WorldWideScience

Sample records for accelerated reliability testing

  1. Developing MESA : an accelerated reliability test

    NARCIS (Netherlands)

    Baskoro, G.; Rouvroye, J.L.; Bacher, W.; Brombacher, A.C.

    2003-01-01

    This paper describes the on-going research on an accelerated reliability test strategy called MESA (Multiple Environment Stress Analysis) intended to find in a fast and efficient manner (potential) reliability problems during the design phase of high volume consumer products. This test has shown

  2. OPTIMUM DESIGN OF EXPERIMENTS FOR ACCELERATED RELIABILITY TESTING

    Directory of Open Access Journals (Sweden)

    Sebastian Marian ZAHARIA

    2014-05-01

    Full Text Available In this paper is presented a case study that demonstrates how design to experiments (DOE information can be used to design better accelerated reliability tests. In the case study described in this paper, will be done a comparison and optimization between main accelerated reliability test plans (3 Level Best Standard Plan, 3 Level Best Compromise Plan, 3 Level Best Equal Expected Number Failing Plan, 3 Level 4:2:1 Allocation Plan. Before starting an accelerated reliability test, it is advisable to have a plan that helps in accurately estimating reliability at operating conditions while minimizing test time and costs. A test plan should be used to decide on the appropriate stress levels that should be used (for each stress type and the amount of the test units that need to be allocated to the different stress levels (for each combination of the different stress types' levels. For the case study it used ALTA 7 software what provides a complete analysis for data from accelerated reliability tests

  3. Assessing high reliability via Bayesian approach and accelerated tests

    International Nuclear Information System (INIS)

    Erto, Pasquale; Giorgio, Massimiliano

    2002-01-01

    Sometimes the assessment of very high reliability levels is difficult for the following main reasons: - the high reliability level of each item makes it impossible to obtain, in a reasonably short time, a sufficient number of failures; - the high cost of the high reliability items to submit to life tests makes it unfeasible to collect enough data for 'classical' statistical analyses. In the above context, this paper presents a Bayesian solution to the problem of estimation of the parameters of the Weibull-inverse power law model, on the basis of a limited number (say six) of life tests, carried out at different stress levels, all higher than the normal one. The over-stressed (i.e. accelerated) tests allow the use of experimental data obtained in a reasonably short time. The Bayesian approach enables one to reduce the required number of failures adding to the failure information the available a priori engineers' knowledge. This engineers' involvement conforms to the most advanced management policy that aims at involving everyone's commitment in order to obtain total quality. A Monte Carlo study of the non-asymptotic properties of the proposed estimators and a comparison with the properties of maximum likelihood estimators closes the work

  4. Design of Accelerated Reliability Test for CNC Motorized Spindle Based on Vibration Signal

    Directory of Open Access Journals (Sweden)

    Chen Chao

    2016-01-01

    Full Text Available Motorized spindle is the key functional component of CNC machining centers which is a mechatronics system with long life and high reliability. The reliability test cycle of motorized spindle is too long and infeasible. This paper proposes a new accelerated test for reliability evaluation of motorized spindle. By field reliability test, authors collect and calculate the load data including rotational speed, cutting force and torque. Load spectrum distribution law is analyzed. And authors design a test platform to apply the load spectrum. A new method to define the fuzzy acceleration factor based on the vibration signal is proposed. Then the whole test plan of accelerated reliability test is done.

  5. CERN Technical training 2008 - Learning for the LHC: Special Workshop demonstrating reliability with accelerated testing

    CERN Multimedia

    2008-01-01

    Larry Edson’s workshop will show examples of quantitative reliability predictions based upon accelerated testing and demonstrates that reliability testing during the prototyping phase will help ascertain product shortcomings. When these weak points are addressed and the redesigned product is re-tested, the reliability of that product will become much higher. These methodologies successfully used in industry might be exceedingly useful also for component development in particle physics where reliability is of utmost importance. This training will provide participants with the skills necessary to demonstrate reliability requirements using accelerated testing methods. The workshop will focus on accelerated test design that employs increased stress levels. This approach has the advantage of reducing test time, sample size and test facility resources. The methodologies taught are applicable to all types of stresses, spanning the electro...

  6. CERN Technical training 2008 - Learning for the LHC: Special Workshop demonstrating reliability with accelerated testing

    CERN Multimedia

    2008-01-01

    Larry Edson’s workshop will show examples of quantitative reliability predictions based upon accelerated testing and demonstrate that reliability testing during the prototyping phase will help ascertain product shortcomings. When these weak points are addressed and the redesigned product is re-tested, the reliability of that product will become much higher. These methodologies successfully used in industry might be exceedingly useful also for component development in particle physics where reliability is of the utmost importance. This training will provide participants with the skills necessary to demonstrate reliability requirements using accelerated testing methods. The workshop will focus on accelerated test design that employs increased stress levels. This approach has the advantage of reducing test time, sample size and test facility resources. The methodologies taught are applicable to all types of stresses, spanning the elec...

  7. CERN Technical training 2008 - Learning for the LHC: Special workshop demonstrating reliability with accelerated testing

    CERN Multimedia

    2008-01-01

    Larry Edson’s workshop will show examples of quantitative reliability predictions based upon accelerated testing and demonstrate that reliability testing during the prototyping phase will help ascertain product shortcomings. When these weak points are addressed and the redesigned product is re-tested, the reliability of that product will become much higher. These methodologies successfully used in industry might be exceedingly useful also for component development in particle physics where reliability is of the utmost importance. This training will provide participants with the skills necessary to demonstrate reliability requirements using accelerated testing methods. The workshop will focus on accelerated test design that employs increased stress levels. This approach has the advantage of reducing test time, sample size and test facility resources. The methodologies taught are applicable to all types of stresses, spanning the elec...

  8. The Accelerator Reliability Forum

    CERN Document Server

    Lüdeke, Andreas; Giachino, R

    2014-01-01

    A high reliability is a very important goal for most particle accelerators. The biennial Accelerator Reliability Workshop covers topics related to the design and operation of particle accelerators with a high reliability. In order to optimize the over-all reliability of an accelerator one needs to gather information on the reliability of many different subsystems. While a biennial workshop can serve as a platform for the exchange of such information, the authors aimed to provide a further channel to allow for a more timely communication: the Particle Accelerator Reliability Forum [1]. This contribution will describe the forum and advertise it’s usage in the community.

  9. Reliability demonstration methodology for products with Gamma Process by optimal accelerated degradation testing

    International Nuclear Information System (INIS)

    Zhang, Chunhua; Lu, Xiang; Tan, Yuanyuan; Wang, Yashun

    2015-01-01

    For products with high reliability and long lifetime, accelerated degradation testing (ADT) may be adopted during product development phase to verify whether its reliability satisfies the predetermined level within feasible test duration. The actual degradation from engineering is usually a strictly monotonic process, such as fatigue crack growth, wear, and erosion. However, the method for reliability demonstration by ADT with monotonic degradation process has not been investigated so far. This paper proposes a reliability demonstration methodology by ADT for this kind of product. We first apply Gamma process to describe the monotonic degradation. Next, we present a reliability demonstration method by converting the required reliability level into allowable cumulative degradation in ADT and comparing the actual accumulative degradation with the allowable level. Further, we suggest an analytical optimal ADT design method for more efficient reliability demonstration by minimizing the asymptotic variance of decision variable in reliability demonstration under the constraints of sample size, test duration, test cost, and predetermined decision risks. The method is validated and illustrated with example on reliability demonstration of alloy product, and is applied to demonstrate the wear reliability within long service duration of spherical plain bearing in the end. - Highlights: • We present a reliability demonstration method by ADT for products with monotonic degradation process, which may be applied to verify reliability with long service life for products with monotonic degradation process within feasible test duration. • We suggest an analytical optimal ADT design method for more efficient reliability demonstration, which differs from the existed optimal ADT design for more accurate reliability estimation by different objective function and different constraints. • The methods are applied to demonstrate the wear reliability within long service duration of

  10. Accelerated life testing and reliability of high K multilayer ceramic capacitors

    Science.gov (United States)

    Minford, W. J.

    1981-01-01

    The reliability of one lot of high K multilayer ceramic capacitors was evaluated using accelerated life testing. The degradation in insulation resistance was characterized as a function of voltage and temperature. The times to failure at a voltage-temperature stress conformed to a lognormal distribution with a standard deviation approximately 0.5.

  11. Enabling More than Moore: Accelerated Reliability Testing and Risk Analysis for Advanced Electronics Packaging

    Science.gov (United States)

    Ghaffarian, Reza; Evans, John W.

    2014-01-01

    For five decades, the semiconductor industry has distinguished itself by the rapid pace of improvement in miniaturization of electronics products-Moore's Law. Now, scaling hits a brick wall, a paradigm shift. The industry roadmaps recognized the scaling limitation and project that packaging technologies will meet further miniaturization needs or ak.a "More than Moore". This paper presents packaging technology trends and accelerated reliability testing methods currently being practiced. Then, it presents industry status on key advanced electronic packages, factors affecting accelerated solder joint reliability of area array packages, and IPC/JEDEC/Mil specifications for characterizations of assemblies under accelerated thermal and mechanical loading. Finally, it presents an examples demonstrating how Accelerated Testing and Analysis have been effectively employed in the development of complex spacecraft thereby reducing risk. Quantitative assessments necessarily involve the mathematics of probability and statistics. In addition, accelerated tests need to be designed which consider the desired risk posture and schedule for particular project. Such assessments relieve risks without imposing additional costs. and constraints that are not value added for a particular mission. Furthermore, in the course of development of complex systems, variances and defects will inevitably present themselves and require a decision concerning their disposition, necessitating quantitative assessments. In summary, this paper presents a comprehensive view point, from technology to systems, including the benefits and impact of accelerated testing in offsetting risk.

  12. A study on the reliability evaluation of shot peened aluminium alloy using accelerated life test

    International Nuclear Information System (INIS)

    Nam, Ji Hun; Cheong, Seong Kyun; Kang, Min Woo

    2006-01-01

    In this paper, the concept of accelerated life test, which is a popular research field nowadays, is applied to the shot peened material. To predict the efficient and exact room temperature fatigue characteristics from the high temperature fatigue data, the adequate accelerated model is investigated. Ono type rotary bending fatigue tester and high temperature chamber were used for the experiment. Room temperature fatigue lives were predicted by applying accelerated models and doing reliability evaluation. Room temperature fatigue tests were accomplished to check the effectiveness of predicted data and the adequate accelerated life test models were presented by considering errors. Experimental result using Arrhenius model, fatigue limit obtain almost 5.45% of error, inverse power law has about 1.36% of error, so we found that inverse power law is applied well to temperature-life relative of shot peended material

  13. 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.

  14. Reliability assessment for metallized film pulse capacitors with accelerated degradation test

    International Nuclear Information System (INIS)

    Zhao Jianyin; Liu Fang; Xi Wenjun; He Shaobo; Wei Xiaofeng

    2011-01-01

    The high energy density self-healing metallized film pulse capacitor has been applied to all kinds of laser facilities for their power conditioning systems, whose reliability is straightforward affected by the reliability level of capacitors. Reliability analysis of highly reliable devices, such as metallized film capacitors, is a challenge due to cost and time restriction. Accelerated degradation test provides a way to predict its life cost and time effectively. A model and analyses for accelerated degradation data of metallized film capacitors are described. Also described is a method for estimating the distribution of failure time. The estimation values of the unknown parameters in this model are 9.066 9 x 10 -8 and 0.022 1. Both the failure probability density function (PDF) and the cumulative distribution function (CDF) can be presented by this degradation failure model. Based on these estimation values and the PDF/CDF, the reliability model of the metallized film capacitors is obtained. According to the reliability model, the probability of the capacitors surviving to 20 000 shot is 0.972 4. (authors)

  15. Accelerator reliability workshop

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, L; Duru, Ph; Koch, J M; Revol, J L; Van Vaerenbergh, P; Volpe, A M; Clugnet, K; Dely, A; Goodhew, D

    2002-07-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop.

  16. Accelerator reliability workshop

    International Nuclear Information System (INIS)

    Hardy, L.; Duru, Ph.; Koch, J.M.; Revol, J.L.; Van Vaerenbergh, P.; Volpe, A.M.; Clugnet, K.; Dely, A.; Goodhew, D.

    2002-01-01

    About 80 experts attended this workshop, which brought together all accelerator communities: accelerator driven systems, X-ray sources, medical and industrial accelerators, spallation sources projects (American and European), nuclear physics, etc. With newly proposed accelerator applications such as nuclear waste transmutation, replacement of nuclear power plants and others. Reliability has now become a number one priority for accelerator designers. Every part of an accelerator facility from cryogenic systems to data storage via RF systems are concerned by reliability. This aspect is now taken into account in the design/budget phase, especially for projects whose goal is to reach no more than 10 interruptions per year. This document gathers the slides but not the proceedings of the workshop

  17. A Bayesian reliability evaluation method with integrated accelerated degradation testing and field information

    International Nuclear Information System (INIS)

    Wang, Lizhi; Pan, Rong; Li, Xiaoyang; Jiang, Tongmin

    2013-01-01

    Accelerated degradation testing (ADT) is a common approach in reliability prediction, especially for products with high reliability. However, oftentimes the laboratory condition of ADT is different from the field condition; thus, to predict field failure, one need to calibrate the prediction made by using ADT data. In this paper a Bayesian evaluation method is proposed to integrate the ADT data from laboratory with the failure data from field. Calibration factors are introduced to calibrate the difference between the lab and the field conditions so as to predict a product's actual field reliability more accurately. The information fusion and statistical inference procedure are carried out through a Bayesian approach and Markov chain Monte Carlo methods. The proposed method is demonstrated by two examples and the sensitivity analysis to prior distribution assumption

  18. Reliability data collection on IC and VLSI devices tested under accelerated life conditions

    International Nuclear Information System (INIS)

    Barry, D.M.; Meniconi, M.

    1986-01-01

    As part of a more general investigation into the reliability and failure causes of semiconductor devices, statistical samples of integrated circuit devices (LM741C) and dynamic random access memory devices (TMS4116) were tested destructively to failure using elevated temperature as the accelerating stress. The devices were operated during the life test and the failure data generated were collected automatically using a multiple question-and-answer program and a process control computer. The failure data were modelled from the lognormal, inverse Gaussian and Weibull distribution using an Arrhenius reaction rate model. The failed devices were later decapsulated for failure cause determination. (orig./DG)

  19. An accelerated stress testing program for determining the reliability sensitivity of silicon solar cells to encapsulation and metallization systems

    Science.gov (United States)

    Lathrop, J. W.; Davis, C. W.; Royal, E.

    1982-01-01

    The use of accelerated testing methods in a program to determine the reliability attributes of terrestrial silicon solar cells is discussed. Different failure modes are to be expected when cells with and without encapsulation are subjected to accelerated testing and separate test schedules for each are described. Unencapsulated test cells having slight variations in metallization are used to illustrate how accelerated testing can highlight different diffusion related failure mechanisms. The usefulness of accelerated testing when applied to encapsulated cells is illustrated by results showing that moisture related degradation may be many times worse with some forms of encapsulation than with no encapsulation at all.

  20. Long-Term Reliability of SiGe/Si HBTs From Accelerated Lifetime Testing

    Science.gov (United States)

    Bhattacharya, Pallab

    2001-01-01

    Accelerated lifetime tests were performed on double-mesa structure Si(0.7)Ge(0.3)/Si npn heterojunction bipolar transistors, grown by molecular beam epitaxy, in the temperature range of 175 C-275 C. The transistors (with 5x20 sq micron emitter area) have DC current gains approx. 40-50 and f(sub T) and f(sub max) of up to 22 GHz and 25 GHz, respectively. It is found that a gradual degradation in these devices is caused by the recombination enhanced impurity diffusion (REID) of boron atoms from the p-type base region and the associated formation of parasitic energy barriers to electron transport from the emitter to collector layers. This REED has been quantitatively modeled and explained, to the first order of approximation, and the agreement with the measured data is good. The mean time to failure (MTTF) of these devices at room temperature under 1.35 x 10(exp 4) A/sq cm current density operation is estimated from the extrapolation of the Arrhenius plots of device lifetime versus reciprocal temperature. The results of the reliability tests offer valuable feedback for SiGe heterostructure design in order to improve the long-term reliability of the devices and circuits made with them. Hot electron induced degradation of the base-emitter junction was also observed during the accelerated lifetime testing. In order to improve the HBT reliability endangered by the hot electrons, deuterium sintered techniques have been proposed. The preliminary results from this study show that a deuterium-sintered HBT is, indeed, more resistant to hot-electron induced base-emitter junction degradation.

  1. Reliability and Lifetime Prediction of Remote Phosphor Plates in Solid-State Lighting Applications Using Accelerated Degradation Testing

    NARCIS (Netherlands)

    Yazdan Mehr, M.; van Driel, W.D.; Zhang, G.Q.

    2015-01-01

    A methodology, based on accelerated degradation testing, is developed to predict the lifetime of remote phosphor plates used in solid-state lighting (SSL) applications. Both thermal stress and light intensity are used to accelerate degradation reaction in remote phosphor plates. A reliability model,

  2. Note: An online testing method for lifetime projection of high power light-emitting diode under accelerated reliability test.

    Science.gov (United States)

    Chen, Qi; Chen, Quan; Luo, Xiaobing

    2014-09-01

    In recent years, due to the fast development of high power light-emitting diode (LED), its lifetime prediction and assessment have become a crucial issue. Although the in situ measurement has been widely used for reliability testing in laser diode community, it has not been applied commonly in LED community. In this paper, an online testing method for LED life projection under accelerated reliability test was proposed and the prototype was built. The optical parametric data were collected. The systematic error and the measuring uncertainty were calculated to be within 0.2% and within 2%, respectively. With this online testing method, experimental data can be acquired continuously and sufficient amount of data can be gathered. Thus, the projection fitting accuracy can be improved (r(2) = 0.954) and testing duration can be shortened.

  3. Development of an accelerated reliability test schedule for terrestrial solar cells

    Science.gov (United States)

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

    1981-01-01

    An accelerated test schedule using a minimum amount of tests and a minimum number of cells has been developed on the basis of stress test results obtained from more than 1500 cells of seven different cell types. The proposed tests, which include bias-temperature, bias-temperature-humidity, power cycle, thermal cycle, and thermal shock tests, use as little as 10 and up to 25 cells, depending on the test type.

  4. Advanced Accelerated Power Cycling Test for Reliability Investigation of Power Device Modules

    DEFF Research Database (Denmark)

    Choi, Uimin; Jørgensen, Søren; Blaabjerg, Frede

    2016-01-01

    This paper presents an apparatus and methodology for an advanced accelerated power cycling test of insulated-gate bipolar transistor (IGBT) modules. In this test, the accelerated power cycling test can be performed under more realistic electrical operating conditions with online wear-out monitoring...... of tested power IGBT module. The various realistic electrical operating conditions close to real three-phase converter applications can be achieved by the simple control method. Further, by the proposed concept of applying the temperature stress, it is possible to apply various magnitudes of temperature...... swing in a short cycle period and to change the temperature cycle period easily. Thanks to a short temperature cycle period, test results can be obtained in a reasonable test time. A detailed explanation of apparatus such as configuration and control methods for the different functions of accelerated...

  5. Lifetime prediction and reliability estimation methodology for Stirling-type pulse tube refrigerators by gaseous contamination accelerated degradation testing

    Science.gov (United States)

    Wan, Fubin; Tan, Yuanyuan; Jiang, Zhenhua; Chen, Xun; Wu, Yinong; Zhao, Peng

    2017-12-01

    Lifetime and reliability are the two performance parameters of premium importance for modern space Stirling-type pulse tube refrigerators (SPTRs), which are required to operate in excess of 10 years. Demonstration of these parameters provides a significant challenge. This paper proposes a lifetime prediction and reliability estimation method that utilizes accelerated degradation testing (ADT) for SPTRs related to gaseous contamination failure. The method was experimentally validated via three groups of gaseous contamination ADT. First, the performance degradation model based on mechanism of contamination failure and material outgassing characteristics of SPTRs was established. Next, a preliminary test was performed to determine whether the mechanism of contamination failure of the SPTRs during ADT is consistent with normal life testing. Subsequently, the experimental program of ADT was designed for SPTRs. Then, three groups of gaseous contamination ADT were performed at elevated ambient temperatures of 40 °C, 50 °C, and 60 °C, respectively and the estimated lifetimes of the SPTRs under normal condition were obtained through acceleration model (Arrhenius model). The results show good fitting of the degradation model with the experimental data. Finally, we obtained the reliability estimation of SPTRs through using the Weibull distribution. The proposed novel methodology enables us to take less than one year time to estimate the reliability of the SPTRs designed for more than 10 years.

  6. Designing reliability into accelerators

    International Nuclear Information System (INIS)

    Hutton, A.

    1992-08-01

    For the next generation of high performance, high average luminosity colliders, the ''factories,'' reliability engineering must be introduced right at the inception of the project and maintained as a central theme throughout the project. There are several aspects which will be addressed separately: Concept; design; motivation; management techniques; and fault diagnosis

  7. Accelerated reliability demonstration under competing failure modes

    International Nuclear Information System (INIS)

    Luo, Wei; Zhang, Chun-hua; Chen, Xun; Tan, Yuan-yuan

    2015-01-01

    The conventional reliability demonstration tests are difficult to apply to products with competing failure modes due to the complexity of the lifetime models. This paper develops a testing methodology based on the reliability target allocation for reliability demonstration under competing failure modes at accelerated conditions. The specified reliability at mission time and the risk caused by sampling of the reliability target for products are allocated for each failure mode. The risk caused by degradation measurement fitting of the target for a product involving performance degradation is equally allocated to each degradation failure mode. According to the allocated targets, the accelerated life reliability demonstration test (ALRDT) plans for the failure modes are designed. The accelerated degradation reliability demonstration test plans and the associated ALRDT plans for the degradation failure modes are also designed. Next, the test plan and the decision rules for the products are designed. Additionally, the effects of the discreteness of sample size and accepted number of failures for failure modes on the actual risks caused by sampling for the products are investigated. - Highlights: • Accelerated reliability demonstration under competing failure modes is studied. • The method is based on the reliability target allocation involving the risks. • The test plan for the products is based on the plans for all the failure modes. • Both failure mode and degradation failure modes are considered. • The error of actual risks caused by sampling for the products is small enough

  8. Accelerator Availability and Reliability Issues

    Energy Technology Data Exchange (ETDEWEB)

    Steve Suhring

    2003-05-01

    Maintaining reliable machine operations for existing machines as well as planning for future machines' operability present significant challenges to those responsible for system performance and improvement. Changes to machine requirements and beam specifications often reduce overall machine availability in an effort to meet user needs. Accelerator reliability issues from around the world will be presented, followed by a discussion of the major factors influencing machine availability.

  9. Leveraging accelerated testing of LED drivers to model the reliability of two-stage and multi-channel drivers

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Lynn; Perkins, Curtis; Smith, Aaron; Clark, Terry; Mills, Karmann

    2017-05-30

    The next wave of LED lighting technology is likely to be tunable white lighting (TWL) devices which can adjust the colour of the emitted light between warm white (~ 2700 K) and cool white (~ 6500 K). This type of lighting system uses LED assemblies of two or more colours each controlled by separate driver channels that independently adjust the current levels to achieve the desired lighting colour. Drivers used in TWL devices are inherently more complex than those found in simple SSL devices, due to the number of electrical components in the driver required to achieve this level of control. The reliability of such lighting systems can only be studied using accelerated stress tests (AST) that accelerate the aging process to time frames that can be accommodated in laboratory testing. This paper describes AST methods and findings developed from AST data that provide insights into the lifetime of the main components of one-channel and multi-channel LED devices. The use of AST protocols to confirm product reliability is necessary to ensure that the technology can meet the performance and lifetime requirements of the intended application.

  10. Assembly reliability of CSPs with various chiip sizes by accelerated thermal and mechanical cycling test

    Science.gov (United States)

    Ghaffarian, R.

    2000-01-01

    A JPL-led chip scale package (CSP) Consortium, composed of team members representing government agencies and private companies, recently joined together to pool in-kind resources for developing the quality and reliability of chip scale packages (CSPs) for a variety of projects.

  11. Reliability and Validity of a New Test of Change-of-Direction Speed for Field-Based Sports: the Change-of-Direction and Acceleration Test (CODAT).

    Science.gov (United States)

    Lockie, Robert G; Schultz, Adrian B; Callaghan, Samuel J; Jeffriess, Matthew D; Berry, Simon P

    2013-01-01

    Field sport coaches must use reliable and valid tests to assess change-of-direction speed in their athletes. Few tests feature linear sprinting with acute change- of-direction maneuvers. The Change-of-Direction and Acceleration Test (CODAT) was designed to assess field sport change-of-direction speed, and includes a linear 5-meter (m) sprint, 45° and 90° cuts, 3- m sprints to the left and right, and a linear 10-m sprint. This study analyzed the reliability and validity of this test, through comparisons to 20-m sprint (0-5, 0-10, 0-20 m intervals) and Illinois agility run (IAR) performance. Eighteen Australian footballers (age = 23.83 ± 7.04 yrs; height = 1.79 ± 0.06 m; mass = 85.36 ± 13.21 kg) were recruited. Following familiarization, subjects completed the 20-m sprint, CODAT, and IAR in 2 sessions, 48 hours apart. Intra-class correlation coefficients (ICC) assessed relative reliability. Absolute reliability was analyzed through paired samples t-tests (p ≤ 0.05) determining between-session differences. Typical error (TE), coefficient of variation (CV), and differences between the TE and smallest worthwhile change (SWC), also assessed absolute reliability and test usefulness. For the validity analysis, Pearson's correlations (p ≤ 0.05) analyzed between-test relationships. Results showed no between-session differences for any test (p = 0.19-0.86). CODAT time averaged ~6 s, and the ICC and CV equaled 0.84 and 3.0%, respectively. The homogeneous sample of Australian footballers meant that the CODAT's TE (0.19 s) exceeded the usual 0.2 x standard deviation (SD) SWC (0.10 s). However, the CODAT is capable of detecting moderate performance changes (SWC calculated as 0.5 x SD = 0.25 s). There was a near perfect correlation between the CODAT and IAR (r = 0.92), and very large correlations with the 20-m sprint (r = 0.75-0.76), suggesting that the CODAT was a valid change-of-direction speed test. Due to movement specificity, the CODAT has value for field sport

  12. Bayes Analysis and Reliability Implications of Stress-Rupture Testing a Kevlar/Epoxy COPV Using Temperature and Pressure Acceleration

    Science.gov (United States)

    Phoenix, S. Leigh; Kezirian, Michael T.; Murthy, Pappu L. N.

    2009-01-01

    Composite Overwrapped Pressure Vessels (COPVs) that have survived a long service time under pressure generally must be recertified before service is extended. Flight certification is dependent on the reliability analysis to quantify the risk of stress rupture failure in existing flight vessels. Full certification of this reliability model would require a statistically significant number of lifetime tests to be performed and is impractical given the cost and limited flight hardware for certification testing purposes. One approach to confirm the reliability model is to perform a stress rupture test on a flight COPV. Currently, testing of such a Kevlar49 (Dupont)/epoxy COPV is nearing completion. The present paper focuses on a Bayesian statistical approach to analyze the possible failure time results of this test and to assess the implications in choosing between possible model parameter values that in the past have had significant uncertainty. The key uncertain parameters in this case are the actual fiber stress ratio at operating pressure, and the Weibull shape parameter for lifetime; the former has been uncertain due to ambiguities in interpreting the original and a duplicate burst test. The latter has been uncertain due to major differences between COPVs in the database and the actual COPVs in service. Any information obtained that clarifies and eliminates uncertainty in these parameters will have a major effect on the predicted reliability of the service COPVs going forward. The key result is that the longer the vessel survives, the more likely the more optimistic stress ratio model is correct. At the time of writing, the resulting effect on predicted future reliability is dramatic, increasing it by about one "nine," that is, reducing the predicted probability of failure by an order of magnitude. However, testing one vessel does not change the uncertainty on the Weibull shape parameter for lifetime since testing several vessels would be necessary.

  13. Accelerated life testing of spacecraft subsystems

    Science.gov (United States)

    Wiksten, D.; Swanson, J.

    1972-01-01

    The rationale and requirements for conducting accelerated life tests on electronic subsystems of spacecraft are presented. A method for applying data on the reliability and temperature sensitivity of the parts contained in a sybsystem to the selection of accelerated life test parameters is described. Additional considerations affecting the formulation of test requirements are identified, and practical limitations of accelerated aging are described.

  14. Study and implementation of a thermal acceleration test for the improvement of the quality and reliability of components and systems; Estudo e implementacao de um teste de aceleracao termica para a melhoria da qualidade e confiabilidade de componentes e sistemas

    Energy Technology Data Exchange (ETDEWEB)

    Leao, Felippe Carneiro

    1993-09-01

    The objective of this work is to introduce the application of the burn-in test (test of thermal acceleration) in electronic products, using the practical example of this test in a power supply and to do an analysis of the application of this test in a production line showing the advantages and disadvantages of its implementation. For that it is made an abbreviation presentation of the basic concepts of quality and reliability. Starting from these concepts are presented the statistical models used in reliability, that describe the behavior of life of products and components. Besides showing, from the speed chemical reaction model , the influence of the temperature about this reliability.

  15. Accelerated reliability testing of highly aligned single-walled carbon nanotube networks subjected to DC electrical stressing.

    Science.gov (United States)

    Strus, Mark C; Chiaramonti, Ann N; Kim, Young Lae; Jung, Yung Joon; Keller, Robert R

    2011-07-01

    We investigate the electrical reliability of nanoscale lines of highly aligned, networked, metallic/semiconducting single-walled carbon nanotubes (SWCNTs) fabricated through a template-based fluidic assembly process. We find that these SWCNT networks can withstand DC current densities larger than 10 MA cm(-2) for several hours and, in some cases, several days. We develop test methods that show that the degradation rate, failure predictability and total device lifetime can be linked to the initial resistance. Scanning electron and transmission electron microscopy suggest that fabrication variability plays a critical role in the rate of degradation, and we offer an empirical method of quickly determining the long-term performance of a network. We find that well-fabricated lines subject to constant electrical stress show a linear accumulation of damage reminiscent of electromigration in metallic interconnects, and we explore the underlying physical mechanisms that could cause such behavior.

  16. Accelerated test program

    Science.gov (United States)

    Ford, F. E.; Harkness, J. M.

    1977-01-01

    A brief discussion on the accelerated testing of batteries is given. The statistical analysis and the various aspects of the modeling that was done and the results attained from the model are also briefly discussed.

  17. Proof tests on reliability

    International Nuclear Information System (INIS)

    Mishima, Yoshitsugu

    1983-01-01

    In order to obtain public understanding on nuclear power plants, tests should be carried out to prove the reliability and safety of present LWR plants. For example, the aseismicity of nuclear power plants must be verified by using a large scale earthquake simulator. Reliability test began in fiscal 1975, and the proof tests on steam generators and on PWR support and flexure pins against stress corrosion cracking have already been completed, and the results have been internationally highly appreciated. The capacity factor of the nuclear power plant operation in Japan rose to 80% in the summer of 1983, and considering the period of regular inspection, it means the operation of almost full capacity. Japanese LWR technology has now risen to the top place in the world after having overcome the defects. The significance of the reliability test is to secure the functioning till the age limit is reached, to confirm the correct forecast of deteriorating process, to confirm the effectiveness of the remedy to defects and to confirm the accuracy of predicting the behavior of facilities. The reliability of nuclear valves, fuel assemblies, the heat affected zones in welding, reactor cooling pumps and electric instruments has been tested or is being tested. (Kako, I.)

  18. Accelerated cyclic corrosion tests

    Directory of Open Access Journals (Sweden)

    Prošek T.

    2016-06-01

    Full Text Available Accelerated corrosion testing is indispensable for material selection, quality control and both initial and residual life time prediction for bare and painted metallic, polymeric, adhesive and other materials in atmospheric exposure conditions. The best known Neutral Salt Spray (NSS test provides unrealistic conditions and poor correlation to exposures in atmosphere. Modern cyclic accelerated corrosion tests include intermittent salt spray, wet and dry phases and eventually other technical phases. They are able to predict the material performance in service more correctly as documented on several examples. The use of NSS should thus be restricted for quality control.

  19. Accelerated testing of composites

    Science.gov (United States)

    Papazian, H. A.

    1983-01-01

    It is shown that the Zhurkov method for testing the strength of solids can be applied to dynamic tension and to cyclic loading and provides a viable approach to accelerated testing of composites. Data from the literature are used to demonstrate a straightforward application of the method to dynamic tension of glass fiber and cyclic loading for glass/polymer, metal matrix, and graphite/epoxy composites. Zhurkov's equation can be used at relatively high loads to obtain failure times at any temperature of interest. By taking a few data points at one or two other temperatures the spectrum of failure times can be expanded to temperatures not easily accessible.

  20. Reliability Considerations for the Operation of Large Accelerator User Facilities

    CERN Document Server

    Willeke, F.J.

    2016-01-01

    The lecture provides an overview of considerations relevant for achieving highly reliable operation of accelerator based user facilities. The article starts with an overview of statistical reliability formalism which is followed by high reliability design considerations with examples. The article closes with operational aspects of high reliability such as preventive maintenance and spares inventory.

  1. 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.

  2. The Next Linear Collider Test Accelerator

    International Nuclear Information System (INIS)

    Ruth, R.D.; Adolphsen, C.; Bane, K.

    1993-04-01

    During the past several years, there has been tremendous progress the development of the RF system and accelerating structures for a Next Linear Collider (NLC). Developments include high-power klystrons, RF pulse compression systems and damped/detuned accelerator structures to reduce wakefields. In order to integrate these separate development efforts into an actual X-band accelerator capable of accelerating the electron beams necessary for an NLC, we are building an NLC Test Accelerator (NLCTA). The goal of the NLCTA is to bring together all elements of the entire accelerating system by constructing and reliably operating an engineered model of a high-gradient linac suitable for the NLC. The NLCTA will serve as a testbed as the design of the NLC evolves. In addition to testing the RF acceleration system, the NLCTA is designed to address many questions related to the dynamics of the beam during acceleration. In this paper, we will report oil the status of the design, component development, and construction of the NLC Test Accelerator

  3. Role of failure-mechanism identification in accelerated testing

    Science.gov (United States)

    Hu, J. M.; Barker, D.; Dasgupta, A.; Arora, A.

    1993-01-01

    Accelerated life testing techniques provide a short-cut method to investigate the reliability of electronic devices with respect to certain dominant failure mechanisms that occur under normal operating conditions. However, accelerated tests have often been conducted without knowledge of the failure mechanisms and without ensuring that the test accelerated the same mechanism as that observed under normal operating conditions. This paper summarizes common failure mechanisms in electronic devices and packages and investigates possible failure mechanism shifting during accelerated testing.

  4. Reliability of high power electron accelerators for radiation processing

    International Nuclear Information System (INIS)

    Zimek, Z.

    2011-01-01

    Accelerators applied for radiation processing are installed in industrial facilities where accelerator availability coefficient should be at the level of 95% to fulfill requirements according to industry standards. Usually the exploitation of electron accelerator reviles the number of short and few long lasting failures. Some technical shortages can be overcome by practical implementation the experience gained in accelerator technology development by different accelerator manufactures. The reliability/availability of high power accelerators for application in flue gas treatment process must be dramatically improved to meet industrial standards. Support of accelerator technology dedicated for environment protection should be provided by governmental and international institutions to overcome accelerator reliability/availability problem and high risk and low direct profit in this particular application. (author)

  5. Reliability of high power electron accelerators for radiation processing

    Energy Technology Data Exchange (ETDEWEB)

    Zimek, Z. [Department of Radiation Chemistry and Technology, Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    2011-07-01

    Accelerators applied for radiation processing are installed in industrial facilities where accelerator availability coefficient should be at the level of 95% to fulfill requirements according to industry standards. Usually the exploitation of electron accelerator reviles the number of short and few long lasting failures. Some technical shortages can be overcome by practical implementation the experience gained in accelerator technology development by different accelerator manufactures. The reliability/availability of high power accelerators for application in flue gas treatment process must be dramatically improved to meet industrial standards. Support of accelerator technology dedicated for environment protection should be provided by governmental and international institutions to overcome accelerator reliability/availability problem and high risk and low direct profit in this particular application. (author)

  6. The Brookhaven Accelerator Test Facility

    International Nuclear Information System (INIS)

    Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, J.; Fisher, A.S.; Gallardo, J.; Jialin, Xie; Kirk, H.G.; Parsa, Z.; Palmer, R.B.; Rao, T.; Rogers, J.; Sheehan, J.; Tsang, T.Y.F.; Ulc, S.; Van Steenbergen, A.; Woodle, M.; Zhang, R.S.; McDonald, K.T.; Russell, D.P.; Jiang, Z.Y.; Pellegrini, C.; Wang, X.J.

    1990-01-01

    The Accelerator Test Facility (ATF), presently under construction at Brookhaven National laboratory, is described. It consists of a 50-MeV electron beam synchronizable to a high-peak power CO 2 laser. The interaction of electrons with the laser field will be probed, with some emphasis on exploring laser-based acceleration techniques. 5 refs., 2 figs

  7. Quantitative accelerated degradation testing: Practical approaches

    International Nuclear Information System (INIS)

    Mohammadian, S. Hossein; Ait-Kadi, Daoud; Routhier, Francois

    2010-01-01

    The concept of accelerated testing by tracking degradation of samples over test time needs to be developed for reliability estimation. This paper aims at proposing practical approaches to conduct accelerated degradation testing on new and available used samples. For this purpose, product failure is related to a suitable physical property. Then, its failure time is defined as the expected time in which its property reaches the critical level. Degradation model of field samples returned from service due to a degrading failure mode has been estimated based on the least square method, and available gap between manufacturer criterion and user's claim (to report a failure) has also been discussed. For a product under some stresses, a general formula has been proposed by the superposition principle in order to estimate its degradation for independent and dependent failure modes. If used samples are available, and acceleration factor of the related test is unknown, partial aging method has been presented to considerably shorten the test time.

  8. A Statistical Perspective on Highly Accelerated Testing

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Edward V. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    Highly accelerated life testing has been heavily promoted at Sandia (and elsewhere) as a means to rapidly identify product weaknesses caused by flaws in the product's design or manufacturing process. During product development, a small number of units are forced to fail at high stress. The failed units are then examined to determine the root causes of failure. The identification of the root causes of product failures exposed by highly accelerated life testing can instigate changes to the product's design and/or manufacturing process that result in a product with increased reliability. It is widely viewed that this qualitative use of highly accelerated life testing (often associated with the acronym HALT) can be useful. However, highly accelerated life testing has also been proposed as a quantitative means for "demonstrating" the reliability of a product where unreliability is associated with loss of margin via an identified and dominating failure mechanism. It is assumed that the dominant failure mechanism can be accelerated by changing the level of a stress factor that is assumed to be related to the dominant failure mode. In extreme cases, a minimal number of units (often from a pre-production lot) are subjected to a single highly accelerated stress relative to normal use. If no (or, sufficiently few) units fail at this high stress level, some might claim that a certain level of reliability has been demonstrated (relative to normal use conditions). Underlying this claim are assumptions regarding the level of knowledge associated with the relationship between the stress level and the probability of failure. The primary purpose of this document is to discuss (from a statistical perspective) the efficacy of using accelerated life testing protocols (and, in particular, "highly accelerated" protocols) to make quantitative inferences concerning the performance of a product (e.g., reliability) when in fact there is lack-of-knowledge and uncertainty concerning

  9. Techniques for increasing the reliability of accelerator control system electronics

    International Nuclear Information System (INIS)

    Utterback, J.

    1993-09-01

    As the physical size of modern accelerators becomes larger and larger, the number of required control system circuit boards increases, and the probability of one of those circuit boards failing while in service also increases. In order to do physics, the experimenters need the accelerator to provide beam reliably with as little down time as possible. With the advent of colliding beams physics, reliability becomes even more important due to the fact that a control system failure can cause the loss of painstakingly produced antiprotons. These facts prove the importance of keeping reliability in mind when designing and maintaining accelerator control system electronics

  10. Advanced Superconducting Test Accelerator (ASTA)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Superconducting Test Accelerator (ASTA) facility will be based on upgrades to the existing NML pulsed SRF facility. ASTA is envisioned to contain 3 to 6...

  11. Accelerated testing of space batteries

    Science.gov (United States)

    Mccallum, J.; Thomas, R. E.; Waite, J. H.

    1973-01-01

    An accelerated life test program for space batteries is presented that fully satisfies empirical, statistical, and physical criteria for validity. The program includes thermal and other nonmechanical stress analyses as well as mechanical stress, strain, and rate of strain measurements.

  12. Accelerated Stress-Corrosion Testing

    Science.gov (United States)

    1986-01-01

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

  13. Tractor accelerated test on test rig

    Directory of Open Access Journals (Sweden)

    M. Mattetti

    2013-09-01

    Full Text Available The experimental tests performed to validate a tractor prototype before its production, need a substantial financial and time commitment. The tests could be reduced using accelerated tests able to reproduce on the structural part of the tractor, the same damage produced on the tractor during real life in a reduced time. These tests were usually performed reproducing a particular harsh condition a defined number of times, as for example using a bumpy road on track to carry out the test in any weather condition. Using these procedures the loads applied on the tractor structure are different with respect to those obtained during the real use, with the risk to apply loads hard to find in reality. Recently it has been demonstrated how, using the methodologies designed for cars, it is possible to also expedite the structural tests for tractors. In particular, automotive proving grounds were recently successfully used with tractors to perform accelerated structural tests able to reproduce the real use of the machine with an acceleration factor higher than that obtained with the traditional methods. However, the acceleration factor obtained with a tractor on proving grounds is in any case reduced due to the reduced speed of the tractors with respect to cars. In this context, the goal of the paper is to show the development of a methodology to perform an accelerated structural test on a medium power tractor using a 4 post test rig. In particular, several proving ground testing conditions have been performed to measure the loads on the tractor. The loads obtained were then edited to remove the not damaging portion of signals, and finally the loads obtained were reproduced in a 4 post test rig. The methodology proposed could be a valid alternative to the use of a proving ground to reproduce accelerated structural tests on tractors.

  14. Test accelerator for linear collider

    International Nuclear Information System (INIS)

    Takeda, S.; Akai, K.; Akemoto, M.; Araki, S.; Hayano, H.; Hugo, T.; Ishihara, N.; Kawamoto, T.; Kimura, Y.; Kobayashi, H.; Kubo, T.; Kurokawa, S.; Matsumoto, H.; Mizuno, H.; Odagiri, J.; Otake, Y.; Sakai, H.; Shidara, T.; Shintake, T.; Suetake, M.; Takashima, T.; Takata, K.; Takeuchi, Y.; Urakawa, J.; Yamamoto, N.; Yokoya, K.; Yoshida, M.; Yoshioka, M.; Yamaoka, Y.

    1989-01-01

    KEK has proposed to build Test Accelerator Facility (TAF) capable of producing a 2.5 GeV electron beam for the purpose of stimulating R ampersand D for linear collider in TeV region. The TAF consists of a 1.5 GeV S-band linear accelerator, 1.5 GeV damping ring and 1.0 GeV X-band linear accelerator. The TAF project will be carried forward in three phases. Through Phase-I and Phase-II, the S-band and X-band linacs will be constructed, and in Phase-III, the damping ring will be completed. The construction of TAF Phase-I has started, and the 0.2 GeV S-band injector linac has been almost completed. The Phase-I linac is composed of a 240 keV electron gun, subharmonic bunchers, prebunchers and traveling buncher followed by high-gradient accelerating structures. The SLAC 5045 klystrons are driven at 450 kV in order to obtain the rf-power of 100 MW in a 1 μs pulse duration. The rf-power from a pair of klystrons are combined into an accelerating structure. The accelerating gradient up to 100 MeV/m will be obtained in a 0.6 m long structure. 5 refs., 3 figs., 2 tabs

  15. Accelerated leach test development program

    International Nuclear Information System (INIS)

    Fuhrmann, M.; Pietrzak, R.F.; Heiser, J.; Franz, E.M.; Colombo, P.

    1990-11-01

    In FY 1989, a draft accelerated leach test for solidified waste was written. Combined test conditions that accelerate leaching were validated through experimental and modeling efforts. A computer program was developed that calculates test results and models leaching mechanisms. This program allows the user to determine if diffusion controls leaching and, if this is the case, to make projections of releases. Leaching mechanisms other than diffusion (diffusion plus source term partitioning and solubility limited leaching) are included in the program is indicators of other processes that may control leaching. Leach test data are presented and modeling results are discussed for laboratory scale waste forms composed of portland cement containing sodium sulfate salt, portland cement containing incinerator ash, and vinyl ester-styrene containing sodium sulfate. 16 refs., 38 figs., 5 tabs

  16. Reliability enhancement of Navier-Stokes codes through convergence acceleration

    Science.gov (United States)

    Merkle, Charles L.; Dulikravich, George S.

    1995-01-01

    Methods for enhancing the reliability of Navier-Stokes computer codes through improving convergence characteristics are presented. The improving of these characteristics decreases the likelihood of code unreliability and user interventions in a design environment. The problem referred to as a 'stiffness' in the governing equations for propulsion-related flowfields is investigated, particularly in regard to common sources of equation stiffness that lead to convergence degradation of CFD algorithms. Von Neumann stability theory is employed as a tool to study the convergence difficulties involved. Based on the stability results, improved algorithms are devised to ensure efficient convergence in different situations. A number of test cases are considered to confirm a correlation between stability theory and numerical convergence. The examples of turbulent and reacting flow are presented, and a generalized form of the preconditioning matrix is derived to handle these problems, i.e., the problems involving additional differential equations for describing the transport of turbulent kinetic energy, dissipation rate and chemical species. Algorithms for unsteady computations are considered. The extension of the preconditioning techniques and algorithms derived for Navier-Stokes computations to three-dimensional flow problems is discussed. New methods to accelerate the convergence of iterative schemes for the numerical integration of systems of partial differential equtions are developed, with a special emphasis on the acceleration of convergence on highly clustered grids.

  17. Quantitative Accelerated Life Testing of MEMS Accelerometers.

    Science.gov (United States)

    Bâzu, Marius; Gălăţeanu, Lucian; Ilian, Virgil Emil; Loicq, Jerome; Habraken, Serge; Collette, Jean-Paul

    2007-11-20

    Quantitative Accelerated Life Testing (QALT) is a solution for assessing thereliability of Micro Electro Mechanical Systems (MEMS). A procedure for QALT is shownin this paper and an attempt to assess the reliability level for a batch of MEMSaccelerometers is reported. The testing plan is application-driven and contains combinedtests: thermal (high temperature) and mechanical stress. Two variants of mechanical stressare used: vibration (at a fixed frequency) and tilting. Original equipment for testing at tiltingand high temperature is used. Tilting is appropriate as application-driven stress, because thetilt movement is a natural environment for devices used for automotive and aerospaceapplications. Also, tilting is used by MEMS accelerometers for anti-theft systems. The testresults demonstrated the excellent reliability of the studied devices, the failure rate in the"worst case" being smaller than 10 -7 h -1 .

  18. Accelerated Testing with Multiple Failure Modes under Several Temperature Conditions

    Directory of Open Access Journals (Sweden)

    Zongyue Yu

    2014-01-01

    Full Text Available A complicated device may have multiple failure modes, and some of the failure modes are sensitive to low temperatures. To assess the reliability of a product with multiple failure modes, this paper presents an accelerated testing in which both of the high temperatures and the low temperatures are applied. Firstly, an acceleration model based on the Arrhenius model but accounting for the influence of both the high temperatures and low temperatures is proposed. Accordingly, an accelerated testing plan including both the high temperatures and low temperatures is designed, and a statistical analysis method is developed. The reliability function of the product with multiple failure modes under variable working conditions is given by the proposed statistical analysis method. Finally, a numerical example is studied to illustrate the proposed accelerated testing. The results show that the proposed accelerated testing is rather efficient.

  19. Accelerated Testing with Multiple Failure Modes under Several Temperature Conditions

    OpenAIRE

    Zongyue Yu; Zhiqian Ren; Junyong Tao; Xun Chen

    2014-01-01

    A complicated device may have multiple failure modes, and some of the failure modes are sensitive to low temperatures. To assess the reliability of a product with multiple failure modes, this paper presents an accelerated testing in which both of the high temperatures and the low temperatures are applied. Firstly, an acceleration model based on the Arrhenius model but accounting for the influence of both the high temperatures and low temperatures is proposed. Accordingly, an accelerated testi...

  20. Improving motor reliability in nuclear power plants: Volume 2, Functional indicator tests on a small electric motor subjected to accelerated aging

    International Nuclear Information System (INIS)

    Subudhi, M.; Taylor, J.H.; Lofaro, R.; Sugarman, A.C.; Sheets, M.W.; Skreiner, K.M.

    1987-11-01

    A ten horsepower electric motor was artificially aged by plug reverse cycling for test purposes. The motor was manufactured in 1967 and was in service at a commercial nuclear power plant for twelve years. Various tests were performed on the motor throughout the aging process. The motor failed after 3.79 million reversals (3 seconds per reversal) over seven months of testing. Each test parameter was trended to assess its suitability in monitoring aging and service wear degradation in motors. Results and conclusions are discussed relative to the applicability of the tests performed to nuclear power plant motor maintenance programs. 15 refs., 28 figs., 1 tab

  1. Approach to assurance of reliability of linear accelerator operation observations

    International Nuclear Information System (INIS)

    Bakov, S.M.; Borovikov, A.A.; Kavkun, S.L.

    1994-01-01

    The system approach to solving the task of assuring reliability of observations over the linear accelerator operation is proposed. The basic principles of this method consist in application of dependences between the facility parameters, decrease in the number of the system apparatus channels for data acquisition without replacement of failed channel by reserve one. The signal commutation unit, the introduction whereof into the data acquisition system essentially increases the reliability of the measurement system on the account of active reserve, is considered detail. 8 refs. 6 figs

  2. Accelerated testing of space mechanisms

    Science.gov (United States)

    Murray, S. Frank; Heshmat, Hooshang

    1995-01-01

    This report contains a review of various existing life prediction techniques used for a wide range of space mechanisms. Life prediction techniques utilized in other non-space fields such as turbine engine design are also reviewed for applicability to many space mechanism issues. The development of new concepts on how various tribological processes are involved in the life of the complex mechanisms used for space applications are examined. A 'roadmap' for the complete implementation of a tribological prediction approach for complex mechanical systems including standard procedures for test planning, analytical models for life prediction and experimental verification of the life prediction and accelerated testing techniques are discussed. A plan is presented to demonstrate a method for predicting the life and/or performance of a selected space mechanism mechanical component.

  3. Accelerated Test Method for Corrosion Protective Coatings Project

    Science.gov (United States)

    Falker, John; Zeitlin, Nancy; Calle, Luz

    2015-01-01

    This project seeks to develop a new accelerated corrosion test method that predicts the long-term corrosion protection performance of spaceport structure coatings as accurately and reliably as current long-term atmospheric exposure tests. This new accelerated test method will shorten the time needed to evaluate the corrosion protection performance of coatings for NASA's critical ground support structures. Lifetime prediction for spaceport structure coatings has a 5-year qualification cycle using atmospheric exposure. Current accelerated corrosion tests often provide false positives and negatives for coating performance, do not correlate to atmospheric corrosion exposure results, and do not correlate with atmospheric exposure timescales for lifetime prediction.

  4. The Brookhaven National Laboratory Accelerator Test Facility

    International Nuclear Information System (INIS)

    Batchelor, K.

    1992-01-01

    The Brookhaven National Laboratory Accelerator Test Facility comprises a 50 MeV traveling wave electron linear accelerator utilizing a high gradient, photo-excited, raidofrequency electron gun as an injector and an experimental area for study of new acceleration methods or advanced radiation sources using free electron lasers. Early operation of the linear accelerator system including calculated and measured beam parameters are presented together with the experimental program for accelerator physics and free electron laser studies

  5. Preliminary tests of the electrostatic plasma accelerator

    Science.gov (United States)

    Aston, G.; Acker, T.

    1990-01-01

    This report describes the results of a program to verify an electrostatic plasma acceleration concept and to identify those parameters most important in optimizing an Electrostatic Plasma Accelerator (EPA) thruster based upon this thrust mechanism. Preliminary performance measurements of thrust, specific impulse and efficiency were obtained using a unique plasma exhaust momentum probe. Reliable EPA thruster operation was achieved using one power supply.

  6. The Brookhaven Accelerator Test Facility

    International Nuclear Information System (INIS)

    Batchelor, K.; Chou, T.S.; Fernow, R.C.; Fischer, J.; Gallardo, J.; Kirk, H.G.; Koul, R.; Palmer, R.B.; Pellegrini, C.; Sheehan, J.; Srinivasan-Rao, T.; Ulc, S.; Woodle, M.; Bigio, I.; Kurnit, N.; McDonald, K.T.

    1989-01-01

    The Brookhaven Accelerator Test Facility ATF will consist of a 50-100 MeV/c electron linac and a 100 GW CO 2 laser system. A high brightness RF-gun operating at 2,856 MHz is to be used as the injector into the linac. The RF-gun contains a Nd:Yag-laser-driven photocathode capable of producing a stream of six ps electron pulses separated by 12.5 ns. The maximum charge in a micropulse will be one nano-Coulomb. The CO 2 laser pulse length will be a few picoseconds and will be synchronized with the electron pulse. The first experimental beam is expected in Fall 89. The design electron beam parameters are given and possible initial experiments are discussed. 9 refs., 1 fig., 3 tabs

  7. The Brookhaven Accelerator Test Facility

    International Nuclear Information System (INIS)

    Batchelor, K.; Chou, T.S.; Fernow, R.C.

    1988-01-01

    The Brookhaven Accelerator Test Facility (ATF) will consist of a 50--100 MeV/c electron linac and a 100 GW CO 2 laser system. A high brightness RF-gun operating at 2856 MHz is to be used as the injector into the linac. The RF-gun contains a Nd:Yag-laser-driven photocathode capable of producing a stream of six ps electron pulses separated by 12.5 ns. The maximum charge in a micropulse will be one nano-Coulomb. The CO 2 laser pulse length will be a few picoseconds and will be synchronized with the electron pulse. The first experimental beam is expected in Fall 89. The design electron beam parameters are given and possible initial experiments are discussed. 9 refs., 1 fig., 3 tabs

  8. Reliability Estimation Based Upon Test Plan Results

    National Research Council Canada - National Science Library

    Read, Robert

    1997-01-01

    The report contains a brief summary of aspects of the Maximus reliability point and interval estimation technique as it has been applied to the reliability of a device whose surveillance tests contain...

