Intermediate Temperature Fluids Life Tests - Experiments

NASA Technical Reports Server (NTRS)

Anderson, William G.; Bonner, Richard W.; Dussinger, Peter M.; Hartenstine, John R.; Sarraf, David B.; Locci, Ivan E.

2007-01-01

There are a number of different applications that could use heat pipes or loop heat pipes (LHPs) in the intermediate temperature range of 450 to 725 K (170 to 450 C), including space nuclear power system radiators, fuel cells, and high temperature electronics cooling. Historically, water has been used in heat pipes at temperatures up to about 425 K (150 C). Recent life tests, updated below, demonstrate that titanium/water and Monel/water heat pipes can be used at temperatures up to 550 K (277 C), due to water's favorable transport properties. At temperatures above roughly 570 K (300 C), water is no longer a suitable fluid, due to high vapor pressure and low surface tension as the critical point is approached. At higher temperatures, another working fluid/envelope combination is required, either an organic or halide working fluid. An electromotive force method was used to predict the compatibility of halide working fluids with envelope materials. This procedure was used to reject aluminum and aluminum alloys as envelope materials, due to their high decomposition potential. Titanium and three corrosion resistant superalloys were chosen as envelope materials. Life tests were conducted with these envelopes and six different working fluids: AlBr3, GaCl3, SnCl4, TiCl4, TiBr4, and eutectic diphenyl/diphenyl oxide (Therminol VP-1/Dowtherm A). All of the life tests except for the GaCl3 are ongoing; the GaCl3 was incompatible. As the temperature approaches 725 K (450 C), cesium is a potential heat pipe working fluid. Life tests results are also presented for cesium/Monel 400 and cesium/70-30 copper/nickel heat pipes operating near 750 K (477 C). These materials are not suitable for long term operation, due to copper transport from the condenser to the evaporator.

International Space Station Alpha trace contaminant control subassembly life test report

NASA Technical Reports Server (NTRS)

Tatara, J. D.; Perry, J. L.

1995-01-01

The Environmental Control and Life Support System (ECLSS) Life Test Program (ELTP) began with Trace Contaminant Control Subassembly (TCCS) Life Testing on November 9, 1992, at 0745. The purpose of the test, as stated in the NASA document 'Requirements for Trace Contaminant Control Subassembly High Temperature Catalytic Oxidizer Life Testing (Revision A)' was to 'provide for the long duration operation of the ECLSS TCCS HTCO (High Temperature Catalytic Oxidizer) at normal operating conditions... (and thus)... to determine the useful life of ECLSS hardware for use on long duration manned space missions.' Specifically, the test was designed to demonstrate thermal stability of the HTCO catalyst. The report details TCCS stability throughout the test. Graphs are included to aid in evaluating trends and subsystem anomalies. The report summarizes activities through the final day of testing, January 17, 1995 (test day 762).

Accelerated life testing effects on CMOS microcircuit characteristics

NASA Technical Reports Server (NTRS)

1980-01-01

This report covers the time period from May 1976 to December 1979 and encompasses the three phases of accelerated testing: Phase 1, the 250 C testing; Phase 2, the 200 C testing; and Phase 3, the 125 C testing. The duration of the test in Phase 1 and Phase 2 was sufficient to take the devices into the wear out region. The wear out distributions were used to estimate the activation energy between the 250 C and the 200 C test temperatures. The duration of the 125 C test, 20,000 hours, was not sufficient to bring the test devices into the wear out region; consequently the third data point at 125 C for determining the consistency of activation energy could not be obtained. It was estimated that, for the most complex of the three device 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 was assessed. Guidelines for the development of accelerated life test conditions were proposed. The use of the silicon nitride overcoat to improve the high temperature accelerated life test characteristics of CMOS microcircuits was explored in Phase 4 of this study and is attached as an appendix to this report.

Life testing of secondary silver-zinc cells

NASA Technical Reports Server (NTRS)

Brewer, Jeffrey C.; Doreswamy, Rajiv

1991-01-01

Testing on a variety of secondary silver-zinc (Ag-Zn) cells has been in progress at the Marshall Space Flight Center (MSFC) for over six years. The latest test involves a 350-Ah cell design that has been cycled at 10 C for 16 months. This design has achieved over 7200 low-earth-orbit (LEO) cycles as well as 17 deep discharges at an 85 percent depth of discharge. This test not only is a life test on these cells but also addresses different methods of storing these cells between the deep discharges. As the test is approaching completion, some interesting results are being seen. In particular, two of the four packs currently on test have failed to meet the 35-h (295-Ah) deep discharge requirement that was arbitrarily set at the beginning of the test. This capacity loss failure is likely a result of the storage method used on these two packs between deep discharges. The two packs are LEO cycled in such a way as to minimize overcharge in an attempt to prolong life.

40 CFR 797.1600 - Fish early life stage toxicity test.

Code of Federal Regulations, 2014 CFR

2014-07-01

... the test solution concentrations. The test terminates following 60 days of post-hatch exposure (for an... 40 Protection of Environment 32 2014-07-01 2014-07-01 false Fish early life stage toxicity test... Fish early life stage toxicity test. (a) Purpose. This guideline is intended to be used for assessing...

40 CFR 797.1600 - Fish early life stage toxicity test.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the test solution concentrations. The test terminates following 60 days of post-hatch exposure (for an... 40 Protection of Environment 32 2011-07-01 2011-07-01 false Fish early life stage toxicity test... Fish early life stage toxicity test. (a) Purpose. This guideline is intended to be used for assessing...

Nickel-hydrogen cell low-earth-orbit life test update

NASA Technical Reports Server (NTRS)

Frate, David T.

1991-01-01

When individual pressure vessel (IPV) nickel-hydrogen (Ni/H2) cells were selected as the energy storage system for Space Station Freedom in March of 1986, a limited database existed on life and performance characteristics of these cells in a low earth orbit (LEO) regime. Therefore, NASA LeRC initiated a Ni/H2 cell test program with the primary objectives of building a test facility, procuring cells from existing NASA contracts, and screening several cell designs by life testing in a LEO 35 percent depth of discharge (DOD) scenario. A total of 40 cells incorporating 13 designs were purchased from Yardney, Hughes, and Eagle-Picher. Thirty-two of the cells purchased were 65 A-hr nameplate capacity and eight cells were 50 A-Hr. Yardney and Eagle-Picher cells were built with both the Air Force recirculating and the advanced back-to-back electrode stack configurations and incorporated 31 and 26 percent KOH. Acceptance testing of the first delivered cells began in March of 1988, with life testing following in September of that year. Performance comparisons of these cells are made here while specifically addressing life test data relative to the design differences.

New Insight into the Local Structure of Hydrous Ferric Arsenate Using Full-Potential Multiple Scattering Analysis, Density Functional Theory Calculations, and Vibrational Spectroscopy.

PubMed

Wang, Shaofeng; Ma, Xu; Zhang, Guoqing; Jia, Yongfeng; Hatada, Keisuke

2016-11-15

Hydrous ferric arsenate (HFA) is an important arsenic-bearing precipitate in the mining-impacted environment and hydrometallurgical tailings. However, there is no agreement on its local atomic structure. The local structure of HFA was reprobed by employing a full-potential multiple scattering (FPMS) analysis, density functional theory (DFT) calculations, and vibrational spectroscopy. The FPMS simulations indicated that the coordination number of the As-Fe, Fe-As, or both in HFA was approximately two. The DFT calculations constructed a structure of HFA with the formula of Fe(HAsO 4 ) x (H 2 AsO 4 ) 1-x (OH) y ·zH 2 O. The presence of protonated arsenate in HFA was also evidenced by vibrational spectroscopy. The As and Fe K-edge X-ray absorption near-edge structure spectra of HFA were accurately reproduced by FPMS simulations using the chain structure, which was also a reasonable model for extended X-Ray absorption fine structure fitting. The FPMS refinements indicated that the interatomic Fe-Fe distance was approximately 5.2 Å, consistent with that obtained by Mikutta et al. (Environ. Sci. Technol. 2013, 47 (7), 3122-3131) using wavelet analysis. All of the results suggested that HFA was more likely to occur as a chain with AsO 4 tetrahedra and FeO 6 octahedra connecting alternately in an isolated bidentate-type fashion. This finding is of significance for understanding the fate of arsenic and the formation of ferric arsenate minerals in an acidic environment.

The 50Ah NiH2 cell life test results

NASA Technical Reports Server (NTRS)

Jamin, Thierry; Puig, Olivier

1992-01-01

Information is given in viewgraph form for the 50 AhNiH2 cell life test results. Information is given on pressure vessel design, electrochemical/stack design, cell electrical characteristics, and cell life test results.

NASA's Advanced Life Support Systems Human-Rated Test Facility

NASA Technical Reports Server (NTRS)

Henninger, D. L.; Tri, T. O.; Packham, N. J.

1996-01-01

Future NASA missions to explore the solar system will be long-duration missions, requiring human life support systems which must operate with very high reliability over long periods of time. Such systems must be highly regenerative, requiring minimum resupply, to enable the crews to be largely self-sufficient. These regenerative life support systems will use a combination of higher plants, microorganisms, and physicochemical processes to recycle air and water, produce food, and process wastes. A key step in the development of these systems is establishment of a human-rated test facility specifically tailored to evaluation of closed, regenerative life supports systems--one in which long-duration, large-scale testing involving human test crews can be performed. Construction of such a facility, the Advanced Life Support Program's (ALS) Human-Rated Test Facility (HRTF), has begun at NASA's Johnson Space Center, and definition of systems and development of initial outfitting concepts for the facility are underway. This paper will provide an overview of the HRTF project plan, an explanation of baseline configurations, and descriptive illustrations of facility outfitting concepts.

Bypass control valve seal and bearing life cycle test report

NASA Technical Reports Server (NTRS)

Lundback, A. V.

1972-01-01

The operating characteristics of a bypass control valve seal and bearing life cycle tests are reported. Data from the initial assembly, leak, torque, and deflection tests are included along with the cycle life test results and conclusions. The equipment involved was to be used in the nuclear engine for the rocket vehicles program.

Benchmark Tests for Stirling Convertor Heater Head Life Assessment Conducted

NASA Technical Reports Server (NTRS)

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

2004-01-01

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

EOS--AM1 Nickel Hydrogen Cell Interim Life Test Report

NASA Technical Reports Server (NTRS)

Bennett, C. W.; Keys, D. J.; Rao, G. M.; Wannemacher, H. E.; Vaidyanathan H.

1999-01-01

This paper reports the interim results of the Earth Observing System AM-1 project (EOS-AM-1) nickel hydrogen cell life test being conducted under contract to National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) at the Lockheed Martin Missiles and Space (LMMS) facility in East Windsor, NJ; and at COMSAT Labs., Clarksburg, MD. The purpose of the tests is to verify that the EOS-AM-1 cell design can meet five years of real-time Low Earth Orbit (LEO) cycling. The tests include both real-time LEO and accelerated stress tests. At LMMS, the first real-time LEO simulated 99 minute orbital cycle started on February 7, 1994 and the test has been running continuously since that time, with 18202 LEO cycles completed as of September 1, 1997. Each cycle consists of a 64 minute charge (VT at 1.507 volts per cell. 1.06 C/D ratio, followed by 0.6 ampere trickle charge) and a 35 minute constant power discharge at 177 watts (22.5% DOD). At COMSAT, the accelerated stress test consists of 90 minute orbital cycles at 60% DOD with a 30 minute discharge at 60 amperes and a 60 minute charge at 40 amperes (VT at 1.54 volts per cell to 1.09 C/D ratio, followed by 0.6 ampere trickle charge). The real-time LEO life test battery consists of seven, 50AH (nameplate rating) Eagle-Picher, Inc. (EPI) Mantech cells manufactured into three. 3-cell pack assemblies (there are two place holder cells that are not part of the life test electrical circuit). The test pack is configured to simulate the conductive thermal design of the spacecraft battery, including: conductive aluminum sleeves, 3-cell pack aluminum baseplate, and honeycomb panel all mounted to a liquid (-5 C) cold plate. The entire assembly is located in a thermal chamber operatina at +30 C. The accelerated stress test unit consists of five cells mounted in machined aluminum test sleeves and is operating at +10 C. The real-time LEO life test battery has met all performance requirements throuch the first 18

EOS-AM1 Nickel Hydrogen Cell Interim Life Test Report

NASA Technical Reports Server (NTRS)

Bennett, Charles W.; Keys, D. J.; Rao, G. M.; Wannemacher, H. E.; Vaidyanathan, Hari

1998-01-01

This paper reports the interim results Earth Observing System AM-1 project (EOS-AM-1) nickel hydrogen cell life test being conducted under contract to National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) at the Lockheed Martin Missiles and Space (LMMS) facility in East Windsor, NJ; and at COMSAT Labs., Clarksburg, MD. The purpose of the tests is to verify that the EOS-AM-1 cell design can meet five years of real-time Low Earth Orbit (LEO) cycling. The tests include both real-time LEO and accelerated stress tests. At LMMS, the first real-time LEO simulated 99 minute orbital cycle started on February 7, 1994 and the test has been running continuously since that time, with 18202 LEO cycles completed as of September 1, 1997. Each cycle consists of a 64-minute charge (VT at 1,507 volts per cell, 1.06 C/D ratio, followed by 0.6 ampere trickle charge) and a 35 minute constant power discharge at 177 watts (22.5 percent DOD). At COMSAT, the accelerated stress test consists of 90 minute orbital cycles at 60 percent DOD with a 30 minute discharge at 60 amperes and a 60 minute charge at 40 amperes (VT at 1.54 volts per cell to 1.90 C/D ratio, followed by 0.6 ampere trickle charge). The real-time LEO life test battery consists of seven, 50AH (nameplate rating) Eagle-Picher, Inc. (EPI) Mantech cells manufactured into three, 3-cell pack assemblies (there are two place holder cells that are not part of the life test electrical circuit). The test pack is configured to simulate the conductive thermal design of the spacecraft battery, including: conductive aluminum sleeves, 3-cell pack aluminum baseplate, and honeycomb panel all mounted to a liquid (minus 5 deg) cold plate. The entire assembly is located in a thermal chamber operating at plus 3 deg. The accelerated stress test unit consists of five cells mounted in machined aluminum test sleeves and is operating at plus 10 deg. The real-time LEO life test battery has met all performance requirements

Shelf life prediction of canned fried-rice using accelerated shelf life testing (ASLT) arrhenius method

NASA Astrophysics Data System (ADS)

Kurniadi, M.; Bintang, R.; Kusumaningrum, A.; Nursiwi, A.; Nurhikmat, A.; Susanto, A.; Angwar, M.; Triwiyono; Frediansyah, A.

2017-12-01

Research on shelf-life prediction of canned fried rice using Accelerated Shelf-life Test (ASLT) of Arrhenius model has been conducted. The aim of this research to predict shelf life of canned-fried rice products. Lethality value of 121°C for 15 and 20 minutes and Total Plate count methods are used to determine time and temperatures of sterilization process.Various storage temperatures of ASLT Arrhenius method were 35, 45 and 55°C during 35days. Rancidity is one of the derivation quality of canned fried rice. In this research, sample of canned fried rice is tested using rancidity value (TBA). TBA value was used as parameter which be measured once a week periodically. The use of can for fried rice without any chemical preservative is one of the advantage of the product, additionaly the use of physicalproperties such as temperature and pressure during its process can extend the shelf life and reduce the microbial contamination. The same research has never done before for fried rice as ready to eat meal. The result showed that the optimum conditions of sterilization process were 121°C,15 minutes with total plate count number of 9,3 × 101 CFU/ml. Lethality value of canned fried rice at 121°C,15 minutes was 3.63 minutes. The calculated Shelf-life of canned fried rice using Accelerated Shelf-life Test (ASLT) of Arrhenius method was 10.3 months.

Closure of regenerative life support systems: results of the Lunar-Mars Life Support Test Project

NASA Astrophysics Data System (ADS)

Barta, D.; Henninger, D.; Edeen, M.; Lewis, J.; Smith, F.; Verostko, C.

Future long duration human exploration missions away from Earth will require closed-loop regenerative life support systems to reduce launch mass reduce dependency on resupply and increase the level of mission self sufficiency Such systems may be based on the integration of biological and physiocochemical processes to produce potable water breathable atmosphere and nutritious food from metabolic and other mission wastes Over the period 1995 to 1998 a series of ground-based tests were conducted at the National Aeronautics and Space Administration Johnson Space Center to evaluate the performance of advanced closed-loop life support technologies with real human metabolic and hygiene loads Named the Lunar-Mars Life Support Test Project LMLSTP four integrated human tests were conducted with increasing duration complexity and closure The first test LMLSTP Phase I was designed to demonstrate the ability of higher plants to revitalize cabin atmosphere A single crew member spent 15 days within an atmospherically closed chamber containing 11 2 square meters of actively growing wheat Atmospheric carbon dioxide and oxygen levels were maintained by control of the rate of photosynthesis through manipulation of light intensity or the availability of carbon dioxide and included integrated physicochemical systems During the second and third tests LMLSTP Phases II IIa four crew members spent 30 days and 60 days respectively in a larger sealed chamber Advanced physicochemical life support hardware was used to regenerate the atmosphere and produce potable water

Benchmark notch test for life prediction

NASA Technical Reports Server (NTRS)

Domas, P. A.; Sharpe, W. N.; Ward, M.; Yau, J. F.

1982-01-01

The laser Interferometric Strain Displacement Gage (ISDG) was used to measure local strains in notched Inconel 718 test bars subjected to six different load histories at 649 C (1200 F) and including effects of tensile and compressive hold periods. The measurements were compared to simplified Neuber notch analysis predictions of notch root stress and strain. The actual strains incurred at the root of a discontinuity in cyclically loaded test samples subjected to inelastic deformation at high temperature where creep deformations readily occur were determined. The steady state cyclic, stress-strain response at the root of the discontinuity was analyzed. Flat, double notched uniaxially loaded fatigue specimens manufactured from the nickel base, superalloy Inconel 718 were used. The ISDG was used to obtain cycle by cycle recordings of notch root strain during continuous and hold time cycling at 649 C. Comparisons to Neuber and finite element model analyses were made. The results obtained provide a benchmark data set in high technology design where notch fatigue life is the predominant component service life limitation.

Test of US Federal Life Cycle Inventory Data Interoperability

EPA Science Inventory

Life cycle assessment practitioners must gather data from a variety of sources. For modeling activities in the US, practitioners may wish to use life cycle inventory data from public databases and libraries provided by US government entities. An exercise was conducted to test if ...

Proof-test-based life prediction of high-toughness pressure vessels

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

Panontin, T.L.; Hill, M.R.

1996-02-01

The paper examines the problems associated with applying proof-test-based life prediction to vessels made of high-toughness metals. Two A106 Gr B pipe specimens containing long, through-wall circumferential flaws were tested. One failed during hydrostatic testing and the other during tension-tension cycling following a hydrostatic test. Quantitative fractography was used to verify experimentally obtained fatigue crack growth rates and a variety of LEFM and EPFM techniques were used to analyze the experimental results. The results show that: plastic collapse analysis provides accurate predictions of screened (initial) crack size when the flow stress is determined experimentally; LEFM analysis underestimates the crack sizemore » screened by the proof test and overpredicts the subsequent fatigue life of the vessel when retardation effects are small (i.e., low proof levels); and, at a high proof-test level (2.4 {times} operating pressure), the large retardation effect on fatigue crack growth due to the overload overwhelmed the deleterious effect on fatigue life from stable tearing during the proof test and alleviated the problem of screening only long cracks due to the high toughness of the metal.« less

Shelf Life Prediction for Canned Gudeg using Accelerated Shelf Life Testing (ASLT) Based on Arrhenius Method

NASA Astrophysics Data System (ADS)

Nurhayati, R.; Rahayu NH, E.; Susanto, A.; Khasanah, Y.

2017-04-01

Gudeg is traditional food from Yogyakarta. It is consist of jackfruit, chicken, egg and coconut milk. Gudeg generally have a short shelf life. Canning or commercial sterilization is one way to extend the shelf life of gudeg. This aims of this research is to predict the shelf life of Andrawinaloka canned gudeg with Accelerated Shelf Life Test methods, Arrhenius model. Canned gudeg stored at three different temperature, there are 37, 50 and 60°C for two months. Measuring the number of Thio Barbituric Acid (TBA), as a critical aspect, were tested every 7 days. Arrhenius model approach is done with the equation order 0 and order 1. The analysis showed that the equation of order 0 can be used as an approach to estimating the shelf life of canned gudeg. The storage of Andrawinaloka canned gudeg at 30°C is predicted untill 21 months and 24 months for 25°C.

Improvement of bench life-tests for automotive batteries

NASA Astrophysics Data System (ADS)

Richter, G.

A common method for rating the endurance of automotive batteries is the bench life-test according to DIN, IEC, SAE or JIS. With an increasing number of maintenance-free batteries on the market, the application of these tests becomes more problematic. This is due to a step-by-step capacity decline during cycling if the content of autimony in the grid-alloy is decreased. The degradation in performance is caused by the phenomenon of acid stratification. Because this debilitating effect occurs only rarely in service (vehicle movement) if charging and discharging is well balanced, there is a need for a new bench life-test with conditions that are more representative of practical conditions. Research has shown that the main changes should be: (i) an accelerated (moved) battery during cycling; (ii) slightly lower charging or discharging capacity amplitude, also with a lower mean value.

Accelerated life testing effects on CMOS microcircuit characteristics

NASA Technical Reports Server (NTRS)

1977-01-01

Accelerated life tests were performed on CMOS microcircuits to predict their long term reliability. The consistency of the CMOS microcircuit activation energy between the range of 125 C to 200 C and the range 200 C to 250 C was determined. Results indicate CMOS complexity and the amount of moisture detected inside the devices after testing influences time to failure of tested CMOS devices.

Johnson Space Center's Regenerative Life Support Systems Test Bed

NASA Technical Reports Server (NTRS)

Barta, D. J.; Henninger, D. L.

1996-01-01

The Regenerative Life Support Systems (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for human testing of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. The facility supports NASA's Advanced Life Support (ALS) Program. The facility is comprised of two large scale plant growth chambers, each with approximately 11 m2 growing area. The root zone in each chamber is configurable for hydroponic or solid media plant culture systems. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), is capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in a planetary surface habitat; the other chamber, the Ambient Pressure Growth Chamber (APGC) operates at ambient atmospheric pressure. The air lock of the VPGC is currently being outfitted for short duration (1 to 15 day) human habitation at ambient pressures. Testing with and without human subjects will focus on 1) integration of biological and physicochemical air and water revitalization systems; 2) effect of atmospheric pressure on system performance; 3) planetary resource utilization for ALS systems, in which solid substrates (simulated planetary soils or manufactured soils) are used in selected crop growth studies; 4) environmental microbiology and toxicology; 5) monitoring and control strategies; and 6) plant growth systems design. Included are descriptions of the overall design of the test facility, including discussions of the atmospheric conditioning, thermal control, lighting, and nutrient delivery systems.

Johnson Space Center's Regenerative Life Support Systems Test Bed

NASA Astrophysics Data System (ADS)

Barta, D. J.; Henninger, D. L.

1996-01-01

The Regenerative Life Support Systems (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for human testing of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. The facility supports NASA's Advanced Life Support (ALS) Program. The facility is comprised of two large scale plant growth chambers, each with approximately 11 m^2 growing area. The root zone in each chamber is configurable for hydroponic or solid media plant culture systems. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), is capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in a planetary surface habitat; the other chamber, the Ambient Pressure Growth Chamber (APGC) operates at ambient atmospheric pressure. The air lock of the VPGC is currently being outfitted for short duration (1 to 15 day) human habitation at ambient pressures. Testing with and without human subjects will focus on 1) integration of biological and physicochemical air and water revitalization systems; 2) effect of atmospheric pressure on system performance; 3) planetary resource utilization for ALS systems, in which solid substrates (simulated planetary soils or manufactured soils) are used in selected crop growth studies; 4) environmental microbiology and toxicology; 5) monitoring and control strategies; and 6) plant growth systems design. Included are descriptions of the overall design of the test facility, including discussions of the atmospheric conditioning, thermal control, lighting, and nutrient delivery systems.

Life Test Approach for Refractory Metal/Sodium Heat Pipes

NASA Technical Reports Server (NTRS)

Martin, James J.; Reid, Robert S.

2006-01-01

Heat pipe life tests described in the literature have seldom been conducted on a systematic basis. Typically one or more heat pipes are built and tested for an extended period at a single temperature with simple condenser loading. This paper describes an approach to generate carefully controlled data that can conclusively establish heat pipe operating life with material-fluid combinations capable of extended operation. Approximately 10 years of operational life might be compressed into 3 years of laboratory testing through a combination of increased temperature and mass fluence. Two specific test series have been identified and include: investigation of long term corrosion rates based on the guidelines contained in ASTM G-68-80 (using 7 heat pipes); and investigation of corrosion trends in a cross correlation sequence at various temperatures and mass fluences based on a central composite test design (using 9 heat pipes). The heat pipes selected for demonstration purposes are fabricated from a Mo-44.5%Re alloy with a length of 0.3 meters and a diameter of 1.59 cm(to conserve material) with a condenser to evaporator length ratio of approximately 3. The wick is a crescent annular design formed from 400-mesh Mo-Re alloy material hot isostatically pressed to produce a final wick core of 20 microns or less.

Decision Models for Determining the Optimal Life Test Sampling Plans

NASA Astrophysics Data System (ADS)

Nechval, Nicholas A.; Nechval, Konstantin N.; Purgailis, Maris; Berzins, Gundars; Strelchonok, Vladimir F.

2010-11-01

Life test sampling plan is a technique, which consists of sampling, inspection, and decision making in determining the acceptance or rejection of a batch of products by experiments for examining the continuous usage time of the products. In life testing studies, the lifetime is usually assumed to be distributed as either a one-parameter exponential distribution, or a two-parameter Weibull distribution with the assumption that the shape parameter is known. Such oversimplified assumptions can facilitate the follow-up analyses, but may overlook the fact that the lifetime distribution can significantly affect the estimation of the failure rate of a product. Moreover, sampling costs, inspection costs, warranty costs, and rejection costs are all essential, and ought to be considered in choosing an appropriate sampling plan. The choice of an appropriate life test sampling plan is a crucial decision problem because a good plan not only can help producers save testing time, and reduce testing cost; but it also can positively affect the image of the product, and thus attract more consumers to buy it. This paper develops the frequentist (non-Bayesian) decision models for determining the optimal life test sampling plans with an aim of cost minimization by identifying the appropriate number of product failures in a sample that should be used as a threshold in judging the rejection of a batch. The two-parameter exponential and Weibull distributions with two unknown parameters are assumed to be appropriate for modelling the lifetime of a product. A practical numerical application is employed to demonstrate the proposed approach.

EOS-AM1 Nickel Hydrogen Cell Interim Life Test Report

NASA Technical Reports Server (NTRS)

Bennett, C. W.; Keys, D. J.; Rao, G. M.; Wannemacher, H. E.; Vaidyanathan, H.

1997-01-01

This paper reports the interim results of the Earth Observing System AM-1 project (EOS-AM-1) nickel hydrogen cell life test being conducted under contract to National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) at the Lockheed Martin Missiles and Space (LMMS) facility in East Windsor, NJ; and at COMSAT Labs., Clarksburg, MD. The purpose of the tests is to verify that the EOS-AM-l cell design can meet five years of real-time Low Earth Orbit (LEO) cycling. The tests include both real-time LEO and accelerated stress tests. At LMMS, the first real-time LEO simulated 99 minute orbital cycle started on February 7, 1994 and the test has been running continuously since that time, with 13000 LEO cycles completed as of September 2, 1996. Each cycle consists of a 64 minute charge (VT at 1.507 volts per cell, 1.06 C/D ratio, followed by 0.6 ampere trickle charge) and a 35 minute constant power discharge at 177 watts (22.5% DOD). At COMSAT, the accelerated stress test consists of 90 minute orbital cycles at 60% DOD with a 30 minute discharge at 60 amperes and a 60 minute charge at 40 ampercs (VT at 1.54 volts per cell to 1.09 C/D ratio, followed by 0.6 ampere trickle charge). The real-time LEO life test battery consists of seven, 50AH (nameplate rating) Eagle-Picher, Inc. (EPI) Mantech cells manufactured into three, 3-cell pack assemblies (there are two place holder cells that are not part of the life test electrical circuit). The test pack is configured to simulate the conductive thermal design of the spacecraft battely, including: conductive aluminum sleeves, 3-cell pack aluminum baseplate, and honeycomb panel all mounted to a liquid (-5 C) cold plate. The entire assembly is located in a thermal chamber operating at +3 C. The accelerated stress test unit consists of five cells mounted in machined aluminum test sleeves and is operating at +10 C. The real-time LEO life test battery has met all performance requirements through the first 13

Life Test Approach for Refractory Metal/Sodium Heat Pipes

NASA Astrophysics Data System (ADS)

Martin, James J.; Reid, Robert S.

2006-01-01

Heat pipe life tests described in the literature have seldom been conducted on a systematic basis. Typically one or more heat pipes are built and tested for an extended period at a single temperature with simple condenser loading. The objective of this work was to establish an approach to generate carefully controlled data that can conclusively establish heat pipe operating life with material-fluid combinations capable of extended operation. Approximately 10 years of operational life might be compressed into 3 years of laboratory testing through a combination of increased temperature and mass fluence. To accomplish this goal test series have been identified, based on American Society for Testing and Materials (ASTM) specifications, to investigate long term corrosion rates. The heat pipes selected for demonstration purposes are fabricated from a Molybdenum-44.5%Rhenium refractory metal alloy and include an internal crescent annular wick design formed by hot isostatic pressing. A processing methodology has been devised that incorporates vacuum distillation filling with an integrated purity sampling technique for the sodium working fluid. Energy is supplied by radio frequency induction coils coupled to the heat pipe evaporator with an input range of 1 to 5 kW per unit while a static gas gap coupled water calorimeter provides condenser cooling for heat pipe temperatures ranging from 1123 to 1323 K. The test chamber's atmosphere would require active purification to maintain low oxygen concentrations at an operating pressure of approximately 75 torr. The test is designed to operate round-the-clock with 6-month non-destructive inspection intervals to identify the onset and level of corrosion. At longer intervals specific heat pipes are destructively evaluated to verify the non-destructive observations. Accomplishments prior to project cancellation included successful demonstration of the heat pipe wick fabrication technique, establishment of all engineering designs

Fatigue life prediction of liquid rocket engine combustor with subscale test verification

NASA Astrophysics Data System (ADS)

Sung, In-Kyung

Reusable rocket systems such as the Space Shuttle introduced a new era in propulsion system design for economic feasibility. Practical reusable systems require an order of magnitude increase in life. To achieve this improved methods are needed to assess failure mechanisms and to predict life cycles of rocket combustor. A general goal of the research was to demonstrate the use of subscale rocket combustor prototype in a cost-effective test program. Life limiting factors and metal behaviors under repeated loads were surveyed and reviewed. The life prediction theories are presented, with an emphasis on studies that used subscale test hardware for model validation. From this review, low cycle fatigue (LCF) and creep-fatigue interaction (ratcheting) were identified as the main life limiting factors of the combustor. Several life prediction methods such as conventional and advanced viscoplastic models were used to predict life cycle due to low cycle thermal stress, transient effects, and creep rupture damage. Creep-fatigue interaction and cyclic hardening were also investigated. A prediction method based on 2D beam theory was modified using 3D plate deformation theory to provide an extended prediction method. For experimental validation two small scale annular plug nozzle thrusters were designed, built and tested. The test article was composed of a water-cooled liner, plug annular nozzle and 200 psia precombustor that used decomposed hydrogen peroxide as the oxidizer and JP-8 as the fuel. The first combustor was tested cyclically at the Advanced Propellants and Combustion Laboratory at Purdue University. Testing was stopped after 140 cycles due to an unpredicted failure mechanism due to an increasing hot spot in the location where failure was predicted. A second combustor was designed to avoid the previous failure, however, it was over pressurized and deformed beyond repair during cold-flow test. The test results are discussed and compared to the analytical and numerical

Evaluation program for secondary spacecraft cells: Cycle life test

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1979-01-01

The service life and storage stability for several storage batteries were determined. The batteries included silver-zinc batteries, nickel-cadmium batteries, and silver-cadmium batteries. The cell performance characteristics and limitations are to be used by spacecraft power systems planners and designers. A statistical analysis of the life cycle prediction and cause of failure versus test conditions is presented.

Generic versus branded medicines: An observational study among patients with chronic diseases attending a public hospital outpatient department

PubMed Central

Das, Manisha; Choudhury, Supriyo; Maity, Somnath; Hazra, Avijit; Pradhan, Tirthankar; Pal, Aishee; Roy, Ranendra Kumar

2017-01-01

Background: The concept of generic prescription is widely accepted in various parts of the world. Nevertheless, it has failed to gain popularity in India due to factors such as nonavailability and distrust on the product quality. However, since 2012, the Government of West Bengal, India, has initiated exclusive generic drug outlets called “fair price medicine shop” (FPMS) inside the government hospital premises in a “public-private-partnership” model. This study was undertaken to evaluate the experience and attitude of patients who were consuming generic drugs purchased from these FPMS. Materials and Methods: It was a questionnaire-based cross-sectional study where we have interviewed 100 patients each consuming generic and branded drugs, respectively. The perceived effectiveness, reported safety, medication adherence, cost of therapy, and availability of drugs was compared between two mentioned groups. Medication adherence was estimated through Drug Attitude Inventory-10. Results: 93% of generic and 87% branded drug users believed that their drugs were effective (P = 0.238) in controlling their ailments. No significant difference (9% generic, 10% branded drug users, P = 1.000) was observed in reported adverse effects between generic and branded drug users. 82% and 77% of patients were adherent generic and branded drugs, respectively (P = 0.289). As expected, a significantly lower cost of generic drugs was observed compared to its branded counterpart. Conclusion: The policy of FPMS implemented by the Government of West Bengal, India appeared to be promising in terms of perceived effectiveness, safety, and adherence of generic drugs from FPMS compared to drugs purchased from open market retailers. Therefore, this study might act as an impetus for the policy-makers to initiate similar models across the country. PMID:28250671

Long life monopropellant hydrazine thruster evaluation for Space Station Freedom application - Test results

NASA Technical Reports Server (NTRS)

Popp, Christopher G.; Cook, Joseph C.; Ragland, Brenda L.; Pate, Leah R.

1992-01-01

In support of propulsion system thruster development activity for Space Station Freedom (SSF), NASA Johnson Space Center (JSC) conducted a hydrazine thruster technology demonstration program. The goal of this program was to identify impulse life capability of state-of-the-art long life hydrazine thrusters nominally rated for 50 pounds thrust at 300 psia supply pressure. The SSF propulsion system requirement for impulse life of this thruster class is 1.5 million pounds-seconds, corresponding to a throughput of approximately 6400 pounds of propellant. Long life thrusters were procured from The Marquardt Company, Hamilton Standard, and Rocket Research Company, Testing at JSC was completed on the thruster designs to quantify life while simulating expected thruster firing duty cycles and durations for SSF. This paper presents a review of the SSF propulsion system hydrazine thruster requirements, summaries of the three long life thruster designs procured by JSC and acceptance test results for each thruster, the JSC thruster life evaluation test program, and the results of the JSC test program.

Space Suit Portable Life Support System Test Bed (PLSS 1.0) Development and Testing

NASA Technical Reports Server (NTRS)

Watts, Carly; Campbell, Colin; Vogel, Matthew; Conger, Bruce

2012-01-01

A multi-year effort has been carried out at NASA-JSC to develop an advanced extra-vehicular activity Portable Life Support System (PLSS) design intended to further the current state of the art by increasing operational flexibility, reducing consumables, and increasing robustness. Previous efforts have focused on modeling and analyzing the advanced PLSS architecture, as well as developing key enabling technologies. Like the current International Space Station Extra-vehicular Mobility Unit PLSS, the advanced PLSS comprises three subsystems required to sustain the crew during extra-vehicular activity including the Thermal, Ventilation, and Oxygen Subsystems. This multi-year effort has culminated in the construction and operation of PLSS 1.0, a test bed that simulates full functionality of the advanced PLSS design. PLSS 1.0 integrates commercial off the shelf hardware with prototype technology development components, including the primary and secondary oxygen regulators, Ventilation Subsystem fan, Rapid Cycle Amine swingbed carbon dioxide and water vapor removal device, and Spacesuit Water Membrane Evaporator heat rejection device. The overall PLSS 1.0 test objective was to demonstrate the capability of the Advanced PLSS to provide key life support functions including suit pressure regulation, carbon dioxide and water vapor removal, thermal control and contingency purge operations. Supplying oxygen was not one of the specific life support functions because the PLSS 1.0 test was not oxygen rated. Nitrogen was used for the working gas. Additional test objectives were to confirm PLSS technology development components performance within an integrated test bed, identify unexpected system level interactions, and map the PLSS 1.0 performance with respect to key variables such as crewmember metabolic rate and suit pressure. Successful PLSS 1.0 testing completed 168 test points over 44 days of testing and produced a large database of test results that characterize system level

Traveling-wave tube reliability estimates, life tests, and space flight experience

NASA Technical Reports Server (NTRS)

Lalli, V. R.; Speck, C. E.

1977-01-01

Infant mortality, useful life, and wearout phase of twt life are considered. The performance of existing developmental tubes, flight experience, and sequential hardware testing are evaluated. The reliability history of twt's in space applications is documented by considering: (1) the generic parts of the tube in light of the manner in which their design and operation affect the ultimate reliability of the device, (2) the flight experience of medium power tubes, and (3) the available life test data for existing space-qualified twt's in addition to those of high power devices.

Earth Scanner Bearing Accelerated Life Test

NASA Technical Reports Server (NTRS)

Dietz, Brian J.; VanDyk, Steven G.; Predmore, Roamer E.

2000-01-01

The Moderate Resolution Imaging Spectrometer (MODIS) optical instrument for NASA Goddard will measure biological and physical processes on the Earth's surface and in the lower atmosphere. A key component of the instrument is an extremely accurate scan mirror motor/encoder assembly. Of prime concern in the performance and reliability of the scan motor/encoder is bearing selection and lubrication. This paper describes life testing of the bearings and lubrication selected for the program.

Definition study for an extended manned test of a regenerative life support system

NASA Technical Reports Server (NTRS)

1971-01-01

A program was defined which consists of extended ground-based manned tests of regenerative life support systems. The tests are to evaluate prototypes of advanced life support systems under operational, integrated conditions, thus providing data for the design of efficient environmental control and life support systems for use in long-duration space missions. The requirements are defined for test operations to provide a simulation of an orbiting space laboratory. The features of Phase A and B programs are described. These tests use proven backup equipment to ensure successful evaluation of the advanced subsystems. A pre-tests all-systems checkout period is provided to minimize equipment problems during extended testing and to familiarize all crew and operating staff members with test equipment and procedures.

40 CFR 797.1600 - Fish early life stage toxicity test.

Code of Federal Regulations, 2013 CFR

2013-07-01

... dilution water or the test solution. (4) “Control” an exposure of test organisms to dilution water only or... (treatment) concentrations of a test substance and one control are required to conduct an early life stage... trays or cups for each test concentration and control (i.e., 30 per embryo cup with 2 replicates); (C...

40 CFR 797.1600 - Fish early life stage toxicity test.

Code of Federal Regulations, 2010 CFR

2010-07-01

... dilution water or the test solution. (4) “Control” an exposure of test organisms to dilution water only or... (treatment) concentrations of a test substance and one control are required to conduct an early life stage... trays or cups for each test concentration and control (i.e., 30 per embryo cup with 2 replicates); (C...

40 CFR 797.1600 - Fish early life stage toxicity test.

Code of Federal Regulations, 2012 CFR

2012-07-01

... dilution water or the test solution. (4) “Control” an exposure of test organisms to dilution water only or... (treatment) concentrations of a test substance and one control are required to conduct an early life stage... trays or cups for each test concentration and control (i.e., 30 per embryo cup with 2 replicates); (C...

Environmental Control and Life Support Systems Test Facility at MSFC

NASA Technical Reports Server (NTRS)

2001-01-01

The Marshall Space Flight Center (MSFC) is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. Scientists and engineers at the MSFC are working together to provide the ISS with systems that are safe, efficient, and cost-effective. These compact and powerful systems are collectively called the Environmental Control and Life Support Systems, or simply, ECLSS. In this photograph, the life test area on the left of the MSFC ECLSS test facility is where various subsystems and components are tested to determine how long they can operate without failing and to identify components needing improvement. Equipment tested here includes the Carbon Dioxide Removal Assembly (CDRA), the Urine Processing Assembly (UPA), the mass spectrometer filament assemblies and sample pumps for the Major Constituent Analyzer (MCA). The Internal Thermal Control System (ITCS) simulator facility (in the module in the right) duplicates the function and operation of the ITCS in the ISS U.S. Laboratory Module, Destiny. This facility provides support for Destiny, including troubleshooting problems related to the ITCS.

Regenerative Life Support Systems Test Bed performance - Lettuce crop characterization

NASA Technical Reports Server (NTRS)

Barta, Daniel J.; Edeen, Marybeth A.; Eckhardt, Bradley D.

1992-01-01

System performance in terms of human life support requirements was evaluated for two crops of lettuce (Lactuca sative cv. Waldmann's Green) grown in the Regenerative Life Support Systems Test Bed. Each crop, grown in separate pots under identical environmental and cultural conditions, was irrigated with half-strength Hoagland's nutrient solution, with the frequency of irrigation being increased as the crop aged over the 30-day crop tests. Averaging over both crop tests, the test bed met the requirements of 2.1 person-days of oxygen production, 2.4 person-days of CO2 removal, and 129 person-days of potential potable water production. Gains in the mass of water and O2 produced and CO2 removed could be achieved by optimizing environmental conditions to increase plant growth rate and by optimizing cultural management methods.

The Clouds and the Earth's Radiant Energy System Elevation Bearing Assembly Life Test

NASA Technical Reports Server (NTRS)

Brown, Phillip L.; Miller, James B.; Jones, William R., Jr.; Rasmussen, Kent; Wheeler, Donald R.; Rana, Mauro; Peri, Frank

1999-01-01

The Clouds and the Earth's Radiant Energy System (CERES) elevation scan bearings lubricated with Pennzane SHF X2000 and 2% lead naphthenate (PbNp) were life tested for a seven-year equivalent Low Earth Orbit (LEO) operation. The bearing life assembly was tested continuously at an accelerated and normal rate using the scanning patterns developed for the CERES Earth Observing System AM-1 mission. A post-life-test analysis was performed on the collected data, bearing wear, and lubricant behavior.

Determination of Rolling-Element Fatigue Life From Computer Generated Bearing Tests

NASA Technical Reports Server (NTRS)

Vlcek, Brian L.; Hendricks, Robert C.; Zaretsky, Erwin V.

2003-01-01

Two types of rolling-element bearings representing radial loaded and thrust loaded bearings were used for this study. Three hundred forty (340) virtual bearing sets totaling 31400 bearings were randomly assembled and tested by Monte Carlo (random) number generation. The Monte Carlo results were compared with endurance data from 51 bearing sets comprising 5321 bearings. A simple algebraic relation was established for the upper and lower L(sub 10) life limits as function of number of bearings failed for any bearing geometry. There is a fifty percent (50 percent) probability that the resultant bearing life will be less than that calculated. The maximum and minimum variation between the bearing resultant life and the calculated life correlate with the 90-percent confidence limits for a Weibull slope of 1.5. The calculated lives for bearings using a load-life exponent p of 4 for ball bearings and 5 for roller bearings correlated with the Monte Carlo generated bearing lives and the bearing data. STLE life factors for bearing steel and processing provide a reasonable accounting for differences between bearing life data and calculated life. Variations in Weibull slope from the Monte Carlo testing and bearing data correlated. There was excellent agreement between percent of individual components failed from Monte Carlo simulation and that predicted.

Special environmental control and life support equipment test analyses and hardware

NASA Technical Reports Server (NTRS)

Callahan, David M.

1995-01-01

This final report summarizes NAS8-38250 contract events, 'Special Environmental Control and Life Support Systems Test Analysis and Hardware'. This report is technical and includes programmatic development. Key to the success of this contract was the evaluation of Environmental Control and Life Support Systems (ECLSS) test results via sophisticated laboratory analysis capabilities. The history of the contract, including all subcontracts, is followed by the support and development of each Task.

Test Population Selection from Weibull-Based, Monte Carlo Simulations of Fatigue Life

NASA Technical Reports Server (NTRS)

Vlcek, Brian L.; Zaretsky, Erwin V.; Hendricks, Robert C.

2008-01-01

Fatigue life is probabilistic and not deterministic. Experimentally establishing the fatigue life of materials, components, and systems is both time consuming and costly. As a result, conclusions regarding fatigue life are often inferred from a statistically insufficient number of physical tests. A proposed methodology for comparing life results as a function of variability due to Weibull parameters, variability between successive trials, and variability due to size of the experimental population is presented. Using Monte Carlo simulation of randomly selected lives from a large Weibull distribution, the variation in the L10 fatigue life of aluminum alloy AL6061 rotating rod fatigue tests was determined as a function of population size. These results were compared to the L10 fatigue lives of small (10 each) populations from AL2024, AL7075 and AL6061. For aluminum alloy AL6061, a simple algebraic relationship was established for the upper and lower L10 fatigue life limits as a function of the number of specimens failed. For most engineering applications where less than 30 percent variability can be tolerated in the maximum and minimum values, at least 30 to 35 test samples are necessary. The variability of test results based on small sample sizes can be greater than actual differences, if any, that exists between materials and can result in erroneous conclusions. The fatigue life of AL2024 is statistically longer than AL6061 and AL7075. However, there is no statistical difference between the fatigue lives of AL6061 and AL7075 even though AL7075 had a fatigue life 30 percent greater than AL6061.

Test Population Selection from Weibull-Based, Monte Carlo Simulations of Fatigue Life

NASA Technical Reports Server (NTRS)

Vlcek, Brian L.; Zaretsky, Erwin V.; Hendricks, Robert C.

2012-01-01

Fatigue life is probabilistic and not deterministic. Experimentally establishing the fatigue life of materials, components, and systems is both time consuming and costly. As a result, conclusions regarding fatigue life are often inferred from a statistically insufficient number of physical tests. A proposed methodology for comparing life results as a function of variability due to Weibull parameters, variability between successive trials, and variability due to size of the experimental population is presented. Using Monte Carlo simulation of randomly selected lives from a large Weibull distribution, the variation in the L10 fatigue life of aluminum alloy AL6061 rotating rod fatigue tests was determined as a function of population size. These results were compared to the L10 fatigue lives of small (10 each) populations from AL2024, AL7075 and AL6061. For aluminum alloy AL6061, a simple algebraic relationship was established for the upper and lower L10 fatigue life limits as a function of the number of specimens failed. For most engineering applications where less than 30 percent variability can be tolerated in the maximum and minimum values, at least 30 to 35 test samples are necessary. The variability of test results based on small sample sizes can be greater than actual differences, if any, that exists between materials and can result in erroneous conclusions. The fatigue life of AL2024 is statistically longer than AL6061 and AL7075. However, there is no statistical difference between the fatigue lives of AL6061 and AL7075 even though AL7075 had a fatigue life 30 percent greater than AL6061.

Quantitative Accelerated Life Testing of MEMS Accelerometers

PubMed Central

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

2007-01-01

Quantitative Accelerated Life Testing (QALT) is a solution for assessing the reliability of Micro Electro Mechanical Systems (MEMS). A procedure for QALT is shown in this paper and an attempt to assess the reliability level for a batch of MEMS accelerometers is reported. The testing plan is application-driven and contains combined tests: thermal (high temperature) and mechanical stress. Two variants of mechanical stress are used: vibration (at a fixed frequency) and tilting. Original equipment for testing at tilting and high temperature is used. Tilting is appropriate as application-driven stress, because the tilt movement is a natural environment for devices used for automotive and aerospace applications. Also, tilting is used by MEMS accelerometers for anti-theft systems. The test results demonstrated the excellent reliability of the studied devices, the failure rate in the “worst case” being smaller than 10-7h-1. PMID:28903265

Intermediate Temperature Fluids Life Tests - Experiments

DTIC Science & Technology

2007-06-01

TiCl4, TiBr4, and eutectic diphenyl/diphenyl oxide (Therminol VP-1/Dowtherm A). All of the life tests except for the GaCl3 are ongoing; the GaCl3...763 85.5 Eutectic Diphenyl/Diphenyl Oxide 285 530 770 31 Antimony Tribromide SbBr3 370 553 1178 55 Antimony Trichloride SbCl3 346 556 794 Cesium...From a Compatibility Standpoint) Have High Decomposition Potentials, While Halides/ Salts of Good Envelope Materials Have Low Decomposition Potentials

Overview of the Environmental Control and Life Support System (ECLSS) Testing At MSFC

NASA Technical Reports Server (NTRS)

Traweek, Mary S.; Tatara, James D.

1998-01-01

Previously, almost all water used by the crew during space flight has been transported from earth or generated in-flight as a by-product of fuel cells. Additionally, this water has been stored and used for relatively short periods. To achieve the United States' commitment to a permanent manned presence in space, more innovative techniques are demanded. Over 20,000 pounds of water and large quantities of air would have to be transported to the International Space Station (ISS) every 90 days with a corresponding amount of waste returned to earth, for an 8-person crew. This approach results in prohibitive logistics costs, and necessitates near complete recovery and recycling of water. The potential hazards associated with long-term reuse of reclaimed water and revitalized air resulted in the recognition that additional characterization of closed-loop systems and products is essential. Integrated physical/chemical systems have been designed, assembled, and operated to provide air and potable water meeting ISS quality specifications. The purpose of the Environmental Control and Life Support System (ECLSS) test program at NASA's Marshall Space Flight Center is to conduct research related to the performance of the ISS and its Environmental Control components. The ECLSS Test Program encompasses the Water Recovery Test (WRT), the Integrated Air Revitalization Test (IART), and Life Testing, which permits ECLSS design evaluation. These subsystems revitalize air and reclaim waste waters representative of those to be generated on-orbit. This paper provides an overview of MSFC's 1997 ECLSS testing. Specific tests include: the Stage 10 Water Recovery Test; the Contaminant Injection Test; the Performance Enhancement Test and Life Testing of the Four Bed Molecular Sieve; the Oxygen Generator Assembly Life Test; and the ISS Water Distribution Biofilm Life Test.

