, forest products) offers simulation and quantitative results on these methods. (A.L.B.)
... be easily replaceable, and its compartment or container ... in a simple, efficient manner for storage or disposal. ... and enters the reactor at approximatel ...