Observation of Electroweak Single Top-Quark Production with the CDF II Experiment

Energy Technology Data Exchange (ETDEWEB)

Lueck, Jan [Karlsruhe Inst. of Technology (Germany)

2009-07-24

The standard model of elementary particle physics (SM) predicts, besides the top-quark pair production via the strong interaction, also the electroweak production of single top-quarks [19]. Up to now, the Fermilab Tevatron proton-antiproton-collider is the only place to produce and study top quarks emerging from hadron-hadron-collisions. Top quarks were directly observed in 1995 during the Tevatron Run I at a center-of-mass energy of √s = 1.8 TeV simultaneously by the CDF and D0 Collaborations via the strong production of top-quark pairs. Run II of the Tevatron data taking period started 2001 at √s = 1.96 TeV after a five year upgrade of the Tevatron accelerator complex and of both experiments. One main component of its physics program is the determination of the properties of the top quark including its electroweak production. Even though Run II is still ongoing, the study of the top quark is already a successful endeavor, confirmed by dozens of publications from both Tevatron experiments. A comprehensive review of top-quark physics can be found in reference. The reasons for searching for single top-quark production are compelling. As the electroweak top-quark production proceeds via a Wtb vertex, it provides the unique opportunity of the direct measurement of the CKM matrix element |V_tb|, which is expected to be |V_tb| ~ 1 in the SM. Significant deviations from unity could be an indication of a fourth quark generation, a production mode via flavor-changing neutral currents, and other new phenomena, respectively. There are two dominating electroweak top-quark production modes at the Fermilab Tevatron: the t-channel exchange of a virtual W boson striking a b quark and the s-channel production of a timelike W boson via the fusion of two quarks. In proton-antiproton-collisions the third electroweak production mode, the associated Wt production of an on-shell W boson in conjunction with a top quark has a comparatively negligible small

The search of the top quark in the UA2' experiment

International Nuclear Information System (INIS)

Buskulic, D.

1989-05-01

We present in this thesis a preliminary analysis of the data accumulated in 1988 by the UA2' experiment at the SpantipS collider at CERN, at the centre-of-mass energy of 630 GeV. The integrated luminosity for this study is 2.5 pb -1 . It's aim is to search for a top quark, in the decay channel top giving b+electron+neutrino, producing a high transverse momentum electron and neutrino accompanied by two (proton-antiproton -- W -- top-antibottom pair) to four (proton-antiproton -- top-antitop pair) jets. Two studies have been performed: one with the accent on the good measurement of missing transverse momentum in UA2', requiring it to be above 15 GeV/c, is sensitive to top quark masses between 40 and 65 GeV/c 2 ; the other, with the accent rather on the excellent electron identification power of UA2', is sensitive to top quark masses between 30 and 50 GeV/c 2 . A detailed study of the various background processes (W+2jets, bottom-antibottom, QCD background) is also presented, followed by a preliminary discussion of the systematic errors on the various predictions. No signal was observed for top quark masses between 30 and 60 GeV/c 2 [fr

Sodium Loop Safety Facility W-2 experiment fuel pin rupture detection system. [LMFBR

Energy Technology Data Exchange (ETDEWEB)

Hoffman, M.A.; Kirchner, T.L.; Meyers, S.C.

1980-05-01

The objective of the Sodium Loop Safety Facility (SLSF) W-2 experiment is to characterize the combined effects of a preconditioned full-length fuel column and slow transient overpower (TOP) conditions on breeder reactor (BR) fuel pin cladding failures. The W-2 experiment will meet this objective by providing data in two technological areas: (1) time and location of cladding failure, and (2) early post-failure test fuel behavior. The test involves a seven pin, prototypic full-length fast test reactor (FTR) fuel pin bundle which will be subjected to a simulated unprotected 5 cents/s reactivity transient overpower event. The outer six pins will provide the necessary prototypic thermal-hydraulic environment for the center pin.

Top-tier requirements for KNGR

International Nuclear Information System (INIS)

Sung-Jae, Ch.; Kwangho, L.; Dong Wook, J.

1996-01-01

In 1992, Korea Electric Power Corporation (KEPCO) has launched the next generation reactor project to develop the standard design of an advanced pressurized water reactor by 2000. This advanced reactor aims to have the sufficient capability to be a safe, environmentally sound and economical energy source for 2000's in Korea. In conjunction with the project development, the program phase I is studied and it is in the Korean Next Generation Reactor (KNGR) first phase project that the requirements of this specification called ''Top-tier'' have been established. These functional requirements are of the first importance for the design, construction and operation of a nuclear power plant. These requirements are divided into safety requirements, serious accidents control, design base requirements, definition of the system characteristics, performance, construction feasibility, economical objectives, site parameters and design processes. The ''Top-tier'' requirements are concentrated on the improvement of the safety and reliability. Safety is one of the first priorities. In particular, the requirements for the design of the next reactors generation must include the capacity to control serious accidents because when an accident occurs, the protection degree is crucial. The KNGR requirements include the existing nuclear power plants competitiveness as well as those of the coal thermal plants. Moreover, when safety is reinforced, the economic competitiveness can be assured. At the present time, a subsequent specification for the KNGR considering the bases of the domestic technology and experimenting the running. (O.M.)

Over the top: Experiment and the testing of hypotheses in the search for the top quark

Science.gov (United States)

Staley, Kent Wade

1998-07-01

This study presents a historical account of experiments, performed by the Collider Detector at Fermilab (CDF) collaboration, which led to the discovery of the top quark, and a discussion of philosophical issues raised by that episode. The historical discussion is based on published and unpublished documents and oral history interviews, and is presented in two parts: First, the formation of the collaboration and construction of the detector are described. The activities of the collaborators during the period of detector construction are described in terms of the development of resources for a general experimental programme. Second, the development of the means of analyzing the data for the top quark search is described, particularly aspects of the analysis that were disputed. The hypothesis that collaboration researchers have come to regard the social process of resolving disputes as a matter of methodological importance is suggested. The philosophical discussion of the experiment employs the hierarchy of models approach of Patrick Suppes and Deborah Mayo in order to examine the logic of hypothesis testing and draw some conclusions regarding the nature of scientific evidence. In an extension of an argument presented by Peter Achinstein, the account of hypothesis testing given by hypothetico-deductivist philosophers such as Karl Popper and R. B. Braithwaite is examined in light of the reasoning employed in the top search, and is found wanting. The prediction based on the hypothesis being tested in the top search is found to have been inferred inductively from the experimental data. Finally, a discussion is presented of tuning on the signal, a form of bias in the testing of hypotheses. The proscription of this form of bias resembles John Worrall's requirement of use novelty, but is shown instead to serve the aim of devising a test of the hypothesis that is severe, in the sense articulated by Deborah Mayo. It is shown that the evaluation of evidence claims, as it

Regulatory experience of TOPS: an internet-based system to prevent healthy subjects from over-volunteering for UK clinical trials.

Science.gov (United States)

Allen, C; Francis, G; Martin, J; Boyce, M

2017-12-01

The aim was to review the use of The Over-volunteering Prevention System (TOPS) since the HRA began hosting it in 2013, and the Medicines and Healthcare products Regulatory Agency (MHRA) experience of monitoring its use by UK clinical research units. The HRA searched the TOPS database for the number, type and location of units and the number of entries. The MHRA inspectors reviewed their findings from routine inspections. Twenty-two additional UK units registered to use TOPS during 2013-2016, making a total of 84 units since TOPS was established in 2002. Use of TOPS is now a condition of research ethics committee approval of a phase 1 study and fulfils MHRA accreditation requirements for preventing over-volunteering. The total number of entries by all active units during 2013-2016 was 89,335, of which 84% were UK citizens and 16% non-UK citizens. The total number of entries during 2002-2016 was 249,612. Only 15 of 24,531 subjects (1/1600) and 18 of 18,745 subjects (1/1040) entered in 2015 and 2016, respectively, were deemed potential over-volunteers. The findings continue to support the concept that TOPS not only helps to prevent over-volunteering, but also deters subjects from trying to do so. Regulation of TOPS by the HRA and MHRA has enhanced its effectiveness, benefited all users and helped to improve the safety of volunteers who participate in non-therapeutic trials in the UK. The UK is still the only country with a national database to prevent over-volunteering that has published data on its widespread use and effectiveness.

TOP counter for particle identification at the Belle II experiment

Energy Technology Data Exchange (ETDEWEB)

Inami, Kenji

2014-12-01

Ring imaging Cherenkov counter, named TOP counter, utilizing precise photon detection timing has been developed as a particle identification detector for the Belle II experiment. The real size prototype has been produced and tested with 2 GeV positrons at Spring-8 LEPS beam line. The quartz radiator production and assembling with microchannel plate photomultipliers was successfully carried out. The beam test data shows good agreement with full Monte-Carlo simulation results in the ring image and the distribution of number of detected photons and timing information. - Highlights: • TOP counter was developed as a particle identification detector for the Belle II experiment. • The real size prototype was produced and tested with 2 GeV positrons. • The quartz radiator production and assembling with MCP-PMT was successfully carried out. • The beam test data shows good agreement with full Monte-Carlo simulation results.

Radiation safety culture in the UK medical sector: a top to bottom strategy

International Nuclear Information System (INIS)

Chapple, Claire-Louise; Bradley, Andy; Murray, Maria; Orr, Phil; Reay, Jill; Riley, Peter; Rogers, Andy; Sandhu, Navneet; Thurston, Jim

2017-01-01

UK professional bodies have established a number of sectorial working parties to provide guidance on the improvement of radiation safety (RS) culture in the workplace. The medical sector provides unique challenges in this regard, and the remit of the medical group was to review the current state of RS culture and to develop a framework for improvement. The review of current RS culture was based on measurable indicators, including data from regulatory inspections, personal monitoring data and incident data. An online survey to capture the RS-related views and experience of hospital staff at all levels was carried out, and the responses provided a wealth of information on RS awareness and implementation across the country. The framework for improving RS culture includes both 'top-down' initiatives to engage management and regulators, and 'bottom-up' initiatives relating to engagement and training of different staff groups. A 'Ten-point Assessment' on what constitutes a good approach to medical RS culture has been proposed, which provides a tool for management to assess RS culture in the workplace and has potential use in regulatory inspections in the UK. (authors)

A qualitative study of Southern U.S. consumers' top of the mind beliefs about the safety of local beef.

Science.gov (United States)

Telligman, Amy L; Worosz, Michelle R; Bratcher, Christy L

2017-02-01

Following the Reasoned Action Approach, the aim of this study was to explore consumers' top-of-mind food safety beliefs about local beef. Beef consumers recruited from farmers' markets (N = 101) and grocery stores (N = 174) across the state of Alabama participated in face-to-face intercept surveys. The survey included closed- and open-ended questions designed to elicit consumers' food safety beliefs about local beef. Results indicate that beef safety was not a top-of-mind concern for a majority of participants, however of the total number of participants familiar with the term "local beef" (n = 168, 61%), a majority (n = 105, 63%) associated local beef with improved food safety. Content analysis of verbatim text revealed that consumers believed local beef was safer because they possess greater knowledge about the product and less shipping was involved. Respondents also believe that locally processed meat is derived from small-scale operations which provided the assurance that local beef is more likely to meet U.S. regulatory standards and therefore be safer. Consumers believe they have more oversight of local beef due to both their relationships with supply chain actors and proximity which also provided food safety assurances. Copyright © 2016 Elsevier Ltd. All rights reserved.

Study of top and anti-top mass difference

CERN Document Server

Leedumrongwatthanakun, Saroch

2013-01-01

The invariance of the standard model under CPT transformations leads to the equality of particle and antiparticle masses. The recent measurements performed by the CMS experiment on the top anti-top mass difference are a test of such symmetry. In this work non-perturbative QCD effects, which may eventually lead to an apparent difference in the mass of a top and anti-top quark, are studied.

Radiological safety design considerations for fusion research experiments

International Nuclear Information System (INIS)

Crase, K.W.; Singh, M.S.

1979-01-01

A wide variety of fusion research experiments are in the planning or construction stages. Two such experiments, the Nova Laser Fusion Facility and the Mirror Fusion Test Facility (MFTF), are currently under construction at Lawrence Livermore Laboratory. Although the plasma chamber vault for MFTF and the Nova target room will have thick concrete walls and roofs, the radiation safety problems are made complex by the numerous requirements for shield wall penetrations. This paper addresses radiation safety considerations for the MFTF and Nova experiments, and the need for integrated safety considerations and safety technology development during the planning stages of fusion experiments

Mentoring Top Leadership Promotes Organizational Innovativeness through Psychological Safety and Is Moderated by Cognitive Adaptability.

Science.gov (United States)

Moore, James H; Wang, Zhongming

2017-01-01

Mentoring continues to build momentum among startups and established enterprises due to its positive impact on individuals and organizations. Unlike previous studies, this research focuses on mentoring higher level leadership, such as the CEO, and demonstrates its unique relationship to organizational innovativeness. Our sample included 200 mentored executives and entrepreneurs who personally identify and exploit opportunities. Our findings confirm that mentoring top leaders positively relates to their perceived innovativeness of the organization and that the relationship is mediated by these leaders' perception of psychological safety within the organization. Our findings also confirm that the relationship is negatively moderated by these leaders' cognitive adaptability. The reliability and validity of the results have been proved by using confirmatory factor analysis and advanced regression analytics. As a result, this work demonstrates the value of mentoring top leadership and advocates the importance of establishing a psychologically safe environment to inspire not only top leadership to try new avenues but also for all those within the organization to speak up and speak out. Additionally, our findings encourage organizations to proactively and selectively prioritize mentoring among top leadership, taking into account their differing levels of cognitive adaptability. Finally, further research could focus on how to provide greater support for mentors of higher level leaders.

Measurement of cross section of quark pair production top with the D0 experiment at the Tevatron and determination the top quark mass using this measure

Energy Technology Data Exchange (ETDEWEB)

Chevalier-Thery, Solene [Univ. Pierre et Marie Curie, Paris (France)

2010-06-01

The top quark has been discovered by CDF and D0 experiments in 1995 at the proton-antiproton collider Tevatron. The amount of data recorded by both experiments makes it possible to accurately study the properties of this quark: its mass is now known to better than 1% accuracy. This thesis describes the measurement of the top pair cross section in the electron muon channel with 4, 3 fb ^-1 recorded data between 2006 and 2009 by the D0 experiment. Since the final state included a muon, improvements of some aspects of its identification have been performed : a study of the contamination of the cosmic muons and a study of the quality of the muon tracks. The cross section measurement is in good agreement with the theoretical calculations and the other experimental measurements. This measurement has been used to extract a value for the top quark mass. This method allows for the extraction of a better defined top mass than direct measurements as it depends less on Monte Carlo simulations. The uncertainty on this extracted mass, dominated by the experimental one, is however larger than for direct measurements. In order to decrease this uncertainty, the ratio of the Z boson and the top pair production cross sections has been studied to look for some possible theoretical correlations. At the Tevatron, the two cross sections are not theoretically correlated: no decrease of the uncertainty on the extracted top mass is therefore possible.

Measurement of cross section of quark pair production top with the D0 experiment at the Tevatron and determination the top quark mass using this measure

International Nuclear Information System (INIS)

Chevalier-Thery, Solene

2010-01-01

The top quark has been discovered by CDF and D0 experiments in 1995 at the proton-antiproton collider Tevatron. The amount of data recorded by both experiments makes it possible to accurately study the properties of this quark: its mass is now known to better than 1% accuracy. This thesis describes the measurement of the top pair cross section in the electron muon channel with 4, 3 fb -1 recorded data between 2006 and 2009 by the D0 experiment. Since the final state included a muon, improvements of some aspects of its identification have been performed : a study of the contamination of the cosmic muons and a study of the quality of the muon tracks. The cross section measurement is in good agreement with the theoretical calculations and the other experimental measurements. This measurement has been used to extract a value for the top quark mass. This method allows for the extraction of a better defined top mass than direct measurements as it depends less on Monte Carlo simulations. The uncertainty on this extracted mass, dominated by the experimental one, is however larger than for direct measurements. In order to decrease this uncertainty, the ratio of the Z boson and the top pair production cross sections has been studied to look for some possible theoretical correlations. At the Tevatron, the two cross sections are not theoretically correlated: no decrease of the uncertainty on the extracted top mass is therefore possible.

Safety review of experiments at Albuquerque Operations Office

International Nuclear Information System (INIS)

Elliott, K.

1984-01-01

The Department of Energy (DOE) Albuquerque Operations Office is responsible for the safety overview of nuclear reactor and critical assembly facilities at Sandia National Laboratories, Los Alamos National Laboratory, and the Rocky Flats Plant. The important safety concerns with these facilities involve the complex experiments that are performed, and that is the area emphasized. A determination is made by the Albuquerque Office (AL) with assistance from DOE/OMA whether or not a proposed experiment is an unreviewed safety question. Meetings are held with the contractor to resolve and clarify questions that are generated during the review of the proposed experiment. The AL safety evaluation report is completed and any recommendations are discussed. Prior to the experiment a preoperational appraisal is performed to assure that personnel, procedures, and equipment are in readiness for operations. During the experiment, any abnormal condition is reviewed in detail to determine any safety concerns

Safety Assurance for Irradiating Experiments in the Advanced Test Reactor

Energy Technology Data Exchange (ETDEWEB)

T. A. Tomberlin; S. B. Grover

2004-11-01

The Advanced Test Reactor (ATR), located at the Idaho National Engineering and Environmental Laboratory (INEEL), was specifically designed to provide a high neutron flux test environment for conducting a variety of experiments. This paper addresses the safety assurance process for two general types of experiments conducted in the ATR facility and how the safety analyses for experiments are related to the ATR safety basis. One type of experiment is more routine and generally represents greater risks; therefore, this type of experiment is addressed in more detail in the ATR safety basis. This allows the individual safety analysis for this type of experiment to be more standardized. The second type of experiment is defined in more general terms in the ATR safety basis and is permitted under more general controls. Therefore, the individual safety analysis for the second type of experiment tends to be more unique and is tailored to each experiment.

Safety Assurance for Irradiating Experiments in the Advanced Test Reactor

International Nuclear Information System (INIS)

T. A. Tomberlin; S. B. Grover

2004-01-01

The Advanced Test Reactor (ATR), located at the Idaho National Engineering and Environmental Laboratory (INEEL), was specifically designed to provide a high neutron flux test environment for conducting a variety of experiments. This paper addresses the safety assurance process for two general types of experiments conducted in the ATR facility and how the safety analyses for experiments are related to the ATR safety basis. One type of experiment is more routine and generally represents greater risks; therefore, this type of experiment is addressed in more detail in the ATR safety basis. This allows the individual safety analysis for this type of experiment to be more standardized. The second type of experiment is defined in more general terms in the ATR safety basis and is permitted under more general controls. Therefore, the individual safety analysis for the second type of experiment tends to be more unique and is tailored to each experiment

Radiation Safety Culture in the UK Medical Sector: A Top to Bottom Strategy.

Science.gov (United States)

Chapple, Claire-Louise; Bradley, Andy; Murray, Maria; Orr, Phil; Reay, Jill; Riley, Peter; Rogers, Andy; Sandhu, Navneet; Thurston, Jim

2017-04-01

UK professional bodies have established a number of sectorial working parties to provide guidance on the improvement of radiation safety (RS) culture in the workplace. The medical sector provides unique challenges in this regard, and the remit of the medical group was to review the current state of RS culture and to develop a framework for improvement. The review of current RS culture was based on measurable indicators, including data from regulatory inspections, personal monitoring data and incident data. An online survey to capture the RS-related views and experience of hospital staff at all levels was carried out, and the responses provided a wealth of information on RS awareness and implementation across the country. The framework for improving RS culture includes both 'top-down' initiatives to engage management and regulators, and 'bottom-up' initiatives relating to engagement and training of different staff groups. A 'Ten-point Assessment' on what constitutes a good approach to medical RS culture has been proposed, which provides a tool for management to assess RS culture in the workplace and has potential use in regulatory inspections in the UK. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The spent fuel safety experiment

International Nuclear Information System (INIS)

Harmms, G.A.; Davis, F.J.; Ford, J.T.

1995-01-01

The Department of Energy is conducting an ongoing investigation of the consequences of taking fuel burnup into account in the design of spent fuel transportation packages. A series of experiments, collectively called the Spent Fuel Safety Experiment (SFSX), has been devised to provide integral benchmarks for testing computer-generated predictions of spent fuel behavior. A set of experiments is planned in which sections of unirradiated fuel rods are interchanged with similar sections of spent PWR fuel rods in a critical assembly. By determining the critical size of the arrays, one can obtain benchmark data for comparison with criticality safety calculations. The integral reactivity worth of the spent fuel can be assessed by comparing the measured delayed critical fuel loading with and without spent fuel. An analytical effort to model the experiments and anticipate the core loadings required to yield the delayed critical conditions runs in parallel with the experimental effort

US nuclear safety. Review and experience

International Nuclear Information System (INIS)

Hanauer, S.H.

1977-01-01

The paper deals with the evolution of reactor safety principles, design bases, regulatory requirements, and experience in the United States. Safety concerns have evolved over the years, from reactivity transients and shut-down systems, to blowdowns and containment, to severe design basis accidents and mitigating systems, to the performance of actual materials, systems and humans. The primary safety concerns of one epoch have been superseded in considerable measure by those of later times. Successive plateaus of technical understanding are achieved by solutions being found to earlier problems. Design studies, research, operating experience and regulatory imperatives all contribute to the increased understanding and thus to the safety improvements adopted and accepted. The improvement of safety with time, and the ability of existing reactors to operate safely in the face of new concerns, has confirmed the correctness and usefulness of the defence-in-depth approach and safety margins used in safety design in the United States of America. A regulatory programme such as the one in the United States justifies its great cost by its important contributions to safety. Yet only the designers, constructors and operators of nuclear power plants can actually achieve public safety. The regulatory programme audits, assesses and spot-checks the actual work. Since neither materials nor human beings are flawless, mistakes will be made; that is why defence-in-depth and safety margins are provided. The regulatory programme should enhance safety by decreasing the frequency of uncorrected mistakes. Maintenance of public safety also requires technical and managerial competence and attention in the organizations responsible for nuclear plants as well as regulatory organizations. (author)

[Operating Room Nurses' Experiences of Securing for Patient Safety].

Science.gov (United States)

Park, Kwang Ok; Kim, Jong Kyung; Kim, Myoung Sook

2015-10-01

This study was done to evaluate the experience of securing patient safety in hospital operating rooms. Experiential data were collected from 15 operating room nurses through in-depth interviews. The main question was "Could you describe your experience with patient safety in the operating room?". Qualitative data from the field and transcribed notes were analyzed using Strauss and Corbin's grounded theory methodology. The core category of experience with patient safety in the operating room was 'trying to maintain principles of patient safety during high-risk surgical procedures'. The participants used two interactional strategies: 'attempt continuous improvement', 'immersion in operation with sharing issues of patient safety'. The results indicate that the important factors for ensuring the safety of patients in the operating room are manpower, education, and a system for patient safety. Successful and safe surgery requires communication, teamwork and recognition of the importance of patient safety by the surgical team.

Top Quark Physics with CMS

CERN Multimedia

CERN. Geneva

2011-01-01

Higgs mechanism. There are various hints at deviations from the Standard Model expectation which have been observed recently by Tevatron experiments in top final states. Several signatures of new physics accessible at the LHC either suffer from top-quark production as a significant background or contain top quarks themselves. In this talk, we present results on top quark physics obtained from the first LHC data collected by the CMS experiment.They include measurements of the top pair production cross section in various channels and their combination, measurements of the top quark mass, the single top cross section, a search for new particles decaying into top pairs, and a first look at the charge asymmetry.

Individual employee's perceptions of " Group-level Safety Climate" (supervisor referenced) versus " Organization-level Safety Climate" (top management referenced): Associations with safety outcomes for lone workers.

Science.gov (United States)

Huang, Yueng-Hsiang; Lee, Jin; McFadden, Anna C; Rineer, Jennifer; Robertson, Michelle M

2017-01-01

Research has shown that safety climate is among the strongest predictors of safety behavior and safety outcomes in a variety of settings. Previous studies have established that safety climate is a multi-faceted construct referencing multiple levels of management within a company, most generally: the organization level (employee perceptions of top management's commitment to and prioritization of safety) and group level (employee perceptions of direct supervisor's commitment to and prioritization of safety). Yet, no research to date has examined the potential interaction between employees' organization-level safety climate (OSC) and group-level safety climate (GSC) perceptions. Furthermore, prior research has mainly focused on traditional work environments in which supervisors and workers interact in the same location throughout the day. Little research has been done to examine safety climate with regard to lone workers. The present study aims to address these gaps by examining the relationships between truck drivers' (as an example of lone workers) perceptions of OSC and GSC, both potential linear and non-linear relationships, and how these predict important safety outcomes. Participants were 8095 truck drivers from eight trucking companies in the United States with an average response rate of 44.8%. Results showed that employees' OSC and GSC perceptions are highly correlated (r= 0.78), but notable gaps between the two were observed for some truck drivers. Uniquely, both OSC and GSC scores were found to have curvilinear relationships with safe driving behavior, and both scores were equally predictive of safe driving behavior. Results also showed the two levels of climate significantly interacted with one another to predict safety behavior such that if either the OSC or GSC scores were low, the other's contribution to safety behavior became stronger. These findings suggest that OSC and GSC may function in a compensatory manner and promote safe driving behavior even

Search for electroweak production of the top quark in the D diameter experiment; Recherche de la production electrofaible de quark top dans l'experience D diametre

Energy Technology Data Exchange (ETDEWEB)

Agelou, M

2005-05-01

This thesis deals with the search for a signal of the electroweak production of the top quark. This signal is made up of a high energy muon issued from the decay of a W, itself produced by a top quark. As the neutrino escapes from the detection system, some transverse energy is expected to be missing and at least 2 jets must be released with at least one jet of B. In the first chapter the author presents the standard model and reviews what physics can be made with an accelerator like the Tevatron. The second chapter presents the quest for the top quark and its discovery at the Tevatron in 1995. The third chapter is dedicated to the phenomenology of the electroweak production of the top. The chapter four presents the Tevatron and the different detectors involved in the D0 experiment. The chapter five is dedicated to the tools necessary to perform data analysis, it means to assess the corrections to apply to muon momentum, to simulated background events and to algorithms of B jet identification. The last chapter is dedicated to the search analysis of the top electroweak production in the muonic channel. 2 analysis are described: one using 158 pb{sup -1} of data and that is based on the presence of one muon in a jet to identify a B jet and the other one operating on 230 pb{sup -1} of data and that is based on a more efficient algorithm of B jet identification. This work allows us to propose a maximum value of 22.8 pb for the electroweak production cross-section of the top quark when s and t channels are combined. (A.C.)

Industry use of operating experience to achieve improved nuclear plant safety

International Nuclear Information System (INIS)

Zebroski, E.L.

1981-01-01

A principal lesson drawn from the accident at Three Mile Island was the need for a comprehensive and rigorous system for analysis and feedback of operating experience to reactor operators. Chief executives of US utilities directed in mid-1979 that an intensive and rigorous system of analysis and feedback of operating experience be established. This system is commonly referred to as the ''Significant Events Program''. Since April 1980, the Nuclear Safety Analysis Center (NSAC) has been joined by the Institute for Nuclear Power Operations (INPO) in the field investigation of significant operating events. NSAC has responsibility for analysis of the design and physical events aspects, while INPO has primary responsibility for the operators' aspects, including procedures and training. The process of screening, analysis and feedback of operating experience is now functioning as a seven-step process. A variety of data sources is used, including License Event Reports and outage and major maintenance reports. These are compiled and indexed in convenient form. However, such data bases are used only as incidental tools for the basic investigations and analytical efforts. Rapid dissemination of results is provided by a computer-aided conferencing system, which links 70 operating LWR reactors in the USA, and which has now been extended to four utilities outside the USA, representing several dozen more reactors. Major safety and economic incentives are evident for the rigorous use of such operating experience and for participation in a comprehensive system. Traditional habits of secrecy are recognized as obstacles to timely communication. A principal responsibility of top management of reactor-operating organizations is to overcome such habits where they are counter to the public interest, as well as to the health and survival interest of the utility itself

Labor unions and safety climate: perceived union safety values and retail employee safety outcomes.

Science.gov (United States)

Sinclair, Robert R; Martin, James E; Sears, Lindsay E

2010-09-01

Although trade unions have long been recognized as a critical advocate for employee safety and health, safety climate research has not paid much attention to the role unions play in workplace safety. We proposed a multiple constituency model of workplace safety which focused on three central safety stakeholders: top management, ones' immediate supervisor, and the labor union. Safety climate research focuses on management and supervisors as key stakeholders, but has not considered whether employee perceptions about the priority their union places on safety contributes contribute to safety outcomes. We addressed this gap in the literature by investigating unionized retail employee (N=535) perceptions about the extent to which their top management, immediate supervisors, and union valued safety. Confirmatory factor analyses demonstrated that perceived union safety values could be distinguished from measures of safety training, workplace hazards, top management safety values, and supervisor values. Structural equation analyses indicated that union safety values influenced safety outcomes through its association with higher safety motivation, showing a similar effect as that of supervisor safety values. These findings highlight the need for further attention to union-focused measures related to workplace safety as well as further study of retail employees in general. We discuss the practical implications of our findings and identify several directions for future safety research. 2009 Elsevier Ltd. All rights reserved.

Search for the decay of a top quark superpartner into a top quark and a neutralino using multivariate techniques at the ATLAS experiment

CERN Document Server

Börner, Daniela; Pataraia, Sophio

This master thesis describes a search for Supersymmetry at the ATLAS experiment at the LHC. For this search it is necessary to know the differences between the analysed decay of the top quark superpartner (stop quark) into a top quark and a neutralino and the corresponding backgrounds. Therefore distributions with different behaviours for these decays are needed. Separating variables are for example the missing transverse energy, the transverse mass, the perpendicular component of the missing transverse energy to the leptonically decaying top quark and some angular distributions between the decay products of the top quarks, the missing transverse energy, or the leading jets. Some of these variables are also used in the official ATLAS search. These variables are used in a neural network which is trained to differentiate between the stop decay and the two main backgrounds – $t\\bar{t}$ and W+jets. This new method was optimised in order to reach a better signal to background ratio than the simple cut analysis. ...

Maximizing prosthetic valve size with the Top Hat supra-annular aortic valve

DEFF Research Database (Denmark)

Aagaard, Jan; Geha, Alexander S.

2007-01-01

BACKGROUND AND AIM OF THE STUDY: The CarboMedics Top Hat supra-annular aortic valve allows a one-size (and often two-size) increase over the standard intra-annular valve. This advantage should minimize the risk of patient-prosthesis mismatch, where the effective prosthetic valve orifice area....... This study evaluates the authors' clinical experience with Top Hat supra-annular aortic valve size selection, and the technical aspects of implantation. METHODS: Between January 1999 and October 2005, a total of 251 consecutive patients underwent 252 aortic valve replacements with Top Hat supra...... required unplanned coronary bypass, and 30-day mortality was 2.0% (5/251), indicating a good safety profile for the valves implanted in this series. CONCLUSION: The general distribution of implant sizes in the US indicates that cardiac surgeons may be under-sizing the Top Hat supra-annular aortic valve...

Measurement of top quark pair production cross section and charge asymmetry at the LHC with the ATLAS experiment.

CERN Document Server

Besana, Maria Ilaria

In March 2010 the Large Hadron Collider (LHC) at CERN started its operation at a center of mass energy of 7 TeV. During this period, the ATLAS experiment has been collecting a large number of proton-proton collision events, resulting in an integrated luminosity of about 5.2 fb^(-1) up to now. My PhD research has been focused on top quark physics, which is one of the milestones of the ATLAS experiment physics program. The production of top quarks is indeed the dominant high p_T process in p-p collisions at multi-TeV energies, after QCD jets, W and Z bosons. Furthermore, top physics is a rich subject, in fact top quark events are used for detector commissioning and to provide a consistency test of the Standard Model (SM). Finally the top quark sector is considered a good channel for new physics discovery. In some Beyond Standard Model (BSM) theories top quark pairs can be produced by the exchange of undiscovered heavy particles. The first part of my PhD activity has been dedicated to the top quark pair producti...

Low-cost electron-gun pulser for table-top maser experiments

Science.gov (United States)

Grinberg, V.; Jerby, E.; Shahadi, A.

1995-04-01

A simple 10 kV electron-gun pulser for small-scale maser experiments is presented. This low-cost pulser has operated successfully in various table-top cyclotron-resonance maser (CRM) and free-electron maser (FEM) experiments. It consists of a low-voltage capacitor bank, an SCR control circuit and a transformer bank (car ignition coils) connected directly to the e-gun. The pulser produces a current of 3 A at 10 kV voltage in a Gaussian like shape of 1 ms pulse width. The voltage sweep during the pulse provides a useful tool to locate resonances of CRM and FEM interactions. Analytical expressions for the pulser design and experimental measurements are presented.

US nuclear safety review and experience

International Nuclear Information System (INIS)

Gilinsky, V.

1977-01-01

The nuclear safety review of commercial nuclear power reactors has changed over the years from the relatively simple review of Dresden 1 in 1955 to the highly complex and sophisticated regulatory process which characterizes today's reviews. Four factors have influenced this evolution: (1) maturing of the technology and industry; (2) development of the regulatory process and associated staff; (3) feedback of operating experience; and (4) public awareness and participation. The NRC's safety review responsibilities start before an application is tendered and end when the plant is decommissioned. The safety review for reactor licensing is a comprehensive, two-phase process designed to assure that all the established conservative acceptance criteria are satisfied. Operational safety is assured through a strong inspection and enforcement program which includes shutting down operating facilities when necessary to protect the health and safety of the public. The safety of operating reactors is further insured through close regulation of license changes and selective backfitting of new regulatory requirements. An effective NRC standards development program has been implemented and coordinates closely with the national standards program. A confirmatory safety research program has been developed. Both of these efforts are invaluable to the nuclear safety review because they provide the staff with key tools needed to carry out its regulatory responsibilities. Both have been given increased emphasis since the formation of the NRC in 1975. The safety review process will continue to evolve, but changes will be slower and more deliberate. It will be influenced by standardization, early site reviews and development of advanced reactor concepts. New legislation may make possible changes which will simplify and shorten the regulatory process. Certainly the experience provided by the increasing number and types of operating plants will have a very strong impact on future trends in the

Top quark discovered

International Nuclear Information System (INIS)

Anon.

1995-01-01

Nine months after a careful announcement of tentative evidence for the long-awaited sixth 'top' quark, physicists from the CDF and DO experiments at Fermilab's Tevatron proton-antiproton collider declared on 2 March that they had finally discovered the top quark. Last year (June 1994, page 1), the CDF experiment at the Tevatron reported a dozen candidate top events. These, said CDF, had all the characteristics expected of top, but the difficulties of extracting the tiny signal from a trillion proton-antiproton collisions made them shy of claiming a discovery. For its part, the companion DO Tevatron experiment reported a few similar events but were even more guarded about their interpretation as top quarks. Just after these hesitant announcements, performance at the Tevatron improved dramatically last summer. After the commissioning of a new linear accelerator and a magnet realignment, the machine reached a new world record proton-antiproton collision luminosity of 1.28 x 10 31 per sq cm per s, ten times that originally planned. Data began to pour in at an unprecedented rate and the data sample grew to six trillion collisions. Luminosity has subsequently climbed to 1.7 x 10 31 . The top quark is the final letter in the alphabet of Standard Model particles. According to this picture, all matter is composed of six stronglyinteracting subnuclear particles, the quarks, and six weakly interacting particles, the leptons. Both sextets are neatly arranged as three pairs in order of increasing mass. The fifth quark, the 'beauty' or 'b' quark, was also discovered at Fermilab, back in 1977. Since then physicists have been eagerly waiting for the top to turn up, but have been frustrated by its heaviness - the top is some 40 times the mass of its 'beautiful' partner. Not only is the top quark the heaviest by far, but it is the only quark which has been actively hunted. After the quarry was glimpsed last year, the net has now been

Renal studies in safety pharmacology and toxicology: A survey conducted in the top 15 pharmaceutical companies.

Science.gov (United States)

Benjamin, Amanda; Gallacher, David J; Greiter-Wilke, Andrea; Guillon, Jean-Michel; Kasai, Cheiko; Ledieu, David; Levesque, Paul; Prelle, Katja; Ratcliffe, Sian; Sannajust, Frederick; Valentin, Jean-Pierre

2015-01-01

With the recent development of more sensitive biomarkers to assess kidney injury preclinically, a survey was designed i) to investigate what strategies are used to investigate renal toxicity in both ICH S7A compliant Safety Pharmacology (SP) studies after a single dose of a compound and within repeat-dose toxicity studies by large pharmaceutical companies today; ii) to understand whether renal SP studies have impact or utility in drug development and/or if it may be more appropriate to assess renal effects after multiple doses of compounds; iii) to ascertain how much mechanistic work is performed by the top 15 largest pharmaceutical companies (as determined by R&D revenue size); iv) to gain an insight into the impact of the validation of DIKI biomarkers and their introduction in the safety evaluation paradigm; and v) to understand the impact of renal/urinary safety study data on progression of projects. Two short anonymous surveys were submitted to SP leaders of the top 15 pharmaceutical companies, as defined by 2012 R&D portfolio size. Fourteen multiple choice questions were designed to explore the strategies used to investigate renal effects in both ICH S7A compliant SP studies and within toxicology studies. A 67% and 60% response rate was obtained in the first and second surveys, respectively. Nine out of ten respondent companies conduct renal excretory measurements (eg. urine analysis) in toxicology studies whereas only five out of ten conduct specific renal SP studies; and all of those 5 also conduct the renal excretory measurements in toxicology studies. These companies measure and/or calculate a variety of parameters as part of these studies, and also on a case by case basis include regulatory qualified and non-qualified DIKI biomarkers. Finally, only one company has used renal/urinary functional data alone to stop a project, whereas the majority of respondents combine renal data with other target organ assessments to form an integrated decision-making set

Program of nuclear criticality safety experiment at JAERI

International Nuclear Information System (INIS)

Kobayashi, Iwao; Tachimori, Shoichi; Takeshita, Isao; Suzaki, Takenori; Ohnishi, Nobuaki

1983-11-01

JAERI is promoting the nuclear criticality safety research program, in which a new facility for criticality safety experiments (Criticality Safety Experimental Facility : CSEF) is to be built for the experiments with solution fuel. One of the experimental researches is to measure, collect and evaluate the experimental data needed for evaluation of criticality safety of the nuclear fuel cycle facilities. Another research area is a study of the phenomena themselves which are incidental to postulated critical accidents. Investigation of the scale and characteristics of the influences caused by the accident is also included in this research. The result of the conceptual design of CSEF is summarized in this report. (author)

Electroweak production of the top quark in the Run 2 of the D0 experiment; Production electrofaible du quark top au Run 2 de l'experience D0

Energy Technology Data Exchange (ETDEWEB)

Clement, B

2006-04-15

The work exposed in this thesis deals with the search for electroweak production of top quark (single top) in proton-antiproton collisions at {radical}s = 1.96 TeV. This production mode has not been observed yet. Analyzed data have been collected during the Run II of the D diameter experiment at the Fermilab Tevatron collider. These data correspond to an integrated luminosity of 370 pb{sup -1}. In the Standard Model, the decay of a top quark always produce a high momentum bottom quark. Therefore bottom quark jets identification plays a major role in this analysis. The large lifetime of b hadrons and the subsequent large impact parameters relative to the interaction vertex of charged particle tracks are used to tag bottom quark jets. Impact parameters of tracks attached to a jet are converted into the probability for the jet to originate from the primary vertex. This algorithm has a 45% tagging efficiency for a 0.5% mistag rate. Two processes (s and t channels) dominate single top production with slightly different final states. The searched signature consists in 2 to 4 jets with at least one bottom quark jet, one charged lepton (electron or muon) and missing energy accounting for a neutrino. This final state is background dominated and multivariate techniques are needed to separate the signal from the two main backgrounds: associated production of a W boson and jets and top quarks pair production. The achieved sensitivity is not enough to reach observation and we computed upper limits at the 95% confidence level at 5 pb (s-channel) and 4.3 pb (t-channel) on single top production cross-sections. (author)

Continuous Distributed Top-k Monitoring over High-Speed Rail Data Stream in Cloud Computing Environment

Directory of Open Access Journals (Sweden)

Hanning Wang

2013-01-01

Full Text Available In the environment of cloud computing, real-time mass data about high-speed rail which is based on the intense monitoring of large scale perceived equipment provides strong support for the safety and maintenance of high-speed rail. In this paper, we focus on the Top-k algorithm of continuous distribution based on Multisource distributed data stream for high-speed rail monitoring. Specifically, we formalized Top-k monitoring model of high-speed rail and proposed DTMR that is the Top-k monitoring algorithm with random, continuous, or strictly monotone aggregation functions. The DTMR was proved to be valid by lots of experiments.

CDF Top Physics

Science.gov (United States)

Tartarelli, G. F.; CDF Collaboration

1996-05-01

The authors present the latest results about top physics obtained by the CDF experiment at the Fermilab Tevatron collider. The data sample used for these analysis (about 110 pb{sup{minus}1}) represents almost the entire statistics collected by CDF during four years (1992--95) of data taking. This large data size has allowed detailed studies of top production and decay properties. The results discussed here include the determination of the top quark mass, the measurement of the production cross section, the study of the kinematics of the top events and a look at top decays.

Top quark physics at the D0 experiment

International Nuclear Information System (INIS)

Heinson, A.P.

1996-01-01

In this paper I present the latest results on top quark physics from the D0 collaboration since the discovery of the top quark in March 1995. I summarize the discovery results, discuss progress since the discovery, and show how we can measure the top quark mass using three separate techniques. The measurements were made at the Fermilab Tevatron, a p bar p collider with √s = TeV, using ∼50 pb -1 data collected from 1992 to early 1995

Developing and Strengthening of Safety Culture at Ukrainian NPPs: Experience of NNEGC “Energoatom”

International Nuclear Information System (INIS)

Sheyko, Y.; Kotin, P.

2016-01-01

The moratorium, which was introduced in Ukraine after the Chernobyl accident, for the construction of new nuclear power plants at the legislative level, was broken in 2004, when two new power units at Khmelnytsky and Rivne nuclear power plant were put into operation. Currently, the nuclear energy sector plays the main role for electric power industry of Ukraine. Ukraine has the intention to finish the construction of two new units at the Khmelnitsky nuclear power plant. NAEC “Energoatom”, as the operating organization, is aware that the attitude and behavior of top management as well as organizational features and activities have a significant impact on the safety culture. In the management statement dedicated to nuclear safety establishment, NAEC declares the absolute priority of safety over other objectives, in accordance with the principles of safety culture. Beginning with 2009, in scope with the IAEA recommendations, and based on the introduced in Ukraine in 2008 of the new revision of safety rules “General Safety of nuclear power plants”, NAEC “Energoatom” activities for improving the safety culture are being carried out under special programs. There are three levels of management for this activities: • Council on safety culture (top management); • Working Group (representatives of all divisions of NAEC); • Committees on safety culture (all NPP sites). The programs are developed and updated every two years and the implementation of measures is provided on three levels of responsibility: • Technical policy for the safety; • responsibility and leadership obligations; • personal responsibility and duties of every employee. The main achievement of these programs has been to define and establish the strategy and a set of permanent measures which are aimed at improving the safety culture. On the basis of corporate programs the plants developed the programs of concrete actions aimed at the establishment and development of a safety culture

ICSBEP-2007, International Criticality Safety Benchmark Experiment Handbook

International Nuclear Information System (INIS)

Blair Briggs, J.

2007-01-01

1 - Description: The Critically Safety Benchmark Evaluation Project (CSBEP) was initiated in October of 1992 by the United Sates Department of Energy. The project quickly became an international effort as scientist from other interested countries became involved. The International Criticality Safety Benchmark Evaluation Project (ICSBEP) is now an official activity of the Organization of Economic Cooperation and Development - Nuclear Energy Agency (OECD-NEA). This handbook contains criticality safety benchmark specifications that have been derived from experiments that were performed at various nuclear critical facilities around the world. The benchmark specifications are intended for use by criticality safety engineers to validate calculational techniques used to establish minimum subcritical margins for operations with fissile material. The example calculations presented do not constitute a validation of the codes or cross section data. The work of the ICSBEP is documented as an International Handbook of Evaluated Criticality Safety Benchmark Experiments. Currently, the handbook spans over 42,000 pages and contains 464 evaluations representing 4,092 critical, near-critical, or subcritical configurations and 21 criticality alarm placement/shielding configurations with multiple dose points for each and 46 configurations that have been categorized as fundamental physics measurements that are relevant to criticality safety applications. The handbook is intended for use by criticality safety analysts to perform necessary validations of their calculational techniques and is expected to be a valuable tool for decades to come. The ICSBEP Handbook is available on DVD. You may request a DVD by completing the DVD Request Form on the internet. Access to the Handbook on the Internet requires a password. You may request a password by completing the Password Request Form. The Web address is: http://icsbep.inel.gov/handbook.shtml 2 - Method of solution: Experiments that are found

Use of safety experience feedback to design new nuclear units

International Nuclear Information System (INIS)

Lange, D.; Crochon, J.P.

1985-06-01

For the designer, and about safety, the experience feedback can take place in 3 fields: the operating experience feedback (incidents analysis), the ''study'' experience feedback (improvement of justification and evolution of safety considerations), and the fabrication experience feedback. Some examples are presented for each field [fr

LMFBR operational safety: the EBR-II experience

International Nuclear Information System (INIS)

Sackett, J.I.; Allen, N.L.; Dean, E.M.; Fryer, R.M.; Larson, H.A.; Lehto, W.K.

1978-01-01

The mission of the Experimental Breeder Reactor II (EBR-II) has evolved from that of a small LMFBR demonstration plant to a major irradiation-test facility. Because of that evolution, many operational-safety issues have been encountered. The paper describes the EBR-II operational-safety experience in four areas: protection-system design, safety-document preparation, tests of off-normal reactor conditions, and tests of elements with breached cladding

Safety experience on EDF's PWRs

International Nuclear Information System (INIS)

Tanguy, P.