Should Australia Ban the Use of Genetic Test Results in Life Insurance?

PubMed

Tiller, Jane; Otlowski, Margaret; Lacaze, Paul

2017-01-01

Under current Australian regulation, life insurance companies can require applicants to disclose all genetic test results, including results from research or direct-to-consumer tests. Life insurers can then use this genetic information in underwriting and policy decisions for mutually rated products, including life, permanent disability, and total income protection insurance. Over the past decade, many countries have implemented moratoria or legislative bans on the use of genetic information by life insurers. The Australian government, by contrast, has not reviewed regulation since 2005 when it failed to ensure implementation of recommendations made by the Australian Law Reform Commission. In that time, the Australian life insurance industry has been left to self-regulate its use of genetic information. As a result, insurance fears in Australia now are leading to deterred uptake of genetic testing by at-risk individuals and deterred participation in medical research, both of which have been documented. As the potential for genomic medicine grows, public trust and engagement are critical for successful implementation. Concerns around life insurance may become a barrier to the development of genomic health care, research, and public health initiatives in Australia, and the issue should be publicly addressed. We argue a moratorium on the use of genetic information by life insurers should be enacted while appropriate longer term policy is determined and implemented.

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

NASA Technical Reports Server (NTRS)

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

2004-01-01

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

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

NASA Technical Reports Server (NTRS)

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

2006-01-01

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

Active matrix organic light emitting diode (OLED)-XL life test results

NASA Astrophysics Data System (ADS)

Fellowes, David A.; Wood, Michael V.; Hastings, Arthur R., Jr.; Ghosh, Amalkumar P.; Prache, Olivier

2008-04-01

OLED displays have been known to exhibit high levels of performance with regards to contrast, response time, uniformity, and viewing angle, but a lifetime improvement has been perceived to be essential for broadening the applications of OLED's in the military and in the commercial market. As a result of this need, the US Army and eMagin Corporation established a Cooperative Research and Development Agreement (CRADA) to improve the lifetime of OLED displays. In 2006, eMagin Corporation developed long-life OLED-XL devices for use in their AMOLED microdisplays for head-worn applications, and RDECOM CERDEC NVESD ran life tests on these displays, finding over 200% lifetime improvement for the XL devices over the standard displays. Early results were published at the 2007 SPIE Defense and Security Symposium. Further life testing of XL and standard devices at ambient conditions and at high temperatures will be presented this year along with a recap of previous data. This should result in a better understanding of the applicability of AMOLEDs in military and commercial head mounted systems: where good fits are made, and where further development might be needed. This is a continuation of the paper "Life test results of OLED-XL long-life devices for use in active matrix organic light emitting diode (AMOLED) displays for head mounted applications" presented at SPIE DSS in 2007.

Quantitative Accelerated Life Testing of MEMS Accelerometers.

PubMed

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 .

X-43A Rudder Spindle Fatigue Life Estimate and Testing

NASA Technical Reports Server (NTRS)

Glaessgen, Edward H.; Dawicke, David S.; Johnston, William M.; James, Mark A.; Simonsen, Micah; Mason, Brian H.

2005-01-01

Fatigue life analyses were performed using a standard strain-life approach and a linear cumulative damage parameter to assess the effect of a single accidental overload on the fatigue life of the Haynes 230 nickel-base superalloy X-43A rudder spindle. Because of a limited amount of information available about the Haynes 230 material, a series of tests were conducted to replicate the overload and in-service conditions for the spindle and corroborate the analysis. Both the analytical and experimental results suggest that the spindle will survive the anticipated flight loads.

Results of Long Term Life Tests of Large Scale Lithium-Ion Cells

NASA Astrophysics Data System (ADS)

Inoue, Takefumi; Imamura, Nobutaka; Miyanaga, Naozumi; Yoshida, Hiroaki; Komada, Kanemi

2008-09-01

High energy density Li-ion cells have been introduced to latest satellites and another space usage. We have started development of large scale Li-ion cells for space applications in 1997. The chemical design was fixed in 1999.It is very important to confirm life performance to apply satellite applications because it requires long mission life such as 15 years for GEO and 5 to 7 years for LEO. Therefore we started life test at various conditions. And the tests have reached 8 to 9 years in actual calendar time. Semi - accelerated GEO tests which gives both calendar and cycle loss have been reached 42 season that corresponds 21 years in orbit. The specific energy range is 120 - 130 Wh/kg at EOL. According to the test results, we have confirmed that our Li-ion cell meets general requirements for space application such as GEO and LEO with quite high specific energy.

Simulating advanced life support systems to test integrated control approaches

NASA Astrophysics Data System (ADS)

Kortenkamp, D.; Bell, S.

Simulations allow for testing of life support control approaches before hardware is designed and built. Simulations also allow for the safe exploration of alternative control strategies during life support operation. As such, they are an important component of any life support research program and testbed. This paper describes a specific advanced life support simulation being created at NASA Johnson Space Center. It is a discrete-event simulation that is dynamic and stochastic. It simulates all major components of an advanced life support system, including crew (with variable ages, weights and genders), biomass production (with scalable plantings of ten different crops), water recovery, air revitalization, food processing, solid waste recycling and energy production. Each component is modeled as a producer of certain resources and a consumer of certain resources. The control system must monitor (via sensors) and control (via actuators) the flow of resources throughout the system to provide life support functionality. The simulation is written in an object-oriented paradigm that makes it portable, extensible and reconfigurable.

Vapor Compression Distillation Urine Processor Lessons Learned from Development and Life Testing

NASA Technical Reports Server (NTRS)

Hutchens, Cindy F.; Long, David A.

1999-01-01

Vapor Compression Distillation (VCD) is the chosen technology for urine processing aboard the International Space Station (155). Development and life testing over the past several years have brought to the forefront problems and solutions for the VCD technology. Testing between 1992 and 1998 has been instrumental in developing estimates of hardware life and reliability. It has also helped improve the hardware design in ways that either correct existing problems or enhance the existing design of the hardware. The testing has increased the confidence in the VCD technology and reduced technical and programmatic risks. This paper summarizes the test results and changes that have been made to the VCD design.

Phase Change Material Heat Exchanger Life Test

NASA Technical Reports Server (NTRS)

Lillibridge, Sean; Stephan, Ryan; Lee, Steve; He, Hung

2008-01-01

Low Lunar Orbit (LLO) poses unique thermal challenges for the orbiting space craft, particularly regarding the performance of the radiators. The emitted infrared (IR) heat flux from the lunar surface varies drastically from the light side to the dark side of the moon. Due to the extremely high incident IR flux, especially at low beta angles, a radiator is oftentimes unable to reject the vehicle heat load throughout the entire lunar orbit. One solution to this problem is to implement Phase Change Material (PCM) Heat Exchangers. PCM Heat Exchangers act as a "thermal capacitor," storing thermal energy when the radiator is unable to reject the required heat load. The stored energy is then removed from the PCM heat exchanger when the environment is more benign. Because they do not use an expendable resource, such as the feed water used by sublimators and evaporators, PCM Heat Exchangers are ideal for long duration Low Lunar Orbit missions. The Advanced Thermal Control project at JSC is completing a PCM heat exchanger life test to determine whether further technology development is warranted. The life test is being conducted on four nPentadecane, carbon filament heat exchangers. Fluid loop performance, repeatability, and measurement of performance degradation over 2500 melt-freeze cycles will be performed and reported in the current document.

Refractory Metal Heat Pipe Life Test - Test Plan and Standard Operating Procedures

NASA Technical Reports Server (NTRS)

Martin, J. J.; Reid, R. S.

2010-01-01

Refractory metal heat pipes developed during this project shall be subjected to various operating conditions to evaluate life-limiting corrosion factors. To accomplish this objective, various parameters shall be investigated, including the effect of temperature and mass fluence on long-term corrosion rate. The test series will begin with a performance test of one module to evaluate its performance and to establish the temperature and power settings for the remaining modules. The performance test will be followed by round-the-clock testing of 16 heat pipes. All heat pipes shall be nondestructively inspected at 6-month intervals. At longer intervals, specific modules will be destructively evaluated. Both the nondestructive and destructive evaluations shall be coordinated with Los Alamos National Laboratory. During the processing, setup, and testing of the heat pipes, standard operating procedures shall be developed. Initial procedures are listed here and, as hardware is developed, will be updated, incorporating findings and lessons learned.

Purpose-in-Life Test: Comparison of the Main Models in Patients with Mental Disorders.

PubMed

García-Alandete, Joaquín; Marco, José H; Pérez, Sandra

2017-06-27

The aim of this study was to compare the main proposed models for the Purpose-In-Life Test, a scale for assessing meaning in life, in 229 Spanish patients with mental disorders (195 females and 34 males, aged 13-68, M = 34.43, SD = 12.19). Confirmatory factor-analytic procedures showed that the original model of the Purpose-In-Life Test, a 20-item unidimensional scale, obtained a better fit than the other analyzed models, SBχ2(df) = 326.27(170), SBχ2/df = 1.92, TLI = .93, CFI = .94, IFI = .94, RMSEA = .063 (90% CI [.053, .074]), CAIC = -767.46, as well as a high internal consistency, (α = .90). The main conclusion is that the original version of the Purpose-In-Life shows a robust construct validity in a clinical population. However, authors recommend an in-depth psychometric analysis of the Purpose-In-Life Test among clinical population. Likewise, the importance of assessing meaning in life in order to enhance psychotherapeutic treatment is noted.

Life test results for the advanced very high resolution radiometer scanner

NASA Technical Reports Server (NTRS)

Lenz, James

1996-01-01

The following paper reports the results obtained during a 3.33-year life test on the TIROS Advanced Very High Resolution Radiometer/3 (AVHRR/3) Scanner. The bearing drag torque and lubricant loss over life will be compared to predicted values developed through modeling. The condition of the lubricant at the end of the test will be described and a theory presented to explain the results obtained. The differences (if any) in the predicted and measured values of drag torque and lubricant loss will be discussed and possible reasons for these examined.

Closure of Regenerative Life Support Systems: Results of the Lunar-Mars Life Support Test Project

NASA Technical Reports Server (NTRS)

Barta, Daniel; Henninger, D.; Edeen, M.; Lewis, J.; Smth, F.; Verostko, C.

2006-01-01

Future long duration human exploration missions away from Earth will require closed-loop regenerative life support systems to reduce launch mass, reduce dependency on resupply and increase the level of mission self sufficiency. Such systems may be based on the integration of biological and physiocochemical processes to produce potable water, breathable atmosphere and nutritious food from metabolic and other mission wastes. Over the period 1995 to 1998 a series of ground-based tests were conducted at the National Aeronautics and Space Administration, Johnson Space Center, to evaluate the performance of advanced closed-loop life support technologies with real human metabolic and hygiene loads. Named the Lunar-Mars Life Support Test Project (LMLSTP), four integrated human tests were conducted with increasing duration, complexity and closure. The first test, LMLSTP Phase I, was designed to demonstrate the ability of higher plants to revitalize cabin atmosphere. A single crew member spent 15 days within an atmospherically closed chamber containing 11.2 square meters of actively growing wheat. Atmospheric carbon dioxide and oxygen levels were maintained by control of the rate of photosynthesis through manipulation of light intensity or the availability of carbon dioxide and included integrated physicochemical systems. During the second and third tests, LMLSTP Phases II & IIa, four crew members spent 30 days and 60 days, respectively, in a larger sealed chamber. Advanced physicochemical life support hardware was used to regenerate the atmosphere and produce potable water from wastewater. Air revitalization was accomplished by using a molecular sieve and a Sabatier processor for carbon dioxide absorption and reduction, respectively, with oxygen generation performed by water hydrolysis. Production of potable water from wastewater included urine treatment (vapor compression distillation), primary treatment (ultrafiltration/reverse osmosis and multi-filtration) and post

Closeout Report for the Refractory Metal Accelerated Heat Pipe Life Test Activity

NASA Technical Reports Server (NTRS)

Martin, J.; Reid, R.; Stewart, E.; Hickman, R.; Mireles, O.

2013-01-01

With the selection of a gas-cooled reactor, this heat pipe accelerated life test activity was closed out and its resources redirected. The scope of this project was to establish the long-term aging effects on Mo-44.5%Re sodium heat pipes when subjected to space reactor temperature and mass fluences. To date, investigators have demonstrated heat pipe life tests of alkali metal systems up to .50,000 hours. Unfortunately, resources have not been available to examine the effect of temperature, mass fluence, or impurity level on corrosion or to conduct post-test forensic examination of heat pipes. The key objective of this effort was to establish a cost/time effective method to systematically test alkali metal heat pipes with both practical and theoretical benefits. During execution of the project, a heat pipe design was established, a majority of the laboratory test equipment systems specified, and operating and test procedures developed. Procurements for the heat pipe units and all major test components were underway at the time the stop work order was issued. An extremely important outcome was the successful fabrication of an annular wick from Mo-5%Re screen (the single, most difficult component to manufacture) using a hot isostatic pressing technique. This Technical Publication (TP) includes specifics regarding the heat pipe calorimeter water-cooling system, vendor design for the radio frequency heating system, possible alternative calorimeter designs, and progress on the vanadium equilibration technique. The methods provided in this TP and preceding project documentation would serve as a good starting point to rapidly implement an accelerated life test. Relevant test data can become available within months, not years, and destructive examination of the first life test heat pipe might begin within 6 months of test initiation. Final conclusions could be drawn in less than a quarter of the mission duration for a long-lived, fission-powered, deep space probe.

Human in the Loop Integrated Life Support Systems Ground Testing

NASA Technical Reports Server (NTRS)

Henninger, Donald L.; Marmolejo, Jose A.; Seaman, Calvin H.

2012-01-01

Human exploration missions beyond low earth orbit will be long duration with abort scenarios of days to months. This necessitates provisioning the crew with all the things they will need to sustain themselves while carrying out mission objectives. Systems engineering and integration is critical to the point where extensive integrated testing of life support systems on the ground is required to identify and mitigate risks. Ground test facilities (human-rated altitude chambers) at the Johnson Space Center are being readied to integrate all the systems for a mission along with a human test crew. The relevant environment will include deep space habitat human accommodations, sealed atmosphere capable of 14.7 to 8 psi total pressure and 21 to 32% oxygen concentration, life support systems (food, air, and water), communications, crew accommodations, medical, EVA, tools, etc. Testing periods will approximate those of the expected missions (such as a near Earth asteroid, Earth-Moon L2 or L1, the moon, Mars). This type of integrated testing is needed for research and technology development as well as later during the mission design, development, test, and evaluation (DDT&E) phases of an approved program. Testing will evolve to be carried out at the mission level fly the mission on the ground . Mission testing will also serve to inform the public and provide the opportunity for active participation by international, industrial and academic partners.

Human-in-the-Loop Integrated Life Support Systems Ground Testing

NASA Technical Reports Server (NTRS)

Henninger, Donald L.; Marmolejo, Jose A.; Westheimer, David T.

2011-01-01

Human exploration missions beyond low earth orbit will be long duration with abort scenarios of days to months. This necessitates provisioning the crew with all the things they will need to sustain themselves while carrying out mission objectives. Systems engineering and integration is critical to the point where extensive integrated testing of life support systems on the ground is required to identify and mitigate risks. Ground test facilities (human-rated altitude chamber) at the Johnson Space Center are being readied to integrate all the systems for a mission along with a human test crew. The relevant environment will include deep space habitat human accommodations, sealed atmosphere of 8 psi total pressure and 32% oxygen concentration, life support systems (food, air, water), communications, crew accommodations, medical, EVA, tools, etc. Testing periods will approximate those of the expected missions (such as a near Earth asteroid, Earth-Moon L2 or L1, the moon). This type of integrated testing is needed for research and technology development as well as later during the mission design, development, test, and evaluation (DDT&E) phases of an approved program. Testing will evolve to be carried out at the mission level fly the mission on the ground . Mission testing will also serve to inform the public and provide the opportunity for active participation by international partners.

Development of an alternative testing strategy for the fish early life-stage (FELS) test using the AOP framework

EPA Science Inventory

Currently, the fish early life-stage (FELS) test (OECD 210) is the primary guideline used to estimate chronic toxicity of regulated chemicals. Although already more cost-efficient than adult fish tests, the FELS test has some important drawbacks. Both industry and regulatory inst...

Testing and design life analysis of polyurea liner materials

NASA Astrophysics Data System (ADS)

Ghasemi Motlagh, Siavash

Certainly, water pipes, as part of an underground infrastructure system, play a key role in maintaining quality of life, health, and wellbeing of human kind. As these potable water pipes reach the end of their useful life, they create high maintenance costs, loss of flow capacity, decreased water quality, and increased dissatisfaction. There are several different pipeline renewal techniques available for different applications, among which linings are most commonly used for the renewal of water pipes. Polyurea is a lining material applied to the interior surface of the deteriorated host pipe using spray-on technique. It is applied to structurally enhance the host pipe and provide a barrier coating against further corrosion or deterioration. The purpose of this study was to establish a relationship between stress, strain and time. The results obtained from these tests were used in predicting the strength of the polyurea material during its planned 50-year design life. In addition to this, based on the 10,000 hours experimental data, curve fitting and Findley power law models were employed to predict long-term behavior of the material. Experimental results indicated that the tested polyurea material offers a good balance of strength and stiffness and can be utilized in structural enhancement applications of potable water pipes.

Safety and Abuse Testing of Energizer LiFeS2 AA Cells

NASA Technical Reports Server (NTRS)

Jeevarajan, Judith A.; Baldwin, Laura; Bragg, Bobby J.

2003-01-01

The LiFeS2 test program was part of the study on state-of-the-art batteries/cells available in the commercial market. It was carried out in an effort to replace alkaline AA cells for Shuttle and Station applications. A large number of alkaline cells are used for numerous Shuttle and Station applications as loose cells. Other government agencies reported good performance and abuse tolerance of the AA LiFeS2 cells. In this study, only abuse testing was performed on the cells to determine their tolerance. The tests carried out were over-discharge, external short circuit, heat-to-vent, vibration and drop.

Accelerated life testing effects on CMOS microcircuit characteristics, phase 1

NASA Technical Reports Server (NTRS)

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.

ESP – Data from Restarted Life Tests of Various Silicon Materials

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

Schneider, Jim

2010-10-06

Current funding has allowed the restart of testing of various silicone materials placed in Life Tests or Aging Studies from past efforts. Some of these materials have been in test since 1982, with no testing for approximately 10 years, until funding allowed the restart in FY97. Charts for the various materials at different thickness, compression, and temperature combinations illustrate trends for the load-bearing properties of the materials.

Measuring the quality-of-life effects of diagnostic and screening tests.

PubMed

Swan, J Shannon; Miksad, Rebecca A

2009-08-01

Health-related quality of life (HRQL) is a central concept for understanding the outcomes of medical care. When used in cost-effectiveness analysis, HRQL is typically measured for conditions persisting over long time frames (years), and quality-adjusted life year (QALY) values are generated. Consequently, years are the basic unit of time for cost-effectiveness analysis results: dollars spent per QALY gained. However, shorter term components of health care may also affect HRQL, and there is increased interest in measuring and accounting for these events. In radiology, the short-term HRQL effects of screening and diagnostic testing may affect a test's cost-effectiveness, even though they may only last for days. The unique challenge in radiology HRQL assessment is to realistically tap into the testing and screening experience while remaining consistent with QALY theory. The authors review HRQL assessment and highlight methods developed to specifically address the short-term effects of radiologic screening and testing.

Testing and testing positive: childhood adversities and later life HIV status among Kenyan women and their partners.

PubMed

Goodman, Michael L; Raimer-Goodman, Lauren; Chen, Catherine X; Grouls, Astrid; Gitari, Stanley; Keiser, Philip H

2017-12-01

Adverse childhood experiences are a critical feature of lifelong health. No research assesses whether childhood adversities predict HIV-testing behaviors, and little research analyzes childhood adversities and later life HIV status in sub-Saharan Africa. We use regression models with cross-sectional data from a representative sample (n = 1974) to analyze whether adverse childhood experiences, separately or as cumulative exposures, predict reports of later life HIV testing and testing HIV+ among semi-rural Kenyan women and their partners. No significant correlation was observed between thirteen cumulative childhood adversities and reporting prior HIV testing for respondent or partner. Separately, childhood sexual abuse and emotional neglect predicted lower odds of reporting having previously been tested for HIV. Witnessing household violence during one's childhood predicted significantly higher odds of reporting HIV+. Sexual abuse predicted higher odds of reporting a partner tested HIV+. Preventing sexual abuse and household violence may improve HIV testing and test outcomes among Kenyan women. More research is required to understand pathways between adverse childhood experiences and partner selection within Kenya and sub-Saharan Africa, and data presented here suggest understanding pathways may help improve HIV outcomes. © The Author 2016. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Capturing real-life forgetting in transient epileptic amnesia via an incidental memory test.

PubMed

Hoefeijzers, Serge; Zeman, Adam; Della Sala, Sergio; Dewar, Michaela

2017-12-13

Transient epileptic amnesia (TEA) is an epileptic syndrome characterized by recurrent, brief episodes of amnesia. Patients with TEA often complain of interictal (between attacks) retention deficits, characterised by an 'evaporation' of memories for recent events over days to weeks. Clinical tests of anterograde memory often fail to corroborate these complaints as TEA patients commonly perform within the normal range after the standard 10-30-min delay period. Modified laboratory tests that include a 1-3 week delay period frequently reveal clear evidence of 'accelerated long-term forgetting' (ALF). However, they are not used routinely and lack ecological validity. In the present study we examined whether 'real-life' ALF can be captured via a controlled incidental memory test in TEA patients. To this end, the experimenter told 27 TEA patients and 32 controls a well-rehearsed amusing story, apparently as a way of making light conversation before starting a set of research experiments. Without prior warning, the experimenter subsequently probed the participants' memory of this story via tests of free recall and forced choice recognition after 30 min or 1 week. After 30 min retention was comparable in TEA patients and controls. After 1 week TEA patients retained significantly less story material than controls, and significant ALF was revealed in the TEA patients in the recognition test. Our data show that ALF in a 'real-life' situation can occur even when standard memory tests indicate normal memory function. Moreover, our data suggest that incidental memory tests can capture real-life ALF, and that forced-choice recognition tests might be more sensitive than free recall tests for the detection of real-life ALF. Copyright © 2017 Elsevier Ltd. All rights reserved.

Life testing of a nine-couple hybrid thermoelectric panel

NASA Technical Reports Server (NTRS)

Bifano, W. J.

1973-01-01

Life test data are presented for a nine couple thermoelectric panel of hybrid couples tested at an average hot junction temperature of 840 C (1113 K). In the hybrid couple, a hollow cylinder of p-type Si-Ge is used to encapsulate a segmented PbTe/Si-Ge n-leg. The output power and internal resistance of the panel as well as the resistances of the individual hybrid couples are presented as functions of test time covering a period of more than 4200 hours. Test results indicated improved stability relative to hybrid couples tested at higher temperatures. Thermal cycling of the panel resulted in an order of magnitude increase in room temperature resistance. However, very little change in resistance at operating temperatures was noted following the thermal cycles.

GOES Type III Loop Heat Pipe Life Test Results

NASA Technical Reports Server (NTRS)

Ottenstein, Laura

2011-01-01

The GOES Type III Loop Heat Pipe (LHP) was built as a life test unit for the loop heat pipes on the GOES N-Q series satellites. This propylene LHP was built by Dynatherm Corporation in 2000 and tested continuously for approximately 14 months. It was then put into storage for 3 years. Following the storage period, the LHP was tested at Swales Aerospace to verify that the loop performance hadn t changed. Most test results were consistent with earlier results. At the conclusion of testing at Swales, the LHP was transferred to NASA/GSFC for continued periodic testing. The LHP has been set up for testing in the Thermal Lab at GSFC since 2006. A group of tests consisting of start-ups, power cycles, and a heat transport limit test have been performed every six to nine months since March 2006. Tests results have shown no change in the loop performance over the five years of testing. This presentation will discuss the test hardware, test set-up, and tests performed. Test results to be presented include sample plots from individual tests, along with conductance measurements for all tests performed.

Screening for Breast Cancer: #BeBrave: A Life-Saving Test

MedlinePlus

... page please turn JavaScript on. Feature: Screening For Breast Cancer #BeBrave: A Life-Saving Test Past Issues / Summer ... of others facing the disease. You discovered your breast cancer in an unusually public way. Would you tell ...

Selected topics in railroad tank car safety. Volume 2 : test plan for accelerated life testing of thermally shielded tank cars

DOT National Transportation Integrated Search

1978-08-01

A test plan for the accelerated life testing of thermally shielded tank cars is described. The test program would be conducted at the DOT Transportation Test Center in Pueblo, Colorado. Eighteen tank cars would be included in the program. Five cars w...

Environmental control and life support testing at the Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Schunk, Richard G.; Humphries, William R.

1987-01-01

The Space Station Environmental Control and Life Support System (ECLSS) test program at the Marshall Space Flight Center (MSFC) is addressed. The immediate goals and current activities of the test program are discussed. Also described are the Core Module Integration Facility (CMIF) and the initial ECLSS test configuration. Future plans for the ECLSS test program and the CMIF are summarized.

Cycle life test of secondary spacecraft cells

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1980-01-01

The results of the life cycling program on rechargeable calls are reported. Information on required data, the use of which the data will be put, application details, including orbital description, charge control methods, load rquirements, etc., are given. Cycle tests were performed on 660 sealed, nickel cadmium cells. The cells consisted of seven sample classifications ranging form 3.0 to 20 amp. hours. Nickel cadmium, silver cadmium, and silver zinc sealed cells, excluding synchronous orbit and accelerated test packs were added. The capacities of the nickel cadmium cells, the silver cadmium and the silver zinc cells differed in range of amp hrs. The cells were cylced under different load, charge control, and temperature conditions. All cell packs are recharged by use of a pack voltage limit. All charging is constant current until the voltage limit is reached.

Methodology for Life Testing of Refractory Metal/Sodium Heat Pipes

NASA Technical Reports Server (NTRS)

Martin, James J.; Reid, Robert S.

2006-01-01

The focus of this work was to establish an approach to generate carefully controlled data that can conclusively establish heat pipe operating life with material-fluid combinations capable of extended operation. To accomplish this goal acceleration is required to compress 10 years of operational life into 3 years of laboratory testing through a combination of increased temperature and mass fluence. Specific test series have been identi3ed, based on American Society for Testing and Materials (ASTM) specifications, to investigate long term corrosion rates. The refractory metal selected for demonstration purposes is a Molybdenum-44.5%Rhenium alloy formed by powder metallurgy. The heat pipe makes use of an annular crescent wick design formed by hot isostatic pressing of Molybdenum-Rhenium wire mesh. The heat pipes are filled using vacuum distillation and purity sampling is considered. Testing of these units is round-the-clock with 6-month destructive and non-destructive inspection intervals to identify the onset and level of corrosion. Non-contact techniques are employed for providing power to the evaporator (radio frequency induction heating at I to 5 kW per unit) and calorimetry at the condenser (static gas gap coupled water cooled calorimeter). The planned operating temperature range would extend from 1123 to 1323 K. Accomplishments prior to project cancellation included successful demonstration of the heat pipe wick fabrication technique, establishment of all engineering designs, baselined operational test requirements and procurement/assembly of supporting test hardware systems.

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

PubMed

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.

A 10,000-hr life test of an engineering model resistojet

NASA Technical Reports Server (NTRS)

Slutz, Rodger J.

1990-01-01

One of the major issues associated with using resistojet thrusters on Space Station Freedom is the long life required. An engineering model resistojet was life-tested to determine if it was capable of meeting that requirement. This thruster, which was designed for 10,000 hr of operation at 2552.4 F (1400 C) or less under cyclical thermal conditions, successfully operated for 10,036 hr at 1836 F (1002 C) while undergoing 141 thermal cycles.

Definition study for an extended manned test of a regenerative life support system, preliminary test plan

NASA Technical Reports Server (NTRS)

1971-01-01

A preliminary plan and procedure are presented for conducting an extended manned test program for a regenerative life support system. Emphasis will be placed on elements associated with long-term system operation and long-term uninterrupted crew confinement.

Life Cycle Testing of Viscoelastic Material for Hubble Space Telescope Solar Array 3 Damper

NASA Technical Reports Server (NTRS)

Maly, Joseph R.; Reed, Benjamin B.; Viens, Michael J.; Parker, Bradford H.; Pendleton, Scott C.

2003-01-01

During the March 2002 Servicing Mission by Space Shuttle (STS 109), the Hubble Space Telescope (HST) was refurbished with two new solar arrays that now provide all of its power. These arrays were built with viscoelastic/titanium dampers, integral to the supporting masts, which reduce the interaction of the wing bending modes with the Telescope. Damping of over 3% of critical was achieved. To assess the damper s ability to maintain nominal performance over the 10-year on-orbit design goal, material specimens were subjected to an accelerated life test. The test matrix consisted of scheduled events to expose the specimens to pre-determined combinations of temperatures, frequencies, displacement levels, and numbers of cycles. These exposure events were designed to replicate the life environment of the damper from fabrication through testing to launch and life on-orbit. To determine whether material degradation occurred during the exposure sequence, material performance was evaluated before and after the accelerated aging with complex stiffness measurements. Based on comparison of pre- and post-life-cycle measurements, the material is expected to maintain nominal performance through end of life on-orbit. Recent telemetry from the Telescope indicates that the dampers are performing nominally.

Evaluation of tilting disc valves after fatigue life testing: preliminary results within a comparison program.

PubMed

Barbaro, V; Boccanera, G; Daniele, C; Grigioni, M; Palombo, A

1995-09-01

A fatigue life test, by accelerating the beat rate, simulates several years of virtual life of a prosthetic heart valve in a short period of time. The correlation between the in vivo life of a valve and in vitro testing expectations is as yet not well established, but reproducible test conditions yield precious information about wear and failure. The paper reports a qualitative analysis of mechanical valve wear as part of a comparison program designed to investigate the significance of fatigue testing with the ultimate aim of defining standard guidelines for these type of tests. Two tilting disc valves (29 mm) were subjected to 16 years of fatigue life simulated by means of a Rowan Ash fatigue tester (accelerated rate of 1,200 bpm). Fatigue-induced effects on valve disc and ring surfaces were observed under a monitor microscope to identify wear sites and patterns. A high speed cinematographic system was used to investigate the mechanisms responsible for the wear (wear modes). Valve closure was inspected at a 6,000 frame/s rate. Because of disc rotation during the tilting movement, the points of contact between disc and ring are distributed all around the disc edge but focally on the ring. On both sides of the disc, the surfaces present ring-like concentric grooves. After 16 years of fatigue life the valves showed neither severe wear nor alteration of their fluidodynamic behavior in the pulsatile flow test.

NWSC nickel cadmium spacecraft cell accelerated life test program data analysis

NASA Technical Reports Server (NTRS)

Lander, J.

1980-01-01

An analysis of the data leading to a proposed accelerated life test scheme to test a nickel cadmium cell under spacecraft usage conditions is described. The amount and concentration of electrolyte and the amount of precharge in the cell are discussed in relation to the design of the cell and the accelerated test design. A failure analysis of the cell is summarized. The analysis included such environmental test variables as the depth of discharge, the temperature, the amount of recharge and the charge and discharge rate.

The 1.06 micrometer wideband laser modulator: Fabrication and life testing

NASA Technical Reports Server (NTRS)

Teague, J. R.

1975-01-01

The design, fabrication, testing and delivery of an optical modulator which will operate with a mode-locked Nd:YAG laser at 1.06 micrometers were performed. The system transfers data at a nominal rate of 400 Mbps. This wideband laser modulator can transmit either Pulse Gated Binary Modulation (PGBM) or Pulse Polarization Binary Modulation (PPBM) formats. The laser beam enters the modulator and passes through both crystals; approximately 1% of the transmitted beam is split from the main beam and analyzed for the AEC signal; the remaining part of the beam exits the modulator. The delivered modulator when initially aligned and integrated with laser and electronics performed very well. The optical transmission was 69.5%. The static extinction ratio was 69:1. A 1000 hour life test was conducted with the delivered modulator. A 63 bit pseudorandom code signal was used as a driver input. At the conclusion of the life test the modulator optical transmission was 71.5% and the static extinction ratio 65:1.

Aquatic toxicity testing for aquatic life impact assessments and recent scientific advancements

EPA Science Inventory

The focus of this presentation is to provide an overview of the use of aquatic toxicity testing for assessing possible impacts to aquatic life and how new scientific approaches are being researched. Toxicity testing of both ambient and effluent monitoring samples will be discusse...

Composite Service Life Prediction via Fiber Bundle Testing. Evaluation of Testing Equipment and Data Acquisition System

DTIC Science & Technology

1986-12-01

PREDICTION VIA FIBER BUNDLE TESTING-EVALUATION OF TESTING EQUIPMENT JD DATA ACQUISITION SYSTEM PERSONAL AUTHOR(S) Petridis Dimitrios M. i *y?e o j report...experiencing a known number of filament failures per bundle. The results of this investigation are relevant to man-safe applications as in composite pressure...single filament r’iber testing and can become more 29 3> C o - Pwo PwS ?w4 Pw3 Pw2 Pwl PSD Ps5 PS4 Ps3 Ps2 PS! homoiogous correspondence t ~ to Life ( Laqt

Development of Probabilistic Life Prediction Methodologies and Testing Strategies for MEMS and CMC's

NASA Technical Reports Server (NTRS)

Jadaan, Osama

2003-01-01

This effort is to investigate probabilistic life prediction methodologies for ceramic matrix composites and MicroElectroMechanical Systems (MEMS) and to analyze designs that determine stochastic properties of MEMS. For CMC's this includes a brief literature survey regarding lifing methodologies. Also of interest for MEMS is the design of a proper test for the Weibull size effect in thin film (bulge test) specimens. The Weibull size effect is a consequence of a stochastic strength response predicted from the Weibull distribution. Confirming that MEMS strength is controlled by the Weibull distribution will enable the development of a probabilistic design methodology for MEMS - similar to the GRC developed CARES/Life program for bulk ceramics. A main objective of this effort is to further develop and verify the ability of the Ceramics Analysis and Reliability Evaluation of Structures/Life (CARES/Life) code to predict the time-dependent reliability of MEMS structures subjected to multiple transient loads. A second set of objectives is to determine the applicability/suitability of the CARES/Life methodology for CMC analysis, what changes would be needed to the methodology and software, and if feasible, run a demonstration problem. Also important is an evaluation of CARES/Life coupled to the ANSYS Probabilistic Design System (PDS) and the potential of coupling transient reliability analysis to the ANSYS PDS.

Design of Refractory Metal Life Test Heat Pipe and Calorimeter

NASA Technical Reports Server (NTRS)

Martin, J. J.; Reid, R. S.; Bragg-Sitton, S. M.

2010-01-01

Heat pipe life tests have seldom been conducted on a systematic basis. Typically, one or more heat pipes are built and tested for an extended period at a single temperature with simple condenser loading. Results are often reported describing the wall material, working fluid, test temperature, test duration, and occasionally the nature of any failure. Important information such as design details, processing procedures, material assay, power throughput, and radial power density are usually not mentioned. We propose to develop methods to generate carefully controlled data that conclusively establish heat pipe operating life with material-fluid combinations capable of extended operation. The test approach detailed in this Technical Publication will use 16 Mo-44.5%Re alloy/sodium heat pipe units that have an approximate12-in length and 5/8-in diameter. Two specific test series have been identified: (1) Long-term corrosion rates based on ASTM-G-68-80 (G-series) and (2) corrosion trends in a cross-correlation sequence at various temperatures and mass fluences based on a Fisher multifactor design (F-series). Evaluation of the heat pipe hardware will be performed in test chambers purged with an inert purified gas (helium or helium/argon mixture) at low pressure (10-100 torr) to provide thermal coupling between the heat pipe condenser and calorimeter. The final pressure will be selected to minimize the potential for voltage breakdown between the heat pipe and radio frequency (RF) induction coil (RF heating is currently the planned method of powering the heat pipes). The proposed calorimeter is constructed from a copper alloy and relies on a laminar flow water-coolant channel design to absorb and transport energy

30 CFR 27.35 - Tests to determine life of critical components and subassemblies.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Tests to determine life of critical components and subassemblies. 27.35 Section 27.35 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test...

30 CFR 27.35 - Tests to determine life of critical components and subassemblies.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Tests to determine life of critical components and subassemblies. 27.35 Section 27.35 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS METHANE-MONITORING SYSTEMS Test...

Active matrix organic light emitting diode (AMOLED) performance and life test results

NASA Astrophysics Data System (ADS)

Fellowes, David A.; Wood, Michael V.; Hastings, Arthur R., Jr.; Draper, Russell S.; Lum, Alden K.; Ghosh, Amalkumar P.; Prache, Olivier; Wacyk, Ihor

2010-04-01

The US Army and eMagin Corporation established a Cooperative Research and Development Agreement (CRADA) to characterize the ongoing improvements in the lifetime of OLED displays. This CRADA also called for the evaluation of OLED performance as the need arises, especially when new products are developed or when a previously untested parameter needs to be understood. In 2006, eMagin Corporation developed long-life OLED-XLTM devices for use in their AMOLED microdisplays for head-worn applications. Through Research and Development programs from 2007 to 2009 with the US Government, eMagin made additional improvements in OLED life and developed the first SXGA (1280 × 1024 triad pixels) OLED microdisplay. US Army RDECOM CERDEC NVESD conducted life and performance tests on these displays, publishing results at the 2007, 2008, and 2009 SPIE Defense and Security Symposia1,2,3. Life and performance tests have continued through 2009, and this data will be presented along with a recap of previous data. This should result in a better understanding of the applicability of AMOLEDs in military and commercial head mounted systems: where good fits are made, and where further development might be desirable.

Active matrix organic light-emitting diode (AMOLED) performance and life test results

NASA Astrophysics Data System (ADS)

Fellowes, David A.; Wood, Michael V.; Hastings, Arthur R., Jr.; Draper, Russell S.; Ghosh, Amalkumar; Prache, Olivier; Wacyk, Ihor; Ali, Tariq; Khayrullin, Ilyas

2011-06-01

The US Army and eMagin Corporation established a Cooperative Research and Development Agreement (CRADA) to characterize the ongoing improvements in the lifetime of OLED displays. This CRADA also called for the evaluation of OLED performance as the need arises, especially when new products are developed or when a previously untested parameter needs to be understood. In 2006, eMagin Corporation developed long-life OLED-XL devices for use in their AMOLED microdisplays for head-worn applications. Through research and development programs from 2007 to 2010 with the US Government, eMagin made additional improvements in OLED life and developed the first SXGA (1280 X 1024 triad pixels) OLED microdisplay. US Army RDECOM CERDEC NVESD conducted life and performance tests on these displays, publishing results at the 2007, 2008, 2009, and 2010 SPIE Defense and Security Symposia1,2,3,4. Life and performance tests have continued through 2010, and this data will be presented along with a recap of previous data. This should result in a better understanding of the applicability of AMOLEDs in military and commercial head mounted systems: where good fits are made, and where further development might be desirable.

Update of the NEXT Ion Thruster Service Life Assessment with Post-Test Correlation to the Long Duration Test

NASA Technical Reports Server (NTRS)

Yim, John T.; Soulas, George C.; Shastry, Rohit; Choi, Maria; Mackey, Jonathan A.; Sarver-Verhey, Timothy R.

2017-01-01

The service life assessment for NASA's Evolutionary Xenon Thruster is updated to incorporate the results from the successful and voluntarily early completion of the 51,184 hour long duration test which demonstrated 918 kg of total xenon throughput. The results of the numerous post-test investigations including destructive interrogations have been assessed against all of the critical known and suspected failure mechanisms to update the life and throughput expectations for each major component. Analysis results of two of the most acute failure mechanisms, namely pit-and-groove erosion and aperture enlargement of the accelerator grid, are not updated in this work but will be published at a future time after analysis completion.

Consequences of early extraction of compromised first permanent molar: a systematic review.

PubMed

Saber, Afnan M; Altoukhi, Doua H; Horaib, Mariam F; El-Housseiny, Azza A; Alamoudi, Najlaa M; Sabbagh, Heba J

2018-04-05

The aim of this study was to systematically review the literature to determine the sequelae of early extraction of compromised first permanent molars (FPMs) with regard to the skeletal and dental development of 5- to 15-year-old children. Meta-analysis was conducted when applicable. Our research protocol included a search strategy, inclusion/exclusion criteria, and a data extraction plan. The search engines used were PubMed, Scopus, and Science Direct. Study selection was performed independently by three reviewers. Articles published from 1960 to 2017 were reviewed based on inclusion and exclusion criteria. Meta-analysis was performed to compare space closure between upper and lower arches. Eleven studies fulfilled the inclusion criteria. The consequences were decrease in post extraction space, accelerated development and eruption of second permanents molars (SPMs) and third molars, a decrease in caries and/or fillings on the proximal surfaces of adjacent teeth, lingual tipping and retrusion of incisors, and counter clockwise rotation of the occlusal plane. There were several consequences of early extraction of FPMs, which were related to skeletal and dental development. Our systematic review suggests that comprehensive evaluation of the compromised FPMs should be performed before planning an extraction. The ideal time for FPM extraction is when the SPM is at the early bifurcation stage in order to achieve complete closure of the extraction space by the SPM. Benefits should be weighed over the risks to decrease the risk of unfavorable outcomes as much as possible. However, due to the limited evidence on the outcomes and variables that influence them, high-quality prospective studies are needed.

Johnson Space Center's regenerative life support systems test bed

NASA Technical Reports Server (NTRS)

Henninger, Donald L.; Tri, Terry O.; Barta, Daniel J.; Stahl, Randal S.

1991-01-01

The Regenerative Life Support System (RLSS) Test Bed at NASA's Johnson Space Center is an atmospherically closed, controlled environment facility for the evaluation of regenerative life support systems using higher plants in conjunction with physicochemical life support systems. When completed, the facility will be comprised of two large scale plant growth chambers, each with approximately 10 m(exp 2) growing area. One of the two chambers, the Variable Pressure Growth Chamber (VPGC), will be capable of operating at lower atmospheric pressures to evaluate a range of environments that may be used in Lunar or Martian habitats; the other chamber, the Ambient Pressure Growth Chamber (APGC) will operate at ambient atmospheric pressure. The root zone in each chamber will be configurable for hydroponic or solid state media systems. Research will focus on: (1) in situ resource utilization for CELSS systems, in which simulated lunar soils will be used in selected crop growth studies; (2) integration of biological and physicochemical air and water revitalization systems; (3) effect of atmospheric pressure on system performance; and (4) monitoring and control strategies.

Fracture mechanics life analytical methods verification testing

NASA Technical Reports Server (NTRS)

Favenesi, J. A.; Clemons, T. G.; Riddell, W. T.; Ingraffea, A. R.; Wawrzynek, P. A.

1994-01-01

The objective was to evaluate NASCRAC (trademark) version 2.0, a second generation fracture analysis code, for verification and validity. NASCRAC was evaluated using a combination of comparisons to the literature, closed-form solutions, numerical analyses, and tests. Several limitations and minor errors were detected. Additionally, a number of major flaws were discovered. These major flaws were generally due to application of a specific method or theory, not due to programming logic. Results are presented for the following program capabilities: K versus a, J versus a, crack opening area, life calculation due to fatigue crack growth, tolerable crack size, proof test logic, tearing instability, creep crack growth, crack transitioning, crack retardation due to overloads, and elastic-plastic stress redistribution. It is concluded that the code is an acceptable fracture tool for K solutions of simplified geometries, for a limited number of J and crack opening area solutions, and for fatigue crack propagation with the Paris equation and constant amplitude loads when the Paris equation is applicable.

NSTAR Extended Life Test Discharge Chamber Flake Analysis

NASA Technical Reports Server (NTRS)

deGroh, Kim K.; Banks, Bruce A.; Karniotis, Christina A.

2005-01-01

The Extended Life Test (ELT) of the NASA Solar Electric Propulsion Technology Readiness (NSTAR) ion thruster was concluded after 30,352 hours of operation. The ELT was conducted using the Deep Space 1 (DS1) back-up flight engine, a 30 cm diameter xenon ion thruster. Post-test inspection of the ELT engine revealed numerous contaminant flakes distributed over the bottom of the cylindrical section of the anode within the discharge chamber (DC). Extensive analyses were conducted to determine the source of the particles, which is critical to the understanding of degradation mechanisms of long life ion thruster operation. Analyses included: optical microscopy (OM) and particle length histograms, field emission scanning electron microscopy (FESEM) combined with energy dispersive spectroscopy (EDS), and atomic oxygen plasma exposure tests. Analyses of the particles indicate that the majority of the DC flakes consist of a layered structure, typically with either two or three layers. The flakes comprising two layers were typically found to have a molybdenum-rich (Mo-rich) layer on one side and a carbon-rich (C-rich) layer on the other side. The flakes comprising three layers were found to be sandwich-like structures with Mo-rich exterior layers and a C-rich interior layer. The presence of the C-rich layers indicates that these particles were produced by sputter deposition build-up on a surface external to the discharge chamber from ion sputter erosion of the graphite target in the test chamber. This contaminant layer became thick enough that particles spalled off, and then were electro-statically attracted into the ion thruster interior, where they were coated with Mo from internal sputter erosion of the screen grid and cathode components. Atomic oxygen tests provided evidence that the DC chamber flakes are composed of a significant fraction of carbon. Particle size histograms further indicated that the source of the particles was spalling of carbon flakes from downstream

Multi-Criteria Decision Analysis of Test Endpoints for Detecting the Effects of Endocrine Active Substances in Fish Full Life Cycle Tests

EPA Science Inventory

Fish full life cycle (FFLC) tests are increasingly required in the ecotoxicological assessment of endocrine active substances. However, FFLC tests have not been internationally standardized or validated, and it is currently unclear how such tests should best be designed to provid...

Preliminary psychometric testing of the Fox Simple Quality-of-Life Scale.

PubMed

Fox, Sherry

2004-06-01

Although quality of life is extensively defined as subjective and multidimensional with both affective and cognitive components, few instruments capture important dimensions of the construct, and few are both conceptually congruent and user friendly for the clinical setting. The aim of this study was to develop and test a measure that would be easy to use clinically and capture both cognitive and affective components of quality of life. Initial item sources for the Fox Simple Quality-of-Life Scale (FSQOLS) were literature-based. Thirty items were compiled for content validity assessment by a panel of expert healthcare clinicians from various disciplines, predominantly nursing. Five items were removed as a result of the review because they reflected negatively worded or redundant items. The 25-item scale was mailed to 177 people with lung, colon, and ovarian cancer in various stages. Cancer types were selected theoretically, based on similarity in prognosis, degree of symptom burden, and possible meaning and experience. Of the 145 participants, all provided complete data on the FSQOLS. Psychometric evaluation of the FSQOLS included item-total correlations, principal components analysis with varimax rotation revealing two factors explaining 50% variance, reliability estimation using alpha estimates, and item-factor correlations. The FSQOLS exhibited significant convergent validity with four popular quality-of-life instruments: the Ferrans and Powers Quality of Life Index, the Functional Assessment of Cancer Therapy Scale, the Short-Form-36 Health Survey, and the General Well-Being Scale. Content validity of the scale was explored and supported using qualitative interviews of 14 participants with lung, colon and ovarian cancer, who were a subgroup of the sample for the initial instrument testing.

Measurement Techniques and Instruments Suitable for Life-prediction Testing of Photovoltaic Arrays

NASA Technical Reports Server (NTRS)

Noel, G. T.; Wood, V. E.; Mcginniss, V. D.; Hassell, J. A.; Richard, N. A.; Gaines, G. B.; Carmichael, D. C.

1979-01-01

The validation of a 20-year service life for low-cost photovoltaic arrays is a critical requirement in the Low-Cost Solar Array (LSA) Project. The validation is accomplished through accelerated life-prediction tests. A two-phase study was conducted to address the needs before such tests are carried out. The results and recommended techniques from the Phase 1 investigation are summarized in the appendix. Phase 2 of the study is covered in this report and consisted of experimental evaluations of three techniques selected from these recommended as a results of the Phase 1 findings. The three techniques evaluated were specular and nonspecular optical reflectometry, chemiluminescence measurements, and electric current noise measurements.

Estimation of failure criteria in multivariate sensory shelf life testing using survival analysis.

