UK PubMed Central (United Kingdom)
Vulnerability to abused drugs is influenced by multiple genes unique to each drug as well as to risk genes for polydrug abuse. If several inbred mouse strains respond to different drugs similarly,...Full Text Available
2008-11-01
Drama-based education to motivate participation in substance abuse prevention
UK PubMed Central (United Kingdom)
BackgroundThe substance abuse prevention goal of the theatre production "TUNNELS" was to provide community education on substance abuse to an audience in Durham, NC and surrounding...Full Text Available
Advances in Statistical Methods for Substance Abuse Prevention Research
UK PubMed Central (United Kingdom)
The paper describes advances in statistical methods for prevention research with a particular focus on substance abuse prevention. Standard analysis methods are extended to the typical research...Full Text Available
2003-09-01
Followup study of possible HIV seropositivity among abusers of parenteral drugs in 1971-72.
UK PubMed Central (United Kingdom)
Serum specimens obtained from a nationwide sample of parenteral drug abusers (PDAs) during the period 1971-72 had previously been screened for human immunodeficiency virus (HIV) antibodies. Some specimens...Full Text Available
1991-07-01
UK PubMed Central (United Kingdom)
Clinical features and treatment outcome were compared in depressed outpatients with and without a history of emotional and physical abuse (EPA), including childhood maltreatment. Patients were...Full Text Available
2010-04-01
Tackling the Steroid Issue: Squeezing Out the Juice
... Abuse (162) Alcoholism (12) Anxiety Disorders & Phobias (4) Attention-Deficit-Hyperactivity Disorder (3) B Binge Drinking (37) Bipolar Disorder (1) ...
Progress and Compliance in Alcohol Abuse Treatment*
UK PubMed Central (United Kingdom)
Improving patient compliance with physicians’ treatment or prescription recommendations is an important goal in medical practice. We examine the relationship between treatment progress...Full Text Available
2010-03-01
UK PubMed Central (United Kingdom)
Dopamine (DA) D3 and D2 receptor mechanisms are implicated in cocaine's abuse-related behavioral effects, but the relative contribution of the two receptor subtypes is only partially characterized....Full Text Available
2010-08-01
IMPROVED FORMULATIONS FOR COMBUSTIBLE ...
... Accession Number : AD0152957. Title : IMPROVED FORMULATIONS FOR COMBUSTIBLE CARTRIDGE CASES. Corporate ...
1958-01-01
British Library Electronic Table of Contents (United Kingdom)
ObjectiveThe aims of the study were to: determine the attitudes of parents, pediatric residents, and medical students from a Turkish population toward childhood disciplinary methods; ascertain the association of participants' abusive childhood history with their attitudes toward discipline; and assess their attitudes about disciplinary actions, which should be reported as abuse.MethodA cross-sectional survey was conducted in Ankara University School of Medicine, Department of Social Pediatrics. Sixty-five parents, 39 pediatric residents, and 106 medical students completed a questionnaire (Survey of Standards of Discipline). This questionnaire was designed to measure sociodemographic characteristics, attitudes toward childhood disciplinary practices, and abusive childhood experiences. There...
2006-01-01
UK PubMed Central (United Kingdom)
ObjectivesUse of prescription opioids for chronic pain is increasing, as is abuse of these medications, though the nature of the link between these trends is unclear....Full Text Available
2010-01-01
Sex-related differences among 100 patients with alcoholic liver disease.
UK PubMed Central (United Kingdom)
During 1975 we studied 100 patients--77 men and 23 women--who had a history of alcohol abuse and disturbed liver function test results. On presentation the women were less likely to be suspected of...Full Text Available
1977-04-09
UK PubMed Central (United Kingdom)
The juxtacapsular BNST (jcBNST) is activated in response to basolateral amygdala (BLA) inputs through the stria terminalis and projects back to the anterior BLA and to the central nucleus of...Full Text Available
2009-04-29
UK PubMed Central (United Kingdom)
The nicotinic acetylcholine receptor (AChR) controls signal transmission between cells in the nervous system. Abused drugs such as cocaine inhibit this receptor. Transient kinetic investigations indicate...Full Text Available
1998-11-24
Cocaine induces cell death and activates the transcription nuclear factor kappa-b in pc12 cells
UK PubMed Central (United Kingdom)
Cocaine is a worldwide used drug and its abuse is associated with physical, psychiatric and social problems. The mechanism by which cocaine causes neurological damage is very complex and involves several...Full Text Available
UK PubMed Central (United Kingdom)
The tendency for some individuals to partake in high-risk behaviors (eg, substance abuse, gambling, risky sexual activities) is a matter of great public health concern, yet the characteristics and neural...Full Text Available
2010-07-01
UK PubMed Central (United Kingdom)
Muscarinic cholinergic receptors modulate dopaminergic function in brain pathways thought to mediate cocaine's abuse-related effects. Here, we sought to confirm and ...Full Text Available
2010-01-01
To illustrate the implementation of a bottom-up approach to the study of culture in health disparities, this article describes the development of a cultural cancer screening scale (CCSS) using mixed methodologies. The aim was to identify cultural factors relevant to breast and cervical cancer screening, develop an instrument to assess them and examine its preliminary psychometric properties among Latin American (Latino) and non-Latino White (Anglo) women in Southern California. Seventy-eight Latino and Anglo women participated in semi-structured interviews, which were content coded based on Triandis' methods for the analysis of subjective culture. Based on the emerging cultural elements, items relevant to cancer screening were developed and pilot tested with 161 participants. After the instrument was refined, 314 Latino and Anglo women from various socioeconomic backgrounds completed the CCSS and data were factor analyzed resulting in five cultural factors: cancer screening fatalism, ...
2010-09-23
Signatures of testing: On-site inspection technologies
Energy Technology Data Exchange (ETDEWEB)
This paper describes the phenomenology of nuclear explosions and technologies for their detection as relevant to On-Site Inspection (OSI) for a comprehensive test-ban (CTB). Our experience with the US nuclear test program which has been primarily carried out at the Nevada Test Site (NTS) and in the Pacific Ocean. The goals of OSI are to resolve ambiguous events, reduce uncertainty, deter attempts at evasion, and provide responsive and technically competent means of confirming the occurrence of a nuclear explosion should deterrence fail. These goals would include finding evidence of an evasive nuclear explosion or evidence that the event was non-nuclear, such as an earthquake or large chemical explosion.
1995-01-01
Extended Deterrence, Nuclear Proliferation, and START III
Energy Technology Data Exchange (ETDEWEB)
Early in the Cold War, the United States adopted a policy of ''extended nuclear deterrence'' to protect its allies by threatening a nuclear strike against any state that attacks these allies. This threat can (in principle) be used to try to deter an enemy attack using conventional weapons or one using nuclear, chemical, or biological weapons. The credibility of a nuclear threat has long been subject to debate and is dependent on many complex geopolitical factors, not the least of which is the military capabilities of the opposing sides. The ending of the Cold War has led to a significant decrease in the number of strategic nuclear weapons deployed by the United States and Russia. START II, which was recently ratified by the Russian Duma, will (if implemented) reduce the number deployed strategic nuclear weapons on each side to 3500, compared to a level of over 11,000 at the end of the Cold War in 1991. The tentative limit ...
2000-06-20
The Effect of Lindane Formulations on Tissue Residues in Barrows and on Stillbirths in Sows
UK PubMed Central (United Kingdom)
The potential effect of lindane and its formulations on stillbirths and abortion in pregnant sows was investigated. One of four formulations of lindane were applied at five times the registered dosage...Full Text Available
1986-01-01
British Library Electronic Table of Contents (United Kingdom)
Background Previous reports in adults have suggested that the effects experienced after cannabis use can be described in terms of positive and negative subtypes that are heritable and are associated with abuse and dependence. This study extends existing research by inclusion of adolescents and young adults in an offspring of twins design which makes it possible to take into account genetic and environmental risks for substance use disorder. Methods Data were collected from 725 twin members of the Vietnam Era Twin Registry, 839 of their 12-32 year old biological offspring and 427 mothers. Offspring who had ever used cannabis (n=464) were asked the degree to which they typically experienced 13 subjective effects shortly after using cannabis. Latent class analysis (LCA) was used to derive sub...
2009-01-01
Safety testing of 18650-style Li-Ion cells
Energy Technology Data Exchange (ETDEWEB)
To address lithium-ion cell safety issues in demanding power applications, electrical and thermal abuse tests were performed on 18650 sized cells. Video and electrically monitored abuse tests in air included short circuit, forced overcharge, forced reversal, and controlled overheating (thermal) modes. Controlled overheating tests to 200 C were performed in a sealed chamber under a helium atmosphere and the gases released from the cell during thermal runaway were analyzed at regular intervals using gas chromatography and mass spectrometry. In addition to alkane and alkene solvent breakdown fragments, significant H{sub 2} was detected and evidence that HF was evolved was also found.
2000-06-08
Review of abuse of long distance telephone service (FTS) in the Department of Energy
Energy Technology Data Exchange (ETDEWEB)
It is concluded that the Department paid out over $16 million in the past two years for FTS service charges on telephone calls bearing no relationship to official Departmental business. When one adds in the costs of compensation paid to Departmental and contractor employees for the worktime spent making unauthorized FTS calls, the total costs to the Department due to FTS abuse exceeded $28 million for the fiscal years 1983 and 1984. These cost figures, moreover, fail to account for the effect of an annual loss of an estimated 40,000 man-days on the Department's productivity. It is recommended that the Assistant Secretary review the system to identify possible restrictions on usage of the lines by employees and to consider additional recording and accounting procedures to track FTS usage, especially when the lines are used for calls to telephones outside the FTS network.
1985-03-22
British Library Electronic Table of Contents (United Kingdom)
A qualitative method, involving supported liquid?liquid extraction (SLE) and ultra high pressure liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS?MS), was developed for the rapid tentative identification of various drugs of abuse in urine. In this study, 28 drugs and metabolites were covered by the screening procedure. Before analysis, urine samples were extracted by SLE and good extraction recoveries were obtained for most investigated compounds. The UHPLC strategy was then selected for the rapid separation of amphetamines, cocaine, opiates and related compounds in urine. Using columns packed with sub-2??m particles, analysis time was reduced down to 2?min, while maintaining acceptable performance. Finally, the detection was by tandem MS operating in the single reaction...
2009-01-01
An animal model of social instability stress in adolescence and risk for drugs of abuse
British Library Electronic Table of Contents (United Kingdom)
There is increasing evidence that adolescence, like early life, is a sensitive period in which ongoing brain development can be influenced by environmental factors. This review describes our use of social instability as a model of mild adolescent social stress, its effects on social interactions and on hypothalamic?pituitary?adrenal function over the course of the procedure and in response to new stressors. The effects of social instability are sex-specific, with qualitative differences between the sexes on HPA function over the course of the stressor procedure, and with greater effects in males on behaviour observed during the social instability and greater effects in females on behavioural responses to drugs of abuse into adulthood, long after the stress exposure. The results from invest...
2010-01-01
Some issues on Japanese nuclear armament
International Nuclear Information System (INIS)
The author considers the possibility that Japanese nuclear armament might be a realistic political option. Firstly introducing various issues on Japanese nuclear armament existing since long time ago, he classifies them according to the view point from internal and international problems. Internally, the armament is not possible at present on the ground of the nation's non-nuclear policy but it might be conditionally a choice in such case as the reliability of US nuclear deterrence declines or possibility of nuclear attack to Japan actually may be predicted. The armament may be possible technically and legally based on the consensus of the people. Various concerns by neighboring countries are discussed. Finally, the author stresses the importance of continuing to consolidate bilateral relationship with US, to deploy missile defensive system and to make every effort in the diplomatic activity for strong international ties and cooperation. (S. Ohno)
2007-07-01
Science and Technology Review July/August 2010
Energy Technology Data Exchange (ETDEWEB)
This issue has the following articles: (1) Deterrence with a Minimum Nuclear Stockpile - Commentary by Bruce T. Goodwin; (2) Enhancing Confidence in the Nation's Nuclear Stockpile - Livermore experts are participating in a national effort aimed at predicting how nuclear weapon materials and systems will likely change over time; (3) Narrowing Uncertainties - For climate modeling and many other fields, understanding uncertainty, or margin of error, is critical; (4) Insight into a Deadly Disease - Laboratory experiments reveal the pathogenesis of tularemia in host cells, bringing scientists closer to developing a vaccine for this debilitating disease. (5) Return to Rongelap - On the Rongelap Atoll, Livermore scientists are working to minimize radiological exposure for natives now living on or wishing to return to the islands.
2010-05-27
Nuclear War. The moral dimension
Energy Technology Data Exchange (ETDEWEB)
U.S. nuclear policy has become the target of increasing criticism during the past decade. Critics often argue that the use of nuclear weapons would be irrational, would destroy humankind, and thus could not serve any rational policy goal. Other critics point to the immortality of the use of nuclear weapons. Both groups condemn U.S. military policy. In Nuclear War, James Child considers and rejects both these lines of criticism. He argues that a policy of deterrence can be both rational and moral; that U.S. nuclear policy is, on balance, based on rational and moral foundations. Child examines near-term consequences of a nuclear war and finds them ghastly but not unthinkable or incomparable to the havoc produced by previous wars. He also analyzes long-term consequences, such as those proposed by the ''nuclear winter'' theory, and finds the fear of total annihilation of humankind to be unfounded.
1985-01-01
Standardization of Ajmodadi churna, a polyherbal formulation
UK PubMed Central (United Kingdom)
Standardization of herbal formulations is essential in order to assess the quality of drugs, based on the concentration of their active principles. This article reports on standardization of Ajmodadi...Full Text Available
2010-03-01
Extended BRS symmetry in non-Abelian gauge theories
Energy Technology Data Exchange (ETDEWEB)
In this paper, the superfield formulation of quantum gauge theories, recently proposed, is reviewed and developed. The extended BRS symmetry, which comes out quite naturally in this formulation, is investigated.
1981-08-01
The size of the hole in the ozone layer | Environment | guardian.co.uk
... Space weather is the biggest driver of ozone depletion and much else we are only beginning to understand. Solar Cycle 24 may turn out to be weak in terms of sun spot count but the amount of energy delivered by CME/SPE will probably not be. Remember that the Carrington Event in 1859 happened during a cycle with a lowish sun spot count. Recommend (1) Report abuse ...
British Library Electronic Table of Contents (United Kingdom)
Abstract Clonidine Extended Release Augmentation of Psychostimulants in ADHD ADHD a Risk Factor for Substance Abuse; Cognitive Deficits Not a Predictor Commentary on Kollins et al.; Clonidine XR Augmentation for ADHD Pharmacologic Treatment of Childhood Insomnias Effects of Guanfacine Extended Release on Alertness in ADHD Long Term ADHD Drug Treatment Bipolar Disorder Rates Similar Across Selected Countries Group CBT Alone or Group CBT Plus SSRIs in Childhood Anxiety Resolution of Quetiapine-Induced Oral Dyskinesia From the FDA
2011-01-01
... Wanting to help a charity is commendable but the main focus of generosity should be the people in front of you, not your choice of spiritual overlord - especially so if the group is being funded with money from taxpayers. Recommend? (44) Report abuse | Link ...
UK PubMed Central (United Kingdom)
Simultaneous bilateral femoral neck fractures are extremely rare and associated with various conditions. Up to now Most cases had correlations with major trauma, repetitive minor trauma, seizure, parathyroid...Full Text Available
UK PubMed Central (United Kingdom)
Parathyroid hormone (PTH) is used clinically in osteoporotic patients to increase bone mass by enhancing bone formation. PTH therapy is not uniformly effective at all skeletal sites and “lifestyle”...Full Text Available
2008-04-01
UK PubMed Central (United Kingdom)
Gonadotropin–releasing hormone (GnRH) neurons are the central regulators of reproduction. GABAergic transmission plays a critical role in pubertal activation of pulsatile GnRH secretion....Full Text Available
2010-05-12
Nuclear Forensics and Attribution for Improved Energy Security: The Use of Taggants in Nuclear Fuel
International Nuclear Information System (INIS)
The Global Nuclear Energy Partnership (GNEP), recently announced by DOE Secretary Bodman, poses significant new challenges with regard to securing, safeguarding, monitoring and tracking nuclear materials. In order to reduce the risk of nuclear proliferation, new technologies must be developed to reduce the risk that nuclear material can be diverted from its intended use. Regardless of the specific nature of the fuel cycle, nuclear forensics and attribution will play key roles to ensure the effectiveness of nonproliferation controls and to deter the likelihood of illicit activities. As the leader of the DHS nuclear and radiological pre-detonation attribution program, LLNL is uniquely positioned to play a national leadership role in this effort. Ensuring that individuals or organizations engaged in illicit trafficking are rapidly identified and apprehended following theft or diversion of nuclear material provides a strong deterrent against unlawful activities. Key to ...
Understanding Formulation Systems—A Six Sigma Approach
British Library Electronic Table of Contents (United Kingdom)
The broad use of Six Sigma in the improvement of all types of processes has provided new insight for how to design, analyze, and interpret formulation studies and mixture experiments. Experience has shown that, consistent with the Pareto principle, there are typically three to six key variables that have major effects on the performance of the process. Identifying these key variables increases your ability to control and optimize the process. Applying this concept to formulation studies suggests that we should be searching for those critical few components that are driving the performance of the product formulation. This thinking changes how we approach both the design and analysis phases of product formulation studies, including the reassessment of formulations in use today. A review of t...
2011-01-01
Examining the Presence of Problem Gambling Awareness Messages on College Counseling Center Websites.
College students are more at-risk for developing a gambling problem than the general adult U.S. population. Information behavior and information seeking theories, as well as empirical evidence, indicate that one resource that may provide guidance for students dealing with this issue is the college counseling center website (CCW). This study addressed the presence and nature of problem gambling messages on CCWs. As a random sample, 203 CCWs were selected to assess how frequently they provided any information about problem gambling, as well as the specific types of communications CCWs offered on this topic. Results showed that CCWs rarely included any messages about problem gambling. Specifically, only 15% of all CCWs contained information about problem gambling. Furthermore, messages about problem gambling were presented significantly less frequently than messages involving alcohol abuse, substance abuse, depression, anxiety/stress, and ...
2011-08-01
A preliminary study of a cartoon measure for children's reactions to chronic trauma.
Preliminary psychometric properties of a new instrument, Angie/Andy Cartoon Trauma Scales (ACTS), are presented. Angie/Andy features a cartoon-based methodology, measuring trauma-related sequelae of prolonged, repeated abuse. A sample of 208 children comprised intrafamilial trauma, extrafamilial trauma, combined trauma, and nontrauma groups. Angie/Andy demonstrated high internal consistency, with coefficient alphas from 0.70 to 0.95. The three trauma groups scored significantly higher than the nontrauma group on all scales (p's < 0.0001). Generally, the most severely traumatized group scored significantly higher than the less severely traumatized groups. The number of types of violence exposures correlated with Angie/Andy scores from 0.55 to 0.74. The frequency and severity of trauma exposure correlated with Angie/Andy scores from 0.44 to 0.56. The Angie/Andy parent version correlated with a standardized parent scale from 0.71 to 0.81. Parent/child agreement was ...
2000-08-01
Radioxenons: Their role in monitoring a Comprehensive Test Ban Treaty
Energy Technology Data Exchange (ETDEWEB)
Monitoring for xenon radionuclides which are produced in a nuclear detonation can provide a strong deterrent to the violation of a Comprehensive nuclear Test Ban Treaty (CTBT). There are 18 known radioactive xenon isotopes produced in nuclear fission with half-lives ranging from less than one second to 11.9 days. However, only four of these remain in significant amounts more than a day after a detonation. In order for radioxenon monitoring to be practical, it was necessary to develop an automated measurement system which could operate unattended for periods of months, measure the entire spectrum of radioxenons, and provide hundreds of times better sensitivities than current laboratory procedures. This capability was developed at the US Department of Energy`s Pacific Northwest National Laboratory based on rapid separation of atmospheric xenon coupled with a unique high sensitivity measurement device for the radioxenons. A fieldable prototype analyzer is scheduled ...
1996-06-01
Marine biodiesel use in the Puget Sound
Energy Technology Data Exchange (ETDEWEB)
This presentation explored the use of marine biodiesel in the Puget Sound region. Marine vessels are now adopting biodiesel fuels as a means of expressing corporate commitments to reducing greenhouse gas (GHG) emissions and the environmental impacts of hydrocarbons released into marine environments. Various biodiesel blends have been designed for use in small commercial, recreational, and research vessels. Biodiesel has also been adopted by charter and whale watching vessels in the Puget Sound. The Guemes Island Ferry has recently been re-configured to use biodiesel fuels, with 2 fuel tanks capable of receiving 2200 gallons at a time. The ferry adopted biodiesel after receiving soot complaints from marinas, and hopes to serve as a model for other vessels in the region. Four fueling docks supply the biodiesel blend to marine vessels. The sale of biodiesel has doubled in some marinas over the last 5 years. Deterrents to biodiesel use include parts incompatibilities ...
2008-07-01
[Fritz hauschild (1908-1974) and drug research in the 'German Democratic Republic' (GDR)].
The chemist and pharmacologist Fritz Hauschild developed the sympathomimetic agent Pervitin (metamphetamin) in the 1930s. Not only because of the abuse of the stimulant during the Second World War ("pilot's chocolate") it is one of the most controversial substances in drug history. Nearly forgotten are Hauschild's contributions to build up the drug system in the GDR. Although he was a convinced communist, the skilful pharmacologist gave very early warning of the imminent lack of innovation in the GDR pharmaceutical industry. A letter which he addressed to the Minister of Health, Max Sefrin (born 1913), did not lack explicitness. PMID:15997840
2005-06-01
Inhaled toluene produces pentobarbital-like discriminative stimulus effects in mice
The abuse of volatile solvents may be due to their ability to produce an intoxication similar to that produced by classical central nervous system depressants such as the barbiturates and ethanol. To evaluate this hypothesis, mice were trained to discriminate pentobarbital from saline injections in a two-lever operant task. Stimulus generalization was examined following 20-min inhalation exposures to toluene (300-5400 ppm). In 8 of 10 subjects, pentobarbital-lever responding occurred following toluene exposure indicating an overlap in the discriminative stimulus properties of toluene and pentobarbital.
1985-10-07
UK PubMed Central (United Kingdom)
UV, first, second and third derivative spectrophotometric methods have been developed for the determination of ezetimibe in pharmaceutical formulation. The solutions of standard and sample were prepared...Full Text Available
2008-03-01
UK PubMed Central (United Kingdom)
The objectives of this research are: (1) to assess selected formulation-relevant physical properties of several commercial Feverfew extracts, including flowability, hygroscopicity, compressibility and...Full Text Available
UK PubMed Central (United Kingdom)
The gelation kinetics of an in situ gelable hydrogel formulated from oxidized dextran (Odex) and N-carboxyethyl chitosan (CEC) were investigated rheologically. Both Schiff base...Full Text Available
2007-04-01
Hamiltonian formulation of the N=1 D=10 supergravity coupled to super Yang-Mills theory
Energy Technology Data Exchange (ETDEWEB)
The authors derive in full details the Hamiltonian formulation of the N = 1D = 10 supergravity coupled to super Yang-Mills theory. In particular, they present the explicit form of the first class constraints and compute the constraints gauge algebra.
1988-01-01
UK PubMed Central (United Kingdom)
Objectives:The study was planned to evaluate the efficacy and safety of Livwin (polyherbal formulation) in acute viral hepatitis.Materials...Full Text Available
2010-10-01
NASA Information Technology Requirement Main Menu
Headquarters Centrally-Funded Information Technology (IT) Resource Allocation .... Information Technology Policy Formulation Process ...
Demonstration/Validation of the TC-25 Donovan Blast ...
... During operations, the system successfully treated Phosgene (CG), chloropicrin (PS), a smoke-generating formulation based on hexachloroethane ...
2004-05-01
A Theory of Justified Reformulations
... A classic example is rewriting the missionaries and cannibals (M and C) problem [Ama68] phrased in terms of individuals into a formulation that is ...
1989-03-01
Scientific Electronic Library Online (English)
Abstract in english This paper presents an HP-Adaptive Procedure with Hierarchical formulation for the Boundary Element Method in 2-D Elasticity problems. Firstly, H, P and HP formulations are defined. Then, the hierarchical concept, which allows a substantial reduction in the dimension of equation system, is introduced. The error estimator used is based on the residual computation over each node inside an element. Finally, the HP strategy is defined and applied to two examples.
2002-03-01
Upholding the Convention on the Rights of the Child: A Quandary in Cyberspace
Put in place to protect the rights of the child, the Convention on the Rights of the Child is a set of non-negotiable standards. A core principle underpinning the Convention is the child's right to participate fully in social arenas and to access sources of social support without excessive interference. Juxtaposing this is the right of the child to be shielded from harm, abuse and exploitation. Over the past several decades the Internet has emerged as a fast and easily accessible medium for people to connect and communicate. While the Internet provides children with a source of support through chat rooms, online communities and social networking sites, just as equally it can expose vulnerable children to predatory and deviant individuals exacerbating the potential for harm. Upholding the Convention in cyberspace is a challenge. The Internet is not owned or regulated by any governing body and accountability is difficult to enforce. This article discusses some of the ...
2010-04-01
The uses and abuses of history: The end of the Cold War and Soviet collapse
British Library Electronic Table of Contents (United Kingdom)
In the by now extended debate about the end of the Cold War and its causes, very little attention has been paid to the role played by historical memory in helping shape the way policy-makers approached the collapse of the post-war order. As this article shows, many, if not most policy elites at the time, confronted the passing of the old world with a great degree of caution and trepidation; and one of the key reasons they did so, it is argued here, is because of their reading of the past. This reading, I go on to suggest, made many of them especially cautious and fearful when faced with great change. In the end of course these changes proved irresistible, and for liberals at least seemed to augur in more peaceful and prosperous times. However, as we shall see here, this unguarded optimism ...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Major depressive disorder and alcohol dependence are common and serious mental illnesses. There is a great interest in discovering useful treatments for both mood symptoms and alcohol abuse in those patients with depressive disorders and comorbid alcohol dependence. The primary purpose of this study was to evaluate the effectiveness and tolerability of mirtazapine for the treatment of patients with alcohol dependence comorbid with a depressive disorder in an open label, naturalistic multicentre treatment setting. The 17-item Hamilton Depression Rating Scale (HDRS), the Hamilton Anxiety Rating Scale (HARS) and the Clinical Global Impression-Severity (CGI-S) scale were measured at baseline and at weeks 4 and 8 for the assessment of treatment effectiveness. Alcohol craving was measured using ...
2006-01-01
Mining User Comment Activity for Detecting Forum Spammers in YouTube
Research shows that comment spamming (comments which are unsolicited, unrelated, abusive, hateful, commercial advertisements etc) in online discussion forums has become a common phenomenon in Web 2.0 applications and there is a strong need to counter or combat comment spamming. We present a method to automatically detect comment spammer in YouTube (largest and a popular video sharing website) forums. The proposed technique is based on mining comment activity log of a user and extracting patterns (such as time interval between subsequent comments, presence of exactly same comment across multiple unrelated videos) indicating spam behavior. We perform empirical analysis on data crawled from YouTube and demonstrate that the proposed method is effective for the task of comment spammer detection.
2011-01-01
Large (≥2cm) non-hypervascular nodules depicted on MRI in the cirrhotic liver: fate and implications
British Library Electronic Table of Contents (United Kingdom)
Aim To determine the fate and clinical implication of large (?2cm), non-hypervascular nodules depicted on magnetic resonance imaging (MRI) in the cirrhotic liver. Materials and methods In 21 patients with cirrhosis (14 hepatitis B, two ethanol abuse, four cryptogenic, one Wilson's disease), 25 large (?2cm in the longest dimension) non-hypervascular nodules were identified on dynamic MRI. The implications for diagnosis of the initial size, contour, and signal characteristics on MRI in addition to patients' age and cause of cirrhosis were assessed in our analysis. Results Twelve (75%) out of 16 lesions were malignant or potentially-malignant from 14 hepatitis B patients, while seven (78%) of the nine lesions from other patients were benign (p=0.016). The mean age of the patients who ha...
2008-01-01
Impact of Cannabis Use on Male Sexual Health
British Library Electronic Table of Contents (United Kingdom)
Abstract Introduction.- Cannabis (marijuana) is the most widely used illicit drug globally. Given the prevalence of nonprescription illicit drug abuse, there is a growing interest in the study of its potential effects on male sexual health. In this review, we discuss the effects of cannabis on male sexual health. Objective.- In this review, we discuss the effects of cannabis on male sexual health. Methods and Main Outcome Measure.- Critical review of scientific literature examining the impact of cannabis use on male sexual health. Results.- Studies examining the effects of cannabis use on male sexual function have been limited in both quality and quantity. Most results of these studies are conflicting and contradictory. While some did outline the beneficial effects of cannabis in enhancing...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
The replacement of lithium metal from the negative electrode of lithium batteries by a material allowing the reversible insertion of lithium ions is an undeniable commercial success. Carbon electrodes, generally called Li{sub x}C{sub 6}, are the most common type and allow to increase the service life of the battery, its charging fastness and its safety. The safety of such batteries is well known in normal conditions of use, but it has to be known also in any abusive condition of use, whatever is the charging state. The mastery of the phenomena that can occur requires a good knowledge of the kinetics of the exothermal chemical reactions involved. (J.S.) 8 refs.
1996-12-31
A Hamiltonian Formulation of the BKL Conjecture
The Belinskii, Khalatnikov and Lifshitz conjecture \\cite{bkl1} posits that on approach to a space-like singularity in general relativity the dynamics are well approximated by `ignoring spatial derivatives in favor of time derivatives.' In \\cite{ahs1} we examined this idea from within a Hamiltonian framework and provided a new formulation of the conjecture in terms of variables well suited to loop quantum gravity. We now present the details of the analytical part of that investigation. While our motivation came from quantum considerations, thanks to some of its new features, our formulation should be useful also for future analytical and numerical investigations within general relativity.
2011-01-01
Tachyons and theory of quasi-catastrophes
International Nuclear Information System (INIS)
The author discusses the formulation and application of the theory of quasi-catastrophes for the behaviour and properties of tachyons. This approach assists in the interpretation of experiments where tachyons may be involved. (W.D.L.).
British Library Electronic Table of Contents (United Kingdom)
The present study was carried out to exploit the feasibility of using polymeric nanosponges as an alternative carrier for targeting econazole nitrate (EN) to the skin through topical hydrogel formulation. Nanosponges prepared by emulsion solvent diffusion method were evaluated for various physicochemical parameters and in vitro drug release. The nanosponges of EN were discrete free flowing nanosized particles with perforated orange peel like morphology as visualized by SEM. The nanosponge formulated using PVA:EC (3:2) displayed highest in vitro release after 12 ?h in phosphate buffer (pH 6.8) that fitted matrix model. Selected nanosponge was formulated as Carbopol 934 NF hydrogel using varying concentrations of permeation enhancers propylene glycol and N-methyl-2-pyrrolidone. The EN nanosp...
2011-01-01
Optimizing efficacy of Amphotericin B through nanomodification
UK PubMed Central (United Kingdom)
The polyene antibiotic Amphotericin B (AMB) is one of the first therapeutic agents to be marketed commercially as nanosized formulations in which the drug is associated with lipids as liposomes or complexes....Full Text Available
2007-09-01
British Library Electronic Table of Contents (United Kingdom)
Environmental information has been described as central to the issues of solid waste management and disposal. This study investigated the availability and accessibility of environmental information to the solid waste policy formulators and implementors with regard to the media/channels used for disseminating environmental information to the public. A descriptive survey design was adopted for the study. A purposive sampling technique was used to select the sample and the method produced 205 respondents that consisted of 185 Policy Implementors and 20 Policy Formulators. A total of 147 cases were finally analyzed, which included 16 Policy Formulators (80% of total sample) and 131 Policy Implementors (71% of total sample). Data collected were analyzed using descriptive statistics such as perc...
2009-01-01
Homotopy Lie superalgebra in Yang-Mills theory
International Nuclear Information System (INIS)
The Yang-Mills equations are formulated in the form of generalized Maurer-Cartan equations, such that the corresponding algebraic operations are shown to satisfy the defining relations of homotopy Lie superalgebra.
2007-09-01
Exploration of Cold Extrusion for the Preparation of Enteric Minitablets of Isoniazid
UK PubMed Central (United Kingdom)
The objective of the present work was to formulate the enteric minitablets of isoniazid by cold extrusion method. The minitablets were prepared using isoniazid, hydroxylpropylmethylcellulose phthalate...Full Text Available
2008-05-01
... commercial material manufactured utilizing chlorinated hydrocarbons for the sulfonation of a long chain polystyrene to produce high ... ...
Effect of different formulations on tebuconazole residues in stone fruits
British Library Electronic Table of Contents (United Kingdom)
BACKGROUND: The correlation between pesticide residue levels and formulation of an active substance is often not considered, even if it is reasonable to expect some differences arising from behaviour during dilution and spraying, from adhesion to plant and from degradation. An experimental study to investigate the magnitude of tebuconazole residues as a function of different tebuconazole formulated products was carried out in Italy. The fungicide was applied as wettable powder (WP) and water-dispersible granule (WG) formulations to peach, plum, apricot and nectarine orchards, on four different sites. The fruit samples gained from the field trials were quantitatively analysed by gas chromatography with a nitrogen phosphorus detector (GC/NPD) for tebuconazole residues. RESULTS: Tebuconazole ...
2009-01-01
International Nuclear Information System (INIS)
We study the uniqueness of solutions of a semilinear elliptic problem obtained from an inverse formulation when the nonlinear terms of the equation are prescribed in a general class of real functions. The inverse problem arises in the modeling of the magnetic confinement of a plasma in a Stellarator device. The uniqueness proof relies on an L"#infinity# -estimate on the solution of an auxiliary nonlocal problem formulated in terms of the relative rearrangement of a datum with respect to the solution.
Non-uniqueness in conformal formulations of the Einstein constraints
Standard methods in non-linear analysis are used to show that there exists a parabolic branching of solutions of the Lichnerowicz-York equation with an unscaled source. We also apply these methods to the extended conformal thin sandwich formulation and show that if the linearised system develops a kernel solution for sufficiently large initial data then we obtain parabolic solution curves for the conformal factor, lapse and shift identical to those found numerically by Pfeiffer and York. The implications of these results for constrained evolutions are discussed.
2006-01-01
Energy Technology Data Exchange (ETDEWEB)
The optimization of ethylene furnace operations using cfd-based simulations has been addressed. The optimization problems have been cast into various formulations: the Multidisciplinary feasible (MDF) approach, the All-At-Once (AAO) approach and the Individual discipline feasible (IDF) approach. These approaches mainly differ in their handling of the state equations as constraints, and hence some of the formulations place restrictions on the methods used to solve the state equations.
1999-08-31
Explosive acceleration of liquid from a cylindrical container using the implosive technique
British Library Electronic Table of Contents (United Kingdom)
Tthe acceleration of a liquid from a cylindrical container by the products of instantaneous detonation of a superimposed explosive charge (implosion method) is studies numerically in a two-dimensional formulation. Analytical formulas for the asymptotic velocities of liquid expansion and acceleration of the container body were obtained using numerical calculations in a one-dimensional approximation. The effect of the fracture of the body on the velocity of liquid expansion was studied in a two-dimensional formulation.
2011-01-01
Computer Algebra meets Finite Elements: an Efficient Implementation for Maxwell's Equations
We consider the numerical discretization of the time-domain Maxwell's equations with an energy-conserving discontinuous Galerkin finite element formulation. This particular formulation allows for higher order approximations of the electric and magnetic field. Special emphasis is placed on an efficient implementation which is achieved by taking advantage of recurrence properties and the tensor-product structure of the chosen shape functions. These recurrences have been derived symbolically with computer algebra methods reminiscent of the holonomic systems approach.
2011-01-01
Linear augmented plane wave method for self-consistent calculations
International Nuclear Information System (INIS)
O.K. Andersen has recently introduced a linear augmented plane wave method (LAPW) for the calculation of electronic structure that was shown to be computationally fast. A more general formulation of an LAPW method is presented here. It makes use of a freely disposable number of eigenfunctions of the radial Schroedinger equation. These eigenfunctions can be selected in a self-consistent way. The present formulation also results in a computationally fast method. It is shown that Andersen's LAPW is obtained in a special limit from the present formulation. Self-consistent test calculations for copper show the present method to be remarkably accurate. As an application, scalar-relativistic self-consistent calculations are presented for the band structure of FCC lanthanum. (author).
British Library Electronic Table of Contents (United Kingdom)
Vaccine-mediated prevention of primary HIV-1 infection at the heterosexual mucosal portal of entry may be facilitated by highly optimised formulations or drug delivery devices for intravaginal (i.vag) immunization. Previously we described hydroxyethylcellulose (HEC)-based rheologically structured gel vehicles (RSVs) for vaginal immunization of an HIV-1 vaccine candidate, a soluble recombinant trimeric HIV-1 clade-C envelope glycoprotein designated CN54gp140. Here we investigated the efficacy of lyophilized solid dosage formulations (LSDFs) for prolonging antigen stability and as i.vag delivery modalities. LSDFs were designed and developed that upon i.vag administration they would reconstitute with the imbibing of vaginal fluid to mucoadhesive, site-retentive semi-solids. Mice were immunize...
2011-01-01
Formulation of multi-component explosives
Energy Technology Data Exchange (ETDEWEB)
In a method for formulating a multi-component explosive composition, the steps are described comprising: (a) providing a defined body of unconsolidated particulate aluminum fuel granules having an average particle size within the range of 1/64-1/4 inch and an average bulk density within the range of 0.2-1.0 gm/cc; (b) providing a phase oxidizing liquid; and (c) flooding said body of particulate aluminum fuel of step (a) with the oxidizing liquid of step (b) to provide a bulk density of said mixture of oxidizing liquid and particulate aluminum fuel mass within the range of 1.2-1.7 gm/cc and provide an explosive formulation detonable at 20 C in a diameter of 4 inches by a one pound pentolite booster.
1993-07-13
Effects of pork/beef levels and various casings on quality properties of semi-dried jerky
British Library Electronic Table of Contents (United Kingdom)
The aim of this study was to investigate the effects of pork/beef levels and the casings on the quality properties of semi-dried jerky. The pork/beef levels in the four test formulations were as follows: T-1 (pork: beef=100:0), T-2 (95:5), T-3 (90:10), and T-4 (80:20). After tumbling for 30min with curing solution, the cured meats were stuffed into natural sheep casings, collagen casings, or cellulose casings, and then dried. The restructured jerky with cellulose casing had the lowest water content and the highest protein content, with no significant differences between various formulations. There were no significant differences among all formulations with regard to pH and total microbial counts, and jerky with cellulose casing had the lowest value of water activity. The processing yields ...
2008-01-01
Characterisation and use of biomass fly ash in cement-based materials
British Library Electronic Table of Contents (United Kingdom)
This paper presents results about the characterisation of the biomass fly ashes sourced from a thermal power plant and from a co-generation power plant located in Portugal, and the study of new cement formulations incorporated with the biomass fly ashes. The study includes a comparative analysis of the phase formation, setting and mechanical behaviour of the new cement-fly ash formulations based on these biomass fly ashes. Techniques such as X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), thermal gravimetric and differential thermal analysis (TG/DTA), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and environmental scanning electron spectroscopy (ESEM) were used to determine the structure and composition of the formulations. Fly ash F1 from the t...
2009-01-01
We introduce a new formulation of asset trading games in continuous time in the framework of the game-theoretic probability established by Shafer and Vovk (2001). In our formulation, the market moves continuously but an investor trades in discrete times, which can depend on the past path of the market. We prove that an investor can essentially force that the asset price path behaves with the variation exponent exactly equal to two. Our proof is based on embedding high-frequency discrete time games into the continuous time game and the use of the Bayesian strategy of Kumon, Takemura and Takeuchi (2007b) for discrete time coin-tossing games. We also clarify that the main growth part of the investor's capital processes is lucidly described by the information quantities, which are derived from the Kullback-Leibler information with respect to the empirical fluctuation of the asset price.
2007-01-01
Material related to routine as well as sensitive aspects of parent/day care center relationships is presented in this training module, one of a series providing staff development information for programs operated for dependents of military personnel. The module offers a brief discussion of ways caregivers can help parents feel at ease about leaving their children in child care and presents a set of multiple-choice skill-building exercises for effectively working with parents. Exercises focus on various topics, including how parents can be approached when their child may have a health problem, when child abuse or neglect is suspected, and when parental cooperation is needed to stop a child's undesirable or disruptive behavior. Exercises are also devoted to the questions of whether or not caregivers should act as advisors to parents or tell parents about their child's behavior at the center. Concluding exercises indicate how caregivers can handle parent requests for ...
1982-04-01
International Nuclear Information System (INIS)
Pulmonary clearance of an aerosol of "9"9Tc"m DTPA was measured in 21 non-smoking AIDS and pneumocystosis patients. The results were compared with those of pulmonary scintiscanning with gallium. All the patients exhibited increased clearance, evidence of a considerable alteration in alveolar permeability. This increase was also observed in patients with normal chest X-rays and normal blood gases. The average clearance in these patients was 6 #+-# 2% min"-"1 as compared with a normal 1.1 #+-# 0.3% min"-"1. Conversely, only four out of eight patients with normal chest X-rays had abnormal gallium scans. Clearance returned to normal after recovery. Measurement of DTPA clearance appears to be a very sensitive indicator for the detection and follow-up of pneumocystosis. However, it is not very specific since it can be increased by tobacco poisoning, drug abuse and the presence of lymphocytic alveolitis. An examination with normal findings can therefore exclude the ...
