OBJECTIVENicotinamide adenine dinucleotides (NAD+ and NADH) play a crucial role in cellular energy metabolism, and a dysregulated NAD+-to-NADH ratio is implicated...Full Text Available
Nitrate reductase from wheat (Triticum aestivum L. cv Bindawarra) leaves is inactivated by pretreatment with NADH, in the absence of nitrate, a 50% loss of activity occurring in 30...Full Text Available
The effects of bivalent cations on cytochrome b5 reduction by NADH:cytochrome b5 reductase and NADPH:cytochrome c reductase were studied with the proteinase-solubilized enzymes. Cytochrome b5 reduction...Full Text Available
AtCBR, a cDNA encoding NADH-cytochrome (Cyt) b5 reductase, and AtB5-A and AtB5-B, two cDNAs encoding Cyt b5, were isolated from Arabidopsis....Full Text Available
NADPH nitrate reductase activity in higher plants has been attributed to the presence of NAD(P)H bispecific nitrate reductases and to the presence of phosphatases capable of hydrolyzing NADPH to NADH....Full Text Available
Two nitrate reductase (NR) mutants were selected for low nitrate reductase (LNR) activity by in vivo NR microassays of M2 seedlings derived from nitrosomethylurea-mutagenized...Full Text Available
Complex I (NADH:ubiquinone oxidoreductase) is the largest enzyme of the mitochondrial respiratory chain. Compared to its bacterial counterpart which encompasses 14-17 subunits, mitochondrial complex I has almost tripled its subunit composition during evolution of eukaryotes, by recruitment of so-called accessory subunits, part of them being specific to distinct evolutionary lineages. The increasing availability of numerous broadly sampled eukaryotic genomes now enables the reconstruction of the evolutionary history of this large protein complex. Here, a combination of profile-based sequence comparisons and basic structural properties analyses at the protein level enabled to pinpoint homology relationships between complex I subunits from fungi, mammals or green plants, previously identified...
We investigated nutrient limitations during hydrocarbon degradation in a sandy soil and found that fixed nitrogen was initially a limiting nutrient but that N limitation could sometimes be overcome...Full Text Available
2-methylpropan-1-ol (isobutanol) is a leading candidate biofuel for the replacement or supplementation of current fossil fuels. Recent work has demonstrated glucose to isobutanol conversion through a modified amino acid pathway in a recombinant organism. Although anaerobic conditions are required for an economically competitive process, only aerobic isobutanol production has been feasible due to an imbalance in cofactor utilization. Two of the pathway enzymes, ketol-acid reductoisomerase and alcohol dehydrogenase, require nicotinamide dinucleotide phosphate (NADPH); glycolysis, however, produces only nicotinamide dinucleotide (NADH). Here, we compare two solutions to this imbalance problem: (1) over-expression of pyridine nucleotide transhydrogenase PntAB and (2) construction of an NADH-de...
This report highlights four main points. (1) A residue substitution in phosphoribulokinase of Synechocystis PCC 6803 renders the mutant light-sensitive. The authors isolated a light-sensitive mutant (BRLS) of the photosynthetic cyanobacterium Synechocystis 6803 that does not survive exposure to bright light; 70% of BRLS cells die upon exposure to light of > 3000 lux for 2 hr. (2) Excitation energy transfer from phycocyanin to chlorophyll in an apcA-defective mutant of Synechocystis sp. PCC 6803. A greenish mutant of the normally bule-green cyanobacterium Synechocystis sp. PC 6803, designated UV6p, was isolated and characterized. UV6p possesses functional photosystems I and II but lacks normal light harvesting phycobilisomes because allophycocyanin is absent and core-specific linker proteins are almost entirely absent. (3) Deletion of the psbG1 gene of the cyanobacterium Synechocystis sp. PCC 6803 leads to the activation of the cryptic psbG2 gene. The genes psbG1 and psbG2 in ...
BackgroundIn a world limited by data availability and limited funds for conservation, scientists and practitioners must use indicator groups to define spatial conservation priorities....Full Text Available
This paper describes a maintenance problem in a fusion power plant. The problem is to specify which life limited parts should be replaced when there is an opportunity. The objective is to minimize the cost rate of replacement parts and of maintenance actions while satisfying a power plant availability constraint. The maintenance policy is to look ahead and replace all parts that will reach their life limits within a time called a screen. Longer screens yield greater system availabilities because more parts are replaced prior to their life limits.
Background: Differentiation between reactive, but morphologically atypical, mesothelial cells and adenocarcinoma in effusions can be problematic. Elaborate immunohistochemical...Full Text Available
G-protein-coupled receptor signalling has been suggested to be voltage dependent in a number of cell types; however, the limits of sensitivity of this potentially important phenomenon are unknown. Using...Full Text Available
The authors’ objective was to analyze the impact of respiratory impairment on the risk of physical functional limitations among adults with chronic obstructive pulmonary disease (COPD)....Full Text Available
Nutrient transport affinities of nutrient-starved microbial populations were measured as initial slopes of plots of limiting-nutrient transport rates versus extracellular limiting-nutrient concentrations....Full Text Available
BackgroundThe bacterial genus Listeria contains pathogenic and non-pathogenic species, including the pathogens L. monocytogenes and L. ivanovii,...Full Text Available
BackgroundObtaining single parasite clones is required for many techniques in malaria research. Cloning by limiting dilution using microscopy-based assessment for parasite growth...Full Text Available
SummationRadioimmunotherapy (RIT) has emerged as one of the most promising treatment options, particularly for hematologic malignancies. However, this approach has generally been limited...Full Text Available
Statistical fluctuations limit the precision with which a microorganism can, in a given time T, determine the concentration of a chemoattractant in the surrounding medium. The best a cell can do is...Full Text Available
• Background and Aims The occurrence of stomata in seed coats is uncommon and there is limited information about their function(s). The aim of this study was to verify the distribution...Full Text Available
Background and objectives: Despite potential significance of fatigue and its underlying components in the occurrence of cardiovascular diseases, epidemiologic data showing the link are virtually limited....Full Text Available
Due to the use of a limited number of species and subchronic exposures, current ecological hazard assessment processes can underestimate the chronic toxicity of environmental contaminants resulting...Full Text Available
BackgroundHearing loss is a common sensory disorder, yet prospective data on potentially modifiable risk factors are limited. Regularly used analgesics, the most...Full Text Available
A study was made of the uncoupling action of polychlorinated biphenyls (Kanechlor-400) on oxidative phosphorylation in rat liver mitochondria. Kanechlor-400 (KC-400) at 20 ..mu..g/ml stimulated state 4 respiration of rat liver mitochondria more than 4-fold with ..cap alpha..-ketoglutarate/malate as a substrate, and released the oligomycin-inhibited state 3 respiration. KC-400 also dissipated the membrane potential across the mitochondrial membranes; thus, it acts as an uncoupler of oxidative phosphorylation in rat liver mitochondria. KC-400 altered the permeability properties of mitochondrial membranes as evidenced by the release of endogenous K/sup +/ and the oxidation of exogenously supplied NADH. It is concluded that KC-400 produces a nonspecific increase in mitochondrial ion permeability, thereby dissipating membrane potential, which leads to the uncoupling.
The present study was designed with an aim to analyze the effect of acute aluminium phosphide (ALP) exposure (10mg/kg b.wt, intragastrically) on the kinetic characteristics of cytochrome oxidase and energy metabolism in male Wistar rat liver mitochondria. Liver mitochondrial preparations from ALP-treated rats exhibited significant decrease (66%) in the activity of cytochrome oxidase suggesting that there was a decrease in the catalytic efficiency of the active oxidase molecules on ALP treatment. The decreased activity of cytochrome oxidase with altered NADH and succinic dehydrogenase activities might have contributed towards a significant decline in state 3 and state 4 respiration as observed. These alterations in the electron transport chain complexes in turn adversely affected the ATP sy...
The document reports the results of a cost-effectiveness analysis of alternative water pollution control regulations of the battery manufacturing industry. These regulations include effluent limitations and standards based on best practical control technology currently available, best available technology economically achievable, and pretreatment standards for new sources. For each of these regulations, EPA has identified several pollution control options, each with different levels of pollution abatement and compliance cost. The analysis is a tool for evaluating the options.
This paper addresses known limitations and constraints in eddy current nondestructive testing. Incomplete appreciation for eddy current limitations is believed to have contributed to both under-utilization and misapplication of the technique. Neither situation need arise if known limitations are recognized. Some, such as the skin depth effect, are inherent to electromagnetic test methods and define the role of eddy current testing. Others can be overcome with available technology such as surface probes to find circumferential cracks in tubes and magnetic saturation of ferromagnetic alloys to eliminate permeability effects. The variables responsible for limitations in eddy current testing are discussed and where alternative approaches exist, these are presented. Areas with potential for further research and development are also identified.
ObjectiveLimited data is available to understand the prevalence and correlates of suicidal behavior among U.S. Latino subgroups. This paper compares the prevalence...Full Text Available
Acetaminophen (APAP) toxicity is the most common drug-induced cause of acute liver failure in the United States. The only available treatment, N-acetylcysteine (NAC), has a limited...Full Text Available
Outpatient practice after percutaneous coronary intervention (PCI) is gaining momentum due to constantly optimizing results. Furthermore, the availability of limited beds to handle the large volume...Full Text Available
Autofluorescence spectroscopy has been a widely explored technique for in vivo and noninvasive diagnosis of pre-cancer lesions in epithelium where 90% cancers originate. For extracting more accurate fluorescence information for cancer diagnosis, depth-resolved fluorescence measurements are crucial to assess NADH and FAD in non-keratinized epithelial layer and collagen in stromal layer, respectively. In this study, we achieved the depth-resolved fluorescence spectral measurements of squamous epithelial tissue based on confocal technique. We found that in non-keratinized epithelial layer the fluorescence signals excited at 405 nm were the combination of NADH and FAD fluorescence and could be used for evaluating the redox ratio. Moreover, we found that confocal time-resolved autofluorescence measurements of epithelial tissue with 405 nm excitations could provide the information on the layered tissue structure. All depth-resolved autofluorescence ...
Technical Development Document supporting proposed water discharge regulations for the Coal Mining Industry authorized by the Clean Water Act. Proposed regulations include revised best practicable technology limitations, best available technology limitations and new source performance standards for the Coal Mining Industry. Industry operations include: coal preparation and amillary operations, active mining, F bituminous, anthracite and lignite coal, and the reclamation phase of mining.
The document describes the statistical analyses of data on pollutant loadings in effluent wastestreams from pulp, paper, and paperboard facilities. Included are the analyses that support the revised subcategorization and proposed effluent limitations for biochemical oxygen demand and total suspended solids based upon the best practicable control technology currently available.
This document provides a technical basis for the revision of chemical effluent limitations guidelines for the Steam Electric Power Industry reflecting the Best Available Technology Economically Achievable (BATEA) for existing sources, New Source Performance Standards (NSPS) and Pretreatment Standards. The analysis of pollutants and the technologies applicable to their control has been based on specific waste streams of concern.
ObjectivesThe practical exploitation of tidal stream energy is limited by man's activities in coastal waters: navigation, fishing and~%~leisure pursuits. It is important therefore to make the best use of the sites, which are available. The main objective of the~%~Proposed study is to assess the limits imposed by waves on the performance of tidal stream rotors, and to investigate way:~%~in which these limits might be related by refinements in rotor design and the control of operating conditions. Secondary~ [continued...]DescriptionHorizontal aids wind turbines have been recognised as one of the most successful renewable energy saving devices. The use of the similar concept as a 'tidy stream rotor' in offshore environment appears to be even more compelling. However, the application of this concept will require the confirmation of various operational and environmental limitations due ...
The side effects of cancer therapy on normal tissues limit the success of therapy. Generation of reactive oxygen species (ROS) has been implicated for numerous chemotherapeutic agents including doxorubicin...Full Text Available
The rapid global loss of natural habitats and biodiversity, and limited resources, place a premium on maximizing the expected benefits of conservation actions. The scarcity of information on the fine-grained...Full Text Available
BackgroundMicroarray studies can supplement QTL studies by suggesting potential candidate genes in the QTL regions, which by themselves are too large to provide a limited selection...Full Text Available
Depleted uranium (DU) is a dense heavy metal used primarily in military applications. Although the health effects of occupational uranium exposure are well known, limited data exist regarding the long-term...Full Text Available
Recent research has implicated the nucleus accumbens (NAc) in consolidating recently acquired goal-directed appetitive memories, including spatial learning and other instrumental processes. However,...Full Text Available
1. At high running speeds, the step frequency becomes lower than the apparent natural frequency of the body's bouncing system. This is due to a relative increase of the vertical component of the muscular...Full Text Available
OBJECTIVE--To assess the accuracy of the ten questions screen as a measure of childhood disability for epidemiologic studies in populations lacking resources for professional assessment of children's...Full Text Available
Most of the general population is exposed to carbaryl and other contemporary-use insecticides at low levels. Studies of laboratory animals, in addition to limited human data, show an association between...Full Text Available
Damaging inflammation arising from autoimmune pathology and septic responses results in severe cases of disease. In both instances, anti-inflammatory compounds are used to limit the excessive...Full Text Available
Objectives. We assessed the effectiveness of various systems of community participation in ethical review of environmental health research.Methods. We used situation...Full Text Available
BackgroundClinical experience with the continuous glucose monitoring systems (CGMS) is limited in Korea. The objective of this study is to evaluate the accuracy of the CGMS and the...Full Text Available
BackgroundCharacterizing infectious disease burden in Africa is important for prioritizing and targeting limited resources for curative and preventive services and monitoring the...Full Text Available
The development of new methods for gene addition to mammalian genomes is necessary to overcome the limitations of conventional genetic engineering strategies. Although a variety of DNA-modifying enzymes...Full Text Available
Microbes in nature frequently function as members of complex multitaxon communities, but the structural organization of these communities at the micrometer level is poorly understood because of limitations...Full Text Available
In many dinoflagellate species, the plastid genome has been proposed to exist as a limited number of single-gene minicircles, and many genes normally found in the plastid genome are nuclear-encoded....Full Text Available
Background:Encouragement of stroke patients to resume driving is important to promote their reintegration into the community. Limited rehabilitation has been performed in this regard,...Full Text Available
This paper discusses the fundamentals, applications, potential, limitations, and future perspectives of polarized light reflection techniques for the characterization of materials and related systems...Full Text Available
BackgroundCurrently used indicators of iron status have limitations. Hepcidin, a key regulator of iron metabolism, is reduced in iron deficiency. We sought to determine the properties...Full Text Available
The rate-limiting step in the transit of dietary fat across the intestinal absorptive cell is its exit from the endoplasmic reticulum (ER) in a specialized ER-to-Golgi transport vesicle, the prechylomicron...Full Text Available
Angiosarcoma (AS) is a rare and aggressive vascular neoplasm with very poor prognosis. Patients with extensive cutaneous AS who are not surgical candidates have very limited options since there is no...Full Text Available
Sixty-seven patients hospitalized for poisonous snakebite between 1975 and 1990 were managed by elevation, tetanus prophylaxis, intravenous fluids and antibiotics, and often by a limited excision of...Full Text Available
Previous studies with a limited number of strains have indicated that there are two genotypes of yellow fever (YF) virus in Africa, one in west Africa and the other in east and central Africa. We have...Full Text Available
Successful implementation of bone marrow transplantation for hematopoietic reconstitution is limited by the lack of suitably HLA-matched donors and by the occurrence of graft-versus-host disease that...Full Text Available
The pharmacokinetics of oral fluoroquinolone antibiotics in normal volunteers have been studied extensively; however, limited patient data exist. Enoxacin steady-state pharmacokinetics and bioavailability...Full Text Available
Paediatric palliative care is a holistic approach aimed at addressing the complex issues related to the care of children and families facing chronic life limiting illnesses. The needs of children are...Full Text Available
BackgroundThe expression of human virus surface proteins, as well as other mammalian glycoproteins, is much more efficient in cells of higher eukaryotes rather than yeasts. The limitations...Full Text Available
Development of mouse models representing human spontaneous ovarian cancer has been hampered by the lack of understanding of the etiology of this very complex disease. Mouse models representing the different...Full Text Available
The use of percutaneous transluminal coronary angioplasty is limited by procedural complications and the serious drawback of restenosis, but some new techniques have been developed in an attempt to...Full Text Available
Ovarian carcinoma is now the leading cause of death among women. Surgery has reached its limits, and further aggressive surgery will result in an inordinate morbidity and mortality. Ovarian carcinoma...Full Text Available
Wild-type viruses from the ViroLogic phenotype-genotype database were evaluated to determine the upper confidence limit of the drug susceptibility distributions, or “biological cutoffs,”...Full Text Available
We showed recently that secretion of glutamate in biotin-limited cells of Corynebacterium glutamicum is mediated by carrier systems in the plasma membrane (C. Hoischen and R. Krämer, Arch. Microbiol....Full Text Available
The exact incidence of pineal germ-cell tumors is largely unknown. The tumors are rare, and the number of patients with these tumors, as reported in clinical series, has been limited. The goal of this...Full Text Available
Major breakthroughs have recently been reported that can help overcome two inherent drawbacks of NMR: the lack of sensitivity and the limited memory of longitudinal magnetization. Dynamic nuclear polarization...Full Text Available
BackgroundThe widespread use of nutritional supplements among athletes is poorly understood. The prevalence of supplement intake and users' knowledge have been researched independently...Full Text Available
BackgroundIn primary hyperparathyroidism (PHPT) the predictive value of technetium 99m sestamibi single emission computed tomography (Tc99m-MIBI-SPECT) for localizing pathological...Full Text Available
BackgroundRecent research highlights the promise of remotely sensed aerosol optical depth (AOD) as a proxy for ground-level particulate matter with aerodynamic diameter ≤...Full Text Available
Finding pertinent information is not limited to search engines. Online communities can amplify the influence of a small number of power users for the benefit of all other users. Users' information foraging...Full Text Available
BackgroundIntegration of medical care across clinicians and settings could enhance the quality of care for patients. To date, there is limited data on the levels of integration in...Full Text Available
Endogenous circadian clocks are robust regulators of physiology and behavior. Synchronization or entrainment of biological clocks to environmental time is adaptive and important for physiological homeostasis...Full Text Available
Peptic ulcer bleeding is a common disease and recurrent bleeding is an independent risk factor of mortality. Infusion with proton pump inhibitors (PPIs) prevents recurrent bleeding after successful...Full Text Available
Infection due to multidrug resistance pathogens is difficult to manage due to bacterial virulence factors and because of a relatively limited choice of antimicrobial agents. Thus, it is imperative to...Full Text Available
Intensity modulated radiotherapy (IMRT) is widely used in clinical applications in developed countries, for the treatment of malignant and non-malignant diseases. This technique uses multiple radiation...Full Text Available
The effectiveness of chemotherapy in human schistosomiasis varies from one area to another, and limited data from experimentally infected animals suggest inherent differences in the susceptibility...Full Text Available
Mouse models have dramatically improved our understanding of cancer development and tumor biology. However, these models have shown limited efficacy as tractable systems for unbiased genetic...Full Text Available
The virtual lack of well-characterized metastatic pancreatic cancer tissues for study has limited systematic studies of the metastatic process of this deadly disease. To address this important...Full Text Available
Noise pollution from human traffic networks and industrial activity impacts vast areas of our planet. While anthropogenic noise effects on animal communication are well documented, we have very limited...Full Text Available
BACKGROUND: Although the importance of lymphatic function is well recognized, the lack of real-time imaging modalities limits our understanding of its role in many diseases. In a phase...Full Text Available
Physical activity and sedentary behavior are central components of lifetime weight control; however, our understanding of dimensions of these behaviors in childhood is limited. This study investigated...Full Text Available
The computational fluid dynamics methods for the limited flow rate and the small dimensions of an intracranial artery stenosis may help demonstrate the stroke mechanism in intracranial atherosclerosis....Full Text Available
BackgroundExpansion of aquaculture is seriously limited by reductions in fish oil (FO) supply for aquafeeds. Terrestrial alternatives such as vegetable oils (VO) have been investigated...Full Text Available
Recently, there has been significant progress in the development of genetically-engineered mouse (GEM) models. By introducing genetic alterations and/or signaling alterations of human pancreatic cancer...Full Text Available
Tendon reconstruction using grafts often results in adhesions that limit joint flexion. These adhesions are precipitated by inflammation, fibrosis, and paucity of tendon differentiation signals...Full Text Available
Parasitic nematodes cause serious diseases in humans, animals, and plants. They have limited lipid metabolism and are reliant on lipid-binding proteins to acquire these metabolites from their hosts....Full Text Available
ContextFatigue is the most common sequela among non-small cell lung cancer (NSCLC) survivors 1–6 years post-treatment and is associated with functional limitations.Full Text Available
BackgroundCyclooxygenase (cox) is the rate-limiting enzyme, which catalyzes the conversion of arachidonic acid into prostaglandins and contributes to the inflammatory process. Cyclooxygenase-2...Full Text Available
BackgroundHerbs and other dietary supplements are among the most commonly used complementary medical therapies. However, clinicians generally have limited knowledge, confidence and...Full Text Available
The incidence of melanoma is increasing more than any other cancer, and knowledge of its genetic alterations is limited. To systematically analyze such alterations, we performed whole-exome...Full Text Available
Alternatives for developing chronic exposure limits for noncancer effects of trichloroethylene (TCE) were evaluated. These alternatives were organized within a framework for dose-response assessment--exposure:dosimetry...Full Text Available
A quantum computer (QC) can operate in parallel on all its possible inputs at once, but the amount of information that can be extracted from the result is limited by the phenomenon of wave function...Full Text Available
Doxorubicin (DOX) is widely used in combination cocktails for treatment of childhood hematological cancers and solid tumors. A major factor limiting DOX usage is DOX-induced cardiotoxicity. However,...Full Text Available
By using EPR measurements of radiation-induced radicals it is possible to utilize human fingernails to estimate radiation dose after-the-fact. One of the potentially limiting factors in this...Full Text Available
Energetically costly behaviours, such as flight, push physiological systems to their limits requiring metabolic rates (MR) that are highly elevated above the resting MR (RMR). Both RMR and MR during...Full Text Available
The hepatic uptake rate for certain albumin-bound drugs and metabolites correlates poorly with their equilibrium unbound concentration in the plasma, suggesting that binding equilibrium may not always...Full Text Available
The recovery of schistosome cercariae from natural waters has been limited by variations in turbidity and in the accuracy of recovery with different techniques. A modification of the Rowan vacuum paper...Full Text Available
The prevalent surge in childhood and adolescent obesity within the past 3 decades poses a significant challenge for many pediatric clinicians who are charged with treating this condition. The...Full Text Available
BackgroundTrypanosomosis is a major impediment to livestock farming in sub-Saharan Africa and limits the full potential of agricultural development in the 36 countries where it is...Full Text Available
Improved NMR detection of mass limited samples can be obtained by taking advantage of the mass sensitivity of microcoil NMR, while throughput issues can be addressed using multiple, parallel...Full Text Available
Recently reported technologies for DNA-directed organic synthesis and for DNA computing rely on routing DNA populations through complex networks. The reduction of these ideas to practice has been limited...Full Text Available
The dental pulp consists of loose connective tissue encased in rigid dentinal walls. Because of its topography the tissue has low interstitial compliance and limited capacity to expand during fluid...Full Text Available
Background & objectives: Fatigue is a debilitating symptom experienced by patients undergoing dialysis, but there is only limited information on its prevalence and its association with patient...Full Text Available
Clinical applications of genetic therapies, including delivery of short, interfering RNAs (siRNAs) for RNA interference (RNAi), are limited due to the difficulty of delivering nucleic acids...Full Text Available
There is limited information about the true incidence of acute renal failure (ARF). Most studies could not quantify disease frequency in the general population as they are hospital-based and...Full Text Available
A closed loop control process assures that a system performs within control limits. In closed loop control, the system's output feeds back directly to change the system's inputs. We describe an approach...Full Text Available
BackgroundUntil now only limited research has been done on the prevalence of chronic pain in primary care. The aim of this investigation was to study the health care utilisation...Full Text Available
Investigations of psychrotrophic microorganisms have been limited even though the dominant environment of the Earth is cold and enzymes with high activities at low temperatures could have commercial...Full Text Available
Hookworms, bloodfeeding intestinal nematodes, infect nearly one billion people in resource limited countries and are a leading cause of anemia and malnutrition. Like other nematodes, hookworms...Full Text Available
Zinc modulates the activity of glutamic acid decarboxylase, the rate limiting enzyme in the synthesis of gamma-aminobutyric acid (GABA), which is a major inhibitory neurotransmitter. Low cerebrospinal...Full Text Available
Many plants are known to reduce the toxic effects of high soil boron (B) by reducing uptake of B, but no mechanism for limiting uptake has previously been identified. The B-tolerant cultivar of barley...Full Text Available
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
Scoping studies have been used across a range of disciplines for a wide variety of purposes. However, their value is increasingly limited by a lack of definition and clarity of purpose. The UK's Service...Full Text Available
BackgroundThe Gram-negative, xylem-limited phytopathogenic bacterium Xylella fastidiosa is responsible for causing economically important diseases in grapevine,...Full Text Available
ObjectiveThere has been much debate about the value of condoms in HIV/STI programming. This should be informed by evidence about intervention impact on condom use, but there is limited...Full Text Available
BackgroundWith rates of childhood obesity increasing, physical activity (PA) promotion especially in young children has assumed greater importance. Given the limited effectiveness...Full Text Available
Transthyretin aggregation-associated proteotoxicity appears to cause several human amyloid diseases. Rate-limiting tetramer dissociation and monomer misfolding of transthyretin (TTR) occur before...Full Text Available
Predation is generally thought to constrain sexual selection by female choice and limit the evolution of conspicuous sexual signals. Under high predation risk, females usually become less choosy, because...Full Text Available
Background and AimsSecondary growth via successive cambia has been intriguing researchers for decades. Insight into the mechanism of growth layer formation is, however, limited to...Full Text Available
Environmental exposure measurements are, in general, positive and may be subject to left censoring; i.e,. the measured value is less than a ''detection limit''. In occupational monitoring, strategies for assessing workplace exposures typically focus on the mean exposure level or the probability that any measurement exceeds a limit. Parametric methods used to determine acceptable levels of exposure, are often based on a two parameter lognormal distribution. The mean exposure level, an upper percentile, and the exceedance fraction are used to characterize exposure levels, and confidence limits are used to describe the uncertainty in these estimates. Statistical methods for random samples (without non-detects) from the lognormal distribution are well known for each of these situations. In this report, methods for estimating these quantities based on the maximum likelihood method for randomly ...
