ASSESSMENT OF VAPOR INTRUSION USING INDOOR AND SUB-SLAB AIR SAMPLING

EPA Science Inventory

The objective of this investigation was to develop a method for evaluating vapor intrusion using indoor and sub-slab air measurement and at the same time directly assist EPA’s New England Regional Office in evaluating vapor intrusion in 15 homes and one business near the former R...

Ground Source Heat Pump Sub-Slab Heat Exchange Loop Performance in a Cold Climate

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

Mittereder, N.; Poerschke, A.

2013-11-01

This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab. Prior to the installation and operation of the sub-slab heat exchanger, energy modeling using TRNSYS software and concurrent design efforts were performed to determine the size and orientation of the system. One key parameter in the design is the installation of the GSHPmore » in a low-load home, which considerably reduces the needed capacity of the ground loop heat exchanger. This report analyzes data from two cooling seasons and one heating season. Upon completion of the monitoring phase, measurements revealed that the initial TRNSYS simulated horizontal sub-slab ground loop heat exchanger fluid temperatures and heat transfer rates differed from the measured values. To determine the cause of this discrepancy, an updated model was developed utilizing a new TRNSYS subroutine for simulating sub-slab heat exchangers. Measurements of fluid temperature, soil temperature, and heat transfer were used to validate the updated model.« less

Release of dissolved nitrogen from water during depressurization

NASA Technical Reports Server (NTRS)

Simoneau, R. J.

1978-01-01

Experiments were run to study depressurization of water containing various concentrations of dissolved nitrogen gas, the primary case being room temperature water saturated with nitrogen at 4 MPa. In a static depressurization experiment, water with very high nitrogen content was depressurized at rates from 0.09 to 0.50 MPa per second and photographed with high speed movies. The pictures showed that the bubble population at a given pressure increased strongly with decreasing depressurization rate. Flow experiments were performed in an axisymmetric converging-diverging nozzle and in a two-dimensional converging nozzle with glass sidewalls. Depressurization gradients were roughly 500 to 1200 MPa per second. Both nozzles exhibited choked flow behavior even at nitrogen concentration levels as low as 4 percent of saturated. The flow rates were independent of concentration level and could be computed as incompressible water flow based on the difference between stagnation and throat pressures; however, the throat pressures were significantly different between the two nozzles.

Seismic anisotropy in the Hellenic subduction zone: Effects of slab segmentation and subslab mantle flow

NASA Astrophysics Data System (ADS)

Evangelidis, C. P.

2017-12-01

The segmentation and differentiation of subducting slabs have considerable effects on mantle convection and tectonics. The Hellenic subduction zone is a complex convergent margin with strong curvature and fast slab rollback. The upper mantle seismic anisotropy in the region is studied focusing at its western and eastern edges in order to explore the effects of possible slab segmentation on mantle flow and fabrics. Complementary to new SKS shear-wave splitting measurements in regions not adequately sampled so far, the source-side splitting technique is applied to constrain the depth of anisotropy and to densify measurements. In the western Hellenic arc, a trench-normal subslab anisotropy is observed near the trench. In the forearc domain, source-side and SKS measurements reveal a trench-parallel pattern. This indicates subslab trench-parallel mantle flow, associated with return flow due to the fast slab rollback. The passage from continental to oceanic subduction in the western Hellenic zone is illustrated by a forearc transitional anisotropy pattern. This indicates subslab mantle flow parallel to a NE-SW smooth ramp that possibly connects the two subducted slabs. A young tear fault initiated at the Kefalonia Transform Fault is likely not entirely developed, as this trench-parallel anisotropy pattern is observed along the entire western Hellenic subduction system, even following this horizontal offset between the two slabs. At the eastern side of the Hellenic subduction zone, subslab source-side anisotropy measurements show a general trench-normal pattern. These are associated with mantle flow through a possible ongoing tearing of the oceanic lithosphere in the area. Although the exact geometry of this slab tear is relatively unknown, SKS trench-parallel measurements imply that the tear has not reached the surface yet. Further exploration of the Hellenic subduction system is necessary; denser seismic networks should be deployed at both its edges in order to achieve

Depressurization amorphization of single-crystal boron carbide.

PubMed

Yan, X Q; Tang, Z; Zhang, L; Guo, J J; Jin, C Q; Zhang, Y; Goto, T; McCauley, J W; Chen, M W

2009-02-20

We report depressurization amorphization of single-crystal boron carbide (B4C) investigated by in situ high-pressure Raman spectroscopy. It was found that localized amorphization of B4C takes place during unloading from high pressures, and nonhydrostatic stresses play a critical role in the high-pressure phase transition. First-principles molecular dynamics simulations reveal that the depressurization amorphization results from pressure-induced irreversible bending of C-B-C atomic chains cross-linking 12 atom icosahedra at the rhombohedral vertices.

GUIDELINES FOR INSTALLATION AND SAMPLING OF SUB-SLAB VAPOR PROBES TO SUPPORT ASSESSMENT OF VAPOR INTRUSION

EPA Science Inventory

The purpose of this paper is to provide guidelines for sub-slab sampling using dedicated vapor probes. Use of dedicated vapor probes allows for multiple sample events before and after corrective action and for vacuum testing to enhance the design and monitoring of a corrective m...

ASSESSMENT OF VAPOR INTRUSION IN HOMES NEAR THE RAYMARK SUPERFUND SITE USING BASEMENT AND SUB-SLAB AIR SAMPLES

EPA Science Inventory

This report describes the results of an investigation conducted to assist EPA’s New England Regional Office in evaluating vapor intrusion at 15 homes and one commercial building near the Raymark Superfund Site in Stratford, Connecticut. Methods were developed to sample sub-slab ...

Constraints complicate centrifugal compressor depressurization

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

Key, B.; Colbert, F.L.

1993-05-10

Blowdown of a centrifugal compressor is complicated by process constraints that might require slowing the depressurization rate and by mechanical constraints for which a faster rate might be preferred. The paper describes design constraints such as gas leaks; thrust-bearing overload; system constraints; flare extinguishing; heat levels; and pressure drop.

Experimental Investigation on the Behavior of Supercritical CO2 during Reservoir Depressurization.

PubMed

Li, Rong; Jiang, Peixue; He, Di; Chen, Xue; Xu, Ruina

2017-08-01

CO 2 sequestration in saline aquifers is a promising way to address climate change. However, the pressure of the sequestration reservoir may decrease in practice, which induces CO 2 exsolution and expansion in the reservoir. In this study, we conducted a core-scale experimental investigation on the depressurization of CO 2 -containing sandstone using NMR equipment. Three different series of experiments were designed to investigate the influence of the depressurization rate and the initial CO2 states on the dynamics of different trapping mechanisms. The pressure range of the depressurization was from 10.5 to 4.0 MPa, which covered the supercritical and gaseous states of the CO 2 (named as CO 2 (sc) and CO 2 (g), respectively). It was found that when the aqueous phase saturated initially, the exsolution behavior strongly depended on the depressurization rate. When the CO 2 and aqueous phase coexisting initially, the expansion of the CO 2 (sc/g) contributed to the incremental CO 2 saturation in the core only when the CO 2 occurred as residually trapped. It indicates that the reservoir depressurization has the possibility to convert the solubility trapping to the residual trapping phase, and/or convert the residual trapping to mobile CO 2 .

Depressurization valve

DOEpatents

Skoda, G.I.

1989-03-28

A depressurization valve for use in relieving completely the pressure in a simplified boiling water reactor is disclosed. The normally closed and sealed valve is provided with a valve body defining a conduit from an outlet of a manifold from the reactor through a valve seat. A closing valve disk is configured for fitting to the valve seat to normally close the valve. The seat below the disk is provided with a radially extending annulus extending a short distance into the aperture defined by the seat. The disk is correspondingly provided with a longitudinally extending annulus that extends downwardly through the aperture defined by the seat towards the high pressure side of the valve body. A ring shaped membrane is endlessly welded to the seat annulus and to the disk annulus. The membrane is conformed over the confronted surface of the seat and disk in a C-sectioned configuration to seal the depressurization valve against the possibility of weeping. The disk is held to the closed position by an elongate stem extending away from the high pressure side of the valve body. The stem has a flange configured integrally to the stem for bias by two springs. The first spring acts from a portion of the housing overlying the disk on the stem flange adjacent the disk. This spring urges the stem and attached disk away from the seat and thus will cause the valve to open at any pressure. A second spring-preferably of the Belleville variety-acts on a latch plate surrounding and freely moving relative to the end of the stem. This second spring overcomes the bias of the first spring and any pressure acting upon the disk. This Belleville spring maintains through its spring force the valve in the closed position. At the same time, the latch plate with its freedom of movement relative to the stem allows the stem to thermally expand during valve temperature excursion.

Depressurization-induced fines migration in hydrate-bearing clayey sands: X-ray CT imaging and quantification

NASA Astrophysics Data System (ADS)

Han, G.; Kwon, T. H.; Lee, J. Y.

2016-12-01

As gas and water flows induced by depressurization of hydrate-bearing sediments exert seepage forces on fines in sediments, such as clay particles, depressurization is reported to accompany the transport of fine particles through sediment pores, i.e., fines migration. Because such fines migration can cause pore clogging, the fines migration is considered as one of the critical phenomena contributing to the transport of fluids among various pore-scale processes associated with depressurization. However, quantification of fines migration during depressurization still remains poorly understood. This study thus investigated fines migration caused by depressurization using X-ray computerized tomography(X-ray CT) imaging. A host sediment was prepared by mixing fine sand with kaolinite clay minerals to achieve 10% mass fraction of fines (less than 75 um). Then, methane hydrate was synthesized in the host clayey sand, and thereafter water was injected to saturate the hydrate-bearing sediment sample. Step-wise depressurization was applied while the produced gas was collected through an outlet fluid port. X-ray CT imaging was conducted on the sediment sample over the courses of the experiment to monitor the sample preparation, hydrate formation, depressurization, and fines migration. Based on the calibration tests, the amount and locations of methane hydrate formed in the sample was estimated, and the gas migration path was also identified. Finally, the spatial distribution of fines after completion of depressurization was first assessed using the obtained X-ray images and then compared with the post-mortem mine-back results.Notably, we found that the middle part of the sample was clogged possibly by fines or by re-formed hydrate, leading to a big pressure difference between the inlet and outlet fluid port of the sample by 3 MPa. Owing to this clogging and the lost in pressure communication, hydrate dissociation first occurred at the bottom half and the hydrate dissociation

Occurrence and attempted mitigation of carbon dioxide in a home constructed on reclaimed coal-mine spoil, Pike County, Indiana

USGS Publications Warehouse

Robinson, Bret A.

2010-01-01

In recent years carbon dioxide intrusion has become recognized as a potentially serious health threat where homes are constructed on or near reclaimed surface coal mines. When carbon dioxide invades the living space of a home, it can collect near the floor, displace the oxygen there, and produce an oxygen-deficient environment. In this investigation, several lines of inquiry were pursued to determine the environmental factors that most influence carbon dioxide intrusion at a Pike County, Ind., home where this phenomenon is known to occur. It was found that carbon dioxide intrusion events at the home are most closely tied to rapid drops in barometric pressure and rainfall. Other researchers have shown that windy conditions and periods of cold weather also can contribute to soil-gas intrusion to structures. From this, a conceptual model was developed to illustrate the influence of these four meteorological conditions. Additionally, three mitigation methods-block-wall depressurization, block-wall and sub-slab depressurization, and block-wall and sub-slab pressurization-were applied successively to the study-site home, and environmental data were collected to evaluate the effectiveness of each mitigation method. In each case, it was found that these methods did not ensure a safe environment when meteorological conditions were favorable for carbon dioxide intrusion.

Depressurization valve

DOEpatents

Skoda, George I.

1989-01-01

A depressurization valve for use in relieving completely the pressure in a simplified boiling water reactor is disclosed. The normally closed and sealed valve is provided with a valve body defining a conduit from an outlet of a manifold from the reactor through a valve seat. A closing valve disk is configured for fitting to the valve seat to normally close the valve. The seat below the disk is provided with a radially extending annulus extending a short distance into the aperture defined by the seat. The disk is correspondingly provided with a longitudinally extending annulus that extends downwardly through the aperture defined by the seat towards the high pressure side of the valve body. A ring shaped membrane is endlessly welded to the seat annulus and to the disk annulus. The membrane is conformed over the confronted surface of the seat and disk in a C-sectioned configuration to seal the depressurization valve against the possibility of weeping. The disk is held to the closed position by an elongate stem extending away from the high pressure side of the valve body. The stem has a flange configured integrally to the stem for bias by two springs. The first spring acts from a portion of the housing overlying the disk on the stem flange adjacent the disk. This spring urges the stem and attached disk away from the seat and thus will cause the valve to open at any pressure. A second spring--preferably of the Belleville variety--acts on a latch plate surrounding and freely moving relative to the end of the stem. This second spring overcomes the bias of the first spring and any pressure acting upon the disk. This Belleville spring maintains through its spring force the valve in the closed position. At the same time, the latch plate with its freedom of movement relative to the stem allows the stem to thermally expand during valve temperature excursion. The latch plate in surrounding the stem is limited in its outward movement by a boss attached to the stem at the end of

The effect of the rate of hydrostatic pressure depressurization on cells in culture.

PubMed

Tworkoski, Ellen; Glucksberg, Matthew R; Johnson, Mark

2018-01-01

Changes in hydrostatic pressure, at levels as low as 10 mm Hg, have been reported in some studies to alter cell function in vitro; however, other studies have found no detectable changes using similar methodologies. We here investigate the hypothesis that the rate of depressurization, rather than elevated hydrostatic pressure itself, may be responsible for these reported changes. Hydrostatic pressure (100 mm Hg above atmospheric pressure) was applied to bovine aortic endothelial cells (BAECs) and PC12 neuronal cells using pressurized gas for periods ranging from 3 hours to 9 days, and then the system was either slowly (~30 minutes) or rapidly (~5 seconds) depressurized. Cell viability, apoptosis, proliferation, and F-actin distribution were then assayed. Our results did not show significant differences between rapidly and slowly depressurized cells that would explain differences previously reported in the literature. Moreover, we found no detectable effect of elevated hydrostatic pressure (with slow depressurization) on any measured variables. Our results do not confirm the findings of other groups that modest increases in hydrostatic pressure affect cell function, but we are not able to explain their findings.

Performing a Launch Depressurization Test on an Inflatable Space Habitat

NASA Technical Reports Server (NTRS)

Martin, Patrick J.; Van Velzer, Paul

2014-01-01

In July, 2014 JPL's Environmental Test Laboratory successfully performed a launch depressurization test on an inflatable space habitat proposed to be installed on the International Space Station. The inflatable habitat is to be launched in the SpaceX Dragon Trunk. During the launch, the unpressurized Dragon Trunk will rapidly change from ground level atmospheric pressure to the vacuum of space. Since the inflatable habitat is tightly folded during launch with multiple layers of bladder, Kevlar fabric sections, and micro-meteoroid shielding, it was not possible to analyze or simulate how the residual air pockets would behave during the launch. If the inflatable habitat does not vent adequately and expands, it could rupture the payload bay of the launch vehicle. A launch depressurization test was chosen as the best way to qualify the inflatable habitat. When stowed, the inflatable habitat measured approximately 241 cm (95 inches) in diameter by 152 cm (60 inches) high and weighed close to 1361 kg (3,000 pounds). Two vacuum chambers connected by a large vacuum line were used to perform this test. The inflatable habitat was mounted in the smaller chamber, which was 396 cm (13 feet) in diameter and 1128 cm (37 feet) high. The larger chamber, which was 823 cm (27 feet) in diameter and 2,591 cm (85 feet) high, was rough pumped and used as a vacuum reservoir. A two stage axial type compressor and ten Stokes vacuum pumps were also used during the depressurization. Opening a butterfly valve on the vacuum line, at the smaller chamber, was manually controlled so that the smaller chamber's depressurization rate matched the launch pressure profile.

The effect of the rate of hydrostatic pressure depressurization on cells in culture

PubMed Central

Tworkoski, Ellen; Glucksberg, Matthew R.

2018-01-01

Changes in hydrostatic pressure, at levels as low as 10 mm Hg, have been reported in some studies to alter cell function in vitro; however, other studies have found no detectable changes using similar methodologies. We here investigate the hypothesis that the rate of depressurization, rather than elevated hydrostatic pressure itself, may be responsible for these reported changes. Hydrostatic pressure (100 mm Hg above atmospheric pressure) was applied to bovine aortic endothelial cells (BAECs) and PC12 neuronal cells using pressurized gas for periods ranging from 3 hours to 9 days, and then the system was either slowly (~30 minutes) or rapidly (~5 seconds) depressurized. Cell viability, apoptosis, proliferation, and F-actin distribution were then assayed. Our results did not show significant differences between rapidly and slowly depressurized cells that would explain differences previously reported in the literature. Moreover, we found no detectable effect of elevated hydrostatic pressure (with slow depressurization) on any measured variables. Our results do not confirm the findings of other groups that modest increases in hydrostatic pressure affect cell function, but we are not able to explain their findings. PMID:29315329

Depressurization and two-phase flow of water containing high levels of dissolved nitrogen gas

NASA Technical Reports Server (NTRS)

Simoneau, R. J.

1981-01-01

Depressurization of water containing various concentrations of dissolved nitrogen gas was studied. In a nonflow depressurization experiment, water with very high nitrogen content was depressurized at rates from 0.09 to 0.50 MPa per second and a metastable behavior which was a strong function of the depressurization rate was observed. Flow experiments were performed in an axisymmetric, converging diverging nozzle, a two dimensional, converging nozzle with glass sidewalls, and a sharp edge orifice. The converging diverging nozzle exhibited choked flow behavior even at nitrogen concentration levels as low as 4 percent of the saturation level. The flow rates were independent of concentration level. Flow in the two dimensional, converging, visual nozzle appeared to have a sufficient pressure drop at the throat to cause nitrogen to come out of solution, but choking occurred further downstream. The orifice flow motion pictures showed considerable oscillation downstream of the orifice and parallel to the flow. Nitrogen bubbles appeared in the flow at back pressures as high as 3.28 MPa, and the level at which bubbles were no longer visible was a function of nitrogen concentration.

