Sample records for accident loading conditions

  1. Simulation of the transient processes of load rejection under different accident conditions in a hydroelectric generating set

    NASA Astrophysics Data System (ADS)

    Guo, W. C.; Yang, J. D.; Chen, J. P.; Peng, Z. Y.; Zhang, Y.; Chen, C. C.

    2016-11-01

    Load rejection test is one of the essential tests that carried out before the hydroelectric generating set is put into operation formally. The test aims at inspecting the rationality of the design of the water diversion and power generation system of hydropower station, reliability of the equipment of generating set and the dynamic characteristics of hydroturbine governing system. Proceeding from different accident conditions of hydroelectric generating set, this paper presents the transient processes of load rejection corresponding to different accident conditions, and elaborates the characteristics of different types of load rejection. Then the numerical simulation method of different types of load rejection is established. An engineering project is calculated to verify the validity of the method. Finally, based on the numerical simulation results, the relationship among the different types of load rejection and their functions on the design of hydropower station and the operation of load rejection test are pointed out. The results indicate that: The load rejection caused by the accident within the hydroelectric generating set is realized by emergency distributing valve, and it is the basis of the optimization for the closing law of guide vane and the calculation of regulation and guarantee. The load rejection caused by the accident outside the hydroelectric generating set is realized by the governor. It is the most efficient measure to inspect the dynamic characteristics of hydro-turbine governing system, and its closure rate of guide vane set in the governor depends on the optimization result in the former type load rejection.

  2. 10 CFR 71.73 - Hypothetical accident conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Hypothetical accident conditions. 71.73 Section 71.73... Package, Special Form, and LSA-III Tests 2 § 71.73 Hypothetical accident conditions. (a) Test procedures. Evaluation for hypothetical accident conditions is to be based on sequential application of the tests...

  3. Predictions of structural integrity of steam generator tubes under normal operating, accident, an severe accident conditions

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

    Majumdar, S.

    1997-02-01

    Available models for predicting failure of flawed and unflawed steam generator tubes under normal operating, accident, and severe accident conditions are reviewed. Tests conducted in the past, though limited, tended to show that the earlier flow-stress model for part-through-wall axial cracks overestimated the damaging influence of deep cracks. This observation was confirmed by further tests at high temperatures, as well as by finite-element analysis. A modified correlation for deep cracks can correct this shortcoming of the model. Recent tests have shown that lateral restraint can significantly increase the failure pressure of tubes with unsymmetrical circumferential cracks. This observation was confirmedmore » by finite-element analysis. The rate-independent flow stress models that are successful at low temperatures cannot predict the rate-sensitive failure behavior of steam generator tubes at high temperatures. Therefore, a creep rupture model for predicting failure was developed and validated by tests under various temperature and pressure loadings that can occur during postulated severe accidents.« less

  4. Fuel cladding behavior under rapid loading conditions

    NASA Astrophysics Data System (ADS)

    Yueh, K.; Karlsson, J.; Stjärnsäter, J.; Schrire, D.; Ledergerber, G.; Munoz-Reja, C.; Hallstadius, L.

    2016-02-01

    A modified burst test (MBT) was used in an extensive test program to characterize fuel cladding failure behavior under rapid loading conditions. The MBT differs from a normal burst test with the use of a driver tube to simulate the expansion of a fuel pellet, thereby producing a partial strain driven deformation condition similar to that of a fuel pellet expansion in a reactivity insertion accident (RIA). A piston/cylinder assembly was used to pressurize the driver tube. By controlling the speed and distance the piston travels the loading rate and degree of sample deformation could be controlled. The use of a driver tube with a machined gauge section localizes deformation and allows for continuous monitoring of the test sample diameter change at the location of maximum hoop strain, during each test. Cladding samples from five irradiated fuel rods were tested between 296 and 553 K and loading rates from 1.5 to 3.5/s. The test rods included variations of Zircaloy-2 with different liners and ZIRLO, ranging in burn-up from 41 to 74 GWd/MTU. The test results show cladding ductility is strongly temperature and loading rate dependent. Zircaloy-2 cladding ductility degradation due to operational hydrogen pickup started to recover at approximately 358 K for test condition used in the study. This recovery temperature is strongly loading rate dependent. At 373 K, ductility recovery was small for loading rates less than 8 ms equivalent RIA pulse width, but longer than 8 ms the ductility recovery increased exponentially with increasing pulse width, consistent with literature observations of loading rate dependent brittle-to-ductile (BTD) transition temperature. The cladding ductility was also observed to be strongly loading rate/pulse width dependent for BWR cladding below the BTD temperature and Pressurized Water Reactor (PWR) cladding at both 296 and 553 K.

  5. 14 CFR 25.485 - Side load conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Side load conditions. 25.485 Section 25.485... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.485 Side load conditions. In addition to § 25.479(d)(2) the following conditions must be considered: (a) For the side load condition, the...

  6. 14 CFR 25.485 - Side load conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Side load conditions. 25.485 Section 25.485... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.485 Side load conditions. In addition to § 25.479(d)(2) the following conditions must be considered: (a) For the side load condition, the...

  7. 14 CFR 25.485 - Side load conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Side load conditions. 25.485 Section 25.485... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.485 Side load conditions. In addition to § 25.479(d)(2) the following conditions must be considered: (a) For the side load condition, the...

  8. Numerical investigations of rib fracture failure models in different dynamic loading conditions.

    PubMed

    Wang, Fang; Yang, Jikuang; Miller, Karol; Li, Guibing; Joldes, Grand R; Doyle, Barry; Wittek, Adam

    2016-01-01

    Rib fracture is one of the most common thoracic injuries in vehicle traffic accidents that can result in fatalities associated with seriously injured internal organs. A failure model is critical when modelling rib fracture to predict such injuries. Different rib failure models have been proposed in prediction of thorax injuries. However, the biofidelity of the fracture failure models when varying the loading conditions and the effects of a rib fracture failure model on prediction of thoracic injuries have been studied only to a limited extent. Therefore, this study aimed to investigate the effects of three rib failure models on prediction of thoracic injuries using a previously validated finite element model of the human thorax. The performance and biofidelity of each rib failure model were first evaluated by modelling rib responses to different loading conditions in two experimental configurations: (1) the three-point bending on the specimen taken from rib and (2) the anterior-posterior dynamic loading to an entire bony part of the rib. Furthermore, the simulation of the rib failure behaviour in the frontal impact to an entire thorax was conducted at varying velocities and the effects of the failure models were analysed with respect to the severity of rib cage damages. Simulation results demonstrated that the responses of the thorax model are similar to the general trends of the rib fracture responses reported in the experimental literature. However, they also indicated that the accuracy of the rib fracture prediction using a given failure model varies for different loading conditions.

  9. 14 CFR 23.485 - Side load conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Side load conditions. 23.485 Section 23.485... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Ground Loads § 23.485 Side load conditions. (a) For the side load condition, the airplane is assumed to be in a level attitude...

  10. 14 CFR 23.485 - Side load conditions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Side load conditions. 23.485 Section 23.485... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Ground Loads § 23.485 Side load conditions. (a) For the side load condition, the airplane is assumed to be in a level attitude...

  11. 14 CFR 23.485 - Side load conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Side load conditions. 23.485 Section 23.485... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Ground Loads § 23.485 Side load conditions. (a) For the side load condition, the airplane is assumed to be in a level attitude...

  12. Key Parameters for Operator Diagnosis of BWR Plant Condition during a Severe Accident

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

    Clayton, Dwight A.; Poore, III, Willis P.

    2015-01-01

    The objective of this research is to examine the key information needed from nuclear power plant instrumentation to guide severe accident management and mitigation for boiling water reactor (BWR) designs (specifically, a BWR/4-Mark I), estimate environmental conditions that the instrumentation will experience during a severe accident, and identify potential gaps in existing instrumentation that may require further research and development. This report notes the key parameters that instrumentation needs to measure to help operators respond to severe accidents. A follow-up report will assess severe accident environmental conditions as estimated by severe accident simulation model analysis for a specific US BWR/4-Markmore » I plant for those instrumentation systems considered most important for accident management purposes.« less

  13. Preliminary Modeling of Accident Tolerant Fuel Concepts under Accident Conditions

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

    Gamble, Kyle A.; Hales, Jason D.

    2016-12-01

    The catastrophic events that occurred at the Fukushima-Daiichi nuclear power plant in 2011 have led to widespread interest in research of alternative fuels and claddings that are proposed to be accident tolerant. Thus, the United States Department of Energy through its NEAMS (Nuclear Energy Advanced Modeling and Simulation) program has funded an Accident Tolerant Fuel (ATF) High Impact Problem (HIP). The ATF HIP is funded for a three-year period. The purpose of the HIP is to perform research into two potential accident tolerant concepts and provide an in-depth report to the Advanced Fuels Campaign (AFC) describing the behavior of themore » concepts, both of which are being considered for inclusion in a lead test assembly scheduled for placement into a commercial reactor in 2022. The initial focus of the HIP is on uranium silicide fuel and iron-chromium-aluminum (FeCrAl) alloy cladding. Utilizing the expertise of three national laboratory participants (INL, LANL, and ANL) a comprehensive mulitscale approach to modeling is being used including atomistic modeling, molecular dynamics, rate theory, phase-field, and fuel performance simulations. In this paper, we present simulations of two proposed accident tolerant fuel systems: U3Si2 fuel with Zircaloy-4 cladding, and UO2 fuel with FeCrAl cladding. The simulations investigate the fuel performance response of the proposed ATF systems under Loss of Coolant and Station Blackout conditions using the BISON code. Sensitivity analyses are completed using Sandia National Laboratories’ DAKOTA software to determine which input parameters (e.g., fuel specific heat) have the greatest influence on the output metrics of interest (e.g., fuel centerline temperature). Early results indicate that each concept has significant advantages as well as areas of concern. Further work is required prior to formulating the proposition report for the Advanced Fuels Campaign.« less

  14. Preliminary assessment of accident-tolerant fuels on LWR performance during normal operation and under DB and BDB accident conditions

    NASA Astrophysics Data System (ADS)

    Ott, L. J.; Robb, K. R.; Wang, D.

    2014-05-01

    Following the severe accidents at the Japanese Fukushima Daiichi Nuclear Power Station in 2011, the US Department of Energy initiated research and development on the enhancement of the accident tolerance of light water reactors by the development of fuels/cladding that, in comparison with the standard UO2/Zircaloy (Zr) system, can tolerate loss of active cooling in the core for a considerably longer time period while maintaining or improving the fuel performance during normal operations. Analyses are presented that illustrate the impact of these new candidate fuel/cladding materials on the fuel performance at normal operating conditions and on the reactor system under DB and BDB accident conditions.

  15. Relationship between work-related accidents and hot weather conditions in Tuscany (central Italy).

    PubMed

    Morabito, Marco; Cecchi, Lorenzo; Crisci, Alfonso; Modesti, Pietro Amedeo; Orlandini, Simone

    2006-07-01

    Nowadays, no studies have been published on the relationship between meteorological conditions and work-related mortality and morbidity in Italy. The aim of this study was to evaluate the relationship between hot weather conditions and hospital admissions due to work-related accidents in Tuscany (central Italy) over the period 1998-2003. Apparent temperature (AT) values were calculated to evaluate human weather discomfort due to hot conditions and then tested for work accident differences using non-parametric procedures. Present findings showed that hot weather conditions might represent a risk factor for work-related accidents in Italy during summer. In particular early warming days during June, characterized by heat discomfort, are less tolerated by workers than warming days of the following summer months. The peak of work-related accidents occurred on days characterized by high, but not extreme, thermal conditions. Workers maybe change their behaviour when heat stress increases, reducing risks by adopting preventive measures. Results suggested that days with an average daytime AT value ranged between 24.8 degrees C and 27.5 degrees C were at the highest risk of work-related accidents. In conclusion, present findings might represent the first step for the development of a watch/warning system for workers that might be used by employers for planning work activities.

  16. Local Dynamic Stability Associated with Load Carrying

    PubMed Central

    Lockhart, Thurmon E

    2013-01-01

    Objectives Load carrying tasks are recognized as one of the primary occupational factors leading to slip and fall injuries. Nevertheless, the mechanisms associated with load carrying and walking stability remain illusive. The objective of the current study was to apply local dynamic stability measure in walking while carrying a load, and to investigate the possible adaptive gait stability changes. Methods Current study involved 25 young adults in a biomechanics research laboratory. One tri-axial accelerometer was used to measure three-dimensional low back acceleration during continuous treadmill walking. Local dynamic stability was quantified by the maximum Lyapunov exponent (maxLE) from a nonlinear dynamics approach. Results Long term maxLE was found to be significant higher under load condition than no-load condition in all three reference axes, indicating the declined local dynamic stability associated with load carrying. Conclusion Current study confirmed the sensitivity of local dynamic stability measure in load carrying situation. It was concluded that load carrying tasks were associated with declined local dynamic stability, which may result in increased risk of fall accident. This finding has implications in preventing fall accidents associated with occupational load carrying. PMID:23515183

  17. 14 CFR 23.521 - Water load conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Water load conditions. 23.521 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.521 Water load conditions. (a) The structure of seaplanes and amphibians must be designed for water...

  18. 14 CFR 23.521 - Water load conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Water load conditions. 23.521 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.521 Water load conditions. (a) The structure of seaplanes and amphibians must be designed for water...

  19. 14 CFR 23.521 - Water load conditions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Water load conditions. 23.521 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.521 Water load conditions. (a) The structure of seaplanes and amphibians must be designed for water...

  20. 14 CFR 23.521 - Water load conditions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Water load conditions. 23.521 Section 23... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Water Loads § 23.521 Water load conditions. (a) The structure of seaplanes and amphibians must be designed for water...

  1. Structural Analysis for the American Airlines Flight 587 Accident Investigation: Global Analysis

    NASA Technical Reports Server (NTRS)

    Young, Richard D.; Lovejoy, Andrew E.; Hilburger, Mark W.; Moore, David F.

    2005-01-01

    NASA Langley Research Center (LaRC) supported the National Transportation Safety Board (NTSB) in the American Airlines Flight 587 accident investigation due to LaRC's expertise in high-fidelity structural analysis and testing of composite structures and materials. A Global Analysis Team from LaRC reviewed the manufacturer s design and certification procedures, developed finite element models and conducted structural analyses, and participated jointly with the NTSB and Airbus in subcomponent tests conducted at Airbus in Hamburg, Germany. The Global Analysis Team identified no significant or obvious deficiencies in the Airbus certification and design methods. Analysis results from the LaRC team indicated that the most-likely failure scenario was failure initiation at the right rear main attachment fitting (lug), followed by an unstable progression of failure of all fin-to-fuselage attachments and separation of the VTP from the aircraft. Additionally, analysis results indicated that failure initiates at the final observed maximum fin loading condition in the accident, when the VTP was subjected to loads that were at minimum 1.92 times the design limit load condition for certification. For certification, the VTP is only required to support loads of 1.5 times design limit load without catastrophic failure. The maximum loading during the accident was shown to significantly exceed the certification requirement. Thus, the structure appeared to perform in a manner consistent with its design and certification, and failure is attributed to VTP loads greater than expected.

  2. Helicopter sling load accident/incident survey: 1968 - 1974

    NASA Technical Reports Server (NTRS)

    Shaughnessy, J. D.; Pardue, M. D.

    1977-01-01

    During the period considered a mean of eleven accidents per year occurred and a mean of eleven persons were killed or seriously injured per year. Forty-one percent of the accidents occurred during hover, and 63 percent of the accidents had pilot error listed as a cause/factor. Many accidents involved pilots losing control of the helicopter or allowing a collision with obstructions to occur. There was a mean of 58 incidents each year and 51 percent of these occurred during cruise.

  3. NASA Structural Analysis Report on the American Airlines Flight 587 Accident - Local Analysis of the Right Rear Lug

    NASA Technical Reports Server (NTRS)

    Raju, Ivatury S; Glaessgen, Edward H.; Mason, Brian H; Krishnamurthy, Thiagarajan; Davila, Carlos G

    2005-01-01

    A detailed finite element analysis of the right rear lug of the American Airlines Flight 587 - Airbus A300-600R was performed as part of the National Transportation Safety Board s failure investigation of the accident that occurred on November 12, 2001. The loads experienced by the right rear lug are evaluated using global models of the vertical tail, local models near the right rear lug, and a global-local analysis procedure. The right rear lug was analyzed using two modeling approaches. In the first approach, solid-shell type modeling is used, and in the second approach, layered-shell type modeling is used. The solid-shell and the layered-shell modeling approaches were used in progressive failure analyses (PFA) to determine the load, mode, and location of failure in the right rear lug under loading representative of an Airbus certification test conducted in 1985 (the 1985-certification test). Both analyses were in excellent agreement with each other on the predicted failure loads, failure mode, and location of failure. The solid-shell type modeling was then used to analyze both a subcomponent test conducted by Airbus in 2003 (the 2003-subcomponent test) and the accident condition. Excellent agreement was observed between the analyses and the observed failures in both cases. From the analyses conducted and presented in this paper, the following conclusions were drawn. The moment, Mx (moment about the fuselage longitudinal axis), has significant effect on the failure load of the lugs. Higher absolute values of Mx give lower failure loads. The predicted load, mode, and location of the failure of the 1985-certification test, 2003-subcomponent test, and the accident condition are in very good agreement. This agreement suggests that the 1985-certification and 2003- subcomponent tests represent the accident condition accurately. The failure mode of the right rear lug for the 1985-certification test, 2003-subcomponent test, and the accident load case is identified as a

  4. Key risk indicators for accident assessment conditioned on pre-crash vehicle trajectory.

    PubMed

    Shi, X; Wong, Y D; Li, M Z F; Chai, C

    2018-08-01

    Accident events are generally unexpected and occur rarely. Pre-accident risk assessment by surrogate indicators is an effective way to identify risk levels and thus boost accident prediction. Herein, the concept of Key Risk Indicator (KRI) is proposed, which assesses risk exposures using hybrid indicators. Seven metrics are shortlisted as the basic indicators in KRI, with evaluation in terms of risk behaviour, risk avoidance, and risk margin. A typical real-world chain-collision accident and its antecedent (pre-crash) road traffic movements are retrieved from surveillance video footage, and a grid remapping method is proposed for data extraction and coordinates transformation. To investigate the feasibility of each indicator in risk assessment, a temporal-spatial case-control is designed. By comparison, Time Integrated Time-to-collision (TIT) performs better in identifying pre-accident risk conditions; while Crash Potential Index (CPI) is helpful in further picking out the severest ones (the near-accident). Based on TIT and CPI, the expressions of KRIs are developed, which enable us to evaluate risk severity with three levels, as well as the likelihood. KRI-based risk assessment also reveals predictive insights about a potential accident, including at-risk vehicles, locations and time. Furthermore, straightforward thresholds are defined flexibly in KRIs, since the impact of different threshold values is found not to be very critical. For better validation, another independent real-world accident sample is examined, and the two results are in close agreement. Hierarchical indicators such as KRIs offer new insights about pre-accident risk exposures, which is helpful for accident assessment and prediction. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. The Mechanical Response of Advanced Claddings during Proposed Reactivity Initiated Accident Conditions

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

    Cinbiz, Mahmut N; Brown, Nicholas R; Terrani, Kurt A

    2017-01-01

    This study investigates the failure mechanisms of advanced nuclear fuel cladding of FeCrAl at high-strain rates, similar to design basis reactivity initiated accidents (RIA). During RIA, the nuclear fuel cladding was subjected to the plane-strain to equibiaxial tension strain states. To achieve those accident conditions, the samples were deformed by the expansion of high strength Inconel alloy tube under pre-specified pressure pulses as occurring RIA. The mechanical response of the advanced claddings was compared to that of hydrided zirconium-based nuclear fuel cladding alloy. The hoop strain evolution during pressure pulses were collected in situ; the permanent diametral strains of bothmore » accident tolerant fuel (ATF) claddings and the current nuclear fuel alloys were determined after rupture.« less

  6. 24 CFR 3285.315 - Special snow load conditions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... HOUSING AND URBAN DEVELOPMENT MODEL MANUFACTURED HOME INSTALLATION STANDARDS Foundations § 3285.315 Special snow load conditions. (a) General. Foundations for homes designed for and located in areas with roof live loads greater than 40 psf must be designed by the manufacturer for the special snow load...

  7. Force-Strain Characteristics and Rupture-Load Capability of Viking-Type Suspension-Line Material Under Dynamic Loading Conditions

    NASA Technical Reports Server (NTRS)

    Poole, Lamont R.; Councill, Earl L., Jr.

    1972-01-01

    A series of tests has been conducted to investigate the elastic behavior of Viking-type suspension-line material under dynamic loading conditions. Results indicate that there is a decrease in both rupture-load capability and elongation at rupture as the test strain rate is increased. Preliminary examination of force-strain characteristics indicates that, on the average, the material exhibits some type of viscous effect which results in a greater force being produced, for a particular value of strain, under dynamic loading conditions than that produced under quasi-static loading conditions. A great deal of uncertainty exists in defining a priori the tensile properties of viscoelastic materials, such as nylon or dacron, under dynamic loading conditions. Additional uncertainty enters the picture when woven configurations such as suspension,line material are considered. To eliminate these uncertainties, with respect to the Viking parachute configuration, a test program has been conducted to obtain data on the tensile properties of Viking-type suspension-line material over a wide range of strain rates. Based on preliminary examination of these data, the following conclusions can be drawn: 1. Material rupture-load capability decreases as strain-rate is increased. At strain rates above 75 percent/sec, no rupture loads were observed which would meet the minimum tensile strength specification of 880 pounds. 2. The material, on the average, exhibits some type of viscous effect which, for a particular value of strain, produces a greater load under dynamic loading conditions than that produced under quasi-static loading conditions.

  8. CFD analysis of linear compressors considering load conditions

    NASA Astrophysics Data System (ADS)

    Bae, Sanghyun; Oh, Wonsik

    2017-08-01

    This paper is a study on computational fluid dynamics (CFD) analysis of linear compressor considering load conditions. In the conventional CFD analysis of the linear compressor, the load condition was not considered in the behaviour of the piston. In some papers, behaviour of piston is assumed as sinusoidal motion provided by user defined function (UDF). In the reciprocating type compressor, the stroke of the piston is restrained by the rod, while the stroke of the linear compressor is not restrained, and the stroke changes depending on the load condition. The greater the pressure difference between the discharge refrigerant and the suction refrigerant, the more the centre point of the stroke is pushed backward. And the behaviour of the piston is not a complete sine wave. For this reason, when the load condition changes in the CFD analysis of the linear compressor, it may happen that the ANSYS code is changed or unfortunately the modelling is changed. In addition, a separate analysis or calculation is required to find a stroke that meets the load condition, which may contain errors. In this study, the coupled mechanical equations and electrical equations are solved using the UDF, and the behaviour of the piston is solved considering the pressure difference across the piston. Using the above method, the stroke of the piston with respect to the motor specification of the analytical model can be calculated according to the input voltage, and the piston behaviour can be realized considering the thrust amount due to the pressure difference.

  9. 14 CFR 23.473 - Ground load conditions and assumptions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... vertical inertia load factor at the center of gravity of the airplane for the ground load conditions... through the center of gravity. The ground reaction load factor may be equal to the inertia load factor..., these tests must be made under § 23.723(a). (g) No inertia load factor used for design purposes may be...

  10. 14 CFR 23.473 - Ground load conditions and assumptions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... vertical inertia load factor at the center of gravity of the airplane for the ground load conditions... through the center of gravity. The ground reaction load factor may be equal to the inertia load factor..., these tests must be made under § 23.723(a). (g) No inertia load factor used for design purposes may be...

  11. 14 CFR 23.473 - Ground load conditions and assumptions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... vertical inertia load factor at the center of gravity of the airplane for the ground load conditions... through the center of gravity. The ground reaction load factor may be equal to the inertia load factor..., these tests must be made under § 23.723(a). (g) No inertia load factor used for design purposes may be...

  12. 14 CFR 23.473 - Ground load conditions and assumptions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... vertical inertia load factor at the center of gravity of the airplane for the ground load conditions... through the center of gravity. The ground reaction load factor may be equal to the inertia load factor..., these tests must be made under § 23.723(a). (g) No inertia load factor used for design purposes may be...

  13. 14 CFR 23.473 - Ground load conditions and assumptions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... vertical inertia load factor at the center of gravity of the airplane for the ground load conditions... through the center of gravity. The ground reaction load factor may be equal to the inertia load factor..., these tests must be made under § 23.723(a). (g) No inertia load factor used for design purposes may be...

  14. 14 CFR 25.485 - Side load conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... accordance with figure 5 of appendix A. (b) Side loads of 0.8 of the vertical reaction (on one side) acting inward and 0.6 of the vertical reaction (on the other side) acting outward must be combined with one-half of the maximum vertical ground reactions obtained in the level landing conditions. These loads are...

  15. 14 CFR 25.485 - Side load conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... accordance with figure 5 of appendix A. (b) Side loads of 0.8 of the vertical reaction (on one side) acting inward and 0.6 of the vertical reaction (on the other side) acting outward must be combined with one-half of the maximum vertical ground reactions obtained in the level landing conditions. These loads are...

  16. 10 CFR 71.74 - Accident conditions for air transport of plutonium.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Accident conditions for air transport of plutonium. 71.74 Section 71.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE... in a manner that prevents any members or devices used to support the bar from contacting the package...

  17. 10 CFR 71.74 - Accident conditions for air transport of plutonium.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Accident conditions for air transport of plutonium. 71.74 Section 71.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE... in a manner that prevents any members or devices used to support the bar from contacting the package...

  18. 10 CFR 71.74 - Accident conditions for air transport of plutonium.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Accident conditions for air transport of plutonium. 71.74 Section 71.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE... in a manner that prevents any members or devices used to support the bar from contacting the package...

  19. 10 CFR 71.74 - Accident conditions for air transport of plutonium.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Accident conditions for air transport of plutonium. 71.74 Section 71.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE... in a manner that prevents any members or devices used to support the bar from contacting the package...

  20. 10 CFR 71.74 - Accident conditions for air transport of plutonium.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Accident conditions for air transport of plutonium. 71.74 Section 71.74 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) PACKAGING AND TRANSPORTATION OF RADIOACTIVE... in a manner that prevents any members or devices used to support the bar from contacting the package...

  1. Five Common Bus Accidents--And How to Prevent Them.

    ERIC Educational Resources Information Center

    Fuller, Ronald

    1989-01-01

    Analyses of school bus accidents point to five accident-producing categories: (1) rear-end collisions; (2) sideswipes; (3) backing; (4) right turns; and (5) loading/unloading students. Reviews an accident of each type and focuses on the corrective action needed to reduce these accidents. (MLF)

  2. Causal Factors and Adverse Conditions of Aviation Accidents and Incidents Related to Integrated Resilient Aircraft Control

    NASA Technical Reports Server (NTRS)

    Reveley, Mary S.; Briggs, Jeffrey L.; Evans, Joni K.; Sandifer, Carl E.; Jones, Sharon Monica

    2010-01-01

    The causal factors of accidents from the National Transportation Safety Board (NTSB) database and incidents from the Federal Aviation Administration (FAA) database associated with loss of control (LOC) were examined for four types of operations (i.e., Federal Aviation Regulation Part 121, Part 135 Scheduled, Part 135 Nonscheduled, and Part 91) for the years 1988 to 2004. In-flight LOC is a serious aviation problem. Well over half of the LOC accidents included at least one fatality (80 percent in Part 121), and roughly half of all aviation fatalities in the studied time period occurred in conjunction with LOC. An adverse events table was updated to provide focus to the technology validation strategy of the Integrated Resilient Aircraft Control (IRAC) Project. The table contains three types of adverse conditions: failure, damage, and upset. Thirteen different adverse condition subtypes were gleaned from the Aviation Safety Reporting System (ASRS), the FAA Accident and Incident database, and the NTSB database. The severity and frequency of the damage conditions, initial test conditions, and milestones references are also provided.

  3. Analysis 320 coal mine accidents using structural equation modeling with unsafe conditions of the rules and regulations as exogenous variables.

    PubMed

    Zhang, Yingyu; Shao, Wei; Zhang, Mengjia; Li, Hejun; Yin, Shijiu; Xu, Yingjun

    2016-07-01

    Mining has been historically considered as a naturally high-risk industry worldwide. Deaths caused by coal mine accidents are more than the sum of all other accidents in China. Statistics of 320 coal mine accidents in Shandong province show that all accidents contain indicators of "unsafe conditions of the rules and regulations" with a frequency of 1590, accounting for 74.3% of the total frequency of 2140. "Unsafe behaviors of the operator" is another important contributory factor, which mainly includes "operator error" and "venturing into dangerous places." A systems analysis approach was applied by using structural equation modeling (SEM) to examine the interactions between the contributory factors of coal mine accidents. The analysis of results leads to three conclusions. (i) "Unsafe conditions of the rules and regulations," affect the "unsafe behaviors of the operator," "unsafe conditions of the equipment," and "unsafe conditions of the environment." (ii) The three influencing factors of coal mine accidents (with the frequency of effect relation in descending order) are "lack of safety education and training," "rules and regulations of safety production responsibility," and "rules and regulations of supervision and inspection." (iii) The three influenced factors (with the frequency in descending order) of coal mine accidents are "venturing into dangerous places," "poor workplace environment," and "operator error." Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Multi-phase model development to assess RCIC system capabilities under severe accident conditions

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

    Kirkland, Karen Vierow; Ross, Kyle; Beeny, Bradley

    The Reactor Core Isolation Cooling (RCIC) System is a safety-related system that provides makeup water for core cooling of some Boiling Water Reactors (BWRs) with a Mark I containment. The RCIC System consists of a steam-driven Terry turbine that powers a centrifugal, multi-stage pump for providing water to the reactor pressure vessel. The Fukushima Dai-ichi accidents demonstrated that the RCIC System can play an important role under accident conditions in removing core decay heat. The unexpectedly sustained, good performance of the RCIC System in the Fukushima reactor demonstrates, firstly, that its capabilities are not well understood, and secondly, that themore » system has high potential for extended core cooling in accident scenarios. Better understanding and analysis tools would allow for more options to cope with a severe accident situation and to reduce the consequences. The objectives of this project were to develop physics-based models of the RCIC System, incorporate them into a multi-phase code and validate the models. This Final Technical Report details the progress throughout the project duration and the accomplishments.« less

  5. Role of Winter Weather Conditions and Slipperiness on Tourists' Accidents in Finland.

    PubMed

    Lépy, Élise; Rantala, Sinikka; Huusko, Antti; Nieminen, Pentti; Hippi, Marjo; Rautio, Arja

    2016-08-15

    (1) BACKGROUND: In Finland, slippery snowy or icy ground surface conditions can be quite hazardous to human health during wintertime. We focused on the impacts of the variability in weather conditions on tourists' health via documented accidents during the winter season in the Sotkamo area. We attempted to estimate the slipping hazard in a specific context of space and time focusing on the weather and other possible parameters, responsible for fluctuations in the numbers of injuries/accidents; (2) METHODS: We used statistical distributions with graphical illustrations to examine the distribution of visits to Kainuu Hospital by non-local patients and their characteristics/causes; graphs to illustrate the distribution of the different characteristics of weather conditions; questionnaires and interviews conducted among health care and safety personnel in Sotkamo and Kuusamo; (3) RESULTS: There was a clear seasonal distribution in the numbers and types of extremity injuries of non-local patients. While the risk of slipping is emphasized, other factors leading to injuries are evaluated; and (4) CONCLUSIONS: The study highlighted the clear role of wintery weather conditions as a cause of extremity injuries even though other aspects must also be considered. Future scenarios, challenges and adaptive strategies are also discussed from the viewpoint of climate change.

  6. Role of Winter Weather Conditions and Slipperiness on Tourists’ Accidents in Finland

    PubMed Central

    Lépy, Élise; Rantala, Sinikka; Huusko, Antti; Nieminen, Pentti; Hippi, Marjo; Rautio, Arja

    2016-01-01

    (1) Background: In Finland, slippery snowy or icy ground surface conditions can be quite hazardous to human health during wintertime. We focused on the impacts of the variability in weather conditions on tourists’ health via documented accidents during the winter season in the Sotkamo area. We attempted to estimate the slipping hazard in a specific context of space and time focusing on the weather and other possible parameters, responsible for fluctuations in the numbers of injuries/accidents; (2) Methods: We used statistical distributions with graphical illustrations to examine the distribution of visits to Kainuu Hospital by non-local patients and their characteristics/causes; graphs to illustrate the distribution of the different characteristics of weather conditions; questionnaires and interviews conducted among health care and safety personnel in Sotkamo and Kuusamo; (3) Results: There was a clear seasonal distribution in the numbers and types of extremity injuries of non-local patients. While the risk of slipping is emphasized, other factors leading to injuries are evaluated; and (4) Conclusions: The study highlighted the clear role of wintery weather conditions as a cause of extremity injuries even though other aspects must also be considered. Future scenarios, challenges and adaptive strategies are also discussed from the viewpoint of climate change. PMID:27537899

  7. Low-Load Space Conditioning Needs Assessment

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

    Puttagunta, Srikanth

    Heating, ventilating, and air-conditioning (HVAC) equipment must be right-sized to ensure energy performance and comfort. With limited low-load options in the HVAC market, many new-construction housing units are being fitted with oversized equipment that creates system efficiency, comfort, and cost penalties. To bridge the gap between currently available HVAC equipment that is oversized or inefficient and the rising demand for low-load HVAC equipment in the marketplace, HVAC equipment manufacturers need to be fully aware of the needs of the multifamily building and attached single-family (duplex and townhouse) home market. Over the past decade, Steven Winter Associates, Inc. (SWA) has providedmore » certification and consulting services for hundreds of housing projects and has accrued a large pool of data that describe multifamily and attached single-family home characteristics. The U.S. Department of Energy’s Building America research team Consortium for Advanced Residential Buildings (CARB) compiled and analyzed these data to outline the characteristics of low-load dwellings such as the heating and cooling design loads.« less

  8. Investigation of air cleaning system response to accident conditions

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

    Andrae, R.W.; Bolstad, J.W.; Foster, R.D.

    1980-01-01

    Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported.

  9. Selecting boundary conditions in physiological strain analysis of the femur: Balanced loads, inertia relief method and follower load.

    PubMed

    Heyland, Mark; Trepczynski, Adam; Duda, Georg N; Zehn, Manfred; Schaser, Klaus-Dieter; Märdian, Sven

    2015-12-01

    Selection of boundary constraints may influence amount and distribution of loads. The purpose of this study is to analyze the potential of inertia relief and follower load to maintain the effects of musculoskeletal loads even under large deflections in patient specific finite element models of intact or fractured bone compared to empiric boundary constraints which have been shown to lead to physiological displacements and surface strains. The goal is to elucidate the use of boundary conditions in strain analyses of bones. Finite element models of the intact femur and a model of clinically relevant fracture stabilization by locking plate fixation were analyzed with normal walking loading conditions for different boundary conditions, specifically re-balanced loading, inertia relief and follower load. Peak principal cortex surface strains for different boundary conditions are consistent (maximum deviation 13.7%) except for inertia relief without force balancing (maximum deviation 108.4%). Influence of follower load on displacements increases with higher deflection in fracture model (from 3% to 7% for force balanced model). For load balanced models, follower load had only minor influence, though the effect increases strongly with higher deflection. Conventional constraints of fixed nodes in space should be carefully reconsidered because their type and position are challenging to justify and for their potential to introduce relevant non-physiological reaction forces. Inertia relief provides an alternative method which yields physiological strain results. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  10. Numerical optimization of composite hip endoprostheses under different loading conditions

    NASA Technical Reports Server (NTRS)

    Blake, T. A.; Davy, D. T.; Saravanos, D. A.; Hopkins, D. A.

    1992-01-01

    The optimization of composite hip implants was investigated. Emphasis was placed on the effect of shape and material tailoring of the implant to improve the implant-bone interaction. A variety of loading conditions were investigated to better understand the relationship between loading and optimization outcome. Comparisons of the initial and optimal models with more complex 3D finite element models were performed. The results indicate that design improvements made using this method result in similar improvements in the 3D models. Although the optimization outcomes were significantly affected by the choice of loading conditions, certain trends were observed that were independent of the applied loading.

  11. A cascading failure model for analyzing railway accident causation

    NASA Astrophysics Data System (ADS)

    Liu, Jin-Tao; Li, Ke-Ping

    2018-01-01

    In this paper, a new cascading failure model is proposed for quantitatively analyzing the railway accident causation. In the model, the loads of nodes are redistributed according to the strength of the causal relationships between the nodes. By analyzing the actual situation of the existing prevention measures, a critical threshold of the load parameter in the model is obtained. To verify the effectiveness of the proposed cascading model, simulation experiments of a train collision accident are performed. The results show that the cascading failure model can describe the cascading process of the railway accident more accurately than the previous models, and can quantitatively analyze the sensitivities and the influence of the causes. In conclusion, this model can assist us to reveal the latent rules of accident causation to reduce the occurrence of railway accidents.

  12. Instantaneous angular speed monitoring of gearboxes under non-cyclic stationary load conditions

    NASA Astrophysics Data System (ADS)

    Stander, C. J.; Heyns, P. S.

    2005-07-01

    Recent developments in the condition monitoring and asset management market have led to the commercialisation of online vibration-monitoring systems. These systems are primarily utilised to monitor large mineral mining equipment such as draglines, continuous miners and hydraulic shovels. Online monitoring systems make diagnostic information continuously available for asset management, production outsourcing and maintenance alliances with equipment manufacturers. However, most online vibration-monitoring systems are based on conventional vibration-monitoring technologies, which are prone to giving false equipment deterioration warnings on gears that operate under fluctuating load conditions. A simplified mathematical model of a gear system was developed to illustrate the feasibility of monitoring the instantaneous angular speed (IAS) as a means of monitoring the condition of gears that are subjected to fluctuating load conditions. A distinction is made between cyclic stationary load modulation and non-cyclic stationary load modulation. It is shown that rotation domain averaging will suppress the modulation caused by non-cyclic stationary load conditions but will not suppress the modulation caused by cyclic stationary load conditions. An experimental investigation on a test rig indicated that the IAS of a gear shaft could be monitored with a conventional shaft encoder to indicate a deteriorating gear fault condition.

  13. Predicting the impact of chronic health conditions on workplace productivity and accidents: results from two US Department of Energy national laboratories.

    PubMed

    Frey, Jodi Jacobson; Osteen, Philip J; Berglund, Patricia A; Jinnett, Kimberly; Ko, Jungyai

    2015-04-01

    Examine associations of chronic health conditions on workplace productivity and accidents among US Department of Energy employees. The Health and Work Performance Questionnaire-Select was administered to a random sample of two Department of Energy national laboratory employees (46% response rate; N = 1854). The majority (87.4%) reported having one or more chronic health conditions, with 43.4% reporting four or more conditions. A population-attributable risk proportions analysis suggests improvements of 4.5% in absenteeism, 5.1% in presenteeism, 8.9% in productivity, and 77% of accidents by reducing the number of conditions by one level. Depression was the only health condition associated with all four outcomes. Results suggest that chronic conditions in this workforce are prevalent and costly. Efforts to prevent or reduce condition comorbidity among employees with multiple conditions can significantly reduce costs and workplace accident rates.

  14. a Study of the Interferences with the On-Line Radioiodine Measurement Under Nuclear Accident Conditions

    NASA Astrophysics Data System (ADS)

    Tseng, Tung-Tse

    In this research the interferences with the on -line detection of radioiodines, under nuclear accident conditions, were studied. The special tool employed for this research is the developed on-line radioiodine monitor (the Penn State Radioiodine Monitor), which is capable of detecting low levels of radioiodine on-line in air containing orders of magnitude higher levels of radioactive noble gases. Most of the data reported in this thesis were collected during a series of experiments called "Source -Term Experiment Program (STEP)." The experiments were conducted at the Argonne National Laboratory's TREAT reactor located at the Idaho National Engineering Laboratory (INEL). In these tests, fission products were released from the Light Water Reactor (LWR) test fuels as a result of simulating a reactor accident. The Penn State Monitor was then used to sample the fission products accumulated in a large container which simulated the reactor containment building. The test results proved that the Penn State Monitor was not affected significantly by the passage of large amounts of noble gases through the system. Also, it confirmed the predicted results that the operation of conventional on-line radioiodine detectors would, under nuclear accident conditions, be seriously impaired by the passage of high concentrations of radioactive noble gases through such systems. This work also demonstrated that under conditions of high noble gas concentrations and low radioiodine concentrations, the formation of noble-gas-decayed alkali metals can seriously interfere with the on-line detection of radioiodine, especially during the 24 hours immediately after the accident. The decayed alkali metal particulates were also found to be much more penetrating than the ordinary type of particulates, since a large fraction (15%) of the particulates were found to penetrate through the commonly used High Efficiency Particulate Air (HEPA) filter (rated >99.97% for 0.3 (mu)m particulate). Also, a

  15. Behavior of an improved Zr fuel cladding with oxidation resistant coating under loss-of-coolant accident conditions

    NASA Astrophysics Data System (ADS)

    Park, Dong Jun; Kim, Hyun Gil; Jung, Yang Il; Park, Jung Hwan; Yang, Jae Ho; Koo, Yang Hyun

    2016-12-01

    This study investigates protective coatings for improving the high temperature oxidation resistance of Zr fuel claddings for light water nuclear reactors. FeCrAl alloy and Cr layers were deposited onto Zr plates and tubes using cold spraying. For the FeCrAl/Zr system, a Mo layer was introduced between the FeCrAl coating and the Zr matrix to prevent inter-diffusion at high temperatures. Both the FeCrAl and Cr coatings improved the oxidation resistance compared to that of the uncoated Zr alloy when exposed to a steam environment at 1200 °C. The ballooning behavior and mechanical properties of the coated cladding samples were studied under simulated loss-of-coolant accident conditions. The coated samples showed higher burst temperatures, lower circumferential strain, and smaller rupture openings compared to the uncoated Zr. Although 4-point bend tests of the coated samples showed a small increase in the maximum load, ring compression tests of a sectioned sample showed increased ductility.

  16. Accident resistant transport container

    DOEpatents

    Andersen, John A.; Cole, James K.

    1980-01-01

    The invention relates to a container for the safe air transport of plutonium having several intermediate wood layers and a load spreader intermediate an inner container and an outer shell for mitigation of shock during a hypothetical accident.

  17. Accident resistant transport container

    DOEpatents

    Anderson, J.A.; Cole, K.K.

    The invention relates to a container for the safe air transport of plutonium having several intermediate wood layers and a load spreader intermediate an inner container and an outer shell for mitigation of shock during a hypothetical accident.

  18. Professional experience and traffic accidents/near-miss accidents among truck drivers.

    PubMed

    Girotto, Edmarlon; Andrade, Selma Maffei de; González, Alberto Durán; Mesas, Arthur Eumann

    2016-10-01

    To investigate the relationship between the time working as a truck driver and the report of involvement in traffic accidents or near-miss accidents. A cross-sectional study was performed with truck drivers transporting products from the Brazilian grain harvest to the Port of Paranaguá, Paraná, Brazil. The drivers were interviewed regarding sociodemographic characteristics, working conditions, behavior in traffic and involvement in accidents or near-miss accidents in the previous 12 months. Subsequently, the participants answered a self-applied questionnaire on substance use. The time of professional experience as drivers was categorized in tertiles. Statistical analyses were performed through the construction of models adjusted by multinomial regression to assess the relationship between the length of experience as a truck driver and the involvement in accidents or near-miss accidents. This study included 665 male drivers with an average age of 42.2 (±11.1) years. Among them, 7.2% and 41.7% of the drivers reported involvement in accidents and near-miss accidents, respectively. In fully adjusted analysis, the 3rd tertile of professional experience (>22years) was shown to be inversely associated with involvement in accidents (odds ratio [OR] 0.29; 95% confidence interval [CI] 0.16-0.52) and near-miss accidents (OR 0.17; 95% CI 0.05-0.53). The 2nd tertile of professional experience (11-22 years) was inversely associated with involvement in accidents (OR 0.63; 95% CI 0.40-0.98). An evident relationship was observed between longer professional experience and a reduction in reporting involvement in accidents and near-miss accidents, regardless of age, substance use, working conditions and behavior in traffic. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Fault detection in reciprocating compressor valves under varying load conditions

    NASA Astrophysics Data System (ADS)

    Pichler, Kurt; Lughofer, Edwin; Pichler, Markus; Buchegger, Thomas; Klement, Erich Peter; Huschenbett, Matthias

    2016-03-01

    This paper presents a novel approach for detecting cracked or broken reciprocating compressor valves under varying load conditions. The main idea is that the time frequency representation of vibration measurement data will show typical patterns depending on the fault state. The problem is to detect these patterns reliably. For the detection task, we make a detour via the two dimensional autocorrelation. The autocorrelation emphasizes the patterns and reduces noise effects. This makes it easier to define appropriate features. After feature extraction, classification is done using logistic regression and support vector machines. The method's performance is validated by analyzing real world measurement data. The results will show a very high detection accuracy while keeping the false alarm rates at a very low level for different compressor loads, thus achieving a load-independent method. The proposed approach is, to our best knowledge, the first automated method for reciprocating compressor valve fault detection that can handle varying load conditions.

  20. Relationships of working conditions, health problems and vehicle accidents in bus rapid transit (BRT) drivers.

    PubMed

    Gómez-Ortiz, Viviola; Cendales, Boris; Useche, Sergio; Bocarejo, Juan P

    2018-04-01

    The aim of this study was to estimate accident risk rates and mental health of bus rapid transit (BRT) drivers based on psychosocial risk factors at work leading to increased stress and health problems. A cross-sectional research design utilized a self-report questionnaire completed by 524 BRT drivers. Some working conditions of BRT drivers (lack of social support from supervisors and perceived potential for risk) may partially explain Bogota's BRT drivers' involvement in road accidents. Drivers' mental health problems were associated with higher job strain, less support from co-workers, fewer rewards and greater signal conflict while driving. To prevent bus accidents, supervisory support may need to be increased. To prevent mental health problems, other interventions may be needed such as reducing demands, increasing job control, reducing amount of incoming information, simplifying current signals, making signals less contradictory, and revising rewards. © 2018 Wiley Periodicals, Inc.

  1. Affective learning modulates spatial competition during low-load attentional conditions.

    PubMed

    Lim, Seung-Lark; Padmala, Srikanth; Pessoa, Luiz

    2008-04-01

    It has been hypothesized that the amygdala mediates the processing advantage of emotional items. In the present study, we employed functional magnetic resonance imaging (fMRI) to investigate how fear conditioning affected the visual processing of task-irrelevant faces. We hypothesized that faces previously paired with shock (threat faces) would more effectively vie for processing resources during conditions involving spatial competition. To investigate this question, following conditioning, participants performed a letter-detection task on an array of letters that was superimposed on task-irrelevant faces. Attentional resources were manipulated by having participants perform an easy or a difficult search task. Our findings revealed that threat fearful faces evoked stronger responses in the amygdala and fusiform gyrus relative to safe fearful faces during low-load attentional conditions, but not during high-load conditions. Consistent with the increased processing of shock-paired stimuli during the low-load condition, such stimuli exhibited increased behavioral priming and fMRI repetition effects relative to unpaired faces during a subsequent implicit-memory task. Overall, our results suggest a competition model in which affective significance signals from the amygdala may constitute a key modulatory factor determining the neural fate of visual stimuli. In addition, it appears that such competitive advantage is only evident when sufficient processing resources are available to process the affective stimulus.

  2. Lie construction affects information storage under high memory load condition.

    PubMed

    Liu, Yuqiu; Wang, Chunjie; Jiang, Haibo; He, Hongjian; Chen, Feiyan

    2017-01-01

    Previous studies indicate that lying consumes cognitive resources, especially working memory (WM) resources. Considering the dual functions that WM might play in lying: holding the truth-related information and turning the truth into lies, the present study examined the relationship between the information storage and processing in the lie construction. To achieve that goal, a deception task based on the old/new recognition paradigm was designed, which could manipulate two levels of WM load (low-load task using 4 items and high-load task using 6 items) during the deception process. The analyses based on the amplitude of the contralateral delay activity (CDA), a proved index of the number of representations being held in WM, showed that the CDA amplitude was lower in the deception process than that in the truth telling process under the high-load condition. In contrast, under the low-load condition, no CDA difference was found between the deception and truth telling processes. Therefore, we deduced that the lie construction and information storage compete for WM resources; when the available WM resources cannot meet this cognitive demand, the WM resources occupied by the information storage would be consumed by the lie construction.

  3. Lie construction affects information storage under high memory load condition

    PubMed Central

    Liu, Yuqiu; Wang, Chunjie; Jiang, Haibo; He, Hongjian; Chen, Feiyan

    2017-01-01

    Previous studies indicate that lying consumes cognitive resources, especially working memory (WM) resources. Considering the dual functions that WM might play in lying: holding the truth-related information and turning the truth into lies, the present study examined the relationship between the information storage and processing in the lie construction. To achieve that goal, a deception task based on the old/new recognition paradigm was designed, which could manipulate two levels of WM load (low-load task using 4 items and high-load task using 6 items) during the deception process. The analyses based on the amplitude of the contralateral delay activity (CDA), a proved index of the number of representations being held in WM, showed that the CDA amplitude was lower in the deception process than that in the truth telling process under the high-load condition. In contrast, under the low-load condition, no CDA difference was found between the deception and truth telling processes. Therefore, we deduced that the lie construction and information storage compete for WM resources; when the available WM resources cannot meet this cognitive demand, the WM resources occupied by the information storage would be consumed by the lie construction. PMID:28727794

  4. Some aspects of strategies and solutions in accident prevention.

    PubMed

    Häkkinen, K

    1983-04-01

    Accident prevention measures are traditionally classified into technical, organizational and behavioral solutions. A review of some commonly used strategies for accident prevention illustrates some discrepancies between different approaches and the need to develop more comprehensive strategies. Several factors, including protective efficiency and disadvantages at work, must be taken into account when the solutions are evaluated. Some solutions to prevent load disengagement from cranes were evaluated. Measurements of the pressing force showed that the efficiency of the safety latch of a clamp for plate lifting is inadequate to provide protection under all exceptional lifting conditions and in all situations for which the safety latch is intended. The delay caused by the attachment of a lifting hook equipped with a safety latch was measured. The handling of some of the most reliable and technically safe latches requires additional operations and thereby limits their practical application.

  5. Assessment of Technogenic Accident Risk of Industrial Building Structures

    NASA Astrophysics Data System (ADS)

    Baiburin, D. A.; Baiburin, A. Kh

    2017-11-01

    A methodology for assessing the risk of an industrial building accident was developed taking into account the damage caused by various localization of collapse. Before the beginning of the survey of a facility technical condition, groups including the same type of building structures are selected. Further, assessment is made for the reduction in their load-carrying capacity from the strength and stability conditions taking into account defects. The characteristics of the influence of defects and structural damage on a building safety is the degree of compliance with the standards expressed by the reliability level. Reliability levels assignment is carried out on the basis of calculations, operating experience and inspection of a particular type of structure according to the formalized rules. The risk of collapse according to a separate scenario is calculated for structures that are capable and incapable of causing a progressive ossification. The results of the technique application are based on the analysis of the accident risk at the welding shop “Vysota (Height) 239” of the Chelyabinsk Pipe Rolling Plant.

  6. Probabilistic Approach to Conditional Probability of Release of Hazardous Materials from Railroad Tank Cars during Accidents

    DOT National Transportation Integrated Search

    2009-10-13

    This paper describes a probabilistic approach to estimate the conditional probability of release of hazardous materials from railroad tank cars during train accidents. Monte Carlo methods are used in developing a probabilistic model to simulate head ...

  7. Conditional load and store in a shared memory

    DOEpatents

    Blumrich, Matthias A; Ohmacht, Martin

    2015-02-03

    A method, system and computer program product for implementing load-reserve and store-conditional instructions in a multi-processor computing system. The computing system includes a multitude of processor units and a shared memory cache, and each of the processor units has access to the memory cache. In one embodiment, the method comprises providing the memory cache with a series of reservation registers, and storing in these registers addresses reserved in the memory cache for the processor units as a result of issuing load-reserve requests. In this embodiment, when one of the processor units makes a request to store data in the memory cache using a store-conditional request, the reservation registers are checked to determine if an address in the memory cache is reserved for that processor unit. If an address in the memory cache is reserved for that processor, the data are stored at this address.

  8. Ductile Crack Initiation Criterion with Mismatched Weld Joints Under Dynamic Loading Conditions.

    PubMed

    An, Gyubaek; Jeong, Se-Min; Park, Jeongung

    2018-03-01

    Brittle failure of high toughness steel structures tends to occur after ductile crack initiation/propagation. Damages to steel structures were reported in the Hanshin Great Earthquake. Several brittle failures were observed in beam-to-column connection zones with geometrical discontinuity. It is widely known that triaxial stresses accelerate the ductile fracture of steels. The study examined the effects of geometrical heterogeneity and strength mismatches (both of which elevate plastic constraints due to heterogeneous plastic straining) and loading rate on critical conditions initiating ductile fracture. This involved applying the two-parameter criterion (involving equivalent plastic strain and stress triaxiality) to estimate ductile cracking for strength mismatched specimens under static and dynamic tensile loading conditions. Ductile crack initiation testing was conducted under static and dynamic loading conditions using circumferentially notched specimens (Charpy type) with/without strength mismatches. The results indicated that the condition for ductile crack initiation using the two parameter criterion was a transferable criterion to evaluate ductile crack initiation independent of the existence of strength mismatches and loading rates.

  9. Friction Stir Weld Failure Mechanisms in Aluminum-Armor Structures Under Ballistic Impact Loading Conditions

    DTIC Science & Technology

    2013-01-01

    REPORT Friction Stir Weld Failure Mechanisms in Aluminum -Armor Structures Under Ballistic Impact Loading Conditions 14. ABSTRACT 16. SECURITY...Stir Weld Failure Mechanisms in Aluminum -Armor Structures Under Ballistic Impact Loading Conditions M. Grujicic, B. Pandurangan, A. Arakere, C-F. Yen...K.O. Pedersen, Fracture Mechanisms of Aluminum Alloy AA7075-T651 Under Various Loading Conditions , Int. J. Impact Eng., 2010, 37, p 537–551 24. T

  10. Is muscle coordination affected by loading condition in ballistic movements?

    PubMed

    Giroux, Caroline; Guilhem, Gaël; Couturier, Antoine; Chollet, Didier; Rabita, Giuseppe

    2015-02-01

    This study aimed to investigate the effect of loading on lower limb muscle coordination involved during ballistic squat jumps. Twenty athletes performed ballistic squat jumps on a force platform. Vertical force, velocity, power and electromyographic (EMG) activity of lower limb muscles were recorded during the push-off phase and compared between seven loading conditions (0-60% of the concentric-only maximal repetition). The increase in external load increased vertical force (from 1962 N to 2559 N; P=0.0001), while movement velocity decreased (from 2.5 to 1.6 ms(-1); P=0.0001). EMG activity of tibialis anterior first peaked at 5% of the push-off phase, followed by gluteus maximus (35%), vastus lateralis and soleus (45%), rectus femoris (55%), gastrocnemius lateralis (65%) and semitendinosus (75%). This sequence of activation (P=0.67) and the amplitude of muscle activity (P=0.41) of each muscle were not affected by loading condition. However, a main effect of muscle was observed on these parameters (peak value: P<0.001; peak occurrence: P=0.02) illustrating the specific role of each muscle during the push-off phase. Our findings suggest that muscle coordination is not influenced by external load during a ballistic squat jump. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. 24 CFR 3285.315 - Special snow load conditions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Special snow load conditions. 3285.315 Section 3285.315 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR HOUSING-FEDERAL HOUSING COMMISSIONER, DEPARTMENT OF...

  12. Determination of the boundary conditions of the grinding load in ball mills

    NASA Astrophysics Data System (ADS)

    Sharapov, Rashid R.

    2018-02-01

    The prospects of application in ball mills for grinding cement clinker with inclined partitions are shown. It is noted that ball mills with inclined partitions are more effective. An algorithm is proposed for calculating the power consumed by a ball mill with inclined inter-chamber partitions in which an axial movement of the ball load takes place. The boundary conditions in which the ball load is located are determined. The equations of bounding the grinding load are determined. The behavior of a grinding load is considered in view of the characteristic cross sections. The coordinates of the centers of gravity of the grinding load with a definite step and the shape of the cross sections are determined. It is theoretically shown that grinding load in some parts of the ball mill not only consumes, but also helps to rotate the ball mill. Methods for calculating complex analytical expressions for determining the coordinates of the centers of gravity of the grinding load under the conditions of its longitudinal motion have developed. The carried out researches allow to approach from the general positions to research of behavior of a grinding load in the ball mills equipped with various in-mill devices.

  13. 49 CFR 195.50 - Reporting accidents.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Reporting accidents. 195.50 Section 195.50 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Annual, Accident, and Safety-Related Condition Reporting § 195.50 Reporting accidents. An accident...

  14. 49 CFR 195.50 - Reporting accidents.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Reporting accidents. 195.50 Section 195.50 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Annual, Accident, and Safety-Related Condition Reporting § 195.50 Reporting accidents. An accident...

  15. 10 CFR 50.67 - Accident source term.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... occupancy of the control room under accident conditions without personnel receiving radiation exposures in... 10 Energy 1 2014-01-01 2014-01-01 false Accident source term. 50.67 Section 50.67 Energy NUCLEAR... Conditions of Licenses and Construction Permits § 50.67 Accident source term. (a) Applicability. The...

  16. 10 CFR 50.67 - Accident source term.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... occupancy of the control room under accident conditions without personnel receiving radiation exposures in... 10 Energy 1 2012-01-01 2012-01-01 false Accident source term. 50.67 Section 50.67 Energy NUCLEAR... Conditions of Licenses and Construction Permits § 50.67 Accident source term. (a) Applicability. The...

  17. 10 CFR 50.67 - Accident source term.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... occupancy of the control room under accident conditions without personnel receiving radiation exposures in... 10 Energy 1 2010-01-01 2010-01-01 false Accident source term. 50.67 Section 50.67 Energy NUCLEAR... Conditions of Licenses and Construction Permits § 50.67 Accident source term. (a) Applicability. The...

  18. 10 CFR 50.67 - Accident source term.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... occupancy of the control room under accident conditions without personnel receiving radiation exposures in... 10 Energy 1 2013-01-01 2013-01-01 false Accident source term. 50.67 Section 50.67 Energy NUCLEAR... Conditions of Licenses and Construction Permits § 50.67 Accident source term. (a) Applicability. The...

  19. 10 CFR 50.67 - Accident source term.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... occupancy of the control room under accident conditions without personnel receiving radiation exposures in... 10 Energy 1 2011-01-01 2011-01-01 false Accident source term. 50.67 Section 50.67 Energy NUCLEAR... Conditions of Licenses and Construction Permits § 50.67 Accident source term. (a) Applicability. The...

  20. Effects of heat and moisture on fiberglass composite materials in the load carrying and non-load carrying conditions

    NASA Astrophysics Data System (ADS)

    McClurg, Jack Albert

    The objective set forth in this study was to thoroughly document the effects of heat, moisture, and loading conditions on a variety of pultruded unidirectional fiberglass reinforced composite materials. This study incorporated the use of two environmental control chambers and two water immersion tanks in order to provide the necessary range of environmental exposure conditions. A set of specially designed stainless steel loading fixtures was produced in order to introduce the factor of external loading of the specimens while exposed to the predetermined environmental condition and how that would affect the mechanical and physical properties in question. The properties of interest were the flexural strength (determined using the three-point flexural bending method), flexural modulus (determined using the three-point flexural bending method), and glass transition temperature of the material (determined using differential scanning calorimetry). Other data that was noted during the conditioning and testing of the specimens was the break type (flexural tension, compression, shear, etc...), the change in dimensions (prior to exposure vs. after exposure), and the change in weight (prior to exposure vs. after exposure). Using all of the information that was obtained from this study, a more detailed understanding of how and why fiberglass reinforced materials react the way they do when exposed to moisture and elevated temperature was drawn. This study is different from most others in that it explores the interactions of three independent variables (heat, moisture, and loading condition) on three different fiberglass reinforced composite systems (epoxy, vinylester, and polyester resin).

  1. Versatile Oxide Films Protect FeCrAl Alloys Under Normal Operation and Accident Conditions in Light Water Power Reactors

    NASA Astrophysics Data System (ADS)

    Rebak, Raul B.

    2018-02-01

    The US has currently a fleet of 99 nuclear power light water reactors which generate approximately 20% of the electricity consumed in the country. Near 90% of the reactors are at least 30 years old. There are incentives to make the existing reactors safer by using accident tolerant fuels (ATF). Compared to the standard UO2-zirconium-based system, ATF need to tolerate loss of active cooling in the core for a considerably longer time while maintaining or improving the fuel performance during normal operation conditions. Ferritic iron-chromium-aluminum (FeCrAl) alloys have been identified as an alternative to replace current zirconium alloys. They contain Fe (base) + 10-22 Cr + 4-6 Al and may contain smaller amounts of other elements such as molybdenum and traces of others. FeCrAl alloys offer outstanding resistance to attack by superheated steam by developing an alumina oxide on the surface in case of a loss of coolant accident like at Fukushima. FeCrAl alloys also perform well under normal operation conditions both in boiling water reactors and pressurized water reactors because they are protected by a thin oxide rich in chromium. Under normal operation condition, the key element is Cr and under accident conditions it is Al.

  2. 49 CFR 195.54 - Accident reports.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Accident reports. 195.54 Section 195.54... PIPELINE Annual, Accident, and Safety-Related Condition Reporting § 195.54 Accident reports. (a) Each operator that experiences an accident that is required to be reported under § 195.50 shall as soon as...

