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Sample records for fpms life test

  1. Installation and Final Testing of an On-Line, Multi-Spectrometer Fission Product Monitoring System (FPMS) to Support Advanced Gas Reactor (AGR) Fuel Testing and Qualification in the Advanced Test Reactor

    SciTech Connect

    J. K. Hartwell; D. M. Scates; M. W. Drigert; J. B. Walter

    2006-10-01

    The US Department of Energy (DOE) is initiating tests of reactor fuel for use in an Advanced Gas Reactor (AGR). The AGR will use helium coolant, a low-power-density ceramic core, and coated-particle fuel. A series of eight (8) fuel irradiation tests are planned for the Idaho National Laboratory’s (INL’s) Advanced Test Reactor (ATR). One important measure of fuel performance in these tests is quantification of the fission gas releases over the nominal 2-year duration of each irradiation experiment. This test objective will be met using the AGR Fission Product Monitoring System (FPMS) which includes seven (7) on-line detection stations viewing each of the six test capsule effluent lines (plus one spare). Each station incorporates both a heavily-shielded high-purity germanium (HPGe) gamma-ray spectrometer for quantification of the isotopic releases, and a NaI(Tl) scintillation detector to monitor the total count rate and identify the timing of the releases. The AGR-1 experiment will begin irradiation after October 1, 2006. To support this experiment, the FPMS has been completely assembled, tested, and calibrated in a laboratory at the INL, and then reassembled and tested in its final location in the ATR reactor basement. This paper presents the details of the equipment performance, the control and acquisition software, the test plan for the irradiation monitoring, and the installation in the ATR basement. Preliminary on-line data may be available by the Conference date.

  2. DESIGN OF AN ON-LINE, MULTI-SPECTROMETER FISSION PRODUCT MONITORING SYSTEM (FPMS) TO SUPPORT ADVANCED GAS REACTOR (AGR) FUEL TESTING AND QUALIFICATION IN THE ADVANCED TEST REACTOR

    SciTech Connect

    J. K. Hartwell; D. M. Scates; M. W. Drigert

    2005-11-01

    The US Department of Energy (DOE) is embarking on a series of tests of coated-particle reactor fuel for the Advanced Gas Reactor (AGR). As one part of this fuel development program a series of eight (8) fuel irradiation tests are planned for the Idaho National Laboratory’s (INL’s) Advanced Test Reactor (ATR). The first test in this series (AGR-1) will incorporate six separate “capsules” irradiated simultaneously, each containing about 51,000 TRISO-coated fuel particles supported in a graphite matrix and continuously swept with inert gas during irradiation. The effluent gas from each of the six capsules must be independently monitored in near real time and the activity of various fission gas nuclides determined and reported. A set of seven heavily-shielded high-purity germanium (HPGe) gamma-ray spectrometers and sodium iodide [NaI(Tl)] scintillation detector-based total radiation detectors have been designed, and are being configured and tested for use during the AGR-1 experiment. The AGR-1 test specification requires that the AGR-1 fission product measurement system (FPMS) have sufficient sensitivity to detect the failure of a single coated fuel particle and sufficient range to allow it to “count” multiple (up to 250) successive particle failures. This paper describes the design and expected performance of the AGR-1 FPMS.

  3. Design and Expected Performance of the AGR-1 Fission Product Monitoring System (FPMS)

    SciTech Connect

    John K. Hartwell; Dawn M. Scates

    2005-09-01

    The effluent from each test capsule of the AGR-1 experiment will be monitored by a detector system consisting of a gamma-ray spectrometer and a gross radiation detector. This collection of radiation measurement systems will be known as the AGR-1 Fission Product Monitoring System (FPMS). Proper design and functioning of the FPMS is critical to the success of the AGR-1 fuel test experiment.This document describes the AGR-1 FPMS and presents calculations indicating that this design will meet the pertinent test requirements.

  4. Piezoelectric multilayer actuator life test.

    PubMed

    Sherrit, Stewart; Bao, Xiaoqi; Jones, Christopher M; Aldrich, Jack B; Blodget, Chad J; Moore, James D; Carson, John W; Goullioud, Renaud

    2011-04-01

    Potential NASA optical missions such as the Space Interferometer Mission require actuators for precision positioning to accuracies of the order of nanometers. Commercially available multilayer piezoelectric stack actuators are being considered for driving these precision mirror positioning mechanisms. These mechanisms have potential mission operational requirements that exceed 5 years for one mission life. To test the feasibility of using these commercial actuators for these applications and to determine their reliability and the redundancy requirements, a life test study was undertaken. The nominal actuator requirements for the most critical actuators on the Space Interferometry Mission (SIM) in terms of number of cycles was estimated from the Modulation Optics Mechanism (MOM) and Pathlength control Optics Mechanism (POM) and these requirements were used to define the study. At a nominal drive frequency of 250 Hz, one mission life is calculated to be 40 billion cycles. In this study, a set of commercial PZT stacks configured in a potential flight actuator configuration (pre-stressed to 18 MPa and bonded in flexures) were tested for up to 100 billion cycles. Each test flexure allowed for two sets of primary and redundant stacks to be mechanically connected in series. The tests were controlled using an automated software control and data acquisition system that set up the test parameters and monitored the waveform of the stack electrical current and voltage. The samples were driven between 0 and 20 V at 2000 Hz to accelerate the life test and mimic the voltage amplitude that is expected to be applied to the stacks during operation. During the life test, 10 primary stacks were driven and 10 redundant stacks, mechanically in series with the driven stacks, were open-circuited. The stroke determined from a strain gauge, the temperature and humidity in the chamber, and the temperature of each individual stack were recorded. Other properties of the stacks, including the

  5. Thermionic cathode life test studies

    NASA Technical Reports Server (NTRS)

    Forman, R.; Elmer, P.

    1980-01-01

    An update on the life testing of commerical, high current density impregnated tungsten cathodes is presented. The B-type cathodes, operated at a current density of 2 A/cm2 and a cathode temperature of 1100 C have now been run satisfactorily for more than four years. The M-cathode, at the same current density but at an operating temperature of only 1010 C, have been tested for more than three years. The M-cathodes show no degradation in current over their present operating life whereas the current from the B-cathodes degrade about 6 percent after four years of operation.

  6. Accelerated life testing of spacecraft subsystems

    NASA Technical Reports Server (NTRS)

    Wiksten, D.; Swanson, J.

    1972-01-01

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

  7. Extended Life Testing of Duplex Ball Bearings

    NASA Technical Reports Server (NTRS)

    Mobley, Jeffrey; Robertson, Michael; Hodges, Charles

    2016-01-01

    Sierra Nevada Corporation’s Space Systems performed bearing life testing for the Scan Mirror Motor/Encoder Assembly (SMMA), part of the Scan Mirror Assembly on-board the Aerosol Polarimetry Sensor (APS) on the NASA Glory Spacecraft. The baseline bearing life test duration extended beyond the launch date for the Glory Spacecraft; a risk that the program was willing to undertake with the understanding that if any anomalies or failures occurred before the required life was achieved, then the mission objectives or operating profile could be modified on orbit to take those results into account. Even though the Glory Spacecraft failed to reach orbit during its launch in March of 2011, the bearing life testing was continued through a mutual understanding of value between Sierra Nevada Corporation and our customer; with a revised goal of testing to failure rather than completing a required number of life cycles. Life testing thus far has not only exceeded the original mission required life, but has also exceeded the published test data for Cumulative Degradation Factor (CDF) from NASA/CR-2009-215681. Many lessons were learned along the way regarding long life testing. The bearing life test has been temporarily suspended due to test support equipment issues.

  8. Intermediate Temperature Fluids Life Tests - Theory

    NASA Technical Reports Server (NTRS)

    Tarau, Calin; Sarraf, David B.; Locci, Ivan E.; Anderson, William G.

    2008-01-01

    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 750 K, including space nuclear power system radiators, and high temperature electronics cooling. Potential working fluids include organic fluids, elements, and halides, with halides being the least understood, with only a few life tests conducted. Potential envelope materials for halide working fluids include pure aluminum, aluminum alloys, commercially pure (CP) titanium, titanium alloys, and corrosion resistant superalloys. Life tests were conducted with three halides (AlBr3, SbBr3, and TiCl4) and water in three different envelopes: two aluminum alloys (Al-5052, Al-6061) and Cp-2 titanium. The AlBr3 attacked the grain boundaries in the aluminum envelopes, and formed TiAl compounds in the titanium. The SbBr3 was incompatible with the only envelope material that it was tested with, Al-6061. TiCl4 and water were both compatible with CP2-titanium. A theoretical model was developed that uses electromotive force differences to predict the compatibility of halide working fluids with envelope materials. This theory predicts that iron, nickel, and molybdenum are good envelope materials, while aluminum and titanium halides are good working fluids. The model is in good agreement with results form previous life tests, as well as the current life tests.

  9. SVN 9 End-Of-Life testing

    NASA Technical Reports Server (NTRS)

    Hatten, Gregory E.

    1995-01-01

    SVN 9 was a GPS Block I research and development satellite. When it was launched in Jun. 1984, questions regarding the future performance of atomic frequency standards in orbit remained to be answered. In Mar. 1994, after performing for twice its designed life span, SVN 9 was deactivated as a member of the operational GPS satellite constellation. During the next two months, U.S. Air Force and Rockwell personnel performed various tests to determine just how well the atomic frequency standards had withstood ten years in the space environment. The results of these tests are encouraging. With a full constellation of Block II/IIA satellites on orbit, as well as the anticipated launch of the Block IIR satellites, results from the end of life testing will be helpful in assuring the continued success of the GPS program.

  10. International Space Station Cathode Life Testing

    NASA Technical Reports Server (NTRS)

    Soulas, George C.; Sarver-Verhey, Timothy R.

    1997-01-01

    Four hollow cathode assembly (HCA) life tests were initiated at operating conditions simulating on-orbit operation of the International Space Station plasma contactor. The objective of these tests is to demonstrate the mission-required 18,000 hour lifetime with high-fidelity development model HCAS. HCAs are operated with a continuous 6 sccm xenon flow rate and 3 A anode current. On-orbit emission current requirements are simulated with a square waveform consisting of 50 minutes at a 2.5 A emission current and 40 minutes with no emission current. One HCA test was terminated after approximately 8,000 hours so that a destructive analysis could be performed. The analysis revealed no life-limiting processes and the ultimate lifetime was projected to be greater than the mission requirement. Testing continues for the remaining three HCAs which have accumulated approximately 8,000 hours, 10,000 hours, and 11,000 hours, respectively, as of June 1997. Anode and bias voltages, strong indicators of cathode electron emitter condition, are within acceptable ranges and have exhibited no life- or performance-limiting phenomena to date.

  11. 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.

  12. Ni-MH storage test and cycle life test

    NASA Technical Reports Server (NTRS)

    Dell, R. Dan; Klein, Glenn C.; Schmidt, David F.

    1994-01-01

    Gates Aerospace Batteries is conducting two long term test programs to fully characterize the NiMH cell technology for aerospace applications. The first program analyzes the effects of long term storage upon cell performance. The second program analyzes cycle life testing and preliminary production lot testing. This paper summarizes these approaches to testing the NiMH couple and culminates with initial storage and testing recommendations. Long term storage presents challenges to deter the adverse condition of capacity fade in NiMH cells. Elevated but stabilized pressures and elevated but stabilized end-of-charge voltages also appear to be a characteristic phenomenon of long term storage modes. However, the performance degradation is dependent upon specific characteristics of the metal-hydride alloy. To date, there is no objective evidence with which to recommend the proper method for storage and handling of NiMH cells upon shipment. This is particularly critical due to limited data points that indicate open circuit storage at room temperature for 60 to 90 days will result in irrecoverable capacity loss. Accordingly a test plan was developed to determine what method of mid-term to long-term storage will prevent irrecoverable capacity loss. The explicit assumption is that trickle charging at some rate above the self-discharge rate will prevent the irreversible chemical changes to the negative electrode that result in the irrecoverable capacity loss. Another premise is that lower storage temperatures, typically 0 C for aerospace customers, will impede any negative chemical reactions. Three different trickle charge rates are expected to yield a fairly flat response with respect to recoverable capacity versus baseline cells in two different modes of open circuit. Specific attributes monitored include: end-of-charge voltage, end-of-charge pressure, mid-point discharge voltage, capacity, and end-of-discharge pressure. Cycle life testing and preliminary production lot

  13. Accelerated aging test on LEDs life estimation

    NASA Astrophysics Data System (ADS)

    Dong, Yi; Zhang, Shu-sheng; Du, Jiang-qi

    2011-11-01

    Light-emitting diodes(LEDs) have become very attractive in different application field such as Solid State Lighting, automotive and street lights, due to their long operative lifetime, lower energy consumption etc. This paper mainly introduces the accelerated aging test, we focus our attention on the study of a life model for LEDs by relating the time to failure with the supplying condition. The constant accelerated aging experiments were firstly performed on LED samples. Process the experiment data by exploiting the degradation of LED optical power formula and degradation coefficient. Finally, the average lifetime of the samples under normal conditions was calculated via using numerical analytical method. According to data, analysis the test result and the failure mechanism of LED, provide the technical basis to improve product design and quality assurance.

  14. International Space Station Cathode Life Testing Status

    NASA Technical Reports Server (NTRS)

    Sarver-Verhey, Timothy R.; Soulas, George C.

    1998-01-01

    To demonstrate adequate lifetime and performance capabilities of a hollow cathode for use on the International Space Station (ISS) plasma contactor system, life tests of multiple hollow cathode assemblies (HCAs) were initiated at operating conditions simulating on-orbit operation. Three HCAs are presently being tested. These HCAs are operated with a continuous 6 sccm xenon flow rate and 3 A anode current. Emission current requirements are simulated with a square waveform consisting of 50 minutes at a 2.5 A emission current and 40 minutes with no emission current. As of July 1998, these HCAs have accumulated between 1 1,700 and 14,200 hours. While there have been changes in operatin, behavior the three HCAs continue to operate stably within ISS specifications and are expected to demonstrate the required lifetime.

  15. CPL Materials Life Cycle Test Facility

    NASA Technical Reports Server (NTRS)

    Buchko, Matthew T.

    1992-01-01

    The Capillary Pumped Loop (CPL) Materials Life Cycle Test Facility at the Goddard Space Flight Center (GSFC) will identify the operational parameters controlling the performance of a CPL over an extended period of time. The primary purpose of the facility is to investigate the long-term chemical compatibility between the anhydrous ammonia working fluid and the CPL materials of construction. Chemical reactions occurring within the system may produce non-condensable gases or particulate debris that can lead to a degradation in system performance. Small liquid samples will be drawn from the system at specific time intervals and analyzed to check for the presence of non-condensable gases. Periodic maximum and minimum heat load tests will be performed on the CPL to monitor trends in the overall system performance.

  16. 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.

  17. Extended life testing evaluation of complementary MOS integrated circuits

    NASA Technical Reports Server (NTRS)

    Brosnan, T. E.

    1972-01-01

    The purpose of the extended life testing evaluation of complementary MOS integrated circuits was twofold: (1) To ascertain the long life capability of complementary MOS devices. (2) To assess the objectivity and reliability of various accelerated life test methods as an indication or prediction tool. In addition, the determination of a suitable life test sequence for these devices was of importance. Conclusions reached based on the parts tested and the test results obtained was that the devices were not acceptable.

  18. 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.

  19. 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.

  20. 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.

  1. Millimeter wave TWT life test monitor

    NASA Astrophysics Data System (ADS)

    Stevens, Leon L.; Perretta, James; Belusar, Curt

    1990-07-01

    This report presents information on a monitor which can be used to capture and store life test data in real time. The hardware is specifically tailored to capture data without delay in real time. In addition to data acquisition, this report presents information on hardware and programs which can be used to transfer data to larger multitask computer systems where data analysis is more efficient. Because all multitask computer systems (even those as small as PCs) devote considerably amounts of time to tasks other than running the user's test program, they are not directly compatible with real-time data acquisition. Outside hardware is required to buffer real-time data and pass it to the computer system where final data reduction takes place. The interface hardware described in this report consists of two single task microprocessor systems. One system is based on the Motorola 6800 cpu with an SS50 mother board and SS30 input/output slots. The second system is a single board Motorola 6802 microprocessor.

  2. 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.

  3. An overview of ISS ECLSS life testing at NASA, MSFC.

    PubMed

    Tatara, J D; Roman, M C

    1998-01-01

    Numerous components have been developed for use in the International Space Station (ISS) Environmental Control and Life Support System (ECLSS). Although these components have performed admirably for short-duration subsystem tests, there is little long-range operational (life test) data available. It is important to know not only how long a subsystem is anticipated to perform, but also the problems that can be expected should subsystem components fail. For this reason, the National Aeronautics and Space Administration (NASA) at the Marshall Space Flight Center (MSFC) developed the ECLSS Life Test program. To date, assemblies and subassemblies that are being or have been tested include the Trace Contaminant Control Subassembly (TCCS), the Vapor Compression Distillation Urine Processor Assembly (VCD-UPA), the Four-Bed Molecular Sieve Carbon Dioxide Removal Assembly (4BMS-CDRA), and the Solid Polymer Electrolyzer Oxygen Generation Assembly (SPE-OGA). Also included in life testing are noncomponent life test studies. These include the Water Degradation Study and the Biofilm Life Test. The Water Degradation Study looks at water quality changes after exposure to simulated ISS pre-Water Recovery Management (WRM) conditions. The Biofilm Life Test will examine microbial accumulation on surfaces in a simulated ISS water delivery system. This article will briefly review the objectives of each life test program, the results of completed tests, and the major problems observed during the tests. PMID:11540459

  4. An overview of ISS ECLSS life testing at NASA, MSFC.

    PubMed

    Tatara, J D; Roman, M C

    1998-01-01

    Numerous components have been developed for use in the International Space Station (ISS) Environmental Control and Life Support System (ECLSS). Although these components have performed admirably for short-duration subsystem tests, there is little long-range operational (life test) data available. It is important to know not only how long a subsystem is anticipated to perform, but also the problems that can be expected should subsystem components fail. For this reason, the National Aeronautics and Space Administration (NASA) at the Marshall Space Flight Center (MSFC) developed the ECLSS Life Test program. To date, assemblies and subassemblies that are being or have been tested include the Trace Contaminant Control Subassembly (TCCS), the Vapor Compression Distillation Urine Processor Assembly (VCD-UPA), the Four-Bed Molecular Sieve Carbon Dioxide Removal Assembly (4BMS-CDRA), and the Solid Polymer Electrolyzer Oxygen Generation Assembly (SPE-OGA). Also included in life testing are noncomponent life test studies. These include the Water Degradation Study and the Biofilm Life Test. The Water Degradation Study looks at water quality changes after exposure to simulated ISS pre-Water Recovery Management (WRM) conditions. The Biofilm Life Test will examine microbial accumulation on surfaces in a simulated ISS water delivery system. This article will briefly review the objectives of each life test program, the results of completed tests, and the major problems observed during the tests.

  5. 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.

  6. Accelerated life testing effects on CMOS microcircuit characteristics

    NASA Technical Reports Server (NTRS)

    1980-01-01

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

  7. 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.

  8. Component Reliability Testing of Long-Life Sorption Cryocoolers

    NASA Technical Reports Server (NTRS)

    Bard, S.; Wu, J.; Karlmann, P.; Mirate, C.; Wade, L.

    1994-01-01

    This paper summarizes ongoing experiments characterizing the ability of critical sorption cryocooler components to achieve highly reliable operation for long-life space missions. Test data obtained over the past several years at JPL are entirely consistent with achieving ten year life for sorption compressors, electrical heaters, container materials, valves, and various sorbent materials suitable for driving 8 to 180 K refrigeration stages. Test results for various compressor systems are reported. Planned future tests necessary to gain a detailed understanding of the sensitivity of cooler performance and component life to operating constraints, design configurations, and fabrication, assembly and handling techniques, are also discussed.

  9. Halogen Occultation Experiment (HALOE) gas cell life test program

    NASA Technical Reports Server (NTRS)

    Sullivan, E. M.; Thompson, R. E.; Harvey, G. A.; Park, J. H.; Richardson, D. J.

    1983-01-01

    The Halogen Occultation Experiment (HALOE) will use gas filter correlation radiometry to measure the atmospheric concentration profiles of HCl, HF, NO, and CH4 from the Upper Atmosphere Research Satellite. The need to contain the gases for the gas filter measurements has resulted in the development of gas cells and the need for a life test program to demonstrate that the gas cells will perform their functions for extended periods (several years) of time. This report describes the tests in the life test program, the test apparatus used, and the analysis techniques developed. The report also presents data obtained during the first 14 months of the test program.

  10. 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).

  11. Survival test of submersible life support systems.

    PubMed

    Kuehn, L A; Ackles, K N; Cole, J D

    1977-04-01

    An experiment to validate predictions concerning submersible survivability was performed in December, 1975, by members of the Canadian Forces in the CF Submersible Lockout Vehicle SDL-1 in Halifax Harbour in water of 4 degrees C temperature at a depth of 40 ft. Data was collected relevant to the life support equipment to determine if it would operate for a simulated 6-h mission followed by a 24-h immobility period, at the end of which rescue was presumed to have occurred. Physiological data was collected from the submersible occupants in order to assess the degree of thermal stress experienced in this exercise. The experiment was terminated after a duration of approximately 25 h at 1 atm internal pressure due to exhaustion of two of the three on-board power supplies, causing the CO2 scrubbers to be inoperative and the CO2 content in the breathing gas to increase to toxic levels. Only two of the three submersible occupants experienced cold stress, one in the forward sphere and one in the aft sphere. At the end of 24 h, the core temperatures of both individuals had decreased by 0.5 degrees C and, during this time, skin temperatures, particularly of the extremities, had steadily and slowly decreased. Neither individual was hypothermic, but it was considered likely that after a 3-d exposure, at least two of the crew members would have had core temperatures of 35 degrees C or lower, assuming that CO2 poisoning had not occurred earlier.

  12. Fabrication and life testing of thermionic converters

    NASA Technical Reports Server (NTRS)

    Yang, L.; Bruce, R.

    1973-01-01

    An unfueled converter containing a chloride-fluoride duplex tungsten emitter of 4.78 eV vacuum work function was tested for 46,647 hours at an emitter temperature of 1973 K and an electrode power output of about 8 watts/sq cm. The test demonstrated the superior and stable performance of the (110) oriented tungsten emitter at high temperatures. Three 90 UC-10 ZrC(C/U = 1.04, tungsten additive = 4 wt %) fueled converters were fabricated and tested at an emitter temperature of 1873 K. Converter containing chloride-arc-cast duplex tungsten cladding showed temperature thermionic performance and slower rate of performance drop than converter containing chloride-fluoride duplex tungsten cladding. This is believed to be due to the superior fuel component diffusion resistance of the arc-cast tungsten substrate used in the fuel cladding. It was shown that a converter containing a carbide fueled chloride-arc-cast duplex tungsten emitter with an initial electrode power output of 6.80 watts/sq cm could still deliver an electrode power output of 6.16 watts/sq cm after 18,632 hours of operation at an emitter temperature of 1873 K.

  13. 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.

  14. 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 ...

  15. 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.

  16. Battery Technology Life Verification Test Manual Revision 1

    SciTech Connect

    Jon P. Christophersen

    2012-12-01

    The purpose of this Technology Life Verification Test (TLVT) Manual is to help guide developers in their effort to successfully commercialize advanced energy storage devices such as battery and ultracapacitor technologies. The experimental design and data analysis discussed herein are focused on automotive applications based on the United States Advanced Battery Consortium (USABC) electric vehicle, hybrid electric vehicle, and plug-in hybrid electric vehicle (EV, HEV, and PHEV, respectively) performance targets. However, the methodology can be equally applied to other applications as well. This manual supersedes the February 2005 version of the TLVT Manual (Reference 1). It includes criteria for statistically-based life test matrix designs as well as requirements for test data analysis and reporting. Calendar life modeling and estimation techniques, including a user’s guide to the corresponding software tool is now provided in the Battery Life Estimator (BLE) Manual (Reference 2).

  17. NASA Advanced Life Support Technology Testing and Development

    NASA Technical Reports Server (NTRS)

    Wheeler, Raymond M.

    2012-01-01

    Prior to 2010, NASA's advanced life support research and development was carried out primarily under the Exploration Life Support Project of NASA's Exploration Systems Mission Directorate. In 2011, the Exploration Life Support Project was merged with other projects covering Fire Prevention/Suppression, Radiation Protection, Advanced Environmental Monitoring and Control, and Thermal Control Systems. This consolidated project was called Life Support and Habitation Systems, which was managed under the Exploration Systems Mission Directorate. In 2012, NASA re-organized major directorates within the agency, which eliminated the Exploration Systems Mission Directorate and created the Office of the Chief Technologist (OCT). Life support research and development is currently conducted within the Office of the Chief Technologist, under the Next Generation Life Support Project, and within the Human Exploration Operation Missions Directorate under several Advanced Exploration System projects. These Advanced Exploration Systems projects include various themes of life support technology testing, including atmospheric management, water management, logistics and waste management, and habitation systems. Food crop testing is currently conducted as part of the Deep Space Habitation (DSH) project within the Advanced Exploration Systems Program. This testing is focused on growing salad crops that could supplement the crew's diet during near term missions.

  18. 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.

  19. Ion Engine Service Life Validation by Analysis and Testing

    NASA Technical Reports Server (NTRS)

    Brophy, John R.; Polk, James E.; Rawlin, Vincent K.

    1996-01-01

    Assessment of the NSTAR ion engine service life is being accomplished through a combination of long duration testing and probabilistic analyses of the credible failure modes. A literature review that examined 65 ion engine endurance tests perfromed over the past 35 years was conducted to compile a list of possible ion engine failure modes.

  20. Ion Engine Service Life Validation by Analysis and Testing

    NASA Technical Reports Server (NTRS)

    Brophy, John R.; Polk, James E.; Rawlin, Vincent K.

    1997-01-01

    Assessment of the NSTAR ion engine service life is being accomplished through a combination of long duration testing and probabilistic analyses of the credible failure modes. A literature review that examined 65 ion engine endurance tests perfromed over the past 35 years was conducted to compile a list of possible ion engine failure modes.

  1. 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.

  2. 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.

  3. Nickel-hydrogen cell low-Earth 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 the 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.

  4. Life testing of the ABI cryocooler: Two years complete

    NASA Astrophysics Data System (ADS)

    Ramsey, Perry G.; Swanson, Kirsten S.

    2012-04-01

    The Advanced Baseline Imager (ABI) is a prime payload for the GOES-R (Geostationary Operational Environmental Spacecraft) series of meteorological satellites. Focal plane temperature control is provided by a two-stage cryocooler based on the NGAS HEC (Northrop Grumman Aerospace Systems High Efficiency Cryocooler) design. To demonstrate the long-term operation of this cooler, a dedicated life test is being performed. The life test cooler is close to the flight design, differing only in minor details of the cold head structure. The test concept simulates continuous operation the cooler at flight like conditions. Long term testing started on 12 June 2009, and has continued to this date. Test performance and anomalies are discussed.

  5. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

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

  7. 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.

  8. Life-cycle testing of receiving waters with Ceriodaphnia dubia

    SciTech Connect

    Stewart, A.J.; Konetsky, B.K.

    1996-12-31

    Seven-day tests with Ceriodaphnia dubia are commonly used to estimate toxicity of effluents or receiving waters but can sometimes yield {open_quotes}no toxicity{close_quotes} outcomes even if pollutants are present. We conducted two sets of full life-cycle tests with C. dubia to (1) see if tests with longer exposure periods would reveal evidence for toxicity that might not be evident from 7-day tests, and (2) determine the relative importance of water quality versus food as factors influencing C. dubia reproduction. In the first set of tests, C. dubia was reared in diluted mineral water (negative control), water from a stream impacted by coal fly-ash, or water from a retention basin containing sediments contaminated with mercury, other metals and polychlorinated biphenyls. The second set of tests used water from the retention basin only, but this water was either filtered or not filtered, and food was either added or not added, prior to testing. C. dubia survival and reproduction did not differ much among the three water types in the first set of tests, but these two parameters were strongly affected by the filtering and food-addition treatments in the second set of tests. Thus, C. dubia appeared to be relatively insensitive to general water-quality factors, but quite sensitive to food-related factors. Regression analyses showed that the predictability of life-time reproduction by C. dubia from the results of 7-day tests was very low (R{sup 2}< 0.35) in five of the six experiments. The increase in predictability as a function of test duration also differed among water types in the first set of tests, and among treatments in the second set of tests. Thus, 7-day tests with C. dubia may be used to quantify water-quality problems, but it may not be possible to reliably extrapolate the results of these tests to longer time scales.

  9. 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.

  10. 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.

  11. 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.

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

    PubMed

    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.

  13. Johnson Space Center's Regenerative Life Support Systems Test Bed.

    PubMed

    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.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. Purpose in Life Test assessment using latent variable methods.

    PubMed

    Harlow, L L; Newcomb, M D; Bentler, P M

    1987-09-01

    A psychometric assessment was conducted on a slightly revised version of the Purpose in Life Test (PIL-R). Factor analyses revealed a large general factor plus four primary factors comprising lack of purpose in life, positive sense of purpose, motivation for meaning, and existential confusion. Validity models showed that the PIL-R was positively related to a construct of happiness and was negatively related to suicidality and meaninglessness. Reliability estimates ranged from 0.78 to 0.86. The revised version can be presented compactly and may be less confusing to subjects than the original PIL. PMID:3664045

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Electron microscopy of life-tested semiconductor laser diodes

    PubMed

    Vanzi; Bonfiglio; Magistrali; Salmini

    2000-06-01

    Electron Microscopy on life-tested 980 nm SL SQW InGaAs/AlGaAs laser diodes is able to find and analyze lattice defects responsible for the detected failures. Anyway, the origin and evolution of those defects remains questionable. Only the comparative analysis of life-test measurements, EBIC-FIB/TEM images, and charge-transport physics is able to point out a coherent framework for complete decoding of the failure kinetics. Minority-carrier diffusion and their enhanced recombination at defective lattice points are indicated, as the energy supply required for defect reaction and growth. The rules of charge diffusion drive both the reaction model, the interpretation of EBIC images and the expected electrical and optical effects. Strain release at the ultimate propagation of defects into the strained InGaAs quantum layer is then easily related to the final state of the failed devices.

  5. Review of mechanical vibration tests conducted on control moment gyros and life test fixtures

    NASA Technical Reports Server (NTRS)

    Burchill, R. F.

    1973-01-01

    Experimental vibration studies performed on a number of flight control moment gyros and bearing life test fixtures are summarized. Tests were performed at MSFC, at Wyle Laboratories, Huntsville, Alabama, and at the Bendix Corporation facilities in Teterboro, New Jersey. A description of test and analysis equipment is included as well as test procedures and overall performance rankings. Advanced ultrasonic rolling element bearing fault detection techniques were applied for bearing analysis along with conventional vibration and sound analysis procedures.

  6. Life Cycle Tests on a Hollow Cathode Based Plasma Contactor

    NASA Technical Reports Server (NTRS)

    Vaughn, Jason A.; Schneider, Todd A.; Munafo, Paul (Technical Monitor)

    2001-01-01

    The propulsive Small Expendable Deployer System (ProSEDS) mission is designed to provide an on-orbit demonstration of the electrodynamic propulsion capabilities of tethers in space. The ProSEDS experiment will be a secondary payload on a Delta II unmanned expendable booster with a mission duration of 12 days. A 5-km conductive tether is attached to the Delta II second stage and collects current from the low Earth orbit (LEO) plasma, and a Hollow Cathode Plasma Contactor (HCPC) emits the collected electrons from the Delta II, completing the electrical circuit to the ambient plasma. The HCPC for the ProSEDS mission have made it necessary to turn off the HCPC once a minute throughout the entire mission. Because of the unusual operating requirements by the ProSEDS mission, an engineering development unit of the HCPC was built to demonstrate the HCPC design would start reliably for the life of the ProSEDS mission. During the life test the engineering unit cycled for over 10,000 on/off cycles without missing a single start, and during that same test the HCPC unit demonstrated the capability to emit 0 to 5 A electron emission current. The performance of the HCPC unit during this life test will be discussed.

  7. A 5,000 hour xenon hollow cathode life test

    NASA Technical Reports Server (NTRS)

    Brophy, John R.; Garner, Charles E.

    1991-01-01

    A cathode life test voluntary terminated after 5024 hours of operation at 25 A is reported. The cathode including a 6.35-mm diameter by 57.12-mm long molybdenum tube with a nominal wall thickness of 0.38 mm is described along with a test facility and start-up procedure. It is shown that over the time of the experiment, the cathode-orifice diameter eroded from 1.80 mm to 2.08 mm, which corresponds to a ratio of the emission current to the orifice diameter at the end of the test of 12.0 A/mm. Tungsten deposits on the interior surface of the insert are detected in post-test analyses, and complete depletion of the original impregnate is suggested by X-ray diffraction analyses. A cathode-jet phenomenon in which energetic ions are produced during hollow-cathode operation at emission currents above 20 A is confirmed.

  8. 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

  9. 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.

  10. Post-Test Analysis of a 10-Year Sodium Heat Pipe Life Test

    NASA Technical Reports Server (NTRS)

    Rosenfeld, John H.; Locci, Ivan E.; Sanzi, James L.; Hull, David R.; Geng, Steven M.

    2011-01-01

    High-temperature heat pipes are being evaluated for use in energy conversion applications such as fuel cells, gas turbine re-combustors, Stirling cycle heat sources; and with the resurgence of space nuclear power both as reactor heat removal elements and as radiator elements. Long operating life and reliable performance are critical requirements for these applications. Accordingly, long-term materials compatibility is being evaluated through the use of high-temperature life test heat pipes. Thermacore, Inc., has carried out a sodium heat pipe 10-year life test to establish long-term operating reliability. Sodium heat pipes have demonstrated favorable materials compatibility and heat transport characteristics at high operating temperatures in air over long time periods. A representative one-tenth segment Stirling Space Power Converter heat pipe with an Inconel 718 envelope and a stainless steel screen wick has operated for over 87,000 hr (10 years) at nearly 700 C. These life test results have demonstrated the potential for high-temperature heat pipes to serve as reliable energy conversion system components for power applications that require long operating lifetime with high reliability. Detailed design specifications, operating history, and post-test analysis of the heat pipe and sodium working fluid are described. Lessons learned and future life test plans are also discussed.

  11. Half-life of naled under three test scenarios.

    PubMed

    Tietze, N S; Shaffer, K R; Hester, P G

    1996-06-01

    Decline of naled residue on filter paper was studied after exposure to ultra-low volume droplets in a settling chamber. Naled-treated filter papers were stored under 3 treatment scenarios: 1) in a dark environmental chamber at an average relative humidity (RH) of 46.9% and temperature of 24 degrees C, 2) in a dark environmental chamber at an average RH of 87.7% and temperature of 24 degrees C, and, 3) in direct sunlight in the field. Decline of naled followed first order kinetics in all cases; consequently, half-life of naled under each treatment was determined from the slope of each line. Half-life (+/- 1 SD) of naled was 8.17 +/- 1.24, 4.81 +/- 1.18, and 1.37 +/- 0.24 h, for treatment scenarios 1, 2, and 3, respectively. In each test, a significant (P < 0.05) decline in naled residue occurred between initial assessment and 4 h postapplication. The half-life of each treatment scenario was significantly (P < 0.05) different from that of the other 2 scenarios, indicating that both humidity and sunlight affect naled degradation rates. PMID:8827601

  12. 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.

  13. 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.

  14. 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.

  15. Pellicle Life-Testing for High Exposure Dose Applications

    NASA Astrophysics Data System (ADS)

    Schurz, Dan L.; Flack, Warren W.

    2002-12-01

    There are an increasing number of microlithography applications such as advanced packaging, nanotechnology and thin film head production that require the use of thick photoresist materials. The exposure dose requirements for these applications dramatically increase as the photoresist thickness increases. For example, some positive acting novolak photoresists require exposures in excess of 5000 mJoules/cm2 for 100 μm thick films. When a single reticle is used to pattern many wafers, a significant amount of light and heat energy is transferred from the lithography tool illumination source to the pellicle protecting the reticle image. In high volume production environments, a pellicle can be subjected to accumulated dosages exceeding 500 kJoules/cm2 within a matter of weeks. Because thick photoresist applications benefit from using 1X broadband steppers with high wafer plane irradiance, life-testing results were reviewed for broadband pellicles designed for maximum transmission at g, h and i-line wavelengths of Hg. Historically, pellicle lifetime testing was typically carried out only to approximately 500 kJoules/cm2 . While this test limit may have been sufficient for thin photoresist applications used in semiconductor applications, longer lifetime studies are required to determine pellicle durability for thick photoresist applications. In this study, life testing was performed on multiple pellicle films designed for broadband illumination, including nitrocellulose, cellulose acetate, cellulose ester and fluoropolymer films. Spectroscopic transmission at g, h and i-line was first measured on unexposed pellicles. The pellicles were attached to test reticles and exposed to high-energy doses on an Ultratech broadband stepper, accumulating up to 3000 kJoules/cm2 . Transmission was periodically re-measured and the pellicle films were visually inspected for color change and any apparent physical damage. Results were compared to the expected optical properties for each

  16. Integration Test Project of CEEF. - A Test Bed for Closed Ecological Life Support Systems -

    NASA Astrophysics Data System (ADS)

    Nitta, K.; Otsubo, K.; Ashida, A.

    CEEF (Closed Ecology Experiment Facilities) were installed at Rokkasho village in northern Japan, for the purpose of clarifying life-support mechanisms in a completely closed space, such as a Lunar or Mars base. An integration test using the Closed Plantation Experiment Facility and Closed Animal Breeding & Habitation Experiment Facility is needed before conducting an entire closed experiment including plants, animals and humans. These integration tests are planned to be conducted step by step from fiscal 2001 to 2008

  17. Integration test project of CEEF--a test bed for Closed Ecological Life Support Systems.

    PubMed

    Nitta, K; Otsubo, K; Ashida, A

    2000-01-01

    CEEF (Closed Ecology Experiment Facilities) were installed at Rokkasho village in northern Japan, for the purpose of clarifying life-support mechanisms in a completely closed space, such as a Lunar or Mars base. An integration test using the Closed Plantation Experiment Facility and Closed Animal Breeding & Habitation Experiment Facility is needed before conducting an entire closed experiment including plants, animals and humans. These integration tests are planned to be conducted step by step from fiscal 2001 to 2008.

  18. 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

  19. 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

  20. 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.

  1. 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

  2. Technology development: HEPA filter service life test plan

    SciTech Connect

    Kirchner, K.N.; Cummings, K.G.; Leck, W.C.; Fretthold, J.K.

    1995-05-31

    Rocky Flats Environmental Technology Site (the Site) has approximately 10,000 High Efficiency Particulate Air (HEPA) Filters installed in a variety of filter plenums. These ventilation/filtration plenum systems are used to control the release of airborne particulate contaminates to the environment during normal operations and also during potential design-based accidents. The operational integrity of the HEPA filter plenums is essential to maintaining the margins of safety as required by building specific Final Safety Analysis Reports (FSARS) for protection of the public and environment. An Unreviewed Safety Question Determination (USQD), USDQ-RFP94.0615-ARS, was conducted in 1994 addressing the potential inadequacy of the safety envelope for Protected Area building HEPA plenums. While conducting this USQD, questions were raised concerning the maximum service life criteria for HEPA filters. Accident scenarios in existing FSARs identify conditions that could potentially cause plugging or damage of down stream HEPA filters as a result of impaction from failed filters. Additionally, available data indicates that HEPA filters experience structural degradation due to the effects of age. The Unresolved Safety Question (USQ) compensatory measures thus require testing and analysis of used HEPA filters in order to determine and implement service life criteria.

  3. Life sciences passive GN2 freezer thermal performance test

    NASA Technical Reports Server (NTRS)

    Belshaw, G. W.

