WorldWideScience

Sample records for stress tests conducted

  1. (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, ...

  2. Standard test methods for conducting creep, creep-rupture, and stress-rupture tests of metallic materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 These test methods cover the determination of the amount of deformation as a function of time (creep test) and the measurement of the time for fracture to occur when sufficient force is present (rupture test) for materials when under constant tensile forces at constant temperature. It also includes the essential requirements for testing equipment. For information of assistance in determining the desirable number and duration of tests, reference should be made to the product specification. 1.2 These test methods list the information which should be included in reports of tests. The intention is to ensure that all useful and readily available information is transmitted to interested parties. Reports receive special attention for the following reasons: (1) results from different, recognized procedures vary significantly; therefore, identification of methods used is important; (2) later studies to establish important variables are often hampered by the lack of detailed information in published reports; (3) t...

  3. What Is Stress Testing?

    Science.gov (United States)

    ... Stress testing provides information about how your heart works during physical stress. Some heart problems are easier to diagnose when ... Testing Show? Stress testing shows how your heart works during physical stress (exercise) and how healthy your heart is. A ...

  4. Nuclear Stress Test

    Science.gov (United States)

    ... Nuclear Stress Test Menu Topics Topics FAQs Nuclear Stress Test A nuclear stress test lets doctors see ... with caffeine, such as coffee, tea, sodas, or chocolate. When you return, doctors will give you another ...

  5. Exercise stress test

    Science.gov (United States)

    ... exercise treadmill; Stress ECG; Exercise electrocardiography; Stress test - exercise treadmill; CAD - treadmill; Coronary artery disease - treadmill; Chest pain - treadmill; Angina - treadmill; Heart disease - ...

  6. 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...

  7. 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.

  8. 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...

  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. 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...

  11. Exercise stress testing

    Science.gov (United States)

    Schuster, B.

    1975-01-01

    Positive maximum stress tests in the management of coronary patients are discussed. It is believed that coronary angiography would be the ultimate test to predict the future of patients with coronary heart disease. Progression of angina, myocardial infarction, and death due to heart disease were analyzed.

  12. 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

  13. 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.

  14. Tests Conducted with Strippable Coatings

    Energy Technology Data Exchange (ETDEWEB)

    K. E. Archibald; R. L. Demmer

    1999-08-01

    This report details the testing and evaluation of several strippable coatings and their use in decontamination. Pentek 604, Bartlett (TLC), and ALARA 1146 were products examined for their overall effectiveness and ease of use. Conclusions were reached about the effective use of these coatings, and field test examples, with radioactive contamination are incorporated.

  15. 77 FR 62417 - Annual Stress Test

    Science.gov (United States)

    2012-10-15

    ... size, complexity, and importance of these covered banks to the safety and soundness of the United... nonmember banks and FDIC-insured state-chartered savings associations with total consolidated assets of more... results of the stress tests. The final rule requires large covered banks to conduct annual stress tests...

  16. 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

  17. 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)

  18. Nuclear stress test

    Science.gov (United States)

    ... to a part of the heart. The most likely cause is a narrowing or blockage of one or more of the arteries that supply your heart muscle. Scarring of the heart muscle due to a previous heart attack. After the test you may need: Angioplasty and ...

  19. 77 FR 16484 - Annual Stress Test

    Science.gov (United States)

    2012-03-21

    ... public comment to implement the requirements in Section 165(i)(2) of the Dodd-Frank Wall Street Reform... to conduct annual stress tests. \\1\\ Dodd-Frank Wall Street Reform and Consumer Protection Act, Public... your comments using only one method. \\2\\ See 77 FR 3166 (January 23, 2012). FOR FURTHER INFORMATION...

  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. Leaf conductance and carbon gain under salt-stressed conditions

    Science.gov (United States)

    Volpe, V.; Manzoni, S.; Marani, M.; Katul, G.

    2011-12-01

    Exposure of plants to salt stress is often accompanied by reductions in leaf photosynthesis and in stomatal and mesophyll conductances. To separate the effects of salt stress on these quantities, a model based on the hypothesis that carbon gain is maximized subject to a water loss cost is proposed. The optimization problem of adjusting stomatal aperture for maximizing carbon gain at a given water loss is solved for both a non-linear and a linear biochemical demand function. A key novel theoretical outcome of the optimality hypothesis is an explicit relationship between the stomatal and mesophyll conductances that can be evaluated against published measurements. The approaches here successfully describe gas-exchange measurements reported for olive trees (Olea europea L.) and spinach (Spinacia oleraceaL.) in fresh water and in salt-stressed conditions. Salt stress affected both stomatal and mesophyll conductances and photosynthetic efficiency of both species. The fresh water/salt water comparisons show that the photosynthetic capacity is directly reduced by 30%-40%, indicating that reductions in photosynthetic rates under increased salt stress are not due only to a limitation of CO2diffusion. An increase in salt stress causes an increase in the cost of water parameter (or marginal water use efficiency) exceeding 100%, analogous in magnitude to findings from extreme drought stress studies. The proposed leaf-level approach can be incorporated into physically based models of the soil-plant-atmosphere system to assess how saline conditions and elevated atmospheric CO2 jointly impact transpiration and photosynthesis.

  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. Stress Testing of Data-Communication Networks

    Science.gov (United States)

    Leucht, Kurt; Bedette, Guy

    2006-01-01

    NetStress is a computer program that stress-tests a data-communication network and components thereof. NetStress comprises two components running, respectively, in a transmitting system and a receiving system connected to a network under test

  4. Accelerated stress testing of terrestrial solar cells

    Science.gov (United States)

    Prince, J. L.; Lathrop, J. W.

    1979-01-01

    A program to investigate the reliability characteristics of unencapsulated low-cost terrestrial solar cells using accelerated stress testing is described. Reliability (or parametric degradation) factors appropriate to the cell technologies and use conditions were studied and a series of accelerated stress tests was synthesized. An electrical measurement procedure and a data analysis and management system was derived, and stress test fixturing and material flow procedures were set up after consideration was given to the number of cells to be stress tested and measured and the nature of the information to be obtained from the process. Selected results and conclusions are presented.

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

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Who conducts DOT alcohol tests? 40.211 Section 40... DRUG AND ALCOHOL TESTING PROGRAMS Alcohol Testing Personnel § 40.211 Who conducts DOT alcohol tests? (a) Screening test technicians (STTs) and breath alcohol technicians (BATs) meeting their respective...

  6. 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.

  7. GENOTYPICALY IDENTIFYING WHEAT MESOPHYLL CONDUCTANCE REGULATION UNDER PROGRESSIVE DROUGHT STRESS

    Directory of Open Access Journals (Sweden)

    Katarina Olsovska

    2016-08-01

    Full Text Available AbstractPhotosynthesis limitation by CO2 flow constraints from sub-stomatal cavities to carboxylation sites in chloroplasts under drought stress conditions is, at least in some plant species or crops not fully understood, yet. Leaf mesophyll conductance for CO2 (gm may considerably affect both photosynthesis and water use efficiency in plants under drought conditions. The aim of our study was to detect the responses of gm in leaves of four winter wheat (Triticum aestivum L. genotypes from different origins under long-term progressive drought. Based on the measurement of gas-exchange parameters the variability of genotypic responses was analyzed at stomatal (stomata closure and non-stomatal (diffusional and biochemical limits of net CO2 assimilation rate (AN. In general, progressive drought caused an increasing leaf diffusion resistance against CO2 flow leading to the decrease of AN, gm and stomatal conductance (gs, respectively. Reduction of gm also led to inhibition of carboxylation efficiency (Vcmax. On the basis of achieved results a strong positive relationship between gm and gs was found out indicating a co-regulation and mutual independence of the relationship under the drought conditions. In severely stressed plants, the stomatal limitation of the CO2 assimilation rate was progressively increased, but to a less extent in comparison to gm, while a non-stomatal limitation became more dominant due to the prolonged drought. Mesophyll conductance (gm seems to be a suitable mechanism and parameter for selection of improved diffusional properties and photosynthetic carbon assimilation in C3 plants, thus explaining their better photosynthetic performance at a whole plant level during periods of drought.

  8. 30 CFR 35.7 - Date for conducting tests.

    Science.gov (United States)

    2010-07-01

    ... APPROVAL OF MINING PRODUCTS FIRE-RESISTANT HYDRAULIC FLUIDS General Provisions § 35.7 Date for conducting tests. The date of acceptance of an application will determine the order of precedence for testing when... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Date for conducting tests. 35.7 Section 35.7...

  9. 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

  10. 30 CFR 27.9 - Date for conducting tests.

    Science.gov (United States)

    2010-07-01

    ... APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS General Provisions § 27.9 Date for conducting tests. The date of receipt of an application will determine the order of precedence for investigation and... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Date for conducting tests. 27.9 Section 27.9...

  11. 30 CFR 33.7 - Date for conducting tests.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Date for conducting tests. 33.7 Section 33.7... APPROVAL OF MINING PRODUCTS DUST COLLECTORS FOR USE IN CONNECTION WITH ROCK DRILLING IN COAL MINES General Provisions § 33.7 Date for conducting tests. The date of acceptance of an application will determine the...

  12. 30 CFR 36.8 - Date for conducting tests.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Date for conducting tests. 36.8 Section 36.8... APPROVAL OF MINING PRODUCTS APPROVAL REQUIREMENTS FOR PERMISSIBLE MOBILE DIESEL-POWERED TRANSPORTATION EQUIPMENT General Provisions § 36.8 Date for conducting tests. The date for acceptance of an application...

  13. 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.

  14. 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.

  15. 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)

  16. 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.

  17. 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.

  18. 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)

  19. 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

  20. Conductivity test in seeds of different passion flower species

    Directory of Open Access Journals (Sweden)

    Sara Mira

    2015-06-01

    Full Text Available The objective of this work was to evaluate the use of the conductivity test as a means of predicting seed viability in seven Passiflora species: P. alata, P. cincinnata, P. edulis f. edulis, P. edulis f. flavicarpa, P. morifolia, P. mucronata, and P. nitida. Conductivity of non-desiccated (control, desiccated, and non-desiccated cryopreserved seeds was determined and related to their germination percentage. The obtained results suggest that the electrical conductivity test has potential as a germination predictor for P. edulis f. flavicarpa seed lots, but not for the other tested species.

  1. 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

  2. Elimination of Potential Electrical Stress During EMC (CS01) Testing

    Science.gov (United States)

    Erickson, Kenneth P.; Whittlesey, Albert C.; Vorperian, Vatche

    2006-01-01

    This viewgraph presentation reviews possible ways to eliminate electrical stress during Electromagneticic Compatibility (EMC) testing. The presentation reviews tests that have had problems due to electrical stress. On December 5, 1995 Cassini Radar instrument failed a functional test in preparation for EMC conducted susceptibility (CSO 1 ) testing. The instrument power supply did not turn on as required, and failure occurred prior to injection of CS test stimulus. A investigation of the failure was conducted. A PSPICE simulation of Cassini Radar 30V line using the EMC test setup was performed; the result of the simulation was an oscillation on the 30V input of the power supply. In another case: on December 28, 1999 an oscillation occurred on the input power line of the SlRTF Infrared Array Camera (IRAC) while preparing to perform CSOI testing, Resulted in damage to flight hardware. Subsequent to failure, JPL provided GSFC history and corrective action from Cassini Radar CSOI test failure GSFC implemented the same corrective action as JPL, except that the value of the resistor connected across the isolation transformer primary winding is 2.5 ohms instead of 50 ohms. Three recommendations are made: (1) Make EMC test community aware of the problem and potential solutions by presenting papers at major environmental test conferences (2) Include warnings and safeguards in EMC test requirements and procedures (3) Try to convince EMC test equipment suppliers to design a CSOl test fixture similar to fixture shown in the diagram

  3. High-Stakes Testing and Teacher Stress

    Science.gov (United States)

    Hoyt, Joshua Paul

    2017-01-01

    The purpose of this mixed-methods research study was to examine how stress levels of middle school mathematics teachers who taught Algebra I in school districts in the state of Pennsylvania relate to high-stakes testing and to explore the experiences of middle school mathematics Algebra I teachers. The researcher collected and compared it to…

  4. 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

  5. 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

  6. Single-well interference slug tests to assess the vertical hydraulic conductivity of unconsolidated aquifers

    Science.gov (United States)

    Paradis, Daniel; Lefebvre, René

    2013-01-01

    SummaryMeaningful understanding of flow and solute transport in general requires the knowledge of hydraulic conductivity and its anisotropy. Various field methods allow the measurement of the horizontal component (Kh), but vertical hydraulic conductivity (Kv) is rarely measured, for lack of practical field tests. This paper proposes vertical interference slug tests, an adaptation of inter-well interference slug tests to a single well, for the efficient field measurement of Kv. The test is carried out in a single well between a stress and an observation interval that are vertically isolated with a three-packer assembly. An instantaneous pressure pulse is induced in the stress interval and resulting drawdowns are recorded in both the stress and the observation intervals. In a proof-of-concept field study, 12 vertical interference tests were carried out sequentially along a fully-screened well across a moderately heterogeneous and highly anisotropic aquifer made up of littoral silts and sands. A direct-push method was used to install the well, which was completed without sand-pack to allow the natural collapse of sediments in the thin annular space around the screen. Direct-push wells allow the measurement of in situ hydraulic properties of sediments and minimize well construction interferences with hydraulic tests. Drawdowns measured in stress and observation intervals of multiple tests were simultaneously inverted numerically to reconstruct heterogeneous profiles of Kh, hydraulic conductivity anisotropy (Kv/Kh), and specific storage (Ss). Results were validated by comparison of observed versus predicted drawdowns and with field and laboratory measurements of Kh and Kv made along the tested well. Results indicate that the profile of Kv values obtained with vertical interference slug tests follows a similar pattern with depth than the profile with lab measurements made with a permeameter on soil samples collected in the same intervals as the interference tests, which

  7. 77 FR 70124 - Policy Statement on the Scenario Design Framework for Stress Testing

    Science.gov (United States)

    2012-11-23

    ... testing that would be used in connection with the supervisory and company-run stress tests conducted under... Policy and Research. SUPPLEMENTARY INFORMATION: Table of Contents I. Background II. Administrative Law... of stress testing as a means to better understand the range of a banking organization's potential...

  8. 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

  9. 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...

  10. Organic Light-Emitting Diodes with Highly Conductive Polymer Electrodes as Anode and Their Stress Tolerance

    Science.gov (United States)

    Kajii, Hirotake; Ohmori, Yutaka; Maki, Hideki; Sekimoto, Yasuhiro; Shigeno, Yasuhiro; Takehara, Naoya; Nakagawa, Hiroshi

    2008-01-01

    The fabrication and characteristics of organic light-emitting diodes (OLEDs) with highly conductive polymer electrodes as an anode and the stress tolerance of the devices fabricated on polymeric substrates were studied. By inserting a wet-processed organic layer between a polymer electrode and a dry-processed hole-transport layer, the surface emission pattern from an OLED was markedly improved. For the device with a wet-processed organic layer (methoxy-substituted 1,3,5-tris[4-(diphenylamino)phenyl]benzene), the uniform surface emission resulted from the uniform applied electric field in the emissive layer and the improvement in interface adherence. The OLED with a wet-processed layer as a hole injection layer showed a maximum luminance and a maximum efficiency of 10,000 cd/m2 and 3.5 cd/A, respectively. For the device fabricated on a polymeric substrate, the impact testing of the OLEDs with highly conductive polymer electrodes [poly(ethylenedioxythiophene):poly(styrene sulfonic acid)] as an anode revealed that the emission lasted for more than several ten thousand steps. A highly conductive polymer electrode had a sufficient tolerance to mechanical stress, as determined by comparing devices with indium tin oxide and a highly conductive polymer as anodes.

  11. Percolation testing and hydraulic conductivity of soils for percolation areas.

    Science.gov (United States)

    Mulqueen, J; Rodgers, M

    2001-11-01

    The results of specific percolation tests are expressed in terms of field saturated hydraulic conductivity (Kfs) of the soil. The specific tests comprise the Irish SR 6 and the UK BS 6297 standard tests and the inversed auger hole and square hole tests employed for the design of land drainage. Percolation times from these tests are converted to Kfs values using unit gradient theory and the Elrick and Reynolds (Soil Sci. 142(5) (1986) 308) model which takes into account gravitational, pressure head and matric potential gradients. Kfs is then expressed as the inverse of the percolation rate times a constant, in this way the percolation rate can be directly related to Kfs of the soil. A plot of Kfs against percolation rate for the Irish SR 6 and the UK BS 6297 standard tests is asymptotic at Kfs values less than 0.2 m/d and greater than 0.8 m/d. This behaviour creates difficulty in setting limits for percolation rates in standards. Curves are provided which enable Kfs values to be read off from percolation tests without the restrictions of head range currently enforced, for example in the Irish SR 6 and BS 6297 standards. Experimental measurements of percolation rates and Kfs were carried out on two sands in the laboratory and in the field on two soils. Kfs of these four materials was also measured using a tension infiltrometer and the Guelph permeameter. The saturated hydraulic conductivities (Ks) of the sands were also estimated in a falling head laboratory apparatus and by the Hazen formula. There was good agreement between the different tests for Kfs on each material. Because percolation time continued to increase significantly in consecutive tests in the same test hole while Kfs became constant, the latter is a better measure of the suitability of soils for percolation.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  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. Magneto-thermo-visco-elastic waves in an initially stressed conducting layer

    International Nuclear Information System (INIS)

    Rakshit, Amit Kumar; Sengupta, P.R.

    1998-01-01

    The aim of this paper is to investigate magneto-thermo-visco-elastic surface waves in electrically and thermally conducting layers involving time rates of strain and stress of order n, the media being under an initial stress in the nature of hydrostatic tension or compression. The theory of magneto-thermo-visco-elastic surface waves in the conducting medium involving strain rate and stress rate of nth order is derived under initial stress. This theory is then employed to obtain wave velocity equations in specific cases. Results obtained in the above cases reduce to well-known classical results when additional fields are absent. (author)

  1. 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.

  2. 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...... (LBNP) to presyncope in 11 passively heat-stressed subjects (increase core temperature: 1.2 ± 0.2°C; means ± SD). Cardiac output was measured via thermodilution, and SVC was calculated while subjects were normothermic, heat stressed, and throughout subsequent LBNP. MAP was not changed by heat stress...

  3. Near-Surface Residual Stress-Profiling with High Frequency Eddy Current Conductivity Measurement

    Science.gov (United States)

    Hillmann, S.; Heuer, H.; Baron, H.-U.; Bamberg, J.; Yashan, A.; Meyendorf, N.

    2009-03-01

    The lifetime of aero engine components can be extended by applying an additional strain to the material. Typical aero engine-alloys like Nickel-Base superalloys or Titanium alloys can be surface-treated by use of shot peening to induce the compressive strain near the surface. However, in order to use the additional life for critical aero engine components, a quantitative determination of strain gradients near the surface has to be carried out periodically. We propose to measure the depth-profile of residual stresses non-destructively by use of high frequency eddy current techniques. This paper presents results obtained with an experimental set-up based on a high precision impedance analyzer. Test samples prepared from IN718 by shot peening of different intensities can be easily distinguished. By sweeping the frequency from 100 kHz up to 100 MHz a depth profile for the electrical conductivity from 50 μm to 500 μm can be obtained. The measured conductivity profile is a resultant from residual stresses, cold work, surface roughness and the texture of the material. In addition, first results for strain profiling obtained with industry applicable NDE instrument will be presented.

  4. 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.

  5. 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.

  6. 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...

  7. THE QUALITY CONTROL OF ELECTROLYTIC TANTALUM CAPACITORS BY USING THE STRESS TEST

    Directory of Open Access Journals (Sweden)

    P. L. Kuznetsov

    2015-01-01

    Full Text Available The article discusses the accelerated method of analysis the electrolytic tantalum capacitors quality on the basis of the change equivalent series resistance forecast while conducting the STRESS TEST.

  8. Proficiency testing for conducted immunity with a new round robin test device

    NARCIS (Netherlands)

    Tas, Emrah; Cakir, Soydan; Cetintas, Mustafa; Hamouz, Pavel; Mandaris, Dwi; Isbring, Thomas; Kokalj, Miha; Lopez, Daniel; Lundgren, Urban; Pinter, Borut; Poriz, Martin; Pous, Marc; Pythoud, Frederic; Sen, Osman; Silva, Ferran; Svoboda, Marek; Trincaz, Braise; Zhao, Dongsheng

    2016-01-01

    Last year, a new round robin test device was proposed for inter-laboratory comparisons in conducted immunity testing according to IEC 61000-4-6[1]. The device has recently been successfully evaluated among all EMRP Project partners. The device is able to confirm or to deny the testing capability of

  9. 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.

  10. Aerosol tests conducted at Aberdeen Proving Grounds MD.

    Energy Technology Data Exchange (ETDEWEB)

    Brockmann, John E.; Lucero, Daniel A.; Servantes, Brandon Lee; Hankins, Matthew Granholm

    2012-06-01

    Test data are reported that demonstrate the deposition from a spray dispersion system (Illinois Tool Works inductively charging rotary atomization nozzle) for application of decontamination solution to various surfaces in the passenger cabin of a Boeing 737 aircraft. The decontamination solution (EnviroTru) was tagged with a known concentration of fluorescein permitting determination of both airborne decontaminant concentration and surface deposited decontaminant solution so that the effective deposition rates and surface coverage could be determined and correlated with the amount of material sprayed. Six aerosol dispersion tests were conducted. In each test, aluminum foil deposition coupons were set out throughout the passenger area and the aerosol was dispersed. The aerosol concentration was measured with filter samplers as well as with optical techniques Average aerosol deposition ranged from 3 to 15 grams of decontamination solution per square meter. Some disagreement was observed between various instruments utilizing different measurement principles. These results demonstrate a potentially effective method to disperse decontaminant to interior surfaces of a passenger aircraft.

  11. High Temperature Stress Analysis on 61-pin Test Assembly for Reactor Core Sub-channel Flow Test

    International Nuclear Information System (INIS)

    Lee, Dongwon; Kim, Hyungmo; Lee, Hyeongyeon

    2014-01-01

    In this study, a high temperature heat transfer and stress analysis of a 61-pin test fuel assembly scaled down from the full scale 217-pin sub-assembly was conducted. The reactor core subchannel flow characteristic test will be conducted to evaluate uncertainties in computer codes used for reactor core thermal hydraulic design. Stress analysis for a 61-pin fuel assembly scaled down from Prototype Generation IV Sodium-cooled Fast Reactor was conducted and structural integrity in terms of load controlled stress limits was conducted. In this study, The evaluations on load-controlled stress limits for a 61-pin test fuel assembly to be used for reactor core subchannel flow distribution tests were conducted assuming that the test assembly is installed in a Prototype Generation IV Sodium-cooled fast reactor core. The 61-pin test assembly has the geometric similarity on P/D and H/D with PGSFR and material of fuel assembly is austenitic stainless steel 316L. The stress analysis results showed that 4.05MPa under primary load occurred at mid part of the test assembly and it was shown that the value of 4.05Mpa was far smaller than the code allowable of 127MPa. , it was shown that the stress intensity due to due to primary load is very small. The stress analysis results under primary and secondary loads showed that maximum stress intensity of 84.08MPa occurred at upper flange tangent to outer casing and the value was well within the code allowable of 268.8MPa. Integrity evaluations based on strain limits and creep-fatigue damage are underway according to the elevated design codes

  12. 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.

  13. Experiment data report: Gap Conductance Test Series, Test GC 1-3 postirradiation examination. [BWR

    Energy Technology Data Exchange (ETDEWEB)

    Murdock, B. A.

    1977-09-01

    The results of the postirradiation examination of four boiling water reactor type, zircaloy-clad, UO/sub 2/-fueled rods tested as part of the Thermal Fuels Behavior Program are discussed. These rods were employed in Gap Conductance Test GC 1-3 which was conducted to obtain experimental data from which test rod gap conductance values could be determined by both the steady state integral kdT and the power oscillation methods. The postirradiation examination results provided will aid in interpreting and understanding the experimental data obtained during Test GC 1-3 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 and rod power profiles are discussed. Evidence is presented showing that significant amounts of water had been present in two of the four fuel rods during testing. For the two fuel rods that remained intact during the test, measurements of fuel pellet-to-cladding gap, as well as the surface area of the fuel cracks at several axial locations are presented. A total effective radial gap is calculated and the fuel structure and porosity are analyzed.

  14. 49 CFR 40.231 - What devices are used to conduct alcohol confirmation tests?

    Science.gov (United States)

    2010-10-01

    ... Supplies Used in Alcohol Testing § 40.231 What devices are used to conduct alcohol confirmation tests? (a... section are the only devices you may use to conduct alcohol confirmation tests under this part. Note that... use in confirmation testing in the DOT alcohol testing program. (b) To conduct a confirmation test...

  15. 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.

  16. 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

  17. 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.)

  18. Social stress alters expression of large conductance calcium-activated potassium channel subunits in mouse adrenal medulla and pituitary glands.

    Science.gov (United States)

    Chatterjee, O; Taylor, L A; Ahmed, S; Nagaraj, S; Hall, J J; Finckbeiner, S M; Chan, P S; Suda, N; King, J T; Zeeman, M L; McCobb, D P

    2009-03-01

    Large conductance calcium-activated potassium (BK) channels are very prominently expressed in adrenal chromaffin and many anterior pituitary cells, where they shape intrinsic excitability complexly. Stress- and sex-steroids regulate alternative splicing of Slo-alpha, the pore-forming subunit of BK channels, and chronic behavioural stress has been shown to alter Slo splicing in tree shrew adrenals. In the present study, we focus on mice, measuring the effects of chronic behavioural stress on total mRNA expression of the Slo-alpha gene, two key BK channel beta subunit genes (beta2 and beta4), and the 'STREX' splice variant of Slo-alpha. As a chronic stressor, males of the relatively aggressive SJL strain were housed with a different unfamiliar SJL male every 24 h for 19 days. This 'social-instability' paradigm stressed all individuals, as demonstrated by reduced weight gain and elevated corticosterone levels. Five quantitative reverse transcriptase-polymerase chain assays were performed in parallel, including beta-actin, each calibrated against a dilution series of its corresponding cDNA template. Stress-related changes in BK expression were larger in mice tested at 6 weeks than 9 weeks. In younger animals, Slo-alpha mRNA levels were elevated 44% and 116% in the adrenal medulla and pituitary, respectively, compared to individually-housed controls. beta2 and beta4 mRNAs were elevated 162% and 194% in the pituitary, but slightly reduced in the adrenals of stressed animals. In the pituitary, dominance scores of stressed animals correlated negatively with alpha and beta subunit expression, with more subordinate individuals exhibiting levels that were three- to four-fold higher than controls or dominant individuals. STREX variant representation was lower in the subordinate subset. Thus, the combination of subunits responding to stress differs markedly between adrenal and pituitary glands. These data suggest that early stress will differentially affect neuroendocrine cell

  19. 3-D thermal modelling applied to stress-induced anisotropy of thermal conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Pron, H.; Bissieux, C. [Universite de Reims, Unite de Thermique et Analyse Physique, EA 2061, Laboratoire de Thermophysique (URCA/UTAP/LTP), UFR Sciences, Moulin de la Housse, B.P 1039, 51687 cedex 2, Reims (France)

    2004-12-01

    The present work consists in the development of a three-dimensional model of heat diffusion in orthotropic media, based on numerical Fourier transforms, and taking into account the extent of the source. This model has been applied, together with a Gauss-Newton parameter estimation procedure, to identify the components of the conductivity tensor of a steel bar under uniaxial loading. Few percent variations of the conductivity components have been observed for applied stresses remaining in the elastic domain. (authors)

  20. 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

  1. 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

  2. Current trends and future development in pharmacologic stress testing

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jin Ho; Lee, Jae Tae [Kyungpook National University Medical School, Daegu (Korea, Republic of)

    2005-02-15

    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.

  3. 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.

  4. 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

  5. Engineers conduct key water test for A-3 stand

    Science.gov (United States)

    2009-01-01

    Water cascades from the A-2 Test Stand at Stennis Space Center as engineers challenge the limits of the high-pressure water system as part of the preparation process for the A-3 Test Stand under construction. Jeff Henderson, test director for Stennis' A Complex, led a series of tests Nov. 16-20, flowing water simultaneously on the A-1 and A-2 stands, followed by the A-1 and B-1 stands, to determine if the high-pressure industrial water facility pumps and the existing pipe system can support the needs of the A-3 stand. The stand is being built to test rocket engines that will carry astronauts beyond low-Earth orbit and will need about 300,000 gallons of water per minute when operating, but the Stennis system never had been tested to that level. The recent tests were successful in showing the water facility pumps can operate at that capacity - reaching 318,000 gallons per minute in one instance. However, officials continue to analyze data to determine if the system can provide the necessary pressure at that capacity and if the delivery system piping is adequate. 'We just think if there's a problem, it's better to identify and address it now rather than when A-3 is finished and it has to be dealt with,' Henderson said.

  6. 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...

  7. Composite Overwrapped Pressure Vessels (COPV) Stress Rupture Test

    Science.gov (United States)

    Russell, Richard; Flynn, Howard; Forth, Scott; Greene, Nathanael; Kezian, Michael; Varanauski, Don; Yoder, Tommy; Woodworth, Warren

    2009-01-01

    One of the major concerns for the aging Space Shuttle fleet is the stress rupture life of composite overwrapped pressure vessels (COPVs). Stress rupture life of a COPV has been defined as the minimum time during which the composite maintains structural integrity considering the combined effects of stress levels and time. To assist in the evaluation of the aging COPVs in the Orbiter fleet an analytical reliability model was developed. The actual data used to construct this model was from testing of COPVs constructed of similar, but not exactly same materials and pressure cycles as used on Orbiter vessels. Since no actual Orbiter COPV stress rupture data exists the Space Shuttle Program decided to run a stress rupture test to compare to model predictions. Due to availability of spares, the testing was unfortunately limited to one 40" vessel. The stress rupture test was performed at maximum operating pressure at an elevated temperature to accelerate aging. The test was performed in two phases. The first phase, 130 F, a moderately accelerated test designed to achieve the midpoint of the model predicted point reliability. The more aggressive second phase, performed at 160 F was designed to determine if the test article will exceed the 95% confidence interval of the model. This paper will discuss the results of this test, it's implications and possible follow-on testing.

  8. Time-fractional heat conduction law in a magneto-thermoelastic solid with hydrostatic initial stress

    Directory of Open Access Journals (Sweden)

    Nantu Sarkar

    2017-03-01

    Full Text Available In this paper, the theory of fractional order two-temperature generalized thermoelasticity is used to study the propagation of magneto-thermoelastic disturbances in a homogeneous isotropic perfectly conducting half-space medium due hydrostatic initial stress. Normal mode analysis technique and the method of displacement potentials are used to obtain the analytical solutions of the studied field varables. Arbitrary application is chosen to enable us to get the complete solution. The effect of fractional parameter and hydrostatic initial stress on the variations of the studied field quantities has been investigated graphically.

  9. 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.

  10. 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 ...

  11. 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...