1988-08-15
Anxiety is a common symptom during ethanol withdrawal contributing to its continuous abuse and alcoholism. Ethanol withdrawal in rats produces an interoceptive discriminative stimulus (IDS) similar to that produced by the anxiogenic drug pentylenetetrazol (PTZ). This stimulus peaks at 12 hours after last dose of ethanol and thereafter the IDS is detected for several days (protracted withdrawal) by sensitization to a probe drug. previously, the authors have shown that during the protracted withdrawal, the IDS is enhanced by GABA receptor antagonists suggesting alteration of brain GABA systems. This report provides further evidence that chronic ethanol alters GABAergic systems. Rats were trained to discriminate PTZ (20 mg/kg, ip) from saline. Diazepam, pentobarbital and phenobarbital blocked the PTZ-IDS dose dependently. Ethanol, 4.5% w/v, was then given in a nutritionally complete diet for a week. On termination of the ethanol diet, rats exhibited signs and symptoms ...
1990-02-26
Is My Armor Straight: A Year in the Life of a University President.
A personal account of Richard Berendzen's life as president of The American University (AU) in Washington, D.C. during the 1983-1984 academic year is presented in diary form. The account describes his interactions with faculty, students, administrators, and people outside the university to further the goals of the institution. In the year prior to the diary entries, enrollments at AU had dropped unexpectedly while tuition had not been raised to make up for the shortfall. There were empty beds of former students who faced economic pressures. A union protested AU's consequent firing of its custodians and its contracting with an independent custodial firm, which employed primarily blacks as custodians. The issue of racism surfaced when students and faculty supported demonstrators. Since AU has no wholly assured flow of applicants or donors, Berendzen recognized that to improve, or even to maintain, the relative position of AU, he had to become not only its pedagogical leader but also a ...
1986-01-20
British Library Electronic Table of Contents (United Kingdom)
Summary Background Systematic screening for liver fibrosis in heavy-drinking patients is a challenge. Aims To assess Fibroscan for non-invasive diagnosis of asymptomatic liver fibrosis in alcohol abuse patients, to determine diagnostic liver stiffness cut-off values and to compare performance of Fibroscan with seven non-invasive laboratory tests. Methods One hundred and three alcoholic patients were studied. Liver fibrosis was staged by METAVIR system. Fibroscan, Fibrotest, Fibrometer, Hepascore, APRI, PGA, PGAA and hyaluronic acid tests were performed. Liver stiffness cut-offs were determined using receiver-operating characteristic (ROC) curves. Results Liver stiffness was correlated with fibrosis (r = 0.72, P < 0.014), with median at 5.7, 6.3, 8.4, 15 and 47.3 kPa for F0 (n = 8), F1 (n =...
2008-01-01
A major QTL on chromosome 11 influences psychostimulant and opioid sensitivity in mice
British Library Electronic Table of Contents (United Kingdom)
The identification of genes influencing sensitivity to stimulants and opioids is important for determining their mechanism of action and may provide fundamental insights into the genetics of drug abuse. We used a panel of C57BL/6J (B6; recipient)x A/J (donor) chromosome substitution strains (CSSs) to identify quantitative trait loci (QTL) for both open field activity and sensitivity to the locomotor stimulant response to methamphetamine (MA). Mice were injected with saline (days 1 and 2) and MA (day 3; 2 mg/kg i.p.). We analyzed the total distance traveled in the open field for 30 min following each injection. CSS-8, -11 and -16 showed reduced MA-induced locomotor activity relative to B6, whereas CSS-10 and -12 showed increased MA-induced locomotor activity. Further analysis focused on CSS...
2009-01-01
UK PubMed Central (United Kingdom)
1. The antihypertensive efficacy and tolerability of a low dose combination of the angiotensin converting enzyme inhibitor ramipril (2.5 mg) and the extended release formulation of the dihydropyridine...Full Text Available
1993-10-01
UK PubMed Central (United Kingdom)
AIMTo compare a test version of HFA fluticasone/salmeterol (FP/SM) combination inhaler (Neolab, UK) with the reference product Seretide (GlaxoSmithKline, UK).METHODSAn...Full Text Available
2010-06-01
Silica-Based Nanoparticle Uptake and Cellular Response by Primary Microglia
UK PubMed Central (United Kingdom)
BackgroundSilica nanoparticles (SiNPs) are being formulated for cellular imaging and for nonviral gene delivery in the central nervous system (CNS), but it is unclear what potential...Full Text Available
2010-05-01
Relative toxicities of pure propylene and ethylene glycol and formulated deicers on plant species
Energy Technology Data Exchange (ETDEWEB)
Propylene and ethylene glycol deicers are commonly used at airports in the US and other countries to remove and retard the accumulation of snow and ice on aircraft. Deicers may not only enter water bodies without treatment, due to excessive storm-related flow, but also may expose terrestrial organisms to high concentrations through surface runoff. Most available toxicity data are for aquatic vertebrates and invertebrate species; this study examined effects on terrestrial and aquatic plants. Terrestrial plant species included both a monocot (rye grass, Lolium perenne) and a dicot (lettuce, Lactuca saliva). Aquatic species included a single cell alga (Selenastrum capricomutum), and an aquatic macrophyte (duckweed, Lemna minor). Glycol deicers were obtained in the formulated mixtures used on aircraft. Pure ethylene and propylene glycol were obtained from Sigma{reg_sign}. Parameters measured included germination, root and shoot length, survival, and growth. ...
1994-12-31
Quaternionic formulation for electromagnetic-field equations
Energy Technology Data Exchange (ETDEWEB)
The quaternionic formalism for subluminal field equations (Maxwell's equations) and its interrelationship with complex superluminal Lorentz transformations have been given and it has been shown that the quaternionic forms of relativistic equations describe tachyons.
1983-07-02
UK PubMed Central (United Kingdom)
The main aim of the present study was to evaluate potential of ternary complexation (comprising of drug, cyclodextrin and polymer) as an approach for taste masking. For this purpose famotidine with...Full Text Available
UK PubMed Central (United Kingdom)
BackgroundLarviciding is a key strategy used in many vector control programmes around the world. Costs could be reduced if larvicides could be manufactured locally. The potential...Full Text Available
Geometrical Symmetry in Symmetric Galerkin BEM.
We consider a symmetric boundary integral formulation associated with a mixed boundary value problem defined on a domain Omega is an element of the set of real numbers(2) with piecewise smooth boundary Gamma. We assume that Omega is mapped onto itself by ...
2001-01-01
Extended-release Trazodone in Major Depressive Disorder
UK PubMed Central (United Kingdom)
Objective: To investigate the efficacy, safety, and clinical benefit of a once-daily formulation of trazodone (Trazodone Contramid® OAD) in the treatment of major depressive...Full Text Available
UK PubMed Central (United Kingdom)
Inhaled corticosteroids (ICS) are often prescribed as first-line therapy for patients with asthma Despite their efficacy and improved safety profile compared with oral corticosteroids, the potential...Full Text Available
UK PubMed Central (United Kingdom)
Hexachlorocyclohexane (HCH) has been used extensively against agricultural pests and in public health programs for the control of mosquitoes. Commercial formulations of HCH consist of a mixture of four...Full Text Available
2002-12-01
Camouflage Dispenser, Helicopter Mounted.
New and improved camouflage techniques which will enhance field security are required by Department of Army personnel. The report contains the results of tests, formulations and the operational characteristics of the 73E01-1A dispenser. Various tests (air...
1972-01-01
UK PubMed Central (United Kingdom)
BackgroundIn 1988, the SPILI project was established in order to evaluate the cardiovascular disease (CVD) risk profile of the inhabitants of Spili, in rural Crete, Greece. The first...Full Text Available
UK PubMed Central (United Kingdom)
From Toki-shakuyaku-san, an herbal formulation for “cleansing stagnated blood,” a key gene regulatory compound was purified and identified through a screening based on DNA microarray...Full Text Available
2007-12-15
A model for the kinetics of homotypic cellular aggregation under static conditions.
UK PubMed Central (United Kingdom)
We present the formulation and testing of a mathematical model for the kinetics of homotypic cellular aggregation. The model considers cellular aggregation under no-flow conditions as a two-step process....Full Text Available
1997-01-01
Torsion of moderately thick hollow tubes with polygonal shapes
British Library Electronic Table of Contents (United Kingdom)
A simple formulation is presented for torsion analysis of hollow tubes with polygonal shapes. Thicknesses of segments of cross section can be different. Governing equations in term of Prandtl's stress function are used to derive the formulas. The derived formulas are so simple that computations can be carried out with a pocket calculator. Several examples are presented to show the accuracy and efficiency of the formulation. The obtained results are verified by accurate finite element solutions. It will be seen that the derived formulas can be useful for analysis of thin-walled and moderately thick-walled hollow tubes.
2007-01-01
The full order weak schemes of the Langevin simulations
Energy Technology Data Exchange (ETDEWEB)
New partial differential equations (PDEs) for the full order weak schemes of the Langevin simulations are formulated. They are solved recursively in full order series solutions with respect to {radical}(t) (the full order weak Taylor schemes). Arbitrariness involved in the solutions is analyzed and clarified in detail. Specific solutions within some orders are presented as examples of the weak Taylor schemes. These PDEs and their solutions will serve for further developments of efficient higher order Runge-Kutta-like schemes. The similar formulation is possible for the imaginary time Hamiltonian evolution kernels as well. (orig.). 9 refs.
1998-04-01
Optimization of inspection and replacement period by using Bayesian statistics
International Nuclear Information System (INIS)
This study describes the formulations to optimize the time interval of inspections and/or replacements of equipment/parts taking into account the probability density functions (PDF) for failure rates and parameters of failure distribution functions (FDF) and evaluates the optimized results of these time intervals using our formulations by comparing with those using only representative values of failure rates and the parameters of FDF instead of using these PDFs. The PDFs are obtained with Bayesian method and the representative values are obtained with likelihood estimation method. However, any significant difference is not observed between both optimized results within our preliminary calculations. (author)
2006-07-01
Evaluation of Phase II glass formulations for vitrification of Hanford Site low-level waste
Energy Technology Data Exchange (ETDEWEB)
A vendor glass formulation study was carried out at Pacific Northwest Laboratory (PNL), supporting the Phase I and Phase II melter vendor testing activities for Westinghouse Hanford Company. This study is built upon the LLW glass optimization effort that will be described in a separate report. For Phase I vendor melter testing, six glass formulations were developed at PNL and additional were developed by Phase I vendors. All the doses were characterized in terms of viscosity and chemical durability by the 7-day Product Consistency Test. Twelve Phase II glass formulations (see Tables 3.5 and 3.6) were developed to accommodate 2.5 wt% P{sub 2}O{sub 5} and 1.0 wt% S0{sub 3} without significant processing problems. These levels of P{sub 2}O{sub 5} and SO{sub 3} are expected to be the highest possible concentrations from Hanford Site LLW streams at 25 wt% waste loading in glass. The Phase H compositions ...
1996-03-01
International Nuclear Information System (INIS)
The effect of addition of rosemary and oregano extracts on the sensory quality of irradiated beef burger was investigated. Batches of beef burgers were prepared with 400 ppm of rosemary or oregano extract and a group prepared with 200 ppm of synthetic butyl-hydroxytoluene (BHT)/butyl-hydroxy-anisol (BHA) was used as a control. Half of each formulation was irradiated at the maximum dose allowed for frozen meat (7 kGy). Samples were kept under frozen conditions (-20 deg. C) during the whole storage period, including during irradiation. Two analyses were performed after 20 and 90 days to verify the influence of the addition of the different types of antioxidants and the effect of irradiation and storage time on the acceptance of the product. Thirty-three and thirty-four untrained panelists were invited to participate in the first and second test, respectively. A structured hedonic scale ranging from 1 to 9 points was used in both analyses. BHT/BHA ...
2009-04-01
Production of bone cement composites: effect of fillers, co-monomer and particles properties
International Nuclear Information System (INIS)
Artificial bone cements (BCs) based on poly(methyl methacrylate) (PMMA) powders and methyl methacrylate (MMA) liquid monomer also present in their formulation small amounts of other substances, including a chemical initiator compound and radiopaque agents. Because inadequate mixing of the recipe components during the manufacture of the bone cement may compromise the mechanical properties of the final pieces, new techniques to incorporate the fillers into the BC and their effect upon the mechanical properties of BC pieces were investigated in the present study. PMMA powder composites were produced in situ in the reaction vessel by addition of X-ray contrasts to the reacting MMA mixture. It is shown that this can lead to much better mechanical properties of test pieces, when compared to standard bone cement formulations, because enhanced dispersion of the radiopaque agents can be achieved. Moreover, it is shown that the addition of hydroxyapatite ...
Planning logistics operations in the oil industry
International Nuclear Information System (INIS)
In this paper we apply stochastic programming modelling and solution techniques to planning problems for a consortium of oil companies. A multiperiod supply, transformation and distribution scheduling problem - the Depot and Refinery Optimization Problem (DROP) - is formulated for strategic or tactical level planning of the consortium's activities. This deterministic model is used as a basis for implementing a stochastic programming formulation with uncertainty in the product demands and spot supply costs (DROPS), whose solution process utilizes the deterministic equivalent linear programming problem. We employ our STOCHGEN general purpose stochastic problem generator to 'recreate' the decision (scenario) tree for the unfolding future as this deterministic equivalent. To project random demands for oil products at different spatial locations into the future and to generate random fluctuations in their future prices/costs a stochastic input data ...
Matching the needs of a nation: The strategic roles of indicators for decisionmaking
Energy Technology Data Exchange (ETDEWEB)
Indicators are important tools for communicating and making accessible scientific and technical information to policymakers and the general public. They therefore play an important role in transforming information into action. Worldwide, many initiatives are underway to construct indicators for a variety of purposes, including those for reporting on sustainable development. This paper briefly describes the attempts made so far, but stresses that the users of the indicators should play a greater role in indicator construction. In developing countries, a substantial lack of data has meant that specific policy formulation may develop without adequate technical input. In developed countries also, data gaps may hinder policy formulation, implementation, and evaluation. However, the development of indicators as tools to assist in the management of hazardous wastes and toxic chemicals is still in the early stages of formulation. A ...
1996-12-31
Efficient higher order nodal finite element formulations for neutron multigroup diffusion equations
Energy Technology Data Exchange (ETDEWEB)
Several polynomial finite elements of nodal type are introduced that should lead to convergence of O(h{sup 3}) in the L{sup 2} norm. Two of these methods are new and are expected to achieve the same orders of convergence with fewer parameters than the third method. They are applied to the one-group diffusion equation under different formulations, namely, several versions (with or without reduced and transverse integrations) of the primal and the mixed-hybrid formulations. Convergence rates are checked for a model problem with an analytical solution. Two of these methods exhibit superconvergence phenomena [O(h{sup 4}) instead of O(h{sup 3})], a fact that can be explained heuristically. The most promising method, with only five parameters per cell, turns out to yield only O(h{sup 2}) in its most algebraically efficient versions, while it has the potential of O(h{sup 3}) convergence rates. Again, an explanation is given for this behavior and a ...
1996-09-01
Effects of extreme pressure additive chemistry on rolling element bearing surface durability
Energy Technology Data Exchange (ETDEWEB)
Lubricant additives have been known to affect rolling element bearing surface durability for many years. Tapered roller bearings were used in fatigue testing of lubricants formulated with gear oil type additive systems. These systems have sulfur- and phosphoruscontaining compounds used for gear protection as well as bearing lubrication. Several variations of a commercially available base additive formulation were tested having modified sulfur components. The variations represent a range of ''active'' extreme pressure (EP) chemistries. The bearing fatigue test results were compared with respect to EP formulation and test conditions. Inner ring near-surface material in selected test bearings was evaluated on two scales: the micrometer scale using optical metallography and the nanometer scale using transmission electron microscopy (TEM). Focused-ion beam (FIB) techniques were used for TEM ...
2007-08-01
The interaction of accretion disks with the magnetospheres of young stars can produce X-winds and funnel flows. With the assumption of axial symmetry and steady state flow, the problem can be formulated in terms of quantities that are conserved along streamlines, such as the Bernoulli integral (BI), plus a partial differential equation (PDE), called the Grad-Shafranov equation (GSE), that governs the distribution of streamlines in the meridional plane. The GSE plus BI yields a PDE of mixed type, elliptic before critical surfaces where the flow speed equals certain characteristic wave speeds are crossed and hyperbolic afterward. The computational difficulties are exacerbated by the locations of the critical surfaces not being known in advance. To overcome these obstacles, we consider a variational principle by which the GSE can be attacked by extremizing an action integral, with all other conserved quantities of the problem explicitly included as part of the overall ...
2007-01-01
Energy Technology Data Exchange (ETDEWEB)
Although incompressible fluid flows can be regarded as a particular case of a general problem, numerical methods and the mathematical formulation aimed to solve compressible and incompressible flows have their own peculiarities, in such a way, that it is generally not possible to attain both regimes with a single approach. In this work, we start from a typically compressible formulation, slightly modified to make use of pressure variables and, through augmenting the stabilising parameters, we end up with a simplified model which is able to deal with a wide range of flow regimes, from supersonic to low speed gas flows. The resulting methodology is flexible enough to allow for the simulation of liquid flows as well. Examples using conservative and pressure variables are shown and the results are compared to those published in the literature, in order to validate the method. (author)
2004-11-15
The work of the CONRAD task group 5.2: research studies on biokinetic models.
The objective of this Task Group is the coordination of research studies on biokinetic models and the evaluation of the implications of new biokinetic models on dose assessment and safety standards. For this the new ICRP models, which will be used for a revision of ICRP Publications 30, 54, 68 and 78, are implemented into six different computer codes in five European countries and quality assured by intercomparison procedures. The work has started with the implementation of the new ICRP Alimentary Tract Model. New systemic models and the new NCRP wound model will follow. The work also includes the evaluation of experimental results in terms of formulation by the new model structures and a quality assurance of model formulation. PMID:17556343
2007-06-07
Survival of-Escherichia coli-O157:H7 in Meat Product Brines Containing Antimicrobials
British Library Electronic Table of Contents (United Kingdom)
Abstract:- Brine solution injection of beef contaminated with-Escherichia coli-O157:H7 on its surface may lead to internalization of pathogen cells and/or cross-contamination of the brine, which when recirculated, may serve as a source of new product contamination. This study evaluated survival of-E. coli-O157:H7 in brines formulated without or with antimicrobials. The brines were formulated in sterile distilled water (simulating the composition of freshly prepared brines) or in a nonsterile 3% meat homogenate (simulating the composition of recirculating brines) at concentrations used to moisture-enhance meat to 110% of initial weight, as follows: sodium chloride (NaCl, 5.5%) + sodium tripolyphosphate (STP, 2.75%), NaCl + sodium pyrophosphate (2.75%), or NaCl + STP combined with potassium ...
2011-01-01
Reliability analysis of the downstream face of a rockfill dam. Introductory work
Energy Technology Data Exchange (ETDEWEB)
Reliability analysis is now being used to a large extent for several civil engineering structures. Such analysis has not been used for rockfill dams, the most common dams in Norway. Following work on reliability analysis for breakwaters, reliability analysis was then used to investigate the ability of the stone material on the upstream face of a rockfill dam to withstand wind generated waves. An attempt is made to follow up this work by including discharge overtopping on a rockfill dam in a reliability analysis. This report primarily goes through previous work on the required weight of protective stones on the downstream face of the dam for specified discharges over the dam and also deals with the probability formulation of extreme floods. A failure function with partial coefficients is formulated. But for reasons of economy the calibration of the partial coefficients remains for a next phase of the project. 14 refs., 17 figs.
1995-02-01
Preparation and evaluation of a novel glass-ionomer cement with antibacterial functions
British Library Electronic Table of Contents (United Kingdom)
Objective.The objective of this study was to use the newly synthesized poly(quaternary ammonium salt) (PQAS)-containing polyacid to formulate the light-curable glass-ionomer cements and study the effect of the PQAS on the compressive strength and antibacterial activity of the formed cements.Materials and methods.The functional QAS and their constructed PQAS were synthesized, characterized and formulated into the experimental high-strength cements. Compressive strength (CS) and Streptococcus mutans viability were used to evaluate the mechanical strength and antibacterial activity of the cements. Fuji II LC cement was used as control. The specimens were conditioned in distilled water at 37 degrees C for 24 h prior to testing. The effects of the substitute chain length, loading as well as gra...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
Purpose The primary objective of this sub-study, undertaken as an extension to the previously reported phase-I study, was to explore the feasibility, tolerability and pharmacokinetics (PK) of belinostat when administered by the oral route. Preliminary pharmacodynamic (PD) studies were also performed to enable comparison of the biological effects of the oral and intravenous formulations. Patients and methods Oral belinostat was administered in a range of doses and schedules (once, twice or thrice daily), on either day 1 or days 1?5, of the second or a subsequent treatment cycle in 15 patients who were included in the phase-I trial of intravenous belinostat. Serial blood samples were collected for PK and PD (histone acetylation) analyses, and the results compared with corresponding analyses ...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
We consider the dynamics towards the initial singularity of Bianchi type IX vacuum and orthogonal perfect fluid models with a linear equation of state. Surprisingly few facts are known about the 'Mixmaster' dynamics of these models, while at the same time most of the commonly held beliefs are rather vague. In this paper, we use Mixmaster facts as a base to build an infrastructure that makes it possible to sharpen the main Mixmaster beliefs. We formulate explicit conjectures concerning (i) the past asymptotic states of type IX solutions and (ii) the relevance of the Mixmaster/Kasner map for generic past asymptotic dynamics. The evidence for the conjectures is based on a study of the stochastic properties of this map in conjunction with dynamical systems techniques. We use a dynamical systems formulation, since this approach has so far been the only successful path to obtain theorems, but we also make comparisons with the ...
2009-04-07
Lie algebra cohomology and N=2 SCFT based on the GKO construction
International Nuclear Information System (INIS)
We interpret N=2 superconformal field theories (SCFTs) formulated by Kazama and Suzuki via Goddard-Kent-Olive (GKO) construction from a viewpoint of the Lie algebra cohomology theory for the affine Lie algebra. We determine the cohomology group completely in terms of a certain subset of the affine Weyl group. We find that this subset describing the cohomology group can be obtained from its classical counterpart by the action of the Dynkin diagram automorphisms. Some algebra automorphisms of the N=2 superconformal algebra are also formulated. Utilizing the algebra automorphisms, we study the field identification problem for the branching coefficient modules in the GKO-construction. Also the structure of the Poincare polynomial defined for each N=2 theory is revealed. (orig.).
1991-01-01
Influence of the Different Oils Used in Dough Formulation on the Lipid Fraction of-Taralli
British Library Electronic Table of Contents (United Kingdom)
Abstract:- An experimental investigation was carried out to evaluate the quality of-taralli-as a function of the type of oil used in their dough formulation. To this end, 4 types of oil (extra virgin olive oil, olive oil, olive-pomace oil, and refined palm oil) were utilized to prepare-taralli-to investigate on the lipid fraction degradation and evaluate the-taralli-acceptability by consumers. The data obtained pointed out that-taralli-manufactured with extra virgin olive oil were significantly more appreciated than those made with refined oils due to their visual appearance and odor. Moreover, with respect to the other kinds of oil, the use of extra virgin olive oil led to significantly lower values (P-< 0.05) of specific absorption at 232 and 270 nm (K232 and K270, respectively) and of t...
2011-01-01
Energy Technology Data Exchange (ETDEWEB)
A nanosuspension of magnetically tagged metronidazole was developed by the solvent displacement method coupled with ultrasonication and was evaluated for its physicochemical properties. The drug release from metronidazole magnetic nanosuspension at pH 1.2 and 7.0 shows maximum correlation coefficient for zero order and Higuchi model, respectively. The anthelmintic activity of the formulated metronidazole magnetic nanosuspension was evaluated on Indian earthworms (Pheretima poi). Metronidazole magnetic nanosuspension at a dose of 10 and 50 mg/ml shortened by 31% and 34%, respectively, the mean time to death of the earthworms when compared against a non-magnetic metronidazole suspension. Thus, the developed metronidazole magnetic nanosuspension showed potent, controlled and targeted drug action and might be a good therapeutic avenue in combating infectious GI disorders.
2009-05-15
Evaluation of quality of alkylsalicylate additives with high content of active substance
Energy Technology Data Exchange (ETDEWEB)
This article describes the chemical preparation of petroleum additives of the MASK type from samples of concentrated alkylsalicylic acids. The obtained additives contain high contents of calcium alkylsalicylate and respective total alkalinities of 156, 131, and 130 mg KOH/g. Sodium alkylsalicylate concentrates, obtained in the form of an aqueous acetone solution, were converted to alkylsalicylic acids by interaction with hydrochloric acid. The solvent was removed from the upper and lower layers by distillation, and the resulting products were analyzed by liquid chromatography. Service tests were performed on a model formulation of the additive in M-11 oil in a Petter AV-1 test stand unit in comparison with commercial MASK additive. The results indicate that the model additive formulation gives approximately the same corrected piston fouling ratings as the commercial additive.
1984-09-01
Electron cyclotron resonance heating and current drive
Energy Technology Data Exchange (ETDEWEB)
A brief summary of the theory and experiments on electron- cyclotron heating and current drive is presented. The general relativistic formulation of wave propagation and linear absorption is considered in some detail. The O-mode and the X-mode for normal and oblique propagation are investigated and illustrated by several examples. The experimental verification of the theory in T-10 and D- III-D is briefly discussed. Quasilinear evolution of the momentum distribution and related applications as, for instance, non linear wave, damping and current drive, are also considered for special cases of wave frequencies, polarization and propagation. In the concluding section we present the general formulation of the wave damping and current drive in the absence of electron trapping for arbitrary values of the wave frequency. (Author) 13 refs.
1992-07-01
Building drought management capacity in the Mekong River basin
British Library Electronic Table of Contents (United Kingdom)
Over the past decades the Mekong River basin has experienced several droughts, the most recent of which occurred in the hydrological year 2004/2005. Impacts extended across agriculture, forestry, water resources, supply, industry, transport and the environment. In early 2006, the Mekong River Commission Secretariat initiated close consultations with the MRC member states Cambodia, Lao PDR, Thailand and Vietnam, aiming at the formulation of a common Drought Management Programme, which would enhance the existing drought management capacity and ensure effective support. This paper draws attention to the programme formulation process. It shows how national capacity needs were assessed and synthesized into a basin-wide capacity development programme. The paper concludes that in the context of i...
2008-01-01
A simple model for explosives formulation
Energy Technology Data Exchange (ETDEWEB)
A simple model based on surface chemistry is developed, based an simple concepts of contact angle, wetting and spreading. Results of the modeling can be stated by two simplified rules of thumb'': (1) A liquid will spread on the surface of a solid if the surface tension of the liquid is lose than the surface free energy of the solid, and (2) The liquid having the surface tension nearest that of the solid will preferentially wet the surface of the solid. These two rules can then be used to define the parameters that constitute a process for formulating a plastic bonded explosive (PBX), which is a crystalline high-explosive material coated with a small amount of plastic polymeric material (the binder). The PBX then can be pressed to a high density, and machined to a specific shape. The pressed and machined explosive material can then be used in a physics experiment to study fundamental properties of either the explosive or some other material.
1993-01-01
A simple model for explosives formulation
Energy Technology Data Exchange (ETDEWEB)
A simple model based on surface chemistry is developed, based an simple concepts of contact angle, wetting and spreading. Results of the modeling can be stated by two simplified ``rules of thumb``: (1) A liquid will spread on the surface of a solid if the surface tension of the liquid is lose than the surface free energy of the solid, and (2) The liquid having the surface tension nearest that of the solid will preferentially wet the surface of the solid. These two rules can then be used to define the parameters that constitute a process for formulating a plastic bonded explosive (PBX), which is a crystalline high-explosive material coated with a small amount of plastic polymeric material (the binder). The PBX then can be pressed to a high density, and machined to a specific shape. The pressed and machined explosive material can then be used in a physics experiment to study fundamental properties of either the explosive or some other material.
1993-04-01
British Library Electronic Table of Contents (United Kingdom)
Disodium phenyldibenzimidazole tetrasulfonate (PDT) is a new organic UV filter with hydrophilic properties used in modern sunscreen spray formulations. The aim of this work was to develop and validate an analytical method that can be used to study skin absorption of PDT from sunscreens. Results obtained in vitro for human skin showed a low level of absorption. The proposed in vitro method employs a diffusion cell. Sunscreen lotion was applied onto pretreated human skin, which was then placed in the cell. PDT was collected in a receptor liquid, the surface of which was in contact with the skin. The solutions obtained were diluted appropriately and analyzed by liquid chromatography without any interference. The analytical features of chromatographic determination with fluorimetic detection w...
2006-01-01
A New Spin Foam Model for 4d Gravity
Starting from the Plebanski formulation of gravity as a constrained BF theory we propose a new spin foam model for 4d Riemmanian quantum gravity that generalises the well-known model of Barrett-Crane and resolves the ultralocality problem that this model is known to possess. It is well known that the BF formulation of 4d gravity possesses two sectors: one corresponding to gravity and the other topological. The model presented here is shown to give a quantisation of the gravitational sector. The present model is dual to the recently proposed spin foam model of Engle et al. which, we show, corresponds to the topological sector of the theory. One important outcome of our approach is that it also allow us to introduce the Immirzi parameter into the framework of spin foam quantisation. We generalize some of our considerations to the Lorentzian setting and obtain a new spin foam model in that context as well.
2007-01-01
Transfer of chemical elements to breast milk
International Nuclear Information System (INIS)
The project is intended to yield information on the transfer factors describing the transfer of ingested radionuclides to breast milk for the following elements: antimony, cerium, chromium, cobalt, gallium, lanthanum, molybdenum, niobium, radium, ruthenium, silver, thorium, titanium, and uranium. Those yet unknown or poorly known transfer factors are required in order to be able to develop a reliable model for description and assessment of the transfer of the radionuclides and the possibly resulting hazardous doses to infants, and for subsequent formulation of recommendations for radiological protection of the population. (orig./CB)
1999-08-01
Towards a dissipativity framework for power system stabilizer design
Energy Technology Data Exchange (ETDEWEB)
This paper describes a dissipativity-based framework for the study of low-frequency oscillations in power systems and for power system stabilizer design. This framework leads to a robust controller design formulation, amenable to both H{sub {infinity}} and QFT tools. An illustrating numerical example presents QFT based design for a widely used benchmark two area, four machine power system.
1996-11-01
International Nuclear Information System (INIS)
A new formulation of the theory of tachyons is developed using the same two postulates as in special relativity. Use is made of a 'switching principle' to show how tachyons automatically obey the laws of conservation of energy, momentum and electric charge. Tachyonic mechanics is further developed by a consideration of tachyonic rods and clocks. There follows a discussion of the conservation of electric charge and the apparent visual appearance of a tachyonic cube. 19 refs., 9 figs.
The physics of tachyons. Pt. 2
International Nuclear Information System (INIS)
This paper extends the development of a new formulation of the theory of tachyons to encompass the dynamics of tachyons. Energy and momentum are discussed along with the proper mass of a tachyon. The transformation of force in extended relativity (ER) is derived. Acceleration in ER is also discussed, as well as the relationship between force and acceleration. Two simple examples relating to the motion of a charged tachyon are discussed, followed by a brief explanation of why tachyons cannot emit Cerenkov radiation in a vacuum. 13 refs., 3 figs.
In this study, six groups of rats were fed as follows: Groups 1 and 2 were fed formulated diets supplemented with zinc or without zinc respectively. Groups 3 and 4 were fed formulated diets supplemented with zinc plus phytic acid extracted from sweet potato (Ipomea batatas) or commercial phytic acid respectively. Groups 5 and 6 were fed formulated diets supplemented with phytic acid extract from sweet potato or commercial phytic acid respectively. The animals were fed for three weeks and then sacrificed The activities of key enzymes of carbohydrate and lipid metabolism as well as transaminases in the liver were determined. Blood glucose level was also assessed. Phytic acid extract consumption from sweet potato and commercial phytic acid plus zinc supplement lowered blood glucose levels. There was no significant change in the activity of 6-phosphogluconate dehydrogenase among the groups. Similarly, phytic acid ...
2005-03-01
Energy Technology Data Exchange (ETDEWEB)
The objectives of this project are to detect and characterize fractures in a naturally fractured tight gas reservoir, using surface seismic methods, borehole imaging logs, and in-situ stress field data. Further, the project aims to evaluate the various seismic methods as to their effectiveness in characterizing the fractures, and to formulate the optimum employment of the seismic methods as regards fracture characterization.
1995-04-01
Tachyons and the radiation of an accelerated charge
Energy Technology Data Exchange (ETDEWEB)
The motion of an accelerated charge in a vacuum is analyzed, via the superposition principle and Fourier analysis, into uniform-motion components, which include bradyonic as well as tachyonic contributions. It is shown that the former contribute only to the induction fields whereas the latter are the source of the radiation emitted by the charge, via the Sommerfeld-Cerenkov mechanism. This result calls for a reexamination of some recently formulated theories of superluminal particles.
1982-10-15
International Nuclear Information System (INIS)
The model of transient enhanced diffusion of ion-implanted As is formulated and the finite-difference method for numerical solution of the system of equations obtained is developed. The nonuniform distribution of point defects near the interface and more accurate description of arsenic clustering are simultaneously taken into account. Simulation of As diffusion during rapid annealing gives a reasonable agreement with the experimental data. (authors)
2005-09-01
Series capacitor compensation of high voltage transmission lines
Energy Technology Data Exchange (ETDEWEB)
A new simple analytical approach is developed for optimum size of series capacitor compensation. The method gives quick and accurate results. Need for formulating a big quadratic or voluminous fourth order equation and the solution of the above with the aid of computers is avoided. Graphical plotting also is not required. 8 refs.
1981-12-01
Radiation protection in connection with the decommissioning of nuclear plants
Energy Technology Data Exchange (ETDEWEB)
This document presents the SSI preliminary views and position concerning the decommissioning of nuclear plants. To prevent the exposure of the decommissioning personnel and the general public to unacceptable levels of radiation and to protect the environment and future generations, it is SSI`s task to formulate and issue the necessary terms and regulations with which the reactor licensees must comply during the decommissioning work. The views and principles presented here are the basis of SSI`s continued work on guidelines and regulations for the decommissioning of nuclear plants.
1997-04-01
On stochastic approximation algorithms for classes of PAC learning problems
Energy Technology Data Exchange (ETDEWEB)
The classical stochastic approximation methods are shown to yield algorithms to solve several formulations of the PAC learning problem defined on the domain [o,1]{sup d}. Under some assumptions on different ability of the probability measure functions, simple algorithms to solve some PAC learning problems are proposed based on networks of non-polynomial units (e.g. artificial neural networks). Conditions on the sizes of these samples required to ensure the error bounds are derived using martingale inequalities.
1994-03-01
Numerical analysis of the fusion of nuclear combustible rods under LOCA - type accidents
International Nuclear Information System (INIS)
The study of the melting of combustible rods is of great importance for the safety analysis of nuclear reactors. Due to the special characteristics of the problem, a sharp interface between the solid and liquid region does not exist, but appears a 'mushy' region in which the material is partially melted. The Finite Element Method is employed here, together with a regularized enthalpy formulation. Finally, the results obtained are presented and discussed. (Author).
1983-12-13
Multi-mode wavepath depth imaging for the SEG/EAGE salt model
Energy Technology Data Exchange (ETDEWEB)
Elastic depth imaging of both P-wave and S-wave prestack seismic reflection data is formulated as a degraded form of Kirchhoff migration known as Wavepath Migration (WM). Applications to the SEG/EAGE salt model show that the method is sufficiently versatile anti relaitively inexpensive. It handles S-wave data with at least the same accuracy as Pwave data when local mode conversions are removed. WM also provides an understanding of multi-mode illumination.
2003-01-01
UK PubMed Central (United Kingdom)
BackgroundIn an effort to promote healthy ageing and preserve health and function, the government of Chile has formulated a package of actions into the Programme for Complementary...Full Text Available
Merit of detailed classification of Upper Devonian deposits by self-teaching algorithmic systems
Energy Technology Data Exchange (ETDEWEB)
The formulation of the problem of classification of lithologically heterogeneous rocks and rocks with mixed capacity space is analyzed under conditions of self-teaching. Using the example of one of the boreholes of the Pripyat trough we illustrated the possibilities of the Kompakt algorithm to classify deposits of the Frasnian stage without using standard data. Problems are listed for further study on the development of methods of application of self-teaching classification systems in the petroleum industry.
1981-01-01
UK PubMed Central (United Kingdom)
N-Hydroxy-N′-(4-n-butyl-2-methylphenyl)formamidine (HET0016) is a potent inhibitor of 20-hydroxyeicosatetraenoic acid (20-HETE) formation by specific cytochrome P450 (CYP) isoforms....Full Text Available
2008-11-01
Heat transfer augmentation in rod bundles near grid spacers
International Nuclear Information System (INIS)
Heat transfer augmentation by straight grid spacers in rod bundles is studied for single phase flow and for post critical heat flux dispersed flow. The heat transfer effect of swirling grid spacers in single phase flow is also examined. Governing heat transfer mechanisms are analyzed, and predictive formulations are established. For single phase flow, the local heat transfer at a straight spacer and at its upstream or downstream locations are treated separately. 18 refs.
1980-01-01
... Operational aspects of fiscal policy making in oil-producing countries , in J. Davis, R. Ossowski and A. Fedelino (...), Fiscal Policy Formulation and Implementation in Oil-Producing Countries , International Monetary Fund, Washington, D.C. Barro, R. (...
Firefly Algorithm, Levy Flights and Global Optimization
Nature-inspired algorithms such as Particle Swarm Optimization and Firefly Algorithm are among the most powerful algorithms for optimization. In this paper, we intend to formulate a new metaheuristic algorithm by combining Levy flights with the search strategy via the Firefly Algorithm. Numerical studies and results suggest that the proposed Levy-flight firefly algorithm is superior to existing metaheuristic algorithms. Finally implications for further research and wider applications will be discussed.
2010-01-01
Evaluation of the SYNTHOIL process. Volume II. Status of development. [47 refs
The Synthoil process for producing heavy desulfurized fuel oil from coal has been under development at Pittsburgh Energy Research Center since 1969. The status of development and technical feasibility of the process are reviewed. This is part of an engineering and economic evaluation based on the conceptual design of a 100,000-bbl/day commercial Synthoil facility. Experimental data are discussed with regard to their adequacy for the formulation of a basis for the process design of such a facility. Potential engineering and equipment problems are analyzed.
1977-06-01
Energy in Lebanon: holding the stakes to get best choices
International Nuclear Information System (INIS)
An overall review of status of energy in Lebanon is presented. Energy consumption and demand, in all sectors of economy, including renewable energy sources (biomass, solar energy, kerosene, gas oils...) are described, enhanced by figures and tables. Recommendations of energy development in Lebanon within national economic policy are formulated. 4 tabs.
Electron impact excitation of lithium-like iron
Energy Technology Data Exchange (ETDEWEB)
Calculations of total and angle-differential excitation cross sections for the electron impact excitation of lithium-like iron were performed with the R-matrix formulation. The alignments of the excited states 1s{sup 2}np {sup 2}P{sub 3/2} are also presented for n=3 and 4 along with the angular photon distribution from these states to the ground state. Relativistic effects were included in the present calculations by the Breit-Pauli Hamiltonian.
1996-05-01
This document presents the findings of a study of the Ink Manufacturing Industry for the purpose of developing effluent limitations and standards, and pretreatment standards for existing and new sources to implement Sections 301, 304, 306, 307 and 501 of ...
1979-01-01
Decay scheme data for [sup 101]Mo and [sup 101]Tc
Energy Technology Data Exchange (ETDEWEB)
New measurements of relative gamma-ray emission probabilities in the decay of [sup 101]Mo and [sup 101]Tc are reported. Previously published conversion-electron data have been used along with the gamma-ray data to formulate self-consistent decay schemes. (orig.)
1993-10-01
Decay scheme data for "1"0"1Mo and "1"0"1Tc
International Nuclear Information System (INIS)
New measurements of relative gamma-ray emission probabilities in the decay of "1"0"1Mo and "1"0"1Tc are reported. Previously published conversion-electron data have been used along with the gamma-ray data to formulate self-consistent decay schemes. (orig.).
Cuckoo Search via Levy Flights
In this paper, we intend to formulate a new metaheuristic algorithm, called Cuckoo Search (CS), for solving optimization problems. This algorithm is based on the obligate brood parasitic behaviour of some cuckoo species in combination with the Levy flight behaviour of some birds and fruit flies. We validate the proposed algorithm against test functions and then compare its performance with those of genetic algorithms and particle swarm optimization. Finally, we discuss the implication of the results and suggestion for further research.
2010-01-01
Bosonization of conformal ghosts in Witten's string theory
International Nuclear Information System (INIS)
It is formulated Witten's proposal of a covariant open-string theory in terms of oscillator modes and shown that some basic axioms for the noncommutative geometry are obeyed as algebraic operations, which were defined previously from a geometrical point of view. Our strategy is based on the proper bosonization of the conformal ghost fields.
Algebraic description of perturbation theory in quantum electrodynamics
Energy Technology Data Exchange (ETDEWEB)
An algebraic formulation of the electromagnetic field in which various quantization procedures can be described was chosen to discuss perturbation calculations. It is shown that the Feynman rules and the second order calculation of the self-energy of the electron can be developed on the basis of the Fermi method of quantization. The algebraic approach clarifies the problems in defining the vacuum and other states which are associated with calculations in terms of field algebra operators. It is demonstrated that the vacuum state defined on the field algebra by Schwinger leads to incorrect results in the self-energy calculation.