Gerst depressurized Kibo for Cubesat deployment

NASA Image and Video Library

2014-08-18

ISS040-E-096126 (18 Aug. 2014) --- In the International Space Station?s Kibo laboratory, European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, depressurizes the Kibo airlock in preparation for a series of NanoRacks CubeSat miniature satellite deployments. The first two pairs of nanosatellites are scheduled for deployment on Aug. 19. The Planet Labs Dove satellites that were carried to the station aboard the Orbital Sciences Cygnus commercial cargo craft are being deployed between Aug. 19 and Aug. 25.

Gerst depressurized Kibo for Cubesat deployment

NASA Image and Video Library

2014-08-18

ISS040-E-096122 (18 Aug. 2014) --- In the International Space Station?s Kibo laboratory, European Space Agency astronaut Alexander Gerst, Expedition 40 flight engineer, depressurizes the Kibo airlock in preparation for a series of NanoRacks CubeSat miniature satellite deployments. The first two pairs of nanosatellites are scheduled for deployment on Aug. 19. The Planet Labs Dove satellites that were carried to the station aboard the Orbital Sciences Cygnus commercial cargo craft are being deployed between Aug. 19 and Aug. 25.

DSMC Simulations of Disturbance Torque to ISS During Airlock Depressurization

NASA Technical Reports Server (NTRS)

Lumpkin, F. E., III; Stewart, B. S.

2015-01-01

The primary attitude control system on the International Space Station (ISS) is part of the United States On-orbit Segment (USOS) and uses Control Moment Gyroscopes (CMG). The secondary system is part of the Russian On orbit Segment (RSOS) and uses a combination of gyroscopes and thrusters. Historically, events with significant disturbances such as the airlock depressurizations associated with extra-vehicular activity (EVA) have been performed using the RSOS attitude control system. This avoids excessive propulsive "de-saturations" of the CMGs. However, transfer of attitude control is labor intensive and requires significant propellant. Predictions employing NASA's DSMC Analysis Code (DAC) of the disturbance torque to the ISS for depressurization of the Pirs airlock on the RSOS will be presented [1]. These predictions were performed to assess the feasibility of using USOS control during these events. The ISS Pirs airlock is vented using a device known as a "T-vent" as shown in the inset in figure 1. By orienting two equal streams of gas in opposite directions, this device is intended to have no propulsive effect. However, disturbance force and torque to the ISS do occur due to plume impingement. The disturbance torque resulting from the Pirs depressurization during EVAs is estimated by using a loosely coupled CFD/DSMC technique [2]. CFD is used to simulate the flow field in the nozzle and the near field plume. DSMC is used to simulate the remaining flow field using the CFD results to create an in flow boundary to the DSMC simulation. Due to the highly continuum nature of flow field near the T-vent, two loosely coupled DSMC domains are employed. An 88.2 cubic meter inner domain contains the Pirs airlock and the T-vent. Inner domain results are used to create an in flow boundary for an outer domain containing the remaining portions of the ISS. Several orientations of the ISS solar arrays and radiators have been investigated to find cases that result in minimal

Temporary vs. Permanent Sub-slab Ports: A Comparative ...

EPA Pesticide Factsheets

Vapor intrusion (VI) is the migration of subsurface vapors, including radon and volatile organic compounds (VOCs), from the subsurface to indoor air. The VI exposure pathway extends from the contaminant source, which can be impacted soil, non-aqueous phase liquid, or contaminated groundwater, to indoor air-exposure points. Therefore, contaminated matrices may include groundwater, soil, soil gas, and indoor air. VOC contaminants of concern typically include halogenated solvents such as trichloroethene, tetrachloroethene, and chloroform, as well as petroleum hydrocarbons, such as the aromatic VOCs benzene, toluene, and xylenes. Radon is a colorless radioactive gas that is released by radioactive decay of radionuclides in rock and soil that migrate into homes through VI in a similar fashion to VOCs. This project focused on the performance of permanent versus temporary sub-slab sampling ports for the determination of VI of halogenated VOCs and radon into an unoccupied house. VOC and radon concentrations measured simultaneously in soil gas using collocated temporary and permanent ports appeared to be independent of the type of port. The variability between collocated temporary and permanent ports was much less than the spatial variability between different locations within a single residential duplex. The agreement of the majority of VOC and radon concentrations, 0–36% relative percent difference, and 2–19% relative standard deviation respectively, of each sub-sl

Physical property changes in hydrate-bearing sediment due to depressurization and subsequent repressurization

USGS Publications Warehouse

Waite, W.F.; Kneafsey, T.J.; Winters, W.J.; Mason, D.H.

2008-01-01

Physical property measurements of sediment cores containing natural gas hydrate are typically performed on material exposed, at least briefly, to non-in situ conditions during recovery. To examine the effects of a brief excursion from the gas-hydrate stability field, as can occur when pressure cores are transferred to pressurized storage vessels, we measured physical properties on laboratory-formed sand packs containing methane hydrate and methane pore gas. After depressurizing samples to atmospheric pressure, we repressurized them into the methane-hydrate stability field and remeasured their physical properties. Thermal conductivity, shear strength, acoustic compressional and shear wave amplitudes, and speeds of the original and depressurized/repressurized samples are compared. X– ray computed tomography images track how the gas-hydrate distribution changes in the hydrate-cemented sands owing to the depressurizaton/repressurization process. Because depressurization-induced property changes can be substantial and are not easily predicted, particularly in water-saturated, hydrate-bearing sediment, maintaining pressure and temperature conditions throughout the core recovery and measurement process is critical for using laboratory measurements to estimate in situ properties.

Physical property changes in hydrate-bearing sediment due to depressurization and subsequent repressurization

USGS Publications Warehouse

Waite, W.F.; Kneafsey, T.J.; Winters, W.J.; Mason, D.H.

2008-01-01

Physical property measurements of sediment cores containing natural gas hydrate are typically performed on material exposed, at least briefly, to non-in situ conditions during recovery. To examine the effects of a brief excursion from the gas-hydrate stability field, as can occur when pressure cores are transferred to pressurized storage vessels, we measured physical properties on laboratory-formed sand packs containing methane hydrate and methane pore gas. After depressurizing samples to atmospheric pressure, we repressurized them into the methane-hydrate stability field and remeasured their physical properties. Thermal conductivity, shear strength, acoustic compressional and shear wave amplitudes, and speeds of the original and depressurized/repressurized samples are compared. X-ray computed tomography images track how the gas-hydrate distribution changes in the hydrate-cemented sands owing to the depressurizaton/repressurization process. Because depressurization-induced property changes can be substantial and are not easily predicted, particularly in water-saturated, hydrate-bearing sediment, maintaining pressure and temperature conditions throughout the core recovery and measurement process is critical for using laboratory measurements to estimate in situ properties.

Crew Survivability After a Rapid Cabin Depressurization Event

NASA Technical Reports Server (NTRS)

Sargusingh, Miriam J.

2012-01-01

Anecdotal evidence acquired through historic failure investigations involving rapid cabin decompression (e.g. Challenger, Columbia and Soyuz 11) show that full evacuation of the cabin atmosphere may occur within seconds. During such an event, the delta-pressure between the sealed suit ventilation system and the cabin will rise at the rate of the cabin depressurization; potentially at a rate exceeding the capability of the suit relief valve. It is possible that permanent damage to the suit pressure enclosure and ventilation loop components may occur as the integrated system may be subjected to delta pressures in excess of the design-to pressures. Additionally, as the total pressure of the suit ventilation system decreases, so does the oxygen available to the crew. The crew may be subjected to a temporarily incapacitating, but non-lethal, hypoxic environment. It is expected that the suit will maintain a survivable atmosphere on the crew until the vehicle pressure control system recovers or the cabin has otherwise attained a habitable environment. A common finding from the aforementioned reports indicates that the crew would have had a better chance at surviving the event had they been in a protective configuration, that is, in a survival suit. Making use of these lessons learned, the Constellation Program implemented a suit loop in the spacecraft design and required that the crew be in a protective configuration, that is suited with gloves on and visors down, during dynamic phases of flight that pose the greatest risk for a rapid and uncontrolled cabin depressurization event: ascent, entry, and docking. This paper details the evaluation performed to derive suit pressure garment and ventilation system performance parameters that would lead to the highest probability of crew survivability after an uncontrolled crew cabin depressurization event while remaining in the realm of practicality for suit design. This evaluation involved: (1) assessment of stakeholder

Effect of Acute Intermittent CPAP Depressurization during Sleep in Obese Patients.

PubMed

Jun, Jonathan C; Unnikrishnan, Dileep; Schneider, Hartmut; Kirkness, Jason; Schwartz, Alan R; Smith, Philip L; Polotsky, Vsevolod Y

2016-01-01

Obstructive Sleep Apnea (OSA) describes intermittent collapse of the airway during sleep, for which continuous positive airway pressure (CPAP) is often prescribed for treatment. Prior studies suggest that discontinuation of CPAP leads to a gradual, rather than immediate return of baseline severity of OSA. The objective of this study was to determine the extent of OSA recurrence during short intervals of CPAP depressurization during sleep. Nine obese (BMI = 40.4 ± 3.5) subjects with severe OSA (AHI = 88.9 ± 6.8) adherent to CPAP were studied during one night in the sleep laboratory. Nasal CPAP was delivered at therapeutic (11.1 ± 0.6 cm H20) or atmospheric pressure, in alternating fashion for 1-hour periods during the night. We compared sleep architecture and metrics of OSA during CPAP-on and CPAP-off periods. 8/9 subjects tolerated CPAP withdrawal. The average AHI during CPAP-on and CPAP-off periods was 3.6 ± 0.6 and 15.8 ± 3.6 respectively (p<0.05). The average 3% ODI during CPAP-on and CPAP-off was 4.7 ± 2 and 20.4 ± 4.7 respectively (p<0.05). CPAP depressurization also induced more awake (p<0.05) and stage N1 (p<0.01) sleep, and less stage REM (p<0.05) with a trend towards decreased stage N3 (p = 0.064). Acute intermittent depressurization of CPAP during sleep led to deterioration of sleep architecture but only partial re-emergence of OSA. These observations suggest carryover effects of CPAP.

Effect of Acute Intermittent CPAP Depressurization during Sleep in Obese Patients

PubMed Central

Jun, Jonathan C.; Unnikrishnan, Dileep; Schneider, Hartmut; Kirkness, Jason; Schwartz, Alan R.; Smith, Philip L.; Polotsky, Vsevolod Y.

2016-01-01

Background Obstructive Sleep Apnea (OSA) describes intermittent collapse of the airway during sleep, for which continuous positive airway pressure (CPAP) is often prescribed for treatment. Prior studies suggest that discontinuation of CPAP leads to a gradual, rather than immediate return of baseline severity of OSA. The objective of this study was to determine the extent of OSA recurrence during short intervals of CPAP depressurization during sleep. Methods Nine obese (BMI = 40.4 ± 3.5) subjects with severe OSA (AHI = 88.9 ± 6.8) adherent to CPAP were studied during one night in the sleep laboratory. Nasal CPAP was delivered at therapeutic (11.1 ± 0.6 cm H20) or atmospheric pressure, in alternating fashion for 1-hour periods during the night. We compared sleep architecture and metrics of OSA during CPAP-on and CPAP-off periods. Results 8/9 subjects tolerated CPAP withdrawal. The average AHI during CPAP-on and CPAP-off periods was 3.6 ± 0.6 and 15.8 ± 3.6 respectively (p<0.05). The average 3% ODI during CPAP-on and CPAP-off was 4.7 ± 2 and 20.4 ± 4.7 respectively (p<0.05). CPAP depressurization also induced more awake (p<0.05) and stage N1 (p<0.01) sleep, and less stage REM (p<0.05) with a trend towards decreased stage N3 (p = 0.064). Conclusion Acute intermittent depressurization of CPAP during sleep led to deterioration of sleep architecture but only partial re-emergence of OSA. These observations suggest carryover effects of CPAP. PMID:26731735

Numerical Study on Wake Flow Field Characteristic of the Base-Bleed Unit under Fast Depressurization Process

NASA Astrophysics Data System (ADS)

Xue, Xiaochun; Yu, Yonggang

2017-04-01

Numerical analyses have been performed to study the influence of fast depressurization on the wake flow field of the base-bleed unit (BBU) with a secondary combustion when the base-bleed projectile is propelled out of the muzzle. Two-dimensional axisymmetric Navier-Stokes equations for a multi-component chemically reactive system is solved by Fortran program to calculate the couplings of the internal flow field and wake flow field with consideration of the combustion of the base-bleed propellant and secondary combustion effect. Based on the comparison with the experiments, the unsteady variation mechanism and secondary combustion characteristic of wake flow field under fast depressurization process is obtained numerically. The results show that in the fast depressurization process, the variation extent of the base pressure of the BBU is larger in first 0.9 ms and then decreases gradually and after 1.5 ms, it remains basically stable. The pressure and temperature of the base-bleed combustion chamber experience the decrease and pickup process. Moreover, after the pressure and temperature decrease to the lowest point, the phenomenon that the external gases are flowing back into the base-bleed combustion chamber appears. Also, with the decrease of the initial pressure, the unsteady process becomes shorter and the temperature gradient in the base-bleed combustion chamber declines under the fast depressurization process, which benefits the combustion of the base-bleed propellant.

Dissociation of Laboratory-Synthesized Methane Hydrate in Coarse-Grained Sediments by Slow Depressurization

NASA Astrophysics Data System (ADS)

Phillips, S. C.; You, K.; Borgfeldt, T.; Meyer, D.; Dong, T.; Flemings, P. B.

2016-12-01

We performed four dissociation experiments in which experimentally-formed methane hydrate was dissociated via slow, stepwise depressurization, revealing in situ salinity conditions. Overall, these results suggest the occurrence of local pore water freshening around dissociating hydrate in which bulk equilibrium behavior is limited by salt diffusion. Depressurization was performed at a constant confining temperature over 1 to 3 weeks by releasing small volumes of methane gas from the top of a vertically-oriented sample into an inverted graduated cylinder. We identify three distinct regimes of depressurization based on pressure drop behavior: (1) release of free gas down to initial hydrate dissociation at 3.3 MPa in NaBr or 4.64 MPa in NaCl, (2) dissociation of methane hydrate characterized by a slow, logarithmic increase in pressure after each gas release and (3) residual free gas release. Initial hydrate dissociation in NaCl brine at 4.64 MPa corresponds to the phase boundary for hydrate in 9.6 wt% NaCl. In the NaCl experiment, pressure increases of 0.16 MPa while the sample was shut in over 3 days likely correspond to a recovery in salinity of 0.7 wt. %. Salt ions likely diffuse from brine ahead of the hydrate front, based on a length scale for diffusion of NaCl of 6.3 cm for 3 days. In this experiment dissociation at bulk equilibrium is expected to decline from 4.54 to 4.04 MPa; however actual dissociation during 73 gas releases over 15 days, results in a pressure drop from 4.64 to 3.25 MPa. Hydrate samples were formed by injection of methane gas at 1 ºC and 12.24 MPa within a cylinder packed with medium-grained quartz sand and initially saturated in a 7 wt% NaBr or NaCl solution. In two experiments in which the system was thoroughly leak tested, total methane consumed during formation and recovered during depressurization match within 7% indicating this approach to be relatively accurate for determining total methane in experimental or pressure core samples.

Geomechanical response of permafrost-associated hydrate deposits to depressurization-induced gas production

USGS Publications Warehouse

Rutqvist, J.; Moridis, G.J.; Grover, T.; Collett, T.

2009-01-01

In this simulation study, we analyzed the geomechanical response during depressurization production from two known hydrate-bearing permafrost deposits: the Mallik (Northwest Territories, Canada) deposit and Mount Elbert (Alaska, USA) deposit. Gas was produced from these deposits at constant pressure using horizontal wells placed at the top of a hydrate layer (HL), located at a depth of about 900??m at the Mallik site and 600??m at the Mount Elbert site. The simulation results show that general thermodynamic and geomechanical responses are similar for the two sites, but with substantially higher production and more intensive geomechanical responses at the deeper Mallik deposit. The depressurization-induced dissociation begins at the well bore and then spreads laterally, mainly along the top of the HL. The depressurization results in an increased shear stress within the body of the receding hydrate and causes a vertical compaction of the reservoir. However, its effects are partially mitigated by the relatively stiff permafrost overburden, and compaction of the HL is limited to less than 0.4%. The increased shear stress may lead to shear failure in the hydrate-free zone bounded by the HL overburden and the downward-receding upper dissociation interface. This zone undergoes complete hydrate dissociation, and the cohesive strength of the sediment is low. We determined that the likelihood of shear failure depends on the initial stress state as well as on the geomechanical properties of the reservoir. The Poisson's ratio of the hydrate-bearing formation is a particularly important parameter that determines whether the evolution of the reservoir stresses will increase or decrease the likelihood of shear failure.

Rapid depressurization event analysis in BWR/6 using RELAP5 and contain

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

Mueftueoglu, A.K.; Feltus, M.A.