  3. Bridge condition assessment and load rating using dynamic response.

    DOT National Transportation Integrated Search

    2014-07-01

    This report describes a method for the overall condition assessment and load rating of prestressed box beam : (PSBB) bridges based on their dynamic response collected through wireless sensor networks (WSNs). Due to a : large inventory of deficient an...

  4. Assessment of potential doses to workers during postulated accident conditions at the Waste Isolation Pilot Plant

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

    Hoover, M.D.; Farrell, R.F.; Newton, G.J.

    1995-12-01

    The recent 1995 WIPP Safety Analysis Report (SAR) Update provided detailed analyses of potential radiation doses to members of the public at the site boundary during postulated accident scenarios at the U.S. Department of Energy`s Waste Isolation Pilot Plant (WIPP). The SAR Update addressed the complete spectrum of potential accidents associated with handling and emplacing transuranic waste at WIPP, including damage to waste drums from fires, punctures, drops, and other disruptions. The report focused on the adequacy of the multiple layers of safety practice ({open_quotes}defense-in-depth{close_quotes}) at WIPP, which are designed to (1) reduce the likelihood of accidents and (2) limitmore » the consequences of those accidents. The safeguards which contribute to defense-in-depth at WIPP include a substantial array of inherent design features, engineered controls, and administrative procedures. The SAR Update confirmed that the defense-in-depth at WIPP is adequate to assure the protection of the public and environment. As a supplement to the 1995 SAR Update, we have conducted additional analyses to confirm that these controls will also provide adequate protection to workers at the WIPP. The approaches and results of the worker dose assessment are summarized here. In conformance with the guidance of DOE Standard 3009-94, we emphasize that use of these evaluation guidelines is not intended to imply that these numbers constitute acceptable limits for worker exposures under accident conditions. However, in conjunction with the extensive safety assessment in the 1995 SAR Update, these results indicate that the Carlsbad Area Office strategy for the assessment of hazards and accidents assures the protection of workers, members of the public, and the environment.« less

  5. Occupational accidents among mototaxi drivers.

    PubMed

    Amorim, Camila Rego; de Araújo, Edna Maria; de Araújo, Tânia Maria; de Oliveira, Nelson Fernandes

    2012-03-01

    The use of motorcycles as a means of work has contributed to the increase in traffic accidents, in particular, mototaxi accidents. The aim of this study was to estimate and characterize the incidence of occupational accidents among the mototaxis registered in Feira de Santana, BA. This is a cross-sectional study with descriptive and census data. Of the 300 professionals registered at the Municipal Transportation Service, 267 professionals were interviewed through a structured questionnaire. Then, a descriptive analysis was conducted and the incidence of accidents was estimated based on the variables studied. Relative risks were calculated and statistical significance was determined using the chi-square test and Fisher's exact test, considering p < 0.05. Logistic regression was used in order to perform simultaneous adjustment of variables. Occupational accidents were observed in 10.5% of mototaxis. There were mainly minor injuries (48.7%), 27% of them requiring leaves of absence from work. There was an association between the days of work per week, fatigue in lower limbs and musculoskeletal complaints, and accidents. Knowledge of the working conditions and accidents involved in this activity can be of great importance for the adoption of traffic education policies, and to help prevent accidents by improving the working conditions and lives of these professionals.

  6. Contributing factors in construction accidents.

    PubMed

    Haslam, R A; Hide, S A; Gibb, A G F; Gyi, D E; Pavitt, T; Atkinson, S; Duff, A R

    2005-07-01

    This overview paper draws together findings from previous focus group research and studies of 100 individual construction accidents. Pursuing issues raised by the focus groups, the accident studies collected qualitative information on the circumstances of each incident and the causal influences involved. Site based data collection entailed interviews with accident-involved personnel and their supervisor or manager, inspection of the accident location, and review of appropriate documentation. Relevant issues from the site investigations were then followed up with off-site stakeholders, including designers, manufacturers and suppliers. Levels of involvement of key factors in the accidents were: problems arising from workers or the work team (70% of accidents), workplace issues (49%), shortcomings with equipment (including PPE) (56%), problems with suitability and condition of materials (27%), and deficiencies with risk management (84%). Employing an ergonomics systems approach, a model is proposed, indicating the manner in which originating managerial, design and cultural factors shape the circumstances found in the work place, giving rise to the acts and conditions which, in turn, lead to accidents. It is argued that attention to the originating influences will be necessary for sustained improvement in construction safety to be achieved.

  7. Assessment of Wind Turbine Component Loads Under Yaw-Offset Conditions

    DOE PAGES

    Damiani, Rick R.; Dana, Scott; Annoni, Jennifer; ...

    2018-04-13

    Renewed interest in yaw control for wind turbine and power plants for wake redirection and load mitigation demands a clear understanding of the effects of running with skewed inflow. In this paper, we investigate the physics of yawed operations, building up the complexity from a simplified analytical treatment to more complex aeroelastic simulations. Results in terms of damage equivalent loads (DELs) and extreme loads under operating, misaligned conditions are compared to data collected from an instrumented, utility-scale wind turbine. The analysis shows that multiple factors are responsible for the DELs of the various components, and that airfoil aerodynamics, elastic characteristicsmore » of the rotor, and turbulence intensities are the primary drivers. Both fatigue and extreme loads are observed to have relatively complex trends with yaw offsets, which can change depending on the wind-speed regime. As a result, good agreement is found between predicted and measured trends for both fatigue and ultimate loads.« less

  8. Assessment of Wind Turbine Component Loads Under Yaw-Offset Conditions

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

    Damiani, Rick R.; Dana, Scott; Annoni, Jennifer

    Renewed interest in yaw control for wind turbine and power plants for wake redirection and load mitigation demands a clear understanding of the effects of running with skewed inflow. In this paper, we investigate the physics of yawed operations, building up the complexity from a simplified analytical treatment to more complex aeroelastic simulations. Results in terms of damage equivalent loads (DELs) and extreme loads under operating, misaligned conditions are compared to data collected from an instrumented, utility-scale wind turbine. The analysis shows that multiple factors are responsible for the DELs of the various components, and that airfoil aerodynamics, elastic characteristicsmore » of the rotor, and turbulence intensities are the primary drivers. Both fatigue and extreme loads are observed to have relatively complex trends with yaw offsets, which can change depending on the wind-speed regime. As a result, good agreement is found between predicted and measured trends for both fatigue and ultimate loads.« less

  9. Data characteristic analysis of air conditioning load based on fast Fourier transform

    NASA Astrophysics Data System (ADS)

    Li, Min; Zhang, Yanchi; Xie, Da

    2018-04-01

    With the development of economy and the improvement of people's living standards, air conditioning equipment is more and more popular. The influence of air conditioning load for power grid is becoming more and more serious. In this context it is necessary to study the characteristics of air conditioning load. This paper analyzes the data of air conditioning power consumption in an office building. The data is used for Fast Fourier Transform by data analysis software. Then a series of maps are drawn for the transformed data. The characteristics of each map were analyzed separately. The hidden rules of these data are mined from the angle of frequency domain. And these rules are hard to find in the time domain.

  10. Trait Anxiety and Perceptual Load as Determinants of Emotion Processing in a Fear Conditioning Paradigm

    PubMed Central

    Fox, Elaine; Yates, Alan; Ashwin, Chris

    2012-01-01

    The impact of trait anxiety and perceptual load on selective attention was examined in a fear conditioning paradigm. A fear-conditioned angry face (CS+), an unconditioned angry face (CS−), or an unconditioned face with a neutral or happy expression were used in distractor interference and attentional probe tasks. In Experiments 1 and 2, participants classified centrally presented letters under two conditions of perceptual load. When perceptual load was high, distractors had no effect on selective attention, even with aversive conditioning. However, when perceptual load was low, strong response interference effects for CS+ face distractors were found for low trait-anxious participants. Across both experiments, this enhanced distractor interference reversed to strong facilitation effects for those reporting high trait anxiety. Thus, high trait-anxious participants were faster, rather than slower, when ignoring CS+ distractors. Using an attentional probe task in Experiment 3, it was found that fear conditioning resulted in strong attentional avoidance in a high trait-anxious group, which contrasted with enhanced vigilance in a low trait-anxious group. These results demonstrate that the impact of fear conditioning on attention is modulated by individual variation in trait anxiety when perceptual load is low. Fear conditioning elicits an avoidance of threat-relevant stimuli in high trait-anxious participants. PMID:21875186

  11. Estimated Muscle Loads During Squat Exercise in Microgravity Conditions

    NASA Technical Reports Server (NTRS)

    Fregly, Christopher D.; Kim, Brandon T.; Li, Zhao; DeWitt, John K.; Fregly, Benjamin J.

    2012-01-01

    Loss of muscle mass in microgravity is one of the primary factors limiting long-term space flight. NASA researchers have developed a number of exercise devices to address this problem. The most recent is the Advanced Resistive Exercise Device (ARED), which is currently used by astronauts on the International Space Station (ISS) to emulate typical free-weight exercises in microgravity. ARED exercise on the ISS is intended to reproduce Earth-level muscle loads, but the actual muscle loads produced remain unknown as they cannot currently be measured directly. In this study we estimated muscle loads experienced during squat exercise on ARED in microgravity conditions representative of Mars, the moon, and the ISS. The estimates were generated using a subject-specific musculoskeletal computer model and ARED exercise data collected on Earth. The results provide insight into the capabilities and limitations of the ARED machine.

  12. Effect of load carriage and natural terrain conditions on cognitive performance in desert environments.

    PubMed

    Bhattacharyya, Debojyoti; Pal, Madhusudan; Chatterjee, Tirthankar; Majumdar, Dhurjati

    2017-10-01

    Correct decision making is a critical component of cognitive performance of a soldier, which may be influenced by the load carriage and terrain conditions during their deployment in desert environment. The present study was aimed to investigate the effects of loads and terrain conditions on the cognitive performance in a group of twelve healthy heat acclimatized infantry soldiers under natural desert environment. The soldiers participated in a 10min walking trial during carrying no load and also carrying 10.7, 21.4 and 30kg at two terrain conditions viz., sandy and hard. We studied attention, memory and executive function, which are having immense functional importance in military operations. Standardized cognitive test battery was applied to the participants after carrying each magnitude of load at each terrain. Baseline cognitive performance was recorded on a separate day and was compared with the performances recorded after the load carriage trials. An attempt was made to reveal the relationship between physiological workload (relative workload) and cognitive performance at the point of completion of load carriage trials. Load, terrains and load×terrain interaction did not produce any significant effect (p>0.05) on the cognitive performance. Attention and relative workload were found significantly correlated at hard terrain under no load, 21.4kg and 30kg. Significant correlation was found between executive function and relative workload at hard terrain under no load. Carrying upto 30kg load for 10min at 3.5-4kmph walking speed resulted in improvement in attention at sandy terrain, decrement in memory at both sandy and hard terrains and improvement in executive function at sandy terrain. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Development of the Rules Governing the Strength of Airplanes. Part I : German Loading Conditions up to 1926

    NASA Technical Reports Server (NTRS)

    Kussner, H G; Thalau, Karl

    1933-01-01

    Load factors and loading conditions are presented for German aircraft. Loading conditions under various stress factors are presented along with a breakdown of individual aircraft components such as landing gear, wings, etc.

  14. Acute stress reactions after submarine accidents.

    PubMed

    Eid, Jarle; Johnsen, Bjørn Helge

    2002-05-01

    The aim of the present study was to explore contextual and individual factors associated with acute stress reactions in three Norwegian submarine crews exposed to different significant peacetime maneuver accidents. Approximately 2 to 3 weeks after the accidents, crew members completed the Coping Style Questionnaire, the General Health Questionnaire, the Impact of Event Scale, and the Post-Traumatic Symptom Scale. Although exposed subjects (N = 47) revealed more posttraumatic stress symptoms than nonexposed crew members on shore leave (N = 7), they showed less acute stress reactions than survivors from a surface ship accident in the Norwegian Navy. Inspection of individual cases revealed that 4% of the exposed submariners showed high loads of acute stress symptoms. Unit cohesion and habitual coping styles emerged as resilience factors, whereas previous exposure to critical incidents and personal experience of not coping in the accident situation emerged as vulnerability factors, explaining 32% of the acute stress reactions reported by submarine crew members.

  15. 49 CFR 801.32 - Accident reports.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Accident reports. 801.32 Section 801.32 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL TRANSPORTATION SAFETY BOARD PUBLIC AVAILABILITY OF INFORMATION Accident Investigation Records § 801.32 Accident reports. (a) The NTSB will report the facts, conditions, and...

  16. Trait anxiety and perceptual load as determinants of emotion processing in a fear conditioning paradigm.

    PubMed

    Fox, Elaine; Yates, Alan; Ashwin, Chris

    2012-04-01

    The impact of trait anxiety and perceptual load on selective attention was examined in a fear conditioning paradigm. A fear-conditioned angry face (CS+), an unconditioned angry face (CS-), or an unconditioned face with a neutral or happy expression were used in distractor interference and attentional probe tasks. In Experiments 1 and 2, participants classified centrally presented letters under two conditions of perceptual load. When perceptual load was high, distractors had no effect on selective attention, even with aversive conditioning. However, when perceptual load was low, strong response interference effects for CS+ face distractors were found for low trait-anxious participants. Across both experiments, this enhanced distractor interference reversed to strong facilitation effects for those reporting high trait anxiety. Thus, high trait-anxious participants were faster, rather than slower, when ignoring CS+ distractors. Using an attentional probe task in Experiment 3, it was found that fear conditioning resulted in strong attentional avoidance in a high trait-anxious group, which contrasted with enhanced vigilance in a low trait-anxious group. These results demonstrate that the impact of fear conditioning on attention is modulated by individual variation in trait anxiety when perceptual load is low. Fear conditioning elicits an avoidance of threat-relevant stimuli in high trait-anxious participants. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

  17. 49 CFR 178.345-8 - Accident damage protection.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... accidental loss of lading. The device must break at no more than 70 percent of the load that would be... major radius of the tank shell. The device must break at no more than 70 percent of the load that would... for the loss of lading due to an accident. (1) Any dome, sump, or washout cover plate projecting from...

  18. 14 CFR 29.497 - Ground loading conditions: landing gear with tail wheels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... designed for loading conditions as prescribed in this section. (b) Level landing attitude with only the forward wheels contacting the ground. In this attitude— (1) The vertical loads must be applied under §§ 29... be resisted by angular inertia forces. (c) Level landing attitude with all wheels contacting the...

  19. 14 CFR 27.497 - Ground loading conditions: landing gear with tail wheels.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... designed for loading conditions as prescribed in this section. (b) Level landing attitude with only the forward wheels contacting the ground. In this attitude— (1) The vertical loads must be applied under §§ 27... be resisted by angular inertia forces. (c) Level landing attitude with all wheels contacting the...

  20. The effects of posterior cruciate ligament deficiency on posterolateral corner structures under gait- and squat-loading conditions

    PubMed Central

    Kang, K-T.; Koh, Y-G.; Jung, M.; Nam, J-H.; Son, J.; Lee, Y.H.

    2017-01-01

    Objectives The aim of the current study was to analyse the effects of posterior cruciate ligament (PCL) deficiency on forces of the posterolateral corner structure and on tibiofemoral (TF) and patellofemoral (PF) contact force under dynamic-loading conditions. Methods A subject-specific knee model was validated using a passive flexion experiment, electromyography data, muscle activation, and previous experimental studies. The simulation was performed on the musculoskeletal models with and without PCL deficiency using a novel force-dependent kinematics method under gait- and squat-loading conditions, followed by probabilistic analysis for material uncertain to be considered. Results Comparison of predicted passive flexion, posterior drawer kinematics and muscle activation with experimental measurements showed good agreement. Forces of the posterolateral corner structure, and TF and PF contact forces increased with PCL deficiency under gait- and squat-loading conditions. The rate of increase in PF contact force was the greatest during the squat-loading condition. The TF contact forces increased on both medial and lateral compartments during gait-loading conditions. However, during the squat-loading condition, the medial TF contact force tended to increase, while the lateral TF contact forces decreased. The posterolateral corner structure, which showed the greatest increase in force with deficiency of PCL under both gait- and squat-loading conditions, was the popliteus tendon (PT). Conclusion PCL deficiency is a factor affecting the variability of force on the PT in dynamic-loading conditions, and it could lead to degeneration of the PF joint. Cite this article: K-T. Kang, Y-G. Koh, M. Jung, J-H. Nam, J. Son, Y.H. Lee, S-J. Kim, S-H. Kim. The effects of posterior cruciate ligament deficiency on posterolateral corner structures under gait- and squat-loading conditions: A computational knee model. Bone Joint Res 2017;6:31–42. DOI: 10.1302/2046-3758.61.BJR-2016-0184.R1

  1. Computational characterization of fracture healing under reduced gravity loading conditions.

    PubMed

    Gadomski, Benjamin C; Lerner, Zachary F; Browning, Raymond C; Easley, Jeremiah T; Palmer, Ross H; Puttlitz, Christian M

    2016-07-01

    The literature is deficient with regard to how the localized mechanical environment of skeletal tissue is altered during reduced gravitational loading and how these alterations affect fracture healing. Thus, a finite element model of the ovine hindlimb was created to characterize the local mechanical environment responsible for the inhibited fracture healing observed under experimental simulated hypogravity conditions. Following convergence and verification studies, hydrostatic pressure and strain within a diaphyseal fracture of the metatarsus were evaluated for models under both 1 and 0.25 g loading environments and compared to results of a related in vivo study. Results of the study suggest that reductions in hydrostatic pressure and strain of the healing fracture for animals exposed to reduced gravitational loading conditions contributed to an inhibited healing process, with animals exposed to the simulated hypogravity environment subsequently initiating an intramembranous bone formation process rather than the typical endochondral ossification healing process experienced by animals healing in a 1 g gravitational environment. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1206-1215, 2016. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  2. Underreporting of maritime accidents to vessel accident databases.

    PubMed

    Hassel, Martin; Asbjørnslett, Bjørn Egil; Hole, Lars Petter

    2011-11-01

    Underreporting of maritime accidents is a problem not only for authorities trying to improve maritime safety through legislation, but also to risk management companies and other entities using maritime casualty statistics in risk and accident analysis. This study collected and compared casualty data from 01.01.2005 to 31.12.2009, from IHS Fairplay and the maritime authorities from a set of nations. The data was compared to find common records, and estimation of the true number of occurred accidents was performed using conditional probability given positive dependency between data sources, several variations of the capture-recapture method, calculation of best case scenario assuming perfect reporting, and scaling up a subset of casualty information from a marine insurance statistics database. The estimated upper limit reporting performance for the selected flag states ranged from 14% to 74%, while the corresponding estimated coverage of IHS Fairplay ranges from 4% to 62%. On average the study results document that the number of unreported accidents makes up roughly 50% of all occurred accidents. Even in a best case scenario, only a few flag states come close to perfect reporting (94%). The considerable scope of underreporting uncovered in the study, indicates that users of statistical vessel accident data should assume a certain degree of underreporting, and adjust their analyses accordingly. Whether to use correction factors, a safety margin, or rely on expert judgment, should be decided on a case by case basis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Temporal Change of Environmental Contamination Conditions in Five Years after the Fukushima Accident

    NASA Astrophysics Data System (ADS)

    Saito, Kimiaki

    2017-09-01

    The temporal change of environmental contamination conditions after the Fukushima accident have been clarified based on large-scale environmental monitoring data repeatedly obtained in the 80 km zone. The decreasing tendency of air dose rates was confirmed to obviously depend on land uses. In human-related diverse environments the air dose rates have decreased much faster than the physical decay of radiocesium. The horizontal movement of radiocesium in undisturbed fields were found to be generally quite small, though it has gradually penetrated into the deeper parts of the ground.

  4. Force Outputs during Squats Performed Using a Rotational Inertia Device under Stable versus Unstable Conditions with Different Loads.

    PubMed

    Vázquez-Guerrero, Jairo; Moras, Gerard; Baeza, Jennifer; Rodríguez-Jiménez, Sergio

    2016-01-01

    The purpose of the study was to compare the force outputs achieved during a squat exercise using a rotational inertia device in stable versus unstable conditions with different loads and in concentric and eccentric phases. Thirteen male athletes (mean ± SD: age 23.7 ± 3.0 years, height 1.80 ± 0.08 m, body mass 77.4 ± 7.9 kg) were assessed while squatting, performing one set of three repetitions with four different loads under stable and unstable conditions at maximum concentric effort. Overall, there were no significant differences between the stable and unstable conditions at each of the loads for any of the dependent variables. Mean force showed significant differences between some of the loads in stable and unstable conditions (P < 0.010) and peak force output differed between all loads for each condition (P < 0.045). Mean force outputs were greater in the concentric than in the eccentric phase under both conditions and with all loads (P < 0.001). There were no significant differences in peak force between concentric and eccentric phases at any load in either stable or unstable conditions. In conclusion, squatting with a rotational inertia device allowed the generation of similar force outputs under stable and unstable conditions at each of the four loads. The study also provides empirical evidence of the different force outputs achieved by adjusting load conditions on the rotational inertia device when performing squats, especially in the case of peak force. Concentric force outputs were significantly higher than eccentric outputs, except for peak force under both conditions. These findings support the use of the rotational inertia device to train the squatting exercise under unstable conditions for strength and conditioning trainers. The device could also be included in injury prevention programs for muscle lesions and ankle and knee joint injuries.

  5. Force Outputs during Squats Performed Using a Rotational Inertia Device under Stable versus Unstable Conditions with Different Loads

    PubMed Central

    Vázquez-Guerrero, Jairo; Moras, Gerard

    2016-01-01

    The purpose of the study was to compare the force outputs achieved during a squat exercise using a rotational inertia device in stable versus unstable conditions with different loads and in concentric and eccentric phases. Thirteen male athletes (mean ± SD: age 23.7 ± 3.0 years, height 1.80 ± 0.08 m, body mass 77.4 ± 7.9 kg) were assessed while squatting, performing one set of three repetitions with four different loads under stable and unstable conditions at maximum concentric effort. Overall, there were no significant differences between the stable and unstable conditions at each of the loads for any of the dependent variables. Mean force showed significant differences between some of the loads in stable and unstable conditions (P < 0.010) and peak force output differed between all loads for each condition (P < 0.045). Mean force outputs were greater in the concentric than in the eccentric phase under both conditions and with all loads (P < 0.001). There were no significant differences in peak force between concentric and eccentric phases at any load in either stable or unstable conditions. In conclusion, squatting with a rotational inertia device allowed the generation of similar force outputs under stable and unstable conditions at each of the four loads. The study also provides empirical evidence of the different force outputs achieved by adjusting load conditions on the rotational inertia device when performing squats, especially in the case of peak force. Concentric force outputs were significantly higher than eccentric outputs, except for peak force under both conditions. These findings support the use of the rotational inertia device to train the squatting exercise under unstable conditions for strength and conditioning trainers. The device could also be included in injury prevention programs for muscle lesions and ankle and knee joint injuries. PMID:27111766

  6. THE RELATIONSHIP OF IMPAIRED PHYSICAL CONDITION TO ACCIDENTS

    PubMed Central

    Farnum, C. G.

    1916-01-01

    Doctor Farnum points out the value of coöperation between medical and safety departments with an object of fitting the man to the job for which he is physically fit, a means of reducing accidents. This paper tells what one company has done. PMID:18009454

  7. Effects of vegetation and sewage load on mangrove crab condition using experimental mesocosms

    NASA Astrophysics Data System (ADS)

    Amaral, Valter; Penha-Lopes, Gil; Paula, José

    2009-09-01

    Constructed wetlands, especially mangroves, have been studied for their usefulness in sewage treatment but the effects of mangrove vegetation and a sewage load on mangrove macrofauna have been given little attention. Ocypodid crabs are important components of mangrove forests and constitute good bioindicators of the functioning of the ecosystem as a whole. In constructed mangrove mesocosms, three vegetation treatments (bare substratum, and Avicennia marina and Rhizophora mucronata seedlings) were subjected to 0, 20, 60 and 100% sewage loads from a nearby hotel. The physiological condition of introduced Uca annulipes and Uca inversa was evaluated in terms of their RNA/DNA ratio after one, five and twelve months, and used as an indicator of ecological function in the system. Crab condition in 0% sewage load was similar to that of wild crabs throughout, suggesting no significant effects of the mesocosms on their RNA/DNA ratio. Overall, both species coped well with the administered sewage loads, suggesting good ecological function in the system. Both species manifested similar patterns in RNA/DNA ratio, being more affected by seasonal fluctuations than by sewage load and vegetation presence and type. Higher RNA/DNA ratios were recorded in the long compared to the short rainy season. Sewage enhanced crab condition in the bare substratum and R. mucronata treatments, especially after one year, probably as a result of enhanced food availability. Uca inversa may be more sensitive to sewage pollution than U. annulipes. In A. marina, no difference in crab condition was observed between sewage loads, and this mangrove yielded the best reduction in sewage impacts. Our results support the usefulness of constructed mangrove areas in sewage treatment, especially if planted with A. marina and inhabited by physiologically healthy ocypodid crabs to enhance the system's performance.

  8. Post carbon removal nitrifying MBBR operation at high loading and exposure to starvation conditions.

    PubMed

    Young, Bradley; Delatolla, Robert; Kennedy, Kevin; LaFlamme, Edith; Stintzi, Alain

    2017-09-01

    This study investigates the performance of MBBR nitrifying biofilm post carbon removal at high loading and starvation conditions. The nitrifying MBBR, treating carbon removal lagoon effluent, achieved a maximum SARR of 2.13gN/m 2 d with complete conversion of ammonia to nitrate. The results also show the MBBR technology is capable of maintaining a stable biofilm under starvation conditions in systems that nitrify intermittently. The biomass exhibited a higher live fraction of total cells in the high loaded reactors (73-100%) as compared to the reactors operated in starvation condition (26-82%). For both the high loaded and starvation condition, the microbial communities significantly changed with time of operation. The nitrifying community, however, remained steady with the family Nitrosomonadacea as the primary AOBs and Nitrospira as the primary NOB. During starvation conditions, the relative abundance of AOBs decreased and Nitrospira increased corresponding to an NOB/AOB ratio of 5.2-12.1. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Investigation of shipping accident injury severity and mortality.

    PubMed

    Weng, Jinxian; Yang, Dong

    2015-03-01

    Shipping movements are operated in a complex and high-risk environment. Fatal shipping accidents are the nightmares of seafarers. With ten years' worldwide ship accident data, this study develops a binary logistic regression model and a zero-truncated binomial regression model to predict the probability of fatal shipping accidents and corresponding mortalities. The model results show that both the probability of fatal accidents and mortalities are greater for collision, fire/explosion, contact, grounding, sinking accidents occurred in adverse weather conditions and darkness conditions. Sinking has the largest effects on the increment of fatal accident probability and mortalities. The results also show that the bigger number of mortalities is associated with shipping accidents occurred far away from the coastal area/harbor/port. In addition, cruise ships are found to have more mortalities than non-cruise ships. The results of this study are beneficial for policy-makers in proposing efficient strategies to prevent fatal shipping accidents. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Risk Assessment of Heating, Ventilating, and Air-Conditioning Strategies in Low-Load Homes

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

    Poerschke, Andrew

    2016-02-17

    "Modern, energy efficient homes conforming to the Zero Energy Ready Home standard face the challenge of meeting high customer expectations for comfort. Traditional heating, ventilation, and air conditioning (HVAC) sizing and control strategies may be insufficient to adequately condition each zone due to unique load patterns in each room caused by a number of factors. These factors include solar heat gains, occupant-related gains, and gains associated with appliances and electronics. Because of shrinking shell loads, these intermittent factors are having an increasingly significant impact on the thermal load in each zone. Consequently, occupant comfort can be compromised. To evaluate themore » impact of climate and house geometry, as well as HVAC system and control strategies on comfort conditions, IBACOS analyzed the results of 99 TRNSYS multiple-zone simulations. The results of this analysis indicate that for simple-geometry and single-story plans, a single zone and thermostat can adequately condition the entire house. Demanding house geometry and houses with multiple stories require the consideration of multiple thermostats and multiple zones.« less

  11. 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.

  12. Characteristics of worker accidents on NYSDOT construction projects.

    PubMed

    Mohan, Satish; Zech, Wesley C

    2005-01-01

    This paper aims at providing cost-effective safety measures to protect construction workers in highway work zones, based on real data. Two types of accidents that occur in work zones were: (a) construction work area accidents, and (b) traffic accidents involving construction worker(s). A detailed analysis of work zone accidents involving 36 fatalities and 3,055 severe injuries to construction workers on New York State Department of Transportation (NYSDOT) construction projects from 1990 to 2001 established that five accident types: (a) Struck/Pinned by Large Equipment, (b) Trip or Fall (elevated), (c) Contact w/Electrical or Gas Utility, (d) Struck-by Moving/Falling Load, and (e) Crane/Lift Device Failure accounted for nearly 96% of the fatal accidents, nearly 63% of the hospital-level injury accidents, and nearly 91% of the total costs. These construction work area accidents had a total cost of $133.8 million. Traffic accidents that involve contractors' employees were also examined. Statistical analyses of the traffic accidents established that five traffic accident types: (a) Work Space Intrusion, (b) Worker Struck-by Vehicle Inside Work Space, (c) Flagger Struck-by Vehicle, (d) Worker Struck-by Vehicle Entering/Exiting Work Space, and (e) Construction Equipment Struck-by Vehicle Inside Work Space accounted for nearly 86% of the fatal, nearly 70% of the hospital-level injury and minor injury traffic accidents, and $45.4 million (79.4%) of the total traffic accident costs. The results of this paper provide real statistics on construction worker related accidents reported on construction work zones. Potential preventions based on real statistics have also been suggested. The ranking of accident types, both within the work area as well as in traffic, will guide the heavy highway contractor and owner agencies in identifying the most cost effective safety preventions.

  13. Load monitoring of aerospace structures utilizing micro-electro-mechanical systems for static and quasi-static loading conditions

    NASA Astrophysics Data System (ADS)

    Martinez, M.; Rocha, B.; Li, M.; Shi, G.; Beltempo, A.; Rutledge, R.; Yanishevsky, M.

    2012-11-01

    The National Research Council Canada (NRC) has worked on the development of structural health monitoring (SHM) test platforms for assessing the performance of sensor systems for load monitoring applications. The first SHM platform consists of a 5.5 m cantilever aluminum beam that provides an optimal scenario for evaluating the ability of a load monitoring system to measure bending, torsion and shear loads. The second SHM platform contains an added level of structural complexity, by consisting of aluminum skins with bonded/riveted stringers, typical of an aircraft lower wing structure. These two load monitoring platforms are well characterized and documented, providing loading conditions similar to those encountered during service. In this study, a micro-electro-mechanical system (MEMS) for acquiring data from triads of gyroscopes, accelerometers and magnetometers is described. The system was used to compute changes in angles at discrete stations along the platforms. The angles obtained from the MEMS were used to compute a second, third or fourth order degree polynomial surface from which displacements at every point could be computed. The use of a new Kalman filter was evaluated for angle estimation, from which displacements in the structure were computed. The outputs of the newly developed algorithms were then compared to the displacements obtained from the linear variable displacement transducers connected to the platforms. The displacement curves were subsequently post-processed either analytically, or with the help of a finite element model of the structure, to estimate strains and loads. The estimated strains were compared with baseline strain gauge instrumentation installed on the platforms. This new approach for load monitoring was able to provide accurate estimates of applied strains and shear loads.

  14. Structural Impact of Construction Loads

    DOT National Transportation Integrated Search

    2012-08-01

    Numerous bridge construction accidents have occurred across the country because of construction loadings, which are an underemphasized : topic in many DOT specifications and design manuals. Bridge girders are least stable when they are subjected to c...

  15. Structural Impact of Construction Loads

    DOT National Transportation Integrated Search

    2012-08-01

    Numerous bridge construction accidents have occurred across the country because of construction loadings, which are an underemphasized topic in many DOT specifications and design manuals. Bridge girders are least stable when they are subjected to con...

  16. Effects of Simulated Functional Loading Conditions on Dentin, Composite, and Laminate Structures

    PubMed Central

    Walker, Mary P.; Teitelbaum, Heather K.; Eick, J. David; Williams, Karen B.

    2008-01-01

    Use of composite restorations continues to increase, tempered by more potential problems when placed in posterior dentition. Thus, it is essential to understand how these materials function under stress-bearing clinical conditions. Since mastication is difficult to replicate in the laboratory, cyclic loading is frequently used within in vitro evaluations but often employs traditional fatigue testing, which typically does not simulate occlusal loading because higher stresses and loading frequencies are used, so failure mechanisms may be different. The present investigation utilized relevant parameters (specimen size; loading frequency) to assess the effects of cyclic loading on flexural mechanical properties and fracture morphology of (coronal) dentin, composite, and dentin-adhesive-composite “laminate” structures. Incremental monitoring of flexural modulus on individual beams over 60,000 loading cycles revealed a gradual increase across materials; post-hoc comparisons indicated statistical significance only for 1 versus 60k cycles. Paired specimens were tested (one exposed to 60k loading cycles, one to static loading only), and comparisons of flexural modulus and strength showed statistically significantly higher values for cyclically-loaded specimens across materials, with no observable differences in fracture morphology. Localized reorganization of dentin collagen and polymer chains could have increased flexural modulus and strength during cyclic loading, which may have implications toward the life and failure mechanisms of clinical restorations and underlying tooth structure. PMID:18823019

  17. Nuclear accident dosimetry intercomparison studies

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

    Sims, C.S.

    1989-09-01

    Twenty-two nuclear accident dosimetry intercomparison studies utilizing the fast-pulse Health Physics Research Reactor at the Oak Ridge National Laboratory have been conducted since 1965. These studies have provided a total of 62 different organizations a forum for discussion of criticality accident dosimetry, an opportunity to test their neutron and gamma-ray dosimetry systems under a variety of simulated criticality accident conditions, and the experience of comparing results with reference dose values as well as with the measured results obtained by others making measurements under identical conditions. Sixty-nine nuclear accidents (27 with unmoderated neutron energy spectra and 42 with eight different shieldedmore » spectra) have been simulated in the studies. Neutron doses were in the 0.2-8.5 Gy range and gamma doses in the 0.1-2.0 Gy range. A total of 2,289 dose measurements (1,311 neutron, 978 gamma) were made during the intercomparisons. The primary methods of neutron dosimetry were activation foils, thermoluminescent dosimeters, and blood sodium activation. The main methods of gamma dose measurement were thermoluminescent dosimeters, radiophotoluminescent glass, and film. About 68% of the neutron measurements met the accuracy guidelines (+/- 25%) and about 52% of the gamma measurements met the accuracy criterion (+/- 20%) for accident dosimetry.« less

  18. Contact mechanics of modular metal-on-polyethylene total hip replacement under adverse edge loading conditions

    PubMed Central

    Hua, Xijin; Li, Junyan; Wang, Ling; Jin, Zhongmin; Wilcox, Ruth; Fisher, John

    2014-01-01

    Edge loading can negatively impact the biomechanics and long-term performance of hip replacements. Although edge loading has been widely investigated for hard-on-hard articulations, limited work has been conducted for hard-on-soft combinations. The aim of the present study was to investigate edge loading and its effect on the contact mechanics of a modular metal-on-polyethylene (MoP) total hip replacement (THR). A three-dimensional finite element model was developed based on a modular MoP bearing. Different cup inclination angles and head lateral microseparation were modelled and their effect on the contact mechanics of the modular MoP hip replacement were examined. The results showed that lateral microseparation caused loading of the head on the rim of the cup, which produced substantial increases in the maximum von Mises stress in the polyethylene liner and the maximum contact pressure on both the articulating surface and backside surface of the liner. Plastic deformation of the liner was observed under both standard conditions and microseparation conditions, however, the maximum equivalent plastic strain in the liner under microseparation conditions of 2000 µm was predicted to be approximately six times that under standard conditions. The study has indicated that correct positioning the components to avoid edge loading is likely to be important clinically even for hard-on-soft bearings for THR. PMID:25218504

  19. Effect of the load size on the efficiency of microwave heating under stop flow and continuous flow conditions.

    PubMed

    Patil, Narendra G; Rebrov, Evgeny V; Eränen, Kari; Benaskar, Faysal; Meuldijk, Jan; Mikkola, Jyri-Pekka; Hessel, Volker; Hulshof, Lumbertus A; Murzin, Dmitry Yu; Schouten, Jaap C

    2012-01-01

    A novel heating efficiency analysis of the microwave heated stop-flow (i.e. stagnant liquid) and continuous-flow reactors has been presented. The thermal losses to the surrounding air by natural convection have been taken into account for heating efficiency calculation of the microwave heating process. The effect of the load diameter in the range of 4-29 mm on the heating efficiency of ethylene glycol was studied in a single mode microwave cavity under continuous flow and stop-flow conditions. The variation of the microwave absorbing properties of the load with temperature was estimated. Under stop-flow conditions, the heating efficiency depends on the load diameter. The highest heating efficiency has been observed at the load diameter close to the half wavelength of the electromagnetic field in the corresponding medium. Under continuous-flow conditions, the heating efficiency increased linearly. However, microwave leakage above the propagation diameter restricted further experimentation at higher load diameters. Contrary to the stop-flow conditions, the load temperature did not raise monotonously from the inlet to outlet under continuous-flow conditions. This was due to the combined effect of lagging convective heat fluxes in comparison to volumetric heating. This severely disturbs the uniformity of the electromagnetic field in the axial direction and creates areas of high and low field intensity along the load Length decreasing the heating efficiency as compared to stop-flow conditions.

  20. Effect of Loading Rate and Surface Conditions on Flexural Strength of Borosilicate Glass

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

    Nie, X; Chen, Wayne; Wereszczak, Andrew A

    2009-01-01

    This study evaluates the loading rate and surface condition dependence of the flexural strength of a borosilicate glass. The glass specimens are subjected to three different surface treatments before four-point bending tests to study the effect of surface flaws. Quasistatic (Material Test System 810) and dynamic (Kolsky bar) experiments are performed at loading rates ranging from 0.7 to 4 x 10{sup 6} MPa/s. The results show that the flexural strength of the borosilicate glass has a strong dependence on the loading rate. A chemically etched surface produces an enhanced flexural strength by about an order of magnitude. Scanning electron microscopymore » images on fracture surfaces indicate that the failure is governed by different types of flaws under different surface treatment conditions. Edge failure is also identified for samples possessing high flexural strength.« less

  1. Behavior of U 3Si 2 Fuel and FeCrAl Cladding under Normal Operating and Accident Reactor Conditions

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

    Gamble, Kyle Allan Lawrence; Hales, Jason Dean; Barani, Tommaso

    2016-09-01

    As part of the Department of Energy's Nuclear Energy Advanced Modeling and Simulation program, an Accident Tolerant Fuel High Impact Problem was initiated at the beginning of fiscal year 2015 to investigate the behavior of \\usi~fuel and iron-chromium-aluminum (FeCrAl) claddings under normal operating and accident reactor conditions. The High Impact Problem was created in response to the United States Department of Energy's renewed interest in accident tolerant materials after the events that occurred at the Fukushima Daiichi Nuclear Power Plant in 2011. The High Impact Problem is a multinational laboratory and university collaborative research effort between Idaho National Laboratory, Losmore » Alamos National Laboratory, Argonne National Laboratory, and the University of Tennessee, Knoxville. This report primarily focuses on the engineering scale research in fiscal year 2016 with brief summaries of the lower length scale developments in the areas of density functional theory, cluster dynamics, rate theory, and phase field being presented.« less

  2. Fission product release from fuel under LWR accident conditions

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

    Osborne, M.F.; Lorenz, R.A.; Norwood, K.S.

    Three tests have provided additional data on fission product release under LWR accident conditions in a temperature range (1400 to 2000/sup 0/C). In the release rate data are compared with curves from a recent NRC-sponsored review of available fission product release data. Although the iodine release in test HI-3 was inexplicably low, the other data points for Kr, I, and Cs fall reasonably close to the corresponding curve, thereby tending to verify the NRC review. The limited data for antimony and silver release fall below the curves. Results of spark source mass spectrometric analyses were in agreement with the gammamore » spectrometric results. Nonradioactive fission products such as Rb and Br appeared to behave like their chemical analogs Cs and I. Results suggest that Te, Ag, Sn, and Sb are released from the fuel in elemental form. Analysis of the cesium and iodine profiles in the thermal gradient tube indicates that iodine was deposited as CsT along with some other less volatile cesium compound. The cesium profiles and chemical reactivity indicate the presence of more than one cesium species.« less

  3. 76 FR 44245 - Special Conditions: Gulfstream Model GVI Airplane; Limit Engine Torque Loads for Sudden Engine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-25

    ... Conditions No. 25-441-SC] Special Conditions: Gulfstream Model GVI Airplane; Limit Engine Torque Loads for... transient dynamic loads resulting from: (a) The loss of any fan, compressor, or turbine blade; and (b...;Federal Register / Vol. 76, No. 142 / Monday, July 25, 2011 / Rules and Regulations#0;#0; [[Page 44245...

  4. Aspects Concerning The Rules And The Investigation Of Traffic Accidents As Work Accidents

    NASA Astrophysics Data System (ADS)

    Tarnu, Lucian Ioan

    2015-07-01

    When Romania joined the European Union, it was imposed that the Romanian legislation in the field of the security and health at work be in line with the European one. The concept of health as it is defined by the International Body of Health, refers to a good physical, mental and social condition. The improvement of the activity of preventing the traffic accidents as work accidents must have as basis the correct and accurate evaluation of risks of getting injured. The goal of the activity of prevention and protection is to ensure the best working conditions, the prevention of accidents and occupational diseases and the adjustment to the scientific and technological progress. In the road transport sector, as in any other sector, it is very important to pay attention to working conditions to ensure a workforce motivated and well qualified. Some features make it a more difficult sector risk management than other sectors. However, if one takes into account how it works in practice this sector and the characteristics of drivers and how they work routinely, risks, dangers and threats can be managed efficiently and with great success.

  5. Influence of linear profile modification and loading conditions on the dynamic tooth load and stress of high contact ratio gears

    NASA Technical Reports Server (NTRS)

    Lee, Chinwai; Lin, Hsiang Hsi; Oswald, Fred B.; Townsend, Dennis P.

    1990-01-01

    A computer simulation for the dynamic response of high-contact-ratio spur gear transmissions is presented. High contact ratio gears have the potential to produce lower dynamic tooth loads and minimum root stress but they can be sensitive to tooth profile errors. The analysis presented examines various profile modifications under realistic loading conditions. The effect of these modifications on the dynamic load (force) between mating gear teeth and the dynamic root stress is presented. Since the contact stress is dependent on the dynamic load, minimizing dynamic loads will also minimize contact stresses. It is shown that the combination of profile modification and the applied load (torque) carried by a gear system has a significant influence on gear dynamics. The ideal modification at one value of applied load will not be the best solution for a different load. High-contact-ratio gears were found to require less modification than standard low-contact-ratio gears. High-contact-ratio gears are more adversely affected by excess modification than by under modification. In addition, the optimal profile modification required to minimize the dynamic load (hence the contact stress) on a gear tooth differs from the optimal modification required to minimize the dynamic root (bending) stress. Computer simulation can help find the design tradeoffs to determine the best profile modification to satisfy the conflicting constraints of minimizing both the load and root stress in gears which must operate over a range of applied loads.

  6. PWR-related integral safety experiments in the PKL 111 test facility SBLOCA under beyond-design-basis accident conditions

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

    Weber, P.; Umminger, K.J.; Schoen, B.

    1995-09-01

    The thermal hydraulic behavior of a PWR during beyond-design-basis accident scenarios is of vital interest for the verification and optimization of accident management procedures. Within the scope of the German reactor safety research program experiments were performed in the volumetrically scaled PKL 111 test facility by Siemens/KWU. This highly instrumented test rig simulates a KWU-design PWR (1300 MWe). In particular, the latest tests performed related to a SBLOCA with additional system failures, e.g. nitrogen entering the primary system. In the case of a SBLOCA, it is the goal of the operator to put the plant in a condition where themore » decay heat can be removed first using the low pressure emergency core cooling system and then the residual heat removal system. The experimental investigation presented assumed the following beyond-design-basis accident conditions: 0.5% break in a cold leg, 2 of 4 steam generators (SGs) isolated on the secondary side (feedwater- and steam line-valves closed), filled with steam on the primary side, cooldown of the primary system using the remaining two steam generators, high pressure injection system only in the two loops with intact steam generators, if possible no operator actions to reach the conditions for residual heat removal system activation. Furthermore, it was postulated that 2 of the 4 hot leg accumulators had a reduced initial water inventory (increased nitrogen inventory), allowing nitrogen to enter the primary system at a pressure of 15 bar and nearly preventing the heat transfer in the SGs ({open_quotes}passivating{close_quotes} U-tubes). Due to this the heat transfer regime in the intact steam generators changed remarkably. The primary system showed self-regulating system effects and heat transfer improved again (reflux-condenser mode in the U-tube inlet region).« less

  7. Behavior of road accidents: Structural time series approach

    NASA Astrophysics Data System (ADS)

    Junus, Noor Wahida Md; Ismail, Mohd Tahir; Arsad, Zainudin

    2014-12-01

    Road accidents become a major issue in contributing to the increasing number of deaths. Few researchers suggest that road accidents occur due to road structure and road condition. The road structure and condition may differ according to the area and volume of traffic of the location. Therefore, this paper attempts to look up the behavior of the road accidents in four main regions in Peninsular Malaysia by employing a structural time series (STS) approach. STS offers the possibility of modelling the unobserved component such as trends and seasonal component and it is allowed to vary over time. The results found that the number of road accidents is described by a different model. Perhaps, the results imply that the government, especially a policy maker should consider to implement a different approach in ways to overcome the increasing number of road accidents.

  8. Instrumentation Performance During the TMI-2 Accident

    NASA Astrophysics Data System (ADS)

    Rempe, Joy L.; Knudson, Darrell L.

    2014-08-01

    The accident at the Three Mile Island Unit 2 (TMI-2) reactor provided a unique opportunity to evaluate sensors exposed to severe accident conditions. The loss of coolant and the hydrogen combustion that occurred during this accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. As part of a program initiated by the Department of Energy Office of Nuclear Energy (DOE-NE), a review was completed to gain insights from prior TMI-2 sensor survivability and data qualification efforts. This new effort focused upon a set of sensors that provided critical data to TMI-2 operators for assessing the condition of the plant and the effects of mitigating actions taken by these operators. In addition, the effort considered sensors providing data required for subsequent accident simulations. Over 100 references related to instrumentation performance and post-accident evaluations of TMI-2 sensors and measurements were reviewed. Insights gained from this review are summarized within this paper. As noted within this paper, several techniques were invoked in the TMI-2 post-accident program to evaluate sensor survivability status and data qualification, including comparisons with data from other sensors, analytical calculations, laboratory testing, and comparisons with sensors subjected to similar conditions in large-scale integral tests and with sensors that were similar in design but more easily removed from the TMI-2 plant for evaluations. Conclusions from this review provide important insights related to sensor survivability and enhancement options for improving sensor performance. In addition, this paper provides recommendations related to sensor survivability and the data evaluation process that could be implemented in upcoming Fukushima Daiichi recovery efforts.

  9. Numerical Solution of Systems of Loaded Ordinary Differential Equations with Multipoint Conditions

    NASA Astrophysics Data System (ADS)

    Assanova, A. T.; Imanchiyev, A. E.; Kadirbayeva, Zh. M.

    2018-04-01

    A system of loaded ordinary differential equations with multipoint conditions is considered. The problem under study is reduced to an equivalent boundary value problem for a system of ordinary differential equations with parameters. A system of linear algebraic equations for the parameters is constructed using the matrices of the loaded terms and the multipoint condition. The conditions for the unique solvability and well-posedness of the original problem are established in terms of the matrix made up of the coefficients of the system of linear algebraic equations. The coefficients and the righthand side of the constructed system are determined by solving Cauchy problems for linear ordinary differential equations. The solutions of the system are found in terms of the values of the desired function at the initial points of subintervals. The parametrization method is numerically implemented using the fourth-order accurate Runge-Kutta method as applied to the Cauchy problems for ordinary differential equations. The performance of the constructed numerical algorithms is illustrated by examples.

  10. Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident

    NASA Astrophysics Data System (ADS)

    Su'ud, Zaki; Anshari, Rio

    2012-06-01

    Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environment such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.

  11. The flow field investigations of no load conditions in axial flow fixed-blade turbine

    NASA Astrophysics Data System (ADS)

    Yang, J.; Gao, L.; Wang, Z. W.; Zhou, X. Z.; Xu, H. X.

    2014-03-01

    During the start-up process, the strong instabilities happened at no load operation in a low head axial flow fixed-blade turbine, with strong pressure pulsation and vibration. The rated speed can not reach until guide vane opening to some extent, and stable operation could not be maintained under the rated speed at some head, which had a negative impact on the grid-connected operation of the unit. In order to find the reason of this phenomenon, the unsteady flow field of the whole flow passage at no load conditions was carried out to analyze the detailed fluid field characteristics including the pressure pulsation and force imposed on the runner under three typical heads. The main hydraulic cause of no load conditions instability was described. It is recommended that the power station should try to reduce the no-load running time and go into the high load operation as soon as possible when connected to grid at the rated head. Following the recommendations, the plant operation practice proved the unstable degree of the unit was reduced greatly during start up and connect to the power grid.

  12. Condition factor calibration for load and resistance factor rating of steel girder bridges : final report.

    DOT National Transportation Integrated Search

    2016-06-01

    Load and Resistance Factor Rating (LRFR) is a reliability-based rating procedure complementary to Load and Resistance Factor Design (LRFD). The intent of LRFR is to provide consistent reliability for all bridges regardless of in-situ condition. The p...

  13. A Study Of High Speed Friction Behavior Under Elastic Loading Conditions

    NASA Astrophysics Data System (ADS)

    Crawford, P. J.; Hammerberg, J. E.

    2005-03-01

    The role of interfacial dynamics under high strain-rate conditions is an important constitutive relationship in modern modeling and simulation studies of dynamic events (<100 μs in length). The frictional behavior occurring at the interface between two metal surfaces under high elastic loading and sliding speed conditions is studied using the Rotating Barrel Gas Gun (RBGG) facility. The RBGG utilizes a low-pressure gas gun to propel a rotating annular projectile towards an annular target rod. Upon striking the target, the projectile imparts both an axial and a torsional impulse into the target. Resulting elastic waves are measured using strain gauges attached to the target rod. The kinetic coefficient of friction is obtained through an analysis of the resulting strain wave data. Experiments performed using Cu/Cu, Cu/Stainless steel and Cu/Al interfaces provide some insight into the kinetic coefficient of friction behavior at varying sliding speeds and impact loads.

  14. Lumbopelvic muscle activation patterns in three stances under graded loading conditions: Proposing a tensegrity model for load transfer through the sacroiliac joints.

    PubMed

    Pardehshenas, Hamed; Maroufi, Nader; Sanjari, Mohammad Ali; Parnianpour, Mohamad; Levin, Stephen M

    2014-10-01

    According to the conventional arch model of the pelvis, stability of the sacroiliac joints may require a predominance of form and force closure mechanisms: the greater the vertical shear force at the sacroiliac joints, the greater the reliance on self-bracing by horizontally or obliquely oriented muscles (such as the internal oblique). But what happens to the arch model when a person stands on one leg? In such cases, the pelvis no longer has imposts, leaving both the arch, and the arch model theory, without support. Do lumbopelvic muscle activation patterns in one-legged stances under load suggest compatibility with a different model? This study compares lumbopelvic muscle activation patterns in two-legged and one-legged stances in response to four levels of graded trunk loading in order to further our understanding the stabilization of the sacroiliac joints. Thirty male subjects experienced four levels of trunk loading (0%, 5%, 10% and 15% of body weight) by holding a bucket at one side, at three conditions: 1) two-legged standing with the bucket in the dominant hand, 2) ipsilateral loading: one-legged standing with the bucket in the dominant hand while using the same-side leg, and 3) contralateral loading: one-legged standing using the same leg used in condition 2, but with the bucket in the non-dominant hand. During these tasks, EMG signals from eight lumbopelvic muscles were collected. ANOVA with repeated design was performed on normalized EMG's to test the main effect of load and condition, and interaction effects of load by condition. Latissimus dorsi and erector spinae muscles showed an antagonistic pattern of activity toward the direction of load which may suggest these muscles as lateral trunk stabilizers. Internal oblique muscles showed a co-activation pattern with increasing task demand, which may function to increase lumbopelvic stability (P < 0.05). No unilateral pattern of the internal obliques was observed during all trials. Our results suggest that

  15. Response and representation of ductile damage under varying shock loading conditions in tantalum

    DOE PAGES

    Bronkhorst, C. A.; Gray, III, G. T.; Addessio, F. L.; ...

    2016-02-25

    The response of polycrystalline metals, which possess adequate mechanisms for plastic deformation under extreme loading conditions, is often accompanied by the formation of pores within the structure of the material. This large deformation process is broadly identified as progressive with nucleation, growth, coalescence, and failure the physical path taken over very short periods of time. These are well known to be complex processes strongly influenced by microstructure, loading path, and the loading profile, which remains a significant challenge to represent and predict numerically. In the current study, the influence of loading path on the damage evolution in high-purity tantalum ismore » presented. Tantalum samples were shock loaded to three different peak shock stresses using both symmetric impact, and two different composite flyer plate configurations such that upon unloading the three samples displayed nearly identical “pull-back” signals as measured via rear-surface velocimetry. While the “pull-back” signals observed were found to be similar in magnitude, the sample loaded to the highest peak stress nucleated a connected field of ductile fracture which resulted in complete separation, while the two lower peak stresses resulted in incipient damage. The damage evolution in the “soft” recovered tantalum samples was quantified using optical metallography, electron-back-scatter diffraction, and tomography. These experiments are examined numerically through the use of a model for shock-induced porosity evolution during damage. The model is shown to describe the response of the tantalum reasonably well under strongly loaded conditions but less well in the nucleation dominated regime. As a result, numerical results are also presented as a function of computational mesh density and discussed in the context of improved representation of the influence of material structure upon macro-scale models of ductile damage.« less

  16. A surface crack in shells under mixed-mode loading conditions

    NASA Technical Reports Server (NTRS)

    Joseph, P. F.; Erdogan, F.

    1988-01-01

    The present consideration of a shallow shell's surface crack under general loading conditions notes that while the mode I state can be separated, modes II and III remain coupled. A line spring model is developed to formulate the part-through crack problem under mixed-mode conditions, and then to consider a shallow shell of arbitrary curvature having a part-through crack located on the outer or the inner surface of the shell; Reissner's transverse shear theory is used to formulate the problem under the assumption that the shell is subjected to all five moment and stress resultants.

  17. Fracture loads of all-ceramic crowns under wet and dry fatigue conditions.

    PubMed

    Borges, Gilberto A; Caldas, Danilo; Taskonak, Burak; Yan, Jiahau; Sobrinho, Lourenco Correr; de Oliveira, Wildomar José

    2009-12-01

    The aim of this study was to test the hypothesis that fracture loads of fatigued dental ceramic crowns are affected by testing environment and luting cement. One hundred and eighty crowns were prepared from bovine teeth using a lathe. Ceramic crowns were prepared from three types of ceramic systems: an alumina-infiltrated ceramic, a lithia-disilicate-based glass ceramic, and a leucite-reinforced ceramic. For each ceramic system, 30 crowns were cemented with a composite resin cement, and the remaining 30 with a resin-modified glass ionomer cement. For each ceramic system and cement, ten specimens were loaded to fracture without fatiguing. A second group (n = 10) was subjected to cyclic fatigue and fracture tested in a dry environment, and a third group (n = 10) was fatigued and fractured in distilled water. The results were statistically analyzed using one-way ANOVA and Tukey HSD test. The fracture loads of ceramic crowns decreased significantly after cyclic fatigue loading (ploads of crowns fatigued in a wet environment were statistically lower than those in a dry environment (p < 0.05). Crowns luted with a composite resin cement showed statistically greater fracture loads than those luted with a resin-modified glass ionomer cement (pload of the three ceramic systems was found to be influenced by ceramic composition. Moreover, cement and fatigue condition influenced the fracture loads of the crown specimens evaluated in this study.

  18. 49 CFR 195.52 - Immediate notice of certain accidents.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Immediate notice of certain accidents. 195.52... TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Annual, Accident, and Safety-Related Condition Reporting § 195.52 Immediate notice of certain accidents. (a) Notice requirements. At the earliest practicable moment following...

  19. Joint angles of the ankle, knee, and hip and loading conditions during split squats.

    PubMed

    Schütz, Pascal; List, Renate; Zemp, Roland; Schellenberg, Florian; Taylor, William R; Lorenzetti, Silvio

    2014-06-01

    The aim of this study was to quantify how step length and the front tibia angle influence joint angles and loading conditions during the split squat exercise. Eleven subjects performed split squats with an additional load of 25% body weight applied using a barbell. Each subject's movements were recorded using a motion capture system, and the ground reaction force was measured under each foot. The joint angles and loading conditions were calculated using a cluster-based kinematic approach and inverse dynamics modeling respectively. Increases in the tibia angle resulted in a smaller range of motion (ROM) of the front knee and a larger ROM of the rear knee and hip. The external flexion moment in the front knee/hip and the external extension moment in the rear hip decreased as the tibia angle increased. The flexion moment in the rear knee increased as the tibia angle increased. The load distribution between the legs changed < 25% when split squat execution was varied. Our results describing the changes in joint angles and the resulting differences in the moments of the knee and hip will allow coaches and therapists to adapt the split squat exercise to the individual motion and load demands of athletes.

  20. 49 CFR 195.52 - Telephonic notice of certain accidents.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Telephonic notice of certain accidents. 195.52... TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Annual, Accident, and Safety-Related Condition Reporting § 195.52 Telephonic notice of certain accidents. (a) At the earliest practicable moment following discovery of a...

  1. Meaning of missing values in eyewitness recall and accident records.

    PubMed

    Uttl, Bob; Kisinger, Kelly

    2010-09-02

    Eyewitness recalls and accident records frequently do not mention the conditions and behaviors of interest to researchers and lead to missing values and to uncertainty about the prevalence of these conditions and behaviors surrounding accidents. Missing values may occur because eyewitnesses report the presence but not the absence of obvious clues/accident features. We examined this possibility. Participants watched car accident videos and were asked to recall as much information as they could remember about each accident. The results showed that eyewitnesses were far more likely to report the presence of present obvious clues than the absence of absent obvious clues even though they were aware of their absence. One of the principal mechanisms causing missing values may be eyewitnesses' tendency to not report the absence of obvious features. We discuss the implications of our findings for both retrospective and prospective analyses of accident records, and illustrate the consequences of adopting inappropriate assumptions about the meaning of missing values using the Avaluator Avalanche Accident Prevention Card.

  2. Severe Accident Test Station Design Document

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

    Snead, Mary A.; Yan, Yong; Howell, Michael

    The purpose of the ORNL severe accident test station (SATS) is to provide a platform for evaluation of advanced fuels under projected beyond design basis accident (BDBA) conditions. The SATS delivers the capability to map the behavior of advanced fuels concepts under accident scenarios across various temperature and pressure profiles, steam and steam-hydrogen gas mixtures, and thermal shock. The overall facility will include parallel capabilities for examination of fuels and irradiated materials (in-cell) and non-irradiated materials (out-of-cell) at BDBA conditions as well as design basis accident (DBA) or loss of coolant accident (LOCA) conditions. Also, a supporting analytical infrastructure tomore » provide the data-needs for the fuel-modeling components of the Fuel Cycle Research and Development (FCRD) program will be put in place in a parallel manner. This design report contains the information for the first, second and third phases of design and construction of the SATS. The first phase consisted of the design and construction of an out-of-cell BDBA module intended for examination of non-irradiated materials. The second phase of this work was to construct the BDBA in-cell module to test irradiated fuels and materials as well as the module for DBA (i.e. LOCA) testing out-of-cell, The third phase was to build the in-cell DBA module. The details of the design constraints and requirements for the in-cell facility have been closely captured during the deployment of the out-of-cell SATS modules to ensure effective future implementation of the in-cell modules.« less

  3. Structural Impact of Construction Loads : [Technical Summary

    DOT National Transportation Integrated Search

    2012-01-01

    Numerous bridge construction accidents have occurred : because of construction loadings, which are an underemphasized : topic in many specifications and design : manuals. Bridge girders are least stable during the : construction phase, so it is impor...

