This report documents the investigation regarding the failure of CPVC piping that was used to connect a solar hot water system to standard plumbing in a home. Details of the failure are described along with numerous pictures and diagrams. A potential failure mechanism is described and recommendations are outlined to prevent such a failure.
Chronic heart failure (HF) is a cardiovascular disease of cardinal importance because of several factors: a) an increasing occurrence due to the aging of the population, primary and secondary prevention...Full Text Available
Failures in cortical control of fronto-striatal neural circuits may underpin impulsive and compulsive acts. In this narrative review, we explore these behaviors from the perspective of neural processes...Full Text Available
ObjectivesTo describe the prospects, achievements, challenges and opportunities for implementing intermittent preventive treatment for malaria in pregnancy (IPTp) in Tanzania in...Full Text Available
Breaker failure relaying has been generally achieved through the use of a current monitoring relay to determine whether current continues to flow into a fault after a breaker has been instructed to interrupt the circuit. If current continues to flow after a predefined period of time, the circuit breaker is considered to have failed. Steps must then be taken to trip the next set of upstream breakers in the power system to remove the faulted circuit and prevent system damage. However, with industrial power systems, this may be the utility`s breakers on the feeding transmission line. Regardless, breaker failure schemes must be designed to isolate both the faulted circuit and the failed circuit breaker. This paper discusses a new and innovative method of protecting a circuit breaker from the failure described above, plus other failures that go unprotected with conventional schemes, this ...
BackgroundContrast-induced nephropathy is the leading cause of in-hospital acute renal failure. This side effect of contrast agents leads to increased morbidity, mortality, and health...Full Text Available
Silver-haired bat rabies virus (SHBRV) infection induces a strong virus-specific immune response in the periphery of the host, but death is common due to the failure to open the blood-brain barrier...Full Text Available
In the past few months, there has been public discussion relating to a new perspective on blood safety and specifically upon measures to prevent or discourage donation by individuals with a diagnosis of myalgic encephalopathy-chronic fatigue syndrome. This reflects an intriguing interplay between science, public health and public concern and illustrates some of the difficulties of making decisions in the face of uncertainty and inadequate information.
This article analyses the process of preparing the proposal for a new Finnish National Waste Plan (NWP 2007-2016). The focus of this study is on the use of the alternative concepts of waste prevention or material efficiency and on the shift in discourse from the former to the latter concept. The strengths and weaknesses of these competing concepts were analysed using criteria such as synergy, semantic aspects, legal context and applicability to monitoring. The discourse presented by different stakeholder groups was analysed. The implications of choosing either of the concepts were illustrated. The author concludes that waste prevention can be promoted just as well, or even better from the perspective of improving material efficiency. The concept must be complemented by policy instruments w...
In this work, a model for determining the optimal inspection and replacement periods of the safety system in Wolsung Nuclear Power Plant Unit 1 is developed, which is to minimize economic loss caused by inadvertent trip and the system failure. This model uses cost benefit analysis method and the part for optimal inspection period considers the human error. The model is based on three factors as follows: (i) The cumulative failure distribution function of the safety system, (ii) The probability that the safety system does not operate due to failure of the system or human error when the safety system is needed at an emergency condition and (iii) The average probability that the reactor is tripped due to the failure of system components or human error. The model then is applied to evaluate the safety system in Wolsung Nuclear Power Plant Unit 1. The optimal replacement periods which are calculated with ...
Carbon steel is frequently used to construct concentrated sulphuric acid storage tanks. This paper discussed the corrosion performance of carbon steel tanks and outlined the underlying mechanisms responsible for major corrosion modes. Analyses of hydrogen grooving and dilute acid corrosion failure mechanisms were presented. Recent corrosion-induced leak failures were also discussed. The use of anodic protection and organic coatings as a corrosion control measure was also evaluated. The results of laboratory studies that were conducted to understand corrosion-induced failures showed that carbon steel electrodes exhibited transpassive corrosion at relatively high anodic potentials, while stainless steel electrodes exhibited transpassive corrosion at anodic potentials less than 1 V. It was concluded that corrosion-induced leaks can be prevented by using anodic protection and baked phenolic coating ...
Design rules for robustness require insensitivity to local failure and the prevention of progressive collapse. This is often verified by applying the load case ''removal of a limited part of the structure''. This paper will evaluate typical structural systems for large-span timber roof structures against these requirements, comparing the results against typical reasons for damages and failures. Applying the finding that most failures of timber structures are not caused by random occurrences or local defects, but by global (repetitive) defects (e.g. from systematic mistakes), it is shown that the objective of load transfer-often mentioned as preferable-should be critically analysed for such structures. Based on these findings, proposals for structural systems and details towards a robust de...
We investigate, from a spacetime perspective, some aspects of Horowitz's recent conjecture that black strings may catalyze the decay of Kaluza-Klein spacetimes into a bubble of nothing. We identify classical configurations that interpolate between flat space and the bubble, and discuss the energetics of the transition. We investigate the effects of winding tachyons on the size and shape of the barrier and find no evidence at large compactification radius that tachyons enhance the tunneling rate. For the interesting radii, of order the string scale, the question is difficult to answer due to the failure of the {alpha}' expansion.
We reported previously that Fas-induced hepatic failure in normal mice was attenuated or prevented by exogenous transferrin (Tf), particularly apoTf. Here we show in C57BL6J/129 mice with genetic...Full Text Available
It is desirable to avoid vibration problems by following appropriate guidelines and specifications at the design stage. Accordingly, design specifications were developed to prevent tube failures due to vibration in nuclear steam generators and liquid heat exchangers. These specifications are outlined in this report. (author). 14 refs., 2 figs.
Abstract Introduction. Spinal cord stimulation (SCS) is an effective procedure for the treatment of neuropathic extremity pain, with success rates approaching 70%. However, mechanical failures, including breakage and migration, can significantly limit the long-term effectiveness of SCS. A systematic analysis of surgical techniques was undertaken by a consensus group, coupled with extensive in vivo and in vitro biomechanical testing of system components. Methods. A computer model based on morphometric data was used to predict movement in a standard SCS system between an anchored lead and pulse generator placed in various locations. These displacements were then used to determine a realistic range of forces exerted on components of the SCS system. Laboratory fixtures were constructed to subj...
Daya Bay Nuclear Power Plant is put into commercial operation in 1994 Until 1996, there are 368 human error events in operating and maintenance area, occupying 39% of total events. These events occurred mainly in the processes of maintenance, test equipment isolation and system on-line, in particular in refuelling and maintenance. The author analyses root causes for human errorievents, which are mainly operator omission or error procedure deficiency; procedure not followed; lack of training; communication failures; work management inadequacy. The protective measures and treatment principle for human error events are also discussed, and several examples applying them are given. Finally, it is put forward that key to prevent human error event lies in the coordination and management, person in charge of work, and good work habits of staffs.
The author explains current developments in high voltage cable technology and subsequently describes problems inherent in its application, from the users viewpoint, in municipal electricity supply. The planning of a high voltage cable network and the selection of a specific type of cable are not only dependent on the typical properties of various cables but to a major degree also on the feasible laying technique, the power transmitted, the costs, the stellation treatment of the high voltage network, the acceptance requirement, the inductive influence from telecommunication cable, thermal influences from the environment, eventual safeguards from mechanical and chemical damage to the network, frequency of failure and surveillance and breakdown location. In conclusion, the author portrays potential developments in the fields of high and maximum voltage cable from the perspectives of today.
An overall view of the 1982 plant operating performance is presented. All periods of ON-FEED operation, UNSCHEDULED SHUTDOWNS, and SCHEDULED SHUTDOWNS are accounted for and tabulated. Causes of UNSCHEDULED SHUTDOWNS are identified and discussed. Plant solutions aimed at reducing the effect of similar future shutdowns or preventing recurrence of such shutdowns are explained. Details of repeated, major maintenance problems with various pieces of equipment are presented. Discussion of each problem and solutions found during 1982 are given, where applicable.
Ferrography is a technique for isolating wear particle debris from lubricating and hydraulic oils, the presence of which carry with them a history of the wear processes in the machine. Thus, the technique has fundamental applications in machine condition monitoring and failureprevention. The wear particles are significant in the metal types that are present in the particle distribution as an indication of the wearing machine components and in the particle size distribution and morphology which indicates the severity of wear in the system. In this paper, the fundamental principles which describe the working of the ferrograph, concentrating on the working of the on-line ferrograph are discussed. The significance of equilibrium particle concentration in the oil system and its measurement using the ferrograph are also discussed.
Most designers are not schooled in the area of human-interaction psychology and therefore tend to rely on the traditional ergonomic aspects of human factors when designing complex human-interactive workstations. Unfortunately, by ignoring the importance of the integration of the user interface at the psychophysiological level, the result can be ineffective use of a system leading to an inherently error- and failure-prone system. Therefore, to minimize failures in a human-interactive system, it is essential that designers understand how each user`s processing characteristics affect how the user gathers and processes information. By understanding the significant processing characteristics of the user, designers can implement practical and effective visual displays (or any other type of system) that are more desirable to all users. The material presented in this paper is based on a general study that involved users` ...
The objective of this work group was to identify obstacles to the development of better risk management practices and performance standards in the pipeline industry. An outline of developments in pipeline risk assesment management was presented, including an update of the Risk Based Design and Assessment annex and other CSA Z662 code developments. It was suggested that progress in risk management require that acceptable levels of risk and reliability need to be defined. Environmental and safety consequence analysis was recommended, as well as failure frequency estimation and assessment of distribution systems. Guidelines for Integrity Management Programs (IMPs) were reviewed. It was noted that CSA Z662 will become mandatory for sour gas in 2005 and may become mandatory for all onshore pipelines in 2007. Operating company procedures in relation to hazards with significant consequences were discussed. It was noted that companies should assess risks associated with ...
Since the mid-1990s, nuclear power plants in Korea have experienced wall thinning, leaks, and ruptures of secondary side piping caused by flow-accelerated corrosion (FAC). The pipe failures have increased as operating time progresses. In order to prevent the FAC-induced pipe failures and to develop an effective FAC management strategy, KEPRI and KOPEC have conducted a study for developing systematic FAC management technology for secondary side piping of all Korean nuclear power plants. As a part of the study, FAC analyses were performed using the CHECWORKS code. The analysis results were used to select components for inspection and to determine inspection intervals on each nuclear power plant. This paper describes the introduction of the FAC analysis method and the wall thinning trend analysis results by reactor type, system, and water treatment amine. This paper also represents the site application feasibility for ...
Preventing recurrence of surface mining accidents in the coal industry remains a top priority requiring constant vigilance and a substantial commitment from all involved in open pit mining operations. Open pit wall failures, loose rocks rolling down slopes, ground water and stockpiling procedures are common sources of risks in open cut coal operations. This video aims to equip workers with the necessary skills and knowledge to assess and react to the geomechanics hazards in open pit coal operations. Workers need to have the competencies to manage geomechanics hazards to facilitate their own and their workmates' safety. No matter how good the operating systems are, the first line of defence against accidents is the experience, skill and knowledge-based judgment of each individual mine worker. The video covers: Open pit coal mine risk management and geomechanical issues; Terminology, mining cycle, and explanation of pit slope hazards; ...
In the years 2004 and 2005, Korea became a prospective nation noteworthy in the world through the epochal development of genetic engineering in our country. Obstinate or incurable diseases were expected to be healed in a few years by a Korean geneticist. So many worldwide patients of obstinate or incurable diseases took notice of the research outcomes and organized an aid association to collect supporting funds. World renowned journals such as 'Nature' and 'Science' published Dr. Hwang's theses. A long and distant way remedy to obstinate diseases seemed to be closer at hand so early. However, a stem cell fraud case emerged throughout the world in late 2005, the pride of the Korean people was destroyed. With this as a momentum, voices of self reflection by scientific circles were raised. The purpose of this study is not in finding the truth of the stem cell research but to propose an effective management and control measures for the future in planning, implementing, monitoring and ...
The DGs (Diesel Generators) in NPP (Nuclear Power Plant) has been used for the emergency electric power source to shot down the nuclear reactor safety in case of station blackout. The RCM (Reliability Centered Maintenance) has been applied to DGs for increasing the safety of NPP. The structured defects of DG were not remedied by the improvement of maintenance method. As the first stage of RCM, to find the structured defect, its failure= models were searched and analyzed through the ten year maintenance information. The structured defects such as the air compressor, the lubricating oil pressure, and the insufficient load were the root causes of main failures. The air reservoir reinstallation, the lubricating oil tube modification, the load bank installation, and the qualitative instrumentation were the solutions for the hardware oriented RCM of DGs. There remains the software oriented RCM such as the rejection of useless maintenance, the ...
The application of HVDC system to the trunk power supply system requires the transmission of DC power as much as possible to improve the stability of the whole AC/DC system. To meet this requirement, continued pulse system, which keeps sending a DC current even when an AC voltage lowers remarkably, has been used. The stability is much more improved by adding damping control which modulates converter active and/or reactive power. In order to make full use of such control effects, it is important that the HVDC system maintains stable operation during faults and reclosing of the AC system. In particular, it is necessary to prevent a repetitive commutation failure following the unbalanced AC transmission line faults. In this paper, the cause of the repetitive commutation failure is discussed by using the AC-DC power system simulator developed by CRIEPI. Based on the analytical result, a stabilization control scheme with on-line ...
Steel structures immersed in seawater are protected from corrosion using cathodic protection systems (sacrificial anodes or impressed current), by paint coatings or by duplex systems in which cathodic protection hinders corrosion at coating's failure sites. The main problem related to those duplex systems is how to avoid cathodic delamination due to the alkalinity generated at cathodic sites. The present paper analyses the effectiveness of red mud suspensions as pre-treatment to avoid cathodic delamination. The study was conducted using mainly electrochemical impedance spectroscopy (EIS). The evolution of the electrode potential with immersion time was also recorded because it concerns the practical aspect of current density necessary to reach the protection potential. The study shows that red mud pre-treatments are effective in avoiding coating's delamination. (author)
Fabry Perot interferometry is a method of determining instantaneous velocities of an object in motion. The interferometer system is composed of the Fabry Perot interferometer, a laser, an electronic streak camera, and several focusing lenses. The first tests discussed were done on exploding bridgewire devices. During these tests, several system parameters were changed. These changes did not seem to affect the data, which appeared to be consistent. The second tests performed focused on slapper-type devices. It was determined that sandblasted, vapor-deposited aluminum on the slapper material would be required to yield quality data. Streak camera failureprevented much data from being collected. An effort is being made to replace the current streak camera. After it is replaced, a Fabry Perot and velocity interferometry system for any reflector comparison will be made. The results will be published as the conclusion to this report.
Industrial radiography accounts for approximately half of all the reported accidents for the nuclear related industry, in both developed and developing countries. This Safety Report is the result of a review made of a large selection of accidents in industrial radiography reported by regulatory authorities, professional associations and scientific journals. A small, representative selection of 43 accident descriptions has been used to illustrate the primary causes of radiography accidents, and a set of measures provided to prevent the recurrence of such accidents or to mitigate the consequences of those that do occur. These accident descriptions were categorized by primary causes as follows: inadequate regulatory control; failure to follow operational procedures; inadequate training; inadequate maintenance; human error; equipment malfunction or defect; design flaws; and wilful violation. The information in this Safety report is intended for use ...
The very low-pressure expansion tank of the title invention is connected to the water in the central heating installation via a connecting pipe with a pump and valves on one side, and on the other side the tank is connected via a connecting pipe with valve to the tap water mains, so that the supply of water can be regulated automatically. Within the expansion tank contact with the outside air is not possible because of an air/water separating floater. By means of recording and control (also remote) of the contents of the expansion tank, the installation pressure and the quantity of supplied water from the expansion tank and the tap water mains, failures and water damage are prevented. 4 figs.
This new book presents a practical how to approach to understanding and solving the problems of corrosion of structural materials. Although it is written mainly for those having a limited technical background in corrosion, it also provides more experienced engineers with a useful overview of the principles of corrosion and can be used as a general guide for developing a corrosion-control program. Contents include: the effects and economic impact of corrosion; basic concepts important to corrosion; principles of aqueous corrosion; forms of corrosion: recognition and prevention; types of corrosive environments; corrosion characteristics of structural materials; corrosion control by proper design; corrosion control by materials selection; corrosion control by protective coatings and inhibitors; corrosion control by cathodic and anodic protection; corrosion testing and monitoring; techniques for diagnosis of corrosion failures; and glossary of ...
Objective was to present our 8 year experience in the prevention of the obturator nerve reflex during transurethral resection of bladder tumors. This study was performed in Ataturk University Hospital between 1999 and 2007. We retrospectively reviewed the records of 89 patients with inferolateral bladder tumors, who underwent transurethral resection under epidural or general anesthesia and requested obturator nerve reflex inhibition. Epidural anesthesia was administered to 57 patients, while the remaining 32 patients underwent general anesthesia via mask; and succinylcholine was administered prior to resection. Of the 57 patients received epidural anesthesia, 18 were diagnosed as inferolateral bladder tumors during endoscopy and had to undergo general anesthesia. Obturator nerve block was attempted preoperatively in 39 patients. However, a nerve identification failure, hematoma and 4 obturator nerve reflex events, despite the block, were ...
PWR steam generators have suffered from a variety of degradation phenomena. This paper identifies the corrosion-related defects and their probable causes and suggests approaches to correct and prevent corrosive activity. In the attempt to solve the degradation problems, research programs have concentrated on modifying materials, stresses, and the chemical environment in both new and operating steam generators. The following corrosion-related defects have been studied: tube wastage, denting, primary side (ID) intergranular stress corrosion cracking (IGSCC), OD-initiated intergranular attack (IGA), pitting, and corrosion fatigue. Plants affected by wastage have greatly reduced their problem by adopting an all volatile treatment (AVT). In the case of denting, a less aggressive chemical environment is recommended. Primary side IGSCC responds to temperature reduction, stress relief, and material improvements, while flushing and boric acid addition minimizes OD-initiated ...
PWR steam generators have suffered from a variety of degradation phenomena. This paper identifies the corrosion-related defects and their probable causes and suggests approaches to correct and prevent corrosive activity. In the attempt to solve the degradation problems, research programs have concentrated on modifying materials, stresses, and the chemical environment in both new and operating steam generators. The following corrosion-related defects have been studied: tube wastage, denting, primary side (ID) intergranular stress corrosion cracking (IGSCC), OD-initiated intergranular attack (IGA), pitting, and corrosion fatigue. Plants affected by wastage have greatly reduced their problem by adopting an all volatile treatment (AVT). In the case of denting, a less aggressive chemical environment is recommended. Primary side IGSCC responds to temperature reduction, stress relief, and material improvements, while flushing and boric acid addition minimizes OD-initiated ...
The mining and energy industry is under assault today for reasons that have less to do with alleged technical failures and much more to do with ethical complaints about a rate of growth in population that industrial products from mining resources have made possible. The political agendas of Western industrialized nations have been driven during the past quarter century by those whose social philosophy advocates a new ethic of biocentric equality, whereby humans must be forced to being `living as if Nature mattered`. A Green ethic requires that `a violent, plundering humankind` must abandon its alleged rape of the earth and derive its ethical norms from pre-existing ecosystemic harmonies to preserve a fragile and precarious balance existing in Nature. From the perspective of history, there is nothing new about such complaints, current complaints about the use of fossil fuels and pollution from mining, echo similar complaints in past periods. ...