1982-01-01
Ab initio calculations in a uniform magnetic field using periodic supercells
Energy Technology Data Exchange (ETDEWEB)
We present a formulation of ab initio electronic structure calculations in a finite magnetic field, which retains the simplicity and efficiency of techniques widely used in first principles molecular dynamics simulations, based on plane-wave basis sets and Fourier transforms. In addition we discuss results obtained with this method for the energy spectrum of interacting electrons in quantum wells, and for the electronic properties of dense fluid deuterium in a uniform magnetic field.
2003-10-21
A_2 Toda theory in reduced WZNW framework and the representations of the W-algebra
International Nuclear Information System (INIS)
Using the reduced WZNW formulation we analyse the classical W-orbit content of the space of classical solutions of the A_2 Toda theory. We define the quantized Toda field as a periodic primary field of the W-algebra satisfying the quantized equations of motion. We show that this local operator can be constructed consistently only in Hilbert space consisting of the representation corresponding to the minimal models of the W-algebra. (orig.).
1992-10-01
A quantum-statistical-mechanical extension of Gaussian mixture model
Energy Technology Data Exchange (ETDEWEB)
We propose an extension of Gaussian mixture models in the statistical-mechanical point of view. The conventional Gaussian mixture models are formulated to divide all points in given data to some kinds of classes. We introduce some quantum states constructed by superposing conventional classes in linear combinations. Our extension can provide a new algorithm in classifications of data by means of linear response formulas in the statistical mechanics.
2008-01-15
International Nuclear Information System (INIS)
Electron microscopic observations of neutron irradiated Nb_3Sn revealed the presence of highly disordered regions of size approximately 35 A in a much less disordered matrix. This observation is shown to provide a means of explaining quantitatively many superconducting properties of irradiated A-15 compounds. In particular Tsub(c) of the irradiated materials could be easily predicted using the mathematical formulations developed for the proximity effect. (Auth.).
Water Repellency Microstructure Oligomer Formulation Cured with Electron Beam
International Nuclear Information System (INIS)
Water repellency en the microstructure super-hydrophobic cured surface is important for research and industrial purposes. This microstructure film can be cured on polyethylene terephthalate PET surface by electron beam (EB) at different irradiation doses 10-100 kGy. The microstructure formulation composed from hydrophobic acrylate oligomer (EB 244) and monomer (SR 440). The irradiation induced cross linking of the prepared microstructure was proved by FTIR spectroscopy and the adhesion force by abrasion test. Some factors affecting the adhesion force of the prepared microstructure film such as oligomer/monomer composition ratio and the thickness of the microstructure cured film were studied. The contact angles (8) were measured on cured surfaces before and after adding the super hydrophobic nanoparticles (Zonyl 9361). The super-hydrophobic cured surface showed the self-cleaning property. The volume of water droplet affected both the observed contact angle and its ...
U.S. Department of Energy`s International Safeguards Program
Energy Technology Data Exchange (ETDEWEB)
Since 1978 the United States Department of Energy`s (DOE) International Safeguards Program has conducted policy analysis, strategies and technology development, international cooperation and training to support the formulation and implementation of international safeguards. The end of the Gulf War (1991), the end of the Cold War (1992), and the trend towards regionalization of safeguards has led to increased US and international attention to the threat of nuclear weapons proliferation and the need for significantly greater support to nonproliferation policy making and implementation activities. As a result, DOE`s International Safeguards Program has undergone substantial growth and has continued to focus its resources on the priority issues which are part of today`s and tomorrow`s world. In order to effectively and efficiently conduct and manage these activities the International Safeguards Program has developed and continues to refine and implement a strategic ...
1993-12-31
The Holst Spin Foam Model via Cubulations
Spin Foam Models (SFM) are an attempt at a covariant or path integral formulation of canonical Loop Quantum Gravity (LQG). Traditionally, SFM rely on 1. the Plebanski formulation of GR as a constrained BF Theory. 2. simplicial triangulations as a UV regulator and 3. a sum over all triangulations via group field techniques (GFT) in order to get rid off triangulation dependence. Subtle tasks for current SFM are to establish 1. the correct quantum implementation of Plebanski's constraints. 2. the existence of a semiclassical sector implementing additional Regge constraints arising from simplicial triangulations and 3. the physical inner product of LQG via GFT. We propose a new approach which deals with these issues as follows: 1. The simplicity constraints are correctly implemented by starting directly from the Holst action which is also a proper starting point for canonical LQG. 2. Cubulations are chosen rather than triangulations as a regulator. ...
2008-01-01
New methods for electronic structure calculations
Energy Technology Data Exchange (ETDEWEB)
This thesis consists of five chapters, each of which is a self-contained unit. The first chapter overviews methods for electronic-structure calculations. Chapter 2 introduces a new method to generate a rapidly converging configuration expansion. The approach iteratively combines (1) a least-squares fitting of a configuration expansion to a many-body wave function with (2) a transfer-matrix method for projecting out the ground state. Results are shown to be equivalent to multiconfiguration Hartree-Fock. Results from test calculations are given for a simple finite difference model of the helium atom. In Chapter 3 the use of the finite-element method in electronic structure calculations is discussed. Chapters 4 and 5 discuss developments in Monte Carlo methods based on Hubbard-Stratonovich transformations. Chapter 4 introduces a canonical ensemble formulation of the method, which is more appropriate than the usual grand canonical formulation for ...
1988-01-01
Neural net formulations for organically modified, hydrophobic silica aerogel
Energy Technology Data Exchange (ETDEWEB)
Organic modification of aerogel chemical formulations is known to transfer desirable hydrophobicity to lightweight solids. However, the effects of chemical modification on other material constants such as elasticity, compliance, and sound dampening present a difficult optimization problem. Here a statistical treatment of a 9-variable optimization is accomplished with multiple regression and an artificial neural network (ANN). The ANN shows 95 percent prediction success for the entire data set of elasticity, compared to a multidimensional linear regression which shows a maximum correlation coefficient, R=0.782. In this case, using the Number of Categories Criterion for the standard multiple regression, traditional statistical methods can distinguish fewer than 1.83 categories (high and low elasticity) and cannot group or cluster the data to give more refined partitions. A non-linear surface requires at least 3 categories (high, low, and medium elasticities) to ...
1997-07-01
Energy Technology Data Exchange (ETDEWEB)
Antitumor platinum(II) complexes derived from N-alkyl-propanediamine differing in the length of their carbon chain (C8, C10, C12 and C14) were incorporated in liposomes and the cytotoxic activity of these formulations was evaluated against tumor (A{sub 549}, MDA-MB-231, B16-F1 and B16-F10) and non-tumor (BHK-21 and CHO) cell lines. Stable and monodisperse liposome suspensions incorporating the platinum complexes were obtained from the lipid composition consisting of distearoyl-sn-glycero-3-phosphocholine, cholesterol and 1,2-distearoyl-sn-glycero- 3-phosphoethanolamine-N-(methoxy(polyethylene glycol)-2000) at 5:3:0.3 molar ratio. The entrapment efficiency (EE%) of the platinum complexes in liposomes increased with the carbon chain length. EE% was higher than 80% in C12- and C14-derivatives. The effect of liposome encapsulation on the cytotoxic activity of the complexes was found to depend on the carbon chain length. These data indicate that the highest drug ...
2010-07-01
Joint Receiver and Transmitter Optimization for Energy-Efficient CDMA Communications
This paper focuses on the cross-layer issue of joint multiuser detection and resource allocation for energy efficiency in wireless CDMA networks. In particular, assuming that a linear multiuser detector is adopted in the uplink receiver, the case considered is that in which each terminal is allowed to vary its transmit power, spreading code, and uplink receiver in order to maximize its own utility, which is defined as the ratio of data throughput to transmit power. Resorting to a game-theoretic formulation, a non-cooperative game for utility maximization is formulated, and it is proved that a unique Nash equilibrium exists, which, under certain conditions, is also Pareto-optimal. Theoretical results concerning the relationship between the problems of SINR maximization and MSE minimization are given, and, resorting to the tools of large system analysis, a new distributed power control algorithm is implemented, based on very little prior ...
2007-01-01
GENERIC ENZYME TECHNOLOGY FOR IMPROVED PAPER RECYCLING
Environmental Research Database
Objectives- Investigate the potential for the use of enzymes to bring about improvements in the recycling of recovered waste paper sources~%~~%~- Optimise enzyme formulations and process conditions to maximise benefits. - Produce recovered fibre at lower energy and chemical costs than is currently achievable using 'classical' de-inking techniques.~%~~%~- Improve recycled fibre quality and~%~~%~- All of the above will allow a greater use of recovered paper resources, which would otherwise be diposed of by [continued...]DescriptionThe project proposes to carry out an initial literature review to update the consortium on the currently available publications relating to the use of enzymes in de-inking.. This will be followed by an intensive laboratory study in an upgraded facility which will allow enzyme formulations and mechanisms to be studied. This work will also eliminate the need for an ...
2003-01-05
Fuzzy reliability analysis of structures by using the method of fuzzy optimization
Energy Technology Data Exchange (ETDEWEB)
There are two kinds of uncertainties in safety assessment of engineering structures. One is of the nature of randomness, and the other fuzziness. Fuzzy uncertainties exist in defining certain structural performances, conditions, parameters, and their interrelationships. The theory of fuzzy sets should be employed to cope with the fuzzy uncertainties. In this paper, a general definition for structural failure considering the fuzzy uncertainties is introduced firstly. Failure of the structure is modelled by a fuzzy event, and described by the membership function. The limit state surface is then replaced by a fuzzy limit state zone, in which every point represents a state belonging to the failure with a certain degree of membership. Then a fuzzy optimization problem for solving the reliability index is formulated. In classical structural reliability theory, the reliability index is defined by the minimum distance from the limit state surface to the origin of the ...
1996-12-31
Formulation and make-up of simulate dilute water, low ionic content aqueous solution
Energy Technology Data Exchange (ETDEWEB)
This procedure describes the formulation and make-up of Simulated Dilute Water (SOW), a low-ionic-content water to be used for Activity E-20-50, Long-Term Corrosion Studies. This water has an ionic content which is nominally a factor of ten higher than that of representative waters at or near Yucca Mountain. Representative waters were chosen as J-13 well water [Harrar, 1990] and perched water at Yucca Mountain [Glassley, 1996]. J-13 well water is obtained from ground water that is in contact with the Topopah Spring tuff, which is the repository horizon rock. The perched water is located in the Topopah Spring tuff, but below the repository horizon and above the water table. A nominal times ten higher ionic content was chosen to simulate the effect of ionic concentrating due to elevated temperature water flowing through fractures where salts and minerals have been deposited due to evaporation and boiling.
1997-04-04
Energy Technology Data Exchange (ETDEWEB)
This paper describes the test results on high-temperature strength properties of fire resistant steel(FR steel) for building, the formulation, and the examples of application to member tests and actual buildings. Because of its components and manufacturing method, FR steel excels in strength at elevated temperature due to precipitation and dispersion strengthening. Tests on high temperature properties of FR steel showed that every property such as strength, stress-strain curve, elastic modulus, and creep performance at high temperature was superior to those of conventional steels. Then, it was confirmed in the tensile tests at room temperature and high temperature after heat history that FR steel could be reused after fire. It was also found in the member tests that columns and beams of FR steel could support loadings equivalent to long-term allowable unit stress until the temperature rose up to 600 centigrade. Moreover, test results could be simulated by the ...
1991-09-30
Effect of powder characteristics on oral tablet disintegration.
This report describes an investigation of the factors affecting disintegration time in the mouth (DTM) of rapidly disintegrating tablets. The relation between DTM and stationary time of upper punch displacement (STP) was examined using a tableting process analyzer (TabAll). Results indicated that the bulk density of mixed excipient powder used for tablet preparation affects both DTM and STP. As the value of bulk density increased, STP became longer and DTM shorter. The results of a combination of granules and powder with or without a drug showed liner relation between apparent volume (reciprocal of bulk density) and DTM (r(2)=0.7332). For a DTM less than 60 s, a formulation with a bulk density greater 0.5 g/mL should be chosen with a compression force of 5 kN. The hardness of tablets could be greater than 3 kg if at least one high-compressibility excipient was used in the formulation. PMID:18804156
2008-08-29
Two enantioselective, potentiometric membrane electrodes (EPMEs) based on maltodextrins with different value of dextrose equivalent (DE) (maltodextrin I: DE 4.0-7.0; maltodextrin II: DE 16.5-19.5) were proposed for the assay of baclofen enantiomers in baclofen raw materials and from its pharmaceutical formulation, Norton-Baclofen tablets. The slopes of the electrode function of the proposed electrodes were 55.0 mV/pS-baclofen for maltodextrin I-based electrode and 59.0 mV/pR-baclofen for maltodextrin II-based electrode and the detection limits were 1.34 x 10(-6) mol l(-1) (S-baclofen) and 2.52 x 10(-10) mol l(-1) (R-baclofen), respectively. The surfaces of the electrodes are stable and easily renewable by simply polishing on alumina paper. PMID:15598435
2004-12-01
DEVELOPMENT OF SHALLOW VISCOUS OIL RESERVES IN NORTH SLOPE
Energy Technology Data Exchange (ETDEWEB)
North Slope of Alaska has huge oil deposits in heavy oil reservoirs such as Ugnu, West Sak and Shrader Bluff etc. The viscosity of the last two reservoir oils vary from {approx}30 cp to {approx}3000 cp and the amount in the range of 10-20 billion barrels. High oil viscosity and low formation strength impose problems to high recovery and well productivity. Water-alternate-gas injection processes can be effective for the lower viscosity end of these deposits in West Sak and Shrader Bluff. Several gas streams are available in the North Slope containing NGL and CO{sub 2} (a greenhouse gas). The goal of this research is to develop tools to find optimum solvent, injection schedule and well-architecture for a WAG process in North Slope shallow sand viscous oil reservoirs. In the last quarter, we have developed streamline generation and convection subroutines for miscible gas injection. The WAG injection algorithms are being developed. We formulated a four-phase relative ...
2003-07-01
Weyl gauge, Schwinger terms and bosonization in light-front field theory
Energy Technology Data Exchange (ETDEWEB)
A systematic study of non-perturbative quantum structure of the massive light-front Schwinger model and QED(3+1) in the continuum formulation is outlined. The light-front Hamiltonian and field algebra are derived in the Weyl gauge using the Dirac-Bergmann constrained quantization. Unitary transformation to the light-cone gauge representation is performed and the gauge-invariant fermi field is constructed. The importance of the Schwinger term in the current-current commutation relations for the derivation of the fermionic vacuum structure and bosonization in two dimensions is indicated.
2002-04-01
International Nuclear Information System (INIS)
The tool materials durability problem, in particular shock and wear resistance, has allowed to formulate a set of requirements and also to stablish the dependence between physical properties and wear. However, for understanding the nature of the process, for example determining the tribological property of the cutting tool, it is necessary to consider the atom interactions in a crystal. A theoretical study of the physical properties of cutting tool materials (W-Ti-C) with varying concentration of titanium is presented. Total and partial local electronic density for each atom in such hard solutions were calculated. (nevyjel)
2001-05-01
Unified description of bradyons and tachyons based on the dynamical SO(4,2) symmetry
International Nuclear Information System (INIS)
Firstly the so called 'conformal relativity' in the 6-dimensional conformal space is formulated. In particular the concept of dilatational degree of freedom - scale - is introduced. The special conformal transformations are interpreted as the transformations connecting dilatationally moving frames (and objects). The ideas, similar to those by Kaluza and Klein, can be applied to the conformal space to obtain a unification of gravitation and electromagnetism. Lastly the conformal symmetry is extended to imaginary scales and to negative scales. Particles having imaginary scales are shown to be tachyons, whilst particles with negative scales correspond to antiparticles. (Auth.).
Triangle identity and free differential algebra of massless higher spins
International Nuclear Information System (INIS)
In terms of Berezins's theory of symbols of operators, the integral formulation is suggested for the free differential algebra which gives rise to consistent equations of motion of interacting massless fields of all spins 0#<=#s<#infinity# in the frameworks of gravity. In the first nontrivial order of the expansion in powers of curvatures, Frobenius consistency conditions for higher-spin equations of motion are shown to reduce to the simple geometrical fast that there are two ways for splitting any quadrangle in two triangles. To clarify our construction, we illustrate how it works in the simplest case of pure gravity. (orig.).
1989-09-01
International Nuclear Information System (INIS)
The formalism of statistical mechanics of particles slower than light has been considered from the point of view of the application of this formalism for the description of tachyons. Properties of ideal gases of tachyons have been discussed in detail. After finding general formulae for quantum, Bose and Fermi gases the classical limit has been considered. It has been shown that Bose-Einstein condensation occurs. The tachyon gas of bosons violates the third principle of thermodynamics. Degenerated Fermi gas has been considered and in this case the entropy vanishes at zero temperature. Difficulties of formulating covariant statistical mechanics have been discussed.
The entropic boundary law in BF theory
International Nuclear Information System (INIS)
We compute the entropy of a closed bounded region of space for pure 3d Riemannian gravity formulated as a topological BF theory for the gauge group SU(2) and show its holographic behavior. More precisely, we consider a fixed graph embedded in space and study the flat connection spin network state without and with particle-like topological defects. We regularize and compute exactly the entanglement for a bipartite splitting of the graph and show it scales at leading order with the number of vertices on the boundary (or equivalently with the number of loops crossing the boundary). More generally these results apply to BF theory with any compact gauge group in any space-time dimension.
2009-01-11
Divergence between aircraft engine emission regulations proposed by EPA and ICAO is discussed. Every engine, upon entering service, requires a certificate as to its compliance with emission standards. It is shown that despite the large variability in the measurements, it is possible to devise a certification procedure requiring the testing of one engine only. Statistical modeling of such a test at the 5% significance level is described. Values of the parameter standard deviation/mean recommended as certification standards for various pollutants are given. Features of a rational certification scheme to be formulated are outlined.
1978-10-01
A novel drug delivery system for the treatment of brain tumors was formulated by methotrexate (MTX)-loaded polymeric nanoparticles (NPs) based on Glycol chitosan (GCS) and Dextran sulfate (DS). The physicochemical properties of resulting particles were investigated, evidencing the contribution of these nanoparticles for brain targeting. In vitro release of MTX was also evaluated. The GCS-DS nanoparticles have been developed based on the modulation of ratio show promise as a system for controlled delivery of the drug to the brain. PMID:21782844
2011-07-19
Synthesis and Biophysical Characterization of Chlorambucil Anticancer Ether Lipid Prodrugs
DEFF Research Database (Denmark)
The synthesis and biophysical characterization of four prodrug ether phospholipid conjugates are described. The lipids are prepared from the anticancer drug chlorambucil and have C16 and C18 ether chains with phosphatidylcholine or phosphatidylglycerol headgroups. All four prodrugs have the ability to form unilamellar liposomes (86-125 nm) and are hydrolyzed by phospholipase A2, resulting in chlorambucil release. Liposomal formulations of prodrug lipids displayed cytotoxicity toward HT-29, MT-3, and ES-2 cancer cell lines in the presence of phospholipase A2, with IC50 values in the 8-36 ?M range.
2009-01-01
Surfactant flooding - an overview of recent French results
Energy Technology Data Exchange (ETDEWEB)
Enhanced recovery by chemical flooding using surfactant and/or polymers simultaneously implies the following: (1) a fundamental knowledge of the physical chemistry of micellar systems and interfaces; (2) the proper formulation of mathematic models handling the basic mechanisms of oil recovery; and (3) the use of field-scale pilot units to test the validity of the models and to acquire technical knowledge. Efforts have been made by the French in these directions, and the main results are described. Special attention is paid to the search for new products and the improvement of manufacturing processes. 10 references.
1983-01-01
Structural bonding-breakage constitutive model for natural unsaturated clayey soils
British Library Electronic Table of Contents (United Kingdom)
The natural clayey soils are usually structural and unsaturated, which makes their mechanical properties quite different from the remolded saturated soils. A structural constitutive model is proposed to simulate the bonding-breakage micro-mechanism. In this model, the unsaturated soil element is divided into a cementation element and a friction element according to the binary medium theory, and the stress-strain coordination for these two elements is obtained. The cementation element is regarded as elastic, whereas the friction element is regarded as elastoplastic which can be described with the Gallipoli?s model. The theoretical formulation is verified with the comparative experiments of isotropic compressions on the saturated and unsaturated structural soils. Parametric analyses of the e...
2010-01-01
The results of a study conducted by Working Group 10 of the AGARD Fluid Dynamics Panel to investigate the limits of boundary layer methods, both the integral and field type formulations, for calculating three-dimensional turbulent separated flow are presented. Test cases used to assess the boundary layer calculations included the DFLVR prolate spheroid at angle of attack and the NASA-Ames Wing C. Comparisons between boundary layer calculations and experimental data are presented for these test cases along with observations, conclusions, and recommendations.
1990-05-01
Energy Technology Data Exchange (ETDEWEB)
One of the essential steps in the main scope Project Management is the Time Management made by the planning and control of the project schedule. In this work is presented the resource constrained scheduling problem beyond its mathematical formulation and a review of papers about this issue. In sequence is presented a practical example of this model considering a simplified model of an engineering project schedule of oil production equipment. The results obtained with the model application are shown and the conclusions about the work with resource constrained scheduling problems. (author)
2008-07-01
Problems involved in developing an index of harm
International Nuclear Information System (INIS)
Death as a criterion (age distribution of occupational death; mean loss of life years due to radiation deaths); accidents at work (incidence of accidents of certain degrees of severity); total loss of working days due to accidents; occupational diseases; somatic and genetic radiation effects; radiation effects during pregnancy (incidence of pregnancies, ristes before implantation, hazards to the embryo, hazards to the foetus, total additional risk due to radiation exposure during pregnancy); age and sex dependence of risk figures; attempted formulation of an index of harm. (HP/orig.).
1979-01-01
Privatization of the ESI. Broadening the debate. [Electricity supply industry in the UK
Energy Technology Data Exchange (ETDEWEB)
The debate over the privatization of electricity in the UK has been conducted across too narrow a terrain, being primarily concerned with regulation for optimality in the context of static, if uncertain, conditions of supply and demand. Insufficient account has been taken of dynamic agencies in formulating and bringing about progressive industrial change, something of great importance in the light of their weakness in the UK context. Consequently, a number of deficiencies in the UK ESI have been neglected in the debate over privatization and are not liable to be rectified by it in practice. (author).
1989-06-01
Energy Technology Data Exchange (ETDEWEB)
Preliminary results of studies into penetrant testing at high surface temperature (up to 200 deg.C), are presented. Tests were performed to assess the effectiveness of red dye penetrants using Al and NiCr samples containing artificial as well as natural discontinuities. The test results will be used in due course to formulate a specification for non-destructive testing procedure qualification at non-standard (i.e. outside 16-52 deg.C) temperatures.
2000-04-01
Particle emission in hydrodynamics: a problem needing a solution
A survey of various mechanisms for particle emission in hydrodynamics is presented. First, in the case of sudden freeze out, the problem of negative contributions in the Cooper-Frye formula and ways out are presented. Then the separate chemical and thermal freeze out scenario is described and the necessity of its inclusion in a hydrodynamical code is discussed. Finally, we show how to formulate continuous particle emission in hydrodynamics and discuss extensively its consistency with data. We point out in various cases that the interpretation of data is quite influenced by the choice of the particle emission mechanism.
2004-01-01
Organometallic Polymer Coatings for Geothermal-Fluid-Sprayed Air-Cooled Condensers: Preprint
Energy Technology Data Exchange (ETDEWEB)
Researchers are developing polymer-based coating systems to reduce scaling and corrosion of air-cooled condensers that use a geothermal fluid spray for heat transfer augmentation. These coating systems act as barriers to corrosion to protect aluminum fins and steel tubing; they are formulated to resist the strong attachment of scale. Field tests have been done to determine the corrosion and scaling issues related to brine spraying and a promising organometallic polymer has been evaluated in salt spray tests.
2002-08-01
Energy Technology Data Exchange (ETDEWEB)
This paper presents a new algorithm for the optimal long-range generation planning for a thermal system with pumped-storage plants. The algorithm is based upon the analytical production costing model developed under the assumption of Gaussian probabilistic distribution of random load fluctuations and plant outages. The optimization problem consists of the master problem to determine the annual investment, and the pumped-storage subproblem to determine the optimal pumped-storage operation. The master problem is formulated as a Hamiltonian minimization problem, and the pumped-storage subproblem is solved using the concept of peak-shaving operation on the original load curve.
1986-01-01
Energy Technology Data Exchange (ETDEWEB)
This paper presents a new algorithm for the optimal long-range generation planning for a thermal system with pumped-storage plants. The algorithm is based upon the analytical production costing model developed under the assumption of Gaussian probabilistic distribution of random load fluctuations and plant outages. The optimization problem consists of the master problem to determine the annual investment, and the pumped-storage subproblem to determine the optimal pumped-storage operation. The master problem is formulated as a Hamiltonian minimization problem, and the pumped-storage subproblem is solved using the concept of peak-shaving operation on the original load curve.
1987-05-01
British Library Electronic Table of Contents (United Kingdom)
In this article we obtain an alternative formulation of the von Mises type conditions for p-max stable laws in terms of generalized log Pareto distributions (glogPds). Relationship between the rate of convergence of extremes and the remainder terms in the von Mises type conditions is investigated. It is shown that the rate of convergence in the von Mises type conditions for p-max stable laws determines the distance of the underlying distribution function from a glogPd.
2011-01-01
Off-shell amplitudes for open bosonic strings
Energy Technology Data Exchange (ETDEWEB)
An extension of the Polyakov path-integral formulation to compute off-shell amplitudes for open bosonic strings is derived. Boundary conditions require evaluating the path integral on open surfaces with corners on the boundaries. The contribution to the topological term in the action from the corners is exactly that required for unitarity. The presence of corners introduces a Weyl anomaly in the Polyakov measure. This requires a gauge-fixing procedure for the off-shell amplitudes. Consistent factorization of amplitudes with one or two off-shell strings and any number of on-shell tachyons is established.
1988-02-15
Numerical integration of the Feynman Path Integral for radiative transport
International Nuclear Information System (INIS)
The radiative transport problem is cast in integral form using a transport kernel. The transport kernel has an explicit representation in terms of a Feynman Path Integral over all paths between selected points in a volume. This representation is setup in detail. Numerical evaluation of this Path Integral is formulated with a Frenet-Serret based procedure for generating valid random paths, and with a numerical evaluation of the weight for each valid path. Very early sanity checks of a numerical implementation are reported. Approaches to optimization are identified. (authors)
2009-05-03
Acute agitation is a frequent reason for emergency psychiatric intervention. It is important to intervene early to avoid escalation of agitation to aggression. Reducing risk by using effective treatments will result in fewer instances of seclusion and restraint, and fewer injuries to staff and patients. This paper will first review the epidemiology of aggressive behavior and mental disorders, followed by a discussion of assessment and diagnostic considerations. The pathophysiology of safety risk is discussed within the context of the model of the "triune brain." Pharmacological treatment strategies for acute episodes of agitated behavior will be discussed in detail. This includes newer formulations of novel antipsychotics such as liquids and rapidly disintegrating tablets, as well as intramuscular preparations. PMID:15335224
2004-01-01
Melter system technology testing for Hanford Site low-level tankwaste vitrification
Energy Technology Data Exchange (ETDEWEB)
Following revisions to the Tri-Party Agreement for Hanford Site cleanup, which specified vitrification for Complete melter feasibility and system operability immobilization of the low-level waste (LLW) tests, select reference melter(s), and establish reference derived from retrieval and pretreatment of the radioactive LLW glass formulation that meets complete systems defense wastes stored in 177 underground tanks, commercial requirements (June 1996). Available melter technologies were tested during 1994 to 1995 as part of a multiphase program to select reference Submit conceptual design and initiate definitive design technologies for the new LLW vitrification mission.
1996-05-03
... A better understanding of the links between nutrients, the gut microbiome and the intestinal immune system is likely to pave the way to the development of innovative approaches that target activation of specific immunological pathways for promoting the hostrsquo;s gut defense. Such knowledge should positively impact on the development of vaccine formulations and intervention strategies for improved control of enteric infections in developing countries. Registration fees # The Registration Fee is $715.00 on and before September 7, 2011. # After September 7, 2011, the ...
Making resource recovery economical
Energy Technology Data Exchange (ETDEWEB)
Four major reasons why municipal resource recovery operations are uneconomical are analyzed. These reasons are: alternative municipal waste disposal methods are artificially underpriced when the costs of meeting modern environmental standards are considered; high capital costs related to the procurement of resource recovery systems and the marketing of recovered resources; uncertainties associated with the costs and performance of resource recovery technologies; and construction and operating risks of municipal waste resource recovery systems. If resource recovery is to become economical, purchasers of plants must develop innovative process designs and equipment and formulate new operating and maintenance procedures. (1 photo)
1980-01-01
Kinetics of salt concentration in heated crevices
International Nuclear Information System (INIS)
In PWR steam-generators, the crevice between tube and tube-support plate tends to fill with porous deposits during operation and acts as a concentration site for chemicals in the boiler water, which may lead to corrosion of the tube and tube-support-plate. The rate of concentration, the magnitude of the concentration factor and the rate of release of solute when conditions change are important parameters for devising strategies to minimize corrosion. Values of these parameters for salt concentration have therefore been measured in a laboratory simulation of the crevice and are used to formulate a model of the concentrating process.
1985-03-01
Industrial processing of complex fluids: Formulation and modeling
Energy Technology Data Exchange (ETDEWEB)
The production of many important commercial materials involves the evolution of a complex fluid through a cooling phase into a hardened product. Textile fibers, high-strength fibers(KEVLAR, VECTRAN), plastics, chopped-fiber compounds, and fiber optical cable are such materials. Industry desires to replace experiments with on-line, real time models of these processes. Solutions to the problems are not just a matter of technology transfer, but require a fundamental description and simulation of the processes. Goals of the project are to develop models that can be used to optimize macroscopic properties of the solid product, to identify sources of undesirable defects, and to seek boundary-temperature and flow-and-material controls to optimize desired properties.
1997-08-01
Energy Technology Data Exchange (ETDEWEB)
The formalism of statistical mechanics of particles slower than light has been considered from the point of view of the application of this formalism for the description of tachyons. Properties of ideal gases of tachyons have been discussed in detail. After finding general formulae for quantum, Bose and Fermi gases the classical limit has been considered. It has been shown that Bose-Einstein condensation occurs. The tachyon gas of bosons violates the third principle of thermodynamics. Degenerated Fermi gas has been considered and in this case the entropy vanishes at zero temperature. Difficulties of formulating covariant statistical mechanics have been discussed.
1984-06-11
Idaho National Laboratory 2013-2022 Ten-Year Site Plan
Energy Technology Data Exchange (ETDEWEB)
The Idaho National Laboratory (INL) Ten-Year Site Plan (TYSP) describes the strategy for accomplishing the long-term objective of transforming the laboratory to meet Department of Energy (DOE) national nuclear research and development (R&D) goals, as outlined in DOE strategic plans. The plan links R&D mission goals and INL core capabilities with infrastructure requirements (single- and multi-program), establishs the 10-year end-state vision for INL complexes, and identifies and prioritizes infrastructure needs and capability gaps. The TYSP serves as the basis for documenting and justifying infrastructure investments proposed as part of the FY 2013 budget formulation process.
2011-06-01
Harmonic oscillator representation in the theory of scattering and nuclear reactions
Energy Technology Data Exchange (ETDEWEB)
The following questions, concerning the application of the harmonic oscillator representation (HOR) in the theory of scattering and reactions, are discussed: the formulation of the scattering theory in HOR; exact solutions of the free motion Schroedinger equation in HOR; separable expansion of the short range potentials and the calculation of the phase shifts; `isolated states` as generalization of the Wigner-von Neumann bound states embedded in continuum; a nuclear coupled channel problem in HOR; and the description of true three body scattering in HOR. As an illustration the soft dipole mode in the (11)Li nucleus is considered in a frame of the (9)Li+n+n cluster model taking into account three body continuum effects.
1995-01-01
From recreational mathematics to recreational programming, and back
British Library Electronic Table of Contents (United Kingdom)
Recreational Programming (RecPro) is the discipline that encourages the study of computer programming through ludic problems. Problems that are typically studied within this discipline are similar to those of Recreational Mathematics (RecMat), which sometimes leads to the confusion of these two disciplines. The objective for RecPro is to write programs, while RecMat practitioners can use these programs to state (and prove if possible) conjectures about the solution. This interaction leads to a mathematical quality production. In an educational framework, problems in elemental number theory (those that are formulated with a basic knowledge of arithmetic) are very interesting, leading to the revision of classical unsolved problems. One of these problems is the general form of Zumkeller numbe...
2011-01-01
Fractal analysis of deformation-induced dislocation patterns
Energy Technology Data Exchange (ETDEWEB)
The paper reports extensive analyses of the fractal geometry of cellular dislocation structures observed in Cu deformed in multiple-slip orientation. Several methods presented for the determination of fractal dimensions are shown to give consistent results. Criteria are formulated which allow the distinguishing of fractal from non-fractal patterns, and implications of fractal dislocation patterning for quantitative metallography are discussed in detail. For an interpretation of the findings a theoretical model is outlined according to which dislocation cell formation is associated to a noise-induced structural transition far from equilibrium. This allows relating the observed fractal dimensions to the stochastic properties of deformation by collective dislocation glide.
1999-06-22
Feynman integral treatment of the Bargmann potential
International Nuclear Information System (INIS)
A method based on path integral formulation is given for obtaining exact solution of the s states for the Bargmann potentialV(r)=1ka"2#beta#(#beta#-1)e"-"2"r"/"a1-e"-"r"/"a"2-Ae"-"r"/"a1-e"-"r"/"a,where #beta# and k are parameters. The exact energy spectrum and the normalised s-state eigenfunctions are obtained from the poles of the Green function and their residues, respectively. The results are compared with their of Schrodinger formalism, special cases are also discussed.
2005-06-01
Extended covariance under nonlinear canonical transformation in Weyl quantization
A theory of nonunitary-invertible as well as unitary canonical transformations is formulated in the context of Weyl's phase space representations. Exact solutions of the transformation kernels and the phase space propagators are given for the three fundamental canonical maps as fractional-linear, gauge and contact (point) transformations. Under the nonlinear maps a phase space representation is mapped to another phase space representation thereby extending the standard concept of covariance. This extended covariance allows Dirac-Jordan transformation theory to naturally emerge from the Hilbert space representations in the Weyl quantization.
2000-01-01
Eulerian-Lagrangian relationships in Monte Carlo simulations of turbulent diffusion
Energy Technology Data Exchange (ETDEWEB)
The results of this study show that Monte Carlo simulations of diffusion in homogeneous turbulence can be formulated in terms of the Eulerian space-time velocity autocorrelation function. Numerical results obtained using this approach agree with results obtained by Taylor (1921) using the Lagrangian autocorrelation function. Use was made of the equivalence of the Lagrangian and Eulerian Monte Carlo approaches to derive analytic relations between the Lagrangian integral time scale and the Eulerian integral space and time scales. These analytic results were verified by comparison to Monte Carlo simulations and to other theoretical results. They are in general agreement with many existing theories and semi-empirical relations.
1983-01-01
Encapsulated magnetite particles for biomedical application
International Nuclear Information System (INIS)
The process of miniemulsification allows the generation of small, homogeneous, and stable droplets containing monomer or polymer precursors and magnetite which are then transferred by polymer reactions to the final polymer latexes, keeping their particular identity without serious exchange kinetics involved. It is shown that the miniemulsion process can excellently be used for the formulation of polymer-coated magnetic nanoparticles which can further be used for biomedical applications. The use of high shear, appropriate surfactants, and the addition of a hydrophobe in order to suppress the influence of Ostwald ripening are key factors for the formation of the small and stable droplets in miniemulsion and will be discussed. Two different approaches based on miniemulsion processes for the encapsulation of magnetite into polymer particles will be presented in detail.
2003-04-23
Energy Technology Data Exchange (ETDEWEB)
Emulsion explosives were discovered by Richard S Egley in 1961, but remained little known prior to rapid commercial development in the late 1970s. Their introduction has a significance that may in future be compared with the formulation of dynamite by Nobel in 1867 and the development of ammonium nitrate explosives in the mid 1950s. For the mining engineer emulsion explosives provide advantages of being inherently waterproof and having high strength with a high and stable velocity of detonation giving good fragmentation in hard rock. This is available at moderate cost, from an explosive that typically does not contain any self explosive ingredients and with fume properties that offer considerable advantages over other explosives. 2 figs., 1 tab.
1989-01-01
International Nuclear Information System (INIS)
Polymer composites are used in numerous applications. In spite of this fact, new developments are still under way to explore in other field of application of these materials and to tailor their properties for more extreme condition. A particular emphasis is focused on fillers content is summarized. Some steps towards the functionally graded materials are illustrated. The FT-IR spectroscopic studies revealed the information about curing of epoxy with fillers. It was observed that mechanical properties like tensile strength, hardness etc get enhanced up with filler contents. The effect of the different formulations were investigated and discussed for optimum process condition. (author)
1398-01-01
Development of a solvent extraction process for cesium removal from SRS tank waste
International Nuclear Information System (INIS)
An alkaline-side solvent extraction process was developed for cesium removal from Savannah River Site (SRS) tank waste. The process was invented at Oak Ridge National Laboratory and developed and tested at Argonne National Laboratory using singlestage and multistage tests in a laboratory-scale centrifugal contactor. The dispersion number, hydraulic performance, stage efficiency, and general operability of the process flowsheet were determined. Based on these tests, further solvent development work was done. The final solvent formulation appears to be an excellent candidate for removing cesium from SRS tank waste.
2001-06-30
Design of optimal control under uncertain initial conditions: A minimax approach
British Library Electronic Table of Contents (United Kingdom)
The need for a game-theoretical formulation of the problem of linear-quadratic control under nonmeasurable plant state where the functional depends on the uncertain initial state was substantiated. The minimax output control law in terms of linear matrix inequalities that may be regarded as the optimal robust control law for the given set of the plant initial states was established assuming that the measurable components of the initial state were known and the nonmeasurable components take on values within the given ellipsoid. The results obtained were generalized to the plants with uncertain parameters.
2009-01-01
British Library Electronic Table of Contents (United Kingdom)
The cubature Kalman filter (CKF) is a relatively new addition to derivative-free approximate Bayesian filters built under the Gaussian assumption. This paper extends the CKF theory to address nonlinear smoothing problems; the resulting state estimator is named the fixed-interval cubature Kalman smoother (FI-CKS). Moreover, the FI-CKS is reformulated to propagate the square-root error covariances. Although algebraically equivalent to the FI-CKS, the square-root variant ensures reliable implementation when committed to embedded systems with fixed precision or when the inference problem itself is ill-conditioned. Finally, to validate the formulation, the square-root FI-CKS is applied to track a ballistic target on reentry.
2011-01-01
Corrosion and reliability of PWR power plants
International Nuclear Information System (INIS)
Corrosion is increasingly becoming an important factor reducing the reliability of many nuclear power plant components. The significance is evaluated of corrosion phenomena with respect to the reliability of primary circuit components of LWR's, viz., the reactor pressure vessel, primary piping, steam generator, and fuel elements. The mechanism of corrosion phenomena is explained and methods of minimizing their effects are presented. An analysis is made of the needs to solve the corrosion problems of nuclear power plants from the point of view of Czechoslovak producers and research and development activities. International cooperation is reviewed and main problems are formulated on which the solution of corrosion problems of structural materials used in WWER type nuclear power plants should be focussed. (author).
Calculation of eddy current losses in metal parts of power transformers
Energy Technology Data Exchange (ETDEWEB)
To maintain quality, performance and competitiveness, the eddy current losses in metal parts of power transformers in the range of 50-200 MVA are investigated in a more detailed form. The finite element calculations utilize different modelling strategies for the current carrying metal parts. Several global and local results are further used to obtain simplified calculation approaches for an inclusion in the initial design and the design optimization. The results from two finite element approaches using nodal and edge based formulations will be compared with measurements. (Author)
2003-04-01
CSIRO PUBLISHING - Wildlife Research
... Cameron; Lowell A. Miller; Miller, Lowell A. CSIRO PUBLISHING - Wildlife Research Books Journals Multimedia About Us Shopping Cart You are here: Journals Wildlife Research Ecology, Management and Conservation in Natural and Modified Habitats Search ... Cameron and Lowell A. Miller Abstract Context. Contraception is increasingly used as a management technique to reduce fertility in wildlife populations; however, the feasibility of contraceptive formulations has been limited until recently because they have required multiple treatments to achieve prolonged infertility. ...
CO2 CAPTURE BY ABSORPTION WITH POTASSIUM CARBONATE
Energy Technology Data Exchange (ETDEWEB)
The objective of this work is to improve the process for CO{sub 2} capture by alkanolamine absorption/stripping by developing an alternative solvent, aqueous K{sub 2}CO{sub 3} promoted by piperazine. Progress has been made in this reporting period on three subtasks. A simple thermodynamic model has been developed to represent the CO{sub 2} vapor pressure and speciation of the new solvent. A rate model has been formulated to predict the CO{sub 2} flux with these solutions under absorber conditions. A process and instrumentation diagram and process flow diagram have been prepared for modifications of the existing pilot plant system.
2002-10-01
Bianchi type IX cosmological models with homogeneous spinor fields
Energy Technology Data Exchange (ETDEWEB)
The diagonal and symmetric Bianchi type IX models are coupled to a homogeneous spinor field. An action for the combined fields is constructed, where the orthonormal basis used is given explicitly in terms of the metric. This allows one to vary the action with respect to the metric and the spinor fields only. Next, a Hamiltonian formulation is given, and a qualitative solution for the problem is presented. We also show that the k = +1 FRW (Friedmann--Robertson--Walker) model is not compatible with a homogeneous spinor field, while the more complicated models are.