1986-01-01

The french nuclear programme has been widely publicized. In 1985, the total nuclear electricity generated was around 216 GWh, i. e. 70% of the electricity produced by electricity de France (EDF). If we consider only pressurized water reactors, at the end of 1985, 37 units were in operation (32 900 MWe and 5 1300 MWe) and 18 were under construction. I intend to review our experience with the safety of PWR's, but I will first present briefly some aspects related to the safety organization in France and the standardization policy. (author) [pt

Proceedings of TopSafe 2008 Transactions

International Nuclear Information System (INIS)

2008-01-01

The aim of the conference is to provide a forum for addressing the current status and future perspectives with regards to safety at nuclear installations worldwide. Previous TopSafe editions took place in Budapest (1995) and Valencia (1998). The conference is directed at a broad range of experts in the area of nuclear safety, including professionals from the different disciplines involved in the safety of nuclear power plants, installations in other parts of the fuel cycle, and research reactors. It is aimed at professionals coming from the research organisations, universities, vendors, operators, regulatory bodies as well as policy makers. Top level representatives of the Countries that are constructing new nuclear power plants are invited. Regulators of all individual Countries with nuclear programme are expected to contribute the Conference. The topics of the conference are: Safety Issues of Operating Power Plants PWR and BWR, CANDU, WWER, RBMK; Application of European Utilities Requirements; Probabilistic and Deterministic Analysis; Shutdown Safety; Advances in Safety: Analysis Codes and Techniques; Severe Accidents Management; International Safety Studies; Emergency Planning; Risk Informed Application and Licensing; Regulatory Safety Requirements; Ageing and Life Extension; Power Upgrades and Relevant Topics; Management of Safety and Quality; Safety Culture and Self Assessment; Political and Public Perception of Nuclear Energy; Nuclear Power Plant Security; Safety Issues of Future Power Plants-Near term deployment reactors (EPR, SWR1000, AP1000, ESBWR, SBWR, ACR-1000) and Generation IV reactors; Safety Issues of Research Reactors (pool type and others); Fuel Cycle Facilities Safety-Uranium mining and conversion, enrichment and fuel production, reprocessing and transmutation, waste disposal. (authors)

Providing Nuclear Criticality Safety Analysis Education through Benchmark Experiment Evaluation

International Nuclear Information System (INIS)

Bess, John D.; Briggs, J. Blair; Nigg, David W.

2009-01-01

One of the challenges that today's new workforce of nuclear criticality safety engineers face is the opportunity to provide assessment of nuclear systems and establish safety guidelines without having received significant experience or hands-on training prior to graduation. Participation in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and/or the International Reactor Physics Experiment Evaluation Project (IRPhEP) provides students and young professionals the opportunity to gain experience and enhance critical engineering skills.

Glovebox and Experiment Safety

Science.gov (United States)

Maas, Gerard

2005-12-01

Human spaceflight hardware and operations must comply with NSTS 1700.7. This paper discusses how a glovebox can help.A short layout is given on the process according NSTS/ISS 13830, explaining the responsibility of the payload organization, the approval authority of the PSRP and the defined review phases (0 till III).Amongst others, the following requirement has to be met:"200.1 Design to Tolerate Failures. Failure tolerance is the basic safety requirement that shall be used to control most payload hazards. The payload must tolerate a minimum number of credible failures and/or operator errors determined by the hazard level. This criterion applies when the loss of a function or the inadvertent occurrence of a function results in a hazardous event.200.1a Critical Hazards. Critical hazards shall be controlled such that no single failure or operator error can result in damage to STS/ISS equipment, a nondisabling personnel injury, or the use of unscheduled safing procedures that affect operations of the Orbiter/ISS or another payload.200.1b Catastrophic Hazards. Catastrophic hazards shall be controlled such that no combination of two failures or operator errors can result in the potential for a disabling or fatal personnel injury or loss of the Orbiter/ISS, ground facilities or STS/ISS equipment."For experiments in material science, biological science and life science that require real time operator manipulation, the above requirement may be hard or impossible to meet. Especially if the experiment contains substances that are considered hazardous when released into the habitable environment. In this case operation of the experiment in a glovebox can help to comply.A glovebox provides containment of the experiment and at the same time allows manipulation and visibility to the experiment.The containment inside the glovebox provides failure tolerance because the glovebox uses a negative pressure inside the working volume (WV). The level of failure tolerance is dependent of

Large Scale Experiments on Spacecraft Fire Safety

Science.gov (United States)

Urban, David; Ruff, Gary A.; Minster, Olivier; Fernandez-Pello, A. Carlos; Tien, James S.; Torero, Jose L.; Legros, Guillaume; Eigenbrod, Christian; Smirnov, Nickolay; Fujita, Osamu;

In-pile experiments and test facilities proposed for fast reactor safety

International Nuclear Information System (INIS)

Grolmes, M.A.; Avery, R.; Goldman, A.J.; Fauske, H.K.; Marchaterre, J.F.; Rose, D.; Wright, A.E.

1976-01-01

The role of in-pile experiments in support of the resolution of fast breeder reactor safety and licensing issues has been re-examined, with emphasis on key safety issues. Experiment needs have been related to the specific characteristics of these safety issues and to realistic requirements for additional test facility capabilities which can be achieved and utilized within the next ten years. It is found that those safety issues related to the energetics of core disruptive accidents have the largest impact on new facility requirements. However, utilization of existing facilities with modifications can provide for a continuing increase in experiment capability and experiment results on a timely bases. Emphasis has been placed upon maximum utilization of existing facilities and minimum requirements for new facilities. This evaluation has concluded that a new Safety Test Facility, STF, along with major modifications to the EBR II facility, improvement in TREAT capabilities, the existing Sodium Loop Safety Facility and corresponding Support Facilities provide the essential elements of the Safety Research Experiment Facilities (SAREF) required for resolution of key issues

International handbook of evaluated criticality safety benchmark experiments

International Nuclear Information System (INIS)

2010-01-01

The Criticality Safety Benchmark Evaluation Project (CSBEP) was initiated in October of 1992 by the United States Department of Energy. The project quickly became an international effort as scientists from other interested countries became involved. The International Criticality Safety Benchmark Evaluation Project (ICSBEP) became an official activity of the Organization for Economic Cooperation and Development - Nuclear Energy Agency (OECD-NEA) in 1995. This handbook contains criticality safety benchmark specifications that have been derived from experiments performed at various nuclear critical facilities around the world. The benchmark specifications are intended for use by criticality safety engineers to validate calculational techniques used to establish minimum subcritical margins for operations with fissile material and to determine criticality alarm requirement and placement. Many of the specifications are also useful for nuclear data testing. Example calculations are presented; however, these calculations do not constitute a validation of the codes or cross section data. The evaluated criticality safety benchmark data are given in nine volumes. These volumes span over 55,000 pages and contain 516 evaluations with benchmark specifications for 4,405 critical, near critical, or subcritical configurations, 24 criticality alarm placement / shielding configurations with multiple dose points for each, and 200 configurations that have been categorized as fundamental physics measurements that are relevant to criticality safety applications. Experiments that are found unacceptable for use as criticality safety benchmark experiments are discussed in these evaluations; however, benchmark specifications are not derived for such experiments (in some cases models are provided in an appendix). Approximately 770 experimental configurations are categorized as unacceptable for use as criticality safety benchmark experiments. Additional evaluations are in progress and will be

ABWR (K-6/7) construction experience (computer-based safety system)

International Nuclear Information System (INIS)

Yokomura, T.

1998-01-01

TEPCO applied a digital safety system to Kashiwazaki-Kariwa Nuclear Power Station Unit Nos. 6 and 7, the world's first ABWR plant. Although this was the first time to apply a digital safety logic system in Japan, we were able to complete construction of K-6/7 very successfully and without any delay. TEPCO took a approach of developing a substantial amount of experience in digital non- safety systems before undertaking the design of the safety protection system. This paper describes the history, techniques and experience behind achieving a highly reliable digital safety system. (author)

PNRA Process for Utilizing Experience Feedback for Enhancing Nuclear Safety

International Nuclear Information System (INIS)

Shah, Z.H.

2016-01-01

One of the elements essential for any organization to become a learning organization is to learn from its own and others experience. The importance of utilizing experience feedback for enhancing operational safety is highlighted in nuclear industry again and again and this has resulted in establishment of several national and international forums. In addition, IAEA action plan on nuclear safety issued after Fukushima accident further highlighted the importance of experience sharing among nuclear community to enhance global nuclear safety regime. PNRA utilizes operating experience feedback gathered through different sources in order to improve its regulatory processes. During the review of licensing submissions, special emphasis is given to utilize the lessons learnt from experience feedback relating to nuclear industry within and outside the country. This emphasis has gradually resulted in various safety improvements in the facilities and processes. Accordingly, PNRA has developed a systematic process of evaluation of international operating experience feedback with the aim to create safety conscious approach. This process includes collecting information from different international forums such as IAEA, regulatory bodies of other countries and useful feedback of past accidents followed by its screening, evaluation and suggesting recommendations both for PNRA and its licensees. As a result of this process, several improvements concerning regulatory inspection plans of PNRA as well as in regulatory decision making and operational practices of licensees have been highlighted. This paper will present PNRA approach for utilizing experience feedback in its regulatory processes for enhancing / improving nuclear safety. (author)

TopFuel 2003 conference report

International Nuclear Information System (INIS)

Anon.

2003-01-01

The international conference, TopFuel 2003 - Nuclear Fuel for Today and Tomorrow, Experience and Outlook, was held in Wuerzburg on March 16-19, 2003. The event, which was organized jointly by the Atomic Energy Society of Japan (AESJ), the American Nuclear Society (ANS), the German Nuclear Society and the European Nuclear Society (ENS), provided a comprehensive overview of current topics and developments in nuclear fuel supply in more than ninety papers and poster presentations. At the plenary session, more than 300 participants from 15 countries discussed basic problems of nuclear fuel development, safety research, strategies of nuclear fuel supply in the 21st century, fuel fabrication, interim storage of fuel elements, and problems of fuel element design for nuclear power plants of the next generation. Seven technical sessions dealt with other topical developments in these fields: - feedback of experience in fuel use, - nuclear fuel cycle efforts to increase burnup, - trends in nuclear fuel design, - advanced methods and codes, - fabrication, - transport, nuclear fuel services. (orig.) [de

Safety in the c-suite: How chief executive officers influence organizational safety climate and employee injuries.

Science.gov (United States)

Tucker, Sean; Ogunfowora, Babatunde; Ehr, Dayle

2016-09-01

According to social learning theory, powerful and high status individuals can significantly influence the behaviors of others. In this paper, we propose that chief executive officers (CEOs) indirectly impact frontline injuries through the collective social learning experiences and effort of different groups of organizational actors-including members of the top management team (TMT), organizational supervisors, and frontline employees. We found support for our collective social learning model using data from 2,714 frontline employees, 1,398 supervisors, and 229 members of TMTs in 54 organizations. TMT members' experiences within a CEO-driven TMT safety climate was positively related to organizational supervisors' reports of the broader organizational safety climate and their subsequent collective support for safety (reported by frontline employees). In turn, supervisory support for safety was associated with fewer employee injuries at the individual level. We discuss the theoretical and practical implications of these findings for workplace safety research and practice. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Experiences of abortion: A narrative review of qualitative studies

Directory of Open Access Journals (Sweden)

May Carl R

2008-07-01

Full Text Available Abstract Background Although abortion or termination of pregnancy (TOP has become an increasingly normalized component of women's health care over the past forty years, insufficient attention has been paid to women's experiences of surgical or medical methods of TOP. Objective To undertake a narrative review of qualitative studies of women's experiences of TOP and their perspectives on surgical or medical methods. Methods Keyword searches of Medline, CINAHL, ISI, and IBSS databases. Manual searches of other relevant journals and reference lists of primary articles. Results Qualitative studies (n = 18 on women's experiences of abortion were identified. Analysis of the results of studies reviewed revealed three main themes: experiential factors that promote or inhibit the choice to seek TOP; experiences of TOP; and experiential aspects of the environment in which TOP takes place. Conclusion Women's choices about TOP are mainly pragmatic ones that are related to negotiating finite personal and family and emotional resources. Women who are well informed and supported in their choices experience good psychosocial outcomes from TOP. Home TOP using mifepristone appears attractive to women who are concerned about professionals' negative attitudes and lack of privacy in formal healthcare settings but also leads to concerns about management and safety.

Top Quark Properties at Tevatron

Energy Technology Data Exchange (ETDEWEB)

Lysák, Roman [Prague, Inst. Phys.

2017-11-27

The latest CDF and D0 experiment measurements of the top quark properties except the top quark mass are presented. The final combination of the CDF and D0 forward-backward asymmetry measurements is shown together with the D0 measurements of the inclusive top quark pair cross-section as well as the top quark polarization.

The experiences of research reactor accident to safety improvement

International Nuclear Information System (INIS)

Wiranto, S.

1999-01-01

The safety of reactor operation is the main factor in order that the nuclear technology development program can be held according the expected target. Several experience with research reactor incidents must be learned and understood by the nuclear program personnel, especially for operators and supervisors of RSG-GA. Siwabessy. From the incident experience of research reactor in the world, which mentioned in the book 'Experience with research reactor incidents' by IAEA, 1995, was concluded that the main cause of research reactor accidents is understandless about the safety culture by the nuclear installation personnel. With learn, understand and compare between this experiences and the condition of RSG GA Siwabessy is expended the operators and supervisors more attention about the safety culture, so that RSG GA Siwabessy can be operated successfull, safely according the expected target

Potential impact on food safety and food security from persistent organic pollutants in top soil improvers on Mediterranean pasture

International Nuclear Information System (INIS)

Brambilla, G.; Abate, V.; Battacone, G.; De Filippis, S.P.; Esposito, M.; Esposito, V.; Miniero, R.

2016-01-01

The organic carbon of biosolids from civil wastewater treatment plants binds persistent organic pollutants (POPs), such as polychlorodibenzo -dioxins and -furans (PCDD/Fs), dioxin and non-dioxin -like polychlorobiphenyls (DL and NDL-PCBs), polybrominated diphenyl ethers (PBDEs), and perfluorooctane sulfonic acid (PFOS). The use of such biosolids, derived digestates and composts as top soil improvers (TSIs) may transfer POPs into the food chain. We evaluated the potential carry-over of main bioavailable congeners from amended soil-to-milk of extensive farmed sheep. Such estimates were compared with regulatory limits (food security) and human intakes (food safety). The prediction model was based on farming practices, flocks soil intake, POPs toxicokinetics, and dairy products intake in children, of the Mediterranean area. TSI contamination ranged between 0.20–113 ng WHO-TEQ/kg dry matter for PCDD/Fs and DL-PCBs (N = 56), 3.40–616 μg/kg for ∑_6 NDL-PCBs (N = 38), 0.06–17.2 and 0.12–22.3 μg/kg for BDE no. 47 and no. 99, 0.872–89.50 μg/kg for PFOS (N = 27). For a 360 g/head/day soil intake of a sheep with an average milk yield of 2.0 kg at 6.5% of fat percentage, estimated soil quality standards supporting milk safety and security were 0.75 and 4.0 ng WHO-TEQ/kg for PCDD/Fs and DL-PCBs, and 3.75 and 29.2 μg/kg for ∑_6 NDL-PCBs, respectively. The possibility to use low-contaminated TSIs to maximize agriculture benefits and if the case, to progressively mitigate highly contaminated soils is discussed. - Highlights: • Top soil improvers were characterized for selected POPs content, in Italy. • Grazing behaviour makes sheep sensitive to top soil contamination. • Environmental quality standards for grazing areas were modelled • The impact on Mediterranean sheep milk safety/security was evaluated. • Low contaminated TSIs support safe intake and compliance of dairy products.

Potential impact on food safety and food security from persistent organic pollutants in top soil improvers on Mediterranean pasture

Energy Technology Data Exchange (ETDEWEB)

Brambilla, G.; Abate, V. [Istituto Superiore di sanità, Veterinary Public Health Dept, Viale Regina Elena 299, 00161 Rome (Italy); Battacone, G. [Università degli Studi di Sassari, Agricultural Science, Viale Italia, 39 07100 Sassari (Italy); De Filippis, S.P. [Istituto Superiore di sanità, Toxicological Chemistry Unit, Viale Regina Elena 299, 00161 Rome (Italy); Esposito, M. [Istituto Zooprofilattico Sperimentale del Mezzogiorno, Via Salute 2, 08055 Portici, (Neaples) (Italy); Esposito, V. [Agenzia Regionale Per la Protezione dell' Ambiente Regione Puglia, Via Anfiteatro 8, 74100 Taranto (Italy); Miniero, R. [Istituto Superiore di sanità, Toxicological Chemistry Unit, Viale Regina Elena 299, 00161 Rome (Italy)

2016-02-01

The organic carbon of biosolids from civil wastewater treatment plants binds persistent organic pollutants (POPs), such as polychlorodibenzo -dioxins and -furans (PCDD/Fs), dioxin and non-dioxin -like polychlorobiphenyls (DL and NDL-PCBs), polybrominated diphenyl ethers (PBDEs), and perfluorooctane sulfonic acid (PFOS). The use of such biosolids, derived digestates and composts as top soil improvers (TSIs) may transfer POPs into the food chain. We evaluated the potential carry-over of main bioavailable congeners from amended soil-to-milk of extensive farmed sheep. Such estimates were compared with regulatory limits (food security) and human intakes (food safety). The prediction model was based on farming practices, flocks soil intake, POPs toxicokinetics, and dairy products intake in children, of the Mediterranean area. TSI contamination ranged between 0.20–113 ng WHO-TEQ/kg dry matter for PCDD/Fs and DL-PCBs (N = 56), 3.40–616 μg/kg for ∑{sub 6} NDL-PCBs (N = 38), 0.06–17.2 and 0.12–22.3 μg/kg for BDE no. 47 and no. 99, 0.872–89.50 μg/kg for PFOS (N = 27). For a 360 g/head/day soil intake of a sheep with an average milk yield of 2.0 kg at 6.5% of fat percentage, estimated soil quality standards supporting milk safety and security were 0.75 and 4.0 ng WHO-TEQ/kg for PCDD/Fs and DL-PCBs, and 3.75 and 29.2 μg/kg for ∑{sub 6} NDL-PCBs, respectively. The possibility to use low-contaminated TSIs to maximize agriculture benefits and if the case, to progressively mitigate highly contaminated soils is discussed. - Highlights: • Top soil improvers were characterized for selected POPs content, in Italy. • Grazing behaviour makes sheep sensitive to top soil contamination. • Environmental quality standards for grazing areas were modelled • The impact on Mediterranean sheep milk safety/security was evaluated. • Low contaminated TSIs support safe intake and compliance of dairy products.

Search for Electroweak Single-Top Quark Production with the CDF II Experiment

Energy Technology Data Exchange (ETDEWEB)

Buehler, Matthias; /Karlsruhe U., EKP

2006-08-01

The CDF II experiment and the Tevatron proton-antiproton collider are parts of the Fermi National Laboratories (Fermilab). The Fermilab is located in the vicinity of Chicago, USA. Today, the Tevatron is the only collider which is able to produce the heaviest known elementary particle, the top quark. The top quark was discovered at the Tevatron by the CDF and the D0 collaborations in 1995 [1]. So far, all the top quarks found are produced via the strong interaction as top-antitop pairs. The Standard Model of elementary particle physics also predicts single-top quark production via the electroweak interaction. This production mode has not yet been observed. The CDF and the D0 collaborations have set upper limits on the cross section for that process in Run I [2, 3] and improved those results in Run II [4, 5]. Single-top quark production is one of the major interests in Run II of the Tevatron as it offers several ways to test the Standard Model and to search for potential physics beyond the Standard Model. The measurement of the cross section of singly produced top quarks via the electroweak interaction offers the possibility to determine the Cabbibo-Kobayashi-Maskawa (CKM) matrix element V{sub tb} directly. The CKM matrix defines the transformation from the eigenstates of the electroweak interactions to the mass eigenstates of the quarks. V{sub tb} gives the strength of the coupling at the Wtb vertex. The single-top quark is produced at this vertex and therefore the cross section of the single-top quark production is directly proportional to |V{sub tb}|{sup 2}. In the Standard Model, three generations of quarks and the unitarity of the CKM matrix are predicted. This leads to V{sub tb} {approx} 1. Up to now, there is no possibility to measure V{sub tb} without using the assumption that there are a certain number of quark generations. Since the measurement of the cross section of single-top quark production is independent of this assumption it could verify another

HTR-PM Safety requirement and Licensing experience

International Nuclear Information System (INIS)

Li Fu; Zhang Zuoyi; Dong Yujie; Wu Zongxin; Sun Yuliang

2014-01-01

HTR-PM is a 200MWe modular pebble bed high temperature reactor demonstration plant which is being built in Shidao Bay, Weihai, Shandong, China. The main design parameters of HTR-PM were fixed in 2006, the basic design was completed in 2008. The review of Preliminary Safety Analysis Report (PSAR) of HTR-PM was started in April 2008, completed in September 2009. In general, HTR- PM design complies with the current safety requirement for nuclear power plant in China, no special standards are developed for modular HTR. Anyway, Chinese Nuclear Safety Authority, together with the designers, developed some dedicated design criteria for key systems and components and published the guideline for the review of safety analysis report of HTR-PM, based on the experiences from licensing of HTR-10 and new development of nuclear safety. The probabilistic safety goal for HTR-PM was also defined by the safety authority. The review of HTR-PM PSAR lasted for one and a half years, with 3 dialogues meetings and 8 topics meetings, with more than 2000 worksheets and answer sheets. The heavily discussed topics during the PSAR review process included: the requirement for the sub-atmospheric ventilation system, the utilization of PSA in design process, the scope of beyond design basis accidents, the requirement for the qualification of TRISO coating particle fuel, and etc. Because of the characteristics of first of a kind for the demonstration plant, the safety authority emphasized the requirement for the experiment and validation, the PSAR was licensed with certain licensing conditions. The whole licensing process was under control, and was re-evaluated again after Fukushima accident to be shown that the design of HTR-PM complies with current safety requirement. This is a good example for how to license a new reactor. (author)

Creating a safety culture in the regulatory authority: The Cuban experience

International Nuclear Information System (INIS)

Ferro Fernandez, R.; Guillen Campos, A.

2002-01-01

The Cuban regulatory authority has been working during several years for the fostering and development of a high Safety Culture level in nuclear activities in the country. As starting point to achieve this objective the assessment of the Safety Culture level in the regulatory authority performance was considered an important issue. For this purpose a preliminary diagnosis was carried out by means of a national survey that allowed identifying some areas of the regulatory activity that required improvements in order to achieve a higher Safety Culture and to immediately implement appropriate actions. Two of the most important actions undertaken were: the statement of the regulatory authority Safety Policy which governs and determines the performance of this organization and its staff and also the implementation of a new interaction practice at top level between the regulatory authority and the utilities of the nuclear sector through the Annual Regulatory Conference. The present paper summarizes these two introduced practices into the Cuban regulatory activity. (author)

Introduction to 'International Handbook of Criticality Safety Benchmark Experiments'

International Nuclear Information System (INIS)

Komuro, Yuichi

1998-01-01

The Criticality Safety Benchmark Evaluation Project (CSBEP) was initiated in 1992 by the United States Department of Energy. The project quickly became an international effort as scientists from other interested countries became involved. The International Criticality Safety Benchmark Evaluation Project (ICSBEP) is now an official activity of the Organization for Economic Cooperation and Development-Nuclear Energy Agency (OECD-NEA). 'International Handbook of Criticality Safety Benchmark Experiments' was prepared and is updated year by year by the working group of the project. This handbook contains criticality safety benchmark specifications that have been derived from experiments that were performed at various nuclear critical facilities around the world. The benchmark specifications are intended for use by criticality safety engineers to validate calculation techniques used. The author briefly introduces the informative handbook and would like to encourage Japanese engineers who are in charge of nuclear criticality safety to use the handbook. (author)

Studies on top-quark Monte Carlo modelling for Top2016

CERN Document Server

The ATLAS collaboration

2016-01-01

This note summarises recent studies on Monte Carlo simulation setups of top-quark pair production used by the ATLAS experiment and presents a new method to deal with interference effects for the $Wt$ single-top-quark production which is compared against previous techniques. The main focus for the top-quark pair production is on the improvement of the modelling of the Powheg generator interfaced to the Pythia8 and Herwig7 shower generators. The studies are done using unfolded data at centre-of-mass energies of 7, 8, and 13 TeV.

Survey of Safety Climate in a Petrochemical Industry in Mahshahr

Directory of Open Access Journals (Sweden)

Y. Shokoohi

2012-07-01

Results and Discussion: Average score of the industry's safety climate was obtained 5.9. Of 17 studied dimensions, 9 dimensions were weak (score less than 6. Lowest score were related to Event & Accident and Change management dimensions. Highest score were related to Individual priorities and need for safety (8.65. Generally relationship between individual variables (ages, work experience, education and safety climate were not significant (P>0.05. Conclusion: Generally one can conclude that individual variables such as age, education and experience have not significant effect on safety climate. It seems that top management forms the organizational climate and consequently safety climate. It reaffirms the basic principle of senior management commitment to safety and its role in preventing accidents. Thus safety climate can be used as a good method for assessing Occupational Health and Safety Management Performance.

The TopHat experiment: A balloon-borne instrument for mapping millimeter and submillimeter emission

DEFF Research Database (Denmark)

Silverberg, R.F.; Cheng, E.S.; Aguirre, J.E.

2005-01-01

The TopHat experiment was designed to measure the anisotropy in the cosmic microwave background radiation on angular scales from 0.degrees 3 to 30 degrees and the thermal emission from both Galactic and extragalactic dust. The balloon-borne instrument had five spectral bands spanning frequencies ...

Nuclear safety policy working group recommendations on nuclear propulsion safety for the space exploration initiative

Science.gov (United States)

Marshall, Albert C.; Lee, James H.; Mcculloch, William H.; Sawyer, J. Charles, Jr.; Bari, Robert A.; Cullingford, Hatice S.; Hardy, Alva C.; Niederauer, George F.; Remp, Kerry; Rice, John W.

1993-01-01

An interagency Nuclear Safety Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program. These recommendations, which are contained in this report, should facilitate the implementation of mission planning and conceptual design studies. The NSPWG has recommended a top-level policy to provide the guiding principles for the development and implementation of the SEI nuclear propulsion safety program. In addition, the NSPWG has reviewed safety issues for nuclear propulsion and recommended top-level safety requirements and guidelines to address these issues. These recommendations should be useful for the development of the program's top-level requirements for safety functions (referred to as Safety Functional Requirements). The safety requirements and guidelines address the following topics: reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, safeguards, risk/reliability, operational safety, ground testing, and other considerations.

Safety engineering experiments of explosives

Energy Technology Data Exchange (ETDEWEB)

Ishikawa, Noboru

1987-07-24

The outline of large scale experiments carried out every year since 1969 to obtain fundamental data and then establish the safety engineering standards concerning the manufacturing, storage and transportation, etc. of all explosives was described. Because it becomes recently difficult to ensure the safety distance in powder magazines and powder plants, the sandwich structure with sand is thought to be suitable as the neighboring barrier walls. The special vertical structure for embankments to provide against a emergency explosion is effective to absorb the blast. Explosion behaviors such as initiating sensitivity, detonation, sympathetic detonation, and shock occurence of the ANFO explosives in place of dynamite and the slurry explosives were studied. The safety engineering standards for the manufacturing and application of explosives were studied to establish because accidents by tabacco fire are not still distinguished. Much data concerning early stage fire fighting, a large quantity of flooding and shock occurence from a assumption of ignition during machining in the propellants manufacturing plant, could be obtained. Basic studies were made to prevent pollution in blasting sites. Collected data are utilized for the safety administration after sufficient discussion. (4 figs, 2 tabs, 3 photos, 17 refs)

Periodic Safety Review of Nuclear Power Plants: Experience of Member States

International Nuclear Information System (INIS)

2010-04-01

Routine reviews of nuclear power plant operation (including modifications to hardware and procedures, operating experience, plant management and personnel competence) and special reviews following major events of safety significance are the primary means of safety verification. In addition, many Member States of the IAEA have initiated systematic safety reassessments, termed periodic safety reviews, of nuclear power plants, to assess the cumulative effects of plant ageing and plant modifications, operating experience, technical developments and siting aspects. The reviews include an assessment of plant design and operation against current safety standards and practices, and they have the objective of ensuring a high level of safety throughout the plant's operating lifetime. They are complementary to the routine and special safety reviews and do not replace them. Periodic safety reviews of nuclear power plants are considered an effective way to obtain an overall view of actual plant safety, and to determine reasonable and practical modifications that should be made in order to maintain a high level of safety. They can be used as a means of identifying time limiting features of the plant in order to determine nuclear power plant operation beyond the designed lifetime. The periodic safety review process can be used to support the decision making process for long term operation or licence renewal. Since 1994, the use of periodic safety reviews by Member States has substantially broadened and confirmed its benefits. Periodic safety review results have, for example, been used by some Member States to help provide a basis for continued operation beyond the current licence term, to communicate more effectively with stakeholders regarding nuclear power plant safety, and to help identify changes to plant operation that enhance safety. This IAEA-TECDOC is intended to assist Member States in the implementation of a periodic safety review. This publication complements the

SAS4A and FPIN2X validation for slow ramp TOP accidents: experiments TS-1 and TS-2

International Nuclear Information System (INIS)

Hill, D.J.

1986-01-01

The purpose of this paper is to present further results in the series of experimental analyses being performed using SAS4A and FPIN2X in order to provide a systematic validation of these codes. The two experiments discussed here, TS-1 and TS-2, were performed by Westinghouse Hanford/Hanford Engineering Development Laboratory (WHC/HEDL) in the Transient Reactor Test (TREAT) Facility. They were slow ramp transient overpowers (TOPs) of ∼ 5 cent/s equivalent Fast Flux Test Facility (FFTF) ramp rate, single-pin experiments in flowing sodium loops. The good agreement found here adds significantly to the experimental data base that provides the foundation for SAS4A and FPIN2X validation. It also shows that prefailure internal fuel motion is a phenomenon that has to be correctly accounted for, not only as a potential inherent safety mechanism, but also before any accurate prediction of fuel failure and subsequent fuel motion and the associated reactivity effects can be made. This is also true for metal-fueled pins. This capability is provided by PINACLE, which is being incorporated into SAS4A

Top production at hadron colliders

Indian Academy of Sciences (India)

New results on top quark production are presented from four hadron collider experiments: CDF and D0 at the Tevatron, and ATLAS and CMS at the LHC. Cross-sections for single top and top pair production are discussed, as well as results on the top–antitop production asymmetry and searches for new physics including ...

Top quark production at the LHC

CERN Document Server

Ferreira da Silva, Pedro

2016-01-01

Twenty years past its discovery, the top quark continues attracting great interest as experiments keep unveiling its properties. An overview of the latest measurements in the domain of top quark production, performed by the ATLAS and CMS experiments at the CERN LHC, is given. The latest measurements of top quark production rates via strong and electroweak processes are reported and compared to different perturbative QCD predictions. Fundamental properties, such as the mass or the couplings of the top quark, as well as re-interpretations seeking for beyond the standard model contributions in the top quark sector, are extracted from these measurements. In each case an attempt to highlight the first results and main prospects for the on-going Run 2 of the LHC is made.

Operational safety experience feedback by means of unusual event reports

International Nuclear Information System (INIS)

1996-07-01

Operational experience of nuclear power plants can be used to great advantage to enhance safety performance provided adequate measures are in place to collect and analyse it and to ensure that the conclusions drawn are acted upon. Feedback of operating experience is thus an extremely important tool to ensure high standards of safety in operational nuclear power plants and to improve the capability to prevent serious accidents and to learn from minor deviations and equipment failures - which can serve as early warnings -to prevent even minor events from occurring. Mechanisms also need to be developed to ensure that operating experience is shared both nationally as well as internationally. The operating experience feedback process needs to be fully and effectively established within the nuclear power plant, the utility, the regulatory organization as well as in other institutions such as technical support organizations and designers. The main purpose of this publication is to reflect the international consensus as to the general principles and practices in the operational safety experience feedback process. The examples of national practices for the whole or for particular parts of the process are given in annexes. The publication complements the IAEA Safety Series No.93 ''Systems for Reporting Unusual Events in Nuclear Power Plants'' (1989) and may also give a general guidance for Member States in fulfilling their obligations stipulated in the Nuclear Safety Convention. Figs, tabs

Operational safety experience feedback by means of unusual event reports

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-07-01

Operational experience of nuclear power plants can be used to great advantage to enhance safety performance provided adequate measures are in place to collect and analyse it and to ensure that the conclusions drawn are acted upon. Feedback of operating experience is thus an extremely important tool to ensure high standards of safety in operational nuclear power plants and to improve the capability to prevent serious accidents and to learn from minor deviations and equipment failures - which can serve as early warnings -to prevent even minor events from occurring. Mechanisms also need to be developed to ensure that operating experience is shared both nationally as well as internationally. The operating experience feedback process needs to be fully and effectively established within the nuclear power plant, the utility, the regulatory organization as well as in other institutions such as technical support organizations and designers. The main purpose of this publication is to reflect the international consensus as to the general principles and practices in the operational safety experience feedback process. The examples of national practices for the whole or for particular parts of the process are given in annexes. The publication complements the IAEA Safety Series No.93 ``Systems for Reporting Unusual Events in Nuclear Power Plants`` (1989) and may also give a general guidance for Member States in fulfilling their obligations stipulated in the Nuclear Safety Convention. Figs, tabs.

Top quark production at the Tevatron

Energy Technology Data Exchange (ETDEWEB)

Varnes, Erich W.; /Arizona U.

2010-09-01

The Fermilab Tevatron has, until recently, been the only accelerator with sufficient energy to produce top quarks. The CDF and D0 experiments have collected large samples of top quarks. We report on recent top quark production measurements of the single top and t{bar t} production cross sections, as well as studies of the t{bar t} invariant mass distribution and a search for highly boosted top quarks.

Economic/operational advantages of top drive installations

Energy Technology Data Exchange (ETDEWEB)

Brouse, M. [Tesco Drilling Technology, Houston, TX (United States)

1996-10-01

This article addresses specific types of drilling operations, procedures and techniques associated with top drive drilling that create selected and/or specific economic opportunities and justifications for using a rental top drive. Types of drilling operations and/or wells that commonly justify top drive drilling described here include: drilling through sloughing or swelling formations; drilling extended reach, high angle and/or horizontal wells; drilling underbalanced through normal and subnormal formations; and wells with high daily operating costs, time constraints, i.e., days vs. depth, and/or safety and environmental concerns. Top drives, of course, are not justified for every drilling operation. Here, the discussion indicates some situations where portable systems may be applicable.

Advanced Test Reactor (ATR) Facility 10CFR830 Safety Basis Related to Facility Experiments

International Nuclear Information System (INIS)

Tomberlin, T.A.

2002-01-01

The Idaho National Engineering and Environmental Laboratory (INEEL) Advanced Test Reactor (ATR), a DOE Category A reactor, was designed to provide an irradiation test environment for conducting a variety of experiments. The ATR Safety Analysis Report, determined by DOE to meet the requirements of 10 CFR 830, Subpart B, provides versatility in types of experiments that may be conducted. This paper addresses two general types of experiments in the ATR facility and how safety analyses for experiments are related to the ATR safety basis. One type of experiment is more routine and generally represents greater risks; therefore this type of experiment is addressed with more detail in the safety basis. This allows individual safety analyses for these experiments to be more routine and repetitive. The second type of experiment is less defined and is permitted under more general controls. Therefore, individual safety analyses for the second type of experiment tend to be more unique from experiment to experiment. Experiments are also discussed relative to ''major modifications'' and DOE-STD-1027-92. Application of the USQ process to ATR experiments is also discussed

Development of Large-Scale Spacecraft Fire Safety Experiments

DEFF Research Database (Denmark)

Ruff, Gary A.; Urban, David L.; Fernandez-Pello, A. Carlos

2013-01-01

exploration missions outside of low-earth orbit and accordingly, more complex in terms of operations, logistics, and safety. This will increase the challenge of ensuring a fire-safe environment for the crew throughout the mission. Based on our fundamental uncertainty of the behavior of fires in low...... of the spacecraft fire safety risk. The activity of this project is supported by an international topical team of fire experts from other space agencies who conduct research that is integrated into the overall experiment design. The large-scale space flight experiment will be conducted in an Orbital Sciences...

Top Quark Mass

CERN Document Server

Mulders, Martijn

2016-01-01

Ever since the discovery of the top quark at the Tevatron collider in 1995 the measurement of its mass has been a high priority. As one of the fundamental parameters of the Standard Theory of particle physics, the precise value of the top quark mass together with other inputs provides a test for the self-consistency of the theory, and has consequences for the stability of the Higgs field that permeates the Universe. In this review I will briefly summarize the experimental techniques used at the Tevatron and the LHC experiments throughout the years to measure the top quark mass with ever improving accuracy, and highlight the recent progress in combining all measurements in a single world average combination. As experimental measurements became more precise, the question of their theoretical interpretation has become important. The difficulty of relating the measured quantity to the fundamental top mass parameter has inspired alternative measurement methods that extract the top mass in complementary ways. I wil...

Access safety systems - New concepts from the LHC experience

International Nuclear Information System (INIS)

Ladzinski, T.; Delamare, C.; Luca, S. di; Hakulinen, T.; Hammouti, L.; Havart, F.; Juget, J.F.; Ninin, P.; Nunes, R.; Riesco, T.; Sanchez-Corral Mena, E.; Valentini, F.

2012-01-01

The LHC Access Safety System has introduced a number of new concepts into the domain of personnel protection at CERN. These can be grouped into several categories: organisational, architectural and concerning the end-user experience. By anchoring the project on the solid foundations of the IEC 61508/61511 methodology, the CERN team and its contractors managed to design, develop, test and commission on time a SIL3 safety system. The system uses a successful combination of the latest Siemens redundant safety programmable logic controllers with a traditional relay logic hard wired loop. The external envelope barriers used in the LHC include personnel and material access devices, which are interlocked door-booths introducing increased automation of individual access control, thus removing the strain from the operators. These devices ensure the inviolability of the controlled zones by users not holding the required credentials. To this end they are equipped with personnel presence detectors and the access control includes a state of the art bio-metry check. Building on the LHC experience, new projects targeting the refurbishment of the existing access safety infrastructure in the injector chain have started. This paper summarises the new concepts introduced in the LHC access control and safety systems, discusses the return of experience and outlines the main guiding principles for the renewal stage of the personnel protection systems in the LHC injector chain in a homogeneous manner. (authors)

Qinshan CANDU project open top construction method

International Nuclear Information System (INIS)

Petrunik, K.J.; Wittann, K.; Khan, A.; Ricciuti, R.; Ivanov, A.; Chen, S.

2003-01-01

The significant schedule reductions achieved on the Qinshan CANDU Project were due in large part to the incorporation of advanced construction technologies in project design and delivery. For the Qinshan Project, a number of key advantages were realized through the use of the 'Open Top' construction method. This paper discusses the Qinshan Phase III CANDU Project Open Top implementation method. The Open Top method allowed major equipment to be installed simply, via the use of a Very Heavy Lift (VHL) crane and permitted the use of large-scale modularization. The advantages of Open Top construction, such as simplified access, more flexible project scheduling, improved construction safety and quality, and reduced labours are presented. The large-scale modularization of the Reactor Building Dousing System and the Open Top installation method and advantages relative to traditional CANDU 6 construction practices are also presented. Finally, major improvements for future CANDU plant construction using the Open Top method are discussed. (author)

Evaluation of the influence of a postulated lubrication oil fire on safety related cables in the top shield platform of PFBR RCB by using FDS Code

International Nuclear Information System (INIS)

Mangarjuna Rao, P.; Jayasuriya, C.; Nashine, B.K.; Chellapandi, P.; Velusamy, K.

2010-01-01

Top deck of Prototype Fast Breeder Reactor (PFBR) primary system houses redundant safety related systems like Control and Safety Rod Drive Mechanisms (CSRDM), Diverse Safety Rod Drive Mechanism (DSRDM), subassembly outlet sodium temperature measurement system and central canal plug. These systems protrude out from the reactor through the Control Plug (CP), which is supported on the Top Shield (TS) of PFBR. Control and instrumentation signal cables and power cables of these safety related systems that are coming out from the CP are routed through Top Shield Platform (TSP, which is concentric with Reactor Vault (RV) at EL 34.1 m above the TS) to the peripheral local instrumentation control centers via the cable junction boxes supported on TS. Influence approach fire hazard analysis (FHA) has been carried out to evaluate the condition of redundant safety related cables under the scenario of a postulated oil fire in the TSP using Fire Dynamics Simulator code (FDS, Version 5). FDS is a computational fluid dynamics (CFD) based fire analysis code and it is developed by National Institute of Standards and Technology (NIST), USA. In this paper the details of the model developed and the results of the analysis carried out are discussed. In TSP, a postulated oil fire scenario with complete inventory of a primary sodium pump (PSP) lubrication oil leak (200 lt) has been considered at 30 m elevation on the TS. Computational model with the geometry of TSP and with other important structural components on TS like PSPs, intermediate heat exchangers (IHXs), large rotating plug (LRP), small rotating plug (SRP), CP and etc. has been developed along with a fire of 1800 kW/m 2 heat release rate in the vicinity of the PSP1. Numerical simulation has been carried out to evaluate this oil fire influence on the typical safety related cables routed at 34 m elevation. It has been found that the surface temperature of the cables that are routed directly above the fire only crosses the ignition

Measuring safety climate in a nuclear power plant - an experience sharing

International Nuclear Information System (INIS)

Vincy, M.U.; Varshney, Aloke; Khot, Pankaj

2016-01-01

In this paper the author discusses the experience gained in safety climate measurement of an Indian nuclear power plant. Safety performance is increasingly part of an organization's sustainable development. Nuclear power stations are falling under the category 'high reliability' industries in the world as far as work safety is concerned. Both the research and the practical experience continually point to two underlying factors that drive safety outcomes: the quality of an organisation's leadership and the resulting culture. After years of development in safety technology and safety management system in the industry, management of nuclear industry world over has come to recognize that safety culture has to be addressed if high standards of health and safety are to be maintained. Therefore, nuclear industries in India have been carrying out measurement of safety climate for more than ten years. The objectives of the study are to examine people's values, attitude, perception, competencies, and patterns of behaviour that determine the commitment to, and effectiveness of health and safety management in the industry based on a questionnaires survey and their analysis

Analysis of the ATLAS Cold Leg Top-Slot Break Experiment Using the MARS Code

Energy Technology Data Exchange (ETDEWEB)

Ha, T. W.; Jeong, J. J. [Pusan National University, Busan (Korea, Republic of)

2016-10-15

During a small-break loss of coolant accident (SBLOCA) or intermediate-break loss of coolant accident (IBLOCA) in a PWR, such as the APR1400, the steam volume in the reactor vessel upper plenum may continue to expand until the liquid phase in the horizontal intermediate legs is released, called loop seal clearing (LSC), due to the increase of the pressure in the upper plenum. A domestic standard problem (DSP) exercise using the ATLAS facility was promoted in order to transfer the database to domestic nuclear industries. For 4th DSP (DSP-04), the ATLAS cold leg top-slot break experiment was postulated. For the DSP-04, main concerns are to predict the LSC and LSR having a significantly effect on the behavior of the system under long term cooling. In this study, we simulated the ATLAS cold leg top-slot break experiment using the MARS code and the predicted LSC and LSR are compared to experimental results. The LTC-CL-04R was simulated using the MARS code. Most of the predicted results agree well with the experimental data. However, the timing of LSC and LSR is slightly different from each other and, thus, the behavior of the primary system is slightly different. The core heat up was not observed in the experiment and the calculation.

Electroweak production of the top quark in the Run II of the D0 experiment

Energy Technology Data Exchange (ETDEWEB)

Clement, Benoit [Louis Pasteur Univ., Strasbourg (France)

2006-04-28

The work exposed in this thesis deals with the search for electroweak production of top quark (single top) in proton-antiproton collisions at √s = 1.96 TeV. This production mode has not been observed yet. Analyzed data have been collected during the Run II of the D0 experiment at the Fermilab Tevatron collider. These data correspond to an integrated luminosity of 370 pb^-1. In the Standard Model, the decay of a top quark always produce a high momentum bottom quark. Therefore bottom quark jets identification plays a major role in this analysis. The large lifetime of b hadrons and the subsequent large impact parameters relative to the interaction vertex of charged particle tracks are used to tag bottom quark jets. Impact parameters of tracks attached to a jet are converted into the probability for the jet to originate from the primary vertex. This algorithm has a 45% tagging efficiency for a 0.5% mistag rate. Two processes (s and t channels) dominate single top production with slightly different final states. The searched signature consists in 2 to 4 jets with at least one bottom quark jet, one charged lepton (electron or muon) and missing energy accounting for a neutrino. This final state is background dominated and multivariate techniques are needed to separate the signal from the two main backgrounds: associated production of a W boson and jets and top quarks pair production. The achieved sensitivity is not enough to reach observation and we computed upper limits at the 95% confidence level at 5 pb (s-channel) and 4.3 pb (t-channel) on single top production cross-sections.

Search for leptoquarks and dark matter in final states with top quarks at the CMS experiment

Energy Technology Data Exchange (ETDEWEB)

Meyer, Mareike

2017-07-12

This thesis presents two searches for physics beyond the Standard Model (SM). A search for pair production of third-generation leptoquarks decaying into a top quark and a tau lepton using pp collision data recorded at a center-of-mass energy of 8 TeV with the CMS experiment is presented. The search is based on an event selection requiring an isolated muon or electron candidate, one hadronically decaying tau lepton candidate and at least three jets. The main reducible background originates from processes, where a jet is misidentified as a tau lepton candidate. A measurement of the tau lepton misidentification rate is performed in a sideband enriched in W+jets events. The transverse momentum distribution of the leading tau lepton candidate is used for the statistical interpretation of the result. No excess over the SM expectation is observed. Upper cross section limits on the pair production cross section of leptoquarks decaying into a top quark and a tau lepton are set. By combining the presented search with an analysis requiring same-sign muon-tau lepton-pairs, leptoquarks with masses below 685 GeV (695 GeV expected) are excluded at 95% C.L., assuming a branching ratio of 100% into a top quark and a tau lepton. The second analysis presented in this thesis is a search for Dark Matter (DM) produced in association with a top quark pair using data collected at a center-of-mass energy of 13 TeV by the CMS experiment. The analysis targets final states in which the top quarks receive large transverse momenta by recoiling against the DM particles. Therefore, the applied event selection allows for non-isolated leptons and uses top tagging techniques to identify merged top quark decays. The normalizations of the main background processes, t anti t+jets and W+jets, are determined in data using control regions enriched in the respective process. For the final statistical interpretation the spectra of the missing transverse momentum in two signal regions are studied. Data and

Search for leptoquarks and dark matter in final states with top quarks at the CMS experiment

International Nuclear Information System (INIS)

Meyer, Mareike

2017-01-01

This thesis presents two searches for physics beyond the Standard Model (SM). A search for pair production of third-generation leptoquarks decaying into a top quark and a tau lepton using pp collision data recorded at a center-of-mass energy of 8 TeV with the CMS experiment is presented. The search is based on an event selection requiring an isolated muon or electron candidate, one hadronically decaying tau lepton candidate and at least three jets. The main reducible background originates from processes, where a jet is misidentified as a tau lepton candidate. A measurement of the tau lepton misidentification rate is performed in a sideband enriched in W+jets events. The transverse momentum distribution of the leading tau lepton candidate is used for the statistical interpretation of the result. No excess over the SM expectation is observed. Upper cross section limits on the pair production cross section of leptoquarks decaying into a top quark and a tau lepton are set. By combining the presented search with an analysis requiring same-sign muon-tau lepton-pairs, leptoquarks with masses below 685 GeV (695 GeV expected) are excluded at 95% C.L., assuming a branching ratio of 100% into a top quark and a tau lepton. The second analysis presented in this thesis is a search for Dark Matter (DM) produced in association with a top quark pair using data collected at a center-of-mass energy of 13 TeV by the CMS experiment. The analysis targets final states in which the top quarks receive large transverse momenta by recoiling against the DM particles. Therefore, the applied event selection allows for non-isolated leptons and uses top tagging techniques to identify merged top quark decays. The normalizations of the main background processes, t anti t+jets and W+jets, are determined in data using control regions enriched in the respective process. For the final statistical interpretation the spectra of the missing transverse momentum in two signal regions are studied. Data and

Safety training for working youth: Methods used versus methods wanted.