This paper reports on the superiority of zeolites over amorphous solids which is well documented for solid acid catalysts of industrial use. Crystalline supports, likewise, open attractive perspectives for catalysis by metals, alloys, and ligated metal clusters. Size and location of clusters can be controlled by careful design of the preparation conditions. Pore dimensions control the access of reactants to active sites and escape paths for products. Cage dimensions determine which transition states can be attained; window apertures are functional in isolating metal clusters from each other, thus preventing ther coalescence and growth. The ship-in-a-bottle method permits deisgn of fairly large active complexes entrapped in zeolite cages. Orientation of non-spherical molecules in a zeolite proe helps to direct their collision with a metal particle to the head on mode; however, isolated Pt atoms hidden in niches of the pore walls can attack ...
This perspective view of Venus, generated by computer from NASA's Magellan data and color-coded with emissivity, shows part of the lowlands to the north of ...
An independent investigation of pipe welding leaks from the Low-Level Waste 2 (LLW2) Skid-B System for the possibilities of improper welding (IW), microbiologically influenced corrosion (MIC), sensitization, chloride pitting corrosion (CPC), and intergranular stress corrosion cracking (IGSCC) was conducted. The results show the prevailing mechanisms that caused the leaks are identified as IW, CPC, and the improper selection of weld filler material for the base metals in an environment of the North Plateau underground water. These is no evidence of MIC, sensitization, or IGSCC. The chloride pitting corrosion mechanism that took place at all the welds are also described. All the pipelines were replaced with polyvinyl chloride (PVC) for cost saving and the LLW2 Skid B System has been successfully operating since 1999. This report summarizes the findings and recommendations associated with preventive measures for future operations. The LLW2 Facility is a replacement ...
Seventeen eyes of patients who were being followed by their ophthalmologists for aphakic (8 eyes) or pseudophakic (9 eyes) cystoid macular edema (CME) were examined on referral. All eyes showed retinal detachment (RD), and eight eyes had CME with RD. Most RDs were inferior and shallow. Proliferative vitreoretinopathy (PVR) was noted in 15 eyes (88.2%). There was history of vitreous loss during the last intraocular surgery in 88.2% eyes. Visual acuity ranged from 20/40 to hand movements. Fundus view was hazy in most eyes, and indirect ophthalmoscopy was most useful in detecting RD. Retinal reattachment with scleral buckling and/or vitrectomy was achieved in 16 eyes (94.1%). Postoperative visual recovery was jeopardized due to longstanding macular detachment of greater than 1 month in 11 eyes (64.7%). Eight eyes (47%) achieved 20/50 vision whereas 25% did not improve to better than 20/400. Factors leading to failure in making the correct diagnosis and their ...
The main reasons of tube failures in steam generators (SG) are considered. 1.Stress corrosion craining which has 28% of SG (most of them have stainless steel tubes). 2. Corrosion loss of metal, which accounts for 24% of tubes (phosphate corrosion due to addition of PO into water). 3.Denting-peripheral pressing of tubes in the openings of the foundation plates by the corrosive products, which are formed on internal surface of drillings in the foundation plates made of carbon steel. 4.Separation of a plating layer on tube panels. 5.Dratting-corrosion. 6.Metal fatigue. A series of experiments were conducted to study the influence of material selection on tube reliability (stainless steel 304, inconel-600, mone-400, incalloy-800). The problem of increase of SG elements reliability is a complex one and can be solved by direct selection of material, proper control of water-chemical conditions and other measures of corrosion prevention such as direct ...
Burner nozzles were often redesigned in order to improve flow design and manufacturing quality. Maintenance intervals, however, are not satisfactory for the operators of such plants. There is no definitive answer as to whether upgraded design allows to lengthen these intervals or whether additional measures are required. Gas turbines may break down for a large number of reasons. This article shows that many of the causes of operational failure and damage are preventable. Damage management will be successful if manufacturers, operators and independent institutions work together.(orig.) [German] Es wurden in der Vergangenheit mehrfach Veraenderungen an den Brennerduesen vorgenommen. Dabei wurden Verbesserungen in der stroemungstechnischen Auslegung und der Fertigungsqualitaet erzielt. Die derzeit noch gueltigen Wartungsintervalle sind fuer den Betreiber unbefriedigend. Inwieweit diese Intervalle mit der modifizierten Ausruestung verlaengert ...
During 17 years since the start of operation of the first commercial LWR in Japan, many LWRs have experienced various corrosion damages, but the causes of them were clarified, and the counter-measures were executed effectively in actual plants, as the results, the cause of corrosion damage decreased remarkably, and now, the high rate of operation has become to be maintained. In this paper, the major cases of corrosion damage experienced in LWRs in Japan and foreign countries, the causes of them and the countermeasures, the problems of hereafter and so on are described. The corrosion damage of metallic materials in the environment of LWRs occurs in the parts in contact with high temperature, high pressure water and steam, such as stainless steel piping in the primary cooling system of BWRs, and nickel alloy heating tubes of steam generators, carbon steel feed water piping and zirconium alloy fuel cladding tubes in PWRs. Recently, accompanying the advance of LWR technology, the ...
During 17 years since the start of operation of the first commercial LWR in Japan, many LWRs have experienced various corrosion damages, but the causes of them were clarified, and the counter-measures were executed effectively in actual plants, as the results, the cause of corrosion damage decreased remarkably, and now, the high rate of operation has become to be maintained. In this paper, the major cases of corrosion damage experienced in LWRs in Japan and foreign countries, the causes of them and the countermeasures, the problems of hereafter and so on are described. The corrosion damage of metallic materials in the environment of LWRs occurs in the parts in contact with high temperature, high pressure water and steam, such as stainless steel piping in the primary cooling system of BWRs, and nickel alloy heating tubes of steam generators, carbon steel feed water piping and zirconium alloy fuel cladding tubes in PWRs. Recently, accompanying the advance of LWR technology, the ...
Due to the failure of the instrument and control devices of nuclear power plants caused by aging, nuclear power plants occasionally trip. Even a trip of a single nuclear power plant (NPP) causes an extravagant economical loss and deteriorates public acceptance of nuclear power plants. Therefore, the replacement of the instrument and control devices with proper consideration of the aging effect is necessary in order to prevent the inadvertent trip. In this paper we investigated the optimal replacement periods of the control computer's components of Wolsung nuclear power plant Unit 1. We first derived mathematical models of optimal replacement periods to the digital control computer's components of Wolsung NPP Unit 1 and calculated the optimal replacement periods analytically. We compared the periods with the replacement periods currently used at Wolsung NPP Unit 1. The periods used at Wolsung is not based on mathematical analysis, but on ...
Many mechanical parts are subjected to stresses and strains that may eventually lead to their failure. In order to prevent the costly delays associated with equipment down-time, many parts have to be tested for weaknesses and defects when machinery is constructed or dismantled for maintenance. These procedures are known as Non-Destructive Testing (NDT) methods. Five types of non-destructive testing methods routinely used are radiographic testing, ultrasonic testing, magnetic particle inspection, liquid penetrant testing and eddy current testing. Out of these five techniques industrial radiography plays an important role in non-destructive testing to reveal interior defects in materials. In radiography almost two-thirds of the radiation reaching the film is scattered radiation which does not form the image of defects. Scattered radiation generated inside and outside a material has a very large effect on sensitivity of flaw detection since it ...
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
On June 2, 1992, Landers` earthquake struck the Solar Electric Generating System II, located in Daggett, California. The 30 megawatt power station, operated by the Daggett Leasing Corporation (DLC), suffered substantial damage due to structural failures in the solar farm. These failures consisted of the separation of sliding joints supporting a distribution of parabolic glass mirrors. At separation, the mirrors fell to the ground and broke. It was the desire of the DLC and the Solar Thermal Design Assistance Center (STDAC) of Sandia National Laboratories (SNL) and to redesign these joints so that, in the event of future quakes, costly breakage will be avoided. To accomplish this task, drawings of collector components were developed by the STDAC, from which a detailed finite element computer model of a solar collector was produced. This nonlinear dynamic model, which consisted of over 8,560 degrees of freedom, underwent model reduction to form a ...
Aging degradation is a phenomenon we all experience throughout life, both on a personal basis and in business. Many industries have been successful in postponing the inevitable impact on their related systems and components through programs to maintain long-term reliability, maintainability and safety. However, this has not always been the case for nuclear power. While all power plants are experiencing the world trend of increasing operating costs with age, few (if any) have been able to fully define the parameters that solve the aging equation, particularly in relation to major components. Inspection and preventive maintenance have not been effective in predicting life-limiting degradation and failure. In CANDU nuclear plants, utilities are taking a comprehensive approach in dealing with the aging problem. Programs have been established to identify the current condition and degradation mechanisms of critical components, the ...
In acute liver failure following hepatitis, toxic insults, or after major liver surgery, there is an increased bacterial translocation from the gut. This may explain some of the infectious complications seen in these conditions. To elucidate mechanisms and find possible preventive measures, we investigated the effect of rectal administration of arginine and probiotic bacteria (Lactobacillus spp.) on bacterial translocation and the extent of liver failure. Sprague-Dawley rats were used and five different Lactobacillus strains (Lb. reuteri R2LC, Lb. rhamnosus DSM 6594 (= strain 271), Lb. plantarum DSM 9843 (= strain 299v), Lb. fermentum 8704:3 (= strain 245), and Lb. reuteri (= strain 108) were administered rectally once daily for 8 days with and without 2% arginine. Acute liver injury (ALI) was induced on the eighth day by intraperitoneal injection of D-galactosamine (1.1 g/kg body weight), and samples were collected after ...
This paper discusses the fundamentals, applications, potential, limitations, and future perspectives of polarized light reflection techniques for the characterization of materials and related systems...Full Text Available
Objectives To understand the perspectives of people with severe chronic obstructive pulmonary disease (COPD) as their illness progresses, and of their informal and professional carers,...Full Text Available
Objective To determine whether a centralised telephone intervention reduces the incidence of death or admission for worsening heart failure in outpatients with chronic heart failure.Design...Full Text Available
Heart failure affects nearly 6 million Americans, with a half-million new cases emerging each year. Whereas up to 50% of heart failure patients die of arrhythmia, the diverse mechanisms underlying...Full Text Available
Failure of a dam is something we hope never happens. But if a failure occurs, it`s important to study the circumstances in order to expand our knowledge base, and then apply what we learn to other structures.
Heart failure has been singled out as an emerging epidemic, which could be the result of increased incidence and/or increased survival leading to increased prevalence. Knowledge of the responsibility...Full Text Available
BackgroundProvision of consumer information and patient education are considered an essential part of chronic disease management programmes developed for patients with heart failure....Full Text Available
Ultimate compressive strength and failure modes were studied using 24- ... to 81 % of the average ultimate compressive strength (UCS). Figure 1 (a) is the failure ...
Congestive heart failure (CHF) is a leading cause of morbidity and mortality. CHF is marked by atrial and ventricular enlargement and reduced cardiac contractility, as well as an association...Full Text Available
Diagnostic accuracy of the currently available serum markers of cardiac injury, such as myoglobin, creatine kinase and its myocardial isoform, are altered in patients with renal failure. It is shown...Full Text Available
Purpose : To evaluate whether the early pulmonary irradiation can prevent or decrease the pulmonary damage and contribute to improve ultimate survival in paraquat lung. Materials and Methods : From Jun. 1987 to Aug. 1993, thirty patients with paraquat poisoning were evaluated. Fourteen of these patients were received pulmonary irradiation(RT). All of the patients ere managed with aggressive supportive treatment such as gastric lavage, forced diuresis, antioxidant agents and antifibrosis agents. Ingested amounts of paraquat were estimated into three groups(A: minimal < about 5cc, B: mouthful 5-50 cc, C: Large > 50cc). Pulmonary irradiation was started within 24 hours after admission(from day 1 to day 11 after ingestion of paraquat). Both whole lungs were irradiated with AP/PA parallel opposing fields using C0-60 teletherapy machine. A total of 10Gy(2Gy/fr. X 5 days)was delivered without correction of lung density. Results : In group A, all patients ...
Power system components, especially components failure, can significantly affect the reliability of a power system. Data about failure rate in electrical products were obtained from products life testing and analyzed in order to predict reliability. The distribution curve fitting method was used to estimate failure probability. Ten relays of different life times have been used to illustrate the validity of this analytical technique. 3 refs., 3 tabs.
A survey was conducted of experience with steam generator tubes at nuclear power stations during 1976. Failures were reported at 25 out of 68 water-cooled reactors. The causes of these failures and the repair and inspection procedures designed to cope with them are summarized. Examination of the data indicates that corrosion was the major cause of steam generator tube failures. Improvements are needed in steam generator design, condenser integrity and secondary water chemistry control. (author).
Extensive investigations and detailed analysis of the failure reason of 9DVN002ZV fan in Daya Bay Nuclear Power Station showed that the fan destroy was caused by the failure of non-drive end bear. The direct cause of this bearing' failure was its improper assembly caused by improper maintenance procedure, and the root cause was too small internal radial clearance after mounting. The factor affecting bearing internal radial clearance, the relationship between clearance and operating life time and fan failure process were discussed. (authors)
The failure took place on a welded elbow pipe which exhibited a catastrophic transverse rupture. The failure was located on the welding HAZ region, parallel to the welding path. Branching cracks were detected at the edge of the rupture area. Deposits of corrosion products were also spotted. The optical microscope analysis showed the presence of transgranular failures which were related to the stress corrosion cracking (SCC) and were predominantly caused by the welding residual stress. The significant difference in hardness between the welded area and the pipe confirmed the findings. Moreover, the failure was also caused by the low Mo content in the stainless steel pipe which was detected by means of spark emission spectrometer. (orig.)
This Fact Sheet presents the mission of the West Valley Demonstration Project and information on the 1994 pollution prevention and recycling accomplishments.
This paper attempts to clarify the most common measures available for the fire and electrical engineer in the prevention of polychlorinated biphenyl (PCB) hazards. It points out the risks and the potential...Full Text Available
The purpose of the recommendation is to prevent, to detect, and to remove soiling of guide and retrating blades of steam turbines, e.g. on account of foreign matter in steam dissolved. (TK/LN).
... elevated blood sugar levels, but not full-blown diabetes. What are the keys to preventing the disease? ... been well studied, in a study called The Diabetes Prevention Program, in several thousand people with this ...
Hexavalent chromium in corrosion preventive coating 64 ...To prevent corrosion of rims, weights can be provided with a coating. ...integrated clips brought up technical problems due to corrosion
Radio-biologists have pointed out a novel radiobiological phenomenon observed in many tumor and normal cell lines: hyper-radiosensitivity to very low-dose (H.R.S.) followed by induced radioresistance (I.R.R.) after a threshold dose of 0.1-0.3 Gy that depends on the cell line. Radioresistance at high dose (i.e. higher than 0.5 Gy) and metastatic potential of tumor cells are likely major factors of failure in radiotherapy. A careful review of literature suggests that: 1) radiotherapy does not increase the metastatic potential of tumor cells; 2) radioresistance at high dose and metastatic potential are not related. However, inside a given tumor cell line, highly metastatic clones may elicit more cells showing H.R.S; or are more radiosensitive at high dose than poorly metastatic ones. Recent data obtained from molecular techniques (comet and immunofluorescence assays) applied to single cells irradiated at very low radiation doses (1-100 mGy) suggest that DNA ...
In order to prevent corrosion failures of machines and structures, it is desirable to know in advance when the corrosion damage will take place, and appropriate measures are needed to mitigate the damage. The corrosion predictions are needed both at development as well as operational stage of machines and structures. There are several forms of corrosion process through which varying degrees of damage can occur. Under certain conditions these corrosion processes at alone and in other set of conditions, several of these processes may occur simultaneously. For a certain type of machine elements and structures, such as gears, bearing, tubes, pipelines, containers, storage tanks etc., are particularly prone to pitting corrosion which is an insidious form of corrosion. The corrosion predictions are usually based on experimental results obtained from test coupons and/or field experiences of similar machines or parts of a structure. Considerable ...
In Aug 2002, the National Nuclear Safety Administration of China issued the policy statement for building new nuclear power plants, which requires the probability based safety goal of severe core damage must be lower than 10"-"5/a. The station blackout accident would be possible to cause a severe accident if there were no effective engineering measures to prevent or mitigate the consequences of the accident. By using MELCOR1.8.5 and KORIGEN codes, the present paper has simulated the station blackout accident for Daya Bay Nuclear Power Plant and calculated the source term and radioactivity of main fission products in the containment in the late phase of the accident. CsI is found the main part of aerosol in the containment. The Xe133 and Xe133m start releasing from the containment after its failure, and the upper limit of the amount of released radioactivity is evaluated less than 5.5 x 10"1"5Bq. The total radioactivity of other significant ...
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 mutual needs of ...
Hamiltonians of Landau-Ginzburg-Wilson type are constructed for order parameters which are bases for certain high-dimensional irreducible or physically irreducible representations in A-15 structure. These are all the representations with wave vectors ?, X, and R and encompass cases of dimension 1, 2, 3, 4, and 6. A renormalization-group analysis was performed on each new distinct Hamiltonian using the Wilson-Fisher "? expansion" method to order ?, in order to determine fixed points and stability, and critical exponents. For representations of R wave-vector symmetry, only the two-dimensional R(1) has a stable fixed point and may produce a second-order phase transition; for all other R wave vector representations, fluctuations prevent second-order transition. No X point representation gives a second-order transition. Representations at ? which are permitted to be second order by "Landau theory" remain so in this analysis. Generally, if the dimension of the ...
Piping systems transporting high-pressure fluid will release a large amount of energy, leading to whipping of the broken pipe as well as impingement of the ejecting fluids on adjacent structures if they fracture unstably. Postulation of such an event in design of piping systems in nuclear power plants often requires various counter measures such as installation of pipe whip restraints or jet impingement shields to prevent such damage. One of the approaches to justify exclusion of unstable fracture from the design conditions is leak-before-break (LBB) analysis. In order to demonstrate LBB behavior, it is necessary to prove that in the presence of a part-through wall flaw in the pipe, this flaw will not grow through the wall under fatigue loading and is stable (level 2 LBB) and that the leak of fluid through the penetration is detected by leak detection systems before unstable fracture occurs (level 3 LBB). If this can be demonstrated in plant design, significant ...
Understanding the mechanical properties of biomedical devices is critical in predicting and preventing their failure in the body. Such knowledge is essential, for example, in the design of biomedical stents, which must undergo repeated strain over their ten year lifetimes without breaking. Computational models are used to predict mechanical response of a device, but these models are not complete; there are significant deviations from the predictions, especially when devices are subjected to repeated multi-axial loads. Improving these models requires comparisons with actual measurements of strained nitinol. Local measurements of the full strain tensor can be made using X-ray diffraction techniques, but they are currently limited to materials whose grain size is larger than the X-ray beam size or require several diffraction patterns produced by rotation of the sample. Nitinol stents are nanocrystalline, with grains smaller than any available ...
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 formulations averaged from 11.6 to ...
Gas evolution in aluminum electrolytic capacitors constitutes one of their main drawbacks in comparison to other types of capacitors lacking a liquid electrolyte. In this respect, one of the most common causes of failure shown by liquid electrolyte capacitors is electrolyte leakage through the seal or even explosions produced by internal pressure buildup. In order to prevent these hazards, some substances, known as depolarizers, are usually added to the capacitor electrolyte with the purpose of absorbing the hydrogen evolved at the cathode (1, 2). Although the gas evolution problem in electrolytic capacitors has been known for a long time, there is a lack of literature on both direct measurements of the gas evolved and assessments of the amount of depolarizer active for the hydrogen absorption process. Aluminum electrolytic capacitors of 100..mu..F and 40V nominal voltage, miniature type (diam 8 mm, height 18.5 mm), were manufactured under ...