1981-03-01
Bianchi type IX cosmological models with homogeneous spinor fields
International Nuclear Information System (INIS)
The diagonal and symmetric Bianchi type IX models are coupled to a homogeneous spinor field. An action for the combined fields is constructed, where the orthonormal basis used is given explicitly in terms of the metric. This allows one to vary the action with respect to the metric and the spinor fields only. Next, a Hamiltonian formulation is given, and a qualitative solution for the problem is presented. We also show that the k = +1 FRW (Friedmann--Robertson--Walker) model is not compatible with a homogeneous spinor field, while the more complicated models are.
Basis states for relativistic dynamically entangled particles
In several recent papers on entanglement in relativistic quantum systems and relativistic Bell's inequalities, relativistic Bell-type two-particle states have been constructed in analogy to nonrelativistic states. These constructions do not have the form suggested by relativistic invariance of the dynamics. Two relativistic formulations of Bell-type states are shown for massive particles, one using the standard Wigner spin basis and one using the helicity basis. The construction hinges on the use of Clebsch-Gordan coefficients of the Poincare group to reduce the direct product of two unitary irreducible representations (UIRs) into a direct sum of UIRs.
2005-02-01
Asset Prices, Liquidity, and Monetary Policy in an Exchange Economy
British Library Electronic Table of Contents (United Kingdom)
I formulate a model in which money coexists with equity shares on a risky aggregate endowment. Agents can use equity as a means of payment, so shocks to equity prices translate into aggregate liquidity shocks that disrupt the mechanism of exchange. I characterize a family of optimal monetary policies and find that the resulting equity prices are independent of monetary considerations. I also study a perturbation of the family of optimal policies that targets a positive constant nominal interest rate and find that in this case the real equity return includes a liquidity return that depends on monetary considerations.
2011-01-01
Analysis of laminar flow heat transfer in uniform temperature circular tubes with tape inserts
Constant property, laminar flow heat transfer in a semicircular tube with uniform wall temperature has been analyzed to define the lower bound of heat transfer augmentation in circular tubes with twisted-tape inserts. Two thermal boundary conditions, which correspond to the two extremes of the fin effect of twisted tapes encountered in practical applications, are considered. Numerical solutions, employing finite-difference formulations for the governing momentum and energy equations were carried out for the thermal entrance region and for fully developed flow.
1986-05-01
An improved colony PCR procedure for genetic screening of Chlorella and related microalgae.
A colony PCR technique was applied for both genomic and chloroplast DNA in the green microalgae Chlorella. Of five different lysis buffers, Chelex-100 was superior for DNA extraction, PCR and DNA storage. It also was insensitive to variations in cell density. The conditions established for an improved PCR formulation are applicable for screening of genetically-engineered transformants as well as bioprospecting of natural microalgal isolates. Besides multiple Chlorella species, we also demonstrate the efficacy of Chelex-100 for colony PCR with a number of other microalgal strains, including Chlamydomonas reinhardtii, Dunaliella salina, Nannochloropsis sp., Coccomyxa sp., and Thalassiosira pseudonana. PMID:21431847
2011-03-24
Algorithmic tangent stiffness in elastoplasticity and elastoviscoplasticity: A geometric insight
British Library Electronic Table of Contents (United Kingdom)
The algorithmic, or consistent, tangent stiffness was introduced to improve the asymptotic convergence rate of the iterative correction algorithm for the evolutive analysis of elastoplastic structures. The original approach is based on a formulation of the elastoplastic law in terms of a plastic multiplier with an analysis which, in general, requires an operator inversion. A geometric description of the method, based on hypersurface theory, is proposed here to provide a clear picture of the algorithmic properties. An estimate of the tangent stiffness associated with finite step elastoplastic and elastoviscoplastic constitutive models is given. It is based on the properties of the projection operator on the elastic domain and avoids operator inversions retaining the beneficial properties of...
2010-01-01
International Nuclear Information System (INIS)
The detection efficiency of #alpha# particles of "2"1"4Po 7.69 MeV and "2"1"8Po 6.00 MeV in measuring radon daughters were determined through the data which were measured with long-lived #alpha# standard source and radon daughter standard source and with curve-fitting method of general formulation. The indeterminacy was #<=#2.5% and #<=#2.7% respectively. Their ranges in filter membrane were also determined, and the effect of the indeterminacy on the self-absorption factors was #<=#1.3%.
Accelerated aging of EPDM and butyl elastomers
Energy Technology Data Exchange (ETDEWEB)
This study was composed of three parts: a post cure study to optimize final properties of an ethylene-propylene-diene (EPDM) formulation, an accelerated aging study to compare the stress relaxation behavior of a butyl and an EPDM elastomer under compression, and a cursory evaluation of a new 70 Shore A EPDM. The optimum postcure for the EPDM was found to be 2 to 4 hours at 182{degrees}C in a vacuum. The EPDM was also shown to have superior aging characteristics compared to the butyl and is recommended for use instead of the butyl material. The physical properties for new 70 Shore A EPDM are satisfactory, and the stress relaxation behavior was only slightly inferior to the other EPDM.
1996-06-01
A somatic dose index for diagnostic radiology
International Nuclear Information System (INIS)
Irradiation of the human body in diagnostic X-ray procedures results in different absorbed doses in the various body organs. A somatic dose index in formulated by applying the relative sensitivity of the human to each of the most important somatic effects and utilizing the absorbed dose in the affected organs. This quantity is used to convey a cumulative somatic impact and is computed for common radiographic views in diagnostic radiology as a function of beam quality for a nominal IR entrance exposure. Using typical X-ray beam qualities and exposures, the frequency of the various radiographic views that make up an examination and the frequencies of the various examinations in the national population, illustrative examples of the application of the somatic dose index are presented. (author).
1978-01-01
A navigation filter for fusing DTM/correspondence updates
An algorithm for pose and motion estimation using corresponding features in images and a digital terrain map is proposed. Using a Digital Terrain (or Digital Elevation) Map (DTM/DEM) as a global reference enables recovering the absolute position and orientation of the camera. In order to do this, the DTM is used to formulate a constraint between corresponding features in two consecutive frames. The utilization of data is shown to improve the robustness and accuracy of the inertial navigation algorithm. Extended Kalman filter was used to combine results of inertial navigation algorithm and proposed vision-based navigation algorithm. The feasibility of this algorithms is established through numerical simulations.
2011-01-01
A fast production scheduler for generation expansion planning in a hydro-thermal system
Energy Technology Data Exchange (ETDEWEB)
A fast production scheduling algorithm suitable for generation expansion studies is described in this paper. It can handle several independent rivers, thermal plants, pumped storage plants, import, export, and internal non-firm markets. Inflows and load are deterministic and a one-reservoir limit is imposed on each river. The scheduling problem is formulated as a generalized network problem which is efficiently solved by an adaption of the simplex method. The algorithm is part of a program developed by Hydro-Quebec to conduct preliminary evaluations of alternative expansion plans. The program and the scheduling algorithm are presented.
1986-01-01
A fast production scheduler for generation expansion planning in a hydro-thermal system
Energy Technology Data Exchange (ETDEWEB)
A fast production scheduling algorithm suitable for generation expansion studies is described in this paper. It can handle several independent rivers, thermal plants, pumped storage plants, import, export, and internal non-firm markets. Inflows and load are deterministic and a one-reservoir limit is imposed on each river. The scheduling problem is formulated as a generalized network problem which is efficiently solved by an adaption of the simplex method. The algorithm is part of a program developed by Hydro-Quebec to conduct preliminary evaluations of alternative expansion plans. The program and the scheduling algorithm are presented.
1987-02-01
A dose computation algorithm used in MLC conformal treatment
International Nuclear Information System (INIS)
A dose calculation algorithm for MLC based conformal radiotherapy is described in this paper. The algorithm is formulated by the coordinate of MLC leaves. Verification on the algorithm is made by comparing the dose distributions generated by this algorithm with that generated by a Differential Convolution Superposition algorithm for various regular and irregular fields. The results demonstrate that the present algorithm has suitable accuracy and high computational efficiency, thus it could be useful for the treatment planning process in MLC based conformal radiotherapy, where the workload for interactively or automatically designing the shapes of MLC is heavy. (authors)
2007-12-01
Utilization of smooth models for seismic data tomographic inversion
Energy Technology Data Exchange (ETDEWEB)
Reflection tomography allows in theory the determination of the velocity distribution and the reflector geometries in the subsurface from the travel times of the seismic waves. The solution of the inverse problem is the model (velocity distribution and reflectors) that minimizes the misfits between observed travel times and travel times computed by raytracing (the forward problem). Two representations of the velocity field are generally used: blocky models (discontinuous) and smooth models. The object of this thesis is the study of tomography with smooth models which offer interesting properties at a practical level as well as at a mathematical and numerical level. We propose an original formulation of the inverse problem which allow the integration of a priori information adapted to smooth models. This formulation assures the existence, the uniqueness and the stability of the solution of the linearized inverse problem. The non-linear inverse ...
1995-03-01
Energy Technology Data Exchange (ETDEWEB)
The objective of this project is to develop a pellet formulation which is capable of achieving low sulfur partial pressures and a high capacity for sulfur, loaded from a hot fuel gas and which is readily regenerable. Furthermore the pellet must be strong for potential use in a fluidized bed and regenerable over many cycles of loading and regeneration. Regeneration should be in air or oxygen-depleted air to produce a high-concentration sulfur dioxide. Fixed-bed tests were conducted with several formulations of manganese sesquioxide and titania, and alumina They were subject to a simplified fuel gas of the oxygen-blown Shell type spiked with a 30,000ppmv concentration of H{sub 2}S. Pellet crush strengths for 4 and 2mm diameter pellets was typically 12 lbs per pellet and 4 lbs per pellet, respectively. For the most favorable of the formulations tested and under the criteria of break-through at less than 100ppmv H2S and loading ...
1996-06-12
Graft copolymers of methyl methacrylate and biodegradable, biocompatible bacterial poly([R]-3-hydroxybutyrate) (PHB) blocks were synthesized and evaluated as possible constituents in acrylic bone cements for use in orthopaedic applications. The copolymers were produced by conventional free radical copolymerization and incorporated in one commercially available acrylic bone cement brand, Antibiotic Simplex (AKZ). Cements with formulations containing 6.7 and 13.5 wt % of PMMA-graft-PHB were prepared. The morphology of the graft copolymer particles was suggested to influence the ability of the modified cement to be processed. Formulations containing more than about 20 wt % of the graft copolymer resulted in cement doughs that, both after first preparation and several hours later, were either sandy or soft spongy in texture and, thus, would be unacceptable for use in orthopaedic applications. The morphologies of the powders and the volumetric ...
2006-04-01
International Nuclear Information System (INIS)
In this paper, a phenomenological model of the thermal hydraulics of convective boiling in the post-critical-heat-flux (post-CHF) regime is developed and discussed. The model was implemented in the TRAC-PF1/MOD2 computer code (an advanced best-estimate computer program written for the analysis of pressurized water reactor systems). The model was built around the determination of flow regimes downstream of the quench front. The regimes were determined from the flow-regime map suggested by Ishii and his coworkers. Heat transfer in the transition boiling region was formulated as a position-dependent model. The propagation of the CHF point was strongly dependent on the length of the transition boiling region. Wall-to-fluid film boiling heat transfer was considered to consist of two components: first, a wall-to-vapor convective heat-transfer portion and, second, a wall-to-liquid heat transfer representing near-wall effects. Each contribution was considered separately in ...
1983-10-14
Energy Technology Data Exchange (ETDEWEB)
Purpose: To report on the nephron-sparing, percutaneous ablation of a large renal cell carcinoma by combined superselective embolization and percutaneous radiofrequency ablation. Materials and Methods: A 5 cm renal cell carcinoma of a 43-year-old drug abusing male with serologically proven HIV, hepatitis B and C infection, who refused surgery, was superselectively embolized using microspheres (size: 500 - 700 {mu}m) and a platinum coil under local anesthesia. Percutaneous radiofrequency ablation using a 7F LeVeen probe (size of expanded probe tip: 40 mm) and a 200 Watt generator was performed one day after transcatheter embolization under general anesthesia. Results: The combined treatment resulted in complete destruction of the tumor without relevant damage of the surrounding healthy renal tissue. The patient was discharged 24 hours after RF ablation. No complications like urinary leaks or fistulas were observed and follow up CT one day and 4 weeks after the ...
2001-11-01
`TUNDTEMP` - an advisory tool for the continuous steel casting process
Energy Technology Data Exchange (ETDEWEB)
This report summarizes the major features of the advisory tool `TUNDTEMP`, developed to act as a decision support in the continuous steel casting process. `TUNDTEMP` provides a means to predict abnormal phenomena of temperature origin in the casting that may be difficult to foresee in practical situations. The heart of the system is a semi-empirical calculation model that yields an estimate of the evolution of the tundish temperature of the liquid steel on the basis of a few important casting factors. The user interface of the system is to a large extent based on the visual presentation of the simulated results. The system also contains an optional rule based mechanism that provides assistance in the result interpretation and, if wished, linguistically formulates action recommendations. A separate program has been built for the tuning of the calculation model and for maintenance of the system. At the end of the report, the different tuning parameters are listed and ...
1993-11-01
What density-functional theory can tell us about the spin-density wave in
International Nuclear Information System (INIS)
The energy-versus-volume curve of the spin-density wave (SDW) in body-centred-cubic Cr is calculated with the density functional theory/full-potential linearized augmented plane wave (DFT/FLAPW) method using the generalized gradient approximation (GGA). The predicted ground state is not the SDW, in contrast to an earlier FLAPW calculation. A conjecture is formulated that the widely varying results of the local density approximation (LDA) and GGA - and of different solution methods - can be scaled by the size of the calculated moment. As a consequence, experimentally relevant properties of the SDW can be calculated by tuning the moment. The implications of these results for the ability of DFT to describe Cr are discussed. (author)
2002-04-01
Water resources management in Asia. Volume 1. Main report. World Bank technical paper
Energy Technology Data Exchange (ETDEWEB)
The report, Water Resources Management in Asia, has three objectives: To describe the situation confronting the region's borrowers, devise approaches to better deal with the present and future water related problems that affect their well-being and equip the staff to actively participate in the regional and Bank-wide efforts to strengthen the sector. The principal water resources problems and issues have been placed in four categories: Institutional, long-term management and planning, real-time management and operations, and financial. Such an arrangement provides a perspective for examining concerns across all economic sectors and allows formulation of solutions that will constitute a truly comprehensive, balanced approach to the critical situation encountered in managing these resources. A summary of past Bank activities has confirmed that an historic approach is not adequate to address the pressing problems of today and the future.
1993-01-01
Variational derivation of improved KP-type of equations
Energy Technology Data Exchange (ETDEWEB)
The Kadomtsev-Petviashvili equation describes nonlinear dispersive waves which travel mainly in one direction, generalizing the Korteweg-de Vries equation for purely uni-directional waves. In this Letter we derive an improved KP-equation that has exact dispersion in the main propagation direction and that is accurate in second order of the wave height. Moreover, different from the KP-equation, this new equation is also valid for waves on deep water. These properties are inherited from the AB-equation (E. van Groesen, Andonowati, 2007 ) which is the unidirectional improvement of the KdV equation. The derivation of the equation uses the variational formulation of surface water waves, and inherits the basic Hamiltonian structure.
2010-01-04
Energy Technology Data Exchange (ETDEWEB)
A performance assessment of the operating Solid Waste Storage Area 6 (SWSA 6) facility for the disposal of low-level radioactive waste at the Oak Ridge National Laboratory has been prepared to provide the technical basis for demonstrating compliance with the performance objectives of DOE Order 5820.2A, Chapter 111.2 An analysis of the uncertainty incorporated into the assessment was performed which addressed the quantitative uncertainty in the data used by the models, the subjective uncertainty associated with the models used for assessing performance of the disposal facility and site, and the uncertainty in the models used for estimating dose and human exposure. The results of the uncertainty analysis were used to interpret results and to formulate conclusions about the performance assessment. This paper discusses the approach taken in analyzing the uncertainty in the performance assessment and the role of uncertainty in performance assessment.
1994-12-31
Energy Technology Data Exchange (ETDEWEB)
Courant-Snyder (CS) theory for one degree of freedom has recently been generalized by Qin and Davidson to the case of coupled transverse dynamics with two degrees of freedom. The generalized theory has four basic components of the original CS theory, i.e., the envelope equation, phase advance, transfer matrix, and the CS invariant, all of which have their counterparts in the original CS theory with remarkably similar expressions and physical meanings. In this brief communication, we further extend this remarkable similarity between the original and generalized CS theories and construct the Twiss parameters and beam matrix in generalized forms for the case of a strong coupling system.
2010-07-01
International Nuclear Information System (INIS)
A numerical and experimental investigation is carried out in a solar thermochemical reactor for the thermal dissociation of ZnO at 2000 K using concentrated solar energy. The reactor consists of a cavity-receiver lined with ZnO particles and directly exposed to high-flux irradiation. A transient heat transfer model is formulated to link the rate of radiation, convection, and conduction heat transfer to the reaction kinetics. The radiosity and Monte Carlo methods are applied to obtain the distribution of net radiative fluxes at the internal surfaces of the reactor cavity and at the surface of the ZnO bed. Validation is accomplished in terms of the calculated and measured transient temperature profiles and chemical reaction rates.
2008-04-01
We formulate a complete theory of Edge Radiation based on a novel method relying on Fourier Optics techniques. Similar types of radiation like Transition Undulator Radiation are addressed in the framework of the same formalism. Special attention is payed in discussing the validity of approximations upon which the theory is built. Our study makes consistent use of both similarity techniques and comparisons with numerical results from simulation. We discuss both near and far zone. Physical understanding of many asymptotes is discussed. Based on the solution of the field equation with a tensor Green's function technique, we also discuss an analytical model to describe the presence of a vacuum chamber. In particular, explicit calculations for a circular vacuum chamber are reported. Finally, we consider the use of Edge Radiation as a tool for electron beam diagnostics. We discuss Coherent Edge Radiation, Extraction of Edge Radiation by a mirror, and other issues ...
2008-01-01
The physics of tachyons. Part 4. Tachyon electrodynamics
Energy Technology Data Exchange (ETDEWEB)
A new formulation of the theory of tachyons using the same two postulates as in special relativity is applied to the electrodynamics of material media. A discussion of Lagrange`s equations and Hamilton`s equations for `classical` charged tachyons shows that such a formalism is a viable approach. An essay is included on why tachyons can be considered to be localised particles for the purpose of calculations. Tachyonic transformations of the electromagnetic fields D, P, H and M are shown to be the same as for bradyonic transformations. Examples discussed include the electric dipole moment of a tachyonic current loop, constitutive equations, polarisation in tachyonic dielectric materials and the velocity of light in tachyonic dielectric media. This is followed by discussions of the collision energy loss for charged tachyons interacting with a material medium and a mathematical proof that tachyons cannot emit Cherenkov radiation when passing through a bradyonic ...
1998-12-31
The physics of tachyons. Part 4. Tachyon electrodynamics
International Nuclear Information System (INIS)
A new formulation of the theory of tachyons using the same two postulates as in special relativity is applied to the electrodynamics of material media. A discussion of Lagrange's equations and Hamilton's equations for 'classical' charged tachyons shows that such a formalism is a viable approach. An essay is included on why tachyons can be considered to be localised particles for the purpose of calculations. Tachyonic transformations of the electromagnetic fields D, P, H and M are shown to be the same as for bradyonic transformations. Examples discussed include the electric dipole moment of a tachyonic current loop, constitutive equations, polarisation in tachyonic dielectric materials and the velocity of light in tachyonic dielectric media. This is followed by discussions of the collision energy loss for charged tachyons interacting with a material medium and a mathematical proof that tachyons cannot emit Cherenkov radiation when passing through a bradyonic ...
British Library Electronic Table of Contents (United Kingdom)
Similar to many other countries, an educational reform anchored in a managerial discourse was proposed in Israel in 2004 by the Dovrat Committee, encouraged by the 'inter-state education gap' social problem that economist Dan Ben-David formulated on the basis of international examinations, such as PISA and TIMMS. Through a neo-Weberian approach this study follows the construction of a managerial discourse from the 1970s onwards that led to the Dovrat report. In the first period, managerial discourse was constructed around decentralization, parent choice and school autonomy 'social objects' by an expanding reformist network of educational scholars and figures from the Ministry of Education and local authorities. The pervasion of managerial discourse paved the way for the nomination of Shlom...
2011-01-01
International Nuclear Information System (INIS)
A Consultants' Meeting on 'The assessment of soil conservation technologies for sustainable agricultural production' was held in Vienna at the IAEA Headquarters from May 28-30, 2001. The consultants' presentations reviewed recent advances in the use of fallout radionuclides to measure soil erosion as well as approaches and technologies applied for soil conservation worldwide. Also, activities and experiences of FAO and UNEP in the field of land degradation, soil conservation and related issues were presented. Based on the information provided by the Scientific Secretary, a full project proposal was prepared during the second part of the Consultants' Meeting. The consultants also provided recommendations on the formulation and implementation of a future CRP on the subject.
2001-05-28
The Stefan problem solved via conjugate gradient-like iterative methods on a parallel vector machine
The aim of this paper is to illustrate the validity and efficiency of iterative methods for solving large linear systems arising from the finite element discretization of the equation governing conduction-controlled solidification processes. Starting from the basic enthalpy equation, two alternative formulations are obtained and fixed-grid finite element discretizations are developed. These discretizations yield a set of nonlinear equations that are linearized using the Newton-Raphson scheme. The linearized equations are used as a basis for evaluating different iterative methods of the conjugated gradient type. Symmetric scaling and incomplete factorization preconditioning of the linear equations are used to improve the convergence properties of the iterative methods. Vectorization and parallelization are also employed to make full use of the CRAY-2 supercomputer. The results indicate that the implementation of currently available iterative solvers leads to ...
1991-01-01
Systematic approach to consider system contingencies in PSS design
Energy Technology Data Exchange (ETDEWEB)
This paper proposes a method that can incorporate system contingencies into power system stabilizer (PSS) design. Selection of critical contingencies is first performed by a ranking of contingencies under a wide range of operating conditions according to a small signal stability index. A multi-objective optimization model is formulated to pursue satisfactory system damping performance under both pre-contingency and post-contingency situations. A recursive Genetic Algorithm is then presented to tune the PSS parameters so that the dynamic security criteria subject to contingencies are met under a wide range of operating conditions. Finally, an eight-machine system is utilized to demonstrate the effectiveness of the proposed approach and a comparison of the proposed method with a pre-contingency tuning scheme is reported. (author)
2009-12-15
System performance of a solar thermophotovoltaic system for space and terrestrial application
Energy Technology Data Exchange (ETDEWEB)
Solar thermophotovoltaics (STPV) potentially have high system power efficiency together with other attractive attributes for both space and terrestrial applications. This paper presents a summary of work that has been conducted by NASA Lewis Research Center (LeRC) and McDonnell Douglas Aerospace (MDA). The paper discusses analytical modeling and subsystem testing, laboratory, and field testing that has been conducted. The features which make solar thermophotovoltaics attractive for both space and terrestrial applications are discussed. Based upon these investigations and the work of others, a conceptual design has been formulated, and an estimate of system performance is presented. This estimate indicates a solar thermophotovoltaics system can result in competitive energy costs for the utility electrical market applications and a high power-to-mass ratio for space power applications.
1995-12-31
British Library Electronic Table of Contents (United Kingdom)
In this article, we describe a method used to prepare an in situ sodium-activated, organomodified bentonite clay/styrene-butadiene rubber nanocomposite master batch via a latex blending technique. The clay master batch was used for compound formulation. Octadecyl amine was used as an organic intercalate. The clay was purchased from local suppliers and was very cheap. Sodium chloride was used for in situ activation of the clay. The wide-angle X-ray diffraction data indicated that the in situ sodium activation helped to increase the intergallery distance from 1.28 to 1.88 nm. A transmission electron micrograph indicated intercalation and partial exfoliation. The thermal properties were relatively better in the case of the sodium-activated, organomodified bentonite-clay-containing compound. A...
2009-01-01
British Library Electronic Table of Contents (United Kingdom)
The viability of Anopheles gambiae sensu stricto and Anopheles arabiensis (Diptera: Culicidae) eggs over time and the ovicidal activity of Beauveria bassiana (Ascomycota: Cordycipitaceae) and Metarhizium anisopliae (Ascomycota: Clavicipitaceae) were investigated. Eggs were incubated in soil or leaf litter for up to 12?weeks at 26?C and 75%, 86% or >98% relative humidity (RH). Eggs were treated topically with M. anisopliae ICIPE-30 or B. bassiana I93-825 conidia in either water or oil-in-water formulations. Survival of eggs whether treated or not with fungus was similar, and untreated eggs generally did not survive longer than 2?weeks regardless of the substrate or humidity tested. After a minimal 5-day exposure, M. anisopliae at 5???106?conidia/cm2 clearly reduced the number of larvae. The...
2011-01-01
Surface characteristics and overlaying properties of flat-pressed wood plastic composites
British Library Electronic Table of Contents (United Kingdom)
This study evaluated surface characteristics and overlaying properties of wood plastic composite (WPC) panels made from dry-blended rubber wood fiber-polypropylene (PP) powder formulations using a conventional flat-press process under laboratory conditions. Three levels of rubberwood fibers (Hevea brasiliensis), 40%, 50%, and 60%, based on the composition by weight, were mixed with the PP powder without and with 3% (based on weight) maleic anhydride grafted PP (MAPP) as a coupling agent. Contact angle measurements on the WPC samples were performed using a goniometer connected with a digital camera which collected one image per second. Roughness measurements, average roughness (R a), mean peak-to-valley height (R z), and maximum roughness (R y), were taken from the sanded samples along and ...
2011-01-01
Structure of Mgn and Mg n + clusters up to n = 30
British Library Electronic Table of Contents (United Kingdom)
We present structure calculations of neutral and singly ionized Mg clusters of up to 30 atoms, as well as Na clusters of up to 10 atoms. The calculations have been performed using density functional theory (DFT) within the local (spin-)density approximation, ion cores are described by pseudopotentials. We have utilized a new algorithm for solving the Kohn-Sham equations that is formulated entirely in coordinate space and, thus, permits straightforward control of the spatial resolution. Our numerical method is particularly suitable for modern parallel computer architectures; we have thus been able to combine an unrestricted simulated annealing procedure with electronic structure calculations of high spatial resolution, corresponding to a plane-wave cutoff of 954 eV for Mg. We report the geo...
2011-01-01
International Nuclear Information System (INIS)
In this paper, steady-state isotopic transient kinetic analysis (SSITKA) is used to study two model reactions, CO oxidation and CO-NO reactions, on a typical formulation of a three-way auto-catalyst. Under steady-state conditions, abrupt switches in the isotopic composition of CO ("1"2C"1"6O/"1"3C"1"8O) were carried out to produce isotopic transients in both labeled reactants and products. Along with the determination of the average surface lifetimes and concentrations of reaction intermediates, an analysis of the transient responses along the carbon reaction pathway indicated that the distribution of active sites for the formation of CO_2 was bimodal for both reactions. Furthermore, relatively few surface sites contributed to the overall reaction rate.
1991-08-25
Soil-vegetation-atmosphere transfer modeling
Energy Technology Data Exchange (ETDEWEB)
In this study the soil/vegetation/atmosphere-model based on the formulation of Deardorff was refined to hour basis and applied to a field in Vihti. The effect of model parameters on model results (energy fluxes, temperatures) was also studied as well as the effect of atmospheric conditions. The estimation of atmospheric conditions on the soil-vegetation system as well as an estimation of the effect of vegetation parameters on the atmospheric climate was estimated. Areal surface fluxes, temperatures and moistures were also modelled for some river basins in southern Finland. Land-use and soil parameterisation was developed to include properties and yearly variation of all vegetation and soil types. One classification was selected to describe the hydrothermal properties of the soils. Evapotranspiration was verified against the water balance method
1996-12-31
Simplification of Finite Element Models for Structures Having a Beam-Like Behaviour
A method for simplifying finite element models of structures having a beam-like global dynamical behaviour is presented. This method is based on the use of a general uniform beam finite element formulation. It takes into account both transverse shear effects and dynamical coupling between bending and torsion due to the fact that mass centres and shear centres do not always coincide. For that purpose, we develop a condensation method for reducing any shell model into an equivalent beam, as well as a technique for automatically identifying the corresponding set of beam parameters. The method is applied to several illustrate examples that demonstrate its ability to simplify finite element models for many kinds of sophisticated structures having a beam-like predominant behaviour.
2000-04-01
Energy Technology Data Exchange (ETDEWEB)
Ag nanoparticles were prepared in a water-phase system with a mixture of silver-ammonia complex, sodium borohydride, and lauric acid according to molar feed ratio of approximately 6:3:1. The mechanism of preparation and separation by chemical reduction-protection method was explored. The as-synthesized Ag nanoparticles were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and UV-vis spectroscopy, respectively. It was found that the size of high purity Ag particles was ranging from 30 to 50 nm with slight agglomeration. In addition, the as-synthesized wet Ag nanoparticles were dispersed stably in organic vehicle to formulate electrically conductive nanopaste. Upon direct-written and sintered, the array pattern of the nanopaste with the resolution of about 30 {mu}m was achieved with the electrical resistivity in the order of magnitude of 10{sup -5} {Omega} cm.
2010-04-02
Risk trade-off linked to temporary storage function in road transports
British Library Electronic Table of Contents (United Kingdom)
Today?s demand on high supply chain performance requires higher awareness about supply chain risks and uncertainty. The purpose of this paper is to analyse the role of temporary storage in the transport network in a supply chain perspective. The primary research question concerns the purpose or role of temporary storage and whether management of temporary storage can contribute to reducing risks and uncertainty in the supply chain. The research is based on a system-theoretical approach, which emphasizes a holistic view instead of the characteristics of the different parts. The research method used in this paper is abductive. Existing theories are used to formulate a framework which leads to a conceptual model description of the temporary storage function. This model is then supported and v...
2011-01-01
Response to Kowalczynski on tachyons
Energy Technology Data Exchange (ETDEWEB)
The author answers and briefly and comment upon a paper on tachyons by J.K. Kowalczynski. Suitable answers are already contained in the recent literature about extended relativity (ER), apparently unknown to that author. His answer is threefold. (1) About causality: No paradoxes can be sensible discussed without studying in detail the tachyon-exchange dynamics; but once one knows tachyon mechanics, the solution of the paradox is straightforward. As an example, he exploits and solves the Tolman-Regge paradox. (2) About superluminal frames and transformations: I agrees that (as I has noted elsewhere) in four dimensions such language is unfortunate; it was borrowed from two dimensions, where it is completely justified. Formulations in terms of a new language can be found in my recent papers on ER. (3) The statement that the pseudo-Euclidean space-time is a particular Riemannian manifold is wrong. It is pseudo-Riemannian, or Lorentzian. When dealing with tachyons the ...
1987-09-01
Response to Kowalczynski on tachyons
International Nuclear Information System (INIS)
The author answers and briefly and comment upon a paper on tachyons by J.K. Kowalczynski. Suitable answers are already contained in the recent literature about extended relativity (ER), apparently unknown to that author. His answer is threefold. (1) About causality: No paradoxes can be sensible discussed without studying in detail the tachyon-exchange dynamics; but once one knows tachyon mechanics, the solution of the paradox is straightforward. As an example, he exploits and solves the Tolman-Regge paradox. (2) About superluminal frames and transformations: I agrees that (as I has noted elsewhere) in four dimensions such language is unfortunate; it was borrowed from two dimensions, where it is completely justified. Formulations in terms of a new language can be found in my recent papers on ER. (3) The statement that the pseudo-Euclidean space-time is a particular Riemannian manifold is wrong. It is pseudo-Riemannian, or Lorentzian. When dealing with tachyons the ...
British Library Electronic Table of Contents (United Kingdom)
The paper deals with the reliability-based design optimization (RBDO) of a riser support installed on a floating production storage and offloading (FPSO) unit under operation, extreme, damaged, and one line failure cases and installation loading conditions. The optimization problem is formulated such that probabilistic thickness variables described with random characteristics are determined by minimizing the weight of the riser support structure subjected to stress constraints for the given target reliability. The initial design model is generated based on actual FPSO riser support specifications. The finite element analysis is conducted using NASTRAN, and the probabilistic optimal solutions are obtained via the moving least squares method in the context of RBDO using a response surface me...
2011-01-01
Radiation protection and the role of TSOs in Kenya
International Nuclear Information System (INIS)
Since the late '60s and through the early '90s Kenya has always recognized and appreciated the need for support from Technical and Scientific Support Organizations (TSOs) for activities geared towards enhancing nuclear and radiation safety. The TSOs have since then gained increasing importance for provision of technical and scientific basis for policy formulation, implementation and legislation with regard to radiation safety. National and specific operator programmes on safety and security of radiation source and radioactive waste recognize and encourage the active participation of TSOs. Due to the role they play, technical competence, transparency and the observance of ethical practices have become essential both for the regulator and the regulated. In this respect, interaction and cooperation between stake holders (regulatory authorities, users of radiation, generators of radioactive waste, professional organizations) and TSOs, in the frame of national and ...
2007-08-01
Energy Technology Data Exchange (ETDEWEB)
Research facilities and personnel in high efficiency separation processes for carbon dioxide removal from industrial sources, such as fossil fuel fired power stations, goal gasification plants, and hydrogen production units for enhanced oil recovery applications at the University of Regina were described. A brief summary of current projects, such as the determination of CO{sub 2} absorption capacity of sterically hindered amines, the formulation of high CO{sub 2} absorption capacity solvents, the search for high performance absorbers and regenerators, studies on material corrosion, and optimization and cost studies of co-production of CO{sub 2} and electricity, was also provided.
1997-02-01
Quantization of coupled 1D vector modes in integrated photonic waveguides
International Nuclear Information System (INIS)
A quantum mechanical analysis of the guided light in integrated photonics waveguides is presented. The analysis is made starting from one-dimensional (1D) guided vector modes by taking into account the modal orthonormalization property on a cross section of an optical waveguide, the vector structure of the guided optical modes and the reversal-time symmetry in order to quantize the 1D vector modes and to derive the quantum momentum operator and the Heisenberg equations. The results provide a quantum-consistent formulation of the linear and nonlinear quantum light propagations as a function of forward and backward creation and annihilation operators in integrated photonics. As an illustration, an application to an integrated nonlinear directional coupler is given, that is, both the nonlinear momentum and the Heisenberg equations of the nonlinear coupler are derived.
2008-06-01
Properties and processing of TIMETAL LCB
TIMETAL LCB was introduced more than 10 years ago targeting automotive suspension spring applications. The alloy development aim was to use a low-cost formulation by selecting less expensive raw materials than typical beta titanium alloys. Following the first successful application of TIMETAL LCB suspension springs to series production vehicles, the 2000 Volkswagen Lupo FSI, the springs have been used for Ferrari Challenge Stradale since 2003. The most recent development effort was focused on the generation of metallurgical and mechanical service data for the alloy, and the implementation of efficient low cost processing of coils. This paper will introduce various properties of TIMETAL LCB products that can be useful in the design and the consideration of spring applications. Recent progress in the processing of TIMETAL LCB will also be introduced and discussed.
2005-12-01
Energy Technology Data Exchange (ETDEWEB)
It was developed a new formulation of macro aggregates of Samarium 153 ({sup 153} Sm-MH) for the arthropaties treatment. The radio pharmaceutic was prepared by reaction of Samarium 153 chloride (SmCl{sub 3}) in aqueous environment with sodium boron hydride in NaOH 0.5 N. The microscopic analysis shown that the particles have an average size of 4% m (range 1-14 {mu} m). The velocity of sedimentation was 0.008 cm/min with high stability in vitro in human serum. The biological studies in healthy rabbits, shown that the complex is retained inside the articulation still eight days after of the administration of the radiopharmaceutical. Likewise, it is presented the data of absorbed dose in the different target organs, which was determined by thermoluminescent dosimetry (TLD) through the use of a REMCAL phantom (radiation equivalent manikin calibration). (Author)
1999-07-01
British Library Electronic Table of Contents (United Kingdom)
This work deals with a new route to modify polymer blend morphology in order to improve the porosity of gas diffusion layers (GDLs) for proton exchange membrane fuel cells (PEMFCs). First, electrically conductive polymer-based blends were carefully formulated using a twin-screw extrusion process. Blend electrical conductivity was ensured by the addition of high specific surface area carbon black and synthetic graphite flakes. Final GDL porosity, in particular its macroporosity, was generated by melt blending polyamide 11 (PA11) matrix with polystyrene (PS) followed by PS extraction with tetrahydrofuran (THF) solvent at room temperature. In order to improve GDL porosity by the optimisation of PS dispersion in the PA11 matrix, PA11/PS blends were compatibilised by the addition of 2 wt.-% of ...
2007-01-01
British Library Electronic Table of Contents (United Kingdom)
Abstract Objectives- Cyclodextrins are useful solubilizing excipients that have gained currency in the formulator's armamentarium based on their ability to temporarily camouflage undesirable physicochemical properties. In this context cyclodextrins can increase oral bioavailability, stabilize compounds to chemical and enzymatic degradation and can affect permeability through biological membranes under certain circumstances. This latter property is examined herein as a function of the published literature as well as work completed in our laboratories. Key findings- Cyclodextrins can increase the uptake of drugs through biological barriers if the limiting barrier component is the unstirred water layer (UWL) that exists between the membrane and bulk water. This means that cyclodextrins are mo...
2011-01-01
Performance of ceramics in ring/cylinder applications
Energy Technology Data Exchange (ETDEWEB)
In support of the efforts to apply ceramics to advanced heat engines, a study is being performed of the performance of ceramics at the ring/cylinder interface of advanced (low heat rejection) engines. The objective of the study, managed by the Oak Ridge National Laboratory, is to understand the basic mechanisms controlling the wear of ceramics and thereby identify means for applying ceramics effectively. Attempts to operate three different zirconias, silicon carbide, silicon nitride, and plasma-sprayed ceramic coatings without lubrication have not been successful because of excessive friction and high wear rates. Silicon carbide and silicon nitride perform well at ambient temperatures with fully formulated mineral oil lubrication, but are limited to temperatures of 500F because of the lack of suitable liquid lubricants for higher temperatures.
1987-01-01
Passivity of iron in red mud's water solutions
International Nuclear Information System (INIS)
Red mud suspensions are studied as passivating agents for iron in alkaline chloride media. Red mud particles in alkaline media are negatively charged, and can absorb considerable amounts of protons without significant changes in pH. These particles adhere easily to an iron surface forming aggregates of heterogeneous shape, smaller than 10 #mu#mx10 #mu#m. These adhered particles recrystallise on potential cycling, and hinder metal dissolution and magnetite formation. Carbon steel samples passivated in red mud suspensions become resistant to corrosion in alkaline chloride media. Corrosion potential versus time records and impedance spectroscopy measurements allow formulating some hypotheses about the inhibiting mechanism.
2004-07-30
Passivity of iron in red mud's water solutions
Energy Technology Data Exchange (ETDEWEB)
Red mud suspensions are studied as passivating agents for iron in alkaline chloride media. Red mud particles in alkaline media are negatively charged, and can absorb considerable amounts of protons without significant changes in pH. These particles adhere easily to an iron surface forming aggregates of heterogeneous shape, smaller than 10 {mu}mx10 {mu}m. These adhered particles recrystallise on potential cycling, and hinder metal dissolution and magnetite formation. Carbon steel samples passivated in red mud suspensions become resistant to corrosion in alkaline chloride media. Corrosion potential versus time records and impedance spectroscopy measurements allow formulating some hypotheses about the inhibiting mechanism.
2004-07-30
British Library Electronic Table of Contents (United Kingdom)
This paper analyzes the F-policy M/M/1/K queueing system with working vacation and an exponential startup time. The F-policy deals with the issue of controlling arrivals to a queueing system, and the server requires a startup time before allowing customers to enter the system. For the queueing systems with working vacation, the server can still provide service to customers rather than completely stop the service during a vacation period. The matrix-analytic method is applied to develop the steady-state probabilities, and then obtain several system characteristics. We construct the expected cost function and formulate an optimization problem to find the minimum cost. The direct search method and Quasi-Newton method are implemented to determine the optimal system capacity K, the optimal thre...
2010-01-01
Opportunistic Cooperation in Cognitive Femtocell Networks
We investigate opportunistic cooperation between unlicensed secondary users and legacy primary users in a cognitive radio network. Specifically, we consider a model of a cognitive network where a secondary user can cooperatively transmit with the primary user in order to improve the latter's effective transmission rate. In return, the secondary user gets more opportunities for transmitting its own data when the primary user is idle. This kind of interaction between the primary and secondary users is different from the traditional dynamic spectrum access model in which the secondary users try to avoid interfering with the primary users while seeking transmission opportunities on vacant primary channels. In our model, the secondary users need to balance the desire to cooperate more (to create more transmission opportunities) with the need for maintaining sufficient energy levels for their own transmissions. Such a model is applicable in the emerging area of cognitive femtocell networks. ...
2011-01-01
Online consumer communities, collaborative learning and innovation
British Library Electronic Table of Contents (United Kingdom)
Purpose - The paper aims to outline the managerial challenges faced by the organizations interested in leveraging knowledge and creative talent embedded in online customers' communities to sustain innovation in b-2-c industries. Design/methodology/approach - Through a detailed case study analysis of a leading food producer who launched an online open collaborative platform to gather users' idea for new products the paper aims to highlight the transformational effort that firms have to make in order to leverage knowledge absorption from customers in the context of innovation. Findings - The paper suggests potential strategies for conventional companies to engage consumers in knowledge (co-creation) and collaborative innovation processes, formulating some hypothesis that could support an int...
