Sample records for controlled test atmospheres

  1. 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.

  2. 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.

  3. Robust control algorithms for Mars aerobraking

    NASA Technical Reports Server (NTRS)

    Shipley, Buford W., Jr.; Ward, Donald T.

    1992-01-01

    Four atmospheric guidance concepts have been adapted to control an interplanetary vehicle aerobraking in the Martian atmosphere. The first two offer improvements to the Analytic Predictor Corrector (APC) to increase its robustness to density variations. The second two are variations of a new Liapunov tracking exit phase algorithm, developed to guide the vehicle along a reference trajectory. These four new controllers are tested using a six degree of freedom computer simulation to evaluate their robustness. MARSGRAM is used to develop realistic atmospheres for the study. When square wave density pulses perturb the atmosphere all four controllers are successful. The algorithms are tested against atmospheres where the inbound and outbound density functions are different. Square wave density pulses are again used, but only for the outbound leg of the trajectory. Additionally, sine waves are used to perturb the density function. The new algorithms are found to be more robust than any previously tested and a Liapunov controller is selected as the most robust control algorithm overall examined.

  4. Design development and test: Two-gas atmosphere control subsystem

    NASA Technical Reports Server (NTRS)

    Jackson, J. K.

    1974-01-01

    An atmosphere control subsystem (ACS) was developed for NASA-IBJSC which is designed to measure the major atmospheric constituents in the manned cabin of the space shuttle orbiter and control the addition of oxygen and nitrogen to maintain the partial pressures of these gases within very close limits. The ACS includes a mass spectrometer sensor (MSS) which analyzes the atmosphere of a shuttle vehicle pressurized cabin, and an electronic control assembly (ECA). The MSS was built and tested to meet the requirements for flight equipment for the M-171 Metabolic Analyzer experiment for the Skylab flight program. The instrument analyzes an atmospheric gas sample and produces continuous 0-5 vdc analog signals proportional to the partial pressures of H2, O2, N2, H2O, CO2 and total hydrocarbons having a m/e ratio between 50 and 120. It accepts signals from the MSS proportional to the partial pressures of N2 and O2 and controls the supply of these gases to the closed cabin.

  5. Atmospheric reentry flight test of winged space vehicle

    NASA Astrophysics Data System (ADS)

    Inatani, Yoshifumi; Akiba, Ryojiro; Hinada, Motoki; Nagatomo, Makoto

    A summary of the atmospheric reentry flight experiment of winged space vehicle is presented. The test was conducted and carried out by the Institute of Space and Astronautical Science (ISAS) in Feb. 1992 in Kagoshima Space Center. It is the first Japanese atmospheric reentry flight of the controlled lifting vehicle. A prime objective of the flight is to demonstrate a high speed atmospheric entry flight capability and high-angle-of-attack flight capability in terms of aerodynamics, flight dynamics and flight control of these kind of vehicles. The launch of the winged vehicle was made by balloon and solid propellant rocket booster which was also the first trial in Japan. The vehicle accomplishes the lfight from space-equivalent condition to the atmospheric flight condition where reaction control system (RCS) attitude stabilization and aerodynamic control was used, respectively. In the flight, the vehicle's attitude was measured by both an inertial measurement unit (IMU) and an air data sensor (ADS) which were employed into an auto-pilot flight control loop. After completion of the entry transient flight, the vehicle experienced unexpected instability during the atmospheric decelerating flight; however, it recovered the attitude orientation and completed the transonic flight after that. The latest analysis shows that it is due to the ADS measurement error and the flight control gain scheduling; what happened was all understood. Some details of the test and the brief summary of the current status of the post flight analysis are presented.

  6. International Space Station Program Phase 3 Integrated Atmosphere Revitalization Subsystem Test

    NASA Technical Reports Server (NTRS)

    Perry, J. L.; Franks, G. D.; Knox, J. C.

    1997-01-01

    Testing of the International Space Station (ISS) U.S. Segment baseline configuration of the Atmosphere Revitalization Subsystem (ARS) by NASA's Marshall Space Flight Center (MSFC) was conducted as part of the Environmental Control and Life Support System (ECLSS) design and development program. This testing was designed to answer specific questions regarding the control and performance of the baseline ARS subassemblies in the ISS U.S. Segment configuration. These questions resulted from the continued maturation of the ISS ECLSS configuration and design requirement changes since 1992. The test used pressurized oxygen injection, a mass spectrometric major constituent analyzer, a Four-Bed Molecular Sieve Carbon Dioxide Removal Assembly, and a Trace Contaminant Control Subassembly to maintain the atmospheric composition in a sealed chamber at ISS specifications for 30 days. Human metabolic processes for a crew of four were simulated according to projected ISS mission time lines. The performance of a static feed water electrolysis Oxygen Generator Assembly was investigated during the test preparation phases; however, technical difficulties prevented its use during the integrated test. The Integrated ARS Test (IART) program built upon previous closed-door and open-door integrated testing conducted at MSFC between 1987 and 1992. It is the most advanced test of an integrated ARS conducted by NASA to demonstrate its end-to-end control and overall performance. IART test objectives, facility design, pretest analyses, test and control requirements, and test results are presented.

  7. Wet-Atmosphere Generator

    NASA Technical Reports Server (NTRS)

    Hamner, Richard M.; Mcguire, Janice K.

    1988-01-01

    Water content in gas controlled. Portable flow-control system generates nitrogen/water atmosphere having range of dew points and pressures. One use of system provides wet nitrogen for canister of wide-field camera requiring this special atmosphere. Also used to inject trace gases other than water vapor for leak testing of large vessels. Potential applications in photography, hospitals, and calibration laboratories.

  8. Genotoxicity Assessment of Chlorotrifluoroethylene Tetramer Acid using a Battery of In Vitro and In Vivo/In Vitro Assays

    DTIC Science & Technology

    1990-12-01

    Laboratory cultures were maintained as monolayers at 37 ± 1.5 0 C in a humidified atmosphere containing 5 ± 1.5% CO2 and were periodically checked for...flask, allowed to attach overnight (16 to 18 h), and exposed to the test or control article for 4 h at 37 t 1.5 0 C in a humidified atmosphere ...cultures were treated with test or control material for 4 h at 37 t 1.5 0 C in a humidified atmosphere with 5% CO2. After treatment, the cell monolayers

  9. Modeling Separate and Combined Atmospheres in BIO-Plex

    NASA Technical Reports Server (NTRS)

    Jones, Harry; Finn, Cory; Kwauk, Xianmin; Blackwell, Charles; Luna, Bernadette (Technical Monitor)

    2000-01-01

    We modeled BIO-Plex designs with separate or combined atmospheres and then simulated controlling the atmosphere composition. The BIO-Plex is the Bioregenerative Planetary Life Support Systems Test Complex, a large regenerative life support test facility under development at NASA Johnson Space Center. Although plants grow better at above-normal carbon dioxide levels, humans can tolerate even higher carbon dioxide levels. Incinerator exhaust has very high levels of carbon dioxide. An elaborate BIO-Plex design would maintain different atmospheres in the crew and plant chambers and isolate the incinerator exhaust in the airlock. This design easily controls the crew and plant carbon dioxide levels but it uses many gas processors, buffers, and controllers. If all the crew's food is grown inside BIO-Plex, all the carbon dioxide required by the plants is supplied by crew respiration and the incineration of plant and food waste. Because the oxygen mass flow must balance in a closed loop, the plants supply all the oxygen required by the crew and the incinerator. Using plants for air revitalization allows using fewer gas processors, buffers, and controllers. In the simplest design, a single combined atmosphere was used for the crew, the plant chamber, and the incinerator. All gas processors, buffers, and controllers were eliminated. The carbon dioxide levels were necessarily similar for the crew and plants. If most of the food is grown, carbon dioxide can be controlled at the desired level by scheduling incineration. An intermediate design uses one atmosphere for the crew and incinerator chambers and a second for the plant chamber. This allows different carbon dioxide levels for the crew and plants. Better control of the atmosphere is obtained by varying the incineration rate. Less gas processing storage and control is needed if more food is grown.

  10. Modeling Separate and Combined Atmospheres in BIO-Plex

    NASA Technical Reports Server (NTRS)

    Jones, Harry; Finn, Cory; Kwauk, Xian-Min; Blackwell, Charles; Luna, Bernadette (Technical Monitor)

    2000-01-01

    We modeled BIO-Plex designs with separate or combined atmospheres and then simulated controlling the atmosphere composition. The BIO-Plex is the Bioregenerative Planetary Life Support Systems Test Complex, a large regenerative life support test facility under development at NASA Johnson Space Center. Although plants grow better at above-normal carbon dioxide levels, humans can tolerate even higher carbon dioxide levels. incinerator exhaust has very high levels of carbon dioxide. An elaborate BIO-Plex design would maintain different atmospheres in the crew and plant chambers and isolate the incinerator exhaust in the airlock. This design easily controls the crew and plant carbon dioxide levels but it uses many gas processors, buffers, and controllers. If all the crew's food is grown inside BIO-Plex, all the carbon dioxide required by the plants is supplied by crew respiration and the incineration of plant and food waste. Because the oxygen mass flow must balance in a closed loop, the plants supply all the oxygen required by the crew and the incinerator. Using plants for air revitalization allows using fewer gas processors, buffers, and controllers. In the simplest design, a single combined atmosphere was used for the crew, the plant chamber, and the incinerator. All gas processors, buffers, and controllers were eliminated. The carbon dioxide levels were necessarily similar for the crew and plants. If most of the food is grown, carbon dioxide can be controlled at the desired level by scheduling incineration. An intermediate design uses one atmosphere for the crew and incinerator chambers and a second for the plant chamber. This allows different carbon dioxide levels for the crew and plants. Better control of the atmosphere is obtained by varying the incineration rate. Less gas processing, storage, and control is needed if more food is grown.

  11. Atmospheric Tracer Depletion Testing for Unfiltered Air In-Leakage Determination at the Wolf Creek Nuclear Power Plant

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

    Sullivan, T. M.; Wilke, R. J.; Roberts, T.

    Atmospheric Tracer Depletion tests were conducted at the Wolf Creek Nuclear Power Plant to quantify the unfiltered in-leakage (UI) into the Control Room (CR), Control Building (CB), and Equipment Rooms (ER) at the Wolf Creek Nuclear Power Plant. Wolf Creek has two independent charcoal filter Emergency Ventilation Systems (EVS) that can be used to purify air entering the control building and control room. The Bravo System contains a filtration system in Room 1501 in the Auxiliary Building for the Control Room and another filtration system (FGK02B) on Elevation 2016 for the Control Building. The Alpha system contains a filtration systemmore » in Room 1512 in the Auxiliary Building for the Control Room and another filtration system (FGK02A) on Elevation 2016 for the Control Building. The Atmospheric Tracer Depletion (ATD) test is a technique to measure in-leakage using the concentration of perfluorocarbon compounds that have a constant atmospheric background. These levels are present in the Control Room and Control Building under normal operating conditions. When air is supplied by either of the EVS, most of the PFTS are removed by the charcoal filters. If the concentrations of the PFTs measured in protected areas are the same as the levels at the output of the EVS, the in-leakage of outside air into the protected area would be zero. If the concentration is higher in the protected area than at the output of the filter system, there is in-leakage and the in-leakage can be quantified by the difference. Sampling was performed using state-of-the-art Brookhaven Atmospheric Tracer Samplers (BATS) air sampling equipment and analysis performed on Brookhaven National Laboratory (BNL) dedicated PFT analytical systems. In the Alpha test two tracers PMCH and mcPDCH were used to determine in-leakage into the control building. The analytical system was tuned to maximize sensitivity after initial analysis of the Alpha test. The increased sensitivity permitted accurate quantification of five isomers of the PFT PDCH (mtPDCH, pcPDCH, otPDCH, mcPDCH, and ptPDCH). These isomers were quantified in the low concentration samples in the Alpha test and in all samples in the Bravo test. The best estimates of UI (Rui) for the four zones are provided in Table ES-1. For the CB, this estimate averages the four tracers at the four elevations. For the CR, this estimate uses the four sampling units located in the Control Room.« less

  12. Atmospheric Tracer Depletion Testing for Unfiltered Air In-Leakage Determination at the Wolf Creek Nuclear Power Plant

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

    Sullivan, T. M.; Wilke, R. J.; Roberts, T.

    Atmospheric Tracer Depletion tests were conducted at the Wolf Creek Nuclear Power Plant to quantify the unfiltered in-leakage (UI) into the Control Room (CR), Control Building (CB), and Equipment Rooms (ER) at the Wolf Creek Nuclear Power Plant. Wolf Creek has two independent charcoal filter Emergency Ventilation Systems (EVS) that can be used to purify air entering the control building and control room. The Bravo System contains a filtration system in Room 1501 in the Auxiliary Building for the Control Room and another filtration system (FGK02B) on Elevation 2016 for the Control Building. The Alpha system contains a filtration systemmore » in Room 1512 in the Auxiliary Building for the Control Room and another filtration system (FGK02A) on Elevation 2016 for the Control Building.The Atmospheric Tracer Depletion (ATD) test is a technique to measure in-leakage using the concentration of perfluorocarbon compounds that have a constant atmospheric background. These levels are present in the Control Room and Control Building under normal operating conditions. When air is supplied by either of the EVS, most of the PFTS are removed by the charcoal filters. If the concentrations of the PFTs measured in protected areas are the same as the levels at the output of the EVS, the in-leakage of outside air into the protected area would be zero. If the concentration is higher in the protected area than at the output of the filter system, there is in-leakage and the in-leakage can be quantified by the difference.Sampling was performed using state-of-the-art Brookhaven Atmospheric Tracer Samplers (BATS) air sampling equipment and analysis performed on Brookhaven National Laboratory (BNL) dedicated PFT analytical systems. In the Alpha test two tracers PMCH and mcPDCH were used to determine in-leakage into the control building. The analytical system was tuned to maximize sensitivity after initial analysis of the Alpha test. The increased sensitivity permitted accurate quantification of five isomers of the PFT PDCH (mtPDCH, pcPDCH, otPDCH, mcPDCH, and ptPDCH). These isomers were quantified in the low concentration samples in the Alpha test and in all samples in the Bravo test.The best estimates of UI (Rui) for the four zones are provided in Table ES-1. For the CB, this estimate averages the four tracers at the four elevations. For the CR, this estimate uses the four sampling units located in the Control Room.« less

  13. 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.

  14. 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.

  15. Computerized atmospheric trace contaminant control simulation for manned spacecraft

    NASA Technical Reports Server (NTRS)

    Perry, J. L.

    1993-01-01

    Buildup of atmospheric trace contaminants in enclosed volumes such as a spacecraft may lead to potentially serious health problems for the crew members. For this reason, active control methods must be implemented to minimize the concentration of atmospheric contaminants to levels that are considered safe for prolonged, continuous exposure. Designing hardware to accomplish this has traditionally required extensive testing to characterize and select appropriate control technologies. Data collected since the Apollo project can now be used in a computerized performance simulation to predict the performance and life of contamination control hardware to allow for initial technology screening, performance prediction, and operations and contingency studies to determine the most suitable hardware approach before specific design and testing activities begin. The program, written in FORTRAN 77, provides contaminant removal rate, total mass removed, and per pass efficiency for each control device for discrete time intervals. In addition, projected cabin concentration is provided. Input and output data are manipulated using commercial spreadsheet and data graphing software. These results can then be used in analyzing hardware design parameters such as sizing and flow rate, overall process performance and program economics. Test performance may also be predicted to aid test design.

  16. 40 CFR 1054.115 - What other requirements apply?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... POLLUTION CONTROLS CONTROL OF EMISSIONS FROM NEW, SMALL NONROAD SPARK-IGNITION ENGINES AND EQUIPMENT... § 1054.145(c), engines must meet applicable emission standards at all specified atmospheric pressures, except that for atmospheric pressures below 94.0 kPa you may rely on an altitude kit for all testing if...

  17. Compact Analyzer/Controller For Oxygen-Enrichment System

    NASA Technical Reports Server (NTRS)

    Puster, Richard L.; Singh, Jag J.; Sprinkle, Danny R.

    1990-01-01

    System controls hypersonic air-breathing engine tests. Compact analyzer/controller developed, built, and tested in small-scale wind tunnel prototype of the 8' HTT (High-Temperature Tunnel). Monitors level of oxygen and controls addition of liquid oxygen to enrich atmosphere for combustion. Ensures meaningful ground tests of hypersonic engines in range of speeds from mach 4 to mach 7.

  18. Entry Atmospheric Flight Control Authority Impacts on GN and C and Trajectory Performance for Orion Exploration Flight Test 1

    NASA Technical Reports Server (NTRS)

    McNamara, Luke W.

    2012-01-01

    One of the key design objectives of NASA's Orion Exploration Flight Test 1 (EFT-1) is to execute a guided entry trajectory demonstrating GN&C capability. The focus of this paper is the ight control authority of the vehicle throughout the atmospheric entry ight to the target landing site and its impacts on GN&C, parachute deployment, and integrated performance. The vehicle's attitude control authority is obtained from thrusting 12 Re- action Control System (RCS) engines, with four engines to control yaw, four engines to control pitch, and four engines to control roll. The static and dynamic stability derivatives of the vehicle are determined to assess the inherent aerodynamic stability. The aerodynamic moments at various locations in the entry trajectory are calculated and compared to the available torque provided by the RCS system. Interaction between the vehicle's RCS engine plumes and the aerodynamic conditions are considered to assess thruster effectiveness. This document presents an assessment of Orion's ight control authority and its effectiveness in controlling the vehicle during critical events in the atmospheric entry trajectory.

  19. A new test machine for measuring friction and wear in controlled atmospheres to 1200 C

    NASA Technical Reports Server (NTRS)

    Sliney, Harold E.; Dellacorte, Christopher

    1991-01-01

    This paper describes a new high-temperature friction and wear test apparatus (tribometer). The tribometer can be used as a pin-on-disk or pin-on-ring configuration and is specially designed to measure the tribological properties of ceramics and high temperature metallic alloys from room temperature to 1200 C. Sliding mode can be selected to be either unidirectional at velocities up to 22 m/sec or oscillating at frequencies up to 4.6 Hz and amplitudes up to + or - 60 deg. The test atmosphere is established by a controlled flow rate of a purge gas. All components within the test chamber are compatible with oxidizing, inert or reducing gases.

  20. Entry vehicle performance analysis and atmospheric guidance algorithm for precision landing on Mars. M.S. Thesis - Massachusetts Inst. of Technology

    NASA Technical Reports Server (NTRS)

    Dieriam, Todd A.

    1990-01-01

    Future missions to Mars may require pin-point landing precision, possibly on the order of tens of meters. The ability to reach a target while meeting a dynamic pressure constraint to ensure safe parachute deployment is complicated at Mars by low atmospheric density, high atmospheric uncertainty, and the desire to employ only bank angle control. The vehicle aerodynamic performance requirements and guidance necessary for 0.5 to 1.5 lift drag ratio vehicle to maximize the achievable footprint while meeting the constraints are examined. A parametric study of the various factors related to entry vehicle performance in the Mars environment is undertaken to develop general vehicle aerodynamic design requirements. The combination of low lift drag ratio and low atmospheric density at Mars result in a large phugoid motion involving the dynamic pressure which complicates trajectory control. Vehicle ballistic coefficient is demonstrated to be the predominant characteristic affecting final dynamic pressure. Additionally, a speed brake is shown to be ineffective at reducing the final dynamic pressure. An adaptive precision entry atmospheric guidance scheme is presented. The guidance uses a numeric predictor-corrector algorithm to control downrange, an azimuth controller to govern crossrange, and analytic control law to reduce the final dynamic pressure. Guidance performance is tested against a variety of dispersions, and the results from selected tests are presented. Precision entry using bank angle control only is demonstrated to be feasible at Mars.

  1. High-temperature controlled atmosphere for post-harvest control of Indian meal moth (Lepidoptera: Pyralidae) on preserved flowers.

    PubMed

    Sauer, Jodi A; Shelton, Mark D

    2002-10-01

    High carbon dioxide atmospheres combined with high temperature were effective for controlling Indian meal moth, Plodia interpunctella (Hübner) pupae. Pupae were exposed to atmospheres of 60, 80, or 98% carbon dioxide (CO2) in nitrogen (N2), or 60 or 80% CO2 in air at temperatures of 26.7 degrees C or 32.2 degrees C and 60% RH. Controlled atmosphere treatments at 32.2 degrees C controlled pupae faster than the same treatments at the lower temperature. At both temperatures high CO2 concentration treatments combined with nitrogen killed pupae faster than high CO2 concentration treatments combined with air. Exposure to 80% carbon dioxide mixed with nitrogen was the most effective treatment causing 100% mortality in 12 h at 32.2 degrees C and 93.3% mortality in 18 h at 26.6 degrees C. High-temperature controlled atmosphere treatments had no adverse effects on quality of two preserved floral products, Limonium sinuatum (L.) and Gypsophila elegans (Bieb.), tested for 12, 18, and 24 h according to industry standards.

  2. Atmosphere Explorer control system software (version 1.0)

    NASA Technical Reports Server (NTRS)

    Villasenor, A.

    1972-01-01

    The basic design is described of the Atmosphere Explorer Control System (AECS) software used in the testing, integration, and flight contol of the AE spacecraft and experiments. The software performs several vital functions, such as issuing commands to the spacecraft and experiments, receiving and processing telemetry data, and allowing for extensive data processing by experiment analysis programs. The major processing sections are: executive control section, telemetry decommutation section, command generation section, and utility section.

  3. Overview of the International Space Station System Level Trace Contaminant Injection Test

    NASA Technical Reports Server (NTRS)

    Tatara, James D.; Perry, Jay L.; Franks, Gerald D.

    1997-01-01

    Trace contaminant control onboard the International Space Station will be accomplished not only by the Trace Contaminant Control Subassembly but also by other Environmental Control and Life Support System subassemblies. These additional removal routes include absorption by humidity condensate in the Temperature and Humidity Control Condensing Heat Exchanger and adsorption by the Carbon Dioxide Removal Assembly. The Trace Contaminant Injection Test, which was performed at NASA's Marshall Space Flight Center, investigated the system-level removal of trace contaminants by the International Space Station Atmosphere Revitalization, and Temperature/Humidity Control Subsystems, (November-December 1997). It is a follow-on to the Integrated Atmosphere Revitalization Test conducted in 1996. An estimate for the magnitude of the assisting role provided by the Carbon Dioxide Removal Assembly and the Temperature and Humidity Control unit was obtained. In addition, data on the purity of Carbon Dioxide Removal Assembly carbon dioxide product were obtained to support Environmental Control and Life Support System Air Revitalization Subsystem loop closure.

  4. Absorption of carbon dioxide by solid hydroxide sorbent beds in closed-loop atmospheric revitalization system

    NASA Technical Reports Server (NTRS)

    Davis, S. H., Jr.; Kissinger, L. D.

    1982-01-01

    The reactions of carbon dioxide with various metals are discussed. The equations which govern the rates of CO2 removal from the atmosphere in spacecraft environmental control systems are discussed. Results from performance testing of various Space Shuttle environmental control systems are presented with the correlation of the equations to the performance given.

  5. A new instrument for measuring optical transmission in the atmosphere

    NASA Astrophysics Data System (ADS)

    Kaurila, Timo A.

    2007-04-01

    It is an important task to measure optical transmission of the atmosphere when testing the performance of electro-optical systems such as thermal imagers. Only by knowing atmospheric transmission precisely enough, we will be able to eliminate effects of the atmosphere on test results. For this reason a new instrument that measures optical transmission in the atmosphere has been constructed. The transmissometer consists of a transmitter/receiver unit, a reflector and control software. The instrument measures atmospheric transmission at wavelength of 1 μm and 8-12 μm by comparing the intensity of the beam propagating through the atmosphere and the reference beam inside the transmitter/receiver unit. Calibration is carried out by the aid of a visibility meter and a special calibration algorithm. An important criterion for the design was to create an instrument which could be used flexibly in field measurements. The transmissometer was tested comprehensively in the field in March and June 2006. It can measure extinction coefficients up to 3 - 12 km -1 depending on the span between the transmitter/receiver unit and reflector with accuracy of 10 - 20 %. According to the test measurements the transmissometer also fulfills the other requirement specifications.

  6. An Atmospheric Guidance Algorithm Testbed for the Mars Surveyor Program 2001 Orbiter and Lander

    NASA Technical Reports Server (NTRS)

    Striepe, Scott A.; Queen, Eric M.; Powell, Richard W.; Braun, Robert D.; Cheatwood, F. McNeil; Aguirre, John T.; Sachi, Laura A.; Lyons, Daniel T.

    1998-01-01

    An Atmospheric Flight Team was formed by the Mars Surveyor Program '01 mission office to develop aerocapture and precision landing testbed simulations and candidate guidance algorithms. Three- and six-degree-of-freedom Mars atmospheric flight simulations have been developed for testing, evaluation, and analysis of candidate guidance algorithms for the Mars Surveyor Program 2001 Orbiter and Lander. These simulations are built around the Program to Optimize Simulated Trajectories. Subroutines were supplied by Atmospheric Flight Team members for modeling the Mars atmosphere, spacecraft control system, aeroshell aerodynamic characteristics, and other Mars 2001 mission specific models. This paper describes these models and their perturbations applied during Monte Carlo analyses to develop, test, and characterize candidate guidance algorithms.

  7. Development of a low cost unmanned aircraft system for atmospheric carbon dioxide leak detection

    NASA Astrophysics Data System (ADS)

    Mitchell, Taylor Austin

    Carbon sequestration, the storage of carbon dioxide gas underground, has the potential to reduce global warming by removing a greenhouse gas from the atmosphere. These storage sites, however, must first be monitored to detect if carbon dioxide is leaking back out to the atmosphere. As an alternative to traditional large ground-based sensor networks to monitor CO2 levels for leaks, unmanned aircraft offer the potential to perform in-situ atmospheric leak detection over large areas for a fraction of the cost. This project developed a proof-of-concept sensor system to map relative carbon dioxide levels to detect potential leaks. The sensor system included a Sensair K-30 FR CO2 sensor, GPS, and altimeter connected an Arduino microcontroller which logged data to an onboard SD card. Ground tests were performed to verify and calibrate the system including wind tunnel tests to determine the optimal configuration of the system for the quickest response time (4-8 seconds based upon flowrate). Tests were then conducted over a controlled release of CO 2 in addition to over controlled rangeland fires which released carbon dioxide over a large area as would be expected from a carbon sequestration source. 3D maps of carbon dioxide were developed from the system telemetry that clearly illustrated increased CO2 levels from the fires. These tests demonstrated the system's ability to detect increased carbon dioxide concentrations in the atmosphere.

  8. A new test machine for measuring friction and wear in controlled atmospheres to 1200 C

    NASA Technical Reports Server (NTRS)

    Sliney, Harold E.; Dellacorte, Christopher

    1989-01-01

    This paper describes a new high temperature friction and wear test apparatus (tribometer) at NASA Lewis Research Center, Cleveland, Ohio. The tribometer can be used as a pin-on-disk or pin-on-ring configuration and is specially designed to measure the tribological properties of ceramics and high temperature metallic alloys from room temperature to 1200 C. Sliding mode can be selected to be either unidirectional at velocities up to 22 m/sec or oscillating at frequencies up 4.5 Hz and amplitudes up to + or - 60 deg. The test atmosphere is established by a controlled flow rate of a purge gas. All components within the test chamber are compatible with oxidizing, inert, or reducing gases.

  9. Upper Atmospheric Monitoring for Ares I-X Ascent Loads and Trajectory Evaluation on the Day-of-Launch

    NASA Technical Reports Server (NTRS)

    Roberts, Barry C.; McGrath, Kevin; Starr, Brett; Brandon, Jay

    2009-01-01

    During the launch countdown of the Ares I-X test vehicle, engineers from Langley Research Center will use profiles of atmospheric density and winds in evaluating vehicle ascent loads and controllability. A schedule for the release of balloons to measure atmospheric density and winds has been developed by the Natural Environments Branch at Marshall Space Flight Center to help ensure timely evaluation of the vehicle ascent loads and controllability parameters and support a successful launch of the Ares I-X vehicle.

  10. Pulse-modulated dual-gas control subsystem for space cabin atmosphere

    NASA Technical Reports Server (NTRS)

    Jackson, J. K.

    1974-01-01

    An atmosphere control subsystem (ACS) was developed for use in a closed manned cabin, such as the Space Shuttle Orbiter. This subsystem uses the Perkin Elmer mass spectrometer for continuous measurement of major atmospheric constituents (H2, H2O, N2, O2, and CO2). The O2 and N2 analog signals are used as inputs to the controller, which produces a pulse-frequency-modulated output to operate the N2 gas admission solenoid valve and an on-off signal to operate the O2 valve. The proportional controller characteristic results in improved control accuracy as compared with previously used on-off controllers having significant dead-band. A 60-day evaluation test was performed on the ACS during which operation was measured at various values of control setpoint and simulated cabin leakage.

  11. Statistical analysis of long-term monitoring data for persistent organic pollutants in the atmosphere at 20 monitoring stations broadly indicates declining concentrations.

    PubMed

    Kong, Deguo; MacLeod, Matthew; Hung, Hayley; Cousins, Ian T

    2014-11-04

    During recent decades concentrations of persistent organic pollutants (POPs) in the atmosphere have been monitored at multiple stations worldwide. We used three statistical methods to analyze a total of 748 time series of selected POPs in the atmosphere to determine if there are statistically significant reductions in levels of POPs that have had control actions enacted to restrict or eliminate manufacture, use and emissions. Significant decreasing trends were identified in 560 (75%) of the 748 time series collected from the Arctic, North America, and Europe, indicating that the atmospheric concentrations of these POPs are generally decreasing, consistent with the overall effectiveness of emission control actions. Statistically significant trends in synthetic time series could be reliably identified with the improved Mann-Kendall (iMK) test and the digital filtration (DF) technique in time series longer than 5 years. The temporal trends of new (or emerging) POPs in the atmosphere are often unclear because time series are too short. A statistical detrending method based on the iMK test was not able to identify abrupt changes in the rates of decline of atmospheric POP concentrations encoded into synthetic time series.

  12. Performance Testing of a Photocatalytic Oxidation Module for Spacecraft Cabin Atmosphere Revitalization

    NASA Technical Reports Server (NTRS)

    Perry, Jay L.; Abney, Morgan B.; Frederick, Kenneth R.; Scott, Joseph P.; Kaiser, Mark; Seminara, Gary; Bershitsky, Alex

    2011-01-01

    Photocatalytic oxidation (PCO) is a candidate process technology for use in high volumetric flow rate trace contaminant control applications in sealed environments. The targeted application for PCO as applied to crewed spacecraft life support system architectures is summarized. Technical challenges characteristic of PCO are considered. Performance testing of a breadboard PCO reactor design for mineralizing polar organic compounds in a spacecraft cabin atmosphere is described. Test results are analyzed and compared to results reported in the literature for comparable PCO reactor designs.

  13. Experimental Modeling of Sterilization Effects for Atmospheric Entry Heating on Microorganisms

    NASA Technical Reports Server (NTRS)

    Schubert, Wayne W.; Spry, James A.; Ronney, Paul D.; Pandian, Nathan R.; Welder, Eric

    2012-01-01

    The objective of this research was to design, build, and test an experimental apparatus for studying the parameters of atmospheric entry heating, and the inactivation of temperature-resistant bacterial spores. The apparatus is capable of controlled, rapid heating of sample coupons to temperatures of 200 to 350 C and above. The vacuum chamber permits operation under vacuum or special atmospheric gas mixtures.

  14. Study on the total amount control of atmospheric pollutant based on GIS.

    PubMed

    Wang, Jian-Ping; Guo, Xi-Kun

    2005-08-01

    To provide effective environmental management for total amount control of atmospheric pollutants. An atmospheric diffusion model of sulfur dioxide on the surface of the earth was established and tested in Shantou of Guangdong Province on the basis of an overall assessment of regional natural environment, social economic state of development, pollution sources and atmospheric environmental quality. Compared with actual monitoring results in a studied region, simulation values fell within the range of two times of error and were evenly distributed in the two sides of the monitored values. Predicted with the largest emission model method, the largest emission of sulfur dioxide would be 54,279.792 tons per year in 2010. The mathematical model established and revised on the basis of GIS is more rational and suitable for the regional characteristics of total amount control of air pollutants.

  15. Microprocessor-controlled laser tracker for atmospheric sensing

    NASA Technical Reports Server (NTRS)

    Johnson, R. A.; Webster, C. R.; Menzies, R. T.

    1985-01-01

    An optical tracking system comprising a visible HeNe laser, an imaging detector, and a microprocessor-controlled mirror, has been designed to track a moving retroreflector located up to 500 m away from an atmospheric instrument and simultaneously direct spectrally tunable infrared laser radiation to the retroreflector for double-ended, long-path absorption measurements of atmospheric species. The tracker has been tested during the recent flight of a balloon-borne tunable diode laser absorption spectrometer which monitors the concentrations of stratospheric species within a volume defined by a 0.14-m-diameter retroreflector lowered 500 m below the instrument gondola.

  16. Continuous flow, explosives vapor generator and sensor chamber.

    PubMed

    Collins, Greg E; Giordano, Braden C; Sivaprakasam, Vasanthi; Ananth, Ramagopal; Hammond, Mark; Merritt, Charles D; Tucker, John E; Malito, Michael; Eversole, Jay D; Rose-Pehrsson, Susan

    2014-05-01

    A novel liquid injection vapor generator (LIVG) is demonstrated that is amenable to low vapor pressure explosives, 2,4,6-trinitrotoluene and hexahydro-1,3,5-trinitro-1,3,5-triazine. The LIVG operates in a continuous manner, providing a constant and stable vapor output over a period of days and whose concentration can be extended over as much as three orders of magnitude. In addition, a large test atmosphere chamber attached to the LIVG is described, which enables the generation of a stable test atmosphere with controllable humidity and temperature. The size of the chamber allows for the complete insertion of testing instruments or arrays of materials into a uniform test atmosphere, and various electrical feedthroughs, insertion ports, and sealed doors permit simple and effective access to the sample chamber and its vapor.

  17. 40 CFR 798.2450 - Inhalation toxicity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... study. (2) Control groups. A concurrent control group is required. This group shall be an untreated or sham-treated control group. Except for treatment with the test substance, animals in the control group... generate an appropriate concentration of the substance in the atmosphere, a vehicle control group shall be...

  18. 40 CFR 798.2450 - Inhalation toxicity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... study. (2) Control groups. A concurrent control group is required. This group shall be an untreated or sham-treated control group. Except for treatment with the test substance, animals in the control group... generate an appropriate concentration of the substance in the atmosphere, a vehicle control group shall be...

  19. 40 CFR 798.2450 - Inhalation toxicity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... study. (2) Control groups. A concurrent control group is required. This group shall be an untreated or sham-treated control group. Except for treatment with the test substance, animals in the control group... generate an appropriate concentration of the substance in the atmosphere, a vehicle control group shall be...

  20. 40 CFR 798.2450 - Inhalation toxicity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... study. (2) Control groups. A concurrent control group is required. This group shall be an untreated or sham-treated control group. Except for treatment with the test substance, animals in the control group... generate an appropriate concentration of the substance in the atmosphere, a vehicle control group shall be...

  1. 40 CFR 798.2450 - Inhalation toxicity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... study. (2) Control groups. A concurrent control group is required. This group shall be an untreated or sham-treated control group. Except for treatment with the test substance, animals in the control group... generate an appropriate concentration of the substance in the atmosphere, a vehicle control group shall be...

  2. A procedure for testing the quality of LANDSAT atmospheric correction algorithms

    NASA Technical Reports Server (NTRS)

    Dias, L. A. V. (Principal Investigator); Vijaykumar, N. L.; Neto, G. C.

    1982-01-01

    There are two basic methods for testing the quality of an algorithm to minimize atmospheric effects on LANDSAT imagery: (1) test the results a posteriori, using ground truth or control points; (2) use a method based on image data plus estimation of additional ground and/or atmospheric parameters. A procedure based on the second method is described. In order to select the parameters, initially the image contrast is examined for a series of parameter combinations. The contrast improves for better corrections. In addition the correlation coefficient between two subimages, taken at different times, of the same scene is used for parameter's selection. The regions to be correlated should not have changed considerably in time. A few examples using this proposed procedure are presented.

  3. VANDENBERG AIR FORCE BASE, CALIF. - The L-1011 carrier aircraft is ready for flight after undergoing a Combined Systems Test, an integrated test involving the Pegasus launch vehicle, SciSat-1 spacecraft and L-1011 aircraft. The SciSat-1 weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

    NASA Image and Video Library

    2003-08-09

    VANDENBERG AIR FORCE BASE, CALIF. - The L-1011 carrier aircraft is ready for flight after undergoing a Combined Systems Test, an integrated test involving the Pegasus launch vehicle, SciSat-1 spacecraft and L-1011 aircraft. The SciSat-1 weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

  4. VANDENBERG AIR FORCE BASE, CALIF.- The covered SciSat-1 spacecraft is lowered onto a test stand at Vandenberg Air Force Base, Calif., for functional testing. The solar arrays will be attached and the communications systems checked out. The SciSat-1 weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

    NASA Image and Video Library

    2003-07-29

    VANDENBERG AIR FORCE BASE, CALIF.- The covered SciSat-1 spacecraft is lowered onto a test stand at Vandenberg Air Force Base, Calif., for functional testing. The solar arrays will be attached and the communications systems checked out. The SciSat-1 weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

  5. Robust Control Design for Flight Control

    DTIC Science & Technology

    1989-07-01

    controller may be designed to produce desired responses to pilot commands, responses to external (atmospheric) disturbances may be unusual and...suggested for stabilizing open loop unstable aircraft result in nonminimum phase zeros in the dynamics as seen by the pilot . This issue has not been...stability test it does retain several essential features of the popular single loop test developed by Nyquist. In particular, it identifies a Nyquist

  6. 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.

  7. Conceptual study and key technology development for Mars Aeroflyby sample collection

    NASA Astrophysics Data System (ADS)

    Fujita, K.; Ozawa, T.; Okudaira, K.; Mikouchi, T.; Suzuki, T.; Takayanagi, H.; Tsuda, Y.; Ogawa, N.; Tachibana, S.; Satoh, T.

    2014-01-01

    Conceptual study of Mars Aeroflyby Sample Collection (MASC) is conducted as a part of the next Mars exploration mission currently entertained in Japan Aerospace Exploration Agency. In the mission scenario, an atmospheric entry vehicle is flown into the Martian atmosphere, collects the Martian dust particles as well as atmospheric gases during the guided hypersonic flight, exits the Martian atmosphere, and is inserted into a parking orbit from which a return system departs for the earth to deliver the dust and gas samples. In order to accomplish a controlled flight and a successful orbit insertion, aeroassist orbit transfer technologies are introduced into the guidance and control system. System analysis is conducted to assess the feasibility and to make a conceptual design, finding that the MASC system is feasible at the minimum system mass of 600 kg approximately. The aerogel, which is one of the candidates for the dust sample collector, is assessed by arcjet heating tests to examine its behavior when exposed to high-temperature gases, as well as by particle impingement tests to evaluate its dust capturing capability.

  8. Toxic effects of six plant oils alone and in combination with controlled atmosphere on Liposcelis bostrychophila (Psocoptera: Liposcelididae).

    PubMed

    Wang, J J; Tsai, J H; Ding, W; Zhao, Z M; Li, L S

    2001-10-01

    Six plant essential oils alone as repellent and fumigant, and in combination with the controlled atmosphere against Liposcelis bostrychophila Badonnel were assessed in the laboratory. These essential oils were extracted from the leaves of six source plants: Citrus tangerina Tanaka, Citrus aurantium L., Citrus bergamia Risso et Poiteau, Pinus sylvestris L., Cupressus funebris End]., and Eucalyptus citriodora Hook. The repellency test indicated that L. bostrychophila adults were repelled by filter paper strips treated with six essential oils. Of these essential oils, the C. funebris oil was most effective followed by that of F. sylvestris, C. tangerina, C. bergamia, and E. citriodora. The average repellency of the C. aurantium oil against L. bostrychophila adults was significantly lower than other five test oils by day 14. These essential oils had a high level of toxicity in the fumigation assay against L. bostrychophila adults at both 10 and 20 ppm. When combined with two controlled atmosphere treatments (12% CO2 + 9% O2, and 10% CO2 + 5% O2, balanced N2), the toxicity of plant oils was enhanced significantly.

  9. Controlled Atmosphere High Temperature SPM for electrochemical measurements

    NASA Astrophysics Data System (ADS)

    Vels Hansen, K.; Sander, C.; Koch, S.; Mogensen, M.

    2007-03-01

    A new controlled atmosphere high temperature SPM has been designed and build for the purpose of performing electrochemical measurements on solid oxide fuel cell materials. The first tests show that images can be obtained at a surface temperature of 465°C in air with a standard AFM AC probe. The aim is to produce images at a surface temperature of 800°C with electrically conducting ceramic probes as working electrodes that can be positioned at desired locations at the surface for electrochemical measurements.

  10. Testing Plant Responses to Rarified Atmospheres for Inflatable Greenhouses

    NASA Technical Reports Server (NTRS)

    Corey, Kenneth A.

    2000-01-01

    Reduced atmospheric pressures will likely be used to minimize mass and engineering requirements for plant growth habitats used in extraterrestrial applications. A chamber with high vacuum capability was used to design and begin construction of a system for testing plant responses to reduced pressure atmospheres. Several preliminary tests were conducted to evaluate chamber suitability for plant tests and to determine performance of thermal and vacuum systems at ambient and reduced pressure atmospheres down to 0.1 atm. The first tests consisted of measurements of internal gas volume and leakage rate. The method for volume determination was quite sensitive and will be needed for plant gas exchange measurements and calculations. This information will also be used in conjunction with the leak rate. Measured leak rates on the order of 0.46 mm Hg/min at 76 mm Hg pressure are low enough to conduct sensitive carbon dioxide exchange rate measurements at reduced pressure given an adequate plant sample (0.5 to 1.0 sq m area). A test rack with lighting provided by three high-pressure sodium vapor lamps was built to accommodate both short-term and long-term plant responses. Initial short-term experiments with lettuce showed that a pressure of 77 mm Hg resulted in a 6.1-fold increase in the rate of water loss compared to water loss at ambient pressure. Plants were severely wilted after 30 minutes exposure to 77 mm Hg. Water loss was found to be inversely correlated with atmospheric pressure over the range of pressures from 0.2 to 1.0 atm; the rate of water loss at 0.2 atm was 4.3 times higher than water loss at ambient pressure. Older leaves showed moderate wilting during exposure to 156 mm Hg, but those exposed to 345 mm, Hg remained turgid. Results suggest a reduced atmospheric pressure limit of 0.2 to 0.3 atm for lettuce grown in a solid medium. Follow-up experiments with carbon dioxide control and control at high relative humidity (> 90 %) will be needed to further confirm and define safe reduced pressure limits that are feasible for plant tolerance and growth.

  11. Process Upsets Involving Trace Contaminant Control Systems

    NASA Technical Reports Server (NTRS)

    Graf, John C.; Perry, Jay; Wright, John; Bahr, Jim

    2000-01-01

    Paradoxically, trace contaminant control systems that suffer unexpected upsets and malfunctions can release hazardous gaseous contaminants into a spacecraft cabin atmosphere causing potentially serious toxicological problems. Trace contaminant control systems designed for spaceflight typically employ a combination of adsorption beds and catalytic oxidation reactors to remove organic and inorganic trace contaminants from the cabin atmosphere. Interestingly, the same design features and attributes which make these systems so effective for purifying a spacecraft's atmosphere can also make them susceptible to system upsets. Cabin conditions can be contributing causes of phenomena such as adsorbent "rollover" and catalyst poisoning can alter a systems performance and in some in stances release contamination into the cabin. Evidence of these phenomena has been observed both in flight and during ground-based tests. The following discussion describes specific instances of system upsets found in trace contaminant control systems, groups these specific upsets into general hazard classifications, and recommends ways to minimize these hazards.

  12. 40 CFR 799.9130 - TSCA acute inhalation toxicity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of the substance in the atmosphere, a vehicle control group should be used when historical data are... system to assign animals to test groups and control groups randomly is required. (2) Control groups. A concurrent untreated control group is not necessary. Where a vehicle other than water is used to generate an...

  13. 40 CFR 799.9130 - TSCA acute inhalation toxicity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of the substance in the atmosphere, a vehicle control group should be used when historical data are... system to assign animals to test groups and control groups randomly is required. (2) Control groups. A concurrent untreated control group is not necessary. Where a vehicle other than water is used to generate an...

  14. 40 CFR 799.9130 - TSCA acute inhalation toxicity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of the substance in the atmosphere, a vehicle control group should be used when historical data are... system to assign animals to test groups and control groups randomly is required. (2) Control groups. A concurrent untreated control group is not necessary. Where a vehicle other than water is used to generate an...

  15. JF-104 ground testing reaction control system (RCS) jets

    NASA Technical Reports Server (NTRS)

    1961-01-01

    JF-104A (formerly YF-104A, serial # 55-2961) was modifed with a hydrogen peroxide reaction control system (RCS). Following a zoom climb to altitudes in the vicinity of 80,000 feet, the RCS system gave the aircraft controllability in the thin upper atmosphere where conventional control surfaces are ineffective.

  16. Control of the Earth's electric field intensity through solar wind modulation of galactic cosmic radiation: Support for a proposed atmospheric electrical sun-weather mechanism

    NASA Technical Reports Server (NTRS)

    Markson, R.

    1980-01-01

    The ionospheric potential and galactic cosmic radiation, found to be inversely correlated with the solar wind velocity are examined as being germane to weather modification. Since the ionospheric potential is proportional to the fair weather electric field intensity and cosmic radiation is the dominant source of atmospheric ionization, it is concluded that the Earth's overall electric field varies in phase with atmospheric ionization and that the latter is modulated by the solar wind. A proposed mechanism, in which solar control of ionizing radiation influences atmospheric electrification and thus possibly cloud physical processes is discussed. An experimental approach to critically test the proposed mechanism through comparison of the temporal variation of the Earth's electric field with conditions in the interplanetary medium is outlined.

  17. A constant altitude flight survey method for mapping atmospheric ambient pressures and systematic radar errors

    NASA Technical Reports Server (NTRS)

    Larson, T. J.; Ehernberger, L. J.

    1985-01-01

    The flight test technique described uses controlled survey runs to determine horizontal atmospheric pressure variations and systematic altitude errors that result from space positioning measurements. The survey data can be used not only for improved air data calibrations, but also for studies of atmospheric structure and space positioning accuracy performance. The examples presented cover a wide range of radar tracking conditions for both subsonic and supersonic flight to an altitude of 42,000 ft.

  18. Design and testing of the reactor-internal hydraulic control rod drive for the nuclear heating plant

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

    Batheja, P.; Meier, W.J.; Rau, P.J.

    A hydraulically driven control rod is being developed at Kraftwerk Union for integration in the primary system of a small nuclear district heating reactor. An elaborate test program, under way for --3 yr, was initiated with a plexiglass rig to understand the basic principles. A design specification list was prepared, taking reactor boundary conditions and relevant German rules and regulations into account. Subsequently, an atmospheric loop for testing of components at 20 to 90/sup 0/C was erected. The objectives involved optimization of individual components such as a piston/cylinder drive unit, electromagnetic valves, and an ultrasonic position indication system as wellmore » as verification of computer codes. Based on the results obtained, full-scale components were designed and fabricated for a prototype test rig, which is currently in operation. Thus far, all atmospheric tests in this rig have been completed. Investigations under reactor temperature and pressure, followed by endurance tests, are under way. All tests to date have shown a reliable functioning of the hydraulic drive, including a novel ultrasonic position indication system.« less

  19. Space shuttle orbiter reaction control system jet interaction study

    NASA Technical Reports Server (NTRS)

    Rausch, J. R.

    1975-01-01

    The space shuttle orbiter has forward mounted and rear mounted Reaction Control Systems (RCS) which are used for orbital maneuvering and also provide control during entry and abort maneuvers in the atmosphere. The effects of interaction between the RCS jets and the flow over the vehicle in the atmosphere are studied. Test data obtained in the NASA Langley Research Center 31 inch continuous flow hypersonic tunnel at a nominal Mach number of 10.3 is analyzed. The data were obtained with a 0.01 scale force model with aft mounted RCS nozzles mounted on the sting off of the force model balance. The plume simulations were accomplished primarily using air in a cold gas simulation through scaled nozzles, however, various cold gas mixtures of Helium and Argon were also tested. The effect of number of nozzles was tested as were limited tests of combined controls. The data show that RCS nozzle exit momentum ratio is the primary correlating parameter for effects where the plume impinges on an adjacent surface and mass flow ratio is the parameter where the plume interaction is primarily with the external stream. An analytic model of aft mounted RCS units was developed in which the total reaction control moments are the sum of thrust, impingement, interaction, and cross-coupling terms.

  20. Initial accomplishments of the Environmental Control and Life Support System (ECLSS) atmosphere revitalization (AR) predevelopment operational system test (POST) for the Space Station Freedom (SSF)

    NASA Technical Reports Server (NTRS)

    Dunn, Kevin H.; Bulgajewski, Peter J.

    1992-01-01

    Initial results of the integrated AR POST conducted by Boeing at Marshall Space Flight Center in 1992 are presented. The three baselined ECLSS Man Tended Capability AR assemblies were integrated and operated in a closed door chamber in which the internal atmosphere was monitored. The test provides a prerequisite checkout of the AR subsystem in preparation for longer duration tests in which the AR subsystem will be integrated with the Water Recovery Management subsystem. The integrated AR POST will serve as an early test bed to evaluate the integration of the space station ECLSS AR subsystem during design maturation.

  1. Testing and Selection of Fire-Resistant Materials for Spacecraft Use

    NASA Technical Reports Server (NTRS)

    Friedman, Robert; Jackson, Brian; Olson, Sandra

    2000-01-01

    Spacecraft fire-safety strategy emphasizes prevention, mostly through the selection of onboard items classified accord- ing to their fire resistance. The principal NASA acceptance tests described in this paper assess the flammability of materials and components under "worst-case" normal-gravity conditions of upward flame spread in controlled-oxygen atmospheres. Tests conducted on the ground, however, cannot duplicate the unique fire characteristics in the nonbuoyant low-gravity environment of orbiting spacecraft. Research shows that flammability an fire-spread rates in low gravity are sensitive to forced convection (ventilation flows) and atmospheric-oxygen concentration. These research results are helping to define new material-screening test methods that will better evaluate material performance in spacecraft.

  2. Mechanical properties of anodized coatings over molten aluminum alloy

    DOE PAGES

    Grillet, Anne M.; Gorby, Allen D.; Trujillo, Steven M.; ...

    2007-10-22

    A method to measure interfacial mechanical properties at high temperatures and in a controlled atmosphere has been developed to study anodized aluminum surface coatings at temperatures where the interior aluminum alloy is molten. This is the first time that the coating strength has been studied under these conditions. In this study, we have investigated the effects of ambient atmosphere, temperature, and surface finish on coating strength for samples of aluminum alloy 7075. Surprisingly, the effective Young's modulus or strength of the coating when tested in air was twice as high as when samples were tested in an inert nitrogen ormore » argon atmosphere. Additionally, the effective Young's modulus of the anodized coating increased with temperature in an air atmosphere but was independent of temperature in an inert atmosphere. The effect of surface finish was also examined. Sandblasting the surface prior to anodization was found to increase the strength of the anodized coating with the greatest enhancement noted for a nitrogen atmosphere. Lastly, machining marks were not found to significantly affect the strength.« less

  3. VANDENBERG AIR FORCE BASE, CALIF. - At Vandenberg AFB, Calif., a solar array is tested before installing on the SciSat-1 spacecraft. The SciSat-1 weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

    NASA Image and Video Library

    2003-07-29

    VANDENBERG AIR FORCE BASE, CALIF. - At Vandenberg AFB, Calif., a solar array is tested before installing on the SciSat-1 spacecraft. The SciSat-1 weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

  4. 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

  5. Environmental assessment for the Atmospheric Radiation Measurement (ARM) Program: Southern Great Plains Cloud and Radiation Testbed (CART) site

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

    Policastro, A.J.; Pfingston, J.M.; Maloney, D.M.

    The Atmospheric Radiation Measurement (ARM) Program is aimed at supplying improved predictive capability of climate change, particularly the prediction of cloud-climate feedback. The objective will be achieved by measuring the atmospheric radiation and physical and meteorological quantities that control solar radiation in the earth`s atmosphere and using this information to test global climate and related models. The proposed action is to construct and operate a Cloud and Radiation Testbed (CART) research site in the southern Great Plains as part of the Department of Energy`s Atmospheric Radiation Measurement Program whose objective is to develop an improved predictive capability of global climatemore » change. The purpose of this CART research site in southern Kansas and northern Oklahoma would be to collect meteorological and other scientific information to better characterize the processes controlling radiation transfer on a global scale. Impacts which could result from this facility are described.« less

  6. Bootstrap inversion technique for atmospheric trace gas source detection and quantification using long open-path laser measurements

    NASA Astrophysics Data System (ADS)

    Alden, Caroline B.; Ghosh, Subhomoy; Coburn, Sean; Sweeney, Colm; Karion, Anna; Wright, Robert; Coddington, Ian; Rieker, Gregory B.; Prasad, Kuldeep

    2018-03-01

    Advances in natural gas extraction technology have led to increased activity in the production and transport sectors in the United States and, as a consequence, an increased need for reliable monitoring of methane leaks to the atmosphere. We present a statistical methodology in combination with an observing system for the detection and attribution of fugitive emissions of methane from distributed potential source location landscapes such as natural gas production sites. We measure long (> 500 m), integrated open-path concentrations of atmospheric methane using a dual frequency comb spectrometer and combine measurements with an atmospheric transport model to infer leak locations and strengths using a novel statistical method, the non-zero minimum bootstrap (NZMB). The new statistical method allows us to determine whether the empirical distribution of possible source strengths for a given location excludes zero. Using this information, we identify leaking source locations (i.e., natural gas wells) through rejection of the null hypothesis that the source is not leaking. The method is tested with a series of synthetic data inversions with varying measurement density and varying levels of model-data mismatch. It is also tested with field observations of (1) a non-leaking source location and (2) a source location where a controlled emission of 3.1 × 10-5 kg s-1 of methane gas is released over a period of several hours. This series of synthetic data tests and outdoor field observations using a controlled methane release demonstrates the viability of the approach for the detection and sizing of very small leaks of methane across large distances (4+ km2 in synthetic tests). The field tests demonstrate the ability to attribute small atmospheric enhancements of 17 ppb to the emitting source location against a background of combined atmospheric (e.g., background methane variability) and measurement uncertainty of 5 ppb (1σ), when measurements are averaged over 2 min. The results of the synthetic and field data testing show that the new observing system and statistical approach greatly decreases the incidence of false alarms (that is, wrongly identifying a well site to be leaking) compared with the same tests that do not use the NZMB approach and therefore offers increased leak detection and sizing capabilities.

  7. Research on the laser transmission characteristics simulation and comprehensive test in complex channel environment

    NASA Astrophysics Data System (ADS)

    Fu, Qiang; Liu, Jianhua; Wang, Xiaoman; Jiang, Huilin; Liu, Zhi

    2014-12-01

    The laser transmission characteristics affected in the complex channel environment, which limits the performance of laser equipment and engineering application severely. The article aim at the influence of laser transmission in atmospheric and seawater channels, summarizes the foreign researching work of the simulation and comprehensive test regarding to the laser transmission characteristics in complex environment. And researched the theory of atmospheric turbulence effect, water attenuation features, and put forward the corresponding theoretical model. And researched the simulate technology of atmospheric channel and sea water channel, put forward the analog device plan, adopt the similar theory of flowing to simulate the atmosphere turbulence .When the flowing has the same condition of geometric limits including the same Reynolds, they must be similar to each other in the motivation despite of the difference in the size, speed, and intrinsic quality. On this basis, set up a device for complex channel simulation and comprehensive testing, the overall design of the structure of the device, Hot and Cold Air Convection Simulation of Atmospheric Turbulence, mainly consists of cell body, heating systems, cooling systems, automatic control system. he simulator provides platform and method for the basic research of laser transmission characteristics in the domestic.

  8. Potential of temperature, controlled atmospheres, and ozone fumigation to control thrips and mealybugs on ornamental plants for export.

    PubMed

    Hollingsworth, Robert G; Armstrong, John W

    2005-04-01

    Ozone (O3) fumigation is a potential quarantine treatment alternative for controlling stored-product pests and surface insect pests on fresh agricultural commodities. We explored the effects of temperature, treatment time, controlled atmospheres, and vacuum in combination with O3 to control two important pests of ornamental crops: western flower thrips, Frankliniella occidentalis (Pergande), and longtailed mealybug, Pseudococcus longispinus Targioni Tozzetti. Treatment parameters tested were O3 concentrations from 0 to 3,800 ppm, treatment durations were from 30 to 120 min, vacuums were from 0 to 0.41 bar below ambient, temperatures were from 32.2 to 40.6 degrees C, and controlled atmospheres were composed primarily of nitrogen, carbon dioxide, or breathing air [BA]. Treatment efficacy was enhanced by higher O3 concentration and temperature, lower oxygen, and longer treatment times. Reduced pressure was not an important factor. Mealybugs were more difficult to kill than thrips. A 30-min treatment of O3 at approximately 200 ppm in 100% CO2 at 37.8 degrees C killed 47.9 and 98.0% of mealybugs and adult female thrips, respectively. All of the ornamentals tested were damaged to some degree by O3 treatments. However, crops with thick leaves such as orchids exhibited little damage, and the waxy portions of certain flowers were not damaged. The results suggest that O3 has potential as a quarantine treatment to control thrips and mealybugs on selected commodities.

  9. The resistance of the lichen Circinaria gyrosa (nom. provis.) towards simulated Mars conditions—a model test for the survival capacity of an eukaryotic extremophile

    NASA Astrophysics Data System (ADS)

    Sánchez, F. J.; Mateo-Martí, E.; Raggio, J.; Meeßen, J.; Martínez-Frías, J.; Sancho, L. G.a..; Ott, S.; de la Torre, R.

    2012-11-01

    The "Planetary Atmospheres and Surfaces Chamber" (PASC, at Centro de Astrobiología, INTA, Madrid) is able to simulate the atmosphere and surface temperature of most of the solar system planets. PASC is especially appropriate to study irradiation induced changes of geological, chemical, and biological samples under a wide range of controlled atmospheric and temperature conditions. Therefore, PASC is a valid method to test the resistance potential of extremophile organisms under diverse harsh conditions and thus assess the habitability of extraterrestrial environments. In the present study, we have investigated the resistance of a symbiotic organism under simulated Mars conditions, exemplified with the lichen Circinaria gyrosa - an extremophilic eukaryote. After 120 hours of exposure to simulated but representative Mars atmosphere, temperature, pressure and UV conditions; an unaltered photosynthetic performance demonstrated high resistance of the lichen photobiont.

  10. Development of a Test Facility for Air Revitalization Technology Evaluation

    NASA Technical Reports Server (NTRS)

    Lu, Sao-Dung; Lin, Amy; Campbell, Melissa; Smith, Frederick; Curley, Su

    2007-01-01

    Development of new air revitalization system (ARS) technology can initially be performed in a subscale laboratory environment, but in order to advance the maturity level, the technology must be tested in an end-to-end integrated environment. The Air Revitalization Technology Evaluation Facility (ARTEF) at the NASA Johnson Space Center serves as a ground test bed for evaluating emerging ARS technologies in an environment representative of spacecraft atmospheres. At the center of the ARTEF is a hypobaric chamber which serves as a sealed atmospheric chamber for closed loop testing. A Human Metabolic Simulator (HMS) was custom-built to simulate the consumption of oxygen, and production of carbon dioxide, moisture and heat of up to eight persons. A multitude of gas analyzers and dew point sensors are used to monitor the chamber atmosphere upstream and downstream of a test article. A robust vacuum system is needed to simulate the vacuum of space. A reliable data acquisition and control system is required to connect all the subsystems together. This paper presents the capabilities of the integrated test facility and some of the issues encountered during the integration.

  11. Genotoxicity Assessment of Chlorotrifluoroethylene Trimer Acid Using a Battery of In Vitro and In Vivo/In Vitro Assays

    DTIC Science & Technology

    1990-12-01

    in liquid nitrogen. Laboratory cultures were maintained as monolayers at 37 t 1.50C in a humidified atmosphere containing 5 t 1.5% CO2 and were... atmosphere containing 5% CO2. The cells were then washed twice with Dulbecco’s phosphate buffered saline (PBS) and incubated in F12 culture medium for six...time cell cultures ware treated with test or control material for 4 h at 37 t 1.SIA in a humidified atmosphere with 5% CO2 . After treatment, the

  12. Corrective Action Decision Document/Corrective Action Plan for Corrective Action Unit 104: Area 7 Yucca Flat Atmospheric Test Sites Nevada National Security Site, Nevada, Revision 0

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

    Patrick Matthews

    2012-10-01

    CAU 104 comprises the following corrective action sites (CASs): • 07-23-03, Atmospheric Test Site T-7C • 07-23-04, Atmospheric Test Site T7-1 • 07-23-05, Atmospheric Test Site • 07-23-06, Atmospheric Test Site T7-5a • 07-23-07, Atmospheric Test Site - Dog (T-S) • 07-23-08, Atmospheric Test Site - Baker (T-S) • 07-23-09, Atmospheric Test Site - Charlie (T-S) • 07-23-10, Atmospheric Test Site - Dixie • 07-23-11, Atmospheric Test Site - Dixie • 07-23-12, Atmospheric Test Site - Charlie (Bus) • 07-23-13, Atmospheric Test Site - Baker (Buster) • 07-23-14, Atmospheric Test Site - Ruth • 07-23-15, Atmospheric Test Site T7-4 •more » 07-23-16, Atmospheric Test Site B7-b • 07-23-17, Atmospheric Test Site - Climax These 15 CASs include releases from 30 atmospheric tests conducted in the approximately 1 square mile of CAU 104. Because releases associated with the CASs included in this CAU overlap and are not separate and distinguishable, these CASs are addressed jointly at the CAU level. The purpose of this CADD/CAP is to evaluate potential corrective action alternatives (CAAs), provide the rationale for the selection of recommended CAAs, and provide the plan for implementation of the recommended CAA for CAU 104. Corrective action investigation (CAI) activities were performed from October 4, 2011, through May 3, 2012, as set forth in the CAU 104 Corrective Action Investigation Plan.« less

  13. Atmospheric Probe Model: Construction and Wind Tunnel Tests

    NASA Technical Reports Server (NTRS)

    Vogel, Jerald M.

    1998-01-01

    The material contained in this document represents a summary of the results of a low speed wind tunnel test program to determine the performance of an atmospheric probe at low speed. The probe configuration tested consists of a 2/3 scale model constructed from a combination of hard maple wood and aluminum stock. The model design includes approximately 130 surface static pressure taps. Additional hardware incorporated in the baseline model provides a mechanism for simulating external and internal trailing edge split flaps for probe flow control. Test matrix parameters include probe side slip angle, external/internal split flap deflection angle, and trip strip applications. Test output database includes surface pressure distributions on both inner and outer annular wings and probe center line velocity distributions from forward probe to aft probe locations.

  14. Hyperbaric Oxygen Therapy in the Treatment of Chronic Mild-Moderate Blast-Induced Traumatic Brain Injury Post-Concussion Syndrome (PCS) and Post Traumatic Stress Disorder (PTSD)

    DTIC Science & Technology

    2017-10-01

    a randomized sham- controlled double-blind design with the sham- control group receiving slightly pressurized air at the beginning and end of each... controlled ( non -treatment, non -sham) single-arm crossover single-blind study. The scope of the project is to recruit, enroll, test, treat, re-test and...the P.I. conducted a non - controlled pilot trial of hyperbaric oxygen therapy (HBOT 1.5 atmospheres absolute/60 minutes, twice/day, 40 treatments

  15. 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.