The Candu 6 reactor assembly consists of an array of 380 pressure tubes, which are installed horizontally in a large cylindrical vessel, the Calandria, containing the low pressure heavy water moderator. The pressure tube is located inside calandria tube and the annulus between these tubes, which forms a closed loop with CO{sub 2} gas recirculating, is called the Annulus Gas System (AGS). It is designed to give an alarm to the operator even for a small pressure tube leak by a very sensitive dew point meter so that he can take a preventive action for the pressure tbe rupture incident. To judge whether the operator action time is enough or not in the design of Wolsung 2, 3, and 4, the Leak Before Break (LBB) assessment is required for the analysis of the pressure tube failure accident. In order to provide the required data for the LBB assessment of Wolsung Units 2, 3, 4, a series of leak detection capability tests was performed by injecting ...
PURPOSE: The purpose of this investigation was to study vision in albinism from 3 perspectives: first, to determine the characteristics of grating acuity development in children with albinism; second,...Full Text Available
... second way in which social science dif- fers from the ... it would have been better to leave it intact ... to deploy, returning with worn vessels and sick crews ...
In the wake of the 2010 earthquake in Haiti, medical relief organizations and individual practitioners mobilized to provide assistance. Here, an emergency medicine physician who worked with a Louisiana-based...Full Text Available
A growing body of evidence in cognitive science and neuroscience points towards the existence of a deep interconnection between cognition, perception and action. According to this embodied perspective...Full Text Available
Typing Workshop": [Introductions] [Intro, DNA Basics, and Historical Perspective] [DNA Extraction] [Validation and QA/QC] [DNA Quantitation] [PCR Amplification] [STR Loci and Kits]...
Insofar as international conferences reflect the state of development of the subject under discussion, they provide an opportunity to question, at a rather fundamental level, the direction of and progress...Full Text Available
... heavy divisions in the Contingency Corps should ... During Operation Desert Shield the 82nd Airborne Division initially deployed a reinforced attack ...
... and (3) the exchange of information; materials or perspectives. In 1977, a conference of ... their peers), to products (e.g., curriculum materials, guidebooks, or videos). We will also take ...
In contrast to the increasing availability of information pertaining to the care of children with chronic kidney disease (CKD) from large-scale observational and interventional studies, epidemiological...Full Text Available
Hypertension affects most hemodialysis patients and is often poorly controlled. Adequate control of blood pressure is difficult with conventional hemodialysis alone but is important to improve...Full Text Available
S>Hydrogen-induced delayed failure in an alpha-beta titanium alloy (4Al-- 4Mn) was sensitive to microstructure. A quenched structure was less susceptible to delayed failure than aged or annealed structures. The tendency for delayed failure was magnified in all structures by an increase in hydrogen content or an increase in strength level. Hydrogen-induced delayed failure occurred by a process of crack initiation and controlled crack growth. Delayed failures resulting from creep were also encountered. Plastic strain resulting from creep tended to retard crack initiation. Changes occurring in material under static load prior to formation of cracks were reversible, as long as no appreciable plastic strain occurred, indicating stress-induced diffusion of hydrogen. Hydrogen-induced delayed failure disappeared at both high and low ...
Abstract Background: Premature ovarian failure is diagnosed with a picture of amenorrhea, elevated follicle-stimulating hormone (FSH), and age under 40 years. Twenty percent (20%) of patients with premature ovarian failure have a concomitant autoimmune disease. Cases of premature ovarian failure associated with Sj?gren syndrome have been reported in the literature. Patient and method: We report a case of a 42-year-old white woman with Sj?gren syndrome and premature ovarian failure who underwent a reversal of her premature ovarian failure and restoration of normal menses using an elimination diet protocol. The patient was diagnosed with her rheumatological condition in 2005 and started on disease-modifying antirheumatoid drugs, which were taken intermittently due to a concern over medicatio...
The petroleum and petroleum products increase offer a real development opportunity to the alternative fuels. In the context of the french energy accounting increase, the energy independence notion incites the government to promote these new fuels. If the LPG seems declining because of the accident risks fear, the fuel cell is not for today. Near these two sectors what is the future of the biofuels and the natural gas vehicle or the electric cars? (A.L.B.)
Several of the issues of the workshop are addressed from the perspective of a potential Space Station developer and energy wheel user. Systems considerations are emphasized rather than component technology. The potential of energy storage wheel (ESW) concept is discussed. The current status of the technology base is described. Justification for advanced technology development is also discussed. The study concludes that energy storage in wheels is an attractive concept for immediate technology development and future Space Station application.
Institutional issues play a critical, but often overlooked, role in the implementation of renewable energy systems. This paper briefly reviews the institutional arrangements involved in deploying renewable energy from both the sender and receiver perspectives, giving the institutional basis principal characteristics, and pros and cons of each institution. It then offers several perspectives on the critical issues facing the deployment of renewable energy systems before offering a number of potential institutional based solutions. (author)
The advent of sophisticated automation equipment and computer hardware and software is changing the way manufacturing is carried out. To compete in the global marketplace, manufacturing companies must integrate these new technologies into their factories. In addition, they must integrate the planning, control, and data management methodologies needed to make effective use of these technologies. This paper provides an overview of recent approaches to achieving this enterprise integration. It then describes, using simulation as a particular example, a new tool`s perspective of enterprise integration.
Increasingly, utility organizations recognize the value of sharing data and applications among their computing environments. A typical utility`s computing environment may consist of disparate computer platforms. The focus of this paper is to highlight importance of a documented information technology architecture for identifying business perspectives for interoperability, and to brief utility management about the Electric Power Research Institute`s (EPRI) accomplishment along these same lines.
...Observatory Edinburgh SkyView Virtual Observatory Solar System Simulator Space Telescope Science Institute Space Weather : A Research Perspective Subaru Telescope Project Two Micron All ...Universities for Research in Astronomy Subjects: space observation DeweyClass: 522 Resource type: index Space Weather : A Research Perspective Documents discussing space weather , the ...elements of near-Earth space, Earth-space meteorology and practical consequences of space weather . Glossary included. Author: National Academy of ...
The Joint Convention on the Safety of Spent Fuel management and on the Safety of Radioactive Waste Management is the first legal instrument to directly address the safety of spent fuel and radioactive waste management on a global scale. The Joint Convention entered into force in 2001. This paper describes its process and its main achievements to date. The perspectives to establish of a Global Waste Safety Regime based on the Joint Convention are also discussed. (authors)
We describe a 59-year-old patient who developed acute renal failure because of rhabdomyolysis after extensive red fire ant bites. This case illustrates a serious systemic reaction that may occur from...Full Text Available
Refractory ascites can occur in patients with various conditions. Although several procedures based on the reinfusion of ascitic fluid have been reported after the failure of bed rest, salt and water...Full Text Available
Forty-six patients with end-stage renal failure were subjected to iliac crest biopsy before the initiation of a dialysis programme and regardless of the presence of skeletal symptoms....Full Text Available
BackgroundThe rhizomes of Cynodon dactylon are used for the treatment of heart failure in folk medicine. In the present study, we investigated the effects of hydroalcoholic...Full Text Available
Angiotensin II has adverse actions in heart failure including vasoconstriction, aldosterone secretion, and activation of the sympathetic nervous system. Valsartan, a potent specific angiotensin II type 1 receptor blocker, may produce beneficial effects in heart failure. The purpose of this study was to evaluate the steady-state pharmacokinetics of valsartan 40, 80, and 160 mg each given every 12 h for 7 days in heart failure patients. Eighteen patients with chronic stable heart failure and left ventricular ejection fractions power model, showed that doubling the dose increased the AUC and Cmax 1.8 times. The pharmacokinetics of valsartan are predictable in heart failure patients within the dose range of 40-160 mg BID. Age did not appear to have influenced the valsartan clearance in heart failure patients. The pharmacokinetic values were higher in heart ...
A mechanistic understanding of fracture in human bone is critical to predicting fracture risk associated with age and disease. Despite extensive work, a mechanistic framework for describing how the underlying microstructure affects the failure mode in bone is lacking.
BackgroundAlthough dilated cardiomyopathy (DCM) is a leading cause of heart failure (HF), the mechanism underlying DCM is not well understood. Previously, it has been demonstrated...Full Text Available
Background:The cardiac sodium–calcium exchanger (NCX1) is a key sarcolemmal protein for the maintenance of calcium homeostasis in the heart. Since heart failure...Full Text Available
Premature menopause, ovarian failure younger than 40 years of age, is relatively rare but may preclude childbearing for some women who delay attempts at fertility. We present five kindreds in which...Full Text Available
AimsTo determine the effect of exercise training on clinical events and health-related quality of life (HRQoL) of patients with systolic heart failure.Methods...Full Text Available
ObjectiveThe aim of this study was to ascertain whether all cervical cancer patients who received adjuvant concurrent chemoradiation (CCRT) for high risk of treatment failure after...Full Text Available
There is limited information about the true incidence of acute renal failure (ARF). Most studies could not quantify disease frequency in the general population as they are hospital-based and...Full Text Available
The reliability of an electrical power system is influenced by the operation of circuit-breaker (CB). A good indicator of circuit-breaker condition is its switching time. Based on it some of the critical circuit-breaker irregularities can be detected and removed before they develop to a failure. In this paper, the evaluation of time measurements (timings) in case of different failures will be carried out for two circuit-breaker solutions, i.e. with spring and hydraulic drive. Moreover, the relationships between switching time and failure type/location will be derived. Thereby, the influence of failure trend will also be taken into account. (author)
Presented are the results of the investigation of the kinetics and micromechanism of the failure in impact bending of oriented-crystallized specimens having the eutectic composition Ni_3Al-Ni_3Nb and of the bimetal composed of 45 steel + M3 copper. The failure kinetics was studied by high-speed filming, whereas the fractures were studied by electron fractography. The particularities of the failure of the laminar-type composite materials were found. Analyzed was the effect of the kinetic factors and the mechanism of failure upon its energy consumption.
... with the additional US funds supporting Islamic ... the FATA and NWFP, keeping Pakistan's government and ... Without these madrassas, the TTP is left ...
Aluminum electrolytic capacitors, with 1043 failures, are a good example. Also, categorization by size and voltage reveals such frequencies of occurrence as ...
... which extend beyond the upper airway. These include attention deficit hyperactivity disorder, learning disorders, failure to thrive, and enuresis. Tonsillectomies ...
Stability concerns of the Par Pond Dam, an embankment structure in the Savannah River Site complex, resulted in a comprehensive evaluation of the state of its integrity. Specifically, excessive seepage through the embankment, slope failure due to an earthquake event as well as liquefaction potential of the embankment and the foundation are addressed and the potential of failure is evaluated. Lastly, remedial benefits of the addition of a berm structure are also assessed.
Heart failure goes beyond mechanical dysfunction and involves an interplay of multiple pathophysiologic mechanisms, including inflammation, tissue remodeling, neurohormonal and endocrine signaling, and interactions with the renal and nervous systems. This article highlights some novel biomarkers that may aid in diagnosis, treatment, and prognosis of acute heart failure, specifically focusing on ST2, endoglin, galectin-3, cystatin C, neutrophil gelatinase?associated lipocalin, midregional pro-adrenomedullin, chromogranin A, adiponectin, resistin, and leptin and their emerging clinical roles.
AimsThe prevalence and importance of liver function test (LFT) abnormalities in a large contemporary cohort of heart failure patients have not been systematically evaluated.Full Text Available
A case study is presented about the failure of a stainless steel blade reinforcing band in a steam turbine. The inspection results and analysis of samples of material are discussed. Being pitting corrosion and cracks the main defects found, a study of chemical composition and heat treatment state of the steel is made and findings are related to type of failure. (orig.)
1 The decreased binding of drugs and dyes to plasma proteins from male and female rats with acute renal failure has been investigated using equilibrium dialysis at 37 degrees C. 2 Acute renal failure...Full Text Available
The most typical kinds of corrosion of brasses are selective corrosion (dezincification) and stress corrosion. Prevention against these kinds of corrosion lies in application of arsenic alloy addition and appropriate heat treatment removing internal stresses as well as in maintaining the arsenic and phosphorus contents on a proper level. The most typical corrosion of cupronickels is the local corrosion. Selective corrosion occurs less often and corrosion cracking caused by stress corrosion in sea water does not usually occur. Crevice corrosion is found especially in places of an heterogeneous oxidation of the surface under inorganic deposits or under bio-film. Common corrosive phenomena for brasses and cupronickels are the effects caused by sea water flow and most often the impingement attack. Alloy additions improve resistance to the action of intensive sea water flow but situation in this field requires further improvement, especially if the cheaper kinds of ...
Most of previous study for creep rupture of RPV lower head under severe accident condition, have been focused on global failure of RPV lower head. In contract, the local failure of the RPV nozzle region has not been studied in detail. The existence and features of nozzle failure in LAVA-ICI specimen of KAERI and LHF-4 specimen of Sandia National Lab., are observed. It is confirmed that the nozzle failure of LHF-4 specimen is due to the hoop stress in the RPV. The tensile tests in various temperatures and the creep rupture tests in various temperatures and stresses, are accomplished. The finite element analysis for LAVA-ICI experiment was confirmed, and the stress and deformation analysis results are used in LAVA-ICI experiment. 17 refs., 34 figs., 3 tabs. (Author)
In the field of Living Probabilistic Safety Assessment (LPSA) the reliability data updating is an important factor. In risk analysis equipment failure data is needed to estimate the frequencies of events contributing to risk posed by a facility. Five years data of emergency diesel generator (EDG) of Daya Bay Nuclear Power Plant (NPP) has been studied in this paper. The data updating process has been done by using two methods, i.e., the classical method and Bayesian method. The aim of using these methods is to calculate the operational failure rate (@l) and demand failure probability (p). The results show that the operational failure rate is 1.7E-3 per hour and the demand failure probability is 2.4E-2 demand per day for Daya Bay NPP. By comparing the results obtain from classical and Bayesi...
Microelectronic failure analysis (FA) has been an integral part of the development of state-of-the-art integrated circuits. FA of MicroElectroMechanical Systems (MEMS) is moving from its infancy stage to assume an important role in the successful design, fabrication, performance and reliability analysis for this new technology. In previous work, the authors focused on the application of several techniques developed for integrated circuit analysis to an earlier version of a surface micromachined microengine fabricated at Sandia. Recently, they have identified important new failure modes in binary counters that incorporate a newer design of the microengine, using a subset of integrated circuit failure analysis techniques including optical microscopy, focused ion beam (FIB) techniques, atomic force microscopy (AFM), and scanning electron microscopy (SEM). The primary failure mode they have identified is ...
An anthropologist shares with the ?SNA and data mining community? his own anthropological perspective framed during more than five decades of network thinking about a broad range of anthropological problems. For 50?years he has viewed all people, things, and ideas in dynamic relationships. That perspective is a network perspective and at the same time anthropological, combining ethnographic, historical, holistic, and comparative views. It is valuable and beneficial to the community of scholars who use network analysis to try to understand what is going on, what went on before, and what the future prospects are. As an anthropologist, his interest is more in the wholes generated by network linkages?systems of households, bands, lineages, communities, corporations, governments?than in the ind...
Immunoassays are versatile analytical techniques that had a leading role in various clinical applications, during the last four decades. The studies carried out by Rosalyn Yalow, Solomon Berson and Roger Ekins in the 1960s gave a breakthrough in the development of this novel analytical method. Sensitivity up to femtomolar concentrations, high specificity and universal application to different classes of molecular species made immunoassay a very useful tool in analytical investigation. The expertise acquired by immunochemists in producing antibodies against any antigen and the ability of radiochemists in labeling the antigens with "1"2"5I without affecting the active site are the two main factors responsible for the above development. There are concerns about the safety and health of humans due to the high-level contamination of environment by pesticides, industrial compounds and metals, anabolic steroids in milk and meat products, and presence of mycotoxins in food and feed ...
This 2-page fact sheet gives statistics on routine waste generation and projected reduction by waste type, and 1994 pollution prevention and recycling accomplishments at ORNL.
ObjectiveTo estimate which strategy is the most cost-effective for prevention of preterm birth and associated morbidity.Study DesignFull Text Available
BackgroundThere has been substantial research on psychosocial and health care determinants of health disparities in the United States (US) but less on the role of modifiable risk...Full Text Available
BackgroundMost maternal deaths in developing countries can be prevented. China is among the 13 countries with the most maternal deaths; however, there has been a marked decrease...Full Text Available
Preventing tobacco use in youths may be an easier task than helping adults break the habit of smoking and overcome its ill effects. Using experimental procedures based on social work techniques,...Full Text Available
ObjectiveTo assess the efficacy and safety of low dose adrenaline injected subcutaneously to prevent acute adverse reactions to polyspecific antivenom serum in patients admitted...Full Text Available
High rates of human immunodeficiency virus (HIV) infection among jail and prison inmates suggest that HIV prevention efforts should focus on incarcerated populations. Overcrowding, the high prevalence...Full Text Available
BackgroundIn South Africa, HIV prevalence among youth aged 15-24 is among the world's highest. Given the urgent need to identify effective HIV prevention approaches, this review...Full Text Available
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
This paper aims to highlight ways in which basic research findings in the field of childhood and adolescent depression can help to inform and refine preventive intervention efforts. We selectively review...Full Text Available
This article describes process evaluation methods for the Pool Cool Diffusion Trial across four years. Pool Cool is a skin cancer prevention program that was...Full Text Available
sabot: A device fitted around or in back of a projectile in a gun barrel or launching tube to support or protect the projectile or to prevent the escape of ...
Vibration of machinery plays an important role in preventive maintenance programs of machinery. It can be applied in different phases ranging from simple to computerized programs. The advantages of applying machine condition monitoring programs are numerous since vibration measurement and analysis leads to the early detection of component deterioration. The cost, savings and some details of the vibration preventive maintenance program are discussed.
This Pollution Prevention Design Assessment (PPDA) provides data for cost-benefit analysis of the potential environmental impact of the APT, is an integral part of pollution prevention/waste minimization, and is required by DOE for any activity generating radioactive, hazardous, and mixed wastes. It will also better position the APT to meet future requirements, since it is anticipated that regulatory and other requirements will continue to become more restrictive and demanding.
The recent introduction of several transposable elements in zebrafish opens new frontiers for genetic manipulation in this important vertebrate model. This review discusses transposable elements as...Full Text Available
This study examined changes in the degree of positive bias in self-perceptions of previously-diagnosed 8 to 13 year-old children with attention-deficit/hyperactivity disorder (ADHD) (n=513)...Full Text Available
BackgroundWith a growing number of genetic tests becoming available to the health and consumer markets, genetic health care providers in Canada are faced with the challenge of developing...Full Text Available
A review is presented of the quest for superheavy elements under the following headings - early history; physical and nuclear properties unique to superheavy elements; searches in nature; terrestrial samples; extra-terrestrial samples; and searches at accelerators. 72 references. (U.K.).
A brief overview of the conceptual design of a solar central receiver system integrated with an existing cogeneration facility is provided. A synopsis of the performance and economic evaluation, and an assessment of the concept from the site owner's perspective are given.