Science.gov (United States)

Zierold, Kristina M

2016-04-07

Safety training is promoted as a tool to prevent workplace injury; however, little is known about the safety training experiences young workers get on-the-job. Furthermore, nothing is known about what methods they think would be the most helpful for learning about safe work practices. To compare safety training methods teens get on the job to those safety training methods teens think would be the best for learning workplace safety, focusing on age differences. A cross-sectional survey was administered to students in two large high schools in spring 2011. Seventy percent of working youth received safety training. The top training methods that youth reported getting at work were safety videos (42%), safety lectures (25%), and safety posters/signs (22%). In comparison to the safety training methods used, the top methods youth wanted included videos (54%), hands-on (47%), and on-the-job demonstrations (34%). This study demonstrated that there were differences in training methods that youth wanted by age; with older youth seemingly wanting more independent methods of training and younger teens wanting more involvement. Results indicate that youth want methods of safety training that are different from what they are getting on the job. The differences in methods wanted by age may aid in developing training programs appropriate for the developmental level of working youth.

Preliminary Safety Analysis Report for the Tokamak Physics Experiment

International Nuclear Information System (INIS)

Motloch, C.G.; Bonney, R.F.; Levine, J.D.; Masson, L.S.; Commander, J.C.

1995-04-01

This Preliminary Safety Analysis Report (PSAR), includes an indication of the magnitude of facility hazards, complexity of facility operations, and the stage of the facility life-cycle. It presents the results of safety analyses, safety assurance programs, identified vulnerabilities, compensatory measures, and, in general, the rationale describing why the Tokamak Physics Experiment (TPX) can be safely operated. It discusses application of the graded approach to the TPX safety analysis, including the basis for using Department of Energy (DOE) Order 5480.23 and DOE-STD-3009-94 in the development of the PSAR

Simulation of top quark production for the ATLAS experiment at sqrt(s) = 13 TeV

CERN Document Server

The ATLAS collaboration

2016-01-01

This note summarises the Monte Carlo simulation setup for the pair and single production of top quarks for the ATLAS experiment at the LHC for sqrt(s)=13 TeV. In addition to the settings available and recommended for analyses using the 2015 dataset, the anticipated setup for 2016 analysis is also discussed.

Top quark physics at the LHC

Directory of Open Access Journals (Sweden)

Jeong Kim Tae

2014-04-01

Full Text Available In 2011, an integrated luminosity of more than 5 fb−1 at 7 TeV has been delivered by the LHC. The measurement of the cross section in top quark pair production and in single top quark production, top quark mass, top quark properties and new physics searches in top quark decays have been performed at the CMS experiment with various integrated luminosities. An overview of the latest results of these measurements and searches by the time of ICFP 2012 conference will be presented.

Corporate financial decision-makers' perceptions of workplace safety.

Science.gov (United States)

Huang, Yueng-Hsiang; Leamon, Tom B; Courtney, Theodore K; Chen, Peter Y; DeArmond, Sarah

2007-07-01

This study, through a random national survey, explored how senior financial executives or managers (those who determined high-level budget, resource allocation, and corporate priorities) of medium-to-large companies perceive important workplace safety issues. The three top-rated safety priorities in resource allocation reported by the participants (overexertion, repetitive motion, and bodily reaction) were consistent with the top three perceived causes of workers' compensation losses. The greatest single safety concerns reported were overexertion, repetitive motion, highway accidents, falling on the same level and bodily reaction. A majority of participants believed that the indirect costs associated with workplace injury were higher than the direct costs. Our participants believed that money spent improving workplace safety would have significant returns. The perceived top benefits of an effective workplace safety program were increased productivity, reduced cost, retention, and increased satisfaction among employees. The perceived most important safety modification was safety training. The top reasons senior financial executives gave for believing their safety programs were better than those at other companies were that their companies paid more attention to and emphasized safety, they had better classes and training focused on safety, and they had teams/individuals focused specifically on safety.

Experience with a top-down versus bottom-up nuclear engineering educational paradigm

International Nuclear Information System (INIS)

Harms, A.A.

1991-01-01

Nuclear engineering courses are generally taught from a top-down pedagogical perspective; i.e., one begins with a body of knowledge drawn from advanced nuclear science, engineering, and experience and from this distills a selected part to match the intellectual capacity of the class. This pedagogical approach has evidently been most effect at the graduate level of instruction as evidenced by the ready entry of masters and doctoral students into the professions. A schematic depiction of this approach is suggested and is extended to the undergraduate level of nuclear engineering education

The Qualification Experiences for Safety-critical Software of POSAFE-Q

Energy Technology Data Exchange (ETDEWEB)

Kim, Jang Yeol; Son, Kwang Seop; Cheon, Se Woo; Lee, Jang Soo; Kwon, Kee Choon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2009-05-15

Programmable Logic Controllers (PLC) have been applied to the Reactor Protection System (RPS) and the Engineered Safety Feature (ESF)-Component Control System (CCS) as the major safety system components of nuclear power plants. This paper describes experiences on the qualification of the safety-critical software including the pCOS kernel and system tasks related to a safety-grade PLC, i.e. the works done for the Software Verification and Validation, Software Safety Analysis, Software Quality Assurance, and Software Configuration Management etc.

Safety requirements and safety experience of nuclear facilities in the Federal Republic of Germany

International Nuclear Information System (INIS)

Schnurer, H.L.

1977-01-01

Peaceful use of nuclear energy within the F.R.G. is rapidly growing. The Energy Programme of the Federal Government forecasts a capacity of up to 50.000 MW in 1985. Whereas most of this capacity will be of the LWR-Type, other activities are related to LMFBR - and HTGR - development, nuclear ships, and facilities of the nuclear fuel cycle. Safety of nuclear energy is the pacemaker for the realization of nuclear programmes and projects. Due to a very high population - and industrialisation density, safety has the priority before economical aspects. Safety requirements are therefore extremely stringent, which will be shown for the legal, the technical as well as for the organizational area. They apply for each nuclear facility, its site and the nuclear energy system as a whole. Regulatory procedures differ from many other countries, assigning executive power to state authorities, which are supervised by the Federal Government. Another particularity of the regulatory process is the large scope of involvement of independent experts within the licensing procedures. The developement of national safety requirements in different countries generates a necessity to collaborate and harmonize safety and radiation protection measures, at least for facilities in border areas, to adopt international standards and to assist nuclear developing countries. However, different nationally, regional or local situations might raise problems. Safety experience with nuclear facilities can be concluded from the positive construction and operation experience, including also a few accidents and incidents and the conclusions, which have been drawn for the respective factilities and others of similar design. Another tool for safety assessments will be risk analyses, which are under development by German experts. Final, a scope of future problems and developments shows, that safety of nuclear installations - which has reached a high performance - nevertheless imposes further tasks to be solved

Safety aspects and operating experience of LWR plants in Japan

International Nuclear Information System (INIS)

Aoki, S.; Yoshioka, T.; Toyota, M.; Hinoki, M.

1977-01-01

To develop nuclear power generation for the future, it is necessary to put further emphasis on safety assurance and to endeavour to devise measures to improve plant availability, based on the careful analysis of causes that reduce plant availability. The paper discusses the results of studies on the following items from such viewpoints: (1) Safety and operating experience of LWR nuclear power plants in Japan: operating experience with LWRs; improvements in LWR design during the past ten years; analysis of the factors affecting plant availability; (2) Assurance of safety and measures to increase availability: measures for safety and environmental protection; measures to reduce radiation exposure of employees; appropriateness of maintenance and inspection work; measures to increase plant availability; measures to improve reliability of equipment and components; (3) Future technical problems. (author)

Measurements of Top Properties at the Tevatron

International Nuclear Information System (INIS)

Husemann, Ulrich; Yale U.

2007-01-01

The large data samples of thousands of top events collected at the Tevatron experiments CDF and D(O) allow for a variety of measurements to analyze the properties of the top quark. Guided by the question ''Is the top quark observed at the Tevatron really the top quark of the standard model,'' we present Tevatron analyses studying the top production mechanism including resonant t(bar t) production, the V -A structure of the t → Wb decay vertex, the charge of the top quark, and single-top production via flavor-changing neutral currents

Experience of safety and performance improvement for fuel handling equipment

International Nuclear Information System (INIS)

Gyoon Chang, Sang; Hee Lee, Dae

2014-01-01

The purpose of this study is to provide experience of safety and performance improvement of fuel handling equipment for nuclear power plants in Korea. The fuel handling equipment, which is used as an important part of critical processes during the refueling outage, has been improved to enhance safety and to optimize fuel handling procedures. Results of data measured during the fuel reloading are incorporated into design changes. The safety and performance improvement for fuel handling equipment could be achieved by simply modifying the components and improving the interlock system. The experience provided in this study can be useful lessons for further improvement of the fuel handling equipment. (authors)

Signatures of top flavour-changing dark matter

International Nuclear Information System (INIS)

Hondt, Jorgen d'; Mariotti, Alberto; Moortgat, Seth; Tziveloglou, Pantelis

2015-12-01

We develop the phenomenology of scenarios in which a dark matter candidate interacts with a top quark through flavour-changing couplings, employing a simplified dark matter model with an s-channel vector-like mediator. We study in detail the top-charm flavour-changing interaction, by investigating the single top plus large missing energy signature at the LHC as well as constraints from the relic density and direct and indirect dark matter detection experiments. We present strategies to distinguish between the top-charm and top-up flavour-changing models by taking advantage of the lepton charge asymmetry as well as by using charm-tagging techniques on an extra jet. We also show the complementarity between the LHC and canonical dark matter experiments in exploring the viable parameter space of the models.

Signatures of top flavour-changing dark matter

Energy Technology Data Exchange (ETDEWEB)

Hondt, Jorgen d' ; Mariotti, Alberto; Moortgat, Seth; Tziveloglou, Pantelis [Vrieje Univ. Brussel (Belgium). Theoretische Natuurkunde and IIHE/ELEM; Mawatari, Kentarou [Vrieje Univ. Brussel (Belgium). Theoretische Natuurkunde and IIHE/ELEM; Grenoble-Alpes Univ., CNRS/IN2P3 (France). Lab. de Physique Subatomique et de Cosmologie; Onsem, Gerrit van [Vrieje Univ. Brussel (Belgium). Theoretische Natuurkunde and IIHE/ELEM; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2015-12-15

We develop the phenomenology of scenarios in which a dark matter candidate interacts with a top quark through flavour-changing couplings, employing a simplified dark matter model with an s-channel vector-like mediator. We study in detail the top-charm flavour-changing interaction, by investigating the single top plus large missing energy signature at the LHC as well as constraints from the relic density and direct and indirect dark matter detection experiments. We present strategies to distinguish between the top-charm and top-up flavour-changing models by taking advantage of the lepton charge asymmetry as well as by using charm-tagging techniques on an extra jet. We also show the complementarity between the LHC and canonical dark matter experiments in exploring the viable parameter space of the models.

Feedback of safety - related operational experience: Lessons learned

Energy Technology Data Exchange (ETDEWEB)

Elias, D [Commonwealth Edison Co. (United States)

1997-09-01

The presentation considers the following aspects of feedback of safety-related operational experience: lessons learned program, objectives, personnel characteristics; three types of documents for transmitting lessons learned issues.

Feedback of safety - related operational experience: Lessons learned

International Nuclear Information System (INIS)

Elias, D.

1997-01-01

The presentation considers the following aspects of feedback of safety-related operational experience: lessons learned program, objectives, personnel characteristics; three types of documents for transmitting lessons learned issues

SAFETY FIRST

Institute of Scientific and Technical Information of China (English)

2007-01-01

Ensuring safety while peacefully utilizing nuclear energy is a top priority for China A fter a recent earthquake in Japan caused radioactive leaks at a nuclear power plant in Tokyo, the safety of nuclear energy has again aroused public attention.

ATLAS Cold Leg Top Slot Break Analysis using RELAP5

Energy Technology Data Exchange (ETDEWEB)

Sung, Haejung; Lee, Sang Ik; Park, Ju-Hyun; Choi, Tong-Soo [KEPCO NF, Daejeon (Korea, Republic of)

2016-10-15

U.S. Nuclear Regulatory Commission (US-NRC) has been reviewing the design certification application for APR1400 submitted by Korea Electric Power Corporation (KEPCO). The main concern about cold leg top slot break is that cladding temperature might be increased by core uncover due to four loop seal reformation following flooding of safety injection water. An integral effect test for cold leg top slot break was performed by KAERI (Korea Atomic Energy Research Institute) using ATLAS (Advanced Thermal-Hydraulic Test Loop for Accident Simulation), which is a scaled down experimental facility for APR1400. In this study, RELAP5/MOD3.3/Patch04 is assessed by experimental result of ATLAS cold leg top slot break. Also, thermal hydraulic phenomena by four loop seals reformation is observed by RELAP5 result. The RELAP5/MOD3.3/Patch04 is assessed by the experimental result of ATLAS cold leg top slot break. The top slot break is described by offtake model, and the mass flow rate is fairly well estimated. The RELAP5 well predicts the correlation between general trend and four loop seal reformation. The pressure of the core region and the cladding temperature tends to increase during four loop seal reformation due to steam path blockage on four loop seals. It is presumed that the code cannot estimate two phase phenomena by loop seal clearing as same as experiments. In terms of cladding temperature, loop seal reformation due to loop seal elevation of APR1400 does not need to be the issue, since the void fraction at the active top core is maintained over 0.4.

Summary of the Session on the Top Quark

Energy Technology Data Exchange (ETDEWEB)

Chudoba, Jiri [Prague, Inst. Phys.; Butler, Joel [Fermilab; Soustruznik, Karel [Charles U.

2012-01-01

The CDF and DØ experiments at the Fermilab Tevatron and the ATLAS and CMS experiments at the Large Hadron Collider (LHC) showed recent results on the production and properties of the top quark. CP violation in top decays was discussed as an example of the kind of new studies that will become possible with the very large samples of top decays that will be produced at the LHC.

Critical experiments facility and criticality safety programs at JAERI

International Nuclear Information System (INIS)

Kobayashi, Iwao; Tachimori, Shoichi; Takeshita, Isao; Suzaki, Takenori; Miyoshi, Yoshinori; Nomura, Yasushi

1985-10-01

The nuclear criticality safety is becoming a key point in Japan in the safety considerations for nuclear installations outside reactors such as spent fuel reprocessing facilities, plutonium fuel fabrication facilities, large scale hot alboratories, and so on. Especially a large scale spent fuel reprocessing facility is being designed and would be constructed in near future, therefore extensive experimental studies are needed for compilation of our own technical standards and also for verification of safety in a potential criticality accident to obtain public acceptance. Japan Atomic Energy Research Institute is proceeding a construction program of a new criticality safety experimental facility where criticality data can be obtained for such solution fuels as mainly handled in a reprocessing facility and also chemical process experiments can be performed to investigate abnormal phenomena, e.g. plutonium behavior in solvent extraction process by using pulsed colums. In FY 1985 detail design of the facility will be completed and licensing review by the government would start in FY 1986. Experiments would start in FY 1990. Research subjects and main specifications of the facility are described. (author)

Single top quark production with CMS

Directory of Open Access Journals (Sweden)

Piccolo Davide

2013-11-01

Full Text Available Measurements of single top quark production performed using the CMS experiment [1] data collected in 2011 at centre-of-mass energies of 7 TeV and in 2012 at 8 TeV, are presented. The cross sections for the electroweak production of single top quarks in the t-channel and in association with W-bosons is measured and the results are used to place constraints on the CKM matrix element Vtb. Measurements of top quark properties in single top quark production are also presented. The results include the measurement of the charge ratio in the single top t-channel.

Top quark mass measurement

International Nuclear Information System (INIS)

Maki, Tuula; Helsinki Inst. of Phys.; Helsinki U. of Tech.

2008-01-01

The top quark is the heaviest elementary particle. Its mass is one of the fundamental parameters of the standard model of particle physics, and an important input to precision electroweak tests. This thesis describes three measurements of the top-quark mass in the dilepton decay channel. The dilepton events have two neutrinos in the final state; neutrinos are weakly interacting particles that cannot be detected with a multipurpose experiment. Therefore, the signal of dilepton events consists of a large amount of missing energy and momentum carried off by the neutrinos. The top-quark mass is reconstructed for each event by assuming an additional constraint from a top mass independent distribution. Template distributions are constructed from simulated samples of signal and background events, and parameterized to form continuous probability density functions. The final top-quark mass is derived using a likelihood fit to compare the reconstructed top mass distribution from data to the parameterized templates. One of the analyses uses a novel technique to add top mass information from the observed number of events by including a cross-section-constraint in the likelihood function. All measurements use data samples collected by the CDF II detector

Use of top tethers with forward-facing child restraints: observations and driver interviews.

Science.gov (United States)

Eichelberger, Angela H; Decina, Lawrence E; Jermakian, Jessica S; McCartt, Anne T

2014-02-01

Despite the safety benefits, many parents do not use top tethers with forward-facing child restraints. Detailed information was collected about why parents are not using tethers. The sample included 479 drivers who had forward-facing child restraints installed in passenger vehicles equipped with tether anchors. The survey was conducted primarily at shopping centers, recreation facilities, child care facilities, car seat check events, and health care facilities in mostly suburban areas surrounding Philadelphia, Washington, DC, Fredericksburg (VA), and Seattle. Drivers were surveyed about their knowledge and use of tethers and experience with child restraints. Tether use was observed to verify whether tethers were being used correctly. Fifty-six percent of forward-facing child restraints were installed with the tether; 39% were installed with the tether used correctly. The tether was used with 71% of LATCH lower anchor installations and 33% of seat belt installations. Drivers who installed child restraints without tethers most often said they did not know about the tether or how to use it. Although the tether use rate was slightly higher in the current research than in previous studies, many parents and caregivers still use forward-facing child restraints without attaching the tether. Because the main problem is lack of awareness of the tether or how to use it, public education should focus specifically on the safety benefits of tethers and how to use them. Information about why caregivers fail to use top tethers is potentially useful to child restraint manufacturers, child passenger safety technicians, and others who work with parents to improve motor vehicle safety. Copyright © 2013 Elsevier Ltd and National Safety Council. All rights reserved.

Return on experience. Building tomorrow's safety rules

International Nuclear Information System (INIS)

Anon.

2013-01-01

Based on some experiments and witnesses, this set of articles outlines the importance of the return on experience in the evolution of process for improving the safety of nuclear installations. As an example, an article notably addresses the failures of Diesel engines which are used as spare generators in nuclear power stations: failures have been analysed and attributed to bearings, and more specifically to the degradation of their surface, and a third generation of bearings has been designed and produced. An article outlines that different industrials belonging to the nuclear sector as well as to other sectors share their returns on experience

Measurement of the top quark mass using dilepton events and a neutrino weighting algorithm with the DOe experiment at the Tevatron (Run II)

Energy Technology Data Exchange (ETDEWEB)

Meyer, J.

2007-07-01

Several measurements of the top quark mass in the dilepton final states with the DOe experiment are presented. The theoretical and experimental properties of the top quark are described together with a brief introduction of the Standard Model of particle physics and the physics of hadron collisions. An overview over the experimental setup is given. The Tevatron at Fermilab is presently the highest-energy hadron collider in the world with a center-of-mass energy of 1.96 TeV. There are two main experiments called CDF and DOe, A description of the components of the multipurpose DOe detector is given. The reconstruction of simulated events and data events is explained and the criteria for the identification of electrons, muons, jets, and missing transverse energy is given. The kinematics in the dilepton final state is underconstraint. Therefore, the top quark mass is extracted by the so-called Neutrino Weighting method. This method is introduced and several different approaches are described, compared, and enhanced. Results for the international summer conferences 2006 and winter 2007 are presented. The top quark mass measurement for the combination of all three dilepton channels with a dataset of 1.05 1/fb yields: mtop=172.5{+-}5.5 (stat.) {+-} 5.8 (syst.) GeV. This result is presently the most precise top quark mass measurement of the DOe experiment in the dilepton chann el. It entered the top quark mass wold average from March 2007. (orig.)

submitter Direct measurement of the top quark decay width in the muon + jets channel using the CMS experiment at the LHC

CERN Document Server

Moreels, Lieselotte; D'Hondt, Jorgen

This thesis investigates the decay properties of the top quark. In the SM the top quark decays almost exclusively into a W boson and a b quark. The probability for this process to happen is reflected in the top quark decay width, which is predicted to have a value around 1.33 GeV. If the top quark is able to decay into other particles as well, as is possible in several extensions of the SM, the top quark decay width will be larger than the SM prediction. This is investigated by performing a direct measurement of the top quark decay width using proton collisions produced by the Large Hadron Collider at a centre-of-mass energy of 13 TeV. The data were recorded by the CMS experiment in 2016 and correspond to an integrated luminosity of 35.9 fb−1 . At first, a concise overview of the standard model is presented in Chapter 1. The production and decay of the top quark is described in more detail and the current status of the top quark mass and decay width measurements is given. Top quarks are typically studied by...

Safety climate mapping in a nuclear power plant - an experience sharing

International Nuclear Information System (INIS)

Vincy, M.U.; Varshney, Aloke; Khot, Pankaj

2016-01-01

In this paper the author discusses the experience gained in safety climate measurement of an Indian nuclear power plant. Safety performance is increasingly part of an organisation's sustainable development. Nuclear power stations are falling under the category 'high reliability' industries in the world as far as work safety is concerned. Both the research and the practical experience continually point to two underlying factors that drive safety outcomes: the quality of an organisation's leadership and the resulting culture. After years of development in safety technology and safety management system in the industry, management of nuclear industry world over has come to recognize that safety culture has to be addressed if high standards of health and safety are to be maintained. Therefore, nuclear industries in India have been carrying out measurement of safety climate for more than ten years. The objectives of the study are to examine people's values, attitude, perception, competencies, and patterns of behaviour that determine the commitment to, and effectiveness of health and safety management in the industry based on questionnaires survey and their analysis. A questionnaire, consists of 66 statements with 11 attributes, was designed to seek the views of managers, supervisors and front line workers on key aspects of the safety culture. Each of the discrete group was also classified according to their role in the organisation

Top event prevention analysis: A deterministic use of PRA

International Nuclear Information System (INIS)

Worrell, R.B.; Blanchard, D.P.

1996-01-01

This paper describes the application of Top Event Prevention Analysis. The analysis finds prevention sets which are combinations of basic events that can prevent the occurrence of a fault tree top event such as core damage. The problem analyzed in this application is that of choosing a subset of Motor-Operated Valves (MOVs) for testing under the Generic Letter 89-10 program such that the desired level of safety is achieved while providing economic relief from the burden of testing all safety-related valves. A brief summary of the method is given, and the process used to produce a core damage expression from Level 1 PRA models for a PWR is described. The analysis provides an alternative to the use of importance measures for finding the important combination of events in a core damage expression. This application of Top Event Prevention Analysis to the MOV problem was achieve with currently available software

Search for heavy resonance in the top-antitop invariant mass spectrum at the ATLAS experiment in the LHC

International Nuclear Information System (INIS)

Dechenaux, B.

2013-01-01

This report presents the analysis conducted with the ATLAS experiment at the LHC and searching for resonant production of new particles decaying into a pair of top quarks. Top quark reconstruction is mainly build upon the notion of hadronic jets, whose identification and reconstruction is a crucial issue for any measure trying to sign top quark decays from proton-proton collisions processes. After a general description of the theoretical and experimental features of jet reconstruction in the ATLAS detector, we present a first attempt to validate the local hadronic calibration method, which aim at correcting the measurement of these objects from inaccuracies caused by detector effects. In the second part, we present the analysis conducted on 14 fb -1 of proton-proton collision data at √(s)=8 TeV collected during the year 2012 and searching for resonant creation of new heavy particles in top-anti-top invariant mass spectrum. For heavy particles, the quarks produced in the decay of the latter have a high impulsion with respect to their mass and those top quark decays often results in a so called 'boosted topology', where the hadronic-decaying top quark is often reconstructed as a single jet of large radius parameter. In this context, we present a preliminary study to reconstruct and identify as precisely as possible this type of boosted topologies, based on the study of jet substructure. (author)

CP Violation in Single Top Quark Production

Energy Technology Data Exchange (ETDEWEB)

Geng, Weigang [Michigan State Univ., East Lansing, MI (United States)

2012-01-01

We present a search for CP violation in single top quark production with the DØ experiment at the Tevatron proton-antiproton collider. CP violation in the top electroweak interaction results in different single top quark production cross sections for top and antitop quarks. We perform the search in the single top quark final state using 5.4 fb^-1 of data, in the s-channel, t-channel, and for both combined. At this time, we do not see an observable CP asymmetry.

First experience with the new .cern Top Level Domain

Science.gov (United States)

Alvarez, E.; Malo de Molina, M.; Salwerowicz, M.; Silva De Sousa, B.; Smith, T.; Wagner, A.

2017-10-01

In October 2015, CERN’s core website has been moved to a new address, http://home.cern, marking the launch of the brand new top-level domain .cern. In combination with a formal governance and registration policy, the IT infrastructure needed to be extended to accommodate the hosting of Web sites in this new top level domain. We will present the technical implementation in the framework of the CERN Web Services that allows to provide virtual hosting, a reverse proxy solution and that also includes the provisioning of SSL server certificates for secure communications.

Suitable footwear for enhanced safety

CERN Document Server

2004-01-01

Safety shoes are the theme of a new safety campaign. Always remember that accidents can happen - even to your feet! When entering hazardous areas such as underground halls, work sites, experiment assembly sites, workshops etc., sandals, ordinary shoes or similar light footwear should not be worn. Whatever the risks to which you may be exposed, always think safety and wear suitable footwear, i.e. safety shoes, which have non-slip soles and steel reinforcements to protect your feet from being crushed, fractured or pierced. Is it serious, Doctor? "Some traumas resulting from foot-related accidents - open fractures for instance - can be quite serious," explains CERN Works Doctor Véronique Fassnacht. "But the most common injuries are sprained ankles sustained during simple falls caused by differences in floor-levels (e.g. false floors). Fractures, bruising, surface wounds or deep wounds caused by objects falling onto the top of the foot are also quite common." ...

Experience gained in enhancing operational safety at ComEd's nuclear power plants

International Nuclear Information System (INIS)

Elias, D.

1997-01-01

The following aspects of experience gained in enhancing operational safety at Comed's nuclear power plants are discussed: nuclear safety policy; centralization/decentralization; typical nuclear operating organization; safety review boards; human performance enhancement; elements of effective nuclear oversight

Benchmarking criticality safety calculations with subcritical experiments

International Nuclear Information System (INIS)

Mihalczo, J.T.

1984-06-01

Calculation of the neutron multiplication factor at delayed criticality may be necessary for benchmarking calculations but it may not be sufficient. The use of subcritical experiments to benchmark criticality safety calculations could result in substantial savings in fuel material costs for experiments. In some cases subcritical configurations could be used to benchmark calculations where sufficient fuel to achieve delayed criticality is not available. By performing a variety of measurements with subcritical configurations, much detailed information can be obtained which can be compared directly with calculations. This paper discusses several measurements that can be performed with subcritical assemblies and presents examples that include comparisons between calculation and experiment where possible. Where not, examples from critical experiments have been used but the measurement methods could also be used for subcritical experiments

MATURATION PYRAMID OF OCCUPATIONAL HEALTH AND SAFETY

OpenAIRE

Perçin, Fatih; Haydan, Eren

2017-01-01

Occupational Health and Safety System (OHS) isimportant for governments, employers and workers. Recently, OHS program hasdeveloped day by day and tried to secure working environment. For this purpose,it is necessary that the written job security rulesin the workplace should be internalized by employees, and employers, andgovernment system. Workers can comply from the top to the bottom oforganization and contribute to development of rules through their own personalknowledge, experience, and in...

Operating experience feedback from safety significant events at research reactors

Energy Technology Data Exchange (ETDEWEB)

Shokr, A.M. [Atomic Energy Authority, Abouzabal (Egypt). Egypt Second Research Reactor; Rao, D. [Bhabha Atomic Research Centre, Mumbai (India)

2015-05-15

Operating experience feedback is an effective mechanism to provide lessons learned from the events and the associated corrective actions to prevent recurrence of events, resulting in improving safety in the nuclear installations. This paper analyzes the events of safety significance that have been occurred at research reactors and discusses the root causes and lessons learned from these events. Insights from literature on events at research reactors and feedback from events at nuclear power plants that are relevant to research reactors are also presented along with discussions. The results of the analysis showed the importance of communication of safety information and exchange of operating experience are vital to prevent reoccurrences of events. The analysis showed also the need for continued attention to human factors and training of operating personnel, and the need for establishing systematic ageing management programmes of reactor facilities, and programmes for safety management of handling of nuclear fuel, core components, and experimental devices.

Operating experience feedback from safety significant events at research reactors

International Nuclear Information System (INIS)

Shokr, A.M.

2015-01-01

Operating experience feedback is an effective mechanism to provide lessons learned from the events and the associated corrective actions to prevent recurrence of events, resulting in improving safety in the nuclear installations. This paper analyzes the events of safety significance that have been occurred at research reactors and discusses the root causes and lessons learned from these events. Insights from literature on events at research reactors and feedback from events at nuclear power plants that are relevant to research reactors are also presented along with discussions. The results of the analysis showed the importance of communication of safety information and exchange of operating experience are vital to prevent reoccurrences of events. The analysis showed also the need for continued attention to human factors and training of operating personnel, and the need for establishing systematic ageing management programmes of reactor facilities, and programmes for safety management of handling of nuclear fuel, core components, and experimental devices.

Study of the electronic trigger system for HL-LHC project and search for new physics in top anti-top invariant mass spectrum with CMS experiment at LHC

International Nuclear Information System (INIS)

Beaupere, N.

2012-01-01

This manuscript describes my thesis work within the CMS experiment of the LHC collider. It presents both subjects on which I worked: a detector subject and a data analysis subject. The first subject, detector, is situated within the framework of the HL-LHC project which plans an increase by a factor five of the instantaneous luminosity. Such an increase and the preservation of the high level trigger (HLT) system, generate new constraints on the CMS detector. This is particularly true for the electronic trigger (L1) system. The CMS collaboration intends to implant this within tracker detector. Two methods are proposed: the stub modules method and the associative memory method. However, associative memory method requires a clever pre-selection of electric signals to be usable. The cluster width method is jointly proposed by Fabrizio Palla's team (Pisa) and by Didier Contardo's team (IPNL) to pre-select electric signals. The optimization of this method, in particular geometrical parameters of modules and thresholds applied for the electric signals pre-selection, is the result of my own work. It is detailed throughout the part III of this manuscript. The second subject concerns the analysis of data collected by CMS during 2011. This analysis has for objective to look for new particles in the spectre of anti-top top invariant mass. Due to its big mass, close to the electroweak symmetry breaking energy, the top quark plays an important role in numerous extensions of the Standard Model. The observation of narrow resonances in the spectre could be the sign of new particles. The analysis is subdivided into three parts, the selection of top anti-top events, the reconstruction of top anti-top invariant mass and a statistical study to quantify the presence of new physics. The results of this work are limits on the cross-section production of new particles. They are presented in the part IV of this manuscript. (author)

"Nursing Students Assaulted": Considering Student Safety in Community-Focused Experiences.

Science.gov (United States)

Maneval, Rhonda E; Kurz, Jane

2016-01-01

Community nursing experiences for undergraduate students have progressed beyond community-based home visits to a wide array of community-focused experiences in neighborhood-based centers, clinics, shelters, and schools. Our Bachelor of Science in Nursing program chose to use sites situated within neighborhoods close to campus in order to promote student and faculty engagement in the local community. These neighborhood sites provide opportunities for students to deliver nursing services to underserved and vulnerable populations experiencing poverty and health disparities. Some of these neighborhoods are designated as high crime areas that may potentially increase the risk of harm to students and faculty. There is a need to acknowledge the risk to personal safety and to proactively create policies and guidelines to reduce potential harm to students engaged in community-focused experiences. When a group of baccalaureate nursing students was assaulted while walking to a neighborhood clinic, the faculty was challenged as how to respond given the lack of policies and guidelines. Through our experience, we share strategies to promote personal safety for students and recommend transparency by administrators regarding potential safety risks to students engaged in community-focused fieldwork activities. Copyright © 2016 Elsevier Inc. All rights reserved.

Semi- and dileptonic top pair decays at the ATLAS experiment

Energy Technology Data Exchange (ETDEWEB)

Mameghani, Raphael

2008-05-15

The Large Hadron Collider, starting in 2008, will be a 'top factory' as top-antitop (t anti t) pairs will be produced with a cross section of about 830 pb at an instantaneous luminosity of 10{sup 33}cm{sup -2}s{sup -1} during the first year. With about 30% probability top pairs decay semileptonically into a final state with four jets, lepton (electron or muon) and respective neutrino. For another 5% of the t anti t events a dileptonic decay is expected. Here the final state signature is composed of two jets, two leptons and two neutrinos. In this thesis the precision for a t anti t cross section measurement at the ATLAS experiment in the semileptonic and dileptonic channels with cut based analyses, applicable to the first data, was estimated. The analysis of the semileptonic decay focused especially on the study of background from QCD events either with leptons from semileptonic hadron decays or from hadrons falsely identified as electrons by the calorimeter. For the first 10 fb{sup -1} and assuming a fake electron probability of 10{sup -3} a precision for the cross section times the branching ratio of {delta}({sigma}{sub t} {sub anti} {sub t}.B(t anti t{yields}bq anti q' anti bl anti {nu}))={+-}0.5(stat){+-}30.4(syst){+-}24.0(lumi) pb has been estimated, corresponding to a relative precision of 16% for the theoretically predicted cross section times branching ratio of about 240 pb. The analysis in the dileptonic channel achieves a precision of {delta}({sigma}{sub t} {sub anti} {sub t}.B(t anti t{yields}b anti l{nu} anti bl anti {nu}))={+-}0.2(stat){+-}2.5(syst){+-}2.6(lumi) pb which translates into a relative error of 10% for the cross section times branching ratio of around 38 pb. The errors for both the semileptonic and the dileptonic channel are expected to improve as progress is made on the luminosity determination and the knowledge of the backgrounds from comparisons with measured data. A measurement of the cross-section ratio between the

Semi- and dileptonic top pair decays at the ATLAS experiment

International Nuclear Information System (INIS)

Mameghani, Raphael

2008-05-01

The Large Hadron Collider, starting in 2008, will be a ''top factory'' as top-antitop (t anti t) pairs will be produced with a cross section of about 830 pb at an instantaneous luminosity of 10 33 cm -2 s -1 during the first year. With about 30% probability top pairs decay semileptonically into a final state with four jets, lepton (electron or muon) and respective neutrino. For another 5% of the t anti t events a dileptonic decay is expected. Here the final state signature is composed of two jets, two leptons and two neutrinos. In this thesis the precision for a t anti t cross section measurement at the ATLAS experiment in the semileptonic and dileptonic channels with cut based analyses, applicable to the first data, was estimated. The analysis of the semileptonic decay focused especially on the study of background from QCD events either with leptons from semileptonic hadron decays or from hadrons falsely identified as electrons by the calorimeter. For the first 10 fb -1 and assuming a fake electron probability of 10 -3 a precision for the cross section times the branching ratio of Δ(σ t anti t .B(t anti t→bq anti q' anti bl anti ν))=±0.5(stat)±30.4(syst)±24.0(lumi) pb has been estimated, corresponding to a relative precision of 16% for the theoretically predicted cross section times branching ratio of about 240 pb. The analysis in the dileptonic channel achieves a precision of Δ(σ t anti t .B(t anti t→b anti lν anti bl anti ν))=±0.2(stat)±2.5(syst)±2.6(lumi) pb which translates into a relative error of 10% for the cross section times branching ratio of around 38 pb. The errors for both the semileptonic and the dileptonic channel are expected to improve as progress is made on the luminosity determination and the knowledge of the backgrounds from comparisons with measured data. A measurement of the cross-section ratio between the dileptonic and semileptonic channel is sensitive to scenarios of new phenomena with competitive top quark decay modes

Semi- and dileptonic top pair decays at the ATLAS experiment

Energy Technology Data Exchange (ETDEWEB)

Mameghani, Raphael

2008-05-15

The Large Hadron Collider, starting in 2008, will be a 'top factory' as top-antitop (t anti t) pairs will be produced with a cross section of about 830 pb at an instantaneous luminosity of 10{sup 33}cm{sup -2}s{sup -1} during the first year. With about 30% probability top pairs decay semileptonically into a final state with four jets, lepton (electron or muon) and respective neutrino. For another 5% of the t anti t events a dileptonic decay is expected. Here the final state signature is composed of two jets, two leptons and two neutrinos. In this thesis the precision for a t anti t cross section measurement at the ATLAS experiment in the semileptonic and dileptonic channels with cut based analyses, applicable to the first data, was estimated. The analysis of the semileptonic decay focused especially on the study of background from QCD events either with leptons from semileptonic hadron decays or from hadrons falsely identified as electrons by the calorimeter. For the first 10 fb{sup -1} and assuming a fake electron probability of 10{sup -3} a precision for the cross section times the branching ratio of {delta}({sigma}{sub t} {sub anti} {sub t}.B(t anti t{yields}bq anti q' anti bl anti {nu}))={+-}0.5(stat){+-}30.4(syst){+-}24.0(lumi) pb has been estimated, corresponding to a relative precision of 16% for the theoretically predicted cross section times branching ratio of about 240 pb. The analysis in the dileptonic channel achieves a precision of {delta}({sigma}{sub t} {sub anti} {sub t}.B(t anti t{yields}b anti l{nu} anti bl anti {nu}))={+-}0.2(stat){+-}2.5(syst){+-}2.6(lumi) pb which translates into a relative error of 10% for the cross section times branching ratio of around 38 pb. The errors for both the semileptonic and the dileptonic channel are expected to improve as progress is made on the luminosity determination and the knowledge of the backgrounds from comparisons with measured data. A measurement of the cross-section ratio between the dileptonic and

Measurement of top quark and W boson polarisation observables with t-channel single-top-quark events in the ATLAS experiment.

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00288626

This thesis presents two studies, one related with the alignment of the ATLAS Inner Detector tracking system and other with the measurement of top quark and W boson polarisation observables using t-channel single-top-quark events. The first topic describes the implementation of a monitoring tool, which is used to monitor the Level 1 alignment corrections obtained in the calibration loop, as well as the use of constraints on the momentum and impact parameters biases using $Z \\rightarrow\\mu\\mu$ events on the alignment algorithms. These techniques were developed during 2012 data taking campaign and provide the most accurate description of the ATLAS Inner Detector. The second topic presents a detailed measurement of top quark and W boson polarisation observables using the 20.3 $fb^{-1}$ of data collected by the ATLAS detector at $\\sqrt{s}$ = 8 TeV. The measurement is performed using $t$-channel single top quark events and exploits the feature that the produced top quark is highly polarised along the direction of ...

Search for single top production through FCNC at ATLAS experiment

Energy Technology Data Exchange (ETDEWEB)

Alhroob, Muhammad; Brock, Ian [Universitaet Bonn, Bonn (Germany); Hirschbuehl, Dominic [Bergische Universitaet Wuppertal, Wuppertal (Germany)

2011-07-01

Flavour Changing Neutral Currents (FCNC) are strongly suppressed in the Standard Model due to the Glashow-Iliopoulos-Maiani (GIM) mechanism. Although absent at tree level, small FCNC contributions are expected at one-loop level, determined by the CKM mixing. For the top quark, within the framework of the Standard Model, the expected FCNC branching fractions to gauge bosons, e.g. t {yields}q+gluon, are predicted to be at the level of 10{sup -13}. There are, however, extensions of the SM, like supersymmetry (SUSY) and the 2-Higgs doublet model, which predict the presence of FCNC contributions already at tree level and significantly enhance the FCNC decay branching ratios compared to the Standard Model predictions. Our study concentrates on single top-quark production through FCNC, where the u(c) quark interacts with a gluon to produce a single top quark without any associated production. The top quark then decays as usual via the SM process, t {yields}W+b. An upper limit on the couplings {kappa}{sub ugt} and {kappa}{sub cgt} have been extracted from the first ATLAS data taken in 2010.

A Search for New High-Mass Phenomena Producing Top Quarks with the ATLAS Experiment

CERN Document Server

The ATLAS collaboration

2011-01-01

A search for top quark pair resonances in the lepton plus jets final states has been performed with the ATLAS experiment at the LHC. The search uses a data sample corresponding to an integrated luminosity of 33 pb$^{-1}$, and was recorded at a proton-proton centre-of-mass energy of 7 TeV. No evidence of a resonance is found. Using the reconstructed $t\\bar{t}$ mass spectrum, limits are set on the production cross-section times branching ratio to $t\\bar{t}$ for narrow $Z'$ models. The observed 95\\% C.L. limits range from approximately 55~pb to 2.2~pb for masses going from $m=$ 500 GeV to $m=$ 1000 GeV. The analysis is also used to set limits on enhanced top quark production at high $t+X$ mass, using the production of quantum black holes to model the signal. In that context, enhanced $t+X$ production with a mass threshold below 2.35 TeV is excluded.

Probing new physics at the LHC: searches for heavy top-like quarks with the ATLAS experiment

CERN Document Server

Succurro, Antonella; Casado Lechuga, María Pilar

Is our Standard Model (SM) of the fundamental particle interactions complete? Apparently, the answer is “no”. Many theories have been proposed to explain what is currently not understood, like the nature of Dark Matter, or the reason why the Higgs boson is so light. Now that the Large Hadron Collider (LHC) at CERN is fully operational, it is possible for experiments like ATLAS to explore very high-energy regimes where new physics can be probed. The work presented in this dissertation consists of two analyses aimed at the discovery (or exclusion) of a signal from a new particle: a quark similar to the top quark (the heaviest particle of the Standard Model) but with a larger mass. This new “top-like” quark could be a simple replica of the SM top quark, just with higher mass, i.e. a chiral fourth-generation up-type quark, or it could have exotic features. The latter hypothesis is particularly interesting as many “beyond-Standard Model” theories predict new heavy so-called vector-like quarks. Both sea...

A table top exercise and workshop

International Nuclear Information System (INIS)

Lakey, J.R.A.

1992-01-01

Table top exercises are widely applied in training for emergency preparedness and have long been a feature of Courses on Planning for Nuclear Emergencies. Experience of a large number of table top exercises is used to provide a classification of the types of exercise indicating the application and the disadvantages. The use of workshops is considered to be complementary rather than an alternative to teaching methods available from table top exercises. (author)

Implications of passive safety based on historical industrial experience

International Nuclear Information System (INIS)

Forsberg, C.W.

1988-01-01

In the past decade, there have been multiple proposals for applying different technologies to achieve passively safe light water reactors (LWRs). A key question for all such concepts is, ''What are the gains in safety, costs, and reliability for passive safety systems.'' Using several types of historical data, estimates have been made of gains from passive safety and operating systems, which are independent of technology. Proposals for passive safety in reactors usually have three characteristics: (1) Passive systems with no moving mechanical parts, (2) systems with far fewer components and (3) more stringent design criteria for safety-related and process systems. Each characteristic reduces the potential for an accident and may increase plant reliability. This paper addresses gains from items (1) and (2). Passive systems often allow adoption of more rigorous design criteria which would be either impossible or economically unfeasible for active systems. This important characteristic of passive safety systems cannot be easily addressed using historical industrial experience

The importance for nuclear safety of efficient feedback of operational experience

International Nuclear Information System (INIS)

1987-09-01

Experience of practical operation is a valuable source of information for improving and optimizing the safety and reliability of nuclear power plants. Therefore it is essential to collect information on abnormal events occurring at plants during operation and on all deviations from normal performance by systems and personnel that could be precursors of accidents. For this purpose it is necessary to establish hierarchical systems to feedback operational safety experience at utility, national and international levels and to make these systems as effective as possible. The present report attempts to identify the safety objectives of these systems, to analyse the difficulties presently encountered and to suggest possible improvements

Evaluation of operating experience for early recognition of deteriorating safety performance

International Nuclear Information System (INIS)

Beckmerhagen, I.A.; Berg, H.P.

2004-01-01

One of the most difficult challenges facing nuclear power plants is to recognize the early signs of degrading safety performance before regulatory requirements are imposed or serious incidents or accidents occur. Today, the nuclear industry is striving for collecting more information on occurrences that could improve the operational safety performance. To achieve this, the reporting threshold has been lowered from incidents to anomalies with minor or no impact to safety. Industry experience (also outside nuclear industry) has shown that these are typical issues which should be considered when looking for such early warning signs. Therefore, it is important that nuclear power plant operators have the capability to trend, analyse and recognize early warning signs of deteriorating performance. It is necessary that plant operators are sensitive to these warning signs which may not be immediately evident. Reviewing operating experience is one of the main tasks for plant operators in their daily activities. Therefore, self assessment should be at the centre of any operational safety performance programme. One way of applying a self assessment program is through the following four basic elements: operational data, events, safety basis, and related experience. This approach will be described in the paper in more details. (authors)

W-1 Sodium Loop Safety Facility experiment centerline fuel thermocouple performance

International Nuclear Information System (INIS)

Meyers, S.C.; Henderson, J.M.

1980-05-01

The W-1 Sodium Loop Safety Facility (SLSF) experiment is the fifth in a series of experiments sponsored by the Department of Energy (DOE) as part of the National Fast Breeder Reactor (FBR) Safety Assurance Program. The experiments are being conducted under the direction of Argonne National Laboratory (ANL) and Hanford Engineering Development Laboratory (HEDL). The irradiation phase of the W-1 SLSF experiment was conducted between May 27 and July 20, 1979, and terminated with incipient fuel pin cladding failure during the final boiling transient. Experimental hardware and facility performed as designed, allowing completion of all planned tests and test objectives. This paper focuses on high temperature in-fuel thermocouples and discusses their development, fabrication, and performance in the W-1 experiment

Does top executives’ US experience matter? Evidence from US-listed Chinese firms

Directory of Open Access Journals (Sweden)

Jingjing Li

2016-12-01

Full Text Available Foreign firms face enormous obstacles in attracting investors and analysts when issuing securities in the United States. We use US-listed Chinese firms as our research sample and find that firms that hire top executives (i.e., Chief Executive Officer [CEO] or Chief Financial Officer [CFO] with work experience in the US or educational qualifications from the US attract more US institutional investors and analysts. Further, we find that CFOs’ US experience dominates the results. Corroborating our results, we further find that firms with US-experienced CFOs are more likely to hold conference calls and voluntarily issue management forecasts, which suggests that CFOs with a US background are better at communicating with US investors and analysts and acting in alignment with US norms compared with Chinese CFOs. Collectively, our results suggest that hiring a CFO with a US background could facilitate cross-listed foreign firms to lower US investors’ and analysts’ information disadvantage.