  9. Accelerated tests of coil coatings

    Directory of Open Access Journals (Sweden)

    Rosales, B. M.

    2003-12-01

    Full Text Available Accelerated laboratory tests on 12 materials in study in the Subgroup 6 of the PATINA Network (CYTED, are discussed for different exposition periods in salt spray, SO2 and Prohesion chambers. International standards used to evaluate failures caused by the different aggressive agents of these laboratory tests are the same as those applied for outdoor expositions. The results exposed contribute to a better understanding of the mechanisms occurred in the diverse natural environments, being mentioned the main analogies and differences respect to factors affecting natural tests. They also allowed to evidence the advantages and limitations in the application of these tests during several days, as compared to the years required to attain similar failure magnitudes through outdoor tests.

    En este trabajo se discuten los ensayos de laboratorio acelerados, realizados sobre 12 materiales de estudio en el Subgrupo 6 de la Red PATINA (CYTED, a diferentes periodos de exposición en cámaras de niebla salina, SO2 y Prohesion. Se utilizaron las normas internacionales para evaluar los fallos causados por los diferentes agentes agresivos de estos ensayos de laboratorio, las cuales se aplican también para los ensayos de exposición a la intemperie. Los resultados expuestos contribuyen a una mejor comprensión de los mecanismos ocurridos en los diversos ambientes naturales, mencionándose las principales analogías y diferencias respecto de los factores que afectan los ensayos naturales. También permitieron evidenciar las ventajas y limitaciones en la aplicación de estos ensayos durante varios días, en comparación con los años requeridos para alcanzar magnitudes de fallos similares por medio de ensayos a intemperie.

  10. Accelerators for Fusion Materials Testing

    Science.gov (United States)

    Knaster, Juan; Okumura, Yoshikazu

    Fusion materials research is a worldwide endeavor as old as the parallel one working toward the long term stable confinement of ignited plasma. In a fusion reactor, the preservation of the required minimum thermomechanical properties of the in-vessel components exposed to the severe irradiation and heat flux conditions is an indispensable factor for safe operation; it is also an essential goal for the economic viability of fusion. Energy from fusion power will be extracted from the 14 MeV neutron freed as a product of the deuterium-tritium fusion reactions; thus, this kinetic energy must be absorbed and efficiently evacuated and electricity eventually generated by the conventional methods of a thermal power plant. Worldwide technological efforts to understand the degradation of materials exposed to 14 MeV neutron fluxes >1018 m-2s-1, as expected in future fusion power plants, have been intense over the last four decades. Existing neutron sources can reach suitable dpa (“displacement-per-atom”, the figure of merit to assess materials degradation from being exposed to neutron irradiation), but the differences in the neutron spectrum of fission reactors and spallation sources do not allow one to unravel the physics and to anticipate the degradation of materials exposed to fusion neutrons. Fusion irradiation conditions can be achieved through Li (d, xn) nuclear reactions with suitable deuteron beam current and energy, and an adequate flowing lithium screen. This idea triggered in the late 1970s at Los Alamos National Laboratory (LANL) a campaign working toward the feasibility of continuous wave (CW) high current linacs framed by the Fusion Materials Irradiation Test (FMIT) project. These efforts continued with the Low Energy Demonstrating Accelerator (LEDA) (a validating prototype of the canceled Accelerator Production of Tritium (APT) project), which was proposed in 2002 to the fusion community as a 6.7MeV, 100mA CW beam injector for a Li (d, xn) source to bridge

  11. Accelerated testing statistical models, test plans, and data analysis

    CERN Document Server

    Nelson, Wayne B

    2009-01-01

    The Wiley-Interscience Paperback Series consists of selected books that have been made more accessible to consumers in an effort to increase global appeal and general circulation. With these new unabridged softcover volumes, Wiley hopes to extend the lives of these works by making them available to future generations of statisticians, mathematicians, and scientists. "". . . a goldmine of knowledge on accelerated life testing principles and practices . . . one of the very few capable of advancing the science of reliability. It definitely belongs in every bookshelf on engineering.""-Dev G.

  12. Test-retest reliability of trunk accelerometric gait analysis

    DEFF Research Database (Denmark)

    Henriksen, Marius; Lund, Hans; Moe-Nilssen, R

    2004-01-01

    The purpose of this study was to determine the test-retest reliability of a trunk accelerometric gait analysis in healthy subjects. Accelerations were measured during walking using a triaxial accelerometer mounted on the lumbar spine of the subjects. Six men and 14 women (mean age 35.2; range 18...... a definite potential in clinical gait analysis....

  13. Test Reliability at the Individual Level

    Science.gov (United States)

    Hu, Yueqin; Nesselroade, John R.; Erbacher, Monica K.; Boker, Steven M.; Burt, S. Alexandra; Keel, Pamela K.; Neale, Michael C.; Sisk, Cheryl L.; Klump, Kelly

    2016-01-01

    Reliability has a long history as one of the key psychometric properties of a test. However, a given test might not measure people equally reliably. Test scores from some individuals may have considerably greater error than others. This study proposed two approaches using intraindividual variation to estimate test reliability for each person. A simulation study suggested that the parallel tests approach and the structural equation modeling approach recovered the simulated reliability coefficients. Then in an empirical study, where forty-five females were measured daily on the Positive and Negative Affect Schedule (PANAS) for 45 consecutive days, separate estimates of reliability were generated for each person. Results showed that reliability estimates of the PANAS varied substantially from person to person. The methods provided in this article apply to tests measuring changeable attributes and require repeated measures across time on each individual. This article also provides a set of parallel forms of PANAS. PMID:28936107

  14. Modeling Reliability Growth in Accelerated Stress Testing

    Science.gov (United States)

    2013-12-01

    labels = NA) axis(side = 2, tck = -.015, labels = NA) axis(side = 1, lwd = 0, line = -.6) axis(side = 2, lwd = 0, line = -.6, las = 1) mtext...side = 1, "t", line = 2) mtext(side = 2, "R(t)", line = 2.5) legend("bottomleft", c("Bi-Weibull","Tri-Weibull","NMW", "EMWE"),lty=c(1,1,3,2), lwd =c...1, lwd = 0, line = -.6) axis(side = 2, lwd = 0, line = -.6, las = 1) mtext(side = 1, "t", line = 2) mtext(side = 2, "f(t)", line = 3) legend

  15. Modeling high-Power Accelerators Reliability-SNS LINAC (SNS-ORNL); MAX LINAC (MYRRHA)

    International Nuclear Information System (INIS)

    Pitigoi, A. E.; Fernandez Ramos, P.

    2013-01-01

    Improving reliability has recently become a very important objective in the field of particle accelerators. The particle accelerators in operation are constantly undergoing modifications, and improvements are implemented using new technologies, more reliable components or redundant schemes (to obtain more reliability, strength, more power, etc.) A reliability model of SNS (Spallation Neutron Source) LINAC has been developed within MAX project and analysis of the accelerator systems reliability has been performed within the MAX project, using the Risk Spectrum reliability analysis software. The analysis results have been evaluated by comparison with the SNS operational data. Results and conclusions are presented in this paper, oriented to identify design weaknesses and provide recommendations for improving reliability of MYRRHA linear accelerator. The SNS reliability model developed for the MAX preliminary design phase indicates possible avenues for further investigation that could be needed to improve the reliability of the high-power accelerators, in view of the future reliability targets of ADS accelerators.

  16. Life estimation I and C cable insulation materials based on accelerated life testing accelerated life testing

    International Nuclear Information System (INIS)

    Santhosh, T.V.; Ramteke, P.K.; Shrestha, N.B.; Ahirwar, A.K.; Gopika, V.

    2016-01-01

    Accelerated Iife tests are becoming increasingly popular in today's industry due to the need for obtaining life data quickly and reliably. Life testing of products under higher stress levels without introducing additional failure modes can provide significant savings of both time and money. Correct analysis of data gathered via such accelerated life testing will yield parameters and other information for the product's life under use stress conditions. To be of practical use in assessing the operational behaviour of cables in NPPs, laboratory ageing aims to mimic the type of degradation observed under operational conditions. Conditions of testing therefore need to be carefully chosen to ensure that the degradation mechanism occurring in the accelerated tests are similar to those which occur in service. This paper presents the results of an investigation in which the elongation-at-break (EAB) measurements were carried on a typical control cable to predict the mean life at service conditions. A low voltage polyvinyl chloride (PVC) insulated and PVC sheathed control cable, used in NPP instrumentation and control (I and C) applications, was subjected thermal ageing at three elevated temperatures

  17. To the problem of reliability of high-voltage accelerators for industrial purposes

    International Nuclear Information System (INIS)

    Al'bertinskij, B.I.; Svin'in, M.P.; Tsepakin, S.G.

    1979-01-01

    Statistical data characterizing the reliability of ELECTRON and AVRORA-2 type accelerators are presented. Used as a reliability index was the mean time to failure of the main accelerator units. The analysis of accelerator failures allowed a number of conclusions to be drawn. The high failure rate level is connected with inadequate training of the servicing personnel and a natural period of equipment adjustment. The mathematical analysis of the failure rate showed that the main responsibility for insufficient high reliability rests with selenium diodes which are employed in the high voltage power supply. Substitution of selenium diodes by silicon ones increases time between failures. It is shown that accumulation and processing of operational statistical data will permit more accurate prediction of the reliability of produced high-voltage accelerators, make it possible to cope with the problems of planning optimal, in time, preventive inspections and repair, and to select optimal safety factors and test procedures n time, preventive inspections and repair, and to select optimal safety factors and test procedures n time, prevent

  18. Reliability and availability of high power proton accelerators

    International Nuclear Information System (INIS)

    Cho, Y.

    1999-01-01

    It has become increasingly important to address the issues of operational reliability and availability of an accelerator complex early in its design and construction phases. In this context, reliability addresses the mean time between failures and the failure rate, and availability takes into account the failure rate as well as the length of time required to repair the failure. Methods to reduce failure rates include reduction of the number of components and over-design of certain key components. Reduction of the on-line repair time can be achieved by judiciously designed hardware, quick-service spare systems and redundancy. In addition, provisions for easy inspection and maintainability are important for both reduction of the failure rate as well as reduction of the time to repair. The radiation safety exposure principle of ALARA (as low as reasonably achievable) is easier to comply with when easy inspection capability and easy maintainability are incorporated into the design. Discussions of past experience in improving accelerator availability, some recent developments, and potential R and D items are presented. (author)

  19. Advanced Test Accelerator (ATA) pulse power technology development

    International Nuclear Information System (INIS)

    Reginato, L.L.; Branum, D.; Cook, E.

    1981-01-01

    The Advanced Test Accelerator (ATA) is a pulsed linear induction accelerator with the following design parameters: 50 MeV, 10 kA, 70 ns, and 1 kHz in a ten-pulse burst. Acceleration is accomplished by means of 190 ferrite-loaded cells, each capable of maintaining a 250 kV voltage pulse for 70 ns across a 1-inch gap. The unique characteristic of this machine is its 1 kHz burst mode capability at very high currents. This paper dscribes the pulse power development program which used the Experimental Test Accelerator (ETA) technology as a starting base. Considerable changes have been made both electrically and mechanically in the pulse power components with special consideration being given to the design to achieve higher reliability. A prototype module which incorporates all the pulse power components has been built and tested for millions of shots. Prototype components and test results are described

  20. Accelerated bridge paint test program.

    Science.gov (United States)

    2011-07-06

    The accelerated bridge paint (AB-Paint) program evaluated a new Sherwin-Williams two-coat, : fast-curing paint system. The system is comprised of an organic zinc-rich primer (SW Corothane I : Galvapac One-Pack Zinc-Rich Primer B65 G11) and a polyurea...

  1. Accelerated Solar-UV Test Chamber

    Science.gov (United States)

    Gupta, A.; Laue, E. G.

    1984-01-01

    Medium-pressure mercury-vapor lamps provide high ratio of ultraviolet to total power. Chamber for evaluating solar-ultraviolet (UV) radiation damage permits accelerated testing without overheating test specimens.

  2. Cathodic Delamination Accelerated Life Test Method

    National Research Council Canada - National Science Library

    Ramotowski, Thomas S

    2007-01-01

    A method for conducting an accelerated life test of a polymer coated metallic sample includes placing the sample below the water surface in a test tank containing water and an oxygen containing gas...

  3. Accelerated life testing effects on CMOS microcircuit characteristics, phase 1

    Science.gov (United States)

    Maximow, B.

    1976-01-01

    An accelerated life test of sufficient duration to generate a minimum of 50% cumulative failures in lots of CMOS devices was conducted to provide a basis for determining the consistency of activation energy at 250 C. An investigation was made to determine whether any thresholds were exceeded during the high temperature testing, which could trigger failure mechanisms unique to that temperature. The usefulness of the 250 C temperature test as a predictor of long term reliability was evaluated.

  4. RHIC sextant test: Accelerator systems and performance

    Energy Technology Data Exchange (ETDEWEB)

    Pilat, F.; Trbojevic, D.; Ahrens, L. [and others

    1997-08-01

    One sextant of the RHIC Collider was commissioned in early 1997 with beam. We describe here the performance of the accelerator systems, instrumentation subsystems and application software. We also describe a ramping test without beam that took place after the commissioning with beam. Finally, we analyze the implications of accelerator systems performance and their impact on the planning for RHIC installation and commissioning.

  5. RHIC sextant test: Accelerator systems and performance

    International Nuclear Information System (INIS)

    Pilat, F.; Trbojevic, D.; Ahrens, L.

    1997-01-01

    One sextant of the RHIC Collider was commissioned in early 1997 with beam. We describe here the performance of the accelerator systems, instrumentation subsystems and application software. We also describe a ramping test without beam that took place after the commissioning with beam. Finally, we analyze the implications of accelerator systems performance and their impact on the planning for RHIC installation and commissioning

  6. Recent progress of the advanced test accelerator

    International Nuclear Information System (INIS)

    Prono, D.S.

    1985-01-01

    The Advanced Test Accelerator (ATA) of Lawrence Livermore National Laboratory is a linear induction accelerator whose electron beam parameters are 10 kA, 50 MeV, and 70 ns. This accelerator structure basically is a 2.5 MeV injector followed by 190 identical induction accelerator cores each of which incrementally adds 250 kV to the electron beam as it threads the center of the core. Recent work on beam stability, beam emittance and beam brightness is reported

  7. Prediction of safety critical software operational reliability from test reliability using testing environment factors

    International Nuclear Information System (INIS)

    Jung, Hoan Sung; Seong, Poong Hyun

    1999-01-01

    It has been a critical issue to predict the safety critical software reliability in nuclear engineering area. For many years, many researches have focused on the quantification of software reliability and there have been many models developed to quantify software reliability. Most software reliability models estimate the reliability with the failure data collected during the test assuming that the test environments well represent the operation profile. User's interest is however on the operational reliability rather than on the test reliability. The experiences show that the operational reliability is higher than the test reliability. With the assumption that the difference in reliability results from the change of environment, from testing to operation, testing environment factors comprising the aging factor and the coverage factor are developed in this paper and used to predict the ultimate operational reliability with the failure data in testing phase. It is by incorporating test environments applied beyond the operational profile into testing environment factors. The application results show that the proposed method can estimate the operational reliability accurately. (Author). 14 refs., 1 tab., 1 fig

  8. Testing general relativity on accelerators

    Directory of Open Access Journals (Sweden)

    Tigran Kalaydzhyan

    2015-11-01

    Full Text Available Within the general theory of relativity, the curvature of spacetime is related to the energy and momentum of the present matter and radiation. One of the more specific predictions of general relativity is the deflection of light and particle trajectories in the gravitational field of massive objects. Bending angles for electromagnetic waves and light in particular were measured with a high precision. However, the effect of gravity on relativistic massive particles was never studied experimentally. Here we propose and analyze experiments devoted to that purpose. We demonstrate a high sensitivity of the laser Compton scattering at high energy accelerators to the effects of gravity. The main observable – maximal energy of the scattered photons – would experience a significant shift in the ambient gravitational field even for otherwise negligible violation of the equivalence principle. We confirm predictions of general relativity for ultrarelativistic electrons of energy of tens of GeV at a current level of resolution and expect our work to be a starting point of further high-precision studies on current and future accelerators, such as PETRA, European XFEL and ILC.

  9. Particle accelerators test cosmological theory

    International Nuclear Information System (INIS)

    Schramm, D.N.; Steigman, G.

    1988-01-01

    Over the past decade two subfields of science, cosmology and elementary-particle physics, have become married in a symbiotic relationship that has produced a number of exciting offspring. These offspring are beginning to yield insights on the creation of spacetime and matter at epochs as early as 10 to the minus 43 to 10 to the minus 35 second after the birth of the universe in the primordial explosion known as the big bang. Important clues to the nature of the big bang itself may even come from a theory currently under development, known as the ultimate theory of everything (T.E.O.). A T.E.O. would describe all the interactions among the fundamental particles in a single bold stroke. Now that cosmology ahs begun to make predictions about elementary-particle physics, it has become conceivable that those cosmological predictions could be checked with carefully controlled accelerator experiments. It has taken more than 10 years for accelerators to reach the point where they can do the appropriate experiments, but the experiments are now in fact in progress. The preliminary results confirm the predictions of cosmology. The cosmological prediction the authors have been concerned with pertains to setting limits on the number of fundamental particles of matter. It appears that there are 12 fundamental particles, as well as their corresponding antiparticles. Six of the fundamental particles are quarks. The other six are leptons. The 12 particles are grouped in three families, each family consisting of four members. Cosmology suggests there must be a finite number of families and, further limits the possible range of to small values: only three or at most four families exist. 7 figs

  10. Accelerated Test Method for Corrosion Protective Coatings

    Data.gov (United States)

    National Aeronautics and Space Administration — This project seeks to develop a new accelerated corrosion test method that predicts the long-term corrosion protection performance of spaceport structure coatings as...

  11. Accelerated Testing Of Photothermal Degradation Of Polymers

    Science.gov (United States)

    Kim, Soon Sam; Liang, Ranty Hing; Tsay, Fun-Dow

    1989-01-01

    Electron-spin-resonance (ESR) spectroscopy and Arrhenius plots used to determine maximum safe temperature for accelerated testing of photothermal degradation of polymers. Aging accelerated by increasing illumination, temperature, or both. Results of aging tests at temperatures higher than those encountered in normal use valid as long as mechanism of degradation same throughout range of temperatures. Transition between different mechanisms at some temperature identified via transition between activation energies, manifesting itself as change in slope of Arrhenius plot at that temperature.

  12. Test-retest reliability of cognitive EEG

    Science.gov (United States)

    McEvoy, L. K.; Smith, M. E.; Gevins, A.

    2000-01-01

    OBJECTIVE: Task-related EEG is sensitive to changes in cognitive state produced by increased task difficulty and by transient impairment. If task-related EEG has high test-retest reliability, it could be used as part of a clinical test to assess changes in cognitive function. The aim of this study was to determine the reliability of the EEG recorded during the performance of a working memory (WM) task and a psychomotor vigilance task (PVT). METHODS: EEG was recorded while subjects rested quietly and while they performed the tasks. Within session (test-retest interval of approximately 1 h) and between session (test-retest interval of approximately 7 days) reliability was calculated for four EEG components: frontal midline theta at Fz, posterior theta at Pz, and slow and fast alpha at Pz. RESULTS: Task-related EEG was highly reliable within and between sessions (r0.9 for all components in WM task, and r0.8 for all components in the PVT). Resting EEG also showed high reliability, although the magnitude of the correlation was somewhat smaller than that of the task-related EEG (r0.7 for all 4 components). CONCLUSIONS: These results suggest that under appropriate conditions, task-related EEG has sufficient retest reliability for use in assessing clinical changes in cognitive status.

  13. Finding an acceleration function for calculating the reliability of redundant systems - Application to common mode failures

    International Nuclear Information System (INIS)

    Gonnot, R.

    1975-01-01

    While it may be reasonable to assume that the reliability of a system - the design of which is perfectly known - can be evaluated, it seems less easy to be sure that overall reliability is correctly estimated in the case of multiple redundancies arranged in sequence. Framatome is trying to develop a method of evaluating overall reliability correctly for its installations. For example, the protection systems in its power stations considered as a whole are such that several scram signals may be relayed in sequence when an incident occurs. These signals all involve the same components for a given type of action, but the components themselves are in fact subject to different stresses and constraints, which tend to reduce their reliability. Whatever the sequence in which these signals are transmitted (in a fast-developing accident, for example), it is possible to evaluate the actual reliability of a given system (or component) for different constraints, as the latter are generally obtained via the transient codes. By applying the so-called ''equal probability'' hypothesis one can estimate a reliability acceleration function taking into account the constraints imposed. This function is linear for the principal failure probability distribution laws. By generalizing such a method one can: (1) Perform failure calculations for redundant systems (or components) in a more general way than is possible with event trees, since one of the main parameters is the constraint exercised on that system (or component); (2) Determine failure rates of components on the basis of accelerated tests (up to complete failure of the component) which are quicker than the normal long-term tests (statistical results of operation); (3) Evaluate the multiplication factor for the reliability of a system or component in the case of common mode failures. The author presents the mathematical tools required for such a method and described their application in the cases mentioned above

  14. Reliability test for reactor internals rejuvenation technology

    International Nuclear Information System (INIS)

    Uchiyama, Junichi

    1998-01-01

    41 transparencies were presented on the subject of 'Reliability test for reactor internals rejuvenation technology'. The items presented give an introduction on the management of plant life in Japan and introduce the Nuclear Power Engineering Corporation (NUPEC). The question of what reliability tests for rejuvenation of reactor internals are is discussed in some detail and an outline of each test is given. Altogether six methods to rejuvenate reactor internals are presented, two of which have already been applied to actual plants. The presentation was supported by many detailed drawings and images

  15. Reliability testing of failed fuel location system

    International Nuclear Information System (INIS)

    Vieru, G.

    1996-01-01

    This paper presents the experimental reliability tests performed in order to prove the reliability parameters for Failed Fuel Location System (FFLS), equipment used to detect in which channel of a particular heat transport loop a fuel failure is located, and to find in which channel what particular bundle pair is failed. To do so, D20 samples from each reactor channel are sequentially monitored to detect a comparatively high level of delayed neutron activity. 15 refs, 8 figs, 2 tabs

  16. Reliability demonstration test planning using bayesian analysis

    International Nuclear Information System (INIS)

    Chandran, Senthil Kumar; Arul, John A.

    2003-01-01

    In Nuclear Power Plants, the reliability of all the safety systems is very critical from the safety viewpoint and it is very essential that the required reliability requirements be met while satisfying the design constraints. From practical experience, it is found that the reliability of complex systems such as Safety Rod Drive Mechanism is of the order of 10 -4 with an uncertainty factor of 10. To demonstrate the reliability of such systems is prohibitive in terms of cost and time as the number of tests needed is very large. The purpose of this paper is to develop a Bayesian reliability demonstrating testing procedure for exponentially distributed failure times with gamma prior distribution on the failure rate which can be easily and effectively used to demonstrate component/subsystem/system reliability conformance to stated requirements. The important questions addressed in this paper are: With zero failures, how long one should perform the tests and how many components are required to conclude with a given degree of confidence, that the component under test, meets the reliability requirement. The procedure is explained with an example. This procedure can also be extended to demonstrate with more number of failures. The approach presented is applicable for deriving test plans for demonstrating component failure rates of nuclear power plants, as the failure data for similar components are becoming available in existing plants elsewhere. The advantages of this procedure are the criterion upon which the procedure is based is simple and pertinent, the fitting of the prior distribution is an integral part of the procedure and is based on the use of information regarding two percentiles of this distribution and finally, the procedure is straightforward and easy to apply in practice. (author)

  17. Reliability studies of a high-power proton accelerator for accelerator-driven system applications for nuclear waste transmutation

    International Nuclear Information System (INIS)

    Burgazzi, Luciano; Pierini, Paolo

    2007-01-01

    The main effort of the present study is to analyze the availability and reliability of a high-performance linac (linear accelerator) conceived for Accelerator-Driven Systems (ADS) purpose and to suggest recommendations, in order both to meet the high operability goals and to satisfy the safety requirements dictated by the reactor system. Reliability Block Diagrams (RBD) approach has been considered for system modelling, according to the present level of definition of the design: component failure modes are assessed in terms of Mean Time Between Failure (MTBF) and Mean Time To Repair (MTTR), reliability and availability figures are derived, applying the current reliability algorithms. The lack of a well-established component database has been pointed out as the main issue related to the accelerator reliability assessment. The results, affected by the conservative character of the study, show a high margin for the improvement in terms of accelerator reliability and availability figures prediction. The paper outlines the viable path towards the accelerator reliability and availability enhancement process and delineates the most proper strategies. The improvement in the reliability characteristics along this path is shown as well

  18. Reliability studies of a high-power proton accelerator for accelerator-driven system applications for nuclear waste transmutation

    Energy Technology Data Exchange (ETDEWEB)

    Burgazzi, Luciano [ENEA-Centro Ricerche ' Ezio Clementel' , Advanced Physics Technology Division, Via Martiri di Monte Sole, 4, 40129 Bologna (Italy)]. E-mail: burgazzi@bologna.enea.it; Pierini, Paolo [INFN-Sezione di Milano, Laboratorio Acceleratori e Superconduttivita Applicata, Via Fratelli Cervi 201, I-20090 Segrate (MI) (Italy)

    2007-04-15

    The main effort of the present study is to analyze the availability and reliability of a high-performance linac (linear accelerator) conceived for Accelerator-Driven Systems (ADS) purpose and to suggest recommendations, in order both to meet the high operability goals and to satisfy the safety requirements dictated by the reactor system. Reliability Block Diagrams (RBD) approach has been considered for system modelling, according to the present level of definition of the design: component failure modes are assessed in terms of Mean Time Between Failure (MTBF) and Mean Time To Repair (MTTR), reliability and availability figures are derived, applying the current reliability algorithms. The lack of a well-established component database has been pointed out as the main issue related to the accelerator reliability assessment. The results, affected by the conservative character of the study, show a high margin for the improvement in terms of accelerator reliability and availability figures prediction. The paper outlines the viable path towards the accelerator reliability and availability enhancement process and delineates the most proper strategies. The improvement in the reliability characteristics along this path is shown as well.

  19. Reliability of segmental accelerations measured using a new wireless gait analysis system.

    Science.gov (United States)

    Kavanagh, Justin J; Morrison, Steven; James, Daniel A; Barrett, Rod

    2006-01-01

    The purpose of this study was to determine the inter- and intra-examiner reliability, and stride-to-stride reliability, of an accelerometer-based gait analysis system which measured 3D accelerations of the upper and lower body during self-selected slow, preferred and fast walking speeds. Eight subjects attended two testing sessions in which accelerometers were attached to the head, neck, lower trunk, and right shank. In the initial testing session, two different examiners attached the accelerometers and performed the same testing procedures. A single examiner repeated the procedure in a subsequent testing session. All data were collected using a new wireless gait analysis system, which features near real-time data transmission via a Bluetooth network. Reliability for each testing condition (4 locations, 3 directions, 3 speeds) was quantified using a waveform similarity statistic known as the coefficient of multiple determination (CMD). CMD's ranged from 0.60 to 0.98 across all test conditions and were not significantly different for inter-examiner (0.86), intra-examiner (0.87), and stride-to-stride reliability (0.86). The highest repeatability for the effect of location, direction and walking speed were for the shank segment (0.94), the vertical direction (0.91) and the fast walking speed (0.91), respectively. Overall, these results indicate that a high degree of waveform repeatability was obtained using a new gait system under test-retest conditions involving single and dual examiners. Furthermore, differences in acceleration waveform repeatability associated with the reapplication of accelerometers were small in relation to normal motor variability.

  20. Accelerated Testing of Polymeric Composites Using the Dynamic Mechanical Analyzer

    Science.gov (United States)

    Abdel-Magid, Becky M.; Gates, Thomas S.

    2000-01-01

    Creep properties of IM7/K3B composite material were obtained using three accelerated test methods at elevated temperatures. Results of flexural creep tests using the dynamic mechanical analyzer (DMA) were compared with results of conventional tensile and compression creep tests. The procedures of the three test methods are described and the results are presented. Despite minor differences in the time shift factor of the creep compliance curves, the DMA results compared favorably with the results from the tensile and compressive creep tests. Some insight is given into establishing correlations between creep compliance in flexure and creep compliance in tension and compression. It is shown that with careful consideration of the limitations of flexure creep, a viable and reliable accelerated test procedure can be developed using the DMA to obtain the viscoelastic properties of composites in extreme environments.

  1. High-voltage terminal test of a test stand for a 1-MV electrostatic accelerator

    Science.gov (United States)

    Park, Sae-Hoon; Kim, Yu-Seok

    2015-10-01

    The Korea Multipurpose Accelerator Complex has been developing a 300-kV test stand for a 1-MV electrostatic accelerator ion source. The ion source and accelerating tube will be installed in a high-pressure vessel. The ion source in the high-pressure vessel is required to have a high reliability. The test stand has been proposed and developed to confirm the stable operating conditions of the ion source. The ion source will be tested at the test stand to verify the long-time operating conditions. The test stand comprises a 300-kV high-voltage terminal, a battery for the ion-source power, a 60-Hz inverter, 200-MHz radio-frequency power supply, a 5-kV extraction power supply, a 300-kV accelerating tube, and a vacuum system. The results of the 300-kV high-voltage terminal tests are presented in this paper.

  2. Enhance pump reliability through improved inservice testing

    International Nuclear Information System (INIS)

    Healy, J.J.

    1990-01-01

    EPRI has undertaken a study to assess the effectiveness of existing testing programs to accurately monitor and predict performance changes before either pump performance degrades or an actual failure occurs. Anticipated changes in inservice testing techniques are directed towards enhancing the validity of test data, ensuring its repeatability, and avoiding deterioration of the pump assembly. There is a new-found interest in test programs of all types that has occurred, in part, because of an increase in reported pump degradation and pump failure. Inservice testing of pumps, which has long been a basis for assuring operability, has apparently produced an opposite effect; namely, the appearance of a reduction in reliability

  3. Reliability Testing Using the Vehicle Durability Simulator

    Science.gov (United States)

    2017-11-20

    techniques are employed to reduce test and simulation time. Through application of these processes and techniques the reliability characteristics...remote parameter control (RPC) software. The software is specifically designed for the data collection, analysis, and simulation processes outlined in...the selection process for determining the desired runs for simulation . 4.3 Drive File Development. After the data have been reviewed and

  4. Reliability tests for reactor internals replacement technology

    International Nuclear Information System (INIS)

    Fujimaki, K.; Uchiyama, J.; Ohtsubo, T.

    2000-01-01

    Structural damage due to aging degradation of LWR reactor internals has been reported in several nuclear plants. NUPEC has started a project to test the reliability of the technology for replacing reactor internals, which was directed at preventive maintenance before damage and repair after damage for the aging degradation. The project has been funded by the Ministry of International Trade and Industry (MITI) of Japan since 1995, and it follows the policy of a report that the MITI has formally issued in April 1996 summarizing the countermeasures to be considered for aging nuclear plants and equipment. This paper gives an outline of the whole test plans and the test results for the BWR reactor internals replacement methods; core shroud, ICM housing, and CRD Housing and stub tube. The test results have shown that the methods were reliable and the structural integrity was appropriate based on the evaluation. (author)

  5. Reliability test and failure analysis of high power LED packages

    International Nuclear Information System (INIS)

    Chen Zhaohui; Zhang Qin; Wang Kai; Luo Xiaobing; Liu Sheng

    2011-01-01

    A new type application specific light emitting diode (LED) package (ASLP) with freeform polycarbonate lens for street lighting is developed, whose manufacturing processes are compatible with a typical LED packaging process. The reliability test methods and failure criterions from different vendors are reviewed and compared. It is found that test methods and failure criterions are quite different. The rapid reliability assessment standards are urgently needed for the LED industry. 85 0 C/85 RH with 700 mA is used to test our LED modules with three other vendors for 1000 h, showing no visible degradation in optical performance for our modules, with two other vendors showing significant degradation. Some failure analysis methods such as C-SAM, Nano X-ray CT and optical microscope are used for LED packages. Some failure mechanisms such as delaminations and cracks are detected in the LED packages after the accelerated reliability testing. The finite element simulation method is helpful for the failure analysis and design of the reliability of the LED packaging. One example is used to show one currently used module in industry is vulnerable and may not easily pass the harsh thermal cycle testing. (semiconductor devices)

  6. Reliability tests for reactor internals rejuvenation technology

    International Nuclear Information System (INIS)

    Fujimaki, Katsumi; Hitoki, Yoichi; Otsubo, Toru; Uchiyama, Junichi

    1998-01-01

    Structural damage due to aging degradation of LWR reactor internals has been reported in several nuclear plants. NUPEC has started a project to test the reliability of the technology for rejuvenating reactor internals which has been funded by the Ministry of International Trade and Industry (MITI) of Japan since 1995. The project follows the policy of a report that the MITI has formally issued in April 1996 summarizing the countermeasures to be considered for aging nuclear plants and equipment. This paper gives an outline of the test plans and results which are directed at preventive maintenance before damage and repair after damage for reactor internals aging degradation. The test results for the replacement methods of ICM housing and BWR core shroud have shown that the methods were reliable and the structural integrity was appropriate based on the evaluation. (author)

  7. Optimizing conditions for an accelerated leach test

    International Nuclear Information System (INIS)

    Pietrzak, R.F.; Fuhrmann, M.; Heiser, J.; Franz, E.M.; Colombo, P.

    1988-01-01

    An accelerated leach test for low-level radioactive waste forms is being developed to provide, in a short time, data that can be extrapolated to long time periods. The approach is to provide experimental conditions that will accelerate leaching without changing the dominant release mechanism. Experimental efforts have focused on combining individual factors that have been observed to accelerate leaching. These include elevated temperature, increased leachant volume, and reduced specimen size. The response of diffusion coefficients to various acceleration factors have been evaluated and provide information on experimental parameters that need to be optimized to increase leach rates. Preliminary modeling using a diffusion mechanism (allowing for depletion) of a finite cylinder geometry indicates that during early portions of experiments (daily sampling intervals), leaching is diffusion controlled and more rapid than later in the same experiments (weekly or greater sampling intervals). For cement waste forms, this reduction in rate may be partially controlled by changes in physical structure and chemistry (sometimes related to environmental influences such as CO 2 ), but it is more likely associated with the duration of the sampling interval. By using a combination of mathematical modeling and by experimentally investigating various leach rate controlling factors, a more complete understanding of leaching processes is being developed. This, in turn, is leading to optimized accelerating conditions for a leach test

  8. Test Stand for Linear Induction Accelerator Optimization

    International Nuclear Information System (INIS)

    Ong, M; DeHope, B; Griffin, K; Goerz, D; Kihara, R; Vogtlin, G; Zentler, J M; Scarpetti, R

    2003-01-01

    Lawrence Livermore National Laboratory has designed and constructed a test stand to improve the voltage regulation in our Flash X-Ray (FXR) accelerator cell. The goal is to create a more mono-energetic electron beam that will create an x-ray source with a smaller spot size. Studying the interaction of the beam and pulse-power system with the accelerator cell will improve the design of high-current accelerators at Livermore and elsewhere. On the test stand, a standard FXR cell is driven by a flexible pulse-power system and the beam current is simulated with a switched center conductor. The test stand is fully instrumented with high-speed digitizers to document the effect of impedance mismatches when the cell is operated under various full-voltage conditions. A time-domain reflectometry technique was also developed to characterize the beam and cell interactions by measuring the impedance of the accelerator and pulse-power component. Computer models are being developed in parallel with the testing program to validate the measurements and evaluate different design changes. Both 3D transient electromagnetic and circuit models are being used

  9. The BNL Accelerator Test Facility control system

    International Nuclear Information System (INIS)

    Malone, R.; Bottke, I.; Fernow, R.; Ben-Zvi, I.

    1993-01-01

    Described is the VAX/CAMAC-based control system for Brookhaven National Laboratory's Accelerator Test Facility, a laser/linac research complex. Details of hardware and software configurations are presented along with experiences of using Vsystem, a commercial control system package

  10. Analysis of Transmitted Optical Spectrum Enabling Accelerated Testing of CPV Designs: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Miller, D. C.; Kempe, M. D.; Kennedy, C. E.; Kurtz, S. R.

    2009-07-01

    Reliability of CPV systems' materials is not well known; methods for accelerated UV testing have not been developed. UV and IR spectra transmitted through representative optical systems are evaluated.

  11. Manufacturing and Testing of Accelerator Superconducting Magnets

    International Nuclear Information System (INIS)

    Rossi, L

    2014-01-01

    Manufacturing of superconducting magnet for accelerators is a quite complex process that is not yet fully industrialized. In this paper, after a short history of the evolution of the magnet design and construction, we review the main characteristics of the accelerator magnets having an impact on the construction technology. We put in evidence how the design and component quality impact on construction and why the final product calls for a total-quality approach. LHC experience is widely discussed and main lessons are spelled out. Then the new Nb3Sn technology, under development for the next generation magnet construction, is outlined. Finally, we briefly review the testing procedure of accelerator superconducting magnets, underlining the close connection with the design validation and with the manufacturing process

  12. Manufacturing and Testing of Accelerator Superconducting Magnets

    CERN Document Server

    Rossi, L

    2014-01-01

    Manufacturing of superconducting magnet for accelerators is a quite complex process that is not yet fully industrialized. In this paper, after a short history of the evolution of the magnet design and construction, we review the main characteristics of the accelerator magnets having an impact on the construction technology. We put in evidence how the design and component quality impact on construction and why the final product calls for a total-quality approach. LHC experience is widely discussed and main lessons are spelled out. Then the new Nb$_{3}$Sn technology, under development for the next generation magnet construction, is outlined. Finally, we briefly review the testing procedure of accelerator superconducting magnets, underlining the close connection with the design validation and with the manufacturing process.

  13. Manufacturing and Testing of Accelerator Superconducting Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, L [European Organization for Nuclear Research, Geneva (Switzerland)

    2014-07-01

    Manufacturing of superconducting magnet for accelerators is a quite complex process that is not yet fully industrialized. In this paper, after a short history of the evolution of the magnet design and construction, we review the main characteristics of the accelerator magnets having an impact on the construction technology. We put in evidence how the design and component quality impact on construction and why the final product calls for a total-quality approach. LHC experience is widely discussed and main lessons are spelled out. Then the new Nb3Sn technology, under development for the next generation magnet construction, is outlined. Finally, we briefly review the testing procedure of accelerator superconducting magnets, underlining the close connection with the design validation and with the manufacturing process.

  14. Prediction of software operational reliability using testing environment factors

    International Nuclear Information System (INIS)

    Jung, Hoan Sung; Seong, Poong Hyun

    1995-01-01

    A number of software reliability models have been developed to estimate and to predict software reliability. However, there are no established standard models to quantify software reliability. Most models estimate the quality of software in reliability figures such as remaining faults, failure rate, or mean time to next failure at the testing phase, and they consider them ultimate indicators of software reliability. Experience shows that there is a large gap between predicted reliability during development and reliability measured during operation, which means that predicted reliability, or so-called test reliability, is not operational reliability. Customers prefer operational reliability to test reliability. In this study, we propose a method that predicts operational reliability rather than test reliability by introducing the testing environment factor that quantifies the changes in environments

  15. Analysis and Application of Reliability

    International Nuclear Information System (INIS)

    Jeong, Hae Seong; Park, Dong Ho; Kim, Jae Ju

    1999-05-01

    This book tells of analysis and application of reliability, which includes definition, importance and historical background of reliability, function of reliability and failure rate, life distribution and assumption of reliability, reliability of unrepaired system, reliability of repairable system, sampling test of reliability, failure analysis like failure analysis by FEMA and FTA, and cases, accelerated life testing such as basic conception, acceleration and acceleration factor, and analysis of accelerated life testing data, maintenance policy about alternation and inspection.

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

    Science.gov (United States)

    Lathrop, J. W.

    1985-01-01

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

  17. Test Particles with Acceleration-Dependent Lagrangian

    OpenAIRE

    Toller, M.

    2005-01-01

    We consider a classical test particle subject to electromagnetic and gravitational fields, described by a Lagrangian depending on the acceleration and on a fundamental length. We associate to the particle a moving local reference frame and we study its trajectory in the principal fibre bundle of all the Lorentz frames. We discuss in this framework the general form of the Lagrange equations and the connection between symmetries and conservation laws (Noether theorem). We apply these results to...

  18. Testing of a Plasmadynamic Hypervelocity Dust Accelerator

    Science.gov (United States)

    Ticos, Catalin M.; Wang, Zhehui; Dorf, Leonid A.; Wurden, G. A.

    2006-10-01

    A plasmadynamic accelerator for microparticles (or dust grains) has been designed, built and tested at Los Alamos National laboratory. The dust grains are expected to be accelerated to hypervelocities on the order of 1-30 km/s, depending on their size. The key components of the plasmadynamic accelerator are a coaxial plasma gun operated at 10 kV, a dust dispenser activated by a piezoelectric transducer, and power and remote-control systems. The coaxial plasma gun produces a high density (10^18 cm-3) and low temperature (˜ 1 eV) plasma in deuterium ejected by J x B forces, which provides drag on the dust particles in its path. Carbon dust particles will be used, with diameters from 1 to 50 μm. The plasma parameters produced in the coaxial gun are presented and their implication to dust acceleration is discussed. High speed dust will be injected in the National Spherical Torus Experiment to measure the pitch angle of magnetic field lines.

  19. Vacuum system for Advanced Test Accelerator

    International Nuclear Information System (INIS)

    Denhoy, B.S.

    1981-01-01

    The Advanced Test Accelerator (ATA) is a pulsed linear electron beam accelerator designed to study charged particle beam propagation. ATA is designed to produce a 10,000 amp 50 MeV, 70 ns electron beam. The electron beam acceleration is accomplished in ferrite loaded cells. Each cell is capable of maintaining a 70 ns 250 kV voltage pulse across a 1 inch gap. The electron beam is contained in a 5 inch diameter, 300 foot long tube. Cryopumps turbomolecular pumps, and mechanical pumps are used to maintain a base pressure of 2 x 10 -6 torr in the beam tube. The accelerator will be installed in an underground tunnel. Due to the radiation environment in the tunnel, the controlling and monitoring of the vacuum equipment, pressures and temperatures will be done from the control room through a computer interface. This paper describes the vacuum system design, the type of vacuum pumps specified, the reasons behind the selection of the pumps and the techniques used for computer interfacing

  20. Vacuum system for Advanced Test Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Denhoy, B.S.

    1981-09-03

    The Advanced Test Accelerator (ATA) is a pulsed linear electron beam accelerator designed to study charged particle beam propagation. ATA is designed to produce a 10,000 amp 50 MeV, 70 ns electron beam. The electron beam acceleration is accomplished in ferrite loaded cells. Each cell is capable of maintaining a 70 ns 250 kV voltage pulse across a 1 inch gap. The electron beam is contained in a 5 inch diameter, 300 foot long tube. Cryopumps turbomolecular pumps, and mechanical pumps are used to maintain a base pressure of 2 x 10/sup -6/ torr in the beam tube. The accelerator will be installed in an underground tunnel. Due to the radiation environment in the tunnel, the controlling and monitoring of the vacuum equipment, pressures and temperatures will be done from the control room through a computer interface. This paper describes the vacuum system design, the type of vacuum pumps specified, the reasons behind the selection of the pumps and the techniques used for computer interfacing.

  1. Optimizing conditions for an accelerated leach test

    International Nuclear Information System (INIS)

    Pietrzak, R.F.; Fuhrmann, M.; Heiser, J.; Franz, E.M.; Colombo, P.

    1988-01-01

    An accelerated leach test for low-level radioactive waste forms is being developed to provide, in a short time, data that can be extrapolated to long time periods. The approach is to provide experimental conditions that will accelerate leaching without changing the dominant release mechanism. Experimental efforts have focused on combining individual factors that have been observed to accelerate leaching. These include elevated temperature, increased leachant volume, and reduced specimen size. The response of diffusion coefficients to various acceleration factors have been evaluated and provide information on experimental parameters that need to be optimized to increase leach rates. For example, these data show that large volumes of leachant are required when leaching portland cement waste forms at elevated temperatures because of high concentrations of dissolved species. Sr-85 leaching is particularly susceptible to suppression due to concentration effects while Cs-137 leaching is less so. Preliminary modeling using a diffusion mechanism (allowing for depletion) of a finite cylinder geometry indicates that during early portions of experiments (daily sampling intervals), leaching is diffusion controlled and more rapid than later in the same experiments (weekly or greater sampling intervals). For cement waste forms, this reduction in rate may be partially controlled by changes in physical structure and chemistry (sometimes related to environmental influences such as CO 2 ), but it is more likely associated with the duration of the sampling interval. 9 refs., 6 figs

  2. A COMPUTERIZED DIAGNOSTIC COMPLEX FOR RELIABILITY TESTING OF ELECTRIC MACHINES

    Directory of Open Access Journals (Sweden)

    O.О. Somka

    2015-06-01

    Full Text Available Purpose. To develop a diagnostic complex meeting the criteria and requirements for carrying out accelerated reliability test and realizing the basic modes of electric machines operation and performance of the posed problems necessary in the process of such test. Methodology. To determine and forecast the indices of electric machines reliability in accordance with the statistic data of repair plants we have conditionally divided them into structural parts that are most likely to fail. We have preliminarily assessed the state of each of these parts, which includes revelation of faults and deviations of technical and geometric parameters. We have determined the analyzed electric machine controlled parameters used for assessment of quantitative characteristics of reliability of these parts and electric machines on the whole. Results. As a result of the research, we have substantiated the structure of a computerized complex for electric machines reliability test. It allows us to change thermal and vibration actions without violation of the physics of the processes of aging and wearing of the basic structural parts and elements material. The above mentioned makes it possible to considerably reduce time spent on carrying out electric machines reliability tests and improve trustworthiness of the data obtained as a result of their performance. Originality. A special feature of determination of the controlled parameters consists in removal of vibration components in the idle mode and after disconnection of the analyzed electric machine from the power supply with the aim of singling out the vibration electromagnetic component, fixing the degree of sparking and bend of the shaft by means of phototechnique and local determination of structural parts temperature provided by corresponding location of thermal sensors. Practical value. We have offered a scheme of location of thermal and vibration sensors, which allows improvement of parameters measuring accuracy

  3. Reliability of provocative tests of motion sickness susceptibility

    Science.gov (United States)

    Calkins, D. S.; Reschke, M. F.; Kennedy, R. S.; Dunlop, W. P.

    1987-01-01

    Test-retest reliability values were derived from motion sickness susceptibility scores obtained from two successive exposures to each of three tests: (1) Coriolis sickness sensitivity test; (2) staircase velocity movement test; and (3) parabolic flight static chair test. The reliability of the three tests ranged from 0.70 to 0.88. Normalizing values from predictors with skewed distributions improved the reliability.

  4. Investigation of reliability attributes and accelerated stress factors on terrestrial solar cells

    Science.gov (United States)

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

    1980-04-01

    Three tasks were undertaken to investigate reliability attributes of terrestrial solar cells: (1) a study of the electrical behavior of cells in the second (reverse) quadrant; (2) the accelerated stress testing of three new state-of-the-art cells; and (3) the continued bias-temperature testing of four block 2 type silicon cells at 78 C and 135 C. Electrical characteristics measured in the second quadrant were determined to be a function of the cell's thermal behavior with breakdown depending on the initiation of localized heating. This implied that high breakdown cells may be more fault tolerant when forced to operate in the second quadrant, a result contrary to conventional thinking. The accelerated stress tests used in the first (power) quadrant were bias-temperature, bias-temperature-humidity, temperature-humidity, thermal shock, and thermal cycle. The new type cells measured included an EFG cell, a polycrystalline cell, and a Czochralski cell. Significant differences in the response to the various tests were observed between cell types. A microprocessed controlled, short interval solar cell tester was designed and construction initiated on a prototype.

  5. Commissioning of the Ground Test Accelerator RFQ

    International Nuclear Information System (INIS)

    Johnson, K.F.; Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Brown, S.; Connolly, R.; Garnett, R.; Gilpatrick, J.D.; Guy, F.W.; Ingalls, W.B.; Little, C.; Lohson, R.A.; Lloyd, S.; Neuschaefer, G.; Power, J.; Saadatmand, K.; Sandoval, D.P.; Stevens, R.R.; Vaughn, G.; Wadlinger, E.A.; Weiss, R.; Yuan, V.

    1992-01-01

    The Ground Test Accelerator (GTA) has the objective of verifying much of the technology (physics and engineering) required for producing high-brightness, high-current H - beams. GTA commissioning is staged to verify the beam dynamics design of each major accelerator component as it is brought on-line. The commissioning stages are the 35 key H - injector, the 2.5 MeV Radio Frequency Quadrupole (RFQ), the Intertank Matching Section (IMS), the 3.2 MeV first 2βγ Drift Tube Linac (DTL-1) module, the 8.7 MeV 2βγ DTL (modules 1--5), and the 24 MeV GTA; all 10 DTL modules. Commissioning results from the RFQ beam experiments will be presented along with comparisons to simulations

  6. Commissioning of the ground test accelerator RFQ

    International Nuclear Information System (INIS)

    Johnson, K.F.; Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Brown, S.; Garnott, R.; Gilpatrick, J.D.; Guy, F.W.; Ingalls, W.B.; Little, C.; Lohsen, R.A.; Lloyd, S.; Neuschaefer, G.; Power, J.; Sandoval, D.P.; Saadatmand, K.; Stevens, R.R.Jr.; Vaughn, G.; Wadlinger, E.A.; Yuan, V.; Connolly, R.; Weiss, R.

    1992-01-01

    The Ground Test Accelerator (GTA) has the objective of verifying much of the technology (physics and engineering) required for producing high-brightness, high-current H - beams. GTA commissioning is staged to verify the beam dynamics design of each major accelerator component as it is brought on line. The commissioning stages are the 35-keV H - injector, the 2.5-MeV radio-frequency quadrupole (RFQ), the intertank matching section (IMS), the 3.2-MeV first 2-βλ drift tube linac (DTL-1) module, the 8.7-MeV 2-βλDTL (modules 1-5), and the 24-MeV GTA (all 10 DTL modules). Commissioning results from the RFQ beam experiments are presented along with comparisons with simulations. (Author) 8 refs., 9 figs

  7. Ultra-accelerated natural sunlight exposure testing

    Science.gov (United States)

    Jorgensen, Gary J.; Bingham, Carl; Goggin, Rita; Lewandowski, Allan A.; Netter, Judy C.

    2000-06-13

    Process and apparatus for providing ultra accelerated natural sunlight exposure testing of samples under controlled weathering without introducing unrealistic failure mechanisms in exposed materials and without breaking reciprocity relationships between flux exposure levels and cumulative dose that includes multiple concurrent levels of temperature and relative humidity at high levels of natural sunlight comprising: a) concentrating solar flux uniformly; b) directing the controlled uniform sunlight onto sample materials in a chamber enclosing multiple concurrent levels of temperature and relative humidity to allow the sample materials to be subjected to accelerated irradiance exposure factors for a sufficient period of time in days to provide a corresponding time of about at least a years worth of representative weathering of the sample materials.

  8. Metal and elastomer seal tests for accelerator applications

    International Nuclear Information System (INIS)

    Welch, K.M.; McIntyre, G.T.; Tuozzolo, J.E.; Skelton, R.; Pate, D.J.; Gill, S.M.

    1989-01-01

    The vacuum system of the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory has more than a thousand metal vacuum seals. Also, numerous elastomer seals are used throughout the AGS to seal large beam component chambers. An accelerator upgrade program is being implemented to reduce the AGS operating pressure by x100 and improve the reliability of the vacuum system. This paper describes work in progress on metal and elastomer vacuum seals to help meet those two objectives. Tests are reported on the sealing properties of a variety of metal seals used on different sealing surfaces. Results are also given on reversible sorption properties of certain elastomers. 16 refs., 6 figs., 4 tabs

  9. Reliability Models Applied to a System of Power Converters in Particle Accelerators

    OpenAIRE

    Siemaszko, D; Speiser, M; Pittet, S

    2012-01-01

    Several reliability models are studied when applied to a power system containing a large number of power converters. A methodology is proposed and illustrated in the case study of a novel linear particle accelerator designed for reaching high energies. The proposed methods result in the prediction of both reliability and availability of the considered system for optimisation purposes.

  10. Prediction of software operational reliability using testing environment factors

    International Nuclear Information System (INIS)

    Jung, Hoan Sung; Seong, Poong Hyun

    1995-01-01

    For many years, many researches have focused on the quantification of software reliability and there are many models developed to quantify software reliability. Most software reliability models estimate the reliability with the failure data collected during the test assuming that the test environments well represent the operation profile. The experiences show that the operational reliability is higher than the test reliability User's interest is on the operational reliability rather than on the test reliability, however. With the assumption that the difference in reliability results from the change of environment, testing environment factors comprising the aging factor and the coverage factor are defined in this study to predict the ultimate operational reliability with the failure data. It is by incorporating test environments applied beyond the operational profile into testing environment factors. The application results are close to the actual data

  11. Reliability

    OpenAIRE

    Condon, David; Revelle, William

    2017-01-01

    Separating the signal in a test from the irrelevant noise is a challenge for all measurement. Low test reliability limits test validity, attenuates important relationships, and can lead to regression artifacts. Multiple approaches to the assessment and improvement of reliability are discussed. The advantages and disadvantages of several different approaches to reliability are considered. Practical advice on how to assess reliability using open source software is provided.

  12. A study of operational and testing reliability in software reliability analysis

    International Nuclear Information System (INIS)

    Yang, B.; Xie, M.