The purpose was to study the toxicity of drugs known to generate free radicals on isolated pancreatic islets. The accumulattion of "8"6Rb"+ by mouse pancreatic islets was measured in vitro. Exposing the islets to 6-hydroxydopamine, minhydrin, or phenazine methosulphate + NADH inhibited the Rb"+ uptake, whereas paraquat or acetylphenylhydrazine had no effect. This effect of 6-hydroxydopamine was prevented by either of the hydroxyl radical scavengers, sodium benzoate and mannitol, but not by the non-scavenger,urea; ninhydrin was partially protected against by mannitol but not by benzoate. Protection against 6-hydroxydopamine was also afforded by D-glucose but not by L-glucose or 3-O-methyl-D-glucose; none of the sugars protected against ninhydrin. In damaging islet beta-cells and in being protected against by D-glucose, 6-hydroxydopamine closely resembles the diabetogenic drug, alloxan. It is suggested that protection against alloxan may involve both glucose ...
A new characteristics temperature, an adiabatic limit flame temperature, was proposed as the basis to evaluate an effective energy emission and to examine a self combustion limit. Its characteristics were discussed using the reaction system between diatomic molecules as an example, and the low calorific limit of flammability was also discussed. Since the adiabatic limit flame temperature was the inherent temperature of a combustible mixture based on the thermochemical properties of constituents, it was, in particular, very important as considering a combustion system with energy recirculation between products and reactants. The available energy and efficiency of the combustion system should have been estimated on the basis of this temperature, instead of on an adiabatic flame temperature. It was also considerably high even in an extremely lean mixing ratio, however, the flame ...
Several enzymes of the metabolic pathways responsible for metabolism of cytosolic ribonucleotides and deoxyribonucleotides are located in mitochondria. Studies described in this paper suggest dysfunction of the mitochondria to affect these metabolic pathways and limit the available levels of cytosolic ribonucleotides and deoxyribonucleotides, which in turn can result in aberrant RNA and DNA synthesis. Mitochondrial dysfunction has been linked to genomic instability, and it is possible that the limiting effect of mitochondrial dysfunction on the levels of nucleotides and resulting aberrant RNA and DNA synthesis in part can be responsible for this link. This paper summarizes the parts of the metabolic pathways responsible for nucleotide metabolism that can be affected by mitochondrial dysfunction.
Power output of a hydrogen-diesel dual-fuel engine is limited by the onset of knock as the percentage of heat input derived from hydrogen increased beyond a certain limit. Earlier work carried out at the Internal Combustion Engines Laboratory, Indian Institute of Technology, Madras, indicates that this knock sets in when the induced hydrogen exceeds about 60% of input energy at a pilot diesel quantity of 30% of full load diesel amount. At higher rates of hydrogen induction, the richer hydrogen-air mixture is more prone to knocking. Hardly any information is available on the possibilities of improving the knock limited power output of a hydrogen-diesel dual-fuel engine. Water can serve as a powerful internal coolant in decreasing the unburned mixture temperature because of its high latent heat. This paper presents the results of our investigation on improving the knock limited power ...
Objectives~%~~%~The practical exploitation of tidal stream energy is limited by man's activities in coastal waters: navigation, fishing and~%~leisure pursuits. It is important therefore to make the best use of the sites, which are available. The main objective of the~%~Proposed study is to assess the limits imposed by waves on the performance of tidal stream rotors, and to investigate way:~%~in which these limits might be related by refinements in rotor design and the control of openiting conditions. S~%~ [continued...]DescriptionHorizontal aids wind turbines have been recognised as one of the most successful renewable energy saving devices. The use of the similar concept as a 'tidy~%~~%~stream rotor' in offshore environment appears to be even more compelling. However, the application of this concept will require the confirmation of various operational and ...
Current medical visualization technology intended for positional guidance in surgical applications may only ever have limited utility in the operating room due to the preexisting visual requirements of surgical practice. Additionally, visual systems impose limits as a result of their high latency, poor image resolution, problems with stereopsis and physical strain upon the user. Audio technology is relatively unexamined in the broad range of available methodologies for medical devices. The potential to translate surgical instrument position into audio feedback presents a novel solution to the human factors and engineering problems faced by visual display technology because audio technology employs a rich and as yet unburdened sensory modality. We describe an experimental system we have developed for investigating this new interface design approach using commercially available hardware. PMID:10173065
The report identifies and analyzes the economic impacts of water pollution control regulations on the battery manufacturing industry. These regulations include effluent limitations and standards based on BPT (best practical control technology currently available), BAT (best available technology economically achievable), PSES (pretreatment standards existing sources), NSPS (new source performance standards), and PSNS (pretreatment standards new sources), that have been promulgated under authority of Sections 301, 304, 306, 307, 308, and 501 of the Federal Water Pollution Control Act, as Amended (the Clean Water Act). The primary economic impact variables of interest include price changes, plant closures, substitution effects, changes in employment, shifts in the balance of foreign trade, changes in industry profitability, structure, and competition, and impacts on small business.
The management of CNS tumors is limited by the blood-brain barrier (BBB), a vascular interface that restricts the passage of most molecules from the blood into the brain. Here we show that phage particles...Full Text Available
Stearoyl-coenzyme A desaturase (SCD) is the rate-limiting enzyme necessary for the biosynthesis of monounsaturated fatty acids. In this study, we investigated the regulation of mouse SCD1 by liver X...Full Text Available
The philosophy of containing tritium and activated products very close to the source and of operating by remote techniques is justified by a comparison with other concepts on protection and availability points of view. Several design options are studied according to the optimization protection methodology of ICRP. Provided that an important technological development is accomplished, the utilization of robotics and the limitation of containment volumes should be generalized.
Addresses factors affecting rural education in Tasmania (Australia), including population trends, financial support, student enrollment, socioeconomic status of rural residents, and geographic isolation. Issues that need to be addressed include the status of small schools in Tasmania, costs associated with transporting students, staffing, low student retention, and limitedavailability of special services. (LP)
We used fast absorbance spectroscopy to investigate in vivo binding dynamics and electron transfer between plastocyanin (pc) and photosystem I (PSI), and cytochrome (cyt) f...Full Text Available
BackgroundThe purpose of this study was to analyze the radiotherapy (RT) quality assurance (QA) assessment in Japan Clinical Oncology Group (JCOG) 0202, which was the first trial...Full Text Available
The use of tick vaccines in mammalian hosts has been shown to be the most promising alternative tick control method to current use of acaricides, which suffers from a number of limitations. However,...Full Text Available
The Commission of the European Communities has submitted a directive for the protection against microwaves. According to this directive, exposures above the upper limit established for the protection of individuals and the general population are permissible only if the respective individuals are required to submit to occupational medical control. An introductory overview is presented giving information on microwaves, applied techniques and available protective means.
The NSABP B-32 trial is examining whether patients with initially negative sentinel lymph nodes (SLNs) who have occult metastases detected on deeper levels and cytokeratin immunohistochemistry...Full Text Available
This study evaluates the frequency and functions of immunocompetent T cells at the clonal level in solid human lung tissue versus peripheral blood. Enzymatic digestion of slices of histologically normal...Full Text Available
BackgroundWe investigated whether p42/p44 extracellular signal-regulated kinases (ERK1/2) and/or phosphatidylinositol-3-OH kinase (PI3K)-Akt play a crucial role in cardioprotection...Full Text Available
This report describes a high explosives test facility that makes efficient use of equipment and combines utility, convenience, and safety in a modest amount of space. It is a dedicated facility for exploratory development efforts that previously were conducted in a single room having very limited capabilities. Two explosives testing areas are now available and several projects are supported concurrently.
BackgroundStudies of chronic health effects due to exposures to particulate matter with aerodynamic diameters ≤ 2.5 μm (PM2.5) are often limited by sparse...Full Text Available
To determine if the enhanced glycemic response to epinephrine in patients with insulin-dependent diabetes mellitus (IDDM) is the result of increased adrenergic sensitivity per se, increased glucagon...Full Text Available
BackgroundLimited information has been published regarding how specific processes for event adjudication can affect event rates in trials. We reviewed nonfatal myocardial infarctions...Full Text Available
The CNS is a unique organ due to its limited capacity for immune surveillance. As macrophages of the CNS, microglia represent a population originally known for the ability to assist neuronal stability,...Full Text Available
Clostridium thermoaceticum ATCC 39073 converted vanillate to catechol. Although carboxylated aromatic compounds which did not contain methoxyl groups were not by themselves growth supportive, protocatechuate...Full Text Available
Proceeding from commercially available instruments, a simple measuring system has been established, which renders possible fast and simple discontinuous analysis of individual elements. This measuring system is described, giving some examples of utilization in nonferrous metallurgy (mining, ore dressing, metallurgical treatment), and specific details, such as error of measurement, ranges of measurement and limits of utilization. (author).
A novel CFD/structural analysis was performed to predict functionality of a cross parachute under loadings near the structural limits of the parachute. The determination of parachute functionality was based on the computed structural integrity of the canopy and suspension lines. In addition to the standard aerodynamic pressure loading on the canopy, the structural analysis considered the reduction in fabric strength due to the computed aerodynamic heating. The intent was to illustrate the feasibility of such an analysis with the commercially available software PATRAN.
Summary: SHAP (simple high-throughput annotation pipeline) is a lightweight and scalable sequence annotation pipeline capable of supporting research efforts that generate or utilize large volumes of DNA sequence data. The software provides Grid capable analysis, relational storage and Web-based full-text searching of annotation results. Implemented in Java, SHAP recognizes the limited resources of many smaller research groups. Availability: Source code is freely available under GPLv3 at External Link Not Shown. Contact: matt.demaere@unsw.edu.au; r.cavicchioli@unsw.edu.au
Future power plants will be more fuel efficient, environmentally benign, and economical than current power plants. A high performance power system (HIPPS), based on a coal-fired combined cycle, is currently being developed. The corrosion and temperature-strength properties of currently available metallic materials limit the maximum efficiency of this cycle. Recently, ceramic matrix composites have shown promise in overcoming the design limitations on the future power plants. In particular, the high-temperature, and corrosion and erosion resistant properties of continuous fiber ceramic composites (CFCCs) will allow engineers to design high-temperature heat exchangers, cyclone vortex finder tubes, and other components. Research being performed to evaluate candidate materials for use in future power plants is discussed.
Survival and growth of terrestrial plants is negatively affected by complete submergence. This is mainly the result of hampered gas exchange between plants and their environment, since gas diffusion is severely reduced in water compared with air, resulting in O2 deficits which limit aerobic respiration. The continuation of photosynthesis could probably alleviate submergence-stress in terrestrial plants, but its potential under water will be limited as the availability of CO2 is hampered. Several submerged terrestrial plant species, however, express plastic responses of the shoot which may reduce gas diffusion resistance and enhance benefits from underwater photosynthesis. In particular, the plasticity of the flooding-tolerant terrestrial species Rumex palustris turned out to be remarkable,...
Under 10CFR50 Appendix B, utilities have a commitment to establish and maintain material control programs to assure the safety and reliability of their power plants. The guidelines in this report discuss methods of establishing, maintaining, and extending the shelf life of limited life items. In addition, these guidelines establish justifiable shelf lives for a sample of 70 items and review the effects of environmental conditions. Moreover, the guidelines are consistent with utility qualification test documentation and provide for evaluation of items with expired shelf lives. These guidelines set precedent by indicating that the shelf life is greater than previously available for many items. This increase in shelf life has been established through natural and accelerated aging tests.
Pots used for experiments conducted on plants grown in them create rooting environments that are affected by limited soil volume, which can affect various physiological processes, including transpiration, and plant growth. However, the applicability of results from pot experiments to the field has received limited attention. The objective of this study was to compare the growth and transpiration of maize (Zea mays L.) and winter wheat (Triticum aestivum L.) when grown in pots and field plots under various constant water deficits. The experiments were conducted under similar environmental conditions for both pots and plots. Transpirational responses at both transient (RTTr) and daily (RDTr) time scales to a decreasing fraction of available soil water (FASW) were analyzed. For a comparable F...
The purpose of the study is to analyze the economic impacts that are likely to result from promulgation of the proposed best practicable control technology (BPT), best available technology economically achievable (BAT) and Best Conventional Technology (BCT) effluent limitations and standards on placer mining in the United States. The results of the economic impact analysis will help establish pollution control regulations that are economically achievable. The analysis examines how each of four alternative pollution control technologies affects the financial viability of placer mines in the United States. The impacts examined include reduced profitability, production cutbacks, mine closures, and employment and earning losses, as well as impacts to the local economies.
It has been shown that two-dimensional arrays of rigid or fluidlike cylinders in a fluid or a gas define, in the limit of large wavelengths, a class of acoustic metamaterials whose effective parameters (sound velocity and density) can be tailored up to a certain limit. This work goes a step further by considering arrays of solid cylinders in which the elastic properties of cylinders are taken into account. We have also treated mixtures of two different elastic cylinders. It is shown that both effects broaden the range of acoustic parameters available for designing metamaterials. For example, it is predicted that metamaterials with perfect matching of impedance with air are now possible by using aerogel and rigid cylinders equally distributed in a square lattice. As a potential application of the proposed metamaterial, we present a gradient index lens for airborne sound (i.e. a sonic Wood lens) whose functionality is ...
The effects of purified Helminthosporium maydis T (HmT) toxin on active Ca/sup 2 +/ transport into isolated mitochondria and microsomal vesicles were compared for a susceptible (T) and a resistant (N) strain of corn (Zea mays). ATP, malate, NADH, or succinate could drive /sup 45/Ca/sup 2 +/ transport into mitochondria of corn roots. Ca/sup 2 +/ uptake was dependent on the proton electrochemical gradient generated by the redox substrates or the reversible ATP synthetase, as oligomycin inhibited ATP-driven CA/sup 2 +/ uptake while KCN inhibited transport driven by the redox substrates. Purified native HmT toxin completely inhibited Ca/sup 2 +/ transport into T mitochondria at 5 to 10 nanograms per milliliter while transport into N mitochondria was decreased slightly by 100 nanograms per milliliter toxin. Malate-driven Ca/sup 2 +/ transport in T mitochondria was frequently more inhibited by 5 nanograms per milliliter toxin than succinate or ATP-driven Ca/sup 2 +/ ...
A free standing outdoor telephone booth is provided with a photovoltaic (PV) array, one or more rechargeable storage batteries and electrical control circuit which includes a temperature compensated control for limiting the supply of electrical energy from the PV array to the rechargeable battery to avoid over charging the battery, an ambient light (solar insolation) sensing circuit for controlling the electrical lamp load, to turn the lamp ON during dark ambient and OFF during light ambient conditions. In addition, the total discharge limit of the storage battery is controlled to a safe operating limit and a means is disclosed to power a fluorescent lamp at energy conserving intensities with energy derived from the rechargeable storage battery. The lamp control circuitry is preferably constituted by a high frequency power inverter with regulated output power to energize a low wattage fluorescent lamp and to dim the ...
We re-examine the process of loop quantization for flat isotropic models in cosmology. In particular, we contrast different inequivalent `loop quantizations' of these simple models through their respective successes and limitations and assess whether they can lead to any viable physical description. We propose three simple requirements which any such admissible quantum model should satisfy: i) independence from any auxiliary structure, such as a fiducial interval/cell introduced to define the phase space when integrating over non-compact manifolds; ii) existence of a well defined classical limit and iii) provide a sensible "Planck scale" where quantum gravitational effects become manifest. We show that even when it may seem that one can have several possible loop quantizations, these physical requirements considerably narrow down the consistent choices. Apart for the so called improved dynamics of LQC, none of the other ...
The Darrieus-type Vertical Axis Wind Turbine (VAWT) presents a variety of unusual structural problems to designers. The level of understanding of these structural problems governs, to a large degree, the success or failure of today's rotor designs. A survey is presented of the technology available for rotor structural design with emphasis on the DOE research program now underway. Itemizations are included of the major structural issues unique to the VAWT along with discussion of available analysis techniques for each problem area. It is concluded that tools are available to at least approximately address the most important problems. However, experimental data for confirmation is rather limited in terms of volume and the range of rotor configurations tested.
In neutron radiography, as in other forms of NDE, it is sometimes desirable to observe dynamic events. This need has generated increased interest in the development of real-time neutron radiography systems and neutron-to-light converter screens optimized for real-time application. Two screens currently available at MURR are: (1) a 0.041-cm-thick Gd_2O_2S screen manufactured by 3M Company and (2) a "6KiF-ZnS(Ag) screen (NE 426) manufactured by Nuclear Enterprises. These screens are presently used in conventional film neutron radiography and represent two of the commercially available screens that have demonstrated the greatest resolution and sensitivity. Unfortunately, these screens have severe limitations when used for real-time neutron radiography. In order to isolate and minimize the factors contributing to these limitations, several neutron absorbers and phosphorus were studied at MURR. The screen ...
Pollution abatement measures against impulsive low frequency noises including mine blasting noise require precise measurement of sound waveforms, but no instruments have been designed for that purpose, nor commercially available. This paper describes investigations on such instruments as noise level meters currently available commercially on their instrumental characteristics using indoor experiments and field measurements. The following matters were clarified: An instrument combining a microphone with an amplifier can not determine the response from the measuring system from the respective frequency characteristics alone, and requires a discussion on the overall response from the measuring system. A preferred noise level meter would be an instrument that has the lower limit for the frequency characteristics of the microphone extended to several hertz, and measures noises without passing through a filter to interrupt ...
A vortex diode has been developed as a reverse flow limiter in the primary circuit of an advanced gas cooled reactor. In addition to the development work on a prototype diode to optimise performance and geometry, measurements were also made on an available experimental diode of similar size with pressure differences up to 4 MPa and temperatures up to 600 K using nitrogen, argon and carbon dioxide as the test fluids. Correlation of data from all tests was satisfactorily obtained using isentropic one-dimensional nozzle flow equations. (author).
Electronic circular dichroism (ECD) of the n-#pi# and #pi# -#pi# transitions of the amide groups in the ultraviolet has become an indispensable tool for qualitative characterization of proteins in solution. Since the existence of such a spectrum (that is, of natural optical activity) comes from the three dimensional interaction of the chromophores in the molecule, CD is exquisitely sensitive to molecular conformation. However, in proteins, the amide transitions available in the near UV are limited in number and are broads and overlapping. Interactions among them yield information about the polymeric backbone, but since such amide electronic excitation are relatively delocalized, the resulting
Major factors that contribute to maximized impact resistance of semicrystalline engineering polymers include increased matrix molecular weight, minimal rubber glass-transition temperature, and optimal rubber-particle size, which depends on matrix type. Additional constraints are posed by the limitations of available materials and commercial requirements. Expanding the understanding of impact-modified crystalline engineering polymers will further extend their property ranges and utility. This chapter describes the phenomenology of certain factors, illustrates a new technique to measure rubber particle size, and contrasts the fracture mechanisms of poly(butylene terephthalate), nylon 66, and polyacetal. 49 refs., 24 figs.
Olive tree (Olea european L.) cultivation, the major tree crops in Mediterranean countries is being extended to irrigated lands. However, the limited water availability, the severe climatic conditions and the increased need for good water quality for urban and industrial sector uses are leading to the urgent use of less water qualities (brackish water and recycled wastewater) for olive tree irrigation. The aim of this work was to asses the effects of long term irrigation with treated waste water (TWW) on the soil chemical properties, on olive tree growth and on oil quality characteristics. (Author)
A modelling approach is presented that appears to have the potential to provide reliable assessments of pollution concentration in coastal zones and complex terrain, where the assumptions behind current operational air quality models often are inadequate. With the use of a numerical mesoscale model (NMM), physically consistent flow fields can be predicted, thereby providing higher spatial and temporal resolution in the meteorological fields than would be available from a limited number of observation points. These predictions are used to calculate mean trajectories of pollutant parcels, as well as to provide quantitative estimates of pollution concentration using two techniques.
Both the nature of international climate policy architectures and the development and diffusion of new energy technologies could dramatically influence future costs of reducing global emissions of greenhouse gases. This paper explores the implications of interactions between technology availability and performance and international policy architectures for technology choice and the social cost of limiting atmospheric CO2 concentrations to 500 ppm by the year 2095. Key issues explored in the paper include the role of bioenergy production with CO2 capture and storage (CCS), overshoot concentration pathways, and the sensitivity of mitigation costs to policy and technology.
The report deals with: (1) two-phase flow regime transitions, (2) liquid entrainment in break flow, (3) vapor pull-through, and (4) CCFL in horizontal ducts. The first three processes influence the mass flow through the break, whereas the fourth one imposes a limit on liquid flow from the steam generator through the hot leg break into the core. Correlations available in the literature which deal with these processes are presented and applied to a hot leg of a PWR, LOFT and Semiscale for quantitative estimates, as well as for determining the scale distortion in the latter two facilities.
In the present paper a review of the Dutch RAS programme is presented. The objectives and achievements of the programme are described. Special attention is given to a recent assessment of the international status of P and T that has been made for the Dutch authorities. The major conclusion of this assessment is that P and T is an important instrument in the management of nuclear waste to achieve the technical limits (ALARA) with respect to radiotoxicity of the waste inventory as well as radiological effects of the disposal. The technology for P and T is, however, only partially available at present and recommendations for the directions of the RAS programme are given. (orig.).
Predicted by stochastic models and observed experimentally in a number of isomerization reactions, viscosity-induced solvent effects manifest themselves in a significant departure of the reaction rates from the values expected on the basis of transition state theory. These effects are well understood within the framework of stochastic models; however, the predictive power of such models is limited by the fact that their parameters are not readily available. Experiment and molecular dynamics (MD) simulations can provide such information and can serve as the testing grounds for various stochastic models. In real solvents, a change in viscosity is inevitably associated with variation of at least one of the three factors - temperature, pressure, or solvent identity, resulting in different solv...
This talk will present an overview of the use of mathematical programming techniques in manufacturing management practice. The emphasis is on applied contributions in three areas: conceptual and qualitative results, modelling, and algorithms. The discussion will be limited to methods that have found or are likely to find application in practice. Overall the picture is not heartening and many promising directions have not resulted in practical applications. Yet there are several areas where significant opportunities exist, though they seem to be better for heuristics than for highly structured traditional models. Time will be available for discussion of topics that interest the participants.
Environmental emissions constraints have led manufacturers to improve their low NO_x recuperative burners. The development by Tenova of the FlexyTech Flame-less burners with low NO_x emissions, even below the present 'Best Available Technology' limit of 40 ppm at 3% O_2 with furnace temperature 1250 C, air preheat 450 C, is described. The results achieved during the R and D programme have been also improved in the industrial installations. Some details and performances of the recent furnaces equipped with such burners are provided. (authors)
The near-term availability of domestic and selected foreign uranium resources for use by United States electric utilities is considered in light of projected geopolitical and socioeconomic considerations. No attempt is made to analyze the impact on domestic uranium supply of inflation or cost-price considerations, the introduction of the breeder reactor, limitations in enrichment capacity, or the presently expanding uranium inventory. All data are current as of mid-1980. The period with which this research is concerned is 1980-1995. It is concluded that the United States must promote responsible, environmentally acceptable uranium resource exploration and development, if this nation is to remain self sufficient in this necessary energy commodity.
Isotopic analyses of radioactive materials such as irradiated nuclear fuel are of major importance for the optimization of the nuclear fuel cycle and for safeguard aspects. Among the mass-spectrometric techniques available, inductively coupled plasma mass spectrometry (ICP-MS) and thermal ionization mass spectrometry are the most frequently applied methods for nuclear applications. Because of the low detection limits, the ability to analyze the isotopic composition of the elements and the applicability of the techniques for measuring stable as well as radioactive nuclides with similar sensitivity, both mass-spectrometric techniques are an excellent amendment to classical radioactivity counting methods. The paper describes selected applications of multicollector ICP-MS in combination with c...
This paper describes and analyzes a dithering technique for accurately specifying small values of opacity ({alpha}) that would normally not be possible because of the limited number of bits available in the alpha channel of graphics hardware. This dithering technique addresses problems related to compositing numerous low-opacity semitransparent polygons to create volumetric effects with graphics hardware. The paper also describes the causes and a possible solution to artifacts that arise from parallel or distributed volume rendering using bricking on multiple GPU's.
Over the past three decades, rising competition from television and other new media prompted the FCC to ease the responsibilities of radio stations to maintain extensive records of issues programming, while retaining the responsibility of stations to provide ready public access to records. This study investigated the availability of Issues-Programs Lists in nearly 100 Missouri radio station Public Files. One in five randomly sampled stations failed to produce access to Lists upon demand as required under federal law. Noncompliance themes include: Inability to access Public Files within 20 minutes of face-to-face requests; station personnel with limited or no knowledge of Files; denial of access to Files and Lists (i.e., verbal refusals, locked studio doors); and incomplete Files. The rate ...
The propagation of acoustic pressure perturbations in an adiabatic low-quality air/water flow were investigated both theoretically and experimentally. A linearized dispersion model is correlated with data to extract information on the behavior of interfacial momentum transfer controlled by the virtual volume coefficient. The dispersion model is examined in limiting cases of low and high frequency and related to current models for critical flow velocity. Fourier decomposition techniques are employed to predict the dispersion of measured pressure pulses and to relate data for standing waves and propagating pulses. The dispersion model is based on a two-fluid model and is the most complete model available in the literature at this time. The dispersion data presented herein is also the best available to date for low frequency (i.e., frequencies less than bubble resonance) sound propagation in bubbly air/water mixtures.
One proposed solution to the problem of ballast-mediated aquatic invasions involves chemically treating ballast water to kill key target organisms. Here, we examine the efficacy of three commercially available ballast water biocides using vegetative microalgae, dinoflagellate resting cysts and bacteria as test organisms. Chemicals tested were the ballast water biocides SeaKleen and Peraclean Ocean, and the chlorine dioxide biocide Vibrex. Results demonstrate that the applicability of each of the three chemical biocides as a routine ballast water treatment is limited by factors such as cost, biological effectiveness and possible residual toxicity of the discharged ballast water (assessed on the basis of impact on motility of vegetative marine microalgae). Of the three biocides tested, Perac...
The high-nickel austenitic alloy 800 (in both the mill-annealed and the solution-treated grades) has several attractive properties that make it a good candidate for service attractive properties that make it a good candidate for service at elevated temperatures in corrosive environments. One such property is creep resistance. This report analyzes the elevated-temperature creep behavior of the mill-annealed grade, generally referred to simply as alloy 800. (The solution-treated grade is known as alloy 800H). Available data over the temperature range from 538 to 760/sup 0/C were collected and evaluated to yield mathematically approximations for creep-rupture and strain-time behavior for use in design calculations. However, the creep behavior of this material is extremely complex, and the analysis presented here contains substantial uncertainties. All results in this report should be considered preliminary because of limited data currently ...