The objective of the present research was to evaluate the physicochemical characteristics of berberine chloride and to assess the complexation of drug with 2-hydroxypropyl-β-cyclodextrin (HPβCD),...Full Text Available
Current drug treatments for post-menopausal osteoporosis cannot eliminate bone fractures, possibly because the mechanisms responsible for bone loss are not fully understood. Although research within...Full Text Available
The scope of our problems with nuclear waste management is outlined. Present and future inventories of nuclear wastes are assessed for risk. A discussion of what is presently being done to solve waste management problems and what might be done in the future are presented. (DC)
Although the heart rapidly adapts cardiac output to match the body’s circulatory demands, the regulatory mechanisms ensuring that sufficient ATP is available to perform the required...Full Text Available
Typical aircraft types supported include F4-Phantom, Tornado, MiG-29 ...... attempt to develop a theoretical explanation for learning phenomena [16]. ..... perspective, a primary reason for this is that an exponential curve approximates ...
User acceptance of a computer system depends on a number of factors, including broad social and professional concerns regarding the system's impact on the work environment. This observation is especially...Full Text Available
Electronic personal health records (ePHRs) can potentially maximize access and coordination of health information and improve patient/clinician collaboration, patient self-management, and health outcomes....Full Text Available
Life history theory proposes that early-life cues induce highly integrated responses in traits associated with energy partitioning, maturation, reproduction, and aging such that the individual phenotype...Full Text Available
Every year nearly 200,000 men in the United States are diagnosed with prostate cancer (PCa), and another 29,000 men succumb to the disease. Within certain regions of the world population based...Full Text Available
BackgroundSpecies with heteromorphic sex chromosomes face the challenge of large-scale imbalance in gene dose. Microarray-based studies in several independent male heterogametic...Full Text Available
BackgroundResearch has shown that the long term management of food allergy is suboptimal. Our study aims to provide direction for improvement, by evaluating food allergy management...Full Text Available
Colorectal cancer (CRC) survivors with ostomies can face complex concerns regarding sexuality. We used an anthropological perspective to examine the experiences of 30 female CRC survivors with...Full Text Available
The report summarizes the environmental significance of the priority pollutants being discharged from thirteen subcategories of the ore mining and dressing point source category. In addition, the impact of proposed effluent limitations guidelines is assessed from an environmental perspective.
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
... impact criterion, as demonstrated by the materials research community. These include training ... designing new materials or new processing/fabrication routes to existing materials; exploring and ...
Total health care expenditure in 2006 was $2.1 trillion. This figure is estimated to double within the next few years as the cost of treating diabetes and other chronic conditions continues to rise....Full Text Available
Most published estimates of the costs of the epidemic of human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) have been developed from the societal perspective,...Full Text Available
Prostatic neoplasms are not uniformly distributed within the prostate volume. With recent developments in three-dimensional intensity-modulated and imageguided radiation therapy, it is possible to treat...Full Text Available
Although the use of amphibole asbestos (crocidolite and amosite) has been banned in most European countries because of its known effects on the lung and pleura, chrysotile asbestos remains in use in...Full Text Available
Progressive obstructive lung disease is a characteristic component of cystic fibrosis (CF). It is the pulmonary manifestations, including obstruction and endobronchial infection, which directly contribute...Full Text Available
Carotid artery stenosis is a major risk factor for stroke, and treatments for this condition to decrease the risk of stroke include medical therapy, carotid endarterectomy (CEA), and, more recently,...Full Text Available
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
Malnutrition is common among older persons, with important consequences increasing frailty and morbidity and reducing health expectancy. On the contrary, calorie restriction (CR, a low-calorie dietary...Full Text Available
The aim of the overview is to give a perspective of global biobank development is given in a view of positioning biobanking as a key resource for healthcare to identify new potential markers that can...Full Text Available
Adaptive image processing is one of the most important techniques in visual information processing, especially in early vision such as image restoration, filtering, enhancement, and segmentation. This work focuses on applications of advanced CI techniques in image processing applications
BackgroundThe order Tetraodontiformes consists of approximately 429 species of fishes in nine families. Members of the order exhibit striking morphological diversity and radiated...Full Text Available
Neocortical columns are functional and morphological units whose architecture may have been under selective evolutionary pressure in different mammalian lineages in response to encephalization and specializations...Full Text Available
Risoe`s 40th anniversary was celebrated June 3, 1998 by a symposium held at Risoe. The interaction of research at Risoe with academia and industry was presented in both national and international perspective. Most of the presentations are in English, a few in Danish. (au)
This probabilistic analysis of WIPP TRUDOCK crane failure is based on two sources of failure data. The source for operator errors is the report by Swain and Guttman, NUREG/CR-1278-F, August 1983. The source for crane cable hook breaks was initially made by WIPP/WID-96- 2196, Rev. O by using relatively old (1970s) U.S. Navy data (NUREG-0612). However, a helpful analysis by R.K. Deremer of PLG guided the authors to values that were more realistic and more conservative, with the recommendation that the crane cable/hook failure rate should be 2.5 x 10-6 per demand. This value was adopted and used. Based on these choices a mean failure rate of 9.70 x 10-3(1/yr) was calculated. However, a mean rate by itself does not reveal the level of confidence to be associated with this number. Guidance to making confidence calculations came from the report by Swain and Guttman, who stated that ...
A troubling reality in today's political climate is that many political leaders actually believe that the best way to change schools is through an "end of a gun barrel" approach, rather than by building consensus. In this article, the author examines the reality of high-stakes testing from several perspectives, including the politics of coercion, politics of performance, and the politics of perception. The author discusses that high-stakes testing is a politically charged issue that has had a tremendous impact on the way schools operate; however, teachers must not be afraid to keep their perspective and must encourage a healthy, honest dialogue about the role of testing and engage in political debate.
The GERDA experiment is located in the underground Gran Sasso laboratory. The experiment aims at studying the neutrinoless ?? decay of 76Ge. The implementation of the experiment is divided in two consecutive phases. Phase I will allow within one year of data taking to reach a sensitivity limit for the half life of the process of the order of Formula Not Shown years. Phase II, with an increased amount of active material and a background index lower by one order of magnitude than in Phase I, will allow to reach a half life limit of about Formula Not Shown years. In the present paper a brief review of the status of the experiment and its perspectives is given.
Polyethylene gas piping is expected to be in service for times on the order of 50 years depending on service conditions. Therefore research research on piping materials and pipes has two principal objectives: (a) developing methods for predicting when a pipe will fail and (b) improving the material for piping. The prediction of long time failure hinges on the development of short time test methods which relate to long time failure. The improvement in the behavior of current materials also hinges on the use of test methods of short duration relative to the anticipated life time of the pipe in service. One of the primary criterion for an acceptable test method is that it produces the same type of failure as is observed after long time failure in service. It has been found that P.E. pipe material fails in a brittle mode after long periods of time. The failure mode is called brittle ...
The TS-1 and TS-2 TREAT transient experiments subjected a low burnup (2 MWd/kg) and a medium burnup (58 MWd/kg), respectively, FFTF irradiated fuel pin to unprotected 5 cents/s overpower transient conditions. The fuel pin failure response was similar in the two tests, which demonstrated a large margin to failure (P/P_0 > 3) and a favorable upper level failure location. Thus, for these transient conditions, burnup effects on transient performance appeared to be minimal in the range tested. Pin disruption in the medium burnup TS-2 test was more severe due to the higher fission gas pressurization, but failure occurred at only a 5% lower power level than for the low burnup TS-1 fuel pin. Both tests exhibited axial extrusion of molten fuel to the region above the fuel column several seconds before pin failure, demonstrating a potentially beneficial inherent safety mechanism to delay ...
Airborne pollutants can cause failures in switching and computing equipment. This paper focuses on a subset of such pollutants - airborne fine particles (<2.5 [mu]m diameter). It begins by examining the extent to which different improvements in heating, ventilating and air conditioning (HVAC) systems reduce indoor concentrations of fine particles. For each modification, the consequent reduction in soiling rate is derived. The concomitant increase in operating costs is also calculated. These costs are then compared with the costs of failures in telephone switching offices, leading to estimates of failure rate reductions that would make improvements cost-effective. Finally, the reduction in failures required to offset the costs of the improvements are compared with documented differences in failure rates between unimproved and improved environments. This study suggests that, in ...
This paper presents a method for the optimal design of high voltage transmission lines taking into consideration shielding and backflashover failure rates. The minimization of suitably defined performance indices, which relate the failures caused by lightning in a transmission line to both line insulation level and tower footing resistance, is aimed. Optimum values for both line insulation level and tower footing resistance are calculated. The method is applied on several operating Hellenic transmission lines of 150 and 400kV, respectively, carefully selected among others, due to their high failure rates during lightning thunderstorms. Special attention has been paid on open loop lines, where a possible failure could bring the system out of service causing significant problems. The obtained design parameters, which reduce the failure rates caused by lightning, are compared with the ...
Today`s industrial processes generate many types of waste products that constitute risks to human health and the surrounding environment. While proper waste management procedures can lower this risk, prevention of the waste`s generation will eliminate the risk. For this reason, the United States has established pollution prevention as a national objective, through the passage of its Pollution Prevention Act of 1990. Pollution prevention involves a wide range of approaches, all with the same objective: to reduce or eliminate the creation of waste at its source in other words, within the process that generates it. This objective, so beneficial to the environment, also coincides with industrial economic interests. Pollution prevention measures and greater process efficiency go hand in hand, and typically result in lower operating costs as well as greatly reduced waste management ...
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)
A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45({plus minus}5)% and 90({plus minus}5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author).
A wood/polymer composite was produced by impregnating Ramin wood with methyl methacrylate monomer and subsequently polymerizing it by gamma irradiation. To assess the improvement in compression strength of the wood caused by the polymer impregnation, a microbuckling compression failure mechanism was used to model the compression failure of the composite. Such a mechanism was found to predict a linear relationship between the compression strength and the percentage polymer impregnation (by weight). Uniaxial compression test results at 45(#+-#5)% and 90(#+-#5)% relative humidity levels, after being statistically analysed, showed that such a linear relationship was valid for up to 100% polymer impregnation. (author).
Oak Ridge National Laboratory (ORNL) has for over ten years provided materials testing and failure analysis services to various coal conversion and utilization facilities in the United States. ORNL was involved in these types of activities at all four of the major coal liquefaction pilot plants. This paper presents a summary of activities at Wilsonville over the past two and one-half years. Some details of these activities are discussed below. Failure analysis of elastomers, stainless steels, and alloys is discussed. 6 refs., 9 figs., 13 tabs.
The wind industry has experienced premature turbine component failures during the past years. With the increase in turbine size, these failures, especially those found in the major drivetrain components, i.e. main shaft, gearbox, and generator, have become extremely costly. Given that the gearbox is the most costly component in the drivetrain to fix, the National Renewable Energy Laboratory (NREL) initiated the Gearbox Reliability Collaborative (GRC) to determine the causes for premature gearbox failures and subsequently, recommend improvements to gearbox design, manufacture, and operational practices. The GRC has two identical test gearboxes, which are planned for a dynamometer and a field test, respectively.
There has been a steady increase in the number of revision total knee arthroplasties being performed in the United States. Hinge knee prostheses are used predominantly in complex primary or revision arthroplasties, often as salvage procedures. Significant improvement of the articulation between the rotating hinge mechanism and tibial component has decreased the stresses that contributed to earlier failures in previous generation designs. Two cases of fracture of the tibial metal post in the rotating hinge of a revision total knee arthroplasty were evaluated and treated at our institution within a 1-month period. We present our experience with this construct failure and subsequent patient management.
A fuel plate examination was conducted in the hot cell and canal to determine the possible failure modes for three plates leaking fission products. The plates were irradiated in the Extended Life Aluminide Fuel (ELAF) program in support of university research reactor goals to increase the limits presently allowed. The examination indicated pitting corrosion to be the failure mode. Other failure modes such as: (a) nonbonded swelling, (b) excessive fuel swelling, and (c) overheating of the plates were not observed.
of the Intelligent Control System (ICS) for reusable rocket engines. .... the incoming measurements with corresponding estimates, a sensor failure can be ...
Several randomized studies have been completed in prostate cancer that show a benefit to immediate postoperative treatment in patients undergoing prostatectomy. In one of the studies, there was even...Full Text Available
Mangroves are disappearing rapidly worldwide despite their well documented biodiversity and the ecosystem services they provide. Failure to link ecological processes and their societal benefits has...Full Text Available
The location of defective LMFBR fuel pins by the determination of gas tag isotopic ratios is discussed. The application of this method to the FFTF Reactor briefly described.
The coolant activity analysis to obtain the information about the fuel failure has been studied long before. And several codes have been developed to estimate the number of fuel failures through evaluating volatile and inert fission products release in coolant from the defective fuel. These codes use a fission product diffusion model coupled with a mass balance in the gap and coolant. But each code has a different model to assess fuel failure. In order to develop the model to estimate the number of fuel failures we analysis well-known code's models such as CHIRON, CADE, IODYNE, and CAAP and compare accuracy through Korean PWR activity data
Corrosion failures in circuits of foreign NPPs are considered. According to American statistics there are more corrosion failures in two-circuit NPPs than in NPPs with one circuit. Steam generators mostly suffer from ''corrosion denting''. Lately pitting corrosion becomes a potentially serious problem. Steam generator vertical tubes are mainly subjected to this corrosion type. Attention is drawn to intercrystalline corrosion. The causes of corrosion are described. The problem of optimization of structural materials is discussed to reduce corrosion failures as well as other methods of decreasing corrosion failures. Organization of nondestructive testing, increased requirements to water and steam purity are of great importance.
A general purpose Emergency Generator Set (EGS) is considered for a methodological study and related reliability behavior is analyzed. In particular in a procedure of reliability and availability analysis of a EGS, dependent failure events need a complex mathematical model as state-space model to be a accurately evaluated. Furthermore these dependent failure events are one of the most important reliability characteristic of EGS. This paper suggests a procedure for reliability calculations in presence of dependent failure based on the evaluation of a equivalent failure rate that can be fitted to a network reduction method by simple mathematical calculations. The simplified models analyzed show a good accuracy for a wide range of variation of main reliability characteristics of EGS and utility. The advantages obtained are very useful on reliability evaluation because the possibility of use of network ...
... position must not be penalized in their NCO Evaluation Report (NCOER). ... failure to perform MOS-, SQI-, or ASI-related duties after counseling. ...
The most frequent ultimate cause of death is myocardial arrest. In many cases this is due to myocardial hypoxia, generally arising from failure of the coronary macro- and microcirculation to deliver...Full Text Available
The AP-0 Target Hall Collection Lens is a pulsed device which focuses anti-protons just downstream of the Target. Since the angles at which the anti-protons depart the Target can be quite large, a very high focusing strength is required to maximize anti-proton capture into the downstream Debuncher Ring. The current design of the Collection Lens was designed to operate with a focusing gradient of 1,000 T/m. However, multiple failures of early devices resulted in lowering the normal operating gradient to about 750 T/m. At this gradient, the Lens design fares much better, lasting several million pulses, but ultimately still fails. A Finite Element Analysis (FEA) has been performed on this Collection Lens design to help determine the cause and/or nature of the failures. The Collection Lens magnetic field is created by passing high current through a central conductor cylinder. A uniform current distribution through the cylinder will create a ...
The failure of receivers has been one of the main operating problems at the White Cliffs solar thermal power plant. This Technical Note reports the results of an initial investigation that identifies the cause as having been their thermal fatiguing of the tube walls. The fatigue appears to be caused by unstable heat transfer at vapor qualities below the point where critical heat flux is generally exceeded. Methods for avoiding this problem are tested.
Failure of multiple components due to a common cause represents one of the most important issues in evaluation of system reliability or unavailability. The frequency of such events has relatively low expectancy, when compared to random failures, which affect individual components. However, in many cases the consequence is a direct loss of safety system or mitigative safety function. For this reason, the modeling of a common cause failure (CCF) and its presentation in fault tree structure is of the uttermost importance in probabilistic safety analyses (PSA). Amongst the different techniques available to reduce the impact of common cause failures, the most important operations related technique, is that of staggered testing. In the TAPP 3,4 Level-1 PSA it was found that the contribution of Common Cause Failures to the Core Damage Frequency (CDF) was significant. The Common Cause ...
The purpose of the Microelectronic Evaluation Laboratory at Sandia is to develop a program for evaluating CMOS LSI (complementary metal oxide silicon - large scale integrated) technology devices which are being used for the first time in a weapon system. These evaluations are based on accelerated aging studies and electrical tests to determine the reliability and life of the devices. In accelerated aging, specific, controlled stresses are applied to the device to accelerate time-to-failure. Data are used tin mathematical models to estimate life in acutal use. The stresses used for this technology are temperature and voltage. The devices are stored at temperatures with or without voltage applied (steady-state or cyclical) and periodically tested until at least 50% failures are encountered. Since most current technologies use epoxy-die-attachment, aging temperatures must be under 200/sup 0/C. This delays device failure, and a ...
Only a small number of radiation accidents in the United States have been severe enough to result in multi-organ failure (MOF). Medical details of selected medical misadministration and criticality cases are reviewed, with an emphasis on pathophysiology. The four criticality cases are particularly relevant for analysis of MOF, since medical treatment was supportive and did not appreciably alter the clinical evolution of radiation injury. PMID:15975871
This paper investigates the calculation of availability for parallel transmission lines (two or more) in the same tower or on the same right of way. As in many studies, the development of mathematical models is an important step. The models are justified using historical data and known characteristics of power system elements. A statistical method was used to generalize the failure rate and repair rate from real operating data. Application of the new model (which combines common-mode, simultaneous independent, and dependent outages) is discussed.
This report contains the results of a survey of reactor coolant pump shaft seal reliability. The survey sample is representatively large (approx. = 27% of total US commercial plant population) and includes the three industry seal suppliers (Bingham-Williamette, Byron Jackson, and Westinghouse). Operationally incurred/induced problems and seal redesign parameters are identified. Failure hypotheses in the form of fault trees have been developed to describe the failure mechanisms. Recommendations are made for seal reliability improvement.
The paper presents results of studies on the effect of heat treatment on strength and pattern of 40Kh steel impact failure. Loading levels corresponding to macroscopic spalling microdamage initiation in the material are determined for three initial states. Metallographic study on the spalling failure pattern for 40Kh steel in different initial states and data on microhardness measurement are presented.
Probabilistic assessment methods can be used to identify specific plant vulnerabilities. Application of such methods can also facilitate selection among system design alternatives available for safety enhancements. The quality of assessment results is however strongly dependent on realistic and accurate input data for modelling of system component behaviour and failure modes during conditions to be assessed. Use of conservative input data may not lead to results providing guidance on safety upgrades. Adequate input data for probabilistic assessments seems to be lacking for at least failure modes of some electrical components when exposed to a fire. This report presents an attempt to improve the situation with respect to such input data. In order to take advantage of information in existing documentation of fire incident occurrences some of the lessons learned from the fire at Browns Ferry Nuclear Power Plant on March 22, 1975 are discussed in ...
A historical overview of corrosion problems found in power plant condensers and mitigation procedures is presented. The paper is organized according to alloy type and failure mode. Alloys considered are copper-base alloys, stainless steels and titanium. Failure modes discussed include erosion-corrosion, sulfide attack, environmentally assisted cracking, galvanic corrosion, steam condensate corrosion, pitting corrosion, and dealloying. Mitigation procedures discussed include cathodic protection, ferrous ion injection, as well as tube cleaning and layup practices.
Power devices such as MOSFETSs and IGBTs, include parasitic structures that can give rise to destructive failures such as breakdown and latch-up. To determine a suitable strategy for device radiation hardening, simulation software like MEDICI-2D can be used to model the effects of technological modifications and device parameters that are difficult to measure experimentally. (authors).
