A comprehensive study on pavement edge line implementation.

DOT National Transportation Integrated Search

2014-04-01

The previous 2011 study Safety Improvement from Edge Lines on Rural Two-Lane Highways analyzed the crash data of : three years before and one year after edge line implementation by using the latest safety analysis statistical method. It : concl...

Evaluation of the Safety Edge application in Oregon.

DOT National Transportation Integrated Search

2012-03-01

This report summarizes a recent assessment of the Safety Edge SM that was performed to determine the feasibility of using this pavement edge treatment on Oregon construction projects. The report includes a review of research that has been published a...

Evaluation of the safety edge application in Oregon.

DOT National Transportation Integrated Search

2012-03-01

This report summarizes a recent assessment of the Safety Edge SM that was performed to determine the feasibility of using this pavement edge treatment on Oregon construction projects. The report includes a review of research that has been published a...

The Stability Analysis Method of the Cohesive Granular Slope on the Basis of Graph Theory

PubMed Central

Guan, Yanpeng; Liu, Xiaoli; Wang, Enzhi; Wang, Sijing

2017-01-01

This paper attempted to provide a method to calculate progressive failure of the cohesive-frictional granular geomaterial and the spatial distribution of the stability of the cohesive granular slope. The methodology can be divided into two parts: the characterization method of macro-contact and the analysis of the slope stability. Based on the graph theory, the vertexes, the edges and the edge sequences are abstracted out to characterize the voids, the particle contact and the macro-contact, respectively, bridging the gap between the mesoscopic and macro scales of granular materials. This paper adopts this characterization method to extract a graph from a granular slope and characterize the macro sliding surface, then the weighted graph is analyzed to calculate the slope safety factor. Each edge has three weights representing the sliding moment, the anti-sliding moment and the braking index of contact-bond, respectively, E1E2E3E1E2E3. The safety factor of the slope is calculated by presupposing a certain number of sliding routes and reducing Weight E3 repeatedly and counting the mesoscopic failure of the edge. It is a kind of slope analysis method from mesoscopic perspective so it can present more detail of the mesoscopic property of the granular slope. In the respect of macro scale, the spatial distribution of the stability of the granular slope is in agreement with the theoretical solution. PMID:28772596

Safety improvement from edge lines on rural two-lane highways : tech summary.

DOT National Transportation Integrated Search

2012-01-01

The previous study "Impact of Edge Lines on Safety of Rural Two-Lane Highways" completed in 2005 concluded that, : with edge lines, centralization of a vehicle's position is more apparent during nighttime, which reduces the risk of runoff : -road (RO...

Modelling of Field-Reversed Configuration Experiment with Large Safety Factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinhauer, L; Guo, H; Hoffman, A

2005-11-28

The Translation-Confinement-Sustainment facility has been operated in the 'translation-formation' mode in which a plasma is ejected at high-speed from a {theta}-pinch-like source into a confinement chamber where it settles into a field-reversed-configuration state. Measurements of the poloidal and toroidal field have been the basis of modeling to infer the safety factor. It is found that the edge safety factor exceeds two, and that there is strong forward magnetic shear. The high-q arises because the large elongation compensates for the modest ratio of toroidal-to-poloidal field in the plasma. This is the first known instance of a very high-{beta} plasma with amore » safety factor greater than unity. Two-fluid modeling of the measurements also indicate several other significant features: a broad 'transition layer' at the plasma boundary with probable line-tying effects, complex high-speed flows, and the appearance of a two-fluid minimum-energy state in the plasma core. All these features may contribute to both the stability and good confinement of the plasma.« less

Safety improvement from edge lines on rural two-lane highways (with three-years before and one-year after crash data analysis).

DOT National Transportation Integrated Search

2012-04-01

The previous study Impact of Edge Lines on Safety of Rural Two-Lane Highways completed in 2005 concluded: with edge lines, centralization of vehicles positions is more apparent during night time, which reduces the risk of run-off road (ROR) and he...

Dedication of emergency diesel generators` control air subsystem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harrington, M.; Myers, G.; Palumbo, M.

1994-12-31

In the spring of 1993, the need to upgrade Seabrook Station`s emergency diesel generators` (EDGs`) control air system from nonsafety related to safety related was identified. This need was identified as a result of questions raised by the US Nuclear Regulatory Commission, which was conducting an Electrical Distribution Safety Functional Inspection at Seabrook at that time. The specific reason for the reassignment of safety classification was recognition that failure of the control air supply to the EDGs` jacket cooling water temperature control valves could cause overcooling of the EDGs, which potentially could result in EDG failure during long-term operation. Thismore » paper addresses how the installed control air system was upgraded to safety related using Seabrook`s Commercial Grade Dedication (CGD) Program and how, by using the dedication skills obtained over the past few years, it was done at minimal cost.« less

Pilot Construction Project for Granular Shoulder Stabilization

DOT National Transportation Integrated Search

2013-09-30

Granular shoulders need to be maintained on a regular basis because edge ruts and potholes develop, posing a safety hazard to motorists. The successful mitigation of edge-rut issues for granular shoulders would increase safety and reduce the number o...

Exploring the mechanisms of vehicle front-end shape on pedestrian head injuries caused by ground impact.

PubMed

Yin, Sha; Li, Jiani; Xu, Jun

2017-09-01

In pedestrian-vehicle accidents, pedestrians typically suffer from secondary impact with the ground after the primary contact with vehicles. However, information about the fundamental mechanism of pedestrian head injury from ground impact remains minimal, thereby hindering further improvement in pedestrian safety. This study addresses this issue by using multi-body modeling and computation to investigate the influence of vehicle front-end shape on pedestrian safety. Accordingly, a simulation matrix is constructed to vary bonnet leading-edge height, bonnet length, bonnet angle, and windshield angle. Subsequently, a set of 315 pedestrian-vehicle crash simulations are conducted using the multi-body simulation software MADYMO. Three vehicle velocities, i.e., 20, 30, and 40km/h, are set as the scenarios. Results show that the top governing factor is bonnet leading-edge height. The posture and head injury at the instant of head ground impact vary dramatically with increasing height because of the significant rise of the body bending point and the movement of the collision point. The bonnet angle is the second dominant factor that affects head-ground injury, followed by bonnet length and windshield angle. The results may elucidate one of the critical barriers to understanding head injury caused by ground impact and provide a solid theoretical guideline for considering pedestrian safety in vehicle design. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of edge lines on safety of rural two-lane highways.

DOT National Transportation Integrated Search

2005-10-01

This report documents the results of the project for Impact of Edge Lines on Safety of Rural Two Lane Highways. This research project was initiated in the effort of compliance with the updated version of the Manual on Uniform Traffic Control De...

Mortality after percutaneous edge-to-edge mitral valve repair: a contemporary review.

PubMed

Kortlandt, Friso A; de Beenhouwer, Thomas; Swaans, Martin J; Post, Marco C; van der Heyden, Jan A S; Eefting, Frank D; Rensing, Benno J W M

2016-04-01

Percutaneous edge-to-edge mitral valve (MV) repair is a relatively new treatment option for mitral regurgitation (MR). After the feasibility and safety having been proved in low-surgical-risk patients, the use of this procedure has shifted more to the treatment of high-risk patients. With the absence of randomized controlled trials (RCT) for this particular subgroup, observational studies try to add evidence to the safety aspect of this procedure. These also provide short- and mid-term mortality figures. Several mortality predictors have been identified, which may help the optimal selection of patients who will benefit most from this technique. In this article we provide an overview of the literature about mortality and its predictors in patients treated with the percutaneous edge-to-edge device.

A graph model for preventing railway accidents based on the maximal information coefficient

NASA Astrophysics Data System (ADS)

Shao, Fubo; Li, Keping

2017-01-01

A number of factors influences railway safety. It is an important work to identify important influencing factors and to build the relationship between railway accident and its influencing factors. The maximal information coefficient (MIC) is a good measure of dependence for two-variable relationships which can capture a wide range of associations. Employing MIC, a graph model is proposed for preventing railway accidents which avoids complex mathematical computation. In the graph, nodes denote influencing factors of railway accidents and edges represent dependence of the two linked factors. With the increasing of dependence level, the graph changes from a globally coupled graph to isolated points. Moreover, the important influencing factors are identified from many factors which are the monitor key. Then the relationship between railway accident and important influencing factors is obtained by employing the artificial neural networks. With the relationship, a warning mechanism is built by giving the dangerous zone. If the related factors fall into the dangerous zone in railway operations, the warning level should be raised. The built warning mechanism can prevent railway accidents and can promote railway safety.

Sustained high βN plasmas on EAST tokamak

NASA Astrophysics Data System (ADS)

Gao, Xiang; the EAST team

2018-05-01

Sustained high normalized beta (βN ∼ 1.9) plasmas with an ITER-like tungsten divertor have been achieved on EAST tokamak recently. The high power NBI heating system of 4.8 MW and the 4.6 GHz lower hybrid wave of 1 MW were developed and applied to produce edge and internal transport barriers in high βN discharges. The central flat q profile with q (ρ) ∼ 1 at ρ < 0.3 region and edge safety factor q95 = 4.7 is identified by the multi-channel far-infrared laser polarimeter and the EFIT code. The fraction of non-inductive current is about 40%. The relation between fishbone activity and ITB formation is observed and discussed.

16 CFR 1211.12 - Requirements for edge sensors.

Code of Federal Regulations, 2010 CFR

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...

Tokamak Operation with Safety Factor q 95 < 2 via Control of MHD Stability

DOE PAGES

Piovesan, Paolo; Hanson, Jeremy M.; Martin, Piero; ...

2014-07-24

Magnetic feedback control of the resistive-wall mode has enabled DIII-D to access stable operation at safety factor q95 = 1:9 in divertor plasmas for 150 instability growth times. Magnetohydrodynamic stability sets a hard, disruptive limit on the minimum edge safety factor achievable in a tokamak, or on the maximum plasma current at given toroidal magnetic eld. In tokamaks with a divertor, the limit occurs at q95 = 2, as con rmed in DIII-D. Since the energy con cement time scales linearly with current, this also bounds the performance of a fusion reactor. DIII-D has overcome this limit, opening a wholemore » new high-current regime not accessible before. This result brings signi cant possible bene ts in terms of fusion performance, but it also extends resistive wall mode physics and its control to conditions never explored before. In present experiments, q95 < 2 operation is eventually halted by voltage limits reached in the feedback power supplies, not by intrinsic physics issues. Improvements to power supplies and to control algorithms have the potential to further extend this regime.« less

Impact of toroidal and poloidal mode spectra on the control of non-axisymmetric fields in tokamaks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lanctot, Matthew J.; Park, J. -K.; Piovesan, Paolo

In several tokamaks, non-axisymmetric magnetic field studies show that applied magnetic fields with a toroidal harmonic n = 2 can lead to disruptive n = 1 locked modes. In Ohmic plasmas, n = 2 magnetic reconnection thresholds in otherwise stable discharges are readily accessed at edge safety factors q ~ 3, low density, and low rotation. Similar to previous studies with n = 1 fields, the thresholds are correlated with the “overlap” field computed with the IPEC code. The overlap field quantifies the plasma-mediated coupling of the external field to the resonant field. Remarkably, the “critical overlap fields” at whichmore » magnetic islands form are similar for applied n =1 and 2 fields. The critical overlap field increases with plasma density and edge safety factor but is independent of the toroidal field. Poloidal harmonics m > nq dominate the drive for resonant fields while m < nq harmonics have a negligible impact. This contrasts with previous results in H-mode discharges at high plasma pressure in which the toroidal angular momentum is sensitive to low poloidal harmonics. Altogether, these results highlight unique requirements for n > 1 field control including the need for multiple rows of coils to control selected plasma parameters for specific functions (e.g., rotation control or ELM suppression).« less

Impact of toroidal and poloidal mode spectra on the control of non-axisymmetric fields in tokamaks

DOE PAGES

Lanctot, Matthew J.; Park, J. -K.; Piovesan, Paolo; ...

2017-05-18

In several tokamaks, non-axisymmetric magnetic field studies show that applied magnetic fields with a toroidal harmonic n = 2 can lead to disruptive n = 1 locked modes. In Ohmic plasmas, n = 2 magnetic reconnection thresholds in otherwise stable discharges are readily accessed at edge safety factors q ~ 3, low density, and low rotation. Similar to previous studies with n = 1 fields, the thresholds are correlated with the “overlap” field computed with the IPEC code. The overlap field quantifies the plasma-mediated coupling of the external field to the resonant field. Remarkably, the “critical overlap fields” at whichmore » magnetic islands form are similar for applied n =1 and 2 fields. The critical overlap field increases with plasma density and edge safety factor but is independent of the toroidal field. Poloidal harmonics m > nq dominate the drive for resonant fields while m < nq harmonics have a negligible impact. This contrasts with previous results in H-mode discharges at high plasma pressure in which the toroidal angular momentum is sensitive to low poloidal harmonics. Altogether, these results highlight unique requirements for n > 1 field control including the need for multiple rows of coils to control selected plasma parameters for specific functions (e.g., rotation control or ELM suppression).« less

Verification of voltage/frequency requirement for emergency diesel generator in nuclear power plant using dynamic modeling

NASA Astrophysics Data System (ADS)

Hur, Jin-Suk; Roh, Myung-Sub

2014-02-01

One major cause of the plant shutdown is the loss of electrical power. The study is to comprehend the coping action against station blackout including emergency diesel generator, sequential loading of safety system and to ensure that the emergency diesel generator should meet requirements, especially voltage and frequency criteria using modeling tool. This paper also considered the change of the sequencing time and load capacity only for finding electrical design margin. However, the revision of load list must be verified with safety analysis. From this study, it is discovered that new load calculation is a key factor in EDG localization and in-house capability increase.

Operation in low edge safety factor regime and passive disruption avoidance due to stellarator rotational transform in the Compact Toroidal Hybrid

NASA Astrophysics Data System (ADS)

Pandya, M. D.; Ennis, D. A.; Hartwell, G. J.; Maurer, D. A.

2015-11-01

Low edge safety factor operation at a value less than two (q (a) = 1 /ttot (a) < 2) is routine on the Compact Toroidal Hybrid device. Presently, the operational space of this current carrying stellarator extends down to q (a) = 1 . 2 without significant n = 1 kink mode activity after the initial plasma current rise of the discharge. The disruption dynamics of these low q (a) plasmas depend upon the fraction of rotational transform produced by external stellarator coils to that generated by the plasma current. We observe that when about 10% of the total rotational transform is supplied by the stellarator coils, low q (a) disruptions are passively suppressed and avoided even though q (a) < 2 . When the plasma does disrupt, the instability precursors measured and implicated as the cause are internal tearing modes with poloidal, m, and toroidal, n, mode numbers of m / n = 3 / 2 and 4 / 3 observed by external magnetic sensors, and m / n = 1 / 1 activity observed by core soft x-ray emissivity measurements. Even though q (a) passes through and becomes much less than two, external n = 1 kink mode activity does not appear to play a significant role in the observed disruption phenomenology. This work is supported by US Department of Energy Grant No. DE-FG02-00ER54610.

Experimental investigation of density behaviors in front of the lower hybrid launcher in experimental advanced superconducting tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, L.; Ding, B. J.; Li, M. H.

2013-06-15

A triple Langmuir probe is mounted on the top of the Lower Hybrid (LH) antenna to measure the electron density near the LH grills in Experimental Advanced Superconducting Tokamak. In this work, the LH power density ranges from 2.3 MWm{sup −2} to 10.3 MWm{sup −2} and the rate of puffing gas varies from 1.7 × 10{sup 20} el/s to 14 × 10{sup 20} el/s. The relation between the edge density (from 0.3 × n{sub e-cutoff} to 20 × n{sub e-cutoff}, where n{sub e-cutoff} is the cutoff density, n{sub e-cutoff} = 0.74 × 10{sup 17} m{sup −3} for 2.45 GHz lowermore » hybrid current drive) near the LH grill and the LH power reflection coefficients is investigated. The factors, including the gap between the LH grills and the last closed magnetic flux surface, line-averaged density, LH power, edge safety factor, and gas puffing, are analyzed. The experiments show that injection of LH power is beneficial for increasing edge density. Gas puffing is beneficial for increasing grill density but excess gas puffing is unfavorable for coupling and current drive.« less

Nutrigenomics: the cutting edge and Asian perspectives.

PubMed

Kato, Hisanori

2008-01-01

One of the two major goals of nutrigenomics is to make full use of genomic information to reveal how genetic variations affect nutrients and other food factors and thereby realize tailor-made nutrition (nutrigenetics). The other major goal of nutrigenomics is to comprehensively understand the response of the body to diets and food factors through various 'omics' technologies such as transcriptomics, proteomics, and metabolomics. The most successfully exploited technology to date is transcriptome analysis, due mainly to its efficiency and high-throughput feature. This technology has already provided a substantial amount of data on, for instance, the novel function of food factors, the unknown mechanism of the effect of nutrients, and even safety issues of foods. The nutrigenomics database that we have created now holds the publication data of several hundred of such 'omics' studies. Furthermore, the transcriptomics approach is being applied to food safety issues. For ex-ample, the data we have obtained thus far suggest that this new technology will facilitate the safety evaluation of newly developed foods and will help clarify the mechanism of toxic effects resulting from the excessive intake of a nutrient. The 'omics' data accumulated by our group and others strongly support the promise of the systems biology approach to food and nutrition science.

Carbon microgranule injection into NSTX-U discharges for edge diagnostic research

NASA Astrophysics Data System (ADS)

Lunsford, Robert; Roquemore, A. Lane; Scotti, Filippo; Mansfield, Dennis; Bortolon, Alessandro; Kaita, Robert; Maingi, Rajesh

2016-10-01

Microgranule injection is a versatile means for investigating edge plasmas in fusion devices. Employing a dual bladed rotary turbine, carbon microgranules ranging in diameter from 300 - 700 microns are radially injected into NSTX-U discharges at approximately 50 m/sec. Utilizing multiple high speed camera views, a 3D reconstruction of the injection geometry is created which characterizes the ablation rate and granule trajectory. By coupling this with a neutral gas shielding (NGS) ablation model, the granule mass deposition profile can be determined. Simulation projects a depositional barycenter near the pedestal shoulder for H-mode discharges, and 20 cm inboard of the LCFS for L-mode discharges. Spectroscopic measurements of this localized particle source can be used to characterize impurity transport within the discharge, and potentially allows for direct measurement of the safety factor profile (q). In addition, the transient pressure peaking resultant from injection into H-mode plasmas can also result in the prompt triggering of an edge localized mode (ELM). Work supported by DOE Contract No. DE-AC02-09CH11466.

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

DOE PAGES

Garofalo, Andrea M.; Burrell, Keith H.; Eldon, David; ...

2015-05-26

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 similar 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,more » 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. Here, the DIII-D results are in excellent agreement with these predictions, and nonlinear MHD 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.« less

Fully Nonlinear Edge Gyrokinetic Simulations of Kinetic Geodesic-Acoustic Modes and Boundary Flows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, X Q; Belli, E; Bodi, K

We present edge gyrokinetic neoclassical simulations of tokamak plasmas using the fully nonlinear (full-f) continuum code TEMPEST. A nonlinear Boltzmann model is used for the electrons. The electric field is obtained by solving the 2D gyrokinetic Poisson Equation. We demonstrate the following: (1) High harmonic resonances (n > 2) significantly enhance geodesic-acoustic mode (GAM) damping at high-q (tokamak safety factor), and are necessary to explain both the damping observed in our TEMPEST q-scans and experimental measurements of the scaling of the GAM amplitude with edge q{sub 95} in the absence of obvious evidence that there is a strong q dependencemore » of the turbulent drive and damping of the GAM. (2) The kinetic GAM exists in the edge for steep density and temperature gradients in the form of outgoing waves, its radial scale is set by the ion temperature profile, and ion temperature inhomogeneity is necessary for GAM radial propagation. (3) The development of the neoclassical electric field evolves through different phases of relaxation, including GAMs, their radial propagation, and their long-time collisional decay. (4) Natural consequences of orbits in the pedestal and scrape-off layer region in divertor geometry are substantial non-Maxwellian ion distributions and flow characteristics qualitatively like those observed in experiments.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garofalo, Andrea M.; Burrell, Keith H.; Eldon, David

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 similar 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,more » 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. Here, the DIII-D results are in excellent agreement with these predictions, and nonlinear MHD 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.« less

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

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 9 2014-07-01 2014-07-01 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...

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

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 9 2013-07-01 2013-07-01 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...

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

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 9 2012-07-01 2012-07-01 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...

29 CFR 1926.760 - Fall protection.

Code of Federal Regulations, 2013 CFR

2013-07-01

... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.760 Fall protection. (a... a steel erection activity who is on a walking/working surface with an unprotected side or edge more.... (2) Perimeter safety cables. On multi-story structures, perimeter safety cables shall be installed at...

29 CFR 1926.760 - Fall protection.

Code of Federal Regulations, 2014 CFR

2014-07-01

... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.760 Fall protection. (a... a steel erection activity who is on a walking/working surface with an unprotected side or edge more.... (2) Perimeter safety cables. On multi-story structures, perimeter safety cables shall be installed at...

29 CFR 1926.760 - Fall protection.

Code of Federal Regulations, 2011 CFR

2011-07-01

... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.760 Fall protection. (a... a steel erection activity who is on a walking/working surface with an unprotected side or edge more.... (2) Perimeter safety cables. On multi-story structures, perimeter safety cables shall be installed at...

29 CFR 1926.760 - Fall protection.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.760 Fall protection. (a... a steel erection activity who is on a walking/working surface with an unprotected side or edge more.... (2) Perimeter safety cables. On multi-story structures, perimeter safety cables shall be installed at...

29 CFR 1926.760 - Fall protection.

Code of Federal Regulations, 2010 CFR

2010-07-01

... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Steel Erection § 1926.760 Fall protection. (a... a steel erection activity who is on a walking/working surface with an unprotected side or edge more.... (2) Perimeter safety cables. On multi-story structures, perimeter safety cables shall be installed at...

Magnetic Transport Barriers in the DIII-D Tokamak

NASA Astrophysics Data System (ADS)

Kessler, J.; Volpe, F.; Evans, T. E.; Ali, H.; Punjabi, A.

2009-11-01

Large overlapping magnetic islands generate chaotic fields. However, a previous work [1] showed that second or third order perturbations of special topology and strength can also generate magnetic diffusion ``barriers" in the middle of stochastic regions. In the present study, we numerically assess their experimental feasibility at DIII-D. For this, realistic I- and C-coils perturbations are superimposed on the equilibrium field and puncture plots are generated with a field-line tracer. A criterion is defined for the automatic recognition of barriers and successfully tested on earlier symplectic maps in magnetic coordinates. The criterion is systematically applied to the new puncture plots in search for dependencies, e.g. upon the edge safety factor q95, which might be relevant to edge localized mode (ELM) stability, as well as to assess the robustness of barriers against fluctuations of the plasma parameters and coil currents. 8pt [1] H. Ali and A. Punjabi, Plasma Phys. Control. Fusion 49, 1565 (2007).

Strength evaluation of butt joint by stress intensity factor of small edge crack near interface edge

NASA Astrophysics Data System (ADS)

Sato, T.; Oda, K.; Tsutsumi, N.

2018-06-01

Failure of the bonded dissimilar materials generally initiates near the interface, or just from the interface edge due to the stress singularity at the interface edge. In this study, the stress intensity factor of an edge crack close to the interface between the dissimilar materials is analyzed. The small edge crack is strongly dominated by the singular stress field near the interface edge. The analysis of stress intensity factor of small edge crack near the interface in bi-material and butt joint plates is carried out by changing the length and the location of the crack and the region dominated by the interface edge is examined. It is found that the dimensionless stress intensity factor of small crack, normalized by the singular stress at the crack tip point in the bonded plate without the crack, is equal to 1.12, independent of the material combination and adhesive layer thickness, when the relative crack length with respect to the crack location is less than 0.01. The adhesive strength of the bonded plate with various adhesive layer thicknesses can be expressed as the constant critical stress intensity factor of the small edge crack.

Leading Edge. Volume 7, Number 3. Systems Safety Engineering

DTIC Science & Technology

2010-01-01

solvents during manu- facturing • Toxic gas and noise resulting from weapon firing • Cadmium exposure associated with han- dling of corroded equipment...California • System Safety certificate ◆ University of Southern California • Master of Science degree in Safety Sciences ◆ Indiana University of...Master of Science degree program in Health and Safety, with a Specialization in Occupa- tional Safety Management ◆ Indiana State University, Distance

Evaluation of the breakdown behaviour of ATLAS silicon pixel sensors after partial guard-ring removal

NASA Astrophysics Data System (ADS)

Goessling, C.; Klingenberg, R.; Muenstermann, D.; Wittig, T.

2010-12-01

To avoid geometrical inefficiencies in the ATLAS pixel detector, the concept of shingling is used up to now in the barrel section. For the upgrades of ATLAS, it is desired to avoid this as it increases the volume and material budget of the pixel layers and complicates the cooling. A direct planar edge-to-edge arrangement of pixel modules has not been possible in the past due to about 1100 μm of inactive edge composed of approximately 600 μm of guard rings and 500 μm of safety margin. In this work, the safety margin and guard rings of ATLAS SingleChip sensors were cut at different positions using a standard diamond dicing saw and irradiated afterwards to explore the breakdown behaviour and the leakage current development. It is found that the inactive edge can be reduced to about 400 μm of guard rings with almost no reduction in pre-irradiation testability and leakage current performance. This is in particular important for the insertable b-layer upgrade of ATLAS (IBL) where inactive edges of less than 450 μm width are required.

Magnetic barriers and their q95 dependence at DIII-D

NASA Astrophysics Data System (ADS)

Volpe, F. A.; Kessler, J.; Ali, H.; Evans, T. E.; Punjabi, A.

2012-05-01

It is well known that externally generated resonant magnetic perturbations (RMPs) can form islands in the plasma edge. In turn, large overlapping islands generate stochastic fields, which are believed to play a role in the avoidance and suppression of edge localized modes (ELMs) at DIII-D. However, large coalescing islands can also generate, in the middle of these stochastic regions, KAM surfaces effectively acting as ‘barriers’ against field-line dispersion and, indirectly, particle diffusion. It was predicted in Ali and Punjabi (2007 Plasma Phys. Control. Fusion 49 1565-82) that such magnetic barriers can form in piecewise analytic DIII-D plasma equilibria. In this work, the formation of magnetic barriers at DIII-D is corroborated by field-line tracing calculations using experimentally constrained EFIT (Lao et al 1985 Nucl. Fusion 25 1611) DIII-D equilibria perturbed to include the vacuum field from the internal coils utilized in the experiments. According to these calculations, the occurrence and location of magnetic barriers depend on the edge safety factor q95. It was thus suggested that magnetic barriers might contribute to narrowing the edge stochastic layer and play an indirect role in the RMPs failing to control ELMs for certain values of q95. The analysis of DIII-D discharges where q95 was varied, however, does not show anti-correlation between barrier formation and ELM suppression.

33 CFR 147.815 - ExxonMobil Hoover Floating OCS Facility safety zone.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false ExxonMobil Hoover Floating OCS... Floating OCS Facility safety zone. (a) Description. The ExxonMobil Hoover Floating OCS Facility, Alaminos... (1640.4 feet) from each point on the structure's outer edge is a safety zone. (b) Regulation. No vessel...

Deep sedation versus general anesthesia in percutaneous edge-to-edge mitral valve reconstruction using the MitraClip system.

PubMed

de Waha, Suzanne; Seeburger, Joerg; Ender, Joerg; Desch, Steffen; Eitel, Ingo; Reinhardt, Adrian; Pöss, Janine; Fuernau, Georg; Noack, Thilo; Merk, Denis Rouven; Schuler, Gerhard; Sievers, Hans-Hinrich; Mohr, Friedrich-Wilhelm; Thiele, Holger

2016-06-01

Percutaneous edge-to-edge mitral valve reconstruction (PMVR) has emerged as a treatment option in patients with severe mitral regurgitation not considered suitable candidates for surgery. The majority of PMVR procedures are performed under general anesthesia (GA), although deep sedation (DS) appears to be an attractive alternative. We thus sought to assess the impact on intensive care unit (ICU) length of stay, efficacy, and safety of DS in comparison to GA in patients undergoing PMVR using the MitraClip(®) system. Sixty consecutive patients underwent PMVR procedures at two centers. The first 30 patients were treated by GA followed by 30 patients undergoing DS under different settings. The primary clinical endpoint was ICU length of stay. The primary efficacy endpoint included procedural success and procedural duration. The safety endpoint was defined as a composite of death, stroke, cardiogenic shock, moderate and severe bleeding as well as pneumonia. The ICU length of stay was significantly shorter in the DS group in comparison to GA patients (p = 0.001). The hospital length of stay did not differ following DS in comparison to GA (p = 0.96). Procedural success was high in both groups (100 versus 96.7 %, p = 0.34) at similar procedural duration time (p = 0.60). No difference between GA and DS was observed with respect to the occurrence of the combined safety endpoint (p = 0.47). In comparison to GA, DS reduces the ICU length of stay in PMVR without negative effects on safety and efficacy. Prospective randomized trials are needed to confirm these findings.

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

PubMed

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 < 0.001), the median N-terminal pro-B-type natriuretic peptide decreased by 30% (from 3625 to 2526 pg/mL, P = 0.002), and the quality of life score improved by 16% (decrease of 6 points in the Minnesota Living with Heart Failure Questionnaire score, P = 0.056). The improvements were comparable in patients undergoing isolated TR or combined MR and TR treatment. During follow-up, 8 patients died, 14 were hospitalized for worsening of HF, 2 underwent TV surgery, and 2 received a second TV clip procedure. Transcatheter 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 cross-comparison of different techniques for modeling macro-level cyclist crashes.

PubMed

Guo, Yanyong; Osama, Ahmed; Sayed, Tarek

2018-04-01

Despite the recognized benefits of cycling as a sustainable mode of transportation, cyclists are considered vulnerable road users and there are concerns about their safety. Therefore, it is essential to investigate the factors affecting cyclist safety. The goal of this study is to evaluate and compare different approaches of modeling macro-level cyclist safety as well as investigating factors that contribute to cyclist crashes using a comprehensive list of covariates. Data from 134 traffic analysis zones (TAZs) in the City of Vancouver were used to develop macro-level crash models (CM) incorporating variables related to actual traffic exposure, socio-economics, land use, built environment, and bike network. Four types of CMs were developed under a full Bayesian framework: Poisson lognormal model (PLN), random intercepts PLN model (RIPLN), random parameters PLN model (RPPLN), and spatial PLN model (SPLN). The SPLN model had the best goodness of fit, and the results highlighted the significant effects of spatial correlation. The models showed that the cyclist crashes were positively associated with bike and vehicle exposure measures, households, commercial area density, and signal density. On the other hand, negative associations were found between cyclist crashes and some bike network indicators such as average edge length, average zonal slope, and off-street bike links. Copyright © 2018 Elsevier Ltd. All rights reserved.

Percutaneous edge-to-edge mitral valve repair in high-surgical-risk patients: do we hit the target?

PubMed

Van den Branden, Ben J L; Swaans, Martin J; Post, Martijn C; Rensing, Benno J W M; Eefting, Frank D; Jaarsma, Wybren; Van der Heyden, Jan A S

2012-01-01

This study sought to assess the feasibility and safety of percutaneous edge-to-edge mitral valve (MV) repair in patients with an unacceptably high operative risk. MV repair for mitral regurgitation (MR) can be accomplished by use of a clip that approximates the free edges of the mitral leaflets. All patients were declined for surgery because of a high logistic EuroSCORE (>20%) or the presence of other specific surgical risk factors. Transthoracic echocardiography was performed before and 6 months after the procedure. Differences in New York Heart Association (NYHA) functional class, quality of life (QoL) using the Minnesota questionnaire, and 6-min walk test (6-MWT) distances were reported. Fifty-five procedures were performed in 52 patients (69.2% male, age 73.2 ± 10.1 years, logistic EuroSCORE 27.1 ± 17.0%). In 3 patients, partial clip detachment occurred; a second clip was placed successfully. One patient experienced cardiac tamponade. Two patients developed inguinal bleeding, of whom 1 needed surgery. Six patients (11.5%) died during 6-month follow-up (5 patients as a result of progressive heart failure and 1 noncardiac death). The MR grade before repair was ≥3 in 100%; after 6 months, a reduction in MR grade to ≤2 was present in 79% of the patients. Left ventricular (LV) end-diastolic diameter, LV ejection fraction, and systolic pulmonary artery pressure improved significantly. Accompanied improvements in NYHA functional class, QoL index, 6-MWT distances, and log N-terminal pro-B-type natriuretic peptide were observed. In a high-risk population, MR reduction can be achieved by percutaneous edge-to-edge valve repair, resulting in LV remodeling with improvement of functional capacity after 6 months. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

33 CFR 147.841 - Atlantis Semi-Submersible safety zone.

Code of Federal Regulations, 2010 CFR

2010-07-01

... safety zone. (a) Description. Atlantis Semi-Submersible, Green Canyon 787 (GC 787), located at position 27°11′44″ N, 90°01′37″ W. The area within 500 meters (1640.4 feet) from each point on the structure's outer edge is a safety zone. These coordinates are based upon [NAD 83]. (b) Regulation. No vessel may...

Improved scatterer property estimates from ultrasound backscatter for small gate lengths using a gate-edge correction factor

NASA Astrophysics Data System (ADS)

Oelze, Michael L.; O'Brien, William D.

2004-11-01

Backscattered rf signals used to construct conventional ultrasound B-mode images contain frequency-dependent information that can be examined through the backscattered power spectrum. The backscattered power spectrum is found by taking the magnitude squared of the Fourier transform of a gated time segment corresponding to a region in the scattering volume. When a time segment is gated, the edges of the gated regions change the frequency content of the backscattered power spectrum due to truncating of the waveform. Tapered windows, like the Hanning window, and longer gate lengths reduce the relative contribution of the gate-edge effects. A new gate-edge correction factor was developed that partially accounted for the edge effects. The gate-edge correction factor gave more accurate estimates of scatterer properties at small gate lengths compared to conventional windowing functions. The gate-edge correction factor gave estimates of scatterer properties within 5% of actual values at very small gate lengths (less than 5 spatial pulse lengths) in both simulations and from measurements on glass-bead phantoms. While the gate-edge correction factor gave higher accuracy of estimates at smaller gate lengths, the precision of estimates was not improved at small gate lengths over conventional windowing functions. .

Omics, microbial modeling, and food safety information infrastructure: a food safety perspective

USDA-ARS?s Scientific Manuscript database

Over the last three decades, advances in a variety of cutting-edge “omics” technologies, including genomics, proteomics, and metabolomics, as well as in molecular and mathematical modeling approaches have provided the ability to more easily determine and interpret the mechanisms underlying pathogene...

16 CFR 1750.5 - Detailed requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Detailed requirements. 1750.5 Section 1750.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION REFRIGERATOR SAFETY ACT REGULATIONS STANDARD FOR... directed perpendicularly to the plane of the door and applied anywhere along the latch edge of the inside...

33 CFR 147.837 - Marco Polo Tension Leg Platform safety zone.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Platform safety zone. (a) Description. Marco Polo Tension Leg Platform, Green Canyon 608 (GC 608), located at position 27°21′43.32″ N, 90°10′53.01″ W. The area within 500 meters (1640.4 feet) from each point on the structure's outer edge is a safety zone. These coordinates are based upon [NAD 83]. (b...

33 CFR 147.819 - Allegheny Tension Leg Platform safety zone.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Platform safety zone. (a) Description. The Allegheny Tension Leg Platform (Allegheny TLP), Green Canyon Block 254A (GC 254A), is located at position 27°41′29.65″ N, 90°16′31.93″ W. The area within 500 meters (1640.4 feet) from each point on the structure's outer edge is a safety zone. (b) Regulation. No vessel...

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

Treesearch

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...

Dynamics of kinetic geodesic-acoustic modes and the radial electric field in tokamak neoclassical plasmas

NASA Astrophysics Data System (ADS)

Xu, X. Q.; Belli, E.; Bodi, K.; Candy, J.; Chang, C. S.; Cohen, R. H.; Colella, P.; Dimits, A. M.; Dorr, M. R.; Gao, Z.; Hittinger, J. A.; Ko, S.; Krasheninnikov, S.; McKee, G. R.; Nevins, W. M.; Rognlien, T. D.; Snyder, P. B.; Suh, J.; Umansky, M. V.

2009-06-01

We present edge gyrokinetic simulations of tokamak plasmas using the fully non-linear (full-f) continuum code TEMPEST. A non-linear Boltzmann model is used for the electrons. The electric field is obtained by solving the 2D gyrokinetic Poisson equation. We demonstrate the following. (1) High harmonic resonances (n > 2) significantly enhance geodesic-acoustic mode (GAM) damping at high q (tokamak safety factor), and are necessary to explain the damping observed in our TEMPEST q-scans and consistent with the experimental measurements of the scaling of the GAM amplitude with edge q95 in the absence of obvious evidence that there is a strong q-dependence of the turbulent drive and damping of the GAM. (2) The kinetic GAM exists in the edge for steep density and temperature gradients in the form of outgoing waves, its radial scale is set by the ion temperature profile, and ion temperature inhomogeneity is necessary for GAM radial propagation. (3) The development of the neoclassical electric field evolves through different phases of relaxation, including GAMs, their radial propagation and their long-time collisional decay. (4) Natural consequences of orbits in the pedestal and scrape-off layer region in divertor geometry are substantial non-Maxwellian ion distributions and parallel flow characteristics qualitatively like those observed in experiments.

Ubiquitous Stereo Vision for Controlling Safety on Platforms in Railroad Station

NASA Astrophysics Data System (ADS)

Yoda, Ikushi; Hosotani, Daisuke; Sakaue, Katushiko

Dozens of people are killed every year when they fall off of train platforms, making this an urgent issue to be addressed by the railroads, especially in the major cities. This concern prompted the present work that is now in progress to develop a Ubiquitous Stereo Vision based system for safety management at the edge of rail station platforms. In this approach, a series of stereo cameras are installed in a row on the ceiling that are pointed downward at the edge of the platform to monitor the disposition of people waiting for the train. The purpose of the system is to determine automatically and in real-time whether anyone or anything is in the danger zone at the very edge of the platform, whether anyone has actually fallen off the platform, or whether there is any sign of these things happening. The system could be configured to automatically switch over to a surveillance monitor or automatically connect to an emergency brake system in the event of trouble.

Optimum Material Composition for Minimizing the Stress Intensity Factor of Edge Crack in Thick-Walled FGM Circular Pipes Under Thermomechanical Loading

NASA Astrophysics Data System (ADS)

Sekine, Hideki; Yoshida, Kimiaki

This paper deals with the optimization problem of material composition for minimizing the stress intensity factor of radial edge crack in thick-walled functionally graded material (FGM) circular pipes under steady-state thermomechanical loading. Homogenizing the FGM circular pipes by simulating the inhomogeneity of thermal conductivity by a distribution of equivalent eigentemperature gradient and the inhomogeneity of Young's modulus and Poisson's ratio by a distribution of equivalent eigenstrain, we present an approximation method to obtain the stress intensity factor of radial edge crack in the FGM circular pipes. The optimum material composition for minimizing the stress intensity factor of radial edge crack is determined using a nonlinear mathematical programming method. Numerical results obtained for a thick-walled TiC/Al2O3 FGM circular pipe reveal that it is possible to decrease remarkably the stress intensity factor of radial edge crack by setting the optimum material composition profile.

Inverted edge effects on carbon stocks in human-dominated landscapes

NASA Astrophysics Data System (ADS)

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.

ELM mitigation studies in JET and implications for ITER

NASA Astrophysics Data System (ADS)

de La Luna, Elena

2009-11-01

Type I edge localized modes (ELMs) remain a serious concern for ITER because of the high transient heat and particle flux that can lead to rapid erosion of the divertor plates. This has stimulated worldwide research on exploration of different methods to avoid or at least mitigate the ELM energy loss while maintaining adequate confinement. ITER will require reliable ELM control over a wide range of operating conditions, including changes in the edge safety factor, therefore a suite of different techniques is highly desirable. In JET several techniques have been demonstrated for control the frequency and size of type I ELMs, including resonant perturbations of the edge magnetic field (RMP), ELM magnetic triggering by fast vertical movement of the plasma column (``vertical kicks'') and ELM pacing using pellet injection. In this paper we present results from recent dedicated experiments in JET focusing on integrating the different ELM mitigation methods into similar plasma scenarios. Plasma parameter scans provide comparison of the performance of the different techniques in terms of both the reduction in ELM size and on the impact of each control method on plasma confinement. The compatibility of different ELM mitigation schemes has also been investigated. The plasma response to RMP and vertical kicks during the ELM mitigation phase shares common features: the reduction in ELM size (up to a factor of 3) is accompanied by a reduction in pedestal pressure (mainly due to a loss of density) with only minor (< 10%) reduction of the stored energy. Interestingly, it has been found that the combined application of RMP and kicks leads to a reduction of the threshold perturbation level (vertical displacement in the case of the kicks) necessary for the ELM mitigation to occur. The implication of these results for ITER will be discussed.

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

NASA Astrophysics Data System (ADS)

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.

Passive MHD Spectroscopy for Enabling Magnetic Reconstructions on Spherical Tokamak Plasmas at General Fusion Inc

NASA Astrophysics Data System (ADS)

O'Shea, Peter; Laberge, Michel; Mossman, Alex; Reynolds, Meritt

2017-10-01

Magnetic reconstructions on lab based plasma injectors at General Fusion relies heavily on edge magnetic (``Bdot'') probes. On plasma experiments built for field compression (PCS) tests, the number and locations of Bdot probes is limited by mechanical constraints. Additional information about the q profiles near the core in our Spector plasmas is obtained using passive MHD spectroscopy. The coaxial helicity injection (CHI) formation process naturally generates hollow current profiles and reversed shear early in each discharge. Central Ohmic heating naturally peaks the current profiles as our plasmas evolve in time, simultaneously reducing the core safety factor, q(0), and reverse shear. As the central, non-monotonic q-profile crosses rational flux surfaces, we observe transient magnetic reconnection events (MRE's) due to the double tearing mode. Modal analysis allows us to infer the q surfaces involved in each burst. The parametric dependence of the timing of MRE's allows us to estimate the continuous time evolution of the core q profile. Combining core MHD spectroscopy with edge magnetic probe measurements greatly enhances our certainty of the overall q profile.

Theoretical model of the plasma edge. II. Transport along the open field lines of a magnetic island belt associated with the ionization instability

NASA Astrophysics Data System (ADS)

Rogister, A. L. M.; Hasselberg, G.

1993-12-01

For pt.I, see ibid, p.1799-1816 (1993). To the ionization instability described in Part I correspond odd phi, even br eigenfunctions leading, as for the tearing mode, to a magnetic island belt centred about the rational magnetic surface q = m < qa (q is the safety factor; m is the mode number). Plasma dumping on the target plates, along the island magnetic field lines, releases the neutrals, the ionization of which drives the instability. This self-consistent model of the plasma edge yields the electron temperature on the last closed equilibrium magnetic surface and the particle confinement time, which are compared with the values measured in TEXTOR and other tokamaks; interestingly, the value obtained for τp is very reminiscent of the heuristic energy confinement time expression proposed by Kaye and Goldston(1985). Theory also predicts an equilibrium bifurcation at high power, corresponding to a reduction, and then a collapse, of the island width. The hypothesis that the (L mode) island belt be hooked up to the machine's structure is briefly discussed

Geology and land use

USGS Publications Warehouse

Brown, R.D.

1990-01-01

The geologic limitations for building sites of some areas can be overcome, in part, by skilled engineering and expensive construction practices. But the costs can be prohibitively high, and the solutions are not always completely effective. In "earthquake country," history has shown that costs are highest and risk factors most uncertain in a few easily recognized settings: unstable hill sloped, land at the edge of rapidly eroding sea cliffs, lowlands underlain by saturated estuarine mud of ill, and areas near faults capable of producing magnitude 7 or greater earthquakes. Safety immediately after an earthquake is also a concern in these places, for extreme damage and ground distortion may impede or prevent timely access by emergency equipment. 

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

Treesearch

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...

Design study of the geometry of the blanking tool to predict the burr formation of Zircaloy-4 sheet

NASA Astrophysics Data System (ADS)

Ha, Jisun; Lee, Hyungyil; Kim, Dongchul; Kim, Naksoo

2013-12-01

In this work, we investigated factors that influence burr formation for zircaloy-4 sheet used for spacer grids of nuclear fuel roads. Factors we considered are geometric factors of punch. We changed clearance and velocity in order to consider the failure parameters, and we changed shearing angle and corner radius of L-shaped punch in order to consider geometric factors of punch. First, we carried out blanking test with failure parameter of GTN model using L-shaped punch. The tendency of failure parameters and geometric factors that affect burr formation by analyzing sheared edges is investigated. Consequently, geometric factor's influencing on the burr formation is also high as failure parameters. Then, the sheared edges and burr formation with failure parameters and geometric factors is investigated using FE analysis model. As a result of analyzing sheared edges with the variables, we checked geometric factors more affect burr formation than failure parameters. To check the reliability of the FE model, the blanking force and the sheared edges obtained from experiments are compared with the computations considering heat transfer.

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

PubMed

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.

Experimental studies of high-confinement mode plasma response to non-axisymmetric magnetic perturbations in ASDEX Upgrade

NASA Astrophysics Data System (ADS)

Suttrop, W.; Kirk, A.; Nazikian, R.; Leuthold, N.; Strumberger, E.; Willensdorfer, M.; Cavedon, M.; Dunne, M.; Fischer, R.; Fietz, S.; Fuchs, J. C.; Liu, Y. Q.; McDermott, R. M.; Orain, F.; Ryan, D. A.; Viezzer, E.; The ASDEX Upgrade Team; The DIII-D Team; The Eurofusion MST1 Team

2017-01-01

The interaction of externally applied small non-axisymmetric magnetic perturbations (MP) with tokamak high-confinement mode (H-mode) plasmas is reviewed and illustrated by recent experiments in ASDEX Upgrade. The plasma response to the vacuum MP field is amplified by stable ideal kink modes with low toroidal mode number n driven by the H-mode edge pressure gradient (and associated bootstrap current) which is experimentally evidenced by an observable shift of the poloidal mode number m away from field alignment (m  =  qn, with q being the safety factor) at the response maximum. A torque scan experiment demonstrates the importance of the perpendicular electron flow for shielding of the resonant magnetic perturbation, as expected from a two-fluid MHD picture. Two significant effects of MP occur in H-mode plasmas at low pedestal collisionality, ν \\text{ped}\\ast≤slant 0.4 : (a) a reduction of the global plasma density by up to 61 % and (b) a reduction of the energy loss associated with edge localised modes (ELMs) by a factor of up to 9. A comprehensive database of ELM mitigation pulses at low {ν\\ast} in ASDEX Upgrade shows that the degree of ELM mitigation correlates with the reduction of pedestal pressure which in turn is limited and defined by the onset of ELMs, i. e. a modification of the ELM stability limit by the magnetic perturbation.

Rimmed and edge thickened Stodola shaped flywheel

DOEpatents

Kulkarni, S.V.; Stone, R.G.

1983-10-11

A flywheel is described that is useful for energy storage in a hybrid vehicle automotive power system or in some stationary applications. The flywheel has a body composed of essentially planar isotropic high strength material. The flywheel body is enclosed by a rim of circumferentially wound fiber embedded in resin. The rim promotes flywheel safety and survivability. The flywheel has a truncated and edge thickened Stodola shape designed to optimize system mass and energy storage capability. 6 figs.

Rimmed and edge thickened stodola shaped flywheel. [Patent application

DOEpatents

Kulkarni, S.V.; Stone, R.G.

1980-09-24

A flywheel is described that is useful for energy storage in a hybrid vehicle automotive power system or in some stationary applications. The flywheel has a body composed of essentially planar isotropic high strength material. The flywheel body is enclosed by a rim of circumferentially wound fiber embedded in resin. The rim promotes flywheel safety and survivability. The flywheel has a truncated and edge thickened Stodola shape designed to optimize system mass and energy storage capability.

Comparison of safety effect estimates obtained from empirical Bayes before-after study, propensity scores-potential outcomes framework, and regression model with cross-sectional data.

PubMed

Wood, Jonathan S; Donnell, Eric T; Porter, Richard J

2015-02-01

A variety of different study designs and analysis methods have been used to evaluate the performance of traffic safety countermeasures. The most common study designs and methods include observational before-after studies using the empirical Bayes method and cross-sectional studies using regression models. The propensity scores-potential outcomes framework has recently been proposed as an alternative traffic safety countermeasure evaluation method to address the challenges associated with selection biases that can be part of cross-sectional studies. Crash modification factors derived from the application of all three methods have not yet been compared. This paper compares the results of retrospective, observational evaluations of a traffic safety countermeasure using both before-after and cross-sectional study designs. The paper describes the strengths and limitations of each method, focusing primarily on how each addresses site selection bias, which is a common issue in observational safety studies. The Safety Edge paving technique, which seeks to mitigate crashes related to roadway departure events, is the countermeasure used in the present study to compare the alternative evaluation methods. The results indicated that all three methods yielded results that were consistent with each other and with previous research. The empirical Bayes results had the smallest standard errors. It is concluded that the propensity scores with potential outcomes framework is a viable alternative analysis method to the empirical Bayes before-after study. It should be considered whenever a before-after study is not possible or practical. Copyright © 2014 Elsevier Ltd. All rights reserved.

Evaluation of factors affecting the edge formability of two hot rolled multiphase steels

NASA Astrophysics Data System (ADS)

Mukherjee, Monideepa; Tiwari, Sumit; Bhattacharya, Basudev

2018-02-01

In this study, the effect of various factors on the hole expansion ratio and hence on the edge formability of two hot rolled multiphase steels, one with a ferrite-martensite microstructure and the other with a ferrite-bainite microstructure, was investigated through systematic microstructural and mechanical characterization. The study revealed that the microstructure of the steels, which determines their strain hardening capacity and fracture resistance, is the principal factor controlling edge formability. The influence of other factors such as tensile strength, ductility, anisotropy, and thickness, though present, are secondary. A critical evaluation of the available empirical models for hole expansion ratio prediction is also presented.

Lean production design using value stream mapping and ergonomics approach for waste elimination on buffing panel upright process

NASA Astrophysics Data System (ADS)

Suryoputro, M. R.; Sari, A. D.; Burhanudin, R.; Sugarindra, M.

2017-12-01

This study discussed the implementation of ergonomics and value stream mapping issues to reduce the existing waste in the process of buffing upright panel in the XYZ music manufacturing company. Aimed to identify the 9 waste based on the identification in terms of production processes and ergonomic factors, namely environmental health and safety, defects, overproduction, waiting, not utilizing employee knowledge skill and ability, transportation, inventory, motion, and excess process. In addition, ergonomics factors were identified, for example posture using REBA, job safety analysis, and physical workload. This study results indicated that the process is having 21.4% of the potential dangers that could not be accepted and thus potentially lead to lost time. Continued with the physical workload, the score of % cardiovascular load value is still below 30%, which means that the physical workload is normal and allows the addition of work. Meanwhile, in the calculation of posture investigation, the REBA resulted that there was a motion waste identified on the edge buff machine and ryoto with the score of 10 and 8. In conclusion, the results shown that there were 20 overall waste produced, then thus waste were reduced based on the identification and discussion of proposed improvements.

Spin-transfer-torque efficiency enhanced by edge-damage of perpendicular magnetic random access memories

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Kyungmi; Lee, Kyung-Jin, E-mail: kj-lee@korea.ac.kr; Department of Materials Science and Engineering, Korea University, Seoul 136-713

2015-08-07

We numerically investigate the effect of magnetic and electrical damages at the edge of a perpendicular magnetic random access memory (MRAM) cell on the spin-transfer-torque (STT) efficiency that is defined by the ratio of thermal stability factor to switching current. We find that the switching mode of an edge-damaged cell is different from that of an undamaged cell, which results in a sizable reduction in the switching current. Together with a marginal reduction of the thermal stability factor of an edge-damaged cell, this feature makes the STT efficiency large. Our results suggest that a precise edge control is viable formore » the optimization of STT-MRAM.« less

Rimmed and edge thickened Stodola shaped flywheel

DOEpatents

Kulkarni, Satish V.; Stone, Richard G.

1983-01-01

A flywheel (10) is described that is useful for energy storage in a hybrid vehicle automotive power system or in some stationary applications. The flywheel (10) has a body (15) composed of essentially planar isotropic high strength material. The flywheel (10) body (15) is enclosed by a rim (50) of circumferentially wound fiber (2) embedded in resin (3). The rim (50) promotes flywheel (10) safety and survivability. The flywheel (10) has a truncated and edge thickened Stodola shape designed to optimize system mass and energy storage capability.

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

PubMed

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.

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

NASA Astrophysics Data System (ADS)

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 Pu-238 alpha-decay to an array of thermoelectric elements. Each module contains four Pu-238O2-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-TO) plate is approximately 140 m/s.

Theory based scaling of edge turbulence and implications for the scrape-off layer width

NASA Astrophysics Data System (ADS)

Myra, J. R.; Russell, D. A.; Zweben, S. J.