  16. Surface hardening of Al alloys through controlled ball-milling and sintering.

    PubMed

    Kim, Seek Hyeoun; Kim, Yong Jin; Ahn, Jung-Ho

    2012-07-01

    One of the drawbacks of aluminum and its alloys is the lack of proper heat-treatment for surface-hardening. In the present work, a new and simple method of hardening the surface of aluminum and its alloys was developed. Low-energy ball-milling using specific process control agents (PCAs) was employed, using subsequent sintering in a controlled atmosphere. The PCAs in the present work were very effective both for milling and the formation of hard nanocrystalline dispersoids during sintering. The residual oxygen in a sintering atmosphere also played an important role in the formation of AIN or Al-O-N dispersoids. Through the proper control of the processing atmosphere and PCAs, the hardness and thickness of the hardened layers could be adjusted. The results of the wear test showed that the present aluminum alloys can be effectively utilized as light-weight components with a good wear resistance. Furthermore, the present method involves a simple forming process of die-compaction and sintering.

  17. Closed-Loop HIRF Experiments Performed on a Fault Tolerant Flight Control Computer

    NASA Technical Reports Server (NTRS)

    Belcastro, Celeste M.

    1997-01-01

    ABSTRACT Closed-loop HIRF experiments were performed on a fault tolerant flight control computer (FCC) at the NASA Langley Research Center. The FCC used in the experiments was a quad-redundant flight control computer executing B737 Autoland control laws. The FCC was placed in one of the mode-stirred reverberation chambers in the HIRF Laboratory and interfaced to a computer simulation of the B737 flight dynamics, engines, sensors, actuators, and atmosphere in the Closed-Loop Systems Laboratory. Disturbances to the aircraft associated with wind gusts and turbulence were simulated during tests. Electrical isolation between the FCC under test and the simulation computer was achieved via a fiber optic interface for the analog and discrete signals. Closed-loop operation of the FCC enabled flight dynamics and atmospheric disturbances affecting the aircraft to be represented during tests. Upset was induced in the FCC as a result of exposure to HIRF, and the effect of upset on the simulated flight of the aircraft was observed and recorded. This paper presents a description of these closed- loop HIRF experiments, upset data obtained from the FCC during these experiments, and closed-loop effects on the simulated flight of the aircraft.

  18. Solid amine development program

    NASA Technical Reports Server (NTRS)

    Lovell, J. S.

    1973-01-01

    A regenerable solid amine material to perform the functions of humidity control and CO2 removal for space shuttle type vehicle is reported. Both small scale and large scale testing have shown this material to be competitive, especially for the longer shuttle missions. However, it had been observed that the material off-gasses ammonia under certain conditions. This presents two concerns. The first, that the ammonia would contaminate the cabin atmosphere, and second, that the material is degrading with time. An extensive test program has shown HS-C to produce only trace quantities of atmospheric contaminants, and under normal extremes, to have no practical life limitation.

  19. A flight-test and simulation evaluation of the longitudinal final approach and landing performance of an automatic system for a light wing loading STOL aircraft equipped with wing spoilers

    NASA Technical Reports Server (NTRS)

    Brown, S. C.; Hardy, G. H.; Hindson, W. S.

    1984-01-01

    As part of a comprehensive flight-test investigation of short takeoff and landing (STOL) operating systems for the terminal systems for the terminal area, an automatic landing system has been developed and evaluated for a light wing-loading turboprop-powered aircraft. An advanced digital avionics system performed display, navigation, guidance, and control functions for the test aircraft. Control signals were generated in order to command powered actuators for all conventional controls and for a set of symmetrically driven wing spoilers. This report describes effects of the spoiler control on longitudinal autoland (automatic landing) performance. Flight-test results, with and without spoiler control, are presented and compared with available (basically, conventional takeoff and landing) performance criteria. These comparisons are augmented by results from a comprehensive simulation of the controlled aircraft that included representations of the microwave landing system navigation errors that were encountered in flight as well as expected variations in atmospheric turbulence and wind shear. Flight-test results show that the addition of spoiler control improves the touchdown performance of the automatic landing system. Spoilers improve longitudinal touchdown and landing pitch-attitude performance, particularly in tailwind conditions. Furthermore, simulation results indicate that performance would probably be satisfactory for a wider range of atmospheric disturbances than those encountered in flight. Flight results also indicate that the addition of spoiler control during the final approach does not result in any measurable change in glidepath track performance, and results in a very small deterioration in airspeed tracking. This difference contrasts with simulations results, which indicate some improvement in glidepath tracking and no appreciable change in airspeed tracking. The modeling problem in the simulation that contributed to this discrepancy with flight was not resolved.

  20. Statistical atmospheric inversion of local gas emissions by coupling the tracer release technique and local-scale transport modelling: a test case with controlled methane emissions

    NASA Astrophysics Data System (ADS)

    Ars, Sébastien; Broquet, Grégoire; Yver Kwok, Camille; Roustan, Yelva; Wu, Lin; Arzoumanian, Emmanuel; Bousquet, Philippe

    2017-12-01

    This study presents a new concept for estimating the pollutant emission rates of a site and its main facilities using a series of atmospheric measurements across the pollutant plumes. This concept combines the tracer release method, local-scale atmospheric transport modelling and a statistical atmospheric inversion approach. The conversion between the controlled emission and the measured atmospheric concentrations of the released tracer across the plume places valuable constraints on the atmospheric transport. This is used to optimise the configuration of the transport model parameters and the model uncertainty statistics in the inversion system. The emission rates of all sources are then inverted to optimise the match between the concentrations simulated with the transport model and the pollutants' measured atmospheric concentrations, accounting for the transport model uncertainty. In principle, by using atmospheric transport modelling, this concept does not strongly rely on the good colocation between the tracer and pollutant sources and can be used to monitor multiple sources within a single site, unlike the classical tracer release technique. The statistical inversion framework and the use of the tracer data for the configuration of the transport and inversion modelling systems should ensure that the transport modelling errors are correctly handled in the source estimation. The potential of this new concept is evaluated with a relatively simple practical implementation based on a Gaussian plume model and a series of inversions of controlled methane point sources using acetylene as a tracer gas. The experimental conditions are chosen so that they are suitable for the use of a Gaussian plume model to simulate the atmospheric transport. In these experiments, different configurations of methane and acetylene point source locations are tested to assess the efficiency of the method in comparison to the classic tracer release technique in coping with the distances between the different methane and acetylene sources. The results from these controlled experiments demonstrate that, when the targeted and tracer gases are not well collocated, this new approach provides a better estimate of the emission rates than the tracer release technique. As an example, the relative error between the estimated and actual emission rates is reduced from 32 % with the tracer release technique to 16 % with the combined approach in the case of a tracer located 60 m upwind of a single methane source. Further studies and more complex implementations with more advanced transport models and more advanced optimisations of their configuration will be required to generalise the applicability of the approach and strengthen its robustness.

  1. Piloted Simulator Tests of a Guidance System which Can Continously Predict Landing Point of a Low L/D Vehicle During Atmosphere Re-Entry

    NASA Technical Reports Server (NTRS)

    Wingrove, Rodney C.; Coate, Robert E.

    1961-01-01

    The guidance system for maneuvering vehicles within a planetary atmosphere which was studied uses the concept of fast continuous prediction of the maximum maneuver capability from existing conditions rather than a stored-trajectory technique. used, desired touchdown points are compared with the maximum range capability and heating or acceleration limits, so that a proper decision and choice of control inputs can be made by the pilot. In the method of display and control a piloted fixed simulator was used t o demonstrate the feasibility od the concept and to study its application to control of lunar mission reentries and recoveries from aborts.

  2. Effect of 1-Methylcyclopropene coupled with controlled atmosphere storage on the ripening and quality of ‘Cavendish’ bananas

    USDA-ARS?s Scientific Manuscript database

    Fresh-fruit banana is well known to have a short-life after harvest. A short pre-pilot study was carried out to test the effect of atmospheric condition exposure to 1-MCP on the quality, limited to cosmetic and peel appearance, and shelf life of fresh-fruit bananas. Low level of O2 (3 kPa) and high ...

  3. VANDENBERG AIR FORCE BASE, CALIF. - The SciSat-1 spacecraft is revealed at Vandenberg Air Force Base, Calif. Sci-Sat, which will undergo instrument checkout and spacecraft functional testing, weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

    NASA Image and Video Library

    2003-06-26

    VANDENBERG AIR FORCE BASE, CALIF. - The SciSat-1 spacecraft is revealed at Vandenberg Air Force Base, Calif. Sci-Sat, which will undergo instrument checkout and spacecraft functional testing, weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

  4. VANDENBERG AIR FORCE BASE, CALIF.- The cover is being lifted off SciSat-1 spacecraft at Vandenberg Air Force Base, Calif. Sci-Sat, which will undergo instrument checkout and spacecraft functional testing, weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

    NASA Image and Video Library

    2003-06-26

    VANDENBERG AIR FORCE BASE, CALIF.- The cover is being lifted off SciSat-1 spacecraft at Vandenberg Air Force Base, Calif. Sci-Sat, which will undergo instrument checkout and spacecraft functional testing, weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

  5. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... absence of H2S has been confirmed. Well-control fluid means drilling mud and completion or workover fluid... information such as geologic and geophysical data and correlations, well logs, formation tests, cores and... concentration in the atmosphere reaches 5 ppm; (20) Engineering controls to protect personnel from SO2; and (21...

  6. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... absence of H2S has been confirmed. Well-control fluid means drilling mud and completion or workover fluid... information such as geologic and geophysical data and correlations, well logs, formation tests, cores and... concentration in the atmosphere reaches 5 ppm; (20) Engineering controls to protect personnel from SO2; and (21...

  7. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... absence of H2S has been confirmed. Well-control fluid means drilling mud and completion or workover fluid... information such as geologic and geophysical data and correlations, well logs, formation tests, cores and... concentration in the atmosphere reaches 5 ppm; (20) Engineering controls to protect personnel from SO2; and (21...

  8. 30 CFR 250.490 - Hydrogen sulfide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... where neither the presence nor absence of H2S has been confirmed. Well-control fluid means drilling mud..., well logs, formation tests, cores and analysis of formation fluids; and (4) Submit a request for... initiate when the SO2 concentration in the atmosphere reaches 5 ppm; (20) Engineering controls to protect...

  9. Control algorithms for aerobraking in the Martian atmosphere

    NASA Technical Reports Server (NTRS)

    Ward, Donald T.; Shipley, Buford W., Jr.

    1991-01-01

    The Analytic Predictor Corrector (APC) and Energy Controller (EC) atmospheric guidance concepts were adapted to control an interplanetary vehicle aerobraking in the Martian atmosphere. Changes are made to the APC to improve its robustness to density variations. These changes include adaptation of a new exit phase algorithm, an adaptive transition velocity to initiate the exit phase, refinement of the reference dynamic pressure calculation and two improved density estimation techniques. The modified controller with the hybrid density estimation technique is called the Mars Hybrid Predictor Corrector (MHPC), while the modified controller with a polynomial density estimator is called the Mars Predictor Corrector (MPC). A Lyapunov Steepest Descent Controller (LSDC) is adapted to control the vehicle. The LSDC lacked robustness, so a Lyapunov tracking exit phase algorithm is developed to guide the vehicle along a reference trajectory. This algorithm, when using the hybrid density estimation technique to define the reference path, is called the Lyapunov Hybrid Tracking Controller (LHTC). With the polynomial density estimator used to define the reference trajectory, the algorithm is called the Lyapunov Tracking Controller (LTC). These four new controllers are tested using a six degree of freedom computer simulation to evaluate their robustness. The MHPC, MPC, LHTC, and LTC show dramatic improvements in robustness over the APC and EC.

  10. The Telesupervised Adaptive Ocean Sensor Fleet (TAOSF) Architecture: Coordination of Multiple Oceanic Robot Boats

    NASA Technical Reports Server (NTRS)

    Elfes, Alberto; Podnar, Gregg W.; Dolan, John M.; Stancliff, Stephen; Lin, Ellie; Hosler, Jeffrey C.; Ames, Troy J.; Higinbotham, John; Moisan, John R.; Moisan, Tiffany A.; hide

    2008-01-01

    Earth science research must bridge the gap between the atmosphere and the ocean to foster understanding of Earth s climate and ecology. Ocean sensing is typically done with satellites, buoys, and crewed research ships. The limitations of these systems include the fact that satellites are often blocked by cloud cover, and buoys and ships have spatial coverage limitations. This paper describes a multi-robot science exploration software architecture and system called the Telesupervised Adaptive Ocean Sensor Fleet (TAOSF). TAOSF supervises and coordinates a group of robotic boats, the OASIS platforms, to enable in-situ study of phenomena in the ocean/atmosphere interface, as well as on the ocean surface and sub-surface. The OASIS platforms are extended deployment autonomous ocean surface vehicles, whose development is funded separately by the National Oceanic and Atmospheric Administration (NOAA). TAOSF allows a human operator to effectively supervise and coordinate multiple robotic assets using a sliding autonomy control architecture, where the operating mode of the vessels ranges from autonomous control to teleoperated human control. TAOSF increases data-gathering effectiveness and science return while reducing demands on scientists for robotic asset tasking, control, and monitoring. The first field application chosen for TAOSF is the characterization of Harmful Algal Blooms (HABs). We discuss the overall TAOSF architecture, describe field tests conducted under controlled conditions using rhodamine dye as a HAB simulant, present initial results from these tests, and outline the next steps in the development of TAOSF.

  11. Investigation of toxicity and mutagenicity of cold atmospheric argon plasma.

    PubMed

    Maisch, T; Bosserhoff, A K; Unger, P; Heider, J; Shimizu, T; Zimmermann, J L; Morfill, G E; Landthaler, M; Karrer, S

    2017-04-01

    Cold atmospheric argon plasma is recognized as a new contact free approach for the decrease of bacterial load on chronic wounds in patients. So far very limited data are available on its toxicity and mutagenicity on eukaryotic cells. Thus, the toxic/mutagenic potential of cold atmospheric argon plasma using the MicroPlaSter β ® , which has been used efficiently in humans treating chronic and acute wounds, was investigated using the XTT assay in keratinocytes and fibroblasts and the HGPRT (hypoxanthine guanine phosphoribosyl transferase) assay with V79 Chinese hamster cells. The tested clinical parameter of a 2 min cold atmospheric argon plasma treatment revealed no relevant toxicity on keratinocytes (viability: 76% ± 0.17%) and on fibroblasts (viability: 81.8 ± 0.10) after 72 hr as compared to the untreated controls. No mutagenicity was detected in the HGPRT assay with V79 cells even after repetitive CAP treatments of 2-10 min every 24 hr for up to 5 days. In contrast, UV-C irradiation of V79 cells, used as a positive control in the HGPRT test, led to DNA damage and mutagenic effects. Our findings indicate that cold atmospheric plasma using the MicroPlaSter β ® shows negligible effects on keratinocytes and fibroblasts but no mutagenic potential in the HGPRT assay, indicating a new contact free safe technology. Environ. Mol. Mutagen. 58:172-177, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  12. 40 CFR 92.118 - Analyzer checks and calibrations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.118... sampling system at the sample probe or valve V2 at atmospheric pressure. Simultaneously, start the time...

  13. Testing a Regenerative Carbon Dioxide and Moisture Removal Technology

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.; Button, Amy; Sweterlitsch, Jeffrey J.; Curley, Suzanne

    2010-01-01

    The National Aeronautics and Space Administration supported the development of a new vacuum-desorbed regenerative carbon dioxide and humidity control technology for use in short duration human spacecraft. The technology was baselined for use in the Orion Crew Exploration Vehicle s Environmental Control and Life Support System (ECLSS). Termed the Carbon Dioxide And Moisture Removal Amine Swing-bed (CAMRAS), the unit was developed by Hamilton Sundstrand and has undergone extensive testing at Johnson Space Center. The tests were performed to evaluate performance characteristics under range of operating conditions and human loads expected in future spacecraft applications, as part of maturation to increase its readiness for flight. Early tests, conducted at nominal atmospheric pressure, used human metabolic simulators to generate loads, with later tests making us of human test subjects. During these tests many different test cases were performed, involving from 1 to 6 test subjects, with different activity profiles (sleep, nominal and exercise). These tests were conducted within the airlock portion of a human rated test chamber sized to simulate the Orion cabin free air volume. More recently, a test was completed that integrated the CAMRAS with a simulated suit loop using prototype umbilicals and was conducted at reduced atmospheric pressure and elevated oxygen levels. This paper will describe the facilities and procedures used to conduct these and future tests, and provide a summary of findings.

  14. 40 CFR Appendix A to Subpart Ddddd... - Methodology and Criteria for Demonstrating Eligibility for the Health-Based Compliance Alternatives

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... rate, type of control devices, process parameters (e.g., maximum heat input), and non-process... control systems (if applicable) and explain why the conditions are worst-case. (c) Number of test runs... located at the outlet of the control device and prior to any releases to the atmosphere. (e) Collection of...

  15. 40 CFR Appendix A to Subpart Ddddd... - Methodology and Criteria for Demonstrating Eligibility for the Health-Based Compliance Alternatives

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... rate, type of control devices, process parameters (e.g., maximum heat input), and non-process... control systems (if applicable) and explain why the conditions are worst-case. (c) Number of test runs... located at the outlet of the control device and prior to any releases to the atmosphere. (e) Collection of...

  16. 40 CFR Appendix A to Subpart Ddddd... - Methodology and Criteria for Demonstrating Eligibility for the Health-Based Compliance Alternatives

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... rate, type of control devices, process parameters (e.g., maximum heat input), and non-process... control systems (if applicable) and explain why the conditions are worst-case. (c) Number of test runs... located at the outlet of the control device and prior to any releases to the atmosphere. (e) Collection of...

  17. A Review of International Space Station Habitable Element Equipment Offgassing Characteristics

    NASA Technical Reports Server (NTRS)

    Perry, Jay L.

    2010-01-01

    Crewed spacecraft trace contaminant control employs both passive and active methods to achieve acceptable cabin atmospheric quality. Passive methods include carefully selecting materials of construction, employing clean manufacturing practices, and minimizing systems and payload operational impacts to the cabin environment. Materials selection and manufacturing processes constitute the first level of equipment offgassing control. An element-level equipment offgassing test provides preflight verification that passive controls have been successful. Offgassing test results from multiple International Space Station (ISS) habitable elements and cargo vehicles are summarized and implications for active contamination control equipment design are discussed

  18. Tensile strength of laser welded cobalt-chromium alloy with and without an argon atmosphere.

    PubMed

    Tartari, Anna; Clark, Robert K F; Juszczyk, Andrzej S; Radford, David R

    2010-06-01

    The tensile strength and depth of weld of two cobalt chromium alloys before and after laser welding with and without an argon gas atmosphere were investigated. Using two cobalt chromium alloys, rod shaped specimens (5 cm x 1.5 mm) were cast. Specimens were sand blasted, sectioned and welded with a pulsed Nd: YAG laser welding machine and tested in tension using an Instron universal testing machine. A statistically significant difference in tensile strength was observed between the two alloys. The tensile strength of specimens following laser welding was significantly less than the unwelded controls. Scanning electron microscopy showed that the micro-structure of the cast alloy was altered in the region of the weld. No statistically significant difference was found between specimens welded with or without an argon atmosphere.

  19. Atmospheric simulation using a liquid crystal wavefront-controlling device

    NASA Astrophysics Data System (ADS)

    Brooks, Matthew R.; Goda, Matthew E.

    2004-10-01

    Test and evaluation of laser warning devices is important due to the increased use of laser devices in aerial applications. This research consists of an atmospheric aberrating system to enable in-lab testing of various detectors and sensors. This system employs laser light at 632.8nm from a Helium-Neon source and a spatial light modulator (SLM) to cause phase changes using a birefringent liquid crystal material. Measuring outgoing radiation from the SLM using a CCD targetboard and Shack-Hartmann wavefront sensor reveals an acceptable resemblance of system output to expected atmospheric theory. Over three turbulence scenarios, an error analysis reveals that turbulence data matches theory. A wave optics computer simulation is created analogous to the lab-bench design. Phase data, intensity data, and a computer simulation affirm lab-bench results so that the aberrating SLM system can be operated confidently.

  20. Spin of Planetary Probes in Atmospheric Flight

    NASA Astrophysics Data System (ADS)

    Lorenz, R. D.

    Probes that enter planetary atmospheres are often spun during entry or descent for a variety of reasons. Their spin rate histories are influenced by often subtle effects. The spin requirements, control methods and flight experience from planetary and earth entry missions are reviewed. An interaction of the probe aerodynamic wake with a drogue parachute, observed in Gemini wind tunnel tests, is discussed in connection with the anomalous spin behaviour of the Huygens probe.

  1. Development of an experimental approach to study coupled soil-plant-atmosphere processes using plant analogs

    NASA Astrophysics Data System (ADS)

    Trautz, Andrew C.; Illangasekare, Tissa H.; Rodriguez-Iturbe, Ignacio; Heck, Katharina; Helmig, Rainer

    2017-04-01

    The atmosphere, soils, and vegetation near the land-atmosphere interface are in a state of continuous dynamic interaction via a myriad of complex interrelated feedback processes which collectively, remain poorly understood. Studying the fundamental nature and dynamics of such processes in atmospheric, ecological, and/or hydrological contexts in the field setting presents many challenges; current experimental approaches are an important factor given a general lack of control and high measurement uncertainty. In an effort to address these issues and reduce overall complexity, new experimental design considerations (two-dimensional intermediate-scale coupled wind tunnel-synthetic aquifer testing using synthetic plants) for studying soil-plant-atmosphere continuum soil moisture dynamics are introduced and tested in this study. Validation of these experimental considerations, particularly the adoption of synthetic plants, is required prior to their application in future research. A comparison of three experiments with bare soil surfaces or transplanted with a Stargazer lily/limestone block was used to evaluate the feasibility of the proposed approaches. Results demonstrate that coupled wind tunnel-porous media experimentation, used to simulate field conditions, reduces complexity, and enhances control while allowing fine spatial-temporal resolution measurements to be made using state-of-the-art technologies. Synthetic plants further help reduce system complexity (e.g., airflow) while preserving the basic hydrodynamic functions of plants (e.g., water uptake and transpiration). The trends and distributions of key measured atmospheric and subsurface spatial and temporal variables (e.g., soil moisture, relative humidity, temperature, air velocity) were comparable, showing that synthetic plants can be used as simple, idealized, nonbiological analogs for living vegetation in fundamental hydrodynamic studies.

  2. Advancement of Optical Component Control for an Imaging Fabry-Perot Interferometer

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Cook, William B.; Flood, Michael A.; Campbell, Joel F.; Boyer, Charles M.

    2009-01-01

    Risk mitigation activities associated with a prototype imaging Fabry-Perot Interferometer (FPI) system are continuing at the NASA Langley Research Center. The system concept and technology center about enabling and improving future space-based atmospheric composition missions, with a current focus on observing tropospheric ozone around 9.6 micron, while having applicability toward measurement in different spectral regions and other applications. Recent activities have focused on improving an optical element control subsystem to enable precise and accurate positioning and control of etalon plates; this is needed to provide high system spectral fidelity critical for enabling the required ability to spectrally-resolve atmospheric line structure. The latest results pertaining to methodology enhancements, system implementation, and laboratory characterization testing will be reported

  3. Quality Detection of Litchi Stored in Different Environments Using an Electronic Nose

    PubMed Central

    Xu, Sai; Lü, Enli; Lu, Huazhong; Zhou, Zhiyan; Wang, Yu; Yang, Jing; Wang, Yajuan

    2016-01-01

    The purpose of this paper was to explore the utility of an electronic nose to detect the quality of litchi fruit stored in different environments. In this study, a PEN3 electronic nose was adopted to test the storage time and hardness of litchi that were stored in three different types of environment (room temperature, refrigerator and controlled-atmosphere). After acquiring data about the hardness of the sample and from the electronic nose, linear discriminant analysis (LDA), canonical correlation analysis (CCA), BP neural network (BPNN) and BP neural network-partial least squares regression (BPNN-PLSR), were employed for data processing. The experimental results showed that the hardness of litchi fruits stored in all three environments decreased during storage. The litchi stored at room temperature had the fastest rate of decrease in hardness, followed by those stored in a refrigerator environment and under a controlled-atmosphere. LDA has a poor ability to classify the storage time of the three environments in which litchi was stored. BPNN can effectively recognize the storage time of litchi stored in a refrigerator and a controlled-atmosphere environment. However, the BPNN classification of the effect of room temperature storage on litchi was poor. CCA results show a significant correlation between electronic nose data and hardness data under the room temperature, and the correlation is more obvious for those under the refrigerator environment and controlled-atmosphere environment. The BPNN-PLSR can effectively predict the hardness of litchi under refrigerator storage conditions and a controlled-atmosphere environment. However, the BPNN-PLSR prediction of the effect of room temperature storage on litchi and global environment storage on litchi were poor. Thus, this experiment proved that an electronic nose can detect the quality of litchi under refrigeratored storage and a controlled-atmosphere environment. These results provide a useful reference for future studies on nondestructive and intelligent monitoring of fruit quality. PMID:27338391

  4. Flight Simulation of ARES in the Mars Environment

    NASA Technical Reports Server (NTRS)

    Kenney, P. Sean; Croom, Mark A.

    2011-01-01

    A report discusses using the Aerial Regional- scale Environmental Survey (ARES) light airplane as an observation platform on Mars in order to gather data. It would have to survive insertion into the atmosphere, fly long enough to meet science objectives, and provide a stable platform. The feasibility of such a platform was tested using the Langley Standard Real- Time Simulation in C++. The unique features of LaSRS++ are: full, six-degrees- of-freedom flight simulation that can be used to evaluate the performance of the aircraft in the Martian environment; capability of flight analysis from start to finish; support of Monte Carlo analysis of aircraft performance; and accepting initial conditions from POST results for the entry and deployment of the entry body. Starting with a general aviation model, the design was tweaked to maintain a stable aircraft under expected Martian conditions. Outer mold lines were adjusted based on experience with the Martian atmosphere. Flight control was modified from a vertical acceleration control law to an angle-of-attack control law. Navigation was modified from a vertical acceleration control system to an alpha control system. In general, a pattern of starting with simple models with well-understood behaviors was selected and modified during testing.

  5. VANDENBERG AIR FORCE BASE, CALIF.- At Vandenberg Air Force Base, Calif., spacecraft functional testing is underway on the SciSat-1. The solar arrays are being attached and the communications systems are also being checked out. The SciSat-1 weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

    NASA Image and Video Library

    2003-07-12

    VANDENBERG AIR FORCE BASE, CALIF.- At Vandenberg Air Force Base, Calif., spacecraft functional testing is underway on the SciSat-1. The solar arrays are being attached and the communications systems are also being checked out. The SciSat-1 weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

  6. VANDENBERG AIR FORCE BASE, CALIF.- A covered SciSat-1 spacecraft sits on a test stand at Vandenberg Air Force Base, Calif. The solar arrays will be attached and the communications systems checked out. The SciSat-1 weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

    NASA Image and Video Library

    2003-07-29

    VANDENBERG AIR FORCE BASE, CALIF.- A covered SciSat-1 spacecraft sits on a test stand at Vandenberg Air Force Base, Calif. The solar arrays will be attached and the communications systems checked out. The SciSat-1 weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

  7. Effects of Topography-based Subgrid Structures on Land Surface Modeling

    NASA Astrophysics Data System (ADS)

    Tesfa, T. K.; Ruby, L.; Brunke, M.; Thornton, P. E.; Zeng, X.; Ghan, S. J.

    2017-12-01

    Topography has major control on land surface processes through its influence on atmospheric forcing, soil and vegetation properties, network topology and drainage area. Consequently, accurate climate and land surface simulations in mountainous regions cannot be achieved without considering the effects of topographic spatial heterogeneity. To test a computationally less expensive hyper-resolution land surface modeling approach, we developed topography-based landunits within a hierarchical subgrid spatial structure to improve representation of land surface processes in the ACME Land Model (ALM) with minimal increase in computational demand, while improving the ability to capture the spatial heterogeneity of atmospheric forcing and land cover influenced by topography. This study focuses on evaluation of the impacts of the new spatial structures on modeling land surface processes. As a first step, we compare ALM simulations with and without subgrid topography and driven by grid cell mean atmospheric forcing to isolate the impacts of the subgrid topography on the simulated land surface states and fluxes. Recognizing that subgrid topography also has important effects on atmospheric processes that control temperature, radiation, and precipitation, methods are being developed to downscale atmospheric forcings. Hence in the second step, the impacts of the subgrid topographic structure on land surface modeling will be evaluated by including spatial downscaling of the atmospheric forcings. Preliminary results on the atmospheric downscaling and the effects of the new spatial structures on the ALM simulations will be presented.

  8. Infrasound data inversion for atmospheric sounding

    NASA Astrophysics Data System (ADS)

    Lalande, J.-M.; Sèbe, O.; Landès, M.; Blanc-Benon, Ph.; Matoza, R. S.; Le Pichon, A.; Blanc, E.

    2012-07-01

    The International Monitoring System (IMS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) continuously records acoustic waves in the 0.01-10 Hz frequency band, known as infrasound. These waves propagate through the layered structure of the atmosphere. Coherent infrasonic waves are produced by a variety of anthropogenic and natural sources and their propagation is controlled by spatiotemporal variations of temperature and wind velocity. Natural stratification of atmospheric properties (e.g. temperature, density and winds) forms waveguides, allowing long-range propagation of infrasound waves. However, atmospheric specifications used in infrasound propagation modelling suffer from lack and sparsity of available data above an altitude of 50 km. As infrasound can propagate in the upper atmosphere up to 120 km, we assume that infrasonic data could be used for sounding the atmosphere, analogous to the use of seismic data to infer solid Earth structure and the use of hydroacoustic data to infer oceanic structure. We therefore develop an inversion scheme for vertical atmospheric wind profiles in the framework of an iterative linear inversion. The forward problem is treated in the high-frequency approximation using a Hamiltonian formulation and complete first-order ray perturbation theory is developed to construct the Fréchet derivatives matrix. We introduce a specific parametrization for the unknown model parameters based on Principal Component Analysis. Finally, our algorithm is tested on synthetic data cases spanning different seasonal periods and network configurations. The results show that our approach is suitable for infrasound atmospheric sounding on a regional scale.

  9. Bacillus subtilis spores on artificial meteorites survive hypervelocity atmospheric entry: implications for Lithopanspermia.

    PubMed

    Fajardo-Cavazos, Patricia; Link, Lindsey; Melosh, H Jay; Nicholson, Wayne L

    2005-12-01

    An important but untested aspect of the lithopanspermia hypothesis is that microbes situated on or within meteorites could survive hypervelocity entry from space through Earth's atmosphere. The use of high-altitude sounding rockets to test this notion was explored. Granite samples permeated with spores of Bacillus subtilis strain WN511 were attached to the exterior telemetry module of a sounding rocket and launched from White Sands Missile Range, New Mexico into space, reaching maximum atmospheric entry velocity of 1.2 km/s. Maximum recorded temperature during the flight was measured at 145 degrees C. The surfaces of the post-flight granite samples were swabbed and tested for recovery and survival of WN511 spores, using genetic markers and the unique DNA fingerprint of WN511 as recovery criteria. Spore survivors were isolated at high frequency, ranging from 1.2% to 4.4% compared with ground controls, from all surfaces except the forward-facing surface. Sporulation-defective mutants were noted among the spaceflight survivors at high frequency (4%). These experiments constitute the first report of spore survival to hypervelocity atmospheric transit, and indicate that sounding rocket flights can be used to model the high-speed atmospheric entry of bacteria-laden artificial meteorites.

  10. Bacillus subtilis Spores on Artificial Meteorites Survive Hypervelocity Atmospheric Entry: Implications for Lithopanspermia

    NASA Astrophysics Data System (ADS)

    Fajardo-Cavazos, Patricia; Link, Lindsey; Melosh, H. Jay; Nicholson, Wayne L.

    2005-12-01

    An important but untested aspect of the lithopanspermia hypothesis is that microbes situated on or within meteorites could survive hypervelocity entry from space through Earth's atmosphere. The use of high-altitude sounding rockets to test this notion was explored. Granite samples permeated with spores of Bacillus subtilis strain WN511 were attached to the exterior telemetry module of a sounding rocket and launched from White Sands Missile Range, New Mexico into space, reaching maximum atmospheric entry velocity of 1.2 km/s. Maximum recorded temperature during the flight was measured at 145°C. The surfaces of the post-flight granite samples were swabbed and tested for recovery and survival of WN511 spores, using genetic markers and the unique DNA fingerprint of WN511 as recovery criteria. Spore survivors were isolated at high frequency, ranging from 1.2% to 4.4% compared with ground controls, from all surfaces except the forward-facing surface. Sporulation-defective mutants were noted among the spaceflight survivors at high frequency (4%). These experiments constitute the first report of spore survival to hypervelocity atmospheric transit, and indicate that sounding rocket flights can be used to model the high-speed atmospheric entry of bacteria-laden artificial meteorites.

  11. Control of Surface Attack by Gallium Alloys in Electrical Contacts.

    DTIC Science & Technology

    1986-03-28

    and atmospheric control but does not allow visual observation of the contact brushes. This machine is a small homopolar motor built from mild steel...collectors,gallium, homopolar devices,liquid metals,~- is. ABSTRACT ICNI.. .. w 41N"w -~dv.mp.d Wrllt by Itabata" * Electrical contact between a copp’er...32 5 Test rig with felt metal brushes 32 6 Homopolar test apparatus 33 7 Rewetting of alloy track 33 8 Alloy track after running with finger 34 brushes

  12. Atmosphere behavior in gas-closed mouse-algal systems - An experimental and modelling study

    NASA Technical Reports Server (NTRS)

    Averner, M. M.; Moore, B., III; Bartholomew, I.; Wharton, R.

    1984-01-01

    A NASA-sponsored research program initiated using mathematical modelling and laboratory experimentation aimed at examining the gas-exchange characteristics of artificial animal/plant systems closed to the ambient atmosphere is studied. The development of control techniques and management strategies for maintaining the atmospheric levels of carbon dioxide and oxygen at physiological levels is considered. A mathematical model simulating the behavior of a gas-closed mouse-algal system under varying environmental conditions is described. To verify and validate the model simulations, an analytical system with which algal growth and gas exchange characteristics can be manipulated and measured is designed, fabricated, and tested. The preliminary results are presented.

  13. Functional Performance of an Enabling Atmosphere Revitalization Subsystem Architecture for Deep Space Exploration Missions

    NASA Technical Reports Server (NTRS)

    Perry, Jay L.; Abney, Morgan B.; Frederick, Kenneth R.; Greenwood, Zachary W.; Kayatin, Matthew J.; Newton, Robert L.; Parrish, Keith J.; Roman, Monsi C.; Takada, Kevin C.; Miller, Lee A.; hide

    2013-01-01

    A subsystem architecture derived from the International Space Station's (ISS) Atmosphere Revitalization Subsystem (ARS) has been functionally demonstrated. This ISS-derived architecture features re-arranged unit operations for trace contaminant control and carbon dioxide removal functions, a methane purification component as a precursor to enhance resource recovery over ISS capability, operational modifications to a water electrolysis-based oxygen generation assembly, and an alternative major atmospheric constituent monitoring concept. Results from this functional demonstration are summarized and compared to the performance observed during ground-based testing conducted on an ISS-like subsystem architecture. Considerations for further subsystem architecture and process technology development are discussed.

  14. Newtonian CAFE: a new ideal MHD code to study the solar atmosphere

    NASA Astrophysics Data System (ADS)

    González, J. J.; Guzmán, F.

    2015-12-01

    In this work we present a new independent code designed to solve the equations of classical ideal magnetohydrodynamics (MHD) in three dimensions, submitted to a constant gravitational field. The purpose of the code centers on the analysis of solar phenomena within the photosphere-corona region. In special the code is capable to simulate the propagation of impulsively generated linear and non-linear MHD waves in the non-isothermal solar atmosphere. We present 1D and 2D standard tests to demonstrate the quality of the numerical results obtained with our code. As 3D tests we present the propagation of MHD-gravity waves and vortices in the solar atmosphere. The code is based on high-resolution shock-capturing methods, uses the HLLE flux formula combined with Minmod, MC and WENO5 reconstructors. The divergence free magnetic field constraint is controlled using the Flux Constrained Transport method.

  15. MetNH3: Metrology for ammonia in ambient air

    NASA Astrophysics Data System (ADS)

    Braban, Christine; Twigg, Marsailidh; Tang, Sim; Leuenberger, Daiana; Ferracci, Valerio; Martin, Nick; Pascale, Celine; Hieta, Tuomas; Pogany, Andrea; Persijn, Stefan; van Wijk, Janneke; Gerwig, Holger; Wirtze, Klaus; Tiebe, Carlo; Balslev-Harder, David; Niederhausen, Bernhardt

    2015-04-01

    Measuring ammonia in ambient air is a sensitive and priority issue due to its harmful effects on human health and ecosystems. The European Directive 2001/81/EC on 'National Emission Ceilings for Certain Atmospheric Pollutants (NEC)' regulates ammonia emissions in the member states. However, there is a lack of regulation to ensure reliable ammonia measurements namely in applicable analytical technology, maximum allowed uncertainty, quality assurance and quality control (QC/QA) procedures as well as in the infrastructure to attain metrological traceability. Validated ammonia measurement data of high quality from air monitoring networks are vitally important for identifying changes due to implementations of environment policies, for understanding where the uncertainties in current emission inventories are derived from and for providing independent verification of atmospheric model predictions. The new EURAMET project MetNH3 aims to develop improved reference gas mixtures by static and dynamic gravimetric generation methods, develop and characterise laser based optical spectrometric standards and establish the transfer from high-accuracy standards to field applicable methods. MetNH3started in June 2014 and in this presentation the first results from the metrological characterisation of a commercially available cavity ring-down spectrometer (CRDS) will be discussed. Also first tests and results from a new design, Controlled Atmosphere Test Facility (CATFAC), which is to be characterised and used to validate the performance of diffusive samplers, denuders and on-line instruments, will be reported. CAFTEC can be used to control test parameters such as ammonia concentration, relative humidity and wind speed. Outline plans for international laboratory and field intercomparisons in 2016 will be presented.

  16. Addendum report to atmospheric science facility pallet-only mode space transportation system payload feasibility study, volume 3, revision A

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The feasibility of accomplishing selected atmospheric science mission using a pallet-only mode was studied. Certain unresolved issues were identified. The first issue was that of assuring that the on-board computer facility was adequate to process scientific data, control subsystems such as instrument pointing, provide mission operational program capability, and accomplish display and control. The second issue evolved from an investigation of the availability of existing substitute instruments that could be used instead of the prime instrumentation where the development tests and schedules are incompatible with the realistic budgets and shuttle vehicle schedules. Some effort was expended on identifying candidate substitute instruments, and the performance, cost, and development schedule trade-offs found during that effort were significant enough to warrant a follow-on investigation. This addendum documents the results of that follow-on effort, as it applies to the Atmospheric Sciences Facility.

  17. Development and Testing of a Sorbent-Based Atmosphere Revitalization System 2010/2011

    NASA Technical Reports Server (NTRS)

    Miller, Lee A.; Knox, James C.

    2012-01-01

    Spacecraft being developed for future exploration missions incorporate Environmental Control and Life Support Systems (ECLSS) that limit weight, power, and volume thus requiring systems with higher levels of efficiency while maintaining high dependability and robustness. For air revitalization, an approach that meets those goals utilizes a regenerative Vacuum-Swing Adsorption (VSA) system that removes 100% of the CO2 from the cabin atmosphere as well as 100% of the water. A Sorbent Based Atmosphere Revitalization (SBAR) system is a VSA system that utilizes standard commercial adsorbents that have been proven effective and safe in spacecraft including Skylab and the International Space Station. The SBAR system is the subject of a development, test, and evaluation program that is being conducted at NASA s Marshall Space Flight Center. While previous testing had validated that the technology is a viable option, potential improvements to system design and operation were identified. Modifications of the full-scale SBAR test articles and adsorption cycles have been implemented and have shown significant performance gains resulting in a decrease in the consumables required for a mission as well as improved mission safety. Previous testing had utilized single bed test articles, during this period the test facility was enhanced to allow testing on the full 2-bed SBAR system. The test facility simulates a spacecraft ECLSS and allows testing of the SBAR system over the full range of operational conditions using mission simulations that assess the real-time performance of the SBAR system during scenarios that include the metabolic transients associated with extravehicular activity. Although future manned missions are currently being redefined, the atmosphere revitalization requirements for the spacecraft are expected to be quite similar to the Orion and the Altair vehicles and the SBAR test program addressed validation to the defined mission requirements as well as operation in other potential vehicle architectures. The development program, including test articles, the test facility, and tests and results through early 2011 is discussed.

  18. Closure Report for Corrective Action Unit 104: Area 7 Yucca Flat Atmospheric Test Sites, Nevada National Security Site, Nevada

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

    None

    2013-06-27

    This Closure Report (CR) presents information supporting closure of Corrective Action Unit (CAU) 104, Area 7 Yucca Flat Atmospheric Test Sites, and provides documentation supporting the completed corrective actions and confirmation that closure objectives for CAU 104 were met. This CR complies with the requirements of the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the State of Nevada; the U.S. Department of Energy (DOE), Environmental Management; the U.S. Department of Defense; and DOE, Legacy Management. CAU 104 consists of the following 15 Corrective Action Sites (CASs), located in Area 7 of the Nevada National Securitymore » Site: · CAS 07-23-03, Atmospheric Test Site T-7C · CAS 07-23-04, Atmospheric Test Site T7-1 · CAS 07-23-05, Atmospheric Test Site · CAS 07-23-06, Atmospheric Test Site T7-5a · CAS 07-23-07, Atmospheric Test Site - Dog (T-S) · CAS 07-23-08, Atmospheric Test Site - Baker (T-S) · CAS 07-23-09, Atmospheric Test Site - Charlie (T-S) · CAS 07-23-10, Atmospheric Test Site - Dixie · CAS 07-23-11, Atmospheric Test Site - Dixie · CAS 07-23-12, Atmospheric Test Site - Charlie (Bus) · CAS 07-23-13, Atmospheric Test Site - Baker (Buster) · CAS 07-23-14, Atmospheric Test Site - Ruth · CAS 07-23-15, Atmospheric Test Site T7-4 · CAS 07-23-16, Atmospheric Test Site B7-b · CAS 07-23-17, Atmospheric Test Site - Climax Closure activities began in October 2012 and were completed in April 2013. Activities were conducted according to the Corrective Action Decision Document/Corrective Action Plan for CAU 104. The corrective actions included No Further Action and Clean Closure. Closure activities generated sanitary waste, mixed waste, and recyclable material. Some wastes exceeded land disposal limits and required treatment prior to disposal. Other wastes met land disposal restrictions and were disposed in appropriate onsite landfills. The U.S. Department of Energy, National Nuclear Security Administration Nevada Field Office (NNSA/NFO) requests the following: · A Notice of Completion from the Nevada Division of Environmental Protection to NNSA/NFO for closure of CAU 104 · The transfer of CAU 104 from Appendix III to Appendix IV, Closed Corrective Action Units, of the FFACO« less

  19. Corrosion and Durability Research | Concentrating Solar Power | NREL

    Science.gov Websites

    -change techniques. Controlled testing can be performed under a range of conditions, such as: different atmospheres, different temperatures (from room temperature up to 1,400°C), thermal cycling, and different

  20. 49 CFR 192.481 - Atmospheric corrosion control: Monitoring.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Atmospheric corrosion control: Monitoring. 192.481... Control § 192.481 Atmospheric corrosion control: Monitoring. (a) Each operator must inspect each pipeline or portion of pipeline that is exposed to the atmosphere for evidence of atmospheric corrosion, as...

  1. 49 CFR 192.481 - Atmospheric corrosion control: Monitoring.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Atmospheric corrosion control: Monitoring. 192.481... Control § 192.481 Atmospheric corrosion control: Monitoring. (a) Each operator must inspect each pipeline or portion of pipeline that is exposed to the atmosphere for evidence of atmospheric corrosion, as...

  2. 49 CFR 192.481 - Atmospheric corrosion control: Monitoring.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Atmospheric corrosion control: Monitoring. 192.481... Control § 192.481 Atmospheric corrosion control: Monitoring. (a) Each operator must inspect each pipeline or portion of pipeline that is exposed to the atmosphere for evidence of atmospheric corrosion, as...

  3. The balloon-borne exoplanet spectroscopy experiment (BETSE)

    NASA Astrophysics Data System (ADS)

    Pascale, E.

    2015-10-01

    The balloon-borne exoplanet spectroscopy experiment (BETSE) is a proposed balloon spectrometer operating in the 1-5 μm band with spectral resolution of R = 100. Using a 50 cm diameter telescope, BETSE is desgnied to have sufficient sensitivity and control of systematics to measure the atmospheric spectra of representative sample of known hot Jupiters, few warm Neptunes, and some of the exoplanets TESS will soon begin to discover. This would for the first time allow us to place strict observational constraints on the nature of exo-atmospheres and on models of planetary formation. In a LDB flight from Antarctica, BETSE would be able to characterize the atmospheres of 20 planets. If a ULDB flight is available, the combination of a longer flight and night time operations would enable BETSE to ground-breakingly characterize the atmospheres of more than 40 planets. Prior to an LDB or ULDB flight, BETSE would be tested in a 24 hr flight from Fort Sumner, NM, in order to test all subsystems, also observing more than 4 planets with SNR greater than 5.

  4. Digital temperature and velocity control of mach 0.3 atmospheric pressure durability testing burner rigs in long time, unattended cyclic testing

    NASA Technical Reports Server (NTRS)

    Deadmore, D. L.

    1985-01-01

    Hardware and software were developed to implement the hybrid digital control of two Jet A-1 fueled Mach 0.3 burners from startup to completion of a preset number of hot corrosion flame durability cycle tests of materials at 1652 F. This was accomplished by use of a basic language programmable microcomputer and data aquisition and control unit connected together by the IEEE-488 Bus. The absolute specimen temperature was controlled to + or - 3 F by use of digital adjustment of the fuel flow using a P-I-D (Proportional-Integral-Derivative) control algorithm. The specimen temperature was within + or - 2 F of the set point more than 90 percent of the time. Pressure control was achieved by digital adjustment of the combustion air flow using a proportional control algorithm. The burner pressure was controlled at 1.0 + or - 0.02 psig. Logic schemes were incorporated into the system to protect the test specimen from abnormal test conditions in the event of a hardware of software malfunction.

  5. Halon Replacement Program for Aviation, Aircraft Engine Nacelle Application Phase II - Operational Comparison of Selected Extinguishants

    DTIC Science & Technology

    1997-05-01

    Control Butterfly Hi-Pressure High Flow Control Butterfly Ejector Primary Clycol Control Valve Scrubber Fan Pressure Control Butterfly 8" Venturi ...the scrubber . 20 ■ SCRUBBER FAN BLOWER INLET VALVE VP-2 VP-3 VP-4 VP-5 VP-6 VP-7 VP-8 VP-9 VP-10 SV-1 SV-2 DESCRIPTION Atmospheric...Blower Bypass Butterfly 24" Venturi Control Butterfly 24" Test Section Exit Butterfly Ejector 10’ Secondary Inlet-Butterfly Hi-pressure Low Flow

  6. Effect of ozone on penicillium mold decay and sporulation

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

    Harding, P.R. Jr.

    1968-03-01

    Tests were run with ozone in the atmosphere of storage rooms that contained oranges and lemons in open wooden storage boxes and in fiberboard cartons. Excellent control of sporulation and some control of decay by Penicillium molds resulted in the open storage boxes with ozone at the 1.0 ppm level, but little control of sporulation and no control of decay resulted in vented cartons held in this concentration. Ozone gave no control of sporulation or decay in nonvented cartons. 6 references, 3 tables.

  7. Study program for encapsulation materials interface for low cost silicon solar array

    NASA Technical Reports Server (NTRS)

    Kaelble, D. H.; Mansfeld, F. B.; Lunsden, J. B., III; Leung, C.

    1980-01-01

    An atmospheric corrosion model was developed and verified by five months of corrosion rate and climatology data acquired at the Mead, Nebraska LSA test site. Atmospheric corrosion rate monitors (ACM) show that moisture condensation probability and ionic conduction at the corroding surface or interface are controlling factors in corrosion rate. Protection of the corroding surface by encapsulant was shown by the ACM recordings to be maintained, independent of climatology, over the five months outdoor exposure period. The macroscopic corrosion processes which occur at Mead are shown to be reproduced in the climatology simulator. Controlled experiments with identical moisture and temperature aging cycles show that UV radiation causes corrosion while UV shielding inhibits LSA corrosion.

  8. LADEE Satellite Modeling and Simulation Development

    NASA Technical Reports Server (NTRS)

    Adams, Michael; Cannon, Howard; Frost, Chad

    2011-01-01

    As human activity on and around the Moon increases, so does the likelihood that our actions will have an impact on its atmosphere. The Lunar Atmosphere and Dust Environment Explorer (LADEE), a NASA satellite scheduled to launch in 2013, will orbit the Moon collecting composition, density, and time variability data to characterize the current state of the lunar atmosphere. LADEE will also test the concept of the "Modular Common Bus" spacecraft architecture, an effort to reduce both development time and cost by designing reusable, modular components for use in multiple missions with similar requirements. An important aspect of this design strategy is to both simulate the spacecraft and develop the flight code in Simulink, a block diagram-style programming language that allows easy algorithm visualization and performance testing. Before flight code can be tested, however, a realistic simulation of the satellite and its dynamics must be generated and validated. This includes all of the satellite control system components such as actuators used for force and torque generation and sensors used for inertial orientation reference. My primary responsibilities have included designing, integrating, and testing models for the LADEE thrusters, reaction wheels, star trackers, and rate gyroscopes.

  9. Space Shuttle stability and control flight test techniques

    NASA Technical Reports Server (NTRS)

    Cooke, D. R.

    1980-01-01

    A unique approach for obtaining vehicle aerodynamic characteristics during entry has been developed for the Space Shuttle. This is due to the high cost of Shuttle testing, the need to open constraints for operational flights, and the fact that all flight regimes are flown starting with the first flight. Because of uncertainties associated with predicted aerodynamic coefficients, nine flight conditions have been identified at which control problems could occur. A detailed test plan has been developed for testing at these conditions and is presented. Due to limited testing, precise computer initiated maneuvers are implemented. These maneuvers are designed to optimize the vehicle motion for determining aerodynamic coefficients. Special sensors and atmospheric measurements are required to provide stability and control flight data during an entire entry. The techniques employed in data reduction are proven programs developed and used at NASA/DFRC.

  10. IMPROVED CORROSION RESISTANCE OF ALUMINA REFRACTORIES

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

    John P. Hurley; Patty L. Kleven

    2001-09-30

    The initial objective of this project was to do a literature search to define the problems of refractory selection in the metals and glass industries. The problems fall into three categories: Economic--What do the major problems cost the industries financially? Operational--How do the major problems affect production efficiency and impact the environment? and Scientific--What are the chemical and physical mechanisms that cause the problems to occur? This report presents a summary of these problems. It was used to determine the areas in which the EERC can provide the most assistance through bench-scale and laboratory testing. The final objective of thismore » project was to design and build a bench-scale high-temperature controlled atmosphere dynamic corrosion application furnace (CADCAF). The furnace will be used to evaluate refractory test samples in the presence of flowing corrodents for extended periods, to temperatures of 1600 C under controlled atmospheres. Corrodents will include molten slag, steel, and glass. This test should prove useful for the glass and steel industries when faced with the decision of choosing the best refractory for flowing corrodent conditions.« less

  11. 40 CFR 53.22 - Generation of test atmospheres.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... test concentration shall be verified. (b) The test atmosphere delivery system shall be designed and... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2...

  12. 40 CFR 53.22 - Generation of test atmospheres.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... test concentration shall be verified. (b) The test atmosphere delivery system shall be designed and... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2...

  13. Plutonium in the atmosphere: A global perspective.

    PubMed

    Thakur, P; Khaing, H; Salminen-Paatero, S

    2017-09-01

    A number of potential source terms have contributed plutonium isotopes to the atmosphere. The atmospheric nuclear weapon tests conducted between 1945 and 1980 and the re-entry of the burned SNAP-9A satellite in 1964, respectively. It is generally believed that current levels of plutonium in the stratosphere are negligible and compared with the levels generally found at surface-level air. In this study, the time trend analysis and long-term behavior of plutonium isotopes ( 239+240 Pu and 238 Pu) in the atmosphere were assessed using historical data collected by various national and international monitoring networks since 1960s. An analysis of historical data indicates that 239+240 Pu concentration post-1984 is still frequently detectable, whereas 238 Pu is detected infrequently. Furthermore, the seasonal and time-trend variation of plutonium concentration in surface air followed the stratospheric trends until the early 1980s. After the last Chinese test of 1980, the plutonium concentrations in surface air dropped to the current levels, suggesting that the observed concentrations post-1984 have not been under stratospheric control, but rather reflect the environmental processes such as resuspension. Recent plutonium atmospheric air concentrations data show that besides resuspension, other environmental processes such as global dust storms and biomass burning/wildfire also play an important role in redistributing plutonium in the atmosphere. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Applying Flammability Limit Probabilities and the Normoxic Upward Limiting Pressure Concept to NASA STD-6001 Test 1

    NASA Technical Reports Server (NTRS)

    Olson, Sandra L.; Beeson, Harold; Fernandez-Pello, A. Carlos

    2014-01-01

    Repeated Test 1 extinction tests near the upward flammability limit are expected to follow a Poisson process trend. This Poisson process trend suggests that rather than define a ULOI and MOC (which requires two limits to be determined), it might be better to define a single upward limit as being where 1/e (where e (approx. equal to 2.7183) is the characteristic time of the normalized Poisson process) of the materials burn, or, rounding, where approximately 1/3 of the samples fail the test (and burn). Recognizing that spacecraft atmospheres will not bound the entire oxygen-pressure parameter space, but actually lie along the normoxic atmosphere control band, we can focus the materials flammability testing along this normoxic band. A Normoxic Upward Limiting Pressure (NULP) is defined that determines the minimum safe total pressure for a material within the constant partial pressure control band. Then, increasing this pressure limit by a factor of safety, we can define the material as being safe to use at the NULP + SF (where SF is on the order of 10 kilopascal, based on existing flammability data). It is recommended that the thickest material to be tested with the current Test 1 igniter should be 3 mm thick (1/8 inches) to avoid the problem of differentiating between an ignition limit and a true flammability limit.

  15. Applying Econometrics to the Carbon Dioxide “Control Knob”

    PubMed Central

    Curtin, Timothy

    2012-01-01

    This paper tests various propositions underlying claims that observed global temperature change is mostly attributable to anthropogenic noncondensing greenhouse gases, and that although water vapour is recognized to be a dominant contributor to the overall greenhouse gas (GHG) effect, that effect is merely a “feedback” from rising temperatures initially resulting only from “non-condensing” GHGs and not at all from variations in preexisting naturally caused atmospheric water vapour (i.e., [H2O]). However, this paper shows that “initial radiative forcing” is not exclusively attributable to forcings from noncondensing GHG, both because atmospheric water vapour existed before there were any significant increases in GHG concentrations or temperatures and also because there is no evidence that such increases have produced measurably higher [H2O]. The paper distinguishes between forcing and feedback impacts of water vapour and contends that it is the primary forcing agent, at much more than 50% of the total GHG gas effect. That means that controlling atmospheric carbon dioxide is unlikely to be an effective “control knob” as claimed by Lacis et al. (2010). PMID:22629196

  16. Applying econometrics to the carbon dioxide "control knob".

    PubMed

    Curtin, Timothy

    2012-01-01

    This paper tests various propositions underlying claims that observed global temperature change is mostly attributable to anthropogenic noncondensing greenhouse gases, and that although water vapour is recognized to be a dominant contributor to the overall greenhouse gas (GHG) effect, that effect is merely a "feedback" from rising temperatures initially resulting only from "non-condensing" GHGs and not at all from variations in preexisting naturally caused atmospheric water vapour (i.e., [H(2)O]). However, this paper shows that "initial radiative forcing" is not exclusively attributable to forcings from noncondensing GHG, both because atmospheric water vapour existed before there were any significant increases in GHG concentrations or temperatures and also because there is no evidence that such increases have produced measurably higher [H(2)O]. The paper distinguishes between forcing and feedback impacts of water vapour and contends that it is the primary forcing agent, at much more than 50% of the total GHG gas effect. That means that controlling atmospheric carbon dioxide is unlikely to be an effective "control knob" as claimed by Lacis et al. (2010).

  17. A Design Study of Onboard Navigation and Guidance During Aerocapture at Mars. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Fuhry, Douglas Paul

    1988-01-01

    The navigation and guidance of a high lift-to-drag ratio sample return vehicle during aerocapture at Mars are investigated. Emphasis is placed on integrated systems design, with guidance algorithm synthesis and analysis based on vehicle state and atmospheric density uncertainty estimates provided by the navigation system. The latter utilizes a Kalman filter for state vector estimation, with useful update information obtained through radar altimeter measurements and density altitude measurements based on IMU-measured drag acceleration. A three-phase guidance algorithm, featuring constant bank numeric predictor/corrector atmospheric capture and exit phases and an extended constant altitude cruise phase, is developed to provide controlled capture and depletion of orbital energy, orbital plane control, and exit apoapsis control. Integrated navigation and guidance systems performance are analyzed using a four degree-of-freedom computer simulation. The simulation environment includes an atmospheric density model with spatially correlated perturbations to provide realistic variations over the vehicle trajectory. Navigation filter initial conditions for the analysis are based on planetary approach optical navigation results. Results from a selection of test cases are presented to give insight into systems performance.

  18. Development and evaluation of an instantaneous atmospheric corrosion rate monitor

    NASA Astrophysics Data System (ADS)

    Mansfeld, F.; Jeanjaquet, S. L.; Kendig, M. W.; Roe, D. K.

    1985-06-01

    A research program was carried out in which a new instantaneous atmospheric corrosion rate monitor (ACRM) was developed and evaluated, and equipment was constructed which will allow the use of many sensors in an economical way in outdoor exposures. In the first task, the ACRM was developed and tested in flow chambers in which relative humidity and gaseous and particulate pollutant levels can be controlled. Diurnal cycles and periods of rain were simulated. The effects of aerosols were studied. A computerized system was used for collection, storage, and analysis of the electrochemical data. In the second task, a relatively inexpensive electronics system for control of the ACRM and measurement of atmospheric corrosion rates was designed and built. In the third task, calibration of deterioration rates of various metallic and nonmetallic materials with the response of the ACRMs attached to these materials was carried out under controlled environmental conditions using the system developed in the second task. A Quality Assurance project plan was prepared with inputs from the Rockwell International Environmental Monitoring and Service Center and Quality Assurance System audits were performed.

  19. Application of open-path Fourier transform infrared spectroscopy for atmospheric monitoring of a CO2 back-production experiment at the Ketzin pilot site (Germany).

    PubMed

    Sauer, Uta; Borsdorf, H; Dietrich, P; Liebscher, A; Möller, I; Martens, S; Möller, F; Schlömer, S; Schütze, C

    2018-02-03

    During a controlled "back-production experiment" in October 2014 at the Ketzin pilot site, formerly injected CO 2 was retrieved from the storage formation and directly released to the atmosphere via a vent-off stack. Open-path Fourier transform infrared (OP FTIR) spectrometers, on-site meteorological parameter acquisition systems, and distributed CO 2 point sensors monitored gas dispersion processes in the near-surface part of the atmospheric boundary layer. The test site provides a complex and challenging mosaic-like surface setting for atmospheric monitoring which can also be found at other storage sites. The main aims of the atmospheric monitoring of this experiment were (1) to quantify temporal and spatial variations in atmospheric CO 2 concentrations around the emitting vent-off stack and (2) to test if and how atmospheric monitoring can cope with typical environmental and operational challenges. A low environmental risk was encountered during the whole CO 2 back-production experiment. The study confirms that turbulent wind conditions favor atmospheric mixing processes and are responsible for rapid dilution of the released CO 2 leading to decreased detectability at all sensors. In contrast, calm and extremely stable wind conditions (especially occurring during the night) caused an accumulation of gases in the near-ground atmospheric layer with the highest amplitudes in measured gas concentration. As an important benefit of OP FTIR spectroscopic measurements and their ability to detect multiple gas species simultaneously, emission sources could be identified to a much higher certainty. Moreover, even simulation models using simplified assumptions help to find suitable monitoring network designs and support data analysis for certain wind conditions in such a complex environment.

  20. VANDENBERG AIR FORCE BASE, CALIF. - Outside the clean room at Vandenberg Air Force Base, Calif., the SciSat-1 spacecraft (background) has been removed from the shipping container mounting base (lower left) and placed on the handling fixture. Sci-Sat, which will undergo instrument checkout and spacecraft functional testing, weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

    NASA Image and Video Library

    2003-06-26

    VANDENBERG AIR FORCE BASE, CALIF. - Outside the clean room at Vandenberg Air Force Base, Calif., the SciSat-1 spacecraft (background) has been removed from the shipping container mounting base (lower left) and placed on the handling fixture. Sci-Sat, which will undergo instrument checkout and spacecraft functional testing, weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

  1. Accuracy and practicality of a portable ozone monitor for personal exposure estimates

    NASA Astrophysics Data System (ADS)

    Sagona, Jessica A.; Weisel, Clifford P.; Meng, Qingyu

    2018-02-01

    Accurate measurements of personal exposure to atmospheric pollutants such as ozone are important for understanding health risks. We tested a new personal ozone monitor (POM; 2B Technologies) for accuracy, precision, and ease of use. The POM's measurements were compared to simultaneous ozone measurements from a 2B Model 205 monitor and a ThermoScientific 49i monitor, and multiple POMs were placed side-by-side to check precision. Tests were undertaken in a controlled environmental facility, outdoors, and in a private residence. Additionally, ten volunteers wore a POM for five days and answered a questionnaire about its ease of use. The POM measured ozone accurately compared to the 49i ozone monitor, with average relative differences of less than 8%. In the controlled environment tests, the POM's ozone measurements did not change in the presence of additional atmospheric constituents with similar absorption lines to ozone, though there may have been a small decrease in precision and accuracy. Precision between POMs varied by environment (r2 = 0.98 outdoors; r2 = 0.3 to 0.9 in controlled lab conditions). Volunteers reported that the POM was reasonably comfortable to wear, although all reported that they felt that it was too noisy. Overall, the POM is a viable option for personal ozone monitoring.

  2. Double-Layered Atmospheric Pressure Plasma Jet

    NASA Astrophysics Data System (ADS)

    Choi, Jaegu; Matsuo, Keita; Yoshida, Hidekazu; Namihira, Takao; Katsuki, Sunao; Akiyama, Hidenori

    2009-08-01

    In this paper, we present a double-layered atmospheric pressure plasma jet (DLAPPJ) that is expected to improve conventional single-layered atmospheric pressure plasma jets. With the additional introduction of nitrogen gas into the outer nozzle between the inner and outer tubes, the plasma plume is boosted, resulting in a brighter and longer plasma torch, which may have more radicals and which may broaden the application range of atmospheric pressure plasma jets. The characteristics of the proposed device were investigated with the measurement of the visible torch length, wettability tests and optical emission spectroscopy. The results obtained imply that the DLAPPJ can be used for target-based plasma treatments, that is, (a) oxidation-related applications, such as surface treatment, biological decontamination and apoptosis induction, and (b) nitrification-related applications such as NO generation for wound healing and surface modification, by controlling radicals in plasmas.

  3. Lessons Learned from the Node 1 Atmosphere Control and Storage and Water Recovery and Management Subsystem Design

    NASA Technical Reports Server (NTRS)

    Williams, David E.

    2010-01-01

    Node 1 flew to the International Space Station (ISS) on Flight 2A during December 1998. To date the National Aeronautics and Space Administration (NASA) has learned a lot of lessons from this module based on its history of approximately two years of acceptance testing on the ground and currently its twelve years on-orbit. This paper will provide an overview of the ISS Environmental Control and Life Support (ECLS) design of the Node 1 Atmosphere Control and Storage (ACS) and Water Recovery and Management (WRM) subsystems and it will document some of the lessons that have been learned to date for these subsystems based on problems prelaunch, problems encountered on-orbit, and operational problems/concerns. It is hoped that documenting these lessons learned from ISS will help in preventing them in future Programs.

  4. Lessons Learned from the Node 1 Atmosphere Control and Storage and Water Recovery and Management Subsystem Design

    NASA Technical Reports Server (NTRS)

    Williams, David E.