PubMed

Giménez, Ana; Gagliardi, Andrés; Ares, Gastón

2017-09-01

For most food products, shelf life is determined by changes in their sensory characteristics. A predetermined increase or decrease in the intensity of a sensory characteristic has frequently been used to signal that a product has reached the end of its shelf life. Considering all attributes change simultaneously, the concept of multivariate shelf life allows a single measurement of deterioration that takes into account all these sensory changes at a certain storage time. The aim of the present work was to apply survival analysis to estimate failure criteria in multivariate sensory shelf life testing using two case studies, hamburger buns and orange juice, by modelling the relationship between consumers' rejection of the product and the deterioration index estimated using PCA. In both studies, a panel of 13 trained assessors evaluated the samples using descriptive analysis whereas a panel of 100 consumers answered a "yes" or "no" question regarding intention to buy or consume the product. PC1 explained the great majority of the variance, indicating all sensory characteristics evolved similarly with storage time. Thus, PC1 could be regarded as index of sensory deterioration and a single failure criterion could be estimated through survival analysis for 25 and 50% consumers' rejection. The proposed approach based on multivariate shelf life testing may increase the accuracy of shelf life estimations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transverse Tension Fatigue Life Characterization Through Flexure Testing of Composite Materials

NASA Technical Reports Server (NTRS)

OBrien, T. Kevin; Chawan, Arun D.; Krueger, Ronald; Paris, Isabelle

2001-01-01

The transverse tension fatigue life of S2/8552 glass-epoxy and IM7/8552 carbon-epoxy was characterized using flexure tests of 90-degree laminates loaded in 3-point and 4-point bending. The influence of specimen polishing and specimen configuration on transverse tension fatigue life was examined using the glass-epoxy laminates. Results showed that 90-degree bend specimens with polished machined edges and polished tension-side surfaces, where bending failures where observed, had lower fatigue lives than unpolished specimens when cyclically loaded at equal stress levels. The influence of specimen thickness and the utility of a Weibull scaling law was examined using the carbon-epoxy laminates. The influence of test frequency on fatigue results was also documented for the 4-point bending configuration. A Weibull scaling law was used to predict the 4-point bending fatigue lives from the 3-point bending curve fit and vice-versa. Scaling was performed based on maximum cyclic stress level as well as fatigue life. The scaling laws based on stress level shifted the curve fit S-N characterizations in the desired direction, however, the magnitude of the shift was not adequate to accurately predict the fatigue lives. Furthermore, the scaling law based on fatigue life shifted the curve fit S-N characterizations in the opposite direction from measured values. Therefore, these scaling laws were not adequate for obtaining accurate predictions of the transverse tension fatigue lives.

Space station environmental control and life support systems test bed program - an overview

NASA Astrophysics Data System (ADS)

Behrend, Albert F.

As the National Aeronautics and Space Administration (NASA) begins to intensify activities for development of the Space Station, decisions must be made concerning the technical state of the art that will be baselined for the initial Space Station system. These decisions are important because significant potential exists for enhancing system performance and for reducing life-cycle costs. However, intelligent decisions cannot be made without an adequate assessment of new and ready technologies, i.e., technologies which are sufficiently mature to allow predevelopment demonstrations to prove their application feasibility and to quantify the risk associated with their development. Therefore, the NASA has implemented a technology development program which includes the establishment of generic test bed capabilities in which these new technologies and approaches can be tested at the prototype level. One major Space Station subsystem discipline in which this program has been implemented is the environmental control and life support system (ECLSS). Previous manned space programs such as Gemini, Apollo, and Space Shuttle have relied heavily on consumables to provide environmental control and life support services. However, with the advent of a long-duration Space Station, consumables must be reduced within technological limits to minimize Space Station resupply penalties and operational costs. The use of advanced environmental control and life support approaches involving regenerative processes offers the best solution for significant consumables reduction while also providing system evolutionary growth capability. Consequently, the demonstration of these "new technologies" as viable options for inclusion in the baseline that will be available to support a Space Station initial operational capability in the early 1990's becomes of paramount importance. The mechanism by which the maturity of these new regenerative life support technologies will be demonstrated is the Space

Active matrix organic light emitting diode (AMOLED) performance and life test results

NASA Astrophysics Data System (ADS)

Fellowes, David A.; Botkin, Michael E.; Draper, Russell S.; Coletta, Jason

2013-05-01

The U.S. Army and eMagin Corporation established a Cooperative Research and Development Agreement (CRADA) to characterize the ongoing improvements in the lifetime of OLED displays. This CRADA also called for the evaluation of OLED performance as the need arises, especially when new products are developed or when a previously untested parameter needs to be understood. In 2006, eMagin Corporation developed long-life OLED-XL devices for use in their AMOLED microdisplays for head-worn applications. Through Research and Development programs from 2007 to 2012 with the U.S. Government, eMagin made additional improvements in OLED life and developed the first SXGA (1280 X 1024 with triad pixels) and WUXGA (1920 X 1200 with triad pixels) OLED microdisplays. US Army RDECOM CERDEC NVESD conducted life and performance tests on these displays, publishing results at the 2012, 2011, 2010, 2009, 2008, and 2007 SPIE Defense, Security and Sensing Symposia. Life and performance tests have continued through 2013, and this data will be presented along with a comparison to previous data. This should result in a better understanding of the applicability of AMOLEDs in military and commercial head mounted systems, where good fits are made, and where further development might be desirable.

Active matrix organic light emitting diode (AMOLED) performance and life test results

NASA Astrophysics Data System (ADS)

Fellowes, David A.; Wood, Michael V.; Hastings, Arthur R., Jr.; Draper, Russell S.; Ghosh, Amalkumar; Prache, Olivier; Wacyk, Ihor

2012-06-01

The US Army and eMagin Corporation established a Cooperative Research and Development Agreement (CRADA) to characterize the ongoing improvements in the lifetime of OLED displays. This CRADA also called for the evaluation of OLED performance as the need arises, especially when new products are developed or when a previously untested parameter needs to be understood. In 2006, eMagin Corporation developed long-life OLED-XL devices for use in their AMOLED microdisplays for head-worn applications. Through Research and Development programs from 2007 to 2011 with the US Government, eMagin made additional improvements in OLED life and developed the first SXGA (1280 X 1024 triad pixels) and WUXGA (1920 X 1200) OLED microdisplays. US Army RDECOM CERDEC NVESD conducted life and performance tests on these displays, publishing results at the 2011, 2010, 2009, 2008, and 2007 SPIE Defense, Security and Sensing Symposia1,2,3,4,5. Life and performance tests have continued through 2012, and this data will be presented along with a recap of previous data. This should result in a better understanding of the applicability of AMOLEDs in military and commercial head mounted systems by determining where good fits are made and where further development might be desirable.

The Application of Stress-Relaxation Test to Life Assessment of T911/T22 Weld Metal

NASA Astrophysics Data System (ADS)

Cao, Tieshan; Zhao, Jie; Cheng, Congqian; Li, Huifang

2016-03-01

A dissimilar weld metal was obtained through submerged arc welding of a T911 steel to a T22 steel, and its creep property was explored by stress-relaxation test assisted by some conventional creep tests. The creep rate information of the stress-relaxation test was compared to the minimum and the average creep rates of the conventional creep test. Log-log graph showed that the creep rate of the stress-relaxation test was in a linear relationship with the minimum creep rate of the conventional creep test. Thus, the creep rate of stress-relaxation test could be used in the Monkman-Grant relation to calculate the rupture life. The creep rate of the stress-relaxation test was similar to the average creep rate, and thereby the rupture life could be evaluated by a method of "time to rupture strain." The results also showed that rupture life which was assessed by the Monkman-Grant relation was more accurate than that obtained through the method of "time to rupture strain."

Accelerated vacuum testing of long life ball bearings and sliprings

NASA Technical Reports Server (NTRS)

Meeks, C. R.; Christy, R. I.; Cunningham, A. C.

1971-01-01

Extensive analytical studies and testing have been conducted on bearings and sliprings in vacuum at temperatures from 30 to 130 F. Thirty-six bearings lubricated with two types of oil were tested in vacuum of less than 10 to the minus 8th power torr at speeds from 55 to 180 rpm. Temperatures, load, speed, and oil viscosity were varied to evaluate the effects on life and wear. All bearings performed successfully during a 7-month test, and the potential merits of the two oils were compared. Over 25 different, dry-lubricated brush/slipring material combinations have been tested, with variations of brush and ring design and surface speed. Test results indicate the probability of 10 years or more of slipring and brush lifetime with properly designed brushes for 1-in.-diameter ring rotating at 60 rpm.

Fatigue, Creep-Fatigue, and Thermomechanical Fatigue Life Testing of Alloys

NASA Technical Reports Server (NTRS)

Halford, Gary R.; Lerch, Bradley A.; McGaw, Michael A.

2000-01-01

The fatigue crack initiation resistance of an alloy is determined by conducting a series of tests over a range of values of stress amplitude or strain range. The observed number of cycles to failure is plotted against the stress amplitude or strain range to obtain a fatigue curve. The fatigue properties quoted for an alloy are typically the constants used in the equation(s) that describe the fatigue curve. Fatigue lives of interest may be as low as 10(exp 2) or higher than 10(exp 9) cycles. Because of the enormous scatter associated with fatigue, dozens of tests may be needed to confidently establish a fatigue curve, and the cost may run into several thousands of dollars. To further establish the effects on fatigue life of the test temperature, environment, alloy condition, mean stress effects, creep-fatigue effects, thermomechanical cycling, etc. requires an extraordinarily large and usually very costly test matrix. The total effort required to establish the fatigue resistance of an alloy should not be taken lightly. Fatigue crack initiation tests are conducted on relatively small and presumed to be initially crack-free, samples of an alloy that are intended to be representative of the alloy's metallurgical and physical condition. Generally, samples are smooth and have uniformly polished surfaces within the test section. Some may have intentionally machined notches of well-controlled geometry, but the surface at the root of the notch is usually not polished. The purpose of polishing is to attain a reproducible surface finish. This is to eliminate surface finish as an uncontrolled variable. Representative test specimen geometries will be discussed later. Test specimens are cyclically loaded until macroscopically observable cracks initiate and eventually grow to failure. Normally, the fatigue failure life of a specimen is defined as the number of cycles to separation of the specimen into two pieces. Alternative definitions are becoming more common, particularly for

How are genetic test results being used by Australian life insurers?

PubMed

Barlow-Stewart, K; Liepins, M; Doble, A; Otlowski, M

2018-06-11

In Australia, the USA and many Asian countries the life insurance industry is self-regulated. Individuals must disclose genetic test results known to them in applications for new or updated policies including cover for critical care, income protection and death. There is limited information regarding how underwriting decisions are made for policies with such disclosures. The Australian Financial Services Council (FSC) provided de-identified data collected on applications with genetic test result disclosure from its life insurance member companies 2010-2013 to enable repetition of an independent examination undertaken of applications 1999-2003: age; gender; genetic condition; testing result; decision-maker; and insurance cover. Data was classified as to test result alone or additional other factors relevant to risk and decision. Where necessary, the FSC facilitated clarification by insurers. 345/548 applications related to adult-onset conditions. The genetic test result solely influenced the decision in 165/345 applications: positive (n = 23), negative (n = 139) and pending (n = 3). Detailed analyses of the decisions in each of these result categories are presented with specific details of 11 test cases. Policies with standard decisions were provided for all negative test results with evidence of reassessment of previous non-standard decisions and 20/23 positive results with recognition of risk reduction strategies. Disclosure of positive results for breast/ovarian cancer, Lynch syndrome and hereditary spastic paraplegia, and three pending results, generated non-standard decisions. The examination demonstrates some progress in addressing concerns in regard to utilisation of genetic test information but the self-regulatory system in Australia only goes some way in meeting internationally recommended best practice.

Program operational summary: Operational 90 day manned test of a regenerative life support system

NASA Technical Reports Server (NTRS)

Jackson, J. K.; Wamsley, J. R.; Bonura, M. S.; Seeman, J. S.

1972-01-01

An operational 90-day manned test of a regenerative life support system was successfully completed. This test was performed with a crew of four carefully selected and trained men in a space station simulator (SSS) which had a two gas atmosphere maintained at a total pressure of 68.9, 10 psia, and composed of oxygen at a partial pressure of 3.05 psia with nitrogen as the diluent. The test was planned to provide data on regenerative life support subsystems and on integrated system operations in a closed ecology, similar to that of a space station. All crew equipment and expendables were stored onboard at the start of the mission to eliminate the need for pass-in operations. The significant accomplishments of the test, some of the pertinent test results, some of the problem areas, and conclusions are presented.

Integration and validation testing for PhEDEx, DBS and DAS with the PhEDEx LifeCycle agent

NASA Astrophysics Data System (ADS)

Boeser, C.; Chwalek, T.; Giffels, M.; Kuznetsov, V.; Wildish, T.

2014-06-01

The ever-increasing amount of data handled by the CMS dataflow and workflow management tools poses new challenges for cross-validation among different systems within CMS experiment at LHC. To approach this problem we developed an integration test suite based on the LifeCycle agent, a tool originally conceived for stress-testing new releases of PhEDEx, the CMS data-placement tool. The LifeCycle agent provides a framework for customising the test workflow in arbitrary ways, and can scale to levels of activity well beyond those seen in normal running. This means we can run realistic performance tests at scales not likely to be seen by the experiment for some years, or with custom topologies to examine particular situations that may cause concern some time in the future. The LifeCycle agent has recently been enhanced to become a general purpose integration and validation testing tool for major CMS services. It allows cross-system integration tests of all three components to be performed in controlled environments, without interfering with production services. In this paper we discuss the design and implementation of the LifeCycle agent. We describe how it is used for small-scale debugging and validation tests, and how we extend that to large-scale tests of whole groups of sub-systems. We show how the LifeCycle agent can emulate the action of operators, physicists, or software agents external to the system under test, and how it can be scaled to large and complex systems.

The development and test of a long-life, high reliability solar array drive actuator

NASA Technical Reports Server (NTRS)

Kirkpatrick, D. L.

1973-01-01

To meet the life and reliability requirements of five to ten year space missions, a new solar array drive mechanism for 3-axis stabilized vehicles has been developed and is undergoing life testing. The drive employs a redundant lubrication system to increase its reliability. An overrunning clutch mechanism is used to permit block redundant application of two or more drives to a common array drive shaft. Two prototype actuator and clutch assemblies, in continuous vacuum life test under load at 10 to the minus 8th power torr for more than sixteen months, have each accumulated more than 34,000 output revolutions without anomaly, the equivalent of more than seven years of operation in a 1000 km orbit or nearly ninety-five years at synchronous altitude.

International Space Station Bacteria Filter Element Post-Flight Testing and Service Life Prediction

NASA Technical Reports Server (NTRS)

Perry, J. L.; von Jouanne, R. G.; Turner, E. H.

2003-01-01

The International Space Station uses high efficiency particulate air (HEPA) filters to remove particulate matter from the cabin atmosphere. Known as Bacteria Filter Elements (BFEs), there are 13 elements deployed on board the ISS's U.S. Segment. The pre-flight service life prediction of 1 year for the BFEs is based upon performance engineering analysis of data collected during developmental testing that used a synthetic dust challenge. While this challenge is considered reasonable and conservative from a design perspective, an understanding of the actual filter loading is required to best manage the critical ISS Program resources. Thus testing was conducted on BFEs returned from the ISS to refine the service life prediction. Results from this testing and implications to ISS resource management are discussed. Recommendations for realizing significant savings to the ISS Program are presented.

Electronic Quality of Life Assessment Using Computer-Adaptive Testing

PubMed Central

2016-01-01

Background Quality of life (QoL) questionnaires are desirable for clinical practice but can be time-consuming to administer and interpret, making their widespread adoption difficult. Objective Our aim was to assess the performance of the World Health Organization Quality of Life (WHOQOL)-100 questionnaire as four item banks to facilitate adaptive testing using simulated computer adaptive tests (CATs) for physical, psychological, social, and environmental QoL. Methods We used data from the UK WHOQOL-100 questionnaire (N=320) to calibrate item banks using item response theory, which included psychometric assessments of differential item functioning, local dependency, unidimensionality, and reliability. We simulated CATs to assess the number of items administered before prespecified levels of reliability was met. Results The item banks (40 items) all displayed good model fit (P>.01) and were unidimensional (fewer than 5% of t tests significant), reliable (Person Separation Index>.70), and free from differential item functioning (no significant analysis of variance interaction) or local dependency (residual correlations < +.20). When matched for reliability, the item banks were between 45% and 75% shorter than paper-based WHOQOL measures. Across the four domains, a high standard of reliability (alpha>.90) could be gained with a median of 9 items. Conclusions Using CAT, simulated assessments were as reliable as paper-based forms of the WHOQOL with a fraction of the number of items. These properties suggest that these item banks are suitable for computerized adaptive assessment. These item banks have the potential for international development using existing alternative language versions of the WHOQOL items. PMID:27694100

PREDICTING CHRONIC LETHALITY OF CHEMICALS TO FISHES FROM ACUTE TOXICITY TEST DATA: THEORY OF ACCELERATED LIFE TESTING

EPA Science Inventory

A method for modeling aquatic toxicity date based on the theory of accelerated life testing and a procedure for maximum likelihood fitting the proposed model is presented. he procedure is computerized as software, which can predict chronic lethality of chemicals using data from a...

Alkali metal pool boiler life tests for a 25 kWe advanced Stirling conversion system

NASA Technical Reports Server (NTRS)

Anderson, W. G.; Rosenfeld, J. H.; Noble, J.

1991-01-01

The overall operating temperature and efficiency of solar-powered Stirling engines can be improved by adding an alkali metal pool boiler heat transport system to supply heat more uniformly to the heater head tubes. One issue with liquid metal pool boilers is unstable boiling. Stable boiling is obtained with an enhanced boiling surface containing nucleation sites that promote continuous boiling. Over longer time periods, it is possible that the boiling behavior of the system will change. An 800-h life test was conducted to verify that pool boiling with the chosen fluid/surface combination remains stable as the system ages. The apparatus uses NaK boiling on a - 100 + 140 stainless steel sintered porous layer, with the addition of a small amount of xenon. Pool boiling remained stable to the end of life test. The pool boiler life test included a total of 82 cold starts, to simulate startup each morning, and 60 warm restarts, to simulate cloud cover transients. The behavior of the cold and warm starts showed no significant changes during the life test. In the experiments, the fluid/surface combination provided stable, high-performance boiling at the operating temperature of 700 C. Based on these experiments, a pool boiler was designed for a full-scale 25-kWe Stirling system.

Methodology for designing accelerated aging tests for predicting life of photovoltaic arrays

NASA Technical Reports Server (NTRS)

Gaines, G. B.; Thomas, R. E.; Derringer, G. C.; Kistler, C. W.; Bigg, D. M.; Carmichael, D. C.

1977-01-01

A methodology for designing aging tests in which life prediction was paramount was developed. The methodology builds upon experience with regard to aging behavior in those material classes which are expected to be utilized as encapsulant elements, viz., glasses and polymers, and upon experience with the design of aging tests. The experiences were reviewed, and results are discussed in detail.

Life insurance and genetic test results: a mutation carrier's fight to achieve full cover.

PubMed

Keogh, Louise A; Otlowski, Margaret F A

2013-09-02

Currently, there is debate about life insurance companies' use of genetic information for assessing applicants. In his early 20s, James (pseudonym) was denied full life insurance cover because he revealed that he had discussed genetic testing with a genetic counsellor. He was later tested and found to carry a mutation in the MSH6 gene; after disclosing this, he was denied cover for cancer by two other life insurance companies. Unsatisfied with the insurance companies' risk assessments, and based on his understanding that regular colonoscopy significantly reduced his risk of cancer, James made a complaint to the Australian Human Rights Commission. After informing the third insurance company that he had done so, he was offered full coverage, which suggests that the company did not have actuarial data to justify its decision. This case provides evidence of the high level of initiative and proactivity required for a consumer to achieve a fair result. Few Australians would be in a position to pursue the level of research and advocacy undertaken by James (a professional with scientific training). We call on a collaborative approach between industry, government and researchers to address the issues that James's case raises about genetic testing and life insurance.

Early Human Testing Initiative Phase 1 Regenerative Life Support Systems

NASA Image and Video Library

1995-08-08

Early Human Testing (EHT) Initiative Phase 1 Regenerative Life Support Systems Laboratory (RLSSL). Nigel Packham activities in the Variable Pressure Growth Chamber which he lived inside for 15 days. A crowd of well-wishers outside the test chamber, at the console are John Lewis, Ed Mohr and Marybeth Edeen (15577). Packham exiting the chamber (15578-81). Packham is the focus of television cameras and reporters (15582-3). Don Henninger interviewed by reporters (15584). Packham is presented with a jacket after his stay in the chamber (15585). Packham inside the wheat growth chamber checking the condition of the plants (15586-7, 15597). Packham exercising on a recumbant bicycle (15588, 15592). Packham, through the window into the growth chamber, displays a handful of wheat plants to console monitor Dan Barta (15589-90). Group portrait of the team conducting the Early Human Testing Initiative Phase 1 Regenerative Life Support Systems test and include, front row, from left: Jeff Dominick and Don Overton and back row, from left, unidentified member, Marybeth Edeen, Nigel Packham, John Lewis, Ed Mohr, Dan Barta and Tim Monk (15591). Harry Halford prepares to send a package through the airlock to Packham (15593). Packham displays a handful of wheat plants (15594). Packham fixes himself a bowl of cereal (15595) and retrieves a carton of milk from the refrigerator (15596). Packham retrieves a package from the airlock (15598). Packham packs up trash in plastic bag (15599-600) and sends it back through the airlock (15601). Packham gets a cup of water (15602) and heats it in the microwave (15603).

Application of supercontinuum radiation for mid-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Kilgus, Jakob; Müller, Petra; Moselund, Peter M.; Brandstetter, Markus

2016-04-01

The emergence of new laser-based mid-infrared (MIR) sources, such as quantum cascade lasers (QCL), led to substantial developments in the field of MIR spectroscopy in the last decade. Recently, also MIR supercontinuum (SC) sources became available. They combine broadband spectral emission known from thermal sources emission with coherent properties known from laser sources like QCLs. Nevertheless, while the latter already find practical application in the field of optical sensing, SC sources have yet to prove their applicability. In this contribution we present the development, characterization and application of a measurement concept consisting of a fiber-coupled broadband MIR SC source (1.75 μm-4.2 μm, 75 mW optical power) and a fully-integrated MOEMS-based Fabry-Pérot microspectrometer (FPMS) for MIR spectroscopy. The main hindrance for the use of SC sources in spectroscopy so far, are the significant pulse-to-pulse fluctuations arising from the non-linear nature of the SC generation process. We show to what extent spectral averaging makes sense and evaluate the noise performance. By combining a SC source and a FPMS it was possible to significantly reduce noise in spectral, time and polarization domain, resulting in a set-up suitable for MIR spectroscopy. The performance of the set-up was characterized both in transmission and reflection geometry. Low-noise absorption spectra of oils, polymers and aqueous solutions of acetic acid were acquired . Furthermore, time-resolved measurements of the curing process of ethyl-2-cyanoacrylate and results of the chemical mapping of a painted metal surface are reported. The obtained results prove the concept of SC-FPMS promising for MIR spectroscopy, characterized by its simplicity and versatility.

Benchmark Calibration Tests Completed for Stirling Convertor Heater Head Life Assessment

NASA Technical Reports Server (NTRS)

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

2005-01-01

A major phase of benchmark testing has been completed at the NASA Glenn Research Center (http://www.nasa.gov/glenn/), where a critical component of the Stirling Radioisotope Generator (SRG) is undergoing extensive experimentation to aid the development of an analytical life-prediction methodology. Two special-purpose test rigs subjected SRG heater-head pressure-vessel test articles to accelerated creep conditions, using the standard design temperatures to stay within the wall material s operating creep-response regime, but increasing wall stresses up to 7 times over the design point. This resulted in well-controlled "ballooning" of the heater-head hot end. The test plan was developed to provide critical input to analytical parameters in a reasonable period of time.

Environmental Control and Life Support Systems Test Facility at MSFC

NASA Technical Reports Server (NTRS)

2001-01-01

The Marshall Space Flight Center (MSFC) is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. Scientists and engineers at the MSFC are working together to provide the ISS with systems that are safe, efficient, and cost-effective. These compact and powerful systems are collectively called the Environmental Control and Life Support Systems, or simply, ECLSS. This photograph shows the development Water Processor located in two racks in the ECLSS test area at the Marshall Space Flight Center. Actual waste water, simulating Space Station waste, is generated and processed through the hardware to evaluate the performance of technologies in the flight Water Processor design.

Psychometric Evaluation of the Life Orientation Test-Revised in Treated Opiate Dependent Individuals

ERIC Educational Resources Information Center

Hirsch, Jameson K.; Britton, Peter C.; Conner, Kenneth R.

2010-01-01

We examined internal consistency and test-retest reliability of a measure of dispositional optimism, the Life Orientation Test-Revised, in 121 opiate-dependent patients seeking methadone treatment. Internal consistency was adequate at baseline (alpha = 0.69) and follow-up (alpha = 0.72). Low socioeconomic status and being on disability were…

Strain-Life Assessment of Grainex Mar-M 247 for NASA's Turbine Seal Test Facility

NASA Technical Reports Server (NTRS)

Delgado, Irebert R.; Halford, Gary R.; Steinetz, Bruce M.; Rimnac, Clare M.

2004-01-01

NASA s Turbine Seal Test Facility is used to test air-to-air seals for use primarily in advanced jet engine applications. Combinations of high temperature, high speed, and high pressure limit the disk life, due to the concern of crack initiation in the bolt holes of the Grainex Mar-M 247 disk. The primary purpose of this current work is to determine an inspection interval to ensure safe operation. The current work presents high temperature fatigue strain-life data for test specimens cut from an actual Grainex Mar-M 247 disk. Several different strain-life models were compared to the experimental data including the Manson-Hirschberg Method of Universal Slopes, the Halford-Nachtigall Mean Stress Method, and the Modified Morrow Method. The Halford-Nachtigall Method resulted in only an 18 percent difference between predicted and experimental results. Using the experimental data at a 99.95 percent prediction level and the presence of 6 bolt holes it was found that the disk should be inspected after 665 cycles based on a total strain of 0.5 percent at 649 C.

Neural Network Models of Simple Mechanical Systems Illustrating the Feasibility of Accelerated Life Testing

NASA Technical Reports Server (NTRS)

Fusaro, Robert L.; Jones, Steven P.; Jansen, Ralph

1996-01-01

A complete evaluation of the tribological characteristics of a given material/mechanical system is a time-consuming operation since the friction and wear process is extremely systems sensitive. As a result, experimental designs (i.e., Latin Square, Taguchi) have been implemented in an attempt to not only reduce the total number of experimental combinations needed to fully characterize a material/mechanical system, but also to acquire life data for a system without having to perform an actual life test. Unfortunately, these experimental designs still require a great deal of experimental testing and the output does not always produce meaningful information. In order to further reduce the amount of experimental testing required, this study employs a computer neural network model to investigate different material/mechanical systems. The work focuses on the modeling of the wear behavior, while showing the feasibility of using neural networks to predict life data. The model is capable of defining which input variables will influence the tribological behavior of the particular material/mechanical system being studied based on the specifications of the overall system.

Environmental Control and Life Support Systems Testing Facility at MSFC

NASA Technical Reports Server (NTRS)

2001-01-01

The Marshall Space Flight Center (MSFC) is responsible for designing and building the life support systems that will provide the crew of the International Space Station (ISS) a comfortable environment in which to live and work. Scientists and engineers at the MSFC are working together to provide the ISS with systems that are safe, efficient, and cost-effective. These compact and powerful systems are collectively called the Environmental Control and Life Support Systems, or simply, ECLSS. This photograph shows the Urine Processor Assembly (UPA) which utilizes the Vapor Compression Distillation (VCD) technology. The VCD is used for integrated testing of the entire Water Recovery System (WRS) and development testing of the Urine Processor Assembly. The UPA accepts and processes pretreated crewmember urine to allow it to be processed along with other wastewaters in the Water Processor Assembly (WPA). The WPA removes free gas, organic, and nonorganic constituents before the water goes through a series of multifiltration beds for further purification. Product water quality is monitored primarily through conductivity measurements. Unacceptable water is sent back through the WPA for reprocessing. Clean water is sent to a storage tank.

A Multigene Test Could Cost-Effectively Help Extend Life Expectancy for Women at Risk of Hereditary Breast Cancer.

PubMed

Li, Yonghong; Arellano, Andre R; Bare, Lance A; Bender, Richard A; Strom, Charles M; Devlin, James J

2017-04-01

The National Comprehensive Cancer Network recommends that women who carry gene variants that confer substantial risk for breast cancer consider risk-reduction strategies, that is, enhanced surveillance (breast magnetic resonance imaging and mammography) or prophylactic surgery. Pathogenic variants can be detected in women with a family history of breast or ovarian cancer syndromes by multigene panel testing. To investigate whether using a seven-gene test to identify women who should consider risk-reduction strategies could cost-effectively increase life expectancy. We estimated effectiveness and lifetime costs from a payer perspective for two strategies in two hypothetical cohorts of women (40-year-old and 50-year-old cohorts) who meet the National Comprehensive Cancer Network-defined family history criteria for multigene testing. The two strategies were the usual test strategy for variants in BRCA1 and BRCA2 and the seven-gene test strategy for variants in BRCA1, BRCA2, TP53, PTEN, CDH1, STK11, and PALB2. Women found to have a pathogenic variant were assumed to undergo either prophylactic surgery or enhanced surveillance. The incremental cost-effectiveness ratio for the seven-gene test strategy compared with the BRCA1/2 test strategy was $42,067 per life-year gained or $69,920 per quality-adjusted life-year gained for the 50-year-old cohort and $23,734 per life-year gained or $48,328 per quality-adjusted life-year gained for the 40-year-old cohort. In probabilistic sensitivity analysis, the seven-gene test strategy cost less than $100,000 per life-year gained in 95.7% of the trials for the 50-year-old cohort. Testing seven breast cancer-associated genes, followed by risk-reduction management, could cost-effectively improve life expectancy for women at risk of hereditary breast cancer. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Testing and Oxygen Assessment Results for a Next Generation Extravehicular Activity Portable Life Support System Fan

NASA Technical Reports Server (NTRS)

Paul, Heather L.; Jennings, Mallory A.; Rivera, Fatonia L.; Martin, Devin

2011-01-01

NASA is designing a next generation Extravehicular Activity (EVA) Portable Life Support System (PLSS) for use in future surface exploration endeavors. To meet the new requirements for ventilation flow at nominal and buddy modes, a fan has been developed and tested. This paper summarizes the results of the performance and life cycle testing efforts conducted at the NASA Johnson Space Center. Additionally, oxygen compatibility assessment results from an evaluation conducted at White Sands Test Facility (WSTF) are provided, and lessons learned and future recommendations are outlined.

Test-retest reliability of the trauma and life events self-report inventory.

PubMed

Hovens, J E; Bramsen, I; van der Ploeg, H M; Reuling, I E

2000-12-01

Three groups of first-year male and female medical students (total N = 90) completed the Trauma and Life Events Self-report Inventory twice. Test-retest reliability for the three different time periods was .82, .89, and .75, respectively.

Lunar-Mars Life Support Test Project. Phase 2; Human Factors and Crew Interactions

NASA Technical Reports Server (NTRS)

Ming, D. W.; Hurlbert, K. M.; Kirby, G.; Lewis, J. F.; ORear, P.

1997-01-01

Phase 2 of the Lunar-Mars Life Support Test Project was conducted in June and July of 1996 at the NASA Johnson Space Center. The primary objective of Phase 2 was to demonstrate and evaluate an integrated physicochemical air revitalization and regenerative water recovery system capable of sustaining a human crew of four for 30 days inside a closed chamber. The crew (3 males and 1 female) was continuously present inside a chamber throughout the 30-day test. The objective of this paper was to describe crew interactions and human factors for the test. Crew preparations for the test included training and familiarization of chamber systems and accommodations, and medical and psychological evaluations. During the test, crew members provided metabolic loads for the life support systems, performed maintenance on chamber systems, and evaluated human factors inside the chamber. Overall, the four crew members found the chamber to be comfortable for the 30-day test. The crew performed well together and this was attributed in part to team dynamics, skill mix (one commander, two system experts, and one logistics lead), and a complementary mix of personalities. Communication with and support by family, friends, and colleagues were identified as important contributors to the high morale of the crew during the test. Lessons learned and recommendations for future testing are presented by the crew in this paper.

Novel Electrochemical Test Bench for Evaluating the Functional Fatigue Life of Biomedical Alloys

NASA Astrophysics Data System (ADS)

Ijaz, M. F.; Dubinskiy, S.; Zhukova, Y.; Korobkova, A.; Pustov, Y.; Brailovski, V.; Prokoshkin, S.

2017-08-01

The aim of the present work was first to develop and validate a test bench that simulates the in vitro conditions to which the biomedical implants will be actually subjected in vivo. For the preliminary application assessments, the strain-controlled fatigue tests of biomedically pure Ti and Ti-Nb-Zr alloy in simulated body fluid were undertaken. The in situ open-circuit potential measurements from the test bench demonstrated a strong dependence on the dynamic cycling and kind of material under testing. The results showed that during fatigue cycling, the passive oxide film formed on the surface of Ti-Nb-Zr alloy was more resistant to fatigue degradation when compared with pure Ti. The Ti-Nb-Zr alloy exhibited prolonged fatigue life when compared with pure Ti. The fractographic features of both materials were also characterized using scanning electron microscopy. The electrochemical results and the fractographic evidence confirmed that the prolonged functional fatigue life of the Ti-Nb-Zr alloy is apparently ascribable to the reversible martensitic phase transformation.

Accelerated life testing and reliability of high K multilayer ceramic capacitors

NASA Technical Reports Server (NTRS)

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.

Application of the Life Safety Code to a Historic Test Stand

NASA Technical Reports Server (NTRS)

Askins, Bruce; Lemke, Paul R.; Lewis, William L.; Covell, Carol C.

2011-01-01

NASA has conducted a study to assess alternatives to refurbishing existing launch vehicle modal test facilities as opposed to developing new test facilities to meet the demands of a very fiscally constrained test and evaluation environment. The results of this study showed that Marshall Space Flight Center (MSFC) Test Stand (TS) 4550 could be made compliant, within reasonable cost and schedule impacts, if safety processes and operational limitations were put in place to meet the safety codes and concerns of the Fire Marshall. Trades were performed with key selection criteria to ensure that appropriate levels of occupant safety are incorporated into test facility design modifications. In preparation for the ground vibration tests that were to be performed on the Ares I launch vehicle, the Ares Flight and Integrated Test Office (FITO) organization evaluated the available test facility options, which included the existing mothballed structural dynamic TS4550 used by Apollo and Shuttle, alternative ground vibration test facilities at other locations, and construction of a new dynamic test stand. After an exhaustive assessment of the alternatives, the results favored modifying the TS4550 because it was the lowest cost option and presented the least schedule risk to the NASA Constellation Program for Ares Integrated Vehicle Ground Vibration Test (IVGVT). As the renovation design plans and drawings were being developed for TS4550, a safety concern was discovered the original design for the construction of the test stand, originally built for the Apollo Program and renovated for the Shuttle Program, was completed before NASA s adoption of the currently imposed safety and building codes per National Fire Protection Association Life Safety Code [NFPA 101] and International Building Codes. The initial FITO assessment of the design changes, required to make TS4550 compliant with current safety and building standards, identified a significant cost increase and schedule impact

Crack propagation analysis and fatigue life prediction for structural alloy steel based on metal magnetic memory testing

NASA Astrophysics Data System (ADS)

Ni, Chen; Hua, Lin; Wang, Xiaokai

2018-09-01

To monitor the crack propagation and predict the fatigue life of ferromagnetic material, the metal magnetic memory (MMM) testing was carried out to the single edge notched specimen made from structural alloy steel under three-point bending fatigue experiment in this paper. The variation of magnetic memory signal Hp (y) in process of fatigue crack propagation was investigated. The gradient K of Hp (y) was investigated and compared with the stress of specimen obtained by finite element analysis. It indicated that the gradient K can qualitatively reflect the distribution and variation of stress. The maximum gradient Kmax and crack size showed a good linear relationship, which indicated that the crack propagation can be estimated by MMM testing. Furthermore, the damage model represented by magnetic memory characteristic was created and a fatigue life prediction method was developed. The fatigue life can be evaluated by the relationship between damage parameter and normalized life. The method was also verified by another specimen. Because of MMM testing, it provided a new approach for predicting fatigue life.

Life testing of metal-ceramic CO2 lasers

NASA Technical Reports Server (NTRS)

Fahlen, T. S.; Radecki, D. J.; Reynolds, R. S.; Targ, R.

1971-01-01

The main purpose of this program was to determine the life characteristics of nine space-qualified, metal-ceramic CO2 lasers. Lifetimes ranged between about 400 hours to over 2000 hours (the limit of testing) with a high degree of consistency in like groups. In all cases the tubes which had failed could be restored to near their original power by doubling the cathode current for 30 minutes. Periodic rejuvenation allowed operation for the full 2000 hours on all tubes. The failure mechanism appears to involve formation of NiO and C on the nickel cathode emission surface with subsequent absorption of tube gases.

Low Temperature Life-Cycle Testing of a Lithium-Ion Battery for Low-Earth-Orbiting Spacecraft

NASA Technical Reports Server (NTRS)

Reid, Concha

2006-01-01

A flight-qualified, lithium-ion (Li-ion) battery developed for the Mars Surveyor Program 2001 Landeris undergoing life-testing at low temperature under a low-Earth-orbit (LEO) profile to assess its capability to provide long term energy storage for aerospace missions. NASA has embarked upon an ambitious course to return humans to the moon by 2015-2020 in preparation for robotic and human exploration of Mars and robotic exploration of the moons of outer planets. Li-ion batteries are excellent candidates to provide power and energy storage for multiple aspects of these missions due to their high specific energy, high energy density, and excellent low temperature performance. Laboratory testing of Li-ion technology is necessary in order to assess lifetime, characterize multi-cell battery-level performance under aerospace conditions, and to gauge safety aspects of the technology. Life-cycle testing provides an opportunity to examine battery-level performance and the dynamics of individual cells in the stack over the entire life of the battery. Data generated through this testing will be critical to establish confidence in the technology for its widespread use in manned and unmanned missions.

Life Testing and Diagnostics of a Planar Out-of-Core Thermionic Converter

NASA Astrophysics Data System (ADS)

Thayer, Kevin L.; Ramalingam, Mysore L.; Young, Timothy J.; Lamp, Thomas R.

1994-07-01

This paper details the design and performance of an automated computer data acquisition system for a planar, out-of-core thermionic converter with CVD rhenium electrodes. The output characteristics of this converter have been mapped for emitter temperatures ranging from approximately 1700K to 2000K, and life testing of the converter is presently being performed at the design point of operation. An automated data acquisition system has been constructed to facilitate the collection of current density versus output voltage (J-V) and temperature data from the converter throughout the life test. This system minimizes the amount of human interaction necessary during the lifetest to measure and archive the data and present it in a usable form. The task was accomplished using a Macintosh Ilcx computer, two multiple-purpose interface boards, a digital oscilloscope, a sweep generator, and National Instrument's LabVIEW application software package.

Low Temperature Life-cycle Testing of a Lithium-ion Battery for Low-earth-orbiting Spacecraft

NASA Technical Reports Server (NTRS)

Reid, Concha

2004-01-01

A flight-qualified, lithium-ion (Li-ion) battery developed for the Mars Surveyor Program 2001 lander is undergoing life-testing at low temperature under a low-Earth-orbit (LEO) profile to assess its capability to provide long term energy storage for aerospace missions. NASA has embarked upon an ambitious course to return humans to the moon by 2015-2020 in preparation for robotic and human exploration of Mars and robotic exploration of the moons of outer planets. Li-ion batteries are excellent candidates to provide power and energy storage for multiple aspects of these missions due to their low specific energy, low energy density, and excellent low temperature performance. Laboratory testing of Li-ion technology is necessary in order to assess lifetime, characterize multi-cell battery-level performance under aerospace conditions, and to gauge safety aspects of the technology. Life-cycle testing provides an opportunity to examine battery-level performance and the dynamics of individual cells in the stack over the entire life of the battery. Data generated through this testing will be critical to establish confidence in the technology for its widespread use in manned and unmanned mission. This paper discusses the performance of the 28 volt, 25 ampere-hour battery through 6000 LEO cycles, which corresponds to one year on LEO orbit. Testing is being performed at 0 C and 40% depth-of-discharge. Individual cell behaviors and their effect on the performance of the battery are described. Capacity, impedance, energy efficiency and end-of-discharge voltage at 1000 cycle intervals are reported. Results from this life-testing will help contribute to the database on battery-level performance of aerospace Li-ion batteries and low temperature cycling under LEO conditions.

Destructive Evaluation of a Xenon Hollow Cathode after a 28,000 Hour Life Test

NASA Technical Reports Server (NTRS)

Sarver-Verhey, Timothy R.

1998-01-01

International Space Station (ISS) plasma contactor system requires a hollow cathode assembly (HCA) with a lifetime of at least 18,000 hours. In order to demonstrate the lifetime capability of the HCA, a series of hollow cathode wear tests was performed which included a life test operated at the maximum current of the HCA. This test sought to verify hollow cathode lifetime capability and contamination control protocols. This hollow cathode accumulated 27,800 hours of operation before it failed during a restart attempt. The cathode was subsequently destructively analyzed in order to determine the failure mechanism. Microscopic examination of the cathode interior determined that relatively small changes in the cathode physical geometry had occurred and barium tungstates, which are known to limit the emission process, had formed over a majority of the electron emitter surface. Because the final state of the insert was consistent with expected impregnate chemistry, the hollow cathode was believed to have reached the end of its usable life under the test conditions.

Life prediction of l6 steel using strain-life curve and cyclic stress-strain curve by means of low cycle fatigue testing

NASA Astrophysics Data System (ADS)

Inamdar, Sanket; Ukhande, Manoj; Date, Prashant; Lomate, Dattaprasad; Takale, Shyam; Singh, RKP

2017-05-01

L6 Steel is used as die material in closed die hot forging process. This material is having some unique properties. These properties are due to its composition. Strain softening is the noticeable property of this material. Due to this in spite of cracking at high stress this material gets plastically deformed and encounters loss in time as well as money. Studies of these properties are necessary to nurture this material at fullest extent. In this paper, numerous experiments have been carried on L6 material to evaluate cyclic Stress - strain behavior as swell as strain-life behavior of the material. Low cycle fatigue test is carried out on MTS fatigue test machine at fully reverse loading condition R=-1. Also strain softening effect on forging metal forming process is explained in detail. The failed samples during low cycle fatigue test further investigated metallurgically on scanning electron microscopy. Based on this study, life estimation of hot forging die is carried out and it’s correlation with actual shop floor data is found out. This work also concludes about effect of pre-treatments like nitro-carburizing and surface coating on L6 steel material, to enhance its fatigue life to certain extent.

Grainex Mar-M 247 Turbine Disk Life Study for NASA's High Temperature High Speed Turbine Seal Test Facility

NASA Technical Reports Server (NTRS)

Delgado, Irebert R.

2015-01-01

An experimental and analytical fatigue life study was performed on the Grainex Mar-M 247 disk used in NASA s Turbine Seal Test Facility. To preclude fatigue cracks from growing to critical size in the NASA disk bolt holes due to cyclic loading at severe test conditions, a retirement-for-cause methodology was adopted to detect and monitor cracks within the bolt holes using eddy-current inspection. For the NASA disk material that was tested, the fatigue strain-life to crack initiation at a total strain of 0.5 percent, a minimum to maximum strain ratio of 0, and a bolt hole temperature of 649 C was calculated to be 665 cycles using -99.95 percent prediction intervals. The fatigue crack propagation life was calculated to be 367 cycles after implementing a safety factor of 2 on life. Thus, the NASA disk bolt hole total life or retirement life was determined to be 1032 cycles at a crack depth of 0.501 mm. An initial NASA disk bolt hole inspection at 665 cycles is suggested with 50 cycle inspection intervals thereafter to monitor fatigue crack growth.

Active matrix organic light emitting diode (AMOLED)-XL performance and life test results

NASA Astrophysics Data System (ADS)

Fellowes, David A.; Wood, Michael V.; Hastings, Arthur R., Jr.; Draper, Russell S.; Lum, Alden K.; Ghosh, Amalkumar P.; Prache, Olivier; Wacyk, Ihor

2009-05-01

The US Army and eMagin Corporation established a Cooperative Research and Development Agreement (CRADA) to characterize the ongoing improvements in the lifetime of OLED displays. This CRADA also called for the evaluation of OLED performance as the need arises, especially when new products are developed or when a previously untested parameter needs to be understood. In 2006, eMagin Corporation developed long-life OLED-XL devices for use in their AMOLED microdisplays for head-worn applications. RDECOM CERDEC NVESD conducted life tests on these displays, finding over 200% lifetime improvement for the OLED-XL devices over the standard OLED displays, publishing results at the 2007 and 2008 SPIE Defense and Security Symposia1,2. In 2008, eMagin Corporation made additional improvements on the lifetime of their displays and developed the first SXGA (1280 × 1024 triad pixels) OLED microdisplay. A summary of the life and performance tests run at CERDEC NVESD will be presented along with a recap of previous data. This should result in a better understanding of the applicability of AMOLEDs in military and commercial head mounted systems: where good fits are made, and where further development might be desirable.

An extended life and performance test of a low-power arcjet

NASA Technical Reports Server (NTRS)

Curran, Francis M.; Haag, Thomas W.

1988-01-01

An automated, cyclic life test was performed to demonstrate the reliability and endurance of a low power dc cycle arcjet thruster. Over 1000 hr and 500 on-off cycles were accumulated which would represent the requirements for about 15 years of on-orbit lifetime. A hydrogen/nitrogen propellant mixture was used to simulate decomposed hydrazine propellant and the power level was nominally 1.2 kW after the burn-in period. The arcjet operated in a very repeatable fashion from cycle to cycle. The steady state voltage increased by approximately 6 V over the first 300 hr, and then by only 3 V through the remainder of the test. Thrust measurements taken before, during, and after the test verified that the thruster performed in a consistent fashion throughout the tests at a specific impulse of 450 to 460 sec. Post-test component evaluation revealed limited erosion on both the anode and cathode. Other thruster components, including graphite seals, appeared undamaged.

Accelerated life testing and temperature dependence of device characteristics in GaAs CHFET devices

NASA Technical Reports Server (NTRS)

Gallegos, M.; Leon, R.; Vu, D. T.; Okuno, J.; Johnson, A. S.

2002-01-01

Accelerated life testing of GaAs complementary heterojunction field effect transistors (CHFET) was carried out. Temperature dependence of single and synchronous rectifier CHFET device characteristics were also obtained.

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

NASA Technical Reports Server (NTRS)

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.

Life Test Results for Water Heat Pipes Operating at 200 °C to 300 °C

NASA Astrophysics Data System (ADS)

Rosenfeld, John H.; Gernert, Nelson J.

2008-01-01

For lunar or planetary bases to be viable, a robust electric generating system will be required for powering the habitat. Water heat pipes offer an attractive solution for lunar base heat rejection, and would serve as a qualification for them on other long duration missions. Successful operation near the upper end of water operating range is a requirement for the application. Results are reported for life tests on water heat pipes that were operated at various temperatures between 200 °C and 300 °C. Tests were conducted on twenty three gravity-assisted water heat pipes. Eleven titanium/water heat pipes and ten Monel/water heat pipes were tested at temperatures above 200 °C. Two cupronickel heat pipes were also assembled and tested. Titanium alloys tested included CP-2 titanium, as well as two beta-titanium alloys, namely 15-3 and Nitinol alloys. Some of the titanium alloy life tests used wicks fabricated from CP-2 titanium screen or porous felt. Monel alloys tested included 400 and K-500 alloys. Some of the Monel heat pipes contained copper/nickel wicks that were fabricated by brazing nickel-plated copper felt metal wicks. Although most of the envelope/material combinations exhibit favorable results at 200 °C, some of the combinations failed at higher temperatures. Causes of failure included stress-creep of envelopes and corrosion at axial or end cap welds. This information represents a significant advance in selection of materials for 200 °C to 300 °C water heat pipes. Life testing work is being continued.

Analysis of Phenix end-of-life natural convection test with the MARS-LMR code

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

Jeong, H. Y.; Ha, K. S.; Lee, K. L.

The end-of-life test of Phenix reactor performed by the CEA provided an opportunity to have reliable and valuable test data for the validation and verification of a SFR system analysis code. KAERI joined this international program for the analysis of Phenix end-of-life natural circulation test coordinated by the IAEA from 2008. The main objectives of this study were to evaluate the capability of existing SFR system analysis code MARS-LMR and to identify any limitation of the code. The analysis was performed in three stages: pre-test analysis, blind posttest analysis, and final post-test analysis. In the pre-test analysis, the design conditionsmore » provided by the CEA were used to obtain a prediction of the test. The blind post-test analysis was based on the test conditions measured during the tests but the test results were not provided from the CEA. The final post-test analysis was performed to predict the test results as accurate as possible by improving the previous modeling of the test. Based on the pre-test analysis and blind test analysis, the modeling for heat structures in the hot pool and cold pool, steel structures in the core, heat loss from roof and vessel, and the flow path at core outlet were reinforced in the final analysis. The results of the final post-test analysis could be characterized into three different phases. In the early phase, the MARS-LMR simulated the heat-up process correctly due to the enhanced heat structure modeling. In the mid phase before the opening of SG casing, the code reproduced the decrease of core outlet temperature successfully. Finally, in the later phase the increase of heat removal by the opening of the SG opening was well predicted with the MARS-LMR code. (authors)« less

Color discrimination across four life decades assessed by the Cambridge Colour Test.

PubMed

Paramei, Galina V

2012-02-01

Color discrimination was estimated using the Cambridge Colour Test (CCT) in 160 normal trichromats of four life decades, 20-59 years of age. For each age cohort, medians and tolerance limits of the CCT parameters are tabulated. Compared across the age cohorts (Kruskal-Wallis test), the Trivector test showed increases in the three vectors, Protan, Deutan, and Tritan, with advancing age; the Ellipses test revealed significant elongation of the major axes of all three ellipses but no changes in either the axis ratio or the angle of the ellipse major axis. Multiple comparisons (Mann-Whitney test) between the cohorts of four age decades (20+,…,50+) revealed initial benign deterioration of color discrimination in the 40+ decade, as an incremental loss of discrimination along the Deutan axis (Trivector test), and in the 50+ decade, as an elongation of the major axes of all three ellipses (Ellipses test). © 2012 Optical Society of America

Mysid (Mysidopsis bahia) life-cycle test: Design comparisons and assessment

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

Lussier, S.M.; Champlin, D.; Kuhn, A.

