Six-month outcome after transcatheter edge-to-edge repair of severe tricuspid regurgitation in patients with heart failure.

Science.gov (United States)

Orban, Mathias; Besler, Christian; Braun, Daniel; Nabauer, Michael; Zimmer, Marion; Orban, Martin; Noack, Thilo; Mehilli, Julinda; Hagl, Christian; Seeburger, Joerg; Borger, Michael; Linke, Axel; Thiele, Holger; Massberg, Steffen; Ender, Joerg; Lurz, Philipp; Hausleiter, Jörg

2018-06-01

Severe tricuspid regurgitation (TR) is common in patients with right-sided heart failure (HF) and causes substantial morbidity and mortality. Treatment options beyond medical therapy are limited for high-risk patients. Transcatheter edge-to-edge tricuspid valve (TV) repair showed procedural safety and short-term efficacy. Impact on mid-term outcome is unclear. This dual-centre observational study evaluates the mid-term safety, efficacy and clinical outcome after edge-to-edge TV repair for severe TR in patients with HF. Overall, 50 patients with right-sided HF and severe TR were treated with the transcatheter edge-to-edge repair technique; 14 patients were treated for isolated TR and 36 patients for combined mitral regurgitation (MR) and TR. At 6-month follow-up (available for 98% of patients), a persistent reduction of at least one echocardiographic TR grade was achieved in 90% of patients and New York Heart Association class improved in 79% of patients. The 6-minute walk distance increased by 44% (+84 m, P edge-to-edge TV repair for severe TR is safe and effective in reducing TR. It appears to be associated with improved clinical outcome in the majority of patients. © 2018 The Authors. European Journal of Heart Failure © 2018 European Society of Cardiology.

A hierarchical factor analysis of a safety culture survey.

Science.gov (United States)

Frazier, Christopher B; Ludwig, Timothy D; Whitaker, Brian; Roberts, D Steve

2013-06-01

Recent reviews of safety culture measures have revealed a host of potential factors that could make up a safety culture (Flin, Mearns, O'Connor, & Bryden, 2000; Guldenmund, 2000). However, there is still little consensus regarding what the core factors of safety culture are. The purpose of the current research was to determine the core factors, as well as the structure of those factors that make up a safety culture, and establish which factors add meaningful value by factor analyzing a widely used safety culture survey. A 92-item survey was constructed by subject matter experts and was administered to 25,574 workers across five multi-national organizations in five different industries. Exploratory and hierarchical confirmatory factor analyses were conducted revealing four second-order factors of a Safety Culture consisting of Management Concern, Personal Responsibility for Safety, Peer Support for Safety, and Safety Management Systems. Additionally, a total of 12 first-order factors were found: three on Management Concern, three on Personal Responsibility, two on Peer Support, and four on Safety Management Systems. The resulting safety culture model addresses gaps in the literature by indentifying the core constructs which make up a safety culture. This clarification of the major factors emerging in the measurement of safety cultures should impact the industry through a more accurate description, measurement, and tracking of safety cultures to reduce loss due to injury. Copyright © 2013 National Safety Council and Elsevier Ltd. All rights reserved.

FED-A, an advanced performance FED based on low safety factor and current drive

International Nuclear Information System (INIS)

Peng, Y.K.M.; Rutherford, P.H.

1983-08-01

The FED-A study aims to quantify the potential improvement in cost-effectiveness of the Fusion Engineering Device (FED) by assuming low safety factor q (less than 2 as opposed to about 3) at the plasma edge and noninductive current drive (as opposed to only inductive current drive). The FED-A performance objectives are set to be : (1) ignition assuming International Tokamak Reactor (INTOR) plamsa confinement scaling, but still achieving a fusion power amplification Q greater than or equal to 5 when the confinement is degraded by a factor of 2; (2) neutron wall loading of about 1 MW/m 2 , with 0.5 MW/m 2 as a conservative lower bound; and (3) more clearly power-reactor-like operations, such as steady state

General-Purpose Heat Source Safety Verification Test program: Edge-on flyer plate tests

International Nuclear Information System (INIS)

George, T.G.

1987-03-01

The radioisotope thermoelectric generator (RTG) that will supply power for the Galileo and Ulysses space missions contains 18 General-Purpose Heat Source (GPHS) modules. The GPHS modules provide power by transmitting the heat of 238 Pu α-decay to an array of thermoelectric elements. Each module contains four 238 PuO 2 -fueled clads and generates 250 W(t). Because the possibility of a launch vehicle explosion always exists, and because such an explosion could generate a field of high-energy fragments, the fueled clads within each GPHS module must survive fragment impact. The edge-on flyer plate tests were included in the Safety Verification Test series to provide information on the module/clad response to the impact of high-energy plate fragments. The test results indicate that the edge-on impact of a 3.2-mm-thick, aluminum-alloy (2219-T87) plate traveling at 915 m/s causes the complete release of fuel from capsules contained within a bare GPHS module, and that the threshold velocity sufficient to cause the breach of a bare, simulant-fueled clad impacted by a 3.5-mm-thick, aluminum-alloy (5052-T0) plate is approximately 140 m/s

Organizational factors in nuclear safety

International Nuclear Information System (INIS)

Wilpert, Bernhard

2000-01-01

The overall picture of factors which contributed to the event presents a panorama of a NPP where organizational and managerial characteristics were intricately intertwined and emerged as crucial for a general deterioration of the plant's capabilities to continually correct its deficiencies and optimize its operations. In the following author shall attempt to first cover various important efforts to modeling organizational factors relevant to safety. The second part of my presentation will offer an attempt towards an integrative model. The third part concludes with an agenda for research and practice. Most of the twelve different approaches above attempt to consider safety relevant organizational factors by way of pragmatic classifications. Together with their sub-categories we can count close to 160 different factors on various levels of abstraction. This is tantamount to say that most approaches lack systematic theoretical underpinnings. Thus then arises the question whether we need to develop a generic model, which promises to encompass these three major approaches altogether. Practical issues emerge particularly in the domain of organizational development, i.e. the goal oriented efforts to change the structures and the functioning of nuclear operations in such a way that the desired outputs in terms safety and reliability result in a sustained fashion. Again, these practical concerns are intimately related to developments and advances in theory and methodology. Only a close cooperation among scientists from various disciplines and of practitioners holds the promise of adequately understanding and use of organizational factors in future improving the safety record of nuclear industry worldwide. (S.Y.)

Human factors in nuclear safety oversight

International Nuclear Information System (INIS)

Taylor, K.

1989-01-01

The mission of the nuclear safety oversight function at the Savannah River Plant is to enhance the process and nuclear safety of site facilities. One of the major goals surrounding this mission is the reduction of human error. It is for this reason that several human factors engineers are assigned to the Operations assessment Group of the Facility Safety Evaluation Section (FSES). The initial task of the human factors contingent was the design and implementation of a site wide root cause analysis program. The intent of this system is to determine the most prevalent sources of human error in facility operations and to assist in determining where the limited human factors resources should be focused. In this paper the strategy used to educate the organization about the field of human factors is described. Creating an awareness of the importance of human factors engineering in all facets of design, operation, and maintenance is considered to be an important step in reducing the rate of human error

Stress intensity factors of three parallel edge cracks under bending moments

International Nuclear Information System (INIS)

Ismail, A E

2013-01-01

This paper reports the study of stress intensity factors (SIF) of three edge cracks in a finite plate under bending moments. The goal of this paper was to analyze the three edge crack interactions under such loading. Several studies can be found in literature discussing on mode I SIF. However, most of these studies obtained the SIFs using tensile force. Lack of SIF reported discussing on the SIFs obtained under bending moments. ANSYS finite element program was used to develop the finite element model where singular elements were used to model the cracks. Different crack geometries and parameters were utilized in order to characterize the SIFs. According to the present results, crack geometries played a significant role in determining the SIFs and consequently induced the crack interaction mechanisms

Organizational factors influencing improvements in safety

International Nuclear Information System (INIS)

Marcus, A.; Nichols, M.L.; Olson, J.; Osborn, R.; Thurber, J.

1992-01-01

Research reported here seeks to identify the key organizational factors that influence safety-related performance indicators in nuclear power plants over time. It builds upon organizational factors identified in NUREG/CR-5437, and begins to develop a theory of safety-related performance and performance improvement based on economic and behavioral theories of the firm. Central to the theory are concepts of past performance, problem recognition, resource availability, resource allocation, and business strategies that focus attention. Variables which reflect those concepts are combined in statistical models and tested for their ability to explain scrams, safety system actuations, significant events, safety system failures, radiation exposure, and critical hours. Results show the performance indicators differ with respect to the sets of variables which serve as the best predictors of future performance, and past performance is the most consistent predictor of future performance

Importance of human factors on nuclear installations safety

International Nuclear Information System (INIS)

Caruso, G.J.

1990-01-01

Actually, installations safety and, in particular the nuclear installations infer a strong incidence in human factors related to the design and operation of such installations. In general, the experience aims to that the most important accidents have happened as result of the components' failures combination and human failures in the operation of safety systems. Human factors in the nuclear installations may be divided into two areas: economy and human reliability. Human factors treatments for the safety evaluation of the nuclear installations allow to diagnose the weak points of man-machine interaction. (Author) [es

The role of psychological factors in workplace safety.

Science.gov (United States)

Kotzé, Martina; Steyn, Leon

2013-01-01

Workplace safety researchers and practitioners generally agree that it is necessary to understand the psychological factors that influence people's workplace safety behaviour. Yet, the search for reliable individual differences regarding psychological factors associated with workplace safety has lead to sparse results and inconclusive findings. The aim of this study was to investigate whether there are differences between the psychological factors, cognitive ability, personality and work-wellness of employees involved in workplace incidents and accidents and/or driver vehicle accidents and those who are not. The study population (N = 279) consisted of employees employed at an electricity supply organisation in South Africa. Mann-Whitney U-test and one-way ANOVA were conducted to determine the differences in the respective psychological factors between the groups. These results showed that cognitive ability did not seem to play a role in workplace incident/accident involvement, including driver vehicle accidents, while the wellness factors burnout and sense of coherence, as well as certain personality traits, namely conscientiousness, pragmatic and gregariousness play a statistically significant role in individuals' involvement in workplace incidents/accidents/driver vehicle accidents. Safety practitioners, managers and human resource specialists should take cognisance of the role of specifically work-wellness in workplace safety behaviour, as management can influence these negative states that are often caused by continuously stressful situations, and subsequently enhance work place safety.

Human factors in safety and business management.

Science.gov (United States)

Vogt, Joachim; Leonhardt, Jorg; Koper, Birgit; Pennig, Stefan

2010-02-01

Human factors in safety is concerned with all those factors that influence people and their behaviour in safety-critical situations. In aviation these are, for example, environmental factors in the cockpit, organisational factors such as shift work, human characteristics such as ability and motivation of staff. Careful consideration of human factors is necessary to improve health and safety at work by optimising the interaction of humans with their technical and social (team, supervisor) work environment. This provides considerable benefits for business by increasing efficiency and by preventing incidents/accidents. The aim of this paper is to suggest management tools for this purpose. Management tools such as balanced scorecards (BSC) are widespread instruments and also well known in aviation organisations. Only a few aviation organisations utilise management tools for human factors although they are the most important conditions in the safety management systems of aviation organisations. One reason for this is that human factors are difficult to measure and therefore also difficult to manage. Studies in other domains, such as workplace health promotion, indicate that BSC-based tools are useful for human factor management. Their mission is to develop a set of indicators that are sensitive to organisational performance and help identify driving forces as well as bottlenecks. Another tool presented in this paper is the Human Resources Performance Model (HPM). HPM facilitates the integrative assessment of human factors programmes on the basis of a systematic performance analysis of the whole system. Cause-effect relationships between system elements are defined in process models in a first step and validated empirically in a second step. Thus, a specific representation of the performance processes is developed, which ranges from individual behaviour to system performance. HPM is more analytic than BSC-based tools because HPM also asks why a certain factor is

Interpolation of Gamma-ray buildup Factors for Arbitrary Source Energies in the Vicinity of the K-edge

International Nuclear Information System (INIS)

Michieli, I.

1998-01-01

Recently, a new buildup factors approximation formula based on the expanded polynomial set (E-P function) was successfully introduced (Michieli 1994.) with the maximum approximation error below 4% throughout the standard data domain. Buildup factors interpolation in E-P function parameters for arbitrary source energies, near the K-edge in lead, was satisfactory. Maximum interpolation error, for lead, lays within 12% what appears to be acceptable for most Point Kernel application. 1991. Harima at. al., showed that, near the K-edge, fluctuation in energy of exposure rate attenuation factors i.e.: D(E)B(E, μ E r)exp(-μ E r), given as a function of penetration depth (r) in ordinary length units (not mfps.), is not nearly as great as that of buildup factors. That phenomenon leads to the recommendation (ANSI/ANS-6.4.3) that interpolations in that energy range should be made in the attenuation factors B(E, μ E r)exp(-μ E r) rather than in the buildup factors alone. In present article, such interpolation approach is investigated by applying it to the attenuation factors in lead, with E-P function representation of exposure buildup factors. Simple form of the E-P function leads to strait calculation of new function parameters for arbitrary source energy near the K-edge and thus allowing the same representation form of buildup factors as in the standard interpolation procedure. results of the interpolation are discussed and compared with those from standard approach. (author)

Organizational factors affecting safety implementation in food companies in Thailand.

Science.gov (United States)

Chinda, Thanwadee

2014-01-01

Thai food industry employs a massive number of skilled and unskilled workers. This may result in an industry with high incidences and accident rates. To improve safety and reduce the accident figures, this paper investigates factors influencing safety implementation in small, medium, and large food companies in Thailand. Five factors, i.e., management commitment, stakeholders' role, safety information and communication, supportive environment, and risk, are found important in helping to improve safety implementation. The statistical analyses also reveal that small, medium, and large food companies hold similar opinions on the risk factor, but bear different perceptions on the other 4 factors. It is also found that to improve safety implementation, the perceptions of safety goals, communication, feedback, safety resources, and supervision should be aligned in small, medium, and large companies.

Determination of engineering safety factor -routine in Hungary (a methodology for the normal operation local power engineering safety factors)

International Nuclear Information System (INIS)

Szecsenyi, Z.; Korpas, L.; Bona, G.; Kereszturi, A.

2010-01-01

From the late nineties Paks Nuclear Power Plant-in collaboration with KFKI Atomic Energy Research Institute (KFKI AEKI)- is developing a system for determining the normal operation local power engineering safety factors. The system is based on a Monte Carlo sampling of the uncertain model input parameters. Additionally, the comparison of the calculation to the in-core measurements plays essential role for determining some important input parameters. By using new fuel types and the corresponding more recent detailed technological data, the applied method is being improved from time to time. Presently, the actually used and authorized engineering safety factors at Paks NPP are determined by using this method. In the paper, the system.s main properties are described (not going beyond the possible extent). The main points are as follows:-Mathematical definition of the engineering safety factor;-Sources of the uncertainties;-Input error propagation method constituting the basis of the system;-Flow-chart of the subsequent steps of the determination Finally, in the paper the engineering safety factors values of some selected parameters are presented as examples for demonstration of the capability of the method. (Authors)

Thumbnail Image with Blurry Edge Information Utilizing Half Factor Rules

Directory of Open Access Journals (Sweden)

Boon Tatt Koik

2014-01-01

Full Text Available Thumbnail image with blurry edge information has attracted much attention in recent years. Thumbnail image, which is a tiny version of the original image, enables user to scan through a large proportion of image data for elimination of blurry image or picking up a sharp and a nice image in user’s perspective. The thumbnail image is being utilized commonly in camera, smart phone, and other computing devices. In this paper, a method to embed blurry edge information in thumbnail images is proposed. This method is straight forward and simple to be implemented in electronic products. The image will undergo edge width measurement process by finding the local maximum and local minimum locations based on its edge magnitude. This is obtained after the implementation of horizontal and vertical first order derivatives of the original high resolution input image. The blur edges will be emphasized by utilizing edge width information during downsampling process to enable users to identify blurry edge image distinctively. Experimental results show a satisfactory outcome in embedding blurry characteristics of the original image to thumbnail image on the proposed method.

New engineering safety factors for Loviisa NPP core calculations

Energy Technology Data Exchange (ETDEWEB)

Kuopanportti, Jaakko; Saarinen, Simo; Lahtinen, Tuukka; Ekstroem, Karoliina [Fortum Power and Heat Ltd., Fortum (Finland)

2017-09-15

In Loviisa NPP, there are two limiting thermal margins called the enthalpy rise margin and the linear heat rate margin that are monitored during normal operation. Engineering safety factors are applied in determination of both of these factors. The factors take into account the effect of various manufacturing tolerances, impact of the irradiation and simulation uncertainties on the local heat rate and on the enthalpy of the coolant. The engineering factors were re-evaluated during 2015 and the factors were approved by the Finnish radiation and nuclear safety authority in 2016. The re-evaluation was performed by considering all of the identified phenomena that affect the local heat rate or the enthalpy of the coolant. This paper summarizes the work that was performed during the re-evaluation of the engineering safety factors and presents the results for each uncertainty component. The new engineering safety factors are 1.115 for the linear heat rate and 1.100 for the enthalpy rise margin when the old factors were 1.12 and 1.16, respectively. The new factors improve the fuel economy by about 1%.

The PIANC Safety Factor System for Breakwaters

DEFF Research Database (Denmark)

Burcharth, H. F.

2000-01-01

The paper presents a summary of the recommendations for implementation of safety in breakwater designs given by the PIANC PTC IT Working Group No 12 on Analysis of Rubble Mound Breakwaters with Vertical and Inclined Concrete Walls. The working groups developed for the most important failure modes...... a system of partial safety factors which facilitate design to any target safety level....

Transcatheter Treatment of Tricuspid Regurgitation Using Edge-to-Edge Repair: Procedural Results, Clinical Implications and Predictors for Success.

Science.gov (United States)

Lurz, Philipp; Besler, Christian; Noack, Thilo; Forner, Anna Flo; Bevilacqua, Carmine; Seeburger, Joerg; Rommel, Karl-Philipp; Blazek, Stephan; Hartung, Philipp; Zimmer, Marion; Mohr, Friedrich; Schuler, Gerhard; Linke, Axel; Ender, Joerg; Thiele, Holger

2018-04-10

To analyze the feasibility, safety and effectiveness of Tricuspid valve (TV) repair using the MitraClip system in patients at high surgical risk. Forty-two elderly high-risk patients (76.8±7.3 years, EuroScore II 8.1±5.7) with isolated TR or combined TR and mitral regurgitation (MR) underwent edge-to-edge repair of the TV (n=11) or combined edge-to-edge repair of the TV and mitral valve (n=31). Procedural details, success rate, impact on TR severity and predictors for success at 30 day follow-up were analyzed. Successful edge-to-edge repair of TR was achieved in 35/42 patients (83%, 68 clips in total, 94% in the anteroseptal commissure, 6% in the posteroseptal commissure). In 5 patients, grasping of the leaflets was impossible and two patients had no decrease in TR after clipping. In those with procedural success, clipping of the TV led to a reduction in effective regurgitant orifice area by -62,5 % (from 0.8±0.4 to 0.3±0.2 cm2; pEdge-to-edge repair of the TV is feasible with promising reduction in TR, which could result in clinical improvement.

Analysis of factors influencing safety management for metro construction in China.

Science.gov (United States)

Yu, Q Z; Ding, L Y; Zhou, C; Luo, H B

2014-07-01

With the rapid development of urbanization in China, the number and size of metro construction projects are increasing quickly. At the same time, and increasing number of accidents in metro construction make it a disturbing focus of social attention. In order to improve safety management in metro construction, an investigation of the participants' perspectives on safety factors in China metro construction has been conducted to identify the key safety factors, and their ranking consistency among the main participants, including clients, consultants, designers, contractors and supervisors. The result of factor analysis indicates that there are five key factors which influence the safety of metro construction including safety attitude, construction site safety, government supervision, market restrictions and task unpredictability. In addition, ANOVA and Spearman rank correlation coefficients were performed to test the consistency of the means rating and the ranking of safety factors. The results indicated that the main participants have significant disagreement about the importance of safety factors on more than half of the items. Suggestions and recommendations on practical countermeasures to improve metro construction safety management in China are proposed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Weight functions for the determination of stress intensity factor and T-stress for edge-cracked plates with built-in ends

International Nuclear Information System (INIS)

Li, J.; Wang, X.; Tan, C.L.

2004-01-01

This paper presents the weight functions for the determination of the stress intensity factor and T-stress solutions for edge-cracked plates with built-in ends under complex stress distributions. First, a compliance analysis approach is used to calculate stress intensity factor and T-stress for edge cracks in finite width plates with built-in ends with uniform or linear stress distributions acting on the crack face. The results serve as the reference solutions for the next step in which the approaches of deriving weight functions from reference stress intensity factor and T-stress solutions developed for stress boundary conditions are extended to obtain the corresponding weight functions for edge-cracked plates with built-in ends. Finite element analysis is conducted to validate the derived solutions. The weight functions derived are suitable for obtaining stress intensity factors and T-stress solutions under any complex stress field

mathematical models for prediction of safety factors for a simply

African Journals Online (AJOL)

HOD

Keywords: reliability, code calibration, load factor, safety factor, design, steel beam. 1. INTRODUCTION ... safety factors for the design of a simply supported steel beam using regression .... 5 design criteria for a solid timber portal frame.

SafetyNet. Human factors safety training on the Internet

DEFF Research Database (Denmark)

Hauland, G.; Pedrali, M.

2002-01-01

This report describes user requirements to an Internet based distance learning system of human factors training, i.e. the SafetyNet prototype, within the aviation (pilots and air traffic control), maritime and medical domains. User requirements totraining have been elicited through 19 semi...

Predictions of the near edge transport shortfall in DIII-D L-mode plasmas using the trapped gyro-Landau-fluid model

Energy Technology Data Exchange (ETDEWEB)

Kinsey, J. E. [CompX, P.O. Box 2672, Del Mar, California 92014 (United States); Staebler, G. M.; Candy, J.; Petty, C. C.; Waltz, R. E. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Rhodes, T. L. [Physics Department and PSTI, University of California, Los Angeles, California 90095 (United States)

2015-01-15

Previous studies of DIII-D L-mode plasmas have shown that a transport shortfall exists in that our current models of turbulent transport can significantly underestimate the energy transport in the near edge region. In this paper, the Trapped Gyro-Landau-Fluid (TGLF) drift wave transport model is used to simulate the near edge transport in a DIII-D L-mode experiment designed to explore the impact of varying the safety factor on the shortfall. We find that the shortfall systematically increases with increasing safety factor and is more pronounced for the electrons than for the ions. Within the shortfall dataset, a single high current case has been found where no transport shortfall is predicted. Reduced neutral beam injection power has been identified as the key parameter separating this discharge from other discharges exhibiting a shortfall. Further analysis shows that the energy transport in the L-mode near edge region is not stiff according to TGLF. Unlike the H-mode core region, the predicted temperature profiles are relatively more responsive to changes in auxiliary heating power. In testing the fidelity of TGLF for the near edge region, we find that a recalibration of the collision model is warranted. A recalibration improves agreement between TGLF and nonlinear gyrokinetic simulations performed using the GYRO code with electron-ion collisions. The recalibration only slightly impacts the predicted shortfall.

Aeroelastic Control of a Segmented Trailing Edge Using Fiber Optic Strain Sensing Technology

Science.gov (United States)

Graham, Corbin Jay; Martins, Benjamin; Suppanade, Nathan

2014-01-01

Currently, design of aircraft structures incorporate a safety factor which is essentially an over design to mitigate the risk of structure failure during operation. Typically this safety factor is to design the structure to withstand loads much greater than what is expected to be experienced during flight. NASA Dryden Flight Research Centers has developed a Fiber Optic Strain Sensing (FOSS) system which can measure strain values in real-time. The Aeroelastics Lab at the AERO Institute is developing a segmented trailing edged wing with multiple control surfaces that can utilize the data from the FOSS system, in conjunction with an adaptive controller to redistribute the lift across a wing. This redistribution can decrease the amount of strain experienced by the wing as well as be used to dampen vibration and reduce flutter.

Failure and factors of safety in piping system design

International Nuclear Information System (INIS)

Antaki, G.A.

1993-01-01

An important body of test and performance data on the behavior of piping systems has led to an ongoing reassessment of the code stress allowables and their safety margin. The codes stress allowables, and their factors of safety, are developed from limits on the incipient yield (for ductile materials), or incipient rupture (for brittle materials), of a test specimen loaded in simple tension. In this paper, we examine the failure theories introduced in the B31 and ASME III codes for piping and their inherent approximations compared to textbook failure theories. We summarize the evolution of factors of safety in ASME and B31 and point out that, for piping systems, it is appropriate to reconsider the concept and definition of factors of safety

Atomic scattering factor of the ASTRO-H (Hitomi) SXT reflector around the gold's L edges

DEFF Research Database (Denmark)

Kikuchi, Naomichi; Kurashima, Sho; Ishida, Manabu

2016-01-01

The atomic scattering factor in the energy range of 11.2-15.4 keV for the ASTRO-H Soft X-ray Telescope (SXT) is reported. The large effective area of the SXT makes use of photon spectra above 10 keV viable, unlike most other X-ray satellites with total-reflection mirror optics. Presence of gold's L-edges...... in the energy band is a major issue, as it complicates the function of the effective area. In order to model the area, the reflectivity measurements in the 11.2-15.4 keV band with the energy pitch of 0.4-0.7 eV were made in the synchrotron beamline Spring-8 BL01B1. We obtained atomic scattering factors f1 and f......2 by the curve fitting to the reflectivities of our witness sample. The edges associated with the L-I, II, and III transitions are identified, of which the depths are found to be roughly 60% shallower than those expected from the Henke's atomic scattering factor....

16 CFR 1211.12 - Requirements for edge sensors.

Science.gov (United States)

2010-01-01

... Section 1211.12 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT... that the axis is perpendicular to the plane of the door. For an edge sensor intended to be used on a... direction perpendicular to the plane of the door. See figure 6. (2) With respect to the test of paragraph (a...

76 FR 35130 - Pipeline Safety: Control Room Management/Human Factors

Science.gov (United States)

2011-06-16

...: Control Room Management/Human Factors AGENCY: Pipeline and Hazardous Materials Safety Administration... the Control Room Management/Human Factors regulations in order to realize the safety benefits sooner... FR 5536). By this amendment to the Control Room Management/Human Factors (CRM) rule, an operator must...

Nuclear safety regulation on nuclear safety equipment activities in relation to human and organizational factors

International Nuclear Information System (INIS)

Li Tianshu

2013-01-01

Based on years of knowledge in nuclear safety supervision and experience of investigating and dealing with violation events in repair welding of DFHM, this paper analyzes major faults in manufacturing and maintaining activities of nuclear safety equipment in relation to human and organizational factors. It could be deducted that human and organizational factors has definitely become key features in the development of nuclear energy and technology. Some feasible measures to reinforce supervision on nuclear safety equipment activities have also been proposed. (author)

29 CFR 1915.73 - Guarding of deck openings and edges.

Science.gov (United States)

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Guarding of deck openings and edges. 1915.73 Section 1915.73 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION..., Ladders and Other Working Surfaces § 1915.73 Guarding of deck openings and edges. (a) The provisions of...

Partial Safety Factors and Target Reliability Level in Danish Structural Codes

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard; Hansen, J. O.; Nielsen, T. A.

2001-01-01

The partial safety factors in the newly revised Danish structural codes have been derived using a reliability-based calibration. The calibrated partial safety factors result in the same average reliability level as in the previous codes, but a much more uniform reliability level has been obtained....... The paper describes the code format, the stochastic models and the resulting optimised partial safety factors....

Factors Contribute to Safety Culture in the Manufacturing Industry in Malaysia

OpenAIRE

Ong Choon Hee

2014-01-01

The purpose of this paper is to explain the role of safety culture in the manufacturing industry in Malaysia and identify factors contribute to safety culture. It is suggested in this study that leadership support, management commitment and safety management system are important factors that contribute to safety culture. This study also provides theoretical implications to guide future research and offers practical implications to the managers in the development of safety culture. Given that ...

Assessment of the factors with significant influence on safety culture

International Nuclear Information System (INIS)

Farcasiu, M.; Nitoi, M.

2013-01-01

In this paper, a qualitative and a quantitative evaluation of the factors with significant impact on safety culture were performed. These techniques were established and applied in accordance with IAEA standards. In order to show the applicability and opportunity of the methodology a specific case study was prepared: safety culture evaluation for INR Pitesti. The qualitative evaluation was performed using specific developed questionnaires. Through analysis of the completed questionnaires was established the development stage of safety culture at INR. The quantitative evaluation was performed using a guide to rate the influence factors. For each factor was identified the influence (negative or positive) and ranking score was estimated using scoring criteria. The results have emphasized safety culture stages. The paper demonstrates the fact that using both quantitative and qualitative assessment techniques, a practical value of the safety culture concept is given. (authors)

Improving Safety through Human Factors Engineering.

Science.gov (United States)

Siewert, Bettina; Hochman, Mary G

2015-10-01

Human factors engineering (HFE) focuses on the design and analysis of interactive systems that involve people, technical equipment, and work environment. HFE is informed by knowledge of human characteristics. It complements existing patient safety efforts by specifically taking into consideration that, as humans, frontline staff will inevitably make mistakes. Therefore, the systems with which they interact should be designed for the anticipation and mitigation of human errors. The goal of HFE is to optimize the interaction of humans with their work environment and technical equipment to maximize safety and efficiency. Special safeguards include usability testing, standardization of processes, and use of checklists and forcing functions. However, the effectiveness of the safety program and resiliency of the organization depend on timely reporting of all safety events independent of patient harm, including perceived potential risks, bad outcomes that occur even when proper protocols have been followed, and episodes of "improvisation" when formal guidelines are found not to exist. Therefore, an institution must adopt a robust culture of safety, where the focus is shifted from blaming individuals for errors to preventing future errors, and where barriers to speaking up-including barriers introduced by steep authority gradients-are minimized. This requires creation of formal guidelines to address safety concerns, establishment of unified teams with open communication and shared responsibility for patient safety, and education of managers and senior physicians to perceive the reporting of safety concerns as a benefit rather than a threat. © RSNA, 2015.

Edge Stenosis After Covered Stenting for Long Superficial Femoral Artery Occlusive Disease: Risk Factor Analysis and Prevention With Drug-Coated Balloon Angioplasty.

Science.gov (United States)

Lin, Ting-Chao; Huang, Chun-Yang; Chen, Po-Lin; Lee, Chiu-Yang; Shih, Chun-Che; Chen, I-Ming

2018-06-01

To report a retrospective analysis of risk factors for edge restenosis after Viabahn stent-graft treatment of superficial femoral artery (SFA) occlusive disease and determine any protective effect of drug-coated balloons (DCBs) used at the time of stent-graft implantation. Between October 2011 and July 2016, 110 patients (mean age 73.3±7.6 years; 78 men) were treated with the Viabahn stent-graft for long SFA occlusions. Thirty-eight (34.5%) patients had DCB reinforcement at the distal edge of the stent-graft. For analysis, the population was divided into groups of no edge stenosis patients (n=88; mean lesion length 22.4±4.2 cm) and edge stenosis patients (n=22; mean lesion length 23.5±5.7 cm). The clinical outcomes, ankle-brachial indices, computed tomography angiography findings, and patency were compared at a minimum of 12 months. Logistic regression analysis was employed to determine risk factors for edge stenosis; the results are presented as the odds ratio (OR) and 95% confidence interval. No differences in clinical or procedural characteristics were identified except the higher incidence of diabetes (p=0.008) and greater need for retrograde access (p=0.033) in the edge stenosis group. DCB reinforcement reduced the incidence of edge stenosis (p=0.021) and target lesion revascularization (TLR; p=0.010) and resulted in a significantly higher 1-year primary patency rate (92.1% vs 76.4%, p=0.042). However, multivariate analysis revealed only poor distal runoff (OR 0.31, 95% CI 0.11 to 0.83, p=0.020) as a predictor of edge stenosis. The risk of edge stenosis after Viabahn implantation was higher in patients with poor distal runoff. DCB reinforcement over the distal edge reduced edge stenosis, decreased 1-year TLR, and improved 1-year primary patency.

Design of Vertical Wall Caisson Breakwaters using Partial Safety Factors

DEFF Research Database (Denmark)

Burcharth, H. F.; Sørensen, John Dalsgaard

1999-01-01

The paper presents a new system for implementation of target reliability in caisson breakwater designs by means of partial safety factors. The development of the system is explained, and tables of partial safety factors are presented for important overall stability failure modes related to caisson...

Properties on the edge: graphene edge energies, edge stresses, edge warping, and the Wulff shape of graphene flakes

International Nuclear Information System (INIS)

Branicio, Paulo S; Jhon, Mark H; Gan, Chee Kwan; Srolovitz, David J

2011-01-01

It has been shown that the broken bonds of an unreconstructed graphene edge generate compressive edge stresses leading to edge warping. Here, we investigate edge energies and edge stresses of graphene nanoribbons with arbitrary orientations from armchair to zigzag, considering both flat and warped edge shapes in the presence and absence of hydrogen. We use the second generation reactive empirical bond order potential to calculate the edge energies and stresses for clean and hydrogenated edges. Using these energies, we perform a Wulff construction to determine the equilibrium shapes of flat graphene flakes as a function of hydrogen chemical potential. While edge stresses for clean, flat edges are compressive, they become tensile if allowed to warp. Conversely, we find that edge energies change little (∼1%) with edge warping. Hydrogenation of the edges virtually eliminates both the edge energy and edge stresses. For warped edges an approximately linear relationship is found between amplitudes and wavelengths. The equilibrium shape of a graphene flake is determined by the value of the hydrogen chemical potential. For very small (and large) values of it the flakes have a nearly hexagonal (dodecagon) shape with zigzag oriented edges, while for intermediate values graphene flakes are found with complex shapes

Leading-edge flow criticality as a governing factor in leading-edge vortex initiation in unsteady airfoil flows

Science.gov (United States)

Ramesh, Kiran; Granlund, Kenneth; Ol, Michael V.; Gopalarathnam, Ashok; Edwards, Jack R.

2018-04-01

A leading-edge suction parameter (LESP) that is derived from potential flow theory as a measure of suction at the airfoil leading edge is used to study initiation of leading-edge vortex (LEV) formation in this article. The LESP hypothesis is presented, which states that LEV formation in unsteady flows for specified airfoil shape and Reynolds number occurs at a critical constant value of LESP, regardless of motion kinematics. This hypothesis is tested and validated against a large set of data from CFD and experimental studies of flows with LEV formation. The hypothesis is seen to hold except in cases with slow-rate kinematics which evince significant trailing-edge separation (which refers here to separation leading to reversed flow on the aft portion of the upper surface), thereby establishing the envelope of validity. The implication is that the critical LESP value for an airfoil-Reynolds number combination may be calibrated using CFD or experiment for just one motion and then employed to predict LEV initiation for any other (fast-rate) motion. It is also shown that the LESP concept may be used in an inverse mode to generate motion kinematics that would either prevent LEV formation or trigger the same as per aerodynamic requirements.

Modelling of safety barriers including human and organisational factors to improve process safety

DEFF Research Database (Denmark)

Markert, Frank; Duijm, Nijs Jan; Thommesen, Jacob

2013-01-01

It is believed that traditional safety management needs to be improved on the aspect of preparedness for coping with expected and unexpected deviations, avoiding an overly optimistic reliance on safety systems. Remembering recent major accidents, such as the Deep Water Horizon, the Texas City....... A valuable approach is the inclusion of human and organisational factors into the simulation of the reliability of the technical system using event trees and fault trees and the concept of safety barriers. This has been demonstrated e.g. in the former European research project ARAMIS (Accidental Risk...

Human factor in the problem of Russian nuclear industry safety

International Nuclear Information System (INIS)

Abramova, V.

2002-01-01

The approach to human factor definition, considered in the paper, consists of recognition of as many as possible factors for developing a complete list of factors, which have influence on mistakes or successful work of NPP personnel. Safety culture is considered as the main factor. The enhancement in nuclear power industry includes an optimization of organizational structures and development of personnel safety attitudes. The organizational factors, as possible root causes for human errors, need to be identified, assessed and improved. The organizational activities taken in Russia are presented

Reliability Analysis and Calibration of Partial Safety Factors for Redundant Structures

DEFF Research Database (Denmark)

Sørensen, John Dalsgaard

1998-01-01

Redundancy is important to include in the design and analysis of structural systems. In most codes of practice redundancy is not directly taken into account. In the paper various definitions of a deterministic and reliability based redundancy measure are reviewed. It is described how reundancy can...... be included in the safety system and how partial safety factors can be calibrated. An example is presented illustrating how redundancy is taken into account in the safety system in e.g. the Danish codes. The example shows how partial safety factors can be calibrated to comply with the safety level...

Mechanisms Driving Galling Success in a Fragmented Landscape: Synergy of Habitat and Top-Down Factors along Temperate Forest Edges.

Directory of Open Access Journals (Sweden)

Nina-S Kelch

Full Text Available Edge effects play key roles in the anthropogenic transformation of forested ecosystems and their biota, and are therefore a prime field of contemporary fragmentation research. We present the first empirical study to address edge effects on the population level of a widespread galling herbivore in a temperate deciduous forest. By analyzing edge effects on abundance and trophic interactions of beech gall midge (Mikiola fagi Htg., we found 30% higher gall abundance in the edge habitat as well as lower mortality rates due to decreased top-down control, especially by parasitoids. Two GLM models with similar explanatory power (58% identified habitat specific traits (such as canopy closure and altitude and parasitism as the best predictors of gall abundance. Further analyses revealed a crucial influence of light exposure (46% on top-down control by the parasitoid complex. Guided by a conceptual framework synthesizing the key factors driving gall density, we conclude that forest edge proliferation of M. fagi is due to a complex interplay of abiotic changes and trophic control mechanisms. Most prominently, it is caused by the microclimatic regime in forest edges, acting alone or in synergistic concert with top-down pressure by parasitoids. Contrary to the prevailing notion that specialists are edge-sensitive, this turns M. fagi into a winner species in fragmented temperate beech forests. In view of the increasing proportion of edge habitats and the documented benefits from edge microclimate, we call for investigations exploring the pest status of this galling insect and the modulators of its biological control.

Patient safety - the role of human factors and systems engineering.

Science.gov (United States)

Carayon, Pascale; Wood, Kenneth E

2010-01-01

Patient safety is a global challenge that requires knowledge and skills in multiple areas, including human factors and systems engineering. In this chapter, numerous conceptual approaches and methods for analyzing, preventing and mitigating medical errors are described. Given the complexity of healthcare work systems and processes, we emphasize the need for increasing partnerships between the health sciences and human factors and systems engineering to improve patient safety. Those partnerships will be able to develop and implement the system redesigns that are necessary to improve healthcare work systems and processes for patient safety.

Patient Safety: The Role of Human Factors and Systems Engineering

Science.gov (United States)

Carayon, Pascale; Wood, Kenneth E.

2011-01-01

Patient safety is a global challenge that requires knowledge and skills in multiple areas, including human factors and systems engineering. In this chapter, numerous conceptual approaches and methods for analyzing, preventing and mitigating medical errors are described. Given the complexity of healthcare work systems and processes, we emphasize the need for increasing partnerships between the health sciences and human factors and systems engineering to improve patient safety. Those partnerships will be able to develop and implement the system redesigns that are necessary to improve healthcare work systems and processes for patient safety. PMID:20543237

Spatiotemporal response of plasma edge density and temperature to non-axisymmetric magnetic perturbations at ASDEX Upgrade

International Nuclear Information System (INIS)

Fischer, R; Fuchs, J C; McDermott, R; Rathgeber, S K; Suttrop, W; Wolfrum, E; Willensdorfer, M

2012-01-01

Non-axisymmetric magnetic perturbations (MPs) were successfully applied at ASDEX Upgrade to substantially reduce the plasma energy loss and peak divertor power load that occur concomitant with type-I edge localized modes (ELMs). The response of electron density edge profiles and temperature and pressure pedestal-top values to MPs are reported. ELM mitigation is observed above an edge density threshold and independent of the MPs being resonant or non-resonant with the edge safety factor. The edge electron collisionality appears not to be appropriate to separate mitigated from non-mitigated discharges for the present high-collisionality plasmas. No significant change in the position or gradient of the edge density profile could be observed for the transition into the ELM-mitigated phase, except from the effect of the three-dimensional MP field which leads to an apparent profile shift. An increase in the density and decrease in the temperature at the pedestal-top balance such that the pressure saturates at the value of the pre-mitigated phase. The plasma stored energy, the normalized plasma pressure, and the H-mode quality factor follow closely the evolution of the pedestal-top pressure and thus remain almost unaffected. The temporal evolution of the ion effective charge shows that the impurity content does not increase although flushing through type-I ELMs is missing. The type-I ELMs are replaced in the mitigated phase by small-scale and high-frequency edge perturbations. The effect of the small bursts on the density profile, which is correlated with a transient increase of the divertor thermoelectric current, is small compared with the effect of the type-I ELMs. The residual scatter of the profiles in the mitigated phase is small directly after the transition into the ELM-mitigated phase and increases again when the pressure saturates at the value of the pre-mitigated phase. (paper)

Global gyrokinetic simulations of the H-mode tokamak edge pedestal

Energy Technology Data Exchange (ETDEWEB)

Wan, Weigang; Parker, Scott E.; Chen, Yang [Department of Physics, University of Colorado, Boulder, Colorado 80309 (United States); Groebner, Richard J. [General Atomics, Post Office Box 85068, San Diego, California 92186 (United States); Yan, Zheng [University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Pankin, Alexei Y.; Kruger, Scott E. [Tech-X Corporation, 5621 Arapahoe Ave., Boulder, Colorado 80305 (United States)

2013-05-15

Global gyrokinetic simulations of DIII-D H-mode edge pedestal show two types of instabilities may exist approaching the onset of edge localized modes: an intermediate-n, high frequency mode which we identify as the “kinetic peeling ballooning mode (KPBM),” and a high-n, low frequency mode. Our previous study [W. Wan et al., Phys. Rev. Lett. 109, 185004 (2012)] has shown that when the safety factor profile is flattened around the steep pressure gradient region, the high-n mode is clearly kinetic ballooning mode and becomes the dominant instability. Otherwise, the KPBM dominates. Here, the properties of the two instabilities are studied by varying the density and temperature profiles. It is found that the KPBM is destabilized by density and ion temperature gradient, and the high-n mode is mostly destabilized by electron temperature gradient. Nonlinear simulations with the KPBM saturate at high levels. The equilibrium radial electric field (E{sub r}) reduces the transport. The effect of the parallel equilibrium current is found to be weak.

Edge responses are different in edges under natural versus anthropogenic influence: a meta-analysis using ground beetles.

Science.gov (United States)

Magura, Tibor; Lövei, Gábor L; Tóthmérész, Béla

2017-02-01

Most edges are anthropogenic in origin, but are distinguishable by their maintaining processes (natural vs. continued anthropogenic interventions: forestry, agriculture, urbanization). We hypothesized that the dissimilar edge histories will be reflected in the diversity and assemblage composition of inhabitants. Testing this "history-based edge effect" hypothesis, we evaluated published information on a common insect group, ground beetles (Coleoptera: Carabidae) in forest edges. A meta-analysis showed that the diversity-enhancing properties of edges significantly differed according to their history. Forest edges maintained by natural processes had significantly higher species richness than their interiors, while edges with continued anthropogenic influence did not. The filter function of edges was also essentially different depending on their history. For forest specialist species, edges maintained by natural processes were penetrable, allowing these species to move right through the edges, while edges still under anthropogenic interventions were impenetrable, preventing the dispersal of forest specialists out of the forest. For species inhabiting the surrounding matrix (open-habitat and generalist species), edges created by forestry activities were penetrable, and such species also invaded the forest interior. However, natural forest edges constituted a barrier and prevented the invasion of matrix species into the forest interior. Preserving and protecting all edges maintained by natural processes, and preventing anthropogenic changes to their structure, composition, and characteristics are key factors to sustain biodiversity in forests. Moreover, the increasing presence of anthropogenic edges in a landscape is to be avoided, as they contribute to the loss of biodiversity. Simultaneously, edges under continued anthropogenic disturbance should be restored by increasing habitat heterogeneity.

Patient safety risk factors in minimally invasive surgery : A validation study

NARCIS (Netherlands)

Rodrigues, S.P.; Ter Kuile, M.; Dankelman, J.; Jansen, F.W.

2012-01-01

This study was conducted to adapt and validate a patient safety (PS) framework for minimally invasive surgery (MIS) as a first step in understanding the clinical relevance of various PS risk factors in MIS. Eight patient safety risk factor domains were identified using frameworks from a systems

Human factors and safety in emergency medicine

Science.gov (United States)

Schaefer, H. G.; Helmreich, R. L.; Scheidegger, D.

1994-01-01

A model based on an input process and outcome conceptualisation is suggested to address safety-relevant factors in emergency medicine. As shown in other dynamic and demanding environments, human factors play a decisive role in attaining high quality service. Attitudes held by health-care providers, organisational shells and work-cultural parameters determine communication, conflict resolution and workload distribution within and between teams. These factors should be taken into account to improve outcomes such as operational integrity, job satisfaction and morale.

To the problem of the statistical basis of evaluation of the mechanical safety factor

International Nuclear Information System (INIS)

Tsyganov, S.V.

2009-01-01

The methodology applied for the safety factor assessment of the WWER fuel cycles uses methods and terms of statistics. Value of the factor is calculated on the basis of estimation of probability to meet predefined limits. Such approach demands the special attention to the statistical properties of parameters of interest. Considering the mechanical constituents of the engineering factor it is assumed uncertainty factors of safety parameters are stochastic values. It characterized by probabilistic distributions that can be unknown. Traditionally in the safety factor assessment process the unknown parameters are estimated from the conservative points of view. This paper analyses how the refinement of the factors distribution parameters is important for the assessment of the mechanical safety factor. For the analysis the statistical approach is applied for modelling of different type of factor probabilistic distributions. It is shown the significant influence of the shape and parameters of distributions for some factors on the value of mechanical safety factor. (Authors)

To the problem of the statistical basis of evaluation of the mechanical safety factor

International Nuclear Information System (INIS)

Tsyganov, S.

2009-01-01

The methodology applied for the safety factor assessment of the VVER fuel cycles uses methods and terms of statistics. Value of the factor is calculated on the basis of estimation of probability to meet predefined limits. Such approach demands the special attention to the statistical properties of parameters of interest. Considering the mechanical constituents of the engineering factor it is assumed uncertainty factors of safety parameters are stochastic values. It characterized by probabilistic distributions that can be unknown. Traditionally in the safety factor assessment process the unknown parameters are estimated from the conservative points of view. This paper analyses how the refinement of the factors distribution parameters is important for the assessment of the mechanical safety factor. For the analysis the statistical approach is applied for modelling of different type of factor probabilistic distributions. It is shown the significant influence of the shape and parameters of distributions for some factors on the value of mechanical safety factor. (author)

Factors impacting on the microbiological quality and safety of ...

African Journals Online (AJOL)

Problems with the safety and shelf life of export hake have been raised by the Namibian fishing industry. This prompted an investigation into the factors that may have an impact on the microbiological quality and safety of processed hake. Samples were collected along the processing line; the general microbiological quality ...

Inverted edge effects on carbon stocks in human-dominated landscapes

Science.gov (United States)

Romitelli, I.; Keller, M.; Vieira, S. A.; Metzger, J. P.; Reverberi Tambosi, L.

2017-12-01

Although the importance of tropical forests to regulate greenhouse gases is well documented, little is known about what factors affect the ability of these forests to store carbon in human-dominated landscapes. Among those factors, the landscape structure, particularly the amount of forest cover, the type of matrix and edge effects, can have important roles. We tested how carbon stock is influenced by a combination of factors of landscape composition (pasture and forest cover), landscape configuration (edge effect) and relief factors (slope, elevation and aspect). To test those relationships, we performed a robust carbon stock estimation with inventory and LiDAR data in human-dominated landscapes from the Brazilian Atlantic forest region. The study area showed carbon stock mean 45.49 ± 9.34 Mg ha-1. The interaction between forest cover, edge effect and slope was the best combination explanatory of carbon stock. We observed an inverted edge effect pattern where carbon stock is higher close to the edges of the studied secondary forests. This inverted edge effect observed contradicts the usual pattern reported in the literature for mature forests. We suppose this pattern is related with a positive effect that edge conditions can have stimulating forest regeneration, but the underlying processes to explain the observed pattern should still be tested. Those results suggest that Carbon stocks in human-dominated and fragmented landscapes can be highly affected by the landscape structure, and particularly that edges conditions can favor carbon sequestration in regenerating tropical forests.