The problem of passively tracking a moving signal source has importance in a variety of applications such as radar, sonar, seismology, and radio astronomy. In many applications, only limited information is available about the signal source. It will be assumed here that only the signals which are detected by the sensors and the velocity of the source signal are known. The objective of this document is to present a program which passively tracks a target using an array of sensors. This program is available in MATLAB, version 3.5. The algorithm which is implemented consists of three main parts: time delay estimation, passive localization, and data post processing. Each of these parts are discussed, and the mathematical foundation for their solution given. Following, this the organization of the program is presented, and an example of its usage is given.
Radiopharmaceuticals for brain imaging are used for the detection of ischemia, tumours and dementia associatied with disorders of the blood flow in the brain. The current radiopharmaceuticals for brain imaging have various limitations: 2-(F-18)fluoro-2-deoxyglucose (F-18-FDG) has a very short half-life. The physical properties of di-#beta#-(piperidinoethyl)-(Se-75)selenide (Se-75-PIPSE) and di-#beta#-(morpholinoethyl)-(Se-75)-selenide (Se-75-MOSE) are not ideal. Thallium-201 diethyldithricarbamate (T1-201-DDC) has unfavourable nuclidic characteristics, limitedavailability, a long half-life and high cost. I-123 in N-isopropyl-p-iodoamphetamine (I-123-IMP) and N,N,N'-trimethyl-N'-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine (I-123-HIPDM) are not freely available and are expensive. N-13-labelled ammonia has a very short half-life. Technetium-99m hexamethylpropyleneamineoxime (Tc-99m-HM-PAO) is ...
Upper and lower thermal limits and temperature dependent growth were determined for a number of organisms (or populations) representing various functional groups of stream ecosystems (microconsumers, producers, and macroconsumers, shredders, collectors, scrapers, and predators). Although temperature functions as an overall control parameter, organic substrate (microconsumers) and inorganic nutrients (microconsumers and producers), light (producers) and food quality (macroconsumers) can modify thermal responses. Stream microorganisms typically grow below their thermal optima, community composition being determined by those that can manage the maximum growth at a given temperature utilizing a given organic substrate. Producers in first to third order streams are generally light limited (although nutrient availability is also important). Food quality, primarily a function of microbial biomass in the case of detritivores. can ...
Geothermal energy pile foundations are an alternative energy source for heating and cooling needs. Utilising this source of energy has great potential due to the environmental, economic and social benefits. This paper looks at an extensive amount of literature on the technology behind the system including the overall process, primary considerations for each of the main components including latest developments as well as design implications such as the integration of ground energy systems into structural piles of buildings. Environmental considerations including performance-dependent parameters of the subsurface are described. Main parameters include thermal conductivity, thermal diffusivity, specific heat capacity and moisture content. Temperature and groundwater effects are also discussed and design considerations are provided. Mathematical models are available to aid in the design of these systems but there are various other issues and complex parameters that ...
Ways of reducing the excessive energy consumption in the Polish sugar industry are examined. The three main areas where energy reduction measures might be taken are: reducing the process heat demand which arises from the need to evaporate excess water from the juice supplied to the crystallisers; improving the effectiveness of the thermal system by moving from the present four-effect evaporation to five-effect evaporation and using crystallisation vapours for juice heating; replacing old steam boilers with more efficient units. Most Polish sugar factories are relatively small, however, and the energy saving measures, all of which require the installation of more modern equipment, are not economically feasible in the short term. Moreover, the stringent limits on atmospheric emissions which come into effect in 1998 will require factories to use low-sulphur coal and install costly glue-gas cleaning equipment. With limited funds ...
The trace element selenium (Se) is required in the production of enzymes that protect mammalian cells from oxidative damage due to the byproducts of aerobic respiration. Its deficiency in livestock results in the nutritional muscular dystrophy called white muscle disease. This especially affects juveniles in the preweaning period. Symptoms have also been reported in wild herbivores on low-Se forage, and their appearance may be episodic, suggesting temporal variations in Se uptake by plants. Here, we report variations in selenium concentrations in Carex spp. sedges used as forage by bighorn sheep (Ovis canadensis) on summer range in the Wyoming, Wind River Mountains, and correlate those variations with soil conditions that affect the bioavailability of selenium. Variations in available Se are explained based upon the known oxidation/reduction chemistry of the element. It is concluded that water-saturated, alpine soils provide conditions suitable for the reduction of ...
This Environmental Assessment evaluates the proposed action to operate two laboratory-size muffle furnaces in glovebox HC-21C, located in the Plutonium Finishing Plant (PFP), Hanford Site, Richland, Washington. The muffle furnaces would be used to stabilize chemically reactive sludges that contain approximately 25 kilograms (55 pounds) of plutonium by heating to approximately 500 to 1000{degrees}C (900 to 1800{degrees}F). The resulting stable powder, mostly plutonium oxide with impurities, would be stored in the PFP vaults. The presence of chemically reactive plutonium-bearing sludges in the process gloveboxes poses a risk to workers from radiation exposure and limits the availability of storage space for future plant cleanup. Therefore, there is a need to stabilize the material into a form suitable for long-term storage. This proposed action would be an interim action, which would take place prior to completion of an Environmental Impact ...
The increase in world oil prices since 2003 has prompted renewed interest in producing and using liquid fuels from unconventional resources, such as biomass, oil shale, and coal. This book focuses on issues and options associated with establishing a commercial coal-to-liquids (CTL) industry within the United States. It describes the technical status, costs, and performance of methods that are available for producing liquids from coal; the key energy and environmental policy issues associated with CTL development; the impediments to early commercial experience; and the efficacy of alternative federal incentives in promoting early commercial experience. Because coal is not the only near-term option for meeting liquid-fuel needs, this book also briefly reviews the benefits and limitations of other approaches, including the development of oil shale resources, the further development of biomass resources, and increasing dependence on imported ...
Peeled Avena sativa coleoptile sections have been used to study the control of solute uptake under conditions where the uptake is not limited by the cuticular barrier. In the presence of 2% sucrose, auxin enhances the rate at which the total osmotic solutes increase, but this appears to be a response to the increased growth rate, inasmuch as the auxin effect is eliminated when growth is inhibited osmotically. When sections are incubated in sucrose or in 10 millimolar NaCl, the osmotic concentration increases until a plateau is reached after 8 to 24 hours. Auxin has no effect on the initial rate of increase in osmotic concentration. This difference in steady-state osmotic concentration is, in part, a response to auxin itself, as it persists when auxin-induced growth is inhibited osmotically. The upper limit for osmotic concentration does not appear to be determined by the turgor pressure, inasmuch as a combination of sucrose and NaCl gave a ...
This report documents a computable general equilibrium (CGE) model of the economy of Haiti, emphasizing energy use in agriculture. CGE models compare favorably with econometric models for developing countries in terms of their ability to take advantage of available data. The model of Haiti contains ten production sectors: manufacturing, services, transportation, electricity, rice, coffee, sugar cane, sugar refining, general agriculture, and fuelwood and charcoal. All production functions use functional forms which permit factor substitution. Consumption is specified for three income categories of consumers and a government sector with a linear expenditure system (LES) of demand equations. The economy exports four categories of products and imports six. Balanced trade and capital accounts are required for equilibrium. Total sectoral allocations of land, labor and capital are constrained to equal the quantities of these inputs in the Haitian economy as of the early ...
This paper presents a practical case study on the dynamic stability of the Saudi Electricity Company (SEC) power system and its effect on increasing power transfer limit of the interconnection between Eastern Operating Area (SEC-EOA). The problem of optimal tuning of the power system stabilizer parameters was converted into optimization problem wth eigenvalue-based objective functions, which was then solved by genetic algorithms. In this regard, two eigenvalue-based objective functions were considered and the problem is solved using real-coded genetic algorithm (RCGA). The effectiveness of the suggested technique to enhance the power system dynamic stability and to extend the power transfer capability limit of the SEC-EOA and the SEC-EOA power system was verified through a comprehensive eigenvalue analysis and time-domain nonlinear simulation. The results also indicated that the proposed tuning schemes of the existing stabilizers in the system ...
The resolution of X-ray diffraction microscopy is limited by the maximum dose that can be delivered prior to sample damage. In the proposed Serial Crystallography method, the damage problem is addressed by distributing the total dose over many identical hydrated macromolecules running continuously in a single-file train across a continuous X-ray beam, and resolution is then limited only by the available molecular and X-ray fluxes and molecular alignment. Orientation of the diffracting molecules is achieved by laser alignment. We evaluate the incident X-ray fluence (energy/area) required to obtain a given resolution from (1) an analytical model, giving the count rate at the maximum scattering angle for a model protein, (2) explicit simulation of diffraction patterns for a GroEL-GroES protein complex, and (3) the frequency cut off of the transfer function following iterative solution of the phase problem, and reconstruction ...
Research is in progress to obtain a satisfactory creep ductility for alloy 800 when used as heat exchanger material in sodium-cooled fast reactors (LMFBR). The creep test characteristics at present available show that a pronounced tendency to reduced elongation by creep failure may arise after prolonged testing in the 500-700 deg C temperature range. This phenomenon is now agreed to be primarily inherent to the conditions for Ni_3(Ti,Al) precipitation in the material and hence to the Ti and Al concentrations. By structural studies and hardness measurements on material subjected to creep tests and taken from a large number of castings, the relationship was established between the (Ti+Al) content and the structural hardness effect of Ni_3(Ti,Al) at 600 deg C. Below a certain Ti+Al concentration, no precipitation occurs and hence the creep ductility to failure can be improved considerably by limiting the allowed Ti+Al content in the material, ...
This cost-effectiveness analysis presents an evaluation of the technical efficiency of pollutant control options for the proposed Effluent Limitations Guidelines and Standards for the Transportation Equipment Cleaning Industry based on Best Available Technology Economically Achievable (BAT) and Pretreatment Standards for Existing Sources (PSES). Section 2 discusses EPA`s cost-effectiveness methodology and identifies the pollutants included in the analysis. This section also presents EPA`s toxic weighting factors for each pollutant and considers the removal efficiency of each pollution control option. Section 3 describes the options evaluated for each subcategory. Section 4 presents the results of the cost-effectiveness analysis. In Section 5, cost-effectiveness values for proposed TEC industry options are compared to cost-effectiveness values for other promulgated rules. Section 6 discusses the two-part cost-reasonableness test for BCT options. ...
Efforts have been made to develop fuel cell powered EVs (electric vehicles) in several countries and to demonstrate its high potential. Since 1990 fuel cell research has been conducted at FUT (the Fukui University of Technology) beginning with PAFC. Research effort is now being focused upon the application of fuel cells to the EV drive as this technology shows great future potential, particularly in the area concerning environmental protection. PEFC (Polymer Electrolyte Fuel Cell) has been chosen as the fuel cell for the EV power source because it possesses an inherent high power density and it also has another important feature; operation can be started under ambient temperature without preheating. The principal objective of this research is to pursue the optimum system of a PEFC drive EV. The size of the prototype vehicle in the university project is limited to a certain range and the capacity of the PEFG stack is also limited, for the time ...
Prepared by volunteers representing a wide range of interests and experience and including students with disabilities, this guide provides basic information about support services available to students with disabilities at public and private postsecondary education institutions in the State of Washington. The guide may also serve as a resource for family members, school counselors and others who assist students in furthering their education. The first section presents general information, discussing students' rights to appropriate education, giving basic rules for managing the transition to college life, charting effects of functional limitations in the academic setting, and providing a planning checklist for new students. Institutional profiles are presented in the second section, covering vocational-technical institutes (5), community colleges (27), and 4-year colleges and universities (16). Information is included on contact person, ...
The U.S. Department of Energy (DOE)-Carlsbad Field Office (CBFO) has developed draft documentation to present the proposed Waste Isolation Pilot Plant (WIPP) remote-handled (RH-) transuranic (TRU) waste characterization program to its regulators, the U.S. Environmental Protection Agency and the New Mexico Environment Department. Compliance with Title 40, Code of Federal Regulations, Parts 191 and 194; the WIPP Land Withdrawal Act (PL 102-579); and the WIPP Hazardous Waste Facility Permit, as well as the Certificates of Compliance for the 72-B and 10-160B Casks, requires that specific waste parameter limits be imposed on DOE sites disposing of TRU waste at WIPP. The DOE-CBFO must control the sites' compliance with the limits by specifying allowable characterization methods. As with the established WIPP contact handled TRU waste characterization program, the DOE-CBFO has proposed a Remote-Handled TRU Waste Acceptance Criteria (RH-WAC) ...
This paper identifies some of the issues which arise in the consideration of the derivation of new limits on exposure to internal emitters. Basic and secondary radiation protection limits are discussed. Terms are defined and applied to the limitation of risk from stochastic effects. Non-stochastic data for specific internal emitters (/sup 131/I and the radium isotopes) are presented. Emphasis is placed on the quantitative aspects of the limit setting problem. 65 references, 2 figures, 12 tables.
Stereotactic radiosurgery (SRS) precisely delivers high-dose radiation to a small target (usually less than 3-4 cm in diameter), in a single session with steep dose-fall, employing various radiation methods. SRS provides good tumor control for small brain metastases from various primary cancers, with minimal untoward effects on surrounding normal brain. This excellent tumor control prevents neurological death and maintains good activity of daily life. Although surgery with whole-brain radiation therapy (WBRT) remains an important option for patients with a solitary brain metastasis, SRS with or without WBRT should be considered in patients with a limited number of small tumors and a good prognosis. Many reports, as well as both retrospective and prospective reviews, have shown WBRT before or after SRS to improve local control and reduce new distant lesion emergence. However, upfront WBRT does not improve survival. There are two major delivery techniques, Gamma ...
Active Process Water (APW) system is provided as a unitized system in TAPP-3 and 4. Maintenance on APW system requires shutdown of this system. As shut down heat exchangers are fed by APW system; during APW system shutdown cold shutdown state cannot be maintained. Therefore safety analysis is done to optimize the duration of reactor shutdown (which means low decay heat) after which APW shutdown can be taken with minimum water supply to the shutdown heat exchangers. Based on this analysis, it is proposed in technical specification that APW system shutdown can be taken after 7 days of reactor shutdown with shutdown heat exchangers supplied with about 20 % of normal APW flow. With this configuration, PHTS, moderator, end shield, calandria vault water temperature can be maintained within limits. A design provision is made at TAPP-3 and 4 to interconnect APW system of both units in such a way that one unit in addition to its own APW requirement can provide ...
An experimental investigation on the air/water counter-current two-phase flow in a horizontal rectangular channel connected to an inclined riser has been conducted. This test-section representing a model of the hot leg of a pressurized water reactor is mounted between two separators in a pressurized experimental vessel. The cross-section and length of the horizontal part of the test-section are (0.25 m x 0.05 m) and 2.59 m, respectively, whereas the inclination angle of the riser is 50 deg. The flow was captured by a high-speed camera in the bended region of the hot leg, delivering a detailed view of the stratified interface as well as of dispersed structures like bubbles and droplets. Countercurrent flow limitation (CCFL), or the onset of flooding, was found by analyzing the water levels measured in the separators. The counter-current flow limitation is defined as the maximum air mass flow rate at which the discharged water mass flow rate is ...
The object of this study was to identify those areas in California where synthetic fuel-fired power plants could be sited in the 1990 time frame, from an air quality perspective. The synfuel-fired power plants considered in this new study were 500 Mw methanol-fired combined cycle (MFCC) and 500 Mw integrated gasifier combined-cycle (IGCC) units. For comparison purposes, 500 Mw direct coal-fired boilers and 500 Mw natural gas-fired combined-cycle units were also considered. Staff did not attempt to locate plants at any specific sites, but relied primarily upon a regional countywide analysis. The study provides an approximation, for planning purposes, of a reasonable limit of the state's power plant siting capacity, given the plant types and sizes, conditions, and assumptions specified. The study shows that local emission limitations often preclude certain types of power plants (particularly direct-fired coal plants) even when they are ...
Those areas in California where synthetic fuel-fired power plants could be sited in the 1990 time frame, from an air quality perspective were identified. The synfuel-fired power plants considered in this new study were 500 MW methanol-fired combined cycle (MFCC) and 500 MW integrated gasifier combined-cycle (IGCC) units. For comparison purposes, 500 MW direct coal-fired boilers and 500 MW natural gas-fired combined-cycle units were also considered. The study provides an approximation, for planning purposes, of a reasonable limit of the state's power plant siting capacity, given the plant types and sizes, conditions, and assumptions specified. The study shows that local emission limitations many times preclude certain types of power plants even when they are equipped with Best Available Control Technology (BACT) as required by NSR regulations. This study also shows that 4000 MW of direct-fired coal plants could ...
Background Limited data is available for investigating the long-term safety and effects of intracoronary progenitor cell therapy in patients with acute myocardial infarction (AMI). Objective To assess the clinical course, NT-proBNP and MRI data as objective markers of cardiac function of the TOPCARE-AMI patients at 5-year follow-up. Design The TOPCARE-AMI trial was the first randomized study investigating the effects of intracoronary infusion of circulating (CPC) or bone marrow-derived progenitor cells (BMC) in 59 patients with successfully reperfused AMI. Results Five-year follow-up data were completed in 55 patients, 3 patients were lost to follow-up. None of the patients showed any signs of intramyocardial calcification or tumors at 5?years. One patient died during the initial hospitali...
The need for alternative energy increases steadily???especially due to the climate change and the limitedavailability of fossil fuels. Geothermal power uses the intrinsic heat which is stored in the accessible part of the Earth???s crust. Its importance among the renewable energy resources originates from the almost unlimited energy supply of the Earth and its independence from external influences such as seasonal or even daily climatic variability. Nevertheless, there are risks which have to be assessed. From a mathematical point of view there are four building blocks of the characterization of deep geothermal systems: seismic exploration, gravimetry, modeling transport processes, and modeling the stress field. In particular, local depletion poses a significant risk during the industrial...
Full text: The nuclear renaissance, anticipated by AREVA in the beginning of the century is now happening in several countries around the world. The fundamentals being the increasing demand of energy, the volatility of fossil fuel prices, the awareness of climate change threat connected with the extensive use of fossil fuels. The EPRTM reactor present significant improvements compared to previous generation reactors enabling to reach an outstanding safety level (redundancy of safety systems, airplane crash resistance), to improve the economics (extended plant lifetime, flexibility and availability during operation and, increased efficiency and fuel utilization) while limiting the impact on workers and the environment. Several countries have been implementing the transition to third generation reactors. The presentation will analyze different examples in order to draw the lessons learned from this first wave and to set-up the criteria for a ...
Reactor Power Measurement is an essential part of the Reactor Power Control Loop in PHWRs. None of the available power measuring sensor offers characteristics which allow their direct use in the Reactor Power Control Loop. Thermal power, which is considered as relatively accurate, suffers from measurement delays and is used only as reference. Neutronic power sensors like Ion Chambers and Self Powered Neutron Detectors (SPNDs) which sense instantaneous power suffer from inaccuracies. A technique is required which makes use of both types-reference power and instantaneous power to extract real power information from the signals. This paper describes techniques to calibrate (correct) neutronic power that with the thermal reference power signals. The paper also brings out limitation of the calibration technique. (author)
Case studies of natural wetlands for treating mine drainage are described. Most of the sites are in northern Canada. The natural wetlands examined suggest that constructed wetlands are a viable option for the passive treatment of mine drainage. Natural wetlands retain many metals, and many species of plants are represented in them. Processes for metal removal include sorption onto organic matter, hydrolysis, and reduction. The results show that wetlands need not be based on cattails to be effective, and that passive mine drainage treatment is feasible in northern regions. Few examples are available of constructed wetlands for treating metal mine drainage. It is concluded that the limitations of constructed wetlands are found not in the wetlands, but in information about them. 37 refs., 1 fig., 2 tabs.
Background The 2003 outbreak of severe acute respiratory syndrome (SARS) infected over 8000 people and killed 774. Transmission of SARS occurred through direct and indirect contact and large droplet nuclei. The World Health Organization recommended the use of household disinfectants, which have not been previously tested against SARS coronavirus (SARS-CoV), to disinfect potentially contaminated environmental surfaces. There is a need for a surrogate test system given the limitedavailability of the SARS-CoV for testing and biosafety requirements necessary to safely handle it. In this study, the antiviral activity of standard household products was assayed against murine hepatitis virus (MHV), as a potential surrogate for SARS-CoV. Methods A surface test method, which involves drying an amo...
We conducted broadband absorption measurements of atmospheric water vapor in the ground state, X {sup 1}A{sub 1} (000), from 0.4 to 2.7 THz with a pressure broadening-limited resolution of 6.2 GHz using pulsed, terahertz time-domain spectroscopy (THz-TDS). We measured a total of seventy-two absorption lines and forty-nine lines were identified as H{sub 2}{sup 16}O resonances. All the H{sub 2}{sup 16}O lines identified were confirmed by comparing their center frequencies to experimental values available in the literature.
This report reviews system safety analysis methods and examines their application to nuclear waste management systems. The safety analysis methods examined include expert opinion, maximum credible accident approach, design basis accidents approach, hazard indices, preliminary hazards analysis, failure modes and effects analysis, fault trees, event trees, cause-consequence diagrams, G0 methodology, Markov modeling, and a general category of consequence analysis models. Previous and ongoing studies on the safety of waste management systems are discussed along with their limitations and potential improvements. The major safety methods and waste management safety related studies are surveyed. This survey provides information on what safety methods are available, what waste management safety areas have been analyzed, and what are potential areas for future study.
Abstract The available surface equation of state for pure pulmonary surfactant monolayers is generalised to binary mixture monolayers by introducing a group of parameters, i(i-=-1-4) in the form of $x_{r}^{\\beta _{i} } $ to express the influence of the components in new mixing rules and a new factor, I $\\left[ { = \\left( {\\prod\\limits_{i = 1}^{4} {\\beta _{i} } } \\right)^{{\\raise0.5ex\\hbox{$\\scriptstyle 1$}\\kern-0.1em/\\kern-0.15em\\lower0.25ex\\hbox{$\\scriptstyle {4}$}}} } \\right]$, is defined to represent the interaction intensity between two different components. The ---A isotherms getting by the surface equations of state agree with the experimental data for protein-lipid binary monolayers, and the average deviation is about 11.41%. The result shows the order of the interaction intensity b...
Many nations and international agencies are working to develop improved technology and industrial capability for neuclear fuel cycle and waste management operations. The effort in some countries is limited to research in university laboratories on treating low-level waste from reactor plant operations. In other countries, national nuclear research institutes are engaged in major programs in all phases of the fuel cycle and waste management, and there is a national effort to commercialize fuel cycle operations. Since late 1976, staff members of Pacific Northwest Laboratory have been working under US Department of Energy sponsorship to assemble and consolidate openly available information on foreign and international nuclear waste management programs and technology. This report summarizes the information collected on the status of fuel cycle and waste management programs in selected countries making major efforts in these fields as of the end of ...
Creation of new multi-composite materials is an essential issue to attain an innovative improvement of the current nuclear technology. In this paper, some highlights are focused on the research of creation of those materials and the relating subjects in NIRIM. (1) The KOH corrosion test method are expected to be efficiently available in the limited cases instead of Na corrosion test one. (2) The preliminary creation of the multi-composite ceramics were achieved by Y- ion implantation into sapphire and the RF sputtering, of which the specified orientation was realized by the existence of the buffer layer. The importance of the defect control are described with the relation to the corrosion resistance improvement. (3) The ion beam induced phenomena have been investigated on the surface change of silica glass and the crystallization of Cu film on SrTiO{sub 3}. (4) The electronic states of the alkali-metal adsorbed surfaces and that of the ...
The ever increasing fossil fuel usage and cost, environmental concern has forced the world to look for alternatives. Straight vegetable oils in compression ignition engine are a ready solution available, however, with certain limitations and with some advantages as reported by many researchers. A comprehensive and critical review is presented specifically pertaining to straight vegetable oils usage in diesel engine. A detailed record of historical events described. Research carried out specifically under Indian conditions and international research work on the usage of straight vegetable oils in the diesel engine is separately reviewed. Many researchers have reported that straight vegetable oils in small percentage blends with diesel when used lower capacity diesel engines have shown great...
Ground-water monitoring near the Raft River site was initiated in 1974 by the IDWR. This effort consisted of semiannual chemical sampling of 22 irrigation wells near the Raft River geothermal development area. This program yielded useful baseline chemical data; however, several problems were inherent. For example, access to water pumped from the wells is limited to the irrigation season (April through September). All the wells are not continuously pumped; thus, some wells that are sampled one season cannot be sampled the next. In addition, information on well construction, completion, and production is often unreliable or not available. These data are to be supplemented by establishing a series of monitor wells in the proposed geothermal withdrawal and injection area. These wells were to be located and designed to provide data necessary for evaluating and predicting the impact of geothermal development on the Shallow Aquifer system.
The estimation of radiation dose to man from either external or internal exposure to radionuclides requires a knowledge of the energies and intensities of the atomic and nuclear radiations emitted during the radioactive decay process. The availability of evaluated decay data for the large number of radionuclides of interest is thus of fundamental importance for radiation dosimetry. This handbook contains a compilation of decay data for approximately 500 radionuclides. These data constitute an evaluated data file constructed for use in the radiological assessment activities of the Technology Assessments Section of the Health and Safety Research Division at Oak Ridge National Laboratory. The radionuclides selected for this handbook include those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion reactor technology, and some of ...
The existence of multipole components in the dipole and quadrupole magnets is one of the factors limiting the beam stability in the RHIC operations. So, a realistic non-linear model is crucial for understanding the beam behavior and to achieve the ultimate performance in RHIC. A procedure is developed to build a non-linear model using the available multipole component data obtained from measurements of RHIC magnets. We first discuss the measurements performed at different stages of manufacturing of the magnets in relation to their current state in RHIC. We then describe the procedure to implement these measurement data into tracking models, including the implementation of the multipole feed down effect due to the beam orbit offset from the magnet center. Finally, the field quality analysis in the RHIC interaction regions (IR) is presented.
The Savannah River Site disposes of low-level radioactive waste within on-site engineered disposal facilities. The Savannah River Site must demonstrate that these disposals meet the requirements of DOE Order 435 . 1 through a process known as performance assessment (PA). The objective of this document is to provide the radionuclide -specific data needed for the PA calculations . This work is part of an on-going program to periodically review and update existing PA work as new data becomes available. Revision of the E -Area Low-Level Waste Facility PA is currently underway. The number of radionuclides selected to undergo detailed analysis in the PA is determined by a screening process. The basis of this process is described. Radionuclide-specific data for half-lives, decay modes, daughters, dose conversion factors and groundwater concentration limits are presented with source references and methodologies.