TOP LINAC design; Progetto del TOP LINAC

Energy Technology Data Exchange (ETDEWEB)

Picardi, L; Ronsivalle, C; Vignati, A [ENEA, Centro Ricerche Frascati, Rome (Italy). Dip. Innovazione

1997-11-01

The report describes a linear accelerator for protons named TOP LINAC designed for the TOP (Terapia Oncologica con Protoni, Oncological Protontherapy) project launched by the Italian National Institute of Health (Istituto Superiore di Sanita`, ISS) to explore in collaboration with the biggest Oncological Hospital in Rome (Istituto Regina Elena, IRE) the potentialities of the therapy with accelerated protons and establish guide lines for the application of this new type of radiotherapy in comparison with the more traditional electron and x-rays radiotherapy. The concept of a compact accelerator for protontherapy applications bore within the Italian Hadrontherapy Collaboration (TERA Collaboration) with the aim to diffuse the protontherapy on the National territory. The ISS program plans to use the TOP linac proton beam also for production of PET (Positron Emission Tomography) radioisotopes and radiobiology studies. Official agreements are in course between ISS and ENEA which provides its experience in the industrial and medical accelerators for the design and the construction of the TOP linac. The accelerator that will be the first 3 GHz proton linac in the world, will be composed of a 428.3 MHz 7 Me V RFQ + DTL injector followed by a 7-65 Me V section of a 3 GHz SCDTL structure and a 65 - 200 Me V variable energy SCL 3 GHz structure. In particular the SCDTL section uses a highly innovative accelerating structure patented by ENEA. In this report the clinical and physical requests are discussed and a preliminary design of the whole machine is given.

Observation of single top-quark production with the CDF II experiment

International Nuclear Information System (INIS)

Lueck, J.

2010-01-01

We present the observation of electroweak single top-quark production using up to 3.2 fb -1 of data collected by the CDF experiment. Lepton plus jets candidate events are classified by four parallel analysis techniques: one likelihood discriminant, one matrix-element discriminant, one decision-tree discriminant, and one neural-network discriminant. These outputs are combined with a super discriminant based on a neural-network analysis in order to improve the expected sensitivity. In conjunction with one neural-network discriminant using a complementary dataset of MET plus jets events with a veto on identified leptons we observe a signal consistent with the standard model but inconsistent with the background-only model by 5.0 standard deviations, with a median expected sensitivity in excess of 5.9 standard deviations.

Observation of Single Top Quark production with the Cdf 2. Experiment

International Nuclear Information System (INIS)

Lueck, J.

2010-01-01

We present the observation of electroweak single top-quark production using up to 3.2 fb -1 of data collected by the Cdf experiment. Lepton plus jets candidate events are classified by four parallel analysis techniques: one likelihood discriminant, one matrix-element discriminant, one decision-tree discriminant, and one neural-network discriminant. These outputs are combined with a super discriminant based on a neural-network analysis in order to improve the expected sensitivity. In conjunction with one neural-network discriminant using a complementary dataset of Met plus jets events with a veto on identified leptons we observe a signal consistent with the standard model but inconsistent with the background-only model by 5.0 standard deviations, with a median expected sensitivity in excess of 5.9 standard deviations.

Safety Systems

Science.gov (United States)

Halligan, Tom

2009-01-01

Colleges across the country are rising to the task by implementing safety programs, response strategies, and technologies intended to create a secure environment for teachers and students. Whether it is preparing and responding to a natural disaster, health emergency, or act of violence, more schools are making campus safety a top priority. At…

Modelling and simulation in nuclear safety and the role of experiment

International Nuclear Information System (INIS)

Baek, W-P.

2015-01-01

'Full text:' Modeling and simulation (M&S) technology is a key element in assuring and enhancing the safety of nuclear installations. The M&S technology has been progressed continuously with the introduction of new designs, improved understanding on relevant physical processes, and the improvement of computing environment. This presentation covers the role, progresses and prospect of M&S technology relevant to nuclear safety. Special attention is given to the effective interaction between M&S and experiment. The expected role of experiment to motivate the advancement of M&S technology is emphasized with some typical examples. Finally, relevant R&D activities of Korea are introduced for thermal-hydraulics and severe accident safety. (author)

Identifying primary care patient safety research priorities in the UK: a James Lind Alliance Priority Setting Partnership.

Science.gov (United States)

Morris, Rebecca Lauren; Stocks, Susan Jill; Alam, Rahul; Taylor, Sian; Rolfe, Carly; Glover, Steven William; Whitcombe, Joanne; Campbell, Stephen M

2018-02-28

To identify the top 10 unanswered research questions for primary care patient safety research. A modified nominal group technique. UK. Anyone with experience of primary care including: patients, carers and healthcare professionals. 341 patients and 86 healthcare professionals submitted questions. A top 10, and top 30, future research questions for primary care patient safety. 443 research questions were submitted by 341 patients and 86 healthcare professionals, through a national survey. After checking for relevance and rephrasing, a total of 173 questions were collated into themes. The themes were largely focused on communication, team and system working, interfaces across primary and secondary care, medication, self-management support and technology. The questions were then prioritised through a national survey, the top 30 questions were taken forward to the final prioritisation workshop. The top 10 research questions focused on the most vulnerable in society, holistic whole-person care, safer communication and coordination between care providers, work intensity, continuity of care, suicide risk, complex care at home and confidentiality. This study was the first national prioritisation exercise to identify patient and healthcare professional priorities for primary care patient safety research. The research priorities identified a range of important gaps in the existing evidence to inform everyday practice to address primary care patient safety. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Development of thermal-hydraulic models for the safety evaluation of CANDU reactors

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Young; Hwang, Gi Suk; Jung, Yun Sik [Handong Univ., Pohang (Korea, Republic of); No, Hee Cheon; Moon, Young Min [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

2003-03-15

The objective of the present research is to evaluate the safety analysis for CANDU and to improve the Horizontal Stratification Entrainment Model (HSEM) of RELAP5/MOD3.3. This report includes two items : the one is the development of experimental facility for the safety evaluation of CANDU, the other is the results of comparison with the existing correlations and data. The literature reviews are performed and the database for previous off-take experiments are built. By a survey of state-of-the-articles, the deficiencies of previous works and limitations of existing models are examined. The hydraulic behavior branching through the feeder pipes from the header pipe is analyzed and the test facility of off-take experiment is designed and manufactured as the prototype CANDU6, by a proper scaling methodologies. The test facility contains various branch pipes not only for three directions (top, side and bottom), but for arbitrary directions. The experiments about the onset of entrainment and branch quality only for three directions (top, side and bottom) are carried out by using air-water as working fluids. On the whole, the existing correlations predict the present experimental results well branch quality, entrainment, which validates the availability of experimental facility and methodology. Especially, for the branch quality with top and bottom branches, the different results are shown because of the unstable flow regimes in the horizontal pipe and the different branch diameters. The deficiencies of previous works and limitations of existing models are considered. The off-take experiment for arbitrary branch angles continues as the next year research.

Nurses' experiences and perspectives on medication safety practices: an explorative qualitative study.

Science.gov (United States)

Smeulers, Marian; Onderwater, Astrid T; van Zwieten, Myra C B; Vermeulen, Hester

2014-04-01

To explore nurses' experiences with and perspectives on preventing medication administration errors. Insight into nurses' experiences with and perspectives on preventing medication administration errors is important and can be utilised to tailor and implement safety practices. A qualitative interview study of 20 nurses in an academic medical centre was conducted between March and December of 2011. Three themes emerged from this study: (1) nurses' roles and responsibilities in medication safety: aside from safe preparation and administration, the clinical reasoning of nurses is essential for medication safety; (2) nurses' ability to work safely: knowledge of risks and nurses' work circumstances influence their ability to work safely; and (3) nurses' acceptance of safety practices: advantages, feasibility and appropriateness are important incentives for acceptance of a safety practice. Nurses' experiences coincide with the assumption that they are in a pre-eminent position to enable safe medication management; however, their ability to adequately perform this role depends on sufficient knowledge to assess the risks of medication administration and on the circumstances in which they work. Safe medication management requires a learning climate and professional practice environment that enables further development of professional nursing skills and knowledge. © 2014 John Wiley & Sons Ltd.

Using the Tritium Plasma Experiment to evaluate ITER PFC safety

International Nuclear Information System (INIS)

Longhurst, G.R.; Anderl, R.A.; Bartlit, J.R.; Causey, R.A.; Haines, J.R.

1993-01-01

The Tritium Plasma Experiment was assembled at Sandia National Laboratories, Livermore to investigate interactions between dense plasmas at low energies and plasma-facing component materials. This apparatus has the unique capability of replicating plasma conditions in a tokamak divertor with particle flux densities of 2 x 10 19 ions/cm 2 · s and a plasma temperature of about 15 eV using a plasma that includes tritium. With the closure of the Tritium Research Laboratory at Livermore, the experiment was moved to the Tritium Systems Test Assembly facility at Los Alamos National Laboratory. An experimental program has been initiated there using the Tritium Plasma Experiment to examine safety issues related to tritium in plasma-facing components, particularly the ITER divertor. Those issues include tritium retention and release characteristics, tritium permeation rates and transient times to coolant streams, surface modification and erosion by the plasma, the effects of thermal loads and cycling, and particulate production. A considerable lack of data exists in these areas for many of the materials, especially beryllium, being considered for use in ITER. Not only will basic material behavior with respect to safety issues in the divertor environment be examined, but innovative techniques for optimizing performance with respect to tritium safety by material modification and process control will be investigated. Supplementary experiments will be carried out at the Idaho National Engineering Laboratory and Sandia National Laboratory to expand and clarify results obtained on the Tritium Plasma Experiment

LMFBR safety experiment facility planning and analysis

International Nuclear Information System (INIS)

Stevenson, M.G.; Scott, J.H.

1976-01-01

In the past two years considerable effort has been placed on the planning and design of new facilities for the resolution of LMFBR safety issues. The paper reviews the key issues, the experiments needed to resolve them, and the design aspects of proposed new facilities. In addition, it presents a decision theory approach to selecting an optimal combination of modified and new facilities

Evaluation of Saxton critical experiments

Energy Technology Data Exchange (ETDEWEB)

Joo, Hyung Kook; Noh, Jae Man; Jung, Hyung Guk; Kim, Young Il; Kim, Young Jin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1998-12-31

As a part of International Criticality Safety Benchmark Evaluation Project (ICSBEP), SAXTON critical experiments were reevaluated. The effects of k{sub eff} of the uncertainties in experiment parameters, fuel rod characterization, soluble boron, critical water level, core structure, {sup 241}Am and {sup 241}Pu isotope number densities, random pitch error, duplicated experiment, axial fuel position, model simplification, etc., were evaluated and added in benchmark-model k{sub eff}. In addition to detailed model, the simplified model for Saxton critical experiments was constructed by omitting the top, middle, and bottom grids and ignoring the fuel above water. 6 refs., 1 fig., 3 tabs. (Author)

Evaluation of Saxton critical experiments

Energy Technology Data Exchange (ETDEWEB)

Joo, Hyung Kook; Noh, Jae Man; Jung, Hyung Guk; Kim, Young Il; Kim, Young Jin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1997-12-31

As a part of International Criticality Safety Benchmark Evaluation Project (ICSBEP), SAXTON critical experiments were reevaluated. The effects of k{sub eff} of the uncertainties in experiment parameters, fuel rod characterization, soluble boron, critical water level, core structure, {sup 241}Am and {sup 241}Pu isotope number densities, random pitch error, duplicated experiment, axial fuel position, model simplification, etc., were evaluated and added in benchmark-model k{sub eff}. In addition to detailed model, the simplified model for Saxton critical experiments was constructed by omitting the top, middle, and bottom grids and ignoring the fuel above water. 6 refs., 1 fig., 3 tabs. (Author)

Use of operational experience in fire safety assessment of nuclear power plants

International Nuclear Information System (INIS)

2000-01-01

collection of data related to fire safety occurrences in NPPs, the so called operational experience and the use of such operational experience in NPPs. This report provides good practice information on data needs, data reporting requirements and some advice on database features. In addition, this publication provides information on the applications of fire related operational experience, highlighting their benefits. This publication has been developed to complement other IAEA publications related to fire safety analysis within the framework of the IAEA programme of fire safety

Combining Top-down and Bottom-up Accountability: Evidence from a Bribery Experiment.

OpenAIRE

Danila Serra

2008-01-01

Monitoring corruption typically relies on top-down interventions aimed at increasing the probability of external controls and the severity of punishment. An alternative approach to fighting corruption is to induce bottom-up pressure for reform. Recent studies have shown that both top-down and bottom-up mechanisms are rarely able to keep service providers accountable. This paper investigates the effectiveness of an accountability system that combines bottom-up monitoring and top-down auditing ...

Experience gained in enhancing operational safety at ComEd`s nuclear power plants

Energy Technology Data Exchange (ETDEWEB)

Elias, D [Commonwealth Edison Co. (United States)

1997-09-01

The following aspects of experience gained in enhancing operational safety at Comed`s nuclear power plants are discussed: nuclear safety policy; centralization/decentralization; typical nuclear operating organization; safety review boards; human performance enhancement; elements of effective nuclear oversight.

PReSaFe: A model of barriers and facilitators to patients providing feedback on experiences of safety.

Science.gov (United States)

De Brún, Aoife; Heavey, Emily; Waring, Justin; Dawson, Pamela; Scott, Jason

2017-08-01

The importance of involving patients in reporting on safety is increasingly recognized. Whilst studies have identified barriers to clinician incident reporting, few have explored barriers and facilitators to patient reporting of safety experiences. This paper explores patient perspectives on providing feedback on safety experiences. Patients (n=28) were invited to take part in semi-structured interviews when given a survey about their experiences of safety following hospital discharge. Transcripts were thematically analysed using NVivo10. Patients were recruited from four hospitals in the UK. Three themes were identified as barriers and facilitators to patient involvement in providing feedback on their safety experiences. The first, cognitive-cultural, found that whilst safety was a priority for most, some felt the term was not relevant to them because safety was the "default" position, and/or because safety could not be disentangled from the overall experience of care. The structural-procedural theme indicated that reporting was facilitated when patients saw the process as straightforward, but that disinclination or perceived inability to provide feedback was a barrier. Finally, learning and change illustrated that perception of the impact of feedback could facilitate or inhibit reporting. When collecting patient feedback on experiences of safety, it is important to consider what may help or hinder this process, beyond the process alone. We present a staged model of prerequisite barriers and facilitators and hypothesize that each stage needs to be achieved for patients to provide feedback on safety experiences. Implications for collecting meaningful data on patients' safety experiences are considered. © 2016 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

Presurized water reactor safety approach and analysis. From conception to experience feedback

International Nuclear Information System (INIS)

Libmann, J.

1987-04-01

This report deals in ten chapters, with the following subjects: 1. Safety approach methods; 2. Study of accidents; 3. Safety analysis; 4. Study of internal aggressions or those involved by the site; 5. Consideration of complementary situations; 6. Three Mile Island accident; 7. Safety during operation and experience feedback; 8. An example of analysis: steam generator closure plug; 9. Probabilistic safety evaluation; 10. Chernobyl accident. 30 refs [fr

Industry Operating Experience Process at Krsko NPP

International Nuclear Information System (INIS)

Bach, B.; Bozin, B.; Cizmek, R.

2012-01-01

Experience has shown that number of minor events and near misses, usually without immediate or significant impact to plant safety and reliability, are precursors of significant or severe events due to the same or similar root or apparent cause(s). It is therefore desirable to identify and analyze weaknesses of the precursor problems (events) in order to prevent occurrence of significant events. Theoretically, significant events could be prevented from occurring if the root cause(s) of these precursor problems could be identified and eliminated. The Operating Experience Program identifies such event precursors and by reporting them to the industry, plant specific corrective actions can be taken to prevent events at other operational plants. The intent of the Operating Experience Program is therefore to improve nuclear power plant safety and reliability of the operating nuclear power plants. Each plant develops its own Operating Experience Program in order to learn from the in-house operating experience as well as from the world community of nuclear plants. The effective use of operating experience includes analyzing both plant and industry events in order to identify fundamental weaknesses and then determining appropriate plant-specific actions that will minimize the likelihood of similar events. Learning and applying the lessons from operating experience is an integral part of station safety culture and is encouraged by managers throughout the top plant administrative programs and procedures. Krsko NPP is developed it own Operating Experience Program by using the most relevant INPO/WANO/IAEA guidelines as well as its own knowledge, skills an operating practice. The Operating Experience Program is a part of the Corrective Action Program, which is among top management programs, thus program is strongly encouraged by top management. The purpose of Operating Experience Program is to provide guidance for using, sharing, and evaluating operating experience information

Sensitivity of the Top quark mass measurement with the CMS experiment at LHC using t-tbar multijet simulated events

CERN Document Server

Codispoti, Giuseppe

This thesis comes after a strong contribution on the realization of the CMS computing system, which can be seen as a relevant part of the experiment itself. A physics analysis completes the road from Monte Carlo production and analysis tools realization to the final physics study which is the actual goal of the experiment. The topic of physics work of this thesis is the study of tt events fully hadronic decay in the CMS experiment. A multi-jet trigger has been provided to fix a reasonable starting point, reducing the multi-jet sample to the nominal trigger rate. An offline selection has been provided to reduce the S/B ratio. The b-tag is applied to provide a further S/B improvement. The selection is applied to the background sample and to the samples generated at different top quark masses. The top quark mass candidate is reconstructed for all those samples using a kinematic fitter. The resulting distributions are used to build p.d.f.’s, interpolating them with a continuous arbitrary curve. These curves are...

Constraints on the top quark's charge with the CMS experiment

Energy Technology Data Exchange (ETDEWEB)

Kuessel, Yvonne

2013-02-15

The standard model of particle physics is being probed at the LHC collider ring at Geneva. Amongst others, top-quark pairs are produced in large quantities. This makes precision measurements of top-quark properties possible. The top quark as the electroweak-isospin partner of the bottom quark is expected to have an electric charge of +2/3 e. A measurement is presented that discriminates between the top quark charge hypotheses of +2/3 e and -4/3 e using the muon+jets final state of top-pair events t anti t{yields}(b{mu}{nu})(bqq'). The measurement is performed with proton-proton collisions at {radical}(s)=7 TeV recorded by the CMS detector in the year 2011, corresponding to an integrated luminosity of 5.0 fb{sup -1}. Charge correlations between the high-p{sub T} muons from the hard process and a muon from one of the bottom quarks are exploited to sort the events in a +2/3 e or -4/3 e category. The normalized asymmetry between both categories is calculated. The top quark charge scenario of -4/3 e would correspond to an asymmetry of A=-1. This is excluded with high significance while the measured asymmetry of A=1.10{+-}0.12(stat.){+-}0.34(sys.) confirms the standard-model expectation of A=+1.

Measurement of the charge asymmetry in top-antitop quark production with the CDF II experiment

Energy Technology Data Exchange (ETDEWEB)

Weinelt, Julia; /Karlsruhe U., EKP

2006-12-01

The Fermi National Laboratory (Fermilab) operates the Tevatron proton-antiproton collider at a center-of-mass energy of {radical}s = 1.96 TeV, the is therefore the only collider which is today able to produce the heaviest known particle, the top quark. The top quark was discovered at the Tevatron by the CDF and D0 collaborations in 1995. At the Tevatron, most top quarks are produced via the strong interaction, whereby quark-antiquark annihilation dominates with 85%, and gluon fusion contributes with 15%. Considering next-to-leading order (NLO) contributions in the cross section of top-antitop quark production, leads to a slight positive asymmetry in the differential distribution of the production angle {alpha} of the top quarks. This asymmetry is due to the interference of certain NLO contributions. The charge asymmetry A in the cosine of {alpha} is predicted [14] to amount to 4-6%. Information about the partonic rest frame, necessary for a measurement of A in the observable cos {alpha}, is not accessible in the experiment. Thus, they use the rapidity difference of the top and the antitop quark as sensitive variable. This quantity offers the advantage of Lorentz invariance and is uniquely correlated with the cosine of {alpha}, justifying the choice of the rapidity difference to describe the behavior of cos {alpha}. In preparation for a measurement of the charge asymmetry, they conduct several Monte Carlo based studies concerning the effect of different event selection criteria on the asymmetry in the selected event samples. They observe a strong dependence of the measured asymmetry on the number of required jets in the particular event sample. This motivates further studies to understand the influence of additional gluon radiation, which leads to more than four observed jets in an event, on the rapidity distribution of the produced top quarks. They find, that events containing hard gluon radiation are correlated with a strong negative shift of the rapidity

Planning the Unplanned Experiment: Assessing the Efficacy of Standards for Safety Critical Software

Science.gov (United States)

Graydon, Patrick J.; Holloway, C. Michael

2015-01-01

We need well-founded means of determining whether software is t for use in safety-critical applications. While software in industries such as aviation has an excellent safety record, the fact that software aws have contributed to deaths illustrates the need for justi ably high con dence in software. It is often argued that software is t for safety-critical use because it conforms to a standard for software in safety-critical systems. But little is known about whether such standards `work.' Reliance upon a standard without knowing whether it works is an experiment; without collecting data to assess the standard, this experiment is unplanned. This paper reports on a workshop intended to explore how standards could practicably be assessed. Planning the Unplanned Experiment: Assessing the Ecacy of Standards for Safety Critical Software (AESSCS) was held on 13 May 2014 in conjunction with the European Dependable Computing Conference (EDCC). We summarize and elaborate on the workshop's discussion of the topic, including both the presented positions and the dialogue that ensued.

Proceedings of 2nd PHWR operating safety experience meeting

Energy Technology Data Exchange (ETDEWEB)

NONE

1991-04-01

Papers presented during the eight sessions of the meeting were devoted to the impact of PHWR operating experience on design of civil structures (reactor building integrity); operating experiences related to pressure tubes, nuclear steam supply system, plant stability; reactor maintenance and control systems, reactor operational safety. Some events concerned with reactor shutdown due to power failures are described, as well as action undertaken to prevent major damage.

Proceedings of 2nd PHWR operating safety experience meeting

International Nuclear Information System (INIS)

1991-04-01

Papers presented during the eight sessions of the meeting were devoted to the impact of PHWR operating experience on design of civil structures (reactor building integrity); operating experiences related to pressure tubes, nuclear steam supply system, plant stability; reactor maintenance and control systems, reactor operational safety. Some events concerned with reactor shutdown due to power failures are described, as well as action undertaken to prevent major damage

Top quark properties at ATLAS

CERN Document Server

Dilip, Jana

2008-01-01

The ATLAS potential for the study of the top quark properties and physics beyond the Standard Model in the top quark sector, is described. The measurements of the top quark charge, the spin and spin correlations, the Standard Model decay (t-> bW), rare top quark decays associated to flavour changing neutral currents (t-> qX with X = gluon, Z, photon) and ttbar resonances are discussed. The sensitivity of the ATLAS experiment is estimated for an expected luminosity of 1fb-1 at the LHC. The full simulation of the ATLAS detector is used. For the Standard Model measurements the expected precision is presented. For the tests of physics beyond the Standard Model, the 5 sigma discovery potential (in the presence of a signal) and the 95% Confidence Level (CL) limit (in the absence of a signal) are given.

Experience related to the safety of advanced LMFBR fuel elements

International Nuclear Information System (INIS)

Kerrisk, J.F.

1975-07-01

Experiments and experience relative to the safety of advanced fuel elements for the liquid metal fast breeder reactor are reviewed. The design and operating parameters and some of the unique features of advanced fuel elements are discussed breifly. Transient and steady state overpower operation and loss of sodium bond tests and experience are discussed in detail. Areas where information is lacking are also mentioned

The significance of the heavy top quark

International Nuclear Information System (INIS)

Simmons, Elizabeth H.

1997-01-01

Experiment shows that the top quark is far heavier than the other elementary fermions. This finding has stimulated research on theories of electroweak and flavor symmetry breaking that include physics beyond the standard model. Efforts to accommodate a heavy top quark within existing frameworks have revealed constraints on model-building. Other investigations have started from the premise that a large top quark mass could signal a qualitative difference between the top quark and other fermions, perhaps in the form of new interactions peculiar to the top quark. Such new dynamics may also help answer existing questions about electroweak and flavor physics. This talk explores the implications of the heavy top quark in the context of weakly-coupled (e.g., SUSY) and strongly-coupled (e.g., technicolor) theories of electroweak symmetry breaking

The experience of WNTI with Safety and Security Worldwide

International Nuclear Information System (INIS)

Neau, Henry-Jacques

2016-01-01

This paper gives an industrial perspective on safety and security issues based on the experience of WNTI members. It describes how safety is invested primarily in the package; not how the package is transported. Transport safety is therefore an engineering challenge, and all necessary technical information is available to enable this to be met. Security in transport involves various measures to guard against intentional malicious acts. The paper describes the international instruments relevant to security in the transport of nuclear fuel cycle materials and how both safety and security regulations must be coordinated and simplified to avoid conflicts. It considers potential risks, which must not be underestimated. However, the assessment of risks must be realistic and quantified, and the requirements placed on the industry appropriate. It is important to dispel exaggerated perceptions of danger in the minds of the public, politicians and regulators. (author)

EXPERIENCE OF APPLICATION OF FOREIGN MODELS OF STIMULATION OF WORK OF TOP-MANAGERS AT THE RUSSIAN ENTERPRISE OF HEAVY MECHANICAL ENGINEERING

Directory of Open Access Journals (Sweden)

A.A. Levchenko

2009-09-01

Full Text Available For today many domestic enterprises of sphere of production of goods feel sharp need for change of system of stimulation of work of the organization. Foreign experience of stimulation of work of top-managers is actively made use. In clause the example of application of the adapted foreign system of awarding of top-managers at the Russian enterprise is presented on the basis of regulations about of motivation of key heads business-battalions corporations.

The top-down reflooding model in the Cathare code

International Nuclear Information System (INIS)

Bartak, J.; Bestion, D.; Haapalehto, T.

1993-01-01

A top-down reflooding model was developed for the French best-estimate thermalhydraulic code CATHARE. The paper presents the current state of development of this model. Based on a literature survey and on compatibility considerations with respect to the existing CATHARE bottom reflooding package, a falling film top-down reflooding model was developed and implemented into CATHARE version 1.3E. Following a brief review of previous work, the paper describes the most important features of the model. The model was validated with the WINFRITH single tube top-down reflooding experiment and with the REWET - II simultaneous bottom and top-down reflooding experiment in rod bundle geometry. The results demonstrate the ability of the new package to describe the falling film rewetting phenomena and the main parametric trends both in a simple analytical experimental setup and in a much more complex rod bundle reflooding experiment. (authors). 9 figs., 28 refs

Top quark mass measurement in the dilepton channel during the D0 experiment at the Tevatron. Mesure de la masse du quark top dans les canaux di-leptoniques auprès de l’expérience D0 au Tevatron

Energy Technology Data Exchange (ETDEWEB)

Croc, Aurelien [Commissariat a l' Energie Atomique et aux Energies Alternatives (CEA) Saclay, Gif-sur-Yvette (France). IRFU

2011-01-01

The top quark is the heaviest standard model quark. Discovered in 1995 by the two Tevatron experiments it has atypical properties. In particular its time life is so short that it decays before hadronizing, so the top quark mass could be measured with a high precision. Data collected by the DØ experiment between 2002 and 2009, which represent an integrated luminosity of 5.4 fb⁻¹, are used to measure the top quark mass by using the matrix element method in the three dilepton channels: dielectron, electron--muon and dimuon. The measured mass, 174.0 ± 1.8 (stat.) ± 2.4 (syst.) GeV, is in a good agreement with other measurements and limited by the systematic uncertainties for the first time in these channels. In this thesis different approaches have been studied to improve the accuracy of this measurement: the use of b-quark jet identification in order to optimize the selection of top--anti-top events and a better determination of the main systematic uncertainties. A special attention has been paid to the Monte-Carlo simulation of muons in D0: the improved smearing procedure for the simulated muons, discussed in this thesis, will be used to increase the accuracy of the top properties measurements as well as the precision of many other D0 measurements.

Leadership for safety: industrial experience.

Science.gov (United States)

Flin, R; Yule, S

2004-12-01

The importance of leadership for effective safety management has been the focus of research attention in industry for a number of years, especially in energy and manufacturing sectors. In contrast, very little research into leadership and safety has been carried out in medical settings. A selective review of the industrial safety literature for leadership research with possible application in health care was undertaken. Emerging findings show the importance of participative, transformational styles for safety performance at all levels of management. Transactional styles with attention to monitoring and reinforcement of workers' safety behaviours have been shown to be effective at the supervisory level. Middle managers need to be involved in safety and foster open communication, while ensuring compliance with safety systems. They should allow supervisors a degree of autonomy for safety initiatives. Senior managers have a prime influence on the organisation's safety culture. They need to continuously demonstrate a visible commitment to safety, best indicated by the time they devote to safety matters.

Top quarks at the Tevatron: Measurements of the top quark production and decay with the D0 experiment

Energy Technology Data Exchange (ETDEWEB)

Strandberg, Jonas [Stockholm Univ. (Sweden)

2006-01-01

This thesis presents two measurements of the to pquark using 230 pb^-1 of data recorded with the D0 detector at the Tevatron accelerator. The first measurement determines the top pair production cross section at √s = 1.96 TeV in proton-antiproton collisions. In the standard model of particle physics the top quark decays almost exclusively into a W boson and a b quark. Candidate events are selected by requiring that at least one jet in the event is tagged with the secondary vertex algorithm.

Top reconstruction and boosted top experimental overview

CERN Document Server

Skinnari, Louise

2015-01-01

An overview of techniques used to reconstruct resolved and boosted top quarks is presented. Techniques for resolved top quark reconstruction include kinematic likelihood fitters and pseudo- top reconstruction. Many tools and methods are available for the reconstruction of boosted top quarks, such as jet grooming techniques, jet substructure variables, and dedicated top taggers. Different techniques as used by ATLAS and CMS analyses are described and the performance of different variables and top taggers are shown.

A GENERALIZED NON-LINEAR METHOD FOR DISTORTION CORRECTION AND TOP-DOWN VIEW CONVERSION OF FISH EYE IMAGES

Directory of Open Access Journals (Sweden)

Vivek Singh Bawa

2017-06-01

Full Text Available Advanced driver assistance systems (ADAS have been developed to automate and modify vehicles for safety and better driving experience. Among all computer vision modules in ADAS, 360-degree surround view generation of immediate surroundings of the vehicle is very important, due to application in on-road traffic assistance, parking assistance etc. This paper presents a novel algorithm for fast and computationally efficient transformation of input fisheye images into required top down view. This paper also presents a generalized framework for generating top down view of images captured by cameras with fish-eye lenses mounted on vehicles, irrespective of pitch or tilt angle. The proposed approach comprises of two major steps, viz. correcting the fish-eye lens images to rectilinear images, and generating top-view perspective of the corrected images. The images captured by the fish-eye lens possess barrel distortion, for which a nonlinear and non-iterative method is used. Thereafter, homography is used to obtain top-down view of corrected images. This paper also targets to develop surroundings of the vehicle for wider distortion less field of view and camera perspective independent top down view, with minimum computation cost which is essential due to limited computation power on vehicles.

Precision Determination of the Top Quark Mass

Energy Technology Data Exchange (ETDEWEB)

Movilla Fernandez, Pedro A.; /LBL, Berkeley

2007-05-01

The CDF and D0 collaborations have updated their measurements of the mass of the top quark using proton-antiproton collisions at {radical}s = 1.96 TeV produced at the Tevatron. The uncertainties in each of the top-antitop decay channels have been reduced. The new Tevatron average for the mass of the top quark based on about 1 fb{sup -1} of data per experiment is 170.9 {+-} 1.8 GeV/c{sup 2}.

Safety aspects and operating experience of LWR plants in Japan

International Nuclear Information System (INIS)

Aoki, S.; Hinoki, M.

1977-01-01

From the outset of nuclear power development in Japan, major emphasis has been placed on the safety of the nuclear power plants. There are now twelve nuclear power plants in operation with a total output of 6600 MWe. Their operating records were generally satisfactory, but in the 1974 to 1975 period, they experienced somewhat declined availability due to the repair work under the specific circumstances. After investigation of causes of troubles and the countermeasures thereof were made to ensure safety, they are now keeping good performance. In Japan, nuclear power plants are strictly subject to sufficient and careful inspection in compliance with the safety regulation, and are placed under stringent radiation control of employees. Under the various circumstances, however, the period of annual inspection tends to be prolonged more than originally planned, and this consequently is considered to be one of the causes of reduced availability. In order to develop nuclear power generation for the future, it is necessary to put further emphasis on the assurance of safety and to endeavor to devise measures to improve availability of the plants, based on the careful analysis of causes which reduce plant availability. This paper discusses the results of studies made for the following items from such viewpoints: (1) Safety and Operating Experience of LWR Nuclear Power Plants in Japan; a) Operating experience with light water reactors b) Improvements in design of light water reactors during the past ten years c) Analysis of the factors which affect plant availability; 2) Assurance of Safety and Measures to Increase Availability a) Measures for safety and environmental protection b) Measures to reduce radiation exposure of employees c) Appropriateness of maintenance and inspection work d) Measures to increase plant availability e) Measures to improve reliability of equipments and components; and 3) Future Technical Problems

The CERN Detector Safety System for LHC Experiments

CERN Document Server

Lüders, S; Morpurgo, G; Schmeling, S M

2003-01-01

The Detector Safety System (DSS), developed at CERN in common for the four LHC experiments under the auspices of the Joint Controls Project (JCOP), will be responsible for assuring the equipment protection for these experiments. Therefore, the DSS requires a high degree of both availability and reliability. It is composed of a Front-end and a Back-end part. The Front-end is based on a redundant Siemens PLC, to which the safety-critical part of the DSS task is delegated. The PLC Front-end is capable of running autonomously and of automati-cally taking predefined protective actions whenever re-quired. It is supervised and configured by the CERN-cho-sen PVSS SCADA system via a Siemens OPC server. The supervisory layer provides the operator with a status display and with limited online reconfiguration capabili-ties. Configuration of the code running in the PLCs is completely data driven via the contents of a ?Configura-tion Database?. Thus, the DSS can easily adapt to the different and constantly evolving require...

Searches for heavy resonances in all-jet final states with top quarks using jet substructure techniques with the CMS experiment

Energy Technology Data Exchange (ETDEWEB)

Usai, Emanuele

2017-12-15

While the Standard Model is very successful in describing subnuclear phenomena, it is not a complete theory of particle physics. Several new theories have been developed to address its issues. Many extensions of the Standard Model predict the existence of high-mass resonances. In some cases these resonances have an enhanced coupling to third generation quarks or to a hypothetical new generation of heavy non-chiral quarks. This thesis describes two searches for new phenomena compatible with these theories, in particular a search is presented for resonant top-antitop production, and the first search for heavy resonances decaying to a top quark and a heavy top quark partner T is shown. The searches target the all-jets decay channels and use data collected by the CMS Experiment at the CERN LHC between 2012 and 2015 at a center-of-mass energy of 8 TeV and 13 TeV. Due to the high mass of the resonances considered, the final state particles have a high Lorentz-boost. To reconstruct the hadronic decay of the top quarks and W bosons, jet substructure techniques such as top quark and W boson tagging algorithms, and boosted b jet identification are employed. These algorithms are studied with a particular focus on their validation and performance assessment. No signs of physics beyond the Standard Model are observed, but stringent limits are placed on the production of heavy resonances decaying to top-antitop quark pairs or a top quark and a heavy T quark.

Searches for heavy resonances in all-jet final states with top quarks using jet substructure techniques with the CMS experiment

International Nuclear Information System (INIS)

Usai, Emanuele

2017-12-01

While the Standard Model is very successful in describing subnuclear phenomena, it is not a complete theory of particle physics. Several new theories have been developed to address its issues. Many extensions of the Standard Model predict the existence of high-mass resonances. In some cases these resonances have an enhanced coupling to third generation quarks or to a hypothetical new generation of heavy non-chiral quarks. This thesis describes two searches for new phenomena compatible with these theories, in particular a search is presented for resonant top-antitop production, and the first search for heavy resonances decaying to a top quark and a heavy top quark partner T is shown. The searches target the all-jets decay channels and use data collected by the CMS Experiment at the CERN LHC between 2012 and 2015 at a center-of-mass energy of 8 TeV and 13 TeV. Due to the high mass of the resonances considered, the final state particles have a high Lorentz-boost. To reconstruct the hadronic decay of the top quarks and W bosons, jet substructure techniques such as top quark and W boson tagging algorithms, and boosted b jet identification are employed. These algorithms are studied with a particular focus on their validation and performance assessment. No signs of physics beyond the Standard Model are observed, but stringent limits are placed on the production of heavy resonances decaying to top-antitop quark pairs or a top quark and a heavy T quark.

International Handbook of Evaluated Criticality Safety Benchmark Experiments - ICSBEP (DVD), Version 2013

International Nuclear Information System (INIS)

2013-01-01

The Criticality Safety Benchmark Evaluation Project (CSBEP) was initiated in October of 1992 by the United States Department of Energy. The project quickly became an international effort as scientists from other interested countries became involved. The International Criticality Safety Benchmark Evaluation Project (ICSBEP) became an official activity of the Organisation for Economic Co-operation and Development (OECD) Nuclear Energy Agency (NEA) in 1995. This handbook contains criticality safety benchmark specifications that have been derived from experiments performed at various nuclear critical experiment facilities around the world. The benchmark specifications are intended for use by criticality safety engineers to validate calculational techniques used to establish minimum subcritical margins for operations with fissile material and to determine criticality alarm requirement and placement. Many of the specifications are also useful for nuclear data testing. Example calculations are presented; however, these calculations do not constitute a validation of the codes or cross section data. The evaluated criticality safety benchmark data are given in nine volumes. These volumes span nearly 66,000 pages and contain 558 evaluations with benchmark specifications for 4,798 critical, near critical or subcritical configurations, 24 criticality alarm placement/shielding configurations with multiple dose points for each and 200 configurations that have been categorised as fundamental physics measurements that are relevant to criticality safety applications. New to the Handbook are benchmark specifications for Critical, Bare, HEU(93.2)- Metal Sphere experiments referred to as ORSphere that were performed by a team of experimenters at Oak Ridge National Laboratory in the early 1970's. A photograph of this assembly is shown on the front cover

Measurement of the charge asymmetry and the W boson helicity in top-antitop quark events with the CDF II experiment

Energy Technology Data Exchange (ETDEWEB)

Hirschbuehl, Dominic [Univ. of Karlsruhe (Germany)

2005-12-23

In 1995 the heaviest elementary particle, top quark, was discovered at the Tevatron collider in top-antitop quark pair production. Since the top quark mass is of the same order as the electroweak symmetry breaking scale, measurements of the properties of the top quark like mass, charge, spin or the production mechanism, offer a good opportunity to test the Standard Model at such high energies. Top quarks at the Tevatron are predominantly pair-produced through light quark-antiquark annihilation. Higher order perturbative QCD calculations predict a sizeable asymmetry between the number of top quarks and antitop quarks produced in forward direction. This asymmetry is induced through radiative corrections. A measurement of the asymmetry can check the perturbative QCD predictions. Due to the high mass of the top quark, nearly the mass of a gold nucleus, the life time of the top quark is much shorter than the hadronization time-scale. This means that the top quark decays before it has a chance to form a bound state. The Standard Model predicts that the top quark decays in nearly 100% of the cases into a W boson and a b quark via a charge-current weak interaction. The measurement of the W boson helicity probes the V-A structure of the weak interaction and differences to the expectation would give evidence for new physics. Until the start of the Large Hadron Collider at CERN, the Tevatron is the only experiment where top quarks can be directly produced and their properties be measured. The Tevatron reaches a center-of-mass energy of 1.96 TeV in proton antiproton collisions. The data used in this analysis were taken in Run II of the Tevatron with the Collider Detector at Fermilab (CDF) in the years 2001-2004 and represent an integrated luminosity of 319 pb{sup -1}. The thesis is organized in the following way: In the first chapter a short overview of the Standard Model is given. The theoretical aspects of the top quark decay are described with particular emphasis on the

Measurement of the top quark mass

International Nuclear Information System (INIS)

Blusk, Steven R.

1998-01-01

The first evidence and subsequent discovery of the top quark was reported nearly 4 years ago. Since then, CDF and D0 have analyzed their full Run 1 data samples, and analysis techniques have been refined to make optimal use of the information. In this paper, we report on the most recent measurements of the top quark mass, performed by the CDF and D0 collaborations at the Fermilab Tevatron. The CDF collaboration has performed measurements of the top quark mass in three decay channels from which the top quark mass is measured to be 175.5 ± 6.9 GeV=c 2 . The D0 collaboration combines measurements from two decay channels to obtain a top quark mass of 172.1 ± 7.1 GeV/c 2 . Combining the measurements from the two experiments, assuming a 2 GeV GeV/c 2 correlated systematic uncertainty, the measurement of the top quark mass at the Tevatron is 173.9 ± 5.2 GeV/c 2 . This report presents the measurements of the top quark mass from each of the decay channels which contribute to this measurement

Raising occupational safety - an exceptionally important top rank task

Energy Technology Data Exchange (ETDEWEB)

1986-09-01

Comments on the Consulting Meeting on Safety at Work and Fire Prevention in the state association Energetika, held at the Bobov Dol coal mine on 27.7.1986. The main report, submitted by S. Mishev, manager of the state inspectorate, stated that in 1985 working conditions of 1,074 employees improved significantly and the number of accidents among workers was reduced by a coefficient of 1.92 points compared to 1984. Thirty-eight million levs were spent on improving occupational safety (reducing dust, noise and vibration levels). Measures aimed at preventing fires, in particular at the Maritsa-Iztok briquetting plant and in the Babino coal mine were improved significantly (fire-resistant support of mainroads, backfilling and isolation of goaf, application of anti-pyrogens, methane drainage, remote methane control, etc.). The number of annual inspections by safety inspectors has increased to 9,000. Coefficient of absenteeism due to bodily injury has been reduced by 40.57 points. Dust exposure of miners has also been reduced.

Toward the Extreme Ultra Violet Four Wave Mixing Experiments: From Table Top Lasers to Fourth Generation Light Sources

Directory of Open Access Journals (Sweden)

Riccardo Cucini

2015-01-01

Full Text Available Three different Transient Grating setups are presented, with pulsed and continuous wave probe at different wavelengths, ranging from infrared to the extreme ultra violet region. Both heterodyne and homodyne detections are considered. Each scheme introduces variations with respect to the previous one, allowing moving from classical table top laser experiments towards a new four wave mixing scheme based on free electron laser radiation. A comparison between the various setups and the first results from extreme ultra violet transient grating experiments is also discussed.

Recent top physics results from CMS

CERN Multimedia

CERN. Geneva

2014-01-01

The top quark, discovered in 1995 at the Tevatron, is the heaviest known elementary particle. The largeness of its mass gives rise to a number of peculiar properties: top quarks decay before they would hadronize and the measurement of their decay products provides direct access to its properties such as spin, charge, or polarization. The top quark couples most strongly with the Higgs boson, and plays a key role in the electro-weak symmetry breaking and in many scenarios of physics beyond the Standard Model. With its large center-of-mass energy and luminosity, the LHC produces top quarks in copious quantities, giving access to many new precision measurements. In this seminar, I will present recent measurements from the CMS experiment. I will focus in particular on the results on single-top quark production, where results are available in all production modes, the t-, the s- and the tW-channels. Furthermore, I will present recent measurements of top quark properties as well as searches for anomalous couplings ...

TOP AND HIGGS PHYSICS AT THE HADRON COLLIDERS

Energy Technology Data Exchange (ETDEWEB)

Jabeen, Shabnam

2013-10-20

This review summarizes the recent results for top quark and Higgs boson measurements from experiments at Tevatron, a proton–antiproton collider at a center-of-mass energy of √ s =1 . 96 TeV, and the Large Hadron Collider, a proton–proton collider at a center- of-mass energy of √ s = 7 TeV. These results include the discovery of a Higgs-like boson and measurement of its various properties, and measurements in the top quark sector, e.g. top quark mass, spin, charge asymmetry and production of single top quark.

Experience With Laser Safety In The USA--A Review

Science.gov (United States)

Sliney, David H.

1986-10-01

Following several research programs in the 1960's aimed at studying the adverse biological effects of lasers and other optical radiation sources, laser occupational exposure limits were set and general safety standards were developed. Today, the experience from laser accidents and the development of new lasers and new applications have altered the format of the exposure limits and the safety procedures. It is critically important to distinguish between different biological injury mechanisms. The biological effects of ultraviolet radiation upon the skin and eye are additive over a period of at least one workday, and require different safety procedures. The scattered UV irradiance from excimer lasers may be quite hazardous, depending upon wavelength and action spectra. Since laser technology is young, the exposure of an individual in natural sunlight must be studied to evaluate the potential for chronic effects. The safety measures necessary in the use of lasers depend upon a hazard evaluation. The appropriate control measures and alternate means of enclosure, baffling, and operational control measures are presented. Present laser safety standards are explained briefly. Eye protective techniques and eyewear are considered for a variety of sources. The optical properties of enclosure materials are also discussed.

Top-quark pair production in a running mass scheme

International Nuclear Information System (INIS)

Dowling, M.; Moch, S.; Hamburg Univ.

2013-11-01

Between the Tevatron and LHC, top-quark physics is now becoming an area for precision physics. This has lead to an increase in theoretical activity to match the experimental accuracy of top anti-top production. We discuss the difficulty in properly defining the top-quark mass as measured by experiments and present results for differential distributions of top-quark pair production in a running mass scheme. The use of such a scheme shows better convergence in the perturbative expansion and improves the scale dependence as opposed to the typical on-shell scheme.

Top-quark pair production in a running mass scheme

Energy Technology Data Exchange (ETDEWEB)

Dowling, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Moch, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik

2013-11-15

Between the Tevatron and LHC, top-quark physics is now becoming an area for precision physics. This has lead to an increase in theoretical activity to match the experimental accuracy of top anti-top production. We discuss the difficulty in properly defining the top-quark mass as measured by experiments and present results for differential distributions of top-quark pair production in a running mass scheme. The use of such a scheme shows better convergence in the perturbative expansion and improves the scale dependence as opposed to the typical on-shell scheme.

Conflict-Triggered Top-Down Control: Default Mode, Last Resort, or No Such Thing?

Science.gov (United States)

Bugg, Julie M.