Edge localized mode physics and operational aspects in tokamaks

Energy Technology Data Exchange (ETDEWEB)

Becoulet, M [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Huysmans, G [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Sarazin, Y [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Garbet, X [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Ghendrih, Ph [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Rimini, F [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Joffrin, E [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Litaudon, X [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Monier-Garbet, P [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Ane, J-M [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Thomas, P [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Grosman, A [Association Euratom-CEA, CEA Cadarache, F-13108 St Paul-lez-Durance (France); Parail, V [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Wilson, H [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Lomas, P [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Vries, P de[Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Zastrow, K-D [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Matthews, G F [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Lonnroth, J [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom); Gerasimov, S [Euratom/UKAEA Association, Fusion Culham Science Centre, Abingdon, OX14 3EA (United Kingdom)] [and others

2003-12-01

Recent progress in experimental and theoretical studies of edge localized mode (ELM) physics is reviewed for the reactor relevant plasma regimes, namely the high confinement regimes, that is, H-modes and advanced scenarios. Theoretical approaches to ELM physics, from a linear ideal magnetohydrodynamic (MHD) stability analysis to non-linear transport models with ELMs are discussed with respect to experimental observations, in particular the fast collapse of pedestal pressure profiles, magnetic measurements and scrape-off layer transport during ELMs. High confinement regimes with different types of ELMs are addressed in this paper in the context of development of operational scenarios for ITER. The key parameters that have been identified at present to reduce the energy losses in Type I ELMs are operation at high density, high edge magnetic shear and high triangularity. However, according to the present experimental scaling for the energy losses in Type I ELMs, the extrapolation of such regimes for ITER leads to unacceptably large heat loads on the divertor target plates exceeding the material limits. High confinement H-mode scenarios at high triangularity and high density with small ELMs (Type II), mixed regimes (Type II and Type I) and combined advanced regimes at high beta{sub p} are discussed for present-day tokamaks. The optimum combination of high confinement and small MHD activity at the edge in Type II ELM scenarios is of interest to ITER. However, to date, these regimes have been achieved in a rather narrow operational window and far from ITER parameters in terms of collisionality, edge safety factor and beta{sub p}. The compatibility of the alternative internal transport barrier (ITB) scenario with edge pedestal formation and ELMs is also addressed. Edge physics issues related to the possible combination of small benign ELMs (Type III, Type II ELMs, quiescent double barrier) and high performance ITBs are discussed for present-day experiments (JET, JT-60U

Edge localized mode physics and operational aspects in tokamaks

International Nuclear Information System (INIS)

Becoulet, M; Huysmans, G; Sarazin, Y; Garbet, X; Ghendrih, Ph; Rimini, F; Joffrin, E; Litaudon, X; Monier-Garbet, P; Ane, J-M; Thomas, P; Grosman, A; Parail, V; Wilson, H; Lomas, P; Vries, P de; Zastrow, K-D; Matthews, G F; Lonnroth, J; Gerasimov, S; Sharapov, S; Gryaznevich, M; Counsell, G; Kirk, A; Valovic, M; Buttery, R; Loarte, A; Saibene, G; Sartori, R; Leonard, A; Snyder, P; Lao, L L; Gohil, P; Evans, T E; Moyer, R A; Kamada, Y; Chankin, A; Oyama, N; Hatae, T; Asakura, N; Tudisco, O; Giovannozzi, E; Crisanti, F; Perez, C P; Koslowski, H R; Eich, T; Sips, A; Horton, L; Hermann, A; Lang, P; Stober, J; Suttrop, W; Beyer, P; Saarelma, S

2003-01-01

Recent progress in experimental and theoretical studies of edge localized mode (ELM) physics is reviewed for the reactor relevant plasma regimes, namely the high confinement regimes, that is, H-modes and advanced scenarios. Theoretical approaches to ELM physics, from a linear ideal magnetohydrodynamic (MHD) stability analysis to non-linear transport models with ELMs are discussed with respect to experimental observations, in particular the fast collapse of pedestal pressure profiles, magnetic measurements and scrape-off layer transport during ELMs. High confinement regimes with different types of ELMs are addressed in this paper in the context of development of operational scenarios for ITER. The key parameters that have been identified at present to reduce the energy losses in Type I ELMs are operation at high density, high edge magnetic shear and high triangularity. However, according to the present experimental scaling for the energy losses in Type I ELMs, the extrapolation of such regimes for ITER leads to unacceptably large heat loads on the divertor target plates exceeding the material limits. High confinement H-mode scenarios at high triangularity and high density with small ELMs (Type II), mixed regimes (Type II and Type I) and combined advanced regimes at high beta p are discussed for present-day tokamaks. The optimum combination of high confinement and small MHD activity at the edge in Type II ELM scenarios is of interest to ITER. However, to date, these regimes have been achieved in a rather narrow operational window and far from ITER parameters in terms of collisionality, edge safety factor and beta p . The compatibility of the alternative internal transport barrier (ITB) scenario with edge pedestal formation and ELMs is also addressed. Edge physics issues related to the possible combination of small benign ELMs (Type III, Type II ELMs, quiescent double barrier) and high performance ITBs are discussed for present-day experiments (JET, JT-60U, DIII-D) in

Evaluating the impact of grade crossing safety factors through signal detection theory

Science.gov (United States)

2012-10-22

The purpose of this effort was to apply signal detection theory to descriptively model the impact : of five grade crossing safety factors to understand their effect on driver decision making. The : safety factors consisted of: improving commercial mo...

Studying the Relationship between Individual and Organizational Factors and Nurses' Perception of Patient Safety Culture

Directory of Open Access Journals (Sweden)

Farahnaz Abdolahzadeh

2012-11-01

Full Text Available Introduction: Safety culture is considered as an important factor in improving patient safety. Therefore, identifying individual and organizational factors affecting safety culture is crucial. This study was carried out to determine individual and organizational factors associated with nurses' perception of patient safety culture. Methods: The present descriptive study included 940 nurses working in four training hospitals affiliated with Urmia University of Medical Sciences (Iran. Data was collected through the self-report questionnaire of patient safety culture. Descriptive (number, percent, mean, and standard deviation and inferential (t-test and analysis of variance statistics were used to analyze the data in SPSS. Results: Nurses' perception of patient safety culture was significantly correlated with marital status, workplace, and overtime hours. Conclusion: The results of this study revealed that some individual and organizational factors can impact on nurses' perception of patient safety culture. Nursing authorities should thus pay more attention to factors which promote patient safety culture and ultimately the safety of provided services.

Human factors in safety assessment. Safety culture assessment

International Nuclear Information System (INIS)

Zhang Li; Deng Zhiliang; Wang Yiqun; Huang Weigang

1996-01-01

This paper analyses the present conditions and problems in enterprises safety assessment, and introduces the characteristics and effects of safety culture. The authors think that safety culture must be used as a 'soul' to form the pattern of modern safety management. Furthermore, they propose that the human safety and synthetic safety management assessment in a system should be changed into safety culture assessment. Finally, the assessment indicators are discussed

Human factors and systems engineering approach to patient safety for radiotherapy.

Science.gov (United States)

Rivera, A Joy; Karsh, Ben-Tzion

2008-01-01

The traditional approach to solving patient safety problems in healthcare is to blame the last person to touch the patient. But since the publication of To Err is Human, the call has been instead to use human factors and systems engineering methods and principles to solve patient safety problems. However, an understanding of the human factors and systems engineering is lacking, and confusion remains about what it means to apply their principles. This paper provides a primer on them and their applications to patient safety.

Human Factors and Systems Engineering Approach to Patient Safety for Radiotherapy

International Nuclear Information System (INIS)

Rivera, A. Joy; Karsh, Ben-Tzion

2008-01-01

The traditional approach to solving patient safety problems in healthcare is to blame the last person to touch the patient. But since the publication of To Err is Human, the call has been instead to use human factors and systems engineering methods and principles to solve patient safety problems. However, an understanding of the human factors and systems engineering is lacking, and confusion remains about what it means to apply their principles. This paper provides a primer on them and their applications to patient safety

Modelling of Safety Factors in the Design of GRP Composite Products

DEFF Research Database (Denmark)

Babu, B.J.C.; Prabhakaran, R.T. Durai; Lystrup, Aage

2010-01-01

as independent, while in real applications these factors may interact/influence each other. Following the concept developed by the authors, a simple graph theoretic model has been used to determine overall factor of safety. This is described with the help of an example and it has been demonstrated......An attempt has been made in this paper to arrive at the safety factor design of glass fibre reinforced polymer (GRP) composite products using graph theoretic model. In the conventional design and recommendations of the standards, these design factors affecting properties have been considered...

Survey of factors associated with nurses' perception of patient safety.

Science.gov (United States)

Park, Sun A; Lee, Sui Jin; Choi, Go Un

2011-01-01

To describe the nurses' perception of hospital organization related to cultural issues on the safety of the patient and reporting medical errors. In addition, to identify factors associated with the safety of the patient and the nurse. A survey conducted during December 2008-Jannuary 2009, with 126 nurses using the Korean version of the AHRQ patient safety survey, a self-report 5-point Likert scale. Stata 10.0 was used for descriptive analysis, ANOVA (Analysis of variance) and logistic regression. National Cancer Center in Korea. The means for a working environment related to patient safety was 3.4 (±0.62). The associated factors of duration were at a present hospital, a special area, and direct contact with patients. Among organizational culture factors related to patient safety, the means were 3.81(±0.54) for the boss/manager's perception of patient safety and 3.37(±0.49) for the cooperation/collaboration between units. The frequent number of errors reported by nurses were 1~2(22.2%) times over the past 12 months. For incidence reporting, the items that the 'nurses perceived for communication among clinicians as fair' had a means of 3.23(±0.40) and the 'overall evaluation of patient safety was a good' 3.34(±0.73). The nurses' perception of cooperation and collaboration between units were associated with the direct contact between the patient and the nurse. The frequency of incidence reporting was associated with the duration of working hours at the present hospital and also their work experience. The nurses' perception of hospital environment, organizational culture, and incidence reporting was above average and mostly associated with organizational culture.

Variation in Local-Scale Edge Effects: Mechanisms and landscape Context

Science.gov (United States)

Therese M. Donovan; Peter W. Jones; Elizabeth M. Annand; Frank R. Thompson III

1997-01-01

Ecological processes near habitat edges often differ from processes away from edges. Yet, the generality of "edge effects" has been hotly debated because results vary tremendously. To understand the factors responsible for this variation, we described nest predation and cowbird distribution patterns in forest edge and forest core habitats on 36 randomly...

The scaling of edge parameters in jet with plasma input power

International Nuclear Information System (INIS)

Erents, S.K.; McCracken, G.M.; Harbour, P.J.; Clement, S.; Summers, D.D.R.; Tagle, J.A.; Kock, L. de

1989-01-01

The scaling of edge parameters of density and temperature with central density and ohmic power in JET has been presented previously for the discrete limiter geometry and more recently for the new belt limiter configuration. However, the scaling with plasma current (I p ) is difficult to interpret because varying I p does not only change the input power but also the safety factor qs and consequently the SOL thickness. The use of additional heating at constant current allows more direct observation of the effects of changing heating power. In this paper we present data in which the plasma input power is increased by ICRH, (Pt<20MW), using a 3MA target plasma, and compare data for different plasma currents using discrete and belt limiter geometries. Edge data is presented from Langmuir probes in tiles at the top of the torus, when the tokamak is operated in single null magnetic separatrix (divertor) mode, as well as for probes in the main plasma boundary to contrast these data with limiter data. (author) 3 refs., 4 figs

A cross-cultural study of organizational factors on safety: Japanese vs. Taiwanese oil refinery plants.

Science.gov (United States)

Hsu, Shang Hwa; Lee, Chun-Chia; Wu, Muh-Cherng; Takano, Kenichi

2008-01-01

This study attempts to identify idiosyncrasies of organizational factors on safety and their influence mechanisms in Taiwan and Japan. Data were collected from employees of Taiwanese and Japanese oil refinery plants. Results show that organizational factors on safety differ in the two countries. Organizational characteristics in Taiwanese plants are highlighted as: higher level of management commitment to safety, harmonious interpersonal relationship, more emphasis on safety activities, higher devotion to supervision, and higher safety self-efficacy, as well as high quality of safety performance. Organizational characteristics in Japanese plants are highlighted as: higher level of employee empowerment and attitude towards continuous improvement, more emphasis on systematic safety management approach, efficient reporting system and teamwork, and high quality of safety performance. The casual relationships between organizational factors and workers' safety performance were investigated using structural equation modeling (SEM). Results indicate that the influence mechanisms of organizational factors in Taiwan and Japan are different. These findings provide insights into areas of safety improvement in emerging countries and developed countries respectively.

Factor Analysis and Framework Development for Incorporating Public Trust on Nuclear Safety issues

Energy Technology Data Exchange (ETDEWEB)

Cho, Seongkyung; Lee, Gyebong [The Myongji Univ., Seoul (Korea, Republic of); Lee, Gihyung; Lee, Gyehwi; Jeong, Jina [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2014-05-15

The Korea Institute of Nuclear Safety (KINS), a regulatory expert organization in charge of nuclear safety in Korea, realized that a more fundamental and systematic analysis of activities is needed to actively meet the greater variety of concerns people have and increase the reliability of the results of regulation. Nuclear safety, a highly specialized field, has previously been discussed primarily from the viewpoint of the engineers who deal with the technology, but now 'public trust in nuclear safety' has to be viewed from the standpoint of the general public and from the socio-cultural perspective. Specific measures must be taken to examine which factors affect public trust and how we can secure and reproduce those factors to gain it. Also, an efficient system for incorporating public trust in nuclear safety must be established. In this study, various case studies were examined to identify the factors that affect public trust in nuclear safety. First, nuclear safety laws and information disclosure systems of major countries were examined by investigating data and conducting in-depth interviews. To explore a public framework concerning nuclear safety, big data of social media were analyzed. Also, Q methodology was used to analyze the risk schemata of the opinion leaders living in areas near nuclear power plants. Several surveys were conducted to analyze the amount of trust the public had in nuclear safety as well as their awareness of nuclear safety issues. Based on these analyses, factors affecting public trust in nuclear safety were extracted, and measures to build systems incorporating public trust in nuclear safety were proposed. This study addresses the public trust in nuclear safety on condition that the safety is ensured technically and mechanically.

Factor Analysis and Framework Development for Incorporating Public Trust on Nuclear Safety issues

International Nuclear Information System (INIS)

Cho, Seongkyung; Lee, Gyebong; Lee, Gihyung; Lee, Gyehwi; Jeong, Jina

2014-01-01

The Korea Institute of Nuclear Safety (KINS), a regulatory expert organization in charge of nuclear safety in Korea, realized that a more fundamental and systematic analysis of activities is needed to actively meet the greater variety of concerns people have and increase the reliability of the results of regulation. Nuclear safety, a highly specialized field, has previously been discussed primarily from the viewpoint of the engineers who deal with the technology, but now 'public trust in nuclear safety' has to be viewed from the standpoint of the general public and from the socio-cultural perspective. Specific measures must be taken to examine which factors affect public trust and how we can secure and reproduce those factors to gain it. Also, an efficient system for incorporating public trust in nuclear safety must be established. In this study, various case studies were examined to identify the factors that affect public trust in nuclear safety. First, nuclear safety laws and information disclosure systems of major countries were examined by investigating data and conducting in-depth interviews. To explore a public framework concerning nuclear safety, big data of social media were analyzed. Also, Q methodology was used to analyze the risk schemata of the opinion leaders living in areas near nuclear power plants. Several surveys were conducted to analyze the amount of trust the public had in nuclear safety as well as their awareness of nuclear safety issues. Based on these analyses, factors affecting public trust in nuclear safety were extracted, and measures to build systems incorporating public trust in nuclear safety were proposed. This study addresses the public trust in nuclear safety on condition that the safety is ensured technically and mechanically

Edge loading in metal-on-metal hips: low clearance is a new risk factor.

Science.gov (United States)

Underwood, Richard J; Zografos, Angelos; Sayles, Ritchie S; Hart, Alister; Cann, Philippa

2012-03-01

The revision rate of large head metal-on-metal and resurfacing hips are significantly higher than conventional total hip replacements. The revision of these components has been linked to high wear caused by edge loading; which occurs when the head-cup contact patch extends over the cup rim. There are two current explanations for this; first, there is loss of entrainment of synovial fluid resulting in breakdown of the lubricating film and second, edge loading results in a large local increase in contact pressure and consequent film thickness reduction at the cup rim, which causes an increase in wear. This paper develops a method to calculate the distance between the joint reaction force vector and the cup rim--the contact patch centre to rim (CPCR) distance. However, the critical distance for the risk of edge loading is the distance from the contact patch edge to rim (CPER) distance. An analysis of explanted hip components, divided into edge worn and non-edge-worn components showed that there was no statistical difference in CPCR values, but the CPER value was significantly lower for edge worn hips. Low clearance hips, which have a more conformal contact, have a larger diameter contact patch and thus are more at risk of edge loading for similarly positioned hips.

Factors associated with the enactment of safety belt and motorcycle helmet laws.

Science.gov (United States)

Law, Teik Hua; Noland, Robert B; Evans, Andrew W

2013-07-01

It has been shown that road safety laws, such as motorcycle helmet and safety belt laws, have a significant effect in reducing road fatalities. Although an expanding body of literature has documented the effects of these laws on road safety, it remains unclear which factors influence the likelihood that these laws are enacted. This study attempts to identify the factors that influence the decision to enact safety belt and motorcycle helmet laws. Using panel data from 31 countries between 1963 and 2002, our results reveal that increased democracy, education level, per capita income, political stability, and more equitable income distribution within a country are associated with the enactment of road safety laws. © 2012 Society for Risk Analysis.

A Study on the Holding Capacity Safety Factors for Torpedo Anchors

Directory of Open Access Journals (Sweden)

Luís V. S. Sagrilo

2012-01-01

Full Text Available The use of powerful numerical tools based on the finite-element method has been improving the prediction of the holding capacity of fixed anchors employed by the offshore oil industry. One of the main achievements of these tools is the reduction of the uncertainty related to the holding capacity calculation of these anchors. Therefore, it is also possible to reduce the values of the associated design safety factors, which have been calibrated relying on models with higher uncertainty, without impairing the original level of structural safety. This paper presents a study on the calibration of reliability-based safety factors for the design of torpedo anchors considering the statistical model uncertainty evaluated using results from experimental tests and their correspondent finite-element-based numerical predictions. Both working stress design (WSD and load and resistance factors design (LRFD design methodologies are investigated. Considering the WSD design methodology, the single safety is considerably lower than the value typically employed in the design of torpedo anchors. Moreover, a LRFD design code format for torpedo anchors is more appropriate since it leads to designs having less-scattered safety levels around the target value.

A quantitative assessment of organizational factors affecting safety using a system dynamics model

International Nuclear Information System (INIS)

Yoo, J. K.; Yoon, T. S.

2003-01-01

The purpose of this study is to develop a system dynamics model for the assessment of organizational and human factors in the nuclear power plant safety. Previous studies are classified into two major approaches. One is the engineering approach such as ergonomics and Probabilistic Safety Assessment (PSA). The other is socio-psychology one. Both have contributed to find organizational and human factors and increased nuclear safety However, since these approaches assume that the relationship among factors is independent they do not explain the interactions between factors or variables in NPP's. To overcome these restrictions, a system dynamics model, which can show causal relations between factors and quantify organizational and human factors, has been developed. Operating variables such as degree of leadership, adjustment of number of employee, and workload in each department, users can simulate various situations in nuclear power plants in the organization side. Through simulation, user can get an insight to improve safety in plants and to find managerial tools in the organization and human side

Patient safety in the operating room: an intervention study on latent risk factors

Directory of Open Access Journals (Sweden)

van Beuzekom Martie

2012-06-01

Full Text Available Abstract Background Patient safety is one of the greatest challenges in healthcare. In the operating room errors are frequent and often consequential. This article describes an approach to a successful implementation of a patient safety program in the operating room, focussing on latent risk factors that influence patient safety. We performed an intervention to improve these latent risk factors (LRFs and increase awareness of patient safety issues amongst OR staff. Methods Latent risk factors were studied using a validated questionnaire applied to the OR staff before and after an intervention. A pre-test/post-test control group design with repeated measures was used to evaluate the effects of the interventions. The staff from one operating room of an university hospital acted as the intervention group. Controls consisted of the staff of the operating room in another university hospital. The outcomes were the changes in LRF scores, perceived incident rate, and changes in incident reports between pre- and post-intervention. Results Based on pre-test scores and participants’ key concerns about organizational factors affecting patient safety in their department the intervention focused on the following LRFs: Material Resources, Training and Staffing Recourses. After the intervention, the intervention operating room - compared to the control operating room - reported significantly fewer problems on Material Resources and Staffing Resources and a significantly lower score on perceived incident rate. The contribution of technical factors to incident causation decreased significantly in the intervention group after the intervention. Conclusion The change of state of latent risk factors can be measured using a patient safety questionnaire aimed at these factors. The change of the relevant risk factors (Material and Staffing resources concurred with a decrease in perceived and reported incident rates in the relevant categories. We conclude that

Consensus achievement of leadership, organisational and individual factors that influence safety climate: Implications for nursing management.

Science.gov (United States)

Fischer, Shelly A; Jones, Jacqueline; Verran, Joyce A

2018-01-01

To validate a framework of factors that influence the relationship of transformational leadership and safety climate, and to enable testing of safety chain factors by generating hypotheses regarding their mediating and moderating effects. Understanding the patient safety chain and mechanisms by which leaders affect a strong climate of safety is essential to transformational leadership practice, education, and research. A systematic review of leadership and safety literature was used to develop an organising framework of factors proposed to influence the climate of safety. A panel of 25 international experts in leadership and safety engaged a three-round modified Delphi study with Likert-scored surveys. Eighty per cent of participating experts from six countries were retained to the final survey round. Consensus (>66% agreement) was achieved on 40 factors believed to influence safety climate in the acute care setting. Consensus regarding specific factors that play important roles in an organisation's climate of safety can be reached. Generally, the demonstration of leadership commitment to safety is key to cultivating a culture of patient safety. Transformational nurse leaders should consider and employ all three categories of factors in daily leadership activities and decision-making to drive a strong climate of patient safety. © 2017 John Wiley & Sons Ltd.

Effects of the safety factor on ion temperature gradient modes

International Nuclear Information System (INIS)

Wang, A.K.; Dong, J.Q.; Sanuki, H.; Itoh, K.

2003-01-01

A model for the ion temperature gradient (ITG) driven instability is derived from Braginskii magnetohydrodynamic equations of ions. The safety factor q in a toroidal plasma is introduced into the model through the current density J parallel . The effects of q or J parallel on both the ITG instability in k perpendicular and k parallel spectra and the critical stability thresholds are studied. It is shown that the current density // J or the safety factor q plays an important role in stabilizing the ITG instability. (author)

Strain-activated edge reconstruction of graphene nanoribbons

KAUST Repository

Cheng, Yingchun

2012-02-17

The edge structure and width of graphene nanoribbons (GNRs) are crucial factors for the electronic properties. A combination of experiment and first-principles calculations allows us to determine the mechanism of the hexagon-hexagon to pentagon-heptagon transformation. GNRs thinner than 2 nm have been fabricated by bombardment of graphene with high-energetic Au clusters. The edges of the GNRs are modified in situ by electron irradiation. Tensile strain along the edge decreases the transformation energy barrier. Antiferromagnetism and a direct band gap are found for a zigzag GNR, while a fully reconstructed GNR shows an indirect band gap. A GNR reconstructed on only one edge exhibits ferromagnetism. We propose that strain is an effective method to tune the edge and, therefore, the electronic structure of thin GNRs for graphene-based electronics.

Strain-activated edge reconstruction of graphene nanoribbons

KAUST Repository

Cheng, Yingchun; Han, Yu; Schwingenschlö gl, Udo; Wang, H. T.; Zhang, Xixiang; Zhu, Y. H.; Zhu, Zhiyong

2012-01-01

The edge structure and width of graphene nanoribbons (GNRs) are crucial factors for the electronic properties. A combination of experiment and first-principles calculations allows us to determine the mechanism of the hexagon-hexagon to pentagon-heptagon transformation. GNRs thinner than 2 nm have been fabricated by bombardment of graphene with high-energetic Au clusters. The edges of the GNRs are modified in situ by electron irradiation. Tensile strain along the edge decreases the transformation energy barrier. Antiferromagnetism and a direct band gap are found for a zigzag GNR, while a fully reconstructed GNR shows an indirect band gap. A GNR reconstructed on only one edge exhibits ferromagnetism. We propose that strain is an effective method to tune the edge and, therefore, the electronic structure of thin GNRs for graphene-based electronics.

Relationship between organizational factors, safety culture and PSA in nuclear power plant operations

International Nuclear Information System (INIS)

Joksimovich, V.; Orvis, D.D.

1997-01-01

There are four nuclear safety imperatives or ''4Ms'': machine (hardware, design, QA/QC), milieux (operating conditions, environment, natural phenomena), man (human reliability) and management (organizational and management influences). Nuclear safety evaluations as well as evolution of its most powerful tool, Probabilistic Safety Assessment (PSA), followed chronologically the 4M constituents. The nuclear industry worldwide, and the nuclear safety regulators in particular, have been preoccupied with the first M almost to the point of obsession with belated and only intuitive interest in the third and fourth M (human dimension). Human factors or economics in the nuclear industry was an afterthought. Human reliability was essentially born in the aftermath of the Three Mile Island (TMI) accident. Impact of organizational factors on nuclear safety is only in the early stages of R and D. This paper describes some of the concepts being pursued by APG to link organizational factors and safety culture to Human Reliability Analysis (HRA) and to integrate such into probabilistic safety assessment (PSA), e.g. [APG, 1993]. (author). 11 refs, 4 figs, 1 tab

Safety climate in university and college laboratories: impact of organizational and individual factors.

Science.gov (United States)

Wu, Tsung-Chih; Liu, Chi-Wei; Lu, Mu-Chen

2007-01-01

Universities and colleges serve to be institutions of education excellence; however, problems in the areas of occupational safety may undermine such goals. Occupational safety must be the concern of every employee in the organization, regardless of job position. Safety climate surveys have been suggested as important tools for measuring the effectiveness and improvement direction of safety programs. Thus, this study aims to investigate the influence of organizational and individual factors on safety climate in university and college laboratories. Employees at 100 universities and colleges in Taiwan were mailed a self-administered questionnaire survey; the response rate was 78%. Multivariate analysis of variance revealed that organizational category of ownership, the presence of a safety manager and safety committee, gender, age, title, accident experience, and safety training significantly affected the climate. Among them, accident experience and safety training affected the climate with practical significance. The authors recommend that managers should address important factors affecting safety issues and then create a positive climate by enforcing continuous improvements.

Stability of edge states and edge magnetism in graphene nanoribbons

OpenAIRE

Kunstmann, Jens; Özdoğan, Cem; Quandt, Alexander; Fehske, Holger

2010-01-01

We critically discuss the stability of edge states and edge magnetism in zigzag edge graphene nanoribbons (ZGNRs). We point out that magnetic edge states might not exist in real systems, and show that there are at least three very natural mechanisms - edge reconstruction, edge passivation, and edge closure - which dramatically reduce the effect of edge states in ZGNRs or even totally eliminate them. Even if systems with magnetic edge states could be made, the intrinsic magnetism would not be ...

A report on human factors in nuclear safety

International Nuclear Information System (INIS)

1983-03-01

Following the Three Mile Island incident of 1979, studies were undertaken by the Atomic Energy Control Board (AECB), in-house and through outside consultants, to address the role of human factors in the regulatory process. This report by the Advisory Committee on Nuclear Safety (ACNS) comments briefly on these studies and offers suggestions which would promote a more formal treatment of human factors by the AECB

A model for managing edge effects in harvest scheduling using spatial optimization

Science.gov (United States)

Kai L. Ross; Sándor F. Tóth

2016-01-01

Actively managed forest stands can create new forest edges. If left unchecked over time and across space, forest operations such as clear-cuts can create complex networks of forest edges. Newly created edges alter the landscape and can affect many environmental factors. These altered environmental factors have a variety of impacts on forest growth and structure and can...

Classification analysis of organization factors related to system safety

International Nuclear Information System (INIS)

Liu Huizhen; Zhang Li; Zhang Yuling; Guan Shihua

2009-01-01

This paper analyzes the different types of organization factors which influence the system safety. The organization factor can be divided into the interior organization factor and exterior organization factor. The latter includes the factors of political, economical, technical, law, social culture and geographical, and the relationships among different interest groups. The former includes organization culture, communication, decision, training, process, supervision and management and organization structure. This paper focuses on the description of the organization factors. The classification analysis of the organization factors is the early work of quantitative analysis. (authors)

Mathematical models for prediction of safety factors for a simply ...

African Journals Online (AJOL)

From the results obtained, mathematical prediction models were developed using a least square regression analysis for bending, shear and deflection modes of failure considered in the study. The results showed that the safety factors for material, dead and live load are not unique, but they are influenced by safety index ...

A quantitative assessment of organizational factors affecting safety using a system dynamics model

Energy Technology Data Exchange (ETDEWEB)

Yoo, J. K. [Systemix Company, Seoul (Korea, Republic of); Yoon, T. S. [Korea Electric Power Research Institute (Korea, Republic of)

2003-07-01

The purpose of this study is to develop a system dynamics model for the assessment of organizational and human factors in the nuclear power plant safety. Previous studies are classified into two major approaches. One is the engineering approach such as ergonomics and Probabilistic Safety Assessment (PSA). The other is socio-psychology one. Both have contributed to find organizational and human factors and increased nuclear safety However, since these approaches assume that the relationship among factors is independent they do not explain the interactions between factors or variables in NPP's. To overcome these restrictions, a system dynamics model, which can show causal relations between factors and quantify organizational and human factors, has been developed. Operating variables such as degree of leadership, adjustment of number of employee, and workload in each department, users can simulate various situations in nuclear power plants in the organization side. Through simulation, user can get an insight to improve safety in plants and to find managerial tools in the organization and human side.

Two-Dimensional Edge Detection by Guided Mode Resonant Metasurface

Science.gov (United States)

Saba, Amirhossein; Tavakol, Mohammad Reza; Karimi-Khoozani, Parisa; Khavasi, Amin

2018-05-01

In this letter, a new approach to perform edge detection is presented using an all-dielectric CMOS-compatible metasurface. The design is based on guided-mode resonance which provides a high quality factor resonance to make the edge detection experimentally realizable. The proposed structure that is easy to fabricate, can be exploited for detection of edges in two dimensions due to its symmetry. Also, the trade-off between gain and resolution of edge detection is discussed which can be adjusted by appropriate design parameters. The proposed edge detector has also the potential to be used in ultrafast analog computing and image processing.

Organizational factors and nuclear power plant safety

International Nuclear Information System (INIS)

Haber, S.B.

1995-01-01

There are many organizations in our society that depend on human performance to avoid incidents involving significant adverse consequences. As our culture and technology have become more sophisticated, the management of risk on a broad basis has become more and more critical. The safe operation of military facilities, chemical plants, airlines, and mass transit, to name a few, are substantially dependent on the performance of the organizations that operate those facilities. The nuclear power industry has, within the past 15 years, increased the attention given to the influence of human performance in the safe operation of nuclear power plants (NPP). While NPPs have been designed through engineering disciplines to intercept and mitigate events that could cause adverse consequences, it has been clear from various safety-related incidents that human performance also plays a dominant role in preventing accidents. Initial efforts following the 1979 Three Mile Island incident focused primarily on ergonomic factors (e.g., the best design of control rooms for maximum performance). Greater attention was subsequently directed towards cognitive processes involved in the use of NPP decision support systems and decision making in general, personnel functions such as selection systems, and the influence of work scheduling and planning on employees' performance. Although each of these approaches has contributed to increasing the safety of NPPS, during the last few years, there has been a growing awareness that particular attention must be paid to how organizational processes affect NPP personnel performance, and thus, plant safety. The direct importance of organizational factors on safety performance in the NPP has been well-documented in the reports on the Three Mile Island and Chernobyl accidents as well as numerous other events, especially as evaluated by the U.S. Nuclear Regulatory Commission (NRC)

Safety review for human factors engineering and control rooms of nuclear power plants

International Nuclear Information System (INIS)

Yang Mengzhuo

1998-01-01

Safety review for human factors engineering and control rooms of nuclear power plants (NPP) is in a forward position of science and technology, which began at American TMI severe accident and had been implemented in China. The importance and the significance of the safety review are expounded, the requirements of its scope and profundity are explained in detail. In addition, the situation of the technical document system for nuclear safety regulation on human factors engineering and control rooms of NPP in China is introduced briefly, on which the safety review is based

A Study on the Allowable Safety Factor of Cut-Slopes for Nuclear Facilities

Energy Technology Data Exchange (ETDEWEB)

Kim, Myung Soo; Yee, Eric [KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

2015-10-15

In this study, the issues of allowable safety factor design criteria for cut-slopes in nuclear facilities is derived through case analysis, a proposed construction work slope design criteria that provides relatively detailed conditions can be applied in case of the dry season and some unclear parts of slope design criteria be modified in case of the rainy season. This safety factor can be further subdivided into two; normal and earthquake factors, a factor of 1.5 is applied for normal conditions and a factor of 1.2 is applied for seismic conditions. This safety factor takes into consideration the effect of ground water and rainfall conditions. However, no criteria for the case of cut-slope in nuclear facilities and its response to seismic conditions is clearly defined, this can cause uncertainty in design. Therefore, this paper investigates the allowable safety factor for cut-slopes in nuclear facilities, reviews conditions of both local and international cut-slope models and finally suggests an alternative method of analysis. It is expected that the new design criteria adequately ensures the stability of the cut-slope to reflect clear conditions for both the supervising and design engineers.

75 FR 5536 - Pipeline Safety: Control Room Management/Human Factors, Correction

Science.gov (United States)

2010-02-03

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Parts...: Control Room Management/Human Factors, Correction AGENCY: Pipeline and Hazardous Materials Safety... following correcting amendments: PART 192--TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM...

Development of safety factors to be used for evaluation of cracked nuclear components

International Nuclear Information System (INIS)

Brickstad, B.; Bergman, M.

1996-10-01

A modified concept for safety evaluation is introduced which separately accounts for the failure mechanisms fracture and plastic collapse. For application on nuclear components a set of safety factors are also proposed that retain the safety margins expressed in ASME, section III and XI. By performing comparative studies of the acceptance levels for surface cracks in pipes and a pressure vessel, it is shown that some of the anomalies connected with the old safety procedures are removed. It is the authors belief that the outlined safety evaluation procedure has the capability of treating cracks in a consistent way and that the procedure together with the proposed safety factors fulfill the basic safety requirements for nuclear components. Hopefully, it is possible in the near future to develop a probabilistic safety assessment procedure in Sweden, which enables a systematic treatment of uncertainties in the involved data. 14 refs

EDGE study in Russian Federation: efficacy and safety of vildagliptine in comparison with other oral antidiabetic agents in patients with type 2 diabetes mellitus

Directory of Open Access Journals (Sweden)

Gagik Radikovich Galstyan

2013-06-01

Full Text Available According to international consensus, metformin is acknowledged as a first-line therapeutic agent for type 2 diabetes mellitus (T2DM. However, in most cases this treatment eventually requires intensification by supplementation with other hypoglycemic medications. The aim of the EDGE study (Effective Diabetes control with vildaGliptin and vildagliptin/mEtformin was to assess the efficacy and safety of vildagliptin in comparison with other oral agents in routine management of patients with T2DM that has been poorly controlled by metformin monotherapy.

Requirements to amend the main influence factors on the safety culture after fukushima accident

International Nuclear Information System (INIS)

Farcasiu, M.; Nitoi, M.

2015-01-01

The paper presents a general model that provides a framework for the safety culture assessment, creating the possibility to identify factors that can significantly influence the safety culture. The main safety culture influence factors (SCIF) used by model are the following: regulatory environment, organizational environment, worker characteristics, socio-political environment, national culture, organization history, business and technological characteristics. After the analysis of the deficiencies and weaknesses of SCIFc in evolution of the Fukushima accident, some issues that may become necessities and requirements to change and improve both the safety culture and safety of the nuclear installations were highlighted. For each influence factor were identified some requirements to amend. The results will emphasize the necesity of the human - technology - organization system assessment. Hence it was demonstrated that the safety culture results from the interaction of individuals with technology and with the organization. (authors)

Research on review technology for three key safety factors of periodic safety review (PSR) and its application to Qinshan Nuclear Power Plant

International Nuclear Information System (INIS)

Xu Shoulv; Yao Weida; Dou Yikang; Lin Shaoxuan; Cao Yenan; Zhou Quanfu; Zheng Jiong; Zhang Ming

2009-04-01

In 2001, after 10 years' operation, Qinshan Nuclear Power Plant (Q1) started to carry out periodic safety review (PSR) based on a nuclear safety guideline, Periodic Safety Review for Operational Nuclear Power Plants (HAF0312), issued by National Nuclear Safety Administration of China (NNSA). Entrusted by the owner of Q1, Shanghai Nuclear Engineering Research and Design Institute (SNERDI) implemented reviews of three key safety factors including safety analysis, equipment qualification and ageing. PSR was a challenging work in China at that time and through three years' research and practice, SNERDI summarized a systematic achievement for the review including review methodology, scoping, review contents and implementation steps, etc.. During the process of review for the three safety factors, totally 148 review reports and 341 recommendations for corrections were submitted to Q1. These reports and recommendations have provided guidance for correction actions as follow-up of PSR. This paper focuses on technical aspects to carry out PSR for the above-mentioned three safety factors, including review scoping, contents, methodology and main steps. The review technology and relevant experience can be taken for reference for other NPPs to carry out PSR. (authors)

Modeling the factors affecting unsafe behavior in the construction industry from safety supervisors' perspective.

Science.gov (United States)

Khosravi, Yahya; Asilian-Mahabadi, Hassan; Hajizadeh, Ebrahim; Hassanzadeh-Rangi, Narmin; Bastani, Hamid; Khavanin, Ali; Mortazavi, Seyed Bagher

2014-01-01

There can be little doubt that the construction is the most hazardous industry in the worldwide. This study was designed to modeling the factors affecting unsafe behavior from the perspective of safety supervisors. The qualitative research was conducted to extract a conceptual model. A structural model was then developed based on a questionnaire survey (n=266) by two stage Structural Equation Model (SEM) approach. An excellent confirmed 12-factors structure explained about 62% of variances unsafe behavior in the construction industry. A good fit structural model indicated that safety climate factors were positively correlated with safety individual factors (Pconstruction workers' engagement in safe or unsafe behavior. In order to improve construction safety performance, more focus on the workplace condition is required.

Human and organization factors: engineering operating safety into offshore structures

International Nuclear Information System (INIS)

Bea, Robert G.

1998-01-01

History indicates clearly that the safety of offshore structures is determined primarily by the humans and organizations responsible for these structures during their design, construction, operation, maintenance, and decommissioning. If the safety of offshore structures is to be preserved and improved, then attention of engineers should focus on to how to improve the reliability of the offshore structure 'system,' including the people that come into contact with the structure during its life-cycle. This article reviews and discusss concepts and engineering approaches that can be used in such efforts. Two specific human factor issues are addressed: (1) real-time management of safety during operations, and (2) development of a Safety Management Assessment System to help improve the safety of offshore structures

Influence of organizational factors on safety

International Nuclear Information System (INIS)

Haber, S.B.; Metlay, D.S.; Crouch, D.A.

1990-01-01

There is a need for a better understanding of exactly how organizational management factors at a nuclear power plant (NPP) affect plant safety performance, either directly or indirectly, and how these factors might be observed, measured, and evaluated. The purpose of this research project is to respond to that need by developing a general methodology for characterizing these organizational and management factors, systematically collecting information on their status and integrating that information into various types of evaluative activities. Research to date has included the development of the Nuclear Organization and Management Analysis Concept (NOMAC) of a NPP, the identification of key organizational and management factors, and the identification of the methods for systematically measuring and analyzing the influence of these factors on performance. Most recently, two field studies, one at a fossil fuel plant and the other at a NPP, were conducted using the developed methodology. Results are presented from both studies highlighting the acceptability, practicality, and usefulness of the methods used to assess the influence of various organizational and management factors including culture, communication, decision-making, standardization, and oversight. 6 refs., 3 figs., 1 tab

The Relationship Between Antecedent and Consequence Factors with Safety Behaviour in PT.X

OpenAIRE

Fitriani, Apris; Nawawiwetu, Erwin Dyah

2017-01-01

Background : Safety behaviour is an act worker to minimize the possibility of accidents in workplace. Based on the Antecedents-Behaviour-Consequence (ABC) theory, safety behaviour of worker related with the antecedent and consequence factors. Purpose : The purpose of this research was to study the association between antecedent and consequence factors with safety behaviour of workers in Ring Frame Unit Spinning II PT. X. Methods : This was an observational descriptive research with cross sect...

A research framework of organizational factors on safety in the Republic of Korea

International Nuclear Information System (INIS)

Kwang Seok Lee

1997-01-01

Korean nuclear society is yet unfamiliar with the topic, 'organizational factors on safety', while having shown lots of accomplishments in the area of physical and human factors on safety. However, recent large-scale accidents in other technological areas illustrate the importance of managing organization factors on safety. Recently Korea Atomic Energy Research Institute (KAERI) started paying attention to this topic and is trying to establish a future research framework of organizational factors on safety. This paper tries to explain overall direction of the framework. Our framework, as managing organizational factors on safety, considers two kinds of areas: design of management systems, which implies a feed-forward system including organizational models; and operation of those systems, which implies a feedback system including management information and implementation systems. Our framework also considers the evolution stage of a management system. Management systems evolve from visibility stage to optimization stage. To optimize a management system, we should be able to control the system. To control the system, we should be able to see how the system is going. In addition, this paper tries to share some experience of KAERI on how organizational structure and culture affects organizational performance in R and D perspective. (author). 2 refs, 1 fig

Human and organizational factors in nuclear safety

International Nuclear Information System (INIS)

Garcia, A.; Barrientos, M.; Gil, B.

2015-01-01

Nuclear installations are socio technical systems where human and organizational factors, in both utilities and regulators, have a significant impact on safety. Three Mile Island (TMI) accident, original of several initiatives in the human factors field, nevertheless became a lost opportunity to timely acquire lessons related to the upper tiers of the system. Nowadays, Spanish nuclear installations have integrated in their processes specialists and activities in human and organizational factors, promoted by the licensees After many years of hard work, Spanish installations have achieved a better position to face new challenges, such as those posed by Fukushima. With this experience, only technology-centered action plan would not be acceptable, turning this accident in yet another lost opportunity. (Author)

Organisational factors. Their definition and influence on nuclear safety. Final report

International Nuclear Information System (INIS)

Baumont, G.; Wahlstroem, B.; Sola, R.; Williams, J.; Frischknecht, A.; Wilpert, B.; Rollenhagen, C.

2000-12-01

The importance of organisational factors in the operational safety and efficiency of nuclear power plants (NPP) has been recognised by many organisations around the world. Despite this recognition, however, there are as yet very few methods by which organisational factors can be systematically assessed and improved. The majority of research efforts applied so far have tended to be modest and scattered. The ORFA project was created as a remedy to these problems. The objective of the project is to create a better understanding of how organisation and management factors influence nuclear safety. A key scientific objective of the project is to identify components of a theoretical framework, which would help in understanding the relationships between organisational factors and nuclear safety. Three work packages were planned. First, a review of literature listed out the identified factors and methods for assessing them. Then, a draft version of the present report was prepared to clarify the environment context and the main issues of the topics. This draft was discussed at the ORFA seminar in Madrid 21-22 October 1999. During the seminar views and comments were collected on preliminary results of the project. Finally, this information has been integrated in the present and other reports and will be used to give further guidance to the European Commission in the development of forthcoming research programmes in the field. The project has addressed nuclear safety taking a broad perspective, which reflected and took into account the views of senior NPP management and regulators. The questions discussed during the project have been: how can organisational factors be included in safety assessments, how can good and bad operational practices be identified, which methods can be used for detecting weak signals of deteriorating performance, how should incidents be analysed with respect to organisational factors to give the largest learning benefit, how can data on organisational

Organizational factors influencing improvements in safety

International Nuclear Information System (INIS)

Marcus, A.; Nichols, M.L.; Olson, J.; Osborn, R.; Thurber, J.

1991-01-01

Results of conceptual and empirical research conducted by this research team, and published in NUREG-CR 5437, suggested that processes of organizational problem solving and learning provide a promising area for understanding improvement in safety-related performance in nuclear power plants. In this paper the authors describe the way in which they have built upon that work and gone much further in empirically examining a range of potentially important organizational factors related to safety. The paper describes (1) overall trends in plant performance over time on the Nuclear Regulatory Commission performance indicators, (2) the major elements in the conceptual framework guiding the current work, which seeks among other things to explain those trends, (3) the specific variables used as measures of the central concepts, (4) the results to date of the quantitative empirical work and qualitative work in progress, and (5) conclusions from the research

Discussion on the Safety Factors of Slopes Recommended for Small Dams

Directory of Open Access Journals (Sweden)

Jan Vrubel

2017-01-01

Full Text Available The design and assessment of the slope stability of small embankment dams is usually not carried out using slope stability calculations but rather by the comparison of proposed or existing dam slopes with those recommended by technical standards or guidelines. Practical experience shows that in many cases the slopes of small dams are steeper than those recommended. However, most of such steeper slopes at existing dams do not exhibit any visible signs of instability, defects or sliding. For the dam owner and also for dam stability engineers, the safety of the slope, expressed e.g. via a factor of safety, is crucial. The aim of this study is to evaluate the safety margin provided by recommended slopes. The factor of safety was evaluated for several dam shape and layout variants via the shear strength reduction method using PLAXIS software. The study covers various dam geometries, dam core and shoulder positions and parameter values of utilised soils. Three load cases were considered: one with a steady state seepage condition and two with different reservoir water level drawdown velocities – standard and critical. As numerous older small dams lack a drainage system, variants with and without a toe drain were assessed. Calculated factors of safety were compared with required values specified by national standards and guidelines.

Suppression and excitation of MHD activity with an electrically polarized electrode at the TCABR tokamak plasma edge

International Nuclear Information System (INIS)

Nascimento, I.C.; Kuznetsov, Yu.K.; Guimaraes-Filho, Z.O.; Chamaa-Neto, I. El; Usuriaga, O.; Fonseca, A.M.M.; Galvao, R.M.O.; Caldas, I.L.; Severo, J.H.F.; Semenov, I.B.; Ribeiro, C.; Heller, M.V.P.; Bellintani, V.; Elizondo, J.I.; Sanada, E.

2007-01-01

Two reproducible regimes of tokamak operation, with excitation or suppression of MHD activity can be obtained using a voltage-biased electrode inside the edge of the TCABR tokamak. The experiment was carried out adjusting the tokamak parameters to obtain two types of discharges: with strong or weak MHD activity, without biasing in both cases. The plasma current was adjusted to cover a range of safety factor from 2.9 up to 3.5, so that when biasing was applied the magnetic island (3,1) could interact with the edge barrier. The application of biasing in subsequent discharges of each type resulted in excitation or suppression of the MHD activity. The results show that the dominant modes are m = 2, n = 1 and m = 3, n = 1 for excitation and partial suppression, respectively. In both regimes a strong decrease in the radial electric field is detected with destruction of the transport barrier and of the improved confinement caused by different mechanisms. The measurements include temporal behaviour of edge transport, turbulence, poloidal electric and magnetic fields, edge density, radial electric fields and radial profile of H α line intensity. The explanation of the excitation and suppression processes is discussed in the paper

Survival and development of reintroduced Cattleya intermedia plants related to abiotic factors and herbivory at the edge and in the interior of a forest fragment in South Brazil

Directory of Open Access Journals (Sweden)

Delio Endres Júnior

2018-06-01

Full Text Available ABSTRACT Biotic and abiotic factors, such as luminosity, temperature, air humidity, and herbivory, can affect the establishment of reintroduced plants in natural habitats. This study evaluated the effects of these factors on the survival and growth of Cattleya intermedia plants reintroduced into a forest fragment in South Brazil. Plants of C. intermedia were obtained from in vitro seed germination in asymbiotic culture. Eighty-eight plants were reintroduced at both the forest edge and forest interior. Plants with greater shoot heights and number of leaves and pseudobulbs suffered more damage from herbivores at the edge. There were no significant differences in morphometric parameters between damaged and non-damaged plants in the interior. Tenthecoris bicolor, Helionothrips errans, Ithomiola nepos, Molomea magna and Coleoptera larvae damaged C. intermedia. Luminosity was higher at the edge, while air humidity and temperature were the same in both environments. Herbivory associated with abiotic factors increased plant mortality in the interior, while abiotic factors were determinative of plant survival at the edge. Luminosity is important to the survival of reintroduced epiphytic orchids, and herbivory affects the success of reintroduction.