    1981-01-01

    Thermal performance tests that were conducted on the life sciences passive GN2 freezer project are summarized as well as the improvements to the freezers to improve the thermal performance of the containers. Procedures were developed, based upon these tests, to initially charge the freezers with LN2 and verify that the freezer performance is adequate for the mission duration. Improvements were made to the corvac sample tube to limit the amount of breakage due to thermal expansion of the liquid during freezing. A method of verifying the freezer vacuum insulative integrity was defined as well as a procedure for refurbishment of the internal vacuum level. Freezer modifications were made to ease the reevacuation of the containers. The orientation of the freezer in a 1-G environment, after being charged, had to remain in a vertical position. The LN2 boiloff rate increased significantly in a horizontal position. This resulted in a stowage definition in the spacecraft prior to launch. Functional testing, using the SL-1 mission timeline showed that the freezer will maintain samples in the frozen state for the duration of the mission.

  4. Optimal design of multiple stress constant accelerated life test plan on non-rectangle test region

    NASA Astrophysics Data System (ADS)

    Chen, Wenhua; Gao, Liang; Liu, Juan; Qian, Ping; Pan, Jun

    2012-11-01

    For optimal design of constant stress accelerated life test(CSALT) with two-stress, if the stresses could not reach the highest levels simultaneously, the test region becomes non-rectangular. For optimal CSALT design on non-rectangle test region, the present method is only focused on non-rectangle test region with simple boundary, and the optimization algorithm is based on experience which can not ensure to obtain the optimal plan. In this paper, considering the linear-extreme value model and the optimization goal to minimize the variance of lifetime estimate under normal stress, the optimal design method of two-stress type-I censored CSALT plan on general non-rectangular test region is proposed. First, two properties of optimal test plans are proved and the relationship of all the optimal test plans is determined analytically. Then, on the basis of the two properties, the optimal problem is simplified and the optimal design method of two-stress CSALT plan on general non-rectangular test region is proposed. Finally, a numerical example is used to illustrate the feasibility and effectiveness of the method. The result shows that the proposed method could obtain the optimal test plan on non-rectangular test regions with arbitrary boundaries. This research provides the theory and method for two-stress optimal CSALT planning on non-rectangular test regions.

  5. 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.

  6. 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.

  7. 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

  8. Real life testing of a Hybrid PEM Fuel Cell Bus

    NASA Astrophysics Data System (ADS)

    Folkesson, Anders; Andersson, Christian; Alvfors, Per; Alaküla, Mats; Overgaard, Lars

    Fuel cells produce low quantities of local emissions, if any, and are therefore one of the most promising alternatives to internal combustion engines as the main power source in future vehicles. It is likely that urban buses will be among the first commercial applications for fuel cells in vehicles. This is due to the fact that urban buses are highly visible for the public, they contribute significantly to air pollution in urban areas, they have small limitations in weight and volume and fuelling is handled via a centralised infrastructure. Results and experiences from real life measurements of energy flows in a Scania Hybrid PEM Fuel Cell Concept Bus are presented in this paper. The tests consist of measurements during several standard duty cycles. The efficiency of the fuel cell system and of the complete vehicle are presented and discussed. The net efficiency of the fuel cell system was approximately 40% and the fuel consumption of the concept bus is between 42 and 48% lower compared to a standard Scania bus. Energy recovery by regenerative braking saves up 28% energy. Bus subsystems such as the pneumatic system for door opening, suspension and brakes, the hydraulic power steering, the 24 V grid, the water pump and the cooling fans consume approximately 7% of the energy in the fuel input or 17% of the net power output from the fuel cell system. The bus was built by a number of companies in a project partly financed by the European Commission's Joule programme. The comprehensive testing is partly financed by the Swedish programme "Den Gröna Bilen" (The Green Car). A 50 kW el fuel cell system is the power source and a high voltage battery pack works as an energy buffer and power booster. The fuel, compressed hydrogen, is stored in two high-pressure stainless steel vessels mounted on the roof of the bus. The bus has a series hybrid electric driveline with wheel hub motors with a maximum power of 100 kW. Hybrid Fuel Cell Buses have a big potential, but there are

  9. 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).

  10. 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.

  11. Bioregenerative Planetary Life Support Systems Test Complex (BIO-Plex): NASA's Next Human-Rated Testing Facility

    NASA Technical Reports Server (NTRS)

    Tri, Terry O.

    1999-01-01

    As a key component in its ground test bed capability, NASA's Advanced Life Support Program has been developing a large-scale advanced life support test facility capable of supporting long-duration evaluations of integrated bioregenerative life support systems with human test crews. This facility-targeted for evaluation of hypogravity compatible life support systems to be developed for use on planetary surfaces such as Mars or the Moon-is called the Bioregenerative Planetary Life Support Systems Test Complex (BIO-Plex) and is currently under development at the Johnson Space Center. This test bed is comprised of a set of interconnected chambers with a sealed internal environment which are outfitted with systems capable of supporting test crews of four individuals for periods exceeding one year. The advanced technology systems to be tested will consist of both biological and physicochemical components and will perform all required crew life support functions. This presentation provides a description of the proposed test "missions" to be supported by the BIO-Plex and the planned development strategy for the facility.

  12. 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...

  13. Survey of state insurance commissioners concerning genetic testing and life insurance

    SciTech Connect

    McEwen, J.E.; McCarty, K.; Reilly, P.R. )

    1992-10-01

    Rapid advances in genetic testing have stimulated growing concern about the potential for misuse of genetic data by insurance companies, employers, and other third parties. Thus far, reports of genetically based discrimination in life insurance have been anecdotal. Reasoning that state insurance commissioners were likely to be aware of (1) the extent of current use of and interest in genetic tests by life insurers and (2) consumer complaints about insurance being denied because of genetic condition or because of genetic test results, the authors conducted a survey of that group. They received responses from 42 of the 51 jurisdictions. Results suggest (1) that those who regulate the life insurance industry do not yet perceive genetic testing to pose a significant problem in how insurers rate applicants, (2) that life insurers have much legal latitude to require genetic tests, and (3) that so far few consumers have formally complained to commissioners about the use of genetic data by life insurers.

  14. Life insurance and breast cancer risk assessment: adverse selection, genetic testing decisions, and discrimination.

    PubMed

    Armstrong, Katrina; Weber, Barbara; FitzGerald, Genevieve; Hershey, John C; Pauly, Mark V; Lemaire, Jean; Subramanian, Krupa; Asch, David A

    2003-07-30

    Life insurance industry access to genetic information is controversial. Consumer groups argue that access will increase discrimination in life insurance premiums and discourage individuals from undergoing genetic testing that may provide health benefits. Conversely, life insurers argue that without access to risk information available to individuals, they face substantial financial risk from adverse selection. Given this controversy, we conducted a retrospective cohort study to evaluate the impact of breast cancer risk information on life insurance purchasing, the impact of concerns about life insurance discrimination on use of BRCA1/2 testing, and the incidence of life insurance discrimination following participation in breast cancer risk assessment and BRCA1/2 testing. Study participants were 636 women who participated in genetic counseling and/or genetic testing at a University based clinic offering breast cancer risk assessment, genetic counseling, and BRCA1/2 testing between January 1995 and May 2000. Twenty-seven women (4%) had increased and six (1%) had decreased their life insurance since participation in breast cancer risk assessment. The decision to increase life insurance coverage was associated with predicted breast cancer risk (adjusted OR 1.03 for each 1% absolute increase in risk, 95% CI 1.01-1.10) and being found to carry a mutation in BRCA1/2 (OR 5.10, 95% CI 1.90-13.66). Concern about life insurance discrimination was inversely associated with the decision to undergo BRCA1/2 testing (RR 0.67, 95% CI 0.52-0.85). No respondent reported having life insurance denied or canceled. In this cohort of women, these results indicate that information about increased breast cancer risk is associated with increase in life insurance purchasing, raising the possibility of adverse selection. Although fear of insurance discrimination is associated with the decision not to undergo BRCA1/2 testing, there was no evidence of actual insurance discrimination from BRCA1

  15. Acceptance test report, plutonium finishing plant life safety upgrade

    SciTech Connect

    Hodge, S.G.

    1994-12-02

    This acceptance Test Procedure (ATP) has been prepared to demonstrate that modifications to the Fir Protection systems function as required by project criteria. The ATP will test the Fire Alarm Control Panels, Flow Alarm Pressure Switch, Heat Detectors, Smoke Detectors, Flow Switches, Manual Pull Stations, and Gong/Door By Pass Switches.

  16. Life prediction of 808nm high power semiconductor laser by accelerated life test of constant current stress

    NASA Astrophysics Data System (ADS)

    Yao, Nan; Li, Wei; Zhao, Yihao; Zhong, Li; Liu, Suping; Ma, Xiaoyu

    2015-10-01

    High power semiconductor laser is widely used because of its high transformation efficiency, good working stability, compact volume and simple driving requirements. Laser's lifetime is very long, but tests at high levels of stress can speed up the failure process and shorten the times to failure significantly. So accelerated life test is used here for forecasting the lifetime of 808nm CW GaAs/AlGaAs high power semiconductor laser that has an output power of 1W under 1.04A. Accelerated life test of constant current stress based on the Inverse Power Law Relationship was designed. Tests were conducted under 1.3A, 1.6A and 1.9A at room temperature. It is the first time that this method is used in the domestic research of laser's lifetime prediction. Applying Weibull Distribution to describe the lifetime distribution and analyzing the data of times to failure, characteristics lifetime's functional relationship model with current is achieved. Then the characteristics lifetime under normal current is extrapolated, which is 9473h. Besides, to confirm the validity of the functional relationship model, we conduct an additional accelerated life test under 1.75A. Based on this experimental data we calculated the characteristics lifetime corresponding to 1.75A that is 171h, while the extrapolated characteristics lifetime from the former functional relationship model is 162h. The two results shows 5% deviation that is very low and acceptable, which indicates that the test design is reasonable and authentic.

  17. 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 fifth generation Urine Processor Development Hardware. The Urine Processor Assembly (UPA) is a part of the Water Recovery System (WRS) on the ISS. It uses a chase change process called vapor compression distillation technology to remove contaminants from urine. 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.

  18. Testing and Life Prediction for Composite Rotor Hub Flexbeams

    NASA Technical Reports Server (NTRS)

    Murri, Gretchen B.

    2004-01-01

    A summary of several studies of delamination in tapered composite laminates with internal ply-drops is presented. Initial studies used 2D FE models to calculate interlaminar stresses at the ply-ending locations in linear tapered laminates under tension loading. Strain energy release rates for delamination in these laminates indicated that delamination would likely start at the juncture of the tapered and thin regions and grow unstably in both directions. Tests of glass/epoxy and graphite/epoxy linear tapered laminates under axial tension delaminated as predicted. Nonlinear tapered specimens were cut from a full-size helicopter rotor hub and were tested under combined constant axial tension and cyclic transverse bending loading to simulate the loading experienced by a rotorhub flexbeam in flight. For all the tested specimens, delamination began at the tip of the outermost dropped ply group and grew first toward the tapered region. A 2D FE model was created that duplicated the test flexbeam layup, geometry, and loading. Surface strains calculated by the model agreed very closely with the measured surface strains in the specimens. The delamination patterns observed in the tests were simulated in the model by releasing pairs of MPCs along those interfaces. Strain energy release rates associated with the delamination growth were calculated for several configurations and using two different FE analysis codes. Calculations from the codes agreed very closely. The strain energy release rate results were used with material characterization data to predict fatigue delamination onset lives for nonlinear tapered flexbeams with two different ply-dropping schemes. The predicted curves agreed well with the test data for each case studied.

  19. Instrumentation for accelerated life tests of concentrator solar cells.

    PubMed

    Núñez, N; Vázquez, M; González, J R; Jiménez, F J; Bautista, J

    2011-02-01

    Concentrator photovoltaic is an emergent technology that may be a good economical and efficient alternative for the generation of electricity at a competitive cost. However, the reliability of these new solar cells and systems is still an open issue due to the high-irradiation level they are subjected to as well as the electrical and thermal stresses that they are expected to endure. To evaluate the reliability in a short period of time, accelerated aging tests are essential. Thermal aging tests for concentrator photovoltaic solar cells and systems under illumination are not available because no technical solution to the problem of reaching the working concentration inside a climatic chamber has been available. This work presents an automatic instrumentation system that overcomes the aforementioned limitation. Working conditions have been simulated by forward biasing the solar cells to the current they would handle at the working concentration (in this case, 700 and 1050 times the irradiance at one standard sun). The instrumentation system has been deployed for more than 10 000 h in a thermal aging test for III-V concentrator solar cells, in which the generated power evolution at different temperatures has been monitored. As a result of this test, the acceleration factor has been calculated, thus allowing for the degradation evolution at any temperature in addition to normal working conditions to be obtained. PMID:21361622

  20. Thermal vacuum life test facility for radioisotope thermoelectric generators

    NASA Astrophysics Data System (ADS)

    Deaton, R. L.; Goebel, C. J.; Amos, W. R.

    In the late 1970's, the Department of Energy (DOE) assigned Monsanto Research Corporation, Mound Facility, now operated by EG and G Mound Applied Technologies, the responsibility for assembling and testing General Purpose Heat Source (GPHS) radioisotope thermoelectric generators (RTGs). Assembled and tested were five RTGs, which included four flight units and one non-flight qualification unit. Figure 1 shows the RTG, which was designed by General Electric AstroSpace Division (GE/ASD) to produce 285 W of electrical power. A detailed description of the processes for RTG assembly and testing is presented by Amos and Goebel (1989). The RTG performance data are described by Bennett, et al., (1986). The flight units will provide electrical power for the National Aeronautics and Space Administration's (NASA) Galileo mission to Jupiter (two RTGs) and the joint NASA/European Space Agency (ESA) Ulysses mission to study the polar regions of the sun (one RTG). The remaining flight unit will serve as the spare for both missions, and a non-flight qualification unit was assembled and tested to ensure that performance criteria were adequately met.

  1. A Life in Language Testing: An Interview with Charles Stansfield

    ERIC Educational Resources Information Center

    Reed, Daniel J.; Bowles, Melissa

    2008-01-01

    Dr. Charles W. Stansfield is widely recognized as one of the most important figures in contemporary language testing. He is respected and relied upon by leading language professionals in education, government agencies, academia, and the private sector. During his 40 years of working with languages, he has been a secondary school teacher of…

  2. Development, testing, and certification of life sciences engineering solar collector

    NASA Technical Reports Server (NTRS)

    Caudle, J. M.

    1978-01-01

    Results are presented for the development of an air flat plate collector for use with solar heating, combined heating and cooling, and hot water systems. The contract was for final development, testing, and certification of the collector, and for delivery of a 320 square feet collector panel.

  3. Mechanical Component Lifetime Estimation Based on Accelerated Life Testing with Singularity Extrapolation

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Chuckpaiwong, I.; Liang, S. Y.; Seth, B. B.

    2002-07-01

    Life testing under nominal operating conditions of mechanical parts with high mean lifetime between failure (MTBF) often consumes a significant amount of time and resources, rendering such procedures expensive and impractical. As a result, the technology of accelerated life testing (ALT) has been developed for testing at high stress levels (e.g. temperature, voltage, pressure, corrosive media, load, vibration amplitude, etc.) so that it can be extrapolated—through a physically reasonable statistical model—to obtain estimations of life at lower, normal stress levels or even limit stress levels. However, the issue of prediction accuracy associated with extrapolating data outside the range of testing, or even to a singularity level (no stress), has not yet been fully addressed. In this research, an accelerator factor is introduced into an inverse power law model to estimate the life distribution in terms of time and stresses. Also, a generalized Eyring model is set up for singularity extrapolation in handling limit stress level conditions. The procedure to calibrate the associated shape factors based on the maximum likelihood principle is also formulated. The methodology implementation, based on a one-main-step, multiple-step-stress test scheme, is experimentally illustrated with tapered roller bearing under the stress of environmental corrosion as a case study. The experimental results show that the developed accelerated life test model can effectively evaluate the life probability of a bearing based on accelerated testing data when extrapolating to the stress levels within or outside the range of testing.

  4. Fatigue life on a full scale test rig: Forged versus cast wind turbine rotor shafts

    NASA Astrophysics Data System (ADS)

    Herrmann, J.; Rauert, T.; Dalhoff, P.; Sander, M.

    2016-09-01

    To reduce uncertainties associated with the fatigue life of the highly safety relevant rotor shaft and also to review today's design practice, the fatigue behaviour will be tested on a full scale test rig. Until now tests on full scale wind turbine parts are not common. Therefore, a general lack of experience on how to perform accelerated life time tests for those components exists. To clarify how to transfer real conditions to the test environment, the arrangements and deviations for the upcoming experimental test are discussed in detail. In order to complete investigations of weight saving potentials, next to getting a better comprehension of the fatigue behaviour by executing a full scale test, a further outcome are suggestions for the usage of cast and forged materials regarding the fatigue and the remaining life of the rotor shaft. It is shown, that it is worthwhile to think about a material exchange for the forged rotor shaft.

  5. 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.

  6. 28,000 Hour Xenon Hollow Cathode LifeTest Results

    NASA Technical Reports Server (NTRS)

    Sarver-Verhey, Timothy R.

    1997-01-01

    The International Space Station Plasma Contactor System requires a hollow cathode assembly (HCA) with a lifetime of at least 18,000 hours. Critical components of the HCA include the hollow cathode and electron emitter. 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 the hollow cathode design and contamination control protocols. The life test accumulated 27,800 hours of operation before failing to ignite. The hollow cathode exhibited relatively small changes in operating parameters over the course of the test. This life test is the longest duration test of a high current xenon hollow cathode reported to date.

  7. Lanthanide Complexes as a Test for Evidence of Life

    NASA Technical Reports Server (NTRS)

    Benavides, Jeannette

    1998-01-01

    The objective of this research is to advance the understanding of the interaction of lanthanide metals with biological organic molecules and to develop a technique to detect these compounds in the solid state and in situ in Mars and other planetary bodies. The detection of these complexes should provide evidence of life past or present. In addition, detection of the metals alone will provide important information about the geological history of a planetary body. Lanthanides were chosen as our focus of interest because they form very stable complexes with organic molecules in solution and they produce intense luminescence in the ultraviolet and visible spectra. The rare earth complexes available are mostly synthetic for diverse applications in medicine. There is not much work done on the complexes that form in nature. Lanthanides have many applications and they are mined aR over the world, however, since the interest has been only in the elements, the analytical techniques employed destroy any organic ligands that may be present. In order to determine if and which lanthanide complexes form in nature and their concentration, soil samples have been collected from areas rich in soluble lanthanide compounds like phosphates and also rich in vegetation. The soil samples will be analyzed and the lanthanide complexes if present will be isolated and characterized. A spectrometer to detect the lanthanide complexes in situ and in the solid state will be designed. In this workshop, the research approach and its implications will be discussed.

  8. 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

  9. 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

  10. FIRST INTERIM STATUS REPORT MODEL 9975 LIFE EXTENSION PACKAGE TESTING

    SciTech Connect

    Daugherty, W.; Stefek, T.

    2010-01-27

    Three 9975 packages have been instrumented and exposed to bounding storage conditions to help identify the extent to which laboratory test results for fiberboard, O-rings and other components apply within a full-scale package. To date, changes observed in the fiberboard overpack and O-ring seals are generally consistent with the behavior of laboratory samples. The lead shield within each package has developed a corrosion layer of lead carbonate, consistent with other 9975 packages. However, the morphology of the corrosion layer is different within these packages, possibly as a result of the severity of the conditioning environments beyond normal service conditions. Conditioning of the second package, LE2, has been discontinued due to the degree of degradation of the fiberboard, and its components have received a final examination. Additional testing will be performed on samples removed from the fiberboard assembly to verify its final condition. The other two packages will continue in test. This is an interim status report for experiments carried out per Task Technical Plan WSRC-TR-2005-00014 [1], which is part of the comprehensive 9975 package surveillance program [2]. The primary goal of this task is to validate aging models currently under development based on lab scale testing of the fiberboard overpack and containment vessel O-rings. A secondary goal is to examine the behavior of the lead shielding under bounding conditions. This task provides an integrated assessment of the package response to environmental extremes, and demonstrates the extent to which data from small samples scale up to a full package. Three 9975 packages have been modified to provide instrumentation for monitoring package response and performance to environmental aging. Each package has a different environmental exposure history.

  11. Life cycle test results of a bipolar nickel hydrogen battery

    NASA Technical Reports Server (NTRS)

    Cataldo, R. L.

    1985-01-01

    A history of low Earth orbit laboratory test data on a 6.5 Ah bipolar nickel hydrogen battery designed and built at the NASA Lewis Research Center is presented. During the past several years the Storage and Thermal Branch has been deeply involved in the design, development, and optimization of nickel hydrogen devices. The bipolar concept is a means of achieving the goal of producing an acceptable battery of higher energy density, able to withstand the demands of low Earth orbit regimes.

  12. FIRST INTERIM STATUS REPORT: MODEL 9975 LIFE EXTENSION PACKAGE TESTING

    SciTech Connect

    Daugherty, W.; Stefek, T.

    2009-12-29

    Three 9975 packages have been instrumented and exposed to bounding storage conditions to help identify the extent to which laboratory test results for fiberboard, O-rings and other components apply within a full-scale package. To date, changes observed in the fiberboard overpack and Oring seals are generally consistent with the behavior of laboratory samples. The lead shield within each package has developed a corrosion layer of lead carbonate, consistent with other 9975 packages. However, the morphology of the corrosion layer is different within these packages, possibly as a result of the severity of the conditioning environments beyond normal service conditions. Conditioning of the second package, LE2, has been discontinued due to the degree of degradation of the fiberboard, and its components have received a final examination. Additional testing will be performed on samples removed from the fiberboard assembly to verify its final condition. The other two packages will continue in test. This is an interim status report for experiments carried out per Task Technical Plan WSRC-TR-2005-00014 [1], which is part of the comprehensive 9975 package surveillance program [2]. The primary goal of this task is to validate aging models currently under development based on lab scale testing of the fiberboard overpack and containment vessel O-rings. A secondary goal is to examine the behavior of the lead shielding under bounding conditions. This task provides an integrated assessment of the package response to environmental extremes, and demonstrates the extent to which data from small samples scale up to a full package. Three 9975 packages have been modified to provide instrumentation for monitoring package response and performance to environmental aging. Each package has a different environmental exposure history.

  13. Biometric identification devices -- Laboratory testing vs. real life

    SciTech Connect

    Ahrens, J.S.

    1997-05-01

    For over fifteen years Sandia National Laboratories has been involved in laboratory testing of biometric identification devices. The key concept of biometric identification devices is the ability for the system to identify some unique aspect of the individual rather than some object a person may be carrying or some password they are required to know. Tests were conducted to verify manufacturer`s performance claims, to determine strengths/weaknesses of devices, and to determine devices that meet the US Department of energy`s needs. However, during recent field installation, significantly different performance was observed than was predicted by laboratory tests. Although most people using the device believed it operated adequately, the performance observed was over an order of magnitude worse than predicted. The search for reasons behind this gap between the predicted and the actual performance has revealed many possible contributing factors. As engineers, the most valuable lesson to be learned from this experience is the value of scientists and engineers with (1) common sense, (2) knowledge of human behavior, (3) the ability to observe the real world, and (4) the capability to realize the significant differences between controlled experiments and actual installations.

  14. Life testing of implantable batteries for a total artificial heart.

    PubMed

    Powers, R A; Wolga, A E; Ochs, B D; Yu, L S; Kung, R T

    1993-01-01

    Although lithium cells may promise to be ideal as a rechargeable internal battery for a TAH, NiCd cells remain the most easily accessible off the shelf energy source. Twelve 1.2 A.hr prismatic NiCd (Sanyo, San Diego, CA) cells in series are being tested under the load condition of our TAH. The load consisted of a 1.5 A DC current with 1 A pulses of 40 msec duration at 3.33 Hz (100 bpm), a condition that can generate up to 8 L/min of cardiac output at physiologic pressures. Cells were tested at 37 degrees C. Cell voltages and temperatures were monitored. Testing was accelerated to five charge/discharge cycles per day. Discharge was terminated when any one cell dropped below 1.1 V. Charging (C/4) was continued until the battery voltage indicated a change in slope. Cell temperatures remained below 42 degrees C throughout the charge/discharge cycle. The battery pack settled to a nearly constant capacity of over 25 min after 10 cycles and has accumulated more than 1,000 cycles. Voltage differences among cells were small (SD < 25 mV), indicating consistency among cells. NiCd cells can serve as a reliable interim for TAH internal battery application.

  15. 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.

  16. Life test results for an ensemble of CO2 lasers

    NASA Technical Reports Server (NTRS)

    Peruso, C. J.; Degnan, J. J.; Hochuli, U. E.

    1978-01-01

    The effects of cathode material, cathode operating temperature, anode configuration, window materials, and hydrogen additives on laser lifetime are determined. Internally oxidized copper and silber-copper alloy cathodes were tested. The cathode operating temperature was raised in some tubes through the use of thermal insulation. Lasers incorporating thermally insulated silver copper oxide cathodes clearly yielded the longest lifetimes-typically in excess of 22,000 hours. The use of platinum sheet versus platinum pin anodes had no observable effect on laser lifetime. Similarly, the choice of germanium, cadmium telluride, or zinc selenide as the optical window material appears to have no impact on lifetime.

  17. 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.

  18. 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.

  19. 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.

  20. Closed Ecological Life Support Systems (CELSS) Test Facility

    NASA Technical Reports Server (NTRS)

    Macelroy, Robert D.

    1992-01-01

    The CELSS Test Facility (CTF) is being developed for installation on Space Station Freedom (SSF) in August 1999. It is designed to conduct experiments that will determine the effects of microgravity on the productivity of higher (crop) plants. The CTF will occupy two standard SSF racks and will accommodate approximately one square meter of growing area and a canopy height of 80 cm. The growth volume will be isolated from the external environment, allowing stringent control of environmental conditions. Temperature, humidity, oxygen, carbon dioxide, and light levels will all be closely controlled to prescribed set points and monitored. This level of environmental control is needed to prevent stress and allow accurate assessment of microgravity effect (10-3 to 10-6 x g). Photosynthetic rates and respiration rates, calculated through continuous recording of gas concentrations, transpiration, and total and edible biomass produced will be measured. Toxic byproducts will be monitored and scrubbed. Transpiration water will be collected within the chamber and recycled into the nutrient solution. A wide variety of crop plants, e.g., wheat, soy beans, lettuce, potatoes, can be accommodated and various nutrient delivery systems and light delivery systems will be available. In the course of its development, the CTF will exploit fully, and contribute importantly, to the state-of-art in closed system technology and plant physiology.

  1. Life cycle test results of a bipolar nickel hydrogen battery

    NASA Technical Reports Server (NTRS)

    Cataldo, R. L.

    1985-01-01

    A history is given of low Earth orbit (LEO) laboratory test data on a 6.5 ampere-hour bipolar nickel hydrogen battery designed and built at the NASA Lewis Research Center. The bipolar concept is a means of achieving the goal of producing an acceptable battery, of higher energy density, able to withstand the demands of low-Earth-orbit regimes. Over 4100 LEO cycles were established on a ten cell battery. It seems that any perturbation on normal cycling effects the cells performance. Explanations and theories of the battery's behavior are varied and widespread among those closely associated with it. Deep discharging does provide a reconditioning effect and further experimentation is planned in this area. The battery watt-hour efficiency is about 75 percent and the time averaged, discharge voltage is about 1.26 volts for all cells at both the C/4 and LEO rate. Since a significant portion of the electrode capacity has degraded, the LEO cycle discharges are approaching depths of 90 to 100 percent of the high rate capacity. Therefore, the low end-of-discharge voltages occur precipitously after the knee of the discharge curve and is more an indication of electrode capacity and is a lesser indicator of overall cell performance.

  2. Life cycle test results of a bipolar nickel hydrogen battery

    NASA Astrophysics Data System (ADS)

    Cataldo, R. L.

    1985-07-01

    A history is given of low Earth orbit (LEO) laboratory test data on a 6.5 ampere-hour bipolar nickel hydrogen battery designed and built at the NASA Lewis Research Center. The bipolar concept is a means of achieving the goal of producing an acceptable battery, of higher energy density, able to withstand the demands of low-Earth-orbit regimes. Over 4100 LEO cycles were established on a ten cell battery. It seems that any perturbation on normal cycling effects the cells performance. Explanations and theories of the battery's behavior are varied and widespread among those closely associated with it. Deep discharging does provide a reconditioning effect and further experimentation is planned in this area. The battery watt-hour efficiency is about 75 percent and the time averaged, discharge voltage is about 1.26 volts for all cells at both the C/4 and LEO rate. Since a significant portion of the electrode capacity has degraded, the LEO cycle discharges are approaching depths of 90 to 100 percent of the high rate capacity. Therefore, the low end-of-discharge voltages occur precipitously after the knee of the discharge curve and is more an indication of electrode capacity and is a lesser indicator of overall cell performance.

  3. Book Review. Testing Testing: Social Consequences of the Examined Life, by F. Allan Hanson.

    ERIC Educational Resources Information Center

    Sinha, Birendra K.

    1994-01-01

    The reviewed book analyzes many facets of the testing enterprise from a sociocultural perspective, emphasizing the power motive of test givers. Part I on Authenticity Tests discusses the practice of using tests to determine innocence, guilt, and honesty with regard to culturally important behaviors. Part II addresses the use of ability tests for…

  4. 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.

  5. ESP – Data from Restarted Life Tests of Various Silicon Materials

    SciTech Connect

    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.

  6. 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.

  7. 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.

  8. 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…

  9. 30 CFR 27.35 - Tests to determine life of critical components and subassemblies.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 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...

  10. 30 CFR 27.35 - Tests to determine life of critical components and subassemblies.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 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...

  11. 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...

  12. The Development and Analysis of a Test in Life Science for Middle School Students.

    ERIC Educational Resources Information Center

    Singh, Balwant; And Others

    It is suggested that most standardized science tests do not adequately assess the majority of concepts taught as part of the very diversified middle school science curriculum. The 50-item Life Science Test constructed by Portland Public Schools, Maine, herein presented, aims to resolve this inadequacy. The 40-minute multiple choice test…

  13. 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.

  14. 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.

  15. 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

  16. Indoor test for thermal performance evaluation on life sciences engineering (air) solar collector

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The test procedure used and the results obtained from an evaluation test program conducted to obtain thermal performance data on a life sciences double-glazed air solar collector under simulated conditions is discussed. These tests were made using the Marshall Space Flight Center's solar simulator. A time constant test and incident angle modifier test were also conducted to determine the transient effect and the incident angle effect on the collector. These results and the results of the collector load test are also discussed.

  17. BEO-Life, a Test and Refurbishment Support for Biological Research Facilities

    NASA Astrophysics Data System (ADS)

    Engeln, I.; Hueser, D.; Reese, C.; Schoenfeld, R.

    Since the ISS commenced its operational phase, the need of ground based test and refurbishment support, facilitating the utilisation of the station and especially its facilities for biological research, becomes increasingly important.. The onboard biological research facilities (e.g. BIOLAB) are designed and built for a life time of 10 years, requiring the regular exchange of the integrated life support systems. The exact conditioning of the atmosphere in these systems plays an important role for the scientific outcome. The composition of the air (O2, N2 and CO2) as well as the humidity and the temperature inside the experiment chambers containing the plants and cell-cultures needs to be adjustable for various types of experiments. Since the various ingredients for a life support system are consumables, which consumption depends on the number of performed experiments, the life support systems needs to be refurbished from time to time. Our contribution to this challenge is BEO- Life, which offers a unique test, refurbishment and qualification environment for maintenance and re-supply for life support systems of the ISS onboard biological facilities. BEO-Life provides the ground support for all these tasks, such as tests, maintenance, verification and procedures. To fulfil the demanding requirements for the automatic and stable conditioning of the life support system, a complex arrangement of pumps, valves, sensors and an electronic system including software with exact control algorithms is provided. Beside the refurbishment activities, BEO-Life will support preliminary ground-based investigations of scientists before utilisation of the ISS biological research facilities, too. In conclusion, we offer a novel service element for the ground-based maintenance of biological research facilities onboard the ISS. This service can be easily adapted to the needs of users for preparatory work.

  18. Life test data and flight predictions for nickel-hydrogen (Ni-H/sub 2/) batteries

    SciTech Connect

    Levy, E.

    1982-08-01

    A substantial test data base is accumulating on Ni-H/sub 2/ cells, batteries and positive plates to support life predictions of greater than 10 years in synchronous and elliptical orbits and greater than 5000 cycles in low earth orbit, all at high (80 percent) depth of discharge. All cells, batteries, and positive plates used for this test data base are of a common design. The cell is the Air Force/ Hughes ''pineapple slice'' cell. The positive plate is the Air Force/EPI Colorado Springs dry sinter electrochemically impregnated plate. Cell testing includes real time tests of cells and/or batteries in all three (low earth, elliptical, synchronous) orbits. Plate testing includes real time and accelerated tests in boilerplate assemblies. Life predictions are based on understanding cell wearout modes and comparing wearout rates of nickel-hydrogen components to those of nickel-cadmium cells.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Life Satisfaction and Its Correlates among College Students in China: A Test of Social Reference Theory

    PubMed Central

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

    2013-01-01

    Introduction 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. Methods 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. Results 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. Conclusions 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. PMID:25042946

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

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

    SciTech Connect

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

    1985-01-01

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

  10. 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.

  11. Continued life test results for an ensemble of CO2 lasers

    NASA Technical Reports Server (NTRS)

    Hochuli, U. E.

    1981-01-01

    The life test results of five 16 low pressure CW CO2 lasers with a nominal output of 1 watt are presented. One laser quickly died while the remaining four lasers reached half power output at 38,000, 40,000, 40,000 and 40,000 hours respectively. These results show the potential for a 50,000 hour laser while the average life of the 16 tested lasers was 22,500 hours. It is further indicated that the cathode sputtering products, which settle on the glass walls of the cathode sleeve, form an increasingly heavy film as the laser ages.

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

    SciTech Connect

    Jeong, H. Y.; Ha, K. S.; Lee, K. L.; Chang, W. P.; Kim, Y. I.

    2012-07-01

    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 conditions 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)

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. Overview of the Environmental Control and Life Support System (ECLSS) testing at MSFC.

    PubMed

    Traweek, M S; Tatara, J D

    1998-01-01

    Previously, almost all water used by the crew during space flight has been transported from earth or generated inflight 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 eight-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 (MSFC) is to conduct testing 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 article provides an overview of MSFC's ECLSS testing. Specific tests include: the Stage 10 Water Recovery Test; the Contaminant Injection Test; the Four-Bed Molecular Sieve Performance Enhancement Test; and Life Testing.

  18. 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.

  19. ESP - Data From Restarted Life Tests of Various Silicone Materials - 2009

    SciTech Connect

    J. W. Schneider

    2010-02-24

    Enhanced Surveillance Project (ESP) 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 ESP funding allowed the restart in FY97. This report will provide data on materials used on various programs and on experimental materials not used in production. Charts for the various materials at different thickness, compression, and temperature combinations illustrate trends for the load-bearing properties of the materials.

  20. ESP – Data from Restarted Life Tests of Various Silicone Materials - 2011

    SciTech Connect

    Jim Schneider

    2011-12-31

    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. This report will provide data on materials used in production and on experimental materials not used in production. Charts for the various materials at different thickness, compression, and temperature combinations illustrate trends for the load-bearing properties of the materials.

  1. Operational psychology countermeasures during the Lunar-Mars Life Support Test Project.

    PubMed

    Holland, A W; Curtis, K

    1998-01-01

    The Crew and Thermal Systems Division at the NASA Johnson Space Center conducted a series of human-rated tests, termed the Lunar-Mars Life Support Test Project (LMLSTP), designed to advance technology in closed life support systems. As the duration of these tests lengthened, the psychological factors associated with placing humans in these environments became increasingly salient to successful mission completion. A number of psychological activities were conducted to ensure successful operations and protect crew member well-being, including individual crew member selection, crew composition, training and preparation, family inclusion, educational briefings, in-mission tracking, operational interventions, and postmission repatriation. This article describes these activities, the rationale behind their design, the similarities and differences to techniques utilized for spaceflight, and considerations related to designing psychological countermeasures for confined environments. In addition to testing physical and engineering systems, the LMLSTP series functioned as an effective testbed for developing operational concepts and countermeasures for extended space missions.

  2. Operational psychology countermeasures during the Lunar-Mars Life Support Test Project.

    PubMed

    Holland, A W; Curtis, K

    1998-01-01

    The Crew and Thermal Systems Division at the NASA Johnson Space Center conducted a series of human-rated tests, termed the Lunar-Mars Life Support Test Project (LMLSTP), designed to advance technology in closed life support systems. As the duration of these tests lengthened, the psychological factors associated with placing humans in these environments became increasingly salient to successful mission completion. A number of psychological activities were conducted to ensure successful operations and protect crew member well-being, including individual crew member selection, crew composition, training and preparation, family inclusion, educational briefings, in-mission tracking, operational interventions, and postmission repatriation. This article describes these activities, the rationale behind their design, the similarities and differences to techniques utilized for spaceflight, and considerations related to designing psychological countermeasures for confined environments. In addition to testing physical and engineering systems, the LMLSTP series functioned as an effective testbed for developing operational concepts and countermeasures for extended space missions. PMID:11871454

  3. Implications of genetic testing: discrimination in life insurance and future directions.

    PubMed

    Mould, Annie

    2003-05-01

    This article examines the possibility of genetic discrimination in life insurance and discusses the inability of current Australian legislation to deal adequately with genetic test result information. Genetic information has certain features that distinguish it from other medical information and thus a specialist legislative package is required to regulate its use. This article outlines how current practices in the life insurance industry are inconsistent with notions of human rights. Several legislative options are suggested and examined. Given the negative and damaging impact that adverse selection is likely to have on the life insurance industry should the use of all genetic test results be prohibited, an approach which modifies the current regime is recommended. This includes a comprehensive review scheme and the introduction of additional insurance products tailored to individuals suffering from various genetic illnesses or predispositions to future disease.

  4. Experimental test and life estimation of the OLED at normal working stress based on the luminance degradation model.

    PubMed

    Zhang, J P; Wang, C; Chen, X; Cheng, G L; Qiu, Y J; Shen, M-H H

    2015-06-01

    In order to accurately acquire the life time information for the organic light emitting diode (OLED), an experiment based on the normal stress life test was carried out to gain the data for the luminance degradation tests. The luminance degradation model of OLED was established based on the Weibull function and the least square method. Combined with luminance degradation data, Weibull parameters were estimated, the qualitative and the quantitative relationship between the initial luminance and the OLED life was obtained, and the life estimation of the product was achieved. Numerical results show that the test scheme is feasible, the luminance degradation model proves to be reliable for the OLED life estimation, and the fitting accuracy is very high by comparison with the test data fluctuation. Moreover, the real life time of the OLED is measured, which can verify the validity of the assumptions used in accelerated life test methods and provide manufacturers and customers with significant guidelines.

  5. Space-flight experience and life test performance of a synthetic hydrocarbon lubricant

    NASA Technical Reports Server (NTRS)

    Bialke, Bill

    1995-01-01

    An alternative wet lubricant known as Pennzane(TM) SHF X-2000 is recommended for some spaceflight bearing systems. The performance characteristics between Pennzane(TM) SHF X-2000 and Bray 815Z were compared. The life tests showed excellent performances with continuous operation approaching three years in conservative operating environments. Space flight performance data are provided for several of the tested mechanisms which are operating in-orbit since February 1994.

  6. 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.

  7. 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…

  8. 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.…

  9. 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…

  10. 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...

  11. 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.

  12. 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).

  13. Test facility for 6000 hour life test of 30 cm mercury ion thruster

    NASA Technical Reports Server (NTRS)

    Caldwell, J. J.

    1973-01-01

    The environmental and instrumentation requirements for long term testing of electrical propulsion thrusters which impose severe and unusual requirements upon the simulation facility were studied. High speed ions ejected from a mercury thruster erode material from collecting surfaces, which is then scattered and redeposited upon other surfaces, with resultant damage to the chamber and test article. By collecting the thruster plume on a frozen mercury surface damage to the thruster and chamber by back-scattered erosion products was minimized. Provisions for unattended operation, remote data acquisition, personnel safety, and instrumentation for assessing thruster performance are also discussed.

  14. 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.

  15. 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.

  16. Accelerated life tests on a new water tree retardant insulation for power cables

    SciTech Connect

    Sarma, H.

