WorldWideScience

Sample records for stress tests conducted

  1. Nuclear stress test

    Science.gov (United States)

    ... Persantine stress test; Thallium stress test; Stress test - nuclear; Adenosine stress test; Regadenoson stress test; CAD - nuclear stress; Coronary artery disease - nuclear stress; Angina - nuclear ...

  2. (stress) testing

    African Journals Online (AJOL)

    However, maximal HR was significantly higher in all groups during their sporting activities than during stress testing in the laboratory (P < 0.01). Conclusions. Maximal HR in veteran athletes during specific sporting activities was significantly higher than that attained during a routine sECG. This finding was not sport-specific, ...

  3. Test design requirements: Thermal conductivity probe testing

    International Nuclear Information System (INIS)

    Heath, R.E.

    1985-01-01

    This document establishes the test design requirements for development of a thermal conductivity probe test. The thermal conductivity probe determines in situ thermal conductivity using a line source transient heat conduction analysis. This document presents the rationale for thermal conductivity measurement using a thermal conductivity probe. A general test description is included. Support requirements along with design constraints are detailed to allow simple design of the thermal conductivity probe and test. The schedule and delivery requirements of the responsible test designer are also included. 7 refs., 1 fig

  4. 77 FR 3408 - Annual Stress Test

    Science.gov (United States)

    2012-01-24

    ...-2011-0029] RIN 1557-AD58 Annual Stress Test AGENCY: Office of the Comptroller of the Currency (``OCC... certain companies to conduct annual stress tests pursuant to regulations prescribed by their respective... stress test as prescribed by this proposed rule. In addition to the annual stress test requirement, such...

  5. Bone-Conduction ABR Tests.

    Science.gov (United States)

    Cone-Wesson, Barbara

    1995-01-01

    This article discusses the accuracy of bone-conduction auditory brainstem response (BC-ABR) tests to determine the presence and severity of conductive hearing impairment. It provides warnings about technical pitfalls and recommends incorporating BC-ABR protocols for routine clinical use. It concludes that the method allows estimating cochlear…

  6. Credibility and Crisis Stress Testing

    Directory of Open Access Journals (Sweden)

    Li Lian Ong

    2014-02-01

    Full Text Available Credibility is the bedrock of any crisis stress test. The use of stress tests to manage systemic risk was introduced by the U.S. authorities in 2009 in the form of the Supervisory Capital Assessment Program. Since then, supervisory authorities in other jurisdictions have also conducted similar exercises. In some of those cases, the design and implementation of certain elements of the framework have been criticized for their lack of credibility. This paper proposes a set of guidelines for constructing an effective crisis stress test. It combines financial markets impact studies of previous exercises with relevant case study information gleaned from those experiences to identify the key elements and to formulate their appropriate design. Pertinent concepts, issues and nuances particular to crisis stress testing are also discussed. The findings may be useful for country authorities seeking to include stress tests in their crisis management arsenal, as well as for the design of crisis programs.

  7. 77 FR 16484 - Annual Stress Test

    Science.gov (United States)

    2012-03-21

    ...-2011-0029] RIN 1557-AD58 Annual Stress Test AGENCY: Office of the Comptroller of the Currency, Treasury... billion to conduct an annual stress test and comply with certain reporting and disclosure requirements. To... conduct annual stress tests pursuant to regulations prescribed by their respective Federal primary...

  8. 77 FR 3166 - Annual Stress Test

    Science.gov (United States)

    2012-01-23

    ... FEDERAL DEPOSIT INSURANCE CORPORATION 12 CFR Part 325, Subpart C RIN 3064-AD91 Annual Stress Test... Reform and Consumer Protection Act (the ``Dodd-Frank Act'') regarding stress tests (``proposed rule... to conduct annual stress tests in accordance with the proposed rule, report the results of such...

  9. 77 FR 61238 - Annual Stress Test

    Science.gov (United States)

    2012-10-09

    ...-2011-0029] RIN 1557-AD58 Annual Stress Test AGENCY: Office of the Comptroller of the Currency (``OCC... conduct annual stress tests pursuant to regulations prescribed by their respective primary financial... annual stress test as prescribed by this rule. Under the final rule covered institutions are divided into...

  10. What Is Stress Testing?

    Science.gov (United States)

    ... would during exercise. You can then have the stress test. The medicine may make you flushed and anxious, but the effects go away as soon as the test is over. The medicine also may give you a headache. While you're exercising or getting medicine to ...

  11. Nonexercise cardiac stress testing

    International Nuclear Information System (INIS)

    Vacek, J.L.; Baldwin, T.

    1989-01-01

    Many patients who require evaluation for coronary artery disease are unable to undergo exercise stress testing because of physiologic or psychological limitations. Drs Vacek and Baldwin describe three alternative methods for assessment of cardiac function in these patients, all of which have high levels of diagnostic sensitivity and specificity. 23 references

  12. Stress testing in financial institutions

    Directory of Open Access Journals (Sweden)

    Mirković Vladimir

    2014-01-01

    Full Text Available In 2000 the Basle Committee on the Global Financial System defined stress testing as 'a generic term describing various techniques used by financial firms to gauge their potential vulnerability to exceptional but plausible events'. Exceptional events refer to one-off or recurring events with far-reaching consequences for the concerned financial institution and the financial sector s stability overall. Such unexpected (exceptional events include, for instance: bankruptcy in Argentina in 2001, stock markets collapse ('Black Monday' on 19 October 1987, or the fall of the energy giant Enron in 2001. The adoption of the new Basle Accord (better known as Basle II in 2001 envisaged the implementation of stress tests for the identification of events and future changes in economic circumstances that could cause some unfavorable effects on banks' credit exposure, along with the assessment of banks' ability to survive in the new circumstances. Negative experiences from the past, having undermined the stability of financial systems worldwide, made a decisive impact on regulators at all levels to additionally consider the issue of increasing the financial system's resistance to the occurrence of unexpected - exceptional events. To this end, the introduction of stress tests was the turning point in the process of increased banking systems' resistance to shocks. This paper primarily deals with stress testing methodology and bank risk measurement techniques, along with the main results of conducted tests, directly impacting the entire financial system.

  13. Stress Testing with Student's t Dependence

    NARCIS (Netherlands)

    H.J.W.G. Kole (Erik); C.G. Koedijk (Kees); M.J.C.M. Verbeek (Marno)

    2003-01-01

    textabstractIn this study we propose the use of the Student's t dependence function to model dependence between asset returns when conducting stress tests. To properly include stress testing in a risk management system, it is important to have accurate information about the (joint) probabilities of

  14. Accelerated Stress-Corrosion Testing

    Science.gov (United States)

    1986-01-01

    Test procedures for accelerated stress-corrosion testing of high-strength aluminum alloys faster and provide more quantitative information than traditional pass/fail tests. Method uses data from tests on specimen sets exposed to corrosive environment at several levels of applied static tensile stress for selected exposure times then subsequently tensile tested to failure. Method potentially applicable to other degrading phenomena (such as fatigue, corrosion fatigue, fretting, wear, and creep) that promote development and growth of cracklike flaws within material.

  15. Residual Stress Testing of Outer 3013 Containers

    International Nuclear Information System (INIS)

    Dunn, K.

    2004-01-01

    A Gas Tungsten Arc Welded (GTAW) outer 3013 container and a laser welded outer 3013 container have been tested for residual stresses according to the American Society for Testing Materials (ASTM) Standard G-36-94 [1]. This ASTM standard describes a procedure for conducting stress-corrosion cracking tests in boiling magnesium chloride (MgCl2) solution. Container sections in both the as-fabricated condition as well as the closure welded condition were evaluated. Significantly large residual stresses were observed in the bottom half of the as-fabricated container, a result of the base to can fabrication weld because through wall cracks were observed perpendicular to the weld. This observation indicates that regardless of the closure weld technique, sufficient residual stresses exist in the as-fabricated container to provide the stress necessary for stress corrosion cracking of the container, at the base fabrication weld. Additionally, sufficiently high residual stresses were observed in both the lid and the body of the GTAW as well as the laser closure welded containers. The stresses are oriented perpendicular to the closure weld in both the container lid and the container body. Although the boiling MgCl2 test is not a quantitative test, a comparison of the test results from the closure welds shows that there are noticeably more through wall cracks in the laser closure welded container than in the GTAW closure welded container

  16. Stress Tests and Vulnerability Assessment

    International Nuclear Information System (INIS)

    Wallner, A.; Lorenz, P.

    2012-01-01

    After the accident in Fukushima, nuclear safety as topic in anti-nuclear work has gained importance within the Joint Project countries. Therefore, nuclear safety and in particular the activities of the European stress tests were chosen to be the main focus of the Joint Project 2011/2012 as well as the common theme of the national projects. This brochure describes: A) Vulnerability Assessment A critical review of the EU Nuclear Stress Tests in Bulgaria, Hungary, Romania and Ukraine is presented in chapter 1. The review details the main weaknesses identified within the stress tests. Important shortcomings not mentioned in the stress tests reports are also discussed. These evaluations do not claim to be exhaustive, but the findings contribute to a more comprehensive understanding of safety and risk of nuclear power plants in Europe. B) Transparency of the stress tests In chapter 2 the experience of the Joint Project NGOs concerning transparency of the stress tests is presented. The information is not meant to be an evaluation of the transparency of the stress tests in general – such an evaluation is not possible within the scope of this brochure. The evaluation aims to show activities concerning stress tests and how they were conceived by the JP NGOs. Some recommendations for improvement are given. C) Safety focus Within the main topic “nuclear safety” of the Joint Project 2011/2012 the NGOs of each JP country selected a special safety relevant topic, which is/was of particular interest in their country: Bulgaria: The short story of Belene NPP – The victory – Key points of the campaign against the nuclear power plant Romania: Risks of the CANDU reactor design Czech Republic: Results of the conference “Power Plant Load Testing: Safety Inspection or Propaganda?“ Slovakia: Safety deficits of the NPP Mochovce These safety relevant issues are discussed in separate sections within the brochure at hand. (author)

  17. Stress Tests and Vulnerability Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Wallner, A. [Austrian Institute of Ecology, Vienna (Austria); Lorenz, P. [ed.; Becker, O. [eds.; Weber, U. [Austrian Institute of Ecology, Vienna (Austria)

    2012-07-01

    After the accident in Fukushima, nuclear safety as topic in anti-nuclear work has gained importance within the Joint Project countries. Therefore, nuclear safety and in particular the activities of the European stress tests were chosen to be the main focus of the Joint Project 2011/2012 as well as the common theme of the national projects. This brochure describes: A) Vulnerability Assessment A critical review of the EU Nuclear Stress Tests in Bulgaria, Hungary, Romania and Ukraine is presented in chapter 1. The review details the main weaknesses identified within the stress tests. Important shortcomings not mentioned in the stress tests reports are also discussed. These evaluations do not claim to be exhaustive, but the findings contribute to a more comprehensive understanding of safety and risk of nuclear power plants in Europe. B) Transparency of the stress tests In chapter 2 the experience of the Joint Project NGOs concerning transparency of the stress tests is presented. The information is not meant to be an evaluation of the transparency of the stress tests in general – such an evaluation is not possible within the scope of this brochure. The evaluation aims to show activities concerning stress tests and how they were conceived by the JP NGOs. Some recommendations for improvement are given. C) Safety focus Within the main topic “nuclear safety” of the Joint Project 2011/2012 the NGOs of each JP country selected a special safety relevant topic, which is/was of particular interest in their country: Bulgaria: The short story of Belene NPP – The victory – Key points of the campaign against the nuclear power plant Romania: Risks of the CANDU reactor design Czech Republic: Results of the conference “Power Plant Load Testing: Safety Inspection or Propaganda?“ Slovakia: Safety deficits of the NPP Mochovce These safety relevant issues are discussed in separate sections within the brochure at hand. (author)

  18. Scintigraphic ventriculography and stress testing

    International Nuclear Information System (INIS)

    Goris, M.L.; Hung, J.; Debusk, R.F.

    1982-01-01

    Scintigraphic stress ventriculography yields information which is complex and defies description by the difference in ejection fraction between rest and maximum exercise only. The complexity results in part from the ''derived'' nature of the ejection fraction measurement, which is physiologically secondary to stroke volume and end-diastolic volume. Furthermore, the nature of the stress test in which the pulse (stress) is not independent from the response forces an analysis which considers ''when'' as much as ''what'' happens. Automation in data processing, however, has made oversimplification unnecessary and allows a more exhaustive but correct analysis

  19. Testing the stress shadow hypothesis

    Science.gov (United States)

    Felzer, Karen R.; Brodsky, Emily E.

    2005-05-01

    A fundamental question in earthquake physics is whether aftershocks are predominantly triggered by static stress changes (permanent stress changes associated with fault displacement) or dynamic stresses (temporary stress changes associated with earthquake shaking). Both classes of models provide plausible explanations for earthquake triggering of aftershocks, but only the static stress model predicts stress shadows, or regions in which activity is decreased by a nearby earthquake. To test for whether a main shock has produced a stress shadow, we calculate time ratios, defined as the ratio of the time between the main shock and the first earthquake to follow it and the time between the last earthquake to precede the main shock and the first earthquake to follow it. A single value of the time ratio is calculated for each 10 × 10 km bin within 1.5 fault lengths of the main shock epicenter. Large values of the time ratio indicate a long wait for the first earthquake to follow the main shock and thus a potential stress shadow, whereas small values indicate the presence of aftershocks. Simulations indicate that the time ratio test should have sufficient sensitivity to detect stress shadows if they are produced in accordance with the rate and state friction model. We evaluate the 1989 MW 7.0 Loma Prieta, 1992 MW 7.3 Landers, 1994 MW 6.7 Northridge, and 1999 MW 7.1 Hector Mine main shocks. For each main shock, there is a pronounced concentration of small time ratios, indicating the presence of aftershocks, but the number of large time ratios is less than at other times in the catalog. This suggests that stress shadows are not present. By comparing our results to simulations we estimate that we can be at least 98% confident that the Loma Prieta and Landers main shocks did not produce stress shadows and 91% and 84% confident that stress shadows were not generated by the Hector Mine and Northridge main shocks, respectively. We also investigate the long hypothesized existence

  20. Advanced Testing Method for Ground Thermal Conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaobing [ORNL; Clemenzi, Rick [Geothermal Design Center Inc.; Liu, Su [University of Tennessee (UT)

    2017-04-01

    A new method is developed that can quickly and more accurately determine the effective ground thermal conductivity (GTC) based on thermal response test (TRT) results. Ground thermal conductivity is an important parameter for sizing ground heat exchangers (GHEXs) used by geothermal heat pump systems. The conventional GTC test method usually requires a TRT for 48 hours with a very stable electric power supply throughout the entire test. In contrast, the new method reduces the required test time by 40%–60% or more, and it can determine GTC even with an unstable or intermittent power supply. Consequently, it can significantly reduce the cost of GTC testing and increase its use, which will enable optimal design of geothermal heat pump systems. Further, this new method provides more information about the thermal properties of the GHEX and the ground than previous techniques. It can verify the installation quality of GHEXs and has the potential, if developed, to characterize the heterogeneous thermal properties of the ground formation surrounding the GHEXs.

  1. 77 FR 60948 - Stress Testing of Regulated Entities

    Science.gov (United States)

    2012-10-05

    ... regulated by a primary federal financial regulatory agency, to conduct annual stress tests to determine... the regulated entities under the Federal Housing Enterprises Financial Safety and Soundness Act of... regulated by a primary Federal financial regulatory agency shall conduct annual stress tests * * * (emphasis...

  2. Stress Testing as a Tool of Bank Risk Management

    Directory of Open Access Journals (Sweden)

    Antonyuk Oksana I.

    2013-12-01

    Full Text Available The goal of the article is development of theoretical, methodological and practical recommendations on the use of stress testing by Ukrainian commercial banks. Stress testing is defined as a part of bank risk management on the basis of scientific studies of domestic and foreign scientists. The article marks the essence of the bank stress testing and identifies its role in the structure of banks’ risk management in Ukraine. It considers goals of conducting stress testing in banking institutions. It identifies main aspects and specific features of conducting stress testing of bank risks. It characterises main advantages and shortcomings of use of stress testing in the modern bank risk management. It generalises the world and European approaches to the methods of conducting stress testing in commercial banks in comparison with the Ukrainian methodical recommendations. It shows that results of stress testing have practical value, since they help to preliminary assess influence of potentially negative events upon the state of the loan portfolio of the bank and make relevant managerial decisions.

  3. Biaxial Stress Tests of Plain Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.K.; Cho, M.S.; Song, Y.C. [Korea Electric Power Research Institute, Taejon (Korea)

    2001-07-01

    Containment concrete specimens(4000, 5000psi) were tested under biaxial stress and presented basic physical properties and biaxial failure envelops for the concrete specimens. Failure behaviors of concrete under biaxial stress were assessed with stress-strain responses and failure modes. Here provided real test data to develop nonlinear finite element concrete models. (author). 15 refs., 46 figs., 4 tabs.

  4. Modeling conductive cooling for thermally stressed dairy cows.

    Science.gov (United States)

    Gebremedhin, Kifle G; Wu, Binxin; Perano, K

    2016-02-01

    Conductive cooling, which is based on direct contact between a cow lying down and a cooled surface (water mattress, or any other heat exchanger embedded under the bedding), allows heat transfer from the cow to the cooled surface, and thus alleviate heat stress of the cow. Conductive cooling is a novel technology that has the potential to reduce the consumption of energy and water in cooling dairy cows compared to some current practices. A three-dimensional conduction model that simulates cooling thermally-stressed dairy cows was developed. The model used a computational fluid dynamics (CFD) method to characterize the air-flow field surrounding the animal model. The flow field was obtained by solving the continuity and the momentum equations. The heat exchange between the animal and the cooled water mattress as well as between the animal and ambient air was determined by solving the energy equation. The relative humidity was characterized using the species transport equation. The conduction 3-D model was validated against experimental temperature data and the agreement was very good (average error is 4.4% and the range is 1.9-8.3%) for a mesh size of 1117202. Sensitivity analyses were conducted between heat losses (sensible and latent) with respect to air temperature, relative humidity, air velocity, and level of wetness of skin surface to determine which of the parameters affect heat flux more than others. Heat flux was more sensitive to air temperature and level of wetness of the skin surface and less sensitive to relative humidity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. 49 CFR 40.211 - Who conducts DOT alcohol tests?

    Science.gov (United States)

    2010-10-01

    ...) Screening test technicians (STTs) and breath alcohol technicians (BATs) meeting their respective... conduct only alcohol screening tests, but a BAT can conduct alcohol screening and confirmation tests. (c) As a BAT- or STT-qualified immediate supervisor of a particular employee, you may not act as the STT...

  6. Stress testing - ettevaatliku investori abimees / Peeter Teder

    Index Scriptorium Estoniae

    Teder, Peeter

    2005-01-01

    Autor selgitab stress testingut kui investeerimisportfelli varade väärtuse hindamist ning tutvustab selle võimalusi ja ohtusid. Diagrammid: Portfelli testimis-stsenaariumiks sobivad hästi börsikrahhid. Vt. samas: Stress testing toimib ka mujal

  7. 77 FR 62396 - Annual Company-Run Stress Test Requirements for Banking Organizations With Total Consolidated...

    Science.gov (United States)

    2012-10-12

    ... minimum risk-based capital requirements.\\3\\ Stress testing is one tool that helps both bank supervisors... the FDIC and the OCC to help to ensure that the company-run stress testing regulations are consistent... purposes of the annual company-run stress tests so that the same set of scenarios can be used to conduct...

  8. Benchmark Tests for Stirling Convertor Heater Head Life Assessment Conducted

    Science.gov (United States)

    Krause, David L.; Halford, Gary R.; Bowman, Randy R.

    2004-01-01

    A new in-house test capability has been developed at the NASA Glenn Research Center, where a critical component of the Stirling Radioisotope Generator (SRG) is undergoing extensive testing to aid the development of analytical life prediction methodology and to experimentally aid in verification of the flight-design component's life. The new facility includes two test rigs that are performing creep testing of the SRG heater head pressure vessel test articles at design temperature and with wall stresses ranging from operating level to seven times that (see the following photograph).

  9. Accelerated stress testing of terrestrial solar cells

    Science.gov (United States)

    Lathrop, J. W.; Hawkins, D. C.; Prince, J. L.; Walker, H. A.

    1982-01-01

    The development of an accelerated test schedule for terrestrial solar cells is described. This schedule, based on anticipated failure modes deduced from a consideration of IC failure mechanisms, involves bias-temperature testing, humidity testing (including both 85-85 and pressure cooker stress), and thermal-cycle thermal-shock testing. Results are described for 12 different unencapsulated cell types. Both gradual electrical degradation and sudden catastrophic mechanical change were observed. These effects can be used to discriminate between cell types and technologies relative to their reliability attributes. Consideration is given to identifying laboratory failure modes which might lead to severe degradation in the field through second quadrant operation. Test results indicate that the ability of most cell types to withstand accelerated stress testing depends more on the manufacturer's design, processing, and worksmanship than on the particular metallization system. Preliminary tests comparing accelerated test results on encapsulated and unencapsulated cells are described.

  10. Adaptation of electrical conductivity test for Moringa oleifera seeds

    Directory of Open Access Journals (Sweden)

    Maria Luiza de Souza Medeiros

    2017-09-01

    Full Text Available This study aimed to adapt and test the efficiency of electrical conductivity methodology test in quality evaluation of Moringa oleifera Lam seeds. For physiological characterization four seed sets were evaluated by tests of germination, seedlings emergency, speed of emergency index, emergency first count, seedlings length and dry mass and cold test. The electrical conductivity test was carried out at 25 °C for 4, 8, 12, 16 and 24 h of immersion in 75 or 125 mL of distilled water using 25 or 50 seeds. A completely randomized design was used. The best results were obtained when using 50 seeds immersed in 75 mL or 125 mL of distilled water for 4 h. The electrical conductivity test adapted to moringa seeds was efficient in ranking sets of different vigor levels. The test may be efficiently used for physiological quality evaluation of moringa seeds.

  11. Test design requirements for overcoring stress measurements

    International Nuclear Information System (INIS)

    Stickney, R.G.

    1985-12-01

    This document establishes the test design requirements for a series of overcoring stress measurements to be performed in the Exploratory Shaft Facility. The stress measurements will be made to determine the in situ state of stress within the candidate repository horizon and to determine the magnitude and distribution of the stresses induced by the mined openings of the facility. The overcoring technique involves the measurement of strain (or deformation) in a volume of rock as the stress acting on the rock volume is relieved. This document presents an overview of the measurements, including objectives and rationale for the measurements. A description of the measurements is included. The support requirements are identified as are constraints for the design of the measurements. Discussions on Quality Assurance and Safety are also included in the document. 13 refs

  12. Liquid salt environment stress-rupture testing

    Science.gov (United States)

    Ren, Weiju; Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

    2016-03-22

    Disclosed herein are systems, devices and methods for stress-rupture testing selected materials within a high-temperature liquid salt environment. Exemplary testing systems include a load train for holding a test specimen within a heated inert gas vessel. A thermal break included in the load train can thermally insulate a load cell positioned along the load train within the inert gas vessel. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during stress-rupture testing. The gage portion can have an inner surface area to volume ratio of greater than 20 to maximize the corrosive effect of the molten salt on the specimen material during testing. Also disclosed are methods of making a salt ingot for placement within the test specimen.

  13. Thermal conductivity tests on buffermasses of bentonite/silt

    International Nuclear Information System (INIS)

    Knutsson, S.

    1977-09-01

    The investigation concerns the thermal conductivity of the bentonite/quartz buffer mass suggested as embedding substance for radioactive canisters. The first part presents the theoretical relationships associated with the various heat transfer mechanisms in moist granular materials. Chapter 3 describes the author's experimental determination of the thermal conductivity of the buffer mass. The tested mass consisted of 10 percent (by weight) bentonite and 90 percent natural silt. Four tests were made with different water content values and degree of water saturation. A comparison between the measured and calculated thermal conductivities is given. It is shown that the conductivity can be calculated with an accuracy of +-20 percent. (author)

  14. Stress corrosion testing of irradiated cladding tubes

    International Nuclear Information System (INIS)

    Lunde, L.; Olshausen, K.D.

    1980-01-01

    Samples from two fuel rods with different cladding have been stress corrosion tested by closed-end argon-iodine pressurization at 320 0 C. The fuel rods with stress relieved and recrystallized Zircaloy-2 had received burnups of 10.000 and 20.000 MWd/ton UO 2 , respectively. It was found that the SCC failure stress was unchanged or slightly higher for the irradiated than for the unirradiated control tubes. The tubes failed consistently in the end with the lowest irradiation dose. The diameter increase of the irradiated cladding during the test was 1.1% for the stress-relieved samples and 0.24% for the recrystallized samples. SEM examination revealed no major differences between irradiated and unirradiated cladding. A ''semi-ductile'' fracture zone in recrystallized material is described in some detail. (author)

  15. Time, stress, and temperature-dependent deformation in nanostructured copper: Stress relaxation tests and simulations

    International Nuclear Information System (INIS)

    Yang, Xu-Sheng; Wang, Yun-Jiang; Wang, Guo-Yong; Zhai, Hui-Ru; Dai, L.H.; Zhang, Tong-Yi

    2016-01-01

    In the present work, stress relaxation tests, high-resolution transmission electron microscopy (HRTEM), and molecular dynamics (MD) simulations were conducted on coarse-grained (cg), nanograined (ng), and nanotwinned (nt) copper at temperatures of 22 °C (RT), 30 °C, 40 °C, 50 °C, and 75 °C. The comprehensive investigations provide sufficient information for the building-up of a formula to describe the time, stress, and temperature-dependent deformation and clarify the relationship among the strain rate sensitivity parameter, stress exponent, and activation volume. The typically experimental curves of logarithmic plastic strain rate versus stress exhibited a three staged relaxation process from a linear high stress relaxation region to a subsequent nonlinear stress relaxation region and finally to a linear low stress relaxation region, which only showed-up at the test temperatures higher than 22 °C, 22 °C, and 30 °C, respectively, in the tested cg-, ng-, and nt-Cu specimens. The values of stress exponent, stress-independent activation energy, and activation volume were determined from the experimental data in the two linear regions. The determined activation parameters, HRTEM images, and MD simulations consistently suggest that dislocation-mediated plastic deformation is predominant in all tested cg-, ng-, and nt-Cu specimens in the initial linear high stress relaxation region at the five relaxation temperatures, whereas in the linear low stress relaxation region, the grain boundary (GB) diffusion-associated deformation is dominant in the ng- and cg-Cu specimens, while twin boundary (TB) migration, i.e., twinning and detwinning with parallel partial dislocations, governs the time, stress, and temperature-dependent deformation in the nt-Cu specimens.

  16. Triaxial Wetting Test on Rockfill Materials under Stress Combination Conditions of Spherical Stress p and Deviatoric Stress q

    Directory of Open Access Journals (Sweden)

    Yan-yi Zhang

    2018-01-01

    Full Text Available A GCTS medium-sized triaxial apparatus is used to conduct a single-line method wetting test on three kinds of rockfill materials of different mother rocks such as mixture of sandstone and slate, and dolomite and granite, and the test stress conditions is the combination of spherical stress p and deviatoric stress q. The test results show that (1 for wetting shear strain, the effects of spherical stress p and deviatoric stress q are equivalent, and wetting shear strain and deviatoric stress q show the power function relationship preferably. (2 For wetting volumetric strain, the effect of deviatoric stress q can be neglected because it is extremely insignificant, and spherical stress p is the main influencing factor and shows the power function relationship preferably. (3 The wetting strains decrease significantly with the increase in initial water content and sample density generally, but the excessively high dry density will increase the wetting deformation. Also, the wetting strains will decrease with the increase in the saturated uniaxial compressive strength and average softening coefficient of the mother rock. Based on the test results, a wetting strain model is proposed for rockfill materials. The verification results indicate that the model satisfactorily reflects the development law of wetting deformation.

  17. Identification of conductive hearing loss using air conduction tests alone: reliability and validity of an automatic test battery.

    Science.gov (United States)

    Convery, Elizabeth; Keidser, Gitte; Seeto, Mark; Freeston, Katrina; Zhou, Dan; Dillon, Harvey

    2014-01-01

    The primary objective of this study was to determine whether a combination of automatically administered pure-tone audiometry and a tone-in-noise detection task, both delivered via an air conduction (AC) pathway, could reliably and validly predict the presence of a conductive component to the hearing loss. The authors hypothesized that performance on the battery of tests would vary according to hearing loss type. A secondary objective was to evaluate the reliability and validity of a novel automatic audiometry algorithm to assess its suitability for inclusion in the test battery. Participants underwent a series of hearing assessments that were conducted in a randomized order: manual pure-tone air conduction audiometry and bone conduction audiometry; automatic pure-tone air conduction audiometry; and an automatic tone-in-noise detection task. The automatic tests were each administered twice. The ability of the automatic test battery to: (a) predict the presence of an air-bone gap (ABG); and (b) accurately measure AC hearing thresholds was assessed against the results of manual audiometry. Test-retest conditions were compared to determine the reliability of each component of the automatic test battery. Data were collected on 120 ears from normal-hearing and conductive, sensorineural, and mixed hearing-loss subgroups. Performance differences between different types of hearing loss were observed. Ears with a conductive component (conductive and mixed ears) tended to have normal signal to noise ratios (SNR) despite impaired thresholds in quiet, while ears without a conductive component (normal and sensorineural ears) demonstrated, on average, an increasing relationship between their thresholds in quiet and their achieved SNR. Using the relationship between these two measures among ears with no conductive component as a benchmark, the likelihood that an ear has a conductive component can be estimated based on the deviation from this benchmark. The sensitivity and

  18. Panel manipulation in social stress testing: The Bath Experimental Stress Test for Children (BEST-C).

    Science.gov (United States)

    Cheetham, Tara J; Turner-Cobb, Julie M

    2016-01-01

    Whilst acute stress paradigms in adults make use of adult panel members, similar paradigms modified for child participants have not manipulated the panel. Most work has utilised an audience of adult confederates, regardless of the age of the population being tested. The aim of this study was to trial a social stress test for children that provided a meaningful environment using age-matched child peers as panel actors. Thirty-three participants (7-11 years) underwent the Bath Experimental Stress Test for Children (BEST-C). Based on the Trier Social Stress Test (TSST), it comprises a shortened six-minute public speaking task and four-minute maths challenge. It differs from previous stress tests by using age-matched children on the panel, pre-recorded and presented as a live feed, and includes an expanded manipulation check of subjective experience. Salivary cortisol was assessed at four time points, pre-post stress testing; life events, daily hassles and coping strategies were measured through questionnaires. A simple numerical coding scheme was applied to post-test interview data. The BEST-C generated a typical stress and adaptation response in salivary cortisol (p=.032). Age and gender differences were observed during recovery. Cortisol responses mapped directly onto three distinct subjective response patterns: (i) expected response and recovery; (ii) expected response, no recovery; (iii) no response. The BEST-C, utilising child confederates of participant target age is a meaningful social stress test for children. This is the first social stress test developed specifically for children that manipulates panel characteristics by using child confederates and a pre-recorded sham panel. Greater cortisol responses to the test were also found to match subjective verbal accounts of the experience. It offers a meaningful acute stress paradigm with potential applications to other child and adolescent age groups. Furthermore, it leads the way in the use of panel manipulation

  19. Pad stress tests with increasing load for the diagnosis of stress urinary incontinence.

    Science.gov (United States)

    Rimstad, Liv; Larsen, Elsa Skjønhaug; Schiøtz, Hjalmar A; Kulseng-Hanssen, Sigurd

    2014-09-01

    The aim of the study was to test the ability of pad stress tests with increasing load (supine, jumping on the floor, and jumping on a trampoline) to document stress incontinence in subjectively stress incontinent women. In this prospective study 147 subjectively stress and mixed incontinent women performed consecutively the three pad stress tests with a bladder volume of 300 ml. Nineteen women performed a second trampoline pad stress test to test repeatability of the test. Nine continent women performed a trampoline pad stress test in order to determine if subjectively continent women would leak during the test. Seventy-two women (49%) leaked during the supine, 136 (93%) leaked during the jumping, and 146 (99%) leaked during the trampoline pad stress test. The differences between pad stress tests were significant with P trampoline pad stress tests was high at 0.8. None of the nine continent women leaked during the trampoline pad stress test. The supine pad stress test has low sensitivity and is therefore often falsely negative. The jumping pad stress test is a simple test to perform and is satisfactory for everyday use. Subjectively stress incontinent women who do not leak during the jumping pad stress test may perform a trampoline pad stress test to document stress incontinence. The trampoline pad stress test is also simple to perform and detected leakage in 91% of the women who did not leak during the jumping pad stress test. © 2013 Wiley Periodicals, Inc.

  20. Pretest Calculations of Temperature Changes for Field Thermal Conductivity Tests

    International Nuclear Information System (INIS)

    N.S. Brodsky

    2002-01-01

    A large volume fraction of the potential monitored geologic repository at Yucca Mountain may reside in the Tptpll (Tertiary, Paintbrush Group, Topopah Spring Tuff, crystal poor, lower lithophysal) lithostratigraphic unit. This unit is characterized by voids, or lithophysae, which range in size from centimeters to meters. A series of thermal conductivity field tests are planned in the Enhanced Characterization of the Repository Block (ECRB) Cross Drift. The objective of the pretest calculation described in this document is to predict changes in temperatures in the surrounding rock for these tests for a given heater power and a set of thermal transport properties. The calculation can be extended, as described in this document, to obtain thermal conductivity, thermal capacitance (density x heat capacity, J · m -3 · K -1 ), and thermal diffusivity from the field data. The work has been conducted under the ''Technical Work Plan For: Testing and Monitoring'' (BSC 2001). One of the outcomes of this analysis is to determine the initial output of the heater. This heater output must be sufficiently high that it will provide results in a reasonably short period of time (within several weeks or a month) and be sufficiently high that the heat increase is detectable by the instruments employed in the test. The test will be conducted in stages and heater output will be step increased as the test progresses. If the initial temperature is set too high, the experiment will not have as many steps and thus fewer thermal conductivity data points will result

  1. 77 FR 62417 - Annual Stress Test

    Science.gov (United States)

    2012-10-15

    ...;Prices of new books are listed in the first FEDERAL REGISTER issue of each #0;week. #0; #0; #0; #0;#0..., require a covered bank to report stress test results using a simpler format to be specified by the FDIC. G... Federal Register. Section 553(d)(3) of the Administrative Procedure Act (``APA'') provides that...

  2. Results of gap conductance tests in the power burst facility

    International Nuclear Information System (INIS)

    Garner, R.W.; Sparks, D.T.

    1977-01-01

    Light water reactor (LWR) fuel rod behavior studies are being conducted by the Thermal Fuels Behavior Program of EG and G Idaho, Inc. These studies are being performed under contract to the Energy Research and Development Adminstration at the Idaho National Engineering Laboratory (INEL), as part of the Nuclear Regulatory Commission's Water Reactor Safety Research Fuel Behavior Program. Experimental data for verification of analytical models developed to predict light water nuclear fuel rod behavior under normal and postulated accident conditions are being obtained from a variety of in-reactor and out-of-reactor experiments. This paper summarizes the results of tests performed in the Power Burst Facility (PBF) to obtain data from which the thermal response, gap conductance, and stored energy of LWR fuel rods can be determined. Primary objectives of the PBF gap conductance test program are (a) to obtain data on a variety of pressurized water reactor (PWR) and boiling water reactor (BWR) fuel rod designs, under a wide range of operating conditions, from which gap conductance values can be determined and (b) to evaluate experimentally the power oscillation method for measuring the gap conductance and thermal response of a fresh or burned LWR fuel rod. Tests have been performed with both irradiated and unirradiated PWR-type fuel and with fresh BWR-type fuel rods. Some PWR rod test results are described, and the thermal response data from BWR rod tests are discussed in greater detail. Comparisons are made of gap conductance values determined by the tests with analytically calculated values using the Fuel Rod Analysis Program-Transient (FRAP-T) computer code. These comparisons provide insight into both the experimental measurements methods and the validity of the gap conductance models

  3. Have you stress tested your assay?

    Directory of Open Access Journals (Sweden)

    Zheng Cao

    2016-08-01

    Full Text Available Objectives: When a clinical assay is stressed with extraordinarily high volume of specimens over a short period of time, extra caution may be needed to avoid systematic errors and biases. Here we report our experience with a HgbA1c assay used for high volume wellness screening purpose, to illustrate the importance of stress testing during assay validation. Design and Methods: Over 15,000 whole blood specimens were tested for HgbA1c in a period of 2 months. HgbA1c was tested by an immunoturbidimetric method on a high through-put automation line. The HgbA1c population distribution in our study was compared to that from the NHANES database. Daily distributions of HgbA1c values ≥6%, means and medians were plotted. Correlation studies were performed between the high through-put immunoturbidimetric assay and a medium through-put HPLC method. Results: We observed a shift of HgbA1c distribution to the higher values compared to the NHANES. A bias of 15–20% was noted from further stress testing where large number of samples were batched and tested using the immunoturbidimetric assay. A 5–7% higher bias remained after implementing a cuvette washing program after each HgbA1c sample. We hypothesized this bias was caused by build-up of blood cell fragments in the cuvettes when continuous whole blood samples are run through the system. Our experience suggests stress testing needs to be incorporated early in the test validation process for high volume batched screening applications. This seemingly extra validation step may save significant troubleshooting and retesting efforts down the road. Keywords: Hemoglobin A1c, Immunoturbidimetric assay, HPLC, Quality assurance, Systematic bias, High volume, Automation

  4. Analysis of slug tests in formations of high hydraulic conductivity.

    Science.gov (United States)

    Butler, James J; Garnett, Elizabeth J; Healey, John M

    2003-01-01

    A new procedure is presented for the analysis of slug tests performed in partially penetrating wells in formations of high hydraulic conductivity. This approach is a simple, spreadsheet-based implementation of existing models that can be used for analysis of tests from confined or unconfined aquifers. Field examples of tests exhibiting oscillatory and nonoscillatory behavior are used to illustrate the procedure and to compare results with estimates obtained using alternative approaches. The procedure is considerably simpler than recently proposed methods for this hydrogeologic setting. Although the simplifications required by the approach can introduce error into hydraulic-conductivity estimates, this additional error becomes negligible when appropriate measures are taken in the field. These measures are summarized in a set of practical field guidelines for slug tests in highly permeable aquifers.

  5. Conductivity Profile Determination by Eddy Current for Shot Peened Superalloy Surfaces Toward Residual Stress Assessment

    International Nuclear Information System (INIS)

    Shen, Y.; Lo, C. C. H.; Frishman, A. M.; Lee, C.; Nakagawa, N.

    2007-01-01

    This paper describes an eddy current model-based method for inverting near-surface conductivity deviation profiles of surface treated materials from swept-high frequency eddy current (SHFEC) data. This work forms part of our current research directed towards the development of an electromagnetic nondestructive technique for assessing residual stress of shot-peened superalloy components. The inversion procedure is based on the use of a parameterized function to describe the near-surface conductivity as a function of depth for a shot-peened surface, and the laterally uniform multi-layer theory of Cheng, Dodd and Deeds to calculate the resulting coil impedance deviations. The convergence of the inversion procedure has been tested against synthesized eddy current data. As a demonstration, the conductivity deviation profiles of a series of Inconel 718 specimens, shot peened at various Almen intensities, have been obtained by inversion. Several consistency tests were conducted to examine the reliability of the inverted conductivity profiles. The results show that conductivity deviation profiles can be reliably determined from SHFEC data within the accuracy of the current measurement system

  6. Conducting tests for statistically significant differences using forest inventory data

    Science.gov (United States)

    James A. Westfall; Scott A. Pugh; John W. Coulston

    2013-01-01

    Many forest inventory and monitoring programs are based on a sample of ground plots from which estimates of forest resources are derived. In addition to evaluating metrics such as number of trees or amount of cubic wood volume, it is often desirable to make comparisons between resource attributes. To properly conduct statistical tests for differences, it is imperative...

  7. An improved method for interpreting API filter press hydraulic conductivity test results

    International Nuclear Information System (INIS)

    Heslin, G.M.; Baxter, D.Y.; Filz, G.M.; Davidson, R.R.

    1997-01-01

    The American Petroleum Institute (API) filter press is frequently used to measure the hydraulic conductivity of soil-bentonite backfill during the mix design process and as part of construction quality controls. However, interpretation of the test results is complicated by the fact that the seepage-induced consolidation pressure varies from zero at the top of the specimen to a maximum value at the bottom of the specimen. An analytical solution is available which relates the stress, compressibility, and hydraulic conductivity in soil consolidated by seepage forces. This paper presents the results of a laboratory investigation undertaken to support application of this theory to API hydraulic conductivity tests. When the API test results are interpreted using seepage consolidation theory, they are in good agreement with the results of consolidometer permeameter tests. Limitations of the API test are also discussed

  8. Interpretation of the tracer testing conducted in the Leuggern borehole

    International Nuclear Information System (INIS)

    McNeish, J.A.; Andrews, R.W.; Vomvoris, S.

    1990-12-01

    Tracer testing was conducted in the Leuggern borehole from July to December 1988 to evaluate the hydraulic properties of the crystalline host rock. The tested interval was an approximately 50 m section of fractured crystalline rock at a depth of greater than 1,600 m. The testing consisted of three tracer injection/recovery periods (uranin - 44 days, eosin - 30 days, and naphtionat -14 days), which utilized tracer injection/circulation rates, ranging between 25 and 50 ml/min. During these testing periods, tracer was injected in either of two 1/4 flow lines ported at the top or bottom of the interval and recovered from the other. Following the three tracer injection periods, a natural outflow tracer recovery test was conducted from the central tubing at an average outflow of 12 l/min. The central tubing was ported near the center of the test interval. Data collected during the testing periods included: continuous monitoring of fluid temperature, injection pressure, and electrical conductivity as well as discrete measurement of flow rates, electrical conductivity, fluid temperature, and tracer concentration. Testing results indicate a downward vertical flow of approximately 195-225 ml/min in the isolated interval, from an upper fracture inflow zone to a lower fracture outflow zone. Through analysis of the dilution levels of uranin and eosin during the injection/recovery periods, and review of field data, the top of the upper inflow zone was determined to be approximately 13 m below the top flow line and the bottom of the outflow zone to be approximately 3 to 5 meters above the bottom flow line. The calculated transmissivity value of 6E-05 m 2 /s from observed outflow rate and pressure recovery data, is consistent with results derived from previous hydraulic packer testing in the interval. The effective porosity was determined to be 0.1. Dispersion coefficient values ranged from 1.0 m to 5.0 m. The lateral hydraulic gradient value calculated from tracer recovery

  9. Initial Mechanical Testing of Superalloy Lattice Block Structures Conducted

    Science.gov (United States)

    Krause, David L.; Whittenberger, J. Daniel

    2002-01-01

    The first mechanical tests of superalloy lattice block structures produced promising results for this exciting new lightweight material system. The testing was performed in-house at NASA Glenn Research Center's Structural Benchmark Test Facility, where small subelement-sized compression and beam specimens were loaded to observe elastic and plastic behavior, component strength levels, and fatigue resistance for hundreds of thousands of load cycles. Current lattice block construction produces a flat panel composed of thin ligaments arranged in a three-dimensional triangulated trusslike structure. Investment casting of lattice block panels has been developed and greatly expands opportunities for using this unique architecture in today's high-performance structures. In addition, advances made in NASA's Ultra-Efficient Engine Technology Program have extended the lattice block concept to superalloy materials. After a series of casting iterations, the nickel-based superalloy Inconel 718 (IN 718, Inco Alloys International, Inc., Huntington, WV) was successfully cast into lattice block panels; this combination offers light weight combined with high strength, high stiffness, and elevated-temperature durability. For tests to evaluate casting quality and configuration merit, small structural compression and bend test specimens were machined from the 5- by 12- by 0.5-in. panels. Linear elastic finite element analyses were completed for several specimen layouts to predict material stresses and deflections under proposed test conditions. The structural specimens were then subjected to room-temperature static and cyclic loads in Glenn's Life Prediction Branch's material test machine. Surprisingly, the test results exceeded analytical predictions: plastic strains greater than 5 percent were obtained, and fatigue lives did not depreciate relative to the base material. These assets were due to the formation of plastic hinges and the redundancies inherent in lattice block construction

  10. Standard Guide for Conducting Corrosion Tests in Field Applications

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This guide covers procedures for conducting corrosion tests in plant equipment or systems under operating conditions to evaluate the corrosion resistance of engineering materials. It does not cover electrochemical methods for determining corrosion rates. 1.1.1 While intended primarily for immersion tests, general guidelines provided can be applicable for exposure of test specimens in plant atmospheres, provided that placement and orientation of the test specimens is non-restrictive to air circulation. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. See also 10.4.2.

  11. Standard guide for conducting exfoliation corrosion tests in aluminum alloys

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1992-01-01

    1.1 This guide differs from the usual ASTM standard in that it does not address a specific test. Rather, it is an introductory guide for new users of other standard exfoliation test methods, (see Terminology G 15 for definition of exfoliation). 1.2 This guide covers aspects of specimen preparation, exposure, inspection, and evaluation for conducting exfoliation tests on aluminum alloys in both laboratory accelerated environments and in natural, outdoor atmospheres. The intent is to clarify any gaps in existent test methods. 1.3 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  12. Testing Conducted for Lithium-Ion Cell and Battery Verification

    Science.gov (United States)

    Reid, Concha M.; Miller, Thomas B.; Manzo, Michelle A.

    2004-01-01

    The NASA Glenn Research Center has been conducting in-house testing in support of NASA's Lithium-Ion Cell Verification Test Program, which is evaluating the performance of lithium-ion cells and batteries for NASA mission operations. The test program is supported by NASA's Office of Aerospace Technology under the NASA Aerospace Flight Battery Systems Program, which serves to bridge the gap between the development of technology advances and the realization of these advances into mission applications. During fiscal year 2003, much of the in-house testing effort focused on the evaluation of a flight battery originally intended for use on the Mars Surveyor Program 2001 Lander. Results of this testing will be compared with the results for similar batteries being tested at the Jet Propulsion Laboratory, the Air Force Research Laboratory, and the Naval Research Laboratory. Ultimately, this work will be used to validate lithium-ion battery technology for future space missions. The Mars Surveyor Program 2001 Lander battery was characterized at several different voltages and temperatures before life-cycle testing was begun. During characterization, the battery displayed excellent capacity and efficiency characteristics across a range of temperatures and charge/discharge conditions. Currently, the battery is undergoing lifecycle testing at 0 C and 40-percent depth of discharge under low-Earth-orbit (LEO) conditions.

  13. Thermography Used to Test Conductivity of Carbon Based Cloth

    Science.gov (United States)

    Craven, Paul

    2012-01-01

    Testing of the ability of carbon fiber to radiatively cool a heat source. The carbon fibers are attached to a heat source. The heat conducts into the fiber than along the fiber away from the heat source. The test are done in a vacuum chamber (10-5 Torr typical). The IR camera is viewing the fiber through a ZnSe window. A thermocouple (TC) in contact with the fiber is at the top right hand side of the area of interest and one is near the bottom. Thin shielding fins, seen edge on, are just above the top thermocouple.

  14. Coupled heat conduction and thermal stress formulation using explicit integration

    International Nuclear Information System (INIS)

    Marchertas, A.H.; Kulak, R.F.

    1982-06-01

    The formulation needed for the conductance of heat by means of explicit integration is presented. The implementation of these expressions into a transient structural code, which is also based on explicit temporal integration, is described. Comparisons of theoretical results with code predictions are given both for one-dimensional and two-dimensional problems. The coupled thermal and structural solution of a concrete crucible, when subjected to a sudden temperature increase, shows the history of cracking. The extent of cracking is compared with experimental data

  15. An acceleration test for stress corrosion cracking using humped specimen

    International Nuclear Information System (INIS)

    Kamaya, Masayuki; Fukumura, Takuya; Totsuka, Nobuo

    2003-01-01

    By using the humped specimen, which is processed by the humped die, in the slow strain rate technique (SSRT) test, fracture facet due to stress corrosion cracking (SCC) can be observed in relatively short duration. Although the cold work and concentrated stress and strain caused by the characteristic shape of the specimen accelerate the SCC, to date these acceleration effects have not been examined quantitatively. In the present study, the acceleration effects of the humped specimen were examined through experiments and finite element analyses (FEA). The experiments investigated the SCC of alloy 600 in the primary water environment of a pressurized water reactor. SSRT tests were conducted using two kinds of humped specimen: one was annealed after hump processing in order to eliminate the cold work, and the other was hump processed after the annealing treatment. The work ratio caused by the hump processing and stress/strain conditions during SSRT test were evaluated by FEA. It was found that maximum work ratio of 30% is introduced by the hump processing and that the distribution of the work ratio is not uniform. Furthermore, the work ratio is influenced by the friction between the specimen and dies as well as by the shape of dies. It was revealed that not only the cold work but also the concentrated stress and strain during SSRT test accelerate the crack initiation and growth of the SCC. (author)

  16. Standard practice for conducting atmospheric corrosion tests on metals

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice covers and defines conditions for exposure of metals and alloys to the weather. It sets forth the general procedures that should be followed in any atmospheric test. It is presented as an aid in conducting atmospheric corrosion tests so that some of the pitfalls of such testing may be avoided. As such, it is concerned mainly with panel exposures to obtain data for comparison purposes. 1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  17. Conduct disorder, war zone stress, and war-related posttraumatic stress disorder symptoms in American Indian Vietnam veterans.

    Science.gov (United States)

    Dillard, Denise; Jacobsen, Clemma; Ramsey, Scott; Manson, Spero

    2007-02-01

    This study examined whether conduct disorder (CD) was associated with war zone stress and war-related post-traumatic stress disorder (PTSD) symptoms in American Indian (AI) Vietnam veterans. Cross-sectional lay-interview data was analyzed for 591 male participants from the American Indian Vietnam Veterans Project. Logistic regression evaluated the association of CD with odds of high war zone stress and linear regression evaluated the association of CD and PTSD symptom severity. Childhood CD was not associated with increased odds of high war zone stress. Conduct disorder was associated with elevated war-related PTSD symptoms among male AI Vietnam Veterans independent of war zone stress level and other mediators. Future efforts should examine reasons for this association and if the association exists in other AI populations.

  18. 40 CFR 90.329 - Catalyst thermal stress test.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Catalyst thermal stress test. 90.329... Equipment Provisions § 90.329 Catalyst thermal stress test. (a) Oven characteristics. The oven used for thermally stressing the test catalyst must be capable of maintaining a temperature of 500 ±5 °C and 1000 ±10...

  19. 40 CFR 91.329 - Catalyst thermal stress test.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Catalyst thermal stress test. 91.329....329 Catalyst thermal stress test. (a) Oven characteristics. The oven used for termally stressing the test catalyst must be capable of maintaining a temperature of 500 ±5 °C and 1000 ±10 °C. (b) Evaluation...

  20. Flexural Capability of Patterned Transparent Conductive Substrate by Performing Electrical Measurements and Stress Simulations

    Directory of Open Access Journals (Sweden)

    Chang-Chun Lee

    2016-10-01

    Full Text Available The suitability of stacked thin films for next-generation display technology was analyzed based on their properties and geometrical designs to evaluate the mechanical reliability of transparent conducting thin films utilized in flexural displays. In general, the high bending stress induced by various operation conditions is a major concern regarding the mechanical reliability of indium–tin–oxide (ITO films deposited on polyethylene terephthalate (PET substrates; mechanical reliability is commonly used to estimate the flexibility of displays. However, the pattern effect is rarely investigated to estimate the mechanical reliability of ITO/PET films. Thus, this study examined the flexible content of patterned ITO/PET films with two different line widths by conducting bending tests and sheet resistance measurements. Moreover, a stress–strain simulation enabled by finite element analysis was performed on the patterned ITO/PET to explore the stress impact of stacked film structures under various levels of flexural load. Results show that the design of the ITO/PET film can be applied in developing mechanically reliable flexible electronics.

  1. Boys with Oppositional Defiant Disorder/Conduct Disorder Show Impaired Adaptation During Stress: An Executive Functioning Study.

    Science.gov (United States)

    Schoorl, Jantiene; van Rijn, Sophie; de Wied, Minet; van Goozen, Stephanie; Swaab, Hanna

    2018-04-01

    Evidence for problems in executive functioning (EF) in children with oppositional defiant disorder/conduct disorder (ODD/CD) is mixed and the impact stress may have on EF is understudied. Working memory, sustained attention, inhibition and cognitive flexibility of boys with ODD/CD (n = 65) and non-clinical controls (n = 32) were examined under typical and stressful test conditions. Boys with ODD/CD showed impaired working memory under typical testing conditions, and impairments in working memory and sustained attention under stressful conditions. In contrast to controls, performance on sustained attention, cognitive flexibility and inhibition was less influenced by stress in boys with ODD/CD. These results suggest that boys with ODD/CD show impairments in adaptation to the environment whereas typically developing boys show adaptive changes in EF.

  2. Standard practice for conducting moist SO2 tests

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2002-01-01

    1.1 This practice covers the apparatus and procedure to be used in conducting qualitative assessment tests in accordance with the requirements of material or product specifications by means of specimen exposure to condensed moisture containing sulfur dioxide. 1.2 The exposure conditions may be varied to suit particular requirements and this practice includes provisions for use of different concentrations of sulfur dioxide and for tests either running continuously or in cycles of alternate exposure to the sulfur dioxide containing atmosphere and to the ambient atmosphere. 1.3 The variant of the test to be used, the exposure period required, the type of test specimen, and the criteria of failure are not prescribed by this practice. Such details are provided in appropriate material and product purchase specifications. 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.5 This standard does not purport to address all of the safety c...

  3. Child/Adolescent's ADHD and Parenting Stress: The Mediating Role of Family Impact and Conduct Problems.

    Science.gov (United States)

    Muñoz-Silva, Alicia; Lago-Urbano, Rocio; Sanchez-Garcia, Manuel; Carmona-Márquez, José

    2017-01-01

    Objective: The demands of parenting are usually associated with some stress, and elevated levels of stress may affect the parent-child relationships and parenting practices. This is especially the case of families where children have special needs conditions or disorders, like Attention Deficit Hyperactivity Disorder (ADHD). Method: This study examined parenting stress among mothers of children and adolescents with ADHD. The sample comprised 126 mothers of girls (36; 29%) and boys (90; 71%) aged 6-17 years old. Results: Mothers reported their own stress levels as well as the children and adolescents' variables (severity of their ADHD symptoms, conduct, and emotional problems) and family-contextual variables (negative impact on family's social life, impact on couple relationship, and perceived social support). Hierarchical multiple regression showed that (a) negative impact on social life and conduct problems were the strongest predictors of mother's stress. Bootstrap mediation analyses revealed that (b) the association between child and adolescent's ADHD and parenting stress was mediated by children's conduct problems and by negative impact on family's social life, and not by children's emotional problems nor by mother's perceived social support. The mediation analysis also suggested (c) a pathway from child/adolescent's ADHD through children's conduct problems and then through their negative impact on family's social life to mother's parenting stress. Conclusion: These results suggest that both child/adolescent's and family factors should be considered in the designing of interventions for reducing parenting stress in families of children and adolescents with ADHD.

  4. Benchmark Testing of the Largest Titanium Aluminide Sheet Subelement Conducted

    Science.gov (United States)

    Bartolotta, Paul A.; Krause, David L.

    2000-01-01

    To evaluate wrought titanium aluminide (gamma TiAl) as a viable candidate material for the High-Speed Civil Transport (HSCT) exhaust nozzle, an international team led by the NASA Glenn Research Center at Lewis Field successfully fabricated and tested the largest gamma TiAl sheet structure ever manufactured. The gamma TiAl sheet structure, a 56-percent subscale divergent flap subelement, was fabricated for benchmark testing in three-point bending. Overall, the subelement was 84-cm (33-in.) long by 13-cm (5-in.) wide by 8-cm (3-in.) deep. Incorporated into the subelement were features that might be used in the fabrication of a full-scale divergent flap. These features include the use of: (1) gamma TiAl shear clips to join together sections of corrugations, (2) multiple gamma TiAl face sheets, (3) double hot-formed gamma TiAl corrugations, and (4) brazed joints. The structural integrity of the gamma TiAl sheet subelement was evaluated by conducting a room-temperature three-point static bend test.

  5. Stress analysis of shear/compression test

    International Nuclear Information System (INIS)

    Nishijima, S.; Okada, T.; Ueno, S.

    1997-01-01

    Stress analysis has been made on the glass fiber reinforced plastics (GFRP) subjected to the combined shear and compression stresses by means of finite element method. The two types of experimental set up were analyzed, that is parallel and series method where the specimen were compressed by tilted jigs which enable to apply the combined stresses, to the specimen. Modified Tsai-Hill criterion was employed to judge the failure under the combined stresses that is the shear strength under the compressive stress. The different failure envelopes were obtained between the two set ups. In the parallel system the shear strength once increased with compressive stress then decreased. On the contrary in the series system the shear strength decreased monotonicly with compressive stress. The difference is caused by the different stress distribution due to the different constraint conditions. The basic parameters which control the failure under the combined stresses will be discussed

  6. Hemodynamic stress testing using pacing tachycardia

    International Nuclear Information System (INIS)

    McKay, R.G.; Grossman, W.

    1986-01-01

    A trial pacing was first introduced in 1967 by Sowton and co-workers as a stress test which could be used in the cardiac catheterization laboratory to evaluate patients with schemic heart disease. Sowton noted that artificially increasing the heart rate by pacing the right atrium could usually induce angina in patients with symptomatic coronary artery disease. Since Sowton's original description, numerous investigators have described characteristic pacing-induced electrocardiographic changes, derangements of myocardial lactate metabolism, hemodynamic abnormalities, regional wall abnormalities, and defects in thallium scintigraphy. Although agreement on the overall usefulness of atrial pacing has not been uniform, it is clear that the technique can safely and reliably induce ischemia in most patients with coronary artery disease and that information obtained during the pacing-induced ischemic state can often be helpful in the diagnosis and treatment of the patient's underlying disease

  7. Postirradiation examination data report for gap conductance test series. Test GC 2-1

    International Nuclear Information System (INIS)

    Murdock, B.A.

    1978-02-01

    The results of the postirradiation examination of four boiling water reactor type, zircaloy-clad, UO 2 -fueled rods tested in the Power Burst Facility are discussed. These rods were employed in Gap Conductance Test GC 2-1 which was performed to obtain experimental data from which test fuel rod gap conductance values could be determined by both the steady state ∫kdT and the power oscillation methods. The postirradiation examination results provided in the document will aid in interpreting the experimental data obtained during Test GC 2-1 and in evaluating the effect of fuel behavior on the fuel rod thermal response and interpreted gap conductances. Fuel rod fill gas composition and pressure are discussed. Measurements of fuel pellet-cladding gap and fuel crack areas are presented. The fuel structure is analyzed. Test rod instrumentation and power profiles are examined to better evaluate the test conditions

  8. A Framework for Macroprudential Bank Solvency Stress Testing; Application to S-25 and Other G-20 Country FSAPs

    OpenAIRE

    Andreas A. Jobst; Li L Ong; Christian Schmieder

    2013-01-01

    The global financial crisis has placed the spotlight squarely on bank stress tests. Stress tests conducted in the lead-up to the crisis, including those by IMF staff, were not always able to identify the right risks and vulnerabilities. Since then, IMF staff has developed more robust stress testing methods and models and adopted a more coherent and consistent approach. This paper articulates the solvency stress testing framework that is being applied in the IMF’s surveillance of member countr...

  9. Testing of a single-polarity piezoresistive three-dimensional stress-sensing chip

    International Nuclear Information System (INIS)

    Gharib, H H; Moussa, W A

    2013-01-01

    A new piezoresistive stress-sensing rosette is developed to extract the components of the three-dimensional (3D) stress tensor using single-polarity (n-type) piezoresistors. This paper presents the testing of a micro-fabricated sensing chip utilizing the developed single-polarity rosette. The testing is conducted using a four-point bending of a chip-on-beam to induce five controlled stress components, which are analyzed both numerically and experimentally. Numerical analysis using finite element analysis is conducted to study the levels of the induced stress components at three rosette-sites and the levels of the stress field non-uniformities, and to simulate the extracted stress components from the sensing rosette. The experimental analysis applied tensile and compressive loads over three rosette-sites at different load increments. The experimentally extracted stress components show good linearity with the applied load and values close to the numerical model. (paper)

  10. Accelerated stress testing of thin film solar cells: Development of test methods and preliminary results

    Science.gov (United States)

    Lathrop, J. W.

    1985-01-01

    If thin film cells are to be considered a viable option for terrestrial power generation their reliability attributes will need to be explored and confidence in their stability obtained through accelerated testing. Development of a thin film accelerated test program will be more difficult than was the case for crystalline cells because of the monolithic construction nature of the cells. Specially constructed test samples will need to be fabricated, requiring committment to the concept of accelerated testing by the manufacturers. A new test schedule appropriate to thin film cells will need to be developed which will be different from that used in connection with crystalline cells. Preliminary work has been started to seek thin film schedule variations to two of the simplest tests: unbiased temperature and unbiased temperature humidity. Still to be examined are tests which involve the passage of current during temperature and/or humidity stress, either by biasing in the forward (or reverse) directions or by the application of light during stress. Investigation of these current (voltage) accelerated tests will involve development of methods of reliably contacting the thin conductive films during stress.

  11. Female False Positive Exercise Stress ECG Testing - Fact Verses Fiction.

    Science.gov (United States)

    Fitzgerald, Benjamin T; Scalia, William M; Scalia, Gregory M

    2018-03-07

    Exercise stress testing is a well validated cardiovascular investigation. Accuracy for treadmill stress electrocardiograph (ECG) testing has been documented at 60%. False positive stress ECGs (exercise ECG changes with non-obstructive disease on anatomical testing) are common, especially in women, limiting the effectiveness of the test. This study investigates the incidence and predictors of false positive stress ECG findings, referenced against stress echocardiography (SE) as a standard. Stress echocardiography was performed using the Bruce treadmill protocol. False positive stress ECG tests were defined as greater than 1mm of ST depression on ECG during exertion, without pain, with a normal SE. Potential causes for false positive tests were recorded before the test. Three thousand consecutive negative stress echocardiograms (1036 females, 34.5%) were analysed (age 59+/-14 years. False positive (F+) stress ECGs were documented in 565/3000 tests (18.8%). F+ stress ECGs were equally prevalent in females (194/1036, 18.7%) and males (371/1964, 18.9%, p=0.85 for the difference). Potential causes (hypertension, left ventricular hypertrophy, known coronary disease, arrhythmia, diabetes mellitus, valvular heart disease) were recorded in 36/194 (18.6%) of the female F+ ECG tests and 249/371 (68.2%) of the male F+ ECG tests (preinforce the value of stress imaging, particularly in women. Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.

  12. Separate effects tests to determine the effective thermal conductivity in the PBMR HTTU test facility

    Energy Technology Data Exchange (ETDEWEB)

    Rousseau, P.G., E-mail: pgr@mtechindustrial.com [School of Mechanical and Nuclear Engineering, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Toit, C.G. du; Antwerpen, W. van [School of Mechanical and Nuclear Engineering, North-West University, Private Bag X6001, Potchefstroom 2520 (South Africa); Antwerpen, H.J. van [M-Tech Industrial (Pty) Ltd., PO Box 19855, Noordbrug 2522 (South Africa)

    2014-05-01

    Thermal-fluid simulations are used extensively to predict the maximum fuel temperatures, flows, pressure drops and thermal capacitance of pebble bed gas cooled reactors in support of the reactor safety case. The PBMR company developed the HTTU non-nuclear test facility in cooperation with M-Tech Industrial (Pty) Ltd. and the North-West University in South Africa to conduct comprehensive separate effects tests as well as integrated effects tests to study the different thermal-fluid phenomena. This paper describes the separate effects tests that were conducted to determine the effective thermal conductivity through the pebble bed under near-vacuum conditions and temperatures up to 1200 °C. It also presents the measured temperature distributions and the methodology applied in the data analysis to derive the resultant values of effective thermal conductivity and its associated uncertainty.

  13. Separate effects tests to determine the effective thermal conductivity in the PBMR HTTU test facility

    International Nuclear Information System (INIS)

    Rousseau, P.G.; Toit, C.G. du; Antwerpen, W. van; Antwerpen, H.J. van

    2014-01-01

    Thermal-fluid simulations are used extensively to predict the maximum fuel temperatures, flows, pressure drops and thermal capacitance of pebble bed gas cooled reactors in support of the reactor safety case. The PBMR company developed the HTTU non-nuclear test facility in cooperation with M-Tech Industrial (Pty) Ltd. and the North-West University in South Africa to conduct comprehensive separate effects tests as well as integrated effects tests to study the different thermal-fluid phenomena. This paper describes the separate effects tests that were conducted to determine the effective thermal conductivity through the pebble bed under near-vacuum conditions and temperatures up to 1200 °C. It also presents the measured temperature distributions and the methodology applied in the data analysis to derive the resultant values of effective thermal conductivity and its associated uncertainty

  14. A Simple Stress Test on Indonesian Islamic Banking Industry

    Directory of Open Access Journals (Sweden)

    Dece Kurniadi

    2018-02-01

    Full Text Available The purpose of this study is to conduct a stress test on Indonesian Islamic Banking industry in order toassess the capability of the industry to absorb the extreme risks that may happen in the future. Using data from April 2008 to September 2014, the study employs balance sheet approach in performing the stress test on profitability and capital position and the value at risk technique for liquidity stress test. The results of this study show that in term of profitability, Islamic banks in Indonesia are immune from losses if the default rate (Non-Performing Loan is less than 8.5 %. If the industry can improve the profit margin, the resistance will be higher.In term of capital position, by assuming loss given default (LGD is constant at 40%, the industry will not go bankrupt if probability of default (PD is less than 9%. If the PD is more than 9%, total expected loss is more than available capital. Using the value at risk (VaR at 99% confidence, the study finds that possible deposit flight will not exceed IDR 26 trillion and the liquid asset available is IDR 28 trillion. The study concludes that there is no liquidity threat for Islamic banks in Indonesia. The findingsalso uncover the risky condition that even though the capital adequacy ratio (CAR is on average 14%, real capital measured by Equity to total asset (ETA is only 5.4%

  15. Effect of heat stress on cardiac output and systemic vascular conductance during simulated hemorrhage to presyncope in young men

    DEFF Research Database (Denmark)

    Ganio, Matthew S; Overgaard, Morten; Seifert, Thomas

    2012-01-01

    During moderate actual or simulated hemorrhage, as cardiac output decreases, reductions in systemic vascular conductance (SVC) maintain mean arterial pressure (MAP). Heat stress, however, compromises the control of MAP during simulated hemorrhage, and it remains unknown whether this response is due...... to a persistently high SVC and/or a low cardiac output. This study tested the hypothesis that an inadequate decrease in SVC is the primary contributing mechanism by which heat stress compromises blood pressure control during simulated hemorrhage. Simulated hemorrhage was imposed via lower body negative pressure...... normothermic is no longer adequate during a heat-stressed-simulated hemorrhage. The absence of a decrease in SVC at a time of profound reductions in MAP suggests that inadequate control of vascular conductance is a primary mechanism compromising blood pressure control during these conditions....