Identifying the Critical Factors Affecting Safety Program Performance for Construction Projects within Pakistan Construction Industry

Directory of Open Access Journals (Sweden)

Zubair Ahmed Memon

2013-04-01

Full Text Available Many studies have shown that the construction industry one of the most hazardous industries with its high rates of fatalities and injuries and high financial losses incurred through work related accident. To reduce or overcome the safety issues on construction sites, different safety programs are introduced by construction firms. A questionnaire survey study was conducted to highlight the influence of the Construction Safety Factors on safety program implementation. The input from the questionnaire survey was analyzed by using AIM (Average Index Method and rank correlation test was conducted between different groups of respondents to measure the association between different groups of respondent. The finding of this study highlighted that management support is the critical factor for implementing the safety program on projects. From statistical test, it is concluded that all respondent groups were strongly in the favor of management support factor as CSF (Critical Success Factor. The findings of this study were validated on selected case studies. Results of the case studies will help to know the effect of the factors on implementing safety programs during the execution stage.

A quantitative assessment of organizational factors affecting safety using system dynamics model

Energy Technology Data Exchange (ETDEWEB)

Yu, Jae Kook; Ahn, Nam Sung [Korea Electric Power Research Institute, Taejon (Korea, Republic of); Jae, Moo Sung [Hanyang Univ., Seoul (Korea, Republic of)

2004-02-01

The purpose of this study is to develop a system dynamics model for the assessment of the organizational and human factors in a nuclear power plant which contribute to nuclear safety. Previous studies can be classified into two major approaches. One is the engineering approach using tools such as ergonomics and Probability Safety Assessment (PSA). The other is the socio-psychology approach. Both have contributed to find organizational and human factors and to present guidelines to lessen human error in plants. However, since these approaches assume that the relationship among factors is independent they do not explain the interactions among the factors or variables in nuclear power plants. To overcome these restrictions, a system dynamics model, which can show cause and effect relationships among factors and quantify the organizational and human factors, has been developed. Handling variables such as the degree of leadership, the number of employees, and workload in each department, users can simulate various situations in nuclear power plant organization. Through simulation, users can get insights to improve safety in plants and to find managerial tools in both organizational and human factors.

A quantitative assessment of organizational factors affecting safety using system dynamics model

International Nuclear Information System (INIS)

Yu, Jae Kook; Ahn, Nam Sung; Jae, Moo Sung

2004-01-01

The purpose of this study is to develop a system dynamics model for the assessment of the organizational and human factors in a nuclear power plant which contribute to nuclear safety. Previous studies can be classified into two major approaches. One is the engineering approach using tools such as ergonomics and Probability Safety Assessment (PSA). The other is the socio-psychology approach. Both have contributed to find organizational and human factors and to present guidelines to lessen human error in plants. However, since these approaches assume that the relationship among factors is independent they do not explain the interactions among the factors or variables in nuclear power plants. To overcome these restrictions, a system dynamics model, which can show cause and effect relationships among factors and quantify the organizational and human factors, has been developed. Handling variables such as the degree of leadership, the number of employees, and workload in each department, users can simulate various situations in nuclear power plant organization. Through simulation, users can get insights to improve safety in plants and to find managerial tools in both organizational and human factors

SU-E-T-370: Measurement of Conical Cone Output Factors for the Varian Edge Linear Accelerator

International Nuclear Information System (INIS)

Li, H; Kim, J; Gordon, J; Chetty, I; Wang, S; Zhong, H; Wen, N

2014-01-01

Purpose: To quantify the impact of detector type, SSD/depth, and intermediate reference on conical cone output factor (OF) measurements for the Varian Edge linac. Methods: OF's for 4, 5, 7.5, 10, 12.5, 15, and 17.5 mm diameter cones relative to 10cmx10cm field were measured for the 6X FFF and 10X FFF energies, with jaws set to 5cmx5cm. Measurements were performed with an Edge diode (0.8mmx0.8mmx0.03mm WxLxT), stereotatic diode SFD, photon diode, CC01 and pinpoint chambers (2mm diameter for both). 95cm SSD/5cm depth were used in a water tank. For the measurement with diodes, OF's were cross-referred to CC13 ion chamber measurements with 3cmx3cm field, as recommended, to help mitigate the energy variation in diode response with field size. Results were compared to the representative data from Varian measured with Edge detector. With SFD, OF's at 98.5cm SSD/1.5cm depth and 90cm SSD/10cm depth were also measured. Results: OF's measured with the Edge detector matched within 1.3% (max diff) with the representative data from Varian. For the SFD, OF's matched within 1.3% for the 4, 5 and 17.5 mm cones and within 3.7% for the other cones. OF's with photon diode were within 1.3% except for the 4 and 5 mm cones where they were 8.1% and 3.7%, respectively. OF's for the CC01 and pinpoint chamber deviated up to 36% and 44%, respectively for the 4 mm cone. OF's after intermediate reference with 3cmx3cm field changed by 3.7% for SFD, 0.8% for photon diode, and 0.6% for Edge detector. OF's at 98.5cm SSD/1.5cm depth were 10.8% higher than that at 95cm SSD/5cm depth, and OF's at 90cm SSD/1.5cm depth were 7.5% lower. Conclusion: OF's measured with the Edge detector appear to be reliable. CC01 and pinpoint chambers do not appear suitable for measuring the small cone OF's. SSD/depth affects OF measurements significantly

Edge effect correction using ion beam figuring.

Science.gov (United States)

Yang, Bing; Xie, Xuhui; Li, Furen; Zhou, Lin

2017-11-10

The edge effect is regarded as one of the most difficult technical issues for fabricating large primary mirrors, as it can greatly reduce the key performance of the optical system. Ion beam figuring (IBF) has the advantage of no edge effect, so we can use it to remove high points on the edge and improve surface accuracy. The edge local correction method (ELCM) of IBF processes only the surface edge zone, and is very different from the current full caliber figuring method (FCFM). Therefore, it is necessary to study the ELCM of IBF. In this paper, the key factors of ELCM are analyzed, such as dwell time algorithm, edge data extension methods, and the outward dimension of the starting figuring point. At the same time, the distinctions between ELCM and FCFM are compared. Finally, a 142 mm diameter fused silica mirror is fabricated to verify the validity of the theoretical of ELCM. The experimental results indicate that the figuring precision and efficiency can be obviously improved by ELCM.

Key Factors Affecting Construction Safety Performance in Developing Countries: Evidence from Cambodia

Directory of Open Access Journals (Sweden)

Serdar Durdyev

2017-12-01

Full Text Available Although proper safety management in construction is of utmost importance; anecdotal evidence suggests that safety is not adequately considered in many developing countries. This paper considers the key variables affecting construction safety performance in Cambodia. Using an empirical questionnaire survey targeting local construction professionals, respondents were invited to rate the level of importance of 30 variables identified from the seminal literature. The data set was subjected to factor analysis. Correlations between the variables show that five key factors underlie the challenges facing the local industry; management and organisation, resources, site management, cosmetic and workforce. It is found that the forefront construction professionals (top management and government authorities should take more responsibilities for further improvements in safety performance on project sites. Findings and recommendations of this study may be useful to construction professional who are seeking ways to improve safety records in developing countries.

Nuclear safety and human factors: the French factory of expertise

International Nuclear Information System (INIS)

Rolina, G.

2009-01-01

The French regulation of the nuclear safety is based on the maintaining of a deep technical dialogue between the nuclear safety authority, the I.R.S.N. (Institute of radiation protection and nuclear safety) and the nuclear operators. This type of risk management is called 'french coking' by the Anglo-Saxons, followers of stricter regulatory approach, more readable by the civil society. This technical dialogue is not without quality, especially in the field of human and organizational factors where it allows to improve the know how situation that stays incomplete. (N.C.)

Safer electronic health records safety assurance factors for EHR resilience

CERN Document Server

Sittig, Dean F

2015-01-01

This important volume provide a one-stop resource on the SAFER Guides along with the guides themselves and information on their use, development, and evaluation. The Safety Assurance Factors for EHR Resilience (SAFER) guides, developed by the editors of this book, identify recommended practices to optimize the safety and safe use of electronic health records (EHRs). These guides are designed to help organizations self-assess the safety and effectiveness of their EHR implementations, identify specific areas of vulnerability, and change their cultures and practices to mitigate risks.This book pr

Workers’ Age and the Impact of Psychological Factors on the Perception of Safety at Construction Sites

Directory of Open Access Journals (Sweden)

Muhammad Dawood Idrees

2017-05-01

Full Text Available The safety of construction workers is always a major concern at construction sites as the construction industry is inherently dangerous with many factors influencing worker safety. Several studies concluded that psychological factors such as workload, organizational relationships, mental stress, job security, and job satisfaction have significant effects on workers’ safety. However, research on psychological factors that are characteristic of different age groups have been limited. The aim of this study was to examine the impact of psychological factors on the perception of worker safety for two different age groups. After an extensive literature review, different psychological factors were identified, and a hypothetical research model was developed based on psychological factors that could affect workers’ perception of safety. A survey instrument was developed, and data were collected from seven different construction sites in Pakistan. Structural equation modeling (SEM was employed to test the hypothetical model for both age groups. The results revealed that workload and job satisfaction are significantly dominant factors on workers’ perception of safety in older workers, whereas organizational relationships, mental stress, and job security are dominant factors for younger workers at construction sites.

The impact of edge gradients in the pressure, density, ion temperature, and electron temperature on edge-localized modes

International Nuclear Information System (INIS)

Kleva, Robert G.; Guzdar, Parvez N.

2011-01-01

The magnitude of the energy and particle fluxes in simulations of edge-localized modes (ELMs) is determined by the edge gradients in the pressure, density, ion temperature, and electron temperature. The total edge pressure gradient is the dominant influence on ELMs by far. An increase (decrease) of merely 2% in the pressure gradient results in an increase (decrease) of more than a factor of ten in the size of the ELM bursts. At a fixed pressure gradient, the size of the ELM bursts decreases as the density gradient increases, while the size of the bursts increases as the electron temperature gradient or, especially, the ion temperature gradient increases.

Silicon K-edge XANES spectra of silicate minerals

Science.gov (United States)

Li, Dien; Bancroft, G. M.; Fleet, M. E.; Feng, X. H.

1995-03-01

Silicon K-edge x-ray absorption near-edge structure (XANES) spectra of a selection of silicate and aluminosilicate minerals have been measured using synchrotron radiation (SR). The spectra are qualitatively interpreted based on MO calculation of the tetrahedral SiO{4/4-}cluster. The Si K-edge generally shifts to higher energy with increased polymerization of silicates by about 1.3 eV, but with considerable overlap for silicates of different polymerization types. The substitution of Al for Si shifts the Si K-edge to lower energy. The chemical shift of Si K-edge is also sensitive to cations in more distant atom shells; for example, the Si K-edge shifts to lower energy with the substitution of Al for Mg in octahedral sites. The shifts of the Si K-edge show weak correlation with average Si-O bond distance (dSi-O), Si-O bond valence (sSi-O) and distortion of SiO4 tetrahedra, due to the crystal structure complexity of silicate minerals and multiple factors effecting the x-ray absorption processes.

Edge diagnostics for tandem mirror machines

International Nuclear Information System (INIS)

Allen, S.L.

1984-01-01

The edge plasma in a tandem mirror machine shields the plasma core from cold neutral gas and impurities. A variety of diagnostics are used to measure the fueling, shielding, and confinement of the edge plasma in both the end plug and central cell regions. Fast ion gauges and residual gas analyzers measure the gas pressure and composition outside of the plasma. An array of Langmuir probes is used to measure the electron density and temperature. Extreme ultraviolet (euv) and visible spectroscopy are used to measure both the impurity and deuterium densities and to estimate the shielding factor for the core plasma. The linear geometry of a tandem mirror also allows direct measurements of the edge plasma by sampling the ions and electrons lost but the ends of the machine. Representative data obtained by these diagnostics during operation of the Tandem Mirror Experiment (TMX) and Tandem Mirror Experiment-Upgrade (TMX-U) experiments are presented. Diagnostics that are currently being developed to diagnose the edge plasma are also discussed

Impact of Geotechnical Factors on the Safety of Low Embankment Dams From the Perspective of Technical and Safety Supervision

Directory of Open Access Journals (Sweden)

Kasana Andrej

2015-03-01

Full Text Available Our research deals with a broad spectrum of problems concerning the variability of geotechnical factors and their influence on the safety of the biggest group of dam constructions in Slovakia, i.e., low earthfill dams. Its specific aim is the observation of their risk factors by using our experience and knowledge gained while working in the sector of technical and safety supervision. To achieve the aims of a research thesis, we analyzed 39 low earthfill dams. We performed observations and documented their conditions with the aim of clarifying the risk factors. After an analysis of the information materials that characterize dams and after a statistical analysis of the measurement results in situ, including measurements from technical and safety supervision databases, we performed an analysis by using mathematical modeling to evaluate the safety of the dam constructions. Out of the total number of 39 dam constructions, an analysis of the stability of the dam slopes was performed on 37 dams, and deformation problems were analyzed on 28 of the dams. Filtration problems were analyzed at 26 dams, and a complete evaluation of the intensity of filtration movements was performed on 19 of the constructions.

Relationships between road safety, safety measures and external factors : a scan of the literature in view of model development and topics for further research.

NARCIS (Netherlands)

Churchill, T. & Norden, Y. van

2010-01-01

The purpose of this literature scan is to examine where literature on the effect of external factors and road safety measures on road safety exists and where it is lacking. This scan will help us to decide which factors to include in a comprehensive road safety model as SWOV is working on, and at

Power deposition on misaligned edges in COMPASS

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R. Dejarnac

2017-08-01

Full Text Available If the decision is made not to apply a toroidal chamfer to tungsten monoblocks at ITER divertor vertical targets, exposed leading edges will arise as a result of assembly tolerances between adjacent plasma-facing components. Then, the advantage of glancing magnetic field angles for spreading plasma heat flux on top surfaces is lost at the misaligned edges with an interaction occurring at near normal incidence, which can drive melting for the expected inter-ELM heat fluxes. A dedicated experiment has been performed on the COMPASS tokamak to thoroughly study power deposition on misaligned edges using inner-wall limited discharges on a special graphite tile presenting gaps and leading edges directly viewed by a high resolution infra-red camera. The parallel power flux deducted from the unperturbed measurement far from the gap is fully consistent with the observed temperature increase at the leading edge, respecting the power balance. All the power flowing into the gap is deposited at the leading edge and no mitigation factor is required to explain the thermal response. Particle-in-cell simulations show that the ion Larmor smoothing effect is weak and that the power deposition on misaligned edges is well described by the optical approximation because of an electron dominated regime associated with non-ambipolar parallel current flow.

Development of a draft of human factors safety review procedures for the Korean Next Generation Reactor

International Nuclear Information System (INIS)

Lee, Jung Woon; Moon, B. S.; Park, J. C.; Lee, Y. H.; Oh, I. S.; Lee, H. C.

2000-02-01

In this study, a draft of Human Factors Engineering (HFE) Safety Review Procedures (SRP) was developed for the safety review of KNGR based on HFE Safety and Regulatory Requirements and Guidelines (SRRG). This draft includes acceptance criteria, review procedure, and evaluation findings for the areas of review including HFE program management, human factors analyses, human factors design, and HFE verification and validation, based on section 15.1 'human factors engineering design process' and 15.2 'control room human factors engineering' of KNGR specific safety requirements and chapter 15 'human factors engineering' of KNGR safety regulatory guides. For the effective review, human factors concerns or issues related to advanced HSI design that have been reported so far should be extensively examined. In this study, a total of 384 human factors issues related to the advanced HSI design were collected through our review of a total of 145 documents. A summary of each issue was described and the issues were identified by specific features of HSI design. These results were implemented into a database system

The role of engineering judgement, safety culture, and organizational factors in risk assessment

International Nuclear Information System (INIS)

Muzumdar, Ajit; Professor, Visiting

1996-01-01

This paper reviews the role of engineering judgement, safety culture, and organizational factors in risk assessment by examining the reasons for human-based error. The need for more emphasis on producing engineers with good engineering judgement is described. The progress in quantifying the role of safety culture and organizational factors in risk assessment studies is summarized

IRSN-ANCCLI partnership. Organizational and human factors in nuclear safety - April 2014

International Nuclear Information System (INIS)

Jeffroy, Francois; Garron, Joel; Mercel, Philippe; Compagnat, Gilles; Gaucher, Eric; Gaillard, Pierre; Fanchini, Henri; Jacquemont, Vincent

2013-06-01

The contributions (Power Point presentations) of this seminar first address the history of the taking into account of organizational and human factors until the Fukushima accident (history of their taking into account in nuclear safety expertise in France, history of the development of policy of organizational and human factors by an operator). The next contributions discuss the main issues regarding these factors after Fukushima: report by a work-group, work performed by the the Comite d'Orientation sur les Facteurs Sociaux, Organisationnels et Humains (Committee of orientation on social, organizational and human factors). The third session addresses the implication of stakeholders in expertise on these factors: analysis of organizational and human factors by a local information commission or by a CHSCT (committee of hygiene, safety and working conditions)

Patient and carer identified factors which contribute to safety incidents in primary care: a qualitative study.

Science.gov (United States)

Hernan, Andrea L; Giles, Sally J; Fuller, Jeffrey; Johnson, Julie K; Walker, Christine; Dunbar, James A

2015-09-01

Patients can have an important role in reducing harm in primary-care settings. Learning from patient experience and feedback could improve patient safety. Evidence that captures patients' views of the various contributory factors to creating safe primary care is largely absent. The aim of this study was to address this evidence gap. Four focus groups and eight semistructured interviews were conducted with 34 patients and carers from south-east Australia. Participants were asked to describe their experiences of primary care. Audio recordings were transcribed verbatim and specific factors that contribute to safety incidents were identified in the analysis using the Yorkshire Contributory Factors Framework (YCFF). Other factors emerging from the data were also ascertained and added to the analytical framework. Thirteen factors that contribute to safety incidents in primary care were ascertained. Five unique factors for the primary-care setting were discovered in conjunction with eight factors present in the YCFF from hospital settings. The five unique primary care contributing factors to safety incidents represented a range of levels within the primary-care system from local working conditions to the upstream organisational level and the external policy context. The 13 factors included communication, access, patient factors, external policy context, dignity and respect, primary-secondary interface, continuity of care, task performance, task characteristics, time in the consultation, safety culture, team factors and the physical environment. Patient and carer feedback of this type could help primary-care professionals better understand and identify potential safety concerns and make appropriate service improvements. The comprehensive range of factors identified provides the groundwork for developing tools that systematically capture the multiple contributory factors to patient safety. Published by the BMJ Publishing Group Limited. For permission to use (where not

Impact of demographic factors on employees perceptions on health and safety management in the Greek Ministries

Directory of Open Access Journals (Sweden)

Pavlopoulou Georgia

2016-10-01

Full Text Available The purpose of the present study was to investigate the impact of selected demographic factors on perceptions of office workers regarding the management of health and safety in the office work place. For the data collection it was used a scale validated with a sample of 155 office employees. The final sample of the study was 301 subjects from three large Ministries in the Athens region of Greece, selected randomly. Exploratory factor analysis revealed four factors. A further comparison of the health and safety scale factors toward gender, marital status, working hours, monitoring or not seminars related to workplace safety and involvement or not in accidents in the office revealed that: (a The male employees had more positive perceptions than their female counterparts (t = 2.62, p <0.010. (b Positive perceptions showed and those who had attended seminars on safety and those who were not involved in office accidents (t = 2.16, p <0.032 and t = -2.19, p <0.033, respectively. (c It was also founded that men had more positive perceptions than women in the factor workplace environmental conditions (t = 2.40, p <0.018, while employees who had attended seminars on safety had a higher score on the factor health and safety issues in the office in comparison with their colleagues who did not, (t = 2.17, p <0.031. (d Employees who were involved in office accidents rated higher the questions of the factor health and safety issues in the office (t = -2.52, p <0. 015 and lower the factor workplace environmental conditions (t = -2.07, p = .043. It is concluded that despite the differences in the rating health and safety scale, in relation to selected variables, perceptions of employees regarding the management health and safety in the office work are positive.

Statistical Hot Channel Factors and Safety Limit CHFR/OFIR

Energy Technology Data Exchange (ETDEWEB)

Lee, Byeonghee; Park, Suki [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

The fuel integrity of research reactors are usually judged by comparing the critical heat flux ratio (CHFR) and the maximum fuel temperature (MFT) with the safety limits. Onset of flow instability ratio (OFIR) can also be used for the examination with CHFR. Hot channel factors (HCFs) are incorporated when calculating the CHFR/OFIR and MFT, to consider the uncertainties of fuel properties and thermo-hydraulic variables affecting them. The HCFs and safety limit CHFR is sometimes estimated to include too much conservatism, deteriorating the design flexibilities and operating margins. In this paper, a statistical estimation of HCFs and the safety limit CHFR/OFIR is presented by a random sampling of uncertainty parameters. A 15MW pool type research reactor is selected as the sample reactor for the estimation. The HCFs and the safety limit CHFR/OFIR of a 15MW pool type research reactor are evaluated statistically. The parameters affecting the HCF and the safety limit CHFR/OFIR are listed and their uncertainties are estimated. The relevant parameter uncertainties are sampled randomly and the HCFs and the safety limits are evaluated from them. The HCFs and the safety limit CHFR/OFIR with 95% probability are smaller than those estimated deterministically because the statistical evaluation convolute the correlation uncertainties and the other uncertainties in probabilistic way, whereas the deterministic evaluation simply multiply them.

Patient Safety Culture Survey in Pediatric Complex Care Settings: A Factor Analysis.

Science.gov (United States)

Hessels, Amanda J; Murray, Meghan; Cohen, Bevin; Larson, Elaine L

2017-04-19

Children with complex medical needs are increasing in number and demanding the services of pediatric long-term care facilities (pLTC), which require a focus on patient safety culture (PSC). However, no tool to measure PSC has been tested in this unique hybrid acute care-residential setting. The objective of this study was to evaluate the psychometric properties of the Nursing Home Survey on Patient Safety Culture tool slightly modified for use in the pLTC setting. Factor analyses were performed on data collected from 239 staff at 3 pLTC in 2012. Items were screened by principal axis factoring, and the original structure was tested using confirmatory factor analysis. Exploratory factor analysis was conducted to identify the best model fit for the pLTC data, and factor reliability was assessed by Cronbach alpha. The extracted, rotated factor solution suggested items in 4 (staffing, nonpunitive response to mistakes, communication openness, and organizational learning) of the original 12 dimensions may not be a good fit for this population. Nevertheless, in the pLTC setting, both the original and the modified factor solutions demonstrated similar reliabilities to the published consistencies of the survey when tested in adult nursing homes and the items factored nearly identically as theorized. This study demonstrates that the Nursing Home Survey on Patient Safety Culture with minimal modification may be an appropriate instrument to measure PSC in pLTC settings. Additional psychometric testing is recommended to further validate the use of this instrument in this setting, including examining the relationship to safety outcomes. Increased use will yield data for benchmarking purposes across these specialized settings to inform frontline workers and organizational leaders of areas of strength and opportunity for improvement.

Using partial safety factors in wind turbine design and testing

Energy Technology Data Exchange (ETDEWEB)

Musial, W.D. [National Renewable Energy Lab., Golden, CO (United States)

1997-12-31

This paper describes the relationship between wind turbine design and testing in terms of the certification process. An overview of the current status of international certification is given along with a description of limit-state design basics. Wind turbine rotor blades are used to illustrate the principles discussed. These concepts are related to both International Electrotechnical Commission and Germanischer Lloyd design standards, and are covered using schematic representations of statistical load and material strength distributions. Wherever possible, interpretations of the partial safety factors are given with descriptions of their intended meaning. Under some circumstances, the authors` interpretations may be subjective. Next, the test-load factors are described in concept and then related to the design factors. Using technical arguments, it is shown that some of the design factors for both load and materials must be used in the test loading, but some should not be used. In addition, some test factors not used in the design may be necessary for an accurate test of the design. The results show that if the design assumptions do not clearly state the effects and uncertainties that are covered by the design`s partial safety factors, outside parties such as test labs or certification agencies could impose their own meaning on these factors.

Prescribing safety, negotiating expertise. Building of nuclear safety human factors expertise

International Nuclear Information System (INIS)

Rolina, Gregory

2008-01-01

This Ph.D thesis is dedicated to a specific type of expertise, the safety of nuclear installations in the field of human and organisational factors. Empirical work is at the foundation of this thesis: the monitoring of experts 'in action', allowed a detailed reconstruction of three cases they were examining. The analysis, at the core of which lies the definition of what an efficient expertise can be, emphasizes the incompleteness of the knowledge that links together the nuclear facilities' organisational characteristics and their safety. This leads us to identify the expert's three ranges of actions (rhetorical, cognitive, operative). Defined from objectives and constraints likely to influence the expert's behaviour, those three ranges each require specific skills. A conception of expertise based on these ranges seems adaptable to other sectors and allows an enrichment of models of expertise cited in literature. Historical elements from French institutions of nuclear safety are also called upon to take into consideration some of the determinants of the expertise; its efficiency relies on the upholding of a continuous dialogue between the regulators (the experts and the control authority) and the regulated (the operators). This type of historically inherited regulation makes up a specificity of the French system of external control of nuclear risks. (author) [fr

Implication of human factors in terms of safety

International Nuclear Information System (INIS)

Furuta, Kazuo

2001-01-01

A critical accident of JCO occurred on September 30, 1999 gave a large impact not only to common society but also to nuclear energy field. This accident occurred by direct reason perfectly out of forecasting of the participants of nuclear energy, where a company made up a guideline violating from business allowance and safety rule and workmen also operated under a procedure out of the guideline. After the accident, a number of countermeasures on equipments, rules, and regulations were carried out, but discussion on software such as their operating methods, concrete regulation on business and authority of operators, and training of specialists seems to be much late. Safety is a problem on a complex system, containing not only hardware but also software such as human, organization, society, and so on. Then, here was discussed on a problem directly faced by conventional safety, engineering centering at hardware through thinking of a problem on human factors. (G.K.)

Method of calculating the safety factor profile on the HT-7 tokamak

International Nuclear Information System (INIS)

Zhang Xianmei; Lu Yuancheng; Wan Baonian

2001-01-01

A method of calculating the safety factor profile on the HT-7 tokamak has been described. It is derived from Maxwell's equations, among which the authors mainly use two of them: one is the magnetic field diffusion equation, and the other is Ampere's Law. This method can be also used to evaluate the safety factor on other devices with a circular cross sections. It is helpful to the study of the plasma MHD behavior on the HT-7 tokamak

Organizational safety factors research lessons learned

International Nuclear Information System (INIS)

Ryan, T.G.

1995-01-01

This Paper reports lessons learned and state of knowledge gained from an organizational factors research activity involving commercial nuclear power plants in the United States, through the end of 1991, as seen by the scientists immediately involved in the research. Lessons learned information was gathered from the research teams and individuals using a question and answer format. The following five questions were submitted to each team and individual: (1) What organizational factors appear to influence safety performance in some systematic way, (2) Should organizational factors research focus at the plant level, or should it extend beyond the plant level to the parent company, rate setting commissions, regulatory agencies, (3) How important is having direct access to plants for doing organizational factors research, (4) What lessons have been learned to date as the result of doing organizational factors research in a nuclear regulatory setting, and (5) What organizational research topics and issues should be pursued in the future? Conclusions based on the responses provided for this report are that organizational factors research can be conducted in a regulatory setting and produce useful results. Technologies pioneered in other academic, commercial, and military settings can be adopted for use in a nuclear regulatory setting. The future success of such research depends upon the cooperation of regulators, contractors, and the nuclear industry

Field demonstration of a portable, X-ray, K-edge heavy-metal detector

International Nuclear Information System (INIS)

Jensen, T.; Aljundi, T.; Whitmore, C.; Zhong, H.; Gray, J.N.

1997-01-01

Under the Characterization, Monitoring, and Sensor Technology Crosscutting Program, the authors have designed and built a K-edge heavy metal detector that measures the level of heavy metal contamination inside closed containers in a nondestructive, non-invasive way. The device employs a volumetric technique that takes advantage of the X-ray absorption characteristics of heavy elements, and is most suitable for characterization of contamination inside pipes, processing equipment, closed containers, and soil samples. The K-edge detector is a fast, efficient, and cost-effective in situ characterization tool. More importantly, this device will enhance personnel safety while characterizing radioactive and toxic waste. The prototype K-edge system was operated at the Materials and Chemistry Laboratory User Facility at the Oak Ridge K-25 Site during February 1997. Uranium contaminated pipes and valves from a UF 6 feed facility were inspected using the K-edge technique as well as a baseline nondestructive assay method. Operation of the K-edge detector was demonstrated for uranium contamination ranging from 10 to 6,000 mg/cm 2 and results from the K-edge measurements were found to agree very well with nondestructive assay measurements

Development of a draft of human factors safety review procedures for the Korean next generation reactor

Energy Technology Data Exchange (ETDEWEB)

Lee, Jung Woon; Moon, B. S.; Park, J. C.; Lee, Y. H.; Oh, I. S.; Lee, H. C. [Korea Atomic Energy Research Institute, Taejeon (Korea)

2000-02-01

In this study, a draft of human factors engineering (HFE) safety review procedures (SRP) was developed for the safety review of KNGR based on HFE Safety and Regulatory Requirements and Guidelines (SRRG). This draft includes acceptance criteria, review procedure, and evaluation findings for the areas of review including HFE Program Management, Human Factors Analyses, Human Factors Design, and HFE Verification and Validation, based on Section 15.1 'Human Factors Engineering Design Process' and 15.2 'Control Room Human Factors Engineering' of KNGR Specific Safety Requirements and Chapter 15 'Human Factors Engineering' of KNGR Safety Regulatory Guides. For the effective review, human factors concerns or issues related to advanced HSI design that have been reported so far should be extensively examined. In this study, a total of 384 human factors issues related to the advanced HSI design were collected through our review of a total of 145 documents. A summary of each issue was described and the issues were identified by specific features of HSI design. These results were implemented into a database system. 8 refs., 2 figs. (Author)

Safety update on the use of recombinant activated factor VII in approved indications.

Science.gov (United States)

Neufeld, Ellis J; Négrier, Claude; Arkhammar, Per; Benchikh el Fegoun, Soraya; Simonsen, Mette Duelund; Rosholm, Anders; Seremetis, Stephanie

2015-06-01

This updated safety review summarises the large body of safety data available on the use of recombinant activated factor VII (rFVIIa) in approved indications: haemophilia with inhibitors, congenital factor VII (FVII) deficiency, acquired haemophilia and Glanzmann's thrombasthenia. Accumulated data up to 31 December 2013 from clinical trials as well as post-marketing data (registries, literature reports and spontaneous reports) were included. Overall, rFVIIa has shown a consistently favourable safety profile, with no unexpected safety concerns, in all approved indications. No confirmed cases of neutralising antibodies against rFVIIa have been reported in patients with congenital haemophilia, acquired haemophilia or Glanzmann's thrombasthenia. The favourable safety profile of rFVIIa can be attributed to the recombinant nature of rFVIIa and its localised mechanism of action at the site of vascular injury. Recombinant FVIIa activates factor X directly on the surface of activated platelets, which are present only at the site of injury, meaning that systemic activation of coagulation is avoided and the risk of thrombotic events (TEs) thus reduced. Nonetheless, close monitoring for signs and symptoms of TE is warranted in all patients treated with any pro-haemostatic agent, including rFVIIa, especially the elderly and any other patients with concomitant conditions and/or predisposing risk factors to thrombosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

The human factors and the safety of experimentation reactors

International Nuclear Information System (INIS)

Jeffroy, F.; Delaporte-Normier, M.L.

2007-01-01

Inside IRSN (Institute for Radiological protection and Nuclear Safety), the mission of the Human Factors Group is to assess the way operators of nuclear installations take into account the risks related to human activities. In the last few years, IRSN has been involved in the safety analysis of different installations where Cea develops research programs, in particular experimental reactors. The first part of this article presents the methodology used by IRSN to evaluate how operators take into account risks related to human activities. This methodology is made up of 4 steps: 1) the identification of the human activities that convey a risk for the installation nuclear safety (safety-sensitive activities), for instance in the case of the Masurca reactor, it has been shown that errors made during the manufacturing of fuel tubes can lead to a criticality accident; 2) listing all the dispositions or arrangements taken to make human safety-sensitive activities more reliable; 3) checking the efficiency of such dispositions or arrangements; and 4) assessing the ability of the operators to generate the adequate dispositions or arrangements. The second part highlights the necessity to develop inside these research installations an organisation that facilitates cooperation between experimenters and operators

Application of factor analysis in psychological diagnostics (sample: study of students’ social safety

Directory of Open Access Journals (Sweden)

Pavel Aleksandrovich Kislyakov

2015-10-01

Our recommendations for the use of factor analysis, with necessary restrictions and clear reasons of a possible ambiguity of solutions, will be useful to everyone interested in mastering an adequate mathematical tool for solving problems pertaining to the humanities, in particular, those of practical psychology. As a practical example is presented the research of the psychological factors which provide students’ social safety. With the help of the factor analysis relevant personal and professional qualities of a teacher were revealed which are the subjective factors of students’ social safety, namely: social anticipation, socio-psychological stress resistance, social tolerance, professional orientation, responsibility, communication skills.

Verification of Overall Safety Factors In Deterministic Design Of Model Tested Breakwaters

DEFF Research Database (Denmark)

Burcharth, H. F.

2001-01-01

The paper deals with concepts of safety implementation in design. An overall safety factor concept is evaluated on the basis of a reliability analysis of a model tested rubble mound breakwater with monolithic super structure. Also discussed are design load identification and failure mode limit...

The balance between safety and productivity and its relationship with human factors and safety awareness and communication in aircraft manufacturing

NARCIS (Netherlands)

Karanikas, N.; Melis, Damien Jose; Kourousis, Kyriakos

2017-01-01

Background: This paper presents the findings of a pilot research survey which assessed the degree of balance between safety and productivity, and its relationship with awareness and communication of human factors and safety rules in the aircraft manufacturing environment. Methods: The study was

Identification of road user related risk factors, Deliverable 5.1 of the H2020 project SafetyCube (Safety CaUsation, Benefits and Efficiency).

NARCIS (Netherlands)

Filtness, A. & Papadimitriou, E. (Eds.) Leskovšek, B. Focant, N. Martensen, H. Sgarra, V. Usami, D.S. Soteropoulos, A. Stadlbauer, S. Theofilatos, A. Yannis, G. Ziakopoulos, A. Diamandouros, K. Durso, C. Goldenbeld, C. Loenis, B. Schermers, G. Petegem, J.-H. van Elvik, R. Hesjevoll, I.S. Quigley, C. & Papazikou, E.

2017-01-01

The present Deliverable (D5.1) describes the identification and evaluation of infrastructure related risk factors. It outlines the results of Task 5.1 of WP5 of SafetyCube, which aimed to identify and evaluate infrastructure related risk factors and related road safety problems by (i) presenting a

Partial safety factors for berthing velocity and loads on marine structures

NARCIS (Netherlands)

Roubos, A.A.; Peters, D.J.; Groenewegen, Leon; Steenbergen, R.

2018-01-01

Design methods for marine structures have evolved into load and resistance factor design, however existing partial safety factors related to berthing velocity and loads have not been verified and validated by measurement campaigns. In this study, field observations of modern seagoing vessels

The quiescent H-mode regime for high performance edge localized mode-stable operation in future burning plasmas

Energy Technology Data Exchange (ETDEWEB)

Garofalo, A. M., E-mail: garofalo@fusion.gat.com; Burrell, K. H.; Meneghini, O.; Osborne, T. H.; Paz-Soldan, C.; Smith, S. P.; Snyder, P. B.; Turnbull, A. D. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Eldon, D.; Grierson, B. A.; Solomon, W. M. [Princeton Plasma Physics Laboratory, P.O. Box 451, Princeton, New Jersey 08543-0451 (United States); Hanson, J. M. [Columbia University, 2960 Broadway, New York, New York 10027-6900 (United States); Holland, C. [University of California San Diego, 9500 Gilman Dr., La Jolla, California 92093-0417 (United States); Huijsmans, G. T. A.; Liu, F.; Loarte, A. [ITER Organization, Route de Vinon sur Verdon, 13067 St Paul Lez Durance (France); Zeng, L. [University of California Los Angeles, P.O. Box 957099, Los Angeles, California 90095-7099 (United States)

2015-05-15

For the first time, DIII-D experiments have achieved stationary quiescent H-mode (QH-mode) operation for many energy confinement times at simultaneous ITER-relevant values of beta, confinement, and safety factor, in an ITER-like shape. QH-mode provides excellent energy confinement, even at very low plasma rotation, while operating without edge localized modes (ELMs) and with strong impurity transport via the benign edge harmonic oscillation (EHO). By tailoring the plasma shape to improve the edge stability, the QH-mode operating space has also been extended to densities exceeding 80% of the Greenwald limit, overcoming the long-standing low-density limit of QH-mode operation. In the theory, the density range over which the plasma encounters the kink-peeling boundary widens as the plasma cross-section shaping is increased, thus increasing the QH-mode density threshold. The DIII-D results are in excellent agreement with these predictions, and nonlinear magnetohydrodynamic analysis of reconstructed QH-mode equilibria shows unstable low n kink-peeling modes growing to a saturated level, consistent with the theoretical picture of the EHO. Furthermore, high density operation in the QH-mode regime has opened a path to a new, previously predicted region of parameter space, named “Super H-mode” because it is characterized by very high pedestals that can be more than a factor of two above the peeling-ballooning stability limit for similar ELMing H-mode discharges at the same density.

Mechanical Safety Subcommittee Guideline for Design of Thin Windows Regarding Roark’s Edge Condition Coefficient

Energy Technology Data Exchange (ETDEWEB)

Ader, C. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Voirin, E. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); McGee, M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Nobrega, L. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

2017-06-15

An error was found in an edge stress coefficient used to calculate stresses in thin windows. This error is present in “Roark’s Formulas for Stress and Strain” 7th and 8th Edition. The 6th Edition is correct. This guideline specially discusses a major difference in regards to a coefficient used in calculating the edge stress in “Roark’s Formulas for Stress and Strain” 6th Edition compared to the 7th and 8th Editions. In Chapter 10: Flat Plates under “Circular plates under distributed load producing large deflections,” Case 3, which is “Fixed and held. Uniform pressure q over entire plate.” The coefficient for a fixed edge condition in the 6th Edition1 K4 = 0.476 while in the 7th and 8th Edition2, the coefficient is 1.73 which is significant difference.

Transaortic Alfieri Edge-to-Edge Repair for Functional Mitral Regurgitation.

Science.gov (United States)

Imasaka, Ken-Ichi; Tayama, Eiki; Morita, Shigeki; Toriya, Ryohei; Tomita, Yukihiro

2018-03-01

There is controversy about handling functional mitral regurgitation in patients undergoing aortic valve or proximal aortic operations. We describe a transaortic Alfieri edge-to-edge repair for functional mitral regurgitation that reduces operative excessive invasion and prolonged cardiopulmonary bypass time. Between May 2013 and December 2016, 10 patients underwent transaortic Alfieri edge-to-edge mitral repair. There were no operative deaths. The severity of mitral regurgitation immediately after the operation by transesophageal echocardiography was none or trivial in all patients. A transaortic Alfieri edge-to-edge repair for functional mitral regurgitation is a simple and safe approach. Copyright © 2018 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Insectivorous Birds and Environmental Factors Across an Edge-Interior Gradient in Tropical Rainforest of Malaysia

OpenAIRE

Abdullah B. Mohd; Mohamed Zakaria; Hossein Varasteh Moradi; Ebil Yusof

2009-01-01

The study objectives were to test: (1) the effects of the edge-interior gradient on understorey insectivorous bird abundance, density and diversity; (2) effects of environmental variables along an edge-interior gradient at population level (i.e., on each sub-guilds and species abundance); (3) possible effects of environmental structure along an edge-interior gradient at community level (i.e., species richness, diversity and total abundance). Fifteen hundred and four birds belonging to ...

Edge artifact correction for industrial computed tomography images

International Nuclear Information System (INIS)

Cai Yufang; Li Dan; Wang Jue

2013-01-01

To eliminate the edge artifacts of industrial CT images, and improve the identification ability of the image and the precision of the dimension measurement, a coefficient adjusting method for reducing crosstalk noise is proposed. It is concluded from theoretical analysis that crosstalk generated from adjacent detectors by Compton scattering is the major reason for the edge artifacts. According to the mathematic model of the detector crosstalk, we design a special detector system configuration and stair-step phantom for estimating the quantity of crosstalk noise. The relationship between crosstalk ratio and intensity of the incident X-ray is acquired by regressing experimental data with least square method. The experimental result shows that the first-order crosstalk ratio between detectors is about 9.0%, and the second-order crosstalk ratio is about 1.2%. Thus the first-order crosstalk is the main factor causing edge artifacts. The proposed method can reduce the edge artifacts significantly, and meanwhile maintain the detail and edge of CT images. (authors)

Edge-functionalization of armchair graphene nanoribbons with pentagonal-hexagonal edge structures.

Science.gov (United States)

Ryou, Junga; Park, Jinwoo; Kim, Gunn; Hong, Suklyun

2017-06-21

Using density functional theory calculations, we have studied the edge-functionalization of armchair graphene nanoribbons (AGNRs) with pentagonal-hexagonal edge structures. While the AGNRs with pentagonal-hexagonal edge structures (labeled (5,6)-AGNRs) are metallic, the edge-functionalized (5,6)-AGNRs with substitutional atoms opens a band gap. We find that the band structures of edge-functionalized (5,6)-N-AGNRs by substitution resemble those of defect-free (N-1)-AGNR at the Γ point, whereas those at the X point show the original ones of the defect-free N-AGNR. The overall electronic structures of edge-functionalized (5,6)-AGNRs depend on the number of electrons, supplied by substitutional atoms, at the edges of functionalized (5,6)-AGNRs.

Factors impacting perceived safety among staff working on mental health wards.

Science.gov (United States)

Haines, Alina; Brown, Andrew; McCabe, Rhiannah; Rogerson, Michelle; Whittington, Richard

2017-09-01

Safety at work is a core issue for mental health staff working on in-patient units. At present, there is a limited theoretical base regarding which factors may affect staff perceptions of safety. This study attempted to identify which factors affect perceived staff safety working on in-patient mental health wards. A cross-sectional design was employed across 101 forensic and non-forensic mental health wards, over seven National Health Service trusts nationally. Measures included an online staff survey, Ward Features Checklist and recorded incident data. Data were analysed using categorical principal components analysis and ordinal regression. Perceptions of staff safety were increased by ward brightness, higher number of patient beds, lower staff to patient ratios, less dayroom space and more urban views. The findings from this study do not represent common-sense assumptions. Results are discussed in the context of the literature and may have implications for current initiatives aimed at managing in-patient violence and aggression. None. © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY) license.

Feedback-assisted extension of the tokamak operating space to low safety factor

International Nuclear Information System (INIS)

Hanson, J. M.; Bialek, J. M.; Navratil, G. A.; Olofsson, K. E. J.; Shiraki, D.; Turco, F.; Baruzzo, M.; Bolzonella, T.; Marrelli, L.; Martin, P.; Piovesan, P.; Piron, C.; Piron, L.; Terranova, D.; Zanca, P.; Hyatt, A. W.; Jackson, G. L.; La Haye, R. J.; Lanctot, M. J.; Strait, E. J.

2014-01-01

Recent DIII-D and RFX-mod experiments have demonstrated stable tokamak operation at very low values of the edge safety factor q(a) near and below 2. The onset of n = 1 resistive wall mode (RWM) kink instabilities leads to a disruptive stability limit, encountered at q(a) = 2 (limiter plasmas) and q 95  = 2 (divertor plasmas). However, passively stable operation can be attained for q(a) and q 95 values as low as 2.2. RWM damping in the q(a) = 2 regime was measured using active MHD spectroscopy. Although consistent with theoretical predictions, the amplitude of the damped response does not increase significantly as the q(a) = 2 limit is approached, in contrast with damping measurements made approaching the pressure-driven RWM limit. Applying proportional gain magnetic feedback control of the n = 1 modes has resulted in stabilized operation with q 95 values reaching as low as 1.9 in DIII-D and q(a) reaching 1.55 in RFX-mod. In addition to being consistent with the q(a) = 2 external kink mode stability limit, the unstable modes have growth rates on the order of the characteristic wall eddy-current decay timescale in both devices, and a dominant m = 2 poloidal structure that is consistent with ideal MHD predictions. The experiments contribute to validating MHD stability theory and demonstrate that a key tokamak stability limit can be overcome with feedback

Feedback-Assisted Extension of the Tokamak Operating Space to Low Safety Factor

Science.gov (United States)

Hanson, J. M.

2013-10-01

Recent DIII-D experiments have demonstrated stable operation at very low edge safety factor, q95 instability. The performance of tokamak fusion devices may benefit from increased plasma current, and thus, decreased q. However, disruptive stability limits are commonly encountered in experiments at qedge ~ 2 (limited plasmas) and q95 ~ 2 (diverted plasmas), limiting exploration of low q regimes. In the recent DIII-D experiments, the impact and control of key disruptive instabilities was studied. Locked n = 1 modes with exponential growth times on the order of the wall eddy current decay timescale τw preceded disruptions at q95 = 2 . The instabilities have a poloidal structure that is consistent with VALEN simulations of the RWM mode structure at q95 = 2 . Applying proportional gain magnetic feedback control of the n = 1 mode resulted in stabilized operation with q95 reaching 1.9, and an extension of the discharge lifetime for > 100τw . Loss of feedback control was accompanied by power supply saturation, followed by a rapidly growing n = 1 mode and disruption. Comparisons of the feedback dynamics with VALEN simulations will be presented. The DIII-D results complement and will be discussed alongside recent RFX-MOD demonstrations of RWM control using magnetic feedback in limited tokamak discharges with qedge economical fusion power production. Supported by the US Department of Energy under DE-FG02-04ER54761 and DE-FC02-04ER54698.

Human Factors in Fire Safety Management and Prevention

Directory of Open Access Journals (Sweden)

M.A. Othuman Mydin

2014-07-01

Full Text Available Fire protection is the study and practice of mitigating the unwanted effects of potentially destructive fires. It involves the study of the behavior, compartmentalization, and investigation of fire and its related emergencies, as well as the research and development, production, testing and application of mitigating systems. Problems still occurred despite of the adequate fire safety systems installed. For most people in high-risk buildings, not all accidents were caused by them. They were more likely to be the victims of a fire that occurred. Besides damaging their properties and belongings, some people were burned to death for not knowing what to do if fire happens in their place. This paper will present the human factors in fire safety management and prevention system.

A Survey of Factors Affecting Blunt Leading-Edge Separation for Swept and Semi-Slender Wings

Science.gov (United States)

Luckring, James M.

2010-01-01

A survey is presented of factors affecting blunt leading-edge separation for swept and semi-slender wings. This class of separation often results in the onset and progression of separation-induced vortical flow over a slender or semi-slender wing. The term semi-slender is used to distinguish wings with moderate sweeps and aspect ratios from the more traditional highly-swept, low-aspect-ratio slender wing. Emphasis is divided between a selection of results obtained through literature survey a section of results from some recent research projects primarily being coordinated through NATO s Research and Technology Organization (RTO). An aircraft context to these studies is included.