    1997-04-01

    This paper describes the results of an investigation in which 15 kV rated cables insulated with a new water tree retardant cross-linked polyethylene (TR XLPE) were subjected to accelerated aging tests under a controlled voltage stress and thermal load cycle conditions. Cables insulated with conventional XLPE and a commercially available TR XLPE were used as reference test populations to affirm the test methodology. Under the chosen conditions, cable life of the new TR XLPE as calculated using Weibull and log normal statistical distributions, was more than twice that for the reference TRXLPE. Extensive diagnostic measurements (water content, dissipation factor, water tree analysis) were performed on failed cable samples to bring out the differences between the three insulations. Electron micrographic investigations revealed the size and distribution of micro voids in the new TR XLPE to be smaller supporting its extended life under these tests. The experimental details of the accelerated life tests are also documented in a clear manner facilitating any archival of the data for future analysis and comparison.

  17. Bayesian Analysis of Step-Stress Accelerated Life Test with Exponential Distribution

    SciTech Connect

    Lee, J.; Pan, R.

    2012-04-01

    In this article, we propose a general Bayesian inference approach to the step-stress accelerated life test with type II censoring. We assume that the failure times at each stress level are exponentially distributed and the test units are tested in an increasing order of stress levels. We formulate the prior distribution of the parameters of life-stress function and integrate the engineering knowledge of product failure rate and acceleration factor into the prior. The posterior distribution and the point estimates for the parameters of interest are provided. Through the Markov chain Monte Carlo technique, we demonstrate a nonconjugate prior case using an industrial example. It is shown that with the Bayesian approach, the statistical precision of parameter estimation is improved and, consequently, the required number of failures could be reduced.

  18. A Laser Technology Test Facility for Laser Inertial Fusion Energy (LIFE)

    SciTech Connect

    Bayramian, A J; Campbell, R W; Ebbers, C A; Freitas, B L; Latkowski, J; Molander, W A; Sutton, S B; Telford, S; Caird, J A

    2009-10-06

    A LIFE laser driver needs to be designed and operated which meets the rigorous requirements of the NIF laser system while operating at high average power, and operate for a lifetime of >30 years. Ignition on NIF will serve to demonstrate laser driver functionality, operation of the Mercury laser system at LLNL demonstrates the ability of a diode-pumped solid-state laser to run at high average power, but the operational lifetime >30 yrs remains to be proven. A Laser Technology test Facility (LTF) has been designed to specifically address this issue. The LTF is a 100-Hz diode-pumped solid-state laser system intended for accelerated testing of the diodes, gain media, optics, frequency converters and final optics, providing system statistics for billion shot class tests. These statistics will be utilized for material and technology development as well as economic and reliability models for LIFE laser drivers.

  19. 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.

  20. 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.

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

    PubMed

    Keogh, Louise A; Otlowski, Margaret F A

    2013-09-01

    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.

  2. 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

  3. Off-line life tests of Topaz-2 system reactor unit assembly units

    NASA Astrophysics Data System (ADS)

    Oglobin, Boris G.; Proshin, Yuriy F.; Shalaev, Anatoliy I.

    1995-01-01

    Experimental trials of the Topaz-2 nuclear power system (NPS) have been carried out according to the Integrated Experimental Trials Program (IETP). This program involved ground off-line tests of the reactor unit assembly units and their integrated tests as components of the prototype systems. Scopes of tests performed and major results of integrated and off-line tests were presented in the paper by Vladimir P. Nikitin et al. (1993). This paper considers major results of off-line life tests of the cesium unit, automatic control drive, ionization chamber suspension and dry friction pairs. These tests have been carried out in the Central Design Bureau for Machine Building (CDBMB) between 1982 and April, 1994.

  4. Reproducibility of a life-cycle toxicity test with Daphnia magna

    SciTech Connect

    Parkhurst, B.R.; Forte, J.L.; Wright, G.P.

    1981-01-01

    Standardized chronic life-cycle toxicity testing procedures for aquatic species are described. The reproducibility of chronic toxicity and points using the static-renewal method with Daphnia magna are investigated. The objectives were to determine if the lowest rejected concentrations tested (LRCTs) obtained for six different toxicity criteria in static-renewal tests with acridine were reproducible over time and to determine the relative sensitivity and variability of the toxicity criteria. Two of the six toxicity criteria, numbers of young per brood and the young produced per female, were found to be reliable and sensitive for estimating the LRCT for acridine to D. magna. (RJC)

  5. The Role of Bearing and Scan Mechanism Life Testing in Flight Qualification of the MODIS Instrument

    NASA Technical Reports Server (NTRS)

    VanDyk, Steven G.; Dietz, Brian J.; Street, Kenneth W.; Jones, William R., Jr.; Jansen, Mark J.; Dube, Michael J.; Sharma, Rajeev K.; Predmore, Roamer E.

    2001-01-01

    This paper describes the results of accelerated and operational life tests on bearings for the Moderate Resolution Imaging Spectroradiometer (MODIS). It also describes the post test analysis of the disassembled bearings. Analysis was performed using micro-Raman, micro-FTIR, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), and Size Exclusion Chromatography (SEC). In general, the three sets of bearings in each of three test stations were in very good condition after accumulating 68, 144, and 209 million cycles, respectively. Some of the bearings exhibited lubricant degradation, indicated by viscous lubricant deposits on the cage and raceways.

  6. 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

  7. 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

  8. Developing and testing an operational framework for assessing quality of life

    SciTech Connect

    Fahy, F. O Cinneide, M.

    2008-08-15

    Difficulties with operationalising the concept of sustainable development have generated much debate, and have stimulated a good deal of research on the challenging task of assessing progress towards that goal. This paper focuses on quality of life, as one discourse in the sustainable development literature, and reports on the development and testing of an operational framework for the assessment of quality of life in an urban setting. Core principles of sustainable development are translated into a set of operational criteria for investigating quality of life. The process of formulating these criteria and the manner in which they may be linked to policy and practice are outlined. The application of the framework is demonstrated by reference to the experience of implementing it in an urban centre in Ireland.

  9. 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.

  10. 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.

  11. Grease test system for improved life of ball and roller bearings

    SciTech Connect

    Kleinlein, E. )

    1992-12-01

    An earlier developed system (FE9) for mechanodynamical testing of lubricating greases for ball and rolling bearings was used to assess, at temperatures between 100 and 200 C, grease lives of the following lubricating greases used in this test system: a standard grease, lithium soap, NLGI class 3 grease, a special grease for high temperatures, and a special grease not suitable for high temperatures. The paper describes the design of FE9 tester, the test rig, the test procedure, and the results of evaluation. It was found that lowering the test temperature led to a steeper increase of the grease life. Starved lubrication was found to be the major cause of failure at moderate temperatures, especially at the areas of sliding motion, such as betweeen cage and the rolling element. 9 refs.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Development of Probabilistic Life Prediction Methodologies and Testing Strategies for MEMS

    NASA Technical Reports Server (NTRS)

    Jadaan, Osama M.

    2003-01-01

    This effort is to investigate probabilistic life prediction methodologies for MicroElectroMechanical Systems (MEMS) and to analyze designs that determine stochastic properties of MEMS. This includes completion of a literature survey regarding Weibull size effect in MEMS and strength testing techniques. Also of interest is the design of a proper test for the Weibull size effect in tensile 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. Another potential item of interest is analysis and modeling of material interfaces for strength as well as developing a strategy to handle stress singularities at sharp corners, filets, and material interfaces. The ultimate objective of this effort is to further develop and verify the ability of the Ceramics Analysis and Reliability Evaluation of Structuredlife (CARES/Life) code to predict the time-dependent reliability of MEMS structures subjected to multiple transient loads. Along these lines work may also be performed on transient fatigue life prediction methodologies.

  18. The effects of testing methods on the flexural fatigue life of human cortical bone.

    PubMed

    Griffin, L V; Gibeling, J C; Martin, R B; Gibson, V A; Stover, S M

    1999-01-01

    A flexural model of four-point bending fatigue that has been experimentally validated for human cortical bone under load control was used to determine how load and displacement control testing affects the fatigue behavior of human cortical bone in three-point and symmetric four-point bending. Under load control, it was predicted that three-point bending produced no significant differences in fatigue life when compared to four-point bending. However, three-point bending produced less stiffness loss with increasing cycles than four-point bending. In four-point bending, displacement control was predicted to produce about one and a half orders of magnitude greater fatigue life when compared to load control. This prediction agrees with experimental observations of equine cannon bone tested in load and displacement control (Gibson et al., 1998). Displacement controlled three-point bending was found to produce approximately a 25% greater fatigue life when compared to load control. The prediction of longer fatigue life under displacement control may have clinical relevance for the repair of damaged bone. The model can also be adapted to other geometric configurations, including modeling of whole long bones, and with appropriate fatigue data, other cortical bone types.

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

    PubMed Central

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

    2015-01-01

    Introduction 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. Objective To compare and correlate a novel high-fidelity simulation-based evaluation with traditional written testing for senior medical students in an ACLS course. Methods 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. Results 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. Conclusion 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. PMID:26594288

  20. "Cancer in the family" and genetic testing: implications for life insurance.

    PubMed

    Lynch, Elly L; Doherty, Rebecca J; Gaff, Clara L; Macrae, Finlay A; Lindeman, Geoffrey J

    2003-11-01

    The potential for discrimination when applying for insurance can be of concern for individuals with a family history of cancer or of a genetic disorder and who are considering genetic counselling or genetic testing. The actual incidence of "genetic discrimination", however, is not known, despite considerable media coverage of this issue. The clinical details required by insurers have received less attention. We obtained primary application and personal statement forms used by 21 different underwriters of voluntary life insurance and found substantial differences in the information requested about family history and genetic testing. All insurance applications, however, contained a duty of disclosure that would require revealing the result, if known by the applicant, of a genetic test in a family member. Therefore, decisions made by family members can affect insurance applications, and people considering genetic testing may also need to consider the implications of the results for other family members. Health practitioners should balance the potential benefits of appropriate genetic testing against potential restriction to life and income-protection insurance when advising people about genetic testing.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Life and stability testing of packaged low-cost energy storage materials

    NASA Technical Reports Server (NTRS)

    Frysinger, G. R.

    1980-01-01

    Thermal cycling and performance tests, performed to verify the package integrity, life, and stability of the chub packaged materials system for storage coolness with application to residential air conditioning, are described. The moisture vapor retention characteristics of the laminate film for long term chub performance was determined. The stability, mechanical integrity, and thermal performance of chubs following mechanical shock, vibration, and temperature extremes is reported.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

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

    PubMed

    Powell, Daniel J; Schlotz, Wolff

    2012-01-01

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

  19. 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.

  20. Factors affecting toxicity test endpoints in sensitive life stages of native Gulf of Mexico species.

    PubMed

    Echols, B S; Smith, A J; Rand, G M; Seda, B C

    2015-05-01

    Indigenous species are less commonly used in laboratory aquatic toxicity tests compared with standard test species due to (1) limited availability lack of requisite information necessary for their acclimation and maintenance under laboratory conditions and (2) lack of information on their sensitivity and the reproducibility of toxicity test results. As part of the Natural Resource Damage Assessment aquatic toxicity program in response to the Deepwater Horizon Oil incident (2010), sensitive life stages of native Gulf of Mexico species were evaluated in laboratory toxicity tests to determine the potential effects of the spill. Fish (n = 5) and invertebrates (n = 2) selected for this program include the following: the Florida pompano (Trachinotus carolinus), red drum (Sciaenops ocellatus), spotted sea trout (Cynoscion nebulosus), cobia (Rachycentron canadum), red porgy (Pagrus pagrus), blue crab (Callinectes sapidus), and the common moon jellyfish (Aurelia aurita). Initially in the program, to establish part of the background information, acute tests with reference toxicants (CdCl2, KCl, CuSO4) were performed with each species to establish data on intraspecies variability and test precision as well as identify other factors that may affect toxicity results. Median lethal concentration (LC50) values were calculated for each acute toxicity test with average LC50 values ranging from 248 to 862 mg/L for fish exposures to potassium chloride. Variability between test results was determined for each species by calculating the coefficient of variation (%CV) based on LC50 values. CVs ranged from 11.2 % for pompano (96-h LC50 value) to 74.8 % for red porgy 24-h tests. Cadmium chloride acute toxicity tests with the jellyfish A. aurita had the lowest overall CV of 3.6 %. By understanding acute toxicity to these native organisms from a compound with known toxicity ranges and the variability in test results, acute tests with nonstandard species can be better interpreted and used

  1. Factors affecting toxicity test endpoints in sensitive life stages of native Gulf of Mexico species.

    PubMed

    Echols, B S; Smith, A J; Rand, G M; Seda, B C

    2015-05-01

    Indigenous species are less commonly used in laboratory aquatic toxicity tests compared with standard test species due to (1) limited availability lack of requisite information necessary for their acclimation and maintenance under laboratory conditions and (2) lack of information on their sensitivity and the reproducibility of toxicity test results. As part of the Natural Resource Damage Assessment aquatic toxicity program in response to the Deepwater Horizon Oil incident (2010), sensitive life stages of native Gulf of Mexico species were evaluated in laboratory toxicity tests to determine the potential effects of the spill. Fish (n = 5) and invertebrates (n = 2) selected for this program include the following: the Florida pompano (Trachinotus carolinus), red drum (Sciaenops ocellatus), spotted sea trout (Cynoscion nebulosus), cobia (Rachycentron canadum), red porgy (Pagrus pagrus), blue crab (Callinectes sapidus), and the common moon jellyfish (Aurelia aurita). Initially in the program, to establish part of the background information, acute tests with reference toxicants (CdCl2, KCl, CuSO4) were performed with each species to establish data on intraspecies variability and test precision as well as identify other factors that may affect toxicity results. Median lethal concentration (LC50) values were calculated for each acute toxicity test with average LC50 values ranging from 248 to 862 mg/L for fish exposures to potassium chloride. Variability between test results was determined for each species by calculating the coefficient of variation (%CV) based on LC50 values. CVs ranged from 11.2 % for pompano (96-h LC50 value) to 74.8 % for red porgy 24-h tests. Cadmium chloride acute toxicity tests with the jellyfish A. aurita had the lowest overall CV of 3.6 %. By understanding acute toxicity to these native organisms from a compound with known toxicity ranges and the variability in test results, acute tests with nonstandard species can be better interpreted and used

  2. 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.

  3. 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. PMID:19643385

  4. A life test of a 22-Newton (5-lbf) hydrazine rocket

    NASA Technical Reports Server (NTRS)

    Meng, P. R.; Schneider, S. J.; Morgan, C. J.; Jones, R. E.; Pahl, D. A.

    1987-01-01

    Life tests were conducted on a 22-N (5-lb) hydrazine rocket thruster which incorporates the latest technology to obtain long life from the catalyst bed. A spring mechanism surrounding the catalyst bed continually applies compression to the catalyst bed to prevent the formation of any void channels. The research rocket thruster was tested over an operational cycle of both steady state and pulse firing which simulated a possible space station duty cycle. The thruster ran as expected for about 40 hours, or 3.2 times 10 to the 6th power N-sec (7.2 times 10 to the 5th power lb-sec) total impulse. Subsequently, some thrust chamber pressure decreases were noted during long steady state test periods. After 60.2 hours of run time, tests had to be terminated due to a blockage in the propellant injector tube which occurred during heating of the thruster by a heat lamp. A chemical analysis of the catalyst indicated that iron and nickel metals had poisoned some of the catalyst, thereby causing a degradation in performance. It was determined that a contaminated barrel of hydrazine was the source of the metal poisoning.

  5. 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.

  6. 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.

  7. 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.

  8. Testing the applicability of a model of oral health-related quality of life.

    PubMed

    Santos, Camila Mello Dos; Celeste, Roger Keller; Hilgert, Juliana Balbinot; Hugo, Fernando Neves

    2015-09-01

    The aim of this study was to test Wilson & Cleary's conceptual model of the direct and mediated pathways between clinical and non-clinical variables in relation to oral health-related quality of life. A random sample of 578 older people was evaluated. Wilson & Cleary's conceptual model was tested using structural equations modeling including: biological variables, symptom status, functional health, oral health perceptions, oral health-related quality of life. Oral health-related quality of life was assessed with the Oral Health Impact Profile-14 (OHIP-14). In the final model, edentulism was negatively correlated to dissatisfaction of appearance of their dental prostheses (r = -0.25). Worse functional status was correlated with poor oral health perception (r = 0.24). Being aged over 68 (r = 0.25), being a female (r = 0.39) and living in rural areas (r = 0.15) had a direct effect on the edentulism. Age had a direct effect on OHIP-14 (r = -0.15). There was an indirect effect of sex on OHIP-14 via functional status (r = 0.12). The present findings partially support Wilson & Cleary's model framework.

  9. 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

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. Accelerated cable life testing of EPR-insulated medium voltage distribution cables

    SciTech Connect

    Walton, M.D. ); Bernstein, B.S. ); Smith, J.T. III ); Thue, W.A. , Stuart, FL ); Groeger, J.H. )

    1994-07-01

    This paper presents results aimed at developing a reliable accelerated aging tank test for EPR-insulated cables. Aging was performed at 2 to 4 times rated voltage on load cycling to temperatures of 45 C, 60 C, 75 C, and 90 C at the conductor with water in the conductor strands and outside the cable. Results show that cable failure is more rapid at the highest electrical stress and lowest conductor load cycle temperature. Cables aged at higher temperatures and various levels of electrical stress rarely failed and retained in excess of 40% of their original breakdown strength after 1,500+ days of aging. Aging performed at 90 C load cycle temperature and 4 times rated voltage with air on the outside and water at the conductor of the cable showed more rapid loss of life than with water outside. Results indicate the optimum aging conditions for EPR-insulated cables in the accelerated cable life test (ACLT) differ significantly from those previously observed for XLPE-insulated cables, and that the appropriate test methodology for EPR-insulated cables requires additional study.

  15. 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

  16. 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.

  17. 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...

  18. 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

  19. Exercise testing in severe emphysema: association with quality of life and lung function.

    PubMed

    Brown, Cynthia D; Benditt, Joshua O; Sciurba, Frank C; Lee, Shing M; Criner, Gerard J; Mosenifar, Zab; Shade, David M; Slivka, William A; Wise, Robert A

    2008-04-01

    Six-minute walk testing (6MWT) and cardiopulmonary exercise testing (CPX) are used to evaluate impairment in emphysema. However, the extent of impairment in these tests as well as the correlation of these tests with each other and lung function in advanced emphysema is not well characterized. During screening for the National Emphysema Treatment Trial, maximum ergometer CPX and 6MWT were performed in 1,218 individuals with severe COPD with an average FEV(1) of 26.9 +/- 7.1 % predicted. Predicted values for 6MWT and CPX were calculated from reference equations. Correlation coefficients and multivariable regression models were used to determine the association between lung function, quality of life (QOL) scores, and exercise measures. The two forms of exercise testing were correlated with each other (r = 0.57, p < 0.0001). However, the impairment of performance on CPX was greater than on the 6MWT (27.6 +/- 16.8 vs. 67.9 +/- 18.9 % predicted). Both exercise tests had similar correlation with measures of QOL, but maximum exercise capacity was better correlated with lung function measures than 6-minute walk distance. After adjustment, 6MWD had a slightly greater association with total SGRQ score than maximal exercise (effect size 0.37 +/- 0.04 vs. 0.25 +/- 0.03 %predicted/unit). Despite advanced emphysema, patients are able to maintain 6MWD to a greater degree than maximum exercise capacity. Moreover, the 6MWT may be a better test of functional capacity given its greater association with QOL measures whereas CPX is a better test of physiologic impairment.

  20. Accelerated Life Structural Benchmark Testing for a Stirling Convertor Heater Head

    NASA Astrophysics Data System (ADS)

    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-watt 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.

  1. Accelerated Life Structural Benchmark Testing for a Stirling Convertor Heater Head

    SciTech Connect

    Krause, David L.; Kantzos, Pete T.

    2006-01-20

    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-watt 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.

  2. 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.

  3. 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.

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

    SciTech Connect

    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 for ``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.

  5. Cooperative breeding in birds: a comparative test of the life history hypothesis

    PubMed Central

    Arnold, K. E.; Owens, I. P. F.

    1998-01-01

    In approximately 3.2% of bird species individuals regularly forgo the opportunity to breed independently and instead breed cooperatively with other conspecifics, either as non-reproductive 'helpers' or as co-breeders. The traditional explanation for cooperative breeding is that the opportunities for breeding independently are limited owing to peculiar features of the species' breeding ecology. However, it has proved remarkably difficult to find any common ecological correlates of cooperative breeding in birds. This difficulty has led to the 'life history hypothesis', which suggests that the common feature of cooperatively breeding birds is their great longevity, rather than any particular feature of their breeding ecology. Here, we use a comparative method to test the life history hypothesis by looking for correlations between life history variation and variation in the frequency of cooperative breeding. First, we find that cooperative breeding in birds is not randomly distributed, but concentrated in certain families, thus supporting the idea that there may be a common basis to cooperative breeding in birds. Second, increases in the level of cooperative breeding are strongly associated with decreases in annual adult mortality and modal clutch size. Third, the proportion of cooperatively breeding species per family is correlated with a low family-typical value of annual mortality, suggesting that low mortality predisposes cooperative breeding rather than vice versa. Finally, the low rate of mortality typically found in cooperatively breeding species is associated with increasing sedentariness, lower latitudes, and decreased environmental fluctuation. We suggest that low annual mortality is the key factor that predisposes avian lineages to cooperative breeding, then ecological changes, such as becoming sedentary, further slow population turnover and reduce opportunities for independent breeding. As the traditional explanation suggests, the breeding habitat of

  6. Fan Performance Testing and Oxygen Compatibility Assessment Results for Future Space Suit Life Support Systems

    NASA Technical Reports Server (NTRS)

    Jennings, Mallory A.; Paul, Heather L.; Vogel, Matthew

    2008-01-01

    An advanced portable life support system (PLSS) for the space suit will require a small, robust, and energy-efficient system to transport the ventilation gas through the space suit for lunar Extravehicular Activity (EVA) operations. A trade study identified and compared ventilation transport technologies in commercial, military, and space applications to determine which technologies could be adapted for EVA use. Based on the trade study results, five commercially available, 24volt fans were selected for performance testing at various pressures and flow rates. Measured fan parameters included fan delta-pressures, input voltages, input electrical currents, and in some cases motor windings electrical voltages and currents. In addition, a follow-on trade study was performed to identify oxygen compatibility issues and assess their impact on fan design. This paper outlines the results of the fan performance characterization testing, as well as the results from the oxygen compatibility assessment.

  7. Fan Performance Testing and Oxygen Compatibility Assessment Results for Future Space Suit Life Support Systems

    NASA Technical Reports Server (NTRS)

    Paul, Heather L.; Jennings, Mallory A.; Vogel, Matthew

    2009-01-01

    An advanced portable life support system (PLSS) for the space suit will require a small, robust, and energyefficient system to transport the ventilation gas through the space suit for lunar Extravehicular Activity (EVA) operations. A trade study identified and compared ventilation transport technologies in commercial, military, and space applications to determine which technologies could be adapted for EVA use. Based on the trade study results, five commercially available, 24-volt fans were selected for performance testing at various pressures and flow rates. Measured fan parameters included fan delta-pressures, input voltages, input electrical currents, and in some cases motor windings electrical voltages and currents. In addition, a follow-on trade study was performed to identify oxygen compatibility issues and assess their impact on fan design. This paper outlines the results of the fan performance characterization testing, as well as the results from the oxygen compatibility assessment.

  8. Genetic testing for inherited heart diseases: longitudinal impact on health-related quality of life.

    PubMed

    Ingles, Jodie; Yeates, Laura; O'Brien, Lisa; McGaughran, Julie; Scuffham, Paul A; Atherton, John; Semsarian, Christopher

    2012-05-03

    Purpose:A genetic diagnosis is an extremely useful tool in the management and care of families with inherited heart diseases, particularly in allowing clarification of risk status of asymptomatic family members. The psychosocial consequences of genetic testing in this group are poorly understood. This longitudinal pilot study sought to determine changes in health-related quality of life in patients and asymptomatic family members undergoing genetic testing for inherited heart diseases.Methods:Individuals attending two specialized multidisciplinary cardiac genetic clinics in Australia were invited to participate. Patients undergoing proband or predictive genetic testing for an inherited cardiomyopathy or primary arrhythmogenic disorder were eligible. The Medical Outcomes Short Form-36 (version 2) was administered before the genetic result was given, and follow-up surveys were completed 1-3, 6, and 12 months after the result was given.Results:A total of 54 individuals with hypertrophic cardiomyopathy, familial dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, and long QT syndrome completed baseline and at least one follow-up survey, including 33 probands and 21 asymptomatic relatives. Physical and mental component scores analyzed at baseline and 1-3 months were found to be unchanged in all groups. Furthermore, no significant differences were observed up to 12 months after result.Conclusion:In this longitudinal pilot study, no change in health-related quality of life was observed up to 12 months after the result was given in patients and their asymptomatic family members undergoing genetic testing for an inherited heart disease.Genet Med 2012 advance online publication 3 May 2012.

  9. 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.

  10. 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

  11. A review of quality of life after predictive testing for and earlier identification of neurodegenerative diseases.

    PubMed

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

    2013-11-01

    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 toward 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

  12. The effect of laser glazing on life of ZrO2 TBCs in cyclic burner rig tests

    NASA Technical Reports Server (NTRS)

    Zaplatynsky, I.

    1986-01-01

    The performance of laser glazed zirconia (containing 8 wt% Y2O3) TBC's was evaluated in burner rig cyclic oxidation tests at 1000 and 1050 C. It was found that the cycle duration has no effect on life of TBC's and that the increase in thickness of the glazed layer caused a slight reduction in life.

  13. 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…

  14. 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.

  15. 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

  16. Quantity of 135I released from the AGR-1, AGR-2, and AGR-3/4 experiments and discovery of 131I at the FPMS traps during the AGR-3/4 experiment

    SciTech Connect

    Scates, Dawn M.

    2014-09-01

    A series of three Advanced Gas Reactor (AGR) experiments have been conducted in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL). From 2006 through 2014, these experiments supported the development and qualification of the new U.S. tristructural isotropic (TRISO) particle fuel for Very High Temperature Reactors (VHTR). Each AGR experiment consisted of multiple fueled capsules, each plumbed for independent temperature control using a mix of helium and neon gases. The gas leaving a capsule was routed to individual Fission Product Monitor (FPM) detectors. For intact fuel particles, the TRISO particle coatings provide a substantial barrier to fission product release. However, particles with failed coatings, whether because of a minute percentage of initially defective particles, those which fail during irradiation, or those designed to fail (DTF) particles, can release fission products to the flowing gas stream. Because reactive fission product elements like iodine and cesium quickly deposit on cooler capsule components and piping structures as the effluent gas leaves the reactor core, only the noble fission gas isotopes of Kr and Xe tend to reach FPM detectors. The FPM system utilizes High Purity Germanium (HPGe) detectors coupled with a thallium activated sodium iodide NaI(Tl) scintillator. The HPGe detector provides individual isotopic information, while the NaI(Tl) scintillator is used as a gross count rate meter. During irradiation, the 135mXe concentration reaching the FPM detectors is from both direct fission and by decay of the accumulated 135I. About 2.5 hours after irradiation (ten 15.3 minute 135mXe half lives) the directly produced 135mXe has decayed and only the longer lived 135I remains as a source. Decay systematics dictate that 135mXe will be in secular equilibrium with its 135I parent, such that its production rate very nearly equals the decay rate of the

  17. Predicting in-service fatigue life of flexible pavements based on accelerated pavement testing

    NASA Astrophysics Data System (ADS)

    Guo, Runhua

    Pavement performance prediction in terms of fatigue cracking and surface rutting are essential for any mechanistically-based pavement design method. Traditionally, the estimation of the expected fatigue field performance has been based on the laboratory bending beam test. Full-scale Accelerated Pavement Testing (APT) is an alternative to laboratory testing leading to advances in practice and economic savings for the evaluation of new pavement configurations, stress level related factors, new materials and design improvements. This type of testing closely simulates field conditions; however, it does not capture actual performance because of the limited ability to address long-term phenomena. The same pavement structure may exhibit different response and performance under APT than when in-service. Actual field performance is better captured by experiments such as Federal Highway Administration's Long-Term Pavement Performance (LTPP) studies. Therefore, to fully utilize the benefits of APT, there is a need for a methodology to predict the long-term performance of in-service pavement structures from the results of APT tests that will account for such differences. Three models are generally suggested to account for the difference: shift factors, statistical and mechanistic approaches. A reliability based methodology for fatigue cracking prediction is proposed in this research, through which the three models suggested previously are combined into one general approach that builds on their individual strengths to overcome some of the shortcomings when the models are applied individually. The Bias Correction Factor (BCF) should account for all quantifiable differences between the fatigue life of the pavement site under APT and in-service conditions. In addition to the Bias Correction Factor, a marginal shifty factor, M, should be included to account for the unquantifiable differences when predicting the in-service pavement fatigue life from APT. The Bias Correction Factor

  18. Hybrid Electric Vehicle End-Of-Life Testing On Honda Insights, Gen I Civics And Toyota Gen I Priuses

    SciTech Connect

    James Francfort; Donald Karner; Ryan Harkins; Joseph Tardiolo

    2006-02-01

    This technical report details the end-of-life fuel efficiency and battery testing on two model year 2001 Honda Insight hybrid electric vehicles (HEVs), two model year 2003 Honda Civic HEVs, and two model year 2002 Toyota Prius HEVs. The end-of-life testing was conducted after each vehicle has been operated for approximately 160,000 miles. This testing was conducted by the U.S. Department of Energy’s (DOE) Advanced Vehicle Testing Activity (AVTA). The AVTA is part of DOE’s FreedomCAR and Vehicle Technologies Program. SAE J1634 fuel efficiency testing was performed on the six HEVs with the air conditioning (AC) on and off. The AC on and off test results are compared to new vehicle AC on and off fuel efficiencies for each HEV model. The six HEVs were all end-of-life tested using new-vehicle coast down coefficients. In addition, one of each HEV model was also subjected to fuel efficiency testing using coast down coefficients obtained when the vehicles completed 160,000 miles of fleet testing. Traction battery pack capacity and power tests were also performed on all six HEVs during the end-of-life testing in accordance with the FreedomCAR Battery Test Manual For Power-Assist Hybrid Electric Vehicles procedures. When using the new-vehicle coast down coefficients (Phase I testing), 11 of 12 HEV tests (each HEV was tested once with the AC on and once with the AC off) had increases in fuel efficiencies compared to the new vehicle test results. The end-of-life fuel efficiency tests using the end-of-life coast down coefficients (Phase II testing) show decreases in fuel economies in five of six tests (three with the AC on and three with it off). All six HEVs experienced decreases in battery capacities, with the two Insights having the highest remaining capacities and the two Priuses having the lowest remaining capacities. The AVTA’s end-of-life testing activities discussed in this report were conducted by the Idaho National Laboratory; the AVTA testing partner Electric

  19. Life Satisfaction in Brazil: Testing the Psychometric Properties of the Satisfaction with Life Scale (SWLS) in Five Brazilian Samples

    ERIC Educational Resources Information Center

    Gouveia, Valdiney V.; Milfont, Taciano L.; da Fonseca, Patricia Nunes; Coelho, Jorge Artur Pecanha de Miranda

    2009-01-01

    The aim of this paper was to validate the Brazilian-Portuguese version of the Satisfaction With Life Scale (SWLS), presenting evidence of its reliability and construct and criterion-related validity. A large Brazilian sample (2,180 participants), from five different populations (undergraduate and high school students, general population,…

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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). Participants completed the…

  6. Testing the Validity of the Implicit Relational Assessment Procedure and the Implicit Association Test: Measuring Attitudes toward Dublin and Country Life in Ireland

    ERIC Educational Resources Information Center

    Barnes-Holmes, Dermot; Waldron, Deirdre; Barnes-Holmes, Yvonne; Stewart, Ian

    2009-01-01

    The current study aimed to test the validity of the Implicit Relational Assessment Procedure (IRAP), as compared to the Implicit Association Test (IAT), by assessing the attitudes of Dublin dwellers and rural dwellers toward Dublin and country life. Discrimination between the two groups for the IAT was marginally significant. The IRAP…

  7. The K-factor, Covitality, and personality : A Psychometric Test of Life History Theory.

    PubMed

    Figueredo, Aurelio José; Vásquez, Geneva; Brumbach, Barbara Hagenah; Schneider, Stephanie M R

    2007-03-01

    We present a psychometric test of life history theory as applied to human individual differences using MIDUS survey data (Brim et al. 2000). Twenty scales measuring cognitive and behavioral dimensions theoretically related to life history strategy were constructed using items from the MIDUS survey. These scales were used to construct a single common factor, the K-factor, which accounted for 70% of the reliable variance. The scales used included measures of personal, familial, and social function. A second common factor, Covitality, was constructed from scales for physical and mental health. Finally, a single general factor, Personality, was constructed from scales for the "Big Five" factors of personality. The K-factor, covitality factor, and general personality factor correlated significantly with each other, supporting the prediction that high K predicts high somatic effort and also manifests in behavioral display. Thus, a single higher-order common factor, the Super-K factor, was constructed that consisted of the K-factor, covitality factor, and personality factor.

  8. 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.

  9. The Role of Bearing and Scan Mechanism Life Testing in Flight Qualification of the MODIS Instrument

    NASA Technical Reports Server (NTRS)

    VanDyk, Steven G.; Dietz, Brian J.; Street, Kenneth W.; Jones, William R., Jr.; Jansen, Mark J.; Dube, Michael; Sharma, Rajeev; Predmore, Roamer E.

    2001-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) is an instrument aboard the Terra (EOS AM-1) satellite and has been operating successfully since December 1999. MODIS has been viewing the entire Earth's surface and gathering data to better understand the global dynamics and processes occurring on land, in the oceans, and in the lower atmosphere. All observations are made through an extremely high resolution, optically and mechanically precise, scan mirror motor/encoder assembly. The reliable performance of this assembly depends on two duplex bearing pairs lubricated with Pennzane, a synthetic hydrocarbon, formulated with lead napthanate. This paper describes the results of accelerated and operational life tests. It also describes the post-test analyses of the disassembled bearings. Analyses were performed using micro-Raman, micro-FTIR, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), and Size Exclusion Chromatography (SEC). In general, the three sets of bearings in each of the test stations were in very good condition after accumulating 68, 144, and 209 million revolutions, respectively. Some of the bearings exhibited lubricant degradation, indicated by viscous lubricant deposits on the cage and raceways.

  10. The Role of Bearing and Scan Mechanism Life Testing in Flight Qualification of the MODIS Instrument

    NASA Technical Reports Server (NTRS)

    VanDyk, Steven G.; Street, Kenneth W.; Jones, William R., Jr.; Jansen, Mark J.; Sharma, Rajeev; Predmore, Roamer E.; Dietz, Brian J.; Dube, Michael

    2001-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) is an instrument aboard the Terra (EOS AM-11) satellite and has been operating successfully since December 1999. MODIS has been viewing the entire Earth's surface and gathering data to better understand the global dynamics and processes occurring on land, in the oceans, and in the lower atmosphere. All observations are made through an extremely high resolution, optically and mechanically precise, scan mirror motor/encoder assembly. The reliable performance of this assembly depends on two duplex bearing pairs lubricated with Pennzane, a synthetic hydrocarbon, formulated with lead napthanate. This paper describes the results of accelerated and operational life tests. It also describes the post-test analyses of the disassembled bearings. Analyses were performed using micro-Raman, micro-FTIR, X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy (SEM), and Size Exclusion Chromatography (SEC). In general, the three sets of bearings in each of the test stations were in very good condition after accumulating 68, 144, and 209 million revolutions, respectively. Some of the bearings exhibited lubricant degradation, indicated by viscous lubricant deposits on the cage and raceways.

  11. Empirical-Statistics Analysis for Zero-Failure GaAs MMICs Life Testing Data

    NASA Astrophysics Data System (ADS)

    Huang, Zheng-Liang; Yu, Fa-Xin; Zhang, Shu-Ting; Luo, Hao; Wang, Ping-Hui; Zheng, Yao

    GaAs MMICs (Monolithic Microwave Integrated Circuits) reliability is a critical part of the overall reliability of the thermal solution in semiconductor devices. With MMICs reliability improved, GaAs MMICs failure rates will reach levels which are impractical to measure with conventional methods in the near future. This letter proposes a methodology to predict the GaAs MMICs reliability by combining empirical and statistical methods based on zero-failure GaAs MMICs life testing data. Besides, we investigate the effect of accelerated factors on MMICs degradation and make a comparison between the Weibull and lognormal distributions. The method has been used in the reliability evaluation of GaAs MMICs successfully.

  12. Life test performance of a Philips rhombic-drive refrigerator with bellows seals

    NASA Technical Reports Server (NTRS)

    Lindale, E.; Lehrfeld, D.

    1983-01-01

    In February 1979, tour Stirling cycle cryogenic refrigerators, developed by Philips Laboratories for the John Hopkins University/Applied Physics Laboratory, were launched into orbit aboard the P78-1 spacecraft. The refrigerators were designed to cool the detectors of two identical gamma-ray spectrometers to 77 K reliably for one year. Since launch, the refrigerators, still in orbit, have individually accumulated from 5,000 to over 20,000 hours of operation. As part of those efforts, a refrigerator identical to those in orbit was built, with one significant modification: flexible metal bellows between the crankcase and the working volume to prevent possible contaminants from migrating into the cold region. During the life test of the modified refrigerator, the temperature increase during the first three month run was 0.022 k/day, a negligible level. As of October 1982, the unit has accumulated over 12,300 hours of operation.

  13. Random Vibration Tests for Prediction of Fatigue Life of Diffuser Structure for Gas Dynamic Laser

    NASA Astrophysics Data System (ADS)

    Maurer, O. F.; Banaszak, D. L.

    1980-01-01

    Static and dynamic strain measurements which were taken during test stand operations of the gas dynamic laser (GDL) for the AF Airborne Laser Laboratory indicated that higher than expected vibrational stress levels may possibly limit the fatigue life of the laser structure. Particularly the diffuser sidewall structure exhibited large amplitude random vibrations which were excited by the internal gas flow. The diffuser structure consists of two layers of brazed stainless steel, AISI-347, panels. Cooling ducts were milled into the outer face sheet. These in turn are backed by the inner face sheet. So called T-rail stiffeners silver-brazed to the outer face sheets add the required stiffness and divide the sidewall into smaller rectangular plate sections.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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 ...

  19. Performance and cycle life test results of a PEVE first-generation prismatic nickel/metal-hydride battery pack

    NASA Astrophysics Data System (ADS)

    Potter, B. G.; Duong, T. Q.; Bloom, I.

    A first-generation, prismatic, nickel/metal-hydride battery pack from Panasonic EV Energy Company Ltd. (PEVE) was characterized following the standard PNGV test procedures and then cycle life tested at 25 °C. The pack met, or exceeded, PNGV power and energy goals at the beginning of life. After more than 500,000 cycles, the data for capacity and discharge pulse power capability showed no measurable fade; similarly, discharge pulse resistance at 60% DOD also showed no measurable change. After the same pack was tested with two size factors, it still met or exceeded the PNGV goals.

  20. Accelerated Life Testing and Service Lifetime Prediction for PV Technologies in the Twenty-First Century

    SciTech Connect

    Czanderna, A. W.; Jorgensen, G. J.

    1999-07-13

    The purposes of this paper are to (1) discuss the necessity for conducting accelerated life testing (ALT) in the early stages of developing new photovoltaic (PV) technologies, (2) elucidate the crucial importance for combining ALT with real-time testing (RTT) in terrestrial environments for promising PV technologies for the 21st century, and (3) outline the essential steps for making a service lifetime prediction (SLP) for any PV technology. The specific objectives are to (a) illustrate the essential need for ALT of complete, encapsulated multilayer PV devices, (b) indicate the typical causes of degradation in PV stacks, (c) elucidate the complexity associated with quantifying the durability of the devices, (d) explain the major elements that constitute a generic SLP methodology, (e) show how the introduction of the SLP methodology in the early stages of new device development can reduce the cost of technology development, and (f) outline the procedure for combining the results of ALT and RTT, establishing degradation mechanisms, using sufficient numbers of samples, and applying the SLP methodology to produce a SLP for existing or new PV technologies.

  1. Nickel-Hydrogen Battery Cell Life Test Program Update for the International Space Station

    NASA Technical Reports Server (NTRS)

    Miller, Thomas B.