  16. High temperature aqueous stress corrosion testing device

    International Nuclear Information System (INIS)

    Bornstein, A.N.; Indig, M.E.

    1975-01-01

    A description is given of a device for stressing tensile samples contained within a high temperature, high pressure aqueous environment, thereby permitting determination of stress corrosion susceptibility of materials in a simple way. The stressing device couples an external piston to an internal tensile sample via a pull rod, with stresses being applied to the sample by pressurizing the piston. The device contains a fitting/seal arrangement including Teflon and weld seals which allow sealing of the internal system pressure and the external piston pressure. The fitting/seal arrangement allows free movement of the pull rod and the piston

  17. Ultrasonic test of highly stressed gear shafts

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, T. [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W. [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J. [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H. [Siemens Power Generation (Germany)

    1998-12-31

    In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

  18. Ultrasonic test of highly stressed gear shafts

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, T [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H [Siemens Power Generation (Germany)

    1999-12-31

    In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

  19. Test plan for in situ stress measurement system development

    International Nuclear Information System (INIS)

    Kim, K.

    1981-09-01

    The tests are to be performed to provide information regarding the state of stress of the basalt rock beneath the Hanford Site. This test series is designed to obtain information necessary to determine if hydrofracturing stress measurement is feasible in a fractured basalt medium. During the course of these field tests, it will be attempted to adapt the conventional hydrofracturing test method and analysis techniques to the basalt medium. If the test is shown to be feasible, more holes will be identified for testing. A comprehensive in situ stress determination program will be initiated. 2 figs

  20. Defect detection in conducting materials using eddy current testing techniques

    Directory of Open Access Journals (Sweden)

    Brauer Hartmut

    2014-01-01

    Full Text Available Lorentz force eddy current testing (LET is a novel nondestructive testing technique which can be applied preferably to the identification of internal defects in nonmagnetic moving conductors. The LET is compared (similar testing conditions with the classical eddy current testing (ECT. Numerical FEM simulations have been performed to analyze the measurements as well as the identification of internal defects in nonmagnetic conductors. The results are compared with measurements to test the feasibility of defect identification. Finally, the use of LET measurements to estimate of the electrical conductors under test are described as well.

  1. Critical wall shear stress for the EHEDG test method

    DEFF Research Database (Denmark)

    Jensen, Bo Boye Busk; Friis, Alan

    2004-01-01

    In order to simulate the results of practical cleaning tests on closed processing equipment, based on wall shear stress predicted by computational fluid dynamics, a critical wall shear stress is required for that particular cleaning method. This work presents investigations that provide a critical...... wall shear stress of 3 Pa for the standardised EHEDG cleaning test method. The cleaning tests were performed on a test disc placed in a radial flowcell assay. Turbulent flow conditions were generated and the corresponding wall shear stresses were predicted from CFD simulations. Combining wall shear...... stress predictions from a simulation using the low Re k-epsilon and one using the two-layer model of Norris and Reynolds were found to produce reliable predictions compared to empirical solutions for the ideal flow case. The comparison of wall shear stress curves predicted for the real RFC...

  2. 30 CFR 250.1151 - How often must I conduct well production tests?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How often must I conduct well production tests... Requirements Well Tests and Surveys § 250.1151 How often must I conduct well production tests? (a) You must conduct well production tests as shown in the following table: You must conduct: And you must submit to...

  3. Round robin testing of thermal conductivity reference materials

    International Nuclear Information System (INIS)

    Hulstrom, L.C.; Tye, R.P.; Smith, S.E.

    1985-07-01

    The Basalt Waste Isolation Project (BWIP), operated by Rockwell Hanford Operations, has a need to determine the thermal properties of basalt in the region being considered for a nuclear waste repository in basalt. Experimental data on thermal conductivity and its variation with temperature are information required for the characterization of basalt. To establish thermal conductivity values for the reference materials, an interlaboratory measurements program was undertaken. The program was planned to meet the objectives of performing an experimental characterization of the new stock and providing a detailed analysis of the results such that reference values of thermal conductivity could be determined. This program of measurements of the thermal conductivity of Pyrex 7740 and Pyroceram 9606 has produced recommended values that are within +- 1% of those accepted previously. These measurements together with those of density indicate that the present lots of material are similar to those previously available. Pyrex 7740 and Pyroceram 9606 can continue to be used with confidence as thermal conductivity reference materials for studies on rocks and minerals and other materials of similar thermal conductivity. The uncertainty range for Pyrex 7740 and Pyroceram 9606 up to 300 0 C is +- 10.3% and +- 5.6%, respectively. This range is similar to that indicated for the previously recommended values proposed some 18 years ago. It would appear that the overall state of the art in thermal conductivity measurements for materials in this range has changed little in the intervening years. The above uncertainties, which would have been greater had not three data sets been eliminated, are greater than those which are normally claimed for each individual method. Analyses of these differences through refinements in techniques and additional measurements to higher temperatures are required. 13 refs., 7 figs., 4 tabs

  4. Stress Optical Coefficient, Test Methodology, and Glass Standard Evaluation

    Science.gov (United States)

    2016-05-01

    ARL-TN-0756 ● MAY 2016 US Army Research Laboratory Stress Optical Coefficient, Test Methodology , and Glass Standard Evaluation...Stress Optical Coefficient, Test Methodology , and Glass Standard Evaluation by Clayton M Weiss Oak Ridge Institute for Science and Education...ORISE), Belcamp, MD Parimal J Patel Weapons and Materials Research Directorate, ARL Approved for public release; distribution is

  5. Thermal stresses in the space shuttle orbiter: Analysis versus test

    International Nuclear Information System (INIS)

    Grooms, H.R.; Gibson, W.F. Jr.; Benson, P.L.

    1984-01-01

    Significant temperature differences occur between the internal structure and the outer skin of the Space Shuttle Orbiter as it returns from space. These temperature differences cause important thermal stresses. A finite element model containing thousands of degrees of freedom is used to predict these stresses. A ground test was performed to verify the prediction method. The analysis and test results compare favorably. (orig.)

  6. Relationships between adolescents' test anxiety, stress and sleep

    NARCIS (Netherlands)

    Dewald, J.F.; Meijer, A.M.; Oort, F.J.; Bögels, S.M.

    2012-01-01

    Objective. This study aims to investigate the relationship between adolescents' test anxiety, stress and different aspects of sleep. Method. 175 adolescents (70.8% girls, mean age 15.14 years) participated in the study. Test anxiety, stress and chronic sleep reduction were assessed at baseline using

  7. Compressive stress-electrical conductivity characteristics of multiwall carbon nanotube networks

    Czech Academy of Sciences Publication Activity Database

    Slobodian, P.; Říha, Pavel; Lengálová, A.; Sáha, P.

    2011-01-01

    Roč. 46, č. 9 (2011), s. 3186-3190 ISSN 0022-2461 R&D Projects: GA AV ČR IAA200600803 Institutional research plan: CEZ:AV0Z20600510 Keywords : carbon nanotube network * compression * electrical conductivity * stress sensor Subject RIV: BK - Fluid Dynamics Impact factor: 2.015, year: 2011

  8. 30 CFR 27.9 - Date for conducting tests.

    Science.gov (United States)

    2010-07-01

    ... Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND... completing such other test work as may be in progress. [31 FR 10607, Aug. 9, 1966, as amended at 70 FR 46343.... The date of receipt of an application will determine the order of precedence for investigation and...

  9. 30 CFR 250.1152 - How do I conduct well tests?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How do I conduct well tests? 250.1152 Section... Tests and Surveys § 250.1152 How do I conduct well tests? (a) When you conduct well tests you must: (1... during completion, recompletion, reworking, or treatment operations before you start a well test; (2...

  10. An introduction to the 'Psycho-Physiological-Stress-Test' (PPST-A standardized instrument for evaluating stress reactions.

    Directory of Open Access Journals (Sweden)

    Elisabeth Neureiter

    Full Text Available Using a standardized instrument to evaluate patients' stress reactions has become more important in daily clinical routines. Different signs or symptoms of stress are often unilaterally explored: the physiological, psychological or social aspects of stress disorders are each viewed on a single dimension. However, all dimensions afflict patients who have persistent health problems due to chronic stress. Therefore, it is important to use a multidimensional approach to acquire data. The 'Psycho-Physiological-Stress-Test' (PPST was established to achieve a comprehensive understanding of stress and was further developed at the Charité-Universitätsmedizin Berlin in collaboration with the Psychological Department of Freie Universität Berlin. The PPST includes a series of varying stress phases, embedded in two periods of rest. Physiological and psychological parameters are simultaneously measured throughout the test session. Specifically, the PPST activates the sympathetic stress axis, which is measured by heart rate, blood pressure, respiration depth and rate, electro dermal activation and muscle tension (frontalis, masseter, trapezius. Psychological data are simultaneously collected, and include performance, motivation, emotion and behavior. After conducting this diagnostic test, it is possible to identify individual stress patterns that can be discussed with the individual patient to develop and recommend (outpatient treatment strategies. This paper introduces the PPST as a standardized way to evaluate stress reactions by presenting the results from a sample of psychosomatic inpatients (n = 139 who were treated in Charité-Universitätsmedizin Berlin, Germany. We observed that the varying testing conditions provoked adjusted changes in the different physiological parameters and psychological levels.

  11. Current trends and future development in pharmacologic stress testing

    International Nuclear Information System (INIS)

    Bae, Jin Ho; Lee, Jae Tae

    2005-01-01

    Pharmacologic stress testing for myocardial perfusion imaging is a widely used noninvasive method for the evaluation of known or suspected coronary artery disease. The use of exercise for cardiac stress has been practiced for over 60 years and clinicians are familiar with its using. However, there are inevitable situations in which exercise stress is inappropriate. A large number of patients with cardiac problems are unable to exercise to their full potential due to comorbidity such as osteoarthritis, vascular disease and pulmonary disease and a standard exercise stress test for myocardial perfusion imaging is suboptimal means for assessment of coronary artery disease. This problem has led to the development of the pharmacologic stress test and to a great increase in its popularity. All of the currently used pharmacologic agents have well-documented diagnostic value. This review deals the physiological actions, clinical protocols, safety, nuclear imaging applications of currently available stress agents and future development of new vasodilating agents

  12. Stress test of the nuclear power plants performed in Taiwan

    Energy Technology Data Exchange (ETDEWEB)

    Wu, C.H.; Teng, W.C.; Chang, S.; Chen, Y.B. [Atomic Energy Council, Taipei, Taiwan (China)

    2014-07-01

    In the wake of Japan's Fukushima Daiichi Nuclear Power Plants event, the Atomic Energy Council (AEC) has asked Taiwan's Nuclear Power Plant operator (TPC) to re-examine and re-evaluate the vulnerabilities of its nuclear units, and furthermore, take possible countermeasures against extreme natural disasters, including earthquake, tsunami and rock-and-mud slide. The evaluation process should be based on both within and beyond Design Basis Accidents, by reference to the actions recommended by the world nuclear authorities and groups, namely, IAEA, USNRC, NEI, ENSREG and WANO. Taiwan is a very densely populated region of the world. Furthermore, like Japan, due to its geophysical position, Taiwan is prone to large scale earthquakes, and although historically rare, Taiwan also faces the potential risk of tsunamis. AEC also asked TPC to perform the stress test following the specification given by WENRA (later ENSREG) and conducted in all the EU's nuclear reactors. After completion of the stress test for all the nuclear power plants, AEC was trying to have the reports peer reviewed by international organizations, as EU did. The OECD/NEA accepted AEC's request and formed a review team specific to the review of Taiwan's National Report for the Stress Test. There were 18 follow-up items after the NEA's review. Based on these items, AEC developed five orders to require TPC further enhancing their capabilities to cope with extreme natural hazards. The ENSREG also formed a nine-expert review team for Taiwan's Stress Test in response to AEC's request almost at the same time as the OECD/NEA. The ENSREG review team began their works in June 2013 by desktop review, and ended in early October 2013 by country visit to Taiwan. While the assessment of post-Fukushima evaluation reveals neither immediate nuclear safety concerns nor threats to the public health and safety, AEC requested that TPC focus on strengthening its re-evaluation on design

  13. Stress test of the nuclear power plants performed in Taiwan

    International Nuclear Information System (INIS)

    Wu, C.H.; Teng, W.C.; Chang, S.; Chen, Y.B.

    2014-01-01

    In the wake of Japan's Fukushima Daiichi Nuclear Power Plants event, the Atomic Energy Council (AEC) has asked Taiwan's Nuclear Power Plant operator (TPC) to re-examine and re-evaluate the vulnerabilities of its nuclear units, and furthermore, take possible countermeasures against extreme natural disasters, including earthquake, tsunami and rock-and-mud slide. The evaluation process should be based on both within and beyond Design Basis Accidents, by reference to the actions recommended by the world nuclear authorities and groups, namely, IAEA, USNRC, NEI, ENSREG and WANO. Taiwan is a very densely populated region of the world. Furthermore, like Japan, due to its geophysical position, Taiwan is prone to large scale earthquakes, and although historically rare, Taiwan also faces the potential risk of tsunamis. AEC also asked TPC to perform the stress test following the specification given by WENRA (later ENSREG) and conducted in all the EU's nuclear reactors. After completion of the stress test for all the nuclear power plants, AEC was trying to have the reports peer reviewed by international organizations, as EU did. The OECD/NEA accepted AEC's request and formed a review team specific to the review of Taiwan's National Report for the Stress Test. There were 18 follow-up items after the NEA's review. Based on these items, AEC developed five orders to require TPC further enhancing their capabilities to cope with extreme natural hazards. The ENSREG also formed a nine-expert review team for Taiwan's Stress Test in response to AEC's request almost at the same time as the OECD/NEA. The ENSREG review team began their works in June 2013 by desktop review, and ended in early October 2013 by country visit to Taiwan. While the assessment of post-Fukushima evaluation reveals neither immediate nuclear safety concerns nor threats to the public health and safety, AEC requested that TPC focus on strengthening its re-evaluation on design

  14. Super Conducting and Conventional Magnets Test & Mapping Facilities

    Data.gov (United States)

    Federal Laboratory Consortium — Vertical Magnet Test Facility: Accommodate a device up to 3.85 m long, 0.61 m diameter, and 14,400 lbs. Configured for 5 psig sub-cooled liquid helium bath cooling...

  15. Exertional headache and coronary ischemia despite normal electrocardiographic stress testing.

    Science.gov (United States)

    Cutrer, F Michael; Huerter, Karina

    2006-01-01

    Exertional headaches may under certain conditions reflect coronary ischemia. We report the case of a patient seen in a neurology referral practice whose exertional headaches, even in the face of two normal electrocardiographic stress tests and in the absence of underlying chest pain were the sole symptoms of coronary ischemia as detected by Tc-99m Sestamibi testing SPECT stress testing. Stent placement resulted in complete resolution of headaches. Exertional headache in the absence of chest pain may reflect underlying symptomatic coronary artery disease (CAD) even when conventional electrocardiographic stress testing does not indicate ischemia.

  16. Re-analysis of hydraulic tests conducted for well 4A

    International Nuclear Information System (INIS)

    Swanson, L.C.

    1994-01-01

    During 1992, a series of hydrologic characterization tests were conducted at the well 4A -- 4T test facility complex. Details concerning these tests are described in Swanson (1992). Two of the tests, a constant-rate discharge test conducted on March 30, 1992 and a slug interference test performed on April 15, 1992, are the focus of this report

  17. Conducting field studies for testing pesticide leaching models

    Science.gov (United States)

    Smith, Charles N.; Parrish, Rudolph S.; Brown, David S.

    1990-01-01

    A variety of predictive models are being applied to evaluate the transport and transformation of pesticides in the environment. These include well known models such as the Pesticide Root Zone Model (PRZM), the Risk of Unsaturated-Saturated Transport and Transformation Interactions for Chemical Concentrations Model (RUSTIC) and the Groundwater Loading Effects of Agricultural Management Systems Model (GLEAMS). The potentially large impacts of using these models as tools for developing pesticide management strategies and regulatory decisions necessitates development of sound model validation protocols. This paper offers guidance on many of the theoretical and practical problems encountered in the design and implementation of field-scale model validation studies. Recommendations are provided for site selection and characterization, test compound selection, data needs, measurement techniques, statistical design considerations and sampling techniques. A strategy is provided for quantitatively testing models using field measurements.

  18. Sex and stress: Men and women show different cortisol responses to psychological stress induced by the Trier social stress test and the Iowa singing social stress test.

    Science.gov (United States)

    Reschke-Hernández, Alaine E; Okerstrom, Katrina L; Bowles Edwards, Angela; Tranel, Daniel

    2017-01-02

    Acute psychological stress affects each of us in our daily lives and is increasingly a topic of discussion for its role in mental illness, aging, cognition, and overall health. A better understanding of how such stress affects the body and mind could contribute to the development of more effective clinical interventions and prevention practices. Over the past 3 decades, the Trier Social Stress Test (TSST) has been widely used to induce acute stress in a laboratory setting based on the principles of social evaluative threat, namely, a judged speech-making task. A comparable alternative task may expand options for examining acute stress in a controlled laboratory setting. This study uses a within-subjects design to examine healthy adult participants' (n = 20 men, n = 20 women) subjective stress and salivary cortisol responses to the standard TSST (involving public speaking and math) and the newly created Iowa Singing Social Stress Test (I-SSST). The I-SSST is similar to the TSST but with a new twist: public singing. Results indicated that men and women reported similarly high levels of subjective stress in response to both tasks. However, men and women demonstrated different cortisol responses; men showed a robust response to both tasks, and women displayed a lesser response. These findings are in line with previous literature and further underscore the importance of examining possible sex differences throughout various phases of research, including design, analysis, and interpretation of results. Furthermore, this nascent examination of the I-SSST suggests a possible alternative for inducing stress in the laboratory. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Stress Tests for Chest Pain: When You Need an Imaging Test -- and When You Don't

    Science.gov (United States)

    ... Resources Adult , Geriatric Stress Tests for Chest Pain Stress Tests for Chest Pain When you need an ... pain isn’t from heart disease. A cardiac stress test makes the heart work hard so your ...

  20. Integrated Stirling Convertor and Hall Thruster Test Conducted

    Science.gov (United States)

    Mason, Lee S.

    2002-01-01

    An important aspect of implementing Stirling Radioisotope Generators on future NASA missions is the integration of the generator and controller with potential spacecraft loads. Some recent studies have indicated that the combination of Stirling Radioisotope Generators and electric propulsion devices offer significant trip time and payload fraction benefits for deep space missions. A test was devised to begin to understand the interactions between Stirling generators and electric thrusters. An electrically heated RG- 350 (350-W output) Stirling convertor, designed and built by Stirling Technology Company of Kennewick, Washington, under a NASA Small Business Innovation Research agreement, was coupled to a 300-W SPT-50 Hall-effect thruster built for NASA by the Moscow Aviation Institute (RIAME). The RG-350 and the SPT-50 shown, were installed in adjacent vacuum chamber ports at NASA Glenn Research Center's Electric Propulsion Laboratory, Vacuum Facility 8. The Stirling electrical controller interfaced directly with the Hall thruster power-processing unit, both of which were located outside of the vacuum chamber. The power-processing unit accepted the 48 Vdc output from the Stirling controller and distributed the power to all the loads of the SPT-50, including the magnets, keeper, heater, and discharge. On February 28, 2001, the Glenn test team successfully operated the Hall-effect thruster with the Stirling convertor. This is the world's first known test of a dynamic power source with electric propulsion. The RG-350 successfully managed the transition from the purely resistive load bank within the Stirling controller to the highly capacitive power-processing unit load. At the time of the demonstration, the Stirling convertor was operating at a hot temperature of 530 C and a cold temperature of -6 C. The linear alternator was producing approximately 250 W at 109 Vac, while the power-processing unit was drawing 175 W at 48 Vdc. The majority of power was delivered to the

  1. California's Drought - Stress test for the future

    Science.gov (United States)

    Lund, J. R.

    2014-12-01

    The current California drought is in its third dry years, with this year being the third driest years in a 106-year record. This drought occurs at a time when urban, agricultural, and environmental water demands have never been greater. This drought has revealed the importance of more quantitative evaluation and methods for water assessment and management. All areas of water and environmental management are likely to become increasingly stressed, and have essentially drought-like conditions, in the future, as California's urban, agricultural, and environmental demands continue to expand and as the climate changes. In the historical past, droughts have pre-viewed stresses developing in the future and helped focus policy-makers, the public, and stakeholders on preparing for these developing future conditions. Multi-decade water management strategies are often galvinized by drought. Irrigation was galvanized by California droughts in the 1800s, reservoir systems by the 1928-32 drought, urban water conservation by the 1976-77 drought, and water markets by the 1988-92 drought. With each drought, demands for tighter accounting, rights, and management have increased. This talk reviews the prospects and challenges for increased development and use of water data and systems analysis in the service of human and environmental water demands in California's highly decentralized water management system, and the prospects if these challenges are not more successfully addressed.

  2. Moral Stress and Job Burnout Among Frontline Staff Conducting Clinical Research on Affective and Anxiety Disorders.

    Science.gov (United States)

    Fried, Adam L; Fisher, Celia B

    2016-06-01

    There has been increased attention on job-related stress and burnout experienced by clinicians working with vulnerable and at-risk populations, including effects on personal mental health, therapeutic decision-making, and job effectiveness. Little is known, however, about the job-related stressors and symptoms of burnout experienced by clinical research staff working with similar populations, especially in terms of moral stress they may experience when adherence to scientific procedures appears to conflict with their personal commitment to address the clinical needs of their research participants or role as health care provider. In this national study, 125 frontline research workers conducting clinical research studies with individuals diagnosed with affective and anxiety disorders completed an online survey including measures assessing research work related moral stress, job burnout, organizational ethics climate and organizational research support. Results indicated that younger research workers, those whose research work was part of a graduate assistantship and perceptions of higher participant research risk were associated with higher levels of moral stress and job burnout. Supportive organizational climates were associated with lower levels of moral stress and job burnout. Recommendations for clinical research workers, supervisors and clinical training directors are discussed.

  3. 10 CFR 26.101 - Conducting a confirmatory test for alcohol.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Conducting a confirmatory test for alcohol. 26.101 Section... Testing § 26.101 Conducting a confirmatory test for alcohol. (a) The confirmatory test must begin as soon... that meets the requirements of § 26.91(b) and (c) was used for the initial alcohol test, the same EBT...

  4. Stress Testing of Transactional Database Systems

    OpenAIRE

    Meira , Jorge Augusto; Cunha De Almeida , Eduardo; Sunyé , Gerson; Le Traon , Yves; Valduriez , Patrick

    2013-01-01

    International audience; Transactional database management systems (DBMS) have been successful at supporting traditional transaction processing workloads. However, web-based applications that tend to generate huge numbers of concurrent business operations are pushing DBMS performance over their limits, thus threatening overall system availability. Then, a crucial question is how to test DBMS performance under heavy workload conditions. Answering this question requires a testing methodology to ...

  5. [Stress-corrosion test of TIG welded CP-Ti].

    Science.gov (United States)

    Li, H; Wang, Y; Zhou, Z; Meng, X; Liang, Q; Zhang, X; Zhao, Y

    2000-12-01

    In this study TIG (Tungsten Inert Gas) welded CP-Ti were subjected to stress-corrosion test under 261 MPa in artificial saliva of 37 degrees C for 3 months. No significant difference was noted on mechanical test (P > 0.05). No color-changed and no micro-crack on the sample's surface yet. These results indicate that TIG welded CP-Ti offers excellent resistance to stress corrosion.

  6. Estimating Hydraulic Conductivities in a Fractured Shale Formation from Pressure Pulse Testing and 3d Modeling

    Science.gov (United States)

    Courbet, C.; DICK, P.; Lefevre, M.; Wittebroodt, C.; Matray, J.; Barnichon, J.

    2013-12-01

    logging, porosity varies by a factor of 2.5 whilst hydraulic conductivity varies by 2 to 3 orders of magnitude. In addition, a 3D numerical reconstruction of the internal structure of the fault zone inferred from borehole imagery has been built to estimate the permeability tensor variations. First results indicate that hydraulic conductivity values calculated for this structure are 2 to 3 orders of magnitude above those measured in situ. Such high values are due to the imaging method that only takes in to account open fractures of simple geometry (sine waves). Even though improvements are needed to handle more complex geometry, outcomes are promising as the fault damaged zone clearly appears as the highest permeability zone, where stress analysis show that the actual stress state may favor tensile reopening of fractures. Using shale samples cored from the different internal structures of the fault zone, we aim now to characterize the advection and diffusion using laboratory petrophysical tests combined with radial and through-diffusion experiments.

  7. Evaluation of micro fatigue crack growth under equi-biaxial stress by membranous pressure fatigue test

    International Nuclear Information System (INIS)

    Iida, Satoshi; Abe, Shigeki; Nakamura, Takao; Kamaya, Masayuki

    2014-01-01

    For preventing nuclear power plant (NPP) accidents, NPPs are required to ensure system safety in long term safe operation under aging degradation. Now, fatigue accumulation is one of major ageing phenomena and are evaluated to ensure safety by design fatigue curve that are based on the results of uniaxial fatigue tests. On the other hand, thermal stress that occurs in piping of actual components is not uniaxial but equi-biaxial. For accurate evaluation, it is required to conform real circumstance. In this study, membranous pressure fatigue test was conducted to simulated equi-biaxial stress. Crack initiation and crack growth were examined by replica investigation. Calculation result of equivalent stress intensity factor shows crack growth under equi-biaxial stress is faster than under uniaxial stress. It is concluded that equi-biaxial fatigue behavior should be considered in the evaluation of fatigue crack initiation and crack growth. (author)

  8. 30 CFR 250.460 - What are the requirements for conducting a well test?

    Science.gov (United States)

    2010-07-01

    ... Other Drilling Requirements § 250.460 What are the requirements for conducting a well test? (a) If you intend to conduct a well test, you must include your projected plans for the test with your APD (form MMS...) You must give the District Manager at least 24-hours notice before starting a well test. [68 FR 8423...

  9. Performa Inhibitory Control dengan Induksi Sing-a-Song Stress Test pada Dewasa Awal

    Directory of Open Access Journals (Sweden)

    Akhmad Kurniawan

    2018-04-01

    Full Text Available Inhibitory control is able to control attention by inhibiting internal tendencies and external influences. Inhibitory control is controlled by dorsolateral prefrontal cortex and anterior cingulate cortex, that can be affected by stress variable. Sing-a-Song Stress Test (SSST is a current method to induce stress that has never been practiced in study of inhibitory control. This study aimed to determine the effect of SSST against inhibitory control in early adult. Between subjects design was applied in this study. A number of 35 participants with age range from 17 to 21 years old were randomly assigned into experimental group (n = 17 and control group (n = 18. Inhibitory control was measured using Computerized Stroop Color-Word Test (CSCWT. Positive Affect and Negative Affect Schedule (PANAS was used to conduct a manipulation check. Independent-Samples T Test explained no significant effect of stress on inhibitory control (t = -0,117; p > 0,05.

  10. Dipyridamole cerebral flow stress test evaluating ischemic cerebrovascular diseases

    International Nuclear Information System (INIS)

    Xiu, Y.; Chen, S.; Sun, X.; Liu, S.; Li, W.; Fan, W.; Wang, X.

    2000-01-01

    To detect the clinical value of dipyridamole cerebral blood flow stress test in cerebrovascular diseases (CVD). Nineteen patients (9 male, 10 female, mean age=65) who were diagnosed as CVD were included. One suffered from infarct, two suffered from thrombosis, one feel dizziness. All 4 performed rest and stress test. The other 15 were VBI, 9 of them performed stress test. Rest and stress test were done two-day method using Elscint Apex SP-6 SPECT equipped with low energy all purpose collimator. Rest perfusion imaging was started 30 min after injecting 1.11 GBq 99m Tc-ECD. Dipyridamole stress test was done within one week. 0.56 mg/Kg dipyridamole was injected intravenously during 4 min the same dose of ECD was injected 2 min later. The acquisition started 30 min later with the same parameter. Heart rate, ECG and the patient's complaint were monitored 2 min before and after dipyridamole. After correction for attenuation, transverse, coronal and sagittal slices were reconstructed. Eighteen ROIs were drawn symmetrically on cingulate, frontal, temporal-parietal, temporal, occipital, vision cortex, basal ganglia, superior frontal and parietal on the 3 rd , 6 th , 9 th transverse slices, selecting the contralateral as the reference region. The counts per pixel in each ROI were divided by the counts of the mirror region to obtain the relative uptake ratio. We think it abnormality when the ratio is above 1,1 or below 0.9. The sensitivity for rest and stress rCBF test was compared. rCBF was decreased at 10 of 19 patients (sensitivity 52.6%). 14 had low rCBF after dipyridamole (sensitivity 72.3%), Among the patients who studied stress test, 6 had normal rCBF at rest and low rCBF after stress. The abnormal area was enlarged after dipyridamole for 1 patients, 2 improved and 2 unchanged. 8 of 15 VBI had normal rCBF at rest (sensitivity 53.3%). 9 of 15 VBI performed stress test. rCBF was normal at rest for 5 patients, rCBF was decreased after stress, it was improved for one

  11. Pilot Testing of the NURSE Stress Management Intervention.

    Science.gov (United States)

    Delaney, Colleen; Barrere, Cynthia; Robertson, Sue; Zahourek, Rothlyn; Diaz, Desiree; Lachapelle, Leeanne

    2016-12-01

    Student nurses experience significant stress during their education, which may contribute to illness and alterations in health, poor academic performance, and program attrition. The aim of this pilot study was to evaluate the feasibility and potential efficacy of an innovative stress management program in two baccalaureate nursing programs in Connecticut, named NURSE (Nurture nurse, Use resources, foster Resilience, Stress and Environment management), that assists nursing students to develop stress management plans. An explanatory sequential mixed-methods design was used to evaluate the effects of the intervention with 40 junior nursing students. Results from this study provide evidence that the NURSE intervention is highly feasible, and support further testing to examine the effect of the intervention in improving stress management in nursing students. © The Author(s) 2015.

  12. Noninvasive electrical conductivity measurement by MRI: a test of its validity and the electrical conductivity characteristics of glioma.

    Science.gov (United States)

    Tha, Khin Khin; Katscher, Ulrich; Yamaguchi, Shigeru; Stehning, Christian; Terasaka, Shunsuke; Fujima, Noriyuki; Kudo, Kohsuke; Kazumata, Ken; Yamamoto, Toru; Van Cauteren, Marc; Shirato, Hiroki

    2018-01-01

    This study noninvasively examined the electrical conductivity (σ) characteristics of diffuse gliomas using MRI and tested its validity. MRI including a 3D steady-state free precession (3D SSFP) sequence was performed on 30 glioma patients. The σ maps were reconstructed from the phase images of the 3D SSFP sequence. The σ histogram metrics were extracted and compared among the contrast-enhanced (CET) and noncontrast-enhanced tumour components (NCET) and normal brain parenchyma (NP). Difference in tumour σ histogram metrics among tumour grades and correlation of σ metrics with tumour grades were tested. Validity of σ measurement using this technique was tested by correlating the mean tumour σ values measured using MRI with those measured ex vivo using a dielectric probe. Several σ histogram metrics of CET and NCET of diffuse gliomas were significantly higher than NP (Bonferroni-corrected p ≤ .045). The maximum σ of NCET showed a moderate positive correlation with tumour grade (r = .571, Bonferroni-corrected p = .018). The mean tumour σ measured using MRI showed a moderate positive correlation with the σ measured ex vivo (r = .518, p = .040). Tissue σ can be evaluated using MRI, incorporation of which may better characterise diffuse gliomas. • This study tested the validity of noninvasive electrical conductivity measurements by MRI. • This study also evaluated the electrical conductivity characteristics of diffuse glioma. • Gliomas have higher electrical conductivity values than the normal brain parenchyma. • Noninvasive electrical conductivity measurement can be helpful for better characterisation of glioma.

  13. An improved stress corrosion test medium for aluminum alloys

    Science.gov (United States)

    Humphries, T. S.; Coston, J. E.

    1981-01-01

    A laboratory test method that is only mildly corrosive to aluminum and discriminating for use in classifying the stress corrosion cracking resistance of aluminum alloys is presented along with the method used in evaluating the media selected for testing. The proposed medium is easier to prepare and less expensive than substitute ocean water.

  14. Predictive Accuracy of Exercise Stress Testing the Healthy Adult.

    Science.gov (United States)

    Lamont, Linda S.

    1981-01-01

    Exercise stress testing provides information on the aerobic capacity, heart rate, and blood pressure responses to graded exercises of a healthy adult. The reliability of exercise tests as a diagnostic procedure is discussed in relation to sensitivity and specificity and predictive accuracy. (JN)

  15. Market risk stress testing for internationally active financial institutions

    Directory of Open Access Journals (Sweden)

    Marković Petar

    2011-01-01

    Full Text Available The paper develops a comprehensive framework for market risk stress testing in internationally active financial institutions. We begin by defining the scope and type of the stress test and explaining how to select risk factors and the stress time horizon. We then address challenges related to data gathering, followed by in-depth discussion of techniques for developing realistic shock scenarios. Next the process of shock application to a particular portfolio is described, followed by determination of portfolio profit and loss. We conclude by briefly discussing the issue of assigning probability to stress scenarios. We illustrate the framework by considering the development of a ‘worst case’ scenario using global financial market data from Thomson Reuters Datastream.

  16. Safety of a rapid diagnostic protocol with accelerated stress testing.

    Science.gov (United States)

    Soremekun, Olan A; Hamedani, Azita; Shofer, Frances S; O'Conor, Katie J; Svenson, James; Hollander, Judd E

    2014-02-01

    Most patients at low to intermediate risk for an acute coronary syndrome (ACS) receive a 12- to 24-hour "rule out." Recently, trials have found that a coronary computed tomographic angiography-based strategy is more efficient. If stress testing were performed within the same time frame as coronary computed tomographic angiography, the 2 strategies would be more similar. We tested the hypothesis that stress testing can safely be performed within several hours of presentation. We performed a retrospective cohort study of patients presenting to a university hospital from January 1, 2009, to December 31, 2011, with potential ACS. Patients placed in a clinical pathway that performed stress testing after 2 negative troponin values 2 hours apart were included. We excluded patients with ST-elevation myocardial infarction or with an elevated initial troponin. The main outcome was safety of immediate stress testing defined as the absence of death or acute myocardial infarction (defined as elevated troponin within 24 hours after the test). A total of 856 patients who presented with potential ACS were enrolled in the clinical pathway and included in this study. Patients had a median age of 55.0 (interquartile range, 48-62) years. Chest pain was the chief concern in 86%, and pain was present on arrival in 73% of the patients. There were no complications observed during the stress test. There were 0 deaths (95% confidence interval, 0%-0.46%) and 4 acute myocardial infarctions within 24 hours (0.5%; 95% confidence interval, 0.14%-1.27%). The peak troponins were small (0.06, 0.07, 0.07, and 0.19 ng/mL). Patients who present to the ED with potential ACS can safely undergo a rapid diagnostic protocol with stress testing. © 2013.

  17. Impact of peak electricity demand in distribution grids: a stress test

    NARCIS (Netherlands)

    Hoogsteen, Gerwin; Molderink, Albert; Hurink, Johann L.; Smit, Gerardus Johannes Maria; Schuring, Friso; Kootstra, Ben

    2015-01-01

    The number of (hybrid) electric vehicles is growing, leading to a higher demand for electricity in distribution grids. To investigate the effects of the expected peak demand on distribution grids, a stress test with 15 electric vehicles in a single street is conducted and described in this paper.

  18. Toward a generic approach for : Stress testing of drug substances and drug products

    NARCIS (Netherlands)

    Klick, Silke; Muijselaar, Pim G.; Waterval, Joop; Eichinger, Thomas; Korn, Christian; Gerding, Thijs K.; Debets, Alexander J.; Sänger-Van De Griend, Cari; Van Den Beld, Cas; Somsen, Govert W.; De Jong, Gerhardus J.

    The Impurity Profiling Group has developed a generic approach for conducting stress testing on drug substances and drug products. The proposed strategy is evaluated and verified with historical data and new experiments. Results demonstrate that the proposed approach is reasonable and generates

  19. Facial temperature data Sing-a-Song StressTest

    NARCIS (Netherlands)

    Brouwer, A.M.

    2013-01-01

    We here introduce a new experimental paradigm to induce mental stress in a quick and easy way while adhering to ethical standards and controlling for potential confounds resulting from sensory input, body movements and behavior of people involved in conducting the experiment. In our Sing-a-Song

  20. Test plan for suitability assessment of five overcoring stress measurement techniques

    International Nuclear Information System (INIS)

    Gregory, E.C.; Rundle, T.A.; McCabe, W.M.; Kim, K.

    1982-08-01

    Tests are to be conducted at the Near-Surface Test Facility (NSTF) to assess the suitability of five overcoring techniques for in situ stress determination in a jointed basalt. The overcoring methods to be investigated use the following instrumentation to measure strain relief by overcoring a pilot borehole: USBM borehole deformation gage, CSIRO hollow inclusion stress cell, cast epoxy inclusion, the Lulea triaxial strain cell and the ''doorstopper'' biaxial strain cell. The tests are to provide data regarding the state of stress below the NSTF. This information is to be used in the evaluation of each method of overcoring. During the course of field testing, an attempt is to be made to adapt conventional overcoring techniques and analytical methods to the basalt medium. If overcoring stress determination in basalt is shown suitable, then additional studies will be identified to further adapt a technique for use at depth. In addition to the five overcoring techniques to be tested at the NSTF, stress measurements by Hydrofracturing are to be conducted to provide data for direct comparison with overcoring results. 16 refs., 18 figs

  1. Non-Newtonian stress tensor and thermal conductivity tensor in granular plane shear flow

    Science.gov (United States)

    Alam, Meheboob; Saha, Saikat

    2014-11-01

    The non-Newtonian stress tensor and the heat flux in the plane shear flow of smooth inelastic disks are analysed from the Grad-level moment equations using the anisotropic Gaussian as a reference. Closed-form expressions for shear viscosity, pressure, first normal stress difference (N1) and the dissipation rate are given as functions of (i) the density or the area fraction (ν), (ii) the restitution coefficient (e), (iii) the dimensionless shear rate (R), (iv) the temperature anisotropy [ η, the difference between the principal eigenvalues of the second moment tensor] and (v) the angle (ϕ) between the principal directions of the shear tensor and the second moment tensor. Particle simulation data for a sheared hard-disk system is compared with theoretical results, with good agreement for p, μ and N1 over a large range of density. In contrast, the predictions from a Navier-Stokes order constitutive model are found to deviate significantly from both the simulation and the moment theory even at moderate values of e. We show that the gradient of the deviatoric part of the kinetic stress drives a heat current and the thermal conductivity is characterized by an anisotropic 2nd rank tensor for which explicit expressions are derived.

  2. 49 CFR 232.217 - Train brake tests conducted using yard air.

    Science.gov (United States)

    2010-10-01

    ... reduction of brake pipe air pressure at the same, or slower, rate as an engineer's brake valve. (b) The yard... 49 Transportation 4 2010-10-01 2010-10-01 false Train brake tests conducted using yard air. 232... Train brake tests conducted using yard air. (a) When a train air brake system is tested from a yard air...

  3. Stress Corrosion Cracking of Steel and Aluminum in Sodium Hydroxide: Field Failure and Laboratory Test

    Directory of Open Access Journals (Sweden)

    Y. Prawoto

    2012-01-01

    Full Text Available Through an investigation of the field failure analysis and laboratory experiment, a study on (stress corrosion cracking SCC behavior of steel and aluminum was performed. All samples were extracted from known operating conditions from the field failures. Similar but accelerated laboratory test was subsequently conducted in such a way as to mimic the field failures. The crack depth and behavior of the SCC were then analyzed after the laboratory test and the mechanism of stress corrosion cracking was studied. The results show that for the same given stress relative to ultimate tensile strength, the susceptibility to SCC is greatly influenced by heat treatment. Furthermore, it was also concluded that when expressed relative to the (ultimate tensile strength UTS, aluminum has similar level of SCC susceptibility to that of steel, although with respect to the same absolute value of applied stress, aluminum is more susceptible to SCC in sodium hydroxide environment than steel.

  4. Alternate immersion stress corrosion testing of 5083 aluminum

    International Nuclear Information System (INIS)

    Briggs, J.L.; Dringman, M.R.; Hausburg, D.E.; Jackson, R.J.

    1978-01-01

    The stress corrosion susceptibility of Type 5083 aluminum--magnesium alloy in plate form and press-formed shapes was determined in the short transverse direction. C-ring type specimens were exposed to alternate immersion in a sodium chloride solution. The test equipment and procedure, with several innovative features, are described in detail. Statistical test results are listed for seven thermomechanical conditions. A certain processing scheme was shown to yield a work-strengthened part that is not sensitized with respect to stress corrosion cracking

  5. Stress relaxation in tempered glass caused by heat soak testing

    DEFF Research Database (Denmark)

    Schneider, Jens; Hilcken, Jonas; Aronen, Antti

    2016-01-01

    Heat soak testing of tempered glass is a thermal process required after the tempering process itself to bring glasses of commercial soda-lime-silica-glass to failure that are contaminated with nickel sulphide inclusions, diameter 50 mm to 500 mm typically. Thus, the tests avoid a so-called "spont...... of commercial soda-lime-silica glass, it causes stress relaxation in tempered glass and the fracture pattern of the glass changes accordingly, especially thin glasses are affected. Based on the Tool-Narayanaswamy-Model, this paper comprises the theoretical background of the stress...

  6. Cardiac Stress Test Trends Among US Patients Younger Than 65 Years, 2005-2012.

    Science.gov (United States)

    Kini, Vinay; McCarthy, Fenton H; Dayoub, Elias; Bradley, Steven M; Masoudi, Frederick A; Ho, P Michael; Groeneveld, Peter W

    2016-12-01

    After a period of rapid growth, use of cardiac stress testing has recently decreased among Medicare beneficiaries and in a large integrated health system. However, it is not known whether declines in cardiac stress testing are universal or are confined to certain populations. To determine trends in rates of cardiac stress testing among a large and diverse cohort of commercially insured patients. A serial cross-sectional study with time trends was conducted using administrative claims from all members aged 25 to 64 years belonging to a large, national managed care company from January 1, 2005, to December 31, 2012. Linear trends in rates were determined using negative binomial regression models with procedure count as the dependent variable, calendar quarter as the key independent variable, and the size of the population as a logged offset term. Data analysis was performed from January 1, 2005, to December 31, 2012. Age- and sex-adjusted rates of cardiac stress tests per calendar quarter (reported as number of tests per 100 000 person-years). A total of 2 085 591 cardiac stress tests were performed among 32 921 838 persons (mean [SD] age, 43.2 [10.9] years; 16 625 528 women [50.5%] and 16 296 310 [49.5%] men; 7 604 945 nonwhite [23.1%]). There was a 3.0% increase in rates of cardiac stress testing from 2005 (3486 tests; 95% CI, 3458-3514) to 2012 (3589 tests; 95% CI, 3559-3619; P = .01 for linear trend). Use of nuclear single-photon emission computed tomography decreased by 14.9% from 2005 (1907 tests; 95% CI, 1888-1926) to 2012 (1623 tests; 95% CI, 1603-1643; P = .03). Use of stress echocardiography increased by 27.8% from 2005 (709 tests; 95% CI, 697-721) to 2012 (906 tests; 95% CI, 894 to 920; P < .001). Use of exercise electrocardiography increased by 12.5% from 2005 (861 tests; 95% CI, 847-873) to 2012 (969 tests; 95% CI, 953-985; P < .001). Use of other stress testing modalities increased 65.5% from 2006 (55 tests; 95% CI

  7. Negative Exercise Stress Test: Does it Mean Anything? Case study

    Directory of Open Access Journals (Sweden)

    Hassan A. Mohamed

    2007-01-01

    Full Text Available Despite its low sensitivity and specificity (67% and 72%, respectively, exercise testing has remained one of the most widely used noninvasive tests to determine the prognosis in patients with suspected or established coronary disease.As a screening test for coronary artery disease, the exercise stress test is useful in that it is relatively simple and inexpensive. It has been considered particularly helpful in patients with chest pain syndromes who have moderate probability for coronary artery disease, and in whom the resting electrocardiogram (ECG is normal. The following case presentation and discussion will question the predictive value of a negative stress testing in patients with moderate probability for coronary artery disease.

  8. Implementation of stress assessments by occupational health nurses working in occupational health agencies and their confidence in conducting such assessments.

    Science.gov (United States)

    Ikeda, Chiseko; Saeki, Kazuko; Hirano, Michiyo

    2016-06-21

    Stress assessments are due to be conducted in December 2015. It is expected that there will be an increase in the number of private health agencies that provide stress assessment services and mental health care. This study aimed to clarify the current situation of and the factors related to stress assessments conducted by nurses in occupational health agencies. Nurses working full time were randomly selected from 60 organizations that were members of the National Federation of Industrial Health Organization. Self-administered questionnaires were sent out between November 2013 and January 2014. The questionnaire included the personal attributes of the participants, training programs, job contents, and how practical mental health care, including stress assessment, is. The study was approved by the ethics committees in the respective organizations. Out of the 162 questionnaires that were distributed, 89 (54.9%) were returned and 85 (53.1%) were valid for analysis. Stress assessments were conducted by 38.8% of the participants. With reference to their confidence in conducting stress assessments, "confidence and" 70.6%, respectively. The groups that conducted and did not conduct the stress assessments did not show any differences in the findings or other attributes. Further, the implementation of stress assessment was not associated with occupational health nurse (OHN) training, education, position, age, years of experience, attendance of lectures on mental health, etc. However, the confidence in conducting the assessment was related to age when dealing with cases on confidence stress assessment consultation in follow-up to the implementation of screening, such as stress, persons at high risk, and so on. Approximately 40% of the nurses were already conducting stress assessments, but most of them conducted such assessments about once a year and were not deeply involved in them. Approximately 70% of the nurses were confident in implementing stress assessments. Further

  9. NUMERICAL SIMULATION OF AN AGRICULTURAL SOIL SHEAR STRESS TEST

    Directory of Open Access Journals (Sweden)

    Andrea Formato

    2007-03-01

    Full Text Available In this work a numerical simulation of agricultural soil shear stress tests was performed through soil shear strength data detected by a soil shearometer. We used a soil shearometer available on the market to measure soil shear stress and constructed special equipment that enabled automated detection of soil shear stress. It was connected to an acquisition data system that displayed and recorded soil shear stress during the full field tests. A soil shearometer unit was used to the in situ measurements of soil shear stress in full field conditions for different types of soils located on the right side of the Sele river, at a distance of about 1 km from each other, along the perpendicular to the Sele river in the direction of the sea. Full field tests using the shearometer unit were performed alongside considered soil characteristic parameter data collection. These parameter values derived from hydrostatic compression and triaxial tests performed on considered soil samples and repeated 4 times and we noticed that the difference between the maximum and minimum values detected for every set of performed tests never exceeded 4%. Full field shear tests were simulated by the Abaqus program code considering three different material models of soils normally used in the literature, the Mohr-Coulomb, Drucker-Prager and Cam-Clay models. We then compared all data outcomes obtained by numerical simulations with those from the experimental tests. We also discussed any further simulation data results obtained with different material models and selected the best material model for each considered soil to be used in tyre/soil contact simulation or in soil compaction studies.

  10. Sleep deprived and sweating it out: the effects of total sleep deprivation on skin conductance reactivity to psychosocial stress.

    Science.gov (United States)

    Liu, Jean C J; Verhulst, Silvan; Massar, Stijn A A; Chee, Michael W L

    2015-01-01

    We examined how sleep deprivation alters physiological responses to psychosocial stress by evaluating changes in skin conductance. Between-subjects design with one group allocated to 24 h of total sleep deprivation and the other to rested wakefulness. The study took place in a research laboratory. Participants were 40 healthy young adults recruited from a university. Sleep deprivation and feedback. Electrodermal activity was monitored while participants completed a difficult perceptual task with false feedback. All participants showed increased skin conductance levels following stress. However, compared to well-rested participants, sleep deprived participants showed higher skin conductance reactivity with increasing stress levels. Our results suggest that sleep deprivation augments allostatic responses to increasing psychosocial stress. Consequentially, we propose sleep loss as a risk factor that can influence the pathogenic effects of stress. © 2014 Associated Professional Sleep Societies, LLC.

  11. Full-field fabric stress mapping by micro Raman spectroscopy in a yarn push-out test.

    Science.gov (United States)

    Lei, Z K; Qin, F Y; Fang, Q C; Bai, R X; Qiu, W; Chen, X

    2018-02-01

    The full-field stress distribution of a two-dimensional plain fabric was mapped using micro Raman spectroscopy (MRS) through a novel yarn push-out test, simulating a quasi-static projectile impact on the fabric. The stress-strain relationship for a single yarn was established using a digital image correlation method in a single-yarn tensile test. The relationship between Raman peak shift and aramid Kevlar 49 yarn stress was established using MRS in a single-yarn tensile test. An out-of-plane loading test was conducted on an aramid Kevlar 49 plain fabric, and the yarn stress was measured using MRS. From the full-field fabric stress distribution, it can be observed that there is a cross-shaped distribution of high yarn stress; this result would be helpful in further studies on load transfer on a fabric during a projectile impact.

  12. Panel manipulation in social stress testing:The Bath experimental stress test for children (BEST-C)

    OpenAIRE

    Cheetham, Tara J.; Turner-Cobb, Julie M.

    2016-01-01

    BackgroundWhilst acute stress paradigms in adults make use of adult panel members, similar paradigms modified for child participants have not manipulated the panel. Most work has utilised an audience of adult confederates, regardless of the age of the population being tested. The aim of this study was to trial a social stress test for children that provided a meaningful environment using age-matched child peers as panel actors.MethodsThirty-three participants (7-11 years) underwent the Bath E...

  13. Electrohydrostatic and electrohydrodynamic theories of equilibrium shapes and stability of electrically stressed conducting liquids

    International Nuclear Information System (INIS)

    Chung, M.S.

    1986-01-01

    This work represents an initial attempt at a systematic and rigorous study of the static and dynamic equilibrium shapes and stability of electrically stressed conducting fluids. The ultimate objective of the research is to explain the basic mechanism(s) describing the operation of a field emission liquid metal ion source. The variational procedure is used to obtain a set of equations whose solutions describe the static fluid shape as a function of applied field. Using an iterative procedure to solve Laplace's equation for an arbitrary geometry, a sequence of profiles is calculated that shows the evolution of the deformed fluid surface with applied field. A systematic study of stability is made by applying the Taylor and Zeleny criteria to quasi-statistically stressed fluids. To formulate a realistic and accurate description of the onset of instability, is is necessary to introduce fluid flow, which requires a dynamical analysis. To maintain contact with the LMIS configuration, the approach to instability is studied in axially symmetric fluids using a linearized set of electrohydrodynamic equations. The analysis is applied to different coordinate surfaces, which are used to model fluid shapes, which are observed, or assumed to exist, in an operating LMIS just prior to or at the onset of emission. Results suggest a new interpretation of the onset of instability

  14. Stress test, what is the reality and significance of it?

    International Nuclear Information System (INIS)

    Sawada, Tetsuo

    2012-01-01

    Stress test was introduced in July 2011 by 'political judgment' to demonstrate the ability of nuclear power plants to withstand severe earthquake and tsunami. Stress test consisted of two stages and the first stage using computerized simulation required to obtain 'cliff edge' for earthquake, tsunami, their superposition, loss of all alternating current power and loss of final heat sink, and effectiveness of severe accident management after emergency safety measures. Clearing the first stage of the test was a prerequisite for restarting reactors that had been suspended for regular inspections. NISA had received such test results for 14 nuclear reactors as of January 18, 2012. After passing IAEA's evaluation of stress test review process, NISA's endorsement of test results, NSC's confirmation of NISA's screening results and approval of local government, Prime Minister and relevant ministers concerned would decide whether reactors could be restarted as 'political judgment'. Using ranking list and referring to respective experiences of 14 reactors hit by earthquake and tsunami at the Great East Japan earthquake might better perform comprehensive judgment. (T. Tanaka)

  15. 40 CFR 63.2354 - What performance tests, design evaluations, and performance evaluations must I conduct?

    Science.gov (United States)

    2010-07-01

    ... evaluations, and performance evaluations must I conduct? 63.2354 Section 63.2354 Protection of Environment... tests, design evaluations, and performance evaluations must I conduct? (a)(1) For each performance test... procedures specified in subpart SS of this part. (3) For each performance evaluation of a continuous emission...

  16. 40 CFR 60.3035 - May I conduct performance testing less often?

    Science.gov (United States)

    2010-07-01

    ... deviation from an emission limitation for any pollutant, you must conduct annual performance tests for that... 40 Protection of Environment 6 2010-07-01 2010-07-01 false May I conduct performance testing less... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Emission Guidelines and Compliance...

  17. 40 CFR 60.2934 - May I conduct performance testing less often?

    Science.gov (United States)

    2010-07-01

    ... deviation from an emission limitation for any pollutant, you must conduct annual performance tests for that... 40 Protection of Environment 6 2010-07-01 2010-07-01 false May I conduct performance testing less... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Operator Training and...

  18. Modification of EBR-II plant to conduct loss-of-flow-without-scram tests

    Energy Technology Data Exchange (ETDEWEB)

    Messick, N C; Betten, P R; Booty, W F; Christensen, L J; Fryer, R M; Mohr, D; Planchon, H P; Radtke, W H

    1987-04-01

    This paper describes the details of and the philosophy behind changes made to the EBR-II plant in order to conduct loss-of-flow-without-scram tests. No changes were required to conduct loss-of-heat-sink-without-scram tests.

  19. Modification of EBR-II plant to conduct loss-of-flow-without-scram tests

    International Nuclear Information System (INIS)

    Messick, N.C.; Betten, P.R.; Booty, W.F.; Christensen, L.J.; Fryer, R.M.; Mohr, D.; Planchon, H.P.; Radtke, W.H.

    1987-01-01

    This paper describes the details of and the philosophy behind changes made to the EBR-II plant in order to conduct loss-of-flow-without-scram tests. No changes were required to conduct loss-of-heat-sink-without-scram tests. (orig.)

  20. Application of stress relaxation testing in evaluation of creep strength of a tungsten-alloyed 10% Cr cast steel

    International Nuclear Information System (INIS)

    Raghavender Rao, G.; Gupta, O.P.; Pradhan, B.

    2011-01-01

    Uniaxial isothermal stress relaxation tests (SRT) were performed on a tungsten-alloyed 10% Cr cast steel (G-X12Cr Mo W V Nb N 10 1 1) at temperatures of 580, 600 and 620 o C and initial strain levels of 0.2, 0.5 and 0.8%. Inelastic strain rates for different stresses were estimated from the stress versus time data generated from the tests. Conventional creep tests were also conducted on the same material at 580, 600 and 620 o C and at different stress levels. The strain rate data estimated from SRT were compared with minimum creep rates derived from the creep tests; the strain rates estimated from SRT with 0.8% initial strain level are in better agreement than those estimated from SRT with 0.2 and 0.5% initial strain levels. In order to ascertain the technique, stress relaxation behaviour was estimated from creep test data and compared with the stress relaxation curves obtained from SRT at corresponding temperatures. The stress relaxation curves obtained from SRT with 0.8% initial strain level are in good agreement with the stress relaxation curves estimated from the creep tests. It is concluded that the stress relaxation test with initial strain level of 0.8% could be considered as an appropriate short-term test technique for estimation of creep strength of newly developed materials.

  1. Do post-trauma symptoms mediate the relation between neurobiological stress parameters and conduct problems in girls?

    Science.gov (United States)

    Babel, Kimberly A; Jambroes, Tijs; Oostermeijer, Sanne; van de Ven, Peter M; Popma, Arne; Vermeiren, Robert R J M; Doreleijers, Theo A H; Jansen, Lucres M C

    2016-01-01

    Attenuated activity of stress-regulating systems has consistently been reported in boys with conduct problems. Results in studies of girls are inconsistent, which may result from the high prevalence of comorbid post-trauma symptoms. Therefore, the aim of the present study is to investigate post-trauma symptoms as a potential mediator in the relation between stress-regulation systems functioning and conduct problems in female adolescents. The sample consisted of 78 female adolescents (mean age 15.4; SD 1.1) admitted to a closed treatment institution. The diagnosis of disruptive behaviour disorder (DBD) was assessed by a structured interview-the diagnostic interview schedule for children version IV (DISC-IV). To assess post-trauma symptoms and externalizing behaviour problems, self-report questionnaires, youth self report (YSR) and the trauma symptom checklist for Children (TSCC) were used. The cortisol awakenings response (CAR) measured hypothalamic-pituitary-adrenal (HPA) axis activity, whereas autonomous nervous system (ANS) activity was assessed by heart rate (HR), pre-ejection period (PEP) and respiratory sinus arrhythmia (RSA). Independent t-tests were used to compare girls with and without DBD, while path analyses tested for the mediating role of post- trauma symptoms in the relation between stress regulating systems and externalizing behaviour. Females with DBD (n = 37) reported significantly higher rates of post-trauma symptoms and externalizing behaviour problems than girls without DBD (n = 39). Path analysis found no relation between CAR and externalizing behaviour problems. With regard to ANS activity, positive direct effects on externalizing behaviour problems were present for HR (standardized β = 0.306, p = 0.020) and PEP (standardized β = -0.323, p = 0.031), though not for RSA. Furthermore, no relation-whether direct or indirect-could be determined from post-trauma symptoms. Present findings demonstrate that the neurobiological

  2. Quantification of Applied Stresses of C-Ring Specimens for Stress Corrosion Cracking Tests

    International Nuclear Information System (INIS)

    Kim, Woo Gon; Kim, Sun Jae; Rhee, Chang Kyu; Kuk, Il Hiun; Choi, Jong Ho

    1997-01-01

    For comparing their resistances for stress-corrosion cracking(SCC) in the K600-MA, K690-MA, and K600-TT tubes, C-ring specimens were fabricated with the various thermal-treatments to control the distributions of the precipitates like Cr-carbides. The bending stresses were analyzed to determine the amounts to make the stress quantitatively to all the C-ring samples, and then the stresses were calculated with the relation to the outer diameter(O.D) deflection(δ) of the C-rings. To measure accurately the bending strains of the C-ring specimens, the strain gauges were used and the compression test was also carried out. In the elastic region, the stresses in both the transverse and the circumferential directions were different with the locations of the strain gauges as attached at α= 30 .deg., 45 .deg., and 90 .deg. to the principal stress direction, but those in the longitudinal direction were independent of their attached locations. Calculated stresses from the strains obtained using the strain gauges were well agreed with the theoretical. In the plastic region over δ=1.0mm, the stresses for the TT tubes showed lower values of about 400MPa than those for the MA tubes. However, the stresses among the TT tubes showed almost the similar values in this region. Therefore, the states of the stresses applied to the C-ring specimens would be different with the material conditions, i.e, the chemical compositions, the thermal treatments such as MA and TT

  3. Testing the Predictive Power of Coulomb Stress on Aftershock Sequences

    Science.gov (United States)

    Woessner, J.; Lombardi, A.; Werner, M. J.; Marzocchi, W.

    2009-12-01

    Empirical and statistical models of clustered seismicity are usually strongly stochastic and perceived to be uninformative in their forecasts, since only marginal distributions are used, such as the Omori-Utsu and Gutenberg-Richter laws. In contrast, so-called physics-based aftershock models, based on seismic rate changes calculated from Coulomb stress changes and rate-and-state friction, make more specific predictions: anisotropic stress shadows and multiplicative rate changes. We test the predictive power of models based on Coulomb stress changes against statistical models, including the popular Short Term Earthquake Probabilities and Epidemic-Type Aftershock Sequences models: We score and compare retrospective forecasts on the aftershock sequences of the 1992 Landers, USA, the 1997 Colfiorito, Italy, and the 2008 Selfoss, Iceland, earthquakes. To quantify predictability, we use likelihood-based metrics that test the consistency of the forecasts with the data, including modified and existing tests used in prospective forecast experiments within the Collaboratory for the Study of Earthquake Predictability (CSEP). Our results indicate that a statistical model performs best. Moreover, two Coulomb model classes seem unable to compete: Models based on deterministic Coulomb stress changes calculated from a given fault-slip model, and those based on fixed receiver faults. One model of Coulomb stress changes does perform well and sometimes outperforms the statistical models, but its predictive information is diluted, because of uncertainties included in the fault-slip model. Our results suggest that models based on Coulomb stress changes need to incorporate stochastic features that represent model and data uncertainty.

  4. System for stress corrosion conditions tests on PWR reactors

    International Nuclear Information System (INIS)

    Castro, Andre Cesar de Jesus

    2007-01-01

    The study of environmentally assisted cracking (EAC) involves the consideration and evaluation of the inherent compatibility between a material and the environment under conditions of either applied or residual stress. EAC is a critical problem because equipment, components and structure are subject to the influence of mechanical stress, water environment of different composition, temperature and different material history. Testing for resistance to EAC is one of the most effective ways to determine the interrelationships among this variables on the process of EAC. Up to now, several experimental techniques have been developed worldwide, which address different aspects of environmental caused damage. Constant loading of CT specimens test is a typical example of test, which is used for the estimation of parameters of stress corrosion cracking. To assess the initiation stages and kinetics of crack growth, the testing facility should allow active loading of specimens in the environment that is close to the actual operation conditions of assessed component. This paper presents a testing facility for stress corrosion cracking to be installed at CDTN, which was designed and developed at CDTN. The facility is used to carry out constant load tests under simulated PWR environment, where temperature, water pressure and chemistry are controlled, which are considered the most important factors in SCC. Also, the equipment operational conditions, its applications, and restrictions are presented. The system was developed to operate at temperature until 380 degree C and pressure until 180 bar. It consists in a autoclave stuck at a mechanical system, responsible of producing load , a water treatment station, and a data acquisition system. This testing facility allows the evaluation of cracking progress, especially at PWR reactor. (author) operational conditions. (author)

  5. Color Shift Modeling of Light-Emitting Diode Lamps in Step-Loaded Stress Testing

    NARCIS (Netherlands)

    Cai, Miao; Yang, Daoguo; Huang, J.; Zhang, Maofen; Chen, Xianping; Liang, Caihang; Koh, S.W.; Zhang, G.Q.

    2017-01-01

    The color coordinate shift of light-emitting diode (LED) lamps is investigated by running three stress-loaded testing methods, namely step-up stress accelerated degradation testing, step-down stress accelerated degradation testing, and constant stress accelerated degradation testing. A power

  6. Yield stress determination from miniaturized disk bend test data

    International Nuclear Information System (INIS)

    Sohn, D.S.; Kohse, G.; Harling, O.K.

    1985-04-01

    Methodology for testing 3.0 mm diameter by 0.25 mm thick disks by bending in a punch and die has been described previously. This paper describes the analysis of load/deflection data from such miniaturized disk bend tests (MDBT) using a finite element simulation. Good simulation has been achieved up to a point just beyond the predominantly elastic response, linear initial region. The load at which deviation from linearity begins has been found to correlate with yield stress, and yield stress has been successfully extracted from disk bend tests of a number of known materials. Although finite element codes capable of dealing with large strains and large rotations have been used, simulation of the entire load/deflection curve up to fracture of the specimen has not yet been achieved

  7. 9 CFR 55.8 - Official CWD tests and approval of laboratories to conduct official CWD tests.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Official CWD tests and approval of laboratories to conduct official CWD tests. 55.8 Section 55.8 Animals and Animal Products ANIMAL AND PLANT... on live or dead animals, and will base the approval or disapproval of a test on the evaluation by...

  8. A prognostic scoring system for arm exercise stress testing.

    Science.gov (United States)

    Xie, Yan; Xian, Hong; Chandiramani, Pooja; Bainter, Emily; Wan, Leping; Martin, Wade H

    2016-01-01

    Arm exercise stress testing may be an equivalent or better predictor of mortality outcome than pharmacological stress imaging for the ≥50% for patients unable to perform leg exercise. Thus, our objective was to develop an arm exercise ECG stress test scoring system, analogous to the Duke Treadmill Score, for predicting outcome in these individuals. In this retrospective observational cohort study, arm exercise ECG stress tests were performed in 443 consecutive veterans aged 64.1 (11.1) years. (mean (SD)) between 1997 and 2002. From multivariate Cox models, arm exercise scores were developed for prediction of 5-year and 12-year all-cause and cardiovascular mortality and 5-year cardiovascular mortality or myocardial infarction (MI). Arm exercise capacity in resting metabolic equivalents (METs), 1 min heart rate recovery (HRR) and ST segment depression ≥1 mm were the stress test variables independently associated with all-cause and cardiovascular mortality by step-wise Cox analysis (all pstatistic of 0.81 before and 0.88 after adjustment for significant demographic and clinical covariates. Arm exercise scores for the other outcome end points yielded C-statistic values of 0.77-0.79 before and 0.82-0.86 after adjustment for significant covariates versus 0.64-0.72 for best fit pharmacological myocardial perfusion imaging models in a cohort of 1730 veterans who were evaluated over the same time period. Arm exercise scores, analogous to the Duke Treadmill Score, have good power for prediction of mortality or MI in patients who cannot perform leg exercise.