2014-01-01

The conflict monitoring account posits that globally high levels of conflict trigger engagement of top-down control; however, recent findings point to the mercurial nature of top-down control in high conflict contexts. The current study examined the potential moderating effect of associative learning on conflict-triggered top-down control engagement by testing the Associations as Antagonists to Top-Down Control (AATC) hypothesis. In 4 experiments, list-wide proportion congruence was manipulated, and conflict-triggered top-down control engagement was examined by comparing interference for 50% congruent items across mostly congruent (low conflict) and mostly incongruent (high conflict) lists. Despite the fact that global levels of conflict were varied identically across experiments, evidence of conflict-triggered top-down control engagement was selective to those experiments in which responses could not be predicted on the majority of trials via simple associative learning, consistent with the AATC hypothesis. In a fifth experiment, older adults showed no evidence of top-down control engagement under conditions in which young adults did, a finding that refined the interpretation of the patterns observed in the prior experiments. Collectively, these findings suggest that top-down control engagement in high conflict contexts is neither the default mode nor an unused (or non-existent) strategy. Top-down control is best characterized as a last resort that is engaged when reliance on one’s environment, and in particular associative responding, is unproductive for achieving task goals. PMID:24274385

Large-Scale Spacecraft Fire Safety Experiments in ISS Resupply Vehicles

Science.gov (United States)

Ruff, Gary A.; Urban, David

2013-01-01

Our understanding of the fire safety risk in manned spacecraft has been limited by the small scale of the testing we have been able to conduct in low-gravity. Fire growth and spread cannot be expected to scale linearly with sample size so we cannot make accurate predictions of the behavior of realistic scale fires in spacecraft based on the limited low-g testing to date. As a result, spacecraft fire safety protocols are necessarily very conservative and costly. Future crewed missions are expected to be longer in duration than previous exploration missions outside of low-earth orbit and accordingly, more complex in terms of operations, logistics, and safety. This will increase the challenge of ensuring a fire-safe environment for the crew throughout the mission. Based on our fundamental uncertainty of the behavior of fires in low-gravity, the need for realistic scale testing at reduced gravity has been demonstrated. To address this concern, a spacecraft fire safety research project is underway to reduce the uncertainty and risk in the design of spacecraft fire safety systems by testing at nearly full scale in low-gravity. This project is supported by the NASA Advanced Exploration Systems Program Office in the Human Exploration and Operations Mission Directorate. The activity of this project is supported by an international topical team of fire experts from other space agencies to maximize the utility of the data and to ensure the widest possible scrutiny of the concept. The large-scale space flight experiment will be conducted on three missions; each in an Orbital Sciences Corporation Cygnus vehicle after it has deberthed from the ISS. Although the experiment will need to meet rigorous safety requirements to ensure the carrier vehicle does not sustain damage, the absence of a crew allows the fire products to be released into the cabin. The tests will be fully automated with the data downlinked at the conclusion of the test before the Cygnus vehicle reenters the

Rencontres de Moriond QCD 2012: Straight to the Top

CERN Multimedia

Katarina Anthony

2012-01-01

Friday’s sessions took a trip into the domain of the Top quark, which was discovered at Fermilab back in early March 1995 and was reported two weeks later at Moriond. The LHC and Tevatron experiments presented the latest measurements of the production of the top quark and its decays. An understanding of the top quark is vital for the verification of the Standard Model as well as a potential window for new physics beyond the Standard Model.   Measurements of the top mass by LHC and Tevatron. Top quark events are background for Higgs searches and hence need to be well understood. Moreover, since it is the heaviest known elementary particle, finding its mass to great precision will help validate the Standard Model Higgs (if it exists). “We want to measure as many of its properties as possible, as precisely as possible,” says Alison Lister, from University of Geneva, who presented some of the LHC experiments’ results at the conference. The LHC experiments...

Review of studies on criticality safety evaluation and criticality experiment methods

International Nuclear Information System (INIS)

Naito, Yoshitaka; Yamamoto, Toshihiro; Misawa, Tsuyoshi; Yamane, Yuichi

2013-01-01

Since the early 1960s, many studies on criticality safety evaluation have been conducted in Japan. Computer code systems were developed initially by employing finite difference methods, and more recently by using Monte Carlo methods. Criticality experiments have also been carried out in many laboratories in Japan as well as overseas. By effectively using these study results, the Japanese Criticality Safety Handbook was published in 1988, almost the intermediate point of the last 50 years. An increased interest has been shown in criticality safety studies, and a Working Party on Nuclear Criticality Safety (WPNCS) was set up by the Nuclear Science Committee of Organisation Economic Co-operation and Development in 1997. WPNCS has several task forces in charge of each of the International Criticality Safety Benchmark Evaluation Program (ICSBEP), Subcritical Measurement, Experimental Needs, Burn-up Credit Studies and Minimum Critical Values. Criticality safety studies in Japan have been carried out in cooperation with WPNCS. This paper describes criticality safety study activities in Japan along with the contents of the Japanese Criticality Safety Handbook and the tasks of WPNCS. (author)

New safety experiments in decommissioned superheated steam reactor at Karlstein

International Nuclear Information System (INIS)

Koerting, K.

1986-01-01

This article gives a concise summary of the Status Report of the Superheated Steam Reactor Safety Program (PHDR) Project, held at KfK on Dec. 5, 1985. The results discussed dealt with fire experiments, shock tests simulating airplane crashes, temperature shocks in the reactor pressure vessel, studies of crack detection in pressure vessels and blasting experiments associated with nuclear plant decommissioning

Review of irradiation experiments for water reactor safety research

International Nuclear Information System (INIS)

Tobioka, Toshiaki

1977-02-01

A review is made of irradiation experiments for water reactor safety research under way in both commercial power plants and test reactors. Such experiments are grouped in two; first, LWR fuel performance under normal and abnormal operating conditions, and second, irradiation effects on fracture toughness in LWR vessels. In the former are fuel densification, swelling, and the influence of power ramp and cycling on fuel rod, and also fuel rod behavior under accident conditions in in-reactor experiment. In the latter are the effects of neutron exposure level on the ferritic steel of pressure vessels, etc.. (auth.)

Study of the top quark electric charge at the cdf experiment

International Nuclear Information System (INIS)

Bartos, P.

2011-01-01

We report on the measurement of the top quark electric charge using the jet charge tagging method on events containing a single lepton collected by the CDF II detector at Fermilab between February 2002 and February 2010 at the center-of-mass energy ps = 1.96 TeV . There are three main components to this measurement: determining the charge of the W (using the charge of the lepton), pairing the W with the b-jet to ensure that they are from the same top decay branch and finally determining the charge of the b-jet using the Jet Charge algorithm. We found, on a sample of 5.6 fb -1 of data, that the p-value under the standard model hypothesis is equal to 13.4%, while the p-value under the exotic model hypothesis is equal to 0.014%. Using the a priori criteria generally accepted by the CDF collaboration, we can say that the result is consistent with the standard model, while we exclude an exotic quark hypothesis with 95% confidence. Using the Bayesian approach, we obtain for the Bayes factor (2 · ln(BF)) a value of 19.6, that favors very strongly the SM hypothesis over the XM one. The presented method has the highest sensitivity to the top quark electric charge among the presented so far top quark charge analysis. (author)

Study of the top quark electric charge at the CDF experiment

Energy Technology Data Exchange (ETDEWEB)

Bartos, Pavol [Comenius Univ., Bratislava (Slovakia)

2011-01-01

We report on the measurement of the top quark electric charge using the jet charge tagging method on events containing a single lepton collected by the CDF II detector at Fermilab between February 2002 and February 2010 at the center-of-mass energy √s = 1.96 TeV. There are three main components to this measurement: determining the charge of the W (using the charge of the lepton), pairing the W with the b-jet to ensure that they are from the same top decay branch and finally determining the charge of the b-jet using the Jet Charge algorithm. We found, on a sample of 5.6 fb^-1 of data, that the p-value under the standard model hypothesis is equal to 13.4%, while the p-value under the exotic model hypothesis is equal to 0.014%. Using the a priori criteria generally accepted by the CDF collaboration, we can say that the result is consistent with the standard model, while we exclude an exotic quark hypothesis with 95% confidence. Using the Bayesian approach, we obtain for the Bayes factor (2ln(BF)) a value of 19.6, that favors very strongly the SM hypothesis over the XM one. The presented method has the highest sensitivity to the top quark electric charge among the presented so far top quark charge analysis.

The Detector Safety System of the ATLAS experiment

International Nuclear Information System (INIS)

Beltramello, O; Burckhart, H J; Franz, S; Jaekel, M; Jeckel, M; Lueders, S; Morpurgo, G; Santos Pedrosa, F dos; Pommes, K; Sandaker, H

2009-01-01

The ATLAS detector at the Large Hadron Collider at CERN is one of the most advanced detectors for High Energy Physics experiments ever built. It consists of the order of ten functionally independent sub-detectors, which all have dedicated services like power, cooling, gas supply. A Detector Safety System has been built to detect possible operational problems and abnormal and potentially dangerous situations at an early stage and, if needed, to bring the relevant part of ATLAS automatically into a safe state. The procedures and the configuration specific to ATLAS are described in detail and first operational experience is given.

Study of different properties of the top-anti-top pairs in the dilepton channel with the D0 and ATLAS detectors

International Nuclear Information System (INIS)

Deterre, C.

2012-01-01

The studies of different properties of the top-anti-top pair in the dilepton final state are presented in this thesis. Two analyses have been performed in different experiments: D0 at the Tevatron and ATLAS at the LHC. Since the two colliders are different, the measurements from these experiments are complementary for studies of the top quark properties. The first analysis, performed at D0, consisted in measuring the top-anti-top production cross-section simultaneously with the branching ratio t → Wb. This measurement was done in the dilepton channel with a sample of data corresponding to an integrated luminosity of 5.4 fb -1 . It has then been combined with the measurement in the semileptonic channel. We obtain a precision of 8% on the cross-section which is comparable to the precision of theoretical predictions. The second analysis, performed in ATLAS, consisted in measuring the top charge asymmetry in the dilepton channel with the full 2011 dataset corresponding to 4.7 fb -1 . The result has been combined with the result for 1 fb -1 of the semileptonic channel. We obtain: A C (tt-bar) = 0.029 ± 0.018 (stat.) ± 0.014 (syst.), which is compatible with the standard model prediction of 0.004 ± 0.001. (author) [fr

Passive safety injection experiments and analyses (PAHKO)

International Nuclear Information System (INIS)

Tuunanen, J.

1998-01-01

PAHKO project involved experiments on the PACTEL facility and computer simulations of selected experiments. The experiments focused on the performance of Passive Safety Injection Systems (PSIS) of Advanced Light Water Reactors (ALWRs) in Small Break Loss-Of-Coolant Accident (SBLOCA) conditions. The PSIS consisted of a Core Make-up Tank (CMT) and two pipelines (Pressure Balancing Line, PBL, and Injection Line, IL). The examined PSIS worked efficiently in SBLOCAs although the flow through the PSIS stopped temporarily if the break was very small and the hot water filled the CMT. The experiments demonstrated the importance of the flow distributor in the CMT to limit rapid condensation. The project included validation of three thermal-hydraulic computer codes (APROS, CATHARE and RELAP5). The analyses showed the codes are capable to simulate the overall behaviour of the transients. The detailed analyses of the results showed some models in the codes still need improvements. Especially, further development of models for thermal stratification, condensation and natural circulation flow with small driving forces would be necessary for accurate simulation of the PSIS phenomena. (orig.)

The safety experience of New Zealand adventure tourism operators.

Science.gov (United States)

Bentley, Tim A; Page, Stephen; Walker, Linda

2004-01-01

This survey examined parameters of the New Zealand adventure tourism industry client injury risk. The research also sought to establish priorities for intervention to reduce adventure tourism risk, and identify client injury control measures currently in place (or absent) in the New Zealand adventure tourism industry, with a view to establishing guidelines for the development of effective adventure tourism safety management systems. This 2003 survey builds upon an exploratory study of New Zealand adventure tourism safety conducted by us during 1999. A postal questionnaire was used to survey all identifiable New Zealand adventure tourism operators. The questionnaire asked respondents about their recorded client injury experience, perceptions of client injury risk factors, safety management practices, and barriers to safety. Some 27 adventure tourism activities were represented among the responding sample (n=96). The highest client injury risk was reported in the snow sports, bungee jumping and horse riding sectors, although serious underreporting of minor injuries was evident across the industry. Slips, trips and falls (STF) were the major client injury mechanisms, and a range of risk factors for client injuries were identified. Safety management measures were inconsistently applied across the industry. The industry should consider the implications of poor injury reporting standards and safety management practices generally. Specifically, the industry should consider risk management that focuses on minor (e.g., STF) as well as catastrophic events.

Analysis of experiments of the University of Hannover with the Cathare code on fluid dynamic effects in the fuel element top nozzle area during refilling and reflooding

International Nuclear Information System (INIS)

Bestion, D.

1989-11-01

The CATHARE code is used to calculate the experiment of the University of Hannover concerning the flooding limit at the fuel element top nozzle area. Some qualitative and quantitativ limit at the fuel element top nozzle area. on both the actual fluid dynamics which is observed in the experiments and on the corresponding code behaviour. Shortcomings of the present models are clearly identified. New developments are proposed which should extend the code capabilities

Top-quark mass measurements: Alternative techniques (LHC + Tevatron)

CERN Document Server

Adomeit, Stefanie; The ATLAS collaboration

2014-01-01

Measurements of the top-quark mass employing alternative techniques are presented, performed by the D0 and CDF collaborations at the Tevatron as well as the ATLAS and CMS experiments at the LHC. The alternative methods presented include measurements using the lifetime of $B$-hadrons, the transverse momentum of charged leptons and the endpoints of kinematic distributions in top quark anti-quark pair ($t\\bar{t}$) final states. The extraction of the top-quark pole mass from the $t\\bar{t}$ production cross-section and the normalized differential $t\\bar{t}$ + 1-jet cross-section are discussed as well as the top-quark mass extraction using fixed-order QCD predictions at detector level. Finally, a measurement of the top-quark mass using events enhanced in single top t-channel production is presented.

Ekspedeerimisfirmade TOP

Index Scriptorium Estoniae

2008-01-01

Ekspedeerimisfirmade TOP 57. Vt. samas: Tanel Raig. Majandus kukutab ekspedeerimisturgu. Diagramm: Väliskaubanduse statistika; Katrin Raie. Ekspedeerijad hakkavad rohkem koostööle rõhuma. Kommenteerib Jaan Lepp; Müügitulu TOP 10; Müügitulu kasvu TOP 10; Kasumi TOP 10; Kasumi kasvu TOP 10; Rentaabluse TOP 10; Omakapitali tootlikkuse TOP 10; Eestis registreeritud Vene hiiglane; Ekspedeerimisturu kasumiliider kaotas 20 miljonit; Küsimustele vastab OÜ Contimer juht Dmitri Redkin

Transient behaviour and inherent safety research of LMFBR power plants

International Nuclear Information System (INIS)

Zhu Jizhou; Wang Ping; Yu Baoan

1995-06-01

Fast Breeder Reactor will be the next generation reactor for nuclear electricity production, the development of FBR will give the profits of efficient utilization of nuclear resources. The fast reactor safety analysis is the foundation and key of FBR research work. Therefore, a block-oriented mathematical model for the primary system of LMFBRs was constructed, and the dynamic simulating results which have been carried out on micro-computer are presented for various transients, i.e. TOP, LOFS, LOHS. The results agree well with the corresponding results of the code NATDEMO and experiment results of EBR-II. Based on previous analysis, various methods are discussed to confirm the inherent safety of LMFBR

Approximate spatio-temporal top-k publish/subscribe

KAUST Repository

Chen, Lisi

2018-04-26

Location-based publish/subscribe plays a significant role in mobile information disseminations. In this light, we propose and study a novel problem of processing location-based top-k subscriptions over spatio-temporal data streams. We define a new type of approximate location-based top-k subscription, Approximate Temporal Spatial-Keyword Top-k (ATSK) Subscription, that continuously feeds users with relevant spatio-temporal messages by considering textual similarity, spatial proximity, and information freshness. Different from existing location-based top-k subscriptions, Approximate Temporal Spatial-Keyword Top-k (ATSK) Subscription can automatically adjust the triggering condition by taking the triggering score of other subscriptions into account. The group filtering efficacy can be substantially improved by sacrificing the publishing result quality with a bounded guarantee. We conduct extensive experiments on two real datasets to demonstrate the performance of the developed solutions.

Approximate spatio-temporal top-k publish/subscribe

KAUST Repository

Chen, Lisi; Shang, Shuo

2018-01-01

Location-based publish/subscribe plays a significant role in mobile information disseminations. In this light, we propose and study a novel problem of processing location-based top-k subscriptions over spatio-temporal data streams. We define a new type of approximate location-based top-k subscription, Approximate Temporal Spatial-Keyword Top-k (ATSK) Subscription, that continuously feeds users with relevant spatio-temporal messages by considering textual similarity, spatial proximity, and information freshness. Different from existing location-based top-k subscriptions, Approximate Temporal Spatial-Keyword Top-k (ATSK) Subscription can automatically adjust the triggering condition by taking the triggering score of other subscriptions into account. The group filtering efficacy can be substantially improved by sacrificing the publishing result quality with a bounded guarantee. We conduct extensive experiments on two real datasets to demonstrate the performance of the developed solutions.

Investigating the experiences of New Zealand MRI technologists: Exploring intra-orbital metallic foreign body safety practices

Energy Technology Data Exchange (ETDEWEB)

Jacobs, Philippa K [River Radiology, Victoria Clinic, 750 Victoria Street, Hamilton, Waikato (New Zealand); Henwood, Suzanne [Unitec - Medical Imaging, Unitec Ratanui Street Henderson, Auckland (New Zealand); River Radiology, Victoria Clinic, 750 Victoria Street, Hamilton, Waikato (New Zealand)

2013-12-15

Qualitative research is lacking regarding the experiences of magnetic resonance imaging (MRI) technologists and their involvement in workplace safety practices. This article provides a gateway to explore, describe and document experiences of MRI technologists in New Zealand (NZ) pertaining to intra-orbital metallic foreign body (IMFB) safety practices. This phenomenological study describes the experiences of seven MRI technologists all with a minimum of 5 years' NZ work experience in MRI. The MRI technologists were interviewed face-to-face regarding their professional IMFB workplace experiences in order to explore historical, current and potential issues. Findings demonstrated that aspects of organization and administration are fundamentally important to MRI technologists. Varying levels of education and knowledge, as well as experience and skills gained, have significantly impacted on MRI technologists’ level of confidence and control in IMFB practices. Participants’ descriptions of their experiences in practice regarding decision-making capabilities further highlight the complexity of these themes. A model was developed to demonstrate the interrelated nature of the themes and the complexity of the situation in totality. Findings of this study have provided insight into the experiences of MRI technologists pertaining to IMFB safety practices and highlighted inconsistencies. It is hoped that these findings will contribute to and improve the level of understanding of MRI technologists and the practices and protocols involved in IMFB safety screening. The scarcity of available literature regarding IMFB safety practices highlights that more research is required to investigate additional aspects that could improve MRI technologists’ experiences.

Investigating the experiences of New Zealand MRI technologists: Exploring intra-orbital metallic foreign body safety practices

International Nuclear Information System (INIS)

Jacobs, Philippa K; Henwood, Suzanne

2013-01-01

Qualitative research is lacking regarding the experiences of magnetic resonance imaging (MRI) technologists and their involvement in workplace safety practices. This article provides a gateway to explore, describe and document experiences of MRI technologists in New Zealand (NZ) pertaining to intra-orbital metallic foreign body (IMFB) safety practices. This phenomenological study describes the experiences of seven MRI technologists all with a minimum of 5 years' NZ work experience in MRI. The MRI technologists were interviewed face-to-face regarding their professional IMFB workplace experiences in order to explore historical, current and potential issues. Findings demonstrated that aspects of organization and administration are fundamentally important to MRI technologists. Varying levels of education and knowledge, as well as experience and skills gained, have significantly impacted on MRI technologists’ level of confidence and control in IMFB practices. Participants’ descriptions of their experiences in practice regarding decision-making capabilities further highlight the complexity of these themes. A model was developed to demonstrate the interrelated nature of the themes and the complexity of the situation in totality. Findings of this study have provided insight into the experiences of MRI technologists pertaining to IMFB safety practices and highlighted inconsistencies. It is hoped that these findings will contribute to and improve the level of understanding of MRI technologists and the practices and protocols involved in IMFB safety screening. The scarcity of available literature regarding IMFB safety practices highlights that more research is required to investigate additional aspects that could improve MRI technologists’ experiences

Experience with performance based training of nuclear criticality safety engineers

International Nuclear Information System (INIS)

Taylor, R.G.

1993-01-01

Historically, new entrants to the practice of nuclear criticality safety have learned their job primarily by on-the-job training (OJT) often by association with an experienced nuclear criticality safety engineer who probably also learned their job by OJT. Typically, the new entrant learned what he/she needed to know to solve a particular problem and accumulated experience as more problems were solved. It is likely that more formalism will be required in the future. Current US Department of Energy requirements for those positions which have to demonstrate qualification indicate that it should be achieved by using a systematic approach such as performance based training (PBT). Assuming that PBT would be an acceptable mechanism for nuclear criticality safety engineer training in a more formal environment, a site-specific analysis of the nuclear criticality safety engineer job was performed. Based on this analysis, classes are being developed and delivered to a target audience of newer nuclear criticality safety engineers. Because current interest is in developing training for selected aspects of the nuclear criticality safety engineer job, the analysis i's incompletely developed in some areas. Details of this analysis are provided in this report

Nurses' experiences and perspectives on medication safety practices: an explorative qualitative study

NARCIS (Netherlands)

Smeulers, Marian; Onderwater, Astrid T.; van Zwieten, Myra C. B.; Vermeulen, Hester

2014-01-01

To explore nurses' experiences with and perspectives on preventing medication administration errors. Insight into nurses' experiences with and perspectives on preventing medication administration errors is important and can be utilised to tailor and implement safety practices. A qualitative

Performances of photodiode detectors for top and bottom counting detectors of ISS-CREAM experiment

International Nuclear Information System (INIS)

Hyun, H.J.; Anderson, T.; Angelaszek, D.; Baek, S.J.; Copley, M.; Coutu, S.; Han, J.H.; Huh, H.G.; Hwang, Y.S.; Im, S.; Jeon, H.B.; Kah, D.H.; Kang, K.H.; Kim, H.J.; Kim, K.C.; Kwashnak, K.; Lee, J.; Lee, M.H.; Link, J.T.; Lutz, L.

2015-01-01

The Cosmic Ray Energetics and Mass (CREAM) experiment at the International Space Station (ISS) aims to elucidate the source and acceleration mechanisms of high-energy cosmic rays by measuring the energy spectra from protons to iron. The instrument is planned for launch in 2015 at the ISS, and it comprises a silicon charge detector, a carbon target, top and bottom counting detectors, a calorimeter, and a boronated scintillator detector. The top and bottom counting detectors are developed for separating the electrons from the protons, and each of them comprises a plastic scintillator and a 20×20 silicon photodiode array. Each photodiode is 2.3 cm×2.3 cm in size and exhibits good electrical characteristics. The leakage current is measured to be less than 20 nA/cm 2 at an operating voltage. The signal-to-noise ratio is measured to be better than 70 using commercial electronics, and the radiation hardness is tested using a proton beam. A signal from the photodiode is amplified by VLSI (very-large-scale integration) charge amp/hold circuits, the VA-TA viking chip. Environmental tests are performed using whole assembled photodiode detectors of a flight version. Herein, we present the characteristics of the developed photodiode along with the results of the environmental tests

Performances of photodiode detectors for top and bottom counting detectors of ISS-CREAM experiment

Energy Technology Data Exchange (ETDEWEB)

Hyun, H.J. [Kyungpook National University, Daegu 702-701 (Korea, Republic of); Anderson, T. [Pennsylvania State University, University Park, PA 16802 (United States); Angelaszek, D. [University of Maryland, College Park, MD 20740 (United States); Baek, S.J. [Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Copley, M. [University of Maryland, College Park, MD 20740 (United States); Coutu, S. [Pennsylvania State University, University Park, PA 16802 (United States); Han, J.H.; Huh, H.G. [University of Maryland, College Park, MD 20740 (United States); Hwang, Y.S. [Kyungpook National University, Daegu 702-701 (Korea, Republic of); Im, S. [Pennsylvania State University, University Park, PA 16802 (United States); Jeon, H.B.; Kah, D.H.; Kang, K.H.; Kim, H.J. [Kyungpook National University, Daegu 702-701 (Korea, Republic of); Kim, K.C.; Kwashnak, K. [University of Maryland, College Park, MD 20740 (United States); Lee, J. [Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Lee, M.H. [University of Maryland, College Park, MD 20740 (United States); Link, J.T. [NASA GSFC, Greenbelt, MD 20771 (United States); CRESST(USRA), Columbia, MD 21044 (United States); Lutz, L. [University of Maryland, College Park, MD 20740 (United States); and others

2015-07-01

The Cosmic Ray Energetics and Mass (CREAM) experiment at the International Space Station (ISS) aims to elucidate the source and acceleration mechanisms of high-energy cosmic rays by measuring the energy spectra from protons to iron. The instrument is planned for launch in 2015 at the ISS, and it comprises a silicon charge detector, a carbon target, top and bottom counting detectors, a calorimeter, and a boronated scintillator detector. The top and bottom counting detectors are developed for separating the electrons from the protons, and each of them comprises a plastic scintillator and a 20×20 silicon photodiode array. Each photodiode is 2.3 cm×2.3 cm in size and exhibits good electrical characteristics. The leakage current is measured to be less than 20 nA/cm{sup 2} at an operating voltage. The signal-to-noise ratio is measured to be better than 70 using commercial electronics, and the radiation hardness is tested using a proton beam. A signal from the photodiode is amplified by VLSI (very-large-scale integration) charge amp/hold circuits, the VA-TA viking chip. Environmental tests are performed using whole assembled photodiode detectors of a flight version. Herein, we present the characteristics of the developed photodiode along with the results of the environmental tests.

The Advance Experience of Foreign Top-level Think Tanks and its Enlightment to the Construction of Chinese University Think-Tank

Directory of Open Access Journals (Sweden)

Tao Yong

2016-01-01

Full Text Available This paper expounds the development course and current situation of foreign top-level Think Tank, and analyzes the important effects of foreign colleges and universities Think Tank in supporting national scientific decision-making and rapid development. It analyzes the development course and advanced experience of top-level Think Tank in America and other countries. The paper summaries the advance experiences, combines with the background and features of Think Tank construction of colleges and universities in China. It puts forward that Chinese colleges and universities Think Tank should aim at the national strategic needs, play the advantages of talents gathering and main innovation force, insist on opening, and set constructing professional colleges and universities Think Tank as the breakthrough point. The think tanks produce strategic consulting research results with high quality. The paper proposes the reference effect of foreign Think Tank on characteristic Think Tank construction of colleges and universities in China and the development strategy recommendations.

The detector safety system for LHC experiments

CERN Document Server

Schmeling, Sascha; Lüders, S; Morpurgo, Giulio

2004-01-01

The Detector Safety System (DSS), currently being developed at CERN under the auspices of the Joint Controls Project (JCOP), will be responsible for assuring the protection of equipment for the four Large Hadron Collider (LHC)**1 experiments. Thus, the DSS will require a high degree of both availability and reliability. After evaluation of various possible solutions, a prototype is being built based on a redundant Siemens PLC**2 front-end, to which the safety- critical part of the DSS task is delegated. This is then supervised by a PVSS**3 SCADA**4 system via an OPC**5 server. The PLC front-end is capable of running autonomously and of automatically taking predefined protective actions whenever required. The supervisory layer provides the operator with a status display and with limited online reconfiguration capabilities. Configuration of the code running in the PLCs will be completely data driven via the contents of a "configuration database." Thus, the DSS can easily adapt to the different and constantly ev...

To improve nuclear plant safety by learning from accident's experience

International Nuclear Information System (INIS)

Matsumoto, Hidezo; Kida, Masanori; Kato, Hiroyuki; Hara, Shin-ichi

1994-01-01

The ultimate goal of this study is to produce an expert system that enables the experience (records and information) gained from accidents to be put to use towards improving nuclear plant safety. A number of examples have been investigated, both domestic and overseas, in which experience gained from accidents was utilized by utilities in managing and operating their nuclear power stations to improve safety. The result of investigation has been used to create a general 'basic flow' to make the best use of experience. The ultimate goal is achieved by carrying out this 'basic flow' with artificial intelligence (AI). To do this, it is necessary (1) to apply language analysis to process the source information (primary data base; domestic and overseas accident's reports) into the secondary data base, and (2) to establish an expert system for selecting (screening) significant events from the secondary data base. In the processing described in item (1), a multi-lingual thesaurus for nuclear-related terms become necessary because the source information (primary data bases) itself is multi-lingual. In the work described in item (2), the utilization of probabilistic safety assessment (PSA), for example, is a candidate method for judging the significance of events. Achieving the goal thus requires developing various new techniques. As the first step of the above long-term study project, this report proposes the 'basic flow' and presents the concept of how the nuclear-related AI can be used to carry out this 'basic flow'. (author)

Application of the Dragon reactor experiment to the safety evaluation of current HTR systems

International Nuclear Information System (INIS)

Ashworth, F.P.O.; Faircloth, R.L.

1976-01-01

An important component of the confidence required for the safety assessment of high-temperature reactors is the experimental proof of phenomena such as fission product release or core corrosion. The most convincing experiments are those carried out in a reactor. This paper outlines the scope of experiments relevant to safety which can be done in the Dragon Reactor Experiment and describes as an example the experimental campaign and the current outcome of the work on validating the predictions of caesium release and migration. (author)

The French nuclear safety authority's experience with radioactive transport inspection

International Nuclear Information System (INIS)

Jacob, E.; Aguilar, J.

2004-01-01

About 300,000 radioactive material packages are transported annually in France. Most consist of radioisotopes for medical, pharmaceutical or industrial use. On the other hand, the nuclear industry deals with the transport of fuel cycle materials (uranium, fuel assemblies, etc.) and waste from power plants, reprocessing plants and research centers. France is also a transit country for shipments such as spent fuel packages from Switzerland or Germany, which are bound for Sellafield in Great Britain. The French nuclear safety authority (DGSNR: Directorate General for Nuclear Safety and Radioprotection) has been responsible since 1997 for the safety of radioactive material transport. This paper presents DGNSR's experience with transport inspection: a feedback of key points based on 300 inspections achieved during the past five years is given

A novel approach to precision measurements of the top quark-antiquark pair production cross section with the ATLAS experiment

International Nuclear Information System (INIS)

Lange, Clemens Gregor

2013-01-01

This doctoral thesis presents three measurements of the top quark-antiquark pair production cross section in proton-proton collisions at a centre-of-mass energy of √(s)=7 TeV recorded in 2010 and 2011 with the ATLAS Experiment at the Large Hadron Collider. Events are selected in the single lepton topology by requiring an electron or muon, large missing transverse momentum and at least three jets. While one analysis relies on kinematic information only to discriminate the top quark-antiquark pair signal from the background processes, the other two also make use of b-tagging information. With the help of multivariate methods the most precise measurements in this topology are obtained. This is for two of the measurements in particular possible due to the use of a profile likelihood method which is studied in detail. For the first time a fiducial inclusive cross section measurement for top quark events is performed allowing a measurement almost independent of theoretical uncertainties. All measurements are in agreement with theory predictions performed in perturbation theory at approximate NNLO.

TopView - ATLAS top physics analysis package

CERN Document Server

Shibata, A

2007-01-01

TopView is a common analysis package which is widely used in the ATLAS top physics working group. The package is fully based on the official ATLAS software Athena and EventView and playing a central role in the collaborative analysis model. It is a functional package which accounts for a broad range issues in implementing physics analysis. As well as being a modular framework suitable as a common workplace for collaborators, TopView implements numerous analysis tools including a complete top-antitop reconstruction and single top reconstruction. The package is currently used to produce common ntuple from Monte Carlo production and future use cases are under rapid development. In this paper, the design and ideas behind TopView and the performance of the analyses implemented in the package are presented with detailed documentation of the contents and instruction for using the package.

Search for Single Top Quark Production at HERA

CERN Document Server

Aaron, F D; Alexa, C; Alimujiang, K; Andreev, V; Antunovic, B; Asmone, A; Backovic, S; Baghdasaryan, A; Barrelet, E; Bartel, W; Begzsuren, K; Belousov, A; Bizot, J C; Boudry, V; Bozovic-Jelisavcic, I; Bracinik, J; Brandt, G; Brinkmann, M; Brisson, V; Bruncko, D; Bunyatyan, A; Buschhorn, G; Bystritskaya, L; Campbell, A J; Cantun Avila, K B; Cassol-Brunner, F; Cerny, K; Cerny, V; Chekelian, V; Cholewa, A; Contreras, J G; Coughlan, J A; Cozzika, G; Cvach, J; Dainton, J B; Daum, K; Deak, M; de Boer, Y; Delcourt, B; Del Degan, M; Delvax, J; De Roeck, A; De Wolf, E A; Diaconu, C; Dodonov, V; Dossanov, A; Dubak, A; Eckerlin, G; Efremenko, V; Egli, S; Eliseev, A; Elsen, E; Falkiewicz, A; Favart, L; Fedotov, A; Felst, R; Feltesse, J; Ferencei, J; Fischer, D J; Fleischer, M; Fomenko, A; Gabathuler, E; Gayler, J; Ghazaryan, S; Glazov, A; Glushkov, I; Goerlich, L; Gogitidze, N; Gouzevitch, M; Grab, C; Greenshaw, T; Grell, B R; Grindhammer, G; Habib, S; Haidt, D; Helebrant, C; Henderson, R C W; Hennekemper, E; Henschel, H; Herbst, M; Herrera, G; Hildebrandt, M; Hiller, K H; Hoffmann, D; Horisberger, R; Hreus, T; Jacquet, M; Janssen, M E; Janssen, X; Jonsson, L; Jung, Andreas Werner; Jung, H; Kapichine, M; Katzy, J; Kenyon, I R; Kiesling, C; Klein, M; Kleinwort, C; Kluge, T; Knutsson, A; Kogler, R; Kostka, P; Kraemer, M; Krastev, K; Kretzschmar, J; Kropivnitskaya, A; Kruger, K; Kutak, K; Landon, M P J; Lange, W; Lastovicka-Medin, G; Laycock, P; Lebedev, A; Leibenguth, G; Lendermann, V; Levonian, S; Li, G; Lipka, K; Liptaj, A; List, B; List, J; Loktionova, N; Lopez-Fernandez, R; Lubimov, V; Lytkin, L; Makankine, A; Malinovski, E; Marage, P; Marti, Ll; Martyn, H U.; Maxfield, S J; Mehta, A; Meyer, A B; Meyer, H; Meyer, H; Meyer, J; Michels, V; Mikocki, S; Milcewicz-Mika, I; Moreau, F; Morozov, A; Morris, J V; Mozer, Matthias Ulrich; Mudrinic, M; Muller, K; Murin, P; Naumann, Th; Newman, P R; Niebuhr, C; Nikiforov, A; Nowak, G; Nowak, K; Nozicka, M; Olivier, B; Olsson, J E; Osman, S; Ozerov, D; Palichik, V; Panagoulias, I; Pandurovic, M; Papadopoulou, Th; Pascaud, C; Patel, G D; Pejchal, O; Perez, E; Petrukhin, A; Picuric, I; Piec, S; Pitzl, D; Placakyte, R; Pokorny, B; Polifka, R; Povh, B; Preda, T; Radescu, V; Rahmat, A J; Raicevic, N; Raspiareza, A; Ravdandorj, T; Reimer, P; Rizvi, E; Robmann, P; Roland, B; Roosen, R; Rostovtsev, A; Rotaru, M; Ruiz Tabasco, J E; Rurikova, Z; Rusakov, S; Salek, D; Sankey, D P C; Sauter, M; Sauvan, E; Schmitt, S; Schmitz, C; Schoeffel, L; Schoning, A; Schultz-Coulon, H C; Sefkow, F; Shaw-West, R N; Shtarkov, L N; Shushkevich, S; Sloan, T; Smiljanic, Ivan; Soloviev, Y; Sopicki, P; South, D; Spaskov, V; Specka, Arnd E; Staykova, Z; Steder, M; Stella, B; Stoicea, G; Straumann, U.; Sunar, D; Sykora, T; Tchoulakov, V; Thompson, G; Thompson, P D; Toll, T; Tomasz, F; Tran, T H; Traynor, D; Trinh, T N; Truol, P; Tsakov, I; Tseepeldorj, B; Turnau, J; Urban, K; Valkarova, A; Vallee, C; Van Mechelen, P; Vargas Trevino, A; Vazdik, Y; Vinokurova, S; Volchinski, V; von den Driesch, M; Wegener, D; Wissing, Ch; Wunsch, E; Zacek, J; Zalesak, J; Zhang, Z; Zhokin, A; Zimmermann, T; Zohrabyan, H; Zomer, F; Zus, R

2009-01-01

A search for single top quark production is performed in the full ep data sample collected by the H1 experiment at HERA, corresponding to an integrated luminosity of 474 pb^-1. Decays of top quarks into a b quark and a W boson with subsequent leptonic or hadronic decay of the W are investigated. A multivariate analysis is performed to discriminate top quark production from Standard Model background processes. An upper limit on the top quark production cross section via flavour changing neutral current processes sigma (ep -> etX) < 0.25 pb is established at 95% CL. Limits on the anomalous coupling kappa_{tu gamma} are derived.

UK experience of safety requirements for thermal reactor stations

International Nuclear Information System (INIS)

Matthews, R.R.; Dale, G.C.; Tweedy, J.N.

1977-01-01

The paper summarises the development of safety requirements since the first of the Generating Boards' Magnox reactors commenced operation in 1962 and includes A.G.R. safety together with the preparation of S.G.H.W.R. design safety criteria. It outlines the basic principles originally adopted and shows how safety assessment is a continuing process throughout the life of a reactor. Some description is given of the continuous effort over the years to obtain increased safety margins for existing and new reactors, taking into account the construction and operating experience, experimental information, and more sophisticated computer-aided design techniques which have become available. The main safeguards against risks arising from the Generating Boards' reactors are the achievement of high standards of design, construction and operation, in conjunction with comprehensive fault analyses to ensure that adequate protective equipment is provided. The most important analyses refer to faults which can lead to excessive fuel element temperatures arising from an increase in power or a reduction in cooling capacity. They include the possibility of unintended control rod withdrawal at power or at start-up, coolant flow failure, pressure circuit failure, loss of boiler feed water, and failure of electric power. The paper reviews the protective equipment, and the policy for reactor safety assessments which include application of maximum credible accident philosophy and later the limited use of reliability and probability methods. Some of the Generating Boards' reactors are now more than half way through their planned working lives and during this time safety protective equipment has occasionally been brought into operation, often for spurious reasons. The general performance, of safety equipment is reviewed particularly for incidents such as main turbo-alternator trip, circulator failure, fuel element failures and other similar events, and some problems which have given rise to

Safety research experiment facilities, Idaho National Engineering Laboratory, Idaho. Final environmental impact statement

International Nuclear Information System (INIS)

Liverman, J.L.

1977-09-01

This environmental statement was prepared for the Safety Research Experiment Facilities (SAREF) Project. The purpose of the proposed project is to modify some existing facilities and provide a new test facility at the Idaho National Engineering Laboratory (INEL) for conducting fast breeder reactor (FBR) safety experiments. The SAREF Project proposal has been developed after an extensive study which identified the FBR safety research needs requiring in-reactor experiments and which evaluated the capability of various existing and new facilities to meet these needs. The proposed facilities provide for the in-reactor testing of large bundles of prototypical FBR fuel elements under a wide variety of conditions, ranging from those abnormal operating conditions which might be expected to occur during the life of an FBR power plant to the extremely low probability, hypothetical accidents used in the evaluation of some design options and in the assessment of the long-term potential risk associated with wide-acale deployment of the FBR

Recommended nuclear criticality safety experiments in support of the safe transportation of fissile material

International Nuclear Information System (INIS)

Tollefson, D.A.; Elliott, E.P.; Dyer, H.R.; Thompson, S.A.

1993-01-01

Validation of computer codes and nuclear data (cross-section) libraries using benchmark quality critical (or certain subcritical) experiments is an essential part of a nuclear criticality safety evaluation. The validation results establish the credibility of the calculational tools for use in evaluating a particular application. Validation of the calculational tools is addressed in several American National Standards Institute/American Nuclear Society (ANSI/ANS) standards, with ANSI/ANS-8.1 being the most relevant. Documentation of the validation is a required part of all safety analyses involving significant quantities of fissile materials. In the case of transportation of fissile materials, the safety analysis report for packaging (SARP) must contain a thorough discussion of benchmark experiments, detailing how the experiments relate to the significant packaging and contents materials (fissile, moderating, neutron absorbing) within the package. The experiments recommended in this paper are needed to address certain areas related to transportation of unirradiated fissile materials in drum-type containers (packagings) for which current data are inadequate or are lacking

Kinnisvarafirmade TOP 90

Index Scriptorium Estoniae

2002-01-01

TOP 90. Kinnisvara valdkondade TOP 5. Käibe TOP 30. Käibe kasvu TOP 30. Rentaabluse TOP 30. Kasumi TOP 30. Kasumi kasvu TOP 30. Varade tootlikkuse TOP 30. Kinnisvarafirmade üldandmed. Kinnisvarafirmade finantsandmed

Assessing progress in the development of safety culture

International Nuclear Information System (INIS)

Rotaru, Ioan; Ghita, Sorin

1999-01-01

visible prescriptive formula for developing a strong safety culture. However, a prerequisite is genuine and consistent commitment by the top management of an organization to improving safety . Providing this commitment exists, the best recommendation is to due something tangible and visible to improve safety, preferably involving employees from the outset. The choice of practices for developing an improved safety culture should take account of the existing national and organizational culture in order to ensure effective implementation. The importance of the learning process has been emphasized. A mechanism is necessary to ensure that international experience of practices to develop a strong safety culture is shared on a regular and frequent basis. The maintenance and improvement of a safety culture is a process of continuous evolution. Indicators are available to assess positive progress in this evolution and to detect a weakening safety culture. (authors)

New safety performance indicators for safety assessment of radioactive waste disposal facilities. Cuban experience

International Nuclear Information System (INIS)

Peralta Vital, J.L.; Castillo, R.G.; Olivera, J.

2002-01-01

The paper shows the Cuban experience on implementing geological disposal of radioactive waste and the necessity for identifying new safety performance indicators for the safety assessment (SA) of radioactive waste disposal facilities. The selected indicator was the concentration of natural radioactive elements (U, Ra, Th, K) in the Cuban geologic environment. We have carried out a group of investigations, which have allowed characterising the concentration for the whole Country, creating a wide database where this indicator is associated with the lithology. The main lithologies in Cuba are: the sedimentary rocks (70 percent of national occurrence), which are present in the three regions (limestone and lutite), and finally the igneous and metamorphic rocks. The results show the concentrations ranges of the natural radionuclides associated fundamentally to the variation in the lithology and geographical area of the Country. In Cuba, the higher concentration (ppm) of Uranium and Radium are referenced to the Central region associated to Skarn, while for Thorium (ppm) and Potassium (%), in the East region the concentration peaks in Tuffs have been found. The concentrations ranges obtained are preliminary, they characterise the behaviour of this parameter for the Cuban geology, but they do not represent limits for safety assessment purposes yet. Also other factors should be taken into account as the assessment context, time scales and others assumptions before establishing the final concentration limits for the natural radionuclides as a radiological and nuclear safety performance indicator complementary to dose and risk for safety assessment for radiological and nuclear facilities. (author)

Enhancing operational nuclear safety

International Nuclear Information System (INIS)

Sengoku, Katsuhisa

2008-01-01

Since Chernobyl, the dictum A n accident anywhere is an accident everywhere i s a globally shared perception. The paper presents challenges to the international nuclear community: globalization, sustainable and dynamic development, secure, safe and clean energy supply, nuclear r enaissance , public concern for nuclear safety, nuclear security, and technology and management. Strong national safety infrastructures and international cooperation are required to maintain a high level of nuclear safety and security worldwide. There is an increasing number of countries thinking of going nuclear: Morocco, Indonesia, Iran, Poland, Turkey, Bangladesh, Egypt, Vietnam, Chile, Nigeria, Malaysia, Thailand, Uruguay, Tunisia, Algeria. Another serious incident will jeopardize the prospect of nuclear renaissance. Safety and security are preconditions for countries newly introducing NPP as well as for those with mature nuclear programmes. The Global Nuclear Safety Regime (GNSR) is referred to as the institutional, legal and technical framework to achieve worldwide implementation of the safety of nuclear installations. At the top of the framework is the Convention on Nuclear Safety which covers the nuclear power plants. The convention has 56 contracting parties which meet triennially where national reports are presented and subject to the review of peers. The International Atomic Energy Agency (IAEA) undertakes a programme to foster the GNSR through the establishment of IAEA safety standards and related publications. The programme provides for the application of standards for the (1) safety of nuclear installations, (2) safety of radioactive sources, (3) safe transport of radioactive material and (4) management of radioactive waste. It also provides for the security of nuclear installations, nuclear material and radioactive material. The safety standards hierarchy is as follows: safety fundamental, safety requirements and safety guides. The safety fundamentals are the bases for IAEA

Kinnisvarafirmade TOP 90

Index Scriptorium Estoniae

2003-01-01

Kinnisvarafirmade TOP 90. Rentaabluse TOP 30. Käibe TOP 30. Käibe kasvu TOP 30. Kasumi TOP 30. Kasumi kasvu TOP 30. Varade tootlikkuse TOP 30. Kinnisvarafirmade üldandmed. Kinnisvarafirmade finantsandmed

Teedeehitusfirmade TOP 24

Index Scriptorium Estoniae

2006-01-01

Teedeehitusfirmade TOP. Vt. samas: Käibe TOP 10; Käibe kasvu TOP 10; Kasumi TOP 10; Kasumi Kasvu TOP 10; Rentaabluse TOP 10; Omakapitali tootlikkuse TOP 10; Teedeehitusfirmade üld- ja finantsandmed

Ehitusmaterjalitootjate TOP 95

Index Scriptorium Estoniae

2006-01-01

Ehitusmaterjalitootjate TOP. Vt. samas: Käibe TOP 10; Käibe kasvu TOP 10; Kasumi TOP 10; Kasumi kasvu TOP 10; Rentaabluse TOP 10; Omakapitali tootlikkuse TOP 10; Ehitusmaterjalitootjate üld- ja finantsandmed

Planning the Unplanned Experiment: Towards Assessing the Efficacy of Standards for Safety-Critical Software

Science.gov (United States)

Graydon, Patrick J.; Holloway, C. M.

2015-01-01

Safe use of software in safety-critical applications requires well-founded means of determining whether software is fit for such use. While software in industries such as aviation has a good safety record, little is known about whether standards for software in safety-critical applications 'work' (or even what that means). It is often (implicitly) argued that software is fit for safety-critical use because it conforms to an appropriate standard. Without knowing whether a standard works, such reliance is an experiment; without carefully collecting assessment data, that experiment is unplanned. To help plan the experiment, we organized a workshop to develop practical ideas for assessing software safety standards. In this paper, we relate and elaborate on the workshop discussion, which revealed subtle but important study design considerations and practical barriers to collecting appropriate historical data and recruiting appropriate experimental subjects. We discuss assessing standards as written and as applied, several candidate definitions for what it means for a standard to 'work,' and key assessment strategies and study techniques and the pros and cons of each. Finally, we conclude with thoughts about the kinds of research that will be required and how academia, industry, and regulators might collaborate to overcome the noted barriers.