1995-09-01

Noncondensable gases may become dissolved in Boiling Water Reactor (BWR) water level instrumentation during normal operations. Any dissolved noncondensable gases inside these water columns may come out of solution during rapid depressurization events, and displace water from the reference leg piping resulting in a false high level. These water level errors may cause a delay or failure in actuation, or premature shutdown of the Emergency Core Cooling System. (ECCS). If a rapid depressurization causes an erroneously high water level, preventing automatic ECCS actuation, it becomes important to determine if there would be other adequate indications for operator response and othermore » signals for automatic actuation such as high drywell pressure. It is also important to determine the effect of the level signal on ECCS operation after it is being actuated. The objective of this study is to determine the detailed coupled containment/NSSS response during this rapid depressurization events in BWR/6. The selected scenarios involve: (a) inadvertent opening of all ADS valves, (b) design basis (DB) large break loss of coolant accident (LOCA), and (c) main steam line break (MSLB). The transient behaviors are evaluated in terms of: (a) vessel pressure and collapsed water level response, (b) specific transient boundary conditions, (e.g., scram, MSIV closure timing, feedwater flow, and break blowdown rates), (c) ECCS initiation timing, (d) impact of operator actions, (e) whether indications besides low-low water level were available. The results of the analysis had shown that there would be signals to actuate ECCS other than low reactor level, such as high drywell pressure, low vessel pressure, high suppression pool temperature, and that the plant operators would have significant indications to actuate ECCS.« less

Investigation of sub-slab pressure field extension in specified granular fill materials incorporating a sump-based soil depressurisation system for radon mitigation.

PubMed

Hung, Le Chi; Goggins, Jamie; Fuente, Marta; Foley, Mark

2018-05-14

Design of bearing layers (granular fill material layers) is important for a house with a soil depressurisation (SD) system for indoor radon mitigation. These layers should not only satisfy the bearing capacity and serviceability criteria but should also provide a sufficient degree of the air permeability for the system. Previous studies have shown that a critical parameter for a SD system is the sub-slab pressure field extension in the bearing layers, but this issue has not been systematically investigated. A series of two-dimensional computational fluid dynamic simulations that investigate the behaviour of the sub-slab pressure field extension developed in a SD system is presented in this paper. The SD system considered in this paper consists of a granular fill material layer and a radon sump. The granular fill materials are 'T1 Struc' and 'T2 Perm', which are standard materials for building in the Republic of Ireland. Different conditions, which might be encountered in a practical situation, were examined. The results show that the air permeability and thickness of the granular fill materials are the two key factors which affect the sub slab pressure field extension (SPFE) significantly. Furthermore, the air permeability of native soil is found to be a fundamental factor for the SPFE so that it should be well understood when designing a SD system. Therefore, these factors should be considered sufficiently in each practical situation. Finally, a significant improvement of the pressure field extension can be achieved by ensuring air tightness of the SD system. Copyright © 2018 Elsevier B.V. All rights reserved.

Radon mitigation in cold climates at Kitigan Zibi Anishinabeg.

PubMed

Brossard, Mathieu; Ottawa, Céline Brazeau; Falcomer, Renato; Whyte, Jeff

2015-02-01

Available radon mitigation results were gathered for 85 houses mainly by installing sub-slab depressurization systems (SSDS) with two types of discharge and fan locations: Above ground level discharge with the fan located in the basement (AGL) or above roof line discharge with the fan located in the attic (ARL). A comparative analysis was made of mitigation efficiency and of exhaust icing. Results show that both SSDS scenarios reduced radon levels similarly. The results of SSDS with AGL show that a sealed radon fan having proper fittings and sealed piping was able to reduce the radon to acceptable levels, and that these installations were less subject to obstructive icing of the exhaust in cold climates.

Characterization of pore structure in cement-based materials using pressurization-depressurization cycling mercury intrusion porosimetry (PDC-MIP)

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

Zhou Jian, E-mail: Jian.Zhou@tudelft.n; Ye Guang, E-mail: g.ye@tudelft.n; Magnel Laboratory for Concrete Research, Department of Structural Engineering, Ghent University, Technologiepark-Zwijnaarde 904 B-9052, Ghent

2010-07-15

Numerous mercury intrusion porosimetry (MIP) studies have been carried out to investigate the pore structure in cement-based materials. However, the standard MIP often results in an underestimation of large pores and an overestimation of small pores because of its intrinsic limitation. In this paper, an innovative MIP method is developed in order to provide a more accurate estimation of pore size distribution. The new MIP measurements are conducted following a unique mercury intrusion procedure, in which the applied pressure is increased from the minimum to the maximum by repeating pressurization-depressurization cycles instead of a continuous pressurization followed by a continuousmore » depressurization. Accordingly, this method is called pressurization-depressurization cycling MIP (PDC-MIP). By following the PDC-MIP testing sequence, the volumes of the throat pores and the corresponding ink-bottle pores can be determined at every pore size. These values are used to calculate pore size distribution by using the newly developed analysis method. This paper presents an application of PDC-MIP on the investigation of the pore size distribution in cement-based materials. The experimental results of PDC-MIP are compared with those measured by standard MIP. The PDC-MIP is further validated with the other experimental methods and numerical tool, including nitrogen sorption, backscanning electron (BSE) image analysis, Wood's metal intrusion porosimetry (WMIP) and the numerical simulation by the cement hydration model HYMOSTRUC3D.« less

Mathematical simulation of the drying of suspensions and colloidal solutions by their depressurization

NASA Astrophysics Data System (ADS)

Lashkov, V. A.; Levashko, E. I.; Safin, R. G.

2006-05-01

The heat and mass transfer in the process of drying of high-humidity materials by their depressurization has been investigated. The results of experimental investigation and mathematical simulation of the indicated process are presented. They allow one to determine the regularities of this process and predict the quality of the finished product. A technological scheme and an engineering procedure for calculating the drying of the liquid base of a soap are presented.

Numerical modeling of the waves evolution generated by the depressurization of the vessels containing a supercritical parameters coolant

NASA Astrophysics Data System (ADS)

Alekseev, Maksim V.; Vozhakov, Ivan S.; Lezhnin, Sergey I.; Pribaturin, Nikolay A.

2017-10-01

The development of power plants focuses on increasing the parameters of water coolants up to a supercritical level. Depressurization of the unit circuits with such a coolant leads to emergency situations. Their scenarios can change significantly with the variation of initial pressure and temperature before the start of depressurization. When the pressure drops from the supercritical single-phase region of the initial thermodynamic parameters of the coolant, either the liquid boils up, or the vapor is condensed. Because of the rapid pressure decrease, the phase transition can be non-equilibrium that must be taken into account in the simulation. In the present study, an axisymmetric problem of the outflow of a water coolant from the pipe butt-end is considered. The equations of continuity, momentum and energy for a two-phase homogeneous mixture are solved numerically. The vapor and liquid properties are calculated using the TTSE software package (The Tabular Taylor Series Expansion Method). On the basis of the computer complex LCPFCT (The Flux-Corrected Transport Algorithm) the program code was developed for solving numerous problems on the depressurization of vessels or pipelines, containing superheated water or gas under high pressure. Different variants of outflow in the external model atmosphere and generation of waves are analyzed. The calculated data on the interaction of pressure waves with a barrier are calculated. To describe phase transitions, an asymptotic relaxation model of nonequilibrium evaporation and condensation has been created and tested.

Summary on the depressurization from supercritical pressure conditions

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

Anderson, M.; Chen, Y.; Ammirable, L.

model [3], and the Henry-Fauske non-equilibrium model [4], and are currently used in subcritical pressure reactor safety design[5]. It appears that some of these models could be reasonably extended to above the thermodynamic pseudo-critical point. The more stable and lower discharge flow rates observed in conditions above the pseudo-critical point suggests that even though SCWR's have a smaller coolant inventory, the safety implications of a LOCA and the subsequent depressurization may not be as severe as expected, this however needs to be confirmed by a rigorous evaluation of the particular event and further evaluation of the critical flow rate. This paper will summarize activities on critical flow models, experimental data and numerical modeling during blowdown from supercritical pressure conditions under the International Atomic Energy Agency (IAEA) Coordinated Research Project (CRP) on 'Heat Transfer Behaviour and Thermo-hydraulics Code testing for SCWRs'. (authors)« less

Experimental and Numerical Observations of Hydrate Reformation during Depressurization in a Core-Scale Reactor

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

Seol, Yongkoo; Myshakin, Evgeniy

2011-01-01

Gas hydrate has been predicted to reform around a wellbore during depressurization-based gas production from gas hydrate-bearing reservoirs. This process has an adverse effect on gas production rates and it requires time and sometimes special measures to resume gas flow to producing wells. Due to lack of applicable field data, laboratory scale experiments remain a valuable source of information to study hydrate reformation. In this work, we report laboratory experiments and complementary numerical simulations executed to investigate the hydrate reformation phenomenon. Gas production from a pressure vessel filled with hydrate-bearing sand was induced by depressurization with and without heat fluxmore » through the boundaries. Hydrate decomposition was monitored with a medical X-ray CT scanner and pressure and temperature measurements. CT images of the hydrate-bearing sample were processed to provide 3-dimensional data of heterogeneous porosity and phase saturations suitable for numerical simulations. In the experiments, gas hydrate reformation was observed only in the case of no-heat supply from surroundings, a finding consistent with numerical simulation. By allowing gas production on either side of the core, numerical simulations showed that initial hydrate distribution patterns affect gas distribution and flow inside the sample. This is a direct consequence of the heterogeneous pore network resulting in varying hydraulic properties of the hydrate-bearing sediment.« less

Numerical simulations of sand production in interbedded hydrate-bearing sediments during depressurization

USGS Publications Warehouse

Uchida, Shun; Lin, Jeen-Shang; Myshakin, Evgeniy; Seol, Yongkoo; Collett, Timothy S.; Boswell, Ray

2017-01-01

Geomechanical behavior of hydrate-bearing sediments during gas production is complex, involving changes in hydrate-dependent mechanical properties. When interbedded clay layers are present, the complexity is more pronounced because hydrate dissociation tends to occur preferentially in the sediments adjacent to the clay layers due to clay layers acting as a heat source. This would potentially lead to shearing deformation along the sand/clay contacts and may contribute to solid migration, which hindered past field-scale gas production tests. This paper presents a near-wellbore simulation of sand/clay interbedded hydrate-bearing sediments that have been subjected to depressurization and discusses the effect of clay layers on sand production.

Droplet Impact on a Heated Surface under a Depressurized Environment

NASA Astrophysics Data System (ADS)

Hatakenaka, Ryuta; Tagawa, Yoshiyuki

2016-11-01

Behavior of a water droplet of the diameter 1-3mm impacting on a heated surface under depressurized environment (100kPa -1kPa) has been studied. A syringe pump for droplet generation and a heated plate are set into a transparent acrylic vacuum chamber. The internal pressure of the chamber is automatically controlled at a target pressure with a rotary pump, a pressure transducer, and an electrical valve. A silicon wafer of the thickness 0.28 mm is mounted on the heater plate, whose temperature is directly measured by attaching a thermocouple on the backside. The droplet behavior is captured using a high-speed camera in a direction perpendicular to droplet velocity. Some unique behaviors of droplet are observed by decreasing the environmental pressure, which are considered to be due to two basic elements: Enhancement of evaporation due to the lowered saturation temperature, and shortage of pneumatic spring effect between the droplet and heated wall due to the lowered pressure of the air.

Source Test Report for the 205 Delayed Coking Unit Drum 205-1201 and Drum 205-1202 Depressurization Vents (Marathon Petroleum Company LLC)

EPA Pesticide Factsheets

The 2010 Source Test was performed during the atmospheric depressurization step of the delayed coking process prior to the removal of petroleum coke from the coke drum. The 205 DCU was operated under a variety of conditions during the 2010 Source Test.

Biomedical study on combined effects of simulated weightlessness and emergent depressurization of spacecraft

NASA Astrophysics Data System (ADS)

Yang, T. D.; Zhang, R. G.; Wang, C. M.; Fu, H. W.; Zhang, B. L.; Zhang, J. X.

1999-01-01

Cabin emergent depressurization (CED) may occur in spacecraft during manned space flight. The purpose of this paper was to study the combined effects of simulated weightlessness (SW) and CED factors on humans and animals. It was found that the amplitude of T wave of human electrocardiograms (ECG) significantly decreased in bed rest and hypoxia compared with the control condition (P<0.05), and that suspension with pure O2 induced severer edema in the lungs of rats than that in only a pure O2 environment. SW and pure O2 caused middle ear congestion and decreased the barofunction during pressure changes. These results indicate that human response to CED factors become more serious under SW because of the blood redistribution.

Numerical studies of depressurization-induced gas production from an interbedded marine turbidite gas hydrate reservoir model

USGS Publications Warehouse

Myshakin, Evgeniy; Lin, Jeen-Shang; Uchida, Shun; Seol, Yongkoo; Collett, Timothy S.; Boswell, Ray

2017-01-01

The numerical simulation of thin hydrate-bearing sand layers interbedded with mud layers is investigated. In this model, the lowest hydrate layer occurs at the base of gas hydrate stability and overlies a thinly-interbedded saline aquifer. The predicted gas rates reach 6.25 MMscf/day (1.77 x 105 m3 /day) after 90 days of continuous depressurization with manageable water production. Development of horizontal dissociating interfaces between hydrate-bearing sand and mud layers is a primary determinant of reservoir performance. A set of simulations has been executed to assess uncertainty in in situ permeability and to determine the impact of the saline aquifer on productivity.

HANDBOOK: SUB-SLAB DEPRESSURIZATION FOR LOW PERMEABILITY FILL MATERIAL DESIGN AND INSTALLATION OF A HOME RADON REDUCTION SYSTEM

EPA Science Inventory

Radon, a radioactive gas, comes from the natural decay of uranium. It moves to the earth's surface through tiny openings and cracks in soil and rocks. In outdoor air, radon is diluted to such low concentrations that it is usually nothing to worry about. However, radon can accumul...

Forward osmosis as an approach to manage oil sands tailings water and on-site basal depressurization water.

PubMed

Zhu, Shu; Li, Mingyu; Gamal El-Din, Mohamed

2017-04-05

As the volume of oil sands process-affected water (OSPW) stored in tailings ponds increases, it is urgent to seek for water management approaches to alleviate the environmental impact caused by large quantity of toxic water. Forward osmosis (FO) utilizes osmotic pressure difference between two solutions, thereby giving a potential to manage two wastewaters. In this study, FO was proposed to manage OSPW, using on-site waste basal depressurization water (BDW) as draw solution. To investigate its feasibility, both short and long-term OSPW desalination experiments were carried out. By applying this process, the volume of OSPW was decreased>40% and high rejections were achieved, especially, the major organic toxicity source - naphthenic acids (NAs). Although comparative low water flux (≤3L/m 2 h) was obtained, water flux caused by membrane fouling can be completely recovered using water physical cleaning. Moreover, calcium carbonate precipitation was observed on the OSPW-oriented membrane side. With respect to flux decline, the active layer facing the feed solution (FO mode) and active layer facing draw solution (PRO mode) did not demonstrate a significant difference on anti-fouling performance. The advantages provided by this approach include zero draw solution cost, less reversible membrane fouling and beneficial reuse/recycle of diluted BDW. Copyright © 2016 Elsevier B.V. All rights reserved.

Physical modelling of LNG rollover in a depressurized container filled with water

NASA Astrophysics Data System (ADS)

Maksim, Dadonau; Denissenko, Petr; Hubert, Antoine; Dembele, Siaka; Wen, Jennifer

2015-11-01

Stable density stratification of multi-component Liquefied Natural Gas causes it to form distinct layers, with upper layer having a higher fraction of the lighter components. Heat flux through the walls and base of the container results in buoyancy-driven convection accompanied by heat and mass transfer between the layers. The equilibration of densities of the top and bottom layers, normally caused by the preferential evaporation of Nitrogen, may induce an imbalance in the system and trigger a rapid mixing process, so-called rollover. Numerical simulation of the rollover is complicated and codes require validation. Physical modelling of the phenomenon has been performed in a water-filled depressurized vessel. Reducing gas pressure in the container to levels comparable to the hydrostatic pressure in the water column allows modelling of tens of meters industrial reservoirs using a 20 cm laboratory setup. Additionally, it allows to model superheating of the base fluid layer at temperatures close the room temperature. Flow visualizations and parametric studies are presented. Results are related to outcomes of numerical modelling.

Hydro-geomechanical behaviour of gas-hydrate bearing soils during gas production through depressurization and CO2 injection

NASA Astrophysics Data System (ADS)

Deusner, C.; Gupta, S.; Kossel, E.; Bigalke, N.; Haeckel, M.

2015-12-01

Results from recent field trials suggest that natural gas could be produced from marine gas hydrate reservoirs at compatible yields and rates. It appears, from a current perspective, that gas production would essentially be based on depressurization and, when facing suitable conditions, be assisted by local thermal stimulation or gas hydrate conversion after injection of CO2-rich fluids. Both field trials, onshore in the Alaska permafrost and in the Nankai Trough offshore Japan, were accompanied by different technical issues, the most striking problems resulting from un-predicted geomechanical behaviour, sediment destabilization and catastrophic sand production. So far, there is a lack of experimental data which could help to understand relevant mechanisms and triggers for potential soil failure in gas hydrate production, to guide model development for simulation of soil behaviour in large-scale production, and to identify processes which drive or, further, mitigate sand production. We use high-pressure flow-through systems in combination with different online and in situ monitoring tools (e.g. Raman microscopy, MRI) to simulate relevant gas hydrate production scenarios. Key components for soil mechanical studies are triaxial systems with ERT (Electric resistivity tomography) and high-resolution local strain analysis. Sand production control and management is studied in a novel hollow-cylinder-type triaxial setup with a miniaturized borehole which allows fluid and particle transport at different fluid injection and flow conditions. Further, the development of a large-scale high-pressure flow-through triaxial test system equipped with μ-CT is ongoing. We will present results from high-pressure flow-through experiments on gas production through depressurization and injection of CO2-rich fluids. Experimental data are used to develop and parametrize numerical models which can simulate coupled process dynamics during gas-hydrate formation and gas production.