  4. Probabilistic dose assessment of normal operations and accident conditions for an assured isolation facility in Texas

    NASA Astrophysics Data System (ADS)

    Arno, Matthew Gordon

    Texas is investigating building a long-term waste storage facility, also known as an Assured Isolation Facility. This is an above-ground low-level radioactive waste storage facility that is actively maintained and from which waste may be retrieved. A preliminary, scoping-level analysis has been extended to consider more complex scenarios of radiation streaming and skyshine by using the computer code Monte Carlo N-Particle (MCNP) to model the facility in greater detail. Accidental release scenarios have been studied in more depth to better assess the potential dose to off-site individuals. Using bounding source term assumptions, the projected radiation doses and dose rates are estimated to exceed applicable limits by an order of magnitude. By altering the facility design to fill in the hollow cores of the prefabricated concrete slabs used in the roof over the "high-gamma rooms," where the waste with the highest concentration of gamma emitting radioactive material is stored, dose rates outside the facility decrease by an order of magnitude. With the modified design, the annual dose at the site fenceline is estimated at 86 mrem, below the 100 mrem annual limit for exposure of the public. Within the site perimeter, the dose rates are lowered sufficiently such that it is not necessary to categorize many workers and contractor personnel as radiation workers, saving on costs as well as being advisable under ALARA principles. A detailed analysis of bounding accidents incorporating information on the local meteorological conditions indicate that the maximum committed effective dose equivalent from the passage of a plume of material released in an accident at any of the cities near the facility is 59 :rem in the city of Eunice, NM based on the combined day and night meteorological conditions. Using the daytime meteorological conditions, the maximum dose at any city is 7 :rem, also in the city of Eunice. The maximum dose at the site boundary was determined to be 230 mrem

  5. Mechanical Characterization of the Human Lumbar Intervertebral Disc Subjected to Impact Loading Conditions

    NASA Astrophysics Data System (ADS)

    Jamison, David, IV

    Low back pain is a large and costly problem in the United States. Several working populations, such as miners, construction workers, forklift operators, and military personnel, have an increased risk and prevalence of low back pain compared to the general population. This is due to exposure to repeated, transient impact shocks, particularly while operating vehicles or other machinery. These shocks typically do not cause acute injury, but rather lead to pain and injury over time. The major focus in low back pain is often the intervertebral disc, due to its role as the major primary load-bearing component along the spinal column. The formation of a reliable standard for human lumbar disc exposure to repeated transient shock could potentially reduce injury risk for these working populations. The objective of this project, therefore, is to characterize the mechanical response of the lumbar intervertebral disc subjected to sub-traumatic impact loading conditions using both cadaveric and computational models, and to investigate the possible implications of this type of loading environment for low back pain. Axial, compressive impact loading events on Naval high speed boats were simulated in the laboratory and applied to human cadaveric specimen. Disc stiffness was higher and hysteresis was lower than quasi-static loading conditions. This indicates a shift in mechanical response when the disc is under impact loads and this behavior could be contributing to long-term back pain. Interstitial fluid loss and disc height changes were shown to affect disc impact mechanics in a creep study. Neutral zone increased, while energy dissipation and low-strain region stiffness decreased. This suggests that the disc has greater clinical instability during impact loading with progressive creep and fluid loss, indicating that time of day should be considered for working populations subjected to impact loads. A finite element model was developed and validated against cadaver specimen

  6. Numerical reconstruction and injury biomechanism in a car-pedestrian crash accident.

    PubMed

    Zou, Dong-Hua; Li, Zheng-Dong; Shao, Yu; Feng, Hao; Chen, Jian-Guo; Liu, Ning-Guo; Huang, Ping; Chen, Yi-Jiu

    2012-12-01

    To reconstruct a car-pedestrian crash accident using numerical simulation technology and explore the injury biomechanism as forensic evidence for injury identification. An integration of multi-body dynamic, finite element (FE), and classical method was applied to a car-pedestrian crash accident. The location of the collision and the details of the traffic accident were determined by vehicle trace verification and autopsy. The accident reconstruction was performed by coupling the three-dimensional car behavior from PC-CRASH with a MADYMO dummy model. The collision FE models of head and leg, developed from CT scans of human remains, were loaded with calculated dummy collision parameters. The data of the impact biomechanical responses were extracted in terms of von Mises stress, relative displacement, strain and stress fringes. The accident reconstruction results were identical with the examined ones and the biomechanism of head and leg injuries, illustrated through the FE methods, were consistent with the classical injury theories. The numerical simulation technology is proved to be effective in identifying traffic accidents and exploring of injury biomechanism.

  7. Structural Impact of Construction Loads : [Technical Summary

    DOT National Transportation Integrated Search

    2012-01-01

    Numerous bridge construction accidents have occurred because of construction loadings, which are an underemphasized topic in many specifications and design manuals. Bridge girders are least stable during the construction phase, so it is important for...

  8. Development of the rules governing the strength of airplanes. Part II : loading conditions in Germany (continued), England and the United States

    NASA Technical Reports Server (NTRS)

    Kussner, H G; Thalau, Karl

    1933-01-01

    Load factors and loading conditions are presented for Germany, England, and the United States. Results of tests are presented and loading conditions are presented under various stress categories like freight, commercial, aerobatics, and training.

  9. Modeling when and where a secondary accident occurs.

    PubMed

    Wang, Junhua; Liu, Boya; Fu, Ting; Liu, Shuo; Stipancic, Joshua

    2018-01-31

    The occurrence of secondary accidents leads to traffic congestion and road safety issues. Secondary accident prevention has become a major consideration in traffic incident management. This paper investigates the location and time of a potential secondary accident after the occurrence of an initial traffic accident. With accident data and traffic loop data collected over three years from California interstate freeways, a shock wave-based method was introduced to identify secondary accidents. A linear regression model and two machine learning algorithms, including a back-propagation neural network (BPNN) and a least squares support vector machine (LSSVM), were implemented to explore the distance and time gap between the initial and secondary accidents using inputs of crash severity, violation category, weather condition, tow away, road surface condition, lighting, parties involved, traffic volume, duration, and shock wave speed generated by the primary accident. From the results, the linear regression model was inadequate in describing the effect of most variables and its goodness-of-fit and accuracy in prediction was relatively poor. In the training programs, the BPNN and LSSVM demonstrated adequate goodness-of-fit, though the BPNN was superior with a higher CORR and lower MSE. The BPNN model also outperformed the LSSVM in time prediction, while both failed to provide adequate distance prediction. Therefore, the BPNN model could be used to forecast the time gap between initial and secondary accidents, which could be used by decision makers and incident management agencies to prevent or reduce secondary collisions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Preliminary analysis of loss-of-coolant accident in Fukushima nuclear accident

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

    Su'ud, Zaki; Anshari, Rio

    Loss-of-Coolant Accident (LOCA) in Boiling Water Reactor (BWR) especially on Fukushima Nuclear Accident will be discussed in this paper. The Tohoku earthquake triggered the shutdown of nuclear power reactors at Fukushima Nuclear Power station. Though shutdown process has been completely performed, cooling process, at much smaller level than in normal operation, is needed to remove decay heat from the reactor core until the reactor reach cold-shutdown condition. If LOCA happen at this condition, it will cause the increase of reactor fuel and other core temperatures and can lead to reactor core meltdown and exposure of radioactive material to the environmentmore » such as in the Fukushima Dai Ichi nuclear accident case. In this study numerical simulation has been performed to calculate pressure composition, water level and temperature distribution on reactor during this accident. There are two coolant regulating system that operational on reactor unit 1 at this accident, Isolation Condensers (IC) system and Safety Relief Valves (SRV) system. Average mass flow of steam to the IC system in this event is 10 kg/s and could keep reactor core from uncovered about 3,2 hours and fully uncovered in 4,7 hours later. There are two coolant regulating system at operational on reactor unit 2, Reactor Core Isolation Condenser (RCIC) System and Safety Relief Valves (SRV). Average mass flow of coolant that correspond this event is 20 kg/s and could keep reactor core from uncovered about 73 hours and fully uncovered in 75 hours later. There are three coolant regulating system at operational on reactor unit 3, Reactor Core Isolation Condenser (RCIC) system, High Pressure Coolant Injection (HPCI) system and Safety Relief Valves (SRV). Average mass flow of water that correspond this event is 15 kg/s and could keep reactor core from uncovered about 37 hours and fully uncovered in 40 hours later.« less

  11. Feasibility study of superconducting power cables for DC electric railway feeding systems in view of thermal condition at short circuit accident

    NASA Astrophysics Data System (ADS)

    Kumagai, Daisuke; Ohsaki, Hiroyuki; Tomita, Masaru

    2016-12-01

    A superconducting power cable has merits of a high power transmission capacity, transmission losses reduction, a compactness, etc., therefore, we have been studying the feasibility of applying superconducting power cables to DC electric railway feeding systems. However, a superconducting power cable is required to be cooled down and kept at a very low temperature, so it is important to reveal its thermal and cooling characteristics. In this study, electric circuit analysis models of the system and thermal analysis models of superconducting cables were constructed and the system behaviors were simulated. We analyzed the heat generation by a short circuit accident and transient temperature distribution of the cable to estimate the value of temperature rise and the time required from the accident. From these results, we discussed a feasibility of superconducting cables for DC electric railway feeding systems. The results showed that the short circuit accident had little impact on the thermal condition of a superconducting cable in the installed system.

  12. Edge crack sensitivity of lightweight materials under different load conditions

    NASA Astrophysics Data System (ADS)

    Tsoupis, I.; Merklein, M.

    2016-11-01

    This study addresses the analysis of edge crack sensitivity of DP800 steel and AA5182 aluminum alloy in dependency of punching and machining operation as well as load case of subsequent forming. The inserting of a round hole by punching with defined punch-to- die-clearance, milling and drilling is compared. Subsequent forming is performed by standardized hole expansion test and by Nakajima-tests with three different specimen geometries. Local strain distribution at the surface for Nakajima-tests is measured by optical strain measurement technique and investigated in order to evaluate local deformation before failure. Additionally, resulting hole expansion ratio λ is determined. Significant higher X as well as local strain values ε max are achieved by machined holes. This is directly coupled to higher local formability and stretchability for both materials. Furthermore, the load condition has a strong impact on the edge crack sensitivity of the material. Prior failure is observed with changing stress conditions using different specimen geometries also influencing the reachable maximum failure strain. Higher edge crack sensitivity is observed for DP800, which is in good accordance to the material properties in terms of ductility and strength. These data in dependency of the process parameter can be used for the design of automotive components.

  13. Meaning of Missing Values in Eyewitness Recall and Accident Records

    PubMed Central

    Uttl, Bob; Kisinger, Kelly

    2010-01-01

    Background Eyewitness recalls and accident records frequently do not mention the conditions and behaviors of interest to researchers and lead to missing values and to uncertainty about the prevalence of these conditions and behaviors surrounding accidents. Missing values may occur because eyewitnesses report the presence but not the absence of obvious clues/accident features. We examined this possibility. Methodology/Principal Findings Participants watched car accident videos and were asked to recall as much information as they could remember about each accident. The results showed that eyewitnesses were far more likely to report the presence of present obvious clues than the absence of absent obvious clues even though they were aware of their absence. Conclusions One of the principal mechanisms causing missing values may be eyewitnesses' tendency to not report the absence of obvious features. We discuss the implications of our findings for both retrospective and prospective analyses of accident records, and illustrate the consequences of adopting inappropriate assumptions about the meaning of missing values using the Avaluator Avalanche Accident Prevention Card. PMID:20824054

  14. Benchmarking MARS (accident management software) with the Browns Ferry fire

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

    Dawson, S.M.; Liu, L.Y.; Raines, J.C.

    1992-01-01

    The MAAP Accident Response System (MARS) is a userfriendly computer software developed to provide management and engineering staff with the most needed insights, during actual or simulated accidents, of the current and future conditions of the plant based on current plant data and its trends. To demonstrate the reliability of the MARS code in simulatng a plant transient, MARS is being benchmarked with the available reactor pressure vessel (RPV) pressure and level data from the Browns Ferry fire. The MRS software uses the Modular Accident Analysis Program (MAAP) code as its basis to calculate plant response under accident conditions. MARSmore » uses a limited set of plant data to initialize and track the accidnt progression. To perform this benchmark, a simulated set of plant data was constructed based on actual report data containing the information necessary to initialize MARS and keep track of plant system status throughout the accident progression. The initial Browns Ferry fire data were produced by performing a MAAP run to simulate the accident. The remaining accident simulation used actual plant data.« less

  15. Comparative analysis of different loading conditions on large container ships from the perspective of the stability requirement

    NASA Astrophysics Data System (ADS)

    Stanca, C.; Acomi, N.; Ancuta, C.; Georgescu, S.

    2015-11-01

    Container ships carry cargoes that are considered light from the weight point of view, compared to their volumetric capacity. This fact makes the still water vertical bending moment to be in hogging condition. Thus, the double bottom structure is permanent subject to compressive load. With the enlargement of container ships to the Post Panamax vessels, the breadth to depth ratio tends to be increased comparative to those of Panamax container ships that present restriction related to maximum breadth of the ship.The current studies on new build models reveal the impossibility for Panamax container ships to comply with the minimum metacentric height value of stability without loading ballast water in the double bottom tanks. In contrast, the Post-Panamax container ships, as resulted from metacentric height calculation, have adequate stability even if the ballast water is not loaded in the double bottom tanks. This analysis was conducted considering two partially loaded port-container vessels. Given the minimization of ballast quantities, the frequency with which the still water vertical bending moment reaches close to the allowable value increases.This study aims to analyse the ships’ behaviour in partially loaded conditions and carrying ballast water in the double bottom tanks. By calculating the metacentric height that influences the stability of the partially loaded port container vessels, this study will emphasize the critical level of loading condition which triggers the uptake of ballast water in the double bottom tanks, due to metacentric height variation.

  16. Orbiter Payload Bay Bucket Hoist Mishap...An Accident We Should Never Forget

    NASA Technical Reports Server (NTRS)

    Lytle, Bradford P.

    2009-01-01

    This slide presentation reviews the accident that occurred in 1985 when a bay bucket hoist fell from its stowed position. This accident damaged the orbiter, injured a technician, and delayed the launch. The accident was investigated, and the cause of the accident was determined to be the practice of two-blocking. Two-blocking is the result of hoisting beyond the intended safe upper limit of hook travel to the point of solid contact between the load block and the upper block or hoist/trolley structure. The usual result is immediate failure of the wire rope, due to the ropes being cut by the grooves of the drum or sheaves. The design of the hoist, the inspection, and the operator training were all in part responsible for this failure.

  17. BNL severe-accident sequence experiments and analysis program. [PWR; BWR

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

    Greene, G.A.; Ginsberg, T.; Tutu, N.K.

    1983-01-01

    In the analysis of degraded core accidents, the two major sources of pressure loading on light water reactor containments are: steam generation from core debris-water thermal interactions; and molten core-concrete interactions. Experiments are in progress at BNL in support of analytical model development related to aspects of the above containment loading mechanisms. The work supports development and evaluation of the CORCON (Muir, 1981) and MARCH (Wooton, 1980) computer codes. Progress in the two programs is described.

  18. Dynamic strain aging in stress controlled creep-fatigue tests of 316L stainless steel under different loading conditions

    NASA Astrophysics Data System (ADS)

    Jiang, Huifeng; Chen, Xuedong; Fan, Zhichao; Dong, Jie; Jiang, Heng; Lu, Shouxiang

    2009-08-01

    Stress controlled fatigue-creep tests were carried out for 316L stainless steel under different loading conditions, i.e. different loading levels at the fixed temperature (loading condition 1, LC1) and different temperatures at the fixed loading level (loading condition 2, LC2). Cyclic deformation behaviors were investigated with respect to the evolutions of strain amplitude and mean strain. Abrupt mean strain jumps were found during cyclic deformation, which was in response to the dynamic strain aging effect. Moreover, as to LC1, when the minimum stress is negative at 550 °C, abrupt mean strain jumps occur at the early stage of cyclic deformation and there are many jumps during the whole process. While the minimum stress is positive, mean strain only jumps once at the end of deformation. Similar results were also found in LC2, when the loading level is fixed at -100 to 385 MPa, at higher temperatures (560, 575 °C), abrupt mean strain jumps occur at the early stage of cyclic deformation and there are many jumps during the whole process. While at lower temperature (540 °C), mean strain only jumps once at the end of deformation.

  19. MELCOR simulations of the severe accident at Fukushima Daiichi Unit 3

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

    Cardoni, Jeffrey; Gauntt, Randall; Kalinich, Donald

    In response to the accident at the Fukushima Daiichi nuclear power station in Japan, the U.S. Nuclear Regulatory Commission and U.S. Department of Energy agreed to jointly sponsor an accident reconstruction study as a means of assessing the severe accident modeling capability of the MELCOR code. Objectives of the project included reconstruction of the accident progressions using computer models and accident data, and validation of the MELCOR code and the Fukushima models against plant data. A MELCOR 2.1 model of the Fukushima Daiichi Unit 3 reactor is developed using plant-specific information and accident-specific boundary conditions, which involve considerable uncertainty duemore » to the inherent nature of severe accidents. Publicly available thermal-hydraulic data and radioactivity release estimates have evolved significantly since the accidents. Such data are expected to continually change as the reactors are decommissioned and more measurements are performed. As a result, the MELCOR simulations in this work primarily use boundary conditions that are based on available plant data as of May 2012.« less

  20. MELCOR simulations of the severe accident at Fukushima Daiichi Unit 3

    DOE PAGES

    Cardoni, Jeffrey; Gauntt, Randall; Kalinich, Donald; ...

    2014-05-01

    In response to the accident at the Fukushima Daiichi nuclear power station in Japan, the U.S. Nuclear Regulatory Commission and U.S. Department of Energy agreed to jointly sponsor an accident reconstruction study as a means of assessing the severe accident modeling capability of the MELCOR code. Objectives of the project included reconstruction of the accident progressions using computer models and accident data, and validation of the MELCOR code and the Fukushima models against plant data. A MELCOR 2.1 model of the Fukushima Daiichi Unit 3 reactor is developed using plant-specific information and accident-specific boundary conditions, which involve considerable uncertainty duemore » to the inherent nature of severe accidents. Publicly available thermal-hydraulic data and radioactivity release estimates have evolved significantly since the accidents. Such data are expected to continually change as the reactors are decommissioned and more measurements are performed. As a result, the MELCOR simulations in this work primarily use boundary conditions that are based on available plant data as of May 2012.« less

  1. Factors contributing to young moped rider accidents in Denmark.

    PubMed

    Møller, Mette; Haustein, Sonja

    2016-02-01

    Young road users still constitute a high-risk group with regard to road traffic accidents. The crash rate of a moped is four times greater than that of a motorcycle, and the likelihood of being injured in a road traffic accident is 10-20 times higher among moped riders compared to car drivers. Nevertheless, research on the behaviour and accident involvement of young moped riders remains sparse. Based on analysis of 128 accident protocols, the purpose of this study was to increase knowledge about moped accidents. The study was performed in Denmark involving riders aged 16 or 17. A distinction was made between accident factors related to (1) the road and its surroundings, (2) the vehicle, and (3) the reported behaviour and condition of the road user. Thirteen accident factors were identified with the majority concerning the reported behaviour and condition of the road user. The average number of accident factors assigned per accident was 2.7. Riding speed was assigned in 45% of the accidents which made it the most frequently assigned factor on the part of the moped rider followed by attention errors (42%), a tuned up moped (29%) and position on the road (14%). For the other parties involved, attention error (52%) was the most frequently assigned accident factor. The majority (78%) of the accidents involved road rule breaching on the part of the moped rider. The results indicate that preventive measures should aim to eliminate violations and increase anticipatory skills among moped riders and awareness of mopeds among other road users. Due to their young age the effect of such measures could be enhanced by infrastructural measures facilitating safe interaction between mopeds and other road users. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Design and Implementation of a Fuzzy Accident Detector

    NASA Astrophysics Data System (ADS)

    Jafari, Shahram; Arabnejad, Mohammad; Rashidi Moakhar, Ali

    A fuzzy accident detector has been proposed in this paper. The implemented controller ensures a reliable margin for the speed of a car. This is done by carefully observing the skills of the driver in controlling the automobile during a critical condition. Since x- and y- accelerations of the automobile change sharply during an accident, such conditions can be detected. The system also updates the speed limits in different locations on the road.

  3. Traffic dynamics around weaving section influenced by accident: Cellular automata approach

    NASA Astrophysics Data System (ADS)

    Kong, Lin-Peng; Li, Xin-Gang; Lam, William H. K.

    2015-07-01

    The weaving section, as a typical bottleneck, is one source of vehicle conflicts and an accident-prone area. Traffic accident will block lanes and the road capacity will be reduced. Several models have been established to study the dynamics around traffic bottlenecks. However, little attention has been paid to study the complex traffic dynamics influenced by the combined effects of bottleneck and accident. This paper presents a cellular automaton model to characterize accident-induced traffic behavior around the weaving section. Some effective control measures are proposed and verified for traffic management under accident condition. The total flux as a function of inflow rates, the phase diagrams, the spatial-temporal diagrams, and the density and velocity profiles are presented to analyze the impact of accident. It was shown that the proposed control measures for weaving traffic can improve the capacity of weaving section under both normal and accident conditions; the accidents occurring on median lane in the weaving section are more inclined to cause traffic jam and reduce road capacity; the capacity of weaving section will be greatly reduced when the accident happens downstream the weaving section.

  4. Numerical simulations of the occupant head response in an infantry vehicle under blunt impact and blast loading conditions.

    PubMed

    Sevagan, Gopinath; Zhu, Feng; Jiang, Binhui; Yang, King H

    2013-07-01

    This article presents the results of a finite element simulation on the occupant head response in an infantry vehicle under two separated loading conditions: (1) blunt impact and (2) blast loading conditions. A Hybrid-III dummy body integrated with a previously validated human head model was used as the surrogate. The biomechanical response of the head was studied in terms of head acceleration due to the impact by a projectile on the vehicle and intracranial pressure caused by blast wave. A series of parametric studies were conducted on the numerical model to analyze the effect of some key parameters, such as seat configuration, impact velocity, and boundary conditions. The simulation results indicate that a properly designed seat and internal surface of the infantry vehicle can play a vital role in reducing the risk of head injury in the current scenarios. Comparison of the kinematic responses under the blunt impact and blast loading conditions reveals that under the current loading conditions, the acceleration pulse in the blast scenario has much higher peak values and frequency than blunt impact case, which may reflect different head response characteristics.

  5. Pilot Domain Task Experience in Night Fatal Helicopter Emergency Medical Service Accidents.

    PubMed

    Aherne, Bryan B; Zhang, Chrystal; Newman, David G

    2016-06-01

    In the United States, accident and fatality rates in helicopter emergency medical service (HEMS) operations increase significantly under nighttime environmentally hazardous operational conditions. Other studies have found pilots' total flight hours unrelated to HEMS accident outcomes. Many factors affect pilots' decision making, including their experience. This study seeks to investigate whether pilot domain task experience (DTE) in HEMS plays a role against likelihood of accidents at night when hazardous operational conditions are entered. There were 32 flights with single pilot nighttime fatal HEMS accidents between 1995 and 2013 with findings of controlled flight into terrain (CFIT) and loss of control (LCTRL) due to spatial disorientation (SD) identified. The HEMS DTE of the pilots were compared with industry survey data. Of the pilots, 56% had ≤2 yr of HEMS experience and 9% had >10 yr of HEMS experience. There were 21 (66%) accidents that occurred in non-visual flight rules (VFR) conditions despite all flights being required to be conducted under VFR. There was a statistically significant increase in accident rates in pilots with <2 and <4 yr HEMS DTE and a statistically significant decrease in accident rates in pilots with >10 yr HEMS DTE. HEMS DTE plays a preventive role against the likelihood of a night operational accident. Pilots with limited HEMS DTE are more likely to make a poor assessment of hazardous conditions at night, and this will place HEMS flight crew at high risk in the VFR night domain.

  6. Body Condition Peaks at Intermediate Parasite Loads in the Common Bully Gobiomorphus cotidianus

    PubMed Central

    Maceda-Veiga, Alberto; Green, Andy J.; Poulin, Robert; Lagrue, Clément

    2016-01-01

    Most ecologists and conservationists perceive parasitic infections as deleterious for the hosts. Their effects, however, depend on many factors including host body condition, parasite load and the life cycle of the parasite. More research into how multiple parasite taxa affect host body condition is required and will help us to better understand host-parasite coevolution. We used body condition indices, based on mass-length relationships, to test the effects that abundances and biomasses of six parasite taxa (five trematodes, Apatemon sp., Tylodelphys sp., Stegodexamene anguillae, Telogaster opisthorchis, Coitocaecum parvum, and the nematode Eustrongylides sp.) with different modes of transmission have on the body condition of their intermediate or final fish host, the common bully Gobiomorphus cotidianus in New Zealand. We used two alternative body condition methods, the Scaled Mass Index (SMI) and Fulton’s condition factor. General linear and hierarchical partitioning models consistently showed that fish body condition varied strongly across three lakes and seasons, and that most parasites did not have an effect on the two body condition indices. However, fish body condition showed a highly significant humpbacked relationship with the total abundance of all six parasite taxa, mostly driven by Apatemon sp. and S. anguillae, indicating that the effects of these parasites can range from positive to negative as abundance increases. Such a response was also evident in models including total parasite biomass. Our methodological comparison supports the SMI as the most robust mass-length method to examine the effects of parasitic infections on fish body condition, and suggests that linear, negative relationships between host condition and parasite load should not be assumed. PMID:28030606

  7. Aging and loading rate effects on the mechanical behavior of equine bone

    NASA Astrophysics Data System (ADS)

    Kulin, Robb M.; Jiang, Fengchun; Vecchio, Kenneth S.

    2008-06-01

    Whether due to a sporting accident, high-speed impact, fall, or other catastrophic event, the majority of clinical bone fractures occur under dynamic loading conditions. However, although extensive research has been performed on the quasi-static fracture and mechanical behavior of bone to date, few high-quality studies on the fracture behavior of bone at high strain rates have been performed. Therefore, many questions remain regarding the material behavior, including not only the loading-rate-dependent response of bone, but also how this response varies with age. In this study, tests were performed on equine femoral bone taken post-mortem from donors 6 months to 28 years of age. Quasi-static and dynamic tests were performed to determine the fracture toughness and compressive mechanical behavior as a function of age at varying loading rates. Fracture paths were then analyzed using scanning confocal and scanning-electron microscopy techniques to assess the role of various microstructural features on toughening mechanisms.

  8. Hard-on-hard lubrication in the artificial hip under dynamic loading conditions.

    PubMed

    Sonntag, Robert; Reinders, Jörn; Rieger, Johannes S; Heitzmann, Daniel W W; Kretzer, J Philippe

    2013-01-01

    The tribological performance of an artificial hip joint has a particularly strong influence on its success. The principle causes for failure are adverse short- and long-term reactions to wear debris and high frictional torque in the case of poor lubrication that may cause loosening of the implant. Therefore, using experimental and theoretical approaches models have been developed to evaluate lubrication under standardized conditions. A steady-state numerical model has been extended with dynamic experimental data for hard-on-hard bearings used in total hip replacements to verify the tribological relevance of the ISO 14242-1 gait cycle in comparison to experimental data from the Orthoload database and instrumented gait analysis for three additional loading conditions: normal walking, climbing stairs and descending stairs. Ceramic-on-ceramic bearing partners show superior lubrication potential compared to hard-on-hard bearings that work with at least one articulating metal component. Lubrication regimes during the investigated activities are shown to strongly depend on the kinematics and loading conditions. The outcome from the ISO gait is not fully confirmed by the normal walking data and more challenging conditions show evidence of inferior lubrication. These findings may help to explain the differences between the in vitro predictions using the ISO gait cycle and the clinical outcome of some hard-on-hard bearings, e.g., using metal-on-metal.

  9. Hard-on-Hard Lubrication in the Artificial Hip under Dynamic Loading Conditions

    PubMed Central

    Sonntag, Robert; Reinders, Jörn; Rieger, Johannes S.; Heitzmann, Daniel W. W.; Kretzer, J. Philippe

    2013-01-01

    The tribological performance of an artificial hip joint has a particularly strong influence on its success. The principle causes for failure are adverse short- and long-term reactions to wear debris and high frictional torque in the case of poor lubrication that may cause loosening of the implant. Therefore, using experimental and theoretical approaches models have been developed to evaluate lubrication under standardized conditions. A steady-state numerical model has been extended with dynamic experimental data for hard-on-hard bearings used in total hip replacements to verify the tribological relevance of the ISO 14242-1 gait cycle in comparison to experimental data from the Orthoload database and instrumented gait analysis for three additional loading conditions: normal walking, climbing stairs and descending stairs. Ceramic-on-ceramic bearing partners show superior lubrication potential compared to hard-on-hard bearings that work with at least one articulating metal component. Lubrication regimes during the investigated activities are shown to strongly depend on the kinematics and loading conditions. The outcome from the ISO gait is not fully confirmed by the normal walking data and more challenging conditions show evidence of inferior lubrication. These findings may help to explain the differences between the in vitro predictions using the ISO gait cycle and the clinical outcome of some hard-on-hard bearings, e.g., using metal-on-metal. PMID:23940772

  10. Fatigue Life Estimation under Cumulative Cyclic Loading Conditions

    NASA Technical Reports Server (NTRS)

    Kalluri, Sreeramesh; McGaw, Michael A; Halford, Gary R.

    1999-01-01

    The cumulative fatigue behavior of a cobalt-base superalloy, Haynes 188 was investigated at 760 C in air. Initially strain-controlled tests were conducted on solid cylindrical gauge section specimens of Haynes 188 under fully-reversed, tensile and compressive mean strain-controlled fatigue tests. Fatigue data from these tests were used to establish the baseline fatigue behavior of the alloy with 1) a total strain range type fatigue life relation and 2) the Smith-Wastson-Topper (SWT) parameter. Subsequently, two load-level multi-block fatigue tests were conducted on similar specimens of Haynes 188 at the same temperature. Fatigue lives of the multi-block tests were estimated with 1) the Linear Damage Rule (LDR) and 2) the nonlinear Damage Curve Approach (DCA) both with and without the consideration of mean stresses generated during the cumulative fatigue tests. Fatigue life predictions by the nonlinear DCA were much closer to the experimentally observed lives than those obtained by the LDR. In the presence of mean stresses, the SWT parameter estimated the fatigue lives more accurately under tensile conditions than under compressive conditions.

  11. [Manual handling of loads in the hotel trade: the experience of the ASL (Local Health Unit) Milan].

    PubMed

    Fontani, S; Mercuri, Irene; Salicco, R; Veratti, Silvia; Sorrentino, L

    2010-01-01

    There are over 400 hotels in Milan with a guest capacity of about 62,000 and employing more than 10,000 workers. In 2008/09 the Occupational Health and Safety Service of A.S.L. Milano (Local Health Unit) carried out research into the hotel trade to ascertain the development of this commercial sector, also in view of EXPO 2015. The aim of the project was to improve hygiene and safety conditions and carry out preventive measures. A specific purpose was to study manual handling of loads and repetitive movements risk. The study covered 30 hotels and 7 temporary staff cooperatives. We acquired the Risk Evaluation Document, the Health Surveillance Programme and Registers of Labour Accidents to analyze manual handling of loads and repetitive movements. In the investigations and assessments on hotels we used currently available scientific tools--NIOSH Lifting Index, Push and Pulling Analysis, OC.R.A. Check-List--to study risks related to handling loads and upper limb mechanical overload, which revealed a specific occupational risk that requires a fresh approach to prevention and safety in the entire sector. Chambermaid: LI (Range): 0.57-2.75; Push and Pulling Actions: Fi 0.66-Fm 1.5 and Fi 0.76-Fm 1.33 respectively; OC.R.A. Check-List: 21. Porter: LI (Range): 0.77-3.75. Maintenance staff LI (Range): 0.57-2.75. The study highlighted the presence of risk due to manual handling of loads and repetitive movements in porters, maintenance personnel and particularly in chambermaids that up to now have been poorly assessed by safety experts. Analysis of the information contained in the registers of labour accidents suggests that a significant number of accidents can be related to muscular-skeletal disorders that affect especially cleaning, portering and kitchen staff

  12. Development of Database for Accident Analysis in Indian Mines

    NASA Astrophysics Data System (ADS)

    Tripathy, Debi Prasad; Guru Raghavendra Reddy, K.

    2016-10-01

    Mining is a hazardous industry and high accident rates associated with underground mining is a cause of deep concern. Technological developments notwithstanding, rate of fatal accidents and reportable incidents have not shown corresponding levels of decline. This paper argues that adoption of appropriate safety standards by both mine management and the government may result in appreciable reduction in accident frequency. This can be achieved by using the technology in improving the working conditions, sensitising workers and managers about causes and prevention of accidents. Inputs required for a detailed analysis of an accident include information on location, time, type, cost of accident, victim, nature of injury, personal and environmental factors etc. Such information can be generated from data available in the standard coded accident report form. This paper presents a web based application for accident analysis in Indian mines during 2001-2013. An accident database (SafeStat) prototype based on Intranet of the TCP/IP agreement, as developed by the authors, is also discussed.

  13. Comparison of Thoracic Injury Risk in Frontal Car Crashes for Occupant Restrained without Belt Load Limiters and Those Restrained with 6 kN and 4 kN Belt Load Limiters.

    PubMed

    Foret-Bruno, J Y; Trosseille, X; Page, Y; Huère, J F; Le Coz, J Y; Bendjellal, F; Diboine, A; Phalempin, T; Villeforceix, D; Baudrit, P; Guillemot, H; Coltat, J C

    2001-11-01

    In France, as in other countries, accident research studies show that a large proportion of restrained occupants who sustain severe or fatal injuries are involved in frontal impacts (65% and 50%, respectively). In severe frontal impacts with restrained occupants and where intrusion is not preponderant, the oldest occupants very often sustain severe thoracic injuries due to the conventional seat belt. As we have been observing over the last years, we will expect in the coming years developments which include more solidly-built cars, as offset crash test procedures are widely used to evaluate the passive safety of production vehicles. The reduction of intrusion for the most severe frontal impacts, through optimization of car deformation, usually translates into an increase in restraint forces and hence thoracic injury risk with a conventional retractor seat belt for a given impact severity. It is, therefore essential to limit the restraint forces exerted by the seat belt on the thorax in order to reduce the number of road casualties. In order to address thoracic injury risk in frontal impact, Renault cars have been equipped with the Programmed Restraint System (PRS) since 1995. The PRS is a restraint system that combines belt load limitation and pyrotechnic belt pretension. In an initial design of the Programmed Restraint System (PRS1), the belt load limiter was a steel component designed to shear at a given shoulder force, namely 6 kN. It was mounted between the retractor and the lower anchorage point of the belt. The design of the PRS was modified in 1998 (PRS2), but the principle of load limitation was maintained. The threshold was decreased to 4 kN and this lower belt belt-force limiter has been combined with a specially designed airbag. This paper reports on 347 real-world frontal accidents where the EES (Equivalent Energy Speed) ranged from 35 to 75 km/h. One hundred and ninety-eight (198) of these accidents involved cars equipped with the 6 kN load limiter

  14. Characterizing the Collagen Fiber Orientation in Pericardial Leaflets Under Mechanical Loading Conditions

    PubMed Central

    Alavi, S. Hamed; Ruiz, Victor; Krasieva, Tatiana; Botvinick, Elliot L.; Kheradvar, Arash

    2014-01-01

    When implanted inside the body, bioprosthetic heart valve leaflets experience a variety of cyclic mechanical stresses such as shear stress due to blood flow when the valve is open, flexural stress due to cyclic opening and closure of the valve, and tensile stress when the valve is closed. These types of stress lead to a variety of failure modes. In either a natural valve leaflet or a processed pericardial tissue leaflet, collagen fibers reinforce the tissue and provide structural integrity such that the very thin leaflet can stand enormous loads related to cyclic pressure changes. The mechanical response of the leaflet tissue greatly depends on collagen fiber concentration, characteristics, and orientation. Thus, understating the microstructure of pericardial tissue and its response to dynamic loading is crucial for the development of more durable heart valve, and computational models to predict heart valves’ behavior. In this work, we have characterized the 3D collagen fiber arrangement of bovine pericardial tissue leaflets in response to a variety of different loading conditions under Second-Harmonic Generation Microscopy. This real-time visualization method assists in better understanding of the effect of cyclic load on collagen fiber orientation in time and space. PMID:23180029

  15. [Drugs and occupational accident].

    PubMed

    Bratzke, H; Albers, C

    1996-02-01

    In a case of a fatal occupational accident (construction worker, fall from roof, urine test positive for cocaine and THC, e.g. cannabis) the question arised to what extent those drug-related occupational accidents occur. In the literature only few cases, mainly dealing with cannabis influence, have been reported, however, a higher number is suspected. Cocaine and other stimulating drugs (amphetamine) are more often used to increase physical fitness. By direct or indirect interference with vigilance these compounds may provoke accidents. Due to the lack of a legal basis proving of the influence of drugs at the working place is still very limited, although highly sensitive chemical-toxicological assay procedures are available to detect even the chronic abuse (in hair). In the general conditions of accident insurances a compensation is excluded when alcohol is involved, but drugs are not mentioned. It is indeed difficult to establish a concentration limit for drugs like that existing for alcohol (1.1%). In each case the assay of the drug involved and exact knowledge of its specific effects is in an essential prerequisite to prove the causal relationship.

  16. Causes and risk factors for fatal accidents in non-commercial twin engine piston general aviation aircraft.

    PubMed

    Boyd, Douglas D

    2015-04-01

    Accidents in twin-engine aircraft carry a higher risk of fatality compared with single engine aircraft and constitute 9% of all general aviation accidents. The different flight profile (higher airspeed, service ceiling, increased fuel load, and aircraft yaw in engine failure) may make comparable studies on single-engine aircraft accident causes less relevant. The objective of this study was to identify the accident causes for non-commercial operations in twin engine aircraft. A NTSB accident database query for accidents in twin piston engine airplanes of 4-8 seat capacity with a maximum certified weight of 3000-8000lbs. operating under 14CFR Part 91 for the period spanning 2002 and 2012 returned 376 accidents. Accident causes and contributing factors were as per the NTSB final report categories. Total annual flight hour data for the twin engine piston aircraft fleet were obtained from the FAA. Statistical analyses employed Chi Square, Fisher's Exact and logistic regression analysis. Neither the combined fatal/non-fatal accident nor the fatal accident rate declined over the period spanning 2002-2012. Under visual weather conditions, the largest number, n=27, (27%) of fatal accidents was attributed to malfunction with a failure to follow single engine procedures representing the most common contributing factor. In degraded visibility, poor instrument approach procedures resulted in the greatest proportion of fatal crashes. Encountering thunderstorms was the most lethal of all accident causes with all occupants sustaining fatal injuries. At night, a failure to maintain obstacle/terrain clearance was the most common accident cause leading to 36% of fatal crashes. The results of logistic regression showed that operations at night (OR 3.7), off airport landings (OR 14.8) and post-impact fire (OR 7.2) all carried an excess risk of a fatal flight. This study indicates training areas that should receive increased emphasis for twin-engine training/recency. First, increased

  17. Polyurethane foam loaded with sodium dodecylsulfate for the extraction of 'quat' pesticides from aqueous medium: Optimization of loading conditions.

    PubMed

    Vinhal, Jonas O; Lima, Claudio F; Cassella, Ricardo J

    2016-09-01

    The cationic herbicides paraquat, diquat and difenzoquat are largely used in different cultures worldwide. With this, there is an intrinsic risk of environmental contamination when these herbicides achieve natural waters. The goal of this work was to propose a novel and low-cost sorbent for the removal of the cited herbicides from aqueous medium. The proposed sorbent was prepared by loading polyurethane foam with sodium dodecylsulfate. The influence of several parameters (SDS concentration, HCl concentration and shaking time) on the loading process was investigated. The results obtained in this work demonstrated that all studied variables influenced the loading process, having significant effect on the extraction efficiency of the resulted PUF-SDS. At optimized conditions, the PUF was loaded by shaking 200mg of crushed foam with 200mL of a solution containing 5.0×10(-3)molL(-1) SDS and 0.25molL(-1) HCl, for 30min. The obtained PUF-SDS was efficient for removing the three herbicides from aqueous medium, achieving extraction percentages higher than 90%. The sorption process followed a pseudo second-order kinetics, which presented excellent predictive capacity of the amount of herbicide retained with time. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Analysis on Reactor Criticality Condition and Fuel Conversion Capability Based on Different Loaded Plutonium Composition in FBR Core

    NASA Astrophysics Data System (ADS)

    Permana, Sidik; Saputra, Geby; Suzuki, Mitsutoshi; Saito, Masaki

    2017-01-01

    Reactor criticality condition and fuel conversion capability are depending on the fuel arrangement schemes, reactor core geometry and fuel burnup process as well as the effect of different fuel cycle and fuel composition. Criticality condition of reactor core and breeding ratio capability have been investigated in this present study based on fast breeder reactor (FBR) type for different loaded fuel compositions of plutonium in the fuel core regions. Loaded fuel of Plutonium compositions are based on spent nuclear fuel (SNF) of light water reactor (LWR) for different fuel burnup process and cooling time conditions of the reactors. Obtained results show that different initial fuels of plutonium gives a significant chance in criticality conditions and fuel conversion capability. Loaded plutonium based on higher burnup process gives a reduction value of criticality condition or less excess reactivity. It also obtains more fuel breeding ratio capability or more breeding gain. Some loaded plutonium based on longer cooling time of LWR gives less excess reactivity and in the same time, it gives higher breeding ratio capability of the reactors. More composition of even mass plutonium isotopes gives more absorption neutron which affects to decresing criticality or less excess reactivity in the core. Similar condition that more absorption neutron by fertile material or even mass plutonium will produce more fissile material or odd mass plutonium isotopes to increase the breeding gain of the reactor.

  19. Tobit analysis of vehicle accident rates on interstate highways.

    PubMed

    Anastasopoulos, Panagiotis Ch; Tarko, Andrew P; Mannering, Fred L

    2008-03-01

    There has been an abundance of research that has used Poisson models and its variants (negative binomial and zero-inflated models) to improve our understanding of the factors that affect accident frequencies on roadway segments. This study explores the application of an alternate method, tobit regression, by viewing vehicle accident rates directly (instead of frequencies) as a continuous variable that is left-censored at zero. Using data from vehicle accidents on Indiana interstates, the estimation results show that many factors relating to pavement condition, roadway geometrics and traffic characteristics significantly affect vehicle accident rates.

  20. Analyzing the severity of accidents on the German Autobahn.

    PubMed

    Manner, Hans; Wünsch-Ziegler, Laura

    2013-08-01

    We study the severity of accidents on the German Autobahn in the state of North Rhine-Westphalia using data for the years 2009 until 2011. We use a multinomial logit model to identify statistically relevant factors explaining the severity of the most severe injury, which is classified into the four classes fatal, severe injury, light injury and property damage. Furthermore, to account for unobserved heterogeneity we use a random parameter model. We study the effect of a number of factors including traffic information, road conditions, type of accidents, speed limits, presence of intelligent traffic control systems, age and gender of the driver and location of the accident. Our findings are in line with studies in different settings and indicate that accidents during daylight and at interchanges or construction sites are less severe in general. Accidents caused by the collision with roadside objects, involving pedestrians and motorcycles, or caused by bad sight conditions tend to be more severe. We discuss the measures of the 2011 German traffic safety programm in the light of our results. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Applications of AnnAGNPS model for soil loss estimation and nutrient loading for Malaysian conditions

    NASA Astrophysics Data System (ADS)

    Shamshad, A.; Leow, C. S.; Ramlah, A.; Wan Hussin, W. M. A.; Sanusi, S. A. Mohd.

    2008-09-01

    The study evaluated the performance and suitability of AnnAGNPS model in assessing runoff, sediment loading and nutrient loading under Malaysian conditions. The watershed of River Kuala Tasik in Malaysia, a combination of two sub-watersheds, was selected as the area of study. The data for the year 2004 was used to calibrate the model and the data for the year 2005 was used for validation purposes. Several input parameters were computed using methods suggested by other researchers and studies carried out in Malaysia. The study shows that runoff was predicted well with an overall R2 value of 0.90 and E value of 0.70. Sediment loading was able to produce a moderate result of R2 = 0.66 and E = 0.49, nitrogen loading predictions were slightly better with R2 = 0.68 and E = 0.53, and phosphorus loading performance was slightly poor with an R2 = 0.63 and E = 0.33. The erosion map developed was in agreement with the erosion risk map produced by the Department of Agriculture, Malaysia. Rubber estates and urban areas were found to be the main contributors to soil erosion. The simulation results showed that AnnAGNPS has the potential to be used as a valuable tool for planning and management of watersheds under Malaysian conditions.

  2. Sex-based differences in lifting technique under increasing load conditions: A principal component analysis.

    PubMed

    Sheppard, P S; Stevenson, J M; Graham, R B

    2016-05-01

    The objective of the present study was to determine if there is a sex-based difference in lifting technique across increasing-load conditions. Eleven male and 14 female participants (n = 25) with no previous history of low back disorder participated in the study. Participants completed freestyle, symmetric lifts of a box with handles from the floor to a table positioned at 50% of their height for five trials under three load conditions (10%, 20%, and 30% of their individual maximum isometric back strength). Joint kinematic data for the ankle, knee, hip, and lumbar and thoracic spine were collected using a two-camera Optotrak motion capture system. Joint angles were calculated using a three-dimensional Euler rotation sequence. Principal component analysis (PCA) and single component reconstruction were applied to assess differences in lifting technique across the entire waveforms. Thirty-two PCs were retained from the five joints and three axes in accordance with the 90% trace criterion. Repeated-measures ANOVA with a mixed design revealed no significant effect of sex for any of the PCs. This is contrary to previous research that used discrete points on the lifting curve to analyze sex-based differences, but agrees with more recent research using more complex analysis techniques. There was a significant effect of load on lifting technique for five PCs of the lower limb (PC1 of ankle flexion, knee flexion, and knee adduction, as well as PC2 and PC3 of hip flexion) (p < 0.005). However, there was no significant effect of load on the thoracic and lumbar spine. It was concluded that when load is standardized to individual back strength characteristics, males and females adopted a similar lifting technique. In addition, as load increased male and female participants changed their lifting technique in a similar manner. Copyright © 2016. Published by Elsevier Ltd.

  3. Design and implementation of an air-conditioning system with storage tank for load shifting

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

    Hsu, Y.Y.; Wu, C.J.; Liou, K.L.

    1987-11-01

    The experience with the design, simulation and implementation of an air-conditioning system with chilled water storage tank is presented in this paper. The system is used to shift air-conditioning load of residential and commercial buildings from on-peak to off-peak period. Demand-side load management can thus be achieved if many buildings are equipped with such storage devices. In the design of this system, a lumped-parameter circuit model is first employed to simulate the heat transfer within the air-conditioned building such that the required capacity of the storage tank can be figured out. Then, a set of desirable parameters for the temperaturemore » controller of the system are determined using the parameter plane method and the root locus method. The validity of the proposed mathematical model and design approach is verified by comparing the results obtained from field tests with those from the computer simulations. Cost-benefit analysis of the system is also discussed.« less

  4. Global ship accidents and ocean swell-related sea states

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiwei; Li, Xiao-Ming

    2017-11-01

    With the increased frequency of shipping activities, navigation safety has become a major concern, especially when economic losses, human casualties and environmental issues are considered. As a contributing factor, the sea state plays a significant role in shipping safety. However, the types of dangerous sea states that trigger serious shipping accidents are not well understood. To address this issue, we analyzed the sea state characteristics during ship accidents that occurred in poor weather or heavy seas based on a 10-year ship accident dataset. Sea state parameters of a numerical wave model, i.e., significant wave height, mean wave period and mean wave direction, were analyzed for the selected ship accident cases. The results indicated that complex sea states with the co-occurrence of wind sea and swell conditions represent threats to sailing vessels, especially when these conditions include similar wave periods and oblique wave directions.

  5. Effects of age and loading rate on equine cortical bone failure.

    PubMed

    Kulin, Robb M; Jiang, Fengchun; Vecchio, Kenneth S

    2011-01-01

    Although clinical bone fractures occur predominantly under impact loading (as occurs during sporting accidents, falls, high-speed impacts or other catastrophic events), experimentally validated studies on the dynamic fracture behavior of bone, at the loading rates associated with such events, remain limited. In this study, a series of tests were performed on femoral specimens obtained post-mortem from equine donors ranging in age from 6 months to 28 years. Fracture toughness and compressive tests were performed under both quasi-static and dynamic loading conditions in order to determine the effects of loading rate and age on the mechanical behavior of the cortical bone. Fracture toughness experiments were performed using a four-point bending geometry on single and double-notch specimens in order to measure fracture toughness, as well as observe differences in crack initiation between dynamic and quasi-static experiments. Compressive properties were measured on bone loaded parallel and transverse to the osteonal growth direction. Fracture propagation was then analyzed using scanning electron and scanning confocal microscopy to observe the effects of microstructural toughening mechanisms at different strain rates. Specimens from each horse were also analyzed for dry, wet and mineral densities, as well as weight percent mineral, in order to investigate possible influences of composition on mechanical behavior. Results indicate that bone has a higher compressive strength, but lower fracture toughness when tested dynamically as compared to quasi-static experiments. Fracture toughness also tends to decrease with age when measured quasi-statically, but shows little change with age under dynamic loading conditions, where brittle "cleavage-like" fracture behavior dominates. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Generation IV benchmarking of TRISO fuel performance models under accident conditions: Modeling input data

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

    Collin, Blaise P.

    2014-09-01

    This document presents the benchmark plan for the calculation of particle fuel performance on safety testing experiments that are representative of operational accidental transients. The benchmark is dedicated to the modeling of fission product release under accident conditions by fuel performance codes from around the world, and the subsequent comparison to post-irradiation experiment (PIE) data from the modeled heating tests. The accident condition benchmark is divided into three parts: the modeling of a simplified benchmark problem to assess potential numerical calculation issues at low fission product release; the modeling of the AGR-1 and HFR-EU1bis safety testing experiments; and, the comparisonmore » of the AGR-1 and HFR-EU1bis modeling results with PIE data. The simplified benchmark case, thereafter named NCC (Numerical Calculation Case), is derived from ''Case 5'' of the International Atomic Energy Agency (IAEA) Coordinated Research Program (CRP) on coated particle fuel technology [IAEA 2012]. It is included so participants can evaluate their codes at low fission product release. ''Case 5'' of the IAEA CRP-6 showed large code-to-code discrepancies in the release of fission products, which were attributed to ''effects of the numerical calculation method rather than the physical model''[IAEA 2012]. The NCC is therefore intended to check if these numerical effects subsist. The first two steps imply the involvement of the benchmark participants with a modeling effort following the guidelines and recommendations provided by this document. The third step involves the collection of the modeling results by Idaho National Laboratory (INL) and the comparison of these results with the available PIE data. The objective of this document is to provide all necessary input data to model the benchmark cases, and to give some methodology guidelines and recommendations in order to make all results suitable for comparison with each other. The participants should read this

  7. [HIV and the nursing professional in the face of needlestick accidents].

    PubMed

    Vieira, Mariana; Padilha, Maria Itayra Coelho de Souza

    2008-12-01

    The goal of this study was to identify the scientific production about work-related needlestick accidents among nursing professionals involving HIV-contaminated biological material, as well as to characterize the pre-existing factors to such accidents, such as procedures occurring after the exposure to potentially HIV-contaminated needlestick material. This is a literature review, whose bibliographic search for keywords was carried out within the LILACS databases from the year 2000 onward. This study confirms that pre-existing factors for the occurrence of work-related needlestick accidents are related to work conditions as much as to individual conditions. In face of these accidents, the nursing workers need to know the conducts concerning post-exposure to potentially HIV-contaminated needlestick material. We conclude that the adoption of standardized precautions when working in healthcare is a fundamental condition for worker safety, independently of their area of expertise, given the increasing number of HIV cases.

  8. Condition Assessment and End-of-Life Prediction System for Electric Machines and Their Loads

    NASA Technical Reports Server (NTRS)

    Parlos, Alexander G.; Toliyat, Hamid A.

    2005-01-01

    An end-of-life prediction system developed for electric machines and their loads could be used in integrated vehicle health monitoring at NASA and in other government agencies. This system will provide on-line, real-time condition assessment and end-of-life prediction of electric machines (e.g., motors, generators) and/or their loads of mechanically coupled machinery (e.g., pumps, fans, compressors, turbines, conveyor belts, magnetic levitation trains, and others). In long-duration space flight, the ability to predict the lifetime of machinery could spell the difference between mission success or failure. Therefore, the system described here may be of inestimable value to the U.S. space program. The system will provide continuous monitoring for on-line condition assessment and end-of-life prediction as opposed to the current off-line diagnoses.

  9. Ultra-high temperature tensile properties of ODS steel claddings under severe accident conditions

    NASA Astrophysics Data System (ADS)

    Yano, Y.; Tanno, T.; Oka, H.; Ohtsuka, S.; Inoue, T.; Kato, S.; Furukawa, T.; Uwaba, T.; Kaito, T.; Ukai, S.; Oono, N.; Kimura, A.; Hayashi, S.; Torimaru, T.

    2017-04-01

    Ultra-high temperature ring tensile tests were performed to investigate the tensile behavior of oxide dispersion strengthened (ODS) steel claddings and wrapper materials under severe accident conditions with temperatures ranging from room temperature to 1400 °C which is close to the melting point of core materials. The experimental results showed that the tensile strength of 9Cr-ODS steel claddings was highest in the core materials at ultra-high temperatures of 900-1200 °C, but there was significant degradation in the tensile strength of 9Cr-ODS steel claddings above 1200 °C. This degradation was attributed to grain boundary sliding deformation with γ/δ transformation, which is associated with reduced ductility. By contrast, the tensile strength of recrystallized 12Cr-ODS and FeCrAl-ODS steel claddings retained its high value above 1200 °C, unlike the other tested materials.

  10. Response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions

    USGS Publications Warehouse

    Rojstaczer, Stuart; Riley, Francis S.

    1990-01-01

    The response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions can be explained if the water level is controlled by the aquifer response averaged over the saturated depth of the well. Because vertical averaging tends to diminish the influence of the water table, the response is qualitatively similar to the response of a well under partially confined conditions. When the influence of well bore storage can be ignored, the response to Earth tides is strongly governed by a dimensionless aquifer frequency Q′u. The response to atmospheric loading is strongly governed by two dimensionless vertical fluid flow parameters: a dimensionless unsaturated zone frequency, R, and a dimensionless aquifer frequency Qu. The differences between Q′u and Qu are generally small for aquifers which are highly sensitive to Earth tides. When Q′u and Qu are large, the response of the well to Earth tides and atmospheric loading approaches the static response of the aquifer under confined conditions. At small values of Q′u and Qu, well response to Earth tides and atmospheric loading is strongly influenced by water table drainage. When R is large relative to Qu, the response to atmospheric loading is strongly influenced by attenuation and phase shift of the pneumatic pressure signal in the unsaturated zone. The presence of partial penetration retards phase advance in well response to Earth tides and atmospheric loading. When the theoretical response of a phreatic well to Earth tides and atmospheric loading is fit to the well response inferred from cross-spectral estimation, it is possible to obtain estimates of the pneumatic diffusivity of the unsaturated zone and the vertical hydraulic conductivity of the aquifer.

  11. Response of the Water Level in a Well to Earth Tides and Atmospheric Loading Under Unconfined Conditions

    NASA Astrophysics Data System (ADS)

    Rojstaczer, Stuart; Riley, Francis S.

    1990-08-01

    The response of the water level in a well to Earth tides and atmospheric loading under unconfined conditions can be explained if the water level is controlled by the aquifer response averaged over the saturated depth of the well. Because vertical averaging tends to diminish the influence of the water table, the response is qualitatively similar to the response of a well under partially confined conditions. When the influence of well bore storage can be ignored, the response to Earth tides is strongly governed by a dimensionless aquifer frequency Q'u. The response to atmospheric loading is strongly governed by two dimensionless vertical fluid flow parameters: a dimensionless unsaturated zone frequency, R, and a dimensionless aquifer frequency Qu. The differences between Q'u and Qu are generally small for aquifers which are highly sensitive to Earth tides. When Q'u and Qu are large, the response of the well to Earth tides and atmospheric loading approaches the static response of the aquifer under confined conditions. At small values of Q'u and Qu, well response to Earth tides and atmospheric loading is strongly influenced by water table drainage. When R is large relative to Qu, the response to atmospheric loading is strongly influenced by attenuation and phase shift of the pneumatic pressure signal in the unsaturated zone. The presence of partial penetration retards phase advance in well response to Earth tides and atmospheric loading. When the theoretical response of a phreatic well to Earth tides and atmospheric loading is fit to the well response inferred from cross-spectral estimation, it is possible to obtain estimates of the pneumatic diffusivity of the unsaturated zone and the vertical hydraulic conductivity of the aquifer.

  12. 78 FR 31851 - Harmonization of Airworthiness Standards-Gust and Maneuver Load Requirements

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-28

    ... airplanes equipped with wing-mounted engines; revise the engine torque loads criteria; add an engine failure... equipped with wing-mounted engines. Following an accident in which an airplane shed a large wing- mounted...-93-137, November 15, 1993). This recommendation was specifically aimed at gust loads on wing-mounted...

  13. Load Dependency of Postural Control--Kinematic and Neuromuscular Changes in Response to over and under Load Conditions.

    PubMed

    Ritzmann, Ramona; Freyler, Kathrin; Weltin, Elmar; Krause, Anne; Gollhofer, Albert

    2015-01-01

    Load variation is associated with changes in joint torque and compensatory reflex activation and thus, has a considerable impact on balance control. Previous studies dealing with over (OL) and under loading (UL) used water buoyancy or additional weight with the side effects of increased friction and inertia, resulting in substantially modified test paradigms. The purpose of this study was to identify gravity-induced load dependency of postural control in comparable experimental conditions and to determine the underlying neuromuscular mechanisms. Balance performance was recorded under normal loading (NL, 1 g), UL (0.16 g 0.38 g) and OL (1.8 g) in monopedal stance. Center of pressure (COP) displacement and frequency distribution (low 0.15-0.5 Hz (LF), medium 0.5-2 Hz (MF), high 2-6 Hz (HF)) as well as ankle, knee and hip joint kinematics were assessed. Soleus spinal excitability was determined by H/M-recruitment curves (H/M-ratios). Compared to NL, OL caused an increase in ankle joint excursion, COP HF domain and H/M-ratio. Concomitantly, hip joint excursion and COP LF decreased. Compared to NL, UL caused modulations in the opposite direction: UL decreased ankle joint excursions, COP HF and H/M-ratio. Collaterally, hip joint excursion and COP LF increased. COP was augmented both in UL and in OL compared to NL. Subjects achieved postural stability in OL and UL with greater difficulty compared to NL. Reduced postural control was accompanied by modified balance strategies and compensatory reflex activation. With increasing load, a shift from hip to ankle strategy was observed. Accompanying, COP frequency distribution shifted from LF to HF and spinal excitability was enhanced. It is suggested that in OL, augmented ankle joint torques are compensated by quick reflex-induced postural reactions in distal muscles. Contrarily, UL is associated with diminished joint torques and thus, postural equilibrium may be controlled by the proximal segments to adjust the center of

  14. Load Dependency of Postural Control - Kinematic and Neuromuscular Changes in Response to over and under Load Conditions

    PubMed Central

    Ritzmann, Ramona; Freyler, Kathrin; Weltin, Elmar; Krause, Anne; Gollhofer, Albert

    2015-01-01

    Introduction Load variation is associated with changes in joint torque and compensatory reflex activation and thus, has a considerable impact on balance control. Previous studies dealing with over (OL) and under loading (UL) used water buoyancy or additional weight with the side effects of increased friction and inertia, resulting in substantially modified test paradigms. The purpose of this study was to identify gravity-induced load dependency of postural control in comparable experimental conditions and to determine the underlying neuromuscular mechanisms. Methods Balance performance was recorded under normal loading (NL, 1g), UL (0.16g; 0.38g) and OL (1.8g) in monopedal stance. Center of pressure (COP) displacement and frequency distribution (low 0.15-0.5Hz (LF), medium 0.5-2Hz (MF), high 2-6Hz (HF)) as well as ankle, knee and hip joint kinematics were assessed. Soleus spinal excitability was determined by H/M-recruitment curves (H/M-ratios). Results Compared to NL, OL caused an increase in ankle joint excursion, COP HF domain and H/M-ratio. Concomitantly, hip joint excursion and COP LF decreased. Compared to NL, UL caused modulations in the opposite direction: UL decreased ankle joint excursions, COP HF and H/M-ratio. Collaterally, hip joint excursion and COP LF increased. COP was augmented both in UL and in OL compared to NL. Conclusion Subjects achieved postural stability in OL and UL with greater difficulty compared to NL. Reduced postural control was accompanied by modified balance strategies and compensatory reflex activation. With increasing load, a shift from hip to ankle strategy was observed. Accompanying, COP frequency distribution shifted from LF to HF and spinal excitability was enhanced. It is suggested that in OL, augmented ankle joint torques are compensated by quick reflex-induced postural reactions in distal muscles. Contrarily, UL is associated with diminished joint torques and thus, postural equilibrium may be controlled by the proximal

  15. Effect of initial conditions on combustion generated loads

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

    Tieszen, S.R.

    1991-01-01

    This analytical study examines the effect of initial thermodynamic conditions on the loads generated by the combustion of homogeneous hydrogen-air-steam mixtures. The effect of initial temperature, pressure, hydrogen concentration, and steam concentration is evaluated for two cases, (1) constant volume and (2) constant initial pressure. For each case, the Adiabatic, Isochoric, Complete Combustion (AICC), Chapman-Jouguet (CJ), and normally reflected CJ pressures are calculated for a range of hydrogen and steam concentrations representative of the entire flammable regime. For detonation loads, pressure profiles and time-histories are also evaluated in one-dimensional Cartesian geometry. The results show that to a first approximation, themore » AICC and CJ pressures are directly proportional to the initial density. Increasing the hydrogen concentration up to stoichiometric concentrations significantly increases the AICC, CJ, and reflected CJ pressures. For the constant volume case, the AICC, CJ, and reflected CJ pressures increase with increasing hydrogen concentration on the rich side of stoichiometric concentrations. For the constant initial pressure case, the AICC, CJ and reflected CJ pressures decrease with increasing hydrogen concentration on the rich side of stoichiometric values. The addition of steam decreases the AICC, CJ and reflected CJ pressures for the constant initial pressure case, but increases them for the constant volume case. For detonations, the pressure time-histories can be normalized with the AICC pressure and the reverberation time for Cartesian geometry. 35 refs., 16 figs.« less

  16. Hot Cell Installation and Demonstration of the Severe Accident Test Station

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

    Linton, Kory D.; Burns, Zachary M.; Terrani, Kurt A.