    2011-01-01

    Node 1 flew to the International Space Station (ISS) on Flight 2A during December 1998. To date the National Aeronautics and Space Administration (NASA) has learned a lot of lessons from this module based on its history of approximately two years of acceptance testing on the ground and currently its twelve years on-orbit. This paper will provide an overview of the ISS Environmental Control and Life Support (ECLS) design of the Node 1 Atmosphere Control and Storage (ACS) and Water Recovery and Management (WRM) subsystems and it will document some of the lessons that have been learned to date for these subsystems based on problems prelaunch, problems encountered on-orbit, and operational problems/concerns. It is hoped that documenting these lessons learned from ISS will help in preventing them in future Programs.

  5. A new device for high-temperature in situ GISAXS measurements

    NASA Astrophysics Data System (ADS)

    Fritz-Popovski, Gerhard; Bodner, Sabine C.; Sosada-Ludwikowska, Florentyna; Maier, Günther A.; Morak, Roland; Chitu, Livia; Bruegemann, Lutz; Lange, Joachim; Krane, Hans-Georg; Paris, Oskar

    2018-03-01

    A heating stage originally designed for diffraction experiments is implemented into a Bruker NANOSTAR instrument for in situ grazing incidence small-angle x-ray scattering experiments. A controlled atmosphere is provided by a dome separating the sample environment from the evacuated scattering instrument. This dome is double shelled in order to enable cooling water to flow through it. A mesoporous silica film templated by a self-assembled block copolymer system is investigated in situ during step-wise heating in air. The GISAXS pattern shows the structural development of the ordered lattice of parallel cylindrical pores. The deformation of the elliptical pore-cross section perpendicular to the film surface was studied with increasing temperature. Moreover, the performance of the setup was tested by controlled in situ heating of a copper surface under controlled oxygen containing atmosphere.

  6. 49 CFR 192.479 - Atmospheric corrosion control: General.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Atmospheric corrosion control: General. 192.479... Control § 192.479 Atmospheric corrosion control: General. (a) Each operator must clean and coat each... this section. (b) Coating material must be suitable for the prevention of atmospheric corrosion. (c...

  7. 49 CFR 192.479 - Atmospheric corrosion control: General.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Atmospheric corrosion control: General. 192.479... Control § 192.479 Atmospheric corrosion control: General. (a) Each operator must clean and coat each... this section. (b) Coating material must be suitable for the prevention of atmospheric corrosion. (c...

  8. 49 CFR 192.479 - Atmospheric corrosion control: General.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Atmospheric corrosion control: General. 192.479... Control § 192.479 Atmospheric corrosion control: General. (a) Each operator must clean and coat each... this section. (b) Coating material must be suitable for the prevention of atmospheric corrosion. (c...

  9. 40 CFR 53.22 - Generation of test atmospheres.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods for SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B of part 53 specifies preferred methods for generating test atmospheres and suggested...

  10. 40 CFR 53.22 - Generation of test atmospheres.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods for SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B of part 53 specifies preferred methods for generating test atmospheres and suggested...

  11. 40 CFR 53.22 - Generation of test atmospheres.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Generation of test atmospheres. 53.22... Characteristics of Automated Methods for SO2, CO, O3, and NO2 § 53.22 Generation of test atmospheres. (a) Table B-2 to subpart B of part 53 specifies preferred methods for generating test atmospheres and suggested...

  12. 28 CFR 79.33 - Proof of participation onsite during a period of atmospheric nuclear testing.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... period of atmospheric nuclear testing. 79.33 Section 79.33 Judicial Administration DEPARTMENT OF JUSTICE... Participants § 79.33 Proof of participation onsite during a period of atmospheric nuclear testing. (a... atmospheric nuclear testing as a member of the armed forces or an employee or contractor employee of the DoD...

  13. 28 CFR 79.33 - Proof of participation onsite during a period of atmospheric nuclear testing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... period of atmospheric nuclear testing. 79.33 Section 79.33 Judicial Administration DEPARTMENT OF JUSTICE... Participants § 79.33 Proof of participation onsite during a period of atmospheric nuclear testing. (a... atmospheric nuclear testing as a member of the armed forces or an employee or contractor employee of the DoD...

  14. 28 CFR 79.33 - Proof of participation onsite during a period of atmospheric nuclear testing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... period of atmospheric nuclear testing. 79.33 Section 79.33 Judicial Administration DEPARTMENT OF JUSTICE... Participants § 79.33 Proof of participation onsite during a period of atmospheric nuclear testing. (a... atmospheric nuclear testing as a member of the armed forces or an employee or contractor employee of the DoD...

  15. Safety of nonthermal atmospheric pressure plasma for tooth bleaching evaluated in terms of microhardness and mineral content

    NASA Astrophysics Data System (ADS)

    Nam, S. H.; Hong, J. W.; Lee, H. J.; Jeon, Y. C.; Kim, G. C.

    2017-08-01

    The purpose of this study was to evaluate the influence of bleaching with nonthermal atmospheric pressure plasma and 15% hydrogen peroxide (HP) or 15% carbamide peroxide (CP). Sixty human enamel and dentin slabs were randomly assigned to six groups as follows: Group 1 was a control group and did not receive any treatment; Group 2 was exposed only to plasma, as a negative control; Group 3 was treated with 15% HP; Group 4 was treated with 15% HP plus plasma; Group 5 was treated with 15% CP alone; and Group 6 was treated with 15% CP plus plasma during 30 min bleaching treatments. A microhardness measurement was conducted according to a microhardness tester. The amount of calcium (Ca), phosphorus (P), chloride (Cl), sodium (Na), magnesium (Mg), and zinc (Zn) in the enamel and dentin was quantified with an electron probe microanalyzer (EPMA). The data were analyzed by using the Student’s t test and one-way analysis of variance (ANOVA), complemented by Tukey’s test. The statistical analysis did not show any significant differences in microhardness values and six mineral contents in all groups (p  >  0.05). Therefore, we believe that the application of nonthermal atmospheric pressure plasma is a safe energy source for tooth bleaching.

  16. Long-life mission reliability for outer planet atmospheric entry probes

    NASA Technical Reports Server (NTRS)

    Mccall, M. T.; Rouch, L.; Maycock, J. N.

    1976-01-01

    The results of a literature analysis on the effects of prolonged exposure to deep space environment on the properties of outer planet atmospheric entry probe components are presented. Materials considered included elastomers and plastics, pyrotechnic devices, thermal control components, metal springs and electronic components. The rates of degradation of each component were determined and extrapolation techniques were used to predict the effects of exposure for up to eight years to deep space. Pyrotechnic devices were aged under accelerated conditions to an equivalent of eight years in space and functionally tested. Results of the literature analysis of the selected components and testing of the devices indicated that no severe degradation should be expected during an eight year space mission.

  17. Lunar Atmosphere and Dust Environment Explorer Integration and Test

    NASA Technical Reports Server (NTRS)

    Wright, Michael R.; McCormick, John L.

    2010-01-01

    The Lunar Atmosphere and Dust Environment Explorer (LADEE) is a NASA collaborative flight project to explore the lunar exosphere. It is being developed through a unique partnership between NASA's Ames Research Center (ARC) and Goddard Space Flight Center (GSFC). Each center brings its own experience and flight systems heritage to the task of integrating and testing the LADEE subsystems, instruments, and spacecraft. As an "in-house" flight project being implemented at low-cost and moderate risk, LADEE relies on single-string subsystems and protoflight hardware to accomplish its mission. Integration and test (l&T) of the LADEE spacecraft with the instruments will be performed at GSFC, and includes assembly, integration, functional testing, and flight qualification and acceptance testing. Due to the nature of the LADEE mission, l&T requirements include strict contamination control measures and instrument calibration procedures. Environmental testing will include electromagnetic compatibility (EMC), vibro-acoustic testing, and thermal-balance/vacuum. Upon successful completion of spacecraft l&T, LADEE will be launched from NASA's Wallops Flight Facility. Launch of the LADEE spacecraft is currently scheduled for December 2012.

  18. Space Shuttle life support systems - A status report

    NASA Technical Reports Server (NTRS)

    Faget, M. A.; Guy, W. W.

    1981-01-01

    The Space Shuttle Program has two independent life support systems. One provides the basic environmental control for the Orbiter cabin while the second enables the crewmen to function outside the spacecraft for extravehicular operation. Although both of these systems were developed and fabricated under contract to NASA, all system-level testing was conducted at the Johnson Space Center. The paper will discuss the results of this testing which, in part, includes: (1) certification of the Orbiter cabin atmospheric pressure and composition control system at three operational pressures (8 psia, 9 psia and 14.7 psia); (2) certification of the Orbiter atmospheric revitalization system at 9 psia and 14.7 psia; (3) manrating of the Orbiter airlock at 14.7 psia, 9 psia and vacuum; and (4) certification of the space suit/life support system in the airlock and at deep space thermal/vacuum conditions. In addition, pertinent flight information from the on-orbit performance of the Shuttle life support systems will be presented.

  19. Mimicking Mars: a vacuum simulation chamber for testing environmental instrumentation for Mars exploration.

    PubMed

    Sobrado, J M; Martín-Soler, J; Martín-Gago, J A

    2014-03-01

    We have built a Mars environmental simulation chamber, designed to test new electromechanical devices and instruments that could be used in space missions. We have developed this environmental system aiming at validating the meteorological station Rover Environment Monitoring Station of NASA's Mars Science Laboratory mission currently installed on Curiosity rover. The vacuum chamber has been built following a modular configuration and operates at pressures ranging from 1000 to 10(-6) mbars, and it is possible to control the gas composition (the atmosphere) within this pressure range. The device (or sample) under study can be irradiated by an ultraviolet source and its temperature can be controlled in the range from 108 to 423 K. As an important improvement with respect to other simulation chambers, the atmospheric gas into the experimental chamber is cooled at the walls by the use of liquid-nitrogen heat exchangers. This chamber incorporates a dust generation mechanism designed to study Martian-dust deposition while modifying the conditions of temperature, and UV irradiated.

  20. Experiments on integral length scale control in atmospheric boundary layer wind tunnel

    NASA Astrophysics Data System (ADS)

    Varshney, Kapil; Poddar, Kamal

    2011-11-01

    Accurate predictions of turbulent characteristics in the atmospheric boundary layer (ABL) depends on understanding the effects of surface roughness on the spatial distribution of velocity, turbulence intensity, and turbulence length scales. Simulation of the ABL characteristics have been performed in a short test section length wind tunnel to determine the appropriate length scale factor for modeling, which ensures correct aeroelastic behavior of structural models for non-aerodynamic applications. The ABL characteristics have been simulated by using various configurations of passive devices such as vortex generators, air barriers, and slot in the test section floor which was extended into the contraction cone. Mean velocity and velocity fluctuations have been measured using a hot-wire anemometry system. Mean velocity, turbulence intensity, turbulence scale, and power spectral density of velocity fluctuations have been obtained from the experiments for various configuration of the passive devices. It is shown that the integral length scale factor can be controlled using various combinations of the passive devices.

  1. Space shuttle atmospheric revitalization subsystem/active thermal control subsystem computer program (users manual)

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A shuttle (ARS) atmosphere revitalization subsystem active thermal control subsystem (ATCS) performance routine was developed. This computer program is adapted from the Shuttle EC/LSS Design Computer Program. The program was upgraded in three noteworthy areas: (1) The functional ARS/ATCS schematic has been revised to accurately synthesize the shuttle baseline system definition. (2) The program logic has been improved to provide a more accurate prediction of the integrated ARS/ATCS system performance. Additionally, the logic has been expanded to model all components and thermal loads in the ARS/ATCS system. (3) The program is designed to be used on the NASA JSC crew system division's programmable calculator system. As written the new computer routine has an average running time of five minutes. The use of desk top type calculation equipment, and the rapid response of the program provides the NASA with an analytical tool for trade studies to refine the system definition, and for test support of the RSECS or integrated Shuttle ARS/ATCS test programs.

  2. Input/output models for general aviation piston-prop aircraft fuel economy

    NASA Technical Reports Server (NTRS)

    Sweet, L. M.

    1982-01-01

    A fuel efficient cruise performance model for general aviation piston engine airplane was tested. The following equations were made: (1) for the standard atmosphere; (2) airframe-propeller-atmosphere cruise performance; and (3) naturally aspirated engine cruise performance. Adjustments are made to the compact cruise performance model as follows: corrected quantities, corrected performance plots, algebraic equations, maximize R with or without constraints, and appears suitable for airborne microprocessor implementation. The following hardwares are recommended: ignition timing regulator, fuel-air mass ration controller, microprocessor, sensors and displays.

  3. Performance of a 1-micron, 1-joule Coherent Launch Site Atmospheric Wind Sounder

    NASA Technical Reports Server (NTRS)

    Hawley, James G.; Targ, Russell; Bruner, Richard; Henderson, Sammy W.; Hale, Charles P.; Vetorino, Steven; Lee, R. W.; Harper, Scott; Khan, Tayyab

    1992-01-01

    The paper describes the design and performance of the Coherent Launch Site Atmospheric Wind Sounder (CLAWS), which is a test and demonstration program designed for monitoring winds with a solid-state lidar in real time for the launch site vehicle guidance and control application. Analyses were conducted to trade off CO2 (9.11- and 10.6-microns), Ho:YAG (2.09 microns), and Nd:YAG (1.06-micron) laser-based lidars. The measurements set a new altitude record (26 km) for coherent wind measurements in the stratosphere.

  4. Validation of Ammonia Diffusive and Active Samplers in a Controlled Atmosphere Test Facility Using Traceable Primary Standard Gas Mixtures

    NASA Astrophysics Data System (ADS)

    Martin, N. A.; Ferracci, V.; Cassidy, N.; Hook, J.; Battersby, R. M.; Tang, Y. S.; Stevens, A. C. M.; Jones, M. R.; Braban, C. F.; Gates, L.; Hangartner, M.; Sacco, P.; Pagani, D.; Hoffnagle, J.

    2016-12-01

    Intensive farming, the increased use of fertilizers, and certain industrial processes are believed to be responsible for increases in the amount fraction of ammonia (NH3) found in Europe. NH3 contributes to eutrophication and acidification of land and freshwater, leading to a loss of biodiversity, undesirable changes to the ecosystem, and to secondary particulate matter (PM) formation. Measurements of ambient ammonia over a wide geographical area, are principally carried out with low-cost diffusive samplers or by active sampling with denuders, with each technique delivering time-integrated values over the monitoring period. The goal of this work was to measure the NH3 diffusive sampling rates of five different designs of commercial diffusive samplers (FSM Radiello radial sampler, Gradko diffusion tube, Gradko DIFRAM-400, Passam ammonia sampler, and CEH ALPHA sampler), together with validation tests with a denuder sampler (CEH DELTA denuder). The would deliver validated improvements in the accuracy of ambient measurements of NH3 in the field through the establishment of metrological traceability using new stable ammonia Primary Standard Gas Mixtures (PSMs), developed by gravimetry at NPL. All devices were simultaneously exposed in a controlled atmosphere test facility (CATFAC) containing traceable amount fractions of ammonia applicable to a range of ambient monitoring conditions, with well-defined conditions of temperature, relative humidity and wind speed. Online continuous monitoring of the test atmospheres was carried out with a calibrated cavity ring-down spectrometer modified to account for cross interference by water. Exposed samplers were analysed by individual manufacturers for ammonium using traceable wet chemical techniques. The measured diffusive sampling rates were then applied to field measurements carried out at the Whim Bog experimental station in Scotland, where there is a facility in place for controlled releases of NH3 and also a background site.

  5. A comparision of temperature detection with the small rotorcraft and the balloon

    NASA Astrophysics Data System (ADS)

    Cui, X.

    2016-12-01

    To observe the upper atmosphere, we can use balloons, aircrafts, and rockets etc. With the popularity of UAV applications in various fields, the use of small rotorcraft as a meteorological observation carrier has gained more and more attention. Small rotorcrafts have the following advantages, such as easy portability, high controllability, and reusable. They have a good prospect in the atmospheric boundary layer detection. In this paper, we detect the vertical temperature profile using the small rotorcraft carrying the temperature sensor and also the radiosonde at the same time. We conduct flight tests in Baoshan District Meteorological Bureau of Shanghai in China as is shown in Fig. 1, and mainly focus on the comparision of their differences. The preliminary results showed that the absolute error is less than 0.07 ° comparing with the balloon-borne sensors as is shown in Fig. 2. Our tests showed that using small rotorcraft as a platform to observe the atmosphere is feasible means.

  6. Morpheus Lander Roll Control System and Wind Modeling

    NASA Technical Reports Server (NTRS)

    Gambone, Elisabeth A.

    2014-01-01

    The Morpheus prototype lander is a testbed capable of vertical takeoff and landing developed by NASA Johnson Space Center to assess advanced space technologies. Morpheus completed a series of flight tests at Kennedy Space Center to demonstrate autonomous landing and hazard avoidance for future exploration missions. As a prototype vehicle being tested in Earth's atmosphere, Morpheus requires a robust roll control system to counteract aerodynamic forces. This paper describes the control algorithm designed that commands jet firing and delay times based on roll orientation. Design, analysis, and testing are supported using a high fidelity, 6 degree-of-freedom simulation of vehicle dynamics. This paper also details the wind profiles generated using historical wind data, which are necessary to validate the roll control system in the simulation environment. In preparation for Morpheus testing, the wind model was expanded to create day-of-flight wind profiles based on data delivered by Kennedy Space Center. After the test campaign, a comparison of flight and simulation performance was completed to provide additional model validation.

  7. Dominant controls of transpiration along a hillslope transect inferred from ecohydrological measurements and thermodynamic limits

    NASA Astrophysics Data System (ADS)

    Renner, Maik; Hassler, Sibylle K.; Blume, Theresa; Weiler, Markus; Hildebrandt, Anke; Guderle, Marcus; Schymanski, Stanislaus J.; Kleidon, Axel

    2016-05-01

    We combine ecohydrological observations of sap flow and soil moisture with thermodynamically constrained estimates of atmospheric evaporative demand to infer the dominant controls of forest transpiration in complex terrain. We hypothesize that daily variations in transpiration are dominated by variations in atmospheric demand, while site-specific controls, including limiting soil moisture, act on longer timescales. We test these hypotheses with data of a measurement setup consisting of five sites along a valley cross section in Luxembourg. Both hillslopes are covered by forest dominated by European beech (Fagus sylvatica L.). Two independent measurements are used to estimate stand transpiration: (i) sap flow and (ii) diurnal variations in soil moisture, which were used to estimate the daily root water uptake. Atmospheric evaporative demand is estimated through thermodynamically constrained evaporation, which only requires absorbed solar radiation and temperature as input data without any empirical parameters. Both transpiration estimates are strongly correlated to atmospheric demand at the daily timescale. We find that neither vapor pressure deficit nor wind speed add to the explained variance, supporting the idea that they are dependent variables on land-atmosphere exchange and the surface energy budget. Estimated stand transpiration was in a similar range at the north-facing and the south-facing hillslopes despite the different aspect and the largely different stand composition. We identified an inverse relationship between sap flux density and the site-average sapwood area per tree as estimated by the site forest inventories. This suggests that tree hydraulic adaptation can compensate for heterogeneous conditions. However, during dry summer periods differences in topographic factors and stand structure can cause spatially variable transpiration rates. We conclude that absorption of solar radiation at the surface forms a dominant control for turbulent heat and mass exchange and that vegetation across the hillslope adjusts to this constraint at the tree and stand level. These findings should help to improve the description of land-surface-atmosphere exchange at regional scales.

  8. Adaptive lyapunov control and artificial neural networks for spacecraft relative maneuvering using atmospheric differential drag

    NASA Astrophysics Data System (ADS)

    Perez Chaparro, David Andres

    At low Earth orbits, a differential in the drag acceleration between spacecraft can be used to control their relative motion. This drag differential allows for a propellant-free alternative to thrusters for performing relative maneuvers in these orbits. The interest in autonomous propellant-less maneuvering comes from the desire to reduce the costs of spacecraft formations. Formation maneuvering opens up a wide variety of new applications for spacecraft missions, such as on-orbit maintenance and refueling. In this work atmospheric differential drag based nonlinear controllers are presented that can be used for virtually any planar relative maneuver of two spacecraft, provided that there is enough atmospheric density and that the spacecraft can change their ballistic coefficients by sufficient amounts to generate the necessary differential accelerations. The control techniques are successfully tested using high fidelity Satellite Tool Kit simulations for re-phase, fly-around, and rendezvous maneuvers, proving the feasibility of the proposed approach for a real flight. Furthermore, the atmospheric density varies in time and in space as the spacecraft travel along their orbits. The ability to accurately forecast the density allows for accurate onboard orbit propagation and for creating realistic guidance trajectories for maneuvers that rely on the differential drag. In this work a localized density predictor based on artificial neural networks is also presented. The predictor uses density measurements or estimates along the past orbits and can use a set of proxies for solar and geomagnetic activities to predict the value of the density along the future orbits of the spacecraft. The performance of the localized predictor is studied for different neural network structures, testing periods of high and low solar and geomagnetic activities and different prediction windows. Comparison with previously developed methods show substantial benefits in using neural networks, both in prediction accuracy and in the potential for spacecraft onboard implementation. The controllers and the predictor are designed for onboard implementation, and provide spacecraft with the tools necessary for performing propellant-less formation maneuvers using differential drag.

  9. 46 CFR 154.901 - Atmospheric control within cargo tanks and cargo piping systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Atmospheric control within cargo tanks and cargo piping systems. 154.901 Section 154.901 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN..., Construction and Equipment Atmospheric Control in Cargo Containment Systems § 154.901 Atmospheric control...

  10. 46 CFR 154.901 - Atmospheric control within cargo tanks and cargo piping systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Atmospheric control within cargo tanks and cargo piping systems. 154.901 Section 154.901 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN..., Construction and Equipment Atmospheric Control in Cargo Containment Systems § 154.901 Atmospheric control...

  11. 46 CFR 154.901 - Atmospheric control within cargo tanks and cargo piping systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Atmospheric control within cargo tanks and cargo piping systems. 154.901 Section 154.901 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN..., Construction and Equipment Atmospheric Control in Cargo Containment Systems § 154.901 Atmospheric control...

  12. 46 CFR 154.901 - Atmospheric control within cargo tanks and cargo piping systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Atmospheric control within cargo tanks and cargo piping systems. 154.901 Section 154.901 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN..., Construction and Equipment Atmospheric Control in Cargo Containment Systems § 154.901 Atmospheric control...

  13. 46 CFR 154.901 - Atmospheric control within cargo tanks and cargo piping systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Atmospheric control within cargo tanks and cargo piping systems. 154.901 Section 154.901 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN..., Construction and Equipment Atmospheric Control in Cargo Containment Systems § 154.901 Atmospheric control...

  14. Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module

    PubMed Central

    Slobodkin, Alexander; Gavrilov, Sergey; Ionov, Victor; Iliyin, Vyacheslav

    2015-01-01

    One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth’s atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite). After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth’s atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport. PMID:26151136

  15. Spore-Forming Thermophilic Bacterium within Artificial Meteorite Survives Entry into the Earth's Atmosphere on FOTON-M4 Satellite Landing Module.

    PubMed

    Slobodkin, Alexander; Gavrilov, Sergey; Ionov, Victor; Iliyin, Vyacheslav

    2015-01-01

    One of the key conditions of the lithopanspermia hypothesis is that microorganisms situated within meteorites could survive hypervelocity entry from space through the Earth's atmosphere. So far, all experimental proof of this possibility has been based on tests with sounding rockets which do not reach the transit velocities of natural meteorites. We explored the survival of the spore-forming thermophilic anaerobic bacterium, Thermoanaerobacter siderophilus, placed within 1.4-cm thick basalt discs fixed on the exterior of a space capsule (the METEORITE experiment on the FOTON-M4 satellite). After 45 days of orbital flight, the landing module of the space vehicle returned to Earth. The temperature during the atmospheric transit was high enough to melt the surface of basalt. T. siderophilus survived the entry; viable cells were recovered from 4 of 24 wells loaded with this microorganism. The identity of the strain was confirmed by 16S rRNA gene sequence and physiological tests. This is the first report on the survival of a lifeform within an artificial meteorite after entry from space orbit through Earth's atmosphere at a velocity that closely approached the velocities of natural meteorites. The characteristics of the artificial meteorite and the living object applied in this study can serve as positive controls in further experiments on testing of different organisms and conditions of interplanetary transport.

  16. Status of 'HIMES' reentry flight test project

    NASA Astrophysics Data System (ADS)

    Inatani, Yoshifumi; Kawaguchi, Jun'ichiro; Yonemoto, Koichi

    1990-10-01

    The salient features of the Highly Maneuverable Experimental Space (HIMES) vehicle which is being developed by the Institute of Space and Astronautical Science of Japan are discussed together with the results of tests conducted. Analytical studies carried out so far include system analyses, aerodynamic design, the navigation/guidance and control systems, the propulsion system, and structural studies. Results of flight tests conducted to verify these analyses include the low-speed gliding flight test and the atmospheric reentry flight test, as well as a ground firing test of the hydrogen-fueled propulsion system. Diagrams are presented of the HIMES vehicle and its propulsion engines.

  17. Probing free-space quantum channels with laboratory-based experiments

    NASA Astrophysics Data System (ADS)

    Bohmann, M.; Kruse, R.; Sperling, J.; Silberhorn, C.; Vogel, W.

    2017-06-01

    Atmospheric channels are a promising candidate to establish secure quantum communication on a global scale. However, due to their turbulent nature, it is crucial to understand the impact of the atmosphere on the quantum properties of light and examine it experimentally. In this paper, we introduce a method to probe atmospheric free-space links with quantum light on a laboratory scale. In contrast to previous works, our method models arbitrary intensity losses caused by turbulence to emulate general atmospheric conditions. This allows us to characterize turbulent quantum channels in a well-controlled manner. To implement this technique, we perform a series of measurements with different constant attenuations and simulate the fluctuating losses by combining the obtained data. We directly test the proposed method with an on-chip source of nonclassical light and a time-bin-multiplexed detection system. With the obtained data, we characterize the nonclassicality of the generated states for different atmospheric noise models and analyze a postselection protocol. This general technique in atmospheric quantum optics allows for studying turbulent quantum channels and predicting their properties for future applications.

  18. THERMAL ENCAPSULATION OF METALS IN SUPERFUND SOILS

    EPA Science Inventory

    Superfund sites frequently contain both heavy metals and organic hazardous waste. If not properly controlled, the metals may be changed to a more leachable form and may also be emitted to the atmosphere via the exhaust stack. This paper documents a batch kiln R&D test program to ...

  19. Project ABLE: (Atmospheric Balloonborne Lidar Experiment)

    NASA Astrophysics Data System (ADS)

    Shepherd, O.; Aurilio, G.; Bucknam, R. D.; Hurd, A. G.; Sheehan, W. H.

    1985-03-01

    Project ABLE (Atmospheric Balloonborne Lidar Experiment) is part of the A.F. Geophysics Laboratory's continuing interest in developing techniques for making remote measurements of atmospheric quantities such as density, pressure, temperatures, and wind motions. The system consists of a balloonborne lidar payload designed to measure neutral molecular density as a function of altitude from ground level to 70 km. The lidar provides backscatter data at the doubled and tripled frequencies of a Nd:YAG laser, which will assist in the separation of the molecular and aerosol contributions and subsequent determination of molecular and aerosol contributions and subsequent determination of molecular density vs altitude. The object of this contract was to fabricate and operate in a field test a balloonborne lidar experiment capable of performing nighttime atmospheric density measurements up to 70 km altitude with a resolution of 150 meters. The payload included a frequency-doubled and -tripled Nd:YAG laser with outputs at 355 and 532 nm; a telescoped receiver with PMT detectors; a command-controlled optical pointing system; and support system, including thermal control, telmetry, command, and power. Successful backscatter measurements were made during field operations which included a balloon launch from Roswell, NM and a flight over the White Sands Missile Range.

  20. Corrective Action Investigation Plan for Corrective Action Unit 104: Area 7 Yucca Flat Atmospheric Test Sites, Nevada National Security Site, Nevada, Revision 0

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

    Patrick Matthews

    2011-08-01

    CAU 104 comprises the 15 CASs listed below: (1) 07-23-03, Atmospheric Test Site T-7C; (2) 07-23-04, Atmospheric Test Site T7-1; (3) 07-23-05, Atmospheric Test Site; (4) 07-23-06, Atmospheric Test Site T7-5a; (5) 07-23-07, Atmospheric Test Site - Dog (T-S); (6) 07-23-08, Atmospheric Test Site - Baker (T-S); (7) 07-23-09, Atmospheric Test Site - Charlie (T-S); (8) 07-23-10, Atmospheric Test Site - Dixie; (9) 07-23-11, Atmospheric Test Site - Dixie; (10) 07-23-12, Atmospheric Test Site - Charlie (Bus); (11) 07-23-13, Atmospheric Test Site - Baker (Buster); (12) 07-23-14, Atmospheric Test Site - Ruth; (13) 07-23-15, Atmospheric Test Site T7-4; (14) 07-23-16,more » Atmospheric Test Site B7-b; (15) 07-23-17, Atmospheric Test Site - Climax These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives (CAAs). Additional information will be obtained by conducting a corrective action investigation before evaluating CAAs and selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible evaluation of viable CAAs that will be presented in the Corrective Action Decision Document. The sites will be investigated based on the data quality objectives (DQOs) developed on April 28, 2011, by representatives of the Nevada Division of Environmental Protection and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office. The DQO process was used to identify and define the type, amount, and quality of data needed to develop and evaluate appropriate corrective actions for CAU 104. The releases at CAU 104 consist of surface-deposited radionuclides from 30 atmospheric nuclear tests. The presence and nature of contamination at CAU 104 will be evaluated based on information collected from a field investigation. Radiological contamination will be evaluated based on a comparison of the total effective dose (TED) to the dose-based final action level (FAL). The presence of TED exceeding the FAL is considered a radiological contaminant of concern (COC). Anything identified as a COC will require corrective action. The TED will be calculated as the total of separate estimates of internal and external dose. Results from the analysis of soil samples will be used to calculate internal radiological dose. Thermoluminescent dosimeters will be used to measure external radiological dose. Based on process knowledge of the releases associated with the nuclear tests and radiological survey information about the location and shape of the resulting contamination plume, it was determined that the releases from the nuclear tests are co-located and will be investigated concurrently. A field investigation will be performed to define areas where TED exceeds the FAL and to determine whether other COCs are present at the site. The investigation will also collect information to determine the presence and nature of contamination associated with migration and excavation, as well as any potential releases discovered during the investigation. Appendix A provides a detailed discussion of the DQO methodology and the DQOs specific to each CAS.« less

  1. Newtonian CAFE: a new ideal MHD code to study the solar atmosphere

    NASA Astrophysics Data System (ADS)

    González-Avilés, J. J.; Cruz-Osorio, A.; Lora-Clavijo, F. D.; Guzmán, F. S.

    2015-12-01

    We present a new code designed to solve the equations of classical ideal magnetohydrodynamics (MHD) in three dimensions, submitted to a constant gravitational field. The purpose of the code centres on the analysis of solar phenomena within the photosphere-corona region. We present 1D and 2D standard tests to demonstrate the quality of the numerical results obtained with our code. As solar tests we present the transverse oscillations of Alfvénic pulses in coronal loops using a 2.5D model, and as 3D tests we present the propagation of impulsively generated MHD-gravity waves and vortices in the solar atmosphere. The code is based on high-resolution shock-capturing methods, uses the Harten-Lax-van Leer-Einfeldt (HLLE) flux formula combined with Minmod, MC, and WENO5 reconstructors. The divergence free magnetic field constraint is controlled using the Flux Constrained Transport method.

  2. Tempest: Mesoscale test case suite results and the effect of order-of-accuracy on pressure gradient force errors

    NASA Astrophysics Data System (ADS)

    Guerra, J. E.; Ullrich, P. A.

    2014-12-01

    Tempest is a new non-hydrostatic atmospheric modeling framework that allows for investigation and intercomparison of high-order numerical methods. It is composed of a dynamical core based on a finite-element formulation of arbitrary order operating on cubed-sphere and Cartesian meshes with topography. The underlying technology is briefly discussed, including a novel Hybrid Finite Element Method (HFEM) vertical coordinate coupled with high-order Implicit/Explicit (IMEX) time integration to control vertically propagating sound waves. Here, we show results from a suite of Mesoscale testing cases from the literature that demonstrate the accuracy, performance, and properties of Tempest on regular Cartesian meshes. The test cases include wave propagation behavior, Kelvin-Helmholtz instabilities, and flow interaction with topography. Comparisons are made to existing results highlighting improvements made in resolving atmospheric dynamics in the vertical direction where many existing methods are deficient.

  3. 49 CFR 193.2627 - Atmospheric corrosion control.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Atmospheric corrosion control. 193.2627 Section... LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Maintenance § 193.2627 Atmospheric corrosion control. Each exposed component that is subject to atmospheric corrosive attack must be protected from...

  4. 49 CFR 193.2627 - Atmospheric corrosion control.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Atmospheric corrosion control. 193.2627 Section... LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Maintenance § 193.2627 Atmospheric corrosion control. Each exposed component that is subject to atmospheric corrosive attack must be protected from...

  5. 49 CFR 193.2627 - Atmospheric corrosion control.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Atmospheric corrosion control. 193.2627 Section... LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Maintenance § 193.2627 Atmospheric corrosion control. Each exposed component that is subject to atmospheric corrosive attack must be protected from...

  6. Elevated in vivo strontium-90 from nuclear weapons test fallout among cancer decedents: a case-control study of deciduous teeth.

    PubMed

    Mangano, Joseph J; Sherman, Janette D

    2011-01-01

    Risks to health from large-scale atmospheric nuclear weapons testing are still relatively unknown. A sample of 85,000 deciduous teeth collected from Americans born during the bomb-testing years assessed risk by in vivo measurement of residual strontium-90 (Sr-90) concentrations, using liquid scintillation spectrometry. The authors' analysis included 97 deciduous teeth from persons born between 1959 and 1961 who were diagrosed with cancer, and 194 teeth of matched controls. Average Sr-90 in teeth of persons who died of cancer was significantly greater than for controls (OR = 2.22; p < 0.04). This discovery suggests that many thousands have died or will die of cancer due to exposure to fallout, far more than previously believed.

  7. Mercury enrichment and its effects on atmospheric emissions in cement plants of China

    NASA Astrophysics Data System (ADS)

    Wang, Fengyang; Wang, Shuxiao; Zhang, Lei; Yang, Hai; Wu, Qingru; Hao, Jiming

    2014-08-01

    The cement industry is one of the most significant anthropogenic sources of atmospheric mercury emissions worldwide. In this study of three typical Chinese cement plants, mercury in kiln flue gas was sampled using the Ontario Hydro Method (OHM), and solid samples were analyzed. Particulate matter recycling, preheating of raw materials, and the use of coal and flue gas desulfurization derived gypsum contributed to emissions of Hg in the air and to accumulation in cement. Over 90% of the mercury input was emitted into the atmosphere. Mercury emission factors were 0.044-0.072 g/t clinker for the test plants. The major species emitted into the atmosphere from cement plants is oxidized mercury, accounting for 61%-91% of the total mercury in flue gas. The results of this study help improve the accuracy of the mercury emission inventory in China and provide useful information for developing mercury controls.

  8. Neutron Particle Effects on a Quad-Redundant Flight Control Computer

    NASA Technical Reports Server (NTRS)

    Eure, Kenneth; Belcastro, Celeste M.; Gray, W Steven; Gonzalex, Oscar

    2003-01-01

    This paper describes a single-event upset experiment performed at the Los Alamos National Laboratory. A closed-loop control system consisting of a Quad-Redundant Flight Control Computer (FCC) and a B737 simulator was operated while the FCC was exposed to a neutron beam. The purpose of this test was to analyze the effects of neutron bombardment on avionics control systems operating at altitudes where neutron strikes are probable. The neutron energy spectrum produced at the Los Alamos National Laboratory is similar in shape to the spectrum of atmospheric neutrons but much more intense. The higher intensity results in accelerated life tests that are representative of the actual neutron radiation that a FCC may receive over a period of years.

  9. Implementation and on-sky results of an optimal wavefront controller for the MMT NGS adaptive optics system

    NASA Astrophysics Data System (ADS)

    Powell, Keith B.; Vaitheeswaran, Vidhya

    2010-07-01

    The MMT observatory has recently implemented and tested an optimal wavefront controller for the NGS adaptive optics system. Open loop atmospheric data collected at the telescope is used as the input to a MATLAB based analytical model. The model uses nonlinear constrained minimization to determine controller gains and optimize the system performance. The real-time controller performing the adaptive optics close loop operation is implemented on a dedicated high performance PC based quad core server. The controller algorithm is written in C and uses the GNU scientific library for linear algebra. Tests at the MMT confirmed the optimal controller significantly reduced the residual RMS wavefront compared with the previous controller. Significant reductions in image FWHM and increased peak intensities were obtained in J, H and K-bands. The optimal PID controller is now operating as the baseline wavefront controller for the MMT NGS-AO system.

  10. BARTTest: Community-Standard Atmospheric Radiative-Transfer and Retrieval Tests

    NASA Astrophysics Data System (ADS)

    Harrington, Joseph; Himes, Michael D.; Cubillos, Patricio E.; Blecic, Jasmina; Challener, Ryan C.

    2018-01-01

    Atmospheric radiative transfer (RT) codes are used both to predict planetary and brown-dwarf spectra and in retrieval algorithms to infer atmospheric chemistry, clouds, and thermal structure from observations. Observational plans, theoretical models, and scientific results depend on the correctness of these calculations. Yet, the calculations are complex and the codes implementing them are often written without modern software-verification techniques. The community needs a suite of test calculations with analytically, numerically, or at least community-verified results. We therefore present the Bayesian Atmospheric Radiative Transfer Test Suite, or BARTTest. BARTTest has four categories of tests: analytically verified RT tests of simple atmospheres (single line in single layer, line blends, saturation, isothermal, multiple line-list combination, etc.), community-verified RT tests of complex atmospheres, synthetic retrieval tests on simulated data with known answers, and community-verified real-data retrieval tests.BARTTest is open-source software intended for community use and further development. It is available at https://github.com/ExOSPORTS/BARTTest. We propose this test suite as a standard for verifying atmospheric RT and retrieval codes, analogous to the Held-Suarez test for general circulation models. This work was supported by NASA Planetary Atmospheres grant NX12AI69G, NASA Astrophysics Data Analysis Program grant NNX13AF38G, and NASA Exoplanets Research Program grant NNX17AB62G.

  11. Test results: Halon 1301 versus water sprinkler fire protection for essential electronic equipment

    NASA Astrophysics Data System (ADS)

    Reichelt, E. F.; Walker, J. L.; Vickers, R. N.; Kwan, A. J.

    1982-07-01

    This report describes results of testing two contending extinguishants, Halon 1301 and water, for fire protection of essential electronic equipment. A series of controlled fires in a facility housing an operational electronic data processing system sought to establish immediate and long term effects of exposure of sensitive electronic equipment and stored data to fire extinguishment atmospheres. Test results lead to the conclusion that Halon 1301 is superior to water as an extinguishant for fires occurring in essential electronic equipment installations.

  12. Aeroassisted orbital maneuvering using Lyapunov optimal feedback control

    NASA Technical Reports Server (NTRS)

    Grantham, Walter J.; Lee, Byoung-Soo

    1987-01-01

    A Liapunov optimal feedback controller incorporating a preferred direction of motion at each state of the system which is opposite to the gradient of a specified descent function is developed for aeroassisted orbital transfer from high-earth orbit to LEO. The performances of the Liapunov controller and a calculus-of-variations open-loop minimum-fuel controller, both of which are based on the 1962 U.S. Standard Atmosphere, are simulated using both the 1962 U.S. Standard Atmosphere and an atmosphere corresponding to the STS-6 Space Shuttle flight. In the STS-6 atmosphere, the calculus-of-variations open-loop controller fails to exit the atmosphere, while the Liapunov controller achieves the optimal minimum-fuel conditions, despite the + or - 40 percent fluctuations in the STS-6 atmosphere.

  13. Guidance and Control of an Autonomous Soaring Vehicle with Flight Test Results

    NASA Technical Reports Server (NTRS)

    Allen, Michael J.

    2007-01-01

    A guidance and control method was developed to detect and exploit thermals for energy gain. Latency in energy rate estimation degraded performance. The concept of a UAV harvesting energy from the atmosphere has been shown to be feasible with existing technology. Many UAVs have similar mission constraints to birds and sailplanes. a) Surveillance; b) Point to point flight with minimal energy; and c) Increased ground speed.

  14. 40 CFR 53.42 - Generation of test atmospheres for wind tunnel tests.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 5 2010-07-01 2010-07-01 false Generation of test atmospheres for wind... Testing Performance Characteristics of Methods for PM10 § 53.42 Generation of test atmospheres for wind... particle delivery system shall consist of a blower system and a wind tunnel having a test section of...

  15. 40 CFR 53.42 - Generation of test atmospheres for wind tunnel tests.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Generation of test atmospheres for wind... Testing Performance Characteristics of Methods for PM10 § 53.42 Generation of test atmospheres for wind... particle delivery system shall consist of a blower system and a wind tunnel having a test section of...

  16. Genetic toxicity studies of organic chemicals found as contaminants in spacecraft cabin atmospheres

    NASA Technical Reports Server (NTRS)

    Torres, Joseph, Jr.

    1987-01-01

    Astronauts can be exposed during spaceflight to organic chemical contaminants in the spacecraft cabin atmosphere. Toxic exposures may cause lesions in the cellular DNA which are subsequently expressed as sister-chromatid exchanges (SCE). Analysis of SCE is a sensitive short term assay techinque to detect and quantitate exposures to DNA damaging (mutagenic) substances. The increase in SCE incidence over baseline (control) levels is generally proportional to the concentration of the mutagen and to the duration of exposure. The BHK-21 baby hamster kidney cell line was the in vitro test system used. Test organics were added to the culture media for 18 hrs, in concentrations ranging from one to 20 ppm. Acetaldehyde and carbon disulfide were chosen for this study since they have occurred as atmospheric contaminants in many of the STS flights, and have been reported to have toxic and mutagenic effects in various test systems. Glutaraldehyde was chosen because few data are available on the mutagenicity of this common fixative, which is carried on STS flights for use in biological experiments. Acetaldehyde was a very strong inducer of SCE at concentrations of 2 ppm and above. Glutaraldehyde and carbon disulfide failed to induce SCE.

  17. In vitro cytogenetic studies of organic chemicals found as contaminants in spacecraft cabin atmospheres

    NASA Technical Reports Server (NTRS)

    Torres, J.

    1986-01-01

    Astronauts can be exposed during spaceflight to organic chemical contaminants in the spacecraft cabin atmosphere. Toxic exposures may cause lesions in the cellular DNA which are subsequently expressed as sister-chromatid exchanges (SCE). Analysis of SCE is a sensitive short-term assay technique to detect and quantitate exposures to DNA-damaging (mutagenic) substances. The increase in SCE incidence over baseline (control) levels is generally proportional to the concentration of the mutagen and to the duration of exposure. Dichloromethane (methylene chloride) was chosen for this study since it occurred as an atmospheric contaminant in ten of the first 12 STS flights, and has been reported to have toxic and mutagenic effects in various test systems. Glutaraldehyde was chosen because relatively few data are available on the toxicity or mutagenicity of this common biological fixative, which is carried on STS flights for use in biological experiments. The BHK-21 baby hamster kidney cell line was the in vitro test system used in this study. Neither dichloromethane (10 ppm to 500 ppm) nor glutaraldehyde (1 ppm to 10 ppm) increased SCE levels following 20-hour exposure of BHK-21 cells to the test chemicals.

  18. Dangerous (toxic) atmospheres in UK wood pellet and wood chip fuel storage.

    PubMed

    Simpson, Andrew T; Hemingway, Michael A; Seymour, Cliff

    2016-09-01

    There is growing use of wood pellet and wood chip boilers in the UK. Elsewhere fatalities have been reported, caused by carbon monoxide poisoning following entry into wood pellet storage areas. The aim of this work was to obtain information on how safely these two fuels are being stored in the UK. Site visits were made to six small-scale boiler systems and one large-scale pellet warehouse, to assess storage practice, risk management systems and controls, user knowledge, and potential for exposure to dangerous atmospheres. Real time measurements were made of gases in the store rooms and during laboratory tests on pellets and chips. Volatile organic compounds (VOCs) emitted and the microbiological content of the fuel was also determined. Knowledge of the hazards associated with these fuels, including confined space entry, was found to be limited at the smaller sites, but greater at the large pellet warehouse. There has been limited risk communication between companies supplying and maintaining boilers, those manufacturing and supplying fuel, and users. Risk is controlled by restricting access to the store rooms with locked entries; some store rooms have warning signs and carbon monoxide alarms. Nevertheless, some store rooms are accessed for inspection and maintenance. Laboratory tests showed that potentially dangerous atmospheres of carbon monoxide and carbon dioxide, with depleted levels of oxygen may be generated by these fuels, but this was not observed at the sites visited. Unplanned ventilation within store rooms was thought to be reducing the build-up of dangerous atmospheres. Microbiological contamination was confined to wood chips.

  19. Dangerous (toxic) atmospheres in UK wood pellet and wood chip fuel storage

    PubMed Central

    Simpson, Andrew T.; Hemingway, Michael A.; Seymour, Cliff

    2016-01-01

    ABSTRACT There is growing use of wood pellet and wood chip boilers in the UK. Elsewhere fatalities have been reported, caused by carbon monoxide poisoning following entry into wood pellet storage areas. The aim of this work was to obtain information on how safely these two fuels are being stored in the UK. Site visits were made to six small-scale boiler systems and one large-scale pellet warehouse, to assess storage practice, risk management systems and controls, user knowledge, and potential for exposure to dangerous atmospheres. Real time measurements were made of gases in the store rooms and during laboratory tests on pellets and chips. Volatile organic compounds (VOCs) emitted and the microbiological content of the fuel was also determined. Knowledge of the hazards associated with these fuels, including confined space entry, was found to be limited at the smaller sites, but greater at the large pellet warehouse. There has been limited risk communication between companies supplying and maintaining boilers, those manufacturing and supplying fuel, and users. Risk is controlled by restricting access to the store rooms with locked entries; some store rooms have warning signs and carbon monoxide alarms. Nevertheless, some store rooms are accessed for inspection and maintenance. Laboratory tests showed that potentially dangerous atmospheres of carbon monoxide and carbon dioxide, with depleted levels of oxygen may be generated by these fuels, but this was not observed at the sites visited. Unplanned ventilation within store rooms was thought to be reducing the build-up of dangerous atmospheres. Microbiological contamination was confined to wood chips. PMID:27030057

  20. Laboratory MCAO Test-Bed for Developing Wavefront Sensing Concepts.

    PubMed

    Goncharov, A V; Dainty, J C; Esposito, S; Puglisi, A

    2005-07-11

    An experimental optical bench test-bed for developing new wavefront sensing concepts for Multi-Conjugate Adaptive Optics (MCAO) systems is described. The main objective is to resolve imaging problems associated with wavefront sensing of the atmospheric turbulence for future MCAO systems on Extremely Large Telescopes (ELTs). The test-bed incorporates five reference sources, two deformable mirrors (DMs) and atmospheric phase screens to simulate a scaled version of a 10-m adaptive telescope operating at the K band. A recently proposed compact tomographic wavefront sensor is employed for star-oriented DMs control in the MCAO system. The MCAO test-bed is used to verify the feasibility of the wavefront sensing concept utilizing a field lenslet array for multi-pupil imaging on a single detector. First experimental results of MCAO correction with the proposed tomographic wavefront sensor are presented and compared to the theoretical prediction based on the characteristics of the phase screens, actuator density of the DMs and the guide star configuration.

  1. Corrective Action Decision Document/Closure Report for Corrective Action Unit 105: Area 2 Yucca Flat Atmospheric Test Sites, Nevada National Security Site, Nevada, Revision 0

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

    Matthews, Patrick

    2013-09-01

    This Corrective Action Decision Document/Closure Report presents information supporting the closure of Corrective Action Unit (CAU) 105: Area 2 Yucca Flat Atmospheric Test Sites, Nevada National Security Site, Nevada. CAU 105 comprises the following five corrective action sites (CASs): -02-23-04 Atmospheric Test Site - Whitney Closure In Place -02-23-05 Atmospheric Test Site T-2A Closure In Place -02-23-06 Atmospheric Test Site T-2B Clean Closure -02-23-08 Atmospheric Test Site T-2 Closure In Place -02-23-09 Atmospheric Test Site - Turk Closure In Place The purpose of this Corrective Action Decision Document/Closure Report is to provide justification and documentation supporting the recommendation that nomore » further corrective action is needed for CAU 105 based on the implementation of the corrective actions. Corrective action investigation (CAI) activities were performed from October 22, 2012, through May 23, 2013, as set forth in the Corrective Action Investigation Plan for Corrective Action Unit 105: Area 2 Yucca Flat Atmospheric Test Sites; and in accordance with the Soils Activity Quality Assurance Plan, which establishes requirements, technical planning, and general quality practices.« less

  2. Breadboard Solid Amine Water Desorbed CO2 Control System

    NASA Technical Reports Server (NTRS)

    Colling, A. K.; Hultman, M. M.

    1980-01-01

    A regenerable CO2 removal system was developed for potential use on the shuttle as an alternate to the baseline lithium hydroxide (LiOH) system. It uses a solid amine material to adsorb CO2 from the atmosphere. The material is regenerated by heating it with steam from a zero gravity water evaporator. A full sized, thermally representative breadboard canister and a preprototype water evaporator were built and tested to shuttle requirements for CO2 control. The test program was utilized to evaluate and verify the operation and performance of these two primary components of the SAWD system.

  3. Further follow up of mortality and incidence of cancer in men from the United Kingdom who participated in the United Kingdom's atmospheric nuclear weapon tests and experimental programmes.

    PubMed Central

    Darby, S C; Kendall, G M; Fell, T P; Doll, R; Goodill, A A; Conquest, A J; Jackson, D A; Haylock, R G

    1993-01-01

    OBJECTIVES--To study the long term effects of participation in the United Kingdom's atmospheric nuclear weapon tests and experimental programmes and to test hypotheses generated by an earlier report, including the possibility that participation in tests caused small hazards of leukaemia and multiple myeloma. DESIGN--Follow up study of mortality and cancer incidence. SUBJECTS--21,358 servicemen and civilians from the United Kingdom who participated in the tests and a control group of 22,333 non-participants. MAIN OUTCOME MEASURES--Numbers of deaths; standardised mortality ratios; relative risks of mortality from all causes and 27 types of cancer. RESULTS--During seven further years of follow up the numbers of deaths observed in participants were fewer than expected from national rates for all causes, all neoplasms, leukaemia, and multiple myeloma (standardised mortality ratios 0.86, 0.85, 0.57, and 0.46); death rates were lower than in controls (relative risks 0.99, 0.96, 0.57, and 0.57; 90% confidence intervals all included 1.00). In the period more than 10 years after the initial participation in tests the relative risk of death in participants compared with controls was near unity for all causes (relative risk 0.99 (0.95 to 1.04) and all neoplasms (0.95 (0.87 to 1.04)); it was raised for bladder cancer (2.69 (1.42 to 5.20)) and reduced for cancers of the mouth, tongue, and pharynx (0.45 (0.22 to 0.93)) and for lung cancer (0.85 (0.73 to 0.99)). For leukaemia mortality was equal to that expected from national rates but greater than in controls for both the whole follow up period (1.75 (1.01 to 3.06)) and the period 2-25 years after the tests (3.38 (1.45 to 8.25)). CONCLUSION--Participation in nuclear weapon tests had no detectable effect on expectation of life or on subsequent risk of developing cancer or other fatal diseases. The excess of leukaemia in participants compared with controls seems to be principally due to a chance deficit in the controls, but the possibility that participation in the tests may have caused a small risk of leukaemia in the early years afterwards cannot be ruled out. PMID:8274923

  4. Atmospheric, Magnetospheric and Plasmas in Space (AMPS) spacelab payload definition study. Volume 3: Interface control documents. Part 1: AMPS payload to shuttle ICD

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Physical, functional, and operational interfaces between the space shuttle orbiter and the AMPS payload are described for the ground handling and test phases, prelaunch, launch and ascent, operational, stowage, and reentry and landing activities.

  5. Dynamics Explorer twin spacecraft under evaluation tests

    NASA Technical Reports Server (NTRS)

    Redmond, C.

    1981-01-01

    The Dynamics Explorer A and B satellites designed to explore the interactive processes occuring between the magnetosphere and Earth's ionosphere, upper atmosphere, and plasmasphere are described. Effects of these interactions, satellite orbits, data collecting antennas, solar power systems, axes, configurations, and Earth based command, control and data display systems are mentioned.

  6. Central Control Room in the Engine Research Building

    NASA Image and Video Library

    1968-11-21

    Operators in the Engine Research Building’s Central Control Room at the National Aeronautics and Space Administration (NASA) Lewis Research Center. The massive 4.25-acre Engine Research Building contains dozens of test cells, test stands, and altitude chambers. A powerful a collection of compressors and exhausters located in the central portion of the basement provides process air and exhaust for these test areas. This system is connected to similar process air systems in the laboratory’s other large test facilities. The Central Control Room coordinates this activity and communicates with the local utilities. The panels on the wall contain schematics with indicator lights and instrumentation for the atmospheric exhaust, altitude exhaust, refrigerated air, and process air systems. The process air equipment included twelve exhausters, four compressors, refrigeration system, cooling water, and an exhaust system. The operators in the control room kept in contact with engineers running the process air system and those conducting the tests in the test cells. The operators also coordinated with the local power companies to make sure enough electricity was available to operate the powerful compressors and exhausters.

  7. Leak Rate Quantification Method for Gas Pressure Seals with Controlled Pressure Differential

    NASA Technical Reports Server (NTRS)

    Daniels, Christopher C.; Braun, Minel J.; Oravec, Heather A.; Mather, Janice L.; Taylor, Shawn C.

    2015-01-01

    An enhancement to the pressure decay leak rate method with mass point analysis solved deficiencies in the standard method. By adding a control system, a constant gas pressure differential across the test article was maintained. As a result, the desired pressure condition was met at the onset of the test, and the mass leak rate and measurement uncertainty were computed in real-time. The data acquisition and control system were programmed to automatically stop when specified criteria were met. Typically, the test was stopped when a specified level of measurement uncertainty was attained. Using silicone O-ring test articles, the new method was compared with the standard method that permitted the downstream pressure to be non-constant atmospheric pressure. The two methods recorded comparable leak rates, but the new method recorded leak rates with significantly lower measurement uncertainty, statistical variance, and test duration. Utilizing this new method in leak rate quantification, projects will reduce cost and schedule, improve test results, and ease interpretation between data sets.

  8. KSC-2013-3560

    NASA Image and Video Library

    2013-09-11

    CAPE CANAVERAL, Fla. – At NASA's Kennedy Space Center in Florida, engineers are running tests between the Mars Atmosphere and Volatile Evolution, or MAVEN, spacecraft and MIL-71. The control room is the Kennedy interface with the Deep Space Network, or DSN. This compatibility test with MAVEN will verify that the spacecraft will be able to relay data back through the DSN interfaces during its mission to the Red Planet. MAVEN is being prepared for its scheduled launch in November from Cape Canaveral Air Force Station, Fla. atop a United Launch Alliance Atlas V rocket. Positioned in an orbit above the Red Planet, MAVEN will study the upper atmosphere of Mars in unprecedented detail. For more information, visit: http://www.nasa.gov/mission_pages/maven/main/index.html Photo credit: NASA/Jim Grossmann

  9. Image-guided plasma therapy of cutaneous wound

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiwu; Ren, Wenqi; Yu, Zelin; Zhang, Shiwu; Yue, Ting; Xu, Ronald

    2014-02-01

    The wound healing process involves the reparative phases of inflammation, proliferation, and remodeling. Interrupting any of these phases may result in chronically unhealed wounds, amputation, or even patient death. Despite the clinical significance in chronic wound management, no effective methods have been developed for quantitative image-guided treatment. We integrated a multimodal imaging system with a cold atmospheric plasma probe for image-guided treatment of chronic wound. Multimodal imaging system offers a non-invasive, painless, simultaneous and quantitative assessment of cutaneous wound healing. Cold atmospheric plasma accelerates the wound healing process through many mechanisms including decontamination, coagulation and stimulation of the wound healing. The therapeutic effect of cold atmospheric plasma is studied in vivo under the guidance of a multimodal imaging system. Cutaneous wounds are created on the dorsal skin of the nude mice. During the healing process, the sample wound is treated by cold atmospheric plasma at different controlled dosage, while the control wound is healed naturally. The multimodal imaging system integrating a multispectral imaging module and a laser speckle imaging module is used to collect the information of cutaneous tissue oxygenation (i.e. oxygen saturation, StO2) and blood perfusion simultaneously to assess and guide the plasma therapy. Our preliminary tests show that cold atmospheric plasma in combination with multimodal imaging guidance has the potential to facilitate the healing of chronic wounds.

  10. Influence of aramid fiber moisture regain during atmospheric plasma treatment on aging of treatment effects on surface wettability and bonding strength to epoxy

    NASA Astrophysics Data System (ADS)

    Ren, Yu; Wang, Chunxia; Qiu, Yiping

    2007-09-01

    One of the main differences between a low-pressure plasma treatment and an atmospheric pressure plasma treatment is that in atmosphere, the substrate material may absorb significant amount of water which may potentially influence the plasma treatment effects. This paper investigates how the moisture absorbed by aramid fibers during the atmospheric pressure plasma treatment influences the aging behavior of the modified surfaces. Kevlar 49 fibers with different moisture regains (MR) (0.5, 3.5 and 5.5%, respectively) are treated with atmospheric pressure plasma jet (APPJ) with helium as the carrier gas and oxygen as the treatment gas. Surface wettability and chemical compositions, and interfacial shear strengths (IFSS) to epoxy for the aramid fibers in all groups are determined using water contact angle measurements, X-ray photoelectron spectroscopy (XPS), and micro-bond pull out tests, respectively. Immediately after the plasma treatment, the treated fibers have substantially lower water contact angles, higher surface oxygen and nitrogen contents, and larger IFSS to epoxy than those of the control group. At the end of 30 day aging period, the fibers treated with 5.5% moisture regain had a lower water contact angle and more polar groups on the fiber surface, leading to 75% improvement of IFSS over the control fibers, while those for the 0.5 and 3.5% moisture regain groups were only 30%.

  11. Evaluation of an Atmosphere Revitalization Subsystem for Deep Space Exploration Missions

    NASA Technical Reports Server (NTRS)

    Perry, Jay L.; Abney, Morgan B.; Conrad, Ruth E.; Frederick, Kenneth R.; Greenwood, Zachary W.; Kayatin, Matthew J.; Knox, James C.; Newton, Robert L.; Parrish, Keith J.; Takada, Kevin C.; hide

    2015-01-01

    An Atmosphere Revitalization Subsystem (ARS) suitable for deployment aboard deep space exploration mission vehicles has been developed and functionally demonstrated. This modified ARS process design architecture was derived from the International Space Station's (ISS) basic ARS. Primary functions considered in the architecture include trace contaminant control, carbon dioxide removal, carbon dioxide reduction, and oxygen generation. Candidate environmental monitoring instruments were also evaluated. The process architecture rearranges unit operations and employs equipment operational changes to reduce mass, simplify, and improve the functional performance for trace contaminant control, carbon dioxide removal, and oxygen generation. Results from integrated functional demonstration are summarized and compared to the performance observed during previous testing conducted on an ISS-like subsystem architecture and a similarly evolved process architecture. Considerations for further subsystem architecture and process technology development are discussed.

  12. A Flight Control Approach for Small Reentry Vehicles

    NASA Technical Reports Server (NTRS)

    Bevacqoa, Tim; Adams, Tony; Zhu. J. Jim; Rao, P. Prabhakara

    2004-01-01

    Flight control of small crew return vehicles during atmospheric reentry will be an important technology in any human space flight mission undertaken in the future. The control system presented in this paper is applicable to small crew return vehicles in which reaction control system (RCS) thrusters are the only actuators available for attitude control. The control system consists of two modules: (i) the attitude controller using the trajectory linearization control (TLC) technique, and (ii) the reaction control system (RCS) control allocation module using a dynamic table-lookup technique. This paper describes the design and implementation of the TLC attitude control and the dynamic table-lookup RCS control allocation for nonimal flight along with design verification test results.

  13. 49 CFR 193.2627 - Atmospheric corrosion control.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Atmospheric corrosion control. 193.2627 Section... LIQUEFIED NATURAL GAS FACILITIES: FEDERAL SAFETY STANDARDS Maintenance § 193.2627 Atmospheric corrosion... atmospheric corrosion by— (a) Material that has been designed and selected to resist the corrosive atmosphere...

  14. Strategic stalemate: Nuclear weapons and arms control in American politics

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

    Krepon, M.

    1984-01-01

    This book presents a concise analysis of the American debate over arms control measures from the atmospheric test ban treaty of 1963 to the present. The author demonstrates the continuity of positions held by the participants throughout. There are two ''camps:'' those who stress security through military means and those who believe above all in arms control or disarmament. The camps in turn, contain ''operationalists,'' who pursue arms control but with differing emphases, and ''ideologues,'' who reject arms control in favor of superiority, at one end of the spectrum, or in favor of disarmament, at the other end.

  15. Data quality objectives for the initial fuel conditioning examinations

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

    Lawrence, L.A.

    The Data Quality Objectives (DQOs) were established for the response of the first group of fuel samples shipped from the K West Basin to the Hanford 327 Building hot cells for examinations to the proposed Path Forward conditioning process. Controlled temperature and atmosphere furnace testing testing will establish performance parameters using the conditioning process (drying, sludge drying, hydride decomposition passivation) proposed by the Independent Technical Assessment (ITA) Team as the baseline.

  16. Microbolometer characterization with the electronics prototype of the IRCAM for the JEM-EUSO mission

    NASA Astrophysics Data System (ADS)

    Martín, Yolanda; Joven, Enrique; Reyes, Marcos; Licandro, Javier; Maroto, Oscar; Díez-Merino, Laura; Tomas, Albert; Carbonell, Jordi; Morales de los Ríos, J. A.; del Peral, Luis; Rodríguez-Frías, M. D.

    2014-08-01

    JEM-EUSO is a space observatory that will be attached to the Japanese module of the International Space Station (ISS) to observe the UV photon tracks produced by Ultra High Energy Cosmic Rays (UHECR) interacting with atmospheric nuclei. The observatory comprises an Atmospheric Monitoring System (AMS) to gather data about the status of the atmosphere, including an infrared camera (IRCAM) for cloud coverage and cloud top height detection. This paper describes the design and characterization tests of IRCAM, which is the responsibility of the Spanish JEM-EUSO Consortium. The core of IRCAM is a 640x480 microbolometer array, the ULIS 04171, sensitive to radiation in the range 7 to 14 microns. The microbolometer array has been tested using the Front End Electronics Prototype (FEEP). This custom designed electronics corresponds to the Breadboard Model, a design built to verify the camera requirements in the laboratory. The FEEP controls the configuration of the microbolometer, digitizes the detector output, sends data to the Instrument Control Unit (ICU), and controls the microbolometer temperature to a 10 mK stability. Furthermore, the FEEP allows IRCAM to preprocess images by the addition of a powerful FPGA. This prototype has been characterized in the laboratories of Instituto de Astrofisica de Canarias (IAC). Main results, including detector response as a function of the scene temperature, NETD and Non-Uniformity Correction (NUC) are shown. Results about thermal resolution meet the system requirements with a NETD lower than 1K including the narrow band filters which allow us to retrieve the clouds temperature using stereovision algorithms.

  17. Tactical missile turbulence problems

    NASA Technical Reports Server (NTRS)

    Dickson, Richard E.

    1987-01-01

    Of particular interest is atmospheric turbulence in the atmospheric boundary layer, since this affects both the launch and terminal phase of flight, and the total flight for direct fire systems. Brief discussions are presented on rocket artillery boost wind problems, mean wind correction, turbulent boost wind correction, the Dynamically Aimed Free Flight Rocket (DAFFR) wind filter, the DAFFR test, and rocket wake turbulence problems. It is concluded that many of the turbulence problems of rockets and missiles are common to those of aircraft, such as structural loading and control system design. However, these problems have not been solved at this time.