2011-01-01
On the Initiation Mechanism in Exploding Bridgewire and Laser Detonators
Since its invention by Los Alamos during the Manhattan Project era the exploding bridgewire detonator (EBW) has seen tremendous use and study. Recent development of a laser-powered device with detonation properties similar to an EBW is reviving interest in the basic physics of the deflagration-to-detonation (DDT) process in both of these devices. Cutback experiments using both laser interferometry and streak camera observations are providing new insight into the initiation mechanism in EBWs. These measurements are being correlated to a DDT model of compaction to detonation and shock to detonation developed previously by Xu and Stewart. The DDT model is incorporated into a high-resolution, multi-material model code for simulating the complete process. Model formulation and the modeling issues required to describe the test data will be discussed.
2006-07-01
British Library Electronic Table of Contents (United Kingdom)
SummaryA meshless numerical model is proposed to investigate shallow-water dam break flows in 1D open channels. The numerical model is to solve the shallow water equations (SWE) based on smoothed particle hydrodynamics (SPH). The concept of slice water particles (SWP) is adopted in the SPH-SWE formulation. The numerical sensitivity analysis is first performed to study the appropriate SWP number and variable smoothing length through dam break flows in an idealized 1D channel with dry/wet beds. Extensive validation by comparison with laboratory and field data is next conducted for four benchmark problems, including dam break flows through a rough flat channel, a rough bumpy channel with various downstream boundary conditions, a nonprismatic channel, and a realistic scale model of the Toce ri...
2011-01-01
Nuclear reaction rates and opacity in massive star evolution calculations
International Nuclear Information System (INIS)
Nuclear reaction rates and opacity are important parameters in stellar evolution. The input physics in a stellar evolution code determines the main theoretical characteristics of the stellar structure, evolution and nucleosynthesis of a star. For different input physics, in this work we calculate stellar evolution models of very massive first stars during the hydrogen and helium burning phases. We have considered 100 and 200M_sun galactic and pregalactic stars with metallicity Z = 10"-"6 and 10"9, respectively. The results show important differences from old to new formulations for the opacity and nuclear reaction rates, in particular the evolutionary tracks are significantly affected, that indicates the importance of using up to date and reliable input physics. The triple alpha reaction activates sooner for pregalactic than for galactic stars.
2010-07-01
British Library Electronic Table of Contents (United Kingdom)
The first automated method for the determination of mexiletine hydrochloride - an antiarrhythmic agent - is reported. The method is based on the reaction of the analyte with o-phthalaldehyde (OPA) in the presence of sulfite in basic medium using a sequential injection (SI) manifold. The reaction product was monitored spectrofluorimetrically (lex=350nm/lem=446nm). A simple and effective on-line dilution approach was adopted in order to expand the linearity and apply the method to assay, dosage uniformity and dissolution tests with minimum sample preparation. Chemical (pH, amount concentrations of OPA and sulfite) and instrumental variables (temperature, flow rate, injection volumes, etc.) that affected the determination were studied. The developed assay was validated in terms of linearity, ...
2008-01-01
Selected applications of novel techniques in Agricultural Biotechnology, Health Food formulations and Medical Biotechnology are being reviewed with the aim of unraveling future developments and policy changes that are likely to open new markets for Biotechnology and prevent the shrinking or closing of existing ones. Amongst the selected novel techniques with applications in both Agricultural and Medical Biotechnology are: immobilized bacterial cells and enzymes, microencapsulation and liposome production, genetic manipulation of microorganisms, development of novel vaccines from plants, epigenomics of mammalian cells and organisms, and biocomputational tools for molecular modeling related to disease and Bioinformatics. Both fundamental and applied aspects of the emerging new techniques are being discussed in relation to their anticipated, marked impact on future markets and present policy changes that are needed for success in either Agricultural or Medical ...
2004-01-01
Non-relativistic Fermions, Coadjoint Orbits of \\winf\\ and String Field Theory at $c=1$
We apply the method of coadjoint orbits of \\winf-algebra to the problem of non-relativistic fermions in one dimension. This leads to a geometric formulation of the quantum theory in terms of the quantum phase space distribution of the fermi fluid. The action has an infinite series expansion in the string coupling, which to leading order reduces to the previously discussed geometric action for the classical fermi fluid based on the group $w_\\infty$ of area-preserving diffeomorphisms. We briefly discuss the strong coupling limit of the string theory which, unlike the weak coupling regime, does not seem to admit of a two dimensional space-time picture. Our methods are equally applicable to interacting fermions in one dimension.
1992-01-01
Non-Gaussian gravitational clustering field statistics
In this work we investigate the multivariate statistical description of the matter distribution in the nonlinear regime. We introduce the multivariate Edgeworth expansion of the lognormal distribution to model the cosmological matter field. Such a technique could be useful to generate and reconstruct three-dimensional nonlinear cosmological density fields with the information of higher order correlation functions. We explicitly calculate the expansion up to third order in perturbation theory making use of the multivariate Hermite polynomials up to sixth order. The probability distribution function for the matter field includes at this level the two-point, the three-point and the four-point correlation functions. We use the hierarchical model to formulate the higher order correlation functions based on combinations of the two-point correlation function. This permits us to find compact expressions for the skewness and kurtosis terms of the expanded lognormal field ...
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
We investigated the use of Surface Free Energy (SFE) measurements, describing coherence between surfaces of two solids, in evaluation of affinity between skin surface and foundation, a possible predictor of makeup longevity. We found that the gp values of skin varied significantly among subjects. After discovering that the SFE values of most available conventional foundation products were very different from that of skin, specially formulated experimental foundations with SFE values close to that of the skin surface were prepared using conventional powder ingredients and novel powder ingredients coated with polyethylene glycol. In our usage tests, the SFE-controlled foundations demonstrated superior performance to that of conventional foundations and most of subjects preferred the SFE-cont...
2009-01-01
Network-aware service placement and selection algorithms on large-scale overlay networks
British Library Electronic Table of Contents (United Kingdom)
Currently many service providers offer their services on a private and proprietary hard- and software infrastructure. These infrastructures often share many similarities. Hence we believe a generic service management architecture, that allows service providers to offer a large array of different services on a single infrastructure or multiple providers to offer their services cooperatively, would provide many advantages over current silo-based approaches. Additionally, by allowing the distributed service management components to cooperate in a peer-to-peer overlay network, scalability and resilience of the system could be greatly improved. In this paper we propose an optimal algorithm, based on an integer linear programming (ILP) formulation, and several heuristics to support such a generi...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
The effects of thermal radiation and viscous dissipation on magneto-hydrodynamic (MHD) unsteady free-convection flow over a semi-infinite vertical porous plate are analysed. The fluid considered is non-gray (absorption coefficient dependent on wave length). The Network Simulation Method is used to solve the boundary-layer equations based on the finite-difference formulation; only discretization of the spatial co-ordinates is necessary, while time remains as a real continuous variable. This method provides a solution for both transient and steady-state problems at the same time, and programming does not require manipulation of the sophisticated mathematical software that is inherent in other numerical methods. The velocity, temperature, local skin-friction and local Nusselt number are studi...
2007-01-01
Mulled coal: A beneficiated coal form for use as a fuel or fuel intermediate
Energy Technology Data Exchange (ETDEWEB)
Energy International is developing a technology that will create a staged formulation with the first coal form (Mulled Coal) that can be stored, transported, and pumped. Just prior to combustion, the Mulled Coal (MC) would be modified to provide the properties needed for proper atomization. This concept is an alternative to the expensive and energy intensive thermal drying processing of fine coal wet cakes. The material is suitable for both direct feed use in conventional and fluid bed combustors as well as on-site conversion to combustible slurries. By maintaining the coal form relatively close to the feed wet cake, only minor processing with low additive levels and low energy blending needed at the point of production. Its conversion to slurry or other use-feed form is made near the time of use and thus the requirements for stability, climatic control, and other storage, transport, and handling requirements are much less severe.
1991-10-01
Modeling of snow melting and uniform wetting front migration in a layered subfreezing snowpack
Energy Technology Data Exchange (ETDEWEB)
A method of modeling freeze-thaw cycles of naturally deposited snowpacks is presented. The model involves the Stefan condition as an independent governing equation on the exterior moving boundary to calculate snowpack thinning, flow of water through a variably saturated layered porous medium as described by the Richards equation, and heat conduction with a phase change. The heat conduction problem was treated in two ways. Local heat conduction between a snow grain and its surrounding water film was treated by using a simple energy balance. Global heat conduction with a phase change (the Stefan problem) was introduced to calculate the space-time temperature distribution. In order to handle multiple interior moving boundaries, a specific form of the enthalpy formulation was used for heat conduction with a phase change. Changing material properties were considered according to the calculated meltwater refreezing. 48 refs., 11 figs., 2 tabs.
1994-08-01
Modeling of Valveless Micropumps
British Library Electronic Table of Contents (United Kingdom)
There are two difficulties encountered in modeling valveless micropumps using lumped-element methods. The pressure loss coefficient for fluidic diodes used in valveless pumps to rectify flow depends on the flow direction. A problem arises in choosing the proper loss correlation because the flow direction is not known a priori. Another problem is the quadratic form of the equation for the flow through the fluidic diodes, which brings about multiple solutions. The above problems become even more serious in multi-chamber cases. They are overcome in this study by suitably formulating the flow resistance. In addition, the flow inertia is accounted for in the unsteady model. The steady and unsteady models are evaluated by comparing with CFD simulations, which also serve to illustrate the flow fi...
2009-01-01
Microstructure and properties of ultrafine WC-10Co composites with chemically doped VC
British Library Electronic Table of Contents (United Kingdom)
Vanadium carbide is the most effective grain growth inhibitor for ultrafine WC-Co composites due to its high solubility and mobility in the cobalt phase at relatively low temperatures; however, there are still some debates over the best way to introduce it into the WC-Co formulation. In this paper, the differences between admixed and chemically doped grain growth inhibitors on the microstructural development and properties of an ultrafine WC-10Co composite are discussed. The densification rate of chemically doped samples is slower in the early stage of sintering and the WC grain sizes of the sintered alloys are finer than those of admixed samples, leading to the increase of hardness and transverse rupture strength of the sintered alloys. The effectiveness of the chemically doped inhibitor ...
2011-01-01
Matrix models as CFT: Genus expansion
International Nuclear Information System (INIS)
We show how the formulation of the matrix models as conformal field theories on a Riemann surfaces can be used to compute the genus expansion of the observables. Here we consider the simplest example of the Hermitian matrix model, where the classical solution is described by a hyperelliptic Riemann surface. To each branch point of the Riemann surface we associate an operator which represents a twist field dressed by the modes of the twisted boson. The partition function of the matrix model is computed as a correlation function of such dressed twist fields. The perturbative construction of the dressing operators yields a set of Feynman rules for the genus expansion, which involve vertices, propagators and tadpoles. The vertices are universal, the propagators and the tadpoles depend on the Riemann surface. As a demonstration we evaluate the genus-two free energy using the Feynman rules.
2010-10-01
Mathematical modeling of the behavior of geothermal systems under exploitation
Energy Technology Data Exchange (ETDEWEB)
Analytical and numerical methods have been used in this investigation to model the behavior of geothermal systems under exploitation. The work is divided into three parts: (1) development of a numerical code, (2) theoretical studies of geothermal systems, and (3) field applications. A new single-phase three-dimensional simulator, capable of solving heat and mass flow problems in a saturated, heterogeneous porous or fractured medium has been developed. The simulator uses the integrated finite difference method for formulating the governing equations and an efficient sparse solver for the solution of the linearized equations. In the theoretical studies, various reservoir engineering problems have been examined. These include (a) well-test analysis, (b) exploitation strategies, (c) injection into fractured rocks, and (d) fault-charged geothermal reservoirs.
1982-01-01
Magnetism and recoilless fraction in metallic glasses after laser irradiation
British Library Electronic Table of Contents (United Kingdom)
Samples of Fe78B13Si9 (Metglas 2605 TCA) and Fe77Cr2B16Si5 (Metglas 2605 S3A) were exposed to pulsed excimer laser irradiation at repetition rates of 15, 25 and 50Hz. The occurrence of out-of-plane magnetic anisotropy, changes in the average hyperfine magnetic field and width of the hyperfine field distribution were evidenced by transmission Mossbauer spectroscopy. The variation of the recoilless fraction with laser processing parameters was derived from the simultaneous recording of Mossbauer spectra using a stainless steel etalon as a dual absorber. Conclusions on the onset of long-range magnetic order were formulated.
2010-01-01
Low-level radioactive waste disposal in the oceans
Energy Technology Data Exchange (ETDEWEB)
A strategy for the management of the disposal of low-level radioactive wastes into coastal zones and ocean waters has developed over the past three decades. While there has been a substantial increase in the number of international and required agreements there has also been a concomitant improvement in our understanding of the ocean and the processes at work within it. This has allowed more rigorous and reliable assessments to be made of the radiological consequences. With the continued development of basic guidelines of radiological protection by the International Commission on Radiological Protection (ICRP) methodologies have been formulated to derive the fundamental scientific requirement - the relationship between disposal or release rate to the ocean and the resultant radiation dose to exposed human populations.
1983-04-01
Interplay of the chirps and chirped pulse compression in a high-gain seeded free-electron laser
International Nuclear Information System (INIS)
In a seeded high-gain free-electron laser (FEL), where a coherent laser pulse interacts with an ultrarelativistic electron beam, the seed laser pulse can be frequency chirped, and the electron beam can be energy chirped. Besides these two chirps, the FEL interaction introduces an intrinsic frequency chirp in the FEL even if the above-mentioned two chirps are absent. We examine the interplay of these three chirps. The problem is formulated as an initial value problem and solved via a Green function approach. Besides the chirp evolution, we also give analytical expressions for the pulse duration and bandwidth of the FEL, which remains fully longitudinally coherent in the high-gain exponential growth regime. Because the chirps are normally introduced for a final compression of the FEL pulse, some conceptual issues are discussed. We show that to get a short pulse duration, an energy chirp in the electron beam is important.
2007-03-01
Interfacial area transport equation: model development and benchmark experiments
Energy Technology Data Exchange (ETDEWEB)
The interfacial area transport equation dynamically models two-phase flow regime transitions and predicts continuous changes of the interfacial area concentration along the flow field. It replaces the flow regime-dependent correlations for the interfacial area concentration in thermal-hydraulic system analysis. In the present study, detailed formulation of the interfacial area transport equation is presented along with its evaluation results based on the detailed benchmark experiments. In view of model evaluation, the equation is simplified into one-dimensional steady state one-group interfacial area transport equation. The prediction made by model agrees well with the experimental data obtained in round pipes of various diameters. The framework for the two-group transport equation and the necessary constitutive relations are also presented in view of bubble transport of various sizes and shapes. (author)
2002-07-01
Energy Technology Data Exchange (ETDEWEB)
The objective of the inspection qualification is to ensure that applied non-destructive methods (NDT) have the required performance. The approach of the qualification process is systematic and carefully documented and therefore some new requirements can be seen concerning the composition of the documentation. There are also new document types, that only application of the inspection qualification requires. The most important of these is the technical justification, that includes the documented evidences concerning the performance of the inspection system. This publication includes two reports: 'Compilation of the inspection procedure' and 'Essential/influential parameters in NDT qualification'. The former of these discusses the issues to be considered in an inspection procedure especially from the point of view of the mechanised ultrasonic testing. The later report explains the parameters formulated to analyse in the technical ...
2000-06-01
Energy Technology Data Exchange (ETDEWEB)
By analogy with the concepts of human learning, we show and introduce a new method to obtain least product cost and price that includes the effect of innovation and technological learning in manufacturing and production. This key result is a new paradigm instead of the usual economic 'power law' formulation. The new analysis is based on extensive analysis of many technological systems, and is directly related to the presence of learning as experience is accumulated. The results agree with the observed data. By using a consistent basis, the method replaces previous empirical 'power law' descriptions of the technological learning curve with a new 'marginal minimum cost equation' (MCE). (author)
2004-07-01
Energy Technology Data Exchange (ETDEWEB)
To make the Dutch energy system more sustainable as formulated in the objectives of the recently constituted Task Force Energietransitie (Energy Transition), additional investments by the government in sustainable energy are needed. One of the ideas is to start a public-private risk bearing fund that invests in Netherlands based innovation projects in the area of sustainable energy. The ingoing assumption is that there is a shortage of capital supply for innovation projects that are in between the Research and Development phase and the market introduction phase, and that the government can attract further commercial private capital by co-investing itself. The Ministry of Economic Affairs has asked Bain and Company to perform a due diligence on the validity of the in-going assumptions for raising such a Venture Capital fund. This report contains the key conclusions of the study performed in June and the first half of July of 2006.
2006-07-15
British Library Electronic Table of Contents (United Kingdom)
Regional Ocean Modeling System (ROMS v 3.0), a three-dimensional numerical ocean model, was previously enhanced for shallow water applications by including wave-induced radiation stress forcing provided through coupling to wave propagation models (SWAN, REF/DIF). This enhancement made it suitable for surf zone applications as demonstrated using examples of obliquely incident waves on a planar beach and rip current formation in longshore bar trough morphology (Haas and Warner, 2009). In this contribution, we present an update to the coupled model which implements a wave roller model and also a modified method of the radiation stress term based on Mellor (2008, 2011a,b,in press) that includes a vertical distribution which better simulates non-conservative (i.e., wave breaking) processes and ...
2011-01-01
British Library Electronic Table of Contents (United Kingdom)
In this paper I argue that when a researcher is a research instrument, it is likely that the researcher would develop a heightened awareness of his/her own cultural conditioning, especially in the case of cross-cultural studies. And that such awareness would make him/her realise that one's own cultural background may indeed have an influence on formulating his/her research methodology. The paper is based on my own research project on development cooperation between Japan and Cambodia, whereby I examined the perceptions of Cambodians and Japanese on what an appropriate power relationship between donors and recipients should be. At the outset of my research project, I paid little attention to my own cultural condition and the role it might play in my study, though I was aware that being Japa...
2011-01-01
Heat-transfer augmentation in rod bundles near grid spacers
International Nuclear Information System (INIS)
Heat-transfer augmentation by straight grid spacers in rod bundles is studied for single-phase flow and for post-critical heat flux dispersed flow. The heat transfer effect of swirling grid spacers in single-phase flow is also examined. Governing heat-transfer mechanisms are analyzed, and predictive formulations are established. For single-phase flow, the local heat transfer at a straight spacer and at its upstream or downstream locations are treated separately. The effect of local velocity increasing near swirling spacer is considered. For post critical heat flux (CHF) dispersed flow, the heat transfer by thermal radiation, fin cooling, and vapor convection near the spacer are calculated. The predictions are compared with experimental data with satisfactory agreement.
1982-01-01
Gravitational Lens Modeling with Genetic Algorithms and Particle Swarm Optimizers
Strong gravitational lensing of an extended object is described by a mapping from source to image coordinates that is nonlinear and cannot generally be inverted analytically. Determining the structure of the source intensity distribution also requires a description of the blurring effect due to a point spread function. This initial study uses an iterative gravitational lens modeling scheme based on the semilinear method to determine the linear parameters (source intensity profile) of a strongly lensed system. Our 'matrix-free' approach avoids construction of the lens and blurring operators while retaining the least squares formulation of the problem. The parameters of an analytical lens model are found through nonlinear optimization by an advanced genetic algorithm (GA) and particle swarm optimizer (PSO). These global optimization routines are designed to explore the parameter space thoroughly, mapping model degeneracies in detail. We develop a novel method that ...
2011-01-01
Geometric configuration factors for polygonal zones using Nusselt's unit sphere
Energy Technology Data Exchange (ETDEWEB)
The Energy Laboratory of the University of Houston has developed a computer simulation program called CREAM (Cavity Radiation Exchange Analysis Model) for application to the solar central receiver system. CREAM contains a geometric configuration factor generator based on Nusselt's method. A formulation of Nusselt's method provides the basis for a FORTRAN subroutine NUSSELT. Numerical results from NUSSELT are compared to analytic values and values from Sparrow's method. Sparrow's method is based on a double contour integral and its reduction to a single integral which is a approximated by Gaussian methods. Nusselt's method is adequate for the intended engineering applications, but Sparrow's method is an order of magnitude more efficient in many situations.
1983-05-01
Friction in ultra-thin conjunction of valve seals of pressurised metered dose inhalers
British Library Electronic Table of Contents (United Kingdom)
In many drug dispensing devices, such as syringes and inhalers, an elatomeric gasket is used to prevent the formulation from leaking from the chamber. During device actuation, the seal is subjected to friction, which in turn causes its deformation and can cause unintentional leakage, thus dose variability. Additionally, friction of seal is responsible for a host of potential problems such undue effort required for actuation and potential wear. The mechanism of friction generation in the seal conjunction is complex, arising from adhesion of rubber in contact with the moving interface, viscous action of a thin film of fluid and deformation of seal asperities. Therefore, the first step in understanding the conjunctional behaviour of rubber seals is a fundamental study of mechanisms of frictio...
2010-01-01
Fragranced consumer products: Chemicals emitted, ingredients unlisted
British Library Electronic Table of Contents (United Kingdom)
Fragranced consumer products are pervasive in society. Relatively little is known about the composition of these products, due to lack of prior study, complexity of formulations, and limitations and protections on ingredient disclosure in the U.S. We investigated volatile organic compounds (VOCs) emitted from 25 common fragranced consumer products-laundry products, personal care products, cleaning supplies, and air fresheners-using headspace analysis with gas chromatography/mass spectrometry (GC/MS). Our analysis found 133 different VOCs emitted from the 25 products, with an average of 17 VOCs per product. Of these 133 VOCs, 24 are classified as toxic or hazardous under U.S. federal laws, and each product emitted at least one of these compounds. For ''green'' products, emissions of these c...
2011-01-01
International Nuclear Information System (INIS)
There are many differences between industrial CT and industrial radiography, such as imaging principle, inspection time, radiation dose and the requirements for operators etc. The national standards for radiation protection of industrial detection are not applicable to the requirements of protection and safety for #gamma#-ray industrial CT to some extent now. In order to standardize the production and use for #gamma#-ray industrial CT, protect the safety of operators and the public, and to promote the popularization and application of #gamma#-ray industrial CT, it is significant to establish the national standards for radiation protection of #gamma#-ray industrial CT as soon as possible. The purpose of this paper is to introduce the contents of this standard, and specify some important terms. Then there is a brief discussion on the existing problems during establishing such standards. At last, the paper summarize the practice of the standards passed over the past one year, which ...
2009-03-01
Fluidelastic instability of heat exchanger tube bundles; Review and design recommendations
Energy Technology Data Exchange (ETDEWEB)
This paper reports that fluidelastic instability is the most important vibration excitation mechanism for heat exchanger tube bundles subjected to cross-flow. Most of the available data on this topic have been reviewed from the perspective of the designer. Uniform definitions of critical flow velocity for instability, damping, natural frequency and hydrodynamic mass were used. Nearly 300 data points were assembled. The authors found that only data from experiments where all tubes are free to vibrate are valid form a design point of view. In liquids, fluid damping is important and should be considered in the formulation of fluidelastic instability. From a practical design point of view, we conclude that fluidelastic instability may be expressed simply in term of dimensionless flow velocity and dimensionless mass-damping. There is no advantage in considering more sophisticated models at this time. Practical design guidelines are discussed.
1991-05-01
Fixation of high-level wastes in glasses
Energy Technology Data Exchange (ETDEWEB)
A plant for the fixation of high-level wastes in borosilicate glass has been operating in France since 1978. A large plant is under construction in the U.S. for the fixation of defence high-level waste and plans for other glass fixation plants are well advanced at several sites around the world. Among the reasons for the selection of borosilicate glass as a fixation medium are the relative ease of processing wastes of variable composition by means of well established technology, and the long-term radiation and thermal stability of the glass. Well formulated glass also has sufficient resistance to the action of groundwater so that it can serve as an important barrier against the spread of radionuclides via groundwater in any forseeable situation. Research is continuing to quantify the reactions of waste glass in site-specific geological repository environments.
1986-07-30
Five Special Types of Orbits Around Mars
The abstract is additional with repect to the paper published in JGCD. Ordinary Earth satellites are usually placed into five categories of special orbits: sun-synchronous orbits, orbits at the critical inclination, frozen orbits, repeating ground track orbits, and geostationary orbits. This paper investigates their counterparts around Mars and examines the basic nature of these orbits, which are of special interest for missions conducted around Mars, including Mars reconnaissance. Mars' gravity field is much more complicated, with relatively smaller J2, compared to Earth's, which makes the behaviors of these Martian orbits different from those of Earth. Analytical formulations and numerical simulations are used to analyze these Martian orbits and compare them with their Earth counterparts. First, mean element theory is employed to describe variations of orbital elements and give the constraint conditions for achieving these special orbits. Then, numerical ...
2011-01-01
Fermion-fermion and boson-boson amplitudes: surprising similarities
Amplitudes for fermion-fermion, boson-boson and fermion-boson interactions are calculated in the second order of perturbation theory in the Lobachevsky space. An essential ingredient of the model is the Weinberg's 2(2j+1)-component formalism for describing a particle of spin j. The boson-boson amplitude is then compared with the two-fermion amplitude obtained long ago by Skachkov on the basis of the Hamiltonian formulation of quantum field theory on the mass hyperboloid, p_0^2 - p^2=M^2, proposed by Kadyshevsky. The parametrization of the amplitudes by means of the momentum transfer in the Lobachevsky space leads to same spin structures in the expressions of T-matrices for the fermion case and the boson case. However, certain differences are found. Possible physical applications are discussed.
2007-01-01
Explicit Randomness is not Necessary when Modeling Probabilistic Encryption
Although good encryption functions are probabilistic, most symbolic models do not capture this aspect explicitly. A typical solution, recently used to prove the soundness of such models with respect to computational ones, is to explicitly represent the dependency of ciphertexts on random coins as labels. In order to make these label-based models useful, it seems natural to try to extend the underlying decision procedures and the implementation of existing tools. In this paper we put forth a more practical alternative based on the following soundness theorem. We prove that for a large class of security properties (that includes rather standard formulations for secrecy and authenticity properties), security of protocols in the simpler model implies security in the label-based model. Combined with the soundness result of (\\textbf{?}) our theorem enables the translation of security results in unlabeled symbolic models to computational security.
2006-01-01
Evolving Attachment Theory: Beyond Bowlby and Back to Darwin
British Library Electronic Table of Contents (United Kingdom)
Abstract- In our reply to M. H. van IJzendoorn and M. J. Bakermans-Kranenburg (this issue) and R. A. Thompson (this issue), we highlight 2 challenges that attachment researchers face today: (a) closing the gap between the developmental and social psychological traditions and (b) connecting attachment theory to the broader field of evolutionary psychology. We contend that an evolutionary life history approach can contribute to both goals and argue that attachment researchers should consider moving beyond some of Bowlby's original formulations in order to permit further advancement of the field. Finally, we review van IJzendoorn and Bakermans-Kranenburg's criticism of the hypothesis that sex differences in attachment arise in middle childhood; we conclude that the claim that the hypothesis h...
2010-01-01
Erosion below submarine structures
Energy Technology Data Exchange (ETDEWEB)
A numerical model for the development of bed dominated scour around sub-sea structures is presented. The hydrodynamic part of the model is based on a modified potential flow theory. The purpose of the present study has been to develop relatively simple models, yet complex enough to capture the main physics that can be used as engineering tools. An overview of scour phenomena and the basic problems of scour in steady current flow is presented. A hydrodynamic model for horseshoe vortex is presented, as well as a model for the bed transport, and examples are given. The scour in oscillatory flow and a curvilinear model for suspended sediment calculations are described. An advection-diffusion model (formulated in a curvilinear stretched coordinate system) has been developed and is described in an article which has been submitted for publication, a copy of the article is enclosed in Appendix E of the report. (EG)
1997-07-01
Entropy and Hausdorff Dimension in Random Growing Trees
We investigate the limiting behavior of random tree growth in preferential attachment models. The tree stems from a root, and we add vertices to the system one-by-one at random, according to a rule which depends on the degree distribution of the already existing tree. The so-called weight function, in terms of which the rule of attachment is formulated, is such that each vertex in the tree can have at most K children. We define the concept of a certain random measure mu on the leaves of the limiting tree, which captures a global property of the tree growth in a natural way. We prove that the Hausdorff and the packing dimension of this limiting measure is equal and constant with probability one. Moreover, the local dimension of mu equals the Hausdorff dimension at mu-almost every point. We give an explicit formula for the dimension, given the rule of attachment.
2010-01-01
British Library Electronic Table of Contents (United Kingdom)
This paper explores the through-/in-plane characteristics of water transport in the cathode gas diffusion layer (GDL) of a polymer electrolyte fuel cell (PEFC). Theoretical analysis is performed on the non-isothermal two-phase flow under flow channels. A dimensionless group Da (Damkohler number for PEFC operation), defined as the ratio of water generation rate to water vapor-phase removal rate, is formulated to characterize the flow regimes in a PEFC. This group, lumping geometrical parameters and physical properties, compares the water vapor-phase removal capability (via water diffusion and holding capacity) with the rate of water production by the oxygen reduction reaction. We find that this dimensionless group can be used to characterize the non-isothermal, two-phase phenomena: when Da&...
2011-01-01
Elastodynamics of vehicles and crash simulation
Energy Technology Data Exchange (ETDEWEB)
Accidents of free-rolling cars against walls with friction are special cases of the general problem of the dynamic behavior (elastic or plastic) of car motion. Using particle modeling of the car body it is shown that large rotations, contact friction and plastic deformations can be computed. Because of the limitations of FEM it is necessary to model the car as a system of mass points connected by central force systems which are non-linear. The wall is formulated as a rigid body producing constraints for the contacting particles, while the contact force is given by the defined force system. Every contacting particle produces a plastic impact on the wall. The friction force is proportional to the contact force and lies in the direction of the sliding velocity on the wall. Time integration is carried out using a second order Gear method. ((orig.))
1994-09-30
Effects of surfaces and leachables on the stability of biopharmaceuticals
British Library Electronic Table of Contents (United Kingdom)
Abstract Therapeutic proteins are exposed to various potential contact surfaces, particles, and leachables during manufacturing, shipping, storage, and delivery. In this review, we present published examples of interfacial- or leachable-induced aggregation or particle formation, and discuss the mitigation strategies that were successfully utilized. Adsorption to interfaces or interactions with leachables and/or particles in some cases has been reported to cause protein aggregation or particle formation. Identification of the cause(s) of particle formation involving minute amounts of protein over extended periods of time can be challenging. Various formulation strategies such as addition of a nonionic surfactant (e.g., polysorbate) have been demonstrated to effectively mitigate adsorption-i...
2011-01-01
Effective medium theory of the one-dimensional resonance phononic crystal
International Nuclear Information System (INIS)
A general theoretical scheme to describe the effective modulus and mass density for acoustic metamaterials is presented. For such a purpose, an effective medium theory of a one-dimensional acoustic waveguide containing subwavelength-sized Helmholtz resonators is formulated. It is shown that, when the wavelength is much larger than the periodic length and the size of the resonators, the whole composite structure can be treated as an effective homogeneous medium in accounting for its acoustic properties. It is also shown that the acoustic characteristics, such as the effective modulus and the effective mass density, can be determined precisely from the transmission and the reflection data. The calculated effective modulus and effective mass density confirm that this structure behaves as a homogeneous metamaterial with a negative effective modulus in a frequency range just above the resonant frequency.
2008-02-06
A new mathematical framework is formulated to derive the effective equations of motion for the constrained quantum system which possesses an internal clock. In the realm close to classical behavior, the quantum evolution is approximated by a finite system of coupled but ordinary differential equations adhered to the weakly imposed Hamiltonian constraint. For the simplified version of loop quantum cosmology in the Bianchi I model with a free massless scalar filed, the resulting effective equations of motion affirm the bouncing scenario predicted by the previous studies: The big bang singularity is resolved and replaced by the big bounces, which take place up to three times, once in each diagonal direction, whenever the directional density approaches the critical value in the regime of Planckian density. It is also revealed that back-reaction arises from the quantum corrections and modifies the precise value of the directional density at the bouncing epoch. ...
2008-01-01
Effect of Nisin?s Controlled Release on Microbial Growth as Modeled for Micrococcus luteus
British Library Electronic Table of Contents (United Kingdom)
The need for safe food products has motivated food scientists and industry to find novel technologies for antimicrobial delivery for improving food safety and quality. Controlled release packaging is a novel technology that uses the package to deliver antimicrobials in a controlled manner and sustain antimicrobial stress on the targeted microorganism over the required shelf life. This work studied the effect of controlled release of nisin to inhibit growth of Micrococcus luteus (a model microorganism) using a computerized syringe pump system to mimic the release of nisin from packaging films which was characterized by an initially fast rate and a slower rate as time progressed. The results show that controlled release of nisin was strikingly more effective than instantly added (?formulated...
2011-01-01
Dynamics of business games with management of fuzzy rules for decision making
British Library Electronic Table of Contents (United Kingdom)
Effective and efficient strategic decision making is the backbone for the success of a business organization. These decision making processes, used among its competitors in a particular industry, determine whether the business will continue to survive or not. In this research, fuzzy logic (FL) concept and game theory are being used to model strategic decision making processes by business organizations. Competition between business organizations is viewed as a game with each business organization as a player. A player formulates his own decisions by making his strategic moves based on uncertain information. This is the information he has about the opponents with respect to prevailing or anticipated market demand, cost of production, marketing, consolidation efforts and some other business v...
2010-01-01
Drift- or Fluctuation-Induced Ordering and Self-Organization in Driven Many-Particle Systems
According to empirical observations, some pattern formation phenomena in driven many-particle systems are more pronounced in the presence of a certain noise level. We investigate this phenomenon of fluctuation-driven ordering with a cellular automaton model of interactive motion in space and find an optimal noise strength, while order breaks down at high(er) fluctuation levels. Additionally, we discuss the phenomenon of noise- and drift-induced self-organization in systems that would show disorder in the absence of fluctuations. In the future, related studies may have applications to the control of many-particle systems such as the efficient separation of particles. The rather general formulation of our model in the spirit of game theory may allow to shed some light on several different kinds of noise-induced ordering phenomena observed in physical, chemical, biological, and socio-economic systems (e.g., attractive and repulsive agglomeration, or segregation).
2002-01-01
Disruptive core relocation analysis of PHEBUS/FPT0 test with SAMPSON code
International Nuclear Information System (INIS)
SAMPSON is an integration of twelve analysis modules under the final development phase (phase-2) and will be capable of simulating hypothesized severe accidents in a nuclear power plant. One of these modules, the Molten Core Relocation Analysis (MCRA) module, simulates the relocation behavior of a molten core during a severe accident. MCRA models severe accident phenomena by using mechanistic formulations for multi-phase, multi-component, and multi-velocity field. As one of the verification studies of SAMPSON in Phase-1, the in-core phenomena of PHEBUS/FPT0 was analyzed with three modules, MCRA, fuel rod heat up analysis (FRHA) module, and the analysis control module (ACM) of SAMPSON. (author)
2000-10-01
Development of a pelleted waste form for high-level alumina wastes
Energy Technology Data Exchange (ETDEWEB)
A formulation to pelletize simulated high-level ICPP alumina waste calcine was developed. The pellets are formed on a 41-cm-diameter disc pelletizer using 5% bentonite, 2% metakaolin, and 5 wt % calcium hydroxide as a solid binder and a solution of 7M phosphoric acid and 4M nitric acid as a liquid binder. After drying and heat treatment at 800/sup 0/C for 2 hours, the average crush strength of the pellets is 3.9 MPa and the pellets have a leach resistance of 10/sup -3/ g/cm/sup 2//day, based on Soxhlet leaching for 48 h at 95/sup 0/C with distilled water.
1980-09-01
Development of a Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System
British Library Electronic Table of Contents (United Kingdom)
Understanding the processes responsible for coastal change is important for managing our coastal resources, both natural and economic. The current scientific understanding of coastal sediment transport and geology suggests that examining coastal processes at regional scales can lead to significant insight into how the coastal zone evolves. To better identify the significant processes affecting our coastlines and how those processes create coastal change we developed a Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System, which is comprised of the Model Coupling Toolkit to exchange data fields between the ocean model ROMS, the atmosphere model WRF, the wave model SWAN, and the sediment capabilities of the Community Sediment Transport Model. This formulation builds upon ...
2010-01-01
Development and analysis of stage-damage curves for the Kum River basin
Energy Technology Data Exchange (ETDEWEB)
In the flood surveys, it is fundamental to set up the relations of stage-damage. And this makes it possible to evaluate the flood regulation effects of the multipurpose dam and/or levee construction for optimum formulation. Unfortunately in the previous basin studies excluding the Han river basin survey, the conventional approaches on this matter have not been performed due to its time-consuming complexity. In this study we attempted a new method based on the disaster status, and constructed six stage-damage curves along the reaches of the Kum river basin, based upon the flood events records for recent 12 years (1981-92). (author). 12 refs., 3 tabs., 13 figs.
1996-10-31
The effect of high lift airfoils on the cost effectiveness of HAWT and VAWT (horizontal and vertical axis wind turbine) machines is studied. The scope involved first studying modern two dimensional airfoils, and developing a generalized formulation for their performance in terms of lift, drag, and thickness at appropriate Reynolds numbers. Single element, multi-element, symmetrical, extra thick airfoils and jet flap airfoils were analyzed. The jet flap airfoils were considered to be unacceptable because of excessive power requirements. Then the effect of using the above airfoils on the rotors of a variety of wind turbines was made. Qualitative representation of the type of airfoils studied is given.
1979-05-01
Energy Technology Data Exchange (ETDEWEB)
This paper presents a new method for simultaneously selecting the power system stabilizer (PSS) parameters in multimachine power systems. Design of local output feedback power system stabilizer using local signal of the generator (e.g. speed or power) is formulated as a decentralized modal control (DMC) problem. Exact model reduction based on modal control theory is proposed to make the determination of PSS parameters highly efficient. Results obtained from the coordinated tuning of the parameters of three power system stabilizers equipped on a multimachine power system show that exact assignment of the eigenvalues associated with the poorly damped electromechanical modes can be achieved in a very efficient manner.
1986-01-01
Control area performance improvement by extended security constrained economic dispatch
Energy Technology Data Exchange (ETDEWEB)
An algorithm for solving the extended security constrained economic dispatch (ESCED) problem with real-time economic dispatch grade speed and reliability is presented. The ESCED problem is formulated by adding regulating margin and ramp rate constraints to the network security constrained economic dispatch problem previously solved by the CEDC algorithm. Starting with Newton`s method to optimize the Lagrangian, the ESCED is developed by superimposing on Newton`s method eight major components called Tracking Start Initialization, Hessian Pre-Elimination, Implicit Dual Variable Calculations, Regulating Margin Sensitivity Coefficient Calculations, Traumatic Event Evaluation, Constraint Relaxation, Implicit Ramp Rate Constraint Implementation, and Relaxed Incremental Cost Calculations. Test results are also presented.
1997-02-01
British Library Electronic Table of Contents (United Kingdom)
Abstract A 3-month, open-label, single-center study was conducted to determine whether a uniquely formulated and physiologically balanced topical treatment serum containing multiple growth factors, cytokines, peptides, antioxidants and depigmenting agents could improve the visible signs of facial photodamage. Thirty-seven females, aged 32-55 years, with mild to severe, fine and coarse peri-ocular wrinkles were enrolled and completed the study. Subjects applied the treatment serum to the face twice daily for 3 months in conjunction with a basic skincare regimen. Clinical evaluations of photodamage were performed at baseline and months 1, 2 and 3. Cutometer measurements and subject self-assessment questionnaires were also conducted during the study. Clinical evaluations showed statistically ...
2010-01-01
Changes in regulatory theory: Market-based pricing
Energy Technology Data Exchange (ETDEWEB)
With the introduction of competition and diversification into retail utility services, rate-making methods are being rethought. Rates that are strictly cost-based may be too slow in responding to changes within the utility industry. And the advent of independent power production as a significant source of energy calls for greater flexibility in pricing of wholesale utility services as well. Various deregulation or reregulation plans have been formulated, including both price cap and price floor proposals. Some regulatory authorities have embraced market-based pricing over cost-based methods as the best solution to pricing problems. This article addresses Federal Energy Regulatory Commission response to market-based rates.
1990-11-08
Caburization kinetics of alloy-800 in liquid sodium at 550_0C
International Nuclear Information System (INIS)
Preliminary observations on the isothermal carbon transfer in low-carbon Alloy-800 exposed in sodium with AISI-304 type of steel at 550_0 are reported. The alloy was found to undergo a carburization comparable or slightly lower than that observed for the AISI-304 stainless steel for carbon activities above 6 x 10 /sup -3/ at 550_0C, but was not found to decarburize below such a carbon activity value. In the examined range the chemical composition of the alloys does not affect the process out of the experimental uncertainty of measure. Conclusions concerning the effective diffusion for carbon in the alloy are formulated. Preliminary relationships were found for an empirical evaluation of the carburization of the Alloy-800 in sodium of known carbon activity.
Burnup analysis and in-core fuel management study of the 3MW TRIGA MARK II research reactor
British Library Electronic Table of Contents (United Kingdom)
The principal objective of this study is to formulate an effective optimal fuel management strategy for the TRIGA MARK II research reactor at AERE, Savar. The core management study has been performed by utilizing four basic types of information calculated for the reactor: criticality, power peaking, neutron flux and burnup calculation. This paper presents the results of the burnup calculations for TRIGA LEU fuel elements. The fuel element burnup for approximately 20 years of operation was calculated using the TRIGAP compute code. The calculation is performed in one-dimensional radial geometry in TRIGAP. Inter-comparison of TRIGAP results with other two calculations performed by MVP-BURN and MCNP4C-ORIGEN2.1 show very good agreement. Reshuffling at 20,000MWh step provides the highest core l...