This study is an attempt to measure the quantities of elements in a composite by irradiating that composite with #gamma#-rays of various energies and detecting the transmitted radiation through the composite. A previous knowledge of the number of the elements and their attenuation coefficients is required. The quantities are calculated by solving the matrix of a linear system of equations. A computer program was developed to select the best combinations of the available energies. Five criteria were established to determine these energy combinations: (i) the determinant of the attenuation coefficient matrix; (ii) the condition number, (iii) the number of times the solution of the matrix leads to acceptable results; (iv) the indicator, (a new concept); (v) the standard deviations of the results. The intended application of this technique in medicine is to measure the bone mineral content of the skeleton. An examination of the error propagation, the application of ...
Availability of a natural gas-powered van that meets California`s ultra low emission vehicle requirements and has a 300-km range was reported. A similar van with an electric system giving a range of 240 km was also within sight. Regarding the limitations of electric batteries it was suggested that a super capacitor may allow systems to achieve higher energy densities; a refuelable zinc-air battery could be considered for vehicle use. While the prospect for emissions improvement of gasoline vehicles has clearly improved in recent years, the relative costs of infrastructure, vehicle and fuel for the the alternative fuels compared with gasoline demonstrate the difficulty the alternative fuels have in taking market share from gasoline. For the next decade, gasoline, propane and CNG are expected to be the dominant fuels for vehicles. After that, the leading fuel will be the one that has been most extensively researched and developed during the ...
Cosmic ray antiprotons provide an important probe for the study of cosmic ray propagation in the interstellar space and to investigate the existence of Galactic dark matter. The ARGO-YBJ experiment is observing the Moon shadow with high statistical significance at an energy threshold of a few hundred GeV. Using all the data collected until November 2009, we set two upper limits on the antip/p flux ratio: 5% at an energy of 1.4 TeV and 6% at 5 TeV with a confidence level of 90%. In the few-TeV range the ARGO-YBJ results are the lowest available, useful to constrain models for antiproton production in antimatter domains.
Abstract A Pseudomonas sp. isolate MSB1 efficiently inhibited the growth of Flavobacterium psychrophilum of different serotypes on agar medium. A significant difference in the inhibition was observed between isolates of the less virulent FpT serotype compared to the Fd and Th serotypes. In broth coculture experiments, a low number of cells of MSB1 inhibited and outcompeted the F.psychrophilum cells. Also cell-free culture supernatant of MSB1 clearly repressed the growth of F.psychrophilum. A chromoazurol S assay suggested that MSB1 produced efficient siderophores, which most probably were responsible for the iron deficiency in the supernatant. The limited growth of F.psychrophilum in the supernatant was found to be partly because of the lack of available iron, but the results also indicate...
An image-analysis system, based on commercially available data visualization software (IDL [1]), allows convenient interaction with image data while still providing calculated beam parameters at a rate of up to 2 Hz. Image data are transferred from the IOC to the workstation via EPICS [2] channel access. A custom EPICS record was created in order to overcome the channel access limit of 16k bytes per array. The user can conveniently calibrate optical transition radiation (OTR) and fluorescent screens, capture background images, acquire and average a series of images, and specify several other filtering and viewing options. The images can be saved in either IDL format or APS-standard format (SDDS [3]), allowing for rapid postprocessing of image data by numerous other software tools.
Discovery of better biomarkers for diagnosis, prognosis, and therapy-response prediction is the most critical task of a scientific quest aimed at developing newly designed, tailor-made therapies for patients with cancer. Consequently, a proteome wide analysis, in addition to genomic studies, is an absolute requirement for a complete functional understanding of tumor biology. Ultra-sensitive, high-performance Fourier transform ion cyclotron resonance (FTICR) mass spectrometry (MS) currently holds an important role in fulfilling the demands of biomarker discovery. In this review, we describe the applicability of FTICR MS for breast cancer proteomics, particularly for the analysis of complex protein mixtures obtained from a limited number of cells typically available from clinical specimens.
Outcome from trauma, surgery, and a variety of other medical conditions has been shown to be positively affected by providing treatment at facilities experiencing a high volume of patients with those conditions. An electronic literature search was made to identify English-language articles available through March 2011, addressing the effect of patient treatment volume on outcome for patients with subarachnoid hemorrhage. Limited data were identified, with 16 citations included in the current review. Over 60% of hospitals fall into the lowest case-volume quartile. Outcome is influenced by patient volume, with better outcome occurring in high-volume centers treating >60 cases per year. Patients treated at low-volume hospitals are less likely to experience definitive treatment. Furthermore, t...
It is known that the plant cuticle represents the first barrier that must be overcome by any chemical reaching the plant surface from the atmosphere before entering the plant. Because of the importance of the cuticle as a barrier to penetration of a wide variety of compounds, its morphology, chemistry, and permeability have been extensively studied. However, only limited information is available on the nature of functional chemical groups present and their interaction and role during the penetration process. The usefulness of in situ Fourier transform infrared spectroscopy studies in identifying functional groups present in isolated cuticles is described and their relationships to the structure of the cuticular membrane are discussed. Applications of infrared spectroscopy on the presence and role of phenolics in the cuticle structure and during the cuticle development, nitrogen oxide binding to isolated cuticles, and the interactions between ...
This environmental assessment quantifies the water quality-related benefits for Transportation Equipment Cleaning (TEC) facilities based on site-specific analyses of current conditions and the conditions that would be achieved by process changes under proposed BAT (Best Available Technology) and PSES (Pretreatment Standards for Existing Sources) controls. The US Environmental Protection Agency (EPA) estimated instream pollutant concentrations for 157 priority and nonconventional pollutants from three subcategories (barge-chemical and petroleum, rail-chemical, and truck-chemical) of direct and indirect discharges using stream dilution modeling. The potential impacts and benefits to aquatic life are projected by comparing the modeled instream pollutant concentrations to published EPA aquatic life criteria guidance or to toxic effect levels.
Of the many energy-conservation options available to the design engineer, a system-management approach is recommended as one that will effect maximum benefits to the owner. Systems management includes energy-conscious consideration of design criteria, design details, installation, testing and balancing, and operation. It requires the informed participation of the design engineer, contractor, testing and balancing (TAB) engineer, and owner/operator. Within limits, almost every component of HVAC systems offers an opportunity to conserve energy. Many of these impact energy determinants such as system static pressure, system total air flow, or the quantity of outside air. A few design considerations for energy conservation in a simple system and the impact that the TAB work has on these are illustrated. Particular attention is devoted to the energy impact of systems management, makeup air, and system static pressure.
High temperature proton conductor (HTPC) oxides are attracting extensive attention as electrolyte materials alternative to oxygen-ion conductors for use in solid oxide fuel cells (SOFCs) operating at intermediate temperatures (400-700 "0C). The need to lower the operating temperature is dictated by cost reduction for SOFC pervasive use. The major stake for the deployment of this technology is the availability of electrodes able to limit polarization losses at the reduced operation temperature. This review aims to comprehensively describe the state-of-the-art anode and cathode materials that have so far been tested with HTPC oxide electrolytes, offering guidelines and possible strategies to speed up the development of protonic SOFCs. (topical review)
The role of adaptation in the divergence of lineages has long been a central question in evolutionary biology, and as multilocus sequence data sets have become available for a wide range of taxa, empirical estimates of levels of adaptive molecular evolution are increasingly common. Estimates vary widely among taxa, with high levels of adaptive evolution in Drosophila, bacteria, and viruses but very little evidence of widespread adaptive evolution in hominids. Although estimates in plants are more limited, some recent work has suggested that rates of adaptive evolution in a range of plant taxa are surprisingly low and that there is little association between adaptive evolution and effective population size in contrast to patterns seen in other taxa. Here, we analyze data from 35 loci for si...
Abstract BACKGROUND: In Brazil, the usual forms of zinc (Zn) supply to coffee plants have limitations that compromise the element availability to the plant. This study proposes to test an alternative approach to supplying the nutrient to Coffea arabica L. using trunk implanted zinc tablets. Additionally, the effect of Zn on the production and quality of coffee beans was also evaluated. RESULTS: The highest total coffee bean production was recorded in plants implanted with Zn tablets (TA), while the lowest was recorded in the control treatment, without zinc supply (WZn), reaching a bianual production of 188.2 and 130.1 60-kg bags of processed beans per hectare, respectively. In the treatments where Zn were applied as tablet implantation or as foliage spraying (SZn); the bean size was larger...
Dispersed flow film boiling is the heat transfer regime that occurs at high void fractions in a heated channel. The way this transfer mode is modelled in the NRC computer codes (RELAP5 and TRAC) and the validity of the assumption and empirical correlations used is discussed. An extensive review of the theoretical and experimental work related with heat transfer to highly dispersed mixtures reveals the basic deficiencies of these models: the investigation refers mostly to the typical conditions of low rate bottom reflooding, since the simulation of this physical situation by the computer codes has often showed poor results. The alternative models that are available in the literature are reviewed, and their merits and limits are highlighted. The modification that could improve the physics of the models implemented in the codes are identified. (author) 13 figs., 123 refs.
Purpose - This article aims to examine approaches by academic libraries in demonstrating return on investment (RoI). Design/methodology/approach - As a participant in a recent international RoI study, the author reviews the various difficulties in developing a suitable methodology. Findings - Using grant income as the basis for demonstrating RoI, it was found that wide differences in results may be attributable to a number of factors related to the parent organisation, the availability of grant funding and the country of the study. Research limitations/implications - Further work is necessary to arrive at a suitable methodology for a diverse range of academic libraries. Practical implications - Library managers are alerted to issues and problems surrounding the development of return on inv...
The Department of Energy (DOE) policy requires that all DOE activities be conducted in a manner that protects the safety of the public and provides a safe and healthful workplace for employees. DOE has also prescribed that all personnel be protected in any explosives operation undertaken. The level of safety provided shall be at least equivalent to that of the best industrial practice. The risk of death or serious injury shall be limited to the lowest practicable minimum. DOE and contractors shall continually review their explosives operations with the aim of achieving further refinements and improvements in safety practices and protective features. This manual describes the Department's explosive safety requirements applicable to operations involving the development, testing, handling, and processing of explosives or assemblies containing explosives. It is intended to reflect the state-of-the-art in explosives safety. In addition, it is essential that ...
An assessment is made of the biological effects and physical hazards of static and time-varying fields associated with the NMR devices that are being used for clinical imaging and in vivo spectroscopy. A summary is given of the current state of knowledge concerning the mechanisms of interaction and the bioeffects of these fields. Additional topics that are discussed include: (1) physical effects on pacemakers and metallic implants such as aneurysm clips, (2) human health studies related to the effects of exposure to nonionizing electromagnetic radiation, and (3) extant guidelines for limiting exposure of patients and medical personnel to the fields produced by NMR devices. On the basis of information available at the present time, it is concluded that the fields associated with the current generation of NMR devices do not pose a significant health risk in themselves. However, rigorous guidelines must be followed to avoid the physical ...
The performance of a gas-fuelled diesel engine (dual fuel) is examined at light load and an effective threshold limit to the combustion of the gaseous fuel through bulk flame spread is identified. The relationship of such a limit to some of the key operating parameters is then discussed. A comparison between the measured values of the limit with those corresponding to the lower flammability limits of the gaseous fuel when evaluated under the prevailing cylinder conditions during pilot diesel fuel ignition showed similar trends. It is suggested that such a similarity may form a basis for estimating the lean operation limits for duel a fuel combustion in engines. A simple approach for estimating the limiting equivalence ratio for the apparent bulk flame spread limit is described for a methane-fuelled dual fuel engine. (Author)
For more than thirty years, the IAEA has published a set of documents aimed at the limitation of the radiation exposure of the population from various nuclear activities. In particular, in 1994 the IAEA published Technical Reports Series No. 364, Handbook of Parameter Values for the Prediction of Radionuclide Transfer in Temperate Environments. Over the years, it has proved to be a valuable reference for radioecologists, modellers and authorities in Member States, and has been quoted in numerous impact assessments. Technical Reports Series No. 364 was based on a review of available data up to the end of 1992. However, a number of high quality critical reviews have been produced in recent years for some of the transfer parameter values which merit consideration. Thus, it was assumed that there is sufficient new information available to warrant reconsideration of a significant proportion of the values given in Technical ...
Microbial dechlorination of polychlorinated biphenyls (PCBs) often stops although a significant number of removable chlorines remain. To determine the reason for the cessation, we investigated the limitation of organic carbon, PCB bioavailability, and inhibition by metabolic products. Enrichment with carbon sources did not induce additional chlorination, indicating the plateau was not due to depletion of organic carbon. The bioavailability was not limiting, since a subcritical micelle concentration of the surfactant, which enhanced desorption without inhibiting dechlorinating microorganisms, failed to lower the plateau. Neither was it due to accumulation of metabolites, since no additional dechlorination was detected when plateau sediments were incubated with fresh medium. Similarly, dechlorination was not inhibited in freshly spiked sediment slurries. Dechlorination ended up at the same level with nearly identical congener profiles, regardless ...
The advancement of bioprocess monitoring will play a crucial role to meet the future requirements of bioprocess technology. Major issues are the acceleration of process development to reduce the time to the market and to ensure optimal exploitation of the cell factory and further to cope with the requirements of the Process Analytical Technology initiative. Due to the enormous complexity of cellular systems and lack of appropriate sensor systems microbial production processes are still poorly understood. This holds generally true for the most microbial production processes, in particular for the recombinant protein production due to strong interaction between recombinant gene expression and host cell metabolism. Therefore, it is necessary to scrutinise the role of the different cellular compartments in the biosynthesis process in order to develop comprehensive process monitoring concepts by involving the most significant process variables and their interconnections. Although research ...
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 develop a general-purpose software and communications link between the cycle analysis software Aspen ...
Carpal tunnel syndrome (CTS) is a common disorder, for which various conservative treatment options are available. The objective of this study is to determine the efficacy of the various conservative treatment options for relieving the symptoms of CTS. Computer-aided searches of MEDLINE (1/1966 to 3/2000), EMBASE (1/1988 to 2/2000) and the Cochrane Controlled Trials Register (2000, issue 1) were conducted, together with reference checking. Included were randomised controlled trials evaluating the efficacy of conservative treatment options in a study population of CTS patients, with a full report published in English, German, French or Dutch. Two reviewers independently selected the studies. Fourteen randomised controlled trials were included in the review. Assessment of methodological quality and data-extraction was independently performed by two reviewers. A rating system, based on the number of studies and their methodological quality and findings, was used to ...
Literature on examples of phytoremediation techniques used in the in-situ remediation of soils contaminated by petroleum hydrocarbons is reviewed. The review includes discussion of the key mechanisms involved in each case, benefits, limitations and costs compared to alternative approaches, including natural attenuation, engineering and bioremediation. Review of the literature led to the conclusion that phytoremediation is an effective method for degrading and containing petroleum hydrocarbons in soil, and confirmed the ability of plants to transfer volatile petroleum hydrocarbons, such as napthalene, from the soil to the atmosphere via transpiration. The primary loss mechanism for the degradation of petroleum hydrocarbons appears to be microorganisms in the rhizosphere of plants. The available information also suggests that plants may degrade petroleum hydrocarbons directly, although the indirect role played by plants is far more common. These ...
A review of current daylighting design tools indicates that over 30 tools are now available, including nomographs, protractors, overlays, and programs for micro-, mini-, and mainframe computers. Computer-based tools allow testing and analyzing of more design alternatives under a wider variety of conditions than was previously practical with slower techniques, but they have not fundamentally changed the information available to the design professional. These tools are applicable to certain limited functions of the design process and do not address the varying information needs of the designer at various points in the design process. We describe a concept for a computer-based building envelope design tool that is structured to overcome many of the limitations of the existing tools. The tool would address daylighting design in the context of the overall building envelope design, covering a range of ...
The Doublet III device is operating with an extensive system of plasma limiters and wall protective armor. Operations with up to 8MW of neutral beam power and 1.5MA plasma current are planned. Design and operational performance of the following systems are discussed: 1. Water-cooled graphite moveable limiter. 2. Water-cooled graphite fixed limiter and neutral beam wall armor. 3. Radiatively cooled Inconel divertor plates.
Steam turbines have reached a high level of technology. Development projects, leading to further improvement of turbines or to new concepts, usually last several years. Turbine manufacturers have therefore already been dealing with the question of market requirements in the 80's for some time. Developments in this decade will be marked less by the need for higher turbine ratings than by the necessity to increase efficiency and improve availability. Only in this way can the considerable increases in fuel costs be effectively countered. Improvements stemming from the steam process must be utilized to a large extent. However, plant availability sets a limit on these endeavours. The application of knowledge gained in the last years, in the field of materials research and numerical methods for problems of flow and mechanical engineering, will make it possible to optimize dimensioning and design of steam turbines, with a view to ...
The radioiodine-labeled amines currently available as brain-imaging agents, based on our previous work and that of others, are prepared either by exchange labeling or by direct iodination of a protected intermediate. The intrinsic slowness of these processes limits their potential for use with the positron-emitting 122I, as it has a half-life of only 3.6 min. This isotope has advantages of a low dose to the patient and availability from a generator containing the parent 20-h 122Xe. To develop a radiopharmaceutical in which 122I could be utilized, we prepared a number of secondary and tertiary amines (maintaining the 2,5-dimethoxy substitution pattern which allows direct iodination at the 4-position) with 131I. The organ distributions of these compounds were studied, and the best properties were found in the N,N-dimethyl homologue (2,5-dimethoxy-N,N-dimethyl-4-iodoamphetamine). This compound was successfully synthesized in a ...
The radioiodine-labeled amines currently available as brain-imaging agents, based on our previous work and that of others, are prepared either by exchange labeling or by direct iodination of a protected intermediate. The intrinsic slowness of these processes limits their potential for use with the positron-emitting 122I, as it has a half-life of only 3.6 min. This isotope has advantages of a low dose to the patient and availability from a generator containing the parent 20-h 122Xe. To develop a radiopharmaceutical in which 122I could be utilized, we prepared a number of secondary and tertiary amines (maintaining the 2,5-dimethoxy substitution pattern which allows direct iodination at the 4-position) with 131I. The organ distributions of these compounds were studied, and the best properties were found in the N,N-dimethyl homologue (2,5-dimethoxy-N,N-dimethyl-4-iodoamphetamine). This compound was successfully synthesized in a ...
Appendices to this summary consist of twelve individual status reports that will be available through the National Technical Information Service (NTIS) in the United States and of course limited copies will be available through NATO. The twelve report titles which are appendices to the summary are: (A) Status Report on the Limestone/Sludge Flue Gas Desulfurization Process; (B) Status Report on the Lime/Sludge Flue Gas Desulfurization Process; (C) Status Report on the Double Alkali/Sludge Flue Gas Desulfurization Process; (D) Status Report on the Sea Water Scrubbing Flue Gas Desulfurization Process; (E) Status Report on the Limestone/Gypsum Flue Gas Desulfurization Process; (F) Status Report on the Lime/Gypsum Flue Gas Desulfurization Process; (G) Status Report on the Double Alkali/Gypsum Flue Gas Desulfurization Process; (H) Status Report on Flue Gas Desulfurization by Scrubbing with Dilute Sulfuric Acid; (I) Status Report ...
Endoluminal vascular prostheses that can be implanted by percutaneous routes represent the most recent development in vascular interventional radiology. Various commercially available types of prosthesis are presented and the construction principles and applications are described. At present secure indications for the implantation of endoluminal prostheses are limited to the elimination of aneurysms and arteriovenous fistulae of the large vessels near the trunk in sections that do not cross a joint. The wide use in peripheral occlusive diseases cannot yet be recommended because confirmed data are not available. (orig.) [German] Endoluminale Gefaessprothesen, die perkutan implantierbar sind, stellen die juengste Entwicklung in der vaskulaeren interventionellen Radiologie dar. Verschiedene kommerziell erhaeltliche Prothesentypen werden vorgestellt, ihr Konstruktionsprinzip und ihre Applikation erlaeutert. Die gesicherten ...
The study of chemoattractant receptors on human monocytes had been limited by the lack of a radioligand suitable for use with the small numbers of cells routinely available from human donors. A new synthetic oligopeptide radioligand f(/sup 35/S)Met-leu-phe, with a higher specific radioactivity than was available with the tritiated compound, was used to characterize a chemoattractant receptor on freshly isolated human blood monocytes. These cells bind f(/sup 35/)met-leu-phe with a dissociation constant (KD) of 30.2 +/- 5.6 nM and contain 84,000 +/- 11,300 receptors per cell. f(/sup 35/)met-leu-phe does not bind specifically to blood lymphocytes. The specificity of the oligopeptide receptor on monocytes is indistinguishable from the oligopeptide chemoattractant receptor on human polymorphonuclear leukocytes. Using f(/sup 35/)met-leu-phe, it will now be feasible to study the chemotactic peptide receptor on small numbers of ...
Nuclear steam generator tubes have become flawed in ways that challenge conventional eddy current probes. In response to the shortcomings of conventional probes, array probes have been developed to improve measurement capabilities. However, the commercially available array probes have exhibited several weaknesses that offset the advantages and limit the applications in steam generator inspections. A primary weakness is the relatively high rate of probe failure coupled with the high unit cost for each probe. This can be costly for a utility in the time lost for probe replacement and increased radiation exposure in addition to the probe costs. Other weaknesses which make array probes undesirable for routine use are: poor mechanical and electrical characteristics; difficulty in operation and calibration; and incomplete coverage of the tube circumference. Several prototype array probes have been built to address the weaknesses of the commercially ...
Jordan is an example of a third world country that is non-oil producing but contains huge reserves of other energy sources such as tar sand, oil shale, and olive cake. Some limited research is available about how to utilize these energy sources in pure form. However, available research does not deal with combinations of these energy sources. This experimental study investigates combinations of these energy forms as potential energy sources in Jordan. The experimental procedure involves characterization of samples by proximate analysis, calorific value determination of different combinations, and a compacting process of the different particles. The best combination, with respect to calorific value, is found to be 20% tar sand, 20% olive cake, and 60% oil shale. Compacting materials either with starch or with heated tar sand up to 110{sup o}C for 1 h indicates a feasible process for handling, packaging, and transporting. ...
According to enactment of reduced dose limit based on ICRP-60, the calculation of Derived Release Limits(DRL) on Wolsung NPPs was carried out. There are two methods of determination on DRL; that is MPC(Maximum Permissible Concentration) method and system analysis method. In order to use the system analysis method, lots of environmental data are necessary and complicated exposure pathway are considered. So we intend to apply MPC method that is sort of simple. In addition the calculated results were compared with derived release limit on Canadian nuclear power plant.
A database has been developed to contain the disposal limits for the E-Area Low Level Waste Facility (ELLWF). This database originates in the form of an EXCEL{copyright} workbook. The pertinent sheets are translated to PDF format using Adobe ACROBAT{copyright}. The PDF version of the database is accessible from the Solid Waste Division web page on SHRINE. In addition to containing the various disposal unit limits, the database also contains hyperlinks to the original references for all limits. It is anticipated that database will be revised each time there is an addition, deletion or revision of any of the ELLWF radionuclide disposal limits.
We briefly report on zero-temperature photoassociation of a Bose-Einstein condensate, focusing on the many-body rate limit for atom-molecule conversion. An upgraded model that explicitly includes spontaneous radiative decay leads to an unanticipated shift in the position of the photoassociation resonance, which affects whether the rate (constant) maximizes or saturates, as well as the limiting value itself. A simple analytical model agrees with numerical experiments, but only for high density. Finally, an explicit comparison with the two-body unitary limit, set by the size of the condensate, finds that the many-body rate limit is generally more strict.
The physics of density limit phenomena in toroidal helical plasmas based on an analytic point model of toroidal plasmas is discussed. The combined mechanism of the transport and radiation loss of energy is analyzed, and the achievable density is derived. A scaling law of the density limit is discussed. The dependence of the critical density on the heating power, magnetic field, plasma size and safety factor in the case of L-mode energy confinement is explained. The dynamic evolution of the plasma energy and radiation loss is discussed. Assuming a simple model of density evolution, of a sudden loss of density if the temperature becomes lower than critical value, then a limit cycle oscillation is shown to occur. A condition that divides the limit cycle oscillation and the complete radiation collapse is discussed. This model seems to explain the density limit oscillation that has been ...
Limiters are nonlinear hybridization techniques that are used to preserve positivity and monotonicity when numerically solving hyperbolic conservation laws. Unfortunately, the original methods suffer from the truncation-error being first-order accurate at all extrema despite the accuracy of the higher-order method. To remedy this problem, higher-order extensions were proposed that relied on elaborate analytic and geometric constructions. Since extremum-preserving limiters are applied only at extrema, additional computational cost is negligible. Therefore, extremum-preserving limiters ensure higher-order spatial accuracy while maintaining simplicity. This report presents higher-order limiting for (i) computing van Leer slopes and (ii) adjusting parabolic profiles. This limiting preserves monotonicity and accuracy at smooth extrema, maintains stability in the presence of ...
This presentation described the geology of the Kootenay, Gething, Gates, Brazeau and Coalspur Formations in the potential gas-bearing coal zones of the Alberta Foothills/Mountains. The future potential of this region for coalbed methane (CBM) exploitation was discussed, based on available data from drilling activity and the results of a recent coal desorption and adsorption study in the Val d'Or seam of the Coalspur formation. The gas content of the 5 coal zones was evaluated and compared with previous CBM exploration in the area. For evaluation purposes, the coal zones were divided into shallow and deep coal zones. The potential gas content of the shallow coal zones is approximately 31 Tcf of CBM. This is considered an inferred, initial, in-place, CBM resource estimate based on limited data. The gas content of deep zones is approximately 99 Tcf of in-place CBM gas. As such, the total ultimate CBM resource is estimated at 130 Tcf. ...
Visual Sample Plan (VSP) is an easy-to-use visual and graphic statistically-based software tool being developed by the Pacific Northwest National Laboratory (PNNL) to help determine the appropriate number and location of environmental samples so that environmental decisions can be made with the required confidence. The VSP software, which is available free at http://dqo.pnl.gov/vsp, is a significant aid in developing probability-based sampling designs (number and location of samples and measurements) using the Data Quality Objectives (DQO) planning process developed by the U.S. Environmental Protection Agency (EPA). VSP also has the capability of conducted statistical analyses to provide descriptive statistical summaries of data sets, to test whether data are normally distributed, and to compute upper confidence limits on means. This report is the latest in a series of reports that document the statistical methods used in VSP [Davidson (2001), ...
Solid oxide fuel cell (SOFC) is a promising source of power generation in terms of conversion efficiency which is higher than the conventional one, as it is not limited by the Carnot efficiency. Theoretically, the SOFC have an efficiency of the order of 60-80 % but it is limited by the number of active side available for the reaction i.e. TPB (triple phase boundary) at the electrode-electrolyte interface which depends on the particle size of the materials employed during the fabrication of SOFC components (i.e. the method employed during the synthesis). Literally, there are several methods used in the syntheses of oxide materials such as conventional solid-state reaction, co-precipitation, hydrothermal rout, sol-gel and Glycine nitrate process (GNP) but among these GNP found to be effective over the other because of homogeneity, phase purity and smaller particle size of final product. In this work, the Nano-crystalline ...