  18. Online Resource for Earth-Observing Satellite Sensor Calibration

    NASA Technical Reports Server (NTRS)

    McCorkel, J.; Czapla-Myers, J.; Thome, K.; Wenny, B.

    2015-01-01

    The Radiometric Calibration Test Site (RadCaTS) at Railroad Valley Playa, Nevada is being developed by the University of Arizona to enable improved accuracy and consistency for airborne and satellite sensor calibration. Primary instrumentation at the site consists of ground-viewing radiometers, a sun photometer, and a meteorological station. Measurements made by these instruments are used to calculate surface reflectance, atmospheric properties and a prediction for top-of-atmosphere reflectance and radiance. This work will leverage research for RadCaTS, and describe the requirements for an online database, associated data formats and quality control, and processing levels.

  19. Effect of Several Factors on the Cooling of a Radial Engine in Flight

    NASA Technical Reports Server (NTRS)

    Schey, Oscar W; Pinkel, Benjamin

    1936-01-01

    Flight tests of a Grumman Scout (XSF-2) airplane fitted with a Pratt & Whitney 1535 supercharged engine were conducted to determine the effect of engine power, mass flow of the cooling air, and atmospheric temperature on cylinder temperature. The tests indicated that the difference in temperature between the cylinder wall and the cooling air varied as the 0.38 power of the brake horsepower for a constant mass flow of cooling air, cooling-air temperature, engine speed, and brake fuel consumption. The difference in temperature was also found to vary inversely as the 0.39 power of the mass flow for points on the head and the 0.35 power for points on the barrel, provided that engine power, engine speed, brake fuel consumption, and cooling-air temperature were kept constant. The results of the tests of the effect of atmospheric temperature on cylinder temperature were inconclusive owing to unfavorable weather conditions prevailing at the time of the tests. The method used for controlling the test conditions, however, was found to be feasible.

  20. Evaluation of residual radioactivity in human tissues associated with weapons testing at the nevada test site. Technical report, 1 June 1981-31 March 1989

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

    Wrenn, M.E.; Singh, N.P.; Paschoa, A.S.

    1992-11-01

    Residual radioactivity consisting of 239 Pu were measured by radiochemistry and alpha spectrometry in samples of bone and soft tissues from 100 autopsies or surgeries from northern and southwestern Utah and from control areas in Colorado and Pennsylvania. Based upon the isotopic ratio 240 Pu/239 Pu contamination was attributable to atmospheric weapons tests at the Nevada Test Site (NTS). In addition, 110 thyroid tissue samples obtained from tissue blocks made at autopsy of veterans dying at the VA hospital in Salt Lake City in the 1940's and 1950's were measured for 129 I (half life 16 million year) and 127more » I (stable) by neutron activation. The results were analyzed by year of death, by periods before and during atmospheric nuclear weapons testing at the NTS and by origin of usual residence. A model was developed to relate thyroid dose from 131 I to the measured 124/127 I ratios, and thyroid dose estimates were made based upon the measured ratios.« less

  1. Quality of Golden papaya stored under controlled atmosphere conditions.

    PubMed

    Martins, Derliane Ribeiro; de Resende, Eder Dutra

    2013-10-01

    This work evaluated physicochemical parameters of Golden papaya stored under refrigeration in controlled atmospheres. The fruits were kept at 13  in chambers containing either 3 or 6% O2 combined with 6%, 10% or 15% CO2. Moreover, a normal atmosphere was produced with 20.8% O2 and 0.03% CO2 with ethylene scrubbing, and a control treatment was used with ambient conditions. Evaluations were performed at the following times: before storage, after 30 days of storage in controlled atmosphere, and after removal from controlled atmosphere and storage for 7 days in the cold room. At the lower O2 levels and higher CO2 levels, the ripening rate was decreased. The drop in pulp acidity was avoided after 30 days of storage at 3% O2, but the fruits reached normal acidity after removal from controlled atmosphere and storage for 7 days in the cold room. The reducing sugars remained at a higher concentration after 30 days under 3% O2 and 15% CO2 even 7 days after removal from controlled atmosphere and storage in the cold room. This atmosphere also preserved the content of ascorbic acid at a higher level.

  2. Improved carbon control in the sintering of structural PM parts

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

    Nowotarski, M.; Gaines, G.

    1981-12-01

    The use of a nitrogen-methanol atmosphere and a system of control of the atmosphere in furnace zones to provide improved control of carbon in sintering of sprockets are described.A new process has been developed by the Linde Div. of Union Carbide for the sintering of structural PM parts. The process is based on a nitrogen/methanol sintering atmosphere and features superior carbon control (/plus or minus/.03%), elimination of sooting due to lubricant decomposition, and significantly reduced furnace atmosphere gas flows as compared to typical endothermic atmosphere gas consumption.

  3. Lunar Module ECS (Environmental Control System) - Design Considerations and Failure Modes. Part 1

    NASA Technical Reports Server (NTRS)

    Interbartolo, Michael

    2009-01-01

    Design considerations and failure modes for the Lunar Module (LM) Environmental Control System (ECS) are described. An overview of the the oxygen supply and cabin pressurization, atmosphere revitalization, water management and heat transport systems are provided. Design considerations including reliability, flight instrumentation, modularization and the change to the use of batteries instead of fuel cells are discussed. A summary is provided for the LM ECS general testing regime.

  4. State of the art in medical applications using non-thermal atmospheric pressure plasma

    NASA Astrophysics Data System (ADS)

    Tanaka, Hiromasa; Ishikawa, Kenji; Mizuno, Masaaki; Toyokuni, Shinya; Kajiyama, Hiroaki; Kikkawa, Fumitaka; Metelmann, Hans-Robert; Hori, Masaru

    2017-12-01

    Plasma medical science is a novel interdisciplinary field that combines studies on plasma science and medical science, with the anticipation that understanding the scientific principles governing plasma medical science will lead to innovations in the field. Non-thermal atmospheric pressure plasma has been used for medical treatments, such as for cancer, blood coagulation, and wound healing. The interactions that occur between plasma and cells/tissues have been analyzed extensively. Direct and indirect treatment of cells with plasma has broadened the applications of non-thermal atmospheric pressure plasma in medicine. Examples of indirect treatment include plasma-assisted immune-therapy and plasma-activated medium. Controlling intracellular redox balance may be key in plasma cancer treatment. Animal studies are required to test the effectiveness and safety of these treatments for future clinical applications.

  5. Development of an Atmospheric Pressure Ionization Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    1998-01-01

    A commercial atmospheric pressure ionization mass spectrometer (APIMS) was purchased from EXTREL Mass Spectrometry, Inc. (Pittsburgh, PA). Our research objectives were to adapt this instrument and develop techniques for real-time determinations of the concentrations of trace species in the atmosphere. The prototype instrument is capable of making high frequency measurements with no sample preconcentrations. Isotopically labeled standards are used as an internal standard to obtain high precision and to compensate for changes in instrument sensitivity and analyte losses in the sampling manifold as described by Bandy and coworkers. The prototype instrument is capable of being deployed on NASA C130, Electra, P3, and DC8 aircraft. After purchasing and taking delivery by June 1994, we assembled the mass spectrometer, data acquisition, and manifold flow control instrumentation in electronic racks and performed tests.

  6. Co-ordination of physiological and morphological responses of stomata to elevated [CO2] in vascular plants.

    PubMed

    Haworth, Matthew; Elliott-Kingston, Caroline; McElwain, Jennifer C

    2013-01-01

    Plant stomata display a wide range of short-term behavioural and long-term morphological responses to atmospheric carbon dioxide concentration ([CO(2)]). The diversity of responses suggests that plants may have different strategies for controlling gas exchange, yet it is not known whether these strategies are co-ordinated in some way. Here, we test the hypothesis that there is co-ordination of physiological (via aperture change) and morphological (via stomatal density change) control of gas exchange by plants. We examined the response of stomatal conductance (G(s)) to instantaneous changes in external [CO(2)] (C(a)) in an evolutionary cross-section of vascular plants grown in atmospheres of elevated [CO(2)] (1,500 ppm) and sub-ambient [O(2)] (13.0 %) compared to control conditions (380 ppm CO(2), 20.9 % O(2)). We found that active control of stomatal aperture to [CO(2)] above current ambient levels was not restricted to angiosperms, occurring in the gymnosperms Lepidozamia peroffskyana and Nageia nagi. The angiosperm species analysed appeared to possess a greater respiratory demand for stomatal movement than gymnosperm species displaying active stomatal control. Those species with little or no control of stomatal aperture (termed passive) to C(a) were more likely to exhibit a reduction in stomatal density than species with active stomatal control when grown in atmospheres of elevated [CO(2)]. The relationship between the degree of stomatal aperture control to C(a) above ambient and the extent of any reduction in stomatal density may suggest the co-ordination of physiological and morphological responses of stomata to [CO(2)] in the optimisation of water use efficiency. This trade-off between stomatal control strategies may have developed due to selective pressures exerted by the costs associated with passive and active stomatal control.

  7. Mars oxygen production system design

    NASA Technical Reports Server (NTRS)

    Cotton, Charles E.; Pillow, Linda K.; Perkinson, Robert C.; Brownlie, R. P.; Chwalowski, P.; Carmona, M. F.; Coopersmith, J. P.; Goff, J. C.; Harvey, L. L.; Kovacs, L. A.

    1989-01-01

    The design and construction phase is summarized of the Mars oxygen demonstration project. The basic hardware required to produce oxygen from simulated Mars atmosphere was assembled and tested. Some design problems still remain with the sample collection and storage system. In addition, design and development of computer compatible data acquisition and control instrumentation is ongoing.

  8. Mars oxygen production system design

    NASA Technical Reports Server (NTRS)

    1988-01-01

    This report summarizes the design and construction of the Mars oxygen demonstration project. The basic hardware required to produce oxygen from simulated Mars atmosphere has been assembled and tested. Some design problems still remain with the sample collection and storage system. In addition, design and development of computer data acquisition and control instrumentation is continuing.

  9. The management of aircraft passenger survival in fire.

    PubMed

    Trimble, E J

    1996-12-31

    The prime factors influencing survivability from 10 major fire-related public transport aircraft accidents were assessed. Regulatory requirements were assessed against derived criteria and alternate concepts evaluated to identify a preferred strategy for enhanced survival; the provision of passenger protective breathing equipment (PPBE) was part of the twin strategy selected. PPBE tests conducted by the UK Air Accidents Investigation Branch using lung simulators and semi-controlled complex challenge combustion atmospheres generated from defined mixtures of cabin interior materials indicated that Hopcalite filters could provide satisfactory protection against carbon monoxide, hydrogen cyanide, hydrogen fluoride, hydrogen chloride, nitrogen oxides, sulphur dioxide, ammonia, acrolein, and other hydrocarbon compounds, for periods up to 30 min. Filtered levels of carbon dioxide (CO2) could be maintained within a 5% limit (inhaled atmosphere + dead space) against such atmospheres containing up to 4% CO2. Concentrations of oxygen downstream from the filters were up to some 1.0% above that present in the challenge atmospheres. Separate lung simulator tests on breathable gas (oxygen) hoods indicated that satisfactory respiratory protection could be provided for periods of up to 31 min. A possible filter modification of the passenger oxygen mask concept is discussed. It is recommended that research should be emphasized on the development of a means (e.g. PPBE) for providing in-flight smoke protection for passengers.

  10. 49 CFR 192.481 - Atmospheric corrosion control: Monitoring.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Atmospheric corrosion control: Monitoring. 192.481... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Requirements for Corrosion Control § 192.481 Atmospheric corrosion control: Monitoring. (a) Each operator must inspect each pipeline...

  11. Mimicking Mars: A vacuum simulation chamber for testing environmental instrumentation for Mars exploration

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

    Sobrado, J. M., E-mail: sobradovj@inta.es; Martín-Soler, J.; Martín-Gago, J. A.

    We have built a Mars environmental simulation chamber, designed to test new electromechanical devices and instruments that could be used in space missions. We have developed this environmental system aiming at validating the meteorological station Rover Environment Monitoring Station of NASA's Mars Science Laboratory mission currently installed on Curiosity rover. The vacuum chamber has been built following a modular configuration and operates at pressures ranging from 1000 to 10{sup −6} mbars, and it is possible to control the gas composition (the atmosphere) within this pressure range. The device (or sample) under study can be irradiated by an ultraviolet source andmore » its temperature can be controlled in the range from 108 to 423 K. As an important improvement with respect to other simulation chambers, the atmospheric gas into the experimental chamber is cooled at the walls by the use of liquid-nitrogen heat exchangers. This chamber incorporates a dust generation mechanism designed to study Martian-dust deposition while modifying the conditions of temperature, and UV irradiated.« less

  12. Influence of modified atmosphere packaging on the shelf life of prebaked pizza dough with and without preservative added.

    PubMed

    Rodríguez, Valle; Medina, Luis; Jordano, Rafael

    2003-04-01

    The possible effect of different modified atmospheres on the shelf life of prebaked pizza dough, with and without added calcium propionate, was investigated. Three packaging atmospheres were tested: 20% CO2: 80% N2, 50% CO2: 50% N2, 100% CO2, and air (control). Samples were examined daily for visible mold growth and analysed after 2, 8, 17 and 31 days throughout storage (15-20 degrees C and 54-65% relative humidity, RH) for changes in gaseous composition, pH and microbial populations (mesophilic aerobic and anaerobic bacteria, lactic acid bacteria (LAB), and yeasts and molds). Microbiological results showed that molds had a greater sensitivity to CO2 than bacteria and yeasts. Products containing calcium propionate did not show mold growth throughout storage (31 days) when packaged in air or in CO2-enriched atmospheres (20, 50 and 100%). However, in pizza dough without preservative (calcium propionate), mold growth was evident after 7 days, except under 100% CO2 atmosphere (13 days) regardless of the packaging atmosphere. From these results we conclude that the addition of calcium propionate had more and decisive influence on the shelf life extension of prebaked pizza dough.

  13. Doppler lidar studies of atmospheric wind field dynamics

    NASA Technical Reports Server (NTRS)

    Hardesty, R. M.; Post, M. J.; Lawrence, T. R.; Hall, F. F., Jr.

    1986-01-01

    For the past 5 years the Wave Propagation Lab. has operated a pulsed CO2 Doppler lidar system to evaluate coherent laser radar technology and to investigate applications of the technique in atmospheric research. The capability of the system to provide measurements of atmospheric winds, backscatter, and water vapor has been extensively studied over this period. Because Doppler lidar can measure atmospheric wind structure in the clear air without degradation by terrain features, it offers a unique capability as a research tool for studies of many transient or local scale atmospheric events. This capability was demonstrated in recent field experiments near Boulder, Colo. and Midland, Tex., in which the lidar clearly depicted the wind field structure associated with several types of phenomena, including thunderstorm microbursts, valley drainage flow, and passage of a dryline front. To improve sensitivity during the periods of low aerosol backscatter, the system has recently been upgraded with new transmitter/receiver hardware. The upgraded system, which transmit 2 J per pulse of output energy at a rate of 50 Hz and incorporates computer control for automated operation, underwent calibration testing during the spring of 1986.

  14. Recent developments with the Mars Observer Camera graphite/epoxy structure

    NASA Astrophysics Data System (ADS)

    Telkamp, Arthur R.

    1992-09-01

    The Mars Observer Camera (MOC) is one of the instruments aboard the Mars Observer Spacecraft to be launched not later than September 1992, whose mission is to geologically and climatologically map the Martian surface and atmosphere over a period of one Martian year. This paper discusses the events in the development of MOC that took place in the past two years, with special attention given to the implementation of thermal blankets, shields, and thermal control paints to limit solar absorption while controlling stray light; vibration testing of Flight Unit No.1; and thermal expansion testing. Results are presented of thermal-vac testing Flight Unit No. 1. It was found that, although the temperature profiles were as predicted, the thermally-induced focus displacements were not.

  15. 42 CFR Appendix - Tables to Subpart I of Part 84

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Test condition Test atmosphere Gas or vapor Concentration (parts per million) Flow rate (liters per... indicated penetration. 2 Relative humidity of test atmosphere will be 95 ±3pct; temperature of test atmosphere will be 25 ±2.5 °C. 3 Maximum allowable CO penetration will be 385 cm 3 during the minimum life...

  16. 42 CFR Appendix - Tables to Subpart I of Part 84

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Test condition Test atmosphere Gas or vapor Concentration (parts per million) Flow rate (liters per... indicated penetration. 2 Relative humidity of test atmosphere will be 95 ±3pct; temperature of test atmosphere will be 25 ±2.5 °C. 3 Maximum allowable CO penetration will be 385 cm 3 during the minimum life...

  17. 42 CFR Appendix - Tables to Subpart I of Part 84

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Test condition Test atmosphere Gas or vapor Concentration (parts per million) Flow rate (liters per... indicated penetration. 2 Relative humidity of test atmosphere will be 95 ±3pct; temperature of test atmosphere will be 25 ±2.5 °C. 3 Maximum allowable CO penetration will be 385 cm 3 during the minimum life...

  18. 49 CFR 195.583 - What must I do to monitor atmospheric corrosion control?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false What must I do to monitor atmospheric corrosion... monitor atmospheric corrosion control? (a) You must inspect each pipeline or portion of pipeline that is exposed to the atmosphere for evidence of atmospheric corrosion, as follows: If the pipeline islocated...

  19. 49 CFR 195.583 - What must I do to monitor atmospheric corrosion control?

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false What must I do to monitor atmospheric corrosion... monitor atmospheric corrosion control? (a) You must inspect each pipeline or portion of pipeline that is exposed to the atmosphere for evidence of atmospheric corrosion, as follows: If the pipeline islocated...

  20. 49 CFR 195.583 - What must I do to monitor atmospheric corrosion control?

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false What must I do to monitor atmospheric corrosion... monitor atmospheric corrosion control? (a) You must inspect each pipeline or portion of pipeline that is exposed to the atmosphere for evidence of atmospheric corrosion, as follows: If the pipeline islocated...

  1. Remembrance of phases past: An autoregressive method for generating realistic atmospheres in simulations

    NASA Astrophysics Data System (ADS)

    Srinath, Srikar; Poyneer, Lisa A.; Rudy, Alexander R.; Ammons, S. M.

    2014-08-01

    The advent of expensive, large-aperture telescopes and complex adaptive optics (AO) systems has strengthened the need for detailed simulation of such systems from the top of the atmosphere to control algorithms. The credibility of any simulation is underpinned by the quality of the atmosphere model used for introducing phase variations into the incident photons. Hitherto, simulations which incorporate wind layers have relied upon phase screen generation methods that tax the computation and memory capacities of the platforms on which they run. This places limits on parameters of a simulation, such as exposure time or resolution, thus compromising its utility. As aperture sizes and fields of view increase the problem will only get worse. We present an autoregressive method for evolving atmospheric phase that is efficient in its use of computation resources and allows for variability in the power contained in frozen flow or stochastic components of the atmosphere. Users have the flexibility of generating atmosphere datacubes in advance of runs where memory constraints allow to save on computation time or of computing the phase at each time step for long exposure times. Preliminary tests of model atmospheres generated using this method show power spectral density and rms phase in accordance with established metrics for Kolmogorov models.

  2. Mutagenic atmospheres resulting from the photooxidation of aromatic hydrocarbon and NOx mixtures

    NASA Astrophysics Data System (ADS)

    Riedel, Theran P.; DeMarini, David M.; Zavala, Jose; Warren, Sarah H.; Corse, Eric W.; Offenberg, John H.; Kleindienst, Tadeusz E.; Lewandowski, Michael

    2018-04-01

    Although many volatile organic compounds (VOCs) are regulated to limit air pollution and the consequent health effects, the photooxidation products generally are not. Thus, we examined the mutagenicity in Salmonella TA100 of photochemical atmospheres generated in a steady-state atmospheric simulation chamber by irradiating mixtures of single aromatic VOCs, NOx, and ammonium sulfate seed aerosol in air. The 10 VOCs examined were benzene; toluene; ethylbenzene; o-, m-, and p-xylene; 1,2,4- and 1,3,5-trimethylbenzene; m-cresol; and naphthalene. Salmonella were exposed at the air-agar interface to the generated atmospheres for 1, 2, 4, 8, or 16 h. Dark-control exposures produced non-mutagenic atmospheres, illustrating that the gas-phase precursor VOCs were not mutagenic at the concentrations tested. Under irradiation, all but m-cresol and naphthalene produced mutagenic atmospheres, with potencies ranging from 2.0 (p-xylene) to 11.4 (ethylbenzene) revertants m3 mgC-1 h-1. The mutagenicity was due exclusively to direct-acting late-generation products of the photooxidation reactions. Gas-phase chemical analysis showed that a number of oxidized organic chemical species enhanced during the irradiated exposure experiments correlated (r ≥ 0.81) with the mutagenic potencies of the atmospheres. Molecular formulas assigned to these species indicated that they likely contained peroxy acid, aldehyde, alcohol, and other functionalities.

  3. Controllable synthesizing DLC nano structures as a super hydrophobic layer on cotton fabric using a low-cost ethanol electrospray-assisted atmospheric plasma jet.

    PubMed

    Sohbatzadeh, F; Eshghabadi, M; Mohsenpour, T

    2018-06-29

    The surface modification of cotton samples was carried out using a liquid (ethanol) electrospray-assisted atmospheric pressure plasma jet. X-ray photoelectron spectroscopy (XPS) and Raman analysis confirmed the successful deposition of diamond like carbon (DLC) nano structures on the cotton surface. The super hydrophobic state of the samples was probed by contact angle measurements. The water repellency of the layers was tuned by controlling the voltage applied to the electrospray electrode. An investigation of the morphological and chemical structures of the samples by field emission scanning microscopy, atomic force microscopy (AFM) and XPS indicated that the physical shape, distribution and amorphization of the DLC structures were successfully adjusted and improved by applying a voltage to the electrospray electrode. Finally wash durability of the best sample was tested for 35 cycles. In this work, the use of a well-developed atmospheric pressure plasma jet for DLC nano structures deposition can enable a promising environmentally friendly and low-cost approach for modifying cotton fabrics for super water-repellent fabric applications.

  4. Controllable synthesizing DLC nano structures as a super hydrophobic layer on cotton fabric using a low-cost ethanol electrospray-assisted atmospheric plasma jet

    NASA Astrophysics Data System (ADS)

    Sohbatzadeh, F.; Eshghabadi, M.; Mohsenpour, T.

    2018-06-01

    The surface modification of cotton samples was carried out using a liquid (ethanol) electrospray-assisted atmospheric pressure plasma jet. X-ray photoelectron spectroscopy (XPS) and Raman analysis confirmed the successful deposition of diamond like carbon (DLC) nano structures on the cotton surface. The super hydrophobic state of the samples was probed by contact angle measurements. The water repellency of the layers was tuned by controlling the voltage applied to the electrospray electrode. An investigation of the morphological and chemical structures of the samples by field emission scanning microscopy, atomic force microscopy (AFM) and XPS indicated that the physical shape, distribution and amorphization of the DLC structures were successfully adjusted and improved by applying a voltage to the electrospray electrode. Finally wash durability of the best sample was tested for 35 cycles. In this work, the use of a well-developed atmospheric pressure plasma jet for DLC nano structures deposition can enable a promising environmentally friendly and low-cost approach for modifying cotton fabrics for super water-repellent fabric applications.

  5. The hydrodynamics of plant spacing distance: Optimizing consumptive and non-consumptive water use in water-limited environments

    NASA Astrophysics Data System (ADS)

    Trautz, A.; Illangasekare, T. H.; Rodriguez-Iturbe, I.; Howington, S. E.

    2017-12-01

    The availability of soil moisture in water-stressed environments is one of the primary factors controlling plant performance and overall plant community productivity and structure. The minimization of non-consumptive water loss, or water not utilized by plants (i.e. consumptive use), to bare soil evaporation is a key plant survival strategy and important agricultural consideration. Competitive (negative) and facilitative (positive) interactions between individual plants play a pivotal role in controlling the local coupled soil-plant-atmosphere hydrodynamics that affect both consumptive and non-consumptive water use. The strength of these two types of interactions vary with spacing distance between individuals. In a recent PNAS publication, we hypothesized that there exists a quantifiable spacing distance between plants that optimizes the balance between competition and facilitation, and hence maximizes water conservation. This study expands upon on our previous work, for which only a subset of the data generated was used, through the development and testing of a numerical model that can test a conceptual model we presented. The model simulates soil-plant-atmosphere continuum heat and mass transfer hydrodynamics, taking into account the complex feedbacks that exist between the near-surface atmosphere, subsurface, and plants. This model has been developed to explore the combined effects of subsurface competition and micro-climatic amelioration (i.e., facilitation) on local soil moisture redistribution and fluxes in the context of water-stressed environments that experienced sustained winds. We believe the results have the potential to provide new insights into climatological, ecohydrological, and hydrological problems pertaining to: the extensively used and much debated stress-gradient hypothesis, plant community population self-organization, agricultural best practices (e.g., water management), and spatial heterogeneity of land-atmosphere fluxes.

  6. Design and evaluation of combustors for reducing aircraft engine pollution

    NASA Technical Reports Server (NTRS)

    Jones, R. E.; Grobman, J.

    1973-01-01

    Various techniques and test results are briefly described and referenced for detail. The effort arises from the increasing concern for the measurement and control of emissions from gas turbine engines. The greater part of this research is focused on reducing the oxides of nitrogen formed during takeoff and cruise in both advanced CTOL, high pressure ratio engines, and advanced supersonic aircraft engines. The experimental approaches taken to reduce oxides of nitrogen emissions include the use of: multizone combustors incorporating reduced dwell time, fuel-air premixing, air atomization, fuel prevaporization, water injection, and gaseous fuels. In the experiments conducted to date, some of these techniques were more successful than others in reducing oxides of nitrogen emissions. Tests are being conducted on full-annular combustors at pressures up to 6 atmospheres and on combustor segments at pressures up to 30 atmospheres.

  7. A general circulation model study of the effects of faster rotation rate, enhanced CO2 concentration, and reduced solar forcing: Implications for the faint young sun paradox

    NASA Technical Reports Server (NTRS)

    Jenkins, Gregory S.

    1993-01-01

    Solar energy at the top of the atmosphere (solar constant), rotation rate, and carbon dioxide (CO2) may have varied significantly over Earth's history, especially during the earliest times. The sensitivity of a general circulation model to faster rotation, enhanced CO2 concentration, and reduced solar constant is presented. The control simulation of this study has a solar constant reduced by 10% the present amount, zero land fraction using a swamp ocean surface, CO2 concentrations of 330 ppmv, present-day rotation rate, and is integrated under mean diurnal and seasonal solar forcing. Four sensitivity test are performed under zero land fraction and reduced solar constant conditions by varying the earth's rotation rate atmospheric CO2 concentration and solar constant. The global mean sea surface temperatures (SSTs) compared to the control simulation: were 6.6 K to 12 K higher than the control's global mean temperature of 264.7 K. Sea ice is confined to higher latitudes in each experiment compared to the control, with ice-free areas equatorward of the subtropics. The warm SSTs are associated with a 20% reduction in clouds for the rotation rate experiments and higher CO2 concentrations in the other experiments. These results are in contrast to previous studies that have used energy balance and radiative convective models. Previous studies required a much larger atmospheric CO2 increase to prevent an ice-covered Earth. The results of the study, suggest that because of its possible feedback with clouds, the general circulation of the atmosphere should be taken into account in understanding the climate of early Earth. While higher CO2 concentrations are likely in view of the results, very large atmospheric CO2 concentrations may not be necessary to counterbalance the lower solar constant that existed early in Earth's history.

  8. 222Rn+220Rn monitoring by alpha spectrometry.

    PubMed

    Buompane, R; Roca, V; Sabbarese, C; Pugliese, M; Quarto, M; Mattone, C

    2014-07-01

    Controlled 222Rn+220Rn mixed atmospheres have been realised introducing calibrated sources in a stainless steel chamber. An electrostatic alpha monitor internal to the chamber has been used for an accurate discrimination of alpha peaks due to the products of the two isotopes. In the chamber, different specific activities are achieved in order to test the response of the internal reference instrument and to evaluate the possible interferences due to contemporary presence of both radon isotopes. Results show that: (i) the atmospheres are very stable, (ii) the monitor is adequate for their control because the various alpha lines are well evaluated and (iii) using Tyvek® filter, the efficiency of monitor is stable and constant vs. activity. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. In Vitro Exposures in Diesel Exhaust Atmospheres: Resuspension of PM from Filters Verses Direct Deposition of PM from Air

    PubMed Central

    Lichtveld, Kim M.; Ebersviller, Seth M.; Sexton, Kenneth G.; Vizuete, William; Jaspers, Ilona; Jeffries, Harvey E.

    2012-01-01

    One of the most widely used in vitro particulate matter (PM) exposures methods is the collection of PM on filters, followed by resuspension in a liquid medium, with subsequent addition onto a cell culture. To avoid disruption of equilibria between gases and PM, we have developed a direct in vitro sampling and exposure method (DSEM) capable of PM-only exposures. We hypothesize that the separation of phases and post-treatment of filter-collected PM significantly modifies the toxicity of the PM compared to direct deposition, resulting in a distorted view of the potential PM health effects. Controlled test environments were created in a chamber that combined diesel exhaust with an urban-like mixture. The complex mixture was analyzed using both the DSEM and concurrently-collected filter samples. The DSEM showed that PM from test atmospheres produced significant inflammatory response, while the resuspension exposures at the same exposure concentration did not. Increasing the concentration of resuspended PM sixteen times was required to yield measurable IL-8 expression. Chemical analysis of the resuspended PM indicated a total absence of carbonyl compounds compared to the test atmosphere during the direct-exposures. Therefore, collection and resuspension of PM into liquid modifies its toxicity and likely leads to underestimating toxicity. PMID:22834915

  10. Control of Penicillium martensii Development and Penicillic Acid Production by Atmospheric Gases and Temperatures

    PubMed Central

    Lillehoj, E. B.; Milburn, M. S.; Ciegler, A.

    1972-01-01

    The effects of various gaseous environments and temperatures on development of Penicillium martensii NRRL 3612 and production of penicillic acid (PA) were determined. Accumulation of PA in mold-inoculated corn was measured following incubation under air; 20% CO2, 20% O2, 60% N2; 40% CO2, 20% O2, 40% N2; and 60% CO2, 20% O2, 20% N2. Although reduced temperature initially inhibited PA production, at the end of the trial the largest quantity of PA (120 μg/g of corn) was found in air-incubated corn at the lowest test temperature (5 C). Atmospheres enriched with 60% CO2 reduced PA accumulation below a detectable level at 5 and 10 C after a 4-week incubation period. Spore germination tests were carried out in a liquid growth medium incubated for 16 hr under several test conditions. Germ tube outgrowth at 30 C ranged from 36% in air to 2% in 60% CO2, whereas no germination was observed in CO2-enriched gases at 10 C. When spore respiration rates were measured in air and O2 in a liquid growth medium, complete removal of CO2 from the reaction atmosphere did not reduce O2 uptake. PMID:5071649

  11. Management of the Atmosphere Resource Recovery and Environmental Monitoring Project

    NASA Technical Reports Server (NTRS)

    Roman, Monsi; Perry, Jay; Howard, David

    2013-01-01

    The Advanced Exploration Systems Program's Atmosphere Resource Recovery and Environmental Monitoring (ARREM) project is working to further optimize atmosphere revitalization and environmental monitoring system architectures. This paper discusses project management strategies that tap into skill sets across multiple engineering disciplines, projects, field centers, and industry to achieve the project success. It is the project's objective to contribute to system advances that will enable sustained exploration missions beyond Lower Earth Orbit (LEO) and improve affordability by focusing on the primary goals of achieving high reliability, improving efficiency, and reducing dependence on ground-based logistics resupply. Technology demonstrations are achieved by infusing new technologies and concepts with existing developmental hardware and operating in a controlled environment simulating various crewed habitat scenarios. The ARREM project's strengths include access to a vast array of existing developmental hardware that perform all the vital atmosphere revitalization functions, exceptional test facilities to fully evaluate system performance, and a well-coordinated partnering effort among the NASA field centers and industry partners to provide the innovative expertise necessary to succeed.

  12. Experimental Investigation of Soil and Atmospheric Conditions on the Momentum, Mass, and Thermal Boundary Layers Above the Land Atmosphere Interface

    NASA Astrophysics Data System (ADS)

    Trautz, A.; Smits, K. M.; Illangasekare, T. H.; Schulte, P.

    2014-12-01

    The purpose of this study is to investigate the impacts of soil conditions (i.e. soil type, saturation) and atmospheric forcings (i.e. velocity, temperature, relative humidity) on the momentum, mass, and temperature boundary layers. The atmospheric conditions tested represent those typically found in semi-arid and arid climates and the soil conditions simulate the three stages of evaporation. The data generated will help identify the importance of different soil conditions and atmospheric forcings with respect to land-atmospheric interactions which will have direct implications on future numerical studies investigating the effects of turbulent air flow on evaporation. The experimental datasets generated for this study were performed using a unique climate controlled closed-circuit wind tunnel/porous media facility located at the Center for Experimental Study of Subsurface Environmental Processes (CESEP) at the Colorado School of Mines. The test apparatus consisting of a 7.3 m long porous media tank and wind tunnel, were outfitted with a sensor network to carefully measure wind velocity, air and soil temperature, relative humidity, soil moisture, and soil air pressure. Boundary layer measurements were made between the heights of 2 and 500 mm above the soil tank under constant conditions (i.e. wind velocity, temperature, relative humidity). The soil conditions (e.g. soil type, soil moisture) were varied between datasets to analyze their impact on the boundary layers. Experimental results show that the momentum boundary layer is very sensitive to the applied atmospheric conditions and soil conditions to a much less extent. Increases in velocity above porous media leads to momentum boundary layer thinning and closely reflect classical flat plate theory. The mass and thermal boundary layers are directly dependent on both atmospheric and soil conditions. Air pressure within the soil is independent of atmospheric temperature and relative humidity - wind velocity and soil moisture effects were observed. This data provides important insight into future work of accurately modeling the exchange processes associated with evaporation under various turbulent atmospheric conditions.

  13. International Space Station Atmosphere Control and Supply, Atmosphere Revitalization, and Water Recovery and Management Subsystem - Verification for Node 1

    NASA Technical Reports Server (NTRS)

    Williams, David E.

    2007-01-01

    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 nominal operation of the Node 1 ACS, AR, and WRM design and detailed Element Verification methodologies utilized during the Qualification phase for Node 1.

  14. Test Results for Entry Guidance Methods for Space Vehicles

    NASA Technical Reports Server (NTRS)

    Hanson, John M.; Jones, Robert E.

    2004-01-01

    There are a number of approaches to advanced guidance and control that have the potential for achieving the goals of significantly increasing reusable launch vehicle (or any space vehicle that enters an atmosphere) safety and reliability, and reducing the cost. This paper examines some approaches to entry guidance. An effort called Integration and Testing of Advanced Guidance and Control Technologies has recently completed a rigorous testing phase where these algorithms faced high-fidelity vehicle models and were required to perform a variety of representative tests. The algorithm developers spent substantial effort improving the algorithm performance in the testing. This paper lists the test cases used to demonstrate that the desired results are achieved, shows an automated test scoring method that greatly reduces the evaluation effort required, and displays results of the tests. Results show a significant improvement over previous guidance approaches. The two best-scoring algorithm approaches show roughly equivalent results and are ready to be applied to future vehicle concepts.

  15. A Flight Dynamics Perspective of the Orion Pad Abort One Flight Test

    NASA Technical Reports Server (NTRS)

    Idicula, Jinu; Williams-Hayes, Peggy S.; Stillwater, Ryan; Yates, Max

    2009-01-01

    The Orion Crew Exploration Vehicle is America s next generation of human rated spacecraft. The Orion Launch Abort System will take the astronauts away from the exploration vehicle in the event of an aborted launch. The pad abort mode of the Launch Abort System will be flight-tested in 2009 from the White Sands Missile Range in New Mexico. This paper examines some of the efforts currently underway at the NASA Dryden Flight Research Center by the Controls & Dynamics group in preparation for the flight test. The concept of operation for the pad abort flight is presented along with an overview of the guidance, control and navigation systems. Preparations for the flight test, such as hardware testing and development of the real-time displays, are examined. The results from the validation and verification efforts for the aerodynamic and atmospheric models are shown along with Monte Carlo analysis results.

  16. KENNEDY SPACE CENTER, FLA. - Dr. Paul Hintze (left) explains to Center Director Jim Kennedy a project he is working at the KSC Beach Corrosion Test Site. Hitze is doing post-graduate work for the National Research Council. The test facility site was established in the 1960s and has provided more than 30 years of historical information on the long-term performance of many materials in use at KSC and other locations around the world. Located 100 feet from the Atlantic Ocean approximately 1 mile south of the Space Shuttle launch sites, the test facility includes an atmospheric exposure site, a flowing seawater exposure site, and an on-site electrochemistry laboratory and monitoring station. The beach laboratory is used to conduct real-time corrosion experiments and provides for the remote monitoring of surrounding weather conditions. The newly added flowing seawater immersion facility provides for the immersion testing of materials and devices under controlled conditions.

    NASA Image and Video Library

    2003-08-21

    KENNEDY SPACE CENTER, FLA. - Dr. Paul Hintze (left) explains to Center Director Jim Kennedy a project he is working at the KSC Beach Corrosion Test Site. Hitze is doing post-graduate work for the National Research Council. The test facility site was established in the 1960s and has provided more than 30 years of historical information on the long-term performance of many materials in use at KSC and other locations around the world. Located 100 feet from the Atlantic Ocean approximately 1 mile south of the Space Shuttle launch sites, the test facility includes an atmospheric exposure site, a flowing seawater exposure site, and an on-site electrochemistry laboratory and monitoring station. The beach laboratory is used to conduct real-time corrosion experiments and provides for the remote monitoring of surrounding weather conditions. The newly added flowing seawater immersion facility provides for the immersion testing of materials and devices under controlled conditions.

  17. A flight-test and simulation evaluation of the longitudinal final approach and landing performance of an automatic system for a light wing loading STOL aircraft

    NASA Technical Reports Server (NTRS)

    Brown, S. C.; Hardy, G. H.; Hindson, W. S.

    1983-01-01

    As part of a comprehensive flight-test program of STOL operating systems for the terminal area, an automatic landing system was developed and evaluated for a light wing loading turboprop aircraft. The aircraft utilized an onboard advanced digital avionics system. Flight tests were conducted at a facility that included a STOL runway site with a microwave landing system. Longitudinal flight-test results were presented and compared with available (basically CTOL) criteria. These comparisons were augmented by results from a comprehensive simulation of the controlled aircraft which included representations of navigation errors that were encountered in flight and atmospheric disturbances. Acceptable performance on final approach and at touchdown was achieved by the autoland (automatic landing) system for the moderate winds and turbulence conditions encountered in flight. However, some touchdown performance goals were marginally achieved, and simulation results suggested that difficulties could be encountered in the presence of more extreme atmospheric conditions. Suggestions were made for improving performance under those more extreme conditions.

  18. Nuclear Rocket Test Facility Decommissioning Including Controlled Explosive Demolition of a Neutron-Activated Shield Wall

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

    Michael Kruzic

    2007-09-01

    Located in Area 25 of the Nevada Test Site, the Test Cell A Facility was used in the 1960s for the testing of nuclear rocket engines, as part of the Nuclear Rocket Development Program. The facility was decontaminated and decommissioned (D&D) in 2005 using the Streamlined Approach For Environmental Restoration (SAFER) process, under the Federal Facilities Agreement and Consent Order (FFACO). Utilities and process piping were verified void of contents, hazardous materials were removed, concrete with removable contamination decontaminated, large sections mechanically demolished, and the remaining five-foot, five-inch thick radiologically-activated reinforced concrete shield wall demolished using open-air controlled explosive demolitionmore » (CED). CED of the shield wall was closely monitored and resulted in no radiological exposure or atmospheric release.« less

  19. Accelerated Test Method for Corrosion Protective Coatings Project

    NASA Technical Reports Server (NTRS)

    Falker, John; Zeitlin, Nancy; Calle, Luz

    2015-01-01

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

  20. Disturbance observer based model predictive control for accurate atmospheric entry of spacecraft

    NASA Astrophysics Data System (ADS)

    Wu, Chao; Yang, Jun; Li, Shihua; Li, Qi; Guo, Lei

    2018-05-01

    Facing the complex aerodynamic environment of Mars atmosphere, a composite atmospheric entry trajectory tracking strategy is investigated in this paper. External disturbances, initial states uncertainties and aerodynamic parameters uncertainties are the main problems. The composite strategy is designed to solve these problems and improve the accuracy of Mars atmospheric entry. This strategy includes a model predictive control for optimized trajectory tracking performance, as well as a disturbance observer based feedforward compensation for external disturbances and uncertainties attenuation. 500-run Monte Carlo simulations show that the proposed composite control scheme achieves more precise Mars atmospheric entry (3.8 km parachute deployment point distribution error) than the baseline control scheme (8.4 km) and integral control scheme (5.8 km).

  1. Guidance and Control of an Autonomous Soaring UAV

    NASA Technical Reports Server (NTRS)

    Allen, Michael J.; Lin, Victor

    2007-01-01

    Thermals caused by convection in the lower atmosphere are commonly used by birds and glider pilots to extend flight duration, increase cross-country speed, improve range, or simply to conserve energy. Uninhabited Aerial Vehicles (UAVs) can also increase performance and reduce energy consumption by exploiting atmospheric convection. An autonomous soaring research project was conducted at the NASA Dryden Flight Research Center to evaluate the concept through flight test of an electric-powered motorglider with a wingspan of 4.27 m (14 ft). The UAV's commercial autopilot software was modified to include outer-loop soaring guidance and control. The aircraft total energy state was used to detect and soar within thermals. Estimated thermal size and position were used to calculate guidance commands for soaring flight. Results from a total of 23 thermal encounters show good performance of the guidance and control algorithms to autonomously detect and exploit thermals. The UAV had an average climb of 172 m (567 ft) during these encounters.

  2. Guidance and Control of an Autonomous Soaring UAV

    NASA Technical Reports Server (NTRS)

    Allen, Michael J.

    2007-01-01

    Thermals caused by convection in the lower atmosphere are commonly used by birds and glider pilots to extend flight duration, increase cross-country speed, improve range, or simply to conserve energy. Uninhabited Aerial Vehicles (UAVs) can also increase performance and reduce energy consumption by exploiting atmospheric convection. An autonomous soaring research project was conducted at the NASA Dryden Flight Research Center to evaluate the concept through flight test of an electric-powered motor-glider with a wingspan of 4.27 m (14 ft). The UAV's commercial autopilot software was modified to include outer-loop soaring guidance and control. The aircraft total energy state was used to detect and soar within thermals. Estimated thermal size and position were used to calculate guidance commands for soaring flight. Results from a total of 23 thermal encounters show good performance of the guidance and control algorithms to autonomously detect and exploit thermals. The UAV had an average climb of 172 m (567 ft) during these encounters.

  3. Atmospheric Measurements for Flight Test at NASAs Neil A. Armstrong Flight Research Center

    NASA Technical Reports Server (NTRS)

    Teets, Edward H.

    2016-01-01

    Information enclosed is to be shared with students of Atmospheric Sciences, Engineering and High School STEM programs. Information will show the relationship between atmospheric Sciences and aeronautical flight testing.

  4. Shuttle Orbiter Atmospheric Revitalization Pressure Control Subsystem

    NASA Technical Reports Server (NTRS)

    Walleshauser, J. J.; Ord, G. R.; Prince, R. N.

    1982-01-01

    The Atmospheric Revitalization Pressure Control Subsystem (ARPCS) provides oxygen partial pressure and total pressure control for the habitable atmosphere of the Shuttle for either a one atmosphere environment or an emergency 8 PSIA mode. It consists of a Supply Panel, Control Panel, Cabin Pressure Relief Valves and Electronic Controllers. The panels control and monitor the oxygen and nitrogen supplies. The cabin pressure relief valves protect the habitable environment from overpressurization. Electronic controllers provide proper mixing of the two gases. This paper describes the ARPCS, addresses the changes in hardware that have occurred since the inception of the program; the performance of this subsystem during STS-1 and STS-2; and discusses future operation modes.

  5. Testing of an Amine-Based Pressure-Swing System for Carbon Dioxide and Humidity Control

    NASA Technical Reports Server (NTRS)

    Lin, Amy; Smith, Frederick; Sweterlitsch, Jeffrey; Graf, John; Nalette, Tim; Papale, William; Campbell, Melissa; Lu, Sao-Dung

    2007-01-01

    In a crewed spacecraft environment, atmospheric carbon dioxide (CO2) and moisture control is crucial. Hamilton Sundstrand has developed a stable and efficient amine-based CO2 and water vapor sorbent, SA9T, that is well-suited for use in a spacecraft environment. The sorbent is efficiently packaged in pressure-swing regenerable beds that are thermally linked to improve removal efficiency and minimize vehicle thermal loads. Flows are all controlled with a single spool valve. This technology has been baselined for the new Orion spacecraft. However, more data was needed on the operational characteristics of the package in a simulated spacecraft environment. A unit was therefore tested with simulated metabolic loads in a closed chamber at Johnson Space Center during the last third of 2006. Tests were run at a variety of cabin temperatures and with a range of operating conditions varying cycle time, vacuum pressure, air flow rate, and crew activity levels. Results of this testing are presented and potential flight operational strategies discussed.

  6. Engineered Structured Sorbents for the Adsorption of Carbon Dioxide and Water Vapor from Manned Spacecraft Atmospheres: Applications and Testing 2008/2009

    NASA Technical Reports Server (NTRS)

    Howard, David F.; Perry, Jay L.; Knox, James C.; Junaedi, Christian

    2009-01-01

    This paper describes efforts to improve on typical packed beds of sorbent pellets by making use of structured sorbents and alternate bed configurations to improve system efficiency and reliability. The benefits of the alternate configurations include increased structural stability gained by eliminating clay bound zeolite pellets that tend to fluidize and erode, and better thermal control during sorption to increase process efficiency. Test results that demonstrate such improvements are described and presented.

  7. An Examination of the Potential for Conflict in the South Pacific Region.

    DTIC Science & Technology

    1987-03-23

    of atmospheric and water pollution resulting from the tests and extending beyond French Polynesia, the evidence is inconclusive as to whether the tests...COMPLETING FORM 1. REPORT NUMBER 2 : Z S1 0 ;CPIENT’S CATALOG NUMBER 4. ,7JTL d 4ubt ITn of the Potential for Cfic S . TyPE OF REPORT & PERIOD COVERED".Ala...MONITORING AGENCY NAME & ADDRESS(Il different from Controlling Office) , S . SECURITY CLASS. (of this report) ISO. DECL ASSI FICATION DOWNGRADING

  8. Evaluation of messenger plant activator as a preharvest and postharvest treatment of sweet cherry fruit under a controlled atmosphere.

    PubMed

    Akbudak, Bulent; Tezcan, Himmet; Eris, Atilla

    2009-08-01

    The preservation methods as an alternative to chemical control to prevent postharvest quality losses of sweet cherry were examined. The efficacy of preharvest and postharvest messenger (M) treatments on sweet cherry cv. '0900 Ziraat' was tested under a controlled atmosphere in 2004 and 2005. The factors investigated included the separate or combined effect of low oxygen, high carbon dioxide and M on the quality and fungal pathogens of sweet cherries in a normal atmosphere (NA) and in a controlled atmosphere (CA). Cherries were placed at six different atmosphere combinations (0.03%:21% [NA, control], 5%:5%, 10%:5%, 15%:5%, 20%:5% and 25%:5% CO(2):O(2)) at 0°C and 90% relative humidity for up to 8 weeks. Mass values were higher in cherries stored under NA compared with CA. Initial firmness was 1.45 kg and 1.41 kg in fruits without messenger (WM) and in M fruits, respectively; and was measured as 0.30-0.59 kg in WM and 0.57-0.95 kg in M at the end of the trials. The highest acidity and ascorbic acid values were recorded at the end of storage from the fruit stored under CA + M. The CA + M treatment proved the most effective with regard to delaying the maturity and preserving the fruit quality in sweet cherries during storage. Moreover, the CA + M treatments reduced the rotten fruit from 24.06% to 3.80% in cv. '0900 Ziraat'. Better fruit quality was obtained under CA + M compared with NA and CA. The fungi most frequently isolated from sweet cherries were Botrytis cinerea, Penicillium expansum, Monilinia fructicola, Alternaria alternata and Rhizopus stolonifer. It was concluded that sweet cherry cv. '0900 Ziraat' could be stored successfully under CA (20%:5%) + M, and partially under CA (25%:5%) + M, conditions for more than 60 days. Thus, it is recommended that CO(2) levels for sweet cherry storage can be increased above 15% with M.

  9. Fading testbed for free-space optical communications

    NASA Astrophysics Data System (ADS)

    Shrestha, Amita; Giggenbach, Dirk; Mustafa, Ahmad; Pacheco-Labrador, Jorge; Ramirez, Julio; Rein, Fabian

    2016-10-01

    Free-space optical (FSO) communication is a very attractive technology offering very high throughput without spectral regulation constraints, yet allowing small antennas (telescopes) and tap-proof communication. However, the transmitted signal has to travel through the atmosphere where it gets influenced by atmospheric turbulence, causing scintillation of the received signal. In addition, climatic effects like fogs, clouds and rain also affect the signal significantly. Moreover, FSO being a line of sight communication requires precise pointing and tracking of the telescopes, which otherwise also causes fading. To achieve error-free transmission, various mitigation techniques like aperture averaging, adaptive optics, transmitter diversity, sophisticated coding and modulation schemes are being investigated and implemented. Evaluating the performance of such systems under controlled conditions is very difficult in field trials since the atmospheric situation constantly changes, and the target scenario (e.g. on aircraft or satellites) is not easily accessible for test purposes. Therefore, with the motivation to be able to test and verify a system under laboratory conditions, DLR has developed a fading testbed that can emulate most realistic channel conditions. The main principle of the fading testbed is to control the input current of a variable optical attenuator such that it attenuates the incoming signal according to the loaded power vector. The sampling frequency and mean power of the vector can be optionally changed according to requirements. This paper provides a brief introduction to software and hardware development of the fading testbed and measurement results showing its accuracy and application scenarios.

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

    NASA Astrophysics Data System (ADS)

    Mosby, Gregory; Rauscher, Bernard; Kutyrev, Alexander

    2018-01-01

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

  11. Tests of Exoplanet Atmospheric Radiative Transfer Codes

    NASA Astrophysics Data System (ADS)

    Harrington, Joseph; Challener, Ryan; DeLarme, Emerson; Cubillos, Patricio; Blecic, Jasmina; Foster, Austin; Garland, Justin

    2016-10-01

    Atmospheric radiative transfer codes are used both to predict planetary spectra and in retrieval algorithms to interpret data. Observational plans, theoretical models, and scientific results thus depend on the correctness of these calculations. Yet, the calculations are complex and the codes implementing them are often written without modern software-verification techniques. In the process of writing our own code, we became aware of several others with artifacts of unknown origin and even outright errors in their spectra. We present a series of tests to verify atmospheric radiative-transfer codes. These include: simple, single-line line lists that, when combined with delta-function abundance profiles, should produce a broadened line that can be verified easily; isothermal atmospheres that should produce analytically-verifiable blackbody spectra at the input temperatures; and model atmospheres with a range of complexities that can be compared to the output of other codes. We apply the tests to our own code, Bayesian Atmospheric Radiative Transfer (BART) and to several other codes. The test suite is open-source software. We propose this test suite as a standard for verifying current and future radiative transfer codes, analogous to the Held-Suarez test for general circulation models. This work was supported by NASA Planetary Atmospheres grant NX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G.

  12. Influence of atmospheric pressure low-temperature plasma treatment on the shear bond strength between zirconia and resin cement.

    PubMed

    Ito, Yuki; Okawa, Takahisa; Fukumoto, Takahiro; Tsurumi, Akiko; Tatsuta, Mitsuhiro; Fujii, Takamasa; Tanaka, Junko; Tanaka, Masahiro

    2016-10-01

    Zirconia exhibits excellent strength and high biocompatibility in technological applications and it is has therefore been investigated for clinical applications and research. Before setting prostheses, a crown prosthesis inner surface is sandblasted with alumina to remove contaminants and form small cavities. This alumina sandblasting causes stress-induced phase transition of zirconia. Atmospheric-pressure low-temperature plasma has been applied in the dental industry, particularly for adhesives, as a surface treatment to activate the surface energy and remove contaminants. The purpose of this study was to examine the influence of atmospheric-pressure low-temperature plasma treatment on the shear bond strength between zirconia and adhesive resin cement. The surface treatment method was classified into three groups: untreated (Cont group), alumina sandblast treatment (Sb group), and atmospheric-pressure low-temperature plasma treatment (Ps group). Adhesive resin cement was applied to stainless steel and bonded to zirconia. Shear adhesion tests were performed after complete hardening of the cement. Multiple comparisons were performed using a one-way analysis of variance and the Bonferroni method. X-ray diffractometry was used to examine the change in zirconia crystal structure. Statistically significant differences were noted between the control and Sb groups and between the control and Ps groups. In contrast, no statistically significant differences were noted for the Ps and Sb bond strength. Atmospheric-pressure low-temperature plasma treatment did not affect the zirconia crystal structure. Atmospheric-pressure low-temperature plasma treatment improves the bonding strength of adhesive resin cement as effectively as alumina sandblasting, and does not alter the zirconia crystal structure. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  13. Amine Swingbed Payload Testing on ISS

    NASA Technical Reports Server (NTRS)

    Button, Amy B.; Sweterlitsch, Jeffrey J.

    2014-01-01

    One of NASA Johnson Space Center's test articles of the amine-based carbon dioxide (CO2) and water vapor sorbent system known as the CO2 And Moisture Removal Amine Swing-bed, or CAMRAS, was incorporated into a payload on the International Space Station (ISS). The intent of the payload is to demonstrate the spacecraft-environment viability of the core atmosphere revitalization technology baselined for the new Orion vehicle. In addition to the air blower, vacuum connection, and controls needed to run the CAMRAS, the payload incorporates a suite of sensors for scientific data gathering, a water save function, and an air save function. The water save function minimizes the atmospheric water vapor reaching the CAMRAS unit, thereby reducing ISS water losses that are otherwise acceptable, and even desirable, in the Orion environment. The air save function captures about half of the ullage air that would normally be vented overboard every time the cabin air-adsorbing and space vacuum-desorbing CAMRAS beds swap functions. The JSC team conducted 1000 hours of on-orbit Amine Swingbed Payload testing in 2013 and early 2014. This paper presents the basics of the payload's design and history, as well as a summary of the test results, including comparisons with prelaunch testing.

  14. Worldwide dispersion and deposition of radionuclides produced in atmospheric tests.

    PubMed

    Bennett, Burton G

    2002-05-01

    Radionuclides produced in atmospheric nuclear tests were widely dispersed in the global environment. From the many measurements of the concentrations in air and the deposition amounts, much was learned of atmospheric circulation and environmental processes. Based on these results and the reported fission and total yields of individual tests, it has been possible to devise an empirical model of the movement and residence times of particles in the various atmospheric regions. This model, applied to all atmospheric weapons tests, allows extensive calculations of air concentrations and deposition amounts for the entire range of radionuclides produced throughout the testing period. Especially for the shorter-lived fission radionuclides, for which measurement results at the time of the tests are less extensive, a more complete picture of levels and isotope ratios can be obtained, forming a basis for improved dose estimations. The contributions to worldwide fallout can be inferred from individual tests, from tests at specific sites, or by specific countries. Progress was also made in understanding the global hydrological and carbon cycles from the tritium and 14C measurements. A review of the global measurements and modeling results is presented in this paper. In the future, if injections of materials into the atmosphere occur, their anticipated motions and fates can be predicted from the knowledge gained from the fallout experience.

  15. Preliminary analysis of a membrane-based atmosphere-control subsystem

    NASA Technical Reports Server (NTRS)

    Mccray, Scott B.; Newbold, David D.; Ray, Rod; Ogle, Kathryn

    1993-01-01

    Controlled ecological life supprot systems will require subsystems for maintaining the consentrations of atmospheric gases within acceptable ranges in human habitat chambers and plant growth chambers. The goal of this work was to develop a membrane-based atmosphere comntrol (MBAC) subsystem that allows the controlled exchange of atmospheric componets (e.g., oxygen, carbon dioxide, and water vapor) between these chambers. The MBAC subsystem promises to offer a simple, nonenergy intensive method to separate, store and exchange atmospheric components, producing optimal concentrations of components in each chamber. In this paper, the results of a preliminary analysis of the MBAC subsystem for control of oxygen and nitrogen are presented. Additionally, the MBAC subsystem and its operation are described.

  16. 14 CFR 460.11 - Environmental control and life support systems.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... level of safety— (1) Composition of the atmosphere, which includes oxygen and carbon dioxide, and any... Crew § 460.11 Environmental control and life support systems. (a) An operator must provide atmospheric... or flight crew must monitor and control the following atmospheric conditions in the inhabited areas...

  17. 14 CFR 460.11 - Environmental control and life support systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... level of safety— (1) Composition of the atmosphere, which includes oxygen and carbon dioxide, and any... Crew § 460.11 Environmental control and life support systems. (a) An operator must provide atmospheric... or flight crew must monitor and control the following atmospheric conditions in the inhabited areas...

  18. 14 CFR 460.11 - Environmental control and life support systems.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... level of safety— (1) Composition of the atmosphere, which includes oxygen and carbon dioxide, and any... Crew § 460.11 Environmental control and life support systems. (a) An operator must provide atmospheric... or flight crew must monitor and control the following atmospheric conditions in the inhabited areas...

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

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  20. Verification of Wind Measurement with Mobile Laser Doppler System

    DOT National Transportation Integrated Search

    1977-09-01

    The Lockheed Mobile Atmospheric Unit is a laser Doppler velocimeter system designed for the remote measurement of the three components of atmospheric wind. The unit was tested at the National Oceanic and Atmospheric Administration Table Mountain Test...

  1. Status of the ISS Trace Contaminant Control System

    NASA Technical Reports Server (NTRS)

    Macatangay, Ariel V.; Perry, Jay L.; Johnson, Sharon A.; Belcher, Paul A.

    2009-01-01

    A habitable atmosphere is a fundamental requirement for human spaceflight. To meet such a requirement, the cabin atmosphere must be constantly scrubbed to maintain human life and system functionality. The primary system for atmospheric scrubbing of the US on-orbit segment (USOS) of the International Space Station (ISS) is the Trace Contaminant Control System (TCCS). As part of the Environmental Control and Life Support Systems (ECLSS) atmosphere revitalization rack in the US Lab, the TCCS operates continuously, scrubbing trace contaminants generated primarily by two sources: the metabolic offgassing of crew members and the offgassing of equipment in the ISS. It has been online for approximately 95% since activated in February 2001. The TCCS is comprised of a charcoal bed, a catalytic oxidizer, and a lithium hydroxide post-sorbent bed, all of which are designed to be replaced onorbit when necessary. In 2006, all three beds were replaced following an observed increase in the system resistance that occurred over a period several months. The beds were returned to ground and subjected to a test, teardown and evaluation to investigate the root cause(s) of the decrease in flow rate through the system. In addition, various chemical and physical analyses of the bed materials were performed to determine contaminant loading and any changes in performance. This paper will mainly focus on the results of these analyses and how this correlates with what has been observed from archival sampling and onorbit events. This may provide insight into the future performance of the TCCS and rate of change for orbital replacement units in the TCCS.

  2. An integration time adaptive control method for atmospheric composition detection of occultation

    NASA Astrophysics Data System (ADS)

    Ding, Lin; Hou, Shuai; Yu, Fei; Liu, Cheng; Li, Chao; Zhe, Lin

    2018-01-01

    When sun is used as the light source for atmospheric composition detection, it is necessary to image sun for accurate identification and stable tracking. In the course of 180 second of the occultation, the magnitude of sun light intensity through the atmosphere changes greatly. It is nearly 1100 times illumination change between the maximum atmospheric and the minimum atmospheric. And the process of light change is so severe that 2.9 times per second of light change can be reached. Therefore, it is difficult to control the integration time of sun image camera. In this paper, a novel adaptive integration time control method for occultation is presented. In this method, with the distribution of gray value in the image as the reference variable, and the concepts of speed integral PID control, the integration time adaptive control problem of high frequency imaging. The large dynamic range integration time automatic control in the occultation can be achieved.

  3. Optical technique for inner-scale measurement: possible astronomical applications.

    PubMed

    Masciadri, E; Vernin, J

    1997-02-20

    We propose an optical technique that allows us to estimate the inner scale by measuring the variance of angle of arrival fluctuations of collimated laser beams of different sections w (i) passing through a turbulent layer. To test the potential efficiency of the system, we made measurements on a turbulent air flow generated in the laboratory, the statistical properties of which are known and controlled, unlike atmospheric turbulence. We deduced a Kolmogorov behavior with a 6-mm inner scale and a 90-mm outer scale in accordance with measurements by a more complicated technique using the same turbulent channel. Our proposed method is especially sensitive to inner-scale measurement and can be adapted easily to atmospheric turbulence analysis. We propose an outdoor experimental setup that should work in less controlled conditions that can affect astronomical observations. The inner-scale assessment might be important when phase retrieval with Laplacian methods is used for adaptive optics purposes.

  4. A study of large scale gust generation in a small scale atmospheric wind tunnel with applications to Micro Aerial Vehicles

    NASA Astrophysics Data System (ADS)

    Roadman, Jason Markos

    Modern technology operating in the atmospheric boundary layer can always benefit from more accurate wind tunnel testing. While scaled atmospheric boundary layer tunnels have been well developed, tunnels replicating portions of the atmospheric boundary layer turbulence at full scale are a comparatively new concept. Testing at full-scale Reynolds numbers with full-scale turbulence in an "atmospheric wind tunnel" is sought. Many programs could utilize such a tool including Micro Aerial Vehicle(MAV) development, the wind energy industry, fuel efficient vehicle design, and the study of bird and insect flight, to name just a few. The small scale of MAVs provide the somewhat unique capability of full scale Reynolds number testing in a wind tunnel. However, that same small scale creates interactions under real world flight conditions, atmospheric gusts for example, that lead to a need for testing under more complex flows than the standard uniform flow found in most wind tunnels. It is for these reasons that MAVs are used as the initial testing application for the atmospheric gust tunnel. An analytical model for both discrete gusts and a continuous spectrum of gusts is examined. Then, methods for generating gusts in agreement with that model are investigated. Previously used methods are reviewed and a gust generation apparatus is designed. Expected turbulence and gust characteristics of this apparatus are compared with atmospheric data. The construction of an active "gust generator" for a new atmospheric tunnel is reviewed and the turbulence it generates is measured utilizing single and cross hot wires. Results from this grid are compared to atmospheric turbulence and it is shown that various gust strengths can be produced corresponding to weather ranging from calm to quite gusty. An initial test is performed in the atmospheric wind tunnel whereby the effects of various turbulence conditions on transition and separation on the upper surface of a MAV wing is investigated using the surface oil flow visualization technique.

  5. Bias Momentum Sizing for Hovering Dual-Spin Platforms

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Shin, Jong-Yeob; Moerder, Daniel D.

    2006-01-01

    An atmospheric flight vehicle in hover is typically controlled by varying its thrust vector. Achieving both levitation and attitude control with the propulsion system places considerable demands on it for agility and precision, particularly if the vehicle is statically unstable, or nearly so. These demands can be relaxed by introducing an appropriately sized angular momentum bias aligned with the vehicle's yaw axis, thus providing an additional margin of attitude stability about the roll and pitch axes. This paper describes a methodical approach for trading off angular momentum bias level needed with desired levels of vehicle response due to the design disturbance environment given a vehicle's physical parameters. It also describes several simplifications that provide a more physical and intuitive understanding of dual-spin dynamics for hovering atmospheric vehicles. This approach also mitigates the need for control torques and inadvertent actuator saturation difficulties in trying to stabilize a vehicle via control torques produced by unsteady aerodynamics, thrust vectoring, and unsteady throttling. Simulation results, based on a subscale laboratory test flying platform, demonstrate significant improvements in the attitude control robustness of the vehicle with respect to both wind disturbances and off-center of gravity payload changes during flight.