  9. The role of water channel proteins in facilitating recovery of leaf hydraulic conductance from water stress in Populus trichocarpa.

    Directory of Open Access Journals (Sweden)

    Joan Laur

    Full Text Available Gas exchange is constrained by the whole-plant hydraulic conductance (Kplant. Leaves account for an important fraction of Kplant and may therefore represent a major determinant of plant productivity. Leaf hydraulic conductance (Kleaf decreases with increasing water stress, which is due to xylem embolism in leaf veins and/or the properties of the extra-xylary pathway. Water flow through living tissues is facilitated and regulated by water channel proteins called aquaporins (AQPs. Here we assessed changes in the hydraulic conductance of Populus trichocarpa leaves during a dehydration-rewatering episode. While leaves were highly sensitive to drought, Kleaf recovered only 2 hours after plants were rewatered. Recovery of Kleaf was absent when excised leaves were bench-dried and subsequently xylem-perfused with a solution containing AQP inhibitors. We examined the expression patterns of 12 highly expressed AQP genes during a dehydration-rehydration episode to identify isoforms that may be involved in leaf hydraulic adjustments. Among the AQPs tested, several genes encoding tonoplast intrinsic proteins (TIPs showed large increases in expression in rehydrated leaves, suggesting that TIPs contribute to reversing drought-induced reductions in Kleaf. TIPs were localized in xylem parenchyma, consistent with a role in facilitating water exchange between xylem vessels and adjacent living cells. Dye uptake experiments suggested that reversible embolism formation in minor leaf veins contributed to the observed changes in Kleaf.

  10. The role of water channel proteins in facilitating recovery of leaf hydraulic conductance from water stress in Populus trichocarpa.

    Science.gov (United States)

    Laur, Joan; Hacke, Uwe G

    2014-01-01

    Gas exchange is constrained by the whole-plant hydraulic conductance (Kplant). Leaves account for an important fraction of Kplant and may therefore represent a major determinant of plant productivity. Leaf hydraulic conductance (Kleaf) decreases with increasing water stress, which is due to xylem embolism in leaf veins and/or the properties of the extra-xylary pathway. Water flow through living tissues is facilitated and regulated by water channel proteins called aquaporins (AQPs). Here we assessed changes in the hydraulic conductance of Populus trichocarpa leaves during a dehydration-rewatering episode. While leaves were highly sensitive to drought, Kleaf recovered only 2 hours after plants were rewatered. Recovery of Kleaf was absent when excised leaves were bench-dried and subsequently xylem-perfused with a solution containing AQP inhibitors. We examined the expression patterns of 12 highly expressed AQP genes during a dehydration-rehydration episode to identify isoforms that may be involved in leaf hydraulic adjustments. Among the AQPs tested, several genes encoding tonoplast intrinsic proteins (TIPs) showed large increases in expression in rehydrated leaves, suggesting that TIPs contribute to reversing drought-induced reductions in Kleaf. TIPs were localized in xylem parenchyma, consistent with a role in facilitating water exchange between xylem vessels and adjacent living cells. Dye uptake experiments suggested that reversible embolism formation in minor leaf veins contributed to the observed changes in Kleaf.

  11. Noninvasive electrical conductivity measurement by MRI. A test of its validity and the electrical conductivity characteristics of glioma

    Energy Technology Data Exchange (ETDEWEB)

    Tha, Khin Khin; Kudo, Kohsuke [Hokkaido University Hospital, Department of Diagnostic and Interventional Radiology, N-14, W-5, Kita-ku, Sapporo (Japan); Hokkaido University, Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education, Sapporo (Japan); Katscher, Ulrich; Stehning, Christian [Philips Research Laboratories, Hamburg (Germany); Yamaguchi, Shigeru; Terasaka, Shunsuke; Kazumata, Ken [Faculty of Medicine, Hokkaido University, Department of Neurosurgery, Sapporo (Japan); Fujima, Noriyuki [Hokkaido University Hospital, Department of Diagnostic and Interventional Radiology, N-14, W-5, Kita-ku, Sapporo (Japan); Yamamoto, Toru [Hokkaido University, Faculty of Health Sciences, Sapporo (Japan); Van Cauteren, Marc [Clinical Science Philips Healthtech Asia Pacific, Tokyo (Japan); Shirato, Hiroki [Hokkaido University, Global Station for Quantum Medical Science and Engineering, Global Institution for Collaborative Research and Education, Sapporo (Japan); Faculty of Medicine, Hokkaido University, Department of Radiation Medicine, Sapporo (Japan)

    2018-01-15

    This study noninvasively examined the electrical conductivity (σ) characteristics of diffuse gliomas using MRI and tested its validity. MRI including a 3D steady-state free precession (3D SSFP) sequence was performed on 30 glioma patients. The σ maps were reconstructed from the phase images of the 3D SSFP sequence. The σ histogram metrics were extracted and compared among the contrast-enhanced (CET) and noncontrast-enhanced tumour components (NCET) and normal brain parenchyma (NP). Difference in tumour σ histogram metrics among tumour grades and correlation of σ metrics with tumour grades were tested. Validity of σ measurement using this technique was tested by correlating the mean tumour σ values measured using MRI with those measured ex vivo using a dielectric probe. Several σ histogram metrics of CET and NCET of diffuse gliomas were significantly higher than NP (Bonferroni-corrected p ≤.045). The maximum σ of NCET showed a moderate positive correlation with tumour grade (r =.571, Bonferroni-corrected p =.018). The mean tumour σ measured using MRI showed a moderate positive correlation with the σ measured ex vivo (r =.518, p =.040). Tissue σ can be evaluated using MRI, incorporation of which may better characterise diffuse gliomas. (orig.)

  12. Critical assessment of precracked specimen configuration and experimental test variables for stress corrosion testing of 7075-T6 aluminum alloy plate

    Science.gov (United States)

    Domack, M. S.

    1985-01-01

    A research program was conducted to critically assess the effects of precracked specimen configuration, stress intensity solutions, compliance relationships and other experimental test variables for stress corrosion testing of 7075-T6 aluminum alloy plate. Modified compact and double beam wedge-loaded specimens were tested and analyzed to determine the threshold stress intensity factor and stress corrosion crack growth rate. Stress intensity solutions and experimentally determined compliance relationships were developed and compared with other solutions available in the literature. Crack growth data suggests that more effective crack length measurement techniques are necessary to better characterize stress corrosion crack growth. Final load determined by specimen reloading and by compliance did not correlate well, and was considered a major source of interlaboratory variability. Test duration must be determined systematically, accounting for crack length measurement resolution, time for crack arrest, and experimental interferences. This work was conducted as part of a round robin program sponsored by ASTM committees G1.06 and E24.04 to develop a standard test method for stress corrosion testing using precracked specimens.

  13. Stress Testing of Organic Light- Emitting Diode Panels and Luminaires

    Energy Technology Data Exchange (ETDEWEB)

    Lynn Davis, Kelley Rountree, Karmann Mills

    2018-01-31

    This report builds on previous DOE efforts with OLED technology by updating information on a previously benchmarked OLED product (the Chalina luminaire from Acuity Brands) and provides new benchmarks on the performance of Brite 2 and Brite Amber OLED panels from OLEDWorks. During the tests described here, samples of these devices were subjected to continuous operation in stress tests at elevated ambient temperature environments of 35°C or 45°C. In addition, samples were also operated continuously at room temperature in a room temperature operational life test (RTOL). One goal of this study was to investigate whether these test conditions can accelerate failure of OLED panels, either through panel shorting or an open circuit in the panel. These stress tests are shown to provide meaningful acceleration of OLED failure modes, and an acceleration factor of 2.6 was calculated at 45°C for some test conditions. In addition, changes in the photometric properties of the emitted light (e.g., luminous flux and chromaticity maintenance) was also evaluated for insights into the long-term stability of these products compared to earlier generations. Because OLEDs are a lighting system, electrical testing was also performed on the panel-driver pairs to provide insights into the impact of the driver on long-term panel performance.

  14. Perforation of dental gloves during prosthodontic treatments as assessed by the conductivity and water inflation tests.

    Science.gov (United States)

    Nikawa, H; Hamada, T; Tamamoto, M; Abekura, H; Murata, H

    1996-01-01

    The incidence of latex glove perforation during prosthodontic treatment was investigated on 122 occasions using two methods, a conductivity test and a water inflation test. Latex glove perforation was detected in 38.5% of the treatments by the conductivity test and in 27.9% by the water inflation test. The perforation went unrecognized in 74.7% of the occurrences (35/47 incidents) using the conductivity test and in 64.7% (22/34) when the water inflation test was used. Of the total 55 glove perforations, 21 perforations were detected only by conductivity test, 3 were detected only by the water inflation test, and 31 perforations were detected by both methods, which suggested that the conductivity test is more sensitive than the water inflation test for the detection of glove perforation. The results of this research suggested that even when latex gloves are worn, the risk to prosthodontists of exposure to body fluids remains in four of every six treatments, often without the awareness of the prosthodontist.

  15. Impulsivity and Stress Response in Pathological Gamblers During the Trier Social Stress Test

    NARCIS (Netherlands)

    Maniaci, G.; Goudriaan, A. E.; Cannizzaro, C.; van Holst, R. J.

    2017-01-01

    Gambling has been associated with increased sympathetic nervous system output and stimulation of the hypothalamic-pituitary-adrenal axis. However it is unclear how these systems are affected in pathological gambling. This study aimed to investigate the effect of the Trier Social Stress Test (TSST)

  16. 40 CFR 63.5992 - When must I conduct subsequent performance tests?

    Science.gov (United States)

    2010-07-01

    ... performance tests? 63.5992 Section 63.5992 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... CATEGORIES National Emissions Standards for Hazardous Air Pollutants: Rubber Tire Manufacturing General Testing and Initial Compliance Requirements § 63.5992 When must I conduct subsequent performance tests? If...

  17. 40 CFR 60.2155 - May I conduct performance testing less often?

    Science.gov (United States)

    2010-07-01

    ... performance test. (c) If a performance test shows a deviation from an emission limitation for particulate... 40 Protection of Environment 6 2010-07-01 2010-07-01 false May I conduct performance testing less... PROGRAMS (CONTINUED) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for...

  18. Comparison of Nerve Excitability Testing, Nerve Conduction Velocity, and Behavioral Observations for Acrylamide Induced Peripheral Neuropathy

    Science.gov (United States)

    Nerve excitability (NE) testing is a sensitive method to test for peripheral neurotoxicity in humans,and may be more sensitive than compound nerve action potential (CNAP) or nerve conduction velocity (NCV).We used acrylamide to compare the NE and CNAP/NCV methods. Behavioral test...

  19. Uniaxial stress influence on electrical conductivity of thin epitaxial lanthanum-strontium manganite films

    Energy Technology Data Exchange (ETDEWEB)

    Stankevič, V., E-mail: wstan@pfi.lt [Center for Physical Sciences and Technology, Semiconductor Physics Institute, A.Gostauto 11, Vilnius (Lithuania); Vilnius Gediminas Technical University, Sauletekio 11, Vilnius (Lithuania); Šimkevičius, Č.; Balevičius, S.; Žurauskienė, N. [Center for Physical Sciences and Technology, Semiconductor Physics Institute, A.Gostauto 11, Vilnius (Lithuania); Vilnius Gediminas Technical University, Sauletekio 11, Vilnius (Lithuania); Cimmperman, P. [Center for Physical Sciences and Technology, Semiconductor Physics Institute, A.Gostauto 11, Vilnius (Lithuania); Abrutis, A. [Vilnius University, Dept. of General and Inorganic Chemistry, Naugarduko 24, Vilnius (Lithuania); Plaušinaitienė, V. [Center for Physical Sciences and Technology, Semiconductor Physics Institute, A.Gostauto 11, Vilnius (Lithuania); Vilnius University, Dept. of General and Inorganic Chemistry, Naugarduko 24, Vilnius (Lithuania)

    2013-07-01

    This is a study of the influence of external uniaxial mechanical strains on the transport properties of thin epitaxial La{sub 0.83}Sr{sub 0.17}MnO{sub 3} (LSMO) films. Our measurements were carried out using standard isosceles triangle-shaped cantilever. Films which were tensed in-plane or compressed or were subjected to both tension and compression strains were grown onto SrTiO{sub 3} (STO), LaAlO{sub 3} (LAO) and (001) NdGaO{sub 3} (NGO) substrates, respectively. It was found that for thin films (less than 100 nm), the uniaxial compression of such films which were initially tensed in-plane (grown onto STO substrates) produces a decrease of their resistance, whereas the compression of initially compressed films (on LAO substrates) produces an increase of the films' resistance. The same results were obtained for LSMO films grown onto (001) NGO substrates when they were compressed along the [010] and [100] directions, respectively. For thicker films (more than 100 nm), the resistance behavior after uniaxial compression was found to be identical to that produced by hydrostatic compression, namely, the resistance decreases irrespective of the substrate. These experiments also reveal an increase of resistance and a shift of metal–insulator transition temperature T{sub m} to lower temperatures corresponding to a decrease of the film thickness. The occurrence of this effect is also independent of the kind of substrate used. Thus it was concluded that the influence of film thickness on its resistance as well as on the behavior of such films while under external uniaxial compression cannot be explained fully by only the presence of residual stress in these films. A possible reason is that the inhomogeneous distribution of the mechanical stresses in the films can lead to the appearance of two conductivity phases, each having a different mechanism. The results which were obtained when these films were subjected to hydrostatic compression were also explained by this

  20. Comparison of Domestic Safety Review and European Union(EU) Stress Test After Nuclear Accident in Fukushima Daiichi NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hwa Sung; Kim, Jin Weon [Chosun University, Gwangju (Korea, Republic of)

    2016-05-15

    The European Union(EU) nuclear regulators group established stress test criteria and procedures, and utilities performed a self-review in accordance with those criteria and procedures. For Wolsung nuclear unit-1,the stress test was additionally conducted for deciding the continued operation of NPP, even though the safety review had been conducted after Fukushima NPP accident. Thus, this study is to compares the process, criteria, and results of the safety review performed in domestic NPPs and EU stress test performed in Cernavoda NPP. From the comparisons, the effectiveness and necessity of the stress test to decide the continued operation of NPPs is discussed. and the improvement items for safety enhancement are derived. The comparison showed that the process and review criteria of EU stress test was more systematic and specific than those used in domestic NPPs. But it was indicated that the improvement items resulted from the safety review performed in domestic NPPs are more comprehensive and powerful than EU stress tests (Cernavoda NPP) results. EU stress test for Cernavoda NPP evaluated in 3 fieldsand derived 13 design change items. The 50 improvement items derived from domestic safety review were including the contents of these 13 items.

  1. A test case of the deformation rate analysis (DRA) stress measurement method

    Energy Technology Data Exchange (ETDEWEB)

    Dight, P.; Hsieh, A. [Australian Centre for Geomechanics, Univ. of WA, Crawley (Australia); Johansson, E. [Saanio and Riekkola Oy, Helsinki (Finland); Hudson, J.A. [Rock Engineering Consultants (United Kingdom); Kemppainen, K.

    2012-01-15

    As part of Posiva's site and ONKALO investigations, the in situ rock stress has been measured by a variety of techniques, including hydraulic fracturing, overcoring, and convergence measurements. All these techniques involve direct measurements in a drillhole or at the rock surface. An alternative method is to test drillhole core in a way that enables estimation of the magnitudes and orientations of the in situ rock stress. The Kaiser Effect (KE) and Deformation Rate Analysis (DRA) are two ways to do this. In the work reported here, a 'blind' DRA test was conducted on core obtained from the POSE (Posiva's Olkiluoto Spalling Experiment) niche in the ONKALO. The term 'blind' means that the two first authors of this report, who conducted the tests at the Australian Centre for Geomechanics, did not know the depths below surface at which the cores had been obtained. The results of this DRA Test Case are presented, together with an explanation of the DRA procedure. Also, additional information that would help in such DRA testing and associated analysis is explained. One of the problems in comparing the DRA results with the known Olkiluoto stress field is that the latter is highly variable across the site, as experienced by the previous in situ stress measurements and as predicted by numerical analysis. The variability is mainly caused by the presence of the large brittle deformation zones which perturb the local stress state. However, this variability reduces with depth and the stress field becomes more stable at the {approx} 350 m at which the drillhole cores were obtained. Another compounding difficulty is that the stress quantity, being a second order tensor, requires six independent components for its specification. In other words, comparison of the DRA results and the known stress field requires comparison of six different quantities. In terms of the major principal stress orientation, the DRA results predict an orientation completely

  2. A test case of the deformation rate analysis (DRA) stress measurement method

    International Nuclear Information System (INIS)

    Dight, P.; Hsieh, A.; Johansson, E.; Hudson, J.A.; Kemppainen, K.

    2012-01-01

    As part of Posiva's site and ONKALO investigations, the in situ rock stress has been measured by a variety of techniques, including hydraulic fracturing, overcoring, and convergence measurements. All these techniques involve direct measurements in a drillhole or at the rock surface. An alternative method is to test drillhole core in a way that enables estimation of the magnitudes and orientations of the in situ rock stress. The Kaiser Effect (KE) and Deformation Rate Analysis (DRA) are two ways to do this. In the work reported here, a 'blind' DRA test was conducted on core obtained from the POSE (Posiva's Olkiluoto Spalling Experiment) niche in the ONKALO. The term 'blind' means that the two first authors of this report, who conducted the tests at the Australian Centre for Geomechanics, did not know the depths below surface at which the cores had been obtained. The results of this DRA Test Case are presented, together with an explanation of the DRA procedure. Also, additional information that would help in such DRA testing and associated analysis is explained. One of the problems in comparing the DRA results with the known Olkiluoto stress field is that the latter is highly variable across the site, as experienced by the previous in situ stress measurements and as predicted by numerical analysis. The variability is mainly caused by the presence of the large brittle deformation zones which perturb the local stress state. However, this variability reduces with depth and the stress field becomes more stable at the ∼ 350 m at which the drillhole cores were obtained. Another compounding difficulty is that the stress quantity, being a second order tensor, requires six independent components for its specification. In other words, comparison of the DRA results and the known stress field requires comparison of six different quantities. In terms of the major principal stress orientation, the DRA results predict an orientation completely different to the NW-SE regional

  3. Biological and psychological markers of stress in humans: focus on the Trier Social Stress Test.

    Science.gov (United States)

    Allen, Andrew P; Kennedy, Paul J; Cryan, John F; Dinan, Timothy G; Clarke, Gerard

    2014-01-01

    Validated biological and psychological markers of acute stress in humans are an important tool in translational research. The Trier Social Stress Test (TSST), involving public interview and mental arithmetic performance, is among the most popular methods of inducing acute stress in experimental settings, and reliably increases hypothalamic-pituitary-adrenal axis activation. However, although much research has focused on HPA axis activity, the TSST also affects the sympathetic-adrenal-medullary system, the immune system, cardiovascular outputs, gastric function and cognition. We critically assess the utility of different biological and psychological markers, with guidance for future research, and discuss factors which can moderate TSST effects. We outline the effects of the TSST in stress-related disorders, and if these responses can be abrogated by pharmacological and psychological treatments. Modified TSST protocols are discussed, and the TSST is compared to alternative methods of inducing acute stress. Our analysis suggests that multiple readouts are necessary to derive maximum information; this strategy will enhance our understanding of the psychobiology of stress and provide the means to assess novel therapeutic agents. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Major outcomes of the stress tests. Learning from each other

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2013-11-15

    Performed by the EU's 'nuclear' member states plus Switzerland and Ukraine, the European stress tests were carried out with some differences, notably in the scope considered. The action plans derived from the conclusions of the national reports peer-reviewed by TSO experts also differ in terms of scope, priorities and scheduling. Similar safety reassessments were performed in other countries such as Japan or Russia. The country-specific focuses described below provide an overview of the similarities and dissimilarities between twelve countries which are represented at EUROSAFE. One common denominator among them might be the fact that the conclusions from the stress tests did not reveal any major deficiency calling for immediate steps to be taken. (orig.)

  5. Effects of combined drought and heavy metal stresses on xylem structure and hydraulic conductivity in red maple (Acer rubrum L.).

    Science.gov (United States)

    de Silva, Nayana Dilini Gardiyehewa; Cholewa, Ewa; Ryser, Peter

    2012-10-01

    The effects of heavy metal stress, drought stress, and their combination on xylem structure in red maple (Acer rubrum) seedlings were investigated in an outdoor pot experiment. As metal-contaminated substrate, a mixture of 1.5% slag with sand was used, with Ni, Cu, Co, and Cr as the main contaminants. Plants grown on contaminated substrate had increased leaf metal concentrations. The two stresses reduced plant growth in an additive manner. The effects of metal and drought stresses on xylem characteristics were similar to each other, with a reduced proportion of xylem tissue, reduced conduit density in stems, and reduced conduit size in the roots. This resulted, in both stems and roots, in reductions in hydraulic conductance, xylem-specific conductivity, and leaf-specific conductivity. The similarity of the responses to the two stresses suggests that the plants' response to metals was actually a drought response, probably due to the reduced water uptake capacity of the metal-exposed roots. The only plant responses specific to metal stress were decreasing trends of stomatal density and chlorophyll content. In conclusion, the exposure to metals aggravates water stress in an additive manner, making the plants more vulnerable to drought.

  6. INTERFACE DEVICE FOR NONDESTRUCTIVE TESTING OF RESIDUAL SURFACE STRESSES

    Directory of Open Access Journals (Sweden)

    Gennady A. Perepelkin

    2016-01-01

    Full Text Available The paper considers the organization of connection of a personal computer with a device for nondestructive testing of residual surface stresses. The device works is based on the phenomenon of diffraction of ionizing radiation from the crystal lattice near the surface of the crystallites. Proposed software interface to the organization for each type of user: the device developers, administrators, users. Some aspects of the organization of communication microcontroller to a PC via USB-port

  7. Research Problems Associated with Limiting the Applied Force in Vibration Tests and Conducting Base-Drive Modal Vibration Tests

    Science.gov (United States)

    Scharton, Terry D.

    1995-01-01

    The intent of this paper is to make a case for developing and conducting vibration tests which are both realistic and practical (a question of tailoring versus standards). Tests are essential for finding things overlooked in the analyses. The best test is often the most realistic test which can be conducted within the cost and budget constraints. Some standards are essential, but the author believes more in the individual's ingenuity to solve a specific problem than in the application of standards which reduce problems (and technology) to their lowest common denominator. Force limited vibration tests and base-drive modal tests are two examples of realistic, but practical testing approaches. Since both of these approaches are relatively new, a number of interesting research problems exist, and these are emphasized herein.

  8. SFC/SFBMN guidelines update for nuclear cardiology procedures: stress testing in adults and children

    International Nuclear Information System (INIS)

    Manrique, A.; Marie, P.Y.; Maunoury, Ch.; Acar, Ph.; Agostini, D.

    2002-01-01

    The guidelines update for nuclear cardiology procedures are studied in this article. We find the minimum technique conditions for the stress testing practice, the recommendations for the different ischemia activation tests, the choice of the stress test. (N.C.)

  9. Rapid microbiological testing: monitoring the development of bacterial stress.

    Directory of Open Access Journals (Sweden)

    Boris Zavizion

    2010-10-01

    Full Text Available The ability to respond to adverse environments effectively along with the ability to reproduce are sine qua non conditions for all sustainable cellular forms of life. Given the availability of an appropriate sensing modality, the ubiquity and immediacy of the stress response could form the basis for a new approach for rapid biological testing. We have found that measuring the dielectric permittivity of a cellular suspension, an easily measurable electronic property, is an effective way to monitor the response of bacterial cells to adverse conditions continuously. The dielectric permittivity of susceptible and resistant strains of Escherichia coli and Staphylococcus aureus, treated with gentamicin and vancomycin, were measured directly using differential impedance sensing methods and expressed as the Normalized Impedance Response (NIR. These same strains were also heat-shocked and chemically stressed with Triton X-100 or H(2O(2. The NIR profiles obtained for antibiotic-treated susceptible organisms showed a strong and continuous decrease in value. In addition, the intensity of the NIR value decrease for susceptible cells varied in proportion to the amount of antibiotic added. Qualitatively similar profiles were found for the chemically treated and heat-shocked bacteria. In contrast, antibiotic-resistant cells showed no change in the NIR values in the presence of the drug to which it is resistant. The data presented here show that changes in the dielectric permittivity of a cell suspension are directly correlated with the development of a stress response as well as bacterial recovery from stressful conditions. The availability of a practical sensing modality capable of monitoring changes in the dielectric properties of stressed cells could have wide applications in areas ranging from the detection of bacterial infections in clinical specimens to antibiotic susceptibility testing and drug discovery.

  10. 30 CFR 250.407 - What tests must I conduct to determine reservoir characteristics?

    Science.gov (United States)

    2010-07-01

    ... Gas Drilling Operations General Requirements § 250.407 What tests must I conduct to determine... of oil, gas, sulphur, and water in the formations penetrated by logging, formation sampling, or well...

  11. Test of Association Between 10 SNPs in the Oxytocin Receptor Gene and Conduct Disorder

    OpenAIRE

    Sakai, Joseph T.; Crowley, Thomas J.; Stallings, Michael C.; McQueen, Matthew; Hewitt, John K.; Hopfer, Christian; Hoft, Nicole R.; Ehringer, Marissa A.

    2012-01-01

    Animal and human studies have implicated oxytocin (OXT) in affiliative and prosocial behaviors. We tested whether genetic variation in the OXT receptor (OXTR) gene is associated with conduct disorder (CD).

  12. Development of Chinese HTR-PM pebble bed equivalent conductivity test facility

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Cheng; Yang, Xingtuan; Jiang, Shengyao [Tsinghua Univ., Beijing (China). Inst. of Nuclear and New Energy Technology

    2016-01-15

    The first two 250-MWt high-temperature reactor pebble bed modules (HTR-PM) have been installing at the Shidaowan plant in Shandong Province, China. The values of the effective thermal conductivity of the pebble bed core are essential parameters for the design. For their determination, Tsinghua University in China has proposed a full-scale heat transfer experiment to conduct comprehensive thermal transfer tests in packed pebble bed and to determine the effective thermal conductivity.

  13. Residual radioactive contamination of the test site at Emu from nuclear weapons tests conducted in 1953

    International Nuclear Information System (INIS)

    Maclagan, D.S.; Cooper, M.B.; Duggleby, J.C.

    1979-08-01

    The detailed distributions and soil concentrations of long-lived radionuclides remaining from nuclear weapons trials conducted at Emu in October 1953, are presented. Significant radiation levels due to long-lived neutron activation products in soil, 60 Co and 152 Eu, occur only in the immediate vicinity of the ground zeros of TOTEM 1 and TOTEM 2. It is shown that the levels of contamination due to fallout products in the soil are well below those which would constitute a health hazard to occupants of the area

  14. European stress tests for nuclear power plants. The Swedish National Report

    International Nuclear Information System (INIS)

    2011-01-01

    On 11 March 2011, the Tohoku region in north Honshu, Japan, suffered a severe earthquake with an ensuing tsunami and an accident at the Fukushima Dai-ichi nuclear power plant. Due to the accident the Council of the European Union declared in late March that Member States were prepared to begin reviewing safety at nuclear facilities in the European Union by means of a comprehensive assessment of risk and safety ('stress testing'). On 25 May, SSM ordered the licensees of the nuclear power plants to conduct renewed analyses of the facilities' resilience against different kinds of natural phenomena. They were also to analyse how the facilities would be capable of dealing with a prolonged loss of electrical power, regardless of cause. On 31 October, the licensees reported on their stress tests to SSM. After reviewing these reports, SSM produced a summary stress test report, which was submitted to the Government on the 15 December. The present report is the national report on Swedish stress tests of nuclear power plants. The report will be submit to the European Commission no later than 31 December. Based on the review SSM has drawn the conclusion that the stress tests carried out by Swedish licensees are largely performed in accordance with the specification resolved within the European Union. The scope and depth of these analyses and assessments are essentially in accordance with ENSREG's definition of 'a comprehensive assessment of risk and safety'. The stress tests show that Swedish facilities are robust, but the tests also identify a number of opportunities to further strengthen the facilities' robustness. SSM will order the respective licensees to present an action plan for dealing with the results from the stress tests. The Authority will then examine the plans and adopt a standpoint on proposed measures as well as check that the necessary safety improvements are made. In a number of cases, the stress tests indicate deficiencies in relation to, or alternatively

  15. LMFBR safety: Interim test report for the characterization of released particle tests conducted at INEL during FY 1979

    International Nuclear Information System (INIS)

    Johnson, R.P.; Nelson, C.T.

    1979-01-01

    Two additional atmospheric sodium release tests were jointly conducted by ESG and ARL at INEL. These tests were conducted under very stable (Pasquill E and G) meteorological conditions where the natural humidity content was high (47 and 96% RH). Sufficient experimental data was obtained on Test 7 to quantitatively qualify the formation of Na 2 CO 3 in the open atmosphere from primary sodium combustion products. These data show that a maximum concentration of approx. 60% Na 2 CO 3 is reached with the plume 100 meters from the release point. This concentration increases slightly as the plume is dispersed beyond 2400 meters. The available particle fallout data is consistent with predictions

  16. Accelerated stress testing of amorphous silicon solar cells

    Science.gov (United States)

    Stoddard, W. G.; Davis, C. W.; Lathrop, J. W.

    1985-01-01

    A technique for performing accelerated stress tests of large-area thin a-Si solar cells is presented. A computer-controlled short-interval test system employing low-cost ac-powered ELH illumination and a simulated a-Si reference cell (seven individually bandpass-filtered zero-biased crystalline PIN photodiodes) calibrated to the response of an a-Si control cell is described and illustrated with flow diagrams, drawings, and graphs. Preliminary results indicate that while most tests of a program developed for c-Si cells are applicable to a-Si cells, spurious degradation may appear in a-Si cells tested at temperatures above 130 C.

  17. Child/Adolescent’s ADHD and Parenting Stress: The Mediating Role of Family Impact and Conduct Problems

    Science.gov (United States)

    Muñoz-Silva, Alicia; Lago-Urbano, Rocio; Sanchez-Garcia, Manuel; Carmona-Márquez, José

    2017-01-01

    Objective: The demands of parenting are usually associated with some stress, and elevated levels of stress may affect the parent–child relationships and parenting practices. This is especially the case of families where children have special needs conditions or disorders, like Attention Deficit Hyperactivity Disorder (ADHD). Method: This study examined parenting stress among mothers of children and adolescents with ADHD. The sample comprised 126 mothers of girls (36; 29%) and boys (90; 71%) aged 6–17 years old. Results: Mothers reported their own stress levels as well as the children and adolescents’ variables (severity of their ADHD symptoms, conduct, and emotional problems) and family–contextual variables (negative impact on family’s social life, impact on couple relationship, and perceived social support). Hierarchical multiple regression showed that (a) negative impact on social life and conduct problems were the strongest predictors of mother’s stress. Bootstrap mediation analyses revealed that (b) the association between child and adolescent’s ADHD and parenting stress was mediated by children’s conduct problems and by negative impact on family’s social life, and not by children’s emotional problems nor by mother’s perceived social support. The mediation analysis also suggested (c) a pathway from child/adolescent’s ADHD through children’s conduct problems and then through their negative impact on family’s social life to mother’s parenting stress. Conclusion: These results suggest that both child/adolescent’s and family factors should be considered in the designing of interventions for reducing parenting stress in families of children and adolescents with ADHD. PMID:29312090

  18. Child/Adolescent’s ADHD and Parenting Stress: The Mediating Role of Family Impact and Conduct Problems

    Directory of Open Access Journals (Sweden)

    Alicia Muñoz-Silva

    2017-12-01

    Full Text Available Objective: The demands of parenting are usually associated with some stress, and elevated levels of stress may affect the parent–child relationships and parenting practices. This is especially the case of families where children have special needs conditions or disorders, like Attention Deficit Hyperactivity Disorder (ADHD.Method: This study examined parenting stress among mothers of children and adolescents with ADHD. The sample comprised 126 mothers of girls (36; 29% and boys (90; 71% aged 6–17 years old.Results: Mothers reported their own stress levels as well as the children and adolescents’ variables (severity of their ADHD symptoms, conduct, and emotional problems and family–contextual variables (negative impact on family’s social life, impact on couple relationship, and perceived social support. Hierarchical multiple regression showed that (a negative impact on social life and conduct problems were the strongest predictors of mother’s stress. Bootstrap mediation analyses revealed that (b the association between child and adolescent’s ADHD and parenting stress was mediated by children’s conduct problems and by negative impact on family’s social life, and not by children’s emotional problems nor by mother’s perceived social support. The mediation analysis also suggested (c a pathway from child/adolescent’s ADHD through children’s conduct problems and then through their negative impact on family’s social life to mother’s parenting stress.Conclusion: These results suggest that both child/adolescent’s and family factors should be considered in the designing of interventions for reducing parenting stress in families of children and adolescents with ADHD.

  19. Development, manufacturing and testing of a gas-loaded variable conductance methanol heat pipe

    Science.gov (United States)

    Vanbuggenum, R. I. J.; Daniels, D. H. W.

    1987-02-01

    The experimental technology required to measure the performance of moderate temperature heat pipes is presented. The heat pipe manufacturing process is described. The hydrodynamic characteristics of the porous structure inside the heat pipe envelope were examined using a specially developed test rig, based upon a steady-state evaporation test. A fully automated test facility was developed and validated by testing constant conductance and variable conductance heat pipes (VCHP). Theoretical performance predictions are illustrated in terms of pressure, depicted in 3D-plots, and compared with the test results of the heat pipe performance tests. The design of the VCHP was directed towards the verification of the VCHP mathematical model. The VCHP design is validated and ready for the final testing and model verification.

  20. Economic Deprivation and Its Effects on Childhood Conduct Problems: The Mediating Role of Family Stress and Investment Factors

    Directory of Open Access Journals (Sweden)

    Edward M. Sosu

    2017-09-01

    Full Text Available This study investigated the mechanisms by which experiences of poverty influence the trajectory of conduct problems among preschool children. Drawing on two theoretical perspectives, we focused on family stress (stress and harsh discipline and investment variables (educational investment, nutrition, and cognitive ability as key mediators. Structural equation modeling techniques with prospective longitudinal data from the Growing Up in Scotland survey (N = 3,375 were used. Economic deprivation measured around the first birthday of the sample children had both direct and indirect effects on conduct problems across time (ages 4, 5, and 6. In line with the family stress hypothesis, higher levels of childhood poverty predicted conduct problems across time through increased parental stress and punitive discipline. Consistent with the investment model, childhood deprivation was associated with higher levels of conduct problems via educational investment and cognitive ability. The study extends previous knowledge on the mechanisms of this effect by demonstrating that cognitive ability is a key mediator between poverty and the trajectory of childhood conduct problems. This suggests that interventions aimed at reducing child conduct problems should be expanded to include factors that compromise parenting as well as improve child cognitive ability.

  1. Conducting Closed Habitation Experiments: Experience from the Lunar Mars Life Support Test Project

    Science.gov (United States)

    Barta, Daniel J.; Edeen, Marybeth A.; Henninger, Donald L.

    2006-01-01

    The Lunar-Mars Life Support Test Project (LMLSTP) was conducted from 1995 through 1997 at the National Aeronautics and Space Administration s (NASA) Johnson Space Center (JSC) to demonstrate increasingly longer duration operation of integrated, closed-loop life support systems that employed biological and physicochemical techniques for water recycling, waste processing, air revitalization, thermal control, and food production. An analog environment for long-duration human space travel, the conditions of isolation and confinement also enabled studies of human factors, medical sciences (both physiology and psychology) and crew training. Four tests were conducted, Phases I, II, IIa and III, with durations of 15, 30, 60 and 91 days, respectively. The first phase focused on biological air regeneration, using wheat to generate enough oxygen for one experimental subject. The systems demonstrated in the later phases were increasingly complex and interdependent, and provided life support for four crew members. The tests were conducted using two human-rated, atmospherically-closed test chambers, the Variable Pressure Growth Chamber (VPGC) and the Integrated Life Support Systems Test Facility (ILSSTF). Systems included test articles (the life support hardware under evaluation), human accommodations (living quarters, kitchen, exercise equipment, etc.) and facility systems (emergency matrix system, power, cooling, etc.). The test team was managed by a lead engineer and a test director, and included test article engineers responsible for specific systems, subsystems or test articles, test conductors, facility engineers, chamber operators and engineering technicians, medical and safety officers, and science experimenters. A crew selection committee, comprised of psychologists, engineers and managers involved in the test, evaluated male and female volunteers who applied to be test subjects. Selection was based on the skills mix anticipated for each particular test, and utilized

  2. STRESS TESTS FOR VIDEOSTREAMING SERVICES BASED ON RTSP PROTOCOL

    Directory of Open Access Journals (Sweden)

    Gabriel Elías Chanchí Golondrino

    2015-11-01

    Full Text Available Video-streaming is a technology with major implications these days in such diverse contexts as education, health and the business sector; all of this regarding the ease it provides for remote access to live or recorded media content, allowing communication regardless of geographic location. One standard protocol that enables implementation of this technology is real time streaming protocol, or RTSP. However, since most application servers and Internet services are supported on HTTP requests, very little research has been done on generating tools for carrying out stress tests on streaming servers. This paper presents a stress measuring tool called Hermes, developed in Python, which allows calculation of response times for establishing RTSP connections to streaming servers, as well as obtaining RAM memory consumption and CPU usage rate data from these servers. Hermes was deployed in a video-streaming environment where stress testing was carried out on the LIVE555 server, using calls in the background to VLC and OpenRTSP open source clients. 

  3. Stress corrosion cracking tests on high-level-waste container materials in simulated tuff repository environments

    International Nuclear Information System (INIS)

    Abraham, T.; Jain, H.; Soo, P.

    1986-06-01

    Types 304L, 316L, and 321 austenitic stainless steel and Incoloy 825 are being considered as candidate container materials for emplacing high-level waste in a tuff repository. The stress corrosion cracking susceptibility of these materials under simulated tuff repository conditions was evaluated by using the notched C-ring method. The tests were conducted in boiling synthetic groundwater as well as in the steam/air phase above the boiling solutions. All specimens were in contact with crushed Topopah Spring tuff. The investigation showed that microcracks are frequently observed after testing as a result of stress corrosion cracking or intergranular attack. Results showing changes in water chemistry during test are also presented

  4. Simulated Service and Stress Corrosion Cracking Testing for Friction Stir Welded Spun Formed Domes

    Science.gov (United States)

    Stewart, Thomas J.; Torres, Pablo D.; Caratus, Andrei A.; Curreri, Peter A.

    2010-01-01

    Simulated service testing (SST) development was required to help qualify a new 2195 aluminum lithium (Al-Li) alloy spin forming dome fabrication process for the National Aeronautics and Space Administration (NASA) Exploration Development Technology Program. The application for the technology is to produce high strength low weight tank components for NASA s next generation launch vehicles. Since plate material is not currently manufactured large enough to fabricate these domes, two plates are joined by means of friction stir welding. The plates are then pre-contour machined to near final thicknesses allowing for a thicker weld land and anticipating the level of stretch induced by the spin forming process. The welded plates are then placed in a spin forming tool and hot stretched using a trace method producing incremental contours. Finally the dome receives a room temperature contour stretch to final dimensions, heat treatment, quenching, and artificial aging to emulate a T-8 condition of temper. Stress corrosion cracking (SCC) tests were also performed by alternate immersion in a sodium chloride (NaCl) solution using the typical double beam assembly and with 4-point loaded specimens and use of bent-beam stress-corrosion test specimens under alternate immersion conditions. In addition, experiments were conducted to determine the threshold stress intensity factor for SCC (K(sub ISCC)) which to our knowledge has not been determined previously for Al-Li 2195 alloy. The successful simulated service and stress corrosion testing helped to provide confidence to continue to Ares 1 scale dome fabrication

  5. Optimal Constant-Stress Accelerated Degradation Test Plans Using Nonlinear Generalized Wiener Process

    Directory of Open Access Journals (Sweden)

    Zhen Chen

    2016-01-01

    Full Text Available Accelerated degradation test (ADT has been widely used to assess highly reliable products’ lifetime. To conduct an ADT, an appropriate degradation model and test plan should be determined in advance. Although many historical studies have proposed quite a few models, there is still room for improvement. Hence we propose a Nonlinear Generalized Wiener Process (NGWP model with consideration of the effects of stress level, product-to-product variability, and measurement errors for a higher estimation accuracy and a wider range of use. Then under the constraints of sample size, test duration, and test cost, the plans of constant-stress ADT (CSADT with multiple stress levels based on the NGWP are designed by minimizing the asymptotic variance of the reliability estimation of the products under normal operation conditions. An optimization algorithm is developed to determine the optimal stress levels, the number of units allocated to each level, inspection frequency, and measurement times simultaneously. In addition, a comparison based on degradation data of LEDs is made to show better goodness-of-fit of the NGWP than that of other models. Finally, optimal two-level and three-level CSADT plans under various constraints and a detailed sensitivity analysis are demonstrated through examples in this paper.

  6. Memory for objects and startle responsivity in the immediate aftermath of exposure to the Trier Social Stress Test.

    Science.gov (United States)

    Herten, Nadja; Pomrehn, Dennis; Wolf, Oliver T

    2017-05-30

    Previously, we observed enhanced long-term memory for objects used (central objects) by committee members in the Trier Social Stress Test (TSST) on the next day. In addition, startle responsivity was increased. However, response specificity to an odour involved in the stressful episode was lacking and recognition memory for the odour was poor. In the current experiments, immediate effects of the stressor on memory and startle responsivity were investigated. We hypothesised memory for central objects of the stressful episode and startle response specificity to an odour ambient during the TSST to be enhanced shortly after it, in contrast to the control condition (friendly TSST). Further, memory for this odour was also assumed to be increased in the stress group. We tested 70 male (35) and female participants using the TSST involving objects and an ambient odour. After stress induction, a startle paradigm including olfactory and visual stimuli was conducted. Indeed, memory for central objects was significantly enhanced in immediate aftermath of the stressor. Startle responsivity increased at a trend level, particularly with regard to the odour involved in the stressful episode. Moreover, the stress group descriptively tended towards a better recognition of the odour involved. The study shows that stress enhances memory for central aspects of a stressful situation before consolidation processes come into play. In addition, results preliminarily suggest that the impact of stress on startle responsivity increases in strength but decreases in specificity during the first 24h after stress exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. A Randomized Comparative Study Evaluating Various Cough Stress Tests and 24-Hour Pad Test with Urodynamics in the Diagnosis of Stress Urinary Incontinence.

    Science.gov (United States)

    Henderson, Joseph W; Kane, Sarah M; Mangel, Jeffrey M; Kikano, Elias G; Garibay, Jorge A; Pollard, Robert R; Mahajan, Sangeeta T; Debanne, Sara M; Hijaz, Adonis K

    2018-06-01

    The cough stress test is a common and accepted tool to evaluate stress urinary incontinence but there is no agreement on how the test should be performed. We assessed the diagnostic ability of different cough stress tests performed when varying patient position and bladder volume using urodynamic stress urinary incontinence as the gold standard. The 24-hour pad test was also evaluated. We recruited women who presented to specialty outpatient clinics with the complaint of urinary incontinence and who were recommended to undergo urodynamic testing. A total of 140 patients were randomized to 4 cough stress test groups, including group 1-a comfortably full bladder, group 2-an empty bladder, group 3- a bladder infused with 200 cc saline and group 4-a bladder filled to half functional capacity. The sequence of standing and sitting was randomly assigned. The groups were compared by 1-way ANOVA or the generalized Fisher exact test. The κ statistic was used to evaluate agreement between the sitting and standing positions. The 95% CIs of sensitivity and specificity were calculated using the Wilson method. ROC analysis was done to evaluate the performance of the 24-hour pad test. The cough stress test performed with a bladder filled to half functional capacity was the best performing test with 83% sensitivity and 90% specificity. There was no statistically significant evidence that the sensitivity or specificity of 1 cough stress test differed from that of the others. The pad test had no significant predictive ability to diagnose urodynamic stress urinary incontinence (AUC 0.60, p = 0.08). Cough stress tests were accurate to diagnose urodynamic stress urinary incontinence. The 24-hour pad test was not predictive of urodynamic stress urinary incontinence and not helpful when used in conjunction with the cough stress test. Copyright © 2018 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

  8. Hydrogeological study of single water conducting fracture using a crosshole hydraulic test apparatus

    International Nuclear Information System (INIS)

    Yamamoto, Hajime; Shimo, Michito; Yamamoto, Takuya

    1998-03-01

    The Crosshole Injection Test Apparatus has been constructed to evaluate the hydraulic properties and conditions, such as hydraulic conductivity and its anisotropy, storage coefficient, pore pressure etc. within a rock near a drift. The construction started in FY93 and completed on August FY96 as a set of equipments for the use of crosshole hydraulic test, which is composed of one injection borehole instrument, one observation borehole instrument and a set of on-ground instrument. In FY96, in-situ feasibility test was conducted at a 550 m level drift in Kamaishi In Situ Test Site which has been operated by PNC, and the performance of the equipment and its applicability to various types of injection method were confirmed. In this year, a hydrogeological investigation on the single water conducting fracture was conducted at a 250 m level drift in Kamaishi In Situ Test Site, using two boreholes, KCH-3 and KCH-4, both of which are 30 m depth and inclined by 45 degrees from the surface. Pressure responses at the KCH-3 borehole during the drilling of KCH-4 borehole, the results of Borehole TV logging and core observation indicated that a major conductive single-fracture was successfully isolated by the packers. As a result of a series of the single-hole and the crosshole tests (sinusoidal and constant flowrate test), the hydraulic parameters of the single-fracture (such as hydraulic conductivity and storage coefficient) were determined. This report shows all the test result, analysed data, and also describes the hydro-geological structure near the drift. (author)

  9. Cardiac stress test as a risk-stratification tool for posttransplant cardiac outcomes in diabetic kidney transplant recipients.

    Science.gov (United States)

    Singh, Neeraj; Parikh, Samir; Bhatt, Udayan; Vonvisger, Jon; Nori, Uday; Hasan, Ayesha; Samavedi, Srinivas; Andreoni, Kenneth; Henry, Mitchell; Pelletier, Ronald; Rajab, Amer; Elkhammas, Elmahdi; Pesavento, Todd

    2012-12-27

    The utility of cardiac stress testing as a risk-stratification tool before kidney transplantation remains debatable owing to discordance with coronary angiography and outcome yields at different centers. We conducted a retrospective study of 273 diabetic kidney transplant recipients from 2006 to 2010. By protocol, all diabetic patients underwent pharmacological radionucleotide stress test or dobutamine stress echocardiography before transplant. We compared the 1-year cardiac outcomes between those with negative stress test results and those with positive stress test results. Patients with a positive stress test result (n=67) underwent coronary angiogram, and significant coronary artery disease (≥70% coronary stenosis) was found in 35 (52.2%) patients. Of the latter, 32 (91.4%) underwent cardiac revascularization (24 underwent cardiac stenting and 8 underwent coronary artery bypass grafting). The rest (n=35) were treated medically. Within 1 year after transplant, the group with positive stress test results experienced more cardiac events (34.3% vs. 3.9%, P<0.001) including acute myocardial infarction (22.4% vs. 3.4%, P<0.001) and ventricular arrhythmias (8.9% vs. 0.05%, P=0.001), higher all-cause mortality (19.4% vs. 4.8%, P<0.001), and cardiac mortality (17.9% vs. 0.9%, P<0.001) compared with the group with negative stress test results. In this diabetic population, stress testing showed positive and negative predictive values of 34.3% and 96.1%, respectively. Pharmacological cardiac stress testing provided excellent risk stratification in diabetic kidney transplant recipients.

  10. Mediators of compassionate goal intervention effects on human neuroendocrine responses to the Trier Social Stress Test.

    Science.gov (United States)

    Erickson, Thane M; Mayer, Stefanie E; Lopez-Duran, Nestor L; Scarsella, Gina M; McGuire, Adam P; Crocker, Jennifer; Abelson, James L

    2017-11-01

    The hypothalamic-pituitary-adrenal (HPA) axis is thought to mediate the effects of stress on illness. Research has identified a limited number of psychological variables that modulate human HPA responses to stressors (e.g. perceived control and social support). Prosocial goals can reduce subjective stress, but have not been carefully examined in experimental settings where pathways of impact on biological stress markers may be traced. Recent work demonstrated that coaching individuals to strive to help others reduced HPA responses to the Trier Social Stress Test (TSST) relative to other cognitive interventions. However, identification of mediational pathways, which were not examined in the original study, is necessary to determine whether the HPA buffering effects were due to helping motivations (compassionate goals; CGs) rather than via previously identified variables such as control or support. In this new analysis, we combined the original cortisol data with novel observer ratings of interpersonal behavior and psychological variables during the stress task, and conducted new, theory-driven analyses to determine psychological mediators for the intervention's effect on cortisol responses (N = 54; 21 females, 33 males; 486 cortisol samples). Control, support, and task ego-threat failed to account for the effects of the intervention. As hypothesized, self and observer-rated CGs, as well as observer-rated perceptions of participants' interpersonal behavior as morally desirable (but not as dominant or affiliative) were significant mediators of neuroendocrine responses. The findings suggest that stress-reduction interventions based on prosocial behavior should target particular motivational and interpersonal features.

  11. Testing and Micromechanical Modelling of Rockfill Materials Considering the Effect of Stress Path

    Directory of Open Access Journals (Sweden)

    Wang Feng

    2016-01-01

    Full Text Available We have extended the micromechanics-based analytical (M-A model to make it capable of simulating Nuozhadu rockfill material (NRFM under different stress paths. Two types of drained triaxial tests on NRFM were conducted, namely, the stress paths of constant stress ratio (CSR and the complex stress paths with transitional features. The model was improved by considering the interparticle parameter variation with the unloading-reloading cycles and the effect of the stress transition path. The evolution of local dilatancy at interparticle planes due to an externally applied load is also discussed. Compared with Duncan-Chang’s E-u and E-B models, the improved model could not only better describe the deformation properties of NRFM under the stress path loading, but also present the volumetric strain changing from dilatancy to contractancy with increasing transitional confining pressures. All simulations have demonstrated that the proposed M-A model is capable of modelling the mechanical behaviour of NRFM in the dam.

  12. [Animal testing ethics and human testing. Thoughts on our conduct with and our relationship to animals].

    Science.gov (United States)

    Locker, Alfred

    2004-01-01

    After many years of experimental work with animals of diverse species, the author felt confronted with the question whether the great expenditure of sacrificed animal life would pay off when compared with the results gained. By self-critically considering his work, he gradually experienced a conversion from an unconcerned experimenter to a man feeling a deep sympathy with his fellow creatures. This motivated him to ponder the true nature of animals. Instead of applying ethics--though justified in its own realm--the author preferred to look at the problem using the General Systems Theory (GST), which can describe "the other side" of any system, the side into which any system may occasionally or necessarily transform. It occurred to him to assume that--provided we see a living organism as a system (as Ludwig von Bertalanffy, the founder of GST, did)--the "other side" of the animal would correspond to an innocent "genius" who suffers for man (thereby assuming a Christ-like position), whereas in its transitory life the true essence of the animal is hidden. Thus, by fancifully viewing the role of animals destined to suffer, a connection between GST and theology or religion arises. The consequence for us would be to pay honour to the test animal, irrespective of whether or not painful experiments could be avoided. The differentiation between a sacrifice (spiritually surrendering for a greater good) and a victim (involuntarily subjected to suffering) reveals that the experimental animal primarily belongs to the latter. But it can be elevated to the former when the full meaning of its suffering becomes obvious. The same holds true for "human testing", if, in contrast to the formidable atrocities, e.g. of concentration camps, the momentum of voluntariness is guaranteed, as pioneers of medical research frequently demonstrated by carrying out experiments on themselves.

  13. Stress Reactivity to an Electronic Version of the Trier Social Stress Test: A Pilot Study

    Directory of Open Access Journals (Sweden)

    Sage E Hawn

    2015-05-01

    Full Text Available Social stressors that rely on the inclusion of confederates (i.e., Trier Social Stress Test; TSST are often used in clinical laboratory research paradigms to elicit a measurable stress response in participants. Although effective, the TSST is labor intensive and may introduce error variance as a function of confederate race, gender, and/or response characteristics. The present study aimed to develop and validate an electronic version of the TSST (e-TSST. The primary aim was to compare the e-TSST to an e-neutral control condition; the exploratory aim was to compare the magnitude of stress response elicited by the e-TSST to that elicited by the traditional TSST. Forty-three healthy adults were randomized to the e-TSST or e-neutral condition. Subjective (participant-rated distress and objective (cortisol, heart rate and blood pressure indices of stress were collected prior to, and multiple times following, the stressor. Using archival data collected from 19 healthy participants exposed to the traditional TSST in a prior study, stress reactivity was compared between the electronic and traditional versions of the TSST. The e-TSST elicited significant increases in all measures of stress reactivity compared to the e-neutral condition, with the exception of heart rate (HR. Results showed that the magnitude of subjective distress, BP, and HR responses elicited by the e-TSST did not differ significantly from that elicited by the traditional TSST. The traditional TSST elicited significantly higher cortisol than the e-TSST. Although these findings provide initial support for the development of electronic versions of the TSST, further refinement of the e-TSST is warranted prior to broad adoption of this technology. A refined, reliable e-TSST could allow for increased utilization of the TSST by enhancing convenience, reducing labor costs, and limiting potential error variance introduced by human confederates.

  14. An accurately controllable imitative stress corrosion cracking for electromagnetic nondestructive testing and evaluations

    International Nuclear Information System (INIS)

    Yusa, Noritaka; Uchimoto, Tetsuya; Takagi, Toshiyuki; Hashizume, Hidetoshi

    2012-01-01

    Highlights: ► We propose a method to simulate stress corrosion cracking. ► The method offers nondestructive signals similar to those of actual cracking. ► Visual and eddy current examinations validate the method. - Abstract: This study proposes a simple and cost-effective approach to fabricate an artificial flaw that is identical to stress corrosion cracking especially from the viewpoint of electromagnetic nondestructive evaluations. The key idea of the approach is to embed a partially-bonded region inside a material by bonding together surfaces that have grooves. The region is regarded as an area of uniform non-zero conductivity from an electromagnetic nondestructive point of view, and thus simulates the characteristics of stress corrosion cracking. Since the grooves are introduced using electro-discharge machining, one can control the profile of the imitative stress corrosion cracking accurately. After numerical simulation to evaluate the spatial resolution of conventional eddy current testing, six specimens made of type 316L austenitic stainless steel were fabricated on the basis of the results of the simulations. Visual and eddy current examinations were carried out to demonstrate that the artificial flaws well simulated the characteristics of actual stress corrosion cracking. Subsequent destructive test confirmed that the bonding did not change the depth profiles of the artificial flaw.

  15. Comparison of exercise stress testing with dobutamine stress echocardiography and radionuclide ventriculography for diagnosis of coronary artery disease

    International Nuclear Information System (INIS)

    Ozdemir, K.; Kisacik, H.L.; Oguzhan, A.

    1999-01-01

    Dobutamine stress echocardiography, Tc-99m radionuclide ventriculography (RNVG), and exercise stress testing were performed prospectively in 63 patients with suspected coronary artery disease to compare the values of exercise testing, dobutamine stress echocardiography and RNVG in the non-invasive diagnosis of coronary artery disease. The sensitivities of dobutamine stress echocardiography and RNVG were found to be higher than that of exercise testing (93-62%, p 0.05). There were no differences between the sensitivities of the three techniques in multiple vessel disease (p>0.05). The specificities of dobutamine stress echocardiography and RNVG were higher than that of exercise testing (for both of the tests 86-62%, p 0.05). The results of dobutamine stress echocardiography RNVG were concordant with each other in 46 patients (76%, kappa=65%) in sectional analysis. Dobutamine stress echocardiography and RNVG tests were comparable with each other in 85% of the 189 segments (kappa=64%). The expected 5% decrease at peak doses of dobutamine was not detected in stress echocardiography in 25 patients and in RNVG in 26 of the patients. Dobutamine stress echocardiography and RNVG are superior to exercise testing in the diagnosis of single vessel disease and there is no significant difference between the two techniques. When the ejection fraction is considered in dobutamine stress echocardiography and RNVG, it does not make an additional contribution to the diagnosis of coronary artery disease. (author)

  16. Computer Breakdown as a Stress Factor during Task Completion under Time Pressure: Identifying Gender Differences Based on Skin Conductance

    Directory of Open Access Journals (Sweden)

    René Riedl

    2013-01-01

    Full Text Available In today’s society, as computers, the Internet, and mobile phones pervade almost every corner of life, the impact of Information and Communication Technologies (ICT on humans is dramatic. The use of ICT, however, may also have a negative side. Human interaction with technology may lead to notable stress perceptions, a phenomenon referred to as technostress. An investigation of the literature reveals that computer users’ gender has largely been ignored in technostress research, treating users as “gender-neutral.” To close this significant research gap, we conducted a laboratory experiment in which we investigated users’ physiological reaction to the malfunctioning of technology. Based on theories which explain that men, in contrast to women, are more sensitive to “achievement stress,” we predicted that male users would exhibit higher levels of stress than women in cases of system breakdown during the execution of a human-computer interaction task under time pressure, if compared to a breakdown situation without time pressure. Using skin conductance as a stress indicator, the hypothesis was confirmed. Thus, this study shows that user gender is crucial to better understanding the influence of stress factors such as computer malfunctions on physiological stress reactions.

  17. Accelerated Testing Methodology in Constant Stress-Rate Testing for Advanced Structural Ceramics: A Preloading Technique

    Science.gov (United States)

    Choi, Sung R.; Gyekenyesi, John P.; Huebert, Dean; Bartlett, Allen; Choi, Han-Ho

    2001-01-01

    Preloading technique was used as a means of an accelerated testing methodology in constant stress-rate (dynamic fatigue) testing for two different brittle materials. The theory developed previously for fatigue strength as a function of preload was further verified through extensive constant stress-rate testing for glass-ceramic and CRT glass in room temperature distilled water. The preloading technique was also used in this study to identify the prevailing failure mechanisms at elevated temperatures, particularly at lower test rates in which a series of mechanisms would be associated simultaneously with material failure, resulting in significant strength increase or decrease. Two different advanced ceramics including SiC whisker-reinforced composite silicon nitride and 96 wt% alumina were used at elevated temperatures. It was found that the preloading technique can be used as an additional tool to pinpoint the dominant failure mechanism that is associated with such a phenomenon of considerable strength increase or decrease.

  18. HammerCloud: A Stress Testing System for Distributed Analysis

    International Nuclear Information System (INIS)

    Ster, Daniel C van der; García, Mario Úbeda; Paladin, Massimo; Elmsheuser, Johannes

    2011-01-01

    Distributed analysis of LHC data is an I/O-intensive activity which places large demands on the internal network, storage, and local disks at remote computing facilities. Commissioning and maintaining a site to provide an efficient distributed analysis service is therefore a challenge which can be aided by tools to help evaluate a variety of infrastructure designs and configurations. HammerCloud is one such tool; it is a stress testing service which is used by central operations teams, regional coordinators, and local site admins to (a) submit arbitrary number of analysis jobs to a number of sites, (b) maintain at a steady-state a predefined number of jobs running at the sites under test, (c) produce web-based reports summarizing the efficiency and performance of the sites under test, and (d) present a web-interface for historical test results to both evaluate progress and compare sites. HammerCloud was built around the distributed analysis framework Ganga, exploiting its API for grid job management. HammerCloud has been employed by the ATLAS experiment for continuous testing of many sites worldwide, and also during large scale computing challenges such as STEP'09 and UAT'09, where the scale of the tests exceeded 10,000 concurrently running and 1,000,000 total jobs over multi-day periods. In addition, HammerCloud is being adopted by the CMS experiment; the plugin structure of HammerCloud allows the execution of CMS jobs using their official tool (CRAB).

  19. Regulation of photosynthesis and stomatal and mesophyll conductance under water stress and recovery in olive trees: correlation with gene expression of carbonic anhydrase and aquaporins.

    Science.gov (United States)

    Perez-Martin, Alfonso; Michelazzo, Chiara; Torres-Ruiz, Jose M; Flexas, Jaume; Fernández, José E; Sebastiani, Luca; Diaz-Espejo, Antonio

    2014-07-01

    The hypothesis that aquaporins and carbonic anhydrase (CA) are involved in the regulation of stomatal (g s) and mesophyll (g m) conductance to CO2 was tested in a short-term water-stress and recovery experiment in 5-year-old olive plants (Olea europaea) growing outdoors. The evolution of leaf gas exchange, chlorophyll fluorescence, and plant water status, and a quantitative analysis of photosynthesis limitations, were followed during water stress and recovery. These variables were correlated with gene expression of the aquaporins OePIP1.1 and OePIP2.1, and stromal CA. At mild stress and at the beginning of the recovery period, stomatal limitations prevailed, while the decline in g m accounted for up to 60% of photosynthesis limitations under severe water stress. However, g m was restored to control values shortly after rewatering, facilitating the recovery of the photosynthetic rate. CA was downregulated during water stress and upregulated after recovery. The use of structural equation modelling allowed us to conclude that both OePIP1.1 and OePIP2.1 expression could explain most of the variations observed for g s and g m. CA expression also had a small but significant effect on g m in olive under water-stress conditions. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  20. Proposed Testing to Assess the Accuracy of Glass-To-Metal Seal Stress Analyses.

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, Robert S.; Emery, John M; Tandon, Rajan; Antoun, Bonnie R.; Stavig, Mark E.; Newton, Clay S.; Gibson, Cory S; Bencoe, Denise N.

    2014-09-01

    The material characterization tests conducted on 304L VAR stainless steel and Schott 8061 glass have provided higher fidelity data for calibration of material models used in Glass - T o - Metal (GTM) seal analyses. Specifically, a Thermo - Multi - Linear Elastic Plastic ( thermo - MLEP) material model has be en defined for S S304L and the Simplified Potential Energy Clock nonlinear visc oelastic model has been calibrated for the S8061 glass. To assess the accuracy of finite element stress analyses of GTM seals, a suite of tests are proposed to provide data for comparison to mo del predictions.

  1. Sweat conductivity and coulometric quantitative test in neonatal cystic fibrosis screening.

    Science.gov (United States)

    Domingos, Mouseline Torquato; Magdalena, Neiva Isabel Rodrigues; Cat, Mônica Nunes Lima; Watanabe, Alexandra Mitiru; Rosário Filho, Nelson Augusto

    2015-01-01

    To compare the results obtained with the sweat test using the conductivity method and coulometric measurement of sweat chloride in newborns (NBs) with suspected cystic fibrosis (CF) in the neonatal screening program. The sweat test was performed simultaneously by both methods in children with and without CF. The cutoff values to confirm CF were >50 mmol/L in the conductivity and >60 mmol/L in the coulometric test. There were 444 infants without CF (185 males, 234 females, and 24 unreported) submitted to the sweat test through conductivity and coulometric measurement simultaneously, obtaining median results of 32 mmol/L and 12 mmol/L, respectively. For 90 infants with CF, the median values of conductivity and coulometric measurement were 108 mmol/L and 97 mmol/L, respectively. The false positive rate for conductivity was 16.7%, and was higher than 50 mmol/L in all patients with CF, which gives this method a sensitivity of 100% (95% CI: 93.8-97.8), specificity of 96.2% (95% CI: 93.8-97.8), positive predictive value of 83.3% (95% CI: 74.4-91.1), negative predictive value of 100% (95% CI: 90.5-109.4), and 9.8% accuracy. The correlation between the methods was r=0.97 (p>0.001). The best suggested cutoff value was 69.0 mmol/L, with a kappa coefficient=0.89. The conductivity test showed excellent correlation with the quantitative coulometric test, high sensitivity and specificity, and can be used in the diagnosis of CF in children detected through newborn screening. Copyright © 2015 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  2. Feasibility and normal values of an integrated conductivity (Nanoduct™) sweat test system in healthy newborns.

    Science.gov (United States)

    Kuehni, Claudia E; Schindler, Matthias; Mazur, Agnieszka; Malzacher, Andreas; Hornung, René; Barben, Juerg

    2017-07-01

    Nanoduct™ is a simple and practical sweat analysis system measuring conductivity in situ. It requires only three microlitres of sweat, making it especially applicable to newborns. We measured conductivity in 260 healthy term infants at the age of four days, and again at four weeks to determine the proportion of successful tests, test duration, and normal values for sweat conductivity in newborns. Sufficient sweat was collected in 159/260 of four-day olds (61%), and in 225/239 of four-week olds (94%). Mean (sd) test duration was 27 (5) and 25 (5) min. Mean (sd, range) conductivity was 53mmol/l (16, 8-114) at age four days, and 36 (9, 12-64) at four weeks. Determination of sweat conductivity using Nanoduct™ cannot be recommended for four-day old newborns. However, at the age of four weeks the success rate is high (94%), and conductivity values at that age are comparable to older healthy children. Copyright © 2017 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.

  3. Technical and management considerations in conducting type B shipping container tests

    International Nuclear Information System (INIS)

    Whitney, M.A.; Leader, D.R.; Phipps, D.P.

    1994-01-01

    The Code of Federal Regulations (CFR) mandate that type B shipping containers are capable of surviving specific drop tests. One approach for demonstrating compliance to the CFRs is to drop test a shipping container. This paper will discuss the technical and management considerations in conducting such drop tests on the 9975 family of shipping containers. For both technical and management considerations this paper will comment on loading the shipping container, dropping the shopping container, and examination of the shipping container after the drop tests

  4. Color Shift Modeling of Light-Emitting Diode Lamps in Step-Loaded Stress Testing

    OpenAIRE

    Cai, Miao; Yang, Daoguo; Huang, J.; Zhang, Maofen; Chen, Xianping; Liang, Caihang; Koh, S.W.; Zhang, G.Q.