    A Severe Accident Test Station (SATS) capable of examining the oxidation kinetics and accident response of irradiated fuel and cladding materials for design basis accident (DBA) and beyond design basis accident (BDBA) scenarios has been successfully installed and demonstrated in the Irradiated Fuels Examination Laboratory (IFEL), a hot cell facility at Oak Ridge National Laboratory. The two test station modules provide various temperature profiles, steam, and the thermal shock conditions necessary for integral loss of coolant accident (LOCA) testing, defueled oxidation quench testing and high temperature BDBA testing. The installation of the SATS system restores the domestic capability to examinemore » postulated and extended LOCA conditions on spent fuel and cladding and provides a platform for evaluation of advanced fuel and accident tolerant fuel (ATF) cladding concepts. This document reports on the successful in-cell demonstration testing of unirradiated Zircaloy-4. It also contains descriptions of the integral test facility capabilities, installation activities, and out-of-cell benchmark testing to calibrate and optimize the system.« less

  17. 49 CFR 233.5 - Accidents resulting from signal failure.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Accidents resulting from signal failure. 233.5... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SIGNAL SYSTEMS REPORTING REQUIREMENTS § 233.5 Accidents resulting... required by part 236 of this title that results in a more favorable aspect than intended or other condition...

  18. 49 CFR 233.5 - Accidents resulting from signal failure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 4 2013-10-01 2013-10-01 false Accidents resulting from signal failure. 233.5... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SIGNAL SYSTEMS REPORTING REQUIREMENTS § 233.5 Accidents resulting... required by part 236 of this title that results in a more favorable aspect than intended or other condition...

  19. 49 CFR 233.5 - Accidents resulting from signal failure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 4 2014-10-01 2014-10-01 false Accidents resulting from signal failure. 233.5... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SIGNAL SYSTEMS REPORTING REQUIREMENTS § 233.5 Accidents resulting... required by part 236 of this title that results in a more favorable aspect than intended or other condition...

  20. 49 CFR 233.5 - Accidents resulting from signal failure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 4 2012-10-01 2012-10-01 false Accidents resulting from signal failure. 233.5... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SIGNAL SYSTEMS REPORTING REQUIREMENTS § 233.5 Accidents resulting... required by part 236 of this title that results in a more favorable aspect than intended or other condition...

  1. 49 CFR 233.5 - Accidents resulting from signal failure.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Accidents resulting from signal failure. 233.5... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION SIGNAL SYSTEMS REPORTING REQUIREMENTS § 233.5 Accidents resulting... required by part 236 of this title that results in a more favorable aspect than intended or other condition...

  2. Multiscale Multiphysics Developments for Accident Tolerant Fuel Concepts

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

    Gamble, K. A.; Hales, J. D.; Yu, J.

    2015-09-01

    U 3Si 2 and iron-chromium-aluminum (Fe-Cr-Al) alloys are two of many proposed accident-tolerant fuel concepts for the fuel and cladding, respectively. The behavior of these materials under normal operating and accident reactor conditions is not well known. As part of the Department of Energy’s Accident Tolerant Fuel High Impact Problem program significant work has been conducted to investigate the U 3Si 2 and FeCrAl behavior under reactor conditions. This report presents the multiscale and multiphysics effort completed in fiscal year 2015. The report is split into four major categories including Density Functional Theory Developments, Molecular Dynamics Developments, Mesoscale Developments, andmore » Engineering Scale Developments. The work shown here is a compilation of a collaborative effort between Idaho National Laboratory, Los Alamos National Laboratory, Argonne National Laboratory and Anatech Corp.« less

  3. A path-dependent fatigue crack propagation model under non-proportional modes I and III loading conditions

    DOE PAGES

    Mei, J.; Dong, P.; Kalnaus, S.; ...

    2017-07-21

    It has been well established that fatigue damage process is load-path dependent under non-proportional multi-axial loading conditions. Most of studies to date have been focusing on interpretation of S-N based test data by constructing a path-dependent fatigue damage model. Our paper presents a two-parameter mixed-mode fatigue crack growth model which takes into account of crack growth dependency on both load path traversed and a maximum effective stress intensity attained in a stress intensity factor plane (e.g.,KI-KIII plane). Furthermore, by taking advantage of a path-dependent maximum range (PDMR) cycle definition (Dong et al., 2010; Wei and Dong, 2010), the two parametersmore » are formulated by introducing a moment of load path (MLP) based equivalent stress intensity factor range (ΔKNP) and a maximum effective stress intensity parameter KMax incorporating an interaction term KI·KIII. To examine the effectiveness of the proposed model, two sets of crack growth rate test data are considered. The first set is obtained as a part of this study using 304 stainless steel disk specimens subjected to three combined non-proportional modes I and III loading conditions (i.e., with a phase angle of 0°, 90°, and 180°). The second set was obtained by Feng et al. (2007) using 1070 steel disk specimens subjected to similar types of non-proportional mixed-mode conditions. Once the proposed two-parameter non-proportional mixed-mode crack growth model is used, it is shown that a good correlation can be achieved for both sets of the crack growth rate test data.« less

  4. A path-dependent fatigue crack propagation model under non-proportional modes I and III loading conditions

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

    Mei, J.; Dong, P.; Kalnaus, S.

    It has been well established that fatigue damage process is load-path dependent under non-proportional multi-axial loading conditions. Most of studies to date have been focusing on interpretation of S-N based test data by constructing a path-dependent fatigue damage model. Our paper presents a two-parameter mixed-mode fatigue crack growth model which takes into account of crack growth dependency on both load path traversed and a maximum effective stress intensity attained in a stress intensity factor plane (e.g.,KI-KIII plane). Furthermore, by taking advantage of a path-dependent maximum range (PDMR) cycle definition (Dong et al., 2010; Wei and Dong, 2010), the two parametersmore » are formulated by introducing a moment of load path (MLP) based equivalent stress intensity factor range (ΔKNP) and a maximum effective stress intensity parameter KMax incorporating an interaction term KI·KIII. To examine the effectiveness of the proposed model, two sets of crack growth rate test data are considered. The first set is obtained as a part of this study using 304 stainless steel disk specimens subjected to three combined non-proportional modes I and III loading conditions (i.e., with a phase angle of 0°, 90°, and 180°). The second set was obtained by Feng et al. (2007) using 1070 steel disk specimens subjected to similar types of non-proportional mixed-mode conditions. Once the proposed two-parameter non-proportional mixed-mode crack growth model is used, it is shown that a good correlation can be achieved for both sets of the crack growth rate test data.« less

  5. 32 CFR 634.30 - Use of traffic accident investigation report data.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... interviews of victims and witnesses and in collection and preservation of physical evidence, should support... accidents. When frequent accidents occur at a location, the conditions at the location and the types of...

  6. 32 CFR 634.30 - Use of traffic accident investigation report data.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... interviews of victims and witnesses and in collection and preservation of physical evidence, should support... accidents. When frequent accidents occur at a location, the conditions at the location and the types of...

  7. 32 CFR 634.30 - Use of traffic accident investigation report data.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... interviews of victims and witnesses and in collection and preservation of physical evidence, should support... accidents. When frequent accidents occur at a location, the conditions at the location and the types of...

  8. Who by accident? The social morphology of car accidents.

    PubMed

    Factor, Roni; Yair, Gad; Mahalel, David

    2010-09-01

    Prior studies in the sociology of accidents have shown that different social groups have different rates of accident involvement. This study extends those studies by implementing Bourdieu's relational perspective of social space to systematically explore the homology between drivers' social characteristics and their involvement in specific types of motor vehicle accident. Using a large database that merges official Israeli road-accident records with socioeconomic data from two censuses, this research maps the social order of road accidents through multiple correspondence analysis. Extending prior studies, the results show that different social groups indeed tend to be involved in motor vehicle accidents of different types and severity. For example, we find that drivers from low socioeconomic backgrounds are overinvolved in severe accidents with fatal outcomes. The new findings reported here shed light on the social regularity of road accidents and expose new facets in the social organization of death. © 2010 Society for Risk Analysis.

  9. Novel instrument for characterizing comprehensive physical properties under multi-mechanical loads and multi-physical field coupling conditions

    NASA Astrophysics Data System (ADS)

    Liu, Changyi; Zhao, Hongwei; Ma, Zhichao; Qiao, Yuansen; Hong, Kun; Ren, Zhuang; Zhang, Jianhai; Pei, Yongmao; Ren, Luquan

    2018-02-01

    Functional materials represented by ferromagnetics and ferroelectrics are widely used in advanced sensor and precision actuation due to their special characterization under coupling interactions of complex loads and external physical fields. However, the conventional devices for material characterization can only provide a limited type of loads and physical fields and cannot simulate the actual service conditions of materials. A multi-field coupling instrument for characterization has been designed and implemented to overcome this barrier and measure the comprehensive physical properties under complex service conditions. The testing forms include tension, compression, bending, torsion, and fatigue in mechanical loads, as well as different external physical fields, including electric, magnetic, and thermal fields. In order to offer a variety of information to reveal mechanical damage or deformation forms, a series of measurement methods at the microscale are integrated with the instrument including an indentation unit and in situ microimaging module. Finally, several coupling experiments which cover all the loading and measurement functions of the instrument have been implemented. The results illustrate the functions and characteristics of the instrument and then reveal the variety in mechanical and electromagnetic properties of the piezoelectric transducer ceramic, TbDyFe alloy, and carbon fiber reinforced polymer under coupling conditions.

  10. Investigating accidents involving aircraft manufactured from polymer composite materials

    NASA Astrophysics Data System (ADS)

    Dunn, Leigh

    This study looks into the examination of polymer composite wreckage from the perspective of the aircraft accident investigator. It develops an understanding of the process of wreckage examination as well as identifying the potential for visual and macroscopic interpretation of polymer composite aircraft wreckage. The in-field examination of aircraft wreckage, and subsequent interpretations of material failures, can be a significant part of an aircraft accident investigation. As the use of composite materials in aircraft construction increases, the understanding of how macroscopic failure characteristics of composite materials may aid the field investigator is becoming of increasing importance.. The first phase of this research project was to explore how investigation practitioners conduct wreckage examinations. Four accident investigation case studies were examined. The analysis of the case studies provided a framework of the wreckage examination process. Subsequently, a literature survey was conducted to establish the current level of knowledge on the visual and macroscopic interpretation of polymer composite failures. Relevant literature was identified and a compendium of visual and macroscopic characteristics was created. Two full-scale polymer composite wing structures were loaded statically, in an upward bending direction, until each wing structure fractured and separated. The wing structures were subsequently examined for the existence of failure characteristics. The examination revealed that whilst characteristics were present, the fragmentation of the structure destroyed valuable evidence. A hypothetical accident scenario utilising the fractured wing structures was developed, which UK government accident investigators subsequently investigated. This provided refinement to the investigative framework and suggested further guidance on the interpretation of polymer composite failures by accident investigators..

  11. Structural Performance of a Hybrid FRP-Aluminum Modular Triangular Truss System Subjected to Various Loading Conditions

    PubMed Central

    Zhang, Dongdong; Huang, Yaxin; Zhao, Qilin; Li, Fei; Gao, Yifeng

    2014-01-01

    A novel hybrid FRP-aluminum truss system has been employed in a two-rut modular bridge superstructure composed of twin inverted triangular trusses. The actual flexural behavior of a one-rut truss has been previously investigated under the on-axis loading test; however, the structural performance of the one-rut truss subjected to an off-axis load is still not fully understood. In this paper, a geometrical linear finite element model is introduced and validated by the on-axis loading test; the structural performance of the one-rut truss subjected to off-axis load was numerically obtained; the dissimilarities of the structural performance between the two different loading cases are investigated in detail. The results indicated that (1) the structural behavior of the off-axis load differs from that of the on-axis load, and the off-axis load is the critical loading condition controlling the structural performance of the triangular truss; (2) under the off-axis load, the FRP trussed members and connectors bear certain out-of-plane bending moments and are subjected to a complicated stress state; and (3) the stress state of these members does not match that of the initial design, and optimization for the redesign of these members is needed, especially for the pretightened teeth connectors. PMID:25254254

  12. [Severe parachuting accident. Analysis of 122 cases].

    PubMed

    Krauss, U; Mischkowsky, T

    1993-06-01

    Based on a population of 122 severely injured patients the causes of paragliding accidents and the patterns of injury are analyzed. A questionnaire is used to establish a sport-specific profile for the paragliding pilot. The lower limbs (55.7%) and the lower parts of the spine (45.9%) are the most frequently injured parts of the body. There is a high risk of multiple injuries after a single accident because of the tremendous axial power. The standard of equipment is good in over 90% of the cases. Insufficient training and failure to take account of geographical and meteorological conditions are the main determinants of accidents sustained by paragliders, most of whom are young. Nevertheless, 80% of our patients want to continue paragliding. Finally some advice is given on how to prevent paragliding accidents and injuries.

  13. Uncertainty analysis of accident notification time and emergency medical service response time in work zone traffic accidents.

    PubMed

    Meng, Qiang; Weng, Jinxian

    2013-01-01

    Taking into account the uncertainty caused by exogenous factors, the accident notification time (ANT) and emergency medical service (EMS) response time were modeled as 2 random variables following the lognormal distribution. Their mean values and standard deviations were respectively formulated as the functions of environmental variables including crash time, road type, weekend, holiday, light condition, weather, and work zone type. Work zone traffic accident data from the Fatality Analysis Report System between 2002 and 2009 were utilized to determine the distributions of the ANT and the EMS arrival time in the United States. A mixed logistic regression model, taking into account the uncertainty associated with the ANT and the EMS response time, was developed to estimate the risk of death. The results showed that the uncertainty of the ANT was primarily influenced by crash time and road type, whereas the uncertainty of EMS response time is greatly affected by road type, weather, and light conditions. In addition, work zone accidents occurring during a holiday and in poor light conditions were found to be statistically associated with a longer mean ANT and longer EMS response time. The results also show that shortening the ANT was a more effective approach in reducing the risk of death than the EMS response time in work zones. To shorten the ANT and the EMS response time, work zone activities are suggested to be undertaken during non-holidays, during the daytime, and in good weather and light conditions.

  14. Cognitive load and task condition in event- and time-based prospective memory: an experimental investigation.

    PubMed

    Khan, Azizuddin; Sharma, Narendra K; Dixit, Shikha

    2008-09-01

    Prospective memory is memory for the realization of delayed intention. Researchers distinguish 2 kinds of prospective memory: event- and time-based (G. O. Einstein & M. A. McDaniel, 1990). Taking that distinction into account, the present authors explored participants' comparative performance under event- and time-based tasks. In an experimental study of 80 participants, the authors investigated the roles of cognitive load and task condition in prospective memory. Cognitive load (low vs. high) and task condition (event- vs. time-based task) were the independent variables. Accuracy in prospective memory was the dependent variable. Results showed significant differential effects under event- and time-based tasks. However, the effect of cognitive load was more detrimental in time-based prospective memory. Results also revealed that time monitoring is critical in successful performance of time estimation and so in time-based prospective memory. Similarly, participants' better performance on the event-based prospective memory task showed that they acted on the basis of environment cues. Event-based prospective memory was environmentally cued; time-based prospective memory required self-initiation.

  15. Radiation protection issues on preparedness and response for a severe nuclear accident: experiences of the Fukushima accident.

    PubMed

    Homma, T; Takahara, S; Kimura, M; Kinase, S

    2015-06-01

    Radiation protection issues on preparedness and response for a severe nuclear accident are discussed in this paper based on the experiences following the accident at Fukushima Daiichi nuclear power plant. The criteria for use in nuclear emergencies in the Japanese emergency preparedness guide were based on the recommendations of International Commission of Radiological Protection (ICRP) Publications 60 and 63. Although the decision-making process for implementing protective actions relied heavily on computer-based predictive models prior to the accident, urgent protective actions, such as evacuation and sheltering, were implemented effectively based on the plant conditions. As there were no recommendations and criteria for long-term protective actions in the emergency preparedness guide, the recommendations of ICRP Publications 103, 109, and 111 were taken into consideration in determining the temporary relocation of inhabitants of heavily contaminated areas. These recommendations were very useful in deciding the emergency protective actions to take in the early stages of the Fukushima accident. However, some suggestions have been made for improving emergency preparedness and response in the early stages of a severe nuclear accident. © The Chartered Institution of Building Services Engineers 2014.

  16. Constructing An Event Based Aerosol Product Under High Aerosol Loading Conditions

    NASA Astrophysics Data System (ADS)

    Levy, R. C.; Shi, Y.; Mattoo, S.; Remer, L. A.; Zhang, J.

    2016-12-01

    High aerosol loading events, such as the Indonesia's forest fire in Fall 2015 or the persistent wintertime haze near Beijing, gain tremendous interests due to their large impact on regional visibility and air quality. Understanding the optical properties of these events and further being able to simulate and predict these events are beneficial. However, it is a great challenge to consistently identify and then retrieve aerosol optical depth (AOD) from passive sensors during heavy aerosol events. Some reasons include:1). large differences between optical properties of high-loading aerosols and those under normal conditions, 2) spectral signals of optically thick aerosols can be mistaken with surface depending on aerosol types, and 3) Extremely optically thick aerosol plumes can also be misidentified as clouds due to its high optical thickness. Thus, even under clear-sky conditions, the global distribution of extreme aerosol events is not well captured in datasets such as the MODIS Dark-Target (DT) aerosol product. In this study, with the synthetic use of OMI Aerosol Index, MODIS cloud product, and operational DT product, the heavy smoke events over the seven sea region are identified and retrieved over the dry season. An event based aerosol product that would compensate the standard "global" aerosol retrieval will be created and evaluated. The impact of missing high AOD retrievals on the regional aerosol climatology will be studied using this newly developed research product.

  17. Recreational Boat Safety Collision Research - Phase 2. Volume 2. Collision Accident Investigations - 1975

    DTIC Science & Technology

    1976-07-01

    Collisfon - .t tone person in a runabout wus pulling a skier and was turned, looking aft. He hit a johnboat. Thw ;ohnboat...based on the narrotive, the boat load distribution, and knowledge of the boat charactens;, .: From the load dstribution, it can be assumed that the boat...visibility) and the operator’s lack of knowledge of where he was and the characteristics of this harbor were the primary causes of this accident, along with

  18. Indonesian Sea Accident Analysis (Case Study From 2003 – 2013)

    NASA Astrophysics Data System (ADS)

    Arya Dewanto, Y.; Faturachman, D.

    2018-03-01

    There are so many accidents in sea transportation in Indonesia. Most of the accidents happen because of low concern aspects of the safety and security of the crew. In sailing, a man as transport users to interact with the ship and the surrounding environment (including other ships, cruise lines, ports, and the situation of local conditions). These interactions are sometimes very complex and related to various aspects of. Aware of the multiplicity of aspects related to the third of these factors, seeking the safety of cruise through a reduction in the number of accidents and the risk of death and serious injuries due to accidents and goods transported is certainly not enough attempted through mono-sector approach, but rather takes a multi-sector approach to the efforts. In this paper, we described the Indonesian Sea Transportation accident analysis for eleven years divided into four items: total of ship accident type, ship accident factor, total of casualties, region of ship accidents. All data founded from Marine Court (Mahkamah Pelayaran). From that 4 items we can find Indonesia Sea Accident Analysis from 2003-2013.

  19. 76 FR 25648 - Special Conditions: Gulfstream Model GVI Airplane; Limit Engine Torque Loads for Sudden Engine...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-05

    ... dynamic loads resulting from: (a) The loss of any fan, compressor, or turbine blade; and (b) Separately... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 25 [Docket No. NM454 Special Conditions No. 25-11-11-SC] Special Conditions: Gulfstream Model GVI Airplane; Limit Engine Torque...

  20. [A large-scale accident in Alpine terrain].

    PubMed

    Wildner, M; Paal, P

    2015-02-01

    Due to the geographical conditions, large-scale accidents amounting to mass casualty incidents (MCI) in Alpine terrain regularly present rescue teams with huge challenges. Using an example incident, specific conditions and typical problems associated with such a situation are presented. The first rescue team members to arrive have the elementary tasks of qualified triage and communication to the control room, which is required to dispatch the necessary additional support. Only with a clear "concept", to which all have to adhere, can the subsequent chaos phase be limited. In this respect, a time factor confounded by adverse weather conditions or darkness represents enormous pressure. Additional hazards are frostbite and hypothermia. If priorities can be established in terms of urgency, then treatment and procedure algorithms have proven successful. For evacuation of causalities, a helicopter should be strived for. Due to the low density of hospitals in Alpine regions, it is often necessary to distribute the patients over a wide area. Rescue operations in Alpine terrain have to be performed according to the particular conditions and require rescue teams to have specific knowledge and expertise. The possibility of a large-scale accident should be considered when planning events. With respect to optimization of rescue measures, regular training and exercises are rational, as is the analysis of previous large-scale Alpine accidents.

  1. Reactivity Insertion Accident (RIA) Capability Status in the BISON Fuel Performance Code

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

    Williamson, Richard L.; Folsom, Charles Pearson; Pastore, Giovanni

    2016-05-01

    One of the Challenge Problems being considered within CASL relates to modelling and simulation of Light Water Reactor LWR) fuel under Reactivity Insertion Accident (RIA) conditions. BISON is the fuel performance code used within CASL for LWR fuel under both normal operating and accident conditions, and thus must be capable of addressing the RIA challenge problem. This report outlines required BISON capabilities for RIAs and describes the current status of the code. Information on recent accident capability enhancements, application of BISON to a RIA benchmark exercise, and plans for validation to RIA behavior are included.

  2. Core cooling under accident conditions at the high-flux beam reactor

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

    Tichler, P.; Cheng, L.; Fauske, H.

    The High-Flux Beam Reactor (HFBR) at Brookhaven National Laboratory (BNL) is cooled and moderated by heavy water and contains {sup 235}U in the form of narrow-channel, parallel-plate-type fuel elements. During normal operation, the flow direction is downward through the core. This flow direction is maintained at a reduced flow rate during routine shutdown and on loss of commercial power by means of redundant pumps and power supplies. However, in certain accident scenarios, e.g. loss-of-coolant accidents (LOCAs), all forced-flow cooling is lost. Although there was experimental evidence during the reactor design period (1958-1963) that the heat removal capacity in the fullymore » developed natural circulation cooling mode was relatively high, it was not possible to make a confident prediction of the heat removal capacity during the transition from downflow to natural circulation. Accordingly, a test program was initiated using an electrically heated section to simulate the fuel channel and a cooling loop to simulate the balance of the primary cooling system.« less

  3. Nuclear fuel in a reactor accident.

    PubMed

    Burns, Peter C; Ewing, Rodney C; Navrotsky, Alexandra

    2012-03-09

    Nuclear accidents that lead to melting of a reactor core create heterogeneous materials containing hundreds of radionuclides, many with short half-lives. The long-lived fission products and transuranium elements within damaged fuel remain a concern for millennia. Currently, accurate fundamental models for the prediction of release rates of radionuclides from fuel, especially in contact with water, after an accident remain limited. Relatively little is known about fuel corrosion and radionuclide release under the extreme chemical, radiation, and thermal conditions during and subsequent to a nuclear accident. We review the current understanding of nuclear fuel interactions with the environment, including studies over the relatively narrow range of geochemical, hydrological, and radiation environments relevant to geological repository performance, and discuss priorities for research needed to develop future predictive models.

  4. Occupational accidents in artisanal mining in Katanga, D.R.C.

    PubMed

    Elenge, Myriam; Leveque, Alain; De Brouwer, Christophe

    2013-04-01

    This study focuses on accidents in artisanal mining, to support policies improving miners' employability. Based on a questionnaire administered in November 2009 to a sample of 180 miners from the artisanal mining of LUPOTO, in the Province of Katanga, we explored significant trends between the accidents and their consequences and behavioral or sociological variables. During the 12 months preceding the study, 392 accidents occurred, affecting 72.2% of miners. Tools handling represents 51.5%, of the accidents' causes, followed by handling heavy loads (32.9%). Factors such as age, seniority or apprenticeship did not generate significant differences. Contusions were the most common injuries (50.2%), followed by wounds (44.4%). These injuries were located in upper limbs (50.5%) and in lower limbs (29.3%). 80.5% of miners were cared for by their colleagues and 50% of them could not work for more than 3 days. Physical sequelae were reported by 19% of the injured miners. Many surveys related to accidents in the area of artisanal mining report such high frequency. The unsuitability of tools to jobs to be done is usually raised as one of the major causes of accidents. The lack of differentiation of the tasks carried out in relation to age is another factor explaining the lack of protective effect of seniority as it minimizes the contribution of experience in the worker's safety. The apprenticeship reported is inadequate; it is rather a learning by doing than anything else. That is why it lacks protective effect. Low income combined with precariousness of artisanal mining are likely to explain the low level of work stoppages. Tools improvement associated with adequate training seem to be the basis of accident prevention. Availability of suitable medical care should improve artisanal miners' recovery after accidents.

  5. Laser-heating and Radiance Spectrometry for the Study of Nuclear Materials in Conditions Simulating a Nuclear Power Plant Accident.

    PubMed

    Manara, Dario; Soldi, Luca; Mastromarino, Sara; Boboridis, Kostantinos; Robba, Davide; Vlahovic, Luka; Konings, Rudy

    2017-12-14

    Major and severe accidents have occurred three times in nuclear power plants (NPPs), at Three Mile Island (USA, 1979), Chernobyl (former USSR, 1986) and Fukushima (Japan, 2011). Research on the causes, dynamics, and consequences of these mishaps has been performed in a few laboratories worldwide in the last three decades. Common goals of such research activities are: the prevention of these kinds of accidents, both in existing and potential new nuclear power plants; the minimization of their eventual consequences; and ultimately, a full understanding of the real risks connected with NPPs. At the European Commission Joint Research Centre's Institute for Transuranium Elements, a laser-heating and fast radiance spectro-pyrometry facility is used for the laboratory simulation, on a small scale, of NPP core meltdown, the most common type of severe accident (SA) that can occur in a nuclear reactor as a consequence of a failure of the cooling system. This simulation tool permits fast and effective high-temperature measurements on real nuclear materials, such as plutonium and minor actinide-containing fission fuel samples. In this respect, and in its capability to produce large amount of data concerning materials under extreme conditions, the current experimental approach is certainly unique. For current and future concepts of NPP, example results are presented on the melting behavior of some different types of nuclear fuels: uranium-plutonium oxides, carbides, and nitrides. Results on the high-temperature interaction of oxide fuels with containment materials are also briefly shown.

  6. Laser-heating and Radiance Spectrometry for the Study of Nuclear Materials in Conditions Simulating a Nuclear Power Plant Accident

    PubMed Central

    Manara, Dario; Soldi, Luca; Mastromarino, Sara; Boboridis, Kostantinos; Robba, Davide; Vlahovic, Luka; Konings, Rudy

    2017-01-01

    Major and severe accidents have occurred three times in nuclear power plants (NPPs), at Three Mile Island (USA, 1979), Chernobyl (former USSR, 1986) and Fukushima (Japan, 2011). Research on the causes, dynamics, and consequences of these mishaps has been performed in a few laboratories worldwide in the last three decades. Common goals of such research activities are: the prevention of these kinds of accidents, both in existing and potential new nuclear power plants; the minimization of their eventual consequences; and ultimately, a full understanding of the real risks connected with NPPs. At the European Commission Joint Research Centre's Institute for Transuranium Elements, a laser-heating and fast radiance spectro-pyrometry facility is used for the laboratory simulation, on a small scale, of NPP core meltdown, the most common type of severe accident (SA) that can occur in a nuclear reactor as a consequence of a failure of the cooling system. This simulation tool permits fast and effective high-temperature measurements on real nuclear materials, such as plutonium and minor actinide-containing fission fuel samples. In this respect, and in its capability to produce large amount of data concerning materials under extreme conditions, the current experimental approach is certainly unique. For current and future concepts of NPP, example results are presented on the melting behavior of some different types of nuclear fuels: uranium-plutonium oxides, carbides, and nitrides. Results on the high-temperature interaction of oxide fuels with containment materials are also briefly shown. PMID:29286382

  7. Factors associated with urban non-fatal road-accident severity.

    PubMed

    Potoglou, Dimitris; Carlucci, Fabio; Cirà, Andrea; Restaino, Marialuisa

    2018-02-05

    This paper reports on the factors associated with non-fatal urban-road accident severity. Data on accidents were gathered from the local traffic police in the City of Palermo, one of the six most populated cities in Italy. Findings from a mixed-effects logistic-regression model suggest that accident severity increases when two young drivers are involved, road traffic conditions are light/normal and when vehicles crash on a two-way road or carriageway. Speeding is more likely to cause slight or serious injury even when compared to a vehicle moving towards the opposite direction of traffic. An accident during the summer is more likely to result in a slight or serious injury than an accident during the winter, which is in line with evidence from Southern Europe and the Middle East. Finally, the severity of non-fatal accident injuries in an urban area of Southern Europe was significantly associated with speeding, the age of the driver and seasonality.

  8. Residual stress analysis on tensile MMC specimens after loading/unloading tests in several conditions

    NASA Astrophysics Data System (ADS)

    Giuliani, Alessandra; Albertini, Gianni; Manescu, Adrian

    2004-07-01

    Residual stresses have been investigated in samples made of AA6061+22% Al2O3 in order to correlate microstructural characteristics with mechanical performances. In particular, the possible occurrence of a brittle fracture induced by an excessive load transfer from the matrix to the reinforcement was investigated. To this end, macrostresses and microstresses were analysed. A neutron diffraction test on 12 specimens submitted to several loading/unloading conditions at different temperatures was performed. These measurements aimed to establish the optimal temperature for the initial extruded billet in pre-heating stage, before forging the final wheel hub.

  9. The influence of supercritical carbon dioxide (SC-CO2) processing conditions on drug loading and physicochemical properties.

    PubMed

    Ahern, Robert J; Crean, Abina M; Ryan, Katie B

    2012-12-15

    Poor water solubility of drugs can complicate their commercialisation because of reduced drug oral bioavailability. Formulation strategies such as increasing the drug surface area are frequently employed in an attempt to increase dissolution rate and hence, improve oral bioavailability. Maximising the drug surface area exposed to the dissolution medium can be achieved by loading drug onto a high surface area carrier like mesoporous silica (SBA-15). The aim of this work was to investigate the impact of altering supercritical carbon dioxide (SC-CO(2)) processing conditions, in an attempt to enhance drug loading onto SBA-15 and increase the drug's dissolution rate. Other formulation variables such as the mass ratio of drug to SBA-15 and the procedure for combining the drug and SBA-15 were also investigated. A model drug with poor water solubility, fenofibrate, was selected for this study. High drug loading efficiencies were obtained using SC-CO(2), which were influenced by the processing conditions employed. Fenofibrate release rate was enhanced greatly after loading onto mesoporous silica. The results highlighted the potential of this SC-CO(2) drug loading approach to improve the oral bioavailability of poorly water soluble drugs. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Mechanical stability analysis on spherical sandwich sheet at low temperature loading conditions

    NASA Astrophysics Data System (ADS)

    Wang, Shanshuai; Li, Shuhui; Li, Zhimin

    2013-12-01

    The spherical sandwich sheet (S-S-S) is generally used in the aerospace industry, for example, the airplane, the rocket's fairing, the spacecraft and the satellite for the purpose of heat-insulation, weight-saving and dimension-reducing. The stability of the S-S-S is of general concern because of its particularly thin but large size. For some S-S-S used in fuel tank storing liquid oxygen of the rocket, it must be facing low temperature down to about -183 °C. Low temperature condition affects the stability of the S-S-S and then causes buckling of the structure. In this paper, a finite element (FE) model is established for evaluating the stability of the S-S-S via the sequential coupling mode. The material mechanical properties related to temperature are concerned in the FE model. The buckling modes and critical buckling loading are predicted accurately, since the FE model includes heat transfer simulating, thermal stress computing, buckling and post buckling process. It is found that the thermal stress generated from the low temperature loading reduces the critical buckling loading and changes the buckling modes of the S-S-S.

  11. The Fukushima radiation accident: consequences for radiation accident medical management.

    PubMed

    Meineke, Viktor; Dörr, Harald

    2012-08-01

    The March 2011 radiation accident in Fukushima, Japan, is a textbook example of a radiation accident of global significance. In view of the global dimensions of the accident, it is important to consider the lessons learned. In this context, emphasis must be placed on consequences for planning appropriate medical management for radiation accidents including, for example, estimates of necessary human and material resources. The specific characteristics of the radiation accident in Fukushima are thematically divided into five groups: the exceptional environmental influences on the Fukushima radiation accident, particular circumstances of the accident, differences in risk perception, changed psychosocial factors in the age of the Internet and globalization, and the ignorance of the effects of ionizing radiation both among the general public and health care professionals. Conclusions like the need for reviewing international communication, interfacing, and interface definitions will be drawn from the Fukushima radiation accident.

  12. Field Investigation of a Roof Fall Accident and Large Roadway Deformation Under Geologically Complex Conditions in an Underground Coal Mine

    NASA Astrophysics Data System (ADS)

    Wang, Hongwei; Xue, Sheng; Jiang, Yaodong; Deng, Daixin; Shi, Suzhen; Zhang, Dengqiang

    2018-06-01

    An investigation was undertaken to study the characteristics of large roadway deformation and driving force of roof fall in a geologically complex zone at Huangyanhui underground coal mine, Shanxi Province, China, and to determine the main factors contributing to a roof fall accident that occurred in this mine. A series of field tests were conducted in the mine to study the geological structures, in situ stress, excavation-damaged zones of the roadway, roof-to-floor and sidewall convergences, roof separation, bolts loading and island coal pillar stress. The results of these tests have revealed that the driving force of the large roadway deformation and roof fall was not the activation of the karst collapsed pillars or concentration stress in island coal pillar, but high levels of horizontal tectonic stress and fault slip were induced by mining activities.

  13. Criticality conditions of heterogeneous energetic materials under shock loading

    NASA Astrophysics Data System (ADS)

    Nassar, Anas; Rai, Nirmal Kumar; Sen, Oishik; Udaykumar, H. S.

    2017-06-01

    Shock interaction with the microstructural heterogeneities of energetic materials can lead to the formation of locally heated regions known as hot spots. These hot spots are the potential sites where chemical reaction may be initiated. However, the ability of a hot spot to initiate chemical reaction depends on its size, shape and strength (temperature). Previous study by Tarver et al. has shown that there exists a critical size and temperature for a given shape (spherical, cylindrical, and planar) of the hot spot above which reaction initiation is imminent. Tarver et al. assumed a constant temperature variation in the hot spot. However, the meso-scale simulations show that the temperature distribution within a hot spot formed from processes such as void collapse is seldom constant. Also, the shape of a hot spot can be arbitrary. This work is an attempt towards development of a critical hot spot curve which is a function of loading strength, duration and void morphology. To achieve the aforementioned goal, mesoscale simulations are conducted on porous HMX material. The process is repeated for different loading conditions and void sizes. The hot spots formed in the process are examined for criticality depending on whether they will ignite or not. The metamodel is used to obtain criticality curves and is compared with the critical hot spot curve of Tarver et al.

  14. Incidence of posttraumatic stress disorder after traffic accidents in Germany.

    PubMed

    Brand, Stephan; Otte, Dietmar; Petri, Maximilian; Decker, Sebastian; Stübig, Timo; Krettek, Christian; Müller, Christian W

    2014-01-01

    Posttraumatic stress disorder (PTSD) is possibly an overlooked diagnosis of victims suffering from traffic accidents sustaining serious to severe injuries. This paper investigates the incidence of PTSD after traffic accidents in Germany. Data from an accident research unit were analyzed in regard to collision details, and preclinical and clinical data. Preclinical data included details on crash circumstances and estimated injury severity as well as data on victims' conditions (e.g. heart rate, blood pressure, consciousness, breath rate). Clinical data included initial assessment in the emergency department, radiographic diagnoses, and basic life parameters comparable to the preclinical data as well as follow-up data on the daily ward. Data were collected in the German-In-Depth Accident Research study, and included gender, type of accident (e.g. type of vehicle, road conditions, rural or urban area), mental disorder, and AIS (Abbreviated Injury Scale) head score. AIS represent a scoring system to measure the injury severity of traffic accident victims. A total 258 out of 32807 data sets were included in this analysis. Data on accident and victims was collected on scene by specialized teams following established algorithms. Besides higher AIS Head scores for male motorcyclists compared to all other subgroups, no significant correlation was found between the mean maximum AIS score and the occurrence of PTSD. Furthermore, there was no correlation between higher AIS head scores, gender, or involvement in road traffic accidents and PTSD. In our study the overall incidence of PTSD after road traffic accidents was very low (0.78% in a total of 32.807 collected data sets) when compared to other published studies. The reason for this very low incidence of PTSD in our patient sample could be seen in an underestimation of the psychophysiological impact of traffic accidents on patients. Patients suffering from direct experiences of traumatic events such as a traffic accident

  15. Identification of pre-impact conditions of a cyclist involved in a vehicle-bicycle accident using an optimized MADYMO reconstruction combined with motion capture.

    PubMed

    Sun, Jie; Li, Zhengdong; Pan, Shaoyou; Feng, Hao; Shao, Yu; Liu, Ningguo; Huang, Ping; Zou, Donghua; Chen, Yijiu

    2018-05-01

    The aim of the present study was to develop an improved method, using MADYMO multi-body simulation software combined with an optimization method and three-dimensional (3D) motion capture, for identifying the pre-impact conditions of a cyclist (walking or cycling) involved in a vehicle-bicycle accident. First, a 3D motion capture system was used to analyze coupled motions of a volunteer while walking and cycling. The motion capture results were used to define the posture of the human model during walking and cycling simulations. Then, cyclist, bicycle and vehicle models were developed. Pre-impact parameters of the models were treated as unknown design variables. Finally, a multi-objective genetic algorithm, the nondominated sorting genetic algorithm II, was used to find optimal solutions. The objective functions of the walk parameter were significantly lower than cycle parameter; thus, the cyclist was more likely to have been walking with the bicycle than riding the bicycle. In the most closely matched result found, all observed contact points matched and the injury parameters correlated well with the real injuries sustained by the cyclist. Based on the real accident reconstruction, the present study indicates that MADYMO multi-body simulation software, combined with an optimization method and 3D motion capture, can be used to identify the pre-impact conditions of a cyclist involved in a vehicle-bicycle accident. Copyright © 2018. Published by Elsevier Ltd.

  16. GEN-IV Benchmarking of Triso Fuel Performance Models under accident conditions modeling input data

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

    Collin, Blaise Paul

    This document presents the benchmark plan for the calculation of particle fuel performance on safety testing experiments that are representative of operational accidental transients. The benchmark is dedicated to the modeling of fission product release under accident conditions by fuel performance codes from around the world, and the subsequent comparison to post-irradiation experiment (PIE) data from the modeled heating tests. The accident condition benchmark is divided into three parts: • The modeling of a simplified benchmark problem to assess potential numerical calculation issues at low fission product release. • The modeling of the AGR-1 and HFR-EU1bis safety testing experiments. •more » The comparison of the AGR-1 and HFR-EU1bis modeling results with PIE data. The simplified benchmark case, thereafter named NCC (Numerical Calculation Case), is derived from “Case 5” of the International Atomic Energy Agency (IAEA) Coordinated Research Program (CRP) on coated particle fuel technology [IAEA 2012]. It is included so participants can evaluate their codes at low fission product release. “Case 5” of the IAEA CRP-6 showed large code-to-code discrepancies in the release of fission products, which were attributed to “effects of the numerical calculation method rather than the physical model” [IAEA 2012]. The NCC is therefore intended to check if these numerical effects subsist. The first two steps imply the involvement of the benchmark participants with a modeling effort following the guidelines and recommendations provided by this document. The third step involves the collection of the modeling results by Idaho National Laboratory (INL) and the comparison of these results with the available PIE data. The objective of this document is to provide all necessary input data to model the benchmark cases, and to give some methodology guidelines and recommendations in order to make all results suitable for comparison with each other. The participants

  17. Zinc is released by cultured astrocytes as a gliotransmitter under hypoosmotic stress-loaded conditions and regulates microglial activity.

    PubMed

    Segawa, Shohei; Nishiura, Takeshi; Furuta, Takahiro; Ohsato, Yuki; Tani, Misaki; Nishida, Kentaro; Nagasawa, Kazuki

    2014-01-17

    Astrocytes contribute to the maintenance of brain homeostasis via the release of gliotransmitters such as ATP and glutamate. Here we examined whether zinc was released from astrocytes under stress-loaded conditions, and was involved in the regulation of microglial activity as a gliotransmitter. Hypoosmotic stress was loaded to astrocytes using balanced salt solution prepared to 214-314 mOsmol/L, and then intra- and extra-cellular zinc levels were assessed using Newport Green DCF diacetate (NG) and ICP-MS, respectively. Microglial activation by the astrocytic supernatant was assessed by their morphological changes and poly(ADP-ribose) (PAR) polymer accumulation. Exposure of astrocytes to hypoosmotic buffer, increased the extracellular ATP level in osmolarity-dependent manners, indicating a load of hypoosmotic stress. In hypoosmotic stress-loaded astrocytes, there were apparent increases in the intra- and extra-cellular zinc levels. Incubation of microglia in the astrocytic conditioned medium transformed them into the activated "amoeboid" form and induced PAR formation. Administration of an extracellular zinc chelator, CaEDTA, to the astrocytic conditioned medium almost completely prevented the microglial activation. Treatment of astrocytes with an intracellular zinc chelator, TPEN, suppressed the hypoosmotic stress-increased intracellular, but not the extracellular, zinc level, and the increase in the intracellular zinc level was blocked partially by a nitric oxide synthase inhibitor, but not by CaEDTA, indicating that the mechanisms underlying the increases in the intra- and extra-cellular zinc levels might be different. These findings suggest that under hypoosmotic stress-loaded conditions, zinc is released from astrocytes and then plays a primary role in microglial activation as a gliotransmitter. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Fatal accidents in nighttime vs. daytime highway construction work zones.

    PubMed

    Arditi, David; Lee, Dong-Eun; Polat, Gul

    2007-01-01

    Awareness about worker safety in nighttime construction has been a major concern because it is believed that nighttime construction creates hazardous work conditions. However, only a few studies provide valuable comparative information about accident characteristics of nighttime and daytime highway construction activities. This study investigates fatal accidents that occurred in Illinois highway work zones in the period 1996-2001 in order to determine the safety differences between nighttime and daytime highway construction. The lighting and weather conditions were included into the study as control parameters to see their effects on the frequency of fatal accidents occurring in work zones. According to this study, there is evidence that nighttime construction is more hazardous than daytime construction. The inclusion of a weather parameter into the analysis has limited effect on this finding. The study justifies establishing an efficient work zone accident reporting system and taking all necessary measures to enhance safety in nighttime work zones.

  19. Emotion-attention interactions in fear conditioning: Moderation by executive load, neuroticism, and awareness.

    PubMed

    Hur, Juyoen; Iordan, Alexandru D; Berenbaum, Howard; Dolcos, Florin

    2016-12-01

    Despite increasing evidence suggesting interactive effects of emotion and attention on perceptual processing, it still remains unclear how their interplay influences affective learning, such as fear conditioning. In the present study, a conditioning procedure using threat-related conditioned stimuli (CSs) was implemented while executive load and attentional focus were manipulated. The modulation effects of neuroticism and contingency awareness were also examined. Results showed that fear conditioning depended on the available executive resources even with threat-related CSs. In addition, although individuals with high neuroticism showed an enhanced conditioning effect overall, this facilitation effect still depended on the availability of executive resources. Finally, the impact of attentional focus was most evident among individuals with high neuroticism who were aware of the contingency. Overall, the present study demonstrates interactive effects of emotion and attention in fear conditioning, while illuminating mechanisms of individual differences and clarifying the controversial role of contingency awareness in fear conditioning. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Strip Yield Model Numerical Application to Different Geometries and Loading Conditions

    NASA Technical Reports Server (NTRS)

    Hatamleh, Omar; Forman, Royce; Shivakumar, Venkataraman; Lyons, Jed

    2006-01-01

    A new numerical method based on the strip-yield analysis approach was developed for calculating the Crack Tip Opening Displacement (CTOD). This approach can be applied for different crack configurations having infinite and finite geometries, and arbitrary applied loading conditions. The new technique adapts the boundary element / dislocation density method to obtain crack-face opening displacements at any point on a crack, and succeeds by obtaining requisite values as a series of definite integrals, the functional parts of each being evaluated exactly in a closed form.

  1. Physical properties, chemical composition, and cloud forming potential of particulate emissions from a marine diesel engine at various load conditions.

    PubMed

    Petzold, A; Weingartner, E; Hasselbach, J; Lauer, P; Kurok, C; Fleischer, F

    2010-05-15

    Particulate matter (PM) emissions from one serial 4-stroke medium-speed marine diesel engine were measured for load conditions from 10% to 110% in test rig studies using heavy fuel oil (HFO). Testing the engine across its entire load range permitted the scaling of exhaust PM properties with load. Emission factors for particle number, particle mass, and chemical compounds were determined. The potential of particles to form cloud droplets (cloud condensation nuclei, CCN) was calculated from chemical composition and particle size. Number emission factors are (3.43 +/- 1.26) x 10(16) (kg fuel)(-1) at 85-110% load and (1.06 +/- 0.10) x 10(16) (kg fuel)(-1) at 10% load. CCN emission factors of 1-6 x 10(14) (kg fuel)(-1) are at the lower bound of data reported in the literature. From combined thermal and optical methods, black carbon (BC) emission factors of 40-60 mg/(kg fuel) were determined for 85-100% load and 370 mg/(kg fuel) for 10% load. The engine load dependence of the conversion efficiency for fuel sulfur into sulfate of (1.08 +/- 0.15)% at engine idle to (3.85 +/- 0.41)% at cruise may serve as input to global emission calculations for various load conditions.

  2. Major Accidents (Gray Swans) Likelihood Modeling Using Accident Precursors and Approximate Reasoning.

    PubMed

    Khakzad, Nima; Khan, Faisal; Amyotte, Paul

    2015-07-01

    Compared to the remarkable progress in risk analysis of normal accidents, the risk analysis of major accidents has not been so well-established, partly due to the complexity of such accidents and partly due to low probabilities involved. The issue of low probabilities normally arises from the scarcity of major accidents' relevant data since such accidents are few and far between. In this work, knowing that major accidents are frequently preceded by accident precursors, a novel precursor-based methodology has been developed for likelihood modeling of major accidents in critical infrastructures based on a unique combination of accident precursor data, information theory, and approximate reasoning. For this purpose, we have introduced an innovative application of information analysis to identify the most informative near accident of a major accident. The observed data of the near accident were then used to establish predictive scenarios to foresee the occurrence of the major accident. We verified the methodology using offshore blowouts in the Gulf of Mexico, and then demonstrated its application to dam breaches in the United Sates. © 2015 Society for Risk Analysis.

  3. Domino effect in chemical accidents: main features and accident sequences.

    PubMed

    Darbra, R M; Palacios, Adriana; Casal, Joaquim

    2010-11-15

    The main features of domino accidents in process/storage plants and in the transportation of hazardous materials were studied through an analysis of 225 accidents involving this effect. Data on these accidents, which occurred after 1961, were taken from several sources. Aspects analyzed included the accident scenario, the type of accident, the materials involved, the causes and consequences and the most common accident sequences. The analysis showed that the most frequent causes are external events (31%) and mechanical failure (29%). Storage areas (35%) and process plants (28%) are by far the most common settings for domino accidents. Eighty-nine per cent of the accidents involved flammable materials, the most frequent of which was LPG. The domino effect sequences were analyzed using relative probability event trees. The most frequent sequences were explosion→fire (27.6%), fire→explosion (27.5%) and fire→fire (17.8%). Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Analyzing the causation of a railway accident based on a complex network

    NASA Astrophysics Data System (ADS)

    Ma, Xin; Li, Ke-Ping; Luo, Zi-Yan; Zhou, Jin

    2014-02-01

    In this paper, a new model is constructed for the causation analysis of railway accident based on the complex network theory. In the model, the nodes are defined as various manifest or latent accident causal factors. By employing the complex network theory, especially its statistical indicators, the railway accident as well as its key causations can be analyzed from the overall perspective. As a case, the “7.23” China—Yongwen railway accident is illustrated based on this model. The results show that the inspection of signals and the checking of line conditions before trains run played an important role in this railway accident. In conclusion, the constructed model gives a theoretical clue for railway accident prediction and, hence, greatly reduces the occurrence of railway accidents.

  5. Strain Distribution in a Kennedy Class I Implant Assisted Removable Partial Denture under Various Loading Conditions

    PubMed Central

    Shahmiri, Reza; Aarts, John M.; Bennani, Vincent; Swain, Michael V.

    2013-01-01

    Purpose. This in vitro study investigates how unilateral and bilateral occlusal loads are transferred to an implant assisted removable partial denture (IARPD). Materials and Methods. A duplicate model of a Kennedy class I edentulous mandibular arch was made and then a conventional removable partial denture (RPD) fabricated. Two Straumann implants were placed in the second molar region, and the prosthesis was modified to accommodate implant retained ball attachments. Strain gages were incorporated into the fitting surface of both the framework and acrylic to measure microstrain (μStrain). The IARPD was loaded to 120Ns unilaterally and bilaterally in three different loading positions. Statistical analysis was carried out using SPSS version 18.0 (SPSS, Inc., Chicago, IL, USA) with an alpha level of 0.05 to compare the maximum μStrain values of the different loading conditions. Results. During unilateral and bilateral loading the maximum μStrain was predominantly observed in a buccal direction. As the load was moved anteriorly the μStrain increased in the mesial area. Unilateral loading resulted in a twisting of the structure and generated a strain mismatch between the metal and acrylic surfaces. Conclusions. Unilateral loading created lateral and vertical displacement of the IARPD. The curvature of the dental arch resulted in a twisting action which intensified as the unilateral load was moved anteriorly. PMID:23737788

  6. Learning lessons from Natech accidents - the eNATECH accident database

    NASA Astrophysics Data System (ADS)

    Krausmann, Elisabeth; Girgin, Serkan

    2016-04-01

    When natural hazards impact industrial facilities that house or process hazardous materials, fires, explosions and toxic releases can occur. This type of accident is commonly referred to as Natech accident. In order to prevent the recurrence of accidents or to better mitigate their consequences, lessons-learned type studies using available accident data are usually carried out. Through post-accident analysis, conclusions can be drawn on the most common damage and failure modes and hazmat release paths, particularly vulnerable storage and process equipment, and the hazardous materials most commonly involved in these types of accidents. These analyses also lend themselves to identifying technical and organisational risk-reduction measures that require improvement or are missing. Industrial accident databases are commonly used for retrieving sets of Natech accident case histories for further analysis. These databases contain accident data from the open literature, government authorities or in-company sources. The quality of reported information is not uniform and exhibits different levels of detail and accuracy. This is due to the difficulty of finding qualified information sources, especially in situations where accident reporting by the industry or by authorities is not compulsory, e.g. when spill quantities are below the reporting threshold. Data collection has then to rely on voluntary record keeping often by non-experts. The level of detail is particularly non-uniform for Natech accident data depending on whether the consequences of the Natech event were major or minor, and whether comprehensive information was available for reporting. In addition to the reporting bias towards high-consequence events, industrial accident databases frequently lack information on the severity of the triggering natural hazard, as well as on failure modes that led to the hazmat release. This makes it difficult to reconstruct the dynamics of the accident and renders the development of

  7. Building of communication system for nuclear accident emergency disposal based on IP multimedia subsystem

    NASA Astrophysics Data System (ADS)

    Wang, Kang; Gao, Guiqing; Qin, Yuanli; He, Xiangyong

    2018-05-01

    The nuclear accident emergency disposal must be supported by an efficient, real-time modularization and standardization communication system. Based on the analysis of communication system for nuclear accident emergency disposal which included many functions such as the internal and external communication, multiply access supporting and command center. Some difficult problems of the communication system were discussed such as variety access device type, complex composition, high mobility, set up quickly, multiply business support, and so on. Taking full advantages of the IP Multimedia Subsystem (IMS), a nuclear accident emergency communication system was build based on the IMS. It was studied and implemented that some key unit and module functions of communication system were included the system framework implementation, satellite access, short-wave access, load/vehicle-mounted communication units. The application tests showed that the system could provide effective communication support for the nuclear accident emergency disposal, which was of great practical value.

  8. Anthropometric dependence of the response of a thorax FE model under high speed loading: validation and real world accident replication.

    PubMed

    Roth, Sébastien; Torres, Fabien; Feuerstein, Philippe; Thoral-Pierre, Karine

    2013-05-01

    Finite element analysis is frequently used in several fields such as automotive simulations or biomechanics. It helps researchers and engineers to understand the mechanical behaviour of complex structures. The development of computer science brought the possibility to develop realistic computational models which can behave like physical ones, avoiding the difficulties and costs of experimental tests. In the framework of biomechanics, lots of FE models have been developed in the last few decades, enabling the investigation of the behaviour of the human body submitted to heavy damage such as in road traffic accidents or in ballistic impact. In both cases, the thorax/abdomen/pelvis system is frequently injured. The understanding of the behaviour of this complex system is of extreme importance. In order to explore the dynamic response of this system to impact loading, a finite element model of the human thorax/abdomen/pelvis system has, therefore, been developed including the main organs: heart, lungs, kidneys, liver, spleen, the skeleton (with vertebrae, intervertebral discs, ribs), stomach, intestines, muscles, and skin. The FE model is based on a 3D reconstruction, which has been made from medical records of anonymous patients, who have had medical scans with no relation to the present study. Several scans have been analyzed, and specific attention has been paid to the anthropometry of the reconstructed model, which can be considered as a 50th percentile male model. The biometric parameters and laws have been implemented in the dynamic FE code (Radioss, Altair Hyperworks 11©) used for dynamic simulations. Then the 50th percentile model was validated against experimental data available in the literature, in terms of deflection, force, whose curve must be in experimental corridors. However, for other anthropometries (small male or large male models) question about the validation and results of numerical accident replications can be raised. Copyright © 2012 Elsevier

  9. Accident investigation

    NASA Technical Reports Server (NTRS)

    Laynor, William G. Bud

    1987-01-01

    The National Transportation Safety Board (NTSB) has attributed wind shear as a cause or contributing factor in 15 accidents involving transport-categroy airplanes since 1970. Nine of these were nonfatal; but the other six accounted for 440 lives. Five of the fatal accidents and seven of the nonfatal accidents involved encounters with convective downbursts or microbursts. Of other accidents, two which were nonfatal were encounters with a frontal system shear, and one which was fatal was the result of a terrain induced wind shear. These accidents are discussed with reference to helping the aircraft to avoid the wind shear or if impossible to help the pilot to get through the wind shear.

  10. Causes of Coal Mine Accidents in the World and Turkey.

    PubMed

    Küçük, Filiz Çağla Uyanusta; Ilgaz, Aslıhan

    2015-04-01

    Occupational accidents and occupational diseases are common in the mining sector in Turkey and throughout the world. The most common causes of accidents in coal mining are firedamp and dust explosions, landslips, mine fires, and technical failures related to transport and mechanization. An analysis of occupational accidents in the consideration of social and economic factors will let understand the real causes behind these accidents, which are said to happen inevitably due to technical deficiencies or failures. Irregular working conditions, based on profit maximization and cost minimization, are related to strategic operational preferences and public policies. Proving that accidents in mines, where occupational health and safety measures are not implemented and inspections are not done properly or at all, are caused by the fact that production is imposed to be carried out in the fastest, cheapest, and most profitable way will allow us to take steps to prevent further mine accidents.

  11. 76 FR 63822 - Special Conditions: Gulfstream Aerospace LP (GALP) Model G280 Airplane, Limit Engine Torque Loads...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-14

    ... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 25 [Docket No. FAA-2011-1107; Special Conditions No. 25-447-SC] Special Conditions: Gulfstream Aerospace LP (GALP) Model G280 Airplane, Limit Engine Torque Loads for Sudden Engine Stoppage AGENCY: Federal Aviation Administration (FAA...

  12. Bayes classifiers for imbalanced traffic accidents datasets.

    PubMed

    Mujalli, Randa Oqab; López, Griselda; Garach, Laura

    2016-03-01

    Traffic accidents data sets are usually imbalanced, where the number of instances classified under the killed or severe injuries class (minority) is much lower than those classified under the slight injuries class (majority). This, however, supposes a challenging problem for classification algorithms and may cause obtaining a model that well cover the slight injuries instances whereas the killed or severe injuries instances are misclassified frequently. Based on traffic accidents data collected on urban and suburban roads in Jordan for three years (2009-2011); three different data balancing techniques were used: under-sampling which removes some instances of the majority class, oversampling which creates new instances of the minority class and a mix technique that combines both. In addition, different Bayes classifiers were compared for the different imbalanced and balanced data sets: Averaged One-Dependence Estimators, Weightily Average One-Dependence Estimators, and Bayesian networks in order to identify factors that affect the severity of an accident. The results indicated that using the balanced data sets, especially those created using oversampling techniques, with Bayesian networks improved classifying a traffic accident according to its severity and reduced the misclassification of killed and severe injuries instances. On the other hand, the following variables were found to contribute to the occurrence of a killed causality or a severe injury in a traffic accident: number of vehicles involved, accident pattern, number of directions, accident type, lighting, surface condition, and speed limit. This work, to the knowledge of the authors, is the first that aims at analyzing historical data records for traffic accidents occurring in Jordan and the first to apply balancing techniques to analyze injury severity of traffic accidents. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Traffic accidents on expressways: new threat to China.

    PubMed

    Zhao, Jinbao; Deng, Wei

    2012-01-01

    As China is building one of the largest expressway systems in the world, expressway safety problems have become serious concerns to China. This article analyzed the trends in expressway accidents in China from 1995 to 2010 and examined the characteristics of these accidents. Expressway accident data were obtained from the Annual Report for Road Traffic Accidents published by the Ministry of Public Security of China. Expressway mileage data were obtained from the National Statistics Yearbook published by the National Bureau of Statistics of China. Descriptive statistical analyses were conducted based on these data. Expressway deaths increased by 10.2-fold from 616 persons in 1995 to 6300 persons in 2010, and the average annual increase was 17.9 percent over the past 15 years, and the overall other road traffic deaths was -0.33 percent. China's expressway mileage accounted for only 1.85 percent of highway mileage driven in 2010, but expressway deaths made up 13.54 percent of highway traffic deaths. The average annual accident lethality rate [accident deaths/(accident deaths + accident injuries)] for China's expressways was 27.76 percent during the period 1995 to 2010, which was 1.33 times higher than the accident lethality rate of highway traffic accidents. China's government should pay attention to expressway construction and safety interventions during the rapid development period of expressways. Related causes, such as geographic patterns, speeding, weather conditions, and traffic flow composition, need to be studied in the near future. An effective and scientific expressway safety management services system, composed of a speed monitoring system, warning system, and emergency rescue system, should be established in developed and underdeveloped provinces in China to improve safety on expressway.

  14. A study of carburetor/induction system icing in general aviation accidents

    NASA Technical Reports Server (NTRS)

    Obermayer, R. W.; Roe, W. T.

    1975-01-01

    An assessment of the frequency and severity of carburetor/induction icing in general-aviation accidents was performed. The available literature and accident data from the National Transportation Safety Board were collected. A computer analysis of the accident data was performed. Between 65 and 90 accidents each year involve carburetor/induction system icing as a probable cause/factor. Under conditions conducive to carburetor/induction icing, between 50 and 70 percent of engine malfunction/failure accidents (exclusive of those due to fuel exhaustion) are due to carburetor/induction system icing. Since the evidence of such icing may not remain long after an accident, it is probable that the frequency of occurrence of such accidents is underestimated; therefore, some extrapolation of the data was conducted. The problem of carburetor/induction system icing is particularly acute for pilots with less than 1000 hours of total flying time. The severity of such accidents is about the same as any accident resulting from a forced landing or precautionary landing. About 144 persons, on the average, are exposed to death and injury each year in accidents involving carburetor/induction icing as a probable cause/factor.

  15. [Principles of intervertebral disc assessment in private accident insurance].

    PubMed

    Steinmetz, M; Dittrich, V; Röser, K

    2015-09-01

    Due to the spread of intervertebral disc degeneration, insurance companies and experts are regularly confronted with related assessments of insured persons under their private accident insurance. These claims pose a particular challenge for experts, since, in addition to the clinical assessment of the facts, extensive knowledge of general accident insurance conditions, case law and current study findings is required. Each case can only be properly assessed through simultaneous consideration of both the medical and legal facts. These guidelines serve as the basis for experts and claims.managers with respect to the appropriate individual factual assessment of intervertebral disc degeneration in private accident insurance.