A simple method for environmental cell depressurization for use with an electron microscope.

PubMed

Ogawa, Naoki; Mizokawa, Ryo; Saito, Minoru; Ishikawa, Akira

2017-12-01

With the aid of the environmental cell (EC) in electron microscopy, hydrated specimens have been observed at high resolutions that optical microscopy cannot attain. Due to the ultra-high vacuum conditions of the inner column of the electron microscope, the EC requires sealing films that are sufficiently thin to allow electron transmission and that are sufficiently tough to withstand the pressure difference between the inside and outside of the EC. However, most hydrated specimens can be observed at low vacuum because the saturated vapor pressure of water is known to be 0.02 atm at room temperature. These concepts have been used in the differential pumping system, but it is complicated and relatively expensive. In this work, we propose a simple method for depressurization of the EC using a 'balloon structure' and demonstrate the theoretical benefits and practical improvement for specimen observations in low-vacuum conditions. © The Author 2017. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Enzymatic hydrolysis of chitin pretreated by rapid depressurization from supercritical 1,1,1,2-tetrafluoroethane toward highly acetylated oligosaccharides.

PubMed

Villa-Lerma, Guadalupe; González-Márquez, Humberto; Gimeno, Miquel; Trombotto, Stéphane; David, Laurent; Ifuku, Shinsuke; Shirai, Keiko

2016-06-01

The hydrolysis of chitin treated under supercritical conditions was successfully carried out using chitinases obtained by an optimized fermentation of the fungus Lecanicillium lecanii. The biopolymer was subjected to a pretreatment based on suspension in supercritical 1,1,1,2-tetrafluoroethane (scR134a), which possesses a critical temperature and pressure of 101°C and 40bar, respectively, followed by rapid depressurization to atmospheric pressure and further fibrillation. This methodology was compared to control untreated chitins and chitin subjected to steam explosion showing improved production of reducing sugars (0.18mg/mL), enzymatic hydrolysis and high acetylation (FA of 0.45) in products with degrees of polymerization between 2 and 5. Copyright © 2016 Elsevier Ltd. All rights reserved.

Extinguishment of a Diffusion Flame Over a PMMA Cylinder by Depressurization in Reduced-Gravity

NASA Technical Reports Server (NTRS)

Goldmeer, Jeffrey Scott

1996-01-01

Extinction of a diffusion flame burning over horizontal PMMA (Polymethyl methacrylate) cylinders in low-gravity was examined experimentally and via numerical simulations. Low-gravity conditions were obtained using the NASA Lewis Research Center's reduced-gravity aircraft. The effects of velocity and pressure on the visible flame were examined. The flammability of the burning solid was examined as a function of pressure and the solid-phase centerline temperature. As the solid temperature increased, the extinction pressure decreased, and with a centerline temperature of 525 K, the flame was sustained to 0.1 atmospheres before extinguishing. The numerical simulation iteratively coupled a two-dimensional quasi-steady, gas-phase model with a transient solid-phase model which included conductive heat transfer and surface regression. This model employed an energy balance at the gas/solid interface that included the energy conducted by the gas-phase to the gas/solid interface, Arrhenius pyrolysis kinetics, surface radiation, and the energy conducted into the solid. The ratio of the solid and gas-phase conductive fluxes Phi was a boundary condition for the gas-phase model at the solid-surface. Initial simulations modeled conditions similar to the low-gravity experiments and predicted low-pressure extinction limits consistent with the experimental limits. Other simulations examined the effects of velocity, depressurization rate and Phi on extinction.

Impact of ventilation systems and energy savings in a building on the mechanisms governing the indoor radon activity concentration.

PubMed

Collignan, Bernard; Powaga, Emilie

2017-11-23

For a given radon potential in the ground and a given building, the parameters affecting the indoor radon activity concentration (IRnAC) are indoor depressurization of a building and its air change rate. These parameters depend mainly on the building characteristics, such as airtightness, and on the nature and performances of the ventilation system. This study involves a numerical sensitivity assessment of the indoor environmental conditions on the IRnAC in buildings. A numerical ventilation model has been adapted to take into account the effects of variations in the indoor environmental conditions (depressurization and air change rate) on the radon entry rate and on the IRnAC. In the context of the development of a policy to reduce energy consumption in a building, the results obtained showed that IRnAC could be strongly affected by variations in the air permeability of the building associated with the ventilation regime. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion.

PubMed

Wilson, Jordan L; Samaranayake, V A; Limmer, Matt A; Burken, Joel G

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman's correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with minimal

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion

USGS Publications Warehouse

Wilson, Jordan L.; Samaranayake, V.A.; Limmer, Matthew A.; Burken, Joel G.

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman’s correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with

Phytoforensics: Trees as bioindicators of potential indoor exposure via vapor intrusion

PubMed Central

2018-01-01

Human exposure to volatile organic compounds (VOCs) via vapor intrusion (VI) is an emerging public health concern with notable detrimental impacts on public health. Phytoforensics, plant sampling to semi-quantitatively delineate subsurface contamination, provides a potential non-invasive screening approach to detect VI potential, and plant sampling is effective and also time- and cost-efficient. Existing VI assessment methods are time- and resource-intensive, invasive, and require access into residential and commercial buildings to drill holes through basement slabs to install sampling ports or require substantial equipment to install groundwater or soil vapor sampling outside the home. Tree-core samples collected in 2 days at the PCE Southeast Contamination Site in York, Nebraska were analyzed for tetrachloroethene (PCE) and results demonstrated positive correlations with groundwater, soil, soil-gas, sub-slab, and indoor-air samples collected over a 2-year period. Because tree-core samples were not collocated with other samples, interpolated surfaces of PCE concentrations were estimated so that comparisons could be made between pairs of data. Results indicate moderate to high correlation with average indoor-air and sub-slab PCE concentrations over long periods of time (months to years) to an interpolated tree-core PCE concentration surface, with Spearman’s correlation coefficients (ρ) ranging from 0.31 to 0.53 that are comparable to the pairwise correlation between sub-slab and indoor-air PCE concentrations (ρ = 0.55, n = 89). Strong correlations between soil-gas, sub-slab, and indoor-air PCE concentrations and an interpolated tree-core PCE concentration surface indicate that trees are valid indicators of potential VI and human exposure to subsurface environment pollutants. The rapid and non-invasive nature of tree sampling are notable advantages: even with less than 60 trees in the vicinity of the source area, roughly 12 hours of tree-core sampling with

Nuclear reactor with makeup water assist from residual heat removal system

DOEpatents

Corletti, Michael M.; Schulz, Terry L.

1993-01-01

A pressurized water nuclear reactor uses its residual heat removal system to make up water in the reactor coolant circuit from an in-containment refueling water supply during staged depressurization leading up to passive emergency cooling by gravity feed from the refueling water storage tank, and flooding of the containment building. When depressurization commences due to inadvertence or a manageable leak, the residual heat removal system is activated manually and prevents flooding of the containment when such action is not necessary. Operation of the passive cooling system is not impaired. A high pressure makeup water storage tank is coupled to the reactor coolant circuit, holding makeup coolant at the operational pressure of the reactor. The staged depressurization system vents the coolant circuit to the containment, thus reducing the supply of makeup coolant. The level of makeup coolant can be sensed to trigger opening of successive depressurization conduits. The residual heat removal pumps move water from the refueling water storage tank into the coolant circuit as the coolant circuit is depressurized, preventing reaching the final depressurization stage unless the makeup coolant level continues to drop. The residual heat removal system can also be coupled in a loop with the refueling water supply tank, for an auxiliary heat removal path.

Nuclear reactor with makeup water assist from residual heat removal system

DOEpatents

Corletti, M.M.; Schulz, T.L.

1993-12-07

A pressurized water nuclear reactor uses its residual heat removal system to make up water in the reactor coolant circuit from an in-containment refueling water supply during staged depressurization leading up to passive emergency cooling by gravity feed from the refueling water storage tank, and flooding of the containment building. When depressurization commences due to inadvertence or a manageable leak, the residual heat removal system is activated manually and prevents flooding of the containment when such action is not necessary. Operation of the passive cooling system is not impaired. A high pressure makeup water storage tank is coupled to the reactor coolant circuit, holding makeup coolant at the operational pressure of the reactor. The staged depressurization system vents the coolant circuit to the containment, thus reducing the supply of makeup coolant. The level of makeup coolant can be sensed to trigger opening of successive depressurization conduits. The residual heat removal pumps move water from the refueling water storage tank into the coolant circuit as the coolant circuit is depressurized, preventing reaching the final depressurization stage unless the makeup coolant level continues to drop. The residual heat removal system can also be coupled in a loop with the refueling water supply tank, for an auxiliary heat removal path. 2 figures.

Facies-controlled fluid migration patterns and subsequent reservoir collapse by depressurization - the Entrada Sandstone, Utah

NASA Astrophysics Data System (ADS)

Sundal, A.; Skurtveit, E.; Midtkandal, I.; Hope, I.; Larsen, E.; Kristensen, R. S.; Braathen, A.

2016-12-01

The thick and laterally extensive Middle Jurassic Entrada Sandstone forms a regionally significant reservoir both in the subsurface and as outcrops in Utah. Individual layers of fluvial sandstone within otherwise fine-grained aeolian dunes and silty inter-dune deposits of the Entrada Earthy Member are of particular interest as CO2 reservoir analogs to study injectivity, reservoir-caprock interaction and bypass systems. Detailed mapping of facies and deformation structures, including petrographic studies and core plug tests, show significant rock property contrasts between layers of different sedimentary facies. Beds representing fluvial facies appear as white, medium-grained, well-sorted and cross-stratified sandstone, displaying high porosity, high micro-scale permeability, low tensile strength, and low seismic velocity. Subsequent to deposition, these beds were structurally deformed and contain a dense network of deformation bands, especially in proximity to faults and injectites. Over- and underlying low-permeability layers of inter-dune aeolian facies contain none or few deformation bands, display significantly higher rock strengths and high seismic velocities compared to the fluvial inter-beds. Permeable units between low-permeability layers are prone to become over-pressured during burial, and the establishment of fluid escape routes during regional tectonic events may have caused depressurization and selective collapse of weak layers. Through-cutting, vertical sand pipes display large clasts of stratified sandstone suspended in remobilized sand matrix, and may have served as permeable fluid conduits and pressure vents before becoming preferentially cemented and plugged. Bleached zones around faults and fractures throughout the succession indicate leakage and migration of reducing fluids. The fluvial beds are porous and would appear in wireline logs and seismic profiles as excellent reservoirs; whereas due to dense populations of deformation bands they may in

KENNEDY SPACE CENTER, FLA. - A worker in the Orbiter Processing Facility checks the open hatch of the airlock in Discovery’s payload bay. The airlock is normally located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

NASA Image and Video Library

2004-01-22

KENNEDY SPACE CENTER, FLA. - A worker in the Orbiter Processing Facility checks the open hatch of the airlock in Discovery’s payload bay. The airlock is normally located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

Experimental study of effectiveness of four radon mitigation solutions, based on underground depressurization, tested in prototype housing built in a high radon area in Spain.

PubMed

Frutos Vázquez, Borja; Olaya Adán, Manuel; Quindós Poncela, Luis Santiago; Sainz Fernandez, Carlos; Fuente Merino, Ismael

2011-04-01

The present paper discusses the results of an empirical study of four approaches to reducing indoor radon concentrations based on depressurization techniques in underground sumps. The experiments were conducted in prototype housing built in an area of Spain where the average radon concentration at a depth of 1 m is 250 kBq m(-3). Sump effectiveness was analysed in two locations: underneath the basement, which involved cutting openings into the foundation, ground storey and roof slabs, and outside the basement walls, which entailed digging a pit alongside the building exterior. The effectiveness of both sumps was likewise tested with passive and forced ventilation methods. The systems proved to be highly efficient, lowering radon levels by 91-99%, except in the solution involving passive ventilation and the outside sump, where radon levels were reduced by 53-55%. At wind speeds of over 8 m/s, however, passive ventilation across an outside sump lowered radon levels by 95% due to a Venturi effect induced drop in pressure. Copyright © 2011 Elsevier Ltd. All rights reserved.

A research program to reduce interior noise in general aviation airplanes. Influence of depressurization and damping material on the noise reduction characteristics of flat and curved stiffened panels

NASA Technical Reports Server (NTRS)

Navaneethan, R.; Streeter, B.; Koontz, S.; Roskam, J.

1981-01-01

Some 20 x 20 aluminum panels were studied in a frequency range from 20 Hz to 5000 Hz. The noise sources used were a swept sine wave generator and a random noise generator. The effect of noise source was found to be negligible. Increasing the pressure differential across the panel gave better noise reduction below the fundamental resonance frequency due to an increase in stiffness. The largest increase occurred in the first 1 psi pressure differential. The curved, stiffened panel exhibited similar behavior, but with a lower increase of low frequency noise reduction. Depressurization on these panels resulted in decreased noise reduction at higher frequencies. The effect of damping tapes on the overall noise reduction values of the test specimens was small away from the resonance frequency. In the mass-law region, a slight and proportional improvement in noise reduction was observed by adding damping material. Adding sound absorbtion material to a panel with damping material beneficially increased noise reduction at high frequencies.

KENNEDY SPACE CENTER, FLA. - Seen in the photo is one end of the airlock that is installed in the payload bay of orbiter Discovery. The airlock is normally located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

NASA Image and Video Library

2004-01-22

KENNEDY SPACE CENTER, FLA. - Seen in the photo is one end of the airlock that is installed in the payload bay of orbiter Discovery. The airlock is normally located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

Synthesis of fructooligosaccharides from Aspergillus niger commercial inulinase immobilized in montmorillonite pretreated in pressurized propane and LPG.

PubMed

de Oliveira Kuhn, Graciele; Rosa, Clarissa Dalla; Silva, Marceli Fernandes; Treichel, Helen; de Oliveira, Débora; Oliveira, J Vladimir

2013-02-01

Commercial inulinase from Aspergillus niger was immobilized in montmorillonite and then treated in pressurized propane and liquefied petroleum gas (LPG). Firstly, the effects of system pressure, exposure time, and depressurization rate, using propane and LPG, on enzymatic activity were evaluated through central composite design 2³. Residual activities of 145.1 and 148.5% were observed for LPG (30 bar, 6 h, and depressurization rate of 20 bar min⁻¹) and propane (270 bar, 1 h, and depressurization rate of 100 bar min⁻¹), respectively. The catalysts treated at these conditions in both fluids were then used for the production of fructooligosaccharides (FOS) using sucrose and inulin as substrates in aqueous and organic systems. The main objective of this step was to evaluate the yield and productivity in FOS, using alternatives for enhancing enzyme activity by means of pressurized fluids and also using low-cost supports for enzyme immobilization, aiming at obtaining a stable biocatalyst to be used for synthesis reactions. Yields of 18% were achieved using sucrose as substrate in aqueous medium, showing the potential of this procedure, hence suggesting a further optimization step to increase the process yield.

March 2017 Grenada Manufacturing, LLC Data Validation Reports and Analytical Laboratory Reports for the Main Plant Building Vapor Intrusion Sampling

EPA Pesticide Factsheets

Data Validation Reports and Full Analytical Lab Reports for Indoor Air, Ambient Air and Sub-slab samples taken during the facility vapor intrusion investigation in March 2017 at the Grenada Manufacturing plant

The effect of exercise and rest duration on the generation of venous gas bubbles at altitude

NASA Technical Reports Server (NTRS)

Dervay, Joseph P.; Powell, Michael R.; Butler, Bruce; Fife, Caroline E.

2002-01-01

BACKGROUND: Decompression, as occurs with aviators and astronauts undergoing high altitude operations or with deep-sea divers returning to surface, can cause gas bubbles to form within the organism. Pressure changes to evoke bubble formation in vivo during depressurization are several orders of magnitude less than those required for gas phase formation in vitro in quiescent liquids. Preformed micronuclei acting as "seeds" have been proposed, dating back to the 1940's. These tissue gas micronuclei have been attributed to a minute gas phase located in hydrophobic cavities, surfactant-stabilized microbubbles, or arising from musculoskeletal activity. The lifetimes of these micronuclei have been presumed to be from a few minutes to several weeks. HYPOTHESIS: The greatest incidence of venous gas emboli (VGE) will be detected by precordial Doppler ultrasound with depressurization immediately following lower extremity exercise, with progressively reduced levels of VGE observed as the interval from exercise to depressurization lengthens. METHODS: In a blinded cross-over design, 20 individuals (15 men, 5 women) at sea level exercised by performing knee-bend squats (150 knee flexes over 10 min, 235-kcal x h(-1)) either at the beginning, middle, or end of a 2-h chair-rest period without an oxygen prebreathe. Seated subjects were then depressurized to 6.2 psia (6,706 m or 22,000 ft altitude equivalent) for 120 min with no exercise performed at altitude. RESULTS: Of the 20 subjects with VGE in the pulmonary artery, 10 demonstrated a greater incidence of bubbles with exercise performed just prior to depressurization, compared with decreasing bubble grades and incidence as the interval of rest increased prior to depressurization. No decompression illness was reported. CONCLUSIONS: There is a significant increase in decompression-induced bubble formation at 6.2 psia when lower extremity exercise is performed just prior to depressurization as compared with longer rest intervals

76 FR 71342 - Proposed CERCLA Administrative Cost Recovery Settlement; River Forest Dry Cleaners Site, River...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-17

.... After EPA received an email from a concerned teacher, U.S. EPA conducted indoor air and sub-slab samples... indicate any level of contamination that warranted a removal action. The removal assessment was completed...