1996-12-31

This study examines ASTM Standard E1191-90, ``Standard Guide for Conducting Life-cycle Toxicity Tests with Saltwater Mysids,`` 1990, using Mysidopsis bahia, by comparing several test designs to assess growth, reproduction, and survival. The primary objective was to determine the most labor efficient and statistically powerful test design for the measurement of statistically detectable effects on biologically sensitive endpoints. Five different test designs were evaluated varying compartment size, number of organisms per compartment and sex ratio. Results showed that while paired organisms in the ASTM design had the highest rate of reproduction among designs tested, no individual design had greater statistical powermore » to detect differences in reproductive effects. Reproduction was not statistically different between organisms paired in the ASTM design and those with randomized sex ratios using larger test compartments. These treatments had numerically higher reproductive success and lower within tank replicate variance than treatments using smaller compartments where organisms were randomized, or had a specific sex ratio. In this study, survival and growth were not statistically different among designs tested. Within tank replicate variability can be reduced by using many exposure compartments with pairs, or few compartments with many organisms in each. While this improves variance within replicate chambers, it does not strengthen the power of detection among treatments in the test. An increase in the number of true replicates (exposure chambers) to eight will have the effect of reducing the percent detectable difference by a factor of two.« less

Comparison of real-life accidental falls in older people with experimental falls in middle-aged test subjects.

PubMed

Kangas, M; Vikman, I; Nyberg, L; Korpelainen, R; Lindblom, J; Jämsä, T

2012-03-01

Falling is a common accident among older people. Automatic fall detectors are one method of improving security. However, in most cases, fall detectors are designed and tested with data from experimental falls in younger people. This study is one of the first to provide fall-related acceleration data obtained from real-life falls. Wireless sensors were used to collect acceleration data during a six-month test period in older people. Data from five events representing forward falls, a sideways fall, a backwards fall, and a fall out of bed were collected and compared with experimental falls performed by middle-aged test subjects. The signals from real-life falls had similar features to those from intentional falls. Real-life forward, sideways and backward falls all showed a pre impact phase and an impact phase that were in keeping with the model that was based on experimental falls. In addition, the fall out of bed had a similar acceleration profile as the experimental falls of the same type. However, there were differences in the parameters that were used for the detection of the fall phases. The beginning of the fall was detected in all of the real-life falls starting from a standing posture, whereas the high pre impact velocity was not. In some real-life falls, multiple impacts suggested protective actions. In conclusion, this study demonstrated similarities between real-life falls of older people and experimental falls of middle-aged subjects. However, some fall characteristics detected from experimental falls were not detectable in acceleration signals from corresponding heterogeneous real-life falls. Copyright © 2011 Elsevier B.V. All rights reserved.

Child exposure to serious life events, COMT, and aggression: Testing differential susceptibility theory.

PubMed

Hygen, Beate Wold; Belsky, Jay; Stenseng, Frode; Lydersen, Stian; Guzey, Ismail Cuneyt; Wichstrøm, Lars

2015-08-01

Both genetic and environmental factors contribute to individual differences in aggression. Catechol-O-methyltransferase Val158Met (COMT), a common, functional polymorphism, has been implicated in aggression and aggression traits, as have childhood experiences of adversity. It is unknown whether these effects are additive or interactional and, in the case of interaction, whether they conform to a diathesis-stress or differential susceptibility model. We examined Gene × Environment interactions between COMT and serious life events on measures of childhood aggression and contrasted these 2 models. The sample was composed of community children (N = 704); 355 were boys, and the mean age was 54.8 months (SD = 3.0). The children were genotyped for COMT rs4680 and assessed for serious life events and by teacher-rated aggression. Regression analysis showed no main effects of COMT and serious life events on aggression. However, a significant interactive effect of childhood serious life events and COMT genotype was observed: Children who had faced many serious life events and were Val homozygotes exhibited more aggression (p = .02) than did their Met-carrying counterparts. Notably, in the absence of serious life events, Val homozygotes displayed significantly lower aggression scores than did Met carriers (p = .03). When tested, this constellation of findings conformed to the differential susceptibility hypothesis: In this case, Val homozygotes are more malleable to the effect of serious life events on aggression and not simply more vulnerable to the negative effect of having experienced many serious life events. (c) 2015 APA, all rights reserved).

Performance Characterization of a Microchannel Liquid/Liquid Heat Exchanger Throughout an Extended Duration Life Test

NASA Technical Reports Server (NTRS)

Sheth, Rubik B.; Stephan, Ryan A.; Hawkins-Reynolds Ebony

2011-01-01

Liquid/Liquid Heat Exchangers (L/L HX) are an integral portion of any spacecraft active thermal control system. For this study the X-38 L/L HX was used as a baseline. As detailed in a previous ICES manuscript, NASA paired with Pacific Northwest National Laboratory to develop a Microchannel L/L HX (MHX). This microchannel HX was designed to meet the same performance characteristics as the aforementioned X-38 HX. The as designed Microchannel HX has a 26% and 60% reduction in mass and volume, respectively. Due to the inherently smaller flow passages the design team was concerned about fouling affecting performance during extended missions. To address this concern, NASA has developed a test stand and is currently performing an 18 month life test on the MHX. This report will detail the up-to-date performance of the MHX during life testing.

Life shocks and crime: a test of the "turning point" hypothesis.

PubMed

Corman, Hope; Noonan, Kelly; Reichman, Nancy E; Schwartz-Soicher, Ofira

2011-08-01

Other researchers have posited that important events in men's lives-such as employment, marriage, and parenthood-strengthen their social ties and lead them to refrain from crime. A challenge in empirically testing this hypothesis has been the issue of self-selection into life transitions. This study contributes to this literature by estimating the effects of an exogenous life shock on crime. We use data from the Fragile Families and Child Wellbeing Study, augmented with information from hospital medical records, to estimate the effects of the birth of a child with a severe health problem on the likelihood that the infant's father engages in illegal activities. We conduct a number of auxiliary analyses to examine exogeneity assumptions. We find that having an infant born with a severe health condition increases the likelihood that the father is convicted of a crime in the three-year period following the birth of the child, and at least part of the effect appears to operate through work and changes in parental relationships. These results provide evidence that life events can cause crime and, as such, support the "turning point" hypothesis.

Hydroponics Database and Handbook for the Advanced Life Support Test Bed

NASA Technical Reports Server (NTRS)

Nash, Allen J.

1999-01-01

During the summer 1998, I did student assistance to Dr. Daniel J. Barta, chief plant growth expert at Johnson Space Center - NASA. We established the preliminary stages of a hydroponic crop growth database for the Advanced Life Support Systems Integration Test Bed, otherwise referred to as BIO-Plex (Biological Planetary Life Support Systems Test Complex). The database summarizes information from published technical papers by plant growth experts, and it includes bibliographical, environmental and harvest information based on plant growth under varying environmental conditions. I collected 84 lettuce entries, 14 soybean, 49 sweet potato, 16 wheat, 237 white potato, and 26 mix crop entries. The list will grow with the publication of new research. This database will be integrated with a search and systems analysis computer program that will cross-reference multiple parameters to determine optimum edible yield under varying parameters. Also, we have made preliminary effort to put together a crop handbook for BIO-Plex plant growth management. It will be a collection of information obtained from experts who provided recommendations on a particular crop's growing conditions. It includes bibliographic, environmental, nutrient solution, potential yield, harvest nutritional, and propagation procedure information. This handbook will stand as the baseline growth conditions for the first set of experiments in the BIO-Plex facility.

Initial development and psychometric testing of an instrument to measure the quality of children's end-of-life care.

PubMed

Widger, Kimberley; Tourangeau, Ann E; Steele, Rose; Streiner, David L

2015-01-01

The field of pediatric palliative care is hindered by the lack of a well-defined, reliable, and valid method for measuring the quality of end-of-life care. The study purpose was to develop and test an instrument to measure mothers' perspectives on the quality of care received before, at the time of, and following a child's death. In Phase 1, key components of quality end-of-life care for children were synthesized through a comprehensive review of research literature. These key components were validated in Phase 2 and then extended through focus groups with bereaved parents. In Phase 3, items were developed to assess structures, processes, and outcomes of quality end-of-life care then tested for content and face validity with health professionals. Cognitive testing was conducted through interviews with bereaved parents. In Phase 4, bereaved mothers were recruited through 10 children's hospitals/hospices in Canada to complete the instrument, and psychometric testing was conducted. Following review of 67 manuscripts and 3 focus groups with 10 parents, 141 items were initially developed. The overall content validity index for these items was 0.84 as rated by 7 health professionals. Based on feedback from health professionals and cognitive testing with 6 parents, a 144-item instrument was finalized for further testing. In Phase 4, 128 mothers completed the instrument, 31 of whom completed it twice. Test-retest reliability, internal consistency, and construct validity were demonstrated for six subscales: Connect With Families, Involve Parents, Share Information With Parents, Share Information Among Health Professionals, Support Parents, and Provide Care at Death. Additional items with content validity were grouped in four domains: Support the Child, Support Siblings, Provide Bereavement Follow-up, and Structures of Care. Forty-eight items were deleted through psychometric testing, leaving a 95-item instrument. There is good initial evidence for the reliability and

Accelerated and real-time geosynchronous life cycling test performance of nickel-hydrogen batteries

NASA Technical Reports Server (NTRS)

Green, R. S.

1985-01-01

RCA Astro-Electronics currently has four nickel-hydrogen storage battery modules (11 cells each) on test in simulated geosynchronous life cycle regimes. These battery modules are of identical design to those used on the GSTAR (GTE Satellite Corp.) and Spacenet (GTE Spacenet Corp.) communications satellites. The batteries are being tested using an automated test station equipped with computer-controlled environmental chambers and recording equipment. The two battery types, 30 ampere-hours and 40 ampere-hours (GSTAR and Spacenet, respectively), are being electrically cycled using identical 44-day eclipse sequences at 5 C and vary with respect to depth of discharge, recharge ratio, duration of accumulated suntime, and the use of a reconditioning sequence. The test parameters are outlined and the preliminary test data and results are presented.

Continuing life test of a xenon hollow cathode for a space plasma contactor

NASA Technical Reports Server (NTRS)

Sarver-Verhey, Timothy R.

1994-01-01

Implementation of a hollow cathode plasma contactor for charge control on the Space Station has required validation of long-life hollow cathodes. A test series of hollow cathodes and hollow cathode plasma contactors was initiated as part of the plasma contactor development program. An on-going wear-test of a hollow cathode has demonstrated cathode operation in excess of 10,000 hours with small changes in operating parameters. The discharge has experienced 10 shutdowns during the test, all of which were due to test facility failures or expellant replenishment. In all cases, the cathode was re-ignited at approximately 42 volts and resumed typical operation. This test represents the longest demonstrated stable operation of a high current (greater than 1 A) xenon hollow cathode reported to date.

Rearing and estimation of life-cycle parameters of the tubicifid worm Branchiura sowerbyi: application to ecotoxicity testing.

PubMed

Ducrot, Virginie; Péry, Alexandre R R; Quéau, Hervé; Mons, Raphaël; Lafont, Michel; Garric, Jeanne

2007-10-01

This paper provides original collection, acclimatizing, rearing and toxicity test methods for the freshwater worm Branchiura sowerbyi, an alternative species to Tubifex tubifex for ecotoxicity evaluation of sediments. Influence of the substrate, type of food, and feeding level on individual performances was assessed in short-term tests, in order to set up optimal culture and test conditions. Low-size particles and high organic matter content favoured the growth and reproduction of B. sowerbyi. The relative contribution of sediments and fish food to the individual food intake was assessed using a foraging efficiency model based upon the dynamic energy budget theory. Individual performances were optimal when the substrate plus fish food provided the energy equivalent to 5 mg Tetramin per worm per day, which is the ad libitum food level for adults at 21 degrees C. The life-cycle of the worm was fully characterized using a life-cycle test conducted under the previously defined optimal conditions. Hatching rates were low (32%), whereas newborn and juveniles exhibited high survival (>80%) and growth (2.4 mg/day in juveniles) rates. Age at puberty was low (60 days) when compared to the maximal life span (1100 days) as predicted using a Weibull model. Adults reproduced every other month with a constant fecundity (0.16 cocoon/worm/day). The mean values of the life-cycle parameters and their variability and reproducibility among laboratory studies were discussed in order to identify relevant endpoints to be used in ecotoxicity tests. Survival, juvenile growth, and fecundity may constitute suitable test endpoints, whereas hatching rate and adult growth should not be used as endpoints in B. sowerbyi.

Rolling-element fatigue life of silicon nitride balls: Preliminary test results

NASA Technical Reports Server (NTRS)

Parker, R. J.; Zaretsky, E. V.

1972-01-01

Hot pressed silicon nitride was evaluated as a rolling element bearing material. The five-ball fatigue tester was used to test 12.7 mm (0.500 in.) diameter balls at a maximum Hertz stress of 800,000 psi at a race temperature of 130 F. The fatigue spalls in the silicon nitride resembled those in typical bearing steels. The ten-percent fatigue life of the silicon nitride balls was approximately one-eighth to one-fifth that of typical bearing steels (52100 and M-50). The load capacity of the silicon nitride was approximately one-third that of typical bearing steels. The load capacity of the silicon nitride was significantly higher than previously tested ceramic materials for rolling element bearings.

Life testing of secondary silver-zinc cells for the orbiting maneuvering vehicle

NASA Technical Reports Server (NTRS)

Brewer, Jeffrey C.; Doreswamy, Rajiv; Jackson, Lorna G.

1990-01-01

Over the past 5 years, extensive testing has been performed at the Marshall Space Flight Center (MSFC) on a variety of secondary (rechargeable) silver-zinc (Ag-Zn) cells for the Orbital Maneuvering Vehicle (OMV). The first tests performed were to determine the feasibility of using such a cell in a long-life (18-month), low-Earth-orbit (LEO) application. Results from these tests were promising, so testing continued with a 250-Ah cell that was specifically designed for this type of application. Once again, results from the tests were promising. Following a review of the data from these previous tests, slight modifications to the 250-Ah design were necessary to alleviate problem areas. Currently, MSFC is testing a 350-Ah design that has incorporated these changes and is the baseline design for the OMV. This test began in mid-November, 1989, and will be complete in the spring of 1991, barring any substantial offline time. A report is presented on the preliminary results from the first few months of this test and they are compared to results obtained in previous tests done at MFSC.

Modified ACES Portable Life Support Integration, Design, and Testing for Exploration Missions

NASA Technical Reports Server (NTRS)

Kelly, Cody

2014-01-01

NASA's next generation of exploration missions provide a unique challenge to designers of EVA life support equipment, especially in a fiscally-constrained environment. In order to take the next steps of manned space exploration, NASA is currently evaluating the use of the Modified ACES (MACES) suit in conjunction with the Advanced Portable Life Support System (PLSS) currently under development. This paper will detail the analysis and integration of the PLSS thermal and ventilation subsystems into the MACES pressure garment, design of prototype hardware, and hardware-in-the-loop testing during the spring 2014 timeframe. Prototype hardware was designed with a minimal impact philosophy in order to mitigate design constraints becoming levied on either the advanced PLSS or MACES subsystems. Among challenges faced by engineers were incorporation of life support thermal water systems into the pressure garment cavity, operational concept definition between vehicle/portable life support system hardware, and structural attachment mechanisms while still enabling maximum EVA efficiency from a crew member's perspective. Analysis was completed in late summer 2013 to 'bound' hardware development, with iterative analysis cycles throughout the hardware development process. The design effort will cumulate in the first ever manned integration of NASA's advanced PLSS system with a pressure garment originally intended primarily for use in a contingency survival scenario.

Alternatives to the fish early life-stage test: Developing a conceptual model for early fish development

EPA Science Inventory

Chronic fish toxicity is a key parameter for hazard classification and environmental risk assessment of chemicals, and the OECD 210 fish early life-stage (FELS) test is the primary guideline test used for various international regulatory programs. There exists a need to develop ...

Key results of battery performance and life tests at Argonne National Laboratory

NASA Astrophysics Data System (ADS)

Deluca, W. H.; Gillie, K. R.; Kulaga, J. E.; Smaga, J. A.; Tummillo, A. F.; Webster, C. E.

1991-12-01

Advanced battery technology evaluations are performed under simulated electric vehicle operating conditions at Argonne National Laboratory's & Diagnostic Laboratory (ADL). The ADL provide a common basis for both performance characterization and life evaluation with unbiased application of tests and analyses. This paper summarizes the performance characterizations and life evaluations conducted in 1991 on twelve single cells and eight 3- to 360-cell modules that encompass six battery technologies (Na/S, Li/MS, Ni/MH, Zn/Br, Ni/Fe, and Pb-Acid). These evaluations were performed for the Department of Energy, Office of Transportation Technologies, Electric and Hybrid Propulsion Division. The results measure progress in battery R & D programs, compare battery technologies, and provide basic data for modeling and continuing R & D to battery users, developers, and program managers.

High Pressure Hydrogen Pressure Relief Devices: Accelerated Life Testing and Application Best Practices

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

Burgess, Robert M.; Post, Matthew B.; Buttner, William J.

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 particularmore » 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.« less

Mir Cooperative Solar Array Project Accelerated Life Thermal Cycling Test

NASA Technical Reports Server (NTRS)

Hoffman, David J.; Scheiman, David A.

1996-01-01

The Mir Cooperative Solar Array (MCSA) project was a joint U.S./Russian effort to build a photovoltaic (PV) solar array and deliver it to the Russian space station Mir. The MCSA will be used to increase the electrical power on Mir and provide PV array performance data in support of Phase 1 of the International Space Station. The MCSA was brought to Mir by space shuttle Atlantis in November 1995. This report describes an accelerated thermal life cycle test which was performed on two samples of the MCSA. In eight months time, two MCSA solar array 'mini' panel test articles were simultaneously put through 24,000 thermal cycles. There was no significant degradation in the structural integrity of the test articles and no electrical degradation, not including one cell damaged early and removed from consideration. The nature of the performance degradation caused by this one cell is briefly discussed. As a result of this test, changes were made to improve some aspects of the solar cell coupon-to-support frame interface on the flight unit. It was concluded from the results that the integration of the U.S. solar cell modules with the Russian support structure would be able to withstand at least 24,000 thermal cycles (4 years on-orbit). This was considered a successful development test.

A Confirmatory Factor Analysis of the Life Orientation Test-Revised with Competitive Athletes

ERIC Educational Resources Information Center

Appaneal, Renee N.

2012-01-01

Current reviews outside of sport indicate that the Life Orientation Test-Revised (LOT-R) items load on two separate factors (optimism and pessimism) and, therefore, should be treated as independent constructs. However, researchers in the sport sciences continue to use the single composite score reflecting a unidimensional definition of optimism.…

Life testing of reflowed and reworked advanced CCGA surface mount packages in harsh thermal environments

NASA Astrophysics Data System (ADS)

Ramesham, Rajeshuni

2013-03-01

Life testing/qualification of reflowed (1st reflow) and reworked (1st reflow, 1st removal, and then 1st rework) advanced ceramic column grid array (CCGA) surface mount interconnect electronic packaging technologies for future flight projects has been studied to enhance the mission assurance of JPL-NASA projects. The reliability of reworked/reflowed surface mount technology (SMT) packages is very important for short-duration and long-duration deep space harsh extreme thermal environmental missions. The life testing of CCGA electronic packages under extreme thermal environments (for example: -185°C to +125°C) has been performed with reference to various JPL/NASA project requirements which encompass the temperature range studied. The test boards of reflowed and reworked CCGA packages (717 Xilinx package, 624, 1152, and 1272 column Actel Packages) were selected for the study to survive three times the total number of expected temperature cycles resulting from all environmental and operational exposures occurring over the life of the flight hardware including all relevant manufacturing, ground operations, and mission phases or cycles to failure to assess the life of the hardware. Qualification/life testing was performed by subjecting test boards to the environmental harsh temperature extremes and assessing any structural failures, mechanical failures or degradation in electrical performance solder-joint failures due to either overstress or thermal cycle fatigue. The large, high density, high input/output (I/O) electronic interconnect SMT packages such as CCGA have increased usage in avionics hardware of NASA projects during the last two decades. The test boards built with CCGA packages are expensive and often require a rework to replace a reflowed, reprogrammed, failed, redesigned, etc., CCGA packages. Theoretically speaking, a good rework process should have similar temperature-time profile as that used for the original manufacturing process of solder reflow. A

Rare Earth or Cosmic Zoo: Testing the Frequency of Complex Life in the Universe

NASA Astrophysics Data System (ADS)

Bains, W.; Schulze-Makuch, D.

2017-02-01

We propose how to test between two major hypotheses about the frequency of life in the universe (Rare Earth and Cosmic Zoo) using future remote sensing capabilities targeted at exoplanets and site visits of planetary bodies in our solar system.

Evaluation program for secondary spacecraft cells: Seventeenth annual report of cycle life test

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1981-01-01

Acceptance tests were conducted on nickel cadmium, silver cadmium, and silver zinc cells to insure that all cells put into the life cycle program meet the specifications outlined in the respective purchase contracts. Statistical information is presented on cell performance characteristics and limitations. Weaknesses discovered in cell design are reported and aid in research and development efforts toward improving the reliability of space batteries. Battery weaknesses encountered in satellite programs such as IMP, NIMBUS, OGO, OAO, SAS, and TETR were studied and remedied through special tests.

Results of the mission profile life test. [for J-series mercury ion engines

NASA Technical Reports Server (NTRS)

Bechtel, R. T.; Trump, G. E.; James, E. L.

1982-01-01

Seven J series 30-cm diameter thrusters have been tested in segments of up to 5,070 hr, for 14,541 hr in the Mission Profile Life Test facility. Test results have indicated the basic thruster design to be consistent with the lifetime goal of 15,000 hr at 2-A beam. The only areas of concern identified which appear to require additional verification testing involve contamination of mercury propellant isolators, which may be due to facility constituents, and the ability of specially covered surfaces to contain sputtered material and prevent flake formation. The ability of the SCR, series resonant inverter power processor to operate the J series thruster and autonomous computer control of the thruster/processor system were demonstrated.

Impact of syncope on quality of life: validation of a measure in patients undergoing tilt testing.

PubMed

Nave-Leal, Elisabete; Oliveira, Mário; Pais-Ribeiro, José; Santos, Sofia; Oliveira, Eunice; Alves, Teresa; Cruz Ferreira, Rui

2015-03-01

Recurrent syncope has a significant impact on quality of life. The development of measurement scales to assess this impact that are easy to use in clinical settings is crucial. The objective of the present study is a preliminary validation of the Impact of Syncope on Quality of Life questionnaire for the Portuguese population. The instrument underwent a process of translation, validation, analysis of cultural appropriateness and cognitive debriefing. A population of 39 patients with a history of recurrent syncope (>1 year) who underwent tilt testing, aged 52.1 ± 16.4 years (21-83), 43.5% male, most in active employment (n=18) or retired (n=13), constituted a convenience sample. The resulting Portuguese version is similar to the original, with 12 items in a single aggregate score, and underwent statistical validation, with assessment of reliability, validity and stability over time. With regard to reliability, the internal consistency of the scale is 0.9. Assessment of convergent and discriminant validity showed statistically significant results (p<0.01). Regarding stability over time, a test-retest of this instrument at six months after tilt testing with 22 patients of the sample who had not undergone any clinical intervention found no statistically significant changes in quality of life. The results indicate that this instrument is of value for assessing quality of life in patients with recurrent syncope in Portugal. Copyright © 2014 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

Life test result of Ricor K529N 1watt linear cryocooler

NASA Astrophysics Data System (ADS)

Nachman, Ilan; Veprik, Alexander; Pundak, Nachman

2007-04-01

The authors summarize the results of the accelerated life testing of the Ricor type K529N 1 Watt linear split Stirling cooler. The test was conducted in the period 2003-2006, during which the cooler accumulated in excess of 27,500 working hours at an elevated ambient temperature, which is equivalent to 45,000 hours at normal ambient conditions, and performed about 7,500 operational cycles including cooldown and steady-state phases. The cryocooler performances were assessed through the cooldown time and power consumption; no visible degradation in performances was observed. After the cooler failure and the compressor disassembling, an electrical short was discovered in the driving coil. The analysis has shown that the wire insulating varnish was not suitable for such elevated temperatures. It is important to note that the cooler under test was taken from the earliest engineering series; in the later manufacturing line military grade wire with high temperature insulation was used, no customer complaints have been recorded in this instance Special attention was paid to the thorough examination of the technical condition of the critical components of the cooler interior. In particular, dynamic piston-cylinder seal, flying leads, internal O-rings and driving coil were examined in the compressor. As to the cold head, we focused on studying the conditions of the dynamic bushing-plunger seal, O-rings and displacer-regenerator. In addition, a leak test was performed to assess the condition of the metallic crushed seals. From the analysis, the authors draw the conclusion that the cooler design is adequate for long life performance (in excess of 20,000 working hours) applications.

Fatigue testing of a NiTi rotary instrument. Part 1: Strain-life relationship.

PubMed

Cheung, G S P; Darvell, B W

2007-08-01

To examine the fatigue behaviour using a strain-life approach, and to determine the effect of water on the fatigue life of a NiTi rotary instrument. Instruments of one brand of NiTi engine-file (size 25, ProFile 0.04 and 0.06) were subjected to rotational bending either in air or under water, the number of revolutions to fracture (N(f)) being recorded using an optical counter and an electronic break-detection circuit. The effective surface strain amplitude (epsilon(a)) for each specimen was determined from the curvature of the instrument (on a photograph) and the diameter of the fracture cross-section (from a scanning electron micrograph of the fracture surface). Strain was plotted against fatigue life and the low-cycle fatigue (LCF) region identified. Values were examined using two-way analysis of variance for difference between various instrument-environment combinations. A total of 212 instruments were tested. A strain-life relationship typical of metals was found. N(f) declined with an inverse power function dependence on epsilon(a). A fatigue limit was present at about 0.7% strain. The apparent fatigue-ductility exponent, a material constant for the LCF life of metals, was found to be between -0.45 and -0.55. There was a significant effect of the environmental condition on the LCF life, water being more detrimental than air. The fatigue behaviour of NiTi rotary instrument is typical of most metals, provided that the analysis is based on the surface strain amplitude, and showed a high-cycle and a LCF region. The LCF life is adversely affected by water.

Mediation and Moderation: Testing Relationships between Symptom Status, Functional Health, and Quality of Life in HIV Patients

ERIC Educational Resources Information Center

Ryu, Ehri; West, Stephen G.; Sousa, Karen H.

2009-01-01

We extended Wilson and Cleary's (1995) health-related quality of life model to examine the relationships among symptom status (Symptoms), functional health (Disability), and quality of life (QOL). Using a community sample (N = 956) of male HIV positive patients, we tested a mediation model in which the relationship between Symptoms and QOL is…

International Space Station Environmental Control and Life Support System On-Orbit Station Development Test Objective Status

NASA Technical Reports Server (NTRS)

Williams, David E.; Lewis, John F.; Gentry, Gregory

2003-01-01

The International Space Station (ISS) Environmental Control and Life Support (ECLS) system includes regenerative and non-regenerative technologies that provide the basic life support functions to support the crew, while maintaining a safe and habitable shirtsleeve environment. This paper provides a summary of the ECLS System On-Orbit Station Development Test Objective (SDTO) status from the start of assembly until the end of February 2003.

Design, construction and long life endurance testing of cathode assemblies for use in microwave high-power transmitting tubes

NASA Technical Reports Server (NTRS)

Batra, R.; Marino, D.

1986-01-01

The cathode life test program sponsored by NASA Lewis Research Center at Watkins-Johnson Company has been in continuous operation since 1972. Its primary objective has been to evaluate the long life capability of barium dispenser cathodes to produce emission current densities of 2 A sq. cm. or more in an operational environment simulating that of a highpower microwave tube. The life test vehicles were equipped with convergent flow electron guns, drift space tubes with solenoid magnets for electron beam confinement and water-cooled depressed collectors. A variety of cathode types has been tested, including GE Tungstate, Litton Impregnated, Philips Type B and M, Semicon types S and M, and Spectra-Mat Type M. Recent emphasis has been on monitoring the performance of Philips Type M cathodes at 2 A sq. cm. and Sprectra-Mat and Semicon Type M cathodes at 4 A sq. cm. These cathodes have been operated at a constant current of 616 mA and a cathode anode voltage on the order of 10 kV. Cathode temperatures were maintained at 1010 C true as measured from black body holes in the backs of the cathodes. This report presents results of the cathode life test program from July l982 through April l986. The results include hours of operation and performance data in the form of normalized emission current density versus temperature curves (Miram plots).

Overview of RICOR's reliability theoretical analysis, accelerated life demonstration test results and verification by field data

NASA Astrophysics Data System (ADS)

Vainshtein, Igor; Baruch, Shlomi; Regev, Itai; Segal, Victor; Filis, Avishai; Riabzev, Sergey

2018-05-01

The growing demand for EO applications that work around the clock 24hr/7days a week, such as in border surveillance systems, emphasizes the need for a highly reliable cryocooler having increased operational availability and optimized system's Integrated Logistic Support (ILS). In order to meet this need, RICOR developed linear and rotary cryocoolers which achieved successfully this goal. Cryocoolers MTTF was analyzed by theoretical reliability evaluation methods, demonstrated by normal and accelerated life tests at Cryocooler level and finally verified by field data analysis derived from Cryocoolers operating at system level. The following paper reviews theoretical reliability analysis methods together with analyzing reliability test results derived from standard and accelerated life demonstration tests performed at Ricor's advanced reliability laboratory. As a summary for the work process, reliability verification data will be presented as a feedback from fielded systems.

Revision and psychometric testing of the City of Hope Quality of Life-Ostomy Questionnaire.

PubMed

Grant, Marcia; Ferrell, Betty; Dean, Grace; Uman, Gwen; Chu, David; Krouse, Robert

2004-10-01

Ostomies may be performed for bowel or urinary diversion, and occur in both cancer and non-cancer patients. Impact on physical, psychological, social and spiritual well-being is not unexpected, but has been minimally described in the literature. The City of Hope Quality of Life (COH-QOL)-Ostomy Questionnaire is an adult patient self-report instrument designed to assess quality of life. This report focuses on the revision and psychometric testing of this questionnaire. The revised COH-QOL-Ostomy Questionnaire involved in-depth patient interviews and expert panel review. The format consisted of a 13-item disease and demographic section, a 34-item forced-choice section, and a 41-item linear analogue scaled section. A mailed survey to California members of the United Ostomy Association resulted in a 62% response rate (n = 1513). Factor analysis was conducted to refine the instrument. Construct validity involved testing a number of hypotheses identifying contrasting groups. Factor analysis confirmed the conceptual framework. Reliability of subscales ranged from 0.77 to 0.90. The questionnaire discriminated between subpopulations with specific concerns. Overall, the analyses provide evidence for the validity and reliability of the COH-QOL-Ostomy Questionnaire as a comprehensive, multidimensional self-report questionnaire for measuring quality of life in patients with intestinal ostomies.

Space Station Environmental Control and Life Support System Test Facility at Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Springer, Darlene

1989-01-01

Different aspects of Space Station Environmental Control and Life Support System (ECLSS) testing are currently taking place at Marshall Space Flight Center (MSFC). Unique to this testing is the variety of test areas and the fact that all are located in one building. The north high bay of building 4755, the Core Module Integration Facility (CMIF), contains the following test areas: the Subsystem Test Area, the Comparative Test Area, the Process Material Management System (PMMS), the Core Module Simulator (CMS), the End-use Equipment Facility (EEF), and the Pre-development Operational System Test (POST) Area. This paper addresses the facility that supports these test areas and briefly describes the testing in each area. Future plans for the building and Space Station module configurations will also be discussed.

Life satisfaction and its correlates among college students in China: a test of social reference theory.

PubMed

Zhang, Jie; Zhao, Sibo; Lester, David; Zhou, Chengchao

2014-08-01

To study life satisfaction and to test the role of social reference in determining the degree of life satisfaction, we examined a large sample of undergraduate students in China for the correlates of campus life satisfaction. A questionnaire survey was administered at a university and the final sample consisted of 439 respondents aged between 17 and 24 years, from all over the country, and studying different subjects. It was found that freshman students tended to score higher on their life satisfaction than students in other grades and the college students' life satisfaction was positively related to female gender, self-esteem, social support, and the liberal attitudes on female gender roles, but negatively correlated with depression and suicidal ideation. Contrary to common beliefs, students from an urban area or from better-off families were not necessarily more satisfied with current life than those students coming from the countryside or low income families. The findings were accounted for by the social reference theory and in this case college students' campus life satisfaction is basically affected by their pre-college life quality as a reference. Copyright © 2013 Elsevier B.V. All rights reserved.

Design, construction and long life endurance testing of cathode assemblies for use in microwave high-power transmitting tubes

NASA Technical Reports Server (NTRS)

Gorshe, R.

1982-01-01

The ability of state of the art cathode types to produce current densities of 2A/sq cm, respectively, over a minimum designed life of 30,000 hours of continuous operation without failures was demonstrated. The performance of the state of the art cathode types was evaluated by endurance testing while operating under identical electrical geometrical, and vacuum conditions that realistically duplicate the operating conditions present in a transmitter tube. Although there has been considerable life testing done on high current density types of cathodes, these have beem primarily limited to diodes. A diode and high power microwave tube are grossly different devices. A comparison of these two devices is provided. A diode and high power microwave tube are quite different; one could therefore assume different internal environments, especially in the cathode region. Therefore, in order to establish life capabilities of the cathodes just mentioned, they should be tested in a vehicle which has an internal environment similar to that of a high power microwave tube.

Results of Accelerated Life Testing of LCLS-II Cavity Tuner Motor

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

Huque, Naeem; Daly, Edward; Pischalnikov, Yuriy

An Accelerated Life Test (ALT) of the Phytron stepper motor used in the LCLS-II cavity tuner has been conducted at JLab. Since the motor will reside inside the cryomodule, any failure would lead to a very costly and arduous repair. As such, the motor was tested for the equivalent of 30 lifetimes before being approved for use in the production cryomodules. The 9-cell LCLS-II cavity is simulated by disc springs with an equivalent spring constant. Plots of the motor position vs. tuner position ' measured via an installed linear variable differential transformer (LVDT) ' are used to measure motor motion.more » The titanium spindle was inspected for loss of lubrication. The motor passed the ALT, and is set to be installed in the LCLS-II cryomodules.« less

RESULTS OF ACCELERATED LIFE TESTING OF LCLS-II CAVITY TUNER MOTOR

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

Huque, Naeem; Daly, Edward F.; Pischalnikov, Yuriy

An Accelerated Life Test (ALT) of the Phytron stepper motor used in the LCLS-II cavity tuner has been conducted at JLab. Since the motor will reside inside the cryomodule, any failure would lead to a very costly and arduous repair. As such, the motor was tested for the equivalent of 30 lifetimes before being approved for use in the production cryomodules. The 9-cell LCLS-II cavity is simulated by disc springs with an equivalent spring constant. Plots of the motor position vs. tuner position ' measured via an installed linear variable differential transformer (LVDT) ' are used to measure motor motion.more » The titanium spindle was inspected for loss of lubrication. The motor passed the ALT, and is set to be installed in the LCLS-II cryomodules.« less

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

PubMed

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.

Life test of a xenon hollow cathode for a space plasma contractor

NASA Technical Reports Server (NTRS)

Sarver-Verhey, Timothy R.

1994-01-01

A plasma contacting device using a hollow cathode for plasma production has been baselined for use on the Space Station. This application will require reliable, continuous operation of the cathode at electron emission currents of between 0.75 and 10 A for two years (17,500 hours). In order to validate life-time capability, a hollow cathode, operated in a diode configuration, has been tested for more than 8600 hours of stable discharge operation as of March 30, 1994. This cathode is operated at a steady-state emission current of 12.0 and a fixed xenon flow rate of 4.5 sccm. Discharge voltage and cathode temperature have remained relatively stable at approximately 12.9 V and 1260 C during the test. The test has experienced 7 shutdowns to date. In all instances, the cathode was reignited at about 42 V and resumed stable operation. This test represents the longest demonstration of stable operation of high current (greater than 1A) xenon hollow cathodes reported to date.

Methodology to Improve Design of Accelerated Life Tests in Civil Engineering Projects

PubMed Central

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. PMID:25111800

Voltage stress effects on microcircuit accelerated life test failure rates

NASA Technical Reports Server (NTRS)

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.

A Life Course Perspective on the Relationship between Socio-Economic Status and Health: Testing the Divergence Hypothesis

ERIC Educational Resources Information Center

Prus, Steven G.

2004-01-01

While adults from all socio-economic status (SES) levels generally encounter a decline in health as they grow older, research shows that health status is tied to SES at all stages of life. The dynamics of the relationship between SES and health over the life course of adult Canadians, however, remain largely unexplored. This paper tests the…

Life Shocks and Crime: A Test of the “Turning Point” Hypothesis

PubMed Central

Noonan, Kelly; Reichman, Nancy E.; Schwartz-Soicher, Ofira

2012-01-01

Other researchers have posited that important events in men’s lives—such as employment, marriage, and parenthood—strengthen their social ties and lead them to refrain from crime. A challenge in empirically testing this hypothesis has been the issue of self-selection into life transitions. This study contributes to this literature by estimating the effects of an exogenous life shock on crime. We use data from the Fragile Families and Child Wellbeing Study, augmented with information from hospital medical records, to estimate the effects of the birth of a child with a severe health problem on the likelihood that the infant’s father engages in illegal activities. We conduct a number of auxiliary analyses to examine exogeneity assumptions. We find that having an infant born with a severe health condition increases the likelihood that the father is convicted of a crime in the three-year period following the birth of the child, and at least part of the effect appears to operate through work and changes in parental relationships. These results provide evidence that life events can cause crime and, as such, support the “turning point” hypothesis. PMID:21660628

Family Environments, Adrenarche, and Sexual Maturation: A Longitudinal Test of a Life History Model

ERIC Educational Resources Information Center

Ellis, Bruce J.; Essex, Marilyn J.

2007-01-01

Life history theorists have proposed that humans have evolved to be sensitive to specific features of early childhood environments and that exposure to different environments biases children toward development of different reproductive strategies, including differential pubertal timing. The current research provides a longitudinal test of this…

Correlation of Simulation Examination to Written Test Scores for Advanced Cardiac Life Support Testing: Prospective Cohort Study.

PubMed

Strom, Suzanne L; Anderson, Craig L; Yang, Luanna; Canales, Cecilia; Amin, Alpesh; Lotfipour, Shahram; McCoy, C Eric; Osborn, Megan Boysen; Langdorf, Mark I

2015-11-01

Traditional Advanced Cardiac Life Support (ACLS) courses are evaluated using written multiple-choice tests. High-fidelity simulation is a widely used adjunct to didactic content, and has been used in many specialties as a training resource as well as an evaluative tool. There are no data to our knowledge that compare simulation examination scores with written test scores for ACLS courses. To compare and correlate a novel high-fidelity simulation-based evaluation with traditional written testing for senior medical students in an ACLS course. We performed a prospective cohort study to determine the correlation between simulation-based evaluation and traditional written testing in a medical school simulation center. Students were tested on a standard acute coronary syndrome/ventricular fibrillation cardiac arrest scenario. Our primary outcome measure was correlation of exam results for 19 volunteer fourth-year medical students after a 32-hour ACLS-based Resuscitation Boot Camp course. Our secondary outcome was comparison of simulation-based vs. written outcome scores. The composite average score on the written evaluation was substantially higher (93.6%) than the simulation performance score (81.3%, absolute difference 12.3%, 95% CI [10.6-14.0%], p<0.00005). We found a statistically significant moderate correlation between simulation scenario test performance and traditional written testing (Pearson r=0.48, p=0.04), validating the new evaluation method. Simulation-based ACLS evaluation methods correlate with traditional written testing and demonstrate resuscitation knowledge and skills. Simulation may be a more discriminating and challenging testing method, as students scored higher on written evaluation methods compared to simulation.

A method for predicting the fatigue life of pre-corroded 2024-T3 aluminum from breaking load tests

NASA Astrophysics Data System (ADS)

Gruenberg, Karl Martin

Characterization of material properties is necessary for design purposes and has been a topic of research for many years. Over the last several decades, much progress has been made in identifying metrics to describe fracture mechanics properties and developing procedures to measure the appropriate values. However, in the context of design, there has not been as much success in quantifying the susceptibility of a material to corrosion damage and its subsequent impact on material behavior in the framework of fracture mechanics. A natural next step in understanding the effects of corrosion damage was to develop a link between standard material test procedures and fatigue life in the presence of corrosion. Simply stated, the goal of this investigation was to formulate a cheaper and quicker method for assessing the consequences of corrosion on remaining fatigue life. For this study, breaking load specimens and fatigue specimens of a single nominal gage (0.063″) of aluminum alloy 2024-T3 were exposed to three levels of corrosion. The breaking load specimens were taken from three different material lots, and the fatigue tests were carried out at three stress levels. All failed specimens, both breaking load and fatigue specimens, were examined to characterize the damage state(s) and failure mechanism(s). Correlations between breaking load results and fatigue life results in the presence of corrosion damage were developed using a fracture mechanics foundation and the observed mechanisms of failure. Where breaking load tests showed a decrease in strength due to increased corrosion exposure, the corresponding set of fatigue tests showed a decrease in life. And where breaking load tests from different specimen orientations exhibited similar levels of strength, the corresponding set of fatigue specimens showed similar lives. The spread from shortest to longest fatigue lives among the different corrosion conditions decreased at the higher stress levels. Life predictions based

Development of an Accelerated Test Design for Predicting the Service Life of the Solar Array at Mead, Nebraska

NASA Technical Reports Server (NTRS)

Gaines, G. B.; Thomas, R. E.; Noel, G. T.; Shilliday, T. S.; Wood, V. E.; Carmichael, D. C.

1979-01-01

An accelerated life test is described which was developed to predict the life of the 25 kW photovoltaic array installed near Mead, Nebraska. A quantitative model for accelerating testing using multiple environmental stresses was used to develop the test design. The model accounts for the effects of thermal stress by a relation of the Arrhenius form. This relation was then corrected for the effects of nonthermal environmental stresses, such as relative humidity, atmospheric pollutants, and ultraviolet radiation. The correction factors for the nonthermal stresses included temperature-dependent exponents to account for the effects of interactions between thermal and nonthermal stresses on the rate of degradation of power output. The test conditions, measurements, and data analyses for the accelerated tests are presented. Constant-temperature, cyclic-temperature, and UV types of tests are specified, incorporating selected levels of relative humidity and chemical contamination and an imposed forward-bias current and static electric field.

Phase Change Material Heat Exchanger Life Test

NASA Technical Reports Server (NTRS)

Lillibridge, Sean; Stephan, Ryan

2009-01-01

Low Lunar Orbit (LLO) poses unique thermal challenges for the orbiting space craft, particularly regarding the performance of the radiators. The IR environment of the space craft varies drastically from the light side to the dark side of the moon. The result is a situation where a radiator sized for the maximal heat load in the most adverse situation is subject to freezing on the dark side of the orbit. One solution to this problem is to implement Phase Change Material (PCM) Heat Exchangers. PCM Heat Exchangers act as a "thermal capacitor," storing thermal energy when there is too much being produced by the space craft to reject to space, and then feeding that energy back into the thermal loop when conditions are more favorable. Because they do not use an expendable resource, such as the feed water used by sublimators and evaporators, PCM Heat Exchangers are ideal for long duration LLO missions. In order to validate the performance of PCM Heat Exchangers, a life test is being conducted on four n-Pentadecane, carbon filament heat exchangers. Fluid loop performance, repeatability, and measurement of performance degradation over 2500 melt-freeze cycles will be performed.

Space Suit Portable Life Support System (PLSS) 2.0 Human-in-the-Loop (HITL) Testing

NASA Technical Reports Server (NTRS)

Watts, Carly; Vogel, Matthew

2016-01-01

The space suit Portable Life Support System (PLSS) 2.0 represents the second integrated prototype developed and tested to mature a design that uses advanced technologies to reduce consumables, improve robustness, and provide additional capabilities over the current state of the art. PLSS 2.0 was developed in 2012, with extensive functional evaluations and system performance testing through mid-2014. In late 2014, PLSS 2.0 was integrated with the Mark III space suit in an ambient laboratory environment to facilitate manned testing, designated PLSS 2.0 Human-in-the-Loop (HITL) testing, in which the PLSS prototype performed the primary life support functions, including suit pressure regulation, ventilation, carbon dioxide control, and cooling of the test subject and PLSS avionics. The intent of this testing was to obtain subjective test subject feedback regarding qualitative aspects of PLSS 2.0 performance such as thermal comfort, sounds, smells, and suit pressure fluctuations due to the cycling carbon dioxide removal system, as well as to collect PLSS performance data over a range of human metabolic rates from 500-3000 Btu/hr. Between October 27 and December 18, 2014, nineteen two-hour simulated EVA test points were conducted in which suited test subjects walked on a treadmill to achieve a target metabolic rate. Six test subjects simulated nominal and emergency EVA conditions with varied test parameters including metabolic rate profile, carbon dioxide removal control mode, cooling water temperature, and Liquid Cooling and Ventilation Garment (state of the art or prototype). The nineteen test points achieved more than 60 hours of test time, with 36 hours accounting for simulated EVA time. The PLSS 2.0 test article performed nominally throughout the test series, confirming design intentions for the advanced PLSS. Test subjects' subjective feedback provided valuable insight into thermal comfort and perceptions of suit pressure fluctuations that will influence future

Accelerated life tests of specimen heat pipe from Communication Technology Satellite (CTS) project

NASA Technical Reports Server (NTRS)

Tower, L. K.; Kaufman, W. B.

1977-01-01

A gas-loaded variable conductance heat pipe of stainless steel with methanol working fluid identical to one now on the CTS satellite was life tested in the laboratory at accelerated conditions for 14 200 hours, equivalent to about 70 000 hours at flight conditions. The noncondensible gas inventory increased about 20 percent over the original charge. The observed gas increase is estimated to increase operating temperature by about 2.2 C, insufficient to harm the electronic gear cooled by the heat pipes in the satellite. Tests of maximum heat input against evaporator elevation agree well with the manufacturer's predictions.

Development, modelling, and pilot testing of a complex intervention to support end-of-life care provided by Danish general practitioners.

PubMed

Winthereik, Anna Kirstine; Neergaard, Mette Asbjoern; Jensen, Anders Bonde; Vedsted, Peter

2018-06-20

Most patients in end-of-life with life-threatening diseases prefer to be cared for and die at home. Nevertheless, the majority die in hospitals. GPs have a pivotal role in providing end-of-life care at patients' home, and their involvement in the palliative trajectory enhances the patient's possibility to stay at home. The aim of this study was to develop and pilot-test an intervention consisting of continuing medical education (CME) and electronic decision support (EDS) to support end-of-life care in general practice. We developed an intervention in line with the first phases of the guidelines for complex interventions drawn up by the Medical Research Council. Phase 1 involved the development of the intervention including identification of key barriers to provision of end-of-life care for GPs and of facilitators of change. Furthermore the actual modelling of two components: CME meeting and EDS. Phase 2 focused on pilot-testing and intervention assessment by process evaluation. In phase 1 lack of identification of patients at the end of life and limited palliative knowledge among GPs were identified as barriers. The CME meeting and the EDS were developed. The CME meeting was a four-hour educational meeting performed by GPs and specialists in palliative care. The EDS consisted of two parts: a pop-up window for each patient with palliative needs and a list of all patients with palliative needs in the practice. The pilot testing in phase 2 showed that the CME meeting was performed as intended and 120 (14%) of the GPs in the region attended. The EDS was integrated in existing electronic records but was shut down early for external reasons; 50 (5%) GPs signed up. The pilot-testing demonstrated a need to strengthen the implementation as attending rate was low in the current set-up. We developed a complex intervention to support GPs in providing end-of-life care. The pilot-test showed general acceptance of the CME meetings. The EDS was shut down early and needs further

Design of the fiber optic support system and fiber bundle accelerated life test for VIRUS

NASA Astrophysics Data System (ADS)

Soukup, Ian M.; Beno, Joseph H.; Hayes, Richard J.; Heisler, James T.; Mock, Jason R.; Mollison, Nicholas T.; Good, John M.; Hill, Gary J.; Vattiat, Brian L.; Murphy, Jeremy D.; Anderson, Seth C.; Bauer, Svend M.; Kelz, Andreas; Roth, Martin M.; Fahrenthold, Eric P.

2010-07-01

The quantity and length of optical fibers required for the Hobby-Eberly Telescope* Dark Energy eXperiment (HETDEX) create unique fiber handling challenges. For HETDEX‡, at least 33,600 fibers will transmit light from the focal surface of the telescope to an array of spectrographs making up the Visible Integral-Field Replicable Unit Spectrograph (VIRUS). Up to 96 Integral Field Unit (IFU) bundles, each containing 448 fibers, hang suspended from the telescope's moving tracker located more than 15 meters above the VIRUS instruments. A specialized mechanical system is being developed to support fiber optic assemblies onboard the telescope. The discrete behavior of 448 fibers within a conduit is also of primary concern. A life cycle test must be conducted to study fiber behavior and measure Focal Ratio Degradation (FRD) as a function of time. This paper focuses on the technical requirements and design of the HETDEX fiber optic support system, the electro-mechanical test apparatus for accelerated life testing of optical fiber assemblies. Results generated from the test will be of great interest to designers of robotic fiber handling systems for major telescopes. There is concern that friction, localized contact, entanglement, and excessive tension will be present within each IFU conduit and contribute to FRD. The test apparatus design utilizes six linear actuators to replicate the movement of the telescope over 65,000 accelerated cycles, simulating five years of actual operation.