  12. Accelerated Stress Testing of Thin-Film Modules with SnO2:F Transparent Conductors

    Energy Technology Data Exchange (ETDEWEB)

    Osterwald, C. R.; McMahon, T. J.; del Cueto, J. A.; Adelstein, J.; Puett, J.

    2003-05-01

    This paper reviews a testing program conducted at NREL for the past two years that applied voltage, water vapor, and light stresses to thin-film photovoltaic (PV) modules with SnO2:F transparent conducting oxides (TCOs) deposited on soda-lime glass superstrates. Electrochemical corrosion at the glass-TCO interface was observed to result in delamination of the thin-film layers. Experimental testing was directed toward accelerating the corrosion and understanding the nature of the resulting damage.

  13. Standard test method for conducting potentiodynamic polarization resistance measurements

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1997-01-01

    1.1 This test method covers an experimental procedure for polarization resistance measurements which can be used for the calibration of equipment and verification of experimental technique. The test method can provide reproducible corrosion potentials and potentiodynamic polarization resistance measurements. 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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 the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  14. Cold Stress and the Cold Pressor Test

    Science.gov (United States)

    Silverthorn, Dee U.; Michael, Joel

    2013-01-01

    Temperature and other environmental stressors are known to affect blood pressure and heart rate. In this activity, students perform the cold pressor test, demonstrating increased blood pressure during a 1- to 2-min immersion of one hand in ice water. The cold pressor test is used clinically to evaluate autonomic and left ventricular function. This…

  15. 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

  16. Composite Overwrapped Pressure Vessel (COPV) Stress Rupture Testing

    Science.gov (United States)

    Greene, Nathanael J.; Saulsberry, Regor L.; Leifeste, Mark R.; Yoder, Tommy B.; Keddy, Chris P.; Forth, Scott C.; Russell, Rick W.

    2010-01-01

    This paper reports stress rupture testing of Kevlar(TradeMark) composite overwrapped pressure vessels (COPVs) at NASA White Sands Test Facility. This 6-year test program was part of the larger effort to predict and extend the lifetime of flight vessels. Tests were performed to characterize control parameters for stress rupture testing, and vessel life was predicted by statistical modeling. One highly instrumented 102-cm (40-in.) diameter Kevlar(TradeMark) COPV was tested to failure (burst) as a single-point model verification. Significant data were generated that will enhance development of improved NDE methods and predictive modeling techniques, and thus better address stress rupture and other composite durability concerns that affect pressure vessel safety, reliability and mission assurance.

  17. 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...

  18. The antiarrhythmic peptide analog ZP123 prevents atrial conduction slowing during metabolic stress

    DEFF Research Database (Denmark)

    Haugan, Ketil; Olsen, Kristine Boisen; Hartvig, Line

    2005-01-01

    OBJECTIVE: As atrial conduction slowing is important in the pathogenesis of atrial reentry arrhythmias, a drug that increases atrial conduction or prevents atrial conduction slowing could serve to prevent atrial reentry arrhythmias. In this study, we investigated whether the novel stable antiarrh......OBJECTIVE: As atrial conduction slowing is important in the pathogenesis of atrial reentry arrhythmias, a drug that increases atrial conduction or prevents atrial conduction slowing could serve to prevent atrial reentry arrhythmias. In this study, we investigated whether the novel stable...... to a broad panel of 80 different cardiac and noncardiac ion channels and receptors and examined the effect of ZP123 on HERG channel conductance. RESULTS: ZP123 dose-dependently prevented metabolic stress-induced atrial CV slowing at doses ranging from 1 nM to 10 microM. ZP123 did not affect CV during...... physiological conditions nor did it affect dynamic CV restitution. ZP123 had no effect on atrial contractility. ZP123 showed no or low affinity binding to all ion channels and receptors examined. ZP123 had no effects on HERG channel activity in concentrations that affected atrial conduction. The concentration...

  19. The Trier Social Stress Test: Principles and practice

    Directory of Open Access Journals (Sweden)

    Andrew P. Allen

    2017-02-01

    Full Text Available Researchers interested in the neurobiology of the acute stress response in humans require a valid and reliable acute stressor that can be used under experimental conditions. The Trier Social Stress Test (TSST provides such a testing platform. It induces stress by requiring participants to make an interview-style presentation, followed by a surprise mental arithmetic test, in front of an interview panel who do not provide feedback or encouragement. In this review, we outline the methodology of the TSST, and discuss key findings under conditions of health and stress-related disorder. The TSST has unveiled differences in males and females, as well as different age groups, in their neurobiological response to acute stress. The TSST has also deepened our understanding of how genotype may moderate the cognitive neurobiology of acute stress, and exciting new inroads have been made in understanding epigenetic contributions to the biological regulation of the acute stress response using the TSST. A number of innovative adaptations have been developed which allow for the TSST to be used in group settings, with children, in combination with brain imaging, and with virtual committees. Future applications may incorporate the emerging links between the gut microbiome and the stress response. Future research should also maximise use of behavioural data generated by the TSST. Alternative acute stress paradigms may have utility over the TSST in certain situations, such as those that require repeat testing. Nonetheless, we expect that the TSST remains the gold standard for examining the cognitive neurobiology of acute stress in humans.

  20. Modeling Reliability Growth in Accelerated Stress Testing

    Science.gov (United States)

    2013-12-01

    190285075. html . [Accessed October 2012]. [2] R. Gates, "Science and Technology (S&T) Priorities for Fiscal Years 2013-17 Planning," 19 April 2011...John Wiley & Sons Inc., 1982. [100] J. Seo , M. Jung and C. Kim, "Design of accelerated life test sampling plans with a non-constant shape

  1. 49 CFR 40.253 - What are the procedures for conducting an alcohol confirmation test?

    Science.gov (United States)

    2010-10-01

    ... FOR TRANSPORTATION WORKPLACE DRUG AND ALCOHOL TESTING PROGRAMS Alcohol Confirmation Tests § 40.253 What are the procedures for conducting an alcohol confirmation test? As the BAT conducting an alcohol... 49 Transportation 1 2010-10-01 2010-10-01 false What are the procedures for conducting an alcohol...

  2. Exercise testing and stress imaging in valvular heart disease.

    Science.gov (United States)

    Henri, Christine; Piérard, Luc A; Lancellotti, Patrizio; Mongeon, François-Pierre; Pibarot, Philippe; Basmadjian, Arsène J

    2014-09-01

    The role of exercise testing and stress imaging in the management of patients with valvular heart disease (VHD) is reviewed in this article. The American College of Cardiology/American Heart Association and the European Society of Cardiology/European Association of Cardiothoracic Surgery have recently put emphasis on the role of exercise testing to clarify symptom status and the use of stress imaging to assess the dynamic component of valvular abnormalities and unmask subclinical myocardial dysfunction that could be missed at rest. Recent studies have demonstrated the incremental prognostic value of exercise echocardiography for asymptomatic patients with severe aortic stenosis, moderate-severe mitral stenosis, and severe primary mitral regurgitation. In patients with low-flow, low-gradient aortic stenosis, dobutamine stress echocardiography is recommended to differentiate true severe from pseudosevere aortic stenosis. Data on the prognostic value of stress echocardiography in aortic regurgitation and functional mitral regurgitation are less robust. Data are sparse on the use of stress imaging in right-sided VHD, however recent studies using stress cardiovascular magnetic resonance imaging offer some prognostic information. Although the strongest recommendations for surgical treatment continue to be based on symptom status and resting left ventricular repercussions, stress imaging can be useful to optimize risk stratification and timing of surgery in VHD. Randomized clinical trials are required to confirm that clinical decision-making based on stress imaging can lead to improved outcomes. Copyright © 2014 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  3. Conversion of engineering stresses to Cauchy stresses in tensile and compression tests of thermoplastic polymers

    Directory of Open Access Journals (Sweden)

    Schümann Kerstin

    2016-09-01

    Full Text Available Thermoplastic polymers exhibit non-isochoric behaviour during tensile and compression testing as well as particular deformations like local necking (tension or buckling (compression. A method for the determination of Cauchy stresses from tensile and compression tests is presented, that considers the actual deformations of the test specimens. The exact geometry of the specimens in the respective present configuration is determined in photographs, which are taken continuously throughout the test. The engineering stresses at several time points are converted into Cauchy stresses using newly developed formulas in consideration of the actual specimen geometry. For validation finite element analyses of the tensile and compression tests are performed using the identified stress-strain curves. The numerical results show good agreement with the experiments for the tested polymers. Thus a method for conversion of engineering to Cauchy stresses in tensile and compression tests could be established considering the non-isochoric deformation in plasticity. With this method “true” stress-strain curves as input for finite element material models can be identified for arbitrary materials.

  4. 10 CFR 26.95 - Conducting an initial test for alcohol using a breath specimen.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Conducting an initial test for alcohol using a breath... Specimens for Testing § 26.95 Conducting an initial test for alcohol using a breath specimen. (a) The collector shall perform the initial breath test as soon as practical after the donor indicates that he or...

  5. 49 CFR 40.229 - What devices are used to conduct alcohol screening tests?

    Science.gov (United States)

    2010-10-01

    ... Alcohol Testing § 40.229 What devices are used to conduct alcohol screening tests? EBTs and ASDs on the... are allowed to use to conduct alcohol screening tests under this part. You may use an ASD that is on the NHTSA CPL for DOT alcohol tests only if there are instructions for its use in this part. An ASD...

  6. Differential susceptibility or diathesis stress? Testing longitudinal associations among parenting, temperament and children’s problem behavior

    NARCIS (Netherlands)

    Stoltz, S.E.M.J.; Beijers, R.; Smeekens, Sanny; Dekovic, M.

    2017-01-01

    In this study we investigated longitudinal associations among parenting, children's temperamental negative affectivity, and internalizing and externalizing behavior. Second, we tested whether findings confirmed the diathesis-stress model or differential susceptibility theory when conducting

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 78 FR 65583 - Capital Planning and Stress Testing

    Science.gov (United States)

    2013-11-01

    ... providers); (4) Describe the frequency with which capital analyses will be conducted; (5) State how capital... NATIONAL CREDIT UNION ADMINISTRATION 12 CFR Part 702 RIN 3133-AE27 Capital Planning and Stress... maintain capital plans. DATES: Comments must be received on or before December 31, 2013. ADDRESSES: You may...

  13. 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.

  14. 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.

  15. 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...

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. Cardiovascular outcomes of a positive nuclear stress test but ...

    African Journals Online (AJOL)

    Cardiovascular outcomes of a positive nuclear stress test but negative coronary angiography in a multiethnic male predominant cohort. ... The occurrence of adverse cardiovascular outcomes (chest pain, congestive heart failure, acute myocardial infarction and stroke) postindex coronary angiogram was tracked. Similar data ...

  2. 12 CFR 652.40 - Stress tests for mortgage securities.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Stress tests for mortgage securities. 652.40 Section 652.40 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM FEDERAL AGRICULTURAL... risk policies. The methodology that you use to analyze mortgage securities must be appropriate for the...

  3. 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.

  4. 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)

  5. Heart-Kidney Biomarkers in Patients Undergoing Cardiac Stress Testing

    Directory of Open Access Journals (Sweden)

    Mikko Haapio

    2011-01-01

    Full Text Available We examined association of inducible myocardial perfusion defects with cardiorenal biomarkers, and of diminished left ventricular ejection fraction (LVEF with kidney injury marker plasma neutrophil gelatinase-associated lipocalin (NGAL. Patients undergoing nuclear myocardial perfusion stress imaging were divided into 2 groups. Biomarkers were analyzed pre- and poststress testing. Compared to the patients in the low ischemia group (n=16, the patients in the high ischemia group (n=18 demonstrated a significantly greater rise in cardiac biomarkers plasma BNP, NT-proBNP and cTnI. Subjects were also categorized based on pre- or poststress test detectable plasma NGAL. With stress, the group with no detectable NGAL had a segmental defect score 4.2 compared to 8.2 (P=.06 in the detectable NGAL group, and 0.9 vs. 3.8 (P=.03 at rest. BNP rose with stress to a greater degree in patients with detectable NGAL (10.2 vs. 3.5 pg/mL, P=.03. LVEF at rest and with stress was significantly lower in the detectable NGAL group; 55.8 versus 65.0 (P=.03 and 55.1 vs. 63.8 (P=.04, respectively. Myocardial perfusion defects associate with biomarkers of cardiac stress, and detectable plasma NGAL with significantly lower LVEF, suggesting a specific heart-kidney link.

  6. 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.

  7. 40 CFR 63.5719 - How do I conduct a performance test?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true How do I conduct a performance test? 63... Operations Controlled by Add-on Control Devices § 63.5719 How do I conduct a performance test? (a) You must... by mass spectrometry, an additional system continuing calibration check after each run, as detailed...

  8. 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...

  9. 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

  10. 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 "spontaneous" breakage of the glass in building elements at ambient temperatures months or years later. According to industry standards, the duration of the tests typically differs between 1 h and 4 h at temperatures of 290 ± 10 °C. Although this temperature is well below the transformation temperature...... 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...

  11. 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

  12. 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

  13. Simulation of Mechanical Stress on Stainless Steel for Pb-Bi Corrosion Test by Using ABAQUS

    Science.gov (United States)

    Irwanto, D.; Mustari, A. P. A.; Budiman, B. A.

    2017-03-01

    Pb-Bi eutectic with its advantageous is proposed to be utilized as a coolant in the GEN IV type of rSeactor. However, high temperature corrosion when contact with stainless steels is one of the issues of Pb-Bi eutectic utilization. It is known that in the environment of high temperature Pb-Bi, mechanical strength of stainless steel may decrease. Thus, simulation of mechanical stress working on stainless steel during in-situ bending test by using ABAQUS was conducted. Several bending degrees were simulated at high temperature to obtain the mechanical stress information. Temperature condition was strongly affect the stress vs. displacement profile. The reported mechanical strength reduction percentage was used to draw predicted mechanical stress under high temperature Pb-Bi environment.

  14. Development of a standardized battery of performance tests for the assessment of noise stress effects

    Science.gov (United States)

    Theologus, G. C.; Wheaton, G. R.; Mirabella, A.; Brahlek, R. E.

    1973-01-01

    A set of 36 relatively independent categories of human performance were identified. These categories encompass human performance in the cognitive, perceptual, and psychomotor areas, and include diagnostic measures and sensitive performance metrics. Then a prototype standardized test battery was constructed, and research was conducted to obtain information on the sensitivity of the tests to stress, the sensitivity of selected categories of performance degradation, the time course of stress effects on each of the selected tests, and the learning curves associated with each test. A research project utilizing a three factor partially repeated analysis of covariance design was conducted in which 60 male subjects were exposed to variations in noise level and quality during performance testing. Effects of randomly intermittent noise on performance of the reaction time tests were observed, but most of the other performance tests showed consistent stability. The results of 14 analyses of covariance of the data taken from the performance of the 60 subjects on the prototype standardized test battery provided information which will enable the final development and test of a standardized test battery and the associated development of differential sensitivity metrics and diagnostic classificatory system.

  15. 300-Area VOC Program Slug Test Characterization Results for Selected Test/Depth Intervals Conducted During the Drilling of Well 399-3-21

    Energy Technology Data Exchange (ETDEWEB)

    Spane, Frank A.

    2007-07-19

    This report presents brief test descriptions and analysis results for multiple, stress-level slug tests that were performed at selected test/depth intervals within well 399-3-21 as part of the 300-Area volatile organic compound characterization program. The test intervals were characterized as the borehole was advanced to its final drill depth (45.7 m) and before its completion as a monitor-well facility. The primary objective of the slug tests was to provide information pertaining to the vertical distribution of hydraulic conductivity with depth at this location and to select the final screen-depth interval for the monitor well. This type of characterization information is important for predicting/simulating contaminant migration (i.e., numerical flow/transport modeling) and designing proper monitor-well strategies within this area.

  16. Pegasus Rocket Wing and PHYSX Glove Undergoes Stress Loads Testing

    Science.gov (United States)

    1997-01-01

    The Pegasus Hypersonic Experiment (PHYSX) Project's Pegasus rocket wing with attached PHYSX glove rests after load-tests at Scaled Composites, Inc., in Mojave, California, in January 1997. Technicians slowly filled water bags beneath the wing, to create the pressure, or 'wing-loading,' required to determine whether the wing could withstand its design limit for stress. The wing sits in a wooden triangular frame which serves as the test-rig, mounted to the floor atop the waterbags. Pegasus is an air-launched space booster produced by Orbital Sciences Corporation and Hercules Aerospace Company (initially; later, Alliant Tech Systems) to provide small satellite users with a cost-effective, flexible, and reliable method for placing payloads into low earth orbit. Pegasus has been used to launch a number of satellites and the PHYSX experiment. That experiment consisted of a smooth glove installed on the first-stage delta wing of the Pegasus. The glove was used to gather data at speeds of up to Mach 8 and at altitudes approaching 200,000 feet. The flight took place on October 22, 1998. The PHYSX experiment focused on determining where boundary-layer transition occurs on the glove and on identifying the flow mechanism causing transition over the glove. Data from this flight-research effort included temperature, heat transfer, pressure measurements, airflow, and trajectory reconstruction. Hypersonic flight-research programs are an approach to validate design methods for hypersonic vehicles (those that fly more than five times the speed of sound, or Mach 5). Dryden Flight Research Center, Edwards, California, provided overall management of the glove experiment, glove design, and buildup. Dryden also was responsible for conducting the flight tests. Langley Research Center, Hampton, Virginia, was responsible for the design of the aerodynamic glove as well as development of sensor and instrumentation systems for the glove. Other participating NASA centers included Ames Research

  17. 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)

  18. 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. PMID:25406088

  19. 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.

  20. 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.

  1. 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.

  2. Standard test method for conducting erosion tests by solid particle impingement using gas jets

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This test method covers the determination of material loss by gas-entrained solid particle impingement erosion with jetnozzle type erosion equipment. This test method may be used in the laboratory to measure the solid particle erosion of different materials and has been used as a screening test for ranking solid particle erosion rates of materials in simulated service environments (1,2 ). Actual erosion service involves particle sizes, velocities, attack angles, environments, and so forth, that will vary over a wide range (3-5). Hence, any single laboratory test may not be sufficient to evaluate expected service performance. This test method describes one well characterized procedure for solid particle impingement erosion measurement for which interlaboratory test results are available. 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 determi...

  3. 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

  4. 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

  5. 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.)

  6. 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.

  7. Stress Free Temperature Testing and Residual Stress Calculations on Out-of-Autoclave Composites

    Science.gov (United States)

    Cox, Sarah; Tate, LaNetra C.; Danley, Susan; Sampson, Jeff; Taylor, Brian; Miller, Sandi

    2012-01-01

    Future launch vehicles will require the incorporation large composite parts that will make up primary and secondary components of the vehicle. NASA has explored the feasibility of manufacturing these large components using Out-of-Autoclave impregnated carbon fiber composite systems through many composites development projects. Most recently, the Composites for Exploration Project has been looking at the development of a 10 meter diameter fairing structure, similar in size to what will be required for a heavy launch vehicle. The development of new material systems requires the investigation of the material properties and the stress in the parts. Residual stress is an important factor to incorporate when modeling the stresses that a part is undergoing. Testing was performed to verify the stress free temperature with two-ply asymmetric panels. A comparison was done between three newly developed out of autoclave IM7 /Bismalieimide (BMI) systems. This paper presents the testing results and the analysis performed to determine the residual stress of the materials.

  8. 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.

  9. Direct Shear Tests of Sandstone Under Constant Normal Tensile Stress Condition Using a Simple Auxiliary Device

    Science.gov (United States)

    Cen, Duofeng; Huang, Da

    2017-06-01

    Tension-shear failure is a typical failure mode in the rock masses in unloading zones induced by excavation or river incision, etc., such as in excavation-disturbed zone of deep underground caverns and superficial rocks of high steep slopes. However, almost all the current shear failure criteria for rock are usually derived on the basis of compression-shear failure. This paper proposes a simple device for use with a servo-controlled compression-shear testing machine to conduct the tension-shear tests of cuboid rock specimens, to test the direct shear behavior of sandstone under different constant normal tensile stress conditions ( σ = -1, -1.5, -2, -2.5 and -3 MPa) as well as the uniaxial tension behavior. Generally, the fracture surface roughness decreases and the proportion of comminution areas in fracture surface increases as the change of stress state from tension to tension-shear and to compression-shear. Stepped fracture is a primary fracture pattern in the tension-shear tests. The shear stiffness, shear deformation and normal deformation (except the normal deformation for σ = -1 MPa) decrease during shearing, while the total normal deformation containing the pre-shearing portion increases as the normal tensile stress level (| σ|) goes up. Shear strength is more sensitive to the normal tensile stress than to the normal compressive stress, and the power function failure criterion (or Mohr envelope form of Hoek-Brown criterion) is examined to be the optimal criterion for the tested sandstone in the full region of tested normal stress in this study.

  10. 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.

  11. 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

  12. Standard test methods for conducting time-for-rupture notch tension tests of materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 These test methods cover the determination of the time for rupture of notched specimens under conditions of constant load and temperature. These test methods also includes the essential requirements for testing equipment. 1.2 The values stated in inch-pound units are to be regarded as the standard. The units 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.

  13. Terahertz NDE of Stressed Composite Overwrapped Pressure Vessels - Initial Testing

    Science.gov (United States)

    Madaras, Eric I.; Seebo, Jeffrey P.; Anatasi, Robert F.

    2009-01-01

    Terahertz radiation nondestructive evaluation was applied to a set of Kevlar composite overwrapped pressure vessel bottles that had undergone a series of thermal and pressure tests to simulate stress rupture effects. The bottles in these nondestructive evaluation tests were bottles that had not ruptured but had survived various times at the elevated load and temperature levels. Some of the bottles showed evidence of minor composite failures. The terahertz radiation did detect visible surface flaws, but did not detect any internal chemical or material degradation of the thin overwraps.

  14. A test of stress theory: relief workers in refugee camps.

    Science.gov (United States)

    Soliman, Hussein H; Gillespie, David F

    2011-10-01

    The purpose of this paper is to apply a stress model drawn from the literature to the relief and social service workers who have been active in refugee camps for a prolonged period of time. Working in difficult environments, social service workers deliver essential services to refugee populations around the world. A model of four work-stress determinants--tasks, management, appreciation and collaboration--was tested on 274 social workers in five regions of the Middle East (Jordan, Lebanon and Syria, as well as the occupied Palestinian territories of the Gaza Strip and the West Bank). Statistical fit indices were adequate but two relationships were statistically insignificant. The collaboration variable was dropped to create a modified model with tasks indirectly and management and appreciation directly affecting work-related stress. The five direct relationships and two indirect relationships of this modified model are consistent with stress theory, and all relationships--direct and indirect--are statistically significant. © 2011 The Author(s). Disasters © Overseas Development Institute, 2011.

  15. 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

  16. 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.

  17. 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... Laboratories (NVSL); (2) The use of proteinase-resistant protein analysis methods including but not limited to...

  18. 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 250.1152 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Requirements Well Tests and Surveys § 250.1152 How do I conduct well...

  19. 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. 

  20. 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

  1. Effect of Acupressure on Non-stress Test (NST Results: A Randomized-Controlled Trial Study

    Directory of Open Access Journals (Sweden)

    Masoume Pirhadi

    2015-10-01

    Full Text Available BackgroundPregnancy and delivery are among the most stressful events in women’s life . Breech presentation is defined as a fetus in a longitudinal lie with the buttocks or feet closest to the cervix. This occurs in 3-4% of all deliveries.The risk for perinatal mortality was 1 in 300 for planned breech deliveries.Some conventional non-surgical therapies for breech presentation are available. acupoint (BL67 stimulations are commonly used for the correction of breech presentation. The present study aimed to evaluate the effect of acupressure on fetal wellbeing test results.MethodThis study is a clinical trialthat was conducted in one group and the two-steps.Participantswere pregnant women (primigravida who were 35 to 18 years that refer to Shahid Beheshti hospital in Isfahan in 2013 to receive routine prenatal care.The 32 pregnant women (32-36 weeks were randomly selected.They were stimulated immediately after the first Non stress test and before the second test.The researchers’ evaluated and analyzed variables using SPSS software version 20.FindingsMean (SD age of the subjects was 24/7±2/8 and 93/8% of them was housekeeper. The frequency of reactive Non Stress Test (NST was same before and after stimulation. The mean time of the tests’ result was decreased after stimulation significantly ( p-value=0.048. ConclusionsAlthough fetal non-stress test result wasn’t influenced by acupressure but this intervention led to shorter testing time to achieve results. In other words, after the intervention, the time it takes to reach a reactive fetal non-stress test is about 2/7 minutes less than the time without intervention.

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

    Directory of Open Access Journals (Sweden)

    Nilson Matheus Mattioni

    2015-02-01

    Full Text Available 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, BMX Turbo RR, and Nidera 7321 RG were used. Seed quality was assessed through the mass of 1,000 seeds (MTS, moisture content (MC, germination test (G, bulk electrical conductivity (BEC, individual electrical conductivity (IEC, accelerated ageing (AA, and field seedling emergence (FSE. To determine a partition point in the IEC test for predicting germination, seeds were subjected to the germination test in the same position used for the IEC test. The accuracy of the partition point was tested by comparing predicted germination with the standard germination test. The partition point obtained for normal seeds was 130 ?S .cm-1.seed-1. The IEC test, however, had limitations in predicting soybean seed germination. The data for predicted germination were different from those obtained by the standard test, because the characteristics of each lot led to differences in the electrical conductivity values.

  3. 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.

  4. 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

  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. 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

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. Minority stress in people who identify as transgender: testing the minority stress model

    OpenAIRE

    Stennett, Sabrina

    2016-01-01

    Objectives: People who identify as transgender are reported to experience high levels of mental health problems in comparison to people who do not identify as transgender. The minority stress model has been used to explain these high prevalence rates. But this model was designed to be used in lesbian, gay and bisexual (LGB) populations (Meyer, 1995, 2003). Researchers have applied some of the hypothesised processes of the model to people who identify as transgender. However, evidence testing ...

  12. "Vernonia v. Acton": Should Schools Conduct Random Drug Tests of Student Athletes?

    Science.gov (United States)

    Mahon, J. Patrick

    1995-01-01

    In June 1995, the U.S. Supreme Court upheld the Vernonia (Oregon) School District's right to conduct random drug tests of its student athletes. The court balanced a seventh grader's privacy interest with the state's interest in curbing drug abuse among student athletes. Before adopting drug-testing policies, school boards should assess the local…

  13. 40 CFR 63.5850 - How do I conduct performance tests, performance evaluations, and design evaluations?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true How do I conduct performance tests...: Reinforced Plastic Composites Production Testing and Initial Compliance Requirements § 63.5850 How do I... by mass spectrometry, an additional system continuing calibration check after each run, as detailed...

  14. 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... 40 Protection of Environment 31 2010-07-01 2010-07-01 true Submission of study plans and conduct of testing. 790.62 Section 790.62 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY...

  15. 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? 250.1151 Section 250.1151 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Production Requirements Well Tests and Surveys § 250.1151 How...

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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)

  1. Soil precompression stress: II a comparison of different compaction tests and stress-displacement behaviour of the soil during wheeling

    NARCIS (Netherlands)

    Keller, T.; Arvidsson, J.; Dawidowski, J.B.; Koolen, A.J.

    2004-01-01

    Precompression stress is often used as a criterion for soil susceptibility to compaction. The objective of this study was to compare precompression stresses derived from different compression test methods and relate these values to measured stress and displacement during wheeling in the field.

  2. 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)

  3. Standard practice for conducting force controlled constant amplitude axial fatigue tests of metallic materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This practice covers the procedure for the performance of axial force controlled fatigue tests to obtain the fatigue strength of metallic materials in the fatigue regime where the strains are predominately elastic, both upon initial loading and throughout the test. This practice is limited to the fatigue testing of axial unnotched and notched specimens subjected to a constant amplitude, periodic forcing function in air at room temperature. This practice is not intended for application in axial fatigue tests of components or parts. Note 1-The following documents, although not directly referenced in the text, are considered important enough to be listed in this practice: E 739 Practice for Statistical Analysis of Linear or Linearized Stress-Life (S-N) and Strain-Life (-N) Fatigue Data STP 566 Handbook of Fatigue Testing STP 588 Manual on Statistical Planning and Analysis for Fatigue Experiments STP 731 Tables for Estimating Median Fatigue Limits

  4. Results From a Pressure Sensitive Paint Test Conducted at the National Transonic Facility on Test 197: The Common Research Model

    Science.gov (United States)

    Watkins, A. Neal; Lipford, William E.; Leighty, Bradley D.; Goodman, Kyle Z.; Goad, William K.; Goad, Linda R.

    2011-01-01

    This report will serve to present results of a test of the pressure sensitive paint (PSP) technique on the Common Research Model (CRM). This test was conducted at the National Transonic Facility (NTF) at NASA Langley Research Center. PSP data was collected on several surfaces with the tunnel operating in both cryogenic mode and standard air mode. This report will also outline lessons learned from the test as well as possible approaches to challenges faced in the test that can be applied to later entries.

  5. 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).

  6. 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.

  7. Relationships between stress corrosion cracking tests and utility operating experience

    Energy Technology Data Exchange (ETDEWEB)

    Baum, Allen

    1999-10-22

    Several utility steam generator and stress corrosion cracking databases are synthesized with the view of identifying the crevice chemistry that is most consistent with the plant cracking data. Superheated steam and neutral solution environments are found to be inconsistent with the large variations in the observed SCC between different plants, different support plates within a plant, and different crevice locations. While the eddy current response of laboratory tests performed with caustic chemistries approximates the response of the most extensively affected steam generator tubes, the crack propagation kinetics in these tests differ horn plant experience. The observations suggest that there is a gradual conversion of the environment responsible for most steam generator ODSCC from a concentrated, alkaline-forming solution to a progressively more steam-enriched environment.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Testing the ecological validity of the Trier Social Stress Test: Association with real-life exam stress.

    Science.gov (United States)

    Henze, Gina-Isabelle; Zänkert, Sandra; Urschler, David F; Hiltl, Tanja J; Kudielka, Brigitte M; Pruessner, Jens C; Wüst, Stefan

    2017-01-01

    The Trier Social Stress Test (TSST) is the most widely used laboratory stress protocol in psychoneuroendocrinology. Despite its popularity, surprisingly few attempts have been made to explore the ecological validity of the TSST. In the present study, 31 young healthy subjects (24 females) were exposed to the TSST about 4 weeks before completing an oral exam on a separate day. Salivary cortisol levels increased significantly in response to both stimuli (TSST: F(2.21, 66.33)=5.73, p=0.004; oral exam: F(1.98, 59.28)=4.38, p=0.017) with similar mean response curves and significant correlations between cortisol increases and areas under the response curves (increase: r=0.67; AUC: r=0.56; both p≤0.01). Correspondingly, changes in positive and negative affect did also show significant correlations between conditions (increase: positive affect: r=0.36; negative affect: r=0.50; both: p≤0.05; AUC: positive affect: r=0.81; negative affect: r=0.70; both p≤0.01) while mean time course dynamics were significantly different (positive affect: F(2.55, 76.60)=10.15, p=0.001; negative affect: F(1.56, 46.82)=23.32, p=0.001), indicating that the oral exam had a more pronounced impact on affect than the TSST. Our findings provide new evidence for the view that cortisol as well as subjective stress responses to the TSST are indeed significantly associated with acute stress responses in real life. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. 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 ...