  6. Atmospheric heavy metals and Arsenic in China: Situation, sources and control policies

    NASA Astrophysics Data System (ADS)

    Duan, Jingchun; Tan, Jihua

    2013-08-01

    In recent years, heavy metal pollution accidents were reported frequently in China. The atmospheric heavy metal pollution is drawing all aspects of attention. This paper summarizes the recent research results from our studies and previous studies in recent years in China. The level, temporal variation, seasonal variation and size distribution of the heavy metals of atmospheric Lead(Pb), Vanadium(V), Manganese(Mn), Nickel(Ni), Chromium(Cr), Cadmium(Cd), Copper(Cu), Zinc(Zn) and Arsenic(As) were characterized in China. The emission characteristics and sources of atmospheric heavy metals and As in China were reviewed. Coal burning, iron and steel industry and vehicle emission are important sources in China. Control policies and effects in China were reviewed including emission standards, ambient air quality standards, phase out of leaded gasoline and so on, and further works for atmospheric heavy metals control were suggested. The comprehensive heavy metals pollution control measures and suggestions were put forward based on the summarization of the development and experience of the atmospheric heavy metal pollution control abroad.

  7. Methane Feedback on Atmospheric Chemistry: Methods, Models, and Mechanisms

    NASA Astrophysics Data System (ADS)

    Holmes, Christopher D.

    2018-04-01

    The atmospheric methane (CH4) chemical feedback is a key process for understanding the behavior of atmospheric CH4 and its environmental impact. This work reviews how the feedback is defined and used, then examines the meteorological, chemical, and emission factors that control the feedback strength. Geographical and temporal variations in the feedback are described and explained by HOx (HOx = OH + HO2) production and partitioning. Different CH4 boundary conditions used by models, however, make no meaningful difference to the feedback calculation. The strength of the CH4 feedback depends on atmospheric composition, particularly the atmospheric CH4 burden, and is therefore not constant. Sensitivity tests show that the feedback depends very weakly on temperature, insolation, water vapor, and emissions of NO. While the feedback strength has likely remained within 10% of its present value over the industrial era and likely will over the twenty-first century, neglecting these changes biases our understanding of CH4 impacts. Most environmental consequences per kg of CH4 emissions, including its global warming potential (GWP), scale with the perturbation time, which may have grown as much as 40% over the industrial era and continues to rise.

  8. KSC-97PC1032

    NASA Image and Video Library

    1997-07-10

    A payload canister in the Payload Changeout Room (PCR) at Launch Pad 39A holds the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2) payload for the STS-85 mission (center), as well as the Technology Applications and Science-1 (TAS-1) (top) and International Extreme Ultraviolet Hitchhiker-2 (IEH-2) (bottom) payloads. All three will be transferred from the PCR into the payload bay of the Space Shuttle Orbiter Discovery after the space vehicle arrives at the pad. The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth’s middle atmosphere. During the 11-day mission, the CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth’s atmosphere. The TAS-1 holds seven separate experiments that will provide data on the Earth’s topography and atmosphere, study the sun’s energy, and test new thermal control devices, as well as several student-developed experiments. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system

  9. KSC-97PC1008

    NASA Image and Video Library

    1997-07-07

    The Technology Applications and Science-1 (TAS-1) payload for the STS-85 mission rests in a payload canister in the Space Station Processing Facility prior to its trip out to Launch Pad 39A for installation into the payload bay of the Space Shuttle Orbiter Discovery. The TAS-1 holds seven separate experiments that will provide data on the Earth’s topography and atmosphere, study the sun’s energy, and test new thermal control devices, as well as several student-developed experiments. Other STS-85 payloads include the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2). The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth’s middle atmosphere. During the 11-day mission, the CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth’s atmosphere. The International Extreme Ultraviolet Hitchhiker-2 (IEH-2) will also be in the payload bay. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system

  10. KSC-97PC1033

    NASA Image and Video Library

    1997-07-10

    A payload canister in the Payload Changeout Room (PCR) at Launch Pad 39A holds the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2) payload for the STS-85 mission (center), as well as the Technology Applications and Science-1 (TAS-1) (top) and International Extreme Ultraviolet Hitchhiker-2 (IEH-2) (bottom) payloads. All three will be transferred from the PCR into the payload bay of the Space Shuttle Orbiter Discovery after the space vehicle arrives at the pad. The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth’s middle atmosphere. During the 11-day mission, the CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth’s atmosphere. The TAS-1 holds seven separate experiments that will provide data on the Earth’s topography and atmosphere, study the sun’s energy, and test new thermal control devices, as well as several student-developed experiments. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system

  11. 30 CFR 57.22228 - Preshift examination (I-A, I-C, II-A, III, and V-A mines).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the beginning of a shift following an idle shift, a competent person shall test the mine atmosphere... immediately follows another, a competent person shall test the mine atmosphere at each active working face for methane before work is started on that shift. (d) A competent person shall test the mine atmosphere at...

  12. 30 CFR 57.22228 - Preshift examination (I-A, I-C, II-A, III, and V-A mines).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the beginning of a shift following an idle shift, a competent person shall test the mine atmosphere... immediately follows another, a competent person shall test the mine atmosphere at each active working face for methane before work is started on that shift. (d) A competent person shall test the mine atmosphere at...

  13. 30 CFR 57.22228 - Preshift examination (I-A, I-C, II-A, III, and V-A mines).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the beginning of a shift following an idle shift, a competent person shall test the mine atmosphere... immediately follows another, a competent person shall test the mine atmosphere at each active working face for methane before work is started on that shift. (d) A competent person shall test the mine atmosphere at...

  14. Blended control, predictor-corrector guidance algorithm: an enabling technology for Mars aerocapture.

    PubMed

    Jits, Roman Y; Walberg, Gerald D

    2004-03-01

    A guidance scheme designed for coping with significant dispersion in the vehicle's state and atmospheric conditions is presented. In order to expand the flyable aerocapture envelope, control of the vehicle is realized through bank angle and angle-of-attack modulation. Thus, blended control of the vehicle is achieved, where the lateral and vertical motions of the vehicle are decoupled. The overall implementation approach is described, together with the guidance algorithm macrologic and structure. Results of guidance algorithm tests in the presence of various single and multiple off-nominal conditions are presented and discussed. c2003 Published by Elsevier Ltd.

  15. Impact of AIRS Thermodynamic Profiles on Precipitation Forecasts for Atmospheric River Cases Affecting the Western United States

    NASA Technical Reports Server (NTRS)

    Zavodsky, Bradley T.; Jedlovec, Gary J.; Blakenship, Clay B.; Wick, Gary A.; Neiman, Paul J.

    2013-01-01

    This project is a collaborative activity between the NASA Short-term Prediction Research and Transition (SPoRT) Center and the NOAA Hydrometeorology Testbed (HMT) to evaluate a SPoRT Advanced Infrared Sounding Radiometer (AIRS: Aumann et al. 2003) enhanced moisture analysis product. We test the impact of assimilating AIRS temperature and humidity profiles above clouds and in partly cloudy regions, using the three-dimensional variational Gridpoint Statistical Interpolation (GSI) data assimilation (DA) system (Developmental Testbed Center 2012) to produce a new analysis. Forecasts of the Weather Research and Forecasting (WRF) model initialized from the new analysis are compared to control forecasts without the additional AIRS data. We focus on some cases where atmospheric rivers caused heavy precipitation on the US West Coast. We verify the forecasts by comparison with dropsondes and the Cooperative Institute for Research in the Atmosphere (CIRA) Blended Total Precipitable Water product.

  16. Development of an Airborne Triple-Pulse 2-Micron Integrated Path Differential Absorption Lidar (IPDA) for Simultaneous Airborne Column Measurements of Carbon Dioxide and Water Vapor in the Atmosphere

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Yu, Jirong; Antill, Charles W.; Remus, Ruben

    2016-01-01

    This presentation will provide status and details of an airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar being developed at NASA Langley Research Center with support from NASA ESTO Instrument Incubator Program. The development of this active optical remote sensing IPDA instrument is targeted for measuring both atmospheric carbon dioxide and water vapor in the atmosphere from an airborne platform. This presentation will focus on the advancement of the 2-micron triple-pulse IPDA lidar development. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of seed laser locking, wavelength control, receiver and detector upgrades, laser packaging and lidar integration. Future plan for IPDA lidar system for ground integration, testing and flight validation will also be presented.

  17. 2009 Continued Testing of the Orion Atmosphere Revitalization Technology

    NASA Technical Reports Server (NTRS)

    Button, Amy B.; Swerterlitsch, Jeffrey J.

    2010-01-01

    An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Orion Atmosphere Revitalization System (ARS). In three previous years at this conference, reports were presented on extensive Johnson Space Center (JSC) testing of this technology in a sea-level pressure environment, with simulated and real human metabolic loads, in both open and closed-loop configurations. The test article design was iterated a third time before the latest series of such tests, which was performed in the first half of 2009. The new design incorporates a canister configuration modification for overall unit compactness and reduced pressure drop, as well as a new process flow control valve that incorporates both compressed gas purge and dual-end vacuum desorption capabilities. This newest test article is very similar to the flight article designs. Baseline tests of the new unit were performed to compare its performance to that of the previous test articles. Testing of compressed gas purge operations helped refine launchpad operating condition recommendations developed in earlier testing. Operating conditions used in flight program computer models were tested to validate the model projections. Specific operating conditions that were recommended by the JSC test team based on past test results were also tested for validation. The effects of vacuum regeneration line pressure on resulting cabin conditions was studied for high metabolic load periods, and a maximum pressure is recommended

  18. 2009 Continued Testing of the Orion Atmosphere Revitalization Technology

    NASA Technical Reports Server (NTRS)

    Button, Amy Lin; Sweterlitsch, Jeffrey

    2009-01-01

    An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Orion Atmosphere Revitalization System (ARS). In three previous years at this conference, reports were presented on extensive Johnson Space Center (JSC) testing of this technology in a sea-level pressure environment with simulated and real human metabolic loads in both open and closed-loop configurations. The test article design was iterated a third time before the latest series of such tests, which was performed in the first half of 2009. The new design incorporates a canister configuration modification for overall unit compactness and reduced pressure drop, as well as a new process flow control valve that incorporates both compressed gas purge and dual-end vacuum desorption capabilities. This newest test article is very similar to the flight article designs. Baseline tests of the new unit were performed to compare its performance to that of the previous test articles. Testing of compressed gas purge operations helped refine launchpad operating condition recommendations developed in earlier testing. Operating conditions used in flight program computer models were tested to validate the model projections. Specific operating conditions that were recommended by the JSC test team based on past test results were also tested for validation. The effects of vacuum regeneration line pressure on resulting cabin conditions was studied for high metabolic load periods, and a maximum pressure is recommended.

  19. Design validation of an eye-safe scanning aerosol lidar with the Center for Lidar and Atmospheric Sciences Students (CLASS) at Hampton University

    NASA Astrophysics Data System (ADS)

    Richter, Dale A.; Higdon, N. S.; Ponsardin, Patrick L.; Sanchez, David; Chyba, Thomas H.; Temple, Doyle A.; Gong, Wei; Battle, Russell; Edmondson, Mika; Futrell, Anne; Harper, David; Haughton, Lincoln; Johnson, Demetra; Lewis, Kyle; Payne-Baggott, Renee S.

    2002-01-01

    ITTs Advanced Engineering and Sciences Division and the Hampton University Center for Lidar and Atmospheric Sciences Students (CLASS) team have worked closely to design, fabricate and test an eye-safe, scanning aerosol-lidar system that can be safely deployed and used by students form a variety of disciplines. CLASS is a 5-year undergraduate- research training program funded by NASA to provide hands-on atmospheric-science and lidar-technology education. The system is based on a 1.5 micron, 125 mJ, 20 Hz eye-safe optical parametric oscillator (OPO) and will be used by the HU researchers and students to evaluate the biological impact of aerosols, clouds, and pollution a variety of systems issues. The system design tasks we addressed include the development of software to calculate eye-safety levels and to model lidar performance, implementation of eye-safety features in the lidar transmitter, optimization of the receiver using optical ray tracing software, evaluation of detectors and amplifiers in the near RI, test of OPO and receiver technology, development of hardware and software for laser and scanner control and video display of the scan region.

  20. Schinus terebinthifolius Raddi (Anacardiaceae) in the healing process of gastrorraphy in rats.

    PubMed

    dos Santos, Orlando José; Barros-Filho, Allan Kardec Duailibe; Malafaia, Osvaldo; Ribas-Filho, Jurandir Marcondes; Santos, Rayan Haquim Pinheiro; Santos, Rennan Abud Pinheiro

    2012-01-01

    Gastrorraphy, isolated or associated with the use of biological adhesives, was throughout the history of surgery the usual way to promote healing in gastric lesions and the use of herbal medicine has been increasingly more employed. To evaluate the wound healing in the stomach of rats with the use of the hydroalcoholic extract of Schinus terebinthifolius Raddi (aroeira). Sixty rats, adult males, were divided into two groups: aroeira group and control group. Each one was subdivided into four subgroups of 15 animals (test groups). Each subdivided subgroup was also subdivided into three subgroups of five rats (deaths periods of 7, 14 and 21 days). All animals underwent the same surgical procedure (injury and stomach suture); animals in the aroeira group received daily dose of 100 mg/kg of hydroalcoholic extract via gavage while the control group received isotonic saline solution. Parameters evaluated were: macroscopic and microscopic changes, test for resistance to insufflation of atmospheric air and test for tensile strength. All animals had good healing of the abdominal wall and gastrorraphies without infection and dehiscence. Both groups had adhesions to the gastrorraphies surfaces with neighboring organs. The resistance test by insufflation of atmospheric air and tensile strength showed higher average of pressure on the 7th day and breaking strength in the time periods for the aroeira group. The intensity of chronic inflammation revealed statistically significant differences in the variables fibroblast proliferation and collagen. The use of hydroalcoholic extract of Schinus terebinthifolius Raddi accelerated the stomach healing in rats.

  1. Hemocompatible control of sulfobetaine-grafted polypropylene fibrous membranes in human whole blood via plasma-induced surface zwitterionization.

    PubMed

    Chen, Sheng-Han; Chang, Yung; Lee, Kueir-Rarn; Wei, Ta-Chin; Higuchi, Akon; Ho, Feng-Ming; Tsou, Chia-Chun; Ho, Hsin-Tsung; Lai, Juin-Yih

    2012-12-21

    In this work, the hemocompatibility of zwitterionic polypropylene (PP) fibrous membranes with varying grafting coverage of poly(sulfobetaine methacrylate) (PSBMA) via plasma-induced surface polymerization was studied. Charge neutrality of PSBMA-grafted layers on PP membrane surfaces was controlled by the low-pressure and atmospheric plasma treatment in this study. The effects of grafting composition, surface hydrophilicity, and hydration capability on blood compatibility of the membranes were determined. Protein adsorption onto the different PSBMA-grafted PP membranes from human fibrinogen solutions was measured by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. Blood platelet adhesion and plasma clotting time measurements from a recalcified platelet-rich plasma solution were used to determine if platelet activation depends on the charge bias of the grafted PSBMA layer. The charge bias of PSBMA layer deviated from the electrical balance of positively and negatively charged moieties can be well-controlled via atmospheric plasma-induced interfacial zwitterionization and was further tested with human whole blood. The optimized PSBMA surface graft layer in overall charge neutrality has a high hydration capability and keeps its original blood-inert property of antifouling, anticoagulant, and antithrmbogenic activities when it comes into contact with human blood. This work suggests that the hemocompatible nature of grafted PSBMA polymers by controlling grafting quality via atmospheric plasma treatment gives a great potential in the surface zwitterionization of hydrophobic membranes for use in human whole blood.

  2. Test plan 241-C-103 natural breathing characteristics evaluation using the ultra sensitive flowmeter

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

    Hertelendy, N.A.

    1995-02-13

    To facilitate the reduction of worker exposure to hazardous fumes and vapors, it is imperative to characterize and measure flows out of waste tanks that breathe due to atmospheric pressure changes. These measurements will lead to a better understanding of how these tanks breathe and thus will aid in better worker exposure control at lower cost.

  3. Energy extraction from atmospheric turbulence to improve flight vehicle performance

    NASA Astrophysics Data System (ADS)

    Patel, Chinmay Karsandas

    Small 'bird-sized' Unmanned Aerial Vehicles (UAVs) have now become practical due to technological advances in embedded electronics, miniature sensors and actuators, and propulsion systems. Birds are known to take advantage of wind currents to conserve energy and fly long distances without flapping their wings. This dissertation explores the possibility of improving the performance of small UAVs by extracting the energy available in atmospheric turbulence. An aircraft can gain energy from vertical gusts by increasing its lift in regions of updraft and reducing its lift in downdrafts - a concept that has been known for decades. Starting with a simple model of a glider flying through a sinusoidal gust, a parametric optimization approach is used to compute the minimum gust amplitude and optimal control input required for the glider to sustain flight without losing energy. For small UAVs using optimal control inputs, sinusoidal gusts with amplitude of 10--15% of the cruise speed are sufficient to keep the aircraft aloft. The method is then modified and extended to include random gusts that are representative of natural turbulence. A procedure to design optimal control laws for energy extraction from realistic gust profiles is developed using a Genetic Algorithm (GA). A feedback control law is designed to perform well over a variety of random gusts, and not be tailored for one particular gust. A small UAV flying in vertical turbulence is shown to obtain average energy savings of 35--40% with the use of a simple control law. The design procedure is also extended to determine optimal control laws for sinusoidal as well as turbulent lateral gusts. The theoretical work is complemented by experimental validation using a small autonomous UAV. The development of a lightweight autopilot and UAV platform is presented. Flight test results show that active control of the lift of an autonomous glider resulted in approximately 46% average energy savings compared to glides with fixed control surfaces. Statistical analysis of test samples shows that 19% of the active control test runs resulted in no energy loss, thus demonstrating the potential of the 'gust soaring' concept to dramatically improve the performance of small UAVs.

  4. Radial growth rate increases in naturally occurring ponderosa pine trees: a late-20th century CO2 fertilization effect?

    PubMed

    Soulé, Peter T; Knapp, Paul A

    2006-01-01

    The primary objective of this study was to determine if gradually increasing levels of atmospheric CO2, as opposed to 'step' increases commonly employed in controlled studies, have a positive impact on radial growth rates of ponderosa pine (Pinus ponderosa) in natural environments, and to determine the spatial extent and variability of this growth enhancement. We developed a series of tree-ring chronologies from minimally disturbed sites across a spectrum of environmental conditions. A series of difference of means tests were used to compare radial growth post-1950, when the impacts of rising atmospheric CO2 are best expressed, with that pre-1950. Spearman's correlation was used to relate site stress to growth-rate changes. Significant increases in radial growth rates occurred post-1950, especially during drought years, with the greatest increases generally found at the most water-limited sites. Site harshness is positively related to enhanced radial growth rates. Atmospheric CO2 fertilization is probably operative, having a positive effect on radial growth rates of ponderosa pine through increasing water-use efficiency. A CO2-driven growth enhancement may affect ponderosa pine growing under both natural and controlled conditions.

  5. Comparative pick-up ion distributions at Mars and Venus: Consequences for atmospheric deposition and escape

    NASA Astrophysics Data System (ADS)

    Curry, Shannon M.; Luhmann, Janet; Ma, Yingjuan; Liemohn, Michael; Dong, Chuanfei; Hara, Takuya

    2015-09-01

    Without the shielding of a substantial intrinsic dipole magnetic field, the atmospheres of Mars and Venus are particularly susceptible to similar atmospheric ion energization and scavenging processes. However, each planet has different attributes and external conditions controlling its high altitude planetary ion spatial and energy distributions. This paper describes analogous test particle simulations in background MHD fields that allow us to compare the properties and fates, precipitation or escape, of the mainly O+ atmospheric pick-up ions at Mars and Venus. The goal is to illustrate how atmospheric and planetary scales affect the upper atmospheres and space environments of our terrestrial planet neighbors. The results show the expected convection electric field-related hemispheric asymmetries in both precipitation and escape, where the degree of asymmetry at each planet is determined by the planetary scale and local interplanetary field strength. At Venus, the kinetic treatment of O+ reveals a strong nightside source of precipitation while Mars' crustal fields complicate the simple asymmetry in ion precipitation and drive a dayside source of precipitation. The pickup O+ escape pattern at both Venus and Mars exhibits low energy tailward escape, but Mars exhibits a prominent, high energy 'polar plume' feature in the hemisphere of the upward convection electric field while the Venus ion wake shows only a modest poleward concentration. The overall escape is larger at Venus than Mars (2.1 ×1025 and 4.3 ×1024 at solar maximum, respectively), but the efficiency (likelihood) of O+ escaping is 2-3 times higher at Mars. The consequences of these comparisons for pickup ion related atmospheric energy deposition, loss rates, and detection on spacecraft including PVO, VEX, MEX and MAVEN are considered. In particular, both O+ precipitation and escape show electric field controlled asymmetries that grow with energy, while the O+ fluxes and energy spectra at selected spatial locations show characteristic signatures of the pickup related acceleration and precipitation.

  6. Heating of food in modified atmospheres

    NASA Technical Reports Server (NTRS)

    Sweat, V. E.

    1973-01-01

    Food heating tests were conducted with two model foods; a Carnation turkey salad sandwich spread and frankfurter chunks in a sauce of water and agar. For the first series of tests comparing heating in five different atmospheres, the atmospheres were: (1) air at atmospheric pressure, (2) air at 5 psia, (3) helium at 5 psia, (4) oxygen-nitrogen mixture at 5 psia, and (5) oxygen-helium mixture at 5 psia. No significant differences in heating rates were caused by varying the atmosphere. Initial food temperatures were varied in the next series of tests. Heating times were found to increase with decreasing initial temperatures. There were also differences in heating times between the two foods used.

  7. 49 CFR 195.583 - What must I do to monitor atmospheric corrosion control?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false What must I do to monitor atmospheric corrosion... SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Corrosion Control § 195.583 What must I do to monitor atmospheric corrosion control? (a) You must inspect each pipeline or portion of pipeline that is...

  8. Trajectory Software With Upper Atmosphere Model

    NASA Technical Reports Server (NTRS)

    Barrett, Charles

    2012-01-01

    The Trajectory Software Applications 6.0 for the Dec Alpha platform has an implementation of the Jacchia-Lineberry Upper Atmosphere Density Model used in the Mission Control Center for International Space Station support. Previous trajectory software required an upper atmosphere to support atmosphere drag calculations in the Mission Control Center. The Functional operation will differ depending on the end-use of the module. In general, the calling routine will use function-calling arguments to specify input to the processor. The atmosphere model will then compute and return atmospheric density at the time of interest.

  9. Sonic Booms in Atmospheric Turbulence (SonicBAT) Testing

    NASA Image and Video Library

    2017-08-22

    An engineer in a control trailer at NASA's Kennedy Space Center in Florida monitors data before flights of agency F-18 jets to measure the effects of sonic booms. Several flights a day have been taking place the week of Aug. 21, 2017 as part of NASA's Sonic Booms in Atmospheric Turbulence, or SonicBAT II Program. NASA at Kennedy is partnering with the agency's Armstrong Flight Research Center in California, Langley Research Center in Virginia, and Space Florida for a program in which F-18 jets will take off from the Shuttle Landing Facility and fly at supersonic speeds while agency researchers measure the effects of low-altitude turbulence caused by sonic booms.

  10. KENNEDY SPACE CENTER, FLA. - Louis MacDowell (right), Testbed manager, explains to Center Director Jim Kennedy the use of astmospheric calibration specimens. Placed at various locations, they can rank the corrosivity of the given environment. The KSC Beach Corrosion Test Site was established in the 1960s and has provided more than 30 years of historical information on the long-term performance of many materials in use at KSC and other locations around the world. Located 100 feet from the Atlantic Ocean approximately 1 mile south of the Space Shuttle launch sites, the test facility includes an atmospheric exposure site, a flowing seawater exposure site, and an on-site electrochemistry laboratory and monitoring station. The beach laboratory is used to conduct real-time corrosion experiments and provides for the remote monitoring of surrounding weather conditions. The newly added flowing seawater immersion facility provides for the immersion testing of materials and devices under controlled conditions.

    NASA Image and Video Library

    2003-08-21

    KENNEDY SPACE CENTER, FLA. - Louis MacDowell (right), Testbed manager, explains to Center Director Jim Kennedy the use of astmospheric calibration specimens. Placed at various locations, they can rank the corrosivity of the given environment. The KSC Beach Corrosion Test Site was established in the 1960s and has provided more than 30 years of historical information on the long-term performance of many materials in use at KSC and other locations around the world. Located 100 feet from the Atlantic Ocean approximately 1 mile south of the Space Shuttle launch sites, the test facility includes an atmospheric exposure site, a flowing seawater exposure site, and an on-site electrochemistry laboratory and monitoring station. The beach laboratory is used to conduct real-time corrosion experiments and provides for the remote monitoring of surrounding weather conditions. The newly added flowing seawater immersion facility provides for the immersion testing of materials and devices under controlled conditions.

  11. Ethanol reduces ripening of 'Royal Gala' apples stored in controlled atmosphere.

    PubMed

    Weber, Anderson; Brackmann, Auri; Both, Vanderlei; Pavanello, Elizandra P; Anese, Rogerio O; Schorr, Márcio R W

    2016-03-01

    This work aims at evaluate ethanol effect of acetaldehyde application in post-storage quality of 'Royal Gala' apples maintenance, and to compare them with consolidated storage techniques. Thus two experiments were performed during the years of 2008 and 2009. In the first experiment (2008), the application of ethanol, acetaldehyde or 1-MCP and ethylene scrubbing were tested. Fruits were stored in controlled atmosphere (CA) with 1.0kPa O2 and 2.0kPa CO2 at 0.5°C. In the second experiment (2009), the treatments tested were ethanol application combined or not with low relative humidity (LRH) and LRH alone. In this experiment, apples were stored in CA with 1.2kPa O2 + 2.5kPa CO2 at 0.5°C. After eight months of storage, 0.5 mL ethanol kg-1 apples month-1 or 0.25 mL acetaldehyde kg-1 apples month-1 increased mealiness, flesh browning, and decays incidence and reduced flesh firmness. In contrast, 0.3 mL ethanol kg-1 apples month-1, tested on second experiment, prevented fruit softening and decreased ACC oxidase activity and ethylene production. Although lower relative humidity was not efficient in maintaining post-storage quality, it enhanced the positive effect of ethanol application at 0.3 mL kg-1 apples month-1.

  12. Preliminary control law and hardware designs for a ride quality augmentation system for commuter aircraft. Phase 2

    NASA Technical Reports Server (NTRS)

    Davis, D. J.; Linse, D. J.; Suikat, R.; Entz, D. P.

    1986-01-01

    The continued investigation of the design of Ride Quality Augmentation Systems (RQAS) for commuter aircraft is described. The purpose of these RQAS is the reduction of the vertical and lateral acceleration response of the aircraft due to atmospheric turbulence by the application of active control. The current investigations include the refinement of the sample data feedback control laws based on the control-rate-weighting and output-weighting optimal control design techniqes. These control designs were evaluated using aircraft time simulations driven by Dryden spectra turbulence. Fixed gain controllers were tested throughout the aircrft operating envelope. The preliminary design of the hardware modifications necessary to implement and test the RQAS on a commuter aircraft is included. These include a separate surface elevator and the flap modifications to provide both direct lift and roll control. A preliminary failure mode investigation was made for the proposed configuration. The results indicate that vertical acceleration reductions of 45% and lateral reductions of more than 50% are possible. A fixed gain controller appears to be feasible with only minor response degradation.

  13. Closed-Loop Acoustic Control of Reverberant Room for Satellite Environmental Testing

    NASA Astrophysics Data System (ADS)

    Janssens, Karl; Bianciardi, Fabio; Sabbatini, Danilo; Debille, Jan; Carrella, Alex

    2012-07-01

    The full satellite acoustic test is an important milestone in a satellite launch survivability verification campaign. This test is required to verify the satellite’s mechanical design against the high-level acoustic loads induced by the launch vehicle during the atmospheric flight. During the test, the satellite is subjected to a broadband diffuse acoustic field, reproducing the pressure levels observed during launch. The excitation is in most cases provided by a combination of horns for the low frequencies and noise generators for the higher frequencies. Acoustic control tests are commonly performed in reverberant rooms, controlling the sound pressure levels in third octave bands over the specified target spectrum. This paper discusses an automatic feedback control system for acoustic control of large reverberation rooms for satellite environmental testing. The acoustic control system consists of parallel third octave PI (Proportional Integral) feedback controllers that take the reverberation characteristics of the room into consideration. The drive output of the control system is shaped at every control step based on the comparison of the average third octave noise spectrum, measured from a number of microphones in the test room, with the target spectrum. Cross-over filters split the output drive into band- limited signals to feed each of the horns. The control system is realized in several steps. In the first phase, a dynamic process model is developed, including the non-linear characteristics of the horns and the reverberant properties of the room. The model is identified from dynamic experiments using system identification techniques. In the next phase, an adequate control strategy is designed which is capable of reaching the target spectrum in the required time period without overshoots. This control strategy is obtained from model-in-the-loop (MIL) simulations, evaluating the performance of various potential strategies. Finally, the proposed strategy is implemented in real-time and its control performance tested and validated.

  14. Fourier transform wavefront control with adaptive prediction of the atmosphere.

    PubMed

    Poyneer, Lisa A; Macintosh, Bruce A; Véran, Jean-Pierre

    2007-09-01

    Predictive Fourier control is a temporal power spectral density-based adaptive method for adaptive optics that predicts the atmosphere under the assumption of frozen flow. The predictive controller is based on Kalman filtering and a Fourier decomposition of atmospheric turbulence using the Fourier transform reconstructor. It provides a stable way to compensate for arbitrary numbers of atmospheric layers. For each Fourier mode, efficient and accurate algorithms estimate the necessary atmospheric parameters from closed-loop telemetry and determine the predictive filter, adjusting as conditions change. This prediction improves atmospheric rejection, leading to significant improvements in system performance. For a 48x48 actuator system operating at 2 kHz, five-layer prediction for all modes is achievable in under 2x10(9) floating-point operations/s.

  15. Method and apparatus for container leakage testing

    DOEpatents

    Kronberg, James W.

    1995-01-01

    An apparatus for use in one-hundred percent leak testing of food containers used in conjunction with a tracer gas. The apparatus includes a shell with entrance and exit air locks to create a controlled atmosphere through which a series of containers is conveyed by a conveyor belt. The pressure in the shell is kept lower than the pressure in the containers and the atmosphere is made to flow with the containers so that a tracer gas placed in the packages before sealing them will leak more readily, but the leaked tracer gas will remain associated with the leaking package as it moves through the shell. The leaks are detected with a sniffer probe in fluid communication with a gas chromatograph. The gas chromatograph issues a signal when it detects a leak to an ejector that will eject the leaking container from the conveyor. The system is timed so that the series of containers can move continuously into and out of the shell, past the probe and the ejector, without stopping, yet each package is tested for leaks and removed if leaking.

  16. The USML-1 wire insulation flammability glovebox experiment

    NASA Technical Reports Server (NTRS)

    Greenberg, Paul S.; Sacksteder, Kurt R.; Kashiwagi, Takashi

    1995-01-01

    Flame spreading tests have been conducted using thin fuels in microgravity where buoyant convection is suppressed. In spacecraft experiments flames were ignited in quiescent atmospheres with an elevated oxygen content, demonstrating that diffusional mechanisms can be sufficient alone to sustain flame spreading. In ground-based facilities (i.e. drop towers and parabolic aircraft) low-speed convection sustains flames at much lower concentrations of atmospheric oxygen than in quiescent microgravity. Ground-based experiments are limited to very thin fuels (e.g., tissue paper); practical fuels, which are thicker, require more test time than is available. The Glovebox Facility provided for the USML 1 mission provided an opportunity to obtain flame spreading data for thicker fuel Herein we report the results from the Wire Insulation Flammability (WIF) Experiment performed in the Glovebox Facility. This experiment explored the heating, ignition and burning of 0.65 mm thick polyethylene wire insulation in low-speed flows in a reduced gravity environment. Four tests were conducted, two each in concurrent flow (WIF A and C) and opposed flow (WIF B and D), providing the first demonstration of flame spreading in controlled forced convection conducted in space.

  17. Global ice-sheet system interlocked by sea level

    NASA Astrophysics Data System (ADS)

    Denton, George H.; Hughes, Terence J.; Karlén, Wibjörn

    1986-07-01

    Denton and Hughes (1983, Quaternary Research20, 125-144) postulated that sea level linked a global ice-sheet system with both terrestrial and grounded marine components during late Quaternary ice ages. Summer temperature changes near Northern Hemisphere melting margins initiated sea-level fluctuations that controlled marine components in both polar hemispheres. It was further proposed that variations of this ice-sheet system amplified and transmitted Milankovitch summer half-year insolation changes between 45 and 75°N into global climatic changes. New tests of this hypothesis implicate sea level as a major control of the areal extent of grounded portions of the Antarctic Ice Sheet, thus fitting the concept of a globally interlocked ice-sheet system. But recent atmospheric modeling results ( Manabe and Broccoli, 1985, Journal of Geophysical Research90, 2167-2190) suggest that factors other than areal changes of the grounded Antarctic Ice Sheet strongly influenced Southern Hemisphere climate and terminated the last ice age simultaneously in both polar hemispheres. Atmospheric carbon dioxide linked to high-latitude oceans is the most likely candidate ( Shackleton and Pisias, 1985, Atmospheric carbon dioxide, orbital forcing, and climate. In "The Carbon Cycle and Atmospheric CO 2: Natural Variations Archean to Present" (E. T. Sundquest and W. S. Broecker, Eds.), pp. 303-318. Geophysical Monograph 32, American Geophysical Union, Washington, D.C.), but another potential influence was high-frequency climatic oscillations (2500 yr). It is postulated that variations in atmospheric carbon dioxide acted through an Antarctic ice shelf linked to the grounded ice sheet to produce and terminate Southern Hemisphere ice-age climate. It is further postulated that Milankovitch summer insolation combined with a warm high-frequency oscillation caused marked recession of Northern Hemisphere ice-sheet melting margins and the North Atlantic polar front about 14,000 14C yr B.P. This permitted renewed formation of North Atlantic Deep Water, which could well have controlled atmospheric carbon dioxide ( W. S. Broecker, D. M. Peteet, and D. Rind, 1985, Nature ( London) 315, 21-26). Combined melting and consequent sea-level rise from the three warming factors initiated irreversible collapse of the interlocked global ice-sheet system, which was at its largest but most vulnerable configuration.

  18. Regenerative Life Support Systems (RLSS) test bed performance - Characterization of plant performance in a controlled atmosphere

    NASA Technical Reports Server (NTRS)

    Edeen, Marybeth; Henninger, Donald

    1991-01-01

    By growing higher plants for food, lunar and Martian manned habitats will not only reduce resupply requirements but obtain CO2 removal and both oxygen-production and water-reclamation requirements. Plants have been grown in the RLSS at NASA-Johnson in order to quantitatively evaluate plant CO2 accumulation, O2 generation, evapotranspiration, trace-contaminant generation, and biomass productivity. Attention is presently given to test conditions and anomalies in these RLSS trials; areas where performance must be improved have been identified.

  19. Experimental Investigation of Gas/Slag/Matte/Tridymite Equilibria in the Cu-Fe-O-S-Si System in Controlled Atmospheres: Development of Technique

    NASA Astrophysics Data System (ADS)

    Fallah-Mehrjardi, Ata; Hidayat, Taufiq; Hayes, Peter C.; Jak, Evgueni

    2017-12-01

    The majority of primary pyrometallurgical copper making processes involve the formation of two immiscible liquid phases, i.e., matte product and the slag phase. There are significant gaps and discrepancies in the phase equilibria data of the slag and the matte systems due to issues and difficulties in performing the experiments and phase analysis. The present study aims to develop an improved experimental methodology for accurate characterisation of gas/slag/matte/tridymite equilibria in the Cu-Fe-O-S-Si system under controlled atmospheres. The experiments involve high-temperature equilibration of synthetic mixtures on silica substrates in CO/CO2/SO2/Ar atmospheres, rapid quenching of samples into water, and direct composition measurement of the equilibrium phases using Electron Probe X-ray Microanalysis (EPMA). A four-point-test procedure was applied to ensure the achievement of equilibrium, which included the following: (i) investigation of equilibration as a function of time, (ii) assessment of phase homogeneity, (iii) confirmation of equilibrium by approaching from different starting conditions, and (iv) systematic analysis of the reactions specific to the system. An iterative improved experimental methodology was developed using this four-point-test approach to characterize the complex multi-component, multi-phase equilibria with high accuracy and precision. The present study is a part of a broader overall research program on the characterisation of the multi-component (Cu-Fe-O-S-Si-Al-Ca-Mg), multi-phase (gas/slag/matte/metal/solids) systems with minor elements (Pb, Zn, As, Bi, Sn, Sb, Ag, and Au).

  20. Cytogenetic biomonitoring carried out in a village (Dolon) adjacent to the Semipalatinsk nuclear weapon test site.

    PubMed

    Testa, A; Stronati, L; Ranaldi, R; Spanò, M; Steinhäusler, F; Gastberger, M; Hubmer, A; Ptitskaya, L; Akhmetov, M

    2001-06-01

    The Semipalatinsk region (Kazakhstan Republic) has been affected by extensive radioactive contamination due to more than 450 nuclear tests of which almost 100 were exploded in the atmosphere. The present results refer to cytogenetic assessments in a study cohort of the population of Dolon, a settlement located on the NE boundary of the nuclear weapon test site, which was exposed to elevated doses of ionising radiation primarily due to the first Soviet nuclear test in 1949. Conventional cytogenetic analyses were carried out on 21 blood samples from individuals (more than 50 years old) living in Dolon since the very beginning of nuclear testing. A matched control group included 20 individuals living in non-contaminated areas. Higher frequencies of chromosome aberrations were found in the Dolon cohort compared to the control group, even though they remain within the range of the background levels reported for large normal human population studies on elderly individuals.

  1. The development and testing of a regenerable CO2 and humidity control system for Shuttle

    NASA Technical Reports Server (NTRS)

    Boehm, A. M.

    1977-01-01

    A regenerable CO2 and humidity control system is presently being developed for potential use on Shuttle as an alternate to the baseline lithium hydroxide (LiOH) system. The system utilizes a sorbent material (designated 'HS-C') to adsorb CO2 and water vapor from the cabin atmosphere and desorb the CO2 and water vapor overboard when exposed to a space vacuum. Continuous operation is achieved by utilizing two beds which are alternately cycled between adsorption and desorption. This paper presents the significant hardware development and test accomplishments of the past year. A half-size breadboard system utilizing a flight configuration canister was successfully performance tested in simulated Shuttle missions. A vacuum desorption test provided considerable insight into the desorption phenomena and allowed a significant reduction of the Shuttle vacuum duct size. The fabrication and testing of a flight prototype canister and flight prototype vacuum valves have proven the feasibility of these full-size, flight-weight components.

  2. [Regional atmospheric environment risk source identification and assessment].

    PubMed

    Zhang, Xiao-Chun; Chen, Wei-Ping; Ma, Chun; Zhan, Shui-Fen; Jiao, Wen-Tao

    2012-12-01

    Identification and assessment for atmospheric environment risk source plays an important role in regional atmospheric risk assessment and regional atmospheric pollution prevention and control. The likelihood exposure and consequence assessment method (LEC method) and the Delphi method were employed to build a fast and effective method for identification and assessment of regional atmospheric environment risk sources. This method was applied to the case study of a large coal transportation port in North China. The assessment results showed that the risk characteristics and the harm degree of regional atmospheric environment risk source were in line with the actual situation. Fast and effective identification and assessment of risk source has laid an important foundation for the regional atmospheric environmental risk assessment and regional atmospheric pollution prevention and control.

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

    NASA Technical Reports Server (NTRS)

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

    2012-01-01

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

  4. LBA-ECO TG-07 Soil Trace Gas Flux and Root Mortality, Tapajos National Forest

    Treesearch

    R.K. Varner; M.M. Keller

    2009-01-01

    This data set reports the results of an experiment that tested the short-term effects of root mortality on the soil-atmosphere fluxes of nitrous oxide, nitric oxide, methane, and carbon dioxide in a tropical evergreen forest. Weekly trace gas fluxes are provided for treatment and control plots on sand and clay tropical forest soils in two comma separated ASCII files....

  5. Efficacy of Controlled Atmosphere Treatments to Manage Arthropod Pests of Dry-Cured Hams

    PubMed Central

    Hasan, Md. Mahbub; Aikins, Michael J.; Schilling, Wes; Phillips, Thomas W.

    2016-01-01

    Research here explored the use of controlled atmospheres (CA) for managing arthropod pests that infest dry-cured hams. Experiments were conducted with low oxygen (O2) achieved with low pressure under a vacuum, high carbon dioxide (CO2), and ozone (O3). Results showed that both low O2 and high CO2 levels required exposures up to 144 h to kill 100% of all stages of red-legged ham beetle, Necrobia rufipes (De Geer) (Coleoptera: Cleridae) and ham mite Tyrophagus putrescentiae (Schrank) (Sarcoptiformes: Acaridae) at 23 °C. In addition, both low O2 and high CO2 had no significant mortality against the ham beetle and ham mites at short exposures ranging from 12 to 48 h. Ham beetles were more tolerant than ham mites to an atmosphere of 75.1% CO2 and low pressure of 25 mm Hg, which imposed an atmosphere estimated at 0.9% O2. Both low O2 and high CO2 trials indicated that the egg stages of both species were more tolerant than other stages tested, but N. rufipes eggs and pupae were more susceptible than larvae and adults to high concentration ozone treatments. The results indicate that O3 has potential to control ham beetles and ham mites, particularly at ≈166 ppm in just a 24 h exposure period, but O3 is known from other work to have poor penetration ability, thus it may be more difficult to apply effectively than low O2 or high CO2. would be. CA treatment for arthropod pests of dry-cured hams show promise as components of integrated pest management programs after methyl bromide is no longer available for use. PMID:27598209

  6. APOD Mission Status and Observations by VLBI

    NASA Astrophysics Data System (ADS)

    Tang, Geshi; Sun, Jing; Li, Xie; Liu, Shushi; Chen, Guangming; Ren, Tianpeng; Wang, Guangli

    2016-12-01

    On September 20, 2015, 20 satellites were successfully launched from the TaiYuan Satellite Launch Center by a Chinese CZ-6 test rocket and are, since then, operated in a circular, near-polar orbit at an altitude of 520 km. Among these satellites, a set of four CubSats, named APOD (Atmospheric density detection and Precise Orbit Determination), are intended for atmospheric density in-situ detection and derivation via precise orbit. The APOD satellites, manufactured by DFH Co., carry a number of instruments including a density detector, a dual-frequency GNSS (GPS/BD) receiver, an SLR reflector, and a VLBI S/X beacon. The APOD mission aims at detecting the atmospheric density below 520 km. The ground segment is controlled by BACC (Beijing Aerospace Control Center) including payload operation as well as science data receiving, processing, archiving, and distribution. Currently, the in-orbit test of the nano-satellites and their payloads are completed, and preliminary results show that the precision of the orbit determination is about 10 cm derived from both an overlap comparison and an SLR observation validation. The in-situ detected density calibrated by orbit-derived density demonstrates that the accuracy of atmospheric mass density is approximately 4.191×10^{-14} kgm^{-3}, about 5.5% of the measurement value. Since three space-geodetic techniques (i.e., GNSS, SLR, and VLBI) are co-located on the APOD nano-satellites, the observations can be used for combination and validation in order to detect systematic differences. Furthermore, the observations of the APOD satellites by VLBI radio telescopes can be used in an ideal fashion to link the dynamical reference frames of the satellite with the terrestrial and, most importantly, with the celestial reference frame as defined by the positions of quasars. The possibility of observing the APOD satellites by IVS VLBI radio telescopes will be analyzed, considering continental-size VLBI observing networks and the small telescopes with sufficient speed.

  7. Crustal tracers in the atmosphere and ocean: Relating their concentrations, fluxes, and ages

    NASA Astrophysics Data System (ADS)

    Han, Qin

    Crustal tracers are important sources of key limiting nutrients (e.g., iron) in remote ocean regions where they have a large impact on global biogeochemical cycles. However, the atmospheric delivery of bio-available iron to oceans via mineral dust aerosol deposition is poorly constrained. This dissertation aims to improve understanding and model representation of oceanic dust deposition and to provide soluble iron flux maps by testing observations of crustal tracer concentrations and solubilities against predictions from two conceptual solubility models. First, we assemble a database of ocean surface dissolved Al and incorporate Al cycling into the global Biogeochemical Elemental Cycling (BEC) model. The observed Al concentrations show clear basin-scale differences that are useful for constraining dust deposition. The dynamic mixed layer depth and Al residence time in the BEC model significantly improve the simulated dissolved Al field. Some of the remaining model-data discrepancies appear related to the neglect of aerosol size, age, and air mass characteristics in estimating tracer solubility. Next, we develop the Mass-Age Tracking method (MAT) to efficiently and accurately estimate the mass-weighted age of tracers. We apply MAT to four sizes of desert dust aerosol and simulate, for the first time, global distributions of aerosol age in the atmosphere and at deposition. These dust size and age distributions at deposition, together with independent information on air mass acidity, allow us to test two simple yet plausible models for predicting the dissolution of mineral dust iron and aluminum during atmospheric transport. These models represent aerosol solubility as controlled (1) by a diffusive process leaching nutrients from the dust into equilibrium with the liquid water coating or (2) by a process that continually dissolves nutrients in proportion to the particle surface area. The surface-controlled model better captures the spatial pattern of observed solubility in the Atlantic. Neither model improves previous estimates of the solubility in the Pacific, nor do they significantly improve the global BEC simulation of dissolved iron or aluminum.

  8. Design and Demonstration of a Miniature Lidar System for Rover Applications

    NASA Technical Reports Server (NTRS)

    Robinson, Benjamin

    2011-01-01

    Public awareness of harmful human environmental effects such as global warming has increased greatly in recent years and researchers have increased their efforts in gaining more knowledge about the Earth's atmosphere. Natural and man-made processes pose threats to the environment and human life, so knowledge of all atmospheric processes is necessary. Ozone and aerosols are important factors in many atmospheric processes and active remote sensing techniques provide a way to analyze their quantity and distribution. A compact ground-based lidar system for a robotic platform meant for atmospheric aerosol measurements was designed, tested, and evaluated. The system will eventually be deployed for ozone and aerosol measurements in Mars and lunar missions to improve our knowledge and understanding of atmospheres on Mars and the Moon. Atmospheric testing was performed to test the operability of the receiver system to acquire the lidar return signal from clouds and aerosols.

  9. Contamination Control in Hybrid Microelectronic Modules. Part 1: Identification of Critical Process and Contaminants

    NASA Technical Reports Server (NTRS)

    Himmel, R. P.

    1975-01-01

    Various hybrid processing steps, handling procedures, and materials are examined in an attempt to identify sources of contamination and to propose methods for the control of these contaminants. It is found that package sealing, assembly, and rework are especially susceptible to contamination. Moisture and loose particles are identified as the worst contaminants. The points at which contaminants are most likely to enter the hybrid package are also identified, and both general and specific methods for their detection and control are developed. In general, the most effective controls for contaminants are: clean working areas, visual inspection at each step of the process, and effective cleaning at critical process steps. Specific methods suggested include the detection of loose particles by a precap visual inspection, by preseal and post-seal electrical testing, and by a particle impact noise test. Moisture is best controlled by sealing all packages in a clean, dry, inert atmosphere after a thorough bake-out of all parts.

  10. THE EFFECTS ON ACHIEVEMENT TEST RESULTS OF VARYING CONDITIONS OF EXPERIMENTAL ATMOSPHERE, NOTICE OF TEST, TEST ADMINISTRATION, AND TEST SCORING.

    ERIC Educational Resources Information Center

    GOODWIN, WILLIAM L.; AND OTHERS

    NULL HYPOTHESES WERE TESTED TO DETERMINE THE DIFFERENTIAL EFFECTS OF (1) EXPERIMENTAL ATMOSPHERE AND ABSENCE OF SAME, (2) NOTICE OF TEST (10 SCHOOL DAYS) AND NO NOTICE (1 SCHOOL DAY), (3) TEACHER ADMINISTRATION AND OUTSIDE ADMINISTRATION OF TESTS, AND (4) TEACHER SCORING AND OUTSIDE SCORING OF TESTS. SIXTH-GRADE CLASSES (N=64), EACH FROM A…

  11. Demonstration of Technologies for Remote and in Situ Sensing of Atmospheric Methane Abundances - a Controlled Release Experiment

    NASA Astrophysics Data System (ADS)

    Aubrey, A. D.; Thorpe, A. K.; Christensen, L. E.; Dinardo, S.; Frankenberg, C.; Rahn, T. A.; Dubey, M.

    2013-12-01

    It is critical to constrain both natural and anthropogenic sources of methane to better predict the impact on global climate change. Critical technologies for this assessment include those that can detect methane point and concentrated diffuse sources over large spatial scales. Airborne spectrometers can potentially fill this gap for large scale remote sensing of methane while in situ sensors, both ground-based and mounted on aerial platforms, can monitor and quantify at small to medium spatial scales. The Jet Propulsion Laboratory (JPL) and collaborators recently conducted a field test located near Casper, WY, at the Rocky Mountain Oilfield Test Center (RMOTC). These tests were focused on demonstrating the performance of remote and in situ sensors for quantification of point-sourced methane. A series of three controlled release points were setup at RMOTC and over the course of six experiment days, the point source flux rates were varied from 50 LPM to 2400 LPM (liters per minute). During these releases, in situ sensors measured real-time methane concentration from field towers (downwind from the release point) and using a small Unmanned Aerial System (sUAS) to characterize spatiotemporal variability of the plume structure. Concurrent with these methane point source controlled releases, airborne sensor overflights were conducted using three aircraft. The NASA Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE) participated with a payload consisting of a Fourier Transform Spectrometer (FTS) and an in situ methane sensor. Two imaging spectrometers provided assessment of optical and thermal infrared detection of methane plumes. The AVIRIS-next generation (AVIRIS-ng) sensor has been demonstrated for detection of atmospheric methane in the short wave infrared region, specifically using the absorption features at ~2.3 μm. Detection of methane in the thermal infrared region was evaluated by flying the Hyperspectral Thermal Emission Spectrometer (HyTES), retrievals which interrogate spectral features in the 7.5 to 8.5 μm region. Here we discuss preliminary results from the JPL activities during the RMOTC controlled release experiment, including capabilities of airborne sensors for total columnar atmospheric methane detection and comparison to results from ground measurements and dispersion models. Potential application areas for these remote sensing technologies include assessment of anthropogenic and natural methane sources over wide spatial scales that represent significant unconstrained factors to the global methane budget.

  12. Lunar Atmosphere and Dust Environment Explorer Integration and Test

    NASA Technical Reports Server (NTRS)

    Wright, Michael R.; McCormick, John L.; Hoffman, Richard G.

    2010-01-01

    Integration and test (I&T) of the Lunar Atmosphere and Dust Environment Explorer (LADEE) is presented. A collaborative NASA project between Goddard Space Flight Center and Ames Research Center, LADEE's mission is to explore the low lunar orbit environment and exosphere for constituents. Its instruments include two spectrometers, a dust detector, and a laser communication technology demonstration. Although a relatively low-cost spacecraft, LADEE has I&T requirements typical of most planetary probes, such as prelaunch contamination control, sterilization, and instrument calibration. To lead to a successful mission, I&T at the spacecraft, instrument, and observatory level must include step-by-step and end-to-end functional, environmental, and performance testing. Due to its compressed development schedule, LADEE I&T planning requires adjusting test flows and sequences to account for long-lead critical-path items and limited spares. A protoflight test-level strategy is also baselined. However, the program benefits from having two independent but collaborative teams of engineers, managers, and technicians that have a wealth of flight project experience. This paper summarizes the LADEE I&T planning, flow, facilities, and probe-unique processes. Coordination of requirements and approaches to I&T when multiple organizations are involved is discussed. Also presented are cost-effective approaches to I&T that are transferable to most any spaceflight project I&T program.

  13. Design of a Controllable Weather Balloon to Fly on Mars

    NASA Astrophysics Data System (ADS)

    Ivie, Benjamin

    As the National Aeronautics and Space Administration (NASA) moves closer towards placing humans on Mars, prediction of the weather on the planet becomes more vital to ensure the safety of the astronauts. Currently on Mars NASA has land based weather stations on the rovers and a few satellites orbiting the planet that help to predict the weather. They also use Earth based telescopes to look at the Martian atmosphere similar to what an orbiting satellite would [1]. These resources provide information about what the weather is like on the surface and what the weather looks like from space but there is little information from inside the atmosphere. Having a device that can fly through the atmosphere and collect data would enable scientists to generate more accurate models of the weather on Mars. Another use for these devices could be to get aerial photographs of the planet, which could help to determine possible sites for future exploration. Also the Martian air could be collected and analyzed to determine its composition and whether there could be any airborne signs of life. The research presented in this thesis is a first step towards designing a device to fly on Mars and take weather data. A lifting type is selected and through test flights on Earth the design is modified until a workable platform for flight testing is achieved. Once it is determined, the design is scaled to be able to fly in the Martian atmosphere.

  14. Oxygen Concentration Flammability Threshold Tests for the Constellation Program

    NASA Technical Reports Server (NTRS)

    Williams, James H.

    2007-01-01

    CEV atmosphere will likely change because craft will be used as LEO spacecraft, lunar spacecraft, orbital spacecraft. Possible O2 % increase and overall pressure decrease pressure vessel certs on spacecraft. Want 34% minimum threshold. Higher, better when atmosphere changes. WSTF suggests testing all materials/components to find flammability threshold, pressure and atmosphere.

  15. Atmospheric characterization on the Kennedy Space Center Shuttle Landing Facility

    NASA Astrophysics Data System (ADS)

    Ko, Jonathan; Coffaro, Joseph; Wu, Chensheng; Paulson, Daniel; Davis, Christopher

    2017-08-01

    Large temperature gradients are a known source of strong atmospheric turbulence conditions. Often times these areas of strong turbulence conditions are also accompanied by conditions that make it difficult to conduct long term optical atmospheric tests. The Shuttle Landing Facility (SLF) at the Kennedy Space Center (KSC) provides a prime testing environment that is capable of generating strong atmospheric turbulence yet is also easily accessible for well instrumented testing. The Shuttle Landing Facility features a 5000 m long and 91 m wide concrete runway that provides ample space for measurements of atmospheric turbulence as well as the opportunity for large temperature gradients to form as the sun heats the surface. We present the results of a large aperture LED scintillometer, a triple aperture laser scintillometer, and a thermal probe system that were used to calculate a path averaged and a point calculation of Cn2. In addition, we present the results of the Plenoptic Sensor that was used to calculate a path averaged Cn2 value. These measurements were conducted over a multi-day continuous test with supporting atmospheric and weather data provided by the University of Central Florida.

  16. Deriving meteorological variables across Africa for the study and control of vector-borne disease: a comparison of remote sensing and spatial interpolation of climate

    PubMed Central

    Hay, S. I.; Lennon, J. J.

    2012-01-01

    Summary This paper presents the results of an investigation into the utility of remote sensing (RS) using meteorological satellites sensors and spatial interpolation (SI) of data from meteorological stations, for the prediction of spatial variation in monthly climate across continental Africa in 1990. Information from the Advanced Very High Resolution Radiometer (AVHRR) of the National Oceanic and Atmospheric Administration’s (NOAA) polar-orbiting meteorological satellites was used to estimate land surface temperature (LST) and atmospheric moisture. Cold cloud duration (CCD) data derived from the High Resolution Radiometer (HRR) on-board the European Meteorological Satellite programme’s (EUMETSAT) Meteosat satellite series were also used as a RS proxy measurement of rainfall. Temperature, atmospheric moisture and rainfall surfaces were independently derived from SI of measurements from the World Meteorological Organization (WMO) member stations of Africa. These meteorological station data were then used to test the accuracy of each methodology, so that the appropriateness of the two techniques for epidemiological research could be compared. SI was a more accurate predictor of temperature, whereas RS provided a better surrogate for rainfall; both were equally accurate at predicting atmospheric moisture. The implications of these results for mapping short and long-term climate change and hence their potential for the study and control of disease vectors are considered. Taking into account logistic and analytical problems, there were no clear conclusions regarding the optimality of either technique, but there was considerable potential for synergy. PMID:10203175

  17. Deriving meteorological variables across Africa for the study and control of vector-borne disease: a comparison of remote sensing and spatial interpolation of climate.

    PubMed

    Hay, S I; Lennon, J J

    1999-01-01

    This paper presents the results of an investigation into the utility of remote sensing (RS) using meteorological satellites sensors and spatial interpolation (SI) of data from meteorological stations, for the prediction of spatial variation in monthly climate across continental Africa in 1990. Information from the Advanced Very High Resolution Radiometer (AVHRR) of the National Oceanic and Atmospheric Administration's (NOAA) polar-orbiting meteorological satellites was used to estimate land surface temperature (LST) and atmospheric moisture. Cold cloud duration (CCD) data derived from the High Resolution Radiometer (HRR) on-board the European Meteorological Satellite programme's (EUMETSAT) Meteosat satellite series were also used as a RS proxy measurement of rainfall. Temperature, atmospheric moisture and rainfall surfaces were independently derived from SI of measurements from the World Meteorological Organization (WMO) member stations of Africa. These meteorological station data were then used to test the accuracy of each methodology, so that the appropriateness of the two techniques for epidemiological research could be compared. SI was a more accurate predictor of temperature, whereas RS provided a better surrogate for rainfall; both were equally accurate at predicting atmospheric moisture. The implications of these results for mapping short and long-term climate change and hence their potential for the study and control of disease vectors are considered. Taking into account logistic and analytical problems, there were no clear conclusions regarding the optimality of either technique, but there was considerable potential for synergy.

  18. On Quality Control Procedures Being Adopted for TRMM LBA and KWAJEX Soundings Data Sets

    NASA Technical Reports Server (NTRS)

    Roy, B.; Halverson, Jeffrey B.; Starr, David OC. (Technical Monitor)

    2001-01-01

    During NASA's Tropical Rainfall Measuring Mission (TRMM) field campaigns Large Scale Biosphere Atmosphere (LBA) held in Amazonia (Brazil) in the period January- February, 1999, and the Kwajalein Experiment (KWAJEX) held in the Republic of Marshall Islands in the period between August-September, 1999, extensive radiosonde observations (raob) were collected using VIZ and Vaisala sondes which have different response characteristics. In all, 320 raob for LBA and 972 fixed raob for KWAJEX have been obtained and are being processed. Most atmospheric sensible heat source (Q1) and apparent moisture sink (Q2) budget studies are based on sounding data, and the accuracy of the raob is important especially in regions of deep moist convection. A data quality control (QC) project has been initiated at GSFC by the principal investigator (JBH), and this paper addresses some of the quantitative findings for the level I and II QC procedures. Based on these quantitative assessment of sensor (or system) biases associated with each type of sonde, the initial data repair work will be started. Evidence of moisture biases between the two different sondes (VIZ and Vaisala) has been shown earlier by Halverson et al. (2000). Vaisala humidity sensors are found to have a low-level dry bias in the boundary layer, whereas above 600 mb the VIZ sensor tends to register a dryer atmosphere. All raob data were subjected to a limit check based on an algorithm already well tested for the raob data obtained during the Tropical Ocean Global Atmosphere (TOGA-COARE).

  19. Aerodynamic and Aeroacoustic Wind Tunnel Testing of the Orion Spacecraft

    NASA Technical Reports Server (NTRS)

    Ross, James C.

    2011-01-01

    The Orion aerodynamic testing team has completed more than 40 tests as part of developing the aerodynamic and loads databases for the vehicle. These databases are key to achieving good mechanical design for the vehicle and to ensure controllable flight during all potential atmospheric phases of a mission, including launch aborts. A wide variety of wind tunnels have been used by the team to document not only the aerodynamics but the aeroacoustic environment that the Orion might experience both during nominal ascents and launch aborts. During potential abort scenarios the effects of the various rocket motor plumes on the vehicle must be accurately understood. The Abort Motor (AM) is a high-thrust, short duration motor that rapidly separates Orion from its launch vehicle. The Attitude Control Motor (ACM), located in the nose of the Orion Launch Abort Vehicle, is used for control during a potential abort. The 8 plumes from the ACM interact in a nonlinear manner with the four AM plumes which required a carefully controlled test to define the interactions and their effect on the control authority provided by the ACM. Techniques for measuring dynamic stability and for simulating rocket plume aerodynamics and acoustics were improved or developed in the course of building the aerodynamic and loads databases for Orion.

  20. 40 CFR Table B-2 to Subpart B of... - Test Atmospheres

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of ASTM Standards, American Society for Testing and Materials, 1916 Race St., Philadelphia, PA..., American Society for Testing and Materials, 1916 Race St., Philadelphia, PA 19103. ... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Test Atmospheres B Table B-2 to Subpart...

  1. 40 CFR Table B-2 to Subpart B of... - Test Atmospheres

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... of ASTM Standards, American Society for Testing and Materials, 1916 Race St., Philadelphia, PA..., American Society for Testing and Materials, 1916 Race St., Philadelphia, PA 19103. ... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Test Atmospheres B Table B-2 to Subpart...

  2. 40 CFR Table B-2 to Subpart B of... - Test Atmospheres

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of ASTM Standards, American Society for Testing and Materials, 1916 Race St., Philadelphia, PA..., American Society for Testing and Materials, 1916 Race St., Philadelphia, PA 19103. ... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Test Atmospheres B Table B-2 to Subpart...

  3. Effect of thermal stability/complex terrain on wind turbine model(s): a wind tunnel study to address complex atmospheric conditions

    NASA Astrophysics Data System (ADS)

    Guala, M.; Hu, S. J.; Chamorro, L. P.

    2011-12-01

    Turbulent boundary layer measurements in both wind tunnel and in the near-neutral atmospheric surface layer revealed in the last decade the significant contribution of the large scales of motions to both turbulent kinetic energy and Reynolds stresses, for a wide range of Reynolds number. These scales are known to grow throughout the logarithmic layer and to extend several boundary layer heights in the streamwise direction. Potentially, they are a source of strong unsteadiness in the power output of wind turbines and in the aerodynamic loads of wind turbine blades. However, the large scales in realistic atmospheric conditions deserves further study, with well controlled boundary conditions. In the atmospheric wind tunnel of the St. Anthony Falls Laboratory, with a 16 m long test section and independently controlled incoming flow and floor temperatures, turbulent boundary layers in a range of stability conditions, from the stratified to the convective case, can be reproduced and monitored. Measurements of fluctuating temperature, streamwise and wall normal velocity components are simultaneously obtained by an ad hoc calibrated and customized triple-wire sensor. A wind turbine model with constant loading DC motor, constant tip speed ratio, and a rotor diameter of 0.128m is used to mimic a large full scale turbine in the atmospheric boundary layer. Measurements of the fluctuating voltage generated by the DC motor are compared with measurements of the blade's angular velocity by laser scanning, and eventually related to velocity measurements from the triple-wire sensor. This study preliminary explores the effect of weak stability and complex terrain (through a set of spanwise aligned topographic perturbations) on the large scales of the flow and on the fluctuations in the wind turbine(s) power output.

  4. Radiometric sounding system

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

    Whiteman, C.D.; Anderson, G.A.; Alzheimer, J.M.