Development of a Complete Life Cycle Sediment Toxicity Test for the Sheepshead Minnow (Cyprinodon variegatus)

EPA Science Inventory

Existing sediment toxicity test methods are limited to acute and chronic exposure of invertebrates and acute exposure of vertebrates, with limited guidance on the chronic exposure of vertebrates, specifically fishes. A series of life stage-specific studies were conducted to dete...

Working memory and inhibitory control across the life span: Intrusion errors in the Reading Span Test.

PubMed

Robert, Christelle; Borella, Erika; Fagot, Delphine; Lecerf, Thierry; de Ribaupierre, Anik

2009-04-01

The aim of this study was to examine to what extent inhibitory control and working memory capacity are related across the life span. Intrusion errors committed by children and younger and older adults were investigated in two versions of the Reading Span Test. In Experiment 1, a mixed Reading Span Test with items of various list lengths was administered. Older adults and children recalled fewer correct words and produced more intrusions than did young adults. Also, age-related differences were found in the type of intrusions committed. In Experiment 2, an adaptive Reading Span Test was administered, in which the list length of items was adapted to each individual's working memory capacity. Age groups differed neither on correct recall nor on the rate of intrusions, but they differed on the type of intrusions. Altogether, these findings indicate that the availability of attentional resources influences the efficiency of inhibition across the life span.

Measurement techniques and instruments suitable for life-prediction testing of photovoltaic arrays

NASA Technical Reports Server (NTRS)

Noel, G. T.; Sliemers, F. A.; Deringer, G. C.; Wood, V. E.; Wilkes, K. E.; Gaines, G. B.; Carmichael, D. C.

1978-01-01

Array failure modes, relevant materials property changes, and primary degradation mechanisms are discussed as a prerequisite to identifying suitable measurement techniques and instruments. Candidate techniques and instruments are identified on the basis of extensive reviews of published and unpublished information. These methods are organized in six measurement categories - chemical, electrical, optical, thermal, mechanical, and other physicals. Using specified evaluation criteria, the most promising techniques and instruments for use in life prediction tests of arrays were selected.

Use of Life-Test Data Analysis Methodology for Analyzing Undesirable Habitual Behavior

DTIC Science & Technology

1979-07-06

of times to failu’e for the hardware subjected to life test. In the present context it has been round that detoxification provides a time that one may...the fact that resulting data generated by a single individual tend to belong to a classical distribution of times to failure. Detoxification is used...drug and its immediate toxic effects from his or her body and brain. Detoxification in this sense may result from inpatient or outpatient treatment at a

A Tale of Two Chambers: Iterative Approaches and Lessons Learned from Life Support Systems Testing in Altitude Chambers

NASA Technical Reports Server (NTRS)

Callini, Gianluca

2016-01-01

The drive for the journey to Mars is in a higher gear than ever before. We are developing new spacecraft and life support systems to take humans to the Red Planet. The journey that development hardware takes before its final incarnation in a fully integrated spacecraft can take years, as is the case for the Orion environmental control and life support system (ECLSS). Through the Pressure Integrated Suit Test (PIST) series, NASA personnel at Johnson Space Center have been characterizing the behavior of a closed loop ECLSS in the event of cabin depressurization. This kind of testing - one of the most hazardous activities performed at JSC - requires an iterative approach, increasing in complexity and hazards). The PIST series, conducted in the Crew and Thermal Systems Division (CTSD) 11-ft Chamber, started with unmanned test precursors before moving to a human-in-the-loop phase, and continues to evolve with the eventual goal of a qualification test for the final system that will be installed on Orion. Meanwhile, the Human Exploration Spacecraft Testbed for Integration and Advancement (HESTIA) program is an effort to research and develop technologies that will work in concert to support habitation on Mars. September 2015 marked the first unmanned HESTIA test, with the goal of characterizing how ECLSS technologies work together in a closed environment. HESTIA will culminate in crewed testing, but it can benefit from the lessons learned from another test that is farther ahead in its development and life cycle. Discussing PIST and HESTIA, this paper illustrates how we approach testing, the kind of information that facility teams need to ensure efficient collaborations and successful testing, and how we can apply what we learn to execute future tests.

Life-Cycle Assessments of Selected NASA Ground-Based Test Facilities

NASA Technical Reports Server (NTRS)

Sydnor, George Honeycutt

2012-01-01

In the past two years, two separate facility-specific life cycle assessments (LCAs) have been performed as summer student projects. The first project focused on 13 facilities managed by NASA s Aeronautics Test Program (ATP), an organization responsible for large, high-energy ground test facilities that accomplish the nation s most advanced aerospace research. A facility inventory was created for each facility, and the operational-phase carbon footprint and environmental impact were calculated. The largest impacts stemmed from electricity and natural gas used directly at the facility and to generate support processes such as compressed air and steam. However, in specialized facilities that use unique inputs like R-134a, R-14, jet fuels, or nitrogen gas, these sometimes had a considerable effect on the facility s overall environmental impact. The second LCA project was conducted on the NASA Ames Arc Jet Complex and also involved creating a facility inventory and calculating the carbon footprint and environmental impact. In addition, operational alternatives were analyzed for their effectiveness at reducing impact. Overall, the Arc Jet Complex impact is dominated by the natural-gas fired boiler producing steam on-site, but alternatives were provided that could reduce the impact of the boiler operation, some of which are already being implemented. The data and results provided by these LCA projects are beneficial to both the individual facilities and NASA as a whole; the results have already been used in a proposal to reduce carbon footprint at Ames Research Center. To help future life cycle projects, several lessons learned have been recommended as simple and effective infrastructure improvements to NASA, including better utility metering and data recording and standardization of modeling choices and methods. These studies also increased sensitivity to and appreciation for quantifying the impact of NASA s activities.

A pre-test and post-test study of the physical and psychological effects of out-of-home respite care on caregivers of children with life-threatening conditions.

PubMed

Remedios, Cheryl; Willenberg, Lisa; Zordan, Rachel; Murphy, Andrea; Hessel, Gail; Philip, Jennifer

2015-03-01

Respite services are recommended as an important support for caregivers of children with life-threatening conditions. However, the benefits of respite have not been convincingly demonstrated through quantitative research. To determine the impact of out-of home respite care on levels of fatigue, psychological adjustment, quality of life and relationship satisfaction among caregivers of children with life-threatening conditions. A mixed-methods, pre-test and post-test study A consecutive sample of 58 parental caregivers whose children were admitted to a children's hospice for out-of-home respite over an average of 4 days. Caregivers had below-standard levels of quality of life compared to normative populations. Paired t-tests demonstrated that caregivers' average psychological adjustment scores significantly improved from pre-respite (mean = 13.9, standard error = 0.71) to post-respite (mean = 10.7, standard error = 1); p < 0.001, 95% confidence interval: 1.25-5.11). Furthermore, caregivers' average fatigue scores significantly improved from pre-respite (mean = 14.3, standard error = 0.85) to post-respite (mean = 10.9, standard error = 1.01; p < 0.001, 95% confidence interval: 1.69-7.94), and caregivers' average mental health quality of life scores significantly improved from pre-respite (mean = 44.2, standard error = 1.8) to post-respite (mean = 49.1, standard error = 1.6; p < 0.01, 95% confidence interval: -9.56 to 0.36). Qualitative data showed caregivers sought respite for relief from intensive care provision and believed this was essential to their well-being. Findings indicate the effectiveness of out-of-home respite care in improving the fatigue and psychological adjustment of caregivers of children with life-threatening conditions. Study outcomes inform service provision and future research efforts in paediatric palliative care. © The Author(s) 2015.

Accelerated Life Structural Benchmark Testing for a Stirling Convertor Heater Head

NASA Technical Reports Server (NTRS)

Krause, David L.; Kantzos, Pete T.

2006-01-01

For proposed long-duration NASA Space Science missions, the Department of Energy, Lockheed Martin, Infinia Corporation, and NASA Glenn Research Center are developing a high-efficiency, 110 W Stirling Radioisotope Generator (SRG110). A structurally significant limit state for the SRG110 heater head component is creep deformation induced at high material temperature and low stress level. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and a wealth of creep data is available for the Inconel 718 material of construction. However, the specified atypical thin heater head material is fine-grained with a heat treatment that limits precipitate growth, and little creep property data for this microstructure is available in the literature. In addition, the geometry and loading conditions apply a multiaxial stress state on the component, far from the conditions of uniaxial testing. For these reasons, an extensive experimental investigation is ongoing to aid in accurately assessing the durability of the SRG110 heater head. This investigation supplements uniaxial creep testing with pneumatic testing of heater head-like pressure vessels at design temperature with stress levels ranging from approximately the design stress to several times that. This paper presents experimental results, post-test microstructural analyses, and conclusions for four higher-stress, accelerated life tests. Analysts are using these results to calibrate deterministic and probabilistic analytical creep models of the SRG110 heater head.

Creating a Computer Adaptive Test Version of the Late-Life Function & Disability Instrument

PubMed Central

Jette, Alan M.; Haley, Stephen M.; Ni, Pengsheng; Olarsch, Sippy; Moed, Richard

2009-01-01

Background This study applied Item Response Theory (IRT) and Computer Adaptive Test (CAT) methodologies to develop a prototype function and disability assessment instrument for use in aging research. Herein, we report on the development of the CAT version of the Late-Life Function & Disability instrument (Late-Life FDI) and evaluate its psychometric properties. Methods We employed confirmatory factor analysis, IRT methods, validation, and computer simulation analyses of data collected from 671 older adults residing in residential care facilities. We compared accuracy, precision, and sensitivity to change of scores from CAT versions of two Late-Life FDI scales with scores from the fixed-form instrument. Score estimates from the prototype CAT versus the original instrument were compared in a sample of 40 older adults. Results Distinct function and disability domains were identified within the Late-Life FDI item bank and used to construct two prototype CAT scales. Using retrospective data, scores from computer simulations of the prototype CAT scales were highly correlated with scores from the original instrument. The results of computer simulation, accuracy, precision, and sensitivity to change of the CATs closely approximated those of the fixed-form scales, especially for the 10- or 15-item CAT versions. In the prospective study each CAT was administered in less than 3 minutes and CAT scores were highly correlated with scores generated from the original instrument. Conclusions CAT scores of the Late-Life FDI were highly comparable to those obtained from the full-length instrument with a small loss in accuracy, precision, and sensitivity to change. PMID:19038841

Performance and Life Tests of a Regenerative Blower for EVA Suit Ventilation

NASA Technical Reports Server (NTRS)

Izenson, Mike; Chen, Weibo; Paul, Heather L.; Jennings, Mallory A.

2011-01-01

Ventilation fans for future space suits must meet demanding performance specifications, satisfy stringent safety requirements for operation in an oxygen atmosphere, and be able to increase output to operate in buddy mode. A regenerative blower is an attractive choice due to its ability to meet these requirements at low operating speed. This paper describes progress in the development and testing of a regenerative blower designed to meet requirements for ventilation subsystems in a future space suit Portable Life Support Systems (PLSS). The blower assembly includes a custom-designed motor that has significantly improved in efficiency during this development effort. The blower was tested at both nominal and buddy mode operating points and head/flow performance and power consumption were measured. The blower was operated for over 1000 hours to demonstrate safe operation in an oxygen test loop at prototypical pressures. In addition, the blower demonstrated operation with the introduction of simulated lunar dust.

Sample Processor for Life on Icy Worlds (SPLIce): Design and Test Results

NASA Technical Reports Server (NTRS)

Chinn, Tori N.; Lee, Anthony K.; Boone, Travis D.; Tan, Ming X.; Chin, Matthew M.; McCutcheon, Griffin C.; Horne, Mera F.; Padgen, Michael R.; Blaich, Justin T.; Forgione, Joshua B.;

Facilities and support systems for a 90-day test of a regenerative life support system

NASA Technical Reports Server (NTRS)

Malin, R. L.

1972-01-01

A 90-day test is reported of a regenerative life support system which was completed in a space station simulator. The long duration of the test and the fact that it was manned, imposed rigid reliability and safety requirements on the facility. Where adequate reliability could not be built into essential facility systems, either backup systems or components were provided. Awareness was intensified by: (1) placing signs on every piece of equipment that could affect the test, (2) painting switches on all breaker panels a bright contrasting color, (3) restricting access to the test control area, and (4) informing personnel in the facility (other than test personnel) of test activities. It is concluded that the basic facility is satisfactory for conducting long-duration manned tests, and it is recommended that all monitor and alarm functions be integrated into a single operation.

The quest for better quality-of-life - learning from large-scale shaking table tests

NASA Astrophysics Data System (ADS)

Nakashima, M.; Sato, E.; Nagae, T.; Kunio, F.; Takahito, I.

2010-12-01

Earthquake engineering has its origins in the practice of “learning from actual earthquakes and earthquake damages.” That is, we recognize serious problems by witnessing the actual damage to our structures, and then we develop and apply engineering solutions to solve these problems. This tradition in earthquake engineering, i.e., “learning from actual damage,” was an obvious engineering response to earthquakes and arose naturally as a practice in a civil and building engineering discipline that traditionally places more emphasis on experience than do other engineering disciplines. But with the rapid progress of urbanization, as society becomes denser, and as the many components that form our society interact with increasing complexity, the potential damage with which earthquakes threaten the society also increases. In such an era, the approach of ”learning from actual earthquake damages” becomes unacceptably dangerous and expensive. Among the practical alternatives to the old practice is to “learn from quasi-actual earthquake damages.” One tool for experiencing earthquake damages without attendant catastrophe is the large shaking table. E-Defense, the largest one we have, was developed in Japan after the 1995 Hyogoken-Nanbu (Kobe) earthquake. Since its inauguration in 2005, E-Defense has conducted over forty full-scale or large-scale shaking table tests, applied to a variety of structural systems. The tests supply detailed data on actual behavior and collapse of the tested structures, offering the earthquake engineering community opportunities to experience and assess the actual seismic performance of the structures, and to help society prepare for earthquakes. Notably, the data were obtained without having to wait for the aftermaths of actual earthquakes. Earthquake engineering has always been about life safety, but in recent years maintaining the quality of life has also become a critical issue. Quality-of-life concerns include nonstructural

Extended Life Coolant Testing

DTIC Science & Technology

2016-06-06

between the corrosive water and the grease that was leaked into the system. In terms of corrosion, the third test still passed by not exceeding any of...length. While the results of testing showed little corrosion, some negative interactions with the corrosive water mixture were observed. 15...such as temperature, flow rate, or corrosive water concentration might have a larger impact on performance. UNCLASSIFIED UNCLASSIFIED vi

Life Assessment for Cr-Mo Steel Dissimilar Joints by Various Filler Metals Using Accelerated Creep Testing

NASA Astrophysics Data System (ADS)

Petchsang, S.; Phung-on, I.; Poopat, B.

2016-12-01

Accelerated creep rupture tests were performed on T22/T91 dissimilar metal joints to determine the fracture location and rupture time of different weldments. Four configurations of deposited filler metal were tested using gas tungsten arc welding to estimate the service life for Cr-Mo steel dissimilar joints at elevated temperatures in power plants. Results indicated that failure in all configurations occurred in the tempered original microstructure and tempered austenite transformation products (martensite or bainite structure) as type IV cracking at the intercritical area of the heat-affected zone (ICHAZ) for both T22 and T91 sides rather than as a consequence of the different filler metals. Creep damage occurred with the formation of precipitations and microvoids. The correlation between applied stress and the Larson-Miller parameter (PLM) was determined to predict the service life of each material configuration. Calculated time-to-failure based on the PLM and test results for both temperature and applied stress parameters gave a reasonable fit. The dissimilar joints exhibited lower creep rupture compared to the base material indicating creep degradation of the weldment.

Results of deep DoD life cycle tests at high rates on 12Ah NiCd cells

NASA Technical Reports Server (NTRS)

Panneton, Paul E.; Meyer, John R.

1992-01-01

A 12 Ah Nickel-Cadmium (NiCd) Low Earth Orbit (LEO) life cycle test that induced 47 percent more deep Depth Of Discharge cycles by mixing them with shallow DOD cycles is discussed. The test showed how aggressive recharging to a C/D ratio of 1.15 nearly doubled performance over cycling below a C/D of 1.11.

Preliminary results of the mission profile life test of a 30 cm Hg bombardment thruster

NASA Technical Reports Server (NTRS)

Bechtel, R. T.; James, E. L.

1979-01-01

Long term tests were performed on a 30 cm Hg bombardment thruster and a power processing unit to determine lifetime characteristics. The thruster performance data and other operational characteristics taken at various times during the test segment are presented and evaluated with the life limiting mechanisms: discharge chamber erosion, deposition and spalling, external erosion, cathode degradation, and propellant isolator leakage. The control algorithms for thruster start up, steady state operation, throttle, detection and correction of off normal conditions, and shutdown are discussed.

Adjusting for cross-cultural differences in computer-adaptive tests of quality of life.

PubMed

Gibbons, C J; Skevington, S M

2018-04-01

Previous studies using the WHOQOL measures have demonstrated that the relationship between individual items and the underlying quality of life (QoL) construct may differ between cultures. If unaccounted for, these differing relationships can lead to measurement bias which, in turn, can undermine the reliability of results. We used item response theory (IRT) to assess differential item functioning (DIF) in WHOQOL data from diverse language versions collected in UK, Zimbabwe, Russia, and India (total N = 1332). Data were fitted to the partial credit 'Rasch' model. We used four item banks previously derived from the WHOQOL-100 measure, which provided excellent measurement for physical, psychological, social, and environmental quality of life domains (40 items overall). Cross-cultural differential item functioning was assessed using analysis of variance for item residuals and post hoc Tukey tests. Simulated computer-adaptive tests (CATs) were conducted to assess the efficiency and precision of the four items banks. Splitting item parameters by DIF results in four linked item banks without DIF or other breaches of IRT model assumptions. Simulated CATs were more precise and efficient than longer paper-based alternatives. Assessing differential item functioning using item response theory can identify measurement invariance between cultures which, if uncontrolled, may undermine accurate comparisons in computer-adaptive testing assessments of QoL. We demonstrate how compensating for DIF using item anchoring allowed data from all four countries to be compared on a common metric, thus facilitating assessments which were both sensitive to cultural nuance and comparable between countries.

Reproducibility and responsiveness of quality of life assessment and six minute walk test in elderly heart failure patients.

PubMed

O'Keeffe, S T; Lye, M; Donnellan, C; Carmichael, D N

1998-10-01

To examine the reproducibility and responsiveness to change of a six minute walk test and a quality of life measure in elderly patients with heart failure. Longitudinal within patient study. 60 patients with heart failure (mean age 82 years) attending a geriatric outpatient clinic, 45 of whom underwent a repeat assessment three to eight weeks later. Subjects underwent a standardised six minute walk test and completed the chronic heart failure questionnaire (CHQ), a heart failure specific quality of life questionnaire. Intraclass correlation coefficients (ICC) were calculated using a random effects one way analysis of variance as a measure of reproducibility. Guyatt's responsiveness coefficient and effect sizes were calculated as measures of responsiveness to change. 24 patients reported no major change in cardiac status, while seven had deteriorated and 14 had improved between the two clinic visits. Reproducibility was satisfactory (ICC > 0.75) for the six minute walk test, for the total CHQ score, and for the dyspnoea, fatigue, and emotion domains of the CHQ. Effect sizes for all measures were large (> 0.8), and responsiveness coefficients were very satisfactory (> 0.7). Effect sizes for detecting deterioration were greater than those for detecting improvement. Quality of life assessment and a six minute walk test are reproducible and responsive measures of cardiac status in frail, very elderly patients with heart failure.

New Rock Abrasivity Test Method for Tool Life Assessments on Hard Rock Tunnel Boring: The Rolling Indentation Abrasion Test (RIAT)

NASA Astrophysics Data System (ADS)

Macias, F. J.; Dahl, F.; Bruland, A.

2016-05-01

The tunnel boring machine (TBM) method has become widely used and is currently an important presence within the tunnelling industry. Large investments and high geological risk are involved using TBMs, and disc cutter consumption has a great influence on performance and cost, especially in hard rock conditions. Furthermore, reliable cutter life assessments facilitate the control of risk as well as avoiding delays and budget overruns. Since abrasive wear is the most common process affecting cutter consumption, good laboratory tests for rock abrasivity assessments are needed. A new abrasivity test method by rolling disc named Rolling Indentation Abrasion Test (RIAT) has been developed. The goal of the new test design and procedure is to reproduce wear behaviour on hard rock tunnel boring in a more realistic way than the traditionally used methods. Wear by rolling contact on intact rock samples is introduced and several rock types, covering a wide rock abrasiveness range, have been tested by RIAT. The RIAT procedure indicates a great ability of the testing method to assess abrasive wear on rolling discs. In addition and to evaluate the newly developed RIAT test method, a comprehensive laboratory testing programme including the most commonly used abrasivity test methods and the mineral composition were carried out. Relationships between the achieved results from conventional testing and RIAT results have been analysed.

The MELISSA pilot plant facility as as integration test-bed for advanced life support systems

NASA Technical Reports Server (NTRS)

Godia, F.; Albiol, J.; Perez, J.; Creus, N.; Cabello, F.; Montras, A.; Masot, A.; Lasseur, Ch

2004-01-01

The different advances in the Micro Ecological Life Support System Alternative project (MELISSA), fostered and coordinated by the European Space Agency, as well as in other associated technologies, are integrated and demonstrated in the MELISSA Pilot Plant laboratory. During the first period of operation, the definition of the different compartments at an individual basis has been achieved, and the complete facility is being re-designed to face a new period of integration of all these compartments. The final objective is to demonstrate the potentiality of biological systems such as MELISSA as life support systems. The facility will also serve as a test bed to study the robustness and stability of the continuous operation of a complex biological system. This includes testing of the associated instrumentation and control for a safe operation, characterization of the chemical and microbial safety of the system, as well as tracking the genetic stability of the microbial strains used. The new period is envisaged as a contribution to the further development of more complete biological life support systems for long-term manned missions, that should be better defined from the knowledge to be gained from this integration phase. This contribution summarizes the current status of the Pilot Plant and the planned steps for the new period. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

Role of test motivation in intelligence testing.

PubMed

Duckworth, Angela Lee; Quinn, Patrick D; Lynam, Donald R; Loeber, Rolf; Stouthamer-Loeber, Magda

2011-05-10

Intelligence tests are widely assumed to measure maximal intellectual performance, and predictive associations between intelligence quotient (IQ) scores and later-life outcomes are typically interpreted as unbiased estimates of the effect of intellectual ability on academic, professional, and social life outcomes. The current investigation critically examines these assumptions and finds evidence against both. First, we examined whether motivation is less than maximal on intelligence tests administered in the context of low-stakes research situations. Specifically, we completed a meta-analysis of random-assignment experiments testing the effects of material incentives on intelligence-test performance on a collective 2,008 participants. Incentives increased IQ scores by an average of 0.64 SD, with larger effects for individuals with lower baseline IQ scores. Second, we tested whether individual differences in motivation during IQ testing can spuriously inflate the predictive validity of intelligence for life outcomes. Trained observers rated test motivation among 251 adolescent boys completing intelligence tests using a 15-min "thin-slice" video sample. IQ score predicted life outcomes, including academic performance in adolescence and criminal convictions, employment, and years of education in early adulthood. After adjusting for the influence of test motivation, however, the predictive validity of intelligence for life outcomes was significantly diminished, particularly for nonacademic outcomes. Collectively, our findings suggest that, under low-stakes research conditions, some individuals try harder than others, and, in this context, test motivation can act as a third-variable confound that inflates estimates of the predictive validity of intelligence for life outcomes.

Role of test motivation in intelligence testing

PubMed Central

Duckworth, Angela Lee; Quinn, Patrick D.; Lynam, Donald R.; Loeber, Rolf; Stouthamer-Loeber, Magda

2011-01-01

Intelligence tests are widely assumed to measure maximal intellectual performance, and predictive associations between intelligence quotient (IQ) scores and later-life outcomes are typically interpreted as unbiased estimates of the effect of intellectual ability on academic, professional, and social life outcomes. The current investigation critically examines these assumptions and finds evidence against both. First, we examined whether motivation is less than maximal on intelligence tests administered in the context of low-stakes research situations. Specifically, we completed a meta-analysis of random-assignment experiments testing the effects of material incentives on intelligence-test performance on a collective 2,008 participants. Incentives increased IQ scores by an average of 0.64 SD, with larger effects for individuals with lower baseline IQ scores. Second, we tested whether individual differences in motivation during IQ testing can spuriously inflate the predictive validity of intelligence for life outcomes. Trained observers rated test motivation among 251 adolescent boys completing intelligence tests using a 15-min “thin-slice” video sample. IQ score predicted life outcomes, including academic performance in adolescence and criminal convictions, employment, and years of education in early adulthood. After adjusting for the influence of test motivation, however, the predictive validity of intelligence for life outcomes was significantly diminished, particularly for nonacademic outcomes. Collectively, our findings suggest that, under low-stakes research conditions, some individuals try harder than others, and, in this context, test motivation can act as a third-variable confound that inflates estimates of the predictive validity of intelligence for life outcomes. PMID:21518867

Italian validation of the Purpose In Life (PIL) test and the Seeking Of Noetic Goals (SONG) test in a population of cancer patients.

PubMed

Brunelli, C; Bianchi, E; Murru, L; Monformoso, P; Bosisio, M; Gangeri, L; Miccinesi, G; Scrignaro, M; Ripamonti, C; Borreani, C

2012-11-01

The first instruments developed to evaluate specific logotherapeutic dimensions were the Purpose In Life (PIL) and the Seeking Of Noetic Goals (SONG) tests, designed to reflect Frankl's concepts of, respectively, meaning in life attainment and will to meaning. This study aims to perform the Italian cultural adaptation and the psychometric validation of the PIL and SONG questionnaires. We administered the PIL and SONG, culturally adapted into the Italian language, to 266 cancer patients. The psychometric validation appraised construct validity, internal consistency, test-retest reliability, known-group validity, and convergent validity of the two questionnaires with respect to one another. The factorial analysis indicates that the original single-factor solution can be maintained for both instruments (proportion of variance explained by the first factor 77% and 71% for the PIL and SONG, respectively). The results show excellent internal consistency (Cronbach's alpha of 0.91 for the PIL and 0.90 for the SONG) and test-retest reliability (intraclass correlation coefficient of 0.92 for the PIL and 0.81 for the SONG). As expected, males, believers, patients nearer to the diagnosis, and patients not undergoing psychological therapy have higher PIL and lower SONG scores, while expectations for age were not confirmed. The average level for the PIL was 107.3, while for the SONG, it was 66.1, and a negative correlation (-0.47) between PIL and SONG scores indicates good convergent validity of the two instruments. Italian versions of the PIL and SONG are adequate and reliable self-report instruments for evaluating purpose in life and the motivation to find purpose for cancer patient populations.

Draft Test Guideline: Fish Early-Life Stage Toxicity Test

EPA Pesticide Factsheets

The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

Space Station Freedom environmental control and life support system phase 3 simplified integrated test detailed report

NASA Technical Reports Server (NTRS)

Roberts, B. C.; Carrasquillo, R. L.; Dubiel, M. Y.; Ogle, K. Y.; Perry, J. L.; Whitley, K. M.

1990-01-01

A description of the phase 3 simplified integrated test (SIT) conducted at the Marshall Space Flight Center (MSFC) Core Module Integration Facility (CMIF) in 1989 is presented. This was the first test in the phase 3 series integrated environmental control and life support systems (ECLSS) tests. The basic goal of the SIT was to achieve full integration of the baseline air revitalization (AR) subsystems for Space Station Freedom. Included is a description of the SIT configuration, a performance analysis of each subsystem, results from air and water sampling, and a discussion of lessons learned from the test. Also included is a full description of the preprototype ECLSS hardware used in the test.

Life test results of OLED-XL long-life devices for use in active matrix organic light emitting diode (AMOLED) displays for head mounted applications

NASA Astrophysics Data System (ADS)

Fellowes, David A.; Wood, Michael V.; Hastings, Arthur R., Jr.; Ghosh, Amalkumar P.; Prache, Olivier

2007-04-01

eMagin Corporation has recently developed long-life OLED-XL devices for use in their AMOLED microdisplays for head-worn applications. AMOLED displays have been known to exhibit high levels of performance with regards to contrast, response time, uniformity, and viewing angle, but a lifetime improvement has been perceived to be essential for broadening the applications of OLED's in the military and in the commercial market. The new OLED-XL devices gave the promise of improvements in usable lifetime over 6X what the standard full color, white, and green devices could provide. The US Army's RDECOM CERDEC NVESD performed life tests on several standard and OLED-XL panels from eMagin under a Cooperative Research and Development Agreement (CRADA). Displays were tested at room temperature, utilizing eMagin's Design Reference Kit driver, allowing computer controlled optimization, brightness adjustment, and manual temperature compensation. The OLED Usable Lifetime Model, developed under a previous NVESD/eMagin SPIE paper presented at DSS 2005, has been adjusted based on the findings of these tests. The result is a better understanding of the applicability of AMOLEDs in military and commercial head mounted systems: where good fits are made, and where further development might be needed.

Predicting the Job and Life Satisfaction of Italian Teachers: Test of a Social Cognitive Model

ERIC Educational Resources Information Center

Lent, Robert W.; Nota, Laura; Soresi, Salvatore; Ginevra, Maria C.; Duffy, Ryan D.; Brown, Steven D.

2011-01-01

This study tested a social cognitive model of work and life satisfaction (Lent & Brown, 2006, 2008) in a sample of 235 Italian school teachers. The model offered good overall fit to the data, though not all individual path coefficients were significant. Three of five predictors (favorable work conditions, efficacy-relevant supports, and…

An evaluation of fish early life stage tests for predicting reproductive and longer-term toxicity from plant protection product active substances.

PubMed

Wheeler, James R; Maynard, Samuel K; Crane, Mark

2014-08-01

The chronic toxicity of chemicals to fish is routinely assessed by using fish early life stage (ELS) test results. Fish full life cycle (FLC) tests are generally required only when toxicity, bioaccumulation, and persistence triggers are met or when there is a suspicion of potential endocrine-disrupting properties. This regulatory approach is based on a relationship between the results of fish ELS and FLC studies first established more than 35 yrs ago. Recently, this relationship has been challenged by some regulatory authorities, and it has been recommended that more substances should undergo FLC testing. In addition, a project proposal has been submitted to the Organisation for Economic Cooperation and Development (OECD) to develop a fish partial life cycle (PLC) test including a reproductive assessment. Both FLC and PLC tests are animal- and resource-intensive and technically challenging and should therefore be undertaken only if there is clear evidence that they are necessary for coming to a regulatory decision. The present study reports on an analysis of a database of paired fish ELS and FLC endpoints for plant protection product active substances from European Union draft assessment reports and the US Environmental Protection Agency Office of Pesticide Programs Pesticide Ecotoxicity Database. Analysis of this database shows a clear relationship between ELS and FLC responses, with similar median sensitivity across substances when no-observed-effect concentrations (NOECs) are compared. There was also no indication that classification of a substance as a mammalian reproductive toxicant leads to more sensitive effects in fish FLC tests than in ELS tests. Indeed, the response of the ELS tests was generally more sensitive than the most sensitive reproduction NOEC from a FLC test. This analysis indicates that current testing strategies and guidelines are fit for purpose and that there is no need for fish full or partial life cycle tests for most plant protection

Development and testing of a high cycle life 30 A-h sealed AgO-Zn battery

NASA Technical Reports Server (NTRS)

Bogner, R. S.

1972-01-01

A two-phase program was initiated to investigate design parameters and technology to develop an improved AgO-Zn battery. The basic performance goal was 100 charge/discharge cycles (22 h/2 h) at 50 percent depth of discharge following a six-month period of charged stand at room temperature. Phase 1, cell evaluation, involved testing 70 cells in five-cell groups. The major design variables were active material ratios, electrolyte concentrations, separator systems, and negative plate shape. Phase 1 testing showed that cycle life could be improved 10 percent to 20 percent by using greater ratios of zinc to silver oxide and higher electrolyte concentrations. Wedge-shaped negatives increased cycle life by nearly 100 percent. Phase 2 battery evaluation, which was initiated before the Phase 1 results were known completely, involved evaluation of six designs as 19-cell batteries. Only one battery exceeded 100 cycles following nine months charged stand.

Strainrange partitioning life predictions of the long time metal properties council creep-fatigue tests

NASA Technical Reports Server (NTRS)

Saltsman, J. F.; Halford, G. R.

1979-01-01

The method of strainrange partitioning is used to predict the cyclic lives of the Metal Properties Council's long time creep-fatigue interspersion tests of several steel alloys. Comparisons are made with predictions based upon the time- and cycle-fraction approach. The method of strainrange partitioning is shown to give consistently more accurate predictions of cyclic life than is given by the time- and cycle-fraction approach.

Hybrid Modeling for Testing Intelligent Software for Lunar-Mars Closed Life Support

NASA Technical Reports Server (NTRS)

Malin, Jane T.; Nicholson, Leonard S. (Technical Monitor)

1999-01-01

Intelligent software is being developed for closed life support systems with biological components, for human exploration of the Moon and Mars. The intelligent software functions include planning/scheduling, reactive discrete control and sequencing, management of continuous control, and fault detection, diagnosis, and management of failures and errors. Four types of modeling information have been essential to system modeling and simulation to develop and test the software and to provide operational model-based what-if analyses: discrete component operational and failure modes; continuous dynamic performance within component modes, modeled qualitatively or quantitatively; configuration of flows and power among components in the system; and operations activities and scenarios. CONFIG, a multi-purpose discrete event simulation tool that integrates all four types of models for use throughout the engineering and operations life cycle, has been used to model components and systems involved in the production and transfer of oxygen and carbon dioxide in a plant-growth chamber and between that chamber and a habitation chamber with physicochemical systems for gas processing.

Bioregenerative Life Support Systems Test Complex (Bio-Plex) Food Processing System: A Dual System

NASA Technical Reports Server (NTRS)

Perchonok, Michele; Vittadini, Elena; Peterson, Laurie J.; Swango, Beverly E.; Toerne, Mary E.; Russo, Dane M. (Technical Monitor)

2001-01-01

A Bioregenerative Life Support Test Complex, BIO-Plex, is currently being constructed at the Johnson Space Center (JSC) in Houston, TX. This facility will attempt to answer the questions involved in developing a lunar or planetary base. The Food Processing System (FPS) of the BIO-Plex is responsible for supplying food to the crew in coordination with the chosen mission scenario. Long duration space missions require development of both a Transit Food System and of a Lunar or Planetary Food System. These two systems are intrinsically different since the first one will be utilized in the transit vehicle in microgravity conditions with mostly resupplied foods, while the second will be used in conditions of partial gravity (hypogravity) to process foods from crops grown in the facility. The Transit Food System will consist of prepackaged food of extended shelf life. It will be supplemented with salad crops that will be consumed fresh. Microgravity imposes significant limitation on the ability to handle food and allows only for minimal processing. The challenge is to develop food systems similar to the International Space Station or Shuttle Food Systems but with a shelf life of 3 - 5 years. The Lunar or Planetary Food System will allow for food processing of crops due to the presence of some gravitational force (1/6 to 1/3 that of Earth). Crops such as wheat, soybean, rice, potato, peanut, and salad crops, will be processed to final products to provide a nutritious and acceptable diet for the crew. Not only are constraints imposed on the FPS from the crops (e.g., crop variation, availability, storage and shelf-life) but also significant requirements are present for the crew meals (e.g., RDA, high quality, safety, variety). The FPS becomes a fulcrum creating the right connection from crops to crew meals while dealing with issues of integration within a closed self-regenerative system (e.g., safe processing, waste production, volumes, air contaminations, water usage, etc

Testing healthy immigrant effects among late life immigrants in the United States: using multiple indicators.

PubMed

Choi, Sunha H

2012-04-01

This study tested a healthy immigrant effect (HIE) and postimmigration health status changes among late life immigrants. Using three waves of the Second Longitudinal Study of Aging (1994-2000) and the linked mortality file through 2006, this study compared (a) chronic health conditions, (b) longitudinal trajectories of self-rated health, (c) longitudinal trajectories of functional impairments, and (d) mortality between three groups (age 70+): (i) late life immigrants with less than 15 years in the United States (n = 133), (ii) longer term immigrants (n = 672), and (iii) U.S.-born individuals (n = 8,642). Logistic and Poisson regression, hierarchical generalized linear modeling, and survival analyses were conducted. Late life immigrants were less likely to suffer from cancer, had lower numbers of chronic conditions at baseline, and displayed lower hazards of mortality during the 12-year follow-up. However, their self-rated health and functional status were worse than those of their counterparts over time. A HIE was only partially supported among older adults.

Life Testing of Yb14MnSb11 for High Performance Thermoelectric Couples

NASA Technical Reports Server (NTRS)

Paik, Jong-Ah; Brandon, Erik; Caillat, Thierry; Ewell, Richard; Fleurial, Jean-Pierre

2011-01-01

The goal of this study is to verify the long term stability of Yb14MnSb11 for high performance thermoelectric (TE) couples. Three main requirements need to be satisfied to ensure the long term stability of thermoelectric couples: 1) stable thermoelectric properties, 2) stable bonding interfaces, and 3) adequate sublimation suppression. The efficiency of the couple is primarily based on the thermoelectric properties of the materials selected for the couple. Therefore, these TE properties should exhibit minimal degradation during the operating period of the thermoelectric couples. The stability of the bonding is quantified by low contact resistances of the couple interfaces. In order to ensure high efficiency, the contact resistances of the bonding interfaces should be negligible. Sublimation suppression is important because the majority of thermoelectric materials used for power generation have peak figures of merit at temperatures where sublimation rates are high. Controlling sublimation is also essential to preserve the efficiency of the couple. During the course of this research, three different life tests were performed with Yb14MnSb11 coupons. TE properties of Yb14MnSb11 exhibited no degradation after 6 months of aging at 1273K, and the electrical contact resistance between a thin metallization layer and the Yb14MnSb11 remained negligible after 1500hr aging at 1273K. A sublimation suppression layer for Yb14MnSb11 was developed and demonstrated for more than 18 months with coupon testing at 1273K. These life test data indicate that thermoelectric elements based on Yb14MnSb11 are a promising technology for use in future high performance thermoelectric power generating couples.

Gas spark switches with increased operating life for Marx generator of lightning test complex

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

Bykov, Yu. A.; Krastelev, E. G., E-mail: ekrastelev@yandex.ru

A new design of gas spark switches with an increased operating life and stable dynamic characteristics for the Marx generator of the lightning test complex has been developed. The switches are characterized by the following parameters in the mode of operation: voltage up to 80 kV, discharge current up to 50 kA, flowing charge up to 3.5 C/pulse. An increased operating life is achieved by using torus-shaped electrodes with increased working surface area and a trigger electrode in the form of a thick disk with a hole located between them. Low breakdown delay time and high stability of breakdown voltagemore » under dynamic conditions are provided by gas preionization in the spark gap using UV radiation of an additional corona discharge in the axial region.« less

Assessment of health risks resulting from early-life exposures: Are current chemical toxicity testing protocols and risk assessment methods adequate?

PubMed

Felter, Susan P; Daston, George P; Euling, Susan Y; Piersma, Aldert H; Tassinari, Melissa S

2015-03-01

Abstract Over the last couple of decades, the awareness of the potential health impacts associated with early-life exposures has increased. Global regulatory approaches to chemical risk assessment are intended to be protective for the diverse human population including all life stages. However, questions persist as to whether the current testing approaches and risk assessment methodologies are adequately protective for infants and children. Here, we review physiological and developmental differences that may result in differential sensitivity associated with early-life exposures. It is clear that sensitivity to chemical exposures during early-life can be similar, higher, or lower than that of adults, and can change quickly within a short developmental timeframe. Moreover, age-related exposure differences provide an important consideration for overall susceptibility. Differential sensitivity associated with a life stage can reflect the toxicokinetic handling of a xenobiotic exposure, the toxicodynamic response, or both. Each of these is illustrated with chemical-specific examples. The adequacy of current testing protocols, proposed new tools, and risk assessment methods for systemic noncancer endpoints are reviewed in light of the potential for differential risk to infants and young children.

Psychometric testing of the Caregiver Quality of Life Index-Cancer scale in an Iranian sample of family caregivers to newly diagnosed breast cancer women.

PubMed

Khanjari, Sedigheh; Oskouie, Fatemeh; Langius-Eklöf, Ann

2012-02-01

To translate and test the reliability and validity of the Persian version of the Caregiver Quality of Life Index-Cancer scale. Research across many countries has determined quality of life of cancer patients, but few attempts have been made to measure the quality of life of family caregivers of patients with breast cancer. The Caregiver Quality of Life Index-Cancer scale was developed for this purpose, but until now, it has not been translated into or tested in the Persian language. Methodological research design. After standard translation, the 35-item Caregiver Quality of Life Index-Cancer scale was administered to 166 Iranian family caregivers of patients with breast cancer. A confirmatory factor analysis was carried out using LISREL to test the scale's construct validity. Further, the internal consistency and convergent validity of the instrument were tested. For convergent validity, four instruments were used in the study: sense of coherence scale, spirituality perspective scale, health index and brief religious coping scale. The confirmatory factor analysis resulted in the same four-factor structure as the original, though, with somewhat different item loadings. The Persian version of the Caregiver Quality of Life Index-Cancer scales had satisfactory internal consistency (0·72-0·90). Tests of convergent validity showed that all hypotheses were confirmed. A hierarchical multiple regression analysis additionally confirmed the convergent validity between the total Caregiver Quality of Life Index-Cancer score and sense of coherence (β = 0·34), negative religious coping (β = -0·21), education (β = 0·24) and the more severe stage of breast cancer (β = 0·23), in total explaining 41% of the variance. The Persian version of the Caregiver Quality of Life Index-Cancer scale could be a reliable and valid measure in Iranian family caregivers of patients with breast cancer. The Persian version of the Caregiver Quality of Life Index-Cancer scale is simple to

Testing the cumulative stress and mismatch hypotheses of psychopathology in a rat model of early-life adversity.

PubMed

Daskalakis, Nikolaos P; Oitzl, Melly S; Schächinger, Hartmut; Champagne, Danielle L; de Kloet, E Ronald

2012-07-16

In the present study, we tested both the cumulative stress and the mismatch hypothesis of psychopathology. For this purpose the combined effects of early-life adversity and later-life stress exposure on behavioral markers of psychosis susceptibility were studied in male Wistar rats. Experiment I: rat pups divided on the basis of the levels of their maternal care experience in low, medium or high maternal care groups, were reared post-weaning in groups (Exp. IA) or in social isolation (Exp. IB) and tested at adulthood under basal conditions or after an acute corticosterone (CORT) administration. Maternal care levels were assessed by measuring the dam's licking and grooming (LG) the first postnatal week of life. Experiment II: rat pups exposed as neonates to daily sessions of 8h of maternal separation (MS) on postnatal days 3, 4 and 5 either altogether in their home cage (HOME SEP) or alone in a novel environment (NOVEL SEP), were reared post-weaning in groups and tested at adulthood under basal conditions. Adult testing included behaviors marking psychosis susceptibility: apomorphine-induced gnawing (APO-gnawing), acoustic startle response and its modulation by a prepulse stimulus (PPI). The behavior of the Medium LG offspring was used as baseline reference for all the three experiments. Experiment I: Low maternal LG history alone had limited effects on the behavior of Wistar offspring, although increased acoustic startle and increased PPI, at high prepulse intensity levels, were observed. When low maternal LG history was combined with post-weaning social isolation, basal APO-gnawing was decreased and PPI increased, compared to High LG and Med LG offspring. This reflects attenuated psychosis susceptibility. High LG offspring reared in isolation displayed, however, the highest APO-gnawing and the lowest PPI levels among rats reared in social isolation, which is indicative for increased psychosis susceptibility. These findings support the mismatch hypothesis. For

Perceived discrimination and health-related quality of life: testing the Reserve Capacity Model in Hispanic Americans.

PubMed

Howarter, Alisha D; Bennett, Kymberley K

2013-01-01

This study tested aspects of the Reserve Capacity Model (Gallo & Matthews, 2003; Gallo, Penedo Espinosa de los Monteros, & Arguelles, 2009) as a means of understanding disparities in health-related quality of life appraisals among Hispanic Americans. Questionnaire data were collected from 236 Hispanic participants, including measures of perceived discrimination, optimism, social support, symptoms of trait anxiety, and physical and mental health-related quality of life. Path analysis indicated direct, negative associations between perceived discrimination and both forms of health-related quality of life. Results also showed that these relationships were partially mediated by the reserve capacity variable of optimism and by symptoms of anxiety, though evidence for mediation by anxiety was stronger than for optimism. Findings suggest that perceived discrimination depletes intrapersonal reserves in Hispanic Americans, which, in turn, induces negative emotions. Implications for community-level interventions are discussed.

Operational Phase Life Cycle Assessment of Select NASA Ground Test Facilities

NASA Technical Reports Server (NTRS)

Sydnor, George H.; Marshall, Timothy J.; McGinnis, Sean

2011-01-01

NASA's Aeronautics Test Program (ATP) is responsible for many large, high-energy ground test facilities that accomplish the nation s most advanced aerospace research. In order to accomplish these national objectives, significant energy and resources are consumed. A select group of facilities was analyzed using life-cycle assessment (LCA) to determine carbon footprint and environmental impacts. Most of these impacts stem from electricity and natural gas consumption, used directly at the facility and to generate support processes such as compressed air and steam. Other activities were analyzed but determined to be smaller in scale and frequency with relatively negligible environmental impacts. More specialized facilities use R-134a, R-14, jet fuels, or nitrogen gas, and these unique inputs can have a considerable effect on a facility s overall environmental impact. The results of this LCA will be useful to ATP and NASA as the nation looks to identify its top energy consumers and NASA looks to maximize research output and minimize environmental impact. Keywords: NASA, Aeronautics, Wind tunnel, Keyword 4, Keyword 5

Life-finding detector development at NASA GSFC using a custom H4RG test bed

NASA Astrophysics Data System (ADS)

Mosby, Gregory; Rauscher, Bernard; Kutyrev, Alexander

2018-01-01

Chemical species associated with life, called biosignatures, should be visible in exoplanet atmospheres with larger space telescopes. These signals will be faint and require very low noise (~e-) detectors to robustly measure. At NASA Goddard we are developing a single detector H4RG test bed to characterize and identify potential technology developments needed for the next generation's large space telescopes. The vacuum and cryogenic test bed will include near infrared light sources from integrating spheres using a motorized shutter. The detector control and readout will be handled by a Leach controller. Detector cables have been manufactured and test planning has begun. Planned tests include testing minimum read noise capabilities, persistence mitigation strategies using long wavelength light, and measuring intrapixel variation which might affect science goals of future missions. In addition to providing a means to identify areas of improvement in detector technology, we hope to use this test bed to probe some fundamental physics of these infrared arrays.

End-of-life healthcare expenditure: Testing economic explanations using a discrete choice experiment.

PubMed

Fischer, Barbara; Telser, Harry; Zweifel, Peter

2018-06-07

Healthcare expenditure (HCE) spent during an individual's last year of life accounts for a high share of lifetime HCE. This finding is puzzling because an investment in health is unlikely to have a sufficiently long payback period. However, Becker et al. (2007) and Philipson et al. (2010) have advanced a theory designed to explain high willingness to pay (WTP) for an extension of life close to its end. Their testable implications are complemented by the concept of 'pain of risk bearing' introduced by Eeckhoudt and Schlesinger (2006). They are tested using a discrete choice experiment performed in 2014, involving 1,529 Swiss adults. An individual setting where the price attribute is substantial out-of-pocket payment for a novel drug for treatment of terminal cancer is distinguished from a societal one, where it is an increase in contributions to social health insurance. Most of the economic predictions receive empirical support. Copyright © 2018. Published by Elsevier B.V.

Assessing variability in chemical acute toxicity of unionid mussels: Influence of intra- and inter-laboratory testing, life stage, and species

USGS Publications Warehouse

Raimondo, Sandy; Lilavois, Crystal R.; Lee, Larisa; Augspurger, Tom; Wang, Ning; Ingersoll, Christopher G.; Bauer, Candice R.; Hammer, Edward J.; Barron, Mace G.

2016-01-01

We developed a toxicity database for unionid mussels to examine the extent of intra- and inter-laboratory variability in acute toxicity tests with mussel larvae (glochidia) and juveniles; the extent of differential sensitivity of the two life stages; and the variation in sensitivity among commonly tested mussels (Lampsilis siliquoidea, Utterbackia imbecillis, Villosa iris), commonly tested cladocerans (Daphnia magna, Ceriodaphnia dubia) and fish (Oncorhynchus mykiss, Pimephales promelas, Lepomis macrochirus). The results of these analyses indicate intra-laboratory variability for median effect concentrations (EC50) averaged about 2 fold for both life stages, while inter-laboratory variability averaged 3.6 fold for juvenile mussels and 6.3 fold for glochidia. The EC50s for juveniles and glochidia were within a factor of 2 of each other for 50% of paired records across chemicals, with juveniles more sensitive than glochidia by more than 2 fold for 33% of the comparisons made between life stages. There was a high concurrence of the sensitivity of commonly tested L. siliquoidea, U. imbecillis, and V. iris to that of other mussels. However, this concurrence decreases as the taxonomic distance of the commonly tested cladocerans and fish to mussels increases. The compiled mussel database and determination of data variability will advance risk assessments by including more robust species sensitivity distributions, interspecies correlation estimates, and availability of taxon-specific empirically derived application factors for risk assessment.

Life Testing of the Vapor Compression Distillation Urine Processing Assembly (VCD/UPA) at the Marshall Space Flight Center

NASA Technical Reports Server (NTRS)

Wieland, Paul O.