A rigorous solution for the spectrum of a quasioptical cylindrical cavity resonator with a randomly rough side boundary has been obtained. To accomplish this task, we have developed a method for the separation of variables in a wave equation, which enables one, in principle, to rigorously examine any limiting case-from negligibly weak to arbitrarily strong disorder at the resonator boundary. It is shown that the effect of disorder-induced scattering can be properly described in terms of two geometric potentials, specifically, the "amplitude" and the "gradient" potentials, which appear in wave equations in the course of conformal smoothing of the resonator boundaries. The scattering resulting from the gradient potential appears to be dominant, and its impact on the whole spectrum is governed by the unique sharpness parameter ?, the mean tangent of the asperity slope. As opposed to the resonator with bulk disorder, the distribution of nearest-neighbor spacings (NNS) ...
The feasibility of self-expanding nitinol stents for treatment of infragenicular arteries following unsuccessful balloon angioplasty was assessed. Options for lower limb percutaneous revascularization are limited, especially for complex vessel obstruction. Depending on the lesion and the experience of the interventionalist, the failure rate of balloon angioplasty (PTA) ranges between 10 and 40%. Until recently, no self-expanding stent for the use in the infragenicular arteries was available. This is the first report of the results for 18 consecutive patients who received 4F sheath compatible self-expanding nitinol stents following unsuccessful PTA or early restenosis. Twenty-four stents were implanted in 21 lesions for various indications residual stenosis >50% due to heavy calcification, flow-limiting dissection, occluding thrombus resistant to thrombolyis, thrombaspiration, and PTA, and early restenosis after ...
In response to a request from DOE-SR, the current state of knowledge of the reactions between TBP and aqueous nitrate solutions is critically reviewed, and recommendations are made for the safe operation of SRS separations equipment in which this combination of chemicals may be present. The existing limits for evaporation are validated. Guidelines are presented for cases in which general limits do not apply. The rate of reaction between nitric acid and TBP appears to be controlled by the rate of TBP hydrolysis. The hydrolysis reaction produces dibutyl phosphate and n-butanol. The hydrolysis rate is a strong function of temperature, and becomes very fast at temperatures in the range 130{degrees} to 150{degrees}C. The resulting n-butanol is volatile at high temperatures, boiling at 117.5{degrees}C, but is also subject to exothermic oxidation by nitric acid or nitrates. If oxidation occurs before the n-butanol evaporates, the heat of oxidation may ...
This report documents the Mixed Waste Focus Area (MWFA)-sponsored Alternative Technology Workshop held in Salt Lake City, Utah, from January 24--27, 1995. The primary workshop goal was identifying potential applications for emerging technologies within the Options Analysis Team (OAT) ''wise'' configuration. Consistent with the scope of the OAT analysis, the review was limited to the Mixed Low-Level Waste (MLLW) fraction of DOE's mixed waste inventory. The Los Alamos team prepared workshop materials (databases and compilations) to be used as bases for participant review and recommendations. These materials derived from the Mixed Waste Inventory Report (MWIR) data base (May 1994), the Draft Site Treatment Plan (DSTP) data base, and the OAT treatment facility configuration of December 7, 1994. In reviewing workshop results, the reader should note several caveats regarding data limitations. Link-up of the MWIR and DSTP data bases, while ...
This handbook presents information and data for high explosives (HEs) of interest to programs at the Lawrence Livermore National Laboratory (LLNL) and other Department of Energy (DOE) facilities. It is intended to be useful to the scientist or engineer, the novice or expert, who needs to develop a new weapon system, design a physics experiment, or select and/or evaluate an existing explosive. This compilation is limited to production HEs and their components. High explosives are divided into two classes: initial detonating (or primary) and noninitiating (or secondary) explosives. The primary HEs, such as azides and fulminates, are extremely sensitive to ignition by heat, shock, and electrical discharge; ignition leads to high-order detonation of the material - even for milligram quantities. The use of these HEs is therefore limited to squibs and starting materials for low-energy detonators. Because primary explosives have little application at ...
This report presents findings from the first year of a two-year study of interactive efforts involving utilities and non-utility parties (NUPS) working together to prepare plans, develop Demand-Side Management (DSM) programs, or otherwise promote integrated planning and the use of cost-effective DSM measures. Of the ten cases covered in the current study, seven involved the collaborative approach to NUP involvement, which generally is marked by intensive utility-NUP interactions designed to reach consensus on a broad range of important issues; in collaboratives, outside consultants often are provided to enhance the technical capabilities of the NUPS. Another of the cases in this study involved a cooperative arrangement,'' whereby a utility and a NLT worked together in a focused short-term effort to develop a single DSM program. The intense interaction involved in this approach makes it very similar to a collaborative, except that both the scope and the duration of the ...
This report presents findings from the first year of a two-year study of interactive efforts involving utilities and non-utility parties (NUPS) working together to prepare plans, develop Demand-Side Management (DSM) programs, or otherwise promote integrated planning and the use of cost-effective DSM measures. Of the ten cases covered in the current study, seven involved the collaborative approach to NUP involvement, which generally is marked by intensive utility-NUP interactions designed to reach consensus on a broad range of important issues; in collaboratives, outside consultants often are provided to enhance the technical capabilities of the NUPS. Another of the cases in this study involved a ``cooperative arrangement,`` whereby a utility and a NLT worked together in a focused short-term effort to develop a single DSM program. The intense interaction involved in this approach makes it very similar to a collaborative, except that both the scope and the duration of the effort were ...
In the field of reactor and fuel cycle physics, particle transport plays and important role. Neutronic design, operation and evaluation calculations of nuclear system make use of large and powerful computer codes. However, current limitations in terms of computer resources make it necessary to introduce simplifications and approximations in order to keep calculation time and cost within reasonable limits. Two different types of methods are available in these codes. The first one is the deterministic method, which is applicable in most practical cases but requires approximations. The other method is the Monte Carlo method, which does not make these approximations but which generally requires exceedingly long running times. The main motivation of this work is to investigate the possibility of a combined use of the two methods in such a way as to retain their advantages while avoiding their drawbacks. Our work has mainly ...
The environment - external or internal degrees of freedom coupled to the object of interest - can, in effect, monitor some of its observables. As a result, the eigenstates of these observables decohere and behave like classical states. Continuous destruction of superpositions leads to the effective environment-induced superselection (einselection), which is beginning to be recognized as a key step in the transition from quantum to classical. We investigate it here in the context of quantum chaos. I show that the evolution of a chaotic macroscopic system is not just difficult to predict (requiring accuracy exponentially increasing with time) but quickly ceases to be deterministic in principle as a result of the Heisenberg uncertainty (which limits the available resolution). This happens after a time t{sub {Dirac_h}} which is only logarithmic in the Planck constant. For example, various components of the solar system are chaotic, with the ...
To overcome the limitations of conventional bobbin style eddy-current probes, it has become common practice to perform some portion of a steam generator tube inspection program with array coil probes. Typically, eight surface-riding pancake coils are utilized in a probe head, either as eight independent coils (8 x 1) or in a parallel combination of four serially connected coils (4 x 4). The advantages of the array coils are improved sensitivity to intergranular attack (IGA), reduced interference from tube denting, and improved sensitivity to circumferential cracking. The current status of commercially available probes is such that several weaknesses in array coils have limited the widespread application of this technology. Task S 301-6 was conceived to address each of the weaknesses in order to produce a more reliable and cost-effective probe. The emphasis was on reliability, since the cost associated with downtime for a ...
In many applications, the experimenter has limited options about what factor combinations can be chosen for a designed study. Consider a screening study for a production process involving five input factors whose levels have been previously established. The goal of the study is to understand the effect of each factor on the response, a variable that is expensive to measure and results in destruction of the part. From an inventory of available parts with known factor values, we wish to identify a best collection of factor combinations with which to estimate the factor effects. Though the observational nature of the study cannot establish a causal relationship involving the response and the factors, the study can increase understanding of the underlying process. The study can also help determine where investment should be made to control input factors during production that will maximally influence the response. Because the factor combinations ...
In areas where radiation dose monitoring has not been performed, it is essential to use material available in the environment be able to rapidly assess doses to individuals for immediate emergency medical care or for general estimation of the radiological consequences. It was shown that certain types of telephone cards containing microchips have the potential to be used as individual radiation dosimeters in emergency situations to detect doses over 250 mGy by luminescence measurements. In order to understand the dosimetric properties of chip cards, the components obtained from INFINIEON Company at various stages of production were used for luminescence measurements. It is found that the protecting layer used above the chips so called 'globe top' is the main source of radiation induced signal in chip cards. The globe top produced by INFINIEON at that stage is found to contain SiO2 and Epoxy. In order to improve the dosimetric properties of the chip cards, the raw ...
Theoretical assessment on the chromatographic {sup 99m}Tc generator preparation using (n, {gamma}) {sup 99}Mo produced ex-natural molybdenum was carried out. The relationship between the neutron flux for MoO{sub 3} target activation, Mo-content or Mo adsorption capacity of column packing material, {sup 99m}Tc pertechnetate concentration and/or {sup 99m}Tc radioactivity of eluate was established. The reasonably lower limit of neutron flux of reactor and Molybdenum content of column packing material were found out to estimate the production of portable chromatographic generators available for nuclear medicine application. The concentration of {sup 99m}Tc pertechnetate eluate of low {sup 99m}Tc concentration using the column elution technique was also evaluate theoretically and conducted successfully in practice. Three options of {sup 99m}Tc generator using Titanium-Molybdate, Zirconium-Molybdate and Zirconium Oxide as generator column-packing ...
This report documents the concluding efforts at the Engineering Sciences Laboratory of TRW on two specific areas of current research activity within the more general context of proposed lean-burn operation of Otto-cycle-type automotive engines. These areas are: (1) achievement of knock-free performance, both under available fuels and current compression ratios and also under higher-octane fuels (e.g., alcohols) and higher-compression-ratio design (for greater thermal efficiency); and (2) identification of counterstrategies for two-wall (crevice-type) quenching of flame propagation, a phenomenon now widely acknowledged to be the major source of unburned-hydrocarbon emissions exhausted from homogeneous-charge cyclinders. There are certainly other highly active areas of research in Otto-cycle engines, such as turbocharging, ignition devices, and valve design, but the two above-cited topics were the topics of this project.
One approach to validate nuclear power plant (NPP) signals makes use of pattern recognition techniques. This approach often assumes that there is a set of signal prototypes that are continuously compared with the actual sensor signals. These signal prototypes are often computed based on empirical models with little or no knowledge about physical processes. A common problem of all data-based models is their limited ability to make predictions on the basis of available training data. Another problem is related to suboptimal training algorithms. Both of these potential shortcomings with conventional approaches to signal validation and sensor operability validation are successfully resolved by adopting a recently proposed learning paradigm called the support vector machine (SVM). The work presented here is a novel application of SVM for data-based modeling of system state variables in an NPP, integrated with a nonlinear, nonparametric technique ...
An important early step in the assessment of ecological risks at contaminated sites is the screening of chemicals detected on the site to identify those that constitute a potential risk. Part of this screening process is the comparison of measured ambient concentrations to concentrations that are believed to be nonhazardous, termed benchmarks. This article discusses 13 methods by which benchmarks may be derived for aquatic biota and presents benchmarks for 105 chemicals. It then compares them with respect to their sensitivity, availability, magnitude relative to background concentrations, and conceptual bases. This compilation is limited to chemicals that have been detected on the US Department of Energy's Oak Ridge Reservation (ORR) and to benchmarks derived from studies of toxic effects on freshwater organisms. The list of chemicals includes 45 metals and 56 industrial organic chemicals but only four pesticides. Although some individual ...
Superconducting magnetic energy storage (SMES) is an emerging technology with features that are potentially attractive in electric utility applications. This study evaluates the potential for SMES technology in the generation, transmission, distribution, and use of electric energy; the time frame of the assessment is through the year 2030. Comparisons are made with other technology options, including both commercially available and advanced systems such as various peaking generation technologies, transmission stability improvement technologies, and power quality enhancement devices. The methodology used for this study focused on the needs of the market place, the capabilities of S and the characteristics of the competing technologies. There is widespread interest within utilities for the development of SMES technology, but there is no general consensus regarding the most attractive size. Considerable uncertainty exists regarding the eventual costs and benefits of ...
Ionizing radiation, mainly in the form of #gamma#-rays from the radioisotope cobalt 60, is being used increasingly for the inactivation of contaminants in cosmetic and toiletry preparations. The treatment is applied to the product in its final pack, and therefore, it is important to recognize that the properties of the packaging materials could be affected, particularly if high radiation doses are used. The stability of a wide range of materials is discussed. The nature and extent of chemical and physical changes in plastics very much depends on the presence of antioxidants and other additives, and on the environmental conditions during irradiation. Some useful information is available from research into the use of radiation for the preservation of food - many films and laminates have been cleared for use in the United States. The low radiation doses used for the control of contaminants in cosmetic products are quite unlikely to cause changes in packaging materials ...
A new three-dimensional treatment planning system (TPS) based on convolution/superposition algorithms (TMS-Radix from HELAX AB, Uppsala, Sweden) was recently installed at the University Hospital in Lund. The purpose of the present study was to design a quality assurance and acceptance testing programme to meet the specific characteristics of this convolution model. The model is based on parametrization of a non-measurable quantity - the polyenergetic pencil beam. However, the verification of the treatment planning model is still dependent on numerous comparisons of measured depth-doses and dose profiles. The test programme was divided in two basic parts: (i) model implementation and beam data consistency and (ii) model performance and limitations in special situations. The first part was scheduled for all photon beam qualities available before they could be used for clinical treatment planning. The second part was performed for selected ...
A technical review is presented of experiment activities and state of knowledge on air-borne, radiation source terms resulting from explosive sabotage attacks on spent reactor fuel subassemblies in shielded casks. Current assumptions about the behavior of irradiated fuel are largely based on a limited number of experimental results involving unirradiated, depleted uranium dioxide ''surrogate'' fuel. The behavior of irradiated nuclear fuel subjected to explosive conditions could be different from the behavior of the surrogate fuel, depending on the assumptions made by the evaluator. Available data indicate that these potential differences could result in errors, and possible orders-of-magnitude overestimates of aerosol dispersion and potential health effects from sabotage attacks. Furthermore, it is suggested that the current assumptions used in arriving at existing regulations for the transportation and ...
The objective of the Coastal Habitat Injury Assessment study was to document and quantify injury to biota of the shallow subtidal, intertidal, and supratidal zones throughout the shoreline affected by oil or cleanup activity associated with the Exxon Valdez oil spill. The results of these studies were to be used to support the Trustee`s Type B Natural Resource Damage Assessment under the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA). A probability based stratified random sample of shoreline segments was selected with probability proportional to size from each of 15 strata (5 habitat types crossed with 3 levels of potential oil impact) based on those data available in July, 1989. Three study regions were used: Prince William Sound, Cook Inlet/Kenai Peninsula, and Kodiak/Alaska Peninsula. A Geographic Information System was utilized to combine oiling and habitat data and to select the probability sample of study sites. ...
Wildland fire suppression personnel employed by the CDF do not currently have the equipment to protect themselves from the short-term acute affects of smoke from wildland fires. In addition, no regulations exist that specify appropriate respiratory protection and the current air-purifying respirator technology and carbon monoxide monitoring has not been adapted to fit wildland fire suppression requirements. This three-year limited study evaluated the ability of wildland fire fighters to perform their normal job function while wearing full-face air-purifying respirators. In the first two years of this study we designed, developed and field tested a prototype ``smart`` air-purifying respirator which incorporated a real-time carbon monoxide monitor into a commercial full-face respirator.` Data on carbon monoxide exposure while fighting wildland fires was collected. During the third year of this study we evaluated eight different commercially ...
Many data mining tools cannot be used directly to analyze the complex sets of relations which are found in large database systems. In our experience, data miners rely on a well-defined data model, or the knowledge of a data expert, to isolate and extract candidate data sets prior to mining the data. For many databases, typically large legacy systems, a reliable data model is often unavailable and access to the data expert can be limited. In this paper we use reverse engineering techniques to infer a model of the database. Reverse engineering a database can be seen as knowledge discovery in its own right and the resulting data model may be made available to data mining tools as background knowledge. In addition, minable data sets can be produced from the inferred data model and analyzed using conventional data mining tools. Our approach reduces the data miner`s reliance on a well-defined data model and the data expert.
A technical committee reported on: (1) proposed water quality objectives for the San Joaquin River Basin; (2) proposed effluent limitations for agricultural drainage discharges in the basin to achieve these objectives; and (3) a proposal to regulate these discharges. The costs and economic impact of achieving various alternative water quality objectives were also evaluated. The information gathered by the technical committee will be used by the Regional Board along with other information in their review of the San Joaquin River Basin Water Quality Control Plan and their actions to regulate agricultural drainage in the San Joaquin Valley. The results of the Technical Committee's efforts as reported in Regulation of Agricultural Drainage to the San Joaquin River, August 1987. Based on the available information, the improvement in water quality resulting from implementation of the interim selenium objective and long-term objectives for ...
The large number of forms and types of pump equipment in common use have different purposes and varying application requirements. This text has been prepared to bring together necessary information for those who are required to select and apply pumps in systems for all kinds of fluids and purposes. It is not a design manual. It limits the discussion of design to those factors which are necessary for an understanding of pump operation. The book contains not only descriptive information of many types of designs, but also the effect of design variation on use, economy, and reliability. Systems, an integral part of application, are discussed, so that the user of such equipment may properly select and install machines to reliably and economically satisfy his requirements. Reading of appropriate sections of the text will indicate possible problems to be avoided, and economics to be gained. The engineering design of pumps is a science; their proper application is an art. ...
Positive identification of Martian pseudocraters would be a strong indication of past occurrence of ice at or near the surface of Mars. The basis for suggesting that small cones on Mars are pseudocraters includes: (1) small size, (2) abundant but patchy distribution on what appear to be volcanic plains, (3) presence of other features suggestive of surface or subsurface ice, (4) morphological similarities to Icelandic pseudocraters, and (5) the similarity in distribution of crater/cone diameter ratios to Icelandic pseudocraters. This last morphometric parameter may be the most important, since other possible small terrestrial volcanic analogs have very different crater/cone diameter ratio distributions. In a survey of the available high resolution Viking Orbiter imagery, abundant fields of possible pseudocraters were found. However, only a small fraction of the plains forming units imaged at high resolution were found to contain the small cones. This low discovery ...
The Executive Body adopted the Protocol on Heavy Metals on 24 June 1998 in Aarhus (Denmark). It targets three particularly harmful metals: cadmium, lead and mercury. According to one of the basic obligations, parties will have to reduce their emissions for these three metals below their levels in 1990. The Protocol aims to cut emissions from industrial sources, combustion process and waste incineration. It lays down strighten limit values for emissions from stationary sources and suggests best available techniques (BAT) for these sources, such as special filters or scrubbers for combustion sources or mercury-free processes. The Protocol requires parties to phase out leaded petrol. It also introduces measures to lower heavy metal emissions from other products, such as mercury in batteries, and proposes the introduciton of management measures for other mercury-containing products, such as electrical componets (thermostats, switches), measuring ...
The PSDE/SAT-2 multimission satellite designed to offer a flight opportunity to different experimental communication payloads and verify the feasibility of advanced space technologies is described. It was conceived for expriment in the framework of the European DRS (Data Relay Satellite) program thus providing intersatellite and interorbit communication links, but also experimental and preoperative services. Payloads include optical communication single access payload (LSA); S-Band single access payload; S-Band multiple access payload; land mobile experimental payload; navigation payload; 40/50 GHz communication payload; and millimeter wave propagation payload. The orbital slot and interference analysis identified a limited number of orbital positions for the mission interleaved between Eutelsat satellites (i.e., 14 deg 30 min E and 17 deg 30 min E). A coordination is required in Ku-Band with Eutelsat satellites and in Ka-Band with ITALSAT (Italy) and TOR-12 (USSR) ...
This document reviews the status of the knowledge on the oxidation of fuels below 400 deg C, in all its forms, including fuel rods, by examining the consequences of this reaction on the strength or ruin of the fuel rods during dry storage in air for a hundred years. The data available in the scientific literature, and the data acquired by CEA, are abundant on irradiated powders and pellets, but sparser for irradiated fuel fragments and for rods or sections of fuel rods. A bibliographic review is made to identify the morphological and structural changes, as well as the kinetic laws. An analysis and a summary is made with a concern to evaluate the risks of rod ruin by oxidation. The final section, in a few pages, addresses the essential lessons from this study. It presents: first, a summary of the main results of this review and its analysis, recommendations and remedies for storage; proposed research guidelines as well as precise topics, in order to fill out our ...
Government agencies responsible for protecting the public from the adverse effects of toxic chemicals must set priorities for research, regulatory action, protocol testing, and monitoring due to the vast number of toxic chemicals and the limited resources available to these agencies. The National Institute for Occupational Safety and Health (NIOSH) must set priorities for research on hazards encountered in the workplace. Priorities are also utilized by NIOSH in preparing criteria for recommended occupational standards which are forwarded to the Occupational Safety and Health Administration (OSHA), U.S. Department of Labor, for possible promulgation. For various reasons, including rapidly changing conditions in the American workplace, NIOSH has instituted a revised priorities program. In the future, NIOSH research and recommended standards activities will focus not only on individual chemicals, but also on industries, occupations, chemical ...
In Romania, the nuclear power is an element of sustainable development, being competitive, efficient and viable in the market economy. Fuel supply is ensured as nuclear fuel is manufactured in the country out of local uranium resources available in Romania. As for the environmental protection, it is known that, unlike the thermal power plants, the nuclear power plants do not release sulfur and nitrogen oxides, carbon dioxide and do not generate slag and ashes. The operation of nuclear power units does not release pollutants and, accordingly, these stations can contribute to the limitation and the abatement of environmental pollution. After seven years of Cernavoda NPP Unit 1 operation, a facility for storing low and medium level nuclear fuel wastes was built at the plant site as well as an intermediate dry storage for spent nuclear fuel whose first modules were commissioned in July 2003. They shall provide safe storage conditions for nuclear ...
In principle four different methods (ultrasound, microwaves, {gamma}-radiation and x-rays) are available for the non-destructive testing of refractories. Three of these methods, i.e. ultrasound, microwaves and {gamma}-radiation, are in use by different producers of AZS materials to carry out the quality control of their products. This paper will compare the three methods on the basis of the physical properties, present the existing devices, and show the advantages as well as the limits of the different methods. {gamma}-radiography, the oldest method in use, has one main disadvantage, which is the requirement of protection against radioactive radiation. Furthermore, while cracks and cavities can be detected with this method, structural changes can not be monitored. Therefore, the ultrasonic method was developed that allows to detect variations of porosity and grain size as well as cracks and voids when the ultrasonic parameters are tuned as well ...
Infrainguinal peripheral occlusive disease is increasingly being treated by endovascular techniques. Bare metal stainless steel, self-expanding nitinol stents, drug-eluting and covered stents (stent grafts) are becoming increasingly more important adjuncts to percutaneous translumninal angioplasty in the treatment of peripheral artery disease. In this article the available evidence supporting the use of stents in the femoropopliteal and tibial arteries will be described as well as their limitations. Future stent developments will also be discussed. (orig.) [German] Die endovaskulaere Therapie spielt bei der Therapie der peripheren arteriellen Verschlusskrankheit (PAVK) eine wichtige Rolle. Unbeschichtete ballonexpandierbare Stahlstents, selbstexpandierende Nitinolstents sowie medikamentenbeschichtete und ''covered stents'' (Stentgrafts) haben eine zunehmende Bedeutung als Zusatztherapie zusammen mit der ...
Under the auspices of the DOE and private industry, considerable progress has been made in: preparation of coal-water fuels; combustion of low-ash coal-based fuel forms; processes to provide deeply-cleaned coal. Developments in advanced beneficiation of coal to meet stringent requirements for low ash and low sulfur can be anticipated to further complicate the problem areas associated with this product. This is attributable to the beneficiated coal being procured in very fine particles with high surface areas, modified surface characteristics, reduced particle size distribution range, and high inherent moisture. Experience in the storage, handling, and transport of highly beneficiated coal has been limited. This is understandable, as quantities of such product are only now becoming available in meaningful quantities. During this reporting period the authors have: developed a suite of empirical tests covering water retention, rewetting, mull ...
The energy recovery scheme at Mucking Marshes landfill site, operated by Cory Environmental Limited, has been in operation since October 1991. Using landfill gas abstracted from the site, a gas turbine generates up to 3.2 MW net electric power for export. Operation and performance of the scheme has been monitored over the period January 1995 to August 1996. Overall performance since the first use of the turbine has also been studied, and has shown reliable and profitable operation. The capital cost of the gas turbine and gas compressor plant was approximately 1.8 million. Actual gas collection wells, pipework, pumping and monitoring facilities, while essential to the scheme, are considered part of the gas control equipment needed for the landfill site. Based on a notional electricity selling price of 4p/kWh, the current annual income from exported power is 550,000. This would be substantially increased by increasing the running time and power output of the turbine. ...
Endoreduplication represents a cell cycle variant during which multiple rounds of DNA replication occur without subsequent chromosome separation and cytokinesis, resulting into a cellular increase of the DNA content. Although the DNA ploidy level of cells is controlled by external stimuli such as light, currently limited knowledge is available on how environmental signals regulate the endoreduplication cycle at the molecular level. Previously, we have demonstrated that the conversion from the mitotic cell cycle into an endoreduplication cycle is mediated by the atypical E2F transcription factor DEL1 that operates as a repressor of endocycle onset. Here, we identified DEL1 as a transcriptional target of the classical E2Fb and E2Fc transcription factors that antagonistically control DEL1 transcript levels through competition for a single E2F cis-acting binding site. Correspondingly with the reported opposite effect of light on the E2Fb and E2Fc ...
Computer programs have been written to allow the analysis of different types of eddy-current probes and their performance under different steam generator test conditions. The probe types include the differential bobbin probe, the absolute bobbin probe, the pancake probe and the reflection probe. The generator test conditions include tube supports, copper deposits, magnetite deposits, denting, wastage, pitting, cracking and IGA. These studies are based mostly on computed values, with the limited number of test specimens available used to verify the computed results. The instrument readings were computed for a complete matrix of the different test conditions, and then the test conditions determined as a function of the readings by a least-squares technique. A comparison was made of the errors in fit and instrument drift for the different probe types. The computations of the change in instrument reading due to the defects have led to an ...