    1995-04-01

    Vertical profiles of solar and terrestrial radiative fluxes are key research needs for global climate change research. These fluxes are expected to change as radiatively active trace gases are emitted to the earth`s atmosphere as a consequence of energy production and industrial and other human activities. Models suggest that changes in the concentration of such gases will lead to radiative flux divergences that will produce global warming of the earth`s atmosphere. Direct measurements of the vertical variation of solar and terrestrial radiative fluxes that lead to these flux divergences have been largely unavailable because of the expense of making suchmore » measurements from airplanes. These measurements are needed to improve existing atmospheric radiative transfer models, especially under the cloudy conditions where the models have not been adequately tested. A tethered-balloon-borne Radiometric Sounding System has been developed at Pacific Northwest Laboratory to provide an inexpensive means of making routine vertical soundings of radiative fluxes in the earth`s atmospheric boundary layer to altitudes up to 1500 m above ground level. Such vertical soundings would supplement measurements being made from aircraft and towers. The key technical challenge in the design of the Radiometric Sounding System is to develop a means of keeping the radiometers horizontal while the balloon ascends and descends in a turbulent atmospheric environment. This problem has been addressed by stabilizing a triangular radiometer-carrying platform that is carried on the tetherline of a balloon sounding system. The platform, carried 30 m or more below the balloon to reduce the balloon`s effect on the radiometric measurements, is leveled by two automatic control loops that activate motors, gears and pulleys when the platform is off-level. The sensitivity of the automatic control loops to oscillatory motions of various frequencies and amplitudes can be adjusted using filters.« less

  5. KSC-97PC1009

    NASA Image and Video Library

    1997-07-07

    The International Extreme Ultraviolet Hitchhiker-2 (IEH-2) payload rests in a work stand in the Space Station Processing Facility prior to its trip out to Launch Pad 39A for installation into the payload bay of the Space Shuttle Orbiter Discovery for the STS-85 mission. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system. The Technology Applications and Science-1 (TAS-1) payload is another series of experiments that will be conducted during the 11-day mission in Discovery’s payload bay. The TAS-1 holds seven separate experiments that will provide data on the Earth’s topography and atmosphere, study the sun’s energy, and test new thermal control devices, as well as several student-developed experiments. Other STS-85 payloads include the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2). The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth’s middle atmosphere. The CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth’s atmosphere

  6. KSC-97PC1030

    NASA Image and Video Library

    1997-07-10

    KENNEDY SPACE CENTER, Fla. -- The payload canister containing the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2) payload for the STS-85 mission is hoisted to the Payload Changeout Room (PCR) at Launch Pad 39A. Also in the canister are the Technology Applications and Science-1 (TAS-1) and International Extreme Ultraviolet Hitchhiker-2 (IEH-2) payloads. All three will be transferred from the PCR into the payload bay of the Space Shuttle Orbiter Discovery after the space vehicle arrives at the pad. The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth’s middle atmosphere. During the 11-day mission, the CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth’s atmosphere. The TAS-1 holds seven separate experiments that will provide data on the Earth’s topography and atmosphere, study the sun’s energy, and test new thermal control devices, as well as several student-developed experiments. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system

  7. CRISTA-SPAS is placed in the PCR at LC 39A

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A payload canister in the Payload Changeout Room (PCR) at Launch Pad 39A holds the Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere-Shuttle Pallet Satellite-2 (CRISTA-SPAS-2) payload for the STS-85 mission (center), as well as the Technology Applications and Science-1 (TAS-1) (top) and International Extreme Ultraviolet Hitchhiker-2 (IEH-2) (bottom) payloads. All three will be transferred from the PCR into the payload bay of the Space Shuttle Orbiter Discovery after the space vehicle arrives at the pad. The CRISTA is a system of three telescopes and four spectrometers to measure infrared radiation emitted by the Earth's middle atmosphere. During the 11-day mission, the CRISTA-SPAS-2 free-flying satellite will be deployed from Discovery and retrieved later in the flight. Also onboard the satellite will be the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) to measure ultraviolet radiation emitted and scattered by the Earth's atmosphere. The TAS-1 holds seven separate experiments that will provide data on the Earth's topography and atmosphere, study the sun's energy, and test new thermal control devices, as well as several student- developed experiments. The IEH-2 experiments will study ultraviolet radiation from stars, the sun and in the solar system.

  8. LOW-GLOBAL-WARMING CHEMICALS AND REFRIGERANT TECHNOLOGIES (ATMOSPHERIC PROTECTION BRANCH, APPCD, NRMRL)

    EPA Science Inventory

    The Atmospheric Protection Branch's Refrigeration Applications Laboratory has the capability to test several types of refrigeration equipment with various refrigerants. Refrigeration compressors are tested according to the ANSI/ASHRAE 23-1993 Test Standard and under various oper...

  9. Treatment of atomic and molecular line blanketing by opacity sampling. [atmospheric optics - stellar atmospheres

    NASA Technical Reports Server (NTRS)

    Johnson, H. R.; Krupp, B. M.

    1975-01-01

    An opacity sampling (OS) technique for treating the radiative opacity of large numbers of atomic and molecular lines in cool stellar atmospheres is presented. Tests were conducted and results show that the structure of atmospheric models is accurately fixed by the use of 1000 frequency points, and 500 frequency points is often adequate. The effects of atomic and molecular lines are separately studied. A test model computed by using the OS method agrees very well with a model having identical atmospheric parameters computed by the giant line (opacity distribution function) method.

  10. Free Enterprise: Contributions of the Approach and Landing Test (ALT) Program to the Development of the Space Shuttle Orbiter

    NASA Technical Reports Server (NTRS)

    Merlin, Peter W.

    2006-01-01

    The space shuttle orbiter was the first spacecraft designed with the aerodynamic characteristics and in-atmosphere handling qualities of a conventional airplane. In order to evaluate the orbiter's flight control systems and subsonic handling characteristics, a series of flight tests were undertaken at NASA Dryden Flight Research Center in 1977. A modified Boeing 747 Shuttle Carrier Aircraft carried the Enterprise, a prototype orbiter, during eight captive tests to determine how well the two vehicles flew together and to test some of the orbiter s systems. The free-flight phase of the ALT program allowed shuttle pilots to explore the orbiter's low-speed flight and landing characteristics. The Enterprise provided realistic, in-flight simulations of how subsequent space shuttles would be flown at the end of an orbital mission. The fifth free flight, with the Enterprise landing on a concrete runway for the first time, revealed a problem with the space shuttle flight control system that made it susceptible to pilot-induced oscillation, a potentially dangerous control problem. Further research using various aircraft, particularly NASA Dryden's F-8 Digital-Fly-By-Wire testbed, led to correction of the problem before the first Orbital Test Flight.

  11. Remote sensing applications for diagnostics of the radioactive pollution of the ground surface and in the atmosphere

    NASA Astrophysics Data System (ADS)

    Pulinets, Sergey; Ouzounov, Dimitar; Boyarchuk, Kirill; Laverov, Nikolay

    2013-04-01

    Radioactive pollution due to its air ionization activity can drastically change the atmospheric boundary layer conductivity (what was experimentally proved during period of nuclear tests in atmosphere) and through the global electric circuit produce anomalous variations in atmosphere. As additional effect the ions created due to air ionization serve as centers of water vapor condensation and nucleation of aerosol-size particles. This process is accompanied by latent heat release. Both anomalies (ionospheric and thermal) can be controlled by remote sensing technique both from satellites (IR sensors and ionospheric probes) and from ground (GPS receivers, ground based ionosondes, VLF propagation sounding, ground measurements of the air temperature and humidity). We monitored the majority of transient events (Three-Mile Island and Chernobyl nuclear power plant emergencies) and stationary sources such as Gabon natural nuclear reactor, sites of underground nuclear tests, etc. and were able to detect thermal anomalies and for majority of cases - the ionospheric anomalies as well. Immediately after the March 11, 2011 earthquake and tsunami in Japan we started to continuously survey the long-wavelength energy flux (10-13 microns) measurable at top of the atmosphere from POES/NOAA/AVHRR polar orbit satellites. Our preliminary results show the presence of hot spots on the top of the atmosphere over the Fukushima Daiichi Nuclear Power Plant (FDNPP) and due to their persistence over the same region they are most likely not of meteorological origin. On March 14 and 21 we detected a significant increase in radiation at the top of the atmosphere which also coincides with a reported radioactivity gas leaks from the FDNPP. After March 21 the intensity of energy flux in atmosphere started to decline, which has been confirmed by ground radiometer network. We were able to detect with ground based ionosonde the ionospheric anomaly associated with the largest radioactive release on March 21.We are presenting new theoretical estimates and results of experimental measurements showing that the heat flux released during ionization of the atmospheric boundary layer under significant radioactive pollution is sufficient for recording anomalous heat fluxes using the means of remote sounding (infrared radiometers) installed on satellites, and ionospheric anomalies are generated due to changes of the boundary layer conductivity.

  12. Jason Roadman | NREL

    Science.gov Websites

    using trained raptors, metrology, storm chasing, and wind tunnel testing of atmospheric turbulence. He Wind tunnel testing of atmospheric turbulence Education B.S. in Aerospace Engineering from Virginia

  13. Technical Update: Johnson Space Center system using a solid electrolytic cell in a remote location to measure oxygen fugacities in CO/CO2 controlled-atmosphere furnaces

    NASA Technical Reports Server (NTRS)

    Jurewicz, A. J. G.; Williams, R. J.; Le, L.; Wagstaff, J.; Lofgren, G.; Lanier, A.; Carter, W.; Roshko, A.

    1993-01-01

    Details are given for the design and application of a (one atmosphere) redox-control system. This system differs from that given in NASA Technical Memorandum 58234 in that it uses a single solid-electrolytic cell in a remote location to measure the oxygen fugacities of multiple CO/CO2 controlled-atmosphere furnaces. This remote measurement extends the range of sample-furnace conditions that can be measured using a solid-electrolytic cell, and cuts costs by extending the life of the sensors and by minimizing the number of sensors in use. The system consists of a reference furnace and an exhaust-gas manifold. The reference furnace is designed according to the redox control system of NASA Technical Memorandum 58234, and any number of CO/CO2 controlled-atmosphere furnaces can be attached to the exhaust-gas manifold. Using the manifold, the exhaust gas from individual CO/CO2 controlled atmosphere furnaces can be diverted through the reference furnace, where a solid-electrolyte cell is used to read the ambient oxygen fugacity. The oxygen fugacity measured in the reference furnace can then be used to calculate the oxygen fugacity in the individual CO/CO2 controlled-atmosphere furnace. A BASIC computer program was developed to expedite this calculation.

  14. Lightning control system using high power microwave FEL

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

    Shiho, M.; Watanbe, A.; Kawasaki, S.

    A research project for developing a thunder lightning control system using an induction linac based high power microwave free electron laser (FEL) started at JAERI The system will produce weakly ionized plasma rod in the atmosphere by high power microwaves and control a lightning path, away from , e. g., nuclear power stations and rocket launchers. It has been known that about MW/cm{sup 2} power density is enough for the atmospheric breakdown in the microwave region, and which means high power microwave FEL with GW level output power is feasible for atmospheric breakdown, and accordingly is feasible for thunder lightningmore » control tool with making a conductive plasma channel in the atmosphere. From the microwave attenuation consideration in the atmosphere, FEL of 35GHz(0.13dB/km), 90GHz(0.35dB/km), 140GHz(1.7dB/km), and of 270 GHz(4.5dB/km) are the best candidates for the system. Comparing with other proposed lightning control system using visible or ultraviolet laser, the system using microwave has an advantage that microwave suffers smaller attenuation by rain or snow which always exist in the real atmospheric circumstances when lightning occurs.« less

  15. On the attitude control and flight result of winged reentry test vehicle

    NASA Astrophysics Data System (ADS)

    Kawaguchi, Jun'ichiro; Inatani, Yoshifumi; Yonemoto, Koichi; Hinada, Motoki

    The Institute of Space and Astronautical Science (ISAS) has been studying the unmanned winged space vehicle HIMES (HIghly Maneuverable Engineering Space vehicle) for a decade and successfully carried out sub-sonic Gliding Flight Experiments several years ago, which was followed by Reentry Flight Experiment, utilizing so called 'Rockoon' method, in September of 1988, which failed due to the unexpected burst of the balloon. ISAS conducted it again making use of refined 'Rockoon' scheme in February of 1992. In spite of its small bulk property, it was equipped with not only a reaction control system (RCS) but a surface control system (SCS) capability as well, which enabled it to make a successful flight under both vacuum and atmospheric circumstances. The highest Mach number exceeded 3.5 and the highest altitude was a bit lower to 67 km. Switching from reaction control to surface control was one of the essential engineering interests in the flight like this. Supersonic autonomous flight control with high angle of attack was also what should be established through this, since in general it inevitably carries inherent lateral instability. A flight test this time revealed those features and characteristics quite well. This paper deals with the attitude control strategy with three-axis Motion Simulation Test as well as the flight results.

  16. Thermal effects of an ICL-based mid-infrared CH 4 sensor within a wide atmospheric temperature range

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

    Ye, Weilin; Zheng, Chuantao; Sanchez, Nancy P.

    Here, thermal effects of an interband cascade laser (ICL) based mid-infrared methane (CH 4) sensor that uses long-path absorption spectroscopy were studied. The sensor performance in the laboratory at a constant temperature of ~ 25°C was measured for 5 hours and its Allan deviation was ~ 2 ppbv with a 1 s averaging time. A LabVIEW-based simulation program was developed to study thermal effects on infrared absorption and a temperature compensation technique was developed to control such effects. An environmental test chamber was employed to investigate thermal effects that occur in the sensor system with variation of the test chambermore » temperature between 10 and 30°C. The thermal response of the sensor in a laboratory setting was observed using a 2.1 ppm CH 4 standard gas sample. indoor/outdoor CH 4 measurements were conducted to evaluate the sensor performance within a wide atmospheric temperature range.« less

  17. Thermal effects of an ICL-based mid-infrared CH 4 sensor within a wide atmospheric temperature range

    DOE PAGES

    Ye, Weilin; Zheng, Chuantao; Sanchez, Nancy P.; ...

    2018-01-31

    Here, thermal effects of an interband cascade laser (ICL) based mid-infrared methane (CH 4) sensor that uses long-path absorption spectroscopy were studied. The sensor performance in the laboratory at a constant temperature of ~ 25°C was measured for 5 hours and its Allan deviation was ~ 2 ppbv with a 1 s averaging time. A LabVIEW-based simulation program was developed to study thermal effects on infrared absorption and a temperature compensation technique was developed to control such effects. An environmental test chamber was employed to investigate thermal effects that occur in the sensor system with variation of the test chambermore » temperature between 10 and 30°C. The thermal response of the sensor in a laboratory setting was observed using a 2.1 ppm CH 4 standard gas sample. indoor/outdoor CH 4 measurements were conducted to evaluate the sensor performance within a wide atmospheric temperature range.« less

  18. A Study of the Effects of Large Scale Gust Generation in a Small Scale Atmospheric Wind Tunnel: Application to Micro Aerial Vehicles

    NASA Astrophysics Data System (ADS)

    Roadman, Jason; Mohseni, Kamran

    2009-11-01

    Modern technology operating in the atmospheric boundary layer could benefit from more accurate wind tunnel testing. While scaled atmospheric boundary layer tunnels have been well developed, tunnels replicating portions of the turbulence of the atmospheric boundary layer at full scale are a comparatively new concept. Testing at full-scale Reynolds numbers with full-scale turbulence in an ``atmospheric wind tunnel'' is sought. Many programs could utilize such a tool including that of Micro Aerial Vehicles (MAVs) and other unmanned aircraft, the wind energy industry, fuel efficient vehicles, and the study of bird and insect fight. The construction of an active ``gust generator'' for a new atmospheric tunnel is reviewed and the turbulence it generates is measured utilizing single and cross hot wires. Results from this grid are compared to atmospheric turbulence and it is shown that various gust strengths can be produced corresponding to days ranging from calm to quite gusty. An initial test is performed in the atmospheric wind tunnel whereby the effects of various turbulence conditions on transition and separation on the upper surface of a MAV wing is investigated using oil flow visualization.

  19. FY17 Accomplishments - Testing Facilities and Capabilities at SWiFT, SNL

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

    Berg, Jonathan Charles

    The Scaled Wind Farm Technologies (SWiFT) facility operated by Sandia National Laboratories (SNL) has, in support of the Atmosphere to electrons (A2e) research program, acquired measurements of wind turbine wake dynamics under various atmospheric conditions and while interacting with a downstream wind turbine. SNL researchers, in collaboration with National Renewable Energy Laboratory (NREL) researchers, installed a customized LIDAR system created by the Technical University of Denmark (DTU) in one of the SWiFT wind turbines (Figure 1) and operated that turbine with intentional yaw-versus-winddirection misalignment to study the behavior of the turbine wake under numerous combinations of atmospheric conditions and turbinemore » yaw offsets. The DTU-customized LIDAR provided detailed measurements of the wake’s shape and location at many distances downwind of the turbine (Figure 2). These measurements will benefit wind energy researchers looking to understand wind turbine wake behavior and improve modeling and simulation of wake dynamics, including the “wake steering” affect that is observed when turbine yaw offset is controlled. During the test campaign, two SWiFT wind turbines were operated at the same time to observe the influence of the turbines on each other as the wake of the upwind turbine was observed sweeping over and interacting with the downwind turbine.« less

  20. Qualification testing of secondary sterilizable silver-zinc cells for use in the Jupiter atmospheric entry probe

    NASA Technical Reports Server (NTRS)

    Manzo, M. A.

    1981-01-01

    A series of qualification tests were run on the secondary, sterilizable silver oxide - zinc cell developed at the NASA Lewis Research Center to determine if the cell was capable of providing mission power requirements for the Jupiter atmospheric entry probe. The cells were tested for their ability to survive radiation at the levels predicted for the Jovian atmosphere with no loss of performance. Cell performance was evaluated under various temperature and loading conditions, and the cells were tested under various environmental conditions related to launch and to deceleration into the Jovian atmosphere. The cell performed acceptably except under the required loading at low temperatures. The cell was redesigned to improve low-temperature performance and energy density. The modified cells improved performance at all temperatures. Results of testing cells of both the original and modified designs are discussed.

  1. Effect of Atmospheric-Pressure Cold Plasma on Pathogenic Oral Biofilms and In Vitro Reconstituted Oral Epithelium.

    PubMed

    Delben, Juliana Aparecida; Zago, Chaiene Evelin; Tyhovych, Natalia; Duarte, Simone; Vergani, Carlos Eduardo

    2016-01-01

    Considering the ability of atmospheric-pressure cold plasma (ACP) to disrupt the biofilm matrix and rupture cell structure, it can be an efficient tool against virulent oral biofilms. However, it is fundamental that ACP does not cause damage to oral tissue. So, this study evaluated (1) the antimicrobial effect of ACP on single- and dual-species biofilms of Candida albicans and Staphylococcus aureus as well as (2) the biological safety of ACP on in vitro reconstituted oral epithelium. Standardized cell suspensions of each microorganism were prepared for biofilm culture on acrylic resin discs at 37°C for 48 hours. The biofilms were submitted to ACP treatment at 10 mm of plasma tip-to-sample distance during 60 seconds. Positive controls were penicillin G and fluconazole for S. aureus and C. albicans, respectively. The biofilms were analyzed through counting of viable colonies, confocal laser scanning microscopy, scanning electron microscopy and fluorescence microscopy for detection of reactive oxygen species. The in vitro reconstituted oral epithelium was submitted to similar ACP treatment and analyzed through histology, cytotoxocity test (LDH release), viability test (MTT assay) and imunnohistochemistry (Ki67 expression). All plasma-treated biofilms presented significant log10 CFU/mL reduction, alteration in microorganism/biofilm morphology, and reduced viability in comparison to negative and positive controls. In addition, fluorescence microscopy revealed presence of reactive oxygen species in all plasma-treated biofilms. Low cytotoxicity and high viability were observed in oral epithelium of negative control and plasma group. Histology showed neither sign of necrosis nor significant alteration in plasma-treated epithelium. Ki67-positive cells revealed maintenance of cell proliferation in plasma-treated epithelium. Atmospheric-pressure cold plasma is a promissing approach to eliminate single- and dual-species biofilms of C. albicans and S. aureus without having toxic effects in oral epithelium.

  2. Geochemical cycles of atmospheric gases

    NASA Technical Reports Server (NTRS)

    Walker, J. C. G.; Drever, J. I.

    1988-01-01

    The processes that control the atmosphere and atmospheric changes are reviewed. The geochemical cycles of water vapor, nitrogen, carbon dioxide, oxygen, and minor atmospheric constituents are examined. Changes in atmospheric chemistry with time are discussed using evidence from the rock record and analysis of the present atmosphere. The role of biological evolution in the history of the atmosphere and projected changes in the future atmosphere are considered.

  3. Human Support Technology Research to Enable Exploration

    NASA Technical Reports Server (NTRS)

    Joshi, Jitendra

    2003-01-01

    Contents include the following: Advanced life support. System integration, modeling, and analysis. Progressive capabilities. Water processing. Air revitalization systems. Why advanced CO2 removal technology? Solid waste resource recovery systems: lyophilization. ISRU technologies for Mars life support. Atmospheric resources of Mars. N2 consumable/make-up for Mars life. Integrated test beds. Monitoring and controlling the environment. Ground-based commercial technology. Optimizing size vs capability. Water recovery systems. Flight verification topics.

  4. 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 processing. For the Phase II test the water recovery rate ranged from 95 to 98%, depending on the processor. LMLSTP Phase III, the fourth test of the series, had a duration of 91 days and included four crew members. The test demonstrated an integration of physicochemical and biological technologies for air revitalization, water recovery and waste processing. Wheat supplemented the physicochemical air revitalization systems by providing approximately 25% of the oxygen required for the 4-person crew. The water recovery system included immobilized cell and trickling filter bioreactors for primary water treatment, reverse osmosis and air evaporation systems for secondary water treatment, followed by post processing. The 8 day initial supply of water was recycled through the chamber and crew 10 times over the course of the test. Grain from the wheat together with fresh lettuce from a small growth chamber within the crew chamber provided supplementation to the stored food system, but at a level less than 5% of the crew s caloric requirement. An incinerator was used to demonstrate mineralization of the crew s solid waste, with the combustion products (mainly carbon dioxide) returned to the wheat for conversion to oxygen.

  5. Verification of diffusive and pumped samplers for volatile organic compounds using a controlled atmosphere test facility

    NASA Astrophysics Data System (ADS)

    Martin, Nicholas A.; Leming, Edward J.; Henderson, Malcolm H.; Lipscombe, Robert P.; Black, John K.; Jarvis, Scott D.

    2010-09-01

    There is a requirement to verify the performance of sorbent-based passive or active samplers and to extend their use, where possible, to monitor volatile organic compounds (VOCs) that are known to be photochemical ozone pre-cursors or are relevant to the activities of the petrochemical industry. We report measurements of the 14-day diffusive uptake rates for the VOCs: i-butane (2-methyl propane), n-butane, i-pentane (2-methyl butane), n-pentane, n-hexane, benzene, toluene, and m-xylene (at environmental level concentrations) for industry standard axial samplers (Perkin-Elmer-type samplers) containing the sorbents Carbopack-X, -Z, -B or Tenax-TA. We also present data on back-diffusion, blank levels, and storage for the above sorbents, and describe the simultaneous use of the sorbent Carbopack-X for pumped sampling of certain VOCs. The results were obtained by dosing samplers in a controlled atmosphere test facility (CATFAC) operating under well-defined conditions of concentration, nominal temperature of 20 °C, wind speed of 0.5 m s -1, and relative humidities of 0% and 80%. Field measurements were also obtained to provide supplementary data to support the laboratory study. Results are compared to existing published data, where these are available.

  6. Computation at a coordinate singularity

    NASA Astrophysics Data System (ADS)

    Prusa, Joseph M.

    2018-05-01

    Coordinate singularities are sometimes encountered in computational problems. An important example involves global atmospheric models used for climate and weather prediction. Classical spherical coordinates can be used to parameterize the manifold - that is, generate a grid for the computational spherical shell domain. This particular parameterization offers significant benefits such as orthogonality and exact representation of curvature and connection (Christoffel) coefficients. But it also exhibits two polar singularities and at or near these points typical continuity/integral constraints on dependent fields and their derivatives are generally inadequate and lead to poor model performance and erroneous results. Other parameterizations have been developed that eliminate polar singularities, but problems of weaker singularities and enhanced grid noise compared to spherical coordinates (away from the poles) persist. In this study reparameterization invariance of geometric objects (scalars, vectors and the forms generated by their covariant derivatives) is utilized to generate asymptotic forms for dependent fields of interest valid in the neighborhood of a pole. The central concept is that such objects cannot be altered by the metric structure of a parameterization. The new boundary conditions enforce symmetries that are required for transformations of geometric objects. They are implemented in an implicit polar filter of a structured grid, nonhydrostatic global atmospheric model that is simulating idealized Held-Suarez flows. A series of test simulations using different configurations of the asymptotic boundary conditions are made, along with control simulations that use the default model numerics with no absorber, at three different grid sizes. Typically the test simulations are ∼ 20% faster in wall clock time than the control-resulting from a decrease in noise at the poles in all cases. In the control simulations adverse numerical effects from the polar singularity are observed to increase with grid resolution. In contrast, test simulations demonstrate robust polar behavior independent of grid resolution.

  7. Extending the shelf life of edible flowers with controlled release of 1-methylcyclopropene and modified atmosphere packaging.

    PubMed

    Kou, Liping; Turner, Ellen R; Luo, Yaguang

    2012-05-01

    Edible flowers have great sensory appeal, but their extremely short shelf life limits their commercial usage. Postharvest 1-methylcyclopropene (1-MCP) treatment is used to counter ethylene activity and delay senescence in fresh produce; however, its potential application in edible flowers has not been tested. The objective of this study was to investigate the effect of 1-MCP treatment with modified atmosphere packaging (MAP) on the shelf life of edible flowers. Freshly harvested carnations and snapdragons were packaged in trays with or without 0.5 μL/L of 1-MCP, sealed with a gas permeable film, and stored at 5 °C. Package atmospheres, tissue electrolyte leakage, and flower quality were evaluated on days 0, 7, and 14. Treatment with 1-MCP resulted in significantly slower changes in package headspace O(2), CO(2), and C(2)H(4) partial pressures, maintained higher overall quality of both flower species and reduced electrolyte leakage and abscission in snapdragon. All samples prepared with MAP had significantly reduced dehydration and higher overall quality compared to flowers packaged commercially in plastic clamshell containers. Treatments with controlled release of 1-MCP and MAP significantly extended storage life of edible carnation and snapdragon flowers. © 2012 Institute of Food Technologists®

  8. Efficacy of 1-methylcyclopropene on the mitigation of storage disorders of "Rocha" pear under normal refrigerated and controlled atmospheres.

    PubMed

    Almeida, Domingos Pf; Carvalho, Rita; Dupille, Eve

    2016-07-01

    Alternatives are needed for long-term preservation of European pears (Pyrus communis L.) after the ban on diphenylamine. "Rocha" pear fruit harvested at commercial maturity were treated with 1-methylcyclopropene (1-methylcyclopropene, SmartFresh™) and diphenylamine and stored at 0 ℃, 90-95% relative humidity, under normal atmosphere for up to six months or under controlled atmosphere (controlled atmosphere, 3 kPa O2 + 0.7 kPa CO2) for up to 9.4 months. At 312 nl l(-1), 1-methylcyclopropene reduced softening and yellowing, and increased soluble solids content during shelf life in comparison with fruit treated with diphenylamine. 1-Methylcyclopropene at 312 nl l(-1) was also more effective than diphenylamine in reducing superficial scald and internal browning disorders. 1-Methylcyclopropene at 150 nl l(-1) had little effect on ripening-related changes but was effective against physiological disorders of pears stored in regular atmosphere or under controlled atmosphere. Delayed controlled atmosphere slightly reduced internal browning disorders but increased superficial scald. 1-Methylcyclopropene at 312 nl l(-1) reduced physiological disorders in "Rocha" pear under refrigerated storage and delayed ripening-related softening and color changes during shelf life. At 150 nl l(-1), 1-methylcyclopropene is as effective as diphenylamine against storage disorders without ripening impairment. © The Author(s) 2015.

  9. KENNEDY SPACE CENTER, FLA. - On a tour of the KSC Beach Corrosion Test Site, Testbed Manager Louis MacDowell (right) explains to Center Director Jim Kennedy about the test blocks being used to test a newly developed coating to protect steel inside concrete. Between MacDowell and Kennedy are Dr. Paul Hintze and Lead Scientist Dr. Luz Marina Calle. The KSC Beach Corrosion Test Site was established in the 1960s and has provided more than 30 years of historical information on the long-term performance of many materials in use at KSC and other locations around the world. Located 100 feet from the Atlantic Ocean approximately 1 mile south of the Space Shuttle launch sites, the test facility includes an atmospheric exposure site, a flowing seawater exposure site, and an on-site electrochemistry laboratory and monitoring station. The beach laboratory is used to conduct real-time corrosion experiments and provides for the remote monitoring of surrounding weather conditions. The newly added flowing seawater immersion facility provides for the immersion testing of materials and devices under controlled conditions.

    NASA Image and Video Library

    2003-08-21

    KENNEDY SPACE CENTER, FLA. - On a tour of the KSC Beach Corrosion Test Site, Testbed Manager Louis MacDowell (right) explains to Center Director Jim Kennedy about the test blocks being used to test a newly developed coating to protect steel inside concrete. Between MacDowell and Kennedy are Dr. Paul Hintze and Lead Scientist Dr. Luz Marina Calle. The KSC Beach Corrosion Test Site was established in the 1960s and has provided more than 30 years of historical information on the long-term performance of many materials in use at KSC and other locations around the world. Located 100 feet from the Atlantic Ocean approximately 1 mile south of the Space Shuttle launch sites, the test facility includes an atmospheric exposure site, a flowing seawater exposure site, and an on-site electrochemistry laboratory and monitoring station. The beach laboratory is used to conduct real-time corrosion experiments and provides for the remote monitoring of surrounding weather conditions. The newly added flowing seawater immersion facility provides for the immersion testing of materials and devices under controlled conditions.

  10. Shallow-to-Deep Convection Transition over Land: Atmospheric and surface controls inferred from long-term ground-based observations

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Klein, S. A.

    2016-12-01

    Warm-season decade-long observations are used to investigate mechanisms controlling the transition from shallow to deep convection over land. The data are from the DOE Atmospheric Radiation Measurement Climate Research Facility Southern Great Plains site. The study focuses on two questions: 1) what environmental parameters differ between the two convective regimes: fair-weather shallow cumulus versus late-afternoon deep convection, especially in the late morning a few hours before deep convection begins? And 2) Do convective regimes such as fair-weather shallow cumulus and late-afternoon deep convection have any preferences over soil moisture conditions (dry or wet) and soil moisture heterogeneities? It is found that a more humid environment immediately above the boundary layer is present before the start of late afternoon heavy precipitation events. Greater boundary layer inhomogeneity in moist static energy, temperature, moisture, and horizontal wind before precipitation begins is correlated to larger rain rates at the initial stage of precipitation. Late-afternoon deep convection tends to prefer drier soil conditions with larger surface heterogeneity. This observational study helps our understanding of convective responses to different environmental factors especially surface versus atmospheric controls. This work leads to the establishment of composite cases of different continental convective regimes for large-eddy simulations and single-column tests of climate model parameterizations. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL-ABS-698972

  11. Analysis of anabolic steroids in urine by gas chromatography-microchip atmospheric pressure photoionization-mass spectrometry with chlorobenzene as dopant.

    PubMed

    Hintikka, Laura; Haapala, Markus; Kuuranne, Tiia; Leinonen, Antti; Kostiainen, Risto

    2013-10-18

    A gas chromatography-microchip atmospheric pressure photoionization-tandem mass spectrometry (GC-μAPPI-MS/MS) method was developed for the analysis of anabolic androgenic steroids in urine as their trimethylsilyl derivatives. The method utilizes a heated nebulizer microchip in atmospheric pressure photoionization mode (μAPPI) with chlorobenzene as dopant, which provides high ionization efficiency by producing abundant radical cations with minimal fragmentation. The performance of GC-μAPPI-MS/MS was evaluated with respect to repeatability, linearity, linear range, and limit of detection (LOD). The results confirmed the potential of the method for doping control analysis of anabolic steroids. Repeatability (RSD<10%), linearity (R(2)≥0.996) and sensitivity (LODs 0.05-0.1ng/mL) were acceptable. Quantitative performance of the method was tested and compared with that of conventional GC-electron ionization-MS, and the results were in good agreement. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Arabidopsis seed production limited by CO2 in simulated space experiments

    NASA Technical Reports Server (NTRS)

    Hoshizaki, T.

    1984-01-01

    Several generations of Arabidopsis thaliana were grown axenically from seed to seed on nutrient agar medium. The Arabidopsis plants produce seeds within 30 days after seeding, when grown either in containers open to the ambient atmosphere or in large sealed jars, but not in sealed test tubes. Moreover, the plant height was directly proportional to the size of the sealed container. Periodic analyses of the CO2 levels in the sealed containers has shown a decrease during the first week, but a tenfold increase in the following weeks. It is speculated that, by the end of the second week, the cotyledons entering the senescence stage would release ethylene into the culture atmosphere with a concomitant release of CO2, which in turn would induce further release of ethylene, hastening the senescence process in other tissues. Thus, in a controlled ecological life-support system of a space station, various components of the plant atmosphere may have to be maintained within the prescribed limits.

  13. Microstrip antenna study for Pioneer Saturn/Uranus atmosphere entry probe

    NASA Technical Reports Server (NTRS)

    Kuhlman, E. A.

    1974-01-01

    The design parameters of a microstrip antenna were studied to determine its performance characteristics as affected by an atmospheric entry probe environment. The technical literature was reviewed to identify the known design and performance characteristics. These data were used to evaluate the expected effects of mission environments on the microstrip antenna design proposed for the Saturn/Uranus Atmospheric Entry Probe (SAEP). Radiation patterns and VSWR measurements were made to evaluate the performance in the SAEP thermal environment. Results of the literature search and pattern tests confirm that the microstrip antenna is a good choice as a transmitting antenna on the SAEP. The microstrip antenna is efficient, compact, and well suited to a space environment. The pattern can be controlled with a minimum beamwidth of 60 degrees (air substrate; e.g., honeycomb structure) and a maximum on the order of 100 degrees with higher dielectric constant substrates. The power handling capacity is good and can be improved by covering the antenna with a dielectric cover.

  14. Projected Impact of Climate Change on the Water and Salt Budgets of the Arctic Ocean by a Global Climate Model

    NASA Technical Reports Server (NTRS)

    Miller, James R.; Russell, Gary L.

    1996-01-01

    The annual flux of freshwater into the Arctic Ocean by the atmosphere and rivers is balanced by the export of sea ice and oceanic freshwater. Two 150-year simulations of a global climate model are used to examine how this balance might change if atmospheric greenhouse gases (GHGs) increase. Relative to the control, the last 50-year period of the GHG experiment indicates that the total inflow of water from the atmosphere and rivers increases by 10% primarily due to an increase in river discharge, the annual sea-ice export decreases by about half, the oceanic liquid water export increases, salinity decreases, sea-ice cover decreases, and the total mass and sea-surface height of the Arctic Ocean increase. The closed, compact, and multi-phased nature of the hydrologic cycle in the Arctic Ocean makes it an ideal test of water budgets that could be included in model intercomparisons.

  15. Theory and observations: Model simulations of the period 1955-1985

    NASA Technical Reports Server (NTRS)

    Isaksen, Ivar S. A.; Eckman, R.; Lacis, A.; Ko, Malcolm K. W.; Prather, M.; Pyle, J.; Rodhe, H.; Stordal, Frode; Stolarski, R. S.; Turco, R. P.

    1989-01-01

    The main objective of the theoretical studies presented here is to apply models of stratospheric chemistry and transport in order to understand the processes that control stratospheric ozone and that are responsible for the observed variations. The model calculations are intended to simulate the observed behavior of atmospheric ozone over the past three decades (1955-1985), for which there exists a substantial record of both ground-based and, more recently, satellite measurements. Ozone concentrations in the atmosphere vary on different time scales and for several different causes. The models described here were designed to simulate the effect on ozone of changes in the concentration of such trace gases as CFC, CH4, N2O, and CO2. Changes from year to year in ultraviolet radiation associated with the solar cycle are also included in the models. A third source of variability explicitly considered is the sporadic introduction of large amounts of NO sub x into the stratosphere during atmospheric nuclear tests.

  16. Breadboard CO2 and humidity control system

    NASA Technical Reports Server (NTRS)

    Boehm, A. M.

    1976-01-01

    A regenerable CO2 and humidity control system is being developed for potential use on shuttle as an alternate to the baseline lithium hydroxide (LiOH)/condensing heat exchanger system. The system utilizes a sorbent material, designated HS-C, to adsorb CO2 and water vapor from the cabin atmosphere. The material is regenerated by exposing it to space vacuum. A half-size breadboard system, utilizing a flight representative HS-C canister, was designed, built, and performance tested to shuttle requirements for total CO2 and total humidity removal. The use of a new chemical matrix material allowed significant optimization of the system design by packing the HS-C chemical into the core of a heat exchanger which is manifolded to form two separate and distinct beds. Breadboard system performance was proven by parametric testing and simulated mission testing over the full range of shuttle crew sizes and metabolic loadings. Vacuum desorption testing demonstrated considerable savings in previously projected shuttle vacuum duct sizing.

  17. Drag-Free Control and Drag Force Recovery of Small Satellites

    NASA Technical Reports Server (NTRS)

    Nguyen, Anh N.; Conklin, John W.

    2017-01-01

    Drag-free satellites provide autonomous precision orbit determination, accurately map the static and time varying components of Earth's mass distribution, aid in our understanding of the fundamental force of gravity, and will ultimately open up a new window to our universe through the detection and observation of gravitational waves. At the heart of this technology is a gravitational reference sensor, which (a) contains and shields a free-floating proof mass from all non-gravitational forces, and (b) precisely measures the position of the test mass inside the sensor. Thus, both test mass and spacecraft follow a pure geodesic in spacetime. By tracking the position of a low Earth orbiting drag-free satellite we can directly determine the detailed shape of geodesics and through analysis, the higher order harmonics of the Earths geopotential. This paper explores two different drag-free control systems on small satellites. The first drag-free control system is a continuously compensated single thruster 3-unit CubeSat with a suspension-free spherical proof-mass. A feedback control system commands the thruster and Attitude and Determination Control System to fly the tender spacecraft with respect to the test mass. The spheres position is sensed with a LED-based differential optical shadow sensor, its electric charge controlled by photoemission using UV LEDs, and the spacecraft position is maintained with respect to the sphere using an ion electrospray propulsion system. This configuration is the most fuel-efficient drag-free system possible today. The second drag-free control system is an electro-statically suspended cubical proof-mass that is operated with a low duty cycle, limiting suspension force noise over brief, known time intervals on a small GRACE-II -like satellite. The readout is performed using a laser interferometer, which is immune to the dynamic range limitations of voltage references. This system eliminates the need for a thruster, enabling drag-free control systems for passive satellites. In both cases, the test mass position, GPS tracking data, and commanded actuation, either thrust or suspension system, can be analyzed to estimate the 3-axis drag forces acting on the satellite. The data produces the most precise maps of upper atmospheric drag forces and with additional information, detailed models that describe the dynamics of the upper atmosphere and its impact on all satellites that orbit the Earth. This paper highlights the history, applications, design, laboratory technology development and highly detailed simulation results of each control system.

  18. Design and Demonstration of a Miniature Lidar System for Rover Applications

    NASA Technical Reports Server (NTRS)

    Robinson, Benjamin

    2011-01-01

    Public awareness of harmful human environmental effects such as global warming has increased greatly in recent years and researchers have increased their efforts in gaining more knowledge about the Earth s atmosphere. Natural and man-made processes pose threats to the environment and human life, so knowledge of all atmospheric processes is necessary. Ozone and aerosols are important factors in many atmospheric processes and active remote sensing techniques provide a way to analyze their quantity and distribution. A compact ground-based lidar system for a robotic platform meant for atmospheric aerosol measurements was designed, tested, and evaluated. The system will eventually be deployed for ozone and aerosol measurements in Mars and lunar missions to improve our knowledge and understanding of atmospheres on Mars and the Moon. All of the major subsystems were described in detail and atmospheric testing was performed to test the operability of the receiver system to acquire the lidar return signal from clouds and aerosols. The measured backscattered results are discussed and compared with theoretical results.

  19. Study of development and utilization of a multipurpose atmospheric corrosion sensor

    NASA Technical Reports Server (NTRS)

    Diwan, Ravinder M.; Raman, A.; Bhattacharya, P. K.

    1994-01-01

    There has been a critical need for analyzing various aspects of atmospheric corrosion and for the development of atmospheric corrosion microsensors. The project work has involved the following activities: (1) making of multielectrode corrosion monitors on dielectric substrates; (2) testing them in the laboratory for functional characteristics; (3) preparing a report on the state of the art of atmospheric corrosion sensor development around the world; and (4) corrosion testing of electrochemical changes of sensor specimens and related fog testing. The study included work on the subject of development and utilization of a multipurpose atmospheric corrosion sensor and this report is the annual report on work carried out on this research project. This has included studies on the development of sensors of two designs, stage 1 and stage 2, and with glass and alumina substrate, experimentation and development and characterization of the coating uniformity, aspects of corrosion monitoring, literature search on the corrosion sensors and their development. A state of the art report on atmospheric corrosion sensor development was prepared and submitted.

  20. Mitigation of beam fluctuation due to atmospheric turbulence and prediction of control quality using intelligent decision-making tools.

    PubMed

    Raj, A Arockia Bazil; Selvi, J Arputha Vijaya; Kumar, D; Sivakumaran, N

    2014-06-10

    In free-space optical link (FSOL), atmospheric turbulence causes fluctuations in both intensity and phase of the received beam and impairing link performance. The beam motion is one of the main causes for major power loss. This paper presents an investigation on the performance of two types of controller designed for aiming a laser beam to be at a particular spot under dynamic disturbances. The multiple experiment observability nonlinear input-output data mapping is used as the principal components for controllers design. The first design is based on the Taguchi method while the second is artificial neural network method. These controllers process the beam location information from a static linear map of 2D plane: optoelectronic position detector, as observer, and then generate the necessary outputs to steer the beam with a microelectromechanical mirror: fast steering mirror. The beam centroid is computed using monopulse algorithm. Evidence of suitability and effectiveness of the proposed controllers are comprehensively assessed and quantitatively measured in terms of coefficient of correlation, correction speed, control exactness, centroid displacement, and stability of the receiver signal through the experimental results from the FSO link setup established for the horizontal range of 0.5 km at an altitude of 15.25 m. The test field type is open flat terrain, grass, and few isolated obstacles.

  1. Testing and modeling the influence of reclamation and control methods for reducing nonpoint mercury emissions associated with industrial open pit gold mines.

    PubMed

    Miller, Matthieu B; Gustin, Mae S

    2013-06-01

    Industrial gold mining is a significant source of mercury (Hg) emission to the atmosphere. To investigate ways to reduce these emissions, reclamation and dust and mercury control methods used at open pit gold mining operations in Nevada were studied in a laboratory setting. Using this information along with field data, and building off previous work, total annual Hg emissions were estimated for two active gold mines in northern Nevada. Results showed that capping mining waste materials with a low-Hg substrate can reduce Hg emissions from 50 to nearly 100%. The spraying of typical dust control solutions often results in higher Hg emissions, especially as materials dry after application. The concentrated application of a dithiocarbamate Hg control reagent appears to reduce Hg emissions, but further testing mimicking the actual distribution of this chemical within an active leach solution is needed to make a more definitive assessment.

  2. The controllability of the aeroassist flight experiment atmospheric skip trajectory

    NASA Technical Reports Server (NTRS)

    Wood, R.

    1989-01-01

    The Aeroassist Flight Experiment (AFE) will be the first vehicle to simulate a return from geosynchronous orbit, deplete energy during an aerobraking maneuver, and navigate back out of the atmosphere to a low earth orbit It will gather scientific data necessary for future Aeroasisted Orbitl Transfer Vehicles (AOTV's). Critical to mission success is the ability of the atmospheric guidance to accurately attain a targeted post-aeropass orbital apogee while nulling inclination errors and compensating for dispersions in state, aerodynamic, and atmospheric parameters. In typing to satisfy mission constraints, atmospheric entry-interface (EI) conditions, guidance gains, and trajectory. The results of the investigation are presented; emphasizing the adverse effects of dispersed atmospheres on trajectory controllability.

  3. Experimental evaluation of atmospheric effects on radiometric measurements using the EREP of Skylab. [Salton Sea and Great Salt Lake

    NASA Technical Reports Server (NTRS)

    Chang, D. T. (Principal Investigator); Isaacs, R. G.

    1975-01-01

    The author has identified the following significant results. Test sites were located near the Great Salt Lake and the Salton Sea. Calculations were performed for a set of atmospheric models corresponding to the test sites, in addition to standard models for summer and winter midlatitude atmospheres with respective integrated water vapor amount of 2.4 g/sq cm and 0.9 g/sq cm. Each atmosphere was found to contain an average amount of continental aerosol. Computations were valid for high solar elevation angles. Atmospheric attenuation quantities were computed in addition to simulated EREP S192 radiances.

  4. The Effect of ODC-Free Cleaning Techniques on Bearing Lifetimes in the Parched Elastohydrodynamic Regime

    NASA Technical Reports Server (NTRS)

    Jones, William R., Jr.; Toddy, Thomas J.; Predmore, Roamer; Shogrin, Bradley; Herrera-Fierro Pilar

    1997-01-01

    A parched elastohydrodynamic rig was used to determine relative bearing lifetimes as a function of cleaning procedures in a series of accelerated tests. Two ODC-free cleaning procedures (super critical CO2 and ultraviolet-ozone) were compared to a CFC-113 control. Bearings (52100 steel) were run in the counter rotating mode (equivalent to 4600 rpm) with a full complement (i.e. no retainer) and a single charge of lubricant (Krytox 143 AC). Test conditions included: an air atmosphere, 445N load, approx. 1.0 GPa mean Hertz stress. There was approximately a 50% reduction in life with bearings cleaned with UV/ozone and a 70% reduction in life with SFE CO2 when compared to the Freon control. Possible reasons for these decreases in lifetimes are presented.

  5. The Effect of ODC-Free Cleaning Techniques on Bearing Lifetimes in the Parched Elastohydrodynamic Regime

    NASA Technical Reports Server (NTRS)

    Jones, William R., Jr.; Toddy, Thomas J.; Predmore, Roamer; Shogrin, Bradley; Herrera-Fierro, Pilar

    1996-01-01

    A parched elastohydrodynamic rig was used to determine relative bearing lifetimes as a function of cleaning procedures in a series of accelerated tests. Two ODC-free cleaning procedures (super critical CO2 and ultraviolet-ozone) were compared to a CFC-113 control. Bearings (52100 steel) were run in the counter rotating mode (equivalent to 4600 rpm) with a full complement (i.e. no retainer) and a single charge of lubricant (Krytox 143 AC). Test conditions included: an air atmosphere, 445 N load, approx. 1.0 GPa mean Hertz stress. There was approximately a 50% reduction in life with bearings cleaned with UV/ozone and a 70% reduction in life with SFE CO2 when compared to the Freon control. Possible reasons for these decreases in lifetimes are presented.

  6. Transient Plume Model Testing Using LADEE Spacecraft Attitude Control System Operations

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

    Woronowicz, M. S.

    2011-05-20

    The Lunar Atmosphere Dust Environment Explorer (LADEE) spacecraft is being designed for a mission featuring low altitude orbits of the Moon to take relevant ambient measurements before that environment becomes altered by future exploration activities. Instruments include a neutral mass spectrometer capable of measuring ambient species density levels below 100 molecules/cm{sup 3}. Coincidentally, with a favorable combination of spacecraft orientations, it is also possible to measure plume gases from LADEE attitude control system thruster operations as they are reflected from the daytime lunar surface and subsequently intercepted by the spacecraft as it orbits overhead. Under such circumstances, it may bemore » possible to test a variety of properties and assumptions associated with various transient plume models or to infer certain aspects regarding lunar surface properties.« less

  7. Transient Plume Model Testing Using LADEE Spacecraft Attitude Control System Operations

    NASA Technical Reports Server (NTRS)

    Woronowicz, M. S.

    2010-01-01

    The Lunar Atmosphere Dust Environment Explorer (LADEE) spacecraft is being designed for a mission featuring low altitude orbits of the Moon to take relevant ambient measurements before that environment becomes altered by future exploration activities. Instruments include a neutral mass spectrometer capable of measuring ambient species density levels below 100 molecules/cu cm. Coincidentally, with a favorable combination of spacecraft orientations, it is also possible to measure plume gases from LADEE attitude control system thruster operations as they are reflected from the daytime lunar surface and subsequently intercepted by the spacecraft as it orbits overhead. Under such circumstances, it may be possible to test a variety of properties and assumptions associated with various transient plume models or to infer certain aspects regarding lunar surface properties.

  8. Atmospheric effects on inlets for supersonic cruise aircraft

    NASA Technical Reports Server (NTRS)

    Cole, G. L.

    1977-01-01

    Mixed-compression inlet dynamic behavior in the vicinity of unstart, was simulated and analyzed to investigate time response of an inlet's normal shock to independent disturbances in ambient temperature and pressure and relative velocity (longitudinal gust), with and without inlet controls active. The results indicate that atmospheric disturbances may be more important than internal disturbances in setting inlet controls requirements because they are usually not anticipated and because normal shock response to rapid atmospheric disturbances is not attenuated by the inlet, as it is for engine induced disturbances. However, before inlet control requirements can be fully assessed, more statistics on extreme atmospheric disturbances are needed.

  9. Testing command and control of the satellites in formation flight

    NASA Astrophysics Data System (ADS)

    Gheorghe, Popan; Gheorghe, Gh. Ion; Gabriel, Todoran

    2013-10-01

    The topics covered in the paper are mechatronic systems for determining the distance between the satellites and the design of the displacement system on air cushion table for satellites testing. INCDMTM has the capability to approach the collaboration within European Programms (ESA) of human exploration of outer space through mechatronic systems and accessories for telescopes, mechatronics systems used by the launchers, sensors and mechatronic systems for the robotic exploration programs of atmosphere and Mars. This research has a strong development component of industrial competitiveness many of the results of space research have direct applicability in industrial fabrication.

  10. Controlling for anthropogenically induced atmospheric variation in stable carbon isotope studies

    USGS Publications Warehouse

    Long, E.S.; Sweitzer, R.A.; Diefenbach, D.R.; Ben-David, M.

    2005-01-01

    Increased use of stable isotope analysis to examine food-web dynamics, migration, transfer of nutrients, and behavior will likely result in expansion of stable isotope studies investigating human-induced global changes. Recent elevation of atmospheric CO2 concentration, related primarily to fossil fuel combustion, has reduced atmospheric CO2 ??13C (13C/12C), and this change in isotopic baseline has, in turn, reduced plant and animal tissue ??13C of terrestrial and aquatic organisms. Such depletion in CO2 ??13C and its effects on tissue ??13C may introduce bias into ??13C investigations, and if this variation is not controlled, may confound interpretation of results obtained from tissue samples collected over a temporal span. To control for this source of variation, we used a high-precision record of atmospheric CO2 ??13C from ice cores and direct atmospheric measurements to model modern change in CO2 ??13C. From this model, we estimated a correction factor that controls for atmospheric change; this correction reduces bias associated with changes in atmospheric isotopic baseline and facilitates comparison of tissue ??13C collected over multiple years. To exemplify the importance of accounting for atmospheric CO2 ??13C depletion, we applied the correction to a dataset of collagen ??13C obtained from mountain lion (Puma concolor) bone samples collected in California between 1893 and 1995. Before correction, in three of four ecoregions collagen ??13C decreased significantly concurrent with depletion of atmospheric CO2 ??13C (n ??? 32, P ??? 0.01). Application of the correction to collagen ??13C data removed trends from regions demonstrating significant declines, and measurement error associated with the correction did not add substantial variation to adjusted estimates. Controlling for long-term atmospheric variation and correcting tissue samples for changes in isotopic baseline facilitate analysis of samples that span a large temporal range. ?? Springer-Verlag 2005.

  11. Applications of AVHRR-Derived Ice Motions for the Arctic and Antarctic

    NASA Technical Reports Server (NTRS)

    Maslanik, James; Emery, William

    1998-01-01

    Characterization and diagnosis of sea ice/atmosphere/ocean interactions require a synthesis of observations and modeling to identify the key mechanisms controlling the ice/climate system. In this project, we combined product generation, observational analyses, and modeling to define and interpret variability in ice motion in conjunction with thermodynamic factors such as surface temperature and albedo. The goals of this work were twofold: (1) to develop and test procedures to produce an integrated set of polar products from remotely-sensed and supporting data; and (2) to apply these data to understand processes at work in controlling sea ice distribution.

  12. Transient Plume Model Testing Using LADEE Spacecraft Attitude Control System Operations

    NASA Technical Reports Server (NTRS)

    Woronowicz, Michael

    2011-01-01

    We have learned it is conceivable that the Neutral Mass Spectrometer on board the Lunarr Atmosphere Dust Environment Explorer (LADEE) could measure gases from surface-reflected Attitude Control System (ACS) thruster plume. At minimum altitude, the measurement would be maximized, and gravitational influence minimized ("short" time-of-flight (TOF) situation) Could use to verify aspects of thruster plume modeling Model the transient disturbance to NMS measurements due to ACS gases reflected from lunar surface Observe evolution of various model characteristics as measured by NMS Species magnitudes, TOF measurements, angular distribution, species separation effects

  13. Effect of dynamic controlled atmosphere monitored by respiratory quotient and 1-methylcyclopropene on the metabolism and quality of 'Galaxy' apple harvested at three maturity stages.

    PubMed

    Thewes, Fabio Rodrigo; Brackmann, Auri; Anese, Rogerio de Oliveira; Ludwig, Vagner; Schultz, Erani Eliseu; Dos Santos, Luana Ferreira; Wendt, Lucas Mallmann

    2017-05-01

    The objective of this study was to evaluate the interaction between controlled atmosphere (CA), CA+1-methylcyclopropene (1-MCP) and dynamic controlled atmosphere monitored by respiratory quotient (DCA-RQ) with three fruit maturity stages at harvest (early harvest date, optimal harvest date and late harvest date) on 'Galaxy' apple metabolism and quality after harvest and 9months storage plus 7days of shelf life at 20°C. Fruit stored under dynamic controlled atmosphere monitored by respiratory quotient 1.3 (DCA-RQ 1.3) showed lower ethylene production, respiration rate, mealiness and higher flesh firmness in comparison to CA stored fruit, but did not differ from those treated with 1-MCP. The dynamic controlled atmosphere monitored by respiratory quotient 1.5 (DCA-RQ 1.5) increased the acetaldehyde, ethanol and ethyl acetate concentration, regardless of the fruit maturity at harvest. The storage of 'Galaxy' apple under DCA-RQ 1.3 is efficient in keeping quality regardless of the maturity stage at harvest. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Contribution of the infrasound technology to characterize large scale atmospheric disturbances and impact on infrasound monitoring

    NASA Astrophysics Data System (ADS)

    Blanc, Elisabeth; Le Pichon, Alexis; Ceranna, Lars; Pilger, Christoph; Charlton Perez, Andrew; Smets, Pieter

    2016-04-01

    The International Monitoring System (IMS) developed for the verification of the Comprehensive nuclear-Test-Ban Treaty (CTBT) provides a unique global description of atmospheric disturbances generating infrasound such as extreme events (e.g. meteors, volcanoes, earthquakes, and severe weather) or human activity (e.g. explosions and supersonic airplanes). The analysis of the detected signals, recorded at global scales and over near 15 years at some stations, demonstrates that large-scale atmospheric disturbances strongly affect infrasound propagation. Their time scales vary from several tens of minutes to hours and days. Their effects are in average well resolved by the current model predictions; however, accurate spatial and temporal description is lacking in both weather and climate models. This study reviews recent results using the infrasound technology to characterize these large scale disturbances, including (i) wind fluctuations induced by gravity waves generating infrasound partial reflections and modifications of the infrasound waveguide, (ii) convection from thunderstorms and mountain waves generating gravity waves, (iii) stratospheric warming events which yield wind inversions in the stratosphere, (iv)planetary waves which control the global atmospheric circulation. Improved knowledge of these disturbances and assimilation in future models is an important objective of the ARISE (Atmospheric dynamics Research InfraStructure in Europe) project. This is essential in the context of the future verification of the CTBT as enhanced atmospheric models are necessary to assess the IMS network performance in higher resolution, reduce source location errors, and improve characterization methods.

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

    Jakob, Christian

    This report summarises an investigation into the relationship of tropical thunderstorms to the atmospheric conditions they are embedded in. The study is based on the use of radar observations at the Atmospheric Radiation Measurement site in Darwin run under the auspices of the DOE Atmospheric Systems Research program. Linking the larger scales of the atmosphere with the smaller scales of thunderstorms is crucial for the development of the representation of thunderstorms in weather and climate models, which is carried out by a process termed parametrisation. Through the analysis of radar and wind profiler observations the project made several fundamental discoveriesmore » about tropical storms and quantified the relationship of the occurrence and intensity of these storms to the large-scale atmosphere. We were able to show that the rainfall averaged over an area the size of a typical climate model grid-box is largely controlled by the number of storms in the area, and less so by the storm intensity. This allows us to completely rethink the way we represent such storms in climate models. We also found that storms occur in three distinct categories based on their depth and that the transition between these categories is strongly related to the larger scale dynamical features of the atmosphere more so than its thermodynamic state. Finally, we used our observational findings to test and refine a new approach to cumulus parametrisation which relies on the stochastic modelling of the area covered by different convective cloud types.« less

  16. Comparing the Degree of Land-Atmosphere Interaction in Four Atmospheric General Circulation Models

    NASA Technical Reports Server (NTRS)

    Koster, Randal D.; Dirmeyer, Paul A.; Hahmann, Andrea N.; Ijpelaar, Ruben; Tyahla, Lori; Cox, Peter; Suarez, Max J.; Houser, Paul R. (Technical Monitor)

    2001-01-01

    Land-atmosphere feedback, by which (for example) precipitation-induced moisture anomalies at the land surface affect the overlying atmosphere and thereby the subsequent generation of precipitation, has been examined and quantified with many atmospheric general circulation models (AGCMs). Generally missing from such studies, however, is an indication of the extent to which the simulated feedback strength is model dependent. Four modeling groups have recently performed a highly controlled numerical experiment that allows an objective inter-model comparison of land-atmosphere feedback strength. The experiment essentially consists of an ensemble of simulations in which each member simulation artificially maintains the same time series of surface prognostic variables. Differences in atmospheric behavior between the ensemble members then indicates the degree to which the state of the land surface controls atmospheric processes in that model. A comparison of the four sets of experimental results shows that feedback strength does indeed vary significantly between the AGCMs.

  17. Soil Moisture Dynamics in the Shallow Subsurface Near the Land/Atmospheric Interface- Challenges and New Research Approaches (Invited)

    NASA Astrophysics Data System (ADS)

    Illangasekare, T. H.; Smits, K. M.; Trautz, A.; Rice, A. K.; Cihan, A.; Davarzani, H.

    2013-12-01

    SSoil moisture processes in the subsurface/near-land-surface, play a crucial role in the hydrologic cycle and global water budget. This zone is subject to both natural and human induced disturbances, resulting in continually changing soil structure and hydraulic, thermal, and mechanical properties. Understanding of the dynamics of soil moisture distribution in this zone is of interest in various applications in hydrology such as land-atmospheric interaction, soil evaporation and evapotranspiration, as well as emerging problems on assessing the risk of leakage of sequestrated CO2 from deep geologic formations to the shallow subsurface, and potential leakage of methane to the atmosphere in shale gas development that contributes to global warming. Shallow subsurface soil moisture is highly influenced by diurnal temperature variations, evaporation/condensation, precipitation and liquid water and water vapor flow, all of which are strongly coupled. Modeling studies, have shown that soil moisture in this zone is highly sensitive to the heat and mass flux boundary conditions at the land surface. Hence, approximation of these boundary conditions without properly incorporating complex feedback between the land and the atmospheric boundary layer are expected to result in significant errors. Even though considerable knowledge exists on how soil moisture changes in response to the flux and energy boundary conditions, emerging problems involving land atmospheric interactions require the quantification of soil moisture variability at higher spatial and temporal resolutions than what is needed in traditional applications in soil physics and vadose zone hydrology. These factors lead to many modeling challenges, primarily of which is the issue of up-scaling. It is our contention that knowledge that will contribute to both improving our understanding of the fundamental processes and practical problem solutions cannot be obtained using only field data. Basic to this limitation is the inability to make field measurements at very fine scales at high temporal resolutions. Also, as the natural boundary conditions at the land/atmospheric interface are not controllable in the field, even in pilot scale studies, the developed theories and models cannot be validated for a diversity of conditions that could be expected. As an alternative, we propose an innovative testing approach that couples a low velocity boundary layer climate wind tunnel to intermediate scale porous media tanks. Intermediate scale testing using soil tanks packed to represent different heterogeneous test configurations provides an attractive and cost effective alternative to investigate a class of problems involving the shallow unsaturated zone. In this talk, we will present examples of studies we have conducted in a hierarchy of test systems, including the intermediate scale. The advantages and limitations of testing at this scale are discussed using these examples. The features and capabilities of newly developed test systems are presented with the goal of exploring opportunities to use them to study some of the challenging multi-scale problems in the near surface unsaturated zone.

  18. Automated test-site radiometer for vicarious calibration

    NASA Astrophysics Data System (ADS)

    Li, Xin; Yin, Ya-peng; Liu, En-chao; Zhang, Yan-na; Xun, Li-na; Wei, Wei; Zhang, Zhi-peng; Qiu, Gang-gang; Zhang, Quan; Zheng, Xiao-bing

    2014-11-01

    In order to realize unmanned vicarious calibration, Automated Test-site Radiometer (ATR) was developed for surface reflectance measurements. ATR samples the spectrum from 400nm-1600 nm with 8 interference filters coupled with silicon and InGaAs detectors. The field of view each channel is 10 ° with parallel optical axis. One SWIR channel lies in the center and the other seven VNIR channels are on the circle of 4.8cm diameters which guarantee each channel to view nearly the same section of ground. The optical head as a whole is temperature controlled utilizing a TE cooler for greater stability and lower noise. ATR is powered by a solar panel and transmit its data through a BDS (China's BeiDou Navigation Satellite System) terminator for long-term measurements without personnel in site. ATR deployed in Dunhuang test site with ground field about 30-cm-diameter area for multi-spectral reflectance measurements. Other instruments at the site include a Cimel sunphotometer and a diffuser-to-globe irradiance meter for atmosphere observations. The methodology for band-averaged reflectance retrieval and hyperspectral reflectance fitting process are described. Then the hyperspectral reflectance and atmospheric parameters are put into 6s code to predict TOA radiance which compare with MODIS radiance.

  19. Airborne Detection and Dynamic Modeling of Carbon Dioxide and Methane Plumes

    NASA Astrophysics Data System (ADS)

    Jacob, Jamey; Mitchell, Taylor; Whyte, Seabrook

    2015-11-01

    To facilitate safe storage of greenhouse gases such as CO2 and CH4, airborne monitoring is investigated. Conventional soil gas monitoring has difficulty in distinguishing gas flux signals from leakage with those associated with meteorologically driven changes. A low-cost, lightweight sensor system has been developed and implemented onboard a small unmanned aircraft that measures gas concentration and is combined with other atmospheric diagnostics, including thermodynamic data and velocity from hot-wire and multi-hole probes. To characterize the system behavior and verify its effectiveness, field tests have been conducted over controlled rangeland burns and over simulated leaks. In the former case, since fire produces carbon dioxide over a large area, this was an opportunity to test in an environment that while only vaguely similar to a carbon sequestration leak source, also exhibits interesting plume behavior. In the simulated field tests, compressed gas tanks are used to mimic leaks and generate gaseous plumes. Since the sensor response time is a function of vehicle airspeed, dynamic calibration models are required to determine accurate location of gas concentration in (x , y , z , t) . Results are compared with simulations using combined flight and atmospheric dynamic models. Supported by Department of Energy Award DE-FE0012173.

  20. Rain gauge calibration and testing

    NASA Technical Reports Server (NTRS)

    Wilkerson, John

    1994-01-01

    Prior to the Tropical Oceans Global Atmosphere-Coupled Ocean Atmosphere Response Experiment (TOGA-COARE), 42 Model 100 series optical gauges were tested in the rain simulator facility at Wallops Island before shipment to the field. Baseline measurements at several rain rates were made simultaneously with collector cans, tipping bucket, and a precision weighing gauge and held for post-COARE evaluation with a repeat set of measurements that were to be recorded after the instruments were returned. This was done as a means of detecting any calibration changes that might have occurred while deployed. Although it was known that the artificial rain in the simulator did not contain the required exponential distribution for accurate optical rain gauge rate measurements, use of the facility was necessary because it was the only means available for taking controlled observations with instruments that were received, tested, and shipped out in groups over a period of months. At that point, it was believed that these measurements would be adequately precise for detecting performance changes over time. However, analysis of the data by STI now indicates that this may not be true. Further study of the data will be undertaken to resolve this.