    2000-01-01

    NASA and Boeing North America are responsible for constructing the electrical power system for the International Space Station (ISS), which circles the Earth every 90 minutes in a low Earth orbit (LEO). For approximately 55 minutes of this orbit, the ISS is in sunlight, and for the remaining 35 minutes, the ISS is in the Earth s shadow (eclipse). The electrical power system must not only provide power during the sunlight portion by means of the solar arrays, but also store energy for use during the eclipse. Nickel-hydrogen (Ni/H2) battery cells were selected as the energy storage systems for ISS. Each battery Orbital Replacement Unit (ORU) comprises 38 individual series-connected Ni/H2 battery cells, and there are 48 battery ORU s on the ISS. On the basis of a limited Ni/H2 LEO data base on life and performance characteristics, the NASA Glenn Research Center at Lewis Field commenced testing through two test programs: one in-house and one at the Naval Surface Warfare Center in Crane, Indiana.

  2. 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

  3. Abandoning the common law: medical negligence, genetic tests and wrongful life in the Australian High Court.

    PubMed

    Faunce, Thomas; Jefferys, Susannah

    2007-05-01

    The Australian High Court recently found that the common law could allow parents to claim tortious damages when medical negligence was proven to have led to the birth of an unplanned, but healthy, baby (Cattanach v Melchior (2003) 215 CLR 1). In Harriton v Stephens (2006) 80 ALJR 791; [2006] HCA 15 and Waller v James; Waller v Hoolahan (2006) 80 ALJR 846; [2006] HCA 16 the High Court in a six-to-one decision (Kirby J dissenting) decided that no such claim could be made by a child when medical negligence in failing to order an in utero genetic test caused the child severe disability. In an era when almost all pregnancies will soon require patented fetal genetic tests as part of the professional standard of care, the High Court, by barring so-called "wrongful life" (better termed "wrongful suffering") claims, may have created a partial immunity from suit for their corporate manufacturers and the doctors who administer them. What lessons can be learnt from this case about how the Australian High Court is, or should be, approaching medical negligence cases and its role as guardian of the Australian common law?

  4. Fracture mechanics life analytical methods verification testing. Final report, 1 September 1991-12 September 1994

    SciTech Connect

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

    1994-09-01

    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.

  5. Growth inhibition in early life-stage tests predicts full life-cycle toxicity effects of lead in the freshwater pulmonate snail, Lymnaea stagnalis.

    PubMed

    Munley, Kathleen M; Brix, Kevin V; Panlilio, Jennifer; Deforest, David K; Grosell, Martin

    2013-03-15

    The freshwater pulmonate snail, Lymnaea stagnalis, is the most sensitive freshwater organism tested to date for several metals (Co, Cu, Pb, Ni) based on 28 d early life-stage (ELS) tests in which growth was the most sensitive endpoint. The United States Environmental Protection Agency (USEPA) has expressed concern that growth in 28 d ELS tests with mollusks may overpredict toxicity because of the potential for recovery in a full life-cycle (LC) test. Consequently, the USEPA only accepts the survival endpoint for these tests in establishing water quality criteria (WQC). To address this concern, the current study aimed to test the sensitivity of L. stagnalis to Pb in a 56 d full LC test evaluating survival, growth, reproductive and embryonic growth endpoints and compare the estimated effect levels to those established using the 28 d ELS test design. The most sensitive endpoints in this study were 28 d growth and 56 d egg mass production, both with a NOEC of <1.0 μg L(-1) and a LOEC of 1.0 μg L(-1), showing that the ELS growth endpoint is predictive of the 56 d reproduction endpoint. Snails exposed to 1.0 and 2.7 μg L(-1) Pb showed full and partial recovery from growth inhibition between 28 and 56 d. While this recovery supports the USEPA's concern about the 28 d growth endpoint; considering the reproductive lifespan of L. stagnalis and the recovery dose-response, we conclude that the 28 d growth endpoint will be within a factor of 3 of full LC endpoints. This is consistent with the level of precision previously determined for fish ELS tests, which the USEPA accepts for WQC derivation, and suggests that tests using 28 d ELS growth endpoint for L. stagnalis may be acceptable for inclusion in WQC derivation.

  6. 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.

  7. Determining pump wear and remaining life from electric submersible pump test curves. [Wear and service life estimation of oil well pumps

    SciTech Connect

    Divine, D.L.; Lannom, R.W.; Johnson, R.A. )

    1993-08-01

    The remaining useful life of an electric submersible pump (ESP) is an important economic consideration in deciding whether the used pump should be returned to service without repair. This paper presents quantitative and qualitative techniques to determine the type and amount of wear that a pump has experienced from analysis of pump test data. This paper discusses methods of categorizing used pumps, depending on the wear and associated performance deterioration. This work also describes failure modes, pump reliability, and the concept of pump (product) infant mortality. The authors show that a used pump can be more reliable and have a longer run life than a new or rebuilt pump. They use test data, tear-down analysis, and a case history to develop these concepts.

  8. Design, fabrication, and test of a hydrothermal reactor for origin-of-life experiments.

    PubMed

    Mielke, Randall E; Russell, Michael J; Wilson, Philip R; McGlynn, Shawn E; Coleman, Max; Kidd, Richard; Kanik, Isik

    2010-10-01

    We describe a continuous high-pressure flow reactor designed to simulate the unforced convective interaction of hydrothermal solutions and ocean waters with submarine crust on early Earth-conditions appropriate to those that may have led to the onset of life. The experimental operating conditions are appropriate for investigating kinetic hydrothermal processes in the early history of any sizable wet, rocky planet. Beyond the description of the fabrication, we report an initial experiment that tested the design and investigated the feasibility of sulfide and silica dissolution in alkaline solution from iron sulfide and basaltic rock, and their possible subsequent transport as HS(-) and H(2)SiO(2-)(4) in hot alkaline solutions. Delivery of hydrogen sulfide and dihydrogen silicate ions would have led to the precipitation of ferrous hydroxide, hydroxysilicates, and iron sulfides as integral mineral components of an off-ridge compartmentalized hydrothermal mound in the Hadean. Such a mound could, we contend, have acted as a natural chemical and electrochemical reactor and, ultimately, as the source of all biochemistry on our planet. In the event, we show that an average of ∼1 mM/kg of both sulfide and silica were released throughout, though over 10 mM/kg of HS(-) was recorded for ∼100 minutes in the early stages of the experiment. This alkaline effluent from the reactor was injected into a reservoir of a simulacrum of ferrous iron-bearing "Hadean Ocean" water in an experiment that demonstrated the capacity of such fluids to generate hydrothermal chimneys and a variety of contiguous inorganic microgeode precipitates bearing disseminations of discrete metal sulfides. Comparable natural composite structures may have acted as hatcheries for emergent life in the Hadean. PMID:21087160

  9. Design, fabrication, and test of a hydrothermal reactor for origin-of-life experiments.

    PubMed

    Mielke, Randall E; Russell, Michael J; Wilson, Philip R; McGlynn, Shawn E; Coleman, Max; Kidd, Richard; Kanik, Isik

    2010-10-01

    We describe a continuous high-pressure flow reactor designed to simulate the unforced convective interaction of hydrothermal solutions and ocean waters with submarine crust on early Earth-conditions appropriate to those that may have led to the onset of life. The experimental operating conditions are appropriate for investigating kinetic hydrothermal processes in the early history of any sizable wet, rocky planet. Beyond the description of the fabrication, we report an initial experiment that tested the design and investigated the feasibility of sulfide and silica dissolution in alkaline solution from iron sulfide and basaltic rock, and their possible subsequent transport as HS(-) and H(2)SiO(2-)(4) in hot alkaline solutions. Delivery of hydrogen sulfide and dihydrogen silicate ions would have led to the precipitation of ferrous hydroxide, hydroxysilicates, and iron sulfides as integral mineral components of an off-ridge compartmentalized hydrothermal mound in the Hadean. Such a mound could, we contend, have acted as a natural chemical and electrochemical reactor and, ultimately, as the source of all biochemistry on our planet. In the event, we show that an average of ∼1 mM/kg of both sulfide and silica were released throughout, though over 10 mM/kg of HS(-) was recorded for ∼100 minutes in the early stages of the experiment. This alkaline effluent from the reactor was injected into a reservoir of a simulacrum of ferrous iron-bearing "Hadean Ocean" water in an experiment that demonstrated the capacity of such fluids to generate hydrothermal chimneys and a variety of contiguous inorganic microgeode precipitates bearing disseminations of discrete metal sulfides. Comparable natural composite structures may have acted as hatcheries for emergent life in the Hadean.

  10. AVS regulation of cadmium bioavailability in a life-cycle sediment toxicity test using Leptocheirus plumulosus

    SciTech Connect

    DeWitt, T.H.; Swartz, R.C.; Hansen, D.J.; McGovern, D.; Berry, W.J.

    1995-12-31

    Numerous studies have shown the utility of interstitial water concentrations of metals and simultaneously extracted metals:acid volatile sulfide ratios (SEM:AVS) in explaining the acute toxicity of sediment-associated metals to benthic organisms, but no full life-cycle chronic tests have been conducted for this purpose. In this study, cohorts of newborn amphipods, Leptocheirus plumulosus, were exposed to cadmium-spiked estuarine sediment for 28 days to determine effects on mortality, growth, and reproduction relative to interstitial water and SEM:AVS normalizations. Seven treatments of Cd were tested: control, 0.35, 0.87, 1.32, 1.53, 2.22, and 5.10 molar SEM:AVS ratios. Overlying water, interstitial water and sediment concentrations of SEM Cd and AVS were monitored periodically and by depth during the exposure. When sediments SEM:AVS ratios were < 1.53, interstitial water concentrations of Cd were less than the 10-day water-only Cd LC50, and mortality, growth and reproduction were not affected. When SEM:AVS ratios were > 2.22, interstitial water Cd concentrations were greater than 100 times the 10-day water-only Cd LC50, and all amphipods died. These results are consistent with predictions of metal bioavailability from acute tests with metals-spiked sediments, i.e. that sediments with SEM:AVS ratios less than 1.0 and less than 0.5 interstitial water toxic units are not toxic, while sediments with SEM:AVS ratios greater than 1.0 and interstitial water toxic units (IWTUS) greater than 0.5 may be toxic.

  11. Calculation of the Phenix end-of-life test 'Control Rod Withdrawal' with the ERANOS code

    SciTech Connect

    Tiberi, V.

    2012-07-01

    The Inst. of Radiological Protection and Nuclear Safety (IRSN) acts as technical support to French public authorities. As such, IRSN is in charge of safety assessment of operating and under construction reactors, as well as future projects. In this framework, one current objective of IRSN is to evaluate the ability and accuracy of numerical tools to foresee consequences of accidents. Neutronic studies step in the safety assessment from different points of view among which the core design and its protection system. They are necessary to evaluate the core behavior in case of accident in order to assess the integrity of the first barrier and the absence of a prompt criticality risk. To reach this objective one main physical quantity has to be evaluated accurately: the neutronic power distribution in core during whole reactor lifetime. Phenix end of life tests, carried out in 2009, aim at increasing the experience feedback on sodium cooled fast reactors. These experiments have been done in the framework of the development of the 4. generation of nuclear reactors. Ten tests have been carried out: 6 on neutronic and fuel aspects, 2 on thermal hydraulics and 2 for the emergency shutdown. Two of them have been chosen for an international exercise on thermal hydraulics and neutronics in the frame of an IAEA Coordinated Research Project. Concerning neutronics, the Control Rod Withdrawal test is relevant for safety because it allows evaluating the capability of calculation tools to compute the radial power distribution on fast reactors core configurations in which the flux field is very deformed. IRSN participated to this benchmark with the ERANOS code developed by CEA for fast reactors studies. This paper presents the results obtained in the framework of the benchmark activity. A relatively good agreement was found with available measures considering the approximations done in the modeling. The work underlines the importance of burn-up calculations in order to have a fine

  12. Long-term mechanical life testing of polymeric post insulators for distribution and a comparison to porcelain

    SciTech Connect

    Cherney, E.A. )

    1988-07-01

    The paper presents the results and analyses of long-term cantilever strength tests on polymeric line post insulators. The time-to-failure data for static cantilever loads are represented by the Weibull distribution. The life distribution, obtained from the maximum likelihood estimates of the accelerated failure times, fits an exponential model. An extrapolation of the life distribution to normal loads provides an estimate of the strength rating and mechanical equivalence to porcelain line post insulators.

  13. 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.

  14. Chironomus tentans life-cycle test: Design and evaluation for use in assessing toxicity of contaminated sediments

    SciTech Connect

    Benoit, D.A.; Sibley, P.K.; Ankley, G.T.; Juenemann, J.L.

    1997-06-01

    The development and standardization of toxicity test methods for assessing toxicity of contaminated freshwater sediments has focused predominantly on short-term exposures and lethality. In many situations, however, toxicity is more likely to become manifest over long periods of time so there is need for standardized testing procedures by which sublethal sediment toxicity can be adequately assessed. In this study, the authors present and evaluate a new life cycle test, using the midge Chironomus tentans, which enables the assessment of sublethal toxicity of contaminated sediments. The test is initiated with newly hatched larvae and uses four effects-based endpoints to assess toxicity: survival, growth, emergence, and reproduction. Survival is determined at 20 d and at the end of the test by back-calculating through emergence data. Growth can be determined at 20 d, which corresponds to the 10-d endpoint in the 10-d C. tentans growth test initiated with 10-d-old larvae. From day 23 to the end of the test, emergence and reproduction are monitored daily. The number of eggs per female is determined for each egg mass, which is then incubated for 6 d to determine hatching success. Each treatment in the life cycle test is terminated separately after 7 consecutive days without emergence. The authors evaluated the life cycle test by following one generation of C. tentans in sediments collected from the upper Mississippi River. Survival of larvae exceeded 90% at 20 d. Of these larvae, between 60 and 70% successfully emerged; survivorship among pupae and adults exceeded 85%. Mean egg production ranged from 906 to 1,107 eggs per female. The test required 65 d to complete, including pretest preparation. These data show that the C. tentans life cycle test can be used to assess sublethal toxicity accurately in contaminated sediments and provides a suitable compliment to the standard C. tentans 10-d test.

  15. 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.

  16. 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.

  17. 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.

  18. 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."

  19. Derived Trail Making Test indices: demographics and cognitive background variables across the adult life span.

    PubMed

    Christidi, Foteini; Kararizou, Evangelia; Triantafyllou, Nikolaos; Anagnostouli, Maria; Zalonis, Ioannis

    2015-01-01

    We examined the contribution of demographics and cognitive background variables (processing speed, visuospatial skill, working memory, and interference control) on derived Trail Making Test (TMT) scores in a large sample of Greek healthy participants. We included 775 participants and administered the TMT (TMT-A and TMT-B) and the Wechsler Intelligence Adult Scale (WAIS). Direct (TMT-A & TMT-B time-to-completion) and derived [difference TMT-(B - A) & ratio TMT-(B/A)] scores were calculated. Demographics (age, age(2), education, and gender) and WAIS Full Intelligence Quotient significantly predicted the direct TMT-A (R(2) = 0.426) and TMT-B (R(2) = 0.593) scores and to a lesser extent, the derived TMT-(B - A) (R(2) = 0.343) and TMT-(B/A) (R(2) = 0.088) scores. In a subsample of 537 healthy participants who also completed the Stroop Neuropsychological Screening Test (SNST), demographics (age and education), WAIS Digit Symbol, Block Design, Arithmetic, and SNST accounted for 44.8% and 59.7% of the variance on TMT-A and TMT-B, and 32.5% and 9.6% of the variance on TMT-(B - A) and TMT-(B/A), respectively. We found minimal influence of Block Design and Arithmetic on TMT-(B - A) and an absence of significant influence of any cognitive variable on TMT-(B/A) score. Concluding, derived TMT scores are suggested as indices to detect impairment in cognitive flexibility across the adult life span, since they minimize the effect of demographics and other cognitive background variables.

  20. Testing fungistatic properties of soil-like substrate for growing plants in bioregenerative life support systems

    NASA Astrophysics Data System (ADS)

    Enzhu, Hu; Nesterenko, Elena; Liu, Professor Hong; Manukovsky, N. S.; Kovalev, Vladimir; Gurevich, Yu.; Kozlov, Vladimir; Khizhnyak, Serge; Xing, Yidong; Hu, Enzhu; Enzhu, Hu

    There are two ways of getting vegetable food in BLSS: in hydroponic culture and on soil substrates. In any case there is a chance that the plants will be affected by plant pathogenic microorganisms. The subject of the research was a soil-like substrate (SLS) for growing plants in a Bioregenerative Life Support System (BLSS). We estimated the fungistatic properties of SLS using test cultures of Bipolaris and Alternaria plant pathogenic fungi. Experiments were made with the samples of SLS, natural soil and sand (as control). We tested 2 samples of SLS produced by way of bioconversion of wheat and rice straw. We measured the disease severity of wheat seedlings and the incidence of common root rot in natural (non-infectious) background and man-made (infectious) conditions. The severity of disease on the SLS was considerably smaller both in non-infectious and infectious background conditions (8 and 12%) than on the natural soil (18 and 32%) and sand. It was the soil-like substrate that had the minimal value among the variants being compared (20% in non-infectious and 40% in infectious background conditions). This index in respect of the soil was 55 and 78%, correspondingly, and in respect of the sand - 60%, regardless of the background. It was found that SLS significantly suppressed conidia germination of Bipolaris soroikiniana (p<0.001). In the presence of SLS germination of conidia decreased to 9.9 - 12.2% of the control value. No significant differences were found between SLS samples obtained from wheat and rice straw.

  1. Accelerated life test for high-power white LED based on spectroradiometric measurement

    NASA Astrophysics Data System (ADS)

    Shen, Haiping; Pan, Jiangen; Feng, Huajun

    2008-03-01

    We implement an accelerated life test for the high-power white LEDs based on spectroradiometric measurement. The luminous flux degradation performances are investigated at both the rated current of 350mA and a higher current of 500mA. The average lifetime of the LEDs is 7057 hours at 350mA and 3508 hours at 500mA. The variations of the color of the white LEDs are studied. The color of the low quality white LEDs changes greatly, while the high quality white LEDs keep their color stable. The degradation performances of the chip and phosphor are studied separately. The quantum efficiency of the phosphor becomes lower from 350mA to 500mA current supply. The LED chip degrades faster than the phosphor during the 500mA high current aging. The luminous flux increase and the peak wavelength shift from 350mA to 500mA current supply are found to be useful lifetime indicating parameters that correlate well to the reliability of the high-power white LEDs.

  2. Accelerated test methods for life prediction of hermetic motor insulation systems exposed to alternative refrigerant/lubricant mixtures. Phase 3: Reproducibility and discrimination testing. Final report

    SciTech Connect

    Ellis, P.F. II; Ferguson, A.F.; Fuentes, K.T.

    1996-05-06

    In 1992, the Air-Conditioning and Refrigeration Technology Institute, Inc. (ARTI) contracted Radian Corporation to ascertain whether an improved accelerated test method or procedure could be developed that would allow prediction of the life of motor insulation materials used in hermetic motors for air-conditioning and refrigeration equipment operated with alternative refrigerant/lubricant mixtures. This report presents the results of phase three concerning the reproducibility and discrimination testing.

  3. 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

  4. 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. PMID:25722143

  5. 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.

  6. Using Perceived Health to Test the Construct-Related Validity of Global Quality of Life

    ERIC Educational Resources Information Center

    Beckie, Theresa M.; Hayduk, Leslie A.

    2004-01-01

    Quality of life (QOL) is considered as a global, yet unidimensional, subjective assessment of one's satisfaction with life. We examine the construct validity of the available indicators of global QOL by constructing a causal model in which QOL is viewed as causally responding to several dimensions of perceived health. Global QOL is measured with…

  7. 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.

  8. 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 squares…

  9. 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 ...

  10. 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…

  11. 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).

  12. Me, us, and them: Testing sociometer theory in a socially diverse real-life context.

    PubMed

    Reitz, Anne K; Motti-Stefanidi, Frosso; Asendorpf, Jens B

    2016-06-01

    Although numerous studies have emphasized the role evaluations by others play for people's self-esteem, the perspective of others and the social diversity of real-life contexts have largely been ignored. In a large-scale longitudinal study, we examined the link between adolescents' self-esteem and their self- and peer-perceived popularity in socially diverse classrooms. First, we tested the competing directions of effects predicted by sociometer theory (i.e., peer-perceived popularity affects self-esteem, mediated by self-perceived popularity) and the self-broadcasting perspective (i.e., self-esteem affects peer-perceived popularity). Second, we examined differential effects of popularity in the own social group ("us") versus others ("them") by using immigrant status groups (i.e., immigrants versus host-nationals). We examined 1,057 13-year-old students in 3 annual waves. Cross-lagged analyses revealed that popularity among peers of the in-group but not among peers of the out-group prospectively predicted self-esteem, which was mediated by self-perceived popularity. Self-esteem in turn prospectively predicted self- but not peer-perceived popularity. In sum, the findings provide support for sociometer theory and a conscious sociometer mechanism but no support for the self-broadcasting perspective. The findings further demonstrate that the sociometer was more responsive to popularity in immigrant status in- than out-groups. In conclusion, the findings underscore the need to consider the perspective of others and their social group memberships to better understand the complexities of the link between self-esteem and popularity. (PsycINFO Database Record

  13. Testing soil-like substrate for growing plants in bioregenerative life support systems

    NASA Astrophysics Data System (ADS)

    Gros, J. B.; Lasseur, Ch.; Tikhomirov, A. A.; Manukovsky, N. S.; Kovalev, V. S.; Ushakova, S. A.; Zolotukhin, I. G.; Tirranen, L. S.; Karnachuk, R. A.; Dorofeev, V. Yu.

    We studied soil-like substrate (SLS) as a potential candidate for plant cultivation in bioregenerative life support systems (BLSS). The SLS was obtained by successive conversion of wheat straw by oyster mushrooms and worms. Mature SLS contained 9.5% humic acids and 4.9% fulvic acids. First, it was shown that wheat, bean and cucumber yields as well as radish yields when cultivated on mature SLS were comparable to yields obtained on a neutral substrate (expanded clay aggregate) under hydroponics. Second, the possibility of increasing wheat and radish yields on the SLS was assessed at three levels of light intensity: 690, 920 and 1150 μmol m -2 s -1 of photosynthetically active radiation (PAR). The highest wheat yield was obtained at 920 μmol m -2 s -1, while radish yield increased steadily with increasing light intensity. Third, long-term SLS fertility was tested in a BLSS model with mineral and organic matter recycling. Eight cycles of wheat and 13 cycles of radish cultivation were carried out on the SLS in the experimental system. Correlation coefficients between SLS nitrogen content and total wheat biomass and grain yield were 0.92 and 0.97, respectively, and correlation coefficients between nitrogen content and total radish biomass and edible root yield were 0.88 and 0.87, respectively. Changes in hormone content (auxins, gibberellins, cytokinins and abscisic acid) in the SLS during matter recycling did not reduce plant productivity. Quantitative and species compositions of the SLS and irrigation water microflora were also investigated. Microbial community analysis of the SLS showed bacteria from Bacillus, Pseudomonas, Proteus, Nocardia, Mycobacterium, Arthrobacter and Enterobacter genera, and fungi from Trichoderma, Penicillium, Fusarium, Aspergillus, Mucor, Botrytis, and Cladosporium genera.

  14. Correlation of cardiopulmonary exercise testing parameters with quality of life in stable COPD patients

    PubMed Central

    Mirdamadi, Mahsa; Safavi, Enayat; Abtahi, Hamidreza; Peiman, Soheil

    2016-01-01

    Background The precise head to head relationships between Cardio-pulmonary exercise testing (CPET) parameters and patients’ daily symptoms/activities and the disease social/emotional impact are less well defined. In this study, the correlation of COPD daily symptoms and quality of life [assessed by St. George’s Respiratory Questionnaire (SGRQ)] and COPD severity index (BODE-index) with CPET parameters were investigated. Methods Symptom-limited CPET was performed in 37 consecutive COPD (GOLD I-III) subjects during non-exacerbation phase. The SGRQ was also completed by each patient. Results SGRQ-score correlated negatively with FEV1 (r=−0.49, P<0.01), predicted maximal work-rate (%WR-max) (r=−0.44, P<0.01), V’O2/WR (r=−0.52, P<0.01) and breathing reserve (r=−0.50, P<0.01). However it did not correlate with Peak-V’O2% predicted (r=−0.27, P=0.10). In 20 (54.1%) subjects in which leg fatigue was the main cause for stopping the test, Peak-V’O2, %WR-max, HR-Reserve and Breathing reserve were higher (P=0.04, <0.01, 0.04 and <0.01 respectively) than the others. There was also a significant correlation between BODE-index and ∆VO2/∆WR (r=−0.64, P<0.001) and breathing-reserve (r=−0.38, P=0.018). Conclusions The observed relationships between CPET parameter and daily subjective complaints in COPD were not strong. Those who discontinued the CPET because of leg fatigue were in the earlier stages of COPD. Significant negative correlation between ∆VO2/∆WR and BODE-index suggests that along with COPD progression, regardless of negative past history, other comorbidities such as cardiac/musculoskeletal problems should be sought. PMID:27621870

  15. Correlation of cardiopulmonary exercise testing parameters with quality of life in stable COPD patients

    PubMed Central

    Mirdamadi, Mahsa; Safavi, Enayat; Abtahi, Hamidreza; Peiman, Soheil

    2016-01-01

    Background The precise head to head relationships between Cardio-pulmonary exercise testing (CPET) parameters and patients’ daily symptoms/activities and the disease social/emotional impact are less well defined. In this study, the correlation of COPD daily symptoms and quality of life [assessed by St. George’s Respiratory Questionnaire (SGRQ)] and COPD severity index (BODE-index) with CPET parameters were investigated. Methods Symptom-limited CPET was performed in 37 consecutive COPD (GOLD I-III) subjects during non-exacerbation phase. The SGRQ was also completed by each patient. Results SGRQ-score correlated negatively with FEV1 (r=−0.49, P<0.01), predicted maximal work-rate (%WR-max) (r=−0.44, P<0.01), V’O2/WR (r=−0.52, P<0.01) and breathing reserve (r=−0.50, P<0.01). However it did not correlate with Peak-V’O2% predicted (r=−0.27, P=0.10). In 20 (54.1%) subjects in which leg fatigue was the main cause for stopping the test, Peak-V’O2, %WR-max, HR-Reserve and Breathing reserve were higher (P=0.04, <0.01, 0.04 and <0.01 respectively) than the others. There was also a significant correlation between BODE-index and ∆VO2/∆WR (r=−0.64, P<0.001) and breathing-reserve (r=−0.38, P=0.018). Conclusions The observed relationships between CPET parameter and daily subjective complaints in COPD were not strong. Those who discontinued the CPET because of leg fatigue were in the earlier stages of COPD. Significant negative correlation between ∆VO2/∆WR and BODE-index suggests that along with COPD progression, regardless of negative past history, other comorbidities such as cardiac/musculoskeletal problems should be sought.

  16. 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.

  17. 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

  18. 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 PMID:26011661

  19. 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.

  20. Assessing variability in chemical acute toxicity of unionid mussels: Influence of intra- and interlaboratory testing, life stage, and species.

    PubMed

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

    2016-03-01

    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 sensitivity among commonly tested mussels (Lampsilis siliquoidea, Utterbackia imbecillis, and Villosa iris), commonly tested cladocerans (Daphnia magna and Ceriodaphnia dubia), and fish (Oncorhynchus mykiss, Pimephales promelas, and Lepomis macrochirus). The results of these analyses indicate that intralaboratory variability for median effect concentrations (EC50) averaged about 2-fold for both life stages, whereas interlaboratory 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 sensitivity of commonly tested L. siliquoidea, U. imbecillis, and V. iris to that of other mussels. However, this concurrence decreased as the taxonomic distance of the commonly tested cladocerans and fish to mussels increased. 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. PMID:26369904

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

    SciTech Connect

    Patton, Gregory W.; Dauble, Dennis D.; Chamness, Michele A.; Abernethy, Cary S.; McKinstry, Craig A.

    2001-07-10

    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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Scoring Best on All Life's Tests--By Using Your "Whole Brain."

    ERIC Educational Resources Information Center

    Rubenzer, Ronald L.

    This collection of documents contains advice on doing well on tests by preparing and using the whole brain. The first sheet contains general tips for helping students become fact-smart, how to improve test-smartness, and how to build test-smartness. The combination of these three approaches assures that students will do their best on tests. The…

  8. 40 CFR 797.1600 - Fish early life stage toxicity test.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... exclusively. The number of organisms used should be gradually increased to approximately 5,000 nauplii by test... group used in the other test chambers, except that none of the test substance is added. If a carrier... solution and the calibration of the test substance delivery system. If......

  9. Accelerated test methods for life prediction of hermetic motor insulation systems exposed to alternative refrigerant/lubricant mixtures. Final report

    SciTech Connect

    Ellis, P.F. II; Ferguson, A.F.

    1995-04-19

    In 1992, the Air-Conditioning and Refrigeration Technology Institute, Inc. (ARTI) contracted Radian Corporation to ascertain whether an improved accelerated test method or procedure could be developed that would allow prediction of the life of motor insulation materials used in hermetic motors for air-conditioning and refrigeration equipment operated with alternative refrigerant/lubricant mixtures. Phase 1 of the project, Conceptual Design of an accelerated test method and apparatus, was successfully completed in June 1993. The culmination of that effort was the concept of the Simulated Stator Unit (SSU) test. The objective of the Phase 2 limited proof-of-concept demonstration was to: answer specific engineering/design questions; design and construct an analog control sequencer and supporting apparatus; and conduct limited tests to determine the viability of the SSU test concept. This report reviews the SSU test concept, and describes the results through the conclusion of the proof-of-concept prototype tests in March 1995. The technical design issues inherent in transforming any conceptual design to working equipment have been resolved, and two test systems and controllers have been constructed. Pilot tests and three prototype tests have been completed, concluding the current phase of work. One prototype unit was tested without thermal stress loads. Twice daily insulation property measurements (IPMs) on this unit demonstrated that the insulation property measurements themselves did not degrade the SSU.

  10. Accelerated test methods for life prediction of hermetic motor insulation systems exposed to alternative refrigerant/lubricant mixtures

    NASA Astrophysics Data System (ADS)

    Ellis, P. F., II; Ferguson, A. F.

    1995-04-01

    In 1992, the Air-Conditioning and Refrigeration Technology Institute, Inc. (ARTI) contracted Radian Corporation to ascertain whether an improved accelerated test method or procedure could be developed that would allow prediction of the life of motor insulation materials used in hermetic motors for air-conditioning and refrigeration equipment operated with alternative refrigerant/lubricant mixtures. Phase 1 of the project, Conceptual Design of an accelerated test method and apparatus, was successfully completed in June 1993. The culmination of that effort was the concept of the Simulated Stator Unit (SSU) test. The objective of the Phase 2 limited proof-of-concept demonstration was to: answer specific engineering/design questions; design and construct an analog control sequencer and supporting apparatus; and conduct limited tests to determine the viability of the SSU test concept. This report reviews the SSU test concept, and describes the results through the conclusion of the proof-of-concept prototype tests in March 1995. The technical design issues inherent in transforming any conceptual design to working equipment have been resolved, and two test systems and controllers have been constructed. Pilot tests and three prototype tests have been completed, concluding the current phase of work. One prototype unit was tested without thermal stress loads. Twice daily insulation property measurements (IPM's) on this unit demonstrated that the insulation property measurements themselves did not degrade the SSU.

  11. 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.

  12. A new early life-stage toxicity test using the California grunion (Leuresthes tenuis) and results with chlorpyrifos.

    PubMed

    Goodman, L R; Hansen, D J; Cripe, G M; Middaugh, D P; Moore, J C

    1985-08-01

    California grunion were continuously exposed as embryos and fry to technical chlorpyrifos in two toxicity tests conducted in the same exposure apparatus. The first test, a 35-day early life-stage (ELS) test, began with approximately 2.5-day-old embryos that were exposed in flow-through aquaria in darkness until hatching was stimulated on Day 9 of exposure. The second toxicity test, a fry test, began with newly hatched fry and lasted 26 days. Test water temperature ranged from 23 to 26 degrees C and salinity from 24.5 to 34.0%. Results of the two tests were similar, indicating that exposure of embryos added little to the overall toxicity of chlorpyrifos to grunions. Percentage hatch of embryos was unaffected by the chlorpyrifos concentrations tested. Fry survival was apparently reduced in nominal concentrations greater than or equal to 1.0 micrograms/liter in both tests, but significantly so in concentrations greater than or equal to 1.0 micrograms/liter in the ELS test and greater than or equal to 2.0 micrograms/liter in the fry test. When compared with carrier controls, mean fish weights were significantly reduced in nominal chlorpyrifos concentrations greater than or equal to 0.5 micrograms/liter in the ELS test and greater than or equal to 1.0 micrograms/liter in the fry exposure. Mean bioconcentration factors were 770X for fish that survived the ELS test and 190X for those that survived the fry test. Results demonstrate the practicality of conducting ELS tests for the first time with a marine fish from the Pacific coastal waters of the United States. PMID:2411496

  13. 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.

  14. Accelerated aging of extruded dielectric power cables. Part 2; Life testing of 15 kV XLPE-insulated cables

    SciTech Connect

    Bernstein, B.S.; Thue, W.A. ); Walton, M.D.; Smith J.T. III )

    1992-04-01

    Attempts to successfully use accelerated aging tests to quantify the life of medium voltage power cables in service have been elusive. This paper describes preliminary results in which 15 kV XLPE cables were subjected to accelerated aging tests under a variety of controlled voltage stress and thermal load cycle conditions, with loss of life being calculated for each set of conditions in terms of the geometric mean time to failure (GMTF). In this paper the relative influence of voltage stress and load cycle temperature are discussed. This work is part of a broad effort that also involves studies with EPR-insulated cables, accelerated aging of cables from the same manufacturing run that are direct buried at the manufacturer's site, and also aging of these cables under normal operating conditions at four United States utilities.

  15. Ethical Issues and the Life Sciences. Test Edition. AAAS Study Guides on Contemporary Problems.

    ERIC Educational Resources Information Center

    Kieffer, George H.

    This is one of several study guides on contemporary problems produced by the American Association for the Advancement of Science with support of the National Science Foundation. This study guide on Ethical Issues and the Life Sciences includes the following sections: (1) Introduction; (2) The Search for an Ethic; (3) Biomedical Issues including…

  16. 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.

  17. A critical review of the life sciences project management at Ames Research Center for the Spacelab Mission development test 3

    NASA Technical Reports Server (NTRS)

    Helmreich, R. L.; Wilhelm, J. M.; Tanner, T. A.; Sieber, J. E.; Burgenbauch, S. F.

    1979-01-01

    A management study was initiated by ARC (Ames Research Center) to specify Spacelab Mission Development Test 3 activities and problems. This report documents the problems encountered and provides conclusions and recommendations to project management for current and future ARC life sciences projects. An executive summary of the conclusions and recommendations is provided. The report also addresses broader issues relevant to the conduct of future scientific missions under the constraints imposed by the space environment.

  18. 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.

  19. 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.

  20. Status of the extended life test of the Deep Space 1 flight spare ion engine after 30,352 hours of operation

    NASA Technical Reports Server (NTRS)

    Sengupta, Anita; Brophy, John R.; Goodfellow, Keith D.

    2003-01-01

    The extended life test (ELT) of the Deep Space 1 (DS1) spare flight ion thruster (FT2) was voluntarily terminated June 26th 2003. The test was started in Cotober of 1998, just prior to the launch of the DS1 spacecraft, with the primary purpose of determining the ultimate service life capability of the NASA 30-cm-ion thruster technology.

  1. Standardizing acute toxicity data for use in ecotoxicology models: influence of test type, life stage, and concentration reporting.

    PubMed

    Raimondo, Sandy; Vivian, Deborah N; Barron, Mace G

    2009-10-01

    Ecotoxicological models generally have large data requirements and are frequently based on existing information from diverse sources. Standardizing data for toxicological models may be necessary to reduce extraneous variation and to ensure models reflect intrinsic relationships. However, the extent to which data standardization is necessary remains unclear, particularly when data transformations are used in model development. An extensive acute toxicity database was compiled for aquatic species to comprehensively assess the variation associated with acute toxicity test type (e.g., flow-through, static), reporting concentrations as nominal or measured, and organism life stage. Three approaches were used to assess the influence of these factors on log-transformed acute toxicity: toxicity ratios, log-linear models of factor groups, and comparison of interspecies correlation estimation (ICE) models developed using either standardized test types or reported concentration type. In general, median ratios were generally less than 2.0, the slopes of log-linear models were approximately one for well-represented comparisons, and ICE models developed using data from standardized test types or reported concentrations did not differ substantially. These results indicate that standardizing test data by acute test type, reported concentration type, or life stage may not be critical for developing ecotoxicological models using large datasets of log-transformed values.

  2. Atmospheric Monitoring Strategy for Ground Testing of Closed Ecological Life Support Systems

    NASA Technical Reports Server (NTRS)

    Feighery, John; Cavenall, Ivan; Knight, Amanda

    2004-01-01

    This paper reviews the evolution and current state of atmospheric monitoring on the International Space Station to provide context from which we can imagine a more advanced and integrated system. The unique environmental hazards of human space flight are identified and categorized into groups, taking into consideration the time required for the hazard to become a threat to human health or performance. The key functions of a comprehensive monitoring strategy for a closed ecological life support system are derived from past experience and a survey of currently available technologies for monitoring air quality. Finally, a system architecture is developed incorporating the lessons learned from ISS and other analogous closed life support systems. The paper concludes by presenting recommendations on how to proceed with requirements definition and conceptual design of an air monitoring system for exploration missions.

  3. The Impact of Dizziness on the Quality of Life of 235 Individuals who Completed Vestibular Testing in Brazil

    PubMed Central

    Burle, Najlla Lopes de Oliveira; Abreu, Ana Célia Pereira de; Santos, Juliana Nunes; Mancini, Patricia Cotta

    2015-01-01

    Introduction In Vestibular Testing (VT), caloric tests allow evaluation of unilateral weakness (UW) and directional preponderance (DP), where different criteria of normality are adopted in Brazil and worldwide. The Brazilian version of the Dizziness Handicap Inventory (Brazilian DHI) evaluates the impact of dizziness on the quality of life of an individual. Objectives The objective of this research is to evaluate the impact of dizziness on the quality of life of patients undergoing VT, and to relate these findings to the results obtained according to national and international criteria. Methods Cross-sectional analytic study of 235 patients referred for VT in two hospitals. The authors performed the Brazilian DHI, history, static, and dynamic balance tests, positional nystagmus, and the Dix-Hallpike maneuver, as well as vectoelectronystagmography. Subjects were divided into three groups according to UW and DP values. Descriptive statistics and comparisons between groups were performed, considering a significance level of 5% in all analyses. Results Patients groups had 20.9% men, and 79.1% women. There was no significant difference between groups for the scores obtained in the Brazilian DHI. There was, however, a statistically significant difference in the redistribution of individuals according to the UW and DP values. Conclusion There was no relationship between VT results and the impact of dizziness in the quality of life. A review of normal values for UW and DP adopted in Brazil is suggested, as well as the application of the Brazilian DHI as an additional tool to evaluate the impact of dizziness on quality of life in all patients undergoing VT. PMID:26722347

  4. Life tests of Nichia AlGaN/InGaN/GaN blue-light-emitting diodes

    SciTech Connect

    Helms, C.J.; Berg, N.H.; Barton, D.L.; Osinski, M

    1996-03-01

    We report on results of life testing Nichia NLPB500 blue LEDs in a temperature controlled chamber, with computer automation of equipment operation and data collection. The tests began with 18 newer (Nichia batch 4B0001) and two older (Nichia batch S403024, acquired a year earlier) LEDs, operated at 20 mA continuous wave (CW) and 23{degree}C. Light from each LED was coupled to an optical fiber and fed directly to individual photodetectors. General trend for the 18 newer LEDs was for the output intensity to increase at a faster rate within the first 50 h and then at a slower rate of the remainder of the first test. The output intensity of the two older LEDs increase within the first 50 h then decreased during the remainder of the first 1000 h. All 20 of the LEDs in the first 1000-h test were subjected to a second 1650-h test at 23{degree}C and at currents 20-70 mA CW. Only one LED, an older device, suffered a soft failure during this second test. The remaining LEDs underwent a third test at 30{degree}C and a fourth test at 35{degree}C, all at various currents. We will perform failure analysis.