    2017-01-01

    The color coordinate shift of light-emitting diode (LED) lamps is investigated by running three stress-loaded testing methods, namely step-up stress accelerated degradation testing, step-down stress accelerated degradation testing, and constant stress accelerated degradation testing. A power model is proposed as the statistical model of the color shift (CS) process of LED products. Consequently, a CS mechanism constant is obtained for detecting the consistency of CS mechanisms among various s...

  5. Characteristics of Anisotropic Conducting Polymers Suggest Feasibility of Test Fixtures up to 110 GHz

    Directory of Open Access Journals (Sweden)

    Mark Sippel

    2017-12-01

    Full Text Available Applications and volume of integrated circuits operating at frequencies up to 100 GHz are steadily increasing. This establishes serious challenges, especially for temporarily contacting such products during manufacturing tests with appropriate signal integrity. At present, existing test socket concepts have reached their applicability limit. The most promising candidates to meet the requirements of future microwave device interfacing are thin, anisotropic conducting polymers. This paper reports a survey covering measurement methodology for signal integrity properties of conducting polymers, model parameter extraction, measurement results from various materials, reliability issues, and a prototype application.

  6. Testing the tenets of minority stress theory in workplace contexts.

    Science.gov (United States)

    Velez, Brandon L; Moradi, Bonnie; Brewster, Melanie E

    2013-10-01

    The links of minority stressors (workplace discrimination, expectations of stigma, internalized heterosexism, and identity management strategies) with psychological distress and job satisfaction were examined in a sample of 326 sexual minority employees. Drawing from minority stress theory and the literature on the vocational experiences of sexual minority people, patterns of mediation and moderation were tested. Minority stressors were associated with greater distress and lower job satisfaction. A mediation model was supported in which the links of discrimination and internalized heterosexism with psychological distress were mediated by a concealment-focused identity management strategy (i.e., avoiding), and the links of discrimination, expectations of stigma, and internalized heterosexism with job satisfaction were mediated by a disclosure-focused identity management strategy (i.e., integrating). Tests of moderation indicated that for sexual minority women (but not men), the positive association of discrimination with distress was stronger at higher levels of internalized heterosexism than at lower levels. In addition, lower levels of internalized heterosexism and concealment strategies (i.e., counterfeiting and avoiding) and higher levels of a disclosure strategy (i.e., integrating) were associated with higher job satisfaction in the context of low discrimination, but this buffering effect disappeared as level of discrimination increased. The implications of these findings for minority stress research are discussed, and clinical recommendations are made.

  7. DECOVALEX I - Test Case 1: Coupled stress-flow model

    International Nuclear Information System (INIS)

    Rosengren, L.; Christianson, M.

    1995-12-01

    This report presents the results of the coupled stress-flow model, test case 1 of Decovalex. The model simulates the fourth loading cycle of a coupled stress-flow test and subsequent shearing up to and beyond peak shear resistance. The first loading sequence (A) consists of seven normal loading steps: 0, 5, 15, 25, 15, 5, 0 MPa. The second loading sequence (B) consists of the following eight steps: unstressed state, normal boundary loading of 25 MPa (no shearing), and then shearing of 0.5, 0.8, 2, 4, 2, 0 mm. Two different options regarding the rock joint behaviour were modeled in accordance with the problem definition. In option 1 a linear elastic joint model with Coulomb slip criterion was used. In option 2 a non-linear empirical (i.e. Barton-Bandis) joint model was used. The hydraulic condition during both load sequence A and B was a constant head of 5 m at the inlet point and 0 m at the outlet point. All model runs presented in this report were performed using the two-dimensional distinct element computer code UDEC, version 1.8. 30 refs, 36 figs

  8. Testing the adaptation to poverty-related stress model: predicting psychopathology symptoms in families facing economic hardship.

    Science.gov (United States)

    Wadsworth, Martha E; Raviv, Tali; Santiago, Catherine Decarlo; Etter, Erica M

    2011-01-01

    This study tested the Adaptation to Poverty-related Stress Model and its proposed relations between poverty-related stress, effortful and involuntary stress responses, and symptoms of psychopathology in an ethnically diverse sample of low-income children and their parents. Prospective Hierarchical Linear Modeling analyses conducted with 98 families (300 family members: 136 adults, 82 adolescents and preadolescents, 82 school-age children) revealed that, consistent with the model, primary and secondary control coping were protective against poverty-related stress primarily for internalizing symptoms. Conversely, disengagement coping exacerbated externalizing symptoms over time. In addition, involuntary engagement stress responses exacerbated the effects of poverty-related stress for internalizing symptoms, whereas involuntary disengagement responses exacerbated externalizing symptoms. Age and gender effects were found in most models, reflecting more symptoms of both types for parents than children and higher levels of internalizing symptoms for girls.

  9. Microscopic creep models and the interpretation of stress-dip tests during creep

    International Nuclear Information System (INIS)

    Poirier, J.P.

    1976-09-01

    A critical analysis is made of the principal divergent view points concerning stress-dip tests. The raw data are examined and interpreted in the light of various creep models. The following problems are discussed: is the reverse strain anelastic or plastic; is the zero creep rate periodic due to recovery or is it spurious; can the existence or inexistence of an internal stress be deduced from stress-dip tests; can stress-dip tests allow to determine whether glide is jerky or viscous; can the internal stress be measured by stress-dip tests

  10. Review of FRAP-T4 performance based on fuel behavior tests conducted in the PBF

    International Nuclear Information System (INIS)

    Charyulu, M.K.

    1979-09-01

    The ability of the Fuel Rod Analysis Program - Transient (FRAP-T), a computer code developed at the Idaho National Engineering Laboratory to calculate fuel rod behavior during transient experiments conducted in the Power Burst Facility, is discussed. Fuel rod behavior calculations are compared with data from tests performed under postulated RIA, LOCA, and PCM accident conditions. Physical phenomena, rod damage, and damage mechanisms observed during the tests and not presently incorporated into the FRAP-T code are identified

  11. Photosynthetic response of an alpine plant, Rhododendron delavayi Franch, to water stress and recovery: the role of mesophyll conductance

    Directory of Open Access Journals (Sweden)

    Yanfei eCai

    2015-12-01

    Full Text Available Rhododendron delavayi Franch is an evergreen shrub or small tree with large scarlet flowers that makes it highly attractive as an ornamental species. The species is native to southwest China and southeast Asia, especially the Himalayan region, showing good adaptability and tolerance to drought. To understand the water stress coping mechanisms of R. delavayi, we analysed the plant’s photosynthetic performance during water stress and recovery. In particular, we looked at the regulation of stomatal (gs and mesophyll conductance (gm, and maximum rate of carboxylation (Vcmax. After four days of water stress treatment, the net CO2 assimilation rate (AN declined slightly while gs and gm were not affected and stomatal limitation (SL was therefore negligible. At this stage mesophyll conductance limitation (MCL and biochemical limitation (BL constituted the main limitation factors. After eight days of water stress treatment, AN, gs and gm had decreased notably. At this stage SL increased markedly and MCL even more so, while BL remained relatively constant. After re-watering, the recovery of AN, gs and gm was rapid, although remaining below the levels of the control plants, while Vcmax fully regained control levels after three days of re-watering. MCL remained the main limitation factor irrespective of the degree of photosynthetic recovery. In conclusion, in our experiment MCL was the main photosynthetic limitation factor of R. delavayi under water stress and during the recovery phase, with the regulation of gm probably being the result of interactions between the environment and leaf anatomical features.

  12. Standard Guide for Conducting Supplemental Surveillance Tests for Nuclear Power Reactor Vessels, E 706 (IH)

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This guide discusses test procedures that can be used in conjunction with, but not as alternatives to, those required by Practices E185 and E2215 for the surveillance of nuclear reactor vessels. The supplemental mechanical property tests outlined permit the acquisition of additional information on radiation-induced changes in fracture toughness, notch ductility, and yield strength properties of the reactor vessel steels. 1.2 This guide provides recommendations for the preparation of test specimens for irradiation, and identifies special precautions and requirements for reactor surveillance operations and postirradiation test planning. Guidance on data reduction and computational procedures is also given. Reference is made to other ASTM test methods for the physical conduct of specimen tests and for raw data acquisition.

  13. Design, fabrication and testing of a prototype stressed-shell fuel isolation container

    International Nuclear Information System (INIS)

    Crosthwaite, J.L.; Barrie, J.N.; Nuttall, K.

    1982-07-01

    Atomic Energy of Canada Limited is conducting and coordinating research into the development of engineered barriers for the disposal of unreprocessed irradiated fuel within a deep, stable geologic vault. In one approach, a containment shell of corrosion-resistant metal is proposed as the principal barrier to radionuclide release, giving a high probability of containment for at least 300 years, thus ensuring isolation of nearly all fission products for their hazardous lives. The simplest concept is the 'stressed-shell' container, designed with sufficient shell thickness to withstand the hydrostatic pressure within a 1000-m deep disposal vault postulated to have flooded with groundwater. This report describes the design, fabrication, analysis and hydrostatic testing of a full-scale stressed-shell prototype. The report concludes that the deformation and collapse performance of stressed-shell designs, based on short-term mechanical properties be modelled adequately by BOSOR 5, a commercially available stress-strain computer program. If the stressed-shell concept is retained as a viable fuel isolation concept, future analyses should include an assessment of the role of material creep on long-term container performance

  14. Evaluation of the radionuclide tracer test conducted at the project Gnome Underground Nuclear Test Site, New Mexico

    International Nuclear Information System (INIS)

    Pohll, G.; Pohlmann, K.

    1996-08-01

    A radionuclide tracer test was conducted in 1963 by the U.S. Geological Survey at the Project Gnome underground nuclear test site, approximately 40 km southeast of Carlsbad, New Mexico. The tracer study was carried out under the auspices of the U.S. Atomic Energy Commission (AEC) to study the transport behavior of radionuclides in fractured rock aquifers. The Culebra Dolomite was chosen for the test because it was considered to be a reasonable analogue of the fractured carbonate aquifer at the Nevada Test Site (NTS), the principal location of U.S. underground nuclear tests. Project Gnome was one of a small number of underground nuclear tests conducted by the AEC at sites distant from the NTS. The Gnome device was detonated on December 10, 1961 in an evaporate unit at a depth of 360 m below ground surface. Recently, the U.S. Department of Energy (DOE) implemented an environmental restoration program to characterize, remediate, and close these offsite nuclear test areas. An early step in this process is performance of a preliminary risk analysis of the hazard posed by each site. The Desert Research Institute has performed preliminary hydrologic risk evaluations for the groundwater transport pathway at Gnome. That evaluation included the radioactive tracer test as a possible source because the test introduced radionuclides directly into the Culebra Dolomite, which is the only aquifer at the site. This report presents a preliminary evaluation of the radionuclide tracer test as a source for radionuclide migration in the Culebra Dolomite. The results of this study will assist in planning site characterization activities and refining estimates of the radionuclide source for comprehensive models of groundwater transport st the Gnome site

  15. Improved Accelerated Stress Tests Based on Fuel Cell Vehicle Data

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Timothy [Research Engineer; Motupally, Sathya [Research Engineer

    2012-06-01

    UTC will led a top-tier team of industry and national laboratory participants to update and improve DOE’s Accelerated Stress Tests (AST’s) for hydrogen fuel cells. This in-depth investigation will focused on critical fuel cell components (e.g. membrane electrode assemblies - MEA) whose durability represented barriers for widespread commercialization of hydrogen fuel cell technology. UTC had access to MEA materials that had accrued significant load time under real-world conditions in PureMotion® 120 power plant used in transit buses. These materials are referred to as end-of-life (EOL) components in the rest of this document. Advanced characterization techniques were used to evaluate degradation mode progress using these critical cell components extracted from both bus power plants and corresponding materials tested using the DOE AST’s. These techniques were applied to samples at beginning-of-life (BOL) to serve as a baseline. These comparisons advised the progress of the various failure modes that these critical components were subjected to, such as membrane degradation, catalyst support corrosion, platinum group metal dissolution, and others. Gaps in the existing ASTs predicted the degradation observed in the field in terms of these modes were outlined. Using the gaps, new AST’s were recommended and tested to better reflect the degradation modes seen in field operation. Also, BOL components were degraded in a test vehicle at UTC designed to accelerate the bus field operation.

  16. HammerCloud: A Stress Testing System for Distributed Analysis

    CERN Document Server

    van der Ster, Daniel C; Ubeda Garcia, Mario; Paladin, Massimo

    2011-01-01

    Distributed analysis of LHC data is an I/O-intensive activity which places large demands on the internal network, storage, and local disks at remote computing facilities. Commissioning and maintaining a site to provide an efficient distributed analysis service is therefore a challenge which can be aided by tools to help evaluate a variety of infrastructure designs and configurations. HammerCloud (HC) is one such tool; it is a stress testing service which is used by central operations teams, regional coordinators, and local site admins to (a) submit arbitrary number of analysis jobs to a number of sites, (b) maintain at a steady-state a predefined number of jobs running at the sites under test, (c) produce web-based reports summarizing the efficiency and performance of the sites under test, and (d) present a web-interface for historical test results to both evaluate progress and compare sites. HC was built around the distributed analysis framework Ganga, exploiting its API for grid job management. HC has been ...

  17. Comprehensive overview of FPL field testing conducted in the tropics (1945-2005)

    Science.gov (United States)

    Grant T. Kirker; Stan L. Lebow; Mark E. Mankowski

    2016-01-01

    Tropical exposure often represents a more severe environment for treated wood and wood based products. Accelerated tropical decay rates are typically attributed to higher mean rainfall and temperatures. The Forest Products Laboratory (FPL) in Madison, WI has been conducting tropical field tests in a variety of locations since the early 1940’s. This paper summarizes FPL...

  18. Spatial variability of hydraulic conductivity of an unconfined sandy aquifer determined by a mini slug test

    DEFF Research Database (Denmark)

    Bjerg, Poul Løgstrup; Hinsby, Klaus; Christensen, Thomas Højlund

    1992-01-01

    The spatial variability of the hydraulic conductivity in a sandy aquifer has been determined by a mini slug test method. The hydraulic conductivity (K) of the aquifer has a geometric mean of 5.05 × 10−4 m s−1, and an overall variance of 1n K equal to 0.37 which corresponds quite well to the results...... obtained by two large scale tracer experiments performed in the aquifer. A geological model of the aquifer based on 31 sediment cores, proposed three hydrogeological layers in the aquifer concurrent with the vertical variations observed with respect to hydraulic conductivity. The horizontal correlation......, to be in the range of 0.3–0.5 m compared with a value of 0.42 m obtained in one of the tracer tests performed....

  19. Baking system for ports of experimental advanced super-conducting tokamak vacuum vessel and thermal stress analysis

    International Nuclear Information System (INIS)

    Cheng Yali; Bao Liman; Song Yuntao; Yao Damao

    2006-01-01

    The baking system of Experimental Advanced Super-Conducting Toakamk (EAST) vacuum vessel is necessary to obtain the baking temperature of 150 degree C. In order to define suitable alloy heaters and achieve their reasonable layouts, thermal analysis was carried out with ANSYS code. The analysis results indicate that the temperature distribution and thermal stress of most parts of EAST vacuum vessel ports are uniform, satisfied for the requirement, and are safe based on ASME criterion. Feasible idea on reducing the stress focus is also considered. (authors)

  20. Standard practice for conducting and evaluating laboratory corrosions tests in soils

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This practice covers procedures for conducting laboratory corrosion tests in soils to evaluate the corrosive attack on engineering materials. 1.2 This practice covers specimen selection and preparation, test environments, and evaluation of test results. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  1. Perceived stress and resilience in Alzheimer's disease caregivers: testing moderation and mediation models of social support.

    Science.gov (United States)

    Wilks, Scott E; Croom, Beth

    2008-05-01

    The study examined whether social support functioned as a protective, resilience factor among Alzheimer's disease (AD) caregivers. Moderation and mediation models were used to test social support amid stress and resilience. A cross-sectional analysis of self-reported data was conducted. Measures of demographics, perceived stress, family support, friend support, overall social support, and resilience were administered to caregiver attendees (N=229) of two AD caregiver conferences. Hierarchical regression analysis showed the compounded impact of predictors on resilience. Odds ratios generated probability of high resilience given high stress and social supports. Social support moderation and mediation were tested via distinct series of regression equations. Path analyses illustrated effects on the models for significant moderation and/or mediation. Stress negatively influenced and accounted for most variation in resilience. Social support positively influenced resilience, and caregivers with high family support had the highest probability of elevated resilience. Moderation was observed among all support factors. No social support fulfilled the complete mediation criteria. Evidence of social support as a protective, moderating factor yields implications for health care practitioners who deliver services to assist AD caregivers, particularly the promotion of identification and utilization of supportive familial and peer relations.

  2. The role of mesophyll conductance during water stress and recovery in tobacco (Nicotiana sylvestris): acclimation or limitation?

    Science.gov (United States)

    Galle, Alexander; Florez-Sarasa, Igor; Tomas, Magdalena; Pou, Alicia; Medrano, Hipolito; Ribas-Carbo, Miquel; Flexas, Jaume

    2009-01-01

    While the responses of photosynthesis to water stress have been widely studied, acclimation to sustained water stress and recovery after re-watering is poorly understood. In particular, the factors limiting photosynthesis under these conditions, and their possible interactions with other environmental conditions, are unknown. To assess these issues, changes of photosynthetic CO(2) assimilation (A(N)) and its underlying limitations were followed during prolonged water stress and subsequent re-watering in tobacco (Nicotiana sylvestris) plants growing under three different climatic conditions: outdoors in summer, outdoors in spring, and indoors in a growth chamber. In particular, the regulation of stomatal conductance (g(s)), mesophyll conductance to CO(2) (g(m)), leaf photochemistry (chlorophyll fluorescence), and biochemistry (V(c,max)) were assessed. Leaf gas exchange and chlorophyll fluorescence data revealed that water stress induced a similar degree of stomatal closure and decreased A(N) under all three conditions, while V(c,max) was unaffected. However, the behaviour of g(m) differed depending on the climatic conditions. In outdoor plants, g(m) strongly declined with water stress, but it recovered rapidly (1-2 d) after re-watering in spring while it remained low many days after re-watering in summer. In indoor plants, g(m) initially declined with water stress, but then recovered to control values during the acclimation period. These differences were reflected in different velocities of recovery of A(N) after re-watering, being the slowest in outdoor summer plants and the fastest in indoor plants. It is suggested that these differences among the experiments are related to the prevailing climatic conditions, i.e. to the fact that stress factors other than water stress have been superimposed (e.g. excessive light and elevated temperature). In conclusion, besides g(s), g(m) contributes greatly to the limitation of photosynthesis during water stress and during

  3. Conducting meta-analyses of HIV prevention literatures from a theory-testing perspective.

    Science.gov (United States)

    Marsh, K L; Johnson, B T; Carey, M P

    2001-09-01

    Using illustrations from HIV prevention research, the current article advocates approaching meta-analysis as a theory-testing scientific method rather than as merely a set of rules for quantitative analysis. Like other scientific methods, meta-analysis has central concerns with internal, external, and construct validity. The focus of a meta-analysis should only rarely be merely describing the effects of health promotion, but rather should be on understanding and explaining phenomena and the processes underlying them. The methodological decisions meta-analysts make in conducting reviews should be guided by a consideration of the underlying goals of the review (e.g., simply effect size estimation or, preferably theory testing). From the advocated perspective that a health behavior meta-analyst should test theory, the authors present a number of issues to be considered during the conduct of meta-analyses.

  4. A Conduction-Cooled Superconducting Magnet System-Design, Fabrication and Thermal Tests

    DEFF Research Database (Denmark)

    Song, Xiaowei (Andy); Holbøll, Joachim; Wang, Qiuliang

    2015-01-01

    A conduction-cooled superconducting magnet system with an operating current of 105.5 A was designed, fabricated and tested for material processing applications. The magnet consists of two coaxial NbTi solenoid coils with an identical vertical height of 300 mm and is installed in a high-vacuumed c......A conduction-cooled superconducting magnet system with an operating current of 105.5 A was designed, fabricated and tested for material processing applications. The magnet consists of two coaxial NbTi solenoid coils with an identical vertical height of 300 mm and is installed in a high......-vacuumed cryostat. A two-stage GM cryocooler with a cooling power of 1.5 W at 4.2 K in the second stage is used to cool the system from room temperature to 4.2 K. In this paper, the detailed design, fabrication, thermal analysis and tests of the system are presented....

  5. The benefits of conducting factory performance tests for main mine fans

    Energy Technology Data Exchange (ETDEWEB)

    Ray, R.E.Jr. [PB Americas Inc., New York, NY (United States); Gamble, G.A. [Clarage Twin City Fan Co., Akron, OH (United States)

    2010-07-01

    Axial flow fans used in underground mining are also commonly used in subway tunnel ventilation fans to provide an evacuation path during a tunnel fire emergency. The axial flow fans provide sufficient air velocity to the fire site to prevent backlayering of smoke against the incoming airflow. Since the tunnels are used by the public, advance testing of fans and motors is conducted to confirm that the equipment will perform as specified during a fire. This paper discussed some of the advantages derived from conducting fan factory tests for tunnel projects that would also apply to mining applications. It also described other benefits from testing that are unique to mining. External factors that may cause the fan performance to vary considerably from the predicted performance measured at the factory were also discussed. These included air density changes and system effects produced by poorly designed shaft configurations and fan inlet ductwork. 11 refs., 6 figs.

  6. Teacher Participation in Stress Management through Different Theoretical Lenses: A Study Conducted in the Mahikeng Area

    Science.gov (United States)

    Pelser, A. M. F.; van Wyk, C.

    2016-01-01

    The purpose of the research reported in this article was to place the known facts of the topic of teacher participation in stress management in the context of management and leadership in education. The emphasis in the conceptual and theoretical framework was on showing points of connection between leadership and management on the one hand and…

  7. Using Pneumatics to Perform Laboratory Hydraulic Conductivity Tests on Gravel with Underdamped Responses

    Science.gov (United States)

    Judge, A. I.

    2011-12-01

    A permeameter has been designed and built to perform laboratory hydraulic conductivity tests on various kinds of gravel samples with hydraulic conductivity values ranging from 0.1 to 1 m/s. The tests are commenced by applying 200 Pa of pneumatic pressure to the free surface of the water column in a riser connected above a cylinder that holds large gravel specimens. This setup forms a permeameter specially designed for these tests which is placed in a barrel filled with water, which acts as a reservoir. The applied pressure depresses the free surface in the riser 2 cm until it is instantly released by opening a ball valve. The water then flows through the base of the cylinder and the specimen like a falling head test, but the water level oscillates about the static value. The water pressure and the applied air pressure in the riser are measured with vented pressure transducers at 100 Hz. The change in diameter lowers the damping frequency of the fluctuations of the water level in the riser, which allows for underdamped responses to be observed for all tests. The results of tests without this diameter change would otherwise be a series of critically damped responses with only one or two oscillations that dampen within seconds and cannot be evaluated with equations for the falling head test. The underdamped responses oscillate about the static value at about 1 Hz and are very sensitive to the hydraulic conductivity of all the soils tested. These fluctuations are also very sensitive to the inertia and friction in the permeameter that are calculated considering the geometry of the permeameter and verified experimentally. Several gravel specimens of various shapes and sizes are tested that show distinct differences in water level fluctuations. The friction of the system is determined by calibrating the model with the results of tests performed where the cylinder had no soil in it. The calculation of the inertia in the response of the water column for the typical testing

  8. Stress Tests Worldwide - IAEA Nuclear Safety Action Plan

    International Nuclear Information System (INIS)

    Lyons, J.E.

    2012-01-01

    The IAEA nuclear safety action plan relies on 11 important issues. 1) Safety assessments in light of the Fukushima accident: the IAEA secretariat will develop a methodology for stress tests against specific extreme natural hazards and will provide assistance for their implementation; 2) Strengthen existing IAEA peer reviews; 3) Emergency preparedness and response; 4) National Regulatory bodies in terms of independence and adequacy of human and financial resources; 5) The development of safety culture and scientific and technical capacity in Operating Organizations; 6) The upgrading of IAEA safety standards in a more efficient way; 7) A better implementation of relevant conventions concerning nuclear safety and nuclear accidents; 8) To provide a broad assistance on safety standard for countries embarking on a nuclear power program; 9) To facilitate the use of available information, expertise and techniques concerning radiation protection; 10) To enhance the transparency of nuclear industry; and 11) To promote the cooperation between member states in nuclear safety. (A.C.)

  9. Synthesis and testing of a conducting polymeric composite material for lightning strike protection applications

    Science.gov (United States)

    Katunin, A.; Krukiewicz, K.; Turczyn, R.; Sul, P.; Łasica, A.; Catalanotti, G.; Bilewicz, M.

    2017-02-01

    Lightning strike protection is one of the important issues in the modern maintenance problems of aircraft. This is due to a fact that the most of exterior elements of modern aircraft is manufactured from polymeric composites which are characterized by isolating electrical properties, and thus cannot carry the giant electrical charge when the lightning strikes. This causes serious damage of an aircraft structure and necessity of repairs and tests before returning a vehicle to operation. In order to overcome this problem, usually metallic meshes are immersed in the polymeric elements. This approach is quite effective, but increases a mass of an aircraft and significantly complicates the manufacturing process. The approach proposed by the authors is based on a mixture of conducting and dielectric polymers. Numerous modeling studies which are based on percolation clustering using kinetic Monte Carlo methods, finite element modeling of electrical and mechanical properties, and preliminary experimental studies, allow achieving an optimal content of conducting particles in a dielectric matrix in order to achieve possibly the best electrical conductivity and mechanical properties, simultaneously. After manufacturing the samples with optimal content of a conducting polymer, mechanical and electrical characterization as well as high-voltage testing was performed. The application of such a material simplifies manufacturing process and ensures unique properties of aircraft structures, which allows for minimizing damage after lightning strike, as well as provide electrical bounding and grounding, interference shielding, etc. The proposed solution can minimize costs of repair, testing and certification of aircraft structures damaged by lightning strikes.

  10. Wave Pattern Peculiarities of Different Types of Explosions Conducted at Semipalatinsk Test Site

    Science.gov (United States)

    Sokolova, Inna

    2014-05-01

    The historical seismograms of the explosions conducted at the STS in 1949 - 1989 are of great interest for the researchers in the field of monitoring. Large number of air (86), surface (30) and underground nuclear explosions were conducted here in boreholes and tunnels (340). In addition to nuclear explosions, large chemical explosions were conducted at the Test Site. It is known that tectonic earthquakes occur on the Test Site territory and near it. Since 2005 the Institute of Geophysical Researches conducts works on digitizing the historical seismograms of nuclear explosions. Currently, the database contains more than 6000 digitized seismograms of nuclear explosions used for investigative monitoring tasks, major part of them (4000) are events from the STS region. Dynamic parameters of records of air, surface and underground nuclear explosions, as well as large chemical explosions with compact charge laying were investigated for seismic stations located on the territory of Kazakhstan using digitized records of the STS events. In addition, the comparison between salvo wave pattern and single explosions was conducted. The records of permanent and temporary seismic stations (epicentral distances range 100 - 800 km) were used for the investigations. Explosions spectra were analyzed, specific features of each class of events were found. The seismograms analysis shows that the wave pattern depends significantly on the explosion site and on the source type.

  11. Development and Testing of a Variable Conductance Thermal Acquisition, Transport, and Switching System

    Science.gov (United States)

    Bugby, David C.; Farmer, Jeffery T.; Stouffer, Charles J.

    2013-01-01

    This paper describes the development and testing of a scalable thermal management architecture for instruments, subsystems, or systems that must operate in severe space environments with wide variations in sink temperature. The architecture involves a serial linkage of one or more hot-side variable conductance heat pipes (VCHPs) to one or more cold-side loop heat pipes (LHPs). The VCHPs provide wide area heat acquisition, limited distance thermal transport, modest against gravity pumping, concentrated LHP startup heating, and high switching ratio variable conductance operation. The LHPs provide localized heat acquisition, long distance thermal transport, significant against gravity pumping, and high switching ratio variable conductance operation. The single-VCHP, single-LHP system described herein was developed to maintain thermal control of a small robotic lunar lander throughout the lunar day-night thermal cycle. It is also applicable to other variable heat rejection space missions in severe environments. Operationally, despite a 60-70% gas blocked VCHP condenser during ON testing, the system was still able to provide 2-4 W/K ON conductance, 0.01 W/K OFF conductance, and an end-to-end switching ratio of 200-400. The paper provides a detailed analysis of VCHP condenser performance, which quantified the gas blockage situation. Future multi-VCHP/multi-LHP thermal management system concepts that provide power/transport length scalability are also discussed.

  12. Stochastic joint inversion of hydrogeophysical data for salt tracer test monitoring and hydraulic conductivity imaging

    Science.gov (United States)

    Jardani, A.; Revil, A.; Dupont, J. P.

    2013-02-01

    The assessment of hydraulic conductivity of heterogeneous aquifers is a difficult task using traditional hydrogeological methods (e.g., steady state or transient pumping tests) due to their low spatial resolution. Geophysical measurements performed at the ground surface and in boreholes provide additional information for increasing the resolution and accuracy of the inverted hydraulic conductivity field. We used a stochastic joint inversion of Direct Current (DC) resistivity and self-potential (SP) data plus in situ measurement of the salinity in a downstream well during a synthetic salt tracer experiment to reconstruct the hydraulic conductivity field between two wells. The pilot point parameterization was used to avoid over-parameterization of the inverse problem. Bounds on the model parameters were used to promote a consistent Markov chain Monte Carlo sampling of the model parameters. To evaluate the effectiveness of the joint inversion process, we compared eight cases in which the geophysical data are coupled or not to the in situ sampling of the salinity to map the hydraulic conductivity. We first tested the effectiveness of the inversion of each type of data alone (concentration sampling, self-potential, and DC resistivity), and then we combined the data two by two. We finally combined all the data together to show the value of each type of geophysical data in the joint inversion process because of their different sensitivity map. We also investigated a case in which the data were contaminated with noise and the variogram unknown and inverted stochastically. The results of the inversion revealed that incorporating the self-potential data improves the estimate of hydraulic conductivity field especially when the self-potential data were combined to the salt concentration measurement in the second well or to the time-lapse cross-well electrical resistivity data. Various tests were also performed to quantify the uncertainty in the inverted hydraulic conductivity

  13. Compact X-ray source at STF (Super Conducting Accelerator Test Facility)

    International Nuclear Information System (INIS)

    Urakawa, J

    2012-01-01

    KEK-STF is a super conducting linear accelerator test facility for developing accelerator technologies for the ILC (International Linear Collider). We are supported in developing advanced accelerator technologies using STF by Japanese Ministry (MEXT) for Compact high brightness X-ray source development. Since we are required to demonstrate the generation of high brightness X-ray based on inverse Compton scattering using super conducting linear accelerator and laser storage cavity technologies by October of next year (2012), the design has been fixed and the installation of accelerator components is under way. The necessary technology developments and the planned experiment are explained.

  14. Detecting the differences in responses of stomatal conductance to moisture stresses between deciduous shrubs and Artemisia subshrubs.

    Science.gov (United States)

    Gao, Qiong; Yu, Mei; Zhou, Chan

    2013-01-01

    Shrubs and subshrubs can tolerate wider ranges of moisture stresses in both soil and air than other plant life forms, and thus represent greater nonlinearity and uncertainty in ecosystem physiology. The objectives of this paper are to model shrub/subshrub stomatal conductance by synthesizing the field leaf gas exchanges data of 24 species in China, in order to detect the differences between deciduous shrubs and Artemisia subshrubs in their responses of stomatal conductance to changes in the moisture stresses. We revised a model of stomatal conductance by incorporating the tradeoff between xylem hydraulic efficiency and cavitation loss risk. We then fit the model at the three hierarchical levels: global (pooling all data as a single group), three functional groups (deciduous non-legume shrubs, deciduous legume shrubs, and subshrubs in Artemisia genus), and individual observations (species × sites). Bayesian inference with Markov Chain Monte Carlo method was applied to obtain the model parameters at the three levels. We found that the model at the level of functional groups is a significant improvement over that at the global level, indicating the significant differences in the stomatal behavior among the three functional groups. The differences in tolerance and sensitivities to changes in moisture stresses are the most evident between the shrubs and the subshrubs: The two shrub groups can tolerate much higher soil water stress than the subshrubs. The analysis at the observation level is also a significant improvement over that at the functional group level, indicating great variations within each group. Our analysis offered a clue for the equivocal issue of shrub encroachment into grasslands: While the invasion by the shrubs may be irreversible, the dominance of subshrubs, due to their lower resistance and tolerance to moisture stresses, may be put down by appropriate grassland management.

  15. The role of anxiety in cortisol stress response and cortisol recovery in boys with oppositional defiant disorder/conduct disorder.

    Science.gov (United States)

    Schoorl, Jantiene; Rijn, Sophie van; Wied, Minet de; van Goozen, Stephanie; Swaab, Hanna

    2016-11-01

    Children with antisocial and aggressive behaviors have been found to show abnormal neurobiological responses to stress, specifically impaired cortisol stress reactivity. The role of individual characteristics, such as comorbid anxiety, in the stress response is far less studied. Furthermore, this study extended previous studies in that not only baseline and reactivity to a psychosocial stressor were examined, but also recovery from a stressor. These three phases of cortisol could be impacted differentially in boys with oppositional defiant disorder/conduct disorder (ODD/CD) with (+ANX) and without anxiety (-ANX). The results revealed that cortisol patterns in response to psychosocial stress were different for boys with ODD/CD+ANX (n=32), ODD/CD-ANX (n=22) and non-clinical controls (NC) (n=34), with age range of 7.8-12.9 years. The ODD/CD-ANX group showed lower overall cortisol levels than the NC group. When considering the three phases of cortisol separately, the ODD/CD-ANX group had lower baseline cortisol levels relative to the other groups, whereas the ODD/CD+ANX showed an impaired cortisol recovery response. Within those with ODD/CD, callous-unemotional traits were predictive of high baseline cortisol levels. Also, anxiety predicted high baseline and recovery cortisol levels, whereas a high number of CD symptoms predicted reduced cortisol stress reactivity. These results clearly indicate that comorbid anxiety is an important factor in explaining differences in stress response profiles in boys with ODD/CD; although boys with CD/ODD are generally characterized by an impaired cortisol stress response, we found that those with comorbid anxiety showed impaired cortisol recovery, whereas those without anxiety showed reduced baseline cortisol levels. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Analysis of aquifer tests conducted in borehole USW G-2, 1996, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    O'Brien, G.M.

    1998-01-01

    Borehole USW G-2 is located north of Yucca Mountain in a large-hydraulic-gradient area. Two single-borehole aquifer tests were conducted in the borehole during 1996. A 54.9-hour pumping period was conducted February 6--8, 1996, and a 408-hour pumping period was conducted April 8--25, 1996. The purpose of testing was to obtain estimates of the aquifer-system transmissivity and to determine if perched water was affecting the observed water level in borehole USW G-2. This report presents and analyzes data collected between February 6 and December 17, 1996. Analysis of the aquifer-test data indicated that fracture flow, dual-porosity flow, and boundary-affected flow conditions were observed in the drawdown and recovery data. Transmissivity estimates ranged from 2.3 to 12 meters squared per day. The most representative transmissivity estimate for the interval tested is the early-time mean transmissivity of 9.4 meters squared per day. The Calico Hills Formation was the primary formation tested, but the top 3 meters of the nonpumping water column was within the overlying Topopah Spring Tuff. Persistent residual drawdown following pumping more than 6 million liters of water during aquifer testing may indicate that the bore-hole intersected a perched water body. After 236 days of recovery, residual drawdown was 0.5 meter. The quantitative effect of the perched water on the observed water level in borehole USW G-2, however, cannot be determined with the available data

  17. Effects of Xueshuantong combined with antioxidant drugs on nerve conduction function and oxidative stress in patients with diabetic peripheral neuropathy

    Directory of Open Access Journals (Sweden)

    Yuan-Zhen Chu

    2017-07-01

    Full Text Available Objective: To study the effect of Xueshuantong combined with antioxidant drugs on nerve conduction function and oxidative stress in patients with diabetic peripheral neuropathy. Methods: 138 cases of patients with diabetic peripheral neuropathy who were treated in endocrinology department of our hospital between June 2014 and October 2016 were enrolled and randomly divided into two groups. The combination group received Xueshuantong combined with antioxidant drug therapy, and the control group received antioxidant drug therapy. Before and after treatment, the nerve conduction velocity as well as serum content of oxidative stress indexes and nerve cytokines was measured. Results: 4 weeks and 8 weeks after treatment, common peroneal nerve and median nerve MNCV and SNCV as well as serum SOD, GSH-Px, HO-1, CAT, CNTF, BDNF and SDF-1α levels of both groups were significantly higher than those before treatment while serum MDA, AOPP and 8-OHdG levels were significantly lower than those before treatment, and common peroneal nerve and median nerve MNCV and SNCV as well as serum SOD, GSH-Px, HO-1, CAT, CNTF, BDNF and SDF-1α levels of combination group were significantly higher than those of control group while serum MDA, AOPP and 8-OHdG levels were significantly lower than those of control group. Conclusion: Xueshuantong combined with antioxidant drugs can improve the nerve conduction function, inhibit oxidative stress response and improve neurotrophy status in patients with diabetic peripheral neuropathy.

  18. Electrical conductivity testing of corn seeds as influenced by temperature and period of storage

    OpenAIRE

    Fessel,Simone Aparecida; Vieira,Roberval Daiton; Cruz,Mara Cristina Pessoa da; Paula,Rinaldo Cesar de; Panobianco,Maristela

    2006-01-01

    The objective of this work was to evaluate the effects of temperature (10, 20, 30, 20/10 and 30/10ºC) and period of storage on electrical conductivity (EC) in four seed lots of corn (Zea mays L.), as well as the mineral composition of the soaking solution. EC test determines indirectly the integrity of seed membrane systems, and is used for the assessment of seed vigor, because this test detects the seed deterioration process since its early phase. The research comprised determinations o...

  19. Requirements Relating To Manufacturing Constructions In The Aspect Of Conducting Ultrasonic Testing

    Directory of Open Access Journals (Sweden)

    Kaczmarek R.

    2015-09-01

    Full Text Available Basic factors which have an influence on conducting manual ultrasonic testing of joints in the welded constructions are presented in the following article. These factors are specified on the base of the guidelines referring to conditions and methods of carrying out examinations which are currently in force in the following standards PN-EN ISO 17640 and PN-EN ISO 22825. Due to the vastness of subject of ultrasonic testing the main aim of the following article is to collect all important information which relates to design and manufacture of constructions and has a key influence on the following examinations.

  20. A new thermal conductivity probe for high temperature tests for the characterization of molten salts

    Science.gov (United States)

    Bovesecchi, G.; Coppa, P.; Pistacchio, S.

    2018-05-01

    A new thermal conductivity probe for high temperature (HT-TCP) has been built and tested. Its design and construction procedure are adapted from the ambient temperature thermal conductivity probe (AT-TCP) due to good performance of the latter device. The construction procedure and the preliminary tests are accurately described. The probe contains a Pt wire as a heater and a type K thermocouple (TC) as a temperature sensor, and its size is so small (0.6 mm in diameter and 60 mm in length) as to guarantee a length to diameter ratio of about 100. Calibration tests with glycerol for temperatures between 0 °C and 60 °C have shown good agreement with literature data, within 3%. Preliminary tests were also carried on a ternary molten salt for Concentrated Solar Power (CSP) (18% in mass of NaNO3, 52% KNO3, and 30% LiNO3) at 120 °C and 150 °C. Obtained results are within λ range of the Hitec® salt (53% KNO3, 7% NaNO3, 40% NaNO2). Unfortunately, at the higher temperature tested (200 °C), the viscosity of the salt highly decreases, and free convection starts, making the measurements unreliable.

  1. Individual electrical conductivity test for the assessment of soybean seed germination.

    OpenAIRE

    MATTIONI, N. M.; MERTZ, L. M.; BARBIERI, A. P. P.; HAESBAERT, F. M.; GIORDANI, W.; LOPES, S. J.

    2015-01-01

    Soybean seed quality is affected by many factors, which may occur during the production, processing, and storage phases. To ensure the quality of seeds, the adoption of fast and efficient methods to estimate seed viability in quality control programs is important. This study aimed to determine a partition point of the individual electrical conductivity test to predict soybean seed germination. Three lots each of five different soybean cultivars (Fundacep 57 RR, BMX Potência RR, BMX Força RR, ...

  2. Methods and Models of Market Risk Stress-Testing of the Portfolio of Financial Instruments

    Directory of Open Access Journals (Sweden)

    Alexander M. Karminsky

    2015-01-01

    Full Text Available Amid instability of financial markets and macroeconomic situation the necessity of improving bank risk-management instrument arises. New economic reality defines the need for searching for more advanced approaches of estimating banks vulnerability to exceptional, but plausible events. Stress-testing belongs to such instruments. The paper reviews and compares the models of market risk stress-testing of the portfolio of different financial instruments. These days the topic of the paper is highly acute due to the fact that now stress-testing is becoming an integral part of anticrisis risk-management amid macroeconomic instability and appearance of new risks together with close interest to the problem of risk-aggregation. The paper outlines the notion of stress-testing and gives coverage of goals, functions of stress-tests and main criteria for market risk stress-testing classification. The paper also stresses special aspects of scenario analysis. Novelty of the research is explained by elaborating the programme of aggregated complex multifactor stress-testing of the portfolio risk based on scenario analysis. The paper highlights modern Russian and foreign models of stress-testing both on solo-basis and complex. The paper lays emphasis on the results of stress-testing and revaluations of positions for all three complex models: methodology of the Central Bank of stress-testing portfolio risk, model relying on correlations analysis and copula model. The models of stress-testing on solo-basis are different for each financial instrument. Parametric StressVaR model is applicable to shares and options stress-testing;model based on "Grek" indicators is used for options; for euroobligation regional factor model is used. Finally some theoretical recommendations about managing market risk of the portfolio are given.

  3. Impulsivity and Stress Response in Pathological Gamblers During the Trier Social Stress Test.

    Science.gov (United States)

    Maniaci, G; Goudriaan, A E; Cannizzaro, C; van Holst, R J

    2018-03-01

    Gambling has been associated with increased sympathetic nervous system output and stimulation of the hypothalamic-pituitary-adrenal axis. However it is unclear how these systems are affected in pathological gambling. This study aimed to investigate the effect of the Trier Social Stress Test (TSST) on cortisol and on cardiac interbeat intervals in relation to impulsivity, in a sample of male pathological gamblers compared to healthy controls. In addition, we investigated the correlation between the TSST, duration of the disorder and impulsivity. A total of 35 pathological gamblers and 30 healthy controls, ranging from 19 to 58 years old and all male, participated in this study. Stress response was measured during and after the TSST by salivary cortisol and cardiac interbeat intervals; impulsivity was assessed with the Barratt Impulsiveness Scale (BIS-11). Exposure to the TSST produced a significant increase in salivary cortisol and interbeat intervals in both groups, without differences between groups. We found a negative correlation between baseline cortisol and duration of pathological gambling indicating that the longer the duration of the disorder the lower the baseline cortisol levels. Additionally, we found a main effect of impulsivity across groups on interbeat interval during the TSST, indicating an association between impulsivity and the intensity of the neurovegetative stress response during the TSST. Involvement of the hypothalamic-pituitary-adrenal axis in pathological gambling was confirmed together with evidence of a correlation between length of the disorder and diminished baseline cortisol levels. Impulsivity emerged as a personality trait expressed by pathological gamblers; however the neurovegetative response to the TSST, although associated with impulsivity, appeared to be independent of the presence of pathological gambling.

  4. Standard Test Method for Stress-Corrosion of Titanium Alloys by Aircraft Engine Cleaning Materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This test method establishes a test procedure for determining the propensity of aircraft turbine engine cleaning and maintenance materials for causing stress corrosion cracking of titanium alloy parts. 1.2 The evaluation is conducted on representative titanium alloys by determining the effect of contact with cleaning and maintenance materials on tendency of prestressed titanium alloys to crack when subsequently heated to elevated temperatures. 1.3 Test conditions are based upon manufacturer's maximum recommended operating solution concentration. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, see and .

  5. Standard guide for conducting and evaluating galvanic corrosion tests in electrolytes

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1981-01-01

    1.1 This guide covers conducting and evaluating galvanic corrosion tests to characterize the behavior of two dissimilar metals in electrical contact in an electrolyte under low-flow conditions. It can be adapted to wrought or cast metals and alloys. 1.2 This guide covers the selection of materials, specimen preparation, test environment, method of exposure, and method for evaluating the results to characterize the behavior of galvanic couples in an electrolyte. Note 1—Additional information on galvanic corrosion testing and examples of the conduct and evaluation of galvanic corrosion tests in electrolytes are given in Refs (1) through (7). 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicabil...

  6. The management of heat stress for the firefighter: a review of work conducted on behalf of the Toronto Fire Service.

    Science.gov (United States)

    McLellan, Tom M; Selkirk, Glen A

    2006-07-01

    This report provides a summary of research conducted through a grant provided by the Workplace Safety Insurance Board of Ontario. The research was divided into two phases; first, to define safe work limits for firefighters wearing their protective clothing and working in warm environments; and, the second, to examine strategies to reduce the thermal burden and extend the operational effectiveness of the firefighter. For the first phase, subjects wore their protective ensemble and carried their self-contained breathing apparatus (SCBA) and performed very light, light, moderate or heavy work at 25 degrees C, 30 degrees C or 35 degrees C. Thermal and evaporative resistance coefficients were obtained from thermal manikin testing that allowed the human physiological responses to be compared with modeled data. Predicted continuous work times were then generated using a heat strain model that established limits for increases in body temperature to 38.0 degrees C, 38.5 degrees C and 39.0 degrees C. Three experiments were conducted for the second phase of the project. The first study revealed that replacing the duty uniform pants that are worn under the bunker pants with shorts reduced the thermal strain for activities that lasted longer than 60 min. The second study examined the importance of fluid replacement. The data revealed that fluid replacement equivalent to at least 65% of the sweat lost increased exposure time by 15% compared with no fluid replacement. The last experiment compared active and passive cooling. Both the use of a mister or forearm and hand submersion in cool water significantly increased exposure time compared with passive cooling that involved only removing most of the protective clothing. Forearm and hand submersion proved to be most effective and produced dramatic increases in exposure time that approximated 65% compared with the passive cooling procedure. When the condition of no fluid replacement and passive cooling was compared with fluid

  7. Influence of mechanical stress level in preliminary stress-corrosion testing on fatigue strength of a low-carbon steel

    International Nuclear Information System (INIS)

    Aleskerova, S.A.; Pakharyan, V.A.

    1978-01-01

    Effect of corrosion and mechanical factors of preliminary stress corrosion of a metal in its fatigue strength, has been investigated. Smooth cylindrical samples of 20 steel have been tested. Preliminary corrosion under stress has been carried out under natural sea conditions. It is shown that mechanical stresses in the case of preliminary corrosion affect fatigue strength of low-carbon steels, decreasing the range of limited durability and fatigue limit. This effect increases with the increase of stress level and agressivity of corrosive medium

  8. Validation of the German version of the Ford Insomnia Response to Stress Test.

    Science.gov (United States)

    Dieck, Arne; Helbig, Susanne; Drake, Christopher L; Backhaus, Jutta

    2018-06-01

    The purpose of this study was to assess the psychometric properties of a German version of the Ford Insomnia Response to Stress Test with groups with and without sleep problems. Three studies were analysed. Data set 1 was based on an initial screening for a sleep training program (n = 393), data set 2 was based on a study to test the test-retest reliability of the Ford Insomnia Response to Stress Test (n = 284) and data set 3 was based on a study to examine the influence of competitive sport on sleep (n = 37). Data sets 1 and 2 were used to test internal consistency, factor structure, convergent validity, discriminant validity and test-retest reliability of the Ford Insomnia Response to Stress Test. Content validity was tested using data set 3. Cronbach's alpha of the Ford Insomnia Response to Stress Test was good (α = 0.80) and test-retest reliability was satisfactory (r = 0.72). Overall, the one-factor model showed the best fit. Furthermore, significant positive correlations between the Ford Insomnia Response to Stress Test and impaired sleep quality, depression and stress reactivity were in line with the expectations regarding the convergent validity. Subjects with sleep problems had significantly higher scores in the Ford Insomnia Response to Stress Test than subjects without sleep problems (P Stress Test had significantly lower sleep quality (P = 0.01), demonstrating that vulnerability for stress-induced sleep disturbances accompanies poorer sleep quality in stressful episodes. The findings show that the German version of the Ford Insomnia Response to Stress Test is a reliable and valid questionnaire to assess the vulnerability to stress-induced sleep disturbances. © 2017 European Sleep Research Society.

  9. Photoacoustic infrared spectroscopy for conducting gas tracer tests and measuring water saturations in landfills

    International Nuclear Information System (INIS)

    Jung, Yoojin; Han, Byunghyun; Mostafid, M. Erfan; Chiu, Pei; Yazdani, Ramin; Imhoff, Paul T.

    2012-01-01

    Highlights: ► Photoacoustic infrared spectroscopy tested for measuring tracer gas in landfills. ► Measurement errors for tracer gases were 1–3% in landfill gas. ► Background signals from landfill gas result in elevated limits of detection. ► Technique is much less expensive and easier to use than GC. - Abstract: Gas tracer tests can be used to determine gas flow patterns within landfills, quantify volatile contaminant residence time, and measure water within refuse. While gas chromatography (GC) has been traditionally used to analyze gas tracers in refuse, photoacoustic spectroscopy (PAS) might allow real-time measurements with reduced personnel costs and greater mobility and ease of use. Laboratory and field experiments were conducted to evaluate the efficacy of PAS for conducting gas tracer tests in landfills. Two tracer gases, difluoromethane (DFM) and sulfur hexafluoride (SF 6 ), were measured with a commercial PAS instrument. Relative measurement errors were invariant with tracer concentration but influenced by background gas: errors were 1–3% in landfill gas but 4–5% in air. Two partitioning gas tracer tests were conducted in an aerobic landfill, and limits of detection (LODs) were 3–4 times larger for DFM with PAS versus GC due to temporal changes in background signals. While higher LODs can be compensated by injecting larger tracer mass, changes in background signals increased the uncertainty in measured water saturations by up to 25% over comparable GC methods. PAS has distinct advantages over GC with respect to personnel costs and ease of use, although for field applications GC analyses of select samples are recommended to quantify instrument interferences.

  10. Skin conductance rises in preparation and recovery to psychosocial stress and its relationship with impulsivity and testosterone in intimate partner violence perpetrators.

    Science.gov (United States)

    Romero-Martínez, A; Lila, M; Williams, R K; González-Bono, E; Moya-Albiol, L

    2013-12-01

    Intimate partner violence (IPV) perpetrators were categorized into 2 groups using Gottman et al.'s (1995) typology depending on their skin conductance (SC) reactivity to stress. Overall, type I perpetrators tend to show autonomic underarousal, whereas type II perpetrators present a preparatory hyperreactivity to confront stress. Moreover, impulsivity traits and testosterone (T) levels may modulate SC responses to increase the risk of proneness to violence. In this study, SC response to stress was assessed by comparing IPV perpetrators with non-violent controls while performing a modified version of the Trier Social Stress Test (TSST). Subjects with a history of IPV demonstrated higher non-specific SC responses during the recovery period than the non-violent controls. Nonetheless, there were no differences between groups in the case of mean SC levels. Furthermore, impulsivity and baseline T levels were associated with higher SC level reactivity during a preparation period only in IPV perpetrators, with both relationships being mediated by anger expression. Our results confirm that the IPV perpetrators correspond physiologically to type II and support the validity of SC as a diagnostic indicator for IPV classification. Our findings contribute to the development of effective treatment and prevention programs that could benefit from the use of biological indicators for analyzing the risk of recidivism in IPV perpetrators. © 2013.

  11. A novel method for estimating soil precompression stress from uniaxial confined compression tests

    DEFF Research Database (Denmark)

    Lamandé, Mathieu; Schjønning, Per; Labouriau, Rodrigo

    2017-01-01

    . Stress-strain curves were obtained by performing uniaxial, confined compression tests on undisturbed soil cores for three soil types at three soil water potentials. The new method performed better than the Gompertz fitting method in estimating precompression stress. The values of precompression stress...... obtained from the new method were linearly related to the maximum stress experienced by the soil samples prior to the uniaxial, confined compression test at each soil condition with a slope close to 1. Precompression stress determined with the new method was not related to soil type or dry bulk density......The concept of precompression stress is used for estimating soil strength of relevance to fieldtraffic. It represents the maximum stress experienced by the soil. The most recently developed fitting method to estimate precompression stress (Gompertz) is based on the assumption of an S-shape stress...

  12. Characteristics of acoustic wave from atmospheric nuclear explosions conducted at the USSR Test Sites

    Science.gov (United States)

    Sokolova, Inna

    2015-04-01

    Availability of the acoustic wave on the record of microbarograph is one of discriminate signs of atmospheric (surface layer of atmosphere) and contact explosions. Nowadays there is large number of air wave records from chemical explosions recorded by the IMS infrasound stations installed during recent decade. But there is small number of air wave records from nuclear explosions as air and contact nuclear explosions had been conducted since 1945 to 1962, before the Limited Test Ban Treaty was signed in 1963 (the treaty banning nuclear weapon tests in the atmosphere, in outer space and under water) by the Great Britain, USSR and USA. That time there was small number of installed microbarographs. First infrasound stations in the USSR appeared in 1954, and by the moment of the USSR collapse the network consisted of 25 infrasound stations, 3 of which were located on Kazakhstan territory - in Kurchatov (East Kazakhstan), in Borovoye Observatory (North Kazakhstan) and Talgar Observatory (Northern Tien Shan). The microbarograph of Talgar Observatory was installed in 1962 and recorded large number of air nuclear explosions conducted at Semipalatinsk Test Site and Novaya Zemlya Test Site. The epicentral distance to the STS was ~700 km, and to Novaya Zemlya Test Site ~3500 km. The historical analog records of the microbarograph were analyzed on the availability of the acoustic wave. The selected records were digitized, the database of acoustic signals from nuclear explosions was created. In addition, acoustic signals from atmospheric nuclear explosions conducted at the USSR Test Sites were recorded by analogue broadband seismic stations at wide range of epicentral distances, 300-3600 km. These signals coincide well by its form and spectral content with records of microbarographs and can be used for monitoring tasks and discrimination in places where infrasound observations are absent. Nuclear explosions which records contained acoustic wave were from 0.03 to 30 kt yield for

  13. Type A behavior and the thallium stress test

    International Nuclear Information System (INIS)

    Kahn, J.P.; Kornfeld, D.S.; Blood, D.K.; Lynn, R.B.; Heller, S.S.; Frank, K.A.

    1982-01-01

    Several recent studies have examined the association between Type A personality and coronary artery disease (CAD) by coronary angiography. Most of these studies have reported a significant association. The present study is an attempt at further confirmation, using a new non-invasive technique for measuring CAD. Subjects were 53 patients undergoing routine exercise stress tests with concomitant thallium-201 myocardial perfusion studies. Five aspects of Type A behavior were assessed by the use of the Rosenman-Friedman Semistructured Interview, and each was rated on a three-point scale. Severity of CAD was independently estimated on a four-point scale. Pearson correlation coefficients were separately computed for patients with and without reported history of myocardial infarction (MI). For 37 patients without reported MI, CAD severity was significantly correlated with Overall Type A (r . -0.53), Vocal Characteristics (r . -0.53), Job Involvement (r . -0.36) and Aggressiveness (r . -0.48), but not Time Urgency (r . -0.25). For 16 patients with reported MI, CAD severity was significantly correlated with Job Involvement only (r . +0.49). The data are consistent with the association of Type A personality and coronary atherogenesis, but may also reflect Type A psychological and physiological characteristics. Future studies may be able to examine these and other aspects of Type A behavior using this noninvasive technique in more diverse patient populations

  14. Safety and efficacy of Regadenoson in myocardial perfusion imaging (MPI) stress tests: A review

    Science.gov (United States)

    Ahmed, Ambereen

    2018-02-01

    Myocardial perfusion imaging (MPI) tests are often used to help diagnose coronary heart disease (CAD). The tests usually involve applying stress, such as hard physical exercise together with administration of vasodilators, to the patients. To date, many of these tests use non-selective A2A adenosine receptor agonists which, however, can be associated with highly undesirable and life-threatening side effects such as chest pain, dyspnea, severe bronchoconstriction and atrioventricular conduction anomalies. Regadenoson is a relatively new, highly selective A2A adenosine receptor agonist, suitable for use in MPI tests which exhibits far fewer adverse side effects and, unlike others testing agents, can be used without the necessity of excessive concomitant exercise. Also, the dose of regadenoson required is not dependent upon patient weight or renal impairment, and it can be rapidly administered by i.v. Injection. Regadenoson use in MPI testing thus has the potential as a simplified, relatively safe, time-saving and cost-effective method for helping diagnose CAD. The present study was designed to review several articles on the safety, efficacy, and suitability of regadenoson in MPI testing for CAD. Overall, the combined studies demonstrated that use of regadenoson in conjunction with low-level exercise in MPI is a highly efficient and relatively safe test for CAD, especially for more severe health-compromised patients.

  15. Results of stress tests of European nuclear power plants after the Fukushima-Daiichi accident

    International Nuclear Information System (INIS)

    Kovacs, Zoltan; Novakova, Helena

    2012-01-01

    In response to the Fukushima-Daiichi accident, the European Council laid down the requirement that a transparent and comprehensive risk assessment exercise ('stress tests') be carried out at each European nuclear power plant. The stress tests concentrated on the nuclear power plants' safety margins in the light of the lessons learned from the accident. The reviews focused on natural external events including earthquake, tsunami and extreme weather, loss of safety functions, and severe accident management. The stress test procedure comprised 3 steps: (i) The nuclear facility operators performed the stress tests and prepared proposals for safety improvements. (ii) The national regulators performed independent reviews of the stress tests and prepared national reports. (iii) The reports submitted by the national regulators were subjected to review at a European level. The article describes the scope of the stress tests and their results, verified at the European level. (orig.)

  16. Thermal Conductivity Analysis and Lifetime Testing of Suspension Plasma-Sprayed Thermal Barrier Coatings

    Directory of Open Access Journals (Sweden)

    Nicholas Curry

    2014-08-01

    Full Text Available Suspension plasma spraying (SPS has become an interesting method for the production of thermal barrier coatings for gas turbine components. The development of the SPS process has led to structures with segmented vertical cracks or column-like structures that can imitate strain-tolerant air plasma spraying (APS or electron beam physical vapor deposition (EB-PVD coatings. Additionally, SPS coatings can have lower thermal conductivity than EB-PVD coatings, while also being easier to produce. The combination of similar or improved properties with a potential for lower production costs makes SPS of great interest to the gas turbine industry. This study compares a number of SPS thermal barrier coatings (TBCs with vertical cracks or column-like structures with the reference of segmented APS coatings. The primary focus has been on lifetime testing of these new coating systems. Samples were tested in thermo-cyclic fatigue at temperatures of 1100 °C for 1 h cycles. Additional testing was performed to assess thermal shock performance and erosion resistance. Thermal conductivity was also assessed for samples in their as-sprayed state, and the microstructures were investigated using SEM.

  17. Model-Based Prediction of Pulsed Eddy Current Testing Signals from Stratified Conductive Structures

    International Nuclear Information System (INIS)

    Zhang, Jian Hai; Song, Sung Jin; Kim, Woong Ji; Kim, Hak Joon; Chung, Jong Duk

    2011-01-01

    Excitation and propagation of electromagnetic field of a cylindrical coil above an arbitrary number of conductive plates for pulsed eddy current testing(PECT) are very complex problems due to their complicated physical properties. In this paper, analytical modeling of PECT is established by Fourier series based on truncated region eigenfunction expansion(TREE) method for a single air-cored coil above stratified conductive structures(SCS) to investigate their integrity. From the presented expression of PECT, the coil impedance due to SCS is calculated based on analytical approach using the generalized reflection coefficient in series form. Then the multilayered structures manufactured by non-ferromagnetic (STS301L) and ferromagnetic materials (SS400) are investigated by the developed PECT model. Good prediction of analytical model of PECT not only contributes to the development of an efficient solver but also can be applied to optimize the conditions of experimental setup in PECT

  18. Acute heat stress induces differential gene expressions in the testes of a broiler-type strain of Taiwan country chickens.

    Science.gov (United States)

    Wang, Shih-Han; Cheng, Chuen-Yu; Tang, Pin-Chi; Chen, Chih-Feng; Chen, Hsin-Hsin; Lee, Yen-Pai; Huang, San-Yuan

    2015-01-01

    The expression of testicular genes following acute heat stress has been reported in layer-type roosters, but few similar studies have been conducted on broilers. This study investigated the effect of acute heat stress on the gene expression in the testes of a broiler-type strain of Taiwan country chickens. Roosters were subjected to acute heat stress (38°C) for 4 h, and then exposed to 25°C, with testes collected 0, 2, and 6 h after the cessation of heat stress, using non-heat-stressed roosters as controls (n = 3 roosters per group). The body temperature and respiratory rate increased significantly (pstress. The numbers of apoptotic cells increased 2 h after the acute heat stress (79 ± 7 vs. 322 ± 192, control vs. heat stress; pstressed chickens from those of the controls, including genes involved in the response to stimulus, protein metabolism, signal transduction, cell adhesion, transcription, and apoptosis. The mRNA expressions of upregulated genes, including HSP25, HSP90AA1, HSPA2, and LPAR2, and of downregulated genes, including CDH5, CTNNA3, EHF, CIRBP, SLA, and NTF3, were confirmed through quantitative real-time polymerase chain reaction (qRT-PCR). Moreover, numerous transcripts in the testes exhibited distinct expressions between the heat-stressed broiler-type and layer-type chickens. We concluded that the transcriptional responses of testes to acute heat stress may differ between the broiler-type and layer-type roosters. Whether the differential expression patterns associate with the heat-tolerance in the strains require a further exploration.

  19. Sweat conductivity and coulometric quantitative test in neonatal cystic fibrosis screening

    Directory of Open Access Journals (Sweden)

    Mouseline Torquato Domingos

    2015-11-01

    Full Text Available Objective: To compare the results obtained with the sweat test using the conductivity method and coulometric measurement of sweat chloride in newborns (NBs with suspected cystic fibrosis (CF in the neonatal screening program. Methods: The sweat test was performed simultaneously by both methods in children with and without CF. The cutoff values to confirm CF were >50 mmol/L in the conductivity and >60 mmol/L in the coulometric test. Results: There were 444 infants without CF (185 males, 234 females, and 24 unreported submitted to the sweat test through conductivity and coulometric measurement simultaneously, obtaining median results of 32 mmol/L and 12 mmol/L, respectively. For 90 infants with CF, the median values of conductivity and coulometric measurement were 108 mmol/L and 97 mmol/L, respectively. The false positive rate for conductivity was 16.7%, and was higher than 50 mmol/L in all patients with CF, which gives this method a sensitivity of 100% (95% CI: 93.8–97.8, specificity of 96.2% (95% CI: 93.8–97.8, positive predictive value of 83.3% (95% CI: 74.4–91.1, negative predictive value of 100% (95% CI: 90.5–109.4, and 9.8% accuracy. The correlation between the methods was r = 0.97 (p > 0.001. The best suggested cutoff value was 69.0 mmol/L, with a kappa coefficient = 0.89. Conclusion: The conductivity test showed excellent correlation with the quantitative coulometric test, high sensitivity and specificity, and can be used in the diagnosis of CF in children detected through newborn screening. Resumo: Objetivo: Comparar os resultados obtidos no teste do suor pelo método da condutividade e a dosagem coulométrica de cloreto no suor em recém nascidos (RN suspeitos da triagem neonatal para fibrose cística (FC. Métodos: O teste do suor foi realizado simultaneamente pelos dois métodos em crianças com e sem FC. Os valores de corte para confirmar FC foram na condutividade > 50 mmol/L e no teste coulométrico > 60

  20. Stress test performed on gas transport pipelines as a method for quality assurance

    International Nuclear Information System (INIS)

    Kuelzer, J.; Baessler, R.

    1991-01-01

    Modern pipeline construction increasingly uses the stress test as an integral component test while aiming at enhanced safety and availability. The application described by the article highlights the particular fact that expanded and non-expanded pipes of identical material quality will reveal a different behaviour in the stress test. (orig.) [de

  1. Wolff-Parkinson-White syndrome: a single exercise stress test might be misleading.

    Science.gov (United States)

    Salavitabar, Arash; Silver, Eric S; Liberman, Leonardo

    2017-05-01

    Risk stratification of patients with Wolff-Parkinson-White syndrome for sudden death is a complex process, particularly in understanding the utility of the repeat exercise stress test. We report a case of an 18-year-old patient who was found to have a high-risk pathway by both invasive and exercise stress testing after an initial exercise stress test showing beat-to-beat loss of pre-excitation.

  2. The impact of training process on the stress tests results of women cross country skiing representation.

    OpenAIRE

    Fusková, Dana

    2015-01-01

    Title: The impact of training process on the stress tests results of women cross country skiing representation. Aim: The aim of this thesis is the comparison of the results of stress tests carried out preparatory period before and after the preparation period and whether the results were influenced by the applied training process. Methods: In this thesis was used background research of professional publications, content analyzes of documents and comparison of the results of stress tests and c...