Urinary tract infection (UTI) is a common problem in the female population. Women with diabetes mellitus are possibly at a higher risk. The usual medical therapy for UTI is antibiotic treatment. The aim of this study is to explore strategies employed by diabetic women for prevention and self-treatment of UTI. Forty-two women with diabetes mellitus who had experienced at least one episode of UTI in the last six months were included. Data collection included background information, questions about prevention and self-treatment strategies and a clinical examination to measure maximal urine flow, residual urine, a blood test evaluating diabetic control (HbA1c) and a urine test strip for determination of glucose, leucocytes, nitrite, blood, protein and pH. Thirty-five participants (83.3%) reported changes in daily routines like 'always keeping warm', 'increased fluid intake', 'good personal hygiene' as prevention strategies. ...
On February 9, 1995 ComEd experienced a pipe type cable failure on 138kV line 13717. Line 1737 is a bulk power transmission cable circuit connecting The Fisk and Crawford generating stations located within city limits. The line is approximately 4.5 miles long and was originally installed in 1975. This line is forced cooled, has 2,500 KCMIL copper conductors with 505 mils of paper insulation in an 8 inch pritec coated steel pipe. The splices are constructed with Voltalit castings. The failure occurred approximately 3,500 feet from Crawford Station. It was easy to locate the failure since the cable joint casing was breached resulting in the loss of approximately 2,600--2,700 gallons of dielectric fluid. Upon field examination B Phase was determined to have failed. The failure occurred 12 inches inside the casing in an area where it was impossible to install a long connector or add an additional short ...
Reliability has an impact on wind energy project costs and benefits. Both life test data and field failure data can be used for reliability analysis. In wind energy industry, wind farm operators have greater interest in recording wind turbine operating data. However, field failure data may be tainted or incomplete, and therefore it needs a more general mathematical model and algorithms to solve the model. The aim of this paper is to provide a solution to this problem. A three-parameter Weibull failure rate function is discussed for wind turbines and the parameters are estimated by maximum likelihood and least squares. Two populations of German and Danish wind turbines are analyzed. The traditional Weibull failure rate function is also employed for comparison. Analysis shows that the three-parameter Weibull function can obtain more accuracy on reliability growth of wind turbines. This work will be ...
A 25m wind turbine blade was tested to failure when subjected to a flapwise load. With the test setup, it was possible to test the blade to failure at three diffe-rent locations. The objective of these tests is to learn about how a wind turbine blade fails when exposed to a large flapwise load and how failures propagate. The report shows also results from ultra sonic scan of the surface of the blade and it is seen to be very useful for the detection of defects, especially in the layer between the skin laminate and the load carrying main spar. Acoustic emission was successfully used as sensor for the detection of damages in the blade during the test. The report contains measurements of the total deflection of the blade, the local deflection of the skin and the load carrying main spar and also measurement of strain all as a function of the applied load and up to failure of the blade. The 'post ...
A modified boundary element approach was used to analyze the response of offshore piles subjected to external soil movements. The computer model employed to solve the pile-soil problem was able to model pile head and tip loading, and loading caused by lateral movement of soil. A nonlinear pile-soil interface element with the ability to represent a hardening or softening plastic response prior to reaching an ultimate state was incorporated. With the program, 4 failure modes can be determined: flow of the soil slide past an intact stationary pile; rotation of the pile with the soil at failure along the full pile length; translation of the pile with the sliding soil, resulting in failure of the supporting soil; and the long-pile mode, in which the maximum bending moment in the pile reaches the yield moment of the pile before complete development of the other 3 modes. Theoretical solutions for a realistic hypothetical offshore ...
As part of the Nondestructive Evaluation Reliability Program sponsored by the US Nuclear Regulatory Commission, the Pacific Northwest Laboratory is developing a method that uses risk-based approaches to establish in-service inspection plans for nuclear power plant components. This method uses probabilistic risk assessment (PRA) results and Failure Modes and Effects Analysis (FEMA) techniques to identify and prioritize the most risk-important systems and components for inspection. The Surry Nuclear Power Station Unit 1 was selected for pilot applications of this method. The specific systems addressed in this report are the reactor pressure vessel, the reactor coolant, the low-pressure injection, and the auxiliary feedwater. The results provide a risk-based ranking of components within these systems and relate the target risk to target failure probability values for individual components. These results will be used to guide the development of ...
Object: To provide a tank, which can safely and reliably accommodate high temperature sodium containing radioactive substance in case of occurrence of an accident in a sodium system and thus prevent spread of contamination. Structure: A sodium drain duct inserted into a tank from above the tank is provided at the position of its lower end with a buffer means for preventing direct flow-down of sodium to a bottom plate. A means for preventing the discharge of radioactive substance to the cover gas is provided above the lower end of the sodium drain tube so as to surround the sodium drain tube. (Kamimura, M.).
Denial of service attacks (DoS) can cause significant financial damages. Flooding and Malicious packets are two kinds of DoS attacks. This paper presents a new security approach which stops malicious packets and prevents flooding in the critical systems. New concepts of packet stamp a dynamic-multi-communication-point mechanism has been identified for this proposed approach to make the prevention of flooding attacks easier and the performing of malicious packet attacks harder. In addition, dynamic key encryption technique has been adapted as a part of the proposed approach to enhance its functionality.
BackgroundOxidative stress has been proposed as a mechanism linking the poor placental perfusion characteristic of preeclampsia with the clinical manifestations of...Full Text Available
Vitamin D is now known to be of physiological importance outside of bone health and calcium homeostasis, and there is mounting evidence that it plays a beneficial role in the prevention and/or treatment...Full Text Available
Contagious diseases are a threat to animal health and productivity, both nationally and at the farm level. This makes implementation of biosecurity measures to prevent their introduction and...Full Text Available
IntroductionThe outbreak of cholera in Zimbabwe intensified interest in the control and prevention of cholera. While there is agreement that safe water, sanitation, and personal...Full Text Available
The precautionary principle has provoked a spirited debate among environmentalists worldwide, but it is equally relevant to public health and shares much with primary prevention. Its central components...Full Text Available
ObjectiveTo assess whether 17 alpha-hydroxyprogesterone caproate reduces the rate of preterm birth in women carrying triplets.MethodsFull Text Available
BackgroundA large and increasing part of the European population has a history of migration. Germany, for example, is home to about 15 million people with migrant background, which...Full Text Available
PurposeCataracts are often considered to be an unavoidable consequence of aging. Oxidative damage is a major cause or consequence of cortical and nuclear cataracts, the most common...Full Text Available
BackgroundMedication errors are common among inpatients and many are preventable with computerized prescribing. Relatively little is known about outpatient prescribing errors or...Full Text Available
News Jobs Grants/Funding Families Prevention Diseases Regulations Preparedness Mental Health and Traumatic Events Find Local Mental Health Services Information for: Parents and...
There's nothing that prevents us from being vigilant. In fact, freedom requires vigilance, and certainly our security in today's world requires vigilance. But one of the...
... used in our aluminum process include a barrier to isolate aluminum from the gold-based ohmic contacts, thereby preventing "purple plague," and a ...
Cellular senescence is an important mechanism for preventing the proliferation of potential cancer cells. Recently, however, it has become apparent that this process entails more than a simple cessation...Full Text Available
This Memorandum describes the following aspects of legionellosis: clinical presentations of legionella infection, general epidemiology (including nosocomial outbreaks and travel-associated legionnaires'...Full Text Available
With the spread of chloroquine resistant Plasmodium falciparum the control of malaria has become increasingly complex. In recent years, particular concern has arisen over how best to prevent malaria...Full Text Available
Chemical leucoderma is an industrial disorder in developed countries and the common causative chemicals are phenols and catechols. Due to stringent controls and preventive measures the incidence has...Full Text Available
Cells of the mononuclear phagocyte lineage have the capability to adhere to and fuse with each other and to differentiate into osteoclasts and giant cells. To investigate the macrophage adhesion/fusion...Full Text Available
The development of online communication systems related to prevention, decision making, and coping with cancer has outpaced theoretical attention to the attributes that appeal to system...Full Text Available
OBJECTIVE: To review the body of international literature regarding lung surfactant supplements in order to determine: 1) the current knowledge of the antenatal routes of administration of surfactant...Full Text Available
The role of apoptosis or programmed cell death in the regulation of development and maintenance of homeostasis in multicellular organisms is well established. During the last decade, naturally...Full Text Available
This work, carried out by the parliamentary office for the evaluation of scientific and technological choices on request of the French National Assembly and Senate, takes stock of the present day situation and technical perspectives of development of renewable energy sources and of research needs of the French industry in this domain: 1 - renewable energies: key-technologies for the energy supply of developing countries and for a rational consumption in transportation systems and accommodations of developed countries (energies technically different from fossil or nuclear energies; fundamental energy sources for a developing world; different national goals in Europe depending on the available natural resources and on the political realities; a minor interest in France for the domestic power generation but a major interest for transports, residential and tertiary sectors and export); 2 - priority choices given to the French renewable energy resources: renewable ...
The proceedings include the following lectures: Facing the challenges - new structures for electricity production. Renewable energies in Europe - chances and challenges. Nuclear outlook in the UK. Sustainable energy for Europe. Requirements of the market and the grid operator at the electricity production companies. Perspectives for the future energy production. Pumped storage plants - status and perspectives. Nuclear power/renewable energies -partners or opponents? New fossil fired power stations in Europe - status and perspectives. Nuclear energy: outlook for new build and lifetime extension in Europe. Biomass in the future European energy market - experiences for dong energy. Meeting the EU 20:20 renewable energy targets: the offshore challenges. DESERTEC: sustainable electricity for Europe, Middle East and North Africa. New power plants in Europe - a challenge for project and quality management. Consideration of safely ...
This paper reports the findings of a study that explores the perspectives of 25 young Cypriots regarding the symbolic values of smoking with respect to their everyday lived experiences. This study was motivated by recognising the high levels of smoking prevalence among adolescents in Cyprus and the absence of published research 'recording' their own versions of reality about smoking. Data for the study were generated from one-to-one qualitative interviews which encouraged the participants to articulate the symbolic value of smoking in their day-to-day experiences. The analysis focuses first, on the content of the embedded symbolic values of smoking (e.g. the quality of being 'cool') and second on the role of these values (e.g. used in projecting an image) in their everyday lives. A central...
Twitter introduced lists in late 2009 as a means of curating tweets into meaningful themes. Lists were quickly adopted by media companies as a means of organising content around news stories. Thus the curation of these lists is important, they should contain the key information gatekeepers and present a balanced perspective on the story. Identifying members to add to a list on an emerging topic is a delicate process. From a network analysis perspective there are a number of views on the Twitter network that can be explored, e.g. followers, retweets mentions etc. We present a process for integrating these views in order to recommend authoritative commentators to include on a list. This process is evaluated on manually curated lists about unrest in Bahrain and the Iowa caucuses for the 2012 US election.
The spectre of major climate change caused by the greenhouse effect has generated intensive research, heated scientific debate and a concerted international effort to draft agreements for the reduction of greenhouse gas emissions. This report of Scientific Perspectives on the greenhouse problem explains the technical issues in the debate in language readily understandable to the non-specialist. The inherent complexities of attempts to simulate the earth's climate are explained, particularly with regard to the effects of clouds and the circulation of the oceans, which together represent the largest factors of uncertainty in current global warming forecasts. Results of the search for the 'greenhouse signal' in existing climate records aredescribed in chapter 3 (part two). Chapter 5 (part two) develops a projection of 21st-century warming based on relatively firm evidence of the earth's actual response to known increases in greenhouse gas emissions during the last 100 ...
Wind power is a maturing technology that in a number of countries is likely to contribute a major share to fully renewable energy systems. Denmark has a comparably long history of wind power development and is planning to continue expanding the existing capacity. If a large-scale penetration of wind power is to be achieved, an integrated framework is needed that can respond to the associated challenges. This paper argues for adopting an integrated macro perspective when evaluating and building frameworks to support wind power development. This macro perspective is applied to the case of Denmark, and more specifically to concrete wind power projects in the region of Northern Jutland. The results suggest although certain elements in the legislation have been improved, the feasibility of wind power projects cannot be guaranteed, and there is a tendency to exclude smaller turbines from the development.
This study aimed to explore the impact of perceived service quality and self-concept on consumer attitude and purchase process using channel type (physical and Internet) as a segmentation variable. From the perspective of consumer behaviour, this study attempted to estimate a relational model and perform an empirical validation using female cosmetics and skincare products as an example. It was discovered that the influence of perceived service quality and self-concept on consumer attitude, purchase intention and behaviour, satisfaction, and loyalty varied with channel type. The analysis result revealed that physical stores presented higher levels of agreement with all research perspectives than Internet stores. However, only two relational paths have a higher influencing effect in physical...
Proteins are polymers of amino acids. These macromolecules are synthesized by intracellular machines called {\\it ribosome}. Although, traditionally, the experimental investigation of protein synthesis has been an active area of research in molecular cell biology, important quantitative models of this phenomenon have been reported mostly in the research journals devoted to statistical physics and related interdisciplinary topics. From the perspective of a physicist, protein synthesis is a phenomenon of {\\it classical transport of interacting ribosomes on a messenger RNA (mRNA) template} that dictates the sequence of the amino acids on the protein. Here we bring this frontier area of contemporary research into the classroom by appropriate simplification of the models and methods. In particular, we develope a simple toy model and analyze it by some elementary techniques of non-equilibrium statistical mechanics to predict the average rate of protein synthesis and ...
During the 1990's, natural gas was the energy source with the fastest rate of growth in the world energy balance. Nevertheless, recent evolutions of the energy context, in particular in terms of prices, have had a rather strong impact on the progress of the different energy sources penalizing gas a little. Beyond this competition between energies, which may increase, the medium-term perspectives of natural gas development is in keeping with an environment full of uncertainties. This article presents: the world supply and demand prospects for 2010-2015 (impact of high gas prices on other energy sources, occurrence of production constraints, political decisions of producing countries and world gas industry balance), trends on main markets (North America, Europe, Asia-Oceania), and international trade. (J.S.)
The shift to renewable energy options and low-carbon technologies, in response to the concerns over energy security and climate change, is proceeding more slowly than many would like. The usual argument against rapid deployment of new technologies is the costs imposed on the economy, commonly interpreted in terms of upfront costs to be borne or involving large cash transfers to fund, for example, efforts to preserve rainforests. In this contribution I argue that such a perspective provides a continuing barrier to taking effective action, whereas a perspective based on creation and use of carbon credits provides a means of avoiding the shock of abrupt industrial change. Carbon credits granted for bona fide carbon load reductions could be created through private initiative, for example by me...
The languages of the world exhibit a range of formal phenomena (e.g. accenting, syntactic reordering and morphological marking) that are commonly linked to the information-structural notion of focus. Crucially, there does not seem to be a one-to-one mapping between particular formal features (focus marking devices) and focus, neither from a cross-linguistic perspective, nor within individual languages. This raises the question of what is actually being expressed if we say that a constituent is focused in a particular language, and whether, or to what extent, the same semantic or pragmatic content is formally expressed by focus-marking across languages. This special issue addresses the question of focus and its grammatical realization from a number of theoretical and empirical perspectives....
Effective teamwork among station work groups is essential for plant production and safety in all phases of plant operation. To achieve effective teamwork, all contributing work groups must have ongoing access to and share a common perspective on station work priorities, and recognize how their individual contributions fit with and support the contributions of other groups in support of the larger station goals. Achieving and maintaining this alignment in perspective across all workgroups can be a challenge in large organizations. This paper discusses the experience at Darlington in building and maintaining station teamwork among the station workgroups in support of day-to-day plant operations. The issues encountered and the resource impacts of specific teamwork supporting practices adopted are outlined. (author)
Purpose - In light of the growth of internet usage and its important role in the field of e-commerce, electronic word-of-mouth (eWOM) has been changing people's behavior and decisions. People count on other users' opinions and information; they sometimes even make offline decisions based on information acquired online. The purpose of this paper is to conceptualise eWOM activity from an input-process-output (IPO) perspective; propose a classification framework based on the identified academic literature; analyze eWOM literature in terms of quantitative development and qualitative issues that are useful to both academics and researchers; and provide directions and guidelines for future research studies in eWOM. Design/methodology/approach - The authors performed a systematic literature revie...
Using Pd and Ag L3,2-edge x-ray-absorption near edge structures (XANES) and x-ray photoemission spectroscopy, we have investigated the charge distribution in a series of Pd-Ag alloys (Pd3Ag, PdAg, and PdAg3) from a local perspective. It is found that, relative to the pure element, both Pd and Ag gain d and lose non-d (s and p) charge upon alloying. The results are discussed in terms of band filling, rehybridization, electronegativity, and electroneutrality considerations. The possibility of using the L3,2-edge XANES white line to circumvent the need of an appropriate volume for charge transfer discussions and for other applications are noted.
In the aftermath of the 9/11 terrorist attacks on the United States, there was heightened interest worldwide in protecting nuclear power plants against intentional aircraft attack by terrorists. This paper presents our perspective into regulatory requirements for intentional aircraft crash that were set forth in foreign countries, including the latest rulemaking by the U.S. Nuclear Regulatory Commission (NRC), i.e., 10 CFR 50.54(hh) and 10 CFR 50.150 that have been made effective in May and July of 2009, respectively. In light of these international efforts to further enhance safety of NPPs, a study is also underway at the Korea Institute of Nuclear Safety (KINS) to establish an effective and efficient regulatory approach in consideration of the state of the art in this area
The study presented in this thesis is a contribution about the analysis of failures modes of electrolytic capacitors and thyristors. The studied components are main elements of the protection system of the superconductive magnets of the LHC. The study of the ageing of the electrolytic capacitors has shown that their reliability is strongly related to their technological characteristic. Evolution of their principal indicator of ageing (ESR) can be modeled according to different laws chosen according to their running mode. It appears that the prediction of failure of these components other than that due to wear can be only statistical taking into account the many causes of failure involving various modes of failure. In order to be able to evaluate influence of the ageing of the electrolytic capacitors on a system, simple models taking into account this parameters as well as the effective temperature of ...
Argonne National Laboratory (ANL) is implementing waste minimization and pollution prevention activities into its conduct of decontamination and decommissioning (D&D) projects. Many of these activities are rather straight forward and simple approaches, yet they are often overlooked and not implemented as often as they should or could be. Specific activities involving recycling and reuse of materials and structures, which have proven useful in lowering decommissioning and disposal costs on D&D projects at ANL are presented.
SummaryBackgroundInnovative prevention strategies for HIV-1 transmission are urgently needed. PRO2000 vaginal gel was efficacious against HIV-1 transmission in studies...Full Text Available
BackgroundWith 2.5 million new HIV infections per year, effective preventive methods against HIV are urgently needed, especially in sub-Saharan Africa. MDP301 is an ongoing trial...Full Text Available
... In order to produce organic livestock feed, feed mills must be inspected and certified. If they produce both organic and non-organic feed, they must implement procedures, backed up by records, to prevent the commingling of organic and non-organic feed. This includes steps to clean storage bins and mixing and bagging equipment prior to producing batches of organic feed. Organic feed mills also must prevent ...
BackgroundIntermittent preventive treatment of malaria during pregnancy (IPTp) is a key intervention in the national strategy for malaria control in Tanzania. SP, the current drug...Full Text Available
IAEA Plans of activities include, General Conference in September 2001 which reviewed activities relevant to preventing nuclear terrorism and proposed master plan. The Board of Governors approved new Nuclear Security Plan for the next four years. Three activity areas are; - needs assessment, analysis and coordination, prevention and detection and response.