1998-01-01

Wastewater and urine generated on the International Space Station will be processed to recover pure water. The method selected is vapor compression distillation (VCD). To verify the long-term reliability and performance of the VCD Urine Processing Assembly (UPA), accelerated life testing was performed at the Marshall Space Flight Center (MSFC) from January 1993 to April 1996. Two UPAS, the VCD-5 and VCD-5A, were tested for 204 days and 665 days, respectively. The compressor gears and the distillation centrifuge drive belt were found to have an operating life of approximately 4800 hours. Precise alignment of the flex-spline of the fluids pump is essential to avoid failure of the pump after about 400 hours of operation. Also, leakage around the seals of the drive shaft of the fluids pump and purge pump must be eliminated for continued good performance. Results indicate that, with some design and procedural modifications and suitable quality control, the required performance and operational life can be met with the VCD/UPA.

Assessment of a condition-specific quality-of-life measure for patients with developmentally absent teeth: validity and reliability testing.

PubMed

Akram, A J; Ireland, A J; Postlethwaite, K C; Sandy, J R; Jerreat, A S

2013-11-01

This article describes the process of validity and reliability testing of a condition-specific quality-of-life measure for patients with hypodontia presenting for orthodontic treatment. The development of the instrument is described in a previous article. Royal Devon and Exeter NHS Foundation Trust & Musgrove Park Hospital, Taunton. The child perception questionnaire was used as a standard against which to test criterion validity. The Bland and Altman method was used to check agreement between the two questionnaires. Construct validity was tested using principal component analysis on the four sections of the questionnaire. Test-retest reliability was tested using intraclass correlation coefficient and Bland and Altman method. Cronbach's alpha was used to test internal consistency reliability. Overall the questionnaire showed good reliability, criterion and construct validity. This together with previous evidence of good face and content validity suggests that the instrument may prove useful in clinical practice and further research. This study has demonstrated that the newly developed condition-specific quality-of-life questionnaire is both valid and reliable for use in young patients with hypodontia. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

Development of a Methodology for Successful Multigeneration Life-Cycle Testing of the Estuarine Sheepshead Minnow, Cyprinodon variegatus.

EPA Science Inventory

Sustainability of wildlife populations exposed to endocrine disrupting chemicals in natural water bodies has sparked sufficient concern that the U.S.EPA is developing methods for multiple generation exposures of fishes. Established testing methods and the short life-cycle of the ...

Effects of time and recall of patch test results on quality of life (QoL) after testing. Cross-sectional study analyzing QoL in hand eczema patients 1, 5 and 10 years after patch testing.

PubMed

Jamil, Wasim N; Lindberg, Magnus

2017-08-01

Patch testing can improve health-related quality of life (HRQOL). To study the impact on HRQOL of elapsed time after patch testing (1-10 years), and how the outcome of testing and patients' recall affects HRQOL. The Dermatology Life Quality Index (DLQI) questionnaire was sent to all patients (aged 18-65 years) who were patch tested for suspected contact allergy in 2009, 2005 and 2000 at the Department of Dermatology in Örebro. The response rate was 51% (n = 256). The DLQI score was significantly lower at 10 years after patch testing (mean DLQI = 5.5) than at 1 year (mean DLQI = 7.7). Work was the most impaired aspect. A binary logistic model showed that only time (10 years after testing) was associated with no effect, a light effect or a moderate effect (DLQI < 10) on HRQOL. No such association was seen for patients with negative or positive test results concerning full recall, partial recall or no recall of diagnosed allergens. Although there was an improvement in HRQOL over time, the work aspect remained a major problem. The improvement was not affected by the outcome of testing and patients' recall of test results. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Saltatory ontogeny of fishes and sensitive early life stages for ecotoxicology tests.

PubMed

Belanger, Scott E; Balon, Eugene K; Rawlings, Jane M

2010-04-15

Fish display a wide range of developmental ontogenies. These distinctions have taxonomic, evolutionary, and ecological importance in addition to practical implications on the use of fish in aquatic toxicity tests. With respect to animal welfare, vertebrates are afforded protected or non-protected status in the European Union based upon whether they feed endogenously off the yolk or exogenously by procurement and ingestion of food. The concept of saltatory ontogeny suggests development is not gradual but proceeds in leaps separated by a series of stable developmental states. In this context, endogenous/exogenous feeding also distinguishes the developmental phases of embryo (egg), eleutheroembryo (feeding off the yolk sac) and larvae (exogenous feeding) in fish. The recent proposal for the Fish Embryo Test (FET) as an animal alternative to the standard fish acute toxicity test (OECD 203 and equivalent tests) puts a clear focus on the need to identify the non-protected and protected life intervals in test species as well as their sensitivities which coincides with the developmental phases identified in saltatory ontogeny. In this paper we described a method to quantify embryo, eleutheroembryo, and larva phases in Danio rerio, the zebrafish. Danio eleutheroembryos preyed upon 5 different protozoan species (Euglena, Euplotes, Paramecium aurelia, Paramecium bursaria and Paramecium multimicronucleatum) between 24 and 48hr following hatching (85-95% of fish, n=20 per species, 25 degrees C). Based upon these data it is recommended that testing of developing zebrafish embryos should be terminated between 24 and 48hr after hatching in order to be compliant with existing animal welfare legislation within Europe.

Performance of Small Bore 60NiTi Hybrid Ball Bearings: Preliminary Life Test Results

NASA Technical Reports Server (NTRS)

Dellacorte, Christopher; Howard, S. Adam

2016-01-01

Small bore (R8 size) hybrid ball bearings made with 60NiTi races and silicon nitride balls are under development for highly corrosive aerospace applications that are also exposed to heavy static (shock) loads. The target application is the vacuum pump used inside the wastewater recycling system on the International Space Station. To verify bearing longevity, life tests are run at 2000rpm for time periods up to 5000 hours. Accelerometers with data tracking are used to monitor operation and the bearings are disassembled and inspected at intervals to assess wear. Preliminary tests show that bearings made from 60NiTi are feasible for this aerospace and potentially other industrial applications that must endure similar operating environments.

Synthesis of Sine-on-Random vibration profiles for accelerated life tests based on fatigue damage spectrum equivalence

NASA Astrophysics Data System (ADS)

Angeli, Andrea; Cornelis, Bram; Troncossi, Marco

2018-03-01

In many real life environments, mechanical and electronic systems are subjected to vibrations that may induce dynamic loads and potentially lead to an early failure due to fatigue damage. Thus, qualification tests by means of shakers are advisable for the most critical components in order to verify their durability throughout the entire life cycle. Nowadays the trend is to tailor the qualification tests according to the specific application of the tested component, considering the measured field data as reference to set up the experimental campaign, for example through the so called "Mission Synthesis" methodology. One of the main issues is to define the excitation profiles for the tests, that must have, besides the (potentially scaled) frequency content, also the same damage potential of the field data despite being applied for a limited duration. With this target, the current procedures generally provide the test profile as a stationary random vibration specified by a Power Spectral Density (PSD). In certain applications this output may prove inadequate to represent the nature of the reference signal, and the procedure could result in an unrealistic qualification test. For instance when a rotating part is present in the system the component under analysis may be subjected to Sine-on-Random (SoR) vibrations, namely excitations composed of sinusoidal contributions superimposed to random vibrations. In this case, the synthesized test profile should preserve not only the induced fatigue damage but also the deterministic components of the environmental vibration. In this work, the potential advantages of a novel procedure to synthesize SoR profiles instead of PSDs for qualification tests are presented and supported by the results of an experimental campaign.

Accelerated test design

NASA Technical Reports Server (NTRS)

Mcdermott, P. P.

1980-01-01

The design of an accelerated life test program for electric batteries is discussed. A number of observations and suggestions on the procedures and objectives for conducting an accelerated life test program are presented. Equations based on nonlinear regression analysis for predicting the accelerated life test parameters are discussed.

Alternatives to the Fish Early Life-Stage Test: A Research Strategy for Discovering and Annotating Adverse Outcome Pathways During Fish Development

EPA Science Inventory

The OECD 210 fish early life]stage (FELS) test is the primary guideline test used to estimate chronic fish toxicity, as well as support ecological risk assessments and chemical management programs around the world. As a step toward developing alternatives to the FELS test, a HES...

Development and psychometric testing of the Canine Owner-Reported Quality of Life questionnaire, an instrument designed to measure quality of life in dogs with cancer.

PubMed

Giuffrida, Michelle A; Brown, Dorothy Cimino; Ellenberg, Susan S; Farrar, John T

2018-05-01

OBJECTIVE To describe development and initial psychometric testing of an owner-reported questionnaire designed to standardize measurement of general quality of life (QOL) in dogs with cancer. DESIGN Key-informant interviews, questionnaire development, and field trial. SAMPLE Owners of 25 dogs with cancer for item development and pretesting and owners of 90 dogs with cancer for reliability and validity testing. PROCEDURES Standard methods for development and testing of questionnaire instruments intended to measure subjective states were used. Items were generated, selected, scaled, and pretested for content, meaning, and readability. Response items were evaluated with exploratory factor analysis and by assessing internal consistency (Cronbach α) and convergence with global QOL as determined with a visual analog scale. Preliminary tests of stability and responsiveness were performed. RESULTS The final questionnaire-which was named the Canine Owner-Reported Quality of Life (CORQ) questionnaire-contained 17 items related to observable behaviors commonly used by owners to evaluate QOL in their dogs. Several items pertaining to physical symptoms performed poorly and were omitted. The 17 items were assigned to 4 factors-vitality, companionship, pain, and mobility-on the basis of the items they contained. The CORQ questionnaire and its factors had high internal consistency (Cronbach α = 0.68 to 0.90) and moderate to strong correlations (r = 0.49 to 0.71) with global QOL as measured on a visual analog scale. Preliminary testing indicated good test-retest reliability and responsiveness to improvements in overall QOL. CONCLUSIONS AND CLINICAL RELEVANCE The CORQ questionnaire was a valid, reliable owner-reported questionnaire that measured general QOL in dogs with cancer and showed promise as a clinical trial outcome measure for quantifying changes in individual dog QOL occurring in response to cancer treatment and progression.

Life trajectories, genetic testing, and risk reduction decisions in 18–39 year old women at risk for hereditary breast and ovarian cancer

PubMed Central

Williams, Janet K.; Bowers, Barbara J.; Calzone, Kathleen

2009-01-01

This qualitative study identified four life trajectories that influenced the decision in young women to have genetic testing for mutations in BRCA1/2 and subsequent risk reduction decisions after receiving a positive mutation result. Fifty nine women between the ages of 18–39 years were interviewed in this grounded theory study, 44 of those tested were found to have a mutation in either BRCA1 or BRCA2. Of those with a mutation, 23 had no history of cancer and 21 had a breast cancer diagnosis. Analysis of the 44 participants tested found that risk reducing decisions were related to the life trajectories that preceded genetic testing. These life trajectories included: 1) Long-standing awareness of breast cancer in the family, 2) Loss of one’s mother to breast cancer at a young age, 3) Expression of concern by a health care provider, and 4) Personal diagnosis of breast cancer. Understanding possible influences behind decision making for genetic testing and risk reduction in young women may assist health care providers in offering age appropriate guidance and support. PMID:18979190

Spontaneous locomotor activity and life span. A test of the rate of living theory in Drosophila melanogaster.

PubMed

Lints, F A; Le Bourg, E; Lints, C V

1984-01-01

The spontaneous locomotor activity and life span of approximately 600 individuals of both sexes and of three widely different genotypes of Drosophila melanogaster have been measured. Neither at the individual nor at the populational level could a significant correlation between spontaneous locomotor activity and life span be found. The results are discussed in relation with Pearl's [The rate of living, London University Press, London 1928] rate of living theory. That theory has been tested in relation with environmental temperature, oxygen consumption and activity. It is shown that the theory has received no definite confirmation until now.

Results from raw milk microbiological tests do not predict the shelf-life performance of commercially pasteurized fluid milk.

PubMed

Martin, N H; Ranieri, M L; Murphy, S C; Ralyea, R D; Wiedmann, M; Boor, K J

2011-03-01

Analytical tools that accurately predict the performance of raw milk following its manufacture into commercial food products are of economic interest to the dairy industry. To evaluate the ability of currently applied raw milk microbiological tests to predict the quality of commercially pasteurized fluid milk products, samples of raw milk and 2% fat pasteurized milk were obtained from 4 New York State fluid milk processors for a 1-yr period. Raw milk samples were examined using a variety of tests commonly applied to raw milk, including somatic cell count, standard plate count, psychrotrophic bacteria count, ropy milk test, coliform count, preliminary incubation count, laboratory pasteurization count, and spore pasteurization count. Differential and selective media were used to identify groups of bacteria present in raw milk. Pasteurized milk samples were held at 6°C for 21 d and evaluated for standard plate count, coliform count, and sensory quality throughout shelf-life. Bacterial isolates from select raw and pasteurized milk tests were identified using 16S ribosomal DNA sequencing. Linear regression analysis of raw milk test results versus results reflecting pasteurized milk quality consistently showed low R(2) values (<0.45); the majority of R(2) values were <0.25, indicating small relationship between the results from the raw milk tests and results from tests used to evaluate pasteurized milk quality. Our findings suggest the need for new raw milk tests that measure the specific biological barriers that limit shelf-life and quality of fluid milk products. Copyright © 2011 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Cycle life test. Evaluation program for secondary spacecraft cells. [performance tests on silver zinc batteries, silver cadmium batteries, and nickel cadmium batteries

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1976-01-01

Considerable research is being done to find more efficient and reliable means of starting electrical energy for orbiting satellites. Rechargeable cells offer one such means. A test program is described which has been established in order to further the evaluation of certain types of cells and to obtain performance and failure data as an aid to their continued improvement. The purpose of the program is to determine the cycling performance capabilities of packs of cells under different load and temperature conditions. The various kinds of cells tested were nickel-cadmium, silver-cadmium, and silver-zinc sealed cells. A summary of the results of the life cycling program is given in this report.

Investigating Alternatives to the Fish Early Life-Stage Test: A Strategy for Discovering and Annotating Adverse Outcome Pathways for Early Fish Development

EPA Science Inventory

The fish early life-stage (FELS) test (OECD Test Guideline 210) is the primary test used internationally to estimate chronic fish toxicity in support of ecological risk assessments and chemical management programs. As part of an on-going effort to develop efficient and cost-effec...

Significance of specificity of Tinetti B-POMA test and fall risk factor in third age of life.

PubMed

Avdić, Dijana; Pecar, Dzemal

2006-02-01

As for the third age, psychophysical abilities of humans gradually decrease, while the ability of adaptation to endogenous and exogenous burdens is going down. In 1987, "Harada" et al. (1) have found out that 9.5 million persons in USA have difficulties running daily activities, while 59% of them (which is 5.6 million) are older than 65 years in age. The study has encompassed 77 questioned persons of both sexes with their average age 71.73 +/- 5.63 (scope of 65-90 years in age), chosen by random sampling. Each patient has been questioned in his/her own home and familiar to great extent with the methodology and aims of the questionnaire. Percentage of questioned women was 64.94% (50 patients) while the percentage for men was 35.06% (27 patients). As for the value of risk factor score achieved conducting the questionnaire and B-POMA test, there are statistically significant differences between men and women, as well as between patients who fell and those who never did. As for the way of life (alone or in the community), there are no significant statistical differences. Average results gained through B-POMA test in this study are statistically significantly higher in men and patients who did not provide data about falling, while there was no statistically significant difference in the way of life. In relation to the percentage of maximum number of positive answers to particular questions, regarding gender, way of life and the data about falling, there were no statistically significant differences between the value of B-POMA test and the risk factor score (the questionnaire).

Accelerated life test of sputtering and anode deposit spalling in a small mercury ion thruster

NASA Technical Reports Server (NTRS)

Power, J. L.

1975-01-01

Tantalum and molybdenum sputtered from discharge chamber components during operation of a 5 centimeter diameter mercury ion thruster adhered much more strongly to coarsely grit blasted anode surfaces than to standard surfaces. Spalling of the sputtered coating did occur from a coarse screen anode surface but only in flakes less than a mesh unit long. The results were obtained in a 200 hour accelerated life test conducted at an elevated discharge potential of 64.6 volts. The test approximately reproduced the major sputter erosion and deposition effects that occur under normal operation but at approximately 75 times the normal rate. No discharge chamber component suffered sufficient erosion in the test to threaten its structural integrity or further serviceability. The test indicated that the use of tantalum-surfaced discharge chamber components in conjunction with a fine wire screen anode surface should cure the problems of sputter erosion and sputtered deposits spalling in long term operation of small mercury ion thrusters.

Testing the factor structure of the Family Quality of Life Survey - 2006.

PubMed

Isaacs, B; Wang, M; Samuel, P; Ajuwon, P; Baum, N; Edwards, M; Rillotta, F

2012-01-01

Although the Family Quality of Life Survey - 2006 (FQOLS-2006) is being used in research, there is little evidence to support its hypothesised domain structure. The purpose of this study was to test the domain structure of the survey using confirmatory factor analysis. Samples from Australia, Canada, Nigeria and the USA were analysed using structural equation modelling. The data from Australia, Canada and the USA were combined on the assumption that these countries are similar, at least to some degree, in economic development, language and culture. The Nigerian data were analysed on its own. The analysis was undertaken in two phases. First, the hypothesis that each of nine domains of the FQOLS-2006 is a unidimensional construct that can reliably measure the dimensions Importance, Stability, Opportunities, Attainment, Stability and Satisfaction was tested. Second, the hypothesis that family quality of life (FQoL) is a single latent construct represented by the nine domains measured in the FQOLS-2006 was tested. In the first phase of the analysis, the Importance dimension was dropped because of skewness and lack of variance. The Stability dimension did not fit well within the individual domain model in both the Nigerian and the combined three countries' data. When Importance and Stability were excluded, the individual domain models showede good or acceptable fit when error variances of some dimensions were allowed to correlate. In the second phase of the analysis, the overall model, FQoL, represented by the nine domains of the FQOLS-2006 showed good fit in both data sets. The conceptual model of the FQOLS-2006 was supported with some qualifications. Each domain on the survey can be reliably measured by four dimensions Opportunities, Initiative, Attainment and Satisfaction. The dimensions of Importance and Stability, however, did not fit. Data reported on these dimensions from past and current studies should be interpreted with caution. The construct of FQoL is also

A Review of Quality of Life after Predictive Testing for and Earlier Identification of Neurodegenerative Diseases

PubMed Central

Paulsen, Jane S.; Nance, Martha; Kim, Ji-In; Carlozzi, Noelle E.; Panegyres, Peter K.; Erwin, Cheryl; Goh, Anita; McCusker, Elizabeth; Williams, Janet K.

2013-01-01

The past decade has witnessed an explosion of evidence suggesting that many neurodegenerative diseases can be detected years, if not decades, earlier than previously thought. To date, these scientific advances have not provoked any parallel translational or clinical improvements. There is an urgency to capitalize on this momentum so earlier detection of disease can be more readily translated into improved health-related quality of life for families at risk for, or suffering with, neurodegenerative diseases. In this review, we discuss health-related quality of life (HRQOL) measurement in neurodegenerative diseases and the importance of these “patient reported outcomes” for all clinical research. Next, we address HRQOL following early identification or predictive genetic testing in some neurodegenerative diseases: Huntington disease, Alzheimer's disease, Parkinson's disease, Dementia with Lewy bodies, frontotemporal dementia, amyotrophic lateral sclerosis, prion diseases, hereditary ataxias, Dentatorubral-pallidoluysian atrophy and Wilson's disease. After a brief report of available direct-to-consumer genetic tests, we address the juxtaposition of earlier disease identification with assumed reluctance towards predictive genetic testing. Forty-one studies examining health related outcomes following predictive genetic testing for neurodegenerative disease suggested that (a) extreme or catastrophic outcomes are rare; (b) consequences commonly include transiently increased anxiety and/or depression; (c) most participants report no regret; (d) many persons report extensive benefits to receiving genetic information; and (e) stigmatization and discrimination for genetic diseases are poorly understood and policy and laws are needed. Caution is appropriate for earlier identification of neurodegenerative diseases but findings suggest further progress is safe, feasible and likely to advance clinical care. PMID:24036231

Test Method for the Fatigue Life of Layered TiB/Ti Functionally Graded Beams Subjected to Fully Reversed Bending

NASA Astrophysics Data System (ADS)

Byrd, Larry; Rickerd, Greg; Wyen, Travis; Cooley, Glenn; Quast, Jeff

2008-02-01

Sonic fatigue of aircraft is characterized by fully reversed bending of components subjected to acoustic excitation. This problem is compounded in high temperature environments because solutions for acoustics which tend to result in stiff structures make thermal problems worse. Conversely solutions to the thermal problem which allow expansion often fail in the presence of high acoustic levels. Errors in fatigue life prediction in the combined environment often range from a factor of 4 to 10. This results in either heavy, overly stiff structure or premature failure. This work will test the hypothesis that the fatigue life of a layered functionally graded material (FGM) will be dominated by the failure of the stiffest outer layer. This is based on the observation that for isotropic materials the life is approximately 90% crack initiation and only 10% crack growth before failure. Four sets of cantilever specimens will be tested using an electro-mechanical shaker for base excitation. The excitation will be narrow band random around the fundamental frequency. Two sets of specimens are of uniform composition consisting of 85%TiB/Ti and two are graded specimens consisting of layers that vary from commercially pure titanium to 85%TiB/Ti. Strain vs number of cycles to failure curves will be generated with both constant amplitude sine and narrow band random around the fundamental frequency excitation. The results will be examined to compare life of the uniform material to the functionally graded material. Also to be studied will be the use of Miner's rule to predict the fatigue life of the randomly excited specimens.

Cascade Distillation Subsystem Development: Early Results From the Exploration Life Support Distillation Technology Comparison Test

NASA Technical Reports Server (NTRS)

Callahan, Michael R.; Patel, Vipul; Pickering, Karen D.

2009-01-01

In 2009, the Cascade Distillation Subsystem (CDS) wastewater processor (Honeywell International, Torrance, CA) was assessed in the National Aeronautics and Space Administration (NASA) Exploration Life Support (ELS) distillation comparison test. The purpose of the test was to collect data to support down-selection and development of a primary distillation technology for application in a lunar outpost water recovery system. The CDS portion of the comparison test was conducted between May 6 and August 19, 2009. The system was challenged with two pretreated test solutions, each intended to represent a feasible wastewater generated in a surface habitat. The 30-day equivalent wastewater loading volume for a crew of four was processed for each wastewater solution. Test Solution 1 consisted of a mixed stream containing human-generated urine and humidity condensate. Test Solution 2 contained the addition of human-generated hygiene wastewater to the solution 1 waste stream components. Approximately 1500 kg of total wastewater was processed through the CDS during testing. Respective recoveries per solution were 93.4 +/- 0.7 and 90.3 +/- 0.5%. The average specific energy of the system was calculated to be less than 130 W-hr/kg. The following paper provides detailed information and data on the performance of the CDS as challenged per the ELS distillation comparison test.

User-centered design and usability testing of an innovative health-related quality of life module.

PubMed

Nagykaldi, Z J; Jordan, M; Quitoriano, J; Ciro, C A; Mold, J W

2014-01-01

Various computerized health risk appraisals (HRAs) are available, but few of them assess health-related quality of life (HRQoL) in a goal-directed framework. This study describes the user-centered development and usability testing of an innovative HRQoL module that extends a validated HRA tool in primary care settings. Systematic user-centered design, usability testing, and qualitative methods were used to develop the HRQoL module in primary care practices. Twenty two patients and 5 clinicians participated in two rounds of interactive technology think-out-loud sessions (TOLs) and semi-structured interviews (SSIs) to iteratively develop a four-step, computerized process that collects information on patient goals for meaningful life activities and current level of disability and presents a personalized and prioritized list of preventive recommendations linked to online resources. Analysis of TOLs and SSIs generated 5 categories and 11 sub-categories related to facilitators and barriers to usability and human-technology interaction. The categories included: Understanding the Purpose, Usability, Perceived Value, Literacy, and Participant Motivation. Some categories were inter-connected. The technology was continually and iteratively improved between sessions until saturation of positive feedback was achieved in 4 categories (addressing motivation will require more research). Usability of all screen units of the module was improved substantially. Clinician feedback emphasized the importance of the module's ability to translate the patient-centered HRQoL Report into actionable items for clinicians to facilitate shared decision-making. Complete integration of the HRQoL module into the existing HRA will require further development and testing. Systematic application of user-centered design and human factors principles in technology development and testing may significantly improve the usability and clinical value of health information systems. This more sophisticated

Space Suit Portable Life Support System (PLSS) 2.0 Unmanned Vacuum Environment Testing

NASA Technical Reports Server (NTRS)

Watts, Carly; Vogel, Matthew

2016-01-01

For the first time in more than 30 years, an advanced space suit Portable Life Support System (PLSS) design was operated inside a vacuum chamber representative of the flight operating environment. The test article, PLSS 2.0, was the second system-level integrated prototype of the advanced PLSS design, following the PLSS 1.0 Breadboard that was developed and tested throughout 2011. Whereas PLSS 1.0 included five technology development components with the balance the system simulated using commercial-off-the-shelf items, PLSS 2.0 featured first generation or later prototypes for all components less instrumentation, tubing and fittings. Developed throughout 2012, PLSS 2.0 was the first attempt to package the system into a flight-like representative volume. PLSS 2.0 testing included an extensive functional evaluation known as Pre-Installation Acceptance (PIA) testing, Human-in-the-Loop testing in which the PLSS 2.0 prototype was integrated via umbilicals to a manned prototype space suit for 19 two-hour simulated EVAs, and unmanned vacuum environment testing. Unmanned vacuum environment testing took place from 1/9/15-7/9/15 with PLSS 2.0 located inside a vacuum chamber. Test sequences included performance mapping of several components, carbon dioxide removal evaluations at simulated intravehicular activity (IVA) conditions, a regulator pressure schedule assessment, and culminated with 25 simulated extravehicular activities (EVAs). During the unmanned vacuum environment test series, PLSS 2.0 accumulated 378 hours of integrated testing including 291 hours of operation in a vacuum environment and 199 hours of simulated EVA time. The PLSS prototype performed nominally throughout the test series, with two notable exceptions including a pump failure and a Spacesuit Water Membrane Evaporator (SWME) leak, for which post-test failure investigations were performed. In addition to generating an extensive database of PLSS 2.0 performance data, achievements included requirements and

Validation of the Chinese Version of the Life Orientation Test with a Robust Weighted Least Squares Approach

ERIC Educational Resources Information Center

Li, Cheng-Hsien

2012-01-01

Of the several measures of optimism presently available in the literature, the Life Orientation Test (LOT; Scheier & Carver, 1985) has been the most widely used in empirical research. This article explores, confirms, and cross-validates the factor structure of the Chinese version of the LOT with ordinal data by using robust weighted least…

Sex differences in cognitive ageing: testing predictions derived from life-history theory in a dioecious nematode.

PubMed

Zwoinska, Martyna K; Kolm, Niclas; Maklakov, Alexei A

2013-12-01

Life-history theory maintains that organisms allocate limited resources to different traits to maximize fitness. Learning ability and memory are costly and known to trade-off with longevity in invertebrates. However, since the relationship between longevity and fitness often differs between the sexes, it is likely that sexes will differentially resolve the trade-off between learning and longevity. We used an established associative learning paradigm in the dioecious nematode Caenorhabditis remanei, which is sexually dimorphic for lifespan, to study age-related learning ability in males and females. In particular, we tested the hypothesis that females (the shorter-lived sex) show higher learning ability than males early in life but senesce faster. Indeed, young females outperformed young males in learning a novel association between an odour (butanone) and food (bacteria). However, while learning ability and offspring production declined rapidly with age in females, males maintained high levels of these traits until mid-age. These results not only demonstrate sexual dimorphism in age-related learning ability but also suggest that it conforms to predictions derived from the life-history theory. © 2013.

Advanced Life Support

NASA Technical Reports Server (NTRS)

Chambliss, Joe

2004-01-01

Viewgraphs on Advanced Life Support (ALS) Systems are presented. The topics include: 1) Fundamental Need for Advanced Life Support; 2) ALS organization; 3) Requirements and Rationale; 4) Past Integrated tests; 5) The need for improvements in life support systems; 6) ALS approach to meet exploration goals; 7) ALS Projects showing promise to meet exploration goals; and 9) GRC involvement in ALS.

Cascade Distillation Subsystem Development: Early Results from the Exploration Life Support Distillation Technology Comparison Test

NASA Technical Reports Server (NTRS)

Callahan, Michael R.; Patel, Vipul; Pickering, Karen D.

2010-01-01

In 2009, the Cascade Distillation Subsystem (CDS) wastewater processor (Honeywell International, Torrance, California) was assessed in the National Aeronautics and Space Administration (NASA) Exploration Life Support (ELS) distillation comparison test. The purpose of the test was to collect data to support down-selection and development of a primary distillation technology for application in a lunar outpost water recovery system. The CDS portion of the comparison test was conducted between May 6 and August 19, 2009. The system was challenged with two pretreated test solutions, each intended to represent a feasible wastewater generated in a surface habitat. The 30-day equivalent wastewater loading volume for a crew of four was intended to be processed for each wastewater solution. Test Solution 1 consisted of a mixed stream containing human-generated urine and humidity condensate. Test Solution 2 contained the addition of human-generated hygiene wastewater to the solution 1 waste stream components. Approximately 1500 kg of total wastewater was processed through the CDS during testing. Respective recoveries per solution were 93.4 +/- 0.7 and 90.3 +/- 0.5 percent. The average specific energy of the system during testing was calculated to be less than 120 W-hr/kg. The following paper provides detailed information and data on the performance of the CDS as challenged per the ELS distillation comparison test.

Space Station Freedom Environmental Control and Life Support System (ECLSS) phase 3 simplified integrated test trace contaminant control subsystem performance

NASA Technical Reports Server (NTRS)

Perry, J. L.

1990-01-01

Space Station Freedom environmental control and life support system testing has been conducted at Marshall Space Flight Center since 1986. The phase 3 simplified integrated test (SIT) conducted from July 30, 1989, through August 11, 1989, tested an integrated air revitalization system. During this test, the trace contaminant control subsystem (TCCS) was directly integrated with the bleed stream from the carbon dioxide reduction subsystem. The TCCS performed as expected with minor anomalies. The test set the basis for further characterizing the TCCS performance as part of advance air revitalization system configurations.

Life Skills in Educational Contexts: Testing the Effects of an Intervention Programme

ERIC Educational Resources Information Center

Gomes, A. Rui; Marques, Brazelina

2013-01-01

This study examined the effects of a training programme on students' acquisition of life skills, life satisfaction, life orientation and expectations about academic achievement. Participants were allocated to either an intervention group ("n"?=?41) that took part in a life skills programme, or a control group ("n"?=?43).…

Effects of Hurricane Katrina and Other Adverse Life Events on Adolescent Female Offenders: A Test of General Strain Theory

PubMed Central

Robertson, Angela R.; Stein, Judith A.; Schaefer-Rohleder, Lacey

2011-01-01

This study tested Agnew’s General Strain Theory (GST) by examining the roles of anger, anxiety, and maladaptive coping in mediating the relationship between strain and three outcomes (serious delinquency, minor delinquency, and continued involvement in the juvenile justice system) among adolescent female offenders (N = 261). Strains consisted of adverse life events and exposure to Hurricane Katrina. Greater exposure to Hurricane Katrina was directly related to serious delinquency and maladaptive coping. Hurricane Katrina also had an indirect effect on minor delinquency and Post–Katrina juvenile justice involvement mediated through maladaptive coping. Adverse life events were associated with increased anger, anxiety, and maladaptive coping. Anger mediated the relationship between adverse life events and serious delinquency. Anxiety mediated the relationship between adverse life events and minor delinquency. Maladaptive coping strategies were associated with minor delinquency and juvenile justice involvement. Findings lend support to GST. PMID:21572904

Impact of cataract surgery on vision-related life performances: the usefulness of Real-Life Vision Test for cataract surgery outcomes evaluation

PubMed Central

Ni, W; Li, X; Hou, Z; Zhang, H; Qiu, W; Wang, W

2015-01-01

Purpose Real-Life Vision Test (RLVT) is a newly developed performance-based measures of functional vision. This present study is designed to determine whether it could be a meaningful assessment for cataract surgery outcomes evaluation. Patients and methods Age-related cataract patients (56) who scheduled for bilateral cataract surgery and 44 age-matched controls were evaluated by four types of measurements: (1) demographic, medical, cognitive and depressive evaluation, and the reaction time testing; (2) clinical measures (visual acuity, contrast sensitivity, stereopsis, and color perception); (3) the 25-item National Eye Institute's Visual Functioning Questionnaire (NEI-VFQ); (4) the RLVT. Spearman's coefficients and multiple regression analysis were conducted to investigate the relationship among RLVT, clinical measures, and self-report assessment of visual function. Results The results of RLVT, clinical measures, and NEI-VFQ total scores were improved significantly after cataract surgery. There were no differences between control subjects and post-surgery patients with respect to NEI-VFQ-25 total scores, self-rating depression scale scores and three tasks of RLVT. Change of RLVT was significantly associated with the change of clinical measures in the cataract group. Multiple regression analysis demonstrated that change of distance, intermediate, and near visual acuity, and binocular contrast sensitivity were significant predictors of improvements of RLVT. Conclusions Cataract surgery could improve real-world visual ability effectively for cataract patients. Our study highlights the potential usefulness of RLVT as an adjunct to the current outcomes evaluation system for cataract surgery. The use of RLVT combined with clinical and self-survey methods may be the comprehensive strategy to manifest the impact of cataract surgery on patients' overall vision-related quality of life. PMID:26272444

Adaptability test of lettuce to soil-like substrate in bioregenerative life support system

NASA Astrophysics Data System (ADS)

Min, Yan; Liu, Professor Hong; Wenting, Fu

Plant cultivation using soil-like substrate (SLS) is considered to be a feasible option for building up matter for biological turnover in bioregenerative life support system (BLSS) by many researchers. The characteristics of SLS are different from those of true soil therefore it is very important to study the adaptability of candidate crop to SLS in BLSS. This study was carried out in three successive steps to test the adaptability of lettuce (Lactuca sativa L.) to rice straw SLS in BLSS of China. First, six Chinese specific lettuce cultivars which were selected for Chinese advanced life support system were planted into the same rice straw SLS, which was to determine the more suitable plant cultivar to do the next experiment. The results showed that Sharp Leaf lettuce and Red lettuce were more suitable for SLS than other cultivars. Second, the possibility of increasing the crop yield on the SLS was conducted by changing the soil depth and plant density. Sharp Leaf lettuce and Red lettuce were used into this experiment in order to obtain the highest yield under the smallest soil volume and weight at the same light intensity. Crop edible biomass, crop nutrition content and photosynthetic characteristics were estimated during the experiment. Red lettuce obtained higher biomass and photosynthesis capacity. Lastly, the stability of planting system of lettuce and SLS was evaluated in the closed controlled system. Red lettuce would be the test plant. In this experiment different age lettuce groups would be planted together and gas exchange would be measured. In all of these experiments soil physical and chemical characteristics were also be measured which will be the basal data for further research.

Transport of Sputtered Carbon During Ground-Based Life Testing of Ion Thrusters

NASA Technical Reports Server (NTRS)

Marker, Colin L.; Clemons, Lucas A.; Banks, Bruce A.; Miller, Sharon; Snyder, Aaron; Hung, Ching-Cheh; Karniotis, Christina A.; Waters, Deborah L.

2005-01-01

High voltage, high power electron bombardment ion thrusters needed for deep space missions will be required to be operated for long durations in space as well as during ground laboratory life testing. Carbon based ion optics are being considered for such thrusters. The sputter deposition of carbon and arc vaporized carbon flakes from long duration operation of ion thrusters can result in deposition on insulating surfaces, causing them to become conducting. Because the sticking coefficient is less than one, secondary deposition needs to be considered to assure that shorting of critical components does not occur. The sticking coefficient for sputtered carbon and arc vaporized carbon is measured as well as directional ejection distribution data for carbon that does not stick upon first impact.

Chromium Toxicity Test for Fall Chinook Salmon (Oncorhynchus tshawytscha) Using Hanford Site Groundwater: Onsite Early Life-Stage Toxicity Evaluation

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

Patton, Gregory W; Dauble, Dennis D; Chamness, Mickie A

The objective of this study was to evaluate site-specific effects for early life-stage (eyed eggs to free swimming juveniles) fall chinook salmon that might be exposed to hexavalent chromium from Hanford groundwater sources. Our exposure conditions included hexavalent chromium obtained from Hanford groundwater wells near the Columbia River, Columbia River water as the diluent, and locally adapted populations of fall chinook salmon. This report describes both a 96-hr pretest using rainbow trout eggs and an early life-stage test beginning with chinook salmon eggs.

Mediation and moderation: Testing relationships between symptom status, functional health, and quality of life in HIV patients

PubMed Central

Ryu, Ehri; West, Stephen G.; Sousa, Karen H.

2010-01-01

We extended Wilson and Cleary's (1995) health-related quality of life model to examine the relationships among symptoms status (Symptoms), functional health (Disability), and quality of life (QOL). Using a community sample (N = 956) of male HIV positive patients, we tested a mediation model in which the relationship between Symptoms and QOL is partially mediated by Disability. Common and unique ideas from three approaches to examining moderation of effects in mediational models (Edwards & Lambert, 2007; Preacher, Rucker, & Hayes, 2007; MacKinnon, 2008) were used to test whether (a) the direct relationship of Symptoms to QOL and (b) the relationship of Disability to QOL are moderated by age. In the mediation model, both the direct and the indirect (mediated) effects were significant. The direct relationship of Symptoms to QOL was significantly moderated by age, but the relationship of Disability to QOL was not. High Symptoms were associated with lower QOL at all ages, but that this relationship became stronger at older ages. We compare the three approaches and consider their advantages over traditional approaches to combining mediation and moderation. PMID:20706561

Cycle life testing of lithium-ion batteries for small satellite LEO space missions

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

Mayer, S.T.; Feikert, J.H.; Kaschmitter, J.L.

1993-08-16

In 1990, Sony corporation announced their intention to manufacture a rechargeable lithium ion battery, based on the intercalation of lithium ions into a carbonaceous anode. The cells were first introduced for portable telephone use in June, 1991. (1) A 3.6V average cell voltage (4.1-2.75V range); (2) Excellent cycle life (1200 @ 100% DOD); (3) Good capacity retention (70% after 6 months); (4) Wide temperature range performance ({minus}20 to +60{degrees}C); (5) Excellent Discharge rate (82% capacity at 30 min. discharge rate); (6) Excellent Charge rate (100% Charge in <3 hrs); and (7) High energy density (264 W*hr/1 and 120 Whr/kg formore » ``D`` size cell. These specifications show significant promise for application of these batteries in low earth orbit (LEO) small satellites, particularly when compared to existing NiH{sub 2} and NiCd technology. The very high energy density and specific energy will reduce power system volume and weight. The wide temperature range enables simpler thermal design, particularly for new, small, high power satellites. The materials used in the lithium ion batteries are relatively inexpensive and benign, so that we expect costs to come down substantially in the future. The specified cycle life at 100% DOD is also 50% longer than most NiCds, so low DOD (depth of discharge) performance could be substantial. This study was undertaken to: (a) assess the feasibility for using lithium ion cells on small satellite LEO missions and (b) verify the claims of the manufacturer. This was accomplished by performing a detailed autopsy and various depth of discharge and rate tests on the cells. Of special interest was the cycle life performance of these cell at various depths of discharge DOD`s, to get an initial measure of the reduction in capacity fade with cycle conditions. Low DOD`s are used to extend the life of all batteries used in a space application.« less

Space Suit Portable Life Support System (PLSS) 2.0 Pre-Installation Acceptance (PIA) Testing

NASA Technical Reports Server (NTRS)

Anchondo, Ian; Cox, Marlon; Meginnis, Carly; Westheimer, David; Vogel, Matt R.

2016-01-01

Following successful completion of the space suit Portable Life Support System (PLSS) 1.0 development and testing in 2011, the second system-level prototype, PLSS 2.0, was developed in 2012 to continue the maturation of the advanced PLSS design. This advanced PLSS is intended to reduce consumables, improve reliability and robustness, and incorporate additional sensing and functional capabilities over the current Space Shuttle/International Space Station Extravehicular Mobility Unit (EMU) PLSS. PLSS 2.0 represents the first attempt at a packaged design comprising first generation or later component prototypes and medium fidelity interfaces within a flight-like representative volume. Pre-Installation Acceptance (PIA) is carryover terminology from the Space Shuttle Program referring to the series of test sequences used to verify functionality of the EMU PLSS prior to installation into the Space Shuttle airlock for launch. As applied to the PLSS 2.0 development and testing effort, PIA testing designated the series of 27 independent test sequences devised to verify component and subsystem functionality, perform in situ instrument calibrations, generate mapping data, define set-points, evaluate control algorithms, evaluate hardware performance against advanced PLSS design requirements, and provide quantitative and qualitative feedback on evolving design requirements and performance specifications. PLSS 2.0 PIA testing was carried out in 2013 and 2014 using a variety of test configurations to perform test sequences that ranged from stand-alone component testing to system-level testing, with evaluations becoming increasingly integrated as the test series progressed. Each of the 27 test sequences was vetted independently, with verification of basic functionality required before completion. Because PLSS 2.0 design requirements were evolving concurrently with PLSS 2.0 PIA testing, the requirements were used as guidelines to assess performance during the tests; after the

Space Suit Portable Life Support System (PLSS) 2.0 Pre-Installation Acceptance (PIA) Testing

NASA Technical Reports Server (NTRS)

Watts, Carly; Vogel, Matthew

2016-01-01

Following successful completion of the space suit Portable Life Support System (PLSS) 1.0 development and testing in 2011, the second system-level prototype, PLSS 2.0, was developed in 2012 to continue the maturation of the advanced PLSS design which is intended to reduce consumables, improve reliability and robustness, and incorporate additional sensing and functional capabilities over the current Space Shuttle/International Space Station Extravehicular Mobility Unit (EMU) PLSS. PLSS 2.0 represents the first attempt at a packaged design comprising first generation or later component prototypes and medium fidelity interfaces within a flight-like representative volume. Pre-Installation Acceptance (PIA) is carryover terminology from the Space Shuttle Program referring to the series of test sequences used to verify functionality of the EMU PLSS prior to installation into the Space Shuttle airlock for launch. As applied to the PLSS 2.0 development and testing effort, PIA testing designated the series of 27 independent test sequences devised to verify component and subsystem functionality, perform in situ instrument calibrations, generate mapping data to define set-points for control algorithms, evaluate hardware performance against advanced PLSS design requirements, and provide quantitative and qualitative feedback on evolving design requirements and performance specifications. PLSS 2.0 PIA testing was carried out from 3/20/13 - 3/15/14 using a variety of test configurations to perform test sequences that ranged from stand-alone component testing to system-level testing, with evaluations becoming increasingly integrated as the test series progressed. Each of the 27 test sequences was vetted independently, with verification of basic functionality required before completion. Because PLSS 2.0 design requirements were evolving concurrently with PLSS 2.0 PIA testing, the requirements were used as guidelines to assess performance during the tests; after the completion of PIA

Long life assurance study for manned spacecraft long life hardware. Volume 4: Special long life assurance studies

NASA Technical Reports Server (NTRS)

1972-01-01

Guidelines for the selection of equipment to be used for manned spacecraft in order to assure a five year maintenance-free service life were developed. A special study was conducted to determine the adequacy of the procedures used to determine the quality and effectiveness of various components. The subjects examined are: (1) temperature cycling for acceptance of electronic assemblies; (2) accelerated testing techniques; (3) electronic part screening techniques; (4) electronic part derating practices; (5) vibration life extension of printed circuit board assemblies; and (6) tolerance funnelling and test requirements.

Wind tunnel validation of AeroDyn within LIFES50+ project: imposed Surge and Pitch tests

NASA Astrophysics Data System (ADS)

Bayati, I.; Belloli, M.; Bernini, L.; Zasso, A.

2016-09-01

This paper presents the first set of results of the steady and unsteady wind tunnel tests, performed at Politecnico di Milano wind tunnel, on a 1/75 rigid scale model of the DTU 10 MW wind turbine, within the LIFES50+ project. The aim of these tests is the validation of the open source code AeroDyn developed at NREL. Numerical and experimental steady results are compared in terms of thrust and torque coefficients, showing good agreement, as well as for unsteady measurements gathered with a 2 degree-of-freedom test rig, capable of imposing the displacements at the base of the model, and providing the surge and pitch motion of the floating offshore wind turbine (FOWT) scale model. The measurements of the unsteady test configuration are compared with AeroDyn/Dynin module results, implementing the generalized dynamic wake (GDW) model. Numerical and experimental comparison showed similar behaviours in terms of non linear hysteresis, however some discrepancies are herein reported and need further data analysis and interpretations about the aerodynamic integral quantities, with a special attention to the physics of the unsteady phenomenon.

NMP22 BladderChek Test: point-of-care technology with life- and money-saving potential.

PubMed

Tomera, Kevin M

2004-11-01

A new, relatively obscure tumor marker assay, the NMP22 BladderChek Test (Matritech, Inc.), represents a paradigm shift in the diagnosis and management of urinary bladder cancer (transitional cell carcinoma). Specifically, BladderChek should be employed every time a cystoscopy is performed, with corresponding changes in the diagnostic protocol and the guidelines of the American Urological Association for the diagnosis and management of bladder cancer. Currently, cystoscopy is the reference standard and NMP22 BladderChek Test in combination with cystoscopy improves the performance of cystoscopy. At every stage of disease, BladderChek provides a higher sensitivity for the detection of bladder cancer than cytology, which now represents the adjunctive standard of care. Moreover, BladderChek is four-times more sensitive than cytology and is available at half the cost. Early detection of bladder cancer improves prognosis, quality of life and survival. BladderChek may be analogous to the prostate-specific antigen test and eventually expand beyond the urologic setting into the primary care setting for the testing of high-risk patients characterized by smoking history, occupational exposures or age.

Shelf-life prediction of canned "nasi uduk" using accelerated shelf-life test (ASLT) - Arrhenius model

NASA Astrophysics Data System (ADS)

Kurniadi, Muhamad; Salam, Nur; Kusumaningrum, Annisa; Nursiwi, Asri; Angwar, Mukhamad; Susanto, Agus; Nurhikmat, Asep; Triwiyono, Frediansyah, Andri

2017-01-01

"Nasi Uduk" is one of the Indonesian traditional food made from rice, steamed with coconut milk and seasoning. For optimizing shelf-life, canned "nasi uduk" for military and disaster-response ration, was packed using cylindrical cans of 72,63 × 53,04 mm (Ø × h) in size. One of the important aspects on quality assessment of preserved product was its rancidity. The aim of this research was to determine shelf-life of canned "nasi uduk" using ASLT method of Arrhenius model. Storage temperatures set up at 35, 45 and 55°C for 35 days. Optimization of sterilization process was conducted to achieve the optimum conditions of sterilization. Target lethality value (Fo), microorganism total plate count (TPC) and rancidity levels (TBA) were used as parameters in this research. The results showed that the optimum sterilization conditions were 121 °C for 20 minutes, TPC value of 9.5 × 101 CFU/ml and Fo value 4.14 minutes. Predicted shelf-life of canned "nasi uduk" was 9.6 months which was average TBA value still bellow of the critical point.

Correlation of 6-min walk test with left ventricular function and quality of life in heart failure due to Chagas disease.

PubMed

Chambela, Mayara C; Mediano, Mauro F F; Ferreira, Roberto R; Japiassú, André M; Waghabi, Mariana C; da Silva, Gilberto M S; Saraiva, Roberto M

2017-10-01

To evaluate the correlation of the total distance walked during the six-minute walk test (6MWT) with left ventricular function and quality of life in patients with Chagas Disease (ChD) complicated by heart failure. This is a cross-sectional study of adult patients with ChD and heart failure diagnosed based on Framingham criteria. 6MWT was performed following international guidelines. New York Heart Association functional class, brain natriuretic peptide (BNP) serum levels, echocardiographic parameters and quality of life (SF-36 and MLHFQ questionnaires) were determined and their correlation with the distance covered at the 6MWT was tested. Forty adult patients (19 male; 60 ± 12 years old) with ChD and heart failure were included in this study. The mean left ventricular ejection fraction was 35 ± 12%. Only two patients (5%) ceased walking before 6 min had elapsed. There were no cardiac events during the test. The average distance covered was 337 ± 105 metres. The distance covered presented a negative correlation with BNP (r = -0.37; P = 0.02), MLHFQ quality-of-life score (r = -0.54; P = 0.002), pulmonary artery systolic pressure (r = -0.42; P = 0.02) and the degree of diastolic dysfunction (r = -0.36; P = 0.03) and mitral regurgitation (r = -0.53; P = 0.0006) and positive correlation with several domains of the SF-36 questionnaire. The distance walked during the 6MWT correlates with BNP, quality of life and parameters of left ventricular diastolic function in ChD patients with heart failure. We propose this test to be adopted in endemic areas with limited resources to aid in the identification of patients who need referral for tertiary centres for further evaluation and treatment. © 2017 John Wiley & Sons Ltd.

An integrated fingerprinting and kinetic approach to accelerated shelf-life testing of chemical changes in thermally treated carrot puree.

PubMed

Kebede, Biniam T; Grauwet, Tara; Magpusao, Johannes; Palmers, Stijn; Michiels, Chris; Hendrickx, Marc; Loey, Ann Van

2015-07-15

To have a better understanding of chemical reactions during shelf-life, an integrated analytical and engineering toolbox: "fingerprinting-kinetics" was used. As a case study, a thermally sterilised carrot puree was selected. Sterilised purees were stored at four storage temperatures as a function of time. Fingerprinting enabled selection of volatiles clearly changing during shelf-life. Only these volatiles were identified and studied further. Next, kinetic modelling was performed to investigate the suitability of these volatiles as quality indices (markers) for accelerated shelf-life testing (ASLT). Fingerprinting enabled selection of terpenoids, phenylpropanoids, fatty acid derivatives, Strecker aldehydes and sulphur compounds as volatiles clearly changing during shelf-life. The amount of Strecker aldehydes increased during storage, whereas the rest of the volatiles decreased. Out of the volatiles, based on the applied kinetic modelling, myristicin, α-terpinolene, β-pinene, α-terpineol and octanal were identified as potential markers for ASLT. Copyright © 2015 Elsevier Ltd. All rights reserved.