Partial Safety Factors for Fatigue Design of Wind Turbine Blades

DEFF Research Database (Denmark)

Toft, Henrik Stensgaard; Sørensen, John Dalsgaard

2010-01-01

In the present paper calibration of partial safety factors for fatigue design of wind turbine blades is considered. The stochastic models for the physical uncertainties on the material properties are based on constant amplitude fatigue tests and the uncertainty on Miners rule for linear damage...... accumulation is determined from variable amplitude fatigue tests with the Wisper and Wisperx spectra. The statistical uncertainty for the assessment of the fatigue loads is also investigated. The partial safety factors are calibrated for design load case 1.2 in IEC 61400-1. The fatigue loads are determined...... from rainflow-counting of simulated time series for a 5MW reference wind turbine [1]. A possible influence of a complex stress state in the blade is not taken into account and only longitudinal stresses are considered....

Study on safety educations against individual causal factors of unsafe acts and specification of target trainees

International Nuclear Information System (INIS)

Hirose, Ayako; Takeda, Daisuke

2016-01-01

Many accidents and incidents are caused by unsafe acts. It is important to reduce these unsafe acts for preventing the accidents. The countermeasures for each causal factor behind unsafe acts are needed, however, comparing with improvement of facilities, workers-oriented measures such as safety educations are not sufficient. Then the purposes of this study are as follows: 1) to investigate the individual factors which have great impact of unsafe acts and the existing safety educations which aim to mitigate the impact of these factors, 2) to specify the target trainees to perform these safety educations. To identify common factors that affect unsafe act significantly, a web survey was conducted to 500 workers who have regularly carried out accident prediction training (i.e. Kiken-Yochi training). They were asked the situation which they were apt to act unsafely by free description. As the result, the following three main factors were extracted: impatience, overconfidence, and bothersome. Also, it was found that there were few existing safety educations which aim to mitigate the impact of these factors except for overconfidence. To specify the target trainees to perform safety educations which aim to mitigate the impact of these three factors, another web survey was conducted to 200 personnel in charge of safety at the workplace. They were asked the features of workers who tended to act unsafely by age group. The relationship between the factor that need to mitigate and the trainee who need to receive the education were clarified from the survey. (author)

Edge passivation induced single-edge ferromagnetism of zigzag MoS_2 nanoribbons

International Nuclear Information System (INIS)

Wang, Rui; Sun, Hui; Ma, Ben; Hu, Jingguo; Pan, Jing

2017-01-01

We performed density functional theory study on electronic structure, magnetic properties and stability of zigzag MoS_2 nanoribbons (ZMoS_2NRs) with and without oxygen (O) passivation. The bare ZMoS_2NRs are magnetic metal with ferromagnetic edge states, edge passivation decreases their magnetism because of the decrease of edge unsaturated electrons. Obviously, the electronic structure and magnetic properties of ZMoS_2NRs greatly depend on edge states. When both edges are passivated by O atoms, ZMoS_2NRs are nonmagnetic metals. When either edge is passivated by O atoms, the systems exhibit single-edge ferromagnetism and magnetism concentrates on the non-passivated edge. Edge passivation can not only tune the magnetism of ZMoS_2NRs, but also enhance their stability by eliminating dangling bonds. These interesting findings on ZMoS_2NRs may open the possibility of their application in nanodevices and spintronics. - Highlights: • Edge passivation for tuning magnetism of zigzag MoS_2 nanoribbons (ZMoS_2NRs) is proposed. • Edge passivation can tune ZMoS_2NRs from nonmagnetic metal to ferromagnetic metal. • When either edge is passivated, the systems exhibit single-edge ferromagnetic states. • These findings may inspire great interest in the community of ZMoS_2NRs and motivate numerous experimental researches.

A dispersion safety factor for LNG vapor clouds

Energy Technology Data Exchange (ETDEWEB)

Vílchez, Juan A. [TIPs – Trámites, Informes y Proyectos, SL, Llenguadoc 10, 08030 Barcelona (Spain); Villafañe, Diana [Centre d’Estudis del Risc Tecnològic (CERTEC), Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona, Catalonia (Spain); Casal, Joaquim, E-mail: joaquim.casal@upc.edu [Centre d’Estudis del Risc Tecnològic (CERTEC), Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona, Catalonia (Spain)

2013-02-15

Highlights: ► We proposed a new parameter: the dispersion safety factor (DSF). ► DSF is the ratio between the distance reached by the LFL and that reached by the visible cloud. ► The results for the DSF agree well with the evidence from large scale experiments. ► Two expressions have been proposed to calculate DSF as a function of H{sub R}. ► The DSF may help in indicating the danger of ignition of a LNG vapor cloud. -- Abstract: The growing importance of liquefied natural gas (LNG) to global energy demand has increased interest in the possible hazards associated with its storage and transportation. Concerning the event of an LNG spill, a study was performed on the relationship between the distance at which the lower flammability limit (LFL) concentration occurs and that corresponding to the visible contour of LNG vapor clouds. A parameter called the dispersion safety factor (DSF) has been defined as the ratio between these two lengths, and two expressions are proposed to estimate it. During an emergency, the DSF can be a helpful parameter to indicate the danger of cloud ignition and flash fire.

A dispersion safety factor for LNG vapor clouds

International Nuclear Information System (INIS)

Vílchez, Juan A.; Villafañe, Diana; Casal, Joaquim

2013-01-01

Highlights: ► We proposed a new parameter: the dispersion safety factor (DSF). ► DSF is the ratio between the distance reached by the LFL and that reached by the visible cloud. ► The results for the DSF agree well with the evidence from large scale experiments. ► Two expressions have been proposed to calculate DSF as a function of H R . ► The DSF may help in indicating the danger of ignition of a LNG vapor cloud. -- Abstract: The growing importance of liquefied natural gas (LNG) to global energy demand has increased interest in the possible hazards associated with its storage and transportation. Concerning the event of an LNG spill, a study was performed on the relationship between the distance at which the lower flammability limit (LFL) concentration occurs and that corresponding to the visible contour of LNG vapor clouds. A parameter called the dispersion safety factor (DSF) has been defined as the ratio between these two lengths, and two expressions are proposed to estimate it. During an emergency, the DSF can be a helpful parameter to indicate the danger of cloud ignition and flash fire

Factors affecting the utilization of safety devices by commercial ...

African Journals Online (AJOL)

Background: Motorcycle crashes are common causes of morbidity and mortality for both riders and passengers. To prevent and reduce the severity of injuries sustained through road traffic accidents (RTA) many countries enforce the use of safety devices while riding. Certain factors including non-enforcement of the existing ...

Analysis of Traffic Safety Factors at Level Rail-Road Crossings

Directory of Open Access Journals (Sweden)

Tomislav Mlinarić

2012-10-01

Full Text Available The paper analyses the main factors of traffic safety andreliabilityat level crossings. The number and causes of accidentsare stated, that result from ignorance, insufficient training ofthe traffic participants, their ilnsponsibility and insufficient orincomplete legislation, as well as from insufficiently professionaland scientifically not serious enough approach to solvingthis cardinal problem in road and railway traffic. Based on theanalysis the causes are determined and solutions proposed, aswell as more efficient methods to improve safety and reduce thenumber of traffic accidents at level crossings.

Measurement of Safety Factor Using Hall Probes on CASTOR Tokamak

Czech Academy of Sciences Publication Activity Database

Kovařík, Karel; Ďuran, Ivan; Bolshakova, I.; Holyaka, R.; Erashok, V.

2006-01-01

Roč. 56, suppl.B (2006), s. 104-110 ISSN 0011-4626. [Symposium on Plasma Physics and Technology/22nd./. Praha, 26.6.2006-29.6.2006] R&D Projects: GA AV ČR(CZ) KJB100430504 Institutional research plan: CEZ:AV0Z20430508 Keywords : Plasma * tokamak * safety factor * hall probe Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.568, year: 2006

On applying safety archetypes to the Fukushima accident to identify nonlinear influencing factors

Energy Technology Data Exchange (ETDEWEB)

Sousa, A.L., E-mail: alsousa@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Ribeiro, A.C.O., E-mail: antonio.ribeiro@bayer.com [Bayer Crop Science Brasil S.A., Belford Roxo, RJ (Brazil); Duarte, J.P., E-mail: julianapduarte@poli.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola Politecnica. Departamento de Engenharia Nuclear; Frutuoso e Melo, P.F., E-mail: frutuoso@nuclear.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COOPE/UFRJ), RJ (Brazil). Programa de Engenharia Nuclear

2013-07-01

Nuclear power plants are typically characterized as high reliable organizations. In other words, they are organizations defined as relatively error free over a long period of time. Another relevant characteristic of the nuclear industry is that safety efforts are credited to design. However, major accidents, like the Fukushima accident, have shown that new tools are needed to identify latent deficiencies and help improve their safety level. Safety archetypes proposed elsewhere (e. g., safety issues stalled in the face of technological advances and eroding safety) consonant with International Atomic Energy Agency (IAEA) efforts are used to examine different aspects of accidents in a systemic perspective of the interaction between individuals, technology and organizational factors. Safety archetypes can help consider nonlinear interactions. Effects are rarely proportional to causes and what happens locally in a system (near the current operating point) often does not apply to distant regions (other system states), so that one has to consider the so-called nonlinear interactions. This is the case, for instance, with human probability failure estimates and safety level identification. In this paper, we discuss the Fukushima accident in order to show how archetypes can highlight nonlinear interactions of factors that influenced it and how to maintain safety levels in order to prevent other accidents. The initial evaluation of the set of archetypes suggested in the literature showed that at least four of them are applicable to the Fukushima accident, as is inferred from official reports on the accident. These are: complacency (that is, the effects of complacency on safety), decreased safety awareness, fixing on symptoms and not the real causes and eroding safety. (author)

On applying safety archetypes to the Fukushima accident to identify nonlinear influencing factors

International Nuclear Information System (INIS)

Sousa, A.L.; Ribeiro, A.C.O.; Duarte, J.P.; Frutuoso e Melo, P.F.

2013-01-01

Nuclear power plants are typically characterized as high reliable organizations. In other words, they are organizations defined as relatively error free over a long period of time. Another relevant characteristic of the nuclear industry is that safety efforts are credited to design. However, major accidents, like the Fukushima accident, have shown that new tools are needed to identify latent deficiencies and help improve their safety level. Safety archetypes proposed elsewhere (e. g., safety issues stalled in the face of technological advances and eroding safety) consonant with International Atomic Energy Agency (IAEA) efforts are used to examine different aspects of accidents in a systemic perspective of the interaction between individuals, technology and organizational factors. Safety archetypes can help consider nonlinear interactions. Effects are rarely proportional to causes and what happens locally in a system (near the current operating point) often does not apply to distant regions (other system states), so that one has to consider the so-called nonlinear interactions. This is the case, for instance, with human probability failure estimates and safety level identification. In this paper, we discuss the Fukushima accident in order to show how archetypes can highlight nonlinear interactions of factors that influenced it and how to maintain safety levels in order to prevent other accidents. The initial evaluation of the set of archetypes suggested in the literature showed that at least four of them are applicable to the Fukushima accident, as is inferred from official reports on the accident. These are: complacency (that is, the effects of complacency on safety), decreased safety awareness, fixing on symptoms and not the real causes and eroding safety. (author)

Factors Affecting the Behavior of Engineering Students toward Safety Practices in the Machine Shop

Directory of Open Access Journals (Sweden)

Jessie Kristian M. Neria

2015-08-01

Full Text Available This study aimed to determine the factors that affect the behavior of engineering student toward safety practices in the machine shop. Descriptive type of research was utilized in the study. Results showed that most of the engineering students clearly understand the signage shown in the machine shop. Students are aware that they should not leave the machines unattended. Most of the engineering students handle and use the machine properly. The respondents have an average extent of safety practices in the machine shop which means that they are applying safety practices in their every activity in machine shop. There is strong relationship between the safety practices and the factors affecting behavior in terms of signage, reminder of teacher and rules and regulation.

Patient selection, echocardiographic screening and treatment strategies for interventional tricuspid repair using the edge-to-edge repair technique.

Science.gov (United States)

Hausleiter, Jörg; Braun, Daniel; Orban, Mathias; Latib, Azeem; Lurz, Philipp; Boekstegers, Peter; von Bardeleben, Ralph Stephan; Kowalski, Marek; Hahn, Rebecca T; Maisano, Francesco; Hagl, Christian; Massberg, Steffen; Nabauer, Michael

2018-04-24

Severe tricuspid regurgitation (TR) has long been neglected despite its well known association with mortality. While surgical mortality rates remain high in isolated tricuspid valve surgery, interventional TR repair is rapidly evolving as an alternative to cardiac surgery in selected patients at high surgical risk. Currently, interventional edge-to-edge repair is the most frequently applied technique for TR repair even though the device has not been developed for this particular indication. Due to the inherent differences in tricuspid and mitral valve anatomy and pathology, percutaneous repair of the tricuspid valve is challenging due to a variety of factors including the complexity and variability of tricuspid valve anatomy, echocardiographic visibility of the valve leaflets, and device steering to the tricuspid valve. Furthermore, it remains to be clarified which patients are suitable for a percutaneous tricuspid repair and which features predict a successful procedure. On the basis of the available experience, we describe criteria for patient selection including morphological valve features, a standardized process for echocardiographic screening, and a strategy for clip placement. These criteria will help to achieve standardization of valve assessment and the procedural approach, and to further develop interventional tricuspid valve repair using either currently available devices or dedicated tricuspid edge-to-edge repair devices in the future. In summary, this manuscript will provide guidance for patient selection and echocardiographic screening when considering edge-to-edge repair for severe TR.

The EPED pedestal model and edge localized mode-suppressed regimes: Studies of quiescent H-mode and development of a model for edge localized mode suppression via resonant magnetic perturbations

Energy Technology Data Exchange (ETDEWEB)

Snyder, P. B.; Osborne, T. H.; Burrell, K. H.; Groebner, R. J.; Leonard, A. W.; Wade, M. R. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Nazikian, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey (United States); Orlov, D. M. [University of California-San Diego, San Diego, California 92093 (United States); Schmitz, O. [Institut fuer Plasmaphysik, Forschungszentrum Juelich GmbH, Association FZJ-EURATOM, Juelich (Germany); Wilson, H. R. [York Plasma Institute, Department of Physics, University of York, Heslington, York YO10 5DD (United Kingdom)

2012-05-15

The EPED model predicts the H-mode pedestal height and width based upon two fundamental and calculable constraints: (1) onset of non-local peeling-ballooning modes at low to intermediate mode number, (2) onset of nearly local kinetic ballooning modes at high mode number. We present detailed tests of the EPED model in discharges with edge localized modes (ELMs), employing new high resolution measurements, and finding good quantitative agreement across a range of parameters. The EPED model is then applied for the first time to quiescent H-mode (QH), finding a similar level of agreement between predicted and observed pedestal height and width, and suggesting that the model can be used to predict the critical density for QH-mode operation. Finally, the model is applied toward understanding the suppression of ELMs with 3D resonant magnetic perturbations (RMP). Combining EPED with plasma response physics, a new working model for RMP ELM suppression is developed. We propose that ELMs are suppressed when a 'wall' associated with the RMP blocks the inward penetration of the edge transport barrier. A calculation of the required location of this 'wall' with EPED is consistent with observed profile changes during RMP ELM suppression and offers an explanation for the observed dependence on safety factor (q{sub 95}).

[Human factors and crisis resource management: improving patient safety].

Science.gov (United States)

Rall, M; Oberfrank, S

2013-10-01

A continuing high number of patients suffer harm from medical treatment. In 60-70% of the cases the sources of harm can be attributed to the field of human factors (HFs) and teamwork; nevertheless, those topics are still neither part of medical education nor of basic and advanced training even though it has been known for many years and it has meanwhile also been demonstrated for surgical specialties that training in human factors and teamwork considerably reduces surgical mortality.Besides the medical field, the concept of crisis resource management (CRM) has already proven its worth in many other industries by improving teamwork and reducing errors in the domain of human factors. One of the best ways to learn about CRM and HFs is realistic simulation team training with well-trained instructors in CRM and HF. The educational concept of the HOTT (hand over team training) courses for trauma room training offered by the DGU integrates these elements based on the current state of science. It is time to establish such training for all medical teams in emergency medicine and operative care. Accompanying safety measures, such as the development of a positive culture of safety in every department and the use of effective critical incident reporting systems (CIRs) should be pursued.

New theoretical investigation resolving discrepancies of atomic form factors and attenuation coefficients in the near-edge soft x-ray regime

International Nuclear Information System (INIS)

Chantler, C.T.

2000-01-01

Full text: Reliable knowledge of the complex X-ray form factor and the photoelectric attenuation coefficient is required for crystallography, medical diagnosis, refractive index studies and XAFS. Discrepancies between currently used theoretical approaches of 200% exist for numerous elements from 1 keV to 3 keV X-ray energies. This work derives new theoretical results in near-edge soft X-ray regions and improves upon the theoretical uncertainty in these regions by a factor of 10. This work was also reported in J.Phys.Chem.Ref.Data (2000)

Power spectrum weighted edge analysis for straight edge detection in images

Science.gov (United States)

Karvir, Hrishikesh V.; Skipper, Julie A.

2007-04-01

Most man-made objects provide characteristic straight line edges and, therefore, edge extraction is a commonly used target detection tool. However, noisy images often yield broken edges that lead to missed detections, and extraneous edges that may contribute to false target detections. We present a sliding-block approach for target detection using weighted power spectral analysis. In general, straight line edges appearing at a given frequency are represented as a peak in the Fourier domain at a radius corresponding to that frequency, and a direction corresponding to the orientation of the edges in the spatial domain. Knowing the edge width and spacing between the edges, a band-pass filter is designed to extract the Fourier peaks corresponding to the target edges and suppress image noise. These peaks are then detected by amplitude thresholding. The frequency band width and the subsequent spatial filter mask size are variable parameters to facilitate detection of target objects of different sizes under known imaging geometries. Many military objects, such as trucks, tanks and missile launchers, produce definite signatures with parallel lines and the algorithm proves to be ideal for detecting such objects. Moreover, shadow-casting objects generally provide sharp edges and are readily detected. The block operation procedure offers advantages of significant reduction in noise influence, improved edge detection, faster processing speed and versatility to detect diverse objects of different sizes in the image. With Scud missile launcher replicas as target objects, the method has been successfully tested on terrain board test images under different backgrounds, illumination and imaging geometries with cameras of differing spatial resolution and bit-depth.

Transaortic edge-to-edge mitral valve repair for moderate secondary/functional mitral regurgitation in patients undergoing aortic root/valve intervention.

Science.gov (United States)

Choudhary, Shiv Kumar; Abraham, Atul; Bhoje, Amol; Gharde, Parag; Sahu, Manoj; Talwar, Sachin; Airan, Balram

2017-11-01

The present study evaluates the feasibility, safety, and efficacy of edge-to-edge repair for moderate secondary/functional mitral regurgitation in patients undergoing aortic valve/root interventions. Sixteen patients underwent transaortic edge-to-edge mitral valve repair. Mitral regurgitation was 2+ in 8 patients and 3+ in 6 patients. Two patients in whom cardiac arrest developed preoperatively had severe (4+) mitral regurgitation. Patients underwent operation for severe aortic regurgitation ± aortic root lesions. The mean left ventricular systolic and diastolic diameters were 51.5 ± 12.8 mm and 70.7 ± 10.7 mm, respectively. Left ventricular ejection fraction ranged from 20% to 60%. Primary surgical procedure included Bentall's ± hemiarch replacement in 10 patients, aortic valve replacement in 5 patients, and noncoronary sinus replacement with aortic valve repair in 1 patient. Severity of mitral regurgitation decreased to trivial or zero in 13 patients, 1+ in 2 patients, and 2+ in 1 patient. There were no gradients across the mitral valve in 9 patients, less than 5 mm Hg in 6 patients, and 9 mm Hg in 1 patient. There was no operative mortality. Follow-up ranged from 2 weeks to 54 months. Echocardiography showed trivial or no mitral regurgitation in 12 patients, 1+ in 2 patients, and 2+ in 2 patients. None of the patients had significant mitral stenosis. The mean left ventricular systolic and diastolic diameters decreased to 40.5 ± 10.3 mm and 58.7 ± 11.6 mm, respectively. Ejection fraction also improved slightly (22%-65%). Transaortic edge-to-edge mitral valve repair is a safe and effective technique to abolish secondary/functional mitral regurgitation. However, its impact on overall survival needs to be studied. Copyright © 2017 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Outcome after percutaneous edge-to-edge mitral repair for functional and degenerative mitral regurgitation: a systematic review and meta-analysis.

Science.gov (United States)

Chiarito, Mauro; Pagnesi, Matteo; Martino, Enrico Antonio; Pighi, Michele; Scotti, Andrea; Biondi-Zoccai, Giuseppe; Latib, Azeem; Landoni, Giovanni; Mario, Carlo Di; Margonato, Alberto; Maisano, Francesco; Feldman, Ted; Alfieri, Ottavio; Colombo, Antonio; Godino, Cosmo

2018-02-01

Differences in terms of safety and efficacy of percutaneous edge-to-edge mitral repair between patients with functional and degenerative mitral regurgitation (MR) are not well established. We performed a systematic review and meta-analysis to clarify these differences. PubMed, EMBASE, Google scholar database and international meeting abstracts were searched for all studies about MitraClip. Studies with edge-to-edge repair in patients with functional versus degenerative MR were included in the meta-analysis (n=2615). At 1 year, there were not significant differences among groups in terms of patients with MR grade≤2 (719/1304 vs 295/504; 58% vs 54%; risk ratio (RR) 1.12; 95% CI: 0.86 to 1.47; p=0.40), while there was a significantly lower rate of mitral valve re-intervention in patients with functional MR compared with those with degenerative MR (77/1770 vs 80/818; 4% vs 10%; RR 0.60; 95% CI: 0.38 to 0.97; p=0.04). One-year mortality rate was 16% (408/2498) and similar among groups (RR 1.26; 95% CI: 0.90 to 1.77; p=0.18). Functional MR group showed significantly higher percentage of patients in New York Heart Association class III/IV (234/1480 vs 49/583; 16% vs 8%; pedge-to-edge repair is likely to be an efficacious and safe option in patients with both functional and degenerative MR. Large, randomised studies are ongoing and awaited to fully assess the clinical impact of the procedure in these two different MR aetiologies. © 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.

Hygrothermal effects on the tensile strength of carbon/epoxy laminates with molded edges

Directory of Open Access Journals (Sweden)

Cândido Geraldo Maurício

2000-01-01

Full Text Available The interlaminar stresses are confined to a region near the free edge. Therefore, the laminate stacking sequence and the free edge finishing are some of the factors that affect the strength of the laminate and limit its life. The use of molded edges eliminates the need for trimming and machining the laminates edges thus improving productivity. However, this fabrication technique may have a detrimental effect on the laminate strength for certain stacking sequences. This effect in the presence of moisture has not been characterized. This work presents the results of a comparative study of the resistance to delamination of laminates with machined edges and molded edges. Additionally, two environmental conditions were considered: dry laminates and laminates saturated with moisture. The tensile strength of the laminates were measured and micrographs were used to analyze the microstructure of the laminates near the free edges. It is concluded that the mechanical properties of advanced composites depend on the environmental conditions and the fabrication techniques used to produce the laminates. Therefore, it is necessary to account for these factors when experimentally determining the design allowables.

Planar slim-edge pixel sensors for the ATLAS upgrades

International Nuclear Information System (INIS)

Altenheiner, S; Goessling, C; Jentzsch, J; Klingenberg, R; Lapsien, T; Rummler, A; Troska, G; Wittig, T; Muenstermann, D

2012-01-01

The ATLAS detector at CERN is a general-purpose experiment at the Large Hadron Collider (LHC). The ATLAS Pixel Detector is the innermost tracking detector of ATLAS and requires a sufficient level of hermeticity to achieve superb track reconstruction performance. The current planar n-type pixel sensors feature a pixel matrix of n + -implantations which is (on the opposite p-side) surrounded by so-called guard rings to reduce the high voltage stepwise towards the cutting edge and an additional safety margin. Because of the inactive region around the active area, the sensor modules have been shingled on top of each other's edge which limits the thermal performance and adds complexity in the present detector. The first upgrade phase of the ATLAS pixel detector will consist of the insertable b-layer (IBL), an additional b-layer which will be inserted into the present detector in 2013. Several changes in the sensor design with respect to the existing detector had to be applied to comply with the IBL's specifications and are described in detail. A key issue for the ATLAS upgrades is a flat arrangement of the sensors. To maintain the required level of hermeticity in the detector, the inactive sensor edges have to be reduced to minimize the dead space between the adjacent detector modules. Unirradiated and irradiated sensors with the IBL design have been operated in test beams to study the efficiency performance in the sensor edge region and it was found that the inactive edge width could be reduced from 1100 μm to less than 250 μm.

Vehicle detection based on the use of shadow region and edge

Science.gov (United States)

Jeong, Sangheon; Kang, Seongkoo; Kim, Joongkyu

2013-07-01

Automotive and advanced driver assistance systems have attracted a great deal of attention lately. In these systems, effective and reliable vehicle detection is important because such systems can reduce the number of accidents and save human' lives. This paper describes an approach to detecting a forward vehicle using a camera mounted on the moving vehicle. In this paper, we describe two methods to detect a vehicle on the road. First, by using the vehicle's shadow, we can obtain the general location of the vehicular candidate. Second, we can identify the strong vertical edges at the left and right position of a vehicle. By combining the shadows and the edge, we can detect the vehicle's location. But other regions may also be detected, such as car windows, reflections, and illumination by the sun. In order to remove these other factors, defined as noises, we need to use a filter. After using the filter, we can calculate the exact location of the vehicle. Additionally, by using connected component labeling, we can obtain coordinates and establish the vehicle's location. Connected component labeling find all connected components in an image and assigns a unique label to all points in the same component. These methods are very useful for vehicle detection and the development of the driving assistance systems, and they can protect drivers' safety from having an accident.

Assessment of NPP safety taking into account seismic and engineering-geological factors

International Nuclear Information System (INIS)

Yakovlev, E.A.

1990-01-01

Consideration is given to the problem of probabilistic analysis of NPP safety with account of risk of destructive effect of earthquakes and the danger of accidental geological processes (diapirism, karst etc.) under NPP operation. It is shown that account of seismic and engineering-geological (engineering-seismological) risk factors in probabilistic analysis of safety enables to perform anticipatory analysis of behaviour of principle plant objects and to improve safety of their operation by revealing the most unstable elements of geotechnical system forming the main contribution to the total NPP risk

Research on Safety Factor of Dam Slope of High Embankment Dam under Seismic Condition

Directory of Open Access Journals (Sweden)

Li Bin

2015-01-01

Full Text Available With the constant development of construction technology of embankment dam, the constructed embankment dam becomes higher and higher, and the embankment dam with its height over 200m will always adopt the current design criteria of embankment dam only suitable for the construction of embankment dam lower than 200m in height. So the design criteria of high embankment dam shall be improved. We shall calculate the stability and safety factors of dam slope of high embankment dam under different dam height, slope ratio and different seismic intensity based on ratio of safety margin, and clarify the change rules of stability and safety factors of dam slope of high embankment dam with its height over 200m. We calculate the ratio of safety margin of traditional and reliable method by taking the stable, allowable and reliability index 4.2 of dam slope of high embankment dam with its height over 200m as the standard value, and conduct linear regression for both. As a result, the conditions, where 1.3 is considered as the stability and safety factors of dam slope of high embankment dam with its height over 200m under seismic condition and 4.2 as the allowable and reliability index, are under the same risk control level.

A Quantitative Feasibility Study on Potential Safety Improvement Effects of Advanced Safety Features in APR-1400 when Applied to OPR-1000

Energy Technology Data Exchange (ETDEWEB)

Ualikhan Zhiyenbayev [KAIST, Daejeon (Korea, Republic of); Chung, Dae Wook [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2015-10-15

This study aims to test the feasibility of the applications using Probabilistic Safety Assessment (PSA). Particularly, three of those advanced safety features are selected as follows: 1. Providing an additional Emergency Diesel Generator (EDG); 2. Increasing the capacity of Class 1E batteries; 3. Placing a Refueling Water Storage Tank (RWST) inside containment, i.e., change from RWST to IRWST. The Advanced Power Reactor 1400 (APR-1400) adopts several advanced safety features compared to its predecessor, the Optimized Power Reactor 1000 (OPR-1000), which includes an additional Emergency Diesel Generator, increase in battery capacity, in-containment refueling water storage tank (IRWST), and so on. Considering the remarkable advantages of these safety features in safety improvement and the design similarities between APR-1400 and OPR-1000, it is feasible to apply key advanced safety features of APR-1400 to OPR-1000 to enhance the safety. The selected safety features are incorporated into OPR-1000 PSA model using the Advanced Information Management System (AIMS) for PSA and CDFs are re-evaluated for each application and combination of three applications. Based on current results, it is concluded that three of key advanced safety features of APR-1400 can be effectively applied to OPR-1000, resulting in considerable safety improvement. In aggregate, three advanced safety features, which are an additional EDG, increased battery capacity and IRWST, can reduce the CDF of OPR-1000 by more than 15% when applied altogether.

A Quantitative Feasibility Study on Potential Safety Improvement Effects of Advanced Safety Features in APR-1400 when Applied to OPR-1000

International Nuclear Information System (INIS)

Ualikhan Zhiyenbayev; Chung, Dae Wook

2015-01-01

This study aims to test the feasibility of the applications using Probabilistic Safety Assessment (PSA). Particularly, three of those advanced safety features are selected as follows: 1. Providing an additional Emergency Diesel Generator (EDG); 2. Increasing the capacity of Class 1E batteries; 3. Placing a Refueling Water Storage Tank (RWST) inside containment, i.e., change from RWST to IRWST. The Advanced Power Reactor 1400 (APR-1400) adopts several advanced safety features compared to its predecessor, the Optimized Power Reactor 1000 (OPR-1000), which includes an additional Emergency Diesel Generator, increase in battery capacity, in-containment refueling water storage tank (IRWST), and so on. Considering the remarkable advantages of these safety features in safety improvement and the design similarities between APR-1400 and OPR-1000, it is feasible to apply key advanced safety features of APR-1400 to OPR-1000 to enhance the safety. The selected safety features are incorporated into OPR-1000 PSA model using the Advanced Information Management System (AIMS) for PSA and CDFs are re-evaluated for each application and combination of three applications. Based on current results, it is concluded that three of key advanced safety features of APR-1400 can be effectively applied to OPR-1000, resulting in considerable safety improvement. In aggregate, three advanced safety features, which are an additional EDG, increased battery capacity and IRWST, can reduce the CDF of OPR-1000 by more than 15% when applied altogether

Feedback-assisted extension of the tokamak operating space to low safety factor

Energy Technology Data Exchange (ETDEWEB)

Hanson, J. M., E-mail: jmh2130@columbia.edu; Bialek, J. M.; Navratil, G. A.; Olofsson, K. E. J.; Shiraki, D.; Turco, F. [Department of Applied Mathematics and Applied Physics, Columbia University, New York, New York 10027-6900 (United States); Baruzzo, M.; Bolzonella, T.; Marrelli, L.; Martin, P.; Piovesan, P.; Piron, C.; Piron, L.; Terranova, D.; Zanca, P. [Consorzio RFX, Corso Stati Uniti 4, 35127 Padova (Italy); Hyatt, A. W.; Jackson, G. L.; La Haye, R. J.; Lanctot, M. J.; Strait, E. J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); and others

2014-07-15

Recent DIII-D and RFX-mod experiments have demonstrated stable tokamak operation at very low values of the edge safety factor q(a) near and below 2. The onset of n = 1 resistive wall mode (RWM) kink instabilities leads to a disruptive stability limit, encountered at q(a) = 2 (limiter plasmas) and q{sub 95} = 2 (divertor plasmas). However, passively stable operation can be attained for q(a) and q{sub 95} values as low as 2.2. RWM damping in the q(a) = 2 regime was measured using active MHD spectroscopy. Although consistent with theoretical predictions, the amplitude of the damped response does not increase significantly as the q(a) = 2 limit is approached, in contrast with damping measurements made approaching the pressure-driven RWM limit. Applying proportional gain magnetic feedback control of the n = 1 modes has resulted in stabilized operation with q{sub 95} values reaching as low as 1.9 in DIII-D and q(a) reaching 1.55 in RFX-mod. In addition to being consistent with the q(a) = 2 external kink mode stability limit, the unstable modes have growth rates on the order of the characteristic wall eddy-current decay timescale in both devices, and a dominant m = 2 poloidal structure that is consistent with ideal MHD predictions. The experiments contribute to validating MHD stability theory and demonstrate that a key tokamak stability limit can be overcome with feedback.

A heuristic approach to edge detection in on-line portal imaging

International Nuclear Information System (INIS)

McGee, Kiaran P.; Schultheiss, Timothy E.; Martin, Eric E.

1995-01-01

Purpose: Portal field edge detection is an essential component of several postprocessing techniques used in on-line portal imaging, including field shape verification, selective contrast enhancement, and treatment setup error detection. Currently edge detection of successive fractions in a multifraction portal image series involves the repetitive application of the same algorithm. As the number of changes in the field is small compared to the total number of fractions, standard edge detection algorithms essentially recalculate the same field shape numerous times. A heuristic approach to portal edge detection has been developed that takes advantage of the relatively few changes in the portal field shape throughout a fractionation series. Methods and Materials: The routine applies a standard edge detection routine to calculate an initial field edge and saves the edge information. Subsequent fractions are processed by applying an edge detection operator over a small region about each point of the previously defined contour, to determine any shifts in the field shape in the new image. Failure of this edge check indicates that a significant change in the field edge has occurred, and the original edge detection routine is applied to the image. Otherwise the modified edge contour is used to define the new edge. Results: Two hundred and eighty-one portal images collected from an electronic portal imaging device were processed by the edge detection routine. The algorithm accurately calculated each portal field edge, as well as reducing processing time in subsequent fractions of an individual portal field by a factor of up to 14. Conclusions: The heuristic edge detection routine is an accurate and fast method for calculating portal field edges and determining field edge setup errors

Human factors evaluation of man-machine interface for periodic safety review of nuclear power plants

International Nuclear Information System (INIS)

Lee, Yong Hee; Lee, Jung Woon; Park, Jae Chang; Hwang, In Koo; Lee, Hyun Cheol; Jang, Tong Il; Ku, Jin Young; Kim, Soo Jin

2004-12-01

This report describes the research results of human factors assessment on the MMI(Man Machine Interface) equipment as part of Periodic Safety Review(PSR) of Nuclear Power Plants(NPPs). As MMI is a key factor among human factors to be reviewed in PSR, we reviewed the MMI components of nuclear power plants in aspect of human factors engineering. The availability, suitability, and effectiveness of the MMI devices were chosen to be reviewed. The MMI devices were investigated through the review of design documents related to the MMI, survey of control panels, evaluation of experts, and experimental assessment. Checklists were used to perform this assessment and record the review results. The items mentioned by the expert comments to review in detail in relation with task procedures were tested by experiments with operators' participation. For some questionable issues arisen during this MMI review, operator workload and possibility of errors in operator actions were analysed. The reviewed MMI devices contain MCR(Main Control Room), SPDS(Safety Parameter Display System), RSP(Remote Shutdown Panel), and the selected LCBs(Local Control Boards) importantly related to safety. As results of the assessments, any significant problem challenging the safety was not found on human factors in the MMI devices. However, several small items to be changed and improved in suitability of MMI devices were discovered. An action plan is recommended to accommodate the suggestions and review comments. It will enhance the plant safety on MMI area

Simplified probabilistic approach to determine safety factors in deterministic flaw acceptance criteria

International Nuclear Information System (INIS)

Barthelet, B.; Ardillon, E.

1997-01-01

The flaw acceptance rules in nuclear components rely on deterministic criteria supposed to ensure the safe operating of plants. The interest of having a reliable method of evaluating the safety margins and the integrity of components led Electricite de France to launch a study to link safety factors with requested reliability. A simplified analytical probabilistic approach is developed to analyse the failure risk in Fracture Mechanics. Assuming lognormal distributions of the main random variables, it is possible considering a simple Linear Elastic Fracture Mechanics model, to determine the failure probability as a function of mean values and logarithmic standard deviations. The 'design' failure point can be analytically calculated. Partial safety factors on the main variables (stress, crack size, material toughness) are obtained in relation with reliability target values. The approach is generalized to elastic plastic Fracture Mechanics (piping) by fitting J as a power law function of stress, crack size and yield strength. The simplified approach is validated by detailed probabilistic computations with PROBAN computer program. Assuming reasonable coefficients of variations (logarithmic standard deviations), the method helps to calibrate safety factors for different components taking into account reliability target values in normal, emergency and faulted conditions. Statistical data for the mechanical properties of the main basic materials complement the study. The work involves laboratory results and manufacture data. The results of this study are discussed within a working group of the French in service inspection code RSE-M. (authors)

Comparison of iodine K-edge subtraction and fluorescence subtraction imaging in an animal system

International Nuclear Information System (INIS)

Zhang, H.; Zhu, Y.; Bewer, B.; Zhang, L.; Korbas, M.; Pickering, I.J.; George, G.N.; Gupta, M.; Chapman, D.

2008-01-01

K-Edge Subtraction (KES) utilizes the discontinuity in the X-ray absorption across the absorption edge of the selected contrast element and creates an image of the projected density of the contrast element from two images acquired just above and below the K-edge of the contrast element. KES has proved to be powerful in coronary angiography, micro-angiography, bronchography, and lymphatic imaging. X-ray fluorescence imaging is a successful technique for the detection of dilute quantities of elements in specimens. However, its application at high X-ray energies (e.g. at the iodine K-edge) is complicated by significant Compton background, which may enter the energy window set for the contrast material's fluorescent X-rays. Inspired by KES, Fluorescence Subtraction Imaging (FSI) is a technique for high-energy (>20 keV) fluorescence imaging using two different incident beam energies just above and below the absorption edge of a contrast element (e.g. iodine). The below-edge image can be assumed as a 'background' image, which includes Compton scatter and fluorescence from other elements. The above-edge image will contain nearly identical spectral content as the below-edge image but will contain the additional fluorescence of the contrast element. This imaging method is especially promising with thick objects with dilute contrast materials, significant Compton background, and/or competing fluorescence lines from other materials. A quality factor is developed to facilitate the comparison. The theoretical value of the quality factor sets the upper limit that an imaging method can achieve when the noise is Poisson limited. The measured value of this factor makes two or more imaging methods comparable. Using the Hard X-ray Micro-Analysis (HXMA) beamline at the Canadian Light Source (CLS), the techniques of FSI and KES were critically compared, with reference to radiation dose, image acquisition time, resolution, signal-to-noise ratios, and quality factor

An improved computing method for the image edge detection

Institute of Scientific and Technical Information of China (English)

Gang Wang; Liang Xiao; Anzhi He

2007-01-01

The framework of detecting the image edge based on the sub-pixel multi-fractal measure (SPMM) is presented. The measure is defined, which gives the sub-pixel local distribution of the image gradient. The more precise singularity exponent of every pixel can be obtained by performing the SPMM analysis on the image. Using the singularity exponents and the multi-fractal spectrum of the image, the image can be segmented into a series of sets with different singularity exponents, thus the image edge can be detected automatically and easily. The simulation results show that the SPMM has higher quality factor in the image edge detection.

Super-resolved terahertz microscopy by knife-edge scan

Science.gov (United States)

Giliberti, V.; Flammini, M.; Ciano, C.; Pontecorvo, E.; Del Re, E.; Ortolani, M.

2017-08-01

We present a compact, all solid-state THz confocal microscope operating at 0.30 THz that achieves super-resolution by using the knife-edge scan approach. In the final reconstructed image, a lateral resolution of 60 μm ≍ λ/17 is demonstrated when the knife-edge is deep in the near-field of the sample surface. When the knife-edge is lifted up to λ/4 from the sample surface, a certain degree of super-resolution is maintained with a resolution of 0.4 mm, i.e. more than a factor 2 if compared to the diffraction-limited scheme. The present results open an interesting path towards super-resolved imaging with in-depth information that would be peculiar to THz microscopy systems.

Elastically Deformable Side-Edge Link for Trailing-Edge Flap Aeroacoustic Noise Reduction

Science.gov (United States)

Khorrami, Mehdi R. (Inventor); Lockard, David P. (Inventor); Moore, James B. (Inventor); Su, Ji (Inventor); Turner, Travis L. (Inventor); Lin, John C. (Inventor); Taminger, Karen M. (Inventor); Kahng, Seun K. (Inventor); Verden, Scott A. (Inventor)

2014-01-01

A system is provided for reducing aeroacoustic noise generated by an aircraft having wings equipped with trailing-edge flaps. The system includes a plurality of elastically deformable structures. Each structure is coupled to and along one of the side edges of one of the trailing-edge flaps, and is coupled to a portion of one of the wings that is adjacent to the one of the side edges. The structures elastically deform when the trailing-edge flaps are deployed away from the wings.

Localized Edge Vibrations and Edge Reconstruction by Joule Heating in Graphene Nanostructures

DEFF Research Database (Denmark)

Engelund, Mads; Fürst, Joachim Alexander; Jauho, Antti-Pekka

2010-01-01

Control of the edge topology of graphene nanostructures is critical to graphene-based electronics. A means of producing atomically smooth zigzag edges using electronic current has recently been demonstrated in experiments [Jia et al., Science 323, 1701 (2009)]. We develop a microscopic theory...... for current-induced edge reconstruction using density functional theory. Our calculations provide evidence for localized vibrations at edge interfaces involving unpassivated armchair edges. We demonstrate that these vibrations couple to the current, estimate their excitation by Joule heating, and argue...

The human factor in the organisation and regulation of nuclear safety

International Nuclear Information System (INIS)

Bordes, F.; Savagner, J.-M.; Snanoudj, G.

1981-10-01

The TMI accident has brought to light the importance of the human factor in the safe operation of complex installations such as nuclear power plants. On this basis, the paper outlines the institutional framework for nuclear safety in France and reports on EDF practices in human resources management as well as in the improvement of working premises (control rooms) to optimize human behaviour in accident conditions. Finally, the interaction of labour laws on nuclear law in connection with safety is described. (NEA) [fr

Reduction of airfoil trailing edge noise by trailing edge blowing

International Nuclear Information System (INIS)

Gerhard, T; Carolus, T; Erbslöh, S

2014-01-01

The paper deals with airfoil trailing edge noise and its reduction by trailing edge blowing. A Somers S834 airfoil section which originally was designed for small wind turbines is investigated. To mimic realistic Reynolds numbers the boundary layer is tripped on pressure and suction side. The chordwise position of the blowing slot is varied. The acoustic sources, i.e. the unsteady flow quantities in the turbulent boundary layer in the vicinity of the trailing edge, are quantified for the airfoil without and with trailing edge blowing by means of a large eddy simulation and complementary measurements. Eventually the far field airfoil noise is measured by a two-microphone filtering and correlation and a 40 microphone array technique. Both, LES-prediction and measurements showed that a suitable blowing jet on the airfoil suction side is able to reduce significantly the turbulence intensity and the induced surface pressure fluctuations in the trailing edge region. As a consequence, trailing edge noise associated with a spectral hump around 500 Hz could be reduced by 3 dB. For that a jet velocity of 50% of the free field velocity was sufficient. The most favourable slot position was at 90% chord length

Evaluation of design safety factors for time-dependent buckling

International Nuclear Information System (INIS)

Stone, C.M.; Nickell, R.E.

1977-02-01

The ASME Boiler and Pressure Vessel Code rules concerning time-dependent (creep) buckling for Class 1 nuclear components have recently been changed. Previous requirements for a factor of ten on service life have been replaced with a factor of safety of 1.5 on loading for load-controlled buckling. This report examines the supposed equivalence of the two rules from the standpoint of materials behavior--specifically, the secondary creep strain rate exponent. The comparison is made using results obtained numerically for an axially-loaded, cylindrical shell with varying secondary creep exponents. A computationally efficient scheme for analyzing creep buckling problems is also presented

Edge printability: techniques used to evaluate and improve extreme wafer edge printability

Science.gov (United States)

Roberts, Bill; Demmert, Cort; Jekauc, Igor; Tiffany, Jason P.

2004-05-01

The economics of semiconductor manufacturing have forced process engineers to develop techniques to increase wafer yield. Improvements in process controls and uniformities in all areas of the fab have reduced film thickness variations at the very edge of the wafer surface. This improved uniformity has provided the opportunity to consider decreasing edge exclusions, and now the outermost extents of the wafer must be considered in the yield model and expectations. These changes have increased the requirements on lithography to improve wafer edge printability in areas that previously were not even coated. This has taxed all software and hardware components used in defining the optical focal plane at the wafer edge. We have explored techniques to determine the capabilities of extreme wafer edge printability and the components of the systems that influence this printability. We will present current capabilities and new detection techniques and the influence that the individual hardware and software components have on edge printability. We will show effects of focus sensor designs, wafer layout, utilization of dummy edge fields, the use of non-zero overlay targets and chemical/optical edge bead optimization.

Assessing edge cracking resistance in AHSS automotive parts by the Essential Work of Fracture methodology

Science.gov (United States)

Frómeta, D.; Tedesco, M.; Calvo, J.; Lara, A.; Molas, S.; Casellas, D.

2017-09-01

Lightweight designs and demanding safety requirements in automotive industry are increasingly promoting the use of Advanced High Strength Steel (AHSS) sheets. Such steels present higher strength (above 800 MPa) but lower ductility than conventional steels. Their great properties allow the reduction of the thickness of automobile structural components without compromising the safety, but also introduce new challenges to parts manufacturers. The fabrication of most cold formed components starts from shear cut blanks and, due to the lower ductility of AHSS, edge cracking problems can appear during forming operations, forcing the stop of the production and slowing down the industrial process. Forming Limit Diagrams (FLD) and FEM simulations are very useful tools to predict fracture problems in zones with high localized strain, but they are not able to predict edge cracking. It has been observed that the fracture toughness, measured through the Essential Work of Fracture (EWF) methodology, is a good indicator of the stretch flangeability in AHSS and can help to foresee this type of fractures. In this work, a serial production automotive component has been studied. The component showed cracks in some flanged edges when using a dual phase steel. It is shown that the conventional approach to explain formability, based on tensile tests and FLD, fails in the prediction of edge cracking. A new approach, based on fracture mechanics, help to solve the problem by selecting steel grades with higher fracture toughness, measured by means of EWF. Results confirmed that fracture toughness, in terms of EWF, can be readily used as a material parameter to rationalize cracking related problems and select AHSS with improved edge cracking resistance.

Edge enhancement improves disruptive camouflage by emphasising false edges and creating pictorial relief.

Science.gov (United States)

Egan, John; Sharman, Rebecca J; Scott-Brown, Kenneth C; Lovell, Paul George

2016-12-06

Disruptive colouration is a visual camouflage composed of false edges and boundaries. Many disruptively camouflaged animals feature enhanced edges; light patches are surrounded by a lighter outline and/or a dark patches are surrounded by a darker outline. This camouflage is particularly common in amphibians, reptiles and lepidopterans. We explored the role that this pattern has in creating effective camouflage. In a visual search task utilising an ultra-large display area mimicking search tasks that might be found in nature, edge enhanced disruptive camouflage increases crypsis, even on substrates that do not provide an obvious visual match. Specifically, edge enhanced camouflage is effective on backgrounds both with and without shadows; i.e. this is not solely due to background matching of the dark edge enhancement element with the shadows. Furthermore, when the dark component of the edge enhancement is omitted the camouflage still provided better crypsis than control patterns without edge enhancement. This kind of edge enhancement improved camouflage on all background types. Lastly, we show that edge enhancement can create a perception of multiple surfaces. We conclude that edge enhancement increases the effectiveness of disruptive camouflage through mechanisms that may include the improved disruption of the object outline by implying pictorial relief.