BackgroundTo investigate the effects of a school-based physical activity-related injury prevention program, called 'iPlay', on risk behavior and neuromotor fitness.MethodsIn...Full Text Available
The method of the present invention comprises a step of previously coating a positive type resist on the surface of equipment, a step of solidifying the coated positive type resist and a step of bringing the coated equipment to circumstances for use and cleaning the positive type resist. With such procedures, the amount of radioactive materials deposited on the equipment can be reduced, and redeposition of nuclides on the surface to be cleaned can be prevented. (T.M.)
BackgroundMen who have sex with men (MSM) remain the group most at risk of acquiring HIV in the UK and new HIV prevention strategies are needed. In this paper, we examine what contact...Full Text Available
Delirium occurs in up to 65% of older hip fracture patients. Developing delirium in hospital has been associated with a variety of adverse outcomes. Trials have shown that multi-component preventive...Full Text Available
Customer Relationship Management (CRM) systems can help organizations manage customer interactions more effectively. Like many new technologies, CRM has been accompanied by vendor hype and stories of implementation failure. Work on critical success factors (CSFs) should encourage more appropriate implementation practice; however many CSF studies conclude with a list of factors but provide little further guidance. In particular, there is a need for stronger theoretical models of the entire CRM innovation process which can be used by managers to understand better the underlying causes of success and failure. This paper adopts a novel approach to this problem by firstly developing a conceptual model of CRM innovation and then converting this model into a dynamic simulation model. Some early s...
A series of six transient tests was performed on FFTF irradiated fuel pins to demonstrate their transient performance capability. The tests were performed in the TREAT reactor using sodium loops and instrumented test trains. The TEMECH computer code was used to design overpower transients which would simulate FFTF fuel pin thermal conditions during slow and fast unprotected transients. Some tests were run to substantial overpower levels but terminated prior to fuel pin failure, while other tests were intentionally extended to fuel failure to establish failure thresholds and characteristics. Post-test examination data provided significant cladding strain and fuel melting information used for performance code calibration and validation. These data showed that cladding damage caused by fuel melting is related to the steady state condition of the fuel.
The fatigue life variability of the #alpha#+#beta# titanium alloy, Ti-6Al-2Sn-4Zr-6Mo increased with decreasing stress level. The variability in life was found to be due to segregation of lives due to two failure mechanisms. A bimodal cumulative distribution model was shown to accurately describe the combined failure modes. The nominal failure processes for the two regimes were similar, with crack nucleation occurring in equiaxed #alpha#p particles, irrespective of life or stress level. However the variability in life was not controlled by the size of the crack-nucleating #alpha#p, but rather by the ability of the material to distribute deformation and avoid early crack nucleation.
The performance of steam generator tubes in water-cooled nuclear power reactors has been reviewed for 1979. Tube failures occurred at 38 of the 93 reactors surveyed. Causes of these failures and procedures designed to deal with them are described. The defect rate was twice that in 1978 but still lower than the two previous years. Methods being employed to detect defects include increasing use of multifrequency eddy-current testing and a trend to full-length inspection of all tubes. To reduce the incidence of tube failures by corrosion, plant operators are turning to full-flow condensate demineralization and more leak-resistant condenser tubes. (author).
The aim of the risk assessment consists of a comparative security evaluation for the SNR-300 and the PWR Biblis B. The failure analysis focusses on the reactor core; in addition, possible fission product release from the spent fuel pits is examined. By reliability analyses, the frequency of events leading to incidents is determined together with the probability of core destruction. In the accident analysis, the kind and frequency of failure of the activity barriers, i.e., primary system (reactorvessel) and inner and outer containment are investigated for the various incident sequences. The radionuclide release into the environment is classified into five different release categories. Besides internal failures, external causes (especially earthquakes and plane crashes) are considered under the aspect of their risk contribution. (RF).
Statement of problem Porcelain fracture associated with an implant-supported, metal ceramic crown or fixed partial denture occurs at a higher rate than in tooth-supported restorations, according to the literature. Implant-specific and patient-specific causes of ceramic failure have not been fully evaluated. Purpose The purpose of this retrospective study was to evaluate the potential statistical predictors for porcelain fracture of implant-supported, metal ceramic restorations. Material and Methods Over a 6-month period, a consecutive series of patients having previously received implant-supported, metal ceramic fixed restorations were examined during periodic recall appointments. The number of supporting implants, number of dental units, type of restoration, date of prosthesis insertion, ...
This paper presents a probabilistic approach for structural robustness assessment for a timber structure built a few years ago. The robustness analysis is based on a structural reliability based framework for robustness and a simplified mechanical system modelling of a timber truss system. A complex timber structure with a large number of failure modes is modelled with only a few dominant failure modes. First, a component based robustness analysis is performed based on the reliability indices of the remaining elements after the removal of selected critical elements. The robustness is expressed and evaluated by a robustness index. Next, the robustness is assessed using system reliability indices where the probabilistic failure model is modelled by a series system of parallel systems.
Reference failures, and their increase in affectively negative conditions (known as affective reactivity of speech), are more frequently observed in schizophrenia patients than in normal controls, but no information is available comparing schizophrenia with depression, ie, a mental disorder closely linked to the concept of affective reactivity. To address this gap in the literature, the present study compared 24 schizophrenia inpatients, 21 unipolar depression inpatients and 21 normal controls. Two 10-minute conversational speech samples (1 on negative and 1 on positive memories) were collected from each patient. The transcripts of the audiotaped interviews were analyzed blindly for frequencies of 6 types of referential failures, employing the Communication Disturbances Index, adapted for ...
Premature Failure of a Riata Defibrillator Lead. A 63-year-old woman with a St. Jude Medical Riata 1570 right ventricular lead complained of intermittent hiccups 2 months after implant. Interrogation revealed elevated pacing threshold and diaphragmatic stimulation. Pacing and shock lead impedances remained stable. No inappropriate sensing was noted. Fluoroscopic examination of the lead revealed a thin radio-opaque wire seen between the 2 defibrillator coils away from the main body of the lead. After extraction, a tear in the insulation of the lead was noted allowing the inner wire to protrude. This case illustrates a novel mechanism of insulation failure without inappropriate sensing or impedance change.-(J Cardiovasc Electrophysiol, Vol. 22, pp. 1070-1072, September 2011)
In general, macroscopic material failure is a manifestation of irreversible changes at the microscopic level. Many tissues, which may appear to be macroscopically homogeneous, are, at a fundamental microscopic level, a composite material. For example, cornea is composed of a hyaluronic acid matrix in which layers of collagen fibers are overlaid in a crossing pattern. The points where the collagen fibers intersect are potential nucleation sites for microscopic defects, which under the action of tensile stress, nucleate, grow and coalesce to form macroscopic failure planes, or spall planes. Using a model based on microstructural evolution, this paper examines the failure process during photoablation. Specifically, the paper describes a physically motivated, micromechanical model based on the nucleation and growth of spherical voids. This model is then used to simulate photoablation of cornea. Potential for using this model to ...
Twenty-two out of 31 patients with chronic renal failure and secondary hyperparathyroidism who underwent parathyroidectomy before operation underwent non-invasive image diagnosis of parathyroid glands by computed tomography (CT), scintigraphy with /sup 201/TlCl and /sup 99m/TcO/sup 4 +/, and/or ultrasonography. CT visualized 39 of 45 parathyroid glands (86.7%), weighing more than 500 mg. Scintigraphy with a subtraction method using a computer performed the diagnosis in 19 of 27 glands (70.4%). Ultrasonography detected 21 of 27 glands (77.8%). Image diagnosis was also useful in the postoperative follow-up study. The non-invasive image diagnosis of parathyroid glands in patients with chronic renal failure is thus valuable for 1) definite diagnosis of secondary hyperparathyroidism, 2) localization, and 3) diagnosis for effectiveness of conservative treatment.
An availability assessment of the principal systems of the Heber Geothermal Power Plant has been carried out based on the final issue of the process descriptions, process flow diagrams, and the approved for design P and IDs prepared by Fluor Power Services, Inc. (FPS). The principal systems are those which contribute most to plant unavailability. The plant equivalent availability, considering forced and deferred corrective maintenance outages, was computed using a 91 state Markov model to represent the 29 principal system failure configurations and their significant combinations. The failure configurations and associated failure and repair rates were defined from system/subsystem availability assessments that were conducted using the availability assessments based on the EPRI GO methodology and availability block diagram models. The availability and unavailability ranking of the systems and major equipment is presented.
The reliability analysis of the Fast Flux Test Facility reactor shutdown system was reevaluated. Failure information based on five years of plant operating experience was used to verify original reliability numbers or to establish new ones. Also, system modifications made subsequent to performance of the original analysis were incorporated into the reevaluation. Reliability calculations and sensitivity analyses were performed using a commercially available spreadsheet on a personal computer. The spreadsheet was configured so that future failures could be tracked and compared with expected failures. A number of recommendations resulted from the reevaluation including both increased and decreased surveillance intervals. All recommendations were based on meeting or exceeding existing reliability goals. Considerable cost savings will be incurred upon implementation of the recommendations.
The reliability analysis of the Fast Flux Test Facility reactor shutdown system was reevaluated. Failure information based on five years of plant operating experience was used to verify original reliability numbers or to establish new ones. Also, system modifications made subsequent to performance of the original analysis were incorporated into the reevaluation. Reliability calculations and sensitivity analyses were performed using a commercially available spreadsheet on a personal computer. The spreadsheet was configured so that future failures could be tracked and compared with expected failures. A number of recommendations resulted from the reevaluation including both increased and decreased surveillance intervals. All recommendations were based on meeting or exceeding existing reliability goals. Considerable cost savings will be incurred upon implementation of the recommendations.
The purpose of this project was to develop improved dynamic failure models for brittle materials (primarily ceramics). The approach to developing these failure models was to establish a database (ACERAM) in which fundamental material properties and processing information could be directly correlated with ballistic performance data. Under this contract, a comprehensive literature search was conducted, many contacts were established in the armor/anti-armor research and development community, and database development was undertaken. A more limited project was also undertaken to assess and compare the effects of material properties and penetration mechanisms on the ballistic performance of depleted uranium and tungsten alloy penetrators.
Analyses were performed of the safety-related performance of the reactor protection system (RPS) at U.S. Westinghouse and General Electric commercial reactors during the period 1984 through 1995. RPS operational data from these reactors were collected from the Nuclear Plant Reliability Data System (NPRDS) and Licensee Event Reports (LER). The common-cause failure (CCF) modeling in the fault trees developed for these studies and the analysis and use of common-cause failure data were sophisticated, state-of-the-art efforts. The overall CCF effort helped to test and expand the limits of the U.S. Nuclear Regulatory Commission's CCF methodology.
BackgroundAlthough self-expandable metal stent (SEMS) insertion is widely used for relief of malignant colorectal obstructions, the immediate technical and clinical failure rates of SEMSs and the associated risk factors remain largely unknown. ObjectiveTo identify rates and factors predictive of technical and clinical failure of SEMSs when their use is attempted for the decompression of malignant colorectal obstruction. DesignRetrospective chart review. SettingA tertiary-care academic medical center in South Korea. PatientsThis study involved a total of 412 patients with malignant colorectal obstruction in whom SEMS insertion was attempted. InterventionPlacement of colonic SEMSs. Main Outcome MeasurementsTechnical success and immediate and long-term clinical success rates. ResultsTechnical...
Elevated fatty acid levels have been thought to contribute to insulin resistance. Repression of the glucose transporter 4 (GLUT4) gene as well as impaired GLUT4 translocation may be a mediator for fatty acid-induced insulin resistance. This study was initiated to determine whether palmitate treatment repressed GLUT4 expression, whether glucose/fatty acid metabolism influenced palmitate-induced GLUT4 gene repression (PIGR), and whether attempts to prevent PIGR restored palmitate-induced impairment of glucose uptake (PIIGU) in C2 myotubes. Not only stimulators of fatty acid oxidation, such as bezafibrate, AICAR, and TOFA, but also TCA cycle substrates, such as pyruvate, leucine/glutamine, and ?-ketoisocaproate/monomethyl succinate, significantly prevented PIGR. In particular, supplementing with pyruvate through methyl pyruvate resulted in nearly complete prevention of PIIGU, whereas palmitate treatment reduced the ...
I discuss several examples of critical phenomena in O(N) models where topological excitations play an important role at criticality. I focus particular attention on the O(2) model in 3D, where recent measurements of the vortex string length distribution in equilibrium suggest the existence of a quantitative picture of the critical behavior in terms of defects. The compatibility of this perspective with renormalization group predictions is examined.
The results for development of methods and computer programs for integrated optimization of parameters of perspective fast reactors are given. The possibilities of the program for the reactor campaign calculation are analysed. This program is based on utilisation of the Bubnov-Galerkin method and Wigner disturbance theory. The possibility of application of approximation methods for the optimization researches is discussed. The results of development of the programs for complex reactor computations with account of control rods system and change of physical parameters in the reactor campaign are discussed. (author).
Current European and the US experiences in waste management are reviewed in the perspective of sustainable development. This publication questions the validity of the current approach taken by the Germany at ``closing the loop`` based on the example of packaging and packaging waste. The product item focus of current German legislation is compared with Danish and US approaches that are based on an integrated policy which covers the whole of waste generation and handling and is not product/item oriented. 1 fig., 2 tabs.
The petroleum and petroleum products increase offer a real development opportunity to the alternative fuels. In the context of the french energy accounting increase, the energy independence notion incites the government to promote these new fuels. If the LPG seems declining because of the accident risks fear, the fuel cell is not for today. Near these two sectors what is the future of the biofuels and the natural gas vehicle or the electric cars? (A.L.B.)
The transient enhanced diffusion in crystalline silicon implanted with dopants ad followed by high temperature annealing to activate the dopants is introduced. The physical mechanisms of transient enhanced dopant diffusion are then reviewed together with a short introduction to the proposed suppressing methods. Finally, the perspectives with using high energy heavy ions in this field are briefly discussed
The aim of this work is to suggest steps and policies to increase the introduction of cost-effective energy in conservation measures in Brazil. This report first addresses the motivations for a policy of energy efficiency and summarizes experiences in Brazil. It then considers the roles and perspectives of the diverse agents and review the instruments of policy. It concludes with an overview of strategic needs and lines of action.
The study of flavor changing neutrinos is a very active field of research. I will discuss the status of ongoing and near term experiments investigating neutrino properties at short distances from the source. In the next few years, the Double Chooz, RENO and Daya Bay reactor neutrino experiments will start looking for signatures of a non-zero value of the mixing angle $\\theta_{13}$ with much improved sensitivities. The MiniBooNE experiment is investigating the LSND anomaly by looking at both the $\
The CLARA-PRISMA setup, composed of an array of 25 Clover detectors placed at the target position of the magnetic spectrometer PRISMA, has recently concluded its campaign to study the structure of moderately neutron-rich nuclei. In this contribution, results obtained in the vicinity of the doubly-magic nucleus "4"8Ca are presented, together with results obtained for the heavy iron isotopes. The perspectives offered by the forthcoming operation of the AGATA Demonstrator Array coupled to PRISMA are also discussed. (author)
A historical summary is made on the measurements concerning the rising total hadron-hadron cross sections at high energies. The first part of this paper concerns the total cross section measurements performed at the Brookhaven, Serpukhov and Fermilab fixed target accelerators; then the measurements at the CERN Intersecting Storage Rings (ISR), and at the CERN and at the Tevatron Fermilab proton-antiproton colliders; finally the cosmic ray measurements at even higher energies. A short discussion on Conclusions and Perspectives follows.
This short article describes the strategies taken into consideration by the Swiss Federal Office of Energy for the promotion of renewable forms of energy in Switzerland. Two basic models are considered and the parts to be played by the Swiss Confederation, the Swiss Cantons, Energy Agencies and professional organisations are discussed. The importance of the activities of partner organisations and actor-networks in various areas such as solar, small hydro, geothermal and wind energy are discussed, as are models for financing the necessary promotion and marketing efforts
Food irradiation is the process of exposing food to an ionizing energy to kill harmful bacteria and other organisms and extend shelf-life. It is a safe process and has been approved by some 50 countries worldwide and applied commercially in the USA, Japan, China and several European countries for many years. Trends law regulations and new applications in Europe and another countries has been described. (author)
The proceedings of these seminars form an impressive chronicle of the continued progress in the understanding of refractory metals and cemented carbides and in their manufacture and application. The 15"t"h Plansee Seminar was convened under the general theme 'Powder Metallurgy High Performance Materials'. Under this broadened perspective the seminar will strive to look beyond the refractory metals and cemented carbides, which remain at its focus, to novel classes of materials, such as intermetallic compounds, with potential for high temperature applications. (boteke)
...Pharmaceutics | Special Issue: Solid Dosage Forms LoginRegister mdpi.com Journals A-Z For Authors About Open Access Policy Title / Keyword Journal all Administrative Sciences Agriculture ...Establishing Differences from Adults Recent Developments and Future Perspectives in Dissolution Testing Solid Dosage Forms The 1st Electronic Conference on Pharmaceutical Science The Progress on Pharmaceutics ... 1 (2009) Special Issue \\
ObjectivesObjectives Not AvailableDescriptionOne significant research challenge posed by the growing number of older people in the population concerns the mobility-related problems which increase with age, inhibit independence, and can be a prime cause of admission to expensive institutional settings. The scope for engineering advances, particularly in the field of rehabilitation and assistive technology, is immense. The challenge is to produce aids, devices and products that are attractive to older people themselves, since without such [continued...
The development of our understanding of the quantum states of nuclei is viewed from a historical perspective. The characteristics of nuclear energy levels are presented, and interpretations of these excitations in terms of simple vibrational and rotational modes are presented. The application of energy level schemes in a variety of fields is briefly summarized. (author). 18 refs., 7 figs.
rapid rise in intensive production (particularly intensive pig and poultry production ) much of the expansion in land ...than extensively reared ruminant production, and intensive pig and poultry production is, by a long way, ...In short, intensive pig and poultry production can be seen, from this perspective, as the
Several new development trends in the processing of methanol to various chemical products are discussed. The production of acetic acid by carbonylation of methanol will increase. In the future, methanol is expected to represent the raw material in the production of lower alkenes. The synthesis of lower alcohols, of synthetic gas (homologation), and of aromatic hydrocarbons from methanol are in the research stage.
This one-day TOPTEC session began with an overview of hybrid electric vehicle technology. Updates were given on alternative types of energy storage, APU control for low emissions, simulation programs, and industry and government activities. The keynote speech was about battery technology, a key element to the success of hybrids. The TOPEC concluded with a panel discussion on the mission of hybrid electric vehicles, with a perspective from industry and government experts from United States and Canada on their view of the role of this technology.
To seek for a promising concept of a heavy liquid metal coolant (HLMC) fast reactor plant, Japan Nuclear Cycle Development Institute (JNC) and the electric utilities conducted conceptual design study on various types of plant concepts and compared these concepts based on technical feasibility and economical perspective. The Pb-Bi cooled complete natural circulation reactor concept may attain high safety level and construction cost goal (Yen 200,000/kWe) (authors)
Germanium coordination compounds (GCC) with oxiethilidendyphosphonic acid (Ge-Oedph) film structures electrophysical, optical, structural and adsorptive properties investigation results are represented. This structure concerns to a new perspective class of functional materials. The mechanism GCC films electric conductivity is investigated and explained. GCC possible application fields are specified.
Germanium coordination compounds (GCC) with oxiethilidendyphosphonic acid (Ge-Oedph) film structures electrophysical, optical, structural and adsorptive properties investigation results are represented. This structure concerns to a new perspective class of functional materials. The mechanism GCC films electric conductivity is investigated and explained. GCC possible application fields are specified.