    2000-01-01

    Software reliability is an important aspect of any complex equipment today. Software reliability is usually estimated based on reliability models such as nonhomogeneous Poisson process (NHPP) models. Software systems are improving in testing phase, while it normally does not change in operational phase. Depending on whether the reliability is to be predicted for testing phase or operation phase, different measure should be used. In this paper, two different reliability concepts, namely, the operational reliability and the testing reliability, are clarified and studied in detail. These concepts have been mixed up or even misused in some existing literature. Using different reliability concept will lead to different reliability values obtained and it will further lead to different reliability-based decisions made. The difference of the estimated reliabilities is studied and the effect on the optimal release time is investigated

  13. Some practical observations on the accelerated testing of Nickel-Cadmium Cells

    Science.gov (United States)

    Mcdermott, P. P.

    1979-01-01

    A large scale test of 6.0 Ah Nickel-Cadmium Cells conducted at the Naval Weapons Support Center, Crane, Indiana has demonstrated a methodology for predicting battery life based on failure data from cells cycled in an accelerated mode. After examining eight variables used to accelerate failure, it was determined that temperature and depth of discharge were the most reliable and efficient parameters for use in accelerating failure and for predicting life.

  14. Acquisition of reliable vacuum hardware for large accelerator systems

    International Nuclear Information System (INIS)

    Welch, K.M.

    1996-01-01

    Credible and effective communications prove to be the major challenge in the acquisition of reliable vacuum hardware. Technical competence is necessary but not sufficient. We must effectively communicate with management, sponsoring agencies, project organizations, service groups, staff and with vendors. Most of Deming's 14 quality assurance tenets relate to creating an enlightened environment of good communications. All projects progress along six distinct, closely coupled, dynamic phases; all six phases are in a state of perpetual change. These phases and their elements are discussed, with emphasis given to the acquisition phase and its related vocabulary. (author)

  15. Reliability of solid-state lighting electrical drivers subjected to WHTOL accelerated aging

    Energy Technology Data Exchange (ETDEWEB)

    Lall, Pradeep; Sakalauku, Peter; Davis, Lynn

    2014-05-27

    An investigation of a solid-state lighting (SSL) luminaire with the focus on the electronic driver which has been exposed to a standard wet hot temperature operating life (WHTOL) of 85% RH and 85°C in order to assess reliability of prolonged exposer to a harsh environment has been conducted. SSL luminaires are beginning introduced as head lamps in some of today's luxury automobiles and may also be fulfilling a variety of important outdoor applications such as overhead street lamps, traffic signals and landscape lighting. SSL luminaires in these environments are almost certain to encounter excessive moisture from humidity and high temperatures for a persistent period of time. The lack of accelerated test methods for LEDs to assess long-term reliability prior to introduction into the marketplace, a need for SSL physics based PHM modeling indicators for assessment and prediction of LED life, as well as the U.S. Department of Energy's R&D roadmap to replace todays lighting with SSL luminaires makes it important to increase the understanding of the reliability of SSL devices, specifically, in harsh environment applications. In this work, a set of SSL electrical drivers were investigated to determine failure mechanisms that occur during prolonged harsh environment applications. Each driver consists of four aluminum electrolytic capacitors (AECs) of three different types and was considered the weakest component inside the SSL electrical driver. The reliability of the electrical driver was assessed by monitoring the change in capacitance and the change in equivalent series resistance for each AEC, as well as monitoring the luminous flux of the SSL luminaire or the output of the electrical driver. The luminous flux of a pristine SSL electrical driver was also monitored in order to detect minute changes in the electrical drivers output and to aid in the investigation of the SSL luminaires reliability. The failure mechanisms of the electrical drivers have been

  16. Accelerated Leach Test(s) Program: Annual report

    International Nuclear Information System (INIS)

    Dougherty, D.R.; Pietrzak, R.F.; Fuhrmann, M.; Colombo, P.

    1986-09-01

    A computerized data base of LLW leaching data has been developed. Long-term tests on portland cement, bitumen and vinyl ester-styrene (VES) polymer waste forms containing simulated wastes are underway which are designed to identify and evaluate factors that accelerate leaching without changing the mechanisms

  17. Accelerated Performance Testing on the 2006 NCAT Pavement Test Track

    Science.gov (United States)

    2009-12-01

    The original National Center for Asphalt Technology (NCAT) Pavement Test Track was built in 2000 in Opelika, Alabama where it has served as a state-of-the-art, full-scale, closed-loop accelerated loading facility. The construction, operation, and res...

  18. An accelerator controls network designed for reliability and flexibility

    International Nuclear Information System (INIS)

    McDowell, W. P.; Sidorowicz, K. V.

    1997-01-01

    The APS accelerator control system is a typical modern system based on the standard control system model, which consists of operator interfaces to a network and computer-controlled interfaces to hardware. The network provides a generalized communication path between the host computers, operator workstations, input/output crates, and other hardware that comprise the control system. The network is an integral part of all modern control systems and network performance will determine many characteristics of a control system. This paper describes the methods used to provide redundancy for various network system components as well as methods used to provide comprehensive monitoring of this network. The effect of archiving tens of thousands of data points on a regular basis and the effect on the controls network will be discussed. Metrics are provided on the performance of the system under various conditions

  19. Reliability of non-destructive testing methods

    International Nuclear Information System (INIS)

    Broekhoven, M.J.G.

    1988-01-01

    This contribution regards the results of an evaluation of the reliability of radiography (X-rays and gamma-rays), manual-, and mechanized/automated ultrasonic examination by generally accepted codes/rules, with respect to detection, characterization and sizing/localization of defects. The evaluation is based on the results of examinations, by a number of teams, of 30 test plates, 30 and 50 mm thickness, containing V,U, X and K-shaped welds each containing several types of imperfections (211) in total) typical for steel arc fusion welding, such as porosity, inclusions, lack of fusion or penetration and cracks. Besides, some results are presented obtained from research on advanced UT-techniques, viz. the time-of-flight-diffraction and flaw-tip deflection technique. (author)

  20. Reliability of non-destructive testing methods

    Energy Technology Data Exchange (ETDEWEB)

    Broekhoven, M J.G. [Ministry of Social Affairs, (Netherlands)

    1988-12-31

    This contribution regards the results of an evaluation of the reliability of radiography (X-rays and gamma-rays), manual-, and mechanized/automated ultrasonic examination by generally accepted codes/rules, with respect to detection, characterization and sizing/localization of defects. The evaluation is based on the results of examinations, by a number of teams, of 30 test plates, 30 and 50 mm thickness, containing V,U, X and K-shaped welds each containing several types of imperfections (211) in total) typical for steel arc fusion welding, such as porosity, inclusions, lack of fusion or penetration and cracks. Besides, some results are presented obtained from research on advanced UT-techniques, viz. the time-of-flight-diffraction and flaw-tip deflection technique. (author). 4 refs.

  1. Laboratory Test of Newton's Second Law for Small Accelerations

    International Nuclear Information System (INIS)

    Gundlach, J. H.; Schlamminger, S.; Spitzer, C. D.; Choi, K.-Y.; Woodahl, B. A.; Coy, J. J.; Fischbach, E.

    2007-01-01

    We have tested the proportionality of force and acceleration in Newton's second law, F=ma, in the limit of small forces and accelerations. Our tests reach well below the acceleration scales relevant to understanding several current astrophysical puzzles such as the flatness of galactic rotation curves, the Pioneer anomaly, and the Hubble acceleration. We find good agreement with Newton's second law at accelerations as small as 5x10 -14 m/s 2

  2. Acquisition of reliable vacuum hardware for large accelerator systems

    International Nuclear Information System (INIS)

    Welch, K.M.

    1995-01-01

    Credible and effective communications prove to be the major challenge in the acquisition of reliable vacuum hardware. Technical competence is necessary but not sufficient. The authors must effectively communicate with management, sponsoring agencies, project organizations, service groups, staff and with vendors. Most of Deming's 14 quality assurance tenants relate to creating an enlightened environment of good communications. All projects progress along six distinct, closely coupled, dynamic phases. All six phases are in a state of perpetual change. These phases and their elements are discussed, with emphasis given to the acquisition phase and its related vocabulary. Large projects require great clarity and rigor as poor communications can be costly. For rigor to be cost effective, it can't be pedantic. Clarity thrives best in a low-risk, team environment

  3. Induction accelerator test module for HIF

    International Nuclear Information System (INIS)

    Faltens, A.

    1991-04-01

    An induction linac test module suitable for investigating the drive requirements and the longitudinal coupling impedance of a high-power ion induction linac has been constructed by the Heavy Ion Fusion (HIF) group at LBL. The induction linac heavy ion driver for inertial confinement fusion (ICF) as presently envisioned uses multiple parallel beams which are transported in separate focusing channels but accelerated together in the induction modules. The resulting induction modules consequently have large beam apertures-1--2 meters in diameter- and correspondingly large outside diameters. The module geometry is related to a low-frequency ''gap capacity'' and high-frequency structural resonances, which are affected by the magnetic core loading and the module pulser impedance. A description of the test module and preliminary results are presented. 3 figs

  4. Reliability analysis applied to structural tests

    Science.gov (United States)

    Diamond, P.; Payne, A. O.

    1972-01-01

    The application of reliability theory to predict, from structural fatigue test data, the risk of failure of a structure under service conditions because its load-carrying capability is progressively reduced by the extension of a fatigue crack, is considered. The procedure is applicable to both safe-life and fail-safe structures and, for a prescribed safety level, it will enable an inspection procedure to be planned or, if inspection is not feasible, it will evaluate the life to replacement. The theory has been further developed to cope with the case of structures with initial cracks, such as can occur in modern high-strength materials which are susceptible to the formation of small flaws during the production process. The method has been applied to a structure of high-strength steel and the results are compared with those obtained by the current life estimation procedures. This has shown that the conventional methods can be unconservative in certain cases, depending on the characteristics of the structure and the design operating conditions. The suitability of the probabilistic approach to the interpretation of the results from full-scale fatigue testing of aircraft structures is discussed and the assumptions involved are examined.

  5. Influences on and Limitations of Classical Test Theory Reliability Estimates.

    Science.gov (United States)

    Arnold, Margery E.

    It is incorrect to say "the test is reliable" because reliability is a function not only of the test itself, but of many factors. The present paper explains how different factors affect classical reliability estimates such as test-retest, interrater, internal consistency, and equivalent forms coefficients. Furthermore, the limits of classical test…

  6. Accelerated Physical Stability Testing of Amorphous Dispersions.

    Science.gov (United States)

    Mehta, Mehak; Suryanarayanan, Raj

    2016-08-01

    The goal was to develop an accelerated physical stability testing method of amorphous dispersions. Water sorption is known to cause plasticization and may accelerate drug crystallization. In an earlier investigation, it was observed that both the increase in mobility and decrease in stability in amorphous dispersions was explained by the "plasticization" effect of water (Mehta et al. Mol. Pharmaceutics 2016, 13 (4), 1339-1346). In this work, the influence of water concentration (up to 1.8% w/w) on the correlation between mobility and crystallization in felodipine dispersions was investigated. With an increase in water content, the α-relaxation time as well as the time for 1% w/w felodipine crystallization decreased. The relaxation times of the systems, obtained with different water concentration, overlapped when the temperature was scaled (Tg/T). The temperature dependencies of the α-relaxation time as well as the crystallization time were unaffected by the water concentration. Thus, the value of the coupling coefficient, up to a water concentration of 1.8% w/w, was approximately constant. Based on these findings, the use of "water sorption" is proposed to build predictive models for crystallization in slow crystallizing dispersions.

  7. Hurricane Isabel gives accelerators a severe test

    International Nuclear Information System (INIS)

    Swapan Chattopadhyay

    2004-01-01

    Hurricane Isabel was at category five--the most violent on the Saffir-Simpson scale of hurricane strength--when it began threatening the central Atlantic seaboard of the US. Over the course of several days, precautions against the extreme weather conditions were taken across the Jefferson Lab site in south-east Virginia. On 18 September 2003, when Isabel struck North Carolina's Outer Banks and moved northward, directly across the region around the laboratory, the storm was still quite destructive, albeit considerably reduced in strength. The flood surge and trees felled by wind substantially damaged or even devastated buildings and homes, including many belonging to Jefferson Lab staff members. For the laboratory itself, Isabel delivered an unplanned and severe challenge in another form: a power outage that lasted nearly three-and-a-half days, and which severely tested the robustness of Jefferson Lab's two superconducting machines, the Continuous Electron Beam Accelerator Facility (CEBAF) and the superconducting radiofrequency ''driver'' accelerator of the laboratory's free-electron laser. Robustness matters greatly for science at a time when microwave superconducting linear accelerators (linacs) are not only being considered, but in some cases already being built for projects such as neutron sources, rare-isotope accelerators, innovative light sources and TeV-scale electron-positron linear colliders. Hurricane Isabel interrupted a several-week-long maintenance shutdown of CEBAF, which serves nuclear and particle physics and represents the world's pioneering large-scale implementation of superconducting radiofrequency (SRF) technology. The racetrack-shaped machine is actually a pair of 500-600 MeV SRF linacs interconnected by recirculation arc beamlines. CEBAF delivers simultaneous beams at up to 6 GeV to three experimental halls. An imminent upgrade will double the energy to 12 GeV and add an extra hall for ''quark confinement'' studies. On a smaller scale

  8. Accelerated Strength Testing of Thermoplastic Composites

    Science.gov (United States)

    Reeder, J. R.; Allen, D. H.; Bradley, W. L.

    1998-01-01

    Constant ramp strength tests on unidirectional thermoplastic composite specimens oriented in the 90 deg. direction were conducted at constant temperatures ranging from 149 C to 232 C. Ramp rates spanning 5 orders of magnitude were tested so that failures occurred in the range from 0.5 sec. to 24 hrs. (0.5 to 100,000 MPa/sec). Below 204 C, time-temperature superposition held allowing strength at longer times to be estimated from strength tests at shorter times but higher temperatures. The data indicated that a 50% drop in strength might be expected for this material when the test time is increased by 9 orders of magnitude. The shift factors derived from compliance data applied well to the strength results. To explain the link between compliance and strength, a viscoelastic fracture model was investigated. The model, which used compliance as input, was found to fit the strength data only if the critical fracture energy was allowed to vary with temperature reduced stress rate. This variation in the critical parameter severely limits its use in developing a robust time-dependent strength model. The significance of this research is therefore seen as providing both the indication that a more versatile acceleration method for strength can be developed and the evidence that such a method is needed.

  9. Stripline kicker for integrable optics test accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Antipov, Sergey A.; Didenko, Alexander; Lebedev, Valeri; Valishev, Alexander

    2016-06-30

    We present a design of a stripline kicker for Integrable Optics Test Accelerator (IOTA). For its experimental program IOTA needs two full-aperture kickers, capable to create an arbitrary controllable kick in 2D. For that reason their strengths are variable in a wide range of amplitudes up to 16 mrad, and the pulse length 100 ns is less than a revolution period for electrons. In addition, the kicker should have a physical aperture of 40 mm for a proposed operation with proton beam, and an outer size of 70 mm to fit inside existing quadrupole magnets to save space in the ring. Computer simulations using CST Microwave Studio show high field uniformity and wave impedance close to 50 {\\Omega}.

  10. Accelerated Comparative Fatigue Strength Testing of Belt Adhesive Joints

    Science.gov (United States)

    Bajda, Miroslaw; Blazej, Ryszard; Jurdziak, Leszek

    2017-12-01

    Belt joints are the weakest link in the serial structure that creates an endless loop of spliced belt segments. This affects not only the lower strength of adhesive joints of textile belts in comparison to vulcanized splices, but also the replacement of traditional glues to more ecological but with other strength parameters. This is reflected in the lowered durability of adhesive joints, which in underground coal mines is nearly twice shorter than the operating time of belts. Vulcanized splices require high precision in performance, they need long time to achieve cross-linking of the friction mixture and, above all, they require specialized equipment (vulcanization press) which is not readily available and often takes much time to be delivered down, which means reduced mining output or even downtime. All this reduces the reliability and durability of adhesive joints. In addition, due to the consolidation on the Polish coal market, mines are joined into large economic units serviced by a smaller number of processing plants. The consequence is to extend the transport routes downstream and increase reliability requirements. The greater number of conveyors in the chain reduces reliability of supply and increases production losses. With high fixed costs of underground mines, the reduction in mining output is reflected in the increase in unit costs, and this at low coal prices on the market can mean substantial losses for mines. The paper describes the comparative study of fatigue strength of shortened samples of adhesive joints conducted to compare many different variants of joints (various adhesives and materials). Shortened samples were exposed to accelerated fatigue in the usually long-lasting dynamic studies, allowing more variants to be tested at the same time. High correlation between the results obtained for shortened (100 mm) and traditional full-length (3×250 mm) samples renders accelerated tests possible.

  11. First Assessment of Reliability Data for the LHC Accelerator and Detector Cryogenic System Components

    CERN Document Server

    Perinic, G; Alonso-Canella, I; Balle, C; Barth, K; Bel, J F; Benda, V; Bremer, J; Brodzinski, K; Casas-Cubillos, J; Cuccuru, G; Cugnet, M; Delikaris, D; Delruelle, N; Dufay-Chanat, L; Fabre, C; Ferlin, G; Fluder, C; Gavard, E; Girardot, R; Haug, F; Herblin, L; Junker, S; Klabi , T; Knoops, S; Lamboy, J P; Legrand, D; Metselaar, J; Park, A; Perin, A; Pezzetti, M; Penacoba-Fernandez, G; Pirotte, O; Rogez, E; Suraci, A; Stewart, L; Tavian, L J; Tovar-Gonzalez, A; Van Weelderen, R; Vauthier, N; Vullierme, B; Wagner, U

    2012-01-01

    The Large Hadron Collider (LHC) cryogenic system comprises eight independent refrigeration and distribution systems that supply the eight 3.3 km long accelerator sectors with cryogenic refrigeration power as well as four refrigeration systems for the needs of the detectors ATLAS and CMS. In order to ensure the highest possible reliability of the installations, it is important to apply a reliability centred approach for the maintenance. Even though large scale cryogenic refrigeration exists since the mid 20th century, very little third party reliability data is available today. CERN has started to collect data with its computer aided maintenance management system (CAMMS) in 2009, when the accelerator has gone into normal operation. This paper presents the reliability observations from the operation and the maintenance side, as well as statistical data collected by the means of the CAMMS system.

  12. Acceleration test with mixed higher harmonics in HIMAC

    International Nuclear Information System (INIS)

    Kanazawa, M.; Sugiura, A.; Misu, T.

    2004-01-01

    In HIMAC synchrotron, beam tests with a magnetic ally loaded cavity have been performed. This cavity has very low Q-value of about 0.5, and can be added higher harmonics with fundamental acceleration frequency. In our tested system for higher harmonics, wave form of a DDS (Direct Digital Synthesizer) can be rewrite, and arbitrary wave form can be used for beam acceleration. In the beam test, second and third harmonic wave were added on the fundamental acceleration frequency, and increases of the accelerated beam intensity have been achieved. In this paper, results of the beam test and the acceleration system are presented. (author)

  13. ACSC Indicator: testing reliability for hypertension.

    Science.gov (United States)

    Walker, Robin L; Ghali, William A; Chen, Guanmin; Khalsa, Tej K; Mangat, Birinder K; Campbell, Norm R C; Dixon, Elijah; Rabi, Doreen; Jette, Nathalie; Dhanoa, Robyn; Quan, Hude

    2017-06-26

    With high-quality community-based primary care, hospitalizations for ambulatory care sensitive conditions (ACSC) are considered avoidable. The purpose of this study was to test the inter-physician reliability of judgments of avoidable hospitalizations for one ACSC, uncomplicated hypertension, derived from medical chart review. We applied the Canadian Institute for Health Information's case definition to obtain a random sample of patients who had an ACSC hospitalization for uncomplicated hypertension in Calgary, Alberta. Medical chart review was conducted by three experienced internal medicine specialists. Implicit methods were used to judge avoidability of hospitalization using a validated 5-point scale. There was poor agreement among three physicians raters when judging the avoidability of 82 ACSC hospitalizations for uncomplicated hypertension (κ = 0.092). The κ also remained low when assessing agreement between raters 1 and 3 (κ = 0.092), but the κ was lower (less than chance agreement) for raters 1 and 2 (κ = -0.119) and raters 2 and 3 (κ = -0.008). When the 5-point scale was dichotomized, there was fair agreement among three raters (κ = 0.217). The proportion of ACSC hospitalizations for uncomplicated hypertension that were rated as avoidable was 32.9%, 6.1% and 26.8% for raters 1, 2, and 3, respectively. This study found a low proportion of ACSC hospitalization were rated as avoidable, with poor to fair agreement of judgment between physician raters. This suggests that the validity and utility of this health indicator is questionable. It points to a need to abandon the use of ACSC entirely; or alternatively to work on the development of explicit criteria for judging avoidability of hospitalization for ACSC such as hypertension.

  14. Prediction of software operational reliability using testing environment factor

    International Nuclear Information System (INIS)

    Jung, Hoan Sung

    1995-02-01

    Software reliability is especially important to customers these days. The need to quantify software reliability of safety-critical systems has been received very special attention and the reliability is rated as one of software's most important attributes. Since the software is an intellectual product of human activity and since it is logically complex, the failures are inevitable. No standard models have been established to prove the correctness and to estimate the reliability of software systems by analysis and/or testing. For many years, many researches have focused on the quantification of software reliability and there are many models developed to quantify software reliability. Most software reliability models estimate the reliability with the failure data collected during the test assuming that the test environments well represent the operation profile. User's interest is on the operational reliability rather than on the test reliability, however. The experiences show that the operational reliability is higher than the test reliability. With the assumption that the difference in reliability results from the change of environment, testing environment factor comprising the aging factor and the coverage factor are defined in this work to predict the ultimate operational reliability with the failure data. It is by incorporating test environments applied beyond the operational profile into testing environment factor Test reliability can also be estimated with this approach without any model change. The application results are close to the actual data. The approach used in this thesis is expected to be applicable to ultra high reliable software systems that are used in nuclear power plants, airplanes, and other safety-critical applications

  15. Accelerated testing for cosmic soft-error rate

    International Nuclear Information System (INIS)

    Ziegler, J.F.; Muhlfeld, H.P.; Montrose, C.J.; Curtis, H.W.; O'Gorman, T.J.; Ross, J.M.

    1996-01-01

    This paper describes the experimental techniques which have been developed at IBM to determine the sensitivity of electronic circuits to cosmic rays at sea level. It relates IBM circuit design and modeling, chip manufacture with process variations, and chip testing for SER sensitivity. This vertical integration from design to final test and with feedback to design allows a complete picture of LSI sensitivity to cosmic rays. Since advanced computers are designed with LSI chips long before the chips have been fabricated, and the system architecture is fully formed before the first chips are functional, it is essential to establish the chip reliability as early as possible. This paper establishes techniques to test chips that are only partly functional (e.g., only 1Mb of a 16Mb memory may be working) and can establish chip soft-error upset rates before final chip manufacturing begins. Simple relationships derived from measurement of more than 80 different chips manufactured over 20 years allow total cosmic soft-error rate (SER) to be estimated after only limited testing. Comparisons between these accelerated test results and similar tests determined by ''field testing'' (which may require a year or more of testing after manufacturing begins) show that the experimental techniques are accurate to a factor of 2

  16. Research on the Reliability Testing of Electrical Automation Control Equipment

    OpenAIRE

    Yongjie Luo

    2014-01-01

    According to the author’s many years’ work experience, this paper first discusses the concepts of electrical automation control equipment reliability testing, and then analyzes the test method of electrical automation control equipment reliability testing, finally, on this basis, this article discusses how to determine the reliability test method of electrical automation control equipment. Results of this study will provide a useful reference for electrical automation control equipment reliab...

  17. A standard for test reliability in group research.

    Science.gov (United States)

    Ellis, Jules L

    2013-03-01

    Many authors adhere to the rule that test reliabilities should be at least .70 or .80 in group research. This article introduces a new standard according to which reliabilities can be evaluated. This standard is based on the costs or time of the experiment and of administering the test. For example, if test administration costs are 7 % of the total experimental costs, the efficient value of the reliability is .93. If the actual reliability of a test is equal to this efficient reliability, the test size maximizes the statistical power of the experiment, given the costs. As a standard in experimental research, it is proposed that the reliability of the dependent variable be close to the efficient reliability. Adhering to this standard will enhance the statistical power and reduce the costs of experiments.

  18. Accelerated Leach Test(s) Program. Annual report

    International Nuclear Information System (INIS)

    Dougherty, D.R.; Fuhrmann, M.; Colombo, P.

    1985-09-01

    This report summarizes the work performed for the Accelerated Leach Test(s) Program at Brookhaven National Laboratory in Fiscal Year 1985 under the sponsorship of the US Department of Energy's Low-Level Waste Management Program (LLWMP). Programmatic activities were concentrated in three areas, as listed and described in the following paragraphs. (1) A literature survey of reported leaching mechanisms, available mathematical models and factors that affect leaching of LLW forms has been compiled. Mechanisms which have been identified include diffusion, dissolution, ion exchange, corrosion and surface effects. Available mathematical models are based on diffusion as the predominant mechanism. Although numerous factors that affect leaching have been identified, they have been conveniently categorized as factors related to the entire leaching system, to the leachant or to the waste form. A report has been published on the results of this literature survey. (2) A computerized data base of LLW leaching data and mathematical models is being developed. The data are being used for model evaluation by curve fitting and statistical analysis according to standard procedures of statistical quality control. (3) Long-term tests on portland cement, bitumen and vinyl ester-styrene (VES) polymer waste forms are underway which are designed to identify and evaluate factors that accelerate leaching without changing the mechanisms. Results on the effect of temperature on leachability indicate that the leach rates of cement and VES waste forms increase with increasing temperature, whereas, the leach rate of bitumen is little affected

  19. A Bayesian Optimal Design for Sequential Accelerated Degradation Testing

    Directory of Open Access Journals (Sweden)

    Xiaoyang Li

    2017-07-01

    Full Text Available When optimizing an accelerated degradation testing (ADT plan, the initial values of unknown model parameters must be pre-specified. However, it is usually difficult to obtain the exact values, since many uncertainties are embedded in these parameters. Bayesian ADT optimal design was presented to address this problem by using prior distributions to capture these uncertainties. Nevertheless, when the difference between a prior distribution and actual situation is large, the existing Bayesian optimal design might cause some over-testing or under-testing issues. For example, the implemented ADT following the optimal ADT plan consumes too much testing resources or few accelerated degradation data are obtained during the ADT. To overcome these obstacles, a Bayesian sequential step-down-stress ADT design is proposed in this article. During the sequential ADT, the test under the highest stress level is firstly conducted based on the initial prior information to quickly generate degradation data. Then, the data collected under higher stress levels are employed to construct the prior distributions for the test design under lower stress levels by using the Bayesian inference. In the process of optimization, the inverse Gaussian (IG process is assumed to describe the degradation paths, and the Bayesian D-optimality is selected as the optimal objective. A case study on an electrical connector’s ADT plan is provided to illustrate the application of the proposed Bayesian sequential ADT design method. Compared with the results from a typical static Bayesian ADT plan, the proposed design could guarantee more stable and precise estimations of different reliability measures.

  20. Operation of the Brookhaven national laboratory accelerator test facility

    International Nuclear Information System (INIS)

    Batchelor, K.; Ben-Zvi, I.; Botke, I.; Chou, T.S.; Fernow, R.; Fischer, J.; Fisher, A.; Gallardo, J.; Ingold, G.; Malone, R.; Palmer, R.; Parsa, Z.; Pogorelsky, I.; Rogers, J.; Sheehan, J.; Srinivasan-Rao, T.; Tsang, T.; Ulc, S.; Van Steenbergen, A.; Wang, X.J.; Woodle, M.; Yu, L.H.

    1992-01-01

    Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program. (Author) 5 refs., 4 figs., tab

  1. Operation of the Brookhaven National Laboratory Accelerator Test Facility

    International Nuclear Information System (INIS)

    Batchelor, K.; Ben-Zvi, I.; Botke, I.; Chou, T.S.; Fernow, R.; Fischer, J.; Fisher, A.; Gallardo, J.; Ingold, G.; Malone, R.; Palmer, R.; Parsa, Z.; Pogorelsky, I.; Rogers, J.; Sheehan, J.; Srinivasan-Rao, T.; Tsang, T.; Ulc, S.; van Steenbergen, A.; Wang, X.J.; Woodle, M.; Yu, L.H.

    1992-01-01

    Early operation of the 50 MeV high brightness electron linac of the Accelerator Test Facility is described along with experimental data. This facility is designed to study new linear acceleration techniques and new radiation sources based on linacs in combination with free electron lasers. The accelerator utilizes a photo-excited, metal cathode, radio frequency electron gun followed by two travelling wave accelerating sections and an Experimental Hall for the study program

  2. Accelerated oxygen-induced retinopathy is a reliable model of ischemia-induced retinal neovascularization.

    Science.gov (United States)

    Villacampa, Pilar; Menger, Katja E; Abelleira, Laura; Ribeiro, Joana; Duran, Yanai; Smith, Alexander J; Ali, Robin R; Luhmann, Ulrich F; Bainbridge, James W B

    2017-01-01

    Retinal ischemia and pathological angiogenesis cause severe impairment of sight. Oxygen-induced retinopathy (OIR) in young mice is widely used as a model to investigate the underlying pathological mechanisms and develop therapeutic interventions. We compared directly the conventional OIR model (exposure to 75% O2 from postnatal day (P) 7 to P12) with an alternative, accelerated version (85% O2 from P8 to P11). We found that accelerated OIR induces similar pre-retinal neovascularization but greater retinal vascular regression that recovers more rapidly. The extent of retinal gliosis is similar but neuroretinal function, as measured by electroretinography, is better maintained in the accelerated model. We found no systemic or maternal morbidity in either model. Accelerated OIR offers a safe, reliable and more rapid alternative model in which pre-retinal neovascularization is similar but retinal vascular regression is greater.

  3. Advanced Accelerator Test Facility (AATF) upgrade plan

    International Nuclear Information System (INIS)

    Gai, W.; Ho, C.; Konecny, R.

    1989-01-01

    We have successfully demonstrated the principles of wake-field acceleration using structures (cavity, dielectric) and plasmas as wake-field devices using the AATF at Argonne National Laboratory. Due to the limited driver electron pulse intensity and relative long pulse length, only modest accelerating gradients were observed. In order to study the wake field effects in much greater detail and demonstrate the feasibility of wake-field accelerator for high energy physics, we are considering construction of a laser photocathode injector on the existing 20 MeV Chem-Linac to produce very intense and short electron pulses. 10 refs., 5 figs

  4. Reliability Generalization of the Alcohol Use Disorder Identification Test.

    Science.gov (United States)

    Shields, Alan L.; Caruso, John C.

    2002-01-01

    Evaluated the reliability of scores from the Alcohol Use Disorders Identification Test (AUDIT; J. Sounders and others, 1993) in a reliability generalization study based on 17 empirical journal articles. Results show AUDIT scores to be generally reliable for basic assessment. (SLD)

  5. Validity and Reliability of the Arabic Token Test for Children

    Science.gov (United States)

    Alkhamra, Rana A.; Al-Jazi, Aya B.

    2016-01-01

    Background: The Token Test for Children (2nd edition) (TTFC) is a measure for assessing receptive language. In this study we describe the translation process, validity and reliability of the Arabic Token Test for Children (A-TTFC). Aims: The aim of this study is to translate, validate and establish the reliability of the Arabic Token Test for…

  6. Conceptualizing Essay Tests' Reliability and Validity: From Research to Theory

    Science.gov (United States)

    Badjadi, Nour El Imane

    2013-01-01

    The current paper on writing assessment surveys the literature on the reliability and validity of essay tests. The paper aims to examine the two concepts in relationship with essay testing as well as to provide a snapshot of the current understandings of the reliability and validity of essay tests as drawn in recent research studies. Bearing in…

  7. Construction of Valid and Reliable Test for Assessment of Students

    Science.gov (United States)

    Osadebe, P. U.

    2015-01-01

    The study was carried out to construct a valid and reliable test in Economics for secondary school students. Two research questions were drawn to guide the establishment of validity and reliability for the Economics Achievement Test (EAT). It is a multiple choice objective test of five options with 100 items. A sample of 1000 students was randomly…

  8. Test-retest reliability of the Work Ability Index questionnaire

    NARCIS (Netherlands)

    de Zwart, B. C. H.; Frings-Dresen, M. H. W.; Van Duivenbooden, J. C.

    2002-01-01

    The goal of the study was to assess the test-retest reliability of the Work Ability Index (WAI) questionnaire. Reliability was tested using a test-retest design with a 4 week interval between measurements. Valid data were collected among 97 elderly construction workers aged 40 years and older. We

  9. Sequential accelerated tests: Improving the correlation of accelerated tests to module performance in the field

    Science.gov (United States)

    Felder, Thomas; Gambogi, William; Stika, Katherine; Yu, Bao-Ling; Bradley, Alex; Hu, Hongjie; Garreau-Iles, Lucie; Trout, T. John

    2016-09-01

    DuPont has been working steadily to develop accelerated backsheet tests that correlate with solar panels observations in the field. This report updates efforts in sequential testing. Single exposure tests are more commonly used and can be completed more quickly, and certain tests provide helpful predictions of certain backsheet failure modes. DuPont recommendations for single exposure tests are based on 25-year exposure levels for UV and humidity/temperature, and form a good basis for sequential test development. We recommend a sequential exposure of damp heat followed by UV then repetitions of thermal cycling and UVA. This sequence preserves 25-year exposure levels for humidity/temperature and UV, and correlates well with a large body of field observations. Measurements can be taken at intervals in the test, although the full test runs 10 months. A second, shorter sequential test based on damp heat and thermal cycling tests mechanical durability and correlates with loss of mechanical properties seen in the field. Ongoing work is directed toward shorter sequential tests that preserve good correlation to field data.

  10. Virtual accelerator concept, implementation and preliminary test

    International Nuclear Information System (INIS)

    Uriot, D.; Duperrier, R.

    2006-05-01

    A virtual accelerator is the coupling of a simulation code with the control system of a real machine. 3 operating modes are considered. First, the monitoring mode in which any action on the control system has an impact on both real and virtual machines. This mode allows a direct comparison between simulation results and the real behaviour of the accelerator. Secondly, the flight simulation mode, this mode allows the accelerator operators to simulate the effect of any change in the parameters of the control system before transferring them to the real machine. The main advantage of this mode is to allow the assessment of operating procedures before implementing them on the real machine. The third mode is the automatic steering mode in which the simulation code assumes the reins of the control system of the real machine. This mode allows the making of complex and time-consuming adjustment procedures in an automatic way. TraceWin is a simulation code dedicated to the behaviour of charged-particle beams in a linear accelerator. TraceWin is consistent with the EPICS technology on which the control system of most accelerators is based. A virtual accelerator composed of the SILHI injector combined to the TraceWin code via the EPICS environment has showed its efficiency in the automatic steering mode. (A.C.)

  11. Reliability of two social cognition tests: The combined stories test and the social knowledge test.

    Science.gov (United States)

    Thibaudeau, Élisabeth; Cellard, Caroline; Legendre, Maxime; Villeneuve, Karèle; Achim, Amélie M

    2018-04-01

    Deficits in social cognition are common in psychiatric disorders. Validated social cognition measures with good psychometric properties are necessary to assess and target social cognitive deficits. Two recent social cognition tests, the Combined Stories Test (COST) and the Social Knowledge Test (SKT), respectively assess theory of mind and social knowledge. Previous studies have shown good psychometric properties for these tests, but the test-retest reliability has never been documented. The aim of this study was to evaluate the test-retest reliability and the inter-rater reliability of the COST and the SKT. The COST and the SKT were administered twice to a group of forty-two healthy adults, with a delay of approximately four weeks between the assessments. Excellent test-retest reliability was observed for the COST, and a good test-retest reliability was observed for the SKT. There was no evidence of practice effect. Furthermore, an excellent inter-rater reliability was observed for both tests. This study shows a good reliability of the COST and the SKT that adds to the good validity previously reported for these two tests. These good psychometrics properties thus support that the COST and the SKT are adequate measures for the assessment of social cognition. Copyright © 2018. Published by Elsevier B.V.

  12. Vehicle accelerated corrosion test procedures for automotive in Malaysia

    Directory of Open Access Journals (Sweden)

    Anuar Liza

    2017-01-01

    Full Text Available An accelerated corrosion test, known as proving ground accelerated test, is commonly performed by automotive manufacturers to evaluate the corrosion performance of a vehicle. The test combines corrosion and durability inputs to detect potential failures that may occur during in-service conditions. Currently, the test is conducted at an external test center overseas. Such test is aimed to simulate the effects of one year accelerated corrosion in severe corrosive environment of the north-east and south east of America. However, the test results obtained do not correlate with the actual corrosion conditions observed in the Malaysian market, which is likely attributed to the different test environment of the tropical climate of vehicles in service. Therefore, a vehicle accelerated corrosion test procedure that suits the Malaysian market is proposed and benchmarked with other global car manufacturers that have their own dedicated corrosion test procedure. In the present work, a test track is used as the corrosion test ground and consists of various types of roads for structural durability exposures. Corrosion related facilities like salt trough, mud trough and gravel road are constructed as addition to the existing facilities. The establishment of accelerated corrosion test facilities has contributed to the development of initial accelerated corrosion test procedure for the national car manufacturer. The corrosion exposure is monitored by fitting test coupons at the underbody of test vehicle using mass loss technique so that the desired corrosion rate capable of simulating the real time corrosion effects for its target market.

  13. Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing - Part 2

    Science.gov (United States)

    Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerome C.; Kolody, Mark R.

    2012-01-01

    Evaluation of metals to predict service life of metal-based structures in corrosive environments has long relied on atmospheric exposure test sites. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions similar to those of the corrosive environment. Their reliability to correlate to atmospheric exposure test results is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated corrosion testing has yet to be universally accepted as a useful tool in predicting the long-term service life of a metal, despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard, and their use is crucial, a method that correlates timescales from accelerated testing to atmospheric exposure would be very valuable. This paper presents work that began with the characterization of the atmospheric environment at the Kennedy Space Center (KSC) Beachside Corrosion Test Site. The chemical changes that occur on low carbon steel, during atmospheric and accelerated corrosion conditions, were investigated using surface chemistry analytical methods. The corrosion rates and behaviors of panels subjected to long-term and accelerated corrosion conditions, involving neutral salt fog and alternating seawater spray, were compared to identify possible timescale correlations between accelerated and long-term corrosion performance. The results, as well as preliminary findings on the correlation investigation, are presented.

  14. Standard Operating Procedure for Accelerated Corrosion Testing at ARL

    Science.gov (United States)

    2017-11-01

    ARL-TN-0855 ● NOV 2017 US Army Research Laboratory Standard Operating Procedure for Accelerated Corrosion Testing at ARL by... Corrosion Testing at ARL by Thomas A Considine Weapons and Materials Research Directorate, ARL Approved for public...November 2017 2. REPORT TYPE Technical Note 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Standard Operating Procedure for Accelerated

  15. Study on the correlation between long-term exposure tests and accelerated corrosion tests by the combined damage of salts

    International Nuclear Information System (INIS)

    Park, Sang Soon; Lee, Min Woo

    2014-01-01

    Interest in the durability assessment and structural performance has increased according to an increase of concrete structures in salt damage environment recent years. Reliable way ensuring the most accelerated corrosion test is a method of performing the rebar corrosion monitoring as exposed directly to the marine test site exposure. However, long-term exposure test has a disadvantage because of a long period of time. Therefore, many studies on reinforced concrete in salt damage environments have been developed as alternatives to replace this. However, accelerated corrosion test is appropriate to evaluate the critical chlorine concentration in the short term, but only accelerated test method, is not easy to get correct answer. Accuracy of correlation acceleration test depends on the period of the degree of exposure environments. Therefore, in this study, depending on the concrete mix material, by the test was performed on the basis of the composite degradation of the salt damage, and investigate the difference of corrosion initiation time of the rebar, and indoor corrosion time of the structure, of the marine environment of the actual environments were investigated. The correlation coefficient was derived in the experiment. Long-term exposure test was actually conducted in consideration of the exposure conditions submerged zone, splash zone and tidal zone. The accelerated corrosion tests were carried out by immersion conditions, and by the combined deterioration due to the carbonation and accelerated corrosion due to wet and dry condition

  16. Validity and Reliability of a Medicine Ball Explosive Power Test.

    Science.gov (United States)

    Stockbrugger, Barry A.; Haennel, Robert G.

    2001-01-01

    Evaluated the validity and reliability of a medicine ball throw test to evaluate explosive power. Data on competitive sand volleyball players who performed a medicine ball throw and a standard countermovement jump indicated that the medicine ball throw test was a valid and reliable way to assess explosive power for an analogous total-body movement…

  17. Results of metallographical diagnostic examination of Navy half-watt thermoelectric converters degraded by accelerated tests

    International Nuclear Information System (INIS)

    Rosell, F.E. Jr.; Rouklove, P.G.

    1977-01-01

    To verify the 15-year reliability of the Navy half-watt radioisotope thermoelectric generator (RTG), bismuth--telluride thermoelectric converters were submitted to testing at high temperatures which accelerated the degradation and caused failure of the converters. Metallographic diagnostic examination of failed units verified failure mechanisms. Results of diagnostic examinations are presented

  18. Ground test accelerator control system software

    International Nuclear Information System (INIS)

    Burczyk, L.; Dalesio, R.; Dingler, R.; Hill, J.; Howell, J.A.; Kerstiens, D.; King, R.; Kozubal, A.; Little, C.; Martz, V.; Rothrock, R.; Sutton, J.

    1988-01-01

    This paper reports on the GTA control system that provides an environment in which the automation of a state-of-the-art accelerator can be developed. It makes use of commercially available computers, workstations, computer networks, industrial 110 equipment, and software. This system has built-in supervisory control (like most accelerator control systems), tools to support continuous control (like the process control industry), and sequential control for automatic start-up and fault recovery (like few other accelerator control systems). Several software tools support these levels of control: a real-time operating system (VxWorks) with a real-time kernel (VRTX), a configuration database, a sequencer, and a graphics editor. VxWorks supports multitasking, fast context-switching, and preemptive scheduling. VxWorks/VRTX is a network-based development environment specifically designed to work in partnership with the UNIX operating system. A data base provides the interface to the accelerator components. It consists of a run time library and a database configuration and editing tool. A sequencer initiates and controls the operation of all sequence programs (expressed as state programs). A graphics editor gives the user the ability to create color graphic displays showing the state of the machine in either text or graphics form

  19. Accelerated life testing effects on CMOS microcircuit characteristics

    Science.gov (United States)

    1980-01-01

    The 250 C, 200C and 125C accelerated tests are described. The wear-out distributions from the 250 and 200 C tests were used to estimate the activation energy between the two test temperatures. The duration of the 125 C test was not sufficient to bring the test devices into the wear-out region. It was estimated that, for the most complex of the three devices types, the activation energy between 200 C and 125 C should be at least as high as that between 250 C and 200 C. The practicality of the use of high temperature for the accelerated life tests from the point of view of durability of equipment is assessed. Guidlines for the development of accelerated life-test conditions are proposed. The use of the silicon nitride overcoat to improve the high temperature accelerated life-test characteristics of CMOS microcircuits is described.

  20. On the application of design of experiments to accelerated life testing

    International Nuclear Information System (INIS)

    Hakim-Mashhadi, M.

    1992-01-01

    Today, there is an increasing demand for improved quality and reliability due to increasing system complexity and increasing demands from customer. Continuous improvement of quality is not only a means of competition but also a matter of staying in the market. Accelerated life testing and statistical design of experiments are two needed methods for improvement of quality. The combined use of them is very advantageous and increases the test efficiency. Accelerated life testing is a quick way to provide information on the life distribution of materials and products. By subjecting the test unit to conditions more severe than those at normal usage, the test time can be highly reduced. Estimates of life at normal stress levels are obtained by extrapolating the available information through a reasonable acceleration model. Accelerated life testing has mostly been used to measure reliability but it is high time to use it for improvement of quality. Design of experiments serves to find out the effect of design parameters and other interesting factors on performance measure and its variability. The obtained information is essential for a continuous improvement of quality. As an illustration, two sets of experiment are designed and performed at highly increased stress levels. The results are analysed and discussed and a time saving alternative is proposed. The combination of experimental design and accelerated life testing is discussed and illustrated. The combined use of these methods can be argued for in two different cases. One is for an exploratory improvement investigation and the other is for verification of reliability. In either case, the combined use is advantageous and improves the testing efficiency. Some general conclusions are drawn to be used for planning and performance of statistically designed accelerated life testing experiments. (70 refs.) (au)

  1. Using the accelerated Brazilian concrete prism test (ABCPT to evaluate alkali aggregate reaction (AAR

    Directory of Open Access Journals (Sweden)

    L. Sanchez

    Full Text Available There are many test methods used in the laboratory to detect potential alkali-aggregate reactions (AAR. However, up to now, there is no consensus if they are reliable and efficient. This work presents the development of a new and accelerated concrete prism test called ABCPT (accelerate Brazilian concrete prism test as an attempt to create a reliable and fast test that can analyze and classify the potential reactivity of aggregates in the laboratory. For this research, six aggregates from different lithotypes were used. The methods CPT, ACPT and ABCPT were carried out with all the aggregates and a comparative analysis among all tests was performed. ABCPT seems to have a great potential to analyze and classify aggregates in the laboratory, although it needs further testing with other lithotypes to be confirmed as feasible.

  2. Accelerators for Society - TIARA 2012 Test Infrastructure and Accelerator Research Area (in Polish)

    CERN Document Server

    Romaniuk, R S

    2013-01-01

    TIARA (Test Infrastructure and Accelerator Research Area - Preparatory Phae) is an European Collaboration of Accelerator Technology, which by running research projects, technical, networks and infrastructural has a duty to integrate the research and technical communities and infrastructures in the global scale of Europe. The Collaboration gathers all research centers with large accelerator infrastructures. Other ones, like universities, are affiliated as associate members. TIARA-PP (preparatory phase) is an European infrastructural project run by this Consortium and realized inside EU-FP7. The paper presents a general overview of TIARA activities, with an introduction containing a portrait of contemporary accelerator technology and a digest of its applications in modern society.

  3. Design for reliability: NASA reliability preferred practices for design and test

    Science.gov (United States)

    Lalli, Vincent R.

    1994-01-01

    This tutorial summarizes reliability experience from both NASA and industry and reflects engineering practices that support current and future civil space programs. These practices were collected from various NASA field centers and were reviewed by a committee of senior technical representatives from the participating centers (members are listed at the end). The material for this tutorial was taken from the publication issued by the NASA Reliability and Maintainability Steering Committee (NASA Reliability Preferred Practices for Design and Test. NASA TM-4322, 1991). Reliability must be an integral part of the systems engineering process. Although both disciplines must be weighed equally with other technical and programmatic demands, the application of sound reliability principles will be the key to the effectiveness and affordability of America's space program. Our space programs have shown that reliability efforts must focus on the design characteristics that affect the frequency of failure. Herein, we emphasize that these identified design characteristics must be controlled by applying conservative engineering principles.

  4. The electron test accelerator safety in design and operation

    International Nuclear Information System (INIS)

    McKeown, J.

    1980-06-01

    The Electron Test Accelerator is being designed as an experiment in accelerator physics and technology. With an electron beam power of up to 200 kW the operation of the accelerator presents a severe radiation hazard as well as rf and electrical hazards. The design of the safety system provides fail-safe protection while permitting flexibility in the mode of operation and minimizing administrative controls. (auth)

  5. Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing

    Science.gov (United States)

    Montgomery, Eliza L.; Calle, Luz Marina; Curran, Jerone C.; Kolody, Mark R.

    2011-01-01

    Evaluation of metal-based structures has long relied on atmospheric exposure test sites to determine corrosion resistance in marine environments. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions of the corrosive environment. Their success for correlation to atmospheric exposure is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated laboratory testing, which often focuses on the electrochemical reactions that occur during corrosion conditions, has yet to be universally accepted as a useful tool in predicting the long term service life of a metal despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard and their use is imperative, a method that correlates timescales from atmospheric exposure to accelerated testing would be very valuable. This work uses surface chemistry to interpret the chemical changes occurring on low carbon steel during atmospheric and accelerated corrosion conditions with the objective of finding a correlation between its accelerated and long-term corrosion performance. The current results of correlating data from marine atmospheric exposure conditions at the Kennedy Space Center beachside corrosion test site, alternating seawater spray, and immersion in typical electrochemical laboratory conditions, will be presented. Key words: atmospheric exposure, accelerated corrosion testing, alternating seawater spray, marine, correlation, seawater, carbon steel, long-term corrosion performance prediction, X-ray photoelectron spectroscopy.

  6. A test chip for automatic reliability measurements of interconnect vias

    NARCIS (Netherlands)

    Lippe, K.; Hasper, A.; Elfrink, G.W.; Niehof, J.; Kerkhoff, Hans G.

    1992-01-01

    A test circuit for electromigration reliability measurements was designed and tested. The device under test (DUT) is a via-hole chain. The test circuit permits simultaneous measurements of a number of DUTs, and a fatal error of one DUT does not influence the measurement results of the other DUTs.

  7. Reliability Testing of Cable on Environmental Humidity Condition

    International Nuclear Information System (INIS)

    Situmorang, Johnny; Puradwi, I.W; Sony T, D.T; Handoyo, Demon; Mulyanto, Dwijo; Kusmono, Slamet

    2000-01-01

    Reliability testing of cable on humidified condition has been carried out. As a result, the failure occurred due to reduction of current by increasing the resistance on rising temperature testing. For humidified condition the result which are observed did not significant at the stated condition of testing. The needed time up to the failure criteria increased as a temperature testing increased

  8. IRT-Estimated Reliability for Tests Containing Mixed Item Formats

    Science.gov (United States)

    Shu, Lianghua; Schwarz, Richard D.

    2014-01-01

    As a global measure of precision, item response theory (IRT) estimated reliability is derived for four coefficients (Cronbach's a, Feldt-Raju, stratified a, and marginal reliability). Models with different underlying assumptions concerning test-part similarity are discussed. A detailed computational example is presented for the targeted…

  9. A Latent Class Approach to Estimating Test-Score Reliability

    Science.gov (United States)

    van der Ark, L. Andries; van der Palm, Daniel W.; Sijtsma, Klaas

    2011-01-01

    This study presents a general framework for single-administration reliability methods, such as Cronbach's alpha, Guttman's lambda-2, and method MS. This general framework was used to derive a new approach to estimating test-score reliability by means of the unrestricted latent class model. This new approach is the latent class reliability…

  10. Application of a truncated normal failure distribution in reliability testing

    Science.gov (United States)

    Groves, C., Jr.

    1968-01-01

    Statistical truncated normal distribution function is applied as a time-to-failure distribution function in equipment reliability estimations. Age-dependent characteristics of the truncated function provide a basis for formulating a system of high-reliability testing that effectively merges statistical, engineering, and cost considerations.

  11. Significance of acceleration period in a dynamic strength testing study.

    Science.gov (United States)

    Chen, W L; Su, F C; Chou, Y L

    1994-06-01

    The acceleration period that occurs during isokinetic tests may provide valuable information regarding neuromuscular readiness to produce maximal contraction. The purpose of this study was to collect the normative data of acceleration time during isokinetic knee testing, to calculate the acceleration work (Wacc), and to determine the errors (ERexp, ERwork, ERpower) due to ignoring Wacc during explosiveness, total work, and average power measurements. Seven male and 13 female subjects attended the test by using the Cybex 325 system and electronic stroboscope machine for 10 testing speeds (30-300 degrees/sec). A three-way ANOVA was used to assess gender, direction, and speed factors on acceleration time, Wacc, and errors. The results indicated that acceleration time was significantly affected by speed and direction; Wacc and ERexp by speed, direction, and gender; and ERwork and ERpower by speed and gender. The errors appeared to increase when testing the female subjects, during the knee flexion test, or when speed increased. To increase validity in clinical testing, it is important to consider the acceleration phase effect, especially in higher velocity isokinetic testing or for weaker muscle groups.

  12. Reliability and availability considerations in the RF systems of ATW-class accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Tallerico, P.J.; Lynch, M.T.; Lawrence, G. [Los Alamos National Laboratory, NM (United States)

    1995-10-01

    In an RF-driven, ion accelerator for waste transmutation or nuclear material production, the overall availability is perhaps the most important specification. The synchronism requirements in an ion accelerator, as contrasted to an electron accelerator, cause a failure of an RF source to have a greater consequence. These large machines also are major capital investments, so the availability determines the return on this capital. RF system design methods to insure a high availability without paying a serious cost penalty are the subject of this paper. The overall availability goal in the present designs is 75% for the entire ATW complex, and from 25 to 35% of the unavailability is allocated to the RF system, since it is one of the most complicated subsystems in the complex. The allowed down time for the RF system (including the linac and all other systems) is then only 7 to 9% of the operating time per year, or as little as 613 hours per year, for continuous operation. Since large accelerators consume large amounts of electrical power, excellent efficiency is also required with the excellent availability. The availability also influences the sizes of the RF components; smaller components may fail and yet the accelerator may still meet all specifications. Larger components are also attractive, since the cost of an RF system usually increases as the square root of the number of RF systems utilized. In some cases, there is a reliability penalty that accompanies the cost savings from using larger components. The authors discuss these factors, and present an availability model that allows one to examine these trade offs, and make rational choices in the RF and accelerator system designs.

  13. Accelerated spike resampling for accurate multiple testing controls.

    Science.gov (United States)

    Harrison, Matthew T

    2013-02-01

    Controlling for multiple hypothesis tests using standard spike resampling techniques often requires prohibitive amounts of computation. Importance sampling techniques can be used to accelerate the computation. The general theory is presented, along with specific examples for testing differences across conditions using permutation tests and for testing pairwise synchrony and precise lagged-correlation between many simultaneously recorded spike trains using interval jitter.

  14. Automation of testing the metrological reliability of nondestructive control systems

    International Nuclear Information System (INIS)

    Zhukov, Yu.A.; Isakov, V.B.; Karlov, Yu.K.; Kovalevskij, Yu.A.