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, a cameraman films part of Discovery’s payload bay for a special feature on the KSC Web. In the background is the open hatch of the airlock, located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

NASA Image and Video Library

2004-01-22

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, a cameraman films part of Discovery’s payload bay for a special feature on the KSC Web. In the background is the open hatch of the airlock, located inside the middeck of the spacecraft’s pressurized crew cabin. The airlock is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

KENNEDY SPACE CENTER, FLA. - Standing inside Discovery’s payload bay, Carol Scott (right), lead orbiter engineer, talks about her job as part of a special feature for the KSC Web. With his back to the camera is Bill Kallus, Media manager in the KSC Web Studio. Behind Scott can be seen the open hatch of the airlock, which provides support functions such as airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

NASA Image and Video Library

2004-01-22

KENNEDY SPACE CENTER, FLA. - Standing inside Discovery’s payload bay, Carol Scott (right), lead orbiter engineer, talks about her job as part of a special feature for the KSC Web. With his back to the camera is Bill Kallus, Media manager in the KSC Web Studio. Behind Scott can be seen the open hatch of the airlock, which provides support functions such as airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, donning and communications. The outer hatch isolates the airlock from the unpressurized payload bay when closed and permits the EVA crew members to exit from the airlock to the payload bay when open.

Seismic anisotropy and mantle flow below subducting slabs

NASA Astrophysics Data System (ADS)

Walpole, Jack; Wookey, James; Kendall, J.-Michael; Masters, T.-Guy

2017-05-01

Subduction is integral to mantle convection and plate tectonics, yet the role of the subslab mantle in this process is poorly understood. Some propose that decoupling from the slab permits widespread trench parallel flow in the subslab mantle, although the geodynamical feasibility of this has been questioned. Here, we use the source-side shear wave splitting technique to probe anisotropy beneath subducting slabs, enabling us to test petrofabric models and constrain the geometry of mantle fow. Our global dataset contains 6369 high quality measurements - spanning ∼ 40 , 000 km of subduction zone trenches - over the complete range of available source depths (4 to 687 km) - and a large range of angles in the slab reference frame. We find that anisotropy in the subslab mantle is well characterised by tilted transverse isotropy with a slow-symmetry-axis pointing normal to the plane of the slab. This appears incompatible with purely trench-parallel flow models. On the other hand it is compatible with the idea that the asthenosphere is tilted and entrained during subduction. Trench parallel measurements are most commonly associated with shallow events (source depth < 50 km) - suggesting a separate region of anisotropy in the lithospheric slab. This may correspond to the shape preferred orientation of cracks, fractures, and faults opened by slab bending. Meanwhile the deepest events probe the upper lower mantle where splitting is found to be consistent with deformed bridgmanite.

DEMONSTRATION OF RADON RESISTANT CONSTRUCTION TECHNIQUES - PHASE II. FINAL REPORT

EPA Science Inventory

The report gives results of a demonstration of radon resistant construction techniques. Sub-slab mitigation systems were installed (in accordance with draft standards) in 15 new Florida houses in 1992, and these houses have undergone extensive testing to validate techniques used ...

Simple, Efficient, and Rapid Methods to Determine the Potential for Vapor Intrusion into the Home: Temporal Trends, Vapor Intrusion Forecasting, Sampling Strategies, and Contaminant Migration Routes

EPA Science Inventory

Current practice for evaluating the vapor intrusion pathway involves a multiple line of evidence approach based on direct measurements of volatile organic compound (VOC) concentrations in groundwater, external soil gas, subslab soil gas, and/or indoor air. No single line of evide...

Laboratory Evaluation of Energy Recovery Ventilators

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

Kosar, D.

Over the years, building scientists have characterized the relationship between building airtightness, exhaust-only appliances airflows, and building depressurization. Now, as the use of deep retrofit measures and new construction practices is growing to realize lower infiltration levels in increasingly tighter envelopes, performance issues can arise with the operation of exhaust-only appliances in a depressurized home. As the depressurization levels climb in tighter homes, many of these exhaust-only appliances see their rated airflows reduced and other related performance issues arise as a result. If sufficiently depressurized, atmospherically vented combustion appliances that may be present in the home can backdraft as well.more » Furthermore, when exhaust-only appliances operate and the tight home becomes depressurized, water vapor intrusion from outdoors can raise additional issues of mold in the building envelope in more humid climates.« less

Love-to-Rayleigh Conversions and Seismic Anisotropy in Cascadia

NASA Astrophysics Data System (ADS)

Rieger, Duayne Matthew

Seismic anisotropy is often attributed to the development of lattice-preferred orientation (LPO) of olivine crystals in peridotite, induced by the dislocation creep component of mantle deformation (Karato et al., 2008; Ribe, 1992). Mantle-flow-induced seismic anisotropy is often modeled in the simple form of hexagonal symmetry, where the anisotropic volume is uniaxially fast or slow. This relationship between seismic anisotropy and mantle deformation allows for the mapping of mantle dynamics using measurements of seismic anisotropy. Presently, methods of measuring seismic anisotropy in Earth's mantle include shear-wave splitting and surface-wave tomography. These methods are tuned to seismically fast axes laying in the horizontal or surface-tangent plane and are limited in discerning clipping seismic fast axes. This is a shortcoming. It is reasonable to suspect the presence of dipping seismic fast axes induced by mantle flow in several tectonic regimes such as subduction zones. The slab rollback model of the subduction zone system has been argued to exhibit trench-parallel subslab anisotropy due to the lateral evacuation of the subslab mantle material (Hall et al., 2000; Russo and Silver, 1994). This model has been emboldened by the dominance of trench-parallel shear-wave-splitting measurements in the subslab mantle of global subduction zones. This model has significant geodynamic implications, requiring viscous decoupling between the subslab mantle and the sub-ducting slab. The Cascadian subduction zone is of particular scientific interest. While experiencing slab rollback (Zandt and Humphreys, 2008), trench-perpendicular shear-wave-splitting measurements are observed in the subslab mantle of Cascadia (Currie et al., 2004; Eakin et al., 2010; Long and Silver, 2008; 2009). This suggests either viscous coupling resulting in slab-entrained flow or the presence of an alternate relationship between finite strain in the mantle and seismic anisotropy. The ability to

Vertical Distribution of VOCs in Soils from Groundwater to the Surface/Subslab

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) is charged by ongress with protecting the nation’s natural resources. Under the mandate of national environmental laws, the EPA strives to formulate and implement actions leading to a compatible balance between human activities and ...

Temporal Variation of VOCs in Soils from Groundwater to the Surface/Subslab

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the nation’s natural resources. Under the mandate of national environmental laws, the EPA strives to formulate and implement actions leading to a compatible balance between human activities and ...

Fluctuation of Indoor Radon and VOC Concentrations Due to Seasonal Variations

EPA Science Inventory

This research was conducted to better characterize the spatial and temporal variability of vapor intrusion by collecting a full year’s dataset of weekly measurements of subslab soil gas, external soil gas, and indoor air, on a single house that is impacted by vapor intrusion of r...

POSSIBLE ROLE OF INDOOR RADON REDUCTION SYSTEMS IN BACK-DRAFTING RESIDENTIAL COMBUSTION APPLIANCES

EPA Science Inventory

The article gives results of a computational sensitivity analysis conducted to identify conditions under which residential active soil depressurization (ASD) systems for indoor radon reduction might contribute to or create back-drafting of natural draft combustion appliances. Par...

TESTING OF INDOOR RADON REDUCTION TECHNIQUES IN CENTRAL OHIO HOUSES: PHASE 2 (WINTER 1988-1989)

EPA Science Inventory

The report gives results of tests of developmental indoor radon reduction techniques in nine slab-on-grade and four crawl-space houses near Dayton. Ohio. he slab-on-grade tests indicated that, when there is a good layer of aggregate under the slab, the sub-slab ventilation (SSV) ...

TESTING OF INDOOR RADON REDUCTION TECHNIQUES IN BASEMENT HOUSES HAVING ADJOINING WINGS

EPA Science Inventory

The report gives results of tests of indoor radon reduction techniques in 12 existing Maryland houses, with the objective of determining when basement houses with adjoining wings require active soil depressurization (ASD) treatment of both wings, and when treatment of the basemen...

Non-equilibrium simulation of CH4 production through the depressurization method from gas hydrate reservoirs

NASA Astrophysics Data System (ADS)

Qorbani, Khadijeh; Kvamme, Bjørn

2016-04-01

as non-equilibrium processes under local constraint of mass and heat fluxes. In this work, we have extended RCB by adding another route for dissociation or reformation of CH4-hydrate towards CH4 into the aqueous phase and water. CH4-hydrate formation and dissociation is resolved by looking at supersaturation and undersaturation with respect to thermodynamics variables. Hydrate instability due to undersaturation of CH4 in the contacting water phase is also considered. A complete non-equilibrium thermodynamic package, developed in-house, was combined with RCB to account for competing phase transitions by considering the minimization of Gibb's free energy. The energy differences were calculated from variations in chemical potentials of hydrate and hydrate formers. Mass transport, heat transport and non-equilibrium thermodynamic effects were implemented through classical nucleation theory to model the kinetic rate of hydrate phase transitions. To illustrate our implementations we ran simulations covering time-spans in the order of hundred years. CH4 production was modelled using the depressurization method, where we employed the Messoyakha field data. We discuss our implementations, as well as results obtained from simulations utilizing our modifications.

PHYSICAL AND NUMERICAL MODELING OF ASD EXHAUST DISPERSION AROUND HOUSES

EPA Science Inventory

The report discusses the use of a wind tunnel to physically model the dispersion of exhaust plumes from active soil depressurization (ASD) radon mitigation systems in houses. he testing studied the effects of exhaust location (grade level vs. above the eave), as house height, roo...

Supercritical impregnation of cinnamaldehyde into polylactic acid as a route to develop antibacterial food packaging materials.

PubMed

Villegas, Carolina; Torres, Alejandra; Rios, Mauricio; Rojas, Adrián; Romero, Julio; de Dicastillo, Carol López; Valenzuela, Ximena; Galotto, María José; Guarda, Abel

2017-09-01

Supercritical impregnation was used to incorporate a natural compound with antibacterial activity into biopolymer-based films to develop active food packaging materials. Impregnation tests were carried out under two pressure conditions (9 and 12MPa), and three depressurization rates (0.1, 1 and 10MPamin -1 ) in a high-pressure cell at a constant temperature equal to 40°C. Cinnamaldehyde (Ci), a natural compound with proven antimicrobial activity, was successfully incorporated into poly(lactic acid) films (PLA) using supercritical carbon dioxide (scCO 2 ), with impregnation yields ranging from 8 to 13% w/w. Higher pressure and slower depressurization rate seem to favor the Ci impregnation. The incorporation of Ci improved thermal, structural and mechanical properties of the PLA films. Impregnated films were more flexible, less brittle and more resistant materials than neat PLA films. The tested samples showed strong antibacterial activity against the selected microorganisms. In summary, this study provides an innovative route to the development of antibacterial biodegradable materials, which could be used in a wide range of applications of active food packaging. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impregnation of cinnamaldehyde into cassava starch biocomposite films using supercritical fluid technology for the development of food active packaging.

PubMed

de Souza, Ana Cristina; Dias, Ana M A; Sousa, Hermínio C; Tadini, Carmen C

2014-02-15

In this work, supercritical solvent impregnation (SSI) has been tested for the incorporation of natural compounds into biocomposite materials for food packaging. Cinnamaldehyde, with proved antimicrobial activity against fungi commonly found in bread products, was successfully impregnated on biocomposite cassava starch based materials using supercritical carbon dioxide as solvent. Different process experimental conditions were tested (pressure, impregnation time and depressurization rate) at a fixed temperature (35 °C) in order to study their influence on the amount of impregnated cinnamaldehyde as well as on the morphology of the films. Results showed that all conditions permitted to impregnate antimicrobial active amounts superior to those previously obtained using conventional incorporation methods. Moreover, a significant decrease of the equilibrium water vapor sorption capacity and water vapor permeability of the films was observed after SSI processing which is a clear advantage of the process, considering the envisaged applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

Predicting Backdrafting and Spillage for Natural-Draft Gas Combustion Appliances: Validating VENT-II

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

Rapp, Vi H.; Pastor-Perez, Albert; Singer, Brett C.

2013-04-01

VENT-II is a computer program designed to provide detailed analysis of natural draft and induced draft combustion appliance vent-systems (i.e., furnace or water heater). This program is capable of predicting house depressurization thresholds that lead to backdrafting and spillage of combustion appliances; however, validation reports of the program being applied for this purpose are not readily available. The purpose of this report is to assess VENT-II’s ability to predict combustion gas spillage events due to house depressurization by comparing VENT-II simulated results with experimental data for four appliance configurations. The results show that VENT-II correctly predicts depressurizations resulting in spillagemore » for natural draft appliances operating in cold and mild outdoor conditions, but not for hot conditions. In the latter case, the predicted depressurizations depend on whether the vent section is defined as part of the vent connector or the common vent when setting up the model. Overall, the VENTII solver requires further investigation before it can be used reliably to predict spillage caused by depressurization over a full year of weather conditions, especially where hot conditions occur.« less

Application of Advanced Sensor Technology to DoD Soil Vapor Intrusion Problems

DTIC Science & Technology

2012-10-01

19 Figure 10. Photographs of: a) Layton , Utah, ASU SERDP project study house and b) basement...relative to sub-slab; line). ..................... 24 Figure 18. Spatial distributions of TCE in Layton , Utah, house without VI and emplaced indoor...technical advice and use of ASU’s Strategic Environmental Research and Development Program (SERDP) VI study house in Layton , Utah, is very

Numerical simulations of depressurization-induced gas production from gas hydrate reservoirs at the Walker Ridge 312 site, northern Gulf of Mexico

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

Myshakin, Evgeniy M.; Gaddipati, Manohar; Rose, Kelly

2012-06-01

In 2009, the Gulf of Mexico (GOM) Gas Hydrates Joint-Industry-Project (JIP) Leg II drilling program confirmed that gas hydrate occurs at high saturations within reservoir-quality sands in the GOM. A comprehensive logging-while-drilling dataset was collected from seven wells at three sites, including two wells at the Walker Ridge 313 site. By constraining the saturations and thicknesses of hydrate-bearing sands using logging-while-drilling data, two-dimensional (2D), cylindrical, r-z and three-dimensional (3D) reservoir models were simulated. The gas hydrate occurrences inferred from seismic analysis are used to delineate the areal extent of the 3D reservoir models. Numerical simulations of gas production from themore » Walker Ridge reservoirs were conducted using the depressurization method at a constant bottomhole pressure. Results of these simulations indicate that these hydrate deposits are readily produced, owing to high intrinsic reservoir-quality and their proximity to the base of hydrate stability. The elevated in situ reservoir temperatures contribute to high (5–40 MMscf/day) predicted production rates. The production rates obtained from the 2D and 3D models are in close agreement. To evaluate the effect of spatial dimensions, the 2D reservoir domains were simulated at two outer radii. The results showed increased potential for formation of secondary hydrate and appearance of lag time for production rates as reservoir size increases. Similar phenomena were observed in the 3D reservoir models. The results also suggest that interbedded gas hydrate accumulations might be preferable targets for gas production in comparison with massive deposits. Hydrate in such accumulations can be readily dissociated due to heat supply from surrounding hydrate-free zones. Special cases were considered to evaluate the effect of overburden and underburden permeability on production. The obtained data show that production can be significantly degraded in comparison with a

Basement radon entry and stack driven moisture infiltration reduced by active soil depressurization

Treesearch

C.R. Boardman; Samuel V. Glass

2015-01-01

This case study presents measurements of radon and moisture infiltration from soil gases into the basement of an unoccupied research house in Madison, Wisconsin, over two full years. The basement floor and exterior walls were constructed with preservative-treated lumber and plywood. In addition to continuous radon monitoring, measurements included building air...

System and method for slurry handling

DOEpatents

Steele, Raymond Douglas; Oppenheim, Judith Pauline

2015-12-29

A system includes a slurry depressurizing system that includes a liquid expansion system configured to continuously receive a slurry at a first pressure and continuously discharge the slurry at a second pressure. For example, the slurry depressurizing system may include an expansion turbine to expand the slurry from the first pressure to the second pressure.

Simulating the effect of slab features on vapor intrusion of crack entry

PubMed Central

Yao, Yijun; Pennell, Kelly G.; Suuberg, Eric M.

2012-01-01

In vapor intrusion screening models, a most widely employed assumption in simulating the entry of contaminant into a building is that of a crack in the building foundation slab. Some modelers employed a perimeter crack hypothesis while others chose not to identify the crack type. However, few studies have systematically investigated the influence on vapor intrusion predictions of slab crack features, such as the shape and distribution of slab cracks and related to this overall building foundation footprint size. In this paper, predictions from a three-dimensional model of vapor intrusion are used to compare the contaminant mass flow rates into buildings with different foundation slab crack features. The simulations show that the contaminant mass flow rate into the building does not change much for different assumed slab crack shapes and locations, and the foundation footprint size does not play a significant role in determining contaminant mass flow rate through a unit area of crack. Moreover, the simulation helped reveal the distribution of subslab contaminant soil vapor concentration beneath the foundation, and the results suggest that in most cases involving no biodegradation, the variation in subslab concentration should not exceed an order of magnitude, and is often significantly less than this. PMID:23359620

Synthetic scaffolds with full pore interconnectivity for bone regeneration prepared by supercritical foaming using advanced biofunctional plasticizers.