  1. Huygens Atmospheric Structure Instrument (HASI) test by a stratospheric balloon experiment

    NASA Astrophysics Data System (ADS)

    Fulchignoni, M.; Gaborit, V.; Aboudam, A.; Angrilli, F.; Antonello, M.; Bastianello, S.; Bettanini, C.; Bianchini, G.; Colombatti, G.; Ferri, F.; Lion Stoppato, P.

    2002-09-01

    We developped a series of balloon experiments parachuting a 1:1 scale mock up of the Huygens probe from an altitude larger than 30 km in order to simulate at planetary scale the final part of the descent of the probe in the Titan atmosphere. The Earth atmosphere represents a natural laboratory where most of the physical parameters meet quite well the bulk condition of Titan's environment, with the exception of temperature. A first balloon experiment has been carried out in June 2001 and the results have been reported at the last DPS (V. Gaborit et al., BAAS 33, 38.03) The mock up of the probe descending in the Titan atmosphere for the Huygens Cassini Mission has been successfully launched with stratospheric balloon from Italian Space Agency Base "Luigi Broglio" in Sicily and recovered on May 30th 2002. The probe has been lifted at 32 km altitude and then released to perform a 45 minutes descent decelerated by parachute, to simulate Huygens mission at Titan. Preliminary aerodynamics study of the probe has focused on the achievement of a descent velocity profile and a spin rate profile, satisfying the Huygens mission to Titan requirements. The descent velocity and spin rate have been calculated by solving a system of ODE describing the translational and rotational motion of the probe trough the earth atmosphere during parachute aided descent Results of these calculations have driven the choice of an appropriate angle of attack of the blades in the bottom of the probe and ballast weight during flight. The probe is hosting spares of HASI sensors, housekeeping sensors and other dedicated sensors, Beagle II UV Sensors and Huygens SSP Tilt Sensor, for a total of 77 acquired sensor channels, sampled during ascent, drift and descent phase. Main goals are i) to verify sensor performance and perform a realistic functional test in dynamical and environmental conditions similar to those during the descent in Titan atmosphere; ii) to investigate impact at ground to check the impact detection sequence of HASI accelerometer and HASI in the surface phase; iii) to test the codes developped to perfor the descent trajectory reconstruction of the Huygens probe in the Titan atmosphere. An integrated data acquisition and instrument control system has been developed, based on PC architecture and soft-real-time application. Sensors channels have been sampled at the nominal HASI data rates, with a max rate of 1 kHz. Software has been developed for data acquisition, onboard storage and telemetry transmission satisfying all requests for real-time monitoring, diagnostic and redundancy.

  2. Characterization of Xe-133 global atmospheric background: Implications for the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty

    NASA Astrophysics Data System (ADS)

    Achim, Pascal; Generoso, Sylvia; Morin, Mireille; Gross, Philippe; Le Petit, Gilbert; Moulin, Christophe

    2016-05-01

    Monitoring atmospheric concentrations of radioxenons is relevant to provide evidence of atmospheric or underground nuclear weapon tests. However, when the design of the International Monitoring Network (IMS) of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) was set up, the impact of industrial releases was not perceived. It is now well known that industrial radioxenon signature can interfere with that of nuclear tests. Therefore, there is a crucial need to characterize atmospheric distributions of radioxenons from industrial sources—the so-called atmospheric background—in the frame of the CTBT. Two years of Xe-133 atmospheric background have been simulated using 2013 and 2014 meteorological data together with the most comprehensive emission inventory of radiopharmaceutical facilities and nuclear power plants to date. Annual average simulated activity concentrations vary from 0.01 mBq/m3 up to above 5 mBq/m3 nearby major sources. Average measured and simulated concentrations agree on most of the IMS stations, which indicates that the main sources during the time frame are properly captured. Xe-133 atmospheric background simulated at IMS stations turn out to be a complex combination of sources. Stations most impacted are in Europe and North America and can potentially detect Xe-133 every day. Predicted occurrences of detections of atmospheric Xe-133 show seasonal variations, more accentuated in the Northern Hemisphere, where the maximum occurs in winter. To our knowledge, this study presents the first global maps of Xe-133 atmospheric background from industrial sources based on two years of simulation and is a first attempt to analyze its composition in terms of origin at IMS stations.

  3. Trace Contaminant Testing with the Orion Atmosphere Revitalization Technology

    NASA Technical Reports Server (NTRS)

    Button, Amy Lin; Sweterlitsch, Jeffrey; Broerman, Craig

    2009-01-01

    Every spacecraft atmosphere contains trace contaminants resulting from offgassing by cabin materials and human passengers. An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Orion Atmosphere Revitalization System (ARS). Part of the risk mitigation effort for this new technology is the study of how atmospheric trace contaminants will affect and be affected by the technology. One particular area of concern is ammonia, which, in addition to the normal spacecraft sources, can also be off-gassed by the amine-based sorbent. In the first half of 2009, tests were performed with typical cabin atmosphere levels of five of the most common trace gases, most of which had not yet been tested with this technology. A subscale sample of the sorbent was exposed to each of the chemicals mixed into a stream of moist, CO2-laden air, and the CO2 adsorption capacity of the sorbent was compared before and after the exposure. After these typical-concentration chemicals were proven to have negligible effect on the subscale sample, tests proceeded on a full-scale test article in a sealed chamber with a suite of eleven contaminants. To isolate the effects of various test rig components, several extended-duration tests were run: without injection or scrubbing, with injection and without scrubbing, with injection and scrubbing by both the test article and dedicated trace contaminant filters, and with injection and scrubbing by only the test article. The high-level results of both the subscale and full-scale tests are examined in this paper.

  4. The Effects of a Concept Map-Based Information Display in an Electronic Portfolio System on Information Processing and Retention in a Fifth-Grade Science Class Covering the Earth's Atmosphere

    ERIC Educational Resources Information Center

    Kim, Paul; Olaciregui, Claudia

    2008-01-01

    An electronic portfolio system, designed to serve as a resource-based learning space, was tested in a fifth-grade science class. The control-group students accessed a traditional folder-based information display in the system and the experimental-group students accessed a concept map-based information display to review a science portfolio. The…

  5. The X-15 airplane - Lessons learned

    NASA Technical Reports Server (NTRS)

    Dana, William H.

    1993-01-01

    The X-15 rocket research airplane flew to an altitude of 354,000 ft and reached Mach 6.70. In almost 200 flights, this airplane was used to gather aerodynamic-heating, structural loads, stability and control, and atmospheric-reentry data. This paper describes the origins, design, and operation of the X-15 airplane. In addition, lessons learned from the X-15 airplane that are applicable to designing and testing the National Aero-Space Plane are discussed.

  6. Re-entry simulation chamber for thermo-mechanical characterisation of space materials

    NASA Astrophysics Data System (ADS)

    Liedtke, Volker

    2003-09-01

    During re-entry, materials and components are subject to very high thermal and mechanical loads. Any failure may cause loss of mission. Therefore, materials and components have to be tested under most rigid conditions to verify the suitability of the material and to verify the design of the components. The Re-Entry Simulation Chamber (RESiC) at ARC Seibersdorf research (ARCS) allows simulating the high thermal loads as well as complex mechanical load profiles that may occur during a re-entry; additionally, the influence of chemical reactions of materials with gaseous components of the atmosphere can be studied. The high vacuum chamber (better than 1×10-6 mbar) has a diameter of 650 mm and allows a sample height of 500 mm, or 1000 mm with extension flange. The gas dosing system is designed to emulate the increasing atmospheric pressure during the re-entry trajectory of a vehicle. Heating is performed by a 30 kW induction generator that allows a sufficiently rapid heating of larger components; electrically conductive materials such as metals or carbon fibre reinforced ceramics are directly heated, while for electrical insulators, susceptor plates or tubes will be employed. The uniaxial servo-hydraulic testing machine has a maximum load of 70 kN, either static or with a frequency of up to 70 Hz, with any given load profile (sinus, rectangular, triangular, ...). Strain measurements will be done by non-contacting laser speckle system for maximum flexibility and minimum instrumentation time effort (currently under application testing), or by strain gauges. All relevant process parameters are controlled and recorded by microcomputer. The highly sophisticated control software allows a convenient and reliable multi-channel data acquisition, e.g. temperatures at various positions of the test piece, pressure, loads, strains, and any other test data according to customer specifications; the data format is suitable for any further data processing. During the set-up and operation testing, the device has successfully been employed for thermal shock testing, thermal cycling and gas cycling tests, thermomechanical tests and combinations thereof, e.g. sintering or hot-pressing. During the current final test series, the device will be completed, further optimised and shall be fully operational in summer 2003.

  7. Test evaluation of potential heat shield contamination of an Outer Planet Probe's atmospheric sampling system

    NASA Technical Reports Server (NTRS)

    Kessler, W. C.; Woeller, F. H.; Wilkins, M. E.

    1975-01-01

    An Outer Planets Probe which retains the charred heatshield during atmospheric descent must deploy a sampling tube through the heatshield to extract atmospheric samples for analysis. Once the sampling tube is deployed, the atmospheric samples ingested must be free of contaminant gases generated by the heatshield. Outgassing products such as methane and water vapor are present in planetary atmospheres and hence, ingestion of such species would result in gas analyzer measurement uncertainties. This paper evaluates the potential for, and design impact of, the extracted atmospheric samples being contaminated by heatshield outgassing products. Flight trajectory data for Jupiter, Saturn and Uranus entries are analyzed to define the conditions resulting in the greatest potential for outgassing products being ingested into the probe's sampling system. An experimental program is defined and described which simulates the key flow field features for a planetary flight in a ground-based test facility. The primary parameters varied in the test include: sampling tube length, injectant mass flow rate and angle of attack. Measured contaminant levels predict the critical sampling tube length for contamination avoidance. Thus, the study demonstrates the compatibility of a retained heatshield concept and high quality atmospheric trace species measurements.

  8. A one-dimensional interactive soil-atmosphere model for testing formulations of surface hydrology

    NASA Technical Reports Server (NTRS)

    Koster, Randal D.; Eagleson, Peter S.

    1990-01-01

    A model representing a soil-atmosphere column in a GCM is developed for off-line testing of GCM soil hydrology parameterizations. Repeating three representative GCM sensitivity experiments with this one-dimensional model demonstrates that, to first order, the model reproduces a GCM's sensitivity to imposed changes in parameterization and therefore captures the essential physics of the GCM. The experiments also show that by allowing feedback between the soil and atmosphere, the model improves on off-line tests that rely on prescribed precipitation, radiation, and other surface forcing.

  9. BIOGENIC HYDROCARBONS IN THE ATMOSPHERIC BOUNDARY LAYER: A REVIEW

    EPA Science Inventory

    Nonmethane hydrocarbons are ubiquitous trace atmospheric constituents yet they control the oxidation capacity of the atmosphere. Both anthropogenic and biogenic processes contribute to the release of hydrocarbons to the atmosphere. In this manuscript, the state of the science ...

  10. An Earth-Based Equivalent Low Stretch Apparatus to Assess Material Flammability for Microgravity & Extraterrestrial Fire-Safety Applications

    NASA Technical Reports Server (NTRS)

    Olson, S. L.; Beeson, H.; Haas, J.

    2001-01-01

    One of the performance goals for NASA's enterprise of Human Exploration and Development of Space (HEDS) is to develop methods, data bases, and validating tests for material flammability characterization, hazard reduction, and fire detection/suppression strategies for spacecraft and extraterrestrial habitats. This work addresses these needs by applying the fundamental knowledge gained from low stretch experiments to the development of a normal gravity low stretch material flammability test method. The concept of the apparatus being developed uses the low stretch geometry to simulate the conditions of the extraterrestrial environment through proper scaling of the sample dimensions to reduce the buoyant stretch in normal gravity. The apparatus uses controlled forced-air flow to augment the low stretch to levels which simulate Lunar or Martian gravity levels. In addition, the effect of imposed radiant heat flux on material flammability can be studied with the cone heater. After breadboard testing, the apparatus will be integrated into NASA's White Sands Test Facility's Atmosphere-Controlled Cone Calorimeter for evaluation as a new materials screening test method.

  11. Continuous time-resolved regional methane leak detection with on-line background estimation using a novel combination of dual frequency comb laser spectroscopy and atmospheric inversions

    NASA Astrophysics Data System (ADS)

    Alden, C. B.; Coburn, S.; Wright, R.; Baumann, E.; Cossel, K.; Sweeney, C.; Ghosh, S.; Newbury, N.; Prasad, K.; Coddington, I.; Rieker, G. B.

    2017-12-01

    Advances in natural gas extraction technology have led to increased US production and transport activity, and as a consequence, an increased need for monitoring of methane leaks. Current leak detection methods provide time snapshots, and not continuous, time-varying estimates of emissions. Most approaches also require specific atmospheric conditions, operators, or the use of a tracer gas, requiring site access. Given known intermittency in fugitive methane emissions, continuous monitoring is a critical need for emissions mitigation. We present a novel leak detection method that employs dual frequency comb spectrometry to offer continuous, autonomous, leak detection and quantification over square-km scale areas. The spectrometer is situated in a field of natural gas pads, and a series of retroreflectors around the field direct light back to a detector. The laser light spans 1620-1680 nm with 0.002 nm line spacing, measuring thousands of individual absorption features from multiple species. The result is high-stability trace gas (here CH4, CO2, and H2O) measurements over long (1 km+) open paths through the atmosphere. Measurements are used in an atmospheric inversion to estimate the time variability of emissions at each location of interest. Importantly, the measurement framework and inversion solve explicitly for background concentrations, which vary rapidly in fields of active oil and gas production. We present the results of controlled-leak field tests in rural Colorado. We demonstrate the ability to locate and size a leak located 1 km away from the spectrometer and varying in strength from 1.5 to 7.7 g/min, resulting in mean atmospheric enhancements of 20 ppb. The inversion correctly identifies when the leak turned on and off over a 24-hour period, and determines the mean leak strength to within 10% of the true controlled rate. We further demonstrate the ability of the system to correctly locate and size the start and end of simultaneous 2.7 to 4.8 g/min leaks from 2 sources in a field of 5 potential leak locations. Finally, we present the results of leak-detection tests in active oil and gas fields in the Denver Julesburg Basin, where background methane is complex.

  12. Efficacy of oxygen-supplying capacity of Azolla in a controlled life support system

    NASA Astrophysics Data System (ADS)

    Chen, Min; Deng, Sufang; Yang, Youquan; Huang, Yibing; Liu, Chongchu

    2012-02-01

    Azolla shows high growth and propagation rates, strong photosynthetic O2-releasing ability and high nutritional value. It is suitable as a salad vegetable and can be cultured on a multi-layered wet bed. Hence, it possesses potential as a fresh vegetable, and to release O2 and absorb CO2 in a Controlled Ecological Life Support System in space. In this study, we investigated the O2-providing characteristics of Azolla in a closed chamber under manned, controlled conditions to lay a foundation for use of Azolla as a biological component in ground simulation experiments for space applications. A closed test chamber, representing a Controlled Ecological Life Support System including an Azolla wet-culture device, was built to measure the changes in atmospheric O2 and CO2 concentrations inside the chamber in the presence of coexisting Azolla, fish and men. The amount of O2 consumed by fish was 0.0805-0.0831 L kg-1 h-1 and the level of CO2 emission was 0.0705-0.0736 L kg-1 h-1; O2 consumption by the two trial volunteers was 19.71 L h-1 and the volume of respiration-released CO2 was 18.90 L h-1. Under 7000-8000 Lx artificial light and Azolla wet-culture conditions, human and fish respiration and Azolla photosynthesis were complementary, thus the atmospheric O2 and CO2 concentrations inside chamber were maintained in equilibrium. The increase in atmospheric CO2 concentration in the closed chamber enhanced the net photosynthesis efficiency of the Azolla colony. This study showed that Azolla has strong photosynthetic O2-releasing ability, which equilibrates the O2 and CO2 concentrations inside the chamber in favor of human survival and verifies the potential of Azolla for space applications.

  13. Study on O2-supplying characteristics of Azolla in Controlled Ecological Life Support System

    NASA Astrophysics Data System (ADS)

    Chen, Min; Deng, Sufang; Yang, Youquang; Huang, Yibing; Liu, Zhongzhu

    Azolla has high growth and propagation rate, strong photosynthetic O2-releasing ability and rich nutrient value. It is able to be used as salad-type vegetable, and can also be cultured on wet bed in multi-layer condition. Hence, it possesses a potential functioning as providing O2, fresh vegetable and absorbing CO2 for Controlled Ecological Life Support System in space. In this study, we try to make clear the O2-providing characteristics of Azolla in controlled close chamber under manned condition in order to lay a foundation for Azolla as a biological component in the next ground simulated experiment and space application. A closed test cham-ber of Controlled Ecological Life Support System and Azolla wet-culturing devices were built to measure the changes of atmospheric O2-CO2 concentration inside chamber under "Azolla-fish -men" coexisting condition. The results showed that, the amount of O2 consumption is 80.49 83.07 ml/h per kilogram fish, the amount of CO2 emissions is 70.49 73.56 ml/(kg • h); O2 consumption of trial volunteers is 19.71 L/h, the volume of respiration release CO2 18.90 L/h .Artificial light intensity of Azolla wet culture under 70009000 Lx, people respiration and Azolla photosynthesis complemented each other, the atmospheric O2-CO2 concentration inside chamber maintained equilibration. Elevated atmospheric CO2 concentrations in close chamber have obvious effects on enhancing Azolla net photosynthesis efficiency. This shows that Azolla has strong photosynthetic O2-releasing ability, which equilibrates the O2-CO2 concentration inside chamber in favor of human survival, and then verifies the prospect of Azolla in space application.

  14. Bioregenerative system

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The design course is an eight semester credit multi-disciplinary engineering design course taught primarily to Engineering Science, Aerospace, Electrical and Mechanical Engineering seniors. This year the course project involved the design of the three interrelated loops: atmospheric, liquid nutrient and solid waste management, associated with growing higher plants to support man during long-term space missions. The project is complementary to the NASA Kennedy Space Center Controlled Environmental Life Support System (CELSS) project. The first semester the class worked on a preliminary design for a complete system. This effort included means for monitoring and control of composition, temperature, flow rate, etc., for the atmosphere and liquid nutrient solution; disease and contaminant monitoring and control; plant mechanical support, propagation and harvesting; solid and liquid waste recycling; and system maintenance and refurbishing. The project has significant biological, mechanical, electrical and Al/Robotics aspects. The second semester a small number of subsystems or components, identified as important and interesting during the first semester, were selected for detail design, fabrication, and testing. The class was supported by close cooperation with The Kennedy Space Center and by two teaching assistants. The availability of a dedicated, well equipped project room greatly enhanced the communication and team spirit of the class.

  15. Supersonic aerodynamic characteristics of some reentry concepts for angles of attack up to 90 deg

    NASA Technical Reports Server (NTRS)

    Spearman, M. L.

    1985-01-01

    Past studies of reentry vehicles tested to high angles of attack (up to 90 deg) in the Mach number range from 2 to 4.8 have provided some fundamental insights into the aerodynamic characteristics of such vehicles. Two basic planforms are considered in this paper: highly swept deltas, and circular. The delta concepts include variations in cross section (and thus volume) and in camber distribution. The effectiveness of various types of aerodynamic control devices is also included. The purpose of the paper is to examine the characteristics of the vehicles with a view toward the potential usefulness of such concepts in a flight regime that would include reentry from space into the atmosphere, followed by a transition to sustained atmospheric flight.

  16. Harvesting model uncertainty for the simulation of interannual variability

    NASA Astrophysics Data System (ADS)

    Misra, Vasubandhu

    2009-08-01

    An innovative modeling strategy is introduced to account for uncertainty in the convective parameterization (CP) scheme of a coupled ocean-atmosphere model. The methodology involves calling the CP scheme several times at every given time step of the model integration to pick the most probable convective state. Each call of the CP scheme is unique in that one of its critical parameter values (which is unobserved but required by the scheme) is chosen randomly over a given range. This methodology is tested with the relaxed Arakawa-Schubert CP scheme in the Center for Ocean-Land-Atmosphere Studies (COLA) coupled general circulation model (CGCM). Relative to the control COLA CGCM, this methodology shows improvement in the El Niño-Southern Oscillation simulation and the Indian summer monsoon precipitation variability.

  17. Further Investigations of High Temperature Knitted Spring Tubes for Advanced Control Surface Seal Applications

    NASA Technical Reports Server (NTRS)

    Taylor, Shawn C.; DeMange, Jeffrey J.; Dunlap, Patrick H., Jr.; Steinetz, Bruce M.

    2006-01-01

    Knitted metallic spring tubes are the structural backbones that provide resiliency in control surface seals for use on current and future reusable space launch vehicles. Control surface seals fill the space between movable control surfaces such as body flaps, rudders and elevons, and the static body structures to which they are attached. These seals must remain in continuous contact with opposing surfaces to prevent the ingestion of damaging hot gases encountered during atmospheric re-entry. The Inconel X-750 (Special Metals Corporation) spring tube utilized in the baseline control surface seal shows significant resiliency loss when compressed at temperatures as low as 1200 F. High temperature compression testing and microstructural analysis show that creep is the dominant deformation mechanism leading to permanent set and resiliency loss in tested spring tube samples. Additional evaluation using a structured design of experiments approach shows that spring tube performance, primarily high temperature resiliency, can be enhanced through material substitution of Rene 41 (Allvac) alloy (for the baseline Inconel X-750 material) when coupled with specialized thermal processing.

  18. Active Vertical Tail Buffeting Alleviation on an F/A-18 Model in a Wind Tunnel

    NASA Technical Reports Server (NTRS)

    Moses, Robert W.

    1999-01-01

    A 1/6-scale F-18 wind-tunnel model was tested in the Transonic Dynamics Tunnel at the NASA Langley Research Center as part of the Actively Controlled Response Of Buffet-Affected Tails (ACROBAT) program to assess the use of active controls in reducing vertical tail buffeting. The starboard vertical tail was equipped with an active rudder and other aerodynamic devices, and the port vertical tail was equipped with piezoelectric actuators. The tunnel conditions were atmospheric air at a dynamic pressure of 14 psf. By using single-input-single-output control laws at gains well below the physical limits of the control effectors, the power spectral density of the root strains at the frequency of the first bending mode of the vertical tail was reduced by as much as 60 percent up to angles of attack of 37 degrees. Root mean square (RMS) values of root strain were reduced by as much as 19 percent. Stability margins indicate that a constant gain setting in the control law may be used throughout the range of angle of attack tested.

  19. Pressure-Application Device for Testing Pressure Sensors

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A portable pressure-application device has been designed and built for use in testing and calibrating piezoelectric pressure transducers in the field. The device generates pressure pulses of known amplitude. A pressure pulse (in contradistinction to a steady pressure) is needed because in the presence of a steady pressure, the electrical output of a piezoelectric pressure transducer decays rapidly with time. The device includes a stainless- steel compressed-air-storage cylinder of 500 cu cm volume. A manual hand pump with check valves and a pressure gauge are located at one end of the cylinder. A three-way solenoid valve that controls the release of pressurized air is located at the other end of the cylinder. Power for the device is provided by a 3.7-V cordless-telephone battery. The valve is controlled by means of a pushbutton switch, which activates a 5 V to +/-15 V DC-to-DC converter that powers the solenoid. The outlet of the solenoid valve is connected to the pressure transducer to be tested. Before the solenoid is energized, the transducer to be tested is at atmospheric pressure. When the solenoid is actuated by the push button, pressurized air from inside the cylinder is applied to the transducer. Once the pushbutton is released, the cylinder pressure is removed from the transducer and the pressurized air applied to the transducer is vented, bringing the transducer back to atmospheric pressure. Before this device was used for actual calibration, its accuracy was checked with a NIST (National Institute of Standards and Technology) traceable calibrator and commercially calibrated pressure transducers. This work was done by Wanda Solano of Stennis Space Center and Greg Richardson of Lockheed Martin Corp.

  20. Biological UV dosimeters in simulated space irradiation conditions

    NASA Astrophysics Data System (ADS)

    Rontó, G.; Bérces, A.; Fekete, A.; Kovács, G.; Lammer, H.

    For the measurement of the harmful biological effect of solar UV radiation bacteriophage T7 and polycrystalline uracil dosimeters were used. For terrestrial dosimetric purposes bacteriophage T7 has been applied in solution, while uracil in the form of thin layers. For space irradiation dosimetry the uracil, phage T7-DNA and bacteriophage T7 thin layer samples were prepared in vacuum tightly closed sandwich forms covered either by calciumfluoride or quartz windows. The experimental conditions tested correspond to the conditions planned in the EXPOSE facility: the samples were surrounded by nitrogen atmosphere at various humidities, their vacuum stability was tested in the vacuum chamber of the Institute of Space Research,, Graz. All kinds of the thin film samples have been stored in an atmosphere containing Nitrogen and Hidrogen, in quality control no change in the structure of them has been found. To attenuate the high extraterrestrial irradiance neutral filters of 0.5 and 1.0 optical densities have been tested. Irradiation of the samples has been performed with various UV sources: solar simulator, low pressure Mercury lamp, Deuterium lamp. Dose-effect functions have been determined using for the evaluation spectrophotometry in the characteristic UV range, HPLC of photoproducts, PCR of two different primer sequences of phage T7-DNA. Photoproduct formation kinetics was followed by the saturation level of uracil thin layer. Attenuation ability of the neutral filters was controlled with low pressure Mercury lamp by the exposure necessary for saturation of uracil dosimeters. A three and tenfold increase in the exposure was found respectively, while the influence of spectral composition of the irradiation source was tested using Deuterium lamp supplied with Ca F2 and quartz filters respectively. A doubling of the irradiance was necessary for the saturation of uracil with quartz filter.

  1. Easterly and westerly wind events in the equatorial Pacific ocean and their oceanic response

    NASA Astrophysics Data System (ADS)

    Puy, martin; Lengaigne, matthieu; Vialard, jerome; Guilyardi, eric

    2014-05-01

    Intraseasonal wind variability is known to influence the onset and evolution of the El Niño Southern Oscillation (ENSO), in particular through the occurrence of Westerly Wind Events (WWEs) in the western Equatorial Pacific. For predictability purposes, it is important to identify the large scale atmospheric controls of the occurrences of those WWEs. We hence carefully assess the link between equatorial WWEs and large-scale atmospheric waves. We find that WWEs preferably occur during convectively active phases associated to equatorial atmospheric Rossby waves (74% against 15% if the distribution was random) and to the MJO (60% against 15%). We also find that WWEs that occur in relation with those atmospheric waves tend to be stronger. The results also show that WWEs that occur in relation with the MJO tend to be longer than others, and tend to have a larger impact on SST, both on the eastern edge of the warm pool and in the eastern Pacific. We further show that the central and eastern equatorial Pacific is home to frequent easterly wind events (EWEs). These EWEs are further shown to be influenced by atmospheric Rossby waves and the MJO, but to a lesser extent than WWEs. We will discuss the potential influence of EWEs on the ENSO cycle, and propose a modeling strategy to test the influence of these EWEs / WWEs on the ENSO evolution.

  2. Load responsive multilayer insulation performance testing

    NASA Astrophysics Data System (ADS)

    Dye, S.; Kopelove, A.; Mills, G. L.

    2014-01-01

    Cryogenic insulation designed to operate at various pressures from one atmosphere to vacuum, with high thermal performance and light weight, is needed for cryogenically fueled space launch vehicles and aircraft. Multilayer insulation (MLI) performs well in a high vacuum, but the required vacuum shell for use in the atmosphere is heavy. Spray-on foam insulation (SOFI) is often used in these systems because of its light weight, but can have a higher heat flux than desired. We report on the continued development of Load Responsive Multilayer Insulation (LRMLI), an advanced thermal insulation system that uses dynamic beam discrete spacers that provide high thermal performance both in atmosphere and vacuum. LRMLI consists of layers of thermal radiation barriers separated and supported by micromolded polymer spacers. The spacers have low thermal conductance, and self-support a thin, lightweight vacuum shell that provides internal high vacuum in the insulation. The dynamic load responsive spacers compress to support the external load of a vacuum shell in one atmosphere, and decompress under reduced atmospheric pressure for lower heat leak. Structural load testing was performed on the spacers with various configurations. LRMLI was installed on a 400 liter tank and boil off testing with liquid nitrogen performed at various chamber pressures from one atmosphere to high vacuum. Testing was also performed with an MLI blanket on the outside of the LRMLI.

  3. Gain Scheduling for the Orion Launch Abort Vehicle Controller

    NASA Technical Reports Server (NTRS)

    McNamara, Sara J.; Restrepo, Carolina I.; Madsen, Jennifer M.; Medina, Edgar A.; Proud, Ryan W.; Whitley, Ryan J.

    2011-01-01

    One of NASAs challenges for the Orion vehicle is the control system design for the Launch Abort Vehicle (LAV), which is required to abort safely at any time during the atmospheric ascent portion of ight. The focus of this paper is the gain design and scheduling process for a controller that covers the wide range of vehicle configurations and flight conditions experienced during the full envelope of potential abort trajectories from the pad to exo-atmospheric flight. Several factors are taken into account in the automation process for tuning the gains including the abort effectors, the environmental changes and the autopilot modes. Gain scheduling is accomplished using a linear quadratic regulator (LQR) approach for the decoupled, simplified linear model throughout the operational envelope in time, altitude and Mach number. The derived gains are then implemented into the full linear model for controller requirement validation. Finally, the gains are tested and evaluated in a non-linear simulation using the vehicles ight software to ensure performance requirements are met. An overview of the LAV controller design and a description of the linear plant models are presented. Examples of the most significant challenges with the automation of the gain tuning process are then discussed. In conclusion, the paper will consider the lessons learned through out the process, especially in regards to automation, and examine the usefulness of the gain scheduling tool and process developed as applicable to non-Orion vehicles.

  4. 28 CFR 79.31 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... first participated onsite in an atmospheric detonation of a nuclear device. (d) Period of atmospheric...), (e), (f), (g), and (h), and in § 79.21, apply to this subpart. (b) Atmospheric detonation of a... decontamination of ships involved in Operation Crossroads; the period of atmospheric nuclear testing for the...

  5. UV absorption control of thin film growth

    DOEpatents

    Biefeld, Robert M.; Hebner, Gregory A.; Killeen, Kevin P.; Zuhoski, Steven P.

    1991-01-01

    A system for monitoring and controlling the rate of growth of thin films in an atmosphere of reactant gases measures the UV absorbance of the atmosphere and calculates the partial pressure of the gases. The flow of reactant gases is controlled in response to the partial pressure.

  6. Engineering of pulsed laser deposited calcium phosphate biomaterials in controlled atmospheres

    NASA Astrophysics Data System (ADS)

    Drukteinis, Saulius E.

    Synthetic calcium phosphates (CAP) such as hydroxyapatite (HA) have been used as regenerative bone graft materials and also as thin films to improve the integration of biomedical implant devices within skeletal tissue. Pulsed laser deposition (PLD) can deposit crystalline HA with significant adhesion on titanium biomaterials. However, there are PLD processing constraints due to the complex physical and chemical interactions occurring simultaneously during PLD, which influence ablation plume formation and development. In this investigation PLD CAP films were engineered with a focus on novel decoupling of partial pressure of H2O (g) ( PH2O ) from total background pressure, in combination with substrate heat treatment and laser energy density control. Characterization of these films was performed with X-ray Diffraction, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Fourier Transform Infrared Spectroscopy, and Optical Profilometry. In vitro cellular adhesion testing was also performed using osteoblast (MC3T3) cell lines to evaluate adhesion of bone-forming cells on processed PLD CAP samples. Preferred a-axis orientation films were deposited in H2O (g) saturated atmospheres with reduced laser fluence (< 4 J/cm2). Crystalline HA/tetracalcium phosphate (TTCP) films were deposited in H2O ( g)-deficient atmospheres with higher laser fluence (> 3 J/cm 2). Varied PH2O resulted in control of biphasic HA/TTCP composition with increasing TTCP at lower PH2O . These were dense continuous films composed of micron-scale particles. Cellular adhesion assays did not demonstrate a significant difference between osteoblast adhesion density on HA films compared with biphasic HA/TTCP films. Room temperature PLD at varied PH2O combined with furnace heat treatment resulted in controlled variation in surface amplitude parameters including surface roughness (S a), root mean square (Sq), peak to valley height (St), and ten-point height ( Sz). These discontinuous films were composed of nano-scale particles and resulted in significant osteoblast adhesion compared to control samples or to PLD CAP films deposited on heated substrates. Surface amplitude parameters (Sa, Sq, St, and Sz) correlated with osteoblast adhesion. This new approach of control over H2O ( g) operating atmospheres enabled the deposition of unique PLD CAP films with potential use as thin films for biomedical implants or as regenerative bone graft materials. Keywords: hydroxyapatite, pulsed laser deposition, biomaterials.

  7. The Dependence of Cloud-SST Feedback on Circulation Regime and Timescale

    NASA Astrophysics Data System (ADS)

    Middlemas, E.; Clement, A. C.; Medeiros, B.

    2017-12-01

    Studies suggest cloud radiative feedback amplifies internal variability of Pacific sea surface temperature (SST) on interannual-and-longer timescales, though only a few modeling studies have tested the quantitative importance of this feedback (Bellomo et al. 2014b, Brown et al. 2016, Radel et al. 2016 Burgman et al. 2017). We prescribe clouds from a previous control run in the radiation module in Community Atmospheric Model (CAM5-slab), a method called "cloud-locking". By comparing this run to a control run, in which cloud radiative forcing can feedback on the climate system, we isolate the effect of cloud radiative forcing on SST variability. Cloud-locking prevents clouds from radiatively interacting with atmospheric circulation, water vapor, and SST, while maintaining a similar mean state to the control. On all timescales, cloud radiative forcing's influence on SST variance is modulated by the circulation regime. Cloud radiative forcing amplifies SST variance in subsiding regimes and dampens SST variance in convecting regimes. In this particular model, a tug of war between latent heat flux and cloud radiative forcing determines the variance of SST, and the winner depends on the timescale. On decadal-and-longer timescales, cloud radiative forcing plays a relatively larger role than on interannual-and-shorter timescales, while latent heat flux plays a smaller role. On longer timescales, the absence of cloud radiative feedback changes SST variance in a zonally asymmetric pattern in the Pacific Ocean that resembles an IPO-like pattern. We also present an analysis of cloud feedback's role on Pacific SST variability among preindustrial control CMIP5 models to test the model robustness of our results. Our results suggest that circulation plays a crucial role in cloud-SST feedbacks across the globe and cloud radiative feedbacks cannot be ignored when studying SST variability on decadal-and-longer timescales.

  8. Generic aerocapture atmospheric entry study, volume 1

    NASA Technical Reports Server (NTRS)

    1980-01-01

    An atmospheric entry study to fine a generic aerocapture vehicle capable of missions to Mars, Saturn, and Uranus is reported. A single external geometry was developed through atmospheric entry simulations. Aerocapture is a system design concept which uses an aerodynamically controlled atmospheric entry to provide the necessary velocity depletion to capture payloads into planetary orbit. Design concepts are presented which provide the control accuracy required while giving thermal protection for the mission payload. The system design concepts consist of the following elements: (1) an extendable biconic aerodynamic configuration with lift to drag ratio between 1.0 and 2.0; (2) roll control system concepts to control aerodynamic lift and disturbance torques; (3) aeroshell design concepts capable of meeting dynamic pressure loads during aerocapture; and (4) entry thermal protection system design concepts to meet thermodynamic loads during aerocapture.

  9. Hyperbaric Oxygen Therapy and Oxygen Compatibility of Skin and Wound Care Products

    PubMed Central

    Bernatchez, Stéphanie F.; Tucker, Joseph; Chiffoleau, Gwenael

    2017-01-01

    Objective: Use test methods to assess the oxygen compatibility of various wound care products. Approach: There are currently no standard test methods specifically for evaluating the oxygen compatibility and safety of materials under hyperbaric oxygen (HBO) conditions. However, tests such as the oxygen index (OI), oxygen exposure (OE), and autogenous ignition temperature (AIT) can provide useful information. Results: The OI test measures the minimum oxygen concentration that will support candle-like burning, and it was used to test 44 materials. All but two exhibited an OI equal to or greater (safer) than a control material commonly used in HBO. The OE test exposes each material to an oxygen-enriched atmosphere (>99.5% oxygen) to monitor temperature and pressure for an extended duration. The results of the OE testing indicated that none of the 44 articles tested with this method self-ignited within the 60°C, 3 atm pressurized oxygen atmosphere. The AIT test exposes materials to a rapid ramp up in temperature in HBO conditions at 3 atm until ignition occurs. Ten wound care materials and seven materials usually avoided in HBO chambers were tested. The AIT ranged from 138°C to 384°C for wound care products and from 146°C to 420°C for the other materials. Innovation: This work provides useful data and recommendations to help develop a new standard approach for evaluating the HBO compatibility of wound care products to ensure safety for patients and clinicians. Conclusion: The development of an additional test to measure the risk of electrostatic discharge of materials in HBO conditions is needed. PMID:29098113

  10. Parachute Testing for the NASA X-38 Crew Return Vehicle

    NASA Technical Reports Server (NTRS)

    Stein, Jenny M.

    2005-01-01

    NASA's X-38 program was an in-house technology demonstration program to develop a Crew Return Vehicle (CRV) for the International Space Station capable of returning seven crewmembers to Earth when the Space Shuttle was not present at the station. The program, managed out of NASA's Johnson Space Center, was started in 1995 and was cancelled in 2003. Eight flights with a prototype atmospheric vehicle were successfully flown at Edwards Air Force Base, demonstrating the feasibility of a parachute landing system for spacecraft. The intensive testing conducted by the program included testing of large ram-air parafoils. The flight test techniques, instrumentation, and simulation models developed during the parachute test program culminated in the successful demonstration of a guided parafoil system to land a 25,000 Ib spacecraft. The test program utilized parafoils of sizes ranging from 750 to 7500 p. The guidance, navigation, and control system (GN&C) consisted of winches, laser or radar altimeter, global positioning system (GPS), magnetic compass, barometric altimeter, flight computer, and modems for uplink commands and downlink data. The winches were used to steer the parafoil and to perform the dynamic flare maneuver for a soft landing. The laser or radar altimeter was used to initiate the flare. In the event of a GPS failure, the software navigated by dead reckoning using the compass and barometric altimeter data. The GN&C test beds included platforms dropped from cargo aircraft, atmospheric vehicles released from a 8-52, and a Buckeye powered parachute. This paper will describe the test program and significant results.

  11. P-REx: The Piston Reconstruction Experiment for infrared interferometry

    NASA Astrophysics Data System (ADS)

    Widmann, Felix; Pott, Jörg-Uwe; Velasco, Sergio

    2018-03-01

    For sensitive infrared interferometry, it is crucial to control the differential piston evolution between the used telescopes. This is classically done by the use of a fringe tracker. In this work, we develop a new method to reconstruct the temporal piston variation from the atmosphere, by using real-time data from adaptive optics (AO) wavefront sensing: the Piston Reconstruction Experiment (P-REx). In order to understand the principle performance of the system in a realistic multilayer atmosphere, it is first extensively tested in simulations. The gained insights are then used to apply P-REx to real data, in order to demonstrate the benefit of using P-REx as an auxiliary system in a real interferometer. All tests show positive results, which encourages further research and eventually a real implementation. Especially, the tests on on-sky data showed that the atmosphere is, under decent observing conditions, sufficiently well structured and stable, in order to apply P-REx. It was possible to conveniently reconstruct the piston evolution in two-thirds of the data sets from good observing conditions (r0 ˜ 30 cm). The main conclusion is that applying the piston reconstruction in a real system would reduce the piston variation from around 10 μm down to 1-2 μm over time-scales of up to two seconds. This suggests an application for mid-infrared interferometry, for example for MATISSE at the very large telescope interferometer or the large binocular telescope interferometer. P-REx therefore provides the possibility to improve interferometric measurements without the need for more complex AO systems than already in regular use at 8-m-class telescopes.

  12. Coronas-F Orbit Monitoring and Re-Entry Prediction

    NASA Technical Reports Server (NTRS)

    Ivanov, N. M.; Kolyuka, Yu. F.; Afanasieva, T. I.; Gridchina, T. A.

    2007-01-01

    Russian scientific satellite CORONAS-F was launched on July, 31, 2001. The object was inserted in near-circular orbit with the inclination 82.5deg and a mean altitude approx. 520 km. Due to the upper atmosphere drag CORONAS-F was permanently descended and as a result on December, 6, 2005 it has finished the earth-orbital flight, having lifetime in space approx. 4.5 years. The satellite structural features and its flight attitude control led to the significant variations of its ballistic coefficient during the flight. It was a cause of some specific difficulties in the fulfillment of the ballistic and navigation support of this space vehicle flight. Besides the main mission objective CORONAS-F also has been selected by the Inter-Agency Space Debris Coordination Committee (IADC) as a target object for the next regular international re-entry test campaign on a program of surveillance and re-entry prediction for the hazard space objects within their de-orbiting phases. Spacecraft (S/C) CORONAS-F kept its working state right up to the end of the flight - down to the atmosphere entry. This fact enabled to realization of the additional research experiments, concerning with an estimation of the atmospheric density within the low earth orbits (LEO) of the artificial satellites, and made possible to continue track the S/C during final phase of its flight by means of Russian regular command & tracking system, used for it control. Thus there appeared a unique possibility of using for tracking S/C at its de-orbiting phase not only passive radar facilities, belonging to the space surveillance systems and traditionally used for support of the IADC re-entry test campaigns, but also more precise active trajectory radio-tracking facilities from the ground control complex (GCC) applied for this object. Under the corresponding decision of the Russian side such capability of additional high-precise tracking control of the CORONAS-F flight in this period of time has been implemented. The organizing of the CORONAS-F ballistic and navigational support (BNS) and solving its main tasks (such as S/C orbit determination (OD) and its motion prediction and connected with them) both for regular mission stage and for additional flight program were realized by the group of specialists from the Mission Control Center (MCC). MCC was also assigned as a principal organization from the Russian side for participation in the 7th IADC re-entry test campaign on CORONAS-F. The CORONAS-F flight features and space environments circumstances during its flight as well as a methodology and technology of spacecraft ballistic and navigational support are given below. The BNS results for different phases of S/C flight, including the results of its re-entry predictions, obtained during the realization of the 7th IADC test campaign are submitted. The accuracy of space vehicle re-entry prediction and its dependence on various factors are analyzed in more details.

  13. Effect of anthropogenic activities on atmospheric 14C content and radiocarbon chronologies of the future.

    NASA Astrophysics Data System (ADS)

    Hajdas, Irka

    2017-04-01

    Radiocarbon (14C) is a naturally produced radioactive isotope of carbon (T1/2=5700 yrs), which is continuously produced in the atmosphere. This occur in a reaction of thermal neutrons, which are secondary particles, products of cosmic rays reactions with the atmosphere, with nitrogen that is commonly present in the atmosphere. Until the mid 19th century the natural concentration showed temporal variability around the mean value (14C / 12C ratio =1.8 x 10-12). However anthropogenic activity created 2 types effects that are changing the 14C concentration of the atmosphere. Industrial revolution triggered adding 14C free (old) carbon that originates from the burning of fossil fuels (Suess effect). This in the late 19th century and early 20th century atmosphere was becoming older. The nuclear tests in the 1950ties caused additional production of radiocarbon atoms (artificial). The effect has been almost double of the natural production and created an excess 14C activity in the atmosphere and in terrestrial carbon bearing materials. The bomb produced 14C has been identified soon after the tests started but the peak (ca. 100% above the normal levels) reached its maximum in 1963 in the northern Hemisphere where most of the tests took place. In the southern Hemisphere the bomb peak reached lower values (ca. 80 % of normal level) and was delayed by ca. 2 years. After the ban on nuclear tests the atmospheric 14C content began to decrease mainly due to the uptake by the ocean but also due to the above mentioned addition old carbon. Continuous monitoring of the atmospheric 14C ratio during the years that followed the nuclear tests, provide basis for environmental studies. Applications range from studies of ocean circulation, CO2 uptake, carbon storage in soils and peat, root turn over time to the medical, forensic and detection of forgeries. However, the so called ' 14C bomb peak' nearly disappeared due to the combined effect of ocean uptake of CO2 and an input to the atmosphere of the '14C-free' carbon dioxide. This paper will discuss effects that the ongoing change in atmospheric 14C has on geochronologies of the most recent deposits and future anthropogenic records.

  14. Climate and atmosphere simulator for experiments on ecological systems in changing environments.

    PubMed

    Verdier, Bruno; Jouanneau, Isabelle; Simonnet, Benoit; Rabin, Christian; Van Dooren, Tom J M; Delpierre, Nicolas; Clobert, Jean; Abbadie, Luc; Ferrière, Régis; Le Galliard, Jean-François

    2014-01-01

    Grand challenges in global change research and environmental science raise the need for replicated experiments on ecosystems subjected to controlled changes in multiple environmental factors. We designed and developed the Ecolab as a variable climate and atmosphere simulator for multifactor experimentation on natural or artificial ecosystems. The Ecolab integrates atmosphere conditioning technology optimized for accuracy and reliability. The centerpiece is a highly contained, 13-m(3) chamber to host communities of aquatic and terrestrial species and control climate (temperature, humidity, rainfall, irradiance) and atmosphere conditions (O2 and CO2 concentrations). Temperature in the atmosphere and in the water or soil column can be controlled independently of each other. All climatic and atmospheric variables can be programmed to follow dynamical trajectories and simulate gradual as well as step changes. We demonstrate the Ecolab's capacity to simulate a broad range of atmospheric and climatic conditions, their diurnal and seasonal variations, and to support the growth of a model terrestrial plant in two contrasting climate scenarios. The adaptability of the Ecolab design makes it possible to study interactions between variable climate-atmosphere factors and biotic disturbances. Developed as an open-access, multichamber platform, this equipment is available to the international scientific community for exploring interactions and feedbacks between ecological and climate systems.

  15. Overview of NASA's Environmental Control and Life Support Systems

    NASA Technical Reports Server (NTRS)

    Roman, Monserrate

    2009-01-01

    This viewgraph presentation reviews NASA's Environmental Control and Life Support Systems (ECLSS) on the International Space Station. A look inside of the International Space Station detailing ECLSS processes of controlling atmospheric pressure, conditioning the atmosphere, responding to emergency conditions, controlling internal carbon dioxide and contaminants and providing water are described. A detailed description of ISS Regenerative Environmental Control and Life Support System is also presented.

  16. Further Testing of an Amine-based Pressure-Swing System for Carbon Dioxide and Humidity Control

    NASA Technical Reports Server (NTRS)

    Lin, Amy; Smith, Frederick; Sweterlitsch, Jeffrey; Nalette, Tim A.; Papale, William

    2008-01-01

    In a crewed spacecraft environment, atmospheric carbon dioxide (CO2) and moisture control are crucial. Hamilton Sundstrand has developed a stable and efficient amine-based CO2 and water vapor sorbent, SA9T, that is well suited for use in a spacecraft environment. The sorbent is efficiently packaged in pressure-swing regenerable beds that are thermally linked to improve removal efficiency and minimize vehicle thermal loads. Flows are all controlled with a single spool valve. This technology has been baselined for the new Orion spacecraft. However, more data was needed on the operational characteristics of the package in a simulated spacecraft environment. A unit was therefore tested with simulated metabolic loads in a closed chamber at Johnson Space Center during the last third of 2006. Those test results were reported in a 2007 ICES paper. A second test article was incorporated for a third phase of testing, and that test article was modified to allow pressurized gas purge regeneration on the launch pad in addition to the standard vacuum regeneration in space. Metabolic rates and chamber volumes were also adjusted to reflect current programmatic standards. The third phase of tests was performed during the spring and summer of 2007. Tests were run with a range of operating conditions, varying: cycle time, vacuum pressure (or purge gas flow rate), air flow rate, and crew activity levels. Results of this testing are presented and potential flight operational strategies discussed.

  17. Monitoring and control of atmosphere in a closed environment

    NASA Technical Reports Server (NTRS)

    Humphries, R.; Perry, J.

    1991-01-01

    Applications requiring new technologies for atmosphere monitoring and control in the closed environment and their principal functions aboard the Space Station Freedom are described. Oxygen loop closure, involving the conversion of carbon dioxide to oxygen; carbon dioxide reduction and removal; and monitoring of atmospheric contamination are discussed. The Trace Contaminant Monitor, the Major Constituent Analyzer, the Carbon Dioxide Monitor, and the Particulate Counter Monitor are discussed.

  18. 78 FR 77104 - Coastal Nonpoint Pollution Control Program: Intent To Find That Oregon Has Failed To Submit an...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-20

    ... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration ENVIRONMENTAL PROTECTION AGENCY Coastal Nonpoint Pollution Control Program: Intent To Find That Oregon Has Failed To Submit an Approvable Coastal Nonpoint Pollution Control Program AGENCY: National Oceanic and Atmospheric Administration...

  19. Research on propagation properties of controllable hollow flat-topped beams in turbulent atmosphere based on ABCD matrix

    NASA Astrophysics Data System (ADS)

    Liu, Huilong; Lü, Yanfei; Zhang, Jing; Xia, Jing; Pu, Xiaoyun; Dong, Yuan; Li, Shutao; Fu, Xihong; Zhang, Angfeng; Wang, Changjia; Tan, Yong; Zhang, Xihe

    2015-01-01

    This paper studies the propagation properties of controllable hollow flat-topped beams (CHFBs) in turbulent atmosphere based on ABCD matrix, sets up a propagation model and obtains an analytical expression for the propagation. With the help of numerical simulation, the propagation properties of CHFBs in different parameters are studied. Results indicate that in turbulent atmosphere, with the increase of propagation distance, the darkness of CHFBs gradually annihilate, and eventually evolve into Gaussian beams. Compared with the propagation properties in free space, the turbulent atmosphere enhances the diffraction effect of CHFBs and reduces the propagation distance for CHFBs to evolve into Gaussian beams. In strong turbulence atmospheric propagation, Airy disk phenomenon will disappear. The study on the propagation properties of CHFBs in turbulence atmosphere by using ABCD matrix is simple and convenient. This method can also be applied to study the propagation properties of other hollow laser beams in turbulent atmosphere.

  20. Deformation processes in forging ceramics

    NASA Technical Reports Server (NTRS)

    Cannon, R. M.; Rhodes, W. H.

    1973-01-01

    The deformation processes involved in the forging of refractory ceramic oxides were investigated. A combination of mechanical testing and forging was utilized to investigate both the flow and fracture processes involved. Deformation studies of very fine grain Al203 revealed an apparent transition in behavior, characterized by a shift in the strain rate sensitivity from 0.5 at low stresses to near unity at higher stresses. The behavior is indicative of a shift in control between two dependent mechanisms, one of which is indicated to be cation limited diffusional creep with significant boundary enhancement. The possible contributions of slip, indicated by crystallographic texture, interface control of the diffusional creep and inhomogeneous boundary sliding are also discussed. Additional experiments indicated an independence of deformation behavior on MgO doping and retained hot pressing impurities, at least for ultrafine grained material, and also an independence of test atmosphere.

  1. Discovering Parameters for Ancient Mars Atmospheric Profiles by Modeling Volcanic Eruptions

    NASA Astrophysics Data System (ADS)

    Meyer, A.; Clarke, A. B.; Van Eaton, A. R.; Mastin, L. G.

    2017-12-01

    Evidence of explosive volcanic deposits on Mars motivates questions about the behavior of eruption plumes in the Ancient and current Martian atmosphere. Early modeling studies suggested that Martian plumes may rise significantly higher than their terrestrial equivalents (Wilson and Head, 1994, Rev. Geophys., 32, 221-263). We revisit the issue using a steady-state 1-D model of volcanic plumes (Plumeria: Mastin, 2014, JGR, doi:10.1002/2013JD020604) along with a range of reasonable temperature and pressures. The model assumes perfect coupling of particles with the gas phase in the plume, and Stokes number analysis indicates that this is a reasonable assumption for particle diameters less than 5 mm to 1 micron. Our estimates of Knudsen numbers support the continuum assumption. The tested atmospheric profiles include an estimate of current Martian atmosphere based on data from voyager mission (Seif, A., Kirk, D.B., (1977) Geophys., 82,4364-4378), a modern Earth-like atmosphere, and several other scenarios based on variable tropopause heights and near-surface atmospheric density estimates from the literature. We simulated plume heights using mass eruption rates (MER) ranging from 1 x 103 to 1 x 1010 kg s-1 to create a series of new theoretical MER-plume height scaling relationships that may be useful for considering plume injection heights, climate impacts, and global-scale ash dispersal patterns in Mars' recent and ancient geological past. Our results show that volcanic plumes in a modern Martian atmosphere may rise up to three times higher than those on Earth. We also find that the modern Mars atmosphere does not allow eruption columns to collapse, and thus does not allow for the formation of column-collapse pyroclastic density currents, a phenomenon thought to have occurred in Mars' past based on geological observations. The atmospheric density at the surface, and especially the height of the tropopause, affect the slope of the MER-plume height curve and control whether or not column-collapse is possible.

  2. Trace Contaminant Testing with the Orion Atmosphere Revitalization Technology

    NASA Technical Reports Server (NTRS)

    Button, Amy B.; Sweterlitsch, Jeffrey J.; Broerman, Craig D.; Campbell, Melissa L.

    2010-01-01

    Every spacecraft atmosphere contains trace contaminants resulting from offgassing by cabin materials and human passengers. An amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and baselined for the Orion Atmosphere Revitalization System (ARS). Part of the risk mitigation effort for this new technology is the study of how atmospheric trace contaminants will affect and be affected by the technology. One particular area of concern is ammonia, which, in addition to the normal spacecraft sources, can also be offgassed by the amine-based sorbent. In the spring of 2009, tests were performed at Johnson Space Center (JSC) with typical cabin atmosphere levels of five of the most common trace gases, most of which had not yet been tested with this technology. A subscale sample of the sorbent was exposed to each of the chemicals mixed into a stream of moist, CO2-laden air, and the CO2 adsorption capacity of the sorbent was compared before and after the exposure. After these typical-concentration chemicals were proven to have negligible effect on the subscale sample, tests proceeded on a full-scale test article in a sealed chamber with a suite of eleven contaminants. To isolate the effects of various test rig components, several extended-duration tests were run: without injection or scrubbing, with injection and without scrubbing, with injection of both contaminants and metabolic CO2 and water vapor loads and scrubbing by both the test article and dedicated trace contaminant filters, and with the same injections and scrubbing by only the test article. The high-level results of both the subscale and full-scale tests are examined in this paper.

  3. Thermal/vacuum vs. thermal atmospheric testing of space flight electronic assemblies

    NASA Technical Reports Server (NTRS)

    Gibbel, Mark

    1990-01-01

    For space flight hardware, the thermal vacuum environmental test is the best test of a system's flight worthiness. Substituting an atmospheric pressure thermal test for a thermal/vacuum test can effectively reduce piece part temperatures by 20 C or more, even for low power density designs. Similar reductions in test effectiveness can also result from improper assembly level T/V test boundary conditions. The net result of these changes may reduce the effective test temperatures to the point where there is zero or negative margin over the flight thermal environment.

  4. Aged particles derived from emissions of coal-fired power plants: The TERESA field results

    PubMed Central

    Kang, Choong-Min; Gupta, Tarun; Ruiz, Pablo A.; Wolfson, Jack M.; Ferguson, Stephen T.; Lawrence, Joy E.; Rohr, Annette C.; Godleski, John; Koutrakis, Petros

    2013-01-01

    The Toxicological Evaluation of Realistic Emissions Source Aerosols (TERESA) study was carried out at three US coal-fired power plants to investigate the potential toxicological effects of primary and photochemically aged (secondary) particles using in situ stack emissions. The exposure system designed successfully simulated chemical reactions that power plant emissions undergo in a plume during transport from the stack to receptor areas (e.g., urban areas). Test atmospheres developed for toxicological experiments included scenarios to simulate a sequence of atmospheric reactions that can occur in a plume: (1) primary emissions only; (2) H2SO4 aerosol from oxidation of SO2; (3) H2SO4 aerosol neutralized by gas-phase NH3; (4) neutralized H2SO4 with secondary organic aerosol (SOA) formed by the reaction of α-pinene with O3; and (5) three control scenarios excluding primary particles. The aged particle mass concentrations varied significantly from 43.8 to 257.1 μg/m3 with respect to scenario and power plant. The highest was found when oxidized aerosols were neutralized by gas-phase NH3 with added SOA. The mass concentration depended primarily on the ratio of SO2 to NOx (particularly NO) emissions, which was determined mainly by coal composition and emissions controls. Particulate sulfate (H2SO4 + neutralized sulfate) and organic carbon (OC) were major components of the aged particles with added SOA, whereas trace elements were present at very low concentrations. Physical and chemical properties of aged particles appear to be influenced by coal type, emissions controls and the particular atmospheric scenarios employed. PMID:20462390

  5. Flight mechanics applications for tethers in space: Cooperative Italian-US programs

    NASA Technical Reports Server (NTRS)

    Bevilacqua, Franco; Merlina, Pietro; Anderson, John L.

    1990-01-01

    Since the 1974 proposal by Giuseppe Colombo to fly a tethered subsatellite from the Shuttle Orbiter, the creative thinking of many scientists and engineers from Italy and U.S. has generated a broad range of potential tether applications in space. Many of these applications have promise for enabling innovative research and operational activities relating to flight mechanics in earth orbit and at suborbital altitudes. From a flight mechanics standpoint the most interesting of the currently proposed flight demonstrations are: the second Tethered Satellite System experiment which offers both the potential for aerothermodynamics and hypersonics research and for atmospheric science research; the Tethered Initiated Space Recovery System which would enable orbital deboost and recovery of a re-entry vehicle and waste removal from a space station; and the Tether Elevator/Crawler System which would provide a variable microgravity environment and space station center of mass management. The outer atmospheric and orbital flight mechanics characteristics of these proposed tether flight demonstrations are described. The second Tethered Satellite System mission will deploy the tethered satellite earthward and will bring it as low as 130 km from ground and thus into the transition region between the atmosphere (non-ionized) and the partially ionized ionosphere. The atmospheric flight mechanics of the tethered satellite is discussed and simulation results are presented. The Tether Initiated Space Recovery System experiment will demonstrate the ability of a simple tether system to deboost and recover a reentry vehicle. The main feature of this demonstration is the utilization of a Small Expendable Deployment System (SEDS) and the low-tension deployment assumed to separate the reentry vehicle from the Shuttle. This low-tension deployment maneuver is discussed and its criticalities are outlined. The Tether Elevator/Crawler System is a new space element able to move in a controlled way between the ends of a deployed tethered system. A Shuttle test of an Elevator model is planned to demonstrate the unique capability of this element as a microgravity facility and to test the transfer motion control. The basic dynamical features of the Elevator system are presented and a preliminary assessment of the Elevator-induced tether vibrations is discussed.

  6. Isolating Gas Sensor From Pressure And Temperature Effects

    NASA Technical Reports Server (NTRS)

    Sprinkle, Danny R.; Chen, Tony T. D.; Chaturvedi, Sushi K.

    1994-01-01

    Two-stage flow system enables oxygen sensor in system to measure oxygen content of low-pressure, possibly-high-temperature atmosphere in test environment while protecting sensor against possibly high temperature and fluctuations in pressure of atmosphere. Sensor for which flow system designed is zirconium oxide oxygen sensor sampling atmospheres in high-temperature wind tunnels. Also adapted to other gas-analysis instruments that must be isolated from pressure and temperature effects of test environments.

  7. Spatial variability in airborne bacterial communities across land-use types and their relationship to the bacterial communities of potential source environments

    PubMed Central

    Bowers, Robert M; McLetchie, Shawna; Knight, Rob; Fierer, Noah

    2011-01-01

    Although bacteria are ubiquitous in the near-surface atmosphere and they can have important effects on human health, airborne bacteria have received relatively little attention and their spatial dynamics remain poorly understood. Owing to differences in meteorological conditions and the potential sources of airborne bacteria, we would expect the atmosphere over different land-use types to harbor distinct bacterial communities. To test this hypothesis, we sampled the near-surface atmosphere above three distinct land-use types (agricultural fields, suburban areas and forests) across northern Colorado, USA, sampling five sites per land-use type. Microbial abundances were stable across land-use types, with ∼105–106 bacterial cells per m3 of air, but the concentrations of biological ice nuclei, determined using a droplet freezing assay, were on average two and eight times higher in samples from agricultural areas than in the other two land-use types. Likewise, the composition of the airborne bacterial communities, assessed via bar-coded pyrosequencing, was significantly related to land-use type and these differences were likely driven by shifts in the sources of bacteria to the atmosphere across the land-uses, not local meteorological conditions. A meta-analysis of previously published data shows that atmospheric bacterial communities differ from those in potential source environments (leaf surfaces and soils), and we demonstrate that we may be able to use this information to determine the relative inputs of bacteria from these source environments to the atmosphere. This work furthers our understanding of bacterial diversity in the atmosphere, the terrestrial controls on this diversity and potential approaches for source tracking of airborne bacteria. PMID:21048802

  8. Implications for high speed research: The relationship between sonic boom signature distortion and atmospheric turbulence

    NASA Technical Reports Server (NTRS)

    Sparrow, Victor W.; Gionfriddo, Thomas A.

    1994-01-01

    In this study there were two primary tasks. The first was to develop an algorithm for quantifying the distortion in a sonic boom. Such an algorithm should be somewhat automatic, with minimal human intervention. Once the algorithm was developed, it was used to test the hypothesis that the cause of a sonic boom distortion was due to atmospheric turbulence. This hypothesis testing was the second task. Using readily available sonic boom data, we statistically tested whether there was a correlation between the sonic boom distortion and the distance a boom traveled through atmospheric turbulence.

  9. IMPACT: Integrated Modeling of Perturbations in Atmospheres for Conjunction Tracking

    NASA Astrophysics Data System (ADS)

    Koller, J.; Brennan, S.; Godinez, H. C.; Higdon, D. M.; Klimenko, A.; Larsen, B.; Lawrence, E.; Linares, R.; McLaughlin, C. A.; Mehta, P. M.; Palmer, D.; Ridley, A. J.; Shoemaker, M.; Sutton, E.; Thompson, D.; Walker, A.; Wohlberg, B.

    2013-12-01

    Low-Earth orbiting satellites suffer from atmospheric drag due to thermospheric density which changes on the order of several magnitudes especially during space weather events. Solar flares, precipitating particles and ionospheric currents cause the upper atmosphere to heat up, redistribute, and cool again. These processes are intrinsically included in empirical models, e.g. MSIS and Jacchia-Bowman type models. However, sensitivity analysis has shown that atmospheric drag has the highest influence on satellite conjunction analysis and empirical model still do not adequately represent a desired accuracy. Space debris and collision avoidance have become an increasingly operational reality. It is paramount to accurately predict satellite orbits and include drag effect driven by space weather. The IMPACT project (Integrated Modeling of Perturbations in Atmospheres for Conjunction Tracking), funded with over $5 Million by the Los Alamos Laboratory Directed Research and Development office, has the goal to develop an integrated system of atmospheric drag modeling, orbit propagation, and conjunction analysis with detailed uncertainty quantification to address the space debris and collision avoidance problem. Now with over two years into the project, we have developed an integrated solution combining physics-based density modeling of the upper atmosphere between 120-700 km altitude, satellite drag forecasting for quiet and disturbed geomagnetic conditions, and conjunction analysis with non-Gaussian uncertainty quantification. We are employing several novel approaches including a unique observational sensor developed at Los Alamos; machine learning with a support-vector machine approach of the coupling between solar drivers of the upper atmosphere and satellite drag; rigorous data assimilative modeling using a physics-based approach instead of empirical modeling of the thermosphere; and a computed-tomography method for extracting temporal maps of thermospheric densities using ground based observations. The developed IMPACT framework is an open research framework enabling the exchange and testing of a variety of atmospheric density models, orbital propagators, drag coefficient models, ground based observations, etc. and study their effect on conjunctions and uncertainty predictions. The framework is based on a modern service-oriented architecture controlled by a web interface and providing 3D visualizations. The goal of this project is to revolutionize the ability to monitor and track space objects during highly disturbed space weather conditions, provide suitable forecasts for satellite drag conditions and conjunction analysis, and enable the exchange of models, codes, and data in an open research environment. We will present capabilities and results of the IMPACT framework including a demo of the control interface and visualizations.