Intensity of recreational physical activity throughout life and later life cognitive functioning in women.

PubMed

Tierney, Mary C; Moineddin, Rahim; Morra, Angela; Manson, Judith; Blake, Jennifer

2010-01-01

Long-term physical activity may affect risk of cognitive impairment but few studies have examined later life cognition in relation to intensity of life-long physical activity. We examined the associations between the intensity of long-term recreational physical activity and neuropsychological functioning in 90 healthy postmenopausal women on tests found to be useful in the early identification of dementia. Information was collected about their participation in strenuous and moderate activities between high school and menopause. Summary measures of long-term strenuous and moderate activity were constructed for each participant. All analyses were adjusted for relevant covariates. The six linear regression analyses showed significant positive associations between moderate activity and Wechsler Adult Intelligence Scale Revised (WAIS-R), Digit Span backward, WAIS-R Digit Symbol, and Trail Making Test Part B. Significant negative relationships were found between strenuous activity and Rey Auditory Verbal Learning Test delayed verbal recall, Complex Figure Test delayed visual memory, WAIS-R Digit Span backward, category fluency, and WAIS-R Digit Symbol. The associations found in the present study suggest that while moderate activity may be protective, long-term strenuous activity before menopause may lower cognitive performance later in life. These results support further investigation of the effects of life-long exercise intensity on cognition in later life.

Effectiveness of Life Review Therapy on Quality of Life in the Late Life at Day Care Centers of Shiraz, Iran: A Randomized Controlled Trial.

PubMed

Sharif, Farkhondeh; Jahanbin, Iran; Amirsadat, Afsar; Hosseini Moghadam, Mahboobeh

2018-04-01

Life review therapy, used as part of a comprehensive therapy plan for increasing the quality of life of the elderly, helps them to resolve their past conflicts, reconstruct their life stories, and accept their present conditions. The present study aimed to explore the effectiveness of life review therapy on the quality of life of the elderly. The present study was a randomized controlled trial with a pre-posttest design during April to Aug 2014. The study was conducted on 35 members of the elderly day care centers in Shiraz, Iran, that were randomly assigned to two groups (experimental and control). The subjects in the experimental group attended 8 two-hour sessions of life review therapy. The quality of life of the elderly participants was evaluated before, immediately, one month, and three months after the intervention using the quality of life questionnaire (WHOQOL_BREF). Data analysis was conducted through SPSS version 22, using statistical tests including Chi-square, repeated measures test and T-test, with the significance level of 0.05. The results of the study showed that life review therapy interventions significantly improved the quality of life of the elderly (P<0.05). Moreover, group interaction with passage of time was also significant, which indicates that the pattern of changes has been different between the two groups. The findings of the study confirm the research hypotheses, showing that the application of life review is effective and viable. It is recommended that all nursing homes and even the families of the elderly should employ this convenient, inexpensive, quick, and practical method. Trial Registration Number: IRCT2015021621106N1.

Meta-analysis of fish early life stage tests-Association of toxic ratios and acute-to-chronic ratios with modes of action.

PubMed

Scholz, Stefan; Schreiber, Rene; Armitage, James; Mayer, Philipp; Escher, Beate I; Lidzba, Annegret; Léonard, Marc; Altenburger, Rolf

2018-04-01

Fish early life stage (ELS) tests (Organisation for Economic Co-operation and Development test guideline 210) are widely conducted to estimate chronic fish toxicity. In these tests, fish are exposed from the embryonic to the juvenile life stages. To analyze whether certain modes of action are related to high toxic ratios (i.e., ratios between baseline toxicity and experimental effect) and/or acute-to-chronic ratios (ACRs) in the fish ELS test, effect concentrations (ECs) for 183 compounds were extracted from the US Environmental Protection Agency's ecotoxicity database. Analysis of ECs of narcotic compounds indicated that baseline toxicity could be observed in the fish ELS test at similar concentrations as in the acute fish toxicity test. All nonnarcotic modes of action were associated with higher toxic ratios, with median values ranging from 4 to 9.3 × 10 4 (uncoupling < reactivity < neuromuscular toxicity < methemoglobin formation < endocrine disruption < extracellular matrix formation inhibition). Four modes of action were also found to be associated with high ACRs: 1) lysyl oxidase inhibition leading to notochord distortion, 2) putative methemoglobin formation or hemolytic anemia, 3) endocrine disruption, and 4) compounds with neuromuscular toxicity. For the prediction of ECs in the fish ELS test with alternative test systems, endpoints targeted to the modes of action of compounds with enhanced toxic ratios or ACRs could be used to trigger fish ELS tests or even replace these tests. Environ Toxicol Chem 2018;37:955-969. © 2018 SETAC. © 2018 SETAC.

Quality of life and satisfaction with life of malaria patients in context of acceptance of the disease: quantitative studies

PubMed Central

2012-01-01

Background Health status is one of the basic factors of a high quality of life and the problem of the acceptance of illness is important for adaptation to the limitations imposed by it. The purpose of the study was the evaluation of the quality of life, satisfaction with life and the acceptance of illness by malaria patients, as well as the discovery of a relationship between studied parameters. Methods The study was undertaken in August 2010, on 120 Nigerian patients with confirmed malaria. A method of diagnostic survey, based on standardized scales - Acceptance of Illness Scale, The Satisfaction With Life Scale and a standardized survey questionnaire World Health Organization Quality of Life/BREF - was used in this study. Descriptive statistics, variability range, 95% confidence interval, correlation analysis, Spearman’s non-parametric correlation coefficient, Mann–Whitney test and Kruskal-Wallis test were applied and the, so called, test statistics was calculated, followed by the calculation of the test probability p. Results of analyses were presented in a box graph, and a graph of dispersion. Results A dominating share in the adjective scale of the AIS scale was the category of “no acceptance”, given by 71.7% of respondents. The average level of a “somatic domain” was 41.7, and of a “social domain” was 62.8. The mean satisfaction of life evaluation in the SWLS scale was 18 points. The correlation between acceptance of the disease and quality of life for the psychological domain was 0.39***, and between acceptance of the disease and satisfaction with life was 0.40***. The correlation between satisfaction with life and quality of life for the psychological domain was 0.65***, and between satisfaction with life and quality of life for the environment domain was 0.60***. The mean level of AIS for the studied population of men was 16.5, and test probability: p = 0.0014**, and for the environment domain the level was 50, and the test probability

International Space Station Environmental Control and Life Support System Acceptance Testing for Node 1 Temperature and Humidity Control Subsystem

NASA Technical Reports Server (NTRS)

Williams, David E.

2011-01-01

The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Storage (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper will provide a summary of the Node 1 ECLS THC subsystem design and a detailed discussion of the ISS ECLS Acceptance Testing methodology utilized for this subsystem.The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Storage (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper will provide a summary of the Node 1 ECLS THC subsystem design and a detailed discussion of the ISS ECLS Acceptance Testing methodology utilized for this subsystem.

Self-esteem, narcissism, and stressful life events: Testing for selection and socialization.

PubMed

Orth, Ulrich; Luciano, Eva C

2015-10-01

We examined whether self-esteem and narcissism predict the occurrence of stressful life events (i.e., selection) and whether stressful life events predict change in self-esteem and narcissism (i.e., socialization). The analyses were based on longitudinal data from 2 studies, including samples of 328 young adults (Study 1) and 371 adults (Study 2). The effects of self-esteem and narcissism were mutually controlled for each other and, moreover, controlled for effects of depression. After conducting the study-level analyses, we meta-analytically aggregated the findings. Self-esteem had a selection effect, suggesting that low self-esteem led to the occurrence of stressful life events; however, this effect became nonsignificant when depression was controlled for. Regardless of whether depression was controlled for or not, narcissism had a selection effect, suggesting that high narcissism led to the occurrence of stressful life events. Moreover, stressful life events had a socialization effect on self-esteem, but not on narcissism, suggesting that the occurrence of stressful life events decreased self-esteem. Analyses of trait-state models indicated that narcissism consisted almost exclusively of perfectly stable trait variance, providing a possible explanation for the absence of socialization effects on narcissism. The findings have significant implications because they suggest that a person's level of narcissism influences whether stressful life events occur, and that self-esteem is shaped by the occurrence of stressful life events. Moreover, we discuss the possibility that depression mediates the selection effect of low self-esteem on stressful life events. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Testing the Turing Test — do Men Pass It?

NASA Astrophysics Data System (ADS)

Adam, Ruth; Hershberg, Uri; Schul, Yaacov; Solomon, Sorin

We are fascinated by the idea of giving life to the inanimate. The fields of Artificial Life and Artificial Intelligence (AI) attempt to use a scientific approach to pursue this desire. The first steps on this approach hark back to Turing and his suggestion of an imitation game as an alternative answer to the question "can machines think?".1 To test his hypothesis, Turing formulated the Turing test1 to detect human behavior in computers. But how do humans pass such a test? What would you say if you would learn that they do not pass it well? What would it mean for our understanding of human behavior? What would it mean for our design of tests of the success of artificial life? We report below an experiment in which men consistently failed the Turing test.

Draft Test Guideline: Fish Life Cycle Toxicity

EPA Pesticide Factsheets

The following draft test guideline is part of a series of test guidelines that have been developed by EPA for use in the testing of pesticides and toxic substances, and the development of test data for submission to the Agency for review.

The cultural life script as cognitive schema: how the life script shapes memory for fictional life stories.

PubMed

Koppel, Jonathan; Berntsen, Dorthe

2014-01-01

We tested, across three studies, the effect of the cultural life script on memory and its phenomenological properties. We focused in particular on the mnemonic effects of both schema-consistency and frequency in the life script. In addition to testing recognition (in Study 1) and recall (in Studies 2 and 3), we also collected remember/know judgements for remembered events (in Studies 1 and 2) and memory for their emotional valence (in Study 2). Our primary finding was that, across all three studies, higher-frequency events were more memorable than lower-frequency events, as measured through either recognition or recall. We also attained three additional, complementary effects: First, schema-inconsistent events received remember ratings more often than schema-consistent events (in Study 2, with a trend to this effect in Study 1); second, where an event's emotional valence was inconsistent with the life script, memory for its valence was reconstructed to fit the script (in Study 2); and, third, intrusions in recall were disproportionately for life script events (in Study 3), although that was not the case in recognition (in Study 1). We conclude that the life script serves as a cognitive schema in how it shapes memory and its phenomenological properties.

Life balance and well-being: testing a novel conceptual and measurement approach.

PubMed

Sheldon, Kennon M; Cummins, Robert; Kamble, Shanmukh

2010-08-01

Although a balanced life has always been viewed as desirable, there are problems with extant conceptualizations and measures of this construct. Here we introduce 2 new life-balance measures, based on time-use profiles, that address these problems. One defines life balance as objectively equitable time use across multiple life domains, and the other defines life balance as low subjective discrepancy between actual and ideal time-use profiles. Study 1 finds that both measures predict concurrent well-being, in both U.S. and Indian samples. Study 2 shows that fluctuations in balance predict fluctuations in well-being over a 3-week period. Study 3 replicates the Study 1 findings using a different time assessment technique, based on the Day Reconstruction Method. Study 4 assigns participants the month-long goal of enhancing their life balance, finding that those who achieve this goal enhance their well-being. In all 4 studies, the balance effects on well-being were mediated by psychological need satisfaction associated with balance.

Extended Life PZT Stack Test Fixture

NASA Technical Reports Server (NTRS)

Badescu, Mircea; Sherrit, S.; Bao, X.; Aldrich, J.; Bar-Cohen, Y.; Jones, C.

2009-01-01

Piezoelectric stacks are being sought to be used as actuators for precision positioning and deployment of mechanisms in future planetary missions. Beside the requirement for very high operation reliability, these actuators are required for operation at space environments that are considered harsh compared to normal terrestrial conditions.These environmental conditions include low and high temperatures and vacuum or high pressure. Additionally, the stacks are subjected to high stress and in some applications need to operate with a very long lifetime durability.Many of these requirements are beyond the current industry design margins for nominal terrestrial applications. In order to investigate some of the properties that will indicate the durability of such actuators and their limitations we have developed a new type of test fixture that can be easily integrated in various test chambers for simulating environmental conditions, can provide access for multiple measurements while being exposed to adjustable stress levels. We designed and built two test fixtures and these fixtures were made to be adjustable for testing stacks with different dimensions and can be easily used in small or large numbers. The properties that were measured using these fixtures include impedance, capacitance, dielectric loss factor, leakage current, displacement, breakdown voltage, and lifetime performance. The fixtures characteristics and the test capabilities are presented in this paper.

Model 9975 Life Extension Test Package 3 - Interim Report - January 2017

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

Daugherty, W.

2017-01-31

Life extension package LE3 (9975-03203) has been instrumented and subjected to an elevated temperature environment for approximately 8 years. During this time, the cane fiberboard has been maintained at a maximum temperature of ~160 - 165 °F, which was established by a combination of internal (19 watts) and external heat sources. Several tests and parameters were used to characterize the package components. Results from these tests generally indicate agreement between this full-scale shipping package and small-scale laboratory tests on fiberboard samples, including the degradation models based on the laboratory tests. These areas of agreement include the rate of change ofmore » fiberboard weight, dimensions and density, and change in fiberboard thermal conductivity. Corrosion of the lead shield occurred at a high rate during the first several weeks of aging, but dropped significantly after most of the moisture in the fiberboard migrated away from the lead shield. Dimensional measurements of the lead shield indicate that no significant creep deformation has occurred. This is consistent with literature data that predict a very small creep deformation for the time at temperature experienced by this package. The SCV O-rings were verified to remain leak-tight after ~5 years aging at an average temperature of ~170 °F. This package provides an example of the extent to which moisture within a typical fiberboard assembly can redistribute in the presence of a temperature gradient such as might be created by a 19 watt internal heat load. The majority of water within the fiberboard migrated to the bottom layers of fiberboard, with approximately 2 kg of water (2 liters) eventually escaping from the package. Two conditions have developed that are not consistent with package certification requirements. The axial gap at the top of the package increased to a maximum value of 1.549 inches, exceeding the 1 inch criterion. In addition, staining and/or corrosion have formed in a

Life course socio-economic position and quality of life in adulthood: a systematic review of life course models

PubMed Central

2012-01-01

Background A relationship between current socio-economic position and subjective quality of life has been demonstrated, using wellbeing, life and needs satisfaction approaches. Less is known regarding the influence of different life course socio-economic trajectories on later quality of life. Several conceptual models have been proposed to help explain potential life course effects on health, including accumulation, latent, pathway and social mobility models. This systematic review aimed to assess whether evidence supported an overall relationship between life course socio-economic position and quality of life during adulthood and if so, whether there was support for one or more life course models. Methods A review protocol was developed detailing explicit inclusion and exclusion criteria, search terms, data extraction items and quality appraisal procedures. Literature searches were performed in 12 electronic databases during January 2012 and the references and citations of included articles were checked for additional relevant articles. Narrative synthesis was used to analyze extracted data and studies were categorized based on the life course model analyzed. Results Twelve studies met the eligibility criteria and used data from 10 datasets and five countries. Study quality varied and heterogeneity between studies was high. Seven studies assessed social mobility models, five assessed the latent model, two assessed the pathway model and three tested the accumulation model. Evidence indicated an overall relationship, but mixed results were found for each life course model. Some evidence was found to support the latent model among women, but not men. Social mobility models were supported in some studies, but overall evidence suggested little to no effect. Few studies addressed accumulation and pathway effects and study heterogeneity limited synthesis. Conclusions To improve potential for synthesis in this area, future research should aim to increase study

Time dependency of strainrange partitioning life relationships

NASA Technical Reports Server (NTRS)

Kalluri, S.; Manson, S. S.

1984-01-01

The effect of exposure time (or creep rate) on the CP life relationship is established by conducting isothermal CP tests at varying exposure times on 316 Ss at 1300 and 1500 F. A reduction in the CP cycle life is observed with an increase in the exposure time of the CP test at a given inelastic strain-range. This phenomenon is characterized by modifying the Manson-Coffin type of CP relationship. Two new life relationships: (1) the Steady State Creep Rate (SSRC) Modified CP life relationship, and (2) the Failure Time (FT) Modified CP life relationship, are developed in this report. They account for the effect of creep rate and exposure time within the CP type of waveform. The reduction in CP cyclic life in the long exposure time tests is attributed to oxidation and the precipitation of carbides along the grain boundaries.

Psychometric properties of the Purpose-In-Life Test and age-related differences among women diagnosed with eating disorders.

PubMed

García-Alandete, Joaquín; Ros, Montserrat Cañabate; Salvador, José Heliodoro Marco; Rodríguez, Sandra Pérez

2018-03-01

The aim of this study was to analyze the psychometric properties of the Purpose-In-Life Test (PIL), as well as the age-related differences in meaning in life in women diagnosed with eating disorders. Participants were 250 Spanish women diagnosed with eating disorders who ranged from 12 to 60 years old. Confirmatory Factor Analysis, descriptive analyses, estimation of the internal consistency of the PIL, correlations between the PIL and the Beck Hopelessness Scale (BHS), Overweight Preoccupation Scale (OPS), and Body Investment Scale (BIS), and age differences were calculated. A 19-item model that showed a good fit and internal consistency, a negative correlation between the PIL and both the BHS and OPS, and a positive correlation with the BIS, as well as significant differences between the adolescents and the mature adults, were found. It would be advisable to increase the inclusion of meaning in life in psychotherapeutic interventions with women diagnosed with eating disorders. Copyright © 2017 Elsevier B.V. All rights reserved.

Cognitive Personality Characteristics Impact the Course of Depression: A Prospective Test of Sociotropy, Autonomy and Domain-Specific Life Events.

PubMed

Iacoviello, Brian M; Grant, David A; Alloy, Lauren B; Abramson, Lyn Y

2009-01-01

Prospective tests of the impact of sociotropy and autonomy on the course of depression are lacking. In a sample of 97 cognitive high-risk and 62 cognitive low-risk undergraduates who experienced at least one prospective depressive episode, the interactions of sociotropy and interpersonal life events and autonomy and achievement-related life events were examined as predictors of four indicators of the course of depression. Initial analyses failed to support the hypothesis that global scores for sociotropy and autonomy interact with domain-congruent life events to predict the course indicators. The autonomy-achievement events interaction predicted less severe episodes, contrary to hypothesis. Then, factors hypothesized to underlie Sociotropy (Fear of Criticism and Rejection; Preference for Affiliation) and Autonomy were also analyzed. The puzzling autonomy-achievement life event interaction was explained by the underlying Independent Goal Attainment factor. Interactions between Fear of Criticism and Rejection and achievement events, and between Sensitivity to Others' Control and interpersonal events, significantly predicted chronicity, number and severity of episodes. The findings are discussed in terms of the event-congruency hypothesis.

Behavioural mediators of genetic life-history trade-offs: a test of the pace-of-life syndrome hypothesis in field crickets.

PubMed

Santostefano, Francesca; Wilson, Alastair J; Niemelä, Petri T; Dingemanse, Niels J

2017-10-11

The pace-of-life syndrome (POLS) hypothesis predicts associations between life history and 'risky' behaviours. Individuals with 'fast' lifestyles should develop faster, reproduce earlier, exhibit more risk-prone behaviours, and die sooner than those with 'slow' lifestyles. While support for POLS has been equivocal to date, studies have relied on individual-level (phenotypic) patterns in which genetic trade-offs may be masked by environmental effects on phenotypes. We estimated genetic correlations between life history (development, lifespan, size) and risky behaviours (exploration, aggression) in a pedigreed population of Mediterranean field crickets ( Gryllus bimaculatus ). Path analyses showed that behaviours mediated some genetic relationships between life history traits, though not those involved in trade-offs. Thus, while specific predictions of POLS theory were not supported, genetic integration of behaviour and life history was present. This implies a major role for risky behaviours in life history evolution. © 2017 The Author(s).

Training and certification program of the operating staff for a 90-day test of a regenerative life support system

NASA Technical Reports Server (NTRS)

1972-01-01

Prior to beginning a 90-day test of a regenerative life support system, a need was identified for a training and certification program to qualify an operating staff for conducting the test. The staff was responsible for operating and maintaining the test facility, monitoring and ensuring crew safety, and implementing procedures to ensure effective mission performance with good data collection and analysis. The training program was designed to ensure that each operating staff member was capable of performing his assigned function and was sufficiently cross-trained to serve at certain other positions on a contingency basis. Complicating the training program were budget and schedule limitations, and the high level of sophistication of test systems.

Quality of life philosophy I. Quality of life, happiness, and meaning in life.

PubMed

Ventegodt, Søren; Andersen, Niels Jørgen; Merrick, Joav

2003-12-01

In the Danish Quality of Life Survey, we asked 10,000 people about their quality of life with the validated SEQOL questionnaire with more than 300 questions on their quality of life. How did they feel? How content were they with their lives? How happy were they? Did they feel their needs were fulfilled? And many more questions. We asked the questions we believed to be important for their quality of life (QOL). The results were quite surprising and forced us to recontemplate the following philosophical questions: What is quality of life, happiness, and meaning in life? What is a human being? Do we need a new biology? Is the brain the seat of consciousness? How do we seize the meaning of life and by doing so, will we become well again? What are the key concepts of quality of life? The meaning of life is connectedness and development. It is about realizing every opportunity and potential in one"s existence. The opportunities must be found and acknowledged. What do you find when you find yourself deep down? You find your real self and your purpose in life. You realize that you are already a part of a larger totality. Antonovsky called it "coherence". Maslow called it "transcendence". Frankl called it "meaning of life". We call it simply "being". To test if these philosophical questions are actually relevant for medicine, we looked at the consequences for patients being taught the quality of life philosophy. Quite surprisingly we learned from our pilot studies with "quality of life as medicine" that just by assimilating the basic concepts of the quality of life philosophy presented in this series of papers, patients felt better and saw their lives as more meaningful. The improvement of the patient"s personal philosophy of life seems to be the essence of holistic medicine, helping the patient to assume more responsibility for his or her own existence.

Evaluating weather factors and material response during outdoor exposure to determine accelerated test protocols for predicting service life

Treesearch

R. Sam Williams; Steven Lacher; Corey Halpin; Christopher White

2005-01-01

To develop service life prediction methods for the study of sealants, a fully instrumented weather station was installed at an outdoor test site near Madison, WI. Temperature, relative humidiy, rainfall, ultraviolet (UV) radiation at 18 wavelengths, and wind speed and direction are being continuously measured and stored. The weather data can be integrated over time to...

The Validity and Test-Retest Reliability of the Leeds Multiple Sclerosis Quality of Life Scale in Turkish Patients

ERIC Educational Resources Information Center

Akbiyik, Derya Iren; Sumbuloglu, Vildan; Guney, Zafer; Armutlu, Kadriye; Korkmaz, Nilufer; Keser, Ilke; Yuksel, Muazzez Merve; Karabudak, Rana

2009-01-01

The aim of the study was to translate and test the reliability and validity of the Leeds Multiple Sclerosis Quality of Life Scale (LMSQoL) in Turkish patients with multiple sclerosis (MS). Demographic data of MS patients who had a registration in and followed up by a university hospital were recorded. The LMSQoL and Turkish Quality of Life…

The potential of clustering methods to define intersection test scenarios: Assessing real-life performance of AEB.

PubMed

Sander, Ulrich; Lubbe, Nils

2018-04-01

Intersection accidents are frequent and harmful. The accident types 'straight crossing path' (SCP), 'left turn across path - oncoming direction' (LTAP/OD), and 'left-turn across path - lateral direction' (LTAP/LD) represent around 95% of all intersection accidents and one-third of all police-reported car-to-car accidents in Germany. The European New Car Assessment Program (Euro NCAP) have announced that intersection scenarios will be included in their rating from 2020; however, how these scenarios are to be tested has not been defined. This study investigates whether clustering methods can be used to identify a small number of test scenarios sufficiently representative of the accident dataset to evaluate Intersection Automated Emergency Braking (AEB). Data from the German In-Depth Accident Study (GIDAS) and the GIDAS-based Pre-Crash Matrix (PCM) from 1999 to 2016, containing 784 SCP and 453 LTAP/OD accidents, were analyzed with principal component methods to identify variables that account for the relevant total variances of the sample. Three different methods for data clustering were applied to each of the accident types, two similarity-based approaches, namely Hierarchical Clustering (HC) and Partitioning Around Medoids (PAM), and the probability-based Latent Class Clustering (LCC). The optimum number of clusters was derived for HC and PAM with the silhouette method. The PAM algorithm was both initiated with random start medoid selection and medoids from HC. For LCC, the Bayesian Information Criterion (BIC) was used to determine the optimal number of clusters. Test scenarios were defined from optimal cluster medoids weighted by their real-life representation in GIDAS. The set of variables for clustering was further varied to investigate the influence of variable type and character. We quantified how accurately each cluster variation represents real-life AEB performance using pre-crash simulations with PCM data and a generic algorithm for AEB intervention. The

Alternator insulation evaluation tests

NASA Technical Reports Server (NTRS)

Penn, W. B.; Schaefer, R. F.; Balke, R. L.

1972-01-01

Tests were conducted to predict the remaining electrical insulation life of a 60 KW homopolar inductor alternator following completion of NASA turbo-alternator endurance tests for SNAP-8 space electrical power systems application. The insulation quality was established for two alternators following completion of these tests. A step-temperature aging test procedure was developed for insulation life prediction and applied to one of the two alternators. Armature winding insulation life of over 80,000 hours for an average winding temperature of 248 degrees C was predicted using the developed procedure.

Design and test status for life support applications of SPE oxygen generation systems. [Solid Polymer Electrolyte

NASA Technical Reports Server (NTRS)

Titterington, W. A.; Erickson, A. C.

1975-01-01

An advanced six-man rated oxygen generation system has been fabricated and tested as part of a NASA/JSC technology development program for a long lived, manned spacecraft life support system. Details of the design and tests results are presented. The system is based on the Solid Polymer Electrolyte (SPE) water electrolysis technology and its nominal operating conditions are 2760 kN/sq m (400 psia) and 355 K (180 F) with an electrolysis module current density capability up to 350 mA/sq cm (326 ASF). The system is centered on a 13-cell SPE water electrolysis module having a single cell active area of 214 sq cm (33 sq in) and it incorporates instrumentation and controls for single pushbutton automatic startup/shutdown, component fault detection and isolation, and self-contained sensors and controls for automatic safe emergency shutdown. The system has been tested in both the orbital cyclic and continuous mode of operation. Various parametric tests have been completed to define the system capability for potential application in spacecraft environmental systems.

SSME main combustion chamber life prediction

NASA Technical Reports Server (NTRS)

Cook, R. T.; Fryk, E. E.; Newell, J. F.

1983-01-01

Typically, low cycle fatigue life is a function of the cyclic strain range, the material properties, and the operating temperature. The reusable life is normally defined by the number of strain cycles that can be accrued before severe material degradation occurs. Reusable life is normally signified by the initiation or propagation of surface cracks. Hot-fire testing of channel wall combustors has shown significant mid-channel wall thinning or deformation during accrued cyclic testing. This phenomenon is termed cyclic-creep and appears to be significantly accelerated at elevated surface temperatures. This failure mode was analytically modelled. The cyclic life of the baseline SSME-MCC based on measured calorimeter heat transfer data, and the life sensitivity of local hot spots caused by injector effects were determined. Four life enhanced designs were assessed.

Boiler-turbine life extension

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

Natzkov, S.; Nikolov, M.

1995-12-01

The design life of the main power equipment-boilers and turbines is about 105 working hours. The possibilities for life extension are after normatively regulated control tests. The diagnostics and methodology for Boilers and Turbines Elements Remaining Life Assessment using up to date computer programs, destructive and nondestructive control of metal of key elements of units equipment, metal creep and low cycle fatigue calculations. As well as data for most common damages and some technical decisions for elements life extension are presented.

Quality of Life Philosophy I. Quality of Life, Happiness, and Meaning in Life

PubMed Central

Ventegodt, Søren; Andersen, Niels Jørgen; Merrick, Joav

2003-01-01

In the Danish Quality of Life Survey, we asked 10,000 people about their quality of life with the validated SEQOL questionnaire with more than 300 questions on their quality of life. How did they feel? How content were they with their lives? How happy were they? Did they feel their needs were fulfilled? And many more questions. We asked the questions we believed to be important for their quality of life (QOL). The results were quite surprising and forced us to recontemplate the following philosophical questions: What is quality of life, happiness, and meaning in life? What is a human being? Do we need a new biology? Is the brain the seat of consciousness? How do we seize the meaning of life and by doing so, will we become well again? What are the key concepts of quality of life? The meaning of life is connectedness and development. It is about realizing every opportunity and potential in one’s existence. The opportunities must be found and acknowledged. What do you find when you find yourself deep down? You find your real self and your purpose in life. You realize that you are already a part of a larger totality. Antonovsky called it “coherence”. Maslow called it “transcendence”. Frankl called it “meaning of life”. We call it simply “being”.To test if these philosophical questions are actually relevant for medicine, we looked at the consequences for patients being taught the quality of life philosophy. Quite surprisingly we learned from our pilot studies with “quality of life as medicine” that just by assimilating the basic concepts of the quality of life philosophy presented in this series of papers, patients felt better and saw their lives as more meaningful. The improvement of the patient’s personal philosophy of life seems to be the essence of holistic medicine, helping the patient to assume more responsibility for his or her own existence. PMID:14646011

Experimental control requirements for life sciences

NASA Technical Reports Server (NTRS)

Berry, W. E.; Sharp, J. C.

1978-01-01

The Life Sciences dedicated Spacelab will enable scientists to test hypotheses in various disciplines. Building upon experience gained in mission simulations, orbital flight test experiments, and the first three Spacelab missions, NASA will be able to progressively develop the engineering and management capabilities necessary for the first Life Sciences Spacelab. Development of experiments for these missions will require implementation of life-support systems not previously flown in space. Plant growth chambers, animal holding facilities, aquatic specimen life-support systems, and centrifuge-mounted specimen holding units are examples of systems currently being designed and fabricated for flight.

Life of LED-Based White Light Sources

NASA Astrophysics Data System (ADS)

Narendran, Nadarajah; Gu, Yimin

2005-09-01

Even though light-emitting diodes (LEDs) may have a very long life, poorly designed LED lighting systems can experience a short life. Because heat at the p-n-junction is one of the main factors that affect the life of the LED, by knowing the relationship between life and heat, LED system manufacturers can design and build long-lasting systems. In this study, several white LEDs from the same manufacturer were subjected to life tests at different ambient temperatures. The exponential decay of light output as a function of time provided a convenient method to rapidly estimate life by data extrapolation. The life of these LEDs decreases in an exponential manner with increasing temperature. In a second experiment,several high-power white LEDs from different manufacturers were life-tested under similar conditions. Results show that the different products have significantly different life values.

Assessing variability in chemical acute toxicity of unionid mussels: Influence of intra- and inter-laboratory testing, life stage, and species

EPA Science Inventory

The authors developed a toxicity database for unionid mussels to examine the extent of intra- and interlaboratory variability in acute toxicity tests with mussel larvae (glochidia) and juveniles; the extent of differential sensitivity of the 2 life stages; and the variation in se...

Accelerated life-test methods and results for implantable electronic devices with adhesive encapsulation.

PubMed

Huang, Xuechen; Denprasert, Petcharat May; Zhou, Li; Vest, Adriana Nicholson; Kohan, Sam; Loeb, Gerald E

2017-09-01

We have developed and applied new methods to estimate the functional life of miniature, implantable, wireless electronic devices that rely on non-hermetic, adhesive encapsulants such as epoxy. A comb pattern board with a high density of interdigitated electrodes (IDE) could be used to detect incipient failure from water vapor condensation. Inductive coupling of an RF magnetic field was used to provide DC bias and to detect deterioration of an encapsulated comb pattern. Diodes in the implant converted part of the received energy into DC bias on the comb pattern. The capacitance of the comb pattern forms a resonant circuit with the inductor by which the implant receives power. Any moisture affects both the resonant frequency and the Q-factor of the resonance of the circuitry, which was detected wirelessly by its effects on the coupling between two orthogonal RF coils placed around the device. Various defects were introduced into the comb pattern devices to demonstrate sensitivity to failures and to correlate these signals with visual inspection of failures. Optimized encapsulation procedures were validated in accelerated life tests of both comb patterns and a functional neuromuscular stimulator under development. Strong adhesive bonding between epoxy and electronic circuitry proved to be necessary and sufficient to predict 1 year packaging reliability of 99.97% for the neuromuscular stimulator.

Nickel hydrogen low Earth orbit life testing

NASA Technical Reports Server (NTRS)

Badcock, C. C.; Haag, R. L.

1986-01-01

A program to demonstrate the long term reliability of NiH2 cells in low Earth orbits (LEO) and support use in mid-altitude orbits (MAO) was initiated. Both 3.5 and 4.5 inch diameter nickel hydrogen cells are included in the test plan. Cells from all U.S. vendors are to be tested. The tests will be performed at -5 and 10 C at 40 and 60% DOD for LEO orbit and 10 C and 80% DOD for MAO orbit simulations. The goals of the testing are 20,000 cycles at 60% DOD and 30,000 cycles at 40% DOD. Cells are presently undergoing acceptance and characterization testing at Naval Weapons Systems Center, Crane.

A test of life-history theories of immune defence in two ecotypes of the garter snake, Thamnophis elegans.

PubMed

Sparkman, Amanda Marie; Palacios, Maria Gabriela

2009-11-01

1. Life-history theorists have long observed that fast growth and high reproduction tend to be associated with short life span, suggesting that greater investment in such traits may trade off with self-maintenance. The immune system plays an integral role in self-maintenance and has been proposed as a mediator of life-history trade-offs. 2. Ecoimmunologists have predicted that fast-living organisms should rely more heavily on constitutive innate immunity than slow-living organisms, as constitutive innate defences are thought to be relatively inexpensive to develop and can provide a rapid, general response to pathogens. 3. We present the first study to examine this hypothesis in an ectothermic vertebrate, by testing for differences in three aspects of constitutive innate immunity in replicate populations of two life-history ecotypes of the garter snake Thamnophis elegans, one fast-living and one slow-living. 4. As predicted, free-ranging snakes from the fast-living ecotype had higher levels of all three measures of constitutive innate immunity than the slow-living ecotype. These differences in immunity were not explained by parasite loads measured. Furthermore, both ecotypes exhibited a positive relationship between innate immunity and body size/age, which we discuss in the context of ectotherm physiology and ecotype differences in developmental rates.

Formal Functional Test Designs: Bridging the Gap Between Test Requirements and Test Specifications

NASA Technical Reports Server (NTRS)

Hops, Jonathan

1993-01-01

This presentation describes the testing life cycle, the purpose of the test design phase, and test design methods and gives an example application. Also included is a description of Test Representation Language (TRL), a summary of the language, and an example of an application of TRL. A sample test requirement and sample test design are included.

Life without Scan-Tron: Tests as Thinking.

ERIC Educational Resources Information Center

Posner, Richard

1987-01-01

Claims that written tests are superior to objective, scan-tron tests in literature, composition, and vocabulary because they require students to think on paper. Describes the following types of in-class written tests and examines the advantages of each: literary essay, topical composition, imitation, brief answer, timed rewrites, and vocabulary…

42 CFR 84.207 - Bench tests; gas and vapor tests; minimum requirements; general.

Code of Federal Regulations, 2013 CFR

2013-10-01

....) Flowrate (l.p.m.) Number of tests Penetration 1 (p.p.m.) Minimum life 2 (min.) Ammonia As received NH3 1000... minimum life shall be one-half that shown for each type of gas or vapor. Where a respirator is designed... at predetermined concentrations and rates of flow, and that has means for determining the test life...

42 CFR 84.207 - Bench tests; gas and vapor tests; minimum requirements; general.

Code of Federal Regulations, 2014 CFR

2014-10-01

....) Flowrate (l.p.m.) Number of tests Penetration 1 (p.p.m.) Minimum life 2 (min.) Ammonia As received NH3 1000... minimum life shall be one-half that shown for each type of gas or vapor. Where a respirator is designed... at predetermined concentrations and rates of flow, and that has means for determining the test life...

42 CFR 84.207 - Bench tests; gas and vapor tests; minimum requirements; general.

Code of Federal Regulations, 2012 CFR

2012-10-01

....) Flowrate (l.p.m.) Number of tests Penetration 1 (p.p.m.) Minimum life 2 (min.) Ammonia As received NH3 1000... minimum life shall be one-half that shown for each type of gas or vapor. Where a respirator is designed... at predetermined concentrations and rates of flow, and that has means for determining the test life...

Destructive physical analysis of hollow cathodes from the Deep Space 1 Flight spare ion engine 30,000 hr life test

NASA Technical Reports Server (NTRS)

Sengupta, Anita

2005-01-01

Destructive physical analysis of the discharge and neutralizer hollow cathode assemblies from the Deep Space 1 Flight Spare 30,000 Hr life test was performed to characterize physical and chemical evidence of operationally induced effects after 30,372 hours of operation with beam extraction. Post-test inspection of the discharge-cathode assembly was subdivided into detailed analyses at the subcomponent level. Detailed materials analysis and optical inspection of the insert, orifice plate, cathode tube, heater, keeper assembly, insulator, and low-voltage propellant isolator were performed. Energy dispersive X-ray (EDX) and scanning electron microscopy (SEW analyses were used to determine the extent and composition of regions of net deposition and erosion of both the discharge and neutralizer inserts. A comparative approach with an un-operated 4:1:1 insert was used to determine the extent of impregnate material depletion as a function of depth from the ID surface and axial position from the orifice plate. Analysis results are compared and contrasted with those obtained from similar analyses on components from shorter term tests, and provide insight regarding the prospect for successful longer-term operation consistent with SOA ion engine program life objectives at NASA.

A Tale of Two Chambers: Iterative Approaches and Lessons Learned from Life Support Systems Testing in Altitude Chambers

NASA Technical Reports Server (NTRS)

Callini, Gianluca

2016-01-01

With a brand new fire set ablaze by a serendipitous convergence of events ranging from a science fiction novel and movie ("The Martian"), to ground-breaking recent discoveries of flowing water on its surface, the drive for the journey to Mars seems to be in a higher gear than ever before. We are developing new spacecraft and support systems to take humans to the Red Planet, while scientists on Earth continue using the International Space Station as a laboratory to evaluate the effects of long duration space flight on the human body. Written from the perspective of a facility test director rather than a researcher, and using past and current life support systems tests as examples, this paper seeks to provide an overview on how facility teams approach testing, the kind of information they need to ensure efficient collaborations and successful tests, and how, together with researchers and principal investigators, we can collectively apply what we learn to execute future tests.

Estimation of shelf life of wikau maombo brownies cake using Accelerated Shelf Life Testing (ASLT) method with Arrhenius model

NASA Astrophysics Data System (ADS)

Wahyuni, S.; Holilah; Asranudin; Noviyanti

2018-02-01

The shelf life of brownies cake made from wikau maombo flour was predicted by ASLT method through the Arrhenius model. The aim of this study was to estimate the shelf life of brownies cake made from wikau maombo flour. The storage temperature of brownies cake was carried out at 20°C, 30°C and 45°C. The results showed that TBA (Thio Barbaturic Acid) number of brownies cake decreased as the storage temperature increase. Brownies stored at 20°C and 30°C were overgrown with mold on the storage time of six days. Brownies product (WT0 and WT1) had shelf life at 40°C approximately six and fourteen days, respectively. Brownies made from wikau maombo and wheat flour (WT1) was the best product with had the longest of shelf life about fourteen days.

Test of a life support system with Hirudo medicinalis in a sounding rocket.

PubMed

Lotz, R G; Baum, P; Bowman, G H; Klein, K D; von Lohr, R; Schrotter, L

1972-01-01

Two Nike-Tomahawk rockets each carrying two Biosondes were launched from Wallops Island, Virginia, the first on 10 December 1970 and the second on 16 December 1970. The primary objective of both flights was to test the Biosonde life support system under a near weightless environment and secondarily to subject the Hirudo medicinalis to the combined stresses of a rocket flight. The duration of the weightless environment was approximately 6.5 minutes. Data obtained during the flight by telemetry was used to ascertain the operation of the system and the movements of the leeches during flight. Based on the information obtained, it has been concluded that the operation of the Biosondes during the flight was similar to that observed in the laboratory. The experiment and equipment are described briefly and the flight results presented.

International Space Station Environmental Control and Life Support System Acceptance Testing for the Pressurized Mating Adapters

NASA Technical Reports Server (NTRS)

Williams, David E.

2008-01-01

The International Space Station (ISS) Pressurized Mating Adapters (PMAs) Environmental Control and Life Support (ECLS) System is comprised of three subsystems: Atmosphere Control and Supply (ACS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). PMAs 1 and 2 flew to ISS on Flight 2A and Pressurized Mating Adapter (PMA) 3 flew to ISS on Flight 3A. This paper provides a summary of the PMAs ECLS design and a detailed discussion of the ISS ECLS Acceptance Testing methodologies utilized for the PMAs.

Natriuretic Peptides, 6-Min Walk Test, and Quality-of-Life Questionnaires as Clinically Meaningful Endpoints in HF Trials.

PubMed

Ferreira, João Pedro; Duarte, Kevin; Graves, Todd L; Zile, Michael R; Abraham, William T; Weaver, Fred A; Lindenfeld, JoAnn; Zannad, Faiez

2016-12-20

The Expedited Access for Premarket Approval and De Novo Medical Devices Intended for Unmet Medical Need for Life Threatening or Irreversibly Debilitating Diseases or Conditions document was issued as a guidance for industry and for the Food and Drug Administration. The Expedited Access Pathway was designed as a new program for medical devices that demonstrated the potential to address unmet medical needs for life threatening or irreversibly debilitating conditions. The Food and Drug Administration would consider assessments of a device's effect on intermediate endpoints that, when improving in a congruent fashion, are reasonably likely to predict clinical benefit. The purpose of this review is to provide evidence to support the use of 3 such intermediate endpoints: natriuretic peptides, such as N-terminal pro-B-type natriuretic peptide/B-type natriuretic peptide, the 6-min walk test distance, and health-related quality of life in heart failure. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Psychometric Testing of Two Chinese-Version Scales on Attitudes Toward and Caregiving Behaviors for End-of-Life Patients and Families.

PubMed

Yang, Luke; Liu, Yung-Fang; Sun, Huey-Fang; Chiang, Hsien-Hsien; Tsai, Yu-Lun; Liaw, Jen-Jiuan

2017-03-01

The study purpose was to examine the validities and reliabilities of the Chinese-versions Frommelt Attitudes Toward Care of the Dying Scale (Attitudes Scale) and Caregiving Behaviors Scale for End-of-Life Patients and Families (Behaviors Scale). The scales were tested in a convenience sample of 318 nurses with ≥6 months work experience at three hospitals. Cronbach's alphas of the Attitudes and Behaviors Scales were .90 and .96, respectively. Each scale had Kaiser-Meyer-Olkin index >.85 and Bartlett's test of sphericity >4000 ( p < .001). Attitudes Scale loaded on three factors: respecting and caring for dying patients and families, avoiding care of the dying, and involving patients and families in end-of-life care. The Behaviors Scale loaded on two factors: supporting dying patients and families, and helping families cope with grief. Factor loadings for both scales were ≥.49. Both Attitudes and Behaviors Scales are reliable and valid for evaluating nurses' attitudes and caregiving behaviors for the dying.

Experimentally Testing Hydrothermal Vent Origin of Life on Enceladus and Other Icy/Ocean Worlds.

PubMed

Barge, Laura M; White, Lauren M

2017-09-01

We review various laboratory strategies and methods that can be utilized to simulate prebiotic processes and origin of life in hydrothermal vent systems on icy/ocean worlds. Crucial steps that could be simulated in the laboratory include simulations of water-rock chemistry (e.g., serpentinization) to produce hydrothermal fluids, the types of mineral catalysts and energy gradients produced in vent interfaces where hydrothermal fluids interface with the surrounding seawater, and simulations of biologically relevant chemistry in flow-through gradient systems (i.e., far-from-equilibrium experiments). We describe some examples of experimental designs in detail, which are adaptable and could be used to test particular hypotheses about ocean world energetics or mineral/organic chemistry. Enceladus among the ocean worlds provides an ideal test case, since the pressure at the ocean floor is more easily simulated in the lab. Results for Enceladus could be extrapolated with further experiments and modeling to understand other ocean worlds. Key Words: Enceladus-Ocean worlds-Icy worlds-Hydrothermal vent-Iron sulfide-Gradient. Astrobiology 17, 820-833.

Thoracic Injury Risk as a Function of Crash Severity - Car-to-car Side Impact Tests with WorldSID Compared to Real-life Crashes.

PubMed

Sunnevång, Cecilia; Rosén, Erik; Boström, Ola; Lechelt, Ulf

2010-01-01

Side airbags reduce the risk of fatal injury by approximately 30%. Due to limited real-life data the risk reducing effect for serious injury has not yet been established. Since side airbags are mainly designed and validated for crash severities used in available test procedures little is known regarding the protective effect when severity increases.The objective of this study was to understand for which crash severities AIS3+ thorax occupant protection in car-to-car nearside collisions need to and can be improved. The aim was fulfilled by means of real life data, for older cars without side airbag, and a series of car-to-car tests performed with the WorldSID 50%-ile in modern and older cars at different impact speeds.The real life data showed that the risk of AIS3+ injury was highest for the thorax followed by the pelvis and head. For both non-senior and senior occupants, most thorax injuries were sustained at lateral delta-v from 20 km/h to 40 km/h. In this severity range, senior occupants were found to have approximately four times higher risk of thoracic injury than non-senior occupants. The crash tests at lateral impact speed 55 km/h (delta-v 32 km/h) confirmed the improved performance at severities represented in current legal and rating tests. The structural integrity of the modern car impacted at 70 km/h showed a potential for improved side impact protection by interior countermeasures.

Reliability of a retrospective decade-based life-course alcohol consumption questionnaire administered in later life.

PubMed

Bell, Steven; Britton, Annie

2015-10-01

Retrospective measures of alcohol intake are becoming increasingly popular; however, the reliability of such measures remains uncertain. This study assessed the reliability of a retrospective decade-based life-course alcohol consumption questionnaire, based on the standardized Alcohol Use Disorder Identification Test-Consumption (AUDIT-C) administered in older age in a well-characterized cohort study. A retrospective alcohol life-grid was administered to 5980 participants (72% male, mean age 70 years) in the Whitehall II study covering frequency of drinking, number of drinks in a typical drinking day and frequency of consuming six or more drinks in a single drinking occasion in the teens (16-19 years) through to the 80s. A subsample of 385 individuals completed a repeat survey to determine test-retest reliability. Retrospective measures were also compared with prospectively ascertained information and used to predict objectively measured systolic blood pressure to test their predictive validity. Across all decades of life, test-retest reliability was generally good (κ range = 0.62-0.78 for frequency, 0.55-0.62 for usual number of drinks and 0.57-0.65 for frequency of consuming six or more drinks in a single occasion). The concordance between prospective and retrospective measures was consistently moderate to high. The life-grid method performed better than a single question in identifying life-time abstainers. Retrospective measures were also related to systolic blood pressure in the manner anticipated. A retrospective decade-based AUDIT-C grid administered in older age provides a relatively reliable measure of alcohol consumption across the life-course. © 2015 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of Addiction.

Two-step sensitivity testing of parametrized and regionalized life cycle assessments: methodology and case study.

PubMed

Mutel, Christopher L; de Baan, Laura; Hellweg, Stefanie

2013-06-04

Comprehensive sensitivity analysis is a significant tool to interpret and improve life cycle assessment (LCA) models, but is rarely performed. Sensitivity analysis will increase in importance as inventory databases become regionalized, increasing the number of system parameters, and parametrized, adding complexity through variables and nonlinear formulas. We propose and implement a new two-step approach to sensitivity analysis. First, we identify parameters with high global sensitivities for further examination and analysis with a screening step, the method of elementary effects. Second, the more computationally intensive contribution to variance test is used to quantify the relative importance of these parameters. The two-step sensitivity test is illustrated on a regionalized, nonlinear case study of the biodiversity impacts from land use of cocoa production, including a worldwide cocoa products trade model. Our simplified trade model can be used for transformable commodities where one is assessing market shares that vary over time. In the case study, the highly uncertain characterization factors for the Ivory Coast and Ghana contributed more than 50% of variance for almost all countries and years examined. The two-step sensitivity test allows for the interpretation, understanding, and improvement of large, complex, and nonlinear LCA systems.

Optimum selection of an implantable secondary battery for an artificial heart by examination of the cycle life test.

PubMed

Okamoto, Eiji; Watanabe, Kazuya; Hashiba, Kunihiro; Inoue, Taku; Iwazawa, Eichi; Momoi, Masato; Hashimoto, Takuya; Mitamura, Yoshinori

2002-01-01

An implantable secondary battery is one of the key components in a total artificial heart system. Because a 2 year cycle life is required, the cycle life of the secondary battery as well as its charge and discharge properties are important parameters for selection of an appropriate battery. We carried out cycle life tests on four kinds of rechargeable batteries (a Ni-MH secondary battery, a Ni-Cd secondary battery, a Li-ion battery with a graphite anode, and a Li-ion battery with a nongraphitizable carbon electrode) to determine their suitability as implanted back-up batteries. Each of the batteries was charge/discharge cycled at 37 degrees C to 39 degrees C using a charge current of 1 C ampere, and they were each fully discharged under either pulsatile discharge loads, which mimicked pulsatile operation, or a nonpulsatile load equivalent to the average of the pulsatile loads. The two Li-ion batteries made by different manufacturers both met the minimum requirement of cycle life of more than 1,500 cycles, considering safety coefficient regardless of the discharge pattern. In addition, the temperature increase of these Li-ion batteries (3 degrees C) was lower than that of Ni-Cd and Ni-MH batteries (15-25 degrees C). Out of these four batteries, the two Li-ion batteries are the most suitable for use in a totally implantable artificial heart system.