    1987-01-01

    Opportunities of microcomputers are used to solve the problem of testing control-measuring systems. Besides the main program the program of data processing when characterizing the nondestructive control systems is written in the microcomputer. The program includes two modules. The first module contains tests-programs, by which accuracy of functional elements of the microcomputer and interface elements with issuing a message to the operator on readiness of the elements for operation and failure of a certain element are determined. The second module includes: calculational programs when determining metrological reliability of measuring channel reliability, a calculational subprogram for random statistical measuring error, time instability and ''dead time''. Automation of testing metrological reliability of the nondestructive control systems increases reliability of determining metrological parameters and reduces time of system testing

  15. Validity, Reliability, and Sensitivity of a Volleyball Intermittent Endurance Test.

    Science.gov (United States)

    Rodríguez-Marroyo, Jose A; Medina-Carrillo, Javier; García-López, Juan; Morante, Juan C; Villa, José G; Foster, Carl

    2017-03-01

    To analyze the concurrent and construct validity of a volleyball intermittent endurance test (VIET). The VIET's test-retest reliability and sensitivity to assess seasonal changes was also studied. During the preseason, 71 volleyball players of different competitive levels took part in this study. All performed the VIET and a graded treadmill test with gas-exchange measurement (GXT). Thirty-one of the players performed an additional VIET to analyze the test-retest reliability. To test the VIET's sensitivity, 28 players repeated the VIET and GXT at the end of their season. Significant (P volleyball players.

  16. Re-test reliability of gustatory testing and introduction of the sensitive Taste-Drop-Test

    DEFF Research Database (Denmark)

    Fjaeldstad, A; Niklassen, A; Fernandes, H

    2018-01-01

    . Testing gustatory function can be important for diagnostics and assessment of treatment effects. However, the gustatory tests applied are required to be both sensitive and reliable.In this study, we investigate the re-test validity of popular Taste Strips gustatory test for gustatory screening....... Furthermore, we introduce a new sensitive Taste-Drop-Test, which was found to be superior for detecting a more accurate measure of tastant sensitivity....

  17. Accelerated storage testing of freeze-dried Pseudomonas ...

    African Journals Online (AJOL)

    Accelerated storage testing of freeze-dried Pseudomonas fluorescens BTP1, ... of all P. fluorescens strains were not significantly different and thermal inactivation ... useful to the development of improved reference materials and samples held ...

  18. Scientists confirm delay in testing new CERN particle accelerator

    CERN Multimedia

    2007-01-01

    "Scientists seeking to uncover the secrets of the universe will have to wait a little longer after the CERN laboratory inswitzerland on Monday confirmed a delay in tests of a massive new particle accelerator." (1 page)

  19. NASA reliability preferred practices for design and test

    Science.gov (United States)

    1991-01-01

    Given here is a manual that was produced to communicate within the aerospace community design practices that have contributed to NASA mission success. The information represents the best technical advice that NASA has to offer on reliability design and test practices. Topics covered include reliability practices, including design criteria, test procedures, and analytical techniques that have been applied to previous space flight programs; and reliability guidelines, including techniques currently applied to space flight projects, where sufficient information exists to certify that the technique will contribute to mission success.

  20. Reliability performance of standby equipment with periodic testing

    International Nuclear Information System (INIS)

    Sim, S.H.

    1985-11-01

    In this report, the reliability performance of standby equipment subjected to periodic testing is studied. analytical expressions have been derived for reliability measures, such as the man accumulated operating time to failure, the expected number of tests between two consecutive failures, the mean time to failure following an emergency start-up and the probability of failing to complete an emergency mission of a specified duration. These results are useful for the reliability assessment of standby equipment such as combustion turbine units of the emergency power supply system, and of the Class III power system at a nuclear generating station

  1. Reliability demonstration test planning: A three dimensional consideration

    International Nuclear Information System (INIS)

    Yadav, Om Prakash; Singh, Nanua; Goel, Parveen S.

    2006-01-01

    Increasing customer demand for reliability, fierce market competition on time-to-market and cost, and highly reliable products are making reliability testing more challenging task. This paper presents a systematic approach for identifying critical elements (subsystems and components) of the system and deciding the types of test to be performed to demonstrate reliability. It decomposes the system into three dimensions (i.e. physical, functional and time) and identifies critical elements in the design by allocating system level reliability to each candidate. The decomposition of system level reliability is achieved by using criticality index. The numerical value of criticality index for each candidate is derived based on the information available from failure mode and effects analysis (FMEA) document or warranty data from a prior system. It makes use of this information to develop reliability demonstration test plan for the identified (critical) failure mechanisms and physical elements. It also highlights the benefits of using prior information in order to locate critical spots in the design and in subsequent development of test plans. A case example is presented to demonstrate the proposed approach

  2. Cosmological consistency tests of gravity theory and cosmic acceleration

    Science.gov (United States)

    Ishak-Boushaki, Mustapha B.

    2017-01-01

    Testing general relativity at cosmological scales and probing the cause of cosmic acceleration are among the important objectives targeted by incoming and future astronomical surveys and experiments. I present our recent results on consistency tests that can provide insights about the underlying gravity theory and cosmic acceleration using cosmological data sets. We use statistical measures, the rate of cosmic expansion, the growth rate of large scale structure, and the physical consistency of these probes with one another.

  3. The first acceleration test of polarized protons in KEK PS

    International Nuclear Information System (INIS)

    Hiramatsu, Shigenori; Sato, Hikaru; Toyama, Takeshi

    1984-03-01

    The outline of the polarized proton acceleration project at KEK and the results of the first acceleration test are described. Depolarization in the 500 MeV booster synchrotron was investigated as the first step of this program. The beam polarization was measured in the 20 MeV beam transport line from the linac to the booster and in the main ring at the injection energy. About 40 % of the linac beam polarization was kept in the main ring. This acceleration test encouraged us to proceed with this program. (author)

  4. Operational reliability testing of FBR fuel in EBR-II

    International Nuclear Information System (INIS)

    Asaga, Takeo; Ukai, Shigeharu; Nomura, Shigeo; Shikakura, Sakae

    1991-01-01

    The operational reliability testing of FBR fuel has been conducting in EBR-II as a DOE/PNC collaboration program. This paper reviews the achieved summary of Phase-I test as well as outline of progressing Phase-II test. In Phase-I test, the reliability of FBR fuel pins including 'MONJU' fuel was demonstrated at the event of operational transient. Continued operation of the failed pins was also shown to be feasible without affecting the plant operation. The objectives of the Phase-II test is to extend the data base relating with the operational reliability for long life fuel, and to supply the highly quantitative evaluation. The valuable insight obtained in Phase-II test are considerably expected to be useful toward the achievement of commercial FBR. (author)

  5. Reliability of four experimental mechanical pain tests in children

    Directory of Open Access Journals (Sweden)

    Soee AL

    2013-02-01

    Full Text Available Ann-Britt L Soee,1 Lise L Thomsen,2 Birte Tornoe,1,3 Liselotte Skov11Department of Pediatrics, Children’s Headache Clinic, Copenhagen University Hospital Herlev, Copenhagen, Denmark; 2Department of Neuropediatrics, Juliane Marie Centre, Copenhagen University Hospital Rigshospitalet, København Ø, Denmark; 3Department of Physiotherapy, Medical Department O, Copenhagen University Hospital Herlev, Herlev, DenmarkPurpose: In order to study pain in children, it is necessary to determine whether pain measurement tools used in adults are reliable measurements in children. The aim of this study was to explore the intrasession reliability of pressure pain thresholds (PPT in healthy children. Furthermore, the aim was also to study the intersession reliability of the following four tests: (1 Total Tenderness Score; (2 PPT; (3 Visual Analog Scale score at suprapressure pain threshold; and (4 area under the curve (stimulus–response functions for pressure versus pain.Participants and methods: Twenty-five healthy school children, 8–14 years of age, participated. Test 2, PPT, was repeated three times at 2 minute intervals on the same day to estimate PPT intrasession reliability using Cronbach’s alpha. Tests 1–4 were repeated after median 21 (interquartile range 10.5–22 days, and Pearson’s correlation coefficient was used to describe the intersession reliability.Results: The PPT test was precise and reliable (Cronbach’s alpha ≥ 0.92. All tests showed a good to excellent correlation between days (intersessions r = 0.66–0.81. There were no indications of significant systematic differences found in any of the four tests between days.Conclusion: All tests seemed to be reliable measurements in pain evaluation in healthy children aged 8–14 years. Given the small sample size, this conclusion needs to be confirmed in future studies.Keywords: repeatability, intraindividual reliability, pressure pain threshold, pain measurement, algometer

  6. Accelerated battery-life testing - A concept

    Science.gov (United States)

    Mccallum, J.; Thomas, R. E.

    1971-01-01

    Test program, employing empirical, statistical and physical methods, determines service life and failure probabilities of electrochemical cells and batteries, and is applicable to testing mechanical, electrical, and chemical devices. Data obtained aids long-term performance prediction of battery or cell.

  7. Earthquake acceleration amplification based on single microtremor test

    Science.gov (United States)

    Jaya Syahbana, Arifan; Kurniawan, Rahmat; Soebowo, Eko

    2018-02-01

    Understanding soil dynamics is needed to understand soil behaviour, including the parameters of earthquake acceleration amplification. Many researchers now conduct single microtremor tests to obtain amplification of velocity and natural periods of soil at test sites. However, these amplification parameters are rarely used, so a method is needed to convert the velocity amplification to acceleration amplification. This paper will discuss the proposed process of changing the value of amplification. The proposed method is to integrate the time histories of the synthetic earthquake acceleration of the soil surface under the deaggregation at that location so the time histories of the velocity earthquake will be obtained. Next is to conduct a “fitting curve” between amplification by a single microtremor test with amplification of the synthetic earthquake velocity time histories. After obtaining the fitting curve time histories of velocity, differentiation will be conducted to obtain fitting curve acceleration time histories. The final step after obtaining the fitting curve is to compare the acceleration of the “fitting curve” against the histories time of the acceleration of synthetic earthquake at bedrocks to obtain single microtremor acceleration amplification factor.

  8. Reliability of movement control tests in the lumbar spine

    Directory of Open Access Journals (Sweden)

    de Bruin Eling D

    2007-09-01

    Full Text Available Abstract Background Movement control dysfunction [MCD] reduces active control of movements. Patients with MCD might form an important subgroup among patients with non specific low back pain. The diagnosis is based on the observation of active movements. Although widely used clinically, only a few studies have been performed to determine the test reliability. The aim of this study was to determine the inter- and intra-observer reliability of movement control dysfunction tests of the lumbar spine. Methods We videoed patients performing a standardized test battery consisting of 10 active movement tests for motor control in 27 patients with non specific low back pain and 13 patients with other diagnoses but without back pain. Four physiotherapists independently rated test performances as correct or incorrect per observation, blinded to all other patient information and to each other. The study was conducted in a private physiotherapy outpatient practice in Reinach, Switzerland. Kappa coefficients, percentage agreements and confidence intervals for inter- and intra-rater results were calculated. Results The kappa values for inter-tester reliability ranged between 0.24 – 0.71. Six tests out of ten showed a substantial reliability [k > 0.6]. Intra-tester reliability was between 0.51 – 0.96, all tests but one showed substantial reliability [k > 0.6]. Conclusion Physiotherapists were able to reliably rate most of the tests in this series of motor control tasks as being performed correctly or not, by viewing films of patients with and without back pain performing the task.

  9. Optimal number of tests to achieve and validate product reliability

    International Nuclear Information System (INIS)

    Ahmed, Hussam; Chateauneuf, Alaa

    2014-01-01

    The reliability validation of engineering products and systems is mandatory for choosing the best cost-effective design among a series of alternatives. Decisions at early design stages have a large effect on the overall life cycle performance and cost of products. In this paper, an optimization-based formulation is proposed by coupling the costs of product design and validation testing, in order to ensure the product reliability with the minimum number of tests. This formulation addresses the question about the number of tests to be specified through reliability demonstration necessary to validate the product under appropriate confidence level. The proposed formulation takes into account the product cost, the failure cost and the testing cost. The optimization problem can be considered as a decision making system according to the hierarchy of structural reliability measures. The numerical examples show the interest of coupling design and testing parameters. - Highlights: • Coupled formulation for design and testing costs, with lifetime degradation. • Cost-effective testing optimization to achieve reliability target. • Solution procedure for nested aleatoric and epistemic variable spaces

  10. Models on reliability of non-destructive testing

    International Nuclear Information System (INIS)

    Simola, K.; Pulkkinen, U.

    1998-01-01

    The reliability of ultrasonic inspections has been studied in e.g. international PISC (Programme for the Inspection of Steel Components) exercises. These exercises have produced a large amount of information on the effect of various factors on the reliability of inspections. The information obtained from reliability experiments are used to model the dependency of flaw detection probability on various factors and to evaluate the performance of inspection equipment, including the sizing accuracy. The information from experiments is utilised in a most effective way when mathematical models are applied. Here, some statistical models for reliability of non-destructive tests are introduced. In order to demonstrate the use of inspection reliability models, they have been applied to the inspection results of intergranular stress corrosion cracking (IGSCC) type flaws in PISC III exercise (PISC 1995). The models are applied to both flaw detection frequency data of all inspection teams and to flaw sizing data of one participating team. (author)

  11. Reliability of four experimental mechanical pain tests in children

    DEFF Research Database (Denmark)

    Søe, Ann-Britt Langager; Thomsen, Lise L; Tornoe, Birte

    2013-01-01

    In order to study pain in children, it is necessary to determine whether pain measurement tools used in adults are reliable measurements in children. The aim of this study was to explore the intrasession reliability of pressure pain thresholds (PPT) in healthy children. Furthermore, the aim was a...... was also to study the intersession reliability of the following four tests: (1) Total Tenderness Score; (2) PPT; (3) Visual Analog Scale score at suprapressure pain threshold; and (4) area under the curve (stimulus-response functions for pressure versus pain).......In order to study pain in children, it is necessary to determine whether pain measurement tools used in adults are reliable measurements in children. The aim of this study was to explore the intrasession reliability of pressure pain thresholds (PPT) in healthy children. Furthermore, the aim...

  12. Proving Test on the Reliability for Reactor Containment Vessel

    International Nuclear Information System (INIS)

    Takumi, K.; Nonaka, A.

    1988-01-01

    NUPEC (Nuclear Power Engineering Test Center) has started an eight-year project of Proving Test on the Reliability for Reactor Containment Vessel since June 1987. The objective of this project is to confirm the integrity of containment vessels under severe accident conditions. This paper shows the outline of this project. The test Items are (1) Hydrogen mixing and distribution test, (2) Hydrogen burning test, (3) Iodine trapping characteristics test, and (4) Structural behavior test. Based on the test results, computer codes are verified and as the results of analysis and evaluation by the computer codes, containment integrity is to be confirmed

  13. Tests of compressed geometry NEC acceleration tubes

    International Nuclear Information System (INIS)

    Raatz, J.E.; Rathmell, R.D.; Stelson, P.H.; Ziegler, N.F.

    1985-01-01

    Tests have been performed in the 3 MV Pelletron test machine at NEC on a compressed geometry tube which increases the insulating length of the tube by eliminating the heated electrode assemblies (approx.2.5 cm thick) at the end of each tube section. Some insert electrodes are changed to provide some trapping of secondary ions. The geometry tested provided an 18% increase in live ceramic in the tube. The compressed geometry tube allowed a terminal voltage of 3.55 MV on the 3 MV column at normal gradients of 30.3 kv/tube gap. The tube was also conditioned to more than 4 MV and remained stable in voltage with few sparks and with low x-ray levels for days at about 4 MV. This same performance could be achieved with or without arc discharge cleaning. 4 refs., 4 figs

  14. Methodology to improve design of accelerated life tests in civil engineering projects.

    Directory of Open Access Journals (Sweden)

    Jing Lin

    Full Text Available For reliability testing an Energy Expansion Tree (EET and a companion Energy Function Model (EFM are proposed and described in this paper. Different from conventional approaches, the EET provides a more comprehensive and objective way to systematically identify external energy factors affecting reliability. The EFM introduces energy loss into a traditional Function Model to identify internal energy sources affecting reliability. The combination creates a sound way to enumerate the energies to which a system may be exposed during its lifetime. We input these energies into planning an accelerated life test, a Multi Environment Over Stress Test. The test objective is to discover weak links and interactions among the system and the energies to which it is exposed, and design them out. As an example, the methods are applied to the pipe in subsea pipeline. However, they can be widely used in other civil engineering industries as well. The proposed method is compared with current methods.

  15. Methodology to improve design of accelerated life tests in civil engineering projects.

    Science.gov (United States)

    Lin, Jing; Yuan, Yongbo; Zhou, Jilai; Gao, Jie

    2014-01-01

    For reliability testing an Energy Expansion Tree (EET) and a companion Energy Function Model (EFM) are proposed and described in this paper. Different from conventional approaches, the EET provides a more comprehensive and objective way to systematically identify external energy factors affecting reliability. The EFM introduces energy loss into a traditional Function Model to identify internal energy sources affecting reliability. The combination creates a sound way to enumerate the energies to which a system may be exposed during its lifetime. We input these energies into planning an accelerated life test, a Multi Environment Over Stress Test. The test objective is to discover weak links and interactions among the system and the energies to which it is exposed, and design them out. As an example, the methods are applied to the pipe in subsea pipeline. However, they can be widely used in other civil engineering industries as well. The proposed method is compared with current methods.

  16. Acceleration of the LHC commissioning tests

    CERN Multimedia

    2008-01-01

    The quadrupole and main dipole circuits have been powered up to 10,200 amps in Sector 4-5. Sector 5-6 is currently being cooled and will be the next to undergo electrical tests, which will be stepped up over the next few weeks.

  17. Electrical performance characteristics of the SSC Accelerator System String Test

    International Nuclear Information System (INIS)

    Robinson, W.; Burgett, W.; Gannon, J.; Kraushaar, P.; Mcinturff, A.; Nehring, R.; Saladin, V.; Savord, T.; Sorrensen, G.; Smellie, R.; Tool, G.; Voy, D.

    1993-05-01

    The intent of the Accelerator System String Test (ASST) is to obtain data for model verification and information on the magnitudes of pressures and voltages encountered in an accelerator environment. The ASST milestone run was achieved during July and August, 1992 and consisted of demonstrating the accelerator components could be configured together as a system operating at full current. Following the milestone run, the string was warmed to counteract some design flaws that impeded the operational range. The string was again cooled to cryogenic temperatures in October, and a comprehensive power testing program was conducted through the end of January, 1993. This paper describes how the collider arc components operate in an accelerator environment during quenches induced by firing both strip heaters and spot heaters. Evaluation of the data illustrates how variations in the design parameters on magnets used in a string environment can impact system performance

  18. NLC. A test accelerator for the next linear collider

    International Nuclear Information System (INIS)

    Ruth, R.D.; Adolphsen, C.; Bane, K.; Boyce, R.F.; Burke, D.L.; Callin, R.; Caryotakis, G.; Cassel, R.; Clark, S.L.; Deruyter, H.; Fant, K.; Fuller, R.; Heifets, S.; Hoag, H.; Humphrey, R.; Kheifets, S.; Koontz, R.; Kroll, N.M.; Lavine, T.; Loew, G.A.; Menegat, A.; Miller, R.H.; Nantista, C.; Paterson, J.M.; Pearson, C.; Phillips, R.; Rifkin, J.; Spencer, J.; Tantawi, S.; Thompson, K.A.; Vlieks, A.; Vylet, V.; Wang, J.W.; Wilson, P.B.; Yeremian, A.; Youngman, B.

    1993-01-01

    At SLAC, we are pursuing the design of a Next Linear Collider (NLC) which would begin with a center-of-mass energy of 0.5 TeV, and be upgradable to at least 1.0 TeV. To achieve this high energy, we have been working on the development of a high-gradient 11.4-GHz (X-band) linear accelerator for the main linac of the collider. In this paper, we present the design of a 'Next Linear Collider Test Accelerator' (NLCTA). The goal of the NLCTA is to incorporate the new technologies of X-band accelerator structures, RF pulse compression systems and klystrons into a short linac which will then be a test bed for beam dynamics issues related to high-gradient acceleration. (orig.)

  19. Reliability of a New Lower-Extremity Motor Coordination Test

    Directory of Open Access Journals (Sweden)

    Antosiak-Cyrak Katarzyna

    2015-12-01

    Full Text Available Introduction. Motor coordination is a basic motor ability necessary for daily life, which also allows athletes to win a sports rivalry and patients to assess their recovery progress after therapy and rehabilitation. The aim of the present study was to assess the reliability of a new lower-extremity rate of movements test and testing apparatus.

  20. Test setup for long term reliability investigation of Silicon Carbide MOSFETs

    DEFF Research Database (Denmark)

    Baker, Nick; Munk-Nielsen, Stig; Beczkowski, Szymon

    2013-01-01

    Silicon Carbide MOSFETs are now widely available and have frequently been demonstrated to offer numerous advantages over Silicon based devices. However, reliability issues remain a significant concern in their realisation in commercial power electronic systems. In this paper, a test bench...... is designed that enables an accelerated power cycling test to be performed on packaged Silicon Carbide MOSFETs (TO-247) under realistic operating conditions. An accelerated power cycling test is then performed, with on-state resistance selected as the observed parameter to detect degradation. On......-state resistance is routinely monitored online through the use of an innovative voltage measurement system. The packaged Silicon Carbide MOSFET is shown to exhibit a 25% increase in on-state resistance as the device ages throughout its lifetime, with the test still on-going....

  1. An induction accelerator for the Heidelberg Test Storage Ring TSR

    International Nuclear Information System (INIS)

    Ellert, C.; Habs, D.; Music, M.; Schwalm, D.; Wolf, A.; Jaeschke, E.; Kambara, T.; Sigray, P.

    1992-01-01

    An induction accelerator has been installed in the heavy ion test storage ring TSR in Heidelberg. It allows for constant acceleration or deceleration of stored coasting ion beams without affecting their velocity profile and is well suited for ion beam manipulation in cooling experiments and for measurements of velocity dependent cooling forces. The design and operation of the device and first applications to laser cooling and to measurements of laser and electron cooling forces are described. (orig.)

  2. Time-dependent diffusive acceleration of test particles at shocks

    Energy Technology Data Exchange (ETDEWEB)

    Drury, L.O' C. (Dublin Inst. for Advanced Studies (Ireland))

    1991-07-15

    The acceleration of test particles at a steady plane non-relativistic shock is considered. Analytic expressions are found for the mean and the variance of the acceleration time distribution in the case where the diffusion coefficient has an arbitrary dependence on position and momentum. These expressions are used as the basis for an approximation scheme which is shown, by comparison with numerical solutions, to give an excellent representation of the time-dependent spectrum. (author).

  3. Time-dependent diffusive acceleration of test particles at shocks

    International Nuclear Information System (INIS)

    Drury, L.O'C.

    1991-01-01

    The acceleration of test particles at a steady plane non-relativistic shock is considered. Analytic expressions are found for the mean and the variance of the acceleration time distribution in the case where the diffusion coefficient has an arbitrary dependence on position and momentum. These expressions are used as the basis for an approximation scheme which is shown, by comparison with numerical solutions, to give an excellent representation of the time-dependent spectrum. (author)

  4. Factors affecting accelerated testing of polymer photostability

    Czech Academy of Sciences Publication Activity Database

    Pospíšil, Jan; Pilař, Jan; Billingham, N. C.; Marek, Antonín; Horák, Zdeněk; Nešpůrek, Stanislav

    2006-01-01

    Roč. 91, č. 3 (2006), s. 417-422 ISSN 0141-3910. [International Conference on Modification, Degradation, Stabilization Conference /3./. Lyon, 29.08.2004-02.09.2004] R&D Projects: GA ČR GA203/02/1243; GA ČR GA202/01/0518; GA MŠk ME 543 Institutional research plan: CEZ:AV0Z40500505 Keywords : photodegradation * photostabilization * testing Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.174, year: 2006

  5. A comparative study of accelerated tests to simulate atmospheric corrosion

    International Nuclear Information System (INIS)

    Assis, Sergio Luiz de

    2000-01-01

    In this study, specimens coated with five organic coating systems were exposed to accelerated tests for periods up to 2000 hours, and also to weathering for two years and six months. The accelerated tests consisted of the salt spray test, according to ASTM B-117; Prohesion (ASTM G 85-98 annex 5A); Prohesion combined with cyclic exposure to UV-A radiation and condensation; 'Prohchuva' a test described by ASTM G 85-98 using a salt spray with composition that simulated the acid rain of Sao Paulo, but one thousand times more concentrated, and 'Prohchuva' combined with cyclic exposure to UV-A radiation and condensation. The coated specimens were exposed with and without incision to expose the substrate. The onset and progress of corrosion at and of the exposed metallic surface, besides coating degradation, were followed by visual observation, and photographs were taken. The coating systems were classified according to the extent of corrosion protection given to the substrate, using a method based on ASTM standards D-610, D-714, D-1654 and D-3359. The rankings of the coatings obtained from accelerated tests and weathering were compared and contrasted with classification of the same systems obtained from literature, for specimens exposed to an industrial atmosphere. Coating degradation was strongly dependent on the test, and could be attributed to differences in test conditions. The best correlation between accelerated test and weathering was found for the test Prohesion alternated with cycles of exposure to UV-A radiation and condensation. (author)

  6. Nuclear-waste-package materials degradation modes and accelerated testing

    International Nuclear Information System (INIS)

    1981-09-01

    This report reviews the materials degradation modes that may affect the long-term behavior of waste packages for the containment of nuclear waste. It recommends an approach to accelerated testing that can lead to the qualification of waste package materials in specific repository environments in times that are short relative to the time period over which the waste package is expected to provide containment. This report is not a testing plan but rather discusses the direction for research that might be considered in developing plans for accelerated testing of waste package materials and waste forms

  7. RF pulse compression in the NLC test accelerator at SLAC

    International Nuclear Information System (INIS)

    Lavine, T.L.

    1995-01-01

    At the Stanford Linear Accelerator Center (SLAC), the authors are designing a Next Linear Collider (NLC) with linacs powered by X-band klystrons with rf pulse compression. The design of the linac rf system is based on X-band prototypes which have been tested at high power, and on a systems-integration test - the Next Linear Collider Test Accelerator (NLCTA) - which is currently under construction at SLAC. This paper discusses some of the systems implications of rf pulse compression, and the use of pulse compression in the NLCTA, both for peak power multiplication and for controlling, by rf phase modulation, intra-pulse variations in the linac beam energy

  8. Reliability performance testing of totally encapsulating chemical protective suits

    International Nuclear Information System (INIS)

    Johnson, J.S.; Swearengen, P.M.

    1991-01-01

    The need to assure a high degree of reliability for totally encapsulating chemical protective (TECP) suits has been recognized by Lawrence Livermore National Laboratory's (LLNL) Hazards Control Department for some time. The following four tests were proposed as necessary to provide complete evaluation of TECP suit performance: 1. Quantitative leak test (ASTM draft), 2. Worst-case chemical exposure test (conceptual), 3. Pressure leak-rate test (complete, ASTM F1057-87), and 4. Chemical leak-rate test (ASTM draft). This paper reports on these tests which should be applied to measuring TECP suit performance in two stages: design qualification tests and field use tests. Test 1, 2, and 3 are used as design qualification tests, and tests 3 and 4 are used as field use tests

  9. Accelerated corrosion test for metal drainage pipes : final report.

    Science.gov (United States)

    1987-06-01

    This study represents an attempt to develop an accelerated test which would assist the highway engineer in evaluating the usefulness of a new type of coated steel culvert. The test method was to be short in duration (in the order of days), and the re...

  10. Large test rigs verify Clinch River control rod reliability

    International Nuclear Information System (INIS)

    Michael, H.D.; Smith, G.G.

    1983-01-01

    The purpose of the Clinch River control test programme was to use multiple full-scale prototypic control rod systems for verifying the system's ability to perform reliably during simulated reactor power control and emergency shutdown operations. Two major facilities, the Shutdown Control Rod and Maintenance (Scram) facility and the Dynamic and Seismic Test (Dast) facility, were constructed. The test programme of each facility is described. (UK)

  11. Reliability and microstructure of lead-free solder joints in industrial electronics after accelerated thermal aging

    NARCIS (Netherlands)

    Scaltro, F.; Biglari, M.H.; Kodentsov, A.; Yakovleva, O.; Brom, E.

    2009-01-01

    The reliability of lead-free (LF) solder joints in surface-mounted device components (SMD) has been investigated after thermo-cycle testing. Kirkendall voids have been observed at the interface component/solder together with the formation of fractures. The evolution, the morphology and the elemental

  12. Demonstration test for reliability of valves for atomic power plants

    International Nuclear Information System (INIS)

    Hosaka, Shiro

    1978-01-01

    The demonstration test on the reliability of valves for atomic power plants being carried out by the Nuclear Engineering Test Center is reported. This test series is conducted as six-year project from FY 1976 to FY 1981 at the Isogo Test Center. The demonstration test consists of (1) environmental test, (2) reaction force test, (3) vibration test, (4) stress measurement test, (5) operational characteristic test, (6) flow resistance coefficient measuring test, (7) leakage test and (8) safety valve and relief valve test. These contents are explained about the special requirements for nuclear use, for example, the enviornmental condition after the design base accident of PWRs and BWRs, the environmental test sequence for isolation valves of containment vessels under the emergency condition, the seismic test condition for valves of nuclear use, the various stress measurements under thermal transient conditions, the leak test after 500 cycles between the normal operating conditions for PWRs and BWRs and the start up conditions and so on. As for the testing facilities, the whole flow diagram is shown, in which the environmental test section, the vibration test section, the steam test section, the hot water test section, the safety valve test section and main components are included. The specifications of each test section and main components are presented. (Nakai, Y.)

  13. FFTF [Fast Flux Test Facility] reactor shutdown system reliability reevaluation

    International Nuclear Information System (INIS)

    Pierce, B.F.

    1986-07-01

    The reliability analysis of the Fast Flux Test Facility reactor shutdown system was reevaluated. Failure information based on five years of plant operating experience was used to verify original reliability numbers or to establish new ones. Also, system modifications made subsequent to performance of the original analysis were incorporated into the reevaluation. Reliability calculations and sensitivity analyses were performed using a commercially available spreadsheet on a personal computer. The spreadsheet was configured so that future failures could be tracked and compared with expected failures. A number of recommendations resulted from the reevaluation including both increased and decreased surveillance intervals. All recommendations were based on meeting or exceeding existing reliability goals. Considerable cost savings will be incurred upon implementation of the recommendations

  14. Reliability of wind turbine blades: An overview of materials testing

    DEFF Research Database (Denmark)

    Holmes, John W.; Sørensen, Bent F.; Brøndsted, Povl

    2007-01-01

    an understanding of how damage develops in composite structures, composite materials and adhesives. Designing reliable wind turbine blades also requires the further development of laboratory scale and full scale test methods to evaluate the structural response and durability of new materials under various loading......The structural reliability of wind turbine components can have a profound impact on both the profitability and reputation of a wind turbine manufacturer or supplier of wind turbine components. The issue of reliability is of critical concern when large wind farm co-operatives are considered......, and when wind turbines are located in remote regions where the cost of inspections and repairs can be very high. From a structural viewpoint, wind turbine blades are subjected to very complex loading histories with coupled deformation modes. The long-term reliability of wind turbine blades requires...

  15. Validity and Reliability of Baseline Testing in a Standardized Environment.

    Science.gov (United States)

    Higgins, Kathryn L; Caze, Todd; Maerlender, Arthur

    2017-08-11

    The Immediate Postconcussion Assessment and Cognitive Testing (ImPACT) is a computerized neuropsychological test battery commonly used to determine cognitive recovery from concussion based on comparing post-injury scores to baseline scores. This model is based on the premise that ImPACT baseline test scores are a valid and reliable measure of optimal cognitive function at baseline. Growing evidence suggests that this premise may not be accurate and a large contributor to invalid and unreliable baseline test scores may be the protocol and environment in which baseline tests are administered. This study examined the effects of a standardized environment and administration protocol on the reliability and performance validity of athletes' baseline test scores on ImPACT by comparing scores obtained in two different group-testing settings. Three hundred-sixty one Division 1 cohort-matched collegiate athletes' baseline data were assessed using a variety of indicators of potential performance invalidity; internal reliability was also examined. Thirty-one to thirty-nine percent of the baseline cases had at least one indicator of low performance validity, but there were no significant differences in validity indicators based on environment in which the testing was conducted. Internal consistency reliability scores were in the acceptable to good range, with no significant differences between administration conditions. These results suggest that athletes may be reliably performing at levels lower than their best effort would produce. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Optimization of the reliability of ADS accelerators in the framework of the EUROTRANS project; Optimisation de la fiabilite des accelerateurs ADS dans le cadre du projet EUROTRANS

    Energy Technology Data Exchange (ETDEWEB)

    Lucija, Lukovac

    2007-07-01

    In order to limit the number of thermal shocks in the spallation targets and in the core of an ADS (Accelerator Driven System), it is necessary to limit the number of failures of the beam accelerating system. This article presents the improvements in terms of reliability for 2 sub-systems of the ADS: the control system that is in charge of the RF power equipment that delivers the energy necessary to the accelerating system and the power coupler whose purpose is to transfer energy from RF generator to the accelerating cavities. The digitalization of the control system has allowed the application of a compensation method: if one of the cavities fails, the neighbouring cavities are regulated to limit the consequences of the failure on the beam. As for the power coupler, the ceramic window has been designed with great care. The improvements will be tested on 2 prototypes that are being built. (A.C.)

  17. Development of seismic technology and reliability based on vibration tests

    International Nuclear Information System (INIS)

    Sasaki, Youichi

    1997-01-01

    This paper deals with some of the vibration tests and investigations on the seismic safety of nuclear power plants (NPPs) in Japan. To ensure the reliability of the seismic safety of nuclear power plants, nuclear power plants in Japan have been designed according to the Technical Guidelines for Aseismic Design of Nuclear Power Plants. This guideline has been developed based on technical date base and findings which were obtained from many vibration tests and investigations. Besides the tests for the guideline, proving tests on seismic reliability of operating nuclear power plants equipment and systems have been carried out. In this paper some vibration tests and their evaluation results are presented. They have crucially contributed to develop the guideline. (J.P.N.)

  18. Development of seismic technology and reliability based on vibration tests

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Youichi [Nuclear Power Engineering Corp., Tokyo (Japan)

    1997-03-01

    This paper deals with some of the vibration tests and investigations on the seismic safety of nuclear power plants (NPPs) in Japan. To ensure the reliability of the seismic safety of nuclear power plants, nuclear power plants in Japan have been designed according to the Technical Guidelines for Aseismic Design of Nuclear Power Plants. This guideline has been developed based on technical date base and findings which were obtained from many vibration tests and investigations. Besides the tests for the guideline, proving tests on seismic reliability of operating nuclear power plants equipment and systems have been carried out. In this paper some vibration tests and their evaluation results are presented. They have crucially contributed to develop the guideline. (J.P.N.)

  19. Validity and reliability of the NAB Naming Test.

    Science.gov (United States)

    Sachs, Bonnie C; Rush, Beth K; Pedraza, Otto

    2016-05-01

    Confrontation naming is commonly assessed in neuropsychological practice, but few standardized measures of naming exist and those that do are susceptible to the effects of education and culture. The Neuropsychological Assessment Battery (NAB) Naming Test is a 31-item measure used to assess confrontation naming. Despite adequate psychometric information provided by the test publisher, there has been limited independent validation of the test. In this study, we investigated the convergent and discriminant validity, internal consistency, and alternate forms reliability of the NAB Naming Test in a sample of adults (Form 1: n = 247, Form 2: n = 151) clinically referred for neuropsychological evaluation. Results indicate adequate-to-good internal consistency and alternate forms reliability. We also found strong convergent validity as demonstrated by relationships with other neurocognitive measures. We found preliminary evidence that the NAB Naming Test demonstrates a more pronounced ceiling effect than other commonly used measures of naming. To our knowledge, this represents the largest published independent validation study of the NAB Naming Test in a clinical sample. Our findings suggest that the NAB Naming Test demonstrates adequate validity and reliability and merits consideration in the test arsenal of clinical neuropsychologists.

  20. Life prediction of OLED for constant-stress accelerated degradation tests using luminance decaying model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jianping, E-mail: jpzhanglzu@163.com [College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Li, Wenbin [College of Energy and Mechanical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Cheng, Guoliang; Chen, Xiao [Shanghai Tianyi Electric Co., Ltd., Shanghai 201611 (China); Wu, Helen [School of Computing, Engineering and Mathematics, University of Western Sydney, Sydney 2751 (Australia); Herman Shen, M.-H. [Department of Mechanical and Aerospace Engineering, The Ohio State University, OH 43210 (United States)

    2014-10-15

    In order to acquire the life information of organic light emitting diode (OLED), three groups of constant stress accelerated degradation tests are performed to obtain the luminance decaying data of samples under the condition that the luminance and the current are respectively selected as the indicator of performance degradation and the test stress. Weibull function is applied to describe the relationship between luminance decaying and time, least square method (LSM) is employed to calculate the shape parameter and scale parameter, and the life prediction of OLED is achieved. The numerical results indicate that the accelerated degradation test and the luminance decaying model reveal the luminance decaying law of OLED. The luminance decaying formula fits the test data very well, and the average error of fitting value compared with the test data is small. Furthermore, the accuracy of the OLED life predicted by luminance decaying model is high, which enable rapid estimation of OLED life and provide significant guidelines to help engineers make decisions in design and manufacturing strategy from the aspect of reliability life. - Highlights: • We gain luminance decaying data by accelerated degradation tests on OLED. • The luminance decaying model objectively reveals the decaying law of OLED luminance. • The least square method (LSM) is employed to calculate Weibull parameters. • The plan designed for accelerated degradation tests proves to be feasible. • The accuracy of the OLED life and the luminance decaying fitting formula is high.

  1. Life prediction of OLED for constant-stress accelerated degradation tests using luminance decaying model

    International Nuclear Information System (INIS)

    Zhang, Jianping; Li, Wenbin; Cheng, Guoliang; Chen, Xiao; Wu, Helen; Herman Shen, M.-H.

    2014-01-01

    In order to acquire the life information of organic light emitting diode (OLED), three groups of constant stress accelerated degradation tests are performed to obtain the luminance decaying data of samples under the condition that the luminance and the current are respectively selected as the indicator of performance degradation and the test stress. Weibull function is applied to describe the relationship between luminance decaying and time, least square method (LSM) is employed to calculate the shape parameter and scale parameter, and the life prediction of OLED is achieved. The numerical results indicate that the accelerated degradation test and the luminance decaying model reveal the luminance decaying law of OLED. The luminance decaying formula fits the test data very well, and the average error of fitting value compared with the test data is small. Furthermore, the accuracy of the OLED life predicted by luminance decaying model is high, which enable rapid estimation of OLED life and provide significant guidelines to help engineers make decisions in design and manufacturing strategy from the aspect of reliability life. - Highlights: • We gain luminance decaying data by accelerated degradation tests on OLED. • The luminance decaying model objectively reveals the decaying law of OLED luminance. • The least square method (LSM) is employed to calculate Weibull parameters. • The plan designed for accelerated degradation tests proves to be feasible. • The accuracy of the OLED life and the luminance decaying fitting formula is high

  2. Accelerated aging as vigor test for sunn hemp seeds

    OpenAIRE

    Silva, Clíssia Barboza da; Barbosa, Rafael Marani; Vieira, Roberval Daiton

    2016-01-01

    ABSTRACT: This study aimed to determine the most appropriate method to assess the sunn hemp ( Crotalaria juncea L.) seed vigor in the accelerated aging test. Five seed lots from harvest 2007/2008 were evaluated for germination, vigor and seedling emergence in the field. Accelerated aging test was performed at 41°C during 48, 72 and 96 hours, with and without sodium chloride saturated solution. Then, the promising procedure was also performed for 2008/2009 and 2009/2010 harvests. In the tradit...

  3. Accelerated aging as vigor test for sunn hemp seeds

    OpenAIRE

    Silva,Clíssia Barboza da; Barbosa,Rafael Marani; Vieira,Roberval Daiton

    2017-01-01

    ABSTRACT: This study aimed to determine the most appropriate method to assess the sunn hemp ( Crotalaria juncea L.) seed vigor in the accelerated aging test. Five seed lots from harvest 2007/2008 were evaluated for germination, vigor and seedling emergence in the field. Accelerated aging test was performed at 41°C during 48, 72 and 96 hours, with and without sodium chloride saturated solution. Then, the promising procedure was also performed for 2008/2009 and 2009/2010 harvests. In the tradit...

  4. Reliability and maintainability data acquisition in equipment development tests

    International Nuclear Information System (INIS)

    Haire, M.J.; Gift, E.H.

    1983-10-01

    The need for collection of reliability, maintainability, and availability data adds a new dimension to the data acquisition requirements of equipment development tests. This report describes the reliability and maintainability data that are considered necessary to ensure that sufficient and high quality data exist for a comprehensive, quantitative evaluation of equipment and system availability. These necessary data are presented as a set of data collection forms. Three data acquisition forms are discussed: an inventory and technical data form, which is filed by the design engineer when the design is finished or the equipment is received; an event report form, which is completed by the senior test operator at each shutdown; and a maintainability report, which is a collaborative effort between senior operators and lead engineers and is completed on restart. In addition, elements of a reliability, maintainability evaluation program are described. Emphasis is placed on the role of data, its storage, and use in such a program

  5. Design and test of a superconducting magnet in a linear accelerator for an Accelerator Driven Subcritical System

    International Nuclear Information System (INIS)

    Peng, Quanling; Xu, Fengyu; Wang, Ting; Yang, Xiangchen; Chen, Anbin; Wei, Xiaotao; Gao, Yao; Hou, Zhenhua; Wang, Bing; Chen, Yuan; Chen, Haoshu

    2014-01-01

    A batch superconducting solenoid magnet for the ADS proton linear accelerator has been designed, fabricated, and tested in a vertical dewar in Sept. 2013. A total of ten superconducting magnets will be installed into two separate cryomodules. Each cryomodule contains six superconducting spoke RF cavities for beam acceleration and five solenoid magnets for beam focusing. The multifunction superconducting magnet contains a solenoid for beam focusing and two correctors for orbit correction. The design current for the solenoid magnet is 182 A. A quench performance test shows that the operating current of the solenoid magnet can reach above 300 A after natural quenching on three occasions during current ramping (260 A, 268 A, 308 A). The integrated field strength and leakage field at the nearby superconducting spoke cavities all meet the design requirements. The vertical test checked the reliability of the test dewar and the quench detection system. This paper presents the physical and mechanical design of the batch magnets, the quench detection technique, field measurements, and a discussion of the residual field resulting from persistent current effects

  6. An accelerated test method for efflorescence in clay bricks

    International Nuclear Information System (INIS)

    Beggan, John Edward

    1998-01-01

    An investigation into the creation of accelerated efflorescence in clay bricks was undertaken with a view to creating a viable test procedure for determining efflorescence potential. The testing programme incorporated ambient conditions similar to those which promote efflorescence growth in bricks in use. Theoretical investigations into the physical mechanism underlying the creation of efflorescence directed the attempts to accelerate the process. It was found that calcium sulphate efflorescence could not be sufficiently accelerated such that a useful efflorescence test procedure could be proposed. The inability to produce accelerated efflorescence in brick samples was attributed to limitations associated with time dependent salt diffusion in the efflorescence mechanism. The preliminary testing that was undertaken into the creation of efflorescence prompted the use of acid assisted methods to accelerate efflorescence. The acid assisted method that was adopted to provide a possible indication of efflorescence potential relies upon the transformation of low solubility calcium to a more soluble form. The movement of the transformed salt is then induced by cyclic temperature exposure at temperatures similar to those experienced in Spring. The appearance of the transformed calcium salt on the surface of the brick specimen provides an indication of the efflorescence potential. Brick piers constructed on an exposed site and monitored over a 12 month period provided information on the validity of the acid assisted test method. The efflorescence observed on the piers correlated well with that predicted by the acid assisted test, suggesting that the new test has the potential to accurately predict the efflorescence potential of clay bricks Relationships between other properties such as air permeability, sorptivity and tensile strength were investigated such that an alternative method of predicting efflorescence could be achieved. It was found that (within the bounds of the

  7. Test-retest reliability of the multifocal photopic negative response.

    Science.gov (United States)

    Van Alstine, Anthony W; Viswanathan, Suresh

    2017-02-01

    To assess the test-retest reliability of the multifocal photopic negative response (mfPhNR) of normal human subjects. Multifocal electroretinograms were recorded from one eye of 61 healthy adult subjects on two separate days using a Visual Evoked Response Imaging System software version 4.3 (EDI, San Mateo, California). The visual stimulus delivered on a 75-Hz monitor consisted of seven equal-sized hexagons each subtending 12° of visual angle. The m-step exponent was 9, and the m-sequence was slowed to include at least 30 blank frames after each flash. Only the first slice of the first-order kernel was analyzed. The mfPhNR amplitude was measured at a fixed time in the trough from baseline (BT) as well as at the same fixed time in the trough from the preceding b-wave peak (PT). Additionally, we also analyzed BT normalized either to PT (BT/PT) or to the b-wave amplitude (BT/b-wave). The relative reliability of test-retest differences for each test location was estimated by the Wilcoxon matched-pair signed-rank test and intraclass correlation coefficients (ICC). Absolute test-retest reliability was estimated by Bland-Altman analysis. The test-retest amplitude differences for neither of the two measurement techniques were statistically significant as determined by Wilcoxon matched-pair signed-rank test. PT measurements showed greater ICC values than BT amplitude measurements for all test locations. For each measurement technique, the ICC value of the macular response was greater than that of the surrounding locations. The mean test-retest difference was close to zero for both techniques at each of the test locations, and while the coefficient of reliability (COR-1.96 times the standard deviation of the test-retest difference) was comparable for the two techniques at each test location when expressed in nanovolts, the %COR (COR normalized to the mean test and retest amplitudes) was superior for PT than BT measurements. The ICC and COR were comparable for the BT/PT and

  8. Reliability and validity of two isometric squat tests.

    Science.gov (United States)

    Blazevich, Anthony J; Gill, Nicholas; Newton, Robert U

    2002-05-01

    The purpose of the present study was first to examine the reliability of isometric squat (IS) and isometric forward hack squat (IFHS) tests to determine if repeated measures on the same subjects yielded reliable results. The second purpose was to examine the relation between isometric and dynamic measures of strength to assess validity. Fourteen male subjects performed maximal IS and IFHS tests on 2 occasions and 1 repetition maximum (1-RM) free-weight squat and forward hack squat (FHS) tests on 1 occasion. The 2 tests were found to be highly reliable (intraclass correlation coefficient [ICC](IS) = 0.97 and ICC(IFHS) = 1.00). There was a strong relation between average IS and 1-RM squat performance, and between IFHS and 1-RM FHS performance (r(squat) = 0.77, r(FHS) = 0.76; p squat and FHS test performances (r squat and FHS test performance can be attributed to differences in the movement patterns of the tests

  9. Gearbox Reliability Collaborative Phase 3 Gearbox 2 Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Link, H.; Keller, J.; Guo, Y.; McNiff, B.

    2013-04-01

    Gearboxes in wind turbines have not been achieving their expected design life even though they commonly meet or exceed the design criteria specified in current design standards. One of the basic premises of the National Renewable Energy Laboratory (NREL) Gearbox Reliability Collaborative (GRC) is that the low gearbox reliability results from the absence of critical elements in the design process or insufficient design tools. Key goals of the GRC are to improve design approaches and analysis tools and to recommend practices and test methods resulting in improved design standards for wind turbine gearboxes that lower the cost of energy (COE) through improved reliability. The GRC uses a combined gearbox testing, modeling and analysis approach, along with a database of information from gearbox failures collected from overhauls and investigation of gearbox condition monitoring techniques to improve wind turbine operations and maintenance practices. Testing of Gearbox 2 (GB2) using the two-speed turbine controller that has been used in prior testing. This test series will investigate non-torque loads, high-speed shaft misalignment, and reproduction of field conditions in the dynamometer. This test series will also include vibration testing using an eddy-current brake on the gearbox's high speed shaft.

  10. Test of Creative Imagination: Validity and Reliability Study

    Science.gov (United States)

    Gundogan, Aysun; Ari, Meziyet; Gonen, Mubeccel

    2013-01-01

    The purpose of this study was to investigate validity and reliability of the test of creative imagination. This study was conducted with the participation of 1000 children, aged between 9-14 and were studying in six primary schools in the city center of Denizli Province, chosen by cluster ratio sampling. In the study, it was revealed that the…

  11. New design algorithm and reliability testing of solar powered near ...

    African Journals Online (AJOL)

    New design algorithm and reliability testing of solar powered near-space flight vehicle for defense and security. ... To overcome this problem, we propose a pseudo-satellite system where telecommunication devices are carried on a perpetually flying solar aircraft cruising at stratospheric altitude. Our aircraft will combine ...

  12. Construct validity and reliability of automated body reaction test ...

    African Journals Online (AJOL)

    Automated Body Reaction Test (ABRT) is a new device for skills and physical assessment instrument to measure ability on react, move quickly and accurately in accordance with stimulus. A total of 474 subjects aged 7-17 years old were randomly selected for the construct validity (n=330) and reliability (n=144). The ABRT ...

  13. Molding compound trends in a denser packaging world: Qualification tests and reliability concerns

    Science.gov (United States)

    Nguyen, L. T.; Lo, R. H. Y.; Chen, A. S.; Belani, J. G.

    1993-12-01

    Molding compound development has traditionally been driven by the memory market, then subsequent applications filter down to other IC technologies such as logic, analog, and ASIC. However, this strategy has changed lately with the introduction of thin packages such as PQFP & TSOP. Rather than targeting a compound for a family of IC such as DRAM or SRAM, compound development efforts are now focused at specific classes of packages. The configurations of these thin packages impose new functional requirements that need to be revisited to provide the optimized combination of properties. The evolution of qualification tests mirrors the advances in epoxy and compounding technologies. From the first standard novolac-based epoxies of the 1970s to the latest 3(sup rd)-generation ultra-low stress materials, longer test times at increasingly harsher environments were achieved. This paper benchmarks the current reliability tests used by the electronic industry, examines those tests that affect and are affected by the molding compounds, discusses the relevance of accelerated testing, and addresses the major reliability issues facing current molding compound development efforts. Six compound-related reliability concerns were selected: moldability, package stresses, package cracking, halogen-induced intermetallic growth at bond pads, moisture-induced corrosion, and interfacial delamination. Causes of each failure type are surveyed and remedies are recommended. Accelerated tests are designed to apply to a limited quantity of devices, bias, or environmental conditions larger than usual ratings, to intensify failure mechanisms that would occur under normal operating conditions. The observed behavior is then extrapolated from the lot to the entire population. Emphasis is on compressing the time necessary to obtain reliability data. This approach has two main drawbacks. With increasingly complex devices, even accelerated tests are expensive. And with new technologies, it becomes

  14. MEMS Reliability: Infrastructure, Test Structures, Experiments, and Failure Modes

    Energy Technology Data Exchange (ETDEWEB)

    TANNER,DANELLE M.; SMITH,NORMAN F.; IRWIN,LLOYD W.; EATON,WILLIAM P.; HELGESEN,KAREN SUE; CLEMENT,J. JOSEPH; MILLER,WILLIAM M.; MILLER,SAMUEL L.; DUGGER,MICHAEL T.; WALRAVEN,JEREMY A.; PETERSON,KENNETH A.

    2000-01-01

    The burgeoning new technology of Micro-Electro-Mechanical Systems (MEMS) shows great promise in the weapons arena. We can now conceive of micro-gyros, micro-surety systems, and micro-navigators that are extremely small and inexpensive. Do we want to use this new technology in critical applications such as nuclear weapons? This question drove us to understand the reliability and failure mechanisms of silicon surface-micromachined MEMS. Development of a testing infrastructure was a crucial step to perform reliability experiments on MEMS devices and will be reported here. In addition, reliability test structures have been designed and characterized. Many experiments were performed to investigate failure modes and specifically those in different environments (humidity, temperature, shock, vibration, and storage). A predictive reliability model for wear of rubbing surfaces in microengines was developed. The root causes of failure for operating and non-operating MEMS are discussed. The major failure mechanism for operating MEMS was wear of the polysilicon rubbing surfaces. Reliability design rules for future MEMS devices are established.

  15. Quick setup of test unit for accelerator control system

    International Nuclear Information System (INIS)

    Fu, W.; D'Ottavio, T.; Gassner, D.; Nemesure, S.; Morris, J.

    2011-01-01

    Testing a single hardware unit of an accelerator control system often requires the setup of a program with graphical user interface. Developing a dedicated application for a specific hardware unit test could be time consuming and the application may become obsolete after the unit tests. This paper documents a methodology for quick design and setup of an interface focused on performing unit tests of accelerator equipment with minimum programming work. The method has three components. The first is a generic accelerator device object (ADO) manager which can be used to setup, store, and log testing controls parameters for any unit testing system. The second involves the design of a TAPE (Tool for Automated Procedure Execution) sequence file that specifies and implements all te testing and control logic. The sting third is the design of a PET (parameter editing tool) page that provides the unit tester with all the necessary control parameters required for testing. This approach has been used for testing the horizontal plane of the Stochastic Cooling Motion Control System at RHIC.

  16. Reliability Evaluation of Concentric Butterfly Valve Using Statistical Hypothesis Test

    International Nuclear Information System (INIS)

    Chang, Mu Seong; Choi, Jong Sik; Choi, Byung Oh; Kim, Do Sik

    2015-01-01

    A butterfly valve is a type of flow-control device typically used to regulate a fluid flow. This paper presents an estimation of the shape parameter of the Weibull distribution, characteristic life, and B10 life for a concentric butterfly valve based on a statistical analysis of the reliability test data taken before and after the valve improvement. The difference in the shape and scale parameters between the existing and improved valves is reviewed using a statistical hypothesis test. The test results indicate that the shape parameter of the improved valve is similar to that of the existing valve, and that the scale parameter of the improved valve is found to have increased. These analysis results are particularly useful for a reliability qualification test and the determination of the service life cycles

  17. Reliable and sensitive physical testing of elite trapeze sailors

    DEFF Research Database (Denmark)

    Bay, Jonathan; Bojsen-Møller, Jens; Nordsborg, Nikolai Baastrup

    2018-01-01

    It was investigated, if a newly developed discipline specific test for elite-level trapeze sailors is reli-able and sensitive. Furthermore, the physical demands of trapeze sailing were examined. In part 1, nine national team athletes were accustomed to a simulated sailing test, which subsequently....... 265 ± 45W, Psailing was 54.5 ± 7.2% VO2max , 75.1 ± 3.1% HRmax and 5.8 ± 2.7 mM, respectively. However, VO2 and HR were substantially higher for periods of the race...... as peak values were 83.5 ± 11.4% and 89.9 ± 1.7% of max, respectively. In conclusion, the present test is reliable and sensitive, thus providing a sailing specific alternative to traditional physical testing of elite trapeze sailors. Additionally, on-water rac-ing requires moderate aerobic energy...