Adjustment of Sentinel-2 Multi-Spectral Instrument (MSI Red-Edge Band Reflectance to Nadir BRDF Adjusted Reflectance (NBAR and Quantification of Red-Edge Band BRDF Effects

Directory of Open Access Journals (Sweden)

David P. Roy

2017-12-01

Full Text Available Optical wavelength satellite data have directional reflectance effects over non-Lambertian surfaces, described by the bidirectional reflectance distribution function (BRDF. The Sentinel-2 multi-spectral instrument (MSI acquires data over a 20.6° field of view that have been shown to have non-negligible BRDF effects in the visible, near-infrared, and short wave infrared bands. MSI red-edge BRDF effects have not been investigated. In this study, they are quantified by an examination of 6.6 million (January 2016 and 10.7 million (April 2016 pairs of forward and back scatter reflectance observations extracted over approximately 20° × 10° of southern Africa. Non-negligible MSI red-edge BRDF effects up to 0.08 (reflectance units across the 290 km wide MSI swath are documented. A recently published MODIS BRDF parameter c-factor approach to adjust MSI visible, near-infrared, and short wave infrared reflectance to nadir BRDF-adjusted reflectance (NBAR is adapted for application to the MSI red-edge bands. The red-edge band BRDF parameters needed to implement the algorithm are provided. The parameters are derived by a linear wavelength interpolation of fixed global MODIS red and NIR BRDF model parameters. The efficacy of the interpolation is investigated using POLDER red, red-edge, and NIR BRDF model parameters, and is shown to be appropriate for the c-factor NBAR generation approach. After adjustment to NBAR, red-edge MSI BRDF effects were reduced for the January data (acquired close to the solar principal where BRDF effects are maximal and the April data (acquired close to the orthogonal plane for all the MSI red-edge bands.

On the density of nearly regular graphs with a good edge-labelling

OpenAIRE

Mehrabian, Abbas

2011-01-01

A good edge-labelling of a simple graph is a labelling of its edges with real numbers such that, for any ordered pair of vertices (u,v), there is at most one nondecreasing path from u to v. Say a graph is good if it admits a good edge-labelling, and is bad otherwise. Our main result is that any good n-vertex graph whose maximum degree is within a constant factor of its average degree (in particular, any good regular graph) has at most n^{1+o(1)} edges. As a corollary, we show that there are b...

Proposal of criteria for evaluation of engineering safety factors of VVER core parameters

International Nuclear Information System (INIS)

Shishkov, L.; Tsyganov, S.; Dementiev, V.

2009-01-01

The paper states that the regulatory documentation, as a rule, do not give explicit recommendations on formation techniques of engineering safety factors for design limited parameters of normal operation (K eng ). The AER countries use different approaches to K eng evaluation (sometimes even one country in relation of various power units). The paper suggests the development of uniform rules to be used in calculation of engineering safety factor for all VVER reactors. The paper presents principal problems that must be solved in the course of the discussion, and in the form of an exercise suggests the way of their solution. (authors)

Proposal of criteria for evaluation of engineering safety factors of WWER core parameters

International Nuclear Information System (INIS)

Shishkov, L.; Tsyganov, S.; Dementiev, V.

2009-01-01

The paper states that the regulatory documentation, as a rule, do not give explicit recommendations on formation techniques of engineering safety factors for design limited parameters of normal operation. The AER countries use different approaches to evaluation (sometimes even one country in relation of various power units). The paper suggests the development of uniform rules to be used in calculation of engineering safety factor for all WWER reactors. The paper presents principal problems that must be solved in the course of the discussion, and in the form of an exercise suggests the way of their solution. (Authors)

Edge Matters

DEFF Research Database (Denmark)

Earon, Ofri

2013-01-01

of this container is to separate inside from outside and to protect and provide privacy, psychological as well as physical (Venturi, 1966). But, if dwelling phenomenon takes place both inside and outside the private house – why is the urban house an enclosed box? What is the differentiation between inside...... and outside the contemporary urban house? And what is the interplay between them? The research argues for re-thinking the edge zone between inside and outside the urban house. Therefore, although, residential buildings in the city are the objects of study, the focal point here is the edge zone along...... the building. The research explores and develops the architectural characteristics of correlations between the resident, the singular unit, the building and the given location at the edge zone. It approaches the edge zone of the urban house as a platform for dynamic interactions between these behaviours...

Optimization of edge state velocity in the integer quantum Hall regime

Science.gov (United States)

Sahasrabudhe, H.; Novakovic, B.; Nakamura, J.; Fallahi, S.; Povolotskyi, M.; Klimeck, G.; Rahman, R.; Manfra, M. J.

2018-02-01

Observation of interference in the quantum Hall regime may be hampered by a small edge state velocity due to finite phase coherence time. Therefore designing two quantum point contact (QPCs) interferometers having a high edge state velocity is desirable. Here we present a new simulation method for designing heterostructures with high edge state velocity by realistically modeling edge states near QPCs in the integer quantum Hall effect (IQHE) regime. Using this simulation method, we also predict the filling factor at the center of QPCs and their conductance at different gate voltages. The 3D Schrödinger equation is split into 1D and 2D parts. Quasi-1D Schrödinger and Poisson equations are solved self-consistently in the IQHE regime to obtain the potential profile, and quantum transport is used to solve for the edge state wave functions. The velocity of edge states is found to be /B , where is the expectation value of the electric field for the edge state. Anisotropically etched trench gated heterostructures with double-sided delta doping have the highest edge state velocity among the structures considered.

Application of the AHP method to analyze the significance of the factors affecting road traffic safety

Directory of Open Access Journals (Sweden)

Justyna SORDYL

2015-06-01

Full Text Available Over the past twenty years, the number of vehicles registered in Poland has grown rapidly. At the same time, a relatively small increase in the length of the road network has been observed. As a result of the limited capacity of available infrastructure, it leads to significant congestion and to increase of the probability of road accidents. The overall level of road safety depends on many factors - the behavior of road users, infrastructure solutions and the development of automotive technology. Thus the detailed assessment of the importance of individual elements determining road safety is difficult. The starting point is to organize the factors by grouping them into categories which are components of the DVE system (driver - vehicle - environment. In this work, to analyze the importance of individual factors affecting road safety, the use of analytic hierarchy process method (AHP was proposed. It is one of the multi-criteria methods which allows us to perform hierarchical analysis of the decision process, by means of experts’ opinions. Usage of AHP method enabled us to evaluate and rank the factors affecting road safety. This work attempts to link the statistical data and surveys in significance analysis of the elements determining road safety.

Grouping puts figure-ground assignment in context by constraining propagation of edge assignment.

Science.gov (United States)

Brooks, Joseph L; Brook, Joseph L; Driver, Jon

2010-05-01

Figure-ground organization involves the assignment of edges to a figural shape on one or the other side of each dividing edge. Established visual cues for edge assignment primarily concern relatively local rather than contextual factors. In the present article, we show that an assignment for a locally unbiased edge can be affected by an assignment of a remote contextual edge that has its own locally biased assignment. We find that such propagation of edge assignment from the biased remote context occurs only when the biased and unbiased edges are grouped. This new principle, whereby grouping constrains the propagation of figural edge assignment, emerges from both subjective reports and an objective short-term edge-matching task. It generalizes from moving displays involving grouping by common fate and collinearity, to static displays with grouping by similarity of edge-contrast polarity, or apparent occlusion. Our results identify a new contextual influence on edge assignment. They also identify a new mechanistic relation between grouping and figure-ground processes, whereby grouping between remote elements can constrain the propagation of edge assignment between those elements. Supplemental materials for this article may be downloaded from http://app.psychonomic-journals.org/content/supplemental.

Preparation of the requirements for the safety regulation related to human and organizational factors

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-08-15

The outline of the project in the current fiscal year is to investigate and analyze issues associated with Human and Organizational Factors involved in incidents of nuclear facilities, and to study and develop evaluation methods of these countermeasures. The guideline to evaluate licensee's safety culture and root cause analysis (RCA) had been developed for further improving safety on nuclear power plants at 2007. These guidelines have been used at regulatory inspection since that time. Based on experience of using these existing guidelines, some activities for improving guidelines are now under investigation; these are selecting candidate quantitative indicators for safety culture evaluation and researching good practices for RCA issues. JNES implemented human factor analysis about 18 domestic events including the Fukushima Dai-ichi nuclear power plant accident. (author)

Detailed new tabulation of atomic form factors and attenuation coefficients in the near-edge soft x-ray regime (Z = 30-36, Z = 60-89, E 0.1 keV - 8 keV), addressing convergence issues of earlier work

International Nuclear Information System (INIS)

Chantler, C.T.

1998-01-01

Reliable knowledge of the complex X-ray form factor (Re(f) and f ) and the photoelectric attenuation coefficient σ PE is required for crystallography, medical diagnosis, radiation safety and XAFS studies. Discrepancies between currently used theoretical approaches of 200% exist for numerous elements from 1 keV to 3 keV X-ray energies. The key discrepancies are due to the smoothing of edge structure, the use of non-relativistic wavefunctions, and the lack of appropriate convergence of wavefunctions. This paper addresses these key discrepancies and derives new theoretical results of substantially higher accuracy in near-edge soft X-ray regions. The high-energy limitations of the current approach are also illustrated. The associated figures and tabulation demonstrate the current comparison with alternate theory and with available experimental data. In general, experimental data is not sufficiently accurate to establish the errors and inadequacies of theory at this level. However, the best experimental data and the observed experimental structure as a function of energy are strong indicators of the validity of the current approach. New developments in experimental measurement hold great promise in making critical comparisons with theory in the near future. (authors)

Effects of Cutting Edge Microgeometry on Residual Stress in Orthogonal Cutting of Inconel 718 by FEM.

Science.gov (United States)

Shen, Qi; Liu, Zhanqiang; Hua, Yang; Zhao, Jinfu; Lv, Woyun; Mohsan, Aziz Ul Hassan

2018-06-14

Service performance of components such as fatigue life are dramatically influenced by the machined surface and subsurface residual stresses. This paper aims at achieving a better understanding of the influence of cutting edge microgeometry on machined surface residual stresses during orthogonal dry cutting of Inconel 718. Numerical and experimental investigations have been conducted in this research. The cutting edge microgeometry factors of average cutting edge radius S¯, form-factor K , and chamfer were investigated. An increasing trend for the magnitudes of both tensile and compressive residual stresses was observed by using larger S¯ or introducing a chamfer on the cutting edges. The ploughing depth has been predicted based on the stagnation zone. The increase of ploughing depth means that more material was ironed on the workpiece subsurface, which resulted in an increase in the compressive residual stress. The thermal loads were leading factors that affected the surface tensile residual stress. For the unsymmetrical honed cutting edge with K = 2, the friction between tool and workpiece and tensile residual stress tended to be high, while for the unsymmetrical honed cutting edge with K = 0.5, the high ploughing depth led to a higher compressive residual stress. This paper provides guidance for regulating machine-induced residual stress by edge preparation.

An edge pedestal model

International Nuclear Information System (INIS)

Stacev, W.M.

2001-01-01

A new model for calculation of the gradient scale lengths in the edge pedestal region and of the edge transport barrier width in H-mode tokamak plasmas will be described. Model problem calculations which demonstrate the promise of this model for predicting experimental pedestal properties will be discussed. The density and Prague gradient scale lengths (L) in the edge are calculated from the particle and ion and electron energy radial transport equations, making use of (presumed) known particle and energy fluxes flowing across the edge transport barrier from the core into the SOL and of edge transport coefficients. The average values of the particle and heat fluxes in the edge transport barrier are calculated in terms of the fluxes crossing into the SOL and the atomic physics reaction rates (ionisation, charge-exchange, elastic scattering, impurity radiation) in the edge by integrating the respective transport equations from the pedestal to the separatrix. An important implication of this model is that the pedestal gradient scale lengths depend not just on local pedestal platers properties but also on particle and energy fluxes from the core plasma and on recycling neutral fluxes that penetrate into the plasma edge, both of which in turn depend on the pedestal properties. The MHD edge pressure gradient constraint α≤ α C is used to determine the pressure width of the edge transport barrier, Δ TB = Δ TB (α c ). Three different models for the MHD edge pressure gradient constraint have been investigated: (1) nominal ideal ballooning mode theory, (2) ballooning mode theory taking into account the edge geometry and shear to access He second stability region; and pedestal β-limit theory when the ballooning modes are stabilised by diamagnetic effects. A series of calculations have been made for a DIII-D model problem. The calculated gradient scale lengths and edge transport barrier widths are of the magnitude of values observed experimentally, and certain trends

Edge-oriented dual-dictionary guided enrichment (EDGE) for MRI-CT image reconstruction.

Science.gov (United States)

Li, Liang; Wang, Bigong; Wang, Ge

2016-01-01

In this paper, we formulate the joint/simultaneous X-ray CT and MRI image reconstruction. In particular, a novel algorithm is proposed for MRI image reconstruction from highly under-sampled MRI data and CT images. It consists of two steps. First, a training dataset is generated from a series of well-registered MRI and CT images on the same patients. Then, an initial MRI image of a patient can be reconstructed via edge-oriented dual-dictionary guided enrichment (EDGE) based on the training dataset and a CT image of the patient. Second, an MRI image is reconstructed using the dictionary learning (DL) algorithm from highly under-sampled k-space data and the initial MRI image. Our algorithm can establish a one-to-one correspondence between the two imaging modalities, and obtain a good initial MRI estimation. Both noise-free and noisy simulation studies were performed to evaluate and validate the proposed algorithm. The results with different under-sampling factors show that the proposed algorithm performed significantly better than those reconstructed using the DL algorithm from MRI data alone.

75 FR 69912 - Pipeline Safety: Control Room Management/Human Factors

Science.gov (United States)

2010-11-16

... 192 and 195 [Docket ID PHMSA-2007-27954] RIN 2137-AE64 Pipeline Safety: Control Room Management/Human... Control Room Management/Human Factors rule at 49 CFR 192.631 and 195.446. The NPRM proposes to expedite... rule and to engage in open discussions with the agency at PHMSA's Control Room Management...

Comparison of edge plasma perturbation during ELM control using one vs. two toroidal rows of RMP coils in ITER similar shaped plasmas on DIII-D

Energy Technology Data Exchange (ETDEWEB)

Fenstermacher, M.E., E-mail: fenstermacher@fusion.gat.co [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States); Evans, T.E.; Osborne, T.H.; Schaffer, M.J.; DeGrassie, J.S.; Gohil, P.; Groebner, R.J. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Moyer, R.A. [University of California, San Diego, 9500 Gilman Dr., La Jolla, California 92093 (United States)

2009-06-15

Large Type-I edge localized modes (ELMs) were suppressed by n = 3 resonant magnetic perturbations (RMPs) from a set of internal coils in plasmas with an ITER similar shape at the ITER pedestal collisionality, nu{sub e}*approx0.1 and low edge safety factor (q{sub 95} approx 3.6), with either a single toroidal row of the internal RMP coils or two poloidally separated rows of coils. ELM suppression with a single row of internal coils was achieved at approximately the same q{sub 95} surface-averaged perturbation field as with two rows of coils, but required higher current per coil. Maintaining complete suppression of ELMs using n = 3 RMPs from a single toroidal row of internal coils was less robust to variations in input neutral beam injection torque than previous ELM suppression cases using both rows of internal coils. With either configuration of RMP coils, maximum ELM size is correlated with the width of the edge region having good overlap of the magnetic islands from vacuum field calculations.

Cultural factors influencing safety need to be addressed in design and operation of technology.

Science.gov (United States)

Meshkati, N

1996-10-01

Cultural factors which influence aviation safety in aircraft design, air traffic control, and human factors training are examined. Analysis of the Avianca Flight 052 crash in New York in January, 1990, demonstrates the catastrosphic effects cultural factors can play. Cultural factors include attitude toward work and technology, organizational hierarchy, religion, and population stereotyping.

Factors that impact on the safety of patient handovers: An interview study

DEFF Research Database (Denmark)

Siemsen, Inger Margrete; Madsen, Marlene Dyrløv; Pedersen, Lene Funck

2012-01-01

Aims: Improvement of clinical handover is fundamental to meet the challenges of patient safety. The primary aim of this interview study is to explore healthcare professionals’ attitudes and experiences with critical episodes in patient handover in order to elucidate factors that impact on handover...... from ambulance to hospitals and within and between hospitals. The secondary aim is to identify possible solutions to optimise handovers, defined as “situations where the professional responsibility for some or all aspects of a patient’s diagnosis, treatment or care is transferred to another person...... on patient safety in handover situations: communication, information, organisation, infrastructure, professionalism, responsibility, team awareness, and culture. Conclusions: The eight factors identified indicate that handovers are complex situations. The organisation did not see patient handover...

Risk factors for fishermen's health and safety in Greece

DEFF Research Database (Denmark)

Frantzeskou, Elpida; Kastania, Anastasia N; Riza, Elena

2012-01-01

Background: This is, to the best of our knowledge, the first occupational health study in Greek fishing. Aim: The aim of the study is to determine the risks for health and safety in Greek fisheries workers by exploring their health status and the health risk factors present in their occupational...... injury, of which half caused more than one day absence, while 14% had a near drowning experience. The health risks factors studied include excessive weight, cardiovascular incidents and dermatological, musculoskeletal, respiratory, hearing, stress, and anxiety problems. The occupational health risk...... factors include alcohol, fatty food consumption, smoking, and lack of physical exercise. Conclusions: The health effects observed are causally related to diet, smoking, and exercise, which in turn relate to the specific working conditions and culture in small-scale fishing that need to be taken...

Hazard Management Dealt by Safety Professionals in Colleges: The Impact of Individual Factors

Directory of Open Access Journals (Sweden)

Tsung-Chih Wu

2016-12-01

Full Text Available Identifying, evaluating, and controlling workplace hazards are important functions of safety professionals (SPs. The purpose of this study was to investigate the content and frequency of hazard management dealt by safety professionals in colleges. The authors also explored the effects of organizational factors/individual factors on SPs’ perception of frequency of hazard management. The researchers conducted survey research to achieve the objective of this study. The researchers mailed questionnaires to 200 SPs in colleges after simple random sampling, then received a total of 144 valid responses (response rate = 72%. Exploratory factor analysis indicated that the hazard management scale (HMS extracted five factors, including physical hazards, biological hazards, social and psychological hazards, ergonomic hazards, and chemical hazards. Moreover, the top 10 hazards that the survey results identified that safety professionals were most likely to deal with (in order of most to least frequent were: organic solvents, illumination, other chemicals, machinery and equipment, fire and explosion, electricity, noise, specific chemicals, human error, and lifting/carrying. Finally, the results of one-way multivariate analysis of variance (MANOVA indicated there were four individual factors that impacted the perceived frequency of hazard management which were of statistical and practical significance: job tenure in the college of employment, type of certification, gender, and overall job tenure. SPs within colleges and industries can now discuss plans revolving around these five areas instead of having to deal with all of the separate hazards.

Tangential 2-D Edge Imaging for GPI and Edge/Impurity Modeling

International Nuclear Information System (INIS)

Maqueda, Ricardo; Levinton, Fred M.

2011-01-01

Nova Photonics, Inc. has a collaborative effort at the National Spherical Torus Experiment (NSTX). This collaboration, based on fast imaging of visible phenomena, has provided key insights on edge turbulence, intermittency, and edge phenomena such as edge localized modes (ELMs) and multi-faceted axisymmetric radiation from the edge (MARFE). Studies have been performed in all these areas. The edge turbulence/intermittency studies make use of the Gas Puff Imaging diagnostic developed by the Principal Investigator (Ricardo Maqueda) together with colleagues from PPPL. This effort is part of the International Tokamak Physics Activity (ITPA) edge, scrape-off layer and divertor group joint activity (DSOL-15: Inter-machine comparison of blob characteristics). The edge turbulence/blob study has been extended from the current location near the midplane of the device to the lower divertor region of NSTX. The goal of this effort was to study turbulence born blobs in the vicinity of the X-point region and their circuit closure on divertor sheaths or high density regions in the divertor. In the area of ELMs and MARFEs we have studied and characterized the mode structure and evolution of the ELM types observed in NSTX, as well as the study of the observed interaction between MARFEs and ELMs. This interaction could have substantial implications for future devices where radiative divertor regions are required to maintain detachment from the divertor plasma facing components.

Transition over C4 leading edge and measurement of intermittency factor using PDF of hot-wire signal

Energy Technology Data Exchange (ETDEWEB)

Hazarika, B.K.; Hirsch, C. [Vrije Univ. Brussel, Brussels (Belgium). Dept. of Fluid Mechanics

1997-07-01

The variation of intermittency factors in the transition region of a C4 leading edge flat plate is measured at three incidence angles in a low-turbulence free stream. During the determination of intermittency factor, the threshold value of the detector function and the validity of conditional averaging are verified by a method based on the direct application of PDF of the hot-wire output. As the angle of incidence is increased, the transition progressively moves through all the three modes on the suction surface: at zero incidence the bypass transition, at 2 deg incidence the natural transition, and at 4 deg incidence the separated-flow transition occur, respectively. All three modes of transition exhibited the chordwise intermittency factor variation in accordance with Narasinha`s universal intermittency distribution; thus, the method based on spot production rate is applicable to all the three modes of transition. In the transition zone of the attached boundary layers, the conditionally averaged interturbulent profiles are fuller than the Blasius profile, while the conditionally averaged turbulent profiles follow a logarithmic profile with a variable additive parameter.

The Effects of Occupational Health and Safety Risk Factors on Job Satisfaction in Hotel Enterprises

OpenAIRE

Gonca Kilic; Murat Selim Selvi

2009-01-01

Occupational health and safety risk factors can have direct or indirect effects on levels of organizational commitment, job satisfaction, and the job productivity of workers in service companies as well as other types of industries. In this paper, the effects of physical, biological, chemical and socio-psychological risk factors, related to occupational safety and health, encountered in hotel enterprises on job satisfaction were investigated. Questionnaire survey was conducted as a data colle...

Missing focus on Human Factors - organizational and cognitive ergonomics - in the safety management for the petroleum industry.

Science.gov (United States)

Johnsen, Stig O; Kilskar, Stine Skaufel; Fossum, Knut Robert

2017-08-01

More attention has recently been given to Human Factors in petroleum accident investigations. The Human Factors areas examined in this article are organizational, cognitive and physical ergonomics. A key question to be explored is as follows: To what degree are the petroleum industry and safety authorities in Norway focusing on these Human Factors areas from the design phase? To investigate this, we conducted an innovative exploratory study of the development of four control centres in Norwegian oil and gas industry in collaboration between users, management and Human Factors experts. We also performed a literature survey and discussion with the professional Human Factors network in Norway. We investigated the Human Factors focus, reasons for not considering Human Factors and consequences of missing Human Factors in safety management. The results revealed an immature focus and organization of Human Factors. Expertise on organizational ergonomics and cognitive ergonomics are missing from companies and safety authorities and are poorly prioritized during the development. The easy observable part of Human Factors (i.e. physical ergonomics) is often in focus. Poor focus on Human Factors in the design process creates demanding conditions for human operators and impact safety and resilience. There is lack of non-technical skills such as communication and decision-making. New technical equipment such as Closed Circuit Television is implemented without appropriate use of Human Factors standards. Human Factors expertise should be involved as early as possible in the responsible organizations. Verification and validation of Human Factors should be improved and performed from the start, by certified Human Factors experts in collaboration with the workforce. The authorities should check-back that the regulatory framework of Human Factors is communicated, understood and followed.

Assessment of Factors Associated with the Safety Depth of GV15 Yamen

Directory of Open Access Journals (Sweden)

Park Soo-Jung

2014-03-01

Full Text Available Objectives: Yamen is the fifteenth acupoint of the Governor Vessel Meridian (GV15. It is anatomically close to the medulla oblongata, so finding the safety depth of the acupoint is very important. However, few studies on the safety depth of GV15 have been done. Methods: This study tried to measure the safety depth of GV15 by using magnetic resonance imaging (MRI scans and to analyze the factors affecting the safety depth through multiple regression analyses. This study was carried out for patients who had a brain MRI scan while visiting Jeonju Wonkwang Hospital, Korea. The shortest distance between the glabella and the occipital protuberance (DGO, the horizontal distance between the glabella and the back of the head (DGB and the dangerous depth (DD were measured from the sagittal views of the MRI images. The DD is the horizontal distance from the skin’s surface at GV15 to the spinal dura mater. Results: The model suggested that the safety depth (SD was significantly associated with gender (β = 0.474, P < 0.0001, DGO (β = 0.272, P = 0.027, and BMI (β = 0.249, P = 0.005 and the combination of three variables can explain the SD, with R2 = 0.571 (Table 3 A longer SD was associated with males and with greater BMI and DGO. Conclusion: This study suggests that gender, BMI and DGO may be important factors when the SD of GV15 is considered clinically through a multiple regression analysis of GV15.

Edge effects and geometric constraints: a landscape-level empirical test.

Science.gov (United States)

Ribeiro, Suzy E; Prevedello, Jayme A; Delciellos, Ana Cláudia; Vieira, Marcus Vinícius

2016-01-01

incorporation is necessary to properly interpret edge effects in landscapes. It also suggests that geometric constraints alone are unlikely to explain the variability in edge responses of a same species among different areas, highlighting the need to incorporate other ecological factors into explanatory models of edge effects. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Edge orientations of mechanically exfoliated anisotropic two-dimensional materials

Science.gov (United States)

Yang, Juntan; Wang, Yi; Li, Yinfeng; Gao, Huajian; Chai, Yang; Yao, Haimin

2018-03-01

Mechanical exfoliation is an approach widely applied to prepare high-quality two-dimensional (2D) materials for investigating their intrinsic physical properties. During mechanical exfoliation, in-plane cleavage results in new edges whose orientations play an important role in determining the properties of the as-exfoliated 2D materials especially those with high anisotropy. Here, we systematically investigate the factors affecting the edge orientation of 2D materials obtained by mechanical exfoliation. Our theoretical study manifests that the fractured direction during mechanical exfoliation is determined synergistically by the tearing direction and material anisotropy of fracture energy. For a specific 2D material, our theory enables us to predict the possible edge orientations of the exfoliated flakes as well as their occurring probabilities. The theoretical prediction is experimentally verified by examining the inter-edge angles of the exfoliated flakes of four typical 2D materials including graphene, MoS2, PtS2, and black phosphorus. This work not only sheds light on the mechanics of exfoliation of the 2D materials but also provides a new approach to deriving information of edge orientations of mechanically exfoliated 2D materials by data mining of their macroscopic geometric features.

Forests on the edge: Microenvironmental drivers of carbon cycle response to edge effects

Science.gov (United States)

Reinmann, A.; Hutyra, L.; Smith, I. A.; Thompson, J.

2017-12-01

Twenty percent of the world's forest is within 100 m of a forest edge, but much of our understanding of forest carbon (C) cycling comes from large, intact ecosystems, which creates an important mismatch between the landscapes we study and those we aim to characterize. The temperate broadleaf forest is the most heavily fragmented forest biome in the world and its growth and carbon storage responses to forest edge effects appear to be the opposite of those in the tropical and boreal regions. We used field measurements to quantify the drivers of temperate forest C cycling response to edge effects, characterizing vegetative growth, respiration, and forest structure. We find large gradients in air and soil temperature from the forest interior to edge (up to 4 and 10° C, respectively) and the magnitude of this gradient is inversely correlated to the size of the forest edge growth enhancement. Further, leaf area index increases with proximity to the forest edge. While we also find increases in soil respiration between the forest interior and edge, this flux is small relative to aboveground growth enhancement near the edge. These findings represent an important advancement in our understanding of forest C cycle response to edge effects and will greatly improve our capacity to constrain biogenic C fluxes in fragmented and heterogeneous landscapes.

Edge modulation of electronics and transport properties of cliff-edge phosphorene nanoribbons

Science.gov (United States)

Guo, Caixia; Wang, Tianxing; Xia, Congxin; Liu, Yufang

2017-12-01

Based on the first-principles calculations, we study the electronic structures and transport properties of cliff-like edge phosphorene nanoribbons (CPNRs), considering different types of edge passivation. The band structures of bare CPNRs possess the metallic features; while hydrogen (H), fluorine (F), chlorine (Cl) and oxygen (O) atoms-passivated CPNRs are semiconductor materials, and the band gap values monotonically decrease when the ribbon width increases. Moreover, the H and F-passivated CPNRs exhibit the direct band gap characteristics, while the Cl and O-passivated cases show the features of indirect band gap. In addition, the edge passivated CPNRs are more energetically stable than bare edge case. Meanwhile, our results also show that the transport properties of the CPNRs can be obviously influenced by the different edge passivation.

The impact of masculinity on safety oversights, safety priority and safety violations in two male-dominated occupations

DEFF Research Database (Denmark)

Nielsen, Kent; Hansen, Claus D.; Bloksgaard, Lotte

2015-01-01

Background Although men have a higher risk of occupational injuries than women the role of masculinity for organizational safety outcomes has only rarely been the object of research. Aim The current study investigated the association between masculinity and safety oversights, safety priority......-related context factors (safety leadership, commitment of the safety representative, and safety involvement) and three safety-related outcome factors (safety violations, safety oversights and safety priority) were administered twice 12 months apart to Danish ambulance workers (n = 1157) and slaughterhouse workers...

Integrated approach to knowledge acquisition and safety management of complex plants with emphasis on human factors

International Nuclear Information System (INIS)

Kosmowski, K.T.

1998-01-01

In this paper an integrated approach to the knowledge acquisition and safety management of complex industrial plants is proposed and outlined. The plant is considered within a man-technology-environment (MTE) system. The knowledge acquisition is aimed at the consequent reliability evaluation of human factor and probabilistic modeling of the plant. Properly structured initial knowledge is updated in life-time of the plant. The data and knowledge concerning the topology of safety related systems and their functions are created in a graphical CAD system and are object oriented. Safety oriented monitoring of the plant includes abnormal situations due to external and internal disturbances, failures of hard/software components and failures of human factor. The operation and safety related evidence is accumulated in special data bases. Data/knowledge bases are designed in such a way to support effectively the reliability and safety management of the plant. (author)

Edge-assignment and figure-ground segmentation in short-term visual matching.

Science.gov (United States)

Driver, J; Baylis, G C

1996-12-01

Eight experiments examined the role of edge-assignment in a contour matching task. Subjects judged whether the jagged vertical edge of a probe shape matched the jagged edge that divided two adjoining shapes in an immediately preceding figure-ground display. Segmentation factors biased assignment of this dividing edge toward a figural shape on just one of its sides. Subjects were faster and more accurate at matching when the probe edge had a corresponding assignment. The rapid emergence of this effect provides an on-line analog of the long-term memory advantage for figures over grounds which Rubin (1915/1958) reported. The present on-line advantage was found when figures were defined by relative contrast and size, or by symmetry, and could not be explained solely by the automatic drawing of attention toward the location of the figural region. However, deliberate attention to one region of an otherwise ambiguous figure-ground display did produce the advantage. We propose that one-sided assignment of dividing edges may be obligatory in vision.

Edge-spin-derived magnetism in few-layer MoS2 nanomeshes

Directory of Open Access Journals (Sweden)

G. Kondo

2017-12-01

Full Text Available Magnetism arising from edge spins is highly interesting, particularly in 2D atomically thin materials in which the influence of edges becomes more significant. Among such materials, molybdenum disulfide (MoS2; one of the transition metal dichalcogenide (TMD family is attracting significant attention. The causes for magnetism observed in the TMD family, including in MoS2, have been discussed by considering various aspects, such as pure zigzag atomic-structure edges, grain boundaries, and vacancies. Here, we report the observation of ferromagnetism (FM in few-layer MoS2 nanomeshes (NMs; honeycomb-like array of hexagonal nanopores with low-contamination and low-defect pore edges, which have been created by a specific non-lithographic method. We confirm robust FM arising from pore edges in oxygen(O-terminated MoS2-NMs at room temperature, while it disappears in hydrogen(H-terminated samples. The observed high-sensitivity of FM to NM structures and critical annealing temperatures suggest a possibility that the Mo-atom dangling bond in pore edge is a dominant factor for the FM.

Smoothness in Binomial Edge Ideals

Directory of Open Access Journals (Sweden)

Hamid Damadi

2016-06-01

Full Text Available In this paper we study some geometric properties of the algebraic set associated to the binomial edge ideal of a graph. We study the singularity and smoothness of the algebraic set associated to the binomial edge ideal of a graph. Some of these algebraic sets are irreducible and some of them are reducible. If every irreducible component of the algebraic set is smooth we call the graph an edge smooth graph, otherwise it is called an edge singular graph. We show that complete graphs are edge smooth and introduce two conditions such that the graph G is edge singular if and only if it satisfies these conditions. Then, it is shown that cycles and most of trees are edge singular. In addition, it is proved that complete bipartite graphs are edge smooth.

Human factors engineering design review acceptance criteria for the safety parameter display

International Nuclear Information System (INIS)

McGevna, V.; Peterson, L.R.

1981-01-01

This report contains human factors engineering design review acceptance criteria developed by the Human Factors Engineering Branch (HFEB) of the Nuclear Regulatory Commission (NRC) to use in evaluating designs of the Safety Parameter Display System (SPDS). These criteria were developed in response to the functional design criteria for the SPDS defined in NUREG-0696, Functional Criteria for Emergency Response Facilities. The purpose of this report is to identify design review acceptance criteria for the SPDS installed in the control room of a nuclear power plant. Use of computer driven cathode ray tube (CRT) displays is anticipated. General acceptance criteria for displays of plant safety status information by the SPDS are developed. In addition, specific SPDS review criteria corresponding to the SPDS functional criteria specified in NUREG-0696 are established

Human factors and fuzzy set theory for safety analysis

International Nuclear Information System (INIS)

Nishiwaki, Y.

1987-01-01

Human reliability and performance is affected by many factors: medical, physiological and psychological, etc. The uncertainty involved in human factors may not necessarily be probabilistic, but fuzzy. Therefore, it is important to develop a theory by which both the non-probabilistic uncertainties, or fuzziness, of human factors and the probabilistic properties of machines can be treated consistently. In reality, randomness and fuzziness are sometimes mixed. From the mathematical point of view, probabilistic measures may be considered a special case of fuzzy measures. Therefore, fuzzy set theory seems to be an effective tool for analysing man-machine systems. The concept 'failure possibility' based on fuzzy sets is suggested as an approach to safety analysis and fault diagnosis of a large complex system. Fuzzy measures and fuzzy integrals are introduced and their possible applications are also discussed. (author)

Probabilistic safety assessment model in consideration of human factors based on object-oriented bayesian networks

International Nuclear Information System (INIS)

Zhou Zhongbao; Zhou Jinglun; Sun Quan

2007-01-01

Effect of Human factors on system safety is increasingly serious, which is often ignored in traditional probabilistic safety assessment methods however. A new probabilistic safety assessment model based on object-oriented Bayesian networks is proposed in this paper. Human factors are integrated into the existed event sequence diagrams. Then the classes of the object-oriented Bayesian networks are constructed which are converted to latent Bayesian networks for inference. Finally, the inference results are integrated into event sequence diagrams for probabilistic safety assessment. The new method is applied to the accident of loss of coolant in a nuclear power plant. the results show that the model is not only applicable to real-time situation assessment, but also applicable to situation assessment based certain amount of information. The modeling complexity is kept down and the new method is appropriate to large complex systems due to the thoughts of object-oriented. (authors)

Cutting Edge Localisation in an Edge Profile Milling Head

NARCIS (Netherlands)

Fernandez Robles, Laura; Azzopardi, George; Alegre, Enrique; Petkov, Nicolai

2015-01-01

Wear evaluation of cutting tools is a key issue for prolonging their lifetime and ensuring high quality of products. In this paper, we present a method for the effective localisation of cutting edges of inserts in digital images of an edge profile milling head. We introduce a new image data set of

Edge colouring by total labellings

DEFF Research Database (Denmark)

Brandt, Stephan; Rautenbach, D.; Stiebitz, M.

2010-01-01

We introduce the concept of an edge-colouring total k-labelling. This is a labelling of the vertices and the edges of a graph G with labels 1, 2, ..., k such that the weights of the edges define a proper edge colouring of G. Here the weight of an edge is the sum of its label and the labels of its...

Gradient cuts and extremal edges in relative depth and figure-ground perception.

Science.gov (United States)

Ghose, Tandra; Palmer, Stephen E

2016-02-01

Extremal edges (EEs) are borders consisting of luminance gradients along the projected edge of a partly self-occluding curved surface (e.g., a cylinder), with equiluminant contours (ELCs) that run approximately parallel to that edge. Gradient cuts (GCs) are similar luminance gradients with ELCs that intersect (are "cut" by) an edge that could be due to occlusion. EEs are strongly biased toward being seen as closer/figural surfaces (Palmer & Ghose, Psychological Science, 19(1), 77-83, 2008). Do GCs produce a complementary bias toward being seen as ground? Experiment 1 shows that, with EEs on the opposite side, GCs produce a ground bias that increases with increasing ELC angles between ELCs and the shared edge. Experiment 2 shows that, with flat surfaces on the opposite side, GCs do not produce a ground bias, suggesting that more than one factor may be operating. We suggest that two partially dissociable factors may operate for curved surfaces-ELC angle and 3-D surface convexity-that reinforce each other in the figural cues of EEs but compete with each other in GCs. Moreover, this figural bias is modulated by the presence of EEs and GCs, as specified by the ELC angle between ELCs and the shared contour.

Safety, reliability, risk management and human factors: an integrated engineering approach applied to nuclear facilities

International Nuclear Information System (INIS)

Vasconcelos, Vanderley de; Silva, Eliane Magalhaes Pereira da; Costa, Antonio Carlos Lopes da; Reis, Sergio Carneiro dos

2009-01-01

Nuclear energy has an important engineering legacy to share with the conventional industry. Much of the development of the tools related to safety, reliability, risk management, and human factors are associated with nuclear plant processes, mainly because the public concern about nuclear power generation. Despite the close association between these subjects, there are some important different approaches. The reliability engineering approach uses several techniques to minimize the component failures that cause the failure of the complex systems. These techniques include, for instance, redundancy, diversity, standby sparing, safety factors, and reliability centered maintenance. On the other hand system safety is primarily concerned with hazard management, that is, the identification, evaluation and control of hazards. Rather than just look at failure rates or engineering strengths, system safety would examine the interactions among system components. The events that cause accidents may be complex combinations of component failures, faulty maintenance, design errors, human actions, or actuation of instrumentation and control. Then, system safety deals with a broader spectrum of risk management, including: ergonomics, legal requirements, quality control, public acceptance, political considerations, and many other non-technical influences. Taking care of these subjects individually can compromise the completeness of the analysis and the measures associated with both risk reduction, and safety and reliability increasing. Analyzing together the engineering systems and controls of a nuclear facility, their management systems and operational procedures, and the human factors engineering, many benefits can be realized. This paper proposes an integration of these issues based on the application of systems theory. (author)

Safety, reliability, risk management and human factors: an integrated engineering approach applied to nuclear facilities

Energy Technology Data Exchange (ETDEWEB)

Vasconcelos, Vanderley de; Silva, Eliane Magalhaes Pereira da; Costa, Antonio Carlos Lopes da; Reis, Sergio Carneiro dos [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)], e-mail: vasconv@cdtn.br, e-mail: silvaem@cdtn.br, e-mail: aclc@cdtn.br, e-mail: reissc@cdtn.br

2009-07-01

Nuclear energy has an important engineering legacy to share with the conventional industry. Much of the development of the tools related to safety, reliability, risk management, and human factors are associated with nuclear plant processes, mainly because the public concern about nuclear power generation. Despite the close association between these subjects, there are some important different approaches. The reliability engineering approach uses several techniques to minimize the component failures that cause the failure of the complex systems. These techniques include, for instance, redundancy, diversity, standby sparing, safety factors, and reliability centered maintenance. On the other hand system safety is primarily concerned with hazard management, that is, the identification, evaluation and control of hazards. Rather than just look at failure rates or engineering strengths, system safety would examine the interactions among system components. The events that cause accidents may be complex combinations of component failures, faulty maintenance, design errors, human actions, or actuation of instrumentation and control. Then, system safety deals with a broader spectrum of risk management, including: ergonomics, legal requirements, quality control, public acceptance, political considerations, and many other non-technical influences. Taking care of these subjects individually can compromise the completeness of the analysis and the measures associated with both risk reduction, and safety and reliability increasing. Analyzing together the engineering systems and controls of a nuclear facility, their management systems and operational procedures, and the human factors engineering, many benefits can be realized. This paper proposes an integration of these issues based on the application of systems theory. (author)

Experimental investigation of heat transfer and friction factor characteristics of thermosyphon solar water heater system fitted with spacer at the trailing edge of Left-Right twisted tapes

International Nuclear Information System (INIS)

Jaisankar, S.; Radhakrishnan, T.K.; Sheeba, K.N.; Suresh, S.

2009-01-01

Experimental investigation of heat transfer and friction factor characteristics of thermosyphon solar water heater with full length Left-Right twist, twist fitted with rod and spacer at the trailing edge for lengths of 100, 200 and 300 mm for twist ratio 3 and 5 has been studied. The experimental data for plain tube collector has been compared with fundamental equation within a discrepancy of ±7.41% and ±14.97% for Nusselt number and friction factor, respectively. Result shows that the Nusselt number decreases by 11% and 19% for twist fitted with rod and twist with spacer, respectively, when compared with full length twist. Friction factor also decreases by 18% and 29% for twist fitted with rod and spacer, respectively, as compared with full length twist. The heat enhancement in twist fitted with rod at the trailing edge is maximum when compared with twist fitted with spacer because the swirl flow is maintained throughout the length of rod.

Understanding human and organisational factors - Nuclear safety and at-risk organisations

International Nuclear Information System (INIS)

Bernard, Benoit

2014-01-01

This book addresses human and organisational factors which are present at different moments of the lifetime of an at-risk installation (from design to dismantling). At-risk organisations are considered as firstly human systems, and the objective is then to highlight individual and collective mechanisms in these organisations. Several questions are addressed, notably the origins of at-risk behaviour, and the reasons of the repetition of errors by these organisations. A first chapter, while referring to examples, addresses the human dimension of safety: human and organisational factors as obstacles, normal accidents (Three Mile Island), accidents in high-reliability organisations (Chernobyl), identification of root causes (Tokai-mura), and social-technical approach to safety (Fukushima). By also referring to examples, the second chapter addresses how to analyse at-risk organisations: individual behaviours (case of naval and air transport accidents), team coordination (a fire, the Challenger accident), and organisational regulation (organisations forms and routines, explosion of BP Texas City, explosion of Columbia)

Lyapunov-based distributed control of the safety-factor profile in a tokamak plasma

International Nuclear Information System (INIS)

Bribiesca Argomedo, Federico; Witrant, Emmanuel; Prieur, Christophe; Brémond, Sylvain; Nouailletas, Rémy; Artaud, Jean-François

2013-01-01

A real-time model-based controller is developed for the tracking of the distributed safety-factor profile in a tokamak plasma. Using relevant physical models and simplifying assumptions, theoretical stability and robustness guarantees were obtained using a Lyapunov function. This approach considers the couplings between the poloidal flux diffusion equation, the time-varying temperature profiles and an independent total plasma current control. The actuator chosen for the safety-factor profile tracking is the lower hybrid current drive, although the results presented can be easily extended to any non-inductive current source. The performance and robustness of the proposed control law is evaluated with a physics-oriented simulation code on Tore Supra experimental test cases. (paper)

The Impact of Organizational Factors on Safety. The Perspective of Experts from the Spanish Nuclear Sector

International Nuclear Information System (INIS)

German, S.; Silla, I.; Navajas, J.

2014-01-01

Previous research supports the importance of organizational factors on safety in high reliability organizations. This study aims to determine the impact of those factors in the Spanish nuclear sector. Particularly, this study focuses on examining the role of performance indicators, organizational culture, organizational factors, and organizational context. With that purpose, an electronic survey addressed to experts from the Spanish nuclear sector was carried out. Results showed that performance indicators are well-known among industry experts and are perceived as useful for improving performance. Behavioural norms that influence safety and some relevant factors that promote problem identification were identified. Additionally, findings suggested that organizational context must be taken into account to better understand the role of organizational culture. Moreover, industry experts pointed out organizational factors to be improved: organizational communication processes within the organization, positive reinforcement, and field supervisors practices. Finally, findings supported the influence of organizational context on safety. It is noteworthy the role of the social impact of international events (e.g., Chernobyl...), the relationship with the regulator and the legislative and governmental framework. (Author)

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

Role of rational surfaces on fluctuations and transport in the plasma edge of the TJ-II stellarator

International Nuclear Information System (INIS)

Pedrosa, M.A.; Hidalgo, C.; Lopez-Fraguas, A.

2000-01-01

It has been shown that transport barriers in toroidal magnetically confined plasmas tend to be linked to regions of unique magnetic topology such as the location of a minimum in the safety factor, rational surfaces or the boundary between closed and open flux surfaces. In the absence of E x B sheared flows, fluctuations are expected to show maximum amplitude near rational surfaces, and plasma confinement might tend to deteriorate. On the other hand, if the generation of E x B sheared flows were linked to low order rational surfaces, these would be beneficial to confinement. Experimental evidence of E x B sheared flows linked to rational surfaces has been obtained in the plasma edge region of the TJ-II stellarator. (author)

The PSA of safety-critical digital I and C system: the determination of important factors and sensitivity analysis

International Nuclear Information System (INIS)

Kang, H. G.; Sung, T. Y.; Eom, H. S.; Jeong, H. S.; Park, J. K.; Lee, K. Y.; Park, J. K.

2002-01-01

This report is prepared to suggest a practical Probabilistic Safety Assessment (PSA) methodology of safety-critical digital instrumentation and control (I and C) systems. Even though conventional probabilistic safety assessment methods are immature for applying to microprocessor-based digital systems, practical needs force to apply it because the result of probabilistic safety assessment plays very important role in proving the safety of a designed system. Microprocessors and software technologies make the digital system very complex and hard to analyze the safety of their applications. The aim of this is: (1) To summarize the factors which should be represented by the model for probabilistic safety assessment and to propose a standpoint of evaluation for digital systems. (2) To quantitatively presents the results of a mathematical case study which examines the analysis framework of the safety of digital systems in the context of the PSA. (3) To show the results of a sensitivity study for some critical factors

Factors influencing workers to follow food safety management systems in meat plants in Ontario, Canada.

Science.gov (United States)

Ball, Brita; Wilcock, Anne; Aung, May

2009-06-01

Small and medium sized food businesses have been slow to adopt food safety management systems (FSMSs) such as good manufacturing practices and Hazard Analysis Critical Control Point (HACCP). This study identifies factors influencing workers in their implementation of food safety practices in small and medium meat processing establishments in Ontario, Canada. A qualitative approach was used to explore in-plant factors that influence the implementation of FSMSs. Thirteen in-depth interviews in five meat plants and two focus group interviews were conducted. These generated 219 pages of verbatim transcripts which were analysed using NVivo 7 software. Main themes identified in the data related to production systems, organisational characteristics and employee characteristics. A socio-psychological model based on the theory of planned behaviour is proposed to describe how these themes and underlying sub-themes relate to FSMS implementation. Addressing the various factors that influence production workers is expected to enhance FSMS implementation and increase food safety.

Rationalization of safety factors for breakwater design in hurricane-prone areas

NARCIS (Netherlands)

Tsimopoulou, V.; Kanning, W.; Verhagen, H.J.; Vrijling, J.K.

2011-01-01

This paper presents the development of a semi-probabilistic method for armour layer design of rubble mound breakwaters, which is based on the use of safety factors. The objective is to introduce an approach that is both attractive to designers and sufficiently reliable when a high degree of

PSA methodology including new design, operational and safety factors, 'Level of recognition of phenomena with a presumed dominant influence upon operational safety' (failures of conventional as well as non-conventional passive components, dependent failures, influence of operator, fires and external threats, digital control, organizational factors)

International Nuclear Information System (INIS)

Jirsa, P.

2001-10-01

The document represents a specific type of discussion of existing methodologies for the creation and application of probabilistic safety assessment (PSA) in light of the EUR document summarizing requirements placed by Western European NPP operators on the future design of nuclear power plants. A partial goal of this discussion consists in mapping, from the PSA point of view, those selected design, operational and/or safety factors of future NPPs that may be entirely new or, at least, newly addressed. Therefore, the terms of reference for this stage were formulated as follows: Assess current level of knowledge and procedures in the analysis of factors and phenomena with a dominant influence upon operational safety of new generation reactors, especially in the following areas: (1) Phenomenology of failure types and mechanisms and reliability of conventional passive safety system components; (2) Phenomenology of failure types and mechanisms and reliability of non-conventional passive components of newly designed safety systems; (3) Phenomenology of types and mechanisms of dependent failures; (4) Human factor role in new generation reactors and its effect upon safety; (5) Fire safety and other external threats to new nuclear installations; (6) Reliability of the digital systems of the I and C system and their effect upon safety; and (7) Organizational factors in new nuclear installations. (P.A.)