  16. Hub vortex instability within wind turbine wakes: Effects of wind turbulence, loading conditions, and blade aerodynamics

    NASA Astrophysics Data System (ADS)

    Ashton, Ryan; Viola, Francesco; Camarri, Simone; Gallaire, Francois; Iungo, Giacomo Valerio

    2016-11-01

    The near wake of wind turbines is characterized by the presence of the hub vortex, which is a coherent vorticity structure generated from the interaction between the root vortices and the boundary layer evolving over the turbine nacelle. By moving downstream, the hub vortex undergoes an instability with growth rate, azimuthal and axial wavenumbers determined by the characteristics of the incoming wind and turbine aerodynamics. Thus, a large variability of the hub vortex instability is expected for wind energy applications with consequent effects on wake downstream evolution, wake interactions within a wind farm, power production, and fatigue loads on turbines invested by wakes generated upstream. In order to predict characteristics of the hub vortex instability for different operating conditions, linear stability analysis is carried out by considering different statistics of the incoming wind turbulence, thrust coefficient, tip speed ratio, and blade lift distribution of a wind turbine. Axial and azimuthal wake velocity fields are modeled through Carton-McWilliams velocity profiles by mimicking the presence of the hub vortex, helicoidal tip vortices, and matching the wind turbine thrust coefficient predicted through the actuator disk model. The linear stability analysis shows that hub vortex instability is strongly affected by the wind turbine loading conditions, and specifically it is promoted by a larger thrust coefficient. A higher load of the wind turbines produces an enhanced axial velocity deficit and, in turn, higher shear in the radial direction of the streamwise velocity. The axial velocity shear within the turbine wake is also the main physical mechanism promoting the hub vortex instability when varying the lift distribution over the blade span for a specific loading condition. Cases with a larger velocity deficit in proximity of the wake center and less aerodynamic load towards the blade tip result to be more unstable. Moreover, wake swirl promotes hub

  17. An exploratory study of cognitive load in diagnosing patient conditions.

    PubMed

    Workman, Michael; Lesser, Michael F; Kim, Joonmin

    2007-06-01

    To determine whether the ways in which information is presented to physicians will improve their ability to respond in a timely and accurate manner to acute care needs. The forms of the presentation compared traditional textual, chart and graph representations with equivalent symbolic language representations. To test this objective, our investigation involved two studies of interpreting patient conditions using two forms of information representation. The first assessed the level of cognitive effort (the outcome variable is known as cognitive load), and the second assessed the time and accuracy outcome variables. Our investigation consisted of two studies, the first study involved 3rd and 4th year medical students, and the second study involved three board certified physicians who worked in an intensive care unit of a metropolitan hospital. The first study utilized an all-within-subject design with repeated measures, where pretests were utilized as control covariate for prior learning and individual differences. The second study utilized a random sampling of records analyzed by two physicians and qualitatively evaluated by board-certified intensivists. The first study indicated that the cognitive load to interpret the symbolic representation was less than those presented in the more traditional textual, chart and graphic form. The second study suggests that experienced physicians may react in a more timely fashion with at least the same accuracy when the symbolic language was used than with traditional charts and graphs. The ways in which information is presented to physicians may affect the quality of acute care, such as in intensive, critical and emergency care units. When information can be presented in symbolic form, it may be cognitively processed more efficiently than when it is presented in the usual textual and chart form, potentially lowering errors in diagnosis and increasing the responsiveness to patient conditions.

  18. Simulation of working conditions by maximum work load on firefighters.

    PubMed

    Lalić, Hrvoje; Bukmir, Leonardo; Ferhatović, Mensur

    2007-03-01

    The aim of this research is to find out whether the firefighter manpower is adequate to the requirements in the field under the most severe conditions. It also attempts to test whether firefighters' working ability corresponds to their age. To that purpose 220 Croatian firefighters from the Littoral Mountainous county, 99 professional firefighters from the city of Rijeka, 45 professional firefighters from its suburbs and 76 volunteer firefighters from the suburbs were submitted to load test, fitness test--stepping on the bench for three minutes, repetitive power test--sit-ups lasting 1 minute, and a leap-explosive power test. The fitness test was repeated carrying Drdäer's respiratory apparatus PSS 100 with compressed air, so respiratory values were compared before and after the burden of the respiratory apparatus. The results have shown that professional firefighters from the city have the mean increased body mass index (BMI) 26, and professionals from the suburbs BMI 27. In spite of the increased body mass they showed good fitness, spirometric values before and after the load showed neither restrictive nor obstructive ventilation difficulties, which indicates a good condition of cardio respiratory system and also adequate protective equipment. The initial hypothesis has been confirmed: with age, equipped with personnel does not necessarily mean operative equipment, because linear regressive analyses have shown a negative correlation coefficient in relation to repetitive and explosive power. Also, on the average somewhat younger volunteer firefighters are stronger in performing the repetitive power test (p < 0.05) compared to professional firefighters. Occupational medicine should suggest administrative health measures to improve the accelerated retirement plan and shorten the shifts so that all available firefighters could instantaneously be included in the field intervention.

  19. Deformation and Heat Transfer on Three Sides Protected Beams under Fire Accident

    NASA Astrophysics Data System (ADS)

    Imran, M.; Liew, M. S.; Garcia, E. M.; Nasif, M. S.; Yassin, A. Y. M.; Niazi, U. M.

    2018-04-01

    Fire accidents are common in oil and gas industry. The application of passive fire protection (PFP) is a costly solution. The PFP is applied only on critical structural members to optimise project cost. In some cases, beams cannot be protected from the top flange in order to accommodate for the placement of pipe supports and grating. It is important to understand the thermal and mechanical response of beam under such condition. This paper discusses the response of steel beam under ISO 834 fire protected, unprotected and three sides protected beams. The model validated against an experimental study. The experimental study has shown good agreement with FE model. The study revealed that the beams protected from three sides heat-up faster compare to fully protected beam showing different temperature gradient. However, the affects load carrying capacity are insignificant under ISO 834 fire.

  20. Evaluation Metrics Applied to Accident Tolerant Fuels

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

    Shannon M. Bragg-Sitton; Jon Carmack; Frank Goldner

    2014-10-01

    The safe, reliable, and economic operation of the nation’s nuclear power reactor fleet has always been a top priority for the United States’ nuclear industry. Continual improvement of technology, including advanced materials and nuclear fuels, remains central to the industry’s success. Decades of research combined with continual operation have produced steady advancements in technology and have yielded an extensive base of data, experience, and knowledge on light water reactor (LWR) fuel performance under both normal and accident conditions. One of the current missions of the U.S. Department of Energy’s (DOE) Office of Nuclear Energy (NE) is to develop nuclear fuelsmore » and claddings with enhanced accident tolerance for use in the current fleet of commercial LWRs or in reactor concepts with design certifications (GEN-III+). Accident tolerance became a focus within advanced LWR research upon direction from Congress following the 2011 Great East Japan Earthquake, resulting tsunami, and subsequent damage to the Fukushima Daiichi nuclear power plant complex. The overall goal of ATF development is to identify alternative fuel system technologies to further enhance the safety, competitiveness and economics of commercial nuclear power. Enhanced accident tolerant fuels would endure loss of active cooling in the reactor core for a considerably longer period of time than the current fuel system while maintaining or improving performance during normal operations. The U.S. DOE is supporting multiple teams to investigate a number of technologies that may improve fuel system response and behavior in accident conditions, with team leadership provided by DOE national laboratories, universities, and the nuclear industry. Concepts under consideration offer both evolutionary and revolutionary changes to the current nuclear fuel system. Mature concepts will be tested in the Advanced Test Reactor at Idaho National Laboratory beginning in Summer 2014 with additional concepts

  1. Causes of Coal Mine Accidents in the World and Turkey

    PubMed Central

    Küçük, Filiz Çağla Uyanusta; Ilgaz, Aslıhan

    2015-01-01

    Occupational accidents and occupational diseases are common in the mining sector in Turkey and throughout the world. The most common causes of accidents in coal mining are firedamp and dust explosions, landslips, mine fires, and technical failures related to transport and mechanization. An analysis of occupational accidents in the consideration of social and economic factors will let understand the real causes behind these accidents, which are said to happen inevitably due to technical deficiencies or failures. Irregular working conditions, based on profit maximization and cost minimization, are related to strategic operational preferences and public policies. Proving that accidents in mines, where occupational health and safety measures are not implemented and inspections are not done properly or at all, are caused by the fact that production is imposed to be carried out in the fastest, cheapest, and most profitable way will allow us to take steps to prevent further mine accidents. PMID:29404108

  2. Lateral Torsional Buckling of Anisotropic Laminated Composite Beams Subjected to Various Loading and Boundary Conditions

    NASA Astrophysics Data System (ADS)

    Ahmadi, Habiburrahman

    Thin-walled structures are major components in many engineering applications. When a thin-walled slender beam is subjected to lateral loads, causing moments, the beam may buckle by a combined lateral bending and twisting of cross-section, which is called lateral-torsional buckling. A generalized analytical approach for lateral-torsional buckling of anisotropic laminated, thin-walled, rectangular cross-section composite beams under various loading conditions (namely, pure bending and concentrated load) and boundary conditions (namely, simply supported and cantilever) was developed using the classical laminated plate theory (CLPT), with all considered assumptions, as a basis for the constitutive equations. Buckling of such type of members has not been addressed in the literature. Closed form buckling expressions were derived in terms of the lateral, torsional and coupling stiffness coefficients of the overall composite. These coefficients were obtained through dimensional reduction by static condensation of the 6x6 constitutive matrix mapped into an effective 2x2 coupled weak axis bending-twisting relationship. The stability of the beam under different geometric and material parameters, like length/height ratio, ply thickness, and ply orientation, was investigated. The analytical formulas were verified against finite element buckling solutions using ABAQUS for different lamination orientations showing excellent accuracy.

  3. Markov switching multinomial logit model: An application to accident-injury severities.

    PubMed

    Malyshkina, Nataliya V; Mannering, Fred L

    2009-07-01

    In this study, two-state Markov switching multinomial logit models are proposed for statistical modeling of accident-injury severities. These models assume Markov switching over time between two unobserved states of roadway safety as a means of accounting for potential unobserved heterogeneity. The states are distinct in the sense that in different states accident-severity outcomes are generated by separate multinomial logit processes. To demonstrate the applicability of the approach, two-state Markov switching multinomial logit models are estimated for severity outcomes of accidents occurring on Indiana roads over a four-year time period. Bayesian inference methods and Markov Chain Monte Carlo (MCMC) simulations are used for model estimation. The estimated Markov switching models result in a superior statistical fit relative to the standard (single-state) multinomial logit models for a number of roadway classes and accident types. It is found that the more frequent state of roadway safety is correlated with better weather conditions and that the less frequent state is correlated with adverse weather conditions.

  4. Preliminary calculations related to the accident at Three Mile Island

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

    Kirchner, W.L.; Stevenson, M.G.

    This report discusses preliminary studies of the Three Mile Island Unit 2 (TMI-2) accident based on available methods and data. The work reported includes: (1) a TRAC base case calculation out to 3 hours into the accident sequence; (2) TRAC parametric calculations, these are the same as the base case except for a single hypothetical change in the system conditions, such as assuming the high pressure injection (HPI) system operated as designed rather than as in the accident; (3) fuel rod cladding failure, cladding oxidation due to zirconium metal-steam reactions, hydrogen release due to cladding oxidation, cladding ballooning, cladding embrittlement,more » and subsequent cladding breakup estimates based on TRAC calculated cladding temperatures and system pressures. Some conclusions of this work are: the TRAC base case accident calculation agrees very well with known system conditions to nearly 3 hours into the accident; the parametric calculations indicate that, loss-of-core cooling was most influenced by the throttling of High-Pressure Injection (HPI) flows, given the accident initiating events and the pressurizer electromagnetic-operated valve (EMOV) failing to close as designed; failure of nearly all the rods and gaseous fission product gas release from the failed rods is predicted to have occurred at about 2 hours and 30 minutes; cladding oxidation (zirconium-steam reaction) up to 3 hours resulted in the production of approximately 40 kilograms of hydrogen.« less

  5. Effects of driver nationality and road characteristics on accident fault risk.

    PubMed

    Yannis, George; Golias, John; Papadimitriou, Eleonora

    2007-09-01

    This paper investigates the combined effect of driver nationality and several road characteristics (area type, at or not at junction, lighting conditions) on accident fault risk. Data from the national accident database of Greece are used to calculate accident relative fault risk rates under induced exposure assumptions. A log-linear analysis is then used to examine first- and higher-order effects within three or more variable groups. The examination of the second-order interaction among the accident fault risks of various driver nationalities at or not at junction was found to be significant. On the contrary, the respective combined effects of area type and lighting conditions were found to be non-significant. It was also shown that roadway features do not affect accident fault risk in a combined way. Results clearly indicate that foreign drivers in Greece are at increased risk. Moreover, foreign nationalities corresponding to permanent residents (i.e. Greeks and Albanians) appear to be at lower fault risk compared to foreign nationalities corresponding to tourists and visitors (e.g. EU Nationals). The effects of the various road characteristics do not modify these general trends.

  6. Analysis of accidents with organic material in health workers.

    PubMed

    Vieira, Mariana; Padilha, Maria Itayra; Pinheiro, Regina Dal Castel

    2011-01-01

    This retrospective and descriptive study with a quantitative design aimed to evaluate occupational accidents with exposure to biological material, as well as the profile of workers, based on reporting forms sent to the Regional Reference Center of Occupational Health in Florianópolis/SC. Data collection was carried out through a survey of 118 reporting forms in 2007. Data were analyzed electronically. The occurrence of accidents was predominantly among nursing technicians, women and the mean age was 34.5 years. 73% of accidents involved percutaneous exposure, 78% had blood and fluid with blood, 44.91% resulted from invasive procedures. It was concluded that strategies to prevent the occurrence of accidents with biological material should include joint activities between workers and service management and should be directed at improving work conditions and organization.

  7. Prediction accident triangle in maintenance of underground mine facilities using Poisson distribution analysis

    NASA Astrophysics Data System (ADS)

    Khuluqi, M. H.; Prapdito, R. R.; Sambodo, F. P.

    2018-04-01

    In Indonesia, mining is categorized as a hazardous industry. In recent years, a dramatic increase of mining equipment and technological complexities had resulted in higher maintenance expectations that accompanied by the changes in the working conditions, especially on safety. Ensuring safety during the process of conducting maintenance works in underground mine is important as an integral part of accident prevention programs. Accident triangle has provided a support to safety practitioner to draw a road map in preventing accidents. Poisson distribution is appropriate for the analysis of accidents at a specific site in a given time period. Based on the analysis of accident statistics in the underground mine maintenance of PT. Freeport Indonesia from 2011 through 2016, it is found that 12 minor accidents for 1 major accident and 66 equipment damages for 1 major accident as a new value of accident triangle. The result can be used for the future need for improving the accident prevention programs.

  8. Influence of tool shape on lattice rearrangement under loading conditions reproducing friction stir welding

    NASA Astrophysics Data System (ADS)

    Konovalenko, Ivan S.; Konovalenko, Igor S.

    2015-10-01

    Metal behavior under loading conditions that reproduce friction stir welding was studied on the atomic scale. Calculations were conducted based on molecular dynamics simulation with potentials calculated within the embedded atom method. The loading of the interface between two crystallites, whose structure corresponded to aluminum alloy 2024, was simulated by the motion of a cone-shaped tool along the interface with constant angular and translational velocities. The motion of the rotating tool causes fracture of the workpiece crystal structure with subsequent mixing of surface atoms of the interfacing crystallites. It is shown that the resistance force acting on the moving tool from the workpiece and the process of structural defect formation in the workpiece depend on the tool shape.

  9. Analysis of general aviation accidents during operations under instrument flight rules

    NASA Technical Reports Server (NTRS)

    Bennett, C. T.; Schwirzke, Martin; Harm, C.

    1990-01-01

    A report is presented to describe some of the errors that pilots make during flight under IFR. The data indicate that there is less risk during the approach and landing phase of IFR flights, as compared to VFR operations. Single-pilot IFR accident rates continue to be higher than two-pilot IFR incident rates, reflecting the high work load of IFR operations.

  10. National and regional analysis of road accidents in Spain.

    PubMed

    Tolón-Becerra, A; Lastra-Bravo, X; Flores-Parra, I

    2013-01-01

    In Spain, the absolute fatality figures decreased almost 50 percent between 1998 and 2009. Despite this great effort, road mortality is still of great concern to political authorities. Further progress requires efficient road safety policy based on an optimal set of measures and targets that consider the initial conditions and characteristics in each region. This study attempts to analyze road accidents in Spain and its provinces in time and space during 1998-2009. First, we analyzed daily, monthly, and nationwide (NUTS 0) development of road accidents, the correlation between logarithmic transformations of road accidents and territorial and socioeconomic variables, the causality by simple linear regression of road accidents and territorial and socioeconomic variables, and preliminary frequency by fast Fourier transform. Then we analyzed the annual trend in accidents in the Spanish provinces (NUTS 3) and found a correlation between the logarithmic transformations of the mortality rate, fatalities per fatal accident, and accidents resulting in injuries per inhabitant variables and population, population density, gross domestic product (GDP), length of road network, and area. Finally, causality was analyzed by simple linear regression. The most outstanding results were the negative correlation between mortality rate and population density in Spanish provinces, which has increased over time, and that road accidents in Spain have an approximate periodicity of 57 days. The fast Fourier transform analysis of road accident frequency in Spain was useful in identifying the periodic, harmonic components of accidents and casualties. The periodicity observed both for the period 1998-2009 and by year showed that the highest intensity in road accidents was bimonthly, despite the lower number of accidents and casualties in the spectra of amplitude and power and efforts to reduce the intensity and concentration during off-season travel (summer and December).

  11. Contributions of the stochastic shape wake model to predictions of aerodynamic loads and power under single wake conditions

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

    Doubrawa, P.; Barthelmie, R. J.; Wang, H.

    The contribution of wake meandering and shape asymmetry to load and power estimates is quantified by comparing aeroelastic simulations initialized with different inflow conditions: an axisymmetric base wake, an unsteady stochastic shape wake, and a large-eddy simulation with rotating actuator-line turbine representation. Time series of blade-root and tower base bending moments are analyzed. We find that meandering has a large contribution to the fluctuation of the loads. Moreover, considering the wake edge intermittence via the stochastic shape model improves the simulation of load and power fluctuations and of the fatigue damage equivalent loads. Furthermore, these results indicate that the stochasticmore » shape wake simulator is a valuable addition to simplified wake models when seeking to obtain higher-fidelity computationally inexpensive predictions of loads and power.« less

  12. Contributions of the stochastic shape wake model to predictions of aerodynamic loads and power under single wake conditions

    DOE PAGES

    Doubrawa, P.; Barthelmie, R. J.; Wang, H.; ...

    2016-10-03

    The contribution of wake meandering and shape asymmetry to load and power estimates is quantified by comparing aeroelastic simulations initialized with different inflow conditions: an axisymmetric base wake, an unsteady stochastic shape wake, and a large-eddy simulation with rotating actuator-line turbine representation. Time series of blade-root and tower base bending moments are analyzed. We find that meandering has a large contribution to the fluctuation of the loads. Moreover, considering the wake edge intermittence via the stochastic shape model improves the simulation of load and power fluctuations and of the fatigue damage equivalent loads. Furthermore, these results indicate that the stochasticmore » shape wake simulator is a valuable addition to simplified wake models when seeking to obtain higher-fidelity computationally inexpensive predictions of loads and power.« less

  13. TMI-2 - A Case Study for PWR Instrumentation Performance during a Severe Accident

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

    Joy L. Rempe; Darrell L. Knudson

    2013-03-01

    The accident at the Three Mile Island Unit 2 (TMI-2) reactor provided a unique opportunity to evaluate sensors exposed to severe accident conditions. Conditions associated with the release of coolant and the hydrogen burn that occurred during this accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. As part of a program initiated in 2012 by the Department of Energy Office of Nuclear Energy (DOE-NE), a review was completed to gain insights from prior TMI-2 sensor survivability and data qualification efforts. This new effort focussed upon a set of sensorsmore » that provided critical data to TMI-2 operators for assessing the condition of the plant and the effects of mitigating actions taken by these operators. In addition, the effort considered sensors providing data required for subsequent accident simulations. Over 100 references related to instrumentation performance and post-accident evaluations of TMI-2 sensors and measurements were reviewed. Insights gained from this review are summarized within this report. For each sensor, a description is provided with the measured data and conclusions related to the sensor’s survivability, and the basis for conclusions about its survivability. As noted within this document, several techniques were invoked in the TMI-2 post-accident evaluation program to assess sensor status, including comparisons with data from other sensors, analytical calculations, laboratory testing, and comparisons with sensors subjected to similar conditions in large-scale integral tests and with sensors that were similar in design but more easily removed from the TMI-2 plant for evaluations. Conclusions from this review provide important insights related to sensor survivability and enhancement options for improving sensor performance. In addition, this document provides recommendations related to the sensor survivability and data

  14. TMI-2 - A Case Study for PWR Instrumentation Performance during a Severe Accident

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

    Joy L. Rempe; Darrell L. Knudson

    2014-05-01

    The accident at the Three Mile Island Unit 2 (TMI-2) reactor provided a unique opportunity to evaluate sensors exposed to severe accident conditions. Conditions associated with the release of coolant and the hydrogen burn that occurred during this accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. As part of a program initiated in 2012 by the Department of Energy Office of Nuclear Energy (DOE-NE), a review was completed to gain insights from prior TMI-2 sensor survivability and data qualification efforts. This new effort focussed upon a set of sensorsmore » that provided critical data to TMI-2 operators for assessing the condition of the plant and the effects of mitigating actions taken by these operators. In addition, the effort considered sensors providing data required for subsequent accident simulations. Over 100 references related to instrumentation performance and post-accident evaluations of TMI-2 sensors and measurements were reviewed. Insights gained from this review are summarized within this report. For each sensor, a description is provided with the measured data and conclusions related to the sensor’s survivability, and the basis for conclusions about its survivability. As noted within this document, several techniques were invoked in the TMI-2 post-accident evaluation program to assess sensor status, including comparisons with data from other sensors, analytical calculations, laboratory testing, and comparisons with sensors subjected to similar conditions in large-scale integral tests and with sensors that were similar in design but more easily removed from the TMI-2 plant for evaluations. Conclusions from this review provide important insights related to sensor survivability and enhancement options for improving sensor performance. In addition, this document provides recommendations related to the sensor survivability and data

  15. Unreported medications used in incapacitating medical conditions found in fatal civil aviation accidents.

    DOT National Transportation Integrated Search

    1994-08-01

    One of the major concerns in aviation medicine is sudden incapacitation of the pilot resulting in a fatal accident. The Office of Aviation Medicine (OAM) for the Federal Aviation Administration (FAA) is charged with the medical certification of pilot...

  16. Transposition of Francis turbine cavitation compliance at partial load to different operating conditions

    NASA Astrophysics Data System (ADS)

    Gomes, J.; Favrel, A.; Landry, C.; Nicolet, C.; Avellan, F.

    2017-04-01

    Francis turbines operating in part load conditions experience a swirling flow at the runner outlet leading to the development of a precessing cavitation vortex rope in the draft tube. This cavitation vortex rope changes drastically the velocity of pressure waves traveling in the draft tube and may lead to resonance conditions in the hydraulic circuit. The wave speed being strongly related to the cavitation compliance, this research work presents a simple model to explain how it is affected by variations of operating conditions and proposes a method to transpose its values. Even though the focus of this paper is on transpositions within the same turbine scale, the methodology is also expected to be tested for the model to prototype transposition in the future. Comparisons between measurements and calculations are in good agreement.

  17. Study of Benefits of Passenger Protective Breathing Equipment from Analysis of Past Accidents

    DTIC Science & Technology

    1988-03-01

    Rodeos (Tenerife) El 27 De Marzo De 1977 2. ICAO Aircraft Accident Digest No. 23, No. 2 B-30 AIRCRAFT ACCIDENT SUMMARY Carrier - Continental Airways...than FPL. However, a I’)-second donning de -lay of PBE may have resulted in a net disbenefit. k~f ¶ ~ 17. Key Words 18. Distributiion Stotement...in C-133 Test Article 23 with Postcrash Fire Conditions 5 Accident Profiles for 3/5/67 Varig DC-8 24 6 Accident Profiles for 4/8/68 British Overseas

  18. Influence of upstream disturbance on the draft-tube flow of Francis turbine under part-load conditions

    NASA Astrophysics Data System (ADS)

    Chen, Ting; Zheng, Xianghao; Zhang, Yu-ning; Li, Shengcai

    2018-02-01

    Owing to the part-load operations for the enhancement of grid flexibility, the Francis turbine often suffers from severe low-frequency and large-amplitude hydraulic instability, which is mostly pertinent to the highly unsteady swirling vortex rope in the draft tube. The influence of disturbances in the upstream (e.g., large-scale vortex structures in the spiral casing) on the draft-tube vortex flow is not well understood yet. In the present paper, the influence of the upstream disturbances on the vortical flow in the draft tube is studied based on the vortex identification method and the analysis of several important parameters (e.g., the swirl number and the velocity profile). For a small guide vane opening (representing the part-load condition), the vortices triggered in the spiral casing propagate downstream and significantly affect the swirling vortex-rope precession in the draft tube, leading to the changes of the intensity and the processional frequency of the swirling vortex rope. When the guide vane opening approaches the optimum one (representing the full-load condition), the upstream disturbance becomes weaker and thus its influences on the downstream flow are very limited.

  19. FASTGRASS: A mechanistic model for the prediction of Xe, I, Cs, Te, Ba, and Sr release from nuclear fuel under normal and severe-accident conditions

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

    Rest, J.; Zawadzki, S.A.

    The primary physical/chemical models that form the basis of the FASTGRASS mechanistic computer model for calculating fission-product release from nuclear fuel are described. Calculated results are compared with test data and the major mechanisms affecting the transport of fission products during steady-state and accident conditions are identified.

  20. Working memory load modulates microsaccadic rate.

    PubMed

    Dalmaso, Mario; Castelli, Luigi; Scatturin, Pietro; Galfano, Giovanni

    2017-03-01

    Microsaccades are tiny eye movements that individuals perform unconsciously during fixation. Despite that the nature and the functions of microsaccades are still lively debated, recent evidence has shown an association between these micro eye movements and higher order cognitive processes. Here, in two experiments, we specifically focused on working memory and addressed whether differential memory load could be reflected in a modulation of microsaccade dynamics. In Experiment 1, participants memorized a numerical sequence composed of either two (low-load condition) or five digits (high-load condition), appearing at fixation. The results showed a reduction in the microsaccadic rate in the high-load compared to the low-load condition. In Experiment 2, five red or green digits were always presented at fixation. Participants either memorized the color (low-load condition) or the five digits (high-load condition). Hence, visual stimuli were exactly the same in both conditions. Consistent with Experiment 1, microsaccadic rate was lower in the high-load than in the low-load condition. Overall, these findings reveal that an engagement of working memory can have an impact on microsaccadic rate, consistent with the view that microsaccade generation is pervious to top-down processes.

  1. Geometric and Road Environmental Effects against Total Number of Traffic Accidents in Kendari

    NASA Astrophysics Data System (ADS)

    Kurdin, M. Akbar; Welendo, La; Annisa, Nur

    2017-05-01

    From the large number of traffic accidents that occurred, the carrying of Kendari as the biggest contributor to accidents in the Southeast. The number of accidents in Kendari row since 2011 was recorded at 18 accidents due to the influence of geometric road, in 2012 registered at 13 accident and in 2013 amounted to 6 accidents, with accident data because of the influence Geometric recorded for 3 consecutive years the biggest contributor to accidents because of the influence of geometric is Abeli districts. This study aimed to determine the road which common point of accident-prone (Black spot) in Kecamatan Abeli as accident-prone areas in Kendari, analyze the influence of geometric and road environment against accidents on roads in Kecamatan Abeli, provide alternative treatment based on the causes of accidents on the location of the accident-prone points (blackspot) to reduce the rate of traffic accidents. From the results of a study of 6 curve the accident-prone locations, that the curve I, II, and VI is the “Black Spot” influenced by the amount and condition of traffic accidents, while at the curve II, a traffic accident that occurred also be caused by unsafe geometric where the type of geometric should be changed from Spiral-Spiral type to Spiral-Circle-Spiral type. This indicates geometric effect on the number of accidents.

  2. Anthropotechnological analysis of industrial accidents in Brazil.

    PubMed Central

    Binder, M. C.; de Almeida, I. M.; Monteau, M.

    1999-01-01

    The Brazilian Ministry of Labour has been attempting to modify the norms used to analyse industrial accidents in the country. For this purpose, in 1994 it tried to make compulsory use of the causal tree approach to accident analysis, an approach developed in France during the 1970s, without having previously determined whether it is suitable for use under the industrial safety conditions that prevail in most Brazilian firms. In addition, opposition from Brazilian employers has blocked the proposed changes to the norms. The present study employed anthropotechnology to analyse experimental application of the causal tree method to work-related accidents in industrial firms in the region of Botucatu, São Paulo. Three work-related accidents were examined in three industrial firms representative of local, national and multinational companies. On the basis of the accidents analysed in this study, the rationale for the use of the causal tree method in Brazil can be summarized for each type of firm as follows: the method is redundant if there is a predominance of the type of risk whose elimination or neutralization requires adoption of conventional industrial safety measures (firm representative of local enterprises); the method is worth while if the company's specific technical risks have already largely been eliminated (firm representative of national enterprises); and the method is particularly appropriate if the firm has a good safety record and the causes of accidents are primarily related to industrial organization and management (multinational enterprise). PMID:10680249

  3. Alloy Selection for Accident Tolerant Fuel Cladding in Commercial Light Water Reactors

    NASA Astrophysics Data System (ADS)

    Rebak, Raul B.

    2015-12-01

    As a consequence of the March 2011 events at the Fukushima site, the U.S. congress asked the Department of Energy (DOE) to concentrate efforts on the development of nuclear fuels with enhanced accident tolerance. The new fuels had to maintain or improve the performance of current UO2-zirconium alloy rods during normal operation conditions and tolerate the loss of active cooling in the core for a considerably longer time period than the current system. DOE is funding cost-shared research to investigate the behavior of advanced steels both under normal operation conditions in high-temperature water [ e.g., 561 K (288 °C)] and under accident conditions for reaction with superheated steam. Current results show that, under accident conditions, the advanced ferritic steels (1) have orders of magnitude lower reactivity with steam, (2) would generate less hydrogen and heat than the current zirconium alloys, (3) are resistant to stress corrosion cracking under normal operation conditions, and (4) have low general corrosion in water at 561 K (288 °C).

  4. Predicting the conditions under which vibroacoustic resonances with external periodic loads occur in the primary coolant circuits of VVER-based NPPs

    NASA Astrophysics Data System (ADS)

    Proskuryakov, K. N.; Fedorov, A. I.; Zaporozhets, M. V.

    2015-08-01

    The accident at the Japanese Fukushima Daiichi nuclear power plant (NPP) caused by an earthquake showed the need of taking further efforts aimed at improving the design and engineering solutions for ensuring seismic resistance of NPPs with due regard to mutual influence of the dynamic processes occurring in the NPP building structures and process systems. Resonance interaction between the vibrations of NPP equipment and coolant pressure pulsations leads to an abnormal growth of dynamic stresses in structural materials, accelerated exhaustion of equipment service life, and increased number of sudden equipment failures. The article presents the results from a combined calculation-theoretical and experimental substantiation of mutual amplification of two kinds of external periodic loads caused by rotation of the reactor coolant pump (RCP) rotor and an earthquake. The data of vibration measurements at an NPP are presented, which confirm the predicted multiple amplification of vibrations in the steam generator and RCP at a certain combination of coolant thermal-hydraulic parameters. It is shown that the vibration frequencies of the main equipment may fall in the frequency band corresponding to the maximal values in the envelope response spectra constructed on the basis of floor accelerograms. The article presents the results from prediction of conditions under which vibroacoustic resonances with external periodic loads take place, which confirm the occurrence of additional earthquake-induced multiple growth of pressure pulsation intensity in the steam generator at the 8.3 Hz frequency and additional multiple growth of vibrations of the RCP and the steam generator cold header at the 16.6 Hz frequency. It is shown that at the elastic wave frequency equal to 8.3 Hz in the coolant, resonance occurs with the frequency of forced vibrations caused by the rotation of the RCP rotor. A conclusion is drawn about the possibility of exceeding the design level of equipment vibrations

  5. Avalanche risk in backcountry terrain based on usage frequency and accident data

    NASA Astrophysics Data System (ADS)

    Techel, F.; Zweifel, B.; Winkler, K.

    2014-08-01

    In Switzerland, the vast majority of avalanche accidents occurs during recreational activities. Risk analysis studies mostly rely on accident statistics without considering exposure (or the elements at risk), i.e. how many and where people are recreating. We compared the accident data (backcountry touring) with reports from two social media mountaineering networks - bergportal.ch and camptocamp.org. On these websites, users reported more than 15 000 backcountry tours during the five winters 2009/2010 to 2013/2014. We noted similar patterns in avalanche accident data and user data like demographics of recreationists, distribution of the day of the week (weekday vs. weekend) or weather conditions (fine vs. poor weather). However, we also found differences such as the avalanche danger conditions on days with activities and accidents, but also the geographic distribution. While backcountry activities are concentrated in proximity to the main population centres in the West and North of the Swiss Alps, a large proportion of the severe avalanche accidents occurred in the inner-alpine, more continental regions with frequently unfavorably snowpack structure. This suggests that even greater emphasis should be put on the type of avalanche problem in avalanche education and avalanche forecasting to increase the safety of backcountry recreationists.

  6. Micro-mechanical damage of trabecular bone-cement interface under selected loading conditions: a finite element study.

    PubMed

    Zhang, Qing-Hang; Tozzi, Gianluca; Tong, Jie

    2014-01-01

    In this study, two micro finite element models of trabecular bone-cement interface developed from high resolution computed tomography (CT) images were loaded under compression and validated using the in situ experimental data. The models were then used under tension and shear to examine the load transfer between the bone and cement and the micro damage development at the bone-cement interface. In addition, one models was further modified to investigate the effect of cement penetration on the bone-cement interfacial behaviour. The simulated results show that the load transfer at the bone-cement interface occurred mainly in the bone cement partially interdigitated region, while the fully interdigitated region seemed to contribute little to the mechanical response. Consequently, cement penetration beyond a certain value would seem to be ineffective in improving the mechanical strength of trabecular bone-cement interface. Under tension and shear loading conditions, more cement failures were found in denser bones, while the cement damage is generally low under compression.

  7. 14 CFR 27.473 - Ground loading conditions and assumptions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... through the center of gravity throughout the landing impact. This lift may not exceed two-thirds of the... rotorcraft must be designed for a limit load factor of not less than the limit inertia load factor...

  8. 14 CFR 27.473 - Ground loading conditions and assumptions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... through the center of gravity throughout the landing impact. This lift may not exceed two-thirds of the... rotorcraft must be designed for a limit load factor of not less than the limit inertia load factor...

  9. 14 CFR 27.473 - Ground loading conditions and assumptions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... through the center of gravity throughout the landing impact. This lift may not exceed two-thirds of the... rotorcraft must be designed for a limit load factor of not less than the limit inertia load factor...

  10. Economic development, mobility and traffic accidents in Algeria.

    PubMed

    Bougueroua, M; Carnis, L

    2016-07-01

    The aim of this contribution is to estimate the impact of road economic conditions and mobility on traffic accidents for the case of Algeria. Using the cointegration approach and vector error correction model (VECM), we will examine simultaneously short term and long-term impacts between the number of traffic accidents, fuel consumption and gross domestic product (GDP) per capital, over the period 1970-2013. The main results of the estimation show that the number of traffic accidents in Algeria is positively influenced by the GDP per capita in the short and long term. It implies that a higher economic development worsens the road safety situation. However, the new traffic rules adopted in 2009 have an impact on the forecast trend of traffic accidents, meaning efficient public policy could improve the situation. This result calls for a strong political commitment with effective countermeasures for avoiding the further deterioration of road safety record in Algeria. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. How propeller suction is the dominant factor for ship accidents at shallow water conditions

    NASA Astrophysics Data System (ADS)

    Acar, Dursun; Alpar, Bedri; Ozeren, Sinan

    2017-04-01

    The laminar flow comes to the fore with the disappearance of the several other directions in the internal displacements in the water current. Due to the dominant speed direction during the straightforward motion of the ship, the underwater hull is associated with the continuous flow of laminar currents. The open marine environment acts as a compressible liquid medium because of the presence of many variables about water volume overflow boundaries where the ship is associated. Layers of water rising over the sea surface due to ship's body and the propeller's water push provides loss of liquid lifting force for the ship. These situations change the well-known sea-floor morphology and reliable depth limits, and lead to probable accidents. If the ship block coefficient for the front side is 0.7 or higher, the "squat" will be more on the bow, because the associated factor "displacement volume" causes to the low-pressure environment due to large and rapid turbulence. Thus, the bow sinks further, which faced with liquid's weaker lift force. The vessels Gerardus Mercator, Queen Elizabeth and Costa Concordia had accidents because of unified reasons of squat, fast water mass displacement by hull push and propeller suction interaction. In the case of water mass displacement from the bow side away, that accident occurred in 2005 by the vessel Gerardus Mercator with excessive longitudinal trim angularity in the shallow water. The vessel Costa Concordia (2012), voluminous water displaced from the rear left side was an important factor because of the sharp manoeuvre of that the captain made before the accident. Observations before the accident indicate that full-speed sharp turn provided listed position for the ship from left (port side) in the direction of travel before colliding and then strike a rock on the sloping side of the seabed. The reason why the ship drifted to the left depends mainly the water discharge occurred at the left side of the hull during left-hand rudder

  12. Threats to Aircraft Structural Safety Including a Compendium of Selected Structural Accidents/Incidents

    DTIC Science & Technology

    2010-03-01

    stressed radius at the speed brake cut-out in the lower wing surface, the KC-135 (Appendix B.2) was fatigue tested to 55,000 cyclic test hours without...A20]. Post accident flight tests revealed that deployment of the speed brakes during landing role produced a horizontal load spectrum, which was

  13. Effects of friction layer characteristics on the tribological properties of Ni3Al solid-lubricating composites at different load conditions

    NASA Astrophysics Data System (ADS)

    Lu, Guanchen; Shi, Xiaoliang; Huang, Yuchun; Liu, Xiyao; Yang, Meijun

    2018-05-01

    This paper investigates the effects of friction layer characteristics of Ni3Al matrix self-lubricating composites (NMCs) on the tribological properties sliding against ceramic ball Si3N4 at dry friction process at the different load conditions. The characteristics of friction layer are performed in terms of hardness of wear scars, thickness and elemental distributions of friction layer. The results show that the microhardness of wear scars of NMCs increases with the increase of the sliding time and applied load, which results in friction coefficient reduced and wear rate decreased, indicating that the tribological performance of NMCs is obviously affected by microhardness of wear scar. However, under excessive applied load, the performance of friction layer of NMCs is deteriorated for the spalling of wear debris and deformation of contact surface. Therefore, selecting appropriate load conditions during the sliding contact, at the transition to the optimal properties of friction layer maybe occur. NMCs exhibits excellent tribological properties at 15N, which leads to the lowest friction coefficient (0.386) and wear rate (2.48 × 10‑5 mm3 N‑1 m‑1), as well as the smoothest surface of wear track compared with the other load conditions. Meanwhile, the elemental distributions analysis of cross-section of friction layer of NMCs shows that the frictional structures can be divided into three main layers. The thickness of the friction-affected layer varies with the changing of applied load. These results could provide a reference for preparing the solid-lubrication materials with better tribological properties.

  14. Best practices to reduce the accident rate hotel

    NASA Astrophysics Data System (ADS)

    García Revilla, M. R.; Kahale Carrillo, D. T.

    2014-10-01

    Examining the available databases and existing tourism organizations can conclude that appear studies on accidents and their relationship with other variables. But in our case we want to assess this relationship in the performance of the hotel in relation to lower the accident rate. The Industrial Safety studies analyzing this accident causes (why they happen), their sources (committed activities), their agents (participants work means), its type (how the events occur or develop), all in order to develop prevention. In our case, as accidents happen because people commit wrongful acts or because the equipment, tools, machinery or workplaces are not in proper conditions, the preventive point of view we analyze through the incidence of workplace accidents hotel subsector. The crash occurs because there is a risk, so that adequate control of it would avoid despite individual factors. Absenteeism or absence from work was taken into account first by Dubois in 1977, as he realized the time lost in the nineteenth century due to the long working hours, which included the holidays. Motivation and job satisfaction were the elements that have been most important in the phenomenon of social psychology.

  15. Typical pedestrian accident scenarios for the development of autonomous emergency braking test protocols.

    PubMed

    Lenard, James; Badea-Romero, Alexandro; Danton, Russell

    2014-12-01

    An increasing proportion of new vehicles are being fitted with autonomous emergency braking systems. It is difficult for consumers to judge the effectiveness of these safety systems for individual models unless their performance is evaluated through track testing under controlled conditions. This paper aimed to contribute to the development of relevant test conditions by describing typical circumstances of pedestrian accidents. Cluster analysis was applied to two large British databases and both highlighted an urban scenario in daylight and fine weather where a small pedestrian walks across the road, especially from the near kerb, in clear view of a driver who is travelling straight ahead. For each dataset a main test configuration was defined to represent the conditions of the most common accident scenario along with test variations to reflect the characteristics of less common accident scenarios. Some of the variations pertaining to less common accident circumstances or to a minority of casualties in these scenarios were proposed as optional or supplementary test elements for an outstanding performance rating. Many considerations are incorporated into the final design and implementation of an actual testing regime, such as cost and the state of development of technology; only the representation of accident data lay within the scope of this paper. It would be desirable to ascertain the wider representativeness of the results by analysing accident data from other countries in a similar manner. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. [Chernobyl nuclear power plant accident and Tokaimura criticality accident].

    PubMed

    Takada, Jun

    2012-03-01

    It is clear from inspection of historical incidents that the scale of disasters in a nuclear power plant accident is quite low level overwhelmingly compared with a nuclear explosion in nuclear war. Two cities of Hiroshima and Nagasaki were destroyed by nuclear blast with about 20 kt TNT equivalent and then approximately 100,000 people have died respectively. On the other hand, the number of acute death is 30 in the Chernobyl nuclear reactor accident. In this chapter, we review health hazards and doses in two historical nuclear incidents of Chernobyl and Tokaimura criticality accident and then understand the feature of the radiation accident in peaceful utilization of nuclear power.

  17. Influence of tool shape on lattice rearrangement under loading conditions reproducing friction stir welding

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

    Konovalenko, Ivan S., E-mail: ivkon@ispms.tsc.ru; Konovalenko, Igor S., E-mail: igkon@ispms.tsc.ru; National Research Tomsk Polytechnic University, Tomsk, 634050

    2015-10-27

    Metal behavior under loading conditions that reproduce friction stir welding was studied on the atomic scale. Calculations were conducted based on molecular dynamics simulation with potentials calculated within the embedded atom method. The loading of the interface between two crystallites, whose structure corresponded to aluminum alloy 2024, was simulated by the motion of a cone-shaped tool along the interface with constant angular and translational velocities. The motion of the rotating tool causes fracture of the workpiece crystal structure with subsequent mixing of surface atoms of the interfacing crystallites. It is shown that the resistance force acting on the moving toolmore » from the workpiece and the process of structural defect formation in the workpiece depend on the tool shape.« less

  18. Assessment of functional conditions of basketball and football players during the load by applying the model of integrated evaluation.

    PubMed

    Zumbakytė-Šermukšnienė, Renata; Kajėnienė, Alma; Vainoras, Alfonsas; Berškienė, Kristina; Augutienė, Viktorija

    2010-01-01

    We consider the human body as an adaptable, complex, and dynamic system capable of organizing itself, though there is none, the only one, factor inside the system capable of doing this job. Making use of the computerized ECG analysis system "Kaunas-load" with parallel registration of ECG carrying out body motor characteristics, ABP, or other processes characterizing hemodynamics enable one to reveal and evaluate the synergistic aspects of essential systems of the human body what particularly extends the possibilities of functional diagnostics. The aim of the study was to determine the features of alterations in the functional condition of basketball and football players and nonathletes during the bicycle ergometry test by applying the model of evaluation of the functional condition of the human body. The study population consisted of 266 healthy athletes and nonathletes. Groups of male basketball players, male football players, male nonathletes, female basketball players, and female nonathletes were studied. A computerized ECG analysis system "Kaunas-load" that is capable of both registering and analyzing the power developed by the subject and 12-lead ECG synchronically were used for evaluating the functional condition of the CVS. The subject did a computer-based bicycle ergometry test. The following ECG parameters at rest and throughout the load - HR, JT interval, and the deduced JT/RR ratio index that reflects the condition between regulatory and supplying systems - were evaluated. After measuring ABP, the pulse amplitude (S-D) was evaluated. The pulse blood pressure ratio amplitude (S-D)/S that depicts the connection between the periphery and regulatory systems was also evaluated. Speeds of changes in physiological parameters during physical load were evaluated too. Heart rate and JT/RR ratio of athletes at the rest and during load were lower, and JT interval of rest was longer and became shorter more slowly during load, compared to that of healthy nonathletes

  19. Guidelines for exposure assessment in health risk studies following a nuclear reactor accident.

    PubMed

    Bouville, André; Linet, Martha S; Hatch, Maureen; Mabuchi, Kiyohiko; Simon, Steven L

    2014-01-01

    Worldwide concerns regarding health effects after the Chernobyl and Fukushima nuclear power plant accidents indicate a clear need to identify short- and long-term health impacts that might result from accidents in the future. Fundamental to addressing this problem are reliable and accurate radiation dose estimates for the affected populations. The available guidance for activities following nuclear accidents is limited with regard to strategies for dose assessment in health risk studies. Here we propose a comprehensive systematic approach to estimating radiation doses for the evaluation of health risks resulting from a nuclear power plant accident, reflected in a set of seven guidelines. Four major nuclear reactor accidents have occurred during the history of nuclear power production. The circumstances leading to these accidents were varied, as were the magnitude of the releases of radioactive materials, the pathways by which persons were exposed, the data collected afterward, and the lifestyle factors and dietary consumption that played an important role in the associated radiation exposure of the affected populations. Accidents involving nuclear reactors may occur in the future under a variety of conditions. The guidelines we recommend here are intended to facilitate obtaining reliable dose estimations for a range of different exposure conditions. We recognize that full implementation of the proposed approach may not always be feasible because of other priorities during the nuclear accident emergency and because of limited resources in manpower and equipment. The proposed approach can serve as a basis to optimize the value of radiation dose reconstruction following a nuclear reactor accident.

  20. Deformation mechanism of CrN/nitriding coated steel in wear and nano-scratch experiments under heavy loading conditions

    NASA Astrophysics Data System (ADS)

    Wang, Yongguang; Chen, Yao; Zhao, Dong; Lu, Xiaolong; Liu, Weiwei; Qi, Fei; Chen, Yang

    2018-07-01

    CrN coatings are widely used to protect metals from wear in industrial engineering. However, fundamental deformation mechanism of these coatings under heavy loading conditions remains elusive. In this paper, multilayered hard coatings with a CrN matrix and a supporting layer were developed by means of the hybrid deposition process combined with PVD and ionicnitriding. The tribological behavior of coatings with and without ionicnitriding were investigated by a pin-on-disk arrangement under heavy loading conditions. In addition, the deformation mechanism of the multilayered hard coatings was studied by nano-scratch experiment with ramp load model, which has not been discussed previously. It was found that the deformation process of coatings could be divided into three regimes based on the evolution of frictional coefficient. The insertion of nitriding films leads to the further increase in frictional resistance owing to the elastic-plastic deformation. The results and analysis reveal some insights into the coating design for multilayered hard coatings with the consideration of deformation mechanisms.

  1. Assessment of thermal load on transported goats administered with ascorbic acid during the hot-dry conditions

    NASA Astrophysics Data System (ADS)

    Minka, N. S.; Ayo, J. O.

    2012-03-01

    The major factor in the induction of physiological stress during road transportation of livestock is the complex fluctuations of the thermal transport microenvironment, encountered when animals are transported across different ecological zones. Recommended guidelines on optimum "on-board" conditions in which goats should be transported are lacking, and there are no acceptable ranges and limits for the thermal loads to which goats may be subjected during long-distance road transportation in hot-dry conditions. Panting score (PS), rectal temperature (RT), heart rate (HR) and respiratory rate (RR) were employed as reliable stress indices to assess the effects of different thermal loads, measured as temperature humidity index (THI), encountered in the vehicle during 12 h of road transportation of 40 goats, and to suggest the administration of 100 mg/kg body weight of ascorbic acid (AA) as an ameliorating agent. The results obtained showed that the PS, RT, HR and RR rose above normal reference values with increase in the THI and journey duration. The rise in PS value, which is a visual indicator of the severity of thermal load, was the most pronounced. The results suggest that values of THI in the vehicle up to 94.6 constitute no risk, while at of 100 it presents a moderate risk and above 100 may result in severe stress. The relationships between the thermal load and the physiological variables were positive and significant ( P < 0.05). They reflect the degree of stress imposed by each THI value during the transportation, and may be used as recommended ranges and limit thermal load values in transported goats. The results demonstrated that administration of 100 mg/kg body weight of AA before road transportation mitigated the risk of adverse effects of high THI values and other stress factors due to road transportation in goats.

  2. Effect of boundary conditions and panel geometry on the response of laminated panels subjected to transverse pressure loads

    NASA Technical Reports Server (NTRS)

    Jegley, Dawn C.

    1993-01-01

    The behavior of thin laminated flat and curved panels subjected to transverse pressure and inplane loads is considered. The effects of panel geometry, boundary conditions and laminate stacking sequence on the response of panels subjected to transverse pressure loads up to 12.4 N/sq cm is presented. The response of thin laminated panels is evaluated analytically and selected results are compared with test data. A parametric study of the deformation and strain responses of panels with radius of curvature ranging from 20 to 305 cm is presented. The combination of inplane tensile and pressure loads is also considered.

  3. Accident analysis of heavy water cooled thorium breeder reactor

    NASA Astrophysics Data System (ADS)

    Yulianti, Yanti; Su'ud, Zaki; Takaki, Naoyuki

    2015-04-01

    power reactor has a peak value before reactor has new balance condition. The analysis showed that temperatures of fuel and claddings during accident are still below limitations which are in secure condition.

  4. Validation of the CALSPAN gross-motion-simulation code with actually occurring injury patterns in aircraft accidents.

    PubMed

    Ballo, J M; Dunne, M J; McMeekin, R R

    1978-01-01

    Digital simulation of aircraft-accident kinematics has heretofore been used almost exclusively as a design tool to explore structural load limits, precalculate decelerative forces at various cabin stations, and describe the effect of protective devices in the crash environment. In an effort to determine the value of digital computer simulation of fatal aircraft accidents, a fatality involving an ejection-system failure (out-of-envelope ejection) was modeled, and the injuries actually incurred were compared to those predicted; good agreement was found. The simulation of fatal aircraft accidents is advantageous because of a well-defined endpoint (death), lack of therapeutic intervention, and a static anatomic situation that can be minutely investigated. Such simulation techniques are a useful tool in the study of experimental trauma.

  5. 76 FR 10213 - Special Conditions: Embraer Model EMB-135BJ (Legacy 650) Airplanes, Limit Engine Torque Loads for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-24

    ... criteria for the more-severe events would no longer be a pure static torque-load condition, but would... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 25 [Docket No. NM449; Notice No. 25-420-SC] Special Conditions: Embraer Model EMB-135BJ (Legacy 650) Airplanes, Limit Engine...

  6. Sleep restriction and cognitive load affect performance on a simulated marksmanship task.

    PubMed

    Smith, Carl D; Cooper, Adam D; Merullo, Donna J; Cohen, Bruce S; Heaton, Kristin J; Claro, Pedro J; Smith, Tracey

    2017-11-24

    Sleep restriction degrades cognitive and motor performance, which can adversely impact job performance and increase the risk of accidents. Military personnel are prone to operating under sleep restriction, and previous work suggests that military marksmanship may be negatively affected under such conditions. Results of these studies, however, are mixed and have often incorporated additional stressors (e.g. energy restriction) beyond sleep restriction. Moreover, few studies have investigated how the degree of difficulty of a marksmanship task impacts performance following sleep restriction. The purpose of the current experiment was to study the effects of sleep restriction on marksmanship while minimizing the potential influence of other forms of stress. A friend-foe discrimination challenge with greater or lesser degrees of complexity (high versus low load) was used as the primary marksmanship task. Active duty Soldiers were recruited, and allowed 2 h of sleep every 24 h over a 72-h testing period. Marksmanship tasks, cognitive assessment metrics and the NASA-Task Load Index were administered daily. Results indicated that reaction times to shoot foe targets and signal friendly targets slowed over time. In addition, the ability to correctly discriminate between friend and foe targets significantly decreased in the high-cognitive-load condition over time despite shot accuracy remaining stable. The NASA-Task Load Index revealed that, although marksmanship performance degraded, participants believed their performance did not change over time. These results further characterize the consequences of sleep restriction on marksmanship performance and the perception of performance, and reinforce the importance of adequate sleep among service members when feasible. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  7. World commercial aircraft accidents

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

    Kimura, C.Y.

    1993-01-01

    This report is a compilation of all accidents world-wide involving aircraft in commercial service which resulted in the loss of the airframe or one or more fatality, or both. This information has been gathered in order to present a complete inventory of commercial aircraft accidents. Events involving military action, sabotage, terrorist bombings, hijackings, suicides, and industrial ground accidents are included within this list. Included are: accidents involving world commercial jet aircraft, world commercial turboprop aircraft, world commercial pistonprop aircraft with four or more engines and world commercial pistonprop aircraft with two or three engines from 1946 to 1992. Each accidentmore » is presented with information in the following categories: date of the accident, airline and its flight numbers, type of flight, type of aircraft, aircraft registration number, construction number/manufacturers serial number, aircraft damage, accident flight phase, accident location, number of fatalities, number of occupants, cause, remarks, or description (brief) of the accident, and finally references used. The sixth chapter presents a summary of the world commercial aircraft accidents by major aircraft class (e.g. jet, turboprop, and pistonprop) and by flight phase. The seventh chapter presents several special studies including a list of world commercial aircraft accidents for all aircraft types with 100 or more fatalities in order of decreasing number of fatalities, a list of collision accidents involving commercial aircrafts, and a list of world commercial aircraft accidents for all aircraft types involving military action, sabotage, terrorist bombings, and hijackings.« less

  8. High-speed propeller noise predictions - Effects of boundary conditions used in blade loading calculations

    NASA Technical Reports Server (NTRS)

    Nallasamy, M.; Clark, B. J.; Groeneweg, J. F.

    1987-01-01

    The acoustics of an advanced single rotation SR-3 propeller at cruise conditions are studied employing a time-domain approach. The study evaluates the acoustic significance of the differences in blade pressures computed using nonreflecting rather than hard wall boundary conditions in the three-dimensional Euler code solution. The directivities of the harmonics of the blade passing frequency tone and the effects of chordwise loading on tone directivity are examined. The results show that the maximum difference in the computed sound pressure levels due to the use of blade pressure distributions obtained with the nonreflecting rather than the hard wall boundary conditions is about 1.5 dB. The blade passing frequency tone directivity obtained in the present study shows good agreement with jetstar flight data.

  9. High-speed propeller noise predictions: Effects of boundary conditions used in blade loading calculations

    NASA Technical Reports Server (NTRS)

    Nallasamy, M.; Clark, B. J.; Groeneweg, J. F.

    1987-01-01

    The acoustics of an advanced single rotation SR-3 propeller at cruise conditions are studied employing a time-domain approach. The study evaluates the acoustic significance of the differences in blade pressures computed using nonreflecting rather than hard wall boundary conditions in the three-dimensional Euler code solution. The directivities of the harmonics of the blade passing frequency tone and the effects of chordwise loading on tone directivity are examined. The results show that the maximum difference in the computed sound pressure levels due to the use of blade pressure distributions obtained with the nonreflecting rather than the hard wall boundary conditions is about 1.5 dB. The blade passing frequency tone directivity obtained in the present study shows good agreement with jetstar flight data.

  10. A Human Factors Analysis and Classification System (HFACS) Examination of Commercial Vessel Accidents

    DTIC Science & Technology

    2012-09-01

    Naval Operations before the Congress on FY2013 Department of Navy posture. Heinrich , H . W. (1941). Industrial accident prevention : A scientific...Theory The core of the Domino Theory, developed by Herbert W. Heinrich who studied industrial safety in the early 1900s, is that accidents are a result...chain of events resulting in an accident . Heinrich likened the dominos to unsafe conditions or unsafe acts, where their subsequent removal prevents a

  11. Biofiltration of xylene using wood charcoal as the biofilter media under transient and high loading conditions.

    PubMed

    Singh, Kiran; Giri, B S; Sahi, Amrita; Geed, S R; Kureel, M K; Singh, Sanjay; Dubey, S K; Rai, B N; Kumar, Surendra; Upadhyay, S N; Singh, R S

    2017-10-01

    The main objective of this study was to evaluate the performance of wood charcoal as biofilter media under transient and high loading condition. Biofiltration of xylene was investigated for 150days in a laboratory scale unit packed with wood charcoal and inoculated with mixed microbial culture at the xylene loading rates ranged from 12 to 553gm -3 h -1 . The kinetic analysis of the xylene revealed absence of substrate inhibition and possibility of achieving higher elimination under optimum condition. The pH, temperature, pressure drop and CO 2 production rate were regularly monitored during the experiments. Throughout experimental period, the removal efficiency (RE) was found to be in the range of 65-98.7% and the maximum elimination capacity (EC) was 405.7gm -3 h -1 . Molecular characterization results show Bacillus sp. as dominating microbial group in the biofilm. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. [Multicenter paragliding accident study 1990].

    PubMed

    Lautenschlager, S; Karli, U; Matter, P

    1992-01-01

    During the period from 1.1.90 until 31.12.90, 86 injuries associated with paragliding were analyzed in a prospective study in 12 different Swiss hospitals with reference to causes, patterns, and frequencies. The injuries showed a mean score of over 2 and were classified as severe. Most frequent spine injuries (36%) and lesions of the lower extremity (35%) with a high risk of the ankles were diagnosed. One accident was fatal. 60% of the accidents happened during landing, 26% during launching and 14% during flight. Half of the pilots were affected during their primary training course. Most accidents were caused by inflight error of judgement--especially incorrect estimation of wind conditions--and further the choice of unfavourable landing sites. In contrast to previous injury-reports, only one equipment failure could be noted, but often the equipment was not corresponding with the experience and the weight of the pilot. To reduce the frequency of paragliding-injuries an accurate choice of equipment and an increased attention to environmental factors is mandatory. Furthermore an education-program regarding the attitude and intelligence of the pilot should be included in training courses.

  13. Diluting the burden of load: perceptual load effects are simply dilution effects.

    PubMed

    Tsal, Yehoshua; Benoni, Hanna

    2010-12-01

    The substantial distractor interference obtained for small displays when the target appears alone is reduced in large displays when the target is embedded among neutral letters. This finding has been interpreted as reflecting low-load and high-load processing, respectively, thereby supporting the theory of perceptual load (Lavie & Tsal, 1994). However, a possible alternative interpretation of this effect is that the distractor is similarly processed in both displays, yet its interference in the large ones is diluted by the presence of the neutral letters. We separated the effects of load and dilution by introducing dilution displays. They contained as many letters as the high-load displays but were clearly distinguished from the target, thus allowing for a low-load processing mode. Distractor interference obtained under both the low-load and high-load conditions disappeared under the dilution condition. Hence, the display size effect traditionally misattributed to perceptual load is fully accounted for by dilution. Furthermore, when dilution is controlled for, it is high load not low load producing greater interference.

  14. An Application of CICCT Accident Categories to Aviation Accidents in 1988-2004

    NASA Technical Reports Server (NTRS)

    Evans, Joni K.

    2007-01-01

    Interventions or technologies developed to improve aviation safety often focus on specific causes or accident categories. Evaluation of the potential effectiveness of those interventions is dependent upon mapping the historical aviation accidents into those same accident categories. To that end, the United States civil aviation accidents occurring between 1988 and 2004 (n=26,117) were assigned accident categories based upon the taxonomy developed by the CAST/ICAO Common Taxonomy Team (CICTT). Results are presented separately for four main categories of flight rules: Part 121 (large commercial air carriers), Scheduled Part 135 (commuter airlines), Non-Scheduled Part 135 (on-demand air taxi) and Part 91 (general aviation). Injuries and aircraft damage are summarized by year and by accident category.

  15. Psychological Distress and Post-Traumatic Symptoms Following Occupational Accidents

    PubMed Central

    Ghisi, Marta; Novara, Caterina; Buodo, Giulia; Kimble, Matthew O.; Scozzari, Simona; Di Natale, Arianna; Sanavio, Ezio; Palomba, Daniela

    2013-01-01

    Depression and post-traumatic stress disorder frequently occur as a consequence of occupational accidents. To date, research has been primarily focused on high-risk workers, such as police officers or firefighters, and has rarely considered individuals whose occupational environment involves the risk of severe, but not necessarily life-threatening, injury. Therefore, the present study was aimed at assessing the psychological consequences of accidents occurring in several occupational settings (e.g., construction and industry). Thirty-eight victims of occupational accidents (injured workers) and 38 gender-, age-, and years of education-matched workers who never experienced a work accident (control group) were recruited. All participants underwent a semi-structured interview administered by a trained psychologist, and then were requested to fill in the questionnaires. Injured workers reported more severe anxious, post-traumatic and depressive symptoms, and poorer coping skills, as compared to controls. In the injured group low levels of resilience predicted post-traumatic symptomatology, whereas the degree of physical injury and the length of time since the accident did not play a predictive role. The results suggest that occupational accidents may result in a disabling psychopathological condition, and that a brief psychological evaluation should be included in the assessment of seriously injured workers. PMID:25379258

  16. Factors Associated with Road Accidents among Brazilian Motorcycle Couriers

    PubMed Central

    da Silva, Daniela Wosiack; de Andrade, Selma Maffei; Soares, Dorotéia Fátima Pelissari de Paula; Mathias, Thais Aidar de Freitas; Matsuo, Tiemi; de Souza, Regina Kazue Tanno

    2012-01-01

    The objective of the study was to identify factors associated with reports of road accidents, among motorcycle couriers in two medium-sized municipalities in southern Brazil. A self-administered questionnaire was answered by motorcycle couriers that had worked for at least 12 months in this profession. The outcomes analyzed were reports on accidents and serious accidents over the 12 months prior to the survey. Bivariate and multivariate analyses by means of logistic regression were carried out to investigate factors that were independently associated with the outcomes. Seven hundred and fifty motorcycle couriers, of mean age 29.5 years (standard deviation = 8.1 ), were included in the study. Young age (18 to 24 years compared to ≥25 years, odds ratio [OR] = 1.77) speeding (OR = 1.48), and use of cell phones while driving (OR = 1.43) were factors independently associated with reports of accidents. For serious accidents, there was an association with alternation of work shifts (OR = 1.91) and speeding (OR = 1.67). The characteristics associated with accidents—personal (young age), behavioral (use of cell phones while driving and speeding), and professional (speeding and alternation of work shifts)—reveal the need to adopt wide-ranging strategies to reduce these accidents, including better work conditions for these motorcyclists. PMID:22629158

  17. Experimental and numerical investigation into the influence of loading conditions in biomechanical testing of locking plate fracture fixation devices

    PubMed Central

    MacLeod, A.; Simpson, A. H. R. W.