  18. Reliability Evaluation of Concentric Butterfly Valve Using Statistical Hypothesis Test

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Mu Seong; Choi, Jong Sik; Choi, Byung Oh; Kim, Do Sik [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

    2015-12-15

    A butterfly valve is a type of flow-control device typically used to regulate a fluid flow. This paper presents an estimation of the shape parameter of the Weibull distribution, characteristic life, and B10 life for a concentric butterfly valve based on a statistical analysis of the reliability test data taken before and after the valve improvement. The difference in the shape and scale parameters between the existing and improved valves is reviewed using a statistical hypothesis test. The test results indicate that the shape parameter of the improved valve is similar to that of the existing valve, and that the scale parameter of the improved valve is found to have increased. These analysis results are particularly useful for a reliability qualification test and the determination of the service life cycles.

  19. Brookhaven National Laboratory's Accelerator Test Facility: research highlights and plans

    Science.gov (United States)

    Pogorelsky, I. V.; Ben-Zvi, I.

    2014-08-01

    The Accelerator Test Facility (ATF) at Brookhaven National Laboratory has served as a user facility for accelerator science for over a quarter of a century. In fulfilling this mission, the ATF offers the unique combination of a high-brightness 80 MeV electron beam that is synchronized to a 1 TW picosecond CO2 laser. We unveil herein our plan to considerably expand the ATF's floor space with an upgrade of the electron beam's energy to 300 MeV and the CO2 laser's peak power to 100 TW. This upgrade will propel the ATF even further to the forefront of research on advanced accelerators and radiation sources, supporting the most innovative ideas in this field. We discuss emerging opportunities for scientific breakthroughs, including the following: plasma wakefield acceleration studies in research directions already active at the ATF; laser wakefield acceleration (LWFA), where the longer laser wavelengths are expected to engender a proportional increase in the beam's charge while our linac will assure, for the first time, the opportunity to undertake detailed studies of seeding and staging of the LWFA; proton acceleration to the 100-200 MeV level, which is essential for medical applications; and others.

  20. The BNL Accelerator Test Facility and experimental program

    International Nuclear Information System (INIS)

    Ben-Zvi, I.; State Univ. of New York, Stony Brook, NY

    1992-01-01

    The Accelerator Test Facility (ATF) at BNL is a users' facility for experiments in Accelerator and Beam Physics. The ATF provides high brightness electron beams and high-power laser pulses synchronized to the electron beam, suitable for studies of new methods of high-gradient acceleration and state-of-the-art Free-Electron Lasers. The electrons are produced by a laser photocathode rf gun and accelerated to 50 MeV by two traveling wave accelerator sections. The lasers include a 10 mJ, 10 ps ND:YAG laser and a 500 mJ, 10 to 100 ps C0 2 laser. A number of users from National Laboratories, universities and industry take part in experiments at the ATF. The experimental program includes various laser acceleration schemes, Free-Electron Laser experiments and a program on the development of high-brightness electron beams. The ATF's experimental program commenced in early 1991 at an energy of about 4 MeV. The full program, with 50 MeV and the high-power laser will begin operation this year

  1. The BNL Accelerator Test Facility and experimental program

    International Nuclear Information System (INIS)

    Ben-Zvi, I.; State Univ. of New York, Stony Brook, NY

    1991-01-01

    The Accelerator Test Facility (ATF) at BNL is a users' facility for experiments in Accelerator and Beam Physics. The ATF provides high brightness electron beams and high power laser pulses synchronized to the electron beam, suitable for studies of new methods of high gradient acceleration and state of the art free electron lasers. The electrons are produced by a laser photocathode rf gun and accelerated to 50 to 100 MeV by two traveling wave accelerator sections. The lasers include a 10 mJ, 10 ps Nd:YAG laser and a 100 mJ, 10 ps CO 2 laser. A number of users from National Laboratories, universities and industry take part in experiments at the ATF. The experimental program includes various acceleration schemes, Free-Electron Laser experiments and a program on the development of high brightness electron beams. The AFT's experimental program commenced in early 1991 at an energy of about 4 MeV. The full program, with 50 MeV and the High power laser will begin operation this year. 28 refs., 4 figs

  2. A test accelerator for the next linear collider

    International Nuclear Information System (INIS)

    Ruth, R.D.; Adolphsen, C.; Bane, K.; Boyce, R.F.; Burke, D.L.; Callin, R.; Caryotakis, G.; Cassel, R.; Clark, S.L.; Deruyter, H.; Fant, K.; Fuller, R.; Heifets, S.; Hoag, H.; Humphrey, R.; Kheifets, S.; Koontz, R.; Lavine, T.; Loew, G.A.; Menegat, A.; Miller, R.H.; Paterson, J.M.; Pearson, C.; Phillips, R.; Rifkin, J.; Spencer, J.; Tantawi, S.; Thompson, K.A.; Vlieks, A.; Vylet, V.; Wang, J.W.; Wilson, P.B.; Yeremian, A.; Youngman, B.; Kroll, N.M.; Nantista, C.

    1993-07-01

    At SLAC, the authors are pursuing the design of a Next Linear Collider (NLC) which would begin with a center-of-mass energy of 0.5 TeV, and be upgradable to at least 1.0 TeV. To achieve this high energy, they have been working on the development of a high-gradient 11.4-GHz (X-band) linear accelerator for the main linac of the collider. In this paper, they present the design of a open-quotes Next Linear Collider Test Acceleratorclose quotes (NLCTA). The goal of the NLCTA is to incorporate the new technologies of X-band accelerator structures, RF pulse compression systems and klystrons into a short linac which will then be a test bed for beam dynamics issues related to high-gradient acceleration

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

    Directory of Open Access Journals (Sweden)

    Abeer Abd-Alla EL-Helbawy

    2016-12-01

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

  5. Gearbox Reliability Collaborative Phase 3 Gearbox 3 Test Plan

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Jonathan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wallen, Robb [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-10-01

    This document describes the Phase 3 test plan for the Gearbox Reliability Collaborative Gearbox #3. The primary test objective is to measure the planetary load sharing characteristics in the same conditions as the original gearbox design. If the measured load-sharing characteristics are close to the design model, the projected three-times improvement in planetary section predicted fatigue life and the efficacy of preloaded tapered roller bearings in mitigating the planetary bearing fatigue failure mode will have been demonstrated.

  6. Electrical performance characteristics of the SSC Accelerator System String Test

    International Nuclear Information System (INIS)

    Robinson, W.; Burgett, W.; Dombeck, T.; Gannon, J.; Kraushaar, P.; McInturff, A.; Savord, T.; Tool, G.

    1993-05-01

    The string test facility was constructed to provide a development test bed for the arc regions of the Superconducting Super Collider (SSC). Significant effort has been devoted to the development and testing of superconducting magnets, spools, and accelerator control systems required for the SSC. The string test facility provides the necessary environment required to evaluate the operational performance of these components as they are configured as an accelerator lens in the collider. This discussion will review the results of high current testing of the string conducted to evaluate magnet element uniformity and compatibility, the splice resistance used to connect the magnets, and system response to various quench conditions. Performance results of the spools, energy bypass systems, energy dump, and the power supply system are also discussed

  7. Electrical performance characteristics of the SSC Accelerator System String Test

    International Nuclear Information System (INIS)

    Robinson, W.; Burgett, W.; Dombeck, T.; Gannon, J.; Kraushaar, P.; McInturff, A.; Savord, T.; Tool, G.

    1993-01-01

    The string test facility was constructed to provide a development test bed for the arc regions of the Superconducting Super Collider (SSC). Significant effort has been devoted to the development and testing of superconducting magnets, spools, and accelerator control systems required for the SSC. The string test facility provides the necessary environment required to evaluate the operational performance of these components as they are configured as an accelerator lens in the collider. This discussion will review the results of high current testing of the string conducted to evaluate magnet element uniformity and compatibility, the splice resistance used to connect the magnets, and system response to various quench conditions. Performance results of the spools, energy bypass systems, energy dump, and the power supply system are also discussed

  8. Inspection of piping wall loss with flow accelerated corrosion accelerated simulation test

    International Nuclear Information System (INIS)

    Ryu, Kyung Ha; Kim, Ji Hak; Hwang, Il Soon; Lee, Na Young; Kim, Ji Hyun

    2009-01-01

    Flow Accelerated Corrosion (FAC) has become a hot issue for aging of passive components. Ultrasonic Technique (UT) has been adopted to inspect the secondary piping of Nuclear Power Plants (NPPs). UT, however, uses point detection method, which results in numerous detecting points and thus takes time. We developed an Equipotential Switching Direct Current Potential Drop (ES-DCPD) method to monitor the thickness of piping that covers wide range of piping at once time. Since the ES-DCPD method covers area, not a point, it needs less monitoring time. This can be a good approach to broad carbon steel piping system such as secondary piping of NPPs. In this paper, FAC accelerated simulation test results is described. We realized accelerated FAC phenomenon by 2 times test: 23.7% thinning in 216.7 hours and 51% thinning in 795 hours. These were monitored by ES-DCPD and traditional UT. Some parameters of water chemistry are monitored and controlled to accelerate FAC process. As sensitive factors on FAC, temperature and pH was changed during the test. The wall loss monitored results reflected these changes of water chemistry successfully. Developed electrodes are also applied to simulation loop to monitor water chemistry. (author)

  9. Reliability analysis of structures under periodic proof tests in service

    Science.gov (United States)

    Yang, J.-N.

    1976-01-01

    A reliability analysis of structures subjected to random service loads and periodic proof tests treats gust loads and maneuver loads as random processes. Crack initiation, crack propagation, and strength degradation are treated as the fatigue process. The time to fatigue crack initiation and ultimate strength are random variables. Residual strength decreases during crack propagation, so that failure rate increases with time. When a structure fails under periodic proof testing, a new structure is built and proof-tested. The probability of structural failure in service is derived from treatment of all the random variables, strength degradations, service loads, proof tests, and the renewal of failed structures. Some numerical examples are worked out.

  10. Gearbox Reliability Collaborative Phase 3 Gearbox 2 Test Report

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Jonathan; Wallen, Robb

    2015-06-10

    Many gearboxes in wind turbines have not been achieving their expected design life [1]; they do, however, commonly meet or exceed the design criteria specified in current standards in the gear, bearing, and wind turbine industry as well as third-party certification criteria. The cost of gearbox replacements and rebuilds, as well as the downtime associated with these failures, has elevated the cost of wind energy. In 2006, the U.S. Department of Energy established the National Renewable Energy Laboratory (NREL) Gearbox Reliability Collaborative (GRC). Its key goal is to understand the root causes of premature gearbox failures and improve their reliability [2]. The GRC is examining a hypothesis that the gap between design-estimated and actual wind turbine gearbox reliability is caused by underestimation of loads, inaccurate design tools, the absence of critical elements in the design process, or insufficient testing. This test report describes the recent tests of GRC gearbox (GB) 2 in the National Wind Technology Center (NWTC) dynamometer and documents any modifications to the original test plan [3]. In this manner, it serves as a guide for interpreting the publicly released data sets with brief analyses to illustrate the data. Specific objectives of the test were to assess the effect of dynamic nontorque load (NTL) on the planetary section, generator misalignment on the highspeed shaft (HSS), and field representative conditions on the gearbox in general. Detailed analysis of those test objectives will be presented in subsequent publications.

  11. Reliability assessment for safety critical systems by statistical random testing

    International Nuclear Information System (INIS)

    Mills, S.E.

    1995-11-01

    In this report we present an overview of reliability assessment for software and focus on some basic aspects of assessing reliability for safety critical systems by statistical random testing. We also discuss possible deviations from some essential assumptions on which the general methodology is based. These deviations appear quite likely in practical applications. We present and discuss possible remedies and adjustments and then undertake applying this methodology to a portion of the SDS1 software. We also indicate shortcomings of the methodology and possible avenues to address to follow to address these problems. (author). 128 refs., 11 tabs., 31 figs

  12. Reliability assessment for safety critical systems by statistical random testing

    Energy Technology Data Exchange (ETDEWEB)

    Mills, S E [Carleton Univ., Ottawa, ON (Canada). Statistical Consulting Centre

    1995-11-01

    In this report we present an overview of reliability assessment for software and focus on some basic aspects of assessing reliability for safety critical systems by statistical random testing. We also discuss possible deviations from some essential assumptions on which the general methodology is based. These deviations appear quite likely in practical applications. We present and discuss possible remedies and adjustments and then undertake applying this methodology to a portion of the SDS1 software. We also indicate shortcomings of the methodology and possible avenues to address to follow to address these problems. (author). 128 refs., 11 tabs., 31 figs.

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

    International Nuclear Information System (INIS)

    Kamaya, Masayuki; Fukumura, Takuya; Totsuka, Nobuo

    2003-01-01

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

  14. Test of the law of gravitation at small accelerations

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, H. [Wuppertal Univ. (Germany); Lohrmann, E.; Schubert, S. [Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; Bartel, W.; Glazov, A.; Loehr, B.; Niebuhr, C.; Wuensch, E. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Joensson, L.; Kempf, G. [Lund Univ. (Sweden)

    2011-12-15

    Newton's Law of Gravitation has been tested at small values a of the acceleration, down to a {approx}10{sup -10} ms{sup -2}, the approximate value of MOND's constant a{sub 0}. No deviations were found. (orig.)

  15. Testing a Fourier Accelerated Hybrid Monte Carlo Algorithm

    OpenAIRE

    Catterall, S.; Karamov, S.

    2001-01-01

    We describe a Fourier Accelerated Hybrid Monte Carlo algorithm suitable for dynamical fermion simulations of non-gauge models. We test the algorithm in supersymmetric quantum mechanics viewed as a one-dimensional Euclidean lattice field theory. We find dramatic reductions in the autocorrelation time of the algorithm in comparison to standard HMC.

  16. Accelerated pavement testing efforts using the heavy vehicle simulator

    CSIR Research Space (South Africa)

    Du Plessis, Louw

    2017-10-01

    Full Text Available This paper provides a brief description of the technological developments involved in the development and use of the Heavy Vehicle Simulator (HVS) accelerated pavement testing equipment. This covers the period from concept in the late 1960’s...

  17. Photovoltaic module reliability improvement through application testing and failure analysis

    Science.gov (United States)

    Dumas, L. N.; Shumka, A.

    1982-01-01

    During the first four years of the U.S. Department of Energy (DOE) National Photovoltatic Program, the Jet Propulsion Laboratory Low-Cost Solar Array (LSA) Project purchased about 400 kW of photovoltaic modules for test and experiments. In order to identify, report, and analyze test and operational problems with the Block Procurement modules, a problem/failure reporting and analysis system was implemented by the LSA Project with the main purpose of providing manufacturers with feedback from test and field experience needed for the improvement of product performance and reliability. A description of the more significant types of failures is presented, taking into account interconnects, cracked cells, dielectric breakdown, delamination, and corrosion. Current design practices and reliability evaluations are also discussed. The conducted evaluation indicates that current module designs incorporate damage-resistant and fault-tolerant features which address field failure mechanisms observed to date.

  18. Test-retest reliability for aerodynamic measures of voice.

    Science.gov (United States)

    Awan, Shaheen N; Novaleski, Carolyn K; Yingling, Julie R

    2013-11-01

    The purpose of this study was to investigate the intrasubject reliability of aerodynamic characteristics of the voice within typical/normal speakers across testing sessions using the Phonatory Aerodynamic System (PAS 6600; KayPENTAX, Montvale, NJ). Participants were 60 healthy young adults (30 males and 30 females) between the ages 18 and 31 years with perceptually typical voice. Participants were tested using the PAS 6600 (Phonatory Aerodynamic System) on two separate days with approximately 1 week between each session at approximately the same time of day. Four PAS protocols were conducted (vital capacity, maximum sustained phonation, comfortable sustained phonation, and voicing efficiency) and measures of expiratory volume, maximum phonation time, mean expiratory airflow (during vowel production) and target airflow (obtained via syllable repetition), peak air pressure, aerodynamic power, aerodynamic resistance, and aerodynamic efficiency were obtained during each testing session. Associated acoustic measures of vocal intensity and frequency were also collected. All phonations were elicited at comfortable pitch and loudness. All aerodynamic and associated variables evaluated in this study showed useable test-retest reliability (ie, intraclass correlation coefficients [ICCs] ≥ 0.60). A high degree of mean test-retest reliability was found across all subjects for aerodynamic and associated acoustic measurements of vital capacity, maximum sustained phonation, glottal resistance, and vocal intensity (all with ICCs > 0.75). Although strong ICCs were observed for measures of glottal power and mean expiratory airflow in males, weaker overall results for these measures (ICC range: 0.60-0.67) were observed in females subjects and sizable coefficients of variation were observed for measures of power, resistance, and efficiency in both men and women. Differences in degree of reliability from measure to measure were revealed in greater detail using methods such as ICCs and

  19. Preliminary temperature Accelerated Life Test (ALT) on III-V commercial concentrator triple-junction solar cells

    OpenAIRE

    Espinet González, Pilar; Algora del Valle, Carlos; Orlando Carrillo, Vincenzo; Nuñez Mendoza, Neftali; Vázquez López, Manuel; Bautista Villares, Jesus; Xiugang, He; Barrutia Poncela, Laura; Rey-Stolle Prado, Ignacio; Araki, Kenji

    2012-01-01

    A quantitative temperature accelerated life test on sixty GaInP/GaInAs/Ge triple-junction commercial concentrator solar cells is being carried out. The final objective of this experiment is to evaluate the reliability, warranty period, and failure mechanism of high concentration solar cells in a moderate period of time. The acceleration of the degradation is realized by subjecting the solar cells at temperatures markedly higher than the nominal working temperature under a concentrator Three e...

  20. Model- and calibration-independent test of cosmic acceleration

    International Nuclear Information System (INIS)

    Seikel, Marina; Schwarz, Dominik J.

    2009-01-01

    We present a calibration-independent test of the accelerated expansion of the universe using supernova type Ia data. The test is also model-independent in the sense that no assumptions about the content of the universe or about the parameterization of the deceleration parameter are made and that it does not assume any dynamical equations of motion. Yet, the test assumes the universe and the distribution of supernovae to be statistically homogeneous and isotropic. A significant reduction of systematic effects, as compared to our previous, calibration-dependent test, is achieved. Accelerated expansion is detected at significant level (4.3σ in the 2007 Gold sample, 7.2σ in the 2008 Union sample) if the universe is spatially flat. This result depends, however, crucially on supernovae with a redshift smaller than 0.1, for which the assumption of statistical isotropy and homogeneity is less well established

  1. Accelerated aging tests of liners for uranium mill tailings disposal

    International Nuclear Information System (INIS)

    Barnes, S.M.; Buelt, J.L.; Hale, V.Q.

    1981-11-01

    This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost information prompted the selection of a catalytic airblown asphalt membrane and a sodium bentonite-amended soil for fiscal year 1981 field testing

  2. Sensory shelf life of mantecoso cheese using accelerated testing

    OpenAIRE

    Sánchez-González, Jesús A.; Pérez, Joel A.

    2016-01-01

    The aim of this research was to estimate sensory shelf life of "huacariz" and "cefop" mantecoso cheese, vacuum packaging: "cefop" and packaging to the atmospheric pressure: "huacariz"; brands marketed in Cajamarca, using accelerated shelf life testing. For this purpose, "huacariz" cheese was stored at 20, 28, 35 y 40 °C, while it was set at 20, 28, 35 °C storage for "cefop" cheese, performing acceptability sensory tests according to time storage with both 41 consumers constants. The results f...

  3. Test-Retest Reliability and Predictive Validity of the Implicit Association Test in Children

    Science.gov (United States)

    Rae, James R.; Olson, Kristina R.

    2018-01-01

    The Implicit Association Test (IAT) is increasingly used in developmental research despite minimal evidence of whether children's IAT scores are reliable across time or predictive of behavior. When test-retest reliability and predictive validity have been assessed, the results have been mixed, and because these studies have differed on many…

  4. Operation of the graded-β electron test accelerator

    International Nuclear Information System (INIS)

    Fraser, J.S.; McKeown, J.; McMichael, G.E.; Diamond, W.T.

    1976-01-01

    The Electron Test Accelerator has been built to model the behaviour of the high energy portion of a proton linear accelerator which would be suitable for breeding fissile material. The test accelerator and its control systems have been tested at 100% duty factor producing a beam of electrons at 1.5 MeV and currents up to 20 mA where the incident rf power is shared equally between the structure dissipation and the beam loading. The structure has performed satisfactorily in all respects at dissipation power densities up to 5 kW/cell where the mean energy gradient was 1.1 MeV/m. Experiments have been done on the beam loading effects in the coupling of the transmission line to the cavity, the amplitude depression in and phase tilt along the structure, and the phase lag of the structure field. The phase acceptance, the variation of transmission with buncher-accelerator phase shift and the beam energy spread are in qualitative agreement with beam dynamics calculations. (author)

  5. Reliability Testing the Die-Attach of CPV Cell Assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Bosco, N.; Sweet, C.; Kurtz, S.

    2011-02-01

    Results and progress are reported for a course of work to establish an efficient reliability test for the die-attach of CPV cell assemblies. Test vehicle design consists of a ~1 cm2 multijunction cell attached to a substrate via several processes. A thermal cycling sequence is developed in a test-to-failure protocol. Methods of detecting a failed or failing joint are prerequisite for this work; therefore both in-situ and non-destructive methods, including infrared imaging techniques, are being explored as a method to quickly detect non-ideal or failing bonds.

  6. Next Linear Collider Test Accelerator conceptual design report

    International Nuclear Information System (INIS)

    1993-08-01

    This document presents the scientific justification and the conceptual design for the open-quotes Next Linear Collider Test Acceleratorclose quotes (NLCTA) at SLAC. The goals of the NLCTA are to integrate the new technologies of X-band accelerator structures and rf systems being developed for the Next Linear Collider, to measure the growth of the open-quotes dark currentclose quotes generated by rf field emission in the accelerator, to demonstrate multi-bunch beam-loading energy compensation and suppression of higher-order deflecting modes, and to measure any transverse components of the accelerating field. The NLCTA will be a 42-meter-long beam line consisting, consecutively, of a thermionic-cathode gun, an X-band buncher, a magnetic chicane, six 1.8-meter-long sections of 11.4-GHz accelerator structure, and a magnetic spectrometer. Initially, the unloaded accelerating gradient will be 50 MV/m. A higher-gradient upgrade option eventually would increase the unloaded gradient to 100 MV/m

  7. Applying an overstress principle in accelerated testing of absorbing mechanisms

    Science.gov (United States)

    Tsyss, V. G.; Sergaeva, M. Yu; Sergaev, A. A.

    2018-04-01

    The relevance of using overstress test as a forced one to determine the pneumatic absorber lifespan was studied. The obtained results demonstrated that at low load overstress the relative error for the absorber lifespan evaluation is no more than 3%. This means that the test results spread has almost no effect on the lifespan evaluation, and this effect is several times less than that at high load overstress tests. Accelerated testing of absorbers with low load overstress is more acceptable since the relative error for the lifespan evaluation is negligible.

  8. High gradient tests of SLAC Linear Collider Accelerator Structures

    International Nuclear Information System (INIS)

    Wang, J.W.; Deruyter, H.; Eichner, J.; Fant, K.H.; Hoag, H.A.; Koontz, R.F.; Lavine, T.; Loew, G.A.; Loewen, R.; Menegat, L.

    1994-08-01

    This paper describes the current SLAC R ampersand D program to develop room temperature accelerator structures for the Next Linear Collider (NLC). The structures are designed to operate at 11.4 GHz at an accelerating gradient in the range of 50 to 100 MV/m. In the past year a 26 cm constant-impedance traveling-wave section, a 75 cm constant-impedance traveling-wave section, and a 1.8 m traveling-wave section with detuned deflecting modes have been high-power tested. The paper presents a brief description of the RF test setup, the design and manufacturing details of the structures, and a discussion of test results including field emission, RF processing, dark current spectrum and RF breakdown

  9. Solutions for acceleration measurement in vehicle crash tests

    Science.gov (United States)

    Dima, D. S.; Covaciu, D.

    2017-10-01

    Crash tests are useful for validating computer simulations of road traffic accidents. One of the most important parameters measured is the acceleration. The evolution of acceleration versus time, during a crash test, form a crash pulse. The correctness of the crash pulse determination depends on the data acquisition system used. Recommendations regarding the instrumentation for impact tests are given in standards, which are focused on the use of accelerometers as impact sensors. The goal of this paper is to present the device and software developed by authors for data acquisition and processing. The system includes two accelerometers with different input ranges, a processing unit based on a 32-bit microcontroller and a data logging unit with SD card. Data collected on card, as text files, is processed with a dedicated software running on personal computers. The processing is based on diagrams and includes the digital filters recommended in standards.

  10. A general Bayes weibull inference model for accelerated life testing

    International Nuclear Information System (INIS)

    Dorp, J. Rene van; Mazzuchi, Thomas A.

    2005-01-01

    This article presents the development of a general Bayes inference model for accelerated life testing. The failure times at a constant stress level are assumed to belong to a Weibull distribution, but the specification of strict adherence to a parametric time-transformation function is not required. Rather, prior information is used to indirectly define a multivariate prior distribution for the scale parameters at the various stress levels and the common shape parameter. Using the approach, Bayes point estimates as well as probability statements for use-stress (and accelerated) life parameters may be inferred from a host of testing scenarios. The inference procedure accommodates both the interval data sampling strategy and type I censored sampling strategy for the collection of ALT test data. The inference procedure uses the well-known MCMC (Markov Chain Monte Carlo) methods to derive posterior approximations. The approach is illustrated with an example

  11. RF pulse compression in the NLC test accelerator at SLAC

    International Nuclear Information System (INIS)

    Lavine, T.L.

    1995-01-01

    At the Stanford Linear Accelerator Center (SLAC), we are designing a Next Linear Collider (NLC) with linacs powered by X-band klystrons with rf pulse compression. The design of the linac rf system is based on X-band prototypes which have been tested at high power, and on a systems-integration test---the Next Linear Collider Test Accelerator (NLCTA)---which is currently under construction at SLAC. This paper discusses some of the systems implications of rf pulse compression, and the use of pulse compression in the NLCTA, both for peak power multiplication and for controlling, by rf phase modulation, intra-pulse variations in the linac beam energy. copyright 1995 American Institute of Physics

  12. An Integration Testing Facility for the CERN Accelerator Controls System

    CERN Document Server

    Stapley, N; Bau, J C; Deghaye, S; Dehavay, C; Sliwinski, W; Sobczak, M

    2009-01-01

    A major effort has been invested in the design, development, and deployment of the LHC Control System. This large control system is made up of a set of core components and dependencies, which although tested individually, are often not able to be tested together on a system capable of representing the complete control system environment, including hardware. Furthermore this control system is being adapted and applied to CERN's whole accelerator complex, and in particular for the forthcoming renovation of the PS accelerators. To ensure quality is maintained as the system evolves, and toimprove defect prevention, the Controls Group launched a project to provide a dedicated facility for continuous, automated, integration testing of its core components to incorporate into its production process. We describe the project, initial lessons from its application, status, and future directions.

  13. Reliability of Maximal Strength Testing in Novice Weightlifters

    Science.gov (United States)

    Loehr, James A.; Lee, Stuart M. C.; Feiveson, Alan H.; Ploutz-Snyder, Lori L.

    2009-01-01

    The one repetition maximum (1RM) is a criterion measure of muscle strength. However, the reliability of 1RM testing in novice subjects has received little attention. Understanding this information is crucial to accurately interpret changes in muscle strength. To evaluate the test-retest reliability of a squat (SQ), heel raise (HR), and deadlift (DL) 1RM in novice subjects. Twenty healthy males (31 plus or minus 5 y, 179.1 plus or minus 6.1 cm, 81.4 plus or minus 10.6 kg) with no weight training experience in the previous six months participated in four 1RM testing sessions, with each session separated by 5-7 days. SQ and HR 1RM were conducted using a smith machine; DL 1RM was assessed using free weights. Session 1 was considered a familiarization and was not included in the statistical analyses. Repeated measures analysis of variance with Tukey fs post-hoc tests were used to detect between-session differences in 1RM (p.0.05). Test-retest reliability was evaluated by intraclass correlation coefficients (ICC). During Session 2, the SQ and DL 1RM (SQ: 90.2 }4.3, DL: 75.9 }3.3 kg) were less than Session 3 (SQ: 95.3 }4.1, DL: 81.5 plus or minus 3.5 kg) and Session 4 (SQ: 96.6 }4.0, DL: 82.4 }3.9 kg), but there were no differences between Session 3 and Session 4. HR 1RM measured during Session 2 (150.1 }3.7 kg) and Session 3 (152.5 }3.9 kg) were not different from one another, but both were less than Session 4 (157.5 }3.8 kg). The reliability (ICC) of 1RM measures for Sessions 2-4 were 0.88, 0.83, and 0.87, for SQ, HR, and DL, respectively. When considering only Sessions 3 and 4, the reliability was 0.93, 0.91, and 0.86 for SQ, HR, and DL, respectively. One familiarization session and 2 test sessions (for SQ and DL) were required to obtain excellent reliability (ICC greater than or equal to 0.90) in 1RM values with novice subjects. We were unable to attain this level of reliability following 3 HR testing sessions therefore additional sessions may be required to obtain an

  14. 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.

  15. The reliability of sickling and solubility tests and peripheral blood ...

    African Journals Online (AJOL)

    The reliability of sickling and solubility tests and peripheral blood film method for sickle cell disease screening at district health centers in Uganda. ... Les 200 prélèvements des enfants ages de 6 mois à 5 ans ont été analysés de façon indépendante en utilisant la méthode des analyses d'hématies falciformes, la solubilité et ...

  16. Reliability, Validity and Factor Structure of Drug Abuse Screening Test

    OpenAIRE

    Sayed Hadi Sayed Alitabar; Mojtaba Habibi; Maryam Falahatpisheh; Musa Arvin

    2016-01-01

    Background and Objective: According to the increasing of substance use in the country, more researches about this phenomenon are necessary. This Study Investigates the Validity, Reliability and Confirmatory Factor Structure of the Drug Abuse Screening test (DAST). Materials and Methods: The Sample Consisted of 381 Patients (143 Women and 238 Men) with a Multi-Stage Cluster Sampling of Areas 2, 6 and 12 of Tehran Were Selected from Each Region, 6 Randomly Selected Drug Rehabilitation Center. T...

  17. Final report : testing and evaluation for solar hot water reliability.

    Energy Technology Data Exchange (ETDEWEB)

    Caudell, Thomas P. (University of New Mexico, Albuquerque, NM); He, Hongbo (University of New Mexico, Albuquerque, NM); Menicucci, David F. (Building Specialists, Inc., Albuquerque, NM); Mammoli, Andrea A. (University of New Mexico, Albuquerque, NM); Burch, Jay (National Renewable Energy Laboratory, Golden CO)

    2011-07-01

    Solar hot water (SHW) systems are being installed by the thousands. Tax credits and utility rebate programs are spurring this burgeoning market. However, the reliability of these systems is virtually unknown. Recent work by Sandia National Laboratories (SNL) has shown that few data exist to quantify the mean time to failure of these systems. However, there is keen interest in developing new techniques to measure SHW reliability, particularly among utilities that use ratepayer money to pay the rebates. This document reports on an effort to develop and test new, simplified techniques to directly measure the state of health of fielded SHW systems. One approach was developed by the National Renewable Energy Laboratory (NREL) and is based on the idea that the performance of the solar storage tank can reliably indicate the operational status of the SHW systems. Another approach, developed by the University of New Mexico (UNM), uses adaptive resonance theory, a type of neural network, to detect and predict failures. This method uses the same sensors that are normally used to control the SHW system. The NREL method uses two additional temperature sensors on the solar tank. The theories, development, application, and testing of both methods are described in the report. Testing was performed on the SHW Reliability Testbed at UNM, a highly instrumented SHW system developed jointly by SNL and UNM. The two methods were tested against a number of simulated failures. The results show that both methods show promise for inclusion in conventional SHW controllers, giving them advanced capability in detecting and predicting component failures.

  18. The Reliability of a Functional Agility Test for Water Polo

    Directory of Open Access Journals (Sweden)

    Tucher Guilherme

    2014-07-01

    Full Text Available Few functional agility tests for water polo take into consideration its specific characteristics. The preliminary objective of this study was to evaluate the reliability of an agility test for water polo players. Fifteen players (16.3 ± 1.8 years old with a minimum of two years of competitive experience were evaluated. A Functional Test for Agility Performance (FTAP was designed to represent the context of this sport. Several trials were performed to familiarize the athlete with the movement. Two experienced coaches measured three repetitions of the FTAP. Descriptive statistics, repeated measures analysis of variance (ANOVA, 95% limit of agreement (LOA, intraclass correlation coefficient (ICC and standard error of measurements (SEM were used for data analysis. It was considered that certain criteria of reliability measures were met. There was no significant difference between the repetitions, which may be explained by an effect of the evaluator, the ability of the players or fatigue (p > 0.05. The ICC average from evaluators was high (0.88. The SEM varied between 0.13 s and 0.49 s. The CV average considering each individual was near 6-7%. These values depended on the condition of measurement. As the FTAP contains some characteristics that create a degree of unpredictability, the same athlete may reach different performance results, increasing variability. An adjustment in the sample, familiarization and careful selection of subjects help to improve this situation and enhance the reliability of the indicators.

  19. Proposal for an Accelerator R&D User Facility at Fermilab's Advanced Superconducting Test Accelerator (ASTA)

    Energy Technology Data Exchange (ETDEWEB)

    Church, M. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Edwards, H. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Harms, E. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Henderson, S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Holmes, S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lumpkin, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kephart, R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Levedev, V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Leibfritz, J. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Nagaitsev, S. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Piot, P. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Northern Illinois Univ., DeKalb, IL (United States); Prokop, C. [Northern Illinois Univ., DeKalb, IL (United States); Shiltsev, V. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Sun, Y. E. [Argonne National Lab. (ANL), Argonne, IL (United States); Valishev, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-10-01

    Fermilab is the nation’s particle physics laboratory, supported by the DOE Office of High Energy Physics (OHEP). Fermilab is a world leader in accelerators, with a demonstrated track-record— spanning four decades—of excellence in accelerator science and technology. We describe the significant opportunity to complete, in a highly leveraged manner, a unique accelerator research facility that supports the broad strategic goals in accelerator science and technology within the OHEP. While the US accelerator-based HEP program is oriented toward the Intensity Frontier, which requires modern superconducting linear accelerators and advanced highintensity storage rings, there are no accelerator test facilities that support the accelerator science of the Intensity Frontier. Further, nearly all proposed future accelerators for Discovery Science will rely on superconducting radiofrequency (SRF) acceleration, yet there are no dedicated test facilities to study SRF capabilities for beam acceleration and manipulation in prototypic conditions. Finally, there are a wide range of experiments and research programs beyond particle physics that require the unique beam parameters that will only be available at Fermilab’s Advanced Superconducting Test Accelerator (ASTA). To address these needs we submit this proposal for an Accelerator R&D User Facility at ASTA. The ASTA program is based on the capability provided by an SRF linac (which provides electron beams from 50 MeV to nearly 1 GeV) and a small storage ring (with the ability to store either electrons or protons) to enable a broad range of beam-based experiments to study fundamental limitations to beam intensity and to develop transformative approaches to particle-beam generation, acceleration and manipulation which cannot be done elsewhere. It will also establish a unique resource for R&D towards Energy Frontier facilities and a test-bed for SRF accelerators and high brightness beam applications in support of the OHEP

  20. BFROST: binary features from robust orientation segment tests accelerated on the GPU

    CSIR Research Space (South Africa)

    Cronje, J

    2011-11-01

    Full Text Available purpose parallel algo- rithms. The CUDA (Compute Unified Device Architecture) [1] framework from NVidia provides a programmable interface for GPUs. FAST (Features from Accelerated Segment Tests) [2], [3] is one of the fastest and most reliable corner... runs. Our detector detects slightly more keypoints because the decision tree of FAST does not perform a complete segment test. Timing comparisons were performed on a NVidia GeForce GTX 460 for our GPU implementation and on a Intel Core i7 2.67 GHz...

  1. Beam Extraction for 1-MV Electrostatic Accelerator at the 300 kV Test Stand

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sae-Hoon; Kim, Yu-Seok [Dongguk University, Seoul (Korea, Republic of); Kwon, Hyeok-Jung; Cho, Yong-Sub [KOMAC, Gyeongju (Korea, Republic of)

    2015-05-15

    The Korea Multipurpose Accelerator Complex (KOMAC) has been developing a 300-kV test stand for a 1-MV electrostatic accelerator ion source. The ion source in the high-pressure vessel is required to have a high reliability. The test stand has been proposed and developed to confirm the stable operating conditions of the ion source. The ion source will be tested at the test stand to verify the long-time operating conditions. The test stand comprises a 300-kV high-voltage terminal, a battery for the ion-source power, a 60-Hz inverter, 200-MHz RF power, a 5-kV extraction power supply, a 300-kV accelerating tube, and a vacuum system. A beam extraction experiment for the test stand was performed, and the beam current was measured using a faraday cup in the chamber. A beam extraction results for the RF ion source will be presented. Beam extraction from the RF ion source of the test stand is verified by measuring the beam current with a faraday cup in the chamber. Thus far NI Labview, PLC and faraday cup have been used to measure the beam current. The OPC server is useful for monitoring the PLC values. The average beam current of (a), (b) and (c) shown in figure 2 are 110.241µA, 105.8597µA and 103.5278µA respectively.

  2. Proving test on the reliability for nuclear valves

    International Nuclear Information System (INIS)

    Kajiyama, Yasuo; Tashiro, Hisao; Uga, Takeo; Maeda, Shunichi.

    1986-01-01

    Since valves are the most common components, they could be the most frequent causes of troubles in nuclear power plants. This proving test, therefore, has an important meaning to examine and verify the reliability of various valves under simulating conditions of abnormal and transient operations of the nuclear power plant. The test was performed mainly for the various types and pressure ratings of valves which were used in the primary and secondary systems in BWR and PWR nuclear power plants and which had major operating or safety related functions in those nuclear power plants. The results of the proving test, confirmed for more than four years, showed relatively favourable performance of the tested valves. It is concluded that performances of valves including operability, seat sealing and structural integrity were proved under the thermal cycling, vibration and pipe reaction load conditions. Operating functions during and after accident such as loss of coolant accident were satisfactory. From these results, it was considered that the purpose of this proving test was satisfactorily fulfilled. Several data accumulated by the test would be useful to get better reliability if it was evaluated with the actually experienced data of valves in the nuclear power plants. (Nogami, K.)

  3. Reliability of a Computerized Neurocognitive Test in Baseline Concussion Testing of High School Athletes.

    Science.gov (United States)

    MacDonald, James; Duerson, Drew

    2015-07-01

    Baseline assessments using computerized neurocognitive tests are frequently used in the management of sport-related concussions. Such testing is often done on an annual basis in a community setting. Reliability is a fundamental test characteristic that should be established for such tests. Our study examined the test-retest reliability of a computerized neurocognitive test in high school athletes over 1 year. Repeated measures design. Two American high schools. High school athletes (N = 117) participating in American football or soccer during the 2011-2012 and 2012-2013 academic years. All study participants completed 2 baseline computerized neurocognitive tests taken 1 year apart at their respective schools. The test measures performance on 4 cognitive tasks: identification speed (Attention), detection speed (Processing Speed), one card learning accuracy (Learning), and one back speed (Working Memory). Reliability was assessed by measuring the intraclass correlation coefficient (ICC) between the repeated measures of the 4 cognitive tasks. Pearson and Spearman correlation coefficients were calculated as a secondary outcome measure. The measure for identification speed performed best (ICC = 0.672; 95% confidence interval, 0.559-0.760) and the measure for one card learning accuracy performed worst (ICC = 0.401; 95% confidence interval, 0.237-0.542). All tests had marginal or low reliability. In a population of high school athletes, computerized neurocognitive testing performed in a community setting demonstrated low to marginal test-retest reliability on baseline assessments 1 year apart. Further investigation should focus on (1) improving the reliability of individual tasks tested, (2) controlling for external factors that might affect test performance, and (3) identifying the ideal time interval to repeat baseline testing in high school athletes. Computerized neurocognitive tests are used frequently in high school athletes, often within a model of baseline testing

  4. Diagnostic reliability of MMPI-2 computer-based test interpretations.

    Science.gov (United States)

    Pant, Hina; McCabe, Brian J; Deskovitz, Mark A; Weed, Nathan C; Williams, John E

    2014-09-01

    Reflecting the common use of the MMPI-2 to provide diagnostic considerations, computer-based test interpretations (CBTIs) also typically offer diagnostic suggestions. However, these diagnostic suggestions can sometimes be shown to vary widely across different CBTI programs even for identical MMPI-2 profiles. The present study evaluated the diagnostic reliability of 6 commercially available CBTIs using a 20-item Q-sort task developed for this study. Four raters each sorted diagnostic classifications based on these 6 CBTI reports for 20 MMPI-2 profiles. Two questions were addressed. First, do users of CBTIs understand the diagnostic information contained within the reports similarly? Overall, diagnostic sorts of the CBTIs showed moderate inter-interpreter diagnostic reliability (mean r = .56), with sorts for the 1/2/3 profile showing the highest inter-interpreter diagnostic reliability (mean r = .67). Second, do different CBTIs programs vary with respect to diagnostic suggestions? It was found that diagnostic sorts of the CBTIs had a mean inter-CBTI diagnostic reliability of r = .56, indicating moderate but not strong agreement across CBTIs in terms of diagnostic suggestions. The strongest inter-CBTI diagnostic agreement was found for sorts of the 1/2/3 profile CBTIs (mean r = .71). Limitations and future directions are discussed. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  5. Preloading To Accelerate Slow-Crack-Growth Testing

    Science.gov (United States)

    Gyekenyesi, John P.; Choi, Sung R.; Pawlik, Ralph J.

    2004-01-01

    An accelerated-testing methodology has been developed for measuring the slow-crack-growth (SCG) behavior of brittle materials. Like the prior methodology, the accelerated-testing methodology involves dynamic fatigue ( constant stress-rate) testing, in which a load or a displacement is applied to a specimen at a constant rate. SCG parameters or life prediction parameters needed for designing components made of the same material as that of the specimen are calculated from the relationship between (1) the strength of the material as measured in the test and (2) the applied stress rate used in the test. Despite its simplicity and convenience, dynamic fatigue testing as practiced heretofore has one major drawback: it is extremely time-consuming, especially at low stress rates. The present accelerated methodology reduces the time needed to test a specimen at a given rate of applied load, stress, or displacement. Instead of starting the test from zero applied load or displacement as in the prior methodology, one preloads the specimen and increases the applied load at the specified rate (see Figure 1). One might expect the preload to alter the results of the test and indeed it does, but fortunately, it is possible to account for the effect of the preload in interpreting the results. The accounting is done by calculating the normalized strength (defined as the strength in the presence of preload the strength in the absence of preload) as a function of (1) the preloading factor (defined as the preload stress the strength in the absence of preload) and (2) a SCG parameter, denoted n, that is used in a power-law crack-speed formulation. Figure 2 presents numerical results from this theoretical calculation.

  6. Reliability demonstration test for load-sharing systems with exponential and Weibull components.

    Directory of Open Access Journals (Sweden)

    Jianyu Xu

    Full Text Available Conducting a Reliability Demonstration Test (RDT is a crucial step in production. Products are tested under certain schemes to demonstrate whether their reliability indices reach pre-specified thresholds. Test schemes for RDT have been studied in different situations, e.g., lifetime testing, degradation testing and accelerated testing. Systems designed with several structures are also investigated in many RDT plans. Despite the availability of a range of test plans for different systems, RDT planning for load-sharing systems hasn't yet received the attention it deserves. In this paper, we propose a demonstration method for two specific types of load-sharing systems with components subject to two distributions: exponential and Weibull. Based on the assumptions and interpretations made in several previous works on such load-sharing systems, we set the mean time to failure (MTTF of the total system as the demonstration target. We represent the MTTF as a summation of mean time between successive component failures. Next, we introduce generalized test statistics for both the underlying distributions. Finally, RDT plans for the two types of systems are established on the basis of these test statistics.

  7. Estimation for a Weibull accelerated life testing model

    International Nuclear Information System (INIS)

    Glaser, R.E.

    1984-01-01

    It is sometimes reasonable to assume that the lifetime distribution of an item belongs to a certain parametric family, and that actual parameter values depend upon the testing environment of the item. In the two-parameter Weibull family setting, suppose both the shape and scale parameters are expressible as functions of the testing environment. For various models of functional dependency on environment, maximum likelihood methods are used to estimate characteristics of interest at specified environmental levels. The methodology presented handles exact, censored, and grouped data. A detailed accelerated life testing analysis of stress-rupture data for Kevlar/epoxy composites is given. 10 references, 1 figure, 2 tables

  8. NDT Reliability - Final Report. Reliability in non-destructive testing (NDT) of the canister components

    Energy Technology Data Exchange (ETDEWEB)

    Pavlovic, Mato; Takahashi, Kazunori; Mueller, Christina; Boehm, Rainer (BAM, Federal Inst. for Materials Research and Testing, Berlin (Germany)); Ronneteg, Ulf (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden))

    2008-12-15

    This report describes the methodology of the reliability investigation performed on the ultrasonic phased array NDT system, developed by SKB in collaboration with Posiva, for inspection of the canisters for permanent storage of nuclear spent fuel. The canister is composed of a cast iron insert surrounded by a copper shell. The shell is composed of the tube and the lid/base which are welded to the tube after the fuel has been place, in the tube. The manufacturing process of the canister parts and the welding process are described. Possible defects, which might arise in the canister components during the manufacturing or in the weld during the welding, are identified. The number of real defects in manufactured components have been limited. Therefore the reliability of the NDT system has been determined using a number of test objects with artificial defects. The reliability analysis is based on the signal response analysis. The conventional signal response analysis is adopted and further developed before applied on the modern ultrasonic phased-array NDT system. The concept of multi-parameter a, where the response of the NDT system is dependent on more than just one parameter, is introduced. The weakness of use of the peak signal response in the analysis is demonstrated and integration of the amplitudes in the C-scan is proposed as an alternative. The calculation of the volume POD, when the part is inspected with more configurations, is also presented. The reliability analysis is supported by the ultrasonic simulation based on the point source synthesis method

  9. European accelerator facilities for single event effects testing

    Energy Technology Data Exchange (ETDEWEB)

    Adams, L; Nickson, R; Harboe-Sorensen, R [ESA-ESTEC, Noordwijk (Netherlands); Hajdas, W; Berger, G

    1997-03-01

    Single event effects are an important hazard to spacecraft and payloads. The advances in component technology, with shrinking dimensions and increasing complexity will give even more importance to single event effects in the future. The ground test facilities are complex and expensive and the complexities of installing a facility are compounded by the requirement that maximum control is to be exercised by users largely unfamiliar with accelerator technology. The PIF and the HIF are the result of experience gained in the field of single event effects testing and represent a unique collaboration between space technology and accelerator experts. Both facilities form an essential part of the European infrastructure supporting space projects. (J.P.N.)

  10. Gearbox Reliability Collaborative Phase 3 Gearbox 3 Test Report

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Jonathan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Wallen, Robb [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-02-24

    Many gearboxes in wind turbines do not achieve their expected design life; they do, however, commonly meet or exceed the design criteria specified in current standards in the gear, bearing, and wind turbine industry as well as third-party certification criteria. The cost of gearbox replacements and rebuilds, as well as the downtime associated with these failures, increases the cost of wind energy. In 2007, the U.S. Department of Energy established the National Renewable Energy Laboratory (NREL) Gearbox Reliability Collaborative (GRC). Its goals are to understand the root causes of premature gearbox failures and to improve their reliability. The GRC is examining a hypothesis that the gap between design-estimated and actual wind turbine gearbox reliability is caused by underestimation of loads, inaccurate design tools, the absence of critical elements in the design process, or insufficient testing. This report describes the recently completed tests of GRC Gearbox 3 in the National Wind Technology Center dynamometer and documents any modifications to the original test plan. In this manner, it serves as a guide for interpreting the publicly released data sets with brief analyses to illustrate the data. The primary test objective was to measure the planetary load-sharing characteristics in the same conditions as the original GRC gearbox design. If the measured load-sharing characteristics are close to the design model, the projected improvement in planetary section fatigue life and the efficacy of preloaded TRBs in mitigating the planetary bearing fatigue failure mode will have been demonstrated. Detailed analysis of that test objective will be presented in subsequent publications.

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

    Science.gov (United States)

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

    2014-11-01

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

  12. Accelerated life testing design using geometric process for pareto distribution

    OpenAIRE

    Mustafa Kamal; Shazia Zarrin; Arif Ul Islam

    2013-01-01

    In this paper the geometric process is used for the analysis of accelerated life testing under constant stress for Pareto Distribution. Assuming that the lifetimes under increasing stress levels form a geometric process, estimates of the parameters are obtained by using the maximum likelihood method for complete data. In addition, asymptotic interval estimates of the parameters of the distribution using Fisher information matrix are also obtained. The statistical properties of the parameters ...

  13. Automatically generated acceptance test: A software reliability experiment

    Science.gov (United States)

    Protzel, Peter W.

    1988-01-01

    This study presents results of a software reliability experiment investigating the feasibility of a new error detection method. The method can be used as an acceptance test and is solely based on empirical data about the behavior of internal states of a program. The experimental design uses the existing environment of a multi-version experiment previously conducted at the NASA Langley Research Center, in which the launch interceptor problem is used as a model. This allows the controlled experimental investigation of versions with well-known single and multiple faults, and the availability of an oracle permits the determination of the error detection performance of the test. Fault interaction phenomena are observed that have an amplifying effect on the number of error occurrences. Preliminary results indicate that all faults examined so far are detected by the acceptance test. This shows promise for further investigations, and for the employment of this test method on other applications.

  14. Reliability and Validity of the Inline Skating Skill Test

    Science.gov (United States)

    Radman, Ivan; Ruzic, Lana; Padovan, Viktoria; Cigrovski, Vjekoslav; Podnar, Hrvoje

    2016-01-01

    This study aimed to examine the reliability and validity of the inline skating skill test. Based on previous skating experience forty-two skaters (26 female and 16 male) were randomized into two groups (competitive level vs. recreational level). They performed the test four times, with a recovery time of 45 minutes between sessions. Prior to testing, the participants rated their skating skill using a scale from 1 to 10. The protocol included performance time measurement through a course, combining different skating techniques. Trivial changes in performance time between the repeated sessions were determined in both competitive females/males and recreational females/males (-1.7% [95% CI: -5.8–2.6%] – 2.2% [95% CI: 0.0–4.5%]). In all four subgroups, the skill test had a low mean within-individual variation (1.6% [95% CI: 1.2–2.4%] – 2.7% [95% CI: 2.1–4.0%]) and high mean inter-session correlation (ICC = 0.97 [95% CI: 0.92–0.99] – 0.99 [95% CI: 0.98–1.00]). The comparison of detected typical errors and smallest worthwhile changes (calculated as standard deviations × 0.2) revealed that the skill test was able to track changes in skaters’ performances. Competitive-level skaters needed shorter time (24.4–26.4%, all p skating skills in amateur competitive and recreational level skaters. Further studies are needed to evaluate the reproducibility of this skill test in different populations including elite inline skaters. Key points Study evaluated the reliability and construct validity of a newly developed inline skating skill test. Evaluated test is a first protocol designed to assess specific inline skating skill. Two groups of amateur skaters with different skating proficiency repeated the skill test in four separate occasions. The results suggest that evaluated test is reliable and valid to evaluate inline skating skill in amateur skaters. PMID:27803616

  15. Accelerated Creep Testing of High Strength Aramid Webbing

    Science.gov (United States)

    Jones, Thomas C.; Doggett, William R.; Stnfield, Clarence E.; Valverde, Omar

    2012-01-01

    A series of preliminary accelerated creep tests were performed on four variants of 12K and 24K lbf rated Vectran webbing to help develop an accelerated creep test methodology and analysis capability for high strength aramid webbings. The variants included pristine, aged, folded and stitched samples. This class of webbings is used in the restraint layer of habitable, inflatable space structures, for which the lifetime properties are currently not well characterized. The Stepped Isothermal Method was used to accelerate the creep life of the webbings and a novel stereo photogrammetry system was used to measure the full-field strains. A custom MATLAB code is described, and used to reduce the strain data to produce master creep curves for the test samples. Initial results show good correlation between replicates; however, it is clear that a larger number of samples are needed to build confidence in the consistency of the results. It is noted that local fiber breaks affect the creep response in a similar manner to increasing the load, thus raising the creep rate and reducing the time to creep failure. The stitched webbings produced the highest variance between replicates, due to the combination of higher local stresses and thread-on-fiber damage. Large variability in the strength of the webbings is also shown to have an impact on the range of predicted creep life.

  16. Development of an accelerated test for Internal Sulfate Attack study

    Directory of Open Access Journals (Sweden)

    Khelil Nacim

    2014-04-01

    Full Text Available Internal Sulfate Attack (ISA is a pathology that occurs under certain conditions in concrete having undergone heating above 70 °C at early age (through heating in pre-casting industry or due to hydration in large concrete parts. This reaction deemed very slow, numerous methods to speed up reactions leading to delayed ettringite formation have been developed. These methods are all based on the material damage. Another type of test is currently under development. It is based on rehabilitation techniques such as electrochemical chloride extraction (ECE in order to accelerate the leaching of alkalis that could be one of the triggers of the pathology. The study presented in this paper focused on concrete specimens prepared from cement (CEM I 52.5 N enriched with Na2SO4. These concretes have undergone a heat treatment typical of those used in precast plants (up to 24 hours with a maximum temperature of 80 °C. Various paths were explored for the development of the accelerated test. The first results showed that it was necessary to use a removable titanium anode ruthenium anode instead of stainless steel embedded in the concrete. Then tests with de-ionized water as the solute to the cathode did not accelerate the onset of expansions. The experiment has been modified and potassium carbonate was added to the solution. This modification didn’t show any significant improvement, and other experiments are being carried out to explain this result.