2008-01-01
Buckling and ultimate capability of plates and stiffened panels in axial compression
British Library Electronic Table of Contents (United Kingdom)
This paper presents extensive non-linear finite element (FE) analysis and formulation development work carried out on the ultimate compressive strength of plates and stiffened panels of ship structures. A review of contemporary designs for large ships was carried out. The existing formulae for plate ultimate compressive strength were reviewed and compared with non-linear FE analysis results. A semi-analytical formula for ultimate compressive strength assessments of stiffened panels was proposed and is described. The developed formula was verified against results using ABAQUS non-linear FE software for a series of 61 stiffened panels and a good agreement between the proposed formula and FE results were achieved. The method was verified against a large number of published FE results and was ...
2009-01-01
The Arnowitt-Deser-Misner canonical formulation of general relativity is extended to the covariant brane-world theory in arbitrary dimensions. The exclusive probing of the extra dimensions makes a substantial difference, allowing for the construction of a non-constrained canonical theory. The quantum states of the brane-world geometry are defined by the Tomonaga-Schwinger equation, whose integrability conditions are determined by the classical perturbations of submanifolds contained in the Nash's differentiable embedding theorem. In principle, quantum brane-world theory can be tested by current experiments in astrophysics and by near future laboratory experiments at Tev energy. The implications to the black-hole information loss problem, to the accelerating cosmology, and to a quantum mathematical theory of four-sub manifolds are briefly commented.
2007-01-01
Based on recent work on simplicial diffeomorphisms in colored group field theories, we develop a representation of the colored Boulatov model, in which the GFT fields depend on variables associated to vertices of the associated simplicial complex, as opposed to edges. On top of simplifying the action of diffeomorphisms, the main advantage of this representation is that the GFT Feynman graphs have a different stranded structure, which allows a direct identification of subgraphs associated to bubbles, and their evaluation is simplified drastically. As a first important application of this formulation, we derive new scaling bounds for the regularized amplitudes, organized in terms of the genera of the bubbles, and show how the pseudo-manifolds configurations appearing in the perturbative expansion are suppressed as compared to manifolds. Moreover, these bounds are proved to be optimal.
2011-01-01
Bi-directional causality in California's electricity and natural-gas markets
International Nuclear Information System (INIS)
The Granger instantaneous-causality test is applied to explore the potential causal relationships between wholesale electricity and natural-gas prices in California. The test shows these relationships to be bi-directional, and reveals California's electricity and natural-gas markets to be as inextricably intertwined as casual observation and theoretical considerations would suggest they ought to be. This meshing of markets exacerbated the effects of California's natural-gas crisis on the contemporaneous electricity crisis, while concurrently the electricity crisis may have contributed to the dysfunction in the national-gas market and helped to precipitate the natural-gas crisis. The finding supports an integrated approach, as opposed to a piecemeal approach, for formulating energy policy recommendations, not just in California but in the world at large. (author)
2006-10-01
Bi-directional causality in California's electricity and natural-gas markets
International Nuclear Information System (INIS)
The Granger instantaneous-causality test is applied to explore the potential causal relationships between wholesale electricity and natural-gas prices in California. The test shows these relationships to be bi-directional, and reveals California's electricity and natural-gas markets to be as inextricably intertwined as casual observation and theoretical considerations would suggest they ought to be. This meshing of markets exacerbated the effects of California's natural-gas crisis on the contemporaneous electricity crisis, while concurrently the electricity crisis may have contributed to the dysfunction in the national-gas market and helped to precipitate the natural-gas crisis. The finding supports an integrated approach, as opposed to a piecemeal approach, for formulating energy policy recommendations, not just in California but in the world at large.
2006-10-01
Automated preparation of Re-188 lipiodol for the treatment of hepatocellular carcinoma
Energy Technology Data Exchange (ETDEWEB)
The iodinated oil lipiodol is commonly used as a carrier for in situ delivery of drugs or radioactivity to hepatic tumors. Recently, we reported a new kit formulation for high-activity labeling of lipiodol with the {beta}-emitting radionuclide Re-188. Since the whole preparation involves different steps and complex manipulations of high-activity samples, we describe here an automated synthesis module that allows the easy preparation of sterile and pyrogen-free samples of Re-188 lipiodol ready to be administered to the patient. Important advantages include the possibility to incorporate high Re-188 activity into the lipiodol hydrophobic phase and a sharp reduction of radiation exposure of the operator assisting the labelling procedure. Application of this modular reaction system could be also extended to the preparation of other Re-188 radiopharmaceuticals and to compound labelled with different {beta}-emitting therapeutic radionuclides.
2011-02-15
Energy Technology Data Exchange (ETDEWEB)
This document represents the FY2002 BPA contract Statement of Work for the Yakama Nation (YN) portion of the project entitled 'Assessment of current and potential salmonid production in Rattlesnake Creek associated with restoration efforts'. The purpose of the project is to complete detailed surveys of water quality, fish populations, habitat conditions and riparian health in the Rattlesnake Creek sub-basin of the White Salmon River in south central Washington. Results of the surveys will be used to establish Rattlesnake Creek sub-basin baseline environmental factors prior to anticipated removal of Condit Dam in 2006 and enable cost-effective formulation of future watershed restoration strategies.
2003-05-01
British Library Electronic Table of Contents (United Kingdom)
Summary Topmouth culter (Culter alburnus), a freshwater carnivorous fish of the Cyprinidae, is one of the most popular fish species in aquatic market in China. The anatomy and histology features of fish intestine are very useful for understanding digestive physiology, diagnosing some intestinal diseases and formulating suitable feeds. Thus, here we first characterize topmouth culter intestine via light microscope, transmission electron microscope and scan electron microscope. The -Z- shaped intestine can be divided into three parts (e.g. the anterior intestine, middle intestine and posterior intestine), with an intestinal coefficient of 0.68. The anterior intestine possessed the longest mucosa folds and thickest muscularis among the three intestinal parts, and microvilli were very well-dev...
2011-01-01
Analytic Thermodynamics and Thermometry of Gaudin-Yang Fermi Gases
International Nuclear Information System (INIS)
We study the thermodynamics of a one-dimensional attractive Fermi gas (the Gaudin-Yang model) with spin imbalance. The exact solution has been known from the thermodynamic Bethe ansatz for decades, but it involves an infinite number of coupled nonlinear integral equations whose physics is difficult to extract. Here the solution is analytically reduced to a simple, powerful set of four algebraic equations. The simplified equations become universal and exact in the experimental regime of strong interaction and relatively low temperature. Using the new formulation, we discuss the qualitative features of finite-temperature crossover and make quantitative predictions on the density profiles in traps. We propose a practical two-stage scheme to achieve accurate thermometry for a trapped spin-imbalanced Fermi gas.
2009-10-02
Analysis of installation damage tests for LRFD calibration of reinforced soil structures
British Library Electronic Table of Contents (United Kingdom)
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...
2011-01-01
Analysis of catalyst deactivation during steam reforming of jet fuel on Ni-(PdRh)/g-Al2O3 catalyst
British Library Electronic Table of Contents (United Kingdom)
Catalyst deactivation during steam reforming of transportation fuels, primarily due to sulfur poisoning and carbon deposition, is a major hurdle in the commercialization of fuel cell technologies. In an attempt to better understand the phenomena, a previously formulated multi-component (Ni, Pd, Rh) catalyst supported on g-Al2O3 was studied under steam reforming of Jet A spiked with thiophene to achieve a total sulfur content of 1000ppm by weight. Analysis of fresh catalysts showed the presence of two groups of active metal particles, primarily distinguished by their size and composition; small particles (1-5nm) largely comprised of Rh and large particles (10-20nm) that were predominantly Ni, with or without the presence of Pd. Analysis of used catalysts showed sintering of crystallites con...
2011-01-01
An integer programming approach to support the US Air Forces air mobility network
British Library Electronic Table of Contents (United Kingdom)
The United States Air Forces air mobility command is responsible for creating a schedule and executing that schedule for a large-scale air mobility network that encompasses aircraft with prioritized missions. Aerial ports (airports) can process or park a maximum number of aircraft, called the maximum on ground (MOG). As the schedule changes due to disruptions, such as equipment failure or weather, the MOG constraint can cause the new schedule to be infeasible. Traditionally, re-planning the channel route schedule to adhere to MOG constraints has been a manual process that usually stops after the first feasible set of changes is found, due to the challenges of large amounts of data and urgency for a re-plan. We extend Bertsimas and Stocks integer program formulation for the commercial airli...
2008-01-01
Energy Technology Data Exchange (ETDEWEB)
The solution of the governing steady transport equations for momentum, heat and mass transfer in flowing fluids can be very difficult. These difficulties arise from the nonlinear, coupled, nonsymmetric nature of the system of algebraic equations that results from spatial discretization of the PDEs. In this manuscript the authors focus on evaluating a proposed nonlinear solution method based on an inexact Newton method with backtracking. In this context they use a particular spatial discretization based on a pressure stabilized Petrov-Galerkin finite element formulation of the low Mach number Navier-Stokes equations with heat and mass transport. The discussion considers computational efficiency, robustness and some implementation issues related to the proposed nonlinear solution scheme. Computational results are presented for several challenging CFD benchmark problems as well as two large scale 3D flow simulations.
1997-02-01
Advanced Monitoring and Control of Multi monomer System in Emulsion Polymerization
British Library Electronic Table of Contents (United Kingdom)
Abstract A control framework was developed for real time implementation of optimal control of emulsion polymerization with multiple monomers by integrating model based algorithms with software engines. The developed system was applied for controlling conversion, particle size, molar mass, and polymer composition using model predictive control (MPC) based on mechanistic models for emulsion polymerization. The control formulation was extended to account for existing process constraints on the input, input moves, and solids content. On experimental testing, the developed control scheme was found to achieve the desired objectives without violating the process constraints and showed good robustness in rejecting disturbances. Improvements in the process operation and polymer property control wer...
2010-01-01
A two-component Frenkel-Kontorowa model for surface alloy formation
Energy Technology Data Exchange (ETDEWEB)
It has been shown by recent experiments that bulk immiscible metals (e.g. Ag/Cu, Ag/Co and Au/Ni) can form binary alloys on certain surfaces where the substrate mediates the elastic misfits between the two components, thus relieving the elastic strain in the overlayer. These novel surface alloys exhibit a rich phase structure. We formulate a two-component Frenkel-Kontorova model in one dimension to study surface alloy formation. This model can naturally incorporate dislocation formation that plays a crucial role in determining the actual structure of the system. Using energy minimization calculations we provide a phase diagram in terms of average alloy composition and the energy of mixing. Monte Carlo simulations were also performed to study the structure and interaction of the emerging dislocations.
2003-04-02
British Library Electronic Table of Contents (United Kingdom)
Abstract Residue trial data reported by the Joint FAO/WHO Meeting on Pesticide Residues (JMPR) have been reviewed to establish whether or not the resulting residues in harvested commodities are proportional to the pesticide application rate used on the crop. Numerous sets of trials were identified where the only parameter varied was application rate or spray concentration. Analysis of this database in terms of application rate, spray concentration, formulation type, preharvest interval, crop, pesticide, residue level and application type confirms that residues scale with application rate (proportionality principle). It is anticipated that use of the proportionality principle by regulators and those interested in evaluating pesticide residue data will improve pesticide risk assessment. Copy...
2011-01-01
A proof of concept study for a structure activity model for the toxicity of nanoparticles
Environmental Research Database
ObjectivesThe development of novel formulations of nanoparticles in the nanotechnology industry and their increasing importance and use in industry means there is certainty of human environmental exposures in both the workplace and the general environment. The pulmonary route of exposure to airborne nanoparticles is a major one, as nanoparticles are handled in industry, escape from workplaces and products containing nanoparticles undergo attrition in the environment. There is a substantial problem for ris [continued...]DescriptionNanoparticles are extremely small particles, each individual particlel being less than one ten millionth of a metre in size. We are exposed to nanoparticles in busy streets as they are present in traffic exhaust produced from combustion of fuel and such nanoparticles are considered to be important in causing the harmful effects associated with exposure to air pollution. There are other situations where nanoparticles are found in the air, ...
2009-01-28
British Library Electronic Table of Contents (United Kingdom)
A one-dimensional, steady-state, two-phase direct methanol fuel cell (DMFC) model is developed to precisely investigate complex physiochemical phenomena inside DMFCs. In this model, two-phase species transport through the porous components of a DMFC is formulated based on Maxwell-Stefan multi-component diffusion equations, while capillary-induced liquid flow in the porous media is described by Darcy's equation. In addition, the model fully accounts for water and methanol crossover through the membrane, which is driven by the effects of electro-osmotic drag, diffusion, and the hydraulic pressure gradient. The developed model is validated against readily available experimental data in the literature. Then, a parametric study is carried out to investigate the effects of the operating temperat...
2010-01-01
A novel volumetric method for quantitation of titanium dioxide in cosmetics
British Library Electronic Table of Contents (United Kingdom)
Nowadays there are many sun-protection cosmetics incorporating organic or inorganic UV filters as active ingredients. Chemically stable inorganic sunscreen agents, usually metal oxides, are widely employed in high-SPF (sun protection factor) products. Titanium dioxide is one of the most frequently used inorganic UV filters. It has been used as a pigment for a long period of cosmetic history. With the development of micronization techniques, it has become possible to incorporate titanium dioxide in sunscreen formulations without the previous whitening effect, and hence its use in cosmetics has become an important research topic. However, there are very few works related to quantitation of titanium dioxide in sunscreen products. In this research, we analysed the amounts of titanium dioxide i...
2007-01-01
A novel medium devoid of ruminant peptone for high yield growth of Mycoplasma ovipneumoniae
British Library Electronic Table of Contents (United Kingdom)
Mycoplasma ovipneumoniae is considered an emerging veterinary pathogen causing pneumonia in sheep and goats worldwide. Currently it has not been possible to define a growth medium that yields the maximum growth of M. ovipneumoniae within a short incubation period. Growth yields of M. ovipneumoniae in Eatons medium are variable and not as consistently high as those seen with other Mycoplasma spp. This study investigated the ability of different M. ovipneumoniae field strains to grow in various media formulations, where PPLO broth was replaced by a vegetable protein source, and comparisons were made in terms of strain viability in Eatons medium. Studies were also conducted to determine the optimal carbohydrate source for use in the M. ovipneumoniae medium. Generally, it was found that differ...
2008-01-01
A novel approach to the dynamics of Szekeres dust models
We obtain an elegant and useful description of the dynamics of Szekeres dust models (in their full generality) by means of "quasi--local" scalar variables constructed by suitable integral distributions that can be interpreted as weighed proper volume averages of the local covariant scalars. In terms of these variables, the field equations and basic physical and geometric quantities are formally identical to their corresponding expressions in the spherically symmetric LTB dust models. Since we can map every Szekeres model to a unique LTB model, rigorous results valid for the latter models can be readily generalized to a non--spherical Szekeres geometry. The new variables lead naturally to an initial value formulation in which all scalars are expressed as scaling laws in terms of their values at an arbitrary initial space slice. These variables also yield a significant simplification of numerical work, since the fluid flow evolution equations become a system of ...
2011-01-01
A common framework for aspect mining based on crosscutting concern sorts
The increasing number of aspect mining techniques proposed in literature calls for a methodological way of comparing and combining them in order to assess, and improve on, their quality. This paper addresses this situation by proposing a common framework based on crosscutting concern sorts which allows for consistent assessment, comparison and combination of aspect mining techniques. The framework identifies a set of requirements that ensure homogeneity in formulating the mining goals, presenting the results and assessing their quality. We demonstrate feasibility of the approach by retrofitting an existing aspect mining technique to the framework, and by using it to design and implement two new mining techniques. We apply the three techniques to a known aspect mining benchmark and show how they can be consistently assessed and combined to increase the quality of the results. The techniques and combinations are implemented in FINT, our publicly available free aspect ...
2006-01-01
A Novel Bid Optimizer for Sponsored Search Auctions based on Cooperative Game Theory
In this paper, we propose a bid optimizer for sponsored keyword search auctions which leads to better retention of advertisers by yielding attractive utilities to the advertisers without decreasing the revenue to the search engine. The bid optimizer is positioned as a key value added tool the search engine provides to the advertisers. The proposed bid optimizer algorithm transforms the reported values of the advertisers for a keyword into a correlated bid profile using many ideas from cooperative game theory. The algorithm is based on a characteristic form game involving the search engine and the advertisers. Ideas from Nash bargaining theory are used in formulating the characteristic form game to provide for a fair share of surplus among the players involved. The algorithm then computes the nucleolus of the characteristic form game since we find that the nucleolus is an apt way of allocating the gains of cooperation among the search engine and the advertisers. The ...
2009-01-01
Virasoro algebra action on integrable hierarchies and Virasoro contraints in matrix models
International Nuclear Information System (INIS)
The action of the Virasoro algebra on integrable hierarchies of non-linear equations and on related objects ('Schroedinger' differential operators) is investigated. The method consists in pushing forward the Virasoro action to the wave function of a hierarchy, and then reconstructing its action on the dressing and Lax operators. This formulation allows one to observe a number of suggestive similarities between the structures involved in the description of the Virasoro algebra on the hierarchies and the structure of conformal field theory on the world-sheet. This includes, in particular, an 'off-shell' hierarchy version of operator products and of the Cauchy kernel. In relation to matrix models, which have been observed to be effectively described by integrable hierarchies subjected to Virasoro constraints, I propose to define general Virasoro-constrained hierarchies also in terms of dressing operators, by certain equations which carry the information of the ...
1991-12-01
Revisit to the helicity and the generalized self-organization theory
Energy Technology Data Exchange (ETDEWEB)
It is clarified that the so-caned 'helicity conservation law' is never the conservation equation of the helicity K itself', but is merely 'the time change rate equation of K', which is passively and resultantly determined by the mutually independent volume and surface integral terms. It is shown that since the total helicity K can never be conserved in the real experimental systems, the conjecture of the total helicity invariance is not physically available to real magnetized plasmas in an exact sense. The well-known relaxation theory by Dr. J. B. Taylor is clarified to be neither the variational principle nor the energy principle, but be merely a mathematical calculation, using the variational calculus in order to find the minimum magnetic energy solution from the set of solutions having the same value of K. With the use of auto-correlations for physical quantities, it is presented that a novel basic formulation of an ...
2000-09-01
Rethinking maternal-fetal conflict: gender and equality in perinatal ethics.
Practitioners who care for pregnant women face dilemmas when their patients use illicit drugs, reject medical recommendations, or cause fetal harm. Many ethics scholars characterize those situations as maternal-fetal conflicts. In conflict-based models, maternal rights are considered to conflict with fetal rights, or moral obligations owed to pregnant women are considered to conflict with those owed to their fetuses. I offer an alternative model of pregnancy ethics by applying relational and equality-based moral theories to situations of fetal harm by pregnant women. In this model, clinicians faced with ethical dilemmas should attempt to understand pregnant women and their decisions within their broad social networks and communities, ask how the clinician's personal standpoint influences outcomes judged to be ethical, and determine whether the clinician's ethical formulations reduce or enhance existing gender, class, or racial inequality. This model focuses on the ...
2000-11-01
Wood Plastic Composites (WPCs) have experienced a healthy growth during the last decade. However, improvement in properties is necessary to increase their utility for structural applications. The toughness of WPCs can be improved by creating a fine cellular structure while reducing the density. Extrusion processing is one of the most economical methods for profile formation. For our study, rectangular profiles were extruded using a twin-screw extrusion system with different grades of HDPE and with varying wood fibre and lubricant contents together with maleated polyethylene (MAPE) coupling agent to investigate their effects on WPC processing and mechanical properties. Work has been done to redesign the extrusion system setup to achieve smoother and stronger profiles. A guiding shaper, submerged in the water, has been designed to guide the material directly through water immediately after exiting the die; instead of passing it through a water cooled vacuum calibrator and then through ...
2010-01-01
Optimization of amide-based inhibitors of soluble epoxide hydrolase with improved water solubility.
Soluble epoxide hydrolase (sEH) plays an important role in the metabolism of endogenous chemical mediators involved in the regulation of blood pressure and inflammation. 1,3-Disubstituted ureas with a polar group located on the fifth atom from the carbonyl group of urea function are active inhibitors of sEH both in vitro and in vivo. However, their limited solubility in water and relatively high melting point lead to difficulties in formulating the compounds and poor in vivo efficacy. To improve these physical properties, the effect of structural modification of the urea pharmacophore on the inhibition potencies, water solubilities, octanol/water partition coefficients (log P), and melting points of a series of compounds was evaluated. For murine sEH, no loss of inhibition potency was observed when the urea pharmacophore was modified to an amide function, while for human sEH 2.5-fold decreased inhibition was obtained in the amide compounds. In addition, a NH group ...
2005-05-19
On foundation of the generalized Nambu mechanics
International Nuclear Information System (INIS)
We outline basic principles of a canonical formalism for the Nambu mechanics - a generalization of Hamiltonian mechanics proposed by Yoichiro Nambu in 1973. It is based on the notion of a Nambu bracket, which generalizes the Poisson bracket - a 'binary'' operation on classical observables on the phase space - to the 'multiple' operation of higher order n#>=#3. Nambu dynamics is described by the phase flow given by Nambu-Hamilton equations of motion - a system of ODE's which involves n-1 'Hamiltonians'. We introduce the fundamental identity for the Nambu bracket - a generalization of the Jacobi identity - as a consistency condition for the dynamics. We show that Nambu bracket structure defines a hierarchy of infinite families of 'subordinated' structures of lower order, including Poisson bracket structure, which satisfy certain matching conditions. The notion of Nambu bracket enables us to define Nambu-Poisson manifolds - phase spaces for the Nambu mechanics, which turn out to be ...
Meson self-energies calculated by the relativistic particle-hole-antiparticle representation
International Nuclear Information System (INIS)
A new formulation of meson self-energies is introduced for #sigma#,#omega#,#pi#,#rho#,#delta#, and #eta# mesons on the basis of the particle-hole-antiparticle representation. We have studied the difference between the meson self-energy (MSE) of this representation and the MSE of the traditional density-Feynman (DF) representation. It is shown that the new formulation describes exactly the physical processes such as particle-hole excitations or particle-antiparticle excitations, and that, on the other hand, the meson self-energy based on the DF representation includes unphysical components. By numerical calculations, the meson self-energies describing the particle-hole excitations are shown to be close to each other for most of the meson self-energy in low momentum (R<500 MeV) and low energy (R_0<200 MeV). This fact implies that former calculations using the low momentum and low-energy part do not change greatly. The density part of the ...
The ability to mechanically reinforce an osteoporotic vertebral body could impede spinal compression fracture and the associated pain and complications. Previous studies have shown that reinforcement of fractured vertebrae with conventional acrylic cement can relieve symptoms and avoid further collapse. In this study, we explored the use of a carbonated apatite cement combined with a minimally invasive injection technique to improve the compressive mechanical properties of cadaveric vertebral bodies. After establishing the biomechanical characteristics of cement formulations intended to have appropriate viscosities, we evaluated the infiltration of the cements into thoracic vertebral bodies using a combined suction-injection technique. The energy-absorption capabilities of the reinforced vertebral bodies were then measured during axial compressive tests and compared with those of nonreinforced vertebrae. The ultimate compressive strength of the cement ...
1999-01-01
The lipid fractions of residues from historical pharmaceutical ointments were analysed by reversed-phase liquid chromatography coupled with atmospheric pressure chemical ionization and mass spectrometer detection. The residues were contained in a series of historical apothecary jars, dating from the eighteenth century and conserved at the "Aboca Museum" in Sansepolcro (Arezzo, Italy) and at the pharmacy of the "Real Cartuja de Valldemossa" in Palma de Majorca (Spain). The analytical protocol was set up using a comparative study based on the evaluation of triacylglycerol (TAG) compositions in raw natural lipid materials and in laboratory-reproduced ointments. These ointments were prepared following pharmaceutical recipes reported in historical treatises and used as reference materials. The reference materials were also subjected to stress treatments in order to evaluate the modification occurring in the TAG profiles as an effect of ageing. TAGs were successfully detected in the ...
2011-06-29
Evaluation of a novel radiopacifiying agent on the physical properties of surgical spineplex.
Polymethlylmethacrylate (PMMA) is the most frequently used cement for percutaneous vertebroplasty and kyphoplasty. To aid visualisation during surgery cements are doped with radiopacifying agents such as Barium sulphate (Ba(2)SO(4)) or Zirconium Dioxide (ZiO(2)). Mounting research suggests that these agents may impair the biocompatibility of the cements. However, incorporating an alternative radiopacifier agent with excellent biocompatibility would be a significant step forward. Bioactive radiopaque glasses incorporating elements such as strontium (Sr) and zinc (Zn), known to have beneficial and therapeutic effects on bone, are of great interest in this respect. In this study, the Ba(2)SO(4) of the commercially available Spineplex was incrementally replaced with a radiopaque therapeutic glass composition. The resulting effects on cement setting time, peak isotherm, ultimate compressive strength, Young's modulus (up to 30 days cement maturation) and radiopacity were evaluated. The ...
2009-08-18
Benchmarks and models for 1-D radiation transport in stochastic participating media
Energy Technology Data Exchange (ETDEWEB)
Benchmark calculations for radiation transport coupled to a material temperature equation in a 1-D slab and 1-D spherical geometry binary random media are presented. The mixing statistics are taken to be homogeneous Markov statistics in the 1-D slab but only approximately Markov statistics in the 1-D sphere. The material chunk sizes are described by Poisson distribution functions. The material opacities are first taken to be constant and then allowed to vary as a strong function of material temperature. Benchmark values and variances for time evolution of the ensemble average of material temperature energy density and radiation transmission are computed via a Monte Carlo type method. These benchmarks are used as a basis for comparison with three other approximate methods of solution. One of these approximate methods is simple atomic mix. The second approximate model is an adaptation of what is commonly called the Levermore-Pomraning model and which is referred to here as the standard ...
2000-08-21
Energy Technology Data Exchange (ETDEWEB)
Seven generic types of collectors, together with associated subsystems for electric power generation, were considered. The collectors can be classified into three categories: (1) two-axis tracking (with compound-curvature reflecting surfaces); (2) one-axis tracking (with single-curvature reflecting surfaces); and (3) nontracking (with low-concentration reflecting surfaces). All seven collectors were analyzed in conceptual system configurations with Rankine-cycle engines. In addition, two of the collectors were analyzed with Brayton-cycle engines, and one was analyzed with a Stirling-cycle engine. With these engine options, and the consideration of both thermal and electrical storage for the Brayton-cycle central receiver, 11 systems were formulated for analysis. Conceptual designs developed for the 11 systems were based on common assumptions of available technology in the 1990 to 2000 time frame. No attempt was made to perform a detailed optimization of each ...
1980-11-01
A Flow Stress Formulation of Magnesium Alloy at Elevated Temperature
International Nuclear Information System (INIS)
Dynamic recrystallization (DRX) is the main softening mechanism of magnesium alloy AZ31B in hot deformation. Theoretically, in the flow rule the atomic diffusibility and the driving force of dislocation migration are dependent on the temperature, and the dislocation density and the cumulation of grain boundary energy are dependent on the strain rate. The peak stress will appear when the flow driving force and resistance force reach a balance, after which the stress descending will take place due to recrystallization fraction. Since the DRX is a thermally activated process, the recrystallized volume fraction can be regarded as the function of strain through Avrami equation. Based on this idea, the paper proposes a new constitutive model characterizing dynamic recrystallization for magnesium alloy AZ31B. The model is described by a peak stress and a strain softening rate, in which the peak stress depends only on Zener-Hollomon parameter and is determined through creep equation, and the ...
2007-05-17
A 3-D hydrodynamic dispersion model for modeling tracer transport in Geothermal Reservoirs
International Nuclear Information System (INIS)
A 3-D hydrodynamic dispersion model for tracer transport is developed and implemented into the TOUGH2 EOS3 (T2R3D) module. The model formulation incorporates a full dispersion tensor, based on a 3-D velocity field with a 3-D, irregular grid in a heterogeneous geological system. Two different weighting schemes are proposed for spatial average of 3-D velocity fields and concentration gradients to evaluate the mass flux by dispersion and diffusion of a tracer or a radionuclide. This new module of the TOUGH2 code is designed to simulate processes of tracer/radionuclide transport using an irregular, 3-D integral finite difference grid in non-isothermal, three-dimensional, multiphase, porous/fractured subsurface systems. The numerical method for this transport module is based on the integral finite difference scheme, as in the TOUGH2 code. The major assumptions of the tracer transport module are: (a) a tracer or a radionuclide is present and transported only within the ...
Sustainable water resources management in Pakistan
International Nuclear Information System (INIS)
Total river discharge in Pakistan in summer season vary from 3 thousand to 34 thousand cusses (100 thousand Cusses to 1,200 thousand Cusses) and can cause tremendous loss to human lives, crops and property, this causes the loss of most of the flood water in the lower Indus plains to the sea. Due to limited capacity of storage at Tarbela and Mangla Dams on river Indus and Jhelum, with virtually no control on Chenab, Ravi and Sutlej, devastating problems are faced between July and October in the event of excessive rainfall in the catchments. Due to enormous amounts of sediments brought in by the feeding rivers, the three major reservoirs -Tarbela, Mangla and Chashma will lose their storage capacity, by 25 % by the end of the year 2010, which will further aggravate the water-availability situation in Pakistan. The quality of water is also deteriorating due to urbanization and industrialization and agricultural developments. On the Environmental Front the main problems are water-logging ...
2004-06-07
The purpose of this study was to use high-resolution magnetic resonance (MR) imaging combined with image analysis to investigate the three-dimensional (3D) trabecular structure, anisotropy, and connectivity of human vertebral, femoral, and calcaneal specimens. The goal was to determine whether: (a) MR-derived measures depict known skeletal-site-specific differences in architecture and orientation of trabeculae; (b) 3D architectural parameters combined with bone mineral density (BMD) improve the prediction of the elastic modulus using a fabric tensor formulation; (c) MR-derived 3D architectural parameters combined with BMD improve the prediction of strength using a multiple regression model, and whether these results corresponded to the results obtained using higher resolution depictions of trabecular architecture. A total of 94 specimens (12 x 12 x 12 mm cubes) consisting of trabecular bone only were obtained, of which there were 7 from the calcaneus, 15 from ...
1998-05-01
Viscoplasticity of elastomeric materials: experimental facts and constitutive modelling
Energy Technology Data Exchange (ETDEWEB)
A characteristic of filled elastomers is their ability to undergo very large deformations without damaging their internal structure. The material behaviour is mainly elastic, however, elastomers show hysteresis effects leading to damping properties, which are quite important as regards their applications in various fields of mechanical engineering.A series of experiments (tension, torsion and combinations of both) was carried out on cylindrical bars made of a carbon-black filled rubber mixture. In addition to a pronounced nonlinear rate-dependence, relaxation and viscosity properties are observed as being influenced by the process histories.The behaviour of elastomeric materials is modelled on the basis of a free energy function and evolution equations for additional internal variables. Incorporating or disregarding the very small rate-independent hysteresis, the constitutive modelling may be classified under viscoplasticity or viscoelasticity. The constitutive equations are ...
2001-03-01
User`s guide and documentation manual for microbial transport simulator
Energy Technology Data Exchange (ETDEWEB)
The microbial transport simulator (MTS) is a three-dimensional, three-phase, multiple-component numerical model that permits the study of the transport of microorganisms and nutrients in porous media. Microbial parameters incorporated into MTS include: Microbial growth and decay, microbial deposition, chemotaxis, diffusion, convective dispersion, tumbling, and nutrient consumption. Governing equations for microbial and nutrient transport are coupled with continuity and flow equations under conditions appropriate for a black oil reservoir. The model`s mathematical formulations and preparation procedures of data files for conducting simulations using MTS are described. A general background of microbial transport simulation is given in Section I and the governing equations, mechanisms, and numerical solutions of MTS are given in Section II. Explanations for preparing an input data file with reservoir and microbial transport data are described in Section III, and ...
1993-10-01
Energy Technology Data Exchange (ETDEWEB)
The wavenumber-frequency spectral densities of turbulent wall pressure fluctuations are investigated over a rigid flat plate. Nonlinear Reynolds stress terms of the inhomogeneous Orr-Sommerfeld equation are regarded as a known forcing function. The forcing function is modeled after Bark{close_quote}s hydrodynamic bursting formulation. The inhomogeneous Orr-Sommerfeld equation is solved by the method of Eckhaus in terms of discrete homogeneous solutions. The method of Eckhaus is then extended and proved for the continuous Orr-Sommerfeld eigenfunctions. Turbulent wall pressure fluctuations in terms of wavenumber-frequency spectral densities are numerically computed and compared to the experimental results of Martin as well as to his transformation of Blake{close_quote}s data fitted to a modified Corcos model. The wavenumber-frequency spectral densities numerically computed from the discrete eigenfunctions compared well with Martin{close_quote}s transformations on the ...
1996-06-01
Toward Improving Prediction of Sediment Transport over Wave-Induced Ripples
Sediment transport over wave-induced ripples is a very complex phenomenon where available models fail to provide accurate predictions. For coastal engineering applications, the 1-DV advection-diffusion equation could be used with an additional parameter {\\alpha} related to the process of vortex shedding above ripples (Absi, 2010). The aim of this study is to provide simple practical analytical tools. An analytical eddy viscosity profile was validated by DNS data of turbulent channel flows (Absi et al., 2011). In this study, we will show that: (1) the period-averaged eddy viscosity in oscillatory boundary layers could be described by this simple analytical formulation; (2) The shape of the vertical profile is validated by period-averaged eddy viscosity of baseline (BSL) k-{\\omega} model (Suntoyo and Tanaka, 2009) for sinusoidal and asymmetric waves; (3) The vertical eddy viscosity profile depends on the wave non-linearity parameter and requires therefore a ...
2011-01-01
Thermodynamics in a turbocharged direct injection diesel engine
Energy Technology Data Exchange (ETDEWEB)
Software has been developed for the calculation of the thermodynamic cycle and the entropy changes in a turbocharged, direct injection, diesel engine based upon the measured cylinder pressure and a shaft encoder output. Assumptions of homogeneous mixture and equilibrium thermodynamic properties are made for the products of combustion and temporal variation in the fluid thermodynamic state is followed in a quasi-steady manner through a series of adjacent equilibrium states, each separated by finite intervals of one degree crank angle (1degCA). The thermodynamic properties are calculated by either of two equivalent formulations -- equilibrium constant or minimisation of Gibbs free energy, and are expressed in algebraic equations of the partial derivative of internal energy and gas constant with respect to temperature, pressure and equivalence ratio. The effect of the engine operating conditions on the thermodynamic cycle is studied, Results show that the dynamic fuel ...
1998-02-01
International Nuclear Information System (INIS)
A thermodynamic model for predicting the distribution coefficients has been developed by taking into account the extraction mechanism and the chloride complexation when Sm, Eu, Gd, Tb, Dy and Ho for single component systems are extracted from acidic chloride solutions by di-2-ethylhexyl ester in kerosene, respectively. The model equation includes two constants, of which one corresponds to the apparent extraction equilibrium constant and the other is due to the variation of the activity coefficients of organic species. These values are determined from a few experimental data by the curve fitting method. Then, the distribution coefficients under untried calculations, Bromley's formulation is used to estimate the activity coefficients of aqueous species and the interaction parameters for some rare earth chlorides are reported in terms of morality and molarity using data from Spedding et al. According to the authors the validity of this method has been confirmed by ...
Thermodynamic and kinetic aspects of surface acidity
Our research in the general area of acid catalysis involves the characterization of solid acidity and the corresponding assessment of catalytic performance of acidic materials. Acid characterization studies are required to provide essential information about the type of acid site (i.e., Lewis versus Bronsted), the strength of the sites, and the mobility of molecules adsorbed on the acid sites. An accurate measure of acid strength is given by the heat of adsorption of a basic probe molecule on the acid site. A thermodynamic representation of the mobility of adsorbed species on these sites is given by the entropy of adsorption. Important techniques used in these acid site characterization studies include microcalorimetry, thermogravimetric measurements, temperature programmed desorption, infrared spectroscopy and solid state nuclear magnetic resonance. The combination of these acid site characterization studies with reaction kinetics measurements of selected catalytic processes allows ...
1992-01-01
British Library Electronic Table of Contents (United Kingdom)
The preparation of neem oil microemulsion and its acaricidal activity in vitro was developed in this study. In these systems, the mixture of Tween-80 and the sodium dodecyl benzene sulfonate (SDBS) (4:1, by weight) was used as compound surfactant; the mixture of compound surfactant and hexyl alcohol (4:1, by weight) was used as emulsifier system; the mixture of neem oil, emulsifier system and water (1:3.5:5.5, by weight) was used as neem oil microemulsion. All the mixtures were stired in 800rpm for 15min at 40^oC. The acaricidal activity was measured by the speed of kill. The whole lethal time value of 10% neem oil microemulsion was 192.50min against Sarcoptes scabiei var. cuniculi larvae in vitro. The median lethal time value was 81.7463min with the toxicity regression equations of Y=-6.0...
2010-01-01
We continue our discussion of the general bosonic prototype of the new orbifold-string theories of permutation-type. Supplementing the extended physical-state conditions of the previous paper, we construct here the extended Virasoro generators with cycle central charge $\\hat{c}_j(\\sigma)=26f_j(\\sigma)$, where $f_j(\\sigma)$ is the length of cycle $j$ in twisted sector $\\sigma$. We also find an equivalent, reduced formulation of each physical-state problem at reduced cycle central charge $c_j(\\sigma)=26$. These tools are used to begin the study of the target space-time dimension $\\hat{D}_j(\\sigma)$ of cycle $j$ in sector $\\sigma$, which is naturally defined as the number of zero modes (momenta) of each cycle. The general model-dependent formulae derived here will be used extensively in succeeding papers, but are evaluated in this paper only for the simplest case of the "pure" permutation orbifolds.
2010-01-01
The Scientific Publications of Richard H. Dalitz, FRS (1925-2006)
Energy Technology Data Exchange (ETDEWEB)
Professor Richard H. Dalitz passed away on January 13, 2006. He was almost 81 years old and his outstanding contributions are intimately connected to some of the major breakthroughs of the 20th century in particle and nuclear physics. These outstanding contributions go beyond the Dalitz Plot, Dalitz Pair and CDD poles that bear his name. He pioneered the theoretical study of strange baryon resonances, of baryon spectroscopy in the quark model, and of hypernuclei, to all of which he made lasting contributions. His formulation of the ''{theta} - {tau} puzzle'' led to the discovery that parity is not a symmetry of the weak interactions. A brief scientific evaluation of Dalitz's major contributions to particle and nuclear physics is hereby presented, followed by the first comprehensive list of his scientific publications, as assembled from several sources. The list is divided into two categories: the first, main part ...
2006-03-29
The R-Parity Violating Minimal Supergravity Model
We present the minimal supersymmetric standard model with general broken R-parity, focusing on minimal supergravity (mSUGRA). We discuss the origins of lepton number violation in supersymmetry. We have computed the full set of coupled one-loop renormalization group equations for the gauge couplings, the superpotential parameters and for all the soft supersymmetry breaking parameters. We provide analytic formule for the scalar potential minimization conditions which may be iterated to arbitrary precision. We compute the low-energy spectrum of the superparticles and the neutrinos as a function of the small set of parameters at the unification scale in the general basis. Specializing to mSUGRA, we use the neutrino masses to set new bounds on the R-parity violating couplings. These bounds are up-to five orders of magnitude stricter than the previously existing ones. In addition, new bounds on the R-parity violating couplings are also derived demanding a non-tachyonic ...
2004-01-01
Support vector machines for nuclear reactor state estimation
Energy Technology Data Exchange (ETDEWEB)
Validation of nuclear power reactor signals is often performed by comparing signal prototypes with the actual reactor signals. The signal prototypes are often computed based on empirical data. The implementation of an estimation algorithm which can make predictions on limited data is an important issue. A new machine learning algorithm called support vector machines (SVMS) recently developed by Vladimir Vapnik and his coworkers enables a high level of generalization with finite high-dimensional data. The improved generalization in comparison with standard methods like neural networks is due mainly to the following characteristics of the method. The input data space is transformed into a high-dimensional feature space using a kernel function, and the learning problem is formulated as a convex quadratic programming problem with a unique solution. In this paper the authors have applied the SVM method for data-based state estimation in nuclear power reactors. In ...
2000-02-14
Structure of Mg$_n$ and Mg$_n^+$ clusters up to n=30
We present structure calculations of neutral and singly ionized Mg clusters of up to 30 atoms, as well as Na clusters of up to 10 atoms. The calculations have been performed using density functional theory (DFT) within the local (spin-)density approximation, ion cores are described by pseudopotentials. We have utilized a new algorithm for solving the Kohn-Sham equations that is formulated entirely in coordinate space and, thus, permits straightforward control of the spatial resolution. Our numerical method is particularly suitable for modern parallel computer architectures; we have thus been able to combine an unrestricted simulated annealing procedure with electronic structure calculations of high spatial resolution, corresponding to a plane-wave cutoff of 954eV for Mg. We report the geometric structures of the resulting ground-state configurations and a few low-lying isomers. The energetics and HOMO-LUMO gaps of the ground-state configurations are carefully ...