  16. 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.

  17. 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

  18. The effect of thought importance on stress responses: a test of the metacognitive model.

    Science.gov (United States)

    Capobianco, Lora; Morrison, Anthony P; Wells, Adrian

    2018-03-01

    Negative metacognitive beliefs are central determinants of distress in the metacognitive model of psychological vulnerability to stress. The current study tested this assertion in 75 undergraduate students assigned to either experimental (metacognitive belief manipulation) or control (no metacognitive belief manipulation) condition. All participants underwent a fake EEG, where they were told that the EEG would detect negative thoughts. The experimental subjects were informed that if they had a negative thought they may be exposed to a contingent burst of loud noise, while the control condition was told that they may be exposed to a burst of loud noise at random. Participants also underwent the Trier Social Stress Test. The results showed that on physiological measures (skin conductance level) there were no significant differences between groups. However, on self-report measures (positive and negative affect) participants in the experimental condition reported greater levels of negative affect and lower levels of positive affect in response to stress and maintained low positive affect at recovery. The results are consistent with the metacognitive model and suggest that metacognitive beliefs impact on positive and negative affect in reaction to and recovery from stress exposure.

  19. 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.

  20. 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

  1. 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...

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

    NARCIS (Netherlands)

    Lens, F.; Sperry, J.S.; Christmas, M.A.; Rabaey, D.; Jansen, S.

    2011-01-01

    • 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

  3. 40 CFR 63.7515 - When must I conduct subsequent performance tests or fuel analyses?

    Science.gov (United States)

    2010-07-01

    ... monoxide and your boiler or process heater is in any of the limited use subcategories or has a heat input capacity less than 100 MMBtu per hour, you must conduct annual performance tests for carbon monoxide... established according to § 63.7530 and Table 7 to this subpart, as applicable. The reports for all subsequent...

  4. 40 CFR 63.3360 - What performance tests must I conduct?

    Science.gov (United States)

    2010-07-01

    ... monthly liquid-liquid material balance. (c) Organic HAP content. If you determine compliance with the... moisture. (v) The gas volumetric flow rate, dry molecular weight, and stack gas moisture must be determined.... Use the same test method for both the inlet and outlet measurements which must be conducted...

  5. 30 CFR 250.460 - What are the requirements for conducting a well test?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What are the requirements for conducting a well test? 250.460 Section 250.460 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Oil and Gas Drilling Operations Other Drilling Requirements § 250.460...

  6. 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.)

  7. Adaptive Stress Testing of Airborne Collision Avoidance Systems

    Science.gov (United States)

    Lee, Ritchie; Kochenderfer, Mykel J.; Mengshoel, Ole J.; Brat, Guillaume P.; Owen, Michael P.

    2015-01-01

    This paper presents a scalable method to efficiently search for the most likely state trajectory leading to an event given only a simulator of a system. Our approach uses a reinforcement learning formulation and solves it using Monte Carlo Tree Search (MCTS). The approach places very few requirements on the underlying system, requiring only that the simulator provide some basic controls, the ability to evaluate certain conditions, and a mechanism to control the stochasticity in the system. Access to the system state is not required, allowing the method to support systems with hidden state. The method is applied to stress test a prototype aircraft collision avoidance system to identify trajectories that are likely to lead to near mid-air collisions. We present results for both single and multi-threat encounters and discuss their relevance. Compared with direct Monte Carlo search, this MCTS method performs significantly better both in finding events and in maximizing their likelihood.

  8. A climate stress-test of the financial system

    Science.gov (United States)

    Battiston, Stefano; Mandel, Antoine; Monasterolo, Irene; Schütze, Franziska; Visentin, Gabriele

    2017-03-01

    The urgency of estimating the impact of climate risks on the financial system is increasingly recognized among scholars and practitioners. By adopting a network approach to financial dependencies, we look at how climate policy risk might propagate through the financial system. We develop a network-based climate stress-test methodology and apply it to large Euro Area banks in a `green' and a `brown' scenario. We find that direct and indirect exposures to climate-policy-relevant sectors represent a large portion of investors' equity portfolios, especially for investment and pension funds. Additionally, the portion of banks' loan portfolios exposed to these sectors is comparable to banks' capital. Our results suggest that climate policy timing matters. An early and stable policy framework would allow for smooth asset value adjustments and lead to potential net winners and losers. In contrast, a late and abrupt policy framework could have adverse systemic consequences.

  9. Stress corrosion cracking tests for low carbon stainless steels with work hardened layer

    International Nuclear Information System (INIS)

    Nakano, Junichi; Kikuchi, Masahiko; Tsukada, Takashi

    2005-01-01

    To avoid introduction of Cr depletion at grain boundaries by welding process, low carbon stainless steels (SSs) were used in corrosive environment as one of countermeasures for Stress Corrosion Cracking (SCC). Recently, it is reported that SCCs were introduced at portion with work hardened layer although low carbon SSs had been used at core shrouds and primary loop recirculation piping in Boiling Water Reactors. To simulate and examine the phenomenon, mechanical working, metallographic observation, hardness test and SCC tests in chloride solutions were conducted for low carbon SSs. From the results of metallographic observation and hardness test, it was confirmed that slip bands were observed around the surface and hardened layer was introduced by mechanical working. From the results of SCC tests, it was noticed that cracks which introduced from the surface, had grown into the matrix. It is thought that low carbon SSs with work hardened layer have susceptibility to SCC from the above. (author)

  10. Temperature changes during exercise stress testing in children with burns.

    Science.gov (United States)

    Mlcak, R P; Desai, M H; Robinson, E; McCauley, R L; Robson, M C; Herndon, D N

    1993-01-01

    It has been postulated that because of the extensive destruction of the skin and appendages after thermal injury, the thermoregulatory control mechanism would be impaired, and these patients would be intolerant to prolonged work. Preview studies demonstrate evidence that during work in a hot climate, patients with an extensively healed burn react with an excessive rise in body temperature. This study was designed to investigate the thermoregulatory response to exercise in pediatric patients with burns and to study changes in body temperature during exercise testing. Cardiopulmonary stress tests were completed in 32 children with a mean postburn time of 2.3 +/- 1.5 years and a mean burn size of 44% +/- 23% total body surface area. Exercise variables included expired volume, tidal volume, respiratory rate, tidal/dead space rate, heart rate, and work stage achieved. Temperature monitoring included external auditory canal temperature, burn scar, and normal skin temperature. Values were measured at baseline during and at maximum exercise. Our data indicate all patients reached the same endurance level regardless of the size of the total body surface area burn. Additionally, in a temperature-controlled environment, adequate heat dissipation in children with burns can be maintained during exercise testing without an excessive rise in body temperature.

  11. Product consistency test round robin conducted by the Materials Characterization Center - Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Piepel, G.F.; Jones, T.E.; Eggett, D.L.; Mellinger, G.B.

    1989-09-01

    The Savannah River Laboratory (SRL) Product Consistency Test (PCT) was developed as a short duration leach test that could be used to evaluate the consistency of Defense Waste Processing Facility (DWPF) glass. The goals were to develop a test that would be sensitive to glass composition and homogeneity, rapid enough to support quality control of the production process, and easily conducted remotely to facilitate working with highly radioactive materials. The long-term SRL goal is to show that the PCT can be used to demonstrate that DWPF glass meets the elemental and radionuclide release requirements of the Waste Acceptance Preliminary Specifications (WAPS). The Materials Characterization Center (MCC) at Pacific Northwest Laboratory (PNL) was requested by SRL to conduct a multi-laboratory round robin to evaluate the effectiveness of the PCT methodology. 12 figs., 10 tabs.

  12. Introduction to the Chinese HTR-PM pebble bed equivalent conductivity test facility

    International Nuclear Information System (INIS)

    Liu Zhiyong; Ren Cheng; Sun Yanfei; Yang Xingtuan; Jiang Shengyao

    2014-01-01

    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 under different temperatures are essential parameters for the design of HTR-PM, which are needed to analyze the maximum fuel temperature, temperature distribution and residual heat releasing ability in reactor core. For this purpose, 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 through the pebble bed under vacuum condition and helium environment. The design of HTR-PM pebble bed equivalent conductivity test facility is introduced in detail in this paper. Validation experiments have verified the feasibility of the related materials and structures. Test temperature can be elevated to 1600℃, which covers the whole temperature range of the safety analysis of HTR-PM. (author)

  13. 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.

  14. 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.

  15. Lumped thermal capacitance analysis of transient heat conduction and induced stresses in Ghana Research Reactor vessel

    International Nuclear Information System (INIS)

    Annor-Nyarko, M.; Ayensu Gyeabour, I.; Akaho, E. H. K.

    2013-01-01

    Lumped thermal capacitance analysis has been undertaken to investigate the transient temperature variations, associated induced thermal stress distributions, and the structural integrity of Ghana Research Reactor-I (GHAR R-I) vessel after 15 years of operation. The beltline configuration of the cylindrical vessel of the Miniature Neutron Source Reactor (MNSR) was based on thin-shell and axi-symmetric assumptions with small temperature gradient and low Biot number. The thermal energy transferred by unsteady flow of the coolant to the vessel was determined as internal energy change. Numerical algorithms for Matlab Code were implemented to generate data for transient analysis and simulation. The simulations indicated that the temperature variations and the thermal stresses were below the limits imposed by the vessel material (Aluminium alloy LT 21) specifications of 933 K melting point and allowable yield stress of 480 MPa. The low level of induced thermal stresses indicated that the structural integrity of the reactor vessel has been maintained to forestall any incidence of crack propagation and fatigue failure over the operation period. (au)

  16. 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…

  17. A method for conducting simultaneous convergent tracer tests in multilayered aquifers.

    Science.gov (United States)

    Greswell, Richard B; Durand, Véronique; Aller, Maria F; Riley, Michael S; Tellam, John H

    2014-01-01

    Forced gradient tracer tests between two boreholes can be used to study contaminant transport processes at the small field scale or investigate the transport properties of an aquifer. Full depth tests, in which tracer samples are collected just from the discharge of the abstraction borehole, often give rise to breakthrough curves with multiple peaks that are usually attributed to different flow paths through the aquifer that can rarely be identified from the test results alone. Tests in selected levels of the aquifer, such as those between packer-isolated sections of the boreholes, are time consuming, expensive; and the identification of major transport pathways is not guaranteed. We present a method for simultaneously conducting multiple tracer tests covering the full depth of the boreholes, in which tracer sampling and monitoring is carried out by a novel multilevel sampling system allowing high frequency and cumulative sampling options. The method is applied to a tracer test using fluorescein conducted in the multilayered sandstone aquifer beneath the city of Birmingham, UK, producing six well-defined tracer breakthrough curves. © 2013, National Ground Water Association.

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

    Directory of Open Access Journals (Sweden)

    Qiong Gao

    Full Text Available 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.

  19. 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.

  20. 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.

  1. Predicting saturated hydraulic conductivity from percolation test results in layered silt loam soils.

    Science.gov (United States)

    Jabro, Jay D

    2009-12-01

    The objectives of the study discussed in this article were to develop an empirical relationship between the saturated hydraulic conductivity (Ks) of layered soils and their percolation times (PT) in order to understand the influence of individual layers and compare this with the equations developed by Winneberger (1974) and Fritton, Ratvasky, and Petersen (1986). Field research was conducted on three silt loam soils. Six holes were spaced evenly in two parallel rows of three holes. The Ks was measured at three different layers for each soil using a constant head well permeameter. After completion of the second Ks measurement, the percolation test was conducted. Three linear equations for the upper, middle, and lower layers were developed between the Ks values of each individual layer in all three sites and the corresponding PT. Significant differences were found between the author's results and those predicted by Winneberger (1974) and Fritton and co-authors (1986).

  2. 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...

  3. 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.

  4. Mild Salt Stress Conditions Induce Different Responses in Root Hydraulic Conductivity of Phaseolus vulgaris Over-Time

    Science.gov (United States)

    Calvo-Polanco, Monica; Sánchez-Romera, Beatriz; Aroca, Ricardo

    2014-01-01

    Plants respond to salinity by altering their physiological parameters in order to maintain their water balance. The reduction in root hydraulic conductivity is one of the first responses of plants to the presence of salt in order to minimize water stress. Although its regulation has been commonly attributed to aquaporins activity, osmotic adjustment and the toxic effect of Na+ and Cl− have also a main role in the whole process. We studied the effects of 30 mM NaCl on Phaseolus vulgaris plants after 9 days and found different responses in root hydraulic conductivity over-time. An initial and final reduction of root hydraulic conductivity, stomatal conductance, and leaf water potential in response to NaCl was attributed to an initial osmotic shock after 1 day of treatment, and to the initial symptoms of salt accumulation within the plant tissues after 9 days of treatment. After 6 days of NaCl treatment, the increase in root hydraulic conductivity to the levels of control plants was accompanied by an increase in root fructose content, and with the intracellular localization of root plasma membrane aquaporins (PIP) to cortex cells close to the epidermis and to cells surrounding xylem vessels. Thus, the different responses of bean plants to mild salt stress over time may be connected with root fructose accumulation, and intracellular localization of PIP aquaporins. PMID:24595059

  5. 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 .

  6. Thermal conductivity distributed from a Thermal Response Test (TRT in a borehole heat exchanger (BHE

    Directory of Open Access Journals (Sweden)

    A. Blasi

    2012-12-01

    Full Text Available The Thermal Response Test (TRT is the most versatile tool to determine the thermal propriety of the underground for designing and sizing of the borehole heat exchangers (BHE. The TRT permits to get the average thermal conductivity (λ across the whole stratigraphy, the thermal resistance (Rb of the borehole / grout / rocks and the undisturbed temperature of the soil (Tg. The ground temperature is influenced by climate, topographical, geological and hydrological factors. Vertical temperature changes allows to get the relationships with the lithology and especially with the groundwater. Vertical temperature log, acquired during and after the TRT, permits to calculate the distributed thermal conductivity over each stratigraphic interval. This method permits to verify how the different lithologies and the groundwater contribute to the heat exchange in the borehole/ground system, so called geoexchange. The experimental site test indicates that the marls and clayed-marls levels show a higher thermal inertia than the sandstone ones and then lower values of thermal conducivity. The sandstones have a higher thermal conductivity with a rapid cooling and they provide the main contribution to the ground heat exchange. The distributed thermal conductivity is an useful tool for designing the BHE with the best performance, a better economic return and with low environmental impacts.

  7. The physiological response to Trier Social Stress Test relates to subjective measures of stress during but not before or after the test.

    Science.gov (United States)

    Hellhammer, Juliane; Schubert, Melanie

    2012-01-01

    The Trier Social Stress Test (TSST) is an effective psychosocial laboratory protocol for inducing stress in humans and has been used in numerous research studies. The stressor leads to a physiological response of the hypothalamus-pituitary-adrenal axis (HPAA) and the autonomous nervous system (ANS). Common biomarkers are cortisol levels and heart rate. In addition to the physiological stress response, the TSST also triggers a psychological response such as an increase in perceived stress, anxiety and emotional insecurity. Whereas HPA and ANS measures can easily be obtained for the TSST period itself, psychological measures are usually determined prior to (baseline) and after the TSST. This may exclude information of the stressful event itself. In the present study, we assessed perceived stress, anxiety and emotional insecurity before, during and after the TSST using visual analogue scales. In addition, cortisol levels and heart rates were assessed. Data of 260 healthy non-smoking males aged 16-60 yrs were used for analyses. Our results show that stress perception, anxiety and emotional insecurity were significantly higher during the TSST as compared to post-TSST ratings. Furthermore, our results suggest a covariance of the psychological stress response during the TSST and the physiological stress responses (cortisol and heart rate) for stress perception though the explained variance was small. This observation was not found for pre- and post-TSST ratings suggesting that assessing psychological stress measures during the stressor itself present a more informative measure of the stress response. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. 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.

  9. Seasonal stress drives predictable changes in inbreeding depression in field-tested captive populations of Drosophila melanogaster.

    Science.gov (United States)

    Enders, Laramy S; Nunney, Leonard

    2012-09-22

    Recent meta-analyses conducted across a broad range of taxa have demonstrated a strong linear relationship between the change in magnitude of inbreeding depression under stress and stress level, measured as fitness loss in outbred individuals. This suggests that a general underlying response may link stress and inbreeding depression. However, this relationship is based primarily on laboratory data, and it is unknown whether natural environments with multiple stressors and fluctuating stress levels alter how stress affects inbreeding depression. To test whether the same pattern persists in the field, we investigated the effect of seasonal variation on stress level and inbreeding depression in a 3-year field study measuring the productivity of captive populations of inbred and outbred Drosophila melanogaster. We found cold winter temperatures were most stressful and induced the greatest inbreeding depression. Furthermore, these data, collected under natural field conditions, conformed to the same predictive linear relationship seen in Drosophila laboratory studies, with inbreeding depression increasing by 0.17 lethal equivalents for every 10 per cent increase in stress level. Our results suggest that under natural conditions stress level is a primary determinant of the magnitude of inbreeding depression and should be considered when assessing extinction vulnerability in small populations.

  10. Cost-effectiveness of exercise stress testing performed as part of executive health examinations.

    Science.gov (United States)

    Shah, S J; Rehman, A; Shaukat, M H S; Awais, M

    2017-05-01

    An executive health examination is offered at many hospitals for "busy executives" that comprises of a typical history and examination along with screening tests for major cardiovascular and respiratory illnesses. Exercise stress tests are also frequently included in such packages, though the appropriateness of such stress testing remains uncertain. To assess the appropriateness and cost-effectiveness of exercise stress tests performed as part of executive health examinations. Records of all individuals who underwent an executive health examination at our institution between January, 2007 and December, 2012 were retrospectively reviewed. Data were collected pertaining to demographics, cardiovascular risk factors, indication of stress testing and results of exercise stress tests. Of a total of 1650 subjects who underwent exercise stress tests as part of executive health examinations, indication for exercise stress testing was class IIb or III (as per American College of Cardiology's appropriateness criteria) in 96.1 % of subjects. The cumulative cost and time burden of testing for these subjects were Rs. 11,419,200/- PKR (≈$114,192 USD) and 2 weeks and 4 days, respectively. Exercise stress tests were not positive for ischemia in any such cases. Based on the results of this study, exercise stress tests should not be routinely offered as part of executive health examinations.

  11. 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...

  12. Simulated Service and Stress Corrosion Cracking Testing for Friction Stir Welded Spun Form Domes

    Science.gov (United States)

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

    2010-01-01

    -point loaded specimens under alternate immersion conditions in a 3.5% NaCl environment for 90 days. In addition, experiments were conducted to determine the threshold stress intensity factor for SCC (K1SCC) of Al-Li 2195 which to our knowledge has not been determined previously. The successful simulated service and stress corrosion testing helped to provide confidence to continue to Ares 1 scale dome fabrication.

  13. Dependence of Hydraulic Conductivity on Test Scale: Artifact or Something More?

    Science.gov (United States)

    Butler, J. J., Jr.

    2014-12-01

    Over the years, there have been frequent reports of a dependence of hydraulic conductivity (K) estimates on test volume (scale). This dependence is commonly demonstrated using results from laboratory permeameter tests and from slug and pumping tests. Typically, K estimates from pumping tests are reported to be considerably larger than those from slug tests, which, in turn, are considerably larger than those from permeameter tests. Despite the large body of evidence, a key question remains unresolved - is this relationship produced by methodological differences or a natural underlying scale dependence in K? The most effective means to resolve this question is to use a single technique that can be configured to span orders of magnitude in test scale. The constant-rate pumping test is just such a technique. In the first few minutes to tens of minutes of pumping, the affected volume is relatively small. In contrast, after days of pumping, this volume can be orders of magnitude larger. If there is an underlying scale dependence, it should be revealed by K estimates determined from different durations of pumping. We have been investigating this issue using pumping tests in unconsolidated aquifers in central and western Kansas. In western Kansas, irrigation wells are pumped nearly continuously for the entire growing season. If nearby observation wells are available, we can use this near-continuous pumping as a long-duration, albeit imperfectly controlled, pumping test to increase the scale of the investigation. An initial assessment of these formal and ad-hoc pumping tests has found no evidence of a scale dependence in K; these tests are typically characterized by homogeneous aquifer behavior at small to moderate times of pumping after which boundary effects become dominant. Thus, if there is an underlying scale dependence, it is below the scale of these observations, which would have to be considered rather serendipitous. We can assess the relationship at smaller scales

  14. 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

  15. 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.

  16. Conduction-only transport phenomena in compressible bivelocity fluids: diffuse interfaces and Korteweg stresses.

    Science.gov (United States)

    Brenner, Howard

    2014-04-01

    "Diffuse interface" theories for single-component fluids—dating back to van der Waals, Korteweg, Cahn-Hilliard, and many others—are currently based upon an ad hoc combination of thermodynamic principles (built largely upon Helmholtz's free-energy potential) and so-called “nonclassical” continuum-thermomechanical principles (built largely upon Newtonian mechanics), with the latter originating with the pioneering work of Dunn and Serrin [Arch. Ration. Mech. Anal. 88, 95 (1985)]. By introducing into the equation governing the transport of energy the notion of an interstitial work-flux contribution, above and beyond the usual Fourier heat-flux contribution, namely, jq = -k∇T, to the energy flux, Dunn and Serrin provided a rational continuum-thermomechanical basis for the presence of Korteweg stresses in the equation governing the transport of linear momentum in compressible fluids. Nevertheless, by their failing to recognize the existence and fundamental need for an independent volume transport equation [Brenner, Physica A 349, 11 (2005)]—especially for the roles played therein by the diffuse volume flux j v and the rate of production of volume πν at a point of the fluid continuum—we argue that diffuse interface theories for fluids stand today as being both ad hoc and incomplete owing to their failure to recognize the need for an independent volume transport equation for the case of compressible fluids. In contrast, we point out that bivelocity hydrodynamics, as it already exists [Brenner, Phys. Rev. E 86, 016307 (2012)], provides a rational, non-ad hoc, and comprehensive theory of diffuse interfaces, not only for single-component fluids, but also for certain classes of crystalline solids [Danielewski and Wierzba, J. Phase Equilib. Diffus. 26, 573 (2005)]. Furthermore, we provide not only what we believe to be the correct constitutive equation for the Korteweg stress in the class of fluids that are constitutively Newtonian in their rheological response

  17. 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.

  18. Effects of conducting media and gender on an electric pulp test.

    Science.gov (United States)

    Chunhacheevachaloke, E; Ajcharanukul, O

    2016-03-01

    (1) To determine the pulpal sensory thresholds in human teeth obtained from using various EPT conducting media and (2) to determine whether there are gender differences. One intact maxillary central incisor was randomly selected from each of 40 participants (20 male, 20 female) aged 19-24 year. A constant-current electrical stimulator (University of Bristol, UK) was used to apply electrical stimuli with different conducting media at intervals of 1 min on the middle of the crown to evaluate the sensory threshold of the tooth. The tip of the electrode was coated with a thin layer of test media. The sensory thresholds and the pain scores were measured simultaneously after applying stimuli twice a second and gradually increasing the intensity until felt by the participants. Test media included water-based gels (K-Y UltraGel; Xylocaine 2% Jelly, electrode gel, fluoride gel) and toothpastes (Colgate Total; Sensodyne Repair & Protect; Dentiste' Plus White; Sparkle White). The sensory threshold data were evaluated using two-way anova followed by the Tukey test. Xylocaine 2% Jelly and fluoride gel evoked significantly lower threshold values when compared with Sensodyne Repair & Protect (P media, the mean sensory threshold from the female group was significantly lower than that of the male group (P media and gender. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  19. 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…

  20. High-Stakes Testing and Its Relationship to Stress Levels of Coastal Secondary Teachers

    Science.gov (United States)

    McDaniel, Sheneatha Lashelle Alexander

    2012-01-01

    The purpose of this research was to examine the relationship between high-stakes tests and stress with secondary teachers. Furthermore, this study investigated whether veteran teachers experience more stress than novice teachers and whether or not self-efficacy, gender, accountability status, and years of experience influence teacher stress as it…

  1. 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.

  2. Understanding the POW experience: stress research and the implementation of the 1955 U.S. Armed Forces Code of Conduct.

    Science.gov (United States)

    Genter, Robert

    2015-01-01

    Facing accusations about weak military discipline following the supposedly poor behavior of American soldiers held captive during the Korean War, President Dwight Eisenhower instituted a Code of Conduct for the Armed Services in 1955. In response, military leaders hired numerous social and behavioral scientists to investigate the nature of the prisoner-of-war (POW) experience. These researchers not only challenged official government accounts of POW activities but opened up a new field of study-stress research. They also changed military training policy, which soon focused more on stress inoculation training, and, in so doing, helped lead the shift in psychology away from behaviorism to ego and cognitive psychology. In this sense, my article ties shifts within the social and behavioral sciences in the 1950s to the military history of the early Cold War, a connection generally missing from most accounts of this period. © 2014 Wiley Periodicals, Inc.

  3. 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

  4. Fetal monitor for non-stress-test screening at home.

    Science.gov (United States)

    Horio, H; Murakami, M; Chiba, Y; Inada, H

    1998-01-01

    A fetal monitoring device developed for non-stress-test (NST) screening at home works on battery power, and is so small and lightweight (152 x 120 x 64 mm, 600 g) that a pregnant woman can monitor fetal Doppler ultra-sound and record fetal heart rate (FHR) and uterine contraction (UC) data on an attached memory IC card at any time and in any place away from a hospital. The physician can evaluate these data, transmitted via public telephone lines, using a built-in modem in the monitor. The combination of the memory IC card as a temporary storage device with the intermittent data transmission to the host provides endless data storage. The input-output relationship of the device was quantitatively evaluated using a Doppler ultrasound heart rate simulator. Forty pregnant women participated in an evaluation of this system. The total number of NST data transmissions was 648, and the total amount of data received was more than 6.7 Mbytes. Of the 648 transmissions, 475 were adequate for clinical interpretation. Of the 101 failed NST data transmissions, 85 resulted from patient handling errors. However, 82.4% of these errors resulted in reexamination and transfer of new data by the patients, who were aware of the insufficiency of the original data. The main cause of the noise in the data was zero-count data; this noise rate accounted for 4.1% of the data abnormalities. A questionnaire survey found that 96% of the participants wanted to use the monitor again in their next pregnancies, and 83% would recommend its use to pregnant friends. The system was easily used and accepted by pregnant women, and the NST data obtained were sufficient for clinical interpretation.

  5. Pathophysiological rationale and diagnostic targets for diastolic stress testing.

    Science.gov (United States)

    Erdei, Tamás; Aakhus, Svend; Marino, Paolo; Paulus, Walter J; Smiseth, Otto A; Fraser, Alan G

    2015-09-01

    Cardiopulmonary functional reserve measured as peak oxygen uptake is predicted better at rest by measures of cardiac diastolic function than by systolic function. Normal adaptations in the trained heart include resting bradycardia, increased LV end-diastolic volume and augmented early diastolic suction on exercise. In normal populations early diastolic relaxation declines with age and end-diastolic stiffness increases, but in healthy older subjects who have exercised throughout their lives diastolic function can be well preserved. The mechanisms by which LV diastolic filling and pressures can be impaired during exercise include reduced early diastolic recoil and suction (which can be exacerbated by increased late systolic loading), increased preload and reduced compliance. Abnormal ventricular-arterial coupling and enhanced ventricular interaction may contribute in particular circumstances. One common final pathway that causes breathlessness is an increase in LV filling pressure and left atrial pressure. Testing elderly subjects with breathlessness of unknown aetiology in order to detect worsening diastolic function during stress is proposed to diagnose heart failure with preserved EF. In invasive studies, the most prominent abnormality is an early and rapid rise in pulmonary capillary wedge pressure. A systematic non-invasive diagnostic strategy would use validated methods to assess different mechanisms of inducible diastolic dysfunction and not just single parameters that offer imprecise estimates of mean LV filling pressure. Protocols should assess early diastolic relaxation and filling as well as late diastolic filling and compliance, as these may be affected separately. Better refined diagnostic targets may translate to more focused treatment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. 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.

  7. Surface preparation for residual stress measurement of an accelerated corrosion tested welded marine steel

    International Nuclear Information System (INIS)

    Ahmad, Bilal; Fitzpatrick, Michael E.

    2015-01-01

    Residual stress measurement is often required for the assessment of structural integrity of components. Measurement of residual stress in corrosion tested specimens is challenging owing to the difficulty of accessing the surface because of the rust layer. This study explored the potential methods for the surface preparation of an ultrasonically-peened and accelerated corrosion tested DH36 marine steel fillet welded specimen to ease the way for subsequent residual stress measurement using neutron diffraction and the contour method. We find that hydroblasting introduces compressive residual stress at the surface that will alter the surface stress to be measured

  8. 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.

  9. 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

  10. 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

  11. 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...

  12. 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......) Assessing the utility of the numerical method by comparison with the Gompertz method; (ii) Comparing the estimated precompression stress to the maximum preload of test samples; (iii) Determining the influence that soil type, bulk density and soil water potential have on the estimated precompression stress...

  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. 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.

  15. Ensemble Kalman filter versus ensemble smoother for assessing hydraulic conductivity via tracer test data assimilation

    Directory of Open Access Journals (Sweden)

    E. Crestani

    2013-04-01

    Full Text Available Estimating the spatial variability of hydraulic conductivity K in natural aquifers is important for predicting the transport of dissolved compounds. Especially in the nonreactive case, the plume evolution is mainly controlled by the heterogeneity of K. At the local scale, the spatial distribution of K can be inferred by combining the Lagrangian formulation of the transport with a Kalman-filter-based technique and assimilating a sequence of time-lapse concentration C measurements, which, for example, can be evaluated on site through the application of a geophysical method. The objective of this work is to compare the ensemble Kalman filter (EnKF and the ensemble smoother (ES capabilities to retrieve the hydraulic conductivity spatial distribution in a groundwater flow and transport modeling framework. The application refers to a two-dimensional synthetic aquifer in which a tracer test is simulated. Moreover, since Kalman-filter-based methods are optimal only if each of the involved variables fit to a Gaussian probability density function (pdf and since this condition may not be met by some of the flow and transport state variables, issues related to the non-Gaussianity of the variables are analyzed and different transformation of the pdfs are considered in order to evaluate their influence on the performance of the methods. The results show that the EnKF reproduces with good accuracy the hydraulic conductivity field, outperforming the ES regardless of the pdf of the concentrations.

  16. Testing the Relationship between Human Occupancy in the Landscape and Tadpole Developmental Stress

    Science.gov (United States)

    Eterovick, Paula C.; Bar, Luís F. F.; Souza, Jorge B.; Castro, José F. M.; Leite, Felipe S. F.; Alford, Ross A.