2016-11-01

Turbulence and plasma parameter data from the National Spherical Torus Experiment (NSTX) [Ono et al., Nucl. Fusion 40, 557 (2000)] is examined and interpreted based on various theoretical estimates. In particular, quantities of interest for assessing the role of turbulent transport on the midplane scrape-off layer heat flux width are assessed. Because most turbulence quantities exhibit large scatter and little scaling within a given operation mode, this paper focuses on length and time scales and dimensionless parameters between operational modes including Ohmic, low (L), and high (H) modes using a large NSTX edge turbulence database [Zweben et al., Nucl. Fusion 55, 093035 (2015)]. These are compared with theoretical estimates for drift and interchange rates, profile modification saturation levels, a resistive ballooning condition, and dimensionless parameters characterizing L and H mode conditions. It is argued that the underlying instability physics governing edge turbulence in different operational modes is, in fact, similar, and is consistent with curvature-driven drift ballooning. Saturation physics, however, is dependent on the operational mode. Five dimensionless parameters for drift-interchange turbulence are obtained and employed to assess the importance of turbulence in setting the scrape-off layer heat flux width λq and its scaling. An explicit proportionality of the width λq to the safety factor and major radius (qR) is obtained under these conditions. Quantitative estimates and reduced model numerical simulations suggest that the turbulence mechanism is not negligible in determining λq in NSTX, at least for high plasma current discharges.

Does my step look big in this? A visual illusion leads to safer stepping behaviour.

PubMed

Elliott, David B; Vale, Anna; Whitaker, David; Buckley, John G

2009-01-01

Tripping is a common factor in falls and a typical safety strategy to avoid tripping on steps or stairs is to increase foot clearance over the step edge. In the present study we asked whether the perceived height of a step could be increased using a visual illusion and whether this would lead to the adoption of a safer stepping strategy, in terms of greater foot clearance over the step edge. The study also addressed the controversial question of whether motor actions are dissociated from visual perception. 21 young, healthy subjects perceived the step to be higher in a configuration of the horizontal-vertical illusion compared to a reverse configuration (p = 0.01). During a simple stepping task, maximum toe elevation changed by an amount corresponding to the size of the visual illusion (p<0.001). Linear regression analyses showed highly significant associations between perceived step height and maximum toe elevation for all conditions. The perceived height of a step can be manipulated using a simple visual illusion, leading to the adoption of a safer stepping strategy in terms of greater foot clearance over a step edge. In addition, the strong link found between perception of a visual illusion and visuomotor action provides additional support to the view that the original, controversial proposal by Goodale and Milner (1992) of two separate and distinct visual streams for perception and visuomotor action should be re-evaluated.

Theory based scaling of edge turbulence and implications for the scrape-off layer width

DOE PAGES

Myra, J. R.; Russell, D. A.; Zweben, S. J.

2016-11-01

Turbulence and plasma parameter data from the National Spherical Torus Experiment (NSTX) is examined and interpreted based on various theoretical estimates. In particular, quantities of interest for assessing the role of turbulent transport on the midplane scrape-off layer heat flux width are assessed. Because most turbulence quantities exhibit large scatter and little scaling within a given operation mode, this paper focuses on length and time scales and dimensionless parameters between operational modes including Ohmic, low (L), and high (H) modes using a large NSTX edge turbulence database. These are compared with theoretical estimates for drift and interchange rates, profile modificationmore » saturation levels, a resistive ballooning condition, and dimensionless parameters characterizing L and H mode conditions. It is argued that the underlying instability physics governing edge turbulence in different operational modes is, in fact, similar, and is consistent with curvature-driven drift ballooning. Saturation physics, however, is dependent on the operational mode. Five dimensionless parameters for drift-interchange turbulence are obtained and employed to assess the importance of turbulence in setting the scrape-off layer heat flux width λ q and its scaling. An explicit proportionality of the width λ q to the safety factor and major radius (qR) is obtained under these conditions. Lastly, quantitative estimates and reduced model numerical simulations suggest that the turbulence mechanism is not negligible in determining λ q in NSTX, at least for high plasma current discharges.« less

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

PubMed

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.

Minimizing the Diameter of a Network Using Shortcut Edges

NASA Astrophysics Data System (ADS)

Demaine, Erik D.; Zadimoghaddam, Morteza

We study the problem of minimizing the diameter of a graph by adding k shortcut edges, for speeding up communication in an existing network design. We develop constant-factor approximation algorithms for different variations of this problem. We also show how to improve the approximation ratios using resource augmentation to allow more than k shortcut edges. We observe a close relation between the single-source version of the problem, where we want to minimize the largest distance from a given source vertex, and the well-known k-median problem. First we show that our constant-factor approximation algorithms for the general case solve the single-source problem within a constant factor. Then, using a linear-programming formulation for the single-source version, we find a (1 + ɛ)-approximation using O(klogn) shortcut edges. To show the tightness of our result, we prove that any ({3 over 2}-ɛ)-approximation for the single-source version must use Ω(klogn) shortcut edges assuming P ≠ NP.

Extended use of percutaneous edge-to-edge mitral valve repair beyond EVEREST (Endovascular Valve Edge-to-Edge Repair) criteria: 30-day and 12-month clinical and echocardiographic outcomes from the GRASP (Getting Reduction of Mitral Insufficiency by Percutaneous Clip Implantation) registry.

PubMed

Attizzani, Guilherme F; Ohno, Yohei; Capodanno, Davide; Cannata, Stefano; Dipasqua, Fabio; Immé, Sebastiano; Mangiafico, Sarah; Barbanti, Marco; Ministeri, Margherita; Cageggi, Anna; Pistritto, Anna Maria; Giaquinta, Sandra; Farruggio, Silvia; Chiarandà, Marta; Ronsivalle, Giuseppe; Schnell, Audrey; Scandura, Salvatore; Tamburino, Corrado; Capranzano, Piera; Grasso, Carmelo

2015-01-01

This study sought to compare, in high-risk patients with 3+ to 4+ mitral regurgitation (MR) dichotomized by baseline echocardiographic features, acute, 30-day, and 12-month outcomes following percutaneous mitral valve repair using the MitraClip. The feasibility and mid-term outcomes after MitraClip implantation in patients with echocardiographic features different from the EVEREST (Endovascular Valve Edge-to-Edge Repair) I and II trials have been scarcely studied. Clinical and echocardiographic outcomes through 12-month follow-up of consecutive patients who underwent MitraClip implantation were obtained from an ongoing prospective registry. Two different groups, divided according to baseline echocardiographic criteria (investigational group [EVERESTOFF] and control group [EVERESTON]), were compared. Seventy-eight patients were included in EVERESTOFF and 93 patients in EVERESTON groups. Important and comparable acute reductions in MR and no clip-related complications were revealed. The primary safety endpoint at 30 days was comparable between groups (2.6% vs. 6.5%, respectively, p = 0.204); in addition, MR reduction was mostly sustained, whereas equivalent improvement in New York Heart Association functional class were demonstrated. Kaplan-Meier freedom from death, surgery for mitral valve dysfunction, or grade ≥3+ MR at 12 months was demonstrated in 71.4% and 76.2%, respectively, in the EVERESTOFF and EVERESTON groups (log rank p = 0.378). Significant improvements in ejection fraction and reduction in left ventricle volumes were demonstrated in both groups over time, but the baseline between-group differences were sustained. MitraClip implantation in patients with expanded baseline echocardiographic features, compared with the control group, was associated with similar rates of safety and efficacy through 12-month follow-up. Further validation of our findings is warranted. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

50 CFR 216.254 - Mitigation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... safety for marine mammals with a radius of no less than 5 nm (9.3 km) for single bombs and 10 nm (18.5 km) for double bombs and a buffer zone from the outer edge of the safety zone with a radius of at least 2.5 nm (4.6 km) for single bombs and 5 nm (18.5 km) for double bombs. (b) Prior to a JASSM or SDB...

Home safety - children

MedlinePlus

Take precautions when cooking to prevent burns. Make sure the handles on pots and pans are turned away from the edge of the ... NOT cook while carrying your child. This includes cooking on the stovetop, the oven, or a microwave. ...

Pavement Edge Treatment Final Report

DOT National Transportation Integrated Search

2018-01-01

The New York City Connected Vehicle Pilot aims to improve the safety of travelers and pedestrians in the city through the deployment of connected vehicle technologies. This objective directly aligns with the city's Vision Zero initiative, which began...

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ader, C.; Voirin, E.; McGee, M.

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 formore » 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.« less

"Edge-on" MOSkin detector for stereotactic beam measurement and verification.

PubMed

Jong, Wei Loong; Ung, Ngie Min; Vannyat, Ath; Jamalludin, Zulaikha; Rosenfeld, Anatoly; Wong, Jeannie Hsiu Ding

2017-01-01

Dosimetry in small radiation field is challenging and complicated because of dose volume averaging and beam perturbations in a detector. We evaluated the suitability of the "Edge-on" MOSkin (MOSFET) detector in small radiation field measurement. We also tested the feasibility for dosimetric verification in stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT). "Edge-on" MOSkin detector was calibrated and the reproducibility and linearity were determined. Lateral dose profiles and output factors were measured using the "Edge-on" MOSkin detector, ionization chamber, SRS diode and EBT2 film. Dosimetric verification was carried out on two SRS and five SRT plans. In dose profile measurements, the "Edge-on" MOSkin measurements concurred with EBT2 film measurements. It showed full width at half maximum of the dose profile with average difference of 0.11mm and penumbral width with difference of ±0.2mm for all SRS cones as compared to EBT2 film measurement. For output factor measurements, a 1.1% difference was observed between the "Edge-on" MOSkin detector and EBT2 film for 4mm SRS cone. The "Edge-on" MOSkin detector provided reproducible measurements for dose verification in real-time. The measured doses concurred with the calculated dose for SRS (within 1%) and SRT (within 3%). A set of output correction factors for the "Edge-on" MOSkin detector for small radiation fields were derived from EBT2 film measurement and presented. This study showed that the "Edge-on" MOSkin detector is a suitable tool for dose verification in small radiation field. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Internal and edge cracks in a plate of finite width under bending

NASA Technical Reports Server (NTRS)

Boduroglu, H.; Erdogan, F.

1983-01-01

Internal and edge cracks were studied by using Reissner's transverse shear theory. The effect of stress-free boundaries on the stress intensity factors in plates under bending were investigated. Among the results found, particularly interesting are those relating to the limiting cases of the crack geometries. The numerical results are given for a single internal crack, two collinear cracks, and two edge cracks. The effect of Poisson's ratio on the stress intensity factors was studied.

Decreased Lumbar Lordosis and Deficient Acetabular Coverage Are Risk Factors for Subchondral Insufficiency Fracture.

PubMed

Jo, Woo Lam; Lee, Woo Suk; Chae, Dong Sik; Yang, Ick Hwan; Lee, Kyoung Min; Koo, Kyung Hoi

2016-10-01

Subchondral insufficiency fracture (SIF) of the femoral head occurs in the elderly and recipients of organ transplantation. Osteoporosis and deficient lateral coverage of the acetabulum are known risk factors for SIF. There has been no study about relation between spinopelvic alignment and anterior acetabular coverage with SIF. We therefore asked whether a decrease of lumbar lordosis and a deficiency in the anterior acetabular coverage are risk factors. We investigated 37 patients with SIF. There were 33 women and 4 men, and their mean age was 71.5 years (59-85 years). These 37 patients were matched with 37 controls for gender, age, height, weight, body mass index and bone mineral density. We compared the lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope, acetabular index, acetabular roof angle, acetabular head index, anterior center-edge angle and lateral center-edge angle. Lumbar lordosis, pelvic tilt, sacral slope, lateral center edge angle, anterior center edge angle, acetabular index and acetabular head index were significantly different between SIF group and control group. Lumbar lordosis (OR = 1.11), lateral center edge angle (OR = 1.30) and anterior center edge angle (OR = 1.27) had significant associations in multivariate analysis. Decreased lumbar lordosis and deficient anterior coverage of the acetabulum are risk factors for SIF as well as decreased lateral coverage of the acetabulum.

Finite Element Analysis of the Implantation Process of Overlapping Stents

PubMed Central

Xu, Jiang; Yang, Jie; Sohrabi, Salman; Zhou, Yihua; Liu, Yaling

2017-01-01

Overlapping stents are widely used in vascular stent surgeries. However, the rate of stent fractures (SF) and in-stent restenosis (ISR) after using overlapping stents is higher than that of single stent implantations. Published studies investigating the nature of overlapping stents rely primarily on medical images, which can only reveal the effect of the surgery without providing insights into how stent overlap influences the implantation process. In this paper, a finite element analysis of the overlapping stent implantation process was performed to study the interaction between overlapping stents. Four different cases, based on three typical stent overlap modes and two classical balloons, were investigated. The results showed that overlapping contact patterns among struts were edge-to-edge, edge-to-surface, and noncontact. These were mainly induced by the nonuniform deformation of the stent in the radial direction and stent tubular structures. Meanwhile, the results also revealed that the contact pressure was concentrated in the edge of overlapping struts. During the stent overlap process, the contact pattern was primarily edge-to-edge contact at the beginning and edge-to-surface contact as the contact pressure increased. The interactions between overlapping stents suggest that the failure of overlapping stents frequently occurs along stent edges, which agrees with the previous experimental research regarding the safety of overlapping stents. This paper also provides a fundamental understanding of the mechanical properties of overlapping stents. PMID:28690712

3 CFR 8807 - Proclamation 8807 of May 1, 2012. National Building Safety Month, 2012

Code of Federal Regulations, 2013 CFR

2013-01-01

... and standards, they help save lives and prevent disruption in the wake of disaster. Resilient..., withstand, and recover from disasters. We are drawing upon cutting edge science and technology to establish...

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

PubMed

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; p<0.0001). In both, patients with isolated TV and combined procedures, 6 minute walking distance improved (from 285±118 to 344±81 and 225±113 to 261±130 m, p=0.02 and 0.03, respectively). Predominant anteroseptal or central TR was identified as predictor of procedural success (p=0.025). Edge-to-edge repair of the TV is feasible with promising reduction in TR, which could result in clinical improvement.

KSC-04pd2122

NASA Image and Video Library

2004-10-12

KENNEDY SPACE CENTER, FLA. - In an installation demonstration in the Orbiter Processing Facility, a sensor is placed on the wing leading edge of orbiter Discovery. The sensors are part of the Wing Leading Edge Impact Detection System, a new safety measure added for all future Space Shuttle missions. The system also includes accelerometers that monitor the orbiter's wings for debris impacts during launch and while in orbit. There are 22 temperature sensors and 66 accelerometers on each wing. Sensor data will flow from the wing to the crew compartment, where it will be transmitted to Earth.

KSC-04pd2123

NASA Image and Video Library

2004-10-12

KENNEDY SPACE CENTER, FLA. - In an installation demonstration the Orbiter Processing Facility, a sensor is placed on the wing leading edge of orbiter Discovery. The sensors are part of the Wing Leading Edge Impact Detection System, a new safety measure added for all future Space Shuttle missions. The system also includes accelerometers that monitor the orbiter's wings for debris impacts during launch and while in orbit. There are 22 temperature sensors and 66 accelerometers on each wing. Sensor data will flow from the wing to the crew compartment, where it will be transmitted to Earth.

Wyoming Department of Transportation (WYDOT) road condition reporting application for weather responsive traffic management.

DOT National Transportation Integrated Search

2015-10-01

Federal Highway Administrations (FHWA) Road Weather Management Program (RWMP) strives to promote the development and implementation of cutting-edge techniques for maintaining safety, mobility, and productivity of roadways during adverse weather co...

Michigan Department of Transportation (MDOT) weather responsive traveler information (Wx-TINFO) system implementation project.

DOT National Transportation Integrated Search

2016-01-01

Federal Highway Administrations (FHWA) Road Weather Management Program (RWMP) strives to promote the development and implementation of cutting-edge techniques for maintaining safety, mobility, and productivity of roadways during adverse weather co...

South Dakota Department of Transportation (SDDOT) regional traveler information system for weather responsive traffic management.

DOT National Transportation Integrated Search

2015-11-01

Federal Highway Administrations (FHWA) Road Weather Management Program (RWMP) strives to promote the development and implementation of cutting-edge techniques for maintaining safety, mobility, and productivity of roadways during adverse weather co...

Have pedestrian subsystem tests improved passenger car front shape?

PubMed

Li, Guibing; Wang, Fang; Otte, Dietmar; Cai, Zhihua; Simms, Ciaran

2018-06-01

Subsystem impactor tests are the main approaches for evaluation of safety performance of vehicle front design for pedestrian protection in legislative regulations. However, the main aspects of vehicle safety for pedestrians are shape and stiffness, and though it is clear that subsystem impact tests encourage lower vehicle front stiffness, it is unclear whether they promote improved vehicle front shapes for pedestrian protection. The purpose of this paper is therefore to investigate the effects of European pedestrian safety regulations on passenger car front shape and pedestrian injury risk using recent German In-Depth Accident Study (GIDAS) pedestrian collision data and numerical simulations. Firstly, a sample of 579 pedestrian collision cases involving 190 different car models between 2000-2015 extracted from the GIDAS was used to compare front-end shapes of passenger cars manufactured before and after the legislative pedestrian safety regulations were introduced in Europe. The focus was on changes in passenger car front shape and differences in pedestrian AIS2+ (Abbreviated Injury Scale at least level 2) leg, pelvis/femur and head injury risk observed in collisions. Multi-body simulations were also used to assess changes in vehicle aggressivity due to the observed changes in vehicle shape. The results show that newer passenger cars tend to have a flatter and wider bumper, higher bonnet leading edge, shorter and steeper bonnet and a shallower windscreen. Both the collision data and the numerical simulations indicate that newer passenger car front bumper designs are significantly safer for pedestrians' legs. However, the results also show that the higher bonnet leading edge in newer passenger cars is poor for pedestrian pelvis/femur protection, even though newer cars show an obviously lower AIS2+ injury risk to younger pedestrians in collisions. Newer cars have a lower AIS2+ head injury risk for pedestrians in collisions, but the numerical analysis indicate that this is not likely due to shape changes in passenger car fronts. Overall, the introduction of pedestrian safety regulations has resulted in reductions in pedestrian injury risk, but further benefits would accrue from tests which promote a lower bonnet leading edge. The influence of vehicle shape on pedestrian head injury risk remains unclear. Copyright © 2018 Elsevier Ltd. All rights reserved.

Two-Dimensional Edge Detection by Guided Mode Resonant Metasurface

NASA Astrophysics Data System (ADS)

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.

Shifts on reproductive phenology of tropical cerrado savanna trees and climate changes

NASA Astrophysics Data System (ADS)

Morellato, Patricia

2010-05-01

Phenology is the study of cyclic biological events and its relationship to abiotic factors. Timing of flowering, fruiting and leafing is highly correlated to environmental factors such as temperature, precipitation, irradiance and isolation. Accordingly, any change in these factors may have a direct effect on the initiation, intensity and duration of different phenophases. Tropical phenology has not contributed much for climatic change research since historical data sets are scarce and the absence of sharp seasons and distinct factors driving phenology makes difficult the detection of changes over time. One way to have insights on climate driven phenology shifts on tropical plants is through the comparison of plant phenology under different environmental conditions. Fragmentation of natural landscape has exposed plants to edge effects - the interaction between two adjacent ecosystems, when the two are separated by an abrupt transition - the edge, including both abiotic and biological changes on environmental conditions that likely affect plant phenology. The microclimatic conditions along edges have important direct biological effects on the reproductive phenology and fitness of plant species. One can expected that the abiotic edge effects on plant phenology may be similar to some extent to certain effects induced by climate change on plant phenology since both involve shifts on environmental conditions. Due to the threatened status and rich biodiversity of Brazilian Neotropical savanna, or the Brazilian Cerrado, the present study aimed to understand edge effects on cerrado savanna species. We compared micro environmental factors and phenology of several species on the edge and in the interior of cerrado savanna. Our first results indicated that shifts on the micro environmental condition may have driven changes in time, duration and intensity of species phenology and may give us insights on savanna responses to climate changes.

29 CFR 1918.32 - Stowed cargo and temporary landing surfaces.

Code of Federal Regulations, 2014 CFR

2014-07-01

... a hatch section or of stowed cargo may constitute a fall hazard to an employee, the edge shall be... intended. (c) When two gangs are working in the same hatch on different levels, a vertical safety net shall...

29 CFR 1918.32 - Stowed cargo and temporary landing surfaces.

Code of Federal Regulations, 2011 CFR

2011-07-01

... a hatch section or of stowed cargo may constitute a fall hazard to an employee, the edge shall be... intended. (c) When two gangs are working in the same hatch on different levels, a vertical safety net shall...

29 CFR 1918.32 - Stowed cargo and temporary landing surfaces.

Code of Federal Regulations, 2012 CFR

2012-07-01

... a hatch section or of stowed cargo may constitute a fall hazard to an employee, the edge shall be... intended. (c) When two gangs are working in the same hatch on different levels, a vertical safety net shall...

29 CFR 1918.32 - Stowed cargo and temporary landing surfaces.

Code of Federal Regulations, 2013 CFR

2013-07-01

... a hatch section or of stowed cargo may constitute a fall hazard to an employee, the edge shall be... intended. (c) When two gangs are working in the same hatch on different levels, a vertical safety net shall...

29 CFR 1918.32 - Stowed cargo and temporary landing surfaces.

Code of Federal Regulations, 2010 CFR

2010-07-01

... a hatch section or of stowed cargo may constitute a fall hazard to an employee, the edge shall be... intended. (c) When two gangs are working in the same hatch on different levels, a vertical safety net shall...

Charge collection and field profile studies of heavily irradiated strip sensors for the ATLAS inner tracker upgrade

NASA Astrophysics Data System (ADS)

Hara, K.; Allport, P. P.; Baca, M.; Broughton, J.; Chisholm, A.; Nikolopoulos, K.; Pyatt, S.; Thomas, J. P.; Wilson, J. A.; Kierstead, J.; Kuczewski, P.; Lynn, D.; Arratia, M.; Hommels, L. B. A.; Ullan, M.; Bloch, I.; Gregor, I. M.; Tackmann, K.; Trofimov, A.; Yildirim, E.; Hauser, M.; Jakobs, K.; Kuehn, S.; Mahboubi, K.; Mori, R.; Parzefall, U.; Clark, A.; Ferrere, D.; Gonzalez Sevilla, S.; Ashby, J.; Blue, A.; Bates, R.; Buttar, C.; Doherty, F.; McMullen, T.; McEwan, F.; O'Shea, V.; Kamada, S.; Yamamura, K.; Ikegami, Y.; Nakamura, K.; Takubo, Y.; Unno, Y.; Takashima, R.; Chilingarov, A.; Fox, H.; Affolder, A. A.; Casse, G.; Dervan, P.; Forshaw, D.; Greenall, A.; Wonsak, S.; Wormald, M.; Cindro, V.; Kramberger, G.; Mandić, I.; Mikuž, M.; Gorelov, I.; Hoeferkamp, M.; Palni, P.; Seidel, S.; Taylor, A.; Toms, K.; Wang, R.; Hessey, N. P.; Valencic, N.; Hanagaki, K.; Dolezal, Z.; Kodys, P.; Bohm, J.; Mikestikova, M.; Bevan, A.; Beck, G.; Milke, C.; Domingo, M.; Fadeyev, V.; Galloway, Z.; Hibbard-Lubow, D.; Liang, Z.; Sadrozinski, H. F.-W.; Seiden, A.; To, K.; French, R.; Hodgson, P.; Marin-Reyes, H.; Parker, K.; Jinnouchi, O.; Hara, K.; Sato, K.; Sato, K.; Hagihara, M.; Iwabuchi, S.; Bernabeu, J.; Civera, J. V.; Garcia, C.; Lacasta, C.; Marti i. Garcia, S.; Rodriguez, D.; Santoyo, D.; Solaz, C.; Soldevila, U.

2016-09-01

The ATLAS group has evaluated the charge collection in silicon microstrip sensors irradiated up to a fluence of 1 ×1016 neq/cm2, exceeding the maximum of 1.6 ×1015 neq/cm2 expected for the strip tracker during the high luminosity LHC (HL-LHC) period including a safety factor of 2. The ATLAS12, n+-on-p type sensor, which is fabricated by Hamamatsu Photonics (HPK) on float zone (FZ) substrates, is the latest barrel sensor prototype. The charge collection from the irradiated 1×1 cm2 barrel test sensors has been evaluated systematically using penetrating β-rays and an Alibava readout system. The data obtained at different measurement sites are compared with each other and with the results obtained from the previous ATLAS07 design. The results are very consistent, in particular, when the deposit charge is normalized by the sensor's active thickness derived from the edge transient current technique (edge-TCT) measurements. The measurements obtained using β-rays are verified to be consistent with the measurements using an electron beam. The edge-TCT is also effective for evaluating the field profiles across the depth. The differences between the irradiated ATLAS07 and ATLAS12 samples have been examined along with the differences among the samples irradiated with different radiation sources: neutrons, protons, and pions. The studies of the bulk properties of the devices show that the devices can yield a sufficiently large signal for the expected fluence range in the HL-LHC, thereby acting as precision tracking sensors.

Progress of recent experimental research on the J-TEXT tokamak

NASA Astrophysics Data System (ADS)

Zhuang, G.; Gentle, K. W.; Chen, Z. Y.; Chen, Z. P.; Yang, Z. J.; Zheng, Wei; Hu, Q. M.; Chen, J.; Rao, B.; Zhong, W. L.; Zhao, K. J.; Gao, L.; Cheng, Z. F.; Zhang, X. Q.; Wang, L.; Jiang, Z. H.; Xu, T.; Zhang, M.; Wang, Z. J.; Ding, Y. H.; Yu, K. X.; Hu, X. W.; Pan, Y.; Huang, H.; the J-TEXT Team

2017-10-01

The progress of experimental research over the last two years on the J-TEXT tokamak is reviewed and reported in this paper, including: investigations of resonant magnetic perturbations (RMPs) on the J-TEXT operation region show that moderate amplitude of applied RMPs either increases the density limit from less than 0.7n G to 0.85n G (n G is the Greenwald density, {{n}\\text{G}}={{I}\\text{p}}/π {{a}2} ) or lowers edge safety factor q a from 2.15 to nearly 2.0; observations of influence of RMPs with a large m/n  =  3/1 dominant component (where m and n are the toroidal and poloidal mode numbers respectively) on electron density indicate electron density first increases (decreases) inside (around/outside) of the 3/1 rational surface, and it is increased globally later together with enhanced edge recycling; investigations of the effect of RMPs on the behavior of runaway electrons/current show that application of RMPs with m/n  =  2/1 dominant component during disruptions can reduce runaway production. Furthermore, its application before the disruption can reduce both the amplitude and the length of runaway current; experimental results in the high-density disruption plasmas confirm that local current shrinkage during a multifaceted asymmetric radiation from the edge can directly terminate the discharge; measurements by a multi-channel Doppler reflectometer show that the quasi-coherent modes in the electron diamagnetic direction occur in the J-TEXT ohmic confinement regime in a large plasma region (r/a ~ 0.3-0.8) with frequency of 30-140 kHz.

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

NASA Technical Reports Server (NTRS)

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.

On the Existence of Simultaneous Edge Disjoint Realizations of Degree Sequences with ’Few’ Edges

DTIC Science & Technology

1975-08-01

constructing graphs and digraphs with given valences and factors. Discrete Math . 6 (1973) 79-88. 3. M. Keren, Realization of a sun of sequences by a sum...appear. 5. S. Kundu, The k factor conjecture is true. Discrete Math . 6 (1973) 367-376. 6. S. Kundu, Disjoint representation of tree realizable

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

PubMed Central

Brooks, Joseph L.; Driver, Jon

2010-01-01

Figure-ground organization involves 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. Here we show that assignment for a locally-unbiased edge can be affected by 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 propagation of figural edge-assignment, emerges from both subjective reports and from 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 upon edge-assignment. They also identify a new mechanistic relation between grouping and figure-ground processes, whereby grouping between remote elements can constrain propagation of edge-assignment between those elements. PMID:20436200

Characteristics of Low-q(a) Disruptions in the Compact Toroidal Hybrid

NASA Astrophysics Data System (ADS)

Pandya, M. D.; Archmiller, M. C.; Ennis, D. A.; Hartwell, G. J.; Maurer, D. A.

2014-10-01

Tokamak disruptions are dramatic events that lead to a sudden loss of plasma confinement. Disruptions that occur at low edge safety-factor, q (a) , limit the operation of tokamaks to q (a) >= 2 . The Compact Toroidal Hybrid (CTH) is a torsatron-tokamak hybrid with a helical field coil and vertical field coils to establish a stellartor equilibrium, while an ohmic coil induces plasma current. A feature of the CTH device is the ability to adjust the vacuum rotational transform, tvac (t =1/q ), by varying the ratio of current in the helical and toroidal field coils. The value of edge tvac can be varied from about 0.02 to 0.3 (qvac (a) ~ 50 to 3.3). Plasma discharges in CTH are routinely observed to operate with q (a) < 2 , and in some cases as low as q (a) ~ 1 . 1 . In CTH, low-q(a) disruptions are observed with a dominant m/n=3/2 precursor. The disruptivity of plasma discharges is over 80% when tvac (a) < 0 . 04 (qvac (a) < 25) and as tvac (a) is increased further, the disruptivity of the plasma discharges decreases. The disruptions are completely suppressed for tvac (a) > 0 . 07 (qvac (a) ~ 14) . This work is supported by US Department of Energy Grant No. DE-FG02-00ER54610.

Simulations of Low-q Disruptions in the Compact Toroidal Hybrid Experiment

NASA Astrophysics Data System (ADS)

Howell, E. C.; Hanson, J. D.; Ennis, D. A.; Hartwell, G. J.; Maurer, D. A.

2017-10-01

Resistive MHD simulations of low-q disruptions in the Compact Toroidal Hybrid Device (CTH) are performed using the NIMROD code. CTH is a current-carrying stellarator used to study the effects of 3D shaping on MHD stability. Experimentally, it is observed that the application of 3D vacuum fields allows CTH to operate with edge safety factor less than 2.0. However, these low-q discharges often disrupt after peak current if the applied 3D fields are too weak. Nonlinear simulations are initialized using model VMEC equilibria representative of low-q discharges with weak vacuum transform. Initially a series of symmetry preserving island chains are excited at the q=6/5, 7/5, 8/5, and 9/5 rational surfaces. These island chains act as transport barriers preventing stochastic magnetic fields in the edge from penetrating into the core. As the simulation progresses, predominately m/n=3/2 and 4/3 instabilities are destabilized. As these instabilities grow to large amplitude they destroy the symmetry preserving islands leading to large regions of stochastic fields. A current spike and loss of core thermal confinement occurs when the innermost island chain (6/5) is destroyed. Work Supported by US-DOE Grant #DE-FG02-03ER54692.

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

PubMed Central

Kelch, Nina-S.; Neves, Frederico S.; Fernandes, G. Wilson

2016-01-01

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. PMID:27310599

Estimated benefits of connected vehicle applications : dynamic mobility applications, AERIS, V2I safety, and road weather management applications.

DOT National Transportation Integrated Search

2015-08-01

Connected vehicles have the potential to transform travel as we know it by combining leading edge technologies advanced wireless communications, on-board computer processing, advanced vehicle-sensors, Global Positioning System (GPS) navigation, sm...

Observations of sea ice and icebergs in the western Barents Sea during the winter of 1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loeset, S.; Carstens, T.

1995-12-31

A multisensor ice data acquisition program for the western Barents Sea was carried out during three field campaigns in the mid winter and fall of 1987. The main purpose of the program was to obtain comprehensive information about the ice in the area at that time. The reasoning was that prior to any oil/gas exploration and production in the Barents Sea, the physical environment has to be quantitatively surveyed in order to ensure safe operations related to human safety, the regular operability and safety of the structure and protection of the environment. Prior to this field investigation program in 1987more » data on sea ice and icebergs for engineering purposes for the western Barents Sea were meager. The present paper highlights some of the findings with emphasis on ice edge speeds, ice edge displacement and ice drift. For icebergs, the paper focuses on population, size distributions and geometric parameters.« less

Plume interference with space shuttle range safety signals

NASA Technical Reports Server (NTRS)

Boynton, F. P.; Rajaseknar, P. S.

1979-01-01

The computational procedure for signal propagation in the presence of an exhaust plume is presented. Comparisons with well-known analytic diffraction solutions indicate that accuracy suffers when mesh spacing is inadequate to resolve the first unobstructed Fresnel zone at the plume edge. Revisions to the procedure to improve its accuracy without requiring very large arrays are discussed. Comparisons to field measurements during a shuttle solid rocket motor (SRM) test firing suggest that the plume is sharper edged than one would expect on the basis of time averaged electron density calculations. The effects, both of revisions to the computational procedure and of allowing for a sharper plume edge, are to raise the signal level near tail aspect. The attenuation levels then predicted are still high enough to be of concern near SRM burnout for northerly launches of the space shuttle.

Effects of Testing Method on Stretch-Flangeability of Dual-Phase 980/1180 Steel Grades

NASA Astrophysics Data System (ADS)

Madrid, Mykal; Van Tyne, Chester J.; Sadagopan, Sriram; Pavlina, Erik J.; Hu, Jun; Clarke, Kester D.

2018-04-01

Challenging fuel economy and safety standards in the automotive industry have led to the need for materials with higher strength while maintaining levels of formability that meet component manufacturing requirements. Advanced high-strength steels, such as dual-phase steels with tensile strengths of 980 MPa and 1180 MPa, are of interest to address this need. Increasing the strength of these materials typically comes at the expense of ductility, which may result in problems when stamping parts with trimmed or sheared edges, as cracking at the sheared edge may occur at lower strains. Here, hole expansion tests were performed with different punch geometries (conical and flat-bottom) and different edge conditions (sheared and machined) to understand the effects of testing conditions on performance, and these results are discussed in terms of mechanical properties and microstructures.

Effects of Testing Method on Stretch-Flangeability of Dual-Phase 980/1180 Steel Grades

NASA Astrophysics Data System (ADS)

Madrid, Mykal; Van Tyne, Chester J.; Sadagopan, Sriram; Pavlina, Erik J.; Hu, Jun; Clarke, Kester D.

2018-06-01

Challenging fuel economy and safety standards in the automotive industry have led to the need for materials with higher strength while maintaining levels of formability that meet component manufacturing requirements. Advanced high-strength steels, such as dual-phase steels with tensile strengths of 980 MPa and 1180 MPa, are of interest to address this need. Increasing the strength of these materials typically comes at the expense of ductility, which may result in problems when stamping parts with trimmed or sheared edges, as cracking at the sheared edge may occur at lower strains. Here, hole expansion tests were performed with different punch geometries (conical and flat-bottom) and different edge conditions (sheared and machined) to understand the effects of testing conditions on performance, and these results are discussed in terms of mechanical properties and microstructures.

Operating Characteristics in DIII-D ELM-Suppressed RMP H-modes with ITER Similar Shapes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, T E; Fenstermacher, M E; Jakubowski, M

2008-10-13

Fast energy transients, incident on the DIII-D divertors due to Type-I edge localized modes (ELMs), are eliminated using small dc currents in a simple set of non-axisymmetric coils that produce edge resonant magnetic perturbations (RMP). In ITER similar shaped (ISS) plasmas, with electron pedestal collisionalities matched to those expected in ITER a sharp resonant window in the safety factor at the 95 percent normalized poloidal flux surface is observed for ELM suppression at q{sub 95}=3.57 with a minimum width {delta}q{sub 95} of {+-}0.05. The size of this resonant window has been increased by a factor of 4 in ISS plasmasmore » by increasing the magnitude of the current in an n=3 coil set along with the current in a separate n=1 coil set. The resonant ELM-suppression window is highly reproducible for a given plasma shape, coil configuration and coil current but can vary with other operating conditions such as {beta}{sub N}. Isolated resonant windows have also been found at other q95 values when using different RMP coil configurations. For example, when the I-coil is operated in an n=3 up-down asymmetric configuration rather than an up-down symmetric configuration a resonant window is found near q{sub 95}=7.4. A Fourier analysis of the applied vacuum magnetic field demonstrates a statistical correlation between the Chirikov island overlap parameter and ELM suppression. These results have been used as a guide for RMP coil design studies in various ITER operating scenarios.« less

Non-axisymmetric equilibrium reconstruction of a current-carrying stellarator using external magnetic and soft x-ray inversion radius measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ma, X., E-mail: xzm0005@auburn.edu; Maurer, D. A.; Knowlton, S. F.

2015-12-15

Non-axisymmetric free-boundary equilibrium reconstructions of stellarator plasmas are performed for discharges in which the magnetic configuration is strongly modified by ohmically driven plasma current. These studies were performed on the compact toroidal hybrid device using the V3FIT reconstruction code with a set of 50 magnetic diagnostics external to the plasma. With the assumption of closed magnetic flux surfaces, the reconstructions using external magnetic measurements allow accurate estimates of the net toroidal flux within the last closed flux surface, the edge safety factor, and the plasma shape of these highly non-axisymmetric plasmas. The inversion radius of standard sawteeth is used tomore » infer the current profile near the magnetic axis; with external magnetic diagnostics alone, the current density profile is imprecisely reconstructed.« less

Non-axisymmetric equilibrium reconstruction of a current-carrying stellarator using external magnetic and soft x-ray inversion radius measurements

NASA Astrophysics Data System (ADS)

Ma, X.; Maurer, D. A.; Knowlton, S. F.; ArchMiller, M. C.; Cianciosa, M. R.; Ennis, D. A.; Hanson, J. D.; Hartwell, G. J.; Hebert, J. D.; Herfindal, J. L.; Pandya, M. D.; Roberds, N. A.; Traverso, P. J.

2015-12-01

Non-axisymmetric free-boundary equilibrium reconstructions of stellarator plasmas are performed for discharges in which the magnetic configuration is strongly modified by ohmically driven plasma current. These studies were performed on the compact toroidal hybrid device using the V3FIT reconstruction code with a set of 50 magnetic diagnostics external to the plasma. With the assumption of closed magnetic flux surfaces, the reconstructions using external magnetic measurements allow accurate estimates of the net toroidal flux within the last closed flux surface, the edge safety factor, and the plasma shape of these highly non-axisymmetric plasmas. The inversion radius of standard sawteeth is used to infer the current profile near the magnetic axis; with external magnetic diagnostics alone, the current density profile is imprecisely reconstructed.

Non-axisymmetric equilibrium reconstruction of a current-carrying stellarator using external magnetic and soft x-ray inversion radius measurements

DOE PAGES

Ma, X.; Maurer, D. A.; Knowlton, Stephen F.; ...

2015-12-22

Non-axisymmetric free-boundary equilibrium reconstructions of stellarator plasmas are performed for discharges in which the magnetic configuration is strongly modified by ohmically driven plasma current. These studies were performed on the compact toroidal hybrid device using the V3FIT reconstruction code with a set of 50 magnetic diagnostics external to the plasma. With the assumption of closed magnetic flux surfaces, the reconstructions using external magnetic measurements allow accurate estimates of the net toroidal flux within the last closed flux surface, the edge safety factor, and the plasma shape of these highly non-axisymmetric plasmas. Lastly, the inversion radius of standard saw-teeth is usedmore » to infer the current profile near the magnetic axis; with external magnetic diagnostics alone, the current density profile is imprecisely reconstructed.« less

Two-dimensional model of the interaction of a plane acoustic wave with nozzle edge and wing trailing edge.

PubMed

Faranosov, Georgy A; Bychkov, Oleg P

2017-01-01

The interaction of a plane acoustic wave with two-dimensional model of nozzle edge and trailing edge is investigated theoretically by means of the Wiener-Hopf technique. The nozzle edge and the trailing edge are simulated by two half-planes with offset edges. Shear layer behind the nozzle edge is represented by a vortex sheet supporting Kelvin-Helmholtz instability waves. The considered configuration combines two well-known models (nozzle edge and trailing edge), and reveals additional interesting physical aspects. To obtain the solution, the matrix Wiener-Hopf equation is solved in conjunction with a requirement that the full Kutta condition is imposed at the edges. Factorization of the kernel matrix is performed by the combination of Padé approximation and the pole removal technique. This procedure is used to obtain numerical results. The results indicate that the diffracted acoustic field may be significantly intensified due to scattering of hydrodynamic instability waves into sound waves provided that the trailing edge is close enough to the vortex sheet. Similar mechanism may be responsible for the intensification of jet noise near a wing.

Edge waves and resonances in two-dimensional phononic crystal plates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsu, Jin-Chen, E-mail: hsujc@yuntech.edu.tw; Hsu, Chih-Hsun

2015-05-07

We present a numerical study on phononic band gaps and resonances occurring at the edge of a semi-infinite two-dimensional (2D) phononic crystal plate. The edge supports localized edge waves coupling to evanescent phononic plate modes that decay exponentially into the semi-infinite phononic crystal plate. The band-gap range and the number of edge-wave eigenmodes can be tailored by tuning the distance between the edge and the semi-infinite 2D phononic lattice. As a result, a phononic band gap for simultaneous edge waves and plate waves is created, and phononic cavities beside the edge can be built to support high-frequency edge resonances. Wemore » design an L3 edge cavity and analyze its resonance characteristics. Based on the band gap, high quality factor and strong confinement of resonant edge modes are achieved. The results enable enhanced control over acoustic energy flow in phononic crystal plates, which can be used in designing micro and nanoscale resonant devices and coupling of edge resonances to other types of phononic or photonic crystal cavities.« less

A Thermostructural Analysis of a Diboride Composite Leading Edge

NASA Technical Reports Server (NTRS)

Kowalski, Tom; Buesking, Kent; Kolodziej, Paul; Bull, Jeff

1996-01-01

In an effort to support the design of zirconium diboride composite leading edges for hypersonic vehicles, a finite element model (FEM) of a prototype leading edge was created and finite element analysis (FEA) was employed to assess its thermal and structural response to aerothermal boundary conditions. Unidirectional material properties for the structural components of the leading edge, a continuous fiber reinforced diboride composite, were computed with COSTAR. These properties agree well with those experimentally measured. To verify the analytical approach taken with COSMOS/M, an independent FEA of one of the leading edge assembly components was also done with COSTAR. Good agreement was obtained between the two codes. Both showed that a unidirectional lay-up had the best margin of safety for a simple loading case. Both located the maximum stress in the same region and ply. The magnitudes agreed within 4 percent. Trajectory based aerothermal heating was then applied to the leading edge assembly FEM created with COSMOS/M to determine steady state temperature response, displacement, stresses, and contact forces due to thermal expansion and thermal strains. Results show that the leading edge stagnation line temperature reached 4700 F. The maximum computed failure index for the laminated composite components peaks at 4.2, and is located at the bolt flange in layer 2 of the side bracket. The temperature gradient in the tip causes a compressive stress of 279 ksi along its width and substantial tensile stresses within its depth.

16 CFR 1511.5 - Structural integrity tests.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Structural integrity tests. 1511.5 Section 1511.5 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION FEDERAL HAZARDOUS SUBSTANCES ACT... lowest position in the cylinder. If the uppermost edge of the component or fragment is below the plane of...

Pancreatic head cryosurgery: safety and efficiency in vivo--a pilot study.

PubMed

Li, Jialiang; Zhou, Liang; Chen, Jibing; Wu, Binghui; Zeng, Jianying; Fang, Gang; Deng, Chunjuan; Huang, Shengquan; Yao, Fei; Chen, Zhixian; Leng, Yin; Deng, Min; Deng, Chunmei; Zhang, Bo; Zhou, Gang; He, Lihua; Liao, Maoxin; Chiu, David; Niu, Lizhi; Zuo, Jiansheng; Xu, Kecheng

2012-11-01

Pancreatic cancer is the fourth leading cause of cancer-related death. Cryosurgery has emerged as a promising new technique for treatment. Although 80% of pancreatic cancers are located in the pancreatic head, no research has been conducted on the safety and efficacy of cryosurgery for these tumors. Two groups of Tibetan miniature pigs (n = 4 per group) underwent cryosurgery to the pancreatic head with either the deep freezing protocol (100% argon output) or shallow freezing protocol (10% argon output), and compared to sham-operated pigs. Serum inflammatory factors and amylase increased during the 5 days after cryoablation in both groups but acute pancreatitis did not occur. Adhesions were observed between the pancreatic head and adjacent organs, and only minor trauma was caused to the stomach, duodenum, small intestine, and liver. Ice balls with a radius of 0.5 cm beyond the tumor edge were sufficient to cause complete necrosis of the pancreatic tissue, and decreased the degree of cold injury to surrounding tissues. Shallow freezing protocol seemed to be safer than, and just as effective as, the deep freezing protocol. This preliminary study suggests that cryosurgery could potentially be an effective treatment of cancer of the pancreatic head.

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

PubMed

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.

An Iris Segmentation Algorithm based on Edge Orientation for Off-angle Iris Recognition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karakaya, Mahmut; Barstow, Del R; Santos-Villalobos, Hector J

Iris recognition is known as one of the most accurate and reliable biometrics. However, the accuracy of iris recognition systems depends on the quality of data capture and is negatively affected by several factors such as angle, occlusion, and dilation. In this paper, we present a segmentation algorithm for off-angle iris images that uses edge detection, edge elimination, edge classification, and ellipse fitting techniques. In our approach, we first detect all candidate edges in the iris image by using the canny edge detector; this collection contains edges from the iris and pupil boundaries as well as eyelash, eyelids, iris texturemore » etc. Edge orientation is used to eliminate the edges that cannot be part of the iris or pupil. Then, we classify the remaining edge points into two sets as pupil edges and iris edges. Finally, we randomly generate subsets of iris and pupil edge points, fit ellipses for each subset, select ellipses with similar parameters, and average to form the resultant ellipses. Based on the results from real experiments, the proposed method shows effectiveness in segmentation for off-angle iris images.« less

Stress intensity factor in a tapered specimen

NASA Technical Reports Server (NTRS)

Xue-Hui, L.; Erdogan, F.

1985-01-01

The general problem of a tapered specimen containing an edge crack is formulated in terms of a system of singular integral equations. The equations are solved and the stress intensity factor is calculated for a compact and for a slender tapered specimen, the latter simulating the double cantilever beam. The results are obtained primarily for a pair of concentrated forces and for crack surface wedge forces. The stress intensity factors are also obtained for a long strip under uniform tension which contains inclined edge cracks.

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

PubMed

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.

Which type of placenta previa requires blood transfusion more frequently? A new concept of indiscernible edge total previa.

PubMed

Baba, Yosuke; Takahashi, Hironori; Ohkuchi, Akihide; Usui, Rie; Matsubara, Shigeki

2016-11-01

During cesarean section (CS) for placenta previa (PP), the size/area/portion of the lower uterine segment occupied by the placenta may affect the bleeding amount and the subsequent need for a blood transfusion (BT). We propose a new concept, indiscernible edge total PP (IEPP), when vaginal ultrasound does not discern the lower placental edge because the placenta covers the visible lower segment. We characterized IEPP, focusing on its allogeneic BT requirement. We classified PP (n = 307) into four types: marginal, partial, discernible edge total PP (DEPP) and IEPP: internal ostium (os)-placental edge distance measurable or unmeasurable on vaginal ultrasound in DEPP or IEPP, respectively. We determined the clinical characteristics according to the four types; the relationship between the intraoperative blood loss and os-edge distance in DEPP; and risk factors for allogeneic BT. The following were significantly higher/larger in cases of IEPP: previous CS; anterior placentation; lacunae; elective cesarean hysterectomy; intraoperative blood loss; autologous BT; allogeneic BT; intensive care unit admission; and an abnormally invasive placenta (AIP). In DEPP, the os-edge distance was weakly correlated with the bleeding amount (r = 0.214). Multivariate logistic regression analysis showed that previous CS, lacunae, AIP and IEPP were independent risk factors for allogeneic BT (odds ratios 3.8, 3.1, 13.8 and 4.6, respectively). After excluding patients undergoing hemostatic procedures during CS, IEPP remained the only independent risk factor for allogeneic BT (odds ratio 5.2). The new concept of IEPP may be useful for predicting BT in CS for patients with PP. © 2016 Japan Society of Obstetrics and Gynecology.

NASA and general aviation

NASA Technical Reports Server (NTRS)

Ethell, J. L.

1986-01-01

General aviation remains the single most misunderstood sector of aeronautics in the United States. A detailed look at how general aviation functions and how NASA helps keep it on the cutting edge of technology in airfoils, airframes, commuter travel, environmental concerns, engines, propellers, air traffic control, agricultural development, electronics, and safety is given.

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

PubMed Central

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

2016-01-01

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. PMID:27834823

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

PubMed

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.

A hierarchical factor analysis of a safety culture survey.

PubMed

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.

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

DOE PAGES

Hanson, Jeremy M.; Bialek, James M.; Baruzzo, M.; ...

2014-07-07

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 themore » 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. As a result, the experiments contribute to validating MHD stability theory and demonstrate that a key tokamak stability limit can be overcome with feedback.« less

KSC-04pd2127

NASA Image and Video Library

2004-10-12

KENNEDY SPACE CENTER, FLA. - This photo shows the size of the sensors being placed on the wing leading edge of orbiter Discovery. In her hand, United Space Alliance technician Lisa Campbell holds an accelerometer (left), which will eventually be installed on a mounting nut. The sensors are part of the Wing Leading Edge Impact Detection System, a new safety measure added for all future Space Shuttle missions. The system also includes accelerometers that monitor the orbiter's wings for debris impacts during launch and while in orbit. There are 22 temperature sensors and 66 accelerometers on each wing. Sensor data will flow from the wing to the crew compartment, where it will be transmitted to Earth.

KSC-04PD-2127

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. This photo shows the size of the sensors being placed on the wing leading edge of orbiter Discovery. In her hand, United Space Alliance technician Lisa Campbell holds an accelerometer (left), which will eventually be installed on a mounting nut. The sensors are part of the Wing Leading Edge Impact Detection System, a new safety measure added for all future Space Shuttle missions. The system also includes accelerometers that monitor the orbiter's wings for debris impacts during launch and while in orbit. There are 22 temperature sensors and 66 accelerometers on each wing. Sensor data will flow from the wing to the crew compartment, where it will be transmitted to Earth.

Parameter dependence of ELM loss reduction by magnetic perturbations at low pedestal density and collisionality in ASDEX upgrade

NASA Astrophysics Data System (ADS)

Leuthold, N.; Suttrop, W.; Fischer, R.; Kappatou, A.; Kirk, A.; McDermott, R.; Mlynek, A.; Valovič, M.; Willensdorfer, M.; the ASDEX Upgrade Team; the EUROfusion MST1 Team

2017-05-01

ELM mitigation by magnetic perturbations is studied at low pedestal collisionalities down to ITER-like values ({ν }{e,{PED}}* =0.1) in ASDEX Upgrade. A comprehensive database of ELM energy losses for varying plasma density, heating power, edge safety factor and magnetic perturbation structure has been assembled to investigate parameter dependencies of ELM mitigation. It is found that magnetic perturbations with a toroidal mode number n = 2 can reduce the ELM energy loss normalized to the energy stored in the plasma pedestal from about 30% to less than 5%, i.e. by a factor of six, below an electron pedestal collisionality of {ν }{e,{PED}}* =0.4. At this level of ELM mitigation a significant reduction of the pedestal pressure and, therefore, global plasma confinement occurs. This pedestal pressure reduction is mostly due to a reduction of plasma density, the so-called ‘pump-out’ effect. Refueling by neutral beams and in particular by pellet injection is possible and can re-establish confinement, however, the ELM energy loss increases as well with increasing density.

Edge-Cracking Behavior of CoCrFeMnNi High-Entropy Alloy During Hot Rolling

NASA Astrophysics Data System (ADS)

Won, Jong Woo; Kang, Minju; Kwon, Heoun-Jun; Lim, Ka Ram; Seo, Seong Moon; Na, Young Sang

2018-05-01

This work investigated edge-cracking behavior of equiatomic CoCrFeMnNi high-entropy alloy during hot rolling at rolling temperatures 500 ≤ T R ≤ 1000 °C. Edge cracks did not form in the material rolled at 500 °C, but widened and deepened into the inside of plate as T R increased from 500 °C. Edge cracks were most severe in the material rolled at 1000 °C. Mn-Cr-O type non-metallic inclusion and oxidation were identified as major factors that caused edge cracking. The inclusions near edge region acted as preferential sites for crack formation. Connection between inclusion cracks and surface cracks induced edge cracking. Rolling at T R ≥ 600 °C generated distinct inclusion cracks whereas they were not serious at T R = 500 °C, so noticeable edge cracks formed at T R ≥ 600 °C. At T R = 1000 °C, significant oxidation occurred at the crack surface. This accelerated edge crack penetration by embrittling the crack tip, so severe edge cracking occurred at T R = 1000 °C.

Selective Equilibration of Spin-Polarized Quantum Hall Edge States in Graphene

NASA Astrophysics Data System (ADS)

Amet, F.; Williams, J. R.; Watanabe, K.; Taniguchi, T.; Goldhaber-Gordon, D.

2014-05-01

We report on transport measurements of dual-gated, single-layer graphene devices in the quantum Hall regime, allowing for independent control of the filling factors in adjoining regions. Progress in device quality allows us to study scattering between edge states when the fourfold degeneracy of the Landau level is lifted by electron correlations, causing edge states to be spin and/or valley polarized. In this new regime, we observe a dramatic departure from the equilibration seen in more disordered devices: edge states with opposite spins propagate without mixing. As a result, the degree of equilibration inferred from transport can reveal the spin polarization of the ground state at each filling factor. In particular, the first Landau level is shown to be spin polarized at half filling, providing an independent confirmation of a conclusion of Young et al. [Nat. Phys. 8, 550 (2012)]. The conductance in the bipolar regime is strongly suppressed, indicating that copropagating edge states, even with the same spin, do not equilibrate along PN interfaces. We attribute this behavior to the formation of an insulating ν =0 stripe at the PN interface.