  5. 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.

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

    PubMed Central

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

    2010-01-01

    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. PMID:20216915

  7. Spacesuit Portable Life Support System Breadboard (PLSS 1.0) Development and Test Results

    NASA Technical Reports Server (NTRS)

    Vogel, Matt R.; Watts, Carly

    2011-01-01

    A multi-year effort has been carried out at NASA-JSC to develop an advanced Extravehicular Activity (EVA) 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 (ISS) Extravehicular Mobility Unit (EMU) PLSS, the advanced PLSS comprises of three subsystems required to sustain the crew during EVA including the Thermal, Ventilation, and Oxygen Subsystems. This multi-year effort has culminated in the construction and operation of PLSS 1.0, a test rig 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 loop fan, Rapid Cycle Amine (RCA) swingbed, and Spacesuit Water Membrane Evaporator (SWME). Testing accumulated 239 hours over 45 days, while executing 172 test points. Specific PLSS 1.0 test objectives assessed during this testing include: confirming key individual components perform in a system level test as they have performed during component level testing; identifying unexpected system-level interactions; operating PLSS 1.0 in nominal steady-state EVA modes to baseline subsystem performance with respect to metabolic rate, ventilation loop pressure and flow rate, and environmental conditions; simulating nominal transient EVA operational scenarios; simulating contingency EVA operational scenarios; and further evaluating individual technology development components. Successful testing of the PLSS 1.0 provided a large database of test results that characterize system level and component performance. With the exception of several minor anomalies, the PLSS 1.0 test rig performed as expected; furthermore, many system

  8. 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.

  9. Uniform Peanut Performance Tests (UPPT) for 2005: Chemical, sensory and shelf-life properties by variety.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Uniform Peanut Performance Tests (UPPT) were established in 1973 through an informal arrangement among cooperating scientists involving seven major peanut-producing states. The purpose of these tests is to evaluate the commercial potential of advanced peanut breeding lines not formally released ...

  10. Method refinements for the midge life-cycle, Chironomus dilutus test

    EPA Science Inventory

    Larval stages of non-biting midges can be found in almost any freshwater ecosystem, and one of the commonly tested midges is Chironomus dilutus (Chironomidae, Diptera) which is used for toxicity testing and ecological risk assessment of freshwater contaminants. USEPA, ASTM, Envir...

  11. Spacesuit Portable Life Support System Breadboard (PLSS 1.0) Development and Test Results

    NASA Technical Reports Server (NTRS)

    Watts, Carly A.; Vogel, Matt

    2012-01-01

    A multi-year effort has been carried out at the Johnson Space Center to develop an advanced EVA PLSS design intended to further the current state of the art by increasing operational flexibility, reducing consumables, and increasing robustness. This multi-year effort has culminated in the construction and operation of PLSS 1.0, a test rig 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 loop fan, Rapid Cycle Amine (RCA) swingbed, and Spacesuit Water Membrane Evaporator (SWME). PLSS 1.0 was tested from June 17th through September 30th, 2011. Testing accumulated 233 hours over 45 days, while executing 119 test points. An additional 164 hours of operational time were accrued during the test series, bringing the total operational time for PLSS 1.0 testing to 397 hours. Specific PLSS 1.0 test objectives assessed during this testing include: (1) Confirming prototype components perform in a system level test as they have performed during component level testing, (2) Identifying unexpected system-level interactions (3) Operating PLSS 1.0 in nominal steady-state EVA modes to baseline subsystem performance with respect to metabolic rate, ventilation loop pressure and flow rate, and environmental conditions (4) Simulating nominal transient EVA operational scenarios (5) Simulating contingency EVA operational scenarios (6) Further evaluating prototype technology development components Successful testing of the PLSS 1.0 provided a large database of test results that characterize system level and component performance. With the exception of several minor anomalies, the PLSS 1.0 test rig performed as expected. Documented anomalies and observations include: (1) Ventilation loop fan controller issues at high fan speeds (near 70,000 rpm, whereas the fan speed during nominal operations would be closer

  12. Super NiCd Open-Circuit Storage and Low Earth Orbit (LEO) Life Test Evaluation

    NASA Technical Reports Server (NTRS)

    Baer, Jean Marie; Hwang, Warren C.; Ang, Valerie J.; Hayden, Jeff; Rao, Gopalakrishna; Day, John H. (Technical Monitor)

    2002-01-01

    This presentation discusses Air Force tests performed on super NiCd cells to measure their performance under conditions simulating Low Earth Orbit (LEO) conditions. Super NiCd cells offer potential advantages over existing NiCd cell designs including advanced cell design with improved separator material and electrode making processes, but handling and storage requires active charging. These tests conclude that the super NiCd cells support generic Air Force qualifications for conventional LEO missions (up to five years duration) and that handling and storage may not actually require active charging as previously assumed. Topics covered include: Test Plan, Initial Characterization Tests, Open-Circuit Storage Tests, and post storage capacities.

  13. Long Duration Life Test of Propylene Glycol Water Based Thermal Fluid Within Thermal Control Loop

    NASA Technical Reports Server (NTRS)

    Le, Hung; Hill, Charles; Stephan, Ryan A.

    2010-01-01

    Evaluations of thermal properties and resistance to microbial growth concluded that 50% Propylene Glycol (PG)-based fluid and 50% de-ionized water mixture was desirable for use as a fluid within a vehicle s thermal control loop. However, previous testing with a commercial mixture of PG and water containing phosphate corrosion inhibitors resulted in corrosion of aluminum within the test system and instability of the test fluid. This paper describes a follow-on long duration testing and analysis of 50% Propylene Glycol (PG)-based fluid and 50% de-ionized water mixture with inorganic corrosion inhibitors used in place of phosphates. The test evaluates the long-term fluid stability and resistance to microbial and chemical changes

  14. Reactive carbon from life support wastes for incinerator flue gas cleanup-System Testing

    SciTech Connect

    Fisher, John W.; Pisharody, Suresh; Moran, Mark J.; Wignarajah, Kanapathipillai; Xu, X.H.; Shi, Yao; Chang, Shih-Ger

    2002-05-14

    This paper presents the results from a joint research initiative between NASA Ames Research Center and Lawrence Berkeley National lab. The objective of the research is to produce activated carbon from life support wastes and to use the activated carbon to adsorb and chemically reduce the NO{sub x} and SO{sub 2} contained in incinerator flue gas. Inedible biomass waste from food production is the primary waste considered for conversion to activated carbon. Results to date show adsorption of both NO{sub x} and SO{sub 2} in activated carbon made from biomass. Conversion of adsorbed NO{sub x} to nitrogen has also been observed.

  15. Space Suit Portable Life Support System Rapid Cycle Amine Repackaging and Sub-Scale Test Results

    NASA Technical Reports Server (NTRS)

    Paul, Heather L.; Rivera, Fatonia L.

    2010-01-01

    NASA is developing technologies to meet requirements for an extravehicular activity (EVA) Portable Life Support System (PLSS) for exploration. The PLSS Ventilation Subsystem transports clean, conditioned oxygen to the pressure garment for space suit pressurization and human consumption, and recycles the ventilation gas, removing carbon dioxide, humidity, and trace contaminants. This paper provides an overview of the development efforts conducted at the NASA Johnson Space Center to redesign the Rapid Cycle Amine (RCA) canister and valve assembly into a radial flow, cylindrical package for carbon dioxide and humidity control of the PLSS ventilation loop. Future work is also discussed.

  16. Prediction of fatigue life of plain concrete beams from fracture tests

    SciTech Connect

    Ramsamooj, D.V. )

    1994-05-01

    A mathematical model, based on the principles of fracture mechanics, is proposed for the prediction of the flexural fatigue life of plain concrete beams. The model predictions are compared with about 400 experimental data from four separate collections, published earlier, covering materials with wide ranges of compressive strengths, 20 Mpa to 44.8 MPa, stress range ratios (minimum/maximum bending stress) of 0 to 0.75, and flexing frequencies of 1 to 20 Hz. There is good agreement between the model and the regression lines fitted to the experiment data.

  17. A toxicity test in artificial soil based on the life-history strategy of the nematode Plectus acuminatus

    SciTech Connect

    Kammenga, J.E.; Van Koert, P.H.G.; Riksen, J.A.G.; Korthals, G.W.; Bakker, J.

    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 of 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.

  18. Life after BRCA1/2 testing: family communication and support issues.

    PubMed

    DeMarco, Tiffani A; McKinnon, Wendy C

    The process of genetic testing is often deemed a family affair. Several studies have indicated that individuals undergo BRCA1/2 testing not only to learn about their own cancer risks and options for screening and prevention, but also to gather information for potentially at-risk relatives. However, many individuals are not prepared for the medical and emotional implications that accompany the genetic testing process. This can be complicated by a moral or ethical obligation to disclose result status to other family members. Several characteristics including gender, BRCA1/2 carrier status, and cultural and ethnic background may influence the communication process between the proband and his/her potentially at-risk kin. In addition, the age of family members and their degree of relatedness may affect whether or not they are told the results of their relative's genetic testing. While genetic providers have an obligation to inform individuals of the implications of BRCA1/2 test results for at-risk relatives, they must also strive to respect and maintain autonomy and confidentiality. This paper will examine the characteristics that influence the disclosure of BRCA1/2 test results to relatives. In addition, methods of post-test support and follow-up to facilitate the disclosure process for patients and their family members as well as foster positive communication, will be discussed. PMID:17917144

  19. Life testing of LSM-YSZ composite electrodes under reversing-current operation.

    PubMed

    Hughes, Gareth A; Yakal-Kremski, Kyle; Barnett, Scott A

    2013-10-28

    Durability testing of solid oxide cell electrodes in reversing-current and constant-current operation modes is presented. (La0.8Sr0.2)0.98MnO3-δ-Zr0.84Y0.16O2-γ (LSM-YSZ) symmetric cells were tested at 800 °C in air with current densities of 0.5 and 1.5 A cm(-2), with current cycle periods of 1 and 12 h. A continuous increase in both ohmic and polarization resistance was observed, via Electrochemical Impedance Spectroscopy (EIS), for cells tested with a reversing current of 1.5 A cm(-2), whereas cells tested at 0.5 A cm(-2) showed no measurable resistance increase. The resistance degradation was explained by delamination in the electrode, observed by post-test Scanning Electron Microscopy (SEM), near the interface with the electrolyte for the 1.5 A cm(-2) cells, but not for those tested at 0.5 A cm(-2). Current cycle period also impacted the degradation observed at 1.5 A cm(-2): both the rate of resistance increase and the extent of post-test delamination decreased on going from constant current mode to a 12 h period to a 1 h period. The results indicate that lower current densities and reversing-current operation are desirable to maximize the lifetime of solid oxide cells.

  20. Comparative life test of 0.8-micron-laser diodes for SILEX under NRZ and QPPM modulation

    NASA Astrophysics Data System (ADS)

    Menke, Bodo; Loeffler, Roland

    1991-06-01

    The procedures and preliminary results of accelerated life tests performed within the framework of an evaluation program under the ESA contract are described. In order to calculate the activation energy and median lifetime and to investigate the drift behavior of optical parameters, a conventional three-temperature aging test at 30, 50, and 70 C is performed on 80 laser diodes in total, split into two subgroups operating under quaternary pulse position modulation (QPPM) and nonreturn-to-zero (NRZ) modulation at 16 Mbit/s with a PN-code length of (2 exp 7)-1. Measurements before and upon completion of the aging tests consist of P0/I curves, V/I characteristics, photo diode tracking ratios, spectra, mode hopping behaviors, far-field patterns, wave-front errors and astigmatisms, and linear polarization ratios.

  1. Long Term Borehole Monitoring System For NanTroSEIZE 3.5 km Riser Hole: Environmental Life Test and Land Test

    NASA Astrophysics Data System (ADS)

    Kyo, M.; Araki, E.; Ito, H.

    2009-12-01

    Most of the large earthquakes (magnitude greater than 8.0) observed in Japan fall into the subduction plate-boundary category. Based on the results of previous Nankai Trough research efforts, further research opportunities have been proposed under the umbrella of the IODP scientific drilling proposal 603 (NanTroSEIZE: Nankai Trough Seismogenic Zone Experiment) ranked as the top level proposal in IODP. IODP proposal 603 not only proposes drilling, coring and geological analysis, and geophysical logging, but also mandates that a long-term borehole monitoring system be installed into two deep riser holes at about 3,500 m and about 6,000 m below sea floor (mbsf), where we expect to encounter the mega-splay and the locked region of mega thrust fault, respectively. The target of 3,500 m riser hole is expected to drill through five potential splay faults above 3,500 mbsf. We plan to install sensors to monitor strain, tilt and optionally pore pressure for crustal deformation at and between splay faults, to monitor seismometer array for micro and slow earthquakes detection and for seismic microstructures, and to monitor pore pressure and temperature for hydrologic state change at the fault during interseismic period. The major technical features to develop the borehole observatory for 3,500 m riser hole are mainly as follows; 1) high temperature (125°C), 2) long life (5 years), 3) deployment (15,000 psi wellhead system, deep well, retrieval, perforation, packer, mechanical shock), 4) coupling to formation (cement, clamp), 5) multi level monitoring (against 5 spray faults), 6) multi purpose monitoring (seismic, geodetic, hydrogeologic), 7) low power consumption, 8) real time monitoring (connecting to sea bed cable), 9) accurate synchronization, 10) wide frequency range / high dynamic range ADC, 11) down sizing (installing into 9-5/8”casing with tubing), 12) system redundancy (fault tolerant). We started the development of an experimental prototype (EXP) for field test

  2. Search for extraterrestrial life using chiral molecules: mandelate racemase as a test case.

    PubMed

    Thaler, Tracey L; Gibbs, Phillip R; Trebino, Rick P; Bommarius, Andreas S

    2006-12-01

    We have investigated an enzymatic racemization reaction as a marker for extraterrestrial life, which resulted in a change in optical rotation of a mandelic acid over time, as measured by polarimetry. Mandelate racemase was active in aqueous buffer in a temperature range between 0 degrees C and 70 degrees C and also in concentrated ammonium salt solutions and water-in-oil microemulsions in a temperature range between -30 degrees C and 60-70 degrees C; however, the enzyme was not active in several organic cryosolvents. Thus, we have demonstrated that concentrated ammonium salt solutions and water-in-oil microemulsions, both of which are able to form on extraterrestrial planets and moons in the presence of liquid water, are suitable media for enzyme reactions at subzero temperatures. Kinetic data for the mandelate racemase reaction obtained by polarimetry, while reproducible and internally consistent, differed significantly from several sets of data obtained previously by other methods such as chromatography and hydrogen-deuterium exchange. However, we conclude that reactions yielding a polarimetric signal, such as the racemizations employed in this work, are suitable mechanisms by which to utilize a change in chirality over time as a tool to detect signs of life.

  3. Search for Extraterrestrial Life Using Chiral Molecules: Mandelate Racemase as a Test Case

    NASA Astrophysics Data System (ADS)

    Thaler, Tracey L.; Gibbs, Phillip R.; Trebino, Rick P.; Bommarius, Andreas S.

    2006-12-01

    We have investigated an enzymatic racemization reaction as a marker for extraterrestrial life, which resulted in a change in optical rotation of a mandelic acid over time, as measured by polarimetry. Mandelate racemase was active in aqueous buffer in a temperature range between 0°C and 70°C and also in concentrated ammonium salt solutions and water-in-oil microemulsions in a temperature range between -30°C and 60-70°C however, the enzyme was not active in several organic cryosolvents. Thus, we have demonstrated that concentrated ammonium salt solutions and water-in-oil microemulsions, both of which are able to form on extraterrestrial planets and moons in the presence of liquid water, are suitable media for enzyme reactions at subzero temperatures. Kinetic data for the mandelate racemase reaction obtained by polarimetry, while reproducible and internally consistent, differed significantly from several sets of data obtained previously by other methods such as chromatography and hydrogen-deuterium exchange. However, we conclude that reactions yielding a polarimetric signal, such as the racemizations employed in this work, are suitable mechanisms by which to utilize a change in chirality over time as a tool to detect signs of life.

  4. A priori models in the testing of diving life support equipment.

    PubMed

    Clarke, J R

    1996-01-01

    A priori models have been effectively used at the Navy Experimental Diving Unit (NEDU) to aid in the design of tests for diving equipment. These models are computer simulations conducted prior to the initial testing effort, using mechanistic models derived from first principles or based on prior testing. One example of such a model involves the freeze-up susceptibility of SCUBA regulators used in very cold water at depths to 58 msw (190 fsw). The influence of various dive profiles on the risk of regulator freeze-up was estimated for a variety of model parameters. In a second example, a simple model of CO2 canister duration was used to reveal the relative benefits of various competing diver work/rest profiles. The a priori modeling efforts helped NEDU define relatively efficient and unambiguous designs for testing diving equipment.

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

    NASA Astrophysics Data System (ADS)

    Pan, Lei; Liu, Kun; Breton, Francis; -Grant Chen, X.

    2016-10-01

    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.

  6. 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.

  7. Life and stability testing of packaged low-cost energy storage materials

    SciTech Connect

    Frysinger, G.R.

    1980-07-01

    A low-cost laminated plastic film which is used to contain a Glauber's salt-based phase change thermal energy storage material in sausage-like containers called Chubs is discussed. The results of tests performed on the Chub packages themselves and on the thermal energy storage capacity of the packaged phase change material are described. From the test results, a set of specifications have been drawn up for a film material which will satisfactorily contain the phase change material under anticipated operating conditions. Calorimetric testing of the phase change material with thermal cycling indicates that a design capacity of 45 to 50 Btu/lb for a ..delta..T of 30/sup 0/F can be used for the packaged material.

  8. The synergistic roles of test and simulation in the life cycle of the Army Tactical Missile System

    NASA Astrophysics Data System (ADS)

    Curry, David M.; Ricks, Gayle; Thomas, Tony L.

    2010-04-01

    The Army Tactical Missile System (ATACMS) has been fielded with the US Army for almost 20 years as a deep strike precision weapon, capable of engaging time critical targets at high precision under all weather conditions. This paper will describe the use of the HWIL simulation in the design of the missile, validation of the simulation, the role of the simulation in the production and test process, how the simulation is used to support system shelf life and obsolescence issues and how the simulation is used to answer critical user questions on the performance of the system.

  9. Effects on fatigue life of gate valves due to higher torque switch settings during operability testing

    SciTech Connect

    Richins, W.D.; Snow, S.D.; Miller, G.K.; Russell, M.J.; Ware, A.G.

    1995-12-01

    Some motor operated valves now have higher torque switch settings due to regulatory requirements to ensure valve operability with appropriate margins at design basis conditions. Verifying operability with these settings imposes higher stem loads during periodic inservice testing. These higher test loads increase stresses in the various valve internal parts which may in turn increase the fatigue usage factors. This increased fatigue is judged to be a concern primarily in the valve disks, seats, yokes, stems, and stem nuts. Although the motor operators may also have significantly increased loading, they are being evaluated by the manufacturers and are beyond the scope of this study. Two gate valves representative of both relatively weak and strong valves commonly used in commercial nuclear applications were selected for fatigue analyses. Detailed dimensional and test data were available for both valves from previous studies at the Idaho National Engineering Laboratory. Finite element models were developed to estimate maximum stresses in the internal parts of the valves and to identity the critical areas within the valves where fatigue may be a concern. Loads were estimated using industry standard equations for calculating torque switch settings prior and subsequent to the testing requirements of USNRC Generic Letter 89--10. Test data were used to determine both; (1) the overshoot load between torque switch trip and final seating of the disk during valve closing and (2) the stem thrust required to open the valves. The ranges of peak stresses thus determined were then used to estimate the increase in the fatigue usage factors due to the higher stem thrust loads. The usages that would be accumulated by 100 base cycles plus one or eight test cycles per year over 40 and 60 years of operation were calculated.

  10. Comparison of toxicity values across zebrafish early life stages and mammalian studies: Implications for chemical testing.

    PubMed

    Ducharme, Nicole A; Reif, David M; Gustafsson, Jan-Ake; Bondesson, Maria

    2015-08-01

    With the high cost and slow pace of toxicity testing in mammals, the vertebrate zebrafish has become a tractable model organism for high throughput toxicity testing. We present here a meta-analysis of 600 chemicals tested for toxicity in zebrafish embryos and larvae. Nineteen aggregated and 57 individual toxicity endpoints were recorded from published studies yielding 2695 unique data points. These data points were compared to lethality and reproductive toxicology endpoints analyzed in rodents and rabbits and to exposure values for humans. We show that although many zebrafish endpoints did not correlate to rodent or rabbit acute toxicity data, zebrafish could be used to accurately predict relative acute toxicity through the rat inhalation, rabbit dermal, and rat oral exposure routes. Ranking of the chemicals based on toxicity and teratogenicity in zebrafish, as well as human exposure levels, revealed that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), benzo(a)pyrene, and chlorpyrifos ranked in the top nine of all chemicals for these three categories, and as such should be considered high priority chemicals for testing in higher vertebrates. PMID:25261610

  11. Comparison of toxicity values across zebrafish early life stages and mammalian studies: Implications for chemical testing.

    PubMed

    Ducharme, Nicole A; Reif, David M; Gustafsson, Jan-Ake; Bondesson, Maria

    2015-08-01

    With the high cost and slow pace of toxicity testing in mammals, the vertebrate zebrafish has become a tractable model organism for high throughput toxicity testing. We present here a meta-analysis of 600 chemicals tested for toxicity in zebrafish embryos and larvae. Nineteen aggregated and 57 individual toxicity endpoints were recorded from published studies yielding 2695 unique data points. These data points were compared to lethality and reproductive toxicology endpoints analyzed in rodents and rabbits and to exposure values for humans. We show that although many zebrafish endpoints did not correlate to rodent or rabbit acute toxicity data, zebrafish could be used to accurately predict relative acute toxicity through the rat inhalation, rabbit dermal, and rat oral exposure routes. Ranking of the chemicals based on toxicity and teratogenicity in zebrafish, as well as human exposure levels, revealed that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), benzo(a)pyrene, and chlorpyrifos ranked in the top nine of all chemicals for these three categories, and as such should be considered high priority chemicals for testing in higher vertebrates.

  12. Life Before Tests: A District's Coordinated Health Approach for Addressing Children's Full Range of Needs

    ERIC Educational Resources Information Center

    Cooper, Patrick

    2005-01-01

    Chronic illnesses, depression, abuse of drugs, alcohol and tobacco. Sugary snacks and drinks, vending machines, obesity and bullying. Guns, gang violence, school shootings and test scores. Teen-age birth rates, one-parent households, lack of health or dental care, and, dropouts. All of these issues are interconnected and intertwined with education…

  13. Childhood physical abuse and midlife physical health: Testing a multi-pathway life course model

    PubMed Central

    Springer, K. W.

    2009-01-01

    Although prior research has established that childhood abuse adversely affects midlife physical health outcomes, it is unclear how abuse continues to harm health decades after the abuse has ended. In this project, I assess four life course pathways (behavioral, emotional, cognitive, and social relations) that plausibly link childhood physical abuse to three midlife physical health outcomes (bronchitis diagnosis, ulcer diagnosis, and general physical health). These three outcomes are etiologically distinct, leading to unique testable hypotheses. Multivariate models controlling for childhood background and early adversity were estimated using data from over 3,000 respondents in the Wisconsin Longitudinal Study, USA. The results indicate that midlife social relations and cognition do not function as pathways for any outcome. However, smoking is a crucial pathway connecting childhood abuse with bronchitis; mental health is important for ulcers; and BMI, smoking, and mental health are paramount for general physical health. These findings suggest that abuse survivors’ coping mechanisms can lead to an array of midlife health problems. Furthermore, the results validate the use of etiologically distinct outcomes for understanding plausible causal pathways when using cross-sectional data. PMID:19446943

  14. Childhood physical abuse and midlife physical health: testing a multi-pathway life course model.

    PubMed

    Springer, Kristen W

    2009-07-01

    Although prior research has established that childhood abuse adversely affects midlife physical health, it is unclear how abuse continues to harm health decades after the abuse has ended. In this project, I assess four life course pathways (health behaviors, cognition, mental health, and social relation) that plausibly link childhood physical abuse to three midlife physical health outcomes (bronchitis diagnosis, ulcer diagnosis, and general physical health). These three outcomes are etiologically distinct, leading to unique testable hypotheses. Multivariate models controlling for childhood background and early adversity were estimated using data from over 3000 respondents in the Wisconsin Longitudinal Study, USA. The results indicate that midlife social relations and cognition do not function as pathways for any outcome. However, smoking is a crucial pathway connecting childhood abuse with bronchitis; mental health is important for ulcers; and BMI, smoking, and mental health are paramount for general physical health. These findings suggest that abuse survivors' coping mechanisms can lead to an array of midlife health problems. Furthermore, the results validate the use of etiologically distinct outcomes for understanding plausible causal pathways when using cross-sectional data.

  15. Long life nickel electrodes for a nickel-hydrogen cell. III - Results of an accelerated test and failure analyses

    NASA Astrophysics Data System (ADS)

    Lim, H. S.; Verzwyvelt, S. A.

    Nineteen different designs of nickel electrodes were tested in Ni/H2 boiler plate cells in an accelerated low earth orbit cycle regime to the end of their life. The failure analyses of these cells showed that the major performance changes due to the cycling was a severe reduction of their high rate discharge capability rather than an absolute capacity reduction. Many physical changes of the nickel electrodes were observed after the cycling test. These changes include dimensional expansion, sinter rupture, loose black powdering of the active material, morphology changes, active material migration, increase of pore volume, change of pore distribution, and increase of surface area. All of these were caused by active material expansion with cycling. Among these changes, the morphology change which involves migration of active material away from the current collecting nickel sinter appears to be that most responsible for the reduction of the rate capability.

  16. Long life nickel electrodes for a nickel-hydrogen cell. III - Results of an accelerated test and failure analyses

    NASA Technical Reports Server (NTRS)

    Lim, H. S.; Verzwyvelt, S. A.

    1984-01-01

    Nineteen different designs of nickel electrodes were tested in Ni/H2 boiler plate cells in an accelerated low earth orbit cycle regime to the end of their life. The failure analyses of these cells showed that the major performance changes due to the cycling was a severe reduction of their high rate discharge capability rather than an absolute capacity reduction. Many physical changes of the nickel electrodes were observed after the cycling test. These changes include dimensional expansion, sinter rupture, loose black powdering of the active material, morphology changes, active material migration, increase of pore volume, change of pore distribution, and increase of surface area. All of these were caused by active material expansion with cycling. Among these changes, the morphology change which involves migration of active material away from the current collecting nickel sinter appears to be that most responsible for the reduction of the rate capability.

  17. Life sciences Spacelab Mission Development test 3 (SMD 3) data management report

    NASA Technical Reports Server (NTRS)

    Moseley, E. C.

    1977-01-01

    Development of a permanent data system for SMD tests was studied that would simulate all elements of the shuttle onboard, telemetry, and ground data systems that are involved with spacelab operations. The onboard data system (ODS) and the ground data system (GDS) were utilized. The air-to-ground link was simulated by a hardwired computer-to-computer interface. A patch board system was used on board to select experiment inputs, and the downlink configuration from the ODS was changed by a crew keyboard entry to support each experiment. The ODS provided a CRT display of experiment parameters to enable the crew to monitor experiment performance. An onboard analog system, with recording capability, was installed to handle high rate data and to provide a backup to the digital system. The GDS accomplished engineering unit conversion and limit sensing, and provided realtime parameter display on CRT's in the science monitoring area and the test control area.

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

    NASA Technical Reports Server (NTRS)

    Izenson, Michael G.; Chen, Weibo; McCormick, John; Paul, Heather L.; Jennings, Mallory A.

    2012-01-01

    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 future space suits. The blower includes a custom-designed motor that has significantly improved its efficiency. We have measured the blower s head/flow performance and power consumption under conditions that simulate both the normal and buddy mode operating points. We have operated the blower for TBD hours and demonstrated safe operation in an oxygen test loop at prototypical pressures. We also demonstrated operation with simulated lunar dust.

  19. Wind-tunnel Tests of a Hall High-life Wing

    NASA Technical Reports Server (NTRS)

    Weick, Fred E; Sanders, Robert

    1932-01-01

    Wind-tunnel tests have been made to find the lift, drag, and center-of-pressure characteristics of a Hall high-lift wing model. The Hall wing is essentially a split-flap airfoil with an internal air passage. Air enters the passage through an opening in the lower surface somewhat back of and parallel to the leading edge, and flows out through an opening made by deflecting the rear portion of the under surface downward as a flap. For ordinary flight conditions the front opening and the rear flap can be closed, providing in effect a conventional airfoil (the Clark Y in this case). The tests were made with various flap settings and with the entrance to the passage both open and closed. The highest lift coefficient found, C(sub L) = 2.08, was obtained with the passage closed.

  20. Long life testing of oxide-coated iridium/rhenium rockets

    NASA Astrophysics Data System (ADS)

    Reed, Brian D.

    1995-09-01

    22-N class rockets, composed of a rhenium (Re) substrate, an iridium (Ir) coating, and an additional composite coating consisting of Ir and a ceramic oxide, were tested on gaseous oxygen/gaseous hydrogen (GO2/GH2) propellants. Two rockets were tested, one for nearly 39 hours at a nominal mixture ratio (MR) of 4.6 and chamber pressure (Pc) of 469 kPa, and the other for over 13 hours at a nominal MR of 5.8 and 621 kPa Pc. Four additional Ir/Re rockets, with a composite Ir-oxide coating fabricated using a modified process, were also tested, including one for 1.3 hours at a nominal MR of 16.7 and Pc of 503 kPa. The long lifetimes demonstrated on low MR GO2/GH2 suggest greatly extended chamber lifetimes (tens of hours) in the relatively low oxidizing combustion environments of Earth storable propellants. The oxide coatings could also serve as a protective coating in the near injector region, where a still-mixing flowfield may cause degradation of the Ir layer. Operation at MR close to 17 suggests that oxide-coated Ir/Re rockets could be used in severely oxidizing combustion environments, such as high MR GO2/GH2, oxygen/hydrocarbon, and liquid gun propellants.

  1. Long Life Testing of Oxide-Coated Iridium/Rhenium Rockets

    NASA Technical Reports Server (NTRS)

    Reed, Brian D.

    1995-01-01

    22-N class rockets, composed of a rhenium (Re) substrate, an iridium (Ir) coating, and an additional composite coating consisting of Ir and a ceramic oxide, were tested on gaseous oxygen/gaseous hydrogen (GO2/GH2) propellants. Two rockets were tested, one for nearly 39 hours at a nominal mixture ratio (MR) of 4.6 and chamber pressure (Pc) of 469 kPa, and the other for over 13 hours at a nominal MR of 5.8 and 621 kPa Pc. Four additional Ir/Re rockets, with a composite Ir-oxide coating fabricated using a modified process, were also tested, including one for 1.3 hours at a nominal MR of 16.7 and Pc of 503 kPa. The long lifetimes demonstrated on low MR GO2/GH2 suggest greatly extended chamber lifetimes (tens of hours) in the relatively low oxidizing combustion environments of Earth storable propellants. The oxide coatings could also serve as a protective coating in the near injector region, where a still-mixing flowfield may cause degradation of the Ir layer. Operation at MR close to 17 suggests that oxide-coated Ir/Re rockets could be used in severely oxidizing combustion environments, such as high MR GO2/GH2, oxygen/hydrocarbon, and liquid gun propellants.

  2. Life testing of the vapor compression distillation urine processor assembly (VCD/UPA) at the Marshall Space Flight Center.

    PubMed

    Wieland, P

    1998-01-01

    Wastewater and urine generated on the International Space Station (ISS) 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 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 operating lives of approximately 4800 h, equivalent to 3.9 years of operation on ISS for a crew of three at an average processing rate of 1.76 kg/h (3.87 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 h 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. PMID:11540460

  3. 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...

  4. 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...

  5. Full-life chronic toxicity of sodium salts to the mayfly Neocloeon triangulifer in tests with laboratory cultured food.

    PubMed

    Soucek, David J; Dickinson, Amy

    2015-09-01

    Although insects occur in nearly all freshwater ecosystems, few sensitive insect models exist for use in determining the toxicity of contaminants. The objectives of the present study were to adapt previously developed culturing and toxicity testing methods for the mayfly Neocloeon triangulifer (Ephemeroptera: Baetidae), and to further develop a method for chronic toxicity tests spanning organism ages of less than 24 h post hatch to adult emergence, using a laboratory cultured diatom diet. The authors conducted 96-h fed acute tests and full-life chronic toxicity tests with sodium chloride, sodium nitrate, and sodium sulfate. The authors generated 96-h median lethal concentrations (LC50s) of 1062 mg Cl/L (mean of 3 tests), 179 mg N-NO3 /L, and 1227 mg SO4 /L. Acute to chronic ratios ranged from 2.1 to 6.4 for chloride, 2.5 to 5.1 for nitrate, and 2.3 to 8.5 for sulfate. The endpoints related to survival and development time were consistently the most sensitive in the tests. The chronic values generated for chloride were in the same range as those generated by others using natural foods. Furthermore, our weight-versus-fecundity plots were similar to those previously published using the food culturing method on which the present authors' method was based, indicating good potential for standardization. The authors believe that the continued use of this sensitive mayfly species in laboratory studies will help to close the gap in understanding between standard laboratory toxicity test results and field-based observations of community impairment.

  6. Life Testing of the Hollow Cathode Plasma Contactor for the ProSEDS Mission

    NASA Technical Reports Server (NTRS)

    Vaughn, Jason A.; Schneider, Todd A.; Finckenor, Miria M.; Munafo, Paul M. (Technical Monitor)

    2001-01-01

    The Propulsive Small Expendable Deployer System (ProSEDS) mission is designed to provide an on-orbit demonstration of the electrodynamic propulsion capabilities of tethers in space. The ProSEDS experiment will be a secondary payload on a Delta 11 unmanned expendable booster. A 5-km conductive tether is attached to the Delta 11 second stage and collects current from the low Earth orbit (LEO) plasma. A hollow cathode plasma contactor emits the collected electrons from the Delta II, completing the electrical circuit with the ambient plasma. The current flowing through the tether generates thrust based on the Lorentz Force Law. The thrust will be generated opposite to the velocity vector, slowing down the spacecraft and causing it to de-orbit in approximately 14 days compared to the normal 6 months. A 10-km non-conductive tether is between the conductive tether and an endmass containing several scientific instruments. The ProSEDS mission lifetime was set at I day because most of the primary objectives can be met in that time. The extended ProSEDS mission will be for as many days as possible, until the Delta 11 second stage burns up or the tether is severed by a micrometeoroid or space debris particle. The Hollow Cathode Plasma Contactor (HCPC) unit has been designed for a 12-day mission. Because of the science requirements to measure the background ambient plasma, the HCPC must operate on a duty cycle. Later in the ProSEDS mission, the HCPC is operated in a manner to allow charging of the secondary battery. Due to the unusual operating requirements by the ProSEDS mission, a development unit of the HCPC was built for thorough testing. This developmental unit was tested for a simulated ProSEDS mission, with measurements of the ability to start and stop during the duty cycle. These tests also provided valuable data for the ProSEDS software requirements. Qualification tests of the HCPC flight hardware are also discussed.

  7. Life-Cycle Assessment of Energy and Environmental Impacts of LED Lighting Products, Part 3: LED Environmental Testing

    SciTech Connect

    Tuenge, Jason R.; Hollomon, Brad; Dillon, Heather E.; Snowden-Swan, Lesley J.

    2013-03-01

    This report covers the third part of a larger U.S. Department of Energy (DOE) project to assess the life-cycle environmental and resource impacts in the manufacturing, transport, use, and disposal of light-emitting diode (LED) lighting products in relation to incumbent lighting technologies. All three reports are available on the DOE website (www.ssl.energy.gov/tech_reports.html). • Part 1: Review of the Life-Cycle Energy Consumption of Incandescent, Compact Fluorescent and LED Lamps; • Part 2: LED Manufacturing and Performance; • Part 3: LED Environmental Testing. Parts 1 and 2 were published in February and June 2012, respectively. The Part 1 report included a summary of the life-cycle assessment (LCA) process and methodology, provided a literature review of more than 25 existing LCA studies of various lamp types, and performed a meta-analysis comparing LED lamps with incandescent and compact fluorescent lamps (CFLs). Drawing from the Part 1 findings, Part 2 performed a more detailed assessment of the LED manufacturing process and used these findings to provide a comparative LCA taking into consideration a wider range of environmental impacts. Both reports concluded that the life-cycle environmental impact of a given lamp is dominated by the energy used during lamp operation—the upstream generation of electricity drives the total environmental footprint of the product. However, a more detailed understanding of end-of-life disposal considerations for LED products has become increasingly important as their installation base has grown. The Part 3 study (reported herein) was undertaken to augment the LCA findings with chemical analysis of a variety of LED, CFL, and incandescent lamps using standard testing procedures. A total of 22 samples, representing 11 different models, were tested to determine whether any of 17 elements were present at levels exceeding California or Federal regulatory thresholds for hazardous waste. Key findings include: • The selected

  8. Genetic analysis of a temperament test as a tool to select against everyday life fearfulness in Rough Collie.

    PubMed

    Arvelius, P; Eken Asp, H; Fikse, W F; Strandberg, E; Nilsson, K

    2014-11-01

    Fear-related problems are common among Rough Collies in Sweden. Annually, on average, >200 Rough Collies are subjected to the dog mentality assessment (DMA), a temperament test during which 33 behavioral reactions are rated. Previous research has shown that a dog's DMA result can be condensed into 5 underlying personality traits. The aim of the study was to evaluate if it is possible to use the DMA for selection for temperament in Swedish Rough Collies, in particular to decrease everyday life fearfulness. We also wanted to compare 2 methods to compute the personality traits: summated scales (SS) and factor scores (FS). The DMA data for 2,953 Rough Collies were used to estimate genetic parameters for the 5 personality traits (both SS and FS), using a linear animal model including fixed effects of sex, year and month of test, and random effects of litter, judge, test occasion, genetic effect of the individual, and residual. Age at test was included as linear and quadratic regressions. The DMA personality trait heritability estimates ranged from 0.13 to 0.25. The SS showed greater or equal heritability estimates compared with the FS. To validate the DMA, data on everyday life behavior of 1,738 Rough Collies were collected using an extended version of the Canine Behavioral Assessment and Research Questionnaire. Each dog's questionnaire result was condensed into 18 underlying behavioral subscales. Genetic parameters for the subscales were estimated using a linear animal model, including a fixed effect of sex and random genetic effect of the individual and residual. Age when the questionnaire was completed was included as linear and quadratic regressions. Heritability estimates for the questionnaire subscales were 0.06 to 0.36. There were high and significant genetic correlations between DMA personality traits and questionnaire subscales. For instance, the DMA personality trait Curiosity/Fearlessness correlated strongly genetically to the questionnaire subscale Non

  9. Role of stable isotopes in life--testing isotopic resonance hypothesis.

    PubMed

    Zubarev, Roman A

    2011-04-01

    Stable isotopes of most important biological elements, such as C, H, N and O, affect living organisms. In rapidly growing species, deuterium and to a lesser extent other heavy isotopes reduce the growth rate. At least for deuterium it is known that its depletion also negatively impacts the speed of biological processes. As a rule, living organisms "resist" changes in their isotopic environment, preferring natural isotopic abundances. This preference could be due to evolutionary optimization; an additional effect could be due to the presence of the "isotopic resonance". The isotopic resonance phenomenon has been linked to the choice of earliest amino acids, and thus affected the evolution of genetic code. To test the isotopic resonance hypothesis, literature data were analyzed against quantitative and qualitative predictions of the hypothesis. Four studies provided five independent datasets, each in very good quantitative agreement with the predictions. Thus, the isotopic resonance hypothesis is no longer simply plausible; it can now be deemed likely. Additional testing is needed, however, before full acceptance of this hypothesis.

  10. Cycle life test and failure model of nickel-hydrogen cells

    NASA Technical Reports Server (NTRS)

    Smithrick, J. J.