    2015-01-01

    Amphibian population declines are widespread; the main causal factors are human related and include habitat fragmentation due to agriculture, mining, fires, and urban development. Brazil is the richest country in species of amphibians, and the Brazilian regions with the greatest amphibian diversity are experiencing relatively high rates of habitat destruction, but there are presently relatively few reports of amphibian declines. It is thus important to develop research methods that will detect deterioration in population health before severe declines occur. We tested the use of measurements of fluctuating asymmetry (FA) taken on amphibian larvae to detect anthropogenic stress. We hypothesized that greater human occupancy in the landscape might result in more stressful conditions for amphibians. We conducted this study at the Espinhaço mountain range in southeastern Brazil, using as a model an endemic species (Bokermannohyla saxicola, Hylidae). We chose two tadpole denticle rows and eye-nostril distance as traits for FA measurement. We measured percent cover of human-altered habitats in the landscape around tadpole sampling points and measured FA levels in sampled tadpoles. We found FA levels to differ among localities but found no relationship between human modification of the landscape and tadpole FA levels. Levels of FA in the traits we examined may not be strongly affected by environmental conditions, or may be affected by local variables that were not captured by our landscape-scale measures. Alternatively, populations may be genetically differentiated, affecting how FA levels respond to stress and obscuring the effects of anthropogenic disturbance. PMID:25793699

  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. 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.

  19. 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

  20. Learning aptitude, spatial orientation and cognitive flexibility tested in a virtual labyrinth after virtual stress induction.

    Science.gov (United States)

    Delahaye, Marcel; Lemoine, Patrick; Cartwright, Shanique; Deuring, Gunnar; Beck, Johannes; Pflueger, Marlon; Graf, Marc; Hachtel, Henning

    2015-01-01

    Under stressful conditions such as in an emergency situation, efficient information processing is essential for reasonable responses. Virtual Reality (VR) technology is used to induce stress and to test three main cognitive functions for decision making in stressful situations. A VR task was developed to induce stress following the Trier Social Stress Test (TSST) protocol and two VR cognitive performance tests to measure learning aptitude, spatial orientation and cognitive flexibility. Participants (N = 31) gave a public speech in front of a virtual audience (TSST) and later had to find their way out of different VR labyrinths. The first exercise tested spatial orientation and learning aptitude where participants had to learn aspects of the ground layout and geometric icons had to be identified as correct in order to be able to exit. The second labyrinth tested cognitive flexibility on the background of the Wisconsin Card Sorting Test. Correlations were analyzed using Kendall Tau Correlation (One-tailed tests with p set to 0.05 for all analyses). Heart rate (HR) was calculated from the RR time values and averaged across the TSST- speech and the post-stress period. Autonomic nervous system reactivity was defined as the deviation of HR during TSST- speech condition from post-stress baseline measurement. A repeated-measures t-test was used to analyze differences. The newly developed virtual stress test was successfully adapted from the original TSST. Participants perceived the task as stressful and scored an average of 5.7 points on a 1-8 Likert Scale. As a physiological stress parameter, increased heart rates of the participants showed that they were more stressed during the TSST procedure compared to the post-stress period. Also, the subjective stress perception, has a strong correlation with the results of the cognitive tasks performed after the stress induction. The more a participant experienced the TSST as stressful, the lower their learning aptitude and

  1. 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…

  2. Low mercury concentrations cause oxidative stress and endothelial dysfunction in conductance and resistance arteries.

    Science.gov (United States)

    Wiggers, G A; Peçanha, F M; Briones, A M; Pérez-Girón, J V; Miguel, M; Vassallo, D V; Cachofeiro, V; Alonso, M J; Salaices, M

    2008-09-01

    Increased cardiovascular risk after mercury exposure has been described, but the underlying mechanisms are not well explored. We analyzed the effects of chronic exposure to low mercury concentrations on endothelium-dependent responses in aorta and mesenteric resistance arteries (MRA). Wistar rats were treated with mercury chloride (1st dose 4.6 microg/kg, subsequent dose 0.07 microg.kg(-1).day(-1) im, 30 days) or vehicle. Blood levels at the end of treatment were 7.97 +/- 0.59 ng/ml. Mercury treatment: 1) did not affect systolic blood pressure; 2) increased phenylephrine-induced vasoconstriction; 3) reduced acetylcholine-induced vasodilatation; and 4) reduced in aorta and abolished in MRA the increased phenylephrine responses induced by either endothelium removal or the nitric oxide synthase (NOS) inhibitor N(G)-nitro-l-arginine methyl ester (l-NAME, 100 microM). Superoxide dismutase (SOD, 150 U/ml) and the NADPH oxidase inhibitor apocynin (0.3 mM) decreased the phenylephrine-induced contraction in aorta more in mercury-treated rats than controls. In MRA, SOD did not affect phenylephrine responses; however, when coincubated with l-NAME, the l-NAME effect on phenylephrine response was restored in mercury-treated rats. Both apocynin and SOD restored the impaired acetylcholine-induced vasodilatation in vessels from treated rats. Endothelial NOS expression did not change in aorta but was increased in MRA from mercury-treated rats. Vascular O2(-) production, plasmatic malondialdehyde levels, and total antioxidant status increased with the mercury treatment. In conclusion, chronic exposure to low concentrations of mercury promotes endothelial dysfunction as a result of the decreased NO bioavailability induced by increases in oxidative stress. These findings offer further evidence that mercury, even at low concentrations, is an environmental risk factor for cardiovascular disease.

  3. 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...

  4. 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.

  5. 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.

  6. Dynamic regulation of the root hydraulic conductivity of barley plants in response to salinity/osmotic stress.

    Science.gov (United States)

    Kaneko, Toshiyuki; Horie, Tomoaki; Nakahara, Yoshiki; Tsuji, Nobuya; Shibasaka, Mineo; Katsuhara, Maki

    2015-05-01

    Salinity stress significantly reduces the root hydraulic conductivity (Lpr) of several plant species including barley (Hordeum vulgare). Here we characterized changes in the Lpr of barley plants in response to salinity/osmotic stress in detail using a pressure chamber. Salt-tolerant and intermediate barley cultivars, K305 and Haruna-nijyo, but not a salt-sensitive cultivar, I743, exhibited characteristic time-dependent Lpr changes induced by 100 mM NaCl. An identical response was evoked by isotonic sorbitol, indicating that this phenomenon was triggered by osmotic imbalances. Further examination of this mechanism using barley cv. Haruna-nijyo plants in combination with the use of various inhibitors suggested that various cellular processes such as protein phosphorylation/dephosphorylation and membrane internalization appear to be involved. Interestingly, the three above-mentioned barley cultivars did not exhibit a remarkable difference in root cell sap osmolality under hypertonic conditions, in contrast to the case of Lpr. The possible biological significance of the regulation of Lpr in barley plants upon salinity/osmotic stress is discussed. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Stress and avoidance in Pseudoseizures: testing the assumptions.

    Science.gov (United States)

    Frances, P L; Baker, G A; Appleton, P L

    1999-04-01

    Twenty women and 10 men with Pseudoseizures were matched by age and gender with an epilepsy- and a healthy-control group. In response to clinical and research evidence of a relationship between Pseudoseizures and the experience of stress, it was hypothesised that people with Pseudoseizures would perceive their ongoing lives as more stressful, and use more avoidant and distancing coping, and less problem-focused coping, than people in the two control groups. Using the Perceived Stress Scale (Cohen et al., J. Health Soc. Behav. 24, 1983, 385-396) and the Ways of Coping, revised version (Folkman and Lazarus, Manual for Ways of Coping Questionnaire, Consulting Psychologist Press, Paola Alto, CA, 1988) the study found that people with Pseudoseizures: (1) perceived their ongoing lives as significantly more stressful; (2) were significantly more likely to use a maladaptive (escape-avoidant) coping strategy; and (3) were significantly less likely to use an adaptive (planful problem solving) approach to coping than healthy controls. The study findings indicate that people with Pseudoseizures experience lives as stressful as do people with epilepsy, and are likely to employ maladaptive coping responses. Implications for diagnosis, intervention and future research are discussed.

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

    Science.gov (United States)

    Yan, Xiao-Ling; Dong, Shi-Yun; Xu, Bin-Shi; Cao, Yong

    2018-02-13

    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.

  9. Standard guide for conducting wear tests using a rotary platform, double-head abraser

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This guide covers and is intended to assist in establishing procedures for conducting wear tests of rigid or flexible materials utilizing the rotary platform, double-head abraser (RPDH). 1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.2.1 Exception—English units are used when determining coating thickness. 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.

  10. Stressful point-of-care rapid testing for human immunodeficiency virus, hepatitis C virus, and syphilis.

    Science.gov (United States)

    Reynolds, Grace L; Fisher, Dennis G; Brocato, Jo; van Otterloo, Lucy; Khahlil, Khaloud; Huckabay, Loucine

    2017-09-01

    Even with technological advances in point-of-care rapid testing for HIV, hepatitis, and syphilis, individuals may still find the experience of submitting to testing, and receiving results, to be stressful. Participants completed the rapid test experience questionnaires to assess stress both prior to and after the specimen collection. Participants completed the risk behavior assessment, the coping strategies indicator, and the Barratt impulsivity scale. Participants chose which rapid tests they wanted using a list administered via computer. Logistic regression analysis was used to model self-reported stress prior to testing and after testing. A total of 1097 individuals completed testing. Individuals who scored high on avoidance reported a stressful experience at pretest (OR = 1.15, CI = 1.04, 1.26) while higher educational attainment was associated with no stress at both time points. Injection drug users, avoidant, and impulsive individuals experience stress either before or after rapid testing. Education appears to be protective against stressful testing.

  11. ISOKINETIC TESTING OF ANKLE MUSCULAR STRENGTH AND PROPRIOCEPTION, BALANCE AND NERVE CONDUCTION IN PATIENTS WITH POLYNEUROPATHY

    Directory of Open Access Journals (Sweden)

    Ashraf Darwesh

    2017-12-01

    Full Text Available Background: Polyneuropathy is one of the most common chronic complications associated with diabetes mellitus, it is a damage to the peripheral nerves and manifested by signs and symptoms as numbness, irritation, and pain in the upper and lower limbs. This study aimed to evaluate muscular performance and proprioception at the ankle in diabetic neuropathic patients with quantitative and standardized tools and correlate these findings with those of sural nerve conduction velocity (sural NCV and amplitude. Methods: Fifteen male patients with diabetic neuropathy participated in this study, with age ranged from 40 to 55 years, and fifteen age-matched healthy subjects participated as a control group. Biodex Isokinetic System was used to assess the strength of ankle dorsiflexors and planter flexors and ankle reposition accuracy. Berg balance test was used to assess balance. Sural nerve conduction velocity (NCV and amplitude were examined by diabetic polyneuropathy check (DPN-check device. Results: The results showed a significant decrease in the mean peak torque values of the plantar flexors and dorsiflexors and a significant increase in the reposition error in the diabetic neuropathic group (p=0.0001. The results also revealed a significant decrease in the mean values of the Berg balance scores in diabetic neuropathy group (p=0.0001. Sural NCV and amplitude tests revealed abnormal values (p<0.05. Conclusion: It was concluded that the isokinetic system is an objective and sensitive tool to detect the motor and sensory changes of the diabetic neuropathic patients, also an examination by DPN-check device help in the determination of the severity of the disease. Moreover, it can be concluded that there are strong correlations between duration of diabetes and sural nerve NCV and amplitude and the peak torque of the muscles around the ankle.

  12. 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

  13. Experimental determination of thermal conductivity of soil with a thermal response test

    Directory of Open Access Journals (Sweden)

    Banjac Miloš J.

    2012-01-01

    Full Text Available Optimal design of a borehole heat exchanger, as the outer part of a ground source heat pump heating system, requires information on the thermal properties of the soil. Those data, the effective thermal conductivity of the soil λeff and the average temperature of the soil T0, enable us to determine the necessary number and depth of boreholes. The determination of thermal conductivity of the soil in laboratory experiments does not usually coincide with the data under in-situ conditions. Therefore, an in-situ method of experimental determination of these parameters, the so-called thermal response test, is presented in this paper. In addition to the description of the experimental procedure and installation overview, the paper describes methods based on theory and presents their basic limitations, through the presentation of experimental data. [Acknowledgment. This paper is made in a scope of the project TR 33047 “Intelligent climate control systems to achieve energy efficient regime in the complex conditions of exploitation” funded by the Ministry of Education and Science of the Republic of Serbia.

  14. Evaluation of ability of reference toxicity tests to identify stress in laboratory populations of the amphipod Hyalella azteca

    Science.gov (United States)

    McNulty, E.W.; Dwyer, F.J.; Ellersieck, Mark R.; Greer, E.I.; Ingersoll, C.G.; Rabeni, C.F.

    1999-01-01

    Standard methods for conducting toxicity tests imply that the condition of test organisms can be established using reference toxicity tests. However, only a limited number of studies have evaluated whether reference toxicity tests can actually be used to determine if organisms are in good condition at the start of a test. We evaluated the ability of reference toxicants to identify stress associated with starvation in laboratory populations of the amphipod Hyalella azteca using acute toxicity tests and four reference toxicants: KCl, CdCl2, sodium pentachlorophenate (NaPCP), and carbaryl. Stress associated with severe starvation was observed with exposure of amphipods to carbaryl or NaPCP but not with exposure to KCl or CdCl2 (i.e., lower LC50 with severe starvation). Although the LC50s for NaPCP and carbaryl were statistically different between starved and fed amphipods, this difference may not be biologically significant given the variability expected in acute lethality tests. Stress associated with sieving, heat shock, or cold shock of amphipods before the start of a test was not evident with exposure to carbaryl or KCl as reference toxicants. The chemicals evaluated in this study provided minimal information about the condition of the organisms used to start a toxicity test. Laboratories should periodically perform reference toxicity tests to assess the sensitivity of life stages or strains of test organisms. However, use of other test acceptability criteria required in standard methods such as minimum survival, growth, or reproduction of organisms in the control treatment at the end of a test, provides more useful information about the condition of organisms used to start a test compared to data generated from reference toxicity tests.

  15. Stress measurement using magnetic Barkhausen noise and metal magnetic memory testing

    International Nuclear Information System (INIS)

    Wang, Ping; Zhu, Shougao; Tian, Gui Yun; Wang, Haitao; Wang, Xin; Wilson, John

    2010-01-01

    This paper introduces a comparison of the magnetic Barkhausen noise (BN) and metal magnetic memory (MMM) testing techniques for stress measurement. BN has become an important non-destructive technique due to its exceptional material and stress characterization capabilities. MMM is a recently developed technique with special ability for stress detection and stress history. In the applied tensile experiment, BN and MMM signals were acquired via a BN measurement system and EMS-2003 MMM instrument. Relationships between magnetic signals and applied tensile stresses were derived from experiment results. The difference and correlation of the two methods are investigated. Conclusions were derived based on the experiment results

  16. Non-destructive testing of biaxial stress state in ferromagnetic materials

    Science.gov (United States)

    Vengrinovich, V. L.; Vintov, D. A.; Dmitrovich, D. V.

    2014-02-01

    The technique for biaxial stress state quantitative non destructive testing using magnetic, namely Barkhausen Noise, measurements is developed and checked experimentally. The main elaboration concerns the application of uni-axial calibration data for bi-axial stress measurement in the material which treatment pre-history is not definitely known. The article is aimed to get over difficulties, accompanying factual nondestructive stress evaluation, implied from its tensor nature. The developed technique of stress calibration and measurement assumes the bi-axial stress components recovery from uni-axial magnetic and Barkhausen noise measurement results. The complete technology, based on new calibration procedure with grid diagrams is considered in the article.

  17. 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…

  18. 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.

  19. 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.

  20. 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...

  1. 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

  2. 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.

  3. 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.

  4. Determination of the hot rolling stress by means of tensile tests

    International Nuclear Information System (INIS)

    Monsalve, A.; Artigas, A.; Celentano, D.; Guzman, A.; Colas, R.; Houbaert, Y.

    2013-01-01

    Prediction of mechanical behavior of hot rolled steels is an important aspect during industrial processing. The rolling stress needed to the process were estimated using three methods, the first of which is related to the Sellars's model that takes into account the friction coefficient and the yield stress. The second method estimates the rolling stress as the average stress obtained during the tensile tests. The third method, estimates the rolling stress from the data of power consumed by the rolling equipment. This methodology was applied in this study to a carbon steel. The conclusion of the work is that results obtained by Sellars's and consumed power, are coincident. The method based on the average tensile stress predicts stresses lower than those obtained with other two methods. (Author) 26 refs.

  5. 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

  6. Validation of a qualitative immunochromatographic test for the noninvasive assessment of stress in dogs.

    Science.gov (United States)

    Di Nardo, F; Anfossi, L; Ozella, L; Saccani, A; Giovannoli, C; Spano, G; Baggiani, C

    2016-08-15

    Salivary cortisol is regarded as a reliable parameter for the noninvasive assessment of the welfare of animals, because it is strictly related to stress levels. Several methods are available for salivary cortisol measurement in mammals, however rapid diagnostic test for detecting salivary cortisol are confined to humans. The availability of such non invasive diagnostic tools operable in situ would facilitate monitoring of animal welfare. The Cortisol stress™ test provides a simple and rapid tool to discriminate cortisol levels in canine saliva above or below 4ng/ml, which has been suggested as the cut-off value for distinguishing unstressed dogs from those experiencing stress. The test is based on a competitive immunochromatographic assay (ICT) using gold nanoparticles as probes, in which the color intensity of the Test line is inversely correlated to the salivary cortisol level. The qualitative result is obtained by the visual observation of the color formed on the Test line compared to that of the Control line We evaluated the accuracy of the test by determining salivary cortisol in 85 samples of canine saliva belonging to dogs with very variable age, sex, breed, and life history, and comparing the qualitative results to those obtained by a reference ELISA kit. Agreeing results were obtained through the two methods, and the ICT showed high diagnostic sensitivity, specificity and efficiency (100%, 98.4%, and 98.8%, respectively). Furthermore, we evaluated the precision of the test by an experimental design approach, which combines errors due to within-day and between-day variation with the biological variability, and demonstrated that the test could be reliably applied for correctly classifying canine samples, according to their salivary cortisol level. Moreover, we studied the shelf-life of the device in three experimental conditions. We confirmed the stability of the ICT at 4°C and 25°C for at least six months and observed similar results for an accelerated

  7. 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.

  8. Replacement of ammonium chloride when processing Scholven coals. (Tests conducted in rotating autoclave at 350 atmosheres. )

    Energy Technology Data Exchange (ETDEWEB)

    Grassl, G.; Schiffmann, F.

    1944-01-03

    Hydrogenation tests were conducted on coal from Scholven in view of difficulties in delivery of ammonium chloride to the Scholven works. The results were, that of the materials containing chlorine, ferrous chloride and water-soluble chlorine-bearing alumina appeared to be first and second choices as replacements for ammonium chloride. Ferrous chloride, used for an equivalent amount of chlorine, gave, other than a bit higher volatilization, the same results as ammonium chloride. Water-soluble chlorine-bearing alumina was found to be just as favorable as the ammonium chloride. But, there was a disadvantage. Since the alumina carried a lesser amount of chloride, a relatively larger amount (5.9%) of the material had to be used. This caused another problem. The increased residual material caused an overload on the reprocessing system. Water-soluble alumina at 1.9% was found to be unsuitable, because volatilization rose considerably with higher temperatures. Hydrated aluminum chloride (AlCl/sub 3/ . 6H/sub 2/O) was significantly more unsuitable than ammonium chloride. It was found that at .3 mV higher temperature, significant improvement could be noted, but certainly at the cost of volatilization, which rose sharply. Two tests of aluminum oxychloride, which contained more chlorine than the water-soluble alumina, showed suitable cracking properties, but figures as good as those obtained with ammonium chloride were not reached in treating asphalt and volatilization. Attempts to activate the chlorine in sodium chloride through ion exchange with ammonium sulfate did not succeed. The resulting substance gave worse results than did aluminum chlorohydrate. 1 table

  9. 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

  10. Study of stress-strain and volume change behavior of emplaced municipal solid waste using large-scale triaxial testing.

    Science.gov (United States)

    Ramaiah, B J; Ramana, G V

    2017-05-01

    The article presents the stress-strain and volume change behavior, shear strength and stiffness parameters of landfilled municipal solid waste (MSW) collected from two dump sites located in Delhi, India. Over 30 drained triaxial compression (TXC) tests were conducted on reconstituted large-scale specimens of 150mm diameter to study the influence of fiber content, age, density and confining pressure on the shear strength of MSW. In addition, a few TXC tests were also conducted on 70mm diameter specimen to examine the effect of specimen size on the mobilized shear strength. It is observed that the fibrous materials such as textiles and plastics, and their percentage by weight have a significant effect on the stress-strain-volume change behavior, shear strength and stiffness of solid waste. The stress-strain-volume change behavior of MSW at Delhi is qualitatively in agreement with the behavior reported for MSW from different countries. Results of large-scale direct shear tests conducted on MSW with an identical composition used for TXC tests revealed the cross-anisotropic behavior as reported by previous researchers. Effective shear strength parameters of solid waste evaluated from this study is best characterized by ϕ'=39° and c'=0kPa for the limiting strain-based failure criteria of K 0 =0.3+5% axial strain and are in the range of the data reported for MSW from different countries. Data presented in this article is useful for the stress-deformation and stability analysis of the dump sites during their operation as well as closure plans. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Many a little makes a mickle: Macro portfolio stress test for small and medium-sized German banks

    OpenAIRE

    Busch, Ramona; Koziol, Philipp; Mitrovic, Marc

    2015-01-01

    We develop a macroeconomic portfolio stress test that is specifically geared towards small and medium-sized banks. We combine a credit risk stress test which simulates credit impairments via a CreditMetrics type multi-factor portfolio model with an income stress test in the form of dynamic panel data regressions. Based on a stress scenario that extends experience of the financial crisis by integrating the current low interest rate environment, we analyse the stress impact on banks' capital ra...

  12. Direct effect of chronic hypoxia in suppressing large conductance Ca(2+)-activated K(+) channel activity in ovine uterine arteries via increasing oxidative stress.

    Science.gov (United States)

    Hu, Xiang-Qun; Huang, Xiaohui; Xiao, Daliao; Zhang, Lubo

    2016-01-15

    Chronic hypoxia has a direct effect in down-regulating the BKCa channel β1 subunit and inhibiting the BKCa channel activity in uterine arteries of pregnant sheep. Oxidative stress plays a causal role in hypoxia-mediated suppression of BKCa channel function. The steroid hormone-induced effect on BKCa channels is a target of hypoxia-mediated oxidative stress. Inhibition of oxidative stress ameliorates the adverse effect of hypoxia both ex vivo and in vivo in pregnant sheep exposed to long-term high-altitude hypoxia. Our findings provide novel evidence of a causative role of oxidative stress in hypoxia-mediated inhibition of the BKCa channel activity in uterine arteries and new insights in understanding and alleviating pregnancy complications associated with gestational hypoxia such as pre-eclampsia and fetal growth restriction. Uterine arteries of pregnant sheep acclimatized to long-term high-altitude hypoxia were associated with a decrease in large-conductance Ca(2+)-activated K(+) (BKCa) channel activity. The present study tested the hypothesis that prolonged hypoxia has a direct effect in suppressing BKCa channel activity by increasing oxidative stress. Uterine arteries were isolated from non-pregnant and near-term (∼142 days) pregnant sheep, and were treated ex vivo with 21.0 or 10.5% O2 for 48 h. The hypoxia treatment significantly increased the production of reactive oxygen species in uterine arteries, which was blocked by N-acetylcysteine. In uterine arteries of pregnant sheep, hypoxia significantly inhibited BKCa channel current density, decreased NS1619-induced relaxations and increased pressure-dependent tone, which were annulled by N-acetylcysteine. In accordance, hypoxia resulted in down-regulation of BKCa channel β1 subunit, which was restored in the presence of N-acetylcysteine. In addition, the N-acetylcysteine treatment significantly increased BKCa channel β1 subunit abundance and BKCa channel current density in uterine arteries from pregnant

  13. 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.

  14. 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.

  15. Preparation, characterization and single cell testing of new ionic conducting polymers for fuel cell applications

    Science.gov (United States)

    Escribano, P. G.; del Río y, C.; Acosta, J. L.

    In this work, heterogeneous sulfonation and both, structural and electrical characterization of a mixture composed on block copolymer ionomers (HSBS and EPDM) and commercial silica, are studied. The incorporation of sulfonic groups was checked by infrared spectroscopy (FTIR-ATR). Microstructure was studied by means of dynamic mechanical analysis (DMA). Also, water uptake and methanol crossover were determined, and the results were compared with those of Nafion ® 117. Electrical behavior was recorded by means of electrochemical impedance spectroscopy (EIS) at different hydration times. Results show that sulfonation of the styrene rings has effectively occurred. Conductivity values are similar to Nafion and they improve with hydration time. Methanol crossover is lower than in Nafion. Finally, a single complete proton exchange membrane fuel cell (PEMFC) as a whole was tested obtaining the polarization and power curves at different temperatures and pressures, and modeling it by an electrical equivalent circuit (EC) in the symmetrical mode (SM) configuration using the EIS technique. This study offers a physical interpretation relating physical parameters to several processes occurring in the system. Power density values are higher than in Nafion.

  16. 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)

  17. Experimenter Effects on Cardiovascular Reactivity and Task Performance during Mental Stress Testing

    Science.gov (United States)

    Siegwarth, Nicole; Larkin, Kevin T.; Kemmner, Christine

    2012-01-01

    Experimenter effects have long been hypothesized to influence participants' responses to mental stress testing. To explore the influence of experimenter warmth on responses to two mental stress tasks (mental arithmetic, mirror tracing), 32 young women participated in a single 45-min experimental session. Participants were randomized into warm…

  18. [New kidney function tests: Renal functional reserve and furosemide stress test].

    Science.gov (United States)

    Kindgen-Milles, D; Slowinski, T; Dimski, T

    2018-01-11

    Acute kidney injury (AKI) occurs in 30-50% of all intensive care patients. Renal replacement therapy (RRT) has to be initiated in 10-15%. The early in-hospital mortality is about 50%. Up to 20% of all survivors develop chronic kidney disease after intensive care discharge and progress to end-stage kidney disease within the next 10 years. For timely initiation of prophylactic or therapeutic interventions, it is crucial to exactly determine the actual kidney function, i. e., glomerular filtration rate (GFR), and to gain insight into the further development of kidney function. Traditionally, renal function has been estimated using serum levels of creatinine or urea. Unfortunately, both are notoriously unreliable and insensitive in intensive care patients. Cystatin C has fewer non-GFR determinants when compared to creatinine and is more sensitive and accurate to detect early decreases of GFR. At present, new functional tests are discussed, namely the furosemide stress test (FST) and renal functional reserve (RFR). The FST consists of an intravenous infusion of 1.0-1.5 mg/kgBW furosemide to critically ill patients with AKI. An increase in urine output to >100 ml/h is indicative of a GFR >20 ml/min and almost certainly excludes progression to AKI stage III and need for RRT. Estimation of RFR can be made by short-term oral or intravenous administration of a high protein load. A subsequent increase in GFR defines the presence and the magnitude of functional reserve which can be activated. Loss of RFR is an indicator of loss of functioning nephron mass and incomplete recovery following AKI. Both FST and RFR can help to improve diagnosis and care of high-risk patients with acute and chronic kidney disease.

  19. 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.

  20. Safety and feasibility of dobutamine-atropine stress echocardiography for the diagnosis of coronary artery disease in diabetic patients unable to perform an exercise stress test

    NARCIS (Netherlands)

    A. Elhendy (Abdou); D. Poldermans (Don); J.J. Bax (Jeroen); P.R. Nierop; M.L. Geleijnse (Marcel); J.R.T.C. Roelandt (Jos); R.T. van Domburg (Ron)

    1998-01-01

    textabstractOBJECTIVE: Dobutamine stress testing is increasingly used for the diagnosis and functional evaluation of coronary artery disease. However, little is known about the safety and feasibility of this stress modality in diabetic patients. RESEARCH DESIGN AND

  1. Stress testing of digital flight-control system software

    Science.gov (United States)

    Rajan, N.; Defeo, P. V.; Saito, J.

    1983-01-01

    A technique for dynamically testing digital flight-control system software on a module-by-module basis is described. Each test module is repetitively executed faster than real-time with an exhaustive input sequence. Outputs of the test module are compared with outputs generated by an alternate, simpler implementation for the same input data. Discrepancies between the two sets of output indicate the possible presence of a software error. The results of an implementation of this technique in the Digital Flight-Control System Software Verification Laboratory are discussed.

  2. Stress mediation in caregivers of cognitively impaired adults: theoretical model testing.

    Science.gov (United States)

    Irvin, B L; Acton, G J

    1996-01-01

    The purpose of the study was to test a midrange model of caregiver stress mediation based on Modeling and Role-Modelpan>ing theory. Perceived support and self-worth were examined to determine if these self-care resources had a mediating effect between stress and well-being in caregivers of cognitively impaired adults. The sample of 117 caregivers completed measures of basic need status, perceived support, self-worth, stress, and well-being. There were significant correlations among the study variables in the expected directions. Resources mediated the relationship between stress and well-being, providing tentative support for theoretically proposed linkages.

  3. 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.

  4. 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...

  5. OFHEO S RISKBASED CAPITAL STRESS TEST: Incorporating New Business Is Not Advisable

    National Research Council Canada - National Science Library

    2002-01-01

    ...)1 that we study whether the Office of Federal Housing Enterprise Oversight (OFHEO) should incorporate new business assumptions into the stress test used to establish risk-based capital requirements...

  6. Clinical value of the thallium-201 stress test: sensitivity and specificity in the detection of coronary artery disease

    International Nuclear Information System (INIS)

    Okada, R.D.; Raessler, K.L.; Woolfenden, J.M.; Groves, B.M.; Patton, D.; Goldman, S.; Hager, W.D.

    1978-01-01

    Rest and exercise thallium-201 scintigraphy ( 201 Tl stress test), 90% submaximal treadmill exercise test (ECG stress test), and coronary angiography were performed on 49 patients with suspected coronary artery disease. When technically unsatisfactory and uninterpretable scintiphotos were excluded, the sensitivity (true positives/true positives + false negatives) of the 201 Tl stress test in detecting coronary artery stenosis >= 70% was 81%. The sensitivity of the 201 Tl stress test in detecting coronary artery stenosis >= 50% was 84%. However, when technically unsatisfactory and uninterpretable studies were considered as failures of the test to detect disease, the sensitivity of the 201 Tl stress test in detecting coronary artery stenosis >= 50% was 71%. The sensitivity of the ECG stress test was 92% in detecting stenosis >= 70% and 85% in detecting stenosis >= 50% when non-diagnostic tests were excluded. However, when 11 non-diagnostic ECG stress tests were considered as a failure of the test to detect disease, the sensitivity of the ECG stress test in detecting coronary artery stenosis >= 50% was 64%. The sensitivity of the combined stress test in detecting coronary artery stenosis >= 50% was high whether or not technically unsatisfactory and uninterpretable studies were (89%) or were not (94%) included in the analysis. The specificity (true negatives/true negatives + false positives) for >= 50% coronary artery stenosis was 90% for the 201 Tl stress test, 75% for the ECG stress test and 80% for the combined stress test. Combined ECG and 201 Tl stress testing detects a number of patients with significant coronary artery disease missed by ECG stress testing alone, primarily in those cases where the ECG stress test is non-diagnostic. (author)

  7. 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

  8. An Automatic System of Testing the Best Stress of Installation for Semiconductor Refrigeration Piece

    Science.gov (United States)

    Chen, Hongyan; Song, Ping

    Concerning the problems of the impact on the factors of installation about semiconductor refrigeration piece are rarely studied in China and abroad, a reasonable structure of test device is designed, using stepper motor to test the temperature of the cold surface under different stress of installation to get the best stress of installation for the semiconductor refrigeration piece. Experiments shows that the system is of good noise immunity, high controlling and measuring precision.