PubMed

Salerno, Aurelio; Diéguez, Sara; Diaz-Gomez, Luis; Gómez-Amoza, José L; Magariños, Beatriz; Concheiro, Angel; Domingo, Concepción; Alvarez-Lorenzo, Carmen; García-González, Carlos A

2017-06-30

Supercritical foaming allows for the solvent-free processing of synthetic scaffolds for bone regeneration. However, the control on the pore interconnectivity and throat pore size with this technique still needs to be improved. The use of plasticizers may help overcome these limitations. Eugenol, a GRAS natural compound extracted from plants, is proposed in this work as an advanced plasticizer with bioactive properties. Eugenol-containing poly(ε-caprolactone) (PCL) scaffolds were obtained by supercritical foaming (20.0 MPa, 45 °C, 17 h) followed by a one or a two-step depressurization profile. The effects of the eugenol content and the depressurization profile on the porous structure of the material and the physicochemical properties of the scaffold were evaluated. The combination of both processing parameters was successful to simultaneously tune the pore interconnectivity and throat sizes to allow mesenchymal stem cells infiltration. Scaffolds with eugenol were cytocompatible, presented antimicrobial activity preventing the attachment of Gram positive (S. aureus, S. epidermidis) bacteria and showed good tissue integration.

Basic Study on Production Well Integrity for Methane Hydrate Development

NASA Astrophysics Data System (ADS)

Kakumoto, M.; Yoneda, J.; Katagiri, J.; Tenma, N.; Aoki, K.

2014-12-01

Methane Hydrate (MH) exist as an ice-like crystal under low-temperature and high-pressure condition, and it has gathering attention as a non-conventional natural gas resource. Depressurization method is a method to reduce the bottom hole pressure by submersible pump lowering water level in the production well, and gas and water is recovered by MH dissociation at the in situ. During the depressurization operation, consolidation and deformation of sediment occurs because of increase of effective stress by depressurization and changes in the soil structure by MH dissociation. Then consolidation and deformation of sediment makes negative friction between the production well and sediment, and large stress is occur in casing. Therefore there is concern that it may cause compression failure and shear failure of the production well. For safe MH development, it is necessary to grasp the deformation and stress vicinity of the production well. At first, we conducted push-out test to get friction strength between the different materials simulated the well and sediment. And we have done numerical analysis for integrity using by these data. The results of numerical analysis showed that the large deformation of sediment occur around the depressurization zone, and for the well, the large tensile stress in the vertical direction occur the upper vicinity of the depressurization zone.This study was financially supported by the Research Consortium for Methane Hydrate Resources in Japan (MH21 Research Consortium) planned by Ministry of Economy, Trade and Industry (METI). The authors thank the entire personnel related to MH21 Research Consortium.

Method for preparing membranes with adjustable separation performance

DOEpatents

Peterson, E.S.; Orme, C.J.; Stone, M.L.

1995-01-31

Methods for adjustable separation of solutes and solvents involve the combination of the use of a maximally swollen membrane and subsequent vacuum depressurization exerted on the permeate side of that membrane. By adjusting the extent of depressurization it is possible to separate solvent from solutes and solutes from each other. Improved control of separation parameters as well as improved flux rates characterize the present invention. 2 figs.

Method for preparing membranes with adjustable separation performance

DOEpatents

Peterson, Eric S.; Orme, Christopher J.; Stone, Mark L.

1995-01-01

Methods for adjustable separation of solutes and solvents involve the combination of the use of a maximally swollen membrane and subsequent vacuum depressurization exerted on the permeate side of that membrane. By adjusting the extent of depressurization it is possible to separate solvent from solutes and solutes from each other. Improved control of separation parameters as well as improved flux rates characterize the present invention.

The January 2015 Repressurization of ISS ATCS Loop B - Analysis Limitations and Concerns

NASA Technical Reports Server (NTRS)

Ungar, Eugene; Rankin, J. Gary; Schaff, Mary; Figueroa, Marcelino

2015-01-01

In January 2013 a false ammonia leak alarm resulted in the shutdown and partial depressurization of one of the two International Space Station (ISS) External Active Thermal Control System (EATCS) loops. The depressurization resulted in a vapor bubble of 18 liters in warm parts of the stagnant loop. To repressurize the loop and regain system operation, liquid would have to be moved from the Ammonia Tank Assembly (ATA) into the loop. This resulted in the possibility of moving cold (as low as -30 C) ammonia into the water-filled Internal Active Thermal Control System (IATCS) interface heat exchangers. Before moving forward, the freezing potential of the repressurization was evaluated through analysis - using both a Thermal Desktop SINDA/FLUINT model and hand calculations. The models yielded very different results, but both models indicated that heat exchanger freezing was not an issue. Therefore, the repressurization proceeded. The presentation describes the physical situation of the EATCS prior to repressurization and discusses the potential limits and pitfalls of the repressurization. The pre-repressurization analytical models and their results are discussed. The successful repressurization is describled and the results of a post-event model assessment is detailed.

Testing radon mitigation techniques in a pilot house from Băiţa-Ştei radon prone area (Romania).

PubMed

Cosma, Constantin; Papp, Botond; Cucoş Dinu, Alexandra; Sainz, Carlos

2015-02-01

This work presents the implementation and testing of several radon mitigation techniques in a pilot house in the radon prone area of Băiţa-Ştei in NW part of Romania. Radon diagnostic investigations in the pilot house showed that the main source of radon was the building sub-soil and the soil near the house. The applied techniques were based on the depressurization and pressurization of the building sub-soil, on the combination of the soil depressurization system by an electric and an eolian fans. Also, there was made an application of a radon barrier membrane and a testing by the combination of the radon membrane by the soil depressurization system. Finally, the better obtained remedial efficiency was about 85%. Copyright © 2014 Elsevier Ltd. All rights reserved.

Exploratory Study of Basement Moisture During Operation of Active Soil Depressurization Radon Control Systems

EPA Pesticide Factsheets

As part of an exploratory study, three houses were monitored for moisture indicators, radon levels, building operations, and other environmental parameters while ASD systems were cycled on and off. December 6, 2007, Revised 3/10/08.

Tomographic Imaging of the Cascadia Subduction Zone and Juan de Fuca Plate System: Improved Methods Eliminate Artifacts and Reveal New Structures

NASA Astrophysics Data System (ADS)

Bodmer, M.; Toomey, D. R.; Hooft, E. E. E.; Bezada, M.; Schmandt, B.; Byrnes, J. S.

2017-12-01

Amphibious studies of subduction zones promise advances in understanding links between incoming plate structure, the subducting slab, and the upper mantle beneath the slab. However, joint onshore/offshore imaging is challenging due to contrasts between continental and oceanic structure. We present P-wave teleseismic tomography results for the Cascadia subduction zone (CSZ) that utilize existing western US datasets, amphibious seismic data from the Cascadia Initiative, and tomographic algorithms that permit 3D starting models, nonlinear ray tracing, and finite frequency kernels. Relative delay times show systematic onshore/offshore trends, which we attribute to structure in the upper 50 km. Shore-crossing CSZ seismic refraction models predict relative delays >1s, with equal contributions from elevation and crustal thickness. We use synthetic data to test methods of accounting for such shallow structure. Synthetic tests using only station static terms produce margin-wide, sub-slab low-velocity artifacts. Using a more realistic a priori 3D model for the upper 50 km better reproduces known input structures. To invert the observed delays, we use data-constrained starting models of the CSZ. Our preferred models utilize regional surface wave studies to construct a starting model, directly account for elevation, and use 3D nonlinear ray tracing. We image well-documented CSZ features, including the subducted slab down to 350 km, along strike slab variations below 150 km, and deep slab fragmentation. Inclusion of offshore data improves resolution of the sub-slab mantle, where we resolve localized low-velocity anomalies near the edges of the CSZ (beneath the Klamath and Olympic mountains). Our new imaging and resolution tests indicate that previously reported margin-wide, sub-slab low-velocity asthenospheric anomalies are an imaging artifact. Offshore, we observe low-velocity anomalies beneath the Gorda plate consistent with regional deformation and broad upwelling resulting

Geodynamic Modeling of the Subduction Zone around the Japanese Islands

NASA Astrophysics Data System (ADS)

Honda, S.

2017-06-01

In this review, which focuses on our research, we describe the development of the thermomechanical modeling of subduction zones, paying special attention to those around the Japanese Islands. Without a sufficient amount of data and observations, models tended to be conceptual and general. However, the increasing power of computational tools has resulted in simple analytical and numerical models becoming more realistic, by incorporating the mantle flow around the subducting slab. The accumulation of observations and data has made it possible to construct regional models to understand the detail of the subduction processes. Recent advancements in the study of the seismic tomography and geology around the Japanese Islands has enabled new aspects of modeling the mantle processes. A good correlation between the seismic velocity anomalies and the finger-like distribution of volcanoes in northeast Japan has been recognized and small-scale convection (SSC) in the mantle wedge has been proposed to explain such a feature. The spatial and temporal evolution of the distribution of past volcanoes may reflect the characteristics of the flow in the mantle wedge, and points to the possibility of the flip-flopping of the finger-like pattern of the volcano distribution and the migration of volcanic activity from the back-arc side to the trench side. These observations are found to be qualitatively consistent with the results of the SSC model. We have also investigated the expected seismic anisotropy in the presence of SSC. The fast direction of the P-wave anisotropy generally shows the trench-normal direction with a reduced magnitude compared to the case without SSC. An analysis of full 3D seismic anisotropy is necessary to confirm the existence and nature of SSC. The 3D mantle flow around the subduction zone of plate-size scale has been modeled. It was found that the trench-parallel flow in the sub-slab mantle around the northern edge of the Pacific plate at the junction between

Survival and ice nucleation activity of bacteria as aerosols in a cloud simulation chamber

NASA Astrophysics Data System (ADS)

Amato, P.; Joly, M.; Schaupp, C.; Attard, E.; Möhler, O.; Morris, C. E.; Brunet, Y..; Delort, A.-M.

2015-02-01

The residence time of bacterial cells in the atmosphere is predictable by numerical models. However, estimations of their aerial dispersion as living entities are limited by lacks of information concerning survival rates and behavior in relation to atmospheric water. Here we investigate the viability and ice nucleation (IN) activity of typical atmospheric ice nucleation active bacteria (Pseudomonas syringae and P. fluorescens) when airborne in a cloud simulation chamber (AIDA, Karlsruhe, Germany). Cell suspensions were sprayed into the chamber and aerosol samples were collected by impingement at designated times over a total duration of up to 18 h, and at some occasions after dissipation of a cloud formed by depressurization. Aerosol concentration was monitored simultaneously by online instruments. The cultivability of airborne cells decreased exponentially over time with a half-life time of 250 ± 30 min (about 3.5 to 4.5 h). In contrast, IN activity remained unchanged for several hours after aerosolization, demonstrating that IN activity was maintained after cell death. Interestingly, the relative abundance of IN active cells still airborne in the chamber was strongly decreased after cloud formation and dissipation. This illustrates the preferential precipitation of IN active cells by wet processes. Our results indicate that from 106 = cells aerosolized from a surface, one would survive the average duration of its atmospheric journey estimated at 3.4 days. Statistically, this corresponds to the emission of 1 cell that achieves dissemination every ~33 min per m2 of cultivated crops fields, a strong source of airborne bacteria. Based on the observed survival rates, depending on wind speed, the trajectory endpoint could be situated several hundreds to thousands of kilometers from the emission source. These results should improve the representation of the aerial dissemination of bacteria in numeric models.

Survival and ice nucleation activity of bacteria as aerosols in a cloud simulation chamber

NASA Astrophysics Data System (ADS)

Amato, P.; Joly, M.; Schaupp, C.; Attard, E.; Möhler, O.; Morris, C. E.; Brunet, Y.; Delort, A.-M.

2015-06-01

The residence time of bacterial cells in the atmosphere is predictable by numerical models. However, estimations of their aerial dispersion as living entities are limited by a lack of information concerning survival rates and behavior in relation to atmospheric water. Here we investigate the viability and ice nucleation (IN) activity of typical atmospheric ice nucleation active bacteria (Pseudomonas syringae and P. fluorescens) when airborne in a cloud simulation chamber (AIDA, Karlsruhe, Germany). Cell suspensions were sprayed into the chamber and aerosol samples were collected by impingement at designated times over a total duration of up to 18 h, and at some occasions after dissipation of a cloud formed by depressurization. Aerosol concentration was monitored simultaneously by online instruments. The cultivability of airborne cells decreased exponentially over time with a half-life time of 250 ± 30 min (about 3.5 to 4.5 h). In contrast, IN activity remained unchanged for several hours after aerosolization, demonstrating that IN activity was maintained after cell death. Interestingly, the relative abundance of IN active cells still airborne in the chamber was strongly decreased after cloud formation and dissipation. This illustrates the preferential precipitation of IN active cells by wet processes. Our results indicate that from 106 cells aerosolized from a surface, one would survive the average duration of its atmospheric journey estimated at 3.4 days. Statistically, this corresponds to the emission of 1 cell that achieves dissemination every ~ 33 min m-2 of cultivated crops fields, a strong source of airborne bacteria. Based on the observed survival rates, depending on wind speed, the trajectory endpoint could be situated several hundreds to thousands of kilometers from the emission source. These results should improve the representation of the aerial dissemination of bacteria in numeric models.

Linking Plagioclase Zoning Patterns to Active Magma Processes

NASA Astrophysics Data System (ADS)

Izbekov, P. E.; Nicolaysen, K. P.; Neill, O. K.; Shcherbakov, V.; Eichelberger, J. C.; Plechov, P.

2016-12-01

Plagioclase, one of the most common and abundant mineral phases in volcanic products, will vary in composition in response to changes in temperature, pressure, composition of the ambient silicate melt, and melt H2O concentration. Changes in these parameters may cause dissolution or growth of plagioclase crystals, forming characteristic textural and compositional variations (zoning patterns), the complete core-to-rim sequence of which describes events experienced by an individual crystal from its nucleation to the last moments of its growth. Plagioclase crystals in a typical volcanic rock may look drastically dissimilar despite their spatial proximity and the fact that they have erupted together. Although they shared last moments of their growth during magma ascent and eruption, their prior experiences could be very different, as plagioclase crystals often come from different domains of the same magma system. Distinguishing similar zoning patterns, correlating them across the entire population of plagioclase crystals, and linking these patterns to specific perturbations in the magmatic system may provide additional perspective on the variety, extent, and timing of magma processes at active volcanic systems. Examples of magma processes, which may be distinguished based on plagioclase zoning patterns, include (1) cooling due to heat loss, (2) heating and/or pressure build up due to an input of new magmatic material, (3) pressure drop in response to magma system depressurization, and (4) crystal transfer between different magma domains/bodies. This review will include contrasting examples of zoning patters from recent eruptions of Augustine and Cleveland Volcanoes in Alaska, Sakurajima Volcano in Japan, Karymsky, Bezymianny, and Tolbachik Volcanoes in Kamchatka, as well as from the drilling into an active magma body at Krafla, Iceland.

Linking Plagioclase Zoning Patterns to Active Magma Processes

NASA Astrophysics Data System (ADS)

Izbekov, P. E.; Nicolaysen, K. P.; Neill, O. K.; Shcherbakov, V.; Plechov, P.; Eichelberger, J. C.

2015-12-01

Plagioclase, one of the most common and abundant mineral phases in volcanic products, will vary in composition in response to changes in temperature, pressure, composition of the ambient silicate melt, and melt H2O concentration. Changes in these parameters may cause dissolution or growth of plagioclase crystals, forming characteristic textural and compositional variations (zoning patterns), the complete core-to-rim sequence of which describes events experienced by an individual crystal from its nucleation to the last moments of its growth. Plagioclase crystals in a typical volcanic rock may look drastically dissimilar despite their spatial proximity and the fact that they have erupted together. Although they shared last moments of their growth during magma ascent and eruption, their prior experiences could be very different, as plagioclase crystals often come from different domains of the same magma system. Distinguishing similar zoning patterns, correlating them across the entire population of plagioclase crystals, and linking these patterns to specific perturbations in the magmatic system may provide additional perspective on the variety, extent, and timing of magma processes at active volcanic systems. Examples of magma processes, which may be distinguished based on plagioclase zoning patterns, include (1) cooling due to heat loss, (2) heating and/or pressure build up due to an input of new magmatic material, (3) pressure drop in response to magma system depressurization, and (4) crystal transfer between different magma domains/bodies. This review will include contrasting examples of zoning patters from recent eruptions of Karymsky, Bezymianny, and Tolbachik Volcanoes in Kamchatka, Augustine and Cleveland Volcanoes in Alaska, as well as from the drilling into an active magma body at Krafla, Iceland.

Pumping and Depressurizing of Insulation Materials

NASA Technical Reports Server (NTRS)

Porter, Amber

2010-01-01

The Fluids Testing and Technology Branch is a group that researches and tests efficient ways to use various Cryogenic Fluids, such as Liquid Nitrogen or Liquid Helium, in ground and space systems. Their main goal is to develop new technologies involving Cryogenic temperatures as well as making sure the existing technologies are understood. During my time here a lot of insulation testing has been done which is where insulation systems are tested for cryogenic systems that are in space for long durations.

The assessment of different production methods for hydrate bearing sediments - results from small and large scale experiments

NASA Astrophysics Data System (ADS)

Schicks, Judith; Heeschen, Katja; Spangenberg, Erik; Luzi-Helbing, Manja; Beeskow-Strauch, Bettina; Priegnitz, Mike; Giese, Ronny; Abendroth, Sven; Thaler, Jan

2017-04-01

Natural gas hydrates occur at all active and passive continental margins, in permafrost regions, and deep lakes. Since they are supposed to contain enormous amounts of methane, gas hydrates are discussed as an energy resource. For the production of gas from hydrate bearing sediments, three different production methods were tested during the last decade: depressurization, thermal and chemical stimulation as well as combinations of these methods. In the framework of the SUGAR project we developed a Large Scale Reservoir Simulator (LARS) with a total volume of 425L to test these three methods in a pilot plant scale. For this purpose we formed hydrate from methane saturated brine in sediments under conditions close to natural gas hydrate deposits. The obtained hydrate saturations varied between 40-90%. Hydrate saturation and distribution were determined using electrical resistivity tomography (ERT). The volumes of the produced gas and water were determined and the gas phase was analyzed via gas chromatography. Multi-step depressurization, thermal stimulation applying in-situ combustion as well as chemical stimulation via the injection of CO2 and a CO2-N2-mixture were tested. Depressurization and thermal stimulation appear to be less complicated compared to the chemical stimulation. For the understanding of the macroscopically observed processes on a molecular level, we also performed experiments on a smaller scale using microscopic observation, Raman spectroscopy and X-ray diffraction. The results of these experiments are of particular importance for the understanding of the processes occurring during the CO2-CH4 swapping. Under the chosen experimental conditions the observations indicate a (partial) decomposition and reformation of the hydrate structure rather than a diffusion-controlled exchange of the molecules.