Bulk monomer MMA was impregnated into simul, a fuel wood of Bangladesh, under vacuum and under normal temperature and pressure conditions in order to compare the mode of impregnation and its effect on various characteristic parameters of wood plastic composites. Methanol (MeOH) was used as the swelling solvent with methylmethacrylate (MMA) at MMA: MeOH = 70:30, v/v. Impregnation of the bulk monomer was very high under vacuum compared to that at normal condition; but the difference of grafting of MMA to the wood cellulose under these two impregnating conditions was much lower as compared to that of the uptakes of impregnating solution MMA + MeOH under these two modes of impregnation. Incorporation of additives to MMA + MeOH has substantially enhanced grafting, tensile strength, bending strength and compression strength of the composite to such an extent that there is virtually very little difference between vacuum impregnation and normal impregnation. Considering the ...
Nickel cadmium batteries differ greatly in their mechanical design and construction of the electrodes. Using available electrode constructions, batteries are designed which meet the requirements of specific applications and offer optimum performance. Pocket- and tubular cells are basically developed with the technology of the year 1895. Since then some improvements with todays technology have been made. The sintered cells use the technology of the 1930's and they are still limited to high power application. With this knowledge and the technology of today the fiber-structured nickel electrode (FNC) was developed at DAUG laboratory, a subsidiary company of Mercedes-Benz and Volkswagen. After ten years of experience in light weight prototype batteries for electric vehicles (1-2), the system was brought into production by a new company, DAUG-HOPPECKE. Characteristics of fiber electrodes: thickness and size can be easily changed; pure active ...
Free-electron lasers as scientific instruments are reviewed. The present status and future prospects are delineated with attention drawn to the size, complexity, availability, and performance capability of this new tool. The Free-Electron Laser (FEL) was proposed by John Madey in 1970 (1), although earlier work, relevant to the concept, had been performed by Motz (2) and by Phillips (3). Experimental demonstration was achieved by Madey, et. al. in 1975 and 1976 (4). Since that time, FELs of diverse configurations have been operated at several laboratories around the world. At present, FEL development is focused in two directions: in constructing reliable FELs for scientific research and in extending FEL capability to vacuum ultra-violet (VUV) and even shorter wavelengths. In this article we shall only very briefly review the principles of an FEL, putting emphasis on those aspects that limit performance, after which we shall discuss the ...
Oil and gas companies operate in many countries around the world. Their exploration and production (E&P) operations generate many kinds of waste that must be carefully and appropriately managed. Some of these wastes are inherently part of the E&P process; examples are drilling wastes and produced water. Other wastes are generic industrial wastes that are not unique to E&P activities, such as painting wastes and scrap metal. Still other wastes are associated with the presence of workers at the site; these include trash, food waste, and laundry wash water. In some host countries, mature environmental regulatory programs are in place that provide for various waste management options on the basis of the characteristics of the wastes and the environmental settings of the sites. In other countries, the waste management requirements and authorized options are stringent, even though the infrastructure to meet the requirements may not be available ...
Recent modifications to the EQ3/6 geochemical modeling software package provide for the use of Pitzer's equations to calculate the activity coefficients of aqueous species and the activity of water. These changes extend the range of solute concentrations over which the codes can be used to dependably calculate equilibria in geochemical systems, and permit the inclusion of ion pairs, complexes, and undissociated acids and bases as explicit component species in the Pitzer model. Comparisons of calculations made by the EQ3NR and EQ6 compuer codes with experimental data confirm that the modifications not only allow the codes to accurately evaluate activity coefficients in concentrated solutions, but also permit prediction of solubility limits of evaporite minerals in brines at 25/sup 0/C and elevated temperatures. Calculations for a few salts can be made at temperatures up to approx. 300/sup 0/C, but the temperature range for most electrolytes is constrained ...
The evolution of the technology of waste combustion, energy recovery and flue gas treatment allows to redefine the role of the incineration plant as a basic component of integrated waste management systems. Starting with an overview of the evaluation of emission limits and of the new Best Available Techniques (BAT) approach, strongly recommended by the European Union, the paper reports an overview of the stack emission concentrations measured in recent plants in Italy compared to older ones, with special attention to the dioxin issue. Concerning this topic, it is demonstrated that BAT-equipped plants can act as actual dioxin destroyer rather than producers, even when all the fluxes released in the environment (gaseous, solid and liquid residues) are taken into account. The second part of the paper deals with the evolution of the flue gas control technologies of the last 20 years, pointing out the major trends and the future perspectives for ...
Focus ion beam (FIB) technology is a commonly used tool for integrated circuit device modification, failure analysis, and a variety of other applications. However, limited reliability data of FIB altered circuit is available. This study describes the electromigration mechanism of FIB-altered Al(Cu-Si)/Ti-layered metal lines. The electromigration failures encountered resulted in Al voids at the anode end of FIB-deposited W and Al{sub 2}Cu precipitates at the cathode end. A higher frequency of Al extrusions was also observed on samples stressed at higher temperatures. These observations indicated that FIB-W was an effective blocking boundary for Al and Cu, and confirmed that Cu does electromigrate before Al. The electromigration mechanism of the FIB-altered line closely resembles the published results from two-level Al/W-line/stud interconnect studies. An activation energy of 0.66 eV, with a current exponent of 1.9 and a lognormal sigma of 0.55, ...
Electrical power is generated by steam turbines (steam being produced by coal, oil, gas or nuclear reactors), hydro units, gas turbines, internal combustion engines, jet engines, and pumped storage plants. Nuclear Power Plants generate only 15% of the total electrical power in the US. Nuclear Power Plants being cheaper to run are generally base loaded. The pumped-storage and gas turbine plants have ideal characteristics for peaking duty. In the pumping mode, pumped storage plants are used to provide additional system load and in the generating mode, they supply reactive power during peak load demands. Gas turbine plants have higher running costs, but are used as peaking units with a fast start capability. Fossil power plants need a minimum of 1 hour to stabilize expansion in the boiler and turbine generator. Due to a more competitive power supply market due to deregulation, most of the utilizes plan generation only for the next three years. This paper discusses the generation control, ...
Benthic invertebrates can uptake metals through diffusion of free ion solutes, or ingestion of sediment-bound forms. This study investigated the efficacy of the metal chelating resin SIR 300TM in adsorbing porewater metals and isolating pathways of metal exposure. A field experiment (Botany Bay, Sydney, Australia) and a laboratory toxicity test each manipulated the availability of porewater metals within contaminated and uncontaminated sediments. It was predicted that within contaminated sediments, the resin would adsorb porewater metals and reduce toxicity to invertebrates, but in uncontaminated sediments, the resin would not significantly affect these variables. Whereas in the laboratory, the resin produced the predicted results, in the field the resin increased porewater metal concentrations of contaminated sediments for at least 34 days and decreased abundances of four macroinvertebrate groups, and richness in all sediments. These contrasting findings highlight ...
Inco Ltd., a primary producer of nickel and an important producer of copper, cobalt, precious metals and sulphur products, initiated a project in 1997 to conduct eco-profiles of its worldwide metal production in an effort to improve its internal processing, marketing and environmental management. The study made it possible to recognize some internal and external benefits including the opportunity to gain operating efficiencies and improved process/product design, the development of better environmental performance indicators to guide decision making, and the availability of comprehensive product related environmental data to meet the informational needs of customers, designers, engineers and governments. This paper described the life cycle assessment (LCA) process used by Inco to conduct the study. A life cycle inventory (LCI) was used to quantitatively calculate resource requirements and environmental burdens associated with a product system over the life cycle of ...
In the development of the specific mathematical modeling for heavy and ultra heavy petroleum fractions in a molecular distiller is very important the definition of physical and chemical parameters as density and specific heat of the mixture, the enthalpy of vaporization, among others, since they are used in the energy balance. Information on these properties and their variation with temperature are found in the open literature for mixture with few components (simple mixtures). However, for multicomponent solutions consisting of complex mixtures such as oil and its heavy and ultraheavy fractions, available data are few, or are limited to low temperatures. The specific heat is an important property in the energy balance. This property can be measured by Differential Scanning Calorimetry (DSC), which gives results with great sensitivity and accuracy. This paper presents the variation of specific heat with the temperature of ultra-heavy oil ...
The Department of Energy (DOE) policy requires that all activities be conducted in a manner that protects the safety of the public and provides a safe and healthful workplace for employees. DOE has also prescribed that all personnel be protected in any explosives operation undertaken. The level of safety provided shall be at least equivalent to that of the best industrial practice. The risk of death or serious injury shall be limited to the lowest practicable minimum. DOE and contractors shall continually review their explosives operations with the aim of achieving further refinements and improvements in safety practices and protective features. This manual describes the Department's explosive safety requirements applicable to operations involving the development, testing, handling, and processing of explosives or assemblies containing explosives. It is intended to reflect the state-of-the-art in explosives safety. In addition, it is essential that ...
Based on wind tunnel experiments, theoretical considerations and measurements the dispersion model CAR (Calculation of Air pollution from Road traffic) has been developed for determining air quality in city streets. CAR International is a simple parameterized model using readily available input data and calculating annual percentile values and average concentrations close to streets (at the kerb side) for non-reactive air pollutants and NO{sub 2}. Originally the model was set up for the Dutch situation (traffic, meteorology) with a system of fixed parameters. In order to extend its application to other countries the program has been made more flexible and user friendly. User defined system data can now be changed interactively, such as emission factors of passenger cars and trucks, fraction of directly emitted NO{sub 2}, city and regional background concentration, and average regional wind speed. The accuracy of the model has proved to be good and is within the ...
For many decades, the oil shale resources of the western United States have been considered possible contributors to the Nation's liquid fuel supply. This volume reviews several paths to development of these resources and the likely consequences of following these paths. A chapter providing background information about the nature of oil shale is followed by an evaluation of technologies for recovery of shale oil. The economics and finances of establishing an industry of various sizes are analyzed. The fact that much of the best shale is located on Federal land is examined in light of the desire to increase use of the resources. The consequences of shale development in terms of impact on the physical and social environments, and a discussion of the availability of water complete the report. Policy options addressing barriers that could hinder the establishment of the industry are presented. These options, designed primarily for Congressional consideration, ...
The objective of this project is to identify feasible Louisiana-grown biomass crops and residues, to combine these with technically and economically feasible conversion processes, and to provide integrated biomass energy production systems in Louisiana. Among the recommended integrated systems are: cotton gin trash and rice hull processing residues used for either direct combustion or methane or ethanol production. Steam generation via direct combustion is recommended. Hardwood chips are economically feasible despite considerable price and supply instability, while high sugar or starch content crops are easily converted to ethanol but limited by price. Possible breakthroughs in biomass production or in the hydrolysis of starch or cellulose substrates may decrease processing costs. Recommended areas for future study dealing with production include: (1) increase biomass availability and density; (2) increase harvesting, transportation and storage ...
This article, published in issue 80 of 'l'ACROnique du nucleaire', aims to retrace the early steps in the consideration of the possibility of a nuclear accident in France, with the inclusion of 'non-institutional' participants and applying the lessons learned in Belarus in the contaminated territories around the Chernobyl nuclear power plant. After a review of the origin of the involvement of the Association pour le Controle de la Radioactivite dans l'Ouest (ACRO) in addressing post-accident issues alongside the populations living in an environment polluted by radioactivity, it discusses, from the critical viewpoint of an NGO, the context and the working method adopted for this examination. This is followed by some key elements of the programme and unresolved questions about the available body of knowledge which motivates research and about the method adopted for the work. The conclusion, moderately optimistic, ...
Many Pacific Basin countries rely on oil for electricity production. Alternative fuel sources such as coal, which is available in the Pacific Basin, can help mitigate adverse impacts of sudden price increases or supply disruptions. Coal combustion produces solid and potentially hazardous wastes of concern to environmental regulators and utility managers. This paper identifies issues associated with managing coal combustion wastes in the Pacific Basin, using the state of Hawaii as a case study. Hawaii is typical of many Pacific Basin locations in that it depends on oil, has limited sites, for waste management operations, and is subject to domestic and international waste management regulations. The paper discusses coal-fired utility wastes, environmental impacts of coal combustion waste disposal, and regulatory requirements that impact coal waste management. From this baseline, potential on- and off-island options for coal waste management are ...
The object of this research is the evaluation of the performance of ultra high speed relays (UHSR's) used for protection of a-c transmission lines. For purposes of this report, these are relays whose response time is less than a quarter of a cycle of the 60 Hz wave (i.e. 4.167 ms.). To identify relaying schemes that may comply with this definition, a literature survey was undertaken. The selected relays were studied in detail and modeled on a digital computer. A theoretical description of these relays is presented. Records of real transient data as well as of simulated data were used as input to the digital models of relays. The real data were recorded by means of monitoring stations connected to the Florida Power and Light Company transmission lines. The simulated data were obtained by modeling the relevant parts of the utility's transmission system using a University of British Columbia simplified version of the well known Electromagnetic Transients Program of the ...
In an HTR plant high temperature components of Alloy 800 materials are subjected to temperatures from about 550 to 850degC in the long term; higher temperatures may occur in the short term. Thus the creep and stress-rupture parameters govern the design of these components. Since in recent years the scope of experimental data available for Alloy 800 materials has considerably increased, a new evaluation of the creep and creep-rupture properties was performed using a data bank computer. The relationships between the characteristics of the creep and creep-rupture behaviour and the metallurgical parameters were investigated by multilinear regression analyses. On the basis of the results of these analyses and after discussion in material expert committees new material specifications were determined for different types of Alloy 800. They were included into the draft standards DIN 17459 and DIN 17460 under the material standard nos. 1.4958, 1.4958 Rk and 1.4959. Besides ...
In an HTR plant high temperature components of Alloy 800 materials are subjected to temperatures from about 550 to 850degC in the long term; higher temperatures may occur in the short term. Thus the creep and stress-rupture parameters govern the design of these components. Since in recent years the scope of experimental data available for Alloy 800 materials has considerably increased, a new evaluation of the creep and creep-rupture properties was performed using a data bank computer. The relationships between the characteristics of the creep and creep-rupture behaviour and the metallurgical parameters were investigated by multilinear regression analyses. On the basis of the results of these analyses and after discussion in material expert committees new material specifications were determined for different types of Alloy 800. They were included into the draft standards DIN 17459 and DIN 17460 under the material standard nos. 1.4958, 1.4958 Rk and 1.4959. Besides ...
For a reliable design against fatigue failure of high-temperature components of different types of the heat resistant material Alloy 800, verified parameters of the low-cycle fatigue (LCF) behaviour are required. These parameters were obtained by a scatterband evaluation of the results of low-cycle fatigue tests, using a computerized data bank which includes all available actual data sets. The results of the evaluation are presented as mean fatigue curves with the upper and lower boundary limits of the scatterbands. For the type Alloy 800 in the recrystallization annealed condition, the results cover a temperature range from 20 to 750deg C; for the solution annealed types they cover a temperature range from 20 to 950deg C. Specimens tested in HTR helium at high temperatures had longer lives than specimens tested in air. This effect was represented quantitatively by the ratio of the total strain ranges from tests in HTR helium and air as a ...
The ability to test advanced fuels and cladding materials under reactor operating conditions in the United States is limited. The Oak Ridge National Laboratory (ORNL) High Flux Isotope Reactor (HFIR) and the newly expanded post-irradiation examination (PIE) capability at the ORNL Irradiated Fuels Examination Laboratory provide unique support for this type of advanced fuel/cladding development effort. The wide breadth of ORNL's fuels and materials research divisions provides all the necessary fuel development capabilities in one location. At ORNL, facilities are available from test fuel fabrication, to irradiation in HFIR under either thermal or fast reactor conditions, to a complete suite of PIEs, and to final product disposal. There are very few locations in the world where this full range of capabilities exists. New testing capabilities at HFIR have been developed that allow testing of advanced nuclear fuels and cladding materials ...
Aim: To systematically review the currently available high quality evidence evaluating treatments for moist desquamation in radiotherapy patients. Design: Systematic literature review. Methods: Electronic databases, websites, reference lists, key journals and conference proceedings were searched. Attempts were also made to uncover unpublished material. Relevant studies proceeded to data extraction and quality assessment. Results: Twenty studies were found; 10 were eligible for inclusion. Although many studies were small, none had unacceptably poor quality. No meta-analysis was undertaken as the studies were not homogenous in their interventions or methods. No convincing evidence for any intervention was found. Conclusion: Despite being recommended by many guidelines (College of Radiographers Summary of Intervention for Acute Radiotherapy Induced Skin Reactions in Cancer Patients (London, 2001); NHS Quality Improvement Scotland Best Practice Statement: Skincare of ...
A new model for fuel spray penetration (location of spray tip) is suggested and validated against available experimental data. Simple analytical expressions for fuel spray penetration are derived in two limiting cases: the initial stage and the two-phase flow regime. At the initial stage, the effects of droplet drag and entrainment of air are accounted for. In the case of the two-phase flow, it is assumed that the spray droplets have the same velocities as the entrained air. The characteristic time of droplet break-up in the spray is estimated for both bag and stripping break-up mechanisms. For realistic diesel spray parameters, the droplet break-up takes place almost immediately after the droplets leave the nozzle. This leads to a considerable shortening of the initial stage and a rapid conversion of the flow to the two-phase stage. This allows the analysis to be restricted to the two-phase flow approximation for this type of spray. The ...
Recent changes in the US liability regime for oil pollution damage have intensified a policy debate about environmental liability limits. Economic theory suggests that some type of limit may be needed under certain conditions, and that such a limit should be set so that the marginal social benefit and cost are equal. However, it is unclear how a liability limit may be determined specifically for tanker shipping in US waters. We first examine conditions under which corner solutions (no liability or unlimited liability) are desirable. We then formulate a model to determine a socially optimal liability limit for oil pollution damage in US waters when a non-zero, finite liability limit is desirable. The model captures the tradeoff between less expensive energy supply and more stringent protection of the marine environment. Numerical simulations illustrate the ...
The report details the economic impact of two alternative regulatory options; a Treated Discharge Option and a Zero Discharge Option on facilities that would have to comply with the regulations as part of the reproposal of effluent limitations and standar...
This report estimates the economic and financial effects of compliance with the proposed effluent limitations guidelines and standards for the Centralized Waste Treatment (CWT) industry. The Environmental Protection Agency (EPA) has measured these impacts...
This document is a technical background document for proposed regulations to limit effluent discharges to waters of the United States and introductions of pollutants into publicly owned treatment works from facilities engaged in porcelain enameling. The p...
This section presents background information supporting the development of effluent limitations guidelines and standards for the concentrated aquatic animal production (CAAP) point source category. Section 1.1 presents the legal authority to regulate the ...
This document presents the findings of an extensive study of the ore mining and dressing industry, for the purpose of developing effluent limitations guidelines for existing point sources and standards for performance new sources, to implement Sections 30...
This cost-effectiveness analysis supports the proposed effluent limitations guidelines and standards for the Metal Products and Machinery Industry (MP and M) Phase I Industry. The report assesses the cost-effectiveness of five regulatory options for indir...
This analysis, submitted in support of proposed effluent limitations guidelines and standards for the centralized waste treatment (CWT) industry, investigates the cost-effectiveness of 24 regulatory options, representing all possible combinations of nine ...
Evaluation of the tolerance limits of X-ray image density accepted by the radiologist shows that for different kinds of examinations, deviations of more than 50% from optimal density lead to images which cannot be used diagnostically. Within this range diagnostic accuracy shows a distinct maximum and diminishes to the limits by 20%. These figures are related to differences in the intensifying factor of screens, sensitivity of films, sensitometric parameters of film processing as well as the doses employed with automatic exposure control devices, measured in clinical conditions. Maximum permissible tolerance limits of the whole imaging system and of its constituents are discussed using the Gaussian law of error addition. (author).
Object: To limit the discharge amount of reactor water in a primary system at the time of scram to prevent excessive outflow of reactor water outside the system. Structure: A signal from an upper limit position indicator detects the fact that control rods are completely inserted when the reactor is urgently stopped and the detection signal causes a valve in an outflow line of the discharge water from a control rod driving mechanism to be closed to limit the amount of discharge flown into the scram discharge vessel, thus preventing outflow of reactor water in the primary system after the scram has been initiated. (Kamimura, M.).
We give a general local central limit theorem for the sum of two independent random variables, one of which satisfies a central limit theorem while the other satisfies a local central limit theorem with the same order variance. We apply this result to various quantities arising in stochastic geometry, including: size of the largest component for percolation on a box; number of components, number of edges, or number of isolated points, for random geometric graphs; covered volume for germ-grain coverage models; number of accepted points for finite-input random sequential adsorption; sum of nearest-neighbour distances for a random sample from a continuous multidimensional distribution.
A possible birefringence effect that arises in quantum gravity leads to a frequency-dependent rotation of the polarization angle of linearly polarized emission from distant sources. Here we use the UV/optical polarization data of the afterglows of GRB 020813 and GRB 021004 to constrain this effect. We find an upper limit on the Gambini & Pulin birefringence parameter $| \\eta | <2\\times 10^{-7}$. This limit is of 3 orders better than the previous limits from observations of AGNs and of the Crab pulsar. Much stronger limits may be obtained by the future observation of polarization of the prompt $\\gamma$-rays.
In a reactor environment, the surface of a limiter or wall is primarily determined by the mechanism of erosion and deposition of surface material. It should be possible to use pellet injection to reduce net erosion to zero everywhere if low-Z materials are used for the surface. Erosion rates can, in general, be minimized by large area limiters and high plasma temperatures, which transmit power to the walls with less sputtering. Under ideal steady state conditions the wall surface is dominated by metallurgical effects in the wall.
The purpose of the present work was to establish the flammability limits of hydrogen in air for upward vertical flame propagation at elevated temperatures up to 350 deg and atmospheric pressure in a conventional stainless steel test tube apparatus, and to investigate the extent to which a prolonged exposure (i.e., residence time) of the mixture to elevated temperatures before spark ignition may influence the value of the flammability limits. 9 refs.
The EPA proposed effluent limitations guidelines and standards for the offshore segment of the oil and gas industry on August 26, 1985. On November 26, 1990, and March 13, 1991, the Agency reproposed effluent limitations guidelines and standards for both drilling and production wastes. The report is primarily concerned with the total annualized cost incurred by the offshore oil and gas industry in complying with the regulations.
...2010-10-01 2010-10-01 false Limitation on the creation of new FFRDC's. 35.017-7 Section 35.017-7 ...DEVELOPMENT CONTRACTING 35.017-7 Limitation on the creation of new FFRDC's. Pursuant to 10 U.S.C....
The Ho-Chunk Nation is interested in documenting water-quality conditions in streams adjacent to their Reservation lands in Wisconsin and developing management plans to protect these water resources. The Nation uses these waterways for recreation and as a source for food, and therefore, is dedicated to maintaining and restoring their quality. Ho-Chunk lands encompass more than 10,000 acres ranging primarily over 17 counties in Wisconsin. The study areas for this report include streams adjacent to Ho-Chunk Nation residential lands: Potch-Hah-Chee, Sandpillow, Mission, Bluewing, Chakh Hah Chee, Winnebago Heights, Indian Heights, and Ho-Chunk Village. These residential areas, or housing sites, are located along or near the Middle Branch Embarrass, Black, Lemonweir, and Wisconsin Rivers or their tributaries. Water-quality data were compiled and summarized, and basin maps showing land cover and previous sampling sites are presented. Qualitative assessments of factors that could potentially ...
We present a method for optimising experimental cuts in order to place the strongest constraints (upper limits) on theoretical signal models. The method relies only on signal and background expectations derived from Monte-Carlo simulations, so no bias is introduced by looking at actual data, for instance by setting a limit based on expected signal above the ``last remaining data event.'' After discussing the concept of the ``average upper limit,'' based on the expectation from an ensemble of repeated experiments with no true signal, we show how the best model rejection potential is achieved by optimising the cuts to minimise the ratio of this ``average upper limit'' to the expected signal from the model. As an example, we use this technique to determine the limit sensitivity of kilometre scale neutrino detectors to extra-terrestrial neutrino fluxes from a variety of models, e.g. ...
The phenomenon of the limit of pitting corrosion in direction to positive potentials is studied by potentiokinetic polarization after a jump in the transpassive range and by potentiostatic tests at technical wrought materials and at model alloys of the systems NiCrMo and NiMo in CaCl{sub 2} solution in the concentration range 1 to 9 mol/l chloride at pH-values of 1 to 9 at temperatures of 30 to 110 C. Surface-analytical investigations gives in connection with knowledges from anodic polarization studies directions to the mechanism of the limit of pitting corrosion. Ranges of the limit of pitting corrosion are obtained at materials with a Mo content above 6.5% and contents of chloride of the media above 2 mol/l chloride. Increasing temperatures, increasing contents of chloride and sulfate shift the potential of the limit of pitting corrosion being always above 0.2 V (SCE) at potentiostatic determination ...
Full text: The isotopic assay instrument under development at Pacific Northwest National Laboratory (PNNL) is capable of rapid prescreening to detect small and rare particles containing high concentrations of uranium in a heterogeneous sample. The isotopic measurement concept is based on laser vaporization of solid samples followed by sensitive isotope-specific detection using either uranium atomic fluorescence emission or uranium atomic absorbance. Both isotopes are measured concurrently, following a single ablation laser pulse using two external-cavity violet diode lasers. The simultaneous measurement of both isotopes enables the correlation of the fluorescence and absorbance signals on a shot-to-shot basis. This measurement approach demonstrated negligible channel crosstalk between isotopes. Scanning the heterogeneous samples provides high-resolution imagery of sample isotopic fluorescence and absorbance. Isotopically selective excitation of uranium vapor also was the basis of the ...
Ultra-shallow junction formation in deep submicron Si devices is limited by anomalous diffusion of the dopant, which is related to the release of interstitials from defect clusters formed during the implantation of energetic ions or the subsequent annealing. The work described in this dissertation is concerned with the effects of low energy B ion implantation, especially damage formation, clustering and its annealing. After a review of the stopping and ranges of energetic ions in Si, the formation of implant damage, in particular of point defects, their migration, agglomeration and annihilation, including the involvement of dopant ions, is considered. A description of the Salford ultra low energy implanter is given and the main analysis technique, medium ion energy scattering (MEIS) reviewed. Additional analytical techniques used, such as secondary ion mass spectrometry (SIMS), 4-point probe and cross section transmission microscopy (XTEM) as well as TRIM ...
Parallel imaging and echo sharing techniques have markedly reduced the acquisition times for MRI of large volumes. Dynamic 2 and 3-dimensional data sets of the chest with high temporal resolution (up to 10 images/s with single slice and 2 volume/s) allow an analysis of respiratory motion of the lungs and tumors. Time-resolved 2D series in preselected planes can be used to observe respiratory motion during free breathing or after respiratory commands, e.g. to exclude chest wall invasion by a tumor or for diagnosing impairment of respiratory mechanics. Time-resolved 3D-series (4D-MRI) allow monitoring of the spatial displacement of the lungs and tumors as a whole volume. Present limitations such as an overestimation of tumor size and an underestimation of displacement due to a limited temporal resolution are expected to be overcome with further technical developments. However, 4D-MRI already appears to be the appropriate tool to select patients ...