Experimental studies of high-confinement mode plasma response to non-axisymmetric magnetic perturbations in ASDEX Upgrade

DOE PAGES

Suttrop, Wolfgang; Kirk, A.; Nazikian, R.; ...

2016-11-22

Here, the interaction of externally applied small non-axisymmetric magnetic perturbations (MP) with tokamak high-confinement mode (H-mode) plasmas is reviewed and illustrated by recent experiments in ASDEX Upgrade. The plasma response to the vacuum MP field is amplified by stable ideal kink modes with low toroidal mode number n driven by the H-mode edge pressure gradient (and associated bootstrap current) which is experimentally evidenced by an observable shift of the poloidal mode number m away from field alignment (m = qn, with q being the safety factor) at the response maximum. A torque scan experiment demonstrates the importance of the perpendicular electron flow for shielding of the resonant magnetic perturbation, as expected from a two-fluid MHD picture. Two significant effects of MP occur in H-mode plasmas at low pedestal collisionality,more » $$\

To Demonstrate an Integrated Solution for Plasma-Material Interfaces Compatible with an Optimized Core Plasma

NASA Astrophysics Data System (ADS)

Goldston, Robert; Brooks, Jeffrey; Hubbard, Amanda; Leonard, Anthony; Lipschultz, Bruce; Maingi, Rajesh; Ulrickson, Michael; Whyte, Dennis

2009-11-01

The plasma facing components in a Demo reactor will face much more extreme boundary plasma conditions and operating requirements than any present or planned experiment. These include 1) Power density a factor of four or more greater than in ITER, 2) Continuous operation resulting in annual energy and particle throughput 100-200 times larger than ITER, 3) Elevated surface operating temperature for efficient electricity production, 4) Tritium fuel cycle control for safety and breeding requirements, and 5) Steady state plasma confinement and control. Consistent with ReNeW Thrust 12, design options are being explored for a new moderate-scale facility to assess core-edge interaction issues and solutions. Key desired features include high power density, sufficient pulse length and duty cycle, elevated wall temperature, steady-state control of an optimized core plasma, and flexibility in changing boundary components as well as access for comprehensive measurements.

Stress-intensity factors for a thick-walled cylinder containing an annular imbedded or external or internal surface crack

NASA Technical Reports Server (NTRS)

Erdol, R.; Erdogan, F.

1976-01-01

The elastostatic axisymmetric problem for a long thick-walled cylinder containing a ring-shaped internal or edge crack is considered. Using the standard transform technique the problem is formulated in terms of an integral equation which has a simple Cauchy kernel for the internal crack and a generalized Cauchy kernel for the edge crack as the dominant part. As examples the uniform axial load and the steady-state thermal stress problems have been solved and the related stress intensity factors have been calculated. Among other findings the results show that in the cylinder under uniform axial stress containing an internal crack the stress intensity factor at the inner tip is always greater than that at the outer tip for equal net ligament thicknesses and in the cylinder with an edge crack which is under a state of thermal stress the stress intensity factor is a decreasing function of the crack depth, tending to zero as the crack depth approaches the wall thickness.

The watercolor effect: a new principle of grouping and figure-ground organization.

PubMed

Pinna, Baingio; Werner, John S; Spillmann, Lothar

2003-01-01

The watercolor effect is perceived when a dark (e.g., purple) contour is flanked by a lighter chromatic contour (e.g., orange). Under these conditions, the lighter color will assimilate over the entire enclosed area. This filling-in determines figure-ground organization when it is pitted against the classical Gestalt factors of proximity, good continuation, closure, symmetry, convexity, as well as amodal completion, and past experience. When it is combined with a given Gestalt factor, the resulting effect on figure-ground organization is stronger than for each factor alone. When the watercolor effect is induced by a dark red edge instead of an orange edge, its figural strength is reduced, but still stronger than without it. Finally, when a uniform surface is filled physically using the color of the orange fringe, figure-ground organization is not different from that for the purple contour only. These findings show that the watercolor effect induced by the edge could be an independent factor, different from the classical Gestalt factors of figure-ground organization. Copyright 2002 Elsevier Science Ltd.

NASA and General Aviation. NASA SP-485.

ERIC Educational Resources Information Center

Ethell, Jeffrey L.

A detailed examination of the nature and function of general aviation and a discussion of how the National Aeronautics and Space Administration (NASA) helps keep it on the cutting edge of technology are offered in this publication. The intricacies of aerodynamics, energy, and safety as well as the achievements in aeronautical experimentation are…

49 CFR 213.139 - Spring rail frogs.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of each...

49 CFR 213.139 - Spring rail frogs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of each...

49 CFR 213.139 - Spring rail frogs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of each...

49 CFR 213.139 - Spring rail frogs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of each...

49 CFR 213.139 - Spring rail frogs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Spring rail frogs. 213.139 Section 213.139..., DEPARTMENT OF TRANSPORTATION TRACK SAFETY STANDARDS Track Structure § 213.139 Spring rail frogs. (a) The outer edge of a wheel tread shall not contact the gage side of a spring wing rail. (b) The toe of each...

29 CFR 1910.145 - Specifications for accident prevention signs and tags.

Code of Federal Regulations, 2014 CFR

2014-07-01

... from sharp edges, burrs, splinters, or other sharp projections. The ends or heads of bolts or other... portion of a tag's inscription that is more specific than the signal word and that indicates the specific... convey a safety instruction. Signal word means that portion of a tag's inscription that contains the word...

75 FR 48370 - Biweekly Notice Applications and Amendments to Facility Operating Licenses Involving No...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-10

... revise the minimum Emergency Diesel Generator (EDG) output voltage acceptance criterion in Surveillance... ensures the timely transfer of plant safety system loads to the Emergency Diesel Generators in the event a... from the emergency diesel generators in a timely manner. This change is needed to bring Fermi 2 into...

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

NASA Astrophysics Data System (ADS)

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.

Decoherence of high-energy electrons in weakly disordered quantum Hall edge states

NASA Astrophysics Data System (ADS)

Nigg, Simon E.; Lunde, Anders Mathias

2016-07-01

We investigate theoretically the phase coherence of electron transport in edge states of the integer quantum Hall effect at filling factor ν =2 , in the presence of disorder and inter edge state Coulomb interaction. Within a Fokker-Planck approach, we calculate analytically the visibility of the Aharonov-Bohm oscillations of the current through an electronic Mach-Zehnder interferometer. In agreement with recent experiments, we find that the visibility is independent of the energy of the current-carrying electrons injected high above the Fermi sea. Instead, it is the amount of disorder at the edge that sets the phase space available for inter edge state energy exchange and thereby controls the visibility suppression.

Lemur responses to edge effects in the Vohibola III classified forest, Madagascar.

PubMed

Lehman, Shawn M; Rajaonson, Andry; Day, Sabine

2006-03-01

Forest edges are dynamic zones characterized by the penetration (to varying depths and intensities) of conditions from the surrounding environment (matrix) into the forest interior. Although edge effects influence many tropical organisms, they have not been studied directly in primates. Edge effects are particularly relevant to lemurs because of the highly fragmented forest landscapes found in Madagascar. In this study, data are presented regarding how the densities of six lemur species (Avahi laniger, Cheirogaleus major, Eulemur rubriventer, Hapalemur griseus griseus, Microcebus rufus, and Propithecus diadema edwardsi) varied between six 500-m interior transects and six 500-m edge transects in the Vohibola III Classified Forest in SE Madagascar. Diurnal (n = 433) and nocturnal (n = 128) lemur surveys were conducted during June-October 2003 and May-November 2004. A. laniger, E. rubriventer, and H. g. griseus exhibited a neutral edge response (no differences in densities between habitats). M. rufus and P. d. edwardsi had a positive edge response (higher densities in edge habitats), which may be related to edge-related variations in food abundance and quality. Positive edge responses by M. rufus and P. d. edwardsi may ultimately be detrimental due to edge-related anthropogenic factors (e.g., hunting by local people). The negative edge response exhibited by C. major (lower densities in edge habitats) may result from heightened ambient temperatures that inhibit torpor in edge habitats.

Silicon K-edge XANES spectra of silicate minerals

NASA Astrophysics Data System (ADS)

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.

Some factors influencing radiation of sound from flow interaction with edges of finite surfaces

NASA Technical Reports Server (NTRS)

Hayden, R. E.; Fox, H. L.; Chanaud, R. C.

1976-01-01

Edges of surfaces which are exposed to unsteady flow cause both strictly acoustic effects and hydrodynamic effects, in the form of generation of new hydrodynamic sources in the immediate vicinity of the edge. An analytical model is presented which develops the explicit sound-generation role of the velocity and Mach number of the eddy convection past the edge, and the importance of relative scale lengths of the turbulence, as well as the relative intensity of pressure fluctuations. The Mach number (velocity) effects show that the important paramater is the convection Mach number of the eddies. The effects of turbulence scale lengths, isotropy, and spatial density (separation) are shown to be important in determining the level and spectrum of edge sound radiated for the edge dipole mechanism. Experimental data is presented which provides support for the dipole edge noise model in terms of Mach number (velocity) scaling, parametric dependence on flow field parameter, directivity, and edge diffraction effects.

Temperature dependence of pre-edge features in Ti K-edge XANES spectra for ATiO₃ (A = Ca and Sr), A₂TiO₄ (A = Mg and Fe), TiO₂ rutile and TiO₂ anatase.

PubMed

Hiratoko, Tatsuya; Yoshiasa, Akira; Nakatani, Tomotaka; Okube, Maki; Nakatsuka, Akihiko; Sugiyama, Kazumasa

2013-07-01

XANES (X-ray absorption near-edge structure) spectra of the Ti K-edges of ATiO3 (A = Ca and Sr), A2TiO4 (A = Mg and Fe), TiO2 rutile and TiO2 anatase were measured in the temperature range 20-900 K. Ti atoms for all samples were located in TiO6 octahedral sites. The absorption intensity invariant point (AIIP) was found to be between the pre-edge and post-edge. After the AIIP, amplitudes damped due to Debye-Waller factor effects with temperature. Amplitudes in the pre-edge region increased with temperature normally by thermal vibration. Use of the AIIP peak intensity as a standard point enables a quantitative comparison of the intensity of the pre-edge peaks in various titanium compounds over a wide temperature range.

Wing high-lift system with spoiler droop

NASA Astrophysics Data System (ADS)

Gubsky, Vitaly; Pavlenko, Olga; Petrov, Albert

2018-05-01

Take-off and landing regimes are becoming increasingly difficult due to the increased aircraft mass and speed and the toughening of air safety demands. The capabilities of conventional single-slotted or multi-slotted flaps are limited. This problem can be resolved by the deflection or bending of the tail section, which forms a potential flow that results in an increase in the lift component at high angles of attack. Different versions of the flap on a two-part high-lift device with a spoiler are examined. Calculations show that the application of an adaptive high-lift system with spoiler droop to an aircraft increases the lift coefficient by as much as 15%. Aircraft model experiments indicated that a δs = 5° deflection of the trailing edge increases the lift coefficient by 11% - 13%. Setting the propeller load coefficient to B = 1 (thrust/velocity factor propeller area) under take-off δf = 20° and landing δf = 35° configurations increases the efficiency of a lift coefficient by 25% and 36%, respectively. The application of spoiler droop and leading edge modifications of the wing expands the operational range of angles of attack and increases the lift coefficient by 10% at a small intensity (B = 0.5). It is concluded that the application of spoiler droop to high-lift system allows improvement of the wing properties under take-off and landing regimes of various types.

Edge detection and localization with edge pattern analysis and inflection characterization

NASA Astrophysics Data System (ADS)

Jiang, Bo

2012-05-01

In general edges are considered to be abrupt changes or discontinuities in two dimensional image signal intensity distributions. The accuracy of front-end edge detection methods in image processing impacts the eventual success of higher level pattern analysis downstream. To generalize edge detectors designed from a simple ideal step function model to real distortions in natural images, research on one dimensional edge pattern analysis to improve the accuracy of edge detection and localization proposes an edge detection algorithm, which is composed by three basic edge patterns, such as ramp, impulse, and step. After mathematical analysis, general rules for edge representation based upon the classification of edge types into three categories-ramp, impulse, and step (RIS) are developed to reduce detection and localization errors, especially reducing "double edge" effect that is one important drawback to the derivative method. But, when applying one dimensional edge pattern in two dimensional image processing, a new issue is naturally raised that the edge detector should correct marking inflections or junctions of edges. Research on human visual perception of objects and information theory pointed out that a pattern lexicon of "inflection micro-patterns" has larger information than a straight line. Also, research on scene perception gave an idea that contours have larger information are more important factor to determine the success of scene categorization. Therefore, inflections or junctions are extremely useful features, whose accurate description and reconstruction are significant in solving correspondence problems in computer vision. Therefore, aside from adoption of edge pattern analysis, inflection or junction characterization is also utilized to extend traditional derivative edge detection algorithm. Experiments were conducted to test my propositions about edge detection and localization accuracy improvements. The results support the idea that these edge detection method improvements are effective in enhancing the accuracy of edge detection and localization.

Generalized M-factor of hollow Gaussian beams through a hard-edge circular aperture

NASA Astrophysics Data System (ADS)

Deng, Dongmei

2005-06-01

Based on the generalized truncated second-order moments, the generalized M-factor (MG2-factor) of three-dimensional hollow Gaussian beams (HGBs) through a hard-edge circular aperture is studied in cylindrical coordinate system analytically and numerically. The closed-form expression for the MG2-factor of the truncated HGBs, which is dependent on the truncation parameter β and the beam order n, can be simplified to that of the truncated, the untruncated Gaussian beams and the untruncated HGBs. Also, the power fraction is demonstrated analytically and numerically, which shows that the area of the dark region across the HGBs increases as n increasing.

Optimization of edge state velocity in the integer quantum Hall regime

NASA Astrophysics Data System (ADS)

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.

Zooming in and out: Scale dependence of extrinsic and intrinsic factors affecting salt marsh erosion

NASA Astrophysics Data System (ADS)

Wang, Heng; van der Wal, Daphne; Li, Xiangyu; van Belzen, Jim; Herman, Peter M. J.; Hu, Zhan; Ge, Zhenming; Zhang, Liquan; Bouma, Tjeerd J.

2017-07-01

Salt marshes are valuable ecosystems that provide important ecosystem services. Given the global scale of marsh loss due to climate change and coastal squeeze, there is a pressing need to identify the critical extrinsic (wind exposure and foreshore morphology) and intrinsic factors (soil and vegetation properties) affecting the erosion of salt marsh edges. In this study, we quantified rates of cliff lateral retreat (i.e., the eroding edge of a salt marsh plateau) using a time series of aerial photographs taken over four salt marsh sites in the Westerschelde estuary, the Netherlands. In addition, we experimentally quantified the erodibility of sediment cores collected from the marsh edge of these four marshes using wave tanks. Our results revealed the following: (i) at the large scale, wind exposure and the presence of pioneer vegetation in front of the cliff were the key factors governing cliff retreat rates; (ii) at the intermediate scale, foreshore morphology was partially related to cliff retreat; (iii) at the local scale, the erodibility of the sediment itself at the marsh edge played a large role in determining the cliff retreat rate; and (iv) at the mesocosm scale, cliff erodibility was determined by soil properties and belowground root biomass. Thus, both extrinsic and intrinsic factors determined the fate of the salt marsh but at different scales. Our study highlights the importance of understanding the scale dependence of the factors driving the evolution of salt marsh landscapes.

Edge Diffusion Flame Propagation and Stabilization Studied

NASA Technical Reports Server (NTRS)

Takahashi, Fumiaki; Katta, Viswanath R.

2004-01-01

In most practical combustion systems or fires, fuel and air are initially unmixed, thus forming diffusion flames. As a result of flame-surface interactions, the diffusion flame often forms an edge, which may attach to burner walls, spread over condensed fuel surfaces, jump to another location through the fuel-air mixture formed, or extinguish by destabilization (blowoff). Flame holding in combustors is necessary to achieve design performance and safe operation of the system. Fires aboard spacecraft behave differently from those on Earth because of the absence of buoyancy in microgravity. This ongoing in-house flame-stability research at the NASA Glenn Research Center is important in spacecraft fire safety and Earth-bound combustion systems.

Predict-first experimental analysis using automated and integrated magnetohydrodynamic modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lyons, B. C.; Paz-Soldan, C.; Meneghini, O.

An integrated-modeling workflow has been developed in this paper for the purpose of performing predict-first analysis of transient-stability experiments. Starting from an existing equilibrium reconstruction from a past experiment, the workflow couples together the EFIT Grad-Shafranov solver [L. Lao et al., Fusion Sci. Technol. 48, 968 (2005)], the EPED model for the pedestal structure [P. B. Snyder et al., Phys. Plasmas 16, 056118 (2009)], and the NEO drift-kinetic-equation solver [E. A. Belli and J. Candy, Plasma Phys. Controlled Fusion 54, 015015 (2012)] (for bootstrap current calculations) in order to generate equilibria with self-consistent pedestal structures as the plasma shape andmore » various scalar parameters (e.g., normalized β, pedestal density, and edge safety factor [q 95]) are changed. These equilibria are then analyzed using automated M3D-C1 extended-magnetohydrodynamic modeling [S. C. Jardin et al., Comput. Sci. Discovery 5, 014002 (2012)] to compute the plasma response to three-dimensional magnetic perturbations. This workflow was created in conjunction with a DIII-D experiment examining the effect of triangularity on the 3D plasma response. Several versions of the workflow were developed, and the initial ones were used to help guide experimental planning (e.g., determining the plasma current necessary to maintain the constant edge safety factor in various shapes). Subsequent validation with the experimental results was then used to revise the workflow, ultimately resulting in the complete model presented here. We show that quantitative agreement was achieved between the M3D-C1 plasma response calculated for equilibria generated by the final workflow and equilibria reconstructed from experimental data. A comparison of results from earlier workflows is used to show the importance of properly matching certain experimental parameters in the generated equilibria, including the normalized β, pedestal density, and q 95. On the other hand, the details of the pedestal current did not significantly impact the plasma response in these equilibria. A comparison to the experimentally measured plasma response shows mixed agreement, indicating that while the equilibria are predicted well, additional analysis tools may be needed. In conclusion, we note the implications that these results have for the success of future predict-first studies, particularly the need for scans of uncertain parameters and for close collaboration between experimentalists and theorists.« less

Predict-first experimental analysis using automated and integrated magnetohydrodynamic modeling

DOE PAGES

Lyons, B. C.; Paz-Soldan, C.; Meneghini, O.; ...

2018-05-07

An integrated-modeling workflow has been developed in this paper for the purpose of performing predict-first analysis of transient-stability experiments. Starting from an existing equilibrium reconstruction from a past experiment, the workflow couples together the EFIT Grad-Shafranov solver [L. Lao et al., Fusion Sci. Technol. 48, 968 (2005)], the EPED model for the pedestal structure [P. B. Snyder et al., Phys. Plasmas 16, 056118 (2009)], and the NEO drift-kinetic-equation solver [E. A. Belli and J. Candy, Plasma Phys. Controlled Fusion 54, 015015 (2012)] (for bootstrap current calculations) in order to generate equilibria with self-consistent pedestal structures as the plasma shape andmore » various scalar parameters (e.g., normalized β, pedestal density, and edge safety factor [q 95]) are changed. These equilibria are then analyzed using automated M3D-C1 extended-magnetohydrodynamic modeling [S. C. Jardin et al., Comput. Sci. Discovery 5, 014002 (2012)] to compute the plasma response to three-dimensional magnetic perturbations. This workflow was created in conjunction with a DIII-D experiment examining the effect of triangularity on the 3D plasma response. Several versions of the workflow were developed, and the initial ones were used to help guide experimental planning (e.g., determining the plasma current necessary to maintain the constant edge safety factor in various shapes). Subsequent validation with the experimental results was then used to revise the workflow, ultimately resulting in the complete model presented here. We show that quantitative agreement was achieved between the M3D-C1 plasma response calculated for equilibria generated by the final workflow and equilibria reconstructed from experimental data. A comparison of results from earlier workflows is used to show the importance of properly matching certain experimental parameters in the generated equilibria, including the normalized β, pedestal density, and q 95. On the other hand, the details of the pedestal current did not significantly impact the plasma response in these equilibria. A comparison to the experimentally measured plasma response shows mixed agreement, indicating that while the equilibria are predicted well, additional analysis tools may be needed. In conclusion, we note the implications that these results have for the success of future predict-first studies, particularly the need for scans of uncertain parameters and for close collaboration between experimentalists and theorists.« less

Predict-first experimental analysis using automated and integrated magnetohydrodynamic modeling

NASA Astrophysics Data System (ADS)

Lyons, B. C.; Paz-Soldan, C.; Meneghini, O.; Lao, L. L.; Weisberg, D. B.; Belli, E. A.; Evans, T. E.; Ferraro, N. M.; Snyder, P. B.

2018-05-01

An integrated-modeling workflow has been developed for the purpose of performing predict-first analysis of transient-stability experiments. Starting from an existing equilibrium reconstruction from a past experiment, the workflow couples together the EFIT Grad-Shafranov solver [L. Lao et al., Fusion Sci. Technol. 48, 968 (2005)], the EPED model for the pedestal structure [P. B. Snyder et al., Phys. Plasmas 16, 056118 (2009)], and the NEO drift-kinetic-equation solver [E. A. Belli and J. Candy, Plasma Phys. Controlled Fusion 54, 015015 (2012)] (for bootstrap current calculations) in order to generate equilibria with self-consistent pedestal structures as the plasma shape and various scalar parameters (e.g., normalized β, pedestal density, and edge safety factor [q95]) are changed. These equilibria are then analyzed using automated M3D-C1 extended-magnetohydrodynamic modeling [S. C. Jardin et al., Comput. Sci. Discovery 5, 014002 (2012)] to compute the plasma response to three-dimensional magnetic perturbations. This workflow was created in conjunction with a DIII-D experiment examining the effect of triangularity on the 3D plasma response. Several versions of the workflow were developed, and the initial ones were used to help guide experimental planning (e.g., determining the plasma current necessary to maintain the constant edge safety factor in various shapes). Subsequent validation with the experimental results was then used to revise the workflow, ultimately resulting in the complete model presented here. We show that quantitative agreement was achieved between the M3D-C1 plasma response calculated for equilibria generated by the final workflow and equilibria reconstructed from experimental data. A comparison of results from earlier workflows is used to show the importance of properly matching certain experimental parameters in the generated equilibria, including the normalized β, pedestal density, and q95. On the other hand, the details of the pedestal current did not significantly impact the plasma response in these equilibria. A comparison to the experimentally measured plasma response shows mixed agreement, indicating that while the equilibria are predicted well, additional analysis tools may be needed. Finally, we note the implications that these results have for the success of future predict-first studies, particularly the need for scans of uncertain parameters and for close collaboration between experimentalists and theorists.

Fast detection and low power hydrogen sensor using edge-oriented vertically aligned 3-D network of MoS2 flakes at room temperature

NASA Astrophysics Data System (ADS)

Agrawal, A. V.; Kumar, R.; Venkatesan, S.; Zakhidov, A.; Zhu, Z.; Bao, Jiming; Kumar, Mahesh; Kumar, Mukesh

2017-08-01

The increased usage of hydrogen as a next generation clean fuel strongly demands the parallel development of room temperature and low power hydrogen sensors for their safety operation. In this work, we report strong evidence for preferential hydrogen adsorption at edge-sites in an edge oriented vertically aligned 3-D network of MoS2 flakes at room temperature. The vertically aligned edge-oriented MoS2 flakes were synthesised by a modified CVD process on a SiO2/Si substrate and confirmed by Scanning Electron Microscopy. Raman spectroscopy and PL spectroscopy reveal the signature of few-layer MoS2 flakes in the sample. The sensor's performance was tested from room temperature to 150 °C for 1% hydrogen concentration. The device shows a fast response of 14.3 s even at room temperature. The sensitivity of the device strongly depends on temperature and increases from ˜1% to ˜11% as temperature increases. A detail hydrogen sensing mechanism was proposed based on the preferential hydrogen adsorption at MoS2 edge sites. The proposed gas sensing mechanism was verified by depositing ˜2-3 nm of ZnO on top of the MoS2 flakes that partially passivated the edge sites. We found a decrease in the relative response of MoS2-ZnO hybrid structures. This study provides a strong experimental evidence for the role of MoS2 edge-sites in the fast hydrogen sensing and a step closer towards room temperature, low power (0.3 mW), hydrogen sensor development.

Advanced vehicle dynamics of heavy trucks with the perspective of road safety

NASA Astrophysics Data System (ADS)

Trigell, Annika Stensson; Rothhämel, Malte; Pauwelussen, Joop; Kural, Karel

2017-10-01

This paper presents state-of-the art within advanced vehicle dynamics of heavy trucks with the perspective of road safety. The most common accidents with heavy trucks involved are truck against passenger cars. Safety critical situations are for example loss of control (such as rollover and lateral stability) and a majority of these occur during speed when cornering. Other critical situations are avoidance manoeuvre and road edge recovery. The dynamic behaviour of heavy trucks have significant differences compared to passenger cars and as a consequence, successful application of vehicle dynamic functions for enhanced safety of trucks might differ from the functions in passenger cars. Here, the differences between vehicle dynamics of heavy trucks and passenger cars are clarified. Advanced vehicle dynamics solutions with the perspective of road safety of trucks are presented, beginning with the topic vehicle stability, followed by the steering system, the braking system and driver assistance systems that differ in some way from that of passenger cars as well.

Compton Camera and Prompt Gamma Ray Timing: Two Methods for In Vivo Range Assessment in Proton Therapy

PubMed Central

Hueso-González, Fernando; Fiedler, Fine; Golnik, Christian; Kormoll, Thomas; Pausch, Guntram; Petzoldt, Johannes; Römer, Katja E.; Enghardt, Wolfgang

2016-01-01

Proton beams are promising means for treating tumors. Such charged particles stop at a defined depth, where the ionization density is maximum. As the dose deposit beyond this distal edge is very low, proton therapy minimizes the damage to normal tissue compared to photon therapy. Nevertheless, inherent range uncertainties cast doubts on the irradiation of tumors close to organs at risk and lead to the application of conservative safety margins. This constrains significantly the potential benefits of protons over photons. In this context, several research groups are developing experimental tools for range verification based on the detection of prompt gammas, a nuclear by-product of the proton irradiation. At OncoRay and Helmholtz-Zentrum Dresden-Rossendorf, detector components have been characterized in realistic radiation environments as a step toward a clinical Compton camera. On the one hand, corresponding experimental methods and results obtained during the ENTERVISION training network are reviewed. On the other hand, a novel method based on timing spectroscopy has been proposed as an alternative to collimated imaging systems. The first tests of the timing method at a clinical proton accelerator are summarized, its applicability in a clinical environment for challenging the current safety margins is assessed, and the factors limiting its precision are discussed. PMID:27148473

Edge Effects Influence the Abundance of the Invasive Halyomorpha halys (Hemiptera: Pentatomidae) in Woody Plant Nurseries.

PubMed

Venugopal, P Dilip; Martinson, Holly M; Bergmann, Erik J; Shrewsbury, Paula M; Raupp, Michael J

2015-06-01

The invasive brown marmorated stink bug, Halyomorpha halys (Stål), has caused severe economic losses in the United States and is also a major nuisance pest invading homes. In diverse woody plant nurseries, favored host plants may be attacked at different times of the season and in different locations in the field. Knowledge of factors influencing H. halys abundance and simple methods to predict where H. halys are found and cause damage are needed to develop effective management strategies. In this study, we examined H. halys abundance on plants in tree nurseries as a function of distance from field edges (edge and core samples) and documented the abundance in tree nurseries adjoining different habitat types (corn, soybean, residential areas, and production sod). We conducted timed counts for H. halys on 2,016 individual trees belonging to 146 unique woody plant cultivars at two commercial tree nurseries in Maryland. Across three years of sampling, we found that H. halys nymphs and adults were more abundant at field edges (0-5 m from edges) than in the core of fields (15-20 m from edges). Proximity of soybean fields was associated with high nymph and adult abundance. Results indicate that monitoring efforts and intervention tactics for this invasive pest could be restricted to field edges, especially those close to soybean fields. We show clearly that spatial factors, especially distance from edge, strongly influence H. halys abundance in nurseries. This information may greatly simplify the development of any future management strategies. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Structured Tracking for Safety, Security, and Privacy: Algorithms for Fusing Noisy Estimates from Sensor, Robot, and Camera Networks

DTIC Science & Technology

2009-07-23

negative log of the probability at each edge. 135 7.4 Simulation experiments All simulation experiments were implemented in Matlab and executed on PCs...Sensitivity . . . . 71 4.5 Experimental Results . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 4.5.1 Simulation Results...113 6.6.2 Estimator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 6.7 Simulation Results

Writing for Safety. Facilitating a Team Approach to Writing Operating Instructions. ANTA Leading Edge Training Case Study.

ERIC Educational Resources Information Center

Serle, Oenone

The Australian engineering company, Jaques, and Swinburne University of Technology conducted a joint project to write more than 190 operating instructions for the company's 77 employees. First, the university's Workplace Skills Unit (WSU) interviewed 75 production workers to identify their language, literacy, and training needs. The WSU negotiated…

76 FR 77981 - Build-A-Bear Workshop, Inc., Provisional Acceptance of a Settlement Agreement and Order

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-15

...), and (11). 6. The Chairs are defective because the sharp edges of the Chair's folding wooden frame can... Product Safety Act (``CPSA''). The Agreement and the incorporated attached Order resolve staff's... regulatory agency established pursuant to, and responsible for, the enforcement of the CPSA, 15 U.S.C. 2051...

Investigation of a Spin Transition in a LaCoO3 Single Crystal by the Method of X-Ray Magnetic Circular Dichroism at the Cobalt K- and L 2,3-Edges

NASA Astrophysics Data System (ADS)

Sikolenko, V. V.; Troyanchuk, I. O.; Karpinsky, D. V.; Rogalev, A.; Wilhelm, F.; Rosenberg, R.; Prabhakaran, D.; Efimova, E. A.; Efimov, V. V.; Tiutiunnikov, S. I.; Bobrikov, I. A.

2018-02-01

Spin transitions of cobalt ions in LaCoO3 single crystals have been studied by the method of X-ray magnetic circular dichroism (XMCD) at the K- and L 2,3-edges of Co3+ ions. The orbital momentum of cobalt ions obtained for the K-edge at the 3 d level in the region of the spin transition in the temperature range from 25 to 120 K increases by a factor of approximately 1.6, whereas the slope of the magnetization curve value in the same temperature range and magnetic field increases by a factor of more than 10. XMCD experiments at the cobalt L 2,3-edges demonstrate gradual growth of the ratio of the orbital momentum to the spin one L/ S from 0.48 to 0.53 in the temperature range from 60 K to 120 K.

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

PubMed

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.

14 CFR 29.303 - Factor of safety.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements General § 29.303 Factor of safety. Unless otherwise provided, a factor of safety of 1.5 must be used. This factor applies to external and inertia... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Factor of safety. 29.303 Section 29.303...

14 CFR 27.303 - Factor of safety.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements General § 27.303 Factor of safety. Unless otherwise provided, a factor of safety of 1.5 must be used. This factor applies to external and inertia... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Factor of safety. 27.303 Section 27.303...

Acoustic Receptivity of Mach 4.5 Boundary Layer with Leading- Edge Bluntness

NASA Technical Reports Server (NTRS)

Malik, Mujeeb R.; Balakumar, Ponnampalam

2007-01-01

Boundary layer receptivity to two-dimensional slow and fast acoustic waves is investigated by solving Navier-Stokes equations for Mach 4.5 flow over a flat plate with a finite-thickness leading edge. Higher order spatial and temporal schemes are employed to obtain the solution whereby the flat-plate leading edge region is resolved by providing a sufficiently refined grid. The results show that the instability waves are generated in the leading edge region and that the boundary-layer is much more receptive to slow acoustic waves (by almost a factor of 20) as compared to the fast waves. Hence, this leading-edge receptivity mechanism is expected to be more relevant in the transition process for high Mach number flows where second mode instability is dominant. Computations are performed to investigate the effect of leading-edge thickness and it is found that bluntness tends to stabilize the boundary layer. Furthermore, the relative significance of fast acoustic waves is enhanced in the presence of bluntness. The effect of acoustic wave incidence angle is also studied and it is found that the receptivity of the boundary layer on the windward side (with respect to the acoustic forcing) decreases by more than a factor of 4 when the incidence angle is increased from 0 to 45 deg. However, the receptivity coefficient for the leeward side is found to vary relatively weakly with the incidence angle.

A Role of the Reaction Kernel in Propagation and Stabilization of Edge Diffusion Flames of C1-C3 Hydrocarbons

NASA Technical Reports Server (NTRS)

Takahashi, Fumiaki; Katta, Viswanath R.

2003-01-01

Diffusion flame stabilization is of essential importance in both Earth-bound combustion systems and spacecraft fire safety. Local extinction, re-ignition, and propagation processes may occur as a result of interactions between the flame zone and vortices or fire-extinguishing agents. By using a computational fluid dynamics code with a detailed chemistry model for methane combustion, the authors have revealed the chemical kinetic structure of the stabilizing region of both jet and flat-plate diffusion flames, predicted the flame stability limit, and proposed diffusion flame attachment and detachment mechanisms in normal and microgravity. Because of the unique geometry of the edge of diffusion flames, radical back-diffusion against the oxygen-rich entrainment dramatically enhanced chain reactions, thus forming a peak reactivity spot, i.e., reaction kernel, responsible for flame holding. The new results have been obtained for the edge diffusion flame propagation and attached flame structure using various C1-C3 hydrocarbons.

Influence of edge conditions on material ejection from periodic grooves in laser shock-loaded tin

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rességuier, T. de; Roland, C.; Prudhomme, G.

2016-05-14

In a material subjected to high dynamic compression, the breakout of a shock wave at a rough free surface can lead to the ejection of high velocity debris. Anticipating the ballistic properties of such debris is a key safety issue in many applications involving shock loading, including pyrotechnics and inertial confinement fusion experiments. In this paper, we use laser driven shocks to investigate particle ejection from calibrated grooves of micrometric dimensions and approximately sinusoidal profile in tin samples, with various boundary conditions at the groove edges, including single groove and periodic patterns. Fast transverse shadowgraphy provides ejection velocities after shockmore » breakout. They are found to depend not only on the groove depth and wavelength, as predicted theoretically and already observed in the past, but also, unexpectedly, on the edge conditions, with a jet tip velocity significantly lower in the case of a single groove than behind a periodic pattern.« less

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

PubMed

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.

Investigating the radial structure of axisymmetric fluctuations in the TCV tokamak with local and global gyrokinetic GENE simulations

NASA Astrophysics Data System (ADS)

Merlo, G.; Brunner, S.; Huang, Z.; Coda, S.; Görler, T.; Villard, L.; Bañón Navarro, A.; Dominski, J.; Fontana, M.; Jenko, F.; Porte, L.; Told, D.

2018-03-01

Axisymmetric (n = 0) density fluctuations measured in the TCV tokamak are observed to possess a frequency f 0 which is either varying (radially dispersive oscillations) or a constant over a large fraction of the plasma minor radius (radially global oscillations) as reported in a companion paper (Z Huang et al, this issue). Given that f 0 scales with the sound speed and given the poloidal structure of density fluctuations, these oscillations were interpreted as Geodesic Acoustic Modes, even though f 0 is in fact smaller than the local linear GAM frequency {f}{GAM}. In this work we employ the Eulerian gyrokinetic code GENE to simulate TCV relevant conditions and investigate the nature and properties of these oscillations, in particular their relation to the safety factor profile. Local and global simulations are carried out and a good qualitative agreement is observed between experiments and simulations. By varying also the plasma temperature and density profiles, we conclude that a variation of the edge safety factor alone is not sufficient to induce a transition from global to radially inhomogeneous oscillations, as was initially suggested by experimental results. This transition appears instead to be the combined result of variations in the different plasma profiles, collisionality and finite machine size effects. Simulations also show that radially global GAM-like oscillations can be observed in all fluxes and fluctuation fields, suggesting that they are the result of a complex nonlinear process involving also finite toroidal mode numbers and not just linear global GAM eigenmodes.

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

PubMed

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.

Assessment of the Critical Parameters Influencing the Edge Stretchability of Advanced High-Strength Steel Sheet

NASA Astrophysics Data System (ADS)

Pathak, N.; Butcher, C.; Worswick, M.

2016-11-01

The edge formability of ferritic-martensitic DP (dual-phase) and ferritic-bainitic CP (complex-phase) steels was evaluated using a hole expansion test for different edge conditions. Hole expansion tests involving the standard conical punch as well as a custom flat punch were performed to investigate formability when the hole is expanded out-of-plane (conical punch) and in-plane using the flat punch. A range of edge conditions were considered, in order to isolate the influence of a range of factors thought to influence edge formability. The results demonstrate that work hardening and void damage at the sheared edge govern formability, while the sheared surface quality plays a minor or secondary role. A comparison of the edge stretching limits of DP and CP steels demonstrates the advantages of a ferritic-bainitic microstructure for forming operations with severe local deformation as in a stretch-flanging operation. A comparison of a traditional DP780 steel with a CP steel of similar strength showed that the edge stretching limit of the CP steel was three times larger than that of the DP780.

Structural Deterministic Safety Factors Selection Criteria and Verification

NASA Technical Reports Server (NTRS)

Verderaime, V.

1992-01-01

Though current deterministic safety factors are arbitrarily and unaccountably specified, its ratio is rooted in resistive and applied stress probability distributions. This study approached the deterministic method from a probabilistic concept leading to a more systematic and coherent philosophy and criterion for designing more uniform and reliable high-performance structures. The deterministic method was noted to consist of three safety factors: a standard deviation multiplier of the applied stress distribution; a K-factor for the A- or B-basis material ultimate stress; and the conventional safety factor to ensure that the applied stress does not operate in the inelastic zone of metallic materials. The conventional safety factor is specifically defined as the ratio of ultimate-to-yield stresses. A deterministic safety index of the combined safety factors was derived from which the corresponding reliability proved the deterministic method is not reliability sensitive. The bases for selecting safety factors are presented and verification requirements are discussed. The suggested deterministic approach is applicable to all NASA, DOD, and commercial high-performance structures under static stresses.

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

NASA Astrophysics Data System (ADS)

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.

Trailing edge flow conditions as a factor in airfoil design

NASA Technical Reports Server (NTRS)

Ormsbee, A. I.; Maughmer, M. D.

1984-01-01

Some new developments relevant to the design of single-element airfoils using potential flow methods are presented. In particular, the role played by the non-dimensional trailing edge velocity in design is considered and the relationship between the specified value and the resulting airfoil geometry is explored. In addition, the ramifications of the unbounded trailing edge pressure gradients generally present in the potential flow solution of the flow over an airfoil are examined, and the conditions necessary to obtain a class of airfoils having finite trailing edge pressure gradients developed. The incorporation of these conditions into the inverse method of Eppler is presented and the modified scheme employed to generate a number of airfoils for consideration. The detailed viscous analysis of airfoils having finite trailing edge pressure gradients demonstrates a reduction in the strong inviscid-viscid interactions generally present near the trailing edge of an airfoil.

Atomic Scattering Factor of the ASTRO-H (Hitomi) SXT Reflector Around the Gold's L Edges

NASA Technical Reports Server (NTRS)

Kikuchi, Naomichi; Kurashima, Sho; Ishida, Manabu; Iizuka, Ryo; Maeda, Yoshitomo; Hayashi, Takayuki; Okajima, Takashi; Matsumoto, Hironori; Mitsubishi, Ikuyuki; Saji, Shigetaka

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 beam-line Spring-8 BL01B1. We obtained atomic scattering factors f1 and f2 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 Henkes atomic scattering factor.

A Novel Wound Retractor Combining Continuous Irrigation and Barrier Protection Reduces Incisional Contamination in Colorectal Surgery.

PubMed

Papaconstantinou, Harry T; Ricciardi, Rocco; Margolin, David A; Bergamaschi, Roberto; Moesinger, Robert C; Lichliter, Warren E; Birnbaum, Elisa H

2018-03-09

Surgical site infection (SSI) remains a persistent and morbid problem in colorectal surgery. Key to its pathogenesis is the degree of intraoperative bacterial contamination at the surgical site. The purpose of this study was to evaluate a novel wound retractor at reducing bacterial contamination. A prospective multicenter pilot study utilizing a novel wound retractor combining continuous irrigation and barrier protection was conducted in patients undergoing elective colorectal resections. Culture swabs were collected from the incision edge prior to device placement and from the exposed and protected incision edge prior to device removal. The primary and secondary endpoints were the rate of enteric and overall bacterial contamination on the exposed incision edge as compared to the protected incision edge, respectively. The safety endpoint was the absence of serious device-related adverse events. A total of 86 patients were eligible for analysis. The novel wound retractor was associated with a 66% reduction in overall bacterial contamination at the protected incision edge compared to the exposed incision edge (11.9 vs. 34.5%, P < 0.001), and 71% reduction in enteric bacterial contamination (9.5% vs. 33.3%, P < 0.001). The incisional SSI rate was 2.3% in the primary analysis and 1.2% in those that completed the protocol. There were no adverse events attributed to device use. A novel wound retractor combining continuous irrigation and barrier protection was associated with a significant reduction in bacterial contamination. Improved methods to counteract wound contamination represent a promising strategy for SSI prevention (NCT 02413879).

2009 Human Factors and Roadway Safety Workshop : Teen Driver Safety [SD .WMV (720x480/29fps/177.0 MB)

DOT National Transportation Integrated Search

2009-11-05

Iowa Department of Transportation Research and Technology Bureau video presentation from the 2009 human factors and roadway safety workshop session titled: Teen Driver Safety : Keynote Speaker Dan McGehee, director, Human Factors & Vehicle Safety Res...

A structural equation modelling approach examining the pathways between safety climate, behaviour performance and workplace slipping

PubMed Central

Swedler, David I; Verma, Santosh K; Huang, Yueng-Hsiang; Lombardi, David A; Chang, Wen-Ruey; Brennan, Melayne; Courtney, Theodore K

2015-01-01

Objective Safety climate has previously been associated with increasing safe workplace behaviours and decreasing occupational injuries. This study seeks to understand the structural relationship between employees’ perceptions of safety climate, performing a safety behaviour (ie, wearing slip-resistant shoes) and risk of slipping in the setting of limited-service restaurants. Methods At baseline, we surveyed 349 employees at 30 restaurants for their perceptions of their safety training and management commitment to safety as well as demographic data. Safety performance was identified as wearing slip-resistant shoes, as measured by direct observation by the study team. We then prospectively collected participants’ hours worked and number of slips weekly for the next 12 weeks. Using a confirmatory factor analysis, we modelled safety climate as a higher order factor composed of previously identified training and management commitment factors. Results The 349 study participants experienced 1075 slips during the 12-week follow-up. Confirmatory factor analysis supported modelling safety climate as a higher order factor composed of safety training and management commitment. In a structural equation model, safety climate indirectly affected prospective risk of slipping through safety performance, but no direct relationship between safety climate and slips was evident. Conclusions Results suggest that safety climate can reduce workplace slips through performance of a safety behaviour as well as suggesting a potential causal mechanism through which safety climate can reduce workplace injuries. Safety climate can be modelled as a higher order factor composed of safety training and management commitment. PMID:25710968

14 CFR 23.303 - Factor of safety.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Factor of safety. 23.303 Section 23.303... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure General § 23.303 Factor of safety. Unless otherwise provided, a factor of safety of 1.5 must be used. ...

What you see is what you step: the horizontal-vertical illusion increases toe clearance in older adults during stair ascent.

PubMed

Foster, Richard J; Whitaker, David; Scally, Andrew J; Buckley, John G; Elliott, David B

2015-05-01

Falls on stairs are a significant cause of morbidity and mortality in elderly people. A simple safety strategy to avoid tripping on stairs is increasing foot clearance. We determined whether a horizontal-vertical illusion superimposed onto stairs to create an illusory perceived increase in stair-riser height would increase stair ascent foot clearance in older participants. Preliminary experiments determined the optimum parameters for the horizontal-vertical illusion. Fourteen older adults (mean age ± 1 SD, 68.5 ± 7.4 years) ascended a three-step staircase with the optimized version of the horizontal-vertical illusion (spatial frequency: 12 cycles per stair riser) positioned either on the bottom or top stair only, or on the bottom and top stair simultaneously. These were compared to a control condition, which had a plain stair riser with edge highlighters positioned flush with each stair-tread edge. Foot clearance and measures of postural stability were compared across conditions. The optimized illusion on the bottom and top stair led to a significant increase in foot clearance over the respective stair edge, compared to the control condition. There were no significant decreases in postural stability. An optimized horizontal-vertical visual illusion led to significant increases in foot clearance in older adults when ascending a staircase, but the effects did not destabilize their postural stability. Inclusion of the horizontal-vertical illusion on raised surfaces (e.g., curbs) or the bottom and top stairs of staircases could improve stair ascent safety in older adults.

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

PubMed

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.

Lorentz factor determination for local electric fields in semiconductor devices utilizing hyper-thin dielectrics

DOE Office of Scientific and Technical Information (OSTI.GOV)

McPherson, J. W., E-mail: mcpherson.reliability@yahoo.com

The local electric field (the field that distorts, polarizes, and weakens polar molecular bonds in dielectrics) has been investigated for hyper-thin dielectrics. Hyper-thin dielectrics are currently required for advanced semiconductor devices. In the work presented, it is shown that the common practice of using a Lorentz factor of L = 1/3, to describe the local electric field in a dielectric layer, remains valid for hyper-thin dielectrics. However, at the very edge of device structures, a rise in the macroscopic/Maxwell electric field E{sub diel} occurs and this causes a sharp rise in the effective Lorentz factor L{sub eff}. At capacitor and transistor edges,more » L{sub eff} is found to increase to a value 2/3 < L{sub eff} < 1. The increase in L{sub eff} results in a local electric field, at device edge, that is 50%–100% greater than in the bulk of the dielectric. This increase in local electric field serves to weaken polar bonds thus making them more susceptible to breakage by standard Boltzmann and/or current-driven processes. This has important time-dependent dielectric breakdown (TDDB) implications for all electronic devices utilizing polar materials, including GaN devices that suffer from device-edge TDDB.« less

Strain Gage Load Calibration of the Wing Interface Fittings for the Adaptive Compliant Trailing Edge Flap Flight Test

NASA Technical Reports Server (NTRS)

Miller, Eric J.; Holguin, Andrew C.; Cruz, Josue; Lokos, William A.

2014-01-01

This is the presentation to follow conference paper of the same name. The adaptive compliant trailing edge (ACTE) flap experiment safety of flight requires that the flap to wing interface loads be sensed and monitored in real time to ensure that the wing structural load limits are not exceeded. This paper discusses the strain gage load calibration testing and load equation derivation methodology for the ACTE interface fittings. Both the left and right wing flap interfaces will be monitored and each contains four uniquely designed and instrumented flap interface fittings. The interface hardware design and instrumentation layout are discussed. Twenty one applied test load cases were developed using the predicted in-flight loads for the ACTE experiment.

Factors influencing perceived angular velocity.

PubMed

Kaiser, M K; Calderone, J B

1991-11-01

The assumption that humans are able to perceive and process angular kinematics is critical to many structure-from-motion and optical flow models. The current studies investigate this sensitivity, and examine several factors likely to influence angular velocity perception. In particular, three factors are considered: (1) the extent to which perceived angular velocity is determined by edge transitions of surface elements, (2) the extent to which angular velocity estimates are influenced by instantaneous linear velocities of surface elements, and (3) whether element-velocity effects are related to three-dimensional (3-D) tangential velocities or to two-dimensional (2-D) image velocities. Edge-transition rate biased angular velocity estimates only when edges were highly salient. Element velocities influenced perceived angular velocity; this bias was related to 2-D image velocity rather than 3-D tangential velocity. Despite these biases, however, judgments were most strongly determined by the true angular velocity. Sensitivity to this higher order motion parameter was surprisingly good, for rotations both in depth (y-axis) and parallel to the line of sight (z-axis).

Organizational factors affecting safety implementation in food companies in Thailand.

PubMed

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.

Investigation of structural factors of safety for the space shuttle

NASA Technical Reports Server (NTRS)

1972-01-01

A study was made of the factors governing the structural design of the fully reusable space shuttle booster to establish a rational approach to select optimum structural factors of safety. The study included trade studies of structural factors of safety versus booster service life, weight, cost, and reliability. Similar trade studies can be made on other vehicles using the procedures developed. The major structural components of a selected baseline booster were studied in depth, each being examined to determine the fatigue life, safe-life, and fail-safe capabilities of the baseline design. Each component was further examined to determine its reliability and safety requirements, and the change of structural weight with factors of safety. The apparent factors of safety resulting from fatigue, safe-life, proof test, and fail-safe requirements were identified. The feasibility of reduced factors of safety for design loads such as engine thrust, which are well defined, was examined.

14 CFR 31.25 - Factor of safety.

Code of Federal Regulations, 2010 CFR

2010-01-01

... envelope stress. (c) A factor of safety of at least five must be used in the design of all fibrous or non... any single failure will not jeopardize safety of flight. (d) In applying factors of safety, the effect...

14 CFR 25.303 - Factor of safety.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Factor of safety. 25.303 Section 25.303... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure General § 25.303 Factor of safety. Unless otherwise specified, a factor of safety of 1.5 must be applied to the prescribed limit load which are considered...

Correlation between crash avoidance maneuvers and injury severity sustained by motorcyclists in single-vehicle crashes.

PubMed

Wang, Chen; Lu, Linjun; Lu, Jian; Wang, Tao

2016-01-01

In order to improve motorcycle safety, this article examines the correlation between crash avoidance maneuvers and injury severity sustained by motorcyclists, under multiple precrash conditions. Ten-year crash data for single-vehicle motorcycle crashes from the General Estimates Systems (GES) were analyzed, using partial proportional odds models (i.e., generalized ordered logit models). The modeling results show that "braking (no lock-up)" is associated with a higher probability of increased severity, whereas "braking (lock-up)" is associated with a higher probability of decreased severity, under all precrash conditions. "Steering" is associated with a higher probability of reduced injury severity when other vehicles are encroaching, whereas it is correlated with high injury severity under other conditions. "Braking and steering" is significantly associated with a higher probability of low severity under "animal encounter and object presence," whereas it is surprisingly correlated with high injury severity when motorcycles are traveling off the edge of the road. The results also show that a large number of motorcyclists did not perform any crash avoidance maneuvers or conducted crash avoidance maneuvers that are significantly associated with high injury severity. In general, this study suggests that precrash maneuvers are an important factor associated with motorcyclists' injury severity. To improve motorcycle safety, training/educational programs should be considered to improve safety awareness and adjust driving habits of motorcyclists. Antilock brakes and such systems are also promising, because they could effectively prevent brake lock-up and assist motorcyclists in maneuvering during critical conditions. This study also provides valuable information for the design of motorcycle training curriculum.

2007 Beyond SBIR Phase II: Bringing Technology Edge to the Warfighter

DTIC Science & Technology

2007-08-23

Systems Trade-Off Analysis and Optimization Verification and Validation On-Board Diagnostics and Self - healing Security and Anti-Tampering Rapid...verification; Safety and reliability analysis of flight and mission critical systems On-Board Diagnostics and Self - Healing Model-based monitoring and... self - healing On-board diagnostics and self - healing ; Autonomic computing; Network intrusion detection and prevention Anti-Tampering and Trust

Student Drivers and the Fiduciary Duty of School Boards

ERIC Educational Resources Information Center

Donlevy, James Kent; Gereluk, Dianne; Brandon, Jim; Patterson, Peggy

2017-01-01

Following "E.D.G. v. Hammer", Canadian law has held that school boards, although they have a fiduciary duty to their students, do not guarantee the safety of their students from the acts of their employees. The scope of that fiduciary duty is narrow, restricted to a board acting with disloyalty, in bad faith, or in a conflict of interest…

49 CFR 567.4 - Requirements for manufacturers of motor vehicles.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., or the door edge that meets the door-latch post, next to the driver's seating position, or if none of... applicable Federal motor vehicle safety, bumper, and theft prevention standards in effect on the date of... standards in effect on the date of manufacture shown above.” The expression “U.S.” or “U.S.A.” may be...

49 CFR 567.4 - Requirements for manufacturers of motor vehicles.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., or the door edge that meets the door-latch post, next to the driver's seating position, or if none of... applicable Federal motor vehicle safety, bumper, and theft prevention standards in effect on the date of... standards in effect on the date of manufacture shown above.” The expression “U.S.” or “U.S.A.” may be...

49 CFR 567.4 - Requirements for manufacturers of motor vehicles.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., or the door edge that meets the door-latch post, next to the driver's seating position, or if none of... applicable Federal motor vehicle safety, bumper, and theft prevention standards in effect on the date of... standards in effect on the date of manufacture shown above.” The expression “U.S.” or “U.S.A.” may be...