  9. Modifications of system for elevated temperature tensile testing and stress-strain measurement of metal matrix composites

    Science.gov (United States)

    Diaz, J. O.

    1985-01-01

    Composites consisting of tungsten alloy wires in superalloy matrices are being studied because they offer the potential for increased strength compared to current materials used at temperatures up to at least 1093 C (2000F). Previous research at the NASA Lewis Research Center and at other laboratories in the U.S., Europe, and Japan has demonstrated laboratory feasibility for fiber reinforced superalloys (FRS). The data for the mechanical and physical properties used to evaluate candidate materials is limited and a need exists for a more detailed and complete data base. The focus of this work is to develop a test procedure to provide a more complete FRS data base to quantitatively evaluate the composite's potential for component applications. This paper will describe and discuss the equipment and procedures under development to obtain elevated temperature tensile stress-strain, strength and modulus data for the first generation of tungsten fiber reinforced superalloy composite (TFRS) materials. Tensile stress-strain tests are conducted using a constant crosshead speed tensile testing machine and a modified load-strain measuring apparatus. Elevated temperature tensile tests are performed using a resistance wound commercial furnace capable of heating test specimens up to 1093 C (2000 F). Tensile stress-strain data are obtained for hollow tubular stainless steel specimens serving as a prototype for future composite specimens.

  10. The association between conduct problems and maltreatment: testing genetic and environmental mediation.

    Science.gov (United States)

    Schulz-Heik, R Jay; Rhee, Soo Hyun; Silvern, Louise E; Haberstick, Brett C; Hopfer, Christian; Lessem, Jeffrey M; Hewitt, John K

    2010-05-01

    It is often assumed that childhood maltreatment causes conduct problems via an environmentally mediated process. However, the association may be due alternatively to either a nonpassive gene-environment correlation, in which parents react to children's genetically-influenced conduct problems by maltreating them, or a passive gene-environment correlation, in which parents' tendency to engage in maltreatment and children's conduct problems are both influenced by a hereditary vulnerability to antisocial behavior (i.e. genetic mediation). The present study estimated the contribution of these processes to the association between maltreatment and conduct problems. Bivariate behavior genetic analyses were conducted on approximately 1,650 twin and sibling pairs drawn from a large longitudinal study of adolescent health (Add Health). The correlation between maltreatment and conduct problems was small; much of the association between maltreatment and conduct problems was due to a nonpassive gene-environment correlation. Results were more consistent with the hypothesis that parents respond to children's genetically-influenced conduct problems by maltreating them than the hypothesis that maltreatment causes conduct problems.

  11. 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

  12. Characterization of Min-K TE-1400 Thermal Insulation (Two-Year Gradient Stress Relaxation Testing Update)

    Energy Technology Data Exchange (ETDEWEB)

    Hemrick, James Gordon [ORNL; Lara-Curzio, Edgar [ORNL; King, James [ORNL

    2009-09-01

    Min-K 1400TE insulation material was characterized at Oak Ridge National Laboratory for use in structural applications under gradient temperature conditions. A previous report (ORNL/TM-2008/089) discusses the testing and results from the original three year duration of the project. This testing included compression testing to determine the effect of sample size and test specimen geometry on the compressive strength of Min-K, subsequent compression testing on cylindrical specimens to determine loading rates for stress relaxation testing, isothermal stress relaxation testing, and gradient stress relaxation testing. This report presents the results from the continuation of the gradient temperature stress relaxation testing and the resulting updated modeling.

  13. 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…

  14. 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.

  15. Study of efficacy and safety of pharmacological stress tests in nuclear cardiology

    Directory of Open Access Journals (Sweden)

    Baškot Branislav

    2009-01-01

    Full Text Available Background/Aim. Treadmill test combined with myocardial perfusion scintigraphy (MPS is a commonly used technique in the assessment of coronary artery disease. Many patients who cannot adequately perform exercise stress testing may nevertheless undergo pharmacological tests, most commonly with the vasodilator agents (adenosine and dipyridamole, as well as the positive inotropic agent dobutamine. Patients undergoing vasodilators stress testing with either dipyridamole or adenosine also perform simultaneous low-intensity exercise. The aim of this study was to compare various pharmacological stress tests alone or in combination with low intensity exercise as preparation for MPS in reagard to incidence of adverse effects, quality of diagnostic image and the acquisition initial time. Methods. A total of 2 205 patients underwent pharmacological stress tests. Pharmacological stress test with adenosine was applied in 493 patients. In 405 of them we performed concomitant low level exercise (50 W by bicycle ergometar (AdenoEX. In 88 of them we performed adenosine abbreviated protocol (AdenoSCAN. In 1 526 patients we performed pharmacological stress test with dipyridamole. In 871 of them we performed concomitant low level exercise (50 W by bicycle ergometar (DipyEX, and in 775 we used only dipyridamole protocol (DipySCAN. In 186 patients we used pharmacological stress test with dobutamine. We followed side effects of adenosine, dipyiridamole and dobutamine, compared results between protocols with concomitant low level exercise and vasodilatators only. We also compared image quality, and suggested time of acquisition after stress test. Results. We found numerous side effects especially with adenosine, but these effects were short-lived and not required active interventions. Benefit with concomitant exercise in booth AdenoEX and DipyEX included decreased side effects (AdenoEX vs AdenoSCAN 62% vs 87%, respectively, and DipyEX vs DipySCAN 37% vs 59

  16. Change of residual stresses during plastic deformation under uniaxial tension test

    International Nuclear Information System (INIS)

    Benito, J. A.; Jorba, J.; Roca, A.

    2001-01-01

    Hang of longitudinal and transverse residual stresses was studied by X Ray diffraction method as the applied plastic deformation, measured as A% was increased in a standard tension test. The starting material, hot rolling Armco iron, has values close to 0 MPa in longitudinal direction. But it reaches 600 MPa with only A=1,5%, this value remains constant until necking is produced. In transverse direction the stating values are 300 MPa, changes are small and residual stresses remain compressive until the end of tension test. In addition, studies of the changes of residual stresses with time and with misalignment between incident X Ray and drawing direction are presented. (Author) 5 refs

  17. A continuous damage model based on stepwise-stress creep rupture tests

    Science.gov (United States)

    Robinson, D. N.

    1985-01-01

    A creep damage accumulation model is presented that makes use of the Kachanov damage rate concept with a provision accounting for damage that results from a variable stress history. This is accomplished through the introduction of an additional term in the Kachanov rate equation that is linear in the stress rate. Specification of the material functions and parameters in the model requires two types of constituting a data base: (1) standard constant-stress creep rupture tests, and (2) a sequence of two-step creep rupture tests.

  18. HARDENING MONITORING AND CONTACT STRESS ANALYSIS OF TEST SAMPLES

    Directory of Open Access Journals (Sweden)

    Milan ŽMINDÁK

    2014-09-01

    Full Text Available The presented paper deals with the solution of rolling contact problem. A virtual model was created in Abaqus FEA software. The boundary conditions and contact forces were subsequently added. The results obtained after the simulation were compared with data obtained by experimental measurements, which were performed on the test stand ELSPO used in theoretical and technological center for plastometer construction materials for experimental analyzes and tests in terms of rolling contact of solids. The FEM simulation and experiment observed the size of the contact pressure, plastic deformation and the width of the track, which was the site of contact.

  19. 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

  20. Frequency of stress testing to document ischemia prior to elective percutaneous coronary intervention.

    Science.gov (United States)

    Lin, Grace A; Dudley, R Adams; Lucas, F L; Malenka, David J; Vittinghoff, Eric; Redberg, Rita F

    2008-10-15

    Guidelines call for documenting ischemia in patients with stable coronary artery disease prior to elective percutaneous coronary intervention (PCI). To determine the frequency and predictors of stress testing prior to elective PCI in a Medicare population. Retrospective, observational cohort study using claims data from a 20% random sample of 2004 Medicare fee-for-service beneficiaries aged 65 years or older who had an elective PCI (N = 23 887). Percentage of patients who underwent stress testing within 90 days prior to elective PCI; variation in stress testing prior to PCI across 306 hospital referral regions; patient, physician, and hospital characteristics that predicted the appropriate use of stress testing prior to elective PCI. In the United States, 44.5% (n = 10 629) of patients underwent stress testing within the 90 days prior to elective PCI. There was wide regional variation among the hospital referral regions with stress test rates ranging from 22.1% to 70.6% (national mean, 44.5%; interquartile range, 39.0%-50.9%). Female sex (adjusted odds ratio [AOR], 0.91; 95% confidence interval [CI], 0.86-0.97), age of 85 years or older (AOR, 0.83; 95% CI, 0.72-0.95), a history of congestive heart failure (AOR, 0.85; 95% CI, 0.79-0.92), and prior cardiac catheterization (AOR, 0.45; 95% CI, 0.38-0.54) were associated with a decreased likelihood of prior stress testing. A history of chest pain (AOR, 1.28; 95% CI, 1.09-1.54) and black race (AOR, 1.26; 95% CI, 1.09-1.46) increased the likelihood of stress testing prior to PCI. Patients treated by physicians performing 150 or more PCIs per year were less likely to have stress testing prior to PCI (AOR, 0.84; 95% CI, 0.77-0.93). No hospital characteristics were associated with receipt of stress testing. The majority of Medicare patients with stable coronary artery disease do not have documentation of ischemia by noninvasive testing prior to elective PCI.

  1. 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.

  2. 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

    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...... length of the hydraulic conductivity has been determined for each of the three hydrogeological layers and is found to be small (1–2.5 m). The asymptotic longitudinal dispersivity of the aquifer has been estimated from the variance in hydraulic conductivity and the horizontal correlation length...

  3. Exercise Stress Testing in Children with Metabolic or Neuromuscular Disorders

    Directory of Open Access Journals (Sweden)

    Tim Takken

    2010-01-01

    Full Text Available The role of exercise as a diagnostic or therapeutic tool in patients with a metabolic disease (MD or neuromuscular disorder (NMD is relatively underresearched. In this paper we describe the metabolic profiles during exercise in 13 children (9 boys, 4 girls, age 5–15 yrs with a diagnosed MD or NMD. Graded cardiopulmonary exercise tests and/or a 90-min prolonged submaximal exercise test were performed. During exercise, respiratory gas-exchange and heart rate were monitored; blood and urine samples were collected for biochemical analysis at set time points. Several characteristics in our patient group were observed, which reflected the differences in pathophysiology of the various disorders. Metabolic profiles during exercises CPET and PXT seem helpful in the evaluation of patients with a MD or NMD.

  4. RELIABILITY AND VALIDITY OF A TEST AND ITS PROCEDURE CONDUCTED AT A JAPANESE HIGH SCHOOL

    OpenAIRE

    Nadasdy,Paul Bela

    2011-01-01

    This paper analyses the validity and reliability of an English listening test being used at a private Japanese high school. Through an analysis of the test results,an attempt was made to make salient the qualities and deficiencies of the test and its procedure.The test's reliability was analysed using a split-half method measuring the coefficient of internal consistency. The split-test's coefficient results suggested that there was a certain amount of unreliability between the two halves of t...

  5. 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.

  6. Failure Modes in Capacitors When Tested Under a Time-Varying Stress

    Science.gov (United States)

    Liu, David (Donhang)

    2011-01-01

    Steady step surge testing (SSST) is widely applied to screen out potential power-on failures in solid tantalum capacitors. The test simulates the power supply's on and off characteristics. Power-on failure has been the prevalent failure mechanism for solid tantalum capacitors for decoupling applications. On the other hand, the SSST can also be reviewed as an electrically destructive test under a time-varying stress. It consists of rapidly charging the capacitor with incremental voltage increases, through a low resistance in series, until the capacitor under test is electrically shorted. Highly accelerated life testing (HALT) is usually a time-efficient method for determining the failure mechanism in capacitors; however, a destructive test under a time-varying stress like SSST is even more effective. It normally takes days to complete a HALT test, but it only takes minutes for a time-varying stress test to produce failures. The advantage of incorporating specific time-varying stress into a statistical model is significant in providing an alternative life test method for quickly revealing the failure modes in capacitors. In this paper, a time-varying stress has been incorporated into the Weibull model to characterize the failure modes. The SSST circuit and transient conditions to correctly test the capacitors is discussed. Finally, the SSST was applied for testing polymer aluminum capacitors (PA capacitors), Ta capacitors, and multi-layer ceramic capacitors with both precious metal electrode (PME) and base-metal-electrodes (BME). It appears that testing results are directly associated to the dielectric layer breakdown in PA and Ta capacitors and are independent on the capacitor values, the way the capacitors being built, and the manufactures. The testing results also reveal that ceramic capacitors exhibit breakdown voltages more than 20 times the rated voltage, and the breakdown voltages are inverse proportional to the dielectric layer thickness. The possibility of

  7. 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

  8. Composite Overwrapped Pressure Vessels (COPV) Stress Rupture Test: Part 2. Part 2

    Science.gov (United States)

    Russell, Richard; Flynn, Howard; Forth, Scott; Greene, Nathanael; Kezirian, Michael; Varanauski, Don; Leifeste, Mark; Yoder, Tommy; Woodworth, Warren

    2010-01-01

    One of the major concerns for the aging Space Shuttle fleet is the stress rupture life of composite overwrapped pressure vessels (COPVs). Stress rupture life of a COPY has been defined as the minimum time during which the composite maintains structural integrity considering the combined effects of stress levels and time. To assist in the evaluation of the aging COPVs in the Orbiter fleet an analytical reliability model was developed. The actual data used to construct this model was from testing of COPVs constructed of similar, but not exactly same materials and pressure cycles as used on Orbiter vessels. Since no actual Orbiter COPV stress rupture data exists the Space Shuttle Program decided to run a stress rupture test to compare to model predictions. Due to availability of spares, the testing was unfortunately limited to one 40" vessel. The stress rupture test was performed at maximum operating pressure at an elevated temperature to accelerate aging. The test was performed in two phases. The first phase, 130 F, a moderately accelerated test designed to achieve the midpoint of the model predicted point reliability. A more aggressive second phase, performed at 160 F, was designed to determine if the test article will exceed the 95% confidence interval ofthe model. In phase 3, the vessel pressure was increased to above maximum operating pressure while maintaining the phase 2 temperature. After reaching enough effectives hours to reach the 99.99% confidence level of the model phase 4 testing began when the temperature was increased to greater than 170 F. The vessel was maintained at phase 4 conditions until it failed after over 3 million effect hours. This paper will discuss the results of this test, it's implications and possible follow-on testing.

  9. 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.

  10. 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

  11. 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.

  12. 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)

  13. 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

  14. 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

    the spherical flow model of Karasaki et al. overestimated the results of the tracer tests by approximately a factor 1.4. The Dax and the Cooper et al. methods, assuming only radial flow to the partially screened well, yielded a better approximation of the horizontal hydraulic conductivity, than the Chirlin......A new and efficient mini slug test method for the determination of local hydraulic conductivities in unconfined sandy aquifers is developed. The slug test is performed in a small-diameter (1 inch) driven well with a 0.25 m screen just above the drive point. The screened drive point can be driven...... from level to level and thereby establish vertical profiles of the hydraulic conductivity. The head data from the test well are recorded with a 10 mm pressure transducer, and the initial head difference required is established by a small vacuum pump. The method described has provided 274 spatially...

  15. 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)

  16. Adenosine test in the diagnosis of unexplained syncope: marker of conducting tissue disease or neurally mediated syncope?

    Science.gov (United States)

    Parry, Steve W; Nath, Samiran; Bourke, John P; Bexton, Rodney S; Kenny, Rose Anne

    2006-06-01

    Adenosine test (supine administration of a 20 mg intravenous bolus with electrocardiographic and blood pressure monitoring) has been endorsed by the European Society of Cardiology guidelines on syncope management as an 'experimental' test in the diagnosis of unexplained syncope. The test is quick and cheap, but there is no consensus as to what condition, if any, the adenosine test is exposing, with conducting tissue disease and neurally mediated syncope proposed by various authors. In this article, we review the possible mechanisms underlying a positive adenosine test, its safety, and a comprehensive examination of the literature supporting each of the putative causal diagnoses.

  17. 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.

  18. Development of the Stress of Immigration Survey (SOIS): a Field Test among Mexican Immigrant Women

    Science.gov (United States)

    Sternberg, Rosa Maria; Nápoles, Anna Maria; Gregorich, Steven; Paul, Steven; Lee, Kathryn A.; Stewart, Anita L.

    2016-01-01

    The Stress of Immigration Survey (SOIS) is a screening tool used to assess immigration-related stress. The mixed methods approach included concept development, pretesting, field-testing, and psychometric evaluation in a sample of 131 low-income women of Mexican descent. The 21-item SOIS screens for stress related to language; immigrant status; work issues; yearning for family and home country; and cultural dissonance. Mean scores ranged from 3.6 to 4.4 (1-5 scale, higher is more stress). Cronbach's alphas >.80 for all sub-scales. The SOIS may be a useful screening tool for detecting high levels of immigration-related stress in low-income Mexican immigrant women. PMID:26605954

  19. Development of the Stress of Immigration Survey: A Field Test Among Mexican Immigrant Women.

    Science.gov (United States)

    Sternberg, Rosa Maria; Nápoles, Anna Maria; Gregorich, Steven; Paul, Steven; Lee, Kathryn A; Stewart, Anita L

    2016-01-01

    The Stress of Immigration Survey (SOIS) is a screening tool used to assess immigration-related stress. The mixed methods approach included concept development, pretesting, field testing, and psychometric evaluation in a sample of 131 low-income women of Mexican descent. The 21-item SOIS screens for stress related to language, immigrant status, work issues, yearning for family and home country, and cultural dissonance. Mean scores ranged from 3.6 to 4.4 (a scale of 1-5, higher is more stress). Cronbach α values were more than 0.80 for all subscales. The SOIS may be a useful screening tool for detecting high levels of immigration-related stress in low-income Mexican immigrant women.

  20. 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.

  1. 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.

  2. Partial Shade Stress Test for Thin-Film Photovoltaic Modules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, Timothy J.; Deceglie, Michael G.; Deline, Chris; Kurtz, Sarah

    2015-09-02

    Partial shade of monolithic thin-film PV modules can cause reverse-bias conditions leading to permanent damage. In this work, we propose a partial shade stress test for thin-film PV modules that quantifies permanent performance loss. We designed the test with the aid of a computer model that predicts the local voltage, current and temperature stress that result from partial shade. The model predicts the module-scale interactions among the illumination pattern, the electrical properties of the photovoltaic material and the thermal properties of the module package. The test reproduces shading and loading conditions that may occur in the field. It accounts for reversible light-induced performance changes and for additional stress that may be introduced by light-enhanced reverse breakdown. We present simulated and experimental results from the application of the proposed test.

  3. A National Guideline for Climate Adaptation Planning : the Climate Stress Test for Urban Areas

    NARCIS (Netherlands)

    van de Ven, F.H.M.; Hoogvliet, M.; Goossen, W.J.

    2016-01-01

    To make urban environments in the Netherlands climate-proof and water-robust the Delta Programme launched guidelines and tools for climate adaptation planning, including a climate stress test. This test builds on new principles and concepts, making spatial adaptation a key element of building

  4. Experimental determination of thermal conductivity of soil with a thermal response test

    OpenAIRE

    Banjac Miloš J.; Todorović Maja N.; Ristanović Milan R.; Galić Radoslav D.

    2012-01-01

    Optimal design of a borehole heat exchanger, as the outer part of a ground source heat pump heating system, requires information on the thermal properties of the soil. Those data, the effective thermal conductivity of the soil λeff and the average temperature of the soil T0, enable us to determine the necessary number and depth of boreholes. The determination of thermal conductivity of the soil in laboratory experiments does not usually coincide with the data under in-situ conditions. T...

  5. 40 CFR 62.15250 - May I conduct stack testing less often?

    Science.gov (United States)

    2010-07-01

    ... Federal Plan Requirements for Small Municipal Waste Combustion Units Constructed on or Before August 30... you own or operate a Class II municipal waste combustion unit and if all stack tests for a given..., opacity, hydrogen chloride, and fugitive ash. (b) You can test less often for dioxins/furans emissions if...

  6. 40 CFR 60.1795 - May I conduct stack testing less often?

    Science.gov (United States)

    2010-07-01

    ... Times for Small Municipal Waste Combustion Units Constructed on or Before August 30, 1999 Model Rule... or operate a Class II municipal waste combustion unit and if all stack tests for a given pollutant..., hydrogen chloride, and fugitive ash. (b) You can test less often for dioxins/furans emissions if you own or...

  7. 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

  8. 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.

  9. Neutron measurements of stresses in a test artifact produced by laser-based additive manufacturing

    International Nuclear Information System (INIS)

    Gnäupel-Herold, Thomas; Slotwinski, John; Moylan, Shawn

    2014-01-01

    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

  10. Neutron measurements of stresses in a test artifact produced by laser-based additive manufacturing

    Science.gov (United States)

    Gnäupel-Herold, Thomas; Slotwinski, John; Moylan, Shawn

    2014-02-01

    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.

  11. Venlafaxine protects against stress-induced oxidative DNA damage in hippocampus during antidepressant testing in mice.

    Science.gov (United States)

    Abdel-Wahab, Basel A; Salama, Ragaa H

    2011-11-01

    Venlafaxine (VLF) is an approved antidepressant that is claimed to have superior clinical efficacy to comparable drugs. Recently, many studies showed the relationship between depression and increased oxidative stress. This study investigated the relationship between the antidepressant effect of VLF and its ability to protect animals against stress-induced oxidative lipid peroxidation and DNA damage induced during antidepressant testing. The antidepressant effect of long-term treatment (21 days) of VLF in doses 5, 10 and 20mg/kg/day, i.p. was tested using forced swimming test (FST) and tail suspension test (TST). The effects of VLF on hippocampal lipid peroxidation (MDA), nitric oxide (NO), glutathione (GSH), total antioxidant (TAC) levels and glutathione-S-transferase (GST) activity were tested. Furthermore, the corresponding changes in serum and hippocampal 8-hydroxy-2'-deoxyguanosine (8-OHdG) were measured. Long-term VLF treatment showed a significant, antidepressant effect in both FST and TST. VLF could decrease the hippocampal MDA and NO and to increase hippocampal GSH and TAC levels and GST activity in the tested animals. Only GSH and TAC levels were increased by VLF in the non-tested animals. In addition, both serum and hippocampal 8-OHdG levels were significantly reduced by VLF in animals exposed to antidepressant tests. Long-term VLF treatment in the effective antidepressant doses can protect against stress-induced oxidative cellular and DNA damage. This action may be through antagonizing the oxidative stress and enhancing the antioxidant defense mechanisms. Consequently, pharmacological modulation of stress-induced oxidative DNA damage as a possible stress-management approach should be an important avenue of further research. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. 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…

  13. Hydraulic Tomography and High-Resolution Slug Testing to Determine Hydraulic Conductivity Distributions - Year 2

    Science.gov (United States)

    2006-12-01

    Kansas Department of Geology Brett R. Engard Carl D. McElwee Rick Devlin Brian Wachter Benjamin Ramaker Annual Report SERDP...stochastic processes or fractal representations. It is becoming increasingly apparent, however, that site- specific features of the hydraulic conductivity

  14. 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...

  15. 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.

  16. 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

  17. Tests for the determination of the stress condition in tension fields

    Science.gov (United States)

    Lahde, R; Wagner, H

    1936-01-01

    The present experiments treat the stress of actual tension fields within the elastic range. They give the magnitude of the flexural stresses due to wrinkling. They also disclose, particularly by slightly exceeded buckling load, the marked unloading - as compared with the tension-field theory - of the uprights as a result of the flexural stiffness of the web plate. The test sheets were clamped at the edges and brought to buckling through shearing and compressive stresses applied in the direction of the long sides.

  18. [Evaluation of the empty bladder stress test in supine position as a marker of severity and quality of life in women with stress urinary incontinence].

    Science.gov (United States)

    Arribillaga, Leandro; Ledesma, Marta; Bengió, Rubén G; Montedoro, Ariel; Pisano, Florencia; Orellana, Sergio; García Önto, Hernán; Bengió, Rubén H

    2016-06-01

    To assess the association between empty bladder stress test and objective and subjective measures of stress urinary incontinence (SUI) severity. Prospective, analytic and descriptive study of females with diagnosis of stress urinary incontinence referred for urodynamics study. Every patient underwent medical history (including number of daily pads) and physical examination, ISIQ-SF and short IIQ-7 questionnaires, and full urodynamic study, including the measurment of the abdominal leak pressure point (ALPP). Positive empty stress test was defined as stress urine leak on physical exam after uroflowmetry evacuation and in absence of significant post-void residual. To evaluate the relationship between empty bladder stress test and each one of the stress urinary incontinence severity measures, Stundent's t test was performed, considering a 〈0.05 value statistically significant. 107 patients were studied in the final analysis; of them 49 had empty bladder stress test (+) and 58 (-). Patients with positive test wet a greater number of protectors per day (3.9 vs 2.8; p 0.013), higher ICIQSF score (15.04 vs 12.22; p 0.0007), higher IIQ-7 score (52.2 vs 37.5; p 0.0049) and lower urodynamics ALPP (73 cm H2O vs 91 cm H2O; p 0.0002). Patients with SUI and positive empty bladder stress test had a strong association with the objective and subjective perception of urine incontinence severity with a negative impact in patients quality of life.

  19. 40 CFR 63.2162 - When must I conduct subsequent performance tests?

    Science.gov (United States)

    2010-07-01

    ... monitoring brew ethanol concentration and calculating VOC concentration in the fermenter exhaust according to..., performance test and establish a brew-to-exhaust correlation according to the procedures in Table 2 to this...

  20. The Pinocchio effect and the Cold Stress Test: Lies and thermography.

    Science.gov (United States)

    Moliné, A; Gálvez-García, G; Fernández-Gómez, J; De la Fuente, J; Iborra, O; Tornay, F; Mata Martín, J L; Puertollano, M; Gómez Milán, E

    2017-11-01

    We applied the use of thermography to cognitive neuropsychology, particularly as an objective marker of subjective experiences, in the context of lying. We conducted three experiments: (a) An important lie was invented by the participants in 3 min, and it was recounted by phone to a significant person while they were recorded by the thermographic camera, obtaining a face and hands map of the lie. (b) A similar methodology was carried out, but adding the Cold Stress Test (CST) of the dominant hand during the phone call, obtaining a second physiologic marker (the percentage of thermal recovery) to detect the lie. Further, it established a control condition where it generated anxiety in the participants using IAPS images with negative valence and high arousal, which were described by phone to a loved one. We obtained results that showed significant correlations between changes in body temperature and mental set. Of particular interest was the temperature of the nose and hand, which tended to decrease during lying (Experiment 1). The participants also showed a lower recovery of the temperature after the CST when they were lying (Experiment 2). (c) Experiment 3 is a replication of Experiment 2 but with a different type of lie (a more ecological task) in a different scenario (following the ACID interview, with the use of the phone eliminated and participants motivated to lie well). The main pattern of results was replicated. We obtained an accuracy of 85% in detection of deception with 25% of false alarms. © 2017 Society for Psychophysiological Research.

  1. 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.

  2. 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).

  3. 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.

  4. 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

  5. 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

  6. 40 CFR 60.1305 - May I conduct stack testing less often?

    Science.gov (United States)

    2010-07-01

    ... Municipal Waste Combustion Units for Which Construction is Commenced After August 30, 1999 or for Which... combustion unit and if all stack tests for a given pollutant over 3 consecutive years show you comply with...: dioxins/furans, cadmium, lead, mercury, particulate matter, opacity, hydrogen chloride, and fugitive ash...

  7. CitySpace Air Sensor Network Project Conducted to Test New Monitoring Capabilities

    Science.gov (United States)

    The CitySpace project is a new research effort by EPA to field test new, lower-cost air pollution sensors in a mid-sized city to understand how this emerging technology can add valuable information on air pollution patterns in neighboorhoods.

  8. Hydraulic Tomography and High-Resolution Slug Testing to Determine Hydraulic Conductivity Distributions

    Science.gov (United States)

    2011-02-01

    theories have been developed to quantify, in a generic sense, the influence of these variations using stochastic processes or fractal representations. It...Analysis of pulse interference tests. Water Resources Research 25. No. 11:2377-2387 O’Conner, H.G., 1960, Geology and ground-water resources of

  9. Short-time, high temperature mechanical testing of electrically conductive materials

    International Nuclear Information System (INIS)

    Marion, R.H.; Karnes, C.H.

    1976-01-01

    The design and fabrication of a system to obtain information on short-time high temperature properties of materials are described. Components of the system are described in sections on load application, specimen heating temperature measurement, longitudinal temperature gradient, and strain measurement. Results of tests using stainless steel and graphite specimens are included

  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

    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

  11. 49 CFR Appendix E to Part 240 - Recommended Procedures for Conducting Skill Performance Tests

    Science.gov (United States)

    2010-10-01

    ... train. It can be modified to serve in instances where a locomotive simulator is employed for testing... of locomotive engineer performance. The Need for a Systematic Approach There are numerous criteria... rules. Any railroad that fails to have adequate operating, safety, or train handling rules will...

  12. 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.…

  13. 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.

  14. 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.

  15. 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.

  16. Characterization of Multiaxial Stress-Strain Response of Tube Metal from Double-Sided Hydro-Bulging Test Based on Hosford's 1979 Yield Criterion

    Science.gov (United States)

    Cui, Xiao-Lei; Yang, Zhai-Ping; Wang, Xiao-Song

    2017-05-01

    To further explore the characterization of the multiaxial stress-strain responses of anisotropic tube metal from double-sided hydro-bulging tests, an analytical model for the equivalent stress and equivalent strain calculation was derived based on Hosford's 1979 yield criterion. Furthermore, thin-walled 5052-O aluminum alloy tubes were used to conduct the bulging experiment with an external pressure of 85 MPa. After the experimental data were substituted into the above analytical model, the Voce equation was used to fit the equivalent stress-strain relationship. It is concluded that the stress versus strain curves of the 5052-O tubes are strongly dependent on the loaded stress states, the adopted yield criteria, and the anisotropy coefficients. The external pressure of 85 MPa had little or no effect on the stress versus strain curves of the tubes, but the locations of the multiaxial stress versus strain curves were lower than that of the uniaxial stress versus strain curve. Moreover, the curve from Hosford's 1979 yield criterion not only had a higher saturation stress and material constant value than the curve from Mises and Hill's 1948 yield criteria but also had a dependence on the anisotropy coefficient.

  17. 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)

  18. 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

  19. 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…

  20. 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.