Safety Research Experiment Facilities, Idaho National Engineering Laboratory, Idaho. Draft environmental statement

International Nuclear Information System (INIS)

1977-01-01

This environmental statement was prepared in accordance with the National Environmental Policy Act of 1969 (NEPA) in support of the Energy Research and Development Administration's (ERDA) proposal for legislative authorization and appropriations for the Safety Research Experiment Facilities (SAREF) Project. The purpose of the proposed project is to modify some existing facilities and provide a new test facility at the Idaho National Engineering Laboratory (INEL) for conducting fast breeder reactor (FBR) safety experiments. The SAREF Project proposal has been developed after an extensive study which identified the FBR safety research needs requiring in-reactor experiments and which evaluated the capability of various existing and new facilities to meet these needs. The proposed facilities provide for the in-reactor testing of large bundles of prototypical FBR fuel elements under a wide variety of conditions, ranging from those abnormal operating conditions which might be expected to occur during the life of an FBR power plant to the extremely low probability, hypothetical accidents used in the evalution of some design options and in the assessment of the long-term potential risk associated with wide-scale deployment of the FBR

Search for heavy resonances decaying to top quarks

CERN Document Server

D'Auria, Saverio; The ATLAS collaboration

2017-01-01

Searches for new resonances that decay either to pairs of top quarks or a top and a b-quark are presented. The searches are performed with the ATLAS experiment at the LHC using proton-proton collision data. The invariant mass spectrum of hypothetical resonances are examined for local excesses or deficits that are inconsistent with the Standard Model prediction.

NSPWG-recommended safety requirements and guidelines for SEI nuclear propulsion

International Nuclear Information System (INIS)

Marshall, A.C.; Lee, J.H.; McCulloch, W.H.; Sawyer, J.C. Jr.; Bari, R.A.; Brown, N.W.; Cullingford, H.S.; Hardy, A.C.; Remp, K.; Sholtis, J.A.

1992-01-01

An Interagency Nuclear Safety Policy Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program to facilitate the implementation of mission planning and conceptual design studies. The NSPWG developed a top- level policy to provide the guiding principles for the development and implementation of the nuclear propulsion safety program and the development of Safety Functional Requirements. In addition the NSPWG reviewed safety issues for nuclear propulsion and recommended top-level safety requirements and guidelines to address these issues. Safety requirements were developed for reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, and safeguards. Guidelines were recommended for risk/reliability, operational safety, flight trajectory and mission abort, space debris and meteoroids, and ground test safety. In this paper the specific requirements and guidelines will be discussed

Koolitusfirmade TOP 50

Index Scriptorium Estoniae

2006-01-01

Koolitusfirmade TOP. Vt. samas: Käibe TOP 10; Käibe kasvu TOP 10; Majandustegevuse kasumi TOP 10; Kasumi kasvu TOP 10; Rentaabluse TOP 10; Omakapitali tootlikkuse TOP 10; Koolitusfirmade üld- ja finantsandmed

Põllumajandustootjate TOP 50

Index Scriptorium Estoniae

2006-01-01

Põllumajandustootjate TOP. Vt. samas: Käibe TOP 10; Käibe kasvu TOP 10; Majandustegevuse kasumi TOP 10; Kasumi kasvu TOP 10; Rentaabluse TOP 10; Omakapitali tootlikkuse TOP 10; Põllumajandustootjate üld- ja finantsandmed

Top Income Shares in Greece: 1957-2010

Directory of Open Access Journals (Sweden)

Kostas Chrissis

2013-11-01

Full Text Available This paper analyses the evolution of top income shares in Greece for the period 1957 to 2010 following Piketty (2001 methodology. We present the 10%, 5%, 2.5%, 2%, 1.5%, 1%, 0.5% and 0.1% income shares estimates which are based on tax statistics. The empirical results indicate that the behavior of the alternative estimated top income shares is quite similar. A ‘flat’ Ushaped pattern for most cases seems to exist. This common pattern is more apparent for the 2.5-0.1% top income shares. The top 10% and 5% income shares seem to be more volatile, accompanied with an increasing trend by the end of the period. This paper is an attempt to extend the existing research in southern Europe by presenting the relevant Greek experience. For the whole period, country comparisons show that the 1% top income share in Greece is in lower levels than that of USA and the other European countries (Italy, Portugal, Spain, France, Germany.

Systems Analysis of NASA Aviation Safety Program: Final Report

Science.gov (United States)

Jones, Sharon M.; Reveley, Mary S.; Withrow, Colleen A.; Evans, Joni K.; Barr, Lawrence; Leone, Karen

2013-01-01

A three-month study (February to April 2010) of the NASA Aviation Safety (AvSafe) program was conducted. This study comprised three components: (1) a statistical analysis of currently available civilian subsonic aircraft data from the National Transportation Safety Board (NTSB), the Federal Aviation Administration (FAA), and the Aviation Safety Information Analysis and Sharing (ASIAS) system to identify any significant or overlooked aviation safety issues; (2) a high-level qualitative identification of future safety risks, with an assessment of the potential impact of the NASA AvSafe research on the National Airspace System (NAS) based on these risks; and (3) a detailed, top-down analysis of the NASA AvSafe program using an established and peer-reviewed systems analysis methodology. The statistical analysis identified the top aviation "tall poles" based on NTSB accident and FAA incident data from 1997 to 2006. A separate examination of medical helicopter accidents in the United States was also conducted. Multiple external sources were used to develop a compilation of ten "tall poles" in future safety issues/risks. The top-down analysis of the AvSafe was conducted by using a modification of the Gibson methodology. Of the 17 challenging safety issues that were identified, 11 were directly addressed by the AvSafe program research portfolio.

Patients' experiences of safety during haemodialysis treatment--a qualitative study

NARCIS (Netherlands)

Lovink, Marleen H; Kars, Marijke C; de Man-van Ginkel, Janneke M; Schoonhoven, Lisette

2015-01-01

AIM: To explore the experiences of safety of adult patients during their haemodialysis treatment. BACKGROUND: Haemodialysis is a complex treatment with a risk for harm that causes anxiety among many patients. To date, no in-depth study of haemodialysis patients' emotional responses to conditions of

Patients' experiences of safety during haemodialysis treatment - a qualitative study

NARCIS (Netherlands)

Lovink, M.H.; Kars, M.C.; Man-van Ginkel, J.M. de; Schoonhoven, L.

2015-01-01

AIM: To explore the experiences of safety of adult patients during their haemodialysis treatment. BACKGROUND: Haemodialysis is a complex treatment with a risk for harm that causes anxiety among many patients. To date, no in-depth study of haemodialysis patients' emotional responses to conditions of

Top-philic scalar Dark Matter with a vector-like fermionic top partner

Science.gov (United States)

Baek, Seungwon; Ko, Pyungwon; Wu, Peiwen

2016-10-01

We consider a simple extension of the Standard Model with a scalar top-philic Dark Matter (DM) S coupling, apart from the Higgs portal, exclusively to the right-handed top quark t R and a colored vector-like top partner T with a Yukawa coupling y ST which we call the topVL portal. When the Higgs portal is closed and y ST is perturbative (≲1), T S → ( W + b, gt), SSto toverline{t} and Toverline{T}to (qoverline{q}, gg) provide the dominant (co) annihilation contributions to obtain ΩDM h 2 ≃ 0 .12 in light, medium and heavy DM mass range, respectively. However, large {y}_{ST}˜ O(10) can make SS → gg dominate via the loop-induced coupling C SSgg in the m S < m t region. In this model it is the C SSgg coupling that generates DM-nucleon scattering in the direct detection, which can be large and simply determined by ΩDM h 2 ≃ 0 .12 when SS → gg dominates the DM annihilation. The current LUX results can exclude the SS → gg dominating scenario and XENON-1T experiment may further test y ST ≳ 1, and 0 .5 ≲ y ST ≲ 1 may be covered in the future LUX-ZP experiment. The current indirect detection results from Fermi gamma-ray observations can also exclude the SS → gg dominating scenario and are sensitive to the heavy DM mass region, of which the improved sensitivity by one order will push DM mass to be above 400, 600, 1000 GeV for y ST = 0 .3 , 0 .5 , 1 .0, respectively. Toverline{T} pair produced at the hadron collider will decay 100% into [InlineMediaObject not available: see fulltext.] signal when kinematically open. The latest ATLAS 13 TeV 13.2 fb-1 data can excluded m T between 300 (650) and 1150 (1100) GeV for m S =40 (400) GeV and the exclusion region can reach up to m S ˜ 500 GeV.

Measurement of the charge asymmetry in highly boosted top-quark pair production in s=8 TeV pp collision data collected by the ATLAS experiment

Directory of Open Access Journals (Sweden)

G. Aad

2016-05-01

Full Text Available In the pp→tt¯ process the angular distributions of top and anti-top quarks are expected to present a subtle difference, which could be enhanced by processes not included in the Standard Model. This Letter presents a measurement of the charge asymmetry in events where the top-quark pair is produced with a large invariant mass. The analysis is performed on 20.3 fb−1 of pp collision data at s=8TeV collected by the ATLAS experiment at the LHC, using reconstruction techniques specifically designed for the decay topology of highly boosted top quarks. The charge asymmetry in a fiducial region with large invariant mass of the top-quark pair (mtt¯>0.75 TeV and an absolute rapidity difference of the top and anti-top quark candidates within −2<|yt|−|yt¯|<2 is measured to be 4.2±3.2%, in agreement with the Standard Model prediction at next-to-leading order. A differential measurement in three tt¯ mass bins is also presented.

Bunch rotation tests at SPS flat top for the AWAKE experiment

CERN Document Server

Argyropoulos, T; Bohl, T; Esteban Müller, J F; Petrenko, A; Shaposhnikova, E; Timko, H

2013-01-01

This note summarises the results of two MDs on bunch rotation at SPS flat top. The first MD was carried out on 11th July 2012 with the Q26 optics, while the second MD on the 30th October 2012 used the Q20 optics. To obtain a short bunch length, which is important for the plasma wake-field acceleration project AWAKE, the bunches have been rotated in longitudinal phase space on the SPS flat top. The aim of the MDs was to obtain first estimates of what bunch length, intensity, and transverse emittances - which are crucial for the project - can be achieved for high-intensity single bunches.

Invasion of top and intermediate consumers in a size structured fish community

OpenAIRE

Ask, Per

2010-01-01

In this thesis I have investigated the effects of invading top and intermediate consumers in a size-structured fish community, using a combination of field studies, a lake invasion experiment and smaller scale pond and aquaria experiments. The lake invasion experiment was based on introductions of an intermediate consumer, ninespine stickleback (Pungitius pungitius L.), in to allopatric populations of an omnivorous top predator, Arctic char (Salvelinus alpinus L.). The invasion experiment was...

JET-ISX-B beryllium limiter experiment safety analysis report and operational safety requirements

International Nuclear Information System (INIS)

Edmonds, P.H.

1985-09-01

An experiment to evaluate the suitability of beryllium as a limiter material has been completed on the ISX-B tokamak. The experiment consisted of two phases: (1) the initial operation and characterization in the ISX experiment, and a period of continued operation to the specified surface fluence (10 22 atoms/cm 2 ) of hydrogen ions; and (2) the disassembly, decontamination, or disposal of the ISX facility. During these two phases of the project, the possibility existed for beryllium and/or beryllium oxide powder to be produced inside the vacuum vessel. Beryllium dust is a highly toxic material, and extensive precautions are required to prevent the release of the beryllium into the experimental work area and to prevent the contamination of personnel working on the device. Details of the health hazards associated with beryllium and the appropriate precautions are presented. Also described in appendixes to this report are the various operational safety requirements for the project

TOP LINAC design

International Nuclear Information System (INIS)

Picardi, L.; Ronsivalle, C.; Vignati, A.

1997-11-01

The report describes a linear accelerator for protons named TOP LINAC designed for the TOP (Terapia Oncologica con Protoni, Oncological Protontherapy) project launched by the Italian National Institute of Health (Istituto Superiore di Sanita', ISS) to explore in collaboration with the biggest Oncological Hospital in Rome (Istituto Regina Elena, IRE) the potentialities of the therapy with accelerated protons and establish guide lines for the application of this new type of radiotherapy in comparison with the more traditional electron and x-rays radiotherapy. The concept of a compact accelerator for protontherapy applications bore within the Italian Hadrontherapy Collaboration (TERA Collaboration) with the aim to diffuse the protontherapy on the National territory. The ISS program plans to use the TOP linac proton beam also for production of PET (Positron Emission Tomography) radioisotopes and radiobiology studies. Official agreements are in course between ISS and ENEA which provides its experience in the industrial and medical accelerators for the design and the construction of the TOP linac. The accelerator that will be the first 3 GHz proton linac in the world, will be composed of a 428.3 MHz 7 Me V RFQ + DTL injector followed by a 7-65 Me V section of a 3 GHz SCDTL structure and a 65 - 200 Me V variable energy SCL 3 GHz structure. In particular the SCDTL section uses a highly innovative accelerating structure patented by ENEA. In this report the clinical and physical requests are discussed and a preliminary design of the whole machine is given

Revealing Ligand Binding Sites and Quantifying Subunit Variants of Noncovalent Protein Complexes in a Single Native Top-Down FTICR MS Experiment

Science.gov (United States)

Li, Huilin; Wongkongkathep, Piriya; Van Orden, Steve L.; Ogorzalek Loo, Rachel R.; Loo, Joseph A.

2014-12-01

"Native" mass spectrometry (MS) has been proven to be increasingly useful for structural biology studies of macromolecular assemblies. Using horse liver alcohol dehydrogenase (hADH) and yeast alcohol dehydrogenase (yADH) as examples, we demonstrate that rich information can be obtained in a single native top-down MS experiment using Fourier transform ion cyclotron mass spectrometry (FTICR MS). Beyond measuring the molecular weights of the protein complexes, isotopic mass resolution was achieved for yeast ADH tetramer (147 kDa) with an average resolving power of 412,700 at m/z 5466 in absorption mode, and the mass reflects that each subunit binds to two zinc atoms. The N-terminal 89 amino acid residues were sequenced in a top-down electron capture dissociation (ECD) experiment, along with the identifications of the zinc binding site at Cys46 and a point mutation (V58T). With the combination of various activation/dissociation techniques, including ECD, in-source dissociation (ISD), collisionally activated dissociation (CAD), and infrared multiphoton dissociation (IRMPD), 40% of the yADH sequence was derived directly from the native tetramer complex. For hADH, native top-down ECD-MS shows that both E and S subunits are present in the hADH sample, with a relative ratio of 4:1. Native top-down ISD of the hADH dimer shows that each subunit (E and S chains) binds not only to two zinc atoms, but also the NAD/NADH ligand, with a higher NAD/NADH binding preference for the S chain relative to the E chain. In total, 32% sequence coverage was achieved for both E and S chains.

Autotranspordifirmade TOP 100

Index Scriptorium Estoniae

2006-01-01

Ilmunud ka: Delovõje Vedomosti : Transport i Logistika 29. nov. lk. 10-11. Autofirmade TOP 100. Vt. samas: Käibe TOP 10; Käibe kasvu TOP 10; Majandustegevuse kasumi TOP 10; Kasumi kasvu TOP 10; Rentaabluse TOP 10; Omakapitali tootlikkuse TOP 10; Autotranspordifirmade üld- ja finantsandmed. Delovõje Vedomosti : Transport i Logistika sisaldab tabelit Autofirmade TOP 100

Part I. Fuel-motion diagnostics in support of fast-reactor safety experiments. Part II. Fission product detection system in support of fast reactor safety experiments

International Nuclear Information System (INIS)

Devolpi, A.; Doerner, R.C.; Fink, C.L.; Regis, J.P.; Rhodes, E.A.; Stanford, G.S.; Braid, T.H.; Boyar, R.E.

1986-05-01

In all destructive fast-reactor safety experiments at TREAT, fuel motion and cladding failure have been monitored by the fast-neutron/gamma-ray hodoscope, providing experimental results that are directly applicable to design, modeling, and validation in fast-reactor safety. Hodoscope contributions to the safety program can be considered to fall into several groupings: pre-failure fuel motion, cladding failure, post-failure fuel motion, steel blockages, pretest and posttest radiography, axial-power-profile variations, and power-coupling monitoring. High-quality results in fuel motion have been achieved, and motion sequences have been reconstructed in qualitative and quantitative visual forms. A collimated detection system has been used to observe fission products in the upper regions of a test loop in the TREAT reactor. Particular regions of the loop are targeted through any of five channels in a rotatable assembly in a horizontal hole through the biological shield. A well-type neutron detector, optimized for delayed neutrons, and two GeLi gamma ray spectrometers have been used in several experiments. Data are presented showing a time history of the transport of Dn emitters, of gamma spectra identifying volatile fission products deposited as aerosols, and of fission gas isotopes released from the coolant

Measurements and searches with top quarks

International Nuclear Information System (INIS)

Peters, Reinhild Yvonne

2008-01-01

In 1995 the last missing member of the known families of quarks, the top quark, was discovered by the CDF and D0 experiments at the Tevatron, a proton-antiproton collider at Fermilab near Chicago. Until today, the Tevatron is the only place where top quarks can be produced. The determination of top quark production and properties is crucial to understand the Standard Model of particle physics and beyond. The most striking property of the top quark is its mass--of the order of the mass of a gold atom and close to the electroweak scale--making the top quark not only interesting in itself but also as a window to new physics. Due to the high mass, much higher than of any other known fermion, it is expected that the top quark plays an important role in electroweak symmetry breaking, which is the most prominent candidate to explain the mass of particles. In the Standard Model, electroweak symmetry breaking is induced by one Higgs field, producing one additional physical particle, the Higgs boson. Although various searches have been performed, for example at the Large Electron Positron Collider (LEP), no evidence for the Higgs boson could yet be found in any experiment. At the Tevatron, multiple searches for the last missing particle of the Standard Model are ongoing with ever higher statistics and improved analysis techniques. The exclusion or verification of the Higgs boson can only be achieved by combining many techniques and many final states and production mechanisms. As part of this thesis, the search for Higgs bosons produced in association with a top quark pair (t(bar t)H) has been performed. This channel is especially interesting for the understanding of the coupling between Higgs and the top quark. Even though the Standard Model Higgs boson is an attractive candidate, there is no reason to believe that the electroweak symmetry breaking is induced by only one Higgs field. In many models more than one Higgs boson are expected to exist, opening even more channels

Statistical and systematic treatment issues in top quark mass combinations

CERN Document Server

Maier, Andreas Alexander; The ATLAS collaboration

2015-01-01

The past years have seen tremendous improvements in the precision of top quark mass measurements at hadron colliders. Since these measurements are mostly limited by systematic uncertainties, the achievable precision of a single measurement depends on developments in the experimental and theoretical understanding of top quark events. Complementing these efforts, a precision gain can also be obtained by a combination of measurements, exploiting their correlation. With ever increasing precision of single experiment top quark mass measurements, this approach becomes more and more promising, because the absolute precision gain of refined techniques in both theory and experiment tends to saturate. This requires a precise matching of uncertainty categories and a detailed evaluation of the correlations of observables. This article reviews the status and points out the challenges faced in the ATLAS and CMS LHC top quark mass combination effort.

Thermal design of top shield for PFBR

International Nuclear Information System (INIS)

Gajapathy, R.; Jalaludeen, S.; Selvaraj, A.; Bhoje, S.B.

1988-01-01

India's Liquid Metal Cooled Fast Breeder Reactor programme started with the construction of loop type 13MW(e) Fast Breeder Test Reactor (FBTR) which attained criticality in October 1985. With the experience of FBTR, the design work on pool type 500 MW(e) Prototype Fast Breeder Reactor (PFBR) which will be a forerunner for future commercial fast breeder reactors, has been started. The Top Shield forms the cover for the main vessel which contains the primary circuit. Argon cover gas separates the Top Shield from the free level of hot sodium pool (803K). The Top Shield which is of box type construction consists of control plug, two rotatable plugs and roof slab, assembled together, which provide biological shielding, thermal shielding and leak tight containment at the top of the main vessel. Heat is transferred from the sodium pool to the Top Shield through argon cover gas and through components supported by it and dipped in the sodium pool. The Top Shield should be maintained at the desired operating temperature by incorporating a cooling system inside it. Insulation may be provided below the bottom plate to reduce the heat load to the cooling system, if required. The thermal design of Top Shield consists of estimation of heat transfer to the Top Shield, selection of operating temperature, assessment of insulation requirement, design of cooling system and evaluation of transient temperature changes

Exposure to radiation from base stations of mobile communication systems on top of buildings

International Nuclear Information System (INIS)

Correia, L.M.

2001-01-01

This paper discusses the problems related with the safety of people exposed to radiation coming from base stations of mobile communication systems installed on the top of buildings in urban environments. After introducing the problem, the approach taken in the paper is presented: the issue is not to know if exposure to radiation is hazardous but to know what are the exposure limits that may constitute danger. Afterwards, the maximum values recommended by several international bodies are shown for the specific absorption range in the frequency range of mobile communications and, in particular, for GSM. Measurements done in a building in Lisbon, Portugal, with antennas on its top show that the signal is circa 50,000 times below the maximum values, hence perfectly within the safety margins. One can say that, in the large majority of cases, there is no danger for people working or living in buildings with base station antennas installed on their top (author)

Proceedings of the workshop on integral experiment covariance data for critical safety validation

Energy Technology Data Exchange (ETDEWEB)

Stuke, Maik (ed.)

2016-04-15

For some time, attempts to quantify the statistical dependencies of critical experiments and to account for them properly in validation procedures were discussed in the literature by various groups. Besides the development of suitable methods especially the quality and modeling issues of the freely available experimental data are in the focus of current discussions, carried out for example in the Expert Group on Uncertainty Analysis for Criticality Safety Assessment (UACSA) of the OECD-NEA Nuclear Science Committee. The same committee compiles and publishes also the freely available experimental data in the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Most of these experiments were performed as series and might share parts of experimental setups leading to correlated results. The quality of the determination of these correlations and the underlying covariance data depend strongly on the quality of the documentation of experiments.

Proceedings of the workshop on integral experiment covariance data for critical safety validation

International Nuclear Information System (INIS)

Stuke, Maik

2016-04-01

For some time, attempts to quantify the statistical dependencies of critical experiments and to account for them properly in validation procedures were discussed in the literature by various groups. Besides the development of suitable methods especially the quality and modeling issues of the freely available experimental data are in the focus of current discussions, carried out for example in the Expert Group on Uncertainty Analysis for Criticality Safety Assessment (UACSA) of the OECD-NEA Nuclear Science Committee. The same committee compiles and publishes also the freely available experimental data in the International Handbook of Evaluated Criticality Safety Benchmark Experiments. Most of these experiments were performed as series and might share parts of experimental setups leading to correlated results. The quality of the determination of these correlations and the underlying covariance data depend strongly on the quality of the documentation of experiments.

Toward the Extreme Ultra Violet Four Wave Mixing Experiments: From Table Top Lasers to Fourth Generation Light Sources

OpenAIRE

Riccardo Cucini; Andrea Battistoni; Filippo Bencivenga; Alessandro Gessini; Riccardo Mincigrucci; Erika Giangrisostomi; Emiliano Principi; Flavio Capotondi; Emanuele Pedersoli; Michele Manfredda; Maya Kiskinova; Claudio Masciovecchio

2015-01-01

Three different Transient Grating setups are presented, with pulsed and continuous wave probe at different wavelengths, ranging from infrared to the extreme ultra violet region. Both heterodyne and homodyne detections are considered. Each scheme introduces variations with respect to the previous one, allowing moving from classical table top laser experiments towards a new four wave mixing scheme based on free electron laser radiation. A comparison between the various setups and the first resu...

Measurement of the t-channel single-top-quark-production cross section and the CKM-matrix element Vtb with the CMS experiment

International Nuclear Information System (INIS)

Klingebiel, Dennis

2014-01-01

The electroweak production of single top quarks offers a unique access to the Cabibbo-Kobayashi-Maskawa (CKM) matrix element V tb , which is a fundamental parameter of the Standard Model of particle physics (SM). In this thesis, measurements of the inclusive t-channel single-top-quark-production cross section, the CKM-matrix element V tb , and the ratio of t-channel top-quark-production and top-antiquark-production cross sections are presented. Proton-proton collisions with a center-of-mass energy of 7 TeV are analyzed. These collisions were recorded with the Compact Muon Solenoid (CMS) experiment at the particle-accelerator complex Large Hadron Collider (LHC), which is operated by the European Organization for Nuclear Research (CERN) near Geneva, Switzerland. The analyzed data correspond to an integrated luminosity of 1.6/fb. This analysis uses events with at least two jets and either an electron or muon. Each event is classified according to the flavor and charge of the electron or muon, the number of jets, and the number of b-tagged jets. Signal and background processes are discriminated using Boosted Decision Trees (BDTs). The signal cross section is simultaneously measured in twelve orthogonal categories. A Bayesian approach is used to infer the signal cross section from data. Particular emphasis is placed on the modeling of systematic uncertainties and the evaluation of their impact on the measurement. Systematic uncertainties are incorporated as additional nuisance parameters into the likelihood function. Marginalization is used to eliminate the nuisance parameters. The single-top-quark t-channel production cross section is measured to be (66.6 +6.7 -6.2 ) pb. The measured value is in agreement with the next-to-next-to-leading order SM prediction. With a relative uncertainty of -9.3% +10.1%, this measurement is significantly more precise than previous measurements in proton-proton und proton-antiproton collisions. The absolute value of the CKM-matrix element

Experiment to evaluate software safety

International Nuclear Information System (INIS)

Soubies, B.; Henry, J.Y.

1994-01-01

The process of licensing nuclear power plants for operation consists of mandatory steps featuring detailed examination of the instrumentation and control system by the safety authorities, including softwares. The criticality of these softwares obliges the manufacturer to develop in accordance with the IEC 880 standard 'Computer software in nuclear power plant safety systems' issued by the International Electronic Commission. The evaluation approach, a two-stage assessment is described in detail. In this context, the IPSN (Institute of Protection and Nuclear Safety), the technical support body of the safety authority uses the MALPAS tool to analyse the quality of the programs. (R.P.). 4 refs

Experiences in assessing safety culture

International Nuclear Information System (INIS)

Spitalnik, J.

2002-01-01

Based on several Safety Culture self-assessment applications in nuclear organisations, the paper stresses relevant aspects to be considered when programming an assessment of this type. Reasons for assessing Safety Culture, basic principles to take into account, necessary resources, the importance of proper statistical analyses, the feed-back of results, and the setting up of action plans to enhance Safety Culture are discussed. (author)

Probing the Top-Yukawa Coupling by Searching for Associated Higgs Boson Production with a Single Top Quark at the CMS Experiment

CERN Document Server

Fink, Simon; Quast, Günter

In this thesis the associated production of a single top quark with a Higgs boson is studied. This process is especially well suited for probing of the Top-Yukawa coupling, as the cross section of the tH process increases for couplings deviating from the Standard Model prediction. Upper exclusion limits are set on the tH production by analyzing the data recorded during Run-I and recorded in 2015 during Run-II of the LHC with the CMS detector.

Safety climate and safety behaviors in the construction industry: The importance of co-workers commitment to safety.

Science.gov (United States)

Schwatka, Natalie V; Rosecrance, John C

2016-06-16

There is growing empirical evidence that as safety climate improves work site safety practice improve. Safety climate is often measured by asking workers about their perceptions of management commitment to safety. However, it is less common to include perceptions of their co-workers commitment to safety. While the involvement of management in safety is essential, working with co-workers who value and prioritize safety may be just as important. To evaluate a concept of safety climate that focuses on top management, supervisors and co-workers commitment to safety, which is relatively new and untested in the United States construction industry. Survey data was collected from a cohort of 300 unionized construction workers in the United States. The significance of direct and indirect (mediation) effects among safety climate and safety behavior factors were evaluated via structural equation modeling. Results indicated that safety climate was associated with safety behaviors on the job. More specifically, perceptions of co-workers commitment to safety was a mediator between both management commitment to safety climate factors and safety behaviors. These results support workplace health and safety interventions that build and sustain safety climate and a commitment to safety amongst work teams.

Searches for heavy resonances in all-jet final states with top quarks using jet substructure techniques with the CMS Experiment

CERN Document Server

Usai, Emanuele; Haller, Johannes

2017-01-01

While the Standard Model is very successful in describing subnuclear phenomena, it is not acomplete theory of particle physics. Several new theories have been developed to address itsissues. Many extensions of the Standard Model predict the existence of high-mass resonances.In some cases these resonances have an enhanced coupling to third generation quarks or toa hypothetical new generation of heavy non-chiral quarks. This thesis describes two searchesfor new phenomena compatible with these theories, in particular a search is presented forresonant top-antitop production, and the first search for heavy resonances decaying to a topquark and a heavy top quark partner T is shown.The searches target the all-jets decay channels and use data collected by the CMS Experiment at the CERN LHC between 2012 and 2015 at a center-of-mass energy of 8 TeV and13 TeV. Due to the high mass of the resonances considered, the final state particles have ahigh Lorentz-boost. To reconstruct the hadronic decay of the top quarks and W...

Current MitraClip experience, safety and feasibility in the Netherlands

NARCIS (Netherlands)

Rahhab, Z.; Kortlandt, F. A.; Velu, J. F.; Schurer, R. A. J.; Delgado, V.; Tonino, P.; Boven, A. J.; van den Branden, B. J. L.; Kraaijeveld, A. O.; Voskuil, M.; Hoorntje, J.; van Wely, M. [=Marleen; van Houwelingen, K.; Bleeker, G. B.; Rensing, B.; Kardys, I.; Baan, J.; van der Heyden, J. A. S.; van Mieghem, N. M.

2017-01-01

Purpose Data on MitraClip procedural safety and efficacy in the Netherlands are scarce. We aim to provide an overview of the Dutch MitraClip experience. Methods We pooled anonymised demographic and procedural data of 1151 consecutive MitraClip patients, from 13 Dutch hospitals. Data was collected by

The development of safety cases for healthcare services: Practical experiences, opportunities and challenges

International Nuclear Information System (INIS)

Sujan, Mark; Spurgeon, Peter; Cooke, Matthew; Weale, Andy; Debenham, Philip; Cross, Steve

2015-01-01

There has been growing interest in the concept of safety cases for medical devices and health information technology, but questions remain about how safety cases can be developed and used meaningfully in the safety management of healthcare services and processes. The paper presents two examples of the development and use of safety cases at a service level in healthcare. These first practical experiences at the service level suggest that safety cases might be a useful tool to support service improvement and communication of safety in healthcare. The paper argues that safety cases might be helpful in supporting healthcare organisations with the adoption of proactive and rigorous safety management practices. However, it is also important to consider the different level of maturity of safety management and regulatory oversight in healthcare. Adaptations to the purpose and use of safety cases might be required, complemented by the provision of education to both practitioners and regulators. - Highlights: • Empirical description of safety case development at service level in healthcare. • Safety cases can support adoption of proactive and rigorous safety management. • Adaptation to purpose and use of safety cases might be required in healthcare. • Education should be provided to practitioners and regulators

Simulation of Top Quark Production for the ATLAS Experiment

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00352736; The ATLAS collaboration

2016-01-01

The Monte Carlo setups used by ATLAS to model the $t\\bar{t}$ and single-top production in 13 TeV pp collisions are described. The performance of different event generators is assessed by comparing measurements at 7 TeV, 8 TeV and 13 TeV to predictions from simulated data. The evaluation of systematic uncertainties and the dependence of generator predictions on the tuning parameters are also discussed.

Impact loads on the pressure vessel top

International Nuclear Information System (INIS)

Krieg, R.; Malmberg, T.; Messemer, G.

1995-01-01

A steam explosion can cause core melt to be bounced against the internal side of the RPV top. The bouncing velocity up to which the top can withstand the impact is to be determined. Plausible assumptions about a core melt mass of 80000 kg result in a tolerable maximum bouncing velocity of about 200 m/s. Reliable estimates are expected from the BERDA experiments simulating a pessimistic course of events on a 1:10 scale. (orig.)

Measuring top-quark polarization in top-pair + missing-energy events.

Science.gov (United States)

Berger, Edmond L; Cao, Qing-Hong; Yu, Jiang-Hao; Zhang, Hao

2012-10-12

The polarization of a top quark can be sensitive to new physics beyond the standard model. Since the charged lepton from top-quark decay is maximally correlated with the top-quark spin, it is common to measure the polarization from the distribution in the angle between the charged lepton and the top-quark directions. We propose a novel method based on the charged lepton energy fraction and illustrate the method with a detailed simulation of top-quark pairs produced in supersymmetric top squark pair production. We show that the lepton energy ratio distribution that we define is very sensitive to the top-quark polarization but insensitive to the precise measurement of the top-quark energy.

Anomalous creation and decay of top quarks

CERN Document Server

Hasegawa, S; The ATLAS collaboration

2012-01-01

Due to the top quark’s mass of 173.5 GeV/c2 which is around the energy scale of the spon- taneous symmetry breaking, appearance of new physics can be expected in its production and decay as an anomaly from the standard model expectation. The ATLAS and the CMS experiments have accumulated about 5 fb−1 of data of proton-proton collisions with 7 TeV center of mass energy in 2011, in which 800,000 top quarks pairs are expected. With this high statistics, the ATLAS and the CMS collaborations have investigated the top quark’s production and decay precisely and have reported the results consistent with the standard model.

AST-500 safety analysis experience

Energy Technology Data Exchange (ETDEWEB)

Falikov, A A; Bakhmetiev, A M; Kuul, V S; Samoilov, O B [OKBM, Nizhny Novgorod (Russian Federation)

1997-09-01

Characteristic AST-type NHR safety features and requirements are described briefly. The main approaches and results of design and beyond-design accidents analyses for the AST-500 NHR, and the results of probabilistic safety assessments are considered. It is concluded that the AST-500 possesses a high safety level in virtue of the development and realization in the design of self-protection, passivity and defence-in-depth principles. (author). 9 refs, 2 figs.

Safety and operating experience at EBR-II: lessons for the future

International Nuclear Information System (INIS)

Sackett, J.I.; Golden, G.H.

1981-01-01

EBR-II is a small LMFBR power plant that has performed safely and reliably for 16 years. Much has been learned from operating it to facilitate the design, licensing, and operation of large commercial LMFBR power plants in the US. EBR-II has been found relatively easy to keep in conformity with evolving safety requirements, largely because of inherent safety features of the plant. Such features reduce dependence on active safety systems to protect against accidents. EBR-II has experienced a number of plant-transient incidents, some planned, others inadvertent; none has resulted in any significant plant damage. The operating experience with EBR-II has led to the formulation of an Operational Reliability Test Program (ORTP), aimed at showing inherently safe performance of fuel and plant systems

Preparation of the Atlas experiment: electronic calibration of the electromagnetic calorimeter, measurement of the W boson polarization in top quark decay

International Nuclear Information System (INIS)

Labbe, J.

2009-07-01

The CERN Large Hadron Collider (LHC) will probe the fundamental constituents of matter at an unprecedented microscopic scale. This instrument will lead to further tests and constraints of the Standard Model and its potential extensions at the energies of few TeV. The ATLAS experiment is therefore installed at one of the four interaction points of the LHC. The top quark will be abundantly produced at LHC. Competitive results on its production and decay mechanisms should be quickly obtained. Unlike the other quarks, the top quark does not have time to hadronize before it decays, then allowing spin effects to be measured. It decays into a W boson and a bottom quark, which are polarized by the parity symmetry violation of the weak interaction. In this thesis, the polarization of the W bosons produced in the decay of top quark pairs into a charged lepton and many jets is studied. This measurement is performed by predicting the experimental angular distribution of the charged lepton for each helicity state of the W boson. It allows to constraint the interaction vertex between the top quark, the W boson and bottom quark. The sensitivity of the ATLAS experiment on anomalous couplings of this vertex is estimated in a generic, model-independent, approach. The validation of ATLAS's results will require a good knowledge of all its instruments. Its electromagnetic calorimeter is in particular characterized with an electronic calibration. This thesis presents the jitter and crosstalk studies realized on the ATLAS electromagnetic calorimeter during its final installation. Moreover, the interest of crosstalk analyzes for problematic channels identification is shown. The slides made for the defence of the thesis have been added at the end of the document. (author)

Applying the results of probablistic safety analysis of nuclear power plants: a survey of experience

International Nuclear Information System (INIS)

Andrews, W.B.; Herttrich, M.; Koeberlein, K.; Schwager.

1985-01-01

To date, discussions of the many different types of potential applications of PRA/PSA results and insights to safety-decision-making have been mainly theoretical. Various safety goals have been proposed as decision criteria. However, the discussion on the role of PRA/PSA and Safety Goals in safety-decision-making, especially in licensing, is controversial. A Working Group of the OECD Nuclear Energy Agency is completing a compilation and evaluation of real examples of past and present practical experience with the application of probabilistic methods in reactor safety decision-making, with the idea of developing a common understanding in this area. More than fifty different cases where PRA has influenced decision-making have been surveyed. These include, for example, regulatory changes, fixing of licensing requirements, plant specific modifications of design of operation, prioritization of safety issues and emergency planning. This feedback of experience - both positive and negative - with PRA/PSA applications is considered to provide guidance on how probabilistic approaches can be introduced into current safety practices, and on desirable future developments in probabilistic methods and specific PSA/PRA studies. Generic insights from the survey are given

ORALLOY (93.2 235U) METAL CYLINDER WITH BERYLLIUM TOP REFLECTOR

International Nuclear Information System (INIS)

Bess, John D.; Montierth, Leland M.; Reed, Raymond L.; Mihalczo, John T.

2010-01-01

A variety of critical experiments were constructed of enriched uranium metal during the 1960s and 1970s at the Oak Ridge Critical Experiments Facility (ORCEF) in support of criticality safety operations at the Y-12 Plant. The purposes of these experiments included the evaluation of storage, casting, and handling limits for the Y-12 Plant and providing data for verification of calculation methods and cross-sections for nuclear criticality safety applications. These included solid cylinders of various diameters, annuli of various inner and outer diameters, two and three interacting cylinders of various diameters, and graphite and polyethylene reflected cylinders and annuli. Of the hundreds of delayed critical experiments, one experiment was comprised of a stack of approximately 7-inch-diameter metal discs. The bottom of the stack consisted of uranium with an approximate height of 4-1/8 inches. The top of the stack consisted of beryllium with an approximate height of 5-9/16 inches. This experiment was performed on August 20, 1963 by J. T. Mihalczo and R. G. Taylor (Ref. 1) with accompanying logbook. Both detailed and simplified model specifications are provided in this evaluation. This fast-spectra experiment was determined to represent an acceptable benchmark. The calculated eigenvalues for both the detailed and simple models are within approximately 0.5% of the benchmark values, but significantly greater than 3s from the benchmark value because the uncertainty in the benchmark is very small: ±0.0002 (1s). There is significant variability between results using different neutron cross section libraries, the greatest being a k eff of ∼0.65% . Unreflected and unmoderated experiments with the same highly enriched uranium metal parts were performed at the Oak Ridge Critical Experiments Facility in the 1960s and are evaluated in HEU MET FAST 051. Thin graphite reflected (2 inches or less) experiments also using the same highly enriched uranium metal parts are evaluated

Top Yukawa deviation in extra dimension

International Nuclear Information System (INIS)

Haba, Naoyuki; Oda, Kin-ya; Takahashi, Ryo

2009-01-01

We suggest a simple one-Higgs-doublet model living in the bulk of five-dimensional spacetime compactified on S 1 /Z 2 , in which the top Yukawa coupling can be smaller than the naive standard-model expectation, i.e. the top quark mass divided by the Higgs vacuum expectation value. If we find only single Higgs particle at the LHC and also observe the top Yukawa deviation, our scenario becomes a realistic candidate beyond the standard model. The Yukawa deviation comes from the fact that the wave function profile of the free physical Higgs field can become different from that of the vacuum expectation value, due to the presence of the brane-localized Higgs potentials. In the Brane-Localized Fermion scenario, we find sizable top Yukawa deviation, which could be checked at the LHC experiment, with a dominant Higgs production channel being the WW fusion. We also study the Bulk Fermion scenario with brane-localized Higgs potential, which resembles the Universal Extra Dimension model with a stable dark matter candidate. We show that both scenarios are consistent with the current electroweak precision measurements.

Biodiversity mediates top-down control in eelgrass ecosystems: a global comparative-experimental approach.

Science.gov (United States)

Duffy, J Emmett; Reynolds, Pamela L; Boström, Christoffer; Coyer, James A; Cusson, Mathieu; Donadi, Serena; Douglass, James G; Eklöf, Johan S; Engelen, Aschwin H; Eriksson, Britas Klemens; Fredriksen, Stein; Gamfeldt, Lars; Gustafsson, Camilla; Hoarau, Galice; Hori, Masakazu; Hovel, Kevin; Iken, Katrin; Lefcheck, Jonathan S; Moksnes, Per-Olav; Nakaoka, Masahiro; O'Connor, Mary I; Olsen, Jeanine L; Richardson, J Paul; Ruesink, Jennifer L; Sotka, Erik E; Thormar, Jonas; Whalen, Matthew A; Stachowicz, John J

2015-07-01

Nutrient pollution and reduced grazing each can stimulate algal blooms as shown by numerous experiments. But because experiments rarely incorporate natural variation in environmental factors and biodiversity, conditions determining the relative strength of bottom-up and top-down forcing remain unresolved. We factorially added nutrients and reduced grazing at 15 sites across the range of the marine foundation species eelgrass (Zostera marina) to quantify how top-down and bottom-up control interact with natural gradients in biodiversity and environmental forcing. Experiments confirmed modest top-down control of algae, whereas fertilisation had no general effect. Unexpectedly, grazer and algal biomass were better predicted by cross-site variation in grazer and eelgrass diversity than by global environmental gradients. Moreover, these large-scale patterns corresponded strikingly with prior small-scale experiments. Our results link global and local evidence that biodiversity and top-down control strongly influence functioning of threatened seagrass ecosystems, and suggest that biodiversity is comparably important to global change stressors. © 2015 John Wiley & Sons Ltd/CNRS.

DASHBOARDS AND CONTROL CHARTS. EXPERIENCES IN IMPROVING SAFETY AT HANFORD WASHINGTON

International Nuclear Information System (INIS)

PREVETTE, S.S.

2006-01-01

The aim of this paper is to demonstrate the integration of safety methodology, quality tools, leadership, and teamwork at Hanford and their significant positive impact on safe performance of work. Dashboards, Leading Indicators, Control charts, Pareto Charts, Dr. W. Edward Deming's Red Bead Experiment, and Dr. Deming's System of Profound Knowledge have been the principal tools and theory of an integrated management system. Coupled with involved leadership and teamwork, they have led to significant improvements in worker safety and protection, and environmental restoration at one of the nation's largest nuclear cleanup sites

The role of quality management in safety case development - Nagra's experience

International Nuclear Information System (INIS)

Schneider, Juerg W.; Zuidema, Piet

2014-01-01

This paper discusses the role of quality management (QM) in safety case development based on Nagra's experience from a broad range of projects. These include Project Gewahr (L/ILW and HLW, Nagra, 1985), the Wellenberg Project (L/ILW, Nagra, 1994), Project Opalinus Clay (HLW, Nagra, 2002a, 2002b), and recent project work needed in the context of the Swiss site selection process (L/ILW and HLW, Nagra, 2008a, 2008b, 2008c, 2010). Broadly speaking, Nagra's Quality Management policy is focused on ensuring: i) the quality of the disposal system (siting, design and implementation); ii) the quality of the underlying scientific understanding, which are seen as key elements of a credible safety case, along with the quality of the safety calculations themselves and of compiling the safety case, including the drawing of conclusions (Nagra, 2002a). All aspects of QM discussed in this paper should be seen in this context. (authors)

Guide for understanding and evaluation of safety culture

International Nuclear Information System (INIS)

2008-01-01

This report was the guide of understanding and evaluation of safety culture. Operator's activities for enhancement of safety culture in nuclear installations became an object of safety regulation in the management system. Evaluation of operator's activities (including top management's involvement) to prevent degradation of safety culture and organization climate in daily works needed understanding of safety culture and diversity of operator's activities. This guide was prepared to check indications of degradation of safety culture and organization climate in operator's activities in daily works and encourage operator's activities to enhance safety culture improvement and good practice. Comprehensive evaluation of operator's activities to prevent degradation of safety culture and organization climate would be performed from the standpoints of 14 safety culture elements such as top management commitment, clear plan and implementation of upper manager, measures to avoid wrong decision making, questioning attitude, reporting culture, good communications, accountability and openness, compliance, learning system, activities to prevent accidents or incidents beforehand, self-assessment or third party evaluation, work management, change management and attitudes/motivation. Element-wise examples and targets for evaluation were attached with evaluation check tables. (T. Tanaka)

Recent results on top quark physics with the CMS detector

CERN Multimedia

CERN. Geneva

2015-01-01

Top quarks are produced abundantly at the LHC due to the large cross section, high luminosity and outstanding performance of the accelerator chain. These unique conditions have opened the door to precise measurements of the top quark cross section, the top quark's peculiar properties and to searches for new physics in the top quark sector. In this seminar, recent top quark measurements performed by the CMS experiment will be reviewed. The measurements are based on the data collected at center-of-mass energies of 7, 8 and 13 TeV. Special emphasis will be given to the latest inclusive cross section measurements including those that analyse the data taken after the restart of the LHC.

W, Z and top production measurements at LHCb

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00258880

2018-01-01

Due to its unique pseudorapidity coverage between 2 and 5 and excellent performance, the LHCb detector allows for complementary probe of electroweak and QCD processes to those at ATLAS and CMS experiments. Studies of electroweak boson and top production provide important probes of the Standard Model at LHC energies and constrain parton distribution functions. The recent results on theW, Z and top production are briefly summarized in the present proceedings.

Top quark pair production and top quark properties at CDF

Energy Technology Data Exchange (ETDEWEB)

Moon, Chang-Seong [INFN, Pisa

2016-06-02

We present the most recent measurements of top quark pairs production and top quark properties in proton-antiproton collisions with center-of-mass energy of 1.96 TeV using CDF II detector at the Tevatron. The combination of top pair production cross section measurements and the direct measurement of top quark width are reported. The test of Standard Model predictions for top quark decaying into $b$-quarks, performed by measuring the ratio $R$ between the top quark branching fraction to $b$-quark and the branching fraction to any type of down quark is shown. The extraction of the CKM matrix element $|V_{tb}|$ from the ratio $R$ is discussed. We also present the latest measurements on the forward-backward asymmetry ($A_{FB}$) in top anti-top quark production. With the full CDF Run II data set, the measurements are performed in top anti-top decaying to final states that contain one or two charged leptons (electrons or muons). In addition, we combine the results of the leptonic forward-backward asymmetry in $t\\bar t$ system between the two final states. All the results show deviations from the next-to-leading order (NLO) standard model (SM) calculation.

Access Safety Systems – New Concepts from the LHC Experience

CERN Document Server

Ladzinski, T; di Luca, S; Hakulinen, T; Hammouti, L; Riesco, T; Nunes, R; Ninin, P; Juget, J-F; Havart, F; Valentini, F; Sanchez-Corral Mena, E

2011-01-01

The LHC Access Safety System has introduced a number of new concepts into the domain of personnel protection at CERN. These can be grouped into several categories: organisational, architectural and concerning the end-user experience. By anchoring the project on the solid foundations of the IEC 61508/61511 methodology, the CERN team and its contractors managed to design, develop, test and commission on time a SIL3 safety system. The system uses a successful combination of the latest Siemens redundant safety programmable logic controllers with a traditional relay logic hardwired loop. The external envelope barriers used in the LHC include personnel and material access devices, which are interlocked door-booths introducing increased automation of individual access control, thus removing the strain from the operators. These devices ensure the inviolability of the controlled zones by users not holding the required credentials. To this end they are equipped with personnel presence detectors and th...