  3. Information content of slug tests for estimating hydraulic properties in realistic, high-conductivity aquifer scenarios

    Science.gov (United States)

    Cardiff, Michael; Barrash, Warren; Thoma, Michael; Malama, Bwalya

    2011-06-01

    SummaryA recently developed unified model for partially-penetrating slug tests in unconfined aquifers ( Malama et al., in press) provides a semi-analytical solution for aquifer response at the wellbore in the presence of inertial effects and wellbore skin, and is able to model the full range of responses from overdamped/monotonic to underdamped/oscillatory. While the model provides a unifying framework for realistically analyzing slug tests in aquifers (with the ultimate goal of determining aquifer properties such as hydraulic conductivity K and specific storage Ss), it is currently unclear whether parameters of this model can be well-identified without significant prior information and, thus, what degree of information content can be expected from such slug tests. In this paper, we examine the information content of slug tests in realistic field scenarios with respect to estimating aquifer properties, through analysis of both numerical experiments and field datasets. First, through numerical experiments using Markov Chain Monte Carlo methods for gauging parameter uncertainty and identifiability, we find that: (1) as noted by previous researchers, estimation of aquifer storage parameters using slug test data is highly unreliable and subject to significant uncertainty; (2) joint estimation of aquifer and skin parameters contributes to significant uncertainty in both unless prior knowledge is available; and (3) similarly, without prior information joint estimation of both aquifer radial and vertical conductivity may be unreliable. These results have significant implications for the types of information that must be collected prior to slug test analysis in order to obtain reliable aquifer parameter estimates. For example, plausible estimates of aquifer anisotropy ratios and bounds on wellbore skin K should be obtained, if possible, a priori. Secondly, through analysis of field data - consisting of over 2500 records from partially-penetrating slug tests in a

  4. Safe affordable fission engine (SAFE 30) module conductivity test thermal model correlation

    International Nuclear Information System (INIS)

    Roman, Jose

    2001-01-01

    The SAFE 30 is a simple, robust space fission power system that is comprised of several independent modules. Each module contains 4 fuel tubes bonded to a central heatpipe. Fission energy is conducted from the fuel tubes to the heatpipe, which in turn transfers the energy to a power conversion system. This paper benchmarks a thermal model of the SAFE 30 with actual test data from simulated SAFE 30 module tests. Two 'dummy' SAFE 30 modules were fabricated - each consisted of 4 1-inch dia. tubes (simulating the fuel tubes) bonded to a central '1' dia. tube (simulating the heatpipe). In the first module the fuel tubes were simply brazed to the heatpipe along the line of contact (leaving void space in the interstices), and in the second module the tubes and heatpipe were brazed via tri-cusps that completely fill the interstices between the tubes. In these tests, fission energy is simulated by placing resistance heaters within each of the 4 fuel tubes. The tests were conducted in a vacuum chamber in 4 configurations: tri-cusps filled with and without an outer insulation wrap, and no tri-cusps with and without an outer insulation wrap. The baseline SAFE 30 configuration uses the brazed tri-cusps. During the tests, the power applied to the heaters was varied in a stepwise fashion, until a steady-state temperature profile was reached. These temperature levels varied between 773 K and 1073 K. To benchmark the thermal model, the input energy and chamber surface temperature were used as boundary conditions for the model. The analytical results from the nodes at the same location as the test thermocouples were plotted again test data to determinate the accuracy of the analysis. The unknown variables on the analysis are the radiation emissivity of the pipe and chamber and the radiation view factor between the module and the chamber. A correlation was determined using a parametric analysis by varying the surface emissivity and view factor until a good match was reached. This

  5. Environmental radiation at the Monte Bello Islands from nuclear weapons tests conducted in 1952 and 1956

    International Nuclear Information System (INIS)

    Moroney, J.R.; Cooper, M.B.

    1982-12-01

    The results from the 1962 and 1968 surveys of environmental radiation at the Monte Bello Islands are presented. These were the first of the series of surveys of radioactive contamination of the Islands to be carried out following nuclear weapons tests conducted in 1952 and 1956. Detailed comparison is made with the results obtained in the subsequent surveys in 1972 and 1978. For more than 20 years, no area at the Monte Bello Islands has presented an acute hazard due to external exposure to environmental radiation

  6. Analyses of production tests and MDT tests conducted in Mallik and Alaska methane hydrate reservoirs : what can we learn from these well tests?

    Energy Technology Data Exchange (ETDEWEB)

    Kurihara, M.; Funatsu, K.; Ouchi, H. [Japan Oil Engineering Co., Tokyo (Japan); Masuda, Y. [Tokyo Univ., Tokyo (Japan). School of Engineering; Yamamoto, K. [Japan Oil, Gas and Metals National Corp., Tokyo (Japan); Narita, H. [National Inst. of Advanced Industrial Science and Technology, Tokyo (Japan); Dallimore, S.R. [Natural Resources Canada, Ottawa, ON (Canada). Geological Survey of Canada; Collett, T.S. [United States Geological Survey, Reston, VA (United States); Hancock, S.H. [APA Petroleum Engineering Ltd., Calgary, AB (Canada)

    2008-07-01

    This paper described a series of pressure drawdown tests conducted to evaluate a modular formation dynamics tester (MDT) wireline tool. The tests were conducted at the Mallik methane hydrate (MH) reservoir as well as in MH reservoirs in Alaska over a period of several years. Production tests were also conducted to evaluate depressurization methods, and measure production and bottomhole pressure (BHP) below known MH stability pressures in order to estimate permeability and MH dissociation radius properties. The results of the tests were then history-matched using a numerical simulator. An analysis of the simulation study showed that the MDT tests were useful in estimating initial effective permeability levels in the presence of MH. However, wellbore storage erased important data used to indicate the radius of MH dissociation and effective permeability after partial MH dissociation. The study also showed that steady flow conditions must be established before obtaining solutions from history-matched production tests. Parameters accurately estimated using the MDT and production tests were outlined, and suggestions for future designs and analyses for MH reservoirs were presented. 14 refs., 7 tabs., 17 figs.

  7. Light brick mortar with low thermal conductivity for stressed brickwork. Types, properties, limits of application

    Energy Technology Data Exchange (ETDEWEB)

    Plank, A [Bundesanstalt fuer Materialpruefung, Berlin (Germany, F.R.)

    1980-03-01

    Between 40 and 50% of the total energy consumption are used for space heating. 40% of the total heat loss dissipate through external walls due to transmission. The heat insulation properties of a brickwork is decisively determined by the mortar joints. Using light brick mortars with low thermal conductivity an improvement of the total thermal insulation of nearly 20% can be reached in most of the cases. The mechanical properties of these mortars that differ from the common mortars decisively reduce the application of the light brick mortar in brick working and require special measures for stability which are described in detail.

  8. Drying tests conducted on Three Mile Island fuel canisters containing simulated debris

    International Nuclear Information System (INIS)

    Palmer, A.J.

    1995-01-01

    Drying tests were conducted on TMI-2 fuel canisters filled with simulated core debris. During these tests, canisters were dried by heating externally by a heating blanket while simultaneously purging the canisters' interior with hot, dry nitrogen. Canister drying was found to be dominated by moisture retention properties of a concrete filler material (LICON) used for geometry control. This material extends the drying process 10 days or more beyond what would be required were it not there. The LICON resides in a nonpurgeable chamber separate from the core debris, and because of this configuration, dew point measurements on the exhaust stream do not provide a good indication of the dew point in the canisters. If the canisters are not dried, but rather just dewatered, 140-240 lb of water (not including the LICON water of hydration) will remain in each canister, approximately 50-110 lb of which is pore water in the LICON and the remainder unbound water

  9. Variations in hydraulic conductivity with scale of measurement during aquifer tests in heterogeneous, porous carbonate rocks

    Science.gov (United States)

    Schulze-Makuch, Dirk; Cherkauer, Douglas S.

    Previous studies have shown that hydraulic conductivity of an aquifer seems to increase as the portion of the aquifer tested increases. To date, such studies have all relied on different methods to determine hydraulic conductivity at each scale of interest, which raises the possibility that the observed increase in hydraulic conductivity is due to the measurement method, not to the scale. This study analyzes hydraulic conductivity with respect to scale during individual aquifer tests in porous, heterogeneous carbonate rocks in southeastern Wisconsin, USA. Results from this study indicate that hydraulic conductivity generally increases during an individual test as the volume of aquifer impacted increases, and the rate of this increase is the same as the rate of increase determined by using different measurement methods. Thus, scale dependence of hydraulic conductivity during single tests does not depend on the method of measurement. This conclusion is supported by 22 of 26 aquifer tests conducted in porous-flow-dominated carbonate units within the aquifer. Instead, scale dependency is probably caused by heterogeneities within the aquifer, a conclusion supported by digital simulation. All of the observed types of hydraulic-conductivity variations with scale during individual aquifer tests can be explained by a conceptual model of a simple heterogeneous aquifer composed of high-conductivity zones within a low-conductivity matrix. Résumé Certaines études ont montré que la conductivité hydraulique d'un aquifère semble augmenter en même temps que la partie testée de l'aquifère s'étend. Jusqu'à présent, ces études ont toutes reposé sur des méthodes de détermination de la conductivité hydraulique différentes pour chaque niveau d'échelle, ce qui a conduit à penser que l'augmentation observée de la conductivité hydraulique pouvait être due aux méthodes de mesure et non à l'effet d'échelle. Cette étude analyse la conductivité hydraulique par

  10. 21 CFR 20.105 - Testing and research conducted by or with funds provided by the Food and Drug Administration.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Testing and research conducted by or with funds... Categories of Records § 20.105 Testing and research conducted by or with funds provided by the Food and Drug Administration. (a) Any list that may be prepared by the Food and Drug Administration of testing and research...

  11. Help-Seeking Decisions of Battered Women: A Test of Learned Helplessness and Two Stress Theories.

    Science.gov (United States)

    Wauchope, Barbara A.

    This study tested the learned helplessness theory, stress theory, and a modified stress theory to determine the best model for predicting the probability that a woman would seek help when she experienced severe violence from a male partner. The probability was hypothesized to increase as the stress of the violence experienced increased. Data were…

  12. Using Uncertainty Analysis to Guide the Development of Accelerated Stress Tests (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Kempe, M.

    2014-03-01

    Extrapolation of accelerated testing to the long-term results expected in the field has uncertainty associated with the acceleration factors and the range of possible stresses in the field. When multiple stresses (such as temperature and humidity) can be used to increase the acceleration, the uncertainty may be reduced according to which stress factors are used to accelerate the degradation.

  13. Standard test method for conducting friction tests of piston ring and cylinder liner materials under lubricated conditions

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This test method covers procedures for conducting laboratory bench-scale friction tests of materials, coatings, and surface treatments intended for use in piston rings and cylinder liners in diesel or spark-ignition engines. The goal of this procedure is to provide a means for preliminary, cost-effective screening or evaluation of candidate ring and liner materials. A reciprocating sliding arrangement is used to simulate the contact that occurs between a piston ring and its mating liner near the top-dead-center position in the cylinder where liquid lubrication is least effective, and most wear is known to occur. Special attention is paid to specimen alignment, running-in, and lubricant condition. 1.2 This test method does not purport to simulate all aspects of a fired engine’s operating environment, but is intended to serve as a means for preliminary screening for assessing the frictional characteristics of candidate piston ring and liner material combinations in the presence of fluids that behave as u...

  14. Study on constant-step stress accelerated life tests in white organic light-emitting diodes.

    Science.gov (United States)

    Zhang, J P; Liu, C; Chen, X; Cheng, G L; Zhou, A X

    2014-11-01

    In order to obtain reliability information for a white organic light-emitting diode (OLED), two constant and one step stress tests were conducted with its working current increased. The Weibull function was applied to describe the OLED life distribution, and the maximum likelihood estimation (MLE) and its iterative flow chart were used to calculate shape and scale parameters. Furthermore, the accelerated life equation was determined using the least squares method, a Kolmogorov-Smirnov test was performed to assess if the white OLED life follows a Weibull distribution, and self-developed software was used to predict the average and the median lifetimes of the OLED. The numerical results indicate that white OLED life conforms to a Weibull distribution, and that the accelerated life equation completely satisfies the inverse power law. The estimated life of a white OLED may provide significant guidelines for its manufacturers and customers. Copyright © 2014 John Wiley & Sons, Ltd.

  15. A New Method for a Virtue-Based Responsible Conduct of Research Curriculum: Pilot Test Results.

    Science.gov (United States)

    Berling, Eric; McLeskey, Chet; O'Rourke, Michael; Pennock, Robert T

    2018-02-03

    Drawing on Pennock's theory of scientific virtues, we are developing an alternative curriculum for training scientists in the responsible conduct of research (RCR) that emphasizes internal values rather than externally imposed rules. This approach focuses on the virtuous characteristics of scientists that lead to responsible and exemplary behavior. We have been pilot-testing one element of such a virtue-based approach to RCR training by conducting dialogue sessions, modeled upon the approach developed by Toolbox Dialogue Initiative, that focus on a specific virtue, e.g., curiosity and objectivity. During these structured discussions, small groups of scientists explore the roles they think the focus virtue plays and should play in the practice of science. Preliminary results have shown that participants strongly prefer this virtue-based model over traditional methods of RCR training. While we cannot yet definitively say that participation in these RCR sessions contributes to responsible conduct, these pilot results are encouraging and warrant continued development of this virtue-based approach to RCR training.

  16. Testing hypotheses that link wood anatomy to cavitation resistance and hydraulic conductivity in the genus Acer.

    Science.gov (United States)

    Lens, Frederic; Sperry, John S; Christman, Mairgareth A; Choat, Brendan; Rabaey, David; Jansen, Steven

    2011-05-01

    • Vulnerability to cavitation and conductive efficiency depend on xylem anatomy. We tested a large range of structure-function hypotheses, some for the first time, within a single genus to minimize phylogenetic 'noise' and maximize detection of functionally relevant variation. • This integrative study combined in-depth anatomical observations using light, scanning and transmission electron microscopy of seven Acer taxa, and compared these observations with empirical measures of xylem hydraulics. • Our results reveal a 2 MPa range in species' mean cavitation pressure (MCP). MCP was strongly correlated with intervessel pit structure (membrane thickness and porosity, chamber depth), weakly correlated with pit number per vessel, and not related to pit area per vessel. At the tissue level, there was a strong correlation between MCP and mechanical strength parameters, and some of the first evidence is provided for the functional significance of vessel grouping and thickenings on inner vessel walls. In addition, a strong trade-off was observed between xylem-specific conductivity and MCP. Vessel length and intervessel wall characteristics were implicated in this safety-efficiency trade-off. • Cavitation resistance and hydraulic conductivity in Acer appear to be controlled by a very complex interaction between tissue, vessel network and pit characteristics. © 2010 The Authors. New Phytologist © 2010 New Phytologist Trust.

  17. Techniques Employed to Conduct Postshot Drilling at the former Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Dekin, W D

    2011-04-14

    Postshot drilling provided essential data on the results of the underground nuclear tests conducted at the Nevada Test Site (NTS), now identified as the Nevada National Security Site (NNSS). It was the means by which samples from the zone of interest were obtained for radiochemical analysis. This handbook describes how Lawrence Livermore National Laboratory (LLNL) conducted postshot drilling operations at the NTS, and it provides a general understanding of the process. Postshot drilling is a specialized application of rotary drilling. Accordingly, this handbook gives a brief description of rotary drilling in Section 2 to acquaint the reader with the general subject before proceeding to the specialized techniques used in postshot drilling. In Section 3, the handbook describes the typical postshot drilling situation at the former NTS and the drilling methods used. Section 4 describes the typical sequence of operations in postshot drilling at the former NTS. Detailed information on special equipment and techniques is given in a series of appendices (A through F) at the end of the handbook.

  18. When we test, do we stress? Impact of the testing environment on cortisol secretion and memory performance in older adults.

    Science.gov (United States)

    Sindi, Shireen; Fiocco, Alexandra J; Juster, Robert-Paul; Pruessner, Jens; Lupien, Sonia J

    2013-08-01

    The majority of studies find that older adults have worse memory performance than young adults. However, contextual features in the testing environment may be perceived as stressful by older adults, increasing their stress hormone levels. Given the evidence that older adults are highly sensitive to the effects of stress hormones (cortisol) on memory performance, it is postulated that a stressful testing environment in older adults can lead to an acute stress response and to memory impairments. The current study compared salivary cortisol levels and memory performance in young and older adults tested in environments manipulated to be stressful (unfavourable condition) or not stressful (favourable condition) for each age group. 28 young adults and 32 older adults were tested in two testing conditions: (1) a condition favouring young adults (constructed to be less stressful for young adults), and (2) a condition favouring older adults (constructed to be less stressful for older adults). The main outcome measure was salivary cortisol levels. Additionally, immediate and delayed memory performances were assessed during each condition. In older adults only, we found significantly high cortisol levels and low memory performance in the condition favouring young adults. In contrast, cortisol levels were lower and memory performance was better when older adults were tested in conditions favouring them. There was no effect of testing condition in young adults. The results demonstrate that older adults' memory performance is highly sensitive to the testing environment. These findings have important implications for both research and clinical settings in which older adults are tested for memory performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. Stress Wave Attenuation in Aluminum Alloy and Mild Steel Specimens Under SHPB Tensile Testing

    Science.gov (United States)

    Pothnis, J. R.; Ravikumar, G.; Arya, H.; Yerramalli, Chandra S.; Naik, N. K.

    2018-02-01

    Investigations on the effect of intensity of incident pressure wave applied through the striker bar on the specimen force histories and stress wave attenuation during split Hopkinson pressure bar (SHPB) tensile testing are presented. Details of the tensile SHPB along with Lagrangian x- t diagram of the setup are included. Studies were carried out on aluminum alloy 7075 T651 and IS 2062 mild steel. While testing specimens using the tensile SHPB setup, it was observed that the force calculated from the transmitter bar strain gauge was smaller than the force obtained from the incident bar strain gauge. This mismatch between the forces in the incident bar and the transmitter bar is explained on the basis of stress wave attenuation in the specimens. A methodology to obtain force histories using the strain gauges on the specimen during SHPB tensile testing is also presented. Further, scanning electron microscope images and photomicrographs are given. Correlation between the microstructure and mechanical properties is explained. Further, uncertainty analysis was conducted to ascertain the accuracy of the results.

  20. Estimation of the Blood Pressure Response With Exercise Stress Testing.

    Science.gov (United States)

    Fitzgerald, Benjamin T; Ballard, Emma L; Scalia, Gregory M

    2018-04-20

    The blood pressure response to exercise has been described as a significant increase in systolic BP (sBP) with a smaller change in diastolic BP (dBP). This has been documented in small numbers, in healthy young men or in ethnic populations. This study examines these changes in low to intermediate risk of myocardial ischaemia in men and women over a wide age range. Consecutive patients having stress echocardiography were analysed. Ischaemic tests were excluded. Manual BP was estimated before and during standard Bruce protocol treadmill testing. Patient age, sex, body mass index (BMI), and resting and peak exercise BP were recorded. 3200 patients (mean age 58±12years) were included with 1123 (35%) females, and 2077 males, age range 18 to 93 years. Systolic BP increased from 125±17mmHg to 176±23mmHg. The change in sBP (ΔsBP) was 51mmHg (95% CI 51,52). The ΔdBP was 1mmHg (95% CI 1, 1), from 77 to 78mmHg, p<0.001). The upper limit of normal peak exercise sBP (determined by the 90th percentile) was 210mmHg in males and 200mmHg in females. The upper limit of normal ΔsBP was 80mmHg in males and 70mmHg in females. The lower limit of normal ΔsBP was 30mmHg in males and 20mmHg in females. In this large cohort, sBP increased significantly with exercise. Males had on average higher values than females. Similar changes were seen with the ΔsBP. The upper limit of normal for peak exercise sBP and ΔsBP are reported by age and gender. Copyright © 2018 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) and the Cardiac Society of Australia and New Zealand (CSANZ). All rights reserved.

  1. Sequential Indentation Tests to Investigate the Influence of Confining Stress on Rock Breakage by Tunnel Boring Machine Cutter in a Biaxial State

    Science.gov (United States)

    Liu, Jie; Cao, Ping; Han, Dongya

    2016-04-01

    The influence of confining stress on rock breakage by a tunnel boring machine cutter was investigated by conducting sequential indentation tests in a biaxial state. Combined with morphology measurements of breaking grooves and an analysis of surface and internal crack propagation between nicks, the effects of maximum confining stress and minimum stress on indentation efficiency, crack propagation and chip formation were investigated. Indentation tests and morphology measurements show that increasing a maximum confining stress will result in increased consumed energy in indentations, enlarged groove volumes and promoted indentation efficiency when the corresponding minimum confining stress is fixed. The energy consumed in indentations will increase with increase in minimum confining stress, however, because of the decreased groove volumes as the minimum confining stress increases, the efficiency will decrease. Observations of surface crack propagation show that more intensive fractures will be induced as the maximum confining stress increases, whereas the opposite occurs for an increase of minimum confining stress. An observation of the middle section, cracks and chips shows that as the maximum confining stress increases, chips tend to form in deeper parts when the minimum confining stress is fixed, whereas they tend to formed in shallower parts as the minimum confining stress increases when the maximum confining stress is fixed.

  2. Hydraulic fracture conductivity: effects of rod-shaped proppant from lattice-Boltzmann simulations and lab tests

    Science.gov (United States)

    Osiptsov, Andrei A.

    2017-06-01

    The goal of this study is to evaluate the conductivity of random close packings of non-spherical, rod-shaped proppant particles under the closure stress using numerical simulation and lab tests, with application to the conductivity of hydraulic fractures created in subterranean formation to stimulate production from oil and gas reservoirs. Numerical simulations of a steady viscous flow through proppant packs are carried out using the lattice Boltzmann method for the Darcy flow regime. The particle packings were generated numerically using the sequential deposition method. The simulations are conducted for packings of spheres, ellipsoids, cylinders, and mixtures of spheres with cylinders at various volumetric concentrations. It is demonstrated that cylinders provide the highest permeability among the proppants studied. The dependence of the nondimensional permeability (scaled by the equivalent particle radius squared) on porosity obtained numerically is well approximated by the power-law function: K /Rv2 = 0.204ϕ4.58 in a wide range of porosity: 0.3 ≤ ϕ ≤ 0.7. Lattice-Boltzmann simulations are cross-verified against finite-volume simulations using Navier-Stokes equations for inertial flow regime. Correlations for the normalized beta-factor as a function of porosity and normalized permeability are presented as well. These formulae are in a good agreement with the experimental measurements (including packings of rod-shaped particles) and existing laboratory data, available in the porosity range 0.3 ≤ ϕ ≤ 0.5. Comparison with correlations by other authors is also given.

  3. Stress analysis of the tokamak engineering test breeder blanket

    International Nuclear Information System (INIS)

    Huang Zhongqi

    1992-01-01

    The design features of the hybrid reactor blanket and main parameters are presented. The stress analysis is performed by using computer codes SAP5p and SAP6 with the three kinds of blanket module loadings, i.e, the pressure of coolant, the blanket weight and the thermal loading. Numerical calculation results indicate that the stresses of the blanket are smaller than the allowable ones of the material, the blanket design is therefore reasonable

  4. Estimation of In Situ Stress and Permeability from an Extended Leak-off Test

    Science.gov (United States)

    Nghiep Quach, Quoc; Jo, Yeonguk; Chang, Chandong; Song, Insun

    2016-04-01

    Among many parameters needed to analyze a variety of geomechanical problems related to subsurface CO2 storage projects, two important ones are in situ stress states and permeability of the storage reservoirs and cap rocks. In situ stress is needed for investigating potential risk of fault slip in the reservoir systems and permeability is needed for assessing reservoir flow characteristics and sealing capability of cap rocks. We used an extended leak-off test (XLOT), which is often routinely conducted to assess borehole/casing integrity as well as fracture gradient, to estimate both in situ least principal stress magnitude and in situ permeability in a CO2 storage test site, offshore southeast Korea. The XLOT was conducted at a casing shoe depth (700 m below seafloor) within the cap rock consisting of mudstone, approximately 50 m above the interface between cap rock and storage reservoir. The test depth was cement-grouted and remained for 4 days for curing. Then the hole was further drilled below the casing shoe to create a 4 m open-hole interval at the bottom. Water was injected using hydraulic pump at an approximately constant flowrate into the bottom interval through the casing, during which pressure and flowrate were recorded continuously at the surface. The interval pressure (P) was increased linearly with time (t) as water was injected. At some point, the slope of P-t curve deviated from the linear trend, which indicates leak-off. Pressure reached its peak upon formation breakdown, followed by a gradual pressure decrease. Soon after the formation breakdown, the hole was shut-in by pump shut-off, from which we determined the instantaneous shut-in pressure (ISIP). The ISIP was taken to be the magnitude of the in situ least principal stress (S3), which was determined to be 12.1 MPa. This value is lower than the lithostatic vertical stress, indicating that the S3 is the least horizontal principal stress. The determined S3 magnitude will be used to characterize the

  5. The effects of honey and vitamin E administration on apoptosis in testes of rat exposed to noise stress

    Directory of Open Access Journals (Sweden)

    Masoud Hemadi

    2013-01-01

    Full Text Available Aims: A variety of stress factors are known to inhibit male reproductive functions. So this study was conducted in order to investigate the effects of honey and vitamin E on the germinative and somatic cells of testes of rats exposed to noise stress. Materials and Methods: Mature male wistar rats (n0 = 24 were randomly grouped as follows: Group 1 (honey + noise stress, 2 (vitamin E + noise stress, 3 (noise stress, and 4 as the control group. In groups 1, 2, and 3, rats were exposed to noise stress. In groups 1 and 2, rats also were given honey and vitamin E, respectively, orally for 50 days. After that, the germinative and somatic cells of testes parenchyma were isolated by digesting the whole testes by a standard method. Next, viability, apoptosis, and necrosis of the cells were evaluated by TUNEL kit and flow cytometry. Results: The rates of apoptosis and necrosis of the testicular cells were increased (P = 0.003 and P = 0.001, respectively, but viability of these cells decreased in testes of rats exposed to noise stress (P = 0.003. However, administration of honey and vitamin E were significantly helpful in keeping the cells of testis parenchyma alive, which suffers from noise pollution (P < 0.05 and P < 0.05, respectively. Conclusions: Noise stress has negative influences on the cells of testicular tissue by increasing apoptotic and necrotic cells. However, the associated enhancement in healthy cells suggests that honey and vitamin E have positive influences on the testis parenchyma.

  6. EU stresstest national report of Germany. Implementation of the EU stress tests in Germany

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The European Council concluded in March 2011 that the safety of all EU nuclear plants should be reviewed on the basis of a comprehensive and transparent risk assessment (''stress test''). In addition to the European initiative, all countries with operating nuclear power plants indicated the performance of immediate safety reviews to take into account any lessons already learned or to be learned from the Fukushima Dai-ichi accident of 11{sup th} March 2011. The German Bundestag (Federal Parliament) called upon the German Federal Government on 17{sup th} March 2011 to conduct a comprehensive review of the safety requirements for the German nuclear power plants. The competent Federal Ministry asked its advisory body, the RSK, to perform this review. The findings of the RSK safety review were presented to the public on 17{sup th} May 2011. For the European stress tests, ENSREG published the scope and modalities for comprehensive risk and safety assessments of EU nuclear power plants on 13{sup th} May 2011. This ''Declaration of ENSREG'' determines the concept, methodology and time schedule of the EU stress test. Detailed requirements on content and structure of the reports and the planned peer reviews in 2012 were developed under the leadership of ENREG and agreed at its meeting on 11{sup th} October 2011. The BMU as the federal regulator in Germany asked the Laender nuclear regulatory authorities to initiate the EU stress tests according to the ENSREG Declaration. A joint meeting of BMU, Laender authorities, expert organisations and the licensees of the German nuclear power plants took place on 30{sup th} June 2011 to agree on the scope and the procedure of stress tests in Germany. It was also decided to take the 30{sup th} June 2011 as the reference date for the plants in operation, regardless future decisions on the possible limitation of the operating time by amendment to the Atomic Energy Act which were in the legislative

  7. EU stresstest national report of Germany. Implementation of the EU stress tests in Germany

    International Nuclear Information System (INIS)

    2011-01-01

    The European Council concluded in March 2011 that the safety of all EU nuclear plants should be reviewed on the basis of a comprehensive and transparent risk assessment (''stress test''). In addition to the European initiative, all countries with operating nuclear power plants indicated the performance of immediate safety reviews to take into account any lessons already learned or to be learned from the Fukushima Dai-ichi accident of 11 th March 2011. The German Bundestag (Federal Parliament) called upon the German Federal Government on 17 th March 2011 to conduct a comprehensive review of the safety requirements for the German nuclear power plants. The competent Federal Ministry asked its advisory body, the RSK, to perform this review. The findings of the RSK safety review were presented to the public on 17 th May 2011. For the European stress tests, ENSREG published the scope and modalities for comprehensive risk and safety assessments of EU nuclear power plants on 13 th May 2011. This ''Declaration of ENSREG'' determines the concept, methodology and time schedule of the EU stress test. Detailed requirements on content and structure of the reports and the planned peer reviews in 2012 were developed under the leadership of ENREG and agreed at its meeting on 11 th October 2011. The BMU as the federal regulator in Germany asked the Laender nuclear regulatory authorities to initiate the EU stress tests according to the ENSREG Declaration. A joint meeting of BMU, Laender authorities, expert organisations and the licensees of the German nuclear power plants took place on 30 th June 2011 to agree on the scope and the procedure of stress tests in Germany. It was also decided to take the 30 th June 2011 as the reference date for the plants in operation, regardless future decisions on the possible limitation of the operating time by amendment to the Atomic Energy Act which were in the legislative procedure at that time. The ''stress tests'' were started by all German

  8. The Influence of Test-Based Accountability Policies on Early Elementary Teachers: School Climate, Environmental Stress, and Teacher Stress

    Science.gov (United States)

    Saeki, Elina; Segool, Natasha; Pendergast, Laura; von der Embse, Nathaniel

    2018-01-01

    This study examined the potential influence of test-based accountability policies on school environment and teacher stress among early elementary teachers. Structural equation modeling of data from 541 kindergarten through second grade teachers across three states found that use of student performance on high-stakes tests to evaluate teachers…

  9. Standard practice for preparation and use of Bent-Beam stress-corrosion test specimens

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2011-01-01

    1.1 This practice covers procedures for designing, preparing, and using bent-beam stress-corrosion specimens. 1.2 Different specimen configurations are given for use with different product forms, such as sheet or plate. This practice applicable to specimens of any metal that are stressed to levels less than the elastic limit of the material, and therefore, the applied stress can be accurately calculated or measured (see Note 1). Stress calculations by this practice are not applicable to plastically stressed specimens. Note 1—It is the nature of these practices that only the applied stress can be calculated. Since stress-corrosion cracking is a function of the total stress, for critical applications and proper interpretation of results, the residual stress (before applying external stress) or the total elastic stress (after applying external stress) should be determined by appropriate nondestructive methods, such as X-ray diffraction (1). 1.3 Test procedures are given for stress-corrosion testing by ex...

  10. Cornea stress test--evaluation of corneal endothelial function in vivo by contact lens induced stress

    Directory of Open Access Journals (Sweden)

    Saini Jagjit

    1997-01-01

    Full Text Available Reliable and valid assessment of corneal endothelial function is a critical input for diagnosing, prognosticating and monitoring progression of disorders affecting corneal endothelium. In 123 eyes, corneal endothelial function was assessed employing data from the corneal hydration recovery dynamics. Serial pachometric readings were recorded on Haag-Striet pachometer with Mishima-Hedbys modification before and after two hours of thick soft contact lens wear. Percentage Recovery Per Hour (PRPH was derived from raw data as an index of endothelial function. Assessed PRPH in pseudophakic corneal oedema and Fuchs′ endothelial dystrophy eyes (35.9 +/- 9.8% was significantly lower than normal controls (61.9 +/- 10.5%. On employing receiver operation characteristics curve analysis the tested results demonstrated high sensitivity (87% and specificity (92% for detection of low endothelial function at PRPH cut off of 47.5%. Using this PRPH cut off, 80% of Fuchs′ endothelial dystrophy and 93.3% of pseudophakic corneal oedema eyes could be demonstrated to have low endothelial function. A total of 66.7% of diabetic eyes also demonstrated PRPH of lower than 47.5%. Clear corneal grafts demonstrated PRPH values of 24.6% to 73.0%. Of 6 corneal grafts that demonstrated initial PRPH of lower than 47.5%, 4 failed within 4 to 6 months. Our data demonstrated high sensitivity and specificity of this corneal stress test. PRPH index was useful in quantifying endothelial function in clinical disorders including diabetes mellitus. The index PRPH was demonstrated to be useful in monitoring and prognosticating outcome of corneal grafts.

  11. Stress corrosion evaluation of powder metallurgy aluminum alloy 7091 with the breaking load test method

    Science.gov (United States)

    Domack, Marcia S.

    1987-01-01

    The stress corrosion behavior of the P/M aluminum alloy 7091 is evaluated in two overaged heat treatment conditions, T7E69 and T7E70, using an accelerated test technique known as the breaking load test method. The breaking load data obtained in this study indicate that P/M 7091 alloy is highly resistant to stress corrosion in both longitudinal and transverse orientations at stress levels up to 90 percent of the material yield strength. The reduction in mean breaking stress as a result of corrosive attack is smallest for the more overaged T7E70 condition. Details of the test procedure are included.

  12. Influence of leaf vein density and thickness on hydraulic conductance and photosynthesis in rice (Oryza sativa L.) during water stress.

    Science.gov (United States)

    Tabassum, Muhammad Adnan; Zhu, Guanglong; Hafeez, Abdul; Wahid, Muhammad Atif; Shaban, Muhammad; Li, Yong

    2016-11-16

    The leaf venation architecture is an ideal, highly structured and efficient irrigation system in plant leaves. Leaf vein density (LVD) and vein thickness are the two major properties of this system. Leaf laminae carry out photosynthesis to harvest the maximum biological yield. It is still unknown whether the LVD and/or leaf vein thickness determines the plant hydraulic conductance (K plant ) and leaf photosynthetic rate (A). To investigate this topic, the current study was conducted with two varieties under three PEG-induced water deficit stress (PEG-IWDS) levels. The results showed that PEG-IWDS significantly decreased A, stomatal conductance (g s ), and K plant in both cultivars, though the IR-64 strain showed more severe decreases than the Hanyou-3 strain. PEG-IWDS significantly decreased the major vein thickness, while it had no significant effect on LVD. A, g s and K plant were positively correlated with each other, and they were negatively correlated with LVD. A, g s and K plant were positively correlated with the inter-vein distance and major vein thickness. Therefore, the decreased photosynthesis and hydraulic conductance in rice plants under water deficit conditions are related to the decrease in the major vein thickness.

  13. Studies on laws of stress-magnetization based on magnetic memory testing technique

    Science.gov (United States)

    Ren, Shangkun; Ren, Xianzhi

    2018-03-01

    Metal magnetic memory (MMM) testing technique is a novel testing method which can early test stress concentration status of ferromagnetic components. Under the different maximum tensile stress, the relationship between the leakage magnetic field of at certain point of cold rolled steel specimen and the tensile stress was measured during the process of loading and unloading by repeated. It shows that when the maximum tensile stress is less than 610 MPa, the relationship between the magnetic induction intensity and the stress is linear; When the maximum tensile stress increase from 610 MPa to 653 MPa of yield point, the relationship between the magnetic induction intensity and the tensile becomes bending line. The location of the extreme point of the bending line will move rapidly from the position of smaller stress to the larger stress position, and the variation of magnetic induction intensity increases rapidly. When the maximum tensile stress is greater than the 653 MPa of yield point, the variation of the magnetic induction intensity remains large, and the position of the extreme point moves very little. In theoretical aspects, tensile stress is to be divided into ordered stress and disordered stress. In the stage of elastic stress, a microscopic model of the order stress magnetization is established, and the conclusions are in good agreement with the experimental data. In the plastic deformation stage, a microscopic model of disordered stress magnetization is established, and the conclusions are in good agreement with the experimental data, too. The research results can provide reference for the accurate quantitative detection and evaluation of metal magnetic memory testing technology.

  14. 12 CFR 652.100 - Audit of the risk-based capital stress test.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Audit of the risk-based capital stress test... AGRICULTURAL MORTGAGE CORPORATION FUNDING AND FISCAL AFFAIRS Risk-Based Capital Requirements § 652.100 Audit of the risk-based capital stress test. You must have a qualified, independent external auditor review...

  15. Bending fatigue tests on SiC-Al tapes under alternating stress at room temperature

    Science.gov (United States)

    Herzog, J. A.

    1981-01-01

    The development of a testing method for fatigue tests on SiC-Al tapes containing a small amount of SiC filaments under alternating stress is reported. The fatigue strength curves resulting for this composite are discussed. They permit an estimate of its behavior under continuous stress and in combination with various other matrices, especially metal matrices.

  16. Summary report - development of laboratory tests and the stress- strain behaviour of Olkiluoto mica gneiss

    Energy Technology Data Exchange (ETDEWEB)

    Hakala, M.; Heikkilae, E. [Helsinki Univ. of Technology, Espoo (Finland). Lab. of Rock Engineering

    1997-05-01

    This work summarizes the project aimed at developing and qualifying a suitable combination of laboratory tests to establish a statistically reliable stress-strain behaviour of the main rock types at Posiva Oy`s detailed investigation sites for disposal of spent nuclear fuel. The work includes literature study of stress-strain behaviour of brittle rock, development and qualification of laboratory tests, suggested test procedures and interpretation methods and finally testing of Olkiluoto mica gneiss. The Olkiluoto study includes over 130 loading tests. Besides the commonly used laboratory tests, direct tensile tests, damage controlled tests and acoustic emission measurements were also carried out. (orig.) (54 refs.).

  17. Summary report - development of laboratory tests and the stress- strain behaviour of Olkiluoto mica gneiss

    International Nuclear Information System (INIS)

    Hakala, M.; Heikkilae, E.

    1997-05-01

    This work summarizes the project aimed at developing and qualifying a suitable combination of laboratory tests to establish a statistically reliable stress-strain behaviour of the main rock types at Posiva Oy's detailed investigation sites for disposal of spent nuclear fuel. The work includes literature study of stress-strain behaviour of brittle rock, development and qualification of laboratory tests, suggested test procedures and interpretation methods and finally testing of Olkiluoto mica gneiss. The Olkiluoto study includes over 130 loading tests. Besides the commonly used laboratory tests, direct tensile tests, damage controlled tests and acoustic emission measurements were also carried out. (orig.) (54 refs.)

  18. Progress and Challenges of Ultrasonic Testing for Stress in Remanufacturing Laser Cladding Coating

    Directory of Open Access Journals (Sweden)

    Xiao-Ling Yan

    2018-02-01

    Full Text Available Stress in laser cladding coating is an important factor affecting the safe operation of remanufacturing components. Ultrasonic testing has become a popular approach in the nondestructive evaluation of stress, because it has the advantages of safety, nondestructiveness, and online detection. This paper provides a review of ultrasonic testing for stress in remanufacturing laser cladding coating. It summarizes the recent research outcomes on ultrasonic testing for stress, and analyzes the mechanism of ultrasonic testing for stress. Remanufacturing laser cladding coating shows typical anisotropic behaviors. The ultrasonic testing signal in laser cladding coating is influenced by many complex factors, such as microstructure, defect, temperature, and surface roughness, among others. At present, ultrasonic testing for stress in laser cladding coating can only be done roughly. This paper discusses the active mechanism of micro/macro factors in the reliability of stress measurement, as well as the impact of stress measurement on the quality and safety of remanufacturing components. Based on the discussion, this paper proposes strategies to nondestructively, rapidly, and accurately measure stress in remanufacturing laser cladding coating.

  19. Does Stress Result in You Exercising Less? Or Does Exercising Result in You Being Less Stressed? Or Is It Both? Testing the Bi-directional Stress-Exercise Association at the Group and Person (N of 1) Level.

    Science.gov (United States)

    Burg, Matthew M; Schwartz, Joseph E; Kronish, Ian M; Diaz, Keith M; Alcantara, Carmela; Duer-Hefele, Joan; Davidson, Karina W

    2017-12-01

    Psychosocial stress contributes to heart disease in part by adversely affecting maintenance of health behaviors, while exercise can reduce stress. Assessing the bi-directional relationship between stress and exercise has been limited by lack of real-time data and theoretical and statistical models. This lack may hinder efforts to promote exercise maintenance. We test the bi-directional relationship between stress and exercise using real-time data for the average person and the variability-individual differences-in this relationship. An observational study was conducted within a single cohort randomized controlled experiment. Healthy young adults, (n = 79) who reported only intermittent exercise, completed 12 months of stress monitoring by ecological momentary assessment (at the beginning of, end of, and during the day) and continuous activity monitoring by Fitbit. A random coefficients linear mixed model was used to predict end-of-day stress from the occurrence/non-occurrence of exercise that day; a logistic mixed model was used to predict the occurrence/non-occurrence of exercise from ratings of anticipated stress. Separate regression analyses were also performed for each participant. Sensitivity analysis tested all models, restricted to the first 180 days of observation (prior to randomization). We found a significant average inverse (i.e., negative) effect of exercise on stress and of stress on exercise. There was significant between-person variability. Of N = 69, exercise was associated with a stress reduction for 15, a stress increase for 2, and no change for the remainder. We also found that an increase in anticipated stress reported the previous night or that morning was associated with a significant 20-22% decrease (OR = 0.78-0.80) in the odds of exercising that day. Of N = 69, this increase in stress reduced the likelihood of exercise for 17, increased the odds for 1, and had no effect for the remainder. We were unable to identify psychosocial

  20. Preparation, Conduct and Evaluation of Exercises to Test Preparedness for a Nuclear or Radiological Emergency

    International Nuclear Information System (INIS)

    2010-01-01

    The aim of this publication is to serve as a practical tool for the preparation, conduct and evaluation of exercises to test preparedness for response to a nuclear or radiological emergency. It fulfils in part the functions assigned to the IAEA under Article 5.a(ii) of the Convention on Assistance in Case of a Nuclear Accident or Radiological Emergency (Assistance Convention), namely, to collect and disseminate to States Parties and Member States information concerning the methodologies, techniques and available results of research on such emergencies. To ensure effective response to radiation emergencies when needed, provisions should be made for regular training of emergency response personnel. As stated in Preparedness and Response for a Nuclear or Radiological Emergency (Safety Requirements, Safety Standard Series No. GS-R-2), 'The operator and the response organizations shall make arrangements for the selection of personnel and training to ensure that the personnel have the requisite knowledge, skills, abilities, equipment, procedures and other arrangements to perform their assigned response functions'. A further requirement is that 'Exercise programmes shall be conducted to ensure that all specified functions required to be performed for emergency response and all organizational interfaces for facilities in threat category I, II or III and the national level programmes for threat category IV or V are tested at suitable intervals'. In 2004 the IAEA General Conference, in resolution GC(48)/RES/10 encouraged Member States to 'implement the Safety Requirements for Preparedness and Response to a Nuclear or Radiological Emergency'. This document is published as part of the IAEA Emergency Preparedness and Response Series to assist in meeting these requirements and to fulfil Article 5 of the Assistance Convention. It was developed based on a number of assumptions about national and local capabilities. Therefore, the exercise structure, terms and scenarios must be

  1. [Unpredictable chronic mild stress effects on antidepressants activities in forced swim test].

    Science.gov (United States)

    Kudryashov, N V; Kalinina, T S; Voronina, T A

    2015-02-01

    The experiments has been designed to study unpredictable chronic mild stress effect on anti-depressive activities of amitriptyline (10 mg/kg) and fluoxetine (20 mg/kg) in forced swim test in male outbred mice. It is shown that acute treatment with fluoxetine does not produce any antidepressant effects in mice following stress of 14 days while the sub-chronic injections of fluoxetine result in more deep depressive-like behavior. In 28 daily stressed mice, antidepressant effect of fluoxetine is observed independently of the injection rates. Amitriptyline demonstrates the antidepressant activity regardless of the duration of stress or administration scheduling, but at the same time the severity of anti-immobilization effect of amitriptyline in stressed mice is weaker in compare to non-stressed trails. Thus, the injection rates and duration of unpredictable mild chronic stress are the parameters that determine the efficiency of antidepressants in the mouse forced swimming test.

  2. The Validity of Graduate Management Admission Test Scores: A Summary of Studies Conducted from 1997 to 2004

    Science.gov (United States)

    Talento-Miller, Eileen; Rudner, Lawrence M.

    2008-01-01

    The validity of Graduate Management Admission Test (GMAT) scores is examined by summarizing 273 studies conducted between 1997 and 2004. Each of the studies was conducted through the Validity Study Service of the test sponsor and contained identical variables and statistical methods. Validity coefficients from each of the studies were corrected…

  3. The Influence of Cardiac Risk Factor Burden on Cardiac Stress Test Outcomes.

    Science.gov (United States)

    Schrock, Jon W; Li, Morgan; Orazulike, Chidubem; Emerman, Charles L

    2011-06-01

    Chest pain is the most common admission diagnosis for observation unit patients. These patients often undergo cardiac stress testing to further risk stratify for coronary artery disease (CAD). The decision of whom to stress is currently based on clinical judgment. We sought to determine the influence of cardiac risk factor burden on cardiac stress test outcome for patients tested from an observation unit, inpatient or outpatient setting. We performed a retrospective observational cohort study for all patients undergoing stress testing in our institution from June 2006 through July 2007. Cardiac risk factors were collected at the time of stress testing. Risk factors were evaluated in a summative fashion using multivariate regression adjusting for age and known coronary artery disease. The model was tested for goodness of fit and collinearity and the c statistic was calculated using the receiver operating curve. A total of 4026 subjects were included for analysis of which 22% had known CAD. The rates of positive outcome were 89 (12.0%), 95 (12.6%), and 343 (16.9%) for the OU, outpatients, and hospitalized patients respectively. While the odds of a positive test outcome increased for additional cardiac risk factors, ROC curve analysis indicates that simply adding the number of risk factors does not add significant diagnostic value. Hospitalized patients were more likely to have a positive stress test, OR 1.41 (1.10 - 1.81). Our study does not support basing the decision to perform a stress test on the number of cardiac risk factors.

  4. The role of anxiety in cortisol stress response and cortisol recovery in boys with oppositional defiant disorder/conduct disorder

    NARCIS (Netherlands)

    Schoorl, Jantiene; van Rijn, S.; de Wied, M.; van Goozen, S.H.M.; Swaab, Hanna

    2016-01-01

    Children with antisocial and aggressive behaviors have been found to show abnormal neurobiological responses to stress, specifically impaired cortisol stress reactivity. The role of individual characteristics, such as comorbid anxiety, in the stress response is far less studied. Furthermore, this

  5. 78 FR 59219 - Stress Testing of Regulated Entities

    Science.gov (United States)

    2013-09-26

    ... institutions. C. Methodologies The Banks requested that Sec. 1238.4 of the rule expressly state that the stress... the scenarios provided by FHFA. FHFA will clarify questions about materiality and about which... its regulated financial institutions. Methodologies and Practices--Sec. 1238.4 Section 1238.4 provides...

  6. Low mercury concentration produces vasoconstriction, decreases nitric oxide bioavailability and increases oxidative stress in rat conductance artery.

    Directory of Open Access Journals (Sweden)

    Núbia Belem Lemos

    Full Text Available Mercury is an environmental pollutant that reduces nitric oxide (NO bioavailability and increases oxidative stress, having a close link with cardiovascular diseases, as carotid atherosclerosis, myocardial infarction, coronary heart disease and hypertension. One of the main sites affected by oxidative stress, which develops atherosclerosis, is the aorta. Under acute exposure to low mercury concentrations reactive oxygen species (ROS production were only reported for resistance vessels but if low concentrations of mercury also affect conductance arteries it is still unclear. We investigated the acute effects of 6 nM HgCl(2 on endothelial function of aortic rings measuring the reactivity to phenylephrine in rings incubated, or not, with HgCl(2 for 45 min, the protein expression for cyclooxygenase 2 (COX-2 and the AT1 receptor. HgCl(2 increased Rmax and pD2 to phenylephrine without changing the vasorelaxation induced by acetylcholine and sodium nitroprusside. Endothelial damage abolished the increased reactivity to phenylephrine. The increase of Rmax and pD2 produced by L-NAME was smaller in the presence of HgCl(2. Enalapril, losartan, indomethacin, furegrelate, the selective COX-2 inhibitor NS 398, superoxide dismutase and the NADPH oxidase inhibitor apocynin reverted HgCl(2 effects on the reactivity to phenylephrine, COX-2 protein expression was increased, and AT1 expression reduced. At low concentration, below the reference values, HgCl(2 increased vasoconstrictor activity by reducing NO bioavailability due to increased ROS production by NADPH oxidase activity. Results suggest that this is due to local release of angiotensin II and prostanoid vasoconstrictors. Results also suggest that acute low concentration mercury exposure, occurring time to time could induce vascular injury due to endothelial oxidative stress and contributing to increase peripheral resistance, being a high risk factor for public health.

  7. Depressive symptoms and perceived chronic stress predict test anxiety in nursing students

    Directory of Open Access Journals (Sweden)

    Christoph Augner

    2015-09-01

    Full Text Available Aim: The aim of this study is to identify predictors of test anxiety in nursing students. Design: Cross sectional pilot study. Methods: A questionnaire was administered to 112 students of an Austrian nursing school (mean age = 21.42, SD = 5.21. Test anxiety (measured by the standardized PAF Test Anxiety Questionnaire, perceived chronic stress, depressive symptoms, pathological eating and further psychological and health parameters were measured. Results: We found highly significant correlations between test anxiety and working hours (0.25, depression score (0.52, emotional stability (-0.31, and perceived chronic stress (0.65 (p < 0.01, for all. Regression analysis revealed chronic stress and emotional instability as best predictors for test anxiety. Furthermore, path analysis revealed that past negative academic performance outcomes contribute to test anxiety via depressive symptoms and perceived chronic stress. Conclusion: Depressive symptoms and perceived chronic stress are strongly related to test anxiety. Therefore therapy and training methods that address depressive symptoms and perceived chronic stress, and thereby aim to modify appraisal of potential stressful situations, may be successful in addressing test anxiety.

  8. Facility-level association of preoperative stress testing and postoperative adverse cardiac events.

    Science.gov (United States)

    Valle, Javier A; Graham, Laura; Thiruvoipati, Thejasvi; Grunwald, Gary; Armstrong, Ehrin J; Maddox, Thomas M; Hawn, Mary T; Bradley, Steven M

    2018-06-22

    Despite limited indications, preoperative stress testing is often used prior to non-cardiac surgery. Patient-level analyses of stress testing and outcomes are limited by case mix and selection bias. Therefore, we sought to describe facility-level rates of preoperative stress testing for non-cardiac surgery, and to determine the association between facility-level preoperative stress testing and postoperative major adverse cardiac events (MACE). We identified patients undergoing non-cardiac surgery within 2 years of percutaneous coronary intervention in the Veterans Affairs (VA) Health Care System, from 2004 to 2011, facility-level rates of preoperative stress testing and postoperative MACE (death, myocardial infarction (MI) or revascularisation within 30 days). We determined risk-standardised facility-level rates of stress testing and postoperative MACE, and the relationship between facility-level preoperative stress testing and postoperative MACE. Among 29 937 patients undergoing non-cardiac surgery at 131 VA facilities, the median facility rate of preoperative stress testing was 13.2% (IQR 9.7%-15.9%; range 6.0%-21.5%), and 30-day postoperative MACE was 4.0% (IQR 2.4%-5.4%). After risk standardisation, the median facility-level rate of stress testing was 12.7% (IQR 8.4%-17.4%) and postoperative MACE was 3.8% (IQR 2.3%-5.6%). There was no correlation between risk-standardised stress testing and composite MACE at the facility level (r=0.022, p=0.81), or with individual outcomes of death, MI or revascularisation. In a national cohort of veterans undergoing non-cardiac surgery, we observed substantial variation in facility-level rates of preoperative stress testing. Facilities with higher rates of preoperative stress testing were not associated with better postoperative outcomes. These findings suggest an opportunity to reduce variation in preoperative stress testing without sacrificing patient outcomes. © Article author(s) (or their employer(s) unless otherwise

  9. Psychophysiologic testing for post-traumatic stress disorder: forensic psychiatric application.

    Science.gov (United States)

    Pitman, R K; Orr, S P

    1993-01-01

    The validity of the post-traumatic stress disorder (PTSD) diagnosis is limited by both the illusory objectivity of the traumatic event and the subjectivity of the ensuing syndrome. These limitations are especially problematic in the forensic setting. Psychophysiologic measurements may strengthen PTSD's forensic value by offering a more objective assessment technique for cases that find their way into the courtroom. Based upon the results of published research studies conducted in a range of military and civilian, PTSD and non-PTSD subjects, psychophysiologic data can provide evidence helping to establish or refute the presence of the DSM-III-R PTSD arousal criteria, as well as aid psychiatric experts in estimating the probability of the disorder's presence in a given claimant. Psychophysiologic testing should be viewed as one component of a multimethod forensic psychiatric evaluation for PTSD. It is likely that it will soon be offered and, given current legal standards, admitted as evidence in civil and criminal litigation.

  10. Standard test method for determining residual stresses by the hole-drilling strain-gage method

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 Residual Stress Determination: 1.1.1 This test method specifies a hole-drilling procedure for determining residual stress profiles near the surface of an isotropic linearly elastic material. The test method is applicable to residual stress profile determinations where in-plane stress gradients are small. The stresses may remain approximately constant with depth (“uniform” stresses) or they may vary significantly with depth (“non-uniform” stresses). The measured workpiece may be “thin” with thickness much less than the diameter of the drilled hole or “thick” with thickness much greater than the diameter of the drilled hole. Only uniform stress measurements are specified for thin workpieces, while both uniform and non-uniform stress measurements are specified for thick workpieces. 1.2 Stress Measurement Range: 1.2.1 The hole-drilling method can identify in-plane residual stresses near the measured surface of the workpiece material. The method gives localized measurements that indicate the...

  11. Non-Destructive Testing: Sample Questions for Conduct of Examinations at Levels 1 and 2

    International Nuclear Information System (INIS)

    2010-01-01

    The International Atomic Energy Agency (IAEA) supports industrial applications of radiation technology which include non-destructive testing (NDT) under its various programmes such as individual country Technical Co-operation (TC) projects, Regional Projects and Coordinated Research Projects (CRPs). NDT technology is essentially needed for the improvement of the quality of industrial products, equipment and plants all over the world, especially in developing Member States. Trained and certified personnel is one of the essential requirements for applying this technology in industry. With this in view, the IAEA first played an important role in cooperation with the International Organisation for Standardisation (ISO) for the development of a standard for training and certification of NDT personnel, namely ISO 9712, 'Non-Destructive Testing: Qualification and Certification of Personnel'. Subsequently the syllabi and needed training materials were identified and developed for the creation of, in each of the Member States, a core group of personnel who are trained and qualified to establish the training and certification process in their respective countries. One of the important requirements for such a process is to have the examination questions for conducting the certification examinations. A need had been felt to compile the appropriate questions firstly for conducting these examinations at the national and regional levels and secondly to provide these to the certification bodies of the Member States so that they could initiate their own level 1 and 2 certification examinations. For this purpose, Experts' Task Force Meetings were convened first in Accra, Ghana and then in Vienna, Austria under the AFRA regional projects on NDT. The experts examined and discussed in detail the ISO 9712 (1999 and 2005 versions) requirements for general, specific and practical examinations for level 1 and 2 personnel. After that a set of questions has been established which are

  12. Experimental stress analysis and fatigue tests of five 12-in. NPS ANSI Standard B16.9 tees

    International Nuclear Information System (INIS)

    Moore, S.E.; Grigory, S.C.; Weed, R.A.

    1984-04-01

    The tees, designated as ORNL tees T-4, T-6, T-7, T-8, and T-15, were tested under subcontract at Southwest Research Institute, and the data were analyzed at ORNL. Experimental stress analyses were conducted for 13 individual loadings on each tee, including internal pressure and 3 mutually perpendicular force and moment loads on the branch and on the run. Each test model was instrumented with approx. 220, 1/16-in. three-gage, 45 0 strain rosettes on the body of the tee, and approx. 10, 1/16-in. two-gage, strain rosettes on the pipe extensions. Dial indicators, mounted on a special nonflexible holding frame, were used to measure deflections and rotations of the pipe extensions. Normalized maximum stress intensities for each loading condition on each tee are summarized in the text. Complete sets of strain-gage data, normalized stresses, and displacement measurements for each tee are given on microfiche in the appendixes. Following completion of the strain-gage tests, each tee was tested to failure in a fully reversed displacement-controlled low-cycle fatigue test with an alternating transverse load applied to the branch pipe. The load was directed out of plane for T-4, T-6, T-8, and T-15; and in plane for T-7. A constant internal pressure equal to the nominal design pressure was maintained during the fatigue tests. Failure data from the fatigue tests are summarized in the text

  13. Optimal design of constant-stress accelerated degradation tests using the M-optimality criterion

    International Nuclear Information System (INIS)

    Wang, Han; Zhao, Yu; Ma, Xiaobing; Wang, Hongyu

    2017-01-01

    In this paper, we propose the M-optimality criterion for designing constant-stress accelerated degradation tests (ADTs). The newly proposed criterion concentrates on the degradation mechanism equivalence rather than evaluation precision or prediction accuracy which is usually considered in traditional optimization criteria. Subject to the constraints of total sample number, test termination time as well as the stress region, an optimum constant-stress ADT plan is derived by determining the combination of stress levels and the number of samples allocated to each stress level, when the degradation path comes from inverse Gaussian (IG) process model with covariates and random effects. A numerical example is presented to verify the robustness of our proposed optimum plan and compare its efficiency with other test plans. Results show that, with a slightly relaxed requirement of evaluation precision and prediction accuracy, our proposed optimum plan reduces the dispersion of the estimated acceleration factor between the usage stress level and a higher accelerated stress level, which makes an important contribution to reliability demonstration and assessment tests. - Highlights: • We establish the necessary conditions for degradation mechanism equivalence of ADTs. • We propose the M-optimality criterion for designing constant-stress ADT plans. • The M-optimality plan reduces the dispersion of the estimated accelerated factors. • An electrical connector with its stress relaxation data is used for illustration.

  14. Stress transfer in microdroplet tensile test: PVC-coated and uncoated Kevlar-29 single fiber

    Science.gov (United States)

    Zhenkun, Lei; Quan, Wang; Yilan, Kang; Wei, Qiu; Xuemin, Pan

    2010-11-01

    The single fiber/microdroplet tensile test is applied for evaluating the interfacial mechanics between a fiber and a resin substrate. It is used to investigate the influence of a polymer coating on a Kevlar-29 fiber surface, specifically the stress transfer between the fiber and epoxy resin in a microdroplet. Unlike usual tests, this new test ensures a symmetrical axial stress on the embedded fiber and reduces the stress singularity that appears at the embedded fiber entry. Using a homemade loading device, symmetrical tensile tests are performed on a Kevlar-29 fiber with or without polyvinylchloride (PVC) coating, the surface of which is in contact with two epoxy resin microdroplets during curing. Raman spectra on the embedded fiber are recorded by micro-Raman Spectroscopy under different strain levels. Then they are transformed to the distributions of fiber axis stress based on the relationship between stress and Raman shift. The Raman results reveal that the fiber axial stresses increase with the applied loads, and the antisymmetric interfacial shear stresses, obtained by a straightforward balance of shear-to-axial forces argument, lead to the appearance of shear stress concentrations at a distance to the embedded fiber entry. The load is transferred from the outer fiber to the embedded fiber in the epoxy microdroplet. As is observed by scanning electronic microscopy (SEM), the existence of a flexible polymer coating on the fiber surface reduces the stress transfer efficiency.

  15. Republic of Poland; Technical Note on Stress Testing the Banking Sector

    OpenAIRE

    International Monetary Fund

    2013-01-01

    This Technical Note discusses results of stress testing of the banking sector in Poland. The Polish banking system is well capitalized and liquid, as confirmed by stress tests results. Polish banks are, in aggregate, resilient even under severe adverse scenarios. Some small banks could fail to meet minimum regulatory capital and liquidity requirements in these scenarios, but with little impact on the overall banking system. Tests showed that only small banks, together representing up to 30 pe...

  16. Nigeria; Publication of Financial Sector Assessment Program Documentation––Technical Note on Stress Testing

    OpenAIRE

    International Monetary Fund

    2013-01-01

    To assess the financial stability in Nigeria, various stress tests and analytic processes were undertaken jointly by the Nigerian authorities and the Financial Sector Assessment Program (FSAP) team. The exercise included macroeconomic scenario analysis and its transmission into a range of single- and multifactor shocks. The tests covered the entire Nigerian banking system and looked at the short-term horizon, in part because of data constraints. Sensitivity stress tests estimated the impact o...

  17. Implantable electrolyte conductance-based pressure sensing catheter, II. Device construction and testing.

    Science.gov (United States)

    Tan, Robert; Benharash, Peyman; Schulam, Peter; Schmidt, Jacob J

    2013-12-01

    Direct measurements of arterial blood pressure most commonly use bulky external instrumentation containing a pressure transducer connected to an ex vivo fluid-filled arterial line, which is subject to several sensing artifacts. In situ blood pressure sensors, typically solid state piezoresistive, capacitive, and interferometric sensors, are unaffected by these artifacts, but can be expensive to produce and miniaturize. We have developed an alternative approach to blood pressure measurement based on deformation of an elastic tube filled with electrolyte solution. Simple measurement of the electrical conductance of this solution as the tube dimensions change allows determination of the external pressure. The sensor is made from inexpensive materials and its miniaturization is straightforward. In vitro static testing of initial sensor prototypes mounted on a catheter tip showed a linear response with applied pressure and a resolution of 1 mmHg. In vivo sensing followed catheterization of the sensor into the femoral artery of a porcine model through a 7F catheter port. The sensor performed comparably to a commercial pressure transducer also connected to the catheter port. Due to its scalability and cost, this sensor has the potential for use in a range of pressure sensing applications, such as measurement of intracranial, spinal, or interstitial pressures.

  18. Testing a linear time invariant model for skin conductance responses by intraneural recording and stimulation.

    Science.gov (United States)

    Gerster, Samuel; Namer, Barbara; Elam, Mikael; Bach, Dominik R

    2018-02-01

    Skin conductance responses (SCR) are increasingly analyzed with model-based approaches that assume a linear and time-invariant (LTI) mapping from sudomotor nerve (SN) activity to observed SCR. These LTI assumptions have previously been validated indirectly, by quantifying how much variance in SCR elicited by sensory stimulation is explained under an LTI model. This approach, however, collapses sources of variability in the nervous and effector organ systems. Here, we directly focus on the SN/SCR mapping by harnessing two invasive methods. In an intraneural recording experiment, we simultaneously track SN activity and SCR. This allows assessing the SN/SCR relationship but possibly suffers from interfering activity of non-SN sympathetic fibers. In an intraneural stimulation experiment under regional anesthesia, such influences are removed. In this stimulation experiment, about 95% of SCR variance is explained under LTI assumptions when stimulation frequency is below 0.6 Hz. At higher frequencies, nonlinearities occur. In the intraneural recording experiment, explained SCR variance is lower, possibly indicating interference from non-SN fibers, but higher than in our previous indirect tests. We conclude that LTI systems may not only be a useful approximation but in fact a rather accurate description of biophysical reality in the SN/SCR system, under conditions of low baseline activity and sporadic external stimuli. Intraneural stimulation under regional anesthesia is the most sensitive method to address this question. © 2017 The Authors. Psychophysiology published by Wiley Periodicals, Inc. on behalf of Society for Psychophysiological Research.

  19. High Conduction Neutron Absorber to Simulate Fast Reactor Environment in an Existing Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Guillen, Donna; Greenwood, Lawrence R.; Parry, James

    2014-06-22

    A need was determined for a thermal neutron absorbing material that could be cooled in a gas reactor environment without using large amounts of a coolant that would thermalize the neutron flux. A new neutron absorbing material was developed that provided high conduction so a small amount of water would be sufficient for cooling thereby thermalizing the flux as little as possible. An irradiation experiment was performed to assess the effects of radiation and the performance of a new neutron absorbing material. Neutron fluence monitors were placed inside specially fabricated holders within a set of drop-in capsules and irradiated for up to four cycles in the Advanced Test Reactor. Following irradiation, the neutron fluence monitor wires were analyzed by gamma and x-ray spectrometry to determine the activities of the activation products. The adjusted neutron fluences were calculated and grouped into three bins – thermal, epithermal and fast to evaluate the spectral shift created by the new material. Fluence monitors were evaluated after four different irradiation periods to evaluate the effects of burn-up in the absorbing material. Additionally, activities of the three highest activity isotopes present in the specimens are given.

  20. The Application of Normal Stress Reduction Function in Tilt Tests for Different Block Shapes

    Science.gov (United States)

    Kim, Dong Hyun; Gratchev, Ivan; Hein, Maw; Balasubramaniam, Arumugam

    2016-08-01

    This paper focuses on the influence of the shapes of rock cores, which control the sliding or toppling behaviours in tilt tests for the estimation of rock joint roughness coefficients (JRC). When the JRC values are estimated by performing tilt tests, the values are directly proportional to the basic friction of the rock material and the applied normal stress on the sliding planes. Normal stress obviously varies with the shape of the sliding block, and the basic friction angle is also affected by the sample shapes in tilt tests. In this study, the shapes of core blocks are classified into three representative shapes and those are created using plaster. Using the various shaped artificial cores, a set of tilt tests is carried out to identify the shape influences on the normal stress and the basic friction angle in tilt tests. The test results propose a normal stress reduction function to estimate the normal stress for tilt tests according to the sample shapes based on Barton's empirical equation. The proposed normal stress reduction functions are verified by tilt tests using artificial plaster joints and real rock joint sets. The plaster joint sets are well matched and cast in detailed printed moulds using a 3D printing technique. With the application of the functions, the obtained JRC values from the tilt tests using the plaster samples and the natural rock samples are distributed within a reasonable JRC range when compared with the measured values.