SLAC All Access: Laser Labs

ScienceCinema

Minitti, Mike; Woods, Mike

2018-05-23

From supermarket checkouts to video game consoles, lasers are ubiquitous in our lives. Here at SLAC, high-power lasers are critical to the cutting-edge research conducted at the laboratory. But, despite what you might imagine, SLAC's research lasers bear little resemblance to the blasters and phasers of science fiction. In this edition of All Access we put on our safety goggles for a peek at what goes on inside some of SLAC's many laser labs. LCLS staff scientist Mike Minitti and SLAC laser safety officer Mike Woods detail how these lasers are used to study the behavior of subatomic particles, broaden our understanding of cosmic rays and even unlock the mysteries of photosynthesis.

Direct Detection Doppler Lidar for Spaceborne Wind Measurement

NASA Technical Reports Server (NTRS)

Korb, C. Laurence; Flesia, Cristina

1999-01-01

Aerosol and molecular based versions of the double-edge technique can be used for direct detection Doppler lidar spaceborne wind measurement. The edge technique utilizes the edge of a high spectral resolution filter for high accuracy wind measurement using direct detection lidar. The signal is split between an edge filter channel and a broadband energy monitor channel. The energy monitor channel is used for signal normalization. The edge measurement is made as a differential frequency measurement between the outgoing laser signal and the atmospheric backscattered return for each pulse. As a result the measurement is insensitive to laser and edge filter frequency jitter and drift at a level less than a few parts in 10(exp 10). We have developed double edge versions of the edge technique for aerosol and molecular-based lidar measurement of the wind. Aerosol-based wind measurements have been made at Goddard Space Flight Center and molecular-based wind measurements at the University of Geneva. We have demonstrated atmospheric measurements using these techniques for altitudes from 1 to more than 10 km. Measurement accuracies of better than 1.25 m/s have been obtained with integration times from 5 to 30 seconds. The measurements can be scaled to space and agree, within a factor of two, with satellite-based simulations of performance based on Poisson statistics. The theory of the double edge aerosol technique is described by a generalized formulation which substantially extends the capabilities of the edge technique. It uses two edges with opposite slopes located about the laser frequency at approximately the half-width of each edge filter. This doubles the signal change for a given Doppler shift and yields a factor of 1.6 improvement in the measurement accuracy compared to the single edge technique. The use of two high resolution edge filters substantially reduces the effects of Rayleigh scattering on the measurement, as much as order of magnitude, and allows the signal to noise ratio to be substantially improved in areas of low aerosol backscatter. We describe a method that allows the Rayleigh and aerosol components of the signal to be independently determined using the two edge channels and an energy monitor channel. The effects of Rayleigh scattering may then subtracted from the measurement and we show that the correction process does not significantly increase the measurement noise for Rayleigh to aerosol ratios up to 10. We show that for small Doppler shifts a measurement accuracy of 0.4 m/s can be obtained for 5000 detected photon, 1.2 m/s for 1000 detected photons, and 3.7 m/s for 50 detected photons for a Rayleigh to aerosol ratio of 5. Methods for increasing the dynamic range of the aerosol-based system to more than +/- 100 m/s are given.

Synergistic interactions between edge and area effects in a heavily fragmented landscape.

PubMed

Ewers, Robert M; Thorpe, Stephen; Didham, Raphael K

2007-01-01

Both area and edge effects have a strong influence on ecological processes in fragmented landscapes, but there is little understanding of how these two factors might interact to exacerbate local species declines. To test for synergistic interactions between area and edge effects, we sampled a diverse beetle community in a heavily fragmented landscape in New Zealand. More than 35,000 beetles of approximately 900 species were sampled over large gradients in habitat area (10(-2) 10(6) ha) and distance from patch edge (2(0)-2(10) m from the forest edge into both the forest and adjacent matrix). Using a new approach to partition variance following an ordination analysis, we found that a synergistic interaction between habitat area and distance to edge was a more important determinant of patterns in beetle community composition than direct edge or area effects alone. The strength of edge effects in beetle-species composition increased nonlinearly with increasing fragment area. One important consequence of the synergy is that the slopes of species area (SA) curves constructed from habitat islands depend sensitively on the distance from edge at which sampling is conducted. Surprisingly, we found negative SA curves for communities sampled at intermediate distances from habitat edges, caused by differential edge responses of matrix- vs. forest-specialist species in fragments of increasing area. Our data indicate that distance to habitat edge has a consistently greater impact on beetle community composition than habitat area and that variation in the strength of edge effects may underlie many patterns that are superficially related to habitat area.

Application of local indentations for film cooling of gas turbine blade leading edge

NASA Astrophysics Data System (ADS)

Petelchyts, V. Yu.; Khalatov, A. A.; Pysmennyi, D. N.; Dashevskyy, Yu. Ya.

2016-09-01

The paper presents results of computer simulation of the film cooling on the turbine blade leading edge model where the air coolant is supplied through radial holes and row of cylindrical inclined holes placed inside hemispherical dimples or trench. The blowing factor was varied from 0.5 to 2.0. The model size and key initial parameters for simulation were taken as for a real blade of a high-pressure high-performance gas turbine. Simulation was performed using commercial software code ANSYS CFX. The simulation results were compared with reference variant (no dimples or trench) both for the leading edge area and for the flat plate downstream of the leading edge.

Tuning energy relaxation along quantum Hall channels.

PubMed

Altimiras, C; le Sueur, H; Gennser, U; Cavanna, A; Mailly, D; Pierre, F

2010-11-26

The chiral edge channels in the quantum Hall regime are considered ideal ballistic quantum channels, and have quantum information processing potentialities. Here, we demonstrate experimentally, at a filling factor of ν(L)=2, the efficient tuning of the energy relaxation that limits quantum coherence and permits the return toward equilibrium. Energy relaxation along an edge channel is controllably enhanced by increasing its transmission toward a floating Ohmic contact, in quantitative agreement with predictions. Moreover, by forming a closed inner edge channel loop, we freeze energy exchanges in the outer channel. This result also elucidates the inelastic mechanisms at work at ν(L)=2, informing us, in particular, that those within the outer edge channel are negligible.

Edge grouping combining boundary and region information.

PubMed

Stahl, Joachim S; Wang, Song

2007-10-01

This paper introduces a new edge-grouping method to detect perceptually salient structures in noisy images. Specifically, we define a new grouping cost function in a ratio form, where the numerator measures the boundary proximity of the resulting structure and the denominator measures the area of the resulting structure. This area term introduces a preference towards detecting larger-size structures and, therefore, makes the resulting edge grouping more robust to image noise. To find the optimal edge grouping with the minimum grouping cost, we develop a special graph model with two different kinds of edges and then reduce the grouping problem to finding a special kind of cycle in this graph with a minimum cost in ratio form. This optimal cycle-finding problem can be solved in polynomial time by a previously developed graph algorithm. We implement this edge-grouping method, test it on both synthetic data and real images, and compare its performance against several available edge-grouping and edge-linking methods. Furthermore, we discuss several extensions of the proposed method, including the incorporation of the well-known grouping cues of continuity and intensity homogeneity, introducing a factor to balance the contributions from the boundary and region information, and the prevention of detecting self-intersecting boundaries.

Edge delamination in angle-ply composite laminates, part 5

NASA Technical Reports Server (NTRS)

Wang, S. S.

1981-01-01

A theoretical method was developed for describing the edge delamination stress intensity characteristics in angle-ply composite laminates. The method is based on the theory of anisotropic elasticity. The edge delamination problem is formulated using Lekhnitskii's complex-variable stress potentials and an especially developed eigenfunction expansion method. The method predicts exact orders of the three-dimensional stress singularity in a delamination crack tip region. With the aid of boundary collocation, the method predicts the complete stress and displacement fields in a finite-dimensional, delaminated composite. Fracture mechanics parameters such as the mixed-mode stress intensity factors and associated energy release rates for edge delamination can be calculated explicity. Solutions are obtained for edge delaminated (theta/-theta theta/-theta) angle-ply composites under uniform axial extension. Effects of delamination lengths, fiber orientations, lamination and geometric variables are studied.

Centrifugal Compressor Surge Margin Improved With Diffuser Hub Surface Air Injection

NASA Technical Reports Server (NTRS)

Skoch, Gary J.

2002-01-01

Aerodynamic stability is an important parameter in the design of compressors for aircraft gas turbine engines. Compression system instabilities can cause compressor surge, which may lead to the loss of an aircraft. As a result, engine designers include a margin of safety between the operating line of the engine and the stability limit line of the compressor. The margin of safety is typically referred to as "surge margin." Achieving the highest possible level of surge margin while meeting design point performance objectives is the goal of the compressor designer. However, performance goals often must be compromised in order to achieve adequate levels of surge margin. Techniques to improve surge margin will permit more aggressive compressor designs. Centrifugal compressor surge margin improvement was demonstrated at the NASA Glenn Research Center by injecting air into the vaned diffuser of a 4:1-pressure-ratio centrifugal compressor. Tests were performed using injector nozzles located on the diffuser hub surface of a vane-island diffuser in the vaneless region between the impeller trailing edge and the diffuser-vane leading edge. The nozzle flow path and discharge shape were designed to produce an air stream that remained tangent to the hub surface as it traveled into the diffuser passage. Injector nozzles were located near the leading edge of 23 of the 24 diffuser vanes. One passage did not contain an injector so that instrumentation located in that passage would be preserved. Several orientations of the injected stream relative to the diffuser vane leading edge were tested over a range of injected flow rates. Only steady flow (nonpulsed) air injection was tested. At 100 percent of the design speed, a 15-percent improvement in the baseline surge margin was achieved with a nozzle orientation that produced a jet that was bisected by the diffuser vane leading edge. Other orientations also improved the baseline surge margin. Tests were conducted at speeds below the design speed, and similar results were obtained. In most cases, the greatest improvement in surge margin occurred at fairly low levels of injected flow rate. Externally supplied injection air was used in these experiments. However, the injected flow rates that provided the greatest benefit could be produced using injection air that is recirculating between the diffuser discharge and nozzles located in the diffuser vaneless region. Future experiments will evaluate the effectiveness of recirculating air injection.

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

NASA Astrophysics Data System (ADS)

Kondo, G.; Yokoyama, N.; Yamada, S.; Hashimoto, Y.; Ohata, C.; Katsumoto, S.; Haruyama, J.

2017-12-01

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.

Beyond edge effects: landscape controls on forest structure in the southeastern US

NASA Astrophysics Data System (ADS)

Fagan, M. E.; Morton, D. C.; Cook, B.; Masek, J. G.; Zhao, F. A.; Nelson, R.; Huang, C.

2016-12-01

The structure of forest canopies (i.e., their height and complexity) is known to be influenced by a variety of factors, including forest age, species composition, disturbance, edaphic and topographical conditions, and exposure to edge environments. The combined impact of each of these factors on canopy structure is not well characterized for most forest ecosystems, however, which limits our ability to predict the regional impacts of forest fragmentation. The objective of this study was to elucidate the main biophysical drivers of canopy structure across two dominant ecosystems in the southeastern U.S: natural mixed deciduous forests, and industrial conifer plantations. We analyzed spatial changes in canopy structure along aerial transects of LiDAR data ( 3,000 km in all). High-resolution (1 m) LiDAR data from Goddard's LiDAR, Hyperspectral, and Thermal Airborne Imager (G-LiHT) were combined with time series of Landsat imagery to quantify forest type, age, composition, and fragmentation. Forest structural metrics (height, gap fraction, and canopy roughness) were examined across forest types, ages, topography, and decreasing edge exposure. We hypothesized that 1) structural edge effects would be weak in both natural and plantation forest types, and 2) age, composition, and topography would be the dominant influences on natural forest structure. We analyzed all large (>4 ha) fragments from the 8562 distinct forests measured during G-LiHT data collections in 2011 across the southeastern U.S. In general, the relationship between forest structural metrics and edge exposure was highly variable in both natural forests and plantations. However, variability in all structural metrics decreased with distance from an edge. Forest age and topography were strong predictors of canopy structure in natural forests. However plantations tended to be located in sites with limited topographical variation, and thinning disturbances of conifer plantations decreased the strength of the age-structure relationship. We found that canopy structure in our region is influenced by edge effects, but other factors played a larger role in determining forest characteristics. Our results highlight the importance of endogenous, stand-specific processes for forest structure, biomass, and biodiversity in the southeastern U.S.

Researches on Position Detection for Vacuum Switch Electrode

NASA Astrophysics Data System (ADS)

Dong, Huajun; Guo, Yingjie; Li, Jie; Kong, Yihan

2018-03-01

Form and transformation character of vacuum arc is important influencing factor on the vacuum switch performance, and the dynamic separations of electrode is the chief effecting factor on the transformation of vacuum arcs forms. Consequently, how to detect the position of electrode to calculate the separations in the arcs image is of great significance. However, gray level distribution of vacuum arcs image isn’t even, the gray level of burning arcs is high, but the gray level of electrode is low, meanwhile, the forms of vacuum arcs changes sharply, the problems above restrict electrode position detection precisely. In this paper, algorithm of detecting electrode position base on vacuum arcs image was proposed. The digital image processing technology was used in vacuum switch arcs image analysis, the upper edge and lower edge were detected respectively, then linear fitting was done using the result of edge detection, the fitting result was the position of electrode, thus, accurate position detection of electrode was realized. From the experimental results, we can see that: algorithm described in this paper detected upper and lower edge of arcs successfully and the position of electrode was obtained through calculation.

Edge-region grouping in figure-ground organization and depth perception.

PubMed

Palmer, Stephen E; Brooks, Joseph L

2008-12-01

Edge-region grouping (ERG) is proposed as a unifying and previously unrecognized class of relational information that influences figure-ground organization and perceived depth across an edge. ERG occurs when the edge between two regions is differentially grouped with one region based on classic principles of similarity grouping. The ERG hypothesis predicts that the grouped side will tend to be perceived as the closer, figural region. Six experiments are reported that test the predictions of the ERG hypothesis for 6 similarity-based factors: common fate, blur similarity, color similarity, orientation similarity, proximity, and flicker synchrony. All 6 factors produce the predicted effects, although to different degrees. In a 7th experiment, the strengths of these figural/depth effects were found to correlate highly with the strength of explicit grouping ratings of the same visual displays. The relations of ERG to prior results in the literature are discussed, and possible reasons for ERG-based figural/depth effects are considered. We argue that grouping processes mediate at least some of the effects we report here, although ecological explanations are also likely to be relevant in the majority of cases.

Edge-Region Grouping in Figure-Ground Organization and Depth Perception

PubMed Central

Palmer, Stephen E.; Brooks, Joseph L.

2008-01-01

Edge-region grouping (ERG) is proposed as a unifying and previously unrecognized class of relational information that influences figure-ground organization and perceived depth across an edge. ERG occurs when the edge between two regions is differentially grouped with one region based on classic principles of similarity grouping. The ERG hypothesis predicts that the grouped side will tend to be perceived as the closer, figural region. Six experiments are reported that test the predictions of the ERG hypothesis for six similarity-based factors: common fate, blur similarity, color similarity, orientation similarity, proximity, and flicker synchrony. All six factors produce the predicted effects, although to different degrees. In the seventh experiment, the strengths of these figural/depth effects were found to correlate highly with the strength of explicit grouping ratings of the same visual displays. The relations of ERG to prior results in the literature are discussed, and possible reasons for ERG-based figural/depth effects are considered. We argue that grouping processes mediate at least some of the effects we report here, although ecological explanations are also likely to be relevant in the majority of cases. PMID:19045980

An examination of the impact of five grade crossing safety factors on driver decision making

DOT National Transportation Integrated Search

2014-04-01

The authors applied signal detection theory to model the impact : of five grade-crossing safety factors to understand their impact : on driver decision making. The safety factors were improving : commercial motor vehicle (CMV) driver safety through f...

Observations of the effect of lower hybrid waves on ELM behaviour in EAST

NASA Astrophysics Data System (ADS)

Chen, R.; Xu, G. S.; Liang, Y.; Wang, H. Q.; Zhou, C.; Liu, A. D.; Wang, L.; Qian, J. P.; Gan, K. F.; Yang, J. H.; Duan, Y. M.; Li, Y. L.; Ding, S. Y.; Wu, X. Q.; Yan, N.; Chen, L.; Shao, L. M.; Zhang, W.; Hu, G. H.; Zhao, N.; Liu, S. C.; Kong, D. F.; Gong, X. Z.

2015-03-01

Dedicated experiments focusing on the influence of lower hybrid waves (LHWs) on edge-localized modes (ELMs) were first performed during the 2012 experimental campaign of EAST, via modulating the input power of LHWs in the high-confinement-mode (H-mode) plasma mainly sustained by ion cyclotron resonant heating. Natural ELMs are effectively mitigated (ELM frequency increases, while its intensity decreases dramatically) as the LHW is applied, observed over a fairly wide range of plasma current or edge safety factor. By scanning the modulation frequency (fm) of LHW injected power in a target plasma dominated by the so-called small ELMs, we conclude that large ELMs with markedly larger amplitudes and lower frequencies are reproduced at low modulation frequencies (fm < 100 Hz). Analysis of the evolution of edge extreme ultraviolet radiation signals further indicates that plasma fluctuations at the pedestal region indistinctively respond to rapid modulation (fm ⩾ 100 Hz) of LHW injected power. This is proposed as the mechanism responsible for the observed fm dependence of the mitigation effect induced by LHWs on large ELMs. In addition, a critical threshold of LHW input power PLHW is estimated as PLHWthr≃800 kW , beyond which the impact of applied LHWs on ELM behaviours can be achieved. Finally, Langmuir probe measurements suggest that, rather than the concentration of free energy into a narrowband quasi-coherent precursor commonly observed growing until the ELM crash, the continuous development of broadband turbulence during the ELM-absent phase with the application of LHWs might contribute to the avoidance of ELM crashes. These results present new insights into existing experiments, and also provide some foundations and references for the next-step research about exploring in more depth and improving this new attractive method to effectively control the ELM-induced very large transient heat and particle flux.

Internal and edge cracks in a plate of finite width under bending

NASA Technical Reports Server (NTRS)

Boduroglu, H.; Erdogan, F.

1983-01-01

In this paper the title problem is studied by using Reissner's transverse shear theory. The main purpose of the paper is to investigate the effect of stress-free boundaries on the stress intensity factors in plates under bending. Among the results found particularly interesting are those relating to the limiting cases of the crack geometries. The numerical results are given for a single internal crack, two collinear cracks, and two edge cracks. Also studied is the effect of Poisson's ratio on the stress intensity factors.

Finite element validation of stress intensity factor calculation models for thru-thickness and thumb-nail cracks in double edge notch specimens

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beres, W.; Koul, A.K.

1994-09-01

Stress intensity factors for thru-thickness and thumb-nail cracks in the double edge notch specimens, containing two different notch radius (R) to specimen width (W) ratios (R/W = 1/8 and 1/16), are calculated through finite element analysis. The finite element results are compared with predictions based on existing empirical models for SIF calculations. The effects of a change in R/W ratio on SIF of thru-thickness and thumb-nail cracks are also discussed. 34 refs.

Arthropods on plants in a fragmented Neotropical dry forest: a functional analysis of area loss and edge effects.

PubMed

González, Ezequiel; Salvo, Adriana; Valladares, Graciela

2015-02-01

Loss and fragmentation of natural ecosystems are widely recognized as the most important threats to biodiversity conservation, with Neotropical dry forests among the most endangered ecosystems. Area and edge effects are major factors in fragmented landscapes. Here, we examine area and edge effects and their interaction, on ensembles of arthropods associated to native vegetation in a fragmented Chaco Serrano forest. We analyzed family richness and community composition of herbivores, predators, and parasitoids on three native plant species in 12 fragments of varying size and at edge/interior positions. We also looked for indicator families by using Indicator Species Analysis. Loss of family richness with the reduction of forest fragment area was observed for the three functional groups, with similar magnitude. Herbivores were richer at the edges without interaction between edge and area effects, whereas predators were not affected by edge/interior position and parasitoid richness showed an interaction between area and position, with a steeper area slope at the edges. Family composition of herbivore, predator, and parasitoid assemblages was also affected by forest area and/or edge/interior situation. We found three indicator families for large remnants and five for edges. Our results support the key role of forest area for conservation of arthropods taxonomic and functional diversity in a highly threatened region, and emphasize the need to understand the interactions between area and edge effects on such diversity. © 2014 Institute of Zoology, Chinese Academy of Sciences.

Local and landscape scale factors influencing edge effects on woodland salamanders.

PubMed

Moseley, Kurtis R; Ford, W Mark; Edwards, John W

2009-04-01

We examined local and landscape-scale variable influence on the depth and magnitude of edge effects on woodland salamanders in mature mixed mesophytic and northern hardwood forest adjacent to natural gas well sites maintained as wildlife openings. We surveyed woodland salamander occurrence from June-August 2006 at 33 gas well sites in the Monongahela National Forest, West Virginia. We used an information-theoretic approach to test nine a priori models explaining landscape-scale effects on woodland salamander capture proportion within 20 m of field edge. Salamander capture proportion was greater within 0-60 m than 61-100 m of field edges. Similarly, available coarse woody debris proportion was greater within 0-60 m than 61-100 m of field edge. Our ASPECT model, that incorporated the single variable aspect, received the strongest support for explaining landscape-scale effects on salamander capture proportion within 20 m of opening edge. The ASPECT model indicated that fewer salamanders occurred within 20 m of opening edges on drier, hotter southwestern aspects than in moister, cooler northeastern aspects. Our results suggest that forest habitat adjacent to maintained edges and with sufficient cover still can provide suitable habitat for woodland salamander species in central Appalachian mixed mesophytic and northern hardwood forests. Additionally, our modeling results support the contention that edge effects are more severe on southwesterly aspects. These results underscore the importance of distinguishing among different edge types as well as placing survey locations within a landscape context when investigating edge impacts on woodland salamanders.

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

PubMed

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 (P<0.001) and workplace safety condition (P<0.001). The workplace safety condition was found to play a strong mediating role in linking the safety climate and construction workers' engagement in safe or unsafe behavior. In order to improve construction safety performance, more focus on the workplace condition is required.

Interrelation Between Safety Factors and Reliability

NASA Technical Reports Server (NTRS)

Elishakoff, Isaac; Chamis, Christos C. (Technical Monitor)

2001-01-01

An evaluation was performed to establish relationships between safety factors and reliability relationships. Results obtained show that the use of the safety factor is not contradictory to the employment of the probabilistic methods. In many cases the safety factors can be directly expressed by the required reliability levels. However, there is a major difference that must be emphasized: whereas the safety factors are allocated in an ad hoc manner, the probabilistic approach offers a unified mathematical framework. The establishment of the interrelation between the concepts opens an avenue to specify safety factors based on reliability. In cases where there are several forms of failure, then the allocation of safety factors should he based on having the same reliability associated with each failure mode. This immediately suggests that by the probabilistic methods the existing over-design or under-design can be eliminated. The report includes three parts: Part 1-Random Actual Stress and Deterministic Yield Stress; Part 2-Deterministic Actual Stress and Random Yield Stress; Part 3-Both Actual Stress and Yield Stress Are Random.

Quantitative evolutionary design

PubMed Central

Diamond, Jared

2002-01-01

The field of quantitative evolutionary design uses evolutionary reasoning (in terms of natural selection and ultimate causation) to understand the magnitudes of biological reserve capacities, i.e. excesses of capacities over natural loads. Ratios of capacities to loads, defined as safety factors, fall in the range 1.2-10 for most engineered and biological components, even though engineered safety factors are specified intentionally by humans while biological safety factors arise through natural selection. Familiar examples of engineered safety factors include those of buildings, bridges and elevators (lifts), while biological examples include factors of bones and other structural elements, of enzymes and transporters, and of organ metabolic performances. Safety factors serve to minimize the overlap zone (resulting in performance failure) between the low tail of capacity distributions and the high tail of load distributions. Safety factors increase with coefficients of variation of load and capacity, with capacity deterioration with time, and with cost of failure, and decrease with costs of initial construction, maintenance, operation, and opportunity. Adaptive regulation of many biological systems involves capacity increases with increasing load; several quantitative examples suggest sublinear increases, such that safety factors decrease towards 1.0. Unsolved questions include safety factors of series systems, parallel or branched pathways, elements with multiple functions, enzyme reaction chains, and equilibrium enzymes. The modest sizes of safety factors imply the existence of costs that penalize excess capacities. Those costs are likely to involve wasted energy or space for large or expensive components, but opportunity costs of wasted space at the molecular level for minor components. PMID:12122135

Contact lens-induced circumlimbal staining in silicone hydrogel contact lenses worn on a daily wear basis.

PubMed

Maïssa, Cécile; Guillon, Michel; Garofalo, Renee J

2012-01-01

The principal objective of the study was to measure the conjunctival staining produced in the circumlimbal region by silicone hydrogel contact lenses with different edge designs. The secondary objective was to investigate the association between circumlimbal staining and comfort. Four silicone hydrogel contact lenses: ACUVUE OASYS (knife edge design), AIR OPTIX, Biofinity (chisel edge rounded edge combination), and PureVision (rounded edge design), and 1 hydrogel contact lens, ACUVUE 2 (knife edge design), were tested. The study was conducted on a cohort population of 27 established soft contact lens wearers, who wore each contact lens type, in a random order, for a period of 10 (±2) days. Circumlimbal staining was measured in a double-masked fashion through image analysis of digital photographs of lissamine green taken under controlled experimental conditions. The results obtained showed that contact lens edge design was the primary factor controlling circumlimbal staining for silicone hydrogel lenses: a rounded edge away from the ocular surface produced the lowest staining (average, 0.19%) and a knife edge in close apposition to the ocular surface produced the highest staining (average, 1.34%). Contact lens material rigidity was also identified to affect circumlimbal staining and an inverse association between circumlimbal staining and contact lens comfort was demonstrated: the rounded edge design produced the lowest comfort (72 of 100) and the knife edge design produced the highest (87 out of 100). Soft contact lens wear induces circumlimbal staining, the level of staining being influenced by the contact lens edge design. However, high level of circumlimbal staining is not associated with decreased comfort.

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

NASA Astrophysics Data System (ADS)

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.

Development of a Standard to Objectively Define and Measure the End-to-End Quality of Teleconferencing/Videophone Systems

DTIC Science & Technology

1991-02-01

lines; and edge busyness , wherein the position of the edge appears to be moving when there is a rapid signal change . E - 3 APPENDIX Fl T|QI. 5/88-070...Some of the most important new and changed factors are as follows: o Motion must be introduced as a most important feature. o Motion artifacts must be...nominal audio level (measured to ground). edge busyness : The deterioration of motion video such that the outlines of moving objects are displayed with

Recent Results of IRAN-T1 Tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dorranian, D.; Ghoranneviss, M.; Salem, M. K.

2006-12-04

In this article after introducing the IR-T1 tokamak and its diagnostic systems a brief discussion on the range of grossly stable operating conditions of its plasma by Hugill diagram is presented. Hard disruption instability is studied experimentally in the next part, which confirms that MHD behavior in small tokamaks can be characterized by a single parameter q(a), safety factor at plasma edge. Finally the characteristics of the new regime of IR-T1 are reported. By our new model of triggering different fields (toroidal, ohmic and vertical), the plasma duration time is increased up to 35 ms with Ip of about 25more » kA. By modifying capacitance and charging voltage of ohmic and vertical fields the spike oscillations which was appeared in the plasma behavior is taken out. The role of cleaning the vacuum chamber and using heavier gas for glow discharge and the effect of base pressure is described in detail.« less

Non-axisymmetric equilibrium reconstruction on the Compact Toroidal Hybrid Experiment using external magnetic and soft x-ray inversion radius measurements

NASA Astrophysics Data System (ADS)

Ma, X.; Cianciosa, M.; Hanson, J. D.; Hartwell, G. J.; Knowlton, S. F.; Maurer, D. A.; Ennis, D. A.; Herfindal, J. L.

2015-11-01

Non-axisymmetric free-boundary equilibrium reconstructions of stellarator plasmas are performed for discharges in which the magnetic configuration is strongly modified by the driven plasma current. Studies were performed on the Compact Toroidal Hybrid device using the V3FIT reconstruction code incorporating a set of 50 magnetic diagnostics external to the plasma, combined with information from soft X-ray (SXR) arrays. With the assumption of closed magnetic flux surfaces, the reconstructions using external magnetic measurements allow accurate estimates of the net toroidal flux within the last closed flux surface, the edge safety factor, and the outer boundary of these highly non-axisymmetric plasmas. The inversion radius for sawtoothing plasmas is used to identify the location of the q = 1 surface, and thus infer the current profile near the magnetic axis. With external magnetic diagnostics alone, we find the reconstruction to be insufficiently constrained. This work is supported by US Department of Energy Grant No. DE-FG02-00ER54610.

AANA Journal course: update for nurse anesthetists--ERR WATCH: anesthesia crisis resource management from the nurse anesthetist's perspective.

PubMed

Fletcher, J L

1998-12-01

Anesthesia crisis resource management (ACRM) was developed by David Gaba, MD, and colleagues at Stanford University in the early 1990s. Derived from cockpit resource management of the aviation industry, ACRM addresses the issues of human performance and patient safety in anesthesia. Due to the inherent complexity of our dynamic work environment, we are frequently faced with situations that could escalate into critical incidents. ACRM explains the role of personal and environmental factors that can contribute to the evolution of critical incidents and provides the practitioner with some behavioral and intellectual guidelines to manage the risks more effectively. ERR WATCH is an acronym I developed to interpret the principles of ACRM from the nurse anesthetist's perspective. It provides a quick review of the major principles of ACRM, which are Environment, Resources, Reevaluation, Workload, Attention, Teamwork, Communication, and Help. Used together with good clinical management, these principles may provide an edge in solving complex problems and improving performance.

Transport barriers in bootstrap-driven tokamaks

NASA Astrophysics Data System (ADS)

Staebler, G. M.; Garofalo, A. M.; Pan, C.; McClenaghan, J.; Van Zeeland, M. A.; Lao, L. L.

2018-05-01

Experiments have demonstrated improved energy confinement due to the spontaneous formation of an internal transport barrier in high bootstrap fraction discharges. Gyrokinetic analysis, and quasilinear predictive modeling, demonstrates that the observed transport barrier is caused by the suppression of turbulence primarily from the large Shafranov shift. It is shown that the Shafranov shift can produce a bifurcation to improved confinement in regions of positive magnetic shear or a continuous reduction in transport for weak or negative magnetic shear. Operation at high safety factor lowers the pressure gradient threshold for the Shafranov shift-driven barrier formation. Two self-organized states of the internal and edge transport barrier are observed. It is shown that these two states are controlled by the interaction of the bootstrap current with magnetic shear, and the kinetic ballooning mode instability boundary. Election scale energy transport is predicted to be dominant in the inner 60% of the profile. Evidence is presented that energetic particle-driven instabilities could be playing a role in the thermal energy transport in this region.

Experimental tests of linear and nonlinear three-dimensional equilibrium models in DIII-D

DOE PAGES

King, Josh D.; Strait, Edward J.; Lazerson, Samuel A.; ...

2015-07-01

DIII-D experiments using new detailed magnetic diagnostics show that linear, ideal magnetohydrodynamics (MHD) theory quantitatively describes the magnetic structure (as measured externally) of three-dimensional (3D) equilibria resulting from applied fields with toroidal mode number n = 1, while a nonlinear solution to ideal MHD force balance, using the VMEC code, requires the inclusion of n ≥ 1 to achieve similar agreement. Moreover, these tests are carried out near ITER baseline parameters, providing a validated basis on which to exploit 3D fields for plasma control development. We determine scans of the applied poloidal spectrum and edge safety factors which confirm thatmore » low-pressure, n = 1 non-axisymmetric tokamak equilibria are a single, dominant, stable eigenmode. But, at higher beta, near the ideal kink mode stability limit in the absence of a conducting wall, the qualitative features of the 3D structure are observed to vary in a way that is not captured by ideal MHD.« less

A Factor Affecting Transonic Leading-edge Flow Separation

NASA Technical Reports Server (NTRS)

Wood, George P; Gooderum, Paul B

1956-01-01

A change in flow pattern that was observed as the free-stream Mach number was increased in the vicinity of 0.8 was described in NACA Technical Note 1211 by Lindsey, Daley, and Humphreys. The flow on the upper surface behind the leading edge of an airfoil at an angle of attack changed abruptly from detached flow with an extensive region of separation to attached supersonic flow terminated by a shock wave. In the present paper, the consequences of shock-wave - boundary layer interaction are proposed as a factor that may be important in determining the conditions under which the change in flow pattern occurs. Some experimental evidence in support of the importance of this factor is presented.

Measuring safety climate in elderly homes.

PubMed

Yeung, Koon-Chuen; Chan, Charles C

2012-02-01

Provision of a valid and reliable safety climate dimension brings enormous benefits to the elderly home sector. The aim of the present study was to make use of the safety climate instrument developed by OSHC to measure the safety perceptions of employees in elderly homes such that the factor structure of the safety climate dimensions of elderly homes could be explored. In 2010, surveys by mustering on site method were administered in 27 elderly homes that had participated in the "Hong Kong Safe and Healthy Residential Care Home Accreditation Scheme" organized by the Occupational Safety and Health Council. Six hundred and fifty-one surveys were returned with a response rate of 54.3%. To examine the factor structure of safety climate dimensions in our study, an exploratory factor analysis (EFA) using principal components analysis method was conducted to identify the underlying factors. The results of the modified seven-factor's safety climate structure extracted from 35 items better reflected the safety climate dimensions of elderly homes. The Cronbach alpha range for this study (0.655 to 0.851) indicated good internal consistency among the seven-factor structure. Responses from managerial level, supervisory and professional level, and front-line staff were analyzed to come up with the suggestion on effective ways of improving the safety culture of elderly homes. The overall results showed that managers generally gave positive responses in the factors evaluated, such as "management commitment and concern to safety," "perception of work risks and some contributory influences," "safety communication and awareness," and "safe working attitude and participation." Supervisors / professionals, and frontline level staff on the other hand, have less positive responses. The result of the lowest score in the factors - "perception of safety rules and procedures" underlined the importance of the relevance and practicability of safety rules and procedures. The modified OSHC safety climate tool provided better evidence of structural validity and reliability for use by elderly homes' decision makers as an indicator of employee perception of safety in their institution. The findings and suggestions in the study provide useful information for the management, supervisors/professionals and frontline level staff to cultivate the safety culture in the elderly home sector. Most important, elderly homes can use the modified safety climate scale to identify problem areas in their safety culture and safety management practices and then target these for intervention. Copyright © 2012 Elsevier Ltd. All rights reserved.

Images Revealing More Than a Thousand Words

NASA Technical Reports Server (NTRS)

2003-01-01

A unique sensor developed by ProVision Technologies, a NASA Commercial Space Center housed by the Institute for Technology Development, produces hyperspectral images with cutting-edge applications in food safety, skin health, forensics, and anti-terrorism activities. While hyperspectral imaging technology continues to make advances with ProVision Technologies, it has also been transferred to the commercial sector through a spinoff company, Photon Industries, Inc.

49 CFR 231.28 - Box and other house cars with roof hatches built or placed in service after October 1, 1966.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Box and other house cars with roof hatches built... RAILROAD SAFETY APPLIANCE STANDARDS § 231.28 Box and other house cars with roof hatches built or placed in... fifteen (15) inches from edge of roof, except on refrigerator cars where ice hatches prevent, when...

49 CFR 231.28 - Box and other house cars with roof hatches built or placed in service after October 1, 1966.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Box and other house cars with roof hatches built... RAILROAD SAFETY APPLIANCE STANDARDS § 231.28 Box and other house cars with roof hatches built or placed in... fifteen (15) inches from edge of roof, except on refrigerator cars where ice hatches prevent, when...

Development Program for Field-Repairable/Expendable Main Rotor Blades

DTIC Science & Technology

1976-09-01

honeycomb aft 2, and it represents the most cost- core, and extruded aluminum alloy effective approach to a repairable trailing-edge spline (Reference...materials lend themselves to relatively inexpensive fabrication techniques, the questionable torsional stiffness of composite spars eliminated them...values of the fatigue strength of aluminum , the spline and aft doublers are predicted to have a negative margin of safety for infinite life. The

The predicaments of “dangerous safety”

PubMed Central

Feudtner, Chris

2000-01-01

Remedies are not useless because they fall short of their full scope. It is better to keep a man on the edge of a precipice, if you cannot pluck him away from it, than to let him fall over. And many diabetic patients are kept in this predicament of dangerous safety. Lectures on the Principles and Practice of Physic, 1836-1837 SirThomas Watson PMID:10903304

Dimensions of Safety Climate among Iranian Nurses.

PubMed

Konjin, Z Naghavi; Shokoohi, Y; Zarei, F; Rahimzadeh, M; Sarsangi, V

2015-10-01

Workplace safety has been a concern of workers and managers for decades. Measuring safety climate is crucial in improving safety performance. It is also a method of benchmarking safety perception. To develop and validate a psychometrics scale for measuring nurses' safety climate. Literature review, subject matter experts and nurse's judgment were used in items developing. Content validity and reliability for new tool were tested by content validity index (CVI) and test-retest analysis, respectively. Exploratory factor analysis (EFA) with varimax rotation was used to improve the interpretation of latent factors. A 40-item scale in 6 factors was developed, which could explain 55% of the observed variance. The 6 factors included employees' involvement in safety and management support, compliance with safety rules, safety training and accessibility to personal protective equipment, hindrance to safe work, safety communication and job pressure, and individual risk perception. The proposed scale can be used in identifying the needed areas to implement interventions in safety climate of nurses.

ASRM Case Insulation development

NASA Technical Reports Server (NTRS)

Tam, W. F. S.; Bell, M.

1993-01-01

The ASRM Case Insulation Program used design of experiments to develop a high performance case insulation. The program traded-off more than thirty properties in areas of ablation performance, material properties, processibility, bonding/aging. Kevlar pulp was found to be the most significant factor. The low-molecular weight ethylene propylene diene monomer, EPDM was the second most significant factor. The curative was the third most significant factor. The tackifier was the fourth most significant factor. The stripwinding process for applying the insulation onto the case inner surfaces was also studied. The parameters selected for experiment were extruder speed, upper roller temperature and extruder nozzle temperature. The extrudability results showed that non-Kevlar filled formulations displayed optimum edges but poor thickness continuity. High Kevlar filled formulations displayed optimum thickness continuity but poor strip edge ratings.

ASRM Case Insulation development

NASA Astrophysics Data System (ADS)

Tam, W. F. S.; Bell, M.

1993-06-01

The ASRM Case Insulation Program used design of experiments to develop a high performance case insulation. The program traded-off more than thirty properties in areas of ablation performance, material properties, processibility, bonding/aging. Kevlar pulp was found to be the most significant factor. The low-molecular weight ethylene propylene diene monomer, EPDM was the second most significant factor. The curative was the third most significant factor. The tackifier was the fourth most significant factor. The stripwinding process for applying the insulation onto the case inner surfaces was also studied. The parameters selected for experiment were extruder speed, upper roller temperature and extruder nozzle temperature. The extrudability results showed that non-Kevlar filled formulations displayed optimum edges but poor thickness continuity. High Kevlar filled formulations displayed optimum thickness continuity but poor strip edge ratings.

SU-E-T-469: A Practical Approach for the Determination of Small Field Output Factors Using Published Monte Carlo Derived Correction Factors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calderon, E; Siergiej, D

2014-06-01

Purpose: Output factor determination for small fields (less than 20 mm) presents significant challenges due to ion chamber volume averaging and diode over-response. Measured output factor values between detectors are known to have large deviations as field sizes are decreased. No set standard to resolve this difference in measurement exists. We observed differences between measured output factors of up to 14% using two different detectors. Published Monte Carlo derived correction factors were used to address this challenge and decrease the output factor deviation between detectors. Methods: Output factors for Elekta's linac-based stereotactic cone system were measured using the EDGE detectormore » (Sun Nuclear) and the A16 ion chamber (Standard Imaging). Measurements conditions were 100 cm SSD (source to surface distance) and 1.5 cm depth. Output factors were first normalized to a 10.4 cm × 10.4 cm field size using a daisy-chaining technique to minimize the dependence of field size on detector response. An equation expressing the relation between published Monte Carlo correction factors as a function of field size for each detector was derived. The measured output factors were then multiplied by the calculated correction factors. EBT3 gafchromic film dosimetry was used to independently validate the corrected output factors. Results: Without correction, the deviation in output factors between the EDGE and A16 detectors ranged from 1.3 to 14.8%, depending on cone size. After applying the calculated correction factors, this deviation fell to 0 to 3.4%. Output factors determined with film agree within 3.5% of the corrected output factors. Conclusion: We present a practical approach to applying published Monte Carlo derived correction factors to measured small field output factors for the EDGE and A16 detectors. Using this method, we were able to decrease the percent deviation between both detectors from 14.8% to 3.4% agreement.« less

Safety leadership in the teaching laboratories of electrical and electronic engineering departments at Taiwanese Universities.

PubMed

Wu, Tsung-Chih

2008-01-01

Safety has always been one of the principal goals in teaching laboratories. Laboratories cannot serve their educational purpose when accidents occur. The leadership of department heads has a major impact on laboratory safety, so this study discusses the factors affecting safety leadership in teaching laboratories. This study uses a mail survey to explore the perceived safety leadership in electrical and electronic engineering departments at Taiwanese universities. An exploratory factor analysis shows that there are three main components of safety leadership, as measured on a safety leadership scale: safety controlling, safety coaching, and safety caring. The descriptive statistics also reveals that among faculty, the perception of department heads' safety leadership is in general positive. A two-way MANOVA shows that there are interaction effects on safety leadership between university size and instructor age; there are also interaction effects between presence of a safety committee and faculty gender and faculty age. It is therefore necessary to assess organizational factors when determining whether individual factors are the cause of differing perceptions among faculty members. The author also presents advice on improving safety leadership for department heads at small universities and at universities without safety committees.

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

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-16

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Parts...: Control Room Management/Human Factors AGENCY: Pipeline and Hazardous Materials Safety Administration... safety standards, risk assessments, and safety policies for natural gas pipelines and for hazardous...

Investigating the radial structure of axisymmetric fluctuations in the TCV tokamak with local and global gyrokinetic GENE simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Merlo, Gabriele; Brunner, Stephan; Huang, Zhouji

Axisymmetric (n=0) density fluctuations measured in the TCV tokamak are observed to possess a frequency f₀ which is either varying (radially dispersive oscillations) or a constant over a large fraction of the plasma minor radius (radially global oscillations) as reported in a companion paper [Z. Huang et al., this issue]. Given that f₀ scales with the sound speed and given the poloidal structure of density fluctuations, these oscillations were interpreted as Geodesic Acoustic Modes, even though f₀ is in fact smaller than the local linear GAM frequency f_GAM . In this work we employ the Eulerian gyrokinetic code GENE tomore » simulate TCV relevant conditions and investigate the nature properties of these oscillations, in particular their relation to the safety factor profile. Local and global simulations are carried out and a good qualitative agreement is observed between experiments and simulations. By varying also the plasma temperature and density profiles, we conclude that a variation of the edge safety factor alone is not sufficient to induce a transition from global to radially inhomogeneous oscillations, as was initially suggested by experimental results. This transition appears instead to be the combined result of variations in the different plasma profiles, collisionality and finite machine size effects. In conclusion, simulations also show that radially global GAM-like oscillations can be observed in all fluxes and fluctuation fields, suggesting that they are the result of a complex nonlinear process involving also finite toroidal mode numbers and not just linear global GAM eigenmodes.« less

Investigating the radial structure of axisymmetric fluctuations in the TCV tokamak with local and global gyrokinetic GENE simulations

DOE PAGES

Merlo, Gabriele; Brunner, Stephan; Huang, Zhouji; ...

2017-12-19

Axisymmetric (n=0) density fluctuations measured in the TCV tokamak are observed to possess a frequency f₀ which is either varying (radially dispersive oscillations) or a constant over a large fraction of the plasma minor radius (radially global oscillations) as reported in a companion paper [Z. Huang et al., this issue]. Given that f₀ scales with the sound speed and given the poloidal structure of density fluctuations, these oscillations were interpreted as Geodesic Acoustic Modes, even though f₀ is in fact smaller than the local linear GAM frequency f_GAM . In this work we employ the Eulerian gyrokinetic code GENE tomore » simulate TCV relevant conditions and investigate the nature properties of these oscillations, in particular their relation to the safety factor profile. Local and global simulations are carried out and a good qualitative agreement is observed between experiments and simulations. By varying also the plasma temperature and density profiles, we conclude that a variation of the edge safety factor alone is not sufficient to induce a transition from global to radially inhomogeneous oscillations, as was initially suggested by experimental results. This transition appears instead to be the combined result of variations in the different plasma profiles, collisionality and finite machine size effects. In conclusion, simulations also show that radially global GAM-like oscillations can be observed in all fluxes and fluctuation fields, suggesting that they are the result of a complex nonlinear process involving also finite toroidal mode numbers and not just linear global GAM eigenmodes.« less

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

NASA Astrophysics Data System (ADS)

Hanson, J. M.

2013-10-01

Recent DIII-D experiments have demonstrated stable operation at very low edge safety factor, q95 <~ 2 through the use of magnetic feedback to control the n = 1 resistive wall mode (RWM) 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 < 2. These results call attention to the utility of magnetic feedback in significantly extending the tokamak operational space and potentially opening a new route to economical fusion power production. Supported by the US Department of Energy under DE-FG02-04ER54761 and DE-FC02-04ER54698.

Super-resolved terahertz microscopy by knife-edge scan

NASA Astrophysics Data System (ADS)

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.

Determination of Slope Safety Factor with Analytical Solution and Searching Critical Slip Surface with Genetic-Traversal Random Method

PubMed Central

2014-01-01

In the current practice, to determine the safety factor of a slope with two-dimensional circular potential failure surface, one of the searching methods for the critical slip surface is Genetic Algorithm (GA), while the method to calculate the slope safety factor is Fellenius' slices method. However GA needs to be validated with more numeric tests, while Fellenius' slices method is just an approximate method like finite element method. This paper proposed a new method to determine the minimum slope safety factor which is the determination of slope safety factor with analytical solution and searching critical slip surface with Genetic-Traversal Random Method. The analytical solution is more accurate than Fellenius' slices method. The Genetic-Traversal Random Method uses random pick to utilize mutation. A computer automatic search program is developed for the Genetic-Traversal Random Method. After comparison with other methods like slope/w software, results indicate that the Genetic-Traversal Random Search Method can give very low safety factor which is about half of the other methods. However the obtained minimum safety factor with Genetic-Traversal Random Search Method is very close to the lower bound solutions of slope safety factor given by the Ansys software. PMID:24782679

Plant biodiversity in French Mediterranean vineyards

NASA Astrophysics Data System (ADS)

Cohen, Marianne; Bilodeau, Clelia; Alexandre, Frédéric; Godron, Michel; Gresillon, Etienne

2017-04-01

In a context of agricultural intensification and increasing urbanization, the biodiversity of farmed plots is a key to improve the sustainability of farmed landscapes. The medium life-duration of the vineyards as well as their location in Mediterranean region are favorable to plant biodiversity. We studied 35 vineyards and if present, their edges, located in three French Mediterranean terroirs: Bandol, Pic Saint Loup and Terrasses du Larzac. We collected botanical information (floral richness et diversity, biological traits), and analyzed their relationships with different factors: social (management, heritage or professional concern), environmental (slope, exposition, geology), spatial (edges, surrounding landscape in a 500 meters radius, distance to the nearest large city). Vineyards are generally heavily disturbed by intensive practices like tilling and application of herbicides, and for this reason their floral diversity is low. This is particularly true in Bandol terroir, in accordance with the standards of the Bandol PDO wine sector. Farmed landscapes and proximity to a large town impact on functional groups, generalist species being overrepresented. If vineyards are surrounded with natural edges, it doubles the floral richness at the plot and edges scale. Species present in vineyards edges are perennial herbaceous species with Euro- Asian and Mediterranean distribution ranges characteristic of prairie and wasteland stages, increasing the functional diversity of vineyards (generalist species). Environmental factors have a lower influence: vineyards are generally located on flat lands. These results suggest that some practices should be encouraged to avoid the biological degradation of vineyards: conservation of tree-lined edges and their extensive management, reduction of chemical weeding, grass-growing using non-cosmopolitan species. These recommendations should also contribute to soil conservation.

The contact mechanics and occurrence of edge loading in modular metal-on-polyethylene total hip replacement during daily activities.

PubMed

Hua, Xijin; Li, Junyan; Jin, Zhongmin; Fisher, John

2016-06-01

The occurrence of edge loading in hip joint replacement has been associated with many factors such as prosthetic design, component malposition and activities of daily living. The present study aimed to quantify the occurrence of edge loading/contact at the articulating surface and to evaluate the effect of cup angles and edge loading on the contact mechanics of a modular metal-on-polyethylene (MoP) total hip replacement (THR) during different daily activities. A three-dimensional finite element model was developed based on a modular MoP bearing system. Different cup inclination and anteversion angles were modelled and six daily activities were considered. The results showed that edge loading was predicted during normal walking, ascending and descending stairs activities under steep cup inclination conditions (≥55°) while no edge loading was observed during standing up, sitting down and knee bending activities. The duration of edge loading increased with increased cup inclination angles and was affected by the cup anteversion angles. Edge loading caused elevated contact pressure at the articulating surface and substantially increased equivalent plastic strain of the polyethylene liner. The present study suggested that correct positioning the component to avoid edge loading that may occur during daily activities is important for MoP THR in clinical practice. Copyright © 2016. Published by Elsevier Ltd.

Effect of the Road Environment on Road Safety in Poland

NASA Astrophysics Data System (ADS)

Budzynski, Marcin; Jamroz, Kazimierz; Antoniuk, Marcin

2017-10-01

Run-off-road accidents tend to be very severe because when a vehicle leaves the road, it will often crash into a solid obstacle (tree, pole, supports, front wall of a culvert, barrier). A statistical analysis of the data shows that Poland’s main roadside hazard is trees and the severity of vehicles striking a tree in a run-off-road crash. The risks are particularly high in north-west Poland with many of the roads lined up with trees. Because of the existing rural road cross-sections, i.e. having trees directly on road edge followed immediately by drainage ditches, vulnerable road users are prevented from using shoulders and made to use the roadway. With no legal definition of the road safety zone in Polish regulations, attempts to remove roadside trees lead to major conflicts with environmental stakeholders. This is why a compromise should be sought between the safety of road users and protection of the natural environment and the aesthetics of the road experience. Rather than just cut the trees, other road safety measures should be used where possible to treat the hazardous spots by securing trees and obstacles and through speed management. Accidents that are directly related to the road environment fall into the following categories: hitting a tree, hitting a barrier, hitting a utility pole or sign, vehicle rollover on the shoulder, vehicle rollover on slopes or in ditch. The main consequence of a roadside hazard is not the likelihood of an accident itself but of its severity. Poland’s roadside accident severity is primarily the result of poor design or operation of road infrastructure. This comes as a consequence of a lack of regulations or poorly defined regulations and failure to comply with road safety standards. The new analytical model was designed as a combination of the different factors and one that will serve as a comprehensive model. It was assumed that it will describe the effect of the roadside on the number of accidents and their consequences. The design of the model was based on recommendations from analysing other models. The assumptions were the following: the model will be used to calculate risk factors and accident severity, the indicators will depend on number of vehicle kilometres travelled or traffic volumes, analyses will be based on accident data: striking a tree, hitting a barrier, hitting a utility pole or sign. Additional data will include roadside information and casualty density measures will be used - killed and injured.

The Ultimate Factor of Safety for Aircraft and Spacecraft Its History, Applications and Misconceptions

NASA Technical Reports Server (NTRS)

Zipay, John J.; Modlin, C. Thomas, Jr.; Larsen, Curtis E.

2016-01-01

The ultimate factor of safety (FOSULT) concept used in aircraft and spacecraft has evolved over many decades. Currently an FOSULT 1.5 is the FAR-mandated value for aircraft while an FOSULT of 1.4 has been used in various spacecraft. This paper was motivated by the desire to concisely explain the origins, proper interpretation and application of the ultimate factor of safety concept, since the authors have seen throughout their careers many misconceptions and incorrect applications of this concept. The history of the ultimate factor of safety concept is briefly summarized, the proper application of the factor of safety in aircraft design, structural analysis and operations is covered in detail, examples of limit load exceedance in aircraft and spacecraft are discussed, the evolution of the 1.4 FOSULT for spacecraft is described and some misconceptions regarding the ultimate factor of safety concept are addressed. It is hoped that this paper can be a summary resource for engineers to understand the origin, purpose and proper application of the ultimate factor of safety.

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

PubMed

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.

Window-closing safety system

DOEpatents

McEwan, Thomas E.

1997-01-01

A safety device includes a wire loop embedded in the glass of a passenger car window and routed near the closing leading-edge of the window. The wire loop carries microwave pulses around the loop to and from a transceiver with separate output and input ports. An evanescent field only and inch or two in radius is created along the wire loop by the pulses. Just about any object coming within the evanescent field will dramatically reduce the energy of the microwave pulses received back by the transceiver. Such a loss in energy is interpreted as a closing area blockage, and electrical interlocks are provided to halt or reverse a power window motor that is actively trying to close the window.

Window-closing safety system

DOEpatents

McEwan, T.E.