  1. Assessment of Partially Conductive Cracks from Eddy Current Non-Destructive Testing Signals using Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Ladislav Janousek

    2015-01-01

    Full Text Available This paper deals with a three-dimensional non-destructive evaluation of partially conductive cracks from eddy current testing signals. An SUS316L plate specimen containing a crack is non-destructively inspected by the eddy current method using numerical simulations. An extensive database of eddy current response signals is prepared while dimensional parameters of a crack together with its partial conductivity are varied in wide ranges. A Support Vector Machine classification algorithm is employed to solve the electromagnetic inverse problem. The acquired signals are employed for training the algorithm and for testing its performance. It is demonstrated that the Support Vector Machine algorithm is able to properly classify detected defects into proper classes with very high probability even the partial conductivity of a detected crack together with its width are unknown.

  2. 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.

  3. Gender and stress test use in an ED chest pain unit.

    Science.gov (United States)

    Napoli, Anthony; Choo, Esther K

    2012-07-01

    Women with acute coronary syndrome appear to be treated less aggressively than men. However, little is known about potential sex biases in the evaluation of patients with low-risk chest pain admitted to emergency department (ED) chest pain units. This was a secondary analysis of prospectively collected data on consecutively admitted chest pain unit patients in a large-volume academic urban ED. Thrombolysis in myocardial infarction (TIMI) risk prediction and Diamond and Forrestor (D&F) scores were calculated for each patient. χ(2) And t tests were used for univariate comparisons of demographics, cardiac comorbidities, risk scores, and stress testing between sexes. Multivariable logistic regression was used to estimate odds ratios (ORs) for testing based on sex, controlling for race, insurance status, and either TIMI or D&F score. Eight hundred eleven patients were enrolled (48% male, 52% female) in the study. The mean age for men was 52 ± 12 and 54 ± 12 years for women (P stress testing (1.61, 95% CI 1.14-2.29 controlling for TIMI score; OR, 1.69, 95% CI 1.12-2.51 controlling for D&F score). This study demonstrates no association between physician discretionary uses of stress testing based on sex. There is a need for further research on patient- or provider-specific factors that determine stress use and on how differences may affect clinical outcomes. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. A method for mapping topsoil field-saturated hydraulic conductivity in the Cévennes-Vivarais region using infiltration tests conducted with different techniques

    Science.gov (United States)

    Braud, Isabelle; Desprats, Jean-François; Ayral, Pierre-Alain; Bouvier, Christophe; Vandervaere, Jean-Pierre

    2017-04-01

    Topsoil field-saturated hydraulic conductivity, Kfs, is a parameter that controls the partition of rainfall between infiltration and runoff. It is a key parameter in most distributed hydrological models. However, there is a mismatch between the scale of local in situ measurements and the scale at which the parameter is required in models. Therefore it is necessary to design methods to regionally map this parameter at the model scale. The paper propose a method for mapping Kfs in the Cévennes-Vivarais region, south-east France, using more easily available GIS data: geology and land cover. The mapping is based on a data set gathering infiltration tests performed in the area or close to it for more than ten years. The data set is composed of infiltration tests performed using various techniques: Guelph permeameter, double ring and single ring infiltration tests, infiltrometers with multiple suctions. The different methods lead to different orders of magnitude for Kfs rendering the pooling of all the data challenging. Therefore, a method is first proposed to pool the data from the different infiltration methods, leading to a homogenized set of Kfs, based on an equivalent double ring/tension disk infiltration value. Statistical tests showed significant differences in distributions among different geologies and land covers. Thus those variables were retained as proxy for mapping Kfs at the regional scale. This map was compared to a map based on the Rawls and Brakensiek (RB) pedo-transfer function (Manus et al., 2009, Vannier et al., 2016), showing very different patterns between both maps. In addition, RB values did not fit observed values at the plot scale, highlighting that soil texture only is not a good predictor of Kfs. References Manus, C., Anquetin, S., Braud, I., Vandervaere, J.P., Viallet, P., Creutin, J.D., Gaume, E., 2009. A modelling approach to assess the hydrological response of small Mediterranean catchments to the variability of soil characteristics in a

  5. Standard Practice for Making and Using U-Bend Stress-Corrosion Test Specimens

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This practice covers procedures for making and using U-bend specimens for the evaluation of stress-corrosion cracking in metals. The U-bend specimen is generally a rectangular strip which is bent 180° around a predetermined radius and maintained in this constant strain condition during the stress-corrosion test. Bends slightly less than or greater than 180° are sometimes used. Typical U-bend configurations showing several different methods of maintaining the applied stress are shown in Fig. 1. 1.2 U-bend specimens usually contain both elastic and plastic strain. In some cases (for example, very thin sheet or small diameter wire) it is possible to form a U-bend and produce only elastic strain. However, bent-beam (Practice G 39 or direct tension (Practice G 49)) specimens are normally used to study stress-corrosion cracking of strip or sheet under elastic strain only. 1.3 This practice is concerned only with the test specimen and not the environmental aspects of stress-corrosion testing which are discus...

  6. 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)

  7. Salivary cortisol and alpha-amylase: Is there consistency between psychosocial stress test and burdensome work shifts?

    Science.gov (United States)

    Karhula, Kati; Härmä, Mikko; Sallinen, Mikael; Lindholm, Harri; Hirvonen, Ari; Elovainio, Marko; Kivimäki, Mika; Vahtera, Jussi; Puttonen, Sampsa

    2017-12-01

    This study examined the consistency of salivary cortisol and alpha-amylase (sAA) total daily secretion between laboratory and field circumstances. The 95 participants were shift working female health care professionals with high (n = 53) or low (n = 42) psychosocial stress (job strain) measured by the Job Content Questionnaire (JCQ). The Trier Social Stress Test including a 5-min free speech and a mental arithmetic task was conducted with four, and field measurements with three daily saliva samples of cortisol and sAA during circadian rhythm and inter-shift recovery controlled morning shift, night shift, and a day off. The associations of salivary cortisol and sAA area under the curve with respect to ground (AUCg) and area under the curve with respect to increase (AUCi) between laboratory and field were tested using OLS (Ordinary Least Squares) regression. The sAA AUCg output in the laboratory was correlated with the output during all field measurement days and similarly among high and low job strain groups (p < 0.001). SAA AUCi and salivary cortisol AUCg and AUCi were not correlated between laboratory and field measurement, neither in the whole sample nor among the low or high job strain group. In conclusion, a laboratory measure of sAA AUCg output is promising in predicting stress-related output during burdensome work shifts and leisure time, whereas sAA AUCi or salivary cortisol seem not to have this potential.

  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

    penetration rate. Also evaluated and presented in this paper is how cone resistance obtained under partially drained conditions underestimates the interpreted relative density Dr and friction angle ?. Triaxial test results on undisturbed silt samples were applied for this analysis. © 2015. American Society...... consisted primarily of sandy silt with clay bands. The results illustrated that when the penetration rate is reduced, the cone resistance increases, but the pore pressure decreases. The transition between undrained and fully drained penetration was determined by converting the results into a normalized...

  9. Daily life stress and the cortisol awakening response: testing the anticipation hypothesis.

    Directory of Open Access Journals (Sweden)

    Daniel J Powell

    Full Text Available The cortisol awakening response (CAR is a distinct facet of the circadian cortisol rhythm associated with various health conditions and risk factors. It has repeatedly been suggested that the CAR could be a result of the anticipated demands of the upcoming day (stress anticipation and could support coping with daily life stress. In a sample of 23 healthy participants CARs were assessed on two consecutive days by measures of salivary cortisol upon awakening (S1 and 30 and 45 minutes later, which were aggregated to the area under the curve increase (AUCI. Stress anticipation was assessed immediately after awakening. On the same days, daily life stress and distress were assessed six times per day based on a quasi-randomized design using handheld computers. Associations were tested by day using regression analysis and standard multilevel/mixed effects models for longitudinal data. The CAR AUCI moderated the effect of daily life stress on distress; higher CAR increases were associated with attenuated distress responses to daily life stress on both days (day 1: p = .039; day 2: p = .004 adjusted for age, gender, sleep quality, time of awakening and oral contraceptive use. Lagged-effects and redundancy models showed that this effect was not due to prior-day CAR increases but specific for same day CARs. On day 2, associations between daily life stress and distress were stronger when individuals showed a higher S1 cortisol level, but this effect was similar for S1 on day 1, and the day 2 effect of S1 became non-significant when S1 on day 1 was controlled. No associations were found between stress anticipation and CARs. Findings indicate that the CAR increase is associated with successful coping with same-day daily life stress.

  10. 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.

  11. 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.

  12. Test with different stress measurement methods in two orthogonal bore holes in Aespoe HRL

    International Nuclear Information System (INIS)

    Janson, Thomas; Stigsson, Martin

    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 conclusions

  13. Status of High Power Tests of Normal Conducting Single-Cell Standing Wave Structures

    Energy Technology Data Exchange (ETDEWEB)

    Dolgashev, Valery; /SLAC; Tantawi, Sami; /SLAC; Yeremian, Anahid; /SLAC; Higashi, Yasuo; /KEK, Tsukuba; Spataro, Bruno; /INFN, Rome

    2012-06-25

    Our experiments are directed toward the understanding of the physics of rf breakdown in systems that can be used to accelerate electron beams at {approx}11.4 GHz. The structure geometries have apertures, stored energy per cell, and rf pulse duration close to that of the NLC or CLIC. The breakdown rate is the main parameter that we use to compare rf breakdown behavior for different structures at a given set of rf pulse parameters (pulse shape and peak power) at 60 Hz repetition rate. In our experiments, the typical range of the breakdown rate is from one per few hours to {approx}100 per hour. To date we have tested 29 structures. We consistently found that after the initial conditioning, the behavior of the breakdown rate is reproducible for structures of the same geometry and material, and the breakdown rate dependence on peak magnetic fields is stronger than on peak surface electric fields for structures of different geometries. Below we report the main results from tests of seven structures made from hard copper, soft copper alloys and hard-copper alloys. Additional details on these and other structures will be discussed in future publications.

  14. Standard practice for conducting wire-on-bolt test for atmospheric galvanic corrosion

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1999-01-01

    1.1 This practice covers the evaluation of atmospheric galvanic corrosion of any anodic material that can be made into a wire when in contact with a cathodic material that can be made into a threaded rod. 1.2 When certain materials are used for the anode and cathode, this practice has been used to rate the corrosivity of atmospheres. 1.3 The wire-on-bolt test was first described in 1955 (1), and has since been used extensively with standard materials to determine corrosivity of atmospheres under the names CLIMAT Test (CLassify Industrial and Marine ATmospheres) (2-5) and ATCORR (ATmospheric CORRosivity) (6-9). 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 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 p...

  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. ST-Elevation Myocardial Infarction after Pharmacologic Persantine Stress Test in a Patient with Wellens’ Syndrome

    Directory of Open Access Journals (Sweden)

    Kunal Patel

    2014-01-01

    Full Text Available Wellens’ syndrome, also known as LAD coronary T-wave inversion syndrome, is a characteristic ECG pattern that highly suggests critical stenosis of the proximal left anterior descending (LAD coronary artery. 75% of patients with this finding go on to develop acute anterior wall myocardial infarction within one week unless prevented by early intervention on the culprit lesion. Most instances of ST-elevation occurring during cardiac stress testing have been observed with exercise, with only seven cases reported in the literature with pharmacologic stress. We present a case of a patient with no known cardiac disease who presented with chest pain and an ECG consistent with Wellens’ syndrome that developed an acute anterior wall ST-elevation myocardial infarction after pharmacologic stress test.

  17. Characterization of fractures as water-conducting features in shales. Studies at the Tournemine test site

    International Nuclear Information System (INIS)

    Cabrera, J.; De Windt, L.; Moreau-Le Golvan, Y.; Boisson, J.Y.

    1999-01-01

    The Institute of Protection and Nuclear Safety (IPSN) develops research programs concerning the confining properties of an argillaceous formation at the IPSN Tournemine site (Aveyron, France). This well-consolidated argillaceous media of Jurassic age presents a very low permeability. Water circulations seem to be of very minor importance in the shales, with a main diffusive component for transport. However, recent field studies, from radial boreholes around the Tournemine tunnel and two gallery excavations in the argilites, document a fractured zone of tectonic origin associated with a main fault. It is an interesting case to analyze the fractures and faults in argillaceous media and their past present and future roles in possible fluid transfers. Fracture investigation as water-conducting features for transport is supported by different approaches: structural and tectonics analyses, interpretation of the present water circulation and chemistry, characterisation of the circulation and chemistry of the paleo-fluids through studies of the fracture mineral fillings, and experiments on sorption of radionuclides performed at laboratory. (author)

  18. 78 FR 59165 - Orders: Information Reporting With Respect to Stress Testing of Regulated Entities

    Science.gov (United States)

    2013-09-26

    ... regulated entities their reporting requirements under the framework established by the final rule, and the... FEDERAL HOUSING FINANCE AGENCY 12 CFR Part 1238 [No. 2013-N-11] Orders: Information Reporting With Respect to Stress Testing of Regulated Entities AGENCY: Federal Housing Finance Agency. ACTION: Orders...

  19. Lessons learned from EU stress tests evaluations with regard to external hazards

    International Nuclear Information System (INIS)

    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

  20. Testing a Theoretical Model of the Stress Process in Alzheimer's Caregivers with Race as a Moderator

    Science.gov (United States)

    Hilgeman, Michelle M.; Durkin, Daniel W.; Sun, Fei; DeCoster, Jamie; Allen, Rebecca S.; Gallagher-Thompson, Dolores; Burgio, Louis D.

    2009-01-01

    Purpose: The primary aim of this study was to test the stress process model (SPM; Pearlin, Mullan, Semple, & Skaff, 1990) in a racially diverse sample of Alzheimer's caregivers (CGs) using structural equation modeling (SEM) and regression techniques. A secondary aim was to examine race or ethnicity as a moderator of the relation between latent…

  1. The Implicit Positive and Negative Affect Test : Validity and relationship with cardiovascular stress-responses.

    NARCIS (Netherlands)

    Van, der Ploeg M.M.; Brosschot, J.F.; Thayer, J.F.; Verkuil, B.

    2016-01-01

    Self-report, i.e., explicit, measures of affect cannot fully explain the cardiovascular (CV) responses to stressors. Measuring affect beyond self-report, i.e., using implicit measures, could add to our understanding of stress-related CV activity. The Implicit Positive and Negative Affect Test

  2. 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. 652.100 Section 652.100 Banks and Banking FARM CREDIT ADMINISTRATION FARM CREDIT SYSTEM FEDERAL AGRICULTURAL MORTGAGE CORPORATION FUNDING AND FISCAL AFFAIRS Risk-Based Capital Requirements § 652.100 Audit of...

  3. 77 FR 62396 - Annual Company-Run Stress Test Requirements for Banking Organizations With Total Consolidated...

    Science.gov (United States)

    2012-10-12

    ... projections of its financial and capital position for a two-year calendar period. A bank holding company... Act or Act) requires the Board to issue regulations that require financial companies with total... financial system and the specific needs of individual companies, these stress tests provided valuable...

  4. 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…

  5. 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…

  6. 78 FR 47217 - Proposed Supervisory Guidance on Implementing Dodd-Frank Act Company-Run Stress Tests for Banking...

    Science.gov (United States)

    2013-08-05

    ... Tests for Banking Organizations With Total Consolidated Assets of More Than $10 Billion But Less Than... Company-Run Stress Tests for Banking Organizations with Total Consolidated Assets of more than $10 Billion... Stress Tests for Banking Organizations with Total Consolidated Assets of more than $10 Billion but less...

  7. Combination of change in hematological parameters with exercise stress test to predict coronary artery disease.

    Science.gov (United States)

    Korkmaz, Ahmet; Yıldız, Abdulkadir; Türker Duyuler, Pınar; Duyuler, Serkan; Yılmaz, Samet; Basyigit, Funda; Elalmis, Ozgul Ucar; Guray, Umit; Ileri, Mehmet

    2018-01-01

    Treadmill exercise stress testing for identifying patients with a higher likelihood of coronary artery disease (CAD) before elective coronary angiography is recommended in the current guidelines. In this study, we aimed to evaluate the changes in the hematological parameters before and after exercise stress test in relation with the presence of CAD. A total of 113 patients with chest pain who underwent treadmill exercise testing and coronary angiography were included in this study. Neutrophil count (4.38±0.99 vs 5.19±0.93, Pexercise test in all the patients. Increase in the NLR after exercise test was significantly higher in patients with positive exercise test (n=68) than negative exercise test (n=45) (0.49±0.58 vs 0.19±0.44, P=.016). The sensitivity and specificity of treadmill exercise testing according to coronary angiography was 79% and 64%, respectively. A cut-off point of 0.2 for the change in the NLR in addition to positive treadmill exercise testing had 91% sensitivity and 92% specificity in predicting significant coronary artery stenosis (AUC:0.913, 95% CI: 0.805-1.000, P<.001). Neutrophil to lymphocyte ratio is an important inflammatory marker that can contribute to treadmill ECG testing in predicting CAD. © 2017 Wiley Periodicals, Inc.

  8. Prerequisites, requirements, stresses and strains, training and performance tests for the horses

    OpenAIRE

    Westermann, Katharina

    2013-01-01

    One aim of this study was to investigate the emphasis (requirements, stresses and strains) and the actual qualifying (training guide, performance test) of horses in EAI. Another aim was to work out proposals for a standardizable quality management for those horses (development of a guideline for the utilisation and training as well as a performance test for horses in EAI, an instructor licence “EAI” for suppliers, additions to the education guidelines within the horse-related apprenticeships ...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  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. 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

  15. 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.

  16. Wheat cultivars selected for high Fv/Fm under heat stress maintain high photosynthesis, total chlorophyll, stomatal conductance, transpiration and dry matter

    DEFF Research Database (Denmark)

    Sharma, Dew Kumari; Andersen, Sven Bode; Ottosen, Carl Otto

    2015-01-01

    ) 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...... 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 undermoderate heat stress...

  17. Progress testing in the medical curriculum: students' approaches to learning and perceived stress.

    Science.gov (United States)

    Chen, Yan; Henning, Marcus; Yielder, Jill; Jones, Rhys; Wearn, Andy; Weller, Jennifer

    2015-09-11

    Progress Tests (PTs) draw on a common question bank to assess all students in a programme against graduate outcomes. Theoretically PTs drive deep approaches to learning and reduce assessment-related stress. In 2013, PTs were introduced to two year groups of medical students (Years 2 and 4), whereas students in Years 3 and 5 were taking traditional high-stakes assessments. Staged introduction of PTs into our medical curriculum provided a time-limited opportunity for a comparative study. The main purpose of the current study was to compare the impact of PTs on undergraduate medical students' approaches to learning and perceived stress with that of traditional high-stakes assessments. We also aimed to investigate the associations between approaches to learning, stress and PT scores. Undergraduate medical students (N = 333 and N = 298 at Time 1 and Time 2 respectively) answered the Revised Study Process Questionnaire (R-SPQ-2F) and the Perceived Stress Scale (PSS) at two time points to evaluate change over time. The R-SPQ-2F generated a surface approach and a deep approach score; the PSS generated an overall perceived stress score. We found no significant differences between the two groups in approaches to learning at either time point, and no significant changes in approaches to learning over time in either cohort. Levels of stress increased significantly at the end of the year (Time 2) for students in the traditional assessment cohort, but not in the PT cohort. In the PT cohort, surface approach to learning, but not stress, was a significant negative predictor of students' PT scores. While confirming an association between surface approaches to learning and lower PT scores, we failed to demonstrate an effect of PTs on approaches to learning. However, a reduction in assessment-associated stress is an important finding.

  18. Evaluating mental stress test in coronary artery disease treadmill positive patients

    Directory of Open Access Journals (Sweden)

    H. Singh

    2002-03-01

    Full Text Available Evaluation of CAD is more routinely done by treadmill test (TMT i.e. physical strain than the more frequently occurring mental strain, so a study was planned to assess the provocability of ischaemia by various mental tasks in patient with positive TMT. Thirty educated subjects, positive on TMT were put on a 24 hour holter monitoring. During this time, subjects were assessed by Mental Stress Test (MST by subjecting to various mental tasks - (a Time stress test (b Mental arithmetic test (c Reading test (d Zeigarnik effect test and observed for heart rate, blood pressure and ischaemic/arrhythmia responses. The results showed that the male : female ratio was 14:1 with a mean age of 57 ± 8.03 years. The mean change produced during MST in (a heart rate was 9.16 (SD  ± 1.24/min (b SBP was 8.86 (SD  ± 1.32 mmHg (c rate pressure product was 82x103; which were statistically low (p<0.001 when compared to haemodynamic changes with TMT. Ischaemia was inducible in only one subject by MST and no increased incidence of arrhythmias during MST was noticed. The low yield of inducible ischaemia by MST when compared to TMT could be due to poor haemodynamic responses achieved by MST when compared to responses of TMT (p<0.001. It is concluded that mental stress does produce ischaemic changes. More intense and sustained MST's which could bring about significant haemodynamic changes are required for inducing ischaemia as by TMT. (Med J Indones 2002; 11: 36-40Keywords: coronary, ischaemia, mental task, stress test, treadmill

  19. The effects of cyclic tensile and stress-relaxation tests on porcine skin.

    Science.gov (United States)

    Remache, D; Caliez, M; Gratton, M; Dos Santos, S

    2018-01-01

    When a living tissue is subjected to cyclic stretching, the stress-strain curves show a shift down with the increase in the number of cycles until stabilization. This phenomenon is referred to in the literature as a preconditioning and is performed to obtain repeatable and predictable measurements. Preconditioning has been routinely performed in skin tissue tests; however, its effects on the mechanical properties of the material such as viscoelastic response, tangent modulus, sensitivity to strain rate, the stress relaxation rate, etc….remain unclear. In addition, various physical interpretations of this phenomenon have been proposed and there is no general agreement on its origin at the microscopic or mesoscopic scales. The purpose of this study was to investigate the effect of the cyclical stretching and the stress-relaxation tests on the mechanical properties of the porcine skin. Cyclic uniaxial tensile tests at large and constant strain were performed on different skin samples. The change in the reaction force, and skin's tangent modulus as a function of the number of cycles, as well as the strain rate effect on the mechanical behavior of skin samples after cycling were investigated. Stress-relaxation tests were also performed on skin samples. The change in the reaction force as a function of relaxation time and the strain rate effect on the mechanical behavior of skin samples after the stress-relaxation were investigated. The mechanical behavior of a skin sample under stress-relaxation test was modeled using a combination of hyperelasticity and viscoelasticity. Overall, the results showed that the mechanical behavior of the skin was strongly influenced by cycling and stress relaxation tests. Indeed, it was observed that the skin's resistance decreased by about half for two hours of cycling; the tangent modulus degraded by nearly 30% and skin samples became insensitive to the strain rates and accumulated progressively an inelastic deformation over time during

  20. Comparison of cardiocirculatory and thermal strain of male firefighters during fire suppression to exercise stress test and aerobic exercise testing.

    Science.gov (United States)

    Angerer, Peter; Kadlez-Gebhardt, Silke; Delius, Michael; Raluca, Petru; Nowak, Dennis

    2008-12-01

    Firefighters face a highly increased risk of sudden cardiac death during fire suppression. Medical examinations and physical performance tests are used to screen endangered firefighters. The aim of this study was to determine cardiocirculatory and thermal strain during fire suppression in firefighters and compare it with the strain during medical and performance evaluations. Forty-nine young professional male firefighters were studied during a 30-minute fire operation (FO) in a large fire simulation plant. Measurements were obtained immediately before, during, and after the FO. During the FO, maximum heart rates of 177 +/- 23 beats/min were recorded on average, with 7 subjects exceeding the age-predicted maximum. Body core temperature increased by 0.9 +/- 0.5 degrees C (p stress test as part of the mandatory medical examination, subjects were limited to heart rates of 176 +/- 3.3 beats/min. They reached 155 +/- 13 beats/min during the annual aerobic exercise in turnout gear. During the FO, maximum heart rate was higher than during the stress test in 66% and higher than during the aerobic exercise in 84% of subjects. In conclusion, fire suppression caused an extreme cardiocirculatory strain, with high heart rates that were not sufficiently tested in medical examinations. To increase the yield of screening for firefighters at risk of death during fire suppression, the exercise should equal requirements in a real emergency; in other words, be limited by exhaustion or age-predicted maximum heart rate.

  1. 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

  2. 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

  3. Stress-Dilatancy for Soils. Part II: Experimental Validation for Triaxial Tests

    Directory of Open Access Journals (Sweden)

    Szypcio Zenon

    2016-12-01

    Full Text Available Different forms of the stress-dilatancy relations obtained based on the frictional theory for the triaxial condition are presented. The analysed test data show that the shear resistance of many soils is purely frictional. The angle Φ0 represents the resistance of the soil as a combined effect of sliding and particle rolling on the macro-scale during shear at the critical frictional state. The stress-plastic dilatancy relations differ not only for triaxial compression and extension but also for drained and undrained conditions. The experiment investigated shows the correctness of the frictional state theory in the triaxial condition.

  4. Stress-Dilatancy for Soils. Part II: Experimental Validation for Triaxial Tests

    Science.gov (United States)

    Szypcio, Zenon

    2016-12-01

    Different forms of the stress-dilatancy relations obtained based on the frictional theory for the triaxial condition are presented. The analysed test data show that the shear resistance of many soils is purely frictional. The angle Φ0 represents the resistance of the soil as a combined effect of sliding and particle rolling on the macro-scale during shear at the critical frictional state. The stress-plastic dilatancy relations differ not only for triaxial compression and extension but also for drained and undrained conditions. The experiment investigated shows the correctness of the frictional state theory in the triaxial condition.

  5. Pegasus Rocket Wing and PHYSX Glove Being Prepared for Stress Loads Testing

    Science.gov (United States)

    1997-01-01

    A technician adjusts the Pegasus Hypersonic Experiment (PHYSX) Project's Pegasus rocket wing with attached PHYSX glove before a loads-test at Scaled Composites, Inc., in Mojave, California, in January 1997. For the test, technicians slowly filled water bags beneath the wing to create the pressure, or 'wing-loading,' required to determine whether the wing could withstand its design limit for stress. The wing sits in a wooden triangular frame which serves as the test-rig, mounted to the floor atop the waterbags. PHYSX was launched aboard a Pegasus rocket on October 22, 1998. Pegasus is an air-launched space booster produced by Orbital Sciences Corporation and Hercules Aerospace Company (initially; later, Alliant Tech Systems) to provide small satellite users with a cost-effective, flexible, and reliable method for placing payloads into low earth orbit. Pegasus has been used to launch a number of satellites and the PHYSX experiment. That experiment consisted of a smooth glove installed on the first-stage delta wing of the Pegasus. The glove was used to gather data at speeds of up to Mach 8 and at altitudes approaching 200,000 feet. The flight took place on October 22, 1998. The PHYSX experiment focused on determining where boundary-layer transition occurs on the glove and on identifying the flow mechanism causing transition over the glove. Data from this flight-research effort included temperature, heat transfer, pressure measurements, airflow, and trajectory reconstruction. Hypersonic flight-research programs are an approach to validate design methods for hypersonic vehicles (those that fly more than five times the speed of sound, or Mach 5). Dryden Flight Research Center, Edwards, California, provided overall management of the glove experiment, glove design, and buildup. Dryden also was responsible for conducting the flight tests. Langley Research Center, Hampton, Virginia, was responsible for the design of the aerodynamic glove as well as development of sensor and

  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. 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).

  8. Cardiopulmonary stress testing in children and adults with congenital heart disease.

    Science.gov (United States)

    Miliaresis, Christa; Beker, Susan; Gewitz, Michael

    2014-01-01

    Cardiopulmonary exercise stress testing (CPET) is a vital tool used to assess patients with a history of congenital heart disease. There are several tests in the cardiologist's armamentarium that allow for assessment of cardiac anatomy and function. The majority of these tests are only performed with the body at rest and some even require sedation. Exercise stress testing is unique in allowing assessment of the hemodynamic status of a patient in motion. In addition to providing all the information obtained during an exercise stress test, such as heart rate, rhythm, ST-segment analysis, and blood pressure, the CPET provides critical metabolic information. Parameters such as VO2, oxygen pulse, and VE/VCO2 slope help to detail the patient's physiology in a dynamic state. Decisions can then be better made regarding follow-up plans, acceptable exercise recommendations, and future interventions, if necessary. It allows insight into the patient's exercise capacity and quality of life. Norms for both children and adults with many forms of congenital heart disease are now available allowing appropriate comparisons to be made. This review will discuss in detail the CPET and its application in congenital heart disease.

  9. Interaction between prenatal maternal stress and autonomic arousal in predicting conduct problems and psychopathic traits in children.

    Science.gov (United States)

    Gao, Yu; Huang, Yonglin; Li, Xiaobo

    2017-03-01

    Evidence has suggested that neurobiological deficits combine with psychosocial risk factors to impact on the development of antisocial behavior. The current study concentrated on the interplay of prenatal maternal stress and autonomic arousal in predicting antisocial behavior and psychopathic traits. Prenatal maternal stress was assessed by caregiver's retrospective report, and resting heart rate and respiratory sinus arrhythmia (RSA) were measured in 295 8- to 10-year-old children. Child and caregiver also reported on child's antisocial behavior and psychopathic traits. Higher prenatal maternal stress was associated with higher caregiver-reported antisocial and psychopathy scores, even after the concurrent measure of social adversity was controlled for. As expected, low heart rate and high RSA were associated with high antisocial and psychopathic traits. More importantly, significant interaction effects were found; prenatal stress was positively associated with multiple dimensions of psychopathic traits only on the conditions of low arousal (e.g., low heart rate or high RSA). Findings provide further support for a biosocial perspective of antisocial and psychopathic traits, and illustrate the importance of integrating biological with psychosocial measures to fully understand the etiology of behavioral problems.

  10. 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...

  11. 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

  12. Exercise-induced ischemic preconditioning detected by sequential exercise stress tests: a meta-analysis.

    Science.gov (United States)

    Lalonde, François; Poirier, Paul; Sylvestre, Marie-Pierre; Arvisais, Denis; Curnier, Daniel

    2015-01-01

    Exercise-induced ischemic preconditioning (IPC) can be assessed with the second exercise stress test during sequential testing. Exercise-induced IPC is defined as the time to 1 mm ST segment depression (STD), the rate-pressure product (RPP) at 1 mm STD, the maximal ST depression and the rate-pressure product at peak exercise. The purpose of this meta-analysis is to validate the parameters used to assess exercise-induced IPC in the scientific community. A literature search was performed using electronic database. The main key words were limited to human studies, which were (a) ischemic preconditioning, (b) warm-up phenomenon, and (c) exercise. Meta-analyses were performed on the study-specific mean difference between the clinical measures obtained in the two consecutive stress tests (second minus first test score). Random effect models were fitted with inverse variance weighting to provide greater weight to studies with larger sample size and more precise estimates. The search resulted in 309 articles of which 34 were included after revision (1053 patients). Results are: (a) time to 1 mm ST segment depression increased by 91 s (95% confidence interval (CI): 75-108), p ischemic preconditioning in sequential stress testing. The results of this first meta-analysis on the sequential stress test confirm what is presented in the literature by independent studies on exercise-induced ischemic preconditioning. From now on, the results could be used in further research to set standardized parameters to assess the phenomenon. © The European Society of Cardiology 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  13. 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

  14. 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

  15. 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

  16. 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.