  1. Physician discretion is safe and may lower stress test utilization in emergency department chest pain unit patients.

    Science.gov (United States)

    Napoli, Anthony M; Arrighi, James A; Siket, Matthew S; Gibbs, Frantz J

    2012-03-01

    Chest pain unit (CPU) observation with defined stress utilization protocols is a common management option for low-risk emergency department patients. We sought to evaluate the safety of a joint emergency medicine and cardiology staffed CPU. Prospective observational trial of consecutive patients admitted to an emergency department CPU was conducted. A standard 6-hour observation protocol was followed by cardiology consultation and stress utilization largely at their discretion. Included patients were at low/intermediate risk by the American Heart Association, had nondiagnostic electrocardiograms, and a normal initial troponin. Excluded patients were those with an acute comorbidity, age >75, and a history of coronary artery disease, or had a coexistent problem restricting 24-hour observation. Primary outcome was 30-day major adverse cardiovascular events-defined as death, nonfatal acute myocardial infarction, revascularization, or out-of-hospital cardiac arrest. A total of 1063 patients were enrolled over 8 months. The mean age of the patients was 52.8 ± 11.8 years, and 51% (95% confidence interval [CI], 48-54) were female. The mean thrombolysis in myocardial infarction and Diamond & Forrester scores were 0.6% (95% CI, 0.51-0.62) and 33% (95% CI, 31-35), respectively. In all, 51% (95% CI, 48-54) received stress testing (52% nuclear stress, 39% stress echocardiogram, 5% exercise, 4% other). In all, 0.9% patients (n = 10, 95% CI, 0.4-1.5) were diagnosed with a non-ST elevation myocardial infarction and 2.2% (n = 23, 95% CI, 1.3-3) with acute coronary syndrome. There was 1 (95% CI, 0%-0.3%) case of a 30-day major adverse cardiovascular events. The 51% stress test utilization rate was less than the range reported in previous CPU studies (P < 0.05). Joint emergency medicine and cardiology management of patients within a CPU protocol is safe, efficacious, and may safely reduce stress testing rates.

  2. A mini slug test method for determination of a local hydraulic conductivity of an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Hinsby, Klaus; Bjerg, Poul Løgstrup; Andersen, Lars J.

    1992-01-01

    distributed measurements of a local hydraulic conductivity at a tracer test site at Vejen, Denmark. The mini slug test results calculated by a modified Dax slug test analysing method, applying the elastic storativity in the Dax equations instead of the specific yield, are in good accordance with the results...

  3. Cardiac stress testing for the diagnosis and management of coronary artery disease: a reference for the primary care physician.

    Science.gov (United States)

    Gajulapalli, Rama Dilip; Aneja, Ashish; Rovner, Aleksandr

    2012-02-01

    Choosing the appropriate stress test is important in the workup of patients with possible myocardial ischemia. This choice often is challenging and sometimes confusing because of the plethora of tests and guidelines available. We present a broad overview of commonly available stress tests and indications to help physicians select the most appropriate stress test for their patients.

  4. Stress-strain relation of bentonite at undrained shear. Laboratory tests to investigate the influence of material composition and test technique

    Energy Technology Data Exchange (ETDEWEB)

    Dueck, Ann; Boergesson, Lennart; Johannesson, Lars-Erik (Clay Technology AB, Lund (Sweden))

    2010-12-15

    This report describes a laboratory study conducted to update the material model of the buffer material used in the analyses of the effect of a rock shear through a deposition hole. The study considers some new conditions and is especially focused on the reference case with MX-80Ca developed for SR-Site (MX-80 ion exchanged to Ca). The material model is based on relations between density, swelling pressure, shear strength and rate of strain. The reference model is described by Boergesson et al. (2010). The laboratory study is focused on undrained stress-strain-strength properties, which have been studied mainly by conducting triaxial tests and unconfined compression tests. The test results are compared to the earlier measurements and models which show that the new results fit very well into the general picture and models. For the new conditions suitable values of constants included in the model are proposed

  5. Stress-strain relation of bentonite at undrained shear. Laboratory tests to investigate the influence of material composition and test technique

    International Nuclear Information System (INIS)

    Dueck, Ann; Boergesson, Lennart; Johannesson, Lars-Erik

    2010-12-01

    This report describes a laboratory study conducted to update the material model of the buffer material used in the analyses of the effect of a rock shear through a deposition hole. The study considers some new conditions and is especially focused on the reference case with MX-80Ca developed for SR-Site (MX-80 ion exchanged to Ca). The material model is based on relations between density, swelling pressure, shear strength and rate of strain. The reference model is described by Boergesson et al. (2010). The laboratory study is focused on undrained stress-strain-strength properties, which have been studied mainly by conducting triaxial tests and unconfined compression tests. The test results are compared to the earlier measurements and models which show that the new results fit very well into the general picture and models. For the new conditions suitable values of constants included in the model are proposed

  6. Testing measurement invariance of the Depression, Anxiety, and Stress Scales (DASS-21) across four countries.

    Science.gov (United States)

    Scholten, Saskia; Velten, Julia; Bieda, Angela; Zhang, Xiao Chi; Margraf, Jürgen

    2017-11-01

    The rising burden of mental and behavioral disorders has become a global challenge (Murray et al., 2012). Measurement invariant clinical instruments are necessary for the assessment of relevant symptoms across countries. The present study tested the measurement invariance of the 21-item version of the Depression, Anxiety, and Stress Scales (DASS; Lovibond & Lovibond, 1995b) in Poland, Russia, the United Kingdom (U.K.), and the United States of America (U.S.). Telephone interviews were conducted with population-based samples (nPL = 1003, nRU = 3020, nU.K. = 1002, nU.S. = 1002). The DASS-21 shows threshold measurement invariance. Comparisons of latent means did not indicate differences between U.K. and U.S. However, Polish and Russian samples reported more depressive symptoms compared with U.K. and U.S. samples; the Russian sample had the highest levels of anxiety symptoms and the Polish sample demonstrated the highest stress levels. The DASS-21 can be recommended to meaningfully compare the relationships between variables across groups and to compare latent means in Polish-, Russian-, and English-speaking populations. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Development of in-situ rock shear test under low compressive to tensile normal stress

    International Nuclear Information System (INIS)

    Nozaki, Takashi; Shin, Koichi

    2003-01-01

    The purpose of this study is to develop an in-situ rock shear testing method to evaluate the shear strength under low normal stress condition including tensile stress, which is usually ignored in the assessment of safety factor of the foundations for nuclear power plants against sliding. The results are as follows. (1) A new in-situ rock shear testing method is devised, in which tensile normal stress can be applied on the shear plane of a specimen by directly pulling up a steel box bonded to the specimen. By applying the counter shear load to cancel the moment induced by the main shear load, it can obtain shear strength under low normal stress. (2) Some model tests on Oya tuff and diatomaceous mudstone have been performed using the developed test method. The shear strength changed smoothly from low values at tensile normal stresses to higher values at compressive normal stresses. The failure criterion has been found to be bi-linear on the shear stress vs normal stress plane. (author)

  8. [Stress-ECG is adequate to detect myocardial ischemia: when are additional diagnostic tests needed?].

    Science.gov (United States)

    Baer, F M

    2007-09-01

    The stress-ECG is the most often adopted and most cost effective initial diagnostic test for the assessment of myocardial ischemia in patients with suspected coronary artery disease (CAD). Prerequisites for the diagnostic usefullness of stress-ECG are a clearly interpretable ST-segment, ability to reach the predicted work load, an intermediate pretest probability for CAD ranging between 10% and 90% and the absence of any contraindications for dynamic exercise. Because of the limited diagnostic sensitivity of about 70%, and a high percentage of patients, who are unable to exercise, a negative stress ECG can definitely not exclude hemodynamically significant CAD. Therefore, stress imaging techniques like myocardial scintigraphy, stress-echocardiography and stress magnetic resonance imaging play a major role in the stepwise diagnostic work-up of patients with suspected CAD. These stress imaging techniques are basically interchangeable since no method is definitely superior to one of the others. However, each method has its specific pros and cons and inherent contraindications. Therefore the choice of the stress imaging method and the form of stress applied should be based on the individual patients characteristics to gain optimal image quality and diagnostic accuracy. Moreover, the decision for one method should take the local availability and institutional expertise of diagnostic centers into account. Although partly substituted by stress imaging techniques the stress-ECG still remains the workhorse for a stepwise diagnostic work-up of patients with suspected CAD.

  9. FlowPing - The New Tool for Throughput and Stress Testing

    Directory of Open Access Journals (Sweden)

    Ondrej Vondrous

    2015-01-01

    Full Text Available This article presents a new tool for network throughput and stress testing. The FlowPing tool is easy to use, and its basic output is very similar to standard Linux ping application. The FlowPing tool is not limited to reach-ability or round trip time testing but is capable of complex UDP based throughput stress testing with rich reporting capabilities on client and server sides. Our new tool implements features, which allow the user to perform tests with variable packet size and traffic rate. All these features can be used in one single test run. This allows the user to use and develop new methodologies for network throughput and stress testing. With the FlowPing tool, it is easy to perform the test with the slowly increasing the amount of network traffic and monitor the behavior of network when the congestion occurs.

  10. Testing the responses of four wheat crop models to heat stress at anthesis and grain filling.

    Science.gov (United States)

    Liu, Bing; Asseng, Senthold; Liu, Leilei; Tang, Liang; Cao, Weixing; Zhu, Yan

    2016-05-01

    Higher temperatures caused by future climate change will bring more frequent heat stress events and pose an increasing risk to global wheat production. Crop models have been widely used to simulate future crop productivity but are rarely tested with observed heat stress experimental datasets. Four wheat models (DSSAT-CERES-Wheat, DSSAT-Nwheat, APSIM-Wheat, and WheatGrow) were evaluated with 4 years of environment-controlled phytotron experimental datasets with two wheat cultivars under heat stress at anthesis and grain filling stages. Heat stress at anthesis reduced observed grain numbers per unit area and individual grain size, while heat stress during grain filling mainly decreased the size of the individual grains. The observed impact of heat stress on grain filling duration, total aboveground biomass, grain yield, and grain protein concentration (GPC) varied depending on cultivar and accumulated heat stress. For every unit increase of heat degree days (HDD, degree days over 30 °C), grain filling duration was reduced by 0.30-0.60%, total aboveground biomass was reduced by 0.37-0.43%, and grain yield was reduced by 1.0-1.6%, but GPC was increased by 0.50% for cv Yangmai16 and 0.80% for cv Xumai30. The tested crop simulation models could reproduce some of the observed reductions in grain filling duration, final total aboveground biomass, and grain yield, as well as the observed increase in GPC due to heat stress. Most of the crop models tended to reproduce heat stress impacts better during grain filling than at anthesis. Some of the tested models require improvements in the response to heat stress during grain filling, but all models need improvements in simulating heat stress effects on grain set during anthesis. The observed significant genetic variability in the response of wheat to heat stress needs to be considered through cultivar parameters in future simulation studies. © 2016 John Wiley & Sons Ltd.

  11. Present-day stress magnitude at depth from leak-off tests in Italy

    Science.gov (United States)

    Mariucci, M. T.; Montone, P.; Pierdominici, S.

    2012-04-01

    We present new results from the analysis of leak-off tests, performed in deep oil wells in Italy, to characterize the present-day stress magnitude and regime in the crust. In the last years we have collected a large number of data (more than 500) from different stress indicators, mainly borehole breakouts, earthquake focal mechanisms and fault data, which provided information on the present-day stress orientations. In some areas the tectonic regime has been inferred either from fault plane solutions of M≥4 earthquakes or from stress inversions of smaller earthquakes. Where seismicity lacks, the regime is not well constrained and little or no information on the magnitude of the crustal stresses is available. In order to improve our knowledge in stress regime and its magnitude in Italy, in this work we use the leak-off test technique. Each test is performed at the bottom of an open hole by sealing off a section and then slowly pressurizing with a fluid until hydraulic tensile fractures develop. The minimum horizontal stress is inferred by leak-off pressure record, the vertical stress is computed by rock density data and the maximum horizontal stress is estimated applying a specific formula from the literature. Thanks to ENI S.p.A. (Italian oil company), that kindly provided new well data, we have been able to perform a critical review of our preliminary calculations and to enhance our previous results concerning stress magnitudes. Totally, we have analyzed 192 leak-off tests at depth between 200 and 5400m (average 1800m). In particular, wells are located along the Italian peninsula and in Sicily: most of them are in the Po Plain and along the Apenninic foredeep; few are in southern Apenninic belt and a few tens are in Sicily. After an accurate selection of the most robust results, we better characterize the Italian stress regime at depth.

  12. Modeling daily gas exchange of a Douglas-fir forest : comparison of three stomatal conductance models with and without a soil water stress function

    NARCIS (Netherlands)

    Wijk, van M.T.; Dekker, S.C.; Bouten, W.; Bosveld, F.C.; Kohsiek, W.; Kramer, K.; Mohren, G.M.J.

    2000-01-01

    Modeling stomatal conductance is a key element in predicting tree growth and water use at the stand scale. We compared three commonly used models of stomatal conductance, the Jarvis-Loustau, Ball-Berry and Leuning models, for their suitability for incorporating soil water stress into their

  13. Amplification of transcutaneous and percutaneous bone-conduction devices with a test-band in an induced model of conductive hearing loss.

    Science.gov (United States)

    Park, Marn Joon; Lee, Jae Ryung; Yang, Chan Joo; Yoo, Myung Hoon; Jin, In Suk; Choi, Chi Ho; Park, Hong Ju

    2016-11-01

    Transcutaneous devices have a disadvantage, the dampening effect by soft tissue between the bone and devices. We investigated hearing outcomes with percutaneous and transcutaneous devices using test-bands in an induced unilateral conductive hearing loss. Comparison of hearing outcomes of two devices in the same individuals. The right ear was plugged in 30 subjects and a test-band with devices (Cochlear™ Baha® BP110 Power and Sophono® Alpha-2 MPO™) was applied on the right mastoid tip with the left ear masked. Sound-field thresholds, speech recognition thresholds (SRTs), and word recognition scores (WRSs) were compared. Aided thresholds of Sophono were significantly better than those of Baha at most frequencies. Sophono WRSs (86 ± 12%) at 40 dB SPL and SRTs (14 ± 5 dB HL) were significantly better than those (73 ± 24% and 23 ± 8 dB HL) of Baha. However, Sophono WRSs (98 ± 3%) at 60 dB SPL did not differ from Baha WRSs (95 ± 12%). Amplifications of the current transcutaneous device were not inferior to those of percutaneous devices with a test-band in subjects with normal bone-conduction thresholds. Since the percutaneous devices can increase the gain when fixed to the skull by eliminating the dampening effect, both devices are expected to provide sufficient hearing amplification.

  14. Bayesian Approach for Constant-Stress Accelerated Life Testing for Kumaraswamy Weibull Distribution with Censoring

    Directory of Open Access Journals (Sweden)

    Abeer Abd-Alla EL-Helbawy

    2016-09-01

    Full Text Available The accelerated life tests provide quick information on the life time distributions by testing materials or products at higher than basic conditional levels of stress such as pressure, high temperature, vibration, voltage or load to induce failures. In this paper, the acceleration model assumed is log linear model. Constant stress tests are discussed based on Type I and Type II censoring. The Kumaraswmay Weibull distribution is used. The estimators of the parameters, reliability, hazard rate functions and p-th percentile at normal condition, low stress, and high stress are obtained. In addition, credible intervals for parameters of the models are constructed. Optimum test plan are designed. Some numerical studies are used to solve the complicated integrals such as Laplace and Markov Chain Monte Carlo methods.

  15. Bayesian Approach for Constant-Stress Accelerated Life Testing for Kumaraswamy Weibull Distribution with Censoring

    Directory of Open Access Journals (Sweden)

    Abeer Abd-Alla EL-Helbawy

    2016-12-01

    Full Text Available The accelerated life tests provide quick information on the life time distributions by testing materials or products at higher than basic conditional levels of stress such as pressure, high temperature, vibration, voltage or load to induce failures. In this paper, the acceleration model assumed is log linear model. Constant stress tests are discussed based on Type I and Type II censoring. The Kumaraswmay Weibull distribution is used. The estimators of the parameters, reliability, hazard rate functions and p-th percentile at normal condition, low stress, and high stress are obtained. In addition, credible intervals for parameters of the models are constructed. Optimum test plan are designed. Some numerical studies are used to solve the complicated integrals such as Laplace and Markov Chain Monte Carlo methods.

  16. Validity of multiple stress creep recovery test for LADOTD asphalt binder specification.

    Science.gov (United States)

    2010-09-01

    The objectives of this research are to characterize the elastic response of various binders used by LADOTD to determine the feasibility of the Multiple Stress Creep Recovery (MSCR) test to be included in the LADOTD asphalt binder specification and to...

  17. Psychometric Characteristics of a Measure of Emotional Dispositions Developed to Test a Developmental Propensity Model of Conduct Disorder

    Science.gov (United States)

    Lahey, Benjamin B.; Applegate, Brooks; Chronis, Andrea M.; Jones, Heather A.; Williams, Stephanie Hall; Loney, Jan; Waldman, Irwin D.

    2008-01-01

    Lahey and Waldman proposed a developmental propensity model in which three dimensions of children's emotional dispositions are hypothesized to transact with the environment to influence risk for conduct disorder, heterogeneity in conduct disorder, and comorbidity with other disorders. To prepare for future tests of this model, a new measure of…

  18. Stress

    Science.gov (United States)

    ... can be life-saving. But chronic stress can cause both physical and mental harm. There are at least three different types of stress: Routine stress related to the pressures of work, family, and other daily responsibilities Stress brought about ...

  19. Study on the Correlation between PSR and Korean Stress Test for Continued Operation of Aging NPP

    International Nuclear Information System (INIS)

    Chung, June Ho; Kim, Tae Ryong

    2013-01-01

    Nuclear Safety and Security Commission (NSSC), Korean nuclear regulatory authority established the stress test guideline based on the EU stress test, and KHNP prepared the execution plan in response to the guideline for the CO of Kori Unit 1 and Wolsong Unit 1. PSR is a comprehensive safety review program for long term operation of NPP, which was developed by IAEA. Korea adopted PSR in 1999 as the regulatory requirement for CO of NPP. The IAEA standard guideline for PSR program was updated in 2003. However, the Korean PSR has not been revised yet to apply the new IAEA guidelines. Additionally, national legal systems and guidelines associated with the adoption of stress tests are urgently required as well. These revisions are imperative in order to ensure the reliability of NPPs, and to promote public acceptance and understanding. This study presents the technical basis and proposals for review actions necessary to address the issues and controversies surrounding the continued operation and decommissioning of aging NPPs in Korea. As discussed earlier in characteristics of Korean Stress Test, it is more comprehensive than the EU Stress Test in terms of its multilateral evaluation which includes equipment durability, plant operation, human factors, and safety margins, hence substantially raising the significance and value of the evaluation process. Thus, the addition of Korean Stress Test to the existing Korean Evaluation of CO is expected to greatly increase the quality of safety assessment of aging NPPs in Korea due to its stricter safety policies, hence providing a more meaningful evaluation process. However, a one-time application of the Korean Stress Test to only Kori Unit 1 and Wolsong Unit 1 would be a waste of the great effort that has been done thus far to improve the Korean Evaluation of CO and develop the Korean Stress Test. By extending the Korean Stress Test to all NPPs in Korea would maintain and ensure the reliability of NPPs as well as public

  20. Slug Test Characterization Results for Multi-Test/Depth Intervals Conducted During the Drilling of CERCLA Operable Unit OU ZP-1 Wells 299-W11-43, 299-W15-50, and 299-W18-16

    Energy Technology Data Exchange (ETDEWEB)

    Spane, Frank A.; Newcomer, Darrell R.

    2010-06-21

    The following report presents test descriptions and analysis results for multiple, stress level slug tests that were performed at selected test/depth intervals within three Operable Unit (OU) ZP-1 wells: 299-W11-43 (C4694/Well H), 299-W15-50 (C4302/Well E), and 299-W18-16 (C4303/Well D). These wells are located within south-central region of the Hanford Site 200-West Area (Figure 1.1). The test intervals were characterized as the individual boreholes were advanced to their final drill depths. The primary objective of the hydrologic tests was to provide information pertaining to the areal variability and vertical distribution of hydraulic conductivity with depth at these locations within the OU ZP-1 area. This type of characterization information is important for predicting/simulating contaminant migration (i.e., numerical flow/transport modeling) and designing proper monitor well strategies for OU and Waste Management Area locations.

  1. Slug Test Characterization Results for Multi-Test/Depth Intervals Conducted During the Drilling of CERCLA Operable Unit OU UP-1 Wells 299-W19-48, 699-30-66, and 699-36-70B

    Energy Technology Data Exchange (ETDEWEB)

    Spane, Frank A.; Newcomer, Darrell R.

    2010-06-15

    This report presents test descriptions and analysis results for multiple, stress-level slug tests that were performed at selected test/depth intervals within three Operable Unit (OU) UP-1 wells: 299-W19-48 (C4300/Well K), 699-30-66 (C4298/Well R), and 699-36-70B (C4299/Well P). These wells are located within, adjacent to, and to the southeast of the Hanford Site 200-West Area. The test intervals were characterized as the individual boreholes were advanced to their final drill depths. The primary objective of the hydrologic tests was to provide information pertaining to the areal variability and vertical distribution of hydraulic conductivity with depth at these locations within the OU UP-1 area. This type of characterization information is important for predicting/simulating contaminant migration (i.e., numerical flow/transport modeling) and designing proper monitor well strategies for OU and Waste Management Area locations.

  2. Stress analysis of HLW containers advanced test work Compas project

    International Nuclear Information System (INIS)

    Ove Arup and Partners

    1990-01-01

    The Compas project is concerned with the structural performance of metal overpacks which may be used to encapsulate vitrified high-level waste forms before disposal in deep geological repositories. This document describes the activities performed between June and August 1989 forming the advanced test work phase of this project. This is the culmination of two years' analysis and test work to demonstrate whether the analytical ability exists to model containers subjected to realistic loads. Three mild steel containers were designed and manufactured to be one-third scale models of a realistic HLW container, modified to represent the effect of anisotropic loading and to facilitate testing. The containers were tested under a uniform external pressure and all failed by buckling in the mid-body region. The outer surface of each container was comprehensively strain-gauged to provide strain history data at all positions of interest. In parallel with the test work, Compas project partners, from five different European countries, independently modelled the behaviour of each of the containers using their computer codes to predict the failure pressure and produce strain history data at a number of specified locations. The first axisymmetric container was well modelled but predictions for the remaining two non-axisymmetric containers were much more varied, with differences of up to 50% occurring between failure predictions and test data

  3. GIS surface effects archive of underground nuclear detonations conducted at Yucca Flat and Pahute Mesa, Nevada Test Site, Nevada

    International Nuclear Information System (INIS)

    Grasso, D.N.

    2001-01-01

    This report presents a new comprehensive, digital archive of more than 40 years of geologic surface effects maps produced at individual detonation sites throughout the Yucca Flat and Pahute Mesa nuclear testing areas of the Nevada Test Site, Nye County, Nevada. The Geographic Information System (GIS) surface effects map archive on CD-ROM (this report) comprehensively documents the surface effects of underground nuclear detonations conducted at two of the most extensively used testing areas of the Nevada Test Site. Between 1951 and 1992, numerous investigators of the U.S. Geological Survey, the Los Alamos National Laboratory, the Lawrence Livermore National Laboratory, and the Defense Threat Reduction Agency meticulously mapped the surface effects caused by underground nuclear testing. Their work documented the effects of more than seventy percent of the underground nuclear detonations conducted at Yucca Flat and all of the underground nuclear detonations conducted at Pahute Mesa

  4. Stress transfer of a Kevlar 49 fiber pullout test studied by micro-Raman spectroscopy.

    Science.gov (United States)

    Lei, Zhenkun; Wang, Quan; Qiu, Wei

    2013-06-01

    The interfacial stress transfer behavior of a Kevlar 49 aramid fiber-epoxy matrix was studied with fiber pullout tests, the fibers of which were stretched by a homemade microloading device. Raman spectra on the embedded fiber were recorded by micro-Raman spectroscopy, under different strain levels. Then, the fiber axial stress was obtained by the relationship between the stress and Raman shift of the aramid fiber. Experimental results revealed that the fiber axial stress increased significantly with the load. The shear stress concentration occurred at the fiber entry to the epoxy resin. Thus, interfacial friction stages exist in the debonded fiber segment, and the interfacial friction shear stress is constant within one stage. The experimental results are consistent with the theoretical model predictions.

  5. In situ testing to determination field-saturated hydraulic conductivity of UMTRA Project disposal cell covers, liners, and foundation areas

    International Nuclear Information System (INIS)

    1994-02-01

    This special study was conducted to prepare a guidance document for selecting in situ hydraulic conductivity (K) tests, comparing in situ testing methods, and evaluating the results of such tests. This report may be used as a practical decision-making tool by the Uranium Mill Tailings Remedial Action (UMTRA) Project staff to determine which testing method will most efficiently achieve the field-saturated K results needed for long-term planning. A detailed section on near-surface test methods discusses each method which may be applicable to characterization of UMTRA disposal cell covers, liners and foundation materials. These potentially applicable test methods include the sealed double-ring infiltrometer (SDRI), the air-entry permeameter (AEP), the guelph permeameter, the two-stage borehole technique (TSB), the pressure infiltrometer, and the disk permeameter. Analytical solutions for these methods are provided, and limitations of these solutions are discussed, and a description of testing equipment design and installation are provided

  6. Aquaporin-mediated increase in root hydraulic conductance is involved in silicon-induced improved root water uptake under osmotic stress in Sorghum bicolor L.

    Science.gov (United States)

    Liu, Peng; Yin, Lina; Deng, Xiping; Wang, Shiwen; Tanaka, Kiyoshi; Zhang, Suiqi

    2014-09-01

    The fact that silicon application alleviates water deficit stress has been widely reported, but the underlying mechanism remains unclear. Here the effects of silicon on water uptake and transport of sorghum seedlings (Sorghum bicolor L.) growing under polyethylene glycol-simulated osmotic stress in hydroponic culture and water deficit stress in sand culture were investigated. Osmotic stress dramatically decreased dry weight, photosynthetic rate, transpiration rate, stomatal conductance, and leaf water content, but silicon application reduced these stress-induced decreases. Although silicon application had no effect on stem water transport capacity, whole-plant hydraulic conductance (Kplant) and root hydraulic conductance (Lp) were higher in silicon-treated seedlings than in those without silicon treatment under osmotic stress. Furthermore, the extent of changes in transpiration rate was similar to the changes in Kplant and Lp. The contribution of aquaporin to Lp was characterized using the aquaporin inhibitor mercury. Under osmotic stress, the exogenous application of HgCl2 decreased the transpiration rates of seedlings with and without silicon to the same level; after recovery induced by dithiothreitol (DTT), however, the transpiration rate was higher in silicon-treated seedlings than in untreated seedlings. In addition, transcription levels of several root aquaporin genes were increased by silicon application under osmotic stress. These results indicate that the silicon-induced up-regulation of aquaporin, which was thought to increase Lp, was involved in improving root water uptake under osmotic stress. This study also suggests that silicon plays a modulating role in improving plant resistance to osmotic stress in addition to its role as a mere physical barrier. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  7. An accelerated life test model for harmonic drives under a segmental stress history and its parameter optimization

    Directory of Open Access Journals (Sweden)

    Zhang Chao

    2015-12-01

    Full Text Available Harmonic drives have various distinctive advantages and are widely used in space drive mechanisms. Accelerated life test (ALT is commonly conducted to shorten test time and reduce associated costs. An appropriate ALT model is needed to predict the lifetime of harmonic drives with ALT data. However, harmonic drives which are used in space usually work under a segmental stress history, and traditional ALT models can hardly be used in this situation. This paper proposes a dedicated ALT model for harmonic drives applied in space systems. A comprehensive ALT model is established and genetic algorithm (GA is adopted to obtain optimal parameters in the model using the Manson fatigue damage rule to describe the fatigue failure process and a cumulative damage method to calculate and accumulate the damage caused by each segment in the stress history. An ALT of harmonic drives was carried out and experimental results show that this model is acceptable and effective.

  8. Endogenous salivary α-amylase does not interact with skin conductance response during fear extinction in posttraumatic stress disorder.

    Science.gov (United States)

    Zuj, Daniel V; Palmer, Matthew A; Malhi, Gin S; Bryant, Richard A; Felmingham, Kim L

    2018-04-01

    Posttraumatic Stress Disorder (PTSD) is associated with elevated noradrenergic signaling, which has an impact on emotional learning and memory. Fear extinction is thought to underlie the processes of exposure therapy, however the relationship between noradrenaline and extinction in PTSD is unclear. Participants with PTSD (n = 21), trauma-exposure without PTSD (TC; n = 36), and non-trauma-exposed controls (NTC; n = 27) completed a fear conditioning and extinction paradigm, and conditioned fear was indexed by skin conductance response (SCR). Salivary α-amylase (sAA) collected at baseline and immediately post-fear acquisition was used as an index of noradrenaline, and we examined whether sAA in response to fear acquisition was a moderator between fear extinction and PTSD symptoms. While there was a significant increase in sAA from baseline to post-fear acquisition, this was not modulated by group. Compared to TC and NTC, the PTSD group displayed a slower decline in SCRs during early extinction, which generalized across stimulus type, and was not moderated by sAA. These findings suggest that the relationship between fear extinction and PTSD symptoms does not change as a function of sAA levels; however previous research suggests other processes of fear learning may be associated with noradrenergic activity in PTSD. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  9. Fracture hydraulic conductivity in the Mexico City clayey aquitard: Field piezometer rising-head tests

    Science.gov (United States)

    Vargas, Carlos; Ortega-Guerrero, Adrián

    A regional lacustrine aquitard covers the main aquifer of the metropolitan area of Mexico City. The aquitard's hydraulic conductivity (K') is fundamental for evaluating the natural protection of the aquifer against a variety of contaminants present on the surface and its hydraulic response. This study analyzes the distribution and variation of K' in the plains of Chalco, Texcoco and Mexico City (three of the six former lakes that existed in the Basin of Mexico), on the basis of 225 field-permeability tests, in nests of existing piezometers located at depths of 2-85 m. Tests were interpreted using the Hvorslev method and some by the Bouwer-Rice method. Results indicate that the distribution of K' fits log-Gaussian regression models. Dominant frequencies for K' in the Chalco and Texcoco plains range between 1E-09 and 1E-08 m/s, with similar population means of 1.19E-09 and 1.7E-09 m/s, respectively, which are one to two orders of magnitude higher than the matrix conductivity. In the Mexico City Plain the population mean is near by one order of magnitude lower; K'=2.6E-10 m/s. The contrast between the measured K' and that of the matrix is attributed to the presence of fractures in the upper 25-40 m, which is consistent with the findings of previous studies on solute migration in the aquitard. Un imperméable régional d'origine lacustre recouvre le principal aquifère de la zone urbaine de la ville de Mexico. La conductivité hydraulique K' de cet imperméable est fondamentale pour évaluer la protection naturelle de l'aquifère, contre les différents contaminants présents en surface, et sa réponse hydraulique. Cette étude analyse et les variations de K' dans les plaines de Chalco, Texcoco et Mexico (trois des six anciens lacs qui existaient dans le Bassin de Mexico), sur la base de 225 essais de perméabilité sur le terrain, réalisés en grappes dans des piézomètres existants entre 2 et 85 m de profondeur. Les essais ont été interprétés avec la m

  10. CONDUCTING AND ANALYZING THE RESULTS OF THE EXPERIMENTAL BOX TEST OF RETAINING WALL MODELS WITHOUT PILES AND ON THE PILE FOUNDATION

    Directory of Open Access Journals (Sweden)

    M. A. Lisnevskyi

    2015-08-01

    Full Text Available Purpose. Taking into consideration that the bearing capacity of the foundation may be insufficient, in the study it is assumed that pile foundation can be used to reduce the impact of the construction of new retaining structures on roads and railways near the existing buildings or in areas of dense urban development and ensure the stability of the foundation. To reduce the volume of excavation it is necessary to choose the economic structure of the retaining wall. To do this, one should explore stress-strain state (SSS of the retaining walls, to develop methods to improve their strength and stability, as well as to choose the most appropriate method of their analysis. Methodology. In the design of retaining walls foundation mat and piles are considered as independent elements. Since the combined effect of the retaining wall, piles and foundation mat as well as the effect of soil or rock foundation on the structure are considered not fully, so there are some limitations in the existing design techniques. To achieve the purpose the box tests of retaining walls models without piles and with piles for studying their interaction with the surrounding soil massif were conducted. Findings. Laboratory simulation of complex systems «surrounding soil – retaining wall – pile» was carried out and on the basis of the box test results were analyzed strains and its main parameters of the stress-strain state. Analysis of the results showed that the structure of a retaining wall with piles is steady and stable. Originality. So far, in Ukraine has not been carried out similar experimental box tests with models of retaining walls in such combinations. In the article has been presented unique photos and test results, as well as their analysis. Practical value. Using the methodology of experimental tests of the retaining wall models with piles and without them gives a wider opportunity to study stress-strain state of such structures.

  11. Hysteresis analysis of graphene transistor under repeated test and gate voltage stress

    International Nuclear Information System (INIS)

    Yang Jie; Jia Kunpeng; Su Yajuan; Zhao Chao; Chen Yang

    2014-01-01

    The current transport characteristic is studied systematically based on a back-gate graphene field effect transistor, under repeated test and gate voltage stress. The interface trapped charges caused by the gate voltage sweep process screens the gate electric field, and results in the neutral point voltage shift between the forth and back sweep direction. In the repeated test process, the neutral point voltage keeps increasing with test times in both forth and back sweeps, which indicates the existence of interface trapped electrons residual and accumulation. In gate voltage stress experiment, the relative neutral point voltage significantly decreases with the reducing of stress voltage, especially in −40 V, which illustrates the driven-out phenomenon of trapped electrons under negative voltage stress. (semiconductor devices)

  12. Effects of electric field and Coriolis force on electrohydrodynamic stability of poorly conducting couple stress parallel fluid flow in a channel

    International Nuclear Information System (INIS)

    Shankar, B.M.; Rudraiah, N.

    2013-01-01

    The linear stability of electrohydrodynamic poorly conducting couple stress viscous parallel fluid flow in a channel is studied in the presence of a non-uniform transverse electric field and Coriolis force using energy method and supplemented with Galerkin Technique. The sufficient condition for stability is obtained for sufficiently small values of the Reynolds number, R e . From this condition we show that strengthening or weakening of the stability criterion is dictated by the values of the strength of electric field, the coefficient of couple stress fluid and independent of Taylor number. In particular, it is shown that the interaction of electric field with couple stress is more effective in stabilizing the poorly conducting couple stress fluid compared to that in an ordinary Newtonian viscous fluid. (author)

  13. The "moving valgus stress test" for medial collateral ligament tears of the elbow.

    Science.gov (United States)

    O'Driscoll, Shawn W M; Lawton, Richard L; Smith, Adam M

    2005-02-01

    The diagnosis of a painful partial tear of the medial collateral ligament in overhead-throwing athletes is challenging, even for experienced elbow surgeons and despite the use of sophisticated imaging techniques. The "moving valgus stress test" is an accurate physical examination technique for diagnosis of medial collateral ligament attenuation in the elbow. Cohort study (diagnosis); Level of evidence, 2. Twenty-one patients underwent surgical intervention for medial elbow pain due to medial collateral ligament insufficiency or other abnormality of chronic valgus overload, and they were assessed preoperatively with an examination called the moving valgus stress test. To perform the moving valgus stress test, the examiner applies and maintains a constant moderate valgus torque to the fully flexed elbow and then quickly extends the elbow. The test is positive if the medial elbow pain is reproduced at the medial collateral ligament and is at maximum between 120 degrees and 70 degrees. The moving valgus stress test was highly sensitive (100%, 17 of 17 patients) and specific (75%, 3 of 4 patients) when compared to assessment of the medial collateral ligament by surgical exploration or arthroscopic valgus stress testing. The mean shear range (ie, the arc within which pain was produced with the moving valgus stress test) was 120 degrees to 70 degrees. The mean angle at which pain was at a maximum was 90 degrees of elbow flexion. The moving valgus stress test is an accurate physical examination technique that, when performed and interpreted correctly, is highly sensitive for medial elbow pain arising from the medial collateral ligament.

  14. Stress-Dilatancy of Cambria Sand for Triaxial Tests at High Pressures

    Science.gov (United States)

    Szypcio, Zenon

    2017-12-01

    In this paper, the stress-dilatancy relationship of Cambria sand for drained triaxial compression and extension tests at high stress level is investigated. The stress dilatancy relationship is obtained by use of frictional state theory and experimental tests data published in literature. It is shown that stress-dilatancy relationship is bilinear, described by three parameters of frictional state theory: critical frictional angle and two other parameters. It is accepted that critical friction angle is independent of confining pressure. The two additional parameters are strongly dependent on confining pressure and different for initial and advanced stages. The point at which the values of these parameters change is termed as Transformation Shear Point. This point is not simply visible either in stress ratio-strain or the volume strain-shear strain relationship which are traditionally shown in soil mechanics papers. Transformation Shear Point is very characteristic in stress ratio-plastic dilatancy plane. Thus, stress ratio- plastic dilatancy is very important for describing stress-strain behaviour of soils. The relationship shown in the paper can be used in soil modelling in the future.

  15. Unconscious fearful priming followed by a psychosocial stress test results in higher cortisol levels.

    Science.gov (United States)

    Hänsel, Alexander; von Känel, Roland

    2013-10-01

    Human perception of stress includes an automatic pathway that processes subliminal presented stimuli below the threshold of conscious awareness. Subliminal stimuli can therefore activate the physiologic stress system. Unconscious emotional signals were shown to significantly moderate reactions and responses to subsequent stimuli, an effect called 'priming'. We hypothesized that subliminal presentation of a fearful signal during the Stroop task compared with an emotionally neutral one will prime stress reactivity in a subsequently applied psychosocial stress task, thereby yielding a significant increase in salivary cortisol. Half of 36 participants were repeatedly presented either a fearful face or a neutral one. After this, all underwent a psychosocial stress task. The fearful group showed a significant increase in cortisol levels (p = 0.022). This change was not affected by sex, age and body mass index, and it also did not change when taking resting cortisol levels into account. Post-hoc analyses showed that the increase in cortisol in the fearful group started immediately after the psychosocial stress test. Hence, subliminal exposure to a fearful signal in combination with the Stroop and followed by a psychosocial stress test leads to an increase in stress reactivity. Copyright © 2012 John Wiley & Sons, Ltd.

  16. Preliminary Development of Conductivity based Test Method for Industrial Radiography Film Developer Solution

    International Nuclear Information System (INIS)

    Zainuddin, N.S.; Manah, N.S.A.; Khairul Anuar Mohd Salleh; Noorhazleena Azaman

    2015-01-01

    The strength of industrial radiography film developer solution is one of the most important aspects in radiography film processing. The developer solution reacts with the exposed film to visualize the latent image through chemical-film reaction. As the developer is repeatedly used, the strength decreases until a point where it cannot yield the required film optical density value. This work attempts to investigate the developer solution strength through its conductivity. Obtained data are cross correlated to the required industrial radiography optical density range. Through the experiment, the conductivity of the developer solution decreased as the number of the film processed increase. Thus, the desired optical density of the film cannot be achieved. The conductivity of developer is measured and recorded at interval of six films developed. The optical density of every film is recorded to analyze the change in optical density as the conductivity decreases. Through the procedure, it is suggested that as the conductivity decreases, the optical density of film decreased. Ultimately, the strength level of the developer solution can be determined. (author)

  17. MDMA does not alter responses to the Trier Social Stress Test in humans.

    Science.gov (United States)

    Bershad, Anya K; Miller, Melissa A; de Wit, Harriet

    2017-07-01

    ±3,4-Methylenedioxymethamphetamine (MDMA, "ecstasy") is a stimulant-psychedelic drug with unique social effects. It may dampen reactivity to negative social stimuli such as social threat and rejection. Perhaps because of these effects, MDMA has shown promise as a treatment for post-traumatic stress disorder (PTSD). However, the effect of single doses of MDMA on responses to an acute psychosocial stressor has not been tested. In this study, we sought to test the effects of MDMA on responses to stress in healthy adults using a public speaking task. We hypothesized that the drug would reduce responses to the stressful task. Volunteers (N = 39) were randomly assigned to receive placebo (N = 13), 0.5 mg/kg MDMA (N = 13), or 1.0 mg/kg MDMA (N = 13) during a stress and a no-stress session. Dependent measures included subjective reports of drug effects and emotional responses to the task, as well as salivary cortisol, heart rate, and blood pressure. The stress task produced its expected increase in physiological responses (cortisol, heart rate) and subjective ratings of stress in all three groups, and MDMA produced its expected subjective and physiological effects. MDMA alone increased ratings of subjective stress, heart rate, and saliva cortisol concentrations, but contrary to our hypothesis, it did not moderate responses to the Trier Social Stress Test. Despite its efficacy in PTSD and anxiety, MDMA did not reduce either the subjective or objective responses to stress in this controlled study. The conditions under which MDMA relieves responses to negative events or memories remain to be determined.

  18. Work related stress and its anticipated solutions among post-graduate medical resident doctors: a cross-sectional survey conducted at a tertiary municipal hospital in Mumbai, India.

    Science.gov (United States)

    Rajan, Pavithra; Bellare, Bharati

    2011-03-01

    It is now known that resident doctors registered for postgraduate studies are prone to work related stress and eventual burnout. Though stress can happen in any profession, reduced performance of resident doctors due to vocational stress could cause an increase in medical errors and thus affect the quality of life of the patients. Resident doctors at a Municipal hospital in India form a unique population as number of stresses they undergo are many and varied. To study the prevalence of work-related stress and its anticipated solutions among the resident doctors registered for postgraduate studies in clinical subjects at a tertiary Municipal hospital. A stratified sampling cross-sectional survey was conducted at the Inpatient, Outpatient, and Intensive Care Units at a tertiary Municipal hospital in Mumbai, India. Data collection was done using a validated 20-point questionnaire to assess the factors causing stress and their anticipated solutions. Simple percentage analysis of stress questionnaire. 71 resident doctors completed the survey. The major stressors in this cohort were inadequate hostel/quarter facilities (92.1%), and the need to perform extra duties (80.0%). Also, non-conducive environment for clinical training and studies (81.7%), inadequate study (78.9%) and break (81.2%), threat from deadly infections (74.6%), and overburdening with work (69.0%) were the other major stress causing factors. The perceived stress busters were good music (40.8%) and family and friends (40.8%). Eighty-seven percent of the respondents perceived regular physical exercise to be an effective mode of stress management and 83.8% expressed their need to have a simple therapeutic gymnasium established within the campus with a qualified trainer. There is a high level of work related stress among the resident doctors registered for postgraduate clinical studies at a tertiary Municipal hospital in Mumbai. One of the perceived stress busters is regular physical exercise that is

  19. [Effects of psychological stress on performances in open-field test of rats and tyrosine's modulation].

    Science.gov (United States)

    Chen, Wei-Qiang; Cheng, Yi-Yong; Li, Shu-Tian; Hong, Yan; Wang, Dong-Lan; Hou, Yue

    2009-02-01

    To explore the effects of different doses of tyrosine modulation on behavioral performances in open field test of psychological stress rats. The animal model of psychological stress was developed by restraint stress for 21 days. Wistar rats were randomly assigned to five groups (n = 10) as follows: control group (CT), stress control group (SCT), low, medium and high-doses of tyrosine modulation stress groups (SLT, SMT and SIT). The changes of behavioral performances were examined by open-field test. Serum levels of cortisol, norepinephrine and dopamine were also detected. The levels of serum cortisol were all increased obviously in the four stress groups, and their bodyweight gainings were diminished. The behavioral performances of SCT rats in open-field test were changed significantly in contrast to that of CT rats. However, The behavioral performances of SMT and SHT rats were not different from that of CT rats. In addition, the serum levels of norepinephrine and dopamine were downregulated obviously in SCT and SLT groups, and no differences were observed in other groups. Psychological stress can impair body behavioral performances, and moderate tyrosine modulation may improve these abnormal changes. The related mechanisms may be involved with the changes of norepinephrine and dopamine.

  20. Stress transmission through Ti-Ni alloy, titanium and stainless steel in impact compression test.

    Science.gov (United States)

    Yoneyama, T; Doi, H; Kobayashi, E; Hamanaka, H; Tanabe, Y; Bonfield, W

    2000-06-01

    Impact stress transmission of Ti-Ni alloy was evaluated for biomedical stress shielding. Transformation temperatures of the alloy were investigated by means of DSC. An impact compression test was carried out with use of split-Hopkinson pressure-bar technique with cylindrical specimens of Ti-Ni alloy, titanium and stainless steel. As a result, the transmitted pulse through Ti-Ni alloy was considerably depressed as compared with those through titanium and stainless steel. The initial stress reduction was large through Ti-Ni alloy and titanium, but the stress reduction through Ti-Ni alloy was more continuous than titanium. The maximum value in the stress difference between incident and transmitted pulses through Ti-Ni alloy or titanium was higher than that through stainless steel, while the stress reduction in the maximum stress through Ti-Ni alloy was statistically larger than that through titanium or stainless steel. Ti-Ni alloy transmitted less impact stress than titanium or stainless steel, which suggested that the loading stress to adjacent tissues could be decreased with use of Ti-Ni alloy as a component material in an implant system. Copyright 2000 Kluwer Academic Publishers

  1. Results of fatigue tests and prediction of fatigue life under superposed stress wave and combined superposed stress wave

    International Nuclear Information System (INIS)

    Takasugi, Shunji; Horikawa, Takeshi; Tsunenari, Toshiyasu; Nakamura, Hiroshi

    1983-01-01

    In order to examine fatigue life prediction methods at high temperatures where creep damage need not be taken into account, fatigue tests were carried out on plane bending specimens of alloy steels (SCM 435, 2 1/4Cr-1Mo) under superposed and combined superposed stress waves at room temperature and 500 0 C. The experimental data were compared with the fatigue lives predicted by using the cycle counting methods (range pair, range pair mean and zero-cross range pair mean methods), the modified Goodman's equation and the modified Miner's rule. The main results were as follows. (1) The fatigue life prediction method which is being used for the data at room temperature is also applicable to predict the life at high temperatures. The range pair mean method is especially better than other cycle counting methods. The zero-cross range pair mean method gives the estimated lives on the safe side of the experimental lives. (2) The scatter bands of N-bar/N-barsub(es) (experimental life/estimated life) becomes narrower when the following equation is used instead of the modified Goodman's equation for predicting the effect of mean stress on fatigue life. σ sub(t) = σ sub(a) / (1 - Sigma-s sub(m) / kσ sub(B)) σ sub(t); stress amplitude at zero mean stress (kg/mm 2 ) σ sub(B); tensile strength (kg/mm 2 ) σ sub(m); mean stress (kg/mm 2 ) σ sub(a); stress amplitude (kg/mm 2 ) k; modified coefficient of σ sub(B) (author)

  2. Critical Review of EU Nuclear Stress Tests in Bulgaria, Hungary, Romania and Ukraine

    International Nuclear Information System (INIS)

    Becker, O.; Lorenz, P.; Wallner, A.

    2012-01-01

    In March 2011, the core melt accidents at the Fukushima Daiichi 1 nuclear power plant (NPP) showed the world that the nuclear industry cannot prevent severe accidents from happening. The accidents in Japan proved that highly unlikely accidents cannot be excluded. The Fukushima accident confirmed the mistrust towards nuclear power among the Japanese but also European citizens. In reaction to the devastating nuclear disaster in Japan the European Council concluded in March 2011, that the safety of all EU nuclear plants should be reviewed on the basis of a comprehensive and transparent risk and safety assessment ('stress tests'). The EU Nuclear Safety Regulators Group – ENSREG took over the task to provide a “targeted reassessment of the safety margins of nuclear power plants”, thus examining whether the safety margins which were used in the licensing of NPPs are sufficient to cover unexpected events. It is important to understand that the stress tests could not take into account all key safety issues such as the capability to prevent accidents - the scope of the stress tests defined by ENSREG didn´t promise to deliver a comprehensive risk and safety assessment. According to some observers the stress tests were mainly set up to improve the confidence in the safety of European NPPs. Nevertheless, the stress tests provided some interesting findings concerning safety: This study assesses the safety of the nuclear power plants in Bulgaria, Hungary, Romania and the Ukraine. The introduction contains an overview of the content and procedure of the stress tests. This “Critical Review of the Stress Tests” is based on the national stress tests reports written by the national nuclear safety authorities and on the Peer review country reports attached to the Peer review report - Stress tests performed on European nuclear power plants written by the Peer review Teams, the Peer Review Board respectively, and endorsed by ENSREG [ENSREG 2012a, ENSREG 2012c]. It

  3. Critical Review of EU Nuclear Stress Tests in Bulgaria, Hungary, Romania and Ukraine

    Energy Technology Data Exchange (ETDEWEB)

    Becker, O.; Lorenz, P.; Wallner, A.

    2012-07-01

    In March 2011, the core melt accidents at the Fukushima Daiichi 1 nuclear power plant (NPP) showed the world that the nuclear industry cannot prevent severe accidents from happening. The accidents in Japan proved that highly unlikely accidents cannot be excluded. The Fukushima accident confirmed the mistrust towards nuclear power among the Japanese but also European citizens. In reaction to the devastating nuclear disaster in Japan the European Council concluded in March 2011, that the safety of all EU nuclear plants should be reviewed on the basis of a comprehensive and transparent risk and safety assessment ('stress tests'). The EU Nuclear Safety Regulators Group – ENSREG took over the task to provide a “targeted reassessment of the safety margins of nuclear power plants”, thus examining whether the safety margins which were used in the licensing of NPPs are sufficient to cover unexpected events. It is important to understand that the stress tests could not take into account all key safety issues such as the capability to prevent accidents - the scope of the stress tests defined by ENSREG didn´t promise to deliver a comprehensive risk and safety assessment. According to some observers the stress tests were mainly set up to improve the confidence in the safety of European NPPs. Nevertheless, the stress tests provided some interesting findings concerning safety: This study assesses the safety of the nuclear power plants in Bulgaria, Hungary, Romania and the Ukraine. The introduction contains an overview of the content and procedure of the stress tests. This “Critical Review of the Stress Tests” is based on the national stress tests reports written by the national nuclear safety authorities and on the Peer review country reports attached to the Peer review report - Stress tests performed on European nuclear power plants written by the Peer review Teams, the Peer Review Board respectively, and endorsed by ENSREG [ENSREG 2012a, ENSREG 2012c]. It continues

  4. 40 CFR 63.3360 - What performance tests must I conduct?

    Science.gov (United States)

    2010-07-01

    ... gaseous non-methane organic matter concentration. Use the same test method for both the inlet and outlet... exchange occurs. (B) Use the data collected during the performance test to calculate and record the average..., the outlet of the last control device in the series, and all intermediate streams (e.g., gaseous...

  5. Laser-accelerated particle beams for stress testing of materials.

    Science.gov (United States)

    Barberio, M; Scisciò, M; Vallières, S; Cardelli, F; Chen, S N; Famulari, G; Gangolf, T; Revet, G; Schiavi, A; Senzacqua, M; Antici, P

    2018-01-25

    Laser-driven particle acceleration, obtained by irradiation of a solid target using an ultra-intense (I > 10 18  W/cm 2 ) short-pulse (duration testing materials and are particularly suited for identifying materials to be used in harsh conditions. We show that these laser-generated protons can produce, in a very short time scale, a strong mechanical and thermal damage, that, given the short irradiation time, does not allow for recovery of the material. We confirm this by analyzing changes in the mechanical, optical, electrical, and morphological properties of five materials of interest to be used in harsh conditions.

  6. Guidelines for conducting impact tests on shipping packages for radioactive material

    International Nuclear Information System (INIS)

    Mok, G.C.; Carlson, R.W.; Lu, S.C.; Fischer, L.E.

    1995-09-01

    Federal regulation (10 CFR Part 71) specifies a number of impact conditions (free-drop, penetration, and puncture), under which a package for the transport of radioactive materials must be tested or evaluated to demonstrate compliance with the regulation. This report is a comprehensive guide to the planning and execution of these impact tests. The report identifies the required considerations for both the design, pre-, and post-test inspections of the test model and the measurement, recording, analysis, and reporting of the test data. The report also presents reasons for the requirements, identifies the major difficulties in meeting these requirements, and suggests possible methods to overcome the difficulties. Discussed in substantial detail is the use of scale models and instrumented measurements

  7. Phreatophytes under stress: transpiration and stomatal conductance of saltcedar (Tamarix spp.) in a high-salinity environment

    Science.gov (United States)

    Glenn, Edward P.; Nagler, Pamela L.; Morino, Kiyomi; Hultine, Kevin

    2013-01-01

    Background and aims: We sought to understand the environmental constraints on an arid-zone riparian phreatophtye, saltcedar (Tamarix ramosissima and related species and hybrids), growing over a brackish aquifer along the Colorado River in the western U.S. Depth to groundwater, meteorological factors, salinity and soil hydraulic properties were compared at stress and non-stressed sites that differed in salinity of the aquifer, soil properties and water use characteristics, to identify the factors depressing water use at the stress site.

  8. Voltage stress effects on microcircuit accelerated life test failure rates

    Science.gov (United States)

    Johnson, G. M.

    1976-01-01

    The applicability of Arrhenius and Eyring reaction rate models for describing microcircuit aging characteristics as a function of junction temperature and applied voltage was evaluated. The results of a matrix of accelerated life tests with a single metal oxide semiconductor microcircuit operated at six different combinations of temperature and voltage were used to evaluate the models. A total of 450 devices from two different lots were tested at ambient temperatures between 200 C and 250 C and applied voltages between 5 Vdc and 15 Vdc. A statistical analysis of the surface related failure data resulted in bimodal failure distributions comprising two lognormal distributions; a 'freak' distribution observed early in time, and a 'main' distribution observed later in time. The Arrhenius model was shown to provide a good description of device aging as a function of temperature at a fixed voltage. The Eyring model also appeared to provide a reasonable description of main distribution device aging as a function of temperature and voltage. Circuit diagrams are shown.

  9. Standard test method for conducting drop-weight test to determine nil-ductility transition temperature of ferritic steels

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This test method covers the determination of the nil-ductility transition (NDT) temperature of ferritic steels, 5/8 in. (15.9 mm) and thicker. 1.2 This test method may be used whenever the inquiry, contract, order, or specification states that the steels are subject to fracture toughness requirements as determined by the drop-weight test. 1.3 The values stated in inch-pound units are to be regarded as the standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  10. Test of Alternative Hypotheses Explaining the Comorbidity between Attention-Deficit/Hyperactivity Disorder and Conduct Disorder

    Science.gov (United States)

    Rhee, Soo Hyun; Willcutt, Erik G.; Hartman, Christie A.; Pennington, Bruce F.; DeFries, John C.

    2008-01-01

    There is significant comorbidity between attention-deficit/hyperactivity disorder (ADHD) and conduct disorder (CD). The conclusions of studies that examined the causes of comorbidity between ADHD and CD conflict, with some researchers finding support for the three independent disorders model and others finding support for the correlated risk…

  11. Effect of Mindfulness Meditation on Perceived Stress Scores and Autonomic Function Tests of Pregnant Indian Women.

    Science.gov (United States)

    Muthukrishnan, Shobitha; Jain, Reena; Kohli, Sangeeta; Batra, Swaraj

    2016-04-01

    Various pregnancy complications like hypertension, preeclampsia have been strongly correlated with maternal stress. One of the connecting links between pregnancy complications and maternal stress is mind-body intervention which can be part of Complementary and Alternative Medicine (CAM). Biologic measures of stress during pregnancy may get reduced by such interventions. To evaluate the effect of Mindfulness meditation on perceived stress scores and autonomic function tests of pregnant Indian women. Pregnant Indian women of 12 weeks gestation were randomised to two treatment groups: Test group with Mindfulness meditation and control group with their usual obstetric care. The effect of Mindfulness meditation on perceived stress scores and cardiac sympathetic functions and parasympathetic functions (Heart rate variation with respiration, lying to standing ratio, standing to lying ratio and respiratory rate) were evaluated on pregnant Indian women. There was a significant decrease in perceived stress scores, a significant decrease of blood pressure response to cold pressor test and a significant increase in heart rate variability in the test group (pwomen. The results of this study suggest that mindfulness meditation improves parasympathetic functions in pregnant women and is a powerful modulator of the sympathetic nervous system during pregnancy.

  12. Model test study on propagation law of plane stress wave in jointed rock mass under different in-situ stresses

    Science.gov (United States)

    Dong, Qian

    2017-12-01

    The study of propagation law of plane stress wave in jointed rock mass under in-situ stress has important significance for safety excavation of underground rock mass engineering. A model test of the blasting stress waves propagating in the intact rock and jointed rock mass under different in-situ stresses was carried out, and the influencing factors on the propagation law, such as the scale of static loads and the number of joints were studied respectively. The results show that the transmission coefficient of intact rock is larger than that of jointed rock mass under the same loading condition. With the increase of confining pressure, the transmission coefficients of intact rock and jointed rock mass both show an trend of increasing first and then decreasing, and the variation of transmission coefficients in intact rock is smaller than that of jointed rock mass. Transmission coefficient of jointed rock mass decreases with the increase of the number of joints under the same loading condition, when the confining pressure is relatively small, the reduction of transmission coefficients decreases with the increasing of the number of joints, and the variation law of the reduction of transmission coefficients is contrary when the confining pressure is large.

  13. Short-time, high temperature mechanical testing of electrically conductive materials

    International Nuclear Information System (INIS)

    Marion, R.H.; Karnes, C.H.

    1975-10-01

    Design and performance details are given for a facility which was developed to obtain the mechanical properties of materials under high heating rate or transient temperature conditions and medium strain rates. The system is shown to be applicable to materials possessing electrical resistivities ranging from that of aluminum to that of graphite without taxing the heating capability. Heating rates as high as 2000 0 K/s in graphite are attained under controlled conditions. Methods of measuring temperature and the effects of expected temperature distributions are discussed. A method for measuring strain valid for transient temperature conditions to 3000 0 K is described. Results are presented for the stress-strain behavior of 316 stainless steel and ATJ(S) graphite obtained for heating times of a few seconds. (auth)

  14. Large scale permeability test of the granite in the stipa mine and thermal conductivity test. Technical project report No. 2

    International Nuclear Information System (INIS)

    Lundstroem, L.; Stills, H.

    1978-03-01

    The investigated properties of the granite bedrock at Stripa may be summarized as follows: The permeability is very low, 0.4 x 10 -10 m/s, and independent of the pressure gradient. The permeability is reduced by 50 percent at a temperature increase from +10 0 C to +35 0 C. The thermal conductivity was determined in situ to be about 4 W/m 0 C which largely agrees with laboratory determinations. The effective porosity was determined to be 0.012 percent. 12 figs

  15. A Study on the Storage Reliability of LSINS Based on Step-stress Accelerated Life Test

    Directory of Open Access Journals (Sweden)

    Teng Fei

    2015-01-01

    Full Text Available Based on the step-stress accelerated life test and the laser strap-down inertial navigation system, this paper studies the accelerated life model and the test method, provides the likelihood function, the likelihood equation and the two-order derivative when the stress level is k, evaluates the effectiveness of the method with the simulation test model established by MATLAB, applies the research findings in the storage reliability study of the XX laser strap-down inertial navigation system, and puts forward an effective evaluation method of the storage life of the inertial navigation system.

  16. Standard test method for calibration of surface/stress measuring devices

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1997-01-01

    Return to Contents page 1.1 This test method covers calibration or verification of calibration, or both, of surface-stress measuring devices used to measure stress in annealed and heat-strengthened or tempered glass using polariscopic or refractometry based principles. 1.2 This test method is nondestructive. 1.3 This test method uses transmitted light, and therefore, is applicable to light-transmitting glasses. 1.4 This test method is not applicable to chemically tempered glass. 1.5 Using the procedure described, surface stresses can be measured only on the “tin” side of float glass. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  17. Predischarge stress test after myocardial infarction in the old stage : results and prognostic value

    NARCIS (Netherlands)

    P.M. Fioretti (Paolo); J.W. Deckers (Jaap); R.W. Brower (Ronald); M.L. Simoons (Maarten); J.A.J.M. Beelen; P.G. Hugenholtz (Paul)

    1984-01-01

    textabstractThe aim of this study was to evaluate the results of predischarge stress testing in the elderly, and to assess the prognostic value of the test during one-year follow-up. The database consisted of 48 patients older than 64 years of age and 109 patients 55-64 years of age, who survived

  18. 49 CFR Appendix E to Part 240 - Recommended Procedures for Conducting Skill Performance Tests

    Science.gov (United States)

    2010-10-01

    ... tailor their testing procedures to the specific operational realities. This appendix contains FRA's..., headlight? —Couple to cars at a safe speed? —Properly control in train slack and buff forces? —Properly use...

  19. Tests on mechanical behavior of 304 L stainless steel under constant stress associated with cyclic strain

    International Nuclear Information System (INIS)

    Lebey, J.; Roche, R.

    1979-01-01

    Mechanical analyses of structures, to be efficient, must incorporate materials behavior data. Among the mechanisms liable to cause collapse, progressive distortion (or ratcheting) has been the subject of only a few basic experiments, most of the investigations being theoretical. In order to get meaningful results to characterize materials behavior, an experimental study on ratcheting of austenitic steels has been undertaken at the C.E.A. This paper gives the first results of tests at room temperature on thin tubes of 304L steel submitted to an axial constant stress (primary stress) to which is added a cyclic shearing strain (secondary stress). The tests cover a large combination of the two loading modes. The main results consist of curves of cumulative iso-deformation in the primary and secondary stress field (Bree type diagrams). Results are given for plastic deformations ranging from 0.1 to 2.5% up to N=100 cycles

  20. Neutron measurements of stresses in a test artifact produced by laser-based additive manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Gnäupel-Herold, Thomas [Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg MD 20899-6102 (United States); Slotwinski, John; Moylan, Shawn [Intelligent Systems Division, National Institute of Standards and Technology, Gaithersburg MD 20899-8220 (United States)

    2014-02-18

    A stainless steel test artifact produced by Direct Metal Laser Sintering and similar to a proposed standardized test artifact was examined using neutron diffraction. The artifact contained a number of structures with different aspect ratios pertaining to wall thickness, height above base plate, and side length. Through spatial resolutions of the order of one millimeter the volumetric distribution of stresses in several was measured. It was found that the stresses peak in the tensile region around 500 MPa near the top surface, with balancing compressive stresses in the interior. The presence of a support structure (a one millimeter high, thin walled, hence weaker, lattice structure deposited on the base plate, followed by a fully dense AM structure) has only minor effects on the stresses.

  1. Stress-testing the Standard Model at the LHC

    CERN Document Server

    2016-01-01

    With the high-energy run of the LHC now underway, and clear manifestations of beyond-Standard-Model physics not yet seen in data from the previous run, the search for new physics at the LHC may be a quest for small deviations with big consequences. If clear signals are present, precise predictions and measurements will again be crucial for extracting the maximum information from the data, as in the case of the Higgs boson. Precision will therefore remain a key theme for particle physics research in the coming years. The conference will provide a forum for experimentalists and theorists to identify the challenges and refine the tools for high-precision tests of the Standard Model and searches for signals of new physics at Run II of the LHC. Topics to be discussed include: pinning down Standard Model corrections to key LHC processes; combining fixed-order QCD calculations with all-order resummations and parton showers; new developments in jet physics concerning jet substructure, associated jets and boosted je...

  2. A New Test Device for Characterization of Mechanical Stress Caused by Packaging Processes

    International Nuclear Information System (INIS)

    Hirsch, Soeren; Doerner, Steffen; Hauptmann, Peter; Schmidt, Bertram

    2006-01-01

    This paper reports on a new method for estimation and minimization of mechanical stress on MEMS sensor and actuator structures due to packaging processes based on flip chip technology. For studying mechanical stress a test chip with silicon membranes was fabricated. A network of piezo-resistive solid state resistors created by diffusion was used to measure the surface tension pattern between adjacent membranes. Finite element method simulation was used to calculate the stress profile and to determine the optimum positions for placing the resistive network

  3. Social Support for Divorced Fathers' Parenting: Testing a Stress-Buffering Model*

    OpenAIRE

    DeGarmo, David S.; Patras, Joshua; Eap, Sopagna

    2008-01-01

    A stress-buffering hypothesis for parenting was tested in a county-representative sample of 218 divorced fathers. Social support for parenting (emergency and nonemergency child care, practical support, financial support) was hypothesized to moderate effects of stress (role overload, coparental conflict, and daily hassles) on fathers’ quality parenting. No custody fathers relied more on relatives compared with custodial fathers, who relied more on new partners for parenting support. No differe...

  4. Work Stress and Alcohol Use: Developing and Testing a Biphasic Self-Medication Model

    OpenAIRE

    Frone, Michael R.

    2016-01-01

    This study developed and tested a moderated-mediation model of work stress and alcohol use, based on the biphasic (stimulant and sedative) effects of alcohol and the self-medication and stress-vulnerability models of alcohol use. The model proposes that exposure to work stressors can increase both negative affect and work fatigue, and that these two sources of strain can subsequently motivate the use of alcohol. However, the relations of negative affect and work fatigue to a...