National plan to enhance aviation safety through human factors improvements

Science.gov (United States)

Foushee, Clay

1990-01-01

The purpose of this section of the plan is to establish a development and implementation strategy plan for improving safety and efficiency in the Air Traffic Control (ATC) system. These improvements will be achieved through the proper applications of human factors considerations to the present and future systems. The program will have four basic goals: (1) prepare for the future system through proper hiring and training; (2) develop a controller work station team concept (managing human errors); (3) understand and address the human factors implications of negative system results; and (4) define the proper division of responsibilities and interactions between the human and the machine in ATC systems. This plan addresses six program elements which together address the overall purpose. The six program elements are: (1) determine principles of human-centered automation that will enhance aviation safety and the efficiency of the air traffic controller; (2) provide new and/or enhanced methods and techniques to measure, assess, and improve human performance in the ATC environment; (3) determine system needs and methods for information transfer between and within controller teams and between controller teams and the cockpit; (4) determine how new controller work station technology can optimally be applied and integrated to enhance safety and efficiency; (5) assess training needs and develop improved techniques and strategies for selection, training, and evaluation of controllers; and (6) develop standards, methods, and procedures for the certification and validation of human engineering in the design, testing, and implementation of any hardware or software system element which affects information flow to or from the human.

Human Factors Evaluation of Man-Machine Interface for Periodic Safety Review of Yonggwang Unit no. 1, 2

International Nuclear Information System (INIS)

Lee, Yong Hee; Lee, Jung Woon; Park, Jae Chang

2006-01-01

This report describes the research results of human factors assessment on the MMI(Man Machine Interface) equipment as part of Periodic Safety Review(PSR) of Yonggwang Unit no. 1, 2. As MMI is a key factor among human factors to be reviewed in PSR, we reviewed the MMI components of nuclear power plants in aspect of human factors engineering. The availability, suitability, and effectiveness of the MMI devices were chosen to be reviewed. The MMI devices were investigated through the review of design documents related to the MMI, survey of control panels, evaluation of experts, and experimental assessment. Checklists were used to perform this assessment and record the review results. The items mentioned by the expert comments to review in detail in relation with task procedures were tested by experiments with operators' participation. For some questionable issues arisen during this MMI review, operator workload and possibility of errors in operator actions were analysed. The reviewed MMI devices contain MCR(Main Control Room), SPDS(Safety Parameter Display System), RSP(Remote Shutdown Panel), and the selected LCBs(Local Control Boards) importantly related to safety. As results of the assessments, any significant problem challenging the safety was not found on human factors in the MMI devices. However, several small items to be changed and improved in suitability of MMI devices were discovered. An action plan is recommended to accommodate the suggestions and review comments. It will enhance the plant safety on MMI area

Human Factors Evaluation of Man-Machine Interface for Periodic Safety Review of Yonggwang Unit no. 1, 2

Energy Technology Data Exchange (ETDEWEB)

Lee, Yong Hee; Lee, Jung Woon; Park, Jae Chang (and others)

2006-01-15

This report describes the research results of human factors assessment on the MMI(Man Machine Interface) equipment as part of Periodic Safety Review(PSR) of Yonggwang Unit no. 1, 2. As MMI is a key factor among human factors to be reviewed in PSR, we reviewed the MMI components of nuclear power plants in aspect of human factors engineering. The availability, suitability, and effectiveness of the MMI devices were chosen to be reviewed. The MMI devices were investigated through the review of design documents related to the MMI, survey of control panels, evaluation of experts, and experimental assessment. Checklists were used to perform this assessment and record the review results. The items mentioned by the expert comments to review in detail in relation with task procedures were tested by experiments with operators' participation. For some questionable issues arisen during this MMI review, operator workload and possibility of errors in operator actions were analysed. The reviewed MMI devices contain MCR(Main Control Room), SPDS(Safety Parameter Display System), RSP(Remote Shutdown Panel), and the selected LCBs(Local Control Boards) importantly related to safety. As results of the assessments, any significant problem challenging the safety was not found on human factors in the MMI devices. However, several small items to be changed and improved in suitability of MMI devices were discovered. An action plan is recommended to accommodate the suggestions and review comments. It will enhance the plant safety on MMI area.

Propagation of superconducting coherence via chiral quantum-Hall edge channels.

Science.gov (United States)

Park, Geon-Hyoung; Kim, Minsoo; Watanabe, Kenji; Taniguchi, Takashi; Lee, Hu-Jong

2017-09-08

Recently, there has been significant interest in superconducting coherence via chiral quantum-Hall (QH) edge channels at an interface between a two-dimensional normal conductor and a superconductor (N-S) in a strong transverse magnetic field. In the field range where the superconductivity and the QH state coexist, the coherent confinement of electron- and hole-like quasiparticles by the interplay of Andreev reflection and the QH effect leads to the formation of Andreev edge states (AES) along the N-S interface. Here, we report the electrical conductance characteristics via the AES formed in graphene-superconductor hybrid systems in a three-terminal configuration. This measurement configuration, involving the QH edge states outside a graphene-S interface, allows the detection of the longitudinal and QH conductance separately, excluding the bulk contribution. Convincing evidence for the superconducting coherence and its propagation via the chiral QH edge channels is provided by the conductance enhancement on both the upstream and the downstream sides of the superconducting electrode as well as in bias spectroscopy results below the superconducting critical temperature. Propagation of superconducting coherence via QH edge states was more evident as more edge channels participate in the Andreev process for high filling factors with reduced valley-mixing scattering.

Development of edge effects around experimental ecosystem hotspots is affected by edge density and matrix type

Science.gov (United States)

Ecological edge effects are sensitive to landscape context. In particular, edge effects can be altered by matrix type and by the presence of other nearby edges. We experimentally altered patch configurations in an African savanna to determine how edge density and matrix type influence edge effect de...

Edge effects in composites

International Nuclear Information System (INIS)

Guz, A.N.; Kokhanenko, Yu.V.

1995-01-01

In the present article we survey papers on edge effects investigated by the rigorous approach. We interpret edge effects as stressed states created in a composite as a result of zones in which the stresses exhibit a rapidly changing behavior in comparison with the slow variation of the stresses outside such zones. Here the range of the edge effect is defined as the distance from the point of its inception to the boundary of the edge zone in a given direction. The transition of the stresses to the slowly varying state is determined within prescribed error limits. The size and configuration of the edge zone depends on the tolerated error. Clearly, the main difficulty associated with the rigorous approach is finding solutions of the elasticity problems. The finite-difference approach is suggested for the approximate solution of these problems. In light of the comparative time consumption of the finite-difference approach, it is best directed at certain classes of problems rather than at particular individual problems. Not too many papers on the investigation of edge effects by the rigorous approach have been published to date. Below, following in their footsteps, we formulate edge effect problems in composites, determine classes of problems, and investigate edge effects in composite materials and structural elements using them in Cartesian (planar and three-dimensional problems) and cylindrical (axisymmetric problems) coordinate frames. We note that the division of approaches to the study of edge effects into qualitative (nonrigorous) and quantitative (rigorous) reflects the authors own point of view. Of course, other schemes of classification of the approaches to the investigation of the regions of rapidly varying states in composites are possible

Optically Unraveling the Edge Chirality-Dependent Band Structure and Plasmon Damping in Graphene Edges.

Science.gov (United States)

Duan, Jiahua; Chen, Runkun; Cheng, Yuan; Yang, Tianzhong; Zhai, Feng; Dai, Qing; Chen, Jianing

2018-05-01

The nontrivial topological origin and pseudospinorial character of electron wavefunctions make edge states possess unusual electronic properties. Twenty years ago, the tight-binding model calculation predicted that zigzag termination of 2D sheets of carbon atoms have peculiar edge states, which show potential application in spintronics and modern information technologies. Although scanning probe microscopy is employed to capture this phenomenon, the experimental demonstration of its optical response remains challenging. Here, the propagating graphene plasmon provides an edge-selective polaritonic probe to directly detect and control the electronic edge state at ambient condition. Compared with armchair, the edge-band structure in the bandgap gives rise to additional optical absorption and strongly absorbed rim at zigzag edge. Furthermore, the optical conductivity is reconstructed and the anisotropic plasmon damping in graphene systems is revealed. The reported approach paves the way for detecting edge-specific phenomena in other van der Waals materials and topological insulators. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Defining safety culture and the nexus between safety goals and safety culture. 3. A Methodology for Identifying Deficiencies in Safety Culture

International Nuclear Information System (INIS)

Apostolakis, George; Weil, Rick

2001-01-01

At present, the drivers of performance problems at nuclear power plants (NPPs) are organizational in nature. Organizational deficiencies and other 'latent' conditions cause human errors, resulting in incidents that impact the performance of NPPs. Therefore, the human reliability community, regulators, and others concerned with NPP safety express the view that safety culture and organizational factors play an important role in plant safety. However, we have yet to identify one complete set of organizational factors, establish links between deficient safety culture and performance, or develop adequate tools to measure safety culture. This paper will contribute to the resolution of these issues. Safety culture is not a single factor but rather is a collection of several distinct factors. This paper asserts that in order to pro-actively manage safety culture at NPPs, leading indicators and appropriate measurements must be identified and developed. Central to this effort are the identification of the distinct factors comprising safety culture and the relationships between those factors and performance. We have identified several factors important to safety culture. We have developed a methodology that is a combination of traditional root-cause analysis and theories of human error, most notably Reason's theory of accident causation. In addition to this methodology's usefulness in identifying deficiencies in safety culture, it could also be used as a starting point to identify leading indicators of deteriorating safety performance. We have identified six organizational factors as being important: communication, formalization, goal prioritization, problem identification, roles and responsibilities, and technical knowledge. In addition, we have found that certain organizational factors, although pervasive throughout the organization, have a much greater influence on the successful outcome of particular tasks of work processes, rather than being equally important to all

Close-fitting shield doors with sculptured edges

International Nuclear Information System (INIS)

Goodman, L.

1986-01-01

The US Department of Energy has contracted with Fluor Technology, Inc. for design and engineering of a facility to begin reprocessing fuel from the reactors at Hanford, Washington. Within the facility, a 15-cm (6-in.)-thick, steel shield door is needed to close an opening 4.3 m (14 ft) high x 8.2 m (27 ft) wide. Two cranes and a centrally located monorail hoist must pass through the opening. The door weighs about 41,000 kg (45 ton), and passage of the hoist will be the most frequent cause for opening the door. These two factors essentially mandated a three-piece door, which allows for using commercially available chain hoists to raise and lower the individual door sections. Normally, there is a 187-Pa (0.75-in. water gauge) pressure differential across the door, and minimal air leakage is essential. Stepped, mating edges between sections and along the adjacent concrete structures are typical with such doors, but so are significant gaps (and air leaks) around the edges. Gaps are needed to preclude frictional jamming between edges as a section is lowered. The challenge was to conceive a method to produce near-zero gaps and preclude jamming without involving impractically tight tolerances. The chosen method was to place trapezoidally shaped, steel gaskets on the door-section edges and on the mating concrete surfaces. The concept is described

Heat Transfer and Friction Studies in a Tilted and Rib-Roughened Trailing-Edge Cooling Cavity with and without the Trailing-Edge Cooling Holes

Directory of Open Access Journals (Sweden)

M. E. Taslim

2014-01-01

Full Text Available Local and average heat transfer coefficients and friction factors were measured in a test section simulating the trailing-edge cooling cavity of a turbine airfoil. The test rig with a trapezoidal cross-sectional area was rib-roughened on two opposite sides of the trapezoid (airfoil pressure and suction sides with tapered ribs to conform to the cooling cavity shape and had a 22-degree tilt in the flow direction upstream of the ribs that affected the heat transfer coefficients on the two rib-roughened surfaces. The radial cooling flow traveled from the airfoil root to the tip while exiting through 22 cooling holes along the airfoil trailing-edge. Two rib geometries, with and without the presence of the trailing-edge cooling holes, were examined. The numerical model contained the entire trailing-edge channel, ribs, and trailing-edge cooling holes to simulate exactly the tested geometry. A pressure-correction based, multiblock, multigrid, unstructured/adaptive commercial software was used in this investigation. Realizable k-ε turbulence model in conjunction with enhanced wall treatment approach for the near wall regions was used for turbulence closure. The applied thermal boundary conditions to the CFD models matched the test boundary conditions. Comparisons are made between the experimental and numerical results.

The consideration of the humane factor is essential in safety systems

International Nuclear Information System (INIS)

Parisot, F.

2010-01-01

In most risk analysis we consider that the staff fit perfectly the tasks to do in terms of training and competence but in fact a lot of factors intervene like the level of stress of the operator, the time available to identify the trouble or to take a decision, the relevance of the procedures, or the level of coordination and communication between the members of the staff. Different methods exist to assess the human factor, most have been designed to be used in the nuclear sector for instance: THERP (Technique for Human Error Rate Prediction) or OATS (Operation Action Tree) or SHARP (Systematic Human Action Reliability Procedure). These methods apply as early as the design stage of the engineered safety systems. Virtual reality has entered these methods because it allows operators to learn by making errors since errors in virtual reality have no consequences. Learning by making errors is an efficient method to get the operator used to accidental situations and as a consequence to reduce his level of stress. Some methods incorporate human elements into system safety analysis through the definition of performance shaping factors that describe the behaviour of operators in terms of physical and psychological abilities. (A.C.)

Infective endocarditis following transcatheter edge-to-edge mitral valve repair: A systematic review.

Science.gov (United States)

Asmarats, Lluis; Rodriguez-Gabella, Tania; Chamandi, Chekrallah; Bernier, Mathieu; Beaudoin, Jonathan; O'Connor, Kim; Dumont, Eric; Dagenais, François; Paradis, Jean-Michel; Rodés-Cabau, Josep

2018-05-10

To assess the clinical characteristics, management, and outcomes of patients diagnosed with infective endocarditis (IE) after edge-to-edge mitral valve repair with the MitraClip device. Transcatheter edge-to-edge mitral valve repair has emerged as an alternative to surgery in high-risk patients. However, few data exist on IE following transcatheter mitral procedures. Four electronic databases (PubMed, Google Scholar, Embase, and Cochrane Library) were searched for original published studies on IE after edge-to-edge transcatheter mitral valve repair from 2003 to 2017. A total of 10 publications describing 12 patients with definitive IE (median age 76 years, 55% men) were found. The mean logistic EuroSCORE/EuroSCORE II were 41% and 45%, respectively. The IE episode occurred early (within 12 months post-procedure) in nine patients (75%; within the first month in five patients). Staphylococcus aureus was the most frequent (60%) causal microorganism, and severe mitral regurgitation was present in all cases but one. Surgical mitral valve replacement (SMVR) was performed in most (67%) patients, and the mortality associated with the IE episode was high (42%). IE following transcatheter edge-to-edge mitral valve repair is a rare but life-threatening complication, usually necessitating SMVR despite the high-risk profile of the patients. These results highlight the importance of adequate preventive measures and a prompt diagnosis and treatment of this serious complication. © 2018 Wiley Periodicals, Inc.

Nonreference Medical Image Edge Map Measure

Directory of Open Access Journals (Sweden)

Karen Panetta

2014-01-01

Full Text Available Edge detection is a key step in medical image processing. It is widely used to extract features, perform segmentation, and further assist in diagnosis. A poor quality edge map can result in false alarms and misses in cancer detection algorithms. Therefore, it is necessary to have a reliable edge measure to assist in selecting the optimal edge map. Existing reference based edge measures require a ground truth edge map to evaluate the similarity between the generated edge map and the ground truth. However, the ground truth images are not available for medical images. Therefore, a nonreference edge measure is ideal for medical image processing applications. In this paper, a nonreference reconstruction based edge map evaluation (NREM is proposed. The theoretical basis is that a good edge map keeps the structure and details of the original image thus would yield a good reconstructed image. The NREM is based on comparing the similarity between the reconstructed image with the original image using this concept. The edge measure is used for selecting the optimal edge detection algorithm and optimal parameters for the algorithm. Experimental results show that the quantitative evaluations given by the edge measure have good correlations with human visual analysis.

Nanoindentation near the edge

Science.gov (United States)

J.E. Jakes; C.R. Frihart; J.F. Beecher; R.J. Moon; P.J. Resto; Z.H. Melgarejo; O.M. Saurez; H. Baumgart; A.A. Elmustafa; D.S. Stone

2009-01-01

Whenever a nanoindent is placed near an edge, such as the free edge of the specimen or heterophase interface intersecting the surface, the elastic discontinuity associated with the edge produces artifacts in the load-depth data. Unless properly handled in the data analysis, the artifacts can produce spurious results that obscure any real trends in properties as...

Influence of external resonant magnetic perturbation field on edge plasma of small tokamak HYBTOK-II

Energy Technology Data Exchange (ETDEWEB)

Hayashi, Y., E-mail: hayashi-yuki13@ees.nagoya-u.ac.jp [Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Suzuki, Y.; Ohno, N. [Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Okamoto, M. [Ishikawa National College of Technology, Kitachujo, Tsubata-cho, Kahoku-gun, Ishikawa 929-0392 (Japan); Kikuchi, Y. [University of Hyogo, 2167 Shosha, Himeji, Hyogo 671-2280 (Japan); Sakakibara, S.; Watanabe, K.; Takemura, Y. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292 (Japan)

2015-08-15

Radial profile of externally applied resonant magnetic perturbation (RMP) field with mode numbers of m = 6 and n = 2 in a small tokamak device HYBTOK-II have been investigated using a magnetic probe array, which is able to measure the radial profile of magnetic field perturbation induced by applying RMP. Results of RMP penetration into the plasma show that the RMP decreased toward the plasma center, while they were amplified around the resonant surface with a safety factor q = 3 due to the formation of magnetic islands. This suggests that RMP fields for controlling edge plasmas may trigger some kind of MHD instabilities. In addition, simulation results, based on a linearized four-field model, which agrees with the experimental ones, indicates that the penetration and amplification process of RMP strongly depend on a Doppler-shifted frequency between the RMP and plasma rotation.

Effects of a Workplace Intervention Targeting Psychosocial Risk Factors on Safety and Health Outcomes

Science.gov (United States)

Hammer, Leslie B.; Truxillo, Donald M.; Bodner, Todd; Rineer, Jennifer; Pytlovany, Amy C.; Richman, Amy

2015-01-01

The goal of this study was to test the effectiveness of a workplace intervention targeting work-life stress and safety-related psychosocial risk factors on health and safety outcomes. Data were collected over time using a randomized control trial design with 264 construction workers employed in an urban municipal department. The intervention involved family- and safety-supportive supervisor behavior training (computer-based), followed by two weeks of behavior tracking and a four-hour, facilitated team effectiveness session including supervisors and employees. A significant positive intervention effect was found for an objective measure of blood pressure at the 12-month follow-up. However, no significant intervention results were found for self-reported general health, safety participation, or safety compliance. These findings suggest that an intervention focused on supervisor support training and a team effectiveness process for planning and problem solving should be further refined and utilized in order to improve employee health with additional research on the beneficial effects on worker safety. PMID:26557703

Effects of a Workplace Intervention Targeting Psychosocial Risk Factors on Safety and Health Outcomes

Directory of Open Access Journals (Sweden)

Leslie B. Hammer

2015-01-01

Full Text Available The goal of this study was to test the effectiveness of a workplace intervention targeting work-life stress and safety-related psychosocial risk factors on health and safety outcomes. Data were collected over time using a randomized control trial design with 264 construction workers employed in an urban municipal department. The intervention involved family- and safety-supportive supervisor behavior training (computer-based, followed by two weeks of behavior tracking and a four-hour, facilitated team effectiveness session including supervisors and employees. A significant positive intervention effect was found for an objective measure of blood pressure at the 12-month follow-up. However, no significant intervention results were found for self-reported general health, safety participation, or safety compliance. These findings suggest that an intervention focused on supervisor support training and a team effectiveness process for planning and problem solving should be further refined and utilized in order to improve employee health with additional research on the beneficial effects on worker safety.

Ways of increasing safety in mining at the Berezovskii-1 surface mine

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, N N; Malyarenko, V I

1986-12-01

Methods are descrubed wgucg were developed to alleviate or prevent the effects of landslides in a Kansk-Achinsk surface mine. Such a landslide took place in 1983 at the Berezovskii-1 mine when 250 m of an excavation trench suffered a collapse involving 680,000 mT of materials. Surveys revealed large zones of flooded ground with high proportions of argillites and aleurolites which swell in the presence of water. To keep costs down, a method using gravity is proposed for safety of re-excavation work near spoil banks. In this method a pillar of rock is left at the base of the spoil bank, the edge of the slope of which is moved back from the trench. Hard rock is placed at the leading edge of the spoil bank. The stability factor of the trench side may be raised from 0.87 to 1.12, and this is accompanied by savings in labor and costs.

Operation, Safety and Human: Critical Factors for the Success of Railway Transportation

NARCIS (Netherlands)

Rajabali Nejad, Mohammadreza; Martinetti, Alberto; van Dongen, Leonardus Adriana Maria

2016-01-01

This paper focuses on three categories of performance indicators for railway transportation: the excellence of operation, system safety and human factors. These are among the most critical indicators for delivering high quality services. This paper discusses the main issues, challenges and future

Edge subdivision and edge multisubdivision versus some domination related parameters in generalized corona graphs

Directory of Open Access Journals (Sweden)

Magda Dettlaff

2016-01-01

Full Text Available Given a graph \\(G=(V,E\\, the subdivision of an edge \\(e=uv\\in E(G\\ means the substitution of the edge \\(e\\ by a vertex \\(x\\ and the new edges \\(ux\\ and \\(xv\\. The domination subdivision number of a graph \\(G\\ is the minimum number of edges of \\(G\\ which must be subdivided (where each edge can be subdivided at most once in order to increase the domination number. Also, the domination multisubdivision number of \\(G\\ is the minimum number of subdivisions which must be done in one edge such that the domination number increases. Moreover, the concepts of paired domination and independent domination subdivision (respectively multisubdivision numbers are defined similarly. In this paper we study the domination, paired domination and independent domination (subdivision and multisubdivision numbers of the generalized corona graphs.

Risk factors for fishermen’s health and safety in Greece

DEFF Research Database (Denmark)

Frantzeskou, Elpida; Kastania, Anastasia N; Riza, Elena

2013-01-01

Aim: The aim of the study is to determine the risks for health and safety in Greek fisheries workers by exploring their health status and the health risk factors present in their occupational environment, thus providing a current baseline for further research in the future and for documentation....... The health risks factors studied include excessive weight, cardiovascular incidents and dermatological, musculoskeletal, respiratory, hearing, stress, and anxiety problems. The occupational health risk factors include alcohol, fatty food consumption, smoking, and lack of physical exercise. Conclusions......: The health effects observed are causally related to diet, smoking, and exercise, which in turn relate to the specific working conditions and culture in small-scale fishing that need to be taken into consideration in prevention programmes. The results are comparable withinternational fisheries experience...

Smoke without fire: a reply to Hardy, Segatore and Edge.

Science.gov (United States)

Stones, M J; Turner, K

1993-12-01

Literacy is defined in the Oxford English Dictionary as the ability to read and write, and illiteracy as an inability to read. Hardy, Segatore and Edge (1993) suggest a serious problem of illiteracy among student nurses that endangers patient safety. Their evidence is entirely anecdotal, some of which is misclassified as literacy errors. They provide no substantive or statistical evidence to support their claims. Educators making serious and provocative charges on such flimsy grounds ought either to recant or obtain evidence that is more convincing.

29 CFR 2200.108 - Official Seal of the Occupational Safety and Health Review Commission.

Science.gov (United States)

2010-07-01

... 29 Labor 9 2010-07-01 2010-07-01 false Official Seal of the Occupational Safety and Health Review... Occupational Safety and Health Review Commission. The seal of the Commission shall consist of: A gold eagle... background, encircled by a white band edged in black and inscribed “Occupational Safety and Health Review...

A Methodology To Incorporate The Safety Culture Into Probabilistic Safety Assessments

Energy Technology Data Exchange (ETDEWEB)

Park, Sunghyun; Kim, Namyeong; Jae, Moosung [Hanyang University, Seoul (Korea, Republic of)

2015-10-15

In order to incorporate organizational factors into PSA, a methodology needs to be developed. Using the AHP to weigh organizational factors as well as the SLIM to rate those factors, a methodology is introduced in this study. The safety issues related to nuclear safety culture have occurred increasingly. The quantification tool has to be developed in order to include the organizational factor into Probabilistic Safety Assessments. In this study, the state-of-the-art for the organizational evaluation methodologies has been surveyed. This study includes the research for organizational factors, maintenance process, maintenance process analysis models, a quantitative methodology using Analytic Hierarchy Process, Success Likelihood Index Methodology. The purpose of this study is to develop a methodology to incorporate the safety culture into PSA for obtaining more objective risk than before. The organizational factor considered in nuclear safety culture might affect the potential risk of human error and hardware-failure. The safety culture impact index to monitor the plant safety culture can be assessed by applying the developed methodology into a nuclear power plant.

A Methodology To Incorporate The Safety Culture Into Probabilistic Safety Assessments

International Nuclear Information System (INIS)

Park, Sunghyun; Kim, Namyeong; Jae, Moosung

2015-01-01

In order to incorporate organizational factors into PSA, a methodology needs to be developed. Using the AHP to weigh organizational factors as well as the SLIM to rate those factors, a methodology is introduced in this study. The safety issues related to nuclear safety culture have occurred increasingly. The quantification tool has to be developed in order to include the organizational factor into Probabilistic Safety Assessments. In this study, the state-of-the-art for the organizational evaluation methodologies has been surveyed. This study includes the research for organizational factors, maintenance process, maintenance process analysis models, a quantitative methodology using Analytic Hierarchy Process, Success Likelihood Index Methodology. The purpose of this study is to develop a methodology to incorporate the safety culture into PSA for obtaining more objective risk than before. The organizational factor considered in nuclear safety culture might affect the potential risk of human error and hardware-failure. The safety culture impact index to monitor the plant safety culture can be assessed by applying the developed methodology into a nuclear power plant

Adobe Edge Preview 3

CERN Document Server

Grover, Chris

2011-01-01

Want to use an Adobe tool to design animated web graphics that work on iPhone and iPad? You've come to the right book. Adobe Edge Preview 3: The Missing Manual shows you how to build HTML5 graphics using simple visual tools. No programming experience? No problem. Adobe Edge writes the underlying code for you. With this eBook, you'll be designing great-looking web elements in no time. Get to know the workspace. Learn how Adobe Edge Preview 3 performs its magic.Create and import graphics. Make drawings with Edge's tools, or use art you designed in other programs.Work with text. Build menus, lab

Internal barrier discharges in JET and their sensitivity to edge conditions

International Nuclear Information System (INIS)

Sips, A.C.C.

2001-01-01

Experiments in JET have concentrated on steady state discharges with internal transport barriers. The internal transport barriers are formed during the current rise phase of the discharge with low magnetic shear in the centre and with high additional heating power. In order to achieve stability against disruptions at high pressure peaking, typical for ITB discharges, the pressure profile can be broadened with a H-mode transport barrier at the edge of the plasma. However, the strong increase in edge pressure during an ELM free H-mode weakens the internal transport barrier due to a reduction of the rotational shear and pressure gradient at the ITB location. In addition, type I ELM activity, associated with a high edge pedestal pressure, leads to a collapse of the ITB with the input powers available in JET. The best ITB discharges are obtained with input power control to reduce to core pressure, and with the edge of the plasma controlled by argon gas dosing. These discharges achieve steady conditions for several energy confinement times with H97 confinement enhancement factors of 1.2-1.6 at line average densities around 30%-40% of the Greenwald density. This is at much lower density (typically factor 2 to 3) compared to standard H-mode discharges in JET. Increasing the density, using additional deuterium gas dosing or shallow pellet fueling has not been successful so far. A possible route to higher densities should maintain the type III ELM's towards high edge density, giving scope for future experiments in JET. (author)

Patient safety: Safety culture and patient safety ethics

DEFF Research Database (Denmark)

Madsen, Marlene Dyrløv

2006-01-01

,demonstrating significant, consistent and sometimes large differences in terms of safety culture factors across the units participating in the survey. Paper 5 is the results of a study of the relation between safety culture, occupational health andpatient safety using a safety culture questionnaire survey......Patient safety - the prevention of medical error and adverse events - and the initiative of developing safety cultures to assure patients from harm have become one of the central concerns in quality improvement in healthcare both nationally andinternationally. This subject raises numerous...... challenging issues of systemic, organisational, cultural and ethical relevance, which this dissertation seeks to address through the application of different disciplinary approaches. The main focus of researchis safety culture; through empirical and theoretical studies to comprehend the phenomenon, address...

Defining the patient safety attitudes and influencing factors of health professionals working at maternity hospitals.

Science.gov (United States)

Tunçer Ünver, Gamze; Harmanci Seren, Arzu Kader

2018-02-27

To determine patient safety attitudes of midwives, nurses and physicians and to examine the difference or correlation in patient safety attitudes of midwives, nurses and physicians working in maternity hospitals. It has been suggested that it is necessary to define the factors affecting patient safety attitudes of health professionals working in maternity hospitals. A descriptive and correlational design was employed.The sample comprised 58 midwives, 134 nurses and 63 physicians (255) in two maternity hospitals in Istanbul, Turkey. The data were collected using an 'information form' and a 'Patient Safety Attitude Questionnaire'. The safety attitudes of participants were generally found to be negative. However, midwives had more positive patient safety attitudes and the age, unit, adequacy of patient safety training and the importance of patient safety were the most effective variables. As health professionals working in maternity hospitals generally have negative patient safety attitudes and because patient safety training provided better attitudes among the participants, these training programmes should be developed and implemented considering the differences among age groups and units. Health professionals have different views on the patient safety culture; therefore, training needs to involve everyone to create a shared vision for patient safety. © 2018 John Wiley & Sons Ltd.

Intercultural Knowledge Flows in Edge Organizations: Trust as an Enabler

National Research Council Canada - National Science Library

Gavrieli, Dana A; Scott, W. R

2005-01-01

...., across military services and coalition partners) and knowledge flows. A major factor that emerges as an enabler of knowledge flows, especially in dynamic environments such as those in which Edge organizations operate, is trust...

Application of classification algorithms for analysis of road safety risk factor dependencies.

Science.gov (United States)

Kwon, Oh Hoon; Rhee, Wonjong; Yoon, Yoonjin

2015-02-01

Transportation continues to be an integral part of modern life, and the importance of road traffic safety cannot be overstated. Consequently, recent road traffic safety studies have focused on analysis of risk factors that impact fatality and injury level (severity) of traffic accidents. While some of the risk factors, such as drug use and drinking, are widely known to affect severity, an accurate modeling of their influences is still an open research topic. Furthermore, there are innumerable risk factors that are waiting to be discovered or analyzed. A promising approach is to investigate historical traffic accident data that have been collected in the past decades. This study inspects traffic accident reports that have been accumulated by the California Highway Patrol (CHP) since 1973 for which each accident report contains around 100 data fields. Among them, we investigate 25 fields between 2004 and 2010 that are most relevant to car accidents. Using two classification methods, the Naive Bayes classifier and the decision tree classifier, the relative importance of the data fields, i.e., risk factors, is revealed with respect to the resulting severity level. Performances of the classifiers are compared to each other and a binary logistic regression model is used as the basis for the comparisons. Some of the high-ranking risk factors are found to be strongly dependent on each other, and their incremental gains on estimating or modeling severity level are evaluated quantitatively. The analysis shows that only a handful of the risk factors in the data dominate the severity level and that dependency among the top risk factors is an imperative trait to consider for an accurate analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

Brief Talk about Lithium-ion Batteries’ Safety and Influencing Factors

Science.gov (United States)

Jin, Cheng

2017-12-01

A brief introduction of the development background, the concept, characteristic and advantages of lithium-ion battery was given. The typical fire accidents about lithium-ion battery in production process, the vehicle with new energy, portable electronic products were summarized. Some important factors for lithium-ion batteries’ safety were emphatically analyzed. Several constructive suggestions on improvement direction were given, meanwhile, we have a nice exception on the future of lithium-ion battery industry.

Partial safety factor calibration from stochastic finite element computation of welded joint with random geometries

International Nuclear Information System (INIS)

Schoefs, Franck; Chevreuil, Mathilde; Pasqualini, Olivier; Cazuguel, Mikaël

2016-01-01

Welded joints are used in various structures and infrastructures like bridges, ships and offshore structures, and are submitted to cyclic stresses. Their fatigue behaviour is an industrial key issue to deal with and still offers original research subjects. One of the available methods relies on the computing of the stress concentration factor. Even if some studies were previously driven to evaluate this factor onto some cases of welded structures, the shape of the weld joint is generally idealized through a deterministic parametric geometry. Previous experimental works however have shown that this shape plays a key role in the lifetime assessment. We propose in this paper a methodology for computing the stress concentration factor in presence of random geometries of welded joints. In view to make the results available by engineers, this method merges stochastic computation and semi-probabilistic analysis by computing partial safety factors with a dedicated method. - Highlights: • Numerical computation of stress concentration factor with random geometry of weld. • Real data are used for probabilistic modelling. • Identification of partial safety factor from SFEM computation in case of random geometries.

FATIGUE AS A HAZARDOUS FACTOR FOR FLIGHT SAFETY

Directory of Open Access Journals (Sweden)

M. Lushkin Alexander

2017-01-01

Full Text Available The main priority of any air company activity and the main condition for its development is the achievement of the highest flight safety level. Significant positive results in this area have been recently achieved, hence, the relative stagna- tion of indexes, reflecting the flight safety as a condition of air transport system, has been revealed. It has become evident that the present accident prevention philosophy seems to be exhausted, and at the current stage of development it doesn’t allow to make a breakthrough in the solution of all the problems, which air companies face in this respect. In the perspec- tive to find new ways to solve the existing tasks, in 2011, International Civil Aviation Organization Council adopted fatigue risk management international standards as an alternative for the traditional approach to managing crewmember fatigue by prescribing limits on maximum daily, monthly and yearly flight and duty hours. It’s a well-known fact that state of fatigue has a special place among the functional states, which are professionally significant for airmen work and which are the key link in “man-aircraft-environment” system.In this article, fatigue is considered to be a risk factor that contributes to the formation and development of crew violations and errors in the process of piloting the aircraft. We have analyzed the characteristics and reasons leading to in- flight fatigue and estimated its influence on crew performance, considering the interrelation between them. The article specifies the methods and techniques to measure pilots fatigue; besides it has been substantiated the necessity of fatigue risk management system development in airlines to effectively ensure the flight safety.

Generalized Multi-Edge Analysis for K-Edge Densitometry

International Nuclear Information System (INIS)

Collins, M.

1998-01-01

In K-edge densitometry (KED), a continuous-energy x-ray beam is transmitted through a liquid sample. The actinide content of the sample can be measured through analysis of the transmitted portion of the x-ray beam. Traditional methods for KED analysis allow the simultaneous calculation of, at most, two actinide concentrations. A generalized multi-edge KED analytical method is presented, allowing up to six actinide concentrations to be calculated simultaneously. Applications of this method for hybrid KED/x-ray fluorescence (HKED) systems are discussed. Current HKED systems require the operator to know the approximate actinide content of each sample, and manually select the proper analysis mode. The new multi-edge KED technique allows rapid identification of the major actinide components in a sample, independent of actinide content. The proper HKED analysis mode can be selected automatically, without requiring sample content information from the user. Automatic HKED analysis would be especially useful in an analytical laboratory setting, where samples with truly unknown characteristics are encountered. Because this technique requires no hardware modifications, several facilities that use HKED may eventually benefit from this approach

Safety climate and attitude as evaluation measures of organizational safety.

Science.gov (United States)

Isla Díaz, R; Díaz Cabrera, D

1997-09-01

The main aim of this research is to develop a set of evaluation measures for safety attitudes and safety climate. Specifically it is intended: (a) to test the instruments; (b) to identify the essential dimensions of the safety climate in the airport ground handling companies; (c) to assess the quality of the differences in the safety climate for each company and its relation to the accident rate; (d) to analyse the relationship between attitudes and safety climate; and (e) to evaluate the influences of situational and personal factors on both safety climate and attitude. The study sample consisted of 166 subjects from three airport companies. Specifically, this research was centered on ground handling departments. The factor analysis of the safety climate instrument resulted in six factors which explained 69.8% of the total variance. We found significant differences in safety attitudes and climate in relation to type of enterprise.

Predicting safety culture: the roles of employer, operations manager and safety professional.

Science.gov (United States)

Wu, Tsung-Chih; Lin, Chia-Hung; Shiau, Sen-Yu

2010-10-01

This study explores predictive factors in safety culture. In 2008, a sample 939 employees was drawn from 22 departments of a telecoms firm in five regions in central Taiwan. The sample completed a questionnaire containing four scales: the employer safety leadership scale, the operations manager safety leadership scale, the safety professional safety leadership scale, and the safety culture scale. The sample was then randomly split into two subsamples. One subsample was used for measures development, one for the empirical study. A stepwise regression analysis found four factors with a significant impact on safety culture (R²=0.337): safety informing by operations managers; safety caring by employers; and safety coordination and safety regulation by safety professionals. Safety informing by operations managers (ß=0.213) was by far the most significant predictive factor. The findings of this study provide a framework for promoting a positive safety culture at the group level. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Analysis of contributing factors associated to related patients safety incidents in Intensive Care Medicine.

Science.gov (United States)

Martín Delgado, M C; Merino de Cos, P; Sirgo Rodríguez, G; Álvarez Rodríguez, J; Gutiérrez Cía, I; Obón Azuara, B; Alonso Ovies, Á

2015-01-01

To explore contributing factors (CF) associated to related critical patients safety incidents. SYREC study pos hoc analysis. A total of 79 Intensive Care Departments were involved. The study sample consisted of 1.017 patients; 591 were affected by one or more incidents. The CF were categorized according to a proposed model by the National Patient Safety Agency from United Kingdom that was modified. Type, class and severity of the incidents was analyzed. A total 2,965 CF were reported (1,729 were associated to near miss and 1,236 to adverse events). The CF group more frequently reported were related patients factors. Individual factors were reported more frequently in near miss and task related CF in adverse events. CF were reported in all classes of incidents. The majority of CF were reported in the incidents classified such as less serious, even thought CF patients factors were associated to serious incidents. Individual factors were considered like avoidable and patients factors as unavoidable. The CF group more frequently reported were patient factors and was associated to more severe and unavoidable incidents. By contrast, individual factors were associated to less severe and avoidable incidents. In general, CF most frequently reported were associated to near miss. Copyright © 2014 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

Canopy gap edge determination and the importance of gap edges for plant diversity

Directory of Open Access Journals (Sweden)

D. Salvador-Van Eysenrode

2002-01-01

Full Text Available Canopy gaps, i.e. openings in the forest cover caused by the fall of structural elements, are considered to be important for the maintenance of diversity and for the forest cycle. A gap can be considered as a young forest patch in the forest matrix, composed of interior surrounded by an edge, both enclosed by a perimeter. Much of the attention has been focused on the gap interior. However, at gap edges the spectrum of regeneration opportunities for plants may be larger than in the interior. Although definitions of gap are still discussed, any definition can describe it in an acceptable way, if justified, but defining edges is complicated and appropriate descriptors should be used. A method to determine gap interior and edge, using light as a descriptor, is presented with an example of gaps from a beech forest (Fagus sylvatica in Belgium. Also, the relevance and implications of gap edges for plant diversity and calculation of forest turnover is discussed.

The Edge supersonic transport

Science.gov (United States)

Agosta, Roxana; Bilbija, Dushan; Deutsch, Marc; Gallant, David; Rose, Don; Shreve, Gene; Smario, David; Suffredini, Brian

1992-01-01

As intercontinental business and tourism volumes continue their rapid expansion, the need to reduce travel times becomes increasingly acute. The Edge Supersonic Transport Aircraft is designed to meet this demand by the year 2015. With a maximum range of 5750 nm, a payload of 294 passengers and a cruising speed of M = 2.4, The Edge will cut current international flight durations in half, while maintaining competitive first class, business class, and economy class comfort levels. Moreover, this transport will render a minimal impact upon the environment, and will meet all Federal Aviation Administration Part 36, Stage III noise requirements. The cornerstone of The Edge's superior flight performance is its aerodynamically efficient, dual-configuration design incorporating variable-geometry wingtips. This arrangement combines the benefits of a high aspect ratio wing at takeoff and low cruising speeds with the high performance of an arrow-wing in supersonic cruise. And while the structural weight concerns relating to swinging wingtips are substantial, The Edge looks to ever-advancing material technologies to further increase its viability. Heeding well the lessons of the past, The Edge design holds economic feasibility as its primary focus. Therefore, in addition to its inherently superior aerodynamic performance, The Edge uses a lightweight, largely windowless configuration, relying on a synthetic vision system for outside viewing by both pilot and passengers. Additionally, a fly-by-light flight control system is incorporated to address aircraft supersonic cruise instability. The Edge will be produced at an estimated volume of 400 aircraft and will be offered to airlines in 2015 at $167 million per transport (1992 dollars).

Construction Safety And Health Factors At The Industry Level: The Case Of Singapore

Directory of Open Access Journals (Sweden)

Charles Y.J. Cheah

2007-12-01

Full Text Available The construction industry is one of the most hazardous industries due to the unique nature of its products and the processes involved. Recent occurrences of highly publicized construction site accidents in Singapore have highlighted the immediate needs for the local industry to address safety and attention at the industry level. The objective of this paper is to examine issues and critical factors affecting S&H standards in Singapore. Clearly, collective efforts should be pursued at the industry level as the country moves towards the ultimate safety management strategy of self-regulation. The findings also indicate that the challenge of making worksites safe should not be placed solely on the contractors but should be shared by all parties affecting the value chain of construction, including the developers, the consultants and the government. The factors identified through factor analysis may inform legislators and industry practitioners in terms of the sources of problems and help develop effective strategies for improvement. Some of the experiences mentioned in the paper could also be relevant to other countries facing similar circumstances.

Study of the round edge disk hole's effects on the frequency and wakefield in disc structure

International Nuclear Information System (INIS)

Wang Lanfa; Hou Mi; Zhang Chuang

2001-01-01

The effects of the round edge beam hole on the frequency and wake field are studied using variational method, which allows for rounded iris disk hole without any approximation in shape treatment. The frequencies and wake fields of accelerating mode and dipole mode are studied for different edge radius cases, including the flat edge shape that is often used to approximately represent the actual structure geometry. The edge hole shape has weak effect on the frequency, but strong effect on the wakefield. The study shows that the amounts of wake fields are not precise enough with the assumption of the flat edge beam hole as of round edge. The shape assumption brings loss factor 15% err for the most dangerous EH 16 mode

Factors on Enhancing the Competitive Edge and Attributes of Graduates as Inputs to the Development of Teacher Education Enhancement Program

Directory of Open Access Journals (Sweden)

Susan S. Janer

2015-11-01

Full Text Available In response to the CHED’s Higher Education Development Project and the need to track the status of Sorsogon State College (SSC teacher education graduates, this research was conceptualized. The study aims to gauge the teacher education program’s thrust of providing a quality and relevant education that could ensure worthwhile and appropriate employment opportunity to its graduates. Descriptive research design was employed in this study. Surveys, unstructured interviews, and documentary analysis were undertaken to gather pertinent data among the respondents. The study consists of 427 teacher education graduates who were selected through stratified random technique. This tracer study determined the employability of Teacher Education graduates in SSC, Sorsogon Campus from 2009 to 2013 with an end-view of proposing a Teacher Education Enhancement Program (TEEP to enhance the competitive edge of SSC Teacher Education graduates in all teaching job opportunities. The intellectual, social and linguistic attributes of the SSC graduates were likewise identified in this study. Some of the factors identified by the respondents that could help improve their competitive edge are the pre-service trainings, job placement program, teacher education curriculum enrichment, and Licensure Examination for Teachers (LET review program.

Insight and Lessons Learned on Organizational Factors and Safety Culture from the Review of Human Error-related Events of NPPs in Korea

International Nuclear Information System (INIS)

Kim, Ji Tae; Lee, Dhong Hoon; Choi, Young Sung

2014-01-01

Event investigation is one of the key means of enhancing nuclear safety deriving effective measures and preventing recurrences. However, it is difficult to analyze organizational factors and safety culture. This paper tries to review human error-related events from perspectives of organizational factors and safety culture, and to derive insights and lessons learned in developing the regulatory infrastructure of plant oversight on safety culture

Insight and Lessons Learned on Organizational Factors and Safety Culture from the Review of Human Error-related Events of NPPs in Korea

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji Tae; Lee, Dhong Hoon; Choi, Young Sung [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

2014-08-15

Event investigation is one of the key means of enhancing nuclear safety deriving effective measures and preventing recurrences. However, it is difficult to analyze organizational factors and safety culture. This paper tries to review human error-related events from perspectives of organizational factors and safety culture, and to derive insights and lessons learned in developing the regulatory infrastructure of plant oversight on safety culture.

Determination of Residual Forces in Mechanisms Assembled by Edge-Form Rolling

Directory of Open Access Journals (Sweden)

K. Turgut Gürsel

2011-03-01

Full Text Available Steering and suspension systems are components that supply driving safety in vehicles. For a correct working the mechanisms of these systems consist of many ball-joints that have different functions. Generally the ball-joints are assembled to systems in press-fit without any gaps, but even with residual forces. On the other hand excessive tightness causes high moments, which requires additional processes of manufacturing. But low tightness also creates gaps in joints. None of these conditions are desired. Manufacturing a ball-race that has long-life, low-friction and provides required working angles in every road condition, can be designed after long test processes and sample productions including lots of improvements. An important element of steering systems in vehicles is suspension ball-race that can be manufactured by assembling with plastic deformation after designing the ball-joint. In this study, during the manufacturing of the suspension ball-race supplying the motion transmission, the edge-form rolling process that is a subsection of rolling process of manufacturing methods based on plastic deformation was examined. Effects of pressure forces occurring after edge-form rolling in bearing systems at different values were studied by changing operation pressure of edge form rolling by means of specific numerical simulations.

Leadership and Management for Safety. General Safety Requirements

International Nuclear Information System (INIS)

2016-01-01

This Safety Requirements publication establishes requirements that support Principle 3 of the Fundamental Safety Principles in relation to establishing, sustaining and continuously improving leadership and management for safety and an integrated management system. It emphasizes that leadership for safety, management for safety, an effective management system and a systemic approach (i.e. an approach in which interactions between technical, human and organizational factors are duly considered) are all essential to the specification and application of adequate safety measures and to the fostering of a strong safety culture. Leadership and an effective management system will integrate safety, health, environmental, security, quality, human-and-organizational factor, societal and economic elements. The management system will ensure the fostering of a strong safety culture, regular assessment of performance and the application of lessons from experience. The publication is intended for use by regulatory bodies, operating organizations (registrants and licensees) and other organizations concerned with facilities and activities that give rise to radiation risks

[Role of some psycho-physiological factors on driving safety].

Science.gov (United States)

Bergomi, M; Vivoli, G; Rovesti, S; Bussetti, P; Ferrari, A; Vivoli, R

2010-01-01

Within a research project on the role played by human factors on road accidents, the aim of the present study is to evaluate, in young adults, the relationships between driver behaviour and personality factors as well as to assess the neuroendocrine correlates of psychological and behavioural factors investigated. Another aim is to estimate in what measure the performance levels are affected by demographic, psychological and chronobiological variables. It has been found a positive relation between highway code violations, extroversion trait of personality and Sensation Seeking scores, so confirming that this component of personality can affect risky behaviour. Furthermore the subjects more oriented to morningness chronotype were found to be prone to adopt safe driving behaviour. Regarding the relations of the neuroendocrine parameters and driving behaviour a positive correlation was observed between dopamine levels and frequency of driving violations while a negative relationship was found between adrenaline levels and frequency of driving errors. In conclusion the identification of psycho-physiological variables related to driving risky behaviour might be a useful instrument to design traffic safety programs tailored to high risk subjects.

Analysis on Pollution Factors in Asparagus Production and Research on Safety Production Technology

OpenAIRE

Ma, Liping; Hao, Bianqing; Qiao, Xiongwu

2013-01-01

Based on the analysis on the infection degree, infection law and influencing factors of the main diseases on asparagus and the analysis on the pollution factors in asparagus production such as blind pesticide use, atmospheric pollution and acid rain, the pollution of soil and fertilizer, this article proposes asparagus safety production technologies which include the selection of disease-resistant variety and suitable planting field, scientific and reasonable disease control, balanced fertili...