  17. Multi-level slug tests in highly permeable formations: 2. Hydraulic conductivity identification, method verification, and field applications

    Science.gov (United States)

    Zlotnik, V.A.; McGuire, V.L.

    1998-01-01

    Using the developed theory and modified Springer-Gelhar (SG) model, an identification method is proposed for estimating hydraulic conductivity from multi-level slug tests. The computerized algorithm calculates hydraulic conductivity from both monotonic and oscillatory well responses obtained using a double-packer system. Field verification of the method was performed at a specially designed fully penetrating well of 0.1-m diameter with a 10-m screen in a sand and gravel alluvial aquifer (MSEA site, Shelton, Nebraska). During well installation, disturbed core samples were collected every 0.6 m using a split-spoon sampler. Vertical profiles of hydraulic conductivity were produced on the basis of grain-size analysis of the disturbed core samples. These results closely correlate with the vertical profile of horizontal hydraulic conductivity obtained by interpreting multi-level slug test responses using the modified SG model. The identification method was applied to interpret the response from 474 slug tests in 156 locations at the MSEA site. More than 60% of responses were oscillatory. The method produced a good match to experimental data for both oscillatory and monotonic responses using an automated curve matching procedure. The proposed method allowed us to drastically increase the efficiency of each well used for aquifer characterization and to process massive arrays of field data. Recommendations generalizing this experience to massive application of the proposed method are developed.Using the developed theory and modified Springer-Gelhar (SG) model, an identification method is proposed for estimating hydraulic conductivity from multi-level slug tests. The computerized algorithm calculates hydraulic conductivity from both monotonic and oscillatory well responses obtained using a double-packer system. Field verification of the method was performed at a specially designed fully penetrating well of 0.1-m diameter with a 10-m screen in a sand and gravel alluvial

  18. Reproduction and modulation of the stress response: an experimental test in the house sparrow

    Science.gov (United States)

    Lendvai, Ádám Zoltán; Giraudeau, Mathieu; Chastel, Olivier

    2006-01-01

    The stress response is highly variable among individuals, but the causes of this variation remain largely unknown. In response to stressors, vertebrates secrete elevated levels of glucocorticoids which enhance survival, but concurrently interfere with reproduction. We tested the hypothesis that individuals flexibly modulate their stress response with respect to the reproductive value of their brood in free-living house sparrows (Passer domesticus). We experimentally increased or decreased clutch size during the nestling period and found that parents tending enlarged clutches responded less strongly to a stressor than those tending reduced clutches. In addition, we examined whether individuals responded less strongly to a stressor as the breeding season progressed and future reproductive opportunities declined. We found that the stress response decreased with breeding date during the birds' first breeding attempt, but it remained constant during their second breeding attempt. Within-individual variability in the stress response was related to the brood size manipulations the birds received in their two consecutive breeding attempts. These results provide the first experimental support for the hypothesis that individuals actively modulate their stress response with respect to the value of current reproduction. PMID:17164203

  19. [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.

  20. Clinical evaluation and stress test have limited value in the diagnosis of in-stent restenosis.

    Science.gov (United States)

    Andersen, Karl; Steinthórsdóttir, Sandra Dís; Haraldsdottir, Sigurdis; Gudnason, Thorarinn

    2009-12-01

    In-stent restenosis (ISR) is the main limitation of percutaneous coronary interventions (PCI), occurring in approximately 25% of cases. Although frequently asymptomatic, many PCI patients present with recurrent symptoms of chest pain at follow-up raising a clinical suspicion of ISR. The diagnosis of ISR can be challenging in these patients and difficult to rule out without repeat coronary angiography. We prospectively investigated the diagnostic accuracy of clinical evaluation and exercise stress testing to detect ISR as compared to coronary angiography, in a consecutive, unselected cohort of PCI patients. We studied 91 patients with a total of 143 stents. Clinical evaluation predicted ISR to be likely in 19% of cases and the exercise test was positive in 29%. The binary restenosis rate was 21%. Clinical evaluation had a positive predictive value of 29% and accuracy of 71%, while exercise stress testing had a positive predictive value of 19% and accuracy of 65%. In conclusion, we found the diagnostic accuracy of clinical evaluation to be low and not significantly improved by exercise stress testing when evaluating PCI patients for ISR.

  1. Possibilities of applying pharmacological stress testing in assessment of heart functional capacity in dogs

    Directory of Open Access Journals (Sweden)

    Kosić-Spasojević Ljubica

    2010-01-01

    Full Text Available Systolic and diastolic heart functions, evaluated using echocardiography, do not reflect the functional capacity of the patient and they cannot explain the occurrence of symptoms during a certain degree of activity. Evaluation of the functional capacity is an integral part of cardiological examinations in human medicine. Functional examinations of the heart can be carried out using the body burden test or pharmacologically. Investigations carried out so far into canine cardiology have not contributed to the clinical implementation of functional heart examinations in dogs. Pharmacological stress testing is an optimal way to perform a functional heart examination in dogs. Since it reflects the effects of moderate physical activity, dobutamine has been recommended as the medicine of choice for provoking a pharmacological stress test. This work presents a review of the results of the most important investigations, as well as our own investigations, of the application of the dobutamine stress test (DST in dogs, and the problems in investigations so far have been considered and future directions for DST investigations pointed out. .

  2. Evaluation of a dentoalveolar model for testing mouthguards: stress and strain analyses.

    Science.gov (United States)

    Verissimo, Crisnicaw; Costa, Paulo Victor Moura; Santos-Filho, Paulo César Freitas; Fernandes-Neto, Alfredo Júlio; Tantbirojn, Daranee; Versluis, Antheunis; Soares, Carlos José

    2016-02-01

    Custom-fitted mouthguards are devices used to decrease the likelihood of dental trauma. The aim of this study was to develop an experimental bovine dentoalveolar model with periodontal ligament to evaluate mouthguard shock absorption, and impact strain and stress behavior. A pendulum impact device was developed to perform the impact tests with two different impact materials (steel ball and baseball). Five bovine jaws were selected with standard age and dimensions. Six-mm mouthguards were made for the impact tests. The jaws were fixed in a pendulum device and impacts were performed from 90, 60, and 45° angles, with and without mouthguard. Strain gauges were attached at the palatal surface of the impacted tooth. The strain and shock absorption of the mouthguards was calculated and data were analyzed with 3-way anova and Tukey's test (α = 0.05). Two-dimensional finite element models were created based on the cross-section of the bovine dentoalveolar model used in the experiment. A nonlinear dynamic impact analysis was performed to evaluate the strain and stress distributions. Without mouthguards, the increase in impact angulation significantly increased strains and stresses. Mouthguards reduced strain and stress values. Impact velocity, impact object (steel ball or baseball), and mouthguard presence affected the impact stresses and strains in a bovine dentoalveolar model. Experimental strain measurements and finite element models predicted similar behavior; therefore, both methodologies are suitable for evaluating the biomechanical performance of mouthguards. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Analysis of Stress in Steel and Concrete in Cfst Push-Out Test Samples

    Science.gov (United States)

    Grzeszykowski, Bartosz; Szadkowska, Magdalena; Szmigiera, Elżbieta

    2017-09-01

    The paper presents the analysis of stress in steel and concrete in CFST composite elements subjected to push-out tests. Two analytical models of stress distribution are presented. The bond at the interface between steel and concrete in the initial phase of the push-out test is provided by the adhesion. Until the force reach a certain value, the slip between both materials does not occur or it is negligibly small, what ensures full composite action of the specimen. In the first analytical model the full bond between both materials was assumed. This model allows to estimate value of the force for which the local loss of adhesion in given cross section begins. In the second model it was assumed that the bond stress distribution is constant along the shear transfer length of the specimen. Based on that the formulas for triangle distribution of stress in steel and concrete for the maximum push-out force were derived and compared with the experimental results. Both models can be used to better understand the mechanisms of interaction between steel and concrete in composite steel-concrete columns.

  4. Analysis of Stress in Steel and Concrete in Cfst Push-Out Test Samples

    Directory of Open Access Journals (Sweden)

    Grzeszykowski Bartosz

    2017-09-01

    Full Text Available The paper presents the analysis of stress in steel and concrete in CFST composite elements subjected to push-out tests. Two analytical models of stress distribution are presented. The bond at the interface between steel and concrete in the initial phase of the push-out test is provided by the adhesion. Until the force reach a certain value, the slip between both materials does not occur or it is negligibly small, what ensures full composite action of the specimen. In the first analytical model the full bond between both materials was assumed. This model allows to estimate value of the force for which the local loss of adhesion in given cross section begins. In the second model it was assumed that the bond stress distribution is constant along the shear transfer length of the specimen. Based on that the formulas for triangle distribution of stress in steel and concrete for the maximum push-out force were derived and compared with the experimental results. Both models can be used to better understand the mechanisms of interaction between steel and concrete in composite steel-concrete columns.

  5. Water stress inhibits hydraulic conductance and leaf growth in rice seedlings but not the transport of water via mercury-sensitive water channels in the root

    Science.gov (United States)

    Lu; Neumann

    1999-05-01

    The mechanisms by which moderate water stress (adding polyethylene glycol 6000 to the root medium) induces a sustained inhibition of growth in emerging first leaves of intact rice (Oryza sativa) seedlings was investigated under growth-chamber conditions. Early (24 h) inhibition of leaf growth was not related to changes in root size or in osmotic potential gradients and cell wall-yielding characteristics in the leaf-expansion zone of stressed seedlings. However, reductions in root-to-leaf hydraulic conductance (L) were measured in two rice cultivars after 4 or 24 h at various levels of water stress, and these reductions correlated well with the inhibition of leaf growth. We assayed L by a psychrometric method and, in intact seedlings, by a novel osmotic-jump method. The addition of 0.5 mM HgCl2 to the root medium to inhibit water transport through Hg-sensitive water channels in the roots did not inhibit leaf growth in unstressed seedlings. However, both leaf growth and L were additionally reduced (by 49% and 43%, respectively) within minutes of adding HgCl2 to roots of water-stressed seedlings. Water stress therefore appeared to increase the transport of water via Hg-sensitive water channels. Other mechanisms were apparently involved in inhibiting overall L and leaf growth.

  6. Changes in root hydraulic conductivity facilitate the overall hydraulic response of rice (Oryza sativa L.) cultivars to salt and osmotic stress.

    Science.gov (United States)

    Meng, Delong; Fricke, Wieland

    2017-04-01

    The aim of the present work was to assess the significance of changes in root AQP gene expression and hydraulic conductivity (Lp) in the regulation of water balance in two hydroponically-grown rice cultivars (Azucena, Bala) which differ in root morphology, stomatal regulation and aquaporin (AQP) isoform expression. Plants were exposed to NaCl (25 mM, 50 mM) and osmotic stress (5%, 10% PEG6000). Root Lp was determined for exuding root systems (osmotic forces driving water uptake; 'exudation Lp') and transpiring plants (hydrostatic forces dominating; 'transpiration-Lp'). Gene expression was analysed by qPCR. Stress treatments caused a consistent and significant decrease in plant growth, transpirational water loss, stomatal conductance, shoot-to-root surface area ratio and root Lp. Comparison of exudation-with transpiration-Lp supported a significant contribution of AQP-facilitated water flow to root water uptake. Changes in root Lp in response to treatments were correlated much stronger with root morphological characteristics, such as the number of main and lateral roots, surface area ratio of root to shoot and plant transpiration rate than with AQP gene expression. Changes in root Lp, involving AQP function, form an integral part of the plant hydraulic response to stress and facilitate changes in the root-to-shoot surface area ratio, transpiration and stomatal conductance. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. 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)

  8. 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.

  9. 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...

  10. 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.

  11. Effect of Jig Design and Assessment of Stress Distribution in Testing Metal-Ceramic Adhesion.

    Science.gov (United States)

    Özcan, Mutlu; Kojima, Alberto Noriyuki; Nishioka, Renato Sussumu; Mesquita, Alfredo Mikail Melo; Bottino, Marco Antonio; Filho, Gilberto Duarte

    2016-12-01

    In testing adhesion using shear bond test, a combination of shear and tensile forces occur at the interface, resulting in complex stresses. The jig designs used for this kind of test show variations in published studies, complicating direct comparison between studies. This study evaluated the effect of different jig designs on metal-ceramic bond strength and assessed the stress distribution at the interface using finite element analysis (FEA). Metal-ceramic (Metal: Ni-Cr, Wiron 99, Bego; Ceramic: Vita Omega 900, Vita) specimens (N = 36) (diameter: 4 mm, veneer thickness: 4 mm; base diameter: 5 mm, thickness: 1 mm) were fabricated and randomly divided into three groups (n = 12 per group) to be tested using one of the following jig designs: (a) chisel (CH) (ISO 11405), (b) steel strip (SS), (c) piston (PI). Metal-ceramic interfaces were loaded under shear until debonding in a universal testing machine (0.5 mm/min). Failure types were evaluated using scanning electron microscopy (SEM). FEA was used to study the stress distribution using different jigs. Metal-ceramic bond strength data (MPa) were analyzed using ANOVA and Tukey's tests (α = 0.05). The jig type significantly affected the bond results (p = 0.0001). PI type of jig presented the highest results (MPa) (p Metal-ceramic bond strength was affected by the jig design. Accordingly, the results of in vitro studies on metal-ceramic adhesion should be evaluated with caution. When adhesion of ceramic materials to metals is evaluated in in vitro studies, it should be noted that the loading jig type affects the results. Clinical observations should report on the location and type of ceramic fractures in metal-ceramic reconstructions so that the most relevant test method can be identified. © 2015 by the American College of Prosthodontists.

  12. 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

  13. A stress test on 235U(n, f) in adjustment with HCI and HMI benchmarks

    Science.gov (United States)

    Wu, Haicheng; Qin, Yingcan; Salvatores, Massimo

    2017-09-01

    To understand how compensation errors occur in a nuclear data adjustment mostly devoted to U-Pu fuelled fast critical experiments and with only limited information on U-235 data, a stress test on 235U(n,f) was suggested, using critical benchmarks sensitive to 235U(n,f) in 1˜ 10 keV region. The adjustment benchmark exercise with 20 integral data suggested by the NEA WPEC/SG33 was used as the reference, where practically only one experiment did give information on U-235 data. The keff of HCI4.1 and HCI6.2 experimental benchmarks were used as the 21st and 22nd integral data separately to perform stress tests. The adjusted integral values and cross sections based on 20, 21 and 22 integral data using the same nuclear data and covariance data sets were compared. The results confirm that compensation errors can be created by missing essential constraints.

  14. 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.

  15. The Stress Analysis and Tests on the Hinge Beam of the Diamond Synthesis Cubic Press

    Directory of Open Access Journals (Sweden)

    Ma Liang

    2016-01-01

    Full Text Available To deal with the problem of the lug fractures of hinge beam caused by the fatigue and overload during the operation of the cubic press, the analysis methods of finite element are applied to the analysis of the internal stress distributions of the hinge beam. The simulation results show that the internal stress of the hinge beam mainly concentrates on the upper surface of the lug roots connecting the outer cylinder with the both lugs. According to the data of simulation and analysis as well as the actual fracture situations, considering the strain-test methods we have designed the schemes of testing the strain on the lugs of hinge beam. And the strain measurements of the lugs are completed by the repeated loading experiments. Comparing the data of simulation and analysis with the measured data has verified their consistency. It also confirms the model established by the simulation and analysis is reasonable and accurate at the same time.

  16. 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.

  17. 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.

  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 stenosis. Patients having atresia of the pulmonary artery were excluded from the study. 24 of the patients had previously undergone reconstruction of the right ventricular outflow tract (RVOT) with preserving the pulmonary valvar annulus (group N), whilst the remaining 12 patients had undergone transannular enlargement of RVOT with a patch (group T). Preservation of the pulmonary valvar annulus was determined when the intra-operative measurement of diameter of the pulmonary valvar annulus showed values greater than 90% of normal. In both groups, the isoproterenol infusion increased the right to left ventricular peak pressure (RVP/LVP) ratio, pressure gradient between the right ventricle and main pulmonary artery (RV-mPAP), and pressure gradient between the main pulmonary artery and peripheral pulmonary artery (m-pPAP). These values were significantly higher than those measured at rest. When comparisons were made between groups, RV-mPAP of group N was significantly higher than that of group T, both at rest and during stress test. By contrast, m-pPAP of group T was significantly higher than that of group N, both at rest and during stress test. Although no significant difference was found between the groups in RVP/LVP at rest and during stress test, RVP/LVP of both groups increased to the level of more than 0.6 after the isoproterenol infusion. These results led us to conclude that preservation of the pulmonary valvar annulus was better to be applied only to the patients who fulfilled our criterions. Additionally, in the setting of patch reconstruction of the pulmonary artery, every effort should be made so as not to leave the residual stenosis of the peripheral pulmonary artery.

  19. Conclusion of the EU nuclear stress test. Comments on results and interpretations

    International Nuclear Information System (INIS)

    Anon.

    2013-01-01

    On 4th October 2012 the European Commission had published their interpretation of the results of the EU Nuclear Stress Test for the nuclear power stations in the individual EU Member States and in Switzerland and the Ukraine, the neighbouring states involved. According to this, the safety standards in nuclear power stations are generally high. None of the plants inspected revealed shortcomings in design, which would have required the service to be interrupted or the decommissioning of the plant. This means inter alia that there are no shortcomings in design in Europe like those in Fukushima Daiichi in Japan. To summarise, it can be stated that, in the opinion of the country-specific peer assessments, or peer reviews, the respective national investigations and the EU Stress Test have demonstrated that (a) the safety standards in all the European nuclear power stations are generally high and deactivation is not necessary, (b) in all plants the design principles (inter alia seismic intensity, level of floodwater, external pressures) have been correctly defined for each location (cause of the disaster at Fukushima), (c) evidence for the management of all the respective requirements do not merely exist, but are also correct, (d) furthermore, the plants demonstrate to a varying extent additional reserves or robustness as regards incidents which exceed the technical specifications. There is no question of the 'severe shortcomings' claimed by the daily newspaper, Die Welt, a few days before the publication of the EU Stress Test results. What is more relevant is that the Commission Report on the EU Stress Test made only two recommendations for the German nuclear power stations. (orig.)

  20. Toxic stress prioritizes and imbalances stem cell differentiation: implications for new biomarkers and in vitro toxicology tests.

    Science.gov (United States)

    Rappolee, Daniel A; Xie, Yufen; Slater, Jill A; Zhou, Sichang; Puscheck, Elizabeth E

    2012-02-01

    This hypothesis and review introduces rules of stem cell stress responses that provide biomarkers and alternative testing that replaces or reduces gestational tests using whole animals. These rules for the stress responses of cultured stem cells validate the organismal strategy of the stress response and show that it emulates what must happen if the conceptus implants during a response to stress in vivo. Specifically there is a profound threshold during a stress dose response where stem cell accumulation is significantly reduced. Below this threshold stress enzymes manage the stress response by converting anabolic to catabolic processes and by suppressing apoptosis, without affecting differentiation. However above this threshold the stem cell survival response converts to an organismal survival response where stress enzymes switch to new substrates and mediate loss of potency factors, gain of early essential differentiated lineages, and suppression of later essential lineages. Stressed stem cells 'compensate' for lower accumulation rates by differentiating a higher fraction of cells, and the organismal survival response further enhances adaptation by prioritizing the differentiation of early essential lineages. Thus compensatory and prioritized differentiation and the sets of markers produced are part of a response of cultured embryos and stem cells that emulate what must happen during implantation of a stressed gestation. Knowledge of these markers and use of stressed stem cell assays in culture should replace or reduce the number of animals needed for developmental toxicity and should produce biomarkers for stressed development in vitro and in vivo.

  1. Over-pressure test on BARCOM pre-stressed concrete containment

    Energy Technology Data Exchange (ETDEWEB)

    Parmar, R.M.; Singh, Tarvinder; Thangamani, I.; Trivedi, Neha; Singh, Ram Kumar, E-mail: rksingh@barc.gov.in

    2014-04-01

    Bhabha Atomic Research Centre (BARC), Trombay has organized an International Round Robin Analysis program to carry out the ultimate load capacity assessment of BARC Containment (BARCOM) test model. The test model located in BARC facilities Tarapur; is a 1:4 scale representation of 540 MWe Pressurized Heavy Water Reactor (PHWR) pre-stressed concrete inner containment structure of Tarapur Atomic Power Station (TAPS) unit 3 and 4. There are a large number of sensors installed in BARCOM that include vibratory wire strain gauges of embedded and spot-welded type, surface mounted electrical resistance strain gauges, dial gauges, earth pressure cells, tilt meters and high resolution digital camera systems for structural response, crack monitoring and fracture parameter measurement to evaluate the local and global behavior of the containment test model. The model has been tested pneumatically during the low pressure tests (LPTs) followed by proof test (PT) and integrated leakage rate test (ILRT) during commissioning. Further the over pressure test (OPT) has been carried out to establish the failure mode of BARCOM Test-Model. The over-pressure test will be completed shortly to reach the functional failure of the test model. Pre-test evaluation of BARCOM was carried out with the results obtained from the registered international round robin participants in January 2009 followed by the post-test assessment in February 2011. The test results along with the various failure modes related to the structural members – concrete, rebars and tendons identified in terms of prescribed milestones are presented in this paper along with the comparison of the pre-test predictions submitted by the registered participants of the Round Robin Analysis for BARCOM test model.

  2. Test Results of a Nb3Sn Wind/React ''Stress-Managed'' Block Dipole

    International Nuclear Information System (INIS)

    McInturff, A.; Bish, P.; Blackburn, R.; Diaczenko, N.; Elliott, T.; Hafalia Jr., R.; Henchel, W.; Jaisle, A.; Lau, W.; Lietzke, A.; McIntyre, P.; Noyes, P.; Nyman, M.; Sattarov, A.; Sattarov, A.

    2006-01-01

    A second phase of a highfield dipole technology development has been tested. A Nb3Sn block-coil model dipole was fabricated, using magnetic mirror geometry and wind/react coil technology. The primary objective of this phase was to make a first experimental test of the stress-management strategy pioneered at Texas A and M. In this strategy a high-strength support matrix is integrated with the windings to intercept Lorentz stress from the inner winding so that it does not accumulate in the outer winding. The magnet attained a field that was consistent with short sample limit on the first quench; there was no training. The decoupling of Lorentz stress between inner and outer windings was validated. In ramp rate studies the magnet exhibited a remarkable robustness in rapid ramping operation. It reached 85 percent of short sample(ss) current even while ramping 2-3 T/s. This robustness is attributed to the orientation of the Rutherford cables parallel to the field in the windings, instead of the transverse orientation that characterizes common dipole designs. Test results are presented and the next development phase plans are discussed

  3. 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

  4. 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.

  5. Design, simulation and test for double focusing Si monochromator of neutron residual stress diffractometer

    International Nuclear Information System (INIS)

    Hu Rui; Liu Yuntao; Wang Wei; Liu Zhongxiao; Li Junhong; Gao Jianbo; Wang Hongli; Chen Dongfeng

    2015-01-01

    The double focusing Si monochromator was designed, simulated and tested for the neutron residual stress diffractometer on China Advanced Research Reactor. The optimal vertical curvature and the optimal thickness of Si wafers were obtained by SIMRES simulation program. In addition, the figure of merit in dependence on the scattering angle, monochromator horizontal curvature and wavelength was also determined by this program. The neutron beam test results indicate that the intensity of neutron increases by 15 times by using double focusing Si monochromator in comparison with Cu monochromator. (authors)

  6. 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

  7. Laboratory and Field Test of Movable Conduction-Cooled High-Temperature SMES for Power System Stability Enhancement

    DEFF Research Database (Denmark)

    Fang, Jiakun; Wen, J.; Wang, S.

    2013-01-01

    ’ effectiveness on improvements of system voltage stability and on the oscillation damping. Test results indicate that the SMES system has the features of fast response and four-quadrant power operation. The accessories for the movability of the SEMS system are well designed. The system is feasible to be used...... in power systems.......This paper introduces the first movable conduction-cooled high temperature superconducting magnetic energy storage (SMES) system developed in China. The SMES is rated at 380 V / 35 kJ / 7 kW, consisting of the high temperature magnet confined in a dewar, the cryogenic unit, the converter...

  8. Diagnostic value of exercise stress testing, dipyridamole stress-echocardiography and perfusion stress-scintigraphy for identification of coronary artery disease in women

    International Nuclear Information System (INIS)

    Debnath, S.; Tyrnovska-Kydreva, R.; Khalacheva, S.; Radoslavova, R.; Stoyanova, N.; Draganov, T.; Elenkova, A.; Garcheva, M.; Shejretova, E.

    1995-01-01

    To compare the value of exercise stress testing (EST), dipyridamole stress echocardiography and 99m Tc-methoxy-isobutyl-isonitrile (MIBI)-planer scintigraphy, 75 female patients with angina pectoris who underwent coronary angiography were studied. Significant (≥50% stenosis) coronary artery disease (CAD) was present in 38 of the patients. EST was performed in all of the patients but dipyridamole echocardiography and MIBI-planer scintigraphy - in 36 of them (22 with and 14 without CAD). Compared with dipyridamole echocardiography, EST and MIBI-planer scintigraphy had a significantly higher sensitivity (74% vs 45%, p<0.01 and 82% vs 45%, p<0.01, respectively). There was no significant difference in sensitivity between EST and MIBI-planer scintigraphy. Dipyridamole echocardiography and MIBI-planer scintigraphy showed a higher specificity than EST (93% vs 54%, p<0.01 and 93% vs 54%, p<0.01, respectively). Diagnostic accuracy of MIBI-planer scintigraphy was higher than that of dipyridamole echocardiography and EST (86% vs 64%, p<0.05 and 86 vs 64%, p<0.01, respectively). Thus, MIBI-planer scintigraphy appears to be superior to EST and dipyridamole echocardiography for the evaluation of CAD in symptomatic women. 20 refs., 2 tabs. (author)

  9. 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.

  10. Database dictionary for the results of groundwater tracer tests using tritiated water, conducted at the Oak Ridge National Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, B.K. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Civil Engineering; Huff, D.D. [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.

    1997-05-01

    In 1977, the United States Geological Survey (USGS) conducted two tracer tests at the Oak Ridge National Laboratory (ORNL) using tritiated water to study the relative importance of bedding-plane openings on shallow groundwater flow. Through a cooperative agreement between the USGS and the US Department of Energy (DOE), the data were made available to researchers at the Oak Ridge National Laboratory (ORNL), who organized the data into a data management format. The results of these groundwater tracer tests have been compiled into a collection of four SAS data sets. This report documents these SAS data sets, including their structure, methodology, and content. The SAS data sets include information on precipitation, tritium, water levels, and well construction for wells at or near ORNL radioactive waste burial grounds 4, 5, and 6.

  11. 40 CFR 63.9620 - On which units and by what date must I conduct performance tests or other initial compliance...

    Science.gov (United States)

    2010-07-01

    ... units and by what date must I conduct performance tests or other initial compliance demonstrations? (a... similar emission units together and conduct an initial compliance test on one representative emission unit... meet the criteria in paragraph (f) of this section. If you decide to test representative emission units...

  12. Value of stress ultrasound for the diagnosis of chronic ankle instability compared to manual anterior drawer test, stress radiography, magnetic resonance imaging, and arthroscopy.

    Science.gov (United States)

    Cho, Jae Ho; Lee, Doo Hyung; Song, Hyung Keun; Bang, Joon Young; Lee, Kyung Tai; Park, Young Uk

    2016-04-01

    Clinicians frequently diagnose chronic ankle instability using the manual anterior drawer test and stress radiography. However, both examinations can yield incorrect results and do not reveal the extent of ankle instability. Stress ultrasound has been reported to be a new diagnostic tool for the diagnosis of chronic ankle instability. The purpose of this study was to assess the diagnostic value of stress ultrasound for chronic ankle instability compared to the manual anterior drawer test, stress radiography, magnetic resonance imaging (MRI), and arthroscopy. Twenty-eight consecutive patients who underwent ankle arthroscopy and subsequent modified Broström repair for treatment of chronic ankle instability were included. The arthroscopic findings were used as the reference standard. A standardized physical examination (manual anterior drawer test), stress radiography, MRI, and stress ultrasound were performed to assess the anterior talofibular ligament (ATFL) prior to operation. Ultrasound images were taken in the resting position and the maximal anterior drawer position. Grade 3 lateral instability was verified arthroscopically in all 28 cases with a clinical diagnosis (100%). Twenty-two cases showed grade III instability on the manual anterior drawer test (78.6%). Twenty-four cases displayed anterior translation exceeding 5 mm on stress radiography (86%), and talar tilt angle exceeded 15° in three cases (11 %). Nineteen cases displayed a partial chronic tear (change in thickness or signal intensity), and nine cases displayed complete tear on MRI (100%). Lax and wavy ATFL was evident on stress ultrasound in all cases (100 %). The mean value of the ATFL length was 2.8 ± 0.3 cm for the stressed condition and 2.1 ± 0.2 cm for the resting condition (p radiography. III.

  13. Manufacturing method for intragranular stress corrosion cracking-induced test specimen for stainless steel pipeline

    International Nuclear Information System (INIS)

    Futagawa, Kiyoshi.

    1994-01-01

    In a manufacturing step for intragranular stress corrosion cracking-induced for stainless steel pipelines, pipe are abutted against with each other and welded, and a heat affected portion is applied with a sensitizing heat treatment. Further, a crevice jig is attached near the heat affected portion at the inner surface of the pipe and kept in a chlorine ion added water under high temperature and high pressure at a predetermined period of time. If tap water is used instead of purified water for C.P.T. test in a step of forming sample of IGSCC (intergranular stress corrosion cracking), since the chlorine ion concentration in the tap water is relatively high, TGSCC (intragranular stress corrosion crackings caused in all of the samples. A heat input and an interlayer temperature are determined for the material of stainless pipe having a carbon content of more than 0.05% so that the welding residual stress on the inner surface is applied as tension. The condition for the heat treatment is determined as, for example, 500degC x 24hr, and the samples are kept under water at high temperature and high pressure applied with chlorine ions for 500 to 200hours. As a result, since samples of TGSCC can be formed by utilizing the manufacturing step for IGSCC, there is no requirement for providing devices for applying environmental factors separately. (N.H.)

  14. NRI experimental facility for the testing of irradiation assisted stress corrosion cracking

    International Nuclear Information System (INIS)

    Ruscak, M.; Chvatal, P.; Zamboch, M.