  10. Evaluation program for secondary spacecraft cells: Initial evaluation tests of General Electric Company 6.0 ampere hour nickel-cadmium spacecraft cells with auxiliary electrodes for the atmospheric Explorer satellite C and D. [quality control testing

    NASA Technical Reports Server (NTRS)

    Harkness, J. D.

    1974-01-01

    The capacity of the cells ranged from 6.6 to 7.6 ampere hours during the three capacity tests. No voltage requirements or limits were exceeded during any portion of the test. All cells recovered to a voltage in excess of 1.193 volts during the 24-hour open-circuit portion of the internal short test. All the cells reached a pressure of 20 psia before reaching the voltage limit of 1.550 volts during the pressure versus capacity test. The average ampere/hours in and voltages at this pressure were 9.1 and 1.513, respectively. All cells exhibited pressure decay in the range of 1 to 5 psia during the last 30 minutes of the 1-hour open circuit stand. Average capacity out was 7.2 ampere/hours.

  11. Implementation of a GPS-RO data processing system for the KIAPS-LETKF data assimilation system

    NASA Astrophysics Data System (ADS)

    Kwon, H.; Kang, J.-S.; Jo, Y.; Kang, J. H.

    2014-11-01

    The Korea Institute of Atmospheric Prediction Systems (KIAPS) has been developing a new global numerical weather prediction model and an advanced data assimilation system. As part of the KIAPS Package for Observation Processing (KPOP) system for data assimilation, preprocessing and quality control modules for bending angle measurements of global positioning system radio occultation (GPS-RO) data have been implemented and examined. GPS-RO data processing system is composed of several steps for checking observation locations, missing values, physical values for Earth radius of curvature, and geoid undulation. An observation-minus-background check is implemented by use of a one-dimensional observational bending angle operator and tangent point drift is also considered in the quality control process. We have tested GPS-RO observations utilized by the Korean Meteorological Administration (KMA) within KPOP, based on both the KMA global model and the National Center for Atmospheric Research (NCAR) Community Atmosphere Model-Spectral Element (CAM-SE) as a model background. Background fields from the CAM-SE model are incorporated for the preparation of assimilation experiments with the KIAPS-LETKF data assimilation system, which has been successfully implemented to a cubed-sphere model with fully unstructured quadrilateral meshes. As a result of data processing, the bending angle departure statistics between observation and background shows significant improvement. Also, the first experiment in assimilating GPS-RO bending angle resulting from KPOP within KIAPS-LETKF shows encouraging results.

  12. A technology demonstrator for development of ultra-lightweight, large aperture, deployable telescope for space applications

    NASA Astrophysics Data System (ADS)

    Zuccaro Marchi, Alessandro; Gambicorti, Lisa; Simonetti, Francesca; Salinari, Piero; Lisi, Franco; Bursi, Alessandro; Olivier, Massimiliano; Gallieni, Daniele

    2017-11-01

    This work presents the latest results of new technological concepts for large aperture, lightweight telescopes using thin deployable active mirrors. The study is originally addressed to a spaceborne DIAL (Differential Absorption Lidar) at 935.5 nm for the measurement of water vapour profile in atmosphere, as an output of an ESA contract (whose preliminary results were presented at ICSO 2006). The high versatility of these concepts allows to exploit the presented technology for any project willing to consider large aperture, segmented lightweight telescopes. A possible scientific application is for Ultra High Energy Cosmic Rays detection through the fluorescence traces in atmosphere and diffused Cerenkov signals observation via a Schmidt-like spaceborne LEO telescope with large aperture, wide Field of View (FOV) and low f/#. A technology demonstrator has been manufactured and tested in order to investigate two project critical areas identified during the preliminary design: the performances of the long-stroke actuators used to implement the mirror active control and the mirror survivability to launch. In particular, this breadboard demonstrates at first that the mirror actuators are able to control with the adequate accuracy the surface shape and to recover a deployment error with their long stroke; secondly, the mirror survivability has been demonstrated using an electrostatic locking between mirror and backplane able to withstand without failure a vibration test representative of the launch environment.

  13. Seasonal 7Be and 137Cs activities in surface air before and after the Chernobyl event.

    PubMed

    Kulan, A

    2006-01-01

    Seasonal fluctuations of cosmogenic (7)Be (T(1/2)=53.4 days) and anthropogenic (137)Cs (T(1/2)=30 years) activities in surface air (aerosols) have been extracted from a long data record (1972-2000) at high latitude (56 degrees N-68 degrees N, Sweden). Normalization to weekly average values was used to control long-term trends so that cyclical trends could be investigated. Enhanced (7)Be activity was observed in spring and summer seasons and likely relates to the seasonal thinning of the tropopause. Variations in the (137)Cs activity record seem to reflect how the isotope was injected in the atmosphere (stratospheric from bomb tests and tropospheric from the Chernobyl accident) and subsequent transport mechanisms. Accordingly, until 1986, the surface air (137)Cs activity was strongly related to nuclear weapons test fallout and exhibits temporal fluctuations resembling the (7)Be. Conversely, since 1986 the Chernobyl-produced (137)Cs dominates the long-term record that shows annual cycles that are strongly controlled by atmospheric boundary layer conditions. Additionally, short-term data within the post-Chernobyl period suggest subtle intrusion of air masses rich in (137)Cs that may occur throughout the year, and differences resulting from spatial occurrence at these latitudes. This is an important observation that may have to do with year-to-year variation and calls for caution when interpreting short-term data records.

  14. Wake Numerical Simulation Based on the Park-Gauss Model and Considering Atmospheric Stability

    NASA Astrophysics Data System (ADS)

    Yang, Xiangsheng; Zhao, Ning; Tian, Linlin; Zhu, Jun

    2016-06-01

    In this paper, a new Park-Gauss model based on the assumption of the Park model and the Eddy-viscosity model is investigated to conduct the wake numerical simulation for solving a single wind turbine problem. The initial wake radius has been modified to improve the model’s numerical accuracy. Then the impact of the atmospheric stability based on the Park-Gauss model has been studied in the wake region. By the comparisons and the analyses of the test results, it turns out that the new Park-Gauss model could achieve better effects of the wind velocity simulation in the wake region. The wind velocity in the wake region recovers quickly under the unstable atmospheric condition provided the wind velocity is closest to the test result, and recovers slowly under stable atmospheric condition in case of the wind velocity is lower than the test result. Meanwhile, the wind velocity recovery falls in between the unstable and stable neutral atmospheric conditions.

  15. The development of a non-cryogenic nitrogen/oxygen supply system

    NASA Technical Reports Server (NTRS)

    Greenough, B. M.

    1972-01-01

    Development of the hydrazine/water electrolysis process in a manned spacecraft to provide metabolic oxygen and both oxygen and nitrogen for cabin leakage makeup was studied. Electrode development efforts were directed to stability, achieved with catalyst additives and improved processing techniques, and a higher hydrazine conversion efficiency, achieved by reducing catalyst loading on the cathodes. Extensive testing of the one-man breadboard N2/02 system provided complete characterization of cabin atmosphere control aspects. A detailed design of a prototype modular N2/02 unit was conducted. The contact heat exchanger which is an integral component of this design was fabricated and sucessfully design-verification tested.

  16. Passive Adsorption of Volatile Monoterpene in Pest Control: Aided by Proximity and Disrupted by Ozone.

    PubMed

    Mofikoya, Adedayo O; Kim, Tae Ho; Abd El-Raheem, Ahmed M; Blande, James D; Kivimäenpää, Minna; Holopainen, Jarmo K

    2017-11-08

    Plant volatiles mediate a range of interactions across and within trophic levels, including plant-plant interactions. Volatiles emitted by a plant may trigger physiological responses in neighboring plants or adhere to their surfaces, which, in turn, may affect the responses of the neighboring plant to herbivory. These volatiles are subject to chemical reactions during transport in air currents, especially in a polluted atmosphere. We conducted a field experiment to test for the adsorption of dispenser-released myrcene on the surfaces of cabbage plants and the effects of distance from the dispenser and elevated ozone levels (1.4× ambient) on the process. We also tested the effects of the same treatments on oviposition on cabbage plants by naturally occurring Plutella xylostella. Under low ambient ozone conditions of central Finland, there was evidence for the adsorption and re-release of myrcene by cabbage plants growing at a distance of 50 cm from myrcene dispensers. This effect was absent at elevated ozone levels. The number of eggs deposited by P. xylostella was generally lower in plots under elevated ozone compared to ambient control plots. Our results indicate that passive adsorption and re-release of a volatile monoterpene can occur in nature; however, this process is dependent upon the distance between emitter source and receiver plants as well as the concentration of atmospheric pollutants in the air. We conclude that, in the development of field-scale use of plant volatiles in modern pest control, the effects of distances and air pollution should be considered.

  17. A fuzzy logic-based model for noise control at industrial workplaces.

    PubMed

    Aluclu, I; Dalgic, A; Toprak, Z F

    2008-05-01

    Ergonomics is a broad science encompassing the wide variety of working conditions that can affect worker comfort and health, including factors such as lighting, noise, temperature, vibration, workstation design, tool design, machine design, etc. This paper describes noise-human response and a fuzzy logic model developed by comprehensive field studies on noise measurements (including atmospheric parameters) and control measures. The model has two subsystems constructed on noise reduction quantity in dB. The first subsystem of the fuzzy model depending on 549 linguistic rules comprises acoustical features of all materials used in any workplace. Totally 984 patterns were used, 503 patterns for model development and the rest 481 patterns for testing the model. The second subsystem deals with atmospheric parameter interactions with noise and has 52 linguistic rules. Similarly, 94 field patterns were obtained; 68 patterns were used for training stage of the model and the rest 26 patterns for testing the model. These rules were determined by taking into consideration formal standards, experiences of specialists and the measurements patterns. The results of the model were compared with various statistics (correlation coefficients, max-min, standard deviation, average and coefficient of skewness) and error modes (root mean square error and relative error). The correlation coefficients were significantly high, error modes were quite low and the other statistics were very close to the data. This statement indicates the validity of the model. Therefore, the model can be used for noise control in any workplace and helpful to the designer in planning stage of a workplace.

  18. Comparative Measurements of Earth and Martian Entry Environments in the NASA Langley HYMETS Facility

    NASA Technical Reports Server (NTRS)

    Splinter, Scott C.; Bey, Kim S.; Gragg, Jeffrey G.; Brewer, Amy

    2011-01-01

    Arc-jet facilities play a major role in the development of heat shield materials for entry vehicles because they are capable of producing representative high-enthalpy flow environments. Arc-jet test data is used to certify material performance for a particular mission and to validate or calibrate models of material response during atmospheric entry. Materials used on missions entering Earth s atmosphere are certified in an arc-jet using a simulated air entry environment. Materials used on missions entering the Martian atmosphere should be certified in an arc-jet using a simulated Martian atmosphere entry environment, which requires the use of carbon dioxide. Carbon dioxide has not been used as a test gas in a United States arc-jet facility since the early 1970 s during the certification of materials for the Viking Missions. Materials certified for the Viking missions have been used on every entry mission to Mars since that time. The use of carbon dioxide as a test gas in an arc-jet is again of interest to the thermal protection system community for certification of new heat shield materials that can increase the landed mass capability for Mars bound missions beyond that of Viking and Pathfinder. This paper describes the modification, operation, and performance of the Hypersonic Materials Environmental Test System (HYMETS) arc-jet facility with carbon dioxide as a test gas. A basic comparison of heat fluxes, various bulk properties, and performance characteristics for various Earth and Martian entry environments in HYMETS is provided. The Earth and Martian entry environments consist of a standard Earth atmosphere, an oxygen-rich Earth atmosphere, and a simulated Martian atmosphere. Finally, a preliminary comparison of the HYMETS arc-jet facility to several European plasma facilities is made to place the HYMETS facility in a more global context of arc-jet testing capability.

  19. An atmospheric turbulence and telescope simulator for the development of AOLI

    NASA Astrophysics Data System (ADS)

    Puga, Marta; López, Roberto; King, David; Oscoz, Alejandro

    2014-08-01

    AOLI, Adaptive Optics Lucky Imager, is the next generation of extremely high resolution instruments in the optical range, combining the two more promising techniques: Adaptive optics and lucky imaging. The possibility of reaching fainter objects at maximum resolution implies a better use of weak energy on each lucky image. AOLI aims to achieve this by using an adaptive optics system to reduce the dispersion that seeing causes on the spot and therefore increasing the number of optimal images to accumulate, maximizing the efficiency of the lucky imaging technique. The complexity of developments in hardware, control and software for in-site telescope tests claim for a system to simulate the telescope performance. This paper outlines the requirements and a concept/preliminary design for the William Herschel Telescope (WHT) and atmospheric turbulence simulator. The design consists of pupil resemble, a variable intensity point source, phase plates and a focal plane mask to assist in the alignment, diagnostics and calibration of AOLI wavefront sensor, AO loop and science detectors, as well as enabling stand-alone test operation of AOLI.

  20. Higher fungal diversity is correlated with lower CO2 emissions from dead wood in a natural forest.

    PubMed

    Yang, Chunyan; Schaefer, Douglas A; Liu, Weijie; Popescu, Viorel D; Yang, Chenxue; Wang, Xiaoyang; Wu, Chunying; Yu, Douglas W

    2016-08-24

    Wood decomposition releases almost as much CO2 to the atmosphere as does fossil-fuel combustion, so the factors regulating wood decomposition can affect global carbon cycling. We used metabarcoding to estimate the fungal species diversities of naturally colonized decomposing wood in subtropical China and, for the first time, compared them to concurrent measures of CO2 emissions. Wood hosting more diverse fungal communities emitted less CO2, with Shannon diversity explaining 26 to 44% of emissions variation. Community analysis supports a 'pure diversity' effect of fungi on decomposition rates and thus suggests that interference competition is an underlying mechanism. Our findings extend the results of published experiments using low-diversity, laboratory-inoculated wood to a high-diversity, natural system. We hypothesize that high levels of saprotrophic fungal biodiversity could be providing globally important ecosystem services by maintaining dead-wood habitats and by slowing the atmospheric contribution of CO2 from the world's stock of decomposing wood. However, large-scale surveys and controlled experimental tests in natural settings will be needed to test this hypothesis.

  1. Higher fungal diversity is correlated with lower CO2 emissions from dead wood in a natural forest

    PubMed Central

    Yang, Chunyan; Schaefer, Douglas A.; Liu, Weijie; Popescu, Viorel D.; Yang, Chenxue; Wang, Xiaoyang; Wu, Chunying; Yu, Douglas W.

    2016-01-01

    Wood decomposition releases almost as much CO2 to the atmosphere as does fossil-fuel combustion, so the factors regulating wood decomposition can affect global carbon cycling. We used metabarcoding to estimate the fungal species diversities of naturally colonized decomposing wood in subtropical China and, for the first time, compared them to concurrent measures of CO2 emissions. Wood hosting more diverse fungal communities emitted less CO2, with Shannon diversity explaining 26 to 44% of emissions variation. Community analysis supports a ‘pure diversity’ effect of fungi on decomposition rates and thus suggests that interference competition is an underlying mechanism. Our findings extend the results of published experiments using low-diversity, laboratory-inoculated wood to a high-diversity, natural system. We hypothesize that high levels of saprotrophic fungal biodiversity could be providing globally important ecosystem services by maintaining dead-wood habitats and by slowing the atmospheric contribution of CO2 from the world’s stock of decomposing wood. However, large-scale surveys and controlled experimental tests in natural settings will be needed to test this hypothesis. PMID:27553882

  2. Venusian atmospheric and Magellan properties from attitude control data. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Croom, Christopher A.; Tolson, Robert H.

    1994-01-01

    Results are presented of the study of the Venusian atmosphere, Magellan aerodynamic moment coefficients, moments of inertia, and solar moment coefficients. This investigation is based upon the use of attitude control data in the form of reaction wheel speeds from the Magellan spacecraft. As the spacecraft enters the upper atmosphere of Venus, measurable torques are experienced due to aerodynamic effects. Solar and gravity gradient effects also cause additional torques throughout the orbit. In order to maintain an inertially fixed attitude, the control system counteracts these torques by changing the angular rates of three reaction wheels. Model reaction wheel speeds are compared to observed Magellan reaction wheel speeds through a differential correction procedure. This method determines aerodynamic, atmospheric, solar pressure, and mass moment of inertia parameters. Atmospheric measurements include both base densities and scale heights. Atmospheric base density results confirm natural variability as measured by the standard orbital decay method. Potential inconsistencies in free molecular aerodynamic moment coefficients are identified. Moments of inertia are determined with a precision better than 1 percent of the largest principal moment of inertia.

  3. Opportunities and limitations in low earth subsonic testing for qualification of extraterrestrial supersonic parachute designs

    NASA Technical Reports Server (NTRS)

    Steltzner, A.; Cruz, J.; Bruno, R.; Mitcheltree, R.

    2003-01-01

    Parachutes for Mars and other planetary missions often need to operate at supersonic speeds in very low density atmospheres. Flight testing of such parachutes at appropriate conditions in the Earth's atmosphere is possible at high altitudes.

  4. A moist aquaplanet variant of the Held–Suarez test for atmospheric model dynamical cores

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

    Thatcher, Diana R.; Jablonowski, Christiane

    A moist idealized test case (MITC) for atmospheric model dynamical cores is presented. The MITC is based on the Held–Suarez (HS) test that was developed for dry simulations on “a flat Earth” and replaces the full physical parameterization package with a Newtonian temperature relaxation and Rayleigh damping of the low-level winds. This new variant of the HS test includes moisture and thereby sheds light on the nonlinear dynamics–physics moisture feedbacks without the complexity of full-physics parameterization packages. In particular, it adds simplified moist processes to the HS forcing to model large-scale condensation, boundary-layer mixing, and the exchange of latent and sensible heat betweenmore » the atmospheric surface and an ocean-covered planet. Using a variety of dynamical cores of the National Center for Atmospheric Research (NCAR)'s Community Atmosphere Model (CAM), this paper demonstrates that the inclusion of the moist idealized physics package leads to climatic states that closely resemble aquaplanet simulations with complex physical parameterizations. This establishes that the MITC approach generates reasonable atmospheric circulations and can be used for a broad range of scientific investigations. This paper provides examples of two application areas. First, the test case reveals the characteristics of the physics–dynamics coupling technique and reproduces coupling issues seen in full-physics simulations. In particular, it is shown that sudden adjustments of the prognostic fields due to moist physics tendencies can trigger undesirable large-scale gravity waves, which can be remedied by a more gradual application of the physical forcing. Second, the moist idealized test case can be used to intercompare dynamical cores. These examples demonstrate the versatility of the MITC approach and suggestions are made for further application areas. Furthermore, the new moist variant of the HS test can be considered a test case of intermediate complexity.« less

  5. A moist aquaplanet variant of the Held–Suarez test for atmospheric model dynamical cores

    DOE PAGES

    Thatcher, Diana R.; Jablonowski, Christiane

    2016-04-04

    A moist idealized test case (MITC) for atmospheric model dynamical cores is presented. The MITC is based on the Held–Suarez (HS) test that was developed for dry simulations on “a flat Earth” and replaces the full physical parameterization package with a Newtonian temperature relaxation and Rayleigh damping of the low-level winds. This new variant of the HS test includes moisture and thereby sheds light on the nonlinear dynamics–physics moisture feedbacks without the complexity of full-physics parameterization packages. In particular, it adds simplified moist processes to the HS forcing to model large-scale condensation, boundary-layer mixing, and the exchange of latent and sensible heat betweenmore » the atmospheric surface and an ocean-covered planet. Using a variety of dynamical cores of the National Center for Atmospheric Research (NCAR)'s Community Atmosphere Model (CAM), this paper demonstrates that the inclusion of the moist idealized physics package leads to climatic states that closely resemble aquaplanet simulations with complex physical parameterizations. This establishes that the MITC approach generates reasonable atmospheric circulations and can be used for a broad range of scientific investigations. This paper provides examples of two application areas. First, the test case reveals the characteristics of the physics–dynamics coupling technique and reproduces coupling issues seen in full-physics simulations. In particular, it is shown that sudden adjustments of the prognostic fields due to moist physics tendencies can trigger undesirable large-scale gravity waves, which can be remedied by a more gradual application of the physical forcing. Second, the moist idealized test case can be used to intercompare dynamical cores. These examples demonstrate the versatility of the MITC approach and suggestions are made for further application areas. Furthermore, the new moist variant of the HS test can be considered a test case of intermediate complexity.« less

  6. An in-flight simulator investigation of roll and yaw control power requirements for STOL approach and landing: Development of capability and preliminary results

    NASA Technical Reports Server (NTRS)

    Ellis, D. R.; Raisinghani, S. C.

    1979-01-01

    A six-degree-of-freedom variable-response research aircraft was used to determine the minimum lateral-directional control power required for desirable and acceptable levels of handling qualities for the STOL landing approach task in a variety of simulated atmospheric disturbance conditions for a range of lateral-directional response characteristics. Topics covered include the in-flight simulator, crosswind simulation, turbulence simulation, test configurations, and evaluation procedures. Conclusions based on a limited sampling of simulated STOL transport configurations flown to touchdown out of 6 deg, 75 kt MLS approaches, usually with a sidestep maneuver are discussed.

  7. Effect of antibrowning dips and controlled atmosphere storage on the physico-chemical, visual and nutritional quality of minimally processed "Rojo Brillante" persimmons.

    PubMed

    Sanchís, Elena; Mateos, Milagros; Pérez-Gago, María B

    2017-01-01

    The combined effect of antibrowning dips and controlled atmosphere storage on fresh-cut "Rojo Brillante" persimmon quality was investigated. Persimmon slices were dipped in 10 g L -1 ascorbic acid, 10 g L -1 citric acid or water and were stored in different controlled atmospheres at 5 ℃. Controlled atmosphere conditions were 21 kPa O 2  + 10 kPa CO 2 (Atm-B), 21 kPa O 2  + 20 kPa CO 2 (Atm-C), 5 kPa O 2  + 10 kPa CO 2 (Atm-D) and 5 kPa O 2 in the absence of CO 2 (Atm-E). Air (Atm-A) was used as a control. Atmospheres with high CO 2 concentrations induced darkening, associated with a flesh disorder known as "internal flesh browning". Only the samples placed in Atm-E, and treated with 10 g L -1 ascorbic acid or 10 g L -1 citric acid, controlled enzymatic browning, reduced firmness loss and prevented the "internal flesh browning" disorder. The maximum limit of marketability was achieved in the samples treated with 10 g L -1 citric acid and stored in Atm-E for nine storage days at 5 ℃. The total vitamin C, free radical scavenging activity, total phenolic content and total carotenoids of the fresh-cut "Rojo Brillante" persimmons were affected by maturity stage at harvest, whereas antibrowning dips and controlled atmosphere storage had no clear effect. © The Author(s) 2016.

  8. Flight prototype CO2 and humidity control system

    NASA Technical Reports Server (NTRS)

    Rudy, K. M.

    1979-01-01

    A regenerable CO2 and humidity control system is presently being developed for potential use on shuttle as an alternative to the baseline lithium hydroxide system. The system utilizes a sorbent material (designated HS-C) to adsorb CO2 and the latent heat load from the cabin atmosphere and desorb the CO2 and water vapor overboard when exposed to a space vacuum, thus reducing the overall vehicle heat rejection load. Continuous operation is achieved by utilizing two beds which are alternatively cycled between adsorption and desorption. The HS-C material process was verified. Design concepts for the auxiliary components for the HS-C prototype system were generated. Performance testing verified system effectiveness in controlling CO2 partial pressure and humidity.

  9. A versatile microprocessor-controlled hybrid receiver. [with firmware control for operation over large frequency uncertainty

    NASA Technical Reports Server (NTRS)

    Grant, T. L.

    1978-01-01

    A hybrid receiver has been designed for the Galileo Project. The receiver, located on the Galileo Orbiter, will autonomously acquire and track signals from the first atmospheric probe of Jupiter as well as demodulate, bit-synchronize, and buffer the telemetry data. The receiver has a conventional RF and LF front end but performs multiple functions digitally under firmware control. It will be a self-acquiring receiver that operates under a large frequency uncertainty; it can accommodate different modulation types, bit rates, and other parameter changes via reprogramming. A breadboard receiver and test set demonstrate a preliminary version of the sequential detection process and verify the hypothesis that a fading channel does not reduce the probability of detection.

  10. Postharvest changes in the phenolic profile of watercress induced by post-packaging irradiation and modified atmosphere packaging.

    PubMed

    Pinela, José; Barros, Lillian; Barreira, João C M; Carvalho, Ana Maria; Oliveira, M Beatriz P P; Santos-Buelga, Celestino; Ferreira, Isabel C F R

    2018-07-15

    The effects of γ-ray irradiation and modified atmosphere packaging (MAP) on watercress (Nasturtium officinale R. Br.) phenolic compounds were evaluated after 7-day storage at 4 °C. Irradiation doses of 1, 2 and 5 kGy were tested, as well as vacuum-packaging and MAP enriched with 100% N 2 and Ar. A non-irradiated, air-packaged control was included in all experiments. p-Coumaric acid was the most abundant compound in fresh watercress, followed by quercetin-3-O-sophoroside and isorhamnetin-O-hydroxyferuloylhexoside-O-hexoside. Four kaempferol glycoside derivatives were identified for the first time in this species. In general, flavonoids predominated over phenolic acids. Samples stored under vacuum and irradiated at 2 kGy revealed lower phenolic levels. Ar-enriched MAP and control conditions preserved the initial phenolic content. The 5 kGy dose also maintained concentrations of flavonoids and total phenolic compounds, but increased the phenolic acids content. Additionally, flavonoids were found strongly correlated to DPPH scavenging activity and β-carotene bleaching inhibition capacity. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. The PLATO Dome A site-testing observatory: power generation and control systems.

    PubMed

    Lawrence, J S; Ashley, M C B; Hengst, S; Luong-Van, D M; Storey, J W V; Yang, H; Zhou, X; Zhu, Z

    2009-06-01

    The atmospheric conditions above Dome A, a currently unmanned location at the highest point on the Antarctic plateau, are uniquely suited to astronomy. For certain types of astronomy Dome A is likely to be the best location on the planet, and this has motivated the development of the Plateau Observatory (PLATO). PLATO was deployed to Dome A in early 2008. It houses a suite of purpose-built site-testing instruments designed to quantify the benefits of Dome A site for astronomy, and science instruments designed to take advantage of the observing conditions. The PLATO power generation and control system is designed to provide continuous power and heat, and a high-reliability command and communications platform for these instruments. PLATO has run and collected data throughout the winter 2008 season completely unattended. Here we present a detailed description of the power generation, power control, thermal management, instrument interface, and communications systems for PLATO, and an overview of the system performance for 2008.

  12. The PLATO Dome A site-testing observatory: Power generation and control systems

    NASA Astrophysics Data System (ADS)

    Lawrence, J. S.; Ashley, M. C. B.; Hengst, S.; Luong-van, D. M.; Storey, J. W. V.; Yang, H.; Zhou, X.; Zhu, Z.

    2009-06-01

    The atmospheric conditions above Dome A, a currently unmanned location at the highest point on the Antarctic plateau, are uniquely suited to astronomy. For certain types of astronomy Dome A is likely to be the best location on the planet, and this has motivated the development of the Plateau Observatory (PLATO). PLATO was deployed to Dome A in early 2008. It houses a suite of purpose-built site-testing instruments designed to quantify the benefits of Dome A site for astronomy, and science instruments designed to take advantage of the observing conditions. The PLATO power generation and control system is designed to provide continuous power and heat, and a high-reliability command and communications platform for these instruments. PLATO has run and collected data throughout the winter 2008 season completely unattended. Here we present a detailed description of the power generation, power control, thermal management, instrument interface, and communications systems for PLATO, and an overview of the system performance for 2008.

  13. Development status of regenerable solid amine CO2 control systems

    NASA Technical Reports Server (NTRS)

    Colling, A. K., Jr.; Nalette, T. A.; Cusick, R. J.; Reysa, R. P.

    1985-01-01

    The development history of solid amine/water desorbed (SAWD) CO2 control systems is reviewed. The design of the preprototype SAWD I CO2 system on the basis of a three-man metabolic load at the 3.8 mm Hg ambient CO2 level, and the functions of the CO2 removal, CO2 storage/delivery, controller, and life test laboratory support packages are described. The development of a full-scale multiple canister SAWD II preprototype system, which is capable of conducting the CO2 removal/concentration function in a closed-loop atmosphere revitalization system during zero-gravity operation, is examined. The operation of the SAWD II system, including the absorption and desorption cycles, is analyzed. A reduction in the thermal mass of the canister and the system's energy transfer technique result in efficient energy use. The polyether foam, nylon felt, nickel foam, spring retained, and metal bellows bed tests performed to determine the design of the zero-gravity canister are studied; metal bellows are selected for the canister's configuration.

  14. Load responsive multilayer insulation performance testing

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

    Dye, S.; Kopelove, A.; Mills, G. L.

    Cryogenic insulation designed to operate at various pressures from one atmosphere to vacuum, with high thermal performance and light weight, is needed for cryogenically fueled space launch vehicles and aircraft. Multilayer insulation (MLI) performs well in a high vacuum, but the required vacuum shell for use in the atmosphere is heavy. Spray-on foam insulation (SOFI) is often used in these systems because of its light weight, but can have a higher heat flux than desired. We report on the continued development of Load Responsive Multilayer Insulation (LRMLI), an advanced thermal insulation system that uses dynamic beam discrete spacers that providemore » high thermal performance both in atmosphere and vacuum. LRMLI consists of layers of thermal radiation barriers separated and supported by micromolded polymer spacers. The spacers have low thermal conductance, and self-support a thin, lightweight vacuum shell that provides internal high vacuum in the insulation. The dynamic load responsive spacers compress to support the external load of a vacuum shell in one atmosphere, and decompress under reduced atmospheric pressure for lower heat leak. Structural load testing was performed on the spacers with various configurations. LRMLI was installed on a 400 liter tank and boil off testing with liquid nitrogen performed at various chamber pressures from one atmosphere to high vacuum. Testing was also performed with an MLI blanket on the outside of the LRMLI.« less

  15. Numerical system for monitoring pressurized equipment

    NASA Astrophysics Data System (ADS)

    Dobra, Remus; Pasculescu, Dragos; Boca, Maria Loredana; Moldovan, Lucian

    2016-12-01

    Electrical devices for operation in potentially explosive atmospheres are designed and built in accordance with European standard EN 50015: 1995 ex. the pressurized enclosure "p". The type of protector p, by using a protective gas in the housing is intended to prevent the formation of an explosive atmosphere within it, while maintaining an overpressure to the surrounding atmosphere and, where appropriate, by the use dilution. Research conducted for pressurized encapsulation aimed at developing new procedures for determining the parameters of pressurization to allow safe use of electrical appliances. Pressurization with compensation for losses allegedly maintaining overpressure inside the enclosure when the outlets are closed, is made by feeding protective gas in an amount sufficient to fully compensate for losses from the housing inevitable pressurized and its associated pipework. The conditions and necessary measures that are required for appliances and equipment with potential ignition of explosive atmospheres are detailed in the SR EN 50016/2000. For pressurized encapsulation protection mode, the electric equipment can be maintained safety by the overpressure created inside them and in the supply pipes with air. The paper presents a modern method to determine the parameters of the electric equipment with pressurization enclosures. For controlling of such equipment, a specific algorithm has been developed and laboratory tested.

  16. Lessons Learned from the Development and Implementation of the Atmosphere Resource Recovery and Environmental Monitoring Project

    NASA Technical Reports Server (NTRS)

    Roman, Monsi C.; Perry, Jay L.; Howard, David F.

    2014-01-01

    The Advanced Exploration Systems (AES) Program's Atmosphere Resource Recovery and Environmental Monitoring (ARREM) Project have been developing atmosphere revitalization and environmental monitoring subsystem architectures suitable for enabling sustained crewed exploration missions beyond low Earth orbit (LEO). Using the International Space Station state-of-the-art (SOA) as the technical basis, the ARREM Project has contributed to technical advances that improve affordability, reliability, and functional efficiency while reducing dependence on a ground-based logistics resupply model. Functional demonstrations have merged new process technologies and concepts with existing ISS developmental hardware and operate them in a controlled environment simulating various crew metabolic loads. The ARREM Project's strengths include access to a full complement of existing developmental hardware that perform all the core atmosphere revitalization functions, unique testing facilities to evaluate subsystem performance, and a coordinated partnering effort among six NASA field centers and industry partners to provide the innovative expertise necessary to succeed. A project overview is provided and the project management strategies that have enabled a multidiscipinary engineering team to work efficiently across project, NASA field center, and industry boundaries to achieve the project's technical goals are discussed. Lessons learned and best practices relating to the project are presented and discussed.

  17. THEORETICAL TRANSIT SPECTRA FOR GJ 1214b AND OTHER 'SUPER-EARTHS'

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

    Howe, Alex R.; Burrows, Adam S., E-mail: arhowe@astro.princeton.edu, E-mail: burrows@astro.princeton.edu

    2012-09-10

    We present new calculations of transit spectra of super-Earths that allow for atmospheres with arbitrary proportions of common molecular species and haze. We test this method with generic spectra, reproducing the expected systematics and absorption features, then apply it to the nearby super-Earth GJ 1214b, which has produced conflicting observational data, leaving the questions of a hydrogen-rich versus hydrogen-poor atmosphere and the water content of the atmosphere ambiguous. We present representative transit spectra for a range of classes of atmosphere models for GJ 1214b. Our analysis supports a hydrogen-rich atmosphere with a cloud or haze layer, although a hydrogen-poor modelmore » with {approx}<10% water is not ruled out. Several classes of models are ruled out, however, including hydrogen-rich atmospheres with no haze, hydrogen-rich atmospheres with a haze of {approx}0.01 {mu}m tholin particles, and hydrogen-poor atmospheres with major sources of absorption other than water. We propose an observational test to distinguish hydrogen-rich from hydrogen-poor atmospheres. Finally, we provide a library of theoretical transit spectra for super-Earths with a broad range of parameters to facilitate future comparison with anticipated data.« less

  18. Achieving and documenting closure in plant growth facilities

    NASA Technical Reports Server (NTRS)

    Knott, W. M.; Sager, John C.; Wheeler, Ray

    1992-01-01

    As NASA proceeds with its effort to develop a Controlled Ecological Life Support System (CELSS) that will provide life support to crews during long duration space missions, it must address the question of facility and system closure. The concept of closure as it pertains to CELSS and engineering specifications, construction problems and monitoring procedures used in the development and operation of a closed plant growth facility for the CELSS program are described. A plant growth facility is one of several modules required for a CELSS. A prototype of this module at Kennedy Space Center is the large (7m tall x 3.5m diameter) Biomass Production Chamber (BPC), the central facility of the CELSS Breadboard Project. The BPC is atmospherically sealed to a leak rate of approximately 5 percent of its total volume per 24 hours. This paper will discuss the requirements for atmospheric closure in the facility, present CO2 and trace gas data from initial tests of the BPC with and without plants, and describe how the chamber was sealed atmospherically. Implications that research conducted in this type of facility will have for the CELSS program are discussed.

  19. A conduit dilation model of methane venting from lake sediments

    USGS Publications Warehouse

    Scandella, B.P.; Varadharajan, C.; Hemond, Harold F.; Ruppel, C.; Juanes, R.

    2011-01-01

    Methane is a potent greenhouse gas, but its effects on Earth's climate remain poorly constrained, in part due to uncertainties in global methane fluxes to the atmosphere. An important source of atmospheric methane is the methane generated in organic-rich sediments underlying surface water bodies, including lakes, wetlands, and the ocean. The fraction of the methane that reaches the atmosphere depends critically on the mode and spatiotemporal characteristics of free-gas venting from the underlying sediments. Here we propose that methane transport in lake sediments is controlled by dynamic conduits, which dilate and release gas as the falling hydrostatic pressure reduces the effective stress below the tensile strength of the sediments. We test our model against a four-month record of hydrostatic load and methane flux in Upper Mystic Lake, Mass., USA, and show that it captures the complex episodicity of methane ebullition. Our quantitative conceptualization opens the door to integrated modeling of methane transport to constrain global methane release from lakes and other shallow-water, organic-rich sediment systems, and to assess its climate feedbacks.

  20. Airborne Lidar for Simultaneous Measurement of Column CO2 and Water Vapor in the Atmosphere

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Petros, Mulugeta; Refaat, Tamer F.; Antill, Charles W.; Remus, Ruben; Yu, Jirong

    2016-01-01

    The 2-micron wavelength region is suitable for atmospheric carbon dioxide (CO2) measurements due to the existence of distinct absorption feathers for the gas at this particular wavelength. For more than 20 years, researchers at NASA Langley Research Center (LaRC) have developed several high-energy and high repetition rate 2-micron pulsed lasers. This paper will provide status and details of an airborne 2-micron triple-pulse integrated path differential absorption (IPDA) lidar. The development of this active optical remote sensing IPDA instrument is targeted for measuring both CO2 and water vapor (H2O) in the atmosphere from an airborne platform. This presentation will focus on the advancement of the 2-micron triple-pulse IPDA lidar development. Updates on the state-of-the-art triple-pulse laser transmitter will be presented including the status of seed laser locking, wavelength control, receiver telescope, detection system and data acquisition. Future plans for the IPDA lidar system for ground integration, testing and flight validation will also be presented.

  1. The Effect of Increased CO2 Mixing Ratio on Water Use Efficiency, Evapo-transpiration, Soil Moisture Content and Stem Flow in two Long-term Field Experiments

    NASA Astrophysics Data System (ADS)

    Drake, B.; Powell, T.; Li, J.; Hinkle, R.; Rasse, D.

    2007-12-01

    Stomatal opening in plant leaves control carbon and water exchange between vegetation and the atmosphere. Closure of these water-gates in response to increased atmospheric CO2 mixing ratio's, reduces transpiration under most laboratory and short term experimental conditions. Does this imply however, as atmospheric CO2 rises, and plant canopies expand, that evapo-transpiration (ETR), soil moisture content (SMC), and ecosystem water use efficiency (WUE) will increase? To test this question, field experiments have been and still are conducted using open top chambers. We have exposed native species in Florida Scrub to a carbon dioxide mixing ratio of nearly 700 ppmv CO2 for the past ten years and in Chesapeake Bay wetlands for 21 years. As a result of this treatment, in both ecosystems there was an increase in net ecosystem CO2 exchange and leaf area but a reduction of stomatal conductance, stem flow, transpiration, and ETR. For Florida scrub oak, these changes were also accompanied by an increase in soil moisture content as well.

  2. On the use of pulsed Dielectric Barrier Discharges to control the gas-phase composition of atmospheric pressure air plasmas

    NASA Astrophysics Data System (ADS)

    Barni, R.; Biganzoli, I.; Dell'Orto, E.; Riccardi, C.

    2014-11-01

    We presents results obtained from the numerical simulation of the gas-phase chemical kinetics in atmospheric pressure air non-equilibrium plasmas. In particular we have addressed the effect of pulsed operation mode of a plane dielectric barrier discharge. It was conjectured that the large difference in the time scales involved in the fast dissociation of oxygen molecules in plasma and their subsequent reactions to produce ozone and nitrogen oxides, makes the presence of a continuously repeated plasma production unnecessary and a waste of electrical power and thus efficiency. In order to test such suggestion we have performed a numerical study of the composition and the temporal evolution of the gas-phase of atmospheric pressure air non-equilibrium plasmas. Comparison with experimental findings in a dielectric barrier discharge with an electrode configuration symmetrical and almost ideally plane is briefly addressed too, using plasma diagnostics to extract the properties of the single micro-discharges and a sensor to measure the concentration of ozone produced by the plasma.

  3. Coherent launch-site atmospheric wind sounder - Theory and experiment

    NASA Technical Reports Server (NTRS)

    Hawley, James G.; Targ, Russell; Henderson, Sammy W.; Hale, Charley P.; Kavaya, Michael J.; Moerder, Daniel

    1993-01-01

    The coherent launch-site atmospheric wind sounder (CLAWS) is a lidar atmospheric wind sensor designed to measure the winds above space launch facilities to an altitude of 20 km. In our development studies, lidar sensor requirements are defined, a system to meet those requirements is defined and built, and the concept is evaluated, with recommendations for the most feasible and cost-effective lidar system for use as an input to a guidance and control system for missile or spacecraft launches. The ability of CLAWS to meet NASA goals for increased safety and launch/mission flexibility is evaluated in a field test program at Kennedy Space Center (KSC) in which we investigate maximum detection range, refractive turbulence, and aerosol backscattering efficiency. The Nd:YAG coherent lidar operating at 1.06 micron with 1-J energy per pulse is able to make real-time measurements of the 3D wind field at KSC to an altitude of 26 km, in good agreement with our performance simulations. It also shows the height and thickness of the volcanic layer caused by the volcanic eruption of Mount Pinatubo in the Philippines.

  4. Modeling of Water Flow Processes in the Soil-Plant-Atmosphere System: The Soil-Tree-Atmosphere Continuum Model

    NASA Astrophysics Data System (ADS)

    Massoud, E. C.; Vrugt, J. A.

    2015-12-01

    Trees and forests play a key role in controlling the water and energy balance at the land-air surface. This study reports on the calibration of an integrated soil-tree-atmosphere continuum (STAC) model using Bayesian inference with the DREAM algorithm and temporal observations of soil moisture content, matric head, sap flux, and leaf water potential from the King's River Experimental Watershed (KREW) in the southern Sierra Nevada mountain range in California. Water flow through the coupled system is described using the Richards' equation with both the soil and tree modeled as a porous medium with nonlinear soil and tree water relationships. Most of the model parameters appear to be reasonably well defined by calibration against the observed data. The posterior mean simulation reproduces the observed soil and tree data quite accurately, but a systematic mismatch is observed between early afternoon measured and simulated sap fluxes. We will show how this points to a structural error in the STAC-model and suggest and test an alternative hypothesis for root water uptake that alleviates this problem.

  5. The Skylab concentrated atmospheric radiation project

    NASA Technical Reports Server (NTRS)

    Kuhn, P. M.; Marlatt, W. E.; Whitehead, V. S. (Principal Investigator)

    1975-01-01

    The author has identified the following significant results. Comparison of several existing infrared radiative transfer models under somewhat controlled conditions and with atmospheric observations of Skylab's S191 and S192 radiometers illustrated that the models tend to over-compute atmospheric attenuation in the window region of the atmospheric infrared spectra.

  6. Direct and indirect effects of atmospheric conditions and soil moisture on surface energy partitioning revealed by a prolonged drought at a temperate forest site

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

    Gu, Lianhong; Meyers, T. P.; Pallardy, Stephen G.

    2006-01-01

    The purpose of this paper is to examine the mechanism that controls the variation of surface energy partitioning between latent and sensible heat fluxes at a temperate deciduous forest site in central Missouri, USA. Taking advantage of multiple micrometeorological and ecophysiological measurements and a prolonged drought in the middle of the 2005 growing season at this site, we studied how soil moisture, atmospheric vapor pressure deficit (VPD), and net radiation affected surface energy partitioning. We stratified these factors to minimize potential confounding effects of correlation among them. We found that all three factors had direct effects on surface energy partitioning,more » but more important, all three factors also had crucial indirect effects. The direct effect of soil moisture was characterized by a rapid decrease in Bowen ratio with increasing soil moisture when the soil was dry and by insensitivity of Bowen ratio to variations in soil moisture when the soil was wet. However, the rate of decrease in Bowen ratio when the soil was dry and the level of soil moisture above which Bowen ratio became insensitive to changes in soil moisture depended on atmospheric conditions. The direct effect of increased net radiation was to increase Bowen ratio. The direct effect of VPD was very nonlinear: Increased VPD decreased Bowen ratio at low VPD but increased Bowen ratio at high VPD. The indirect effects were much more complicated. Reduced soil moisture weakened the influence of VPD but enhanced the influence of net adiation on surface energy partitioning. Soil moisture also controlled how net radiation influenced the relationship between surface energy partitioning and VPD and how VPD affected the relationship between surface energy partitioning and net radiation. Furthermore, both increased VPD and increased net radiation enhanced the sensitivity of Bowen ratio to changes in soil moisture and the effect of drought on surface energy partitioning. The direct and indirect effects of atmospheric conditions and soil moisture on surface energy partitioning identified in this paper provide a target for testing atmospheric general circulation models in their representation of land-atmosphere coupling.« less

  7. Airborne water vapor DIAL research: System development and field measurements

    NASA Technical Reports Server (NTRS)

    Higdon, Noah S.; Browell, Edward V.; Ponsardin, Patrick; Chyba, Thomas H.; Grossmann, Benoist E.; Butler, Carolyn F.; Fenn, Marta A.; Mayor, Shane D.; Ismail, Syed; Grant, William B.

    1992-01-01

    This paper describes the airborne differential absorption lidar (DIAL) system developed at the NASA Langley Research Center for remote measurement of water vapor (H2O) and aerosols in the lower atmosphere. The airborne H2O DIAL system was flight tested aboard the NASA Wallops Flight Facility (WFF) Electra aircraft in three separate field deployments between 1989 and 1991. Atmospheric measurements were made under a variety of atmospheric conditions during the flight tests, and several modifications were implemented during this development period to improve system operation. A brief description of the system and major modifications will be presented, and the most significant atmospheric observations will be described.

  8. The IRAM 30-m millimeter radio telescope on Pico Veleta, Spain

    NASA Astrophysics Data System (ADS)

    Baars, J. W. M.; Hooghoudt, B. G.; Mezger, P. G.; de Jonge, M. J.

    1987-03-01

    In the Spanish Sierra Nevada near 2900 m altitude, the new 30-m telescope for millimeter astronomy is now operational. The authors describe the original design features, which resulted in the high reflector and pointing accuracy, necessary for operation near 1 mm wavelength. The open air telescope is thermally insulated and the temperature of critical sections is controlled to better than 1 K day and night. A reflector surface error of about 80 μm and a pointing and tracking accuracy of about 1arcsec in wind velocities of 12 m s-1 and under stable atmospheric conditions have been reached. These can be further improved. Receivers are available for the 3, 2, and 1.2 mm atmospheric windows. First tests at 0.87 mm have confirmed the high quality of this instrument.

  9. Elastic airtight container for the compaction of air-sensitive materials

    NASA Astrophysics Data System (ADS)

    Shoulders, W. Taylor; Locke, Richard; Gaume, Romain M.

    2016-06-01

    We report on the design and fabrication of a simple and versatile elastic canister for the compaction and hot-pressing of air-sensitive materials. This device consists of a heated double-ended floating die assembly, enclosed in a compressible stainless steel bellows that allows the action of an external hydraulic press in a uniaxial motion. The enclosure is fitted with vacuum, gas, and electrical feedthroughs to allow for atmosphere control, heating, and in situ process monitoring. The overall chamber is compact enough to be portable and transferrable into and out of a standard laboratory glovebox, thus eliminating the problem of exposing samples to ambient atmosphere during loading and unloading. Our design has been tested up to 600 °C and 7500 kg-force applied load, conditions within which transparent ceramics of anhydrous halides can be produced.

  10. System development and early biological tests in NASA's biomass production chamber

    NASA Technical Reports Server (NTRS)

    Wheeler, R. M.; Mackowiak, C. L.; Dreschel, T. W.; Sager, J. C.; Prince, R. P.; Knott, W. M.; Hinkle, C. R.; Strayer, R. F.

    1990-01-01

    The Biomass Production Chamber at Kennedy Space Center was constructed to conduct large scale plant growth studies for NASA's CELSS program. Over the past four years, physical systems and computer control software have been continually upgraded and the degree of atmospheric leakage from the chamber has decreased from about 40 to 5 percent of the total volume per day. Early tests conducted with a limited degree of closure showed that total crop (wheat) growth from the best trays was within 80 percent of reported optimal yields for similar light levels. Yields from subsequent tests under more tightly closed conditions have not been as good--up to only 65 percent of optimal yields. Yields appear to have decreased with increasing closure, yet potential problems exist in cultural techniques and further studies are warranted. With the ability to tightly seal the chamber, quantitative data were gathered on CO2 and water exchange rates. Results showed that stand photosynthesis and transpiration reached a peak near 25 days after planting, soon after full vegetative ground cover was established. In the final phase of testing when atmospheric closure was the highest, ethylene gas levels in the chamber rose from about 10 to nearly 120 ppb. Evidence suggests that the ethylene originated from the wheat plants themselves and may have caused an epinastic rolling of the leaves, but no apparent detrimental effects on whole plant function.

  11. Tuning model drug release and soft-tissue bioadhesion of polyester films by plasma post-treatment.

    PubMed

    Mogal, Vishal T; Yin, Chaw Su; O'Rorke, Richard; Boujday, Souhir; Méthivier, Christophe; Venkatraman, Subbu S; Steele, Terry W J

    2014-04-23

    Plasma treatments are investigated as a post-production method of tuning drug release and bioadhesion of poly(lactic-co-glycolic acid) (PLGA) thin films. PLGA films were treated under varying conditions by controlling gas flow rate, composition, treatment time, and radio frequency (RF) power. In vitro release of the drug-like molecule fluorescein diacetate (FDAc) from plasma-treated PLGA was tunable by controlling RF power; an increase of 65% cumulative release is reported compared to controls. Bioadhesion was sensitive to RF power and treatment time, assessed using ex vivo shear-stress tests with wetted swine aorta. We report a maximum bioadhesion ∼6-fold that of controls and 5-fold that of DOPA-based mussel adhesives tested to swine skin.1 The novelty of this post-treatment is the activation of a hydrophobic polyester film for bioadhesion, which can be quenched, while simultaneously tuning drug-release kinetics. This exemplifies the promise of plasma post-treatment for in-clinic bioadhesive activation, along with technological advancements, i.e., atmospheric plasma and hand-held "plasma pencils".

  12. Distribution of radionuclides between atmosphere and ash during combustion of contaminated vegetation.

    PubMed

    Zhou, Liufang Jenny; Rao, Raghu; Corcoran, Emily; Kelly, David

    2016-12-01

    A series of laboratory-scale combustion tests were conducted under well-controlled conditions to measure the release of 90 Sr and 137 Cs nuclides to the atmosphere (air) from combustion of vegetation and organic soil samples contaminated with radioactivity. These vegetation and soil samples were collected from a controlled contaminated forest area within the Canadian Nuclear Laboratories - Chalk River site. The combustion products including ash and smoke particulates, along with gaseous emissions, were collected and then analyzed for 137 Cs and 90 Sr concentrations by radiometric techniques. The experimental results reveal that the releases of 90 Sr to the atmosphere (air) from combustion of vegetation are very low with most of the 90 Sr activity remaining in ash residues, even at a temperature of 800 °C. The detailed combustion experiments with surface litter and twigs, alder twigs, alder leaves, and organic soil indicate that 0.5 ± 0.1%, 0.3 ± 0.1%, 0.9 ± 0.1%, and 0.3 ± 0.1% of 90 Sr is released to the atmosphere (air), respectively. On the other hand, the releases of 137 Cs are found to be highly dependent on the combustion temperature as well as the nature of vegetation. The releases of 137 Cs obtained at 800 °C are 45 ± 7%, 77 ± 9%, 92 ± 5%, and 2.4 ± 0.5% for surface litter and twigs, alder twigs, alder leaves, and organic soil, respectively. The mechanism associated with the high release of 137 Cs at a high temperature of 800 °C was explored. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  13. Uncertainties in Isoprene Photochemistry and Emissions: Implications for the Oxidative Capacity of Past and Present Atmospheres and for Climate Forcing Agents

    NASA Technical Reports Server (NTRS)

    Achakulwisut, P.; Mickley, L. J.; Murray, Lee; Tai, A.P.K.; Kaplan, J.O.; Alexander, B.

    2015-01-01

    Current understanding of the factors controlling biogenic isoprene emissions and of the fate of isoprene oxidation products in the atmosphere has been evolving rapidly. We use a climate-biosphere-chemistry modeling framework to evaluate the sensitivity of estimates of the tropospheric oxidative capacity to uncertainties in isoprene emissions and photochemistry. Our work focuses on trends across two time horizons: from the Last Glacial Maximum (LGM, 21 000 years BP) to the preindustrial (1770s); and from the preindustrial to the present day (1990s). We find that different oxidants have different sensitivities to the uncertainties tested in this study, with OH being the most sensitive: changes in the global mean OH levels for the LGM-to-preindustrial transition range between -29 and +7, and those for the preindustrial-to-present day transition range between -8 and +17, across our simulations. Our results suggest that the observed glacial-interglacial variability in atmospheric methane concentrations is predominantly driven by changes in methane sources as opposed to changes in OH, the primary methane sink. However, the magnitudes of change are subject to uncertainties in the past isoprene global burdens, as are estimates of the change in the global burden of secondary organic aerosol (SOA) relative to the preindustrial. We show that the linear relationship between tropospheric mean OH and tropospheric mean ozone photolysis rates, water vapor, and total emissions of NOx and reactive carbon first reported in Murray et al. (2014) does not hold across all periods with the new isoprene photochemistry mechanism. Our results demonstrate that inadequacies in our understanding of present-day OH and its controlling factors must be addressed in order to improve model estimates of the oxidative capacity of past and present atmospheres.

  14. A new test method for the assessment of the arc tracking properties of wire insulation in air, oxygen enriched atmospheres and vacuum

    NASA Technical Reports Server (NTRS)

    Koenig, Dieter

    1994-01-01

    Development of a new test method suitable for the assessment of the resistance of aerospace cables to arc tracking for different specific environmental and network conditions of spacecraft is given in view-graph format. The equipment can be easily adapted for tests at different realistic electrical network conditions incorporating circuit protection and the test system works equally well whatever the test atmosphere. Test results confirm that pure Kapton insulated wire has bad arcing characteristics and ETFE insulated wire is considerably better in air. For certain wires, arc tracking effects are increased at higher oxygen concentrations and significantly increased under vacuum. All tests on different cable insulation materials and in different environments, including enriched oxygen atmospheres, resulted in a more or less rapid extinguishing of all high temperature effects at the beginning of the post-test phase. In no case was a self-maintained fire initiated by the arc.

  15. Environmental and alloying effects on corrosion of metals and alloys

    NASA Astrophysics Data System (ADS)

    Liang, Dong

    2009-12-01

    In the first part of this project, corrosion studies were carried out on 304L stainless steel samples welded with Cr-free consumables, which were developed to minimize the concentration of chromate species in the weld fume. The corrosion properties of Ni-Cu and Ni-Cu-Pd Gas Tungsten Arc (GTA) welds and Shielded Metal Arc (SMA) welds are comparable to those of welds fabricated with SS308L consumable, which is the standard consumable for welding 304L. Although the breakdown potentials of the new welds from both welding processes are lower than that of the SS308L weld, the repassivation potential of these new welds is much higher. Generally, the repassivation potential is a more conservative measure of susceptibility to localized corrosion. Our studies showed that the Ni-Cu and Ni-Cu-Pd welds are more resistant to crevice corrosion than SS308L welds, which is related to the high repassivation potential. Also, addition of Pd improved the corrosion resistance of the new welds, which is consistent with previous studies from button samples and bead-on-plate samples. Other corrosion studies such as creviced and uncreviced long time immersion, atmospheric exposure, and slow strain rate testing suggest that Ni-Cu-Pd welds can be a qualified substitute for SS308 weld. In the second part of this project, efforts are put on the connection between lab and field exposure tests because sometimes the correspondence between lab atmospheric corrosion tests (ASTM B117) and field exposures is poor as a result of differences in the critical conditions controlling chemical and electrochemical reactions on surfaces. Recent studies in atmospheric chemistry revealed the formation of extremely reactive species from interactions between UV light, chloride aerosols above oceans and oxidizing agents such as ozone or peroxide. Atmospheric corrosion of metals can be affected by these species which might be transported long distances in the atmosphere to locations far from oceans. However, these species could be missed in standard laboratory exposures such as ASTM B117. Initial efforts focused on the effects UV radiation, O3, relative humidity on the atmospheric corrosion of bare silver. Later work addressed the corrosion of silver samples deposited with NaCl particles. An exposure chamber that can simulate various environmental effects was built. The effects of UV radiation, O3, and relative humidity were varied separately while keeping the other factors the same level. The corrosion products were analyzed by the galvanostatic reduction method and characterization techniques such as SEM and EDS. It was found that both UV and O3 are necessary for fast corrosion on bare silver and this fast corrosion reaction results from atomic oxygen generated photodegradation of O3. In the presence of UV and O3, relative humidity has little effect on the atmospheric corrosion of bare silver in contrast to conventional atmospheric corrosion. The degree of corrosion is found to increase with O3 concentration. Moreover, a kinetic study of atmospheric corrosion of bare silver found that an incubation time for the atmospheric corrosion attack is needed. This incubation time is related to the chemisorption process of atomic oxygen. Though UV radiation can form reactive atomic oxygen which is more reactive than O3 alone as shown in the last chapter, the enhancement of corrosion by UV is limited for Ag with NaCl particles at low ozone concentration and high RH. The corrosion rate of silver with NaCl particles is found to increase with relative humidity, which is different than the case of bare silver. This indicates that different mechanisms control the atmospheric corrosion of silver. The incubation time for corrosion of silver with NaCl particles is shorter than for bare silver. This result from chemisorption of Cl 2 is favored over that of atomic oxygen. Interestingly, the total corrosion product of silver with NaCl particles is less than that of bare silver. This could be due to limited amount of NaCl and also higher oxidizing power of atomic oxygen. Finally, bare silver samples were exposed in salt spray chamber according to ASTM B117 up to 4 months. Very little corrosion products were detected after exposure, which is attributed to the lack of reactive species such as O and O3 in the environment. (Abstract shortened by UMI.)

  16. Validation of ammonia diffusive and active samplers in a controlled atmosphere test facility using traceable Primary Standard Gas Mixtures

    NASA Astrophysics Data System (ADS)

    Martin, Nicholas A.; Ferracci, Valerio; Cassidy, Nathan; Hook, Josh; Battersby, Ross M.; Tang, Yuk S.; Stevens, Amy C. M.; Jones, Matthew R.; Braban, Christine F.; Gates, Linda; Hangartner, Markus; Stoll, Jean-Marc; Sacco, Paolo; Pagani, Diego; Hoffnagle, John A.

    2017-04-01

    Intensive animal farming, the increased use of fertilizers, and certain industrial processes are believed to be responsible for the observed increases in the amount fraction of ammonia (NH3) found in Europe. NH3 contributes to eutrophication and acidification of land and freshwater, potentially leading to a loss of biodiversity and undesirable changes to the ecosystem. It also contributes to the formation of secondary particulate matter (PM) formation, which is associated with poor air quality and adverse health outcomes. Measurements of ambient ammonia are principally carried out with low-cost diffusive samplers or by active sampling with denuders, with each method delivering time-integrated values over the monitoring period. However, such techniques have not yet been extensively validated. The goal of this work was to provide improvements in the metrological traceability through the determination of NH3 diffusive sampling rates. Five different designs of commercial diffusive samplers (FSM Radiello radial sampler, Gradko diffusion tube, Gradko DIFRAM-400, Passam ammonia sampler, and CEH ALPHA sampler) were employed, together with a pumped denuder sampler (CEH DELTA denuder) for comparison. All devices were simultaneously exposed for either 28 days or 14 days (dependent on sampler type) in a controlled atmosphere test facility (CATFAC) containing traceable amount fractions of humidified ammonia using new stable ammonia Primary Standard Gas Mixtures developed by gravimetry at NPL, under a wide range of conditions that are relevant to ambient monitoring. Online continuous monitoring of the ammonia test atmospheres was carried out by extractive sampling, employing a calibrated cavity ring-down spectrometer, which had been modified to account for cross interference by water vapour. Each manufacturer extracted the captured ammonia on the exposed samplers in the form of ammonium (NH4+) using their own accredited traceable wet chemical techniques, and then reported data based on their historical diffusive sampling rates. There was considerable variation in the results, which demonstrated the need for such validation work to be carried out. We report new measurements of the NH3 sampling rates determined in the CATFAC, which can be applied to improve the reliability of measurements in the field.

  17. GREENHOUSE GASES (ATMOSPHERIC PROTECTION BRANCH, AIR POLLUTION PREVENTION AND CONTROL DIVISION, NRMRL)

    EPA Science Inventory

    Greenhouse gas (GHG) emissions are projected for various scenarios and the most appropriate approaches and technologies for mitigation are identified by NRMRL's Air Pollution Prevention and Control Division's Atmospheric Protection Branch (APB). These methods contribute to reduct...

  18. Controlling Brochothrix thermosphacta as a spoilage risk using in-package atmospheric cold plasma.

    PubMed

    Patange, Apurva; Boehm, Daniela; Bueno-Ferrer, Carmen; Cullen, P J; Bourke, Paula

    2017-09-01

    Brochothrix thermosphacta is the predominant spoilage microorganism in meat and its control in processing environments is important to maintain meat product quality. Atmospheric cold plasma is of interest for control of pathogenic and spoilage microorganisms in foods. This study ascertained the potential of dielectric barrier discharge atmospheric cold plasma (DBD-ACP) for control of B. thermosphacta, taking microbial and food environment factors into consideration, and investigated the shelf-life of lamb chop after in-package plasma treatment in modified atmosphere. Community profiling was used to assess the treatment effects on the lamb microflora. ACP treatment (80 kV) for 30s inactivated B. thermosphacta populations below detection levels in PBS, while 5 min treatment achieved a 2 Log cycle reduction using a complex meat model medium and attached cells. The antimicrobial efficacy of plasma was reduced but still apparent on lamb chop surface-inoculated with high concentrations of B. thermosphacta. Lamb chop treated under modified atmosphere exhibited reduced microbial growth over the product shelf-life and community profiling showed no evident changes to the microbial populations after the treatment. The overall results indicated potential of ACP to enhance microbial control leading to meat storage life extension through adjusting the modality of treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Surface atmospheric extremes (Launch and transportation areas)

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The effects of extreme values of surface and low altitude atmospheric parameters on space vehicle design, tests, and operations are discussed. Atmospheric extremes from the surface to 150 meters for geographic locations of interest to NASA are given. Thermal parameters (temperature and solar radiation), humidity, pressure, and atmospheric electricity (lighting and static) are presented. Weather charts and tables are included.

  20. Plants survive rapid decompression: Implications for bioregenerative life support

    NASA Astrophysics Data System (ADS)

    Wheeler, R. M.; Wehkamp, C. A.; Stasiak, M. A.; Dixon, M. A.; Rygalov, V. Y.

    2011-05-01

    Radish (Raphanus sativus), lettuce (Latuca sativa), and wheat (Triticum aestivum) plants were grown at either 98 kPa (ambient) or 33 kPa atmospheric pressure with constant 21 kPa oxygen and 0.12 kPa carbon dioxide in atmospherically closed pressure chambers. All plants were grown rockwool using recirculating hydroponics with a complete nutrient solution. At 20 days after planting, chamber pressures were pumped down as rapidly as possible, reaching 5 kPa after about 5 min and ˜1.5 kPa after about 10 min. The plants were held at 1.5 kPa for 30 min and then pressures were restored to their original settings. Temperature (22 °C) and humidity (65% RH) controls were engaged throughout the depressurization, although temperatures dropped to near 16 °C for a brief period. CO2 and O2 were not detectable at the low pressure, suggesting that most of the 1.5 kPa atmosphere consisted of water vapor. Following re-pressurization, plants were grown for another 7 days at the original pressures and then harvested. The lettuce, radish, and wheat plants showed no visible effects from the rapid decompression, and there were no differences in fresh or dry mass when compared to control plants maintained continuously at 33 or 98 kPa. But radish storage root fresh mass and lettuce head fresh and dry masses were less at 33 kPa compared to 98 kPa for both the controls and decompression treatment. The results suggest that plants are extremely resilient to rapid decompression, provided they do not freeze (from evaporative cooling) or desiccate. The water of the hydroponic system was below the boiling pressure during these tests and this may have protected the plants by preventing pressures from dropping below 1.5 kPa and maintaining humidity near 1.5 kPa. Further testing is needed to determine how long plants can withstand such low pressure, but the results suggest there are at least 30 min to respond to catastrophic pressure losses in a plant production chamber that might be used for life support in space.

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