  17. On selection of optimal stochastic model for accelerated life testing

    International Nuclear Information System (INIS)

    Volf, P.; Timková, J.

    2014-01-01

    This paper deals with the problem of proper lifetime model selection in the context of statistical reliability analysis. Namely, we consider regression models describing the dependence of failure intensities on a covariate, for instance, a stressor. Testing the model fit is standardly based on the so-called martingale residuals. Their analysis has already been studied by many authors. Nevertheless, the Bayes approach to the problem, in spite of its advantages, is just developing. We shall present the Bayes procedure of estimation in several semi-parametric regression models of failure intensity. Then, our main concern is the Bayes construction of residual processes and goodness-of-fit tests based on them. The method is illustrated with both artificial and real-data examples. - Highlights: • Statistical survival and reliability analysis and Bayes approach. • Bayes semi-parametric regression modeling in Cox's and AFT models. • Bayes version of martingale residuals and goodness-of-fit test

  18. Reliability of psychophysiological responses across multiple motion sickness stimulation tests

    Science.gov (United States)

    Stout, C. S.; Toscano, W. B.; Cowings, P. S.

    1995-01-01

    Although there is general agreement that a high degree of variability exists between subjects in their autonomic nervous system responses to motion sickness stimulation, very little evidence exists that examines the reproducibility of autonomic responses within subjects during motion sickness stimulation. Our objectives were to examine the reliability of autonomic responses and symptom levels across five testing occasions using the (1) final minute of testing, (2) change in autonomic response and the change in symptom level, and (3) strength of the relationship between the change in symptom level and the change in autonomic responses across the entire motion sickness test. The results indicate that, based on the final minute of testing, the autonomic responses of heart rate, blood volume pulse, and respiration rate are moderately stable across multiple tests. Changes in heart rate, blood volume pulse, respiration rate, and symptoms throughout the test duration are less stable across the tests. Finally, autonomic responses and symptom levels are significantly related across the entire motion sickness test.

  19. Beam Profile Measurement of 300 kV Ion Source Test Stand for 1 MV Electrostatic Accelerator

    International Nuclear Information System (INIS)

    Park, Sae-Hoon; Kim, Yu-Seok; Kim, Dae-Il; Kwon, Hyeok-Jung; Cho, Yong-Sub

    2015-01-01

    In this paper, RF ion source, test stand of the ion source and its test results are presented. Beam profile was measured at the downstream from the accelerating tube and at the beam dump by using BPM and wire scanner. The RF ion source of the test stand is verified by measuring the total beam current with a faraday cup in the chamber. The KOMAC (KOrea Multi-purpose Accelerator Complex) has been developing a 300 kV ion source test stand for a 1 MV electrostatic accelerator. An ion source and accelerating tube will be installed in a high pressure vessel. The ion source in a high pressure vessel requires high reliability. To confirm the stable operation of the ion source, a test stand was proposed and developed. The ion source will be tested at the test stand to verify its long-term operation conditions. The test stand consists of a 300 kV high voltage terminal, a battery for the ion source power, a 60 Hz inverter, a 200 MHz RF power, a 5 kV extraction power supply, a 300 kV accelerating tube, and a vacuum system. The beam profile monitor was installed at the downstream from the accelerating tube. Wire scanner and faraday-cup was installed at the end of the chamber

  20. Beam Profile Measurement of 300 kV Ion Source Test Stand for 1 MV Electrostatic Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sae-Hoon; Kim, Yu-Seok [Dongguk University, Gyeonju (Korea, Republic of); Kim, Dae-Il; Kwon, Hyeok-Jung; Cho, Yong-Sub [Korea Multipurpose Accelerator Complex, Gyeongju (Korea, Republic of)

    2015-10-15

    In this paper, RF ion source, test stand of the ion source and its test results are presented. Beam profile was measured at the downstream from the accelerating tube and at the beam dump by using BPM and wire scanner. The RF ion source of the test stand is verified by measuring the total beam current with a faraday cup in the chamber. The KOMAC (KOrea Multi-purpose Accelerator Complex) has been developing a 300 kV ion source test stand for a 1 MV electrostatic accelerator. An ion source and accelerating tube will be installed in a high pressure vessel. The ion source in a high pressure vessel requires high reliability. To confirm the stable operation of the ion source, a test stand was proposed and developed. The ion source will be tested at the test stand to verify its long-term operation conditions. The test stand consists of a 300 kV high voltage terminal, a battery for the ion source power, a 60 Hz inverter, a 200 MHz RF power, a 5 kV extraction power supply, a 300 kV accelerating tube, and a vacuum system. The beam profile monitor was installed at the downstream from the accelerating tube. Wire scanner and faraday-cup was installed at the end of the chamber.

  1. Reliability of isometric subtalar pronator and supinator strength testing.

    Science.gov (United States)

    Hagen, Marco; Lahner, Matthias; Winhuysen, Martin; Maiwald, Christian

    2015-01-01

    Due to the specific anatomy of the subtalar joint with its oblique axis, isometric pronator and supinator strength is not well documented. The purpose of this study was to determine intra- and between-session reliability of pronator and supinator strength and lower leg muscle activity measurements during maximum voluntary isometric contractions (MVIC). Pronator and supinator peak torques (PT), with and without supplementary visual muscle strength biofeedback (FB), and muscular activities of peroneus longus (PL) and tibialis anterior (TA) were assessed twice 3 days apart by the same examiner in 21 healthy young male adults (mean age: 27.6 years; SD = 3.9). Limits of agreement (LoA) and minimum detectable change (MDC) were evaluated. By applying FB, reliability of both pronator and supinator PT was improved: LoA were reduced from 32% to 26% and from 20% to 18% and MDC from 20% to 15% and from 16% to 12% in supinator and pronator PT, respectively. Learning effects in pronator and supinator PT (p isometric subtalar pronator and supinator strength testing is reliable in healthy subjects. LoA of 18% and 26% have to be exceeded for pronator and supinator PT, respectively, to detect relevant effects in repeated measures.

  2. Reliability, Validity and Factor Structure of Drug Abuse Screening Test

    Directory of Open Access Journals (Sweden)

    Sayed Hadi Sayed Alitabar

    2016-05-01

    Full Text Available Background and Objective: According to the increasing of substance use in the country, more researches about this phenomenon are necessary. This Study Investigates the Validity, Reliability and Confirmatory Factor Structure of the Drug Abuse Screening test (DAST. Materials and Methods: The Sample Consisted of 381 Patients (143 Women and 238 Men with a Multi-Stage Cluster Sampling of Areas 2, 6 and 12 of Tehran Were Selected from Each Region, 6 Randomly Selected Drug Rehabilitation Center. The DAST Was Used as Instrument. Divergent & Convergent Validity of this Scale Was Assessed with Problems Assessment for Substance Using Psychiatric Patients (PASUPP and Relapse Prediction Scale (RPS.Results: The DAST after the First Time Factor Structure of Using Confirmatory Factor Analysis Was Confirmed. The DAST Had a Good Internal Consistency (Cranach’s Alpha, and the Reliability of the Test Within a Week, 0.9, 0.8. Also this Scale Had a Positive Correlation with Problems Assessment for Substance Using Psychiatric Patients and Relapse Prediction Scale (P<0.01.Conclusion: The Overall Results Showed that the Drug Abuse Screening Test in Iranian Society Is Valid. It Can Be Said that Self-Report Scale Tool Is Useful for Research Purposes and Addiction.

  3. Forward lunge as a functional performance test in ACL deficient subjects: test-retest reliability

    DEFF Research Database (Denmark)

    Alkjaer, Tine; Henriksen, Marius; Dyhre-Poulsen, Poul

    2009-01-01

    The forward lunge movement may be used as a functional performance test of anterior cruciate ligament (ACL) deficient and reconstructed subjects. The purposes were 1) to determine the test-retest reliability of a forward lunge in healthy subjects and 2) to determine the required numbers...... of repetitions necessary to yield satisfactory reliability. Nineteen healthy subjects performed four trials of a forward lunge on two different days. The movement time, impulses of the ground reaction forces (IFz, IFy), knee joint kinematics and dynamics during the forward lunge were calculated. The relative...... reliability was determined by calculation of Intraclass Correlation Coefficients (ICC). The IFz, IFy and the positive work of the knee extensors showed excellent reliability (ICC >0.75). All other variables demonstrated acceptable reliability (0.4>ICCreliability increased when more than...

  4. Test rig overview for validation and reliability testing of shutdown system software

    International Nuclear Information System (INIS)

    Zhao, M.; McDonald, A.; Dick, P.

    2007-01-01

    The test rig for Validation and Reliability Testing of shutdown system software has been upgraded from the AECL Windows-based test rig previously used for CANDU6 stations. It includes a Virtual Trip Computer, which is a software simulation of the functional specification of the trip computer, and a real-time trip computer simulator in a separate chassis, which is used during the preparation of trip computer test cases before the actual trip computers are available. This allows preparation work for Validation and Reliability Testing to be performed in advance of delivery of actual trip computers to maintain a project schedule. (author)

  5. INTERSESSION RELIABILITY OF UPPER EXTREMITY ISOKINETIC PUSH-PULL TESTING.

    Science.gov (United States)

    Riemann, Bryan L; Davis, Sarah E; Huet, Kevin; Davies, George J

    2016-02-01

    Based on the frequency pushing and pulling patterns are used in functional activities, there is a need to establish an objective method of quantifying the muscle performance characteristics associated with these motions, particularly during the later stages of rehabilitation as criteria for discharge. While isokinetic assessment offers an approach to quantifying muscle performance, little is known about closed kinetic chain (CKC) isokinetic testing of the upper extremity (UE). To determine the intersession reliability of isokinetic upper extremity measurement of pushing and pulling peak force and average power at slow (0.24 m/s), medium (0.43 m/s) and fast (0.61 m/s) velocities in healthy young adults. The secondary purpose was to compare pushing and pulling peak force (PF) and average power (AP) between the upper extremity limbs (dominant, non-dominant) across the three velocities. Twenty-four physically active men and women completed a test-retest (>96 hours) protocol in order to establish isokinetic UE CKC reliability of PF and AP during five maximal push and pull repetitions at three velocities. Both limb and speed orders were randomized between subjects. High test-retest relative reliability using intraclass correlation coefficients (ICC2, 1) were revealed for PF (.91-.97) and AP (.85-.95) across velocities, limbs and directions. PF typical error (% coefficient of variation) ranged from 6.1% to 11.3% while AP ranged from 9.9% to 26.7%. PF decreased significantly (p pushing were significantly greater than pulling at all velocities, however the push-pull differences in PF became less as velocity increased. There were no significant differences identified between the dominant and nondominant limbs. Isokinetically derived UE CKC push-pull PF and AP are reliable measures. The lack of limb differences in healthy normal participants suggests that clinicians can consider bilateral comparisons when interpreting test performance. The increase in pushing PF and

  6. Equipment design for reliability testing of protection system

    International Nuclear Information System (INIS)

    Situmorang, Johnny; Tjahjono, H.; Santosa, A. Z.; Tjahjani, S.DT.; Ismu, P.H; Haryanto, D.; Mulyanto, D.; Kusmono, S

    1999-01-01

    The equipment for reliability testing of cable of protection system has been designed as a a furnace with the electric heater have a 4 kW power, and need time 10 minute to reach the designed maximum temperature 3000C. The dimension of furnace is 800 mm diameter and 2000 mm length is isolated use rockwool isolator and coated by aluminium. For the designed maximum temperature the surface temperature is 78 0c. Assemble of specimens is arranged horizontally in the furnace. The failure criteria will be defined based on the behaviour of the load circuit in each line of cable specimens

  7. Some problems in the technique of high-voltage testing of the accelerating tube gaps in electrostatic accelerators

    International Nuclear Information System (INIS)

    Romanov, V.A.; Ivanov, V.V.; Mukhametshin, V.I.; Dmitriev, E.P.; Kidalov, A.I.

    1983-01-01

    Problems arising during high-voltage testing and training of accelerating taubes of electrostatic accelrators are discussed. A rig and technique of the accelerating tube testing and program designed for the processing of the data obtained and sorting out of the samples investigated are described

  8. Beam loading and cavity compensation for the ground test accelerator

    International Nuclear Information System (INIS)

    Jachim, S.P.; Natter, E.F.

    1989-01-01

    The Ground Test Accelerator (GTA) will be a heavily beam-loaded H/sup minus/ linac with tight tolerances on accelerating field parameters. The methods used in modeling the effects of beam loading in this machine are described. The response of the cavity to both beam and radio-frequency (RF) drive stimulus is derived, including the effects of cavity detuning. This derivation is not restricted to a small-signal approximation. An analytical method for synthesizing a predistortion network that decouples the amplitude and phase responses of the cavity is also outlined. Simulation of performance, including beam loading, is achieved through use of a control system analysis software package. A straightforward method is presented for extrapolating this work to model large coupled structures with closely spaced parasitic modes. Results to date have enabled the RF control system designs for GTA to be optimized and have given insight into their operation. 6 refs., 10 figs

  9. Commissioning of the Ground Test Accelerator Intertank Matching Section

    International Nuclear Information System (INIS)

    Johnson, K.F.; Sander, O.R.; Atkins, W.H.; Bolme, G.O.; Cole, R.; Connolly, R.; Gilpatrick, J.D.; Ingalls, W.B.; Kersteins, D.; Little, C.; Lohsen, R.A.; Lysenko, W.P.; Mottershead, C.T.; Power, J.; Rusthoi, D.P.; Sandoval, D.P.; Stevens, R.R.; Vaughn, G.; Wadlinger, E.A.; Weiss, R.; Yuan, V.

    1992-01-01

    The Ground Test Accelerator (GTA) has the objective of verifying much of the technology (physics and engineering) required for producing high-brightness, high-current H - beams. GTA commissioning is staged to verify the beam dynamics design of each major accelerator component as it is brought on-line. The commissioning stages are the 35 keV H - injector, the 2.5 MeV Radio Frequency Quadrupole (RFQ), the Intertank Matching Section (IMS), the 3.2 MeV first 2βγ Drift Tube Linac (DTL-1) module, the 8.7 MeV 2βγ DTL (modules 1--5), and the 24 MeV GTA; all 10 DTL modules. Commissioning results from the IMS beam experiments will be presented

  10. Database requirements for the Advanced Test Accelerator project

    International Nuclear Information System (INIS)

    Chambers, F.W.

    1984-01-01

    The database requirements for the Advanced Test Accelerator (ATA) project are outlined. ATA is a state-of-the-art electron accelerator capable of producing energetic (50 million electron volt), high current (10,000 ampere), short pulse (70 billionths of a second) beams of electrons for a wide variety of applications. Databasing is required for two applications. First, the description of the configuration of facility itself requires an extended database. Second, experimental data gathered from the facility must be organized and managed to insure its full utilization. The two applications are intimately related since the acquisition and analysis of experimental data requires knowledge of the system configuration. This report reviews the needs of the ATA program and current implementation, intentions, and desires. These database applications have several unique aspects which are of interest and will be highlighted. The features desired in an ultimate database system are outlined. 3 references, 5 figures

  11. Ultra-Accelerated Natural Sunlight Exposure Testing Facilities

    Science.gov (United States)

    Lewandowski, Allan A.; Jorgensen, Gary J.

    2004-11-23

    A multi-faceted concentrator apparatus for providing ultra-accelerated natural sunlight exposure testing for sample materials under controlled weathering conditions comprising: facets that receive incident natural sunlight, transmits VIS/NIR and reflects UV/VIS onto a secondary reflector that delivers a uniform flux of UV/VIS onto a sample exposure plane located near a center of a facet array in a chamber that provide concurrent levels of temperature and/or relative humidity at high levels of up to 100.times. of natural sunlight that allow sample materials to be subjected to accelerated irradiance exposure factors for a significant period of time of about 3 to 10 days to provide a corresponding time of about at least a years worth representative weathering of sample materials.

  12. Basic Concepts in Classical Test Theory: Tests Aren't Reliable, the Nature of Alpha, and Reliability Generalization as a Meta-analytic Method.

    Science.gov (United States)

    Helms, LuAnn Sherbeck

    This paper discusses the fact that reliability is about scores and not tests and how reliability limits effect sizes. The paper also explores the classical reliability coefficients of stability, equivalence, and internal consistency. Stability is concerned with how stable test scores will be over time, while equivalence addresses the relationship…

  13. Test-Retest Reliability of Computerized, Everyday Memory Measures and Traditional Memory Tests.

    Science.gov (United States)

    Youngjohn, James R.; And Others

    Test-retest reliabilities and practice effect magnitudes were considered for nine computer-simulated tasks of everyday cognition and five traditional neuropsychological tests. The nine simulated everyday memory tests were from the Memory Assessment Clinic battery as follows: (1) simple reaction time while driving; (2) divided attention (driving…

  14. Test-re-test reliability and inter-rater reliability of a digital pelvic inclinometer in young, healthy males and females.

    Science.gov (United States)

    Beardsley, Chris; Egerton, Tim; Skinner, Brendon

    2016-01-01

    Objective. The purpose of this study was to investigate the reliability of a digital pelvic inclinometer (DPI) for measuring sagittal plane pelvic tilt in 18 young, healthy males and females. Method. The inter-rater reliability and test-re-test reliabilities of the DPI for measuring pelvic tilt in standing on both the right and left sides of the pelvis were measured by two raters carrying out two rating sessions of the same subjects, three weeks apart. Results. For measuring pelvic tilt, inter-rater reliability was designated as good on both sides (ICC = 0.81-0.88), test-re-test reliability within a single rating session was designated as good on both sides (ICC = 0.88-0.95), and test-re-test reliability between two rating sessions was designated as moderate on the left side (ICC = 0.65) and good on the right side (ICC = 0.85). Conclusion. Inter-rater reliability and test-re-test reliability within a single rating session of the DPI in measuring pelvic tilt were both good, while test-re-test reliability between rating sessions was moderate-to-good. Caution is required regarding the interpretation of the test-re-test reliability within a single rating session, as the raters were not blinded. Further research is required to establish validity.

  15. Accelerated stress testing of amorphous silicon solar cells

    Science.gov (United States)

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

    1985-01-01

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

  16. ESCAR, tests of superconducting bending magnets at the accelerator site

    International Nuclear Information System (INIS)

    Gilbert, W.S.; Lambertson, G.R.; Meuser, R.B.; Rechen, J.B.

    1979-03-01

    ESCAR (Experimental Superconducting Accelerator Ring) was conceived as a project in accelerator technology development which would provide data and experience to insure that planning for larger superconducting synchrotrons would proceed in a knowledgeable and responsible manner. It was to consist of the fabrication and operation of a relatively small proton synchrotron and storage ring with superconducting magnet elements for all of the main ring. The project was funded and design work began in July 1974. During the next two years it became increasingly apparent that the funding rate was directly limiting the rate of completion of ESCAR and that an intermediate goal, a test of the unconventional aspects of the project, was desirable. To that end, twelve dipole bending magnets, one-half of those required for the total ring, were installed at the site along with the 1500 watt helium refrigerator, cryogenic distribution system, electrical power supplies, vacuum systems, and necessary instrumentation. This truncated system was put through an extended series of tests which were completed in June 1978 at which time the ESCAR Project was terminated. ESCAR, and the dipole magnets have been described previously. The results of the systems tests have also been reported. The tests involving the dipole magnets are described

  17. 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.

  18. Reliability and Validity of the Inline Skating Skill Test

    Directory of Open Access Journals (Sweden)

    Ivan Radman, Lana Ruzic, Viktoria Padovan, Vjekoslav Cigrovski, Hrvoje Podnar

    2016-09-01

    Full Text Available This study aimed to examine the reliability and validity of the inline skating skill test. Based on previous skating experience forty-two skaters (26 female and 16 male were randomized into two groups (competitive level vs. recreational level. They performed the test four times, with a recovery time of 45 minutes between sessions. Prior to testing, the participants rated their skating skill using a scale from 1 to 10. The protocol included performance time measurement through a course, combining different skating techniques. Trivial changes in performance time between the repeated sessions were determined in both competitive females/males and recreational females/males (-1.7% [95% CI: -5.8–2.6%] – 2.2% [95% CI: 0.0–4.5%]. In all four subgroups, the skill test had a low mean within-individual variation (1.6% [95% CI: 1.2–2.4%] – 2.7% [95% CI: 2.1–4.0%] and high mean inter-session correlation (ICC = 0.97 [95% CI: 0.92–0.99] – 0.99 [95% CI: 0.98–1.00]. The comparison of detected typical errors and smallest worthwhile changes (calculated as standard deviations × 0.2 revealed that the skill test was able to track changes in skaters’ performances. Competitive-level skaters needed shorter time (24.4–26.4%, all p < 0.01 to complete the test in comparison to recreational-level skaters. Moreover, moderate correlation (ρ = 0.80–0.82; all p < 0.01 was observed between the participant’s self-rating and achieved performance times. In conclusion, the proposed test is a reliable and valid method to evaluate inline skating skills in amateur competitive and recreational level skaters. Further studies are needed to evaluate the reproducibility of this skill test in different populations including elite inline skaters.

  19. Laser-accelerated particle beams for stress testing of materials.

    Science.gov (United States)

    Barberio, M; Scisciò, M; Vallières, S; Cardelli, F; Chen, S N; Famulari, G; Gangolf, T; Revet, G; Schiavi, A; Senzacqua, M; Antici, P

    2018-01-25

    Laser-driven particle acceleration, obtained by irradiation of a solid target using an ultra-intense (I > 10 18  W/cm 2 ) short-pulse (duration testing materials and are particularly suited for identifying materials to be used in harsh conditions. We show that these laser-generated protons can produce, in a very short time scale, a strong mechanical and thermal damage, that, given the short irradiation time, does not allow for recovery of the material. We confirm this by analyzing changes in the mechanical, optical, electrical, and morphological properties of five materials of interest to be used in harsh conditions.

  20. Study of variables for accelerating lifetime testing of SOFCs

    DEFF Research Database (Denmark)

    Ploner, Alexandra; Hagen, Anke; Hauch, Anne

    Solid oxide fuel cell (SOFC) applications require lifetimes of several years on the system level. A big challenge is to proof/confirm/demonstrate such exceptionally long lifetimes.Accelerated or compressed testing are possible methods. Activities in this area have been carried out without arriving...... at different current load cycling profiles revealed a strong deviation between predicted and measured lifetime [3].In this study, we present a detailed analysis of durability results for degradation mechanisms of single SOFC components as function of operating conditions. Electrochemical impedance data...

  1. Simulations and Vacuum Tests of a CLIC Accelerating Structure

    CERN Document Server

    Garion, C

    2011-01-01

    The Compact LInear Collider, under study, is based on room temperature high gradient structures. The vacuum specificities of these cavities are low conductance, large surface areas and a non-baked system. The main issue is to reach UHV conditions (typically 10-7 Pa) in a system where the residual vacuum is driven by water outgassing. A finite element model based on an analogy thermal/vacuum has been built to estimate the vacuum profile in an accelerating structure. Vacuum tests are carried out in a dedicated set-up, the vacuum performances of different configurations are presented and compared with the predictions.

  2. Verification of mechanistic-empirical design models for flexible pavements through accelerated pavement testing : technical summary.

    Science.gov (United States)

    2014-08-01

    Midwest States Accelerated Pavement Testing Pooled-Fund Program, financed by the : highway departments of Kansas, Iowa, and Missouri, has supported an accelerated : pavement testing (APT) project to validate several models incorporated in the NCHRP :...

  3. Verification of mechanistic-empirical design models for flexible pavements through accelerated pavement testing.

    Science.gov (United States)

    2014-08-01

    The Midwest States Accelerated Pavement Testing Pooled Fund Program, financed by the highway : departments of Kansas, Iowa, and Missouri, has supported an accelerated pavement testing (APT) project to : validate several models incorporated in the NCH...

  4. Accelerated pavement testing of low-volume paved roads with geocell reinforcement : [technical summary].

    Science.gov (United States)

    2015-03-01

    The Midwest States Accelerated Pavement Testing Pooled-Fund Program, financed : by the highway departments of Kansas, Iowa, Missouri, and New York, has : supported an accelerated pavement testing (APT) project to study the rehabilitation : of low-vol...

  5. Accelerated testing for studying pavement design and performance (FY 2003) : research summary.

    Science.gov (United States)

    2008-01-01

    The Midwest States Accelerated Pavement Testing Pooled Fund Program, financed by : the highway departments of Missouri, Iowa, Kansas and Nebraska, has supported an : accelerated pavement testing (APT) project to compare the performance of stabilized ...

  6. Accelerated testing for studying pavement design and performance (FY 2002) : research summary.

    Science.gov (United States)

    2004-01-01

    This report covers the Fiscal Year 2002 project conducted at the Accelerated Testing : Laboratory at Kansas State University. The project was selected and funded by the : Midwest States Accelerated Testing Pooled Fund Program, which includes Iowa, Ka...

  7. Accelerated pavement testing of low-volume paved roads with geocell reinforcement.

    Science.gov (United States)

    2015-03-01

    The Midwest States Accelerated Pavement Testing Pooled-Fund Program, financed by the highway : departments of Kansas, Iowa, Missouri, and New York, has supported an accelerated pavement testing (APT) project : to study the rehabilitation of low-volum...

  8. Selenide isotope generator for the Galileo Mission. Axially-grooved heat pipe: accelerated life test results

    International Nuclear Information System (INIS)

    1979-08-01

    The results through SIG/Galileo contract close-out of accelerated life testing performed from June 1978 to June 1979 on axially-grooved, copper/water heat pipes are presented. The primary objective of the test was to determine the expected lifetime of axially-grooved copper/water heat pipes. The heat pipe failure rate, due to either a leak or a build-up of non-condensible gas, was determined. The secondary objective of the test was to determine the effects of time and temperature on the thermal performance parameters relevant to long-term (> 50,000 h) operation on a space power generator. The results showed that the gas generation rate appears to be constant with time after an initial sharp rise although there are indications that it drops to approximately zero beyond approx. 2000 h. During the life test, the following pipe-hours were accumulated: 159,000 at 125 0 C, 54,000 at 165 0 C, 48,000 at 185 0 C, and 8500 at 225 0 C. Heated hours per pipe ranged from 1000 to 7500 with an average of 4720. Applying calculated acceleration factors yields the equivalent of 930,000 pipe-h at 125 0 C. Including the accelerated hours on vendor tested pipes raises this number to 1,430,000 pipe-hours at 125 0 C. It was concluded that, for a heat pipe temperature of 125 0 C and a mission time of 50,000 h, the demonstrated heat pipe reliability is between 80% (based on 159,000 actual pipe-h at 125 0 C) and 98% (based on 1,430,000 accelerated pipe-h at 125 0 C). Measurements indicate some degradation of heat transfer with time, but no detectable degradation of heat transport

  9. Accelerated tests for the soft error rate determination of single radiation particles in components of terrestrial and avionic electronic systems

    International Nuclear Information System (INIS)

    Flament, O.; Baggio, J.

    2010-01-01

    This paper describes the main features of the accelerated test procedures used to determine reliability data of microelectronics devices used in terrestrial environment.This paper focuses on the high energy particle test that could be performed through spallation neutron source or quasi-mono-energetic neutron or proton. Improvements of standards are illustrated with respect to the state of the art of knowledge in radiation effects and scaling down of microelectronics technologies. (authors)

  10. Accelerated test techniques for micro-circuits: Evaluation of high temperature (473 k - 573 K) accelerated life test techniques as effective microcircuit screening methods

    Science.gov (United States)

    Johnson, G. M.

    1976-01-01

    The application of high temperature accelerated test techniques was shown to be an effective method of microcircuit defect screening. Comprehensive microcircuit evaluations and a series of high temperature (473 K to 573 K) life tests demonstrated that a freak or early failure population of surface contaminated devices could be completely screened in thirty two hours of test at an ambient temperature of 523 K. Equivalent screening at 398 K, as prescribed by current Military and NASA specifications, would have required in excess of 1,500 hours of test. All testing was accomplished with a Texas Instruments' 54L10, low power triple-3 input NAND gate manufactured with a titanium- tungsten (Ti-W), Gold (Au) metallization system. A number of design and/or manufacturing anomalies were also noted with the Ti-W, Au metallization system. Further study of the exact nature and cause(s) of these anomalies is recommended prior to the use of microcircuits with Ti-W, Au metallization in long life/high reliability applications. Photomicrographs of tested circuits are included.

  11. Accelerated pavement testing of thin RCC over soil cement pavements

    Directory of Open Access Journals (Sweden)

    Zhong Wu

    2016-05-01

    Full Text Available Three full-scale roller compacted concrete (RCC pavement sections built over a soil cement base were tested under accelerated pavement testing (APT. The RCC thicknesses varied from 102 mm (4 in. to 152 mm (6 in. and to 203 mm (8 in., respectively. A bi-directional loading device with a dual-tire load assembly was used for this experiment. Each test section was instrumented with multiple pressure cells and strain gages. The objective was to evaluate the structural performance and load carrying capacity of thin RCC-surfaced pavements under accelerated loading. The APT results generally indicated that all three RCC pavement sections tested in this study possessed very high load carrying capacity; an estimated pavement life in terms of equivalent single axle load (ESAL for the thinnest RCC section (i.e., RCC thickness of 102 mm evaluated was approximately 19.2 million. It was observed that a fatigue failure would be the primary pavement distress type for a thin RCC pavement under trafficking. Specifically, the development of fatigue cracking was found to originate from a longitudinal crack at the edge or in the center of a tire print, then extended and propagated, and eventually merged with cracks of other directions. Instrumentation results were used to characterize the fatigue damage under different load magnitudes. Finally, based on the APT performance of this experiment, two fatigue models for predicting the fatigue life of thin RCC pavements were developed. Keywords: Roller compacted concrete, APT, Pavement performance, Non-destructive testing, Fatigue analysis

  12. Statistical characteristics of mechanical heart valve cavitation in accelerated testing.

    Science.gov (United States)

    Wu, Changfu; Hwang, Ned H C; Lin, Yu-Kweng M

    2004-07-01

    Cavitation damage has been observed on mechanical heart valves (MHVs) undergoing accelerated testing. Cavitation itself can be modeled as a stochastic process, as it varies from beat to beat of the testing machine. This in-vitro study was undertaken to investigate the statistical characteristics of MHV cavitation. A 25-mm St. Jude Medical bileaflet MHV (SJM 25) was tested in an accelerated tester at various pulse rates, ranging from 300 to 1,000 bpm, with stepwise increments of 100 bpm. A miniature pressure transducer was placed near a leaflet tip on the inflow side of the valve, to monitor regional transient pressure fluctuations at instants of valve closure. The pressure trace associated with each beat was passed through a 70 kHz high-pass digital filter to extract the high-frequency oscillation (HFO) components resulting from the collapse of cavitation bubbles. Three intensity-related measures were calculated for each HFO burst: its time span; its local root-mean-square (LRMS) value; and the area enveloped by the absolute value of the HFO pressure trace and the time axis, referred to as cavitation impulse. These were treated as stochastic processes, of which the first-order probability density functions (PDFs) were estimated for each test rate. Both the LRMS value and cavitation impulse were log-normal distributed, and the time span was normal distributed. These distribution laws were consistent at different test rates. The present investigation was directed at understanding MHV cavitation as a stochastic process. The results provide a basis for establishing further the statistical relationship between cavitation intensity and time-evolving cavitation damage on MHV surfaces. These data are required to assess and compare the performance of MHVs of different designs.

  13. Reliability of the Test of Wheeled Mobility (TOWM) and the Short Wheelie Test

    NARCIS (Netherlands)

    Fliess-Douer, Osnat; Van der Woude, Lucas H. V.; Vanlandewijck, Yves C.

    Objective: To assess the reliability of the Test of Wheeled Mobility (TOWM) and the Wheelie test. Design: Cohort study. Setting: Gymnasium. Participants: Manual wheelchair users (N=30, age 23-53y) with a spinal cord injury. Intervention: Participants performed the 30 skills of the TOWM and the 8

  14. Reliability of skin testing as a measure of nutritional state

    International Nuclear Information System (INIS)

    Forse, R.A.; Christou, N.; Meakins, J.L.; MacLean, L.D.; Shizgal, H.M.

    1981-01-01

    The reliability of skin testing to assess the nutritional state was evaluated in 257 patients who received total parenteral nutrition (TPN). The nutritional state was assessed by determining body composition, by multiple-isotope dilution. Immunocompetence was simultaneously evaluated by skin testing with five recall antigens. These measurements were carried out before and at two-week intervals during TPN. A statistically significant relationship existed between the response to skin testing and the nutritional state. A body composition consistent with malnutrition was present in the anergic patients, while body composition was normal in the patients who reacted normally to skin testing. However, a considerable overlap existed as 43% of the reactive patients were malnourished, and 21% of the anergic patients were normally nourished. Thirty-seven (43%) of the 86 anergic patients converted and became reactive during TPN, and their body composition improved significantly. The remaining 49 anergic patients (57%) did not convert, and their body composition did not change despite similar nutritional support. The principal difference between the two groups of anergic patients was the nature of the therapy administered. In the anergic patients who converted, therapy was aggressive and appropriate, and clinical improvement occurred in 23 (62.2%) of the patients, with a mortality of 5.4%. In the 49 patients who remained anergic, therapy was often inappropriate or unsuccessful, with clinical improvement in only three (6.1%) of the patients and a mortality of 42.8%. The data demonstrated a significant relationship between the response to skin testing and the nutritional state. However, because of the wide overlap, skin testing does not accurately assess a person's nutritional state. The persistence of the anergic state is indicative of a lack of response to therapy

  15. Reliability and Validity of the Inline Skating Skill Test.

    Science.gov (United States)

    Radman, Ivan; Ruzic, Lana; Padovan, Viktoria; Cigrovski, Vjekoslav; Podnar, Hrvoje

    2016-09-01

    This study aimed to examine the reliability and validity of the inline skating skill test. Based on previous skating experience forty-two skaters (26 female and 16 male) were randomized into two groups (competitive level vs. recreational level). They performed the test four times, with a recovery time of 45 minutes between sessions. Prior to testing, the participants rated their skating skill using a scale from 1 to 10. The protocol included performance time measurement through a course, combining different skating techniques. Trivial changes in performance time between the repeated sessions were determined in both competitive females/males and recreational females/males (-1.7% [95% CI: -5.8-2.6%] - 2.2% [95% CI: 0.0-4.5%]). In all four subgroups, the skill test had a low mean within-individual variation (1.6% [95% CI: 1.2-2.4%] - 2.7% [95% CI: 2.1-4.0%]) and high mean inter-session correlation (ICC = 0.97 [95% CI: 0.92-0.99] - 0.99 [95% CI: 0.98-1.00]). The comparison of detected typical errors and smallest worthwhile changes (calculated as standard deviations × 0.2) revealed that the skill test was able to track changes in skaters' performances. Competitive-level skaters needed shorter time (24.4-26.4%, all p skating skills in amateur competitive and recreational level skaters. Further studies are needed to evaluate the reproducibility of this skill test in different populations including elite inline skaters.

  16. 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.

  17. Reliability Analysis and Test Planning using CAPO-Test for Existing Structures

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Engelund, S.; Faber, Michael Havbro

    2000-01-01

    Evaluation of the reliability of existing concrete structures often requires that the compressive strength of the concrete is estimated on the basis of tests performed with concrete samples from the structure considered. In this paper the CAPO-test method is considered. The different sources...... of uncertainty related to this method are described. It is shown how the uncertainty in the transformation from the CAPO-test results to estimates of the concrete strength can be modeled. Further, the statistical uncertainty is modeled using Bayesian statistics. Finally, it is shown how reliability-based optimal...... planning of CAPO-tests can be performed taking into account the expected costs due to the CAPO-tests and possible repair or failure of the structure considered. An illustrative example is presented where the CAPO-test is compared with conventional concrete cylinder compression tests performed on cores...

  18. Pilot instrumentation of a Superpave test section at the Kansas Accelerated Testing laboratory

    Science.gov (United States)

    2003-04-01

    Two Superpave test sections were constructed at the Kansas Accelerated Testing Laboratory (K-ATL) with 12.5 mm (2 in) nominal maximum size Superpave mixture (SM-2A) with varying percentages (15 and 30 percent) of river sand. A 150 kN (34 kip) tandem ...

  19. ORR irradiation experiment OF-1: accelerated testing of HTGR fuel

    International Nuclear Information System (INIS)

    Tiegs, T.N.; Long, E.L. Jr.; Kania, M.J.; Thoms, K.R.; Allen, E.J.

    1977-08-01

    The OF-1 capsule, the first in a series of High-Temperature Gas-Cooled Reactor fuel irradiations in the Oak Ridge Research Reactor, was irradiated for more than 9300 hr at full reactor power (30 MW). Peak fluences of 1.08 x 10 22 neutrons/cm 2 (> 0.18 MeV) were achieved. General Atomic Company's magazine P13Q occupied the upper two-thirds of the test space and the ORNL magazine OF-1 the lower one-third. The ORNL portion tested various HTGR recycle particles and fuel bonding matrices at accelerated flux levels under reference HTGR irradiation conditions of temperature, temperature gradient, and fast fluence exposure

  20. Accelerated Leach Testing of GLASS: ALTGLASS Version 3.0

    Energy Technology Data Exchange (ETDEWEB)

    Trivelpiece, Cory L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Jantzen, Carol M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Crawford, Charles L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-12-31

    The Accelerated Leach Testing of GLASS (ALTGLASS) database is a collection of data from short- and long-term product consistency tests (PCT, ASTM C1285 A and B) on high level waste (HLW) as well as low activity waste (LAW) glasses. The database provides both U.S. and international researchers with an archive of experimental data for the purpose of studying, modeling, or validating existing models of nuclear waste glass corrosion. The ALTGLASS database is maintained and updated by researchers at the Savannah River National Laboratory (SRNL). This newest version, ALTGLASS Version 3.0, has been updated with an additional 503 rows of data representing PCT results from corrosion experiments conducted in the United States by the Savannah River National Laboratory, Pacific Northwest National Laboratory, Argonne National Laboratory, and the Vitreous State Laboratory (SRNL, PNNL, ANL, VSL, respectively) as well as the National Nuclear Laboratory (NNL) in the United Kingdom.

  1. Repair mortars based on lime. Accelerated aging tests

    Directory of Open Access Journals (Sweden)

    Martínez-Ramírez, S.

    1995-06-01

    Full Text Available The behaviour under different accelerated aging tests (freeze/thaw and crystallization cycles of a new lime mortar with biocide properties destinated to monumental repair has been studied. New mortars (which have the biocide impregnated in a clay called sepiolite have a similar behaviour to lime mortars used as a reference. After the aging tests, the biocide properties of the mortars have been tried.

    Se ha estudiado el comportamiento frente a distintos ensayos de envejecimiento acelerado (ciclos de hielo/deshielo y cristalización de sales de un nuevo mortero de cal con propiedades biocidas, destinado a la reparación monumental. Se ha comprobado que los nuevos morteros (que llevan incorporado el biocida impregnado en una arcilla denominada sepiolita tienen un comportamiento muy similar a los morteros de cal utilizados como referencia. Tras los ensayos de envejecimiento se ha visto que las propiedades biocidas de los morteros se mantienen.

  2. Accelerated Leach Testing of GLASS: ALTGLASS Version 3.0

    International Nuclear Information System (INIS)

    Trivelpiece, Cory L.; Jantzen, Carol M.; Crawford, Charles L.

    2016-01-01

    The Accelerated Leach Testing of GLASS (ALTGLASS) database is a collection of data from short- and long-term product consistency tests (PCT, ASTM C1285 A and B) on high level waste (HLW) as well as low activity waste (LAW) glasses. The database provides both U.S. and international researchers with an archive of experimental data for the purpose of studying, modeling, or validating existing models of nuclear waste glass corrosion. The ALTGLASS database is maintained and updated by researchers at the Savannah River National Laboratory (SRNL). This newest version, ALTGLASS Version 3.0, has been updated with an additional 503 rows of data representing PCT results from corrosion experiments conducted in the United States by the Savannah River National Laboratory, Pacific Northwest National Laboratory, Argonne National Laboratory, and the Vitreous State Laboratory (SRNL, PNNL, ANL, VSL, respectively) as well as the National Nuclear Laboratory (NNL) in the United Kingdom.

  3. Face Perception and Test Reliabilities in Congenital Prosopagnosia in Seven Tests

    Directory of Open Access Journals (Sweden)

    Janina Esins

    2016-01-01

    Full Text Available Congenital prosopagnosia, the innate impairment in recognizing faces, is a very heterogeneous disorder with different phenotypical manifestations. To investigate the nature of prosopagnosia in more detail, we tested 16 prosopagnosics and 21 controls with an extended test battery addressing various aspects of face recognition. Our results show that prosopagnosics exhibited significant impairments in several face recognition tasks: impaired holistic processing (they were tested amongst others with the Cambridge Face Memory Test (CFMT as well as reduced processing of configural information of faces. This test battery also revealed some new findings. While controls recognized moving faces better than static faces, prosopagnosics did not exhibit this effect. Furthermore, prosopagnosics had significantly impaired gender recognition—which is shown on a groupwise level for the first time in our study. There was no difference between groups in the automatic extraction of face identity information or in object recognition as tested with the Cambridge Car Memory Test. In addition, a methodological analysis of the tests revealed reduced reliability for holistic face processing tests in prosopagnosics. To our knowledge, this is the first study to show that prosopagnosics showed a significantly reduced reliability coefficient (Cronbach’s alpha in the CFMT compared to the controls. We suggest that compensatory strategies employed by the prosopagnosics might be the cause for the vast variety of response patterns revealed by the reduced test reliability. This finding raises the question whether classical face tests measure the same perceptual processes in controls and prosopagnosics.

  4. Test-retest reliability of a balance testing protocol with external perturbations in young healthy adults.

    Science.gov (United States)

    Robbins, Shawn M; Caplan, Ryan M; Aponte, Daniel I; St-Onge, Nancy

    2017-10-01

    External perturbations are utilized to challenge balance and mimic realistic balance threats in patient populations. The reliability of such protocols has not been established. The purpose was to examine test-retest reliability of balance testing with external perturbations. Healthy adults (n=34; mean age 23 years) underwent balance testing over two visits. Participants completed ten balance conditions in which the following parameters were combined: perturbation or non-perturbation, single or double leg, and eyes open or closed. Three trials were collected for each condition. Data were collected on a force plate and external perturbations were applied by translating the plate. Force plate center of pressure (CoP) data were summarized using 13 different CoP measures. Test-retest reliability was examined using intraclass correlation coefficients (ICC) and Bland-Altman plots. CoP measures of total speed and excursion in both anterior-posterior and medial-lateral directions generally had acceptable ICC values for perturbation conditions (ICC=0.46 to 0.87); however, many other CoP measures (e.g. range, area of ellipse) had unacceptable test-retest reliability (ICCbalance testing protocols that include external perturbations should be made to improve test-retest reliability and diminish learning including more extensive participant training and increasing the number of trials. CoP measures that consider all data points (e.g. total speed) are more reliable than those that only consider a few data points. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Test-retest reliability and predictive validity of the Implicit Association Test in children.

    Science.gov (United States)

    Rae, James R; Olson, Kristina R

    2018-02-01

    The Implicit Association Test (IAT) is increasingly used in developmental research despite minimal evidence of whether children's IAT scores are reliable across time or predictive of behavior. When test-retest reliability and predictive validity have been assessed, the results have been mixed, and because these studies have differed on many factors simultaneously (lag-time between testing administrations, domain, etc.), it is difficult to discern what factors may explain variability in existing test-retest reliability and predictive validity estimates. Across five studies (total N = 519; ages 6- to 11-years-old), we manipulated two factors that have varied in previous developmental research-lag-time and domain. An internal meta-analysis of these studies revealed that, across three different methods of analyzing the data, mean test-retest (rs of .48, .38, and .34) and predictive validity (rs of .46, .20, and .10) effect sizes were significantly greater than zero. While lag-time did not moderate the magnitude of test-retest coefficients, whether we observed domain differences in test-retest reliability and predictive validity estimates was contingent on other factors, such as how we scored the IAT or whether we included estimates from a unique sample (i.e., a sample containing gender typical and gender diverse children). Recommendations are made for developmental researchers that utilize the IAT in their research. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  6. Accelerated radiation damage test facility using a 5 MV tandem ion accelerator

    International Nuclear Information System (INIS)

    Wady, P.T.; Draude, A.; Shubeita, S.M.; Smith, A.D.; Mason, N.; Pimblott, S.M.; Jimenez-Melero, E.

    2016-01-01

    We have developed a new irradiation facility that allows to perform accelerated damage tests of nuclear reactor materials at temperatures up to 400 °C using the intense proton (<100 μA) and heavy ion (≈10 μA) beams produced by a 5 MV tandem ion accelerator. The dedicated beam line for radiation damage studies comprises: (1) beam diagnosis and focusing optical components, (2) a scanning and slit system that allows uniform irradiation of a sample area of 0.5–6 cm"2, and (3) a sample stage designed to be able to monitor in-situ the sample temperature, current deposited on the sample, and the gamma spectrum of potential radio-active nuclides produced during the sample irradiation. The beam line capabilities have been tested by irradiating a 20Cr–25Ni–Nb stabilised stainless steel with a 3 MeV proton beam to a dose level of 3 dpa. The irradiation temperature was 356 °C, with a maximum range in temperature values of ±6 °C within the first 24 h of continuous irradiation. The sample stage is connected to ground through an electrometer to measure accurately the charge deposited on the sample. The charge can be integrated in hardware during irradiation, and this methodology removes uncertainties due to fluctuations in beam current. The measured gamma spectrum allowed the identification of the main radioactive nuclides produced during the proton bombardment from the lifetimes and gamma emissions. This dedicated radiation damage beam line is hosted by the Dalton Cumbrian Facility of the University of Manchester.

  7. 4-Meter Gait Speed Test in Chronic Obstructive Pulmonary Disease: INTERRATER RELIABILITY USING A STOPWATCH.

    Science.gov (United States)

    Bisca, Gianna Waldrich; Fava, Lucas Rodrigues; Morita, Andrea Akemi; Machado, Felipe Vilaça Cavallari; Pitta, Fabio; Hernandes, Nidia Aparecida

    2017-12-14

    4-meter gait speed (4MGS) is increasingly used to assess functional performance in patients with chronic obstructive pulmonary disease. However, the current literature lacks information regarding some technical standards for this test. Therefore, the purpose of this study was to compare and to evaluate the interrater reliability between a stopwatch and video recording used as timing systems for the 4MGS in patients with chronic obstructive pulmonary disease, as well as to verify the interrater reliability between 2 observers measuring the 4MGS time using a manual stopwatch. Fifty-one patients performed the 4MGS using 4 different protocols (random order): walking at the usual and maximum speed in a 4-meter course and walking at the same 2 speeds on an 8-m course using a 2-m acceleration zone, a 4-meter timing area, and a 2-m deceleration zone. Gait speed was measured simultaneously using a stopwatch and a video recording. In a subanalysis (n = 24), 2 independent observers timed the 4MGS using a stopwatch. There was no significant difference in comparison between the 2 timing methods (P > .05 for all), and the reliability between video recording and stopwatch was excellent in all 4MGS studied protocols (intraclass correlation coefficient ≥ 0.91). Moreover, when comparing gait speed measured by 2 observers using a stopwatch, no significant difference was found among all proposed protocols (P > .05 for all), and there was also excellent reliability between the 2 independent observers (intraclass correlation coefficient ≥ 0.94). The stopwatch, a low-cost and feasible tool, is reliable as a timing device for the 4MGS in patients with chronic obstructive pulmonary disease.

  8. Bayesian analysis of heat pipe life test data for reliability demonstration testing

    International Nuclear Information System (INIS)

    Bartholomew, R.J.; Martz, H.F.

    1985-01-01

    The demonstration testing duration requirements to establish a quantitative measure of assurance of expected lifetime for heat pipes was determined. The heat pipes are candidate devices for transporting heat generated in a nuclear reactor core to thermoelectric converters for use as a space-based electric power plant. A Bayesian analysis technique is employed, utilizing a limited Delphi survey, and a geometric mean accelerated test criterion involving heat pipe power (P) and temperature (T). Resulting calculations indicate considerable test savings can be achieved by employing the method, but development testing to determine heat pipe failure mechanisms should not be circumvented

  9. Lessons learned on the Ground Test Accelerator control system

    International Nuclear Information System (INIS)

    Kozubal, A.J.; Weiss, R.E.

    1994-01-01

    When we initiated the control system design for the Ground Test Accelerator (GTA), we envisioned a system that would be flexible enough to handle the changing requirements of an experimental project. This control system would use a developers' toolkit to reduce the cost and time to develop applications for GTA, and through the use of open standards, the system would accommodate unforeseen requirements as they arose. Furthermore, we would attempt to demonstrate on GTA a level of automation far beyond that achieved by existing accelerator control systems. How well did we achieve these goals? What were the stumbling blocks to deploying the control system, and what assumptions did we make about requirements that turned out to be incorrect? In this paper we look at the process of developing a control system that evolved into what is now the ''Experimental Physics and Industrial Control System'' (EPICS). Also, we assess the impact of this system on the GTA project, as well as the impact of GTA on EPICS. The lessons learned on GTA will be valuable for future projects

  10. Laserwire at the Accelerator Test Facility 2 with submicrometer resolution

    Directory of Open Access Journals (Sweden)

    L. J. Nevay

    2014-07-01

    Full Text Available A laserwire transverse electron beam size measurement system has been developed and operated at the Accelerator Test Facility 2 at the High Energy Accelerator Research Organization, Japan (KEK. Special electron beam optics were developed to create an approximately 1×100  μm (vertical×horizontal electron beam at the laserwire location, which was profiled using 150 mJ, 71 ps laser pulses with a wavelength of 532 nm. The precise characterization of the laser propagation allows the non-Gaussian laserwire scan profiles caused by the laser divergence to be deconvolved. A minimum vertical electron beam size of 1.07±0.06(stat±0.05(sys  μm was measured. A vertically focusing quadrupole just before the laserwire was varied while making laserwire measurements and the projected vertical emittance was measured to be 82.56±3.04  pm rad.

  11. GPUs, a new tool of acceleration in CFD: efficiency and reliability on smoothed particle hydrodynamics methods.

    Directory of Open Access Journals (Sweden)

    Alejandro C Crespo

    Full Text Available Smoothed Particle Hydrodynamics (SPH is a numerical method commonly used in Computational Fluid Dynamics (CFD to simulate complex free-surface flows. Simulations with this mesh-free particle method far exceed the capacity of a single processor. In this paper, as part of a dual-functioning code for either central processing units (CPUs or Graphics Processor Units (GPUs, a parallelisation using GPUs is presented. The GPU parallelisation technique uses the Compute Unified Device Architecture (CUDA of nVidia devices. Simulations with more than one million particles on a single GPU card exhibit speedups of up to two orders of magnitude over using a single-core CPU. It is demonstrated that the code achieves different speedups with different CUDA-enabled GPUs. The numerical behaviour of the SPH code is validated with a standard benchmark test case of dam break flow impacting on an obstacle where good agreement with the experimental results is observed. Both the achieved speed-ups and the quantitative agreement with experiments suggest that CUDA-based GPU programming can be used in SPH methods with efficiency and reliability.

  12. A Test Stand for Ion Sources of Ultimate Reliability

    International Nuclear Information System (INIS)

    Enparantza, R.; Uriarte, L.; Romano, P.; Alonso, J.; Ariz, I.; Egiraun, M.; Bermejo, F. J.; Etxebarria, V.; Lucas, J.; Del Rio, J. M.; Letchford, A.; Faircloth, D.; Stockli, M.

    2009-01-01

    The rationale behind the ITUR project is to perform a comparison between different kinds of H - ion sources using the same beam diagnostics setup. In particular, a direct comparison will be made in terms of the emittance characteristics of Penning Type sources such as those currently in use in the injector for the ISIS (UK) Pulsed Neutron Source and those of volumetric type such as that driving the injector for the ORNL Spallation Neutron Source (TN, U.S.A.). The endeavour here pursued is thus to build an Ion Source Test Stand where virtually any type of source can be tested and its features measured and, thus compared to the results of other sources under the same gauge. It would be possible then to establish a common ground for effectively comparing different ion sources. The long term objectives are thus to contribute towards building compact sources of minimum emittance, maximum performance, high reliability-availability, high percentage of desired particle production, stability and high brightness. The project consortium is lead by Tekniker-IK4 research centre and partners are companies Elytt Energy and Jema Group. The technical viability is guaranteed by the collaboration between the project consortium and several scientific institutions, such the CSIC (Spain), the University of the Basque Country (Spain), ISIS (STFC-UK), SNS (ORNL-USA) and CEA in Saclay (France).

  13. Applying reliability centered maintenance analysis principles to inservice testing

    International Nuclear Information System (INIS)

    Flude, J.W.

    1994-01-01

    Federal regulations require nuclear power plants to use inservice test (IST) programs to ensure the operability of safety-related equipment. IST programs are based on American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code requirements. Many of these plants also use Reliability Centered Maintenance (RCM) to optimize system maintenance. ASME Code requirements are hard to change. The process for requesting authority to use an alternate strategy is long and expensive. The difficulties of obtaining this authority make the use of RCM method on safety-related systems not cost effective. An ASME research task force on Risk Based Inservice Testing is investigating changing the Code. The change will allow plants to apply RCM methods to the problem of maintenance strategy selection for safety-related systems. The research task force is working closely with the Codes and Standards sections to develop a process related to the RCM process. Some day plants will be able to use this process to develop more efficient and safer maintenance strategies

  14. A statistical comparison of accelerated concrete testing methods

    OpenAIRE

    Denny Meyer

    1997-01-01

    Accelerated curing results, obtained after only 24 hours, are used to predict the 28 day strength of concrete. Various accelerated curing methods are available. Two of these methods are compared in relation to the accuracy of their predictions and the stability of the relationship between their 24 hour and 28 day concrete strength. The results suggest that Warm Water accelerated curing is preferable to Hot Water accelerated curing of concrete. In addition, some other methods for improving the...

  15. Failure-censored accelerated life test sampling plans for Weibull distribution under expected test time constraint

    International Nuclear Information System (INIS)

    Bai, D.S.; Chun, Y.R.; Kim, J.G.