    1983-01-01

    Six ampere hour individual pressure vessel nickel hydrogen cells were charge/discharge cycled to failure. Failure as used here is defined to occur when the end of discharge voltage degraded to 0.9 volts. They were cycled under a low earth orbit cycle regime to a deep depth of discharge (80 percent of rated ampere hour capacity). Both cell designs were fabricated by the same manufacturer and represent current state of the art. A failure model was advanced which suggests both cell designs have inadequate volume tolerance characteristics. The limited existing data base at a deep depth of discharge (DOD) was expanded. Two cells of each design were cycled. One COMSAT cell failed at cycle 1712 and the other failed at cycle 1875. For the Air Force/Hughes cells, one cell failed at cycle 2250 and the other failed at cycle 2638. All cells, of both designs, failed due to low end of discharge voltage (0.9 volts). No cell failed due to electrical shorts. After cell failure, three different reconditioning tests (deep discharge, physical reorientation, and open circuit voltage stand) were conducted on all cells of each design. A fourth reconditioning test (electrolyte addition) was conducted on one cell of each design. In addition post cycle cell teardown and failure analysis were performed on the one cell of each design which did not have electrolyte added after failure.

  11. Design and Testing of the Variable Electronic Regulator (VER) for Portable Life Support System (PLSS) Development

    NASA Technical Reports Server (NTRS)

    Campbell, Colin; Pryzbyla, Ken

    2010-01-01

    The next generation space suit requires additional capabilities for controlling and adjusting internal pressure compared to that of historical designs. Next generation suit pressures will range from slight pressure, for astronaut prebreathe comfort, to hyperbaric pressure levels for emergency medical treatment of decompression sickness. Historical regulator designs for space suits have been purely mechanical in nature with the performance aspects typical of such designs such as droop. This paper discusses a new approach to providing the tighter regulation band possible with electronic regulation while mitigating the typical short-comings of electronic control: power consumption, loss of power failure modes, start-up time, and reliability. The paper will also address the bench top prototype development and subsequent performance testing with comparison back to mechanical regulators as a baseline.

  12. Proposed minimum requirements for the operational characteristics and testing of closed circuit life support system control electronics.

    PubMed

    Kirk, J C

    1998-01-01

    The popularization and transformation of scuba diving into a broadly practiced sport has served to ignite the interest of technically oriented divers into ever more demanding areas. This, along with the gradual release of military data, equipment, and techniques of closed circuit underwater breathing apparatus, has resulted in a virtual explosion of semiclosed and closed circuit systems for divers. Although many of these systems have been carefully thought out by capable designers, the impulse to rush to market with equipment that has not been fully developed and carefully tested is irresistible to marketers. In addition, the presence of systems developed by well-intentioned and otherwise competent designers who are, nonetheless, inexperienced in the field of life support can result in the sale of failure-prone equipment to divers who lack the knowledge and skills to identify deficiencies before disaster occurs. For this reason, a set of industry standards establishing minimum requirements and testing is needed to guide the designers of this equipment, and to protect the user community from incomplete or inadequate design. Many different technologies go into the development of closed circuit scuba. One key area is the design of electronics to monitor and maintain the critical gas mixtures of the closed circuit loop. Much of the system reliability and inherent danger is resident in the design of the circuitry and the software (if any) that runs it. This article will present a set of proposed minimum requirements, with the goal of establishing a dialog for the creation of guidelines for the classification, rating, design, and testing of embedded electronics for life support systems used in closed circuit applications. These guidelines will serve as the foundation for the later creation of a set of industry specifications.

  13. A comparative study of an accelerated life-test model and a toxicokinetics-based model for the analysis of Porcellio scaber survival data.

    PubMed

    Ren, Shijin

    2004-01-01

    Statistical models have long been used for reliability analysis and risk assessment. In the present study, an accelerated life-test model was used to analyze a set of dose-time-response data obtained with the terrestrial isopod Porcellio scaber. Survival data were experimentally obtained by exposing P. scaber to diazinon (a nonpersistent insecticide) at six concentrations between 2 and 11.31 microg/g (toxicant/soil). Survival data are presented on a weekly basis. The accelerated life-test model assumed a log-normal distribution and constant variance across all diazinon concentrations. Model parameters were obtained by maximum likelihood estimation. The accelerated life-test model was compared to a toxicokinetics-based model reported in the literature. Survival predictions made by both models were compared with the observed data. Both the accelerated life-test model and the toxicokinetics-based model underestimated toxicity at a diazinon concentration of 8 microg/g. Overall, however, the accelerated life-test model outperformed the toxicokinetics-based model, with survival predictions closer to the observed data in most cases and a stronger correlation between predicted and observed survivals. However, as a statistical model, the accelerated life-test model did not reveal mechanistic information, and only statistical and distributional interpretations of its model parameters could be made.

  14. Calculation of the Phenix end-of-life test in natural circulation with the CATHARE code

    SciTech Connect

    Maas, L.; Cocheme, F.

    2012-07-01

    The Inst. of Radiological Protection and Nuclear Safety (IRSN) acts as technical support to French public authorities. As such, IRSN is in charge of safety assessment of operating and under construction reactors, as well as future projects. In this framework, one current objective of IRSN is to evaluate the ability and accuracy of numerical tools to foresee consequences of accidents. One of the advantages pointed up for fast reactors cooled by heavy liquid metal is the possibility of decay heat removal based on natural convection. The promotion of this passive cooling mode in future safety demonstrations will involve the use of adapted and validated numerical codes. After the final shutdown of the Phenix sodium cooled fast reactor in 2009, a set of tests covering different areas was conducted for code validation, including a natural circulation test in the primary circuit. Experimental data were issued by CEA to organize a benchmark exercise in the frame of an IAEA Coordinated Research Project (CRP), with the objective to assess the system-codes capability in simulating the thermal-hydraulics behavior of sodium cooled fast reactors in such accidental conditions. IRSN participated to this benchmark with the CATHARE code. This code, co-developed by CEA, EDF, AREVA and IRSN and widely used for PWR safety studies, was recently extended for sodium applications. This paper presents the CATHARE modeling of the Phenix primary circuit and the results obtained. A relatively good agreement was found with available measurements considering the experimental uncertainties. This work stressed the local aspects of phenomena occurring during the natural convection establishment and the limits of a 0D/1D approach. (authors)

  15. Environmental test report on the CTI-Cryogenics 1-watt integral Stirling cooler (long-life HD-1033d). Final report, 16 June-24 July 1988

    SciTech Connect

    Doggett, G.; Dunmire, H.; Samuels, R.; Shaffer, J.

    1989-04-01

    This final report describes and provides the data on the environmental testing of the CTI-Cryogenics 1-Watt Integral Stirling Cooler (Long-Life HD-1033D). The 1-Watt Integral Cooler (HD-1033B/C) is currently used in the M1 FLIR, M60 FLIR, and the Advanced Attack Helicopter FLIR. The long life cooler (clearance seal) improves life of the cooler by approximately two and one half times. C2NVEO evaluated the cooler performance at environmental extremes per the purchase description, PD-0182-001(CR). The cooler successfully passed all the environmental tests with no failures.

  16. Crop production data for bioregenerative life support: Observations from testing at NASA's Kennedy Space Center

    NASA Astrophysics Data System (ADS)

    Wheeler, R. M.; Mackowiak, C. L.; Stutte, G. W.; Yorio, N. C.; Ruffe, L. M.; Sager, J. C.; Knott, W. M.

    NASA s Biomass Production Chamber BPC at Kennedy Space Center was decommissioned ca 1998 but in the preceding decade several crop tests were conducted that have not been reported in the open literature These included monoculture studies with wheat soybean potato and tomato For each of these studies 20 m 2 of crops were grown in an atmospherically closed chamber 113 m 3 vol using a nutrient film hydroponic technique along with elevated CO 2 1000 or 1200 mu mol mol -1 Canopy light PAR levels ranged from 30 to 85 mol m -2 d -1 depending on the crop and selected photoperiod Total biomass DM productivities reached 40 g m -2 d -1 for wheat 16 g m -2 d -1 for soybean 33 g m -2 d -1 for potato and 20 g m -2 d -1 for tomato Edible biomass DM productivities reached 13 g m -2 d -1 for wheat 6 g m -2 d -1 for soybean 20 g m -2 d -1 for potato and 10 g m -2 d -1 for tomato The highest radiation use efficiencies for biomass were 0 60 g DM mol -1 PAR for wheat 0 50 g mol -1 for soybean 0 95 g mol -1 for potato and 0 51 g mol -1 for tomato The highest radiation use efficiencies for edible biomass were 0 22 g DM mol -1 for wheat 0 18 g mol -1 for soybean 0 58 g mol -1 for potato and 0 25 g mol -1 for tomato Use of transplanting cycles or spacing techniques to reduce open gaps between plants early in growth would have improved productivities and radiation use efficiencies for soybeans potatoes and

  17. Testing life history predictions in a long-lived seabird: a population matrix approach with improved parameter estimation

    USGS Publications Warehouse

    Doherty, P.F.; Schreiber, E.A.; Nichols, J.D.; Hines, J.E.; Link, W.A.; Schenk, G.A.; Schreiber, R.W.

    2004-01-01

    Life history theory and associated empirical generalizations predict that population growth rate (lambda) in long-lived animals should be most sensitive to adult survival; the rates to which lambda is most sensitive should be those with the smallest temporal variances; and stochastic environmental events should most affect the rates to which lambda is least sensitive. To date, most analyses attempting to examine these predictions have been inadequate, their validity being called into question by problems in estimating parameters, problems in estimating the variability of parameters, and problems in measuring population sensitivities to parameters. We use improved methodologies in these three areas and test these life-history predictions in a population of red-tailed tropicbirds (Phaethon rubricauda). We support our first prediction that lambda is most sensitive to survival rates. However the support for the second prediction that these rates have the smallest temporal variance was equivocal. Previous support for the second prediction may be an artifact of a high survival estimate near the upper boundary of 1 and not a result of natural selection canalizing variances alone. We did not support our third prediction that effects of environmental stochasticity (El Ni?o) would most likely be detected in vital rates to which lambda was least sensitive and which are thought to have high temporal variances. Comparative data-sets on other seabirds, within and among orders, and in other locations, are needed to understand these environmental effects.

  18. Quality of Life and Psychological State in Chinese Breast Cancer Patients Who Received BRCA1/2 Genetic Testing

    PubMed Central

    Qiu, Jiajia; Guan, Jiaqin; Yang, Xiaochen; Wu, Jiong; Liu, Guangyu; Di, Genhong; Chen, Canming; Hou, Yifeng; Han, Qixia; Shen, Zhenzhou; Shao, Zhimin; Hu, Zhen

    2016-01-01

    Background This study aims to understand the quality of life (QOL) and psychological state (PS) of Chinese breast cancer patients who received BRCA1/2 genetic testing; to examine the psychological changes between BRCA1/2 mutation carriers and non-carriers; and to further explore the psychological experience of BRCA1/2 mutation carriers. Methods This study was combined with quantitative and qualitative designs. First, we performed a quantitative investigation using FACT-B (Chinese version) and Irritability, Depression and Anxiety scale (IDA) to assess the QOL and PS in breast cancer patients who received BRCA1/2 genetic testing. Then semi-structured in-depth qualitative interviews among 13 mutation carriers were conducted in hospital. Results Results from the quantitative study showed QOL scores were relatively high and the IDA scores were relatively low among the patients, and there was no significant difference in the QOL or IDA scores between non-carriers and carriers. Based on the qualitative analysis, four main themes emerged: (1) Finding the reason for having breast cancer; (2) Negative emotions; (3) Behavioral changes; (4) Lack of information. Conclusions The present study showed that QOL and PS are good among the breast cancer patients who received genetic testing. Genetic testing itself does not cause long psychosocial effects. BRCA1/2 mutation carriers may have certain negative emotions at the first stage they knew the testing results and may initiate behavioral and lifestyle changes. The patients with a BRCA1/2 mutation desire knowledge with regard to genetic aspects in mainland China. Professional information and advice can be provided to relieve the patients’ negative emotions when they were informed of gene defect. PMID:27428375

  19. A novel test method to determine the filter material service life of decentralized systems treating runoff from traffic areas.

    PubMed

    Huber, Maximilian; Welker, Antje; Dierschke, Martina; Drewes, Jörg E; Helmreich, Brigitte

    2016-09-01

    In recent years, there has been a significant increase in the development and application of technical decentralized filter systems for the treatment of runoff from traffic areas. However, there are still many uncertainties regarding the service life and the performance of filter materials that are employed in decentralized treatment systems. These filter media are designed to prevent the transport of pollutants into the environment. A novel pilot-scale test method was developed to determine - within a few days - the service lives and long-term removal efficiencies for dissolved heavy metals in stormwater treatment systems. The proposed method consists of several steps including preloading the filter media in a pilot-scale model with copper and zinc by a load of n-1 years of the estimated service life (n). Subsequently, three representative rain events are simulated to evaluate the long-term performance by dissolved copper and zinc during the last year of application. The presented results, which verified the applicability of this method, were obtained for three filter channel systems and six filter shaft systems. The performance of the evaluated systems varied largely for both tested heavy metals and during all three simulated rain events. A validation of the pilot-scale assessment method with field measurements was also performed for two systems. Findings of this study suggest that this novel method does provide a standardized and accurate estimation of service intervals of decentralized treatment systems employing various filter materials. The method also provides regulatory authorities, designers, and operators with an objective basis for performance assessment and supports stormwater managers to make decisions for the installation of such decentralized treatment systems. PMID:27179341

  20. Overview of Microbiological Tests Performed During the Design of the International Space Station Environmental Control and Life Support Systems

    NASA Technical Reports Server (NTRS)

    Roman, Monsi C.; Mittelman, Marc W.

    2010-01-01

    The design and manufacturing of the main Environmental Control and Life Support Systems (ECLSS) for the United States segments of the International Space Station (ISS) was an involved process that started in the late 1980's, with the assessment and testing of competing technologies that could be used to clean the air and recycle water. It culminated in 2009 with the delivery and successful activation of the Water Recovery System (WRS) water processor (WP). The ECLSS required the work of a team of engineers and scientist working together to develop systems that could clean and/or recycle human metabolic loads to maintain a clean atmosphere and provide the crew clean water. One of the main goals of the ECLSS is to minimize the time spent by the crew worrying about vital resources not available in the vacuum of space, which allows them to spend most of their time learning to live in a microgravity environment many miles from the comforts of Earth and working on science experiments. Microorganisms are a significant part of the human body as well as part of the environment that we live in. Therefore, the ISS ECLSS design had to take into account the effect microorganisms have on the quality of stored water and wastewater, as well as that of the air systems. Hardware performance issues impacted by the accumulation of biofilm and/or microbiologically influenced corrosion were also studied during the ECLSS development stages. Many of the tests that were performed had to take into account the unique aspects of a microgravity environment as well as the challenge of understanding how to design systems that could not be sterilized or maintained in a sterile state. This paper will summarize the work of several studies that were performed to assess the impacts and/or to minimize the effects of microorganisms in the design of a closed loop life support system.

  1. A novel test method to determine the filter material service life of decentralized systems treating runoff from traffic areas.

    PubMed

    Huber, Maximilian; Welker, Antje; Dierschke, Martina; Drewes, Jörg E; Helmreich, Brigitte

    2016-09-01

    In recent years, there has been a significant increase in the development and application of technical decentralized filter systems for the treatment of runoff from traffic areas. However, there are still many uncertainties regarding the service life and the performance of filter materials that are employed in decentralized treatment systems. These filter media are designed to prevent the transport of pollutants into the environment. A novel pilot-scale test method was developed to determine - within a few days - the service lives and long-term removal efficiencies for dissolved heavy metals in stormwater treatment systems. The proposed method consists of several steps including preloading the filter media in a pilot-scale model with copper and zinc by a load of n-1 years of the estimated service life (n). Subsequently, three representative rain events are simulated to evaluate the long-term performance by dissolved copper and zinc during the last year of application. The presented results, which verified the applicability of this method, were obtained for three filter channel systems and six filter shaft systems. The performance of the evaluated systems varied largely for both tested heavy metals and during all three simulated rain events. A validation of the pilot-scale assessment method with field measurements was also performed for two systems. Findings of this study suggest that this novel method does provide a standardized and accurate estimation of service intervals of decentralized treatment systems employing various filter materials. The method also provides regulatory authorities, designers, and operators with an objective basis for performance assessment and supports stormwater managers to make decisions for the installation of such decentralized treatment systems.

  2. Experimentally decoupling reproductive investment from energy storage to test the functional basis of a life-history trade-off.

    PubMed

    Cox, Robert M; Lovern, Matthew B; Calsbeek, Ryan

    2014-07-01

    The ubiquitous life-history trade-off between reproduction and survival has long been hypothesized to reflect underlying energy-allocation trade-offs between reproductive investment and processes related to self-maintenance. Although recent work has questioned whether energy-allocation models provide sufficient explanations for the survival cost of reproduction, direct tests of this hypothesis are rare, especially in wild populations. This hypothesis was tested in a wild population of brown anole lizards (Anolis sagrei) using a two-step experiment. First, stepwise variation in reproductive investment was created using unilateral and bilateral ovariectomy (OVX) along with intact (SHAM) control. Next, this manipulation was decoupled from its downstream effects on energy storage by surgically ablating the abdominal fat stores from half of the females in each reproductive treatment. As predicted, unilateral OVX (intermediate reproductive investment) induced levels of growth, body condition, fat storage and breeding-season survival that were intermediate between the high levels of bilateral OVX (no reproductive investment) and the low levels of SHAM (full reproductive investment). Ablation of abdominal fat bodies had a strong and persistent effect on energy stores, but it did not influence post-breeding survival in any of the three reproductive treatments. This suggests that the energetic savings of reduced reproductive investment do not directly enhance post-breeding survival, with the caveat that only one aspect of energy storage was manipulated and OVX itself had no overall effect on post-breeding survival. This study supports the emerging view that simple energy-allocation models may often be insufficient as explanations for the life-history trade-off between reproduction and survival.

  3. The effective and environmental half-life of 137Cs at Coral Islands at the former US nuclear test site.

    PubMed

    Robison, William L; Conrado, Cynthia L; Bogen, Kenneth T; Stoker, A Carol

    2003-01-01

    The United States (US) conducted nuclear weapons testing from 1946 to 1958 at Bikini and Enewetak Atolls in the northern Marshall Islands. Based on previous detailed dose assessments for Bikini, Enewetak, Rongelap, and Utirik Atolls over a period of 28 years, cesium-137 (137Cs) at Bikini Atoll contributes about 85-89% of the total estimated dose through the terrestrial food chain as a result of uptake of 137Cs by food crops. The estimated integral 30, 50, and 70-year doses were based on the radiological decay of 137Cs (30-year half-life) and other radionuclides. However, there is a continuing inventory of 137Cs and 90Sr in the fresh water portion of the groundwater at all contaminated atolls even though the turnover rate of the fresh groundwater is about 5 years. This is evidence that a portion of the soluble fraction of 137Cs and 90Sr inventory in the soil is lost by transport to groundwater when rainfall is heavy enough to cause recharge of the lens, resulting in loss of 137Cs from the soil column and root zone of the plants. This loss is in addition to that caused by radioactive decay. The effective rate of loss was determined by two methods: (1) indirectly, from time-dependent studies of the 137Cs concentration in leaves of Pisonia grandis, Guettarda specosia, Tournefortia argentea (also called Messerschmidia), Scaevola taccada, and fruit from Pandanus and coconut trees (Cocos nucifera L.), and (2) more directly, by evaluating the 137Cs/90Sr ratios at Bikini Atoll. The mean (and its lower and upper 95% confidence limits) for effective half-life and for environmental-loss half-life (ELH) based on all the trees studied on Rongelap, Bikini, and Enewetak Atolls are 8.5 years (8.0 years, 9.8 years), and 12 years (11 years, 15 years), respectively. The ELH based on the 137Cs/90Sr ratios in soil in 1987 relative to the 137Cs/90Sr ratios at the time of deposition in 1954 is less than 17 years. The magnitude of the decrease below 17 years depends on the ELH for 90Sr

  4. The effective and environmental half-life of 137Cs at Coral Islands at the former US nuclear test site.

    PubMed

    Robison, William L; Conrado, Cynthia L; Bogen, Kenneth T; Stoker, A Carol

    2003-01-01

    The United States (US) conducted nuclear weapons testing from 1946 to 1958 at Bikini and Enewetak Atolls in the northern Marshall Islands. Based on previous detailed dose assessments for Bikini, Enewetak, Rongelap, and Utirik Atolls over a period of 28 years, cesium-137 (137Cs) at Bikini Atoll contributes about 85-89% of the total estimated dose through the terrestrial food chain as a result of uptake of 137Cs by food crops. The estimated integral 30, 50, and 70-year doses were based on the radiological decay of 137Cs (30-year half-life) and other radionuclides. However, there is a continuing inventory of 137Cs and 90Sr in the fresh water portion of the groundwater at all contaminated atolls even though the turnover rate of the fresh groundwater is about 5 years. This is evidence that a portion of the soluble fraction of 137Cs and 90Sr inventory in the soil is lost by transport to groundwater when rainfall is heavy enough to cause recharge of the lens, resulting in loss of 137Cs from the soil column and root zone of the plants. This loss is in addition to that caused by radioactive decay. The effective rate of loss was determined by two methods: (1) indirectly, from time-dependent studies of the 137Cs concentration in leaves of Pisonia grandis, Guettarda specosia, Tournefortia argentea (also called Messerschmidia), Scaevola taccada, and fruit from Pandanus and coconut trees (Cocos nucifera L.), and (2) more directly, by evaluating the 137Cs/90Sr ratios at Bikini Atoll. The mean (and its lower and upper 95% confidence limits) for effective half-life and for environmental-loss half-life (ELH) based on all the trees studied on Rongelap, Bikini, and Enewetak Atolls are 8.5 years (8.0 years, 9.8 years), and 12 years (11 years, 15 years), respectively. The ELH based on the 137Cs/90Sr ratios in soil in 1987 relative to the 137Cs/90Sr ratios at the time of deposition in 1954 is less than 17 years. The magnitude of the decrease below 17 years depends on the ELH for 90Sr

  5. Accelerated test methods for predicting the life of motor materials exposed to refrigerant/lubricant mixtures. Phase 1, Conceptual design: Final report

    SciTech Connect

    Ellis, P.F. II; Ferguson, A.

    1993-08-18

    The federally mandated phase-out of chlorofluorocarbon refrigerants requires screening tests for motor materials compatibility with alternative refrigerant/lubricant mixtures. In the current phase of the program, ARTI is supporting tests of promising candidate refrigeration/lubricant systems in key refrigeration component systems such as bearings and hermetic motor insulation systems to screen for more subtle detrimental effects and allow estimates of motor-compressor life. This report covers: mechanisms of failure of hermetic motor insulation, current methods for estimation of life of hermetic motors, and conceptual design of improved stator simulator device for testing of alternative refrigerant/lubricant mixtures.

  6. Development and usability testing of a web-based cancer symptom and quality-of-life support intervention

    PubMed Central

    Wolpin, SE; Halpenny, B; Whitman, G; McReynolds, J; Stewart, M; Lober, WB; Berry, DL

    2016-01-01

    The feasibility and acceptability of computerized screening and patient-reported outcome measures have been demonstrated in the literature. However, patient-centered management of health information entails two challenges: gathering and presenting data using “patient-tailored” methods and supporting “patient-control” of health information. The design and development of many symptom and quality-of-life information systems have not included opportunities for systematically collecting and analyzing user input. As part of a larger clinical trial, the Electronic Self-Report Assessment for Cancer–II project, participatory design approaches were used to build and test new features and interfaces for patient/caregiver users. The research questions centered on patient/caregiver preferences with regard to the following: (a) content, (b) user interface needs, (c) patient-oriented summary, and (d) patient-controlled sharing of information with family, caregivers, and clinicians. Mixed methods were used with an emphasis on qualitative approaches; focus groups and individual usability tests were the primary research methods. Focus group data were content analyzed, while individual usability sessions were assessed with both qualitative and quantitative methods. We identified 12 key patient/caregiver preferences through focus groups with 6 participants. We implemented seven of these preferences during the iterative design process. We deferred development for some of the preferences due to resource constraints. During individual usability testing (n = 8), we were able to identify 65 usability issues ranging from minor user confusion to critical errors that blocked task completion. The participatory development model that we used led to features and design revisions that were patient centered. We are currently evaluating new approaches for the application interface and for future research pathways. We encourage other researchers to adopt user-centered design approaches

  7. Vibration, acceleration, gravitation, and movement: activity controlled rate adaptive pacing during treadmill exercise testing and daily life activities.

    PubMed

    Candinas, R; Jakob, M; Buckingham, T A; Mattmann, H; Amann, F W

    1997-07-01

    Activity-based sensors for rate adaptive pacing have been available for several years and now include several different types: vibration; acceleration; gravitation; and movement. However, a systematic comparison evaluating the relative advantages and disadvantages of these various sensors has received little study. The purpose of the present study was to compare these sensor subtypes using treadmill testing and an outdoor test circuit, which simulated daily life activities and included both uphill and downhill walking. Pacemakers were strapped on the chest of healthy volunteers and connected to one channel of an ambulatory recording device, which also recorded the subject's intrinsic heart rate. The pacemakers were programmed using an initial treadmill test to standardize the rate responsive parameters for each device. Nine different pacemaker models were studied including 3 vibration-based (Elite, Synchrony, Metros), 4 acceleration-based (Relay, Excel, Ergos, Trilogy), 1 gravitational-based (Swing), and 1 movement-based (Sensorithm) device. All devices demonstrated a prompt rate response with casual walking on flat ground. The vibration-, gravitational-, and movement-based pacemakers showed a pronounced rate decline during more strenuous work, e.g., walking uphill. This phenomenon was absent in the accelerometer-based units. In particular, the vibration- and movement-based units showed a higher rate with walking downhill compared to uphill. An optimally tuned rate behavior on the treadmill usually did not provide an optimal rate behavior during daily activities and there was a tendency to overstimulation during low workload. The development of the two newest sensors (gravitational and movement) did not result in an improved performance of rate response behavior. Overall, the accelerometer-based pacemakers simulated or paralleled sinus rate behavior the most closely.

  8. 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

  9. 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

  10. Quality of life in relation to future mental health problems and offending: Testing the good lives model among detained girls.

    PubMed

    Van Damme, Lore; Hoeve, Machteld; Vermeiren, Robert; Vanderplasschen, Wouter; Colins, Olivier F

    2016-06-01

    Detained girls bear high levels of criminal behavior and mental health problems that are likely to persist into young adulthood. Research with these girls began primarily from a risk management perspective, whereas a strength-based empowering perspective may increase knowledge that could improve rehabilitation. This study examines detained girls' quality of life (QoL) in relation to future mental health problems and offending, thereby testing the strength-based good lives model of offender rehabilitation (GLM). At baseline, 95 girls (Mage = 16.25) completed the World Health Organization QoL instrument to assess their QoL prior to detention in the domains of physical health, psychological health, social relationships, and environment. Six months after discharge, mental health problems and offending were assessed by self-report measures. Structural equation models were conducted to test GLM's proposed (in)direct pathways from QoL (via mental health problems) toward offending. Although we could not find support for GLM's direct negative pathway from QoL to offending, our findings did provide support for GLM's indirect negative pathway via mental health problems to future offending. In addition, we found a direct positive pathway from detained girls' satisfaction with their social relationships to offending after discharge. The current findings support the potential relevance of addressing detained girls' QoL, pursuing the development of new skills, and supporting them to build constructive social contacts. Our findings, however, also show that clinicians should not only focus on strengths but that detecting and modifying mental health problems in this vulnerable group is also warranted. (PsycINFO Database Record PMID:26844913

  11. Pubertal timing and sexual risk behaviors among rural African American male youth: testing a model based on life history theory.

    PubMed

    Kogan, Steven M; Cho, Junhan; Simons, Leslie Gordon; Allen, Kimberly A; Beach, Steven R H; Simons, Ronald L; Gibbons, Frederick X

    2015-04-01

    Life History Theory (LHT), a branch of evolutionary biology, describes how organisms maximize their reproductive success in response to environmental conditions. This theory suggests that challenging environmental conditions will lead to early pubertal maturation, which in turn predicts heightened risky sexual behavior. Although largely confirmed among female adolescents, results with male youth are inconsistent. We tested a set of predictions based on LHT with a sample of 375 African American male youth assessed three times from age 11 to age 16. Harsh, unpredictable community environments and harsh, inconsistent, or unregulated parenting at age 11 were hypothesized to predict pubertal maturation at age 13; pubertal maturation was hypothesized to forecast risky sexual behavior, including early onset of intercourse, substance use during sexual activity, and lifetime numbers of sexual partners. Results were consistent with our hypotheses. Among African American male youth, community environments were a modest but significant predictor of pubertal timing. Among those youth with high negative emotionality, both parenting and community factors predicted pubertal timing. Pubertal timing at age 13 forecast risky sexual behavior at age 16. Results of analyses conducted to determine whether environmental effects on sexual risk behavior were mediated by pubertal timing were not significant. This suggests that, although evolutionary mechanisms may affect pubertal development via contextual influences for sensitive youth, the factors that predict sexual risk behavior depend less on pubertal maturation than LHT suggests. PMID:25501863

  12. EVALUATING THE EFFECTS OF FLY ASH EXPOSURE ON FISH EARLY LIFE STAGES: FATHEAD MINNOW EMBRYO-LARVAL TESTS

    SciTech Connect

    Greeley Jr, Mark Stephen; Elmore, Logan R; McCracken, Kitty

    2012-05-01

    On December 22, 2008, a dike containing fly ash and bottom ash in an 84-acre complex of the Tennessee Valley Authority's (TVA) Kingston Steam Plant in East Tennessee failed and released a large quantity of ash into the adjacent Emory River. Ash deposits extended as far as 4 miles upstream (Emory River mile 6) of the Plant, and some ash was carried as far downstream as Tennessee River mile 564 ({approx}4 miles downstream of the Tennessee River confluence with the Clinch River). A byproduct of coal burning power plants, fly ash contains a variety of metals and other elements which, at sufficient concentrations and in specific forms, can be toxic to biological systems. The effects of fly ash contamination on exposed fish populations depend on the magnitude and duration of exposure, with the most significant risk considered to be the effects of specific ash constituents, especially selenium, on fish early life stages. Uptake by adult female fish of fly ash constituents through the food chain and subsequent maternal transfer of contaminants to the developing eggs is thought to be the primary route of selenium exposure to larval fish (Woock and others 1987, Coyle and others 1993, Lemly 1999, Moscatello and others 2006), but direct contact of the fertilized eggs and developing embryos to ash constituents in river water and sediments is also a potential risk factor (Woock and others 1987, Coyle and others 1993, Jezierska and others 2009). To address the risk of fly ash from the Kingston spill to the reproductive health of downstream fish populations, ORNL has undertaken a series of studies in collaboration with TVA including: (1) a field study of the bioaccumulation of fly ash constituents in fish ovaries and the reproductive condition of sentinel fish species in reaches of the Emory and Clinch Rivers affected by the fly ash spill; (2) laboratory tests of the potential toxicity of fly ash from the spill area on fish embryonic and larval development (reported in the current

  13. Mutual reinforcement between neuroticism and life experiences: a five-wave, 16-year study to test reciprocal causation.

    PubMed

    Jeronimus, Bertus F; Riese, Harriëtte; Sanderman, Robbert; Ormel, Johan

    2014-10-01

    High neuroticism predicts psychopathology and physical health problems. Nongenetic factors, including major life events and experiences, explain approximately half of the variance in neuroticism. Conversely, neuroticism also predicts these life experiences. In this study, we aimed to quantify the reciprocal causation between neuroticism and life experiences and to gauge the magnitude and persistence of these associations. This longitudinal cohort study included 5 assessment waves over 16 years in a random sample of 296 Dutch participants (47% women) with a mean age of 34 years (SD = 12, range 16-63 years). Neuroticism was assessed with the Amsterdam Biographic Questionnaire. The experiences measured included positive and negative life events, long-term difficulties (LTDs), and change in life quality, all assessed by contextual rating procedures adapted from the Life Event and Difficulties Schedule. We fit structural equation models in Mplus. Results showed that neuroticism consistently predicted negative experiences, decreased life quality, and LTDs (β = 0.15 to 0.39), whereas effects on positive experiences were variable (β = 0.14). LTDs and deteriorated life quality each predicted small but persistent increases in neuroticism (β = 0.18), whereas improved life quality predicted small but persistent decreases (β = -0.13). This suggests set point change in neuroticism. Life event aggregates showed no persistent effects on the neuroticism set point. Neuroticism and life experiences showed persistent, bidirectional associations. Experience-driven changes in neuroticism lasted over a decade. Results support the corresponsive principle (reciprocal causation), suggesting a mixed model of change in neuroticism that distinguishes temporary changes in neuroticism from persistent changes in an individual's neuroticism set point.

  14. [An analysis of the relationship among functional fitness tests, life style and bone density of the elderly in O town, Fukuoka Prefecture].

    PubMed

    Matsuda, S; Tamae, K

    1996-09-01

    A functional fitness test, which is composed of four tests-standing up, walking, hand working, and rope working, was applied to thirty-four elderly women (62.9 +/- 5.2 y.o.) living in O town, Fukuoka Prefecture. The functional fitness level was lower among obese women, and higher among women who were doing more physical activities, as well as those who have more subjects of pleasure in their daily life. Furthermore, there was a positive correlation between the bone density and functional fitness level. The functional fitness test has several favorable characteristics for use in the community based health education for the elderly. For example, 1) it is very easy to conduct and does not require any special pre-test training, 2) it is very safe, 3) as results directly correspond to daily activities, it is rather easy to give concrete advise regarding health promotion in daily life.

  15. Multidimensional Perfectionism, Depression, and Satisfaction with Life: Differences among Perfectionists and Tests of a Stress-Mediation Model

    ERIC Educational Resources Information Center

    Ashby, Jeffrey S.; Noble, Christina L.; Gnilka, Philip B.

    2012-01-01

    This study examined the relationship between adaptive and maladaptive perfectionism, stress, depression, and satisfaction with life in a sample of undergraduate women. The authors found that maladaptive perfectionists had lower satisfaction with life and higher stress and depression scores compared with adaptive perfectionists. Results also…

  16. Use of life tables and LC50 tests to evaluate chronic and acute toxicity effects of copper on the marine copepod Tisbe furcata (Baird)

    SciTech Connect

    Bechmann, R.K. . Dept. of Marine Zoology and Marine Chemistry)

    1994-09-01

    Cohorts of the epiphytic marine copepod Tisbe furcata were chronically exposed to copper in life-table experiments to test whether ecologically relevant impacts can occur at sublethal concentrations. Data on fecundity, longevity, and rate of development were used to calculate r[sub m]--the intrinsic rate of natural increase. Acute toxicity tests were done to compare the concentrations of copper affecting individual lethality and population biology. The LC50 value for Tisbe furcata nauplii was 2.8 [mu]M copper. The results from the life-table experiments show that 0.9 [mu]M copper can cause significant negative effects on demographic parameters (total production of nauplii, life span, and reproductive period for fertile females) and reduce the percentage of fertile females leading to a 61% reduction of r[sub m]. However, r[sub m] was still positive at 0.9 [mu]M copper, and the net reproductive rate (R[sub 0]) indicated a fivefold increase in population size from one generation to the next. Although there were no significant effects of copper at 0.5 [mu]M, there was a negative trend in almost all the demographic parameters, indicating that the observed 10% reduction of r[sub m] at this concentration was an effect of copper. For the substances tested so far with both acute LC50 tests and life-table experiments, r[sub m] was not reduced at concentrations below LC50/10. When life-table experiments are used as part of environmental hazard assessments, concentrations below LC50/10 should be tested to detect substances that are potentially harmful to the environment at sublethal concentrations, rather than testing concentrations close to LC50.

  17. Thermally accelerated life testing of single mode, double-heterostructure, AlGaAs laser diodes operated pulsed at 50 mW peak power

    SciTech Connect

    Barry, J.D.; Archambeault, W.J.; Dye, R.A.; Einhorn, A.J.; Mecherle, G.S.; Nelson, P.

    1985-04-01

    Single spatial mode, double-heterostructure, channel-substrate-planar AlGaAs laser diodes have been life tested under thermally accelerated conditions to characterize the reliability of the diodes in a digital, optical communication system intended for space application. The diodes were operated pulsed under constant drive current conditions at 50 mW peak power, 25 ns pulse width, and 1 percent duty cycle in a dry, inert environment at ambient test temperatures at 40, 55, and 70/sup 0/C. Diode performance parameters as related to the space application, such as pulsewidth, peak power, wavelength spectrum, spatial mode, and threshold current, were periodically monitored. Tests have continued for over 14 000 h. The test results for all diodes with failure defined by power degradation alone is compared to the test results for single mode diodes with failure defined by power degradation, wavelength shift and spatial mode changes. It is found that the life test results are substantially equivalent but differ from earlier published reports for laser diodes operated CW. An activation energy of about 0.39 eV is deduced with a predicted median life of about 5 X 10/sup 4/ h at 20/sup 0/C. These values are somewhat lower than those found for diodes operated CW and are attributed to the use of single mode laser diodes here. It is concluded that thermally accelerated life testing for single spatial mode laser diodes must incorporate a means to separate bulk material, current, and optical density induced degradation effects. A test scheme is proposed.

  18. Rca's Planned Test Program to Compare the Performance and Life of Nicd Cells Containing Pellon 2536 in Contrast with Pellon 2505 Separator Material

    NASA Technical Reports Server (NTRS)

    Schiffer, S. F.

    1985-01-01

    RCA Astro-Electronics will be characterizing and life-testing two groups of hermetically-sealed aerospace nickel-cadmium cells to determine the effect, if any, of a separator change on cell performance. This test, designed to provide information for a specific low-Earth-orbit satellite application, will also add to the overall data-base for cells with the new separator.

  19. A Translation and Validation Study of the Life Orientation Test Revised in the Greek Speaking Population of Nurses among Three Hospitals in Athens and Ioannina

    ERIC Educational Resources Information Center

    Lyrakos, George N.; Damigos, Dimitrios; Mavreas, Venetsanos; Georgia, Kostopanagiotou; Dimoliatis, Ioannis D. K.

    2010-01-01

    The life orientation test-revised (LOT-R) (Scheier et al. in "Journal of Personality and Social Psychology" 67:1063-1078, 1994) is a brief measure for assessing dispositional optimism. The aim of this study was to develop a Greek language version of the LOT-R and to assess the instrument's psychometric properties. The LOT-R was translated and…

  20. 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...

  1. 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...

  2. Testing anti-fungal activity of a soil-like substrate for growing plants in bioregenerative life support systems

    NASA Astrophysics Data System (ADS)

    Nesterenko, E. V.; Kozlov, V. A.; Khizhnyak, S. V.; Manukovsky, N. S.; Kovalev, V. S.; Gurevich, Yu. L.; Liu, Hong; Xing, Yidong; Hu, Enzhu

    2009-10-01

    The object of this research is to study a soil-like substrate (SLS) to grow plants in a Bioregenerative Life Support System (BLSS). Wheat and rice straw were used as raw materials to prepare SLS. Anti-fungal activity of SLS using test cultures of Bipolaris sorokiniana, a plant-pathogenic fungus which causes wheat root rot was studied. Experiments were conducted with SLS samples, using natural soil and sand as controls. Infecting the substrates, was performed at two levels: the first level was done with wheat seeds carrying B. sorokiniana and the second level with seeds and additional conidia of B. sorokiniana from an outside source. We measured wheat disease incidence and severity in two crop plantings. Lowest disease incidence values were obtained from the second planting, SLS: 26% and 41% at the first and the second infection levels, respectively. For soil the values were 60% and 82%, respectively, and for sand they were 67% and 74%, respectively. Wheat root rot in the second crop planting on SLS, at both infection levels was considerably less severe (9% and 13%, respectively) than on natural soil (20% and 33%) and sand (22% and 32%). SLS significantly suppressed the germination of B. sorokiniana conidia. Conidia germination was 5% in aqueous SLS suspension, and 18% in clean water. No significant differences were found regarding the impact on conidia germination between the SLS samples obtained from wheat and rice straw. The anti-fungal activity in SLS increased because of the presence of worms. SLS also contained bacteria stimulating and inhibiting B. sorokiniana growth.