1997-08-26

A safety device includes a wire loop embedded in the glass of a passenger car window and routed near the closing leading-edge of the window. The wire loop carries microwave pulses around the loop to and from a transceiver with separate output and input ports. An evanescent field only an inch or two in radius is created along the wire loop by the pulses. Just about any object coming within the evanescent field will dramatically reduce the energy of the microwave pulses received back by the transceiver. Such a loss in energy is interpreted as a closing area blockage, and electrical interlocks are provided to halt or reverse a power window motor that is actively trying to close the window. 5 figs.

SLAC All Access: Laser Labs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Minitti, Mike; Woods, Mike

2013-03-01

From supermarket checkouts to video game consoles, lasers are ubiquitous in our lives. Here at SLAC, high-power lasers are critical to the cutting-edge research conducted at the laboratory. But, despite what you might imagine, SLAC's research lasers bear little resemblance to the blasters and phasers of science fiction. In this edition of All Access we put on our safety goggles for a peek at what goes on inside some of SLAC's many laser labs. LCLS staff scientist Mike Minitti and SLAC laser safety officer Mike Woods detail how these lasers are used to study the behavior of subatomic particles, broadenmore » our understanding of cosmic rays and even unlock the mysteries of photosynthesis.« less

Development and initial validation of an Aviation Safety Climate Scale.

PubMed

Evans, Bronwyn; Glendon, A Ian; Creed, Peter A

2007-01-01

A need was identified for a consistent set of safety climate factors to provide a basis for aviation industry benchmarking. Six broad safety climate themes were identified from the literature and consultations with industry safety experts. Items representing each of the themes were prepared and administered to 940 Australian commercial pilots. Data from half of the sample (N=468) were used in an exploratory factor analysis that produced a 3-factor model of Management commitment and communication, Safety training and equipment, and Maintenance. A confirmatory factor analysis on the remaining half of the sample showed the 3-factor model to be an adequate fit to the data. The results of this study have produced a scale of safety climate for aviation that is both reliable and valid. This study developed a tool to assess the level of perceived safety climate, specifically of pilots, but may also, with minor modifications, be used to assess other groups' perceptions of safety climate.

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

PubMed

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.

Safety assessment in the urban park environment in Alborz Province, Iran.

PubMed

Oostakhan, Morteza; Babaei, Aliakbar

2013-01-01

Urban parks, as one of the recreational and sports sectors, could cause serious injuries among different ages if the safety issues in their design are not considered. These injuries can result from the equipment in the park, including play and sports equipment, or even from environmental factors, too. Lack of safety benchmark in parks will impact on the development of future proposals. In this article, attempts are made to survey the important safety factors in the urban parks including playgrounds, fitness equipment, pedestrian surface and environmental factors into a risk assessment. Hence, a checklist of safety factors was used. A Yes or No descriptor was allocated to any factor for determining safety level. The study also suggests recommendations for future planning concerning existing failures for designers. It was found that the safety level of the regional and local parks differ from each other.

Habitat edges affect patterns of artificial nest predation along a wetland-meadow boundary

NASA Astrophysics Data System (ADS)

Suvorov, Petr; Svobodová, Jana; Albrecht, Tomáš

2014-08-01

Wetland habitats are among the most endangered ecosystems in the world. However, little is known about factors affecting the nesting success of birds in pristine grass-dominated wetlands. During three breeding periods we conducted an experiment with artificial ground nests to test two basic mechanisms (the matrix and ecotonal effects) that may result in edge effects on nest predation in grass-dominated wetland habitats. Whereas the matrix effect model supposes that predator penetrate from habitat of higher predator density to habitat of lower predator density, thus causing an edge effect in the latter, according to the ecotonal effect model predators preferentially use edge habitats over habitat interiors. In addition, we tested the edge effect in a wetland habitat using artificial shrub nests that simulated the real nests of small open-cup nesting passerines. In our study area, the lowest predation rates on ground nests were found in wetland interiors and were substantially higher along the edges of both wetland and meadow habitat. However, predation was not significantly different between meadow and wetland interiors, indicating that both mechanisms can be responsible for the edge effect in wetland edges. An increased predation rate along wetland edges was also observed for shrub nests, and resembled the predation pattern of real shrub nests in the same study area. Though we are not able to distinguish between the two mechanisms of the edge effect found, our results demonstrate that species nesting in wetland edges bordering arable land may be exposed to higher predation. Therefore, an increase in the size of wetland patches that would lead to a reduced proportion of edge areas might be a suitable management practice to protect wetland bird species in cultural European landscapes.

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

NASA Astrophysics Data System (ADS)

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.

X-ray Absorption and Emission Spectroscopy of CrIII (Hydr)Oxides: Analysis of the K-Pre-Edge Region

NASA Astrophysics Data System (ADS)

Frommer, Jakob; Nachtegaal, Maarten; Czekaj, Izabela; Weng, Tsu-Chien; Kretzschmar, Ruben

2009-10-01

Pre-edge spectral features below the main X-ray absorption K-edge of transition metals show a pronounced chemical sensitivity and are promising sources of structural information. Nevertheless, the use of pre-edge analysis in applied research is limited because of the lack of definite theoretical peak-assignments. The aim of this study was to determine the factors affecting the chromium K-pre-edge features in trivalent chromium-bearing oxides and oxyhydroxides. The selected phases varied in the degree of octahedral polymerization and the degree of iron-for-chromium substitution in the crystal structure. We investigated the pre-edge fine structure by means of high-energy-resolution fluorescence detected X-ray absorption spectroscopy and by 1s2p resonant X-ray emission spectroscopy. Multiplet theory and full multiple-scattering calculations were used to analyze the experimental data. We show that the chromium K-pre-edge contains localized and nonlocalized transitions. Contributions arising from nonlocalized metal-metal transitions are sensitive to the nearest metal type and to the linkage mode between neighboring metal octahedra. Analyzing these transitions opens up new opportunities for investigating the local coordination environment of chromium in poorly ordered solids of environmental relevance.

Enhanced Component Performance Study: Emergency Diesel Generators 1998–2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schroeder, John Alton

2015-11-01

This report presents an enhanced performance evaluation of emergency diesel generators (EDGs) at U.S. commercial nuclear power plants. This report evaluates component performance over time using (1) Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES) data from 1998 through 2014 and (2) maintenance unavailability (UA) performance data from Mitigating Systems Performance Index (MSPI) Basis Document data from 2002 through 2014. The objective is to show estimates of current failure probabilities and rates related to EDGs, trend these data on an annual basis, determine if the current data are consistent with the probability distributions currently recommended for use inmore » NRC probabilistic risk assessments, show how the reliability data differ for different EDG manufacturers and for EDGs with different ratings; and summarize the subcomponents, causes, detection methods, and recovery associated with each EDG failure mode. Engineering analyses were performed with respect to time period and failure mode without regard to the actual number of EDGs at each plant. The factors analyzed are: sub-component, failure cause, detection method, recovery, manufacturer, and EDG rating. Six trends with varying degrees of statistical significance were identified in the data.« less

In-flight edge response measurements for high-spatial-resolution remote sensing systems

NASA Astrophysics Data System (ADS)

Blonski, Slawomir; Pagnutti, Mary A.; Ryan, Robert; Zanoni, Vickie

2002-09-01

In-flight measurements of spatial resolution were conducted as part of the NASA Scientific Data Purchase Verification and Validation process. Characterization included remote sensing image products with ground sample distance of 1 meter or less, such as those acquired with the panchromatic imager onboard the IKONOS satellite and the airborne ADAR System 5500 multispectral instrument. Final image products were used to evaluate the effects of both the image acquisition system and image post-processing. Spatial resolution was characterized by full width at half maximum of an edge-response-derived line spread function. The edge responses were analyzed using the tilted-edge technique that overcomes the spatial sampling limitations of the digital imaging systems. As an enhancement to existing algorithms, the slope of the edge response and the orientation of the edge target were determined by a single computational process. Adjacent black and white square panels, either painted on a flat surface or deployed as tarps, formed the ground-based edge targets used in the tests. Orientation of the deployable tarps was optimized beforehand, based on simulations of the imaging system. The effects of such factors as acquisition geometry, temporal variability, Modulation Transfer Function compensation, and ground sample distance on spatial resolution were investigated.

School and Community Factors Involved in Chilean Students' Perception of School Safety

ERIC Educational Resources Information Center

López, Verónica; Torres-Vallejos, Javier; Villalobos-Parada, Boris; Gilreath, Tamika D.; Ascorra, Paula; Bilbao, Marian; Morales, Macarena; Carrasco, Claudia

2017-01-01

Identifying and understanding predictors of school safety perceptions is important due to its consequences for students. However, it is not clear what school-related factors most contribute to explaining students' perception of school safety, and how they relate to community-related factors such as neighborhood safety. The purpose of this study…

Leaving patients to their own devices? Smart technology, safety and therapeutic relationships.

PubMed

Ho, Anita; Quick, Oliver

2018-03-06

This debate article explores how smart technologies may create a double-edged sword for patient safety and effective therapeutic relationships. Increasing utilization of health monitoring devices by patients will likely become an important aspect of self-care and preventive medicine. It may also help to enhance accurate symptom reports, diagnoses, and prompt referral to specialist care where appropriate. However, the development, marketing, and use of such technology raise significant ethical implications for therapeutic relationships and patient safety. Drawing on lessons learned from other direct-to-consumer health products such as genetic testing, this article explores how smart technology can also pose regulatory challenges and encourage overutilization of healthcare services. In order for smart technology to promote safer care and effective therapeutic encounters, the technology and its utilization must be safe. This article argues for unified regulatory guidelines and better education for both healthcare providers and patients regarding the benefits and risks of these devices.

Nuclear reactor safety device

DOEpatents

Hutter, Ernest

1986-01-01

A safety device is disclosed for use in a nuclear reactor for axially repositioning a control rod with respect to the reactor core in the event of an upward thermal excursion. Such safety device comprises a laminated helical ribbon configured as a tube-like helical coil having contiguous helical turns with slidably abutting edges. The helical coil is disclosed as a portion of a drive member connected axially to the control rod. The laminated ribbon is formed of outer and inner laminae. The material of the outer lamina has a greater thermal coefficient of expansion than the material of the inner lamina. In the event of an upward thermal excursion, the laminated helical coil curls inwardly to a smaller diameter. Such inward curling causes the total length of the helical coil to increase by a substantial increment, so that the control rod is axially repositioned by a corresponding amount to reduce the power output of the reactor.

Use of a safety climate questionnaire in UK health care: factor structure, reliability and usability.

PubMed

Hutchinson, A; Cooper, K L; Dean, J E; McIntosh, A; Patterson, M; Stride, C B; Laurence, B E; Smith, C M

2006-10-01

To explore the factor structure, reliability, and potential usefulness of a patient safety climate questionnaire in UK health care. Four acute hospital trusts and nine primary care trusts in England. The questionnaire used was the 27 item Teamwork and Safety Climate Survey. Thirty three healthcare staff commented on the wording and relevance. The questionnaire was then sent to 3650 staff within the 13 NHS trusts, seeking to achieve at least 600 responses as the basis for the factor analysis. 1307 questionnaires were returned (36% response). Factor analyses and reliability analyses were carried out on 897 responses from staff involved in direct patient care, to explore how consistently the questions measured the underlying constructs of safety climate and teamwork. Some questionnaire items related to multiple factors or did not relate strongly to any factor. Five items were discarded. Two teamwork factors were derived from the remaining 11 teamwork items and three safety climate factors were derived from the remaining 11 safety items. Internal consistency reliabilities were satisfactory to good (Cronbach's alpha > or =0.69 for all five factors). This is one of the few studies to undertake a detailed evaluation of a patient safety climate questionnaire in UK health care and possibly the first to do so in primary as well as secondary care. The results indicate that a 22 item version of this safety climate questionnaire is useable as a research instrument in both settings, but also demonstrates a more general need for thorough validation of safety climate questionnaires before widespread usage.

Profiling contextual factors which influence safety in heavy vehicle industries.

PubMed

Edwards, Jason R D; Davey, Jeremy; Armstrong, Kerry A

2014-12-01

A significant proportion of worker fatalities within Australia result from truck-related incidents. Truck drivers face a number of health and safety concerns. Safety culture, viewed here as the beliefs, attitudes and values shared by an organisation's workers, which interact with their surrounding context to influence behaviour, may provide a valuable lens for exploring safety-related behaviours in heavy vehicle operations. To date no major research has examined safety culture within heavy vehicle industries. As safety culture provides a means to interpret experiences and generate behaviour, safety culture research should be conducted with an awareness of the context surrounding safety. The current research sought to examine previous health and safety research regarding heavy vehicle operations to profile contextual factors which influence health and safety. A review of 104 peer-reviewed papers was conducted. Findings of these papers were then thematically analysed. A number of behaviours and scenarios linked with crashes and non-crash injuries were identified, along with a selection of health outcomes. Contextual factors which were found to influence these outcomes were explored. These factors were found to originate from government departments, transport organisations, customers and the road and work environment. The identified factors may provide points of interaction, whereby culture may influence health and safety outcomes. Copyright © 2014. Published by Elsevier Ltd.

Fundamentals of Aeronautical and Aerospace Medical Science,

DTIC Science & Technology

1981-07-17

internal air bubbles and gas embol - isms can appear; over 18 kilometers it is necessary to use a pressure suit to maintain life safety. 10. Airtight...examinations have expanded this to fractures , muscle and skin injuries, blood spots, muscle tension and weakness, heart and intracranial hemorrhaging...vertebra inclines forward and when the front edge of the vertebra is subjected to a concentration of negative overweightness, fractures occur. If the

Wireless Laser Range Finder System for Vertical Displacement Monitoring of Mega-Trusses during Construction

PubMed Central

Park, Hyo Seon; Son, Sewook; Choi, Se Woon; Kim, Yousok

2013-01-01

As buildings become increasingly complex, construction monitoring using various sensors is urgently needed for both more systematic and accurate safety management and high-quality productivity in construction. In this study, a monitoring system that is composed of a laser displacement sensor (LDS) and a wireless sensor node was proposed and applied to an irregular building under construction. The subject building consists of large cross-sectional members, such as mega-columns, mega-trusses, and edge truss, which secured the large spaces. The mega-trusses and edge truss that support this large space are of the cantilever type. The vertical displacement occurring at the free end of these members was directly measured using an LDS. To validate the accuracy and reliability of the deflection data measured from the LDS, a total station was also employed as a sensor for comparison with the LDS. In addition, the numerical simulation result was compared with the deflection obtained from the LDS and total station. Based on these investigations, the proposed wireless displacement monitoring system was able to improve the construction quality by monitoring the real-time behavior of the structure, and the applicability of the proposed system to buildings under construction for the evaluation of structural safety was confirmed. PMID:23648650

2009 Human Factors and Roadway Safety Workshop : Overviews of Safety Initiatives in Iowa [SD .WMV (720x480/29fps/80.2 MB)

DOT National Transportation Integrated Search

2009-11-05

Iowa Department of Transportation Research and Technology Bureau video presentation from the 2009 human factors and roadway safety workshop session titled: Overview of Safety Initiatives in Iowa : Tom Welch, Iowa DOT Highway Division Safety Engineer,...

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

NASA Astrophysics Data System (ADS)

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.

Hidden edge Dirac point and robust quantum edge transport in InAs/GaSb quantum wells

NASA Astrophysics Data System (ADS)

Li, Chang-An; Zhang, Song-Bo; Shen, Shun-Qing

2018-01-01

The robustness of quantum edge transport in InAs/GaSb quantum wells in the presence of magnetic fields raises an issue on the fate of topological phases of matter under time-reversal symmetry breaking. A peculiar band structure evolution in InAs/GaSb quantum wells is revealed: the electron subbands cross the heavy hole subbands but anticross the light hole subbands. The topologically protected band crossing point (Dirac point) of the helical edge states is pulled to be close to and even buried in the bulk valence bands when the system is in a deeply inverted regime, which is attributed to the existence of the light hole subbands. A sizable Zeeman energy gap verified by the effective g factors of edge states opens at the Dirac point by an in-plane or perpendicular magnetic field; however, it can also be hidden in the bulk valance bands. This provides a plausible explanation for the recent observation on the robustness of quantum edge transport in InAs/GaSb quantum wells subjected to strong magnetic fields.

Bayesian prestack seismic inversion with a self-adaptive Huber-Markov random-field edge protection scheme

NASA Astrophysics Data System (ADS)

Tian, Yu-Kun; Zhou, Hui; Chen, Han-Ming; Zou, Ya-Ming; Guan, Shou-Jun

2013-12-01

Seismic inversion is a highly ill-posed problem, due to many factors such as the limited seismic frequency bandwidth and inappropriate forward modeling. To obtain a unique solution, some smoothing constraints, e.g., the Tikhonov regularization are usually applied. The Tikhonov method can maintain a global smooth solution, but cause a fuzzy structure edge. In this paper we use Huber-Markov random-field edge protection method in the procedure of inverting three parameters, P-velocity, S-velocity and density. The method can avoid blurring the structure edge and resist noise. For the parameter to be inverted, the Huber-Markov random-field constructs a neighborhood system, which further acts as the vertical and lateral constraints. We use a quadratic Huber edge penalty function within the layer to suppress noise and a linear one on the edges to avoid a fuzzy result. The effectiveness of our method is proved by inverting the synthetic data without and with noises. The relationship between the adopted constraints and the inversion results is analyzed as well.

Factors Influencing Implementation of OHSAS 18001 in Indian Construction Organizations: Interpretive Structural Modeling Approach

PubMed Central

Rajaprasad, Sunku Venkata Siva; Chalapathi, Pasupulati Venkata

2015-01-01

Background Construction activity has made considerable breakthroughs in the past two decades on the back of increases in development activities, government policies, and public demand. At the same time, occupational health and safety issues have become a major concern to construction organizations. The unsatisfactory safety performance of the construction industry has always been highlighted since the safety management system is neglected area and not implemented systematically in Indian construction organizations. Due to a lack of enforcement of the applicable legislation, most of the construction organizations are forced to opt for the implementation of Occupational Health Safety Assessment Series (OHSAS) 18001 to improve safety performance. Methods In order to better understand factors influencing the implementation of OHSAS 18001, an interpretive structural modeling approach has been applied and the factors have been classified using matrice d'impacts croises-multiplication appliqué a un classement (MICMAC) analysis. The study proposes the underlying theoretical framework to identify factors and to help management of Indian construction organizations to understand the interaction among factors influencing in implementation of OHSAS 18001. Results Safety culture, continual improvement, morale of employees, and safety training have been identified as dependent variables. Safety performance, sustainable construction, and conducive working environment have been identified as linkage variables. Management commitment and safety policy have been identified as the driver variables. Conclusion Management commitment has the maximum driving power and the most influential factor is safety policy, which states clearly the commitment of top management towards occupational safety and health. PMID:26929828

Predictors of Hospital Nurses' Safety Practices: Work Environment, Workload, Job Satisfaction, and Error Reporting.

PubMed

Chiang, Hui-Ying; Hsiao, Ya-Chu; Lee, Huan-Fang

Nurses' safety practices of medication administration, prevention of falls and unplanned extubations, and handover are essentials to patient safety. This study explored the prediction between such safety practices and work environment factors, workload, job satisfaction, and error-reporting culture of 1429 Taiwanese nurses. Nurses' job satisfaction, error-reporting culture, and one environmental factor of nursing quality were found to be major predictors of safety practices. The other environment factors related to professional development and participation in hospital affairs and nurses' workload had limited predictive effects on the safety practices. Increasing nurses' attention to patient safety by improving these predictors is recommended.

Percutaneous Edge-to-Edge Transcatheter Mitral Valve Repair: Current Indications and Future Perspectives.

PubMed

Pepe, Martino; De Cillis, Emanuela; Acquaviva, Tommaso; Cecere, Annagrazia; D'Alessandro, Pasquale; Giordano, Arturo; Ciccone, Marco Matteo; Bortone, Alessandro Santo

2018-06-01

Mitral regurgitation (MR) is the most prevalent valvular heart disease (VHD) and represents an important cause of heart failure. Medical therapy has a limited role in improving symptoms and does not hinder the progression of valvular disease. Surgery is the treatment of choice for severe symptomatic MR; valve repair is currently the preferred surgical approach because it reduces peri-operative mortality and ensures a good medium- to long-term survival outcome. Nevertheless, a non-negligible proportion of patients with indications for surgical correction are considered to be at prohibitive perioperative risk, mainly because of old age and multiple comorbidities. The introduction of percutaneous interventions to clinical practice has changed the natural history of this population. Percutaneous edge-to-edge transcatheter mitral valve repair (Mitraclip®, Abbott Vascular, Menlo Park, CA) is a state-of-the-art therapy for approaching MR in patients with a high surgical risk. Despite having been only recently introduced, this transvenous transfemoral percutaneous intervention has already been performed in more than 40,000 subjects worldwide, with reassuring post-operative results in terms of safety, feasibility, mortality and morbidity. Since Mitraclip® is considered to be minimally invasive, it is currently indicated in "frail" patients with severe comorbidities. We provide a critical review of the literature to clarify current indications, procedural details, patient selection criteria, and future perspectives for this innovative technique.

Graphene microsheets enter cells through spontaneous membrane penetration at edge asperities and corner sites

PubMed Central

Li, Yinfeng; Yuan, Hongyan; von dem Bussche, Annette; Creighton, Megan; Hurt, Robert H.; Kane, Agnes B.; Gao, Huajian

2013-01-01

Understanding and controlling the interaction of graphene-based materials with cell membranes is key to the development of graphene-enabled biomedical technologies and to the management of graphene health and safety issues. Very little is known about the fundamental behavior of cell membranes exposed to ultrathin 2D synthetic materials. Here we investigate the interactions of graphene and few-layer graphene (FLG) microsheets with three cell types and with model lipid bilayers by combining coarse-grained molecular dynamics (MD), all-atom MD, analytical modeling, confocal fluorescence imaging, and electron microscopic imaging. The imaging experiments show edge-first uptake and complete internalization for a range of FLG samples of 0.5- to 10-μm lateral dimension. In contrast, the simulations show large energy barriers relative to kBT for membrane penetration by model graphene or FLG microsheets of similar size. More detailed simulations resolve this paradox by showing that entry is initiated at corners or asperities that are abundant along the irregular edges of fabricated graphene materials. Local piercing by these sharp protrusions initiates membrane propagation along the extended graphene edge and thus avoids the high energy barrier calculated in simple idealized MD simulations. We propose that this mechanism allows cellular uptake of even large multilayer sheets of micrometer-scale lateral dimension, which is consistent with our multimodal bioimaging results for primary human keratinocytes, human lung epithelial cells, and murine macrophages. PMID:23840061

Validation of the group nuclear safety climate questionnaire.

PubMed

Navarro, M Felisa Latorre; Gracia Lerín, Francisco J; Tomás, Inés; Peiró Silla, José María

2013-09-01

Group safety climate is a leading indicator of safety performance in high reliability organizations. Zohar and Luria (2005) developed a Group Safety Climate scale (ZGSC) and found it to have a single factor. The ZGSC scale was used as a basis in this study with the researchers rewording almost half of the items on this scale, changing the referents from the leader to the group, and trying to validate a two-factor scale. The sample was composed of 566 employees in 50 groups from a Spanish nuclear power plant. Item analysis, reliability, correlations, aggregation indexes and CFA were performed. Results revealed that the construct was shared by each unit, and our reworded Group Safety Climate (GSC) scale showed a one-factor structure and correlated to organizational safety climate, formalized procedures, safety behavior, and time pressure. This validation of the one-factor structure of the Zohar and Luria (2005) scale could strengthen and spread this scale and measure group safety climate more effectively. Copyright © 2013 National Safety Council and Elsevier Ltd. All rights reserved.

Analysis of factors associated with traffic injury severity on rural roads in Iran.

PubMed

Kashani, Ali Tavakoli; Shariat-Mohaymany, Afshin; Ranjbari, Andishe

2012-01-01

Iran is a country with one of the highest rates of traffic crash fatality and injury, and seventy percent of these fatalities happen on rural roads. The objective of this study is to identify the significant factors influencing injury severity among drivers involved in crashes on two kinds of major rural roads in Iran: two-lane, two-way roads and freeways. According to the dataset, 213569 drivers were involved in rural road crashes in Iran, over the 3 years from 2006 to 2008. The Classification And Regression Tree method (CART) was applied for 13 independent variables, and one target variable of injury severity with 3 classes of no-injury, injury and fatality. Some of the independent variables were cause of crash, collision type, weather conditions, road surface conditions, driver's age and gender and seat belt usage. The CART model was trained by 70% of these data, and tested with the rest. It was indicated that seat belt use is the most important safety factor for two-lane, two-way rural roads, but on freeways, the importance of this variable is less. Cause of crash, also turned out to be the next most important variable. The results showed that for two-lane, two-way rural roads, "improper overtaking" and "speeding", and for rural freeways, "inattention to traffic ahead", "vehicle defect", and "movement of pedestrians, livestock and unauthorized vehicles on freeways" are the most serious causes of increasing injury severity. The analysis results revealed seat belt use, cause of crash and collision type as the most important variables influencing the injury severity of traffic crashes. To deal with these problems, intensifying police enforcement by means of mobile patrol vehicles, constructing overtaking lanes where necessary, and prohibiting the crossing of pedestrians and livestock and the driving of unauthorized vehicles on freeways are necessary. Moreover, creating a rumble strip on the two edges of roads, and paying attention to the design consistency of roads can be a helpful factor in order to prevent events such as "overturning" and improve the overall safety of freeways.

Calibration of highway safety manual work zone crash modification factors.

DOT National Transportation Integrated Search

2014-06-01

The Highway Safety Manual is the national safety manual that provides quantitative methods for analyzing highway safety. The : HSM presents crash modification factors related to work zone characteristics such as work zone duration and length. These c...

Relationship between organizational justice and organizational safety climate: do fairness perceptions influence employee safety behaviour?

PubMed

Gyekye, Seth Ayim; Haybatollahi, Mohammad

2014-01-01

This study investigated the relationships between organizational justice, organizational safety climate, job satisfaction, safety compliance and accident frequency. Ghanaian industrial workers participated in the study (N = 320). Safety climate and justice perceptions were assessed with Hayes, Parender, Smecko, et al.'s (1998) and Blader and Tyler's (2003) scales respectively. A median split was performed to dichotomize participants into 2 categories: workers with positive and workers with negative justice perceptions. Confirmatory factors analysis confirmed the 5-factor structure of the safety scale. Regression analyses and t tests indicated that workers with positive fairness perceptions had constructive perspectives regarding workplace safety, expressed greater job satisfaction, were more compliant with safety policies and registered lower accident rates. These findings provide evidence that the perceived level of fairness in an organization is closely associated with workplace safety perception and other organizational factors which are important for safety. The implications for safety research are discussed.

Aviation occupant survival factors: an empirical study of the SQ006 accident.

PubMed

Chang, Yu-Hern; Yang, Hui-Hua

2010-03-01

We present an empirical study of Singapore Airline (SIA) flight SQ006 to illustrate the critical factors that influence airplane occupant survivability. The Fuzzy Delphi Method was used to identify and rank the survival factors that may reduce injury and fatality in potentially survivable accidents. This is the first attempt by a group from both the public and private sectors in Taiwan to focus on cabin-safety issues related to survival factors. We designed a comprehensive survey based on our discussions with aviation safety experts. We next designed an array of important cabin-safety dimensions and then investigated and selected the critical survival factors for each dimension. Our findings reveal important cabin safety and survivability information that should provide a valuable reference for developing and evaluating aviation safety programs. We also believe that the results will be practical for designing cabin-safety education material for air travelers. Finally, the major contribution of this research is that it has identified 47 critical factors that influence accident survivability; therefore, it may encourage improvements that will promote more successful cabin-safety management. Copyright 2009 Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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.

Computing local edge probability in natural scenes from a population of oriented simple cells

PubMed Central

Ramachandra, Chaithanya A.; Mel, Bartlett W.

2013-01-01

A key computation in visual cortex is the extraction of object contours, where the first stage of processing is commonly attributed to V1 simple cells. The standard model of a simple cell—an oriented linear filter followed by a divisive normalization—fits a wide variety of physiological data, but is a poor performing local edge detector when applied to natural images. The brain's ability to finely discriminate edges from nonedges therefore likely depends on information encoded by local simple cell populations. To gain insight into the corresponding decoding problem, we used Bayes's rule to calculate edge probability at a given location/orientation in an image based on a surrounding filter population. Beginning with a set of ∼ 100 filters, we culled out a subset that were maximally informative about edges, and minimally correlated to allow factorization of the joint on- and off-edge likelihood functions. Key features of our approach include a new, efficient method for ground-truth edge labeling, an emphasis on achieving filter independence, including a focus on filters in the region orthogonal rather than tangential to an edge, and the use of a customized parametric model to represent the individual filter likelihood functions. The resulting population-based edge detector has zero parameters, calculates edge probability based on a sum of surrounding filter influences, is much more sharply tuned than the underlying linear filters, and effectively captures fine-scale edge structure in natural scenes. Our findings predict nonmonotonic interactions between cells in visual cortex, wherein a cell may for certain stimuli excite and for other stimuli inhibit the same neighboring cell, depending on the two cells' relative offsets in position and orientation, and their relative activation levels. PMID:24381295

Investigating ethnic minorities' perceptions of safety climate in the construction industry.

PubMed

Chan, Albert P C; Wong, Francis K W; Hon, Carol K H; Lyu, Sainan; Javed, Arshad Ali

2017-12-01

An increasing number of ethnic minorities (EMs) have been employed in the construction industry to alleviate severe labor shortages in many countries. Unfortunately, statistics show that EMs have higher fatal and non-fatal occupational injury rates than their local counterparts. However, EMs are often underrepresented in safety climate (SC) research as they are difficult to reach and gauge their perception. A positive relationship has been widely found between SC and safety performance. Understanding the safety perceptions of EMs helps to reduce injuries and improve their safety performance. Based on a sample of 320 EMs from 20 companies in the construction industry, exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were used to identify the SC factors of EMs, and validate the extracted factors, respectively. Multivariate analysis of variance was undertaken to examine mean differences in perceptions of SC by personal characteristics. Three SC factors for EMs encapsulating 16 variables were identified through EFA. The hypothesized CFA model for a three-factor structure derived from EFA showed a satisfactory goodness-of-fit, composite reliability, and construct validity. Three SC factors were identified, namely: (a) safety management commitment, safety resources, and safety communication; (b) employee's involvement and workmate's influence; and (c) perception of safety rules, procedures and risks. The perceptions of SC differed significantly by nationality, marital status, the number of family members supported, and drinking habit. This study reveals the perception of EMs toward SC. The findings highlight the areas for safety improvement and provide leading indicators for safety performance of EMs. The findings are also enlightening for countries with a number of EMs, such as the United Sates, the United Kingdom, Australia, Singapore, and the Middle East. Copyright © 2017. Published by Elsevier Ltd.

16 CFR 1105.2 - Factors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Factors. 1105.2 Section 1105.2 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS CONTRIBUTIONS TO COSTS OF PARTICIPANTS IN DEVELOPMENT OF CONSUMER PRODUCT SAFETY STANDARDS § 1105.2 Factors. The Commission...

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

DOT National Transportation Integrated Search

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...

Stress Analysis for the Critical Metal Structure of Bridge Crane

NASA Astrophysics Data System (ADS)

Ling, Zhangwei; Wang, Min; Xia, Junfang; Wang, Songhua; Guo, Xiaolian

2018-01-01

Based on the type of connection between the main girder and end beam of electrical single beam crane, the finite element analysis model of a full portal crane was established. The stress distribution of the critical structure under different loading conditions was analyzed. The results shown that the maximum Mises stress and deflection of the main girder were within the allowable range. And the connecting location between end beam web and main girder had higher stress than other region, especially at the lower edge and upper edge of the end beam web and the area near the bolt hole of upper wing panel. Therefore it is important to inspect the connection status, the stress condition and the crack situation nearing connection location during the regular inspection process to ensure the safety of the connection between the main girder and end beam.

Patient safety in surgical environments: cross-countries comparison of psychometric properties and results of the Norwegian version of the Hospital Survey on Patient Safety.

PubMed

Haugen, Arvid S; Søfteland, Eirik; Eide, Geir E; Nortvedt, Monica W; Aase, Karina; Harthug, Stig

2010-09-22

How hospital health care personnel perceive safety climate has been assessed in several countries by using the Hospital Survey on Patient Safety (HSOPS). Few studies have examined safety climate factors in surgical departments per se. This study examined the psychometric properties of a Norwegian translation of the HSOPS and also compared safety climate factors from a surgical setting to hospitals in the United States, the Netherlands and Norway. This survey included 575 surgical personnel in Haukeland University Hospital in Bergen, an 1100-bed tertiary hospital in western Norway: surgeons, operating theatre nurses, anaesthesiologists, nurse anaesthetists and ancillary personnel. Of these, 358 returned the HSOPS, resulting in a 62% response rate. We used factor analysis to examine the applicability of the HSOPS factor structure in operating theatre settings. We also performed psychometric analysis for internal consistency and construct validity. In addition, we compared the percent of average positive responds of the patient safety climate factors with results of the US HSOPS 2010 comparative data base report. The professions differed in their perception of patient safety climate, with anaesthesia personnel having the highest mean scores. Factor analysis using the original 12-factor model of the HSOPS resulted in low reliability scores (r = 0.6) for two factors: "adequate staffing" and "organizational learning and continuous improvement". For the remaining factors, reliability was ≥ 0.7. Reliability scores improved to r = 0.8 by combining the factors "organizational learning and continuous improvement" and "feedback and communication about error" into one six-item factor, supporting an 11-factor model. The inter-item correlations were found satisfactory. The psychometric properties of the questionnaire need further investigations to be regarded as reliable in surgical environments. The operating theatre personnel perceived their hospital's patient safety climate far more negatively than the health care personnel in hospitals in the United States and with perceptions more comparable to those of health care personnel in hospitals in the Netherlands. In fact, the surgical personnel in our hospital may perceive that patient safety climate is less focused in our hospital, at least compared with the results from hospitals in the United States.

Multi-field plasma sandpile model in tokamaks and applications

NASA Astrophysics Data System (ADS)

Peng, X. D.; Xu, J. Q.

2016-08-01

A multi-field sandpile model of tokamak plasmas is formulated for the first time to simulate the dynamic process with interaction between avalanche events on the fast/micro time-scale and diffusive transports on the slow/macro time-scale. The main characteristics of the model are that both particle and energy avalanches of sand grains are taken into account simultaneously. New redistribution rules of a sand-relaxing process are defined according to the transport properties of special turbulence which allows the uphill particle transport. Applying the model, we first simulate the steady-state plasma profile self-sustained by drift wave turbulences in the Ohmic discharge of a tokamak. A scaling law as f = a q0 b + c for the relation of both center-density n ( 0 ) and electron (ion) temperatures T e ( 0 ) ( T i ( 0 ) ) with the center-safety-factor q 0 is found. Then interesting work about the nonlocal transport phenomenon observed in tokamak experiments proceeds. It is found that the core electron temperature increases rapidly in response to the edge cold pulse and inversely it decreases in response to the edge heat pulse. The results show that the nonlocal response of core electron temperature depending on the amplitudes of background plasma density and temperature is more remarkable in a range of gas injection rate. Analyses indicate that the avalanche transport caused by plasma drift instabilities with thresholds is a possible physical mechanism for the nonlocal transport in tokamaks. It is believed that the model is capable of being applied to more extensive questions occurring in the transport field.

Factors influencing patient safety in Sweden: perceptions of patient safety officers in the county councils

PubMed Central

2013-01-01

Background National, regional and local activities to improve patient safety in Sweden have increased over the last decade. There are high ambitions for improved patient safety in Sweden. This study surveyed health care professionals who held key positions in their county council’s patient safety work to investigate their perceptions of the conditions for this work, factors they believe have been most important in reaching the current level of patient safety and factors they believe would be most important for achieving improved patient safety in the future. Methods The study population consisted of 218 health care professionals holding strategic positions in patient safety work in Swedish county councils. Using a questionnaire, the following topics were analysed in this study: profession/occupation; number of years involved in a designated task on patient safety issues; knowledge/overview of the county council’s patient safety work; ability to influence this work; conditions for this work; and the importance of various factors for current and future levels of patient safety. Results The response rate to the questionnaire was 79%. The conditions that had the highest number of responses in complete agreement were “patients’ involvement is important for patient safety” and “patient safety work has good support from the county council’s management”. Factors that were considered most important for achieving the current level of patient safety were root cause and risk analyses, incident reporting and the Swedish Patient Safety Law. An organizational culture that encourages reporting and avoids blame was considered most important for improved patient safety in the future, closely followed by improved communication between health care practitioners and patients. Conclusion Health care professionals with important positions in the Swedish county councils’ patient safety work believe that conditions for this work are somewhat constrained. They attribute the current levels of patient safety to a broad range of factors and believe that many different solutions can contribute to enhanced patient safety in the future, suggesting that this work must be multifactorial. PMID:23391301

The fear factor in healthcare: employee information sharing.

PubMed

Malvey, Donna; Fottler, Myron D; Sumner, Jennifer

2013-01-01

This study looks at employee information sharing among hospitals, a topic that is underresearched, underreported, and under the radar for most healthcare leaders. We initiated the research under the assumption that executives in healthcare are reluctant to share employment reference information about staff beyond the employee's name, dates of employment, and position held. We believed executives take this precaution because they fear being sued by the employee for defamation. However, not obtaining the necessary and critical information to hire a competent employee can open the potential employer up to a negligence lawsuit if it hires someone who jeopardizes the safety of patients or staff. Hence, the hiring organization faces a double-edged sword: On one side, it cannot get the critical information on a potential applicant from the previous employer due to a culture of "fear in sharing" information; on the other side, if it unwittingly hires a poor or dangerous applicant who threatens safety, it runs the risk of a negligence lawsuit for failure to ascertain information before the hire. Prior studies demonstrate that the likelihood of a successful defamation lawsuit is low and information sharing of factual incidents is unlikely to result in successful lawsuits. Why, then, are healthcare executives unwilling to provide comprehensive references when they should be aware that sustaining a culture of silence increases the potential for hiring a bad employee and seriously jeopardizes the security and safety of patients, other staff, and the public? This article's primary contribution to the literature is to offer the first nationwide study to empirically test the current levels of employee information sharing among hospitals. It is also the first study to focus exclusively on healthcare. Furthermore, this research considers factors that might influence executives in their willingness to share employee reference information. The study reveals that a culture of silence is pervasive among hospitals. Although many hospital executives are reluctant to share information, they tend to overestimate the likelihood of being sued (successfully or otherwise) by previous employees for defamation. In addition, this study shows that some hospital executives share negative information about former employees but may do so off the record.

2009 Human Factors and Roadway Safety Workshop : Opening Session [SD .WMV (720x480/29fps/546.0 MB)

DOT National Transportation Integrated Search

2009-11-05

Iowa Department of Transportation Research and Technology Bureau video presentation from the 2009 human factors and roadway safety workshop session titled: 2009 Human Factors and Roadway Safety Workshop Opening Session : Sandra Larson, director, Iowa...

14 CFR 27.303 - Factor of safety.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Factor of safety. 27.303 Section 27.303 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements General § 27.303 Factor of safety. Unless...

Low cost silicon solar arrays

NASA Technical Reports Server (NTRS)

Ravi, K. V.; Serreze, H. B.; Bates, H. E.; Morrison, A. D.; Jewett, D. N.; Ho, J. C. T.; Schwuttke, G. H.; Ciszek, T. F.; Kran, A.

1975-01-01

Continuous growth methodology for silicon solar cell ribbons deals with capillary effects, die effects, thermal effects and crystal shape effects. Emphasis centers on the shape of the meniscus at the ribbon edge as a factor contributing to ribbon quality with respect to defect densities. Structural and electrical characteristics of edge defined, film-fed grown silicon ribbons are elaborated. Ribbon crystal solar cells produce AMO efficiencies of 6 to 10%.

Experimental observations and finite element analysis of the initiation of fiber microbuckling in notched composite laminates

NASA Technical Reports Server (NTRS)

Guynn, E. Gail; Bradley, Walter L.

1989-01-01

An understanding was developed of the factors that determine the semi-circular edge-notched compressive strength and the associated failure mode(s) were identified of thermoplastic composite laminates with multidirectional stacking sequences. The experimental observations and the detailed literature review suggest at least four factors that affected the determination of the strain levels at which fiber microbuckling initiates and thus, partially control the composite's compression strength. The dependent variables studied are the compressive strength of a reduced gage section compression specimen and the compression strength of a compression specimen with two semi-circular edge notches (no opposite free edges) centered along the gage section. In this research, specimens containing two semi-circular edge notches (no opposite free edges) were loaded in compression at a relatively slow rate to provide more stable development of fiber microbuckling damage. The results indicate that the local constraints (free surfaces, supporting ply orientation, and resin-rich regions) significantly affect the strain level for the initiation of in-plane fiber microbuckling. Preliminary results at an elevated temperature, 77 C, showed the shear stress yield strength of the resin was reduced and consequently, the resistance to fiber microbuckling was also reduced. The finite element analysis of the perfectly straight fiber problem indicates that the free surface effect causes a 10 percent reduction in the critical buckling strain. However, the experimentally measured reduction for fibers with an initial fiber curvature, was 35 percent.

Safety climate and attitude as evaluation measures of organizational safety.

PubMed

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.

Critical factors and paths influencing construction workers' safety risk tolerances.

PubMed

Wang, Jiayuan; Zou, Patrick X W; Li, Penny P

2016-08-01

While workers' safety risk tolerances have been regarded as a main reason for their unsafe behaviors, little is known about why different people have different risk tolerances even when confronting the same situation. The aim of this research is to identify the critical factors and paths that influence workers' safety risk tolerance and to explore how they contribute to accident causal model from a system thinking perceptive. A number of methods were carried out to analyze the data collected through interviews and questionnaire surveys. In the first and second steps of the research, factor identification, factor ranking and factor analysis were carried out, and the results show that workers' safety risk tolerance can be influenced by four groups of factors, namely: (1) personal subjective perception; (2) work knowledge and experiences; (3) work characteristics; and (4) safety management. In the third step of the research, hypothetical influencing path model was developed and tested by using structural equation modeling (SEM). It is found that the effects of external factors (safety management and work characteristics) on risk tolerance are larger than that of internal factors (personal subjective perception and work knowledge & experiences). Specifically, safety management contributes the most to workers' safety risk tolerance through its direct effect and indirect effect; while personal subjective perception comes the second and can act as an intermedia for work characteristics. This research provides an in-depth insight of workers' unsafe behaviors by depicting the contributing factors as shown in the accident causal model developed in this research. Copyright © 2015 Elsevier Ltd. All rights reserved.

A numerical and experimental investigation of crystalline silica exposure control during tuck pointing.

PubMed

Heitbrink, William; Bennett, James

2006-07-01

National Institute for Occupational Safety and Health researchers investigated control measures for the removal of mortar between bricks, using a grinder. This task, "tuck pointing," is associated with crystalline silica exposures many times greater than the permissible exposure limit enforced by the Occupational Safety and Health Administration. Previous studies showed that local exhaust ventilation (LEV) of the grinding wheel through a shroud was often ineffective. Tuck pointing occurs on a scaffold. For practical purposes, this limits the size and power of the LEV system. Thus, the goal of this study was to develop a recommended flow rate for exposure control. Flow induced by the rotating grinding wheel, flow induced by the mortar particle stream, and particle momentum are potential control challenges. Computational fluid dynamic (CFD) simulation of the grinder, supported by some experimental measurements, showed the relative importance of these factors through varying parameters and tracking particles. In a simulation of the shroud and grinding wheel, with the wheel inserted to a cutting depth of 0.750 inch flush into the brick wall, -0.461 cubic feet per meter (0.461 into the exhaust takeoff) was induced by the rotating wheel. The more realistic situation of the wheel in a cut in the wall 1.25 inches deep (forming a trench circumferentially 0.500 inch below the wheel edge) induced an airflow of 8.24 cfm out of the shroud exhaust. Experimental measurements taken for validation were 7.3% lower than the CFD value. The trench effect disappeared when a stream of 10-mu m particles was launched from the grinding wheel edge, as the simulations with and without the trench had nearly identical induced flow rates, 10.8 cfm and 10.9 cfm. We thus interpreted the particle stream as more important than the wheel in inducing flow. This insight was possible because of the power of CFD, compared to intuition and classical boundary layer analysis. In this situation of no forced exhaust, all particles escaped through the gap between the shroud edge and the brick wall into the worker's environment. Experiments and simulations indicated that approximately 85 cfm was required for good control of silica exposure, clearly demonstrating that the exhaust rate must accomplish much more than balancing the induced flow. The simulations showed that the exhaust must create a vacuum in the shroud sufficient to bend the particle paths into the shroud. In the simulations, stopping the particle stream through collision (effectively removing or reducing the "daylight" between the wall and shroud) greatly lessened the required flow rate. This is difficult in practice because the gaps between the shroud and the brick and between bricks create escape paths.

Teaching patient safety and human factors in undergraduate nursing curricula in England: a pilot survey.

PubMed

Robson, Wayne; Clark, Debbie; Pinnock, David; White, Nick; Baxendale, Bryn

Patient safety is a key priority for all healthcare systems, and there is growing recognition for the need to educate tomorrow's nurses about the role of human factors in reducing avoidable harm to patients. A pilot survey was sent to 20 schools of nursing in England to explore the teaching of patient safety and human factors. All 13 schools that responded (65% response rate) stated that patient safety was covered in their curricula and was allocated more than 4 hours; all the classes included human factors. Only two respondents indicated their teaching to be multi-professional. Awareness of the World Health Organization's multiprofessional patient safety curriculum guide was poor. Faculties also seemed unaware that the Institute for Healthcare Improvement provides free online patient safety modules for students and that there is a global network of student patient safety chapters.

Surgical revision after percutaneous mitral valve repair by edge-to-edge device: when the strategy fails in the highest risk surgical population.

PubMed

Alozie, Anthony; Westphal, Bernd; Kische, Stephan; Kaminski, Alexander; Paranskaya, Liliya; Bozdag-Turan, Ilkay; Ortak, Jasmin; Schubert, Jochen; Steinhoff, Gustav; Ince, Hüseyin

2014-07-01

Percutaneous edge-to-edge devices for non-surgical repair of mitral valve regurgitation are under clinical evaluation in high-risk patients deemed not suitable for conventional surgery. To address guidelines for initial therapy decision, we here report on 13 cases of surgery after failed percutaneous edge-to-edge mitral valve repair or attempted repair, and discuss methodology and prognostic factors for operative outcome in this high-risk situation. Thirteen patients referred to our cardiothoracic unit after failed percutaneous mitral valve repair or attempted repair using the edge-to-edge technique, were treated surgically for mitral valve failure between June 2010 and December 2012. Pathology of mitral valve before and after interventional mitral valve repair (especially prevalent mode of failure) was evaluated and classified for each individual patient by echocardiography and intraoperative direct visualization. Number of implanted edge-to-edge devices were identified. Preoperative risk scores were matched with intraoperative observations and histopathological findings of valve tissue. Postoperative morbidity and mortality were analysed with respect to mitral valve and patient-related data. Three of 10 patients were referred with severe mitral valve regurgitation/stenosis after initially successful percutaneous edge-to-edge therapy or attempted therapy. In 3 patients, ≥ 2 edge-to-edge devices were implanted leading to very tight edge-to-edge leaflet connection and fibrosis. All patients underwent successful surgical mitral valve replacement and concomitant complete cardiac surgery (CABG, aortic or tricuspid valve surgery, ASD closure and pulmonary vein isolation for atrial fibrillation). The likelihood of repair was reduced with respect to multiple edge-to-edge technology. One device could not be harvested surgically because of embolization. One patient died on the second postoperative day due to sepsis with multiple organ failure. The remaining 12 patients were discharged with excellent valve prosthesis function and followed up to 2 years post-surgery. The current long-term survival rate is 77%. Our series demonstrate that highest risk patients can survive mitral valve surgery after failed multiple edge-to-edge interventional mitral valve repair. As long-term results of the MitraClip therapy are pending, we recommend close meshed follow-up of patients treated with the MitraClip device, especially within the first year of the index procedure as delays in salvage management, interventional or surgical, when the index procedure fails may increase morbidity and mortality. © The Author 2013. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Quasi-Static Probabilistic Structural Analyses Process and Criteria

NASA Technical Reports Server (NTRS)

Goldberg, B.; Verderaime, V.

1999-01-01

Current deterministic structural methods are easily applied to substructures and components, and analysts have built great design insights and confidence in them over the years. However, deterministic methods cannot support systems risk analyses, and it was recently reported that deterministic treatment of statistical data is inconsistent with error propagation laws that can result in unevenly conservative structural predictions. Assuming non-nal distributions and using statistical data formats throughout prevailing stress deterministic processes lead to a safety factor in statistical format, which integrated into the safety index, provides a safety factor and first order reliability relationship. The embedded safety factor in the safety index expression allows a historically based risk to be determined and verified over a variety of quasi-static metallic substructures consistent with the traditional safety factor methods and NASA Std. 5001 criteria.

Fracture study of windshield glass panes

NASA Technical Reports Server (NTRS)

Yeh, H. Y.

1987-01-01

The major stresses which cause crack propagation in windshield glass panes are induced by bending moments which result from the pressure differentials across the panes. Hence the stress intensity factors for the finite plate with the semi-elliptical surface flaw and edge crack under the bending moments are examined. The results show that the crack growth will be upperbound if it is computed by using the stress intensity factor for the finite plate with the edge crack subjected to pure bending moments. Furthermore, if the ratio of crack depth to plate thickness, a/t, is within 0.3, the stress intensity factor can be conservatively assumed to be constant at the value of a/t equal to zero. A simplified equation to predict the structural life of glass panes is derived based on constant stress intensity factor. The accuracy of structural life is mainly dependent on how close the empirical parameter, m, can be estimated.

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

PubMed

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

2016-01-01

Edge effects are pervasive in landscapes yet their causal mechanisms are still poorly understood. Traditionally, edge effects have been attributed to differences in habitat quality along the edge-interior gradient of habitat patches, under the assumption that no edge effects would occur if habitat quality was uniform. This assumption was questioned recently after the recognition that geometric constraints tend to reduce population abundances near the edges of habitat patches, the so-called geometric edge effect (GEE). Here, we present the first empirical, landscape-level evaluation of the importance of the GEE in shaping abundance patterns in fragmented landscapes. Using a data set on the distribution of small mammals across 18 forest fragments, we assessed whether the incorporation of the GEE into the analysis changes the interpretation of edge effects and the degree to which predictions based on the GEE match observed responses. Quantitative predictions were generated for each fragment using simulations that took into account home range, density and matrix use for each species. The incorporation of the GEE into the analysis changed substantially the interpretation of overall observed edge responses at the landscape scale. Observed abundances alone would lead to the conclusion that the small mammals as a group have no consistent preference for forest edges or interiors and that the black-eared opossum Didelphis aurita (a numerically dominant species in the community) has on average a preference for forest interiors. In contrast, incorporation of the GEE suggested that the small mammal community as a whole has a preference for forest edges, whereas D. aurita has no preference for forest edges or interiors. Unexplained variance in edge responses was reduced by the incorporation of GEE, but remained large, varying greatly on a fragment-by-fragment basis. This study demonstrates how to model and incorporate the GEE in analyses of edge effects and that this 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.

Analysis on Dangerous Source of Large Safety Accident in Storage Tank Area

NASA Astrophysics Data System (ADS)

Wang, Tong; Li, Ying; Xie, Tiansheng; Liu, Yu; Zhu, Xueyuan

2018-01-01

The difference between a large safety accident and a general accident is that the consequences of a large safety accident are particularly serious. To study the tank area which factors directly or indirectly lead to the occurrence of large-sized safety accidents. According to the three kinds of hazard source theory and the consequence cause analysis of the super safety accident, this paper analyzes the dangerous source of the super safety accident in the tank area from four aspects, such as energy source, large-sized safety accident reason, management missing, environmental impact Based on the analysis of three kinds of hazard sources and environmental analysis to derive the main risk factors and the AHP evaluation model is established, and after rigorous and scientific calculation, the weights of the related factors in four kinds of risk factors and each type of risk factors are obtained. The result of analytic hierarchy process shows that management reasons is the most important one, and then the environmental factors and the direct cause and Energy source. It should be noted that although the direct cause is relatively low overall importance, the direct cause of Failure of emergency measures and Failure of prevention and control facilities in greater weight.

2009 Human Factors and Roadway Safety Workshop : National Perspectives on Safety [SD .WMV (720x480/29fps/227.0 MB)

DOT National Transportation Integrated Search

2009-11-05

Iowa Department of Transportation Research and Technology Bureau video presentation from the 2009 human factors and roadway safety workshop session titled: National Perspectives on Safety : Essie Wagner, program analyst, National Highway Traffic Safe...

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

PubMed

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.

Factors governing hole expansion ratio of steel sheets with smooth sheared edge

NASA Astrophysics Data System (ADS)

Yoon, Jae Ik; Jung, Jaimyun; Lee, Hak Hyeon; Kim, Gyo-Sung; Kim, Hyoung Seop

2016-11-01

Stretch-flangeability measured using hole expansion test (HET) represents the ability of a material to form into a complex shaped component. Despite its importance in automotive applications of advanced high strength steels, stretch-flangeability is a less known sheet metal forming property. In this paper, we investigate the factors governing hole expansion ratio (HER) by means of tensile test and HET. We correlate a wide range of tensile properties with HERs of steel sheet specimens because the stress state in the hole edge region during the HET is almost the same as that of the uniaxial tensile test. In order to evaluate an intrinsic HER of steel sheet specimens, the initial hole of the HET specimen is produced using a milling process after punching, which can remove accumulated shearing damage and micro-void in the hole edge region that is present when using the standard HER evaluation method. It was found that the intrinsic HER of steel sheet specimens was proportional to the strain rate sensitivity exponent and post uniform elongation.