    1995-01-01

    This paper considers the design of life-test sampling plans based on failure-censored accelerated life tests. The lifetime distribution of products is assumed to be Weibull with a scale parameter that is a log linear function of a (possibly transformed) stress. Two levels of stress higher than the use condition stress, high and low, are used. Sampling plans with equal expected test times at high and low test stresses which satisfy the producer's and consumer's risk requirements and minimize the asymptotic variance of the test statistic used to decide lot acceptability are obtained. The properties of the proposed life-test sampling plans are investigated

  16. CPM Test-Retest Reliability: "Standard" vs "Single Test-Stimulus" Protocols.

    Science.gov (United States)

    Granovsky, Yelena; Miller-Barmak, Adi; Goldstein, Oren; Sprecher, Elliot; Yarnitsky, David

    2016-03-01

    Assessment of pain inhibitory mechanisms using conditioned pain modulation (CPM) is relevant clinically in prediction of pain and analgesic efficacy. Our objective is to provide necessary estimates of intersession CPM reliability, to enable transformation of the CPM paradigm into a clinical tool. Two cohorts of young healthy subjects (N = 65) participated in two dual-session studies. In Study I, a Bath-Thermode CPM protocol was used, with hot water immersion and contact heat as conditioning- and test-stimuli, respectively, in a classical parallel CPM design introducing test-stimulus first, and then the conditioning- and repeated test-stimuli in parallel. Study II consisted of two CPM protocols: 1) Two-Thermodes, one for each of the stimuli, in the same parallel design as above, and 2) single test-stimulus (STS) protocol with a single administration of a contact heat test-stimulus, partially overlapped in time by a remote shorter contact heat as conditioning stimulus. Test-retest reliability was assessed within 3-7 days. The STS-CPM had superior reliability intraclass correlation (ICC 2 ,: 1  = 0.59) over Bath-Thermode (ICC 2 ,: 1  = 0.34) or Two-Thermodes (ICC 2 ,: 1  = 0.21) protocols. The hand immersion conditioning pain had higher reliability than thermode pain (ICC 2 ,: 1  = 0.76 vs ICC 2 ,: 1  = 0.16). Conditioned test-stimulus pain scores were of good (ICC 2 ,: 1  = 0.62) or fair (ICC 2 ,: 1  = 0.43) reliability for the Bath-Thermode and the STS, respectively, but not for the Two-Thermodes protocol (ICC 2 ,: 1  = 0.20). The newly developed STS-CPM paradigm was more reliable than other CPM protocols tested here, and should be further investigated for its clinical relevance. It appears that large contact size of the conditioning-stimulus and use of single rather than dual test-stimulus pain contribute to augmentation of CPM reliability. © 2015 American Academy of Pain Medicine. All rights reserved. For permissions, please e

  17. Integration Test of the High Voltage Hall Accelerator System Components

    Science.gov (United States)

    Kamhawi, Hani; Haag, Thomas; Huang, Wensheng; Pinero, Luis; Peterson, Todd; Dankanich, John

    2013-01-01

    NASA Glenn Research Center is developing a 4 kilowatt-class Hall propulsion system for implementation in NASA science missions. NASA science mission performance analysis was completed using the latest high voltage Hall accelerator (HiVHAc) and Aerojet-Rocketdyne's state-of-the-art BPT-4000 Hall thruster performance curves. Mission analysis results indicated that the HiVHAc thruster out performs the BPT-4000 thruster for all but one of the missions studied. Tests of the HiVHAc system major components were performed. Performance evaluation of the HiVHAc thruster at NASA Glenn's vacuum facility 5 indicated that thruster performance was lower than performance levels attained during tests in vacuum facility 12 due to the lower background pressures attained during vacuum facility 5 tests when compared to vacuum facility 12. Voltage-Current characterization of the HiVHAc thruster in vacuum facility 5 showed that the HiVHAc thruster can operate stably for a wide range of anode flow rates for discharge voltages between 250 and 600 volts. A Colorado Power Electronics enhanced brassboard power processing unit was tested in vacuum for 1,500 hours and the unit demonstrated discharge module efficiency of 96.3% at 3.9 kilowatts and 650 volts. Stand-alone open and closed loop tests of a VACCO TRL 6 xenon flow control module were also performed. An integrated test of the HiVHAc thruster, brassboard power processing unit, and xenon flow control module was performed and confirmed that integrated operation of the HiVHAc system major components. Future plans include continuing the maturation of the HiVHAc system major components and the performance of a single-string integration test.

  18. Vibrational Stability of SRF Accelerator Test Facility at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    McGee, M.W.; Volk, J.T.; /Fermilab

    2009-05-01

    Recently developed, the Superconducting Radio Frequency (SRF) Accelerator Test Facilities at Fermilab support the International Linear Collider (ILC), High Intensity Neutrino Source (HINS), a new high intensity injector (Project X) and other future machines. These facilities; Meson Detector Building (MDB) and New Muon Lab (NML) have very different foundations, structures, relative elevations with respect to grade level and surrounding soil composition. Also, there are differences in the operating equipment and their proximity to the primary machine. All the future machines have stringent operational stability requirements. The present study examines both near-field and ambient vibration in order to develop an understanding of the potential contribution of near-field sources (e.g. compressors, ultra-high and standard vacuum equipment, klystrons, modulators, utility fans and pumps) and distant noise sources to the overall system displacements. Facility vibration measurement results and methods of possible isolation from noise sources are presented and discussed.

  19. A flexible and configurable system to test accelerator magnets

    Energy Technology Data Exchange (ETDEWEB)

    Jerzy M. Nogiec et al.

    2001-07-20

    Fermilab's accelerator magnet R and D programs, including production of superconducting high gradient quadrupoles for the LHC insertion regions, require rigorous yet flexible magnetic measurement systems. Measurement systems must be capable of handling various types of hardware and extensible to all measurement technologies and analysis algorithms. A tailorable software system that satisfies these requirements is discussed. This single system, capable of distributed parallel signal processing, is built on top of a flexible component-based framework that allows for easy reconfiguration and run-time modification. Both core and domain-specific components can be assembled into various magnet test or analysis systems. The system configured to comprise a rotating coil harmonics measurement is presented. Technologies as Java, OODB, XML, JavaBeans, software bus and component-based architectures are used.

  20. Beam based alignment at the KEK accelerator test facility

    International Nuclear Information System (INIS)

    Ross, M.; Nelson, J.; Woodley, M.; Wolski, A.

    2002-01-01

    The KEK Accelerator Test Facility (ATF) damping ring is a prototype low emittance source for the NLC/JLC linear collider. To achieve the goal normalized vertical emittance gey = 20 nm-rad, magnet placement accuracy better than 30 mm must be achieved. Accurate beam-based alignment (BBA) is required. The ATF arc optics uses a FOBO cell with two horizontally focusing quadrupoles, two sextupoles and a horizontally defocusing gradient dipole, all of which must be aligned with BBA. BBA at ATF uses the quadrupole and sextupole trim windings to find the trajectory through the center of each magnet. The results can be interpreted to assess the accuracy of the mechanical alignment and the beam position monitor offsets

  1. Accelerated Aging Test for Plastic Scintillator Gamma Ray Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2017-05-12

    Polyvinyl toluene (PVT) and polystyrene (PS), collectively referred to as “plastic scintillator,” are synthetic polymer materials used to detect gamma radiation, and are commonly used in instrumentation. Recent studies have revealed that plastic scintillator undergoes an environmentally related material degradation that adversely affects performance under certain conditions and histories. A significant decrease in gamma ray sensitivity has been seen in some detectors in systems as they age. The degradation of sensitivity of plastic scintillator over time is due to a variety of factors, and the term “aging” is used to encompass all factors. Some plastic scintillator samples show no aging effects (no significant change in sensitivity over more than 10 years), while others show severe aging (significant change in sensitivity in less than 5 years). Aging effects arise from weather (variations in heat and humidity), chemical exposure, mechanical stress, light exposure, and loss of volatile components. The damage produced by these various causes can be cumulative, causing observable damage to increase over time. Damage may be reversible up to some point, but becomes permanent under some conditions. It has been demonstrated that exposure of plastic scintillator in an environmental chamber to 30 days of high temperature and humidity (90% relative humidity and 55°C) followed by a single cycle to cold temperature (-30°C) will produce severe fogging in all PVT samples. This thermal cycle will be referred to as the “Accelerated Aging Test.” This document describes the procedure for performing this Accelerated Aging Test.

  2. Accelerated radiation damage test facility using a 5 MV tandem ion accelerator

    Science.gov (United States)

    Wady, P. T.; Draude, A.; Shubeita, S. M.; Smith, A. D.; Mason, N.; Pimblott, S. M.; Jimenez-Melero, E.

    2016-01-01

    We have developed a new irradiation facility that allows to perform accelerated damage tests of nuclear reactor materials at temperatures up to 400 °C using the intense proton (spectrum of potential radio-active nuclides produced during the sample irradiation. The beam line capabilities have been tested by irradiating a 20Cr-25Ni-Nb stabilised stainless steel with a 3 MeV proton beam to a dose level of 3 dpa. The irradiation temperature was 356 °C, with a maximum range in temperature values of ±6 °C within the first 24 h of continuous irradiation. The sample stage is connected to ground through an electrometer to measure accurately the charge deposited on the sample. The charge can be integrated in hardware during irradiation, and this methodology removes uncertainties due to fluctuations in beam current. The measured gamma spectrum allowed the identification of the main radioactive nuclides produced during the proton bombardment from the lifetimes and gamma emissions. This dedicated radiation damage beam line is hosted by the Dalton Cumbrian Facility of the University of Manchester.

  3. Evaluation of accelerated stability test conditions for medicated chewing gums.

    Science.gov (United States)

    Maggi, Lauretta; Conte, Ubaldo; Nhamias, Alain; Grenier, Pascal; Vergnault, Guy

    2013-10-01

    The overall stability of medicated chewing gums is investigated under different storage conditions. Active substances with different chemical stabilities in solid state are chosen as model drugs. The dosage form is a three layer tablet obtained by direct compression. The gum core contains the active ingredient while the external layers are formulated to prevent gum adhesion to the punches of the tableting machine. Two accelerated test conditions (40°C/75% RH and 30°C/65% RH) are performed for 6 months. Furthermore, a long-term stability test at room conditions is conducted to verify the predictability of the results obtained from the stress tests. Some drugs are stable in all the conditions tested, but other drugs, generally considered stable in solid dosage forms, have shown relevant stability problems particularly when stress test conditions are applied to this particular semi-solid dosage forms. For less stable drugs, the stress conditions of 40°C/75% RH are not always predictable of chewing gum stability at room temperature and may produce false negative; intermediate conditions, 30°C/65% RH, are more predictive for this purpose, the results of drug content found after 6 months at intermediate stress conditions and 12 months at room conditions are generally comparable. But the results obtained show that only long-term conditions stability tests gave consistent results. During aging, the semi solid nature of the gum base itself, may also influence the drug delivery rate during chewing and great attention should be given also to the dissolution stability.

  4. Test-retest reliability and validity of the Sniffin' TOM odor memory test.

    Science.gov (United States)

    Croy, Ilona; Zehner, Cora; Larsson, Maria; Zucco, Gesualdo M; Hummel, Thomas

    2015-03-01

    Few attempts have been made to develop an olfactory test that captures episodic retention of olfactory information. Assessment of episodic odor memory is of particular interest in aging and in the cognitively impaired as both episodic memory deficits and olfactory loss have been targeted as reliable hallmarks of cognitive decline and impending dementia. Here, 96 healthy participants (18-92 years) and an additional 19 older people with mild cognitive impairment were tested (73-82 years). Participants were presented with 8 common odors with intentional encoding instructions that were followed by a yes-no recognition test. After recognition completion, participants were asked to identify all odors by means of free or cued identification. A retest of the odor memory test (Sniffin' TOM = test of odor memory) took place 17 days later. The results revealed satisfactory test-retest reliability (0.70) of odor recognition memory. Both recognition and identification performance were negatively affected by age and more pronounced among the cognitively impaired. In conclusion, the present work presents a reliable, valid, and simple test of episodic odor recognition memory that may be used in clinical groups where both episodic memory deficits and olfactory loss are prevalent preclinically such as Alzheimer's disease. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. Effects of Differential Item Functioning on Examinees' Test Performance and Reliability of Test

    Science.gov (United States)

    Lee, Yi-Hsuan; Zhang, Jinming

    2017-01-01

    Simulations were conducted to examine the effect of differential item functioning (DIF) on measurement consequences such as total scores, item response theory (IRT) ability estimates, and test reliability in terms of the ratio of true-score variance to observed-score variance and the standard error of estimation for the IRT ability parameter. The…

  6. The Test-Retest Reliability of New Generation Power Indices of Wingate All-Out Test

    Directory of Open Access Journals (Sweden)

    Ozgur Ozkaya

    2018-04-01

    Full Text Available Although reliability correlations of traditional power indices of the Wingate test have been well documented, no study has analyzed new generation power indices based on milliseconds obtained from a Peak Bike. The purpose of this study was to investigate the retest reliability of new generation power indices. Thirty-two well-trained male athletes who were specialized in basketball, football, tennis, or track and field volunteered to take part in the study (age: 24.3 ± 2.2 years; body mass: 77 ± 8.3 kg; height: 180.3 ± 6.3 cm. Participants performed two Wingate all-out sessions on two separate days. Intra-class correlation coefficient (ICC, standard error measurement (SEM, smallest real differences (SRD and coefficient of variation (CV scores were analyzed based on the test and retest data. Reliability results of traditional power indices calculated based on 5-s means such as peak power, average power, power drop, and fatigue index ratio were similar with the previous findings in literature (ICC ≥ 0.94; CV ≤ 2.8%; SEM ≤ 12.28; SRD% ≤ 7.7%. New generation power indices such as peak power, average power, lowest power, power drop, fatigue index, power decline, maximum speed as rpm, and amount of total energy expenditure demonstrated high reliability (ICC ≥ 0.94; CV ≤ 4.3%; SEM ≤ 10.36; SRD% ≤ 8.8%. Time to peak power, time at maximum speed, and power at maximum speed showed a moderate level of reliability (ICC ≥ 0.73; CV ≤ 8.9%; SEM ≤ 63.01; SRD% ≤ 22.4%. The results of this study indicate that reliability correlations and SRD% of new generation power and fatigue-related indices are similar with traditional 5-s means. However, new time-related indices are very sensitive and moderately reliable.

  7. Advanced Beamline Design for Fermilab's Advanced Superconducting Test Accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Prokop, Christopher [Northern Illinois Univ., DeKalb, IL (United States)

    2014-01-01

    The Advanced Superconducting Test Accelerator (ASTA) at Fermilab is a new electron accelerator currently in the commissioning stage. In addition to testing superconducting accelerating cavities for future accelerators, it is foreseen to support a variety of Advanced Accelerator R&D (AARD) experiments. Producing the required electron bunches with the expected flexibility is challenging. The goal of this dissertation is to explore via numerical simulations new accelerator beamlines that can enable the advanced manipulation of electron bunches. The work especially includes the design of a low-energy bunch compressor and a study of transverse-to-longitudinal phase space exchangers.

  8. Linear Accelerator Test Facility at LNF Conceptual Design Report

    CERN Document Server

    Valente, Paolo; Bolli, Bruno; Buonomo, Bruno; Cantarella, Sergio; Ceccarelli, Riccardo; Cecchinelli, Alberto; Cerafogli, Oreste; Clementi, Renato; Di Giulio, Claudio; Esposito, Adolfo; Frasciello, Oscar; Foggetta, Luca; Ghigo, Andrea; Incremona, Simona; Iungo, Franco; Mascio, Roberto; Martelli, Stefano; Piermarini, Graziano; Sabbatini, Lucia; Sardone, Franco; Sensolini, Giancarlo; Ricci, Ruggero; Rossi, Luis Antonio; Rotundo, Ugo; Stella, Angelo; Strabioli, Serena; Zarlenga, Raffaele

    2016-01-01

    Test beam and irradiation facilities are the key enabling infrastructures for research in high energy physics (HEP) and astro-particles. In the last 11 years the Beam-Test Facility (BTF) of the DA{\\Phi}NE accelerator complex in the Frascati laboratory has gained an important role in the European infrastructures devoted to the development and testing of particle detectors. At the same time the BTF operation has been largely shadowed, in terms of resources, by the running of the DA{\\Phi}NE electron-positron collider. The present proposal is aimed at improving the present performance of the facility from two different points of view: extending the range of application for the LINAC beam extracted to the BTF lines, in particular in the (in some sense opposite) directions of hosting fundamental physics and providing electron irradiation also for industrial users; extending the life of the LINAC beyond or independently from its use as injector of the DA{\\Phi}NE collider, as it is also a key element of the electron/...

  9. Calibration of full-scale accelerated pavement testing data using long-term pavement performance data

    CSIR Research Space (South Africa)

    VdM Steyn, WJ

    2012-09-01

    Full Text Available Accelerated Pavement Testing (APT) has always been conducted with the objective of improving the understanding of real pavements under real traffic and environmental conditions. While APT provides an accelerated view of some of the major structural...

  10. Test re-test reliability and construct validity of the star-track test of manual dexterity

    DEFF Research Database (Denmark)

    Kildebro, Niels; Amirian, Ilda; Gögenur, Ismail

    2015-01-01

    Objectives. We wished to determine test re-test reliability and construct validity of the star-track test of manual dexterity. Design. Test re-test reliability was examined in a controlled study. Construct validity was tested in a blinded randomized crossover study. Setting. The study was performed...... at a university hospital in Denmark. Participants. A total of 11 subjects for test re-test and 20 subjects for the construct validity study were included. All subjects were healthy volunteers. Intervention. The test re-test trial had two measurements with 2 days pause in between. The interventions...... in the construct validity study included baseline measurement, intervention 1: fatigue, intervention 2: stress, and intervention 3: fatigue and stress. There was a 2 day pause between each intervention. Main outcome measure. An integrated measure of completion time and number of errors was used. Results. All...

  11. A Reliability Test of a Complex System Based on Empirical Likelihood

    OpenAIRE

    Zhou, Yan; Fu, Liya; Zhang, Jun; Hui, Yongchang

    2016-01-01

    To analyze the reliability of a complex system described by minimal paths, an empirical likelihood method is proposed to solve the reliability test problem when the subsystem distributions are unknown. Furthermore, we provide a reliability test statistic of the complex system and extract the limit distribution of the test statistic. Therefore, we can obtain the confidence interval for reliability and make statistical inferences. The simulation studies also demonstrate the theorem results.

  12. 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.

  13. Failure modes and effects criticality analysis and accelerated life testing of LEDs for medical applications

    Science.gov (United States)

    Sawant, M.; Christou, A.

    2012-12-01

    While use of LEDs in Fiber Optics and lighting applications is common, their use in medical diagnostic applications is not very extensive. Since the precise value of light intensity will be used to interpret patient results, understanding failure modes [1-4] is very important. We used the Failure Modes and Effects Criticality Analysis (FMECA) tool to identify the critical failure modes of the LEDs. FMECA involves identification of various failure modes, their effects on the system (LED optical output in this context), their frequency of occurrence, severity and the criticality of the failure modes. The competing failure modes/mechanisms were degradation of: active layer (where electron-hole recombination occurs to emit light), electrodes (provides electrical contact to the semiconductor chip), Indium Tin Oxide (ITO) surface layer (used to improve current spreading and light extraction), plastic encapsulation (protective polymer layer) and packaging failures (bond wires, heat sink separation). A FMECA table is constructed and the criticality is calculated by estimating the failure effect probability (β), failure mode ratio (α), failure rate (λ) and the operating time. Once the critical failure modes were identified, the next steps were generation of prior time to failure distribution and comparing with our accelerated life test data. To generate the prior distributions, data and results from previous investigations were utilized [5-33] where reliability test results of similar LEDs were reported. From the graphs or tabular data, we extracted the time required for the optical power output to reach 80% of its initial value. This is our failure criterion for the medical diagnostic application. Analysis of published data for different LED materials (AlGaInP, GaN, AlGaAs), the Semiconductor Structures (DH, MQW) and the mode of testing (DC, Pulsed) was carried out. The data was categorized according to the materials system and LED structure such as AlGaInP-DH-DC, Al

  14. Long-term storage life of light source modules by temperature cycling accelerated life test

    International Nuclear Information System (INIS)

    Sun Ningning; Tan Manqing; Li Ping; Jiao Jian; Guo Xiaofeng; Guo Wentao

    2014-01-01

    Light source modules are the most crucial and fragile devices that affect the life and reliability of the interferometric fiber optic gyroscope (IFOG). While the light emitting chips were stable in most cases, the module packaging proved to be less satisfactory. In long-term storage or the working environment, the ambient temperature changes constantly and thus the packaging and coupling performance of light source modules are more likely to degrade slowly due to different materials with different coefficients of thermal expansion in the bonding interface. A constant temperature accelerated life test cannot evaluate the impact of temperature variation on the performance of a module package, so the temperature cycling accelerated life test was studied. The main failure mechanism affecting light source modules is package failure due to solder fatigue failure including a fiber coupling shift, loss of cooling efficiency and thermal resistor degradation, so the Norris-Landzberg model was used to model solder fatigue life and determine the activation energy related to solder fatigue failure mechanism. By analyzing the test data, activation energy was determined and then the mean life of light source modules in different storage environments with a continuously changing temperature was simulated, which has provided direct reference data for the storage life prediction of IFOG. (semiconductor devices)

  15. Basics of Bayesian reliability estimation from attribute test data

    International Nuclear Information System (INIS)

    Martz, H.F. Jr.; Waller, R.A.

    1975-10-01

    The basic notions of Bayesian reliability estimation from attribute lifetest data are presented in an introductory and expository manner. Both Bayesian point and interval estimates of the probability of surviving the lifetest, the reliability, are discussed. The necessary formulas are simply stated, and examples are given to illustrate their use. In particular, a binomial model in conjunction with a beta prior model is considered. Particular attention is given to the procedure for selecting an appropriate prior model in practice. Empirical Bayes point and interval estimates of reliability are discussed and examples are given. 7 figures, 2 tables

  16. Fast Extraction Kicker for the Accelerator Test Facility

    International Nuclear Information System (INIS)

    De Santis, Stefano; Urakawa, Junji; Naito, Takashi

    2007-01-01

    We present the results of a study for the design of a fast extraction kicker to be installed in the Accelerator Test Facility ring at KEK. This activity is carried on in the framework of the ATF2 project, which will be built on the KEK Tsukuba campus as an extension of the existing ATF, taking advantage of the worlds smallest normalized emittance achieved there. ATF2's primary goal is to operate as a test facility and establish the hardware and beam handling technologies envisaged for the International Linear Collider. In particular, the fast extraction kicker object of the present paper is an important component of the ILC damping rings, since its rise and fall time define the minimum distance between bunches and ultimately the damping rings length itself. Building on the initial results presented at EPAC '06, we report on the present status of the kicker design and define the minimum characteristics for pulsers and other subsystems. In addition to the original scheme with multiple stripline modules producing a total deflection of 5 mrad, we also investigated a scheme with a single kicker module for a reduced deflection of 1 mrad placed inside a closed orbit bump, which takes the electron closer to the extraction septum

  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. Preliminary analysis of accelerated space flight ionizing radiation testing

    Science.gov (United States)

    Wilson, J. W.; Stock, L. V.; Carter, D. J.; Chang, C. K.

    1982-01-01

    A preliminary analysis shows that radiation dose equivalent to 30 years in the geosynchronous environment can be accumulated in a typical composite material exposed to space for 2 years or less onboard a spacecraft orbiting from perigee of 300 km out to the peak of the inner electron belt (approximately 2750 km). Future work to determine spacecraft orbits better tailored to materials accelerated testing is indicated. It is predicted that a range of 10 to the 9th power to 10 to the 10th power rads would be accumulated in 3-6 mil thick epoxy/graphite exposed by a test spacecraft orbiting in the inner electron belt. This dose is equivalent to the accumulated dose that this material would be expected to have after 30 years in a geosynchronous orbit. It is anticipated that material specimens would be brought back to Earth after 2 years in the radiation environment so that space radiation effects on materials could be analyzed by laboratory methods.

  19. Degradation mechanisms and accelerated testing in PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory

    2010-01-01

    The durability of PEM fuel cells is a major barrier to the commercialization of these systems for stationary and transportation power applications. Although there has been recent progress in improving durability, further improvements are needed to meet the commercialization targets. Past improvements have largely been made possible because of the fundamental understanding of the underlying degradation mechanisms. By investigating component and cell degradation modes; defining the fundamental degradation mechanisms of components and component interactions new materials can be designed to improve durability. Various factors have been shown to affect the useful life of PEM fuel cells. Other issues arise from component optimization. Operational conditions (such as impurities in either the fuel and oxidant stream), cell environment, temperature (including subfreezing exposure), pressure, current, voltage, etc.; or transient versus continuous operation, including start-up and shutdown procedures, represent other factors that can affect cell performance and durability. The need for Accelerated Stress Tests (ASTs) can be quickly understood given the target lives for fuel cell systems: 5000 hours ({approx} 7 months) for automotive, and 40,000 hrs ({approx} 4.6 years) for stationary systems. Thus testing methods that enable more rapid screening of individual components to determine their durability characteristics, such as off-line environmental testing, are needed for evaluating new component durability in a reasonable turn-around time. This allows proposed improvements in a component to be evaluated rapidly and independently, subsequently allowing rapid advancement in PEM fuel cell durability. These tests are also crucial to developers in order to make sure that they do not sacrifice durability while making improvements in costs (e.g. lower platinum group metal [PGM] loading) and performance (e.g. thinner membrane or a GDL with better water management properties). To

  20. A statistical comparison of accelerated concrete testing methods

    Directory of Open Access Journals (Sweden)

    Denny Meyer

    1997-01-01

    Full Text Available Accelerated curing results, obtained after only 24 hours, are used to predict the 28 day strength of concrete. Various accelerated curing methods are available. Two of these methods are compared in relation to the accuracy of their predictions and the stability of the relationship between their 24 hour and 28 day concrete strength. The results suggest that Warm Water accelerated curing is preferable to Hot Water accelerated curing of concrete. In addition, some other methods for improving the accuracy of predictions of 28 day strengths are suggested. In particular the frequency at which it is necessary to recalibrate the prediction equation is considered.

  1. Accelerators

    CERN Multimedia

    CERN. Geneva

    2001-01-01

    The talk summarizes the principles of particle acceleration and addresses problems related to storage rings like LEP and LHC. Special emphasis will be given to orbit stability, long term stability of the particle motion, collective effects and synchrotron radiation.

  2. Photometric and Colorimetric Assessment of LED Chip Scale Packages by Using a Step-Stress Accelerated Degradation Test (SSADT) Method.

    Science.gov (United States)

    Qian, Cheng; Fan, Jiajie; Fang, Jiayi; Yu, Chaohua; Ren, Yi; Fan, Xuejun; Zhang, Guoqi

    2017-10-16

    By solving the problem of very long test time on reliability qualification for Light-emitting Diode (LED) products, the accelerated degradation test with a thermal overstress at a proper range is regarded as a promising and effective approach. For a comprehensive survey of the application of step-stress accelerated degradation test (SSADT) in LEDs, the thermal, photometric, and colorimetric properties of two types of LED chip scale packages (CSPs), i.e., 4000 °K and 5000 °K samples each of which was driven by two different levels of currents (i.e., 120 mA and 350 mA, respectively), were investigated under an increasing temperature from 55 °C to 150 °C and a systemic study of driving current effect on the SSADT results were also reported in this paper. During SSADT, junction temperatures of the test samples have a positive relationship with their driving currents. However, the temperature-voltage curve, which represents the thermal resistance property of the test samples, does not show significant variance as long as the driving current is no more than the sample's rated current. But when the test sample is tested under an overdrive current, its temperature-voltage curve is observed as obviously shifted to the left when compared to that before SSADT. Similar overdrive current affected the degradation scenario is also found in the attenuation of Spectral Power Distributions (SPDs) of the test samples. As used in the reliability qualification, SSADT provides explicit scenes on color shift and correlated color temperature (CCT) depreciation of the test samples, but not on lumen maintenance depreciation. It is also proved that the varying rates of the color shift and CCT depreciation failures can be effectively accelerated with an increase of the driving current, for instance, from 120 mA to 350 mA. For these reasons, SSADT is considered as a suitable accelerated test method for qualifying these two failure modes of LED CSPs.

  3. Test Re-Test Reliability of Four Versions of the 3-Cone Test in Non-Athletic Men

    Directory of Open Access Journals (Sweden)

    Jason G. Langley, Robert D. Chetlin

    2017-03-01

    Full Text Available Until recently, measurement and evaluation in sport science, especially agility testing, has not always included key elements of proper test construction. Often tests are published without reporting reliability and validity analysis for a specific population. The purpose of the present study was to examine the test re-test reliability of four versions of the 3-Cone Test (3CT, and provide guidance on proper test construction for testing agility in athletic populations. Forty male students enrolled in classes in the Department of Physical Education at a mid-Atlantic university participated. On each of test day participants performed 10 trials. In random order, they performed three trials to the right (3CTR, standard test, three to the left (3CTL, and two modified trials (3CTAR and 3CTAL, which included a reactive component in which a visual cue was given to indicate direction. Intra-class correlation coefficients (ICC indicated a moderate to high reliability for the four tests, 3CTR 0.79 (0.64-0.88, 95%CI, 3CTL 0.73 (0.55-0.85, 3CTAR 0.85(0.74-0.92, and 3CTAL 0.79 (0.64-0.88. Small standard error of the measurement (SEM was found; range 0.09 to 0.10. Pearson correlations between tests were high (0.82-0.92 on day one as well as day two (0.72-0.85. These results indicate each version of the 3-Cone Test is reliable; however, further tests are needed with specific athletic populations. Only the 3CTAR and 3CTAL are tests of agility due to the inclusion of a reactive component. Future studies examining agility testing and training should incorporate technological elements, including automated timing systems and motion capture analysis. Such instrumentation will allow for optimal design of tests that simulate sport-specific game conditions.

  4. Isokinetic Strength and Endurance Tests used Pre- and Post-Spaceflight: Test-Retest Reliability

    Science.gov (United States)

    Laughlin, Mitzi S.; Lee, Stuart M. C.; Loehr, James A.; Amonette, William E.

    2009-01-01

    To assess changes in muscular strength and endurance after microgravity exposure, NASA measures isokinetic strength and endurance across multiple sessions before and after long-duration space flight. Accurate interpretation of pre- and post-flight measures depends upon the reliability of each measure. The purpose of this study was to evaluate the test-retest reliability of the NASA International Space Station (ISS) isokinetic protocol. Twenty-four healthy subjects (12 M/12 F, 32.0 +/- 5.6 years) volunteered to participate. Isokinetic knee, ankle, and trunk flexion and extension strength as well as endurance of the knee flexors and extensors were measured using a Cybex NORM isokinetic dynamometer. The first weekly session was considered a familiarization session. Data were collected and analyzed for weeks 2-4. Repeated measures analysis of variance (alpha=0.05) was used to identify weekly differences in isokinetic measures. Test-retest reliability was evaluated by intraclass correlation coefficients (ICC) (3,1). No significant differences were found between weeks in any of the strength measures and the reliability of the strength measures were all considered excellent (ICC greater than 0.9), except for concentric ankle dorsi-flexion (ICC=0.67). Although a significant difference was noted in weekly endurance measures of knee extension (p less than 0.01), the reliability of endurance measure by week were considered excellent for knee flexion (ICC=0.97) and knee extension (ICC=0.96). Except for concentric ankle dorsi-flexion, the isokinetic strength and endurance measures are highly reliable when following the NASA ISS protocol. This protocol should allow accurate interpretation isokinetic data even with a small number of crew members.

  5. Spinal appearance questionnaire: factor analysis, scoring, reliability, and validity testing.

    Science.gov (United States)

    Carreon, Leah Y; Sanders, James O; Polly, David W; Sucato, Daniel J; Parent, Stefan; Roy-Beaudry, Marjolaine; Hopkins, Jeffrey; McClung, Anna; Bratcher, Kelly R; Diamond, Beverly E

    2011-08-15

    Cross sectional. This study presents the factor analysis of the Spinal Appearance Questionnaire (SAQ) and its psychometric properties. Although the SAQ has been administered to a large sample of patients with adolescent idiopathic scoliosis (AIS) treated surgically, its psychometric properties have not been fully evaluated. This study presents the factor analysis and scoring of the SAQ and evaluates its psychometric properties. The SAQ and the Scoliosis Research Society-22 (SRS-22) were administered to AIS patients who were being observed, braced or scheduled for surgery. Standard demographic data and radiographic measures including Lenke type and curve magnitude were also collected. Of the 1802 patients, 83% were female; with a mean age of 14.8 years and mean initial Cobb angle of 55.8° (range, 0°-123°). From the 32 items of the SAQ, 15 loaded on two factors with consistent and significant correlations across all Lenke types. There is an Appearance (items 1-10) and an Expectations factor (items 12-15). Responses are summed giving a range of 5 to 50 for the Appearance domain and 5 to 20 for the Expectations domain. The Cronbach's α was 0.88 for both domains and Total score with a test-retest reliability of 0.81 for Appearance and 0.91 for Expectations. Correlations with major curve magnitude were higher for the SAQ Appearance and SAQ Total scores compared to correlations between the SRS Appearance and SRS Total scores. The SAQ and SRS-22 Scores were statistically significantly different in patients who were scheduled for surgery compared to those who were observed or braced. The SAQ is a valid measure of self-image in patients with AIS with greater correlation to curve magnitude than SRS Appearance and Total score. It also discriminates between patients who require surgery from those who do not.

  6. High gradient test of X-band accelerating structure at GLCTA

    International Nuclear Information System (INIS)

    Watanabe, K.; Higo, T.; Hayano, H.; Terunuma, N.; Saeki, T.; Kudo, N.; Sanuki, T.; Seuhara, T.

    2004-01-01

    GLCTA (Global Linear Collider Test Accelerator) is the high power test facility for X-band acceleration. We have installed an X-band 60cm structure in April 2004 and have been processing it for more than 3 months. Now it is under test on long-term operation. We report here the installation process and high power test result to date. (author)

  7. The reliability of knee joint position testing using electrogoniometry

    Directory of Open Access Journals (Sweden)

    Winter Adele

    2008-01-01

    Full Text Available Abstract Background The current investigation examined the inter- and intra-tester reliability of knee joint angle measurements using a flexible Penny and Giles Biometric® electrogoniometer. The clinical utility of electrogoniometry was also addressed. Methods The first study examined the inter- and intra-tester reliability of measurements of knee joint angles in supine, sitting and standing in 35 healthy adults. The second study evaluated inter-tester and intra-tester reliability of knee joint angle measurements in standing and after walking 10 metres in 20 healthy adults, using an enhanced measurement protocol with a more detailed electrogoniometer attachment procedure. Both inter-tester reliability studies involved two testers. Results In the first study, inter-tester reliability (ICC[2,10] ranged from 0.58–0.71 in supine, 0.68–0.79 in sitting and 0.57–0.80 in standing. The standard error of measurement between testers was less than 3.55° and the limits of agreement ranged from -12.51° to 12.21°. Reliability coefficients for intra-tester reliability (ICC[3,10] ranged from 0.75–0.76 in supine, 0.86–0.87 in sitting and 0.87–0.88 in standing. The standard error of measurement for repeated measures by the same tester was less than 1.7° and the limits of agreement ranged from -8.13° to 7.90°. The second study showed that using a more detailed electrogoniometer attachment protocol reduced the error of measurement between testers to 0.5°. Conclusion Using a standardised protocol, reliable measures of knee joint angles can be gained in standing, supine and sitting by using a flexible goniometer.

  8. Reliability of candida skin test in the evaluation of T-cell function in ...

    African Journals Online (AJOL)

    Ehab

    2017-01-23

    Jan 23, 2017 ... considered generally reliable under the age of 1 year.6 ... We sought to investigate the reliability of manually ... Conclusion: Candida intradermal test is a cost- effective ..... Ballow M. Historical perspectives in the diagnosis.

  9. Applications of majorization and Schur functions in reliability and life testing

    International Nuclear Information System (INIS)

    Proschan, F.

    1975-01-01

    This is an expository paper presenting basic definitions and properties of majorization and Schur functions, and displaying a variety of applications of these concepts in reliability prediction and modelling, and in reliability inference and life testing

  10. Enhancing reliability of ultrasonic testing of welds of nuclear power plant equipment

    International Nuclear Information System (INIS)

    Shcherbinskij, V.G.

    1981-01-01

    Results of investigation of factors influencing the reliability of manual ultrasonic testing of welded joints and weld deposited metal power-generating equipment are presented. Recommendations on the enhancing of reliability are given [ru

  11. The control computer for the Chalk River electron test accelerator

    International Nuclear Information System (INIS)

    McMichael, G.E.; Fraser, J.S.; McKeown, J.

    1978-02-01

    A versatile control and data acquisition system has been developed for a modest-sized linear accelerator using mainly process I/O hardware and software. This report describes the evolution of the present system since 1972, the modifications needed to satisfy the changing requirements of the various accelerator physics experiments and the limitations of such a system in process control. (author)

  12. Validity and test-retest reliability of a novel simple back extensor muscle strength test.

    Science.gov (United States)

    Harding, Amy T; Weeks, Benjamin Kurt; Horan, Sean A; Little, Andrew; Watson, Steven L; Beck, Belinda Ruth

    2017-01-01

    To develop and determine convergent validity and reliability of a simple and inexpensive clinical test to quantify back extensor muscle strength. Two testing sessions were conducted, 7 days apart. Each session involved three trials of standing maximal isometric back extensor muscle strength using both the novel test and isokinetic dynamometry. Lumbar spine bone mineral density was examined by dual-energy X-ray absorptiometry. Validation was examined with Pearson correlations ( r ). Test-retest reliability was examined with intraclass correlation coefficients and limits of agreement. Pearson correlations and intraclass correlation coefficients are presented with corresponding 95% confidence intervals. Linear regression was used to examine the ability of peak back extensor muscle strength to predict indices of lumbar spine bone mineral density and strength. A total of 52 healthy adults (26 men, 26 women) aged 46.4 ± 20.4 years were recruited from the community. A strong positive relationship was observed between peak back extensor strength from hand-held and isokinetic dynamometry ( r  = 0.824, p  strength test, short- and long-term reliability was excellent (intraclass correlation coefficient = 0.983 (95% confidence interval, 0.971-0.990), p  strength measures with the novel back extensor strength protocol were -6.63 to 7.70 kg, with a mean bias of +0.71 kg. Back extensor strength predicted 11% of variance in lumbar spine bone mineral density ( p  strength ( p  strength is quick, relatively inexpensive, and reliable; demonstrates initial convergent validity in a healthy population; and is associated with bone mass at a clinically important site.

  13. Adjoint sensitivity analysis procedure of Markov chains with applications on reliability of IFMIF accelerator-system facilities

    Energy Technology Data Exchange (ETDEWEB)

    Balan, I.

    2005-05-01

    This work presents the implementation of the Adjoint Sensitivity Analysis Procedure (ASAP) for the Continuous Time, Discrete Space Markov chains (CTMC), as an alternative to the other computational expensive methods. In order to develop this procedure as an end product in reliability studies, the reliability of the physical systems is analyzed using a coupled Fault-Tree - Markov chain technique, i.e. the abstraction of the physical system is performed using as the high level interface the Fault-Tree and afterwards this one is automatically converted into a Markov chain. The resulting differential equations based on the Markov chain model are solved in order to evaluate the system reliability. Further sensitivity analyses using ASAP applied to CTMC equations are performed to study the influence of uncertainties in input data to the reliability measures and to get the confidence in the final reliability results. The methods to generate the Markov chain and the ASAP for the Markov chain equations have been implemented into the new computer code system QUEFT/MARKOMAGS/MCADJSEN for reliability and sensitivity analysis of physical systems. The validation of this code system has been carried out by using simple problems for which analytical solutions can be obtained. Typical sensitivity results show that the numerical solution using ASAP is robust, stable and accurate. The method and the code system developed during this work can be used further as an efficient and flexible tool to evaluate the sensitivities of reliability measures for any physical system analyzed using the Markov chain. Reliability and sensitivity analyses using these methods have been performed during this work for the IFMIF Accelerator System Facilities. The reliability studies using Markov chain have been concentrated around the availability of the main subsystems of this complex physical system for a typical mission time. The sensitivity studies for two typical responses using ASAP have been

  14. High Pressure Hydrogen Pressure Relief Devices: Accelerated Life Testing and Application Best Practices

    Energy Technology Data Exchange (ETDEWEB)

    Burgess, Robert M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Post, Matthew B. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Buttner, William J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rivkin, Carl H. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-11-06

    Pressure relief devices (PRDs ) are used to protect high pressure systems from burst failure caused by overpressurization. Codes and standards require the use of PRDs for the safe design of many pressurized systems. These systems require high reliability due to the risks associated with a burst failure. Hydrogen service can increase the risk of PRD failure due to material property degradation caused by hydrogen attack. The National Renewable Energy Laboratory (NREL) has conducted an accelerated life test on a conventional spring loaded PRD. Based on previous failures in the field, the nozzles specific to these PRDs are of particular interest. A nozzle in a PRD is a small part that directs the flow of fluid toward the sealing surface to maintain the open state of the valve once the spring force is overcome. The nozzle in this specific PRD is subjected to the full tensile force of the fluid pressure. These nozzles are made from 440C material, which is a type of hardened steel that is commonly chosen for high pressure applications because of its high strength properties. In a hydrogen environment, however, 440C is considered a worst case material since hydrogen attack results in a loss of almost all ductility and thus 440C is prone to fatigue and material failure. Accordingly, 440C is not recommended for hydrogen service. Conducting an accelerated life test on a PRD with 440C material provides information on necessary and sufficient conditions required to produce crack initiation and failure. The accelerated life test also provides information on other PRD failure modes that are somewhat statistically random in nature.

  15. LeRC rail accelerators: test designs and diagnostic techniques

    International Nuclear Information System (INIS)

    Zana, L.M.; Kerslake, W.R.; Sturman, J.C.; Wang, S.Y.; Terdan, F.F.

    1984-01-01

    The feasibility of using rail accelerators for various in-space and to-space propulsion applications was investigated. A 1 meter, 24 sq mm bore accelerator was designed with the goal of demonstrating projectile velocities of 15 km/sec using a peak current of 200 kA. A second rail accelerator, 1 meter long with a 156.25 sq mm bore, was designed with clear polycarbonate sidewalls to permit visual observation of the plasma arc. A study of available diagnostic techniques and their application to the rail accelerator is presented. Specific topics of discussion include the use of interferometry and spectroscopy to examine the plasma armature as well as the use of optical sensors to measure rail displacement during acceleration. Standard diagnostics such as current and voltage measurements are also discussed. 15 references

  16. Radiation testing of thick-wall objects using a linear accelerator or Co-60

    International Nuclear Information System (INIS)

    Depending on the energy required, a 60 Co source or various types of betatrons and linear accelerators may be used for radiation testing of thick-walled metal parts. While 60 Co sources are easily transported, accelerators are not, but a transportable linear accelerator is described

  17. Criterion validity and reliability of a smartphone delivered sub-maximal fitness test for people with type 2 diabetes

    DEFF Research Database (Denmark)

    Brinklov, Cecilie Fau; Thorsen, Ida Kær; Karstoft, Kristian

    2016-01-01

    Background: Prevention of multi-morbidities following non-communicable diseases requires a systematic registration of adverse modifiable risk factors, including low physical fitness. The aim of the study was to establish criterion validity and reliability of a smartphone app (InterWalk) delivered....... The algorithm was validated using leave-one-out cross validation. Test-retest reliability was tested in a subset of participants (N = 10). Results: The overall VO2peak prediction of the algorithm (R2) was 0.60 and 0.45 when the smartphone was placed in the pockets of the pants and jacket, respectively (p ... calorimetry and the acceleration (vector magnitude) from the smartphone was obtained. The vector magnitude was used to predict VO2peak along with the co-variates weight, height and sex. The validity of the algorithm was tested when the smartphone was placed in the right pocket of the pants or jacket...

  18. The navicular position test - a reliable measure of the navicular bone position during rest and loading

    DEFF Research Database (Denmark)

    Spörndly-Nees, Søren; Dåsberg, Brian; Nielsen, Rasmus Oestergaard

    2011-01-01

    .08 degrees, ICC = 0.91. Discussion: The present data support The Navicular Position Test as a reliable test of the navicular bone position during rest and loading measured in a simple test set-up. Conclusion: The Navicular Position Test was shown to have a high intraday-, intra- and inter-tester reliability...

  19. Reliability of the Test of Integrated Language and Literacy Skills (TILLS)

    Science.gov (United States)

    Mailend, Marja-Liisa; Plante, Elena; Anderson, Michele A.; Applegate, E. Brooks; Nelson, Nickola W.

    2016-01-01

    Background: As new standardized tests become commercially available, it is critical that clinicians have access to the information about a test's psychometric properties, including aspects of reliability. Aims: The purpose of the three studies reported in this article was to investigate the reliability of a new test, the Test of Integrated…

  20. Feasibility and Reliability of Physical Fitness Tests in Older Adults with Intellectual Disability: A Pilot Study

    Science.gov (United States)

    Hilgenkamp, Thessa I. M.; van Wijck, Ruud; Evenhuis, Heleen M.

    2012-01-01

    Background: Physical fitness is relevant for wellbeing and health, but knowledge on the feasibility and reliability of instruments to measure physical fitness for older adults with intellectual disability is lacking. Methods: Feasibility and test-retest reliability of a physical fitness test battery (Box and Block Test, Response Time Test, walking…

  1. 75 FR 50853 - Special Conditions: Cirrus Design Corporation Model SF50 Airplane; Function and Reliability Testing

    Science.gov (United States)

    2010-08-18

    ... airplanes. 1. Function and Reliability Testing. Flight tests: In place of 14 CFR 21.35(b)(2), the following...; Function and Reliability Testing AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final special... to CAR part 3 became effective January 15, 1951, and deleted the service test requirements in Section...

  2. 75 FR 29962 - Special Conditions: Cirrus Design Corporation Model SF50 Airplane; Function and Reliability Testing

    Science.gov (United States)

    2010-05-28

    ... SF50 airplanes. 1. Function and Reliability Testing Flight tests: In place of 14 CFR part 21.35(b)(2... Reliability Testing AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice of proposed special..., 1951, and deleted the service test requirements in Section 3.19 for airplanes of 6,000 pounds maximum...

  3. An accelerated exposure and testing apparatus for building joint sealants.

    Science.gov (United States)

    White, C C; Hunston, D L; Tan, K T; Hettenhouser, J; Garver, J D

    2013-09-01

    The design, fabrication, and implementation of a computer-controlled exposure and testing apparatus for building joint sealants are described in this paper. This apparatus is unique in its ability to independently control and monitor temperature, relative humidity, ultraviolet (UV) radiation, and mechanical deformation. Each of these environmental factors can be controlled precisely over a wide range of conditions during periods of a month or more. Moreover, as controlled mechanical deformations can be generated, in situ mechanical characterization tests can be performed without removing specimens from the chamber. Temperature and humidity were controlled during our experiments via a precision temperature regulator and proportional mixing of dry and moisture-saturated air; while highly uniform UV radiation was attained by attaching the chamber to an integrating sphere-based radiation source. A computer-controlled stepper motor and a transmission system were used to provide precise movement control. The reliability and effectiveness of the apparatus were demonstrated on a model sealant material. The results clearly show that this apparatus provides an excellent platform to study the long-term durability of building joint sealants.

  4. Demonstration recommendations for accelerated testing of concrete decontamination methods

    Energy Technology Data Exchange (ETDEWEB)

    Dickerson, K.S.; Ally, M.R.; Brown, C.H.; Morris, M.I.; Wilson-Nichols, M.J.

    1995-12-01

    A large number of aging US Department of Energy (DOE) surplus facilities located throughout the US require deactivation, decontamination, and decommissioning. Although several technologies are available commercially for concrete decontamination, emerging technologies with potential to reduce secondary waste and minimize the impact and risk to workers and the environment are needed. In response to these needs, the Accelerated Testing of Concrete Decontamination Methods project team described the nature and extent of contaminated concrete within the DOE complex and identified applicable emerging technologies. Existing information used to describe the nature and extent of contaminated concrete indicates that the most frequently occurring radiological contaminants are {sup 137}Cs, {sup 238}U (and its daughters), {sup 60}Co, {sup 90}Sr, and tritium. The total area of radionuclide-contaminated concrete within the DOE complex is estimated to be in the range of 7.9 {times} 10{sup 8} ft{sup 2}or approximately 18,000 acres. Concrete decontamination problems were matched with emerging technologies to recommend demonstrations considered to provide the most benefit to decontamination of concrete within the DOE complex. Emerging technologies with the most potential benefit were biological decontamination, electro-hydraulic scabbling, electrokinetics, and microwave scabbling.

  5. Demonstration recommendations for accelerated testing of concrete decontamination methods

    International Nuclear Information System (INIS)

    Dickerson, K.S.; Ally, M.R.; Brown, C.H.; Morris, M.I.; Wilson-Nichols, M.J.

    1995-12-01

    A large number of aging US Department of Energy (DOE) surplus facilities located throughout the US require deactivation, decontamination, and decommissioning. Although several technologies are available commercially for concrete decontamination, emerging technologies with potential to reduce secondary waste and minimize the impact and risk to workers and the environment are needed. In response to these needs, the Accelerated Testing of Concrete Decontamination Methods project team described the nature and extent of contaminated concrete within the DOE complex and identified applicable emerging technologies. Existing information used to describe the nature and extent of contaminated concrete indicates that the most frequently occurring radiological contaminants are 137 Cs, 238 U (and its daughters), 60 Co, 90 Sr, and tritium. The total area of radionuclide-contaminated concrete within the DOE complex is estimated to be in the range of 7.9 x 10 8 ft 2 or approximately 18,000 acres. Concrete decontamination problems were matched with emerging technologies to recommend demonstrations considered to provide the most benefit to decontamination of concrete within the DOE complex. Emerging technologies with the most potential benefit were biological decontamination, electro-hydraulic scabbling, electrokinetics, and microwave scabbling

  6. Test-retest Agreement and Reliability of Quantitative Sensory Testing 1 Year After Breast Cancer Surgery

    DEFF Research Database (Denmark)

    Andersen, Kenneth Geving; Kehlet, Henrik; Aasvang, Eske Kvanner

    2015-01-01

    .5 SD) than within-patient variation (0.23 to 3.55 SD). There were no significant differences between pain and pain-free patients. The individual test-retest variability was higher on the operated side compared with the nonoperated side. DISCUSSION: The QST protocol reliability allows for group......OBJECTIVES: Quantitative sensory testing (QST) is used to assess sensory dysfunction and nerve damage by examining psychophysical responses to controlled, graded stimuli such as mechanical and thermal detection and pain thresholds. In the breast cancer population, 4 studies have used QST to examine...... persistent pain after breast cancer treatment, suggesting neuropathic pain being a prominent pain mechanism. However, the agreement and reliability of QST has not been described in the postsurgical breast cancer population, hindering exact interpretation of QST studies in this population. The aim...

  7. Some questions of the technique of high-voltage testing of accele-- rating tube space in electrostatic accelerators

    International Nuclear Information System (INIS)

    Romanov, V.A.; Ivanov, V.V.; Mukhametshin, V.I.; Dmitriev, E.P.; Kidalov, A.I.

    1983-01-01

    In the course of high-voltage testing of accelerating spaces a wide spread of experimental values of electric strength is observed. This circumstance is determined by a number of factors one of which is the technique used for high-voltage testing. For the purpose of obtaining more reliable experimental data on electric strength of accelerating spaces it is suggested to take for a criterion of electric strength of an accelerating space in long accelerating tubes a long-time withstood voltage which is equal approximately to a doubled working space voltage obtained as a result of a smooth voltage rise at dark current density not exceeding (1...5)x10 -2 A/cm 2 . In the course of testing of accelerating spaces of 25 mm height with total working area of electrodes approximately 360 cm 2 and insulator area onto vacuum approximately 150 cm 2 a long-time 70 kV voltage with dark current less than 1.10 -8 A is obtained

  8. Reliability Testing Beyond Qualification as a Key Component in Photovoltaic's Progress Toward Grid Parity: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wohlgemuth, J. H.; Kurtz, S.

    2011-02-01

    This paper discusses why it is necessary for new lower cost PV modules to be tested using a reliability test sequence that goes beyond the Qualification test sequence now utilized for modules. Today most PV modules are warranted for 25 years, but the Qualification Test Sequence does not test for 25-year life. There is no accepted test protocol to validate a 25-year lifetime. This paper recommends the use of long term accelerated testing to compare now designs directly with older designs that have achieved long lifetimes in outdoor exposure. If the new designs do as well or better than the older ones, then it is likely that they will survive an equivalent length of time in the field.

  9. Testing the reliability of information extracted from ancient zircon

    Science.gov (United States)

    Kielman, Ross; Whitehouse, Martin; Nemchin, Alexander

    2015-04-01

    Studies combining zircon U-Pb chronology, trace element distribution as well as O and Hf isotope systematics are a powerful way to gain understanding of the processes shaping Earth's evolution, especially in detrital populations where constraints from the original host are missing. Such studies of the Hadean detrital zircon population abundant in sedimentary rocks in Western Australia have involved analysis of an unusually large number of individual grains, but also highlighted potential problems with the approach, only apparent when multiple analyses are obtained from individual grains. A common feature of the Hadean as well as many early Archaean zircon populations is their apparent inhomogeneity, which reduces confidence in conclusions based on studies combining chemistry and isotopic characteristics of zircon. In order to test the reliability of information extracted from early Earth zircon, we report results from one of the first in-depth multi-method study of zircon from a relatively simple early Archean magmatic rock, used as an analogue to ancient detrital zircon. The approach involves making multiple SIMS analyses in individual grains in order to be comparable to the most advanced studies of detrital zircon populations. The investigated sample is a relatively undeformed, non-migmatitic ca. 3.8 Ga tonalite collected a few kms south of the Isua Greenstone Belt, southwest Greenland. Extracted zircon grains can be combined into three different groups based on the behavior of their U-Pb systems: (i) grains that show internally consistent and concordant ages and define an average age of 3805±15 Ma, taken to be the age of the rock, (ii) grains that are distributed close to the concordia line, but with significant variability between multiple analyses, suggesting an ancient Pb loss and (iii) grains that have multiple analyses distributed along a discordia pointing towards a zero intercept, indicating geologically recent Pb-loss. This overall behavior has

  10. U.S. advanced accelerator applications program: plans to develop and test waste transmutation technologies

    International Nuclear Information System (INIS)

    Van Tuyle, G.; Bennett, D.; Arthur, E.; Cappiello, M.; Finck, P.; Hill, D.; Herczeg, J.; Goldner, F.