  3. Testing Set-Point Theory in a Swiss National Sample: Reaction and Adaptation to Major Life Events.

    PubMed

    Anusic, Ivana; Yap, Stevie C Y; Lucas, Richard E

    2014-12-01

    Set-point theory posits that individuals react to the experience of major life events, but quickly adapt back to pre-event baseline levels of subjective well-being in the years following the event. A large, nationally representative panel study of Swiss households was used to examine set-point theory by investigating the extent of adaptation following the experience of marriage, childbirth, widowhood, unemployment, and disability. Our results demonstrate that major life events are associated with marked change in life satisfaction and, for some events (e.g., marriage, disability), these changes are relatively long lasting even when accounting for normative, age related change.

  4. 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.

    2015-01-01

    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.

  5. New High Power Test Facility for VHF Power Amplifiers at LANSCE

    SciTech Connect

    Lyles, John T.; Archuletta, Steve; Baca, David M.; Bratton, Ray E.; Brennan, Nicholas W.; Davis, Jerry L.; Lopez, Luis J.; Rees, Daniel E.; Rodriguez, Manuelita B.; Sandoval, Gilbert M. Jr.; Steck, Andy I.; Summers, Richard D.; Vigil, Danny J.

    2011-01-01

    A new test facility was designed and constructed at Los Alamos Neutron Science Center (LANSCE) for testing the Thales TH628 Diacrode{sup R} and TH781 tetrode power amplifiers. Anode power requirements for the TH628 are 28 kV DC, with peak currents of 190 Amperes in long pulses. A charging power supply was obtained by reconfiguring a 2 MW beam power supply remaining from another project. A traditional ignitron crowbar was designed to rapidly discharge the 88 kJ stored energy. The anode power supply was extensively tested using a pulsed tetrode switch and resistor load. A new Fast Protect and Monitor System (FPMS) was designed to take samples of RF reflected power, anode HV, and various tube currents, with outputs to quench the HV charging supply, remove RF drive and disable the conduction bias pulse to the grid of each tube during fault events. The entire test stand is controlled with a programmable logic controller (PLC), for normal startup sequencing and timing, protection against loss of cooling, and provision for operator GUI.

  6. Critical review of Ames Life Science participation in Spacelab Mission Development Test 3: The SMD 3 management study

    NASA Technical Reports Server (NTRS)

    Helmreich, R.; Wilhelm, J.; Tanner, T. A.; Sieber, J. E.; Burgenbauch, S.

    1978-01-01

    A management study was conducted to specify activities and problems encountered during the development of procedures for documentation and crew training on experiments, as well as during the design, integration, and delivery of a life sciences experiment payload to Johnson Space Center for a 7 day simulation of a Spacelab mission. Conclusions and recommendations to project management for current and future Ames' life sciences projects are included. Broader issues relevant to the conduct of future scientific missions under the constraints imposed by the environment of space are also addressed.

  7. Accelerated life test of the USDOE OC-OTEC experimental system refurbished with magnetic bearings for the 3rd stage vacuum compressor. Final report

    SciTech Connect

    Vega, L.A.

    1997-04-01

    This report documents the accelerated life test (time-to-failure) performed, at the request of DOE, to evaluate the viability of the magnetic bearing system installed in the stage 3 vacuum pump. To this effect the plant was successfully operated for over 500 hours during the period September-November 1996. The first part of this report discusses system performance by deriving subsystem and system performance parameters from a typical record. This is followed by the discussion of the life tests. The instrumentation used to estimate the performance parameters given here is depicted. The third stage pump was operated for 535 hours without incident. It is concluded that magnetic bearings are the preferable choice for the OC-OTEC centrifugal vacuum pumps.

  8. Testing for Measurement Invariance in the Satisfaction with Life Scale: A Comparison of Russians and North Americans

    ERIC Educational Resources Information Center

    Tucker, Kari L.; Ozer, Daniel J.; Lyubomirsky, Sonja; Boehm, Julia K.

    2006-01-01

    This study examined the comparability of Satisfaction With Life Scale (SWLS) [Diener, Emmons, Larsen, & Griffin, 1985, "Social Indicators Research," 34: 7-32] scores across U.S. and Russian student and community groups. Criteria for weak measurement invariance were met when comparing U.S. and Russian groups (combining student and community…

  9. Factor Structure, Construct Validity and Reliability of the Seeking of Noetic Goals (SONG) and Purpose in Life (PIL) Tests.

    ERIC Educational Resources Information Center

    Reker, Gary T.; Cousins, J. B.

    1979-01-01

    In this study with 240 introductory psychology students, ten interpretable independent dimensions of satisfaction with life were extracted with six factors that loaded on the PIL and four that loaded on the SONG, supporting Crumbaugh's assertion that the SONG is a complementary scale to the PIL. (Author/SJL)

  10. Influence of test specimen fabrication method and cross-section configuration on tension-tension fatigue life of PMMA bone cement.

    PubMed

    Sheafi, E M; Tanner, K E

    2015-11-01

    Different cyclic loading modes have been used in in vitro fatigue studies of PMMA bone cement. It is unclear which loading mode is most appropriate from the perspective of the in vivo loading experienced by the cement in a cemented arthroplasty. Also, in different in vitro fatigue studies, different test specimen configurations have been used. The present work considers the influence of test specimen fabrication method (direct moulding vs moulding followed by machining) and cross-section shape (rectangular vs circular) on the tension-tension fatigue performance of two bone cement brands (SmartSet GHV and CMW1), under force control conditions. Two trends were consistent: 1) for each of the cements, for moulded specimens, a longer fatigue life was obtained with circular cross-sectioned specimens and, 2) for either rectangular or circular CMW1 specimens, a longer fatigue life was obtained using machined specimens. A comparison of the present results to those reported in our previous work on fully-reversed tension-compression loading under force control showed that, regardless of the test specimen fabrication method or cross-section configuration used, the fatigue life was considerably shorter under tension-compression than tension-tension loading. This finding highlights the fact that the presence of the compression portion in the loading cycle accelerates fatigue failure.

  11. Does adolescent self-esteem predict later life outcomes? A test of the causal role of self-esteem.

    PubMed

    Boden, Joseph M; Fergusson, David M; Horwood, L John

    2008-01-01

    This paper examines the relationship between self-esteem in adolescence and later mental health, substance use, and life and relationship outcomes in adulthood. The investigation analyzed data from a birth cohort of approximately 1,000 New Zealand young adults studied to the age of 25. Lower levels of self-esteem at age 15 were associated with greater risks of mental health problems, substance dependence, and lower levels of life and relationship satisfaction at ages 18, 21, and 25. Adjustment for potentially confounding factors reduced the strength of these associations to either moderate or statistically nonsignificant levels. It was concluded that the effects of self-esteem during adolescence on later developmental outcomes were weak, and largely explained by the psychosocial context within which self-esteem develops. PMID:18211740

  12. Improving the ecological relevance of toxicity tests on scleractinian corals: Influence of season, life stage, and seawater temperature

    USGS Publications Warehouse

    Hedouin, Laetitia; Wolf, Ruth E.; Phillips, Jeff; Gates, Ruth D.

    2016-01-01

    Our data support the paradigm that upward excursions in temperature influence physiological processes in corals that play key roles in regulating metal toxicity. These influences are more pronounced in larva versus adult corals. These findings are important when contextualized climate change-driven warming in the oceans and highlight that predictions of ecological outcomes to metal pollutants will be improved by considering environmental context and the life stages of organism under study.

  13. Surface fatigue life of carburized and hardened M50NiL and AISI 9310 spur gears and rolling-contact test bars

    NASA Technical Reports Server (NTRS)

    Townsend, Dennis P.; Bamberger, Eric N.

    1989-01-01

    Spur gear endurance tests and rolling-element surface tests were conducted to investigate vacuum-induction-melted, vacuum-arc-melted (VIM-VAR) M50NiL steel for use as a gear steel in advanced aircraft applications, to determine its endurance characteristics, and to compare the results with those for standard VAR and VIM-VAR AISI 9310 gear material. Tests were conducted with spur gears and rolling-contact bars manufactured from VIM-VAR M50NiL and VAR and VIM-VAR AISI 9310. The gear pitch diameter was 8.9 cm (3.5 in.). Gear test conditions were an inlet oil temperature of 320 K (116 F), and outlet oil temperature of 350 K (170 F), a maximum Hertz stress of 1.71 GPa (248 ksi), and a speed of 10,000 rpm. Bench rolling-element fatigue tests were conducted at ambient temperatures with a bar speed of 12,500 rpm and a maximum Hertz stress of 4.83 GPA (700 ksi). The VIM-VAR M50NiL gears had a surface fatigue life that was 4.5 and 11.5 times that for VIM-VAR and VAR AISI 9310 gears, respectively. The surface fatigue life of the VIM-VAR M50NiL rolling-contact bars was 13.2 and 21.6 times that for the VIM-VAR and VAR AISI 9310, respectively. The VIM-VAR M50NiL material was shown to have good resistance to fracture through a fatigue spall and to have fatigue life far superior to that of both VIM-VAR and VAR AISI 9310 gears and rolling-contact bars.

  14. Pre-crack fatigue life assessment of relevant aircraft materials using fractal analysis of eddy current test data

    NASA Astrophysics Data System (ADS)

    Schreiber, Jürgen; Cikalova, Ulana; Hillmann, Susanne; Meyendorf, Norbert; Hoffmann, Jochen

    2013-01-01

    Successful determination of residual fatigue life requires a comprehensive understanding of the fatigue related material deformation mechanism. Neither macroscopic continuum mechanics nor micromechanic observations provide sufficient data to explain subsequent deformation structures occurring during the fatigue life of a metallic structure. Instead mesomechanic deformation on different scaling levels can be studied by applying fractal analysis of various means of nondestructive inspection measurements. The resulting fractal dimension data can be correlated to the actual material damage states, providing an estimation of the remaining residual fatigue life before macroscopic fracture develops. Recent efforts were aimed to apply the fractal concept to aerospace relevant materials AA7075-T6 and Ti-6Al-4V. Proven and newly developed fractal analysis methods were applied to eddy current (EC) measurements of fatigued specimens, with the potential to transition this approach to an aircraft for an in-situ nondestructive inspection. The occurrence of mesomechanic deformation at the material surface of both AA7075-T6 and Ti-6Al-4V specimens could be established via topography images using confocal microscopy (CM). Furthermore, a pulsed eddy current (PEC) approach was developed, combined with a sophisticated new fractal analysis algorithm based on short pulse excitation and evaluation of EC relaxation behavior. This paper presents concept, experimental realization, fractal analysis procedures, and results of this effort.

  15. The analytical control program for the NASA Space Station Freedom Environmental Control and Life Support System (ECLSS) Water Recovery Test

    NASA Technical Reports Server (NTRS)

    Tatara, James D.; Minton, Silvia

    1992-01-01

    NASA-Marshall has striven to maximize quality assurance and quality control measures in the course of Water Recovery Test (WRT) development for the Space Station Freedom ECLSS. The WRT was subjected to an independent analytical control program that is governed by the Analytical Control Test Plan and the Microbiological Methods for Water Recovery Testing Plan. Attention is given to analysis results for volatiles, sodium, and conductivity.

  16. Use of various acute, sublethal and early life-stage tests to evaluate the toxicity of refinery effluents

    SciTech Connect

    Sherry, J.; Scott, B.; Dutka, B.

    1997-11-01

    The toxicities of effluents from three Ontario, Canada, refineries were assessed with microbes, plants, invertebrates, and fish. Acute toxicity was assessed by the Microtox test, an assay based on electron transport activity in submitochondrial particles, and Daphnia magna (water flea); growth of Selenastrum capricornutum (alga); growth of Lemna minor (aquatic plant); germination of Lactuca sativa (nonaquatic plant); survival, growth, and maturation of Panagrellus redivivus (nematode); and genotoxicity in the SOS-Chromotest. Only the Microtox test and the submitochondrial particle test detected acute toxicity in the effluent samples. Reduced survival and sublethal responses were caused by some effluents, but not all effluents were toxic, and none caused a response in all of the tests applied. The results suggest that the effluent treatment systems used at Ontario refineries have largely eliminated acute toxicity to the organisms in their test battery. Although reduced survival and sublethal effects were detected in some of the effluents, the effects were minor. Some of the tests provided evidence, albeit weak, of variations in the responses of the test organisms to a temporal series of effluent samples. Not unexpectedly, there were also minor differences in the responses of the tests to effluents from the three refineries. The fathead minnow test seems to be a sensitive indicator of the sublethal toxicity of Ontario refinery effluents.

  17. Predicting Attitudes toward Press- and Speech Freedom across the U.S.A.: A Test of Climato-Economic, Parasite Stress, and Life History Theories

    PubMed Central

    Zhang, Jinguang; Reid, Scott A.; Xu, Jing

    2015-01-01

    National surveys reveal notable individual differences in U.S. citizens’ attitudes toward freedom of expression, including freedom of the press and speech. Recent theoretical developments and empirical findings suggest that ecological factors impact censorship attitudes in addition to individual difference variables (e.g., education, conservatism), but no research has compared the explanatory power of prominent ecological theories. This study tested climato-economic, parasite stress, and life history theories using four measures of attitudes toward censoring the press and offensive speech obtained from two national surveys in the U.S.A. Neither climate demands nor its interaction with state wealth—two key variables for climato-economic theory—predicted any of the four outcome measures. Interstate parasite stress significantly predicted two, with a marginally significant effect on the third, but the effects became non-significant when the analyses were stratified for race (as a control for extrinsic risks). Teenage birth rates (a proxy of human life history) significantly predicted attitudes toward press freedom during wartime, but the effect was the opposite of what life history theory predicted. While none of the three theories provided a fully successful explanation of individual differences in attitudes toward freedom of expression, parasite stress and life history theories do show potentials. Future research should continue examining the impact of these ecological factors on human psychology by further specifying the mechanisms and developing better measures for those theories. PMID:26030736

  18. Predicting Attitudes toward Press- and Speech Freedom across the U.S.A.: A Test of Climato-Economic, Parasite Stress, and Life History Theories.

    PubMed

    Zhang, Jinguang; Reid, Scott A; Xu, Jing

    2015-01-01

    National surveys reveal notable individual differences in U.S. citizens' attitudes toward freedom of expression, including freedom of the press and speech. Recent theoretical developments and empirical findings suggest that ecological factors impact censorship attitudes in addition to individual difference variables (e.g., education, conservatism), but no research has compared the explanatory power of prominent ecological theories. This study tested climato-economic, parasite stress, and life history theories using four measures of attitudes toward censoring the press and offensive speech obtained from two national surveys in the U.S.A. Neither climate demands nor its interaction with state wealth--two key variables for climato-economic theory--predicted any of the four outcome measures. Interstate parasite stress significantly predicted two, with a marginally significant effect on the third, but the effects became non-significant when the analyses were stratified for race (as a control for extrinsic risks). Teenage birth rates (a proxy of human life history) significantly predicted attitudes toward press freedom during wartime, but the effect was the opposite of what life history theory predicted. While none of the three theories provided a fully successful explanation of individual differences in attitudes toward freedom of expression, parasite stress and life history theories do show potentials. Future research should continue examining the impact of these ecological factors on human psychology by further specifying the mechanisms and developing better measures for those theories.

  19. Predicting Attitudes toward Press- and Speech Freedom across the U.S.A.: A Test of Climato-Economic, Parasite Stress, and Life History Theories.

    PubMed

    Zhang, Jinguang; Reid, Scott A; Xu, Jing

    2015-01-01

    National surveys reveal notable individual differences in U.S. citizens' attitudes toward freedom of expression, including freedom of the press and speech. Recent theoretical developments and empirical findings suggest that ecological factors impact censorship attitudes in addition to individual difference variables (e.g., education, conservatism), but no research has compared the explanatory power of prominent ecological theories. This study tested climato-economic, parasite stress, and life history theories using four measures of attitudes toward censoring the press and offensive speech obtained from two national surveys in the U.S.A. Neither climate demands nor its interaction with state wealth--two key variables for climato-economic theory--predicted any of the four outcome measures. Interstate parasite stress significantly predicted two, with a marginally significant effect on the third, but the effects became non-significant when the analyses were stratified for race (as a control for extrinsic risks). Teenage birth rates (a proxy of human life history) significantly predicted attitudes toward press freedom during wartime, but the effect was the opposite of what life history theory predicted. While none of the three theories provided a fully successful explanation of individual differences in attitudes toward freedom of expression, parasite stress and life history theories do show potentials. Future research should continue examining the impact of these ecological factors on human psychology by further specifying the mechanisms and developing better measures for those theories. PMID:26030736

  20. International Space Station Sustaining Engineering: A Ground-Based Test Bed for Evaluating Integrated Environmental Control and Life Support System and Internal Thermal Control System Flight Performance

    NASA Technical Reports Server (NTRS)

    Ray, Charles D.; Perry, Jay L.; Callahan, David M.

    2000-01-01

    As the International Space Station's (ISS) various habitable modules are placed in service on orbit, the need to provide for sustaining engineering becomes increasingly important to ensure the proper function of critical onboard systems. Chief among these are the Environmental Control and Life Support System (ECLSS) and the Internal Thermal Control System (ITCS). Without either, life onboard the ISS would prove difficult or nearly impossible. For this reason, a ground-based ECLSS/ITCS hardware performance simulation capability has been developed at NASA's Marshall Space Flight Center. The ECLSS/ITCS Sustaining Engineering Test Bed will be used to assist the ISS Program in resolving hardware anomalies and performing periodic performance assessments. The ISS flight configuration being simulated by the test bed is described as well as ongoing activities related to its preparation for supporting ISS Mission 5A. Growth options for the test facility are presented whereby the current facility may be upgraded to enhance its capability for supporting future station operation well beyond Mission 5A. Test bed capabilities for demonstrating technology improvements of ECLSS hardware are also described.

  1. Commercial NiMH Cells in LEO Cycling: Thermal Vacuum Life Test Performed for the Floating Potential Probe (FPP)

    NASA Technical Reports Server (NTRS)

    Darcy, Eric; Strangways, Brad

    2003-01-01

    Contents include the following: 1. Introduction: What is the (Floating Potential Probe) FPP? Why was NiMH battery selected? Haw well would crimped seal cell performed in long term vacuum exposure? 2. Verification tests: Battery description. Test methods. Results. Main findings. FPP status.

  2. Slow Crack Growth Analysis of Advanced Structural Ceramics Under Combined Loading Conditions: Damage Assessment in Life Prediction Testing

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Gyekenyesi, John P.

    2000-01-01

    Slow crack growth analysis was performed with three different loading histories including constant stress-rate/constant stress-rate testing (Case I loading), constant stress/constant stress-rate testing (Case II loading), and cyclic stress/constant stress-rate testing (Case III loading). Strength degradation due to slow crack growth arid/or damage accumulation was determined numerically as a Function of percentage of interruption time between the two loading sequences for a given loading history. The numerical solutions were examined with the experimental data determined at elevated temperatures using four different advanced ceramic materials, two silicon nitrides, one silicon carbide and one alumina for the Case I loading history, and alumina for the Case II loading history. The numerical solutions were in reasonable agreement with the experimental data, indicating that notwithstanding some degree of creep deformation presented for some test materials slow crack growth was a governing mechanism associated with failure for all the test material&

  3. Slow Crack Growth Analysis of Advanced Structural Ceramics Under Combined Loading Conditions: Damage Assessment in Life Prediction Testing

    NASA Technical Reports Server (NTRS)

    Choi, Sung R.; Gyekenyesi, John P.

    2000-01-01

    Slow crack growth analysis was performed with three different loading histories including constant stress-rate/constant stress-rate testing (Case 1 loading), constant stress/constant stress-rate testing (Case 2 loading), and cyclic stress/constant stress-rate testing (Case 2 loading). Strength degradation due to slow crack growth and/or damage accumulation was determined numerically as a function of percentage of interruption time between the two loading sequences for a given loading history. The numerical solutions were examined with the experimental data determined at elevated temperatures using four different advanced ceramic materials, two silicon nitrides, one silicon carbide and one alumina for the Case 1 loading history, and alumina for the Case 3 loading history. The numerical solutions were in reasonable agreement with the experimental data, indicating that notwithstanding some degree of creep deformation presented for some test materials slow crack growth was a governing mechanism associated with failure for all the test materials.

  4. 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.

  5. 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

  6. Experimental implementation and proof of principle for a radionuclidic purity test solely based on half-life measurement.

    PubMed

    Jørgensen, Thomas; Jensen, Mikael

    2016-02-01

    In this paper we present the results of an experimental implementation of the method (Jørgensen et al., 2012) for testing the radionuclidic purity (RNP) of F-18 compounds. The overall limitations of the experimental methods and their possible impacts on RNP detectability have been identified. We have developed an GUI application for use as an easy and automated test tool in the production procedure. The test results show that this method fully complies with the requirements in the European Pharmacopoeia (Eur. Ph.) for RNP of FDG and F-18 Sodium Fluoride.

  7. Shelf life determination of sliced Portuguese traditional blood sausage--Morcela de Arroz de Monchique through microbiological challenge and consumer test.

    PubMed

    Pereira, Jorge A; Silva, Pedro; Matos, Teresa J S; Patarata, Luís

    2015-03-01

    Morcela de Arroz (MA) is a ready-to-eat blood and rice cooked sausage produced with pork, blood, rice, and seasonings, stuffed in natural casing and cooked above 90 °C/30 min. It is commercialized whole, not packed, with a restricted shelf life (1 wk/0 to 5 °C). The objective of this work was to establish sliced MA shelf life considering both the behavior of L. monocytogenes through a microbiological challenge test (MCT) and the consumer acceptability of MA stored: vacuum packed (VP), modified atmosphere packed (MAP: 80% CO2/20% N2 ), and aerobic packed (AP). The MCT was conducted inoculating ±3 log CFU/g of L. monocytogenes cell suspension on the MA slices. Packaged samples were stored at 3 ± 1 °C and 7 ± 1 °C until 20 d. At 3 ± 1 °C, L. monocytogenes behavior was not affected by packaging or storage time. At 7 ± 1 °C, the pathogen increased nearly 1 log CFU/g in the first 4 d. L. monocytogenes populations in AP were higher (P < 0.05) than in MAP. The pathogen may grow to hazardous levels in the 1st days if a temperature abuse occurs. Considering the acceptability by the consumers, the shelf life of MA stored at 3 ± 1 °C was 4.4 d for AP, 8.1 d for VP, and 10.4 d for MAP. The sensory shelf life established based on sensory spoilage is shorter than the shelf life to maintain the population of L. monocytogenes in safe levels.

  8. FERTILITY INTENTIONS AND EARLY LIFE HEALTH STRESS AMONG WOMEN IN EIGHT INDIAN CITIES: TESTING THE REPRODUCTIVE ACCELERATION HYPOTHESIS.

    PubMed

    Kulathinal, Sangita; Säävälä, Minna

    2015-09-01

    In life history theory, early life adversity is associated with an accelerated reproductive tempo. In harsh and unpredictable conditions in developing societies fertility is generally higher and the reproductive tempo faster than in more secure environments. This paper examines whether differences in female anthropometry, particularly adult height, are associated with fertility intentions of women in urban environments in India. The study population consists of women aged 15-29 (N=4485) in slums and non-slums of eight Indian cities in the National Family Health Survey (NFHS) of 2005-2006. Adult height is taken as a proxy for early childhood health and nutritional condition. Fertility intentions are examined by using two variables: the desire to have a child or another child, and to have it relatively soon, as indicative of accelerated reproductive scheduling. Evidence supporting the acceleration hypothesis is found in two urban frames out of 26 examined in a two-staged multinomial logistic model. In three cases, the relationship between fertility intentions and height is the opposite than expected by the acceleration hypothesis: taller women have a higher predictive probability of desiring a(nother) child and/or narrower birth spacing. Potential explanations for the partly contradictory relationship between the childhood health indicator and fertility intentions are discussed. PMID:25115228

  9. Apollo-Soyuz test project. Volume 1: Astronomy, earth atmosphere and gravity field, life sciences, and materials processing

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The joint U.S.-USSR experiments and the U.S. conducted unilateral experiments performed during the Apollo Soyuz Test Project are described. Scientific concepts and experiment design and operation are discussed along with scientific results of postflight analysis.

  10. Slow Crack Growth Analysis of Advanced Structural Ceramics Under Combined Loading Conditions: Damage Assessment in Life Prediction Testing

    NASA Technical Reports Server (NTRS)

    Choi, S. R.; Gyekenyesi, J. P.

    2001-01-01

    Slow crack growth analysis was performed with three different loading histories including constant stress- rate/constant stress-rate testing (Case I loading), constant stress/constant stress-rate testing (Case II loading), and cyclic stress/constant stress-rate testing (Case III loading). Strength degradation due to slow crack growth and/or damage accumulation was determined numerically as a function of percentage of interruption time between the two loading sequences for a given loading history. The numerical solutions were examined with the experimental data determined at elevated temperatures using four different advanced ceramic materials, two silicon nitrides, one silicon carbide and one alumina for the Case I loading history, and alumina for the Case II loading history. The numerical solutions were in reasonable agreement with the experimental data, indicating that notwithstanding some degree of creep deformation presented for some test materials slow crack growth was a governing mechanism associated with failure for all the rest materials.

  11. 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

    Potential long-term degradation modes for the two types of modules in the Mead array were determined and judgments were made as to those environmental stresses and combinations of stresses which accelerate the degradation of the power output. Hierarchical trees representing the severity of effects of stresses (test conditions) on eleven individual degradation modes were constructed and were pruned of tests judged to be nonessential. Composites of those trees were developed so that there is now one pruned tree covering eight degradation modes, another covering two degradation modes, and a third covering one degradation mode. These three composite trees form the basis for selection of test conditions in the final test plan which is now being prepared.

  12. 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.

  13. Conceptualising quality of life outcomes for women participating in testing for sexually transmitted infections: A systematic review and meta-synthesis of qualitative research.

    PubMed

    Jackson, Louise J; Roberts, Tracy E

    2015-10-01

    Many public health interventions have aims which are broader than health alone; this means that there are difficulties in using outcome measures that capture health effects only, such as Quality Adjusted Life Years (QALYs). Sexually Transmitted Infections (STIs) are a major public health concern both in the UK and globally, with Chlamydia trachomatis being the most common bacterial STI worldwide. There is scope for the wider use of qualitative syntheses in health-related research; in this study we highlight their potential value in informing outcome identification, particularly for public health interventions where a broad range of outcomes may need to be considered. This article presents a systematic review and meta-ethnography of qualitative studies that investigated women's experiences of thinking about and participating in testing for chlamydia. The meta-ethnography highlights issues relating to beliefs about STIs and testing, assessing risk and interpreting symptoms, emotional responses to testing, coping with diagnosis, relationship with sex partners(s), informal support, and interaction with health care services. The study findings suggest that women can experience a range of impacts on their health and quality of life. It is important that this range of effects is taken into account within evaluations, to ensure that decision makers are fully informed about the outcomes associated with screening interventions, and ultimately, to make sure that appropriate interventions are available to support women in maintaining good sexual health.

  14. The use of multi-species, multi-life stage tests to evaluate soil toxicity at Camp Pendleton Marine Corps Base, California

    SciTech Connect

    Byron, E.; Ohlendorf, H.; Stanaway, M.

    1995-12-31

    Soil toxicity testing was conducted at several contaminated sites as a portion of the ecological risk assessment evaluations at Camp Pendleton Marine Corps Base, California. The primary risk assessment concern at these sites was the potential exposure of site invertebrates, plants, and their secondary consumers (birds, mammals) to toxic levels of contaminants. Contaminants included a variety of organochlorine pesticides, PCBs, herbicides, PAHs, arsenic, heavy metals, and petroleum hydrocarbons. Toxicity to earthworms was measured as survival and growth over 28 days. Toxicity to lettuce was assessed as seed germination and 28-day growth of above-ground plant biomass. Test organisms were exposed to a series of concentrations of site soils diluted with clean control soils ranging from 100% to 25% site soil. The tests yielded varying results which indicated a wide range of sensitivities to toxic contaminants among the test species and life stages. In addition, test results indicated a strong and potentially confounding sensitivity of earthworms to soil structure, apparently independent of soil chemistry. However, the combination of multi-species toxicity tests including the assessment of earthworm and lettuce bioaccumulation of selected contaminants provided a ranking of sites by toxicity, estimates of the probable causes of toxicity, and an assessment of the LC{sup 50} and NOEC values for detected soil contaminants at the Sites.

  15. 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.

  16. Use of Gammarus pulex (L. ) in safety evaluation tests: culture and selection of a sensitive life stage

    SciTech Connect

    McCahon, C.P.; Pascoe, D.

    1988-06-01

    A simple and effective method for the laboratory culture of Gammarus pulex is described. Over 70% of juveniles survived, reaching sexual maturity within 130 days at 13 degrees C, and animals of different ages were available for toxicity tests throughout the year. The acute toxicity of cadmium to cultured animals of several known ages and to field-collected animals of unknown age was determined. Juveniles (1 day old, 48 hr LC50 0.019 mg Cd liter-1) were found to be almost 250 times more sensitive than the oldest age group tested (220 days old, 48 hr LC50 4.7 mg Cd liter-1). In view of its ease of culture and sensitivity to pollutants, it is proposed that G. pulex should be more widely employed as a standard toxicity test species in the hazard evaluation process.

  17. Microbial distribution in the Environmental Control and Life Support System water recovery test conducted at NASA, MSFC

    NASA Technical Reports Server (NTRS)

    Gauthier, J. J.; Roman, M. C.; Kilgore, B. A.; Huff, T. L.; Obenhuber, D. C.; Terrell, D. W.; Wilson, M. E.; Jackson, N. E.

    1991-01-01

    NASA/MSFC is developing a physical/chemical treatment system to reclaim wastewater for reuse on Space Station Freedom (SSF). Integrated testing of hygiene and potable water subsystems assessed the capability to reclaim water to SSF specifications. The test was conducted from May through July 1990 with a total of 47 days of system test operation. Water samples were analyzed using standard cultural methods employing membrane filtration and spread plate techniques and epifluorescence microscopy. Fatty acid methyl ester and biochemical profiles were used for microbial identification. Analysis of waste and product water produced by the subsystems demonstrated the effective reduction of viable microbial populations greater than 8.0E + 06 colony forming units (CFU) per 100 mL to an average of 5 CFU/100 mL prior to distribution into storage tanks.

  18. Design of Refractory Metal Heat Pipe Life Test Environment Chamber, Cooling System, and Radio Frequency Heating System

    NASA Technical Reports Server (NTRS)

    Martin, J. J.; Bragg-Sitton, S. M.; Reid, R. S.; Stewart, E. T.; Davis, J. D.

    2011-01-01

    A series of 16 Mo-44.5%Re alloy/sodium heat pipes will be experimentally tested to examine heat pipe aging. To support this evaluation, an environmental test chamber and a number of auxiliary subsystems are required. These subsystems include radio frequency (RF) power supplies/inductive coils, recirculation water coolant loops, and chamber gas conditioning. The heat pipes will be grouped, based on like power and gas mixture requirements, into three clusters of five units each, configured in a pentagonal arrangement. The highest powered heat pipe will be tested separately. Test chamber atmospheric purity is targeted at <0.3 ppb oxygen at an approximate operating pressure of 76 torr (.1.5 psia), maintained by active purification (oxygen level is comparable to a 10(exp -6) torr environment). Treated water will be used in two independent cooling circuits to remove .85 kW. One circuit will service the RF hardware while the other will maintain the heat pipe calorimetry. Initial procedures for the startup and operation of support systems have been identified. Each of these subsystems is outfitted with a variety of instrumentation, integrated with distributed real-time controllers and computers. A local area network provides communication between all devices. This data and control network continuously monitors the health of the test hardware, providing warning indicators followed by automatic shutdown should potentially damaging conditions develop. During hardware construction, a number of checkout tests.many making use of stainless steel prototype heat pipes that are already fabricated.will be required to verify operation.

  19. An experimental test of the role of environmental temperature variability on ectotherm molecular, physiological and life-history traits: implications for global warming.

    PubMed

    Folguera, Guillermo; Bastías, Daniel A; Caers, Jelle; Rojas, José M; Piulachs, Maria-Dolors; Bellés, Xavier; Bozinovic, Francisco

    2011-07-01

    Global climate change is one of the greatest threats to biodiversity; one of the most important effects is the increase in the mean earth surface temperature. However, another but poorly studied main characteristic of global change appears to be an increase in temperature variability. Most of the current analyses of global change have focused on mean values, paying less attention to the role of the fluctuations of environmental variables. We experimentally tested the effects of environmental temperature variability on characteristics associated to the fitness (body mass balance, growth rate, and survival), metabolic rate (VCO(2)) and molecular traits (heat shock protein expression, Hsp70), in an ectotherm, the terrestrial woodlouse Porcellio laevis. Our general hypotheses are that higher values of thermal amplitude may directly affect life-history traits, increasing metabolic cost and stress responses. At first, results supported our hypotheses showing a diversity of responses among characters to the experimental thermal treatments. We emphasize that knowledge about the cellular and physiological mechanisms by which animals cope with environmental changes is essential to understand the impact of mean climatic change and variability. Also, we consider that the studies that only incorporate only mean temperatures to predict the life-history, ecological and evolutionary impact of global temperature changes present important problems to predict the diversity of responses of the organism. This is because the analysis ignores the complexity and details of the molecular and physiological processes by which animals cope with environmental variability, as well as the life-history and demographic consequences of such variability.

  20. Integration of a Higher Plant Chamber into the European Space Agency's MELiSSA Pilot Plant: The Canadian Role in Advanced Life Support Test-Bed Development

    NASA Astrophysics Data System (ADS)

    Waters, Geoffrey; Lawson, Jamie; Gidzinski, Danuta; Stasiak, Michael; Dixon, Mike; Peiro, Enrique; Godia, Francesc; Paille, Christel; Fossen, Arnaud; Lamaze, Brigitte; Lasseur, Christophe

    The European Space Agency's Micro-Ecological Life Support System Alternative (MELiSSA) project has been conceived as a tool for developing the technology of future biological life support systems required for long-term human space exploration missions to the Moon or Mars. The main life support functions of MELiSSA are the recycling of waste (inedible plant biomass, human excrement), carbon dioxide and minerals and the production of food, fresh water and air revitalization. Based on the principle of an aquatic ecosystem, MELiSSA is comprised of four microbial compartments and a higher plant compartment integrated in a closed loop. Each compartment is studied, designed and demonstrated at laboratory scale before being scaled-up for subsequent integration into the MELISSA Pilot Plant (MPP) at the Universitat Aut`noma de Barcelona. Work related to higher plant cultivation systems, o which have been historically focussed at the University of Guelph's Controlled Environment Systems Research Facility (CESRF), has included design of the HPC for the MPP, the metabolic characterization of MELiSSA candidate crops and the validation of theoretical gas exchange and nutrient dynamic models, The presented paper will review some of the recent data and HPC design work of CESRF conducted as part of Canada's involvement in the MELiSSA program and its partnership in the development of the MPP terrestrial demonstration test-bed.

  1. Maintaining Life-saving Testing for Patients With Infectious Diseases: Infectious Diseases Society of America, American Society for Microbiology, and Pan American Society for Clinical Virology Recommendations on the Regulation of Laboratory-developed Tests.

    PubMed

    Caliendo, Angela M; Couturier, Marc R; Ginocchio, Christine C; Hanson, Kimberly E; Miller, Melissa B; Walker, Kimberly E; Frank, Gregory M

    2016-07-15

    In 2014, the US Food and Drug Administration (FDA) proposed to regulate laboratory-developed tests (LDTs)-diagnostics designed, manufactured, and used within a single laboratory. The Infectious Diseases Society of America, the American Society for Microbiology, and the Pan American Society for Clinical Virology recognize that the FDA is committed to protecting patients. However, our societies are concerned that the proposed regulations will limit access to testing and negatively impact infectious diseases (ID) LDTs. In this joint commentary, our societies discuss why LDTs are critical for ID patient care, hospital infection control, and public health responses. We also highlight how the FDA's proposed regulation of LDTs could impair patient access to life-saving tests and stifle innovation in ID diagnostics. Finally, our societies make specific recommendations for the FDA's consideration to reduce the burden of the proposed new rules on clinical laboratories and protect patients' access to state-of-the art, quality LDTs. PMID:27118790

  2. Maintaining Life-saving Testing for Patients With Infectious Diseases: Infectious Diseases Society of America, American Society for Microbiology, and Pan American Society for Clinical Virology Recommendations on the Regulation of Laboratory-developed Tests.

    PubMed

    Caliendo, Angela M; Couturier, Marc R; Ginocchio, Christine C; Hanson, Kimberly E; Miller, Melissa B; Walker, Kimberly E; Frank, Gregory M

    2016-07-15

    In 2014, the US Food and Drug Administration (FDA) proposed to regulate laboratory-developed tests (LDTs)-diagnostics designed, manufactured, and used within a single laboratory. The Infectious Diseases Society of America, the American Society for Microbiology, and the Pan American Society for Clinical Virology recognize that the FDA is committed to protecting patients. However, our societies are concerned that the proposed regulations will limit access to testing and negatively impact infectious diseases (ID) LDTs. In this joint commentary, our societies discuss why LDTs are critical for ID patient care, hospital infection control, and public health responses. We also highlight how the FDA's proposed regulation of LDTs could impair patient access to life-saving tests and stifle innovation in ID diagnostics. Finally, our societies make specific recommendations for the FDA's consideration to reduce the burden of the proposed new rules on clinical laboratories and protect patients' access to state-of-the art, quality LDTs.

  3. The construction and testing of the EORTC colorectal cancer-specific quality of life questionnaire module (QLQ-CR38). European Organization for Research and Treatment of Cancer Study Group on Quality of Life.

    PubMed

    Sprangers, M A; te Velde, A; Aaronson, N K

    1999-02-01

    The objectives of the current study were to construct a colorectal cancer-specific quality of life (QL) questionnaire module to be used in conjunction with the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 and to test its reliability and validity in The Netherlands. Module construction took place following the EORTC guidelines for module development. The module--the QLQ-CR38--consists of 38 items covering symptoms and side-effects related to different treatment modalities, body image, sexuality and future perspective. This module was tested among 117 colorectal cancer patients on several occasions. The timing was prior to treatment with radiotherapy or chemotherapy, during treatment and 3 months following the second assessment. For purposes of test-retest reliability, a subsample of patients completed the QLQ-CR38 1 week following the third assessment. Multitrait scaling analysis confirmed the hypothesised scale structure of the function scales but not of the symptom scales. Cronbach's alpha coefficients for seven of the nine scales exceeded the 0.70 criterion at one or both assessments. The test-retest reliability for all scales and one single item was 0.78 or higher. The stability of the two remaining single items was lower. On the basis of known-groups comparisons, selective scales distinguished clearly between patients differing in disease stage, initial and on-treatment performance status and the presence of a stoma. Additionally, selective scales detected change over time as a function of change in performance status and treatment-induced change. These results lend support to the clinical validity of the QLQ-CR38 as a supplementary questionnaire for assessing specific QL issues relevant to patients with colorectal cancer. Additional efforts to test the module's cross-cultural validity are needed.

  4. Procedure for developing experimental designs for accelerated tests for service-life prediction. [for solar cell modules

    NASA Technical Reports Server (NTRS)

    Thomas, R. E.; Gaines, G. B.

    1978-01-01

    Recommended design procedures to reduce the complete factorial design by retaining information on anticipated important interaction effects, and by generally giving up information on unconditional main effects are discussed. A hypothetical photovoltaic module used in the test design is presented. Judgments were made of the relative importance of various environmental stresses such as UV radiation, abrasion, chemical attack, temperature, mechanical stress, relative humidity and voltage. Consideration is given to a complete factorial design and its graphical representation, elimination of selected test conditions, examination and improvement of an engineering design, and parametric study. The resulting design consists of a mix of conditional main effects and conditional interactions and represents a compromise between engineering and statistical requirements.

  5. Materials selection for long life in low earth orbit - A critical evaluation of atomic oxygen testing with thermal atom systems

    NASA Technical Reports Server (NTRS)

    Koontz, S. L.; Albyn, K.; Leger, L.