Cost and quality of life analysis of HIV self-testing and facility-based HIV testing and counselling in Blantyre, Malawi.

PubMed

Maheswaran, Hendramoorthy; Petrou, Stavros; MacPherson, Peter; Choko, Augustine T; Kumwenda, Felistas; Lalloo, David G; Clarke, Aileen; Corbett, Elizabeth L

2016-02-19

HIV self-testing (HIVST) has been found to be highly effective, but no cost analysis has been undertaken to guide the design of affordable and scalable implementation strategies. Consecutive HIV self-testers and facility-based testers were recruited from participants in a community cluster-randomised trial ( ISRCTN02004005 ) investigating the impact of offering HIVST in addition to facility-based HIV testing and counselling (HTC). Primary costing studies were undertaken of the HIVST service and of health facilities providing HTC to the trial population. Costs were adjusted to 2014 US$ and INT$. Recruited participants were asked about direct non-medical and indirect costs associated with accessing either modality of HIV testing, and additionally their health-related quality of life was measured using the EuroQol EQ-5D. A total of 1,241 participants underwent either HIVST (n = 775) or facility-based HTC (n = 446). The mean societal cost per participant tested through HIVST (US$9.23; 95 % CI: US$9.14-US$9.32) was lower than through facility-based HTC (US$11.84; 95 % CI: US$10.81-12.86). Although the mean health provider cost per participant tested through HIVST (US$8.78) was comparable to facility-based HTC (range: US$7.53-US$10.57), the associated mean direct non-medical and indirect cost was lower (US$2.93; 95 % CI: US$1.90-US$3.96). The mean health provider cost per HIV positive participant identified through HIVST was higher (US$97.50) than for health facilities (range: US$25.18-US$76.14), as was the mean cost per HIV positive individual assessed for anti-retroviral treatment (ART) eligibility and the mean cost per HIV positive individual initiated onto ART. In comparison to the facility-testing group, the adjusted mean EQ-5D utility score was 0.046 (95 % CI: 0.022-0.070) higher in the HIVST group. HIVST reduces the economic burden on clients, but is a costlier strategy for the health provider aiming to identify HIV positive individuals for treatment. The

The roles of men in family planning - a study of married men at the UKM primary care clinic.

PubMed

Ling, Jes; Tong, S F

2017-01-01

Traditionally, family planning initiatives were concentrated on women despite it being a family matter. As family dynamics evolved over the years, fathers' involvement in family planning has become crucial in enhancing the family well-being. This study aimed to identify the role played by men in family planning activities and the association of socio-economic characteristics with these roles. This was a cross-sectional study carried out in a university primary care clinic. All married male attendees to the clinic, aged 50 years and below, were approached to answer a set of self-administered questionnaires, asking for their involvement in family planning practices. The data were analysed using descriptive and inferential statistics. There were 167 participants in the study. A high proportion of men participated in the discussions regarding previous pregnancies (60.42%), future child planning (89.76%) and desired family size (89.76%). However, the discussions on the usage of family planning methods (FPMs; 39.16%) were significantly low. Socio-economic factors associated with higher likelihood of men discussing family planning activities were older age ( p < 0.0), higher education level ( p = 0.010), higher monthly income ( p < 0.001) and longer duration of marriage ( p = 0.0049). The level of participation of men varied in the discussions of four family planning activities. The roles taken by men in family planning were associated with older age and higher socio-economic class. The majority of men needs to be encouraged to play a more active role in the discussion of FPMs.

Social Connectedness and Life Satisfaction: Comparing Mean Levels for 2 Undergraduate Samples and Testing for Improvement Based on Brief Counseling

ERIC Educational Resources Information Center

Blau, Gary; DiMino, John; DeMaria, Peter A.; Beverly, Clyde; Chessler, Marcy; Drennan, Rob

2016-01-01

Objectives: Comparing the mean levels of social connectedness and life satisfaction, and analyzing their relationship for 2 undergraduate samples, and testing for an increase in their means for a brief counseling sample. Participants: Between October 2013 and May 2015, 3 samples were collected: not-in-counseling (NIC; n = 941), initial counseling…

Development of chronic tests for endocrine active chemicals. Part 1. An extended fish early-life stage test for oestrogenic active chemicals in the fathead minnow (Pimephales promelas).

PubMed

Panter, G H; Hutchinson, T H; Hurd, K S; Bamforth, J; Stanley, R D; Duffell, S; Hargreaves, A; Gimeno, S; Tyler, C R

2006-05-10

An extended early-life stage test (based on OECD test guideline 210) was developed to allow the evaluation of a weak environmental oestrogen, 4-tert-pentyphenol (4TPP), on sexual differentiation and gonadal development. Fathead minnow (Pimephales promelas) embryos were exposed to three concentrations of 4TPP (56, 180 and 560 microg l(-1)) in a flow-through system, at 25+/-1 degrees C, for <107 days post-hatch (dph). In addition, some embryos were exposed to 180 microg 4TPPl(-1) until 30 or 60 dph, after which they were exposed to dilution water only until 107 dph. At 30, 60 and 107 dph fish were evaluated for growth and gonadal development (via histology), and at 107 dph fish were also evaluated for secondary sexual characteristics (SSC), gonadosomatic index (GSI) and plasma vitellogenin (VTG). There were no effects of 4TPP on hatching success or survival, however, there was a delay in the time taken for embryos to hatch (560 microg 4TPPl(-1)). No treatment-related effects were observed on fish growth, with the exception of at 107 dph when the condition factor in female fish was reduced in all 4TPP continuous exposure treatments. Plasma VTG was only elevated in female fish exposed to 180 microg 4TPPl(-1) and inhibition of gonadal growth (GSI) occurred only in females exposed to 560 microg 4TPPl(-1). Histological examination of the gonads revealed delays and disruption in male sexual differentiation and development (180 microg 4TPPl(-1)) and no testicular tissue was observed in any fish exposed to 560 microg 4TPPl(-1). Mixed gonads (predominately testes with a scattering of primary oocytes) were present in fish exposed to all doses of 180 microg 4TPPl(-1) at 107 dph. Feminisation of the reproductive ducts (formation of an ovarian like cavity) occurred in the testis of all males exposed to 180 microg l(-1), regardless of length of 4TPP exposure. Results indicate that the period of 30-60 dph appears to be the sensitive window for disruption of formation of the

Development of chronic tests for endocrine active chemicals. Part 2: an extended fish early-life stage test with an androgenic chemical in the fathead minnow (Pimephales promelas).

PubMed

Bogers, Rinus; De Vries-Buitenweg, Selinda; Van Gils, Mariëlle; Baltussen, Erik; Hargreaves, Adam; van de Waart, Beppy; De Roode, Daphne; Legler, Juliette; Murk, Albertinka

2006-11-16

The Endocrine Modulators Study Group (EMSG) of the European Chemical Industry has proposed an extended fish early-life stage (ELS) test based on OECD test guideline 210 in combination with a fish pair-breeding reproduction study as a possible alternative for fish full life cycle testing. In this paper the androgen methyldihydrotestosterone (MDHT) was tested in an extended ELS test with fathead minnow supplementary to such a test with the weak estrogen 4-tert-pentylphenol (4TPP). Main endpoints were secondary sexual characteristics (SSC), plasma vitellogenin (VTG) induction and gonadal development. Early blastula embryos were exposed to 0, 0.10, 0.32 and 1.0 microgMDHTl(-1) for up to 114 days post-hatch (dph). A batch of fish exposed to 1.0 microg l(-1) was transferred to clean water after 30 or 63 dph for the remainder of the study. Ethinylestradiol (EE2) was included as estrogenic reference substance at 0.01 microg l(-1). Exposure to MDHT had no significant effect on hatching success or survival, but significantly increased the condition factor of fish exposed for 63 and 114 dph (up to 150% of the control). At 63 dph MDHT exposure induced appearance of tubercles on the snout (a male SSC) of more than 80% of fish. Compared to the controls, plasma VTG was not detectable or significantly lower in fish exposed to MDHT at 0.10 microg/l, but not significantly affected at higher MDHT concentrations. Both lower levels of MDHT significantly inhibited the development of female gonads as of 30 dph. Fish exposed to MDHT at 0.32 and 1.0 microg l(-1) showed higher incidences of mixed sex gonads (10-25%) and smaller testes or dysplasia of gonadal tissue. Dysplasia was present in 80% of the fish continuously exposed to 1.0 microg l(-1) up to 114 dph, but reversible when fish were transferred to dilution water. Results indicate that suppression of ovarian development was the most sensitive endpoint for MDHT exposure after 30 dph. Other endpoints (e.g., growth and SSC) required

Geometry of the q-exponential distribution with dependent competing risks and accelerated life testing

NASA Astrophysics Data System (ADS)

Zhang, Fode; Shi, Yimin; Wang, Ruibing

2017-02-01

In the information geometry suggested by Amari (1985) and Amari et al. (1987), a parametric statistical model can be regarded as a differentiable manifold with the parameter space as a coordinate system. Note that the q-exponential distribution plays an important role in Tsallis statistics (see Tsallis, 2009), this paper investigates the geometry of the q-exponential distribution with dependent competing risks and accelerated life testing (ALT). A copula function based on the q-exponential function, which can be considered as the generalized Gumbel copula, is discussed to illustrate the structure of the dependent random variable. Employing two iterative algorithms, simulation results are given to compare the performance of estimations and levels of association under different hybrid progressively censoring schemes (HPCSs).

Miniature Long-life Space Cryocoolers

NASA Technical Reports Server (NTRS)

Tward, E.

1993-01-01

TRW has designed, built, and tested a miniature integral Stirling cooler and a miniature pulse tube cooler intended for long-life space application. Both efficient, low-vibration coolers were developed for cooling IR sensors to temperatures as low as 50 K on lightsats. The vibrationally balanced nonwearing design Stirling cooler incorporates clearance seals maintained by flexure springs for both the compressor and the drive displacer. The design achieved its performance goal of 0.25 W at 65 K for an input power to the compressor of 12 W. The cooler recently passed launch vibration tests prior to its entry into an extended life test and its first scheduled flight in 1995. The vibrationally balanced, miniature pulse tube cooler intended for a 10-year long-life space application incorporates a flexure bearing compressor vibrationally balanced by a motor-controlled balancer and a completely passive pulse tube cold head.

Determination of life for a polyimide-epoxy alternator insulation system

NASA Technical Reports Server (NTRS)

Penn, W. B.; Schaefer, R. F.; Balke, R. L.

1974-01-01

Tests were conducted to predict remaining electrical insulation life of a polyimide epoxy insulated 60 KW, 208 volt homopolar inductor alternator, following completion of 23,130 hours of turbo-alternator endurance tests. The sectioned armature winding of this alternator stator was used as means to evaluate and measure end-life at several aging temperatures for development of an Arrhenius plot. A one-half life rate of 11.3 C was established from these data with a predicted remaining life of 60,000 hours at an armature winding temperature of 248 C and a total life, including endurance test time, of 61,645 hours.

Life sciences.

PubMed

Martin-Brennan, Cindy; Joshi, Jitendra

2003-12-01

Space life sciences research activities are reviewed for 2003. Many life sciences experiments were lost with the tragic loss of STS-107. Life sciences experiments continue to fly as small payloads to the International Space Station (ISS) via the Russian Progress vehicle. Health-related studies continue with the Martian Radiation Environment Experiment (MARIE) aboard the Odyssey spacecraft, collecting data on the radiation environment in Mars orbit. NASA Ames increased nanotechnology research in all areas, including fundamental biology, bioastronautics, life support systems, and homeland security. Plant research efforts continued at NASA Kennedy, testing candidate crops for ISS. Research included plant growth studies at different light intensities, varying carbon dioxide concentrations, and different growth media. Education and outreach efforts included development of a NASA/USDA program called Space Agriculture in the Classroom. Canada sponsored a project called Tomatosphere, with classrooms across North America exposing seeds to simulated Mars environment for growth studies. NASA's Office of Biological and Physical Research released an updated strategic research plan.

Shelf-life prediction models for ready-to-eat fresh cut salads: Testing in real cold chain.

PubMed

Tsironi, Theofania; Dermesonlouoglou, Efimia; Giannoglou, Marianna; Gogou, Eleni; Katsaros, George; Taoukis, Petros

2017-01-02

The aim of the study was to develop and test the applicability of predictive models for shelf-life estimation of ready-to-eat (RTE) fresh cut salads in realistic distribution temperature conditions in the food supply chain. A systematic kinetic study of quality loss of RTE mixed salad (lollo rosso lettuce-40%, lollo verde lettuce-45%, rocket-15%) packed under modified atmospheres (3% O 2 , 10% CO 2 , 87% N 2 ) was conducted. Microbial population (total viable count, Pseudomonas spp., lactic acid bacteria), vitamin C, colour and texture were the measured quality parameters. Kinetic models for these indices were developed to determine the quality loss and calculate product remaining shelf-life (SL R ). Storage experiments were conducted at isothermal (2.5-15°C) and non-isothermal temperature conditions (T eff =7.8°C defined as the constant temperature that results in the same quality value as the variable temperature distribution) for validation purposes. Pseudomonas dominated spoilage, followed by browning and chemical changes. The end of shelf-life correlated with a Pseudomonas spp. level of 8 log(cfu/g), and 20% loss of the initial vitamin C content. The effect of temperature on these quality parameters was expressed by the Arrhenius equation; activation energy (E a ) value was 69.1 and 122.6kJ/mol for Pseudomonas spp. growth and vitamin C loss rates, respectively. Shelf-life prediction models were also validated in real cold chain conditions (including the stages of transport to and storage at retail distribution center, transport to and display at 7 retail stores, transport to and storage in domestic refrigerators). The quality level and SL R estimated after 2-3days of domestic storage (time of consumption) ranged between 1 and 8days at 4°C and was predicted within satisfactory statistical error by the kinetic models. T eff in the cold chain ranged between 3.7 and 8.3°C. Using the validated models, SL R of RTE fresh cut salad can be estimated at any point of

When Does Money Matter Most? Examining the Association between Income and Life Satisfaction over the Life Course

PubMed Central

Cheung, Felix; Lucas, Richard E.

2015-01-01

Previous research shows that the correlation between income and life satisfaction is small to medium in size. We hypothesized that income may mean different things to people at different ages, and therefore, that the association between income and life satisfaction may vary at different points in the life course. We tested this hypothesis in three nationally representative panel studies. Multilevel modeling techniques were used to test whether age moderated both the within- and between-person associations. Consistent with past research, we found that individuals who earned more on average and individuals who earned more over time reported higher levels of life satisfaction. Importantly, these effects were strongest for midlife individuals (those in their 30s–50s) compared to individuals who were younger or older. PMID:25621741

[Sexual and reproductive health in university students at an institution of higher learning in Colombia].

PubMed

Gómez-Camargo, Doris E; Ochoa-Diaz, Margarita M; Canchila-Barrios, Carlos A; Ramos-Clason, Enrique C; Salguedo-Madrid, Germán I; Malambo-García, Dacia I

2014-01-01

To investigate the state of sexual and reproductive health in students at a public university in the Colombian Caribbean, with an emphasis on sexually transmitted diseases (STDs), fertility, sexuality, pregnancy and violence. Cross-sectional survey study. University students, enrolled in the second semester of 2010 and who completed a self-administered survey based on the Reproductive Health survey of the Pan American Health Organization, were selected. Qualitative data was tabulated and graphed using measures of central tendency for quantitative variables. The age of population studied was around 20 years old, came from the urban area (57.9 %; IC95 %=54.7-61.1), was predominantly heterosexual (89.7 %), with an age of initiation of sexual activity of less than 18 years old, 11.8 % promiscuity, mainly using the condom as a Family Planning Method (FPM) (55 %). Although they had prior information on sexual health, STDs and FPMs, they did not behave according to this due to low education about HIV transmission routes, low incidence of serological tests for STDs, and high risk behavior (sex/alcohol/drugs). It was observed that 12.3 % had a history of pregnancy, physical violence (21.6 %) and sexual violence (4.6 %) with a predominant silence from the victims of sexual abuse (61.8 %). The sample reflects the student population in this region of Colombia. We plan to organize a health program with medical and psychological support to reduce the rates of STDs and unplanned pregnancies, preparing the adolescent for this important step in their life and serving as a model for other Latin American universities.

Effect of Group Positive Psychotherapy on Improvement of Life Satisfaction and The Quality of Life in Infertile Woman.

PubMed

Seyedi Asl, Seyed Teymur; Sadeghi, Kheirollah; Bakhtiari, Mitra; Ahmadi, Seyed Mojtaba; Nazari Anamagh, Alireza; Khayatan, Tayebeh

2016-01-01

Positive psychotherapy is one of the new approaches in psychology which is innovated for treating psychological disorders and enhancing positive emotions. The aim of this study is to investigate the effectiveness of the group positive psychotherapy on elevation of life satisfaction and quality of life in infertile women. In a randomized trial study, Beck Depression Inventory II (BDI-II) and clinical interview were used in a pre-test post-test control group design. After analyzing the result of the questionnaire, 36 infertile women who showed signs of mild to moderate depression were randomly placed into two following groups: control (n=18) and intervention (n=18). Before the treatment, the members of both groups answered BDI-II, Satisfaction With Life Scale (SWLS) and 12 item Short Form Health Survey (SF-12). The intervention group received six sessions of group positive psychotherapy, but the treatment of the control group began six weeks after the intervention group. The results showed that the life satisfaction scores of the intervention group were significantly elevated from 22.66 in pre-test to 26.13 in post-test (P<0.001), while this improvement was not significant in the control group (P=0.405). The difference between life satisfaction scores of the intervention and the control groups was also significant (F=8.92, P=0.006). However, no significant change in the quality of life level of the intervention and control groups was observed (P=0.136). Thus it can be deduced from the findings that this treatment method could be introduced as solution to increase the life satisfaction in infertile women, but not as a treatment for elevating their quality of life (Registration Number: IRCT2013042810063N3).

[Relationships between suicide attitudes and perception of life purpose and meaning of life in college students].

PubMed

Xie, Xingli; Zou, Bing; Huang, Zhongyan

2012-10-01

To investigate the suicide attitudes of college students and analyze the impact of the perception of life purpose and meaning of life on their suicide attitudes using structural equation modeling. A total of 1050 college students were tested by Suicide Attitude Questionnaire (QSA), Purpose in Life test (PIL) and Chinese version of Meaning of Life questionnaire (C-MLQ). A theoretical model was established for confirming the influence of the purpose in life and meaning in life on suicide attitudes of the college students. The college students had generally a negative attitude towards suicide. The female students tended to show more objective attitudes towards suicide and the students from rural areas had a stronger attitude against euthanasia.The meanings and purposes in life were closely correlated with the attitudes towards suicide, and the structural equation modeling well fitted the data (Χ(2)/df=1.924, GFI=0.936, AGFI=0.915, NFI=0.937, CFI=0.940, and RMSEA=0.045). The perception of meaning and purposes in life had a direct predictive value on the suicide attitude of the college students, and the presumptions derived from the theoretical model were strongly supported by structural equation modeling. The perceptions in meanings in life and purposes in livelihood have important influence on the suicide attitudes of college students, and intervention with effective life education should be administered to guide the suicide attitude of the college students.

Thoracic Injury Risk as a Function of Crash Severity – Car-to-car Side Impact Tests with WorldSID Compared to Real-life Crashes

PubMed Central

Sunnevång, Cecilia; Rosén, Erik; Boström, Ola; Lechelt, Ulf

2010-01-01

Side airbags reduce the risk of fatal injury by approximately 30%. Due to limited real-life data the risk reducing effect for serious injury has not yet been established. Since side airbags are mainly designed and validated for crash severities used in available test procedures little is known regarding the protective effect when severity increases. The objective of this study was to understand for which crash severities AIS3+ thorax occupant protection in car-to-car nearside collisions need to and can be improved. The aim was fulfilled by means of real life data, for older cars without side airbag, and a series of car-to-car tests performed with the WorldSID 50%-ile in modern and older cars at different impact speeds. The real life data showed that the risk of AIS3+ injury was highest for the thorax followed by the pelvis and head. For both non-senior and senior occupants, most thorax injuries were sustained at lateral delta-v from 20 km/h to 40 km/h. In this severity range, senior occupants were found to have approximately four times higher risk of thoracic injury than non-senior occupants. The crash tests at lateral impact speed 55 km/h (delta-v 32 km/h) confirmed the improved performance at severities represented in current legal and rating tests. The structural integrity of the modern car impacted at 70 km/h showed a potential for improved side impact protection by interior countermeasures. PMID:21050600

Fatigue Life Methodology for Bonded Composite Skin/Stringer Configurations

NASA Technical Reports Server (NTRS)

Krueger, Ronald; Paris, Isabelle L.; OBrien, T. Kevin; Minguet, Pierre J.

2001-01-01

A methodology is presented for determining the fatigue life of composite structures based on fatigue characterization data and geometric nonlinear finite element (FE) analyses. To demonstrate the approach, predicted results were compared to fatigue tests performed on specimens which represented a tapered composite flange bonded onto a composite skin. In a first step, tension tests were performed to evaluate the debonding mechanisms between the flange and the skin. In a second step, a 2D FE model was developed to analyze the tests. To predict matrix cracking onset, the relationship between the tension load and the maximum principal stresses transverse to the fiber direction was determined through FE analysis. Transverse tension fatigue life data were used to -enerate an onset fatigue life P-N curve for matrix cracking. The resulting prediction was in good agreement with data from the fatigue tests. In a third step, a fracture mechanics approach based on FE analysis was used to determine the relationship between the tension load and the critical energy release rate. Mixed mode energy release rate fatigue life data were used to create a fatigue life onset G-N curve for delamination. The resulting prediction was in good agreement with data from the fatigue tests. Further, the prediction curve for cumulative life to failure was generated from the previous onset fatigue life curves. The results showed that the methodology offers a significant potential to Predict cumulative fatigue life of composite structures.

Gene expression analysis in zebrafish embryos: a potential approach to predict effect concentrations in the fish early life stage test.

PubMed

Weil, Mirco; Scholz, Stefan; Zimmer, Michaela; Sacher, Frank; Duis, Karen

2009-09-01

Based on the hypothesis that analysis of gene expression could be used to predict chronic fish toxicity, the zebrafish (Danio rerio) embryo test (DarT), developed as a replacement method for the acute fish test, was expanded to a gene expression D. rerio embryo test (Gene-DarT). The effects of 14 substances on lethal and sublethal endpoints of the DarT and on expression of potential marker genes were investigated: the aryl hydrocarbon receptor 2, cytochrome P450 1A (cypla), heat shock protein 70, fizzy-related protein 1, the transcription factors v-maf musculoaponeurotic fibrosarcoma oncogene family protein g (avian) 1 and NF-E2-p45-related factor, and heme oxygenase 1 (hmox1). After exposure of zebrafish embryos for 48 h, differential gene expression was evaluated using reverse transcriptase-polymerase chain reaction, gel electrophoresis, and densitometric analysis of the gels. All tested compounds significantly affected the expression of at least one potential marker gene, with cyp1a and hmox1 being most sensitive. Lowest-observed-effect concentrations (LOECs) for gene expression were below concentrations resulting in 10% lethal effects in the DarT. For 10 (3,4- and 3,5-dichloroaniline, 1,4-dichlorobenzene, 2,4-dinitrophenol, atrazine, parathion-ethyl, chlorotoluron, genistein, 4-nitroquinoline-1-oxide, and cadmium) out of the 14 tested substances, LOEC values derived with the Gene-DarT differ by a factor of less than 10 from LOEC values of fish early life stage tests with zebrafish. For pentachloroaniline and pentachlorobenzene, the Gene-DarT showed a 23- and 153-fold higher sensitivity, respectively, while for lindane, it showed a 13-fold lower sensitivity. For ivermectin, the Gene-DarT was by a factor of more than 1,000 less sensitive than the acute fish test. The results of the present study indicate that gene expression analysis in zebrafish embryos could principally be used to predict effect concentrations in the fish early life stage test.

Solid Propulsion Systems, Subsystems, and Components Service Life Extension

NASA Technical Reports Server (NTRS)

Hundley, Nedra H.; Jones, Connor

2011-01-01

The service life extension of solid propulsion systems, subsystems, and components will be discussed based on the service life extension of the Space Transportation System Reusable Solid Rocket Motor (RSRM) and Booster Separation Motors (BSM). The RSRM is certified for an age life of five years. In the aftermath of the Columbia accident there were a number of motors that were approaching the end of their five year service life certification. The RSRM Project initiated an assessment to determine if the service life of these motors could be extended. With the advent of the Constellation Program, a flight test was proposed that would utilize one of the RSRMs which had been returned from the launch site due to the expiration of its five year service life certification and twelve surplus Chemical Systems Division BSMs which had exceeded their eight year service life. The RSRM age life tracking philosophy which establishes when the clock starts for age life tracking will be described. The role of the following activities in service life extension will be discussed: subscale testing, accelerated aging, dissecting full scale aged hardware, static testing full scale aged motors, data mining industry data, and using the fleet leader approach. The service life certification and extension of the BSMs will also be presented.

Computer Software for Life Cycle Cost.

DTIC Science & Technology

1987-04-01

34 111. 1111I .25 IL4 jj 16 MICROCOPY RESOLUTION TEST CHART hut FILE C AIR CoMMNAMN STFF COLLG STUJDET PORTO i COMpUTER SOFTWARE FOR LIFE CYCLE CO879...obsolete), physical life (utility before physically wearing out), or application life (utility in a given function)." (7:5) The costs are usually

Cross-cultural development of a quality-of-life measure for patients with melanoma: phase 3 testing of an EORTC Melanoma Module.

PubMed

Winstanley, Julie B; Young, Teresa E; Boyle, Frances M; Bergenmar, Mia; Bottomley, Andrew; Burmeister, Bryan; Campana, Luca G; Garioch, Jennifer J; King, Madeleine; Nikolic, Dejan V; van de Poll-Franse, Lonneke V; Saw, Robyn; Thompson, John F; White, Edward G

2015-02-01

Melanoma is an increasingly common skin cancer worldwide. Recent treatment advances have provided patients and healthcare professionals (HCPs) with choices where quality of life (QoL) and toxicity are important considerations. A melanoma-specific QoL questionnaire is being developed in a cross-cultural setting using a four phase process developed by the European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Group. In phase 1, a literature search identified a list of pertinent QoL issues; this was shown to HCPs and patients in eight countries and rated for importance and relevance. Questions were constructed for the highest-rated issues (phase 2) and piloted in another patient sample (phase 3). Using EORTC Quality of Life Group criteria and sequential use of factor and Rasch analysis, scales were hypothesized for field testing (phase 4). Seven QoL domains (disease symptoms, treatment issues, financial issues, access/quality of information, satisfaction with care, psychosocial issues and support), comprising 73 QoL issues, were rated by 46 HCPs and 78 patients. Fifty-six issues were rephrased as questions and piloted with 132 patients. A 38-item questionnaire (QLQ-MEL38) is available for field testing in conjunction with the EORTC QLQ-C30. This study has shown that melanoma patients have important QoL issues that have been incorporated into a new cross-culturally validated instrument. Future testing of this EORTC module is planned and will be an important step forward in providing reliable QoL data to aid future decision-making in the management and clinical trials of this complex group of patients.

[Validity evidence of the Health-Related Quality of Life for Drug Abusers Test based on the Biaxial Model of Addiction].

PubMed

Lozano, Oscar M; Rojas, Antonio J; Pérez, Cristino; González-Sáiz, Francisco; Ballesta, Rosario; Izaskun, Bilbao

2008-05-01

The aim of this work is to show evidence of the validity of the Health-Related Quality of Life for Drug Abusers Test (HRQoLDA Test). This test was developed to measure specific HRQoL for drugs abusers, within the theoretical addiction framework of the biaxial model. The sample comprised 138 patients diagnosed with opiate drug dependence. In this study, the following constructs and variables of the biaxial model were measured: severity of dependence, physical health status, psychological adjustment and substance consumption. Results indicate that the HRQoLDA Test scores are related to dependency and consumption-related problems. Multiple regression analysis reveals that HRQoL can be predicted from drug dependence, physical health status and psychological adjustment. These results contribute empirical evidence of the theoretical relationships established between HRQoL and the biaxial model, and they support the interpretation of the HRQoLDA Test to measure HRQoL in drug abusers, thus providing a test to measure this specific construct in this population.

The effects of lacosamide on cognition, quality-of-life measures, and quality of life in patients with refractory partial epilepsy.

PubMed

Lancman, Marcelo E; Fertig, Evan J; Trobliger, Robert W; Perrine, Kenneth; Myers, Lorna; Iyengar, Sloka S; Malik, Munazza

2016-08-01

The objective of this study was to examine cognitive and quality-of-life measures/quality of life outcomes with adjunctive lacosamide therapy in patients with treatment-resistant partial epilepsy. This was a prospective, open-label, nonblinded, adjunctive therapy test-retest (within subjects) study of patients with treatment-resistant partial epilepsy in which outcome (cognitive functioning and mood/quality of life) was measured in the same subject before and after adjunctive lacosamide administration for 24weeks. The cognitive assessment included the following: Controlled Oral Word Association Test, Buschke Selective Reminding Test, Brief Visuospatial Memory Test-Revised, Stroop Color Word Test, Symbol Digit Modalities Test, Digit Span, Digit Cancellation, and Trails A and B. The quality-of-life measures/quality-of-life assessment included the following: Beck Depression Inventory-II, Profile of Mood States, and Quality of Life Inventory-89. Lacosamide was started at 100mg (50mg twice daily) and could be titrated as needed up to 400mg/day (200mg twice daily). Baseline concomitant AEDs were kept constant. Composite scores were calculated for a pre-post difference score for the cognitive and mood/quality-of-life measures separately and used in regression analyses to correct for the effects of age, education, seizure frequency, seizure severity, dose of lacosamide, and number of AEDs at baseline. Thirty-four patients were enrolled (13 males, 21 females). Mean age was 38.8±2.43years. Mean seizure frequency decreased significantly from 2.0±2.55 seizures per week at baseline to 1.02±1.72 seizures per week at posttreatment (t=4.59, p<.0001) with a 50% responder rate seen in 18 patients (52.9%). No significant differences were found on the composite scores of the cognitive or the mood/quality-of-life measures after 6months of lacosamide. Lacosamide appeared to have low risks of significant changes in cognition or mood/quality of life. In addition, the present study

Assessing variability in chemical acute toxicity of unionid mussels: Influence of intra- and inter-laboratory testing, life stage, and species - SETAC Abstract

EPA Science Inventory

We developed a toxicity database for unionid mussels to examine the extent of intra- and inter-laboratory variability in acute toxicity tests with mussel larvae (glochidia) and juveniles; the extent of differential sensitivity of the two life stages; and the variation in sensitiv...

Effects of surface chemistry on hot corrosion life

NASA Technical Reports Server (NTRS)

Fryxell, R. E.; Leese, G. E.

1985-01-01

This program has its primary objective: the development of hot corrosion life prediction methodology based on a combination of laboratory test data and evaluation of field service turbine components which show evidence of hot corrosion. The laboratory program comprises burner rig testing by TRW. A summary of results is given for two series of burner rig tests. The life prediction methodology parameters to be appraised in a final campaign of burner rig tests are outlined.

Life sciences flight experiments program, life sciences project division, procurement quality provisions

NASA Technical Reports Server (NTRS)

House, G.

1980-01-01

Methods are defined for implementing quality assurance policy and requirements for life sciences laboratory equipment, experimental hardware, integration and test support equipment, and integrated payloads.

Robotic Astrobiology: Searching for Life with Rovers

NASA Astrophysics Data System (ADS)

Cabrol, N. A.; Wettergreen, D. S.; Team, L.

2006-05-01

The Life In The Atacama (LITA) project has developed and field tested a long-range, solar-powered, automated rover platform (Zoe) and a science payload assembled to search for microbial life in the Atacama desert. Life is hardly detectable over most of the extent of the driest desert on Earth. Its geological, climatic, and biological evolution provides a unique training ground for designing and testing exploration strategies and life detection methods for the robotic search for life on Mars. LITA opens the path to a new generation of rover missions that will transition from the current study of habitability (MER) to the upcoming search for, and study of, habitats and life on Mars. Zoe's science payload reflects this transition by combining complementary elements, some directed towards the remote sensing of the environment (geology, morphology, mineralogy, weather/climate) for the detection of conditions favorable to microbial habitats and oases along survey traverses, others directed toward the in situ detection of life' signatures (biological and physical, such as biological constructs and patterns). New exploration strategies specifically adapted to the search for microbial life were designed and successfully tested in the Atacama between 2003-2005. They required the development and implementation in the field of new technological capabilities, including navigation beyond the horizon, obstacle avoidance, and "science-on-the-fly" (automated detection of targets of science value), and that of new rover planning tools in the remote science operation center.

Effects of test design and temperature in a partial life-cycle study with the freshwater gastropod Potamopyrgus antipodarum.

PubMed

Macken, Ailbhe; Le Page, Gareth; Hayfield, Amanda; Williams, Timothy D; Brown, Rebecca J

2012-09-01

Potamopyrgus antipodarum is a candidate for a standardized mollusk partial life-cycle study. This is a comparative study of two test designs (microplate and beaker), with additional endpoints to the proposed guideline methods, for example, tracking of continuous reproductive output over 28 d and attributing it to individual female snails. In addition, an investigation of the effects of temperature (16, 20, and 25°C) on reproduction was also conducted employing the microplate design. Copyright © 2012 SETAC.

Structural changes and damage of single-crystal turbine blades during life tests of an aviation gas turbine engine

NASA Astrophysics Data System (ADS)

Ospennikova, O. G.; Orlov, M. R.; Kolodochkina, V. G.; Nazarkin, R. M.

2015-04-01

The irreversible structural changes of the single-crystal ZhS32-VI nickel superalloy blades of a high-pressure turbine that occur during life tests of a gas turbine engine are studied. The main operation damages in the hottest section of the blade airfoil are found to be the fracture of the heat-resistant coating in the leading edge and the formation of thermomechanical fatigue cracks. The possibility of reconditioning repair of the blades is considered.

A Battery Test to Evaluate Life-Time Physical Fitness With Same Test Items.

ERIC Educational Resources Information Center

Meshizuka, Tetsuo

A combination of physical fitness tests designed to be administered to a wide spectrum of the population, male and female, children and adults, is described. Three tests are included in this battery--motor fitness, physical fitness, and sports fitness. The philosophy behind this test structure is that motor fitness tests only measure and indicate…

Effects of early life factors on the health and quality of life of older adults.

PubMed

Yilmaz, Fikriye; N Tekin, Rukiye

2018-01-01

Few studies on the effects of early life factors on the health and quality of life of adults have been conducted in Turkey. We aimed to investigate the effects of early life factors on the health and quality of life of older adults. We administered a questionnaire to 350 adults, aged 50-89 years, living in Cankaya, Ankara. The questionnaire covered sociodemographic characteristics, early life characteristics, health status, and the World Health Organization Quality of Life-Ageing scale. Data were analyzed using χ 2 tests, independent samples t-tests, one-way anova, and binary logistic regression analysis. The analyses showed that the most important risk factors for chronic disease were being ≥65 years (odds ratio (OR) = 2.34), having a chronic health problem before 18 years of age (OR = 2.48), experiencing prolonged hospitalization or bed rest before 18 years of age (OR = 2.65), and experiencing parental unconcern during early life (OR = 2.13) (P < 0.05). In addition, having a high school education or less includes people who have primary or secondary or high school diploma (OR = 1.65), having lived in a village (OR = 1.65), having a low family economic status (OR = 2.40), and having experienced one negative event (OR = 1.41) or two or more negative events (OR = 1.39) during their early lives were identified as important risk factors for low quality of life (P < 0.05). Early life factors are among the important determinants of the health and quality of life of older adults in Turkey. © 2017 Japanese Psychogeriatric Society.

A toxicity test in artificial soil based on the life-history strategy of the nematode Plectus acuminatus

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

Kammenga, J.E.; Van Koert, P.H.G.; Riksen, J.A.G.

1996-05-01

The ecological risk assessment of toxicants in soil requires reproducible and relevant test systems using a wide range of species. To supplement present test methods from the Organisation of Economic Cooperation and Development (OECD) in artificial soil with earthworms and springtails, a toxicity test in OECD artificial soil has been developed using the bacterivorous nematode Plectus acuminatus (Bastian, 1865) (Nematoda; Plectidae). The juvenile to adult ratio was used as a test parameter since previous life-cycle studies pointed out that fitness of P. acuminatus was strongly determined by changes in both reproduction and juvenile survival. Optimal conditions for the performance ofmore » nematodes in OECD artificial soil were determined (pH{sub KCl} = 5.5, temperature = 20C, and a moisture content of 70% dry wt. artificial soil), and tests were conducted with cadmium, copper, and pentachlorophenol. After an exposure period of 3 weeks the EC50 for cadmium was 321.0 {+-} 1.7 mg/kg dry wt., and the no-observed-effect concentration (NOEC) was 32 mg/kg dry wt. The EC50 for pentachlorophenol was 47.9 {+-} 1.2 mg/kg dry wt., and the NOEC was <10 mg/kg dry wt. For copper the EC50 was 162 {+-} 0.2 mg/kg dry wt., and the NOEC was 32 mg/kg dry wt. It is concluded that the nematode test may well supplement current coil test systems using earthworms and springtails.« less

Battery Calendar Life Estimator Manual Modeling and Simulation

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

Jon P. Christophersen; Ira Bloom; Ed Thomas

2012-10-01

The Battery Life Estimator (BLE) Manual has been prepared to assist developers in their efforts to estimate the calendar life of advanced batteries for automotive applications. Testing requirements and procedures are defined by the various manuals previously published under the United States Advanced Battery Consortium (USABC). The purpose of this manual is to describe and standardize a method for estimating calendar life based on statistical models and degradation data acquired from typical USABC battery testing.

Battery Life Estimator Manual Linear Modeling and Simulation

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

Jon P. Christophersen; Ira Bloom; Ed Thomas

2009-08-01

The Battery Life Estimator (BLE) Manual has been prepared to assist developers in their efforts to estimate the calendar life of advanced batteries for automotive applications. Testing requirements and procedures are defined by the various manuals previously published under the United States Advanced Battery Consortium (USABC). The purpose of this manual is to describe and standardize a method for estimating calendar life based on statistical models and degradation data acquired from typical USABC battery testing.

Spousal Similarity in Life Satisfaction before and after Divorce

PubMed Central

Wortman, Jessica; Lucas, Richard E.

2015-01-01

Previous research has explored possible origins of individual differences in subjective well-being, focusing largely on stable, internal characteristics of traits as predictors of life satisfaction (Diener & Lucas, 1999). Although past work has demonstrated that life satisfaction is largely stable over the life span, other evidence has also demonstrated the lasting impact of life events. In this study, we use married couples as a test of the impact of life circumstances on life satisfaction, focusing on similarity in life satisfaction before and after divorce. If life satisfaction is impacted by shared life circumstances, married couples (who share life circumstances) should show greater similarity in life satisfaction before divorce than after. We tested this possibility using a dyadic latent-state-trait model that examined cross-spouse similarity in the stable and changing components of life satisfaction. Using a nationally representative panel study from Germany (Wagner, Frick & Schupp, 2007), we showed that similarity declined substantially following divorce. This suggests that life satisfaction is related to shared life circumstances. PMID:26436842

Spousal similarity in life satisfaction before and after divorce.

PubMed

Wortman, Jessica; Lucas, Richard E

2016-04-01

Previous research has explored possible origins of individual differences in subjective well-being, focusing largely on stable, internal characteristics of traits as predictors of life satisfaction (Diener & Lucas, 1999). Although past work has demonstrated that life satisfaction is largely stable over the life span, other evidence has also demonstrated the lasting impact of life events. In this study, we use married couples as a test of the impact of life circumstances on life satisfaction, focusing on similarity in life satisfaction before and after divorce. If life satisfaction is impacted by shared life circumstances, married couples (who share life circumstances) should show greater similarity in life satisfaction before divorce than after. We tested this possibility using a dyadic latent-state-trait model that examined cross-spouse similarity in the stable and changing components of life satisfaction. Using a nationally representative panel study from Germany (Wagner, Frick & Schupp, 2007), we showed that similarity declined substantially following divorce. This suggests that life satisfaction is related to shared life circumstances. (c) 2016 APA, all rights reserved).

International Space Station Environmental Control and Life Support System Acceptance Testing for Node 1 Atmosphere Control and Supply Subsystem

NASA Technical Reports Server (NTRS)

Williams, David E.

2009-01-01

The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Supply (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper provides a summary of the Node 1 ECLS ACS subsystem design and a detailed discussion of the ISS ECLS Acceptance Testing methodology utilized for that subsystem.

Rolling-element fatigue life with two synthetic cycloaliphatic traction fluids

NASA Technical Reports Server (NTRS)

Loewenthal, S. H.; Parker, R. J.

1976-01-01

The life potential of two synthetic cycloaliphatic hydrocarbon traction fluids in rolling element fatigue was evaluated in a five ball fatigue tester. Life comparisons with a MIL-L-23699 qualified tetraester oil showed that the traction test oils had good fatigue life performance, comparable to that of the tetraester oil. No statistically significant life differences between the traction fluids and the tetraester oil were exhibited under the accelerated fatigue test conditions. Erratic operating behavior was occasionally encountered during tests with the antiwear additive containing traction fluid for reasons thought to be related to excessive chemical activity under high contact pressure. This behavior occasionally resulted in premature test termination due to excessive surface distress and overheating.

Early-life disruption of amphibian microbiota decreases later-life resistance to parasites.

PubMed

Knutie, Sarah A; Wilkinson, Christina L; Kohl, Kevin D; Rohr, Jason R

2017-07-20

Changes in the early-life microbiota of hosts might affect infectious disease risk throughout life, if such disruptions during formative times alter immune system development. Here, we test whether an early-life disruption of host-associated microbiota affects later-life resistance to infections by manipulating the microbiota of tadpoles and challenging them with parasitic gut worms as adults. We find that tadpole bacterial diversity is negatively correlated with parasite establishment in adult frogs: adult frogs that had reduced bacterial diversity as tadpoles have three times more worms than adults without their microbiota manipulated as tadpoles. In contrast, adult bacterial diversity during parasite exposure is not correlated with parasite establishment in adult frogs. Thus, in this experimental setup, an early-life disruption of the microbiota has lasting reductions on host resistance to infections, which is possibly mediated by its effects on immune system development. Our results support the idea that preventing early-life disruption of host-associated microbiota might confer protection against diseases later in life.Early-life microbiota alterations can affect infection susceptibility later in life, in animal models. Here, Knutie et al. show that manipulating the microbiota of tadpoles leads to increased susceptibility to parasitic infection in adult frogs, in the absence of substantial changes in the adults' microbiota.

A Guide to Understanding Security Testing and Test Documentation in Trusted Systems, Version 1

DTIC Science & Technology

1993-07-01

necessary to allow the testing of access with all other types of objects. The above test data also provide partial coverage because they de not include...two types of assurance are needed. They are life-cycle assurance and operational assurance. "Life-cycle assurance refers to steps taken by an...procedures depends to a certain extent on the nature of the TCB interface under test. For example, for most TCB-primitive tests that require the same type

A comparison of fatigue life prediction methodologies for rotorcraft

NASA Technical Reports Server (NTRS)

Everett, R. A., Jr.

1990-01-01

Because of the current U.S. Army requirement that all new rotorcraft be designed to a 'six nines' reliability on fatigue life, this study was undertaken to assess the accuracy of the current safe life philosophy using the nominal stress Palmgrem-Miner linear cumulative damage rule to predict the fatigue life of rotorcraft dynamic components. It has been shown that this methodology can predict fatigue lives that differ from test lives by more than two orders of magnitude. A further objective of this work was to compare the accuracy of this methodology to another safe life method called the local strain approach as well as to a method which predicts fatigue life based solely on crack growth data. Spectrum fatigue tests were run on notched (k(sub t) = 3.2) specimens made of 4340 steel using the Felix/28 tests fairly well, being slightly on the unconservative side of the test data. The crack growth method, which is based on 'small crack' crack growth data and a crack-closure model, also predicted the fatigue lives very well with the predicted lives being slightly longer that the mean test lives but within the experimental scatter band. The crack growth model was also able to predict the change in test lives produced by the rainflow reconstructed spectra.

Accelerated life assessment of coating on the radar structure components in coastal environment.

PubMed

Liu, Zhe; Ming, ZhiMao

2016-07-04

This paper aimed to build an accelerated life test scheme and carry out quantitative analysis between accelerated life test in the laboratory and actual service for the coating composed of epoxy primer and polyurethane paint on structure components of some kind of radar served in the coastal environment of South China Sea. The accelerated life test scheme was built based on the service environment and failure analysis of the coating. The quantitative analysis between accelerated life test and actual service was conducted by comparing the gloss loss, discoloration, chalking, blistering, cracking and electrochemical impedance spectroscopy of the coating. The main factors leading to the coating failure were ultraviolet radiation, temperature, moisture, salt fog and loads, the accelerated life test included ultraviolet radiation, damp heat, thermal shock, fatigue and salt spray. The quantitative relationship was that one cycle of the accelerated life test was equal to actual service for one year. It was established that one cycle of the accelerated life test was equal to actual service for one year. It provided a precise way to predict actual service life of newly developed coatings for the manufacturer.

Long life assurance study for manned spacecraft long life hardware. Volume 1: Summary of long life assurance guidelines

NASA Technical Reports Server (NTRS)

1972-01-01

A long life assurance program for the development of design, process, test, and application guidelines for achieving reliable spacecraft hardware was conducted. The study approach consisted of a review of technical data performed concurrently with a survey of the aerospace industry. The data reviewed included design and operating characteristics, failure histories and solutions, and similar documents. The topics covered by the guidelines are reported. It is concluded that long life hardware is achieved through meticulous attention to many details and no simple set of rules can suffice.

Proper Installation Improves Carpet Life.

ERIC Educational Resources Information Center

Grogan, Ralph

1998-01-01

Explains how proper carpet installation can add to carpet life; includes tips to consider before signing a carpet-installation purchasing agreement that can make the new carpet a better investment. Topics cover how color selection lengthens appearance life, the need for moisture testing, the importance of carpet seams in the purchasing process,…

[Size of testes and epididymes in boys up to 17 years of life assessed by ultrasound method and method of external linear measurements].

PubMed

Osemlak, Paweł

2011-01-01

1. Determination of the size of testes and epididymes on the right and left side, in healthy boys in various age groups with use of non-invasive ultrasound examination method and the method of external linear measurements. 2. Determination of age, when intensive growth of testicular and epididymal size starts. 3. Determination whether there are statistically significant differences between the size of the right and the left testis, as well as between the right and left epididymis. 4. Evaluation of the ultrasound method and method of external linear measurements in their use for scientific investigations. 309 boys, aged from 1 day to 17 years of life, treated in the Clinical Department of Paediatric Surgery and Traumatology of the Medical University in Lublin from 2009 to 2010 due to diseases needed to be treated surgically, but not the scrotum, were examined in this study. No pathologies influencing the development of genital organs were found in these boys. Dimension of the testes was studied with ultrasound method and with method of external linear measurements. Dimension of epididymes was only examined with ultrasound method. In every age group the author calculated mean arithmetical values for: testiscular length, thickness, width and volume, as well as epididymal depth and basis. With consideration of standard deviation (X+/-1 SD) it was possible to define the range of dimension of healthy testes and epididymes and their change with age. Final dimensions of the right and left testis as well as of the right and left epididymis were compared. Dimensions of the testis on the same side of body acquired with the ultrasound method and acquired with the method of external linear measurements were compared. Statistical work-up with Wilcoxon test for two dependent groups was implemented. Ultrasound evaluation pointed to intensive 2.5-times increase in testicular length and width, and 2-times increase in testicular thickness in boys aged 10 to 17 years. Mean volume of

Life Testing of the Vapor Compression Distillation/Urine Processing Assembly (VCD/UPA) at the Marshall Space Flight Center (1993 to 1997)

NASA Technical Reports Server (NTRS)

Wieland, P.; Hutchens, C.; Long, D.; Salyer, B.

1998-01-01

Wastewater and urine generated on the International Space Station will be processed to recover pure water using vapor compression distillation (VCD). To verify the long-term reliability and performance of the VCD Urine Processor Assembly (UPA), life testing was performed at the Marshall Space Flight Center (MSFC) from January 1993 to April 1996. Two UPA'S, the VCD-5 and VCD-5A, were tested for 204 days and 665 days, respectively. The compressor gears and the distillation centrifuge drive belt were found to have operating lives of approximately 4,800 hours, equivalent to 3.9 years of operation on ISS for a crew of three at an average processing rate of 1.76 kg/h (3.97 lb/h). Precise alignment of the flex-splines of the fluids and purge pump motor drives is essential to avoid premature failure after about 400 hours of operation. Results indicate that, with some design and procedural modifications and suitable quality control, the required performance and operational life can be met with the VCD/UPA.

The Centrifuge Facility Life Sciences Glovebox configuration study

NASA Technical Reports Server (NTRS)

Sun, Sidney C.; Goulart, Carla V.

1992-01-01

Crew operations associated with nonhuman life sciences research on Space Station Freedom will be conducted in the Life Sciences Glovebox, whose enclosed work volume must accommodate numerous life science procedures. Two candidate Glovebox work volume concepts have been developed: one in which two operators work side-by-side, and another that conforms to the reach envelope of a single operator. Six test volunteers tested the concepts according to preestablished operational criteria. The wrap-around, single-operator concept has been judged the superior system.