Inversion for Double-Layer Anisotropy in the Mantle Beneath the Middle America and Izu-Bonin Subduction Zones

NASA Astrophysics Data System (ADS)

Kuo, B. Y.

2017-12-01

We measured shear wave splitting for the intraslab events in the Middle America and Izu-Bonin subduction zones recorded at Pacific stations to infer the anisotropic structure in the subslab mantle. The receiver-side anisotropy is accounted for by considering both azimuthal anisotropy determined by SKS splitting and radial anisotropy given in global tomographic model, although the latter does not change the overall pattern of subslab anisotropy. By removing the anisotropy effects from both receiver and source sides, the initial polarization directions (p) of the shear waves used were recovered, most of which are in reasonable agreement with that predicted form the CMT solutions. For both subduction zones, the polarization-splitting plots strongly suggest the presence of two layers of anisotropy. To constrain the two-layer model, we perform inversions which minimize the misfit in both the splitting parameters and p. In the MASZ, the best model contains an upper layer with the fast direction in parallel with the absolute plate motion of the Cocos plate and a lower layer 40-60 degree clockwise from the APM. The delay times are 1.5 and 1.9 s respectively. The interference of the double layer produced dts in excess of 3 s at a certain range of p. The SKS splitting were also inverted for a two-layer model, yielding similar splitting characters and the clockwise rotation. We are investigating why this rotation takes place and how this observation is related to the dynamics of the asthenosphere.

Active Joint Mechanism Driven by Multiple Actuators Made of Flexible Bags: A Proposal of Dual Structural Actuator

PubMed Central

Inou, Norio

2013-01-01

An actuator is required to change its speed and force depending on the situation. Using multiple actuators for one driving axis is one of the possible solutions; however, there is an associated problem of output power matching. This study proposes a new active joint mechanism using multiple actuators. Because the actuator is made of a flexible bag, it does not interfere with other actuators when it is depressurized. The proposed joint achieved coordinated motion of multiple actuators. This report also discusses a new actuator which has dual cylindrical structure. The cylinders are composed of flexible bags with different diameters. The joint torque is estimated based on the following factors: empirical formula for the flexible actuator torque, geometric relationship between the joint and the actuator, and the principle of virtual work. The prototype joint mechanism achieves coordinated motion of multiple actuators for one axis. With this motion, small inner actuator contributes high speed motion, whereas large outer actuator generates high torque. The performance of the prototype joint is examined by speed and torque measurements. The joint showed about 30% efficiency at 2.0 Nm load torque under 0.15 MPa air input. PMID:24385868

Active joint mechanism driven by multiple actuators made of flexible bags: a proposal of dual structural actuator.

PubMed

Kimura, Hitoshi; Matsuzaki, Takuya; Kataoka, Mokutaro; Inou, Norio

2013-01-01

An actuator is required to change its speed and force depending on the situation. Using multiple actuators for one driving axis is one of the possible solutions; however, there is an associated problem of output power matching. This study proposes a new active joint mechanism using multiple actuators. Because the actuator is made of a flexible bag, it does not interfere with other actuators when it is depressurized. The proposed joint achieved coordinated motion of multiple actuators. This report also discusses a new actuator which has dual cylindrical structure. The cylinders are composed of flexible bags with different diameters. The joint torque is estimated based on the following factors: empirical formula for the flexible actuator torque, geometric relationship between the joint and the actuator, and the principle of virtual work. The prototype joint mechanism achieves coordinated motion of multiple actuators for one axis. With this motion, small inner actuator contributes high speed motion, whereas large outer actuator generates high torque. The performance of the prototype joint is examined by speed and torque measurements. The joint showed about 30% efficiency at 2.0 Nm load torque under 0.15 MPa air input.

Temporary vs. Permanent Sub-slab Ports: A Comparative Performance Study

EPA Science Inventory

Vapor intrusion (VI) is the migration of subsurface vapors, including radon and volatile organic compounds (VOCs), from the subsurface to indoor air. The VI exposure pathway extends from the contaminant source, which can be impacted soil, non-aqueous phase liquid, or contaminated...

Liquefaction processes and systems and liquefaction process intermediate compositions

DOEpatents

Schmidt, Andrew J.; Hart, Todd R.; Billing, Justin M.; Maupin, Gary D.; Hallen, Richard T.; Anderson, Daniel B.

2014-07-12

Liquefaction processes are provided that can include: providing a biomass slurry solution having a temperature of at least 300.degree. C. at a pressure of at least 2000 psig; cooling the solution to a temperature of less than 150.degree. C.; and depressurizing the solution to release carbon dioxide from the solution and form at least part of a bio-oil foam. Liquefaction processes are also provided that can include: filtering the biomass slurry to remove particulates; and cooling and depressurizing the filtered solution to form the bio-oil foam. Liquefaction systems are provided that can include: a heated biomass slurry reaction zone maintained above 300.degree. C. and at least 2000 psig and in continuous fluid communication with a flash cooling/depressurization zone maintained below 150.degree. C. and between about 125 psig and about atmospheric pressure. Liquefaction systems are also provided that can include a foam/liquid separation system. Liquefaction process intermediate compositions are provided that can include a bio-oil foam phase separated from an aqueous biomass solids solution.

Two-mirror, three-reflection telescopes as candidates for sky surveys in ground and space applications. The MINITRUST: an active optics warping telescope for wide-field astronomy

NASA Astrophysics Data System (ADS)

Viotti, Roberto F.; La Padula, Cesare D.; Vignato, Agostino; Lemaitre, Gerard R.; Montiel, Pierre; Dohlen, Kjetil

2002-12-01

A concept based on a two-mirror, three-reflection telescope has been investigated. Its anastigmatism and flat fielded properties, the compactness and optical performances over 2-2.5 arc deg field of view, make this optical system of high interest for the development of much larger telescopes than with Schmidt designs. The 2MTRT concept is a potential candidate for sky surveys with 2-3 meter class telescopes and particularily well adapted for UV space surveys. Preliminary developments have been carried out with the construction of a 30-cm prototype on Amoretti's design, providing encouraging results. At present, a 45-cm 2MTRT prototype has been realized for ground based sky survey of NEOs, based on active optics (MINITRUST), in order to overcome the difficulty of obtaining three aspherical surfaces. The primary and tertiary lie on the same double vase substrate, and have a rest profile. The hyperbolization is carried out in situ by air depressure. The secondary, in a tulip form substrate, has been hyperbolized by elastic relaxation. The project is planned for operation in 2003.

Anisotropy in subduction zones: Insights from new source side S wave splitting measurements from India

NASA Astrophysics Data System (ADS)

Roy, Sunil K.; Kumar, M. Ravi; Davuluri, Srinagesh

2017-08-01

This study presents 106 splitting and 40 null measurements of source side anisotropy in subduction zones, utilizing direct S waves registered at two stations sited on the Indian continent, which show null shear wave splitting measurements for SKS phases. Our results suggest that trench-parallel anisotropy is dominant beneath the Philippines, Mariana, Izu-Bonin, and edge of the Java slab, while plate motion-parallel anisotropy is observed beneath the Solomon, Aegean, Japan, and Java slabs. Results from Kuril and Aleutian regions reveal trench-oblique anisotropy. We chose to interpret these observations primarily in terms of mantle flow beneath a subduction zone. While the two-dimensional (2-D) slab entrained flow model offers a simple explanation for trench-normal fast polarization azimuths (FPA), the trench-parallel FPA can be reconciled by extension due to slab rollback. The model that invokes age of the subducting lithosphere can explain anisotropy in the subslab, derived from rays recorded at the updip stations. However, when downdip stations are used, contributions from the slab and supraslab need to be considered. In Japan, anisotropy in the subslab mantle shallower than 300 km might be associated with trench-parallel mantle flow resulting in the alignment of FPA in the same direction. Anisotropy in the deeper part, above the transition zone, is probably associated with 2-D flow resulting in trench-normal FPA. Anisotropy in the Mariana Trench might be associated with trench-parallel mantle flow in the supraslab region, with similar deformation in the upper mantle and the transition zone.

Shear wave splitting and shear wave splitting tomography of the southern Puna plateau

NASA Astrophysics Data System (ADS)

Calixto, Frank J.; Robinson, Danielle; Sandvol, Eric; Kay, Suzanne; Abt, David; Fischer, Karen; Heit, Ben; Yuan, Xiaohui; Comte, Diana; Alvarado, Patricia

2014-11-01

We have investigated the seismic anisotropy beneath the Central Andean southern Puna plateau by applying shear wave splitting analysis and shear wave splitting tomography to local S waves and teleseismic SKS, SKKS and PKS phases. Overall, a very complex pattern of fast directions throughout the southern Puna plateau region and a circular pattern of fast directions around the region of the giant Cerro Galan ignimbrite complex are observed. In general, teleseismic lag times are much greater than those for local events which are interpreted to reflect a significant amount of sub and inner slab anisotropy. The complex pattern observed from shear wave splitting analysis alone is the result of a complex 3-D anisotropic structure under the southern Puna plateau. Our application of shear wave splitting tomography provides a 3-D model of anisotropy in the southern Puna plateau that shows different patterns depending on the driving mechanism of upper-mantle flow and seismic anisotropy. The trench parallel a-axes in the continental lithosphere above the slab east of 68W may be related to deformation of the overriding continental lithosphere since it is under compressive stresses which are orthogonal to the trench. The more complex pattern below the Cerro Galan ignimbrite complex and above the slab is interpreted to reflect delamination of continental lithosphere and upwelling of hot asthenosphere. The a-axes beneath the Cerro Galan, Cerro Blanco and Carachi Pampa volcanic centres at 100 km depth show some weak evidence for vertically orientated fast directions, which could be due to vertical asthenospheric flow around a delaminated block. Additionally, our splitting tomographic model shows that there is a significant amount of seismic anisotropy beneath the slab. The subslab mantle west of 68W shows roughly trench parallel horizontal a-axes that are probably driven by slab roll back and the relatively small coupling between the Nazca slab and the underlying mantle. In

Measured airtightness of an installed skylight

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

Shaw, C.Y.; Magee, R.J.; Poirier, G.F.

2000-07-01

An art gallery building had problems with moisture. Inspections using thermographic techniques suggested that air leakage through the skylights could be the main cause of the problem. The air leakage rate of an installed metal frame skylight, 26 m long x 8.5 m wide, was measured, using the balanced fan depressurization method. Also, fan depressurization tests were performed on the glazing/upstand interface on the south side of the skylight. The air leakage rates were measured through the full interface and on the west and east halves separately. The methods used for field testing of such components and the test resultsmore » are discussed.« less

Fuel Oxidizer Reaction Products (FORP) Contamination of Service Module (SM) and Release of N-nitrosodimethylamine(NDMA)in a Humid Environment from Crew EVA Suits Contaminated with FORP

NASA Technical Reports Server (NTRS)

Schmidl, William; Mikatarian, Ron; Lam, Chiu-Wing; West, Bil; Buchanan, Vanessa; Dee, Louis; Baker, David; Koontz, Steve

2004-01-01

The Service Module (SM) is an element of the Russian Segment of the International Space Station (ISS). One of the functions of the SM is to provide attitude control for the ISS using thrusters when the U.S. Control Moment Gyros (CMG's) must be desaturated. Prior to an Extravehicular Activity (EVA) on the Russian Segment, the Docking Compartment (DC1) is depressurized, as it is used as an airlock. When the DC1 is depressurized, the CMG's margin of momentum is insufficient and the SM attitude control thrusters need to fire to desaturate the CMG's. SM roll thruster firings induce contamination onto adjacent surfaces with Fuel Oxidizer Reaction Products (FORP). FORP is composed of both volatile and non-volatile components. One of the components of FORP is the potent carcinogen N-nitrosdimethylamine (NDMA). Since the EVA crewmembers often enter the area surrounding the thrusters for tasks on the aft end of the SM and when translating to other areas of the Russian Segment, the presence of FORP is a concern. This paper will discuss FORP contamination of the SM surfaces, the release of NDMA in a humid environment from crew EVA suits, if they happen to be contaminated with FORP, and the toxicological risk associated with the NDMA release.

Sensitivity and uncertainty analysis for Abreu & Johnson numerical vapor intrusion model.

PubMed

Ma, Jie; Yan, Guangxu; Li, Haiyan; Guo, Shaohui

2016-03-05

This study conducted one-at-a-time (OAT) sensitivity and uncertainty analysis for a numerical vapor intrusion model for nine input parameters, including soil porosity, soil moisture, soil air permeability, aerobic biodegradation rate, building depressurization, crack width, floor thickness, building volume, and indoor air exchange rate. Simulations were performed for three soil types (clay, silt, and sand), two source depths (3 and 8m), and two source concentrations (1 and 400 g/m(3)). Model sensitivity and uncertainty for shallow and high-concentration vapor sources (3m and 400 g/m(3)) are much smaller than for deep and low-concentration sources (8m and 1g/m(3)). For high-concentration sources, soil air permeability, indoor air exchange rate, and building depressurization (for high permeable soil like sand) are key contributors to model output uncertainty. For low-concentration sources, soil porosity, soil moisture, aerobic biodegradation rate and soil gas permeability are key contributors to model output uncertainty. Another important finding is that impacts of aerobic biodegradation on vapor intrusion potential of petroleum hydrocarbons are negligible when vapor source concentration is high, because of insufficient oxygen supply that limits aerobic biodegradation activities. Copyright © 2015 Elsevier B.V. All rights reserved.

RESEARCH BRIEFING ON DEVELOPMENT OF A SUB-SLAB AIR SAMPLING PROTOCOL

EPA Science Inventory

Vapor intrusion is defined as the migration of volatile organic compounds (VOCs) into occupied buildings from contaminated soil or ground water. EPA recently developed guidance to facilitate assessment of vapor intrusion at sites regulated by RCRA and CERCLA. The EPA guidance e...

JOHNSON AND ETTINGER (1991) VAPOR INTRUSION MODEL WITH SUB-SLAB CONCENTRATION

EPA Science Inventory

Migration of volatile chemicals from the subsurface into overlying buildings is known as vapor intrusion (VI). Under certain circumstances, people living in homes above contaminated soil or ground water may be exposed to harmful levels of these vapors. Vapor intrusion is a part...

Cyclic Activity of Mud Volcanoes: Evidences from Trinidad (SE Caribbean)

NASA Astrophysics Data System (ADS)

Deville, E.

2007-12-01

Fluid and solid transfer in mud volcanoes show different phases of activity, including catastrophic events followed by periods of relative quiescence characterized by moderate activity. This can be notably shown by historical data onshore Trinidad. Several authors have evoked a possible link between the frequencies of eruption of some mud volcanoes and seismic activity, but in Trinidad there is no direct correlation between mud eruptions and seisms. It appears that each eruptive mud volcano has its own period of catastrophic activity, and this period is highly variable from one volcano to another. The frequency of activity of mud volcanoes seems essentially controlled by local pressure regime within the sedimentary pile. At the most, a seism can, in some cases, activate an eruption close to its term. The dynamics of expulsion of the mud volcanoes during the quiescence phases has been studied notably from temperature measurements within the mud conduits. The mud temperature is concurrently controlled by, either, the gas flux (endothermic gas depressurizing induces a cooling effect), or by the mud flux (mud is a vector for convective heat transfer). Complex temperature distribution was observed in large conduits and pools. Indeed, especially in the bigger pools, the temperature distribution characterizes convective cells with an upward displacement of mud above the deep outlet, and ring-shaped rolls associated with the burial of the mud on the flanks of the pools. In simple, tube-like shaped, narrow conduits, the temperature is more regular, but we observed different types of profiles, with either downward increasing or decreasing temperatures. If the upward flow of mud would be regular, we should expect increasing temperatures and progressively decreasing gradient with depth within the conduits. However, the variable measured profiles from one place to another, as well as time-variable measured temperatures within the conduits and especially, at the base of the

PARAMETRIC ANALYSIS OF THE INSTALLATION AND OPERATING COSTS OF ACTIVE SOIL DEPRESSURIZATION SYSTEMS FOR RESIDENTIAL RADON MITIGATION

EPA Science Inventory

The report gives results of a recent analysis showing that cost- effective indoor radon reduction technology is required for houses with initial radon concentrations < 4 pCi/L, because 78-86% of the national lung cancer risk due to radon is associated with those houses. ctive soi...

Noise reduction characteristics of general aviation type dual-pane windows

NASA Technical Reports Server (NTRS)

Grosveld, F.; Navaneethan, R.; Roskam, J.

1980-01-01

The noise reduction characteristics of general-aviation-type, dual-pane windows in various configurations have been experimentally investigated. The effects of inner and outer pane thickness, spacing between the panes, edge conditions, inclination of the inner pane and depressurization of the air in between the panes are presented. The space in between the two window panes is sealed airtight in all cases. Results show that increasing the mass of a 'floating' window pane does not increase the noise reduction below the fundamental resonance frequency. It is concluded that the concept of depressurization of the air between thin (1/8 in) Plexiglas panes and application of multiple-freedom edge conditions for the inner pane are promising to reduce noise levels in general aviation airplanes.