Head loss coefficient through sharp-edged orifices

NASA Astrophysics Data System (ADS)

Adam, Nicolas J.; De Cesare, Giovanni; Schleiss, Anton J.; Richard, Sylvain; Muench-Alligné, Cécile

2016-11-01

Nowadays, high-head power plants could increase their installed power capacity for many reasons, e.g. dam heightening, increase of their peak power capacity or refurbishment with new turbines. Frequently, due to several considerations, e.g. topographical or economical limitations, the existing surge tank cannot be extended to keep previous safety levels and efficiency. A valuable way to adapt these surge tanks is to place a throttle at their entrance like, for example, an orifice. The main effect of this adaptation is the introduction of head losses that reduce the extreme levels in the surge tank due to the mass oscillations resulting from a closure or opening of downstream discharge control. This research studies the influence of the edge angle of a ASME-standard orifice on the head losses. This angle introduces an asymmetrical behavior and influences head losses. Different angles are tested from 0° to the 67° (biggest angle possible for this configuration). The first step of this study is to determine experimentally the steady losses produced by orifice for several discharges. In the second step, a numerical model on ANSYS CFX is performed. Combining the two approaches, it is possible to understand and quantify the effect of the edge angle.

Modeling the Relationship between Safety Climate and Safety Performance in a Developing Construction Industry: A Cross-Cultural Validation Study

PubMed Central

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

2017-01-01

This study attempts to validate a safety performance (SP) measurement model in the cross-cultural setting of a developing country. In addition, it highlights the variations in investigating the relationship between safety climate (SC) factors and SP indicators. The data were collected from forty under-construction multi-storey building projects in Pakistan. Based on the results of exploratory factor analysis, a SP measurement model was hypothesized. It was tested and validated by conducting confirmatory factor analysis on calibration and validation sub-samples respectively. The study confirmed the significant positive impact of SC on safety compliance and safety participation, and negative impact on number of self-reported accidents/injuries. However, number of near-misses could not be retained in the final SP model because it attained a lower standardized path coefficient value. Moreover, instead of safety participation, safety compliance established a stronger impact on SP. The study uncovered safety enforcement and promotion as a novel SC factor, whereas safety rules and work practices was identified as the most neglected factor. The study contributed to the body of knowledge by unveiling the deviations in existing dimensions of SC and SP. The refined model is expected to concisely measure the SP in the Pakistani construction industry, however, caution must be exercised while generalizing the study results to other developing countries. PMID:28350366

Modeling the Relationship between Safety Climate and Safety Performance in a Developing Construction Industry: A Cross-Cultural Validation Study.

PubMed

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

2017-03-28

This study attempts to validate a safety performance (SP) measurement model in the cross-cultural setting of a developing country. In addition, it highlights the variations in investigating the relationship between safety climate (SC) factors and SP indicators. The data were collected from forty under-construction multi-storey building projects in Pakistan. Based on the results of exploratory factor analysis, a SP measurement model was hypothesized. It was tested and validated by conducting confirmatory factor analysis on calibration and validation sub-samples respectively. The study confirmed the significant positive impact of SC on safety compliance and safety participation , and negative impact on number of self-reported accidents/injuries . However, number of near-misses could not be retained in the final SP model because it attained a lower standardized path coefficient value. Moreover, instead of safety participation , safety compliance established a stronger impact on SP. The study uncovered safety enforcement and promotion as a novel SC factor, whereas safety rules and work practices was identified as the most neglected factor. The study contributed to the body of knowledge by unveiling the deviations in existing dimensions of SC and SP. The refined model is expected to concisely measure the SP in the Pakistani construction industry, however, caution must be exercised while generalizing the study results to other developing countries.

Development of an evidence-based framework of factors contributing to patient safety incidents in hospital settings: a systematic review

PubMed Central

McEachan, Rosemary R C; Giles, Sally J; Sirriyeh, Reema; Watt, Ian S; Wright, John

2012-01-01

Objective The aim of this systematic review was to develop a ‘contributory factors framework’ from a synthesis of empirical work which summarises factors contributing to patient safety incidents in hospital settings. Design A mixed-methods systematic review of the literature was conducted. Data sources Electronic databases (Medline, PsycInfo, ISI Web of knowledge, CINAHL and EMBASE), article reference lists, patient safety websites, registered study databases and author contacts. Eligibility criteria Studies were included that reported data from primary research in secondary care aiming to identify the contributory factors to error or threats to patient safety. Results 1502 potential articles were identified. 95 papers (representing 83 studies) which met the inclusion criteria were included, and 1676 contributory factors extracted. Initial coding of contributory factors by two independent reviewers resulted in 20 domains (eg, team factors, supervision and leadership). Each contributory factor was then coded by two reviewers to one of these 20 domains. The majority of studies identified active failures (errors and violations) as factors contributing to patient safety incidents. Individual factors, communication, and equipment and supplies were the other most frequently reported factors within the existing evidence base. Conclusions This review has culminated in an empirically based framework of the factors contributing to patient safety incidents. This framework has the potential to be applied across hospital settings to improve the identification and prevention of factors that cause harm to patients. PMID:22421911

Safety compliance and safety climate: A repeated cross-sectional study in the oil and gas industry.

PubMed

Kvalheim, Sverre A; Dahl, Øyvind

2016-12-01

Violations of safety rules and procedures are commonly identified as a causal factor in accidents in the oil and gas industry. Extensive knowledge on effective management practices related to improved compliance with safety procedures is therefore needed. Previous studies of the causal relationship between safety climate and safety compliance demonstrate that the propensity to act in accordance with prevailing rules and procedures is influenced to a large degree by workers' safety climate. Commonly, the climate measures employed differ from one study to another and identical measures of safety climate are seldom tested repeatedly over extended periods of time. This research gap is addressed in the present study. The study is based on a survey conducted four times among sharp-end workers of the Norwegian oil and gas industry (N=31,350). This is done by performing multiple tests (regression analysis) over a period of 7years of the causal relationship between safety climate and safety compliance. The safety climate measure employed is identical across the 7-year period. Taking all periods together, the employed safety climate model explained roughly 27% of the variance in safety compliance. The causal relationship was found to be stable across the period, thereby increasing the reliability and the predictive validity of the factor structure. The safety climate factor that had the most powerful effect on safety compliance was work pressure. The factor structure employed shows high predictive validity and should therefore be relevant to organizations seeking to improve safety in the petroleum sector. The findings should also be relevant to other high-hazard industries where safety rules and procedures constitute a central part of the approach to managing safety. Copyright © 2016 Elsevier Ltd and National Safety Council. All rights reserved.

Scientific evaluation of the safety factor for the acceptable daily intake (ADI). Case study: butylated hydroxyanisole (BHA).

PubMed

Würtzen, G

1993-01-01

The principles of 'data-derived safety factors' are applied to toxicological and biochemical information on butylated hydroxyanisole (BHA). The calculated safety factor for an ADI is, by this method, comparable to the existing internationally recognized safety evaluations. Relevance for humans of forestomach tumours in rodents is discussed. The method provides a basis for organizing data in a way that permits an explicit assessment of its relevance.

Output factor determination based on Monte Carlo simulation for small cone field in 10-MV photon beam.

PubMed

Fukata, Kyohei; Sugimoto, Satoru; Kurokawa, Chie; Saito, Akito; Inoue, Tatsuya; Sasai, Keisuke

2018-06-01

The difficulty of measuring output factor (OPF) in a small field has been frequently discussed in recent publications. This study is aimed to determine the OPF in a small field using 10-MV photon beam and stereotactic conical collimator (cone). The OPF was measured by two diode detectors (SFD, EDGE detector) and one micro-ion chamber (PinPoint 3D chamber) in a water phantom. A Monte Carlo simulation using simplified detector model was performed to obtain the correction factor for the detector measurements. About 12% OPF difference was observed in the measurement at the smallest field (7.5 mm diameter) for EDGE detector and PinPoint 3D chamber. By applying the Monte Carlo-based correction factor to the measurement, the maximum discrepancy among the three detectors was reduced to within 3%. The results indicate that determination of OPF in a small field should be carefully performed. Especially, detector choice and appropriate correction factor application are very important in this regard.

A sensitivity analysis of "Forests on the Edge: Housing Development on America's Private Forests."

Treesearch

Eric M. White; Ralph J. Alig; Lisa G. Mahal; David M. Theobald

2009-01-01

The original Forests on the Edge report (FOTE 1) indicated that 44.2 million acres of private forest land was projected to experience substantial increases in residential development in the coming decades. In this study, we examined the sensitivity of the FOTE 1 results to four factors: (1) use of updated private land and forest cover spatial data and a revised model...

Niche overlap of competing carnivores across climatic gradients and the conservation implications of climate change at geographic range margins

Treesearch

William J. Zielinski; Jody M. Tucker; Kerry M. Rennie

2017-01-01

There is considerable interest in factors controlling “warm-edge” limits – the lower elevation and latitudinal edges of a species' range. Understanding whether conservation measures can mitigate anticipated change in climate requires consideration of future climate as well as species interactions. We explored niche relations of martens and fishers at their...

Influence of a falling edge on high power microwave pulse combination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jiawei; Huang, Wenhua; Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024

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 offmore » 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.« less

Edge orientations of mechanically exfoliated anisotropic two-dimensional materials

NASA Astrophysics Data System (ADS)

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.

Influence of a falling edge on high power microwave pulse combination

NASA Astrophysics Data System (ADS)

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.

Thermal properties of composite materials : effective conductivity tensor and edge effects

NASA Astrophysics Data System (ADS)

Matine, A.; Boyard, N.; Cartraud, P.; Legrain, G.; Jarny, Y.

2012-11-01

The homogenization theory is a powerful approach to determine the effective thermal conductivity tensor of heterogeneous materials such as composites, including thermoset matrix and fibres. Once the effective properties are calculated, they can be used to solve a heat conduction problem on the composite structure at the macroscopic scale. This approach leads to good approximations of both the heat flux and temperature in the interior zone of the structure, however edge effects occur in the vicinity of the domain boundaries. In this paper, following the approach proposed in [10] for elasticity, it is shown how these edge effects can be corrected. Thus an additional asymptotic expansion is introduced, which plays the role of a edge effect term. This expansion tends to zero far from the boundary, and is assumed to decrease exponentially. Moreover, the length of the edge effect region can be determined from the solution of an eigenvalue problem. Numerical examples are considered for a standard multilayered material. The homogenized solutions computed with a finite element software, and corrected with the edge effect terms, are compared to a heterogeneous finite element solution at the microscopic scale. The influences of the thermal contrast and scale factor are illustrated for different kind of boundary conditions.

The effect of split pixel HDR image sensor technology on MTF measurements

NASA Astrophysics Data System (ADS)

Deegan, Brian M.

2014-03-01

Split-pixel HDR sensor technology is particularly advantageous in automotive applications, because the images are captured simultaneously rather than sequentially, thereby reducing motion blur. However, split pixel technology introduces artifacts in MTF measurement. To achieve a HDR image, raw images are captured from both large and small sub-pixels, and combined to make the HDR output. In some cases, a large sub-pixel is used for long exposure captures, and a small sub-pixel for short exposures, to extend the dynamic range. The relative size of the photosensitive area of the pixel (fill factor) plays a very significant role in the output MTF measurement. Given an identical scene, the MTF will be significantly different, depending on whether you use the large or small sub-pixels i.e. a smaller fill factor (e.g. in the short exposure sub-pixel) will result in higher MTF scores, but significantly greater aliasing. Simulations of split-pixel sensors revealed that, when raw images from both sub-pixels are combined, there is a significant difference in rising edge (i.e. black-to-white transition) and falling edge (white-to-black) reproduction. Experimental results showed a difference of ~50% in measured MTF50 between the falling and rising edges of a slanted edge test chart.

On the Accuracy of Probabilistic Bucking Load Prediction

NASA Technical Reports Server (NTRS)

Arbocz, Johann; Starnes, James H.; Nemeth, Michael P.

2001-01-01

The buckling strength of thin-walled stiffened or unstiffened, metallic or composite shells is of major concern in aeronautical and space applications. The difficulty to predict the behavior of axially compressed thin-walled cylindrical shells continues to worry design engineers as we enter the third millennium. Thanks to extensive research programs in the late sixties and early seventies and the contributions of many eminent scientists, it is known that buckling strength calculations are affected by the uncertainties in the definition of the parameters of the problem such as definition of loads, material properties, geometric variables, edge support conditions, and the accuracy of the engineering models and analysis tools used in the design phase. The NASA design criteria monographs from the late sixties account for these design uncertainties by the use of a lump sum safety factor. This so-called 'empirical knockdown factor gamma' usually results in overly conservative design. Recently new reliability based probabilistic design procedure for buckling critical imperfect shells have been proposed. It essentially consists of a stochastic approach which introduces an improved 'scientific knockdown factor lambda(sub a)', that is not as conservative as the traditional empirical one. In order to incorporate probabilistic methods into a High Fidelity Analysis Approach one must be able to assess the accuracy of the various steps that must be executed to complete a reliability calculation. In the present paper the effect of size of the experimental input sample on the predicted value of the scientific knockdown factor lambda(sub a) calculated by the First-Order, Second-Moment Method is investigated.

To what extent can theory account for the findings of road safety evaluation studies?

PubMed

Elvik, Rune

2004-09-01

This paper proposes a conceptual framework that can be used to assess to what extent the findings of road safety evaluation research make sense from a theoretical point of view. The effects of road safety measures are modelled as passing through two causal chains. One of these, termed the engineering effect, refers to the intended effects of a road safety measure on a set of risk factors related to accident occurrence or injury severity. The engineering effect of road safety measures is modelled in terms of nine basic risk factors, one or more of which any road safety measure needs to influence in order to have the intended effect on accidents or injuries. The other causal chain producing the effects of road safety measures is termed the behavioural effect, and refers to road user behavioural adaptations to road safety measures. The behavioural effect is related to the engineering effect, in the sense that certain properties of the engineering effect of a road safety measure influence the likelihood that behavioural adaptation will occur. The behavioural effect of a road safety measure is modelled in terms of six factors that influence the likelihood that behavioural adaptation will occur. The nine basic risk factors representing the engineering effect of a road safety measure, and the six factors influencing the likelihood of behavioural adaptation can be used as checklists in assessing whether or not the findings of road safety evaluation studies make sense from a theoretical point of view. At the current state of knowledge, a more stringent evaluation of the extent to which theory can explain the findings of road safety evaluation studies is, in most cases, not possible. Copyright 2003 Elsevier Ltd.

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

PubMed

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 <25 patients or where 1-year results were not delineated between MR aetiology were excluded. This study is registered with PROSPERO. A total of nine studies investigating the mid-term outcome of percutaneous 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%; p<0.01) and re-hospitalisation for heart failure (137/605 vs 31/220; 23% vs 14%; p=0.03). No differences were found in terms of single leaflet device attachment (25/969 vs 20/464; 3% vs 4%; p=0.81) and device embolisation (no events reported in both groups) at 1 year. This meta-analysis suggests that percutaneous edge-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.

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

PubMed

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.

Psychometrics of the AAN Caregiver Driving Safety Questionnaire and contributors to caregiver concern about driving safety in older adults.

PubMed

Carvalho, Janessa O; Springate, Beth; Bernier, Rachel A; Davis, Jennifer

2018-03-01

ABSTRACTBackground:The American Academy of Neurology (AAN) updated their practice parameters in the evaluation of driving risk in dementia and developed a Caregiver Driving Safety Questionnaire, detailed in their original manuscript (Iverson Gronseth, Reger, Classen, Dubinsky, & Rizzo, 2010). They described four factors associated with decreased driving ability in dementia patients: history of crashes or citations, informant-reported concerns, reduced mileage, and aggressive driving. An informant-reported AAN Caregiver Driving Safety Questionnaire was designed with these elements, and the current study was the first to explore the factor structure of this questionnaire. Additionally, we examined associations between these factors and cognitive and behavioral measures in patients with mild cognitive impairment or early Alzheimer's disease and their informants. Exploratory factor analysis revealed a four-component structure, consistent with the theory behind the AAN scale composition. These four factor scores also were significantly associated with performance on cognitive screening instruments and informant reported behavioral dysfunction. Regressions revealed that behavioral dysfunction predicted caregiver concerns about driving safety beyond objective patient cognitive dysfunction. In this first known quantitative exploration of the scale, our results support continued use of this scale in office driving safety assessments. Additionally, patient behavioral changes predicted caregiver concerns about driving safety over and above cognitive status, which suggests that caregivers may benefit from psychoeducation about cognitive factors that may negatively impact driving safety.

Patient safety culture in out-of-hours primary care services in the Netherlands: a cross-sectional survey.

PubMed

Smits, Marleen; Keizer, Ellen; Giesen, Paul; Deilkås, Ellen Catharina Tveter; Hofoss, Dag; Bondevik, Gunnar Tschudi

2018-03-01

To examine patient safety culture in Dutch out-of-hours primary care using the safety attitudes questionnaire (SAQ) which includes five factors: teamwork climate, safety climate, job satisfaction, perceptions of management and communication openness. Cross-sectional observational study using an anonymous web-survey. Setting Sixteen out-of-hours general practitioner (GP) cooperatives and two call centers in the Netherlands. Subjects Primary healthcare providers in out-of-hours services. Main outcome measures Mean scores on patient safety culture factors; association between patient safety culture and profession, gender, age, and working experience. Overall response rate was 43%. A total of 784 respondents were included; mainly GPs (N = 470) and triage nurses (N = 189). The healthcare providers were most positive about teamwork climate and job satisfaction, and less about communication openness and safety climate. The largest variation between clinics was found on safety climate; the lowest on teamwork climate. Triage nurses scored significantly higher than GPs on each of the five patient safety factors. Older healthcare providers scored significantly higher than younger on safety climate and perceptions of management. More working experience was positively related to higher teamwork climate and communication openness. Gender was not associated with any of the patient safety factors. Our study showed that healthcare providers perceive patient safety culture in Dutch GP cooperatives positively, but there are differences related to the respondents' profession, age and working experience. Recommendations for future studies are to examine reasons for these differences, to examine the effects of interventions to improve safety culture and to make international comparisons of safety culture. Key Points Creating a positive patient safety culture is assumed to be a prerequisite for quality and safety. We found that: • healthcare providers in Dutch GP cooperatives perceive patient safety culture positively; • triage nurses scored higher than GPs, and older and more experienced healthcare professionals scored higher than younger and less experienced professionals - on several patient safety culture factors; and • within the GP cooperatives, safety climate and openness of communication had the largest potential for improvement.

Patient safety culture in out-of-hours primary care services in the Netherlands: a cross-sectional survey

PubMed Central

Smits, Marleen; Keizer, Ellen; Giesen, Paul; Deilkås, Ellen Catharina Tveter; Hofoss, Dag; Bondevik, Gunnar Tschudi

2018-01-01

Objective To examine patient safety culture in Dutch out-of-hours primary care using the safety attitudes questionnaire (SAQ) which includes five factors: teamwork climate, safety climate, job satisfaction, perceptions of management and communication openness. Design Cross-sectional observational study using an anonymous web-survey. Setting Sixteen out-of-hours general practitioner (GP) cooperatives and two call centers in the Netherlands. Subjects Primary healthcare providers in out-of-hours services. Main outcome measures Mean scores on patient safety culture factors; association between patient safety culture and profession, gender, age, and working experience. Results Overall response rate was 43%. A total of 784 respondents were included; mainly GPs (N = 470) and triage nurses (N = 189). The healthcare providers were most positive about teamwork climate and job satisfaction, and less about communication openness and safety climate. The largest variation between clinics was found on safety climate; the lowest on teamwork climate. Triage nurses scored significantly higher than GPs on each of the five patient safety factors. Older healthcare providers scored significantly higher than younger on safety climate and perceptions of management. More working experience was positively related to higher teamwork climate and communication openness. Gender was not associated with any of the patient safety factors. Conclusions Our study showed that healthcare providers perceive patient safety culture in Dutch GP cooperatives positively, but there are differences related to the respondents’ profession, age and working experience. Recommendations for future studies are to examine reasons for these differences, to examine the effects of interventions to improve safety culture and to make international comparisons of safety culture. Key Points Creating a positive patient safety culture is assumed to be a prerequisite for quality and safety. We found that: • healthcare providers in Dutch GP cooperatives perceive patient safety culture positively; • triage nurses scored higher than GPs, and older and more experienced healthcare professionals scored higher than younger and less experienced professionals – on several patient safety culture factors; and • within the GP cooperatives, safety climate and openness of communication had the largest potential for improvement. PMID:29334826

Treatment of cutaneous leishmaniasis with thermotherapy in Brazil: an efficacy and safety study*

PubMed Central

2018-01-01

BACKGROUND Pentavalent antimonials remain as the standard drugs in the treatment of cutaneous leishmaniosis. The high cost, difficult administration, long treatment time, toxicity and increasing morbidity are factors that limit the use of these drugs. OBJECTIVES To describe the response to radiofrequency thermotherapy in the treatment of localized cutaneous leishmaniasis in Brazil, and to evaluate its safety and tolerability. METHODS We conducted a non-comparative open trial with a total of 15 patients confirmed to have cutaneous leishmaniasis on parasitological examination. A single radiofrequency thermotherapy session at 50ºC for 30 seconds was applied to the lesion and its edges. In patients with more than one lesion, only the largest one was treated initially. If after 30 days there was no evidence of healing, the smaller lesion was also treated with thermotherapy. Clinical cure was defined as visible healing for three months after treatment. The patients were followed-up for six months and there was no follow-up loss. RESULTS Of all 23 lesions, only two evolved to complete healing without the need of treatment. Of 21 lesions, 18 (85.7%) achieved full healing. The main observed side effects were itching, burning sensation, pain and blisters. STUDY LIMITATIONS Sample with a small number of patients and short follow-up. CONCLUSION Thermotherapy can be considered a therapeutic alternative in localized cutaneous leishmaniasis, especially in cases of single cutaneous lesions and with formal contraindications to conventional treatment with pentavalent antimonials. PMID:29924242

Emerging Transcatheter Options for Tricuspid Regurgitation

PubMed Central

Kalra, Ankur; Uberoi, Angad S.; Latib, Azeem; Khera, Sahil; Little, Stephen H.; Bhatt, Deepak L.; Reardon, Michael J.; Kleiman, Neal S.; Barker, Colin M.

2017-01-01

Tricuspid regurgitation (TR) presents as either primary valve pathology or secondary to pulmonary or left-sided heart disease. Severe TR portends a worse prognosis independent of age, right ventricular size and function, severe left ventricular dysfunction, and increased pulmonary arterial pressures. Surgical treatment for TR has mostly been limited to patients undergoing mitral valve repair since those at high surgical risk are not candidates for traditional TR surgery. For these patients, minimally invasive techniques could be of great benefit, yet these techniques have been slow to develop because of the various anatomic and physiological aspects of the tricuspid valve apparatus. Several promising new techniques are currently undergoing clinical investigation, including caval valve implantation, percutaneous tricuspid annuloplasty techniques (Trialign, TriCinch, Cardioband), edge-to-edge repair with the MitraClip system, the FORMA device, and the GATE tricuspid Atrioventricular Valved Stent. Further evaluation of their safety and long-term efficacy is warranted prior to commercial approval and widespread adoption. PMID:29743996

Laboratory glassware rack for seismic safety

NASA Technical Reports Server (NTRS)

Cohen, M. M. (Inventor)

1985-01-01

A rack for laboratory bottles and jars for chemicals and medicines has been designed to provide the maximum strength and security to the glassware in the event of a significant earthquake. The rack preferably is rectangular and may be made of a variety of chemically resistant materials including polypropylene, polycarbonate, and stainless steel. It comprises a first plurality of parallel vertical walls, and a second plurality of parallel vertical walls, perpendicular to the first. These intersecting vertical walls comprise a self-supporting structure without a bottom which sits on four legs. The top surface of the rack is formed by the top edges of all the vertical walls, which are not parallel but are skewed in three dimensions. These top edges form a grid matrix having a number of intersections of the vertical walls which define a number of rectangular compartments having varying widths and lengths and varying heights.

Plume RF interference calculations for space shuttle

NASA Technical Reports Server (NTRS)

Boynton, F. P.; Rajasekhar, P. S.

1978-01-01

During a static ground test of a full-scale SRM, measurements of attenuation of the UHF 416.5 MHz Range Safety Signal, the VHF voice link (230 MHz), and of S-band (c. 2.2. GHz) communications links were undertaken. Analyses of these results indicate that measurable attenuation did occur at all test frequencies. The measured attenuation levels are compared with a simple model in which the received signal is identified as that diffracted about the edge of the highly absorbing plume and the signal level in the shadow zone is evaluated using the formula for diffraction at a straight edge. The comparison is satisfactory at VHF and UHF frequencies, and slightly less so at S-band. Reasons for the discrepancies found at higher frequencies are discussed. A revised procedure which appears to relieve the accuracy problem was developed. This procedure is discussed along with applications to high altitude SRM plume attenuation.

Space station crew safety alternatives study. Volume 3: Safety impact of human factors

NASA Technical Reports Server (NTRS)

Rockoff, L. A.; Raasch, R. F.; Peercy, R. L., Jr.

1985-01-01

The first 15 years of accumulated space station concepts for Initial Operational Capability (IOC) during the early 1990's was considered. Twenty-five threats to the space station are identified and selected threats addressed as impacting safety criteria, escape and rescue, and human factors safety concerns. Of the 25 threats identified, eight are discussed including strategy options for threat control: fire, biological or toxic contamination, injury/illness, explosion, loss of pressurization, radiation, meteoroid penetration and debris. Of particular interest here is volume three (of five volumes) pertaining to the safety impact of human factors.

Time-dependent modeling of dust injection in semi-detached ITER divertor plasma

NASA Astrophysics Data System (ADS)

Smirnov, Roman; Krasheninnikov, Sergei

2017-10-01

At present, it is generally understood that dust related issues will play important role in operation of the next step fusion devices, i.e. ITER, and in the development of future fusion reactors. Recent progress in research on dust in magnetic fusion devises has outlined several topics of particular concern: a) degradation of fusion plasma performance; b) impairment of in-vessel diagnostic instruments; and c) safety issues related to dust reactivity and tritium retention. In addition, observed dust events in fusion edge plasmas are highly irregular and require consideration of temporal evolution of both the dust and the fusion plasma. In order to address the dust-related fusion performance issues, we have coupled the dust transport code DUSTT and the edge plasma transport code UEDGE in time-dependent manner, allowing modeling of transient dust-induced phenomena in fusion edge plasmas. Using the coupled codes we simulate burst-like injection of tungsten dust into ITER divertor plasma in semi-detached regime, which is considered as preferable ITER divertor operational mode based on the plasma and heat load control restrictions. Analysis of transport of the dust and the dust-produced impurities, and of dynamics of the ITER divertor and edge plasma in response to the dust injection will be presented. This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, under Award Number DE-FG02-06ER54852.

Critical safety assurance factors for manned spacecraft - A fire safety perspective

NASA Technical Reports Server (NTRS)

Rodney, George A.

1990-01-01

Safety assurance factors for manned spacecraft are discussed with a focus on the Space Station Freedom. A hazard scenario is provided to demonstrate a process commonly used by safety engineers and other analysts to identify onboard safety risks. Fire strategies are described, including a review of fire extinguishing agents being considered for the Space Station. Lessons learned about fire safety technology in other areas are also noted. NASA and industry research on fire safety applications is discussed. NASA's approach to ensuring safety for manned spacecraft is addressed in the context of its multidiscipline program.

Factors related to increasing safety belt use in states with safety belt use laws : second annual report to Congress

DOT National Transportation Integrated Search

1989-01-01

This report is the second in a series of four annual reports to the Congress on provisions of state safety belt use laws and other programmatic factors related to increasing safety belt use levels. The first Congressional Report reviewed what was kno...

Factors related to increasing safety belt use in states with safety belt use laws : second annual report to Congress, 1988.

DOT National Transportation Integrated Search

1989-01-01

This report. is the second in a series of four annual reports to the : Congress on provisions of state safety belt use laws and other : programmatic factors related to increasing safety belt use levels. : The first Congressional Report reviewed what ...

A competitive edge. Whether for profit or not, CIOs are under pressure to make sure every IT dollar yields concrete benefits.

PubMed

Hagland, Mark

2009-03-01

CIOs need to focus on IT that can be used to improve patient care and patient safety, reduce medical errors, enhance the patient experience, and improve clinician workflow and efficiency. Out of those improvements, comes ROI. Successful implementations come from CIOs and their teams working closely with clinician leaders. The concept of measuring "value" may more useful than tracking the fruits of "investment."

Aircrew Performance Cutting-Edge Technology: Emerging Human Performance Enhancement Technology Vision in Support of Operational Military Aviation Strategy

DTIC Science & Technology

2003-09-01

Refractive Surgery Origin and History, (RK, PRK , LASIK ) Refractive surgery was first considered as early as 1898 by a Dutch professor and was...34 This ejection demonstrated one extreme facet of the safety of PRK . Laser-Assisted In Situ Keratomileusis ( LASIK ) LASIK offers the greatest...refractive shift of clinical significance.35 Therefore LASIK and PRK , recipients had no significant vision changes at altitude, unlike recipients of RK

Use of adhesive surgical tape with the absorbable continuous subcuticular suture.

PubMed

Kolt, Jeremy D

2003-08-01

The absorbable continuous subcuticular suture is frequently used to close surgical incisions where the aim is healing by primary intention. A form of adhesive surgical tape is commonly also placed over the wound but this combination closure seems to have its development based on anecdotal, rather than experimental evidence. The present study reviews the scientific literature on the development of sutureless wound closure and presents the current evidence for the use of combination wound closure. Review was undertaken of the medical literature using the PubMed Internet database and cross-referencing major -articles on the subject. The following combinations of key words were searched: skin closure, wound closure, suture technique, sutureless, adhesive tape, op-site, staples, subcuticular suture, complication, infection and scars. Taped closure alone has advantages of lower wound infection rates and greater wound tensile strength, but disadvantages of epidermal reaction, skin edge inversion, doubtful safety and time required for meticulous surgical technique. The use of the continuous absorbable subcuticular suture allows accurate skin edge approximation, which increases the safety margin. The combination closure has a slightly superior cosmetic result to sutureless techniques but no study has been performed to compare the results of combination subcuticular suture and tape, with tape or subcuticular suture alone. There is no evidence in the scientific literature to justify or support the practice of closing a surgical wound with both subcuticular suture and adhesive surgical tape.

Development of a 2-stage shear-cutting-process to reduce cut-edge-sensitivity of steels

NASA Astrophysics Data System (ADS)

Gläsner, T.; Sunderkötter, C.; Hoffmann, H.; Volk, W.; Golle, R.

2017-09-01

The edge cracking sensitivity of AHSS and UHSS is a challenging factor in the cold forming process. Expanding cut holes during flanging operations is rather common in automotive components. During these flanging operations the pierced hole is stretched so that its diameter is increased. These flanging operations stretch material that has already been subjected to large amounts of plastic deformation, therefore forming problems may occur. An innovative cutting process decreases micro cracks in the cutting surface and facilitates the subsequent cold forming process. That cutting process consists of two stages, which produces close dimensional tolerance and smooth edges. As a result the hole expanding ratio was increased by nearly 100 % when using thick high strength steels for suspension components. The paper describes the mechanisms of the trimming process at the cut edge, and the positive effect of the 2-stage shear-cutting process on the hole extension capability of multiphase steels.

Charge and spin transport in edge channels of a ν=0 quantum Hall system on the surface of topological insulators.

PubMed

Morimoto, Takahiro; Furusaki, Akira; Nagaosa, Naoto

2015-04-10

Three-dimensional topological insulators of finite thickness can show the quantum Hall effect (QHE) at the filling factor ν=0 under an external magnetic field if there is a finite potential difference between the top and bottom surfaces. We calculate energy spectra of surface Weyl fermions in the ν=0 QHE and find that gapped edge states with helical spin structure are formed from Weyl fermions on the side surfaces under certain conditions. These edge channels account for the nonlocal charge transport in the ν=0 QHE which is observed in a recent experiment on (Bi_{1-x}Sb_{x})_{2}Te_{3} films. The edge channels also support spin transport due to the spin-momentum locking. We propose an experimental setup to observe various spintronics functions such as spin transport and spin conversion.

Protected Pseudohelical Edge States in Z2-Trivial Proximitized Graphene

NASA Astrophysics Data System (ADS)

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.

The Safety Attitudes Questionnaire: psychometric properties, benchmarking data, and emerging research.

PubMed

Sexton, John B; Helmreich, Robert L; Neilands, Torsten B; Rowan, Kathy; Vella, Keryn; Boyden, James; Roberts, Peter R; Thomas, Eric J

2006-04-03

There is widespread interest in measuring healthcare provider attitudes about issues relevant to patient safety (often called safety climate or safety culture). Here we report the psychometric properties, establish benchmarking data, and discuss emerging areas of research with the University of Texas Safety Attitudes Questionnaire. Six cross-sectional surveys of health care providers (n = 10,843) in 203 clinical areas (including critical care units, operating rooms, inpatient settings, and ambulatory clinics) in three countries (USA, UK, New Zealand). Multilevel factor analyses yielded results at the clinical area level and the respondent nested within clinical area level. We report scale reliability, floor/ceiling effects, item factor loadings, inter-factor correlations, and percentage of respondents who agree with each item and scale. A six factor model of provider attitudes fit to the data at both the clinical area and respondent nested within clinical area levels. The factors were: Teamwork Climate, Safety Climate, Perceptions of Management, Job Satisfaction, Working Conditions, and Stress Recognition. Scale reliability was 0.9. Provider attitudes varied greatly both within and among organizations. Results are presented to allow benchmarking among organizations and emerging research is discussed. The Safety Attitudes Questionnaire demonstrated good psychometric properties. Healthcare organizations can use the survey to measure caregiver attitudes about six patient safety-related domains, to compare themselves with other organizations, to prompt interventions to improve safety attitudes and to measure the effectiveness of these interventions.

The role of psychological factors in workplace safety.

PubMed

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.

An edge-directed interpolation method for fetal spine MR images.

PubMed

Yu, Shaode; Zhang, Rui; Wu, Shibin; Hu, Jiani; Xie, Yaoqin

2013-10-10

Fetal spinal magnetic resonance imaging (MRI) is a prenatal routine for proper assessment of fetus development, especially when suspected spinal malformations occur while ultrasound fails to provide details. Limited by hardware, fetal spine MR images suffer from its low resolution.High-resolution MR images can directly enhance readability and improve diagnosis accuracy. Image interpolation for higher resolution is required in clinical situations, while many methods fail to preserve edge structures. Edge carries heavy structural messages of objects in visual scenes for doctors to detect suspicions, classify malformations and make correct diagnosis. Effective interpolation with well-preserved edge structures is still challenging. In this paper, we propose an edge-directed interpolation (EDI) method and apply it on a group of fetal spine MR images to evaluate its feasibility and performance. This method takes edge messages from Canny edge detector to guide further pixel modification. First, low-resolution (LR) images of fetal spine are interpolated into high-resolution (HR) images with targeted factor by bi-linear method. Then edge information from LR and HR images is put into a twofold strategy to sharpen or soften edge structures. Finally a HR image with well-preserved edge structures is generated. The HR images obtained from proposed method are validated and compared with that from other four EDI methods. Performances are evaluated from six metrics, and subjective analysis of visual quality is based on regions of interest (ROI). All these five EDI methods are able to generate HR images with enriched details. From quantitative analysis of six metrics, the proposed method outperforms the other four from signal-to-noise ratio (SNR), peak signal-to-noise ratio (PSNR), structure similarity index (SSIM), feature similarity index (FSIM) and mutual information (MI) with seconds-level time consumptions (TC). Visual analysis of ROI shows that the proposed method maintains better consistency in edge structures with the original images. The proposed method classifies edge orientations into four categories and well preserves structures. It generates convincing HR images with fine details and is suitable in real-time situations. Iterative curvature-based interpolation (ICBI) method may result in crisper edges, while the other three methods are sensitive to noise and artifacts.

A model of the saturation of coupled electron and ion scale gyrokinetic turbulence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Staebler, Gary M.; Howard, Nathan T.; Candy, Jeffrey M.

A new paradigm of zonal flow mixing as the mechanism by which zonal E × B fluctuations impact the saturation of gyrokinetic turbulence has recently been deduced from the nonlinear 2D spectrum of electric potential fluctuations in gyrokinetic simulations. These state of the art simulations span the physical scales of both ion and electron turbulence. It was found that the zonal flow mixing rate, rather than zonal flow shearing rate, competes with linear growth at both electron and ion scales. A model for saturation of the turbulence by the zonal flow mixing was developed and applied to the quasilinear trappedmore » gyro-Landau fluid transport model (TGLF). The first validation tests of the new saturation model are reported in this paper with data from L-mode and high-β p regime discharges from the DIII-D tokamak. Lastly, the shortfall in the predicted L-mode edge electron energy transport is improved with the new saturation model for these discharges but additional multiscale simulations are required in order to verify the safety factor and collisionality dependencies found in the modeling.« less

A model of the saturation of coupled electron and ion scale gyrokinetic turbulence

DOE PAGES

Staebler, Gary M.; Howard, Nathan T.; Candy, Jeffrey M.; ...

2017-05-09

A new paradigm of zonal flow mixing as the mechanism by which zonal E × B fluctuations impact the saturation of gyrokinetic turbulence has recently been deduced from the nonlinear 2D spectrum of electric potential fluctuations in gyrokinetic simulations. These state of the art simulations span the physical scales of both ion and electron turbulence. It was found that the zonal flow mixing rate, rather than zonal flow shearing rate, competes with linear growth at both electron and ion scales. A model for saturation of the turbulence by the zonal flow mixing was developed and applied to the quasilinear trappedmore » gyro-Landau fluid transport model (TGLF). The first validation tests of the new saturation model are reported in this paper with data from L-mode and high-β p regime discharges from the DIII-D tokamak. Lastly, the shortfall in the predicted L-mode edge electron energy transport is improved with the new saturation model for these discharges but additional multiscale simulations are required in order to verify the safety factor and collisionality dependencies found in the modeling.« less

Short-term Morphodynamics of an Eroding Salt Marsh Shoreline in the Delaware Estuary, USA

NASA Astrophysics Data System (ADS)

Fanta, D.; Quirk, T. E.

2017-12-01

Marsh edge morphology can change rapidly through erosional and depositional processes. Along seemingly similar stretches of marsh shoreline, erosion processes and rates can vary dramatically. In the Delaware Estuary, annual rates of edge erosion vary from a few centimeters to several meters across relatively short stretches of shoreline. Differences in erosion processes observed here include areas with and without vegetation growth seaward of the eroding marsh scarp. To better understand the factors that influence changes in marsh edge morphology, we examined wave energy, marsh scarp profile, and vegetation structure in relation to lateral erosion and accretion along two stretches of the Delaware Estuary for two years. Rates of erosion ranged from 0.01 to over 7 m/yr depending on shoreline exposure to waves and location on marsh scarp depth profile. Sediment deposition and accretion were up to an order of magnitude higher 15 cm from the marsh edge than 5 cm from the marsh edge, and were driven by storm events. In some areas, vegetation persisted seaward of eroding marshes where wave activity was dampened by a shallower bathymetric profile. Wave energy, distance from the edge and marsh elevation all contributed to vegetation structure, and therefore sedimentation and accretion dynamics. These results highlight the interactive nature of biophysical processes leading to lateral retreat or potential resilience of marsh edges.

Reduction of wafer-edge overlay errors using advanced correction models, optimized for minimal metrology requirements

NASA Astrophysics Data System (ADS)

Kim, Min-Suk; Won, Hwa-Yeon; Jeong, Jong-Mun; Böcker, Paul; Vergaij-Huizer, Lydia; Kupers, Michiel; Jovanović, Milenko; Sochal, Inez; Ryan, Kevin; Sun, Kyu-Tae; Lim, Young-Wan; Byun, Jin-Moo; Kim, Gwang-Gon; Suh, Jung-Joon

2016-03-01

In order to optimize yield in DRAM semiconductor manufacturing for 2x nodes and beyond, the (processing induced) overlay fingerprint towards the edge of the wafer needs to be reduced. Traditionally, this is achieved by acquiring denser overlay metrology at the edge of the wafer, to feed field-by-field corrections. Although field-by-field corrections can be effective in reducing localized overlay errors, the requirement for dense metrology to determine the corrections can become a limiting factor due to a significant increase of metrology time and cost. In this study, a more cost-effective solution has been found in extending the regular correction model with an edge-specific component. This new overlay correction model can be driven by an optimized, sparser sampling especially at the wafer edge area, and also allows for a reduction of noise propagation. Lithography correction potential has been maximized, with significantly less metrology needs. Evaluations have been performed, demonstrating the benefit of edge models in terms of on-product overlay performance, as well as cell based overlay performance based on metrology-to-cell matching improvements. Performance can be increased compared to POR modeling and sampling, which can contribute to (overlay based) yield improvement. Based on advanced modeling including edge components, metrology requirements have been optimized, enabling integrated metrology which drives down overall metrology fab footprint and lithography cycle time.

A Spread-Spectrum SQUID Multiplexer

NASA Astrophysics Data System (ADS)

Irwin, K. D.; Chaudhuri, S.; Cho, H.-M.; Dawson, C.; Kuenstner, S.; Li, D.; Titus, C. J.; Young, B. A.

2018-06-01

The transition-edge sensor (TES) is a mature, high-resolution x-ray spectrometer technology that provides a much higher efficiency than dispersive spectrometers such as gratings and crystal spectrometers. As larger arrays are developed, time-division multiplexing schemes operating at MHz frequencies are being replaced by microwave SQUID multiplexers using frequency-division multiplexing at GHz frequencies. However, the multiplexing factor achievable with microwave SQUIDs is limited by the high slew rate on the leading edge of x-ray pulses. In this paper, we propose a new multiplexing scheme for high-slew-rate TES x-ray calorimeters: the spread-spectrum SQUID multiplexer, which has the potential to enable higher multiplexing factors, especially in applications with lower photon-arrival rates.

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

NASA Technical Reports Server (NTRS)

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.

Applications of FEM and BEM in two-dimensional fracture mechanics problems

NASA Technical Reports Server (NTRS)

Min, J. B.; Steeve, B. E.; Swanson, G. R.

1992-01-01

A comparison of the finite element method (FEM) and boundary element method (BEM) for the solution of two-dimensional plane strain problems in fracture mechanics is presented in this paper. Stress intensity factors (SIF's) were calculated using both methods for elastic plates with either a single-edge crack or an inclined-edge crack. In particular, two currently available programs, ANSYS for finite element analysis and BEASY for boundary element analysis, were used.

Empirical calibration of a roadside hazardousness index for Spanish two-lane rural roads.

PubMed

Pardillo-Mayora, José M; Domínguez-Lira, Carlos A; Jurado-Piña, Rafael

2010-11-01

Crash records and roadside data from Spanish two-lane rural roads were analyzed to study the effect of roadside configuration on safety. Four indicators were used to characterize the main roadside features that have an influence on the consequences of roadway departures: roadside slope, non-traversable obstacles distance from the roadway edge, safety barrier installation, and alignment. Based on the analysis of the effect of roadside configuration on the frequency and severity of run-off-road injury crashes, a categorical roadside hazardousness scale was defined. Cluster analysis was applied to group the combinations of the four indicators into categories with homogeneous effects on run-off-road injury crashes frequency and severity. As a result a 5-level Roadside Hazardousness Index (RHI) was defined. RHI can be used as reference to normalize the collection of roadside safety related information. The index can also be used as variable for inclusion of roadside condition information in multivariate crash prediction models. 2010 Elsevier Ltd. All rights reserved.

Turbulent flow around a wing-fuselage type juncture

NASA Technical Reports Server (NTRS)

Kubendran, L. R.; Mcmahon, H. M.; Hubbartt, J. E.

1985-01-01

The flow over a 58-mm-thick uniform-thickness winglike body having a 1.5:1 elliptical leading edge and joined to a large flat plate (representing an aircraft fuselage) is characterized experimentally at freestream velocity 15 m/s, corresponding to Reynolds number 940,000/m, using hot-wire anemometry. The results are presented graphically, and it is found that the horseshoe vortex formed by the separation of the fuselage boundary layer ahead of the wing leading edge is effective in transporting turbulence and modifying the mean-flow characteristics and the turbulent-stress distribution. It is suggested that the slenderness ratio of the leading edge is the dominant factor affecting the strength and location of the vortex.

Field reversed configuration confinement enhancement through edge biasing and neutral beam injection.

PubMed

Tuszewski, M; Smirnov, A; Thompson, M C; Korepanov, S; Akhmetov, T; Ivanov, A; Voskoboynikov, R; Schmitz, L; Barnes, D; Binderbauer, M W; Brown, R; Bui, D Q; Clary, R; Conroy, K D; Deng, B H; Dettrick, S A; Douglass, J D; Garate, E; Glass, F J; Gota, H; Guo, H Y; Gupta, D; Gupta, S; Kinley, J S; Knapp, K; Longman, A; Hollins, M; Li, X L; Luo, Y; Mendoza, R; Mok, Y; Necas, A; Primavera, S; Ruskov, E; Schroeder, J H; Sevier, L; Sibley, A; Song, Y; Sun, X; Trask, E; Van Drie, A D; Walters, J K; Wyman, M D

2012-06-22

Field reversed configurations (FRCs) with high confinement are obtained in the C-2 device by combining plasma gun edge biasing and neutral beam injection. The plasma gun creates an inward radial electric field that counters the usual FRC spin-up. The n = 2 rotational instability is stabilized without applying quadrupole magnetic fields. The FRCs are nearly axisymmetric, which enables fast ion confinement. The plasma gun also produces E × B shear in the FRC edge layer, which may explain the observed improved particle transport. The FRC confinement times are improved by factors 2 to 4, and the plasma lifetimes are extended from 1 to up to 4 ms.

An overview of the fundamental aerodynamics branch's research activities in wing leading-edge vortex flows at supersonic speeds

NASA Technical Reports Server (NTRS)

Miller, D. S.; Wood, R. M.; Covell, P. F.

1986-01-01

For the past 3 years, a research program pertaining to the study of wing leading edge vortices at supersonic speeds has been conducted in the Fundamental Aerodynamics Branch of the High-Speed Aerodynamics Division at the Langley Research Center. The purpose of the research is to provide an understanding of the factors governing the formation and the control of wing leading-edge vortices and to evaluate the use of these vortices for improving supersonic aerodynamic performance. The studies include both experimental and theoretical investigations and focus primarily on planform, thickness and camber effects for delta wings. An overview of this research activity is presented.

In situ removal of carbon contamination from a chromium-coated mirror: ideal optics to suppress higher-order harmonics in the carbon K-edge region.

PubMed

Toyoshima, Akio; Kikuchi, Takashi; Tanaka, Hirokazu; Mase, Kazuhiko; Amemiya, Kenta

2015-11-01

Carbon-free chromium-coated optics are ideal in the carbon K-edge region (280-330 eV) because the reflectivity of first-order light is larger than that of gold-coated optics while the second-order harmonics (560-660 eV) are significantly suppressed by chromium L-edge and oxygen K-edge absorption. Here, chromium-, gold- and nickel-coated mirrors have been adopted in the vacuum ultraviolet and soft X-ray branch beamline BL-13B at the Photon Factory in Tsukuba, Japan. Carbon contamination on the chromium-coated mirror was almost completely removed by exposure to oxygen at a pressure of 8 × 10(-2) Pa for 1 h under irradiation of non-monochromated synchrotron radiation. The pressure in the chamber recovered to the order of 10(-7) Pa within a few hours. The reflectivity of the chromium-coated mirror of the second-order harmonics in the carbon K-edge region (560-660 eV) was found to be a factor of 0.1-0.48 smaller than that of the gold-coated mirror.

Evaluating the Effectiveness of an Educational Intervention to Improve the Patient Safety Attitudes of Intern Pharmacists

PubMed Central

Fois, Romano A.; McLachlan, Andrew J.; Chen, Timothy F.

2017-01-01

Objective. To evaluate the effectiveness of a face-to-face educational intervention in improving the patient safety attitudes of intern pharmacists. Methods. A patient safety education program was delivered to intern pharmacists undertaking The University of Sydney Intern Training Program in 2014. Their patient safety attitudes were evaluated immediately prior to, immediately after, and three-months post-intervention. Underlying attitudinal factors were identified using exploratory factor analysis. Changes in factor scores were examined using analysis of variance. Results. Of the 120 interns enrolled, 95 (78.7%) completed all three surveys. Four underlying attitudinal factors were identified: attitudes towards addressing errors, questioning behaviors, blaming individuals, and reporting errors. Improvements in all attitudinal factors were evident immediately after the intervention. However, only improvements in attitudes towards blaming individuals involved in errors were sustained at three months post-intervention. Conclusion. The educational intervention was associated with short-term improvements in pharmacist interns’ patient safety attitudes. However, other factors likely influenced their attitudes in the longer term. PMID:28289295

Evaluating the Effectiveness of an Educational Intervention to Improve the Patient Safety Attitudes of Intern Pharmacists.

PubMed

Walpola, Ramesh L; Fois, Romano A; McLachlan, Andrew J; Chen, Timothy F

2017-02-25

Objective. To evaluate the effectiveness of a face-to-face educational intervention in improving the patient safety attitudes of intern pharmacists. Methods. A patient safety education program was delivered to intern pharmacists undertaking The University of Sydney Intern Training Program in 2014. Their patient safety attitudes were evaluated immediately prior to, immediately after, and three-months post-intervention. Underlying attitudinal factors were identified using exploratory factor analysis. Changes in factor scores were examined using analysis of variance. Results. Of the 120 interns enrolled, 95 (78.7%) completed all three surveys. Four underlying attitudinal factors were identified: attitudes towards addressing errors, questioning behaviors, blaming individuals, and reporting errors. Improvements in all attitudinal factors were evident immediately after the intervention. However, only improvements in attitudes towards blaming individuals involved in errors were sustained at three months post-intervention. Conclusion. The educational intervention was associated with short-term improvements in pharmacist interns' patient safety attitudes. However, other factors likely influenced their attitudes in the longer term.

Positive organizational behavior and safety in the offshore oil industry: Exploring the determinants of positive safety climate.

PubMed

Hystad, Sigurd W; Bartone, Paul T; Eid, Jarle

2014-01-01

Much research has now documented the substantial influence of safety climate on a range of important outcomes in safety critical organizations, but there has been scant attention to the question of what factors might be responsible for positive or negative safety climate. The present paper draws from positive organizational behavior theory to test workplace and individual factors that may affect safety climate. Specifically, we explore the potential influence of authentic leadership style and psychological capital on safety climate and risk outcomes. Across two samples of offshore oil-workers and seafarers working on oil platform supply ships, structural equation modeling yielded results that support a model in which authentic leadership exerts a direct effect on safety climate, as well as an indirect effect via psychological capital. This study shows the importance of leadership qualities as well as psychological factors in shaping a positive work safety climate and lowering the risk of accidents.

Positive organizational behavior and safety in the offshore oil industry: Exploring the determinants of positive safety climate

PubMed Central

Hystad, Sigurd W.; Bartone, Paul T.; Eid, Jarle

2013-01-01

Much research has now documented the substantial influence of safety climate on a range of important outcomes in safety critical organizations, but there has been scant attention to the question of what factors might be responsible for positive or negative safety climate. The present paper draws from positive organizational behavior theory to test workplace and individual factors that may affect safety climate. Specifically, we explore the potential influence of authentic leadership style and psychological capital on safety climate and risk outcomes. Across two samples of offshore oil-workers and seafarers working on oil platform supply ships, structural equation modeling yielded results that support a model in which authentic leadership exerts a direct effect on safety climate, as well as an indirect effect via psychological capital. This study shows the importance of leadership qualities as well as psychological factors in shaping a positive work safety climate and lowering the risk of accidents. PMID:24454524

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

PubMed

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.