2011-01-01
Strategic principles workshops: Discussion drafts and workshop notes
Energy Technology Data Exchange (ETDEWEB)
The Office of Civilian Radioactive Waste-Management in the Department of Energy (DOE) is responsible for disposing of this nation`s spent fuel and high-level radioactive waste in a manner that protects the health and safety of the public and the quality of the environment. Although embodied in the Federal repository program that began with studies in the late 1950s, this mission was explicitly established by the Nuclear Waste Policy Act of 1982 and reaffirmed by the Nuclear Waste Policy Amendments Act of 1987. To fulfill our mission, we are developing a waste management system consisting of a geologic repository for permanent disposal deep beneath the surface of the earth, a facility for monitored retrievable storage, and a system for transporting the waste. This discussion draft was developed to help involve parties affected by or interested in the waste-management program in the formulation of the basic principles on which the program will be based. It reviews ...
1991-09-01
Steady-state Ab Initio Laser Theory: Generalizations and Analytic Results
We improve the steady-state ab initio laser theory (SALT) of Tureci et al. by expressing its fundamental self-consistent equation in a basis set of threshold constant flux states that contains the exact threshold lasing mode. For cavities with non-uniform index and/or non-uniform gain, the new basis set allows the steady-state lasing properties to be computed with much greater efficiency. This formulation of the SALT can be solved in the single-pole approximation, which gives the intensities and thresholds, including the effects of nonlinear hole-burning interactions to all orders, with negligible computational effort. The approximation yields a number of analytic predictions, including a "gain-clamping" transition at which strong modal interactions suppress all higher modes. We show that the single-pole approximation agrees well with exact SALT calculations, particularly for high-Q cavities. Within this range of validity, it provides an extraordinarily efficient ...
2010-01-01
Stakeholder-based SWOT analysis for successful municipal solid waste management in Lucknow, India
International Nuclear Information System (INIS)
The present investigation is a case study of Lucknow, the main metropolis in Northern India, which succumbs to a major problem of municipal solid waste and its management. A qualitative investigation using strengths, weaknesses, opportunities and threats analysis (SWOT) has been successfully implemented through this community participation study. This qualitative investigation emphasizes the limited capabilities of the municipal corporation's resources to provide proper facilitation of the municipal solid waste management (MSWM) services without community participation in Lucknow city. The SWOT analysis was performed to formulate strategic action plans for MSWM in order to mobilize and utilize the community resources on the one hand and municipal corporation's resources on the other. It has allowed the introduction of a participatory approach for better collaboration between the community and municipal corporation in Lucknow (India). With this stakeholder-based ...
2260-01-01
Sensitivity analysis of parameters affecting radon barrier cover thickness
International Nuclear Information System (INIS)
The sensitivity analysis summarized in this paper was made to determine the parameters of greatest influence in the prediction of radon barrier cover thickness for the stabilization of uranium mill tailings piles. Such information provides the basis for setting priorities and levels of effort for data collection, and improves knowledge of the sources of uncertainty in the calculation of cover thickness. In the context of this paper, the influence of a parameter on cover thickness incorporates two effects: (1) the sensitivity of the mathematical formulation to changes in a parameter's value, and (2) the range of values that a parameter may take on under site-specific conditions. Of the several parameters that are used in the calculations, the most influential are cover moisture content, cover radon diffusion coefficient, tailings radium concentration and tailings radon emanating fraction, in order of decreasing relative influence. Less influential parameters for ...
Safeguards and Security Technology Development Directory. FY 1993
Energy Technology Data Exchange (ETDEWEB)
The Safeguards and Security Technology Development Directory is published annually by the Office of Safeguards and Security (OSS) of the US Department of Energy (DOE), and is Intended to inform recipients of the full scope of the OSS R&D program. It is distributed for use by DOE headquarters personnel, DOE program offices, DOE field offices, DOE operating contractors, national laboratories, other federal agencies, and foreign governments. Chapters 1 through 7 of the Directory provide general information regarding the Technology Development Program, including the mission, program description, organizational roles and responsibilities, technology development lifecycle, requirements analysis, program formulation, the task selection process, technology development infrastructure, technology transfer activities, and current research and development tasks. These chapters are followed by a series of appendices which contain more specific information on aspects of the ...
1993-06-01
Rotor-stator and disc systems for emulsification processes
Energy Technology Data Exchange (ETDEWEB)
Emulsions now find a wide range of applications in industry and daily life. In the pharmaceutical industry lipophilic active ingredients as well as many nutritional products such as vitamins are often formulated in the dispersed phase of oil-in-water emulsions. Emulsions can be produced with different mechanical emulsification techniques. In the following review, the process of rotor-stator systems and disc systems are compared to other popular mechanical emulsification systems. On the basis of experimental results from the authors' laboratory, a discontinuous gear-rim dispersing system, discontinuous disc system, and a continuous high pressure system are compared with regard to their attainable mean droplet diameter and drop size distribution in an oil-in-water emulsion. It can be shown that dissolver discs with a very simple geometry attain very small mean droplet diameters and a very narrow droplet size distribution, comparable to the emulsions obtained ...
2006-01-01
Role of the triple bond in acid corrosion inhibition
It is now over 30 yr since the original discovery was made that acetylenic compounds are effective in inhibiting the corrosion of iron in acid media. Since then, the industrial practice of oil-well acidizing has become well-established, with key acetylenic compounds such as propargyl alcohol, hexynol, and ethyl octynol assuming increasingly important roles. New and more stable triple-bonded compounds properly formulated and synergized with nitrogen compounds are expected to be used more extensively as temperature, stability, and performance requirements increase. An evaluation is made of the structural features which enhance or limit the corrosion performance of a given acetylenic. New data involving mixtures of acetylenics, hydrogen-bonded complexes, and the use of new nitrogen synergists are covered also. Tabular data at 200/sup 0/F approximate the more strenuous conditions of an oil-well acidizing job using N-80 tubing. The performance of such inhibitors as ...
1970-01-01
Residence time probability analysis of sulfur concentrations at Grand Canyon National Park
Energy Technology Data Exchange (ETDEWEB)
A statistical method is developed to determine the locations of major pollutant sources affecting a distant downwind receptor, provided that air trajectories can be estimated. Probability density functions are estimated which indicate the overall residence time of air parcels over a given geographic region as they travel toward a receptor and residence time for the case of high pollutant concentrations at the receptor. These functions are used to estimate a conditional probability function which indicates the potential for a source region to contribute to high air pollution concentrations. Finally, a source contribution function is formulated to indicate the relative contribution of different source regions to high concentrations at the receptor. The method is tested using data collected at Grand Canyon National Park in 1980. The dominant pathway for air masses arriving at Grand Canyon during this period was southern California. A lesser pathway was from the border ...
1985-01-01
Replacement of fishmeal in cobia (Rachycentron canadum) diets using poultry by-product meal
British Library Electronic Table of Contents (United Kingdom)
An 8-week feeding trial was conducted to evaluate the use of local poultry by-product meal (PBM) in replacement of imported fishmeal in the diets of cobia, Rachycentron canadum. Six isolipidic (12%) and isoproteic (45%) experimental diets were formulated using PBM to replace fishmeal at 20, 40, 60, 80 and 100% dietary protein. Eleven juvenile cobia (initial mean weight of 30.7???0.78?g) were randomly stocked in 300-L circular fibreglass tanks and hand-fed based on the total biomass of each tank, twice a day at 0900?h and 1500?h. The fish were group weighed at 2-week intervals to monitor their growth performance in order to adjust the feeding ratio. At the end of the feeding trial, weight gains (WGs) ranging from 221 to 322% were obtained. The specific growth rate (SGR), WG and protein effi...
2011-01-01
Regional integrated solid waste management: an optimization model for northern Lebanon
International Nuclear Information System (INIS)
Full text.Increased environmental concerns and the emphasis on material and energy recovery are gradually changing the orientation of municipal solid waste (MSW) management and planning. In this context, the application of optimization techniques have been introduced to design the least cost solid waste management systems, considering the variety of management processes (recycling, composting, anaerobic digestion, incineration and land filling) and the existence of uncertainties associated with the number of system components and their interrelations. This study presents a model that was developed and applied to serve as a solid socio-economic and environmental considerations. The model accounts for solid waste generation rates, composition, collection, treatment, disposal as well as potential environmental impacts of various MSW management techniques. The model follows a linear programming formulation with the framework of dynamic optimization. The model can serve ...
2000-11-23
Reclaiming silver from silver zeolite
Energy Technology Data Exchange (ETDEWEB)
Silver zeolite is used to capture radioiodines from air cleaning systems in some nuclear facilities at the Idaho National Engineering Laboratory. It may become radioactively contaminated and/or poisoned by hydrocarbon vapors, which diminishes its capacity for iodine. Silver zeolite contains up to 38 wt% silver. A pyrometallurgical process was developed to reclaim the silver before disposing of the unserviceable zeolite as a radioactive waste. A flux was formulated to convert the refractory aluminosilicate zeolite structure into a low-melting fluid slag, with Na{sub 2}O added as NAOH instead of Na{sub 2}CO{sub 3} to avoid severe foaming due to CO{sub 2} evolution. A propane-fired furnace was built to smelt 45 kg charges at 1300C in a carbon-bonded silicon carbide crucible. A total of 218 kg (7000 tr oz) of silver was reclaimed from 1050 kg of unserviceable zeolite. Silver recoveries of 97% were achieved, and the radioisotopes were fixed as stable silicates in a ...
1991-10-01
Realisations of classical and quantum W_3 symmetry
International Nuclear Information System (INIS)
We consider realisations of Zamolodchikov's nonlinear W_3 algebra at the classical and quantum level. Recent work has produced gaugings of the classical W_3 algebra starting from a theory of n scalar fields #PHI#"i, given the existence of a set of coefficients d_i_j_k satisfying a certain algebraic identity. We note that a solution exists for each Jordan algebra determined by a cubic norm form, leading to an infinite family of 'generic' models for all n, plus four special cases with n = 5, 8, 14 and 26. Taking free-field ansaetze for the spin-two and spin-three currents, we then formulate the conditions for the quantum W_3 algebra to be satisfied. We show how the generic classical models may be extended to the quantum case for every n, reducing to the construction of Fateev and Zamolodchikov for n = 2. These models are seen to be examples of a completely general construction, which produces a realisation of W_3 from an arbitrary realisation of the Virasoro algebra ...
1991-04-01
QoS-Aware Joint Policies in Cognitive Radio Networks
One of the most challenging problems in Opportunistic Spectrum Access (OSA) is to design channel sensing-based protocol in multi secondary users (SUs) network. Quality of Service (QoS) requirements for SUs have significant implications on this protocol design. In this paper, we propose a new method to find joint policies for SUs which not only guarantees QoS requirements but also maximizes network throughput. We use Decentralized Partially Observable Markov Decision Process (Dec-POMDP) to formulate interactions between SUs. Meanwhile, a tractable approach for Dec-POMDP is utilized to extract sub-optimum joint policies for large horizons. Among these policies, the joint policy which guarantees QoS requirements is selected as the joint sensing strategy for SUs. To show the efficiency of the proposed method, we consider two SUs trying to access two-channel primary users (PUs) network modeled by discrete Markov chains. Simulations demonstrate three interesting ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
A generalized approach to the analysis of the effects of transmission line faults on natural gas transmission pipelines has been developed and is presented in this report. A state of the art user-friendly computational tool has been developed and verified for the analysis of interference between electrical power lines and nearby buried or above-ground pipelines. This computer program, ECCAPP, is distinguished by its ability to model and analyze accurately complex, realistic interactions between pipelines and power lines, using easily obtained input data. The final report consists of three volumes. An independent fourth volume was also developed to simplify the installation of the ECCAPP software. This report, volume 1, contains the theory upon which the ECCAPP computer program is based. A parametric analysis and graphical charts have been formulated using ECCAPP to permit estimates to be made in the field or during preliminary analyses for situations that are not ...
1987-11-01
Energy Technology Data Exchange (ETDEWEB)
Biogas, produced from anaerobic digestion of organic matter in domestic, industrial and rural wastewaters and residuals, represent an alternative and renewable source of energy, with growing use worldwide. In Brazil, high population and its spatial concentration and expressive agricultural and agricultural-industrial production indicate a substantial potential of biogas production. The results presented in this work show a potential of biogas production of almost 2 billion cubic feet a day of CH{sub 4}. Viability of biogas production and use depends substantially on project scale. Generally, biogas projects are viable from landfills and domestic wastewater treatment for populations higher than 50,000 inhabitants and swine and dairy farms with at least 5,000 and 1,000 animals, respectively. Biogas is also competitive when compared to fossil fuels used in industry and transport. Despite incentive mechanisms for biogas production and use, like Clean Development Mechanism and renewable and ...
2009-12-15
Energy Technology Data Exchange (ETDEWEB)
This work deals with a new route to modify polymer blend morphology in order to improve the porosity of gas diffusion layers (GDLs) for proton exchange membrane fuel cells (PEMFCs). First, electrically conductive polymer-based blends were carefully formulated using a twin-screw extrusion process. Blend electrical conductivity was ensured by the addition of high specific surface area carbon black and synthetic graphite flakes. Final GDL porosity, in particular its macroporosity, was generated by melt blending polyamide 11 (PA11) matrix with polystyrene (PS) followed by PS extraction with tetrahydrofuran (THF) solvent at room temperature. In order to improve GDL porosity by the optimisation of PS dispersion in the PA11 matrix, PA11/PS blends were compatibilised by the addition of 2 wt.-% of clay. It was observed that both macroporosity and pore size distribution were beneficially modified after blend compatibilisation. Final GDL conductivity of about 1.25 S cm{sup ...
2007-12-15
Pole placement technique for PSS and TCSC-based stabilizer design using simulated annealing
Energy Technology Data Exchange (ETDEWEB)
A pole placement technique for power system stabilizer (PSS) and thyristor controlled series capacitor (TCSC) based stabilizer using simulated annealing (SA) algorithm is presented in this paper. The proposed approach employs SA optimization technique to PSS (SAPSS) and TCSC-based stabilizer (SACSC) design. The design problem is formulated as an optimization problem where SA is applied to search for the optimal setting of the proposed SAPSS and SACSC parameters. A pole placement-based objective function to shift the dominant eigenvalues to the left in the s-plane is considered. The proposed SAPSS and SACSC have been examined on a weakly connected power system with different disturbances, loading conditions, and system parameter variations. Eigenvalue analysis and nonlinear simulation results show the effectiveness and the robustness of the proposed stabilizers and their ability to provide efficient damping of low frequency oscillations. In addition, the performance ...
2000-11-01
Phenomenological 3D and 1D consistent models for shape-memory alloy materials
The paper deals with the modeling and the development of a numerical procedure for the analysis of shape-memory alloy (SMA) elements in order to predict the main features of SMA devices. A 3D SMA model in the framework of small strain theory is developed starting from the thermo-mechanical model proposed by Souza et al. (Eur J Mech A/Solids 17:789-806, 1998) and modified by Auricchio and Petrini (Int J Numer Methods Eng 55:1255-1284, 2002). The aim of this paper is to propose some more modifications to the original model, to derive its consistent 1D formulation, to clarify the mechanical meaning of the material parameters governing the constitutive model. A robust time integration algorithm is developed in the framework of the finite element method and a new beam finite element is proposed. Some numerical applications and a comparison with experimental data available in literature are carried out in order to assess the ability of the proposed model to describe the ...
2009-08-01
Persistence of terbufos and its metabolites in soil and maize
International Nuclear Information System (INIS)
Degradation of "1"4C terbufos was studied under greenhouse conditions. A mixture of "1"4C labelled compound (2.48 x 10"4 Bq of O-ethyl-1- "1"4C) und unlabelled compound (0.09 g of the granule formulation Counter 10 G) was applied to pots containing 750 g of sandy loam clay Ultisol soil with 4.9% organic matter and a cation exchange capacity of 7.6. Two treatments were established, one where maize (cultivar Cristiani) was grown and the other without plants. The soil and plants were extracted at 0, 4, 8, 16, 32 and 64 days and analyzed by a liquid scintillation counter, gas chromatography-flame photometric detector (GC-FPD) and autoradiography. The total "1"4C compounds extracted on day 64 were 31 #+-# 5.6% of the radioactivity applied in the treatments with plants and 46.1 #+-# 1.1% without plants. From the autoradiography results it can be concluded that all times the compounds identified by this technique were terbufos, terbufos sulphoxide and terbufos sulphone. ...
1996-07-01
International Nuclear Information System (INIS)
A path integral evaluation of the Green's function for the hydrogen atom initiated by Duru and Kleinert is studied by recognizing it as a special case of the general treatment of the separable Hamiltonian of Liouville type. The basic dynamical principle involved is identified as Jacobi's principle of least action for given energy which is reparametrization invariant, and thus the appearance of a gauge freedom is naturally understood. The separation of variables in the operator formalism corresponds to a choice of gauge in the path integral, and the Green's function is shown to be gauge independent if the operator ordering is properly taken into account. Unlike the conventional Feynman path integral, which deals with a space-time picture of particle motion, the path integral on the basis of Jacobi's principle sums over orbits in space. We illustrate these properties by evaluating an exact path integral of the Green's function for the hydrogen atom in parabolic coordinates, and thus ...
Energy Technology Data Exchange (ETDEWEB)
The study of natural convection flow and heat transfer within a cylindrical annulus has received considerable attention because of its numerous applications, such as in nuclear reactor design, electronic component cooling, thermal storage systems, energy conservation, energy storage, and energy transmission. Here, the effects of multiple geometric perturbations on the inner and outer cylinders of an annulus with impermeable end walls are investigated in this work. A three-dimensional study was done using a numerical scheme based on a Galerkin method of finite element formulation. The nature of the buoyancy-induced flow field has been analyzed in detail. The flow fields for the cases considered were found to be qualitatively similar, and the introduction of each additional perturbation altered the flow field in a regular and recurring manner. The introduction of each perturbation on the outer cylinder causes clockwise and counterclock-wise rotating patterns on ...
1999-05-14
International Nuclear Information System (INIS)
The study of natural convection flow and heat transfer within a cylindrical annulus has received considerable attention because of its numerous applications, such as in nuclear reactor design, electronic component cooling, thermal storage systems, energy conservation, energy storage, and energy transmission. Here, the effects of multiple geometric perturbations on the inner and outer cylinders of an annulus with impermeable end walls are investigated in this work. A three-dimensional study was done using a numerical scheme based on a Galerkin method of finite element formulation. The nature of the buoyancy-induced flow field has been analyzed in detail. The flow fields for the cases considered were found to be qualitatively similar, and the introduction of each additional perturbation altered the flow field in a regular and recurring manner. The introduction of each perturbation on the outer cylinder causes clockwise and counterclock-wise rotating patterns on ...
1999-05-14
Organization of bulk power markets: A concept paper
Energy Technology Data Exchange (ETDEWEB)
The electricity industry in the US today is at a crossroads. The restructuring debate going on in most regions has made it clear that the traditional model of vertically integrated firms serving defined franchise areas and regulated by state commissions may not be the pattern for the future. The demands of large customers seeking direct access to power markets, the entry of new participants, and proposed reforms of the regulatory process all signify a momentum for fundamental change in the organization of the industry. This paper addresses electricity restructuring from the perspective of bulk power markets. The authors focus attention on the organization of electricity trade and the various ways it has been and might be conducted. Their approach concentrates on conceptual models and empirical case studies, not on specific proposals made by particular utilities or commissions. They review literature in economics and power system engineering that is relevant to the major questions. The ...
1995-12-01
Optimization of sorghum-methane production systems
Energy Technology Data Exchange (ETDEWEB)
This dissertation concerns a study of the utilization of sorghum biomass as the fuel for a methane production system. The objective of this research is to determine an optimal sorghum-methane production system based on anaerobic batch digestion technology. The system is described as the interaction of three components: estimation of available biomass, storage of biomass, and the gas production. Levelized costs are obtained for each component. The biomass supply is assumed to decay exponentially in quality with storage time. The gas production process is a batch type of digestion with an exponential production rate. Gas production is formulated for a fixed planning horizon (one year) as a function of the number of batches and the batch residence times. The cost equation is then described as a function of these gas production equations and their levelized costs. The structure of this resulting equation is exploited to obtain the minimum unit gas cost. This analysis ...
1984-01-01
Energy Technology Data Exchange (ETDEWEB)
The paper is concerned with the economic operation of power systems comprising pumped storage and thermal plants. In power systems, pumped storage plants may receive the energy required for pumping water either from the system in which they are integrated or from a neighbouring system. Therefore, two mathematical formulations of the problem are presented depending on the source of energy during pumping. In both cases, the problem is reduced to a non linear optimization problem. Two numerical techniques are suggested for the solution of this optimization problem, namely the Lagrangian Multipliers technique and the Rosen Gradient Projection technique. Numerical examples are presented to demonstrate the techniques. Although the Lagrangian Multipliers technique has the advantage of being a well known technique, however, computer wise, the Rosen Gradient Projection technique proves to be more efficient. The results of the numerical examples given show that mechanical ...
1980-12-01
On the optimal environmental liability limit for marine oil transport
Energy Technology Data Exchange (ETDEWEB)
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 properties of the model and major factors affecting the public policy decision regarding a liability limit. ...
1999-07-01
International Nuclear Information System (INIS)
This specialist meeting on Advanced Instrumentation and Measurements Techniques was held in Santa Barbara (USA) in 1997 and attracted some 70 participants in ten technical sessions and a session of the round table discussions, with a total of 41 papers. It was intended to bring together the international experts in multi-phase flow instrumentation, experiment and modeling to review the state-of-the-art of the two-phase flow instrumentation methods and to discuss the relation between modeling needs and instrumentation capabilities. The following topics were included: Modeling needs and future direction for improved constitutive relations, interfacial area transport equation, and multi-dimensional two-fluid model formulation; local instrumentation developments for void fraction, interfacial area, phase velocities, turbulence, entrainment, particle size, thermal non-equilibrium, shear stress, nucleation, condensation and boiling; global instrumentation developments ...
1997-03-17
In this article, we describe an approach to model the electromechanical behavior of the skeletal muscle based on the Huxley formulation. We propose a model that complies with a well established macroscopic behavior of striated muscles where force-length, force-velocity, and Mirsky-Parmley properties are taken into account. These properties are introduced at the microscopic scale and related to a tentative explanation of the phenomena. The method used integrates behavior ranging from the microscopic to the macroscopic scale, and allows the computation of the dynamics of the output force and stiffness controlled by EMG or stimulation parameters. The model can thus be used to simulate and carry out research to develop control strategies using electrical stimulation in the context of rehabilitation. Finally, through animal experiments, we estimated model parameters using a Sigma Point Kalman Filtering technique and dedicated experimental protocols in isometric ...
2011-07-15
Multi-objective optimization of a dimpled channel for heat transfer augmentation
Energy Technology Data Exchange (ETDEWEB)
Staggered arrays of dimples printed on opposite surfaces of a cooling channel is formulated numerically and optimized with hybrid multi-objective evolutionary algorithm and Pareto optimal front. As Pareto optimal front produces a set of optimal solutions, the trends of objective functions with design variables are predicted by hybrid multi-objective evolutionary algorithm. The problem is defined by three non-dimensional geometric design variables composed of dimpled channel height, dimple print diameter, dimple spacing, and dimple depth, to maximize heat transfer rate compromising with pressure drop. Twenty designs generated by Latin hypercube sampling were evaluated by Reynolds-averaged Navier-Stokes solver and the evaluated objectives were used to construct Pareto optimal front through hybrid multi-objective evolutionary algorithm. The optimum designs were grouped by k-means clustering technique and some of the clustered points were evaluated by flow analysis. ...
2008-12-15
Multi-objective optimization of a dimpled channel for heat transfer augmentation
Staggered arrays of dimples printed on opposite surfaces of a cooling channel is formulated numerically and optimized with hybrid multi-objective evolutionary algorithm and Pareto optimal front. As Pareto optimal front produces a set of optimal solutions, the trends of objective functions with design variables are predicted by hybrid multi-objective evolutionary algorithm. The problem is defined by three non-dimensional geometric design variables composed of dimpled channel height, dimple print diameter, dimple spacing, and dimple depth, to maximize heat transfer rate compromising with pressure drop. Twenty designs generated by Latin hypercube sampling were evaluated by Reynolds-averaged Navier-Stokes solver and the evaluated objectives were used to construct Pareto optimal front through hybrid multi-objective evolutionary algorithm. The optimum designs were grouped by k-means clustering technique and some of the clustered points were evaluated by flow analysis. ...
2008-12-01
Multi-Objective Optimization of Cooling Channel Roughened by Dimples
Shape optimization of heat transfer augmentation device employed in turbine blade internal cooling passage has been performed numerically using single as well as multi-objective optimization procedures. Polynomial response surface approximation method and multi-objective genetic algorithm are used for single and multi-objective optimizations, respectively. Problem to enhance heat transfer rate considering staggered dimples on single surface of cooling passage has been formulated, and Reynolds-averaged Navier-Stokes equations are solved to analyze the flow field and the heat transfer. Three design variables defining channel and dimple dimensions, and two objective functions related to Nusselt number and friction drag are employed. Latin hypercube sampling is used to generate sampling points in design space, and the evaluated objectives are used to generate a set of optimal designs. Optimal shapes show higher heat transfer rates in the case of lower channel height, ...
2008-01-01
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 stability, angle of repose, dusting, etc.; a ...
1993-01-01
International Nuclear Information System (INIS)
We investigate some aspects of the radiation damage mechanisms in biomolecules, focusing on the modelling of resonant fragmentation caused by the attachment of low-energy electrons (LEEs) initially ejected by biological tissues when exposed to ionizing radiation. Scattering equations are formulated within a symmetry-adapted, single-center expansion of both continuum and bound electrons, and the interaction forces are obtained from a combination of ab initio calculations and a nonempirical model of exchange and correlation effects developed in our group. We present total elastic scattering cross-sections and resonance features obtained for the equilibrium geometries of glycine, alanine, proline and valine. Our results at those geometries of the target molecules are briefly shown to qualitatively explain some of the fragmentation patterns obtained in experiments. We further carry out a one-dimensional (1D) modeling for the dynamics of intramolecular energy transfers ...
2010-10-01
Energy Technology Data Exchange (ETDEWEB)
A testing program has been conducted by the Westinghouse Hanford Company to confirm the baseline waste form selection for use in Waste Receiving and Processing (WRAP) Module 2A. WRAP Module 2A will provide treatment required to properly dispose of containerized contact-handled, mixed low-level waste at the US Department of Energy Hanford Site in south-central Washington State. Solidification/stabilization has been chosen as the appropriate treatment for this waste. This work is intended to test cement-based, thermosetting polymer, and thermoplastic polymer solidification media to substantiate the technology approach for WRAP Module 2A. Screening tests were performed using the major chemical constituent of each waste type to measure the gross compatibility with the immobilization media and to determine formulations for more detailed testing. Surrogate materials representing each of the eight waste types were prepared in the laboratory. These surrogates were then ...
1993-10-01
In dissipative ordinary differential equation systems different time scales cause anisotropic phase volume contraction along solution trajectories. Model reduction methods exploit this for simplifying chemical kinetics via a time scale separation into fast and slow modes. The aim is to approximate the system dynamics with a dimension-reduced model after eliminating the fast modes by enslaving them to the slow ones via computation of a slow attracting manifold. We present a novel method for computing approximations of such manifolds using trajectory-based optimization. We discuss Riemannian geometry concepts as a basis for suitable optimization criteria characterizing trajectories near slow attracting manifolds and thus provide insight into fundamental geometric properties of multiple time scale chemical kinetics. The optimization criteria correspond to a suitable mathematical formulation of "minimal relaxation" of chemical forces along reaction trajectories under ...
2009-01-01
Metallization of large silicon wafers. Final report
A metallization scheme has been developed which allows selective plating of silicon solar cell surfaces. The system is comprised of three layers. Palladium, through the formation of palladium silicide at 300/sup 0/C in nitrogen, makes ohmic contact to the silicon surface. Nickel, plated on top of the palladium silicide layer, forms a solderable interface. Lead-tin solder on the nickel provides conductivity and allows a convenient means for interconnection of cells. To apply this metallization, three chemical plating baths are employed. Palladium is deposited with an immersion palladium solution and an electroless palladium solution, and nickel is deposited with an electroless nickel solution. Solder is applied with a molten solder dip. Extensive development work has been performed to achieve an effective immersion palladium solution formulation, leading to reproducible formation of the palladium silicide contact layer. This metallization system has been repeatedly ...
Measurement of the enrichment of uranium in the pipework of a gas centrifuge enrichment plant
Energy Technology Data Exchange (ETDEWEB)
The US and UK have been separately working on the development of a NDA instrument to determine the enrichment of gaseous UF/sub 6/ at low pressures in cascade header pipework in line with the conclusions of the Hexapartite Safeguards Project viz. the instrument is capable of making a ''go/no go'' decision of whether the enrichment is less than/greater than 20%. Recently, there has been a series of very useful technical exchanges of ideas and information between the two countries. This has led to a technical formulation for such an instrumentation based on ..gamma..-ray spectrometry which, although plant-specific in certain features, nevertheless is based on the same physical principles. Experimental results from commercially operating enrichment plants are very encouraging and indicate that a complete measurement including set up time on the pipe should be attainable in about 30 minutes when measuring pipes of diameter around 110 ...
1985-01-01
Linear augmented-plane-wave calculation of the structural properties of bulk Cr, Mo, and W
International Nuclear Information System (INIS)
A scalar-relativistic procedure for calculating the valence-electron contribution to the total energy of bulk and thin-film solids has been developed and applied to the fcc and bcc phases of the group-VIB transition elements Cr, Mo, and W. This approach, which is based on the linear augmented-plane-wave method and local-density-functional theory, contains no shape approximations for either the charge density or potential. The formulation adopts a rigid-core approximation and incorporates an exact treatment of the core-charge tails that extend beyond the muffin-tin spheres. The application of this procedure to bcc Cr, Mo, and W yields calculated lattice parameters and bulk moduli that are in good (Cr) to excellent (Mo and W) agreement with experiment. The present calculated properties also agree quite well with the results of previous calculations involving a variety of band-structure methods. The calculated fcc-bcc energy difference for Cr, Mo, and W increases in a ...
International Nuclear Information System (INIS)
Radiation-and-thermal-combined degradation of some kinds of cable insulating and jacketing materials was evaluated by accelerated aging tests. Plasticized polyvinyl chloride (PVC), silicone rubber, crosslinked and non-crosslinked halogen-free flame-retardant polyolefins (NH-XLPO and NH-PO) and ethylene-propylene rubber (EP rubber) of experimental formulation were degraded at accelerated rates, that are 50-1000 times the degradation rate under standard conditions (e.g.; 1Gy/h, 50degC), and a method to assess the lifetime of these materials under standard conditions was studied. The degradation was investigated by measuring tensile properties. In the accelerated aging tests, rates of elongation decrease owing to degradation for these materials were in proportion to the increase in accelerated rate. The PVC lifetime estimated from sequential aging tests had a tendency to extend beyond that from simultaneous aging tests, while the lifetime of other materials estimated ...
1994-01-01
Energy Technology Data Exchange (ETDEWEB)
Radiation-and-thermal-combined degradation of ethylene-propylene rubber (EP rubber) and chlorosulfonated polyethylene (CSM) as cable insulating and jacketing materials were evaluated by accelerated aging tests and a method to assess the lifetime of these materials under practical application was studied. EP rubber and CSM of experimental formulation were degraded at accelerated rates, that are 50 [approx] 1000 times the degradation rate under a standard condition (1Gy/h, 50degC). The degradation was investigated by measuring the tensile properties. In the accelerated aging tests, rates of elongation decrease owing to degradation for both EP rubber and CSM were in proportion to increase in accelerated rate. Behaviors of elongation changes showed little difference with accelerated rate. EP rubber lifetime estimated from sequential aging test had a tendency to extend beyond that from simultaneous aging test, while CSM lifetime estimated from both aging tests were ...
1992-10-01
International Nuclear Information System (INIS)
Radiation-and-thermal-combined degradation of ethylene-propylene rubber (EP rubber) and chlorosulfonated polyethylene (CSM) as cable insulating and jacketing materials were evaluated by accelerated aging tests and a method to assess the lifetime of these materials under practical application was studied. EP rubber and CSM of experimental formulation were degraded at accelerated rates, that are 50 #approx# 1000 times the degradation rate under a standard condition (1Gy/h, 50degC). The degradation was investigated by measuring the tensile properties. In the accelerated aging tests, rates of elongation decrease owing to degradation for both EP rubber and CSM were in proportion to increase in accelerated rate. Behaviors of elongation changes showed little difference with accelerated rate. EP rubber lifetime estimated from sequential aging test had a tendency to extend beyond that from simultaneous aging test, while CSM lifetime estimated from both aging tests were ...
1992-01-01
Laboratory ageing of transformer oils
Energy Technology Data Exchange (ETDEWEB)
The insulating oil used in a transformer is a critical component, as its service life is typically 20 years with possibly little or no maintenance. Partial discharges (PD), thermal overloads and static discharges continually subject the oil to chemical deterioration during its operating life. To ensure equipment reliability during service, it is important that the initial quality of the new insulating oil should meet the required acceptance specifications and preferably be pre-tested before use. Accelerated aging tests have been devised to determine the life expectancy of oil in service by using forced air or oxygen flow into the oil, the presence of a copper catalyst, and at elevated temperatures. The more important standards relating to transformer application are discussed and highlights of the more important aspects of the oxidation chemistry of hydrocarbons are included. The ultimate aim of the project is the formulation of better standard testing methods and ...
1996-04-01
Kinetic Modeling of Gasoline Surrogate Components and Mixtures under Engine Conditions
Energy Technology Data Exchange (ETDEWEB)
Real fuels are complex mixtures of thousands of hydrocarbon compounds including linear and branched paraffins, naphthenes, olefins and aromatics. It is generally agreed that their behavior can be effectively reproduced by simpler fuel surrogates containing a limited number of components. In this work, an improved version of the kinetic model by the authors is used to analyze the combustion behavior of several components relevant to gasoline surrogate formulation. Particular attention is devoted to linear and branched saturated hydrocarbons (PRF mixtures), olefins (1-hexene) and aromatics (toluene). Model predictions for pure components, binary mixtures and multicomponent gasoline surrogates are compared with recent experimental information collected in rapid compression machine, shock tube and jet stirred reactors covering a wide range of conditions pertinent to internal combustion engines (3-50 atm, 650-1200K, stoichiometric fuel/air mixtures). Simulation results ...
2010-01-11
Iofetamine HCI {sup 123}I (IMP)
Energy Technology Data Exchange (ETDEWEB)
Iofetamine HCI {sup 123}I is the generic name for the hydrochloride salt of N-isopropyl-p-iodoamphetamine labeled with {sup 123}I, commonly called IMP. Iofetamine HCI {sup 123}I is prepared by isotopic exchange with [{sup 123}I]Nal and is formulated in isotonic aqueous NaCl solution containing 1 mCi/ml iofetamine HCI I 123, 0.15 mg/ml iofetamine HCI carrier, and phosphate buffer for pH control. The radiochemical purity is >97%, and the product is stable for more than 24 hours; the commercial product distributed today is prepared with high purity {sup 123}I with >98% radionuclidic purity. Two radioiodinated agents have seen significant clinical application for functional brain imaging: iofetamine HCI (IMP) (1) and N,N,N{prime}-trimethyl-N{prime}-(2-hydroxy-3-methyl-5-iodobenzyl)-1,3-propanediamine HIPDM (2). lofetamine HCI {sup 123}I is commercially available in the United States, Europe, and Japan. Although their primary use is for functional brain imaging, ...
1991-12-31
Interaction of energetic beams with metals and semiconductors - a computational approach
International Nuclear Information System (INIS)
In a vacuum insulator, the narrow electron beam emitted from the cathode impinges on the anode and raises its temperature and also may produce high thermal stress. This high thermal stress, in conjuction with the surface electrostatic pressure may rupture the surface and detach particles from it. In this thesis, the interaction of high energy electron and laser beams with metals and semiconductors is investigated. The differential equations governing the physical processes involved in the interaction are solved by the finite element method. Effects of beam penetration into the material, variable beam reflectance at the surface, finite beam size and dependence of material properties on temperature are accounted for. The two-phase moving boundary problem, also known as the Stefan problem, is solved by an enthalpy formulation of the heat equation. Material deformation by thermal stresses caused by high temperature gradients and electrostatic forces induced by space ...
1984-01-01
Energy Technology Data Exchange (ETDEWEB)
This paper describes the comprehensive modeling method of fluid and heat flows in the hydrological system. Based upon the concept that the hydrological system is composed of the air-water 2-phase fluids, and the rock phase, various natural processes are modeled including surface/subsurface 2-phase mass transfer, heat exchanges between fluid phases, between fluid and solid phases, and sensible/latent heat exchanges on the ground surface. A field-oriented numerical simulator is developed, in which a set of governing equations is solved for different variables on the surface and in subsurface regions, respectively. Results of an experimental study are presented, in which transient formulation of heat exchange between fluid/solid phases is examined through matching of the observation and calculated performances. (author)
1999-08-31
Energy Technology Data Exchange (ETDEWEB)
This paper describes the comprehensive modeling method of fluid and heat flows in the hydrological system. Based upon the concept that the hydrological system is composed of the air-water 2-phase fluids, and the rock phase, various natural processes are modeled including surface/subsurface 2-phase mass transfer, heat exchanges between fluid phases, between fluid and solid phases, and sensible/latent heat exchanges on the ground surface. A field-oriented numerical simulator is developed, in which a set of governing equations is solved for different variables on the surface and in subsurface regions, respectively. Results of an experimental study are presented, in which transient formulation of heat exchange between fluid/solid phases is examined through matching of the observation and calculated performances. (author)
1999-08-31
Energy Technology Data Exchange (ETDEWEB)
Formulation is introduced for discretizing a boundary integral equation into an indirect boundary element method for the solution of 3-dimensional topographic problems. Yokoi and Takenaka propose an analytical solution-capable reference solution (solution for the half space elastic body with flat free surface) to problems of topographic response to seismic motion in a 2-dimensional in-plane field. That is to say, they propose a boundary integral equation capable of effectively suppressing the non-physical waves that emerge in the result of computation in the wake of the truncation of the discretized ground surface making use of the wave field in a semi-infinite elastic body with flat free surface. They apply the proposed boundary integral equation discretized into the indirect boundary element method to solve some examples, and succeed in proving its validity. In this report, the equation is expanded to deal with 3-dimensional topographic problems. A problem of a ...
1997-05-27
International Nuclear Information System (INIS)
LOCA (Loss of coolant accident) resistant heat-shrinkable polymeric products are widely used for the connection of LV cables for class 1E systems inside the containment area of nuclear power plants. The paper/presentation describes the verification of a reformulated compound for these products, where certain components of the compound formulation had to be substituted. A qualification programme with this so-called reformulated compound was undertaken to proof the equivalency of the products to the products made out of the original compound. The basic elements of this requalification project were material qualification tests including accelerated aging tests according to the arrhenius method and type tests in accordance to IEEE 383, including flammability tests. The test results showed that the products made out of the reformulated compound were similar in fit, form and function to the original products. Additional tests have also proven higher application ranges ...
2005-06-15
Energy Technology Data Exchange (ETDEWEB)
This paper describes the development of a computational multiphase fluid dynamics (CMFD) model of the Fischer Tropsch (FT) process in a Slurry Bubble Column Reactor (SBCR). The CMFD model is fundamentally based which allows it to be applied to different industrial processes and reactor geometries. The NPHASE CMFD solver [1] is used as the robust computational platform. Results from the CMFD model include gas distribution, species concentration profiles, and local temperatures within the SBCR. This type of model can provide valuable information for process design, operations and troubleshooting of FT plants. An ensemble-averaged, turbulent, multi-fluid solution algorithm for the multiphase, reacting flow with heat transfer was employed. Mechanistic models applicable to churn turbulent flow have been developed to provide a fundamentally based closure set for the equations. In this four-field model formulation, two of the fields are used to track the gas phase (i.e., ...
2008-11-01
Heavy-ion linear induction accelerators as drivers for inertial fusion power plants
Energy Technology Data Exchange (ETDEWEB)
A linear induction accelerator that produces a beam of energetic heavy ions (T -- 10 GeV, A -- 200 amu) is a prime candidate as a driver for an inertial fusion power plant. Some early perceptions were that heavy-ion drive fusion would not be cost-competitive with other power sources because of the high cost of the accelerators. However, improved understanding of the physics of heavy-ion transport and acceleration (supported by experimental results), combined with advances in accelerator technology, have resulted in accelerator design costs -- 50% of previous estimates. As a result, heavy-ion drive fusion power plants are now projected to be cost-competitive with other conceptual fusion power plants. A brief formulation of transport and acceleration physics is presented here, along with a description of the induction Linac cost optimization code LIACEP. Cost trends are presented and discussed, along with specific cost estimates for several accelerator designs ...
1988-02-01
Heavy-ion linear induction accelerators as drivers for inertial fusion power plants
International Nuclear Information System (INIS)
A linear induction accelerator that produces a beam of energetic heavy ions (T #approx =# 10 GeV, A #approx =# 200 am#mu#) is a prime candidate as a driver for an inertial fusion power plant. Some early perceptions were that heavy-ion driven fusion would not be cost-competitive with other power sources because of the high cost of the accelerators. However, improved understanding of the physics of heavy-ion transport and acceleration (supported by experimental results), combined with advances in accelerator technology, have resulted in accelerator design costs -- 50% of previous estimates. As a result, heavy-ion driven fusion power plants conceptual fusion power plants. A brief formulation of transport and acceleration physics is presented here, along with a description of the induction Linac cost optimization code LIACEP. Cost trends are presented and discussed, along with specific cost estimates for several accelerator designs matched to specific inertial fusion ...