  5. Stress Testing of the Philips 60W Replacement Lamp L Prize Entry

    Energy Technology Data Exchange (ETDEWEB)

    Poplawski, Michael E.; Ledbetter, Marc R.; Smith, Mark

    2012-04-24

    The Pacific Northwest National Laboratory, operated by Battelle for the U.S. Department of Energy, worked with Intertek to develop a procedure for stress testing medium screw-base light sources. This procedure, composed of alternating stress cycles and performance evaluation, was used to qualitatively compare and contrast the durability and reliability of the Philips 60W replacement lamp L Prize entry with market-proven compact fluorescent lamps (CFLs) with comparable light output and functionality. The stress cycles applied simultaneous combinations of electrical, thermal, vibration, and humidity stresses of increasing magnitude. Performance evaluations measured relative illuminance, x chromaticity and y chromaticity shifts after each stress cycle. The Philips L Prize entry lamps appear to be appreciably more durable than the incumbent energy-efficient technology, as represented by the evaluated CFLs, and with respect to the applied stresses. Through the course of testing, all 15 CFL samples permanently ceased to function as a result of the applied stresses, while only 1 Philips L Prize entry lamp exhibited a failure, the nature of which was minor, non-destructive, and a consequence of a known (and resolved) subcontractor issue. Given that current CFL technology appears to be moderately mature and no Philips L Prize entry failures could be produced within the stress envelope causing 100 percent failure of the benchmark CFLs, it seems that, in this particular implementation, light-emitting diode (LED) technology would be much more durable in the field than current CFL technology. However, the Philips L Prize entry lamps used for testing were carefully designed and built for the competition, while the benchmark CFLs were mass produced for retail sale—a distinction that should be taken into consideration. Further reliability testing on final production samples would be necessary to judge the extent to which the results of this analysis apply to production versions

  6. Socioeconomic status and parenting in ethnic minority families: testing a minority family stress model.

    Science.gov (United States)

    Emmen, Rosanneke A G; Malda, Maike; Mesman, Judi; van Ijzendoorn, Marinus H; Prevoo, Mariëlle J L; Yeniad, Nihal

    2013-12-01

    According to the family stress model (Conger & Donnellan, 2007), low socioeconomic status (SES) predicts less-than-optimal parenting through family stress. Minority families generally come from lower SES backgrounds than majority families, and may experience additional stressors associated with their minority status, such as acculturation stress. The primary goal of this study was to test a minority family stress model with a general family stress pathway, as well as a pathway specific to ethnic minority families. The sample consisted of 107 Turkish-Dutch mothers and their 5- to 6-year-old children, and positive parenting was observed during a 7-min problem-solving task. In addition, mothers reported their daily hassles, psychological distress, and acculturation stress. The relation between SES and positive parenting was partially mediated by both general maternal psychological stress and maternal acculturation stress. Our study contributes to the argument that stressors specific to minority status should be considered in addition to more general demographic and family stressors in understanding parenting behavior in ethnic minority families.

  7. Residual radioactive contamination of the Maralinga range from nuclear weapons tests conducted in 1956 and 1957

    International Nuclear Information System (INIS)

    Cooper, M.B.; Duggleby, J.C.; Kotler, L.H.; Wise, K.N.

    1978-12-01

    Detailed geographical distributions and concentrations of long-lived radionuclides remaining from the major trials of nuclear weapons conducted at Maralinga in 1956 and 1957 are presented. It is shown that residual contamination due to fission products - mainly strontium-90, caesium-137 and europium-155 - are well below levels that could constitute a health hazard to occupants of the area. In the regions near the ground zeroes however, long-lived neutron activation products in soil - mainly cobalt-60 and europium-152 - are present in sufficient abundance to give rise to gamma-radiation dose-rates up to 2 milliroentgen per hour, which exceed maximum recommended dose-rates for continuous occupancy

  8. Interpretation of Cone Penetration Testing in Silty Soils Conducted under Partially Drained Conditions

    DEFF Research Database (Denmark)

    Holmsgaard, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

    2016-01-01

    The standard penetration rate used in cone penetration tests (CPTs) is 20 mm=s, regardless of soil type, which yields fully drained penetration in sand and fully undrained penetration in clay. However, for silty soils that represent an intermediate grain size composition and unique characteristic...

  9. 40 CFR 790.62 - Submission of study plans and conduct of testing.

    Science.gov (United States)

    2010-07-01

    ... contaminants and their concentrations; for in vitro test systems, a description of culture medium and its source; and a summary of expected spontaneous chronic diseases (including tumors), genealogy, and life..., and communicating with the Agency about laboratory inspections and other matters affecting the...

  10. What's in a p? Reassessing best practices for conducting and reporting hypothesis-testing research

    NARCIS (Netherlands)

    Meyer, Klaus E.; van Witteloostuijn, Arjen; Beugelsdijk, Sjoerd

    Social science research has recently been subject to considerable criticism regarding the validity and power of empirical tests published in leading journals, and business scholarship is no exception. Transparency and replicability of empirical findings are essential to build a cumulative body of

  11. What's in a p? Reassessing best practices for conducting and reporting hypothesis-testing research

    NARCIS (Netherlands)

    Meyer, Klaus E.; Van Witteloostuijn, Arjen; Beugelsdijk, Sjoerd

    2017-01-01

    Social science research has recently been subject to considerable criticism regarding the validity and power of empirical tests published in leading journals, and business scholarship is no exception. Transparency and replicability of empirical findings are essential to build a cumulative body of

  12. 40 CFR 63.2362 - When must I conduct subsequent performance tests?

    Science.gov (United States)

    2010-07-01

    ... CATEGORIES National Emission Standards for Hazardous Air Pollutants: Organic Liquids Distribution (Non... equipment and that is loaded with organic liquids at a transfer rack that is subject to control based on the... current certification in accordance with the U.S. DOT pressure test requirements in 49 CFR part 180 for...

  13. 40 CFR 63.5850 - How do I conduct performance tests, performance evaluations, and design evaluations?

    Science.gov (United States)

    2010-07-01

    ...: Reinforced Plastic Composites Production Testing and Initial Compliance Requirements § 63.5850 How do I..., 2C, 2D, 2F or 2G of appendix A to 40 CFR part 60, as appropriate, to measure gas volumetric flow rate... analytical techniques to get an accurate measure of at least 90 percent of the total organic HAP mass...

  14. 40 CFR 63.5719 - How do I conduct a performance test?

    Science.gov (United States)

    2010-07-01

    ..., 2F or 2G of appendix A to 40 CFR part 60, as appropriate, to measure gas volumetric flow rate. (3... analytical techniques to get an accurate measure of at least 90 percent of the total organic HAP mass... device performance test must consist of three runs and each run must last at least 1 hour. The production...

  15. Calibration of Self-Efficacy for Conducting a Chi-Squared Test of Independence

    Science.gov (United States)

    Zimmerman, Whitney Alicia; Goins, Deborah D.

    2015-01-01

    Self-efficacy and knowledge, both concerning the chi-squared test of independence, were examined in education graduate students. Participants rated statements concerning self-efficacy and completed a related knowledge assessment. After completing a demographic survey, participants completed the self-efficacy and knowledge scales a second time.…

  16. Family Stress and Parental Responses to Children’s Negative Emotions: Tests of the Spillover, Crossover, and Compensatory Hypotheses

    Science.gov (United States)

    Nelson, Jackie A.; O’Brien, Marion; Blankson, A. Nayena; Calkins, Susan D.; Keane, Susan P.

    2010-01-01

    The relations between 4 sources of family stress (marital dissatisfaction, home chaos, parental depressive symptoms, and job role dissatisfaction) and the emotion socialization practice of mothers’ and fathers’ responses to children’s negative emotions were examined. Participants included 101 couples with 7-year-old children. Dyadic analyses were conducted using the Actor–Partner Interdependence Model and relations were tested in terms of the spillover, crossover, and compensatory hypotheses. Results suggest that measures of family stress relate to supportive and nonsupportive parental responses, though many of these relations differ by parent gender. The results are discussed in terms of the 3 theoretical hypotheses, all of which are supported to some degree depending on the family stressor examined. PMID:19803603

  17. Family stress and parental responses to children's negative emotions: tests of the spillover, crossover, and compensatory hypotheses.

    Science.gov (United States)

    Nelson, Jackie A; O'Brien, Marion; Blankson, A Nayena; Calkins, Susan D; Keane, Susan P

    2009-10-01

    The relations between 4 sources of family stress (marital dissatisfaction, home chaos, parental depressive symptoms, and job role dissatisfaction) and the emotion socialization practice of mothers' and fathers' responses to children's negative emotions were examined. Participants included 101 couples with 7-year-old children. Dyadic analyses were conducted using the Actor-Partner Interdependence Model and relations were tested in terms of the spillover, crossover, and compensatory hypotheses. Results suggest that measures of family stress relate to supportive and nonsupportive parental responses, though many of these relations differ by parent gender. The results are discussed in terms of the 3 theoretical hypotheses, all of which are supported to some degree depending on the family stressor examined.

  18. Tests on conducted electrical noise on a storage ring dc-dc converter cabinet

    International Nuclear Information System (INIS)

    Carwardine, J.J.

    1994-01-01

    Electrical noise is produced by switching transients in the power supply converters which excite resonances formed by stray capacitance and cable inductance. This noise is present not only on the load cables, but also on ground cables of the magnet and of the converter cabinet. Since there will eventually be a large number of cabinets running at one time, tests were carried out to characterize the noise and to investigate possible techniques for reducing the levels. The tests were carried out on the test girder and converter cabinet set up in 412 area. There were four magnets installed on the girder -- two 0.5m quadrupoles, a 0.8m quadrupole, and a sextupole. These tests were carried out on one of the 0.5m quadrupoles. It should be noted that with this setup, the raw dc power was supplied at around 70V. In the final configuration, a 0.5m quad will be fed from a 40V raw supply. Consequently, the switching transients observed during the tests are likely to be higher than will occur in reality. Noise currents contain two main components: a low frequency component at around 50kHz, and a higher frequency component at around lMHz. It is the latter component which is of primary concern. Currents measured on the dc load cables typically were around one ampere, while currents into the building ground system were only a few tens of milliamps. Several methods were used to try reducing the noise currents, but only the addition of a series impedance was successful -- other methods either had no effect or increased the ground currents

  19. The Effect of Being Aerobically Active vs. Inactive on Cutaneous Vascular Conductance during Local Heat Stress in an Older Population

    Directory of Open Access Journals (Sweden)

    Ulrike H. Mitchell

    2017-10-01

    Full Text Available Objective: To test the hypothesis that long- term aerobically trained elderly individuals have a greater amount of bioavailable nitric oxide (NO and have a larger cutaneous vasodilation during local heat stress compared to their inactive elderly counterparts.Methods: Eight aerobically trained and 8 inactive older men (>60 years old participated in this study. NO bioavailability in blood and intradermal dialysate were measured with an ozone based chemiluminescence NO analyzer. Cutaneous vasodilator response to local heating was obtained using laser Doppler velocimetry.Results: Whole blood NO were similar in older- trained and inactive subjects (0.75 ± 0.56 and 0.38 ± 0.32 μM, respectively; Mann–Whitney, p = 0.153, as was intradermal dialysate NO before (7.82 ± 6.32 and 4.18 ± 1.89 μM, respectively and after local heating (7.16 ± 6.27 and 5.88 ± 3.97 μM, respectively, p = 0.354. The cutaneous vasodilator response of the older- inactive group was smaller than the older- trained group [Group-Time interaction, F(24, 264 = 12.0, p < 0.0001]. When compared to a young group the peak vasodilator response of the older- trained subjects was similar. However, the time to initial dilation was 3.1 and 2.2 times longer (p < 0.05 in older- inactive and older- trained subjects, respectively, compared to young subjects.Conclusions: Our data support the hypothesis that the age-related reductions in cutaneous vasodilation can possibly be restored by maintaining an aerobic training regimen (at least 3 years. However, some residual effects of aging remain, specifically a delayed cutaneous vasodilator response to local heating is still present in active older adults. We found no evidence for an increase in systemic or local NO-bioavailability with an extended commitment to aerobic fitness.

  20. The Effect of Being Aerobically Active vs. Inactive on Cutaneous Vascular Conductance during Local Heat Stress in an Older Population.

    Science.gov (United States)

    Mitchell, Ulrike H; Burton, Samantha; Gordon, Christopher; Mack, Gary W

    2017-01-01

    Objective: To test the hypothesis that long- term aerobically trained elderly individuals have a greater amount of bioavailable nitric oxide (NO) and have a larger cutaneous vasodilation during local heat stress compared to their inactive elderly counterparts. Methods: Eight aerobically trained and 8 inactive older men (>60 years old) participated in this study. NO bioavailability in blood and intradermal dialysate were measured with an ozone based chemiluminescence NO analyzer. Cutaneous vasodilator response to local heating was obtained using laser Doppler velocimetry. Results: Whole blood NO were similar in older- trained and inactive subjects (0.75 ± 0.56 and 0.38 ± 0.32 μM, respectively; Mann-Whitney, p = 0.153), as was intradermal dialysate NO before (7.82 ± 6.32 and 4.18 ± 1.89 μM, respectively) and after local heating (7.16 ± 6.27 and 5.88 ± 3.97 μM, respectively, p = 0.354). The cutaneous vasodilator response of the older- inactive group was smaller than the older- trained group [Group-Time interaction, F (24, 264) = 12.0, p < 0.0001]. When compared to a young group the peak vasodilator response of the older- trained subjects was similar. However, the time to initial dilation was 3.1 and 2.2 times longer ( p < 0.05) in older- inactive and older- trained subjects, respectively, compared to young subjects. Conclusions: Our data support the hypothesis that the age-related reductions in cutaneous vasodilation can possibly be restored by maintaining an aerobic training regimen (at least 3 years). However, some residual effects of aging remain, specifically a delayed cutaneous vasodilator response to local heating is still present in active older adults. We found no evidence for an increase in systemic or local NO-bioavailability with an extended commitment to aerobic fitness.

  1. Synthetic sea water - An improved stress corrosion test medium for aluminum alloys

    Science.gov (United States)

    Humphries, T. S.; Nelson, E. E.

    1973-01-01

    A major problem in evaluating the stress corrosion cracking resistance of aluminum alloys by alternate immersion in 3.5 percent salt (NaCl) water is excessive pitting corrosion. Several methods were examined to eliminate this problem and to find an improved accelerated test medium. These included the addition of chromate inhibitors, surface treatment of specimens, and immersion in synthetic sea water. The results indicate that alternate immersion in synthetic sea water is a very promising stress corrosion test medium. Neither chromate inhibitors nor surface treatment (anodize and alodine) of the aluminum specimens improved the performance of alternate immersion in 3.5 percent salt water sufficiently to be classified as an effective stress corrosion test method.

  2. Characterization Of Flow Stress Of Different AA6082 Alloys By Means Of Hot Torsion Test

    International Nuclear Information System (INIS)

    Donati, Lorenzo; El Mehtedi, Mohamad

    2011-01-01

    FEM simulations are become the most powerful tools in order to optimize the different aspects of the extrusion process and an accurate flow stress definition of the alloy is a prerequisite for a reliable effectiveness of the simulation. In the paper the determination of flow stress by means of hot torsion test is initially presented and discussed: the several approximations that are usually introduced in flow stress computation are described and computed for an AA6082 alloy in order to evidence the final effect on curves shapes. The procedure for regressing the parameters of the sinhyperbolic flow stress definition is described in detailed and applied to the described results. Then four different alloys, extracted by different casting batches but all namely belonging to the 6082 class, were hot torsion tested in comparable levels of temperature and strain rate up to specimen failure. The results are analyzed and discussed in order to understand if a mean flow stress behavior can be identified for the whole material class at the different tested conditions or if specific testing conditions (chemical composition of the alloy, specimen shape, etc) influence the materials properties to a higher degree.

  3. Experimental stress analysis and fatigue tests of five 24-in. NPS ANSI Standard B16.9 tees

    International Nuclear Information System (INIS)

    Moore, S.E.; Hayes, J.K.; Weed, R.A.

    1985-03-01

    Experimental stress analyses and low-cycle fatigue tests of five 24-in. nominal pipe size American National Standards Institute (ANSI) Standard B16.9 forged tees are documented in this report. The tees, designated as Oak Ridge National Laboratory tees T10, T11, T12, T13, and T16, were tested under subcontract at Combustion Engineering, Inc. in Chattanooga, Tennessee. Experimental stress analyses were conducted for 12 individual loadings on each tee. Each test model was instrumented with approx. 225, 1/8-in. three-gage, 45 0 strain rosettes on the inside and outside surfaces; and 6 linear variable differential transformers mounted on special nonflexible holding frames for measuring deflections and rotations of the pipe extensions. Following completion of the strain-gate tests, each tee was fatigue tested to failure with either a fully reversed displacement controlled in-plane bending moment on the branch or a cyclic internal pressure that ranged from a value slightly above zero to about 90% of the nominal yield pressure of the pipe extensions

  4. Experimental stress analysis and fatigue tests of five 24-in. NPS ANSI Standard B16. 9 tees. [PWR; BWR

    Energy Technology Data Exchange (ETDEWEB)

    Moore, S.E.; Hayes, J.K.; Weed, R.A.

    1985-03-01

    Experimental stress analyses and low-cycle fatigue tests of five 24-in. nominal pipe size American National Standards Institute (ANSI) Standard B16.9 forged tees are documented in this report. The tees, designated as Oak Ridge National Laboratory tees T10, T11, T12, T13, and T16, were tested under subcontract at Combustion Engineering, Inc. in Chattanooga, Tennessee. Experimental stress analyses were conducted for 12 individual loadings on each tee. Each test model was instrumented with approx. 225, 1/8-in. three-gage, 45/sup 0/ strain rosettes on the inside and outside surfaces; and 6 linear variable differential transformers mounted on special nonflexible holding frames for measuring deflections and rotations of the pipe extensions. Following completion of the strain-gate tests, each tee was fatigue tested to failure with either a fully reversed displacement controlled in-plane bending moment on the branch or a cyclic internal pressure that ranged from a value slightly above zero to about 90% of the nominal yield pressure of the pipe extensions.

  5. Applicability study on a ceramic filter with hot-test conducted in a BWR plant

    International Nuclear Information System (INIS)

    Yamada, K.; Shirai, T.; Wada, M.; Nakamizo, H.

    1991-01-01

    Radioactive crud removal and filtration performance recovery by backwashing were examined with a BWR plant pool water using a ceramic filter element, 0.1 micron in nominal pore size and 0.2m 2 in filtration area. Totally 1114 hours filter operation were accumulated. Ten backwashings were accomplished during the test period. The following results were obtained. (1) Radioactive crud concentration in the filter effluent remained below 10 5 Bq/m 3 . (2) Both pressure loss through the filter and dose rate at the filter vessel surface were recovered to the initial level by each backwashing. The surface dose rate after backwashing was approximately 0.01mSv/h. According to these test results, it is confirmed that the ceramic filter is appropriate for the treatment of highly crud concentrated radioactive liquid, which is generated in nuclear facilities, such as spent fuel reprocessing plants. (author)

  6. Preliminary data from lithium hydride ablation tests conducted by NASA, Ames Research Center

    International Nuclear Information System (INIS)

    Elliott, R.D.

    1970-01-01

    A series of ablation tests of lithium hydride has been made by NASA-Ames in one of their high-enthalpy arc-heated wind tunnels. Two-inch diameter cylindrical samples of the hydride, supplied by A. I., were subjected to heating on their ends for time periods up to 10 seconds. After each test, the amount of material removed from each sample was measured. The rates of loss of material were correlated with the heat input rates in terms of a heat of ablation, which ranged from 2100 to 3500 Btu/lb. The higher values were obtained when the hydride contained a matrix such as steel honeycomb of steel wool. (U.S.)

  7. Efficiency of the Needle Probe Test for Evaluation of Thermal Conductivity of Composite Materials: Two-Scale Analysis

    Directory of Open Access Journals (Sweden)

    Łydżba Dariusz

    2014-03-01

    Full Text Available The needle probe test, as a thermal conductivity measurement method, has become very popular in recent years. In the present study, the efficiency of this methodology, for the case of composite materials, is investigated based on the numerical simulations. The material under study is a two-phase composite with periodic microstructure of “matrix-inclusion” type. Two-scale analysis, incorporating micromechanics approach, is performed. First, the effective thermal conductivity of the composite considered is found by the solution of the appropriate boundary value problem stated for the single unit cell. Next, numerical simulations of the needle probe test are carried out. In this case, two different locations of the measuring sensor are considered. It is shown that the “equivalent” conductivity, derived from the probe test, is strongly affected by the location of the sensor. Moreover, comparing the results obtained for different scales, one can notice that the “equivalent” conductivity cannot be interpreted as the effective one for the composites considered. Hence, a crude approximation of the effective property is proposed based on the volume fractions of constituents and the equivalent conductivities derived from different sensor locations.

  8. Shape and compliance of endothelial cells after shear stress in vitro or from different aortic regions: scanning ion conductance microscopy study.

    Directory of Open Access Journals (Sweden)

    Claire M F Potter

    Full Text Available To measure the elongation and compliance of endothelial cells subjected to different patterns of shear stress in vitro, and to compare these parameters with the elongation and compliance of endothelial cells from different regions of the intact aorta.Porcine aortic endothelial cells were cultured for 6 days under static conditions or on an orbital shaker. The shaker generated a wave of medium, inducing pulsatile shear stress with a preferred orientation at the edge of the well or steadier shear stress with changing orientation at its centre. The topography and compliance of these cells and cells from the inner and outer curvature of ex vivo porcine aortic arches were measured by scanning ion conductance microscopy (SICM.Cells cultured under oriented shear stress were more elongated and less compliant than cells grown under static conditions or under shear stress with no preferred orientation. Cells from the outer curvature of the aorta were more elongated and less compliant than cells from the inner curvature.The elongation and compliance of cultured endothelial cells vary according to the pattern of applied shear stress, and are inversely correlated. A similar inverse correlation occurs in the aortic arch, with variation between regions thought to experience different haemodynamic stresses.

  9. Self-esteem, narcissism, and stressful life events: Testing for selection and socialization.

    Science.gov (United States)

    Orth, Ulrich; Luciano, Eva C

    2015-10-01

    We examined whether self-esteem and narcissism predict the occurrence of stressful life events (i.e., selection) and whether stressful life events predict change in self-esteem and narcissism (i.e., socialization). The analyses were based on longitudinal data from 2 studies, including samples of 328 young adults (Study 1) and 371 adults (Study 2). The effects of self-esteem and narcissism were mutually controlled for each other and, moreover, controlled for effects of depression. After conducting the study-level analyses, we meta-analytically aggregated the findings. Self-esteem had a selection effect, suggesting that low self-esteem led to the occurrence of stressful life events; however, this effect became nonsignificant when depression was controlled for. Regardless of whether depression was controlled for or not, narcissism had a selection effect, suggesting that high narcissism led to the occurrence of stressful life events. Moreover, stressful life events had a socialization effect on self-esteem, but not on narcissism, suggesting that the occurrence of stressful life events decreased self-esteem. Analyses of trait-state models indicated that narcissism consisted almost exclusively of perfectly stable trait variance, providing a possible explanation for the absence of socialization effects on narcissism. The findings have significant implications because they suggest that a person's level of narcissism influences whether stressful life events occur, and that self-esteem is shaped by the occurrence of stressful life events. Moreover, we discuss the possibility that depression mediates the selection effect of low self-esteem on stressful life events. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

  10. Stress corrosion crack initiation of Zircaloy-4 cladding tubes in an iodine vapor environment during creep, relaxation, and constant strain rate tests

    Science.gov (United States)

    Jezequel, T.; Auzoux, Q.; Le Boulch, D.; Bono, M.; Andrieu, E.; Blanc, C.; Chabretou, V.; Mozzani, N.; Rautenberg, M.

    2018-02-01

    During accidental power transient conditions with Pellet Cladding Interaction (PCI), the synergistic effect of the stress and strain imposed on the cladding by thermal expansion of the fuel, and corrosion by iodine released as a fission product, may lead to cladding failure by Stress Corrosion Cracking (SCC). In this study, internal pressure tests were conducted on unirradiated cold-worked stress-relieved Zircaloy-4 cladding tubes in an iodine vapor environment. The goal was to investigate the influence of loading type (constant pressure tests, constant circumferential strain rate tests, or constant circumferential strain tests) and test temperature (320, 350, or 380 °C) on iodine-induced stress corrosion cracking (I-SCC). The experimental results obtained with different loading types were consistent with each other. The apparent threshold hoop stress for I-SCC was found to be independent of the test temperature. SEM micrographs of the tested samples showed many pits distributed over the inner surface, which tended to coalesce into large pits in which a microcrack could initiate. A model for the time-to-failure of a cladding tube was developed using finite element simulations of the viscoplastic mechanical behavior of the material and a modified Kachanov's damage growth model. The times-to-failure predicted by this model are consistent with the experimental data.

  11. Towards an improved and more flexible representation of water stress in coupled photosynthesis-stomatal conductance models; implications for simulated land surface fluxes and variables at various spatiotemporal scales

    Science.gov (United States)

    Egea, G.; Verhoef, A.; Vidale, P. L.; Black, E.; Van den Hoof, C.

    2012-04-01

    Coupled photosynthesis-stomatal conductance (A-gs) models are commonly used in ecosystem models to represent the exchange rate of CO2 and H2O between vegetation and the atmosphere. The ways these models account for water stress differ greatly among modelling schemes. This study provides insight into the impact of contrasting model configurations of water stress on the simulated leaf-level values of net photosynthesis (A), stomatal conductance (gs), the functional relationship among them and their ratio, the intrinsic water use efficiency (A/gs), as soil dries. A simple, yet versatile, normalized soil moisture dependent function was used to account for the effects of water stress on gs, on mesophyll conductance (gm ) and on the biochemical capacity (Egea et al., 2011). Model output was compared to leaf-level values obtained from the literature. The sensitivity analyses emphasized the necessity to combine both stomatal and non-stomatal limitations of A in coupled A-gs models to accurately capture the observed functional relationships A vs. gs and A/gs vs. gs in response to drought. Accounting for water stress in coupled A-gs models by imposing either stomatal or biochemical limitations of A, as commonly practiced in most ecosystem models, failed to reproduce the observed functional relationship between key leaf gas exchange attributes. A quantitative limitation analysis revealed that the general pattern of C3 photosynthetic response to water stress can be represented in coupled A-gs models by imposing the highest limitation strength to mesophyll conductance, then to stomatal conductance and finally to the biochemical capacity. This more realistic representation of soil water stress on the simulated leaf-level values of A and gs was embedded in the JULES (Joint UK Land Environment Simulator; Best et al., 2011), model and tested for a number of vegetation types, for which driving and flux verification data were available. These simulations provide an insight into the

  12. Skin conductance biofeedback training in adults with drug-resistant temporal lobe epilepsy and stress-triggered seizures: a proof-of-concept study.

    Science.gov (United States)

    Micoulaud-Franchi, Jean-Arthur; Kotwas, Iliana; Lanteaume, Laura; Berthet, Christelle; Bastien, Mireille; Vion-Dury, Jean; McGonigal, Aileen; Bartolomei, Fabrice

    2014-12-01

    The present proof-of-concept study investigated the feasibility of skin conductance biofeedback training in reducing seizures in adults with drug-resistant temporal lobe epilepsy (TLE), whose seizures are triggered by stress. Skin conductance biofeedback aims to increase levels of peripheral sympathetic arousal in order to reduce cortical excitability. This might seem somewhat counterintuitive, since such autonomic arousal may also be associated with increased stress and anxiety. Thus, this sought to verify that patients with TLE and stress-triggered seizures are not worsened in terms of stress, anxiety, and negative emotional response to this nonpharmacological treatment. Eleven patients with drug-resistant TLE with seizures triggered by stress were treated with 12 sessions of biofeedback. Patients did not worsen on cognitive evaluation of attentional biases towards negative emotional stimuli (P>.05) or on psychometric evaluation with state anxiety inventory (P = .059); in addition, a significant improvement was found in the Negative Affect Schedule (P = .014) and in the Beck Depression Inventory (P = .009). Biofeedback training significantly reduced seizure frequency with a mean reduction of -48.61% (SD = 27.79) (P = .005). There was a correlation between the mean change in skin conductance activity over the biofeedback treatment and the reduction of seizure frequency (r(11) = .62, P = .042). Thus, the skin conductance biofeedback used in the present study, which teaches patients to achieve an increased level of peripheral sympathetic arousal, was a well-tolerated nonpharmacological treatment. Further, well-controlled studies are needed to confirm the therapeutic value of this nonpharmacological treatment in reducing seizures in adults with drug-resistant TLE with seizures triggered by stress. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. Determination of hydraulic conductivity coefficient in NSD site, Serpong, based on in-situ permeability test method

    International Nuclear Information System (INIS)

    Heri Syaeful; Sucipta

    2013-01-01

    In line with the increase of amount of radioactive waste, PTLR-BATAN plans to build the Near Surface Disposal (NSD) facility, especially in the preliminary stages is the Demo Plant of NSD facility. NSD is a low to medium level radioactive waste storage concept. Most important aspect in the site study for planning NSD is hydrogeological aspect especially related to the migration of radionuclides to the environment. In the study of radionuclide migration, a preliminary parameter which is required to know is the hydraulic conductivity in order to deliver the soil and rock hydraulic conductivity values in the site then conducted the in-situ permeability test. Based on the test, obtained soil and rock hydraulic conductivity values ranging from 10 -6 to 10 -2 cm/sec. The greatest hydraulic conductivity value located in the gravelly silt soil units which is in the site, constitute as aquifer, with depth ranging from 8 - 24 m, with hydraulic conductivity value reached 10 -2 cm/sec. (author)

  14. Stress test with adenosine in cerebral perfusion imaging for the diagnosis of ischemic cerebrovascular disease

    International Nuclear Information System (INIS)

    Yuan Gengbiao; Kuang Anren; Chen Xuehong; Li Xihuan; Feng Jianzhong

    2004-01-01

    Objective: This study purpose is to evaluate cerebrovascular response and reserve capacity (CVR, CVRC) by stress test with adenosine in cerebral perfusion imaging for the diagnosis of ischemic cerebrovascular diseases. Methods There were 25 patients suffered from transient ischemia attack and 16 patients suffered from occlusive cerebral artery in this study. The rest cerebral perfusion imaging was obtained 30 minutes post-injection of 99mTC-ethylene cysteinate dimmer. After 2-5 days, adenosine stress tests were performed. Adenosine (0.14 mg/kg min) was administered intravenously 3 minutes pre-injection of 99mTC-ECD.Under same condition, the rest and stress tests of cerebral perfusion imaging were performed. By visual and semiquantitative analysis, the results of the rest/stress imaging were divided into the following four patterns: A: The stress imaging showed an expand areas of hypoperfusion, asymmetry index (AI) was decreased; B: Rest imaging was normal but new hypoperfused areas appeared with AI index declining in stress test; C: The hypoperfused areas were decreased or disappeared in size with AI index increasing in stress test; D: No changes showed in cerebral perfusion imaging patterns and Al index between rest and stress tests. AI index was ratio of radio account of interest regions than average radio account of cerebella. Results It was found that A, B, C and D type were 24%,12%,56% and 8% respectively in the group of transient ischemia attack patients, and 31%,44%, 19% and 6% respectively in the group of occlusive cerebrovascular patients. In rest test, of 41 patients of cerebrovascular disease, there were 28 cases decreased of radio uptake, moreover in stress test, there were 38 case decreased of radio uptake, positive rate were 68.29% and 92.68% respectively. Compared to X±SD of AI index of rest/stress test, it is found to increasing and being significant statistics (p<0.01, Spass 8.0 statistics software). Conclusion: Adenosinal-induced vasodilatation

  15. Report on Beryllium Strength Experiments Conducted at the TA-55 40 mm Impact Test Facility, Fiscal Year 2017

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, William Wyatt [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hollowell, Benjamin Charles [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Todd P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Owens, Charles Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Rivera, Joseph Lee [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-10

    A series of experiments is currently in progress at eth 40 mm Impact Test Facility (ITF), located at TA-55, to understand the strength behavior of Beryllium metal at elevated temperature and pressure. In FY 2017, three experiments were conducted as a part of this project.

  16. The Influence of Maternal Acculturation, Neighborhood Disadvantage, and Parenting on Chinese American Adolescents' Conduct Problems: Testing the Segmented Assimilation Hypothesis

    Science.gov (United States)

    Liu, Lisa L.; Lau, Anna S.; Chen, Angela Chia-Chen; Dinh, Khanh T.; Kim, Su Yeong

    2009-01-01

    Associations among neighborhood disadvantage, maternal acculturation, parenting and conduct problems were investigated in a sample of 444 Chinese American adolescents. Adolescents (54% female, 46% male) ranged from 12 to 15 years of age (mean age = 13.0 years). Multilevel modeling was employed to test the hypothesis that the association between…

  17. Physical Stress Echocardiography: Prediction of Mortality and Cardiac Events in Patients with Exercise Test showing Ischemia

    Directory of Open Access Journals (Sweden)

    Ana Carla Pereira de Araujo

    2014-11-01

    Full Text Available Background: Studies have demonstrated the diagnostic accuracy and prognostic value of physical stress echocardiography in coronary artery disease. However, the prediction of mortality and major cardiac events in patients with exercise test positive for myocardial ischemia is limited. Objective: To evaluate the effectiveness of physical stress echocardiography in the prediction of mortality and major cardiac events in patients with exercise test positive for myocardial ischemia. Methods: This is a retrospective cohort in which 866 consecutive patients with exercise test positive for myocardial ischemia, and who underwent physical stress echocardiography were studied. Patients were divided into two groups: with physical stress echocardiography negative (G1 or positive (G2 for myocardial ischemia. The endpoints analyzed were all-cause mortality and major cardiac events, defined as cardiac death and non-fatal acute myocardial infarction. Results: G2 comprised 205 patients (23.7%. During the mean 85.6 ± 15.0-month follow-up, there were 26 deaths, of which six were cardiac deaths, and 25 non-fatal myocardial infarction cases. The independent predictors of mortality were: age, diabetes mellitus, and positive physical stress echocardiography (hazard ratio: 2.69; 95% confidence interval: 1.20 - 6.01; p = 0.016. The independent predictors of major cardiac events were: age, previous coronary artery disease, positive physical stress echocardiography (hazard ratio: 2.75; 95% confidence interval: 1.15 - 6.53; p = 0.022 and absence of a 10% increase in ejection fraction. All-cause mortality and the incidence of major cardiac events were significantly higher in G2 (p < 0. 001 and p = 0.001, respectively. Conclusion: Physical stress echocardiography provides additional prognostic information in patients with exercise test positive for myocardial ischemia.

  18. Verification of intraspecimen method using constant stress tension test of sensitized alloy 600

    International Nuclear Information System (INIS)

    Lee, Seung Ki; Choi, Hoi Su; Hwang, Il Soon

    2005-01-01

    Stress corrosion cracking (SCC) occurring at the Nibase alloy 600 used in the nuclear power plant SG tubes and CRDM penetration nozzles had been reported after long-term operation in the harsh environment. Intraspecimen method was developed to predict the SCC initiation time statistically. [1] By dividing a test area into a number of smaller regions (intraspecimens) having homogeneous physical and chemical condition each SCC initiation in each intraspecimen could be counted as an independent outcome to provide enough number of statistical data. Earlier work of intraspecimen method had many problems in test method and didn't agree with Weibull statistics which is the theoretical base of intraspecimen method. The test method is improved in this intraspecimen test. To find out the root causes of the problems in earlier work and improve the accuracy of intraspecimen method, two kinds of materials are introduced, which are different in grain size but same in chemical composition. Ni-base alloy 600, heat no. J313 and J323 are used as test materials. Specimens of sensitized Alloy 600 are tested under the condition of constant tensile stress and well defined chemical environment therefore we can easily observe typical intergranular stress corrosion cracking (IGSCC). Material with finer grain (J323) showed the areadependence in agreement with theoretical prediction. But material with coarser grain (J313) did not show any significant area-dependence. While SCC initiates earlier at grain boundaries that are oriented close to normal to the stress axis, crack initiation time showed no correlation with grain boundary misorientation estimated by Electron Back Scattered Diffraction (EBSD). From the SCC initiation tests with two test materials, it is concluded that the number of grains in an intraspecimen, degree of sensitization and uniform stress distribution are important parameters to meet Weibull statistics

  19. Cardiopulmonary exercise testing (CPET) in the United Kingdom-a national survey of the structure, conduct, interpretation and funding.

    Science.gov (United States)

    Reeves, T; Bates, S; Sharp, T; Richardson, K; Bali, S; Plumb, J; Anderson, H; Prentis, J; Swart, M; Levett, D Z H

    2018-01-01

    Cardiopulmonary exercise testing (CPET) is an exercise stress test with concomitant expired gas analysis that provides an objective, non-invasive measure of functional capacity under stress. CPET-derived variables predict postoperative morbidity and mortality after major abdominal and thoracic surgery. Two previous surveys have reported increasing utilisation of CPET preoperatively in England. We aimed to evaluate current CPET practice in the UK, to identify who performs CPET, how it is performed, how the data generated are used and the funding models. All anaesthetic departments in trusts with adult elective surgery in the UK were contacted by telephone to obtain contacts for their pre-assessment and CPET service leads. An online survey was sent to all leads between November 2016 and March 2017. The response rate to the online survey was 73.1% (144/197) with 68.1% (98/144) reporting an established clinical service and 3.5% (5/144) setting up a service. Approximately 30,000 tests are performed a year with 93.0% (80/86) using cycle ergometry. Colorectal surgical patients are the most frequently tested (89.5%, 77/86). The majority of tests are performed and interpreted by anaesthetists. There is variability in the methods of interpretation and reporting of CPET and limited external validation of results. This survey has identified the continued expansion of perioperative CPET services in the UK which have doubled since 2011. The vast majority of CPET tests are performed and reported by anaesthetists. It has highlighted variation in practice and a lack of standardised reporting implying a need for practice guidelines and standardised training to ensure high-quality data to inform perioperative decision making.

  20. Effects of stress on memory in children and adolescents: testing causal connections.

    Science.gov (United States)

    Quas, Jodi A; Rush, Elizabeth B; Yim, Ilona S; Nikolayev, Mariya

    2014-01-01

    Although a sizeable body of research has examined children's memory for stressful prior experiences, relatively few studies have experimentally manipulated stress during a to-be-remembered event to draw causal inferences about the effects of stress, especially across wide age ranges. We exposed children and adolescents to a more or a less arousing version of the Trier Social Stress Test-Modified (TSST-M), a widely used laboratory stress task. Two weeks later, we tested their memory for what happened. Interviewers behaved in a supportive or non-supportive manner. In adolescents, those who completed the high-arousal TSST-M provided fewer correct responses to recognition questions and fewer incorrect responses to misleading questions for which any answer would have been incorrect, compared to those who completed the lower-arousal TSST-M. Thus, arousal seemed to have reduced the adolescents' willingness to answer questions rather than having influenced their memory per se. In children, across TSST-M conditions, greater physiological arousal during the TSST-M predicted enhanced recall. Finally, interviewer support reduced the amount of factual information provided in free recall but increased correct responses to misleading questions. Results highlight the complex ways in which event stress and interviewer demeanour shape recounting of prior experiences across development.

  1. Effect of α-lipoic acid combined with nerve growth factor on bone metabolism, oxidative stress and nerve conduction function after femoral fracture surgery

    Directory of Open Access Journals (Sweden)

    An-Jun Cao

    2017-11-01

    Full Text Available Objective: To discuss the effect of 毩 -lipoic acid combined with nerve growth factor on bone metabolism, oxidative stress and nerve conduction function after femoral fracture surgery. Methods: A total of 110 patients with femoral fracture who received surgical treatment in the hospital between January 2015 and January 2017 were collected and divided into the control group (n=55 and study group (n=55 by random number table. Control group received postoperative nerve growth factor therapy, and study group received postoperative 毩 -lipoic acid combined with nerve growth factor therapy. The differences in the contents of bone metabolism and oxidative stress indexes as well as the levels of nerve conduction function indexes were compared between the two groups before and after treatment. Results: Before treatment, the differences in the contents of bone metabolism and oxidative stress indexes as well as the levels of nerve conduction function indexes were not statistically significant between the two groups. After treatment, serum bone metabolism indexes BGP and PⅠNP contents of study group were higher than those of control group while CTX-Ⅰ and TRAP contents were lower than those of control group; serum oxidative stress indexes TAC, CAT and SOD contents of study group were higher than those of control group while MDA content was lower than that of control group; limb nerve conduction velocity SCV and MCV levels of study group were higher than those of control group. Conclusion: 毩 -lipoic acid combined with nerve growth factor therapy after femoral fracture surgery can effectively balance osteoblast/ osteoclast activity, reduce oxidative stress and improve limb nerve conduction velocity.

  2. Randomized test of an implementation intention-based tool to reduce stress-induced eating.

    Science.gov (United States)

    O'Connor, Daryl B; Armitage, Christopher J; Ferguson, Eamonn

    2015-06-01

    Stress may indirectly contribute to disease (e.g. cardiovascular disease, cancer) by producing deleterious changes to diet. The purpose of this study was to test the effectiveness of a stress management support (SMS) tool to reduce stress-related unhealthy snacking and to promote stress-related healthy snacking. Participants were randomized to complete a SMS tool with instruction to link stressful situations with healthy snack alternatives (experimental) or a SMS tool without a linking instruction (control). On-line daily reports of stressors and snacking were completed for 7 days. Daily stressors were associated with unhealthy snack consumption in the control condition but not in the experimental condition. Participants highly motivated towards healthy eating consumed a greater number of healthy snacks in the experimental condition on stressful days compared to participants in the experimental condition with low and mean levels of motivation. This tool is an effective, theory driven, intervention that helps to protect against stress-induced high-calorie snack consumption.

  3. Design of PH-based accelerated life testing plans under multiple-stress-type

    International Nuclear Information System (INIS)

    Elsayed, E.A.; Zhang Hao

    2007-01-01

    Accelerated life testing (ALT) is used to obtain failure time data quickly under high stress levels in order to predict product life performance under design stress conditions. Most of the previous work on designing ALT plans is focused on the application of a single stress. However, as components or products become more reliable due to technological advances, it becomes more difficult to obtain significant amount of failure data within reasonable amount of time using single stress only. Multiple-stress-type ALTs have been employed as a means of overcoming such difficulties. In this paper, we design optimum multiple-stress-type ALT plans based on the proportional hazards model. The optimum combinations of stresses and their levels are determined such that the variance of the reliability estimate of the product over a specified period of time is minimized. The use of the model is illustrated using numerical example, and sensitivity analysis shows that the resultant optimum ALT plan is robust to the deviation in model parameters

  4. A test procedure for determining the influence of stress ratio on fatigue crack growth

    Science.gov (United States)

    Fitzgerald, J. H.; Wei, R. P.

    1974-01-01

    A test procedure is outlined by which the rate of fatigue crack growth over a range of stress ratios and stress intensities can be determined expeditiously using a small number of specimens. This procedure was developed to avoid or circumvent the effects of load interactions on fatigue crack growth, and was used to develop data on a mill annealed Ti-6Al-4V alloy plate. Experimental data suggest that the rates of fatigue crack growth among the various stress ratios may be correlated in terms of an effective stress intensity range at given values of K max. This procedure is not to be used, however, for determining the corrosion fatigue crack growth characteristics of alloys when nonsteady-state effects are significant.

  5. Task 2 - Limits for High-Frequency Conducted Susceptibility Testing - CS114 (NRC-HQ-60-14-D-0015)

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Richard Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ewing, Paul D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Moses, Rebecca J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    A principal focus of Task 2 under this project was for ORNL to evaluate the basis for susceptibility testing against high-frequency conducted interference and to establish recommendations to resolve concerns about the severity of test limits for the conducted susceptibility (CS) test, CS114, from MIL-STD-461. The primary concern about the test limit has been characterized by the EPRI EMI Working Group in the following terms: Demonstrating compliance with the CS114 test limits recommended in TR-102323 has proven to be problematic, even for components that have been tested to commercial standards and demonstrated proper operation in industrial applications [6]. Specifically, EPRI notes that the CS114 limits approved in regulatory documents are significantly higher than those invoked by the US military and similar commercial standards in the frequency range below 200 kHz. For this task, ORNL evaluated the original approach to establishing the test limit, EPRI technical findings from a review of the limit, and the regulatory basis through which the currently approved limits were accepted. Based on this analysis, strategies have been developed regarding changes to the CS114 limit that can resolve the technical concerns raised by the industry. Guided by the principles that reasonable assurance of safety must not be compromised but excessive conservatism should be reduced, recommendations on a suitable basis for a revised limit have been developed and can be incorporated into the planned Revision 2 of RG 1.180.

  6. A study on stress analysis of small punch-creep test and its experimental correlations with uniaxial-creep test

    International Nuclear Information System (INIS)

    Lee, Song In; Baek, Seoung Se; Kwon, Il Hyun; Yu, Hyo Sun

    2002-01-01

    A basic research was performed to ensure the usefulness of Small Punch-creep(SP-creep) test for residual life evaluation of heat resistant components effectively. This paper presents analytical results of initial stress and strain distributions in SP specimen caused by constant loading for SP-creep test and its experimental correlations with uniaxial creep(Ten-creep) test on 9CrlMoVNb steel. It was shown that the initial maximum equivalent stress, σ eq · max from FE analysis was correlated with steady-state equivalent creep strain rate, ε qf-ss , rupture time, t r , activation energy, Q and Larson-Miller parameter, LMP during SP-creep deformation. The simple correlation laws, σ SP - σ TEN , P SP -σ TEN and Q SP -Q TEN adopted to established a quantitative correlation between SP-creep and Ten-creep test data. Especially, the activation energy obtained from SP-creep test is linearly related to that from Ten-creep test at 650 deg. C as follows : Q SP-P =1.37 Q TEN , Q SP-σ =1.53 Q TEN

  7. Stress corrosion cracking tests on electron beam welded carbon steel specimens in carbonate-bicarbonate solution

    International Nuclear Information System (INIS)

    Parkins, R.N.

    1985-04-01

    Stress corrosion cracking tests have been performed on tapered carbon steel test pieces containing electron beam welds with a view to defining susceptibility to such cracking in a carbonate-bicarbonate solution at 90 C and an appropriate electrode potential. The tests involved applying cyclic loads to the specimens and it is shown that the threshold stress for cracking reduces linearly with increase in the magnitude of the cyclic load component. Extrapolation of these trends to zero fluctuating stress indicates static load threshold stresses in the vicinity of the yield stress (i.e. about 300 N/mm 2 for parent plate without a weld, 400 N/mm 2 for specimens with welds on one side only and 600 N/mm 2 for specimens having welds penetrating through the thickness of the specimen). The averages of the maximum crack velocities observed were least for parent plate material and greatest for weld metal, the former being essentially intergranular in morphology and the latter mostly transgranular, with heat affected zone material being intermediate between these extremes. (author)

  8. Cortisol levels at baseline and under stress in adolescent males with attention-deficit hyperactivity disorder, with or without comorbid conduct disorder.

    Science.gov (United States)

    Northover, Clare; Thapar, Anita; Langley, Kate; Fairchild, Graeme; van Goozen, Stephanie H M

    2016-08-30

    Reported findings on cortisol reactivity to stress in young people with ADHD are very variable. This inconsistency may be explained by high rates of comorbidity with Conduct Disorder (CD). The present study examined cortisol responses to a psychosocial stressor in a large sample of adolescent males with ADHD (n=202), with or without a comorbid diagnosis of Conduct Disorder (CD). Associations between stress reactivity and callous-unemotional traits and internalizing symptoms were also assessed. The ADHD only (n=95) and ADHD+CD (n=107) groups did not differ in baseline cortisol, but the ADHD+CD group showed significantly reduced cortisol stress reactivity relative to the ADHD only group. Regression analyses indicated that ADHD symptom severity predicted reduced baseline cortisol, whereas CD symptom severity predicted increased baseline cortisol (ADHD β=-0.24, CD β=0.16, R=0.26) and reduced cortisol stress reactivity (β=-0.17, R=0.17). Callous-unemotional traits and internalizing symptoms were not significantly related to baseline or stress-induced cortisol. Impaired cortisol reactivity is hypothesised to reflect fearlessness and is associated with deficient emotion regulation and inhibition of aggressive and antisocial behaviour. Consequently, it may partly explain the greater severity of problems seen in those with comorbid ADHD and CD. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  9. Joint tests at INL and CEA of a transient hot wire needle probe for in-pile thermal conductivity measurement

    International Nuclear Information System (INIS)

    Daw, J.E.; Knudson, D.L.; Villard, J.F.; Liothin, J.; Destouches, C.; Rempe, J.L.; Matheron, P.; Lambert, T.

    2015-01-01

    Thermal conductivity is a key property that must be known for proper design, testing, and deployment of new fuels and structural materials in nuclear reactors. Thermal conductivity is highly dependent on the physical structure, chemical composition, and the state of the material. Typically, thermal conductivity changes that occur during irradiation are currently measured out-of-pile using a 'cook and look' approach. But repeatedly removing samples from a test reactor to make measurements is expensive, has the potential to disturb phenomena of interest, and only provides understanding of the sample's end state when each measurement is made. There are also limited thermo-physical property data available for advanced fuels; and such data are needed for simulation codes, the development of next generation reactors, and advanced fuels for existing nuclear plants. Being able to quickly characterize fuel thermal conductivity during irradiation can improve the fidelity of data, reduce costs of post-irradiation examinations, increase understanding of how fuels behave under irradiation, and confirm or improve existing thermal conductivity measurement techniques. This paper discusses efforts to develop and evaluate an innovative in-pile thermal conductivity sensor based on the transient hot wire thermal conductivity method (THWM), using a single needle probe (NP) containing a line heat source and thermocouple embedded in the fuel. The sensor that has been designed and manufactured by the Idaho National Laboratory (INL) includes a unique combination of materials, geometry, and fabrication techniques that make the hot wire method suitable for in-pile applications. In particular, efforts were made to minimize the influence of the sensor and maximize fuel hot-wire heating. The probe has a thermocouple-like construction with high temperature resistant materials that remain ductile while resisting transmutation and materials interactions. THWM-NP prototypes were

  10. Joint tests at INL and CEA of a transient hot wire needle probe for in-pile thermal conductivity measurement

    Energy Technology Data Exchange (ETDEWEB)

    Daw, J.E.; Knudson, D.L. [Idaho National Laboratory, Idaho Falls, ID 83415, (United States); Villard, J.F.; Liothin, J.; Destouches, C. [CEA, DEN, DER, Instrumentation Sensors and Dosimetry Laboratory, Cadarache, F-13108 St Paul-Lez-Durance, (France); Rempe, J.L. [Rempe and Associates, LLC, Idaho Falls, ID, 83404 (United States); Matheron, P. [CEA, DEN, DEC, Uranium Fuels Laboratory, Cadarache, F-13108 St Paul-Lez-Durance, (France); Lambert, T. [CEA, DEN, DEC, Innovative Fuel Design and Irradiation Laboratory, Cadarache, F-13108 St Paul-Lez-Durance, (France)

    2015-07-01

    Thermal conductivity is a key property that must be known for proper design, testing, and deployment of new fuels and structural materials in nuclear reactors. Thermal conductivity is highly dependent on the physical structure, chemical composition, and the state of the material. Typically, thermal conductivity changes that occur during irradiation are currently measured out-of-pile using a 'cook and look' approach. But repeatedly removing samples from a test reactor to make measurements is expensive, has the potential to disturb phenomena of interest, and only provides understanding of the sample's end state when each measurement is made. There are also limited thermo-physical property data available for advanced fuels; and such data are needed for simulation codes, the development of next generation reactors, and advanced fuels for existing nuclear plants. Being able to quickly characterize fuel thermal conductivity during irradiation can improve the fidelity of data, reduce costs of post-irradiation examinations, increase understanding of how fuels behave under irradiation, and confirm or improve existing thermal conductivity measurement techniques. This paper discusses efforts to develop and evaluate an innovative in-pile thermal conductivity sensor based on the transient hot wire thermal conductivity method (THWM), using a single needle probe (NP) containing a line heat source and thermocouple embedded in the fuel. The sensor that has been designed and manufactured by the Idaho National Laboratory (INL) includes a unique combination of materials, geometry, and fabrication techniques that make the hot wire method suitable for in-pile applications. In particular, efforts were made to minimize the influence of the sensor and maximize fuel hot-wire heating. The probe has a thermocouple-like construction with high temperature resistant materials that remain ductile while resisting transmutation and materials interactions. THWM-NP prototypes were

  11. Estimation of Stresses in a Dry Sand Layer Tested on Shaking Table

    Science.gov (United States)

    Sawicki, Andrzej; Kulczykowski, Marek; Jankowski, Robert

    2012-12-01

    Theoretical analysis of shaking table experiments, simulating earthquake response of a dry sand layer, is presented. The aim of such experiments is to study seismic-induced compaction of soil and resulting settlements. In order to determine the soil compaction, the cyclic stresses and strains should be calculated first. These stresses are caused by the cyclic horizontal acceleration at the base of soil layer, so it is important to determine the stress field as function of the base acceleration. It is particularly important for a proper interpretation of shaking table tests, where the base acceleration is controlled but the stresses are hard to measure, and they can only be deduced. Preliminary experiments have shown that small accelerations do not lead to essential settlements, whilst large accelerations cause some phenomena typical for limit states, including a visible appearance of slip lines. All these problems should be well understood for rational planning of experiments. The analysis of these problems is presented in this paper. First, some heuristic considerations about the dynamics of experimental system are presented. Then, the analysis of boundary conditions, expressed as resultants of respective stresses is shown. A particular form of boundary conditions has been chosen, which satisfies the macroscopic boundary conditions and the equilibrium equations. Then, some considerations are presented in order to obtain statically admissible stress field, which does not exceed the Coulomb-Mohr yield conditions. Such an approach leads to determination of the limit base accelerations, which do not cause the plastic state in soil. It was shown that larger accelerations lead to increase of the lateral stresses, and the respective method, which may replace complex plasticity analyses, is proposed. It is shown that it is the lateral stress coefficient K0 that controls the statically admissible stress field during the shaking table experiments.

  12. Testing the accelerating moment release (AMR) hypothesis in areas of high stress

    Science.gov (United States)

    Guilhem, Aurélie; Bürgmann, Roland; Freed, Andrew M.; Ali, Syed Tabrez

    2013-11-01

    Several retrospective analyses have proposed that significant increases in moment release occurred prior to many large earthquakes of recent times. However, the finding of accelerating moment release (AMR) strongly depends on the choice of three parameters: (1) magnitude range, (2) area being considered surrounding the events and (3) the time period prior to the large earthquakes. Consequently, the AMR analysis has been criticized as being a posteriori data-fitting exercise with no new predictive power. As AMR has been hypothesized to relate to changes in the state of stress around the eventual epicentre, we compare here AMR results to models of stress accumulation in California. Instead of assuming a complete stress drop on all surrounding fault segments implied by a back-slip stress lobe method, we consider that stress evolves dynamically, punctuated by the occurrence of earthquakes, and governed by the elastic and viscous properties of the lithosphere. We study the seismicity of southern California and extract events for AMR calculations following the systematic approach employed in previous studies. We present several sensitivity tests of the method, as well as grid-search analyses over the region between 1955 and 2005 using fixed magnitude range, radius of the search area and period of time. The results are compared to the occurrence of large events and to maps of Coulomb stress changes. The Coulomb stress maps are compiled using the coseismic stress from all M > 7.0 earthquakes since 1812, their subsequent post-seismic relaxation, and the interseismic strain accumulation. We find no convincing correlation of seismicity rate changes in recent decades with areas of high stress that would support the AMR hypothesis. Furthermore, this indicates limited utility for practical earthquake hazard analysis in southern California, and possibly other regions.

  13. Test with different stress measurement methods in two orthogonal bore holes in Aespoe HRL

    Energy Technology Data Exchange (ETDEWEB)

    Janson, Thomas; Stigsson, Martin [Golder Associates AB, Stockholm (Sweden)

    2002-12-01

    Within the scope of work, to provide the necessary rock mechanics support for the site investigations, SKB has studied some available pieces of equipment for in situ stress measurements in deep boreholes. A project with the objective to compare three different pieces of equipment for in situ stress measurements under similar conditions has been carried out. The main objective for the project is to compare the three different pieces of equipment for in situ stress measurements and find a strategy for SKB's Site Investigations to determine the state of stress in the rock mass. Two units of equipment use the overcoring method while the third uses the hydraulic fracturing method. The overcoring was performed by AECL, using Deep Door stopper Gauge System (DDGS), and SwedPower, using their triaxial strain measuring instrument (Borre Probe). MeSy Geo Systeme GmbH performed the hydraulic fracturing. The DDGS system is a new method to SKB while the experience of the SwedPower overcoring and the hydraulic fracturing methods are long. The tests were performed in the same orthogonal boreholes at Aespoe Hard Rock Laboratory (HRL), Oskarshamn, Sweden. The measured results have been verified against known conditions at the Aespoe HRL. The results from the three in situ stress measurement methods rose more questions than answers. Which illustrate the complexity to determine the in situ stresses in a rock mass. To understand the difference in results and answer the questions, it was necessary to do deeper investigations such as laboratory tests and theoretical calculations such as geological structure model, analysis of the influence of a nearby fracture, P-wave measurements, uniaxial tests on small cores from the HQ-3 core, theoretical and numerical analyses of the hole bottom (theoretical strains, stress concentrations and microcracking), auditing of DDGS measurements results and assumptions in the DDGS analyse and microscopy investigations on the cores. The following

  14. Effect of Salinity Stress and Foliar Application of Methyl Jasmonate on Photosynthetic Rate, Stomatal Conductance, Water Use Efficiency and Yield of German Chamomile

    Directory of Open Access Journals (Sweden)

    fatemeh Salimi

    2014-09-01

    Full Text Available Jasmonate is new plant growth regulator that plays an essential role at increasing plants resistance to the environmental stresses like salinity stress. Hence, in this research the effect of foliar application of methyl jasmonate on some physiological indices and yield of German chamomile under salinity conditions was studied. A factorial experiment was laid out based on randomized complete block design (RCBD with three replications in the greenhouse condition. Foliar application of methyl jasmonate was five levels (MJ1; 0, MJ2; 75, MJ3; 150, MJ4; 225 and MJ5; 300 μM and salinity stress was four levels (S1; 2, S2; 6, S3; 10, S4; 14 dS m-1. The effect of methyl jasmonate, salinity condition treatments and their interaction was significant for traits of photosynthesis rate, stomata conductance, transpiration rate, carboxylation efficiency, intercellular CO2 concentration and yield of flower. The highest values of photosynthetic rate, stomata conductance, transpiration rate, carboxylation efficiency and yield of flower (3.76 g pot-1 and the lowest intercellular CO2 concentration were achieved at MJ×S treatment. Maximum value of photosynthetic water use efficiency was revealed at MJ5×S2 treatment. With decreasing stomata conductance, photosynthetic water use efficiency and intercellular CO2 concentration were increased. In general, it seems that application of methyl jasmonate by lower dose (MJ2 under salinity conditions especially mild salinity stress (S2 can improve physiological indices and yield of chamomile.

  15. Objective effect manifestation of pectus excavatum on load-stressed pulmonary function testing: a case report

    Directory of Open Access Journals (Sweden)

    Chan Jason

    2011-12-01

    Full Text Available Abstract Introduction Pectus excavatum is the most common congenital deformity of the anterior chest wall that, under certain conditions, may pose functional problems due to cardiopulmonary compromise and exercise intolerance. Case presentation We present the case of an otherwise physically-adept 21-year-old Chinese sportsman with idiopathic pectus excavatum, whose symptoms manifested only on bearing a loaded body vest and backpack during physical exercise. Corroborative objective evidence was obtained via load-stressed pulmonary function testing, which demonstrated restrictive lung function. Conclusion This report highlights the possible detrimental synergism of thoracic load stress and pectus excavatum on cardiopulmonary function. Thoracic load-stressed pulmonary function testing provides objective evidence in support of such a synergistic relationship.

  16. Developing the multiple stress-strain creep recovery (MS-SCR) test

    Science.gov (United States)

    Elnasri, Mahmoud; Airey, Gordon; Thom, Nick

    2018-04-01

    While most published work from Europe has been concerned with evaluating binders' resistance to rutting based on their stiffness (deformation resistance), work originating in the US has mainly been concerned with ranking binders based on their recoverability in a multiple stress form. This paper details the design of a new modified multiple stress-strain creep recovery (MS-SCR) test. The test is designed to evaluate binders' rutting resistance based on two rutting resistance mechanisms: stiffness and recoverability. A preliminary investigation is presented in this paper followed by details of the design of the new modified test. A 40/60 penetration grade bitumen and bitumen-filler mastics prepared with three filler concentrations (35%, 50%, and 65% filler content by mass of mastic) were tested. In addition, two polymer modified bitumens (PMBs) using the same base bitumen type were examined for validation. Two parameters are introduced to characterise the short and long recovery in the new test. In terms of stiffness, the test allows the behaviour of binders at different stress levels and loading cycles to be studied and produces a new parameter that can quantify the degree of modification. Finally, a relationship between nonlinearity and normal force in the test was investigated.

  17. Axi-symmetric generalized thermoelastic diffusion problem with two-temperature and initial stress under fractional order heat conduction

    International Nuclear Information System (INIS)

    Deswal, Sunita; Kalkal, Kapil Kumar; Sheoran, Sandeep Singh

    2016-01-01

    A mathematical model of fractional order two-temperature generalized thermoelasticity with diffusion and initial stress is proposed to analyze the transient wave phenomenon in an infinite thermoelastic half-space. The governing equations are derived in cylindrical coordinates for a two dimensional axi-symmetric problem. The analytical solution is procured by employing the Laplace and Hankel transforms for time and space variables respectively. The solutions are investigated in detail for a time dependent heat source. By using numerical inversion method of integral transforms, we obtain the solutions for displacement, stress, temperature and diffusion fields in physical domain. Computations are carried out for copper material and displayed graphically. The effect of fractional order parameter, two-temperature parameter, diffusion, initial stress and time on the different thermoelastic and diffusion fields is analyzed on the basis of analytical and numerical results. Some special cases have also been deduced from the present investigation.

  18. Testing nonlocal models of electron thermal conduction for magnetic and inertial confinement fusion applications

    Science.gov (United States)

    Brodrick, J. P.; Kingham, R. J.; Marinak, M. M.; Patel, M. V.; Chankin, A. V.; Omotani, J. T.; Umansky, M. V.; Del Sorbo, D.; Dudson, B.; Parker, J. T.; Kerbel, G. D.; Sherlock, M.; Ridgers, C. P.

    2017-09-01

    Three models for nonlocal electron thermal transport are here compared against Vlasov-Fokker-Planck (VFP) codes to assess their accuracy in situations relevant to both inertial fusion hohlraums and tokamak scrape-off layers. The models tested are (i) a moment-based approach using an eigenvector integral closure (EIC) originally developed by Ji, Held, and Sovinec [Phys. Plasmas 16, 022312 (2009)]; (ii) the non-Fourier Landau-fluid (NFLF) model of Dimits, Joseph, and Umansky [Phys. Plasmas 21, 055907 (2014)]; and (iii) Schurtz, Nicolaï, and Busquet's [Phys. Plasmas 7, 4238 (2000)] multigroup diffusion model (SNB). We find that while the EIC and NFLF models accurately predict the damping rate of a small-amplitude temperature perturbation (within 10% at moderate collisionalities), they overestimate the peak heat flow by as much as 35% and do not predict preheat in the more relevant case where there is a large temperature difference. The SNB model, however, agrees better with VFP results for the latter problem if care is taken with the definition of the mean free path. Additionally, we present for the first time a comparison of the SNB model against a VFP code for a hohlraum-relevant problem with inhomogeneous ionisation and show that the model overestimates the heat flow in the helium gas-fill by a factor of ˜2 despite predicting the peak heat flux to within 16%.

  19. High conduction neutron absorber to simulate fast reactor environment in an existing test reactor

    Energy Technology Data Exchange (ETDEWEB)

    Donna Post Guillen; Larry R. Greenwood; James R. Parry

    2014-06-22

    A new metal matrix composite material has been developed to serve as a thermal neutron absorber for testing fast reactor fuels and materials in an existing pressurized water reactor. The performance of this material was evaluated by placing neutron fluence monitors within shrouded and unshrouded holders and irradiating for up to four cycles. The monitor wires were analyzed by gamma and X-ray spectrometry to determine the activities of the activation products. Adjusted neutron fluences were calculated and grouped into three bins—thermal, epithermal, and fast—to evaluate the spectral shift created by the new material. A comparison of shrouded and unshrouded fluence monitors shows a thermal fluence decrease of ~11 % for the shielded monitors. Radioisotope activity and mass for each of the major activation products is given to provide insight into the evolution of thermal absorption cross-section during irradiation. The thermal neutron absorption capability of the composite material appears to diminish at total neutron fluence levels of ~8 × 1025 n/m2. Calculated values for dpa in excess of 2.0 were obtained for two common structural materials (iron and nickel) of interest for future fast flux experiments.

  20. Analysis of pin removal experiments conducted in an SCWR-like test lattice

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, R. [Paul Scherrer Institue, CH-5232 Villigen PSI (Switzerland); Swiss Federal Inst. of Technology EPFL, CH-1015 Lausanne (Switzerland); Raetz, D. [Paul Scherrer Institue, CH-5232 Villigen PSI (Switzerland); Resun AG, CH-5001 Aarau (Switzerland); Jordan, K. A. [Paul Scherrer Institue, CH-5232 Villigen PSI (Switzerland); Univ. of Florida, Gainesville, FL (United States); Perret, G. [Paul Scherrer Institue, CH-5232 Villigen PSI (Switzerland)

    2012-07-01

    A comprehensive program of integral experiments, largely based on the measurement of reaction rate distributions, was carried out recently on an SCWR-like fuel lattice in the central test zone of the PROTEUS zero-power research reactor at the Paul Scherrer Inst. in Switzerland. The present paper reports on the analysis of a complementary set of measurements, in which the reactivity effects of removing individual pins from the unperturbed, heterogeneously moderated reference lattice were investigated. It has been found that the detailed Monte Carlo modeling of the whole reactor using MCNPX is able - as in the case of the reaction rate distributions - to reproduce the experimental results for the pin removal worths within the achievable statistical accuracy. A comparison of reduced-geometry calculations between MCNPX and the deterministic LWR assembly code CASMO-4E has revealed certain discrepancies. On the basis of a reactivity decomposition analysis of the differences between the codes, it has been suggested that these could be due to CASMO-4E deficiencies in calculating the effect, upon pin removal, of the extra moderation in the neighboring fuel pins. (authors)

  1. Methodological approaches to conducting pilot and proof tests on reverse-osmosis systems: Results of comparative studies

    Science.gov (United States)

    Panteleev, A. A.; Bobinkin, V. V.; Larionov, S. Yu.; Ryabchikov, B. E.; Smirnov, V. B.; Shapovalov, D. A.