An interagency space nuclear propulsion safety policy for SEI - Issues and discussion

Science.gov (United States)

Marshall, A. C.; Sawyer, J. C., Jr.

1991-01-01

An interagency Nuclear Safety Policy Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative nuclear propulsion program to facilitate the implementation of mission planning and conceptual design studies. The NSPWG developed a top level policy to provide the guiding principles for the development and implementation of the nuclear propulsion safety program and the development of Safety Functional Requirements. In addition, the NSPWG reviewed safety issues for nuclear propulsion and recommended top level safety requirements and guidelines to address these issues. Safety topics include reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, safeguards, risk/reliability, operational safety, ground testing, and other considerations. In this paper the emphasis is placed on the safety policy and the issues and considerations that are addressed by the NSPWG recommendations.

The latest results on top quark pair cross-section measurement at the LHC-ATLAS experiment

CERN Document Server

Yamauchi, Katsuya; The ATLAS collaboration

2015-01-01

The latest results on top quark pair production cross-section measurement in proton-proton collisions at $\\sqrt{s}$ = 7\\,TeV and $\\sqrt{s}$ = 8\\,TeV with the ATLAS detector are reported. The inclusive cross-section was measured with relative uncertainty of 4\\% using the final state of the top quark pair including an electron and a muon. The measurement of the differential cross-section as functions of various observables such as the transverse momentum and the rapidity of the top quark and the invariant mass of the top quark pair system are also reported. These results are compared with various generators such as {\\sc Powheg}, {\\sc Alpgen} and {\\sc MC@NLO} and various sets of parton distribution functions.

Experience with nuclear safety standards development in non-governmental international organizations

International Nuclear Information System (INIS)

Becker, K.

1985-01-01

Besides the IAEA as a 'governmental' organization dealing with basic safety recommendations addressed primarily to the national regulatory bodies in developing countries, two closely related non-governmental international standards organizations have gained extensive experience in the field of nuclear standardization. Over more than 25 years since their formation, both (a) the International Organization for Standardization's (ISO) Technical Committee 85 'Nuclear Energy', in particular in its Sub-Committee 3 'Reactor Technology and Safety' and (b) the International Electrotechnical Commission's (IEC) Technical Committee 45 'Nuclear Instrumentation' have published numerous standards. A brief review is given of these, draft standards, and other documents planned to become international standards. Many of them deal with rather specialized topics typical for 'industrial' standards such as standardized procedures, instruments, methods, materials, test methods, terminology, and signs and symbols, but others are directly related to more basic safety issues. In some areas such as quality assurance, seismic aspects of siting and terminology, there has been in the past occasional overlap in the activities of the NUSS programme, IEC and ISO. Letters of Understanding have since 1981 contributed to clarifying the borderlines and to avoiding redundant efforts. Also, some experiences and problems are described arising, for example, from the harmonization of different national safety philosophies and traditions into universally accepted international standards, and the transfer of international standards into national standards systems. Finally, based on a recent comprehensive compilation of some 3300 nuclear standards and standards projects, an attempt is made to present a cost/benefit analysis and an outlook on future developments. (author)

Jet calibration and top quark mass measurement in the semi-leptonic channel in the ATLAS experiment

International Nuclear Information System (INIS)

Balli, Fabrice

2014-01-01

The main goal of this thesis is to provide a measurement as accurate as possible of the top quark mass in the semi-leptonic decay channel. This experimental measurement is made thanks to the ATLAS detector near LHC, a proton-proton collider. The main interests for this precision measurement are the physics constraints to the theoretical models of fundamental constituents. Besides, the top quark mass is a parameter allowing to have more information on the vacuum stability at the Planck scale within the Standard Model. Jet energy calibration is crucial to this measurement. The impact of real data taking conditions on this calibration and on jet performance is detailed. The top quark mass measurement using 2011 data collected at an energy in the center-of-mass of 7 TeV is presented. It is using a tri dimensional template analysis method. The measured top quark mass is: m(top) = 172.01 ± 0.92 (stat) ± 1.17 (syst) GeV. The 2012 data collected at an energy in the center-of-mass of 8 TeV are also analysed, and a preliminary result for the top quark mass is provided: m(top) = 172.82 ± 0.39 (stat) ± 1.12 (syst) GeV, the combination of both measurements being the most accurate result of this thesis: m(top) = 172.64 ± 0.37 (stat) ± 1.10 (syst) GeV. (author) [fr

Search for heavy resonances decaying to top quarks

CERN Document Server

Anders, Christoph Falk; The ATLAS collaboration

2018-01-01

Searches for new resonances that decay either to pairs of top quarks or a top and a b-quark will be presented. The searches are performed with the ATLAS experiment at the LHC using proton-proton collision data collected in 2015 and 2016 with a centre-of-mass energy of 13 TeV. The invariant mass spectrum of hypothetical resonances are examined for local excesses or deficits that are inconsistent with the Standard Model prediction.

Search for heavy resonances decaying to top quarks

CERN Document Server

D'Auria, Saverio; The ATLAS collaboration

2017-01-01

Searches for new resonances that decay either to pairs of top quarks or a top and a b-quark will be presented. The searches are performed with the ATLAS experiment at the LHC using proton-proton collision data collected in 2015 and 2016 with a centre-of-mass energy of 13 TeV. The invariant mass spectrum of hypothetical resonances are examined for local excesses or deficits that are inconsistent with the Standard Model prediction.

GROWTH OF THE INTERNATIONAL CRITICALITY SAFETY AND REACTOR PHYSICS EXPERIMENT EVALUATION PROJECTS

Energy Technology Data Exchange (ETDEWEB)

J. Blair Briggs; John D. Bess; Jim Gulliford

2011-09-01

Since the International Conference on Nuclear Criticality Safety (ICNC) 2007, the International Criticality Safety Benchmark Evaluation Project (ICSBEP) and the International Reactor Physics Experiment Evaluation Project (IRPhEP) have continued to expand their efforts and broaden their scope. Eighteen countries participated on the ICSBEP in 2007. Now, there are 20, with recent contributions from Sweden and Argentina. The IRPhEP has also expanded from eight contributing countries in 2007 to 16 in 2011. Since ICNC 2007, the contents of the 'International Handbook of Evaluated Criticality Safety Benchmark Experiments1' have increased from 442 evaluations (38000 pages), containing benchmark specifications for 3955 critical or subcritical configurations to 516 evaluations (nearly 55000 pages), containing benchmark specifications for 4405 critical or subcritical configurations in the 2010 Edition of the ICSBEP Handbook. The contents of the Handbook have also increased from 21 to 24 criticality-alarm-placement/shielding configurations with multiple dose points for each, and from 20 to 200 configurations categorized as fundamental physics measurements relevant to criticality safety applications. Approximately 25 new evaluations and 150 additional configurations are expected to be added to the 2011 edition of the Handbook. Since ICNC 2007, the contents of the 'International Handbook of Evaluated Reactor Physics Benchmark Experiments2' have increased from 16 different experimental series that were performed at 12 different reactor facilities to 53 experimental series that were performed at 30 different reactor facilities in the 2011 edition of the Handbook. Considerable effort has also been made to improve the functionality of the searchable database, DICE (Database for the International Criticality Benchmark Evaluation Project) and verify the accuracy of the data contained therein. DICE will be discussed in separate papers at ICNC 2011. The status of the

Analysis of safety culture components based on site interviews

International Nuclear Information System (INIS)

Ueno, Akira; Nagano, Yuko; Matsuura, Shojiro

2002-01-01

Safety culture of an organization is influenced by many factors such as employee's moral, safety policy of top management and questioning attitude among site staff. First this paper analyzes key factors of safety culture on the basis of site interviews. Then the paper presents a safety culture composite model and its applicability in various contexts. (author)

First Aid and Safety

Science.gov (United States)

... Staying Safe Videos for Educators Search English Español First Aid & Safety Keeping your child safe is your top ... do in an emergency, how to stock a first-aid kit, where to call for help, and more. ...

Telekommunikatsiooni TOP aastal 2003

Index Scriptorium Estoniae

2004-01-01

Telekommunikatsiooni TOP aastal 2003. Käibe TOP 10. Käibe kasvu TOP 10. Rentaabluse TOP 10. Kasumi TOP 10. Kasumi kasvu TOP 10. Omakapitali tootlikkuse TOP 10. Telekommunikatsioonifirmade üldandmed. Telekommunikatsioonifirmade finantsandmed

Jaekaubandusettevõtete TOP 70

Index Scriptorium Estoniae

2005-01-01

Jaekaubandusettevõtete TOP 70; Käibe TOP 25; Kasumi TOP 25; Käibe kasvu TOP 20; Kasumi kasvu TOP 20; Rentaabluse TOP 20; Omakapitali tootlikkuse TOP 20; Jaekaubandusettevõtete üld- ja finantsandmed

The top quark physics of the final flavor

CERN Document Server

Franklin, Melissa

1996-01-01

This will be a series of lectures concerning the recent discovery of the top quark. These lectures will cover things I have learned from hanging around proton anti-proton colliders for the past 15 years, including : Proton colliders, top quark production and decay kinematics.The D0 and CDF detectors : the finer points. Identifying W's and b quark jets. Jet spectroscopy : measuring masses with jets. Jet spectroscopy : measuring masses with jets. Scrutinizing events in which real W's are produced : the counting experiments with the CDF and D0 detectors at Fermilab. Checking the kinematics and measuring the mass and cross-section. Doing spot checks : is it a W, is there another W, is it a b, are they from top ? Seeing if top fits into the rest of the so-called Standard Model (circa 1995) My future

Measurement of Top Mass and Properties with the ATLAS Detector

CERN Multimedia

CERN. Geneva

2013-01-01

The extraordinary success of the LHC in delivering proton-proton collisions with large integrated luminosity allows the study of top-quark-enriched data samples with unprecedented statistics. This opens new possibilities for the assessment and further refinements of detector performance, and of data analysis tools. At the same time, different aspects of top-quark event modeling, as implemented in Monte Carlo simulations, can be tested and confronted with data with impressive precision. As an example, the description of the extra QCD radiation accompanying the top-anti-top system can be refined based on measurements. In this context, the experimental challenges and recent results on precision top-quark physics measurements within the ATLAS experiment are summarized and reviewed. In particular, the recent ATLAS top-quark mass result, obtained using a three dimensional template method, which allows the simultaneous determination of the top-quark mass together with a global jet energy scale factor (JSF), and a ...

Analysis of the impact of correlated benchmark experiments on the validation of codes for criticality safety analysis

International Nuclear Information System (INIS)

Bock, M.; Stuke, M.; Behler, M.

2013-01-01

The validation of a code for criticality safety analysis requires the recalculation of benchmark experiments. The selected benchmark experiments are chosen such that they have properties similar to the application case that has to be assessed. A common source of benchmark experiments is the 'International Handbook of Evaluated Criticality Safety Benchmark Experiments' (ICSBEP Handbook) compiled by the 'International Criticality Safety Benchmark Evaluation Project' (ICSBEP). In order to take full advantage of the information provided by the individual benchmark descriptions for the application case, the recommended procedure is to perform an uncertainty analysis. The latter is based on the uncertainties of experimental results included in most of the benchmark descriptions. They can be performed by means of the Monte Carlo sampling technique. The consideration of uncertainties is also being introduced in the supplementary sheet of DIN 25478 'Application of computer codes in the assessment of criticality safety'. However, for a correct treatment of uncertainties taking into account the individual uncertainties of the benchmark experiments is insufficient. In addition, correlations between benchmark experiments have to be handled correctly. For example, these correlations can arise due to different cases of a benchmark experiment sharing the same components like fuel pins or fissile solutions. Thus, manufacturing tolerances of these components (e.g. diameter of the fuel pellets) have to be considered in a consistent manner in all cases of the benchmark experiment. At the 2012 meeting of the Expert Group on 'Uncertainty Analysis for Criticality Safety Assessment' (UACSA) of the OECD/NEA a benchmark proposal was outlined that aimed for the determination of the impact on benchmark correlations on the estimation of the computational bias of the neutron multiplication factor (k eff ). The analysis presented here is based on this proposal. (orig.)

Measurements and searches with top quarks. Measurement of the top quark pair production cress section, the ratio of brnaching fractions and searches for new physics in the top quark sector with the D0 experiment

Energy Technology Data Exchange (ETDEWEB)

Peters, Yvonne

2008-08-15

In this thesis measurements and searches in the top quark sector have been presented. With about 0.9 fb{sup -1} of data collected by the D0 detector, the precise measurement of the top quark pair production cross section and the ratio of branching fractions R has been performed in the lepton plus jets final state. Simultaneously with R the top quark pair production cross section {sigma}(p anti p {yields} t anti t) . B{sup 2}(t {yields} W{sub q}) has been extracted. Furthermore, the top quark pair production cross section in the lepton plus jets, dilepton and tau plus lepton final states have been combined for a dataset of about 1 fb{sup -1}, resulting in {sigma}{sub t} {sub anti} {sub t} = 7.83{sup +093}{sub -0.82} (total) pb for a top quark mass of 175 GeV. Based on the cross section combination a global search for the charged Higgs boson in top quark decays in various t anti t final states has been performed. Last but not least, the simultaneous measurement of R and {sigma}{sub t} {sub anti} {sub t} was changed into a simultaneous measurement of {sigma}{sub t} {sub anti} {sub t} and the associated production of a Higgs boson and a top quark pair {sigma}{sub t} {sub anti} {sub tH} . B(H {yields} b anti b). The latter yields the first measurement of {sigma}{sub t} {sub anti} {sub tH} . B(H {yields} b anti b) at D0 and the currently best limits on {sigma}{sub t} {sub anti} {sub tH} . B(H {yields} b anti b) from the Tevatron. (orig.)

Boosted top production in ATLAS and CMS

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00237277; The ATLAS collaboration

2017-01-01

An overview of the boosted top production analyses using data collected by the ATLAS and CMS experiments at $\\sqrt{s}=$' 8 TeV and 13 TeV of proton-proton collisions at the LHC is presented. These analyses use techniques for the reconstruction of boosted objects to measure the production of top quarks at high transverse momenta. The measurements are optimized for the different final states and for different ranges of the transverse momenta of the particles involved, improving on measurements with traditional objects reconstruction based on the combination of resolved objects.

Safety of RBMK reactors: Major results and prospects

International Nuclear Information System (INIS)

Sidorenko, V.A.

1996-01-01

The paper considers the following issues: basic reasons for the advent of NPPs with RBMK reactors; the logic of identifying top-priority measures immediately after the accident; top-priority measures for improving the safety and reliability of NPPs with RBMK reactors; upgrading NPPs with RBMK reactors in compliance with the Norms; programmes for retrofitting and upgrading of NPPs of the ''Rosnergoatom'' Concern and progress with their implementation as of April 1996; the safety of RBMK plants and the programmes of its enhancement with regard to modern requirements in the light of national and international assessment; objective indicators of safety, reliability, and economic efficiency of NPPs with RBMK reactors; economics: rationale for continuing plants operation till the end of their design lifetime. 8 refs, 3 figs

Search for a light Higgs boson associated with a pair of top quarks in the Atlas experiment; Recherche d'un boson de Higgs leger produit en association avec une paire de quarks top dans l'experience ATLAS

Energy Technology Data Exchange (ETDEWEB)

Leveque, J

2003-06-01

One of the main goals of the ATLAS experiment is the search for the Higgs boson, the last missing ingredient of the standard model, and the studies of its properties. The experiment will be based at the future proton-proton collider LHC, whose first collisions are expected in 2007. The work presented in this thesis is dedicated to the search for a Higgs boson with a mass below 200 GeV/c{sup 2}, in the associated production channel pp {yields} ttH. The identification of jets containing b-hadrons is crucial for Higgs boson and top quark studies. The tagging performances of b-jets are studied in details in the ttH, H {yields} bb channel, in the most realistic conditions at start of data taking (reduced pixel detector, pile-up, detection inefficiencies). At 60% b-jet efficiency, light and c-jet rejections of 80% and 7% respectively are achieved. Whereas the discovery of the Higgs boson is expected to be relatively easy, the measurement of its parameters, in particular its couplings to fermions, is more involved. The possibility of observing the Higgs boson in the ttH, H {yields} WW(*) channel is investigated. This process is the only one to date leading to a direct measurement of the top quark Yukawa coupling in the mass range 130-200 GeV/c{sup 2}. For a Higgs boson of mass 160 GeV/c{sup 2}, a statistical precision of about 7% could be reached after three years of data taking at high luminosity. (author)

Liquid entrainment and off-take at the top of the pressurizer in the case of the actuation of safety depressurization system of APR1400

International Nuclear Information System (INIS)

Kim, Chang Hyun; No, Hee Cheon

2003-01-01

In order to determine the bleed capacity of Safety Depressurization System (SDS) of Advanced Power Reactor 1400 (APR1400) in case of Total Loss of Feed Water (TLOFW), we performed an experimental study of liquid entrainment and liquid off-take from the swelled two-phase mixture surface in a vessel. A total of 208 experimental data on the entrainment and off-take are obtained using a test vessel with the height of 2.0m and the inner diameter of 0.3m having a top break with diameter of 0.05m. Two-phase mixture levels are measured by the ultrasonic sensor within ? .77% with respect to the visual level data. Droplet entrainments are measured and compared with the existing pool entrainment data. The empirical correlation for the onset of off-take is developed in terms of the Froude number (Fr g ) at the break and non-dimensional inception height (h b /d). This correlation shows agreement with the present experimental data within ? 5%. The present off-take quality data is in agreement with Schrock's off-take quality correlation with the r.m.s. error of 15.8%. In the present experiment, droplet entrainment E fg strongly depends upon jg * /h * and is proportional to the 7 th power of jg * /h * in the same way as the off-take data

Ekspedeerimisettevõtete TOP 50

Index Scriptorium Estoniae

2006-01-01

Ilmunud ka: Delovõje Vedomosti : Transport i Logistika nr. 11, 29. nov. lk. 32-35. Ekspedeerimisettevõtete TOP. Vt. samas: Käibe TOP 10; Käibekasvu TOP 10; Kasumi TOP 10; Kasumikasvu TOP 10; Rentaabluse TOP 10; ROE TOP 10; Ekspedeerimisettevõtete üld- ja finantsandmed. Ajal. Delovõje Vedomosti : Transport i Logistika toodud ainult Ekspedeerimisettevõtete TOP 50

The Role of Top-down Attention in the Cocktail Party: Revisiting Cherry's Experiment after Sixty Years

DEFF Research Database (Denmark)

Marchegiani, Letizia; Karadogan, Seliz; Andersen, Taja

2011-01-01

We investigate the role of top-down task drive attention in the cocktail party problem. In a recently proposed computational model of top-down attention it is possible to simulate the cocktail party problem and make predictions about sensitivity to confounders under different levels of attention....... Based on such simulations we expect that under strong top-down attention pattern recognition is improved as the model can compensate for noise and confounders. We next investigate the role of temporal and spectral overlaps and speech intelligibility in humans, and how the presence of a task influences...... computational top-down attention model....

Lessons from feedback of safety operating experience for reactor physics

International Nuclear Information System (INIS)

Suchomel, J.; Rapavy, S.

1999-01-01

Analyses of events in WWER operations as a part of safety experience feedback provide a valuable source of lessons for reactor physics. Examples of events from Bohunice operation will be shown such as events with inadequate approach to criticality, positive reactivity insertions, expulsion of a control rod from shut-down reactor, problems with reactor protection system and control rods. (Authors)

Audiitorfirmade TOP aastal 2007

Index Scriptorium Estoniae

2008-01-01

Audiitorfirmade TOP 51. Vt. samas: Urve Vilk. Audiitoriteni pole majanduslangus jõudnud; Intervjuu I.S. Audiitorteenuste OÜ omaniku Irina Somovaga; Käibe TOP 10; Käibe kasvu TOP 10; Kasumi TOP 10; Kasumi kasvu TOP 10; Rentaabluse TOP 10; Omakapitali tootlikkuse TOP 10

Koolitusfirmade TOP aastal 2006

Index Scriptorium Estoniae

2007-01-01

Koolitusfirmade TOP. Vt. samas: Käibe TOP10; Käibe kasvu TOP 10; Kasumi TOP 10; Kasumi kasvu TOP 10; Rentaabluse TOP 10; Varade tootlikkuse TOP 10; Pille Rõivas. Võtmetegur meeskond; Vain & Partnerid: uudsus peitub sisus; Kristo Kiviorg. Teel Baltimaade koolitajate tippu

Preparing Safety Cases for Operating Outside Prescriptive Fatigue Risk Management Regulations.

Science.gov (United States)

Gander, Philippa; Mangie, Jim; Wu, Lora; van den Berg, Margo; Signal, Leigh; Phillips, Adrienne

2017-07-01

Transport operators seeking to operate outside prescriptive fatigue management regulations are typically required to present a safety case justifying how they will manage the associated risk. This paper details a method for constructing a successful safety case. The method includes four elements: 1) scope (prescriptive rules and operations affected); 2) risk assessment; 3) risk mitigation strategies; and 4) monitoring ongoing risk. A successful safety case illustrates this method. It enables landing pilots in 3-pilot crews to choose the second or third in-flight rest break, rather than the regulatory requirement to take the third break. Scope was defined using a month of scheduled flights that would be covered (N = 4151). These were analyzed in the risk assessment using existing literature on factors affecting fatigue to estimate the maximum time awake at top of descent and sleep opportunities in each break. Additionally, limited data collected before the new regulations showed that pilots flying at landing chose the third break on only 6% of flights. A prospective survey comparing subjective reports (N = 280) of sleep in the second vs. third break and fatigue and sleepiness ratings at top of descent confirmed that the third break is not consistently superior. The safety case also summarized established systems for fatigue monitoring, risk assessment and hazard identification, and multiple fatigue mitigation strategies that are in place. Other successful safety cases have used this method. The evidence required depends on the expected level of risk and should evolve as experience with fatigue risk management systems builds.Gander P, Mangie J, Wu L, van den Berg M, Signal L, Phillips A. Preparing safety cases for operating outside prescriptive fatigue risk management regulations. Aerosp Med Hum Perform. 2017; 88(7):688-696.

Validating Virtual Safety Stock Effectiveness through Simulation

Directory of Open Access Journals (Sweden)

Maria Elena Nenni

2013-08-01

safety stock effectiveness through simulation in an inventory system using a base stock policy with periodic reviews and backorders. This approach can be useful for researchers as well as practitioners who want to model the behaviour of an inventory system under uncertain conditions and verify the opportunity for setting up a virtual safety stock on top of, or instead of, the traditional physical safety stock.

Sports Dehydration Safety Tips

Science.gov (United States)

Sports Dehydration Safety Tips Everything you need to know to keep your kids safe from dehydration when playing sports. To keep kids in top ... to stay hydrated by drinking plenty of fluids. Dehydration occurs when a body loses more water than ...

Encouraging top-down attention in visual search:A developmental perspective.

Science.gov (United States)

Lookadoo, Regan; Yang, Yingying; Merrill, Edward C

2017-10-01

Four experiments are reported in which 60 younger children (7-8 years old), 60 older children (10-11 years old), and 60 young adults (18-25 years old) performed a conjunctive visual search task (15 per group in each experiment). The number of distractors of each feature type was unbalanced across displays to evaluate participants' ability to restrict search to the smaller subset of features. The use of top-down attention processes to restrict search was encouraged by providing external aids for identifying and maintaining attention on the smaller set. In Experiment 1, no external assistance was provided. In Experiment 2, precues and instructions were provided to focus attention on that subset. In Experiment 3, trials in which the smaller subset was represented by the same feature were presented in alternating blocks to eliminate the need to switch attention between features from trial to trial. In Experiment 4, consecutive blocks of the same subset features were presented in the first or second half of the experiment, providing additional consistency. All groups benefited from external support of top-down attention, although the pattern of improvement varied across experiments. The younger children benefited most from precues and instruction, using the subset search strategy when instructed. Furthermore, younger children benefited from blocking trials only when blocks of the same features did not alternate. Older participants benefited from the blocking of trials in both Experiments 3 and 4, but not from precues and instructions. Hence, our results revealed both malleability and limits of children's top-down control of attention.

Comparison of crop yield sensitivity to ozone between open-top chamber and free-air experiments.

Science.gov (United States)

Feng, Zhaozhong; Uddling, Johan; Tang, Haoye; Zhu, Jianguo; Kobayashi, Kazuhiko

2018-02-02

Assessments of the impacts of ozone (O 3 ) on regional and global food production are currently based on results from experiments using open-top chambers (OTCs). However, there are concerns that these impact estimates might be biased due to the environmental artifacts imposed by this enclosure system. In this study, we collated O 3 exposure and yield data for three major crop species-wheat, rice, and soybean-for which O 3 experiments have been conducted with OTCs as well as the ecologically more realistic free-air O 3 elevation (O 3 -FACE) exposure system; both within the same cultivation region and country. For all three crops, we found that the sensitivity of crop yield to the O 3 metric AOT40 (accumulated hourly O 3 exposure above a cut-off threshold concentration of 40 ppb) significantly differed between OTC and O 3 -FACE experiments. In wheat and rice, O 3 sensitivity was higher in O 3 -FACE than OTC experiments, while the opposite was the case for soybean. In all three crops, these differences could be linked to factors influencing stomatal conductance (manipulation of water inputs, passive chamber warming, and cultivar differences in gas exchange). Our study thus highlights the importance of accounting for factors that control stomatal O 3 flux when applying experimental data to assess O 3 impacts on crops at large spatial scales. © 2018 John Wiley & Sons Ltd.

Safety Research Experiment Facility Project. Conceptual design report. Volume II. Building and facilities

International Nuclear Information System (INIS)

1975-12-01

The conceptual design of Safety Research Experiment Facility (SAREF) site system includes a review and evaluation of previous geotechnical reports for the area where SAREF will be constructed and the conceptual design of access and in-plant roads, parking, experiment-transport-vehicle maneuvering areas, security fencing, drainage, borrow area development and restoration, and landscaping

Autotranspordi TOP aastal 2007

Index Scriptorium Estoniae

2008-01-01

TOP 50. Vt. samas: Käibe TOP 10; Käibe kasvu TOP 10; Kasumi TOP 10; Kasumi kasvu TOP 10; Rentaabluse TOP 10; Omakapitali tootlikkuse TOP 10; Marika Roomere. Täisteenuse pakkumine kergitas tulemusi; Jupiter Plus otsib järjest uusi kasvuvõimalusi; EST-Trans Kaubaveod teenib kasumit toiduvedamisega

Properties of the Top Quark

Energy Technology Data Exchange (ETDEWEB)

Wicke, Daniel; /Wuppertal U., Dept. Math.

2009-08-01

Tevatron experiments CDF and D0 and was the last of the quarks to be discovered. As the partner of the bottom quark the top quark is expected to have quantum numbers identical to that of the other known up-type quarks. Only the mass is a free parameter. We now know that it is more than 30 times heavier than the next heaviest quark, the bottom quark. Thus, within the Standard Model all production and decay properties are fully defined. Having the complete set of quarks further allows to verify constraints that the Standard Model puts on the sum of all quarks or particles. This alone is reason enough to experimentally study the top quark properties. The high value of the top quark mass and its closeness to the electroweak scale has inspired people to speculate that the top quark could have a special role in the electroweak symmetry breaking. Confirming the expected properties of the top quark experimentally establishes the top quark as we expect it to be. Any deviation from the expectations gives hints to new physics that may help to solve the outstanding questions. In this review the recent results on top quark properties obtained by the Tevatron experiments CDF and D0 are summarized. At the advent of the LHC special emphasis is given to the basic measurement methods and the dominating systematic uncertainties. After a short introduction to the Standard Model and the experimental environment in the remainder of this chapter, Chapter 2 describes the current status of top quark mass measurements. Then measurments of interaction properties are described in Chapter 3. Finally, Chapter 4 deals with analyses that consider hypothetical particles beyond the Standard Model in the observed events.

Properties of the Top Quark

International Nuclear Information System (INIS)

Wicke, Daniel

2009-01-01

Tevatron experiments CDF and D0 and was the last of the quarks to be discovered. As the partner of the bottom quark the top quark is expected to have quantum numbers identical to that of the other known up-type quarks. Only the mass is a free parameter. We now know that it is more than 30 times heavier than the next heaviest quark, the bottom quark. Thus, within the Standard Model all production and decay properties are fully defined. Having the complete set of quarks further allows to verify constraints that the Standard Model puts on the sum of all quarks or particles. This alone is reason enough to experimentally study the top quark properties. The high value of the top quark mass and its closeness to the electroweak scale has inspired people to speculate that the top quark could have a special role in the electroweak symmetry breaking. Confirming the expected properties of the top quark experimentally establishes the top quark as we expect it to be. Any deviation from the expectations gives hints to new physics that may help to solve the outstanding questions. In this review the recent results on top quark properties obtained by the Tevatron experiments CDF and D0 are summarized. At the advent of the LHC special emphasis is given to the basic measurement methods and the dominating systematic uncertainties. After a short introduction to the Standard Model and the experimental environment in the remainder of this chapter, Chapter 2 describes the current status of top quark mass measurements. Then measurments of interaction properties are described in Chapter 3. Finally, Chapter 4 deals with analyses that consider hypothetical particles beyond the Standard Model in the observed events.

Studies of top quark production at D0

Energy Technology Data Exchange (ETDEWEB)

Gerber, Cecilia E.; /Illinois U., Chicago

2011-07-01

I present recent results on top quark production in pp collisions at a center of mass energy of 1.96 TeV. The studies were performed by the D0 collaboration using approximately 5 fb{sup -1} of data taken during Run II at the Fermilab Tevatron accelerator. The top quark is the heaviest known elementary particle and completes the quark sector of the three-generation structure of the standard model (SM). It differs from the other quarks not only by its much larger mass, but also by its lifetime which is too short to build hadronic bound states. The SM predicts that top quarks are created via two independent production mechanisms at hadron colliders. The primary mode, in which a t{bar t} pair is produced from a gtt vertex via the strong interaction, was used by the D0 and CDF collaborations to establish the existence of the top quark in 1995. The second production mode of top quarks at hadron colliders is the electroweak production of a single top quark from a Wtb vertex. The predicted cross section for single top quark production is about half that of t{bar t} pairs but the signal-to-background ratio is much worse; observation of single top quark production has therefore until recently been impeded by its low rate and difficult background environment compared to the top pair production. In the following sections I will present results for the measurement of the t{bar t} pair and the single top quark production cross section using respectively 5.3 fb{sup -1} and 5.4 fb{sup -1} of data taken by the D0 experiment.

Drug research methodology. Volume 1, The alcohol-highway safety experience and its applicability to other drugs

Science.gov (United States)

1980-03-01

This report presents the findings of a workshop concerning the alcohol and highway safety experience, which includes research efforts to define the drinking-driving problem and societal responses to reduce the increased highway safety risk attributab...

Status of the DO top search

International Nuclear Information System (INIS)

Li-Demarteau, Q.

1994-09-01

Preliminary new results on the top quark search with the DO experiment in bar pp collisions at √s = 1.8 TeV for an integrated luminosity of 15.2 ± 1.8 pb -1 are reported. In this new analysis, which is optimized for high mass top search, a total of seven candidate events in the electron and muon dilepton decay channels (t bar t → eμ, ee and μμ), single lepton decay channels (t bar t → e + jets and t bar t → μ + jets) without b tagging and single electron decay channel (t bar t → e + jets) with b tagging have been observed. The estimated background is 4.7 ± 1.0 events. If we assume the top quark has a mass of 180 GeV/c 2 , a t bar t production cross section of 3.2 ± 3.9 pb with upper limit of 13 pb at 95% C.L. is obtained

Application of fractal theory to top-coal caving

International Nuclear Information System (INIS)

Xie, H.; Zhou, H.W.

2008-01-01

The experiences of underground coal mining in China show that coal in a thick hard coal seam with a hard roof, the so-called 'double hard coal seam', is difficult to be excavated by top-coal caving technique. In order to solve the problem, a top-coal weakening technique is proposed in this paper. In the present study, fractal geometry provides a new description of the fracture mechanism for blasting. By means of theoretical analysis of the relationship between the fractal dimension of blasting fragments and the dynamite specific energy, a mechanical model for describing the size distribution of top-coal and the dissipation of blasting energy is proposed. The theoretical results are in agreement with laboratory and in situ test results. Moreover, it is shown that the fractal dimension of coal fragments can be used as an index for optimizing the blasting parameters for a top-coal weakening technique

EXPERIENCE NETWORKING UNIVERSITY OF EDUCATION TRAINING MASTERS SAFETY OF LIFE

Directory of Open Access Journals (Sweden)

Elvira Mikhailovna Rebko

2016-02-01

Full Text Available The article discloses experience networking of universities (Herzen State Pedagogical University and Sakhalin State University in the development and implementation of joint training programs for master’s education in the field of life safety «Social security in the urban environment». The novelty of the work is to create a schematic design of basic educational training program for master’s education in the mode of networking, and to identify effective instructional techniques and conditions of networking.Purpose – present the results of the joint development of a network of the basic educational program (BEP, to identify the stages of networking, to design a generalized scheme of development and implementation of a network of educational training program for master’s education in the field of life safety.Results generalized model of networking partner institutions to develop and implement the basic educational program master.Practical implications: the education process for Master of Education in the field of health and safety in Herzen State Pedagogical University and Sakhalin State University.

Koolitusfirmade TOP aastal 2007

Index Scriptorium Estoniae

2008-01-01

Koolitusfirmade TOP. Vt. samas: Käibe TOP 10; Käibekasvu TOP 10; Kasumi TOP 10; Kasumi kasvu TOP 10; Rentaabluse TOP 10; Omakapitali tootlikkuse TOP 10; Signe Sillasoo. Invicta tahab lähiaastail laieneda Eestis ja mujalgi; Ketlin Priilinn. Addenda kasutas ära majanduse soodsa seisu. Kommenteerib Heli Sõmer. Juhtide hoiakute muutmisega tõus esikolmikusse

Occupational safety in the petroleum industry

Energy Technology Data Exchange (ETDEWEB)

Elsner, W

1987-03-01

The original technique-oriented accident prevention today has grown to a comprehensive occupational workers protection system. Modern occupational safety requires latest strategies. Side by side with technical and organizational measures we see duties for all superiors directed to plant related occupational safety. These new principles of leadership on the basis of occupational safety policies from top management require equivalent tactics to cause change in behaviour of the employees. Such a not only formulated but also accepted safety strategy is extremely clear by its positive results in the petroleum industry.

Safety advice sheets

CERN Multimedia

HSE Unit

2013-01-01

You never know when you might be faced with questions such as: when/how should I dispose of a gas canister? Where can I find an inspection report? How should I handle/store/dispose of a chemical substance…?   The SI section of the DGS/SEE Group is primarily responsible for safety inspections, evaluating the safety conditions of equipment items, premises and facilities. On top of this core task, it also regularly issues “Safety Advice Sheets” on various topics, designed to be of assistance to users but also to recall and reinforce safety rules and procedures. These clear and concise sheets, complete with illustrations, are easy to display in the appropriate areas. The following safety advice sheets have been issued so far: Other sheets will be published shortly. Suggestions are welcome and should be sent to the SI section of the DGS/SEE Group. Please send enquiries to general-safety-visits.service@cern.ch.

Top quark property measurements in single top

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00386283; The ATLAS collaboration

2016-01-01

A review of the recent results on measurements of top quark properties in single top quark processes, performed at the LHC by ATLAS and CMS is presented. The measurements are in good agreement with predictions and no deviations from Standard Model expectations have been observed.

AAA Foundation for Traffic Safety

Science.gov (United States)

... of Top Deadly Mistakes Made by Teen Drivers -- AAA AAA: Road debris causes avoidable crashes, deaths Save the ... and 500 deaths! Foundation News Stay Tuned New AAA Foundation for Traffic Safety website coming Fall 2017 ...

Results on top-quark physics and top-quark-like signatures by CMS

Science.gov (United States)

Chabert, Eric; CMS Collaboration

2017-07-01

This report reviews the results obtained by the CMS Collaboration on top quark physics, focusing on the latest ones based on p-p collisions provided by the LHC at \\sqrt{s}=13{{TeV}} during Run II. It covers measurements of single-top, top quark pairs and associated productions as well as measurements of top quark properties. Finally several beyond the standard model searches involving top quark in the final states are presented, such as searches for supersymmetry in the third generation, heavy resonances decaying into a top quark pair, or dark matter produced in association to a single-top or a top quark pair.

Performance improvement of the Annular Core Pulse Reactor for reactor safety experiments

International Nuclear Information System (INIS)

Reuscher, J.A.; Pickard, P.S.

1976-01-01

The Annular Core Pulse Reactor (ACPR) is a TRIGA type reactor which has been in operation at Sandia Laboratories since 1967. The reactor is utilized in a wide variety of experimental programs which include radiation effects, neutron radiography, activation analysis, and fast reactor safety. During the past several years, the ACPR has become an important experimental facility for the United States Fast Reactor Safety Research Program and questions of interest to the safety of the LMFBR are being addressed. In order to enhance the capabilities of the ACPR for reactor safety experiments, a project to improve the performance of the reactor was initiated. It is anticipated that the pulse fluence can be increased by a factor of 2.0 to 2.5 utilizing a two-region core concept with high heat capacity fuel elements around the central irradiation cavity. In addition, the steady-state power of the reactor will be increased by about a factor of two. The new features of the improvements are described

Beam Loss Simulation Studies for ALS Top-Off Operation

CERN Document Server

Nishimura, Hiroshi; Robin, David; Steier, Christoph

2005-01-01

The ALS is planning to operate with top-off injection at higher beam currents and smaller vertical beam size. As part of a radiation safety study for top-off, we carried out two kinds of tracking studies: (1) to confirm that the injected beam cannot go into users' photon beam lines, and (2) to control the location of beam dump when the storage ring RF is tripped. (1) is done by tracking electrons from a photon beam line to the injection sector inversely by including the magnetic field profiles, varying the field strength with geometric aperture limits to conclude that it is impossible. (2) is done by tracking an electron with radiation in the 6-dim space for different combinations of vertical scrapers for the realistic lattice with errors.

New Methods for Top-Quark Mass Measurements at the LHC

CERN Document Server

Stieger, Benjamin

2016-01-01

Several recent new measurements of the top-quark mass that use alternative observables and reconstruction techniques are presented, performed by the ATLAS and CMS collaborations at the CERN LHC. Alternative observables can help provide insight by presenting different systematic sensitivities and by constraining prevailing systematic uncertainties of standard measurements, such as jet energy calibrations. Furthermore, the top-quark mass is extracted from theoretically well-defined observables, such as the inclusive production cross section for top quark pairs. Finally, the mass is measured in event topologies dominated by electroweak-mediated single top production by both experiments. The results of different techniques and production modes are found to be consistent with what is obtained in standard measurements.

Safety in the Utilization and Modification of Research Reactors. Specific Safety Guide

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-07-15

This Safety Guide is a revision of Safety Series No. 35-G2 on safety in the utilization and modification of research reactors. It provides recommendations on meeting the requirements for the categorization, safety assessment and approval of research reactor experiments and modification projects. Specific safety considerations in different phases of utilization and modification projects are covered, including the pre-implementation, implementation and post-implementation phases. Guidance is also provided on the operational safety of experiments, including in the handling, dismantling, post-irradiation examination and disposal of experimental devices. Examples of the application of the safety categorization process for experiments and modification projects and of the content of the safety analysis report for an experiment are also provided. Contents: 1. Introduction; 2. Management system for the utilization and modification of a research reactor; 3. Categorization, safety assessment and approval of an experiment or modification; 4. Safety considerations for the design of an experiment or modification; 5. Pre-implementation phase of a modification or utilization project; 6. Implementation phase of a modification or utilization project; 7. Post-implementation phase of a utilization or modification project; 8. Operational safety of experiments at a research reactor; 9. Safety considerations in the handling, dismantling, post-irradiation examination and disposal of experimental devices; 10. Safety aspects of out-of-reactor-core installations; Annex I: Example of a checklist for the categorization of an experiment or modification at a research reactor; Annex II: Example of the content of the safety analysis report for an experiment at a research reactor; Annex III: Examples of reasons for a modification at a research reactor.

Safety in the Utilization and Modification of Research Reactors. Specific Safety Guide

International Nuclear Information System (INIS)

2012-01-01

This Safety Guide is a revision of Safety Series No. 35-G2 on safety in the utilization and modification of research reactors. It provides recommendations on meeting the requirements for the categorization, safety assessment and approval of research reactor experiments and modification projects. Specific safety considerations in different phases of utilization and modification projects are covered, including the pre-implementation, implementation and post-implementation phases. Guidance is also provided on the operational safety of experiments, including in the handling, dismantling, post-irradiation examination and disposal of experimental devices. Examples of the application of the safety categorization process for experiments and modification projects and of the content of the safety analysis report for an experiment are also provided. Contents: 1. Introduction; 2. Management system for the utilization and modification of a research reactor; 3. Categorization, safety assessment and approval of an experiment or modification; 4. Safety considerations for the design of an experiment or modification; 5. Pre-implementation phase of a modification or utilization project; 6. Implementation phase of a modification or utilization project; 7. Post-implementation phase of a utilization or modification project; 8. Operational safety of experiments at a research reactor; 9. Safety considerations in the handling, dismantling, post-irradiation examination and disposal of experimental devices; 10. Safety aspects of out-of-reactor-core installations; Annex I: Example of a checklist for the categorization of an experiment or modification at a research reactor; Annex II: Example of the content of the safety analysis report for an experiment at a research reactor; Annex III: Examples of reasons for a modification at a research reactor.

[Experience feedback committee: a method for patient safety improvement].

Science.gov (United States)

François, P; Sellier, E; Imburchia, F; Mallaret, M-R

2013-04-01

An experience feedback committee (CREX, Comité de Retour d'EXpérience) is a method which contributes to the management of safety of care in a medical unit. Originally used for security systems of civil aviation, the method has been adapted to health care facilities and successfully implemented in radiotherapy units and in other specialties. We performed a brief review of the literature for studies reporting data on CREX established in hospitals. The review was performed using the main bibliographic databases and Google search results. The CREX is designed to analyse incidents reported by professionals. The method includes monthly meetings of a multi-professional committee that reviews the reported incidents, chooses a priority incident and designates a "pilot" responsible for investigating the incident. The investigation of the incident involves a systemic analysis method and a written synthesis presented at the next meeting of the committee. The committee agrees on actions for improvement that are suggested by the analysis and follows their implementation. Systems for the management of health care, including reporting systems, are organized into three levels: the medical unit, the hospital and the country as a triple loop learning process. The CREX is located in the base level, short loop of risk management and allows direct involvement of care professionals in patient safety. Safety of care has become a priority of health systems. In this context, the CREX can be a useful vehicle for the implementation of a safety culture in medical units. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Direct measurement of the top quark mass in $p\\bar p$ collisions at D0

Energy Technology Data Exchange (ETDEWEB)

Brandt, Oleg [Kirchhoff Inst. Phys.

2017-10-11

The mass of the top quark is a fundamental parameter of the Standard Model and has to be determined experimentally. In these proceedings, I review recent direct measurements of the top quark mass in $p\\bar p$ collisions at $\\sqrt s=1.96$ TeV recorded by the D0 experiment at the Tevatron. The measurements are performed in final states containing one and two charged leptons. I will present the legacy combination of all top quark mass measurements from the D0 experiment and their combination with results from the CDF experiment. A relative precision of down to 0.3\\% is attained.

Top quark physics in ATLAS (CORFU 2014)

CERN Document Server

Moreno Llácer, M; The ATLAS collaboration

2014-01-01

The top quark is the heaviest elementary particle observed to date. Being heavier than a W boson, it is the only quark that decays weakly, i.e. into a real W boson and a b quark, before hadronization can occur. In addition, it is the only quark whose Yukawa coupling to the Higgs boson is order of unity. For these reasons the top quark plays a special role in the Standard Model of Particle Physics and in many of its extensions. An accurate knowledge of its properties (mass, couplings, production cross section, decay branching ratios, etc.) can bring key information on fundamental interactions at the electroweak breaking scale and beyond. In this talk the latest measurements of the characteristics of the top quark carried out in the ATLAS experiment at the Large Hadron Collider are presented.

Experience on environmental qualification of safety-related components for Darlington Nuclear Generating Station

International Nuclear Information System (INIS)

Yu, A.S.; Kukreti, B.M.

1987-01-01

The proliferation of Nuclear Power Plant safety concerns has lead to increasing attention over the Environmental Qualification (EQ) of Nuclear Power Plant Safety-Related Components to provide the assurance that the safety related equipment will meet their intended functions during normal operation and postulated accident conditions. The environmental qualification of these components is also a Licensing requirement for Darlington Nuclear Generating Station. This paper provides an overview of EQ and the experience of a pilot project, in the qualification of the Main Moderator System safety-related functions for the Darlington Nuclear Generating Station currently under construction. It addresses the various phases of qualification from the identification of the EQ Safety-Related Components List, definition of location specific service conditions (normal, adbnormal and accident), safety-related functions, Environmental Qualification Assessments and finally, an EQ system summary report for the Main Moderator System. The results of the pilot project are discussed and the methodology reviewed. The paper concludes that the EQ Program developed for Darlington Nuclear Generating Station, as applied to the qualification of the Main Moderator System, contained all the elements necessary in the qualification of safety-related equipment. The approach taken in the qualification of the Moderator safety-related equipment proves to provide a sound framework for the qualification of other safety-related components in the station

Cryogenic safety organisation at CERN

CERN Multimedia

CERN. Geneva

2016-01-01

With Safety being a top priority of CERN’s general policy, the Organisation defines and implements a Policy that sets out the general principles governing Safety at CERN. To the end of the attainment of said Safety objectives, the organic units (owners/users of the equipment) are assigned the responsibility for the implementation of the CERN Safety Policy at all levels of the organization, whereas the Health and Safety and Environmental Protection Unit (HSE) has the role of providing assistance for the implementation of the Safety Policy, and a monitoring role related to the implementation of continuous improvement of Safety, compliance with the Safety Rules and the handling of emergency situations. This talk will elaborate on the roles, responsibilities and organisational structure of the different stakeholders within the Organization with regards to Safety, and in particular to cryogenic safety. The roles of actors of particular importance such as the Cryogenic Safety Officers (CSOs) and the Cryogenic Sa...

Recent Results on Top Physics in CMS

CERN Multimedia

CERN. Geneva

2012-01-01

Top physics is a pillar of the physics programme at the LHC. It involves precision measurements, leading to constraints on standard model parameters, as well as many measurements of observables sensitive to new physics. In this seminar, an overview of measurements performed by the CMS experiment in the domain of top physics will be presented, based on pp data collected in 2011 at a center-of-mass energy of 7 TeV. The results will be compared to expectations from theory. Emphasis in will be given to more recent results and to the treatment of systematic uncertainties.

Top and Electroweak Measurements at the Tevatron

Energy Technology Data Exchange (ETDEWEB)

Bartos, P. [Comenius U.

2016-01-01

In this report, we summarize the latest results of the top-quark mass and electroweak measurements from the Tevatron. Since the world combination of top-quark mass measurements was done, CDF and D0 experiments improved the precision of several results. Some of them reach the relative precition below 1% for a single measurement. From the electroweak results, we report on the WW and WZ production cross section, measurements of the weak mixing angle and indirect measurements of W boson mass. The Tevatron results of the weak mixing angle are still the most precise ones of hadron colliders.