Effectiveness and tolerability of second-line therapy with vildagliptin vs. other oral agents in type 2 diabetes: A real-life worldwide observational study (EDGE)

PubMed Central

Mathieu, C; Barnett, A H; Brath, H; Conget, I; de Castro, J J; Göke, R; Márquez Rodriguez, E; Nilsson, P M; Pagkalos, E; Penfornis, A; Schaper, NC; Wangnoo, S K; Kothny, W; Bader, G

2013-01-01

Aim Real-life studies are needed to confirm the clinical relevance of findings from randomised controlled trials (RCTs). This study aimed to assess the effectiveness and tolerability of vildagliptin add-on vs. other oral antihyperglycaemic drugs (OADs) added to OAD monotherapy in a real-life setting, and to explore the advantages and limitations of large-scale ‘pragmatic’ trials. Methods EDGE was a prospective, 1-year, worldwide, real-life observational study in which 2957 physicians reported on the effects of second-line OADs in 45,868 patients with T2DM not reaching glycaemic targets with monotherapy. Physicians could add any OAD, and patients entered either vildagliptin or (pooled) comparator cohort. The primary effectiveness and tolerability end-point (PEP) evaluated proportions of patients decreasing HbA1c > 0.3%, without hypoglycaemia, weight gain, peripheral oedema or gastrointestinal side effects. The most clinically relevant secondary end-point (SEP 3) was attainment of end-point HbA1c < 7% without hypoglycaemia or ≥ 3% increase in body weight. Results In this large group of T2DM patients, a second OAD was added at mean HbA1c of 8.2 ± 1.3%, with no baseline HbA1c difference between cohorts. Second-line OAD therapy attained the PEP in the majority of patients, with higher attainment in those prescribed a vildagliptin-based regimen. The adjusted odds ratio was 1.49 (95% CI: 1.42, 1.55; p < 0.001). In patients with baseline HbA1c ≥ 7%, SEP 3 was achieved by 35% of patients on a vildagliptin-based combination and by 23% of those receiving comparator combinations. The adjusted odds ratio was 1.96 (95% CI: 1.85, 2.07; p < 0.001). Safety events were reported infrequently and safety profiles of vildagliptin and other OADs were consistent with previous data. Conclusion EDGE demonstrates that in a ‘real-life’ setting, vildagliptin as second OAD can lower HbA1c to target without well-recognised OAD side effects, more frequently than comparator OADs. In addition, EDGE illustrates that conducting large-scale, prospective, real-life studies poses challenges but yields valuable clinical information complementary to RCTs. PMID:23961850

Calculating and Mitigating the Risk of a Cut Glove to a Space Walking Astronaut

NASA Technical Reports Server (NTRS)

Castillo, Theresa; Haught, Megan

2013-01-01

One of the high risk operations on the International Space Station (ISS) is conducting a space walk, or an Extra Vehicular Activity (EVA). Threats to the space walking crew include airlock failures, space suit failures, and strikes from micro ]meteoroids and orbital debris (MM/OD). There are risks of becoming untethered from the space station, being pinched between the robotic arm and a piece of equipment, tearing your suit on a sharp edge, and other human errors that can be catastrophic. For decades NASA identified and tried to control sharp edges on external structure and equipment by design; however a new and unexpected source of sharp edges has since become apparent. Until recently, one of the underappreciated environmental risks was damage to EVA gloves during a spacewalk. The ISS has some elements which have been flying in the environment of space for over 14 years. It has and continues to be bombarded with MM/OD strikes that have created small, sharp craters all over the structure, including the dedicated EVA handrails and surrounding structure. These craters are capable of cutting through several layers of the EVA gloves. Starting in 2006, five EVA crewmembers reported cuts in their gloves so large they rendered the gloves unusable and in some cases cut the spacewalk short for the safety of the crew. This new hazard took engineers and managers by surprise. NASA has set out to mitigate this risk to safety and operations by redesigning the spacesuit gloves to be more resilient and designing a clamp to isolate MM/OD strikes on handrails, and is considering the necessity of an additional tool to repair strikes on non ]handrail surfaces (such as a file). This paper will address how the ISS Risk Team quantified an estimate of the MM/OD damage to the ISS, and the resulting likelihood of sustaining a cut glove in order to measure the effectiveness of the solutions being investigated to mitigate this risk to the mission and crew.

Computational nanometrology of line-edge roughness: noise effects, cross-line correlations and the role of etch transfer

NASA Astrophysics Data System (ADS)

Constantoudis, Vassilios; Papavieros, George; Lorusso, Gian; Rutigliani, Vito; Van Roey, Frieda; Gogolides, Evangelos

2018-03-01

The aim of this paper is to investigate the role of etch transfer in two challenges of LER metrology raised by recent evolutions in lithography: the effects of SEM noise and the cross-line and edge correlations. The first comes from the ongoing scaling down of linewidths, which dictates SEM imaging with less scanning frames to reduce specimen damage and hence with more noise. During the last decade, it has been shown that image noise can be an important budget of the measured LER while systematically affects and alter the PSD curve of LER at high frequencies. A recent method for unbiased LER measurement is based on the systematic Fourier or correlation analysis to decompose the effects of noise from true LER (Fourier-Correlation filtering method). The success of the method depends on the PSD and HHCF curve. Previous experimental and model works have revealed that etch transfer affects the PSD of LER reducing its high frequency values. In this work, we estimate the noise contribution to the biased LER through PSD flat floor at high frequencies and relate it with the differences between the PSDs of lithography and etched LER. Based on this comparison, we propose an improvement of the PSD/HHCF-based method for noise-free LER measurement to include the missed high frequency real LER. The second issue is related with the increased density of lithographic patterns and the special characteristics of DSA and MP lithography patterns exhibits. In a previous work, we presented an enlarged LER characterization methodology for such patterns, which includes updated versions of the old metrics along with new metrics defined and developed to capture cross-edge and cross-line correlations. The fundamental concept has been the Line Center Roughness (LCR), the edge c-factor and the line c-factor correlation function and length quantifying the line fluctuations and the extent of cross-edge and cross-line correlations. In this work, we focus on the role of etch steps on cross-edge and line correlation metrics in SAQP data. We find that the spacer etch steps reduce edge correlations while etch steps with pattern transfer increase these. Furthermore, the density doubling and quadrupling increase edge correlations as well as cross-line correlations.

Highest drought sensitivity and lowest resistance to growth suppression are found in the range core of the tree Fagus sylvatica L. not the equatorial range edge.

PubMed

Cavin, Liam; Jump, Alistair S

2017-01-01

Biogeographical and ecological theory suggests that species distributions should be driven to higher altitudes and latitudes as global temperatures rise. Such changes occur as growth improves at the poleward edge of a species distribution and declines at the range edge in the opposite or equatorial direction, mirrored by changes in the establishment of new individuals. A substantial body of evidence demonstrates that such processes are underway for a wide variety of species. Case studies from populations at the equatorial range edge of a variety of woody species have led us to understand that widespread growth decline and distributional shifts are underway. However, in apparent contrast, other studies report high productivity and reproduction in some range edge populations. We sought to assess temporal trends in the growth of the widespread European beech tree (Fagus sylvatica) across its latitudinal range. We explored the stability of populations to major drought events and the implications for predicted widespread growth decline at its equatorial range edge. In contrast to expectations, we found greatest sensitivity and low resistance to drought in the core of the species range, whilst dry range edge populations showed particularly high resistance to drought and little evidence of drought-linked growth decline. We hypothesize that this high range edge resistance to drought is driven primarily by local environmental factors that allow relict populations to persist despite regionally unfavourable climate. The persistence of such populations demonstrates that range-edge decline is not ubiquitous and is likely to be driven by declining population density at the landscape scale rather than sudden and widespread range retraction. © 2016 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Characterization of wear debris from metal-on-metal hip implants during normal wear versus edge-loading conditions.

PubMed

Kovochich, Michael; Fung, Ernest S; Donovan, Ellen; Unice, Kenneth M; Paustenbach, Dennis J; Finley, Brent L

2018-04-01

Advantages of second-generation metal-on-metal (MoM) hip implants include low volumetric wear rates and the release of nanosized wear particles that are chemically inert and readily cleared from local tissue. In some patients, edge loading conditions occur, which result in higher volumetric wear. The objective of this study was to characterize the size, morphology, and chemistry of wear particles released from MoM hip implants during normal (40° angle) and edge-loading (65° angle with microseparation) conditions. The mean primary particle size by volume under normal wear was 35 nm (range: 9-152 nm) compared with 95 nm (range: 6-573 nm) under edge-loading conditions. Hydrodynamic diameter analysis by volume showed that particles from normal wear were in the nano- (<100 nm) to submicron (<1000 nm) size range, whereas edge-loading conditions generated particles that ranged from <100 nm up to 3000-6000 nm in size. Particles isolated from normal wear were primarily chromium (98.5%) and round to oval in shape. Edge-loading conditions generated more elongated particles (4.5%) (aspect ratio ≥ 2.5) and more CoCr alloy particles (9.3%) compared with normal wear conditions (1.3% CoCr particles). By total mass, edge-loading particles contained approximately 640-fold more cobalt than normal wear particles. Our findings suggest that high wear conditions are a potential risk factor for adverse local tissue effects in MoM patients who experience edge loading. This study is the first to characterize both the physical and chemical characteristics of MoM wear particles collected under normal and edge-loading conditions. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 986-996, 2018. © 2017 Wiley Periodicals, Inc.

[The value of horizontal discrepancy on the subgingival position of the tooth crown].

PubMed

Redzepagić, S

1997-01-01

Marginal adaptation of the crown edge has been considered as primary and significant factor of prevention of secondary caries and periodontal disease on carryig tooth. There has been a clear dependence between hunting the periodontal tissue and the quality of edge closing of the crown. If we position subgingivaly the crown which clinically shows a good adoptiveness marginally and at the same time we position marginal crease in the ginguival sucus that should rush the accumulation of the plaque. The bacteries in the plaque would cause the inflammation of ginguive. The end of the crown edge in gingival sucus would cause chronic inflammation at ginguival tissue. The existence of transit zone that includes the crown edge, prepared tooth and dental cement became important if the crown edge has been positioned subgingivaly. If the crown edge ends in the ginguival sucus, the tooth meat is constantly being irritated that results with different degrees of inflammations. In many cases it causes ginguival dislocation. The possibility of clinical control of marginal positioning of subgingivaly positioned crown edge on demarcation line does not exist in terminal phase of cementing. The crown cement can be substratum of bacterial receptiveness and the plaque accumulation in the ginguival sucus. The procedure of cementing is an important cause of incomplete edge closing of the crown on the demarcation line. The form of demarcation line determine the form and the width of crown. They are favorising and degrading the level of marginal adaptations. The existing of horizontal discrepancy at the relation of based tooth--the crown edge is unavoidable. The question is if the amount of this discrepancy fits the assumed biological optimum.

Human factors systems approach to healthcare quality and patient safety

PubMed Central

Carayon, Pascale; Wetterneck, Tosha B.; Rivera-Rodriguez, A. Joy; Hundt, Ann Schoofs; Hoonakker, Peter; Holden, Richard; Gurses, Ayse P.

2013-01-01

Human factors systems approaches are critical for improving healthcare quality and patient safety. The SEIPS (Systems Engineering Initiative for Patient Safety) model of work system and patient safety is a human factors systems approach that has been successfully applied in healthcare research and practice. Several research and practical applications of the SEIPS model are described. Important implications of the SEIPS model for healthcare system and process redesign are highlighted. Principles for redesigning healthcare systems using the SEIPS model are described. Balancing the work system and encouraging the active and adaptive role of workers are key principles for improving healthcare quality and patient safety. PMID:23845724

Human factors and ergonomics as a patient safety practice

PubMed Central

Carayon, Pascale; Xie, Anping; Kianfar, Sarah

2014-01-01

Background Human factors and ergonomics (HFE) approaches to patient safety have addressed five different domains: usability of technology; human error and its role in patient safety; the role of healthcare worker performance in patient safety; system resilience; and HFE systems approaches to patient safety. Methods A review of various HFE approaches to patient safety and studies on HFE interventions was conducted. Results This paper describes specific examples of HFE-based interventions for patient safety. Studies show that HFE can be used in a variety of domains. Conclusions HFE is a core element of patient safety improvement. Therefore, every effort should be made to support HFE applications in patient safety. PMID:23813211

Safety climate practice in Korean manufacturing industry.

PubMed

Baek, Jong-Bae; Bae, Sejong; Ham, Byung-Ho; Singh, Karan P

2008-11-15

Safety climate survey was sent to 642 plants in 2003 to explore safety climate practices in the Korean manufacturing plants, especially in hazardous chemical treating plants. Out of 642 plants contacted 195 (30.4%) participated in the surveys. Data were collected by e-mail using SQL-server and mail. The main objective of this study was to explore safety climate practices (level of safety climate and the underlying problems). In addition, the variables that may influence the level of safety climate among managers and workers were explored. The questionnaires developed by health and safety executive (HSE) in the UK were modified to incorporate differences in Korean culture. Eleven important factors were summarized. Internal reliability of these factors was validated. Number of employees in the company varied from less than 30 employees (9.2%) to over 1000 employees (37.4%). Both managers and workers showed generally high level of safety climate awareness. The major underlying problems identified were inadequate health and safety procedures/rules, pressure for production, and rule breaking. The length of employment was a significant contributing factor to the level of safety climate. In this study, participants showed generally high level of safety climate, and length of employment affected the differences in the level of safety climate. Managers' commitment to comply safety rules, procedures, and effective safety education and training are recommended.

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

Federal Register 2010, 2011, 2012, 2013, 2014

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...

Electron-beam induced amorphization of stishovite: Silicon-coordination change observed using Si K-edge extended electron energy-loss fine structure

NASA Astrophysics Data System (ADS)

van Aken, P. A.; Sharp, T. G.; Seifert, F.

The analysis of the extended energy-loss fine structure (EXELFS) of the Si K-edge for sixfold-coordinated Si in synthetic stishovite and fourfold-coordinated Si in natural α-quartz is reported by using electron energy-loss spectroscopy (EELS) in combination with transmission electron microscopy (TEM). The stishovite Si K-edge EXELFS spectra were measured as a time-dependent series to document irradiation-induced amorphization. The amorphization was also investigated through the change in Si K- and O K-edge energy-loss near edge structure (ELNES). For α-quartz, in contrast to stishovite, electron irradiation-induced vitrification, verified by selected area electron diffraction (SAED), produced no detectable changes of the EXELFS. The Si K-edge EXELFS were analysed with the classical extended X-ray absorption fine structure (EXAFS) treatment and compared to ab initio curve-waved multiple-scattering (MS) calculations of EXAFS spectra for stishovite and α-quartz. Highly accurate information on the local atomic environment of the silicon atoms during the irradiation-induced amorphization of stishovite is obtained from the EXELFS structure parameters (Si-O bond distances, coordination numbers and Debye-Waller factors). The mean Si-O bond distance R and mean Si coordination number N changes from R=0.1775 nm and N=6 for stishovite through a disordered intermediate state (R 0.172 nm and N 5) to R 0.167 nm and N 4.5 for a nearly amorphous state similar to α-quartz (R=0.1609 nm and N=4). During the amorphization process, the Debye-Waller factor (DWF) passes through a maximum value of as it changes from for sixfold to for fourfold coordination of Si. This increase in Debye-Waller factor indicates an increase in mean-square relative displacement (MSRD) between the central silicon atom and its oxygen neighbours that is consistent with the presence of an intermediate structural state with fivefold coordination of Si. The distribution of coordination states can be estimated by modelling the amorphization as a decay process. Using the EXELFS data for amorphization, a new method is developed to derive the relative amounts of Si coordinations in high-pressure minerals with mixed coordination. For the radiation-induced amorphization process of stishovite the formation of a transitory structure with Si largely in fivefold coordination is deduced.

Effect of disorder on longitudinal resistance of a graphene p-n junction in the quantum Hall regime

NASA Astrophysics Data System (ADS)

Chen, Jiang-Chai; Yeung, T. C. Au; Sun, Qing-Feng

2010-06-01

The longitudinal resistances of a six-terminal graphene p-n junction under a perpendicular magnetic field are investigated. Because of the chirality of the Hall edge states, the longitudinal resistances on top and bottom edges of the graphene ribbon are not equal. In the presence of suitable disorder, the top-edge and bottom-edge resistances well show the plateau structures in the both unipolar and bipolar regimes, and the plateau values are determined by the Landau filling factors only. These plateau structures are in excellent agreement with the recent experiment. For the unipolar junction, the resistance plateaus emerge in the absence of impurity and they are destroyed by strong disorder. But for the bipolar junction, the resistances are very large without the plateau structures in the clean junction. The disorder can strongly reduce the resistances and leads the formation of the resistance plateaus due to the mixture of the Hall edge states in virtue of the disorder. In addition, the size effect of the junction on the resistances is studied and some extra resistance plateaus are found in the long graphene junction case. This is explained by the fact that only part of the edge states participate in the full mixing.

Efficient Approximation Algorithms for Weighted $b$-Matching

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Arif; Pothen, Alex; Mostofa Ali Patwary, Md.

2016-01-01

We describe a half-approximation algorithm, b-Suitor, for computing a b-Matching of maximum weight in a graph with weights on the edges. b-Matching is a generalization of the well-known Matching problem in graphs, where the objective is to choose a subset of M edges in the graph such that at most a specified number b(v) of edges in M are incident on each vertex v. Subject to this restriction we maximize the sum of the weights of the edges in M. We prove that the b-Suitor algorithm computes the same b-Matching as the one obtained by the greedy algorithm for themore » problem. We implement the algorithm on serial and shared-memory parallel processors, and compare its performance against a collection of approximation algorithms that have been proposed for the Matching problem. Our results show that the b-Suitor algorithm outperforms the Greedy and Locally Dominant edge algorithms by one to two orders of magnitude on a serial processor. The b-Suitor algorithm has a high degree of concurrency, and it scales well up to 240 threads on a shared memory multiprocessor. The b-Suitor algorithm outperforms the Locally Dominant edge algorithm by a factor of fourteen on 16 cores of an Intel Xeon multiprocessor.« less

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

NASA Astrophysics Data System (ADS)

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.

Species-specific differences in relative eye size are related to patterns of edge avoidance in an Amazonian rainforest bird community

PubMed Central

Martínez-Ortega, Cristina; Santos, Eduardo SA; Gil, Diego

2014-01-01

Eye size shows a large degree of variation among species, even after correcting for body size. In birds, relatively larger eyes have been linked to predation risk, capture of mobile prey, and nocturnal habits. Relatively larger eyes enhance visual acuity and also allow birds to forage and communicate in low-light situations. Complex habitats such as tropical rain forests provide a mosaic of diverse lighting conditions, including differences among forest strata and at different distances from the forest edge. We examined in an Amazonian forest bird community whether microhabitat occupancy (defined by edge avoidance and forest stratum) was a predictor of relative eye size. We found that relative eye size increased with edge avoidance, but did not differ according to forest stratum. Nevertheless, the relationship between edge avoidance and relative eye size showed a nonsignificant positive trend for species that inhabit lower forest strata. Our analysis shows that birds that avoid forest edges have larger eyes than those living in lighter parts. We expect that this adaptation may allow birds to increase their active daily period in dim areas of the forest. The pattern that we found raises the question of what factors may limit the evolution of large eyes. PMID:25614788

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

NASA Astrophysics Data System (ADS)

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.

Design of an Insulin Analog with Enhanced Receptor Binding Selectivity

PubMed Central

Zhao, Ming; Wan, Zhu-li; Whittaker, Linda; Xu, Bin; Phillips, Nelson B.; Katsoyannis, Panayotis G.; Ismail-Beigi, Faramarz; Whittaker, Jonathan; Weiss, Michael A.

2009-01-01

Insulin binds with high affinity to the insulin receptor (IR) and with low affinity to the type 1 insulin-like growth factor (IGF) receptor (IGFR). Such cross-binding, which reflects homologies within the insulin-IGF signaling system, is of clinical interest in relation to the association between hyperinsulinemia and colorectal cancer. Here, we employ nonstandard mutagenesis to design an insulin analog with enhanced affinity for the IR but reduced affinity for the IGFR. Unnatural amino acids were introduced by chemical synthesis at the N- and C-capping positions of a recognition α-helix (residues A1 and A8). These sites adjoin the hormone-receptor interface as indicated by photocross-linking studies. Specificity is enhanced more than 3-fold on the following: (i) substitution of GlyA1 by d-Ala or d-Leu, and (ii) substitution of ThrA8 by diaminobutyric acid (Dab). The crystal structure of [d-AlaA1,DabA8]insulin, as determined within a T6 zinc hexamer to a resolution of 1.35 Å, is essentially identical to that of human insulin. The nonstandard side chains project into solvent at the edge of a conserved receptor-binding surface shared by insulin and IGF-I. Our results demonstrate that modifications at this edge discriminate between IR and IGFR. Because hyperinsulinemia is typically characterized by a 3-fold increase in integrated postprandial insulin concentrations, we envisage that such insulin analogs may facilitate studies of the initiation and progression of cancer in animal models. Future development of clinical analogs lacking significant IGFR cross-binding may enhance the safety of insulin replacement therapy in patients with type 2 diabetes mellitus at increased risk of colorectal cancer. PMID:19773552

Scaling of the MHD perturbation amplitude required to trigger a disruption and predictions for ITER

NASA Astrophysics Data System (ADS)

de Vries, P. C.; Pautasso, G.; Nardon, E.; Cahyna, P.; Gerasimov, S.; Havlicek, J.; Hender, T. C.; Huijsmans, G. T. A.; Lehnen, M.; Maraschek, M.; Markovič, T.; Snipes, J. A.; the COMPASS Team; the ASDEX Upgrade Team; Contributors, JET

2016-02-01

The amplitude of locked instabilities, likely magnetic islands, seen as precursors to disruptions has been studied using data from the JET, ASDEX Upgrade and COMPASS tokamaks. It was found that the thermal quench, that often initiates the disruption, is triggered when the amplitude has reached a distinct level. This information can be used to determine thresholds for simple disruption prediction schemes. The measured amplitude in part depends on the distance of the perturbation to the measurement coils. Hence the threshold for the measured amplitude depends on the mode location (i.e. the rational q-surface) and thus indirectly on parameters such as the edge safety factor, q 95, and the internal inductance, li(3), that determine the shape of the q-profile. These dependencies can be used to set the disruption thresholds more precisely. For the ITER baseline scenario, with typically q 95  =  3.2, li(3)  =  0.9 and taking into account the position of the measurement coils on ITER, the maximum allowable measured locked mode amplitude normalized to engineering parameters was estimated to be a·B ML(r c)/I p  =  0.92 m mT/MA, or directly as a fraction edge poloidal magnetic field: B ML(r c)/B θ (a)  =  5 · 10-3. But these values decrease for operation at higher q 95 or lower li(3). The analysis found furthermore that the above empirical criterion to trigger a thermal quench is more consistent with a criterion derived with the concept of a critical island size, i.e. the thermal quench seemed to be triggered at a distinct island width.

Determinants of field edge habitat restoration on farms in California's Sacramento Valley.

PubMed

Garbach, Kelly; Long, Rachael Freeman

2017-03-15

Degradation and loss of biodiversity and ecosystem services pose major challenges in simplified agricultural landscapes. Consequently, best management practices to create or restore habitat areas on field edges and other marginal areas have received a great deal of recent attention and policy support. Despite this, remarkably little is known about how landholders (farmers and landowners) learn about field edge management practices and which factors facilitate, or hinder, adoption of field edge plantings. We surveyed 109 landholders in California's Sacramento Valley to determine drivers of adoption of field edge plantings. The results show the important influence of landholders' communication networks, which included two key roles: agencies that provide technical support and fellow landholders. The networks of landholders that adopted field edge plantings included both fellow landholders and agencies, whereas networks of non-adopters included either landholders or agencies. This pattern documents that social learning through peer-to-peer information exchange can serve as a complementary and reinforcing pathway with technical learning that is stimulated by traditional outreach and extension programs. Landholder experience with benefits and concerns associated with field edge plantings were also significant predictors of adoption. Our results suggest that technical learning, stimulated by outreach and extension, may provide critical and necessary support for broad-scale adoption of field-edge plantings, but that this alone may not be sufficient. Instead, outreach and extension efforts may need to be strategically expanded to incorporate peer-to-peer communication, which can provide critical information on benefits and concerns. Copyright © 2016 Elsevier Ltd. All rights reserved.

14 CFR 25.619 - Special factors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Special factors. 25.619 Section 25.619... STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction General § 25.619 Special factors. The factor of safety prescribed in § 25.303 must be multiplied by the highest pertinent special factor of safety...

The Safety Attitudes Questionnaire: psychometric properties, benchmarking data, and emerging research

PubMed Central

Sexton, John B; Helmreich, Robert L; Neilands, Torsten B; Rowan, Kathy; Vella, Keryn; Boyden, James; Roberts, Peter R; Thomas, Eric J

2006-01-01

Background There is widespread interest in measuring healthcare provider attitudes about issues relevant to patient safety (often called safety climate or safety culture). Here we report the psychometric properties, establish benchmarking data, and discuss emerging areas of research with the University of Texas Safety Attitudes Questionnaire. Methods Six cross-sectional surveys of health care providers (n = 10,843) in 203 clinical areas (including critical care units, operating rooms, inpatient settings, and ambulatory clinics) in three countries (USA, UK, New Zealand). Multilevel factor analyses yielded results at the clinical area level and the respondent nested within clinical area level. We report scale reliability, floor/ceiling effects, item factor loadings, inter-factor correlations, and percentage of respondents who agree with each item and scale. Results A six factor model of provider attitudes fit to the data at both the clinical area and respondent nested within clinical area levels. The factors were: Teamwork Climate, Safety Climate, Perceptions of Management, Job Satisfaction, Working Conditions, and Stress Recognition. Scale reliability was 0.9. Provider attitudes varied greatly both within and among organizations. Results are presented to allow benchmarking among organizations and emerging research is discussed. Conclusion The Safety Attitudes Questionnaire demonstrated good psychometric properties. Healthcare organizations can use the survey to measure caregiver attitudes about six patient safety-related domains, to compare themselves with other organizations, to prompt interventions to improve safety attitudes and to measure the effectiveness of these interventions. PMID:16584553

Evaluation of finite-element models and stress-intensity factors for surface cracks emanating from stress concentrations

NASA Technical Reports Server (NTRS)

Tan, P. W.; Raju, I. S.; Shivakumar, K. N.; Newman, J. C., Jr.

1990-01-01

A re-evaluation of the 3-D finite-element models and methods used to analyze surface crack at stress concentrations is presented. Previous finite-element models used by Raju and Newman for surface and corner cracks at holes were shown to have ill-shaped elements at the intersection of the hole and crack boundaries. Improved models, without these ill-shaped elements, were developed for a surface crack at a circular hole and at a semi-circular edge notch. Stress-intensity factors were calculated by both the nodal-force and virtual-crack-closure methods. Comparisons made between the previously developed stress-intensity factor equations and the results from the improved models agreed well except for configurations with large notch-radii-to-plate-thickness ratios. Stress-intensity factors for a semi-elliptical surface crack located at the center of a semi-circular edge notch in a plate subjected to remote tensile loadings were calculated using the improved models.

Stress intensity and crack displacement for small edge cracks

NASA Technical Reports Server (NTRS)

Orange, Thomas W.

1988-01-01

The weight function method was used to derive stress intensity factors and crack mouth displacement coefficients for small edge cracks (less than 20 percent of the specimen width) in common fracture specimen configurations. Contact stresses due to point application of loads were found to be small but significant for three-point bending and insignificant for four-point bending. The results are compared with available equations and numerical solutions from the literature and with unpublished boundary collocation results.

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

PubMed

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.

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

PubMed

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.

Flight Investigation of the Low-Speed Characteristics of a 45 deg Swept-Wing Fighter-Type Airplane with Blowing Boundary-Layer Control Applied to the Leading- and Trailing-Edge Flaps

NASA Technical Reports Server (NTRS)

Quigley, Hervey C.; Anderson, Seth B.; Innis, Robert C.

1960-01-01

A flight investigation has been conducted to study how pilots use the high lift available with blowing-type boundary-layer control applied to the leading- and trailing-edge flaps of a 45 deg. swept-wing airplane. The study includes documentation of the low-speed handling qualities as well as the pilots' evaluations of the landing-approach characteristics. All the pilots who flew the airplane considered it more comfortable to fly at low speeds than any other F-100 configuration they had flown. The major improvements noted were the reduced stall speed, the improved longitudinal stability at high lift, and the reduction in low-speed buffet. The study has shown the minimum comfortable landing-approach speeds are between 120.5 and 126.5 knots compared to 134 for the airplane with a slatted leading edge and the same trailing-edge flap. The limiting factors in the pilots' choices of landing-approach speeds were the limits of ability to control flight-path angle, lack of visibility, trim change with thrust, low static directional stability, and sluggish longitudinal control. Several of these factors were found to be associated with the high angles of attack, between 13 deg. and 15 deg., required for the low approach speeds. The angle of attack for maximum lift coefficient was 28 deg.

21 CFR 601.32 - General factors relevant to safety and effectiveness.

Code of Federal Regulations, 2010 CFR

2010-04-01

... SERVICES (CONTINUED) BIOLOGICS LICENSING Diagnostic Radiopharmaceuticals § 601.32 General factors relevant to safety and effectiveness. FDA's determination of the safety and effectiveness of a diagnostic radiopharmaceutical includes consideration of the following: (a) The proposed use of the diagnostic...

Aviation Maintenance Safety Articles, January/February 1990

DTIC Science & Technology

1990-02-01

actually looked at the fast that you don’t know you’re response of the crew kept the deck-edge fire stations? Do tired or hurt. It wasn’t until fire...connector. Approx- tenance supervisors are caught up in administrative imately 2 inches of wire was added to the harness, tasks, and they fail to excercise ... fast -acting strain of dry rot attacked ear -ly preventable, the container within seven days prior to the accep- The proper routing for the arming cable

Assessment of Superstructure Ice Protection as Applied to Offshore Oil Operations Safety: Problems, Hazards, Needs, and Potential Transfer Technologies

DTIC Science & Technology

2008-09-01

thermostats, or materials such as carbon layers, which vary in thickness with location and are self - healing and self - regulating. Ships commonly use heating...aircraft today. Pneumatic deicing systems consist of rubber or other elastomeric boots placed on the leading edge of an aircraft wing or on any surface...by Kenney, two as- semblies consisting of neoprene rubber and urethane-coated Dacron fabric were hung from bulkheads where icing would occur. A timer

How to build a model illustrating sea-floor spreading and subduction

USGS Publications Warehouse

Lahr, J.C.

1999-01-01

This report describes how to build a model of the outer 300 km (180 miles) of the Earth that can be used to develop a better understanding of the principal features of plate tectonics, including sea-floor spreading, the pattern of magnetic stripes frozen into the sea floor, transform faulting, thrust faulting, subduction, and volcanism. In addition to a paper copy of this report, the materials required are a cardboard shoebox, glue, scissors, straight edge, and safety razor blade.

Technology Innovations from NASA's Next Generation Launch Technology Program

NASA Technical Reports Server (NTRS)

Cook, Stephen A.; Morris, Charles E. K., Jr.; Tyson, Richard W.

2004-01-01

NASA's Next Generation Launch Technology Program has been on the cutting edge of technology, improving the safety, affordability, and reliability of future space-launch-transportation systems. The array of projects focused on propulsion, airframe, and other vehicle systems. Achievements range from building miniature fuel/oxygen sensors to hot-firings of major rocket-engine systems as well as extreme thermo-mechanical testing of large-scale structures. Results to date have significantly advanced technology readiness for future space-launch systems using either airbreathing or rocket propulsion.

Current challenges and trends in the discovery of agrochemicals.

PubMed

Lamberth, Clemens; Jeanmart, Stephane; Luksch, Torsten; Plant, Andrew

2013-08-16

Crop protection chemistry has come a long way from its "alchemic" beginnings in the late 19th century to a high-tech science that supports the sustainable production of food, feed, and fiber for a rapidly growing population. Cutting-edge developments in the design and synthesis of agrochemicals help to tackle today's challenges of weed and pest resistance, higher regulatory safety margins, and higher cost of goods with the invention of selective, environmentally benign, low use rate, and cost-effective active ingredients.

A spatially adaptive total variation regularization method for electrical resistance tomography

NASA Astrophysics Data System (ADS)

Song, Xizi; Xu, Yanbin; Dong, Feng

2015-12-01

The total variation (TV) regularization method has been used to solve the ill-posed inverse problem of electrical resistance tomography (ERT), owing to its good ability to preserve edges. However, the quality of the reconstructed images, especially in the flat region, is often degraded by noise. To optimize the regularization term and the regularization factor according to the spatial feature and to improve the resolution of reconstructed images, a spatially adaptive total variation (SATV) regularization method is proposed. A kind of effective spatial feature indicator named difference curvature is used to identify which region is a flat or edge region. According to different spatial features, the SATV regularization method can automatically adjust both the regularization term and regularization factor. At edge regions, the regularization term is approximate to the TV functional to preserve the edges; in flat regions, it is approximate to the first-order Tikhonov (FOT) functional to make the solution stable. Meanwhile, the adaptive regularization factor determined by the spatial feature is used to constrain the regularization strength of the SATV regularization method for different regions. Besides, a numerical scheme is adopted for the implementation of the second derivatives of difference curvature to improve the numerical stability. Several reconstruction image metrics are used to quantitatively evaluate the performance of the reconstructed results. Both simulation and experimental results indicate that, compared with the TV (mean relative error 0.288, mean correlation coefficient 0.627) and FOT (mean relative error 0.295, mean correlation coefficient 0.638) regularization methods, the proposed SATV (mean relative error 0.259, mean correlation coefficient 0.738) regularization method can endure a relatively high level of noise and improve the resolution of reconstructed images.

Quantifying the costs and benefits of occupational health and safety interventions at a Bangladesh shipbuilding company

PubMed Central

Thiede, Irene; Thiede, Michael

2015-01-01

Background: This study is the first cost–benefit analysis (CBA) of occupational health and safety (OHS) in a low-income country. It focuses on one of the largest shipbuilding companies in Bangladesh, where globally recognised Occupational Health and Safety Advisory Services (OHSAS) 18001 certification was achieved in 2012. Objectives: The study examines the relative costs of implementing OHS measures against qualitative and quantifiable benefits of implementation in order to determine whether OHSAS measures are economically advantageous. Methods: Quantifying past costs and benefits and discounting future ones, this study looks at the returns of OHS measures at Western Marine Shipbuilding Company Ltd. Results: Costs included investments in workplace and environmental safety, a new clinic that also serves the community, and personal protective equipment (PPE) and training. The results are impressive: previously high injury statistics dropped to close to zero. Conclusions: OHS measures decrease injuries, increase efficiency, and bring income security to workers’ families. Certification has proven a competitive edge for the shipyard, resulting in access to greater markets. Intangible benefits such as trust, motivation and security are deemed crucial in the CBA, and this study finds the high investments made are difficult to offset with quantifiable benefits alone. PMID:25589369

Prescription safety eyewear: impact studies of lens and frame failure.

PubMed

Vinger, P F; Woods, T A

2000-02-01

To determine if a plano lens could be the test lens for all prescription (Rx) lenses and to investigate why Rx lenses pop out of safety eyewear. Plano and Rx polycarbonate lenses (n = 641) with varying thickness and edge geometry, mounted on steel lens holders, and Rx safety eyewear (n = 128) placed on headforms were impacted with test objects of varying diameter and hardness. Impacts were studied with 500 to 2,000 frames-per-second motion analysis. Plano lenses were at least, or more, prone to failure (dislodgment, perforation, shatter, or crack) than -3.00 or +3.00 lenses of the same minimum thickness. More than 40% of safety frames with removable lenses broke or had lenses pop out when impacted with energies expected in industry and sports. Plano lenses can be used as the test lenses for all Rx lenses made of the same material with the same minimal thickness. The ANSI Z87.1-1989 industrial standard for Rx eyewear is inadequate for sports or other activities with high-impact potential. The best lens-retention system has, as a component, a frame with a bevel perpendicular to a frontal impact force.

Quantifying the costs and benefits of occupational health and safety interventions at a Bangladesh shipbuilding company.

PubMed

Thiede, Irene; Thiede, Michael

2015-01-01

This study is the first cost-benefit analysis (CBA) of occupational health and safety (OHS) in a low-income country. It focuses on one of the largest shipbuilding companies in Bangladesh, where globally recognised Occupational Health and Safety Advisory Services (OHSAS) 18001 certification was achieved in 2012. The study examines the relative costs of implementing OHS measures against qualitative and quantifiable benefits of implementation in order to determine whether OHSAS measures are economically advantageous. Quantifying past costs and benefits and discounting future ones, this study looks at the returns of OHS measures at Western Marine Shipbuilding Company Ltd. Costs included investments in workplace and environmental safety, a new clinic that also serves the community, and personal protective equipment (PPE) and training. The results are impressive: previously high injury statistics dropped to close to zero. OHS measures decrease injuries, increase efficiency, and bring income security to workers' families. Certification has proven a competitive edge for the shipyard, resulting in access to greater markets. Intangible benefits such as trust, motivation and security are deemed crucial in the CBA, and this study finds the high investments made are difficult to offset with quantifiable benefits alone.

Figure and Ground in the Visual Cortex: V2 Combines Stereoscopic Cues with Gestalt Rules

PubMed Central

Qiu, Fangtu T.; von der Heydt, Rüdiger

2006-01-01

Figure-ground organization is a process by which the visual system identifies some image regions as foreground and others as background, inferring three-dimensional (3D) layout from 2D displays. A recent study reported that edge responses of neurons in area V2 are selective for side-of-figure, suggesting that figure-ground organization is encoded in the contour signals (border-ownership coding). Here we show that area V2 combines two strategies of computation, one that exploits binocular stereoscopic information for the definition of local depth order, and another that exploits the global configuration of contours (gestalt factors). These are combined in single neurons so that the ‘near’ side of the preferred 3D edge generally coincides with the preferred side-of-figure in 2D displays. Thus, area V2 represents the borders of 2D figures as edges of surfaces, as if the figures were objects in 3D space. Even in 3D displays gestalt factors influence the responses and can enhance or null the stereoscopic depth information. PMID:15996555

The movement ecology and dynamics of plant communities in fragmented landscapes.

PubMed

Damschen, Ellen I; Brudvig, Lars A; Haddad, Nick M; Levey, Douglas J; Orrock, John L; Tewksbury, Joshua J

2008-12-09

A conceptual model of movement ecology has recently been advanced to explain all movement by considering the interaction of four elements: internal state, motion capacity, navigation capacities, and external factors. We modified this framework to generate predictions for species richness dynamics of fragmented plant communities and tested them in experimental landscapes across a 7-year time series. We found that two external factors, dispersal vectors and habitat features, affected species colonization and recolonization in habitat fragments and their effects varied and depended on motion capacity. Bird-dispersed species richness showed connectivity effects that reached an asymptote over time, but no edge effects, whereas wind-dispersed species richness showed steadily accumulating edge and connectivity effects, with no indication of an asymptote. Unassisted species also showed increasing differences caused by connectivity over time, whereas edges had no effect. Our limited use of proxies for movement ecology (e.g., dispersal mode as a proxy for motion capacity) resulted in moderate predictive power for communities and, in some cases, highlighted the importance of a more complete understanding of movement ecology for predicting how landscape conservation actions affect plant community dynamics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Damschen, Ellen I.; Brudvig, Lars A.; Haddad, Nick M.

A conceptual model of movement ecology has recently been advanced to explain all movement by considering the interaction of four elements: internal state, motion capacity, navigation capacities,and external factors. We modified this framework togenerate predictions for species richness dynamics of fragmented plant communities and tested them in experimental landscapes across a 7-year time series. We found that two external factors, dispersal vectors and habitat features, affected species colonization and recolonization in habitat fragments and their effects varied and depended on motion capacity. Bird-dispersed species richness showed connectivity effects that reached an asymptote over time, but no edge effects, whereas wind-dispersedmore » species richness showed steadily accumulating edge and connectivity effects, with no indication of an asymptote. Unassisted species also showed increasing differences caused by connectivity over time,whereas edges had no effect. Our limited use of proxies for movement ecology (e.g., dispersal mode as a proxy for motion capacity) resulted in moderate predictive power for communities and, in some cases, highlighted the importance of a more complete understanding of movement ecology for predicting how landscape conservation actions affect plant community dynamics.« less

Figure and ground in the visual cortex: v2 combines stereoscopic cues with gestalt rules.

PubMed

Qiu, Fangtu T; von der Heydt, Rüdiger

2005-07-07

Figure-ground organization is a process by which the visual system identifies some image regions as foreground and others as background, inferring 3D layout from 2D displays. A recent study reported that edge responses of neurons in area V2 are selective for side-of-figure, suggesting that figure-ground organization is encoded in the contour signals (border ownership coding). Here, we show that area V2 combines two strategies of computation, one that exploits binocular stereoscopic information for the definition of local depth order, and another that exploits the global configuration of contours (Gestalt factors). These are combined in single neurons so that the "near" side of the preferred 3D edge generally coincides with the preferred side-of-figure in 2D displays. Thus, area V2 represents the borders of 2D figures as edges of surfaces, as if the figures were objects in 3D space. Even in 3D displays, Gestalt factors influence the responses and can enhance or null the stereoscopic depth information.

Edge localized mode characteristics during edge localized mode mitigation by supersonic molecular beam injection in Korea Superconducting Tokamak Advanced Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, H. Y.; Hong, J. H.; Jang, J. H.

It has been reported that supersonic molecular beam injection (SMBI) is an effective means of edge localized mode (ELM) mitigation. This paper newly reports the changes in the ELM, plasma profiles, and fluctuation characteristics during ELM mitigation by SMBI in Korea Superconducting Tokamak Advanced Research. During the mitigated ELM phase, the ELM frequency increased by a factor of 2–3 and the ELM size, which was estimated from the D{sub α} amplitude, the fractional changes in the plasma-stored energy and the line-averaged electron density, and divertor heat flux during an ELM burst, decreased by a factor of 0.34–0.43. Reductions in themore » electron and ion temperatures rather than in the electron density were observed during the mitigated ELM phase. In the natural ELM phase, frequency chirping of the plasma fluctuations was observed before the ELM bursts; however, the ELM bursts occurred without changes in the plasma fluctuation frequency in the mitigated ELM phase.« less

RGB-to-RGBG conversion algorithm with adaptive weighting factors based on edge detection and minimal square error.

PubMed

Huang, Chengqiang; Yang, Youchang; Wu, Bo; Yu, Weize

2018-06-01

The sub-pixel arrangement of the RGBG panel and the image with RGB format are different and the algorithm that converts RGB to RGBG is urgently needed to display an image with RGB arrangement on the RGBG panel. However, the information loss is still large although color fringing artifacts are weakened in the published papers that study this conversion. In this paper, an RGB-to-RGBG conversion algorithm with adaptive weighting factors based on edge detection and minimal square error (EDMSE) is proposed. The main points of innovation include the following: (1) the edge detection is first proposed to distinguish image details with serious color fringing artifacts and image details which are prone to be lost in the process of RGB-RGBG conversion; (2) for image details with serious color fringing artifacts, the weighting factor 0.5 is applied to weaken the color fringing artifacts; and (3) for image details that are prone to be lost in the process of RGB-RGBG conversion, a special mechanism to minimize square error is proposed. The experiment shows that the color fringing artifacts are slightly improved by EDMSE, and the values of MSE of the image processed are 19.6% and 7% smaller than those of the image processed by the direct assignment and weighting factor algorithm, respectively. The proposed algorithm is implemented on a field programmable gate array to enable the image display on the RGBG panel.

Patient safety in psychiatric inpatient care: a literature review.

PubMed

Kanerva, A; Lammintakanen, J; Kivinen, T

2013-08-01

Patient safety is widely discussed, but little has been written from the perspective of psychiatric inpatient care, nor on which factors create its patient safety. This paper seeks to understand the concept of patient safety and its intension in psychiatric inpatient care, and to identify factors in organization management, staff and patients' roles which constitute patient safety in such units. A literature search was conducted, and the articles selected were analysed by identifying factors defined to be connected to patient safety and classifying them according to their connection to organization management, staff and patient roles. According to the literature, organization safety culture is present in all aspects of patient safety. Organization management has the main role in patient safety within the organization culture, for example, through leadership, safety practices and creating good working conditions and environment for the staff. Staff's role is influenced by management, but has more individual input in different areas, while the patient's role is more that of an informant so that care can be planned according to the patient's preferences. When developing patient safety it is important to remember the diversity of the concept so that all areas are considered in the developmental work. © 2012 John Wiley & Sons Ltd.

Cross-validation of an employee safety climate model in Malaysia.

PubMed

Bahari, Siti Fatimah; Clarke, Sharon

2013-06-01

Whilst substantial research has investigated the nature of safety climate, and its importance as a leading indicator of organisational safety, much of this research has been conducted with Western industrial samples. The current study focuses on the cross-validation of a safety climate model in the non-Western industrial context of Malaysian manufacturing. The first-order factorial validity of Cheyne et al.'s (1998) [Cheyne, A., Cox, S., Oliver, A., Tomas, J.M., 1998. Modelling safety climate in the prediction of levels of safety activity. Work and Stress, 12(3), 255-271] model was tested, using confirmatory factor analysis, in a Malaysian sample. Results showed that the model fit indices were below accepted levels, indicating that the original Cheyne et al. (1998) safety climate model was not supported. An alternative three-factor model was developed using exploratory factor analysis. Although these findings are not consistent with previously reported cross-validation studies, we argue that previous studies have focused on validation across Western samples, and that the current study demonstrates the need to take account of cultural factors in the development of safety climate models intended for use in non-Western contexts. The results have important implications for the transferability of existing safety climate models across cultures (for example, in global organisations) and highlight the need for future research to examine cross-cultural issues in relation to safety climate. Copyright © 2013 National Safety Council and Elsevier Ltd. All rights reserved.

Attack tolerance of correlated time-varying social networks with well-defined communities

NASA Astrophysics Data System (ADS)

Sur, Souvik; Ganguly, Niloy; Mukherjee, Animesh

2015-02-01

In this paper, we investigate the efficiency and the robustness of information transmission for real-world social networks, modeled as time-varying instances, under targeted attack in shorter time spans. We observe that these quantities are markedly higher than that of the randomized versions of the considered networks. An important factor that drives this efficiency or robustness is the presence of short-time correlations across the network instances which we quantify by a novel metric the-edge emergence factor, denoted as ξ. We find that standard targeted attacks are not effective in collapsing this network structure. Remarkably, if the hourly community structures of the temporal network instances are attacked with the largest size community attacked first, the second largest next and so on, the network soon collapses. This behavior, we show is an outcome of the fact that the edge emergence factor bears a strong positive correlation with the size ordered community structures.

New dual-curvature microlens array with a high fill-factor for organic light emitting diode modules

NASA Astrophysics Data System (ADS)

Lin, Tsung-Hung; Yang, Hsiharng; Chao, Ching-Kong; Shui, Hung-Chi

2013-09-01

A new method for fabricating a novel dual-curvature microlens array with a high fill-factor using proximity printing in a lithography process is reported. The lens shapes include dual-curvature, which is a novel shape composed of triangles and hexagons. We utilized UV proximity printing by controlling a printing gap between the mask and substrate. The designed high density microlens array pattern can fabricate a dual-curvature microlens array with a high fill-factor in a photoresist material. It is due to the UV light diffraction which deflects away from the aperture edges and produces a certain exposure in the photoresist material outside the aperture edges. A dual-curvature microlens array with a height ratio of 0.48 can boost axial luminance up to 22%. Therefore, the novel dual-curvature microlens array offers an economical solution for increasing the luminance of organic light emitting diodes.

Does the concept of safety culture help or hinder systems thinking in safety?

PubMed

Reiman, Teemu; Rollenhagen, Carl

2014-07-01

The concept of safety culture has become established in safety management applications in all major safety-critical domains. The idea that safety culture somehow represents a "systemic view" on safety is seldom explicitly spoken out, but nevertheless seem to linger behind many safety culture discourses. However, in this paper we argue that the "new" contribution to safety management from safety culture never really became integrated with classical engineering principles and concepts. This integration would have been necessary for the development of a more genuine systems-oriented view on safety; e.g. a conception of safety in which human, technological, organisational and cultural factors are understood as mutually interacting elements. Without of this integration, researchers and the users of the various tools and methods associated with safety culture have sometimes fostered a belief that "safety culture" in fact represents such a systemic view about safety. This belief is, however, not backed up by theoretical or empirical evidence. It is true that safety culture, at least in some sense, represents a holistic term-a totality of factors that include human, organisational and technological aspects. However, the departure for such safety culture models is still human and organisational factors rather than technology (or safety) itself. The aim of this paper is to critically review the various uses of the concept of safety culture as representing a systemic view on safety. The article will take a look at the concepts of culture and safety culture based on previous studies, and outlines in more detail the theoretical challenges in safety culture as a systems concept. The paper also presents recommendations on how to make safety culture more systemic. Copyright © 2013 Elsevier Ltd. All rights reserved.

Determinants of safety outcomes and performance: A systematic literature review of research in four high-risk industries.

PubMed

Cornelissen, Pieter A; Van Hoof, Joris J; De Jong, Menno D T

2017-09-01

In spite of increasing governmental and organizational efforts, organizations still struggle to improve the safety of their employees as evidenced by the yearly 2.3 million work-related deaths worldwide. Occupational safety research is scattered and inaccessible, especially for practitioners. Through systematically reviewing the safety literature, this study aims to provide a comprehensive overview of behavioral and circumstantial factors that endanger or support employee safety. A broad search on occupational safety literature using four online bibliographical databases yielded 27.527 articles. Through a systematic reviewing process 176 online articles were identified that met the inclusion criteria (e.g., original peer-reviewed research; conducted in selected high-risk industries; published between 1980-2016). Variables and the nature of their interrelationships (i.e., positive, negative, or nonsignificant) were extracted, and then grouped and classified through a process of bottom-up coding. The results indicate that safety outcomes and performance prevail as dependent research areas, dependent on variables related to management & colleagues, work(place) characteristics & circumstances, employee demographics, climate & culture, and external factors. Consensus was found for five variables related to safety outcomes and seven variables related to performance, while there is debate about 31 other relationships. Last, 21 variables related to safety outcomes and performance appear understudied. The majority of safety research has focused on addressing negative safety outcomes and performance through variables related to others within the organization, the work(place) itself, employee demographics, and-to a lesser extent-climate & culture and external factors. This systematic literature review provides both scientists and safety practitioners an overview of the (under)studied behavioral and circumstantial factors related to occupational safety behavior. Scientists could use this overview to study gaps, and validate or falsify relationships. Safety practitioners could use the insights to evaluate organizational safety policies, and to further development of safety interventions. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

Safety and the Human Factor.

ERIC Educational Resources Information Center

Smith, Ann

1982-01-01

Discusses four elements of safety programs: (1) safety training; (2) safety inspections; (3) accident investigations; and (4) protective safety equipment. Also discusses safety considerations in water/wastewater treatment facilities focusing on falls, drowning hazards, trickling filters, confined space entry, collection/distribution system safety,…

Examining psychosocial and physical hazards in the Ghanaian mining industry and their implications for employees' safety experience.

PubMed

Amponsah-Tawiah, Kwesi; Jain, Aditya; Leka, Stavroula; Hollis, David; Cox, Tom

2013-06-01

In addition to hazardous conditions that are prevalent in mines, there are various physical and psychosocial risk factors that can affect mine workers' safety and health. Without due diligence to mine safety, these risk factors can affect workers' safety experience, in terms of near misses, disabling injuries and accidents experienced or witnessed by workers. This study sets out to examine the effects of physical and psychosocial risk factors on workers' safety experience in a sample of Ghanaian miners. 307 participants from five mining companies responded to a cross sectional survey examining physical and psychosocial hazards and their implications for employees' safety experience. Zero-inflated Poisson regression models indicated that mining conditions, equipment, ambient conditions, support and security, and work demands and control are significant predictors of near misses, disabling injuries, and accidents experienced or witnessed by workers. The type of mine had important implications for workers' safety experience. Copyright © 2013 Elsevier Ltd and National Safety Council. All rights reserved.

A computational parametric study on edge loading in ceramic-on-ceramic total hip joint replacements.

PubMed

Liu, Feng; Feng, Li; Wang, Junyuan

2018-07-01

Edge loading in ceramic-on-ceramic total hip joint replacement is an adverse condition that occurs as the result of a direct contact between the head and the cup rim. It has been associated with translational mismatch in the centres of rotation of the cup and head, and found to cause severe wear and early failure of the implants. Edge loading has been considered in particular in relation to dynamic separation of the cup and head centres during a gait cycle. Research has been carried out both experimentally and computationally to understand the mechanism including the influence of bearing component positioning on the occurrence and severity of edge loading. However, it is experimentally difficult to measure both the load magnitude and duration of edge loading as it occurs as a short impact within the tight space of hip joints. Computationally, a dynamic contact model, for example, developed using the MSC ADAMS software for a multi-body dynamics simulation can be particularly useful for calculating the loads and characterising the edge loading. The aim of the present study was to further develop the computational model, and improve the predictions of contact force and the understanding of mechanism in order to provide guidance on design and surgical factors to avoid or to reduce edge loading and wear. The results have shown that edge loading can be avoided for a low range of translational mismatch in the centres of rotation of the cup and head during gait at the level of approximately 1.0 mm for a cup at 45° inclination, keeping a correct cup inclination at 45° is important to reduce the edge loading severity, and edge loading can be avoided for a certain range of translational mismatch of the cup and head centres with an increased swing phase load. Copyright © 2018 Elsevier Ltd. All rights reserved.

Establishing a culture for patient safety - the role of education.

PubMed

Milligan, Frank J

2007-02-01

This paper argues that the process of making significant moves towards a patient safety culture requires changes in healthcare education. Improvements in patient safety are a shared international priority as too many errors and other forms of unnecessary harm are currently occurring in the process of caring for and treating patients. A description of the patient safety agenda is given followed by a brief analysis of human factors theory and its use in other safety critical industries, most notably aviation. The all too common problem of drug administration errors is used to illustrate the relevance of human factors theory to healthcare education with specific mention made of the Human Factors Analysis and Classification System (HFACS).