    2018-01-01

    Objectives Secondary fracture healing is strongly influenced by the stiffness of the bone-fixator system. Biomechanical tests are extensively used to investigate stiffness and strength of fixation devices. The stiffness values reported in the literature for locked plating, however, vary by three orders of magnitude. The aim of this study was to examine the influence that the method of restraint and load application has on the stiffness produced, the strain distribution within the bone, and the stresses in the implant for locking plate constructs. Methods Synthetic composite bones were used to evaluate experimentally the influence of four different methods of loading and restraining specimens, all used in recent previous studies. Two plate types and three screw arrangements were also evaluated for each loading scenario. Computational models were also developed and validated using the experimental tests. Results The method of loading was found to affect the gap stiffness strongly (by up to six times) but also the magnitude of the plate stress and the location and magnitude of strains at the bone-screw interface. Conclusions This study demonstrates that the method of loading is responsible for much of the difference in reported stiffness values in the literature. It also shows that previous contradictory findings, such as the influence of working length and very large differences in failure loads, can be readily explained by the choice of loading condition. Cite this article: A. MacLeod, A. H. R. W. Simpson, P. Pankaj. Experimental and numerical investigation into the influence of loading conditions in biomechanical testing of locking plate fracture fixation devices. Bone Joint Res 2018;7:111–120. DOI: 10.1302/2046-3758.71.BJR-2017-0074.R2. PMID:29363522

  18. The PSI Artist Project: Aerosol Retention and Accident Management Issues Following a Steam Generator Tube Rupture

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

    Guntay, Salih; Dehbi, Abdel; Suckow, Detlef

    2002-07-01

    Steam generator tube rupture (SGTR) incidents, such as those, which occurred in various operating pressurized, water reactors in the past, are serious operational concerns and remain among the most risk-dominant events. Although considerable efforts have been spent to understand tube degradation processes, develop improved modes of operation, and take preventative and corrective measures, SGTR incidents cannot be completely ruled out. Under certain conditions, high releases of radionuclides to the environment are possible during design basis accidents (DBA) and severe accidents. The severe accident codes' models for aerosol retention in the secondary side of a steam generator (SG) have not beenmore » assessed against any experimental data, which means that the uncertainties in the source term following an un-isolated SGTR concurrent with a severe accident are not currently quantified. The accident management (AM) procedures aim at avoiding or minimizing the release of fission products from the SG. The enhanced retention of activity within the SG defines the effectiveness of the accident management actions for the specific hardware characteristics and accident conditions of concern. A sound database on aerosol retention due to natural processes in the SG is not available, nor is an assessment of the effect of management actions on these processes. Hence, the effectiveness of the AM in SGTR events is not presently known. To help reduce uncertainties relating to SGTR issues, an experimental project, ARTIST (Aerosol Trapping In a Steam generator), has been initiated at the Paul Scherrer Institut to address aerosol and droplet retention in the various parts of the SG. The test section is comprised of a scaled-down tube bundle, a full-size separator and a full-size dryer unit. The project will study phenomena at the separate effect and integral levels and address AM issues in seven distinct phases: Aerosol retention in 1) the broken tube under dry secondary side

  19. Coupling continuum dislocation transport with crystal plasticity for application to shock loading conditions

    DOE PAGES

    Luscher, Darby Jon; Mayeur, Jason Rhea; Mourad, Hashem Mohamed; ...

    2015-08-05

    Here, we have developed a multi-physics modeling approach that couples continuum dislocation transport, nonlinear thermoelasticity, crystal plasticity, and consistent internal stress and deformation fields to simulate the single-crystal response of materials under extreme dynamic conditions. Dislocation transport is modeled by enforcing dislocation conservation at a slip-system level through the solution of advection-diffusion equations. Nonlinear thermoelasticity provides a thermodynamically consistent equation of state to relate stress (including pressure), temperature, energy densities, and dissipation. Crystal plasticity is coupled to dislocation transport via Orowan's expression where the constitutive description makes use of recent advances in dislocation velocity theories applicable under extreme loading conditions.more » The configuration of geometrically necessary dislocation density gives rise to an internal stress field that can either inhibit or accentuate the flow of dislocations. An internal strain field associated with the internal stress field contributes to the kinematic decomposition of the overall deformation. The paper describes each theoretical component of the framework, key aspects of the constitutive theory, and some details of a one-dimensional implementation. Results from single-crystal copper plate impact simulations are discussed in order to highlight the role of dislocation transport and pile-up in shock loading regimes. The main conclusions of the paper reinforce the utility of the modeling approach to shock problems.« less

  20. 14 CFR 23.485 - Side load conditions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... positions. (b) The limit vertical load factor must be 1.33, with the vertical ground reaction divided... reaction divided between the main wheels so that— (1) 0.5 (W) is acting inboard on one side; and (2) 0.33...

  1. Assessing accident phobia in mild traumatic brain injury: The Accident Fear Questionnaire.

    PubMed

    Sutherland, Jessica; Middleton, Jason; Ornstein, Tisha J; Lawson, Kerry; Vickers, Kristin

    2016-08-01

    Despite a documented prevalence of accident phobia in almost 40% of motor vehicle accident (MVA) survivors, the onset of accident phobia after traumatic brain injury (TBI) remains poorly understood. There is currently a body of knowledge about posttraumatic stress disorder (PTSD) in patients with TBI, but less is known about accident phobia following TBI, particularly in cases of mild TBI (mTBI). Accident phobia can impede safe return to driving or motor vehicle travel, inhibiting return to daily functioning. In addition, pain complaints have been found to correlate positively with postinjury anxiety disorders. The present study sought to determine the reliability and validity of the Accident Fear Questionnaire (AFQ), a measure used to assess accident phobia, in 72 patients with mTBI using secondary data analysis and the subsequent development of accident phobia postinjury. Furthermore, we sought to examine the impact of pain, anxiety, and depression complaints on the AFQ. Results reveal convergent validity and reliability in mTBI populations. Additionally, pain, anxiety, and depression measures were significantly correlated with scores on the AFQ. Psychometrically, the phobia avoidance subscale of the AFQ is a reliable measure for use with mTBI populations, although some limitations were found. In particular, the accident profile (AP) subscale was not found to be reliable or valid and could be eliminated from the AFQ. Collectively, the present study contributes to the small body of published literature evaluating accident phobia in patients with mTBI and the impact of pain on the development of postinjury anxiety disorders. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  2. 14 CFR 29.473 - Ground loading conditions and assumptions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... through the center of gravity throughout the landing impact. This lift may not exceed two-thirds of the... rotorcraft must be designed for a limit load factor of not less than the limit inertia load factor... factor of safety prescribed in § 29.303 need not be used. [Amdt. 29-3, 33 FR 966, Jan. 26, 1968] ...

  3. 14 CFR 29.473 - Ground loading conditions and assumptions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... through the center of gravity throughout the landing impact. This lift may not exceed two-thirds of the... rotorcraft must be designed for a limit load factor of not less than the limit inertia load factor... factor of safety prescribed in § 29.303 need not be used. [Amdt. 29-3, 33 FR 966, Jan. 26, 1968] ...

  4. 14 CFR 29.473 - Ground loading conditions and assumptions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... through the center of gravity throughout the landing impact. This lift may not exceed two-thirds of the... rotorcraft must be designed for a limit load factor of not less than the limit inertia load factor... factor of safety prescribed in § 29.303 need not be used. [Amdt. 29-3, 33 FR 966, Jan. 26, 1968] ...

  5. Economic situation and occupational accidents in Poland: 2002-2014 panel data regional study.

    PubMed

    Łyszczarz, Błażej; Nojszewska, Ewelina

    2018-01-07

    Occupational accidents constitute a substantial health and economic burden for societies around the world and a variety of factors determine the frequency of accidents at work. The aim of this paper is to investigate the relationship between the economic situation and the rate of occupational accidents in Poland. The analysis comprised data for 66 Polish sub-regions taken from the Central Statistical Office's Local Data Bank. The regression analysis with panel data for period 2002-2014 was applied to identify the relationships involved. Four measures of accidents were used: the rates of total occupational accidents, accidents among men and women separately as well as days of incapacity to work due to accidents at work per employee. Four alternative measures assessed the economic situation: gross domestic product (GDP) per capita, average remuneration, the unemployment rate and number of dwelling permits. The confounding variables included were: employment in hazardous conditions and the size of enterprises. The results of the regression estimates show that the number of occupational accidents in Poland exhibits procyclical behavior, which means that more accidents are observed during the times of economic expansion. Stronger relationships were observed in the equations explaining men's accident rates as well as total rates. A weaker and not always statistically significant impact of economic situation was identified for women's accident rates and days of incapacity to work. The results have important implications for occupational health and safety actions. In the periods of higher work intensity employers should focus on appropriate training and supervision of inexperienced workers as well as on ensuring enough time for already experienced employees to recuperate. In terms of public health actions, policy makers should focus on scrutinizing working conditions, educating employers and counteracting possible discrimination of injured employees. Int J Occup Med

  6. Economic and cultural correlates of road-traffic accident fatality rates in OECD countries.

    PubMed

    Gaygisiz, Esma

    2009-10-01

    The relationships between economic conditions, cultural characteristics, personality dimensions, intelligence scores, and road-traffic accident mortality rates were investigated in 30 member and five accession countries of the Organisation for Economic Co-operation and Development (OECD). Economic indicators included the Gross Domestic Product (GDP) per capita, the unemployment rate, and the Gini index. Cultural variables included five Hofstede's cultural dimensions, seven Schwartz cultural value dimensions, NEO-PI-R scales, and the intelligence quotient (IQ). The results showed positive associations between favorable economic conditions (high income per capita, high employment rate, and low income inequality) and high traffic safety. Countries with higher road-traffic accident fatality rates were characterized by higher power distance and uncertainty avoidance as well as embeddedness and emphasis on social hierarchy. Countries with lower road-traffic accident fatality rates were more individualistic, egalitarian, and emphasized autonomy of individuals. Conscientiousness (from NEO-PI-R) and IQ correlated negatively with road-traffic accident fatalities.

  7. Preventing accidents

    DOT National Transportation Integrated Search

    2005-08-01

    As the most effective strategy for improving safety is to prevent accidents from occurring at all, the Volpe Center applies a broad range of research techniques and capabilities to determine causes and consequences of accidents and to identify, asses...

  8. Overview of the U.S. DOE Accident Tolerant Fuel Development Program

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

    Jon Carmack; Frank Goldner; Shannon M. Bragg-Sitton

    2013-09-01

    The United States Fuel Cycle Research and Development Advanced Fuels Campaign has been given the responsibility to conduct research and development on enhanced accident tolerant fuels with the goal of performing a lead test assembly or lead test rod irradiation in a commercial reactor by 2022. The Advanced Fuels Campaign has defined fuels with enhanced accident tolerance as those that, in comparison with the standard UO2-Zircaloy system currently used by the nuclear industry, can tolerate loss of active cooling in the reactor core for a considerably longer time period (depending on the LWR system and accident scenario) while maintaining ormore » improving the fuel performance during normal operations and operational transients, as well as design-basis and beyond design-basis events. This paper provides an overview of the FCRD Accident Tolerant Fuel program. The ATF attributes will be presented and discussed. Attributes identified as potentially important to enhance accident tolerance include reduced hydrogen generation (resulting from cladding oxidation), enhanced fission product retention under severe accident conditions, reduced cladding reaction with high-temperature steam, and improved fuel-cladding interaction for enhanced performance under extreme conditions. To demonstrate the enhanced accident tolerance of candidate fuel designs, metrics must be developed and evaluated using a combination of design features for a given LWR design, potential improvements to that design, and the design of an advanced fuel/cladding system. The aforementioned attributes provide qualitative guidance for parameters that will be considered for fuels with enhanced accident tolerance. It may be unnecessary to improve in all attributes and it is likely that some attributes or combination of attributes provide meaningful gains in accident tolerance, while others may provide only marginal benefits. Thus, an initial step in program implementation will be the development of

  9. Influence of the cage on friction torque in low loaded thrust ball bearing operating in dry conditions

    NASA Astrophysics Data System (ADS)

    Olaru, D.; Balan, M. R.; Tufescu, A.

    2016-08-01

    The authors investigated analytically and experimentally the friction torque in a modified thrust ball bearing operating at very low axial load in dry conditions by using only three balls and a cage. The experiments were conducted by using spin-down methodology. The results evidenced the influence of the sliding friction between the cage and the balls on the total friction torque. It was concluded that at very low loads the friction between cage and balls in a thrust ball bearing has an important contribution on total friction torque.

  10. 14 CFR 23.485 - Side load conditions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... reaction divided between the main wheels so that— (1) 0.5 (W) is acting inboard on one side; and (2) 0.33... section are assumed to be applied at the ground contact point and the drag loads may be assumed to be zero...

  11. [Influence of individual characteristics and working conditions in the level of injury accident at work by registered in Andalusia, Spain, in 2003].

    PubMed

    Muñoz, Julia Bolívar; Codina, Antonio Daponte; Cruz, Laura López; Rodríguez, Inmaculada Mateo

    2009-01-01

    The study of the severity of occupational injuries is very important for the establishment of prevention plans. The aim of this paper is to analyze the distribution of occupational injuries by a) individual factors b) work place characteristics and c) working conditions and to analyze the severity of occupational injuries by this characteristics in men and women in Andalusia. Injury data came from the accident registry of the Ministry of Labor and social issues in 2003. Dependent variable: the severity of the injury: slight, serious, very serious and fatal; the independent variables: the characteristics of the worker, company data, and the accident itself. Bivariate and multivariate analysis were done to estimate the probability of serious, very serious and fatal injury, related to other variables, through odds ratio (OR), and using a 95% confidence interval (CI 95%). The 82.4% of the records were men and 17.6% were women, of whom the 78,1% are unskilled manual workers, compared to 44.9% of men. The men belonging to class I have a higher probability of more severe lesions (OR = 1.67, 95% CI = 1.17-2.38). The severity of the injury is associated with sex, age and type of injury. In men it is also related with the professional situation, the place where the accident happened, an unusual job, the size and the characteristics of the company and the social class, and in women with the sector.

  12. 78 FR 67323 - Special Conditions: Airbus, Model A350-900 Series Airplane; Transient Engine Failure Loads

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-12

    ... loads resulting from: a. the loss of any fan, compressor, or turbine blade; and separately b. where... DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 25 [Docket No. FAA-2013-0897; Notice No. 25-13-29-SC] Special Conditions: Airbus, Model A350-900 Series Airplane; Transient...

  13. rf conditioning and breakdown analysis of a traveling wave linac with collinear load cells

    NASA Astrophysics Data System (ADS)

    Chen, Qushan; Hu, Tongning; Qin, Bin; Xiong, Yongqian; Fan, Kuanjun; Pei, Yuanji

    2018-04-01

    Huazhong University of Science and Technology (HUST) has built a compact linac-based terahertz free electron laser (THz-FEL) prototype. In order to achieve compact structure, the linac uses collinear load cells instead of conventional output coupler to absorb remanent power at the end of linac. The new designed structure is confronted with rf breakdown problem after a long time conditioning process, so we tried to figure out the breakdown site in the linac. Without transmitted signal, we propose two methods to analyze the breakdown site mainly based on the forward and the reflected power signals. One method focuses on the time relationship of the two signals while the other focuses on the amplitude. Both the two methods indicate the breakdown events happened at the end of the linac and more likely in the first or the second load cell.

  14. Do alcohol excise taxes affect traffic accidents? Evidence from Estonia.

    PubMed

    Saar, Indrek

    2015-01-01

    This article examines the association between alcohol excise tax rates and alcohol-related traffic accidents in Estonia. Monthly time series of traffic accidents involving drunken motor vehicle drivers from 1998 through 2013 were regressed on real average alcohol excise tax rates while controlling for changes in economic conditions and the traffic environment. Specifically, regression models with autoregressive integrated moving average (ARIMA) errors were estimated in order to deal with serial correlation in residuals. Counterfactual models were also estimated in order to check the robustness of the results, using the level of non-alcohol-related traffic accidents as a dependent variable. A statistically significant (P <.01) strong negative relationship between the real average alcohol excise tax rate and alcohol-related traffic accidents was disclosed under alternative model specifications. For instance, the regression model with ARIMA (0, 1, 1)(0, 1, 1) errors revealed that a 1-unit increase in the tax rate is associated with a 1.6% decrease in the level of accidents per 100,000 population involving drunk motor vehicle drivers. No similar association was found in the cases of counterfactual models for non-alcohol-related traffic accidents. This article indicates that the level of alcohol-related traffic accidents in Estonia has been affected by changes in real average alcohol excise taxes during the period 1998-2013. Therefore, in addition to other measures, the use of alcohol taxation is warranted as a policy instrument in tackling alcohol-related traffic accidents.

  15. Visualization of Traffic Accidents

    NASA Technical Reports Server (NTRS)

    Wang, Jie; Shen, Yuzhong; Khattak, Asad

    2010-01-01

    Traffic accidents have tremendous impact on society. Annually approximately 6.4 million vehicle accidents are reported by police in the US and nearly half of them result in catastrophic injuries. Visualizations of traffic accidents using geographic information systems (GIS) greatly facilitate handling and analysis of traffic accidents in many aspects. Environmental Systems Research Institute (ESRI), Inc. is the world leader in GIS research and development. ArcGIS, a software package developed by ESRI, has the capabilities to display events associated with a road network, such as accident locations, and pavement quality. But when event locations related to a road network are processed, the existing algorithm used by ArcGIS does not utilize all the information related to the routes of the road network and produces erroneous visualization results of event locations. This software bug causes serious problems for applications in which accurate location information is critical for emergency responses, such as traffic accidents. This paper aims to address this problem and proposes an improved method that utilizes all relevant information of traffic accidents, namely, route number, direction, and mile post, and extracts correct event locations for accurate traffic accident visualization and analysis. The proposed method generates a new shape file for traffic accidents and displays them on top of the existing road network in ArcGIS. Visualization of traffic accidents along Hampton Roads Bridge Tunnel is included to demonstrate the effectiveness of the proposed method.

  16. Accidents of Electrical and Mechanical Works for Public Sector Projects in Hong Kong.

    PubMed

    Wong, Francis K W; Chan, Albert P C; Wong, Andy K D; Hon, Carol K H; Choi, Tracy N Y

    2018-03-10

    A study on electrical and mechanical (E&M) works-related accidents for public sector projects provided the opportunity to gain a better understanding of the causes of accidents by analyzing the circumstances of all E&M works accidents. The research aims to examine accidents of E&M works which happened in public sector projects. A total of 421 E&M works-related accidents in the "Public Works Programme Construction Site Safety and Environmental Statistics" (PCSES) system were extracted for analysis. Two-step cluster analysis was conducted to classify the E&M accidents into different groups. The results identified three E&M accidents groups: (1) electricians with over 15 years of experience were prone to 'fall of person from height'; (2) electricians with zero to five years of experience were prone to 'slip, trip or fall on same level'; (3) air-conditioning workers with zero to five years of experience were prone to multiple types of accidents. Practical measures were recommended for each specific cluster group to avoid recurrence of similar accidents. The accident analysis would be vital for industry practitioners to enhance the safety performance of public sector projects. This study contributes to filling the knowledge gap of how and why E&M accidents occur and promulgating preventive measures for E&M accidents which have been under researched.

  17. Accidents of Electrical and Mechanical Works for Public Sector Projects in Hong Kong

    PubMed Central

    Wong, Francis K. W.; Chan, Albert P. C.; Wong, Andy K. D.; Choi, Tracy N. Y.

    2018-01-01

    A study on electrical and mechanical (E&M) works-related accidents for public sector projects provided the opportunity to gain a better understanding of the causes of accidents by analyzing the circumstances of all E&M works accidents. The research aims to examine accidents of E&M works which happened in public sector projects. A total of 421 E&M works-related accidents in the “Public Works Programme Construction Site Safety and Environmental Statistics” (PCSES) system were extracted for analysis. Two-step cluster analysis was conducted to classify the E&M accidents into different groups. The results identified three E&M accidents groups: (1) electricians with over 15 years of experience were prone to ‘fall of person from height’; (2) electricians with zero to five years of experience were prone to ‘slip, trip or fall on same level’; (3) air-conditioning workers with zero to five years of experience were prone to multiple types of accidents. Practical measures were recommended for each specific cluster group to avoid recurrence of similar accidents. The accident analysis would be vital for industry practitioners to enhance the safety performance of public sector projects. This study contributes to filling the knowledge gap of how and why E&M accidents occur and promulgating preventive measures for E&M accidents which have been under researched. PMID:29534429

  18. Occupational accidents aboard merchant ships

    PubMed Central

    Hansen, H; Nielsen, D; Frydenberg, M

    2002-01-01

    Objectives: To investigate the frequency, circumstances, and causes of occupational accidents aboard merchant ships in international trade, and to identify risk factors for the occurrence of occupational accidents as well as dangerous working situations where possible preventive measures may be initiated. Methods: The study is a historical follow up on occupational accidents among crew aboard Danish merchant ships in the period 1993–7. Data were extracted from the Danish Maritime Authority and insurance data. Exact data on time at risk were available. Results: A total of 1993 accidents were identified during a total of 31 140 years at sea. Among these, 209 accidents resulted in permanent disability of 5% or more, and 27 were fatal. The mean risk of having an occupational accident was 6.4/100 years at sea and the risk of an accident causing a permanent disability of 5% or more was 0.67/100 years aboard. Relative risks for notified accidents and accidents causing permanent disability of 5% or more were calculated in a multivariate analysis including ship type, occupation, age, time on board, change of ship since last employment period, and nationality. Foreigners had a considerably lower recorded rate of accidents than Danish citizens. Age was a major risk factor for accidents causing permanent disability. Change of ship and the first period aboard a particular ship were identified as risk factors. Walking from one place to another aboard the ship caused serious accidents. The most serious accidents happened on deck. Conclusions: It was possible to clearly identify work situations and specific risk factors for accidents aboard merchant ships. Most accidents happened while performing daily routine duties. Preventive measures should focus on workplace instructions for all important functions aboard and also on the prevention of accidents caused by walking around aboard the ship. PMID:11850550

  19. A kinetic comparison of back-loading and head-loading in Xhosa women.

    PubMed

    Lloyd, R; Parr, B; Davies, S; Cooke, C

    2011-04-01

    The purpose of this study was to compare the kinetic responses associated with ground reaction force measurements to both head-loading and back-loading in a group of Xhosa women. Altogether, 16 women were divided into two groups based on their experience of head-loading. They walked over a force plate in three conditions: unloaded or carrying 20 kg in either a backpack or on their head. The most striking finding was that there was no difference in kinetic response to head-loading as a consequence of previous experience. Considering the differences between the load carriage methods, most changes were consistent with increasing load. Head-loading was, however, associated with a shorter contact time, smaller thrust maximum and greater vertical force minimum than back-loading. Both loading conditions differed from unloaded walking for a number of temporal variables associated with the ground contact phase, e.g. vertical impact peak was delayed whilst vertical thrust maximum occurred earlier. STATEMENT OF RELEVANCE: Consideration of the kinetics of head and back load carriage in African women is important from a health and safety perspective, providing an understanding of the mechanical adaptations associated with both forms of load carriage for a group of people for whom such load carriage is a daily necessity.

  20. [Optimization on trehalose loading technique as protective conditioning for lyophilization of human platelets].

    PubMed

    Liu, Jing-Han; Zhou, Jun; Ouyang, Xi-Lin; Li, Xi-Jin; Lu, Fa-Qiang

    2005-08-01

    This study was aimed to further optimize trehalose loading technique including loading temperature, loading time, loading solution and loading concentration of trehalose, based on the established parameters. Loading efficiency in plasma was compared with that in buffer at 37 degrees C; the curves of intracellular trehalose concentration versus loading time at 37 degrees C and 16 degrees C were measured; curves of mean platelet volume (MPV) versus loading time and loading concentration were investigated and compared. According to results obtained, the loaing time, loading temperature, loading solution and trehalose concentration were ascertained for high loading efficiency of trehalose into human platelet. The results showed that the loading efficiency in plasma was markedly higher than that in buffer at 37 degrees C, the loading efficiency in plasma at 37 degrees C was significantly higher than that at 16 degrees C and reached 19.51% after loading for 4 hours, but 6.16% at 16 degrees C. MPV at 16 degrees C was increased by 43.2% than that at 37 degrees C, but had no distinct changes with loading time and loading concentration. In loading at 37 degrees C, MPV increased with loading time and loading concentration positively. Loading time and loading concentration displayed synergetic effect on MPV. MPV increased with loading time and concentration while trehalose loading concentration was above 50 mmol/L. It is concluded that the optimization parameters of trehalose loading technique are 37 degrees C (temperature), 4 hours (leading time), plasma (loading solution), 50 mmol/L (feasible trehalose concentration). The trehalose concentration can be adjusted to meet the requirement of lyophilization.

  1. Dynamics of the precessing vortex rope and its interaction with the system at Francis turbines part load operating conditions

    NASA Astrophysics Data System (ADS)

    Favrel, A.; Müller, A.; Landry, C.; Gomes, J.; Yamamoto, K.; Avellan, F.

    2017-04-01

    At part load conditions, Francis turbines experience the formation of a cavitation vortex rope at the runner outlet whose precession acts as a pressure excitation source for the hydraulic circuit. This can lead to hydro-acoustic resonances characterized by high pressure pulsations, as well as torque and output power fluctuations. This study highlights the influence of the discharge factor on both the vortex parameters and the pressure excitation source by performing Particle Image Velocimetry (PIV) and pressure measurements. Moreover, it is shown that the occurrence of hydro-acoustic resonances in cavitation conditions mainly depend on the swirl degree of the flow independently of the speed factor. Empirical laws linking both natural and precession frequencies with the operating parameters of the machine are, then, derived, enabling the prediction of resonance conditions on the complete part load operating range of the turbine.

  2. Attention-Deficit/Hyperactivity Disorder and Fatal Accidents in Aviation Medicine.

    PubMed

    Laukkala, Tanja; Bor, Robert; Budowle, Bruce; Sajantila, Antti; Navathe, Pooshan; Sainio, Markku; Vuorio, Alpo

    2017-09-01

    Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with symptoms of inattention and/or hyperactivity-impulsivity that interfere with functioning and/or development. ADHD occurs in about 2.5% of adults. ADHD can be an excluding medical condition among pilots due to the risk of attentional degradation and therefore impact on flight safety. Diagnosis of ADHD is complex, which complicates aeromedical assessment. This study highlights fatal accident cases among pilots with ADHD and discusses protocols to detect its presence to help to assess its importance to flight safety. To identify fatal accidents in aviation (including airplanes, helicopters, balloons, and gliders) in the United States between the years 2000 to 2015, the National Transportation Safety Board (NTSB) database was searched with the terms ADHD, attention deficit hyperactivity disorder, and attention deficit disorder (ADD). The NTSB database search for fatal aviation accidents possibly associated with ADHD yielded four accident cases of interest in the United States [4/4894 (0.08%)]. Two of the pilots had ADHD diagnosed by a doctor, one was reported by a family member, and one by a flight instructor. An additional five cases were identified searching for ADD [5/4894 (0.1%)]. Altogether, combined ADHD and ADD cases yielded nine accident cases of interest (0.18%). It is generally accepted by aviation regulatory authorities that ADHD is a disqualifying neurological condition. Yet FAA and CASA provide specific protocols for tailor-made pilot assessment. Accurate evaluation of ADHD is essential because of its potential negative impact on aviation safety.Laukkala T, Bor R, Budowle B, Sajantila A, Navathe P, Sainio M, Vuorio A. Attention-deficit/hyperactivity disorder and fatal accidents in aviation medicine. Aerosp Med Hum Perform. 2017; 88(9):871-875.

  3. Low cognitive load strengthens distractor interference while high load attenuates when cognitive load and distractor possess similar visual characteristics.

    PubMed

    Minamoto, Takehiro; Shipstead, Zach; Osaka, Naoyuki; Engle, Randall W

    2015-07-01

    Studies on visual cognitive load have reported inconsistent effects of distractor interference when distractors have visual characteristic that are similar to the cognitive load. Some studies have shown that the cognitive load enhances distractor interference, while others reported an attenuating effect. We attribute these inconsistencies to the amount of cognitive load that a person is required to maintain. Lower amounts of cognitive load increase distractor interference by orienting attention toward visually similar distractors. Higher amounts of cognitive load attenuate distractor interference by depleting attentional resources needed to process distractors. In the present study, cognitive load consisted of faces (Experiments 1-3) or scenes (Experiment 2). Participants performed a selective attention task in which they ignored face distractors while judging a color of a target dot presented nearby, under differing amounts of load. Across these experiments distractor interference was greater in the low-load condition and smaller in the high-load condition when the content of the cognitive load had similar visual characteristic to the distractors. We also found that when a series of judgments needed to be made, the effect was apparent for the first trial but not for the second. We further tested an involvement of working memory capacity (WMC) in the load effect (Experiment 3). Interestingly, both high and low WMC groups received an equivalent effect of the cognitive load in the first distractor, suggesting these effects are fairly automatic.

  4. [Sports accidents: 1963-1973 statistics].

    PubMed

    Fasler, S

    1976-01-01

    Every year, the Swiss Accident Insurance Administration is paying a considerable amount of money for sports accidents. From 1963 to 1973 the number of these accidents has increased more markedly than other types of accidents. Different tendencies can be observed in the different types of sports: skiing accidents have, after a long period of retrogression until 1973, shown a noticeable augmentation again. Football accidents and accidents in other types of sports have on the other hand increased year by year. Mountaineering and aquatic sports often result in fatal accidents. The numerous preventive measures in skiing accidents have obviously been successful. Not only the fractures have decreased, but also the average number of days where sickness benefit was paid. Next to the traffic accidents, the skiing accidents are the most expensive ones. The nature of the healing cost in sports accidents has changed during the period from 1967 to 1972, depending on the different types of sports. In particular, hospital costs have changed considerably. The number of medical consultations per accident has decreased. Payment of sickness benefit has followed the development of the salaries on the one hand and the modifications of the number of lost days on the other. Finally, the costs of the annuities show more or less the same tendency as the ones for sickness benefit. A very gross estimation on the economical losses through sports accidents in Switzerland makes us believe that the direct and indirect costs actually amount to more than one thousand millions of Swiss Francs per year.

  5. Accident analysis of heavy water cooled thorium breeder reactor

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

    Yulianti, Yanti; Su’ud, Zaki; Takaki, Naoyuki

    2015-04-16

    . The power reactor has a peak value before reactor has new balance condition. The analysis showed that temperatures of fuel and claddings during accident are still below limitations which are in secure condition.« less

  6. Farm accidents in children.

    PubMed Central

    Cameron, D.; Bishop, C.; Sibert, J. R.

    1992-01-01

    OBJECTIVE--To examine the problem of accidental injury to children on farms. DESIGN--Prospective county based study of children presenting to accident and emergency departments over 12 months with injuries sustained in a farm setting and nationwide review of fatal childhood farm accidents over the four years April 1986 to March 1990. SETTING--Accident and emergency departments in Aberystwyth, Carmarthen, Haverfordwest, and Llanelli and fatal accidents in England, Scotland, and Wales notified to the Health and Safety Executive register. SUBJECTS--Children aged under 16. MAIN OUTCOME MEASURE--Death or injury after farm related accidents. RESULTS--65 accidents were recorded, including 18 fractures. Nine accidents necessitated admission to hospital for a mean of two (range one to four) days. 13 incidents were related to tractors and other machinery; 24 were due to falls. None of these incidents were reported under the statutory notification scheme. 33 deaths were notified, eight related to tractors and allied machinery and 10 related to falling objects. CONCLUSIONS--Although safety is improving, the farm remains a dangerous environment for children. Enforcement of existing safety legislation with significant penalties and targeting of safety education will help reduce accident rates further. PMID:1638192

  7. Cognitive processing load across a wide range of listening conditions: insights from pupillometry.

    PubMed

    Zekveld, Adriana A; Kramer, Sophia E

    2014-03-01

    The pupil response to speech masked by interfering speech was assessed across an intelligibility range from 0% to 99% correct. In total, 37 participants aged between 18 and 36 years and with normal hearing were included. Pupil dilation was largest at intermediate intelligibility levels, smaller at high intelligibility, and slightly smaller at very difficult levels. Participants who reported that they often gave up listening at low intelligibility levels had smaller pupil dilations in these conditions. Participants who were good at reading masked text had relatively large pupil dilation when intelligibility was low. We conclude that the pupil response is sensitive to processing load, and possibly reflects cognitive overload in difficult conditions. It seems affected by methodological aspects and individual abilities, but does not reflect subjective ratings. Copyright © 2014 Society for Psychophysiological Research.

  8. A structural colour ornament correlates positively with parasite load and body condition in an insular lizard species

    NASA Astrophysics Data System (ADS)

    Megía-Palma, Rodrigo; Martínez, Javier; Merino, Santiago

    2016-08-01

    Pigment-based ornaments in vertebrates may reflect the body condition or health status of the individual in correlation with environmental stress and hormonal balance. Among the environmental factors shaping sexual colouration, parasitic infections have been stressed as an important evolutionary pressure constraining the maintenance of pigment-based ornaments. However, the honesty of structure-based ornaments in vertebrates is still under debate. Structural UV-biased ornaments in Gallotia lizards were described as a trait used by conspecifics during mate and rival assessment suggesting the reliability of these signals. We investigated the relationship between parasitaemia, body condition and a structural-based ornament present in the cheek of the sexually dichromatic Canarian lacertid Gallotia galloti in a population with an almost 100 % prevalence of haemoparasites. Using spectrophotometric techniques, we found that males with higher values of cheek UV chroma were infected with more haemoparasites. No significant relationship was found between haemoparasite load and body condition. However, males with higher cheek UV chroma showed significantly better body condition. In addition, we found that cheek hue was significantly related to body condition of individuals in both sexes. In males, cheek reflectivity biased towards the UV range was significantly related to better body condition. In females, those individuals with better body condition showed more whitish cheeks with less UV suggesting that cheek hue serves as an intersexual signal for sex recognition. We conclude that the positive relationship between cheek chroma and parasite load in male lizards is compatible with both differential density of melanin and iridophore arrangement in the dermis conveying an individual's ability to cope with environmental stress.

  9. Effect of finite element model loading condition on fracture risk assessment in men and women: the AGES-Reykjavik study.

    PubMed

    Keyak, J H; Sigurdsson, S; Karlsdottir, G S; Oskarsdottir, D; Sigmarsdottir, A; Kornak, J; Harris, T B; Sigurdsson, G; Jonsson, B Y; Siggeirsdottir, K; Eiriksdottir, G; Gudnason, V; Lang, T F

    2013-11-01

    Proximal femoral (hip) strength computed by subject-specific CT scan-based finite element (FE) models has been explored as an improved measure for identifying subjects at risk of hip fracture. However, to our knowledge, no published study has reported the effect of loading condition on the association between incident hip fracture and hip strength. In the present study, we performed a nested age- and sex-matched case-control study in the Age Gene/Environment Susceptibility (AGES) Reykjavik cohort. Baseline (pre-fracture) quantitative CT (QCT) scans of 5500 older male and female subjects were obtained. During 4-7years follow-up, 51 men and 77 women sustained hip fractures. Ninety-seven men and 152 women were randomly selected as controls from a pool of age- and sex-matched subjects. From the QCT data, FE models employing nonlinear material properties computed FE-strength of the left hip of each subject in loading from a fall onto the posterolateral (FPL), posterior (FP) and lateral (FL) aspects of the greater trochanter (patent pending). For comparison, FE strength in stance loading (FStance) and total femur areal bone mineral density (aBMD) were also computed. For all loading conditions, the reductions in strength associated with fracture in men were more than twice those in women (p≤0.01). For fall loading specifically, posterolateral loading in men and posterior loading in women were most strongly associated with incident hip fracture. After adjusting for aBMD, the association between FP and fracture in women fell short of statistical significance (p=0.08), indicating that FE strength provides little advantage over aBMD for identifying female hip fracture subjects. However, in men, after controlling for aBMD, FPL was 424N (11%) less in subjects with fractures than in controls (p=0.003). Thus, in men, FE models of posterolateral loading include information about incident hip fracture beyond that in aBMD. © 2013.

  10. French policy for managing the post-accident phase of a nuclear accident.

    PubMed

    Gallay, F; Godet, J L; Niel, J C

    2015-06-01

    In 2005, at the request of the French Government, the Nuclear Safety Authority (ASN) established a Steering Committee for the Management of the Post-Accident Phase of a Nuclear Accident or a Radiological Emergency, with the objective of establishing a policy framework. Under the supervision of ASN, this Committee, involving several tens of experts from different backgrounds (e.g. relevant ministerial offices, expert agencies, local information commissions around nuclear installations, non-governmental organisations, elected officials, licensees, and international experts), developed a number of recommendations over a 7-year period. First published in November 2012, these recommendations cover the immediate post-emergency situation, and the transition and longer-term periods of the post-accident phase in the case of medium-scale nuclear accidents causing short-term radioactive release (less than 24 h) that might occur at French nuclear facilities. They also apply to actions to be undertaken in the event of accidents during the transportation of radioactive materials. These recommendations are an important first step in preparation for the management of a post-accident situation in France in the case of a nuclear accident. © The Chartered Institution of Building Services Engineers 2014.

  11. The Factors of Soldier’s Load

    DTIC Science & Technology

    1994-06-03

    transport , the effects of technology, terrain and weather, and physical conditioning. Load, Soidier’s Load, Rucksack, Physical Conditioning, Combat Load...Fighting Load, Sustainment Load, Approach March Load, Fear, Fatigue, Risk, Training, Transport , Techn-logy UNCLASSIFIED UNCLASSIFIED UNCLASSIFIED I .1 THE...standards, myths of peacetime training, the nature of the soldier, lack of transport , the effects of technology, terrain and weather, and physical

  12. Damage detection methodology under variable load conditions based on strain field pattern recognition using FBGs, nonlinear principal component analysis, and clustering techniques

    NASA Astrophysics Data System (ADS)

    Sierra-Pérez, Julián; Torres-Arredondo, M.-A.; Alvarez-Montoya, Joham

    2018-01-01

    Structural health monitoring consists of using sensors integrated within structures together with algorithms to perform load monitoring, damage detection, damage location, damage size and severity, and prognosis. One possibility is to use strain sensors to infer structural integrity by comparing patterns in the strain field between the pristine and damaged conditions. In previous works, the authors have demonstrated that it is possible to detect small defects based on strain field pattern recognition by using robust machine learning techniques. They have focused on methodologies based on principal component analysis (PCA) and on the development of several unfolding and standardization techniques, which allow dealing with multiple load conditions. However, before a real implementation of this approach in engineering structures, changes in the strain field due to conditions different from damage occurrence need to be isolated. Since load conditions may vary in most engineering structures and promote significant changes in the strain field, it is necessary to implement novel techniques for uncoupling such changes from those produced by damage occurrence. A damage detection methodology based on optimal baseline selection (OBS) by means of clustering techniques is presented. The methodology includes the use of hierarchical nonlinear PCA as a nonlinear modeling technique in conjunction with Q and nonlinear-T 2 damage indices. The methodology is experimentally validated using strain measurements obtained by 32 fiber Bragg grating sensors bonded to an aluminum beam under dynamic bending loads and simultaneously submitted to variations in its pitch angle. The results demonstrated the capability of the methodology for clustering data according to 13 different load conditions (pitch angles), performing the OBS and detecting six different damages induced in a cumulative way. The proposed methodology showed a true positive rate of 100% and a false positive rate of 1.28% for a

  13. Performance Evaluation of UPQC under Nonlinear Unbalanced Load Conditions Using Synchronous Reference Frame Based Control

    NASA Astrophysics Data System (ADS)

    Kota, Venkata Reddy; Vinnakoti, Sudheer

    2017-12-01

    Today, maintaining Power Quality (PQ) is very important in the growing competent world. With new equipments and devices, new challenges are also being put before power system operators. Unified Power Quality Conditioner (UPQC) is proposed to mitigate many power quality problems and to improve the performance of the power system. In this paper, an UPQC with Fuzzy Logic controller for capacitor voltage balancing is proposed in Synchronous Reference Frame (SRF) based control with Modified Phased Locked Loop (MPLL). The proposed controller with SRF-MPLL based control is tested under non-linear and unbalanced load conditions. The system is developed in Matlab/Simulink and its performance is analyzed under various conditions like non-linear, unbalanced load and polluted supply voltage including voltage sag/swells. Active and reactive power flow in the system, power factor and %THD of voltages and currents before and after compensation are also analyzed in this work. Results prove the applicability of the proposed scheme for power quality improvement. It is observed that the fuzzy controller gives better performance than PI controller with faster capacitor voltage balancing and also improves the dynamic performance of the system.

  14. Effect of Different Loading Conditions on the Nucleation and Development of Shear Zones Around Material Heterogeneities

    NASA Astrophysics Data System (ADS)

    Rybacki, E.; Nardini, L.; Morales, L. F.; Dresen, G.

    2017-12-01

    Rock deformation at depths in the Earth's crust is often localized in high temperature shear zones, which occur in the field at different scales and in a variety of lithologies. The presence of material heterogeneities has long been recognized to be an important cause for shear zones evolution, but the mechanisms controlling initiation and development of localization are not fully understood, and the question of which loading conditions (constant stress or constant deformation rate) are most favourable is still open. To better understand the effect of boundary conditions on shear zone nucleation around heterogeneities, we performed a series of torsion experiments under constant twist rate (CTR) and constant torque (CT) conditions in a Paterson-type deformation apparatus. The sample assemblage consisted of copper-jacketed Carrara marble hollow cylinders with one weak inclusion of Solnhofen limestone. The CTR experiments were performed at maximum bulk strain rates of 1.8-1.9*10-4 s-1, yielding shear stresses of 19-20 MPa. CT tests were conducted at shear stresses between 18.4 and 19.8 MPa resulting in shear strain rates of 1-2*10-4 s-1. All experiments were run at 900 °C temperature and 400 MPa confining pressure. Maximum bulk shear strains (γ) were ca. 0.3 and 1. Strain localized within the host marble in front of the inclusion in an area termed process zone. Here grain size reduction is intense and local shear strain (estimated from markers on the jackets) is up to 8 times higher than the applied bulk strain, rapidly dropping to 2 times higher at larger distance from the inclusion. The evolution of key microstructural parameters such as average grain size and average grain orientation spread (GOS, a measure of lattice distortion) within the process zone, determined by electron backscatter diffraction analysis, differs significantly as a function of loading conditions. Both parameters indicate that, independent of bulk strain and distance from the inclusion, the

  15. Site restoration: Estimation of attributable costs from plutonium-dispersal accidents

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

    Chanin, D.I.; Murfin, W.B.

    1996-05-01

    A nuclear weapons accident is an extremely unlikely event due to the extensive care taken in operations. However, under some hypothetical accident conditions, plutonium might be dispersed to the environment. This would result in costs being incurred by the government to remediate the site and compensate for losses. This study is a multi-disciplinary evaluation of the potential scope of the post-accident response that includes technical factors, current and proposed legal requirements and constraints, as well as social/political factors that could influence decision making. The study provides parameters that can be used to assess economic costs for accidents postulated to occurmore » in urban areas, Midwest farmland, Western rangeland, and forest. Per-area remediation costs have been estimated, using industry-standard methods, for both expedited and extended remediation. Expedited remediation costs have been evaluated for highways, airports, and urban areas. Extended remediation costs have been evaluated for all land uses except highways and airports. The inclusion of cost estimates in risk assessments, together with the conventional estimation of doses and health effects, allows a fuller understanding of the post-accident environment. The insights obtained can be used to minimize economic risks by evaluation of operational and design alternatives, and through development of improved capabilities for accident response.« less

  16. Influence evaluation of loading conditions during pressurized thermal shock transients based on thermal-hydraulics and structural analyses

    NASA Astrophysics Data System (ADS)

    Katsuyama, Jinya; Uno, Shumpei; Watanabe, Tadashi; Li, Yinsheng

    2018-03-01

    The thermal hydraulic (TH) behavior of coolant water is a key factor in the structural integrity assessments on reactor pressure vessels (RPVs) of pressurized water reactors (PWRs) under pressurized thermal shock (PTS) events, because the TH behavior may affect the loading conditions in the assessment. From the viewpoint of TH behavior, configuration of plant equipment and their dimensions, and operator action time considerably influence various parameters, such as the temperature and flow rate of coolant water and inner pressure. In this study, to investigate the influence of the operator action time on TH behavior during a PTS event, we developed an analysis model for a typical Japanese PWR plant, including the RPV and the main components of both primary and secondary systems, and performed TH analyses by using a system analysis code called RELAP5. We applied two different operator action times based on the Japanese and the United States (US) rules: Operators may act after 10 min (Japanese rules) and 30 min (the US rules) after the occurrence of PTS events. Based on the results of TH analysis with different operator action times, we also performed structural analyses for evaluating thermal-stress distributions in the RPV during PTS events as loading conditions in the structural integrity assessment. From the analysis results, it was clarified that differences in operator action times significantly affect TH behavior and loading conditions, as the Japanese rule may lead to lower stresses than that under the US rule because an earlier operator action caused lower pressure in the RPV.

  17. Alcohol is the main factor in excess traffic accident fatalities in France.

    PubMed

    Reynaud, Michel; Le Breton, Patrick; Gilot, Bertrand; Vervialle, Françoise; Falissard, Bruno

    2002-12-01

    The aim of this study was to better evaluate the role of alcohol drinking in fatalities linked to road traffic accidents. The data of accidents were collected by a French official agency from police records, including many variables, among which was a blood alcohol test. They were analyzed in a descriptive way and toward a logistic regression. This exhaustive database comprised all of the 500,961 accidents with casualties that involved less than three vehicles (28,506 fatal accidents) recorded in France during a 52 month period (September 1995 to December 1999). The results of the alcohol tests were known in 78.7 of the drivers. The blood alcohol concentration was over the legal limit (0.50 g/L in France) in 9.8% of the accidents with casualties overall. Considering only fatal accidents, the rate of positive alcohol test in drivers was approximately 31.5%. This rate varied depending on the period and the type of accident, raising up to 71.2% in single-vehicle accidents (loss of control) at night during the weekend. The percentage of positive alcohol tests also dramatically increased following the number of fatalities per accident (87.5% in single-vehicle accidents during weekend nights involving three or more killed). The logistic regression in single-vehicle accident shows that the higher odds ratios concern the positive blood alcohol test (OR = 4.19), clearly overwhelming the other precipitating factors of accidents (age of driver, meteorological conditions, time of day, and other factors). Drinking alcohol before driving is a well known factor of accidents. We clearly demonstrate here that it is the main factor leading to deaths linked to road traffic accidents in France. The results are strengthened, and some analyses are allowed, by the exceptional features of our database. The authors emphasize the need for prevention measures.

  18. Shuttle Program Loads Integration: Going From Concept to Operations and Staying Successful

    NASA Technical Reports Server (NTRS)

    Bernstein, Karen; James, George; Mackey, alden; Murphy, Neil C.; Brolliar, Steve

    2011-01-01

    From the beginning of the Shuttle Program to its end, integrated loads and dynamics analyses and tests have been critical in shaping the vehicle design and operational decisions for NASA and its customers. Starting with scaled models and simple mathematical simulations of the structural dynamics, engineers defined the required structural stiffness and predicted the limit loads for each element of the system. Early structural tests provided reasonable confidence that the models and predictions were good. The first launch of the Space Shuttle brought surprises, though, when the ignition overpressure event caused a forward fuel tank support strut to buckle, among several unexpected effects. The launch pad and other ground equipment became an integral part of the system integration, especially where the acoustic and pressure environments of ignition and lift-off were concerned. Following the Challenger accident, operating limits were changed in response to new understandings of how the integrated system performed. Controlling loads while maximizing performance was a key tenet of the Performance Enhancement design process, which enabled construction of the International Space Station. During the return to flight after the Columbia accident, engineers grew to understand that loads during the roll maneuver were also important to the vehicle s structural margin and life. At this point the crawler transport from the Vehicle Assembly Building to the launch pad also became a part of the integrated loads analysis. Even in the last years of the Space Shuttle Program, new data still provided interesting insights into this complicated and fascinating spaceship. This paper will present some examples of the important findings by the team of specialists that supported the Integrated Loads and Dynamics Panel for the Space Shuttle Program.

  19. The Evaluation of a Test Device for Human Occupant Restraint (THOR) Under Vertical Loading Conditions: Part 1 - Experimental Setup and Results

    NASA Technical Reports Server (NTRS)

    Littell, Justin D.; Annett, Martin S.

    2013-01-01

    A series of 16 vertical tests were conducted on a Test Device for Human Occupant Restraint (THOR) - NT 50th percentile Anthropomorphic Test Device (ATD) at NASA Langley Research Center (LaRC). The purpose of the tests conducted at NASA LaRC was threefold. The first was to add vertical response data to the growing test database for THOR-NT development and validation. Second, the THOR-NT analytical computational models currently in development must be validated for the vertical loading environment. The computational models have been calibrated for frontal crash environments with concentration on accurately replicating head/neck, thoracic, and lower extremity responses. Finally, familiarity with the THOR ATD is necessary because NASA is interested in evaluating advanced ATDs for use in future flight and research projects. The THOR was subjected to vertical loading conditions ranging between 5 and 16 g in magnitude and 40 to 120 milliseconds (msec) in duration. It was also tested under conditions identical to previous tests conducted on the Hybrid II and III ATDs to allow comparisons to be made. Variations in the test setup were also introduced, such as the addition of a footrest in an attempt to offload some of the impact load into the legs. A full data set of the THOR-NT ATD will be presented and discussed. Results from the tests show that the THOR was largely insensitive to differences in the loading conditions, perhaps due in part to their small magnitudes. THOR responses, when compared to the Hybrid II and III in the lumbar region, demonstrated that the THOR more closely resembled the straight spine Hybrid setup. In the neck region, the THOR behaved more like the Hybrid III. However in both cases, the responses were not identical, indicating that the THOR would show differences in response than the Hybrid II and III ATDs when subjected to identical impact conditions. The addition of a footrest did not significantly affect the THOR response due to the nature of how

  20. The associations of insomnia with costly workplace accidents and errors: results from the America Insomnia Survey.

    PubMed

    Shahly, Victoria; Berglund, Patricia A; Coulouvrat, Catherine; Fitzgerald, Timothy; Hajak, Goeran; Roth, Thomas; Shillington, Alicia C; Stephenson, Judith J; Walsh, James K; Kessler, Ronald C

    2012-10-01

    Insomnia is a common and seriously impairing condition that often goes unrecognized. To examine associations of broadly defined insomnia (ie, meeting inclusion criteria for a diagnosis from International Statistical Classification of Diseases, 10th Revision, DSM-IV, or Research Diagnostic Criteria/International Classification of Sleep Disorders, Second Edition) with costly workplace accidents and errors after excluding other chronic conditions among workers in the America Insomnia Survey (AIS). A national cross-sectional telephone survey (65.0% cooperation rate) of commercially insured health plan members selected from the more than 34 million in the HealthCore Integrated Research Database. Four thousand nine hundred ninety-one employed AIS respondents. Costly workplace accidents or errors in the 12 months before the AIS interview were assessed with one question about workplace accidents "that either caused damage or work disruption with a value of $500 or more" and another about other mistakes "that cost your company $500 or more." Current insomnia with duration of at least 12 months was assessed with the Brief Insomnia Questionnaire, a validated (area under the receiver operating characteristic curve, 0.86 compared with diagnoses based on blinded clinical reappraisal interviews), fully structured diagnostic interview. Eighteen other chronic conditions were assessed with medical/pharmacy claims records and validated self-report scales. Insomnia had a significant odds ratio with workplace accidents and/or errors controlled for other chronic conditions (1.4). The odds ratio did not vary significantly with respondent age, sex, educational level, or comorbidity. The average costs of insomnia-related accidents and errors ($32 062) were significantly higher than those of other accidents and errors ($21 914). Simulations estimated that insomnia was associated with 7.2% of all costly workplace accidents and errors and 23.7% of all the costs of these incidents. These

  1. Reactor Safety Gap Evaluation of Accident Tolerant Components and Severe Accident Analysis

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

    Farmer, Mitchell T.; Bunt, R.; Corradini, M.

    The overall objective of this study was to conduct a technology gap evaluation on accident tolerant components and severe accident analysis methodologies with the goal of identifying any data and/or knowledge gaps that may exist, given the current state of light water reactor (LWR) severe accident research, and additionally augmented by insights obtained from the Fukushima accident. The ultimate benefit of this activity is that the results can be used to refine the Department of Energy’s (DOE) Reactor Safety Technology (RST) research and development (R&D) program plan to address key knowledge gaps in severe accident phenomena and analyses that affectmore » reactor safety and that are not currently being addressed by the industry or the Nuclear Regulatory Commission (NRC).« less

  2. Structural Analysis of the Right Rear Lug of American Airlines Flight 587

    NASA Technical Reports Server (NTRS)

    Raju, Ivatury S.; Glaessgen, Edward H.; Mason, Brian H.; Krishnamurthy, Thiagarajan; Davila, Carlos G.

    2006-01-01

    A detailed finite element analysis of the right rear lug of the American Airlines Flight 587 - Airbus A300-600R was performed as part of the National Transportation Safety Board s failure investigation of the accident that occurred on November 12, 2001. The loads experienced by the right rear lug are evaluated using global models of the vertical tail, local models near the right rear lug, and a global-local analysis procedure. The right rear lug was analyzed using two modeling approaches. In the first approach, solid-shell type modeling is used, and in the second approach, layered-shell type modeling is used. The solid-shell and the layered-shell modeling approaches were used in progressive failure analyses (PFA) to determine the load, mode, and location of failure in the right rear lug under loading representative of an Airbus certification test conducted in 1985 (the 1985-certification test). Both analyses were in excellent agreement with each other on the predicted failure loads, failure mode, and location of failure. The solid-shell type modeling was then used to analyze both a subcomponent test conducted by Airbus in 2003 (the 2003-subcomponent test) and the accident condition. Excellent agreement was observed between the analyses and the observed failures in both cases. The moment, Mx (moment about the fuselage longitudinal axis), has significant effect on the failure load of the lugs. Higher absolute values of Mx give lower failure loads. The predicted load, mode, and location of the failure of the 1985- certification test, 2003-subcomponent test, and the accident condition are in very good agreement. This agreement suggests that the 1985-certification and 2003-subcomponent tests represent the accident condition accurately. The failure mode of the right rear lug for the 1985-certification test, 2003-subcomponent test, and the accident load case is identified as a cleavage-type failure. For the accident case, the predicted failure load for the right rear lug

  3. Persistence of airline accidents.

    PubMed

    Barros, Carlos Pestana; Faria, Joao Ricardo; Gil-Alana, Luis Alberiko

    2010-10-01

    This paper expands on air travel accident research by examining the relationship between air travel accidents and airline traffic or volume in the period from 1927-2006. The theoretical model is based on a representative airline company that aims to maximise its profits, and it utilises a fractional integration approach in order to determine whether there is a persistent pattern over time with respect to air accidents and air traffic. Furthermore, the paper analyses how airline accidents are related to traffic using a fractional cointegration approach. It finds that airline accidents are persistent and that a (non-stationary) fractional cointegration relationship exists between total airline accidents and airline passengers, airline miles and airline revenues, with shocks that affect the long-run equilibrium disappearing in the very long term. Moreover, this relation is negative, which might be due to the fact that air travel is becoming safer and there is greater competition in the airline industry. Policy implications are derived for countering accident events, based on competition and regulation. © 2010 The Author(s). Journal compilation © Overseas Development Institute, 2010.

  4. Compilation of load spectrum of loader drive axle

    NASA Astrophysics Data System (ADS)

    Wei, Yongxiang; Zhu, Haoyue; Tang, Heng; Yuan, Qunwei

    2018-03-01

    In order to study the preparation method of gear fatigue load spectrum for loaders, the load signal of four typical working conditions of loader is collected. The signal that reflects the law of load change is obtained by preprocessing the original signal. The torque of the drive axle is calculated by using the rain flow counting method. According to the operating time ratio of each working condition, the two dimensional load spectrum based on the real working conditions of the drive axle of loader is established by the cycle extrapolation and synthesis method. The two-dimensional load spectrum is converted into one-dimensional load spectrum by means of the mean of torque equal damage method. Torque amplification includes the maximum load torque of the main reduction gear. Based on the theory of equal damage, the accelerated cycles are calculated. In this way, the load spectrum of the loading condition of the drive axle is prepared to reflect loading condition of the loader. The load spectrum can provide reference for fatigue life test and life prediction of loader drive axle.

  5. Study of activities of postmen motorcyclists: a look at motorcycle accidents.

    PubMed

    Nascimento, Lícia Maria Barreto do; Bortolotto, Gracielle Aparecida Orlando

    2012-01-01

    This article presents the steps of transforming the material and organizational aspects in the work environment, beyond the social order for the proper development of activities in the Household Distribution Center, the Postmen Motorcyclists. The demand was made by managers from the accident records, establishing the need to identify the working conditions of postmen motorcyclists, regarding motorcycle accidents occurring on public roads. Based on the characteristics of the steps required by the methodology, was necessary to realize internal and external observations, with the aim of identifying the dynamics of the accident and the collective dimensions of activity which requires a strategy for monitoring the work on the street.

  6. New Technologies for Weather Accident Prevention

    NASA Technical Reports Server (NTRS)

    Stough, H. Paul, III; Watson, James F., Jr.; Daniels, Taumi S.; Martzaklis, Konstantinos S.; Jarrell, Michael A.; Bogue, Rodney K.

    2005-01-01

    Weather is a causal factor in thirty percent of all aviation accidents. Many of these accidents are due to a lack of weather situation awareness by pilots in flight. Improving the strategic and tactical weather information available and its presentation to pilots in flight can enhance weather situation awareness and enable avoidance of adverse conditions. This paper presents technologies for airborne detection, dissemination and display of weather information developed by the National Aeronautics and Space Administration (NASA) in partnership with the Federal Aviation Administration (FAA), National Oceanic and Atmospheric Administration (NOAA), industry and the research community. These technologies, currently in the initial stages of implementation by industry, will provide more precise and timely knowledge of the weather and enable pilots in flight to make decisions that result in safer and more efficient operations.

  7. Effect of load on the tribological properties of hypereutectic Al-Si alloy under boundary lubrication conditions

    NASA Astrophysics Data System (ADS)

    Kumar, Parveen; Wani, M. F.

    2017-11-01

    Researchers reported that the IC engine components (piston, cylinder liner etc) fail due to the friction losses (~45%) and wear losses (~25-40%). So the demand of light weight, low friction and wear resistance alloys increases day by day, which reduces the emission and increases the efficiency of the IC engine. In this connection, tribological tests on hypereutectic Al-25Si alloy were performed using a ball-on-disk configuration under dry and lubricated sliding conditions. Hypereutectic Al-25Si alloy was prepared by rapid solidification process with T6 condition. T6 condition improves the friction, wear and mechanical properties of the alloy. Friction coefficient and wear rate of the alloy was measured under high loads ranging from 100 to 300 N. It was found that the friction coefficient (COF) and wear rate of hypereutectic Al-25Si alloy/steel tribo pair increased with increase in load. Significant reduction in COF and wear rate was accomplished with SAE20W50 engine oil and Si particles act as solid lubricant. Optical microscope, 3D surface profilometer and scanning electron microscope (SEM) coupled with an energy dispersive spectrometer (EDS) were used for characterization the worn surface morphologies. The morphology, size and distribution of high Si particles due to its fabrication process caused the improvements in COF and wear rate under lubricated conditions. Adhesive wear, abrasive wear and plastic deformation acted as the dominant wear mechanism for hypereutectic Al-25Si alloy.

  8. Causes of accidents in terrain parks: an exploratory factor analysis of recreational freestylers' views.

    PubMed

    Carús, Luis

    2014-03-01

    This study examines ski and snowboard terrain park users' views on aspects associated with accidents by identifying and assessing variables that may influence the occurrence of accidents and the resulting injuries. The research was conducted in a major resort in the Spanish Pyrenees, using information gathered from freestyle skiers and snowboarders aged 6 or older. To identify interrelationships among variables and to group the variables belonging to unified concepts, an exploratory factor analysis was performed using varimax rotation. The results revealed 5 factors that grouped the measured variables that may influence the occurrence of accidents while freestyling in terrain parks. The park features, conditions of the activity, and the user's personal conditions were found to have the most substantial influence on the freestylers' perceptions. Variables identified as components of the main factors of accident risk in terrain parks should be incorporated into resort management communication and policies. © 2013 Wilderness Medical Society Published by Wilderness Medical Society All rights reserved.