Edge waves excited by underwater landslides : scenarios in the sea of Marmara

Science.gov (United States)

Sinan Özeren, Mehmet; Postacioglu, Nazmi; Canlı, Umut; Gasperini, Luca

2014-05-01

In this work we quantify the travel distance of edge waves created by submarine landslide over slopes of finite length. Edge waves, if generated, can constitute severe coastal hazard because they can travel long distances along the shores. In the Sea of Marmara there are several submarine masses susceptible to slide in case of a big earthquake on the Main Marmara Fault and some damage scenarios might involve edge waves. The edge waves generated by landslide Tsunamis over slopes of infinite lenghts are recently studied by Sammarco and Renzi (Landslide tsunamis propagating along a plane beach, 2008, Journal of Fluid Mech.). However the infinite slope length assumption causes a perfect confinement of the waves over the coastal slope, thereby overestimating the edge wave damage. Because of this, in their work there is no alongshore length scale over which these waves can lose their energy. In the real worls, the off-shore limiting depth will be finite and the off-shore direction wave vector will not be completely complex, pointing to radiation damping of these edge waves. In this work we analytically quantify the amount of this damping and we estimate the travel distance of the edge waves along the shoreline as a function of the limiting depth. We examine some some scenarios in the north coast of the Sea of Marmara and the northern shelf to quantify the edge waves. Since the method does not require high-resolution numerical computing, it can be used to calculate the edge-wave related risk factor anywhere with submarine landslide risk.

Shuttle Wing Leading Edge Root Cause NDE Team Findings and Implementation of Quantitative Flash Infrared Thermography

Science.gov (United States)

Burke, Eric R.

2009-01-01

Comparison metrics can be established to reliably and repeatedly establish the health of the joggle region of the Orbiter Wing Leading Edge reinforced carbon carbon (RCC) panels. Using these metrics can greatly reduced the man hours needed to perform, wing leading edge scanning for service induced damage. These time savings have allowed for more thorough inspections to be preformed in the necessary areas with out affecting orbiter flow schedule. Using specialized local inspections allows for a larger margin of safety by allowing for more complete characterizations of panel defects. The presence of the t-seal during thermographic inspection can have adverse masking affects on ability properly characterize defects that exist in the joggle region of the RCC panels. This masking affect dictates the final specialized inspection should be preformed with the t-seal removed. Removal of the t-seal and use of the higher magnification optics has lead to the most effective and repeatable inspection method for characterizing and tracking defects in the wing leading edge. Through this study some inadequacies in the main health monitoring system for the orbiter wing leading edge have been identified and corrected. The use of metrics and local specialized inspection have lead to a greatly increased reliability and repeatable inspection of the shuttle wing leading edge.

Human Factors engineering criteria and design for the Hanford Waste Vitrification Plant preliminary safety analysis report

International Nuclear Information System (INIS)

Wise, J.A.; Schur, A.; Stitzel, J.C.L.

1993-09-01

This report provides a rationale and systematic methodology for bringing Human Factors into the safety design and operations of the Hanford Waste Vitrification Plant (HWVP). Human Factors focuses on how people perform work with tools and machine systems in designed settings. When the design of machine systems and settings take into account the capabilities and limitations of the individuals who use them, human performance can be enhanced while protecting against susceptibility to human error. The inclusion of Human Factors in the safety design of the HWVP is an essential ingredient to safe operation of the facility. The HWVP is a new construction, nonreactor nuclear facility designed to process radioactive wastes held in underground storage tanks into glass logs for permanent disposal. Its design and mission offer new opposites for implementing Human Factors while requiring some means for ensuring that the Human Factors assessments are sound, comprehensive, and appropriately directed

Influence of a falling edge on high power microwave pulse combination

Science.gov (United States)

Li, Jiawei; Huang, Wenhua; Zhu, Qi; Xiao, Renzhen; Shao, Hao

2016-07-01

This paper presents an explanation of the influence of a microwave falling edge on high-power microwave pulse combination. Through particle-in-cell simulations, we discover that the falling edge is the driving factor that limits the output power of the combined pulses. We demonstrate that the space charge field, which accumulates to become comparable to the E-field at the falling edge of the former pulse, will trap the electrons in the gas layer and decrease its energy to attain a high ionization rate. Hence, avalanche discharge, caused by trapped electrons, makes the plasma density to approach the critical density and cuts off the latter microwave pulse. An X-band combination experiment is conducted with different pulse intervals. This experiment confirms that the high density plasma induced by the falling edge can cut off the latter pulse, and that the time required for plasma recombination in the transmission channel is several microseconds. To ensure a high output power for combined pulses, the latter pulse should be moved ahead of the falling edge of the former one, and consequently, a beat wave with high peak power becomes the output by adding two pulses with normal amplitudes.

Theory of edge radiation

Energy Technology Data Exchange (ETDEWEB)

Geloni, G.; Kocharyan, V.; Saldin, E.; Schneidmiller, E.; Yurkov, M.

2008-08-15

We formulate a complete theory of Edge Radiation based on a novel method relying on Fourier Optics techniques. Similar types of radiation like Transition UndulatorRadiation are addressed in the framework of the same formalism. Special attention is payed in discussing the validity of approximations upon which the theory is built. Our study makes consistent use of both similarity techniques and comparisons with numerical results from simulation. We discuss both near and far zone. Physical understanding of many asymptotes is discussed. Based on the solution of the field equation with a tensor Green's function technique, we also discuss an analytical model to describe the presence of a vacuum chamber. In particular, explicit calculations for a circular vacuum chamber are reported. Finally, we consider the use of Edge Radiation as a tool for electron beam diagnostics. We discuss Coherent Edge Radiation, Extraction of Edge Radiation by a mirror, and other issues becoming important at high electron energy and long radiation wavelength. Based on this work we also study the impact of Edge Radiation on XFEL setups and we discuss recent results. (orig.)

Critical edge parameters for H-mode transition in DIII-D

International Nuclear Information System (INIS)

Groebner, R.J.; Carlstrom, T.N.

1997-11-01

Measurements in DIII-D of edge ion and electron temperatures (T i and T e ) just prior to the transition to H-mode are presented. A fitting model based on a hyperbolic tangent function is used in the analysis. The edge temperatures are observed to increase during the L-phase with the application of auxiliary heating. The temperature rise is small if the H-mode power threshold is close to the Ohmic power level in the absence of auxiliary heating and is large if the H-mode threshold is well above the Ohmic power level. The edge temperatures just prior to the transition are approximately proportional to the toroidal magnetic field Bt for the field either in the reversed or forward direction. However, for the reversed magnetic field, the temperatures are at least a factor of two higher than for the forward direction

Edge effect on weevils and spiders

Directory of Open Access Journals (Sweden)

R. Horváth

2002-05-01

Full Text Available The edge effect on weevils and spiders was tested along oak forest – meadow transects using sweep-net samples at the Síkfökút Project in Hungary. For spiders the species richness was significantly higher in the forest edge than either in the meadow or the forest interior. For weevils the species richness of the forest edge was higher than that of the meadow, but the difference was not statistically significant whereas the species richness of the forest interior was significantly lower than that of the forest edge and the meadow. The composition of the spider assemblage of the edge was more similar to the forest, while the composition of weevils in the edge was more similar to the meadow. Our results based on two invertebrate groups operating on different trophic levels suggest that there is a significant edge effect for the studied taxa resulting in higher species richness in the edge.

Frequencies of the Edge-Magnetoplasmon Excitations in Gated Quantum Hall Edges

Science.gov (United States)

Endo, Akira; Koike, Keita; Katsumoto, Shingo; Iye, Yasuhiro

2018-06-01

We have investigated microwave transmission through the edge of quantum Hall systems by employing a coplanar waveguide (CPW) fabricated on the surface of a GaAs/AlGaAs two-dimensional electron gas (2DEG) wafer. An edge is introduced to the slot region of the CPW by applying a negative bias Vg to the central electrode (CE) and depleting the 2DEG below the CE. We observe peaks attributable to the excitation of edge magnetoplasmons (EMP) at a fundamental frequency f0 and at its harmonics if0 (i = 2,3, \\ldots ). The frequency f0 increases with decreasing Vg, indicating that EMP propagates with higher velocity for more negative Vg. The dependence of f0 on Vg is interpreted in terms of the variation in the distance between the edge state and the CE, which alters the velocity by varying the capacitive coupling between them. The peaks are observed to continue, albeit with less clarity, up to the regions of Vg where 2DEG still remains below the CE.

Edge magnetism impact on electrical conductance and thermoelectric properties of graphenelike nanoribbons

Science.gov (United States)

Krompiewski, Stefan; Cuniberti, Gianaurelio

2017-10-01

Edge states in narrow quasi-two-dimensional nanostructures determine, to a large extent, their electric, thermoelectric, and magnetic properties. Nonmagnetic edge states may quite often lead to topological-insulator-type behavior. However, another scenario develops when the zigzag edges are magnetic and the time reversal symmetry is broken. In this work we report on the electronic band structure modifications, electrical conductance, and thermoelectric properties of narrow zigzag nanoribbons with spontaneously magnetized edges. Theoretical studies based on the Kane-Mele-Hubbard tight-binding model show that for silicene, germanene, and stanene both the Seebeck coefficient and the thermoelectric power factor are strongly enhanced for energies close to the charge neutrality point. A perpendicular gate voltage lifts the spin degeneracy of energy bands in the ground state with antiparallel magnetized zigzag edges and makes the electrical conductance significantly spin polarized. Simultaneously the gate voltage worsens the thermoelectric performance. Estimated room-temperature figures of merit for the aforementioned nanoribbons can exceed a value of 3 if phonon thermal conductances are adequately reduced.

Studies of safety and critical work situations in nuclear power plants: A human factors perspective

International Nuclear Information System (INIS)

Jacobsson Kecklund, L.

1998-05-01

The purpose of this thesis was to develop and apply different approaches for analyzing safety in critical work situations in real work settings in nuclear power plants, and also to identify safety enhancing measures by using the framework of interaction between human, organizational and technical subsystems. A Cognitive Psychology as well as a Stress Psychology framework was used. All studies were related to the annual outage operational state where the need for coping with many infrequent tasks, often carried out under high time pressure, puts great strain on the staff and organisation of the plant. In three studies the natural variations in the plant state, normal operation and annual outage operation, were used to explore human performance, work-related factors as well as coping and the operators' own resources and the relationship between them. In the annual outage condition high work demands, decreased sleepiness at night shift, more errors and less satisfaction with work performance quality was reported by maintenance as well as by control room operators. A relationship between high work demands and more organizational problems and reports of more frequent human errors and lower satisfactions with work performance quality was also identified in the annual outage condition. Moreover, a relationship between increased sleepiness during night shift, more frequent use of coping strategies and a higher frequency of human errors was reported. In two studies the Event and Barrier Function Model was applied to analyze the safety of barrier function systems inserted into work process sequences to protect the systems from the negative consequences of failures and errors. The model was also used to assess safety in relation to a technical and organizational change. The last study addressed changes in work performance and work-related factors in relation to a technical and organizational change of a safety significant work process involving increased automation and new

Edge State Propagation Direction in the Fractional Quantum Hall Regime: Multi-Terminal Magnetocapacitance Experiment

International Nuclear Information System (INIS)

JOHNSON, B.L.; MOON, JEONG-SUN; RENO, JOHN L.; SIMMONS, JERRY A.

1999-01-01

The propagation direction of fractional quantum Hall effect (FQHE) edge states has been investigated experimentally via the symmetry properties of the multi-terminal capacitances of a two dimensional electron gas. Although strong asymmetries with respect to zero magnetic field appear, no asymmetries with respect to even denominator Landau level filling factor ν are seen. This indicates that current-carrying FQHE edge states propagate in the same direction as integer QHE edge states. In addition, anomalous capacitance features, indicative of enhanced bulk conduction, are observed at ν = 1/2 and 3/2

Human Factors Evaluation of Procedures for Periodic Safety Review of Yonggwang Unit no. 1, 2

Energy Technology Data Exchange (ETDEWEB)

Lee, Yong Hee; Lee, Jung Woon; Park, Jae Chang (and others)

2006-01-15

This report describes the results of human factors assessment on the plant operating procedures as part of Periodic Safety Review(PSR) of Yonggwang Nuclear Power Plant Unit no. 1, 2. The suitability of item and appropriateness of format and structure in the key operating procedures of nuclear power plants were investigated by the review of plant operating experiences and procedure documents, field survey, and experimental assessment on some part of procedures. A checklist was used to perform this assessment and record the review results. The reviewed procedures include EOP(Emergency Operating Procedures), GOP(General Operating Procedures), AOP(Abnormal Operating Procedures), and management procedures of some technical departments. As results of the assessments, any significant problem challenging the safety was not found on the human factors in the operating procedures. However, several small items to be changed and improved were discovered. An action plan is recommended to accommodate the suggestions and review comments. It will enhance the plant safety on the operating procedure.

Migration Factors in West African Immigrant Parents' Perceptions of Their Children's Neighborhood Safety.

Science.gov (United States)

Rasmussen, Andrew; Cissé, Aïcha; Han, Ying; Roubeni, Sonia

2018-02-12

Immigrants make up large proportions of many low-income neighborhoods, but have been largely ignored in the neighborhood safety literature. We examined perceived safety's association with migration using a six-item, child-specific measure of parents' perceptions of school-aged (5-12 years of age) children's safety in a sample of 93 West African immigrant parents in New York City. Aims of the study were (a) to identify pre-migration correlates (e.g., trauma in home countries), (b) to identify migration-related correlates (e.g., immigration status, time spent separated from children during migration), and (c) to identify pre-migration and migration correlates that accounted for variance after controlling for non-migration-related correlates (e.g., neighborhood crime, parents' psychological distress). In a linear regression model, children's safety was associated with borough of residence, greater English ability, less emotional distress, less parenting difficulty, and a history of child separation. Parents' and children's gender, parents' immigration status, and the number of contacts in the U.S. pre-migration and pre-migration trauma were not associated with children's safety. That child separation was positively associated with safety perceptions suggests that the processes that facilitate parent-child separation might be reconceptualized as strengths for transnational families. Integrating migration-related factors into the discussion of neighborhood safety for immigrant populations allows for more nuanced views of immigrant families' well-being in host countries. © Society for Community Research and Action 2018.

Predicted solar cell edge radiation effects

International Nuclear Information System (INIS)

Gates, M.T.

1993-01-01

The Advanced Solar Cell Orbital Test (ASCOT) will test six types of solar cells in a high energy proton environment. During the design of the experiment a question was raised about the effects of proton radiation incident on the edge of the solar cells and whether edge radiation shielding was required. Historical geosynchronous data indicated that edge radiation damage is not detectable over the normal end of life solar cell degradation; however because the ASCOT radiation environment has a much higher and more energetic fluence of protons, considerably more edge damage is expected. A computer analysis of the problem was made by modeling the expected radiation damage at the cell edge and using a network model of small interconnected solar cells to predict degradation in the cell's electrical output. The model indicated that the deepest penetration of edge radiation was at the top of the cell near the junction where the protons have access to the cell through the low density cell/cover adhesive layer. The network model indicated that the cells could tolerate high fluences at their edge as long as there was high electrical resistance between the edge radiated region and the contact system on top of the cell. The predicted edge radiation related loss was less than 2% of maximum power for GaAs/Ge solar cells. As a result, no edge radiation protection was used for ASCOT

Factors influencing safety in a sample of marked pedestrian crossings selected for safety inspections in the city of Oslo.

Science.gov (United States)

Elvik, Rune; Sørensen, Michael W J; Nævestad, Tor-Olav

2013-10-01

This paper reports an analysis of factors influencing safety in a sample of marked pedestrian crossings in the city of Oslo, Norway. The sample consists of 159 marked pedestrian crossings where a total of 316 accidents were recorded during a period of five years. The crossings were selected for inspection because of they were, for various reasons, regarded as sub-standard. The sample of crossings is therefore not representative of all pedestrian crossings in Oslo. Factors influencing the number of accidents were studied by means of negative binomial regression. Factors that were studied included the volume of pedestrians and vehicles, the number of traffic lanes at the crossing, the location of the crossing (midblock or junction), the type of traffic control, the share of pedestrians using the crossing and the speed of approaching vehicles. The analysis confirmed the presence of a "safety-in-numbers" effect, meaning that an increase in the number of pedestrians is associated with a lower risk of accident for each pedestrian. Crossings located in four-leg junctions or roundabouts had more accidents than crossings located in three-leg junctions or on sections between junctions. A high share of pedestrians crossing the road outside the marked crossing was associated with a high number of accidents. Increased speed was associated with an increased number of accidents. Copyright © 2013 Elsevier Ltd. All rights reserved.

On the physics of the pressure and temperature gradients in the edge of tokamak plasmas

Science.gov (United States)

Stacey, Weston M.

2018-04-01

An extended plasma fluid theory including atomic physics, radiation, electromagnetic and themodynamic forces, external sources of particles, momentum and energy, and kinetic ion orbit loss is employed to derive theoretical expressions that display the role of the various factors involved in the determination of the pressure and temperature gradients in the edge of tokamak plasmas. Calculations for current experiments are presented to illustrate the magnitudes of various effects including strong radiative and atomic physics edge cooling effects and strong reduction in ion particle and energy fluxes due to ion orbit loss in the plasma edge. An important new insight is the strong relation between rotation and the edge pressure gradient.

Safety climate and self-reported injury: assessing the mediating role of employee safety control.

Science.gov (United States)

Huang, Yueng-Hsiang; Ho, Michael; Smith, Gordon S; Chen, Peter Y

2006-05-01

To further reduce injuries in the workplace, companies have begun focusing on organizational factors which may contribute to workplace safety. Safety climate is an organizational factor commonly cited as a predictor of injury occurrence. Characterized by the shared perceptions of employees, safety climate can be viewed as a snapshot of the prevailing state of safety in the organization at a discrete point in time. However, few studies have elaborated plausible mechanisms through which safety climate likely influences injury occurrence. A mediating model is proposed to link safety climate (i.e., management commitment to safety, return-to-work policies, post-injury administration, and safety training) with self-reported injury through employees' perceived control on safety. Factorial evidence substantiated that management commitment to safety, return-to-work policies, post-injury administration, and safety training are important dimensions of safety climate. In addition, the data support that safety climate is a critical factor predicting the history of a self-reported occupational injury, and that employee safety control mediates the relationship between safety climate and occupational injury. These findings highlight the importance of incorporating organizational factors and workers' characteristics in efforts to improve organizational safety performance.

The visibility of IQHE at sharp edges: experimental proposals based on interactions and edge electrostatics

International Nuclear Information System (INIS)

Erkarslan, U; Oylumluoglu, G; Grayson, M; Siddiki, A

2012-01-01

The influence of the incompressible strips on the integer quantized Hall effect (IQHE) is investigated, considering a cleaved-edge overgrown (CEO) sample as an experimentally realizable sharp edge system. We propose a set of experiments to clarify the distinction between the large-sample limit when bulk disorder defines the IQHE plateau width and the small-sample limit smaller than the disorder correlation length, when self-consistent edge electrostatics define the IQHE plateau width. The large-sample or bulk quantized Hall (QH) regime is described by the usual localization picture, whereas the small-sample or edge regime is discussed within the compressible/incompressible strips picture, known as the screening theory of QH edges. Utilizing the unusually sharp edge profiles of the CEO samples, a Hall bar design is proposed to manipulate the edge potential profile from smooth to extremely sharp. By making use of a side-gate perpendicular to the two-dimensional electron system, it is shown that the plateau widths can be changed or even eliminated altogether. Hence, the visibility of IQHE is strongly influenced when adjusting the edge potential profile and/or changing the dc current direction under high currents in the nonlinear transport regime. As a second investigation, we consider two different types of ohmic contacts, namely highly transmitting (ideal) and highly reflecting (non-ideal) contacts. We show that if the injection contacts are non-ideal, but still ohmic, it is possible to measure directly the non-quantized transport taking place at the bulk of the CEO samples. The results of the experiments we propose will clarify the influence of the edge potential profile and the quality of the contacts, under QH conditions. (paper)

Establishment and prioritization of relevant factors to the safety of fuel cycle facilities non reactor through dynamics archetypes evaluation

International Nuclear Information System (INIS)

Sousa, Anna Leticia Barbosa de

2012-01-01

The present work aims to establish and prioritize factors that are important to the safety of nuclear fuel cycle facilities in order to model, analyze and design safety as a physical system, employing systemic models in an innovative way. This work takes into consideration the fact that models that use adaptations of methodologies for nuclear reactors will not properly work due to the specificities of fuel cycle facilities. Based on the fundamentals of the theory of systems, the four levels of system thinking, and the relationship of eight socio technical factors, a mental model has been developed for safety management in the nuclear fuel cycle context. From this conceptual model, safety archetypes were constructed in order to identify and highlight the processes of change and decision making that allow the system to migrate to a state of loss of safety. After that, stock and flow diagrams were created so that their behavior could be assessed by the system's dynamics. The results from the analysis using the model that simulates the dynamic behavior of the variables (socio technical factors) indicated, as expected, that the system's dynamics proved to be an appropriate and efficient tool for modeling fuel cycle safety as an emergent property. (author)

Modification of tokamak edge turbulence using feedback

International Nuclear Information System (INIS)

Richards, B.; Uckan, T.; Wootton, A.J.; Carreras, B.A.; Bengtson, R.D.; Hurwitz, P.; Li, G.X.; Lin, H.; Rowan, W.L.; Tsui, H.Y.W.; Sen, A.K.; Uglum, J.

1994-01-01

Using active feedback, the turbulent fluctuation levels have been reduced by as much as a factor of 2 in the edge of the Texas Experimental Tokamak (TEXT) [K. W. Gentle, Nucl. Fusion Technol. 1, 479 (1981)]. A probe system was used to drive a suppressor wave in the TEXT limiter shadow. A decrease in the local turbulence-induced particle flux has been seen, but a global change in the particle transport at the present time has not been observed. By changing the phase shift and gain of the feedback network, the amplitude of the turbulence was increased by a factor of 10

Measuring Safety Culture on Ships Using Safety Climate: A Study among Indian Officers

Directory of Open Access Journals (Sweden)

Yogendra Bhattacharya

2015-12-01

Full Text Available Workplace safety continues to be an area of concern in the maritime industry due to the international nature of the operations. The effectiveness of extensive legislation to manage shipboard safety remains in doubt. The focus must therefore shift towards the human element - seafarers and their perceptions of safety. The study aims to understand the alignment that exists between safety culture and safety climate on board ships as perceived by seafarers. The underlying factors of safety climate were identified using factor analysis which isolated seven factors - Support on Safety, Organizational Support, Resource Availability, Work Environment, Job Demands, ‘Just’ Culture, and Safety Compliance. The perception of safety level of seafarers was found to be low indicating the existence of misalignments between safety culture values and the actual safety climate. The study also reveals that the safety perceptions of officers employed directly by ship owners and those by managers do not differ significantly, nor do they differ between senior and junior officers. A shift in perspective towards how seafarers themselves feel towards safety might provide more effective solutions – instead of relying on regulations - and indeed aid in reducing incidents on board. This paper details practical suggestions on how to identify the factors that contribute towards a better safety climate on board ships.

Infrastructural and Human Factors Affecting Safety Outcomes of Cyclists

Directory of Open Access Journals (Sweden)

Sergio Useche

2018-01-01

Full Text Available The increasing number of registered road crashes involving cyclists during the last decade and the high proportion of road crashes resulting in severe injuries and fatalities among cyclists constitutes a global issue for community health, urban development and sustainability. Nowadays, the incidence of many risk factors for road crashes of cyclists remains largely unexplained. Given the importance of this issue, the present study has been conducted with the aim of determining relationships between infrastructural, human factors and safety outcomes of cyclists. Objectives: This study aimed, first, to examine the relationship between key infrastructural and human factors present in cycling, bicycle-user characteristics and their self-reported experience with road crashes. And second, to determine whether a set of key infrastructural and human factors may predict their self-reported road crashes. Methods: For this cross-sectional study, a total of 1064 cyclists (38.8% women, 61.2% men; M = 32.8 years of age from 20 different countries across Europe, South America and North America, participated in an online survey composed of four sections: demographic data and cycling-related factors, human factors, perceptions on infrastructural factors and road crashes suffered. Results: The results of this study showed significant associations between human factors, infrastructural conditions and self-reported road crashes. Also, a logistic regression model found that self-reported road crashes of cyclists could be predicted through variables such as age, riding intensity, risky behaviours and problematic user/infrastructure interactions. Conclusions: The results of this study suggest that self-reported road crashes of cyclists are influenced by features related to the user and their interaction with infrastructural characteristics of the road.

Edge control in CNC polishing, paper 2: simulation and validation of tool influence functions on edges.

Science.gov (United States)

Li, Hongyu; Walker, David; Yu, Guoyu; Sayle, Andrew; Messelink, Wilhelmus; Evans, Rob; Beaucamp, Anthony

2013-01-14

Edge mis-figure is regarded as one of the most difficult technical issues for manufacturing the segments of extremely large telescopes, which can dominate key aspects of performance. A novel edge-control technique has been developed, based on 'Precessions' polishing technique and for which accurate and stable edge tool influence functions (TIFs) are crucial. In the first paper in this series [D. Walker Opt. Express 20, 19787-19798 (2012)], multiple parameters were experimentally optimized using an extended set of experiments. The first purpose of this new work is to 'short circuit' this procedure through modeling. This also gives the prospect of optimizing local (as distinct from global) polishing for edge mis-figure, now under separate development. This paper presents a model that can predict edge TIFs based on surface-speed profiles and pressure distributions over the polishing spot at the edge of the part, the latter calculated by finite element analysis and verified by direct force measurement. This paper also presents a hybrid-measurement method for edge TIFs to verify the simulation results. Experimental and simulation results show good agreement.

Acyclicity in edge-colored graphs

DEFF Research Database (Denmark)

Gutin, Gregory; Jones, Mark; Sheng, Bin

2017-01-01

A walk W in edge-colored graphs is called properly colored (PC) if every pair of consecutive edges in W is of different color. We introduce and study five types of PC acyclicity in edge-colored graphs such that graphs of PC acyclicity of type i is a proper superset of graphs of acyclicity of type...

Protected Pseudohelical Edge States in Z2-Trivial Proximitized Graphene

Science.gov (United States)

Frank, Tobias; Högl, Petra; Gmitra, Martin; Kochan, Denis; Fabian, Jaroslav

2018-04-01

We investigate topological properties of models that describe graphene on realistic substrates which induce proximity spin-orbit coupling in graphene. A Z2 phase diagram is calculated for the parameter space of (generally different) intrinsic spin-orbit coupling on the two graphene sublattices, in the presence of Rashba coupling. The most fascinating case is that of staggered intrinsic spin-orbit coupling which, despite being topologically trivial, Z2=0 , does exhibit edge states protected by time-reversal symmetry for zigzag ribbons as wide as micrometers. We call these states pseudohelical as their helicity is locked to the sublattice. The spin character and robustness of the pseudohelical modes is best exhibited on a finite flake, which shows that the edge states have zero g factor, carry a pure spin current in the cross section of the flake, and exhibit spin-flip reflectionless tunneling at the armchair edges.

Safety factor profile control in a tokamak

CERN Document Server

Bribiesca Argomedo, Federico; Prieur, Christophe

2014-01-01

Control of the Safety Factor Profile in a Tokamak uses Lyapunov techniques to address a challenging problem for which even the simplest physically relevant models are represented by nonlinear, time-dependent, partial differential equations (PDEs). This is because of the  spatiotemporal dynamics of transport phenomena (magnetic flux, heat, densities, etc.) in the anisotropic plasma medium. Robustness considerations are ubiquitous in the analysis and control design since direct measurements on the magnetic flux are impossible (its estimation relies on virtual sensors) and large uncertainties remain in the coupling between the plasma particles and the radio-frequency waves (distributed inputs). The Brief begins with a presentation of the reference dynamical model and continues by developing a Lyapunov function for the discretized system (in a polytopic linear-parameter-varying formulation). The limitations of this finite-dimensional approach motivate new developments in the infinite-dimensional framework. The t...

Balancing the edge effects budget: bay scallop settlement and loss along a seagrass edge.

Science.gov (United States)

Carroll, John M; Furman, Bradley T; Tettelbach, Stephen T; Peterson, Bradley J

2012-07-01

Edge effects are a dominant subject in landscape ecology literature, yet they are highly variable and poorly understood. Often, the literature suggests simple models for edge effects-positive (enhancement at the edge), negative (enhancement at the interior), or no effect (neutral)--on a variety of metrics, including abundance, diversity, and mortality. In the marine realm, much of this work has focused on fragmented seagrass habitats due to their importance for a variety of commercially important species. In this study, the settlement, recruitment, and survival of bay scallops was investigated across a variety of seagrass patch treatments. By simultaneously collecting settlers (those viable larvae available to settle and metamorphose) and recruits (those settlers that survive some period of time, in this case, 6 weeks) on the same collectors, we were able to demonstrate a "balance" between positive and negative edge effects, resulting in a net neutral effect. Scallop settlement was significantly enhanced along seagrass edges, regardless of patch type while survival was elevated within patch interiors. However, recruitment (the net result of settlement and post-settlement loss) did not vary significantly from edge to center, representing a neutral effect. Further, results suggest that post-settlement loss, most likely due to predation, appears to be the dominant mechanism structuring scallop abundance, not patterns in settlement. These data illustrate the complexity of edge effects, and suggest that the metric used to investigate the effect (be it abundance, survival, or other metrics) can often influence the magnitude and direction of the perceived effect. Traditionally, high predation along a habitat edge would have indicated an "ecological trap" for the species in question; however, this study demonstrates that, at the population level, an ecological trap may not exist.

NRC Information No. 90-18: Potential problems with Crosby safety relief valves used on diesel generator air start receiver tanks

International Nuclear Information System (INIS)

Rossi, C.E.

1992-01-01

On March 31, 1989, Cooper Industries was made aware of circumstances at Perry Unit 1 that led to the Division I EDG being declared inoperable. A Crosby safety relief valve on one of the two EDG starting air receiving tanks was inadvertently hit during maintenance activities. The force of the impact caused the valve to open and blow down both air receiving tanks. The safety relief valve did not reseat until approximately 30 psig below the EDG automatic start lockout signal. On January 12, 1990, Cooper Industries learned that a similar event had occurred at Comanche Peak. On January 17, 1990, Cooper Industries submitted a 10 CFR Part 21 report on the affected safety relief valves (Crosby style JMBU and JRU safety relief valves). Although Crosby-style JMBU and JRU safety relief valves were designed to meet the requirements of Section VIII of the ASME Boiler and Pressure Vessel Code, they were not seismically qualified. In addition, the blowdown characteristics of the valves were not consistent with the functional requirements of the system in which they were installed. Cooper Industries has recommended replacing these valves with seismically qualified valves that have the proper blowdown reseat characteristics

Detailed tabulation of atomic form factors, photoelectric absorption and scattering cross section, and mass attenuation coefficients in the vicinity of absorption edges in the soft X-ray (Z=30-36, Z=60-89, E=0.1 keV-10 keV), addressing convergence issues of earlier work

International Nuclear Information System (INIS)

Chantler, C.T.

2000-01-01

Reliable knowledge of the complex x-ray form factor [Re(f ) ] and the photoelectric attenuation coefficient (σ PE ) is required for crystallography, medical diagnosis, radiation safety, and XAFS studies. Discrepancies between currently used theoretical approaches of 200% exist for numerous elements from 1 to 3 keV x-ray energies. The key discrepancies are due to the smoothing of edge structure, the use of nonrelativistic wave functions, and the lack of appropriate convergence of wave functions. This paper addresses these key discrepancies and derives new theoretical results of substantially higher accuracy in near-edge soft x-ray regions. The high-energy limitations of the current approach are also illustrated. The energy range covered is 0.1 to 10 keV. The associated figures and tabulation demonstrate the current comparison with alternate theory and with available experimental data. In general, experimental data are not sufficiently accurate to establish the errors and inadequacies of theory at this level. However, the best experimental data and the observed experimental structure as a function of energy are strong indicators of the validity of the current approach. New developments in experimental measurement hold great promise in making critical comparisons with theory in the near future

Investigation of occupational health and safety application using the internal and external factor assessment matrix: SWOT

Directory of Open Access Journals (Sweden)

2012-09-01

Material and Method: IIn this study, the threats, opportunities, weaknesses and strengths were evaluated by one of the tools named SWOT, in one of the assembly industries company in Iran, in order to controlling the operations in this company considering to safety and health standard (OHSAS18001. A comparison of the company’s performance in implementing the safety and health standards was done between years 1387 and 1388 contain in the Company considered, and weighted scoring weaknesses, strengths, threats and opportunities using the matrix of internal factors (strengths and weaknesses and external factors (treats and opportunities then, the importance of each factor were determined in the company’s implementation and enforcement of those standards. . Result: Focusing on the strengths and weaknesses, opportunities and threats, some strategies to improve the implementation were presented. Any points were weighted based on the most important weaknesses identified as the lack of monitoring contractors, lack of management commitment for implementation of OHSAS18001, no attempt to identify the risks of change, lack of training needs assessment, main strengths identified in the context of adequate budget health and safety, environmental efforts, identify risk for abnormal conditions, the most important threats for immediate delivery customer orders and the opportunity to support the safety and health plans, were determined. . Conclusion: Sum of the weighted scores in year 87 were obtained for the external factors (opportunities and threats, 2.16 and internal factors (strengths and weaknesses 1.66. Both of these scores were less than 2.5 (minimum amount of the acceptable rate so, the company has been poor performance in the implementation of this standard for the year 87 and a weak reaction in the use of opportunities and the minimize threats has. In case of internal factors, it was worse than external one and the situation was more bold of the weaknesses companies to

Edge localized modes and edge pedestal in NBI and ICRF heated H, D and T-plasmas in JET

International Nuclear Information System (INIS)

Bhatnagar, V.; Lingertat, J.; Barnsley, R.

1998-12-01

Based on experiments carried out in JET in D:T mixtures varying from 100:0 to 5:95 and those carried out in hydrogen plasmas, the isotopic mass dependence of ELM parameters and the edge pedestal pressure in neutral beam (NBI) and ion cyclotron resonance (ICRF) heated H-mode plasmas is presented. The ELM frequency is found to decrease with the atomic mass number both in ICRH and NBI discharges. However, the frequency in the case of ICRH is about 8 - 10 times higher than in the NBI case. Assuming that ELMs occur at a critical edge pressure gradient, limited by the ballooning instability, the scaling of the maximum edge pressure is most consistent with the assumption that the width of the transport barrier scales as the ion poloidal Larmor radius governed by the average energy of fast ions at the edge. The critical edge pressure in NBI heated discharges increases with the isotopic mass which. is consistent with the higher deduced width of the edge transport, barrier in tritium than in deuterium and hydrogen. The critical edge pressure in ICRH discharges is smaller, presumably, due to the smaller fast-ion contribution to the edge region. As a consequence of the edge pressure scaling with isotopic mass, the edge operational space in the n e - T e diagram increases with operation in tritium. If the evidence that the edge pedestal width is governed by the average energy of fast ions in the edge prevails, the pedestal in ITER would be controlled by the slowing down energy spectrum of α-particles in the edge. (author)

Nuclear Safety Review 2013

Energy Technology Data Exchange (ETDEWEB)

NONE

2013-07-15

The Nuclear Safety Review 2013 focuses on the dominant nuclear safety trends, issues and challenges in 2012. The Executive Overview provides crosscutting and worldwide nuclear safety information along with a summary of the major sections covered in this report. Sections A-E of this report cover improving radiation, transport and waste safety; strengthening safety in nuclear installations; improving regulatory infrastructure and effectiveness; enhancing emergency preparedness and response (EPR); and civil liability for nuclear damage. The Appendix provides details on the activities of the Commission on Safety Standards (CSS), and activities relevant to the IAEA Safety Standards. The world nuclear community has made noteworthy progress in strengthening nuclear safety in 2012, as promoted by the IAEA Action Plan on Nuclear Safety (hereinafter referred to as ''the Action Plan''). For example, an overwhelming majority of Member States with operating nuclear power plants (NPPs) have undertaken and essentially completed comprehensive safety reassessments ('stress tests') with the aim of evaluating the design and safety aspects of plant robustness to protect against extreme events, including: defence in depth, safety margins, cliff edge effects, multiple failures, and the prolonged loss of support systems. As a result, many have introduced additional safety measures including mitigation of station blackout. Moreover, the IAEA's peer review services and safety standards have been reviewed and strengthened where needed. Capacity building programmes have been built or improved, and EPR programmes have also been reviewed and improved. Furthermore, in 2012, the IAEA continued to share lessons learned from the Fukushima Daiichi accident with the nuclear community including through three international experts' meetings (IEMs) on reactor and spent fuel safety, communication in the event of a nuclear or radiological emergency, and protection against extreme earthquakes and tsunamis.

Nuclear Safety Review 2013

International Nuclear Information System (INIS)

2013-07-01

The Nuclear Safety Review 2013 focuses on the dominant nuclear safety trends, issues and challenges in 2012. The Executive Overview provides crosscutting and worldwide nuclear safety information along with a summary of the major sections covered in this report. Sections A-E of this report cover improving radiation, transport and waste safety; strengthening safety in nuclear installations; improving regulatory infrastructure and effectiveness; enhancing emergency preparedness and response (EPR); and civil liability for nuclear damage. The Appendix provides details on the activities of the Commission on Safety Standards (CSS), and activities relevant to the IAEA Safety Standards. The world nuclear community has made noteworthy progress in strengthening nuclear safety in 2012, as promoted by the IAEA Action Plan on Nuclear Safety (hereinafter referred to as ''the Action Plan''). For example, an overwhelming majority of Member States with operating nuclear power plants (NPPs) have undertaken and essentially completed comprehensive safety reassessments ('stress tests') with the aim of evaluating the design and safety aspects of plant robustness to protect against extreme events, including: defence in depth, safety margins, cliff edge effects, multiple failures, and the prolonged loss of support systems. As a result, many have introduced additional safety measures including mitigation of station blackout. Moreover, the IAEA's peer review services and safety standards have been reviewed and strengthened where needed. Capacity building programmes have been built or improved, and EPR programmes have also been reviewed and improved. Furthermore, in 2012, the IAEA continued to share lessons learned from the Fukushima Daiichi accident with the nuclear community including through three international experts' meetings (IEMs) on reactor and spent fuel safety, communication in the event of a nuclear or radiological emergency, and protection against extreme earthquakes and tsunamis

An Analysis of Trainers' Perspectives within an Ecological Framework: Factors that Influence Mine Safety Training Processes.

Science.gov (United States)

Haas, Emily J; Hoebbel, Cassandra L; Rost, Kristen A

2014-09-01

Satisfactory completion of mine safety training is a prerequisite for being hired and for continued employment in the coal industry. Although training includes content to develop skills in a variety of mineworker competencies, research and recommendations continue to specify that specific limitations in the self-escape portion of training still exist and that mineworkers need to be better prepared to respond to emergencies that could occur in their mine. Ecological models are often used to inform the development of health promotion programs but have not been widely applied to occupational health and safety training programs. Nine mine safety trainers participated in in-depth semi-structured interviews. A theoretical analysis of the interviews was completed via an ecological lens. Each level of the social ecological model was used to examine factors that could be addressed both during and after mine safety training. The analysis suggests that problems surrounding communication and collaboration, leadership development, and responsibility and accountability at different levels within the mining industry contribute to deficiencies in mineworkers' mastery and maintenance of skills. This study offers a new technique to identify limitations in safety training systems and processes. The analysis suggests that training should be developed and disseminated with consideration of various levels-individual, interpersonal, organizational, and community-to promote skills. If factors identified within and between levels are addressed, it may be easier to sustain mineworker competencies that are established during safety training.

Does the edge effect influence plant community structure in a tropical dry forest?

Directory of Open Access Journals (Sweden)

Diogo Gallo Oliveira

2013-04-01

Full Text Available Edge effects are considered a key factor in regulating the structure of plant communities in different ecosystems. However, regardless to few studies, edge influence does not seem to be decisive in semiarid regions such as the Brazilian tropical dry forest known as Caatinga but this issue remains inconclusive. The present study tests the null hypothesis that the plant community of shrubs and trees does not change in its structure due to edge effects. Twenty-four plots (20 x 20 m were set up in a fragment of Caatinga, in which 12 plots were in the forest edges and 12 plots were inside the fragment. Tree richness, abundance and species composition did not differ between edge and interior plots. The results of this study are in agreement with the pattern previously found for semiarid environments and contrasts with previous results obtained in different environments such as Rainforests, Savanna and Forest of Araucaria, which indicate abrupt differences between the border and interior of the plant communities in these ecosystems, and suggest that the community of woody plants of the Caatinga is not ecologically affected by the presence of edges.

Effect of interaction strength on robustness of controlling edge dynamics in complex networks

Science.gov (United States)

Pang, Shao-Peng; Hao, Fei

2018-05-01

Robustness plays a critical role in the controllability of complex networks to withstand failures and perturbations. Recent advances in the edge controllability show that the interaction strength among edges plays a more important role than network structure. Therefore, we focus on the effect of interaction strength on the robustness of edge controllability. Using three categories of all edges to quantify the robustness, we develop a universal framework to evaluate and analyze the robustness in complex networks with arbitrary structures and interaction strengths. Applying our framework to a large number of model and real-world networks, we find that the interaction strength is a dominant factor for the robustness in undirected networks. Meanwhile, the strongest robustness and the optimal edge controllability in undirected networks can be achieved simultaneously. Different from the case of undirected networks, the robustness in directed networks is determined jointly by the interaction strength and the network's degree distribution. Moreover, a stronger robustness is usually associated with a larger number of driver nodes required to maintain full control in directed networks. This prompts us to provide an optimization method by adjusting the interaction strength to optimize the robustness of edge controllability.

Safety and Efficacy of BAY 94-9027, a Prolonged-Half-Life Factor VIII

DEFF Research Database (Denmark)

Reding, M T; Ng, H J; Poulsen, Lone Hvitfeldt

2017-01-01

BACKGROUND: BAY 94-9027 is a B-domain-deleted prolonged-half-life recombinant factor VIII (FVIII) conjugates in a site-specific manner with polyethylene glycol. OBJECTIVE: Assess efficacy and safety of BAY 94-9027 for prophylaxis and treatment of bleeds in patients with severe hemophilia A PATIEN...

Safety assessment of human and organizational factors in French fuel cycle facilities

International Nuclear Information System (INIS)

Menuet, Lise; Beauquier, Sophie

2013-01-01

According to the French law, each nuclear facility has to provide a safety demonstration every ten years. The assessment of this demonstration supports the decision of the French Safety Authority regarding the authorisation of operating for the ten years to come. In addition, transversal topics, which are linked with safety performance, such as safety management, management of competencies, maintenance's policy are periodically evaluated. One aspect of these assessments relates to Human and Organizational Factors (HOF) and their contribution to safety. Our communication will describe the assessment of the HOF-related part, performed by the Institute for Radioprotection and Nuclear Safety Institute (IRSN) the Technical Support Organisation of the French Safety Authority). It will focus on the methodological framework, the tools which are developed and used for assessing the integration of HOF in safety demonstration, and the main difficulties of this kind of assessment. Each situation will be illustrated by concrete examples coming from safety assessments concerning fuel cycle's plants: Areva's plants dedicated to uranium conversion, uranium enrichment, fuel manufacturing, spent fuel reprocessing, treatment facilities and CEA's laboratories dedicated to research and development and to interim spent fuel storage. The methodological framework for assessing HOF currently implements three main steps which will be precisely described: - checking that the nuclear plant has made an exhaustive analysis of the risks linked with HOF. Regarding to HOF, the Licensee safety demonstration is based on the description of the main human activities which are considered as hazardous regarding safety. These activities are accomplished with a human contribution and they require a safe realisation. - assessing the human, organisational and technical barriers that the nuclear plant have planed in order to make the operations safe, to avoid, prevent or detect an

Calibration of partial safety factors for wind turbine rotor blades against fatigue failure; Kalibrering af partielle sikkerhedsfaktorer for udmattelse af vindmoellerotorer

Energy Technology Data Exchange (ETDEWEB)

Christensen, C.J.; Ronold, K.O.; Thoegersen, M.L.

2000-08-01

The report describes a calibration of partial safety factors for wind turbine rotor blades subjected to fatigue loading in flapwise and edgewise bending. While earlier models - developed by the authors - dealt with such calibrations for site-specific individual turbines only, the calibration model applied herein covers an integrated analysis with different turbines on different sites and with different blade materials. The result is an optimized set of partial safety factors, i.e. a set of safety factors that lead to minimum deviation from the target reliability of the achieved reliabilities over the selected scope of turbines, sites and materials. The turbines included in the study cover rated powers of 450-600 kW. The result from the calibration are discussed in relation to the partial safety factors that are given in the Danish codes for design of glass fibre reinforced rotor blades (DS472 and DS456). (au)

77 FR 26647 - National Building Safety Month, 2012

Science.gov (United States)

2012-05-04

... implementing state-of-the-art building safety, energy efficiency, and fire prevention codes and standards, they... our Nation's ability to withstand the threats and hazards we face. My Administration is committed to... disasters. We are drawing upon cutting edge science and technology to establish stronger codes and standards...

Gate-controlled tunneling of quantum Hall edge states in bilayer graphene

Science.gov (United States)

Zhu, Jun; Li, Jing; Wen, Hua

Controlled tunneling of integer and fractional quantum Hall edge states provides a powerful tool to probe the physics of 1D systems and exotic particle statistics. Experiments in GaAs 2DEGs employ either a quantum point contact or a line junction tunnel barrier. It is generally difficult to independently control the filling factors νL and νR on the two sides of the barrier. Here we show that in bilayer graphene both νL and νR as well as their Landau level structures can be independently controlled using a dual-split-gate structure. In addition, the height of the line-junction tunnel barrier implemented in our experiments is tunable via a 5th gate. By measuring the tunneling resistance across the junction RT we examine the equilibration of the edge states in a variety of νL/νR scenarios and under different barrier heights. Edge states from both sides are fully mixed in the case of a low barrier. As the barrier height increases, we observe plateaus in RT that correspond to sequential complete backscattering of edge states. Gate-controlled manipulation of edge states offers a new angle to the exploration of quantum Hall magnetism and fractional quantum Hall effect in bilayer graphene.

An Analysis of Trainers' Perspectives within an Ecological Framework: Factors that Influence Mine Safety Training Processes

Directory of Open Access Journals (Sweden)

Emily J. Haas

2014-09-01

Conclusion: This study offers a new technique to identify limitations in safety training systems and processes. The analysis suggests that training should be developed and disseminated with consideration of various levels—individual, interpersonal, organizational, and community—to promote skills. If factors identified within and between levels are addressed, it may be easier to sustain mineworker competencies that are established during safety training.

Multilevel Safety Climate and Safety Performance in the Construction Industry: Development and Validation of a Top-Down Mechanism

Directory of Open Access Journals (Sweden)

Ran Gao

2016-11-01

Full Text Available The character of construction projects exposes front-line workers to dangers and accidents. Safety climate has been confirmed to be a predictor of safety performance in the construction industry. This study aims to explore the underlying mechanisms of the relationship between multilevel safety climate and safety performance. An integrated model was developed to study how particular safety climate factors of one level affect those of other levels, and then affect safety performance from the top down. A questionnaire survey was administered on six construction sites in Vietnam. A total of 1030 valid questionnaires were collected from this survey. Approximately half of the data were used to conduct exploratory factor analysis (EFA and the remaining data were submitted to structural equation modeling (SEM. Top management commitment (TMC and supervisors’ expectation (SE were identified as factors to represent organizational safety climate (OSC and supervisor safety climate (SSC, respectively, and coworkers’ caring and communication (CCC and coworkers’ role models (CRM were identified as factors to denote coworker safety climate (CSC. SEM results show that OSC factor is positively related to SSC factor and CSC factors significantly. SSC factor could partially mediate the relationship between OSC factor and CSC factors, as well as the relationship between OSC factor and safety performance. CSC factors partially mediate the relationship between OSC factor and safety performance, and the relationship between SSC factor and safety performance. The findings imply that a positive safety culture should be established both at the organizational level and the group level. Efforts from all top management, supervisors, and coworkers should be provided to improve safety performance in the construction industry.

Multilevel Safety Climate and Safety Performance in the Construction Industry: Development and Validation of a Top-Down Mechanism.