To assist in attaining the HSE's objective of providing perspective and focus for Safety Case Assessment, a generic model of the structural design process for the foundations of pile supported fixed steel structures has been developed. Interfaces between the foundation design team and other stakeholders have been identified and assessments made of both the magnitude and the potential significance of the uncertainties associated with key elements of the design process. (author)
The Flux Mapping System (FMS) of 540 MWe PHWR is a system, which is first of its kind used in Indian PHWRs. It is used to compute a detailed flux/power distribution of the reactor core using modal synthesis method .The paper brings out the high availability features of FMS and the software design philosophy. The paper emphasizes on framework based reusable architectural design, which simplifies and speeds up the development of data acquisition systems. (author)
EREC, the international umbrella organization, published last year a study on export strategies for renewable energy technologies. The 150-page document provides valuable information on key export markets and financial institutions, and presents the various branches' perspectives for the future. The following excerpts will whet your appetite for more. The complete study is available for download: www.erec-renewables.org (Eurees). (orig.)
In November 1998, President Clinton charged the National Bioethics Advisory Commission with the task of conducting a thorough review of the issues associated with human stem cell research, balancing all ethical and medical considerations. The President's ...
The objective of this study was to identify and assess the present and future dimensions of environmental effects and impacts of various energy generation alternatives, and to place safety and environmental risks associated with the nuclear industry in Canada in perspective with the risks from other sources. It was found that nuclear power generation involves a comparable risk to that of conventional methods of thermoelectric power generation.
Since the oil prices decreased during June 2008, many uncertainties drive the energy markets. The author aims to analyze the future battles around the the dying resources, taking into account that the alternatives sources will need time to develop. The author analyzes also the relation energy and climate in the preservation of the fundamental equilibrium. (A.L.B.)
The critical concentrations correspond to contamination thresholds of environments over which noxious effects can occur and deteriorate soils, water and vegetation. They are defined according to the type of pollutants and their mode of action. The aim of this document is to provide a scientific framework to the policies of reduction of atmospheric pollution negotiated at Geneva`s convention. The methodology of evaluation, the results obtained for surface waters and forest soils, the perspectives of French research and the integration of French knowledge in the European database are presented. (J.S.)
Convergenomics is about the megatrends that are shaping how people behave and organizations work. In this insightful analysis, Sang Lee and David Olson describe how globalization, digitization, changing demographics, changing industry mix, deregulation and privatization, commoditization of processes, new value chains, emerging new economies, deteriorating environment, and cultural conflicts have led to what they define as a convergence revolution.Lee and Olson discuss this convergence revolution from the perspectives of technology, industry, knowledge, open-source networking and bio-artificial
This apper discusses whether health risks are associated with exposure to electromagnetic fields that exist beneath high-voltage transmission lines. This is a question receiving increasing attention as the electric utility industry prepares to supply its customers with increased amounts of electric power. 26 refs.
This paper describes the effects of motion of beam components (quads, rf cavities and dipoles) on the beam and considers the properties of a compensation system from the perspective of users. The system departs from standard practice in considering active perturbation of the electron beam to verify beam corrections. The effects of local closed orbit perturbations to direct undulator beams at different experimental setups are also considered.
Surveillance of a population, such as a weapon stockpile, is needed to discover manufacturing defects as well as deterioration as the population ages. This article considers the risks of sampling rates for surveillance from three perspectives: detection probability of defects in a proportion of a population with pass/fail data, detection of a trend in a defective proportion of the population with pass/fail data, and detection of a trend with quantitative degradation measurements. Understanding of these risks will help the decision maker choose a sampling rate to protect against such problems of a specified size at a tolerable risk.
We propose a system for the on-line monitoring of short and medium term radioactive waste repositories. Such a system is distributed, fine-grained, robust, reliable, and must be based on low-cost components. It could, in principle, open new perspectives on the modality of waste packaging and storage. In particular we propose to employ a new family of cheap and powerful micro sensors to be placed in shape of a fine grid around each single drum. (authors)
British Nuclear Fuels (BNFL) is currently operating its third generation of nuclear plant for the management of irradiated nuclear fuel. Development for the fourth generation plant must meet requirements for processing higher burn-up fuel with lower unit costs, lower environmental impact, better process control, and more flexible control of actinides. .
... Further information For more detailed information on available accommodation, refer to our housing guide At home with us, visit Residential Services, or contact : T +44 (0)1273 678220 E housing@sussex.ac.uk Davidrsquo;s perspective lsquo;When my wife and I decided to study at Sussex, we applied for University accommodation. We were delighted with the lovely self-contained flat on Clifton Road in Brighton that we got via the Housing Office. ...
BackgroundModern metal-on-metal hip resurfacing implants are being increasingly used for young and active patients, although the long-term outcome and failure mechanisms of these...Full Text Available
Albeit the considerable progress that has been made both in our understanding of the pathophysiology of acute renal failure (ARF) and in its treatment (continuous renal replacement therapies), the morbidity...Full Text Available
HIV-1 nonsubtype B variants account for the majority of HIV infections worldwide. Drug resistance in individuals who have never undergone antiretroviral therapy can lead to early failure and...Full Text Available
In a group of 32 patients with terminal renal failure the initial hypocalcaemia was corrected after two months' adequate maintenance haemodialysis. In seven patients hypercalcaemia occurred with a...Full Text Available
BackgroundIsoproterenol-induced cardiac hypertrophy in mice has been used in a number of studies to model human cardiac disease. In this study, we compared the transcriptional response...Full Text Available
Background and purpose It has been speculated that the prevalence of metal allergy may be higher in patients with implant failure. We compared the prevalence and cause of revisions following...Full Text Available
Aging is a risk factor for heart failure, which is a leading cause of death world-wide. Elderly patients are more likely than young patients to experience a myocardial infarction (MI) and are...Full Text Available
BackgroundThere is a strong inverse relationship between final vessel diameter and subsequent risk of treatment failure after coronary stent deployment. The aim of this study was...Full Text Available
Progress is reported in the following areas: radioactivity control technology, FFTF sodium characterization system, corrosion and process control, and fuel failure monitoring systems for FFTF and CRBRP. (JWR)
Xylem failure via gas embolism (cavitation) induced by water stress was investigated in the palm Rhapis excelsa (Thumb.) Henry. Xylem embolism in excised stems and petioles was detected...Full Text Available
Acetaminophen (APAP) toxicity is the most common drug-induced cause of acute liver failure in the United States. The only available treatment, N-acetylcysteine (NAC), has a limited...Full Text Available
It is well known that the lightning protection of transmission lines is exclusively relying on their correct initial design. Although detailed engineering studies are usually performed by electric power utilities for the design of new transmission lines, there are reported cases where the design is based simply on tradition or on utilities' standardization policy. In this paper, the lightning protection of high-voltage transmission lines is faced as an optimization problem where optimum design parameters are calculated for the lines, relating their cost with the lightning failures' cost, aiming to reduce or even eliminate lightning failures. The optimization method considers all the available protection means, i.e. ground wires and surge arresters. In order to validate the effectiveness of the proposed method, it is applied on several operating Hellenic transmission lines of 150 kV carefully selected among others due to their ...
The pharmacokinetic parameters of amikacin and ceftazidime were assessed in four patients undergoing hemofiltration for septic shock. The parameters were assessed during hemofiltration and in the interim...Full Text Available
Bone remodeling is necessary to avoid microdamage accumulation, which could lead to whole-bone failure. Previous studies have shown that this bone-repair mechanism is triggered by osteocyte apoptosis....Full Text Available
BackgroundGene expression profiling and the analysis of protein-protein interaction (PPI) networks may support the identification of disease bio-markers and potential drug targets....Full Text Available
Serial studies of iron transport in patients on maintenance dialysis showed normal or raised values in almost all subjects and a transient increase soon after the start of dialysis in three. These...Full Text Available
The presence of DNA-anti-DNA complexes in sera from patients with systemic lupus erythematosus (SLE) was investigated by two new radioimmunoassays (RIA) developed for this purpose and by measuring the...Full Text Available
AIMS:To investigate the effect of carnitine supplementation on alcoholic malnourished rats' hepatic nitrogen content.METHODS:Malnourished rats, on...Full Text Available
ObjectivesThis studys examined the relationship between substance use disorder (SUD) and intimate partner violence screening (IPV) and management practices in the...Full Text Available
In this paper, an investigation was performed on a failure pressure vessel, which was as an anti-freezing heater for General Gas Storage and Distribution (SGZ) system. Evident and serious deformation was observed on the body of the vessel. A metallurgical investigation was conducted to establish the mechanism and cause of deformation of the anti-freezing heater at Daya Bay PWR station in China. The investigation, which was performed on specimens cut from the most serious area deformed of the vessel, included macroscopic examination and microscopy examination. The results of the examinations showed that some lamellar pearlite in the microstructure were already spheroidized. It was confirmed that the vessel was operated at high temperature. Stress analysis for the vessel was conducted. And it was confirmed that, in ideal conditions, the vessel would be deformed at around 420 C. The overall results of the investigation showed that the failure of ...
The probabilistic external events analysis performed for the Savannah River Site K-reactor PRA considered many different events which are generally perceived to be external'' to the reactor and its systems, such as fires, floods, seismic events, and transportation accidents (as well as many others). Events which have been shown to be significant contributors to risk include seismic events, tornados, a crane failure scenario, fires and dam failures. The total contribution to the core melt frequency from external initiators has been found to be 2.2 {times} 10{sup {minus}4} per year, from which seismic events are the major contributor (1.2 {times} 10{sup {minus}4} per year). Fire initiated events contribute 1.4 {times} 10{sup {minus}7} per year, tornados 5.8 {times} 10{sup {minus}7} per year, dam failures 1.5 {times} 10{sup {minus}6} per year and the crane failure scenario less than ...
The nephrotoxicity of cefoxitin was studied in a rat model of impaired renal function. Two levels of renal impairment were produced: "moderate," with blood urea concentrations of 100 to 150 mg/100 ml...Full Text Available
A micro-mechanistic understanding of bone fracture thatencompasses how cracks interact with the underlying microstructure anddefines their local failure mode is lacking, despite extensive research nthe response of bone to a variety of factors like aging, loading, and/ordisease.
Present methods for planning reliability improvement of launch vehicles are reviewed. A theoretical criterion for optimum allocation of resources for reliability improvement exists that requires equal marginal failure reduction for all elements to be impr...
The goal of this study was to evaluate topics used to troubleshoot circuit boards with known or suspected thermally intermittent components. Failure modes for thermally intermittent components are typically mechanical defects, such as cracks in solder paths or joints, or broken b...
Acetaminophen (APAP), a widely used analgesic and antipyretic that is considered to be relatively safe at recommended doses, is the leading cause of drug-induced liver failure in the United States....Full Text Available
The performance of more than 3,000 offshore platforms in the Gulf of Mexico was observed during the passage of Hurricane Andrew in August 1992. This event provided an opportunity to test the procedures used for platform analysis and design. A global bias was inferred for overall platform capacity and loads in the Andrew Joint Industry Project (JIP) Phase 1. It was predicted that the pile foundations of several platforms should have failed, but did not. These results indicated that the biases specific to foundation failure modes may be higher than those of jacket failure modes. The biases in predictions of foundation failure modes were therefore investigated further in this study. The work included capacity analysis and calibration of predictions with the observed behavior for 3 jacket platforms and 3 caissons using Bayesian updating. Bias factors for two foundation failure modes, lateral shear and ...
Research is in progress to obtain a satisfactory creep ductility for alloy 800 when used as heat exchanger material in sodium-cooled fast reactors (LMFBR). The creep test characteristics at present available show that a pronounced tendency to reduced elongation by creep failure may arise after prolonged testing in the 500-700 deg C temperature range. This phenomenon is now agreed to be primarily inherent to the conditions for Ni_3(Ti,Al) precipitation in the material and hence to the Ti and Al concentrations. By structural studies and hardness measurements on material subjected to creep tests and taken from a large number of castings, the relationship was established between the (Ti+Al) content and the structural hardness effect of Ni_3(Ti,Al) at 600 deg C. Below a certain Ti+Al concentration, no precipitation occurs and hence the creep ductility to failure can be improved considerably by limiting the allowed Ti+Al content in the material, ...
Myocarditis, often initiated by viral infection, may progress to autoimmune inflammatory heart disease, dilated cardiomyopathy and heart failure. Although cardiac myosin is a dominant autoantigen...Full Text Available
BackgroundThe elevated serum and peritoneal cytokine concentrations responsible for the systemic response syndrome (SIRS) and multiorgan failure in patients with severe acute pancreatitis...Full Text Available
The measurement of bone loss in patients undergoing maintenance dialysis over a period of two and a half years is reported. The tendency to lose bone is a likely event in renal failure, but depends...Full Text Available
Failure of bone under monotonic and cyclic loading is related to the bone mineral density, the quality of the bone matrix and the evolution of microcracks. The theory of linear elastic fracture...Full Text Available
Background: The causes of elevated B-Type natriuretic peptide (BNP) levels are multifactorial. Renal dysfunction has been shown to affect BNP levels in some studies and...Full Text Available
Evaluating the systolic function of the left ventricle (LV) is important in the hemodynamic management of the critically ill patients with circulatory failure. Echocardiography is considered the standard...Full Text Available
Anxiety may cause adverse outcomes through physiologic pathways in patients with cardiac disease. The purpose of this dissertation was to investigate anxiety and its correlates in persons with acute myocardial infarction (AMI) and heart failure (HF). The ...
The free radical theory of ageing posits that accrual of oxidative damage underlies the increased cellular, tissue and organ dysfunction and failure associated with advanced age. In support of this...Full Text Available
A case of severe intractable angina pectoris with normal angiography is presented. Following video assisted thoracic sympathectomy the patient died of heart failure. Microvascular cardiac amyloidosis...Full Text Available
ObjectiveThe purpose of this study is to identify the factors affecting the failure of trials (<50% pain reduction in pain for trial period) to improve success rate of spinal...Full Text Available
BackgroundMale infertility is a common cause of reproductive failure in humans. In mice, targeted deletions of the genes coding for FKBP6 or FKBP52, members of the FK506 binding...Full Text Available
Due to the recent catastrophic energy system failures in California along with those in the North-Eastern US and Southern Canada, London, and Italy, the time has come to proclaim the failure of deregulation, privatization or liberalization and propose a new energy system. This book shows in the first section, how five precipitating forces led to the deregulation debacle in California: (1) major technological changes and commercialization, (2) regulatory needs mismatched to societal adjustments, (3) inadequate and flawed economic models, (4) lack of vision, goals, and planning leading to energy failures, and (5) failure and lack of economic regional development. The second half of the book, examines how 'civic market', new economic models, and planning for complexity as sustainable economic development transformed in California, the same five forces to create an 'agile energy ...
Congenital diaphragmatic hernia (CDH) is described as (1) failure of diaphragmatic closure at development, (2) presence of herniated abdominal contents into chest and (3) pulmonary hypoplasia. Usually,...Full Text Available
Procedures for {sup 131}I ablation in renal failure are not known. In one patient receiving dialysis, detailed dosimetry and health safety aspects were obtained. The results showed insignificant contamination of equipment, but a surprisingly significant reduction in biologic half-life of {sup 131}I due to efficient dialysis extraction. The data indicate that {sup 131}I ablation can be done safely and easily during dialysis but that much higher {sup 131}I doses must be used to achieve equivalent results to those obtained in patients with normal renal function.
Based on a detailed analysis of the inter-relationship in the current, voltage, electromagnetic torque and ratio of the difference between the speed of rotor and the speed of rotary magnetic field to the later in the motor, the root cause was point out, which leads to the protection fuses' failure of the motor in the starting stage, which drives the turbine-generator set to rotate at low speed before its startup. Two solutions to avoid the situation are proposed, too. (authors)
High strain fatigue problem in steam turbine. Cyclic stress strain hysteresis loops and stress relaxation behaviour in 16 h dwell period tests. Variation of stress and strain during tests under nominally strain controlled conditions. Definition of test conditions and of criteria for crack initiation and failure. Comparison of reverse bend and push pull failure data. (orig.) 891 RW/orig. 892 RKD.
The TS-1 and TS-2 Transient Reactor Test Facility (TREAT) experiments were conducted on irradiated Fast Flux Test Facility (FFTF) fuel pins to characterize their failure behavior when subjected to hypothetical 5%/s transient overpower conditions. The TS-1 test employed a near-fresh (2 MWd/kg) fuel pin, while the TS-2 test used a medium-burnup (58 MWd/kg) fuel pin. Transient conditions were closely matched between the two experiments to provide a direct comparison of burnup effects on the failure response.
Analytical models for predicting the deformation and failure of composite sandwich panels subjected to blast and projectile impact loading are presented in this paper. The analytical predictions of the transient deformations and damage initiation in the composite sandwich panels were compared with finite element solutions using ABAQUS Explicit. For the blast model, the predicted transient deformation of the sandwich panel was within 7%of FEA results, while the predicted damage initiation using Hashin's composite failure criteria was about 15%higher than FEA results in most cases. For the high velocity impact model, the predicted transient deformations were within 20%of FEA results.
Tube failures due to excessive flow-induced vibration must be avoided to assure the reliable performance of heat exchangers. Such components must be thoroughly analysed for vibration at the design stage. Several flow-induced vibration mechanisms are possible. In this paper, particular attention is given to fluidelastic instability of tube bundles subjected to liquid and two-phase cross-flow. The performance of ten operating heat exchanger components is reviewed to validate our recommended vibration analysis guidelines. Both tube failure histories and satisfactory performances are considered. The results show that a fluidelastic instability constant K=3.3 is a reasonable design criterion. (auth).
The nitric acid solution dissolving nuclear fuel material is transferred with the three way valve called VCV (VCV: vide-casse-vide in Fr.) using vacuum in the Tokai Reprocessing Plant. The initial VCV was not reliable because it had broken with in 1 or 2 years. The cause of failure was damage of the plastic diaphragms in the moving parts. Then, the new VCV valve with stainless-steel bellows was developed. There is no failure in moving parts in 20 years, therefore reliability is significantly improved. (author)
A large amount of radioactive waste has been stored safely at the Savannah River and Hanford sites over the past 46 years. The aim of this report is to review the experimental corrosion studies at Savannah River and Hanford with the intention of identifying the types and rates of corrosion encountered and indicate how these data contribute to tank failure predictions. The compositions of the High-Level Wastes, mild steels used in the construction of the waste tanks and degradation-modes particularly stress corrosion cracking and pitting are discussed. Current concerns at the Hanford Site are highlighted.
From the beginning, one of the most useful applications of Probabilistic Safety Assessment (PSA) is its use in evaluating the risk importance of changes to plant design, operations, or other plant conditions. Risk importance measures the impact of a change on the risk. Risk is defined as a combination of the likelihood of failure and consequence of the failure. The consequence can be safety system unavailability, core melt frequency, early release, or various other consequence measures. The goal in this PSA application is to evaluate the risk importance of an ISI process, as applied to plant piping systems. Two approaches can be taken in this evaluation: Current PSA Approach or the Blended Approach. Both are discussed here.
An integrated approach to the modelling of hydrogen assisted failure in 316L steel is presented. The approach includes experimental, fractographic, numerical and theoretical analysis of the phenomenon. The physical adequacy of the mechanical models of hydrogen embrittlement (notch extension model and notch cracking model) is discussed by comparing the virtual damage depth (theoretical) predicted by the models with the embrittled zone (microphysical) measured in the fractographic analysis by scanning electron microscopy. In addition, a numerical modelling of hydrogen diffusion is performed, concluding that bulk diffusion is not important in hydrogen embrittlement of 316L steel, so that hydrogen transport accelerated by the microdamage itself should be taken into account. (orig.)