  9. Civilian Helicopter Search and Rescue Accidents in the United States: 1980 Through 2013.

    PubMed

    Worley, Gordon H

    2015-12-01

    Helicopters are commonly used in search and rescue operations, and accidents have occurred during helicopter search and rescue (HSAR) missions. The purposes of this study were to investigate whether the HSAR accident rate in the United States could be determined and whether any common contributing factors or trends could be identified. Searches were conducted of the National Transportation Safety Board aviation accident database, the records of the major search and rescue and air medical organizations, and the medical and professional literature for reports of HSAR accidents. A total of 47 civilian HSAR accidents were identified during the study. Of these, 43% involved fatal injuries, compared with a 19% fatality rate for US helicopter general aviation accidents during the same time period and a 40% rate for helicopter emergency medical services. The HSAR accidents carried a significantly higher risk of fatal outcomes when compared with helicopter general aviation accidents (2-tailed Fisher's exact test, P < .0005). Accidents that occurred at night and under instrument meteorological conditions did not have a statistically significant increase in percentage of fatal outcomes (P > .05). The number of HSAR missions conducted annually could not be established, so an overall accident rate could not be calculated. Although the overall number of HSAR accidents is small, the percentage of fatal outcomes from HSAR accidents is significantly higher than that from general helicopter aviation accidents and is comparable to that seen for helicopter emergency medical services operations. Further study could help to improve the safety of HSAR flights. Copyright © 2015 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

  10. Traffic Accidents—Chronic Medical Conditions as a Cause

    PubMed Central

    Waller, Julian A.

    1966-01-01

    From comparatively scanty information, an increased traffic accident risk appears to be associated with several chronic medical conditions including alcoholism, cardiovascular disease, epilepsy, diabetes and mental illness. Further study probably will show that medical handicaps other than alcoholism are a factor in from 5 to 10 per cent of traffic accidents. However, in about half of the accidents caused by heart attacks, the individual has no previous knowledge of his illness, and prevention of the accident would not be possible. A selective program for identifying high risk drivers with medical conditions is feasible and warranted, but a program of mass medical examinations for all drivers is not. A very strong relationship has been shown between drunk driving and traffic accidents, and 50 to 75 per cent of all severe and fatal traffic accidents involve the use of alcohol. However, studies have shown that drivers with alcoholism rather than social drinkers represent the preponderance, but not the entirety, of those who get into trouble. A major reduction in the traffic accident toll may thus depend on the early identification and treatment of alcoholism. PMID:18730024

  11. Road accidents caused by sleepy drivers: Update of a Norwegian survey.

    PubMed

    Phillips, Ross Owen; Sagberg, Fridulv

    2013-01-01

    The current study tests, updates and expands a model of factors associated with sleepy driving, originally based on a 1997 survey of accident-involved Norwegian drivers (Sagberg, F., 1999. Road accidents caused by drivers falling asleep. Accident Analysis & Prevention 31, 639-649). The aim is to establish a robust model to inform measures to tackle sleepy driving. The original questions on (i) tiredness-related accidents and (ii) incidents of sleep behind the wheel in the last 12 months were again posed in 2003 and 2008, in independent surveys of Norwegian drivers involved in accidents reported to a large insurance company. According to those drivers at-fault for the accident, tiredness or sleepiness behind the wheel contributed to between 1.9 and 3.9 per cent of all types of accident reported to the insurance company across these years. Accident-involved drivers not at fault for the accident reported a reduction in the incidence of sleep behind the wheel for the preceding year, decreasing from 8.3 per cent in 1997 to 2.9 per cent in 2008. The reasons for this are not clear. According to logistic regression analysis of survey responses, the following factors were robustly associated with road accidents involving sleepy driving: driving off the road; good road conditions; longer distance driven since the start of the trip; and fewer years with a driving licence. The following factors are consistently associated with reports of sleep behind the wheel, whether or not it leads to an accident: being male; driving further per year; being younger; and having sleep-related health problems. Taken together these findings suggest that young, inexperienced male drivers who drive long distances may be a suitable target for road safety campaigns aimed at tackling sleepy driving. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. Analysis of Workplace Accidents in Automotive Repair Workshops in Spain.

    PubMed

    López-Arquillos, Antonio; Rubio-Romero, Juan Carlos

    2016-09-01

    To analyze the effects of the factors associated with different types of injury (superficial wounds, dislocations and sprains, bone fractures, concussion and internal injuries, burns scalding and freezing) caused by occupational accidents in automotive repair workshops. Study of a sample consisting of 89,954 industry accidents reported from 2003 to 2008. Odds ratios were calculated with a 95% confidence interval. Belonging to a small company is a risk factor for suffering three of the five types of injury studied. Women are less likely to suffer burns and superficial wounds, and more likely to suffer dislocations or sprains. Foreign workers are more likely to suffer concussion and internal injuries. Health and safety strategies and accident prevention measures should be individualized and adapted to the type of worker most likely to be injured in each type of accident. Occupational health and safety training courses designed according to worker profile, and improving the participation of the workers in small firms creating regional or roving safety representatives would improve working conditions.

  13. 49 CFR 837.3 - Published reports, material contained in the public accident investigation dockets, and accident...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... public accident investigation dockets, and accident database data. 837.3 Section 837.3 Transportation... investigation dockets, and accident database data. (a) Demands for material contained in the NTSB's official public docket files of its accident investigations, or its computerized accident database(s) shall be...

  14. 49 CFR 837.3 - Published reports, material contained in the public accident investigation dockets, and accident...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... public accident investigation dockets, and accident database data. 837.3 Section 837.3 Transportation... investigation dockets, and accident database data. (a) Demands for material contained in the NTSB's official public docket files of its accident investigations, or its computerized accident database(s) shall be...

  15. 49 CFR 837.3 - Published reports, material contained in the public accident investigation dockets, and accident...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... public accident investigation dockets, and accident database data. 837.3 Section 837.3 Transportation... investigation dockets, and accident database data. (a) Demands for material contained in the NTSB's official public docket files of its accident investigations, or its computerized accident database(s) shall be...

  16. 49 CFR 837.3 - Published reports, material contained in the public accident investigation dockets, and accident...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... public accident investigation dockets, and accident database data. 837.3 Section 837.3 Transportation... investigation dockets, and accident database data. (a) Demands for material contained in the NTSB's official public docket files of its accident investigations, or its computerized accident database(s) shall be...

  17. 49 CFR 837.3 - Published reports, material contained in the public accident investigation dockets, and accident...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... public accident investigation dockets, and accident database data. 837.3 Section 837.3 Transportation... investigation dockets, and accident database data. (a) Demands for material contained in the NTSB's official public docket files of its accident investigations, or its computerized accident database(s) shall be...

  18. Heat up and failure of BWR upper internals during a severe accident

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

    Robb, Kevin R.

    In boiling water reactors, the shroud dome, separators, and dryers above the core are made of approximately 100,000 kg of stainless steel. During a severe accident in which the coolant boils away and exothermic oxidation of zirconium occurs, gases (steam and hydrogen) are superheated in the core region and pass through the upper internals. In this scenario, the upper internals can also be heated by thermal radiation from the hot degrading core. Historically, models of the upper internals have been relatively simple in severe accident codes. The upper internals are typically modeled in MELCOR as two lumped volumes with simplifiedmore » heat transfer characteristics and no structural integrity considerations, and with limited ability to oxidize, melt, and relocate. The potential for and the subsequent impact of the upper internals to heat up, oxidize, fail, and relocate during a severe accident was investigated. A higher fidelity representation of the shroud dome, steam separators, and steam driers was developed in MELCOR v1.8.6 by extending the core region upwards. The MELCOR modeling effort entailed adding 45 additional core cells and control volumes, 98 flow paths, and numerous control functions. The model accounts for the mechanical loading and structural integrity, oxidation, melting, flow area blockage, and relocation of the various components. Consistent with a previous study, the results indicate that the upper internals can reach high temperatures during a severe accident sufficient to lose their structural integrity and relocate. Finally, the additional 100 metric tons of stainless steel debris influences the subsequent in-vessel and ex-vessel accident progression.« less

  19. Heat up and failure of BWR upper internals during a severe accident

    DOE PAGES

    Robb, Kevin R.

    2017-02-21

    In boiling water reactors, the shroud dome, separators, and dryers above the core are made of approximately 100,000 kg of stainless steel. During a severe accident in which the coolant boils away and exothermic oxidation of zirconium occurs, gases (steam and hydrogen) are superheated in the core region and pass through the upper internals. In this scenario, the upper internals can also be heated by thermal radiation from the hot degrading core. Historically, models of the upper internals have been relatively simple in severe accident codes. The upper internals are typically modeled in MELCOR as two lumped volumes with simplifiedmore » heat transfer characteristics and no structural integrity considerations, and with limited ability to oxidize, melt, and relocate. The potential for and the subsequent impact of the upper internals to heat up, oxidize, fail, and relocate during a severe accident was investigated. A higher fidelity representation of the shroud dome, steam separators, and steam driers was developed in MELCOR v1.8.6 by extending the core region upwards. The MELCOR modeling effort entailed adding 45 additional core cells and control volumes, 98 flow paths, and numerous control functions. The model accounts for the mechanical loading and structural integrity, oxidation, melting, flow area blockage, and relocation of the various components. Consistent with a previous study, the results indicate that the upper internals can reach high temperatures during a severe accident sufficient to lose their structural integrity and relocate. Finally, the additional 100 metric tons of stainless steel debris influences the subsequent in-vessel and ex-vessel accident progression.« less

  20. Young drivers' optimism bias for accident risk and driving skill: Accountability and insight experience manipulations.

    PubMed

    White, Melanie J; Cunningham, Lauren C; Titchener, Kirsteen

    2011-07-01

    This study aimed to determine whether two brief, low cost interventions would reduce young drivers' optimism bias for their driving skills and accident risk perceptions. This tendency for such drivers to perceive themselves as more skillful and less prone to driving accidents than their peers may lead to less engagement in precautionary driving behaviours and a greater engagement in more dangerous driving behaviour. 243 young drivers (aged 17-25 years) were randomly allocated to one of three groups: accountability, insight or control. All participants provided both overall and specific situation ratings of their driving skills and accident risk relative to a typical young driver. Prior to completing the questionnaire, those in the accountability condition were first advised that their driving skills and accident risk would be later assessed via a driving simulator. Those in the insight condition first underwent a difficult computer-based hazard perception task designed to provide participants with insight into their potential limitations when responding to hazards in difficult and unpredictable driving situations. Participants in the control condition completed only the questionnaire. Results showed that the accountability manipulation was effective in reducing optimism bias in terms of participants' comparative ratings of their accident risk in specific situations, though only for less experienced drivers. In contrast, among more experienced males, participants in the insight condition showed greater optimism bias for overall accident risk than their counterparts in the accountability or control groups. There were no effects of the manipulations on drivers' skills ratings. The differential effects of the two types of manipulations on optimism bias relating to one's accident risk in different subgroups of the young driver sample highlight the importance of targeting interventions for different levels of experience. Accountability interventions may be beneficial for

  1. Bus drivers' mental conditions and their relation to bus passengers' accidents with a focus on the psychological stress concept.

    PubMed

    Yamada, Yasuyuki; Mizuno, Motoki; Sugiura, Miyuki; Tanaka, Sumio; Mizuno, Yuki; Yanagiya, Toshio; Hirosawa, Masataka

    2008-06-01

    The purpose of this study was to clarify the psychological factors of bus drivers' instability that were related to bus passengers' accidents according to the hypothesis model based on the stress concept of Lazarus and Folkman (1984). This research was carried out in 2006. Participants of the study were 39 Japanese male bus drivers. Their average age was 40.2 (SD: 11.1). The average duration of employment was 4.5 (SD:6.1) years. A questionnaire was used that was composed of items concerning the frequency of bus passengers' accidents, performance of safe driving, job stressors, stress reaction and recognition from others. Based on the results, a model assuming that stress reaction caused by job stressors disturbed the bus driver's safe driving and was associated with passengers' accidents in the bus was verified to some degree. Especially, melancholy and tired feeling toward passengers showed a strong relation to the passengers' accidents in the bus. This suggested much room for intervention. Moreover, the recognition from others of their job was confirmed to act as a control factor of the stress reaction.

  2. Abnormal glucose levels found in transportation accidents : final report.

    DOT National Transportation Integrated Search

    2000-06-01

    Purpose. The Federal Aviation Administration's Office of Aviation Medicine (OAM) is responsible for the certification of pilots with diabetic conditions. Therefore, it is essential for OAM to monitor pilots involved in fatal accidents for abnormal gl...

  3. Tourist visitation impacts of the accident at Three Mile Island

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

    Himmelberger, J.J.; Ogneva-Himmelberger, Y.A.; Baughman, M.L.

    This paper analyzes tourist visitation impacts of the March 27, 1979 accident at Three Mile Island. A review of the literature, supplemented with recollections from Pennsylvanian public officials, are used to specify a conventional tourism impact model which holds that depressed 1979 summer tourism season was more influenced by gasoline shortages and possibly other confounding variables (such as rainy local weather conditions and a polio outbreak) than by the nuclear accident. Regression analysis using monthly visitation data for Hershey Chocolate World, Gettysburg National Park, The Pennsylvania Dutch Convention and Visitor Bureau, and several state parks as dependent variables provide supportmore » for this model. Potential tourism implications of an accident at Yucca Mountain are briefly discussed in light of our findings.« less

  4. Qualification of data obtained during a severe accident. Illustrative examples from TMI-2 evaluations

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

    Rempe, Joy L.; Knudson, Darrell L.

    2015-02-01

    The accidents at the Three Mile Island Unit 2 (TMI-2) Pressurized Water Reactor (PWR) and the Daiichi Units 1, 2, and 3 Boiling Water Reactors (BWRs) provide unique opportunities to evaluate instrumentation exposed to severe accident conditions. Conditions associated with the release of coolant and the hydrogen burn that occurred during the TMI-2 accident exposed instrumentation to harsh conditions, including direct radiation, radioactive contamination, and high humidity with elevated temperatures and pressures. Post-TMI-2 instrumentation evaluation programs focused on data required by TMI-2 operators to assess the condition of the reactor and containment and the effect of mitigating actions taken bymore » these operators. Prior efforts also focused on sensors providing data required for subsequent forensic evaluations and accident simulations. This paper provides additional details related to the formal process used to develop a qualified TMI-2 data base and presents data qualification details for three parameters: reactor coolant system (RCS) pressure; containment building temperature; and containment pressure. These selected examples illustrate the types of activities completed in the TMI-2 data qualification process and the importance of such a qualification effort. These details are described to facilitate implementation of a similar process using data and examinations at the Daiichi Units 1, 2, and 3 reactors so that BWR-specific benefits can be obtained.« less

  5. Displacement Models for THUNDER Actuators having General Loads and Boundary Conditions

    NASA Technical Reports Server (NTRS)

    Wieman, Robert; Smith, Ralph C.; Kackley, Tyson; Ounaies, Zoubeida; Bernd, Jeff; Bushnell, Dennis M. (Technical Monitor)

    2001-01-01

    This paper summarizes techniques for quantifying the displacements generated in THUNDER actuators in response to applied voltages for a variety of boundary conditions and exogenous loads. The PDE (partial differential equations) models for the actuators are constructed in two steps. In the first, previously developed theory quantifying thermal and electrostatic strains is employed to model the actuator shapes which result from the manufacturing process and subsequent repoling. Newtonian principles are then employed to develop PDE models which quantify displacements in the actuator due to voltage inputs to the piezoceramic patch. For this analysis, drive levels are assumed to be moderate so that linear piezoelectric relations can be employed. Finite element methods for discretizing the models are developed and the performance of the discretized models are illustrated through comparison with experimental data.

  6. Material distribution in light water reactor-type bundles tested under severe accident conditions

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

    Noack, V.; Hagen, S.J.L.; Hofmann, P.

    1997-02-01

    Severe fuel damage experiments simulating small-break loss-of-coolant accidents have been carried out in the CORA out-of-pile test facility at Forschungszentrum Karlsruhe. Rod bundles with electrically heated fuel rod simulators containing annular UO{sub 2} pellets, UO{sub 2} full pellet rods, and absorber rods of two kinds (Ag/In/Cd to represent pressurized water reactor conditions and B{sub 4}C to represent boiling water reactor and VVER-1000 fuel elements) were subjected to temperature transients up to 2,300 K. A special method was applied to determine the axial mass distribution of bundle materials. The low-temperature melt formation by various interactions between zirconium and components of absorbermore » and spacer grids strongly influences the bundle degradation and material relocation. Absorber materials can separate from the fuel by a noncoherent relocation of the materials at different temperatures. The distributions of solidified materials in the different test bundles show a clear dependence on the axial temperature profile. Coolant channel blockages are observed mainly at the lower end of the bundle, i.e., near the lowest elevation at which an oxidation excursion resulting from the highly exothermic zirconium-steam reaction had been experienced. This elevation corresponds with a steep axial temperature gradient in the maximum temperature attained. Oxide layers on Zircaloy result in reduced melt formation.« less

  7. Urban pedestrian accident countermeasures experimental evaluation. Volume 2, Accident studies

    DOT National Transportation Integrated Search

    1975-02-01

    A pedestrian accident data collection system was established in six major cities. The system involved using the regular police accident report form and a specifically designed supplementary data form. The information on the forms was combined, and th...

  8. Terrain Classification of Norwegian Slab Avalanche Accidents

    ERIC Educational Resources Information Center

    Hallandvik, Linda; Aadland, Eivind; Vikene, Odd Lennart

    2016-01-01

    It is difficult to rely on snow conditions, weather, and human factors when making judgments about avalanche risk because these variables are dynamic and complex; terrain, however, is more easily observed and interpreted. Therefore, this study aimed to investigate (1) the type of terrain in which historical fatal snow avalanche accidents in Norway…

  9. An Evidential Reasoning-Based CREAM to Human Reliability Analysis in Maritime Accident Process.

    PubMed

    Wu, Bing; Yan, Xinping; Wang, Yang; Soares, C Guedes

    2017-10-01

    This article proposes a modified cognitive reliability and error analysis method (CREAM) for estimating the human error probability in the maritime accident process on the basis of an evidential reasoning approach. This modified CREAM is developed to precisely quantify the linguistic variables of the common performance conditions and to overcome the problem of ignoring the uncertainty caused by incomplete information in the existing CREAM models. Moreover, this article views maritime accident development from the sequential perspective, where a scenario- and barrier-based framework is proposed to describe the maritime accident process. This evidential reasoning-based CREAM approach together with the proposed accident development framework are applied to human reliability analysis of a ship capsizing accident. It will facilitate subjective human reliability analysis in different engineering systems where uncertainty exists in practice. © 2017 Society for Risk Analysis.

  10. Interim MELCOR Simulation of the Fukushima Daiichi Unit 2 Accident Reactor Core Isolation Cooling Operation

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

    Ross, Kyle W.; Gauntt, Randall O.; Cardoni, Jeffrey N.

    2013-11-01

    Data, a brief description of key boundary conditions, and results of Sandia National Laboratories’ ongoing MELCOR analysis of the Fukushima Unit 2 accident are given for the reactor core isolation cooling (RCIC) system. Important assumptions and related boundary conditions in the current analysis additional to or different than what was assumed/imposed in the work of SAND2012-6173 are identified. This work is for the U.S. Department of Energy’s Nuclear Energy University Programs fiscal year 2014 Reactor Safety Technologies Research and Development Program RC-7: RCIC Performance under Severe Accident Conditions.

  11. Numerical tools to predict the environmental loads for offshore structures under extreme weather conditions

    NASA Astrophysics Data System (ADS)

    Wu, Yanling

    2018-05-01

    In this paper, the extreme waves were generated using the open source computational fluid dynamic (CFD) tools — OpenFOAM and Waves2FOAM — using linear and nonlinear NewWave input. They were used to conduct the numerical simulation of the wave impact process. Numerical tools based on first-order (with and without stretching) and second-order NewWave are investigated. The simulation to predict force loading for the offshore platform under the extreme weather condition is implemented and compared.

  12. Surprise influences hindsight-foresight differences in temporal judgments of animated automobile accidents.

    PubMed

    Calvillo, Dustin P; Gomes, Dayna M

    2011-04-01

    The hindsight bias occurs when people view an outcome as more foreseeable than it actually was. The role of an outcome's initial surprise in the hindsight bias was examined using animations of automobile accidents. Twenty-six participants rated the initial surprise of accidents' occurring in eight animations. An additional 84 participants viewed these animations in one of two conditions: Half stopped the animations when they were certain an accident would occur (i.e., in foresight), and the other half watched the entire animations first and then stopped the animations when they thought that a naïve viewer would be certain that an accident would occur (i.e., in hindsight). When the accidents were low in initial surprise, there were no foresight-hindsight differences; when initial surprise was medium, there was a hindsight bias; and when initial surprise was high, there was a reversed hindsight bias. The results are consistent with a sense-making model of hindsight bias.

  13. Accidents on hospital wards.

    PubMed Central

    Levene, S; Bonfield, G

    1991-01-01

    Eight hospitals reported 781 non-iatrogenic accidents occurring to patients and visitors under 16 years of age during an 18 month period up to October 1989. Accidents more often involved boys and children aged 3 to 5 years old. Falls from a height, slips, and striking accidents were common by day and falls by night. A total of 41% of accidents to inpatients occurred when parents were present. Only three accidents were serious. Altogether 27% involved beds and cots, and only one consequent injury was more than minor. Data collected routinely in case of medicolegal action can be presented in a form that may facilitate preventative work. Potentially remediable causes for concern include falls from beds and cots and the use of makeshift equipment. PMID:1929510

  14. Characterising ductility of 6xxx-series aluminium sheet alloys at combined loading conditions

    NASA Astrophysics Data System (ADS)

    Henn, Philipp; Liewald, Mathias; Sindel, Manfred

    2017-10-01

    This paper presents a new approach to characterise material ductility when combined, three dimensional loading conditions occurring during vehicle crash are applied. So called "axial crush test" of closed hat sections is simplified by reducing it down to a two-dimensional testing procedure. This newly developed edge-compression test (ECT) provides the opportunity to investigate a defined characteristic axial folding behaviour of a profile edge. The potential to quantify and to differentiate crashworthiness of material by use of new edge-compression test is investigated by carrying out experimental studies with two different 6xxx-aluminium sheet alloys.

  15. Understanding factors associated with misclassification of fatigue-related accidents in police record.

    PubMed

    Li, Yanyan; Yamamoto, Toshiyuki; Zhang, Guangnan

    2018-02-01

    Fatigue is one of the riskiest causes of traffic accidents threatening road safety. Due to lack of proper criteria, the identification of fatigue-related accidents by police officers largely depends on inferential evidence and their own experience. As a result, many fatigue-related accidents are misclassified and the harmfulness of fatigue on road safety is misestimated. In this paper, a joint model framework is introduced to analyze factors contributing to misclassification of a fatigue-related accident in police reports. Association rule data mining technique is employed to identify the potential interactions of factors, and logistic regression models are applied to analyze factors that hinder police officers' identification of fatigue-related accidents. Using the fatigue-related crash records from Guangdong Province during 2005-2014, factors contributing to the false positive and false negative detection of the fatigue-related accident have been identified and compared. Some variables and interactions were identified to have significant impacts on fatigue-related accident detection. Based on the results, it can be inferred that the stereotype of certain groups of drivers, crash types, and roadway conditions affects police officers' judgment on fatigue-related accidents. This finding can provide useful information for training police officers and build better criteria for fatigue identification. Copyright © 2017 National Safety Council and Elsevier Ltd. All rights reserved.

  16. Core cooling under accident conditions at the high flux beam reactor (HFBR)

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

    Tichler, P.; Cheng, L.; Fauske, H.

    In certain accident scenarios, e.g. loss of coolant accidents (LOCA) all forced flow cooling is lost. Decay heating causes a temperature increase in the core coolant and the resulting thermal buoyancy causes a reversal of the flow direction to a natural circulation mode. Although there was experimental evidence during the reactor design period (1958--1963) that the heat removal capacity in the fully developed natural circulation cooling mode was relatively high, it was not possible to make a confident prediction of the heat removal capacity during the transition from downflow to natural circulation. In a LOCA scenario where even limited fuelmore » damage occurs and natural circulation is established, fission product gases could be carried from the damaged fuel by steam into areas where operator access is required to maintain the core in a coolable configuration. This would force evacuation of the building and lead to extensive core damage. As a result the HFBR was shut down by the Department of Energy (DOE) and an extensive review of the HFBR was initiated. In an effort to address this issue BNL developed a model designed to predict the heat removal limit during flow reversal that was found to be in good agreement with the test results. Currently a thermal-hydraulic test program is being developed to provide a more realistic and defensible estimate of the flow reversal heat removal limit so that the reactor power level can be increased.« less

  17. Less than severe worst case accidents

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

    Sanders, G.A.

    1996-08-01

    Many systems can provide tremendous benefit if operating correctly, produce only an inconvenience if they fail to operate, but have extreme consequences if they are only partially disabled such that they operate erratically or prematurely. In order to assure safety, systems are often tested against the most severe environments and accidents that are considered possible to ensure either safe operation or safe failure. However, it is often the less severe environments which result in the ``worst case accident`` since these are the conditions in which part of the system may be exposed or rendered unpredictable prior to total system failure.more » Some examples of less severe mechanical, thermal, and electrical environments which may actually be worst case are described as cautions for others in industries with high consequence operations or products.« less

  18. Carrying asymmetric loads during stair negotiation.

    PubMed

    Wang, Junsig; Gillette, Jason

    2017-03-01

    Individuals often carry items in one hand instead of both hands during activities of daily living. The combined effects of carrying asymmetric loads and stair negotiation may create even higher demands on the low back and lower extremity. The purpose of this study was to investigate the effect of symmetric and asymmetric loading conditions on L5/S1 and lower extremity moments during stair negotiation. Twenty-two college students performed stair ascent and stair descent on a three-step staircase (step height 18.5cm, tread depth 29.5cm) at preferred pace under five load conditions: no load, 10% body weight (BW) unilateral load, 20% BW unilateral load, 10% BW bilateral load, and 20% BW bilateral load. Video cameras and force platforms were used to collect kinematic and kinetic data. Inverse dynamics was used to calculate frontal plane moments for the L5/S1 and lower extremity. A 20% BW unilateral load resulted in significantly higher peak L5/S1 lateral bending, hip abduction, and external knee varus moments than nearly all other loading conditions during stair ascent and stair descent. Therefore, we suggest potential benefits when carrying symmetrical loads as compared to an asymmetric load in order to decrease the frontal joint moments, particularly at 20% BW load. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Thermodynamic evaluation of the solidification phase of molten core-concrete under estimated Fukushima Daiichi nuclear power plant accident conditions

    NASA Astrophysics Data System (ADS)

    Kitagaki, Toru; Yano, Kimihiko; Ogino, Hideki; Washiya, Tadahiro

    2017-04-01

    The solidification phases of molten core-concrete under the estimated molten core-concrete interaction (MCCI) conditions in the Fukushima Daiichi Nuclear Power Plant Unit 1 were predicted using the thermodynamic equilibrium calculation tool, FactSage 6.2, and the NUCLEA database in order to contribute toward the 1F decommissioning work and to understand the accident progression via the analytical results for the 1F MCCI products. We showed that most of the U and Zr in the molten core-concrete forms (U,Zr)O2 and (Zr,U)SiO4, and the formation of other phases with these elements is limited. However, the formation of (Zr,U)SiO4 requires a relatively long time because it involves a change in the crystal structure from fcc-(U,Zr)O2 to tet-(U,Zr)O2, followed by the formation of (Zr,U)SiO4 by reaction with SiO2. Therefore, the formation of (Zr,U)SiO4 is limited under quenching conditions. Other common phases are the oxide phases, CaAl2Si2O8, SiO2, and CaSiO3, and the metallic phases of the Fe-Si and Fe-Ni alloys. The solidification phenomenon of the crust under quenching conditions and that of the molten pool under thermodynamic equilibrium conditions in the 1F MCCI progression are discussed.

  20. Rear-end accident victims. Importance of understanding the accident.

    PubMed Central

    Sehmer, J. M.

    1993-01-01

    Family physicians regularly treat victims of rear-end vehicle accidents. This article describes how taking a detailed history of the accident and understanding the significance of the physical events is helpful in understanding and anticipating patients' morbidity and clinical course. Eight questions to ask patients are suggested to help physicians understand the severity of injury. PMID:8495140

  1. Prevention of bicycle accidents.

    PubMed

    Simpson, A H; Mineiro, J

    1992-01-01

    To elucidate the way of reducing the number of bicycle accidents. A prospective study of all casualties from bicycle accidents attending an accident unit for a 29-month period was performed (1831 patients). A more detailed questionnaire on the causes of accidents was used for the last 12 months of the study (818 patients). In the 0-7 and 8-12 years age groups, 87.5 per cent and 66.2 per cent, respectively, were due to cyclist error. The 8-12-year-old cyclists were twice as likely to have caused the accident if they had not had formal training (risk ratio = 2.0). Over the age of 18 years, 41.4 per cent were due to another road user. A motor vehicle was involved in 633 of the 1831 accidents. Children under the age of 8 years should not be allowed on public roads. Older children should only be allowed on the roads after formal training. This should become part of the school curriculum. A campaign to increase the awareness of motorists would be expected to reduce the number of cycle accidents. It would be beneficial to dedicate more roads and tracks to cycle use. Cyclists should be encouraged to wear more protective gear.

  2. X-ray scattering and spectroscopy studies on diesel soot from oxygenated fuel under various engine load conditions

    USGS Publications Warehouse

    Braun, Andreas; Shah, N.; Huggins, Frank E.; Kelly, K.E.; Sarofim, A.; Jacobsen, C.; Wirick, S.; Francis, H.; Ilavsky, J.; Thomas, G.E.; Huffman, G.P.

    2005-01-01

    Diesel soot from reference diesel fuel and oxygenated fuel under idle and load engine conditions was investigated with X-ray scattering and X-ray carbon K-edge absorption spectroscopy. Up to five characteristic size ranges were found. Idle soot was generally found to have larger primary particles and aggregates but smaller crystallites, than load soot. Load soot has a higher degree of crystallinity than idle soot. Adding oxygenates to diesel fuel enhanced differences in the characteristics of diesel soot, or even reversed them. Aromaticity of idle soot from oxygenated diesel fuel was significantly larger than from the corresponding load soot. Carbon near-edge X-ray absorption fine structure (NEXAFS) spectroscopy was applied to gather information about the presence of relative amounts of carbon double bonds (CC, CO) and carbon single bonds (C-H, C-OH, COOH). Using scanning X-ray transmission microspectroscopy (STXM), the relative amounts of these carbon bond states were shown to vary spatially over distances approximately 50 to 100 nm. The results from the X-ray techniques are supported by thermo-gravimetry analysis and high-resolution transmission electron microscopy. ?? 2005 Elsevier Ltd. All rights reserved.

  3. Accident data availability

    DOT National Transportation Integrated Search

    2000-06-01

    This project investigates alternate forms of dissemination for the accident information. Costs, capabilities, and compatibility are reviewed for integration of the accident database with a GIS format to allow a graphical and spatial interface. the is...

  4. Occupant Injury Severity and Accident Causes in Helicopter Emergency Medical Services (1983-2014).

    PubMed

    Boyd, Douglas D; Macchiarella, Nickolas D

    2016-01-01

    Helicopter emergency medical services (HEMS) transport critically ill patients to/between emergency care facilities and operate in a hazardous environment: the destination site is often encumbered with obstacles, difficult to visualize at night, and lack instrument approaches for degraded visibility. The study objectives were to determine 1) HEMS accident rates and causes; 2) occupant injury severity profiles; and 3) whether accident aircraft were certified to the more stringent crashworthiness standards implemented two decades ago. The National Transportation Safety Board (NTSB) aviation accident database was used to identify HEMS mishaps for the years spanning 1983-2014. Contingency tables (Pearson Chi-square or Fisher's exact test) were used to determine differences in proportions. A generalized linear model (Poisson distribution) was used to determine if accident rates differed over time. While the HEMS accident rate decreased by 71% across the study period, the fraction of fatal accidents (36-50%) and the injury severity profiles were unchanged. None of the accident aircraft fully satisfied the current crashworthiness standards. Failure to clear obstacles and visual-to-instrument flight, the most frequent accident causes (37 and 26%, respectively), showed a downward trend, whereas accidents ascribed to aircraft malfunction showed an upward trend over time. HEMS operators should consider updating their fleet to the current, more stringent crashworthiness standards in an attempt to reduce injury severity. Additionally, toward further mitigating accidents ascribed to inadvertent visual-to-instrument conditions, HEMS aircraft should be avionics-equipped for instrument flight rules flight.

  5. Mechanical Properties of a Unidirectional Basalt-Fiber-Reinforced Plastic Under a Loading Simulating Operation Conditions

    NASA Astrophysics Data System (ADS)

    Lobanov, D. S.; Slovikov, S. V.

    2017-01-01

    The results of experimental investigations of unidirectional composites based on basalt fibers and different marks of epoxy resins are presented. Uniaxial tensile tests were carried out using a specimen fixation technique simulating the operation conditions of structures. The mechanical properties of the basalt-fiber-reinforced plastics (BFRPs) were determined. The diagrams of loading and deformation of BFRP specimens were obtain. The formulations of the composites with the highest mechanical properties were revealed.

  6. [Work-related accidents on oil drilling platforms in the Campos Basin, Rio de Janeiro, Brazil].

    PubMed

    Freitas, C M; Souza, C A; Machado, J M; Porto, M F

    2001-01-01

    The offshore oil industry is characterized by complex systems in relation to technology and organization of work. Working conditions are hazardous, resulting in accidents and even occasional full-scale catastrophes. This article is the result of a study on work-related accidents in the offshore platforms in the Campos Basin, Rio de Janeiro State. The primary objective was to provide technical back-up for both workers' representative organizations and public authorities. As a methodology, we attempt to go beyond the immediate causes of accidents and emphasize underlying causes related to organizational and managerial aspects. The sources were used in such a way as to permit classification in relation to the type of incident, technological system, operation, and immediate and underlying causes. The results show the aggravation of safety conditions and the immediate need for public authorities and the offshore oil industry in Brazil to change the methods used to investigate accidents in order to identify the main causes in the organizational and managerial structure of companies.

  7. Toxicological findings in 889 fatally injured obese pilots involved in aviation accidents.

    PubMed

    Chaturvedi, Arvind K; Botch, Sabra R; Ricaurte, Eduard M

    2012-03-01

    Prevalence of drugs in fatally injured obese pilots involved in aviation accidents has not been evaluated. Therefore, toxicological findings in such pilots (body mass index ≥30 kg/m(2) ) were examined in a data set derived from the Civil Aerospace Medical Institute's (CAMI's) Scientific Information System for 1990-2005. Aeromedical histories of these aviators were retrieved from the CAMI medical certification and toxicology databases, and the cause/factors in the related accidents from the National Transportation Safety Board's database. In 311 of the 889 pilots, carbon monoxide, cyanide, ethanol, and drugs were found, and glucose and hemoglobin A(1c) were elevated. Of the 889 pilots, 107 had an obesity-related medical history. The health and/or medical condition(s) of, and/or the use of ethanol and/or drugs by, pilots were the cause/factors in 55 (18%) of the 311 accidents. Drugs found were primarily for treating obesity-related medical conditions such as depression, hypertension, and coronary heart disease. 2011 American Academy of Forensic Sciences. Published 2011. This article is a U.S. Government work and is in the public domain in the U.S.A.

  8. Fatal occupational accidents in Danish fishing vessels 1989-2005.

    PubMed

    Laursen, Lise H; Hansen, Henrik L; Jensen, Olaf C

    2008-06-01

    The purpose of the study was to study the circumstances and incidence rates of fatal accidents in inspection obligated and non-inspection obligated Danish fishing vessels to identify areas for prevention. Information about the fatalities came from maritime authority reports, including vessel disaster reports, post mortem reports, maritime inquiries and police reports. The person- and vessel years at risk came from the Danish Directorate of Fisheries. During the period 1989-2005, 114 fatalities occurred. Sixty-one of the fatalities occurred in 36 vessel disasters mainly caused by foundering/capsizing due to stability changes in rough weather and collisions; 39 fatal occupational accidents mainly occurred on the larger inspection obligated trawlers during fishing. In the remaining 14 other fatal accidents, the main causal factors were difficult embarking/disembarking conditions by darkness in foreign ports and alcohol intoxication. In the period 1995-2005, the overall incidence rate was 10 per 10,000 fishermen per year with no down-going trend during that period. The fatal accident rates are still too high, despite the efforts to reduce the risk. Increased focus on regular and repeated safety training for all fishermen and improved safety measures are needed, especially in the underscored areas of sea disasters concerning small vessels and occupational accidents on big vessels. Better registration of time at risk for fishermen is needed to validate the effect of the safety measures.

  9. Severe Accident Scoping Simulations of Accident Tolerant Fuel Concepts for BWRs

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

    Robb, Kevin R.

    2015-08-01

    Accident-tolerant fuels (ATFs) are fuels and/or cladding that, in comparison with the standard uranium dioxide Zircaloy system, can tolerate loss of active cooling in the core for a considerably longer time period while maintaining or improving the fuel performance during normal operations [1]. It is important to note that the currently used uranium dioxide Zircaloy fuel system tolerates design basis accidents (and anticipated operational occurrences and normal operation) as prescribed by the US Nuclear Regulatory Commission. Previously, preliminary simulations of the plant response have been performed under a range of accident scenarios using various ATF cladding concepts and fully ceramicmore » microencapsulated fuel. Design basis loss of coolant accidents (LOCAs) and station blackout (SBO) severe accidents were analyzed at Oak Ridge National Laboratory (ORNL) for boiling water reactors (BWRs) [2]. Researchers have investigated the effects of thermal conductivity on design basis accidents [3], investigated silicon carbide (SiC) cladding [4], as well as the effects of ATF concepts on the late stage accident progression [5]. These preliminary analyses were performed to provide initial insight into the possible improvements that ATF concepts could provide and to identify issues with respect to modeling ATF concepts. More recently, preliminary analyses for a range of ATF concepts have been evaluated internationally for LOCA and severe accident scenarios for the Chinese CPR1000 [6] and the South Korean OPR-1000 [7] pressurized water reactors (PWRs). In addition to these scoping studies, a common methodology and set of performance metrics were developed to compare and support prioritizing ATF concepts [8]. A proposed ATF concept is based on iron-chromium-aluminum alloys (FeCrAl) [9]. With respect to enhancing accident tolerance, FeCrAl alloys have substantially slower oxidation kinetics compared to the zirconium alloys typically employed. During a severe accident, Fe

  10. Applying STAMP in Accident Analysis

    NASA Technical Reports Server (NTRS)

    Leveson, Nancy; Daouk, Mirna; Dulac, Nicolas; Marais, Karen

    2003-01-01

    Accident models play a critical role in accident investigation and analysis. Most traditional models are based on an underlying chain of events. These models, however, have serious limitations when used for complex, socio-technical systems. Previously, Leveson proposed a new accident model (STAMP) based on system theory. In STAMP, the basic concept is not an event but a constraint. This paper shows how STAMP can be applied to accident analysis using three different views or models of the accident process and proposes a notation for describing this process.

  11. United States Department of Energy severe accident research following the Fukushima Daiichi accidents

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

    Farmer, M. T.; Corradini, M.; Rempe, J.

    The U.S. Department of Energy (DOE) has played a major role in the U.S. response to the events at Fukushima Daiichi. During the first several weeks following the accident, U.S. assistance efforts were guided by results from a significant and diverse set of analyses. In the months that followed, a coordinated analysis activity aimed at gaining a more thorough understanding of the accident sequence was completed using laboratory-developed, system-level best-estimate accident analysis codes, while a parallel analysis was conducted by U.S. industry. A comparison of predictions for Unit 1 from these two studies indicated significant differences between MAAP and MELCORmore » results for key plant parameters, such as in-core hydrogen production. On that basis, a crosswalk was completed to determine the key modeling variations that led to these differences. In parallel with these activities, it became clear that there was a need to perform a technology gap evaluation on accident-tolerant components and severe accident analysis methodologies with the goal of identifying any data and/or knowledge gaps that may exist given the current state of light water reactor (LWR) severe accident research and augmented by insights from Fukushima. In addition, there is growing international recognition that data from Fukushima could significantly reduce uncertainties related to severe accident progression, particularly for boiling water reactors. On these bases, a group of U. S. experts in LWR safety and plant operations was convened by the DOE Office of Nuclear Energy (DOE-NE) to complete technology gap analysis and Fukushima forensics data needs identification activities. The results from these activities were used as the basis for refining DOE-NE's severe accident research and development (R&D) plan. Finally, this paper provides a high-level review of DOE-sponsored R&D efforts in these areas, including planned activities on accident-tolerant components and accident analysis methods.« less

  12. United States Department of Energy severe accident research following the Fukushima Daiichi accidents

    DOE PAGES

    Farmer, M. T.; Corradini, M.; Rempe, J.; ...

    2016-11-02

    The U.S. Department of Energy (DOE) has played a major role in the U.S. response to the events at Fukushima Daiichi. During the first several weeks following the accident, U.S. assistance efforts were guided by results from a significant and diverse set of analyses. In the months that followed, a coordinated analysis activity aimed at gaining a more thorough understanding of the accident sequence was completed using laboratory-developed, system-level best-estimate accident analysis codes, while a parallel analysis was conducted by U.S. industry. A comparison of predictions for Unit 1 from these two studies indicated significant differences between MAAP and MELCORmore » results for key plant parameters, such as in-core hydrogen production. On that basis, a crosswalk was completed to determine the key modeling variations that led to these differences. In parallel with these activities, it became clear that there was a need to perform a technology gap evaluation on accident-tolerant components and severe accident analysis methodologies with the goal of identifying any data and/or knowledge gaps that may exist given the current state of light water reactor (LWR) severe accident research and augmented by insights from Fukushima. In addition, there is growing international recognition that data from Fukushima could significantly reduce uncertainties related to severe accident progression, particularly for boiling water reactors. On these bases, a group of U. S. experts in LWR safety and plant operations was convened by the DOE Office of Nuclear Energy (DOE-NE) to complete technology gap analysis and Fukushima forensics data needs identification activities. The results from these activities were used as the basis for refining DOE-NE's severe accident research and development (R&D) plan. Finally, this paper provides a high-level review of DOE-sponsored R&D efforts in these areas, including planned activities on accident-tolerant components and accident analysis methods.« less

  13. Blinded by the load: attention, awareness and the role of perceptual load

    PubMed Central

    Lavie, Nilli; Beck, Diane M.; Konstantinou, Nikos

    2014-01-01

    What is the relationship between attention and conscious awareness? Awareness sometimes appears to be restricted to the contents of focused attention, yet at other times irrelevant distractors will dominate awareness. This contradictory relationship has also been reflected in an abundance of discrepant research findings leading to an enduring controversy in cognitive psychology. Lavie's load theory of attention suggests that the puzzle can be solved by considering the role of perceptual load. Although distractors will intrude upon awareness in conditions of low load, awareness will be restricted to the content of focused attention when the attended information involves high perceptual load. Here, we review recent evidence for this proposal with an emphasis on the various subjective blindness phenomena, and their neural correlates, induced by conditions of high perceptual load. We also present novel findings that clarify the role of attention in the response to stimulus contrast. Overall, this article demonstrates a critical role for perceptual load across the spectrum of perceptual processes leading to awareness, from the very early sensory responses related to contrast detection to explicit recognition of semantic content. PMID:24639578

  14. Blinded by the load: attention, awareness and the role of perceptual load.

    PubMed

    Lavie, Nilli; Beck, Diane M; Konstantinou, Nikos

    2014-05-05

    What is the relationship between attention and conscious awareness? Awareness sometimes appears to be restricted to the contents of focused attention, yet at other times irrelevant distractors will dominate awareness. This contradictory relationship has also been reflected in an abundance of discrepant research findings leading to an enduring controversy in cognitive psychology. Lavie's load theory of attention suggests that the puzzle can be solved by considering the role of perceptual load. Although distractors will intrude upon awareness in conditions of low load, awareness will be restricted to the content of focused attention when the attended information involves high perceptual load. Here, we review recent evidence for this proposal with an emphasis on the various subjective blindness phenomena, and their neural correlates, induced by conditions of high perceptual load. We also present novel findings that clarify the role of attention in the response to stimulus contrast. Overall, this article demonstrates a critical role for perceptual load across the spectrum of perceptual processes leading to awareness, from the very early sensory responses related to contrast detection to explicit recognition of semantic content.

  15. The mechanical response of a polyetheretherketone femoral knee implant under a deep squatting loading condition.

    PubMed

    de Ruiter, Lennert; Janssen, Dennis; Briscoe, Adam; Verdonschot, Nico

    2017-12-01

    The current study was designed to investigate the mechanical response of a polyetheretherketone-on-polyethylene total knee replacement device during a deep squat. Application of this high-demand loading condition can identify weaknesses of the polyetheretherketone relative to cobalt-chromium. This study investigated whether the implant is strong enough for this type of loading, whether cement stresses are considerably changed and whether a polyetheretherketone femoral component is likely to lead to reduced periprosthetic bone loss as compared to a cobalt-chromium component. A finite element model of a total knee arthroplasty subjected to a deep squat loading condition, which was previously published, was adapted with an alternative total knee arthroplasty design made of either polyetheretherketone or cobalt-chromium. The maximum tensile and compressive stresses within the implant and cement mantle were analysed against their yield and fatigue stress levels. The amount of stress shielding within the bone was compared between the polyetheretherketone and cobalt-chromium cases. Relative to its material strength, tensile peak stresses were higher in the cobalt-chromium implant; compressive peak stresses were higher in the polyetheretherketone implant. The stress patterns differed substantially between polyetheretherketone and cobalt-chromium. The tensile stresses in the cement mantle supporting the polyetheretherketone implant were up to 33% lower than with the cobalt-chromium component, but twice as high for compression. Stress shielding was reduced to a median of 1% for the polyetheretherketone implant versus 56% for the cobalt-chromium implant. Both the polyetheretherketone implant and the underlying cement mantle should be able to cope with the stress levels present during a deep squat. Relative to the cobalt-chromium component, stress shielding of the periprosthetic femur was substantially less with a polyetheretherketone femoral component.

  16. An insight into the maritime accident characteristics in Bangladesh

    NASA Astrophysics Data System (ADS)

    Uddin, Md. Imran; Awal, Zobair Ibn

    2017-12-01

    The inland waterway plays a very important role in the transportation system of Bangladesh. But, due to severe deficiencies of the safety practices, a lot of accidentll take place almost every year in the inland waterways that cause considerable loss of human lives and assets. The inland waterway accidentll in Bangladasb during 2005 to 2015 were analysed statistically in the present study. It has been found that the leading mode of accidents is collision among vessels and fatal injury comprises considerably a higher proportion of total casnalties. The study also revealed that cargo vessels and passenger vessels encounter more accidents in comparison to other types of vessels. It was also observed that during fair weather and good visibility condition significant proportion of accidents have taken place. Based on this study several recommendstions bsve been put forward for improving ssfety in the inlsnd waterways ofBanglsdesh.

  17. Prediction of road accidents: A Bayesian hierarchical approach.

    PubMed

    Deublein, Markus; Schubert, Matthias; Adey, Bryan T; Köhler, Jochen; Faber, Michael H

    2013-03-01

    In this paper a novel methodology for the prediction of the occurrence of road accidents is presented. The methodology utilizes a combination of three statistical methods: (1) gamma-updating of the occurrence rates of injury accidents and injured road users, (2) hierarchical multivariate Poisson-lognormal regression analysis taking into account correlations amongst multiple dependent model response variables and effects of discrete accident count data e.g. over-dispersion, and (3) Bayesian inference algorithms, which are applied by means of data mining techniques supported by Bayesian Probabilistic Networks in order to represent non-linearity between risk indicating and model response variables, as well as different types of uncertainties which might be present in the development of the specific models. Prior Bayesian Probabilistic Networks are first established by means of multivariate regression analysis of the observed frequencies of the model response variables, e.g. the occurrence of an accident, and observed values of the risk indicating variables, e.g. degree of road curvature. Subsequently, parameter learning is done using updating algorithms, to determine the posterior predictive probability distributions of the model response variables, conditional on the values of the risk indicating variables. The methodology is illustrated through a case study using data of the Austrian rural motorway network. In the case study, on randomly selected road segments the methodology is used to produce a model to predict the expected number of accidents in which an injury has occurred and the expected number of light, severe and fatally injured road users. Additionally, the methodology is used for geo-referenced identification of road sections with increased occurrence probabilities of injury accident events on a road link between two Austrian cities. It is shown that the proposed methodology can be used to develop models to estimate the occurrence of road accidents for any

  18. [Accidents with the "paraglider"].

    PubMed

    Lang, T H; Dengg, C; Gabl, M

    1988-09-01

    With a collective of 46 patients we show the details and kinds of accidents caused by paragliding. The base for the casuistry of the accidents was a questionnaire which was answered by most of the injured persons. These were questions about the theoretical and practical training, the course of the flight during the different phases, and the subjective point of view of the course of the accident. The patterns of the injuries showed a high incidence of injuries of the spinal column and high risks for the ankles. At the end, we give some advice how to prevent these accidents.

  19. Heat up and potential failure of BWR upper internals during a severe accident

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

    Robb, Kevin R

    2015-01-01

    In boiling water reactors, the steam dome, steam separators, and dryers above the core are comprised of approximately 100 tons of stainless steel. During a severe accident in which the coolant boils away and exothermic oxidation of zirconium occurs, gases (steam and hydrogen) are superheated in the core region and pass through the upper internals. Historically, the upper internals have been modeled using severe accident codes with relatively simple approximations. The upper internals are typically modeled in MELCOR as two lumped volumes with simplified heat transfer characteristics, with no structural integrity considerations, and with limited ability to oxidize, melt, andmore » relocate. The potential for and the subsequent impact of the upper internals to heat up, oxidize, fail, and relocate during a severe accident was investigated. A higher fidelity representation of the shroud dome, steam separators, and steam driers was developed in MELCOR v1.8.6 by extending the core region upwards. This modeling effort entailed adding 45 additional core cells and control volumes, 98 flow paths, and numerous control functions. The model accounts for the mechanical loading and structural integrity, oxidation, melting, flow area blockage, and relocation of the various components. The results indicate that the upper internals can reach high temperatures during a severe accident; they are predicted to reach a high enough temperature such that they lose their structural integrity and relocate. The additional 100 tons of stainless steel debris influences the subsequent in-vessel and ex-vessel accident progression.« less

  20. The effects of aircraft certification rules on general aviation accidents

    NASA Astrophysics Data System (ADS)

    Anderson, Carolina Lenz

    -Square test indicated that there was no significant difference in the number of accidents among the different certification categories when either Controlled Flight into Terrain or Structural Failure was listed as cause. However, there was a significant difference in the frequency of accidents with regard to Loss of Control and Engine Failure accidents. The results of the ANCOVA test indicated that there was no significant difference in the accident rate with regard to Loss of Control, Controlled Flight into Terrain, or Structural Failure accidents. There was, however, a significant difference in Engine Failure accidents between Experimental-Amateur Built and the other categories.The text mining analysis of the narrative causes of Loss of Control accidents indicated that only the Civil Air Regulations 3 category airplanes had clusters of words associated with visual flight into instrument meteorological conditions. Civil Air Regulations 3 airplanes were designed and manufactured prior to the 1960s and in most cases have not been retrofitted to take advantage of newer technologies that could help prevent Loss of Control accidents. The study indicated that General Aviation aircraft certification rules do not have a statistically significant effect on aircraft accidents except for Loss of Control and Engine Failure. According to the literature, government oversight could have become an obstacle in the implementation of safety enhancing equipment that could reduce Loss of Control accidents. Oversight should focus on ensuring that Experimental-Amateur Built aircraft owners perform a functional test that could prevent some of the Engine Failure accidents.

  1. Preliminary Analysis of Aircraft Loss of Control Accidents: Worst Case Precursor Combinations and Temporal Sequencing

    NASA Technical Reports Server (NTRS)

    Belcastro, Christine M.; Groff, Loren; Newman, Richard L.; Foster, John V.; Crider, Dennis H.; Klyde, David H.; Huston, A. McCall

    2014-01-01

    Aircraft loss of control (LOC) is a leading cause of fatal accidents across all transport airplane and operational classes, and can result from a wide spectrum of hazards, often occurring in combination. Technologies developed for LOC prevention and recovery must therefore be effective under a wide variety of conditions and uncertainties, including multiple hazards, and their validation must provide a means of assessing system effectiveness and coverage of these hazards. This requires the definition of a comprehensive set of LOC test scenarios based on accident and incident data as well as future risks. This paper defines a comprehensive set of accidents and incidents over a recent 15 year period, and presents preliminary analysis results to identify worst-case combinations of causal and contributing factors (i.e., accident precursors) and how they sequence in time. Such analyses can provide insight in developing effective solutions for LOC, and form the basis for developing test scenarios that can be used in evaluating them. Preliminary findings based on the results of this paper indicate that system failures or malfunctions, crew actions or inactions, vehicle impairment conditions, and vehicle upsets contributed the most to accidents and fatalities, followed by inclement weather or atmospheric disturbances and poor visibility. Follow-on research will include finalizing the analysis through a team consensus process, defining future risks, and developing a comprehensive set of test scenarios with correlation to the accidents, incidents, and future risks. Since enhanced engineering simulations are required for batch and piloted evaluations under realistic LOC precursor conditions, these test scenarios can also serve as a high-level requirement for defining the engineering simulation enhancements needed for generating them.

  2. [Accidents in travellers - the hidden epidemic].

    PubMed

    Walz, Alexander; Hatz, Christoph

    2013-06-01

    The risk of malaria and other communicable diseases is well addressed in pre-travel advice. Accidents are usually less discussed. Thus, we aimed at assessing accident figures for the Swiss population, based on data of the register from 2004 to 2008 of the largest Swiss accident insurance organization (SUVA). More than 139'000 accidents over 5 years showed that 65 % of the accidents overseas are injuries, and 24 % are caused by poisoning or harm by cold, heat or air pressure. Most accidents happened during leisure activities or sports. More than one third of the non-lethal and more than 50 % of the fatal accidents happened in Asia. More than three-quarters of non-lethal accidents take place in people between 25 and 54 years. One out of 74 insured persons has an accident abroad per year. Despite of many analysis short-comings of the data set with regard to overseas travel, the figures document the underestimated burden of disease caused by accidents abroad and should affect the given pre-health advice.

  3. Behaviour of wrapped cold-formed steel columns under different loading conditions

    NASA Astrophysics Data System (ADS)

    Baabu, B. Hari; Sreenath, S.

    2017-07-01

    The use of Cold Formed Steel (CFS) sections as structural members is widely accepted because of its light nature. However, the load carrying capacity of these sections will be less compared to hot rolled sections. This study is meant to analyze the possibility of strengthening cold formed members by wrapping it with Glass Fiber Reinforced Polymer (GFRP) laminates. Light gauge steel columns of cross sectional dimensions 100mm x 50mm x 3.15mm were taken for this study. The effective length of the section is about 750mm. A total of 8 specimens including the control specimen is tested under axial and eccentric loading. The columns were tested keeping both ends hinged. For both loading cases the buckling behaviour, ultimate load carrying capacity and load-deflection characteristics of the CFS columns were analyzed. The GFRP laminates were wrapped on columns in three different ways such that wrapping the outer surface of web and flange throughout the length of specimen, wrapping the outer surface of web alone throughout the length of specimen and wrapping the outer surface of web and flange for the upper half length of the specimen where the buckling is expected. For both loading cases, the results indicated that the column with wrapping at the outer surface of web and flange throughout the length of specimen provides better strength for it.

  4. Model predictions of wind and turbulence profiles associated with an ensemble of aircraft accidents

    NASA Technical Reports Server (NTRS)

    Williamson, G. G.; Lewellen, W. S.; Teske, M. E.

    1977-01-01

    The feasibility of predicting conditions under which wind/turbulence environments hazardous to aviation operations exist is studied by examining a number of different accidents in detail. A model of turbulent flow in the atmospheric boundary layer is used to reconstruct wind and turbulence profiles which may have existed at low altitudes at the time of the accidents. The predictions are consistent with available flight recorder data, but neither the input boundary conditions nor the flight recorder observations are sufficiently precise for these studies to be interpreted as verification tests of the model predictions.

  5. Effects of injection parameters, boost, and swirl ratio on gasoline compression ignition operation at idle and low-load conditions

    DOE PAGES

    Kodavasal, Janardhan; Kolodziej, Christopher P.; Ciatti, Stephen A.; ...

    2016-11-03

    In this study, we study the effects of injector nozzle inclusion angle, injection pressure, boost, and swirl ratio on gasoline compression ignition combustion. Closed-cycle computational fluid dynamics simulations using a 1/7th sector mesh representing a single cylinder of a four-cylinder 1.9 L diesel engine, operated in gasoline compression ignition mode with 87 anti-knock index (AKI) gasoline, were performed. Two different operating conditions were studied—the first is representative of idle operation (4 mg fuel/cylinder/cycle, 850 r/min), and the second is representative of a low-load condition (10 mg fuel/cylinder/cycle, 1500 r/min). The mixture preparation and reaction space from the simulations were analyzedmore » to gain insights into the effects of injection pressure, nozzle inclusion angle, boost, and swirl ratio on achieving stable low-load to idle gasoline compression ignition operation. It was found that narrower nozzle inclusion angles allow for more reactivity or propensity to ignition (determined qualitatively by computing constant volume ignition delays) and are suitable over a wider range of injection timings. Under idle conditions, it was found that lower injection pressures helped to reduce overmixing of the fuel, resulting in greater reactivity and ignitability (ease with which ignition can be achieved) of the gasoline. However, under the low-load condition, lower injection pressures did not increase ignitability, and it is hypothesized that this is because of reduced chemical residence time resulting from longer injection durations. Reduced swirl was found to maintain higher in-cylinder temperatures through compression, resulting in better ignitability. It was found that boosting the charge also helped to increase reactivity and advanced ignition timing.« less

  6. Effects of injection parameters, boost, and swirl ratio on gasoline compression ignition operation at idle and low-load conditions

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

    Kodavasal, Janardhan; Kolodziej, Christopher P.; Ciatti, Stephen A.

    In this study, we study the effects of injector nozzle inclusion angle, injection pressure, boost, and swirl ratio on gasoline compression ignition combustion. Closed-cycle computational fluid dynamics simulations using a 1/7th sector mesh representing a single cylinder of a four-cylinder 1.9 L diesel engine, operated in gasoline compression ignition mode with 87 anti-knock index (AKI) gasoline, were performed. Two different operating conditions were studied—the first is representative of idle operation (4 mg fuel/cylinder/cycle, 850 r/min), and the second is representative of a low-load condition (10 mg fuel/cylinder/cycle, 1500 r/min). The mixture preparation and reaction space from the simulations were analyzedmore » to gain insights into the effects of injection pressure, nozzle inclusion angle, boost, and swirl ratio on achieving stable low-load to idle gasoline compression ignition operation. It was found that narrower nozzle inclusion angles allow for more reactivity or propensity to ignition (determined qualitatively by computing constant volume ignition delays) and are suitable over a wider range of injection timings. Under idle conditions, it was found that lower injection pressures helped to reduce overmixing of the fuel, resulting in greater reactivity and ignitability (ease with which ignition can be achieved) of the gasoline. However, under the low-load condition, lower injection pressures did not increase ignitability, and it is hypothesized that this is because of reduced chemical residence time resulting from longer injection durations. Reduced swirl was found to maintain higher in-cylinder temperatures through compression, resulting in better ignitability. It was found that boosting the charge also helped to increase reactivity and advanced ignition timing.« less

  7. Thermal–mechanical stress analysis of pressurized water reactor pressure vessel with/without a preexisting crack under grid load following conditions

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

    Mohanty, Subhasish; Soppet, William K.; Majumdar, Saurin

    In this paper, we present thermal-mechanical stress analysis of a pressurized water reactor pressure vessel and its hot-leg and cold-leg nozzles. Results are presented from thermal and thermal-mechanical stress analysis under reactor heat-up, cool-down, and grid load-following conditions. Analysis results are given with and without the presence of preexisting crack in the reactor nozzle (axial crack in hot leg nozzle). From the model results it is found that the stress-strain states are significantly higher in case of presence of crack than without crack. In conclusion, the stress-strain state under grid load following condition are more realistic compared to the stress-strainmore » state estimated assuming simplified transients.« less

  8. Thermal–mechanical stress analysis of pressurized water reactor pressure vessel with/without a preexisting crack under grid load following conditions

    DOE PAGES

    Mohanty, Subhasish; Soppet, William K.; Majumdar, Saurin; ...