Science.gov (United States)

Gao, Ran; Chan, Albert P C; Utama, Wahyudi P; Zahoor, Hafiz

2016-11-08

The character of construction projects exposes front-line workers to dangers and accidents. Safety climate has been confirmed to be a predictor of safety performance in the construction industry. This study aims to explore the underlying mechanisms of the relationship between multilevel safety climate and safety performance. An integrated model was developed to study how particular safety climate factors of one level affect those of other levels, and then affect safety performance from the top down. A questionnaire survey was administered on six construction sites in Vietnam. A total of 1030 valid questionnaires were collected from this survey. Approximately half of the data were used to conduct exploratory factor analysis (EFA) and the remaining data were submitted to structural equation modeling (SEM). Top management commitment (TMC) and supervisors' expectation (SE) were identified as factors to represent organizational safety climate (OSC) and supervisor safety climate (SSC), respectively, and coworkers' caring and communication (CCC) and coworkers' role models (CRM) were identified as factors to denote coworker safety climate (CSC). SEM results show that OSC factor is positively related to SSC factor and CSC factors significantly. SSC factor could partially mediate the relationship between OSC factor and CSC factors, as well as the relationship between OSC factor and safety performance. CSC factors partially mediate the relationship between OSC factor and safety performance, and the relationship between SSC factor and safety performance. The findings imply that a positive safety culture should be established both at the organizational level and the group level. Efforts from all top management, supervisors, and coworkers should be provided to improve safety performance in the construction industry.

Improving the opto-microwave performance of SiGe/Si phototransistor through edge-illuminated structure

Science.gov (United States)

Tegegne, Z. G.; Viana, C.; Polleux, J. L.; Grzeskowiak, M.; Richalot, E.

2016-03-01

This paper demonstrates the experimental study of edge and top illuminated SiGe phototransistors (HPT) implemented using the existing industrial SiGe2RF Telefunken GmbH BiCMOS technology for opto-microwave (OM) applications using 850nm Multi-Mode Fibers (MMF). Its technology and structure are described. Two different optical window size HPTs with top illumination (5x5μm2, 10x10μm2) and an edge illuminated HPTs having 5μm x5μm size are presented and compared. A two-step post fabrication process was used to create an optical access on the edge of the HPT for lateral illumination with a lensed MMF through simple polishing and dicing techniques. We perform Opto-microwave Scanning Near-field Optical Microscopy (OM-SNOM) analysis on edge and top illuminated HPTs in order to observe the fastest and the highest sensitive regions of the HPTs. This analysis also allows understanding the parasitic effect from the substrate, and thus draws a conclusion on the design aspect of SiGe/Si HPT. A low frequency OM responsivity of 0.45A/W and a cutoff frequency, f-3dB, of 890MHz were measured for edge illuminated HPT. Compared to the top illuminated HPT of the same size, the edge illuminated HPT improves the f-3dB by a factor of more than two and also improves the low frequency responsivity by a factor of more than four. These results demonstrate that a simple etched HPT is still enough to achieve performance improvements compared to the top illuminated HPT without requiring a complex coupling structure. Indeed, it also proves the potential of edge coupled SiGe HPT in the ultra-low-cost silicon based optoelectronics circuits with a new approach of the optical packaging and system integration to 850nm MMF.

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.

Magnetohydrodynamic stability of tokamak edge plasmas

International Nuclear Information System (INIS)

Connor, J.W.; Hastie, R.J.; Wilson, H.R.; Miller, R.L.

1998-01-01

A new formalism for analyzing the magnetohydrodynamic stability of a limiter tokamak edge plasma is developed. Two radially localized, high toroidal mode number n instabilities are studied in detail: a peeling mode and an edge ballooning mode. The peeling mode, driven by edge current density and stabilized by edge pressure gradient, has features which are consistent with several properties of tokamak behavior in the high confinement open-quotes Hclose quotes-mode of operation, and edge localized modes (or ELMs) in particular. The edge ballooning mode, driven by the pressure gradient, is identified; this penetrates ∼n 1/3 rational surfaces into the plasma (rather than ∼n 1/2 , expected from conventional ballooning mode theory). Furthermore, there exists a coupling between these two modes and this coupling provides a picture of the ELM cycle

Edge instabilities of topological superconductors

Energy Technology Data Exchange (ETDEWEB)

Hofmann, Johannes S. [Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg (Germany); Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Assaad, Fakher F. [Institut fuer Theoretische Physik und Astrophysik, Universitaet Wuerzburg (Germany); Schnyder, Andreas P. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

2016-07-01

Nodal topological superconductors display zero-energy Majorana flat bands at generic edges. The flatness of these edge bands, which is protected by time-reversal and translation symmetry, gives rise to an extensive ground state degeneracy and a diverging density of states. Therefore, even arbitrarily weak interactions lead to an instability of the flat-band edge states towards time-reversal and translation-symmetry broken phases, which lift the ground-state degeneracy. Here, we employ Monte Carlo simulations combined with mean-field considerations to examine the instabilities of the flat-band edge states of d{sub xy}-wave superconductors. We find that attractive interactions induce a complex s-wave pairing instability together with a density wave instability. Repulsive interactions, on the other hand, lead to ferromagnetism mixed with spin-triplet pairing at the edge. We discuss the implications of our findings for experiments on cuprate high-temperature superconductors.

Adobe Edge Quickstart Guide

CERN Document Server

Labrecque, Joseph

2012-01-01

Adobe Edge Quickstart Guide is a practical guide on creating engaging content for the Web with Adobe's newest HTML5 tool. By taking a chapter-by-chapter look at each major aspect of Adobe Edge, the book lets you digest the available features in small, easily understandable chunks, allowing you to start using Adobe Edge for your web design needs immediately. If you are interested in creating engaging motion and interactive compositions using web standards with professional tooling, then this book is for you. Those with a background in Flash Professional wanting to get started quickly with Adobe

Analysis of human factors effects on the safety of transporting radioactive waste materials: Technical report

Energy Technology Data Exchange (ETDEWEB)

Abkowitz, M.D.; Abkowitz, S.B.; Lepofsky, M.

1989-04-01

This report examines the extent of human factors effects on the safety of transporting radioactive waste materials. It is seen principally as a scoping effort, to establish whether there is a need for DOE to undertake a more formal approach to studying human factors in radioactive waste transport, and if so, logical directions for that program to follow. Human factors effects are evaluated on driving and loading/transfer operations only. Particular emphasis is placed on the driving function, examining the relationship between human error and safety as it relates to the impairment of driver performance. Although multi-modal in focus, the widespread availability of data and previous literature on truck operations resulted in a primary study focus on the trucking mode from the standpoint of policy development. In addition to the analysis of human factors accident statistics, the report provides relevant background material on several policies that have been instituted or are under consideration, directed at improving human reliability in the transport sector. On the basis of reported findings, preliminary policy areas are identified. 71 refs., 26 figs., 5 tabs.

Design of a Control System for Quality Maintenance on Cutting Edges of Files Production

Directory of Open Access Journals (Sweden)

E. Seabra

2000-01-01

Full Text Available The file cutting edges are the most important parameter that influence the performance of the filing operation. The practice shows that the most efficient way of generating these cutting edges is by penetration, by blow, of a cutting tool, which creates a plastic deformation on the file body. The penetration depth is probably the most important factor of the final quality of a file. In the existing machines of files manufacturing, this depth is manually adjusted by the operator, using specific mechanism. This means that files are manufactured on an empirical basis, relying on subjective factors, that do not allow to keep constant quality level of the production. In a research work, being developed in the University of Minho, it is intended to eliminate the subjectivity factors by the means of the evolution of the present “all-mechanical” system to a “mechatronic” one. In this paper, which is related with that research work, it presented a study of a round files production machine, regarding the identification, as well as the categorisation, of the operating parameters that affect the cutting edges production. They are, as well, defined and quantified those factors that influence the final quality of a round file.

The End-to-end Demonstrator for improved decision making in the water sector in Europe (EDgE)

Science.gov (United States)

Wood, Eric; Wanders, Niko; Pan, Ming; Sheffield, Justin; Samaniego, Luis; Thober, Stephan; Kumar, Rohinni; Prudhomme, Christel; Houghton-Carr, Helen

2017-04-01

High-resolution simulations of water resources from hydrological models are vital to supporting important climate services. Apart from a high level of detail, both spatially and temporally, it is important to provide simulations that consistently cover a range of timescales, from historical reanalysis to seasonal forecast and future projections. In the new EDgE project commissioned by the ECMWF (C3S) we try to fulfill these requirements. EDgE is a proof-of-concept project which combines climate data and state-of-the-art hydrological modelling to demonstrate a water-oriented information system implemented through a web application. EDgE is working with key European stakeholders representative of private and public sectors to jointly develop and tailor approaches and techniques. With these tools, stakeholders are assisted in using improved climate information in decision-making, and supported in the development of climate change adaptation and mitigation policies. Here, we present the first results of the EDgE modelling chain, which is divided into three main processes: 1) pre-processing and downscaling; 2) hydrological modelling; 3) post-processing. Consistent downscaling and bias corrections for historical simulations, seasonal forecasts and climate projections ensure that the results across scales are robust. The daily temporal resolution and 5km spatial resolution ensure locally relevant simulations. With the use of four hydrological models (PCR-GLOBWB, VIC, mHM, Noah-MP), uncertainty between models is properly addressed, while consistency is guaranteed by using identical input data for static land surface parameterizations. The forecast results are communicated to stakeholders via Sectoral Climate Impact Indicators (SCIIs) that have been created in collaboration with the end-user community of the EDgE project. The final product of this project is composed of 15 years of seasonal forecast and 10 climate change projections, all combined with four hydrological

Consideration of the FQPA Safety Factor and Other Uncertainty Factors in Cumulative Risk Assessment of Chemicals Sharing a Common Mechanism of Toxicity

Science.gov (United States)

This guidance document provides OPP's current thinking on application of the provision in FFDCA about an additional safety factor for the protection of infants and children in the context of cumulative risk assessments.

Degenerate band edge laser

Science.gov (United States)

Veysi, Mehdi; Othman, Mohamed A. K.; Figotin, Alexander; Capolino, Filippo

2018-05-01

We propose a class of lasers based on a fourth-order exceptional point of degeneracy (EPD) referred to as the degenerate band edge (DBE). EPDs have been found in parity-time-symmetric photonic structures that require loss and/or gain; here we show that the DBE is a different kind of EPD since it occurs in periodic structures that are lossless and gainless. Because of this property, a small level of gain is sufficient to induce single-frequency lasing based on a synchronous operation of four degenerate Floquet-Bloch eigenwaves. This lasing scheme constitutes a light-matter interaction mechanism that leads also to a unique scaling law of the laser threshold with the inverse of the fifth power of the laser-cavity length. The DBE laser has the lowest lasing threshold in comparison to a regular band edge laser and to a conventional laser in cavities with the same loaded quality (Q ) factor and length. In particular, even without mirror reflectors the DBE laser exhibits a lasing threshold which is an order of magnitude lower than that of a uniform cavity laser of the same length and with very high mirror reflectivity. Importantly, this novel DBE lasing regime enforces mode selectivity and coherent single-frequency operation even for pumping rates well beyond the lasing threshold, in contrast to the multifrequency nature of conventional uniform cavity lasers.

Ex vivo hydrodynamics after central and paracommissural edge-to-edge technique: A further step toward transcatheter tricuspid repair?

Science.gov (United States)

Stock, Sina; Bohm, Heidemarie; Scharfschwerdt, Michael; Richardt, Doreen; Meyer-Saraei, Roza; Tsvelodub, Stanislav; Sievers, Hans-Hinrich

2018-03-01

Transcatheter approaches in heart valve disease became tremendously important and are currently established in the aortic position, but transcatheter tricuspid repair is still in its beginning and remains challenging. Replicating the surgical edge-to-edge technique, for example, with the MitraClip System (Abbott Vascular, Santa Clara, Calif), represents a promising option and has been reported successfully in small numbers of cases. However, up to now, few data considering the edge-to-edge technique as a transcatheter approach are available. This study aims to determine the ex vivo hydrodynamics after the central and paracommissural edge-to-edge technique in different pathologies. Because of basal or apical dislocation of papillary muscles, leaflet prolapse or tethering was simulated in porcine tricuspid valves mounted on a flexible holding device. Central and paracommissural edge-to-edge techniques were evaluated successively in these pathologies. Regurgitant volume and mean transvalvular gradient were determined in a pulse duplicator. In this ex vivo model, the isolated edge-to-edge technique reduced tricuspid regurgitation. In the prolapse model, regurgitant volume decreased significantly after central edge-to-edge technique (from 49.4 ± 13.6 mL/stroke to 39.3 ± 14.1 mL/stroke). In the tethering model, both the central and the paracommissural edge-to-edge techniques led to a significant decrease (from 48.7 ± 13.9 to 43.6 ± 15.6 and to 41.1 ± 13.8 mL/stroke). In all cases, the reduction of regurgitant volume was achieved at the cost of significantly increased mean transvalvular gradient. This study provides a reduction of tricuspid regurgitation after the edge-to-edge technique in the specific experimental setup. Whether this reduction is sufficient to treat tricuspid regurgitation successfully in clinical practice remains to be established. Transcatheter approaches need to be evaluated further, probably with regard to concomitant annuloplasty

Edge Simulation Laboratory

Energy Technology Data Exchange (ETDEWEB)

Krasheninnikov, Sergei I. [Univ. of California, San Diego, CA (United States); Angus, Justin [Univ. of California, San Diego, CA (United States); Lee, Wonjae [Univ. of California, San Diego, CA (United States)

2018-01-05

The goal of the Edge Simulation Laboratory (ESL) multi-institutional project is to advance scientific understanding of the edge plasma region of magnetic fusion devices via a coordinated effort utilizing modern computing resources, advanced algorithms, and ongoing theoretical development. The UCSD team was involved in the development of the COGENT code for kinetic studies across a magnetic separatrix. This work included a kinetic treatment of electrons and multiple ion species (impurities) and accurate collision operators.

AliEn - EDG Interoperability in ALICE

CERN Document Server

Bagnasco, S; Buncic, P; Carminati, F; Cerello, P G; Saiz, P

2003-01-01

AliEn (ALICE Environment) is a GRID-like system for large scale job submission and distributed data management developed and used in the context of ALICE, the CERN LHC heavy-ion experiment. With the aim of exploiting upcoming Grid resources to run AliEn-managed jobs and store the produced data, the problem of AliEn-EDG interoperability was addressed and an in-terface was designed. One or more EDG (European Data Grid) User Interface machines run the AliEn software suite (Cluster Monitor, Storage Element and Computing Element), and act as interface nodes between the systems. An EDG Resource Broker is seen by the AliEn server as a single Computing Element, while the EDG storage is seen by AliEn as a single, large Storage Element; files produced in EDG sites are registered in both the EDG Replica Catalogue and in the AliEn Data Catalogue, thus ensuring accessibility from both worlds. In fact, both registrations are required: the AliEn one is used for the data management, the EDG one to guarantee the integrity and...

Energetics of edge oxidization of graphene nanoribbons

Science.gov (United States)

Yasuma, Airi; Yamanaka, Ayaka; Okada, Susumu

2018-06-01

On the basis of the density functional theory, we studied the geometries and energetics of O atoms adsorbed on graphene edges for simulating the initial stage of the edge oxidization of graphene. Our calculations showed that oxygen atoms are preferentially adsorbed onto the graphene edges with the zigzag portion, resulting in a large adsorption energy of about 5 eV. On the other hand, the edges with armchair shape are rarely oxidized, or the oxidization causes substantial structural reconstructions, because of the stable covalent bond at the armchair edge with the triple bond nature. Furthermore, the energetics sensitively depends on the edge angles owing to the inhomogeneity of the charge density at the edge atomic sites.

Edge geometry effects on resonance response of electroplated cylindrical Ni/PZT/Ni magnetoelectric composites

Science.gov (United States)

Yakubov, Vladislav; Xu, Lirong; Volinsky, Alex A.; Qiao, Lijie; Pan, De'an

2017-08-01

Trilayer Ni/PZT/Ni cylindrical magnetoelectric (ME) composites were prepared by electrodeposition, a process, which creates sub-millimeter raised edges due to current concentration near sharp points. The ME response in both axial and vertical modes was measured with the edges, with only outer edges removed, and with both outer and inner edges removed. The ME voltage coefficient improved at resonance by 40% and 147% without the edges in the vertical and axial modes, respectively. The observed improvements in three different samples were only present at the ME resonance and no changes were detected outside of the ME resonance. Mechanical quality factor at resonance also improved with no effect on the resonant frequency. Experimentally demonstrated minor geometry changes resulted in substantial ME improvement at resonant frequency. This study demonstrates device performance optimization. The observed effects have been attributed to improved vibrations in terms of decreased damping coefficient and enhanced vibration amplitude at resonance.

Edge geometry effects on resonance response of electroplated cylindrical Ni/PZT/Ni magnetoelectric composites

Directory of Open Access Journals (Sweden)

Vladislav Yakubov

2017-08-01

Full Text Available Trilayer Ni/PZT/Ni cylindrical magnetoelectric (ME composites were prepared by electrodeposition, a process, which creates sub-millimeter raised edges due to current concentration near sharp points. The ME response in both axial and vertical modes was measured with the edges, with only outer edges removed, and with both outer and inner edges removed. The ME voltage coefficient improved at resonance by 40% and 147% without the edges in the vertical and axial modes, respectively. The observed improvements in three different samples were only present at the ME resonance and no changes were detected outside of the ME resonance. Mechanical quality factor at resonance also improved with no effect on the resonant frequency. Experimentally demonstrated minor geometry changes resulted in substantial ME improvement at resonant frequency. This study demonstrates device performance optimization. The observed effects have been attributed to improved vibrations in terms of decreased damping coefficient and enhanced vibration amplitude at resonance.

Numerical Analysis of Edge Over Coating and Baffle Effect on Hot-Dip Galvanizing

Science.gov (United States)

Bao, Chengren; Kang, Yonglin; Li, Yan

2017-06-01

In hot-dip galvanizing process, air jet wiping control is so crucial to determine the coating thickness and uniformity of the zinc layer on the steel strip. A numerical simulation of gas-jet wiping in hot-dip galvanizing was conducted to minimize the occurrence of edge over coating (EOC). The causes of EOC were identified by contrasting and analyzing the airflow fields on the strip edge with and without a baffle. The factors influencing the airflow field on the strip edge during the change in the gap between the baffle and the strip edge were also analyzed. The effect of the distance between the air knife and the strip was evaluated. Technological parameters with on-site guidance role were obtained by combining them with the actual production to elucidate the role of the baffle in restraining the occurrence of EOC. The uniform distribution of pressure and coating thickness on the strip is achieved when the distance of the baffle from the strip edge is about 0.3 times of the jetting distance.

Achieving a competitive edge -- A comparison/contrast of two examples

International Nuclear Information System (INIS)

Scholl, P.L.; Ward, D.P.

1996-01-01

As the electric power industry moves from the regulated monopoly environment to one of open competition, the need to achieve and maintain a competitive advantage becomes critical. In the competitive market, having a competitive edge means having goods and services that the market prefers, i.e., buyers in the market prefer to purchase your goods and services rather than your competitors'. For electric power generating facilities, the market is the wholesale market, and because electric power is essentially a commodity, i.e., a megawatthour from one generating facility is the same as a megawatthour from another generating facility, the primary distinguishing factor in the market is price.d therefore, having a competitive edge in the market means having a lower price than the competition. This paper describes the basic elements of achieving a competitive edge and discusses how these elements are being used by two utilities with very different circumstances to improve their competitive positions

Crop type influences edge effects on the reproduction of songbirds in sagebrush habitat near agriculture

Directory of Open Access Journals (Sweden)

Elly C. Knight

2014-06-01

Full Text Available Extensive fragmentation of the sagebrush shrubsteppe of western North America could be contributing to observed population declines of songbirds in sagebrush habitat. We examined whether habitat fragmentation impacts the reproduction of songbirds in sagebrush edge habitat near agriculture, and if potential impacts vary depending on the adjacent crop type. Specifically, we evaluated whether nest abundance and nest survival varied between orchard edge habitat, vineyard edge habitat, and interior habitat. We then examined whether the local nest predator community and vegetation could explain the differences detected. We detected fewer nests in edge than interior habitat. Nest abundance per songbird was also lower in edge than interior habitat, although only adjacent to vineyards. Nest predation was more frequent in orchard edge habitat than vineyard edge or interior habitat. Predators identified with nest cameras were primarily snakes, however, reduced nest survival in orchard edge habitat was not explained by differences in the abundance of snakes or any other predator species identified. Information theoretic analysis of daily survival rates showed that greater study plot shrub cover and lower grass height at nests were partially responsible for the lower rate of predation-specific daily nest survival rate (PDSR observed in orchard edge habitat, but additional factors are likely important. Results of this study suggest that different crop types have different edge effects on songbirds nesting in sagebrush shrubsteppe, and that these reproductive edge effects may contribute to observed declines of these species. Habitat managers should avoid the creation of new orchard-sagebrush habitat edges to avoid further impacts on already declining songbird populations.

Acyclicity in edge-colored graphs

DEFF Research Database (Denmark)

Gutin, Gregory; Jones, Mark; Sheng, Bin

2017-01-01

A walk W in edge-colored graphs is called properly colored (PC) if every pair of consecutive edges in W is of different color. We introduce and study five types of PC acyclicity in edge-colored graphs such that graphs of PC acyclicity of type i is a proper superset of graphs of acyclicity of type i......+1, i=1,2,3,4. The first three types are equivalent to the absence of PC cycles, PC closed trails, and PC closed walks, respectively. While graphs of types 1, 2 and 3 can be recognized in polynomial time, the problem of recognizing graphs of type 4 is, somewhat surprisingly, NP-hard even for 2-edge-colored...... graphs (i.e., when only two colors are used). The same problem with respect to type 5 is polynomial-time solvable for all edge-colored graphs. Using the five types, we investigate the border between intractability and tractability for the problems of finding the maximum number of internally vertex...

Edge-effect interactions in fragmented and patchy landscapes.

Science.gov (United States)

Porensky, Lauren M; Young, Truman P

2013-06-01

Ecological edges are increasingly recognized as drivers of landscape patterns and ecosystem processes. In fragmented and patchy landscapes (e.g., a fragmented forest or a savanna with scattered termite mounds), edges can become so numerous that their effects pervade the entire landscape. Results of recent studies in such landscapes show that edge effects can be altered by the presence or proximity of other nearby edges. We considered the theoretical significance of edge-effect interactions, illustrated various landscape configurations that support them and reviewed existing research on this topic. Results of studies from a variety of locations and ecosystem types show that edge-effect interactions can have significant consequences for ecosystems and conservation, including higher tree mortality rates in tropical rainforest fragments, reduced bird densities in grassland fragments, and bush encroachment and reduced wildlife densities in a tropical savanna. To clarify this underappreciated concept and synthesize existing work, we devised a conceptual framework for edge-effect interactions. We first worked to reduce terminological confusion by clarifying differences among terms such as edge intersection and edge interaction. For cases in which nearby edge effects interact, we proposed three possible forms of interaction: strengthening (presence of a second edge causes stronger edge effects), weakening (presence of a second edge causes weaker edge effects), and emergent (edge effects change completely in the presence of a second edge). By clarifying terms and concepts, this framework enables more precise descriptions of edge-effect interactions and facilitates comparisons of results among disparate study systems and response variables. A better understanding of edge-effect interactions will pave the way for more appropriate modeling, conservation, and management in complex landscapes. © 2013 Society for Conservation Biology.

Refresher training as an important factor affecting safety of atomic energy utilization facilities

International Nuclear Information System (INIS)

Kapralov, E.

2005-01-01

Refresher training appears to be one of the most important factors, affecting safety of atomic energy utilization facilities. To provide up-to-date refresher training programs and courses TC NRS implements best training practice based on the actual and perspective Russian national and international norms, regulations, standards and recommendations. (author)

Safety of recombinant human platelet-derived growth factor-BB in Augment® Bone Graft

Directory of Open Access Journals (Sweden)

Luis A Solchaga

2012-12-01

Full Text Available This article discusses nonclinical and clinical data regarding the safety of recombinant human platelet-derived growth factor-BB as a component of the Augment® Bone Graft (Augment. Augment is a bone graft substitute intended to be used as an alternative to autologous bone graft in the fusion of hindfoot and ankle joints. Nonclinical studies included assessment of the pharmacokinetic profile of intravenously administered recombinant human platelet-derived growth factor-BB in rat and dog, effects of intravenous administration of recombinant human platelet-derived growth factor-BB in a reproductive and development toxicity study in rats, and chronic toxicity and carcinogenicity of Augment in a 12-month implantation model. These studies showed that systemic exposure was brief and clearance was rapid. No signs of toxicity, carcinogenicity, or tumor promotion were observed even with doses far exceeding the maximum clinical dose. Results of clinical trials (605 participants and commercial use of recombinant human platelet-derived growth factor-BB containing products indicate that these products are not associated with increased incidence of adverse events or cancer. The safety data presented provide evidence that recombinant human platelet-derived growth factor-BB is a safe therapeutic when used in combination products as a single administration during surgical procedures for bone repair and fusion. There is no evidence associating use of recombinant human platelet-derived growth factor-BB in Augment with chronic toxicity, carcinogenicity, or tumor promotion.

Are quantum spin Hall edge modes more resilient to disorder, sample geometry and inelastic scattering than quantum Hall edge modes?

Science.gov (United States)

Mani, Arjun; Benjamin, Colin

2016-04-13

On the surface of 2D topological insulators, 1D quantum spin Hall (QSH) edge modes occur with Dirac-like dispersion. Unlike quantum Hall (QH) edge modes, which occur at high magnetic fields in 2D electron gases, the occurrence of QSH edge modes is due to spin-orbit scattering in the bulk of the material. These QSH edge modes are spin-dependent, and chiral-opposite spins move in opposing directions. Electronic spin has a larger decoherence and relaxation time than charge. In view of this, it is expected that QSH edge modes will be more robust to disorder and inelastic scattering than QH edge modes, which are charge-dependent and spin-unpolarized. However, we notice no such advantage accrues in QSH edge modes when subjected to the same degree of contact disorder and/or inelastic scattering in similar setups as QH edge modes. In fact we observe that QSH edge modes are more susceptible to inelastic scattering and contact disorder than QH edge modes. Furthermore, while a single disordered contact has no effect on QH edge modes, it leads to a finite charge Hall current in the case of QSH edge modes, and thus a vanishing of the pure QSH effect. For more than a single disordered contact while QH states continue to remain immune to disorder, QSH edge modes become more susceptible--the Hall resistance for the QSH effect changes sign with increasing disorder. In the case of many disordered contacts with inelastic scattering included, while quantization of Hall edge modes holds, for QSH edge modes a finite charge Hall current still flows. For QSH edge modes in the inelastic scattering regime we distinguish between two cases: with spin-flip and without spin-flip scattering. Finally, while asymmetry in sample geometry can have a deleterious effect in the QSH case, it has no impact in the QH case.

Are quantum spin Hall edge modes more resilient to disorder, sample geometry and inelastic scattering than quantum Hall edge modes?

International Nuclear Information System (INIS)

Mani, Arjun; Benjamin, Colin

2016-01-01

On the surface of 2D topological insulators, 1D quantum spin Hall (QSH) edge modes occur with Dirac-like dispersion. Unlike quantum Hall (QH) edge modes, which occur at high magnetic fields in 2D electron gases, the occurrence of QSH edge modes is due to spin–orbit scattering in the bulk of the material. These QSH edge modes are spin-dependent, and chiral-opposite spins move in opposing directions. Electronic spin has a larger decoherence and relaxation time than charge. In view of this, it is expected that QSH edge modes will be more robust to disorder and inelastic scattering than QH edge modes, which are charge-dependent and spin-unpolarized. However, we notice no such advantage accrues in QSH edge modes when subjected to the same degree of contact disorder and/or inelastic scattering in similar setups as QH edge modes. In fact we observe that QSH edge modes are more susceptible to inelastic scattering and contact disorder than QH edge modes. Furthermore, while a single disordered contact has no effect on QH edge modes, it leads to a finite charge Hall current in the case of QSH edge modes, and thus a vanishing of the pure QSH effect. For more than a single disordered contact while QH states continue to remain immune to disorder, QSH edge modes become more susceptible—the Hall resistance for the QSH effect changes sign with increasing disorder. In the case of many disordered contacts with inelastic scattering included, while quantization of Hall edge modes holds, for QSH edge modes a finite charge Hall current still flows. For QSH edge modes in the inelastic scattering regime we distinguish between two cases: with spin-flip and without spin-flip scattering. Finally, while asymmetry in sample geometry can have a deleterious effect in the QSH case, it has no impact in the QH case. (paper)

Magnetism of Nanographene-Based Microporous Carbon and Its Applications: Interplay of Edge Geometry and Chemistry Details in the Edge State

Science.gov (United States)

Enoki, Toshiaki; Kiguchi, Manabu

2018-03-01

This paper is a contribution to the Physical Review Applied collection in memory of Mildred S. Dresselhaus. Nanographenes have important edge geometry dependence in their electronic structures. In armchair edges, electron wave interference works to contribute to energetic stability. Meanwhile, zigzag edges possess an edge-localized and spin-polarized nonbonding edge state, which causes electronic, magnetic, and chemical activities. In addition to the geometry dependence, the electronic structures are seriously affected by edge chemistry details. The edge chemistry dependence together with edge geometries on the electronic structures are discussed with samples of randomly networked nanographenes (microporous activated carbon fibers) in pristine state and under high-temperature annealing. In the pristine sample with the edges oxidized in ambient atmospheric conditions, the edge state, which is otherwise unstable, can be stabilized because of the charge transfer from nanographene to terminating oxygen. Nanographene, whose edges consist of a combination of magnetic zigzag edges and nonmagnetic armchair edges, is found to be ferrimagnetic with a nonzero net magnetic moment created under the interplay between a strong intrazigzag-edge ferromagnetic interaction and intermediate-strength interzigzag-edge antiferromagnetic-ferromagnetic interaction. At heat-treatment temperatures just below the fusion start (approximately 1500 K), the edge-terminating structure is changed from oxygen-containing groups to hydrogen in the nanographene network. Additionally, hydrogen-terminated zigzag edges, which are present as the majority and chemically unstable, play a triggering role in fusion above 1500 K. The fusion start brings about an insulator-to-metal transition at TI -M˜1500 K . Local fusions taking place percolatively between nanographenes work to expand the π -bond network, eventually resulting in the development of antiferromagnetic short-range order toward spin glass in the

A development of an evaluation flow chart for seismic stability of rock slopes based on relations between safety factor and sliding failure

International Nuclear Information System (INIS)

Kawai, Tadashi; Ishimaru, Makoto

2010-01-01

Recently, it is necessary to assess quantitatively seismic safety of critical facilities against the earthquake- induced rock slope failure from the viewpoint of seismic PSA. Under these circumstances, it is needed to evaluate the seismic stability of surrounding slopes against extremely strong ground motions. In order to evaluate the seismic stability of surrounding slopes, the most conventional method is to compare safety factors on an expected sliding surface, which is calculated from the stability analysis based on the limit equilibrium concept, to a critical value which judges stability or instability. The method is very effective to examine whether or not the sliding surface is safe. However, it does not mean that the sliding surface falls whenever the safety factor becomes smaller than the critical value during an earthquake. Therefore the authors develop a new evaluation flow chart for the seismic stability of rock slopes based on relations between safety factor and sliding failure. Furthermore, the developed flow chart was validated by comparing two kinds of safety factors calculated from a centrifuge test result concerned with a rock slope. (author)

Improving color constancy by photometric edge weighting

NARCIS (Netherlands)

Gijsenij, A.; Gevers, T.; van de Weijer, J.

2012-01-01

Edge-based color constancy methods make use of image derivatives to estimate the illuminant. However, different edge types exist in real-world images, such as material, shadow, and highlight edges. These different edge types may have a distinctive influence on the performance of the illuminant

ORGANIZATIONAL CULTURE AS ONE OF THE MAIN FACTORS FOR THE SUCCESSFUL SAFETY MANAGEMENT

Directory of Open Access Journals (Sweden)

Snežana Živković

2016-05-01

Full Text Available The goal of this research is to establish the influence of organizational culture on the system of safety and health at work. The research sample included 556 respondents of various activities in Russia. Based on the results, it can be concluded that there is a statistically significant connection of the Attitude towards occupational safety with 5 out of 7 aspects of organizational culture, as well as with the general factor of Usefulness of the manner of management. In addition, there is a statistically significant connection to age, total years of service and qualifications. Through a comparative analysis of results acquired in the Republic of Serbia and Russia, differences in attitudes towards safety and health activities at work were acquired i.e. there is a difference between the average answers of respondents from Serbia and Russia in the Attitude towards occupational safety which is on average slightly more prominent in respondents from Serbia. In relation to organizational culture aspects, there are differences in Vision, Credibility, Feedback and recognition as well as Responsibility. Respondents from Serbia have higher average values on all these measures, but all the differences are small (all effect sizes are below 0.2.

Leadership and Management for Safety. General Safety Requirements (Arabic Edition)

International Nuclear Information System (INIS)

2016-01-01

This Safety Requirements publication establishes requirements that support Principle 3 of the Fundamental Safety Principles in relation to establishing, sustaining and continuously improving leadership and management for safety and an integrated management system. It emphasizes that leadership for safety, management for safety, an effective management system and a systemic approach (i.e. an approach in which interactions between technical, human and organizational factors are duly considered) are all essential to the specification and application of adequate safety measures and to the fostering of a strong safety culture. Leadership and an effective management system will integrate safety, health, environmental, security, quality, human-and-organizational factors, societal and economic elements. The management system will ensure the fostering of a strong safety culture, regular assessment of performance and the application of lessons from experience. The publication is intended for use by regulatory bodies, operating organizations and other organizations concerned with facilities and activities that give rise to radiation risks.

Leadership and Management for Safety. General Safety Requirements (Chinese Edition)

International Nuclear Information System (INIS)

2016-01-01

This Safety Requirements publication establishes requirements that support Principle 3 of the Fundamental Safety Principles in relation to establishing, sustaining and continuously improving leadership and management for safety and an integrated management system. It emphasizes that leadership for safety, management for safety, an effective management system and a systemic approach (i.e. an approach in which interactions between technical, human and organizational factors are duly considered) are all essential to the specification and application of adequate safety measures and to the fostering of a strong safety culture. Leadership and an effective management system will integrate safety, health, environmental, security, quality, human-and-organizational factors, societal and economic elements. The management system will ensure the fostering of a strong safety culture, regular assessment of performance and the application of lessons from experience. The publication is intended for use by regulatory bodies, operating organizations and other organizations concerned with facilities and activities that give rise to radiation risks.

Leadership and Management for Safety. General Safety Requirements (French Edition)

International Nuclear Information System (INIS)

2016-01-01

This Safety Requirements publication establishes requirements that support Principle 3 of the Fundamental Safety Principles in relation to establishing, sustaining and continuously improving leadership and management for safety and an integrated management system. It emphasizes that leadership for safety, management for safety, an effective management system and a systemic approach (i.e. an approach in which interactions between technical, human and organizational factors are duly considered) are all essential to the specification and application of adequate safety measures and to the fostering of a strong safety culture. Leadership and an effective management system will integrate safety, health, environmental, security, quality, human-and-organizational factors, societal and economic elements. The management system will ensure the fostering of a strong safety culture, regular assessment of performance and the application of lessons from experience. The publication is intended for use by regulatory bodies, operating organizations and other organizations concerned with facilities and activities that give rise to radiation risks.

Leadership and Management for Safety. General Safety Requirements (Spanish Edition)

International Nuclear Information System (INIS)

2017-01-01

his Safety Requirements publication establishes requirements that support Principle 3 of the Fundamental Safety Principles in relation to establishing, sustaining and continuously improving leadership and management for safety and an integrated management system. It emphasizes that leadership for safety, management for safety, an effective management system and a systemic approach (i.e. an approach in which interactions between technical, human and organizational factors are duly considered) are all essential to the specification and application of adequate safety measures and to the fostering of a strong safety culture. Leadership and an effective management system will integrate safety, health, environmental, security, quality, human-and-organizational factors, societal and economic elements. The management system will ensure the fostering of a strong safety culture, regular assessment of performance and the application of lessons from experience. The publication is intended for use by regulatory bodies, operating organizations and other organizations concerned with facilities and activities that give rise to radiation risks.

Unconventional quantized edge transport in the presence of inter-edge coupling in intercalated graphene

OpenAIRE

Li, Yuanchang

2016-01-01

It is generally believed that the inter-edge coupling destroys the quantum spin Hall (QSH) effect along with the gap opening at the Dirac points. Using first-principles calculations, we find that the quantized edge transport persists in the presence of inter-edge coupling in Ta intercalated epitaxial graphene on SiC(0001), being a QSH insulator with the non-trivial gap of 81 meV. In this case, the band is characterized by two perfect Dirac cones with different Fermi velocities, yet only one m...

A Framework for Seismic Design of Items in Safety-Critical Facilities for Implementing a Risk-Informed Defense-in-Depth-Based Concept

Directory of Open Access Journals (Sweden)

Tatsuya Itoi

2017-05-01

Full Text Available Recently, especially after the 2011 off the Pacific coast of Tohoku earthquake and the Fukushima Daiichi nuclear power plant accident, the need for treating residual risks and cliff-edge effects in safety-critical facilities has been widely recognized as an extremely important issue. In this article, the sophistication of seismic designs in safety-critical facilities is discussed from the viewpoint of mitigating the consequences of accidents, such as the avoidance of cliff-edge effects. For this purpose, the implementation of a risk-informed defense-in-depth-based framework is proposed in this study. A basic framework that utilizes diversity in the dynamic characteristics of items and also provides additional seismic margin to items important for safety when needed is proposed to prevent common cause failure and to avoid cliff-edge effects as far as practicable. The proposed method is demonstrated to be effective using an example calculation.

Identification and assessment of organisational factors related to the safety of NPPs - State-of-the-Art Report

International Nuclear Information System (INIS)

Baumont, Genevieve; Bourrier, Mathilde; Frischknecht, Albert; Schoenfeld, Isabelle; Weber, Mike J.

1999-01-01

The initiation of this State-of-the-Art Report (SOAR) on Organisational Factors Identification and Assessment comes from operating experience associated with a number of major events world-wide which caused power plants to be shutdown for a significant period of time. Root cause assessments of these events identified weaknesses in organisational factors as contributing to these events. There is general recognition that organisational factors need to be evaluated for their contribution to plant safety performance and risk to prevent their recurrence in events. There is a need to collect and analyse operational and event data from the nuclear environment to determine the safety and risk significance of organisational factors, to identify assessment methods for those factors, and to gain peer review of the results to ensure credibility and acceptability of these methods and possibly their measures. The SOAR presents a representative view of developments in this field and addresses the following topics: - identification of organisational factors; - identification of methods for the evaluation of organisational factors; - identification of methods for the evaluation of whole organisations; - identification of gaps in knowledge and needed research to evaluate adequately the influence of organisation and management on safety and risk. The workshop participants identified 12 organisational factors as important to assess in determining organisational safety performance. They are: external influences; goals and strategies; management functions and overview; resource allocation; human resource management; training; co-ordination of work; organisational knowledge; proceduralization; organisational culture; organisational learning; and communication. Different cultural backgrounds of participants using their own terminology sometimes made it difficult to have a common definition for certain factors. Some factors could be defined by consensus; other factors such as

Decommissioning: Regulatory activities and identification of key organizational and human factors safety issues

International Nuclear Information System (INIS)

Durbin, N.E.; Melber, B.D.; Lekberg, A.

2001-12-01

In the late 1990's the Swedish government decided to shut down Unit 1 of the Barsebaeck nuclear power plant. This report documents some of the efforts made by the Swedish Nuclear Power Inspectorate (SKI) to address human factors and organizational issues in nuclear safety during decommissioning of a nuclear facility. This report gives a brief review of the background to the decommissioning of Barsebaeck 1 and points out key safety issues that can arise during decommissioning. The main regulatory activities that were undertaken were requirements that the plant provide special safety reports on decommissioning focusing on first, the operation of both units until closure of Unit 1 and second, the operation of Unit 2 when Unit 1 was closed. In addition, SKI identified areas that might be affected by decommissioning and called these areas out for special attention. With regard to these areas of special attention, SKI required that the plant provide monthly reports on changing and emerging issues as well as self-assessments of the areas to be addressed in the special safety reports. Ten key safety issues were identified and evaluated with regard to different stages of decommissioning and with regard to the actions taken by Barsebaeck. Some key conclusions from SKI's experience in regulating a decommissioning nuclear power plant conclude the report

Safety culture management: The importance of organizational factors

International Nuclear Information System (INIS)

Haber, S.B.; Shurberg, D.A.; Jacobs, R.; Hofmann, D.

1995-01-01

The concept of safety culture has been used extensively to explain the underlying causes of performance based events, both positive and negative, across the nuclear industry. The work described in this paper represents several years of effort to identify, define and assess the organizational factors important to safe performance in nuclear power plants (NPPs). The research discussed in this paper is primarily conducted in support of the US Nuclear Regulatory Commission's (NRC) efforts in understanding the impact of organizational performance on safety. As a result of a series of research activities undertaken by numerous NRC contractors, a collection of organizational dimensions has been identified and defined. These dimensions represent what is believed to be a comprehensive taxonomy of organizational elements that relate to the safe operation of nuclear power plants. Techniques were also developed by which to measure these organizational dimensions, and include structured interview protocols, behavioral checklists, and behavioral anchored rating scales (BARS). Recent efforts have focused on devising a methodology for the extraction of information related to the identified organizational dimensions from existing NRC documentation. This type of effort would assess the applicability of the organizational dimensions to existing NRC inspection and evaluation reports, refine the organizational dimensions previously developed so they are more relevant to the task of retrospective analysis, and attempt to rate plants based on the review of existing NRC documentation using the techniques previously developed for the assessment of organizational dimensions

On the asymptotic of solutions of elliptic boundary value problems in domains with edges

International Nuclear Information System (INIS)

Nkemzi, B.

2005-10-01

Solutions of elliptic boundary value problems in three-dimensional domains with edges may exhibit singularities. The usual procedure to study these singularities is by the application of the classical Mellin transformation or continuous Fourier transformation. In this paper, we show how the asymptotic behavior of solutions of elliptic boundary value problems in general three-dimensional domains with straight edges can be investigated by means of discrete Fourier transformation. We apply this approach to time-harmonic Maxwell's equations and prove that the singular solutions can fully be described in terms of Fourier series. The representation here can easily be used to approximate three-dimensional stress intensity factors associated with edge singularities. (author)

Edge loading has a paradoxical effect on wear in metal-on-polyethylene total hip arthroplasties.

Science.gov (United States)

Harris, William H

2012-11-01

Edge wear is an adverse factor that can negatively impact certain THAs. In some metal-on-metal THAs, it can lead to adverse tissue reactions including aseptic lymphocytic vasculitis-associated lesions and even to pseudotumor formation. In some ceramic-on-ceramic THAs, it can lead to squeaking and/or stripe wear. Edge wear in metal-on-metal and ceramic-on-ceramic THAs can also be associated with accelerated wear across the articulation of these joints. I asked: Does edge wear occur in metal-on-polyethylene (MOP) articulations? And if so, does it increase joint wear? I examined the evidence in the literature for edge wear occurring in MOP THA and then assessed the evidence in the literature for data supporting the concept that edge wear in MOP hips could accelerate wear across the articulation over time. Extensive data in the literature confirm edge wear is common in MOP THA. Surprisingly, the evidence does not support that it accelerates wear across the articulation. In fact, substantial data support the concept that it does not. These observations suggest, in terms of edge wear accelerating overall wear, MOP articulation may have a privileged position compared to hard-on-hard THA articulations.

How Forest Inhomogeneities Affect the Edge Flow

DEFF Research Database (Denmark)

Boudreault, Louis-Étienne; Dupont, Sylvain; Bechmann, Andreas

2016-01-01

Most of our knowledge on forest-edge flows comes from numerical and wind-tunnel experiments where canopies are horizontally homogeneous. To investigate the impact of tree-scale heterogeneities (>1 m) on the edge-flow dynamics, the flow in an inhomogeneous forest edge on Falster island in Denmark...... is investigated using large-eddy simulation. The three-dimensional forest structure is prescribed in the model using high resolution helicopter-based lidar scans. After evaluating the simulation against wind measurements upwind and downwind of the forest leading edge, the flow dynamics are compared between...... the scanned forest and an equivalent homogeneous forest. The simulations reveal that forest inhomogeneities facilitate flow penetration into the canopy from the edge, inducing important dispersive fluxes in the edge region as a consequence of the flow spatial variability. Further downstream from the edge...

Crystallographic study of grain refinement in aluminum alloys using the edge-to-edge matching model

International Nuclear Information System (INIS)

Zhang, M.-X.; Kelly, P.M.; Easton, M.A.; Taylor, J.A.

2005-01-01

The edge-to-edge matching model for describing the interfacial crystallographic characteristics between two phases that are related by reproducible orientation relationships has been applied to the typical grain refiners in aluminum alloys. Excellent atomic matching between Al 3 Ti nucleating substrates, known to be effective nucleation sites for primary Al, and the Al matrix in both close packed directions and close packed planes containing these directions have been identified. The crystallographic features of the grain refiner and the Al matrix are very consistent with the edge-to-edge matching model. For three other typical grain refiners for Al alloys, TiC (when a = 0.4328 nm), TiB 2 and AlB 2 , the matching only occurs between the close packed directions in both phases and between the second close packed plane of the Al matrix and the second close packed plane of the refiners. According to the model, it is predicted that Al 3 Ti is a more powerful nucleating substrate for Al alloy than TiC, TiB 2 and AlB 2 . This agrees with the previous experimental results. The present work shows that the edge-to-edge matching model has the potential to be a powerful tool in discovering new and more powerful grain refiners for Al alloys

Edge Cut Domination, Irredundance, and Independence in Graphs

OpenAIRE

Fenstermacher, Todd; Hedetniemi, Stephen; Laskar, Renu

2016-01-01

An edge dominating set $F$ of a graph $G=(V,E)$ is an \\textit{edge cut dominating set} if the subgraph $\\langle V,G-F \\rangle$ is disconnected. The \\textit{edge cut domination number} $\\gamma_{ct}(G)$ of $G$ is the minimum cardinality of an edge cut dominating set of $G.$ In this paper we study the edge cut domination number and investigate its relationships with other parameters of graphs. We also introduce the properties edge cut irredundance and edge cut independence.

DAVs: Red Edge and Outbursts

Science.gov (United States)

Luan, Jing

2018-04-01

As established by ground based surveys, white dwarfs with hydrogen atmospheres pulsate as they cool across the temperature range, 12500Kred edge is a two-decade old puzzle. Recently, Kepler discovered a number of cool DAVs exhibiting sporadic outbursts separated by days, each lasting several hours, and releasing \\sim 10^{33}-10^{34} {erg}. We provide quantitative explanations for both the red edge and the outbursts. The minimal frequency for overstable modes rises abruptly near the red edge. Although high frequency overstable modes exist below the red edge, their photometric amplitudes are generally too small to be detected by ground based observations. Nevertheless, these overstable parent modes can manifest themselves through nonlinear mode couplings to damped daughter modes which generate limit cycles giving rise to photometric outbursts.

Human factor as nuclear safety element

International Nuclear Information System (INIS)

Valeca, S.C.; Preda, M.; Valeca, M.; Ana, E. M.; Popescu, D.

2008-01-01

National nuclear power system is based on western technology, it covers almost 20% from national need and could be briefly described by: - Safety and economic performances of Cernavoda NPP Unit 1; - Reduced influence on environment, population and workers; - Excellent ranking (place 4) among CANDU units from all over the world. Also, the national nuclear power system plays a major role in Romanian power policy accomplishment: - Energy safety and independence assurance; - Decrease of production of greenhouse effect gases; - Preserve the stability and adequacy of energy cost. 'Nuclear Safety' concept covers all the activities resulting from nuclear fuel cycle. By taking into account the international experience, the related activities are estimated to last around 70 years in Romania: - 10 years for site description and selection, design, manufacturing and commissioning activities; - 40 years for Nuclear Power Plant operation, maintenance and modernization activities; - 20 years for preservation and decommissioning activities. The above mentioned activities requires human resources, qualified and specialized in the following areas: - research and development; - equipment design, manufacturing and operation; - components construction and assembly, operation and maintenance. (authors)