Often, lifetime data come from experiments where failure times are grouped. The Weibull distribution is a popular distribution for modeling failure times. Maximum likelihood estimation (MLE) has outstanding large sample properties for the Weibull distribution. This article evaluates small sample properties of MLEs for grouped data. We evaluate sample size requirements for MLE asymptotic properties to take effect. We compare type I and type II censoring for pooled experiments and conclude that bias for the shape parameter estimate can be alarmingly high especially for type II censored data. Finally, we investigate the benefits of the pooled analysis.
Elastic and elasto-plastic modelling of indentation in CFRP cross-ply laminates has been performed. Detailed knowledge of the field solutions in the volume below the indentor forms the basis for the reported micromechanical interpretation of the observed damage in test specimens. The analysis shows that matrix cracks originate at sites of maximum tensile stress perpendicular to fibers. The predicted stress fields due to indentation show that stress concentrations occur in the interface between alternating plies. It is found that microcracking in this zone is a precursor to the observed failure. This analysis is supported by in-situ scanning electron microscopy during loading by a cylindrical indentor onto the laminate supported on a rigid substrate. The microscopy reveals microdamage in the region of interfacial tensile stress concentrations. The onset of indentation failure in these layered composites suggests that plastic interleaves would ...
Since the integrity of the containment penetrations was confirmed under accident management (AM) conditions in the former test, failure criteria tests and aerosol trapping tests were carried out using low-voltage modules and flange gaskets of an actual plant under severe accident (SA) conditions, without AM. The safety margin for failure temperature of the penetrations and the credit for fission product (FP) aerosol trapping effect along the leakage paths of the degraded penetrations were evaluated in the present tests. Failure temperature of the penetrations ranged from 270 to 300degC for low-voltage modules and 300 to 350degC for flange gaskets under 0.4 to 1.0 MPa conditions. Pressure dependency on failure temperature was small. This means that the safety margin of failure temperature under AM condition is more than 70degC. By introducing a equivalent leak area for the damaged ...
With the fire accident in Browns Ferry nuclear power plant as a turning point, the regulation against fire has been strengthened more strictly as seen in the regulatory guide of the United States Nuclear Regulatory Commission. Fire of cables is caused by either the ignition of a cable itself or spread of fire to cables. The aspect of fire is divided into the local ignition and combution and the fire extension and prepagation because of the line-shaped configuration of cables. This report describes the prevention of the spread of fire. As the materials for the prevention of fire spread, fire spread-preventing paint ''Dannekka'', sealant ''Danseal P and L'', and fire prevention tape ''FD tape'' are reported, and the testing method and the results are described in detail. ''Dannekka'' is classified into the solvent dispersion type and the water dispersion type. It may be coated with brush or by spraying. ...
Network security is a discipline that focuses on securing networks from unauthorized access. Given the Escalating threats of malicious cyber attacks, modern enterprises employ multiple lines of defense. A comprehensive defense strategy against such attacks should include (I) an attack detection component that deter- mines the fact that a program is compromised, (2) an attack identification and prevention component that identifies attack packets so that one can block such packets in the future and prevents the attack from further propagation. Over the last decade, a significant amount of research has been vested in the systems that can detect cyber attacks either statically at compile time or dynamically at run time, However, not much effort is spent on automated attack packet identification or attack prevention. In this paper we present a unified solution to the problems mentioned above. We implemented this solution after ...
How do people understand questions about cause and prevent? Some theories propose that people affirm that A causes B if A's occurrence makes a difference to B's occurrence in one way or another. Other theories propose that A causes B if some quantity or symbol gets passed in some way from A to B. The aim of our studies is to compare these theories' ability to explain judgements of causation and prevention. We describe six experiments that compare judgements for causal paths that involve a mechanism, i.e. a continuous process of transmission or exchange from cause to effect, against paths that involve no mechanism yet a change in the cause nevertheless brings about a change in the effect. Our results show that people prefer to attribute cause when a mechanism links cause to effect. In contr...
The IAEA Assessment of Safety Significant Events Team (ASSET) report presents the results of an ASSET team's assessment of their investigation of the effectiveness of the plant for prevention of incidents since 1990 at Zaporozhe nuclear power plant. The results, conclusions and suggestions presented herein reflect the views of the ASSET experts. They are provided for consideration by the responsible authorities in Ukraine. The ASSET team's views presented in this report are based on visits to the plant, on review of documentation made available by the operating organization and on discussions with utility personnel. The report is intended to enhance operational safety at Zaporozhe by proposing improvements to the policy for the prevention of incidents at the plant. The report includes, as a usual practice, the official response of the operating organization as well as of the regulatory body to the ASSET recommendations. Figs.
The 1993 Petroleum Hydrocarbons Conference was comprised of 3 days of technical presentations within the following topic areas: pollution prevention and cost control; development of remediation levels; free-phase and dissolved hydrocarbon contamination management; investigation and analysis of petroleum hydrocarbons; applications of computer modeling for remediation; design and implementation of bioventing; design and implementation of air sparging; soil vapor extraction as a remediation technique; and ground water remediation using natural bacteria. In addition, more than 100 leading companies in the ground water and petroleum industries participated in the Conference Exposition in which a variety of equipment and services for preventing, detecting and remediating ground water contaminated by petroleum hydrocarbons and other organic chemicals was showcased. Individual papers have been processed separately for inclusion in the appropriate data ...
To determine the proportion of rheumatoid arthritis (RA) patients receiving preventive health care according to US Preventive Services Task Force recommendations compared with a community-based population sample, with emphasis on dyslipidemia testing, given the increased risk of cardiovascular disease (CVD) in RA patients. Patients with RA (ICD-9 code 714.0 at ?2 office visits with a rheumatologist) and a primary care physician (PCP) at the Geisinger Health System (GHS) were identified through electronic health records. The records were searched back from 3/31/08 for the length of time required to satisfy each outcome measure. Percentages were compared with population testing rates using the Pearson Chi-square test. Eight hundred and thirty-one RA patients were compared to 169,476 subjects...
Summary This third paper, in a three-part CE series on the preventions of infection in patients with chronic kidney disease, focuses on surveillance and auditing of healthcare-associated infections within the renal care environment. The last decade has seen an increased awareness of the threat to patient safety from healthcare-associated infection (HCAI) and the emergence of multi-drug resistance organisms. Effective HCAI prevention strategies include adequate governance structures, access to expert advice, adherence to standard and transmission-based precautions, minimising the use of invasive medical devices, and surveillance. Surveillance data can be collected using outcome (e.g. infection) and/or process (e.g. hand hygiene compliance audit) measures. Establishing a surveillance program...
Purpose: To prevent structure material meltdown upon rupture of cooling pipeways in a impurity remover by preventing the coolants from flowing into the vacuum vessel while continuing the supply of coolants to other portions to be cooled. Constitution: Dual cooling pipeway systems are disposed to the neutralizing plates of the impurity remover. A rupture detector (pressure gage) is mounted to each of the cooling pipeways and flow rate control valves to be opened and closed by the signal from the detector are disposed to the upstream and downstream of the cooling pipeway. In this constitution if the cooling pipes should be ruptured, the coolant supply is stopped to the ruptured system in which the flow rate valve is closed by the signal from the rupture detector. However, since the coolant is kept to be supplied to the other system of the cooling pipeways, meltdown of the neutralizing plates can be prevented. (Kamimura, M.).
Necrotizing enterocolitis (NEC) is the most common severe gastrointestinal emergency that affects premature newborns. This disease often has a rapid onset with few, if any, antecedent signs that can be used to reliably predict its occurrence. Its rapid onset and progression to death, as well as its severe morbidity when the infant survives, begs for early diagnostic tools that may be used in determining those infants who would be at greatest risk for development of the disease and for whom early preventative measures could be targeted. Although studies have suggested efficacy of several techniques such as breath hydrogen, inflammatory mediators in blood, urine or stool, and genetic markers, these all have drawbacks limiting their use. The application of newly developed "omic" approaches may provide biomarkers for early diagnosis and targeted prevention of this disease. PMID:19190533
BackgroundGreen tea consumption has been shown to have cancer preventive qualities. Among the constituents of green tea, (-)-Epigallocatechin-3-O-gallate (EGCG)...Full Text Available
Osteoporotic vertebral fractures often lead to pain and disability. They can be successfully treated, and possibly prevented, by injecting cement into the vertebral body, a procedure known as vertebroplasty....Full Text Available
Devastating central nervous system injuries and diseases continue to occur in spite of the tremendous efforts of various prevention programs. The enormity of and annual escalation of healthcare...Full Text Available
IntroductionOut-of-school adolescents are often neglected when planning for tobacco prevention programmes whereas they are more vulnerable. Few studies exist in Nigeria about their...Full Text Available
Recent reports confirm that, due to the presence of long-lived, latently infected cell populations, eradication of human immunodeficiency virus type 1 (HIV-1) from infected patients by using antiretroviral...Full Text Available
This book examines the occupational health hazards imposed by neoplasms. Topics considered include: cancer as an occupational hazard; an overview; epidemiological evidence; and interaction of host and lifestyle factors with occupational chemicals in cancer causation.
OBJECTIVESAlthough several studies suggest that slow gait speed is a predictor of falls, it may also be a protective mechanism to prevent falls. Further, fast walking...Full Text Available
Dominant mutations in sarcomere protein genes cause hypertrophic cardiomyopathy, an inherited human disorder with increased ventricular wall thickness, myocyte hypertrophy, and disarray. To understand...Full Text Available
The Good Behavior Game (GBG), a universal classroom behavior management method, was tested in first- and second-grade classrooms in Baltimore beginning in the 1985–1986 school year. Followup...Full Text Available
BackgroundCharacterizing infectious disease burden in Africa is important for prioritizing and targeting limited resources for curative and preventive services and monitoring the...Full Text Available
AbstractBackgroundGender concordance between patients and their physicians is related to prevention screening and other quality indicators. Research suggests female...Full Text Available
When attempting to feed on their hosts, ticks face the problem of host hemostasis (the vertebrate mechanisms that prevent blood loss), inflammation (that can produce itching or pain and thus...Full Text Available
In the absence of a vaccine, there is an urgent need for the development of safe and effective topical microbicides to prevent the sexual transmission of human immunodeficiency virus type 1 (HIV-1)....Full Text Available
BackgroundPublic information about prevention of zoonoses should be based on the perceived problem by the public and should be adapted to regional circumstances. Growing fox populations...Full Text Available
Today, hospitals are involved extensively in social marketing and promotional activities. Recently, investigators from the Centers for Disease Control and Prevention (CDC) estimated that routine testing...Full Text Available
Oysters are permanently exposed to various microbes, and their defense system is continuously solicited to prevent accumulation of invading and pathogenic organisms. Therefore, impairment of the animal's...Full Text Available
Background:Smoking cessation is an important strategy for reducing the harmful effects of tobacco, particularly in the prevention of lung cancer; however, prospective data on the...Full Text Available
Vitamin D deficiency is a well-known comorbidity of obesity that can be exacerbated after bariatric surgery and can predispose the patient for hypocalcemia. Vitamin D and calcium doses to prevent and...Full Text Available
BackgroundSafety for diabetic patients means providing the most suitable treatment for each type of diabetic in order to improve monitoring and to prevent the adverse effects of...Full Text Available
PurposeIn our previous studies we showed that upregulating claudin-6 (CLDN6) expression may contribute to preventing breast cancer, and that 17β-estradiol induces a concentration-...Full Text Available
IntroductionIrradiation of normal, non-malignant bone during cancer therapy can lead to atrophy and increased risk of fracture at several skeletal sites, particularly...Full Text Available
Target of rapamycin (TOR) kinases control cell growth through two functionally distinct multiprotein complexes. TOR complex 1 (TORC1) controls temporal cell growth and is sensitive to rapamycin, whereas...Full Text Available
We investigated the role of early portal hypotensive pharmacotherapy in preventing the development of portal-systemic shunting in a portal hypertensive model of chronic murine schistosomiasis induced...Full Text Available
In the past decade, we have witnessed a revolution in osteoporosis diagnosis and therapeutics. This includes enhanced understanding of basic bone biology, recognizing the severe consequences of fractures...Full Text Available
Phosphoramidite reagents can phosphitylate guanine bases at the O6-position during solid phase synthesis and serious chain cleavage occurs if the base phosphitylation is not eliminated before the iodine/water...Full Text Available
Strong aqueous ammonium hydroxide used to remove N-acyl protecting groups from synthetic oligoribonucleotides causes removal of some alkylsilyl protecting groups from 2'-hydroxyls and leads to chain...Full Text Available
Haemophilia, the commonest hereditary bleeding disorder, arises because of the absence of, decrease in, or deficient functioning of plasma coagulation factor VIII or factor IX. With rare exceptions,...Full Text Available
BACKGROUND: Although the effectiveness of influenza vaccination in high-risk groups has been proven, vaccine coverage continues to be less than 50% in The Netherlands. To improve vaccination rates,...Full Text Available
Physical activity is associated with reduced risk of several age-related diseases as well as with increased longevity in both rodents and humans. Though these associations are well established, evidence...Full Text Available
Chemoprevention, especially through the use of naturally occurring phytochemicals capable of impeding the process of carcinogenesis at one or more steps, is an ideal approach for cancer management....Full Text Available
Metallic O-ring or Helicoflex seals can prevent relaxation and provide greater resilience than composite seals, helping to keep joints leaktight. Their characteristics and applications in the nuclear industry are outlined. (Author).
BackgroundTwo planned trials of pre-exposure prophylaxis tenofovir in Cambodia and Cameroon to prevent HIV infection in high-risk populations were closed due to activist pressure...Full Text Available
Heart disease, cancer, and cerebrovascular disease together cause more than two out of three deaths in the United States annually. These three diseases are largely a result of widespread risk factors...Full Text Available
ER niacin combined with simvastatin provides an additional option for achieving LDL-C and non-HDL-C goals for cardiovascular prevention, with greater efficacy in those with triglyceride levels >200...Full Text Available
ObjectiveThe aim of this study was to evaluate the utility of volume-rendered helical computerized tomography (CT) angiography focusing tracheostomy tube and innominate artery for...Full Text Available
The fundamental tasks of the Oak Ridge Y-12 Plant maintenance operations are planning, scheduling, executing, postmaintenance testing, completing the maintenance job, and supporting these activities with administrative and technical assistance. The Department of Energy (DOE) ``Maintenance Management Program`` guidelines require that we use a graded approach for applying formality and documentation to these maintenance operations. The most-rigorous controls should be placed on maintaining the most-vital systems, structures, and components (SSCs). We must understand risk assessments in order to evaluate which SSCs are most vital. The product of this assessment process is a well-developed understanding of where to apply the most rigor, formality, and documentation. Once we have determined where, we must determine how to apply maintenance so as to mitigate risk. Fundamental to determining how to apply it is an understanding of the main difference between proactive and reactive (or ...
Somatic radiation doses are recognized to be possible factors of carcinogenesis. In correctly performed mammography, however, even as screening test, the radiation dose does not reach such an order of magnitude that the benefit of the procedure as to prevention of breast cancer is called into question.
The paper presents a review of the current state of knowledge on the likely impacts of extreme weather and climate events on coastal zones and small islands in the context of climate change. Possible response options, including prevention, preparedness and adaptation, are indicated.
Hyperglycemia and hyperinsulinemia accelerate both aging and cancer. Antidiabetic biguanides such as metformin decrease glucose, insulin and IGF-1 level. Metformin increases lifespan and prevents cancer...Full Text Available
During the past decade idiopathic venous thromboembolism has become a separate entity, a chronic illness which has required prolonged anticoagulation and other prevention strategies to avoid recurrences....Full Text Available
Enteric infections with attaching/effacing lesion-inducing bacterial pathogens are a worldwide health problem. A murine infection model with one such pathogen, Citrobacter rodentium,...Full Text Available
The tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) has been studied for chronic disease preventive effects, and is marketed as part of many dietary supplements. However, case reports have...Full Text Available
This talk sketches out the main parameters (technology, circuit design) that have an influence on the hardening of digital CMOS integrated circuits. For each technology the more common defects are mentioned. General design rules are proposed to prevent or limit those defects. (D.L.). 2 refs., 2 figs.
The torque-velocity relationship is known to be affected by ageing, decreasing its protective role in the prevention of falls. Interindividual variability in this torque-velocity relationship is partly...Full Text Available
Despite the recent success of genome-wide association studies (GWASs) in identifying loci consistently associated with coronary artery disease (CAD), a large proportion of the genetic components of...Full Text Available
The cancer preventive action of (−)-epigallocatechin gallate (EGCG), found in green tea, is strongly supported by epidemiology and laboratory research data. However, the mechanism by...Full Text Available
Plant surfaces covered with crystalline epicuticular waxes are known to be anti-adhesive, hardly wettable and preventing insect attachment. But there are insects that are capable of gluing their eggs...Full Text Available
Chemoprevention strategies to prevent the development of lung cancer in at-risk individuals are a key component in disease management. In addition to being highly effective, an ideal chemopreventive...Full Text Available
Prophylactic knee braces are designed to prevent and reduce the severity of ligamentous injuries to the knee. Conflicting evidence is reported concerning their efficacy. The purpose of this study was...Full Text Available
BackgroundThis paper is based on data gathered from a 2006 survey of 1,098 "street children" in Northern Tanzania. It examines the role that school may play in preventing the migration...Full Text Available
BackgroundEffective prevention of excessive alcohol use has the potential to reduce the public burden of disease considerably. We investigated the cost-effectiveness of Screening...Full Text Available
This guidebook organizes the profusion of rules and regulations surrounding radiation protection into a single-volume reference. Employee and public protection, accident prevention, and emergency preparedness are included in this comprehensive coverage. Whenever possible, information is presented in convenient checklists, tables, or outlines that enable you to locate information quickly.
Nitric oxide (NO)-based therapies effectively inhibit neointimal hyperplasia in animal models of arterial injury and bypass grafting, but are not available clinically. We created a simple, effective,...Full Text Available
Public health activities, especially infectious disease control, depend on effective teamwork. We present the results of a pilot audit questionnaire aimed at assessing the quality of public health services...Full Text Available
There is increasing evidence of a biochemical link between lipid oxidation and bone metabolism. Paraoxonase 1 (PON1) prevents the oxidation of low-density lipoprotein (LDL) and metabolizes biologically...Full Text Available
Numerous epidemiological studies have consistently demonstrated that individuals who eat more fruits and vegetables (which are rich in carotenoids) and who have higher serum β-carotene levels...Full Text Available
Background: The objective of this study was to assess the factors associated with the traffic mortality in the region of Central Macedonia in order to produce evidence in building up preventive...Full Text Available
BackgroundTuberculosis (TB) is the most common opportunistic infection in HIV-infected adults in developing countries. Isoniazid (INH) is recommended for treatment of latent TB infection,...Full Text Available
BackgroundChronic kidney disease and end-stage renal disease are major causes of morbidity and mortality that are seen far more commonly in the aged population. Interestingly, kidney...Full Text Available
Adjuvant therapy aims to prevent outgrowth of residual disease but can induce serious side effects. Weighing conflicting treatment effects and communicating this information with patients is not elementary....Full Text Available
BackgroundDuring surgery, controlled haemostasis to prevent blood loss is vital for a successful outcome. It can be difficult to ligate vessels located deep in the abdomen. A device...Full Text Available
Assessment of the regulation of plant metabolism by the calcium ion requires a knowledge of its intracellular levels and dynamics. Technical problems have prevented direct measurement of the concentration...Full Text Available