    2016-10-26

    In this paper, we present thermal-mechanical stress analysis of a pressurized water reactor pressure vessel and its hot-leg and cold-leg nozzles. Results are presented from thermal and thermal-mechanical stress analysis under reactor heat-up, cool-down, and grid load-following conditions. Analysis results are given with and without the presence of preexisting crack in the reactor nozzle (axial crack in hot leg nozzle). From the model results it is found that the stress-strain states are significantly higher in case of presence of crack than without crack. In conclusion, the stress-strain state under grid load following condition are more realistic compared to the stress-strainmore » state estimated assuming simplified transients.« less

  9. Aircraft accidents : method of analysis

    NASA Technical Reports Server (NTRS)

    1931-01-01

    The revised report includes the chart for the analysis of aircraft accidents, combining consideration of the immediate causes, underlying causes, and results of accidents, as prepared by the special committee, with a number of the definitions clarified. A brief statement of the organization and work of the special committee and of the Committee on Aircraft Accidents; and statistical tables giving a comparison of the types of accidents and causes of accidents in the military services on the one hand and in civil aviation on the other, together with explanations of some of the important differences noted in these tables.

  10. Connecticut traffic accident facts, 2006

    DOT National Transportation Integrated Search

    2008-04-01

    This report documents facts on reported 2006 traffic accidents included in the : Department database. Sections of the report contain statistics on major categories of traffic : accidents. These categories include all reported accidents, reported alco...

  11. A study on industrial accident rate forecasting and program development of estimated zero accident time in Korea.

    PubMed

    Kim, Tae-gu; Kang, Young-sig; Lee, Hyung-won

    2011-01-01

    To begin a zero accident campaign for industry, the first thing is to estimate the industrial accident rate and the zero accident time systematically. This paper considers the social and technical change of the business environment after beginning the zero accident campaign through quantitative time series analysis methods. These methods include sum of squared errors (SSE), regression analysis method (RAM), exponential smoothing method (ESM), double exponential smoothing method (DESM), auto-regressive integrated moving average (ARIMA) model, and the proposed analytic function method (AFM). The program is developed to estimate the accident rate, zero accident time and achievement probability of an efficient industrial environment. In this paper, MFC (Microsoft Foundation Class) software of Visual Studio 2008 was used to develop a zero accident program. The results of this paper will provide major information for industrial accident prevention and be an important part of stimulating the zero accident campaign within all industrial environments.

  12. Encopresis: Not just an accident.

    PubMed

    Mosca, Nancy W; Schatz, Mary L

    2013-09-01

    Encopresis is a medical condition that can be seen in the school setting with children of all ages, though primarily at the early childhood and elementary level. This condition can cause a great amount of frustration with the student, family, and teachers due to the child's inability to control elimination patterns. The school nurse must be aware of the warning signs that a student may be experiencing encopresis in order to promote treatment. This article will assist the school nurse in understanding typical causes for functional encopresis, knowing how to help a student who soils, and developing an individualized healthcare plan that assists a student to become continent of stool again. Encopresis is not just an accident.

  13. [Accidents and violence in childhood and adolescence: risk and protective factors].

    PubMed

    Martins, Christine Baccarat de Godoy

    2013-01-01

    Singled out by statistics as the third leading cause of mortality in our country, external causes (accidents and violence) entail a great impact with economic, social and emotional rebound. Knowing the factors related to the event is essential, because it allows identifying and breaking the web that determines morbidity and mortality from external causes. The study aims to analyze the existing publications on the factors associated with accidents and violence, in order to provide theoretical support for professionals in their practices. This is a bibliographical study of the Liliacs, Medline and Scielo databanks. The knowledge of the risk and protection factors discussed in the present study enables subsidize the practice of social actors engaged in transforming the conditions that lead to accidents and violence.

  14. Accident Report: Pupils -- Employees, School Jurisdiction, 1972-1973.

    ERIC Educational Resources Information Center

    O'Hara, James M., Comp.; Conklin, Robert L., Comp.

    This report is intended to provide principals, department heads, teachers, and parents with specific information designed to assist them in isolating unsafe conditions, activities, and behavioral problems. The document is divided into three parts: (1) a pupil section, with tables showing where accidents occurred, what parts of the body were…

  15. New Technologies for Reducing Aviation Weather-Related Accidents

    NASA Technical Reports Server (NTRS)

    Stough, H. Paul, III; Watson, James F., III; Jarrell, Michael A.

    2006-01-01

    The National Aeronautics and Space Administration (NASA) has developed technologies to reduce aviation weather-related accidents. New technologies are presented for data-link and display of weather information to aircraft in flight, for detection of turbulence ahead of aircraft in flight, and for automated insitu reporting of atmospheric conditions from aircraft.

  16. Traffic accidents involving fatigue driving and their extent of casualties.

    PubMed

    Zhang, Guangnan; Yau, Kelvin K W; Zhang, Xun; Li, Yanyan

    2016-02-01

    The rapid progress of motorization has increased the number of traffic-related casualties. Although fatigue driving is a major cause of traffic accidents, the public remains not rather aware of its potential harmfulness. Fatigue driving has been termed as a "silent killer." Thus, a thorough study of traffic accidents and the risk factors associated with fatigue-related casualties is of utmost importance. In this study, we analyze traffic accident data for the period 2006-2010 in Guangdong Province, China. The study data were extracted from the traffic accident database of China's Public Security Department. A logistic regression model is used to assess the effect of driver characteristics, type of vehicles, road conditions, and environmental factors on fatigue-related traffic accident occurrence and severity. On the one hand, male drivers, trucks, driving during midnight to dawn, and morning rush hours are identified as risk factors of fatigue-related crashes but do not necessarily result in severe casualties. Driving at night without street-lights contributes to fatigue-related crashes and severe casualties. On the other hand, while factors such as less experienced drivers, unsafe vehicle status, slippery roads, driving at night with street-lights, and weekends do not have significant effect on fatigue-related crashes, yet accidents associated with these factors are likely to have severe casualties. The empirical results of the present study have important policy implications on the reduction of fatigue-related crashes as well as their severity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Determination of chemical-constituent loads during base-flow and storm-runoff conditions near historical mines in Prospect Gulch, upper Animas River watershed, southwestern Colorado

    USGS Publications Warehouse

    Wirt, Laurie; Leib, K.J.; Bove, D.J.; Mast, M.A.; Evans, J.B.; Meeker, G.P.

    1999-01-01

    Prospect Gulch is a major source of iron, aluminum, zinc, and other metals to Cement Creek. Information is needed to prioritize remediation and develop strategies for cleanup of historical abandoned mine sites in Prospect Gulch. Chemical-constituent loads were determined in Prospect Gulch, a high-elevation alpine stream in southwestern Colorado that is affected by natural acid drainage from weathering of hydro-thermally altered igneous rock and acidic metal-laden discharge from historical abandoned mines. The objective of the study was to identify metal sources to Prospect Gulch. A tracer solution was injected into Prospect Gulch during water-quality sampling so that loading of geochemical constituents could be calculated throughout the study reach. A thunderstorm occurred during the tracer study, hence, metal loads were measured for storm-runoff as well as for base flow. Data from different parts of the study reach represents different flow conditions. The beginning of the reach represents background conditions during base flow immediately upstream from the Lark and Henrietta mines (samples PG5 to PG45). Other samples were collected during storm runoff conditions (PG100 to PG291); during the first flush of metal runoff following the onset of rainfall (PG303 to PG504), and samples PG542 to PG700 were collected during low-flow conditions. During base-flow conditions, the percentage increase in loads for major constituents and trace metals was more than an order of magnitude greater than the corresponding 36 % increase in stream discharge. Within the study reach, the highest percentage increases for dissolved loads were 740 % for iron (Fe), 465 % for aluminum (Al), 500 % for lead (Pb), 380 % for copper (Cu), 100 % for sulfate (SO4), and 50 % for zinc (Zn). Downstream loads near the mouth of Prospect Gulch often greatly exceeded the loads generated within the study reach but varied by metal species. For example, the study reach accounts for about 6 % of the dissolved

  18. Development and Validation of a Statistical Shape Modeling-Based Finite Element Model of the Cervical Spine Under Low-Level Multiple Direction Loading Conditions

    PubMed Central

    Bredbenner, Todd L.; Eliason, Travis D.; Francis, W. Loren; McFarland, John M.; Merkle, Andrew C.; Nicolella, Daniel P.

    2014-01-01

    Cervical spinal injuries are a significant concern in all trauma injuries. Recent military conflicts have demonstrated the substantial risk of spinal injury for the modern warfighter. Finite element models used to investigate injury mechanisms often fail to examine the effects of variation in geometry or material properties on mechanical behavior. The goals of this study were to model geometric variation for a set of cervical spines, to extend this model to a parametric finite element model, and, as a first step, to validate the parametric model against experimental data for low-loading conditions. Individual finite element models were created using cervical spine (C3–T1) computed tomography data for five male cadavers. Statistical shape modeling (SSM) was used to generate a parametric finite element model incorporating variability of spine geometry, and soft-tissue material property variation was also included. The probabilistic loading response of the parametric model was determined under flexion-extension, axial rotation, and lateral bending and validated by comparison to experimental data. Based on qualitative and quantitative comparison of the experimental loading response and model simulations, we suggest that the model performs adequately under relatively low-level loading conditions in multiple loading directions. In conclusion, SSM methods coupled with finite element analyses within a probabilistic framework, along with the ability to statistically validate the overall model performance, provide innovative and important steps toward describing the differences in vertebral morphology, spinal curvature, and variation in material properties. We suggest that these methods, with additional investigation and validation under injurious loading conditions, will lead to understanding and mitigating the risks of injury in the spine and other musculoskeletal structures. PMID:25506051

  19. Truck accident and fatality rates calculated from California highway accident statistics for 1980 and 1981

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

    Smith, R.N.; Wilmot, E.L.

    California state highway accident rates for three types of truck vehicles (pickup, truck without trailer, and truck with trailer) were analyzed for 1980 and 1981 and for various road types in each of eleven state highway districts. Accident rates have not been available previously that are specific to truck vehicles, particularly truck with trailer. Reported data are presented that lead to several significant observations about truck accident rates: pickup truck accident rates are about twice the composite rates for all vehicle types; the fatality rates for trucks with trailer are nearly twice that for all vehicle types; fatality rates formore » trucks (without trailer) are comparable to the composite rates; and total accident and fatal-plus-injury rates for trucks with trailer are close to the composite rates in urban areas but higher in rural areas. The values for average total accident rates reported in 1981 are: 2.2 accidents per million vehicle miles (mvm) for pickups, 1.5 accidents per mvm for trucks, and 1.4 accidents per mvm for trucks with trailer. The values for average fatality rates reported in 1981 are: 3.8 fatalities per 100 mvm for pickups, 2.8 fatalities per 100 mvm for trucks, and 4.3 fatalities per 100 mvm for trucks with trailer. The reported rates for 1980 are approximately the same.« less

  20. 1995 Kentucky traffic accident facts

    DOT National Transportation Integrated Search

    1995-01-01

    KENTUCKYS TRAFFIC ACCIDENT FACTS report for 1995 is based on accident reports submitted to the Accident Unit housed : in the Kentucky State Police Information Services Branch, Records Section. As required by Kentucky Revised statutes 189.635, : ...

  1. 1996 Kentucky traffic accident facts

    DOT National Transportation Integrated Search

    1996-01-01

    KENTUCKYS TRAFFIC ACCIDENT FACTS report for 1996 is based on accident reports submitted to the Accident Unit housed : in the Kentucky State Police Information Services Branch, Records Section. As required by Kentucky Revised statutes 189.635, : ...

  2. 1998 Kentucky traffic accident facts

    DOT National Transportation Integrated Search

    1998-01-01

    KENTUCKYS TRAFFIC ACCIDENT FACTS report for 1998 is based on accident reports submitted to the Accident Unit housed : in the Kentucky State Police Information Services Branch, Records Section. As required by Kentucky Revised statutes 189.635, : ...

  3. 1997 Kentucky traffic accident facts

    DOT National Transportation Integrated Search

    1997-01-01

    KENTUCKYS TRAFFIC ACCIDENT FACTS report for 1997 is based on accident reports submitted to the Accident Unit housed : in the Kentucky State Police Information Services Branch, Records Section. As required by Kentucky Revised statutes 189.635, : ...

  4. Integrated modeling approach using SELECT and SWAT models to simulate source loading and in-stream conditions of fecal indicator bacteria.

    NASA Astrophysics Data System (ADS)

    Ranatunga, T.

    2016-12-01

    Modeling of fate and transport of fecal bacteria in a watershed is generally a processed based approach that considers releases from manure, point sources, and septic systems. Overland transport with water and sediments, infiltration into soils, transport in the vadose zone and groundwater, die-off and growth processes, and in-stream transport are considered as the other major processes in bacteria simulation. This presentation will discuss a simulation of fecal indicator bacteria (E.coli) source loading and in-stream conditions of a non-tidal watershed (Cedar Bayou Watershed) in South Central Texas using two models; Spatially Explicit Load Enrichment Calculation Tool (SELECT) and Soil and Water Assessment Tool (SWAT). Furthermore, it will discuss a probable approach of bacteria source load reduction in order to meet the water quality standards in the streams. The selected watershed is listed as having levels of fecal indicator bacteria that posed a risk for contact recreation and wading by the Texas Commission of Environmental Quality (TCEQ). The SELECT modeling approach was used in estimating the bacteria source loading from land categories. Major bacteria sources considered were, failing septic systems, discharges from wastewater treatment facilities, excreta from livestock (Cattle, Horses, Sheep and Goat), excreta from Wildlife (Feral Hogs, and Deer), Pet waste (mainly from Dogs), and runoff from urban surfaces. The estimated source loads were input to the SWAT model in order to simulate the transport through the land and in-stream conditions. The calibrated SWAT model was then used to estimate the indicator bacteria in-stream concentrations for future years based on H-GAC's regional land use, population and household projections (up to 2040). Based on the in-stream reductions required to meet the water quality standards, the corresponding required source load reductions were estimated.

  5. A comparison of the hazard perception ability of accident-involved and accident-free motorcycle riders.

    PubMed

    Cheng, Andy S K; Ng, Terry C K; Lee, Hoe C

    2011-07-01

    Hazard perception is the ability to read the road and is closely related to involvement in traffic accidents. It consists of both cognitive and behavioral components. Within the cognitive component, visual attention is an important function of driving whereas driving behavior, which represents the behavioral component, can affect the hazard perception of the driver. Motorcycle riders are the most vulnerable types of road user. The primary purpose of this study was to deepen our understanding of the correlation of different subtypes of visual attention and driving violation behaviors and their effect on hazard perception between accident-free and accident-involved motorcycle riders. Sixty-three accident-free and 46 accident-involved motorcycle riders undertook four neuropsychological tests of attention (Digit Vigilance Test, Color Trails Test-1, Color Trails Test-2, and Symbol Digit Modalities Test), filled out the Chinese Motorcycle Rider Driving Violation (CMRDV) Questionnaire, and viewed a road-user-based hazard situation with an eye-tracking system to record the response latencies to potentially dangerous traffic situations. The results showed that both the divided and selective attention of accident-involved motorcycle riders were significantly inferior to those of accident-free motorcycle riders, and that accident-involved riders exhibited significantly higher driving violation behaviors and took longer to identify hazardous situations compared to their accident-free counterparts. However, the results of the regression analysis showed that aggressive driving violation CMRDV score significantly predicted hazard perception and accident involvement of motorcycle riders. Given that all participants were mature and experienced motorcycle riders, the most plausible explanation for the differences between them is their driving style (influenced by an undesirable driving attitude), rather than skill deficits per se. The present study points to the importance of

  6. Accuracy of Virginia accident data.

    DOT National Transportation Integrated Search

    1981-09-01

    The sources, magnitude, and characteristics of the inaccuracies in Virginia's police-reported accident data were examined. Five techniques were used to (1) determine how accident data are documented, (2) examine the contents of the accident report us...

  7. Explaining the road accident risk: weather effects.

    PubMed

    Bergel-Hayat, Ruth; Debbarh, Mohammed; Antoniou, Constantinos; Yannis, George

    2013-11-01

    This research aims to highlight the link between weather conditions and road accident risk at an aggregate level and on a monthly basis, in order to improve road safety monitoring at a national level. It is based on some case studies carried out in Work Package 7 on "Data analysis and synthesis" of the EU-FP6 project "SafetyNet-Building the European Road Safety Observatory", which illustrate the use of weather variables for analysing changes in the number of road injury accidents. Time series analysis models with explanatory variables that measure the weather quantitatively were used and applied to aggregate datasets of injury accidents for France, the Netherlands and the Athens region, over periods of more than 20 years. The main results reveal significant correlations on a monthly basis between weather variables and the aggregate number of injury accidents, but the magnitude and even the sign of these correlations vary according to the type of road (motorways, rural roads or urban roads). Moreover, in the case of the interurban network in France, it appears that the rainfall effect is mainly direct on motorways--exposure being unchanged, and partly indirect on main roads--as a result of changes in exposure. Additional results obtained on a daily basis for the Athens region indicate that capturing the within-the-month variability of the weather variables and including it in a monthly model highlights the effects of extreme weather. Such findings are consistent with previous results obtained for France using a similar approach, with the exception of the negative correlation between precipitation and the number of injury accidents found for the Athens region, which is further investigated. The outlook for the approach and its added value are discussed in the conclusion. Copyright © 2013. Published by Elsevier Ltd.

  8. Exploring the relationship between alcohol and the driver characteristics in motor vehicle accidents.

    PubMed

    Abdel-Aty, M A; Abdelwahab, H T

    2000-07-01

    This study examines the differences in alcohol-related accident involvement among different driver groups in the state of Florida. The driver characteristics considered in this study are: age, gender, race, and residency of the driver of a motor vehicle involved in an accident while under the influence of alcohol, drugs, or alcohol and drugs. The main objective of this study is to test whether there are associations between the different driver characteristics and alcohol involvement in traffic accidents, and to identify the high-risk group within each driver factor. This would improve our understanding of the relationship between alcohol involvement, accidents, and the four aforementioned driver factors. It would also enable us to better design educational and awareness programs targeting specific groups in the population to reduce drinking and driving in the state. The relationship between alcohol-related accident involvement and the driver factors are investigated using general descriptive statistics, conditional probabilities and log-linear models. The results showed that the 25-34 age group experience the highest rate of alcohol/drug involvement in accidents. The rates decline with the increase in the age of the drivers. The results also indicated that there are significant relationships between the driver characteristics and alcohol/drug involvement in accidents. Male, white, and in-state drivers were also more involved in alcohol/drugs-related traffic accidents.

  9. [Hang-gliding accidents in high mountains. Apropos of 200 cases].

    PubMed

    Foray, J; Abrassart, S; Femmy, T; Aldilli, M

    1991-01-01

    A review of 200 cases of "paragliding" accidents in high mountain areas has been completed. The first flights have been murderous, a thesis written in 1987 in Grenoble showing seven dead out of 97 casualties. Since then the statistics seen to be improving as a consequence of the setting of regulations and the establishment of "paragliding" schools. The more frequent accidents happen on landing: in 70% of the cases fractures of the "tibiotarsienne", the wrist and the spinal column prevail. They happen to young adults between 20 and 40 years old, with a variable experience. Preventive measures consist in a greater prudence, a good physical condition and a precise aerological knowledge. The adepts of this sport have understood that wearing a helmet and appropriate shoes could reduce the gravity of the accidents. "Paragliding" if not a dangerous sport is certainly a risky one.

  10. [Psychological effects of road accidents: a challenge for public health].

    PubMed

    Waszkowska, Małgorzata; Merecz, Dorota

    2006-01-01

    The authors discuss psychological consequences of road accidents and the need for providing support for the victims and their families. The most common psychological effects include mental health problems, increased use of psychotropic drugs, and difficulty in performing occupational functions. Therefore, it is necessary to remodel the system of traffic safety and supplement it with a comprehensive system of support for both direct victims of accidents and their close relatives. To reach this goal, we need to develop optimal conditions for multidisciplinary research to investigate the effects of road accidents in Poland. This would make it possible to design effective psychological treatment and develop an institutional system for relevant support. However, some preventive measures can be taken right now, e.g., early intervention for severely injured victims during their hospital stay or providing support for non-injured victims and their families.

  11. Construction industry accidents in Spain.

    PubMed

    Camino López, Miguel A; Ritzel, Dale O; Fontaneda, Ignacio; González Alcantara, Oscar J

    2008-01-01

    This paper analyzed industrial accidents that take place on construction sites and their severity. Eighteen variables were studied. We analyzed the influence of each of these with respect to the severity and fatality of the accident. This descriptive analysis was grounded in 1,630,452 accidents, representing the total number of accidents suffered by workers in the construction sector in Spain over the period 1990-2000. It was shown that age, type of contract, time of accident, length of service in the company, company size, day of the week, and the remainder of the variables under analysis influenced the seriousness of the accident. IMPACT ON INJURY PREVENTION: The results obtained show that different training was needed, depending on the severity of accidents, for different age, length of service in the company, organization of work, and time when workers work. The research provides an insight to the likely causes of construction injuries in Spain. As a result of the analysis, industries and governmental agencies in Spain can start to provide appropriate strategies and training to the construction workers.

  12. 49 CFR 835.11 - Obtaining Board accident reports, factual accident reports, and supporting information.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Obtaining Board accident reports, factual accident reports, and supporting information. 835.11 Section 835.11 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL TRANSPORTATION SAFETY BOARD TESTIMONY OF BOARD EMPLOYEES § 835.11 Obtaining Board accident reports, factual...

  13. 49 CFR 835.11 - Obtaining Board accident reports, factual accident reports, and supporting information.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Obtaining Board accident reports, factual accident reports, and supporting information. 835.11 Section 835.11 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL TRANSPORTATION SAFETY BOARD TESTIMONY OF BOARD EMPLOYEES § 835.11 Obtaining Board accident reports, factual...

  14. 49 CFR 835.11 - Obtaining Board accident reports, factual accident reports, and supporting information.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Obtaining Board accident reports, factual accident reports, and supporting information. 835.11 Section 835.11 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL TRANSPORTATION SAFETY BOARD TESTIMONY OF BOARD EMPLOYEES § 835.11 Obtaining Board accident reports, factual...

  15. 49 CFR 835.11 - Obtaining Board accident reports, factual accident reports, and supporting information.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Obtaining Board accident reports, factual accident reports, and supporting information. 835.11 Section 835.11 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL TRANSPORTATION SAFETY BOARD TESTIMONY OF BOARD EMPLOYEES § 835.11 Obtaining Board accident reports, factual...

  16. Effects of tractor loads and tyre pressures on soil compaction in Tunisia under different moisture conditions

    NASA Astrophysics Data System (ADS)

    Khemis, Chiheb; Abrougui, Khaoula; Ren, Lidong; Mutuku, Eunice Ann; Chehaibi, Sayed; Cornelis, Wim

    2017-04-01

    Vegetables in Tunisia demand frequent tractor traffic for soil tillage, cultural operations and phytosanitary treatment, resulting in soil compaction. This study evaluates the effects of four levels of compaction by using different loads and tyre pressures of tractors, i.e., load 1 (C1) = 1460 kg, load 2 (C2) = 3100 kg, tyre pressure 1 (C3) = 800 kg cm-2, tyre pressure 2 (C4) = 1500 kg cm-2 on the hydraulic and physical properties of a sandy loam (10% clay, 20% silt, 68% sand) under three natural moisture conditions H0, H1 (15 days later), H2 (30 days later). At H0 average water content between 0 and 30 cm depth varied from 0.04 to 0.06 kg kg-1, at H1 between 0.13 and 0.07 kg kg-1, and at H2 between 0.10 and 0.09 kg kg-1. Each test run was limited to one pass. Undisturbed soil cores were collected in the topsoil (0-10 cm), at 10-20 cm and in the subsoil (20-30 cm) below the trace of the wheel at sites in the Higher Institute of Agronomy of Chott Mariam, Sousse, Tunisia. Soil compaction level was determined by penetration resistance using a penetrologger. Porosity, bulk density and permeability were then determined to evaluate the impact of the four load/tyre pressure combinations at the three moisture conditions on soil compaction. Prior to the experiment (C0), bulk density was 1.4 Mg m-3. After the tractor pass, the highest degree of compaction was observed with tractor load C2 and tyre pressure C4 which significantly changed soil bulk density resulting in values of up to 1.71 Mg m-3 in the topsoil and compacted subsoil under H2, which is significantly above the critical value of 1.6 Mg m-3 for soils with clay content below 17.5%. The high degree of compaction significantly affected penetration resistance and porosity of both topsoil and subsoil layers accordingly. Permeability was significantly reduced as a result of the induced compaction. The results demonstrate that different degrees of soil compaction under different moisture levels could greatly influence

  17. Multi-load Groups Coordinated Load Control Strategy Considering Power Network Constraints

    NASA Astrophysics Data System (ADS)

    Liu, Meng; Zhao, Binchao; Wang, Jun; Zhang, Guohui; Wang, Xin

    2017-05-01

    Loads with energy storage property can actively participate in power balance for power systems, this paper takes air conditioner as a controllable load example, proposing a multi-load groups coordinated load control strategy considering power network constraints. Firstly, two load control modes considering recovery of load diversity are designed, blocking power oscillation of aggregated air conditioners. As the same time, air conditioner temperature setpoint recovery control strategy is presented to avoid power recovery peak. Considering inherent characteristics of two load control modes, an coordinated load control mode is designed by combining the both. Basing on this, a multi-load groups coordinated load control strategy is proposed. During the implementing of load control, power network constraints should be satisfied. An indice which can reflect the security of power system operating is defined. By minimizing its value through optimization, the change of air conditioning loads’ aggregated power on each load bus can be calculated. Simulations are conducted on an air conditioners group and New England 10-generator 39-bus system, verifying the effectiveness of the proposed multi-load groups coordinated load control strategy considering power network constraints.

  18. Calculations of the skyshine gamma-ray dose rates from independent spent fuel storage installations (ISFSI) under worst case accident conditions

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

    Pace, J.V. III; Cramer, S.N.; Knight, J.R.

    1980-09-01

    Calculations of the skyshine gamma-ray dose rates from three spent fuel storage pools under worst case accident conditions have been made using the discrete ordinates code DOT-IV and the Monte Carlo code MORSE and have been compared to those of two previous methods. The DNA 37N-21G group cross-section library was utilized in the calculations, together with the Claiborne-Trubey gamma-ray dose factors taken from the same library. Plots of all results are presented. It was found that the dose was a strong function of the iron thickness over the fuel assemblies, the initial angular distribution of the emitted radiation, and themore » photon source near the top of the assemblies. 16 refs., 11 figs., 7 tabs.« less

  19. Report of the Presidential Commission on the Space Shuttle Challenger Accident, Volume 1

    NASA Technical Reports Server (NTRS)

    Rogers, W. P.; Armstrong, N. A.; Acheson, D. C.; Covert, E. E.; Feynman, R. P.; Hotz, R. B.; Kutyna, D. J.; Ride, S. K.; Rummel, R. W.; Sutter, J. F.

    1986-01-01

    The findings of the Commission regarding the circumstances surrounding the Challenger accident are reported and recommendations for corrective action are outlined. All available mission data, subsequent tests, and wreckage analyses were reviewed and specific failure scenarios were developed. The Commission concluded that the cause of the Mission 51-L accident was the failure of the pressure seal in the aft field joint of the right solid rocket motor. The failure was due to a faulty design unacceptably sensitive to a number of factors. These factors were the effects of temperature, physical dimensions, the character of materials, the effects of reuse, processing, and the reaction of the joint to dynamic loading. In addition to analyzing the material causes of the accident, the Commission examined the chain of decisions that culminated in approval of the launch. It concluded that the decision making process was flawed in several ways including (1) failure in communication resulting in a launch decision based on incomplete and misleading information, (2) a conflict between engineering data and management judgements, and (3) a NASA management structure that permitted flight safety problems to bypass key Shuttle managers.

  20. 28 CFR 301.106 - Repetitious accidents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Repetitious accidents. 301.106 Section 301.106 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE INMATE ACCIDENT COMPENSATION General § 301.106 Repetitious accidents. If an inmate worker is involved in successive accidents...

  1. 28 CFR 301.106 - Repetitious accidents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Repetitious accidents. 301.106 Section 301.106 Judicial Administration FEDERAL PRISON INDUSTRIES, INC., DEPARTMENT OF JUSTICE INMATE ACCIDENT COMPENSATION General § 301.106 Repetitious accidents. If an inmate worker is involved in successive accidents...

  2. Industrial accidents are related to relative body weight: the Israeli CORDIS study.

    PubMed Central

    Froom, P; Melamed, S; Kristal-Boneh, E; Gofer, D; Ribak, J

    1996-01-01

    OBJECTIVES: The accident rate might be influenced by intrinsic characteristics of the workers, by risks inherent in the work environment, or a combination of these factors. As increased weight may be associated with sleep disturbances and fatigue, a high body mass index (BMI) might be an independent risk factor for accidents in industrial workers. METHODS: 3801 men were examined and followed up for two years for the occurrence of accidents. The objective environmental conditions were recorded and translated into a single score of ergonomic stress levels. Height and weight were recorded, as were possible confounding factors including measures of fatigue, type A personality, total night time sleep, job satisfaction, somatic complaints, smoking, and education levels. RESULTS: Both BMI and ergonomic stress levels independently predicted involvement in accidents (two or more) with those in the highest BMI quartile who worked in an environment with high ergonomic stress levels having a 4-6 times increased risk of accidents compared with those in the lowest BMI quartile who worked in an environment with low ergonomic stress levels (95% confidence interval (95% CI) 2.4-9.0, P < 0.001). Although increasing somatic complaints and a low educational level also were predictors of accidents, they did not mediate the effect of the BMI on the accident rate. Increasing age, less smoking, and decreased sleep hours were significantly associated with an increased BMI, but the association of BMI and involvement in accidents also could not be explained by those factors or the other confounders. CONCLUSIONS: BMI independently influences the accident rate. Further studies warranted to confirm these findings and to explore mechanisms supporting biological plausibility. PMID:9004929

  3. Preoperative conditioning with oral carbohydrate loading and oral nutritional supplements can be combined with mechanical bowel preparation prior to elective colorectal resection.

    PubMed

    Hendry, P O; Balfour, A; Potter, M A; Mander, B J; Bartolo, D C C; Anderson, D N; Fearon, K C H

    2008-11-01

    Preoperative conditioning with oral fluid and carbohydrate (CHO) loading allows the patient to undergo surgery in the fed state and is associated with reduced postoperative insulin resistance. Further benefit may accrue from oral nutritional supplements (ONS) to counteract the fasting associated with mechanical bowel preparation (MBP). In this study we assess the ability to prescribe, dispense and have patients comply with a protocol combining preoperative ONS and CHO/fluid loading during MBP. One hundred and forty-seven patients undergoing elective left colonic or rectal resection were recruited to an Enhanced Recovery after Surgery (ERAS) programme. All patients were prescribed MBP (2 sachets Picolax). On the daytime prior to surgery, eligible patients were prescribed 2 x 200 ml of ONS (Fortijuice, Nutricia) and in the evening 800 ml oral CHO/fluid loading (Preop(R), Nutricia,). Patients were prescribed a further 400 ml of oral/CHO/fluid on the morning of surgery 2 h prior to induction of anaesthesia. Protocol compliance was audited prospectively. One hundred and forty-seven patients received MBP. Twenty-three patients were ineligible for oral CHO/fluid loading [diabetes (n = 22), allergy to lemon flavoured drinks (n = 1)]. Fourteen patients did not receive the preoperative CHO drinks due to failure to prescribe (n = 8) or dispense (n = 6). One hundred and ten patients were dispensed the combined ONS and CHO/fluid loading regimen, compliance rates were 83% with ONS, 80% with CHO/fluid loading and 74% with both. Approximately 74% of patients undergoing MBP can comply with preoperative conditioning with ONS and CHO/fluid loading. Prescription and dispensing requires close attention to detail.

  4. Comparison of Damage Models for Predicting the Non-Linear Response of Laminates Under Matrix Dominated Loading Conditions

    NASA Technical Reports Server (NTRS)

    Schuecker, Clara; Davila, Carlos G.; Rose, Cheryl A.

    2010-01-01

    Five models for matrix damage in fiber reinforced laminates are evaluated for matrix-dominated loading conditions under plane stress and are compared both qualitatively and quantitatively. The emphasis of this study is on a comparison of the response of embedded plies subjected to a homogeneous stress state. Three of the models are specifically designed for modeling the non-linear response due to distributed matrix cracking under homogeneous loading, and also account for non-linear (shear) behavior prior to the onset of cracking. The remaining two models are localized damage models intended for predicting local failure at stress concentrations. The modeling approaches of distributed vs. localized cracking as well as the different formulations of damage initiation and damage progression are compared and discussed.

  5. A dangerous seaplane landing condition

    NASA Technical Reports Server (NTRS)

    Carroll, Thomas

    1928-01-01

    A peculiar phenomena in seaplane landing is observed and reported. The seaplane having executed a normal fast landing at low incidence, a forward movement of the control stick effected an unusual condition in that the seaplane left the water suddenly in an abnormal attitude. The observations describing this phenomena are offered as a warning against possible accident and as a conjectural cause of seaplane landing accidents of a certain kind.

  6. Nonlinear dynamic analysis of a rotor-bearing-seal system under two loading conditions

    NASA Astrophysics Data System (ADS)

    Ma, Hui; Li, Hui; Niu, Heqiang; Song, Rongze; Wen, Bangchun

    2013-11-01

    The operating speed of the rotating machinery often exceeds the second or even higher order critical speeds to pursue higher efficiency. Thus, how to restrain the higher order mode instability caused by the nonlinear oil-film force and seal force at high speed as far as possible has become more and more important. In this study, a lumped mass model of a rotor-bearing-seal system considering the gyroscopic effect is established. The graphite self-lubricating bearing and the sliding bearing are simulated by a spring-damping model and a nonlinear oil-film force model based on the assumption of short bearings, respectively. The seal is simulated by Muszynska nonlinear seal force model. Effects of the seal force and oil-film force on the first and second mode instabilities are investigated under two loading conditions which are determined by API Standard 617 (Axial and Centrifugal Compressors and Expander-compressors for Petroleum, Chemical and Gas Industry Services, Seventh Edition). The research focuses on the effects of exciting force forms and their magnitudes on the first and second mode whips in a rotor-bearing-seal system by using the spectrum cascades, vibration waveforms, orbits and Poincaré maps. The first and second mode instability laws are compared by including and excluding the seal effect in a rotor system with single-diameter shaft and two same discs. Meanwhile, the instability laws are also verified in a rotor system with multi-diameter shaft and two different discs. The results show that the second loading condition (out-of-phase unbalances of two discs) and the nonlinear seal force can mainly restrain the first mode instability and have slight effects on the second mode instability. This study may contribute to a further understanding about the higher order mode instability of such a rotor system with fluid-induced forces from the oil-film bearings and seals.

  7. Workplace accidents in materials transfer in Finland.

    PubMed

    Perttula, Pia; Salminen, Simo

    2012-01-01

    The aim of this study was to show the proportion of workplace accidents related to materials transfer and to decide whether they were more serious than other kinds of workplace accidents. The research material for this study were statistics and data, available in Finland, regarding workplace accidents and fatal accidents. Twenty-five percent of studied fatal accidents were related to materials transfer; 26.9-27.7% of all workplace accidents in Finland in 2003-2007 were workplace accidents related to materials transfer. Over half (54.7%) of workplace accidents related to materials transfer caused disabilities lasting over 3 days. Most accidents related to materials transfer occurred to men aged 20-49 years. The most common types of injuries were dislocations, sprains and strains.

  8. 32 CFR 644.532 - Reporting accidents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Reporting accidents. 644.532 Section 644.532... and Improvements § 644.532 Reporting accidents. Immediately upon receipt of information of an accident... that an accident has occurred, the former using command should be requested to send qualified explosive...

  9. 49 CFR 845.40 - Accident report.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Accident report. 845.40 Section 845.40... RULES OF PRACTICE IN TRANSPORTATION; ACCIDENT/INCIDENT HEARINGS AND REPORTS Board Reports § 845.40 Accident report. (a) The Board will issue a detailed narrative accident report in connection with the...

  10. Offsite radiological consequence analysis for the bounding flammable gas accident

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

    CARRO, C.A.

    2003-03-19

    The purpose of this analysis is to calculate the offsite radiological consequence of the bounding flammable gas accident. DOE-STD-3009-94, ''Preparation Guide for U.S. Department of Energy Nonreactor Nuclear Facility Documented Safety Analyses'', requires the formal quantification of a limited subset of accidents representing a complete set of bounding conditions. The results of these analyses are then evaluated to determine if they challenge the DOE-STD-3009-94, Appendix A, ''Evaluation Guideline,'' of 25 rem total effective dose equivalent in order to identify and evaluate safety class structures, systems, and components. The bounding flammable gas accident is a detonation in a single-shell tank (SST).more » A detonation versus a deflagration was selected for analysis because the faster flame speed of a detonation can potentially result in a larger release of respirable material. As will be shown, the consequences of a detonation in either an SST or a double-shell tank (DST) are approximately equal. A detonation in an SST was selected as the bounding condition because the estimated respirable release masses are the same and because the doses per unit quantity of waste inhaled are generally greater for SSTs than for DSTs. Appendix A contains a DST analysis for comparison purposes.« less

  11. Health condition identification of multi-stage planetary gearboxes using a mRVM-based method

    NASA Astrophysics Data System (ADS)

    Lei, Yaguo; Liu, Zongyao; Wu, Xionghui; Li, Naipeng; Chen, Wu; Lin, Jing

    2015-08-01

    Multi-stage planetary gearboxes are widely applied in aerospace, automotive and heavy industries. Their key components, such as gears and bearings, can easily suffer from damage due to tough working environment. Health condition identification of planetary gearboxes aims to prevent accidents and save costs. This paper proposes a method based on multiclass relevance vector machine (mRVM) to identify health condition of multi-stage planetary gearboxes. In this method, a mRVM algorithm is adopted as a classifier, and two features, i.e. accumulative amplitudes of carrier orders (AACO) and energy ratio based on difference spectra (ERDS), are used as the input of the classifier to classify different health conditions of multi-stage planetary gearboxes. To test the proposed method, seven health conditions of a two-stage planetary gearbox are considered and vibration data is acquired from the planetary gearbox under different motor speeds and loading conditions. The results of three tests based on different data show that the proposed method obtains an improved identification performance and robustness compared with the existing method.

  12. Half-century research developments in maritime accidents: Future directions.

    PubMed

    Luo, Meifeng; Shin, Sung-Ho

    2016-04-19

    Over the past 50 years, research in maritime accidents has undergone a series of fundamental changes. Understanding the evolution of these changes can help maritime communities to know what has been done in the past, how maritime safety can be improved in the future, and how to reduce or eliminate the risks to ships, the lives aboard them, the cargo they carry, and the marine environment. This study conducts a comprehensive literature review on research in maritime accidents, comprising 572 papers published in 125 journals over the 50 years from 1965 to 2014. The patterns of evolution of the researchers, the journals, the disciplines involved, the research methods, the major issues and causes, and the data sources are identified, and the changes explained. We find that the main focus of research in maritime accidents has shifted over the past 50 years from naval architecture to human error, and may continue to expand into socio-economic factors. In addition, future research in maritime accidents will be multi-disciplinary, use multiple data sources, and adopt advanced research methods, to account for complex interactions between the natural environment, the development of naval technology, human behavior, and shipping market conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. 49 CFR 801.32 - Accident reports.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Accident reports. 801.32 Section 801.32... PUBLIC AVAILABILITY OF INFORMATION Accident Investigation Records § 801.32 Accident reports. (a) The NTSB....S. civil transportation accidents, in accordance with 49 U.S.C. 1131(e). (b) These reports may be...

  14. 41 CFR 102-74.360 - What are the specific accident and fire prevention responsibilities of occupant agencies?

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... appropriate fire safety precautions in their work; (i) Keep facilities in the safest condition practicable... accident and fire prevention responsibilities of occupant agencies? 102-74.360 Section 102-74.360 Public... MANAGEMENT REGULATION REAL PROPERTY 74-FACILITY MANAGEMENT Facility Management Accident and Fire Prevention...

  15. 41 CFR 102-74.360 - What are the specific accident and fire prevention responsibilities of occupant agencies?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... appropriate fire safety precautions in their work; (i) Keep facilities in the safest condition practicable... accident and fire prevention responsibilities of occupant agencies? 102-74.360 Section 102-74.360 Public... MANAGEMENT REGULATION REAL PROPERTY 74-FACILITY MANAGEMENT Facility Management Accident and Fire Prevention...

  16. 41 CFR 102-74.360 - What are the specific accident and fire prevention responsibilities of occupant agencies?

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... appropriate fire safety precautions in their work; (i) Keep facilities in the safest condition practicable... accident and fire prevention responsibilities of occupant agencies? 102-74.360 Section 102-74.360 Public... MANAGEMENT REGULATION REAL PROPERTY 74-FACILITY MANAGEMENT Facility Management Accident and Fire Prevention...

  17. Evaluation of the operating resource of the most loaded rotor element of the additional steam turbine with steam-hydrogen overheat of the working fluid at a nuclear power station

    NASA Astrophysics Data System (ADS)

    Bairamov, A. N.

    2017-11-01

    The operation of a nuclear power plant with a hydrogen energy complex and a constantly operating low capacity additional steam turbine makes it possible to improve the reliability of the power supply to the needs of a nuclear power plant in the face of major systemic accidents. In this case, the additional steam turbine is always in operation. This determines the alternation of the operating conditions of the additional steam turbine, and, at the same time, the alternation of the loads attributable to the rotor, which affects its working life. The aim of the article is to investigate the effect of cyclic loads on the number of cycles before the destruction of the most important elements of the rotor of an additional steam turbine due to the alternation of operating conditions when entering the peak load and during unloading at night. The article demonstrates that the values of the stress range intensity index for the most important elements of the rotor of an additional steam turbine lie in the area of the threshold values of the fatigue failure diagram. For this region, an increase in the frequency of loading is associated with the phenomenon of closure of the fatigue crack and, as a consequence, a possible slowing of its growth. An approximate number of cycles before failure for the most loaded element of the rotor is obtained.

  18. The determination of equivalent bearing loading for the BSMT that simulate SSME high pressure oxidizer turbopump conditions using the SHABERTH/SINDA computer programs

    NASA Technical Reports Server (NTRS)

    Mcdonald, Gary H.

    1987-01-01

    The MSFC bearing seal material tester (BSMT) can be used to evaluate the SSME high pressure oxygen turbopump (HPOTP) bearing performance. The four HPOTP bearings have both an imposed radial and axial load. These radial and axial loads are caused by the HPOTP's shaft, main impeller, preburner impeller, turbine and by the LOX coolant flow through the bearings, respectively. These loads coupled with bearing geometry and operating speed can define bearing contact angle, contact Hertz stress, and heat generation rates. The BSMT has the capability of operating at HPOTP shaft speeds, provide proper coolant flowrates but can only apply an axial load. Due to the inability to operate the bearings in the BSMT with an applied radial load, it is important to develop an equivalency between the applied axial loads and the actual HPOTP loadings. A shaft-bearing-thermal computer code (SHABERTH/SINDA) is used to simulate the BSMT bearing-shaft geometry and thermal-fluid operating conditions.

  19. [Occupational physician's role in the prevention of the accidents in construction industry].

    PubMed

    Mosconi, G; Riva, M M; Apostoli, P

    2008-01-01

    The aim of this work is to discuss about the role of the occupational physician in the prevention of the accidents in construction industry. Using the experience of 12 years of surveillance of workers in Bergamo province, the authors analyse the "human factors" which may influence the risk to have an accident, and the role of the physicians not only for the early diagnosis of work-related diseases, but also for the formulation of correct fitness to work, which consider accidents' prevention. Health conditions, psychological elements, fatigue and life style are some of the most important "human factors" which can amplify the accident phenomenon in construction industry. Our experience demonstrates that the occupational physicians can operate in preventive way on these factors, formulating correct fitness to work, giving their collaboration in the risk evaluation and management, suggesting runs of rehabilitation and recovery for the workers who need it, promoting information meetings related to the correct life habits.

  20. A comparative study of road traffic accidents in West Malaysia.

    PubMed

    Silva, J F

    1978-11-01

    The problem of road traffic accidents in developing countries is now becoming a cause for concern. This is more so as preventive measures have not kept pace with economic progress and development. This paper reviews the present situation in West Malaysia, one of the better developed countries of the East, during the period 1970 to 1975. A comparative study has been made between the United States and Malaysia. To enable the urgency of the problem in developing countries to be appreciated the increases in the country's population and in the number of vehicles in use and their relation to the lesser increase in road mileage over the period of study have been discussed. The study has considered every aspect of the causative factors leading to traffic accidents, such as the effects of weather, seasonal variation, and road and lighting conditions. The common human errors leading to accidents have been discussed. Other factors, such as the ethnic distribution in Malaysia, and their relation to road accidents have shown the effect of the social structure on the problems. The data evaluated in this study make it clear that preventive measures are very necessary in underdeveloped as well as in developed countries.

  1. Cognitive load, stress, and disinhibited eating.

    PubMed

    Lattimore, Paul; Maxwell, Linda

    2004-11-01

    The impact of cognitive distraction on eating behaviour was examined in restrained and unrestrained eaters. It was predicted that restrained eaters would eat more than unrestrained eaters following high cognitive load when it involves processing of ego-threat information independent of self-reported anxiety. There were 119 female participants randomly allocated to one of four experimental conditions whereby cognitive load and ego threat were manipulated using modified colour-naming Stroop (CNS) tasks. Anxiety ratings were made prior to and following experimental tasks. After performing Stroop tasks, participants consumed snack foods ad libitum. Restrained eaters consumed significantly more food when high cognitive load was ego threatening than when it involved processing and memorisation of colour nouns and consumed significantly more than unrestrained eaters in a high cognitive load ego-threat condition. Posttask anxiety was greater than baseline across all conditions. Task difficulty was greater under high cognitive load than low cognitive load as indicated by Stroop response times. These results indicated that the escape theory of disinhibited eating is conceptually subsumed by a more generalisable limited cognitive capacity model.

  2. 49 CFR 230.22 - Accident reports.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 4 2011-10-01 2011-10-01 false Accident reports. 230.22 Section 230.22... Requirements § 230.22 Accident reports. In the case of an accident due to failure, from any cause, of a steam... persons, the railroad on whose line the accident occurred shall immediately make a telephone report of the...

  3. 49 CFR 230.22 - Accident reports.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Accident reports. 230.22 Section 230.22... Requirements § 230.22 Accident reports. In the case of an accident due to failure, from any cause, of a steam... persons, the railroad on whose line the accident occurred shall immediately make a telephone report of the...

  4. An Evaluation of the HVAC Load Potential for Providing Load Balancing Service

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

    Lu, Ning

    This paper investigates the potential of providing aggregated intra-hour load balancing services using heating, ventilating, and air-conditioning (HVAC) systems. A direct-load control algorithm is presented. A temperature-priority-list method is used to dispatch the HVAC loads optimally to maintain consumer-desired indoor temperatures and load diversity. Realistic intra-hour load balancing signals were used to evaluate the operational characteristics of the HVAC load under different outdoor temperature profiles and different indoor temperature settings. The number of HVAC units needed is also investigated. Modeling results suggest that the number of HVACs needed to provide a {+-}1-MW load balancing service 24 hours a day variesmore » significantly with baseline settings, high and low temperature settings, and the outdoor temperatures. The results demonstrate that the intra-hour load balancing service provided by HVAC loads meet the performance requirements and can become a major source of revenue for load-serving entities where the smart grid infrastructure enables direct load control over the HAVC loads.« less

  5. Public Health Profile of Road Traffic Accidents in Kosovo 2010-2015.

    PubMed

    Ramadani, Naser; Zhjeqi, Valbona; Berisha, Merita; Hoxha, Rina; Begolli, Ilir; Salihu, Drita; Krasniqi, Pranvera

    2017-12-15

    To determine the characteristics of the Socio-medical profile of road traffic accidents in Kosovo, between 2010 and 2015 year. Retrospective study. A descriptive method based on the database of road traffic accidents from the National Police of Kosovo. In Kosovo for the period 2010-2015, on average, the yearly number of road traffic accidents is 18437 with mortality rate 7.4 per 100000 and lethality of 1.5%. The highest number of fatal cases are drivers and above 19 years old with more than 80%. Among injured significantly highest percentage is among passengers for all years and above 19 years old. Road traffic accident with a vehicle occurs most frequently, with approximately over 70%, mostly on dry road 72.9% and clear weather 71.1%. The driver is the contributing factors of road traffic accidents on average 99.3% whereas climatic conditions only 0.5%, with over 50% of crashes occurring in urban road 56.2%, mostly during Monday 16.0% and in the afternoon rush hours between 14.00-18.00 with 31.0%. There is a slight decrease in the mortality rate of 0.1‰ and lethality rate of 0.1% each year, whereas there is an increase of 21.5‰ for traumatism rate for each year.

  6. Designing an Experimental "Accident"

    ERIC Educational Resources Information Center

    Picker, Lester

    1974-01-01

    Describes an experimental "accident" that resulted in much student learning, seeks help in the identification of nematodes, and suggests biology teachers introduce similar accidents into their teaching to stimulate student interest. (PEB)

  7. Effect of load transients on SOFC operation—current reversal on loss of load

    NASA Astrophysics Data System (ADS)

    Gemmen, Randall S.; Johnson, Christopher D.

    The dynamics of solid oxide fuel cell (SOFC) operation have been considered previously, but mainly through the use of one-dimensional codes applied to co-flow fuel cell systems. In this paper several geometries are considered, including cross-flow, co-flow, and counter-flow. The details of the model are provided, and the model is compared with some initial experimental data. For parameters typical of SOFC operation, a variety of transient cases are investigated, including representative load increase and decrease and system shutdown. Of particular note for large load decrease conditions (e.g., shutdown) is the occurrence of reverse current over significant portions of the cell, starting from the moment of load loss up to the point where equilibrated conditions again provide positive current. Consideration is given as to when such reverse current conditions might most significantly impact the reliability of the cell.

  8. Workplace accidents and self-organized criticality

    NASA Astrophysics Data System (ADS)

    Mauro, John C.; Diehl, Brett; Marcellin, Richard F.; Vaughn, Daniel J.

    2018-09-01

    The occurrence of workplace accidents is described within the context of self-organized criticality, a theory from statistical physics that governs a wide range of phenomena across physics, biology, geosciences, economics, and the social sciences. Workplace accident data from the U.S. Bureau of Labor Statistics reveal a power-law relationship between the number of accidents and their severity as measured by the number of days lost from work. This power-law scaling is indicative of workplace accidents being governed by self-organized criticality, suggesting that nearly all workplace accidents have a common underlying cause, independent of their severity. Such power-law scaling is found for all labor categories documented by the U.S. Bureau of Labor Statistics. Our results provide scientific support for the Heinrich accident triangle, with the practical implication that suppressing the rate of severe accidents requires changing the attitude toward workplace safety in general. By creating a culture that values safety, empowers individuals, and strives to continuously improve, accident rates can be suppressed across the full range of severities.

  9. Strain field reconstruction on composite spars based on the identification of equivalent load conditions

    NASA Astrophysics Data System (ADS)

    Airoldi, A.; Marelli, L.; Bettini, P.; Sala, G.; Apicella, A.

    2017-04-01

    Technologies based on optical fibers provide the possibility of installing relatively dense networks of sensors that can perform effective strain sensing functions during the operational life of structures. A contemporary trend is the increasing adoption of composite materials in aerospace constructions, which leads to structural architectures made of large monolithic elements. The paper is aimed at showing the feasibility of a detailed reconstruction of the strain field in a composite spar, which is based on the development of reference finite element models and the identification of load modes, consisting of a parameterized set of forces. The procedure is described and assessed in ideal conditions. Thereafter, a surrogate model is used to obtain realistic representation of the data acquired by the strain sensing system, so that the developed procedure is evaluated considering local effects due to the introduction of loads, significant modelling discrepancy in the development of the reference model and the presence of measurement noise. Results show that the method can obtain a robust and quite detailed reconstruction of strain fields, even at the level of local distributions, of the internal forces in the spars and of the displacements, by identifying an equivalent set of load parameters. Finally, the trade-off between the number of sensor and the accuracy, and the optimal position of the sensors for a given maximum number of sensors is evaluated by performing a multi-objective optimization, thus showing that even a relative dense network of externally applied sensors can be used to achieve good quality results.

  10. Rough set approach for accident chains exploration.

    PubMed

    Wong, Jinn-Tsai; Chung, Yi-Shih

    2007-05-01

    This paper presents a novel non-parametric methodology--rough set theory--for accident occurrence exploration. The rough set theory allows researchers to analyze accidents in multiple dimensions and to model accident occurrence as factor chains. Factor chains are composed of driver characteristics, trip characteristics, driver behavior and environment factors that imply typical accident occurrence. A real-world database (2003 Taiwan single auto-vehicle accidents) is used as an example to demonstrate the proposed approach. The results show that although most accident patterns are unique, some accident patterns are significant and worth noting. Student drivers who are young and less experienced exhibit a relatively high possibility of being involved in off-road accidents on roads with a speed limit between 51 and 79 km/h under normal driving circumstances. Notably, for bump-into-facility accidents, wet surface is a distinctive environmental factor.

  11. Road traffic accident related morbidity as seen in an accident and emergency department.

    PubMed

    Galloway, D J; Patel, A R

    1981-04-01

    This paper describes some of the findings of a prospective study of victims of road traffic accidents arriving at the Western Infirmary's Accident and Emergency Department over a period of 12 months. More than half the accidents occurred during leisure hours thus likely to stretch the resource of the hospital services. More than a third of the total number of patients were young male drivers. Serious injuries were significantly more often sustained among pedestrians who were often older. Victims of motor-cycle accidents less often escaped serious injuries. Blood ethanol studies on a small sample suggested that male pedestrians were often highly intoxicated. A public health education programme is regarded as a primary measure in preventing a large proportion of serious morbidity and mortality especially amongst pedestrians.

  12. 41 CFR 101-39.407 - Accident records.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 41 Public Contracts and Property Management 2 2011-07-01 2007-07-01 true Accident records. 101-39...-INTERAGENCY FLEET MANAGEMENT SYSTEMS 39.4-Accidents and Claims § 101-39.407 Accident records. If GSA's records of vehicle accidents indicate that a particular activity has had an unusually high accident frequency...

  13. [Accidents on Iceland's most dangerous roads].

    PubMed

    Bjarnason, Thóroddur; Arnarsson, Sveinn

    2012-02-01

    The objective of this paper was to identify the most dangerous segments of the Icelandic road system in terms of the number of accidents pr km and the rate of accidents pr million km travelled. First to identify the segments where the number of accidents is highest and where the risk of the individual traveller is the greatest. Second to evaluate if the association between the number and the rate of accidents is positive or negative. Third to identify the road segments that are the most dangerous in the sense of many accidents and great risk to individual travellers. Main roads outside urban centers were divided into 45 segments that were on average 78 km in length. Infrequently travelled roads and roads within urban centers were omitted. Information on the length of roads, traffic density and number of accidents was used to calculate the number of accidents per km and the rate of accidents per million km travelled. The correlation between the number and rate of accidents was calculated and the most dangerous road segments were identified by the average rank order on both dimensions. Most accidents pr km occurred on the main roads to and from the capital region, but also east towards Hvolsvöllur, north towards Akureyri and in the Mideast region of the country. The rate of accidents pr million km travelled was highest in the northeast region, in northern Snæfellsnes and in the Westfjords. The most dangerous roads on both dimensions were in Mideast, northern Westfjords, in the north between Blönduós and Akureyri and in northern Snæfellsnes. Most accidents pr km occurred on roads with a low accident rate pr million km travelled. It is therefore possible to reduce accidents the most by increasing road safety where it is already the greatest but that would however increase inequalities in road safety. Policy development in transportation is therefore in part a question of priorities in healthcare. Individual equality in safety and health are not always fully

  14. Epstein-Barr virus viral load and serology in childhood non-Hodgkin's lymphoma and chronic inflammatory conditions in Uganda: implications for disease risk and characteristics.

    PubMed

    Orem, Jackson; Sandin, Sven; Mbidde, Edward; Mangen, Fred Wabwire; Middeldorp, Jaap; Weiderpass, Elisabete

    2014-10-01

    Epstein-Barr virus (EBV) has been linked to malignancies and chronic inflammatory conditions. In this study, EBV detection was compared in children with non-Hodgkin's lymphoma and children with chronic inflammatory conditions, using samples and data from a case-control study carried out at the Mulago National Referral Hospital between 2004 and 2008. EBV viral load was measured in saliva, whole blood and white blood cells by real-time PCR. Serological values for IgG-VCA, EBNA1, and EAd-IgG were compared in non-Hodgkin's lymphoma and chronic inflammatory conditions; and in Burkitt's lymphoma and other subtypes of non-Hodgkin's lymphoma. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated. Of the 127 children included (87 males and 40 females; median age 7 years, range 2-17), 96 had non-Hodgkin's lymphoma (46 Burkitt's lymphoma and 50 other non-Hodgkin's lymphoma), 31 had chronic inflammatory conditions, and only 10% were HIV-positive. The most common clinical presentations for all disease categories considered were fever, night sweats, and weight loss. EBV viral load in whole blood was elevated in Burkitt's lymphoma compared to other non-Hodgkin's lymphoma (OR 6.67, 95% CI 1.32, 33.69; P-value = 0.04), but EBV viral loads in saliva and white blood cells were not different in any of the disease categories considered. A significant difference in EAd-IgG was observed when non-Hodgkin's lymphoma was compared with chronic inflammatory conditions (OR 0.19, 95% CI 0.07, 0.51; P-value = 0.001). When compared to chronic inflammatory conditions, EBV viral load was elevated in Burkitt's lymphoma, and EA IgG was higher in non-Hodgkin's lymphoma. This study supports an association between virological and serological markers of EBV and childhood non-Hodgkin's lymphoma, irrespective of subtype, in Uganda. © 2014 Wiley Periodicals, Inc.

  15. Study concerning the loads over driver's chests in car crashes with cars of the same or different generation

    NASA Astrophysics Data System (ADS)

    Ispas, N.; Năstăsoiu, M.

    2016-08-01

    Reducing occupant injuries for cars involves in traffic accidents is a main target of today cars designers. Known as active or passive safety, many technological solutions were developing over the time for an actual better car's occupant safety. In the real world, in traffic accidents are often involved cars from different generations with various safety historical solutions. The main aim of these papers are to quantify the influences over the car driver chest loads in cases of same or different generation of cars involved in side car crashes. Both same and different cars generations were used for the study. Other goal of the paper was the study of in time loads conformity for diver's chests from both cars involved in crash. The paper's experimental results were obtained by support of DSD, Dr. Steffan Datentechnik GmbH - Linz, Austria. The described tests were performed in full test facility of DSD Linz, in “Easter 2015 PC-Crash Seminar”. In all crashes we obtaining results from both dummy placed in impacted and hits car. The novelty of the paper are the comparisons of data set from each of driver (dummy) of two cars involved in each of six experimental crashes. Another novelty of this paper consists in possibilities to analyse the influences of structural historical cars solutions over deformation and loads in cases of traffic accidents involved. Paper's conclusions can be future used for car passive safety improvement.

  16. 49 CFR 655.44 - Post-accident testing.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... the employer is unable to perform a post-accident test within the required period noted in paragraphs... 49 Transportation 7 2011-10-01 2011-10-01 false Post-accident testing. 655.44 Section 655.44... of Testing § 655.44 Post-accident testing. (a) Accidents. (1) Fatal accidents. (i) As soon as...

  17. 22 CFR 102.17 - Reports on accident.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Reports on accident. 102.17 Section 102.17... Accidents Abroad Foreign Aircraft Accidents Involving United States Persons Or Property § 102.17 Reports on accident. When an accident occurs to a foreign aircraft in the district of a Foreign Service post and...

  18. 22 CFR 102.17 - Reports on accident.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Reports on accident. 102.17 Section 102.17... Accidents Abroad Foreign Aircraft Accidents Involving United States Persons Or Property § 102.17 Reports on accident. When an accident occurs to a foreign aircraft in the district of a Foreign Service post and...

  19. Investigation of Zircaloy-2 oxidation model for SFP accident analysis

    NASA Astrophysics Data System (ADS)

    Nemoto, Yoshiyuki; Kaji, Yoshiyuki; Ogawa, Chihiro; Kondo, Keietsu; Nakashima, Kazuo; Kanazawa, Toru; Tojo, Masayuki

    2017-05-01

    The authors previously conducted thermogravimetric analyses on Zircaloy-2 in air. By using the thermogravimetric data, an oxidation model was constructed in this study so that it can be applied for the modeling of cladding degradation in spent fuel pool (SFP) severe accident condition. For its validation, oxidation tests of long cladding tube were conducted, and computational fluid dynamics analyses using the constructed oxidation model were proceeded to simulate the experiments. In the oxidation tests, high temperature thermal gradient along the cladding axis was applied and air flow rates in testing chamber were controlled to simulate hypothetical SFP accidents. The analytical outputs successfully reproduced the growth of oxide film and porous oxide layer on the claddings in oxidation tests, and validity of the oxidation model was proved. Influence of air flow rate for the oxidation behavior was thought negligible in the conditions investigated in this study.

  20. Fatal accident distribution by age, gender and head injury, and death probability at accident scene in Mashhad, Iran, 2006-2009.

    PubMed

    Zangooei Dovom, Hossein; Shafahi, Yousef; Zangooei Dovom, Mehdi

    2013-01-01

    endangered groups of road accident fatalities, which was conducted in this study, is invaluable for the appropriate design of prevention strategies and allocation of financial resources for each group of road user fatalities - since in developing nations, there are insufficient financial resources to traffic safety and we should consider superiorities, i.e. the most risky groups. Steps which may contribute to safety promotion for local conditions include suitable facilities for old pedestrians, a training course before obtaining motorcycle license for motorcyclists, informing young road users by provincial media about death risk of road users and improving management of the head-injured patients. Finally, suggestions for future researches were made.