    1990-01-01

    The use of thermal atom test methods as a materials selection and screening technique for low-earth orbit (LEO) spacecraft is critically evaluated. The chemistry and physics of thermal atom environments are compared with the LEO environment. The relative reactivities of a number of materials determined in thermal atom environments are compared with those observed in LEO and in high-quality LEO simulations. Reaction efficiencies (cu cm/atom) measured in a new type of thermal atom apparatus are one-thousandth to one ten-thousandth those observed in LEO, and many materials showing nearly identical reactivities in LEO show relative reactivities differing by as much as a factor of eight in thermal atom systems. A simple phenomenological kinetic model for the reaction of oxygen atoms with organic materials can be used to explain the differences in reactivity in different environments. Certain speciic thermal atom test environments can be used as reliable materials screening tools.

  6. Microbial biofilm studies of the Environmental Control and Life Support System water recovery test for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Obenhuber, D. C.; Huff, T. L.; Rodgers, E. B.

    1991-01-01

    Analysis of biofilm accumulation, studies of iodine disinfection of biofilm, and the potential for microbially influenced corrosion in the water recovery test (WRT) are presented. The analysis of WRT components showed the presence of biofilms and organic deposits in selected tubing. Water samples from the WRT contained sulfate-reducing and acid-producing organisms implicated in corrosion processes. Corrosion of an aluminum alloy was accelerated in the presence of these water samples, but stainless steel corrosion rates were not accelerated.

  7. The Walkback Test: A Study to Evaluate Suit and Life Support System Performance Requirements for a 10 Kilometer Traverse in a Planetary Suit

    NASA Technical Reports Server (NTRS)

    Vos, Jessica R.; Gernhardt, Michael L.; Lee, Lesley

    2007-01-01

    As planetary suit and planetary life support systems develop, specific design inputs for each system relate to a presently unanswered question concerning operational concepts: What distance can be considered a safe walking distance for a suited EVA crew member exploring the surface of the Moon to "walk-back" to the habitat in the event of a rover breakdown, taking into consideration the planned EVA tasks as well as the possible traverse back to the habitat? It has been assumed, based on Apollo program experience, that 10 kilometers (6.2 mi) will be the maximum EVA excursion distance from the lander or habitat to ensure the crew member s safe return to the habitat in the event of a rover failure. To investigate the feasibility of performing a suited 10 km Walkback, NASA-JSC assembled a multi-disciplinary team to design and implement the Lunar Walkback Test . The test was designed not only to determine the feasibility of a 10 km excursion, but also to collect human performance, biomedical, and biomechanical data relevant to optimizing space suit design and life support system sizing. These data will also be used to develop follow-on studies to understand interrelationships of such key parameters as suit mass, inertia, suit pressure, and center of gravity (CG), and the respective influences of each on human performance.

  8. 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.

  9. Overall results of and lessons learned from the IAEA CRP on sodium natural circulation test performed during the Phenix end-of-life experiments

    SciTech Connect

    Monti, S.; Toti, A.; Tenchine, D.; Pialla, D.

    2012-07-01

    In 2007, the International Atomic Energy Agency (IAEA) launched the Coordinated Research Project (CRP) 'Control Rod Withdrawal and Sodium Natural Circulation Tests Performed during the Phenix End-of-Life Experiments'. The overall purpose of the CRP, performed within the framework of the IAEA programme in support of innovative fast reactor technology development and deployment, is to improve the Member States' analytical capabilities in the various fields of research and design of sodium-cooled fast reactors through data and codes verification and validation. In particular the CRP, taking advantage of the End-of-Life set of experiments performed before the final shut-down of the French prototype fast breeder power reactor Phenix, aims at improving fast reactor simulation methods and design capabilities in the field of temperature and power distribution evaluation, as well as of the analysis of sodium natural circulation phenomena. The paper presents the overall results of the CRP, including blind calculations and post-test and sensitivity analyses carried out by the CRP participants, as well as lessons learned and recommendations for further future implementations to resolve open issues. (authors)

  10. Geographic variation of life-history traits in the sand lizard, Lacerta agilis: testing Darwin's fecundity-advantage hypothesis.

    PubMed

    Roitberg, E S; Eplanova, G V; Kotenko, T I; Amat, F; Carretero, M A; Kuranova, V N; Bulakhova, N A; Zinenko, O I; Yakovlev, V A

    2015-03-01

    The fecundity-advantage hypothesis (FAH) explains larger female size relative to male size as a correlated response to fecundity selection. We explored FAH by investigating geographic variation in female reproductive output and its relation to sexual size dimorphism (SSD) in Lacerta agilis, an oviparous lizard occupying a major part of temperate Eurasia. We analysed how sex-specific body size and SSD are associated with two putative indicators of fecundity selection intensity (clutch size and the slope of the clutch size-female size relationship) and with two climatic variables throughout the species range and across two widespread evolutionary lineages. Variation within the lineages provides no support for FAH. In contrast, the divergence between the lineages is in line with FAH: the lineage with consistently female-biased SSD (L. a. agilis) exhibits higher clutch size and steeper fecundity slope than the lineage with an inconsistent and variable SSD (L. a. exigua). L. a. agilis shows lower offspring size (egg mass, hatchling mass) and higher clutch mass relative to female mass than L. a. exigua, that is both possible ways to enhance offspring number are exerted. As the SSD difference is due to male size (smaller males in L. a. agilis), fecundity selection favouring larger females, together with viability selection for smaller size in both sexes, would explain the female-biased SSD and reproductive characteristics of L. a. agilis. The pattern of intraspecific life-history divergence in L. agilis is strikingly similar to that between oviparous and viviparous populations of a related species Zootoca vivipara. Evolutionary implications of this parallelism are discussed.

  11. Biosphere 2 test module: A ground-based sunlight-driven prototype of a closed ecological life support system

    NASA Astrophysics Data System (ADS)

    Nelson, Mark; Leigh, Linda; Alling, Abigail; MacCallum, Taber; Allen, John; Alvarez-Romo, Norberto

    Constructed in 1986, the Biosphere 2 Test Module has been used since the end of that year for closed ecological systems experiments. It is the largest closed ecological facility ever built, with a sealed variable volume of some 480 cubic meters. It is built with a skin of steel spaceframes with double-laminated glass panels admitting about 65 percent Photosynthetically Active Radiation (PAR). The floor is of welded steel and there is an underground atmospheric connection via an air duct to a variable volume chamber (``lung'') permitting expansion and contraction of the Test Module's air volume caused by changes in temperature and barometric pressure, which causes a slight positive pressure from inside the closed system to the outside thereby insuring that the very small leakage rate is outward. Several series of closed ecological system investigations have been carried out in this facility. One series of experiments investigated the dynamics of higher plants and associated soils with the atmosphere under varying light and temperature conditions. Another series of experiments included one human in the closed system for three, five and twenty-one days. During these experiments the Test Module had subsystems which completely recycled its water and atmosphere; all the human dietary needs were produced within the facility, and all wastes were recycled using a marsh plant/microbe system. Other experiments have examined the capability of individual component systems used, such as the soil bed reactors, to eliminate experimentally introduced trace gases. Analytic systems developed for these experiments include continuous monitors of eleven atmospheric gases in addition to the complete gas chromatography mass spectrometry (GCMS) examinations of potable, waste system and irrigation water quality.

  12. Biosphere 2 Test Module: a ground-based sunlight-driven prototype of a closed ecological life support system.

    PubMed

    Nelson, M; Leigh, L; Alling, A; MacCallum, T; Allen, J; Alvarez-Romo, N

    1992-01-01

    Constructed in 1986, the Biosphere 2 Test Module has been used since the end of that year for closed ecological systems experiments. It is the largest closed ecological facility ever built, with a sealed variable volume of some 480 cubic meters. It is built with a skin of steel spaceframes with double-laminated glass panels admitting about 65 percent Photosynthetically Active Radiation (PAR). The floor is of welded steel and there is an underground atmospheric connection via an air duct to a variable volume chamber ("lung") permitting expansion and contraction of the Test Module's air volume caused by changes in temperature and barometric pressure, which causes a slight positive pressure from inside the closed system to the outside thereby insuring that the very small leakage rate is outward. Several series of closed ecological system investigations have been carried out in this facility. One series of experiments investigated the dynamics of higher plants and associated soils with the atmosphere under varying light and temperature conditions. Another series of experiments included one human in the closed system for three, five and twenty-one days. During these experiments the Test Module had subsystems which completely recycled its water and atmosphere; all the human dietary needs were produced within the facility, and all wastes were recycled using a marsh plant/microbe system. Other experiments have examined the capability of individual component systems used, such as the soil bed reactors, to eliminate experimentally introduced trace gases. Analytic systems developed for these experiments include continuous monitors of eleven atmospheric gases in addition to the complete gas chromatography mass spectrometry (GCMS) examinations of potable, waste system and irrigation water quality.

  13. A systems approach to water recovery testing for space life support - Initial biomedical results from the ECLSS Water Recovery Test and plans for testbed utilization

    NASA Technical Reports Server (NTRS)

    Aten, Laurie A.; Crump, William J.; Sauer, Richard L.

    1992-01-01

    Among the challenges of designing and constructing Space Station Freedom is the development of the water system. A review of past efforts in reclaiming waste water in enclosed environments reveals that there are many gaps in the biomedical understanding of this process. Some of the key uncertainties of human interaction with a closed water system include determining potential contaminants and establishing safe levels of multiple compounds in the enclosed system of Space Station. Another uncertainty is the microbial constituency of such a system and what impact it could have on crew health and performance. The use of iodine as the passive biocide may have both an indirect and direct impact on the crew. In this paper the initial results of the Water Recovery Test are reviewed from a biomedical perspective, revealing areas where more information is needed to develop the ECLSS water system. By including the approach of 'man as a subsystem', consideration is given to how man interacts with the total water system. Taking this systems approach to providing the crew with a safe source of water gives useful insight into the most efficient design and utilization of closed system testbeds.

  14. The Impact of Life Role Salience on Life Satisfaction

    ERIC Educational Resources Information Center

    Perrone, Kristin M.; Civiletto, Christine L.

    2004-01-01

    The authors examined the relationships among life role salience, role strain, coping efficacy, and life satisfaction for adults (N = 125) who combine multiple life roles. Causal modeling procedures were used to test hypotheses based on D. E. Super's (1980, 1990) life-span, life-space theory and the social cognitive career theory (R. W. Lent, S. D.…

  15. Materials selection for long life in LEO: A critical evaluation of atomic oxygen testing with thermal atom systems

    NASA Technical Reports Server (NTRS)

    Koontz, S. L.; Kuminecz, J.; Leger, L.; Nordine, P.

    1988-01-01

    The use of thermal atom test methods as a materials selection and screening technique for low-Earth orbit (LEO) spacecraft is critically evaluated. The chemistry and physics of thermal atom environments are compared with the LEO environment. The relative reactivities of a number of materials determined to be in thermal atom environments are compared to those observed in LEO and in high quality LEO simulations. Reaction efficiencies measured in a new type of thermal atom apparatus are one-hundredth to one-thousandth those observed in LEO, and many materials showing nearly identical reactivities in LEO show relative reactivities differing by as much as a factor of 8 in thermal atom systems. A simple phenomenological kinetic model for the reaction of oxygen atoms with organic materials can be used to explain the differences in reactivity in different environments. Certain specific thermal test environments can be used as reliable materials screening tools. Using thermal atom methods to predict material lifetime in LEO requires direct calibration of the method against LEO data or high quality simulation data for each material.

  16. Microbial biofilm studies of the environmental control and life support system water recovery test for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Rodgers, E. B.; Obenhuber, D. C.; Huff, T. L.

    1992-01-01

    NASA is developing a water recovery system (WRS) for Space Station Freedom to reclaim human waste water for reuse by astronauts as hygiene or potable water. A water recovery test (WRT) currently in progress investigates the performance of a prototype of the WRS. Analysis of biofilm accumulation, the potential for microbially influenced corrosion (MIC) in the WRT, and studies of iodine disinfection of biofilm are reported. Analysis of WRT components indicated the presence of organic deposits and biofilms in selected tubing. Water samples for the WRT contained acid-producing and sulfate-reducing organisms implicated in corrosion processes. Corrosion of an aluminum alloy was accelerated in the presence of these water samples; however, stainless steel corrosion rates were not accelerated. Biofilm iodine sensitivity tests using an experimental laboratory scale recycled water system containing a microbial check valve (MCV) demonstrated that an iodine concentration of 1 to 2 mg/L was ineffective in eliminating microbial biofilm. For complete disinfection, an initial concentration of 16 mg/L was required, which was gradually reduced by the MCV over 4 to 8 hours to 1 to 2 mg/L. This treatment may be useful in controlling biofilm formation.

  17. Acute toxicity of 31 different nanoparticles to zebrafish (Danio rerio) tested in adulthood and in early life stages – comparative study

    PubMed Central

    Kovrižnych, Jevgenij A.; Zeljenková, Dagmar; Rollerová, Eva; Szabová, Elena; Wimmerová, Soňa

    2013-01-01

    At present, nanoparticles are beginning to influence our lives in many ways and understanding the environmental health and safety aspect of nanomaterials has become a crucial issue. The aim of the work was to assess and compare the acute toxicity of 31 different nanomaterials to fish mature individuals Danio rerio with that to fish early life stages on using evaluation of the 48- and 96- hour LC50 values. A further aim was to evaluate teratogenicity of the nanoparticles tested to fish eggs. The nanoparticles tested were: 8 pure metals, 10 metal oxides, 5 other metal compounds and their mixtures, 2 silicon compounds, 3 calcium compounds, and 3 carbon compounds. Using 48-h and 96-h tests of acute toxicity (according to OECD 203), we evaluated mortality data, LC50 values, occurrence of malformations, as well as hatching time. In our study, 6 kinds of nanoparticles – calcium oxide, copper, copper in the form of oxide and CuZnFe4O4, magnesium oxide, and nickel – caused cumulative mortality. Two kinds of nanoparticles – copper and silver – were toxic for fish with LC50 values of approximately 3 mg/L. We did not observe marked differences between the 48-hour and 96-hour acute toxicity LC50 values, yet the possibility to evaluate hatching time in the 96-h acute fish toxicity test seems to be an advantage against that of the 48-hour toxicity. PMID:24179431

  18. Analysis of the Phenix end-of-life natural convection test with SAS4A/SASSYS-1

    SciTech Connect

    Thomas, J. W.; Fanning, T. H.; Dunn, F. E.; Sofu, T.

    2012-07-01

    From a reduced power and flow condition, the 2009 Phenix Natural Convection Test mimics a protected loss-of-heat sink event. The measured transient response of the Phenix reactor to such an event provides an important data set for validating safety analysis codes. A model of the Phenix reactor and primary coolant system was developed using the reactor safety analysis code system SAS4A/SASSYS-1. While the overall global response of the reactor was predicted reasonably well, there were some non-negligible discrepancies in the temperature predictions during the transient and work continues to improve the model. Some modeling issues have been identified, and will be addressed as improvements to the model continue. (authors)

  19. Cycle life testing and modeling of graphite/LiCoO2 cells under different state of charge ranges

    NASA Astrophysics Data System (ADS)

    Saxena, Saurabh; Hendricks, Christopher; Pecht, Michael

    2016-09-01

    Lithium-ion batteries are used for energy storage in a wide array of applications, and do not always undergo full charge and discharge cycling. This study quantifies the effect of partial charge-discharge cycling on Li-ion battery capacity loss by means of cycling tests conducted on graphite/LiCoO2 pouch cells under different state of charge (SOC) ranges and discharge currents. The results are used to develop a model of capacity fade for batteries under full or partial cycling conditions. This study demonstrates that all of the variables studied including mean SOC, change in SOC (ΔSOC) and discharge rate have a significant impact on capacity loss rate during the cycling operation. This study is useful in identifying the SOC ranges with slow degradation rates.

  20. Life strain, negative emotions, and delinquency: An empirical test of general strain theory in the People's Republic of China.

    PubMed

    Bao, Wan-Ning; Haas, Ain; Pi, Yijun

    2004-06-01

    Using a sample of 615 middle school and high school students from both rural and urban areas of the People's Republic of China, this study tests the central hypotheses concerning the mediating model in Agnew's general strain theory. The analyses focus on the intervening mechanisms of negative emotions such as anger, resentment, anxiety, and depression that connect exposure to interpersonal strain with delinquent outcomes, including both serious delinquency and minor offenses. The results show that anger mediates the effect of interpersonal strain on violence, resentment mediates the effect of interpersonal strain on nonviolent delinquency, and anxiety and depression have a mediating effect on the relationships between interpersonal strain and minor offenses. The findings are generally consistent with the results of earlier studies in the United States.

  1. 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.

  2. Effects of Activated Carbon on PCB Bioaccumulation and Biological Responses of Chironomus riparius in Full Life Cycle Test.

    PubMed

    Nybom, Inna; Abel, Sebastian; Waissi, Greta; Väänänen, Kristiina; Mäenpää, Kimmo; Leppänen, Matti T; Kukkonen, Jussi V K; Akkanen, Jarkko

    2016-05-17

    The nonbiting midge Chironomus riparius was used to study the remediation potential and secondary effects of activated carbon (AC, ø 63-200 μm) in PCB contaminated sediments. AC amendments efficiently reduced PCB bioavailability determined by Chironomus riparius bioaccumulation tests and passive samplers. PCBs were shown to transfer from larvae to adults. Lower PCB concentrations were observed in adult midges emerging from AC amended compared to unamended sediments. Increased reproduction, survival, larval growth and gut wall microvilli length were observed with low AC dose (0.5% sediment dw) compared to unamended sediment, indicating an improved success of larvae in the sediment with low organic carbon content. On the other hand, higher AC doses (2.5% sediment dw) caused adverse effects on emergence and larval development. In addition, morphological changes in the gut wall microvilli layer were observed. This study showed that the secondary effects of AC amendments are dependent on the dose and the sediment characteristics. Metamorphic species, such as C. riparius, may act as a vector for organic pollutants from aquatic to terrestrial ecosystems and according to this study the AC amendments may reduce this transport. PMID:27100921

  3. Development and Testing of a Life Cycle Model and a Parameterization of Thin Mid-level Stratiform Clouds

    SciTech Connect

    Krueger, Steven K.

    2008-03-03

    We used a cloud-resolving model (a detailed computer model of cloud systems) to evaluate and improve the representation of clouds in global atmospheric models used for numerical weather prediction and climate modeling. We also used observations of the atmospheric state, including clouds, made at DOE's Atmospheric Radiation Measurement (ARM) Program's Climate Research Facility located in the Southern Great Plains (Kansas and Oklahoma) during Intensive Observation Periods to evaluate our detailed computer model as well as a single-column version of a global atmospheric model used for numerical weather prediction (the Global Forecast System of the NOAA National Centers for Environmental Prediction). This so-called Single-Column Modeling approach has proved to be a very effective method for testing the representation of clouds in global atmospheric models. The method relies on detailed observations of the atmospheric state, including clouds, in an atmospheric column comparable in size to a grid column used in a global atmospheric model. The required observations are made by a combination of in situ and remote sensing instruments. One of the greatest problems facing mankind at the present is climate change. Part of the problem is our limited ability to predict the regional patterns of climate change. In order to increase this ability, uncertainties in climate models must be reduced. One of the greatest of these uncertainties is the representation of clouds and cloud processes. This project, and ARM taken as a whole, has helped to improve the representation of clouds in global atmospheric models.

  4. Distribution, life history, management, and current status of Astragalus beatleyae on the US Department of Energy's Nevada Test Site

    SciTech Connect

    Blomquist, K.W.; Wills, C.A.; Ostler, W.K.; Rautenstrauch, K.R.; O'Farrell, T.P.

    1992-11-01

    A beatleyae is a small milk vetch found in south-central Nevada on portions of the Nevada Test Site (NTS) and Nellis Air Force Range. This species has been classified as a Category 1 candidate species for federal listing under the Endangered Species Act because of its limited range and threats from human activities, primarily activities conducted by the US Department of Energy, Nevada Field Office (DOE/NV). The status of A. beatleyae was last evaluated over 13 years ago (Rhoads et al., 1979, Beatley, 1978). Since then, numerous conservation measures have been taken by DOE/NV and additional information on the status of this population has been obtained. Field surveys have been conducted to locate new populations of A. beatleyae. Because of this work, the known range of this species has been expanded approximately 300%. DOE/NV has established. a conservation agreement with the US Fish and Wildlife Service and developed a Species Management Plan. This report is a presentation of the results of that population monitoring study. Also included in this report are a review of other field investigations and conservation measures taken by DOE/NV, a review of the current threats to A. beatleyae, and a reassessment of the status of this species under the Endangered Species Act.

  5. Population consequences of fipronil and degradates to copepods at field concentrations: an integration of life cycle testing with leslie matrix population modeling.

    PubMed

    Chandler, G Thomas; Cary, Tawnya L; Bejarano, Adriana C; Pender, Jack; Ferry, John L

    2004-12-01

    The predominant data used in ecological risk assessment today are individual-based rather than population-based; yet environmental policies are usually designed to protect populations of threatened species or communities. Most current methods in ecotoxicology are limited by largely logistic/ technology-driven requirements that yield data for a relatively small number of test species and end points that focus on acute lethality or sublethal nonproduction-based parameters (e.g., biomarkers, mutagenesis, genetic change, physiological condition). A contrasting example is presented here showing the predictive ability of meiobenthos-based full life cycle toxicity testing to extrapolate multi-generational effects of chemicals on variables of import to population growth and maintenance. Less than 24-h-old larvae of a meiobenthic copepod were reared individually in 96-well microplate exposures to parent and degradates of the phenylpyrazole insecticide fipronil. Survival, development rates, sex ratio change, fertility, fecundity, and hatching success were tracked daily for 32 d through mating and production of three broods in spiked seawater. These data were then inserted in a Leslie (Lefkovitch) matrix stage-based population growth model to predict relative rates of population increase (lambda) and changes in net population growth with time and toxicant concentration. Field-reported test concentrations produced strong reproductive (52-88%) and net production (40-80%) depressions for parent (at 0.25 and 0.5 microg/L), desthionyl (0.25 and 0.5 microg/L), and sulfide (0.15 microg/L) moieties as compared to controls. Spiked sediment exposures of 65-300 ng of fipronil/g of dry sediment yielded significantly reduced production rates per female that were 67-50% of control production. The consistent reproductively linked impacts of fipronil and its degradation products at the population maintenance levels suggest risks to sediment-dwelling crustaceans at concentrations well below

  6. 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.

  7. 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. PMID:14696586

  8. Indentation hardness: A simple test that correlates with the dissipated-energy predictor for fatigue-life in bovine pericardium membranes for bioprosthetic heart valves.

    PubMed

    Tobaruela, Almudena; Rojo, Francisco Javier; García Paez, José María; Bourges, Jean Yves; Herrero, Eduardo Jorge; Millán, Isabel; Alvarez, Lourdes; Cordon, Ángeles; Guinea, Gustavo V

    2016-08-01

    The aim of this study was to evaluate the variation of hardness with fatigue in calf pericardium, a biomaterial commonly used in bioprosthetic heart valves, and its relationship with the energy dissipated during the first fatigue cycle that has been shown to be a predictor of fatigue-life (García Páez et al., 2006, 2007; Rojo et al., 2010). Fatigue tests were performed in vitro on 24 pericardium specimens cut in a root-to-apex direction. The specimens were subjected to a maximum stress of 1MPa in blocks of 10, 25, 50, 100, 250, 500, 1000 and 1500 cycles. By means of a modified Shore A hardness test procedure, the hardness of the specimen was measured before and after fatigue tests. Results showed a significant correlation of such hardness with fatigue performance and with the energy dissipated in the first cycle of fatigue, a predictor of pericardium durability. The study showed indentation hardness as a simple and reliable indicator of mechanical performance, one which could be easily implemented in improving tissue selection.

  9. Test-Retest Reliability and Validity of Life-Course Alcohol Consumption Measures: The 2005 National Alcohol Survey Follow Up

    PubMed Central

    Greenfield, Thomas K.; Nayak, Madhabika B.; Bond, Jason; Kerr, William C.; Ye, Yu

    2014-01-01

    Background Few studies assess reliability and validity of lifetime alcohol measures. We undertook extended test-retest analyses of retrospective lifetime drinking measures and of incremental predictive ability of lifetime heavy drinking (days 5+ drinks) in teens, 20s and 30s for current (12-month) alcohol use disorders. Methods A subset (31.4%; 962 men, 1220 women) of the 2005 US National Alcohol Survey (NAS; N11) completed a follow-up survey (N11T) by phone or mail (mean delay of 2.7 years). Both surveys assessed lifetime drinking. Results In N11T, drinking status was reported consistently by 94.7% of N11 current drinkers, 85.5% of ex-drinkers and 74.4% of lifetime abstainers (93.5% overall). Cumulative number of prior heavy drinking days (teens through 30s) were moderately consistent (Pearson's ρ=0.6, p<0.001, n=1,636). Reliability was lower for younger respondents under 30 and higher for Whites versus Blacks and Hispanics (ρ=0.68 vs. ρ=0.56 vs. ρ=0.56, both p=0.01), but did not differ by gender. Heavy drinking days in teens correlated 0.63 (p < 0.001) for those aged 20 or older, higher for women than men and for Whites versus ethnic minorities. Heavy drinking days in the twenties and thirties reported by those 30 and older and 40 and older correlated at 0.63 and 0.67, respectively, being higher for Whites. Age of drinking onset and of lifetime maximum quantity reports were also consistent (0.65, 0.73), higher for women versus men, for those older than 29 versus younger, and for Whites versus Blacks and Hispanics. In N11, controlling for gender, age, ethnicity and current 5+ frequency, cumulative prior 5+ days (teens to age 39) predicted current alcohol-related consequences and dependence (both p=0.003). Conclusions Measurements of earlier heavy drinking is feasible, efficient, and reasonably reliable, albeit with some individual imprecision. Prior drinking data improve prediction of current alcohol use disorders, adjusting for demographics and current

  10. A Double-Blind, Rct Testing Beneficial Modulation of Bdnf in Middle-Aged, Life Style-Stressed Subjects: A Clue to Brain Protection?

    PubMed Central

    Marcellino, M; Marotta, F; Sweed, H; Solimene, U; Vignali, AI; Xiao, W; Ayala, A; Cagnuolo, U; Zerbinati, N

    2014-01-01

    Introduction: The aim of this prospective study was to see whether LD-1227, a quality-controlled marine nutraceuticals shown to protect experimental stress-induced hyppocampal degeneration, could beneficially modulate BDNF, as measured in the serum, in otherwise healthy but work-stressed individuals. Materials and Methods: Forty-eight men and women between the ages of 38 and 62 reporting high-demanding work activity but with an overall positive attitude towards their personal life were recruited. Subjects were divided in two group (24 patients each) and blindly supplemented for 2 month with: a) LD-1227 400mg or b) placebo. A third group of healthy non-stressed subjects was used as well. Blood samples were taken before and after the supplementation period. Unstimulated saliva was collected and tested for amylase while serum levels were used to measure BDNF. State Trait Anxiety Inventory (STAI), Pittsburgh Sleep Quality Index (PSQI) and psychological well-being assessment (PSWB) were measured too. Patients with Val66Met functional polymorphism of BDNF excluded those given their reported association with an impaired release of BDNF. Results: Results showed that, as compared to healthy, non-stressed individuals, stressed ones has a trend decrease of BDNF and this was significantly increased by LD 12-1227 supplementation and the same inverse phenomenon occurred to salivary amylase (p<0.05). No change was noted in the PSQI score but, either STAI or PSWB tests scored better in LD-1227 supplemented subjects. Conclusion: The present data suggest that LD-1227 is beneficially affecting neuromodulation and related symptoms during common stressful life conditions and may have the potential as tools in a neuroprotective clinical strategy. PMID:25584253

  11. Preparing for life in space.

    PubMed

    Dasch, P

    1997-01-01

    The third team to inhabit the Advanced Life Support Test Chamber at the Johnson Space Center participated in an interview about life in the test chamber and program goals. Questions examine the air and water systems; human factors such as life in confinement, privacy, health, and training; and exercise. The test chamber is used to test life support systems for the International Space Station, lunar bases, and manned missions to Mars.

  12. Flipping the advanced cardiac life support classroom with team-based learning: comparison of cognitive testing performance for medical students at the University of California, Irvine, United State

    PubMed Central

    2016-01-01

    Purpose: It aimed to find if written test results improved for advanced cardiac life support (ACLS) taught in flipped classroom/team-based Learning (FC/TBL) vs. lecture-based (LB) control in University of California-Irvine School of Medicine, USA. Methods: Medical students took 2010 ACLS with FC/TBL (2015), compared to 3 classes in LB (2012-14) format. There were 27.5 hours of instruction for FC/TBL model (TBL 10.5, podcasts 9, small-group simulation 8 hours), and 20 (12 lecture, simulation 8 hours) in LB. TBL covered 13 cardiac cases; LB had none. Seven simulation cases and didactic content were the same by lecture (2012-14) or podcast (2015) as was testing: 50 multiple-choice questions (MCQ), 20 rhythm matchings, and 7 fill-in clinical cases. Results: 354 students took the course (259 [73.1%] in LB in 2012-14, and 95 [26.9%] in FC/TBL in 2015). Two of 3 tests (MCQ and fill-in) improved for FC/TBL. Overall, median scores increased from 93.5% (IQR 90.6, 95.4) to 95.1% (92.8, 96.7, P=0.0001). For the fill-in test: 94.1% for LB (89.6, 97.2) to 96.6% for FC/TBL (92.4, 99.20 P=0.0001). For MC: 88% for LB (84, 92) to 90% for FC/TBL (86, 94, P=0.0002). For the rhythm test: median 100% for both formats. More students failed 1 of 3 tests with LB vs. FC/TBL (24.7% vs. 14.7%), and 2 or 3 components (8.1% vs. 3.2%, P=0.006). Conversely, 82.1% passed all 3 with FC/TBL vs. 67.2% with LB (difference 14.9%, 95% CI 4.8-24.0%). Conclusion: A FC/TBL format for ACLS marginally improved written test results. PMID:26893399

  13. Effects of carbamazepine and two of its metabolites on the non-biting midge Chironomus riparius in a sediment full life cycle toxicity test.

    PubMed

    Heye, Katharina; Becker, Dennis; Lütke Eversloh, Christian; Durmaz, Vedat; Ternes, Thomas A; Oetken, Matthias; Oehlmann, Jörg

    2016-07-01

    The antiepileptic drug carbamazepine (CBZ) and its main metabolites carbamazepine-10,11-epoxide (EP-CBZ) and 10,11-dihydro-10,11-dihydroxy-carbamazepine (DiOH-CBZ) were chosen as test substances to assess chronic toxicity on the non-biting midge Chironomus riparius. All the three substances were tested in a 40-day sediment full life cycle test (according to OECD 233) in which mortality, emergence, fertility, and clutch size were evaluated. In addition, these parameters were considered to calculate the population growth rate which represents an integrated measure to assess population relevant effects. With an LC50 of 0.20 mg/kg (time-weighted mean), the metabolite EP-CBZ was significantly more toxic than the parent substance CBZ (LC50: 1.1 mg/kg). Especially mortality, emergence, and fertility showed to be sensitive parameters under the exposure to CBZ and EP-CBZ. By using classical molecular dynamics (MD) simulations, the binding of CBZ to the ecdysone receptor was investigated as one possible mode of action (MoA) but appeared to be unlikely. The second metabolite DiOH-CBZ did not cause any effects within the tested concentration rage (0.17-1.2 mg/kg). Even though CBZ was less toxic compared to EP-CBZ, CBZ is found in the environment at much higher concentrations and therefore causes a higher potential risk for sediment dwelling organisms compared to its metabolites. Nevertheless, the current study illustrates the importance of including commonly found metabolites into the risk assessment of parent substances. PMID:27064208

  14. Testing the role of ecology and life history in structuring genetic variation across a landscape: a trait-based phylogeographic approach.

    PubMed

    Paz, Andrea; Ibáñez, Roberto; Lips, Karen R; Crawford, Andrew J

    2015-07-01

    Hypotheses to explain phylogeographic structure traditionally invoke geographic features, but often fail to provide a general explanation for spatial patterns of genetic variation. Organisms' intrinsic characteristics might play more important roles than landscape features in determining phylogeographic structure. We developed a novel comparative approach to explore the role of ecological and life-history variables in determining spatial genetic variation and tested it on frog communities in Panama. We quantified spatial genetic variation within 31 anuran species based on mitochondrial DNA sequences, for which hierarchical approximate Bayesian computation analyses rejected simultaneous divergence over a common landscape. Regressing ecological variables, on genetic divergence allowed us to test the importance of individual variables revealing that body size, current landscape resistance, geographic range, biogeographic origin and reproductive mode were significant predictors of spatial genetic variation. Our results support the idea that phylogeographic structure represents the outcome of an interaction between organisms and their environment, and suggest a conceptual integration we refer to as trait-based phylogeography.

  15. Testing the role of ecology and life history in structuring genetic variation across a landscape: a trait-based phylogeographic approach.

    PubMed

    Paz, Andrea; Ibáñez, Roberto; Lips, Karen R; Crawford, Andrew J

    2015-07-01

    Hypotheses to explain phylogeographic structure traditionally invoke geographic features, but often fail to provide a general explanation for spatial patterns of genetic variation. Organisms' intrinsic characteristics might play more important roles than landscape features in determining phylogeographic structure. We developed a novel comparative approach to explore the role of ecological and life-history variables in determining spatial genetic variation and tested it on frog communities in Panama. We quantified spatial genetic variation within 31 anuran species based on mitochondrial DNA sequences, for which hierarchical approximate Bayesian computation analyses rejected simultaneous divergence over a common landscape. Regressing ecological variables, on genetic divergence allowed us to test the importance of individual variables revealing that body size, current landscape resistance, geographic range, biogeographic origin and reproductive mode were significant predictors of spatial genetic variation. Our results support the idea that phylogeographic structure represents the outcome of an interaction between organisms and their environment, and suggest a conceptual integration we refer to as trait-based phylogeography. PMID:26080899

  16. Thermal vacuum real-life test of an Marconi Space and Defence Systems (MSDS) solar-array drive mechanism (MSDS 002). First four years of operation

    NASA Astrophysics Data System (ADS)

    Parker, K.; Douglas, A.; Burke, W. R.

    1981-01-01

    The first part of a 7 yr life test on a mechanism which turns a satellite solar array at 1rev/day is reported. A thermal transfer shroud, surrounding the mechanism in a vacuum chamber, is held at a constant temperature of 22.5 C while the shaft temperature, measured near the top of the shaft at the large bearing, is changed at 6-monthly intervals so that it operates alternately at 60 and 10 C. At the beginning of each 6-monthly cycle, 30 eclipse simulations are performed, i.e., the shaft temperature is reduced from 60 C to 0 C in 72 min and is returned to 60 C in as short a time as possible. Apart from a very small increase in motor power during eclipse simulation, no changes in the mechanism parameters occur with temperature. The mechanism operates within motor power and angular rotation accuracy specifications. The electrical noise on all slip rings increased during the first two years, but then slowly decreased. Certain slip ring pairs show a noise level in excess of the arbitrary limits set at the start of the test, and two slip ring pairs give large periodic noise transients which may be due to mechanical damage to the slip rings or brushes.

  17. Effects of Ag nanomaterials (NM300K) and Ag salt (AgNO3) can be discriminated in a full life cycle long term test with Enchytraeus crypticus.

    PubMed

    Bicho, Rita C; Ribeiro, Tânia; Rodrigues, Natália P; Scott-Fordsmand, Janeck J; Amorim, Mónica J B

    2016-11-15

    Information on effects of silver nanoparticles on soil invertebrates, especially using long-term exposures, is scarce. In this study we investigated the effects of the reference Ag (NM300K) (compared to AgNO3) using the full life cycle test (FLCt) of the soil invertebrate Enchytraeus crypticus. Results showed that effects were higher compared to the standard reproduction test, which is shorter and does not cover the FLC. Both Ag forms caused a reduction on hatching success, juvenile and adult survival and reproduction with similar ECx. Differences between AgNO3 and Ag NM300K could be discriminated using the FLCt: AgNO3 decreased hatching success was shown to be a delay in the process, whereas Ag NM300K caused irreversible effects during the same time frame. These effects may have occurred during the embryo development, hatching (inhibition) or survival of hatched juveniles. Ag NM300K caused non-monotonic concentration-response effect as observed by the high effect of the lowest concentration (20mgkg-1). It is known that dispersion is higher at lower concentrations - this could explain the increased effect at low concentration. Non monotonic responses are well described in the literature, where effects of high cannot predict for low concentrations, hence special attention should be given for NMs low concentration effects. PMID:27474850

  18. Microbiological Tests Performed During the Design of the International Space Station Environmental Control and Life Support Systems. Part 1, Bulk Phase. Part 1; Bulk Phase

    NASA Technical Reports Server (NTRS)

    Roman, Monsi C.; Mittelman, Marc W.

    2010-01-01

    The design and manufacturing of the main Environmental Control and Life Support Systems (ECLSS) for the United States segments of the International Space Station (ISS) was an involved process that started in the mid 1980s, with the assessment and testing of competing technologies that could be used to clean the air and recycle water. It culminated in 2009 with the delivery and successful activation of the Water Recovery System (WRS) water processor (WP). The ECLSS required the work of a team of engineers and scientist working together to develop systems that could clean and/or recycle human metabolic loads to maintain a clean atmosphere and provide the crew clean water. One of the main goals of the ECLSS is to minimize the time spent by the crew worrying about vital resources not available in the vacuum of space, which allows them to spend most of their time learning to live in a microgravity environment many miles from the comforts of Earth and working on science experiments. Microorganisms are a significant part of the human body as well as part of the environment that we live in. Therefore, the ISS ECLSS design had to take into account the effect microorganisms have on the quality of stored water and wastewater, as well as that of the air systems. Hardware performance issues impacted by the accumulation of biofilm and/or microbiologically influenced corrosion were also studied during the ECLSS development stages. Many of the tests that were performed had to take into account the unique aspects of a microgravity environment as well as the challenge of understanding how to design systems that could not be sterilized or maintained in a sterile state. This paper will summarize the work of several studies that were performed to assess the impacts and/or to minimize the effects of microorganisms in open, semi-closed and closed loop life support system. The biofilm and biodeterioration studies that were performed during the design and test periods will be presented in

  19. Life's Still Lifes

    NASA Astrophysics Data System (ADS)

    McIntosh, Harold V.

    The de Bruijn diagram describing those decompositions of the neighborhoods of a one dimensional cellular automaton which conform to predetermined requirements of periodicity and translational symmetry shows how to construct extended configurations satisfying the same requirements. Similar diagrams, formed by stages, describe higher dimensional automata, although they become more laborious to compute with increasing neighborhood size. The procedure is illustrated by computing some still lifes for Conway's game of Life, a widely known two dimensional cellular automaton. This paper is written in September 10, 1988.

  20. Evaluation of measurement equivalence of the Family Satisfaction with the End-of-Life Care in an ethnically diverse cohort: Tests of differential item functioning

    PubMed Central

    Teresi, Jeanne A; Ocepek-Welikson, Katja; Ramirez, Mildred; Kleinman, Marjorie; Ornstein, Katherine; Siu, Albert

    2016-01-01

    Background The Family Satisfaction with End-of-Life Care is an internationally used measure of satisfaction with cancer care. However, the Family Satisfaction with End-of-Life Care has not been studied for equivalence of item endorsement across different socio-demographic groups using differential item functioning. Aims The aims of this secondary data analysis were (1) to examine potential differential item functioning in the family satisfaction item set with respect to type of caregiver, race, and patient age, gender, and education and (2) to provide parameters and documentation of differential item functioning for an item bank. Design A mixed qualitative and quantitative analysis was conducted. A priori hypotheses regarding potential group differences in item response were established. Item response theory and Wald tests were used for the analyses of differential item functioning, accompanied by magnitude and impact measures. Results Very little significant differential item functioning was observed for patient's age and gender. For race, 13 items showed differential item functioning after multiple comparison adjustment, 10 with non-uniform differential item functioning. No items evidenced differential item functioning of high magnitude, and the impact was negligible. For education, 5 items evidenced uniform differential item functioning after adjustment, none of high magnitude. Differential item functioning impact was trivial. One item evidenced differential item functioning for the caregiver relationship variable. Conclusion Differential item functioning was observed primarily for race and education. No differential item functioning of high magnitude was observed for any item, and the overall impact of differential item functioning was negligible. One item, satisfaction with “the patient's pain relief,” might be singled out for further study, given that this item was both hypothesized and observed to show differential item functioning for race and education