    2001-01-01

    The primary mission of the U.S. Advanced Accelerator Applications (AAA) Program is to establish a national nuclear technology research capability that can demonstrate accelerator-based transmutation of waste and conduct transmutation research while at the same time providing a capability for the production of tritium if required. The AAA Program was created during fiscal year 2001 from the Accelerator Transmutation of Waste (ATW) Program and the Accelerator Production of Tritium (APT) Project. This paper describes the new AAA Program, as well as its two major components: development and testing of waste transmutation technologies and construction of an integrated accelerator-driven test facility (ADTF). (author)

  11. "Graded Cycling Test with Talk Test" Is a Reliable Test to Monitor Cardiovascular Fitness in Patients with Minor Stroke

    DEFF Research Database (Denmark)

    Steen Krawcyk, Rikke; Vinther, Anders; Caesar Petersen, Nicolas

    2017-01-01

    variability may challenge currently used cardiovascular monitoring. The Graded Cycling Test with Talk Test is a submaximal exercise test independent of heart rate variability, shown reliable for patients with cardiac disease. METHODS: Patients diagnosed with lacunar stroke according to TOAST (Trial of Org...... a minor measurement error: 12.9 W for groups of patients (standard error of measurement, SEM95) and 18.3 W for individual patients (smallest real difference). CONCLUSION: The "Graded Cycling Test with Talk Test" is feasible and reliable for monitoring exercise effects in patients with lacunar stroke...... 10172 in Acute Stroke Treatment) criteria performed an incremental exercise test on a stationary bicycle with a 15 W (watt) increase in workload every minute. Toward the end of each incremental step, the patients recited a standardized text passage and subsequently were asked: "Are you still able...

  12. Operational status of the Brookhaven National Laboratory Accelerator Test Facility

    International Nuclear Information System (INIS)

    Batchelor, K.; Ben-Zvi, I.; Fernow, R.C.; Fischer, A.S.; Gallardo, J.; Jialin, Xie; Kirk, H.G.; Malone, R.G.; Parsa, Z.; Palmer, R.B.; Rao, T.; Rogers, J.; Sheehan, J.; Tsang, T.Y.F.; Ulc, S.; van Steenbergen, A.; Woodle, M.; Zhang, R.S.; Bigio, I.; Kurnit, N.; Shimada, T.; McDonald, K.T.; Russel, D.P.; Jiang, Z.Y.; Pellegrini, C.; Wang, X.J.

    1990-01-01

    Initial design parameters and early operational results of a 50 MeV high brightness electron linear accelerator are described. The system utilizes a radio frequency electron gun operating at a frequency of 2.856 GHz and a nominal output energy of 4.5 MeV followed by two, 2π/3 mode, disc loaded, traveling wave accelerating sections. The gun cathode is photo excited with short (6 psec) laser pulses giving design peak currents of a few hundred amperes. The system will be utilized to carry out infra-red FEL studies and investigation of new high gradient accelerating structures

  13. Accelerated Bearing Life-time Test Rig Development for Low Speed Data Acquisition

    Directory of Open Access Journals (Sweden)

    Andreas Klausen

    2017-07-01

    Full Text Available Condition monitoring plays an important role in rotating machinery to ensure reliability of the equipment, and to detect fault conditions at an early stage. Although health monitoring methodologies have been thoroughly developed for rotating machinery, low-speed conditions often pose a challenge due to the low signal-to-noise ratio. To this aim, sophisticated algorithms that reduce noise and highlight the bearing faults are necessary to accurately diagnose machines undergoing this condition. In the development phase, sensor data from a healthy and damaged bearing rotating at low-speed is required to verify the performance of such algorithms. A test rig for performing accelerated life-time testing of small rolling element bearings is designed to collect necessary sensor data. Heavy loads at high-speed conditions are applied to the test bearing to wear it out fast. Sensor data is collected in intervals during the test to capture the degeneration features. The main objective of this paper is to provide a detailed overview for the development and analysis of this test rig. A case study with experimental vibration data is also presented to illustrate the efficacy of the developed test rig.

  14. Reliability engineering

    International Nuclear Information System (INIS)

    Lee, Chi Woo; Kim, Sun Jin; Lee, Seung Woo; Jeong, Sang Yeong

    1993-08-01

    This book start what is reliability? such as origin of reliability problems, definition of reliability and reliability and use of reliability. It also deals with probability and calculation of reliability, reliability function and failure rate, probability distribution of reliability, assumption of MTBF, process of probability distribution, down time, maintainability and availability, break down maintenance and preventive maintenance design of reliability, design of reliability for prediction and statistics, reliability test, reliability data and design and management of reliability.

  15. Improving QST Reliability – More Raters, Tests or Occasions? A Multivariate Generalizability Study

    DEFF Research Database (Denmark)

    O'Neill, Søren; O'Neill, Lotte

    2015-01-01

    The reliability of quantitative sensory testing (QST) is affected by the error attributable to both test occasion and rater (examiner) as well as interactions between them. Most reliability studies only account for one source of error. The present study employed a fully-crossed, multivariate...... threshold, intensity, tolerance and modulation with mechanical, thermal and chemical stimuli. The classical test-retest and inter-rater reliability (0.19... procedures. Reliability was improved more by repeated testing on separate occasions opposed to repeated testing by different raters....

  16. Development and reliability testing of a food store observation form.

    Science.gov (United States)

    Rimkus, Leah; Powell, Lisa M; Zenk, Shannon N; Han, Euna; Ohri-Vachaspati, Punam; Pugach, Oksana; Barker, Dianne C; Resnick, Elissa A; Quinn, Christopher M; Myllyluoma, Jaana; Chaloupka, Frank J

    2013-01-01

    To develop a reliable food store observational data collection instrument to be used for measuring product availability, pricing, and promotion. Observational data collection. A total of 120 food stores (26 supermarkets, 34 grocery stores, 54 gas/convenience stores, and 6 mass merchandise stores) in the Chicago metropolitan statistical area. Inter-rater reliability for product availability, pricing, and promotion measures on a food store observational data collection instrument. Cohen's kappa coefficient and proportion of overall agreement for dichotomous variables and intra-class correlation coefficient for continuous variables. Inter-rater reliability, as measured by average kappa coefficient, was 0.84 for food and beverage product availability measures, 0.80 for interior store characteristics, and 0.70 for exterior store characteristics. For continuous measures, average intra-class correlation coefficient was 0.82 for product pricing measures; 0.90 for counts of fresh, frozen, and canned fruit and vegetable options; and 0.85 for counts of advertisements on the store exterior and property. The vast majority of measures demonstrated substantial or almost perfect agreement. Although some items may require revision, results suggest that the instrument may be used to reliably measure the food store environment. Copyright © 2013 Society for Nutrition Education and Behavior. Published by Elsevier Inc. All rights reserved.

  17. Reliability, construct and discriminative validity of clinical testing in subjects with and without chronic neck pain

    DEFF Research Database (Denmark)

    Jørgensen, René; Ris Hansen, Inge; Falla, Deborah

    2014-01-01

    -retest reliability in people with and without chronic neck pain. Moreover, construct and between-group discriminative validity of the tests were examined. METHODS: Twenty-one participants with chronic neck pain and 21 asymptomatic participants were included. Intra- and inter-reliability were evaluated for the Cranio-Cervical...... Flexion Test (CCFT), Range of Movement (ROM), Joint Position Error (JPE), Gaze Stability (GS), Smooth Pursuit Neck Torsion Test (SPNTT), and neuromuscular control of the Deep Cervical Extensors (DCE). Test-retest reliability was assessed for Postural Control (SWAY) and Pressure Pain Threshold (PPT) over......BACKGROUND: The reliability of clinical tests for the cervical spine has not been adequately evaluated. Six cervical clinical tests, which are low cost and easy to perform in clinical settings, were tested for intra- and inter-examiner reliability, and two performance tests were assessed for test...

  18. Accelerated stability testing of organic photovoltaics using concentrated sunlight

    DEFF Research Database (Denmark)

    Katz, Eugene A.; Manor, Assaf; Mescheloff, Asaf

    2012-01-01

    We suggest to use concentrated sunlight for accelerated studies of light-induced mechanisms in the degradation of organic photovoltaics (OPV) based on the polymer (P3HT)/fullerene (PCBM) bulk heterojunctions. Two particular cases of the degradation are reported.......We suggest to use concentrated sunlight for accelerated studies of light-induced mechanisms in the degradation of organic photovoltaics (OPV) based on the polymer (P3HT)/fullerene (PCBM) bulk heterojunctions. Two particular cases of the degradation are reported....

  19. Test of understanding of vectors: A reliable multiple-choice vector concept test

    Science.gov (United States)

    Barniol, Pablo; Zavala, Genaro

    2014-06-01

    In this article we discuss the findings of our research on students' understanding of vector concepts in problems without physical context. First, we develop a complete taxonomy of the most frequent errors made by university students when learning vector concepts. This study is based on the results of several test administrations of open-ended problems in which a total of 2067 students participated. Using this taxonomy, we then designed a 20-item multiple-choice test [Test of understanding of vectors (TUV)] and administered it in English to 423 students who were completing the required sequence of introductory physics courses at a large private Mexican university. We evaluated the test's content validity, reliability, and discriminatory power. The results indicate that the TUV is a reliable assessment tool. We also conducted a detailed analysis of the students' understanding of the vector concepts evaluated in the test. The TUV is included in the Supplemental Material as a resource for other researchers studying vector learning, as well as instructors teaching the material.

  20. The timed "up and go" test : Reliability and validity in persons with unilateral lower limb amputation

    NARCIS (Netherlands)

    Schoppen, Tanneke; Boonstra, Antje; Groothoff, JW; de Vries, J; Goeken, LNH; Eisma, Willem

    Objective: To determine the interrater and interrater reliability and the validity of the Timed "up and go" test as a measure for physical mobility in elderly patients with an amputation of the lower extremity. Design: To test interrater reliability, the test was performed for two observers at

  1. Validity and reliability of tests determining performance-related components of wheelchair basketball

    NARCIS (Netherlands)

    de Groot, Sonja; Balvers, Inge J.M.; Kouwenhoven, Sanne M.; Janssen, Thomas W.J.

    The purpose of this study was to investigate the reliability and validity of wheelchair basketball field tests. Nineteen wheelchair basketball players performed 10 test items twice to determine the reliability. The validity of the tests was assessed by relating the scores to the players'

  2. Validity and reliability of tests determining performance-related components of wheelchair basketball

    NARCIS (Netherlands)

    De Groot, Sonja; Balvers, Inge J. M.; Kouwenhoven, Sanne M.; Janssen, Thomas W. J.

    2012-01-01

    The purpose of this study was to investigate the reliability and validity of wheelchair basketball field tests. Nineteen wheelchair basketball players performed 10 test items twice to determine the reliability. The validity of the tests was assessed by relating the scores to the players'

  3. An Integrated Approach to Establish Validity and Reliability of Reading Tests

    Science.gov (United States)

    Razi, Salim

    2012-01-01

    This study presents the processes of developing and establishing reliability and validity of a reading test by administering an integrative approach as conventional reliability and validity measures superficially reveals the difficulty of a reading test. In this respect, analysing vocabulary frequency of the test is regarded as a more eligible way…

  4. Construction and Evaluation of Reliability and Validity of Reasoning Ability Test

    Science.gov (United States)

    Bhat, Mehraj A.

    2014-01-01

    This paper is based on the construction and evaluation of reliability and validity of reasoning ability test at secondary school students. In this paper an attempt was made to evaluate validity, reliability and to determine the appropriate standards to interpret the results of reasoning ability test. The test includes 45 items to measure six types…

  5. Diagnosis of carpal tunnel syndrome: interobserver reliability of the blinded scratch-collapse test

    NARCIS (Netherlands)

    Blok, Robin D.; Becker, Stéphanie J. E.; Ring, David C.

    2014-01-01

    The reliability of the scratch-collapse test for diagnosis of carpal tunnel syndrome (CTS) has not been tested by independent investigators. This study measured the reliability of the scratch-collapse test comparing the treating hand surgeon and blinded evaluators. We performed a prospective

  6. Accelerated Monte Carlo system reliability analysis through machine-learning-based surrogate models of network connectivity

    International Nuclear Information System (INIS)

    Stern, R.E.; Song, J.; Work, D.B.

    2017-01-01

    The two-terminal reliability problem in system reliability analysis is known to be computationally intractable for large infrastructure graphs. Monte Carlo techniques can estimate the probability of a disconnection between two points in a network by selecting a representative sample of network component failure realizations and determining the source-terminal connectivity of each realization. To reduce the runtime required for the Monte Carlo approximation, this article proposes an approximate framework in which the connectivity check of each sample is estimated using a machine-learning-based classifier. The framework is implemented using both a support vector machine (SVM) and a logistic regression based surrogate model. Numerical experiments are performed on the California gas distribution network using the epicenter and magnitude of the 1989 Loma Prieta earthquake as well as randomly-generated earthquakes. It is shown that the SVM and logistic regression surrogate models are able to predict network connectivity with accuracies of 99% for both methods, and are 1–2 orders of magnitude faster than using a Monte Carlo method with an exact connectivity check. - Highlights: • Surrogate models of network connectivity are developed by machine-learning algorithms. • Developed surrogate models can reduce the runtime required for Monte Carlo simulations. • Support vector machine and logistic regressions are employed to develop surrogate models. • Numerical example of California gas distribution network demonstrate the proposed approach. • The developed models have accuracies 99%, and are 1–2 orders of magnitude faster than MCS.

  7. Utilization and reliability of nondestructive testing in ordnance

    International Nuclear Information System (INIS)

    Maranhao, M.; Alves, L.E.G.

    1983-01-01

    Information about nondestructive testing used in ordnance are presented. For propellants and breaking load ultrasonic testing and X-ray are used. For skyrocket propellants the X-ray is used to test the continuity of the explosive mass and the burn inhibiting agent. For rupture explosive, the X-ray is used to test the continuity of explosive mass. (E.G.) [pt

  8. Life Prediction on a T700 Carbon Fiber Reinforced Cylinder with Limited Accelerated Life Testing Data

    OpenAIRE

    Ma Xiaobing; Zhang Yongbo

    2015-01-01

    An accelerated life testing investigation was conducted on a composite cylinder that consists of aluminum alloy and T700 carbon fiber. The ultimate failure stress predictions of cylinders were obtained by the mixing rule and verified by the blasting static pressure method. Based on the stress prediction of cylinder under working conditions, the constant stress accelerated life test of the cylinder was designed. However, the failure data cannot be sufficiently obtained by the accelerated life ...

  9. TESTING METHODS FOR MECHANICALLY IMPROVED SOILS: RELIABILITY AND VALIDITY

    Directory of Open Access Journals (Sweden)

    Ana Petkovšek

    2017-10-01

    Full Text Available A possibility of in-situ mechanical improvement for reducing the liquefaction potential of silty sands was investigated by using three different techniques: Vibratory Roller Compaction, Rapid Impact Compaction (RIC and Soil Mixing. Material properties at all test sites were investigated before and after improvement with the laboratory and the in situ tests (CPT, SDMT, DPSH B, static and dynamic load plate test, geohydraulic tests. Correlation between the results obtained by different test methods gave inconclusive answers.

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

    International Nuclear Information System (INIS)

    Urakawa, J

    2012-01-01

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

  11. Framework for a Comparative Accelerated Testing Standard for PV Modules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, S.; Wohlgemuth, J.; Yamamichi, M.; Sample, T.; Miller, D.; Meakin, D.; Monokroussos, C.; TamizhMani, M.; Kempe, M.; Jordan, D.; Bosco, N.; Hacke, P.; Bermudez, V.; Kondo, M.

    2013-08-01

    As the photovoltaic industry has grown, the interest in comparative accelerated testing has also grown. Private test labs offer testing services that apply greater stress than the standard qualification tests as tools for differentiating products and for gaining increased confidence in long-term PV investments. While the value of a single international standard for comparative accelerated testing is widely acknowledged, the development of a consensus is difficult. This paper strives to identify a technical basis for a comparative standard.

  12. Failure rates for accelerated acceptance testing of silicon transistors

    Science.gov (United States)

    Toye, C. R.

    1968-01-01

    Extrapolation tables for the control of silicon transistor product reliability have been compiled. The tables are based on a version of the Arrhenius statistical relation and are intended to be used for low- and medium-power silicon transistors.

  13. Experimental test accelerator: description and results of initial experiments

    International Nuclear Information System (INIS)

    Fessenden, T.; Birx, D.; Briggs, R.

    1980-01-01

    The ETA is a high current (10,000 Amp) linear induction accelerator that produces short (30 ns) pulses of electrons at 5 MeV twice per second or in bursts of 5 pulses separated by as little as one millisecond. At this time the machine has operated at 65% of its design current and 90% of the design voltage. This report contains a description of the accelerator and its diagnostics; the results of the initial year of operation; a comparison of design codes with experiments on beam transport; and a discussion of some of the special problems and their status

  14. Specifications, quality control, manufacturing, and testing of accelerator magnets

    CERN Document Server

    Einfeld, D

    2010-01-01

    The performance of the magnets plays an important role in the functioning of an accelerator. Most of the magnets are designed at the accelerator laboratory and built by industry. The link between the laboratory and the manufacturer is the contract containing the Technical Specifications of the magnets. For an overview of the contents of the Technical Specifications, the specifications for the magnets of ALBA (bending, quadrupole, and sextupole) are described in this paper. The basic rules of magnet design are reviewed in Appendix A.

  15. Test-retest reliability and task order effects of emotional cognitive tests in healthy subjects.

    Science.gov (United States)

    Adams, Thomas; Pounder, Zoe; Preston, Sally; Hanson, Andy; Gallagher, Peter; Harmer, Catherine J; McAllister-Williams, R Hamish

    2016-11-01

    Little is known of the retest reliability of emotional cognitive tasks or the impact of using different tasks employing similar emotional stimuli within a battery. We investigated this in healthy subjects. We found improved overall performance in an emotional attentional blink task (EABT) with repeat testing at one hour and one week compared to baseline, but the impact of an emotional stimulus on performance was unchanged. Similarly, performance on a facial expression recognition task (FERT) was better one week after a baseline test, though the relative effect of specific emotions was unaltered. There was no effect of repeat testing on an emotional word categorising, recall and recognition task. We found no difference in performance in the FERT and EABT irrespective of task order. We concluded that it is possible to use emotional cognitive tasks in longitudinal studies and combine tasks using emotional facial stimuli in a single battery.

  16. RELIABILITY OF CERTAIN TESTS FOR EVALUATION OF JUDO TECHNIQUES

    Directory of Open Access Journals (Sweden)

    Slavko Obadov

    2007-05-01

    Full Text Available The sample included 106 judokas. Assessment of the level of mastership of judo techniques was carried out by evaluation of fi ve competent studies. Each subject performed a technique three times and each performance was evaluated by the judges. In order to evaluate measurement of each technique, Cronbach’s coeffi cient of reliability  was calculated. During the procedure the subjects's results were also transformed to factor scores i.e. the results of each performer at the main component of evaluation in the fi ve studies. These factor scores could be used in the subsequent procedure of multivariant statistical analysis.

  17. Online cognition : Factors facilitating reliable online neuropsychological test results

    NARCIS (Netherlands)

    Feenstra, H.E.M.; Vermeulen, I.E.; Murre, J.M.J.; Schagen, S.B.

    2017-01-01

    OBJECTIVE: Online neuropsychological test batteries could allow for large-scale cognitive data collection in clinical studies. However, the few online neuropsychological test batteries that are currently available often still require supervision or lack proper psychometric evaluation. In this paper,

  18. Online cognition : factors facilitating reliable online neuropsychological test results

    NARCIS (Netherlands)

    Feenstra, Heleen E M; Vermeulen, Ivar E; Murre, Jaap M J; Schagen, Sanne B

    OBJECTIVE: Online neuropsychological test batteries could allow for large-scale cognitive data collection in clinical studies. However, the few online neuropsychological test batteries that are currently available often still require supervision or lack proper psychometric evaluation. In this paper,

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

    Science.gov (United States)

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

    2001-01-01

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

  20. Development of a 20 MeV Dielectric-Loaded Accelerator Test Facility

    International Nuclear Information System (INIS)

    Gold, Steven H.; Fliflet, Arne W.; Kinkead, Allen K.; Gai Wei; Power, John G.; Konecny, Richard; Jing Chunguang; Tantawi, Sami G.; Nantista, Christopher D.; Hu, Y.; Chen, H.; Tang, C.; Lin, Y.; Bruce, Ralph W.; Bruce, Robert L.; Lewis, David III

    2004-01-01

    This paper describes a joint project by the Naval Research Laboratory (NRL) and Argonne National Laboratory (ANL), in collaboration with the StanFord Linear Accelerator Center (SLAC), to develop a dielectric-loaded accelerator (DLA) test facility powered by a high-power 11.424-GHz magnicon amplifier. The magnicon can presently produce 25 MW of output power in a 250-ns pulse at 10 Hz, and efforts are in progress to increase this to 50 MW. The facility will include a 5 MeV electron injector being developed by the Accelerator Laboratory of Tsinghua University in Beijing, China. The DLA test structures are being developed by ANL, and some have undergone testing at NRL at gradients up to ∼8 MV/m. SLAC is developing a means to combine the two magnicon output arms, and to drive an injector and accelerator with separate control of the power ratio and relative phase. RWBruce Associates, Inc., working with NRL, is developing a means to join short ceramic sections into a continuous accelerator tube by ceramic brazing using an intense millimeter-wave beam. The installation and testing of the first dielectric-loaded test accelerator, including injector, DLA structure, and spectrometer, should take place within the next year. The facility will be used for testing DLA structures using a variety of materials and configurations, and also for testing other X-band accelerator concepts. The initial goal is to produce a compact 20 MeV dielectric-loaded test accelerator

  1. Accelerated weathering of fire-retardant-treated wood for fire testing

    Science.gov (United States)

    Robert H. White

    2009-01-01

    Fire-retardant-treated products for exterior applications must be subjected to actual or accelerated weathering prior to fire testing. For fire-retardant-treated wood, the two accelerated weathering methods have been Method A and B of ASTM D 2898. The rain test is Method A of ASTM D 2898. Method B includes exposures to ultraviolet (UV) sunlamps in addition to water...

  2. Design of PH-based accelerated life testing plans under multiple-stress-type

    International Nuclear Information System (INIS)

    Elsayed, E.A.; Zhang Hao

    2007-01-01

    Accelerated life testing (ALT) is used to obtain failure time data quickly under high stress levels in order to predict product life performance under design stress conditions. Most of the previous work on designing ALT plans is focused on the application of a single stress. However, as components or products become more reliable due to technological advances, it becomes more difficult to obtain significant amount of failure data within reasonable amount of time using single stress only. Multiple-stress-type ALTs have been employed as a means of overcoming such difficulties. In this paper, we design optimum multiple-stress-type ALT plans based on the proportional hazards model. The optimum combinations of stresses and their levels are determined such that the variance of the reliability estimate of the product over a specified period of time is minimized. The use of the model is illustrated using numerical example, and sensitivity analysis shows that the resultant optimum ALT plan is robust to the deviation in model parameters

  3. Intra-Rater, Inter-Rater and Test-Retest Reliability of an Instrumented Timed Up and Go (iTUG Test in Patients with Parkinson's Disease.

    Directory of Open Access Journals (Sweden)

    Rob C van Lummel

    Full Text Available The "Timed Up and Go" (TUG is a widely used measure of physical functioning in older people and in neurological populations, including Parkinson's Disease. When using an inertial sensor measurement system (instrumented TUG [iTUG], the individual components of the iTUG and the trunk kinematics can be measured separately, which may provide relevant additional information.The aim of this study was to determine intra-rater, inter-rater and test-retest reliability of the iTUG in patients with Parkinson's Disease.Twenty eight PD patients, aged 50 years or older, were included. For the iTUG the DynaPort Hybrid (McRoberts, The Hague, The Netherlands was worn at the lower back. The device measured acceleration and angular velocity in three directions at a rate of 100 samples/s. Patients performed the iTUG five times on two consecutive days. Repeated measurements by the same rater on the same day were used to calculate intra-rater reliability. Repeated measurements by different raters on the same day were used to calculate intra-rater and inter-rater reliability. Repeated measurements by the same rater on different days were used to calculate test-retest reliability.Nineteen ICC values (15% were ≥ 0.9 which is considered as excellent reliability. Sixty four ICC values (49% were ≥ 0.70 and < 0.90 which is considered as good reliability. Thirty one ICC values (24% were ≥ 0.50 and < 0.70, indicating moderate reliability. Sixteen ICC values (12% were ≥ 0.30 and < 0.50 indicating poor reliability. Two ICT values (2% were < 0.30 indicating very poor reliability.In conclusion, in patients with Parkinson's disease the intra-rater, inter-rater, and test-retest reliability of the individual components of the instrumented TUG (iTUG was excellent to good for total duration and for turning durations, and good to low for the sub durations and for the kinematics of the SiSt and StSi. The results of this fully automated analysis of instrumented TUG movements

  4. Potential Application of Magnetohydrodynamic Acceleration to Hypersonic Environmental Testing

    Science.gov (United States)

    1990-08-01

    homopolar generators, and compulsators should be evaluated along with solid-state converters. 86 AEDC-TR-90-6 B.4.2 Design Study of Control and...heater as a source of hot air for accelerator research. One could consider using motor generator power supplies for the arc heater as d3ne tor the

  5. Development of laboratory acceleration test method for service life prediction of concrete structures

    International Nuclear Information System (INIS)

    Cho, M. S.; Song, Y. C.; Bang, K. S.; Lee, J. S.; Kim, D. K.

    1999-01-01

    Service life prediction of nuclear power plants depends on the application of history of structures, field inspection and test, the development of laboratory acceleration tests, their analysis method and predictive model. In this study, laboratory acceleration test method for service life prediction of concrete structures and application of experimental test results are introduced. This study is concerned with environmental condition of concrete structures and is to develop the acceleration test method for durability factors of concrete structures e.g. carbonation, sulfate attack, freeze-thaw cycles and shrinkage-expansion etc

  6. Qualification Testing Versus Quantitative Reliability Testing of PV - Gaining Confidence in a Rapidly Changing Technology: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Sarah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Repins, Ingrid L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hacke, Peter L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Jordan, Dirk [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Kempe, Michael D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Whitfield, Kent [Underwriters Laboratories; Phillips, Nancy [DuPont; Sample, Tony [European Commission; Monokroussos, Christos [TUV Rheinland; Hsi, Edward [Swiss RE; Wohlgemuth, John [PowerMark Corporation; Seidel, Peter [First Solar; Jahn, Ulrike [TUV Rheinland; Tanahashi, Tadanori [National Institute of Advanced Industrial Science and Technology; Chen, Yingnan [China General Certification Center; Jaeckel, Bengt [Underwriters Laboratories; Yamamichi, Masaaki [RTS Corporation

    2017-10-05

    Continued growth of PV system deployment would be enhanced by quantitative, low-uncertainty predictions of the degradation and failure rates of PV modules and systems. The intended product lifetime (decades) far exceeds the product development cycle (months), limiting our ability to reduce the uncertainty of the predictions for this rapidly changing technology. Yet, business decisions (setting insurance rates, analyzing return on investment, etc.) require quantitative risk assessment. Moving toward more quantitative assessments requires consideration of many factors, including the intended application, consequence of a possible failure, variability in the manufacturing, installation, and operation, as well as uncertainty in the measured acceleration factors, which provide the basis for predictions based on accelerated tests. As the industry matures, it is useful to periodically assess the overall strategy for standards development and prioritization of research to provide a technical basis both for the standards and the analysis related to the application of those. To this end, this paper suggests a tiered approach to creating risk assessments. Recent and planned potential improvements in international standards are also summarized.

  7. Integrated Vibration and Acceleration Testing to Reduce Payload Mass, Cost and Mission Risk, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop a capability to provide integrated acceleration, vibration, and shock testing using a state-of-the-art centrifuge, allowing for the test of...

  8. A REVIEW OF SINGLE SPECIES TOXICITY TESTS: ARE THE TESTS RELIABLE PREDICTORS OF AQUATIC ECOSYSTEM COMMUNITY RESPONSES?

    Science.gov (United States)

    This document provides a comprehensive review to evaluate the reliability of indicator species toxicity test results in predicting aquatic ecosystem impacts, also called the ecological relevance of laboratory single species toxicity tests.

  9. Reliability of candida skin test in the evaluation of T-cell function in ...

    African Journals Online (AJOL)

    Background: Both standardized and non-standardized candida skin tests are used in clinical practice for functional in-vivo assessment of cellular immunity with variable results and are considered not reliable under the age of 1 year. We sought to investigate the reliability of using manually prepared candida intradermal test ...

  10. Feasibility and reliability of physical fitness tests in older adults with intellectual disability : A pilot study

    NARCIS (Netherlands)

    Hilgenkamp, Thessa I. M.; van Wijck, Ruud; Evenhuis, Heleen M.

    Background Physical fitness is relevant for wellbeing and health, but knowledge on the feasibility and reliability of instruments to measure physical fitness for older adults with intellectual disability is lacking. Methods Feasibility and test-retest reliability of a physical fitness test battery

  11. Statistical Considerations in Choosing a Test Reliability Coefficient. ACT Research Report Series, 2012 (10)

    Science.gov (United States)

    Woodruff, David; Wu, Yi-Fang

    2012-01-01

    The purpose of this paper is to illustrate alpha's robustness and usefulness, using actual and simulated educational test data. The sampling properties of alpha are compared with the sampling properties of several other reliability coefficients: Guttman's lambda[subscript 2], lambda[subscript 4], and lambda[subscript 6]; test-retest reliability;…

  12. Reliability and validity of the rey visual design learning test in primary school children

    NARCIS (Netherlands)

    Wilhelm, P.

    2004-01-01

    The Rey Visual Design Learning Test (Rey, 1964, in Spreen & Strauss, 1991) assesses immediate memory span, new learning and recognition for non-verbal material. Three studies are presented that focused on the reliability and validity of the RVDLT in primary school children. Test-retest reliability

  13. Stand development and reliability tests of the thermal monitoring means for NPP

    International Nuclear Information System (INIS)

    Nalivaev, V.I.; Nikul'shin, V.S.; Kichigin, A.B.; Dirin, V.F.

    2003-01-01

    The paper is devoted to the reliability tests of thermoelectric thermometers and resistance thermometers during their operation in the nominal mode. Five stands Reliability are developed and operate for realization of tests of all manufactured thermal converters. delivered at NPP. Description of all stands are presented [ru

  14. Test-retest reliability of infant event related potentials evoked by faces.

    Science.gov (United States)

    Munsters, N M; van Ravenswaaij, H; van den Boomen, C; Kemner, C

    2017-04-05

    Reliable measures are required to draw meaningful conclusions regarding developmental changes in longitudinal studies. Little is known, however, about the test-retest reliability of face-sensitive event related potentials (ERPs), a frequently used neural measure in infants. The aim of the current study is to investigate the test-retest reliability of ERPs typically evoked by faces in 9-10 month-old infants. The infants (N=31) were presented with neutral, fearful and happy faces that contained only the lower or higher spatial frequency information. They were tested twice within two weeks. The present results show that the test-retest reliability of the face-sensitive ERP components is moderate (P400 and Nc) to substantial (N290). However, there is low test-retest reliability for the effects of the specific experimental manipulations (i.e. emotion and spatial frequency) on the face-sensitive ERPs. To conclude, in infants the face-sensitive ERP components (i.e. N290, P400 and Nc) show adequate test-retest reliability, but not the effects of emotion and spatial frequency on these ERP components. We propose that further research focuses on investigating elements that might increase the test-retest reliability, as adequate test-retest reliability is necessary to draw meaningful conclusions on individual developmental trajectories of the face-sensitive ERPs in infants. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  15. Research Note The reliability of a field test kit for the detection and ...

    African Journals Online (AJOL)

    Research Note The reliability of a field test kit for the detection and the persistence of ... Open Access DOWNLOAD FULL TEXT ... The objectives were to test a field kit for practicality and reliability, to assess the spread of the bacteria among ...

  16. Comparison of reading performance tests concerning difficulty of sentences and paragraphs and their reliability

    NARCIS (Netherlands)

    Brussee, T.; van Nispen, R.M.A.; Klerkx, E.M.F.J.; Knol, D.L.; van Rens, G.H.M.B.

    2015-01-01

    In research and practice, sentences or paragraphs of reading tests may be randomly chosen to assess reading performance. This means that in addition to test reliability, all sentences or paragraphs should be reliable and equally difficult to read. The sentences and paragraphs of five (un-)

  17. Test-Retest Reliability of a Survey to Measure Transport-Related Physical Activity in Adults

    Science.gov (United States)

    Badland, Hannah; Schofield, Grant

    2006-01-01

    The present research details test-retest reliability of a newly developed, telephone-administered TPA survey for adults. This instrument examines barriers, perceptions, and current travel behaviors to place of work/study and local convenience shops. Demonstrated test-retest reliability of the Active Friendly Environments-Transport-Related Physical…

  18. Validity and reliability testing of the Prenatal Psychosocial Profile.

    Science.gov (United States)

    Curry, M A; Campbell, R A; Christian, M

    1994-04-01

    Two studies of low-income pregnant women (N = 179) were done to examine the validity and reliability of the Prenatal Psychosocial Profile (PPP). The PPP, a composite of the Rosenberg Self-Esteem Scale, the Support Behaviors Inventory, and a newly developed measure of stress, is a brief, comprehensive clinical assessment of psychosocial risk during pregnancy. Construct validity of the stress scale was supported by theoretically predicted negative correlations with self-esteem, partner support, and support from others (N = 91). Convergent validity of the stress scale was demonstrated by a correlation of .71 with the Difficult Life Circumstances Scale. Adequate levels of internal consistency were found. Interrelationships between the four subscales were consistent with the underlying conceptualization, and there was beginning evidence of the factorial independence of the subscales.

  19. NASA preferred reliability-practices for design and test

    Science.gov (United States)

    Lisk, Ronald C.

    1992-01-01

    NASA HQ established the NASA R&M Steering Committee (R&MSC) comprised of membership from each NASA field center. The primary charter of the R&MSC is to obtain, record, and share the best design practices that NASA has applied to successful space flight programs and current design considerations (guidelines) that should enhance flight reliability on emerging programs. The practices and guidelines are being assembled in a living document for distribution to NASA centers and the aerospace community. The document will be updated annually with additional practices and guidelines as contributions from the centers are reviewed and approved by the R&MSC. Practices and guidelines are not requirements, but rather a means of sharing procedures and techniques that a given center and the R&MSC together feel have strong technical merit and application to the design of space-related equipment.

  20. Testing the reliability of ice-cream cone model

    Science.gov (United States)

    Pan, Zonghao; Shen, Chenglong; Wang, Chuanbing; Liu, Kai; Xue, Xianghui; Wang, Yuming; Wang, Shui

    2015-04-01

    Coronal Mass Ejections (CME)'s properties are important to not only the physical scene itself but space-weather prediction. Several models (such as cone model, GCS model, and so on) have been raised to get rid of the projection effects within the properties observed by spacecraft. According to SOHO/ LASCO observations, we obtain the 'real' 3D parameters of all the FFHCMEs (front-side full halo Coronal Mass Ejections) within the 24th solar cycle till July 2012, by the ice-cream cone model. Considering that the method to obtain 3D parameters from the CME observations by multi-satellite and multi-angle has higher accuracy, we use the GCS model to obtain the real propagation parameters of these CMEs in 3D space and compare the results with which by ice-cream cone model. Then we could discuss the reliability of the ice-cream cone model.

  1. TEST-RETEST RELIABILITY OF THE CLOSED KINETIC CHAIN UPPER EXTREMITY STABILITY TEST (CKCUEST) IN ADOLESCENTS: RELIABILITY OF CKCUEST IN ADOLESCENTS.

    Science.gov (United States)

    de Oliveira, Valéria M A; Pitangui, Ana C R; Nascimento, Vinícius Y S; da Silva, Hítalo A; Dos Passos, Muana H P; de Araújo, Rodrigo C

    2017-02-01

    The Closed Kinetic Chain Upper Extremity Stability Test (CKCUEST) has been proposed as an option to assess upper limb function and stability; however, there are few studies that support the use of this test in adolescents. The purpose of the present study was to investigate the intersession reliability and agreement of three CKCUEST scores in adolescents and establish clinimetric values for this test. Test-retest reliability. Twenty-five healthy adolescents of both sexes were evaluated. The subjects performed two CKCUEST with an interval of one week between the tests. An intraclass correlation coefficient (ICC 3,3 ) two-way mixed model with a 95% interval of confidence was utilized to determine intersession reliability. A Bland-Altman graph was plotted to analyze the agreement between assessments. The presence of systematic error was evaluated by a one-sample t test. The difference between the evaluation and reevaluation was observed using a paired-sample t test. The level of significance was set at 0.05. Standard error of measurements and minimum detectable changes were calculated. The intersession reliability of the average touches score, normalized score, and power score were 0.68, 0.68 and 0.87, the standard error of measurement were 2.17, 1.35 and 6.49, and the minimal detectable change was 6.01, 3.74 and 17.98, respectively. The presence of systematic error (p test with moderate to excellent reliability when used with adolescents. The CKCUEST is a measurement with moderate to excellent reliability for adolescents. 2b.

  2. Maximal cardiorespiratory fitness testing in individuals with chronic stroke with cognitive impairment: practice test effects and test-retest reliability.

    Science.gov (United States)

    Olivier, Charles; Doré, Jean; Blanchet, Sophie; Brooks, Dina; Richards, Carol L; Martel, Guy; Robitaille, Nancy-Michelle; Maltais, Désirée B

    2013-11-01

    To evaluate, for individuals with chronic stroke with cognitive impairment, (1) the effects of a practice test on peak cardiorespiratory fitness test results; (2) cardiorespiratory fitness test-retest reliability; and (3) the relationship between individual practice test effects and cognitive impairment. Cross-sectional. Rehabilitation center. A convenience sample of 21 persons (men [n=12] and women [n=9]; age range, 48-81y; 44.9±36.2mo poststroke) with cognitive impairments who had sufficient lower limb function to perform the test. Not applicable. Peak oxygen consumption (Vo(2)peak, ml·kg(-1)·min(-1)). Test-retest reliability of Vo(2)peak was excellent (intraclass correlation coefficient model 2,1 [ICC2,1]=.94; 95% confidence interval [CI], .86-.98). A paired t test showed that there was no significant difference for the group for Vo(2)peak obtained from 2 symptom-limited cardiorespiratory fitness tests performed 1 week apart on a semirecumbent cycle ergometer (test 2-test 1 difference, -.32ml·kg(-1)·min(-1); 95% CI, -.69 to 1.33ml·kg(-1)·min(-1); P=.512). Individual test-retest differences in Vo(2)peak were, however, positively related to general cognitive function as measured by the Mini-Mental State Examination (ρ=.485; Preliably measured in this group without a practice test. General cognitive function, however, may influence the effect of a practice test in that those with lower general cognitive function appear to respond differently to a practice test than those with higher cognitive function. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  3. Development of an accelerated leach test(s) for low-level waste forms

    International Nuclear Information System (INIS)

    Dougherty, D.R.; Fuhrmann, M.; Colombo, P.

    1986-01-01

    An accelerated leach test(s) is being developed to predict long-term leaching behavior of low-level radioactive waste (LLW) forms in their disposal environments. As necessary background, a literature survey of reported leaching mechanisms, available mathematical models and factors that affect leaching of LLW forms has been compiled. Mechanisms which have been identified include diffusion, dissolution, ion exchange, corrosion and surface effects. A computerized data base of LLW leaching data and mathematical models is being developed. The data is being used for model evaluation by curve fitting and statistical analysis according to standard procedures of statistical quality control. Long-term leach tests on portland cement, bitumen and vinyl ester-styrene (VES) polymer waste forms are underway which are designed to identify and evaluate factors that accelerate leaching without changing the mechanisms. Initial results on the effect of temperature on leachability indicate that the leach rates of cement and VES waste forms increase with increasing temperature, whereas, the leach rate of bitumen is little affected

  4. Development of an accelerated leach test(s) for low-level waste forms

    International Nuclear Information System (INIS)

    Dougherty, D.R.; Fuhrmann, M.; Colombo, P.

    1985-01-01

    An accelerated leach test(s) is being developed to predict long-term leaching behavior of low-level radioactive waste (LLW) forms in their disposal environments. As necessary background, a literature survey of reported leaching mechanisms, available mathematical models and factors that affect leaching of LLW forms has been compiled. Mechanisms which have been identified include diffusion, dissolution, ion exchange, corrosion and surface effects. A computerized data base of LLW leaching data and mathematical models is being developed. The data is being used for model evaluation by curve fitting and statistical analysis according to standard procedures of statistical quality control. Long-term leach tests on portland cement, bitumen and vinyl ester-styrene (VES) polymer waste forms are underway which are designed to identify and evaluate factors that accelerate leaching without changing the mechanisms. Initial results on the effect of temperature on leachability indicate that the leach rates of cement and VES waste forms increase with increasing temperature, whereas, the leach rate of bitumen is little affected. 10 refs., 5 figs

  5. Reliability Of Kraus-Weber Exercise Test As An Evaluation Tool In ...

    African Journals Online (AJOL)

    Reliability Of Kraus-Weber Exercise Test As An Evaluation Tool In Low Back ... strength and flexibility of the back, abdominal, psoas and hamstring muscles. ... Keywords: Kraus-Weber test, low back pain, muscle flexibility, muscle strength.

  6. A 1MeV, 1A negative ion accelerator test facility

    International Nuclear Information System (INIS)

    Hanada, M.; Dairaku, M.; Inoue, T.; Miyamoto, K.; Ohara, Y.; Okumura, Y.; Watanabe, K.; Yokoyama, K.

    1995-01-01

    For the Proof-of-Principle test of negative ion acceleration up to 1 MeV, the beam energy required for ITER, a negative ion test facility named MeV Test Facility (MTF) and an ion source/accelerator have been designed and constructed. They are designed to produce a 1 MeV H- beam at a low source pressure of 0.13Pa. The MTF has a power supply system, which constituts of a 1MV, 1A, 60 s Cockcroft-Walton type dc high energy generator and power supplies for negative ion generation and extraction (ion source power supplies). The negative ion source/accelerator is composed of a cesiated volume source and a 5-stage, multi-aperture, electrostatic accelerator. The MTF and the ion source/accelerator have been completed, and the accelertion test up to 1 MeV of the H- ions has started. (orig.)

  7. Optical diagnostics in the advanced test accelerator (ATA) environment

    International Nuclear Information System (INIS)

    Chong, Y.P.; Cornish, J.P.; Donnelly, D.

    1987-05-01

    The ATA is a 50-MeV, 10-kA, 70-ns pulsed electron beam accelerator that generates an extremely harsh environment for diagnostic measurements. Diagnostic targets placed in the beamline are subject to damage, frequently being destroyed by a single pulse. High radiation (x-ray, gamma, and neutron) and electromagnetic interference levels preclude placing components near the beamline that are susceptible to radiation damage. Examples of such components are integrated circuit elements, hydrocarbons such as Teflon insulation, and optical components that darken, resulting in transmission loss. Optical diagnostics play an important part in measuring experimental parameters such as the beam current density profile. A large number of optical lines of sight (LOS) are routinely deployed along the experimental beamlines that use the ATA beam. Gated TV cameras are located outside the accelerator tunnel, because the tunnel is inaccessible during operations. We will describe and discuss the difficulties, problems, and solutions encountered in making optical measurements in the ATA environment

  8. Reliability and accuracy of Cooper's test in male long distance runners

    OpenAIRE

    J.R. Alvero-Cruz; M.A. Giráldez García; E.A. Carnero

    2017-01-01

    Objective: Endurance capacity can be assessed by field test such as Cooper's test; however, reliability and accuracy are rarely reported in the literature. It was our aims to describe reliability and accuracy of Cooper's test in long distance runners. Method: Fifteen male long distance runners performed twice all-out Cooper's test in a 400 m track. Total distance covered, maximum heart rate (HR) and rate of perceived exertion were recorded. Bias correction factor (Bc) was used to describe ...

  9. Operational status of the Brookhaven National Laboratory Accelerator Test Facility

    International Nuclear Information System (INIS)

    Batchelor, K.; Ben-Zvi, I.; Chou, T.S.; Los Alamos National Lab., NM; Princeton Univ., NJ

    1989-01-01

    Design and operation of a 50 MeV Electron Linear Accelerator utilizing a low emittance (γ var epsilon = 5 to 10 mm-mrad) radio frequency gun operating at an output energy of 5 MeV and a charge of 1 nC is described. Design calculations and early radio frequency measurements and operational experience with the electron gun utilizing a dummy copper cathode in place of the proposed photocathode emitter are given. 6 refs., 9 figs., 1 tab

  10. Prototype bellows sealed nuclear valve development -reliability through testing

    International Nuclear Information System (INIS)

    Dixon, D.F.; Abbas, M.

    1978-01-01

    To assist in appraising bellows sealed valve performance, 10 tests were done on a ''1 in.'' prototype bellows sealed valve design. The tests simulated primary heat transport (PHT) system conditions for a 600 MWe CANDU-PHW. The design approach was to have all valve components outlast the bellows in endurance tests; this was achieved. The valve design meets the Atomic Energy of Canada Limited specification. For comparison, bellows fatigue failure data were fitted to both log-normal and Weibull distributions. A numerical example shows how to select valve stroke amplitude on the basis of valve flow requirement and the minimum acceptable fatigue life. (author)

  11. Acceleration Test Method for Failure Prediction of the End Cap Contact Region of Sodium Cooled Fast Reactor Fuel Rod

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung-Kyu; Lee, Young-Ho; Lee, Hyun-Seung; Lee, Kang-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-05-15

    This paper reports the results of an acceleration test to predict the contact-induced failure that could occur at the cylinder-to-hole joint for the fuel rod of a sodium-cooled fast reactor (SFR). To incorporate the fuel life of the SFR currently under development at KAERI (around 35,000 h), the acceleration test method of reliability engineering was adopted in this work. A finite element method was used to evaluate the flow-induced vibration frequency and amplitude for the test parameter values. Five specimens were tested. The failure criterion during the life of the SFR fuel was applied. The S-N curve of the HT-9, the material of concern, was used to obtain the acceleration factor. As a result, a test time of 16.5 h was obtained for each specimen. It was concluded that the B{sub 0.004} life would be guaranteed for the SFR fuel rods with 99% confidence if no failure was observed at any of the contact surfaces of the five specimens.

  12. Reliability of genetic bottleneck tests for detecting recent population declines

    NARCIS (Netherlands)

    Peery, M. Zachariah; Kirby, Rebecca; Reid, Brendan N.; Stoelting, Ricka; Doucet-Beer, Elena; Robinson, Stacie; Vasquez-Carrillo, Catalina; Pauli, Jonathan N.; Palsboll, Per J.

    The identification of population bottlenecks is critical in conservation because populations that have experienced significant reductions in abundance are subject to a variety of genetic and demographic processes that can hasten extinction. Genetic bottleneck tests constitute an appealing and

  13. On selection of optimal stochastic model for accelerated life testing

    Czech Academy of Sciences Publication Activity Database

    Volf, Petr; Timková, Jana

    2014-01-01

    Roč. 131, č. 1 (2014), s. 291-297 ISSN 0951-8320 Institutional support: RVO:67985556 Keywords : Reliability analysis * Goodness-of-fit * Bayes statistics Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 2.410, year: 2014 http://library.utia.cas.cz/separaty/2015/SI/volf-0444111.pdf

  14. Intertester reliability of the talk test in a cardiac rehabilitation population

    DEFF Research Database (Denmark)

    Petersen, Annemette Krintel; Maribo, Thomas; Hjortdal, Vibeke Elisabeth

    2013-01-01

    PURPOSE: The validity of the Talk Test (TT) is well documented, but the reliability of the test is not clear. The aim of this study was to assess the absolute and relative intertester reliability of the TT in cardiac patients. METHODS: Cardiac patients (n = 64) who had completed an exercise...... randomized to tests. Workload in watts at the first negative stage of the TT was registered as the test result. Patients and physiotherapists were blinded to test results of the first test. Absolute reliability of the TT was assessed with Bland-Altman plot, standard error of measurement, and minimal...... detectable change. Relative reliability was assessed using the intraclass correlation coefficient (ICC). RESULTS: Mean difference in peak workload between test and retest was 0.8 W (95% CI: -4.8 to 3.3). Limit of agreement was estimated to be +31/-32 W. Standard error of measurement was 11 W (95% CI: 10...

  15. Is gait variability reliable in older adults and Parkinson's disease? Towards an optimal testing protocol.

    Science.gov (United States)

    Galna, Brook; Lord, Sue; Rochester, Lynn

    2013-04-01

    Despite the widespread use of gait variability in research and clinical studies, testing protocols designed to optimise its reliability have not been established. This study evaluates the impact of testing protocol and pathology on the reliability of gait variability. To (i) estimate the reliability of gait variability during continuous and intermittent walking protocols in older adults and people with Parkinson's disease (PD), (ii) determine optimal number of steps for acceptable levels of reliability of gait variability and (iii) provide sample size estimates for use in clinical trials. Gait variability was measured twice, one week apart, in 27 older adults and 25 PD participants. Participants walked at their preferred pace during: (i) a continuous 2 min walk and (ii) 3 intermittent walks over a 12 m walkway. Gait variability was calculated as the within-person standard deviation for step velocity, length and width, and step, stance and swing duration. Reliability of gait variability ranged from poor to excellent (intra class correlations .041-.860; relative limits of agreement 34-89%). Gait variability was more reliable during continuous walks. Control and PD participants demonstrated similar reliability. Increasing the number of steps improved reliability, with most improvement seen across the first 30 steps. In this study, we identified testing protocols that improve the reliability of measuring gait variability. We recommend using a continuous walking protocol and to collect no fewer than 30 steps. Early PD does not appear to impact negatively on the reliability of gait variability. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Balance Assessment in Sports-Related Concussion: Evaluating Test-Retest Reliability of the Equilibrate System.

    Science.gov (United States)

    Odom, Mitchell J; Lee, Young M; Zuckerman, Scott L; Apple, Rachel P; Germanos, Theodore; Solomon, Gary S; Sills, Allen K

    2016-01-01

    This study evaluated the test-retest reliability of a novel computer-based, portable balance assessment tool, the Equilibrate System (ES), used to diagnose sports-related concussion. Twenty-seven students participated in ES testing consisting of three sessions over 4 weeks. The modified Balance Error Scoring System was performed. For each participant, test-retest reliability was established using the intraclass correlation coefficient (ICC). The ES test-retest reliability from baseline to week 2 produced an ICC value of 0.495 (95% CI, 0.123-0.745). Week 2 testing produced ICC values of 0.602 (95% CI, 0.279-0.803) and 0.610 (95% CI, 0.299-0.804), respectively. All other single measures test-retest reliability values produced poor ICC values. Same-day ES testing showed fair to good test-retest reliability while interweek measures displayed poor to fair test-retest reliability. Testing conditions should be controlled when using computerized balance assessment methods. ES testing should only be used as a part of a comprehensive assessment.

  17. Assessment of Advanced Life Support competence when combining different test methods--reliability and validity

    DEFF Research Database (Denmark)

    Ringsted, C; Lippert, F; Hesselfeldt, R

    2007-01-01

    Cardiac Arrest Simulation Test (CASTest) scenarios for the assessments according to guidelines 2005. AIMS: To analyse the reliability and validity of the individual sub-tests provided by ERC and to find a combination of MCQ and CASTest that provides a reliable and valid single effect measure of ALS...... that possessed high reliability, equality of test sets, and ability to discriminate between the two groups of supposedly different ALS competence. CONCLUSIONS: ERC sub-tests of ALS competence possess sufficient reliability and validity. A combined ALS score with equal weighting of one MCQ and one CASTest can...... competence. METHODS: Two groups of participants were included in this randomised, controlled experimental study: a group of newly graduated doctors, who had not taken the ALS course (N=17) and a group of students, who had passed the ALS course 9 months before the study (N=16). Reliability in terms of inter...

  18. Development of an accelerated creep testing procedure for geosynthetics.

    Science.gov (United States)

    1997-09-01

    The report presents a procedure for predicting creep strains of geosynthetics using creep tests at elevated temperatures. Creep testing equipment was constructed and tests were performed on two types of geosynthetics: High Density Polyethylene (HDPE)...

  19. High-power tests of a single-cell copper accelerating cavity driven by two input couplers

    International Nuclear Information System (INIS)

    Horan, D.; Bromberek, D.; Meyer, D.; Waldschmidt, G.

    2008-01-01

    High-power tests were conducted on a 350-MHz, single-cell copper accelerating cavity driven simultaneously by two H-loop input couplers for the purpose of determining the reliability, performance, and power-handling capability of the cavity and related components, which have routinely operated at 100-kW power levels. The test was carried out utilizing the APS 350-MHz RF Test Stand, which was modified to split the input rf power into two frac12-power feeds, each supplying power to a separate H-loop coupler on the cavity. Electromagnetic simulations of the two-coupler feed system were used to determine coupler match, peak cavity fields, and the effect of phasing errors between the coupler feed lines. The test was conducted up to a maximum total rf input power of 164-kW CW. Test apparatus details and performance data will be presented.

  20. AMSTERDAM-NIJMEGEN EVERYDAY LANGUAGE TEST - CONSTRUCTION, RELIABILITY AND VALIDITY

    NARCIS (Netherlands)

    BLOMERT, L; KEAN, ML; KOSTER, C; SCHOKKER, J

    1994-01-01

    The Amsterdam-Nijmegen Everyday Language Test (ANELT) is designed to measure, first, the level of verbal communicative abilities of aphasic patients and, second, changes in these abilities over time. The level of communicative effectiveness is determined by the adequacy of bringing a message across.