    2017-10-01

    When designing large-scale water-treatment plants based on reverse-osmosis systems, it is proposed to conduct experimental-industrial or pilot tests for validated simulation of the operation of the equipment. It is shown that such tests allow establishing efficient operating conditions and characteristics of the plant under design. It is proposed to conduct pilot tests of the reverse-osmosis systems on pilot membrane plants (PMPs) and test membrane plants (TMPs). The results of a comparative experimental study of pilot and test membrane plants are exemplified by simulating the operating parameters of the membrane elements of an industrial plant. It is concluded that the reliability of the data obtained on the TMP may not be sufficient to design industrial water-treatment plants, while the PMPs are capable of providing reliable data that can be used for full-scale simulation of the operation of industrial reverse-osmosis systems. The test membrane plants allow simulation of the operating conditions of individual industrial plant systems; therefore, potential areas of their application are shown. A method for numerical calculation and experimental determination of the true selectivity and the salt passage are proposed. An expression has been derived that describes the functional dependence between the observed and true salt passage. The results of the experiments conducted on a test membrane plant to determine the true value of the salt passage of a reverse-osmosis membrane are exemplified by magnesium sulfate solution at different initial operating parameters. It is shown that the initial content of a particular solution component has a significant effect on the change in the true salt passage of the membrane.

  2. Maternal Health Status and Parenting Stress in Low-Income, Ethnic-Minority Mothers of Children with Conduct Disorder Problems: the Role of Daily Parenting Hassles.

    Science.gov (United States)

    BeLue, Rhonda; Halgunseth, Linda C; Abiero, Beatrice; Bediako, Phylicia

    2015-12-01

    Minimal attention has been given to understanding parenting stress among low-income, ethnically diverse mothers of children with conduct problems. Maternal health and parenting hassles may serve as important risk factors for parenting stress. This study examined whether parenting hassles mediated the relations between maternal physical and mental health and parenting stress in a sample of low-income, ethnically diverse mothers of children with behavioral problems. The sample included 177 low-income black, Latina, and white mothers of kindergartners with behavior problems. Path analysis was employed to assess the associations between maternal mental and physical health and parenting stress, as well as the moderating role of parenting hassles in this cross-sectional study. After adjusting for covariates, we found that parenting hassles mediated the relationship between social support and parenting stress as well as maternal health and parenting stress. Findings suggest that promoting coping resources for daily parenting hassles and supporting the physical and mental health of minority mothers may have important implications for parenting children with high behavior problems.

  3. Developing Field Test Procedures for Chloride Stress Corrosion Cracking in the Arabian Gulf

    Directory of Open Access Journals (Sweden)

    Hanan Farhat

    2018-01-01

    Full Text Available Oil and gas production and petrochemical plants in the Arabian Gulf are exposed to severe environmental conditions of high temperature and humidity. This makes these plants susceptible to chloride-induced stress corrosion cracking (CSCC. The laboratory testing fails to provide the exact field environmental conditions. A cost efficient field test setup for CSCC was designed and developed for the Arabian Gulf. The setup included designing self-sustained loading devices, samples, and sample racks. The samples were exposed to a stress equivalent to 80% and 100% of their yield strength. This paper describes the developed test procedures to establish testing with high level of accuracy and repeatability. It also discusses the design aspects and the challenges that were met.

  4. Stress

    Science.gov (United States)

    ... taking care of an aging parent. With mental stress, the body pumps out hormones to no avail. Neither fighting ... with type 1 diabetes. This difference makes sense. Stress blocks the body from releasing insulin in people with type 2 ...

  5. Lessons learned from EU stress tests evaluations with regard to external hazards

    International Nuclear Information System (INIS)

    Misak, J.

    2014-01-01

    The presentation was oriented to critical review of the lessons learned from the European Union (EU) Stress Test focusing on NPP robustness against external hazards. These lessons addressed: - organization of the stress tests, - scope and objectives of the stress tests, - peer review findings, recommendations and implications on the design in the area of external hazards, - further studies recommended in the area of external hazards and PSA, - relevant research areas identified by the SNETP Task Group in response to Fukushima accident. Some important conclusions were made in the final part of the presentation: - Vulnerability to the Fukushima Dai-ichi reactor accidents caused by external hazards and including their secondary effects was underestimated, - Lessons learned from Fukushima Dai-ichi reactor accidents, from the EU Stress Test and from peer reviews are to be reflected in safety improvements of operating plants and considered in new designs, - while no completely new phenomena were revealed from the Fukushima Dai-ichi reactor accidents, improvements in specific research areas (including external hazards and use of PSA) should be considered with high priority

  6. Economic Crisis and Marital Problems in Turkey: Testing the Family Stress Model

    Science.gov (United States)

    Aytac, Isik A.; Rankin, Bruce H.

    2009-01-01

    This paper applied the family stress model to the case of Turkey in the wake of the 2001 economic crisis. Using structural equation modeling and a nationally representative urban sample of 711 married women and 490 married men, we tested whether economic hardship and the associated family economic strain on families resulted in greater marital…

  7. 12 CFR Appendix A to Subpart B of... - Risk-Based Capital Stress Test

    Science.gov (United States)

    2010-01-01

    ... required by statute under stipulated conditions of credit risk and interest rate risk. The stress test uses... credit risk, interest rate risk, the cashflow generator, and the capital calculation. Linkages among the components ensure that the measures of credit and interest rate risk pass into the cashflow generator. The...

  8. Emotional-volitional components of operator reliability. [sensorimotor function testing under stress

    Science.gov (United States)

    Mileryan, Y. A.

    1975-01-01

    Sensorimotor function testing in a tracking task under stressfull working conditions established a psychological characterization for a successful aviation pilot: Motivation significantly increased the reliability and effectiveness of their work. Their acitivities were aimed at suppressing weariness and the feeling of fear caused by the stress factors; they showed patience, endurance, persistence, and a capacity for lengthy volitional efforts.

  9. Relationship between Academic Stress and Suicidal Ideation: Testing for Depression as a Mediator Using Multiple Regression

    Science.gov (United States)

    Ang, Rebecca P.; Huan, Vivien S.

    2006-01-01

    Relations among academic stress, depression, and suicidal ideation were examined in 1,108 Asian adolescents 12-18 years old from a secondary school in Singapore. Using Baron and Kenny's [J Pers Soc Psychol 51:1173-1192, 1986] framework, this study tested the prediction that adolescent depression mediated the relationship between academic stress…

  10. 78 FR 71435 - Policy Statement on the Scenario Design Framework for Stress Testing

    Science.gov (United States)

    2013-11-29

    ... as a means to better understand the range of a financial company's potential risk exposures.\\2\\ \\1\\ A... to include in the macroeconomic scenarios and in the market shock component of the stress test... described the Board's approach to developing the macroeconomic scenarios and market shocks, as well as the...

  11. Belgium; Technical Note on Stress Testing the Banking and Insurance Sectors

    OpenAIRE

    International Monetary Fund

    2013-01-01

    The Belgium Financial Sector Assessment Program (FSAP) stress testing exercise examines a financial sector that remains in a state of transformation. Domestic economic challenges remain sources of continued uncertainty as the banking sector consolidates and reduces funding risks. Insurers face challenges from adverse economic and business conditions. Solvency and funding shocks under different macroeconomic scenarios were assessed. Both banking and insurance tests underscore the importance of...

  12. Standard Test Method for Testing Polymeric Seal Materials for Geothermal and/or High Temperature Service Under Sealing Stress

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1985-01-01

    1.1 This test method covers the initial evaluation of (screening) polymeric materials for seals under static sealing stress and at elevated temperatures. 1.2 This test method applies to geothermal service only if used in conjunction with Test Method E 1068. 1.3 The test fluid is distilled water. 1.4 The values stated in SI units are to be regarded as the standard. The values in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  13. Stress-deformed state of cylindrical specimens during indirect tensile strength testing

    Directory of Open Access Journals (Sweden)

    Levan Japaridze

    2015-10-01

    Full Text Available In this study, the interaction between cylindrical specimen made of homogeneous, isotropic, and linearly elastic material and loading jaws of any curvature is considered in the Brazilian test. It is assumed that the specimen is diametrically compressed by elliptic normal contact stresses. The frictional contact stresses between the specimen and platens are neglected. The analytical solution starts from the contact problem of the loading jaws of any curvature and cylindrical specimen. The contact width, corresponding loading angle (2θ0, and elliptical stresses obtained through solution of the contact problems are used as boundary conditions for a cylindrical specimen. The problem of the theory of elasticity for a cylinder is solved using Muskhelishvili's method. In this method, the displacements and stresses are represented in terms of two analytical functions of a complex variable. In the main approaches, the nonlinear interaction between the loading bearing blocks and the specimen as well as the curvature of their surfaces and the elastic parameters of their materials are taken into account. Numerical examples are solved using MATLAB to demonstrate the influence of deformability, curvature of the specimen and platens on the distribution of the normal contact stresses as well as on the tensile and compressive stresses acting across the loaded diameter. Derived equations also allow calculating the modulus of elasticity, total deformation modulus and creep parameters of the specimen material based on the experimental data of radial contraction of the specimen.

  14. Myocordial perfusion SPECT with dipyridamole stress test in cardiac syndrome X

    International Nuclear Information System (INIS)

    Czepczynski, R.; Smolarek, I.; Sowinski, J.; Rogacka, D.; Kazmierczak, M.; Wysocki, H.

    2006-01-01

    Cardiac syndrome X defines patients with typical anginal chest pain, a positive exercise ECG stress test and angiographically normal coronary arteries. Aim of this study was to evaluate the role of myocardial perfusion SPECT with dipyridamole stress in the diagnosis of cardiac syndrome X. Patients, methods: 68 patients with syndrome X aged 32 to 60 years were subjected to myocardial imaging using 99m Tc-MIBI according to the two-days protocol: at rest and after dipyridamole infusion. Semiquantitative evaluation of the images was based on the assessment of 99m Tc-MIBI uptake in 17 myocardial segments using a 5-points scale (0 point - normal uptake, 4 points - no uptake). Scores obtained in each segment were summed up, constituting the summed rest score (SRS) and summed stress score (SSS). Results: mean SRS was 7.9 ± 4.8 and mean SSS was 7.2 ± 4.4 (non-significant difference). Individual comparison of SRS and SSS values revealed three patterns of scintigraphic images: (1) in 25 patients (36.8%), a paradoxical improvement of perfusion at stress images was found, (2) in 23 patients (33.8%), the myocardial perfusion deteriorated after dipyridamole, (3) in 20 patients (29.4%), no significant change of the myocordial perfusion between rest and stress images occurred. Conclusions: in cardiac syndrome X, myocardial SPECT with dipyridamole stress shows different patterns of myocardial perfusion that reflects heterogeneity of this pathology. (orig.)

  15. Pre-test analysis results of a PWR steel lined pre-stressed concrete containment model

    International Nuclear Information System (INIS)

    Basha, S.M.; Ghosh, Barnali; Patnaik, R.; Ramanujam, S.; Singh, R.K.; Kushwaha, H.S.; Venkat Raj, V.

    2000-02-01

    Pre-stressed concrete nuclear containment serves as the ultimate barrier against the release of radioactivity to the environment. This ultimate barrier must be checked for its ultimate load carrying capacity. BARC participated in a Round Robin analysis activity which is co-sponsored by Sandia National Laboratory, USA and Nuclear Power Engineering Corporation Japan for the pre-test prediction of a 1:4 size Pre-stressed Concrete Containment Vessel. In house finite element code ULCA was used to make the test predictions of displacements and strains at the standard output locations. The present report focuses on the important landmarks of the pre-test results, in sequential terms of first crack appearance, loss of pre-stress, first through thickness crack, rebar and liner yielding and finally liner tearing at the ultimate load. Global and local failure modes of the containment have been obtained from the analysis. Finally sensitivity of the numerical results with respect to different types of liners and different constitutive models in terms of bond strength between concrete and steel and tension-stiffening parameters are examined. The report highlights the important features which could be observed during the test and guidelines are given for improving the prediction in the post test computation after the test data is available. (author)

  16. Longitudinal and Integrative Tests of Family Stress Model Effects on Mexican-Origin Adolescents

    Science.gov (United States)

    White, Rebecca M. B.; Liu, Yu; Nair, Rajni L.; Tein, Jenn-Yun

    2015-01-01

    The family stress model represents a common framework through which to examine the effects of environmental stressors on adolescent adjustment. The model suggests that economic and neighborhood stressors influence youth adjustment via disruptions to parenting. Incorporating integrative developmental theory, we examined the degree to which parents’ cultural value orientations mitigated the effects of stressors on parenting disruptions and the degree to which environmental adversity qualified the effect of parenting on adolescent adjustment. We tested the hypothesized Integrative Family Stress Model longitudinally in a sample of mother-youth dyads (N = 749) and father-youth dyads (N = 467) from Mexican origin families, across three times points spanning early to middle adolescence. Providing the first longitudinal evidence of family stress mediated effects, mothers’ perceptions of economic pressure were associated with increases in adolescent externalizing symptoms five years later via intermediate increases in harsh parenting. The remaining findings supported the notion that integrative developmental theory can inform family stress model hypothesis testing that is culturally and contextually relevant for wide range of diverse families and youth. For example, fathers’ perceptions of economic pressure and neighborhood danger had important implications for adolescent internalizing, via reductions in paternal warmth, but only at certain levels of neighborhood adversity. Mothers’ familism value orientations mitigated the effects of economic pressure on maternal warmth, protecting their adolescents from experiencing developmental costs associated with environmental stressors. Results are discussed in terms of identifying how integrative developmental theory intersects with the family stress model to set diverse youth on different developmental pathways. PMID:25751100

  17. Estimation of In Situ Stresses with Hydro-Fracturing Tests and a Statistical Method

    Science.gov (United States)

    Lee, Hikweon; Ong, See Hong

    2018-03-01

    At great depths, where borehole-based field stress measurements such as hydraulic fracturing are challenging due to difficult downhole conditions or prohibitive costs, in situ stresses can be indirectly estimated using wellbore failures such as borehole breakouts and/or drilling-induced tensile failures detected by an image log. As part of such efforts, a statistical method has been developed in which borehole breakouts detected on an image log are used for this purpose (Song et al. in Proceedings on the 7th international symposium on in situ rock stress, 2016; Song and Chang in J Geophys Res Solid Earth 122:4033-4052, 2017). The method employs a grid-searching algorithm in which the least and maximum horizontal principal stresses ( S h and S H) are varied, and the corresponding simulated depth-related breakout width distribution as a function of the breakout angle ( θ B = 90° - half of breakout width) is compared to that observed along the borehole to determine a set of S h and S H having the lowest misfit between them. An important advantage of the method is that S h and S H can be estimated simultaneously in vertical wells. To validate the statistical approach, the method is applied to a vertical hole where a set of field hydraulic fracturing tests have been carried out. The stress estimations using the proposed method were found to be in good agreement with the results interpreted from the hydraulic fracturing test measurements.

  18. Interpretation of Flow Logs from Nevada Test Site Boreholes to Estimate Hydraulic conductivity Using Numerical Simulations Constrained by Single-Well Aquifer Tests

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, C. Amanda; Halford, Keith J.; Laczniak, Randell J.

    2010-02-12

    Hydraulic conductivities of volcanic and carbonate lithologic units at the Nevada Test Site were estimated from flow logs and aquifer-test data. Borehole flow and drawdown were integrated and interpreted using a radial, axisymmetric flow model, AnalyzeHOLE. This integrated approach is used because complex well completions and heterogeneous aquifers and confining units produce vertical flow in the annular space and aquifers adjacent to the wellbore. AnalyzeHOLE simulates vertical flow, in addition to horizontal flow, which accounts for converging flow toward screen ends and diverging flow toward transmissive intervals. Simulated aquifers and confining units uniformly are subdivided by depth into intervals in which the hydraulic conductivity is estimated with the Parameter ESTimation (PEST) software. Between 50 and 150 hydraulic-conductivity parameters were estimated by minimizing weighted differences between simulated and measured flow and drawdown. Transmissivity estimates from single-well or multiple-well aquifer tests were used to constrain estimates of hydraulic conductivity. The distribution of hydraulic conductivity within each lithology had a minimum variance because estimates were constrained with Tikhonov regularization. AnalyzeHOLE simulated hydraulic-conductivity estimates for lithologic units across screened and cased intervals are as much as 100 times less than those estimated using proportional flow-log analyses applied across screened intervals only. Smaller estimates of hydraulic conductivity for individual lithologic units are simulated because sections of the unit behind cased intervals of the wellbore are not assumed to be impermeable, and therefore, can contribute flow to the wellbore. Simulated hydraulic-conductivity estimates vary by more than three orders of magnitude across a lithologic unit, indicating a high degree of heterogeneity in volcanic and carbonate-rock units. The higher water transmitting potential of carbonate-rock units relative

  19. Interpretation of Flow Logs from Nevada Test Site Boreholes to Estimate Hydraulic Conductivity Using Numerical Simulations Constrained by Single-Well Aquifer Tests

    Science.gov (United States)

    Garcia, C. Amanda; Halford, Keith J.; Laczniak, Randell J.

    2010-01-01

    Hydraulic conductivities of volcanic and carbonate lithologic units at the Nevada Test Site were estimated from flow logs and aquifer-test data. Borehole flow and drawdown were integrated and interpreted using a radial, axisymmetric flow model, AnalyzeHOLE. This integrated approach is used because complex well completions and heterogeneous aquifers and confining units produce vertical flow in the annular space and aquifers adjacent to the wellbore. AnalyzeHOLE simulates vertical flow, in addition to horizontal flow, which accounts for converging flow toward screen ends and diverging flow toward transmissive intervals. Simulated aquifers and confining units uniformly are subdivided by depth into intervals in which the hydraulic conductivity is estimated with the Parameter ESTimation (PEST) software. Between 50 and 150 hydraulic-conductivity parameters were estimated by minimizing weighted differences between simulated and measured flow and drawdown. Transmissivity estimates from single-well or multiple-well aquifer tests were used to constrain estimates of hydraulic conductivity. The distribution of hydraulic conductivity within each lithology had a minimum variance because estimates were constrained with Tikhonov regularization. AnalyzeHOLE simulated hydraulic-conductivity estimates for lithologic units across screened and cased intervals are as much as 100 times less than those estimated using proportional flow-log analyses applied across screened intervals only. Smaller estimates of hydraulic conductivity for individual lithologic units are simulated because sections of the unit behind cased intervals of the wellbore are not assumed to be impermeable, and therefore, can contribute flow to the wellbore. Simulated hydraulic-conductivity estimates vary by more than three orders of magnitude across a lithologic unit, indicating a high degree of heterogeneity in volcanic and carbonate-rock units. The higher water transmitting potential of carbonate-rock units relative

  20. 40 CFR Table E-2 to Subpart E of... - Spectral Energy Distribution and Permitted Tolerance for Conducting Radiative Tests

    Science.gov (United States)

    2010-07-01

    ... Permitted Tolerance for Conducting Radiative Tests E Table E-2 to Subpart E of Part 53 Protection of... Reference Methods and Class I and Class II Equivalent Methods for PM2.5 or PM10â2.5 Pt. 53, Subpt. E, Table E-2 Table E-2 to Subpart E of Part 53—Spectral Energy Distribution and Permitted Tolerance for...

  1. Effects of electric field and Coriolis force on electrohydrodynamic stability of poorly conducting couple stress parallel fluid flow in a channel

    International Nuclear Information System (INIS)

    Shankar, B.M.; Rudraiah, N.

    2013-01-01

    The effective functioning of microfluidic devices in chemical, electrical and mechanical engineering involving fluidics particularly those having vibrations and petroleum products containing organic, inorganic and other microfluidics require understanding and control of stability of poorly conducting parallel fluid flows. The electrical conductivity, σ, of a poorly conducting fluidics, increases with the temperature and the concentration of freely suspended particles like RBC, WBC and so on in the blood, the hylauronic acid (HA) and nutrients of synovial fluid in synovial joints will spin producing microrotation, forming micropolar fluid of Eringen. The presence of Deuterium - Tritium (DT) in inertial fusion target (IFT) may also be modeled using micropolar fluid theory of Eringen. A particular case of micropolar fluid theory when microrotation balances with the natural vorticity of a poorly conducting fluidics in the presence of an electric field is called ‘electrohydrodynamic couple stress fluid’ (EHDCF). These EHDCFs exhibit a variation of electrical conductivity, ∇ σ, increasing with temperature and concentration of freely suspended particles, releases the charges from the nuclei forming distribution of charge density, ρ e . These charges induce an electric field, 1 E i . If need be, we can apply an electric field, 1 E a , by embedding electrodes of different potentials at the boundaries. The total electric field, 1 E = 1 E i + 1 E a , produces a current density, 1 J = ρ σ 1 E, according to Ohm’s law and also produces an electric force, 1 F σ = σ 1 E. This current 1 J acts as sensing and the force, 1 F σ acts as actuation. These two properties make the poorly conducting couple stress fluid to act as a smart material. The objective of this paper is to show that EHDCV in presence of coriolis force plays a significant role in controlling the stability of parallel flows which is essential for an effective functioning of machineries that occur in

  2. Preparation, Conduct and Evaluation of Exercises to Test Preparedness for a Nuclear or Radiological Emergency - Training Materials

    International Nuclear Information System (INIS)

    2010-01-01

    Emergency response exercises are a key component of a good program of preparation in emergencies. They can provide a unique insight on the State of preparation of emergency response organizations. They can also be the basis for continuous improvement programs of the infrastructure of response in emergencies. However, to be more useful, the exercises in emergency response need to be well organized, professionally conducted and its assessment should focus on the potential for constructive improvement. The course of the IAEA on preparedness, conduction and evaluation exercises to test the preparation before a nuclear emergency or radiation designed for people and organizations that want to increase their ability to carry out effective and significant emergency exercises. The objectives of this course are: To familiarize participants with concepts, terminology, process of preparation, conduction and evaluation of the exercise to test the preparation before a nuclear emergency or radiation; Provide participants with knowledge practical and the ability to organize, lead and evaluate an exercise to test the preparation for a nuclear emergency or radiation in their own countries; Submit an exercise response model in emergency prepared by the IAEA; and give participants the skill to adapt the proposal of model exercise and organize and lead this exercise model right in your own country. [es

  3. Public health genomics and genetic test evaluation: the challenge of conducting behavioural research on the utility of lifestyle-genetic tests.

    Science.gov (United States)

    Sanderson, Saskia C; Wardle, Jane; Humphries, Steve E

    2008-01-01

    Human genetics research is increasingly concerned with multifactorial conditions such as diabetes and heart disease, which are influenced not only by genetic but also lifestyle factors such as diet and smoking. Although the results of 'lifestyle-genetic' tests using this information could conceivably motivate lifestyle changes in the future, companies are already selling such tests and related lifestyle advice commercially. Some academics and lobby groups have condemned the companies for selling these tests in advance of scientific support. Others are concerned that the tests may not motivate lifestyle improvements, instead causing distress in people receiving adverse test results and complacency in those receiving reassuring results. There is currently no regulatory oversight of genetic test utility, despite consensus in the Public Health Genomics community that clinical utility (including psychological and behavioural impact) of all emerging genetic tests should be evaluated before being introduced for individual use. Clearly, empirical data in this area is much needed, to inform understanding of the potential utility of these tests, and of whether stricter regulation of commercial exploitation is needed. In this article, we review the current situation regarding lifestyle-genetic tests, and discuss the challenges inherent in conducting this kind of behavioural research in the genomics era. Copyright 2008 S. Karger AG, Basel.

  4. The evaluation of Young's modulus and residual stress of Cu films by NiFe/Cu bilayer film microbridge tests

    International Nuclear Information System (INIS)

    Zhou Zhimin; Zhou Yong; Cao Ying; Ding Wen; Mao Haiping

    2008-01-01

    This paper proposes a method to estimate the thickness limit for single-layer microbridge tests and also the thickness limit of one film on another film with known thickness for bilayer microbridge tests. To evaluate the mechanical properties of the Cu film, which could not be measured by single-layer microbridge tests, the NiFe single-layer film and NiFe/Cu bilayer film on silicon substrate are fabricated onto the microbridge by the MEMS technique. A load–deflection experiment is conducted upon the ceramic shaft adhered to the microbridge center by means of the XP nanoindenter system. From single-layer microbridge theory, Young's modulus and the residual stress of the NiFe film are deduced to be 192.74 ± 8.10 GPa and 287.75 ± 16.18 MPa, respectively. The data are introduced into bilayer microbridge theory and Young's modulus and the residual stress of the copper film are calculated to be 118.71 ± 6.54 GPa and 41.34 ± 4.42 MPa, respectively. The experimental results correspond well with those of nanoindentation

  5. Standard practice for preparation and use of direct tension stress-corrosion test specimens

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1985-01-01

    1.1 This practice covers procedures for designing, preparing, and using ASTM standard tension test specimens for investigating susceptibility to stress-corrosion cracking. Axially loaded specimens may be stressed quantitatively with equipment for application of either a constant load, constant strain, or with a continuously increasing strain. 1.2 Tension test specimens are adaptable for testing a wide variety of product forms as well as parts joined by welding, riveting, or various other methods. 1.3 The exposure of specimens in a corrosive environment is treated only briefly because other standards are being prepared to deal with this aspect. Meanwhile, the investigator is referred to Practices G35, G36, G37, and G44, and to ASTM Special Technical Publication 425 (1).

  6. VAR, stress-testing and supplementary methodologies: uses and constraints in energy risk management

    International Nuclear Information System (INIS)

    Senior, Brian

    1999-01-01

    This chapter lists some of the special risks associated with a range of energy markets, and questions what is risk. Market risk, the use of value-at-risk (VAR) for measuring and managing market risk, use of VAR in the banking sector, back-testing of VAR, the corporate sector, making investment decisions, and the need for additional methods of risk analysis are discussed. Scenario analysis and stress testing, liquidity, and combining VAR and stress-testing are described. Credit risk and the quantitative analysis of credit risk are addressed, and operational risk, and organisational challenges are considered. Panels present examples of a simple VAR calculation and give descriptions of VAR in corporate decisions, the measurement of liquidity, and the use of the Greeks in decisions on day to day trading and risk management

  7. An open-source framework for stress-testing non-invasive foetal ECG extraction algorithms.

    Science.gov (United States)

    Andreotti, Fernando; Behar, Joachim; Zaunseder, Sebastian; Oster, Julien; Clifford, Gari D

    2016-05-01

    Over the past decades, many studies have been published on the extraction of non-invasive foetal electrocardiogram (NI-FECG) from abdominal recordings. Most of these contributions claim to obtain excellent results in detecting foetal QRS (FQRS) complexes in terms of location. A small subset of authors have investigated the extraction of morphological features from the NI-FECG. However, due to the shortage of available public databases, the large variety of performance measures employed and the lack of open-source reference algorithms, most contributions cannot be meaningfully assessed. This article attempts to address these issues by presenting a standardised methodology for stress testing NI-FECG algorithms, including absolute data, as well as extraction and evaluation routines. To that end, a large database of realistic artificial signals was created, totaling 145.8 h of multichannel data and over one million FQRS complexes. An important characteristic of this dataset is the inclusion of several non-stationary events (e.g. foetal movements, uterine contractions and heart rate fluctuations) that are critical for evaluating extraction routines. To demonstrate our testing methodology, three classes of NI-FECG extraction algorithms were evaluated: blind source separation (BSS), template subtraction (TS) and adaptive methods (AM). Experiments were conducted to benchmark the performance of eight NI-FECG extraction algorithms on the artificial database focusing on: FQRS detection and morphological analysis (foetal QT and T/QRS ratio). The overall median FQRS detection accuracies (i.e. considering all non-stationary events) for the best performing methods in each group were 99.9% for BSS, 97.9% for AM and 96.0% for TS. Both FQRS detections and morphological parameters were shown to heavily depend on the extraction techniques and signal-to-noise ratio. Particularly, it is shown that their evaluation in the source domain, obtained after using a BSS technique, should be

  8. Thermal-stress analysis and testing of DIII-D armor tiles

    International Nuclear Information System (INIS)

    Baxi, C.B.; Anderson, P.M.; Reis, E.E.; Smith, J.P.; Smith, P.D.; Croesmann, C.; Watkins, J.; Whitley, J.

    1987-10-01

    It is planned to install about 1500 new armor tiles in the DIII-D tokamak. The armor tiles currently installed in DIII-D are made by brazing Poco AXF-5Q graphite onto Inconel X-750 stock. A small percentage of these have failed by breakage of graphite. These failures were believed to be related to significant residual stress remaining in graphite after brazing. Hence, an effort was undertaken to improve the design with all-graphite tiles. Three criteria must be satisfied by the armor tiles and the hardware used to attach the tiles to the vessel walls: tiles should not structurally fail, peak tile temperature must be less than 2500 K, and peak vessel stresses must be below acceptable levels. A number of alternate design concepts were first analyzed with the two-dimensional finite element codes TOPAZ2D and NIKE2D. Promising designs were optimized for best parameters such as thicknesses, etc. The two best designs were further analyzed for thermal stresses with the three-dimensional codes P/THERMAL and P/STRESS. Prototype tiles of a number of materials were fabricated by GA and tested at the Plasma Materials Test Facility of the Sandia National Laboratory at Albuquerque. The tests simulated the heat flux and cooling conditions in DIII-D. This paper describes the 2-D and 3-D thermal stress analyses, the test results and logic which led to the selected design of the DIII-D armor tiles. 5 refs., 7 figs., 3 tabs

  9. Business model stress testing : A practical approach to test the robustness of a business model

    NARCIS (Netherlands)

    Haaker, T.I.; Bouwman, W.A.G.A.; Janssen, W; de Reuver, G.A.

    Business models and business model innovation are increasingly gaining attention in practice as well as in academic literature. However, the robustness of business models (BM) is seldom tested vis-à-vis the fast and unpredictable changes in digital technologies, regulation and markets. The

  10. Exploratory rearing: a context- and stress-sensitive behavior recorded in the open-field test.

    Science.gov (United States)

    Sturman, Oliver; Germain, Pierre-Luc; Bohacek, Johannes

    2018-02-16

    Stressful experiences are linked to anxiety disorders in humans. Similar effects are observed in rodent models, where anxiety is often measured in classic conflict tests such as the open-field test. Spontaneous rearing behavior, in which rodents stand on their hind legs to explore, can also be observed in this test yet is often ignored. We define two forms of rearing, supported rearing (in which the animal rears against the walls of the arena) and unsupported rearing (in which the animal rears without contacting the walls of the arena). Using an automated open-field test, we show that both rearing behaviors appear to be strongly context dependent and show clear sex differences, with females rearing less than males. We show that unsupported rearing is sensitive to acute stress, and is reduced under more averse testing conditions. Repeated testing and handling procedures lead to changes in several parameters over varying test sessions, yet unsupported rearing appears to be rather stable within a given animal. Rearing behaviors could therefore provide an additional measure of anxiety in rodents relevant for behavioral studies, as they appear to be highly sensitive to context and may be used in repeated testing designs.

  11. Heat conduction

    International Nuclear Information System (INIS)

    Grigull, U.; Sandner, H.

    1984-01-01

    Included are discussions of rates of heat transfer by conduction, the effects of varying and changing properties, thermal explosions, distributed heat sources, moving heat sources, and non-steady three-dimensional conduction processes. Throughout, the importance of thinking both numerically and symbolically is stressed, as this is essential to the development of the intuitive understanding of numerical values needed for successful designing. Extensive tables of thermophysical properties, including thermal conductivity and diffusivity, are presented. Also included are exact and approximate solutions to many of the problems that arise in practical situations

  12. [Autopsy and blood testing for alcohol and drugs/medicine after traffic fatalities is not routinely conducted].

    Science.gov (United States)

    Uhrenholt, Lars; Schumacher, Bente; Freeman, Michael

    2010-09-27

    In some road traffic crashes with fatal outcome, the police investigations lead to charges against and prosecution of a person. The police can request a medico-legal autopsy as well as a toxicological examination, but the extent to which this is done, and the role here of in the legal setting is unknown. Information concerning traffic crashes with fatal outcome in the period 2000-2004 in Aarhus Police District was retrieved and compared. The information included comprised crash specific and legal information, as well as medical data concerning autopsy, examination for alcohol, drugs and/or medicine. In all, 81 traffic crashes had a fatal outcome for 92 persons, of whom 17 (18%) were autopsied, 55 (60%) were tested for alcohol, and five (5%) were examined for drugs/medicine. Twenty-six were charged with negligent homicide, of which 18 were convicted. Autopsy was performed in four of these cases, 19 were tested for alcohol and one was tested for drugs/medicine. This study shows that the police requests few medico-legal autopsies following road traffic fatalities, and that testing for alcohol as well as drugs/medicine is not conducted routinely. As a consequence, important information may not come to the knowledge of the police in cases of negligent homicide. We recommend that postmortem examination be conducted routinely in traffic-related homicide cases to secure the best possible conditions for a legal evaluation.

  13. Stress corrosion test of Al- Zn- Mg alloys with and without Nb

    International Nuclear Information System (INIS)

    Pereira, E.C.; Garlipp, W.

    1982-01-01

    Two aluminium alloys 1 and 2 with the respectives compositions 6,10 wt% Zn; 1,58 wt% Mg; 0,24 wt% Cu and 6,25 wt% Zn; 2,03 wt% Mg; 0,24 wt% Cu; 0,078 wt% Nb, was cast, annealed, extruded and cold rolled to 10% of the initial area. Samples was made for tensile testing and stress corrosion cracking in accord with the recommended standard test. After quench from 460 0 C they was preaged at 100 0 C, 6 hours and aged again at 160 0 C in different times. The tests revealed better properties for the alloys 2. (Author) [pt

  14. Impacts of water stress, environment and rootstock on the diurnal behaviour of stem water potential and leaf conductance in pistachio (Pistacia vera L.)

    International Nuclear Information System (INIS)

    Memmi, H.; Couceiro, J.F.; Gijón, C.; Pérez-López, D.

    2016-01-01

    Little information is available on the diurnal behaviour of water potential and leaf conductance on pistachio trees despite their relevance to fine tune irrigation strategies. Mature pistachio trees were subject to simultaneous measurements of stem water potential (Ψx) and leaf conductance (gl) during the day, at three important periods of the irrigation season. Trees were grown on three different rootstocks and water regimes. An initial baseline relating Ψx to air vapor pressure deficit (VPD) is presented for irrigation scheduling in pistachio. Ψx was closely correlated with VPD but with a different fit according to the degree of water stress. No evidence of the variation of Ψx in relation to the phenology of the tree was observed. Furthermore, midday Ψx showed more accuracy to indicate a situation of water stress than predawn water potential. Under well irrigated conditions, gl was positively correlated with VPD during stage II of growth reaching its peak when VPD reached its maximum value (around 4 kPa). This behaviour changed during stage III of fruit growth suggesting a reliance of stomatal behaviour to the phenological stage independently to the tree water status. The levels of water stress reached were translated in a slow recovery of tree water status and leaf conductance (more than 40 days). Regarding rootstocks, P. integerrima showed little adaptation to water shortage compared to the two other rootstocks under the studied conditions. (Author)

  15. Impacts of water stress, environment and rootstock on the diurnal behaviour of stem water potential and leaf conductance in pistachio (Pistacia vera L.

    Directory of Open Access Journals (Sweden)

    Houssem Memmi

    2016-06-01

    Full Text Available Little information is available on the diurnal behaviour of water potential and leaf conductance on pistachio trees despite their relevance to fine tune irrigation strategies. Mature pistachio trees were subject to simultaneous measurements of stem water potential (Ψx and leaf conductance (gl during the day, at three important periods of the irrigation season. Trees were grown on three different rootstocks and water regimes. An initial baseline relating Ψx to air vapor pressure deficit (VPD is presented for irrigation scheduling in pistachio. Ψx was closely correlated with VPD but with a different fit according to the degree of water stress. No evidence of the variation of Ψx in relation to the phenology of the tree was observed. Furthermore, midday Ψx showed more accuracy to indicate a situation of water stress than predawn water potential. Under well irrigated conditions, gl was positively correlated with VPD during stage II of growth reaching its peak when VPD reached its maximum value (around 4 kPa. This behaviour changed during stage III of fruit growth suggesting a reliance of stomatal behaviour to the phenological stage independently to the tree water status. The levels of water stress reached were translated in a slow recovery of tree water status and leaf conductance (more than 40 days. Regarding rootstocks, P. integerrima showed little adaptation to water shortage compared to the two other rootstocks under the studied conditions.

  16. Impacts of water stress, environment and rootstock on the diurnal behaviour of stem water potential and leaf conductance in pistachio (Pistacia vera L.)

    Energy Technology Data Exchange (ETDEWEB)

    Memmi, H.; Couceiro, J.F.; Gijón, C.; Pérez-López, D.

    2016-11-01

    Little information is available on the diurnal behaviour of water potential and leaf conductance on pistachio trees despite their relevance to fine tune irrigation strategies. Mature pistachio trees were subject to simultaneous measurements of stem water potential (Ψx) and leaf conductance (gl) during the day, at three important periods of the irrigation season. Trees were grown on three different rootstocks and water regimes. An initial baseline relating Ψx to air vapor pressure deficit (VPD) is presented for irrigation scheduling in pistachio. Ψx was closely correlated with VPD but with a different fit according to the degree of water stress. No evidence of the variation of Ψx in relation to the phenology of the tree was observed. Furthermore, midday Ψx showed more accuracy to indicate a situation of water stress than predawn water potential. Under well irrigated conditions, gl was positively correlated with VPD during stage II of growth reaching its peak when VPD reached its maximum value (around 4 kPa). This behaviour changed during stage III of fruit growth suggesting a reliance of stomatal behaviour to the phenological stage independently to the tree water status. The levels of water stress reached were translated in a slow recovery of tree water status and leaf conductance (more than 40 days). Regarding rootstocks, P. integerrima showed little adaptation to water shortage compared to the two other rootstocks under the studied conditions. (Author)

  17. Operational Review of the First Wireline In Situ Stress Test in Scientific Ocean Drilling

    Directory of Open Access Journals (Sweden)

    Casey Moore

    2012-04-01

    Full Text Available Scientific ocean drilling’s first in situ stress measurement was made at Site C0009A during Integrated Ocean Drilling Program (IODP Expedition 319 as part of Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE Stage 2. The Modular Formation Dynamics Tester (MDT, Schlumbergerwireline logging tool was deployed in riser Hole C0009A to measure in situ formation pore pressure, formation permeability (often reported as mobility=permeability/viscosity, and the least principal stress (S3 at several isolated depths (Saffer et al., 2009; Expedition 319 Scientists, 2010. The importance of in situ stress measurements is not only for scientific interests in active tectonic drilling, but also for geomechanical and well bore stability analyses. Certain in situ tools were not previously available for scientific ocean drilling due to the borehole diameter and open hole limits of riserless drilling. The riser-capable drillship, D/V Chikyu,now in service for IODP expeditions, allows all of the techniques available to estimate the magnitudes and orientations of 3-D stresses to be used. These techniques include downhole density logging for vertical stress, breakout and caliper log analyses for maximum horizontal stress, core-based anelastic strain recovery (ASR, used in the NanTroSEIZE expeditions in 2007–2008, and leak-off test (Lin et al., 2008 and minifrac/hydraulic fracturing (NanTroSEIZE Expedition319 in 2009. In this report, the whole operational planning process related to in situ measurements is reviewed, and lessons learned from Expedition 319 are summarized for efficient planning and testing in the future.

  18. Comparison of the Morel Emotional Numbing Test for Posttraumatic Stress Disorder to the Word Memory Test in neuropsychological evaluations.

    Science.gov (United States)

    Morel, Kenneth R

    2008-03-01

    The most commonly feigned cognitive and psychiatric disorders for survivors of traumatic injury are memory dysfunction and posttraumatic stress disorder (PTSD). The position of the National Academy of Neuropsychology is that symptom validity tests (SVTs) should be part of any comprehensive neuropsychological evaluation. In this article the Morel Emotional Numbing Test for Posttraumatic Stress Disorder (MENT), a SVT for PTSD, was compared to a SVT for memory, the Word Memory Test (WMT). Available archival data on 216 consecutive referrals for neuropsychological evaluations at the Veterans Affairs Tennessee Valley Healthcare System were reviewed. Of the total records reviewed 37 patients had been administered both the MENT and the WMT. The clinically recommended cutoff on the WMT was used as the main criterion to classify patients into two groups: simulating impairment or credible. The results indicated that the simulating impairment group had significantly more errors on the MENT than the credible group did (p <.0001). The criterion-related characteristics of the MENT in assessing response bias in relation to the WMT were confirmed Clinical and research implications of the utilization of the MENT are discussed in this study.

  19. Knowledge of HIV and willingness to conduct oral rapid HIV testing among dentists in Xi'an China.

    Directory of Open Access Journals (Sweden)

    Lirong Wang

    Full Text Available China is considered a country of low HIV prevalence (780,000 people living with HIV, however, HIV infections among high-risk populations continue to grow at alarming rates. Voluntary Counseling and Testing services were first implemented in 2003, and oral rapid HIV testing (ORHT began in 2012. Dentists, as oral health experts, would be well placed to conduct ORHT. We assessed willingness of dentists to undertake ORHT in their clinical practice.A cross-sectional, paper-based survey of dentists from the Xi'an region of China was conducted from April to June 2013. Dentists were recruited from Shaanxi Stomatological Association using a stratified sampling methodology. A 40-item survey was used to measure knowledge of HIV, attitudes toward people living with HIV and willingness to conduct ORHT.477 dentists completed the survey with a mean HIV knowledge test score of 13.2/18 (SD 1.9. If made available in the dental setting, 276 (57.9% preferred to use blood to diagnose HIV, only 190 (39.8% preferred saliva or both. Four hundred and thirty-five (91.2% thought that ORHT was needed in dental clinics. Female dentists felt more accepting of ORHT than males (93.8% vs. 87.8%; χ2=5.145; p<0.05. 42.6% of the participants who responded thought that lack of education on ORHT for dentists was the most urgent problem to solve for ORHT, 144 (31.3% thought that lack of support for ORHT from patients was the most urgent problem. There was statistically significant difference among dental hospital, dentistry and department of dentistry (χ2=24.176; p<0.05.The majority of Chinese dentists thought that ORHT was needed in the dental setting. Providing opportunities for dentists and dental students to learn about HIV testing guidelines and practices is needed as well as feasibility and implementation science research.

  20. Comparison between the results of stress relaxation - and creep tests in a stainless steel 316 at 8000C

    International Nuclear Information System (INIS)

    Miranda, P.E.V. de.

    1978-07-01

    A sequence of stress relaxation tests from the same initial stress showed an estabilization of the relaxed fraction of stress of a 316 stainless steel at 800 0 C. This represents the exhaustion of the deformation process of the material at this temperature. Results from the relaxation tests were obtained by utilizing a recently proposed model. The slope in from the log epsilon sup(.) x logσ/E curve obtained by relaxation (n = 6,80) closely matched that determined by creep tests (n = 6,50). This presents a possibility of determined by stress relaxation of the parameters usually calculated by creep. (Author) [pt

  1. Investigating psychological and physiological responses to the Trier Social Stress Test in young adults with insomnia.

    Science.gov (United States)

    Chen, Ivy Y; Jarrin, Denise C; Ivers, Hans; Morin, Charles M

    2017-12-01

    Stress and hyperarousal both contribute to insomnia. Elevated stress-related sleep reactivity is associated with hyperarousal, and might constitute a vulnerability to future insomnia. The present study examined acute stress-induced arousal and its association with nocturnal sleep. Participants were 30 healthy adults (66.7% female, M age  = 26.7 years): 10 with insomnia (INS) and 20 good sleepers with high vulnerability (HV) or low vulnerability (LV) to insomnia. They underwent two consecutive nights of polysomnography. During the evening preceding the second night, the Trier Social Stress Test (TSST) was administered, and psychological and physiological arousal indices were assessed. The TSST elicited an increase in psychological and physiological arousal in all three groups. The INS group showed greater acute cortisol response (p stress reactivity and bedtime hyperarousal might represent a trait-like vulnerability in certain good sleepers. More research is warranted to validate and expand these preliminary findings. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Relationship between electrical conductivity anisotropy and fabric anisotropy in granular materials during drained triaxial compressive tests: a numerical approach

    Science.gov (United States)

    Niu, Qifei; Revil, André; Li, Zhaofeng; Wang, Yu-Hsing

    2017-07-01

    The anisotropy of granular media and its evolution during shearing are important aspects required in developing physics-based constitutive models in Earth sciences. The development of relationships between geoelectrical properties and the deformation of porous media has applications to the monitoring of faulting and landslides. However, such relationships are still poorly understood. In this study, we first investigate the definition of the electrical conductivity anisotropy tensor of granular materials in presence of surface conductivity of the grains. Fabric anisotropy is related to the components of the fabric tensor. We define an electrical anisotropy factor based on the Archie's exponent second-order symmetric tensor m of granular materials. We use numerical simulations to confirm a relationship between the evolution of electrical and fabric anisotropy factors during shearing. To realize the simulations, we build a virtual laboratory in which we can easily perform synthetic experiments. We first simulate drained compressive triaxial tests of loose and dense granular materials (porosity 0.45 and 0.38, respectively) using the discrete element method. Then, the electrical conductivity tensor of a set of deformed synthetic samples is computed using the finite-difference method. The numerical results show that shear strains are responsible for a measurable anisotropy in the bulk conductivity of granular media. The observed electrical anisotropy response, during shearing, is distinct for dense and loose synthetic samples. Electrical and fabric anisotropy factors exhibit however a unique linear correlation, regardless of the shear strain and the initial state (porosity) of the synthetic samples. The practical implication of this finding confirms the usefulness of the electrical conductivity method in studying the fabric tensor of granular media. This result opens the door in using time-lapse electrical resistivity to study non-intrusively the evolution of anisotropy

  3. R6 validation exercise: through thickness residual stress measurements on an experiment test vessel ring

    International Nuclear Information System (INIS)

    Mitchell, D.H.

    1988-06-01

    A series of bursting tests on thick-walled pressure vessels has been carried out as part of a validation exercise for the CEGB R6 failure assessment procedure. The objective of these tests was the examination of the behaviour of typical PWR primary vessel material subject to residual stresses in addition to primary loading with particular reference to the R6 assessment procedure. To this end, a semi-elliptic part-through defect was sited in the vessel longitudinal seam, which was a submerged arc weld in the non stress-relieved condition; it was then pressure tested to failure. Prior to the final assembly of this vessel, a ring of material was cut from it to act as a test-piece on which a residual stress survey could be made. Surface measurements using the centre-hole technique were made by CERL personnel, and this has been followed by two through- thickness measurements at BNL using the deep-hole technique. This paper describes these deep-hole measurements and presents the results from them. (author)

  4. Sex ratios in the two Germanies: a test of the economic stress hypothesis.

    Science.gov (United States)

    Catalano, Ralph A

    2003-09-01

    Literature describing temporal variation in the secondary sex ratio among humans reports an association between population stressors and declines in the odds of male birth. Explanations of this phenomenon draw on reports that stressed females spontaneously abort male more than female fetuses, and that stressed males exhibit reduced sperm motility. This work has led to the argument that population stress induced by a declining economy reduces the human sex ratio. No direct test of this hypothesis appears in the literature. Here, a test is offered based on a comparison of the sex ratio in East and West Germany for the years 1946 to 1999. The theory suggests that the East German sex ratio should be lower in 1991, when East Germany's economy collapsed, than expected from its own history and from the sex ratio in West Germany. The hypothesis is tested using time-series modelling methods. The data support the hypothesis. The sex ratio in East Germany was at its lowest in 1991. This first direct test supports the hypothesis that economic decline reduces the human sex ratio.

  5. Life prediction of OLED for constant-stress accelerated degradation tests using luminance decaying model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jianping, E-mail: jpzhanglzu@163.com [College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Li, Wenbin [College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Cheng, Guoliang; Chen, Xiao [Shanghai Tianyi Electric Co., Ltd., Shanghai 201611 (China); Wu, Helen [School of Computing, Engineering and Mathematics, University of Western Sydney, Sydney 2751 (Australia); Herman Shen, M.-H. [Department of Mechanical and Aerospace Engineering, The Ohio State University, OH 43210 (United States)

    2014-10-15

    In order to acquire the life information of organic light emitting diode (OLED), three groups of constant stress accelerated degradation tests are performed to obtain the luminance decaying data of samples under the condition that the luminance and the current are respectively selected as the indicator of performance degradation and the test stress. Weibull function is applied to describe the relationship between luminance decaying and time, least square method (LSM) is employed to calculate the shape parameter and scale parameter, and the life prediction of OLED is achieved. The numerical results indicate that the accelerated degradation test and the luminance decaying model reveal the luminance decaying law of OLED. The luminance decaying formula fits the test data very well, and the average error of fitting value compared with the test data is small. Furthermore, the accuracy of the OLED life predicted by luminance decaying model is high, which enable rapid estimation of OLED life and provide significant guidelines to help engineers make decisions in design and manufacturing strategy from the aspect of reliability life. - Highlights: • We gain luminance decaying data by accelerated degradation tests on OLED. • The luminance decaying model objectively reveals the decaying law of OLED luminance. • The least square method (LSM) is employed to calculate Weibull parameters. • The plan designed for accelerated degradation tests proves to be feasible. • The accuracy of the OLED life and the luminance decaying fitting formula is high.

  6. Life prediction of OLED for constant-stress accelerated degradation tests using luminance decaying model

    International Nuclear Information System (INIS)

    Zhang, Jianping; Li, Wenbin; Cheng, Guoliang; Chen, Xiao; Wu, Helen; Herman Shen, M.-H.

    2014-01-01

    In order to acquire the life information of organic light emitting diode (OLED), three groups of constant stress accelerated degradation tests are performed to obtain the luminance decaying data of samples under the condition that the luminance and the current are respectively selected as the indicator of performance degradation and the test stress. Weibull function is applied to describe the relationship between luminance decaying and time, least square method (LSM) is employed to calculate the shape parameter and scale parameter, and the life prediction of OLED is achieved. The numerical results indicate that the accelerated degradation test and the luminance decaying model reveal the luminance decaying law of OLED. The luminance decaying formula fits the test data very well, and the average error of fitting value compared with the test data is small. Furthermore, the accuracy of the OLED life predicted by luminance decaying model is high, which enable rapid estimation of OLED life and provide significant guidelines to help engineers make decisions in design and manufacturing strategy from the aspect of reliability life. - Highlights: • We gain luminance decaying data by accelerated degradation tests on OLED. • The luminance decaying model objectively reveals the decaying law of OLED luminance. • The least square method (LSM) is employed to calculate Weibull parameters. • The plan designed for accelerated degradation tests proves to be feasible. • The accuracy of the OLED life and the luminance decaying fitting formula is high

  7. Coordination of stem and leaf hydraulic conductance in southern California shrubs: a test of the hydraulic segmentation hypothesis.

    Science.gov (United States)

    Pivovaroff, Alexandria L; Sack, Lawren; Santiago, Louis S

    2014-08-01

    Coordination of water movement among plant organs is important for understanding plant water use strategies. The hydraulic segmentation hypothesis (HSH) proposes that hydraulic conductance in shorter lived, 'expendable' organs such as leaves and longer lived, more 'expensive' organs such as stems may be decoupled, with resistance in leaves acting as a bottleneck or 'safety valve'. We tested the HSH in woody species from a Mediterranean-type ecosystem by measuring leaf hydraulic conductance (Kleaf) and stem hydraulic conductivity (KS). We also investigated whether leaves function as safety valves by relating Kleaf and the hydraulic safety margin (stem water potential minus the water potential at which 50% of conductivity is lost (Ψstem-Ψ50)). We also examined related plant traits including the operating range of water potentials, wood density, leaf mass per area, and leaf area to sapwood area ratio to provide insight into whole-plant water use strategies. For hydrated shoots, Kleaf was negatively correlated with KS , supporting the HSH. Additionally, Kleaf was positively correlated with the hydraulic safety margin and negatively correlated with the leaf area to sapwood area ratio. Consistent with the HSH, our data indicate that leaves may act as control valves for species with high KS , or a low safety margin. This critical role of leaves appears to contribute importantly to plant ecological specialization in a drought-prone environment. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  8. 78 FR 72534 - Policy Statement on the Principles for Development and Distribution of Annual Stress Test Scenarios

    Science.gov (United States)

    2013-12-03

    ... FEDERAL DEPOSIT INSURANCE CORPORATION 12 CFR Part 325 Policy Statement on the Principles for... stress test horizon. The variables specified for each scenario generally address economic activity, asset..., 2012, that articulated the principles the FDIC will apply to develop and distribute the stress test...

  9. Room-Temperature Voltage Stressing Effects on Resistive Switching of Conductive-Bridging RAM Cells with Cu-Doped SiO2 Films

    Directory of Open Access Journals (Sweden)

    Jian-Yang Lin

    2014-01-01

    Full Text Available SiO2 or Cu-doped SiO2 (Cu:SiO2 insulating films combined with Cu or W upper electrodes were constructed on the W/Si substrates to form the conductive-bridging RAM (CB-RAM cells. The CB-RAMs were then subjected to a constant-voltage stressing (CVS at room temperature. The experimental results show that the room-temperature CVS treatment can effectively affect the current conduction behavior and stabilize the resistive switching of the memory cells. After the CVS, the current conduction mechanisms in the high resistance state during the set process of the Cu/Cu:SiO2/W cell can be changed from Ohm’s law and the space charge limited conduction to Ohm’s law, the Schottky emission, and the space charge limited conduction. Presumably, it is due to the breakage of the conduction filaments during the CVS treatment that the conduction electrons cannot go back to the back electrode smoothly.

  10. Cortisol response to the Trier Social Stress test among Chinese adolescents.

    Science.gov (United States)

    Fu, Jiling; Weng, Tingting; Tao, Fangbiao

    2012-01-01

    To compare obese and non-obese adolescents in terms of their salivary cortisol response to the Trier Socia l Stress Test ( TSST). This is a cross - sectional study involving 41 healthy adolescents aged 12-14 years in the city of Shenyang, China. The TSST response was determined using salivary cortisol measurements, and measurements were repeated after the test period. Repeated-measures ANOVA was performed to compare salivary cortisol levels between groups. The male group comprised of 16 individuals (10 obese and 6 non-obese), and the female group comprised 25 individuals ( 13 obese and 12 non-obese). ANOVA with repeated measures demonstrated that weight status (obese or non-obese) had a significant main effect on the measures of salivary cortisol levels during the TSST among females but not males. The finding suggested that weight status is associated with cortisol response to psychological stress among Chinese adolescent girls.

  11. Test report on experimental stress analysis of a 24 inch diameter tee (ORNL T-12)

    International Nuclear Information System (INIS)

    Henley, D.R.

    1975-04-01

    The experimental stress analysis and low cycle fatigue test of one 24'' x 24'' x 10'' schedule 40 carbon steel, ANSI B16.9 tee performed by Combustion Engineering, Inc. is described. The tee was instrumented with 230 rectangular strain gage rosettes. Elastic data was obtained for 12 loading conditions consisting of internal pressure and orthogonal pure moments and orthogonal direct forces applied individually to the free branch and run ends of the tee. One of the run ends of the tee was ''built in'' throughout the test. All loads were applied through pipe extensions welded to the tee. The tee was tested to failure in a low cycle pressure fatigue test with a cyclic internal pressure between 0 psi and 1800 psi. A through-the-wall fatigue crack occurred at 76620 cycles. Significant test results are summarized and compared with design values tabulated in the ASME Boiler and Pressure Vessel Code, Section III, 1971. (U.S.)

  12. Opioid/NMDA receptors blockade reverses the depressant-like behavior of foot shock stress in the mouse forced swimming test.

    Science.gov (United States)

    Haj-Mirzaian, Arya; Ostadhadi, Sattar; Kordjazy, Nastaran; Dehpour, Ahmad Reza; Ejtemaei Mehr, Shahram

    2014-07-15

    Opioid and glutamatergic receptors have a key role in depression following stress. In this study, we assessed opioid and glutamatergic receptors interaction with the depressant-like behavior of acute foot-shock stress in the mouse forced swimming test. Stress was induced by intermittent foot shock stimulation during 30min and swim periods were afterwards conducted by placing mice in separated glass cylinders filled with water for 6min. The immobility time during the last 4min of the test was considered. Acute foot-shock stress significantly increased the immobility time of mice compared to non-stressed control group (P≤0.01). Administration of non-selective opioid receptors antagonist, naltrexone (1 and 2mg/kg, i.p.), and the selective non-competitive NMDA receptor antagonist, MK-801 (0.05mg/kg, i.p.), and the selective serotonin reuptake inhibitor, fluoxetine (5mg/kg), significantly reduced the immobility time in stressed animals (P≤0.01). Lower doses of MK-801 (0.01mg/kg), naltrexone (0.3mg/kg), NMDA (75mg/kg) and morphine(5mg/kg) had no effect on foot-shock stressed mice. Combined treatment of sub-effective doses of naltrexone and MK-801 significantly showed an antidepressant-like effect (P≤0.001). On the other hand, co-administration of non-effective doses of NMDA and morphine with effective doses of naltrexone and MK-801 reversed the anti-immobility effect of these drugs. Taken together, we have for the first time demonstrated the possible role of opioid/NMDA receptors signaling in the depressant-like effect of foot-shock stress, and proposed the use of drugs that act like standard anti-depressants in stress-induced depression. Copyright © 2014. Published by Elsevier B.V.

  13. Trends in referral patterns, invasive management, and mortality in elderly patients referred for exercise stress testing.

    Science.gov (United States)

    Bouzas-Mosquera, Alberto; Peteiro, Jesús; Broullón, Francisco J; Calviño-Santos, Ramón; Mosquera, Víctor X; Barbeito-Caamaño, Cayetana; Larrañaga-Moreira, José María; Maneiro-Melón, Nicolás; Álvarez-García, Nemesio; Vázquez-Rodríguez, José Manuel

    2015-12-01

    Scarce data are available on the temporal patterns in clinical characteristics and outcomes of elderly patients referred for exercise stress testing. We aimed to assess the trends in baseline characteristics, tests results, referrals for invasive management, and mortality in these patients. We evaluated 11,192 patients aged ≥65years who were referred for exercise stress testing between January 1998 and December 2013. Calendar years were grouped into four quadrennia (1998-2001, 2002-2005, 2006-2009, and 2010-2013), and trends in clinical characteristics of the patients, type and results of the tests, referrals for invasive management, and mortality across the different periods were assessed. Despite a progressive decrease in the proportion of patients with non-interpretable baseline electrocardiograms or prior history of coronary artery disease, there was a gradual and marked increase in the use of cardiac imaging from 32.8% in 1998-2001 to 67.6% in 2010-2013 (pstress testing both without imaging (from 18.9 to 13.6%, pstress testing, we observed a decline over time in the probability of inducible myocardial ischemia, an increase in the use of cardiac imaging and in the rate of coronary revascularization, and an improvement in the survival rate at 1year. Copyright © 2015 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  14. Employee stress status during the past decade (1982-1992) based on a nation-wide survey conducted by the Ministry of Labour in Japan.

    Science.gov (United States)

    Shimizu, Y; Makino, S; Takata, T

    1997-07-01

    In this paper we will report the results of nation-wide surveys on employee health conducted and published by the Ministry of Labour in 1982, 1987, and 1992. The subjects were approximately 20,000 employees in 1982, approximately 15,000 in 1987, and approximately 16,000 in 1992, from throughout Japan. Using the results of the surveys, we will show trends in the status of employee work-related stress, as well as trends in means of relaxation over the past decade. The percentage of employees with work-related stress among all subjects gradually increased as follows: 50.6% in 1982, 55.0% in 1987, and 57.3% in 1992. The percentage of employees with work-related stress increased remarkably from 1982 through 1992 among the following groups: the 50-59 age group in males; employees in the electricity, gas, heat and water-supply industries; those in the real estate industry; administrative and managerial workers; employees of large establishments with more than 5,000 employees; and employees performing shift work involving no night duty. The problem of "human relationships in the workplace" was associated with the increasing stress levels among 50-59-year-old males, 40-49-year-old females, employees of large establishments with more than 5,000 employees, those in the real estate industry, and service workers. In terms of means of relaxing to relieve fatigue and stress, employees tended to engage in active pursuits such as "eating out and shopping" and "driving and traveling" over the past decade. In 1992, on the other hand, 22.0% of males and 5.9% of females selected "smoking" as a means of relaxation. This shows the need for stress management in the workplace in order to prevent health problems related to smoking.

  15. Wheat cultivars selected for high Fv /Fm under heat stress maintain high photosynthesis, total chlorophyll, stomatal conductance, transpiration and dry matter.

    Science.gov (United States)

    Sharma, Dew Kumari; Andersen, Sven Bode; Ottosen, Carl-Otto; Rosenqvist, Eva

    2015-02-01

    The chlorophyll fluorescence parameter Fv /Fm reflects the maximum quantum efficiency of photosystem II (PSII) photochemistry and has been widely used for early stress detection in plants. Previously, we have used a three-tiered approach of phenotyping by Fv /Fm to identify naturally existing genetic variation for tolerance to severe heat stress (3 days at 40°C in controlled conditions) in wheat (Triticum aestivum L.). Here we investigated the performance of the previously selected cultivars (high and low group based on Fv /Fm value) in terms of growth and photosynthetic traits under moderate heat stress (1 week at 36/30°C day/night temperature in greenhouse) closer to natural heat waves in North-Western Europe. Dry matter accumulation after 7 days of heat stress was positively correlated to Fv /Fm . The high Fv /Fm group maintained significantly higher total chlorophyll and net photosynthetic rate (PN ) than the low group, accompanied by higher stomatal conductance (gs ), transpiration rate (E) and evaporative cooling of the leaf (ΔT). The difference in PN between the groups was not caused by differences in PSII capacity or gs as the variation in Fv /Fm and intracellular CO2 (Ci ) was non-significant under the given heat stress. This study validated that our three-tiered approach of phenotyping by Fv /Fm performed under increasing severity of heat was successful in identifying wheat cultivars differing in photosynthesis under moderate and agronomically more relevant heat stress. The identified cultivars may serve as a valuable resource for further studies to understand the physiological mechanisms underlying the genetic variability in heat sensitivity of photosynthesis. © 2014 Scandinavian Plant Physiology Society.

  16. Refinement of parameters of weak nuclear explosions conducted at the Semipalatinsk test site on the basis of historical seismograms study

    Science.gov (United States)

    Sokolova, Inna

    2014-05-01

    Many researchers working in the field of monitoring and discriminating of nuclear tests encounter the problem of lacking in seismic catalogues the information about source parameters for weak nuclear explosions. As usual, the information about origin time, coordinates and magnitude is absent, there is information about date, approximate coordinates and information about explosion yield. Huge work conducted on recovery of parameters of small underground nuclear explosions conducted at the Semipalatinsk Test Site using records of analogue seismic stations of the USSR located at regional distances was conducted by V. Khalturin, T. Rayutian, P. Richards (Pure and Applied Geophysics, 2001). However, if underground nuclear explosions are studied and described in literature quite well, then air and contact explosions were small and were not recorded by standard permanent seismic stations. In 1961-1962 maximum number of air and contact explosions was conducted at Opytnoye polye site of the STS. We managed to find and analyze additional seismic data from some temporary and permanent stations. That time IPE AS USSR installed a network of high-sensitive stations along Pamir-Baykal profile to study earth crust structure and upper mantle, the profile length was 3500 km. Epicentral distance from some stations of the profile to Opytnoye polye was 300-400 km. In addition, a permanent seismic station Semipalatinsk (SEM) located 175 km away from the site started its operation. The seismograms from this station became available recently. The digitized historical seismograms allowed to recover and add parameters for more than 36 air and surface explosions. Origin time, coordinates, magnitudes mpv, MLV and energy class K were determined for explosions. A regional travel-time curve for Central Kazakhstan constructed using records of calibration chemical explosions conducted at the STS in 1997-2000 and ground-truth underground nuclear explosions was used to determine kinematic parameters

  17. Teste de condutividade elétrica em sementes de soja armazenadas sob diferentes temperaturas Electrical conductivity test of soybean seeds stored under different temperatures

    Directory of Open Access Journals (Sweden)

    Simone Aparecida Fessel

    2010-01-01

    Full Text Available Os resultados do teste de condutividade elétrica podem ser influenciados pela temperatura de armazenamento, particularmente as mais baixas, como em condições de câmara fria (10 ºC. Este trabalho objetivou avaliar o efeito da temperatura e do período de armazenamento na condutividade elétrica e na composição química da solução de embebição de sementes de soja. Para tanto, foram determinados o teor de água, a germinação, o vigor (testes de envelhecimento acelerado, de frio e de condutividade elétrica e a composição química (K+, Ca2+ e Mg2+ da solução de embebição. Foram utilizados dois lotes de sementes, da cultivar FT-20, com níveis distintos de vigor. As avaliações foram realizadas a cada três meses, durante 15 meses. Tanto a temperatura como o período de armazenamento influenciaram o vigor das sementes. A lixiviação dos íons K+, Ca2+ e Mg2+ foi influenciada pelos mesmos fatores. Pelos resultados concluiu-se que o teste de condutividade elétrica não é indicado para avaliar o vigor de sementes de soja armazenadas sob baixa temperatura (10 ºC e o K+ é o íon lixiviado em maior quantidade de semente de soja, independentemente da temperatura de armazenamento.There are some results showing that the electrical conductivity test can be influenced by low temperature of seed storage, such as 10 ºC. This work was carried out in order to study the effect of temperature and period of storage on electrical conductivity and chemical composition of the imbibing solution of soybean seeds. For that, seed water content, germination, vigor (accelerated aging, cold test and electrical conductivity, and chemical composition (K+, Ca2+ and Mg2+ of the imbibing solution were determined. Two soybean seed lots of cultivar FT-20 with high and low vigor were used. The evaluations were performed at every three months intervals, during 15 months. Both temperature and storage period influenced seed vigor, as well as the ions leakage. It

  18. [Isoproterenol stress test for the evaluation of the residual stenosis of the right ventricular outflow tract].

    Science.gov (United States)

    Suzuki, T; Fukuda, T; Kashima, I; Sato, M; Miura, M; Ueda, H; Yoshiba, S

    2001-07-01

    Hemodynamic changes of the right side of the heart during isoproterenol stress test were assessed and analyzed in 36 patients who underwent definitive repair of tetralogy of Fallot or double outlet right ventricle with pulmonary