The CERN Detector Safety System for the LHC Experiments

CERN Document Server

Lüders, S; Morpurgo, G; Schmeling, S

2003-01-01

The Detector Safety System (DSS), currently being developed at CERN under the auspices of the Joint Controls Project (JCOP), will be responsible for assuring the protection of equipment for the four LHC experiments. Thus, the DSS will require a high degree of both availability and reliability. After evaluation of various possible solutions, a prototype is being built based on a redundant Siemens PLC front-end, to which the safety-critical part of the DSS task is delegated. This is then supervised by a PVSS SCADA system via an OPC server. The PLC front-end is capable of running autonomously and of automatically taking predefined protective actions whenever required. The supervisory layer provides the operator with a status display and with limited online reconfiguration capabilities. Configuration of the code running in the PLCs will be completely data driven via the contents of a "Configuration Database". Thus, the DSS can easily adapt to the different and constantly evolving requirements of the LHC experimen...

Safety concerns for superconducting magnets of upcoming fusion experiments

International Nuclear Information System (INIS)

Turner, L.R.

1983-01-01

-Several fusion experiments being constructed (Tore Supra) or contemplated (DCT 8, Alcator DCT) feature superconducting coils. These coils introduce the following safety concerns: 1. Internally Cooled Conductor (ICC). ICC's are found to be highly stable against short heat pulses, even when the coolant is stagnant or moving at low steady-state velocity. However, a large heat pulse is certain to quench the conductor. Thus, determining the stability limits is vital. 2. Helium II Cooling. Helium II has both unique advantages as a coolant and unique safety problems. 3. Shorted Turns. In magnets with shorts from operational accidents, the current can switch back and forth between the short and the shorted turns, as those alternatively go normal and superconducting. 4. Hybrid Superconducting-Normal Conducting Coil System. The possibility of unequal currents in the different magnets and thus of unexpected forces on the superconducting magnets is much greater than for an all-superconducting system. Analysis of these problems are presented

Reactor physics experiment plan using TCA

Energy Technology Data Exchange (ETDEWEB)

Shimada, Shoichiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

2000-06-01

The Reduced-Moderation Water Reactor (RMWR) is one of the next generation water-cooled reactors, which aims at effective utilization of uranium resource, high burn-up, long operation cycle, and plutonium multi-recycle. For verification of the feasibility, negative void reactivity coefficient and conversion ratio more than 1.0 must be confirmed. This report is to plan critical experiments using TCA in JAERI. Critical Experiments performed so far in Europe and Japan are reviewed, and no useful data are available for RMWR development. Critical experiments using TCA (Tank Type Critical Assembly) in JAERI are planned. MOX fuel rods should be prepared for the experiments and some modifications of equipment are needed for use of MOX fuel rods. This report describes the preliminary plan of physics experiments. The number of MOX-fuel rods used in the experiments is obtained by calculations and modification of the equipment for the experiments are shown. New MOX fuel and UO{sub 2} fuel rods are necessary for the RMWR critical experiments. Number of MOX fuel rods is 1000 for Plutonium fissile enrichment of 5 wt%, 1000 for 10 wt%, 1500 for 15 wt% and 500 for 20 wt%, respectively. Depleted UO{sub 2} fuel rods for blanket/buffer region are 4000. Driver fuel rods of 4.9 wt% UO{sub 2} are 3000. Modification of TCA facility is requested to treat the large amount of MOX fuels from safety point of view. Additional shielding device at the top of the tank for loading the MOX fuels and additional safety plates to ensure safety are requested. The core is divided into two regions by inserting an inner tank to avoid criticality in MOX region only. The test region is composed by MOX fuel rods in the inner tank. Criticality is established by UO{sub 2} driver fuel rods outside of the inner tank. (Tsuchihashi, K.)

Status of the top quark: Top production cross section and top properties

Energy Technology Data Exchange (ETDEWEB)

Boisvert, V.; /Rochester U.

2006-08-01

This report describes the latest cross section and property measurements associated with the top quark at the Tevatron Run II. The largest data sample used is 760 pb{sup -1} of integrated luminosity. Due to its large mass, the top quark might be involved in the process of electroweak symmetry breaking, making it a useful probe for signs of new physics.

8th International Workshop on Top Quark Physics

CERN Document Server

2015-01-01

This workshop, at its 8th edition, will bring together the community of experimental and theoretical physicists working on top quark physics, 20 years after its first discovery, and at the beginning of the exploration of the new energy regime at the Large Hadron Collider. The workshop will provide a comprehensive overview of the latest results from the LHC and Tevatron experiments as well as the most recent theoretical developments and an outlook on top-quark physics at future colliders. The programme will consist of plenary presentations, a poster session and 'question and answers' sessions, targeted for young researchers. A significant fraction of the workshop time will be devoted to discussions. The goal of the workshop is to provide a comprehensive picture of top-quark physics and a forum where experimentalists and theorists can discuss the interpretation of top quark results and plan future measurements. The venue will take place in the Hotel Continental Terme, Ischia, the largest island in the bay of Na...

Flipped Top-Down is Systematic Bottom-Up

NARCIS (Netherlands)

Zaytsev, V.; Sturm, A.; Clark, T.

2016-01-01

The paper presents an experience report in course design for a versatile group of computer science students where their needs were surfaced and met by the combination of strict top-down exposure to course material and the flipped classroom model of lecturing.

Reisifirmade TOP 40 aastal 2002

Index Scriptorium Estoniae

2003-01-01

Reisifirmade TOP 40 aastal 2002. Reisifirmade TOP-i esikümme. Käibe TOP 40. Kasumi TOP 40. Käibe kasvu TOP 20. Kasumi kasvu TOP 20. Rentaabluse TOP 20. Omakapitali tootlikkuse TOP 20. Reisifirmade üldandmed. Reisifirmade finantsandmed. Tehnilise käibe alusel arvutatud edetabelid: Reisifirmade TOP 25; Käibe TOP 40; Rentaabluse TOP 10; Käibe kasvu TOP 10

Current MitraClip experience, safety and feasibility in the Netherlands

OpenAIRE

Rahhab, Z.; Kortlandt, F.A.; Velu, J.F.; Schurer, R.A.J.; Delgado, V.; Tonino, P.; Boven, A.J. van; Branden, B.J.L. Van den; Kraaijeveld, A.O.; Voskuil, M.; Hoorntje, J.; Wely, M.H. van; Houwelingen, K. van; Bleeker, G.B.; Rensing, B.

2017-01-01

PURPOSE: Data on MitraClip procedural safety and efficacy in the Netherlands are scarce. We aim to provide an overview of the Dutch MitraClip experience. METHODS: We pooled anonymised demographic and procedural data of 1151 consecutive MitraClip patients, from 13 Dutch hospitals. Data was collected by product specialists in collaboration with local operators. Effect on mitral regurgitation was intra-procedurally assessed by transoesophageal echocardiography. Technical success and device succe...

Teen worker safety training: methods used, lessons taught, and time spent.

Science.gov (United States)

Zierold, Kristina M

2015-05-01

Safety training is strongly endorsed as one way to prevent teens from performing dangerous tasks at work. The objective of this mixed methods study was to characterize the safety training that teenagers receive on the job. From 2010 through 2012, focus groups and a cross-sectional survey were conducted with working teens. The top methods of safety training reported were safety videos (42 percent) and safety lectures (25 percent). The top lessons reported by teens were "how to do my job" and "ways to spot hazards." Males, who were more likely to do dangerous tasks, received less safety training than females. Although most teens are getting safety training, it is inadequate. Lessons addressing safety behaviors are missing, training methods used are minimal, and the time spent is insignificant. More research is needed to understand what training methods and lessons should be used, and the appropriate safety training length for effectively preventing injury in working teens. In addition, more research evaluating the impact of high-quality safety training compared to poor safety training is needed to determine the best training programs for teens. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Naisjuhtidega ettevõtete TOP 100

Index Scriptorium Estoniae

2004-01-01

Naisjuhtidega ettevõtete TOP 100. Käibe TOP 20. Käibe kasvu TOP 20. Kasumi TOP 20. Kasumi kasvu TOP 20. Rentaabluse TOP 20. Omakapitali tootlikkuse TOP 20. Riigi- ja kohaliku omavalitsuse asutuste naisjuhtide TOP 25. Riigi- ja kohaliku omavalitsuse asutuste eelarve TOP 25. Riigi- ja kohaliku omavalitsuse asutuste töötajate arvu TOP 25. Riigi- ja kohaliku omavalitsuse asutuste naisjuhtide palga TOP 25

Experience in the development and practical use of working control levels for radiation safety

International Nuclear Information System (INIS)

Epishin, A.V.

1981-01-01

The experience of development and practical use of working control levels (WCL) of radiation safety in the Gorky region, is discussed. WCL are introduced by ''Radiation Safety Guides'' (RSG-76) and have great practical importance. Regional control levels of radiation safety are determined for certain types of operations implying radioactive hazard and differentiated according to the types of sources applied and types of operation. Dose rates, radioactive contamination of operating surfaces, skin, air and waste water are subject to normalization. Limits of individual radiation doses specified according to operation categories are included. 10 tables of regional WCL indices are developed [ru

Measurement of top quark polarization in top-antitop lepton+jets final states at DØ

Energy Technology Data Exchange (ETDEWEB)

Augsten, Kamil [Czech Technical Univ., Prague (Czech Republic)

2017-01-01

This thesis presents a measurement of the top quark polarization in the $t\\overline{t}$ events produced in $p\\overline{p}$ collisions at $\\sqrt{s}=1.96$ TeV using data corresponding to 9.7 fb$^{-1}$ of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The final states used in the measurement contain one lepton and at least three jets. The polarization is measured using the angular distribution of leptons along three different axes: the beam axis, the helicity axis, and the transverse axis normal to the $t\\overline{t}$ production plane. This is the first measurement of top quark polarization at the Tevatron Collider in lepton+jets final states, and the first measurement of transverse polarization in $t\\overline{t}$ production. The polarization along the beam axis is combined with the previous result in the dilepton final states by the D0 experiment. The observed distributions are consistent with the Standard Model of nearly no polarization and no indication for beyond Standard Model physics is observed. The measurement offers legacy result from unique Tevatron Collider data and provides more information about the top quark production and decays, about the properties of the heaviest elementary particle.

Activity of safety review for the facilities using nuclear material (2). Safety review results and maintenance experiences for hot laboratories

International Nuclear Information System (INIS)

Amagai, Tomio; Fujishima, Tadatsune; Mizukoshi, Yasutaka; Sakamoto, Naoki; Ohmori, Tsuyoshi

2009-01-01

In the site of O-arai Research and Development Center of Japan Atomic Energy Agency (JAEA), five hot laboratories for post-irradiation examination and development of plutonium fuels are operated more than 30 years. A safety review method for preventive maintenance on these hot laboratories includes test facilities and devices are established in 2003. After that, the safety review of these facilities and devices are done and taken the necessary maintenance based on the results in each year. In 2008, 372 test facilities and devices in these hot laboratories were checked and reviewed by this method. As a results of the safety review, repair issues of 38 facilities of above 372 facilities were resolved. This report shows the review results and maintenance experiences based on the results. (author)

Search for Higgs-boson production in association with a top-quark pair in the boosted regime with the CMS experiment

Energy Technology Data Exchange (ETDEWEB)

Williamson, Shawn Darell

2016-11-11

In 2012, the last missing piece of the Standard Model of particle physics has been discovered by the ATLAS and CMS collaborations, the Higgs boson. Still, some production modes of this particle remain undiscovered to date. One of them is the Higgs-boson production in association with a top-quark pair (t anti tH). A special feature of this process is the direct access to one of the most important Higgs-boson properties: the top-Higgs Yukawa coupling. The small cross section of t anti tH production is one of the reasons, why this process still remains unobserved. Especially for a Higgs boson decaying into a bottom-quark pair, the irreducible background by top-quark pair production is overwhelming. A further challenge is the ambiguous assignment of jets to the numerous final-state particles in the reconstruction of the collision event. A solution to this problem is provided by the investigation of a phase space, where the massive particles feature large transverse momenta, the boosted regime. For this special case, the decay products of the massive particles are collimated and the original massive particles can be reconstructed and identified with the help of dedicated algorithms. This thesis presents the implementation, optimization, and execution of the boosted analysis strategy in a search for t anti tH production with a Higgs-boson decay into a bottom-quark pair and a semileptonic top-quark pair decay. The search is performed based on proton-proton collisions at a center-of-mass energy of √(s)=13 TeV recorded with the CMS experiment in 2015. It represents the first search for t anti tH production with a Higgs-boson decay into a bottom-quark pair and a semileptonic top-quark pair decay at a center-of-mass energy of √(s)=13 TeV. Further, this search features the first dedicated investigation of the boosted regime in the search for t anti tH production.

Seed Transmission of Beet Curly Top Virus and Beet Curly Top Iran Virus in a Local Cultivar of Petunia in Iran

Science.gov (United States)

Anabestani, Ameneh; Behjatnia, Seyed Ali Akbar; Izadpanah, Keramat; Tabein, Saeid

2017-01-01

Beet curly top virus (BCTV) and beet curly top Iran virus (BCTIV) are known as the causal agents of curly top disease in beet and several other dicotyledonous plants in Iran. These viruses are transmitted by Circulifer species, and until now, there has been no confirmed report of their seed transmission. A percentage (38.2–78.0%) of the seedlings developed from the seeds of a petunia local cultivar under insect-free conditions showed stunting, interveinal chlorosis, leaf curling, and vein swelling symptoms, and were infected by BCTV when tested by PCR. Presence of BCTV in seed extracts of petunia local cultivar was confirmed by PCR and IC-PCR, followed by sequencing. Agroinoculation of curly top free petunia plants with a BCTV infectious clone resulted in BCTV infection of plants and their developed seeds. These results show the seed infection and transmission of BCTV in a local cultivar of petunia. Similar experiments performed with BCTIV showed that this virus is also seed transmissible in the same cultivar of petunia, although with a lower rate (8.8–18.5%). Seed transmission of curly top viruses may have significant implications in the epidemiology of these viruses. PMID:29035342

A philosophy for space nuclear systems safety

International Nuclear Information System (INIS)

Marshall, A.C.

1992-01-01

The unique requirements and contraints of space nuclear systems require careful consideration in the development of a safety policy. The Nuclear Safety Policy Working Group (NSPWG) for the Space Exploration Initiative has proposed a hierarchical approach with safety policy at the top of the hierarchy. This policy allows safety requirements to be tailored to specific applications while still providing reassurance to regulators and the general public that the necessary measures have been taken to assure safe application of space nuclear systems. The safety policy used by the NSPWG is recommended for all space nuclear programs and missions

Fusion integral experiments and analysis and the determination of design safety factors - I: Methodology

International Nuclear Information System (INIS)

Youssef, M.Z.; Kumar, A.; Abdou, M.A.; Oyama, Y.; Maekawa, H.

1995-01-01

The role of the neutronics experimentation and analysis in fusion neutronics research and development programs is discussed. A new methodology was developed to arrive at estimates to design safety factors based on the experimental and analytical results from design-oriented integral experiments. In this methodology, and for a particular nuclear response, R, a normalized density function (NDF) is constructed from the prediction uncertainties, and their associated standard deviations, as found in the various integral experiments where that response, R, is measured. Important statistical parameters are derived from the NDF, such as the global mean prediction uncertainty, and the possible spread around it. The method of deriving safety factors from many possible NDFs based on various calculational and measuring methods (among other variants) is also described. Associated with each safety factor is a confidence level, designers may choose to have, that the calculated response, R, will not exceed (or will not fall below) the actual measured value. An illustrative example is given on how to construct the NDFs. The methodology is applied in two areas, namely the line-integrated tritium production rate and bulk shielding integral experiments. Conditions under which these factors could be derived and the validity of the method are discussed. 72 refs., 17 figs., 4 tabs

The Belgian experience on the backfitting and safety upgrading of old operating nuclear power plants

International Nuclear Information System (INIS)

Brognon, T.

1993-01-01

The paper describes the methodology for backfitting and safety upgrading during the reevaluation of the Belgian NPP's: first generation (Doel-1, Doel-2, Tihange-1) and second generation plants (Doel-3, Doel-4, Tihange-2 and Tihange-3). A list of essential safety subjects and topics is given. The experience has proved the feasibility of a safety upgrading of operating NPP without injury to its availability, the benefit of a close cooperation between owner, engineering company and safety authorities throughout the project. A global approach to solving numerous specific deficiencies along with the optimization of the investments regarding the safety improvement of the NPP is suggested. Further increase of the know-how will be achieved through the present Belgian programme along with similar activities abroad. (R.I.)

Naisjuhtidega ettevõtete TOP 70

Index Scriptorium Estoniae

2003-01-01

Naisjuhtidega ettevõtete TOP 70. Käibe TOP 30. Käibe kasvu TOP 30. Kasumi TOP 30. Kasumi kasvu TOP 30. Rentaabluse TOP 30. Omakapitali tootlikkuse TOP 30. Nais- ja meesjuhtidega ettevõtted 2001. aasta 500 edukama ettevõtte hulgas. Naistegevjuhtidega firmade TOP 2001 ja 2002. Riigi- ja kohaliku omavalitsuse asutuste naisjuhtide TOP 20. Riigi- ja kohaliku omavalitsuse asutuste eelarve TOP 20. Riigi- ja kohaliku omavalitsuse asutuste töötajate arvu TOP 20. Naistegevjuhtidega firmade osakaal 2001. aastal. Riigi- ja kohaliku omavalitsuse asutuste naisjuhtide aastapalga TOP 20. Kommenteerib Tiina Raitviir.

Audiitorfirmade TOP 50 aastal 2000

Index Scriptorium Estoniae

2001-01-01

Audiitorfirmade käibe TOP 50, käibe kasvu TOP 25, käibe languse TOP 15, kasumi TOP 50, kasumi kasvu TOP 10, kasumi languse TOP 10, audiitorfirmade finantsnäitajad. Rentaabluse TOP 50, varade tootlikkuse TOP 50

EXPERIENCE NETWORKING UNIVERSITY OF EDUCATION TRAINING MASTERS SAFETY OF LIFE

OpenAIRE

Elvira Mikhailovna Rebko

2016-01-01

The article discloses experience networking of universities (Herzen State Pedagogical University and Sakhalin State University) in the development and implementation of joint training programs for master’s education in the field of life safety «Social security in the urban environment». The novelty of the work is to create a schematic design of basic educational training program for master’s education in the mode of networking, and to identify effective instructional techniques and conditions...

Measurement of the top quark properties at the Tevatron and the LHC

CERN Document Server

INSPIRE-00040958

2014-01-01

Almost two decades after its discovery at Fermilab's Tevatron collider experiments, the top quark is still under the spotlight due to its connections to some of the most interesting puzzles in the Standard Model. The Tevatron has been shut down two years ago, yet some interesting results are coming out of the CDF and D0 collaborations. The LHC collider at CERN produced two orders of magnitude more top quarks than Tevatron's, thus giving birth to a new era for top quark physics. While the LHC is also down at the time of this writing, many top quark physics results are being extracted out of the 7\\,TeV and 8\\,TeV proton proton collisions by the ATLAS and CMS collaborations, and many more are expected to appear before the LHC will be turned on again sometime in 2015. These proceedings cover a selection of recent results produced by the Tevatron and LHC experiments.

Measurement of single top quark production with CMS

CERN Document Server

Andrea, Jeremy

2018-01-01

Several measurements of single top quark production in proton-proton collisions at the LHC at centre-of-mass energies of 7, 8 and 13 TeV, using data collected with the CMS experiment, are presented. The analyses investigate separately the productions of top via t-channel exchange, in association with a W boson (tW) or via the s-channel. Final states with at least one charged lepton and one b-jet are explored to measure inclusive production cross sections. Fiducial and differential cross section measurements in the t-channel are also reported. The measurements can be used to constrain directly the Vtb CKM matrix element by comparing with the most precise standard model theory predictions. Measurements of rare processes involving a top quark and a neutral EWK boson (Z or photon) are also discussed.

New Physics with Energetic Top Quarks

CERN Document Server

Andeen, Timothy; The ATLAS collaboration

2018-01-01

Many theories beyond the Standard Model predict new phenomena which decay to energetic top quarks. Searches for such new physics models are performed using the ATLAS experiment at the LHC using proton-proton collision data collected in 2015 and 2016 with a center-of-mass energy of 13 TeV. Selected recent results will be discussed.

Top-down versus bottom-up processing of influence diagrams in probabilistic analysis

International Nuclear Information System (INIS)

Timmerman, R.D.; Burns, T.J.; Dodds, H.L. Jr.

1986-01-01

Recent work by Phillips and Selby has shown that influence diagram methodology can be a useful analytical tool in reactor safety studies. In some instances an influence diagram can be used as a graphical representation of probabilistic dependence within a system or event sequence. Under these circumstances, Bayesian statistics is employed to transform the relationships depicted in the influence diagram into the correct expression for a desired marginal probability (e.g. the top node). Top-down and bottom-up algorithms have emerged as the dominant methods for quantifying influence diagrams. The purpose of this paper is to demonstrate a potential error in employing the bottom-up algorithm when dealing with interdependencies

Constraining new resonant physics with top spin polarisation information

Energy Technology Data Exchange (ETDEWEB)

Englert, Christoph; Nordstroem, Karl [University of Glasgow, SUPA, School of Physics and Astronomy, Glasgow (United Kingdom); Ferrando, James [DESY Hamburg, Hamburg (Germany)

2017-06-15

We provide a comprehensive analysis of the power of including top quark-polarisation information to kinematically challenging top pair resonance searches, for which ATLAS and CMS start losing sensitivity. Following the general modelling and analysis strategies pursued by the experiments, we analyse the semi-leptonic and the di-lepton channels and show that including polarisation information can lead to large improvements in the limit setting procedures with large data sets. This will allow us to set stronger limits for parameter choices where sensitivity from the invariant mass of the top pair is not sufficient. This highlights the importance of spin observables as part of a more comprehensive set of observables to gain sensitivity to BSM resonance searches. (orig.)

Core-debris quenching-heat-transfer rates under top- and bottom-reflood conditions

International Nuclear Information System (INIS)

Ginsberg, T.; Tutu, N.; Klages, J.; Schwarz, C.E.; Sanborn, Y.

1983-02-01

This paper presents recent experimental data for the quench-heat-transfer characteristics of superheated packed beds of spheres which were cooled, in separate experiments, by top- and bottom-flooding modes. Experiments were carried out with beds of 3-mm steel spheres of 330-mm height. The initial bed temperature was 810 K. The observed heat-transfer rates are strongly dependent on the mode of water injection. The results suggest that top-flood bed quench heat transfer is limited by the rate at which water can penetrate the bed under two-phase countercurrent-flow conditions. With bottom-reflood the heat-transfer rate is an order-of-magnitude greater than under top-flood conditions and appears to be limited by particle-to-fluid film boiling heat transfer

Jaekaubanduse TOP 100 aastal 2001

Index Scriptorium Estoniae

2002-01-01

TOP 100. Käibe TOP 30. Käibe kasvu TOP 30. Kasumi TOP 30. Kasumi kasvu TOP 30. Rentaabluse TOP 30. Varade tootlikkuse TOP 30. Jaekaubandusettevõtete finantsseadmed. Jaekaubandusettevõtete üldandmed

Arvutifirmade TOP 101 aastal 2004

Index Scriptorium Estoniae

2005-01-01

Arvutifirmade TOP 101; Käibe TOP 20; Käibe kasvu TOP 15; Kasumi TOP 15; Rentaabluse TOP 20; Kasumi kasvu TOP 15; Omakapiali tootlikkuse TOP 15; Eesti arvutifirmade finantsandmed; Arvutifirmade üldandmed

Measurements of the top quark mass using the CMS and ATLAS detectors at the LHC

CERN Document Server

Menke, Sven; The ATLAS collaboration

2018-01-01

Measurements of the top quark mass obtained by the ATLAS and CMS experiments in proton-proton collisions at the LHC for centre-of-mass energies of 7, 8 and 13 TeV are presented. The mass of the top quark is measured using several methods and channels, including the reconstructed invariant mass distribution of the top quark and shapes of kinematic observables from top quark decay products. Measurements of the top-quark pole-mass based on the inclusive and differential top-anti-top production cross sections and observables based on the differential cross section in the top-pair plus 1 jet channel are also discussed.

What makes the hedonic experience of a meal in a top restaurant special and retrievable in the long term? Meal-related, social and personality factors.

Science.gov (United States)

Muñoz, Francisco; Hildebrandt, Andrea; Schacht, Annekathrin; Stürmer, Birgit; Bröcker, Felix; Martín-Loeches, Manuel; Sommer, Werner

2018-06-01

Knowing what makes a top gastronomy experience unique and retrievable in the long term is of interest for scientific and economic reasons. Recent attempts to isolate predictors of the hedonic evaluation of food have afforded several factors, such as individual and social attributes, or liking/disliking profiles. However, in these studies relevant variables have been examined in isolation without an integrative perspective. Here we investigated 80 guests enjoying a 23-course meal in a top gastronomy restaurant, in groups of four. Our main question concerned the factors driving the overall evaluation of the meal at its conclusion and after three months. To this aim we administered the Big Five Personality Inventory before the meal, dish-by-dish hedonic ratings, and a multi-dimensional Meal Experience Questionnaire (MEQ) at the end of the meal. Hedonic evaluations of the meal were collected immediately after the meal and three months later. Better immediate overall evaluations were predicted by both the number of peaks in dish-by-dish ratings and by positive ratings of the final dish. Both factors and the number of troughs were also critical for the long-term evaluation after three months. The MEQ dimensions overall interest, valence and distraction predicted immediate evaluations, while the long-term evaluations were determined by interest and high scores on the personality traits agreeableness and conscientiousness. High consistency of the hedonic ratings within quartets indicated the relevance of commensality for the meal experience. The present findings highlight the simultaneous relevance of food- and personality-related factors and commensality for a top gastronomy meal experience in the short and long-run. The uncovered relationships are of theoretical interest and for those involved in designing meals for consumers in various settings. Copyright © 2018 Elsevier Ltd. All rights reserved.

Majutusasutuste TOP 40 aastal 2002

Index Scriptorium Estoniae

2003-01-01

Majutusasutuste TOP 40 aastal 2002. Käibe TOP 40. Kasumi TOP 40. Käibe kasvu TOP 20. Kasumi kasvu TOP 20. Rentaabluse TOP 20. Omakapitali tootlikkuse TOP 20. Majutusasutuste üldandmed. Majutusasutuste finantsandmed

Põlvamaa ettevõtete TOP 50

Index Scriptorium Estoniae

2004-01-01

Ettevõtete TOP 50. Käibe TOP 40. Kasumi TOP 40. Käibe kasvu TOP 20. Kasumi kasvu TOP 20. Rentaabluse TOP 20. Omakapitali tootlikkuse TOP 20. Põlvamaa firmade üldandmed. Põlvamaa firmade finantsandmed

Top-level regulatory criteria for the standard MHTGR

Energy Technology Data Exchange (ETDEWEB)

NONE

1986-10-15

The Licensing Plan for the Standard MHTGR (Ref. 1) describes a program to support a U.S. Nuclear Regulatory Commission (NRC) design review and approval. The Plan calls for the submittal of Top-Level Regulatory Criteria to the NRC for concurrence with their completeness and acceptability for the MHTGR program. The Top-Level Regulatory Criteria are defined as the standards for judging licensability that directly specify acceptable limits for protection of the public health and safety and the environment. The criteria proposed herein are for normal plant operation and a broad spectrum of anticipated events, including accidents. The approach taken is to define a set of criteria which are general as opposed to being design specific. Specifically, it is recommended that criteria be met which: 1. Are less prescriptive than current regulation, thereby encouraging maximum flexibility in design approaches. 2. Are measurable. 3. Are not more strict than the criteria for current power plants.

Eesti Ettevõtete TOP 100

Index Scriptorium Estoniae

2002-01-01

TOP 100. Käibe TOP 500. Käibe kasvu TOP 100. Kasumi TOP 100. Kasumi kasvu TOP 100. Rentaabluse TOP 100. Omakapitali tootlikkuse TOP 100. Eesti edukamate ettevõtete üldandmed. Eesti edukamate ettevõtete finantsnäitajad. Valdkonna ja maakonna TOP-ide edukamate ettevõtete finantsnäitajad

Safety analysis report for the Hanford Critical Mass Laboratory: Supplement No. 2. Experiments with heterogeneous assemblies

International Nuclear Information System (INIS)

Gore, B.F.; Davenport, L.C.

1981-04-01

Factors affecting the safety of criticality experiments using heterogeneous assemblies are described and assessed. It is concluded that there is no substantial change in safety from experiments already being routinely performed at the Critical Mass Laboratory (CML), and that laboratory and personnel safety are adequately provided by the combination of engineered and administrative safety limits enforced at the CML. This conclusion is based on the analysis of operational controls, potential hazards, and the consequences of accidents. Contingencies considered that could affect nuclear criticality include manual changes in fuel loadings, water flooding, fire, explosion, loss of services, earthquake, windstorm, and flood. Other potential hazards considered include radiation exposure to personnel, and potential releases within the Assembly Room and outside to the environment. It is concluded that the Maximum Credible Nuclear Burst of 3 x 10 18 fissions (which served as the design basis for the CML) is valid for heterogeneous assemblies as well as homogeneous assemblies. This is based upon examination of the results of reactor destructive tests and the results of the SL-1 reactor destructive accident. The production of blast effects which might jeopardize the CML critical assembly room (of thick reinforced concrete) is not considered credible due to the extreme circumstances required to produce blast effects in reactor destructive tests. Consequently, it is concluded that, for experiments with heterogeneous assemblies, the consequences of the Maximum Credible Burst are unchanged from those previously estimated for experiments with homogeneous systems

Viljandimaa ettevõtete TOP 50

Index Scriptorium Estoniae

2005-01-01

Viljandimaa ettevõtete TOP 50; Käibe TOP 35; Kasumi TOP 35; Käibe kasvu TOP 20; Kasumi kasvu TOP 20; Rentaabluse TOP 20; Omakapitali tootlikkuse TOP 20; Viljandimaa ettevõtete üld- ja finantsandmed

Jõgevamaa ettevõtete TOP 50

Index Scriptorium Estoniae

2005-01-01

Jõgevamaa ettevõtete TOP 50; Käibe TOP 35; Kasumi TOP 35; Käibe kasvu TOP 20; Kasumi kasvu TOP 20; Rentaabluse TOP 20; Omakapitali tootlikkuse TOP 20; Jõgevamaa ettevõtete üld- ja finantsandmed

Jõgevamaa ettevõtete TOP 55

Index Scriptorium Estoniae

2004-01-01

Jõgevamaa ettevõtete TOP 55 aastal 2003. Käibe TOP 40. Kasumi TOP 40. Käibe kasvu TOP 20. Kasumi kasvu TOP 20. Rentaabluse TOP 20. Omakapitali tootlikkuse TOP 20. Jõgevamaa firmade üld- ja finantsandmed

Turismifirmade 2000. a. TOP 30

Index Scriptorium Estoniae

2001-01-01

Turismiettevõtete üldandmed: turismiettevõtete finantsnäitajad; käibe TOP 30; käibe kasvu TOP 10; kasumi TOP 20; kasumi kasvu TOP 10; kasumi languse TOP; rentaabluse TOP 10; varade tootlikkuse TOP 10

Playing it safe: Patron safety strategies and experience of violence in night-time entertainment districts.

Science.gov (United States)

Zhou, Jin; Droste, Nicolas; Curtis, Ashlee; Zinkiewicz, Lucy; Miller, Peter

2018-03-01

Incidences of violence are elevated in night-time entertainment districts. Research suggests that safety-related behavioural strategies adopted while drinking can reduce negative alcohol-related outcomes. The current study investigates the use of safety strategies and its association with experiences of violence among patrons from the general population. Patron interviews (N = 3949) were conducted in and around licenced venues in Newcastle (New South Wales) and Geelong (Victoria) during peak trading hours (Friday and Saturday, 21:00-01:00 h). Participants (mean age = 24.3, SD = 5.8; male 54.4%) were asked to report what measures, if any, they used to keep safe when drinking and whether they had been involved in a violent incident in the last 12 months. After controlling for patron demographics and location, the use of multiple (more than one) safety strategies was significantly associated with reduced odds of involvement in a violent incident (odds ratio = 0.64, 95% confidence interval 0.49-0.85, P = 0.002). Significant gender differences were observed in the number and type of safety strategies reported. Increasing the number of safety-related behaviours during drinking occasions is associated with a small but significant reduction in experiencing alcohol-related harms, such as violence. [Zhou J, Droste N, Curtis A, Zinkiewicz L, Miller P. Playing it safe: Patron safety strategies and experience of violence in night-time entertainment districts. © 2017 Australasian Professional Society on Alcohol and other Drugs.

Online-kaubanduse TOP aastal 2003

Index Scriptorium Estoniae

2004-01-01

Online-kaubanduse TOP aastal 2003. Käibe TOP 5. Käibe kasvu TOP 5. Rentaabluse TOP 5. Kasumi TOP 5. Kasumi kasvu TOP 5. Omakapitali tootlikkuse TOP 5. Lisa: TOPi koostamise metoodika. Online-kaubanduse firmade üldandmed. Online kaubanduse firmade finantsandmed

Ehitusmaterjalitootjate TOP 70 aastal 2003

Index Scriptorium Estoniae

2004-01-01

Ilmunud ka: Delovõje Vedomosti : Stroitelstvo, 29. sept. 2004, lk. 2,4. Ehitusmaterjalitootjate TOP 70; Käibe TOP 10; Käibe kasvu TOP 10; Kasumi TOP 10; Kasumi kasvu TOP 10; Rentaabluse TOP 10; Omakapitali tootlikkuse TOP. Ehitusmaterjalitootjate üldandmed

Measurement of top-quark mass and inclusive top-quark-pair production cross section in pp collisions at √(s)=7/8 TeV with CMS

International Nuclear Information System (INIS)

Schlieckau, Eike Steffen

2014-09-01

One of the most intriguing particles in the Standard Model is the top quark, the heaviest fundamental particle known to date. In this thesis, the mass of the top quark and the production cross section for top-quark pairs are measured from events with a top-quark pair decaying only into hadrons. This challenging decay mode features a high rate but is drowned by multijet background events. The top quarks are produced at the Large Hadron Collider and the decay products are detected with the Compact Muon Solenoid experiment. Data collected at centre-of-mass energies of 7 and 8 TeV with integrated luminosities of 3.54 fb -1 and 18.2 fb -1 is used for the presented measurements. In order to improve the reconstruction and identification of the desired events, constrained least-squares fitting is utilised, which exploits the kinematics of top-quark pair events. The top-quark mass and the production cross section for top-quark pairs are extracted using likelihoods from events with at least six jets created from the hadrons in the final state. In order to reduce systematic uncertainties on the result, their main sources are incorporated into the likelihoods and are estimated in parallel with the mass itself. Combining all these methods, the most precise measurement of the top-quark mass from all-jets events so far is achieved. The top-quark mass is measured to be 172.08±0.90 GeV.

Desk-top publishing using IBM-compatible computers.

Science.gov (United States)

Grencis, P W

1991-01-01

This paper sets out to describe one Medical Illustration Departments' experience of the introduction of computers for desk-top publishing. In this particular case, after careful consideration of all the options open, an IBM-compatible system was installed rather than the often popular choice of an Apple Macintosh.

Experience and lessons learned in the assessment of safety justifications for experiments mounted in research reactors

International Nuclear Information System (INIS)

Cox, R.F.

1990-01-01

Some experiments in research reactors are arguably a risky undertaking due to their uncertain outcome. The justifications for such experiments require careful assessment to validate their undertaking. The public, the operators and the installation itself must be safeguarded. Assessment of the potential risk is an acquired skill but in doing so the route can be eased by learning from the lessons experience can teach. This paper, essentially for the usage of safety managers, sets out some of the issues relating to the assessment process gained from our experience over a few tens of years in the assessment of experiments. Many of the conclusions reached may appear all too obvious viewed in retrospect, but they were not necessarily clear at the time. Those organizations setting up assessment teams may find some of the conclusions of value such that their proposed management system can embrace methodologies for assessment that can avoid or lessen the impact of some of the pitfalls we have tried to identify. Failure to recognise some of these points may run the risk of delayed clearances, dilated timescales and cost overruns. It is in the hope of reducing all these penalties that we offer our experiences

The Dark Side of Top Level Sport: An Autobiographic Study of Depressive Experiences in Elite Sport Performers.

Science.gov (United States)

Newman, Hannah J H; Howells, Karen L; Fletcher, David

2016-01-01

The general and sport psychology research converge to point to a complex relationship between depressive experiences and human performance. The purpose of this study was to explore the depressive experiences of top level athletes and the relationship of such experiences with sport performance. Twelve autobiographies of elite athletes representing eight sports were analyzed. The autobiographical analysis was informed by narrative tradition, using three types of narrative analysis: categorical content, categorical form, and holistic content. The analysis revealed a temporal aspect to the depressive experiences that the athletes reported. Initially, sport represented a form of escape from the depressive symptoms which had been exacerbated by both external stressors (e.g., experiencing bereavement) and internal stressors (e.g., low self-esteem). However, in time, the athletes typically reached a stage when the demands of their sport shifted from being facilitative to being debilitative in nature with an intensification of their depressive symptoms. This was accompanied by deliberations about continuing their engagement in sport and an acceptance that they could no longer escape from their symptoms, with or without sport. The findings extend the extant literature by suggesting a reciprocal relationship between depressive experiences and sport performance, and they support the general psychology literature relating to the negative impact of depression on performance. The applied implications of these findings are discussed emphasizing the importance of early identification of depressive symptoms and the adoption of a proactive approach in the prevention and management of symptoms.

Measurement of the Top Quark Mass at D0

Energy Technology Data Exchange (ETDEWEB)

Snyder, Scott Stuart [SUNY, Stony Brook

1995-05-01

The D0 experiment has recently reported the discovery of the standard model top quark in proton-antiproton collisions with a center of mass energy of 1:8TeV, based on an integrated lumi- nosity of approximately 50 $pb{-1}$ accumulated during the period 1992-1995. This work describes a measurement of the mass of the top using the lepton + jets channels of this data. The result is $mt = 199^{+19}_{-21}(stat.)^{+14}_ {-21}(syst.)GeV/c^2$.

Recent CMS measurements of the top quark mass

CERN Multimedia

CERN. Geneva

2014-01-01

The top quark is the heaviest known particle, and the only colored one that decays before hadronization. Its mass is a fundamental parameter of the standard model. Precision measurements of the top-quark mass can be used to test the self-consistency of the standard model and, at the same time, to study effects of non-perturbative QCD. CMS recently completed the set of standard top quark mass measurements at 8 TeV in all three decay channels, reaching sub-GeV uncertainty for the first time in a single analysis and combining to the most precise single-experiment measurement. With the steady increase in experimental precision comes a theoretical challenge of interpreting the results and the motivation of using alternative methods. In this talk we present the CMS set of analyses using the 8 TeV dataset, both with conventional methods and non-standard techniques targeting different definitions of the top quark mass. Furthermore we give an outlook at expected future improvements in both standard and alternative app...

Potential impact on food safety and food security from persistent organic pollutants in top soil improvers on Mediterranean pasture.

Science.gov (United States)

Brambilla, G; Abate, V; Battacone, G; De Filippis, S P; Esposito, M; Esposito, V; Miniero, R

2016-02-01

The organic carbon of biosolids from civil wastewater treatment plants binds persistent organic pollutants (POPs), such as polychlorodibenzo -dioxins and -furans (PCDD/Fs), dioxin and non-dioxin -like polychlorobiphenyls (DL and NDL-PCBs), polybrominated diphenyl ethers (PBDEs), and perfluorooctane sulfonic acid (PFOS). The use of such biosolids, derived digestates and composts as top soil improvers (TSIs) may transfer POPs into the food chain. We evaluated the potential carry-over of main bioavailable congeners from amended soil-to-milk of extensive farmed sheep. Such estimates were compared with regulatory limits (food security) and human intakes (food safety). The prediction model was based on farming practices, flocks soil intake, POPs toxicokinetics, and dairy products intake in children, of the Mediterranean area. TSI contamination ranged between 0.20-113 ng WHO-TEQ/kg dry matter for PCDD/Fs and DL-PCBs (N = 56), 3.40-616 μg/kg for ∑6 NDL-PCBs (N = 38), 0.06-17.2 and 0.12-22.3 μg/kg for BDE no. 47 and no. 99, 0.872-89.50 μg/kg for PFOS (N = 27). For a 360 g/head/day soil intake of a sheep with an average milk yield of 2.0 kg at 6.5% of fat percentage, estimated soil quality standards supporting milk safety and security were 0.75 and 4.0 ng WHO-TEQ/kg for PCDD/Fs and DL-PCBs, and 3.75 and 29.2 μg/kg for ∑6 NDL-PCBs, respectively. The possibility to use low-contaminated TSIs to maximize agriculture benefits and if the case, to progressively mitigate highly contaminated soils is discussed.

Hiiumaa ettevõtete TOP 50

Index Scriptorium Estoniae

2005-01-01

Hiiumaa ettevõtete TOP 50; Käibe TOP 35; Kasumi TOP 35; Hiiumaa ettevõtete üld- ja finantsandmed; Käibe kasvu TOP 20; Kasumi kasvu TOP 20; Rentaabluse TOP 20; Omakapitali tootlikkuse TOP 20. Vt samas: Teeli Remmalg: Hiiumaal jätkub plastitööstuse võidumarss

Large Scale Experiments on Spacecraft Fire Safety

DEFF Research Database (Denmark)

Urban, David L.; Ruff, Gary A.; Minster, Olivier

2012-01-01

-based microgravity facilities or has been limited to very small fuel samples. Still, the work conducted to date has shown that fire behaviour in low-gravity is very different from that in normal-gravity, with differences observed for flammability limits, ignition delay, flame spread behaviour, flame colour and flame......Full scale fire testing complemented by computer modelling has provided significant knowhow about the risk, prevention and suppression of fire in terrestrial systems (cars, ships, planes, buildings, mines, and tunnels). In comparison, no such testing has been carried out for manned spacecraft due...... to the complexity, cost and risk associ-ated with operating a long duration fire safety experiment of a relevant size in microgravity. Therefore, there is currently a gap in knowledge of fire behaviour in spacecraft. The entire body of low-gravity fire research has either been conducted in short duration ground...

Measurement of top quark polarization in top-antitop lepton+jets final states at D0

Energy Technology Data Exchange (ETDEWEB)

Augsten, Kamil [Czech Technical Univ., Prague (Czech Republic)

2016-01-01

This thesis presents a measurement of the top quark polarization in the $t\\overline{t}$ events produced in $p\\overline{p}$ collisions at $\\sqrt{s}=1.96$ TeV using data corresponding to 9.7 fb$^{-1}$ of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The final states used in the measurement contain one lepton and at least three jets. The polarization is measured using the angular distribution of leptons along three different axes: the beam axis, the helicity axis, and the transverse axis normal to the $t\\overline{t}$ production plane. This is the first measurement of top quark polarization at the Tevatron Collider in lepton+jets final states, and the first measurement of transverse polarization in $t\\overline{t}$ production. The polarization along the beam axis is combined with the previous result in the dilepton final states by the D0 experiment. The observed distributions are consistent with the Standard Model of nearly no polarization and no indication for beyond Standard Model physics is observed. The measurement offers legacy result from unique Tevatron Collider data and provides more information about the top quark production and decays, about the properties of the heaviest elementary particle.

Depression-Biased Reverse Plasticity Rule Is Required for Stable Learning at Top-Down Connections

Science.gov (United States)

Burbank, Kendra S.; Kreiman, Gabriel

2012-01-01

Top-down synapses are ubiquitous throughout neocortex and play a central role in cognition, yet little is known about their development and specificity. During sensory experience, lower neocortical areas are activated before higher ones, causing top-down synapses to experience a preponderance of post-synaptic activity preceding pre-synaptic activity. This timing pattern is the opposite of that experienced by bottom-up synapses, which suggests that different versions of spike-timing dependent synaptic plasticity (STDP) rules may be required at top-down synapses. We consider a two-layer neural network model and investigate which STDP rules can lead to a distribution of top-down synaptic weights that is stable, diverse and avoids strong loops. We introduce a temporally reversed rule (rSTDP) where top-down synapses are potentiated if post-synaptic activity precedes pre-synaptic activity. Combining analytical work and integrate-and-fire simulations, we show that only depression-biased rSTDP (and not classical STDP) produces stable and diverse top-down weights. The conclusions did not change upon addition of homeostatic mechanisms, multiplicative STDP rules or weak external input to the top neurons. Our prediction for rSTDP at top-down synapses, which are distally located, is supported by recent neurophysiological evidence showing the existence of temporally reversed STDP in synapses that are distal to the post-synaptic cell body. PMID:22396630

Depression-biased reverse plasticity rule is required for stable learning at top-down connections.

Directory of Open Access Journals (Sweden)

Kendra S Burbank

Full Text Available Top-down synapses are ubiquitous throughout neocortex and play a central role in cognition, yet little is known about their development and specificity. During sensory experience, lower neocortical areas are activated before higher ones, causing top-down synapses to experience a preponderance of post-synaptic activity preceding pre-synaptic activity. This timing pattern is the opposite of that experienced by bottom-up synapses, which suggests that different versions of spike-timing dependent synaptic plasticity (STDP rules may be required at top-down synapses. We consider a two-layer neural network model and investigate which STDP rules can lead to a distribution of top-down synaptic weights that is stable, diverse and avoids strong loops. We introduce a temporally reversed rule (rSTDP where top-down synapses are potentiated if post-synaptic activity precedes pre-synaptic activity. Combining analytical work and integrate-and-fire simulations, we show that only depression-biased rSTDP (and not classical STDP produces stable and diverse top-down weights. The conclusions did not change upon addition of homeostatic mechanisms, multiplicative STDP rules or weak external input to the top neurons. Our prediction for rSTDP at top-down synapses, which are distally located, is supported by recent neurophysiological evidence showing the existence of temporally reversed STDP in synapses that are distal to the post-synaptic cell body.

Measurement of the top quark mass in topologies enhanced with single top quarks produced in the $t$-channel at $\\sqrt{s}=8\\,\\mathrm{TeV}$ using the ATLAS experiment

CERN Document Server

INSPIRE-00288596

2014-01-01

A measurement of the top quark mass in topologies enhanced with single top quarks produced in the $t$-channel produced via weak interactions is presented. The dataset was collected at a centre-of-mass energy of $\\sqrt{s}=8\\,\\mathrm{TeV}$ with the ATLAS detector at the LHC and corresponds to an integrated luminosity of $20.3\\,\\mathrm{fb^{-1}}$. To determine the top quark mass a template method is used based on the distribution of the invariant mass of the lepton and the $b$-tagged jet as estimator. The result of the measurement is $m_{\\mathrm{top}} = 172.2 \\pm 0.7 {\\mathrm{(stat.)}} \\pm 2.0 {\\mathrm{(syst.)}}\\,\\mathrm{GeV}$.