Energy Technology Data Exchange (ETDEWEB)
First, attention is paid to the development and use of new construction techniques, including the use of new building materials, e.g. synthetic materials and the so-called steel frame method. Next, the reduction of the energy consumption during the service life of a house is discussed. The reduction can be realized by means of passive methods, e.g. improved windows, thermal insulation and design, or by means of active methods, e.g. electric load monitoring. The information in this article mainly concerns the housing construction in the USA and Canada. The purpose of this article to contribute to the discussion in the Netherlands on innovation in the building technology, e.g. formulated in the report `Bouwvisie 2010` (Vision on Buildings for the year 2010) of the Dutch Advisory Board Technology Policy for the Building Industry (ARTB, abbreviated in Dutch) and the building technology policy of the Dutch Ministry of Economic Affairs (EZ). 4 figs., 2 tabs., 23 refs.
1996-12-31
Gauge invariant perturbation theory in spatially homogeneous cosmology
International Nuclear Information System (INIS)
The perturbations of the L.R.S. class A spatially homogeneous spacetimes are treated using Hamiltonian methods in conjunction with techniques from the theory of Lie group harmonic analysis. These latter techniques lead to a simple way of handling any set of tensor equations on these background spacetimes which has the same symmetry group as the space-time metric. Once this approach is developed, the Hamiltonian formulation is used to recover in a clean way the Bonanos equations for the perturbations of the perfect fluid models of the class of spacetimes under consideration. The conserved quantities associated with the four-dimensional symmetry group are evaluated and their role in the linearized Hamiltonian dynamics is discussed. The time-dependent linear canonical transformation of the linearized vacuum gravitational phase space adapted to Moncrief's gauge invariant decomposition is described in general for these models and evaluated explicitly for a class of ...
Fuzzy-decision-making problems of fuel ethanol production using a genetically engineered yeast
Energy Technology Data Exchange (ETDEWEB)
A fuzzy-decision-making procedure is applied to find the optimal feed policy of a fed-batch fermentation process for fuel ethanol production using a genetically engineered Saccharomyces yeast 1400 (pLNH33). The policy consisted of feed flow rate, feed concentration, and fermentation time. The recombinant yeast 1400 (pLNH33) can utilize glucose and xylose simultaneously to produce ethanol. However, the parent yeast utilizes glucose only. A partially selective model is used to describe the kinetic behavior of the process. In this study, this partially selective fermentation process is formulated as a general multiple-objective optimal control problem. By using an assigned membership function for each of the objectives, the general multiple-objective optimization problem can be converted into a maximizing decision problem. In order to obtain a global solution, a hybrid method of differential evolution is introduced to solve the maximizing decision problem. A simple ...
1998-08-01
Energy Technology Data Exchange (ETDEWEB)
Deformation in the overburden proves useful in deducing spatial and temporal changes in the volume of a producing reservoir. Based upon these changes we estimate diffusive travel times associated with the transient flow due to production, and then, as the solution of a linear inverse problem, the effective permeability of the reservoir. An advantage an approach based upon travel times, as opposed to one based upon the amplitude of surface deformation, is that it is much less sensitive to the exact geomechanical properties of the reservoir and overburden. Inequalities constrain the inversion, under the assumption that the fluid production only results in pore volume decreases within the reservoir. We apply the formulation to satellite-based estimates of deformation in the material overlying a thin gas production zone at the Krechba field in Algeria. The peak displacement after three years of gas production is approximately 0.5 cm, overlying the eastern margin of the ...
2010-04-01
Fluid mixing in reactor containment
Energy Technology Data Exchange (ETDEWEB)
Full text of publication follows: Hydrogen release and distribution in nuclear power plant containment is an important safety issue. Selection of a proper turbulence model is important for accurate estimation of the mixing process. The selection of turbulence model is dictated by the best compromise between accuracy and computational efforts. For this, three different turbulence models, viz. Standard k-{epsilon}, RNG k-{epsilon} and Reynolds Stress Model, based on Reynolds averaged Navier Stokes equations (RANS) approach, were used. The computations were done using the CFD code FLUENT, which is based on the control volume methodology. The computational results were compared with the experimental results of HYMIS test facility, where helium was used to simulate hydrogen. The processes of helium plume rise, multiple plume merging, distribution and mixing were studied. Based on these computations, a simple analytical/empirical zone based model was formulated for the ...
2005-07-01
Fluid mixing in reactor containment
International Nuclear Information System (INIS)
Full text of publication follows: Hydrogen release and distribution in nuclear power plant containment is an important safety issue. Selection of a proper turbulence model is important for accurate estimation of the mixing process. The selection of turbulence model is dictated by the best compromise between accuracy and computational efforts. For this, three different turbulence models, viz. Standard k-#epsilon#, RNG k-#epsilon# and Reynolds Stress Model, based on Reynolds averaged Navier Stokes equations (RANS) approach, were used. The computations were done using the CFD code FLUENT, which is based on the control volume methodology. The computational results were compared with the experimental results of HYMIS test facility, where helium was used to simulate hydrogen. The processes of helium plume rise, multiple plume merging, distribution and mixing were studied. Based on these computations, a simple analytical/empirical zone based model was formulated for the ...
2005-10-02
The Bingham plastic constitutive model has been widely used to predict the post-yield behavior of electro- and magneto- rheological fluids (ER and MR fluids). However, if these fluids experience shear thinning or shear thickening, the Bingham plastic model may not be an accurate predictor of behavior, since the post-yield plastic viscosity is assumed to be constant. In a recent study, it was theoretically and experimentally demonstrated that the Herschel-Bulkley fluid model can be successfully employed when evaluating non- Newtonian post-yield behavior of ER and MR fluids. In this paper, the Herschel-Bulkley model is employed to include a detailed analysis of ER and MR fluid dynamics through pipes and parallel plates. Simplified explicit expressions for the exact formulation are also developed. It is shown that the proposed simplified model of the Herschel-Bulkley steady flow equations for pipes and parallel plates can be used as an accurate design tool while ...
2000-04-01
Feynman-like Rules for Calculating n-Point Correlators of the Primordial Curvature Perturbation
A diagrammatic approach to calculate n-point correlators of the primordial curvature perturbation \\zeta was developed a few years ago following the spirit of the Feynman rules in Quantum Field Theory. The methodology is very useful and time-saving, as it is for the case of the Feynman rules in the particle physics context, but, unfortunately, is not very well known by the cosmology community. In the present work, we extend such an approach in order to include not only scalar field perturbations as the generators of \\zeta, but also vector field perturbations. The purpose is twofold: first, we would like the diagrammatic approach (which we would call the Feynman-like rules) to become widespread among the cosmology community; second, we intend to give an easy tool to formulate any correlator of \\zeta for those cases that involve vector field perturbations and that, therefore, may generate prolonged stages of anisotropic expansion and/or important levels of ...
2011-01-01
Federated sigma point filter for multi-sensor attitude and rate estimation of spacecraft
High precision, fast computation speed, as well as a good capability of fault tolerant and reconstruction are required more and more for spacecraft attitude determination system. To realize the above requirement, an approach was presented to the synthesis of federated filters using sigma point technique. In this algorithm, the sigma point technique brought the algorithm a high precision, while the federated structure significantly enhanced the filters' capability of multi-rate information fusion, fault tolerance, and system modularity. Within consideration of computation consumption, a simple information-sharing formulation was derived to adapt to the special property of sigma point distribution, and a dynamical information sharing strategy for multi-rate fusion was developed. A numerical simulation example was employed to give the algorithm a test, where the simulated system contained a suit of gyroscopes; a three-axis magnetometer and a sun sensor each had a ...
2008-11-01
Faster Approximate Lossy Generalized Flow via Interior Point Algorithms
We present faster approximation algorithms for generalized network flow problems. A generalized flow is one in which the flow out of an edge differs from the flow into the edge by a constant factor. We limit ourselves to the lossy case, when these factors are at most 1. Our algorithm uses a standard interior-point algorithm to solve a linear program formulation of the network flow problem. The system of linear equations that arises at each step of the interior-point algorithm takes the form of a symmetric M-matrix. We present an algorithm for solving such systems in nearly linear time. The algorithm relies on the Spielman-Teng nearly linear time algorithm for solving linear systems in diagonally-dominant matrices. For a graph with m edges, our algorithm obtains an additive epsilon approximation of the maximum generalized flow and minimum cost generalized flow in time tildeO(m^(3/2) * log(1/epsilon)). In many parameter ranges, this improves over previous algorithms ...
2008-01-01
Exploring Neutrino Mixing with Low Energy Superbeams
We explore as clearly as possible the features of neutrino oscillation which are relevant for measurements of the CP violating Kobayashi-Maskawa phase delta and the sign of \\Delta m^2_{13}. We focus on the so called low-energy option and discuss principles for optimizing experimental parameters to measure these two quantities simultaneously. Toward the goal, we first formulate a method for obtaining a bird-eye view of the phenomenon of neutrino oscillation by introducing a new powerful tool called the ``CP trajectory diagram in bi-probability space''. It allows us to represent pictorially the three effects separately in a single diagram; effect from genuine CP violation due to the sin delta term, effect from the CP conserving cos delta term, and the fake CP violating effect due to earth matter. By using the CP trajectory diagram we observe that there is a two-fold ambiguity in the determination of delta which is related with the sign of Delta m^2_{13}. We then ...
2001-01-01
Evaluation of a stack: A concrete chimney with brick liner
Energy Technology Data Exchange (ETDEWEB)
A 200 ft. tall stack, consisting of a concrete chimney with an independent acid proof brick liner built in the 1950`s, serving the Separations facility at the Savannah River Site (SRS), was evaluated for the performance category 3 (PC3) level of Natural Phenomena Hazards (NPH) effects. The inelastic energy absorption capacity of the concrete chimney was considered in the evaluation of the earthquake resistance, in particular, to compute the F{sub {mu}} factor. The calculated value of F{sub {mu}} exceeded 3.0, while the seismic demand for the PC3 level, using an F{sub {mu}} value of 1.5, was found to be less than the capacity of the concrete chimney. The capacity formulation of ACI 307 was modified to incorporate the effect of an after design opening on the tension side. There are considerable uncertainties in determining the earthquake resistance of the independent brick liner. The critical liner section, located at the bottom of the breeching opening, does not ...
1995-12-31
Enhancing compressive response of AZ31B using nano-Al2O3 and copper additions
British Library Electronic Table of Contents (United Kingdom)
In the present study, new light weight nano-composites (AZ31B-3.3Al2O3-Cu) based on magnesium alloy AZ31B are developed using disintegrated melt deposition technique. Microstructural characterization studies revealed grain refinement and significant increase in amount of second phases as a result of increasing presence of copper. All the samples exhibited minimal porosity and good matrix-second phase interfacial integrity. The results also showed that addition of both nano-Al2O3 and Cu led to a simultaneous improvement in 0.2% yield compressive strength (0.2%YCS), ultimate compressive strength (UCS) and work of fracture (WoF) of the AZ31B magnesium alloy while failure strain was marginally affected. The results of this study clearly illustrate the capability of AZ31B-Al2O3-Cu formulations ...
2010-01-01
Energy Technology Data Exchange (ETDEWEB)
An analysis is given of the problems which can be solved by the use of electric-powered vehicles. A detailed comparison is made of the energy consumption and the air polluting emissions of electric and conventional vehicles, taking into account the energy consumption of the vehicles and the primary energy consumption of electric power generation and automotive fuels production. Also the air pollution, as a result of power generation and fuel production are considered. In chapter 1 an outline is given of the traffic and transportation sector in the Netherlands with special attention to data on the energy consumption and the air pollution of this sector. Based on these data the problems can be formulated for which the application of electric vehicles can be a solution. In chapter three a brief description is given of the technical specifications and characteristics of electric vehicles. Special attention is paid to the battery types. The energy and environmental ...
1992-09-01
International Nuclear Information System (INIS)
The genetically significant dose (GSD) is an index variable which exclusively allows to describe the genetic risk in the progeny of a population due to the application of ionizing radiation and radioactive substances in one part of this population. It may result in wrong interpretation of population exposure at increasing incidence of examinations in a population involving ionizing radiation and radioactive drugs at simultaneously increasing application of alternative methods in children and adolescents owing to the fact that it indicates a downward trend although somatic exposure of this population has increased. Therefore, it is recommended to state both the GSD and the level of somatic radiation exposure of the population taken from the individual sources for the comparison and assessment of radiation exposure from various sources in future. Although the somatically significant dose constitutes the suitable variable complementary to GSD in thus context, it is recommended to select ...
1984-06-01
Effective Dynamics, Big Bounces and Scaling Symmetry in Bianchi Type I Loop Quantum Cosmology
The detailed formulation for loop quantum cosmology (LQC) in the Bianchi I model with a scalar massless field has been constructed. In this paper, its effective dynamics is studied in two improved strategies for implementing the LQC discreteness corrections. Both schemes show that the big bang is replaced by the big bounces, which take place up to three times, once in each diagonal direction, when the area or volume scale factor approaches the critical values in the Planck regime measured by the reference of the scalar field momentum. These two strategies give different evolutions: In one scheme, the effective dynamics is independent of the choice of the finite sized cell prescribed to make Hamiltonian finite; in the other, the effective dynamics reacts to the macroscopic scales introduced by the boundary conditions. Both schemes reveal interesting symmetries of scaling, which are reminiscent of the relational interpretation of quantum mechanics and also suggest ...
2007-01-01
Dissipation and entropy production in open quantum systems
Energy Technology Data Exchange (ETDEWEB)
A microscopic description of an open system is generally expressed by the Hamiltonian of the form: H{sub tot} = H{sub sys} + H{sub environ} + H{sub sys-environ}. We developed a microscopic theory of entropy and derived a general formula, so-called 'entropy-Hamiltonian relation' (EHR), that connects the entropy of the system to the interaction Hamiltonian represented by H{sub sys-environ} for a nonequilibrium open quantum system. To derive the EHR formula, we mapped the open quantum system to the representation space of the Liouville-space formulation or thermo field dynamics (TFD), and thus worked on the representation space L := H x H-tilde, where H denotes the ordinary Hilbert space while H-tilde the tilde Hilbert space conjugates to H. We show that the natural transformation (mapping) of nonequilibrium open quantum systems is accomplished within the theoretical structure of TFD. By using the obtained EHR formula, we also derived the equation of ...
2010-11-01
Diagnosing mechanical changes: A test of the machine condition monitoring concept
Energy Technology Data Exchange (ETDEWEB)
BC Hydro recently conducted a demonstration test of a bearing condition monitor. The test, at the 529-MW Kootenay Canal project, proved the ability of the monitor to detect machine condition faults. The capability to detect changing conditions during normal operation of hydroelectric machines gives hydro plant owners the opportunity to anticipate needed maintenance and ultimately to reduce the number of equipment failures. BC Hydro intends to install bearing condition monitors, as well as windings monitors, brushgear monitors, environmental monitors, and other selected systems in as many as 46 of its hydro generators. BC Hydro analyzed forced outages between 1985 and 1989 in its hydro system to identify which parts of a generating unit resulted in the highest number of hours of outage. From there, the utility has formulated a concept for a machine condition monitoring system. To keep the system cost effective, it will be developed in modules. In this way, users can ...
1993-05-01
Development and field application of a leak sealant for the NRU water reflector
International Nuclear Information System (INIS)
The development and successful application of a unique leak sealant formulation comprised of a mixture of graded, hollow ceramic microspheres, surface oxidized aluminum powder and saturated gibbsite suspension is described. The project was undertaken to address the escalating leakage from up to 15 small weld defects in the water reflector vessel, an integral component of the NRU (National Research Universal) reactor calandria. The reflector surrounds the reactor core with a neutron reflecting blanket of light water. Injection of the sealant is typically done with the reactor shutdown and the water reflector system operating normally, but can also be performed with the reactor at full power. The procedure is simple and effective. Individual treatments of as little as 125 ml of sealant (10 ppm in the 12,500 L system) have yielded leak reductions exceeding 2000 L/day. The accumulated leak reductions of several treatments now total 90% of the historic high of 5,400 ...
2001-06-10
Energy Technology Data Exchange (ETDEWEB)
Crystallography and computer modeling have been used to exploit a previously unexplored channel in the glucocorticoid receptor (GR). Highly potent, nonsteroidal indazole amides showing excellent complementarity to the channel were designed with the assistance of the computational technique AlleGrow. The accuracy of the design process was demonstrated through crystallographic structural determination of the GR ligand-binding domain-agonist complex of the D-prolinamide derivative 11. The utility of the channel was further exemplified through the design of a potent phenylindazole in which structural motifs, seen to interact with the traditional GR ligand pocket, were abandoned and replaced by interactions within the new channel. Occupation of the channel was confirmed with a second GR crystal structure of this truncated D-alaninamide derivative 13. Compound 11 displays properties compatible with development as an intranasal solution formulation, whereas oral ...
2010-09-17
Deposit formation tendency of lubricants at high temperatures
Energy Technology Data Exchange (ETDEWEB)
A thin film microoxidation test utilizing the concept of the Lubricant Stability Map has been used to study the effect of temperature on deposit formation by lubricants on upper piston locations of low heat rejection engines. The stability maps were established for two formulated lubricants in this study. These two lubricants were also evaluated in a series of engine tests with various piston temperatures. The deposition phenomena observed in the engine tests have been adequately simulated and described by the stability maps. It is concluded that lubricants at upper piston locations are under a thin film condition similar to that achieved by the thin film microoxidation test. The deposit formation trend is determined by the volatility, thermal stability, and oxidative stability of the base stock. Additives have little effect on deposit formation at very high temperatures. A combined consideration of all competing reaction pathways at a specific temperature of ...
1995-05-01
Decontamination of a gas cooler using foams containing chemical reagents
Energy Technology Data Exchange (ETDEWEB)
This paper deals with an industrial application of the foam decontamination process applied to large volume components. The work presented below was achieved within the context of a CEC contract. The objective of this 4-year programme was to study, develop and demonstrate an effective in-situ decontamination process using foams containing suitable chemical reagents. Laboratory tests were first performed to optimize the chemical formulation of the foams. Pilot tests were then conducted to study the hydrodynamic features of the fluids and to adapt a technique of permanent foam circulation. With these tests completed, it was essential to validate the foam process on an industrial scale and on a representative nuclear component. The objective was successfully achieved. The process was effectively validated during the decontamination of a graphite-gas cooler representing a developed area of 1000 m{sup 2}. Results were quite convincing since the residual activity of the ...
1994-12-31
Crud removal performance with ion exchange resins in BWR plants
Energy Technology Data Exchange (ETDEWEB)
It is needless to say that one of the most important roles of the condensate demineralizer in Japanese boiling water reactors (BWR) is to eliminate such impurities during accidental occurrence of sea water leakage from condensate cooling system. Ion exchange resins packed in condensate demineralizer have also been expected to decrease crud, or corrosion products (CP) in condensate water in order to finally reduce activated corrosion products (ACP) in the reactor coolant loop. It is perceived that crud removal ability of a condensate demineralizer has been improved year by year. And we call this phenomenon as `Aging Effect`. Typical property changes of aged cation exchange resin consisted of an increase of water retention capacity and a change of surface texture. Based on these findings, we formulated a new concept and developed new gel type ion exchange resins for the better crud removal. The results from column tests using actual condensate water for approximately ...
1996-01-01
Energy Technology Data Exchange (ETDEWEB)
Ontario's Countdown Acid Rain program was formulated in 1985 and placed an annual SO{sub 2} emissions cap of 885 kilotonnes over the province from 1994. Caps were placed on emissions from the Inco nickel/copper smelter in Sudbury, the Falconbridge nickel/copper smelter in Sudbury, the Algoma iron ore sintering plant in Wawa, and Ontario Hydro fossil-fuel plants province-wide. Semi-annual reports are required of the companies, with the 6th report outlining the final planning phase and the 7th and later reports outlining implementation progress. This document summarizes the contents of the 7th set of reports and the responses of the government review team to each company's efforts. All companies have begun implementing abatement plans outlined in the final planning phase reports of December 1988 at a rapid pace and are generally on track in controlling emissions. However, all 4 company reports lack the necessary detail for a complete review of the ...
1990-01-01
Coulomb gauge QCD as a tool for the excited spectrum
A distinct feature of Coulomb gauge QCD is that it can be formulated in terms of physical, transverse gluons and quarks alone. The state-counting is then transparent, and the gauge is suited for studies of the excited spectrum. Leaving aside exotic spectroscopy, which has been the subject of other publications, in this note I call attention on two recent applications. One is that the running quark mass in the mid-infrared can be probed from excited baryons thanks to parity doubling, a consequence of insensitivity to chiral symmetry breaking. Fast quarks are asymptotically free and behave as massless, so hadrons containing fast quarks decouple from the condensate. Their (power-law) rate of decoupling reflects on the rate of decreasing parity splittings, which can be measured. The second is that, in analogy with the Franck-Condon principle of molecular physics, the velocity distribution of the heavy quarks inside a heavy hadron can be mapped out by the velocity ...
2010-01-01
Cooperative procurement: market transformation for energy efficient products
Energy Technology Data Exchange (ETDEWEB)
Cooperative procurement is a variation of public purchasing which may be used as an instrument to transform the market and stimulate innovation enhancing environmental performance. The core of the procedure is the following: Coordinated by a central agency a group of buyers - public administrations, but also private companies, associations, etc. - gets together and jointly formulates a catalogue of performance requirements for a specific product truly suiting their preferences. This catalogue may contain (combinations of) requirements not yet available on the market and includes energy efficiency and/or environmental performance among other preferences important to the users. On the basis of the product requirements the buyer group launches a call for tenders, evaluates the bids received from the manufacturers and commits to buying the winning product. Thus, a market is provided for the most successful innovators in a given area of technology. The paper discusses ...
1999-07-01
Computer assisted axial tomography (Emi scan) in neurologic investigation
Cerebral angiography, pneumoencephalography, and radioisotope brain scan with their differing diagnostic abilities have provided the neurologist and neurosurgeon with extremely valuable diagnostic techniques. It is doubtful, however, if any of these now conventional methods had the enormous impact on the practice of neurology that computer assisted axial tomography (C.A.T.) is beginning to have. Here, for the first time, is a test which, without significant risk or discomfort, can demonstrate some normal intracranial (and intraorbital) structures, can demonstrate some normal intracranial pathology and, in many cases, can make the potentially dangerous contrast studies unnecessary. After only a few months experience with C.A.T. in a clinical setting, it has become obvious that there will have to be a reappraisal of the accepted investigative work-up of many conditions. While it is too early to have formulated strict criteria for the use of C.A.T., this paper is an ...
1974-01-01
Composites from recycled wood and plastics. Report for May 1990-July 1993
Energy Technology Data Exchange (ETDEWEB)
The ultimate goal of this research was to develop technology to convert recycled wood fiber and plastics into durable products that are recyclable and otherwise environmentally friendly. Two processing technologies were used to prepare wood-plastic composites: air-laying and melt-blending. Research was conducted in (1) developing laboratory methods for converting waste wood, wastepaper, and waste plastics into forms suitable for processing into composites; (2) optimizing laboratory methods for making composite panels from the waste materials; (3) establishing a database on the effects of formulation and bonding agent on physical and mechanical properties of composites; (4) establishing the extent to which the composites can be recycled without unacceptable loss in properties; and (5) reaching out to industry to provide education, to develop applications, and to extend the database. Overall, the program demonstrated that both air-laid and melt-blended composites can ...
1995-01-01
Energy Technology Data Exchange (ETDEWEB)
Power system operating conditions vary with system configurations and loading conditions. Coefficients in nominal system model change in a complex manner with different operating point and so does system dynamic behavior. With the aid of unstructured and structured uncertainty descriptions, the worst system variations can be estimated and formulated into two different uncertainty models in frequency domain; multiplicative unstructured uncertainty in the form of transfer function and structured uncertainty with the parametric uncertainty description. The uncertainty descriptions are then incorporated into system nominal model to perform H{sub {infinity}} and {mu} based robust power system stabilizer (PSS) design. Both approaches to the PSS design enable the power system to remain stable over a wide range of system operating conditions but the different performance can be observed due to the inheritance of the ways to handle the system uncertainty. 8 refs, 8 figs, 1 ...
1995-11-01
Community Detection using a Measure of Global Influence
The growing popularity of online social networks has provided researchers with access to large amount of social network data. This, coupled with the ever increasing computation speed, storage capacity and data mining capabilities, led to the renewal of interest in automatic community detection methods. Surprisingly, there is no universally accepted definition of the community. One frequently used definition states that ``communities, that have more and/or better-connected `internal edges' connecting members of the set than `cut edges' connecting the set to the rest of the world''[Leskovec et al. 20008]. This definition inspired the modularity-maximization class of community detection algorithms, which look for regions of the network that have higher than expected density of edges within them. We introduce an alternative definition which states that a community is composed of individuals who have more influence on others within the community than on those outside of it. We present a ...
2008-01-01
Chemical imaging of wood-polypropylene composites.
Recent investigations of wood plastic composites have revealed a detrimental effect of using lubricant systems in production. This includes nullifying part or all of the mechanical benefit of using a polar compatibilizer, maleic anhydride polypropylene (MAPP), in the composite formulation. This investigation utilizes lubricants labeled with deuterium in conjunction with Fourier transform infrared (FT-IR) spectroscopy to allow for the separation of individual lubricants from all other material constituents. All of the deuterium labeled lubricants, used without MAPP, revealed their expulsion from the wood interface during crystallization. MAPP coupling agent was found to exist near the wood, but it is unclear if any covalent bonding with the hydroxyl functionality on the wood surface occurred. The addition of zinc stearate lubricants appears to nullify the activity of the anhydride functionality near the wood surface as evidenced by a shift in the FT-IR spectra to ...
2006-08-01
CAA broadband noise prediction for aeroacoustic design
The current status of a computational aeroacoustics (CAA) approach to simulate broadband noise is reviewed. The method rests on the use of steady Reynolds averaged Navier-Stokes (RANS) simulation to describe the time-averaged motion of turbulent flow. By means of synthetic turbulence the steady one-point statistics (e.g. turbulence kinetic energy) and turbulent length- and time-scales of RANS are translated into fluctuations having statistics that very accurately reproduce the initial RANS target-setting. The synthetic fluctuations are used to prescribe sound sources which drive linear perturbation equations. The whole approach represents a methodology to solve statistical noise theory with state-of-the-art CAA tools in the time-domain. A brief overview of the synthetic turbulence model and its numerical discretization in terms of the random particle-mesh (RPM) and fast random particle-mesh (FRPM) method is given. Results are presented for trailing-edge noise, slat noise, and jet ...
2011-08-01
British Library Electronic Table of Contents (United Kingdom)
Abstract Coordination compounds [Ru(acac)2(Q)] (acac=acetylacetonate; Q=o-benzoquinone) were prepared as complexes 1 (Q=o-benzoquinone), 2 (Q=3-methoxy-o-benzoquinone), 3 (Q=4-methyl-o-benzoquinone), and 4 (Q=3,5-di-tert-butyl-o-benzoquinone). The structures of 1 and 2 were determined to reveal a RuIII/o-benzosemiquinone formulation, supported by analysis of experimental data (spectroscopy, magnetism of 1) and by DFT calculations. The S=1 ground state calculated for 1 stands in contrast to the spin-paired analogues with arylimino-o-benzosemiquinonato and diimino-o-benzoquinone ligands. The close contacts of about 5.3- possible between semiquinone O atoms of different molecules in the crystal allow for intermolecular spin-spin interactions and an overall complex magnetic behavior. One quasi...
2011-01-01
Beam pattern diagnosis and adjustment guidance for cyclotron based on fuzzy relation
Energy Technology Data Exchange (ETDEWEB)
An adjustment support system using computer for start-up operation of cyclotron is being developed in order to support operators who, using their experiences and intuition, tune up dozens of components to maximize beam efficiency. This paper describes a method of beam pattern diagnosis and adjustment guidance based on fuzzy relation as one function of the adjustment support system. The followings are the basic processes of this method. (1) The computer extracts features of beam pattern which correspond with operators' criteria. (2) The computer calculates causative possibility of each adjustment parameters by inverse operation of fuzzy relational equation, which formulates the relationship between criteria of beam pattern and adjustment parameters. (3) The computer displays those causative probabilities in a graphical manner as a operation guidance. Not only the probabilities but also the criteria of beam pattern and their relationship are displayed in one ...
1990-08-01
BNFL Report Glass Formers Characterization
Energy Technology Data Exchange (ETDEWEB)
The objective of this task was to obtain powder property data on candidate glass former materials, sufficient to guide conceptual design and estimate the cost of glass former handling facilities as requested under Part B1 of BNFL Technical and Development Support. Twenty-nine glass forming materials were selected and obtained from vendors for the characterization of their physical properties, durability in caustic solution, and powder flow characteristics. A glass former was selected based on the characterization for each of the ten oxide classes required for Envelope A, B, and C mixtures. Three blends (A, B, and C) were prepared based on formulations provided by Vitreous State Laboratory and evaluated with the same methods employed for the glass formers. The properties obtained are presented in a series of attached Tables. It was determined that five of the ten glass formers, (kyanite, iron oxide, titania, zircon, and zinc oxide) have the potential to cause some ...
2000-07-27
Energy Technology Data Exchange (ETDEWEB)
The purpose of this study is to identify the radiative heat transfer augmentation by a coaxial cylinder introduced in the infinite cylindrical pipe enclosing a participating gas. The gas is either a mixture of water vapor and carbon dioxide or gray. The gas is assumed to be homogeneous at a constant temperature, and has a refractive index of unity. All of the surfaces are opaque and gray, diffusely emitting and reflecting at a constant temperature. The effect of system diameter, diameter ratio, wall emittances, gas and surface temperatures, mixture component on heat transfer augmentation are studied by using the zone method with participating gas radiative properties evaluated from the weighted sum of gray gases model. From the radiative equilibrium condition, the installed wall temperature is formulated and calculated by the iteration method. If the medium is a gray gas, the augmentation observed are negligible. For the range of values studied for a real gas, if ...
1992-10-01
Asymptotic numbers and wave packets
International Nuclear Information System (INIS)
An attempt is made to generalize the spaces of numbers and functions in order to consider certain problems in quantum mechanics, especially in the cases, where wave functions appear which do not belong to the Hilbert space L"2. Often the Soboljev - Schwartz distributions are used but they are not always the appropriate tool because they cannot be multiplied. A modification of the definition of generalized functions PSI(x vector) is proposed by particular conditions. Such conditions imposed on the wave function of a free particle seems to be the most natural by means of physics. It appears, however, that for all spaces with a real norm these conditions are contradictory. This implies together with the extension of the space of functions, an extension of the space of numbers with so called asymptotic numbers A. The four algebraic operations - addition, subtraction, multiplication and division are defined in the set A. To avoid the contradictions between the conditions it is necessary to ...
1976-01-26
Application of variational methods to fusion reactor blanket studies
International Nuclear Information System (INIS)
The general development of variational methods for fusion reactor blanket studies is given. Important quantities such as tritium breeding ratio and total nuclear heating are linear functionals of the solutions to the Boltzmann transport equation. To estimate a neutronic quantity by variational methods is, in general, to carry out the scalar product formulation of the Roussopoulos variational principle, or the Schwinger variational principle, with the help of the associated adjoint transport equation where the appropriate response function for the estimate is taken as the source. A multipoint interpolation method based on the above variational principles has been developed and compared to other variational approaches. The method of variational interpolation removes the need to compute both forward and adjoint solutions while the error has the characteristic of cancellation of errors between interpolation reference points. Finally, the practical computational ...
British Library Electronic Table of Contents (United Kingdom)
Empty palm fruit bunch fiber (EPFBF), a readily available cellulosic biomass from palm processing facilities, is investigated as a potential carbohydrate source for cellulosic ethanol production. This feedstock was pretreated using ammonia fiber expansion (AFEX) and enzymatically hydrolyzed. The best tested AFEX conditions were at 135??C, 45?min retention time, water to dry biomass loading of 1:1 (weight ratio), and ammonia to dry biomass loading of 1:1 (weight ratio). The particle size of the pretreated biomass was reduced post-AFEX. The optimized enzyme formulation consists of Accellerase (84??L/g biomass), Multifect Xylanase (31??L/g biomass), and Multifect Pectinase (24??L/g biomass). This mixture achieved close to 90% of the total maximum yield within 72?h of enzymatic hydrolysis. Fer...
2010-01-01
Aeroelastic Analysis of Rotor Blades Using Cfd/csd Coupling in Hover Mode
A computational fluid dynamics (CFD) is coupled with a computational structural dynamics (CSD) to simulate the unsteady rotor flow with aeroelasticity effects. An unstructured upwind Navier-Stokes solver was developed for this simulation, with 2nd order time-accurate dual-time stepping method for temporal discretization and low Mach number preconditioning method. For turbulent flows, both the Spalart-Allmaras and Menter's SST model are available. Mesh deformation is achieved through a fast dynamic grid method called Delaunay graph map method for unsteady flow simulation. The rotor blades are modeled as Hodges & Dowell's nonlinear beams coupled flap-lag-torsion. The rotorcraft computational structural dynamics code employs the 15-dof beam finite element formulation for modeling. The structure code was validated by comparing the natural frequencies of a rotor model with UMARC. The flow and structure codes are coupled tightly with information exchange several ...
2010-01-01
Aerocapacitor commercialization plan
Energy Technology Data Exchange (ETDEWEB)
The purpose of the Power-One Aerocapacitor Commercialization Plan is to communicate to members of management and to all employees the overall objectives of the corporation. Power-One, Inc., has participated in a US Federal Government Technology Reinvestment Project (TRP), entitled {open_quotes}Advanced Power Conversion based on the Aerocapacitor{close_quotes}: the project is a group effort, with Lawrence Livermore National Labs, GenCorp/Aerojet, PolyStor Corp. (a start-up company), and Power-One forming the consortium. The expected resulting technology is the {open_quotes}Aerocapacitor{close_quotes}, which possesses much higher performance levels than the usual capacitors on the market today. Power-One hopes to incorporate the Aerocapacitor into some of its products, hence enhancing their performance, as well as market privately-labeled aerocapacitors through its distribution channels. This document describes the details of Power-One`s plan to bring to market and commercialize the ...
1995-09-12
Energy Technology Data Exchange (ETDEWEB)
We develop a general framework for the formulation of the action principle and the noether theorem for classical noncommutative field theories. We give a concrete example of an algebra that fits into this framework. It describes a scalar field theory on noncommutative minkowski space. We develop a notion of locality for this algebra and investigate the locality properties of localised interaction terms. This leads us to the definition of local functionals on the field algebra. We propose a scheme for the quantisation of these functionals. (orig.) [German] Wir entwickeln eine allgemeinen rahmen, der es erlaubt, das wirkungsprinzip und das noether-theorem fuer klassische nichtkommutative feldtheorien zu formulieren. Als ein konkretes beispiel betrachten wir eine algebra, die sich in diesem rahmen einfuegt, und die eine skalare feldtheorie auf dem nichtkommutativen minkowski-raum beschreibt. Fuer diese algebra wird ein lokalitaetsbegriff entwickelt und untersucht, ...
2003-12-01
Acoustic cloaking and transformation acoustics
International Nuclear Information System (INIS)
In this review, we give a brief introduction to the application of the new technique of transformation acoustics, which draws on a correspondence between coordinate transformation and material properties. The technique is formulated for both acoustic waves and linear liquid surface waves. Some interesting conceptual devices can be designed for manipulating acoustic waves. For example, we can design acoustic cloaks that make an object invisible to acoustic waves, and the cloak can either encompass or lie outside the object to be concealed. Transformation acoustics, as an analog of transformation optics, can go beyond invisibility cloaking. As an illustration for manipulating linear liquid surface waves, we show that a liquid wave rotator can be designed and fabricated to rotate the wave front. The acoustic transformation media require acoustic materials which are anisotropic and inhomogeneous. Such materials are difficult to find in nature. However, composite ...
2010-03-24
A novel high temperature stable lithium salt (Li{sub 2}B{sub 12}F{sub 12}) for lithium ion batteries
Energy Technology Data Exchange (ETDEWEB)
Basic properties and battery performances of the novel high temperature stable lithium salt (Li{sub 2}B{sub 12}F{sub 12}, Dilithium Dodecafluorododecaborate; Li{sub 2}DFB) were studied using a Mn-based cathode and anode composed of a hard carbon and graphite mixture. The effect of co-solvents (mainly linear carbonate in electrolyte formulation of PC/EC/co-solvent (5/30/65 vol% mixture)) on conductivity, viscosity, charge-discharge capacities, rate performance, temperature performance, cycle life and storage life at 60 C was investigated. Conductivity of Li{sub 2}DFB electrolyte increased with reducing its viscosity by changing co-solvent and increasing the volume of the higher dielectric solvent. Li{sub 2}DFB electrolytes showed comparable discharge capacity and columbic efficiency against LiPF{sub 6} electrolyte. Li{sub 2}DFB electrolytes improved the storage life and cycle life of a Mn-based cell at 60 C. (author)
2009-09-05
A model of coherent fluctuations of nuclear density
International Nuclear Information System (INIS)
A model for coherent fluctuations of the nuclear density including all nucleons in the fluctuation movement is formulated. The wave function of the flucton satisfies a Schroedinger-type equation in which the role of potential energy is played by the energy of the nuclear matter for the A nucleons. The appearance of high-momentum components in the one-particle momentum distribution is related to the volume fluctuations of the density. These fluctuations are supposed to be of coherent nature, i.e. all nucleons are involved in the motion. An explicit expression for the momentum distribution of the nucleons in "1"2C and "1"8"1Ta nuclei is obtained and compared with the phenomenological momentum distribution as well as with the results given by the model of a non-relativistic harmonic oscillator and by the Dirac equation in the self-consistent model. The differential cross-section of 1 GeV proton scattering by the "2"8Si, "3"2S, "4"0Ca, "4"8Ca, "5"8Ni, "2"0"8Pb are ...
Energy Technology Data Exchange (ETDEWEB)
The possibility of improving the cold formability of wrought magnesium alloys is considered in light of their good hot forming characteristics. Magnesium alloy AZ31B sheet is selected as a model system. Parameters affecting formability, such as strain hardening rate, strain rate sensitivity, and the degree of anisotropy are examined systematically by conducting tensile tests over a range of temperatures (room temperature to 250 C) and strain rates (1 x 10{sup -5} to 0.1 s{sup -1}). The plastic anisotropy and deformation texture evolution are examined in samples aligned with the sheet rolling and transverse directions. Polycrystal plasticity simulations using a viscoplastic self-consistent (VPSC) formulation are used to model the observed anisotropy and texture evolution. The adjustable parameters in the model are the relative critical resolved shear stresses of the dislocation mechanisms known to operate within magnesium. The experimental results suggest that an ...
2003-07-01
A market power model with price caps and compact DC power flow constraints
International Nuclear Information System (INIS)
This paper presents a spatial gaming model with price caps for deregulated electricity markets. There has been heated debate on price caps that have been enforced in deregulated electricity markets. Opponents argue that price caps may send wrong economic signals while advocates argue that price caps are good for damping market power. This paper does not intend to take a stand in the argument. Given the fact that price caps are enforced in several deregulated regional electricity markets in the US, a logical step is to reflect this reality in gaining modeling. However, current gaining models have not included any price cap formulation. This paper is the first one to address the issue. DC power flow equations are used for representing the spatial nature of an electrical network. An algorithm is proposed to find a generalized Nash equilibrium under the enforcement of price caps based on the Kuhn-Tucker Vector Optimization Theorem. Case studies show the successful ...
2003-05-01
Energy Technology Data Exchange (ETDEWEB)
IMRT with inverse planning allows simultaneous integrated boost strategies that exploit the heterogeneous dose distribution within the planning target volumes (PTVs). In this scenario, the location of cold spots within the target becomes a crucial issue and has to be related to the distribution of the clonogenic cell density (CCD). The main aim of this work is to provide the means to calculate the optimal prescription dose in a relative inhomogeneous dose distribution. To achieve this, the prescription dose has to be assigned to obtain the same tumor control probability (TCP) as the ideal homogeneous distribution, taking into account different CCDs in different PTVs (i.e. visible and subclinical regions). An adapted formulation of the linear-quadratic model, within the F-factor formalism, has been derived to preserve a chosen TCP value for the whole target volume. The F-factor has been investigated to show its potential applications in clinical practice.
2008-10-07
A comprehensive Network Security Risk Model for process control networks.
The risk of cyber attacks on process control networks (PCN) is receiving significant attention due to the potentially catastrophic extent to which PCN failures can damage the infrastructures and commodity flows that they support. Risk management addresses the coupled problems of (1) reducing the likelihood that cyber attacks would succeed in disrupting PCN operation and (2) reducing the severity of consequences in the event of PCN failure or manipulation. The Network Security Risk Model (NSRM) developed in this article provides a means of evaluating the efficacy of candidate risk management policies by modeling the baseline risk and assessing expectations of risk after the implementation of candidate measures. Where existing risk models fall short of providing adequate insight into the efficacy of candidate risk management policies due to shortcomings in their structure or formulation, the NSRM provides model structure and an associated modeling methodology that ...
2008-10-24
A boundary integral approach to unstable solidification
Energy Technology Data Exchange (ETDEWEB)
We consider the supercooled Stefan problem with a general anisotropic curvature- and velocity-dependent boundary condition on the moving interface. We present numerical methods, based on an integral equation formulation and including a new algorithm for moving curves with curvature-dependent velocity. These methods compute a periodic interface with {ital O}({Delta}{ital t}) accuracy, where {Delta}{ital t} is the time step. Previous work has been limited to short time spans and achieved slightly less than {ital O}({Delta}{ital t}{sup 1/2}) accuracy. Accurate numerical results are seen to agree with the predictions of linear stability theory. This agreement has eluded previous authors, because their numerical methods suffered from grid effects and their linear stability theory was incorrect. We study the long-time evolution of an unstable interface. Our computations exhibit the beginnings of a sidebranching instability when the boundary condition includes anisotropy ...
1989-12-01
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