    1998-01-01

    IASCC influencing reactor internals of both BWR and PWR reactors is a complex phenomenon covering influences of material structure, neutron fluence, neutron flux, chemistry of environment, gamma radiation and mechanical stress. To evaluate such degradation, tests should be performed under conditions similar to those in real structure. Nuclear Research Institute has built several experimental facilities in order to be able to test IASCC degradation of materials. Basically, reactor water loops, both PWR and BWR, could be used to model environmental conditions including gamma and neutron irradiation. Pre-irradiation can be done in irradiation channels under well controlled temperature conditions. During the experiment, in-pile conditions can be compared with those out of pile. It enables to clarify pure influence of irradiation. For testing of irradiated specimens, hot cell facility has been developed for slow strain rate tests. The paper will show all above mentioned facilities as well as some of the results observed with them. (author)

  15. Some important considerations in the development of stress corrosion cracking test methods.

    Science.gov (United States)

    Wei, R. P.; Novak, S. R.; Williams, D. P.

    1972-01-01

    Discussion of some of the precaution needs the development of fracture-mechanics based test methods for studying stress corrosion cracking involves. Following a review of pertinent analytical fracture mechanics considerations and of basic test methods, the implications for test corrosion cracking studies of the time-to-failure determining kinetics of crack growth and life are examined. It is shown that the basic assumption of the linear-elastic fracture mechanics analyses must be clearly recognized and satisfied in experimentation and that the effects of incubation and nonsteady-state crack growth must also be properly taken into account in determining the crack growth kinetics, if valid data are to be obtained from fracture-mechanics based test methods.

  16. Stress Testing of an Artificial Pancreas System With Pizza and Exercise Leads to Improvements in the System's Fuzzy Logic Controller.

    Science.gov (United States)

    Mauseth, Richard; Lord, Sandra M; Hirsch, Irl B; Kircher, Robert C; Matheson, Don P; Greenbaum, Carla J

    2015-09-14

    Under controlled conditions, the Dose Safety artificial pancreas (AP) system controller, which utilizes "fuzzy logic" (FL) methodology to calculate and deliver appropriate insulin dosages based on changes in blood glucose, successfully managed glycemic excursions. The aim of this study was to show whether stressing the system with pizza (high carbohydrate/high fat) meals and exercise would reveal deficits in the performance of the Dose Safety FL controller (FLC) and lead to improvements in the dosing matrix. Ten subjects with type 1 diabetes (T1D) were enrolled and participated in 30 studies (17 meal, 13 exercise) using 2 versions of the FLC. After conducting 13 studies with the first version (FLC v2.0), interim results were evaluated and the FLC insulin-dosing matrix was modified to create a new controller version (FLC v2.1) that was validated through regression testing using v2.0 CGM datasets prior to its use in clinical studies. The subsequent 17 studies were performed using FLC v2.1. Use of FLC v2.1 vs FLC v2.0 in the pizza meal tests showed improvements in mean blood glucose (205 mg/dL vs 232 mg/dL, P = .04). FLC v2.1 versus FLC v2.0 in exercise tests showed improvements in mean blood glucose (146 mg/dL vs 201 mg/dL, P = .004), percentage time spent >180 mg/dL (19.3% vs 46.7%, P = .001), and percentage time spent 70-180 mg/dL (80.0% vs 53.3%, P = .002). Stress testing the AP system revealed deficits in the FLC performance, which led to adjustments to the dosing matrix followed by improved FLC performance when retested. © 2015 Diabetes Technology Society.

  17. Thermal Stress Analysis of a Continuous and Pulsed End-Pumped Nd:YAG Rod Crystal Using Non-Classic Conduction Heat Transfer Theory

    Science.gov (United States)

    Mojahedi, Mahdi; Shekoohinejad, Hamidreza

    2018-02-01

    In this paper, temperature distribution in the continuous and pulsed end-pumped Nd:YAG rod crystal is determined using nonclassical and classical heat conduction theories. In order to find the temperature distribution in crystal, heat transfer differential equations of crystal with consideration of boundary conditions are derived based on non-Fourier's model and temperature distribution of the crystal is achieved by an analytical method. Then, by transferring non-Fourier differential equations to matrix equations, using finite element method, temperature and stress of every point of crystal are calculated in the time domain. According to the results, a comparison between classical and nonclassical theories is represented to investigate rupture power values. In continuous end pumping with equal input powers, non-Fourier theory predicts greater temperature and stress compared to Fourier theory. It also shows that with an increase in relaxation time, crystal rupture power decreases. Despite of these results, in single rectangular pulsed end-pumping condition, with an equal input power, Fourier theory indicates higher temperature and stress rather than non-Fourier theory. It is also observed that, when the relaxation time increases, maximum amounts of temperature and stress decrease.

  18. Re-evaluation of the interrelationships among the behavioral tests in rats exposed to chronic unpredictable mild stress.

    Directory of Open Access Journals (Sweden)

    Congli Hu

    Full Text Available The chronic unpredictable mild stress model of depression has been widely used as an experimental tool to investigate human psychopathology. Our objective was to provide an update on the validity and reliability of the chronic unpredictable mild stress model, by analyzing the interrelationships among the indexes using stepwise discriminant analysis and Pearson correlation coefficient to examine the possible combinations. We evaluated the depressive rats in both the presence and the absence of chronic unpredictable mild stress, using weight change, percentage of sucrose preference, coat state, splash test, open-field test, elevated plus-maze test, forced swimming test, and Morris water maze test. The results showed that 6-week-long chronic unpredictable mild stress produces significant depression and anxiety-like behavior. The combination of body weight change, percentage of sucrose preference, coat state score, open-field score, grooming latency of splash test, immobility time in force swimming test, and platform crossing in the Morris water maze test can effectively discriminate between normal and chronic unpredictable mild stress rats. Strong interrelationships were noted among these indexes in both open-field test and elevated plus-maze test. In conclusion, there might be certain criteria for the combination of behavioral endpoints, which is advantageous to more effectively and reliably assess the chronic unpredictable mild stress induced depression model.

  19. Vestibular evoked myogenic potential testing for the diagnosis of conductive hearing loss: survey of pediatric otolaryngologists' knowledge and beliefs.

    Science.gov (United States)

    Dargie, Jenna M; Zhou, Guangwei; Dornan, Briana K; Whittemore, Kenneth R

    2014-11-01

    To assess physicians' knowledge and beliefs regarding vestibular evoked myogenic potential (VEMP) testing in children. A survey was delivered via email in html format to 1069 members of the American Academy of Otolaryngology--Head and Neck Surgery who identified as pediatric otolaryngologists. Study data were collected and managed using the Research Electronic Data Capture (REDCap) tools. 443 (41.4%) physicians opened the email. 190 (42.9% of opens) initiated the survey, of which 117 (61.9%) fully completed the survey of the physicians who responded to a question regarding knowledge of VEMP, 16% of respondents had never heard of the test. 16% of participants would use it in the setting of diagnosing pediatric conductive hearing loss. Responses regarding the youngest age at which VEMP is possible ranged from younger than 6 months through greater than 13 years of age. Beliefs regarding utility and reliability of VEMP varied, with 'unsure' as the most frequent response. Additionally, only 26% of pediatric otolaryngologists indicated some access to the test. The knowledge and availability of VEMP testing in the pediatric otolaryngology community varies widely. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. 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

    2009-05-01

    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 maternal acculturation and adolescents' conduct problems could be explained by differences in mothers' reliance on monitoring and harsh discipline. In addition, guided by segmented assimilation theory, measures of neighborhood disadvantage were expected not only to be related to differences in parenting, but also to moderate the effects of maternal acculturation on parenting. Results indicated that increased maternal acculturation was related to higher levels of maternal monitoring and lower levels of harsh discipline, which, in turn, were related to lower levels of adolescents' conduct problems. Hierarchical linear modeling results revealed that neighborhood disadvantage was related to lower levels of maternal monitoring. However, neighborhood disadvantage did not moderate the link between maternal acculturation and parenting practices.

  1. Work-related stress is associated with impaired neuropsychological test performance: a clinical cross-sectional study.

    Science.gov (United States)

    Eskildsen, Anita; Andersen, Lars Peter; Pedersen, Anders Degn; Vandborg, Sanne Kjær; Andersen, Johan Hviid

    2015-01-01

    Patients on sick leave due to work-related stress often complain about impaired concentration and memory. However, it is undetermined how widespread these impairments are, and which cognitive domains are most long-term stress sensitive. Previous studies show inconsistent results and are difficult to synthesize. The primary aim of this study was to examine whether patients with work-related stress complaints have cognitive impairments compared to a matched control group without stress. Our secondary aim was to examine whether the level of self-reported perceived stress is associated with neuropsychological test performance. We used a broad neuropsychological test battery to assess 59 outpatients with work-related stress complaints (without major depression) and 59 healthy controls. We matched the patients and controls pairwise by sex, age and educational level. Compared to controls, patients generally showed mildly reduced performance across all the measured domains of the neuropsychological test battery. However, only three comparisons reached statistical significance (p working memory. There were no statistical significant associations between self-reported perceived stress level and neuropsychological test performance. In conclusion, we recommend that cognitive functions should be considered when evaluating patients with work-related stress complaints, especially when given advice regarding return to work. Since this study had a cross-sectional design, it is still uncertain whether the impairments are permanent. Further study is required to establish causal links between work-related stress and cognitive deficits.

  2. Stress !!!

    OpenAIRE

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten. Opvallend is dat mannelijke studenten uit Twente zich veel minder druk lijken te maken over hun studie. Onder vrouwen ligt de stress juist erg hoog ten opzichte van het landelijk gemiddelde.

  3. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  4. Laterality as an indicator of emotional stress in ewes and lambs during a separation test.

    Science.gov (United States)

    Barnard, Shanis; Matthews, Lindsay; Messori, Stefano; Podaliri-Vulpiani, Michele; Ferri, Nicola

    2016-01-01

    We assessed motor laterality in sheep to explore species-specific brain hemi-field dominance and how this could be affected by genetic or developmental factors. Further, we investigated whether directionality and strength of laterality could be linked to emotional stress in ewes and their lambs during partial separation. Forty-three ewes and their singleton lambs were scored on the (left/right) direction of turn in a y-maze to rejoin a conspecific (laterality test). Further, their behavioural response (i.e. time spent near the fence, vocalisations, and activity level) during forced separation by an open-mesh fence was assessed (separation test). Individual laterality was recorded for 44.2% ewes (significant right bias) and 81.4% lambs (equally biased to the left and the right). There was no significant association in side bias between dams and offspring. The Chi-squared test revealed a significant population bias for both groups (p laterality may provide explanation for this decision-making process. Absolute strength of laterality (irrespective of side) was high (Kolmogorov-Smirnov test, dams: D = 0.2; p laterality offer a potential novel non-invasive indicator of separation stress.

  5. Stress corrosion cracking test with slow strain rate and constant current

    International Nuclear Information System (INIS)

    Ondrejcin, R.S.

    1976-01-01

    A rapid electrochemical tensile test was developed for evaluating stress corrosion crack initiation in carbon steel. Constant anodic current was imposed on smooth-bar tensile specimens as the specimens were slowly strained to fracture at cross-head speeds of 1.3 x 10 -6 /sec. Equivalent response results were obtained for all ductility properties measured; uniform elongation, total elongation and reduction of area. Total elongation was chosen as the index for stress corrosion crack initiation. An equation was developed that allowed calculation of total elongation of specimens in electrolytes (test solutions) with composition ranges of 1.5 to 5.5 M nitrate, 0 to 3.5 M nitrite, and 0 to 5.0 M hydroxide, and a temperature range of 50 0 C to 100 0 C. A minimum of 13 percent total elongation was selected to indicate the possible initiation of cracking in A 285-B steel alloy. The test was used to evaluate relative aggressiveness of synthetic nuclear wastes on A 285-B carbon steel and the relative resistances of several steels to given solution compositions. Test results formed one of the bases for setting temperature limits and concentration limits for several ions in nuclear wastes that are stored in carbon steel tanks at the Savannah River Plant

  6. The conformity of BPP and vibroacoustic stimulation results in fetal non reactive non stress test

    Directory of Open Access Journals (Sweden)

    M. Modarres

    2006-08-01

    Full Text Available Background: The most frequently used test for evaluation of fetal health is the Non Stress Test (NST. Unfortunately it has a high incidence of false positive results. The combination of vibroacoustic stimulation with the NTS has been shown to reduce non reactive results. Methods: A tests assessment method was chosen with a simple randomized sampling. 40 pregnant women with non reactive NST in the first 20 minutes who received VAS in one of Tehran University's Hospitals were compared with BPP scores. A vibroacoustic stimulation was applied for a 3 seconds on the maternal abdomen and fallowed within 10 minutes.Data collection tools were NST, sonography instruments ,NST result paper, tooth brusher, watch, demographic questioner and check list. Data analysis was made by descriptive static and by using the Fisher's Exact Test (with level of significant at p<0/05. All statistical analysis were performed using an spss/win. Results: After VAS, 70% of non reactive tracing became reactive. All cases with fetal reactivity response after a VAS had a subsequent BPP score of 8 (negative predictive value of 100%. False positivity of VAS was lower than NST. Conclusion: VAS offers benefits, by decreasing the incidence of non reactive test and reducing test time. VAS lowers the rate of false positive NST. VAS is safe and allows more efficient of prenatal services. This test could be used as a rapid antepartum test to predict fetal well-being.

  7. Modelling evapotranspiration at three boreal forest stands using the CLASS: tests of parameterizations for canopy conductance and soil evaporation

    Science.gov (United States)

    Bartlett, Paul A.; McCaughey, J. Harry; Lafleur, Peter M.; Verseghy, Diana L.

    2003-03-01

    The performance of the Canadian Land Surface Scheme (CLASS) was evaluated in off-line runs, using data collected at three boreal forest stands located near Thompson, Manitoba: young jack pine, mature jack pine, and mature black spruce. The data were collected in the late spring through autumn of 1994 and 1996, as part of the Boreal Ecosystem-Atmosphere Study (BOREAS).The diurnal range in modelled soil heat flux was exaggerated at all sites. Soil evaporation was modelled poorly at the jack pine stands, with overestimation common and a step change to low evaporation as the soil dried. Replacing the soil evaporation algorithm, which was based on the estimation of a surface relative humidity value, with one based on soil moisture in the top soil layer reduced the overestimation and eliminated the step changes. Modelled water movement between soil layers was too slow at the jack pine stands. Modifying the soil hydraulic parameters to match an observed characteristic curve at the young jack pine stand produced a soil water suction that agreed more closely with measurements and improved drainage between soil layers.The latent heat flux was overestimated and the sensible heat flux underestimated at all three stands. New Jarvis-Stewart-type canopy conductance algorithms were developed from stomatal conductance measurements. At the jack pine stands, stomatal conductance scaled by leaf area index reproduced canopy conductance, but a reduction in the scaled stomatal conductance by one half was necessary at the black spruce stand, indicating a nonlinearity in the scaling of stomatal conductance for this ecosystem. The root-mean-squared error for daily average latent heat flux for the control run of the CLASS and for the best test run are 49 W m-2 and 14 W m-2 respectively at the young jack pine stand, 50 W m-2 and 15 W m-2 respectively at the old jack pine stand, and 48 W m-2 and 13 W m-2 respectively at the old black spruce stand.

  8. Testing of resveratrol microemulsion photostability and protective effect against UV induced oxidative stress

    Directory of Open Access Journals (Sweden)

    Juškaitė Vaida

    2017-06-01

    Full Text Available Resveratrol is well known for its antioxidant activity and susceptibility to ultraviolet radiation. Development of formulations providing improved stability and relevant drug delivery of resveratrol is still a challenging task. The aim of this study was to determine protective characteristics of formulated microemulsions by evaluating photoisomerization of resveratrol and to investigate the effects of resveratrol on human keratinocyte cells under oxidative stress caused by ultraviolet radiation. Incorporation of resveratrol into microemulsions resulted in increased photostability of active compounds and the results demonstrated that photodegradation of resveratrol was significantly delayed. Results of biopharmaceutical evaluation in vitro demonstrated that up to 60 % of resveratrol was released from microemulsions within 6 hours under a constant release rate profile. In vivo biological testing confirmed the ability of resveratrol to protect cells from oxidative stress and to increase cell viability. It was concluded that microemulsions might be considered in the development of UV light sensitive compounds.

  9. Test of a model of psychosocial resources, stress, and health among undereducated adults.

    Science.gov (United States)

    Barnfather, J S; Ronis, D L

    2000-02-01

    The purpose of this study was to test a model drawn from the modeling and role-modelpan>ing theory depicting relationships among psychosocial resources, perceived stress, and health for undereducated adults. A purposive sample of 171 adults enrolled at an urban adult education center completed several self-report measures: Modified Erikson Psychological Stage Inventory, Basic Need Satisfaction Inventory, Perceived Stress, and Positive Health Index. Based on a structural equation modeling analysis, psychosocial development and basic need satisfaction had significant direct effects on health, with the expected positive signs. Psychosocial development had the strongest direct effect on health and also had a strong direct effect on basic need satisfaction and an indirect effect on health. Support for the hypothesized model has important implications for nursing and other community-based care provider interventions regarding health, including strengthening psychosocial resources. Copyright 2000 John Wiley & Sons, Inc.

  10. Red wine is less stress reducing than vodka; no differences in neuroendocrine challenge test.

    Science.gov (United States)

    Jarrett, N; Peatfield, R; Glover, V

    1997-01-01

    Red wine, like the drugs reserpine and fenfluramine, causes the release of 5-hydroxytryptamine (5-HT) from storage sites in vitro. This study used a neuroendocrine challenge test design to determine whether the parallel between red wine and these drugs can be extended to central actions in healthy volunteers. Vodka diluted to an equal alcohol content was used as a control. No significant differences were observed between the groups in plasma cortisol, plasma prolactin or in temperature levels. Thus no evidence was obtained for a central 5-HT releasing action by red wine. Self-rating stress and arousal questionnaires were also given. No differences were found in arousal. However whereas vodka had a clear effect in reducing stress, red wine did not. This suggests that red wine does have psychoactive properties independent of its alcohol effects.

  11. Planning of step-stress accelerated degradation test based on the inverse Gaussian process

    International Nuclear Information System (INIS)

    Wang, Huan; Wang, Guan-jun; Duan, Feng-jun

    2016-01-01

    The step-stress accelerated degradation test (SSADT) is a useful tool for assessing the lifetime distribution of highly reliable or expensive product. Some efficient SSADT plans have been proposed when the underlying degradation follows the Wiener process or Gamma process. However, how to design an efficient SSADT plan for the inverse Gaussian (IG) process is still a problem to be solved. The aim of this paper is to provide an optimal SSADT plan for the IG degradation process. A cumulative exposure model for the SSADT is adopted, in which the product degradation path depends only on the current stress level and the degradation accumulated, and has nothing to do with the way of accumulation. Under the constraint of the total experimental budget, some design variables are optimized by minimizing the asymptotic variance of the estimated p-quantile of the lifetime distribution of the product. Finally, we use the proposed method to deal with the optimal SSADT design for a type of electrical connector based on a set of stress relaxation data. The sensitivity and stability of the SSADT plan are studied, and we find that the optimal test plan is quite robust for a moderate departure from the values of the parameters. - Highlights: • We propose an optimal SSADT plan for the IG degradation process. • A CE model is assumed in describing the degradation path of the SSADT. • The asymptotic variance of the estimated p-quantile is used as the objective function. • A set of stress relaxation data is analyzed and used for illustration of our method.

  12. Stress hormones at rest and following exercise testing predict coronary artery disease severity and outcome.

    Science.gov (United States)

    Popovic, Dejana; Damjanovic, Svetozar; Djordjevic, Tea; Martic, Dejana; Ignjatovic, Svetlana; Milinkovic, Neda; Banovic, Marko; Lasica, Ratko; Petrovic, Milan; Guazzi, Marco; Arena, Ross

    2017-09-01

    Despite considerable knowledge regarding the importance of stress in coronary artery disease (CAD) pathogenesis, its underestimation persists in routine clinical practice, in part attributable to lack of a standardized, objective assessment. The current study examined the ability of stress hormones to predict CAD severity and prognosis at basal conditions as well as during and following an exertional stimulus. Forty Caucasian subjects with significant coronary artery lesions (≥50%) were included. Within 2 months of coronary angiography, cardiopulmonary exercise testing (CPET) on a recumbent ergometer was performed in conjunction with stress echocardiography (SE). At rest, peak and after 3 min of recovery following CPET, plasma levels of cortisol, adrenocorticotropic hormone (ACTH) and NT-pro-brain natriuretic peptide (NT-pro-BNP) were measured by immunoassay sandwich technique, radioimmunoassay, and radioimmunometric technique, respectively. Subjects were subsequently followed a mean of 32 ± 10 months. Mean ejection fraction was 56.7 ± 9.6%. Subjects with 1-2 stenotic coronary arteries (SCA) demonstrated a significantly lower plasma cortisol levels during CPET compared to those with 3-SCA (p  .05). Among CPET, SE, and hormonal parameters, cortisol at rest and during CPET recovery demonstrated the best predictive value in distinguishing between 1-, 2-, and 3-SCA [area under ROC curve 0.75 and 0.77 (SE = 0.11, 0.10; p = .043, .04) for rest and recovery, respectively]. ΔCortisol peak/rest predicted cumulative cardiac events (area under ROC curve 0.75, SE = 0.10, p = .049). Cortisol at rest and following an exercise test holds predictive value for CAD severity and prognosis, further demonstrating a link between stress and unwanted cardiac events.

  13. Genotypic variation in tolerance to drought stress is highly coordinated with hydraulic conductivity-photosynthesis interplay and aquaporin expression in field-grown mulberry (Morus spp.).

    Science.gov (United States)

    Reddy, Kanubothula Sitarami; Sekhar, Kalva Madhana; Reddy, Attipalli Ramachandra

    2017-07-01

    Hydraulic conductivity quantifies the efficiency of a plant to transport water from root to shoot and is a major constriction on leaf gas exchange physiology. Mulberry (Morus spp.) is the most economically important crop for sericulture industry. In this study, we demonstrate a finely coordinated control of hydraulic dynamics on leaf gas exchange characteristics in 1-year-old field-grown mulberry genotypes (Selection-13 (S13); Kollegal Local (KL) and Kanva-2 (K2)) subjected to water stress by withholding water for 20 days and subsequent recovery for 7 days. Significant variations among three mulberry genotypes have been recorded in net photosynthetic rates (Pn), stomatal conductance and sap flow rate, as well as hydraulic conductivity in stem (KS) and leaf (KL). Among three genotypes, S13 showed significantly high rates of Pn, KS and KL both in control as well as during drought stress (DS) and recovery, providing evidence for superior drought-adaptive strategies. The plant water hydraulics-photosynthesis interplay was finely coordinated with the expression of certain key aquaporins (AQPs) in roots and leaves. Our data clearly demonstrate that expression of certain AQPs play a crucial role in hydraulic dynamics and photosynthetic carbon assimilation during DS and recovery, which could be effectively targeted towards mulberry improvement programs for drought adaptation. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  14. The limits of testing particle-mediated oxidative stress in vitro in predicting diverse pathologies; relevance for testing of nanoparticles

    Directory of Open Access Journals (Sweden)

    Gulumian Mary

    2009-04-01

    Full Text Available Abstract In vitro studies with particles are a major staple of particle toxicology, generally used to investigate mechanisms and better understand the molecular events underlying cellular effects. However, there is ethical and financial pressure in nanotoxicology, the new sub-specialty of particle toxicology, to avoid using animals. Therefore an increasing amount of studies are being published using in vitro approaches and such studies require careful interpretation. We point out here that 3 different conventional pathogenic particle types, PM10, asbestos and quartz, which cause diverse pathological effects, have been reported to cause very similar oxidative stress effects in cells in culture. We discuss the likely explanation and implications of this apparent paradox, and its relevance for testing in nanotoxicology.

  15. Stress, Social Support, and Depression: A Test of the Stress-Buffering Hypothesis in a Mexican Sample

    Science.gov (United States)

    Raffaelli, Marcela; Andrade, Flavia C. D.; Wiley, Angela R.; Sanchez-Armass, Omar; Edwards, Laura L.; Aradillas-Garcia, Celia

    2013-01-01

    This study examined social support as a potential moderator between stress and depressive symptoms among Mexican university applicants aged 16--21 years ("N" = 6,715; "M" age = 17.9 years; 55% female). In bivariate analyses, perceived stress was associated with higher levels of depressive symptoms, and social support with lower…

  16. Preliminary calculations of stress change of fuel pin using SiC/SiC composites for GFR with changing of thermal conductivity degradation by irradiation

    International Nuclear Information System (INIS)

    Lee, J. K.; Naganuma, M.

    2006-01-01

    Gas cooled Fast Reactor (GFR) is being researched as a candidate concept of Generation IV international Forum. As a main feature of GFR, it should be maintained high temperature and pressure of coolant gas for heat transfer efficiency. Such a demanding environment requires high-temperature-resistant structural materials distinguished from traditional steel material. Consequently, ceramics are promising candidate material of core components. Especially, Silicon Carbide fiber reinforced Silicon Carbide composites (SiC/SiC) have encouraging characteristics such as refractoriness, low activation and toughness. Application of new material to core components must be explained by the viewpoint of engineering validity. Therefore, present study surveyed that current report for mechanical strength and thermal conductivity of SiC/SiC composites. According to the reports, neutron irradiation environment degraded mechanical properties of SiC/SiC composites. To confirm applicability to core components, model of fuel pin using SiC/SiC composites was assumed with feasible mechanical properties. Furthermore, it was calculated and estimated that the stress caused by temperature variation of inner and outer side of assumed model of cladding tube. Stress was calculated by changing of input date such as thickness of cladding tube, temperature variation, thermal conductivity and linear power. In the range of this study, the most important factor was identified as degradation of thermal conductivity by irradiation. It caused a significant stress and limited a geometrical design of fuel pin. It was discussed that the differences of heat transfer between isotropic and anisotropic materials like a metal and composites. These results should be helpful not only to determine a design factor of core component but also to indicate an improvement direction of SiC/SiC composites. Through these work, reliability and safety of GFR will be increased

  17. Comparative Stress Corrosion Cracking and General Corrosion Resistance of Annealed and Hardened 440 C Stainless Steel - New Techniques in Stress Corrosion Testing

    Science.gov (United States)

    Mendreck, M. J.; Hurless, B. E.; Torres, P. D.; Danford, M. D.

    1998-01-01

    The corrosion and stress corrosion cracking (SCC) characteristics of annealed and hardened 440C stainless steel were evaluated in high humidity and 3.5-percent NaCl solution. Corrosion testing consisted of an evaluation of flat plates, with and without grease, in high humidity, as well as electrochemical testing in 3.5-percent NaCl. Stress corrosion testing consisted of conventional, constant strain, smooth bar testing in high humidity in addition to two relatively new techniques under evaluation at MSFC. These techniques involve either incremental or constant rate increases in the load applied to a precracked SE(B) specimen, monitoring the crack-opening-displacement response for indications of crack growth. The electrochemical corrosion testing demonstrated an order of magnitude greater general corrosion rate in the annealed 440C. All techniques for stress corrosion testing showed substantially better SCC resistance in the annealed material. The efficacy of the new techniques for stress corrosion testing was demonstrated both by the savings in time and the ability to better quantify SCC data.

  18. Comparison of exercise stress testing with dobutamine stress echocardiography and exercise technetium-99m isonitrile single photon emission computerized tomography for diagnosis of coronary artery disease

    International Nuclear Information System (INIS)

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

    1997-01-01

    To compare the value of exercise electrocardiography with dobutamine stress echocardiography and exercise technetium-99m isonitrile single-photon emission computed tomography for coronary artery disease, 70 patients with either suspected or proven coronary artery disease underwent dobutamine stress echocardiography, exercise technetium-99m isonitrile single-photon emission computed tomography (mibi-SPECT) and treadmill exercise electrocardiography (ECG). Dobutamine echocardiography and exercise mibi-SPECT revealed a higher overall sensitivity than exercise testing (90 vs 57%, p 0.05; 90 and 62% p<0.05, respectively) but the difference between dobutamine stress echocardiography and exercise mibi-SPECT was not statistically significant. Diagnostic accuracy of dobutamine stress echocardiography and exercise mibi-SPECT was higher than that of exercise testing (90 vs 59%, p<0.001; 89 vs 59%, p<0.001, respectively). Dobutamine stress echocardiography and exercise mibi-SPECT have superiority over exercise testing in the diagnosis of coronary artery disease and dobutamine stress echocardiography is an alternative for exercise mibi-SPECT. (author)

  19. Prediction of Pseudo relative velocity response spectra at Yucca Mountain for underground nuclear explosions conducted in the Pahute Mesa testing area at the Nevada testing site

    International Nuclear Information System (INIS)

    Phillips, J.S.

    1991-12-01

    The Yucca Mountain Site Characterization Project (YMP), managed by the Office of Geologic Disposal of the Office of Civilian Radioactive Waste Management of the US Department of Energy, is examining the feasibility of siting a repository for commercial, high-level nuclear wastes at Yucca Mountain on and adjacent to the Nevada Test Site (NTS). This work, intended to extend our understanding of the ground motion at Yucca Mountain resulting from testing of nuclear weapons on the NTS, was funded by the Yucca Mountain project and the Military Applications Weapons Test Program. This report summarizes one aspect of the weapons test seismic investigations conducted in FY88. Pseudo relative velocity response spectra (PSRV) have been calculated for a large body of surface ground motions generated by underground nuclear explosions. These spectra have been analyzed and fit using multiple linear regression techniques to develop a credible prediction technique for surface PSRVs. In addition, a technique for estimating downhole PSRVs at specific stations is included. A data summary, data analysis, prediction development, prediction evaluation, software summary and FORTRAN listing of the prediction technique are included in this report

  20. The utility of cardiac stress testing for detection of cardiovascular disease in breast cancer survivors: a systematic review

    Directory of Open Access Journals (Sweden)

    Kirkham AA

    2015-01-01

    Full Text Available Amy A Kirkham,1 Sean A Virani,2 Kristin L Campbell1,31Rehabilitation Sciences, 2Department of Medicine, 3Department of Physical Therapy, University of British Columbia, Vancouver, BC, CanadaBackground: Heart function tests performed with myocardial stress, or “cardiac stress tests”, may be beneficial for detection of cardiovascular disease. Women who have been diagnosed with breast cancer are more likely to develop cardiovascular diseases than the general population, in part due to the direct toxic effects of cancer treatment on the cardiovascular system. The aim of this review was to determine the utility of cardiac stress tests for the detection of cardiovascular disease after cardiotoxic breast cancer treatment.Design: Systematic review.Methods: Medline and Embase were searched for studies utilizing heart function tests in breast cancer survivors. Studies utilizing a cardiac stress test and a heart function test performed at rest were included to determine whether stress provided added benefit to identifying cardiac abnormalities that were undetected at rest within each study.Results: Fourteen studies were identified. Overall, there was a benefit to utilizing stress tests over tests at rest in identifying evidence of cardiovascular disease in five studies, a possible benefit in five studies, and no benefit in four studies. The most common type of stress test was myocardial perfusion imaging, where reversible perfusion defects were detected under stress in individuals who had no defects at rest, in five of seven studies of long-term follow-up. Two studies demonstrated the benefit of stress echocardiography over resting echocardiography for detecting left ventricular dysfunction in anthracycline-treated breast cancer survivors. There was no benefit of stress cardiac magnetic resonance imaging in one study. Two studies showed a potential benefit of stress electrocardiography, whereas three others did not.Conclusion: The use of cardiac stress