Information about surface soil moisture conditions is of critical importance to real-world applications such as agricultural production, water resource management, flood prediction, fire prediction, water supply, military mobility, etc.. Near-surface soil moisture is currently available from non-ideal sensor configuration observations, and two missions targeted at measuring near-surface soil moisture with ideal sensor configuration are expected before the end of the decade (the European Space Agency (ESA), Soil Moisture and Ocean Salinity (SMOS) mission, and the National Aeronautics and Space Administration (NASA), Hydrospheric states "Hydros" mission). Though remote sensing can make spatially comprehensive measurements of surface soil moisture, it cannot provide information on the entire land surface hydrologic system, and the measurements represent only a snap shot in time. Alternatively, land surface hydrology process models may be used to predict the temporal ...
The report presents an integrated software system developed at the Norwegian Electric Power Research Institute (EFI), for production scheduling, maintenance handling, network security analysis, inflow forecasting, and load forecasting. The integrated software is being developed with focus on hydro-dominated power supply systems. In specific terms it is expected that application of the software will improve the operational decisions, and make the planning process more effective. The optimal scheduling of hydro resources poses severe computational problems in system operations planning. This necessitates problem decomposition. In the EFI approach, planning is split into three main levels: long-term, mid-term and short-term planning. The long-term planning aims at evaluating the seasonal and pluriannual handling of regional storages in view of firm power supply obligations, inflow statistics, main hydraulic and electric transit limitations, and the ...
Thermoplastic encapsulation has been extensively studied at Brookhaven National Laboratory`s (BNL) Environmental and Waste Technology Center (EWTC) as a waste encapsulation technology applicable to a wide range of waste types including radioactive, hazardous and mixed wastes. Encapsulation involves processing thermoplastic and waste materials into a waste form product by heating and mixing both materials into a homogeneous molten mixture. Cooling of the melt results in a solid monolithic waste form in which contaminants have been completely surrounded by a polymer matrix. Heating and mixing requirements for successful waste encapsulation can be met using proven technologies available in various types of commercial equipment. Processing techniques for thermoplastic materials, such as low density polyethylene (LDPE), are well established within the plastics industry. The majority of commercial polymer processing is accomplished using extruders, mixers or a ...
In Uganda, biomass comprises more than 95 per cent of the total energy supply. Agricultural residues are a major source of energy that can be converted into producer gas in biomass gasifiers. The high poverty levels in Uganda can be attributed in part to the fact that more than 90 per cent of the population does not have access to electricity due to limited and unreliable electricity produced in the country. A circulating fluidized bed (CFB) gasification system was designed in this study in order to generate a system for the effective use of agricultural wastes for energy production. Rice husks were used as the feedstock for a power output of 60 MW. The gasification system was designed using ERGUN CFB software with available theoretical and experimental data. The design comprises a reactor subsystem, air distribution plate, cyclone, air inlet and fuel feeding systems. The reactor is 10 m high and has a fuel flow rate of 8.1 kg/s. The inlet air ...
A 2009 paper considered possibilities for applying a common display suite to various front-line bubble canopy fighters, whereas further research suggests the cost savings, post Milestone C production/deployment, might not be advantageous. The situation for military cargo and tanker aircraft, may offer a different paradigm. The primary objective of Defense acquisition is to acquire quality products that satisfy user needs with measurable improvements to mission capability and operational support, in a timely manner, and at a fair and reasonable price. DODD 5000.01 specifies that all participants in the acquisition system shall recognize the reality of fiscal constraints, viewing cost as an independent variable. DoD Components must therefore plan programs based on realistic projections of the dollars and manpower likely to be available in future years and also identify the total costs of ownership, as well as the major drivers of total ownership costs. In theory, ...
The US Department of Energy (DOE) is now evaluating its facility requirements in support of its cleanup mission at Hanford. One of the early findings is that the 200-Area steam plants, constructed in 1943, will not meet future space heating and process needs. Because the 200 Area will serve as the primary area for waste treatment and long-term storage, a reliable steam supply is a critical element of Hanford operations. This Analysis and Decision Document (ADD) is a preliminary review of the steam supply options available to the DOE. The ADD contains a comprehensive evaluation of the two major acquisition options: line-term versus privatization. It addresses the life-cycle costs associated with each alternative, as well as factors such as contracting requirements and the impact of market, safety, security, and regulatory issues. Specifically, this ADD documents current and future steam requirements for the 200 Area, describes alternatives ...
Over the past 40 years, cavern storage of LPG's, petrochemicals, such as ethylene and propylene, and other petroleum products has increased dramatically. In 1991, the Gas Processors Association (GPA) lists the total U.S. underground storage capacity for LPG's and related products of approximately 519 million barrels (82.5 million cubic meters) in 1,122 separate caverns. Of this total, 70 are hard rock caverns and the remaining 1,052 are caverns in salt deposits. However, along the eastern seaboard of the U.S. and the Pacific northwest, salt deposits are not available and therefore, storage in hard rocks is required. Limited demand and high cost has prevented the construction of hard rock caverns in this country for a number of years. The storage of natural gas in mined caverns may prove technically feasible if the geology of the targeted market area is suitable; and economically feasible if the cost and convenience of service ...
Full text: Full text: The incomplete understanding of the complex mechanisms connected with the interaction between thermal-hydraulic and neutron kinetics still challenges the design and the operation of nuclear reactors and imposes the adoption of conservatism in the evaluation of safety limits. The recent availability of powerful computer and computational techniques together with the continuing increase in operational experience suggests the revisiting of those areas and the identification of design/operation requirements that can be relaxed. So far, almost all of the safety analyses of research reactors have been performed using conservative computational tools such as channel codes but, nowadays, the application of Best-Estimate (BE) methods constitutes a real necessity. The global aim of the current work is an attempt to apply the best-estimate system thermal-hydraulic code Relap5. For this purpose, the generic IAEA research reactor ...
Carbon monoxide can be produced in severe accidents from interaction of ex-vessel molten core with concrete. Depending on the particular core-melt scenario, the type of concrete and geometric factors affecting the interaction, the quantities of carbon monoxide produced can vary widely, up to several volume percent in the containment. Carbon monoxide is a combustible gas. The carbon monoxide thus produced is in addition to the hydrogen produced by metal-water reactions and by radiolysis, and represents a possibly significant contribution to the combustible gas inventory in the containment. Assessment of possible accident loads to containment thus requires knowledge of the combustion properties of both CO and H_2 in the containment atmosphere. Extensive studies have been carried out and are still continuing in the nuclear industry to assess the threat of hydrogen in a severe reactor accident. However the contribution of carbon monoxide to the combustion threat has received less ...
This paper introduces the summary of design guideline (draft) for the limit state design method for foundation structures, and examples of calculations on pile foundations. The limit states were set using the load to transformation curves, and the limit state No. 3 in particular assumed a large earthquake, a state that a foundation is fatally damaged because of rarely acting loads that lead to generation of displacement and loss of stability and functions. Ground survey coefficient, ground resistance coefficient, and ground property coefficient were defined especially as the safety coefficients. With respect to the displacement in the limit state No. 3, a restriction value was set for the plasticity of the foundation. Loads were given considerations of combination of permanent load, variation load, and accidental load, each having been set with a load coefficient. It was decided regarding earthquakes to ...
We report on a promising approach to high-sensitivity anisotropy measurements using a high-finesse cavity locked by optical feedback to a diode laser. We provide a simple and effective way to decouple the weak anisotropy of interest from the inherent mirror's birefringence whose drift may be identified as the key limiting parameter in cavity-based techniques. We demonstrate a shot-noise-limited phase shift resolution previously inaccessible in an optical cavity, readily achieving the state-of-the-art level of 3x10"-"1"3 rad.
We have explored vibrations of a single-degree of freedom oscillator with a magneto-rheological damper subjected to kinematic excitations in a high frequency limit. Using fast and slow scales decoupling procedure we derived an effective damping coefficient in the limit of high frequency excitation. Damping characteristics, as functions of velocity, change considerably especially by terminating the singular non-smoothness points. This effect was more transparent for a larger control parameter which was defined as the product of the excitation amplitude and its frequency.
An improved ion funnel design is disclosed that decreases the axial RF (parasite) fields at the ion funnel exit. This is achieved by addition of one or more compensation electrodes after the conductance limit electrode. Various RF voltage profiles may be applied to the various electrodes minimizing the parasite axial potential wells. The smallest RF aperture that serves as the conductance limiting electrode is further reduced over standard designs. Overall, the ion funnel improves transmission ranges of both low m/z and high m/z ions, reducing RF activation of ions and decreasing the gas load to subsequent differential pumping stages.
In this talk, we explore the feasibility of quantum computation using continuous-variable systems by means of local measurements only. In the first part of the talk, we will identify crucial limitations that arise when starting from Gaussian cluster states. This is done by resorting to a Gaussian projected entangled pair picture as well as to notions of continuous-variable quantum repeater networks. In the second part, we look at instances in which these limitations can be overcome, and how suitable encodings of qubits in oscillators and feasible non-Gaussian resource states give rise to universal schemes for quantum computing.
Fractal dimensional analysis was employed to obtain a quantitative measure of the morphology of polymer networks formed by UV irradiation induced polymerization of photo-reactive mesogenic monomers dissolved in a liquid crystal host medium. The fractal dimensions obtained, may be interpreted by polymer network growth following a percolation-like model for monomer concentrations well below the solubility limit. On passing the solubility limit, the polymerization process changes from a (radical chain) solution polymerization to a dispersion polymerization, with fractal dimensions decreasing and suggesting a cluster-cluster aggregation process for monomer concentrations above the solubility limit, similar to the aggregation of colloidal particles.
Current technical specifications of Wolsong Unit 2,3,4 was analyzed and improvement methods was suggested to develop Improved Standard Technical Specifications(ISTS) of PHWR. The selection criteria of PHWR limiting condition for operation(LCO) was established, then limiting conditions for operationl were selected. The number of current LCOs for Wolsong Units 2,3,4 is 109, and 46 LCOs(42%) were relocated by the selection criteria of PHWR LCO. 63 LCOs which met the selection criteria of PHWR LCO were recomposed to 59 LCOs.
Lead-acid batteries, one of eight types, account for about 70% of annualized control costs facing the battery manufacturing industry as a result of EPA's guidelines. This report is the industry's response. It makes counter recommendations for effluent limitations, discusses selected control technologies and effluent limitations, makes control cost estimates, and provides an economic impact analysis and a benefits effectiveness analysis.
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. Life-cycle studies show that 1 kg ...
[music] Narrator: New treatments can limit the disability caused by a stroke, but you need to know the signs and act in time. Here are the signs to ...
A review is made of some recent developments in the application of the Bohr Hamiltonian to transitional nulcei. The primary concern is to understand the advantages and limitations inherent to the basic model and its many variants. (author).
... to light-light a laser or directed energy weapon would ... space-based components... .the most likely threats are direct ascent anti-satellite weapons; ...
Applications of cutting-edge estimation techniques, such as, but not limited to, sigma-point and particle filters, to spaceflight navigation problems. ...
These include, but are not limited to: stellar winds and outflows, post-main- sequence stellar evolution, binary/multiple star evolution, globular cluster ...
These include, but are not limited to: stellar winds and outflows, post-main- sequence star evolution, binary star evolution, globular cluster structure and ...
The operational limits of the Tower Shielding Reactor-2 (TSR-2) have been revised to account for placing the reactor in a beam shield, which reduces convection cooling during a loss-of-coolant accident (LOCA). A detailed heat transfer analysis was performed to set operating time limits which preclude fuel damage during a LOCA. Since a LOCA is survivable, the pressure boundary need not be safety related, minimizing seismic and inspection requirements. Measurements of reactor component emittance for this analysis revealed that aluminum oxidized in water may have emittance much higher than accepted values, allowing higher operating limits than were originally expected. These limits could be increased further with analytical or hardware improvements. 5 refs., 7 figs.
There is considerable interest in the use of silicon devices as qubits for quantum computing. The existence of nuclear spin in a silicon isotope and the complex band structure of silicon are unfavourable for this application of silicon devices. (viewpoint)
A nonneutral /sup 7/Li/sup +/ ion plasma is described in which ion Langmuir waves are observed for the first time. The properties of these waves near the Brillouin density limit are investigated.
In the revised GCFR Safety Program Plan a quantitative risk limit line has been adopted to establish requirements for the safety related functions and systems. The risk limit line is derived from an interpretation of NRC established licensing requirements, including those for LMFBR's. Multiple barriers to the progression of accident sequences are defined in the form of six Lines of Protection (LOPs). LOPs-1 to 3 are dedicated to accident prevention and represent the normal operating systems, the dedicated safety systems and the inherent design features, respectively. LOPs-4 to 6 are dedicated to the mitigation of core melt accident consequences and include in-vessel accident containment, secondary containment integrity and radiological attenuation, respectively. Cumulative frequency limits and consequence limits are established for each LOP. Design features associated with each LOP are described and the ...
These include, but are not limited to: stellar winds and outflows, post-main- sequence stellar evolution, binary/multiple star evolution, globular cluster structure ...
These include, but are not limited to: stellar winds and outflows, post-main- sequence stellar evolution, binary/multiple star evolution, globular cluster structure ...
Orbit correction is now routinely performed at the few-micron level in the Advanced Photon Source (APS) storage ring. Three diagnostics are presently in use to measure and control both AC and DC orbit motions: broad-band turn-by-turn rf beam position monitors (BPMs), narrow-band switched heterodyne receivers, and photoemission-style x-ray beam position monitors. Each type of diagnostic has its own set of systematic error effects that place limits on the ultimate pointing stability of x-ray beams supplied to users at the APS. Limiting sources of beam motion at present are magnet power supply noise, girder vibration, and thermal timescale vacuum chamber and girder motion. This paper will investigate the present limitations on orbit correction, and will delve into the upgrades necessary to achieve true sub-micron beam stability.
... Environmental Assessment of Proposed Effluent Limitations Guidelines and Standards for the Meat and Poultry Industry Point Source; EPA-821-B-01-008; US ...
Sep 3, 2010 ... These higher-quality deformable mirrors will enable diffraction-limited performance for many space-based optical systems such as space-based ...
discharges. Proposed Stormwater ELG from Construction Sites - EPA has proposed effluent limitations guidelines (ELGs) and new source performance standards (NSPS) to control...
This standard specifies requirements for the flameproofing and the limiting of surface temperature and exhaust emission control of diesel engine systems for use in underground coal mines.
... perform the inspection in the extremely limited space between adjacent blades and at the blade root, miniature eddy current probes were developed ...
airborne separation assistance systems (ASAS) to ... operations should be limited to the outer traffic flow ...... AGARD Meeting on Machine Intelligence in Air ...
North American design codes are now committed to the development of load and resistance factor design (LRFD) for reinforced soil structures including internal stability limit states. Reliability-based analysis is required to carry out these calibrations. A framework for LRFD calibration has been proposed by the writers that requires bias statistics for load and resistance terms for each limit state function. In this paper the formulation of the limit state for reinforcement tensile rupture is developed and the component strength-reduction bias statistics identified. The paper describes how to compute bias statistics from project-specific installation damage trials for use in reliability-based design for the reinforcement rupture limit state or using data from multiple sources for LRFD cali...
A new evaluation of the 1% time strain limit for creep strength and the isochronous stress/strain relationship was to be undertaken for the type 800 alloy, based on up to date experimental data. After the evaluation of the 1% time strain limit curves and time fracture curves of individual melts, multilinear regression analyses were made to clear up the relationship between parameters of the creep behaviour such as creep strength, 1% time strain limit and time fracture strain on the one hand and metallurgical parameters such as C, Ti, Al, Ni, Cr contents or grain size and type of manufacture, on the other hand. Based on the knowledge gained from these calculations, new limits were determined for HTR material specifications for variants of the 800 alloy of the Rk, NT, DE, and HT type. (orig./DG).
The quantum nature of the electromagnetic field imposes a fundamental limit on the sensitivity of optical precision measurements such as spectroscopy, microscopy, and interferometry. The so-called quantum limit is set by the zero-point fluctuations of the electromagnetic field, which constrain the precision with which optical signals can be measured. In the world of precision measurement, laser-interferometric gravitational wave (GW) detectors are the most sensitive position meters ever operated, capable of measuring distance changes on the order of 10^-18 m RMS over kilometer separations caused by GWs from astronomical sources. The sensitivity of currently operational and future GW detectors is limited by quantum optical noise. Here we demonstrate a 44% improvement in displacement sensitivity of a prototype GW detector with suspended quasi-free mirrors at frequencies where the sensitivity is ...
... HAL and VAL limits with the specified PMD of 10-7, the GPS range-rate error must be monitored to assure that the inertial navigation error is not ...
During the last years one focus of German PWR safety analysis was boron dilution events with the potential of reactivity transients. Coolant with a low boron concentration could be collected in localized areas of the reactor coolant system e.g. by separation of borated reactor coolant into highly concentrated and diluted fractions (inherent dilution) which can occur during reflux- condenser heat transfer after a small break loss of coolant accident with a limitedavailability of the emergency core cooling systems. The TUeV NORD SysTec was charged by German supervisory authorities with the assessment of the safety analyses of boron dilution events presented by the utilities. These analyses are based on the simulation of boron dilution and transport processes in conjunction with a number of dedicated experiments. The analyses shall demonstrate that boron dilution events cannot lead to recriticality of the core. Hence the boron concentration at ...
During the last years one focus of German PWR safety analysis was boron dilution events with the potential of reactivity transients. Coolant with a low boron concentration could be collected in localized areas of the reactor coolant system e.g. by separation of borated reactor coolant into highly concentrated and diluted fractions (inherent dilution) which can occur during reflux- condenser heat transfer after a small break loss of coolant accident with a limitedavailability of the emergency core cooling systems. The TUeV NORD SysTec was charged by German supervisory authorities with the assessment of the safety analyses of boron dilution events presented by the utilities. These analyses are based on the simulation of boron dilution and transport processes in conjunction with a number of dedicated experiments. The analyses shall demonstrate that boron dilution events cannot lead to recriticality of the core. Hence the boron concentration at ...
AECL is undertaking the validation of ADDAM, an atmospheric dispersion and dose code based on the Canadian Standards Association model CSA N288.2. The key component of the validation program involves the comparison of air concentrations predicted by the model with measured values. Measurements are available from field studies at two Canadian reactor sites and from a wind tunnel study of the CANDU site at Wol song, Korea. The measurements were obtained close enough to the release points to test the model for exclusion area boundaries as small as 500 m. Model predictions were higher than the observations almost 75 percent of the time and the magnitude of the over predictions was typically much larger than the magnitude of the under predictions. The effect of the topography at the Wol song site was limited to small changes in plume trajectory due to channeling in valleys and a small reduction in the lateral spread of the plume. The terrain did not ...
During the last years, boron dilution events with the potential of reactivity transients were an important issue of German PWR safety analyses. A coolant with a low-boron concentration could be collected in localized areas of the reactor coolant system, e.g., by separation of a borated reactor coolant into highly concentrated and diluted fractions (inherent dilution) which can occur during reflux-condenser heat transfer after a small break loss of coolant accident with a limitedavailability of the emergency core cooling systems. During the course of follower core assessments, TUV NORD SysTec appraises safety analyses of boron dilution events presented by the utilities. These analyses are based on the simulation of boron dilution and transport processes in conjunction with a number of dedicated experiments. The analyses demonstrate that boron dilution events cannot lead to recriticality of the core. Hence, the boron concentration at the core ...
The strategy for management of the Oak Ridge National Laboratory`s (ORNL) radioactively contaminated liquid waste was reviewed in 1991. The latest information available through the end of 1990 on waste characterization, regulations, US Department of Energy (DOE) budget guidance, and research and development programs was evaluated to determine how the strategy should be revised. Few changes are needed to update the strategy to reflect new waste characterization, research, and regulatory information. However, recent budget guidance from DOE indicates that minimum funding will not be sufficient to accomplish original objectives to upgrade the liquid low-level waste (LLLW) system to comply with the Federal Facilities Agreement, provide long-term LLLW treatment capability, and minimize environmental, safety, and health risks. Options are presented that might allow the ORNL LLLW system to continue operations temporarily, but they would significantly reduce its ...
Coal is the most abundant available fossil fuel in Australia and provides a substantial part of energy needs. It is used for power generation, to supply energy to industry as well as for domestic requirements. Analysis of trace elements (the elements present in coal in ppm/ppb level) during combustion of coal in very important. Trace elements, like heavy metals such as arsenic, selenium, and chromium etc. are hazardous to the environment and some of them have carcinogenic potency. In the near future more stringent limits may be proposed for such elements generated from combustion process, such as coal combustion in power plants. Hence analysis and assessment of the emissions of these elements is essential at this stage. The first step towards reducing any impacts of trace elements is to have accurate quantitative analysis. Analysis of coal, bottom ash and fly ash collected from five different power stations across Australia was carried out to ...
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 different iron loadings have ...
Renewable energy technologies such as photovoltaics, solar thermal power plants, and wind turbines are nonconventional, environmentally attractive sources of energy that can be considered for electric power generation. Many of the areas with abundant renewable energy resources (very sunny or windy areas) are far removed from major load centers. Although electrical power can be transmitted over long distances of many hundreds of miles through high-voltage transmission lines, power transmission systems often operate near their limits with little excess capacity for new generation sources. This study assesses the available capacity of transmission systems in designated abundant renewable energy resource regions and identifies the requirements for high-capacity plant integration in selected cases. In general, about 50 MW of power from renewable sources can be integrated into existing transmission systems to supply local loads without transmission ...
This report discusses the safety approach of the Advanced Liquid Metal reactor program, sponsored by the US Department of Energy, which relies upon passive reactor responses to off-normal condition to limit power and temperature excursions to levels that allow safety margins. Gas expansion modules (GEM) have included in the design to provide negative reactivity to enhance these margins in the extremely unlikely event that pumping power is lost and the highly reliable scram system fails to operate. The feasibility and beneficial features of these devices were first demonstrated in the core of the Fast Flux Test Facility (FFTF) in 1986. Preapplication safety evaluations by the US Nuclear Regulatory Commission have identified areas that must be addressed if these devices are to be relied on. One of these areas is the response of the reactor when it is critical and the pumps are turned on, resulting in positive reactivity being added to the core. Tests to examine such ...
The safety approach of the Advanced Liquid Metal Reactor program, sponsored by the U.S. Department of Energy, relies upon passive reactor responses to off-normal conditions to limit power and temperature excursions to levels that allow large safety margins. Gas expansion modules (GEM) have been included in the design to provide negative reactivity to enhance these margins in the extremely unlikely event that pumping power is lost and the highly reliable scram system fails to operate. The feasibility and beneficial features of these devices were first demonstrated in the core of the Fast Flux Test Facility (FFTF) in 1986. Pre-application safety evaluations by the U.S. Nuclear Regulatory Commission have identified areas that must be addressed if these devices are to be relied on. One of these areas is the response of the reactor when it is critical and the pumps are turned on, resulting in positive reactivity being added to the core. Tests to examine such transients ...
Following a referendum in Italy in 1987, the four Nuclear Power Plants (NPPs) owned and operated by the state utility ENEL were closed. After closing the NPPs, ENEL selected a ''safestore'' decommissioning strategy; anticipating a safestore period of some 40-50 years. This approach was consistent with the funds collected during plant operation, and was reinforced by the lack of both a waste repository and a set of national free release limits for contaminated materials in Italy. During 1999, twin decisions were made to privatize ENEL and to transform the nuclear division into a separate subsidiary of the ENEL group. This group was renamed Sogin and during the following year, ownership of the company was transferred to the Italian Treasury. On formation, Sogin was asked by the Italian government to review the national decommissioning strategy. The objective of the review was to move from a safestore strategy to a prompt ...
A study trip to a biomass gasification plant in Germany took place from 13-15 November 2000. The goal of the trip was to obtain information on German developments, experience, and possibilities in the field of biomass gasification. The participants were representatives of Dutch parties in the energy sector: waste sector, manufacturers, producers, policy makers and consultants. The most important feature was the visit to plants that were in operation. Due in particular to the new EEG (Emeuerbare-Energien-Gesetz/Renewable Energy) legislation, German policy makers have created an initial market for sustainable energy with a degree of success. The key feature is that EEG makes projects 'bankable' by guaranteeing a return delivery compensation. An EEG-type scheme designed to accelerate the development of sustainable energy could be an interesting instrument also for the Netherlands. The plan was to visit four plants and have a number of presentations in a period of three days. Preference ...
Tumor-targeted monoclonal antibodies (mAb) might be useful as diagnostic or therapeutic agents when linked to cytotoxic or imaging reagents. Our group is working to test this hypothesis by linking cytocidal and image-producing isotopes to mAb and testing the utility of the radioimmunoconjugates formed in animal model systems. Radioiodines were first employed for these purposes,but unfavorable nuclear properties (half-lives, #gamma#-ray and #beta#-particle energies) and chemical reactivity (deiodination in vivo) limit their utility. Labeling immunoproteins with metallic radionuclides offers more versatility in that the selection of potentially useful radiometals spans the periodic table.Of the metallic radionuclides with physical properties most suited for use with mAb in nuclear medicine, few are more available or desirable than those of bismuth ("2"1"2Bi) and lead ("2"0"3Pb, "2"1"2Pb), as listed in Table 1. "2"1"2Bi or "2"1"2Pb could serve as ...
Improvements in electric submersible pumping systems have resulted in a demonstrated downhole running life of one year for low horsepower units operating in 180 C brine. The implementation of a prototype pressurized lubrication system to prevent brine intrusion and loss of lubricating oil from the motor and protector sections has been successfully tested. Second generation pressurized lubrication systems have been designed and fabricated and will be utilized in downhole production pumping tests during FY84. Pumping system lifetime is currently limited by available power cable designs that are degraded by high-temperature brine. A prototype metal-sheathed power cable has been designed and fabricated and is currently undergoing destructive and nondestructive laboratory testing. This cable design has the potential for eliminating brine intrusion into the power delivery system through the use of a hermatically sealed cable from the surface to the ...
Pipe whip restraints are used in nuclear power plants in order to limit the consequences of ruptured pipe whip effects and are thus an important part of the plant safety concept. The design of these devices is based on the choice of adequate construction and computational analysis supported by experimental investigation. Pipe whip restraints should, by means of deforming components, be able to absorb the energy of a ruptured pipe accelerated by the fluid reaction force. Since the elastic deformation of the restraint material is not sufficient for this purpose, or would result in excessive anchor loads, pipe whip restraints must generally be designed to work in the plastic range. Two types of restraints are presented in this paper, including the description of their mode of operation, design and computation. A comparison and critical evaluation of the calculation methods presently available are also given. The range of methods covers those ...