Operator performance-enhancing technologies to improve safety. A US DOT safety initiative for meeting the human-centered systems challenge.

DOT National Transportation Integrated Search

1999-11-01

The program implements DOT Human Factors Coordinating Committee (HFCC) recommendations for a coordinated Departmental Human Factors Research Program to advance the human-centered systems approach for enhancing transportation safety. Human error is a ...

75 FR 56972 - Pipeline Safety: Control Room Management/Human Factors

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-17

... DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Parts... Factors AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA); DOT. ACTION: Notice of...: Background There are roughly 170,000 miles of hazardous liquid pipelines, 295,000 miles of gas transmission...

Safety culture assessment in petrochemical industry: a comparative study of two algerian plants.

PubMed

Boughaba, Assia; Hassane, Chabane; Roukia, Ouddai

2014-06-01

To elucidate the relationship between safety culture maturity and safety performance of a particular company. To identify the factors that contribute to a safety culture, a survey questionnaire was created based mainly on the studies of Fernández-Muñiz et al. The survey was randomly distributed to 1000 employees of two oil companies and realized a rate of valid answer of 51%. Minitab 16 software was used and diverse tests, including the descriptive statistical analysis, factor analysis, reliability analysis, mean analysis, and correlation, were used for the analysis of data. Ten factors were extracted using the analysis of factor to represent safety culture and safety performance. The results of this study showed that the managers' commitment, training, incentives, communication, and employee involvement are the priority domains on which it is necessary to stress the effort of improvement, where they had all the descriptive average values lower than 3.0 at the level of Company B. Furthermore, the results also showed that the safety culture influences the safety performance of the company. Therefore, Company A with a good safety culture (the descriptive average values more than 4.0), is more successful than Company B in terms of accident rates. The comparison between the two petrochemical plants of the group Sonatrach confirms these results in which Company A, the managers of which are English and Norwegian, distinguishes itself by the maturity of their safety culture has significantly higher evaluations than the company B, who is constituted of Algerian staff, in terms of safety management practices and safety performance.

Safety Culture Assessment in Petrochemical Industry: A Comparative Study of Two Algerian Plants

PubMed Central

Boughaba, Assia; Hassane, Chabane; Roukia, Ouddai

2014-01-01

Background To elucidate the relationship between safety culture maturity and safety performance of a particular company. Methods To identify the factors that contribute to a safety culture, a survey questionnaire was created based mainly on the studies of Fernández-Muñiz et al. The survey was randomly distributed to 1000 employees of two oil companies and realized a rate of valid answer of 51%. Minitab 16 software was used and diverse tests, including the descriptive statistical analysis, factor analysis, reliability analysis, mean analysis, and correlation, were used for the analysis of data. Ten factors were extracted using the analysis of factor to represent safety culture and safety performance. Results The results of this study showed that the managers' commitment, training, incentives, communication, and employee involvement are the priority domains on which it is necessary to stress the effort of improvement, where they had all the descriptive average values lower than 3.0 at the level of Company B. Furthermore, the results also showed that the safety culture influences the safety performance of the company. Therefore, Company A with a good safety culture (the descriptive average values more than 4.0), is more successful than Company B in terms of accident rates. Conclusion The comparison between the two petrochemical plants of the group Sonatrach confirms these results in which Company A, the managers of which are English and Norwegian, distinguishes itself by the maturity of their safety culture has significantly higher evaluations than the company B, who is constituted of Algerian staff, in terms of safety management practices and safety performance. PMID:25180135

Contrasting physiological responses to excess heat and irradiance in two tropical savanna sedges

PubMed Central

John-Bejai, C.; Farrell, A. D.; Cooper, F. M.; Oatham, M. P.

2013-01-01

Tropical hyperseasonal savannas provide a rare example of a tropical climax community dominated by graminoid species. Species living in such savannas are frequently exposed to excess heat and light, in addition to drought and waterlogging, and must possess traits to avoid or tolerate these stress factors. Here we examine the contrasting heat and light stress adaptations of two dominant savanna sedges: Lagenocarpus guianensis, which is restricted to the sheltered forest edge, and Lagenocarpus rigidus, which extends from the forest edge to the open savanna. An ecotone extending from the forest edge to the open savanna was used to assess differences in a range of physiological traits (efficiency of photosystem II, cell membrane thermostability, stomatal conductance, leaf surface reflectance and canopy temperature depression) and a range of leaf functional traits (length : width ratio, specific leaf area and degree of folding). Lagenocarpus guianensis showed significantly less canopy temperature depression than L. rigidus, which may explain why this species was restricted to the forest edge. The range of leaf temperatures measured was within the thermal tolerance of L. guianensis and allowed photosystem II to function normally, at least within the cool forest edge. The ability of L. rigidus to extend into the open savanna was associated with an ability to decouple leaf temperature from ambient temperature combined with enhanced cell membrane thermostability. The high degree of canopy temperature depression seen in L. rigidus was not explained by enhanced stomatal conductance or leaf reflectance, but was consistent with a capacity to increase specific leaf area and reduce leaf length: width ratio in the open savanna. Plasticity in leaf functional traits and in cell membrane thermostability are key factors in the ability of this savanna sedge to survive abiotic stress. PMID:24379971

Stellar occultation of polarized light from circumstellar electrons. I - Flat envelopes viewed edge on

NASA Technical Reports Server (NTRS)

Brown, John C.; Fox, Geoffrey K.

1989-01-01

The depolarizing and occultation effects of a finite spherical light source on the polarization of light Thomson-scattered from a flat circumstellar envelope seen edge-on are analyzed. The analysis shows that neglect of the finite size of the light source leads to a gross overestimate of the polarization for a given disk geometry. By including occultation and depolarization, it is found that B-star envelopes are necessarily highly flattened disk-type structures. For a disk viewed edge-on, the effect of occultation reduces the polarization more than the inclusion of the depolarization factor alone. Analysis of a one-dimensional plume leads to a powerful technique that permits the electron density distribution to be explicitly obtained from the polarimetric data.

Initial Evaluations of LoC Prediction Algorithms Using the NASA Vertical Motion Simulator

NASA Technical Reports Server (NTRS)

Krishnakumar, Kalmanje; Stepanyan, Vahram; Barlow, Jonathan; Hardy, Gordon; Dorais, Greg; Poolla, Chaitanya; Reardon, Scott; Soloway, Donald

2014-01-01

Flying near the edge of the safe operating envelope is an inherently unsafe proposition. Edge of the envelope here implies that small changes or disturbances in system state or system dynamics can take the system out of the safe envelope in a short time and could result in loss-of-control events. This study evaluated approaches to predicting loss-of-control safety margins as the aircraft gets closer to the edge of the safe operating envelope. The goal of the approach is to provide the pilot aural, visual, and tactile cues focused on maintaining the pilot's control action within predicted loss-of-control boundaries. Our predictive architecture combines quantitative loss-of-control boundaries, an adaptive prediction method to estimate in real-time Markov model parameters and associated stability margins, and a real-time data-based predictive control margins estimation algorithm. The combined architecture is applied to a nonlinear transport class aircraft. Evaluations of various feedback cues using both test and commercial pilots in the NASA Ames Vertical Motion-base Simulator (VMS) were conducted in the summer of 2013. The paper presents results of this evaluation focused on effectiveness of these approaches and the cues in preventing the pilots from entering a loss-of-control event.

Effect of current federal regulations on handgun safety features.

PubMed

Milne, John S; Hargarten, Stephen W; Kellermann, Arthur L; Wintemute, Garen J

2003-01-01

In the late 1960s, the Bureau of Alcohol, Tobacco, and Firearms implemented the "factoring criteria," a set of minimum size and safety standards required for any handgun imported into the United States. These standards, however, were not applied to guns manufactured domestically. We determine whether extending the factoring criteria to all handguns sold in the United States, as has been proposed in Congress, would increase the likelihood that safety devices would be included in new handgun designs. Imported and domestic handgun models produced in 1996 were examined to determine the prevalence of 4 passively acting safety devices on pistols and 1 passive safety device on revolvers. Domestic models were also scored against the factoring criteria. Compared with domestic pistol models, imported pistols were more likely to include a firing pin block (odds ratio [OR] 2.43; 95% confidence interval [CI] 1.54 to 3.85) and a loaded chamber indicator (OR 1.59; 95% CI 0.98 to 2.56). Domestic pistol models that already met the factoring criteria were more likely to include a loaded chamber indicator (OR 12.05; 95% CI 2.74 to 53.02), a grip safety (OR 24.12; 95% CI 7.8 to 74.33), and a firing pin block (OR 4.92; 95% CI 2.35 to 10.29) than domestic models that did not meet the criteria. Although pistol models that meet the factoring criteria are more likely to contain safety devices than those that do not, the net effect is modest. Thus, the factoring criteria alone are insufficient to ensure consistent incorporation of safety features into new handgun designs.

Scientific basis for risk analysis of food-related substances with particular reference to health effects on children.

PubMed

Hayashi, Yuzo

2009-01-01

Based on the advance of toxicology and related sciences, a regulatory regime for the safety of chemicals related to daily life has been rapidly established. Especially for the food-related substances, the process of risk analysis has facilitated the collaboration by all the players including consumers toward the security of their safety. On the other hand, except for pharmaceuticals, science-based decisions and governmental actions on safety issues have not always gained confidence of the public. One of the reasons was the inadequacy in the way of use of scientific knowledge, or in other words, inappropriateness of decision making by "the regulatory science". Regulatory science is a science to warrant the decision making processes for governmental acts (Mitsuru Uchiyama). In the case of chemical safety, it can be redefined as a theoretical concept to complements the uncertainty of scientific knowledge for the decision of governmental acts that is adequate in both scientific and social ways. Therefore, the regulatory science is an indispensable discipline to effectively apply risk analysis. Here, the significance of the regulatory science for the hazard assessment of the chemicals, especially for children is described. In the past, the hazard effects of chemicals have been assessed for adults. Recently, however, the importance of the assessment for children has gained international emphases. Not only for pharmaceuticals, but for food-related substances, the acceptable daily intake (ADI) and tolerable daily intake (TDI) are often set differently for adults and children. The child-specific responses against chemicals are related not only to the physiological factors such as body weight, basal metabolism, but also rapid growth of the body with developmental status of various organs. General knowledge on these issues will be discussed mainly referring the World Health Organization (WHO) documents. Although the cutting edge technology backs up the development of toxicology, it would appear that it is reaching a turning point from technology-centrism to look toward the direction for contribution to society from the stand point of regulatory science.

14 CFR 23.619 - Special factors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Special factors. 23.619 Section 23.619... Special factors. The factor of safety prescribed in § 23.303 must be multiplied by the highest pertinent special factors of safety prescribed in §§ 23.621 through 23.625 for each part of the structure whose...

Seismic verification of nuclear plant equipment anchorage, Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Czarnecki, R M

1991-06-01

Guidelines have been developed to evaluate the seismic adequacy of the anchorage of various classes of electrical and mechanical equipment in nuclear power plants covered by NRC Unresolved Safety Issue A-46. The guidelines consist of anchorage strength capacities as a function of key equipment and installation parameters. The strength criteria for expansion anchor bolts were developed by collecting and analyzing a large quantity of test data. The strength criteria for Cast-in-Place bolts and welds to embedded steel plates and channels were taken from existing nuclear-industry design guidelines. For anchorage used in low strength concrete and in concrete with cracks, appropriatemore » strength reduction factors were developed. Reduction factors for parameters such as edge distance, spacing and embedment depth are also included. Based on the anchorage capacity and equipment configuration, inspection checklists for field verification of anchorage adequacy were developed, and provisions for outliners that can be used to further investigate anchorages that cannot be verified in the field were prepared. The screening tables are based on an analysis of the anchorage forces developed by common equipment types and on strength criteria to quantify the holding power of anchor bolts and welds. A computer code EBAC was developed for the evaluation of the adequacy of the equipment anchorage. Guidelines to evaluate anchorage adequacy for vertical and horizontal tanks and horizontal heat exchangers were also developed.« less

Assessment of safety culture among job positions in high-rise construction: a hybrid fuzzy multi criteria decision-making (FMCDM) approach.

PubMed

Ardeshir, A; Mohajeri, M

2018-06-01

The construction industry is known as one of the most dangerous industries, which not only requires sound operation of executive laws and regulations, but also necessitates the safety culture of all workers at workshops. Therefore, the aim of this research is to identify the factors of safety culture and ranking occupations in jobsites based on those factors in order to proactively improve the safety culture of construction projects and subsequently promote safety conditions and worksites. In this study, safety culture criteria are weighted by a combination of Fuzzy Decision Trail and Evaluation Laboratory and Fuzzy ANP methods. Next, different job positions in high-rise projects are ranked using the Fuzzy Technique for Order of Preference by Similarity to Ideal Solution method. Findings demonstrated that the project manager, site superintendent and supervisor occupations had the highest and labourers had the lowest level of safety culture in the high-rise construction industry. Furthermore, factors such as safety supervision and training must be considered more seriously in order to create a positive safety culture among workers.

Take a Seat.

ERIC Educational Resources Information Center

Grant, Deborah R.

1999-01-01

Examines the factors involved in purchasing school furnishings that will help ensure its long-time use, safety, and ability to resist abuse. Cost and safety factors discussed include resisting trendy colors to reduce cost in furniture matching, managing computer and office wiring for safety, considering ergonomics in the purchasing decision, and…

Listening to food workers: Factors that impact proper health and hygiene practice in food service.

PubMed

Clayton, Megan L; Clegg Smith, Katherine; Neff, Roni A; Pollack, Keshia M; Ensminger, Margaret

2015-01-01

Foodborne disease is a significant problem worldwide. Research exploring sources of outbreaks indicates a pronounced role for food workers' improper health and hygiene practice. To investigate food workers' perceptions of factors that impact proper food safety practice. Interviews with food service workers in Baltimore, MD, USA discussing food safety practices and factors that impact implementation in the workplace. A social ecological model organizes multiple levels of influence on health and hygiene behavior. Issues raised by interviewees include factors across the five levels of the social ecological model, and confirm findings from previous work. Interviews also reveal many factors not highlighted in prior work, including issues with food service policies and procedures, working conditions (e.g., pay and benefits), community resources, and state and federal policies. Food safety interventions should adopt an ecological orientation that accounts for factors at multiple levels, including workers' social and structural context, that impact food safety practice.

Bilateral effects of hospital patient-safety procedures on nurses' job satisfaction.

PubMed

Inoue, T; Karima, R; Harada, K

2017-09-01

The aim of this study was to examine how hospital patient-safety procedures affect the job satisfaction of hospital nurses. Additionally, we investigated the association between perceived autonomy and hospital patient-safety procedures and job satisfaction. Recently, measures for patient safety have been recognized as an essential requirement in hospitals. Hospital patient-safety procedures may enhance the job satisfaction of nurses by improving the quality of their work. However, such procedures may also decrease their job satisfaction by imposing excessive stress on nurses because they cannot make mistakes. The participants included 537 nurses at 10 private hospitals in Japan (The surveys were collected from March to July 2012). Factors related to hospital patient-safety procedures were demonstrated using factor analysis, and the associations between these factors and nurses' self-perceived autonomy and job satisfaction were examined using structural equation modelling. Five factors regarding hospital patient-safety procedures were extracted. Additionally, structural equation modelling revealed statistically significant associations between these factors and the nurses' self-perceived autonomy and job satisfaction. The findings showed that nurses' perceived autonomy of the workplace enhanced their job satisfaction and that their perceptions of hospital patient-safety procedures promoted their job satisfaction. However, some styles of chief nurses' leadership regarding patient safety restrict nurses' independent and autonomous decision-making and actions, resulting in a lowering of job satisfaction. This study demonstrated that hospital patient-safety procedures have ambiguous effects on nurses' job satisfaction. In particular, chief nurses' leadership relating to patient safety can have a positive or negative effect on nurses' job satisfaction. The findings indicated that hospital managers should demonstrate positive attitudes to improve patient safety for nurses' job satisfaction. In addition, policymakers in the hospitals should consider that chief nurses' leadership styles may reduce autonomy and suppress nurses' job satisfaction. © 2017 The Authors International Nursing Review published by John Wiley & Sons Ltd on behalf of International Council of Nurses.

Evaluating and defining the sharpness of intraocular lenses: microedge structure of commercially available square-edged hydrophobic lenses.

PubMed

Werner, Liliana; Müller, Matthias; Tetz, Manfred

2008-02-01

To evaluate the microstructure of the edges of currently available square-edged hydrophobic intraocular lenses (IOLs) in terms of their deviation from an ideal square. Berlin Eye Research Institute, Berlin, Germany. Sixteen designs of hydrophobic acrylic or silicone IOLs were studied. For each design, a +20.0 diopter (D) IOL and a +0.0 D IOL (or the lowest available plus dioptric power) were evaluated. The IOL edge was imaged under high-magnification scanning electron microscopy using a standardized technique. The area above the lateral-posterior edge, representing the deviation from a perfect square, was measured in square microns using reference circles of 40 microm and 60 microm of radius and the AutoCAD LT 2000 system (Autodesk). The IOLs were compared with an experimental square-edged poly(methyl methacrylate) (PMMA) IOL (reference IOL) with an edge design that effectively stopped lens epithelial cell growth in culture in a preliminary study. Two round-edged silicone IOLs were used as controls. The hydrophobic IOLs used, labeled as square-edged IOLs, had an area of deviation from a perfect square ranging from 4.8 to 338.4 microm(2) (40 microm radius reference circle) and from 0.2 to 524.4 microm(2) (60 microm radius circle). The deviation area for the square-edged PMMA IOL was 34.0 microm(2) with a 40 microm radius circle and 37.5 microm(2) with a 60 microm radius circle. The respective values for the +20.0 D control silicone IOL were 729.3 microm(2) and 1525.3 microm(2) and for the +0.0 D control silicone IOL, 727.3 microm(2) and 1512.7 microm(2). Seven silicone IOLs of 5 designs had area values that were close to those of the reference square-edged PMMA IOL. Several differences in edge finishing between the IOLs analyzed were also observed. There was a large variation in the deviation area from a perfect square as well as in the edge finishing, not only between different IOL designs but also between different powers of the same design. Clinically, factors such as the shrink-wrapping of the IOL by the capsule may even out or modify the influence of these variations in terms of preventing posterior capsule opacification.

Computing factors of safety against wind-induced tree stem damage.

PubMed

Niklas, K J

2000-04-01

The drag forces, bending moments and stresses acting on stems differing in size and location within the mechanical infrastructure of a large wild cherry (Prunus serotina Ehrh.) tree are estimated and used to calculate the factor of safety against wind-induced mechanical failure based on the mean breaking stress of intact stems and samples of wood drawn from this tree. The drag forces acting on stems are calculated based on stem projected areas and field measurements of wind speed taken within the canopy and along the length of the trunk. The bending moments and stresses resulting from these forces are shown to increase basipetally in a nearly log-log linear fashion toward the base of the tree. The factor of safety, however, varies in a sinusoidal manner such that the most distal stems have the highest factors of safety, whereas stems of intermediate location and portions of the trunk near ground level have equivalent and much lower factors of safety. This pattern of variation is interpreted to indicate that, as a course of normal growth and development, trees similar to the one examined in this study maintain a cadre of stems prone to wind-induced mechanical damage that can reduce the probability of catastrophic tree failure by reducing the drag forces acting on older portions of the tree. Comparisons among real and hypothetical stems with different taper experiencing different vertical wind speed profiles show that geometrically self-similar stems have larger factors of safety than stems tapering according to elastic or stress self-similarity, and that safety factors are less significantly influenced by the 'geometry' of the wind-profile.

Fermi-Edge Singularity of Spin-Polarized Electrons

NASA Astrophysics Data System (ADS)

Plochocka-Polack, P.; Groshaus, J. G.; Rappaport, M.; Umansky, V.; Gallais, Y.; Pinczuk, A.; Bar-Joseph, I.

2007-05-01

We study the absorption spectrum of a two-dimensional electron gas (2DEG) in a magnetic field. We find that at low temperatures, when the 2DEG is spin polarized, the absorption spectra, which correspond to the creation of spin up or spin down electrons, differ in magnitude, linewidth, and filling factor dependence. We show that these differences can be explained as resulting from the creation of a Mahan exciton in one case, and of a power law Fermi-edge singularity in the other.

Factors Influencing the Accuracy of Aerodynamic Hinge-Moment Prediction

DTIC Science & Technology

1978-08-01

condition on the aft lifting surfaces and flaps. A new modeling technique for trailing-edge wake analysis using a potential- flow program based on the...control surface as depicLed in figure 21.. Three different models are used to simulate the flow on the wing, the flap, and the gaps. In the first two panel...ized sense, similar to that implemented in the FLEXSTAB program. The modeling of the wake on the side-edge gaps differs in the first two panel models

A multi-agent safety response model in the construction industry.

PubMed

Meliá, José L

2015-01-01

The construction industry is one of the sectors with the highest accident rates and the most serious accidents. A multi-agent safety response approach allows a useful diagnostic tool in order to understand factors affecting risk and accidents. The special features of the construction sector can influence the relationships among safety responses along the model of safety influences. The purpose of this paper is to test a model explaining risk and work-related accidents in the construction industry as a result of the safety responses of the organization, the supervisors, the co-workers and the worker. 374 construction employees belonging to 64 small Spanish construction companies working for two main companies participated in the study. Safety responses were measured using a 45-item Likert-type questionnaire. The structure of the measure was analyzed using factor analysis and the model of effects was tested using a structural equation model. Factor analysis clearly identifies the multi-agent safety dimensions hypothesized. The proposed safety response model of work-related accidents, involving construction specific results, showed a good fit. The multi-agent safety response approach to safety climate is a useful framework for the assessment of organizational and behavioral risks in construction.

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

PubMed

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.

Factors affecting songbird nest survival in riparian forests in a Midwestern agricultural landscape

Treesearch

Rebecca G. Peak; Frank R. Thompson; Terry L. Shaffer

2004-01-01

We investigated factors affecting nest success of songbirds in riparian forest and buffers in northeastern Missouri. We used an information-theoretic approach to determine support for hypotheses concerning effects of nest-site, habitat-patch, edge, and temporal factors on nest success of songbirds in three narrow (55-95 m) and three wide (400-530 m) riparian forests...

Patient Safety: The Role of Human Factors and Systems Engineering

PubMed Central

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

Sociotechnical attributes of safe and unsafe work systems.

PubMed

Kleiner, Brian M; Hettinger, Lawrence J; DeJoy, David M; Huang, Yuang-Hsiang; Love, Peter E D

2015-01-01

Theoretical and practical approaches to safety based on sociotechnical systems principles place heavy emphasis on the intersections between social-organisational and technical-work process factors. Within this perspective, work system design emphasises factors such as the joint optimisation of social and technical processes, a focus on reliable human-system performance and safety metrics as design and analysis criteria, the maintenance of a realistic and consistent set of safety objectives and policies, and regular access to the expertise and input of workers. We discuss three current approaches to the analysis and design of complex sociotechnical systems: human-systems integration, macroergonomics and safety climate. Each approach emphasises key sociotechnical systems themes, and each prescribes a more holistic perspective on work systems than do traditional theories and methods. We contrast these perspectives with historical precedents such as system safety and traditional human factors and ergonomics, and describe potential future directions for their application in research and practice. The identification of factors that can reliably distinguish between safe and unsafe work systems is an important concern for ergonomists and other safety professionals. This paper presents a variety of sociotechnical systems perspectives on intersections between social--organisational and technology--work process factors as they impact work system analysis, design and operation.

Emotional Safety in Adventure Therapy Programs: Can It Be Defined?

ERIC Educational Resources Information Center

Vincent, Suzanne M.

1995-01-01

Ninety-eight adventure therapy professionals analyzed a proposed definition of emotional safety and rated 26 factors hypothesized to affect an individual's level of emotional safety during adventure activities. Factors were related to specific techniques used by instructors, instructor skills and abilities, the physical environment, and group…

Mission Safety Evaluation Report for STS-43, Postflight Edition

NASA Technical Reports Server (NTRS)

Hill, William C.; Finkel, Seymour I.

1991-01-01

Some of the topics covered include: (1) an STS-43 mission summary; (2) safety risks factors/issues; (3) resolved STS-43 safety risk factors; (4) STS-40 inflight anomalies; (5) STS-37 inflight anomalies; and (6) STS-43 inflight anomalies. Background information and a list of acronyms are also presented.

Mission Safety Evaluation Report for STS-32, Postflight Edition

NASA Technical Reports Server (NTRS)

Hill, William C.; Finkel, Seymour I.

1990-01-01

The topics covered include: (1) an STS-32 mission summary; (2) safety risk factors/issues; (3) resolved STS-32 safety risk factors; (4) STS-32 inflight anomalies; (5) STS-28 inflight anomalies; and (6) STS-32 inflight anomalies. Background information and a list of acronyms are also presented.

16 CFR 1119.4 - Factors considered in determining civil penalties.

Code of Federal Regulations, 2011 CFR

2011-01-01

... penalties. 1119.4 Section 1119.4 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS CIVIL PENALTY FACTORS § 1119.4 Factors considered in determining civil penalties...) of the FFA, specify factors considered by the Commission in determining the amount of a civil penalty...

16 CFR 1119.4 - Factors considered in determining civil penalties.

Code of Federal Regulations, 2012 CFR

2012-01-01

... penalties. 1119.4 Section 1119.4 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS CIVIL PENALTY FACTORS § 1119.4 Factors considered in determining civil penalties...) of the FFA, specify factors considered by the Commission in determining the amount of a civil penalty...

16 CFR 1119.4 - Factors considered in determining civil penalties.

Code of Federal Regulations, 2014 CFR

2014-01-01

... penalties. 1119.4 Section 1119.4 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY ACT REGULATIONS CIVIL PENALTY FACTORS § 1119.4 Factors considered in determining civil penalties...) of the FFA, specify factors considered by the Commission in determining the amount of a civil penalty...

Abiotic factors influencing deer browsing in West Virginia

Treesearch

Tyler A. Campbell; Benjamin R. Laseter; W. Mark Ford; Richard H. Odom; Karl V. Miller

2006-01-01

We present a comparison of woody browse availability and white-tailed deer (Odocoileus virginianus) use among clearcut interiors, skidder trail edges, and mature forest and an evaluation of the relative importance of aboitic factors in predicting browsing pressure within regenerating clearcuts in the central Appalachians of West Virginia. We sampled...

Concrete Instantiations of Mathematics: A Double-Edged Sword

ERIC Educational Resources Information Center

Kaminski, Jennifer A.; Sloutsky, Vladimir M.; Heckler, Andrew F.

2009-01-01

What factors affect transfer of knowledge is a complex question. In recent research, the authors demonstrated that concreteness of the learning domain is one such factor (Kaminski, Sloutsky, & Heckler, 2008). Even when prompted and given no time delay, participants who learned a concrete instantiation of a mathematical concept failed to…

Built-up edge investigation in vibration drilling of Al2024-T6.

PubMed

Barani, A; Amini, S; Paktinat, H; Fadaei Tehrani, A

2014-07-01

Adding ultrasonic vibrations to drilling process results in an advanced hybrid machining process, entitled "vibration drilling". This study presents the design and fabrication of a vibration drilling tool by which both rotary and vibrating motions are applied to drill simultaneously. High frequency and low amplitude vibrations were generated by an ultrasonic transducer with frequency of 19.65 kHz. Ultrasonic transducer was controlled by a MPI ultrasonic generator with 3 kW power. The drilling tool and workpiece material were HSS two-flute twist drill and Al2024-T6, respectively. The aim of this study was investigating on the effect of ultrasonic vibrations on built-up edge, surface quality, chip morphology and wear mechanisms of drill edges. Therefore, these factors were studied in both vibration and ordinary drilling. Based on the achieved results, vibration drilling offers less built-up edge and better surface quality compared to ordinary drilling. Copyright © 2014 Elsevier B.V. All rights reserved.

Resolution factors in edgeline holography.

PubMed

Trolinger, J D; Gee, T H

1971-06-01

When an in-line Fresnel hologram of an object such as a projectile in flight is made, the reconstruction comprises an image of the outside edge of the object superimposed upon a Fresnel diffraction pattern of the edge and an unmodulated portion of the reconstruction beam. When the reconstructed image is bandpass filtered, the only remaining significant contribution is that of a diffraction pattern which is symmetrical about an edgeline gaussian image of the object. The present paper discusses the application of this type of holography in accurately locating the edge of a large dynamic object, the position of which is not accurately known in any dimension. A theoretical and experimental analysis was performed to study the effects of motion, hologram size, film type, and practical limitations upon the attainable resolution in the reconstructed image. The bandlimiting effect of motion is used to relate the motion effected resolution limit of holography to that of photography. The study shows that an edgeline can be accurately located even at high velocity normal to the edge.

The relationship between employees' perceptions of safety and organizational culture.

PubMed

O'Toole, Michael

2002-01-01

With limited resources to help reduce occupational injuries, companies struggle with how to best focus these resources to achieve the greatest reduction in injuries for the optimal cost. Safety culture has been identified as a critical factor that sets the tone for importance of safety within an organization. An employee safety perception survey was conducted, and injury data were collected over a 45-month period from a large ready-mix concrete producer located in the southwest region of the United States. The results of this preliminary study suggest that the reductions in injuries experienced at the company locations was strongly impacted by the positive employee perceptions on several key factors. Management's commitment to safety was the factor with the greatest positive perception by employees taking the survey. This study was set up as a pilot project and did not unitize an experimental design. That weakness reduces the strength of these findings but adds to the importance of expanding the pilot project with an appropriate experimental design. Management leadership has been identified, along with several other factors, to influence employee perceptions of the safety management system. Those perceptions, in turn, appear to influence employee decisions that relate to at-risk behaviors and decisions on the job. The results suggest that employee perceptions of the safety system are related to management's commitment to safety, which, in turn, appear to be related to injury rates. Management should focus on how to best leverage these key factors to more positively impact injury rates within their companies.

Workforce perceptions of hospital safety culture: development and validation of the patient safety climate in healthcare organizations survey.

PubMed

Singer, Sara; Meterko, Mark; Baker, Laurence; Gaba, David; Falwell, Alyson; Rosen, Amy

2007-10-01

To describe the development of an instrument for assessing workforce perceptions of hospital safety culture and to assess its reliability and validity. Primary data collected between March 2004 and May 2005. Personnel from 105 U.S. hospitals completed a 38-item paper and pencil survey. We received 21,496 completed questionnaires, representing a 51 percent response rate. Based on review of existing safety climate surveys, we developed a list of key topics pertinent to maintaining a culture of safety in high-reliability organizations. We developed a draft questionnaire to address these topics and pilot tested it in four preliminary studies of hospital personnel. We modified the questionnaire based on experience and respondent feedback, and distributed the revised version to 42,249 hospital workers. We randomly divided respondents into derivation and validation samples. We applied exploratory factor analysis to responses in the derivation sample. We used those results to create scales in the validation sample, which we subjected to multitrait analysis (MTA). We identified nine constructs, three organizational factors, two unit factors, three individual factors, and one additional factor. Constructs demonstrated substantial convergent and discriminant validity in the MTA. Cronbach's alpha coefficients ranged from 0.50 to 0.89. It is possible to measure key salient features of hospital safety climate using a valid and reliable 38-item survey and appropriate hospital sample sizes. This instrument may be used in further studies to better understand the impact of safety climate on patient safety outcomes.

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

PubMed

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.

Three-dimensional scrape off layer transport in the helically symmetric experiment HSX

NASA Astrophysics Data System (ADS)

Akerson, A. R.; Bader, A.; Hegna, C. C.; Schmitz, O.; Stephey, L. A.; Anderson, D. T.; Anderson, F. S. B.; Likin, K. M.

2016-08-01

The edge topology of helically symmetric experiment (HSX) in the quasi-helically symmetric configuration is characterized by an 8/7 magnetic island remnant embedded in a short connection length scrape-off layer (SOL) domain. A 2D mapping of edge plasma profiles within this heterogeneous SOL has been constructed using a movable, multi-pin Langmuir probe. Comparisons of these measurements to edge simulations using the EMC3-EIRENE 3D plasma fluid and kinetic neutral gas transport model have been performed. The measurements provide strong evidence that particle transport is diffusive within the island region and dominantly convective in the SOL region. Measurements indicate that phenomenological cross-field diffusion coefficients are low in the SOL region between the last closed flux surface and edge island (i.e. {{D}\\bot}≈ 0.03 m2 s-1). This level of transport was found to increase by a factor of two when a limiter is inserted almost completely into the magnetic island. A reduction in gradients of the edge electrostatic plasma potential was also measured in this configuration, suggesting that the reduced electric field may be linked to the increased cross-field transport observed.

Modifying the Interface Edge to Control the Electrical Transport Properties of Nanocontacts to Nanowires.

PubMed

Lord, Alex M; Ramasse, Quentin M; Kepaptsoglou, Despoina M; Evans, Jonathan E; Davies, Philip R; Ward, Michael B; Wilks, Steve P

2017-02-08

Selecting the electrical properties of nanomaterials is essential if their potential as manufacturable devices is to be reached. Here, we show that the addition or removal of native semiconductor material at the edge of a nanocontact can be used to determine the electrical transport properties of metal-nanowire interfaces. While the transport properties of as-grown Au nanocatalyst contacts to semiconductor nanowires are well-studied, there are few techniques that have been explored to modify the electrical behavior. In this work, we use an iterative analytical process that directly correlates multiprobe transport measurements with subsequent aberration-corrected scanning transmission electron microscopy to study the effects of chemical processes that create structural changes at the contact interface edge. A strong metal-support interaction that encapsulates the Au nanocontacts over time, adding ZnO material to the edge region, gives rise to ohmic transport behavior due to the enhanced quantum-mechanical tunneling path. Removal of the extraneous material at the Au-nanowire interface eliminates the edge-tunneling path, producing a range of transport behavior that is dependent on the final interface quality. These results demonstrate chemically driven processes that can be factored into nanowire-device design to select the final properties.

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

PubMed Central

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

2017-01-01

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. PMID:29278242

Modeling the impact of spatial relationships on horizontal curve safety.

PubMed

Findley, Daniel J; Hummer, Joseph E; Rasdorf, William; Zegeer, Charles V; Fowler, Tyler J

2012-03-01

The curved segments of roadways are more hazardous because of the additional centripetalforces exerted on a vehicle, driver expectations, and other factors. The safety of a curve is dependent on various factors, most notably by geometric factors, but the location of a curve in relation to other curves is also thought to influence the safety of those curves because of a driver's expectation to encounter additional curves. The link between an individual curve's geometric characteristics and its safety performance has been established, but spatial considerations are typically not included in a safety analysis. The spatial considerations included in this research consisted of four components: distance to adjacent curves, direction of turn of the adjacent curves, and radius and length of the adjacent curves. The primary objective of this paper is to quantify the spatial relationship between adjacent horizontal curves and horizontal curve safety using a crash modification factor. Doing so enables a safety professional to more accurately estimate safety to allocate funding to reduce or prevent future collisions and more efficiently design new roadway sections to minimize crash risk where there will be a series of curves along a route. The most important finding from this research is the statistical significance of spatial considerations for the prediction of horizontal curve safety. The distances to adjacent curves were found to be a reliable predictor of observed collisions. This research recommends a model which utilizes spatial considerations for horizontal curve safety prediction in addition to current Highway Safety Manual prediction capabilities using individual curve geometric features. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dynamic Deformation of Theatrical Flats

NASA Astrophysics Data System (ADS)

Walton, Jamiahus; Martell, Eric; Martell, Verda

2013-03-01

In theatre, flats are used as walls and background scenery. During construction, flats are often built on the ground and then ``walked up,'' where a group of stagehands manually lift one end while another anchors the other end in place. When flats are very large, they can deform during this process. Stiffeners are used to decrease the amount of deformation in the flat. The purpose of this research is to determine the strain along the flat during the process of raising it up with and without stiffeners. We will also explore the effect of the person anchoring the pivot edge of the flat and discuss the safety concerns this presents. This research is part of the Physics of Theatre Project, an interdisciplinary collaboration designed to improve safety, reduce costs, and increase knowledge of physics principles within the technical theatre community.

Dual band multi frequency rectangular patch microstrip antenna with flyswatter shaped slot for wireless systems

NASA Astrophysics Data System (ADS)

Bhardwaj, Dheeraj; Saraswat, Shriti; Gulati, Gitansh; Shekhar, Snehanshu; Joshi, Kanika; Sharma, Komal

2016-03-01

In this paper a dual band planar antenna has been proposed for IEEE 802.16 Wi-MAX /IEEE 802.11 WLAN/4.9 GHz public safety applications. The antenna comprises a frequency bandwidth of 560MHz (3.37GHz-3.93GHz) for WLAN and WiMAX and 372MHz (4.82GHz-5.192GHz) for 4.9 GHz public safety applications and Radio astronomy services (4.8-4.94 GHz). The proposed antenna constitutes of a single microstrip patch reactively loaded with three identical steps positioned in a zig-zag manner towards the radiating edges of the patch. The coaxially fed patch antenna characteristics (radiation pattern, antenna gain, antenna directivity, current distribution, S11) have been investigated. The antenna design is primarily focused on achieving a dual band operation.

Flow and performance of an air-curtain biological safety cabinet.

PubMed

Huang, Rong Fung; Chou, Chun I

2009-06-01

Using laser-assisted smoke flow visualization and tracer gas concentration detection techniques, this study examines aerodynamic flow properties and the characteristics of escape from containment, inward dispersion, and cross-cabinet contamination of a biological safety cabinet installed with an air curtain across the front aperture. The experimental method partially simulates the NSF/ANSI 49 standards with the difference that the biological tracer recommended by these standards is replaced by a mixture of 10% SF(6) in N(2). The air curtain is set up across the cabinet aperture plane by means of a narrow planar jet issued from the lower edge of the sash and a suction flow going through a suction slot installed at the front edge of the work surface. Varying the combination of jet velocity, suction flow velocity, and descending flow velocity reveals three types of characteristic flow modes: 'straight curtain', 'slightly concave curtain', and 'severely concave curtain'. Operating the cabinet in the straight curtain mode causes the air curtain to impinge on the doorsill and therefore induces serious escape from containment. In the severely concave curtain mode, drastically large inward dispersion and cross-cabinet contamination were observed because environmental air entered into the cabinet and a three-dimensional vortical flow structure formed in the cabinet. The slightly concave curtain mode presents a smooth and two-dimensional flow pattern with an air curtain separating the outside atmosphere from the inside space of the cabinet, and therefore exhibited negligibly small escape from containment, inward dispersion, and cross-cabinet contamination.

Photon counting x-ray imaging with K-edge filtered x-rays: A simulation study.

PubMed

Atak, Haluk; Shikhaliev, Polad M

2016-03-01

In photon counting (PC) x-ray imaging and computed tomography (CT), the broad x-ray spectrum can be split into two parts using an x-ray filter with appropriate K-edge energy, which can improve material decomposition. Recent experimental study has demonstrated substantial improvement in material decomposition with PC CT when K-edge filtered x-rays were used. The purpose of the current work was to conduct further investigations of the K-edge filtration method using comprehensive simulation studies. The study was performed in the following aspects: (1) optimization of the K-edge filter for a particular imaging configuration, (2) effects of the K-edge filter parameters on material decomposition, (3) trade-off between the energy bin separation, tube load, and beam quality with K-edge filter, (4) image quality of general (unsubtracted) images when a K-edge filter is used to improve dual energy (DE) subtracted images, and (5) improvements with K-edge filtered x-rays when PC detector has limited energy resolution. The PC x-ray images of soft tissue phantoms with 15 and 30 cm thicknesses including iodine, CaCO3, and soft tissue contrast materials, were simulated. The signal to noise ratio (SNR) of the contrast elements was determined in general and material-decomposed images using K-edge filters with different atomic numbers and thicknesses. The effect of the filter atomic number and filter thickness on energy separation factor and SNR was determined. The boundary conditions for the tube load and halfvalue layer were determined when the K-edge filters are used. The material-decomposed images were also simulated using PC detector with limited energy resolution, and improvements with K-edge filtered x-rays were quantified. The K-edge filters with atomic numbers from 56 to 71 and K-edge energies 37.4-63.4 keV, respectively, can be used for tube voltages from 60 to 150 kVp, respectively. For a particular tube voltage of 120 kVp, the Gd and Ho were the optimal filter materials to achieve highest SNR. For a particular K-edge filter of Gd and tube voltage of 120 kVp, the filter thickness 0.6 mm provided maximum SNR for considered imaging applications. While K-edge filtration improved SNR of CaCO3 and iodine by 41% and 36%, respectively, in DE subtracted images, it did not deteriorate SNR in general images. For x-ray imaging with nonideal PC detector, the positive effect of the K-edge filter was increased when FWHM energy resolution was degraded, and maximum improvement was at 60% FWHM. This study has shown that K-edge filtered x-rays can provide substantial improvements of material selective PC x-ray and CT imaging for nearly all imaging applications using 60-150 kVp tube voltages. Potential limitations such as tube load, beam hardening, and availability of filter material were shown to not be critical.

Quantitative measurement of eyestrain on 3D stereoscopic display considering the eye foveation model and edge information.

PubMed

Heo, Hwan; Lee, Won Oh; Shin, Kwang Yong; Park, Kang Ryoung

2014-05-15

We propose a new method for measuring the degree of eyestrain on 3D stereoscopic displays using a glasses-type of eye tracking device. Our study is novel in the following four ways: first, the circular area where a user's gaze position exists is defined based on the calculated gaze position and gaze estimation error. Within this circular area, the position where edge strength is maximized can be detected, and we determine this position as the gaze position that has a higher probability of being the correct one. Based on this gaze point, the eye foveation model is defined. Second, we quantitatively evaluate the correlation between the degree of eyestrain and the causal factors of visual fatigue, such as the degree of change of stereoscopic disparity (CSD), stereoscopic disparity (SD), frame cancellation effect (FCE), and edge component (EC) of the 3D stereoscopic display using the eye foveation model. Third, by comparing the eyestrain in conventional 3D video and experimental 3D sample video, we analyze the characteristics of eyestrain according to various factors and types of 3D video. Fourth, by comparing the eyestrain with or without the compensation of eye saccades movement in 3D video, we analyze the characteristics of eyestrain according to the types of eye movements in 3D video. Experimental results show that the degree of CSD causes more eyestrain than other factors.

Traffic safety in the U.S.: re-examining major opportunities.

PubMed

Sivak, Michael; Luoma, Juha; Flannagan, Michael J; Bingham, C Raymond; Eby, David W; Shope, Jean T

2007-01-01

This article examines five major road-safety risk factors: exceeding posted speed limits, not using safety belts, driving while intoxicated, nighttime driving, and young drivers. The importance of each of these factors is documented, known effective countermeasures (both policy and technology based) are discussed, and impediments to the implementation of these countermeasures in the United States are examined. Based on current understanding of the five major risk factors, and of the available countermeasures, there appear to be a variety of opportunities to make substantial gains in road safety using existing knowledge. The limited implementation of a variety of known countermeasures therefore appears to be inconsistent with high-level, strategic goals to improve road safety. Consequently, a recommendation is made to comprehensively re-examine the balance between the countermeasures discussed in this article and economic, mobility, and privacy concerns. IMPACT ON PUBLIC SAFETY: Such a re-examination is likely to result in broad support for these countermeasures, with a consequent major improvement in road safety.

Assessing characteristics related to the use of seatbelts and cell phones by drivers: application of a bivariate probit model.

PubMed

Russo, Brendan J; Kay, Jonathan J; Savolainen, Peter T; Gates, Timothy J

2014-06-01

The effects of cell phone use and safety belt use have been an important focus of research related to driver safety. Cell phone use has been shown to be a significant source of driver distraction contributing to substantial degradations in driver performance, while safety belts have been demonstrated to play a vital role in mitigating injuries to crash-involved occupants. This study examines the prevalence of cell phone use and safety belt non-use among the driving population through direct observation surveys. A bivariate probit model is developed to simultaneously examine the factors that affect cell phone and safety belt use among motor vehicle drivers. The results show that several factors may influence drivers' decision to use cell phones and safety belts, and that these decisions are correlated. Understanding the factors that affect both cell phone use and safety belt non-use is essential to targeting policy and programs that reduce such behavior. Copyright © 2014 Elsevier Ltd. All rights reserved.

Patient safety in primary care: a survey of general practitioners in The Netherlands.

PubMed

Gaal, Sander; Verstappen, Wim; Wensing, Michel

2010-01-21

Primary care encompasses many different clinical domains and patient groups, which means that patient safety in primary care may be equally broad. Previous research on safety in primary care has focused on medication safety and incident reporting. In this study, the views of general practitioners (GPs) on patient safety were examined. A web-based survey of a sample of GPs was undertaken. The items were derived from aspects of patient safety issues identified in a prior interview study. The questionnaire used 10 clinical cases and 15 potential risk factors to explore GPs' views on patient safety. A total of 68 GPs responded (51.5% response rate). None of the clinical cases was uniformly judged as particularly safe or unsafe by the GPs. Cases judged to be unsafe by a majority of the GPs concerned either the maintenance of medical records or prescription and monitoring of medication. Cases which only a few GPs judged as unsafe concerned hygiene, the diagnostic process, prevention and communication. The risk factors most frequently judged to constitute a threat to patient safety were a poor doctor-patient relationship, insufficient continuing education on the part of the GP and a patient age over 75 years. Language barriers and polypharmacy also scored high. Deviation from evidence-based guidelines and patient privacy in the reception/waiting room were not perceived as risk factors by most of the GPs. The views of GPs on safety and risk in primary care did not completely match those presented in published papers and policy documents. The GPs in the present study judged a broader range of factors than in previously published research on patient safety in primary care, including a poor doctor-patient relationship, to pose a potential threat to patient safety. Other risk factors such as infection prevention, deviation from guidelines and incident reporting were judged to be less relevant than by policy makers.

Thin Cu film resistivity using four probe techniques: Effect of film thickness and geometrical shapes

NASA Astrophysics Data System (ADS)

Choudhary, Sumita; Narula, Rahul; Gangopadhyay, Subhashis

2018-05-01

Precise measurement of electrical sheet resistance and resistivity of metallic thin Cu films may play a significant role in temperature sensing by means of resistivity changes which can further act as a safety measure of various electronic devices during their operation. Four point probes resistivity measurement is a useful approach as it successfully excludes the contact resistance between the probes and film surface of the sample. Although, the resistivity of bulk samples at a particular temperature mostly depends on its materialistic property, however, it may significantly differ in the case of thin films, where the shape and thickness of the sample can significantly influence on it. Depending on the ratio of the film thickness to probe spacing, samples are usually classified in two segments such as (i) thick films or (ii) thin films. Accordingly, the geometric correction factors G can be related to the sample resistivity r, which has been calculated here for thin Cu films of thickness up to few 100 nm. In this study, various rectangular shapes of thin Cu films have been used to determine the shape induced geometric correction factors G. An expressions for G have been obtained as a function of film thickness t versus the probe spacing s. Using these expressions, the correction factors have been plotted separately for each cases as a function of (a) film thickness for fixed linear probe spacing and (b) probe distance from the edge of the film surface for particular thickness. Finally, we compare the experimental results of thin Cu films of various rectangular geometries with the theoretical reported results.

Mapping the nomological network of employee self-determined safety motivation: A preliminary measure in China.

PubMed

Jiang, Li; Tetrick, Lois E

2016-09-01

The present study introduced a preliminary measure of employee safety motivation based on the definition of self-determination theory from Fleming (2012) research and validated the structure of self-determined safety motivation (SDSM) by surveying 375 employees in a Chinese high-risk organization. First, confirmatory factor analysis (CFA) was used to examine the factor structure of SDSM, and indices of five-factor model CFA met the requirements. Second, a nomological network was examined to provide evidence of the construct validity of SDSM. Beyond construct validity, the analysis also produced some interesting results concerning the relationship between leadership antecedents and safety motivation, and between safety motivation and safety behavior. Autonomous motivation was positively related to transformational leadership, negatively related to abusive supervision, and positively related to safety behavior. Controlled motivation with the exception of introjected regulation was negatively related to transformational leadership, positively related to abusive supervision, and negatively related to safety behavior. The unique role of introjected regulation and future research based on self-determination theory were discussed. Copyright © 2016 Elsevier Ltd. All rights reserved.

The impact of airport characteristics on airport surface accidents and incidents.

PubMed

Wilke, Sabine; Majumdar, Arnab; Ochieng, Washington Y

2015-06-01

Airport surface safety and in particular runway and taxiway safety is acknowledged globally as one of aviation's greatest challenges. To improve this key area of aviation safety, it is necessary to identify and understand the causal and contributing factors on safety occurrences. While the contribution of human factors, operations, and procedures has been researched extensively, the impact of the airport and its associated characteristics itself has received little or no attention. This paper introduces a novel methodology for risk and hazard assessment of airport surface operations, and models the relationships between airport characteristics, and (a) the rate of occurrences, (b) the severity of occurrences, and (c) the causal factors underlying occurrences. The results show for the first time how the characteristics of airports, and in particular its infrastructure and operations, influence the safety of surface operations. Copyright © 2015 Elsevier Ltd. and National Safety Council. Published by Elsevier Ltd. All rights reserved.

49 CFR Appendix A to Part 385 - Explanation of Safety Audit Evaluation Criteria

Code of Federal Regulations, 2010 CFR

2010-10-01

... safety management controls in place, is included in Appendix B, VII. List of Acute and Critical... having similar characteristics are combined together into six regulatory areas called “factors.” The regulatory factors, evaluated on the basis of the adequacy of the carrier's safety management controls, are...

Modifying Ship Air-Wake Vortices for Aircraft Operations

NASA Technical Reports Server (NTRS)

Lamar, John E.

2004-01-01

Columnar-vortex generators (CVG) have been proposed as means to increase the safety of takeoffs and landings of aircraft on aircraft or helicopter carriers and other ships at sea. According to the proposal, CVGs would be installed at critical edge locations on ships to modify the vortices in the air wakes of the ships. The desired effects of modifications are to smooth airflows over takeoff and landing deck areas and divert vortices from takeoff and landing flight paths. With respect to aircraft operations, the wake flows of primary interest are those associated with the bow and side edges of aircraft-carrier decks and with superstructures of ships in general (see Figure 1). The bow and deck-edge vortices can adversely affect airplane and helicopter operations on carriers, while the superstructure wakes can primarily affect operations of helicopters. The concept of the CVG is not new; what is new is the proposed addition of CVGs to ship structures to effect favorable modifications of air wakes. Figure 2 depicts a basic CVG, vertical and horizontal CVGs installed on a simple superstructure, and horizontal CVGs installed on the bow and deck edges. The vertical CVGs would be closed at the deck but open at the top. Each horizontal CVG would be open at both ends. The dimensions of the CVGs installed on the aft edges of the superstructure would be chosen so that the portion of the flow modified by the vertical CVGs would interact synergistically with the portion of the flow modified by the horizontal CVG to move the air wake away from the takeoff-and-landing zone behind the superstructure. The deck-edge CVGs would be mounted flush with, and would extend slightly ahead of the bow of, the flight deck. The overall length of each tube would exceed that of the flight deck. Each deck-edge CVG would capture that portion of the airflow that generates a deck-edge vortex and would generate a columnar vortex of opposite sense to that of the unmodified vortex. The vortex generated by the CVG could be dispersed at its base, thereby removing unwanted turbulence in the path of an approaching airplane. The deck-edge CVGs would promote smooth flow over the entire flight deck. In the case of a Nimitz-class aircraft carrier like that of Figure 1, there would be a CVG on each of the outer edges of the two left portions of the flight deck and a single CVG on the right side of the flight deck. The forward-most CVG on the left side would take the generated vortex underneath the angled flight deck. A CVG could also be installed on the bow of the flight deck to smooth the flow of air onto the flight deck. In the case of wind incident on the deck from an azimuth other than straight ahead, the vortex generated by the bow CVG could, perhaps, be used to feed the CVG(s) of the leeward side edge of the flight deck.

Aquatic community structure in Mediterranean edge-of-field waterbodies as explained by environmental factors and the presence of pesticide mixtures.

PubMed

Pereira, Ana Santos; Dâmaso-Rodrigues, Maria Luísa; Amorim, Ana; Daam, Michiel A; Cerejeira, Maria José

2018-06-16

Studies addressing the predicted effects of pesticides in combination with abiotic and biotic factors on aquatic biota in ditches associated with typical Mediterranean agroecosystems are scarce. The current study aimed to evaluate the predicted effects of pesticides along with environmental factors and biota interactions on macroinvertebrate, zooplankton and phytoplankton community compositions in ditches adjacent to Portuguese maize and tomato crop areas. Data was analysed with the variance partitioning procedure based on redundancy analysis (RDA). The total variance in biological community composition was divided into the variance explained by the multi-substance potentially affected fraction [(msPAF) arthropods and primary producers], environmental factors (water chemistry parameters), biotic interactions, shared variance, and unexplained variance. The total explained variance reached 39.4% and the largest proportion of this explained variance was attributed to msPAF (23.7%). When each group (phytoplankton, zooplankton and macroinvertebrates) was analysed separately, biota interactions and environmental factors explained the largest proportion of variance. Results of this study indicate that besides the presence of pesticide mixtures, environmental factors and biotic interactions also considerably influence field freshwater communities. Subsequently, to increase our understanding of the risk of pesticide mixtures on ecosystem communities in edge-of-field water bodies, variations in environmental and biological factors should also be considered.