During 1994 and the early part of 1995, the US Department of Energy's Yucca Mountain Site Characterization Office (YMSCO) and its parent organization, the Office of Civilian Radioactive Waste Management (OCRWM) underwent a significant restructuring. Senior Department officials provided the leadership to reorient the management, technical, programmatic, and public interaction approach to the US High Level Radioactive Waste Disposal Program. The restructuring involved reorganizing the federal staff, conducting meaningful strategic planning, improving the management system, rationalizing contractor responsibilities, focusing upon major products, and increasing stakeholder involvement. The restructured program has prioritized technical and scientific activities toward meeting major regulatory milestones in a timely and cost-effective manner. This approach has raised concern among elements of technical, scientific, and oversight bodies that suitability and licensing decisions could be made ...
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, which involve the ...
In January 1981, a dual-fuel engine of type 8L52/55 ADG, with the highest cylinder rating of all four-stroke gas engines currently available, succesfully completed its test run on M.A.N.s test bed at Augsburg. The engine can be operated either on Diesel oil or on gas and pilot oil and can be switched from Diesel to gas operation or vice versa at any load during operation. In gas operation, the engine works on the pilot injection principle. By changing from pulse-pressure to constant-pressure turbocharging, matching the charge-air pressure, improving mixture formation and optimising the injection system, M.A.N. has succeeded in achieving a high power output while reducing the heat consumption in gas operation almost to its level in Diesel operation. A close look is taken at the design features which distinguish the dual-fuel engine from the 52/55 A Diesel engine, such as the gas supply, injection system and automatic change-over system. Mixture formation and ...
The regional impacts of ozone on corn, wheat, soybean, and peanut crops are estimated by using dose-response functions to relate ambient maximum 7 h/d seasonal ozone concentrations to crop productivity data. Linear dose-response functions were developed from open-top field chamber studies. It was assumed that the limited number of cultivars and growing conditions available for the analysis were representative of major agricultural regions. Hourly ozone data were selected to represent rural concentrations and used to calculate maximum 7-h/d average values. Seasonal ozone averages for counties were extrapolated from approximately 300 monitoring sites. Results must be interpreted with knowledge of these assumptions and sources of uncertainty. Impacts are calculated for county units for the conterminous United States with maps showing patterns and tables summarizing the potential magnitude of ozone effects on selected crop yields. The assessment ...
Due to the cyclical human life, utility loads appear to be cyclical too. During daytime when most factories are in operation, the electricity demand is very high. On the contrary, when most people are sleeping from midnight to daybreak, the electric load is very low, usually only half of the peak load amount. To meet this large gap between peak load and light load, utilities must idle many generation plants during light load period while operating all generation plants during peak load period no matter how expensive they are. This low utilization factor of generation plants and uneconomical operation have sparked utilities to invest in energy storage devices such as pumped storage plants, compressed air energy storage plants, battery energy storage systems (BES) and superconducting magnetic energy storage systems (SMES) etc. Among these, pumped storage is already commercialized and is the most widely used device. However, it suffers the limit of ...
In an earlier paper (Phys. Rev. Lett. 66, 41 (1991)), we calculated both the dielectric constant ({epsilon}{sub {infinity}}) and the nonlinear optical susceptibilities for second-harmonic generation ({chi}{sup (2)}) in the static limit for AlP, AlAs, GaP, and GaAs in the local-density approximation with and without a self-energy correction in the form of a scissors operator,'' including local-field effects. In this paper, we expand our presentation of this calculation. Agreement with experiment to within 15% for the nonlinear susceptibility is demonstrated where experiments are available (GaP and GaAs); the dielectric constants are in no worse than 4% agreement with experiment. The virtual hole'' contributions are reformulated to avoid large numerical cancellations in the case of near degeneracies. The virtual electron'' terms dominate over the virtual hole'' terms ...
The results of a scoping study of onsite radiation exposures which could take place in each of three types of postulated reactor accidents are presented. The accident types are (1) a fuel handling accident at a Mark III BWR; an interfacing system LOCA or V sequence at a PWR; and and Anticipated Transient Without Scram (ATWS) at a Mark I BWR. Both external and internal dose pathways are considered. The results of the study indicate the prohibitively high radiation doses could be received in some plant areas if personnel were to remain there. However, times of the order of a few minutes to a few hours, depending on the type of accident, would be available before life-threatening doses would be accumulated assuming that the provided full face respiratory protection equipment were used promptly. Special attention was given radiation doses possibly received by control room personnel for several control room air in-leakage assumptions. For occupancy during severe ...
The purpose of this report is to provide a brief overview and bibliography of those techniques that may have application for the evaluation of a site to determine if a high energy release event is nuclear in nature. This effort is motivated by recognition of the changing world political climate and the perception that low yield and non-proliferation issues will grow in importance as countries become increasingly involved as signators to treaties that are intended to limit the development and testing of nuclear weapons. Along with an increasing interest in such issues is the awareness of the need to implement improved capabilities for treaty monitoring programs that must deal with assessing suspicious occurrences of high energy release events. In preparing this report, it is recognized that monitoring can take two main forms. The first involves the resolution of unidentified events detected by seismic and satellite National Technical Means. Events of an ...
This dissertation deals with the control of active power flow, or load flow in electric power systems. During the last few years, interest in the possibilities to control the active power flows in transmission systems has increased significantly. There is a number of reasons for this, coming both from the application side - that is, from power system operations - and from the technological side. where advances in power electronics and related technologies have made new system components available. Load flow control is by nature a multi-input multi-output problem, since any change of load flow in one line will be complemented by changes in other lines. Strong cross-coupling between controllable components is to be expected, and the possibility of adverse interactions between these components cannot be rejected straightaway. Interactions with dynamic phenomena in the power system are also a source of concern. Three controllable components are investigated in this ...
The dissolution of NiO cathodes during cell operation is a limiting factor to the successful commercialization of molten carbonate fuel cells (MCFCs). Lithium cobalt oxide coating onto the porous nickel electrode has been adopted to modify the conventional MCFC cathode which is believed to increase the stability of the cathodes in the carbonate melt. The material used for surface modification should possess thermodynamic stability in the molten carbonate and also should be electro catalytically active for MCFC reactions. Two approaches have been adopted to get a stable cathode material. First approach is the use of LiNi{sub 0.8}Co{sub 0.2}O{sub 2}, a commercially available lithium battery cathode material and the second is the use of tape cast electrodes prepared from cobalt coated nickel powders. The morphology and the structure of LiNi{sub 0.8}Co{sub 0.2}O{sub 2} and tape cast Co coated nickel powder electrodes were studied using scanning ...
A thermophotovoltaic (TPV) generator for electric vehicles has been designed and developed. In this paper we focus on the combustion system and the heat regenerator. The system has been designed to work as a range extender for electric vehicles. This solution would provide energy always available on the vehicle, which would run even if the battery level were low. Several configurations for the burner and for the heat exchanger have been investigated and a comparison of these is presented. The different solutions have been studied both theoretically and experimentally. In this paper, we report on the work carried out to build a TPV device capable of yielding 6 kW of electric power to recharge the battery pack of an electric city-car. The project has been divided into four steps: (1) pre-design of different configurations of the burner and heat exchanger using non-commercial software 'TPV Design Tool 1.0'; (2) testing of the pre-designed generators ...
Probabilistic risk analysis has historically been developed for situations in which measured data about the overall reliability of a system are limited and expert knowledge is the best source of information available. There continue to be a number of important problem areas characterized by a lack of hard data. However, in other important problem areas the emergence of information technology has transformed the situation from one characterized by little data to one characterized by data overabundance. Natural disaster risk assessments for events impacting large-scale, critical infrastructure systems such as electric power distribution systems, transportation systems, water supply systems, and natural gas supply systems are important examples of problems characterized by data overabundance. There are often substantial amounts of information collected and archived about the behavior of these systems over time. Yet it can be difficult to ...
Understanding the mechanical properties of biomedical devices is critical in predicting and preventing their failure in the body. Such knowledge is essential, for example, in the design of biomedical stents, which must undergo repeated strain over their ten year lifetimes without breaking. Computational models are used to predict mechanical response of a device, but these models are not complete; there are significant deviations from the predictions, especially when devices are subjected to repeated multi-axial loads. Improving these models requires comparisons with actual measurements of strained nitinol. Local measurements of the full strain tensor can be made using X-ray diffraction techniques, but they are currently limited to materials whose grain size is larger than the X-ray beam size or require several diffraction patterns produced by rotation of the sample. Nitinol stents are nanocrystalline, with grains smaller than any available ...
In the developed world, grid-connected photovoltaics (PVs) are the fastest-growing segment of the energy market. From 1999 to 2009, this industry had a 42% compound annual growth-rate. From 2009 to 2013, it is expected to grow to 45%, and in 2013 the achievement of grid parity - when the cost of solar electricity becomes competitive with conventional retail (including taxes and charges) grid-supplied electricity - is expected in many places worldwide. Grid-connected PV is usually perceived as an energy technology for developed countries, whereas isolated, stand-alone PV is considered as more suited for applications in developing nations, where so many individuals still lack access to electricity. This rationale is based on the still high costs of PV when compared with conventional electricity. We make the case for grid-connected PV generation in Brazil, showing that with the declining costs of PV and the rising prices of conventional electricity, urban populations in Brazil will also ...
The implementation of a three-dimensional conformal radiotherapy facility in the radiotherapy department of the Heinrich Heine University is described. Complex radiotherapy techniques with commercially available networked systems are introduced to improve clinical work. Over 18 month we have gained clinical experience with a PHILIPS Multileaf Collimator (MLC) mounted on a SL 25 linear accelerator. For a limited period the MLC was used as a conventional blocking device. The standard MLC-shapes are controlled with a stand-alone computer system. In addition, a three-dimensional treatment planning system (3-D-TPS / TMS-Radix, Helax AB) based on convolution/superposition algorithms was recently installed. Treatment optimization is achieved using static field arrangements with complete volumetric computerized tomographic patient data for 3-D-TPS. Conformal adaptation of the 95%-isodose to the Planning Target Volume (PTV, ICRU 50) results in ...
Computer programs have been written to allow the analysis of different types of eddy-current probes and their performance under different steam generators test conditions. The probe types include the differential bobbin probe, the absolute bobbin probe, the pancake probe and the reflection probe. The generator test conditions include tube supports, copper deposits, magnetite deposits, denting, wastage, pitting, cracking, and intergranular attack. These studies are based mostly on computed values, with the limited number of test specimens available used to verify the computed results. The instrument readings were computed for a complete matrix of the different test conditions, and then the test conditions determined as a function of the readings by a least-squares technique. A comparison was made of the errors in fit and instrument drift for the different probe types. The computations of the change in instrument reading due to the defects have ...
High oleic acid sunflower oils have been commercially available for some years now. Due to their high content of monounsaturated fatty acids these oils have a number of potential applications in the oleochemical industry, especially where technical oleic acids and their derivatives are used. Whereas conventional sunflower oil contains approx. 68% linoleic acid (C{sub 1}8:2), it is now possible through breeding measures to obtain ''new sunflower oils'' (NSb oils) with oleic acid levels of 70-95% oleic acid (C{sub 1}8:1). The oil itself is of interest for technical applications: it is light-coloured, has a neutral odour and is relatively resistant to oxidation. Plant oils, especially those with a low content of polyunsaturated fatty acids, are increasingly gaining interest as ester oils in technical application areas, e.g. as lubricants. However, there are limits to the technical applicability of triglycerides ...
There are 1.4 Gt (1.5 billion st) of recoverable coal under less than 914 m (3,000 ft) of cover in Colorado in pitching seams. Snowmass Coal Co., in cooperation with the US Department of Energy, introduced the longwall mining method in pitching seams to North America. This venture is a coal mining research program directed toward the profitable production of coal under difficult mining conditions as found in pitching seams of the western US. Snowmass Coal classifies pitching seams into the following categories for longwall on the strike in seams 3 m (10 ft) or less thick: Flat = 0 to 10/sup 0/: Normal continuous mines and shuttle cars work efficiently. Slight = 10/sup 0/ to 22/sup 0/: The maximum pitch that rubber tired equipment will function. Moderate = 22/sup 0/ to 40/sup 0/: The angle of repose of mined coal. Steep = 40/sup 0/ to 60/sup 0/: The limit of safe use of this roof support. Vertical = over 60/sup 0/. The longwall roof support covered here will work in ...
Extracellular ATP stimulates transmembrane ion fluxes in the mouse macrophage cell line J774. In the presence of Mg2+, nonhydrolyzable ATP analogs and other purine and pyrimidine nucleotides do not elicit this response, suggesting the presence of a specific receptor for ATP on the macrophage plasma membrane. One candidate for such a receptor is the ecto-ATPase expressed on these cells. We, therefore, investigated the role of this enzyme in ATP-induced /sup 86/Rb+ efflux in J774 cells. The ecto-ATPase had a broad nucleotide specificity and did not hydrolyze extracellular ATP in the absence of divalent cations. /sup 86/Rb+ efflux was not blocked by inhibition of the ecto-ATPase and did not require Ca2+ or Mg2+. In fact, ATP-stimulated /sup 86/Rb+ efflux was inhibited by Mg2+ and correlated with the availability of ATP4- in the medium. In the absence of divalent cations, the slowly hydrolyzable ATP analogs adenosine 5'-(beta, gamma-imido)triphosphate ...
The clinical results of electron beam therapy using intraoral cone in 8 cases of primary and recurrence carcinoma of tongue (T1 and smaller T2) were reported. The primary and recurrence cases were 5 and 3, respectively. In the 5 cases, a total dose of 10-30 Gy external radiation therapy were combined prior to electron beam therapy. The total dose of electron beam therapy varied from 40 to 60 Gy. In all cases, tumor showed good response and disappeared clinically. Radiation stomatitis, pain of the tongue with masticatory disturbance due to tenderness were complicated in all cases. These complications gradually disappeared 2 to 6 months after treatment. However, loss of body weight and bone exposure were not recognized in any case. Intraoral-cone electron beam therapy is thought to be available and has less complications comparing interstitial irradiation therapy from the review of literature. Within 6 months after radiation, submandibular lymphnode metastasis ...
Surface analytical studies of high nitrogen austenitic stainless steels exposed to deaerated 0.1M HCl have revealed that nitrogen alloying additions influence the composition of salt layers and the passive film/alloy interface. In this study the authors employ electrochemical techniques and variable angle X-ray Photoelectron Spectroscopy (XPS) to examine the passive films formed on a series of austenitic stainless steels, Fe18Cr8Ni, Fe18Cr8Ni0.2N, Fe20Cr20Ni, Fe20Cr20Ni6Mo and Fe20Cr20Ni6Mo0.2N, in acidic chloride aqueous solution. In addition, several other model alloys, Fe19Cr, Fe19Cr9Ni, Fe19Cr2.5Mo, and Fe19Cr9Ni2.5Mo, were examined before and after electrochemical surface nitriding, a technique proven to have an effect analogous to N alloying. It was shown that nitrogen, nickel and molybdenum additions independently and in certain combinations stimulate selective dissolution of iron, resulting in a significant enrichment of chromium beneath the passive film. In most cases, the ...
Surface analytical studies of high nitrogen austenitic stainless steels exposed to deaerated 0.1M HCl have revealed that nitrogen alloying additions influence the composition of salt layers and the passive film/alloy interface. In this study the authors employ electrochemical techniques and variable angle X-ray Photoelectron Spectroscopy (XPS) to examine the passive films formed on a series of austenitic stainless steels, Fe18Cr8Ni, Fe18Cr8Ni0.2N, Fe20Cr20Ni, Fe20Cr20Ni6Mo and Fe20Cr20Ni6Mo0.2N, in acidic chloride aqueous solution. In addition, several other model alloys, Fe19Cr, Fe19Cr9Ni, Fe19Cr2.5Mo, and Fe19Cr9Ni2.5Mo, were examined before and after electrochemical surface nitriding, a technique proven to have an effect analogous to N alloying. It was shown that nitrogen, nickel and molybdenum additions independently and in certain combinations stimulate selective dissolution of iron, resulting in a significant enrichment of chromium beneath the passive film. In most cases, the ...
Fetal MRI can be performed in the second and third trimesters. During this time, the fetal brain undergoes profound structural changes. Interpretation of appropriate development might require comparison with normal age-based models. Consultation of a hard-copy atlas is limited by the inability to compare multiple ages simultaneously. To provide images of normal fetal brains from weeks 18 through 37 in a digital format that can be reviewed interactively. This will facilitate recognition of abnormal brain development. T2-W images for the atlas were obtained from fetal MR studies of normal brains scanned for other indications from 2005 to 2007. Images were oriented in standard axial, coronal and sagittal projections, with laterality established by situs. Gestational age was determined by last menstrual period, earliest US measurements and sonogram performed on the same day as the MR. The software program used for viewing the atlas, written in C, permits linked ...
This thesis develops methods for recording and analysis of seismo-acoustic interface waves for determination of shear wave velocity as a function of depth and includes this in standard refraction seismic surveying. It investigates different techniques for estimation of dispersion characteristics of the interface waves and demonstrates that multi sensor spectral estimation techniques improve the dispersion estimates. The dispersion estimate of the fundamental interface wave mode is used as input to an object function for a model based linearized inversion. The inversion scheme provides an estimate of the shear wave velocity as a function of depth. Three field surveys were performed. Data were acquired with a standard bottom deployed refraction seismic hydrophone array containing 24 or 48 receivers, with a receiver spacing of 2.5 m. Explosive charges were used as sources. The recording time was increased from 0.5 to 8 s, compared to standard refraction seismic surveys. Shear wave ...
Nuclear Forensics is a key element in the response process which is initiated after detection of illicit nuclear or other radioactive material. Credible nuclear forensics relies on appropriate sampling procedures, on validated analytical methods and on thorough data analysis and interpretation. Nuclear forensics aims at providing clues on the history and the potential origin of the material. Elemental and isotopic composition of the material, as well as its macroscopic and microscopic appearance reflect the technological processes used for the fabrication of the material. The nuclear forensic analysis first of all results in measurement data. Through appropriate processing of these data information on the nature and the history of the material can be obtained. A number of data evaluation techniques serving this purpose are conceivable and have been applied. On the one side, statistical methods like principal component analysis (PCA) or classification and regression trees (CART) can be ...
Proposals for use of Alloy 800 as a H.T.R. boiler material have prompted studies of its creep and high temperature fatigue properties in impure helium with comparative tests in air. In impure helium, as expected in a H.T.R., reactions of potential importance are selective oxidation (of chromium, aluminium and titanium) and possibly carburisation from carbon monoxide or methane. In air, general oxidation will occur, possibly accompanied by nitridation. The effects of these reactions will depend on specimen geometry and the nature of the deformation. Two important possibilities are: (i) that environment affects the structure and properties of a surface zone of material undegoing uniform deformation (this may modify creep rate and crack nucleation); and (ii) that environment affects behaviour of a small region (e.g. at the root of a notch or ahead of a crack) in a specimen undergoing non-uniform deformation (this will modify crack growth and hence rupture life or fatigue endurance). This ...
This report to the Nuclear Regulatory Commission (NRC) describes the development and application of a methodology to systematically and quantitatively assess predictive uncertainty in groundwater flow and transport modeling that considers the combined impact of hydrogeologic uncertainties associated with the conceptual-mathematical basis of a model, model parameters, and the scenario to which the model is applied. The methodology is based on a n extension of a Maximum Likelihood implementation of Bayesian Model Averaging. Model uncertainty is represented by postulating a discrete set of alternative conceptual models for a site with associated prior model probabilities that reflect a belief about the relative plausibility of each model based on its apparent consistency with available knowledge and data. Posterior model probabilities are computed and parameter uncertainty is estimated by calibrating each model to observed system behavior; prior parameter estimates ...
A potentially new use for Illinois coal is as a fuel injected into a blast furnace to produce molten iron as the first step in steel production. Because of its increasing cost and decreasing availability, metallurgical coke is now being replaced by coal injected at the tuyere area of the furnace where the blast air enters. The purpose of this study is to evaluate the combustion of coal during the blast furnace injection process and to delineate the optimum properties of the feed coal. This investigation is significant to the use of Illinois coal in that the limited research to date suggests that coals of low fluidity and moderate to high sulfur and chlorine contents are suitable feedstocks for blast furnace injection. During the first phase of this project a number of the objectives were realized, specifically: (1) a blast furnace sampling system was developed and used successfully to collect samples inside an active furnace; (2) two sets of ...
Element 97 was first produced in December 1949, by the bombardment of americium-241 with accelerated alpha particles. This new element was named berkelium (Bk) after Berkeley, California, the city of its discovery (Thompson, Ghiorso, and Seaborg, Phys. Rev. 77, 838 (1950); 80, 781 (1950)). In the 36 years since the discovery of Bk, a substantial amount of knowledge concerning the physicochemical properties of this relatively scarce transplutonium element has been acquired. All of the Bk isotopes of mass numbers 240 and 242 through 251 are presently known, but only berkelium-249 (..beta../sup -/ decay, 0.125 MeV, t/sub 1/2/ = 325 days) is available in sufficient quantities for bulk chemical studies. About 0.7 gram of this isotope has been isolated at the HFIR/TRU Complex in Oak Ridge, Tennessee in the last 18 years. Over the same time period, the scale of experimental work using berkelium-249 has increased from the tracer level to bulk studies at the microgram level ...
Thermoplastic polymer materials and the compounds made with them are being used more frequently for industrial components and for general use. However, the application of these materials for the production of complex shaped or relatively large pieces is limited, because of the difficulty and cost of making the necessary tool kit for the job. One solution is the use of the welding process. But the safe and reliable union of different thermoplastic material parts is not a simple process, even less so in the case of unions of large components. Welding by microwaves using polymer conductors can help, since the large scale equipment is available, and methods for continuous processes by microwave have been developed, that can be used to weld large and small components. Many thermoplastics (ex. polyethylene) do not absorb, or absorb very little, energy from microwaves. Polymer conductors, however, heavily absorb from microwaves with the consequent ...
This paper describes an approach to solve air quality problems which frequently occur during iterations of the baseline change process. From a schedule standpoint, it is desirable to perform this evaluation in as short a time as possible while budgetary pressures limit the size of the staff available to do the work. Without a method in place to deal with baseline change proposal requests the environment analysts may not be able to produce the analysis results in the time frame expected. Using a concept called the Rapid Response Air Quality Analysis System (RAAS), the problems of timing and cost become tractable. The system could be adapted to assess other atmospheric pathway impacts, e.g., acoustics or visibility. The air quality analysis system used to perform the EA analysis (EA) for the Salt Repository Project (part of the Civilian Radioactive Waste Management Program), and later to evaluate the consequences of proposed baseline changes, ...
The wind unit working wheel has 4 radial rectangular frames arranged in two vertical planes which are perpendicular to each other. In the planes limited by the frames, on loop hinges with limiting supports, there are flat blades. When the working wheel rotates under the influence of wind pressure, the blades automatically occupy a vertical or horizontal (wind vane) position depending on the direction of blade motion and the direction of wind velocity.
This chapter is concerned with standards and guidances for limiting radiation exposures. It is divided into three sections, each of which has several parts. Section 1: Ionizing Radiation -- Standards and Guidances Applicable to the Public: Part A, Radiation Protection Standards; Part B, Environmental Radiation Standards; Part C, Exempt Levels of Radioactivity; Part D, Protective Action Guides for Accidents. Section 2: Ionizing Radiation -- Standards Applicable to the Workplace. Section 3: Medical and Other Standards.
DescriptionAbstract of Research Proposal The root environment has a major effect on crop growth, both directly through the supply of water and nutrients to the shoot, and indirectly through root to shoot signalling. Better management of crop root systems through agronomic and genetic means has the potential to improve the efficiency of water and nutrient uptake, and limit root restrictions to crop growth. However, progress in this area is currently limited by the lack of sensors for in situ estimates of [continued...
Overcoming the limiting constraints of stimulated Raman scattering (SRS) and stimulated Brilluoin scattering (SBS) poses serious fibre design challenges for increasing the output power of optical amplifiers and lasers. New fibre amplifier designs are proposed to break out of these limitations to reach several kWs CW powers. (Author)
Certain transition metal chalcogenides are promising materials for use as cathodes in nonaqueous lithium batteries involving the intercalation into these layered compounds. The electrochemical behavior of the chalcogenides depends on various properties such as structure, stoichiometry, electrical conductivity, crystal morphology, etc. The influence of these properties and of the ultimate practical application of the battery on the selection of cathode material is discussed. Battery performance of selected cathode materials is discussed and life limitations due to the limited cycle life of lithium anodes are outlined. 15 refs.
We prove a uniqueness result for limit cycles of the second order ODE $\\ddot x + \\sum_{j=1}^{J}f_{j}(x)\\dot x^{j} + g(x) = 0$. We extend a uniqueness result proved in \\cite{CRV}. The main tool applied is an extension of Massera theorem proved in \\cite{GS}.
The solar array wings were deployed by swinging two half-blanket boxes open from a folded hinge launch position .... pure-water by-product of the shuttle's fuel cell power generators because ..... outgassing limits, flammability limits, ... Foale fills a water microbiology bag for in-flight analysis. ...
Central limit theorem estimates of anomalous fractal dimensions of self-similar random cascades are studied. It is found that, in general, the normal approximation fails badly. A systematic series of approximations which converges to the exact result (both for the fractal dimensions and for the distribution itself) is derived for the {alpha}-model. Consequences for the 'empty bin effect' are indicated. (orig.).
The Focused-Ion-Beam (FIB) is a powerful tool for fast, precision cross-sectioning and inspection of submicron defects in multilayered integrated circuit devices. However, the low contrast between the layers in FIB cross-sections can make the feature of interest difficult to observe, which has become a limitation for FIB cross-sectioning. A technique using plasma etch to decorate the FIB cross-sections has proven to be a simple solution to overcome this limitation.
We analyze large diffusion-limited aggregates and uncover a {ital discrete} scaling invariance in their inner structure, which can be quantified by the introduction of a set of {ital complex} fractal dimensions. We provide a theoretical framework and prediction of their values based on renormalization group theory and a previous wavelet analysis. {copyright} {ital 1996 The American Physical Society.}
We present a method for obtaining the quasi-exact solutions of the Rabi Hamiltonian in the framework of the asymptotic iteration method (AIM). The energy eigenvalues, the eigenfunctions and the associated Bender-Dunne orthogonal polynomials are deduced. We show (i) that orthogonal polynomials are generated from the upper limit (i.e., truncation limit) of polynomial solutions deduced from AIM, and (ii) prove to have nonpositive norm. (authors)