System and method for continuous solids slurry depressurization

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

Leininger, Thomas Frederick; Steele, Raymond Douglas; Yen, Hsien-Chin William

A continuous slag processing system includes a rotating parallel disc pump, coupled to a motor and a brake. The rotating parallel disc pump includes opposing discs coupled to a shaft, an outlet configured to continuously receive a fluid at a first pressure, and an inlet configured to continuously discharge the fluid at a second pressure less than the first pressure. The rotating parallel disc pump is configurable in a reverse-acting pump mode and a letdown turbine mode. The motor is configured to drive the opposing discs about the shaft and against a flow of the fluid to control a differencemore » between the first pressure and the second pressure in the reverse-acting pump mode. The brake is configured to resist rotation of the opposing discs about the shaft to control the difference between the first pressure and the second pressure in the letdown turbine mode.« less

System and method for continuous solids slurry depressurization

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

Leininger, Thomas Frederick; Steele, Raymond Douglas; Cordes, Stephen Michael

A system includes a first pump having a first outlet and a first inlet, and a controller. The first pump is configured to continuously receive a flow of a slurry into the first outlet at a first pressure and to continuously discharge the flow of the slurry from the first inlet at a second pressure less than the first pressure. The controller is configured to control a first speed of the first pump against the flow of the slurry based at least in part on the first pressure, wherein the first speed of the first pump is configured to resistmore » a backflow of the slurry from the first outlet to the first inlet.« less

Land subsidence associated with hydrocarbon production, Texas Gulf Coast

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

Kreitler, C.W.; White, W.A.; Akhter, M.S.

1988-01-01

Although ground-water withdrawal has been the predominant cause of land subsidence in the Texas Gulf Coast, localized subsidence and faulting have also resulted from hydrocarbon production. Subsidence was documented as early as the 1920s over the Goose Creek field. Since then, subsidence and/or faulting have been identified over the Saxet, South Houston, Chocolate Bayou, Hastings, Alco-Mag, Clinton, Mykawa, Blue Ridge, Webster, and Caplen oil fields. Oil-production-related subsidence over these fields generally creates few environmental or engineering problems. One exception is the subsidence and faulting over the Caplen oil field on Bolivar Peninsula, where more than 1,000 ac of saltwater marshmore » has been replaced by subaqueous flats. Subsidence may be occurring over other fields but has not been identified because of limited releveled benchmark data. An evaluation of drill-stem and bottom-hole pressure data for the Frio Formation in Texas indicates extensive depressurization presumably from hydrocarbon production. Nearly 12,000 measurements from a pressure data base of 17,000 measurements indicate some depressurization. Some of the Frio zones have pressure declines of more than 1,500 psi from original hydrostatic conditions. Subsidence and faulting may be associated with these fields in the Frio as well as other Tertiary formations where extensive hydrocarbon production and subsequent depressurization have occurred.« less

Assessment of the 3He pressure inside the CABRI transient rods - Development of a surrogate model based on measurements and complementary CFD calculations

NASA Astrophysics Data System (ADS)

Clamens, Olivier; Lecerf, Johann; Hudelot, Jean-Pascal; Duc, Bertrand; Cadiou, Thierry; Blaise, Patrick; Biard, Bruno

2018-01-01

CABRI is an experimental pulse reactor, funded by the French Nuclear Safety and Radioprotection Institute (IRSN) and operated by CEA at the Cadarache research center. It is designed to study fuel behavior under RIA conditions. In order to produce the power transients, reactivity is injected by depressurization of a neutron absorber (3He) situated in transient rods inside the reactor core. The shapes of power transients depend on the total amount of reactivity injected and on the injection speed. The injected reactivity can be calculated by conversion of the 3He gas density into units of reactivity. So, it is of upmost importance to properly master gas density evolution in transient rods during a power transient. The 3He depressurization was studied by CFD calculations and completed with measurements using pressure transducers. The CFD calculations show that the density evolution is slower than the pressure drop. Surrogate models were built based on CFD calculations and validated against preliminary tests in the CABRI transient system. Studies also show that it is harder to predict the depressurization during the power transients because of neutron/3He capture reactions that induce a gas heating. This phenomenon can be studied by a multiphysics approach based on reaction rate calculation thanks to Monte Carlo code and study the resulting heating effect with the validated CFD simulation.

Analysis of formation pressure test results in the Mount Elbert methane hydrate reservoir through numerical simulation

USGS Publications Warehouse

Kurihara, M.; Sato, A.; Funatsu, K.; Ouchi, H.; Masuda, Y.; Narita, H.; Collett, T.S.

2011-01-01

Targeting the methane hydrate (MH) bearing units C and D at the Mount Elbert prospect on the Alaska North Slope, four MDT (Modular Dynamic Formation Tester) tests were conducted in February 2007. The C2 MDT test was selected for history matching simulation in the MH Simulator Code Comparison Study. Through history matching simulation, the physical and chemical properties of the unit C were adjusted, which suggested the most likely reservoir properties of this unit. Based on these properties thus tuned, the numerical models replicating "Mount Elbert C2 zone like reservoir" "PBU L-Pad like reservoir" and "PBU L-Pad down dip like reservoir" were constructed. The long term production performances of wells in these reservoirs were then forecasted assuming the MH dissociation and production by the methods of depressurization, combination of depressurization and wellbore heating, and hot water huff and puff. The predicted cumulative gas production ranges from 2.16??106m3/well to 8.22??108m3/well depending mainly on the initial temperature of the reservoir and on the production method.This paper describes the details of modeling and history matching simulation. This paper also presents the results of the examinations on the effects of reservoir properties on MH dissociation and production performances under the application of the depressurization and thermal methods. ?? 2010 Elsevier Ltd.

Hydro-bio-geomechanical properties of hydrate-bearing sediments from Nankai Trough

USGS Publications Warehouse

Santamarina, J.C.; Dai, Shifeng; Terzariol, M.; Jang, Jeonghwan; Waite, William F.; Winters, William J.; Nagao, J.; Yoneda, J.; Konno, Y.; Fujii, T.; Suzuki, K.

2015-01-01

Natural hydrate-bearing sediments from the Nankai Trough, offshore Japan, were studied using the Pressure Core Characterization Tools (PCCTs) to obtain geomechanical, hydrological, electrical, and biological properties under in situ pressure, temperature, and restored effective stress conditions. Measurement results, combined with index-property data and analytical physics-based models, provide unique insight into hydrate-bearing sediments in situ. Tested cores contain some silty-sands, but are predominantly sandy- and clayey-silts. Hydrate saturations Sh range from 0.15 to 0.74, with significant concentrations in the silty-sands. Wave velocity and flexible-wall permeameter measurements on never-depressurized pressure-core sediments suggest hydrates in the coarser-grained zones, the silty-sands where Sh exceeds 0.4, contribute to soil-skeletal stability and are load-bearing. In the sandy- and clayey-silts, where Sh < 0.4, the state of effective stress and stress history are significant factors determining sediment stiffness. Controlled depressurization tests show that hydrate dissociation occurs too quickly to maintain thermodynamic equilibrium, and pressure–temperature conditions track the hydrate stability boundary in pure-water, rather than that in seawater, in spite of both the in situ pore water and the water used to maintain specimen pore pressure prior to dissociation being saline. Hydrate dissociation accompanied with fines migration caused up to 2.4% vertical strain contraction. The first-ever direct shear measurements on never-depressurized pressure-core specimens show hydrate-bearing sediments have higher sediment strength and peak friction angle than post-dissociation sediments, but the residual friction angle remains the same in both cases. Permeability measurements made before and after hydrate dissociation demonstrate that water permeability increases after dissociation, but the gain is limited by the transition from hydrate saturation

Effect of Mineral Dissolution/Precipitation and CO2 Exsolution on CO2 transport in Geological Carbon Storage.

PubMed

Xu, Ruina; Li, Rong; Ma, Jin; He, Di; Jiang, Peixue

2017-09-19

Geological carbon sequestration (GCS) in deep saline aquifers is an effective means for storing carbon dioxide to address global climate change. As the time after injection increases, the safety of storage increases as the CO 2 transforms from a separate phase to CO 2 (aq) and HCO 3 - by dissolution and then to carbonates by mineral dissolution. However, subsequent depressurization could lead to dissolved CO 2 (aq) escaping from the formation water and creating a new separate phase which may reduce the GCS system safety. The mineral dissolution and the CO 2 exsolution and mineral precipitation during depressurization change the morphology, porosity, and permeability of the porous rock medium, which then affects the two-phase flow of the CO 2 and formation water. A better understanding of these effects on the CO 2 -water two-phase flow will improve predictions of the long-term CO 2 storage reliability, especially the impact of depressurization on the long-term stability. In this Account, we summarize our recent work on the effect of CO 2 exsolution and mineral dissolution/precipitation on CO 2 transport in GCS reservoirs. We place emphasis on understanding the behavior and transformation of the carbon components in the reservoir, including CO 2 (sc/g), CO 2 (aq), HCO 3 - , and carbonate minerals (calcite and dolomite), highlight their transport and mobility by coupled geochemical and two-phase flow processes, and consider the implications of these transport mechanisms on estimates of the long-term safety of GCS. We describe experimental and numerical pore- and core-scale methods used in our lab in conjunction with industrial and international partners to investigate these effects. Experimental results show how mineral dissolution affects permeability, capillary pressure, and relative permeability, which are important phenomena affecting the input parameters for reservoir flow modeling. The porosity and the absolute permeability increase when CO 2 dissolved water is

CFD Analyses of Air-Ingress Accident for VHTRs

NASA Astrophysics Data System (ADS)

Ham, Tae Kyu

The Very High Temperature Reactor (VHTR) is one of six proposed Generation-IV concepts for the next generation of nuclear powered plants. The VHTR is advantageous because it is able to operate at very high temperatures, thus producing highly efficient electrical generation and hydrogen production. A critical safety event of the VHTR is a loss-of-coolant accident. This accident is initiated, in its worst-case scenario, by a double-ended guillotine break of the cross vessel that connects the reactor vessel and the power conversion unit. Following the depressurization process, the air (i.e., the air and helium mixture) in the reactor cavity could enter the reactor core causing an air-ingress event. In the event of air-ingress into the reactor core, the high-temperature in-core graphite structures will chemically react with the air and could lose their structural integrity. We designed a 1/8th scaled-down test facility to develop an experimental database for studying the mechanisms involved in the air-ingress phenomenon. The current research focuses on the analysis of the air-ingress phenomenon using the computational fluid dynamics (CFD) tool ANSYS FLUENT for better understanding of the air-ingress phenomenon. The anticipated key steps in the air-ingress scenario for guillotine break of VHTR cross vessel are: 1) depressurization; 2) density-driven stratified flow; 3) local hot plenum natural circulation; 4) diffusion into the reactor core; and 5) global natural circulation. However, the OSU air-ingress test facility covers the time from depressurization to local hot plenum natural circulation. Prior to beginning the CFD simulations for the OSU air-ingress test facility, benchmark studies for the mechanisms which are related to the air-ingress accident, were performed to decide the appropriate physical models for the accident analysis. In addition, preliminary experiments were performed with a simplified 1/30th scaled down acrylic set-up to understand the air

KSC-04PD-1133

NASA Technical Reports Server (NTRS)

2004-01-01

KENNEDY SPACE CENTER, FLA. -- Technicians in the Orbiter Processing Facility attach a crane to Discoverys airlock before lifting it for installation. The airlock is located inside the orbiters payload bay and is sized to accommodate two fully suited flight crew members simultaneously. Support functions include airlock depressurization and repressurization, extravehicular activity equipment recharge, liquid-cooled garment water cooling, EVA equipment checkout, and communications. Discovery is designated as the Return to Flight vehicle for mission STS-114, no earlier than March 2005. STS-114 mission is Logistics Flight 1, which is scheduled to deliver supplies and equipment plus the external stowage platform to the International Space Station.

Hydrologic hydrochemical characterization of texas frio formation used for deep-well injection of chemical wastes

NASA Astrophysics Data System (ADS)

Kreitler, Charles W.; Akhter, M. Saleem; Donnelly, Andrew C. A.

1990-09-01

Hydrologic hydrochemical investigations were conducted to determine the long-term fate of hazardous chemical waste disposed in the Texas Gulf Coast Tertiary formations by deep-well injection. The study focused on the hydrostatic section of the Frio Formation because it is the host of a very large volume of injected waste and because large data bases of formation pressures and water chemistry are available. Three hydrologic regimes exist within the Frio Formation: a shallow fresh to moderately saline water section in the upper 3,000 4,000 ft (914 1,219 m); an underlying 4,000- to 5,000-ft-thick (1,219- to 1,524-m) section with moderate to high salinities: and a deeper overpressured section with moderate to high salinities. The upper two sections are normally pressured and reflect either freshwater or brine hydrostatic pressure gradients. Geopressured conditions are encountered as shallow as 6,000 ft (1,829 m). The complexity of the hydrologic environment is enhanced due to extensive depressurization in the 4,000- to 8,000-ft-depth (1,219- to 2,438-m) interval, which presumably results from the estimated production of over 10 billion barrels (208 × 106 m3) of oil equivalent and associated brines from the Frio in the past 50 yr. Because of the higher fluid density and general depressurization in the brine hydrostatic section, upward migration of these brines to shallow fresh groundwaters should not occur. Depressured oil and gas fields, however, may become sinks for the injected chemical wastes. Water samples appear to be in approximate oxygen isotopic equilibrium with the rock matrix, suggesting that active recharge of the Frio by continental waters is not occurring. In the northern Texas Gulf Coast region salt dome dissolution is a prime process controlling water chemistry. In the central and southern Frio Formation, brines from the deeper geopressured section may be leaking into the hydrostatic section. The lack of organic acids and the alteration of Frio oils

INDOOR RADON REDUCTION IN CRAWL-SPACE HOUSES: A REVIEW OF ALTERNATIVE APPROACHES

EPA Science Inventory

An analysis has been completed of the performance, mechanisms, and costs of alternative technologies for preventing radon entry into the living areas of houses having crawl-space foundations. Sub-membrane depressurization (SMD) is consistently the most effective technique, often ...

Hip chondrolabral mechanics during activities of daily living: Role of the labrum and interstitial fluid pressurization.

PubMed

Todd, Jocelyn N; Maak, Travis G; Ateshian, Gerard A; Maas, Steve A; Weiss, Jeffrey A

2018-03-01

Osteoarthritis of the hip can result from mechanical factors, which can be studied using finite element (FE) analysis. FE studies of the hip often assume there is no significant loss of fluid pressurization in the articular cartilage during simulated activities and approximate the material as incompressible and elastic. This study examined the conditions under which interstitial fluid load support remains sustained during physiological motions, as well as the role of the labrum in maintaining fluid load support and the effect of its presence on the solid phase of the surrounding cartilage. We found that dynamic motions of gait and squatting maintained consistent fluid load support between cycles, while static single-leg stance experienced slight fluid depressurization with significant reduction of solid phase stress and strain. Presence of the labrum did not significantly influence fluid load support within the articular cartilage, but prevented deformation at the cartilage edge, leading to lower stress and strain conditions in the cartilage. A morphologically accurate representation of collagen fibril orientation through the thickness of the articular cartilage was not necessary to predict fluid load support. However, comparison with simplified fibril reinforcement underscored the physiological importance. The results of this study demonstrate that an elastic incompressible material approximation is reasonable for modeling a limited number of cyclic motions of gait and squatting without significant loss of accuracy, but is not appropriate for static motions or numerous repeated motions. Additionally, effects seen from removal of the labrum motivate evaluation of labral reattachment strategies in the context of labral repair. Copyright © 2018 Elsevier Ltd. All rights reserved.

Overview of the 2006-2008 JOGMEC/NRCan/Aurora Mallik Gas Hydrate Production Test Program

NASA Astrophysics Data System (ADS)

Yamamoto, K.; Dallimore, S. R.

2008-12-01

During the winters of 2007 and 2008 the Japan Oil, Gas and Metals National Corporation (JOGMEC) and Natural Resources Canada (NRCan), with Aurora Research Institute as the operator, carried out an on-shore gas hydrate production test program at the Mallik site, Mackenzie Delta, Northwest Territories, Canada. The prime objective of the program was to verify the feasibility of depressurization technique by drawing down the formation pressure across a 12m perforated gas hydrate bearing section. This project was the second full scale production test at this site following the 2002 Japex/JNOC/GSC et al Mallik research program in which seven participants organizatinos from five countries undertook a thermal test using hot water circulation Field work in 2007 was devoted to establishing a production test well, installing monitoring devices outside of casing, conducting base line geophysical studies and undertaking a short test to gain practical experience prior to longer term testing planned for 2008 . Hydrate-dissociated gas was produced to surface by depressurization achieved by lowering the fluid level with a dowhole pump. However, the operation was terminated 60 hours after the start of the pumping mainly due to sand production problems. In spite of the short period (12.5 hours of ellapsed pumping time), at least 830m3 of the gas was produced and accumulated in the borehole. Sand screens were installed across the perforated interval at the bottom hole for the 2008 program to overcome operational problems encountered in 2007 and achieve sustainable gas production. Stable bottom hole flowing pressures were successfully achieved during a 6 day test with continuous pump operation. Sustained gas production was achieved with rates between 2000- 4000m3/day and cummulative gas volume in the surface of approximately 13,000m3. Temperature and pressure data measured at the bottom hole and gas and water production rates gave positive evidence for the high efficiency of gas

TESTING OF INDOOR RADON REDUCTION TECHNIQUES IN 19 MARYLAND HOUSES

EPA Science Inventory

The report gives results of testing of indoor radon reduction techniques in 19 existing houses in Maryland. The focus was on passive measures: various passive soil depressurization methods, where natural wind and temperature effects are utilized to develop suction in the system; ...

TEST CELL STUDIES OF RADON ENTRY

EPA Science Inventory

The report gives results of a study to contrast the effectiveness of slab-in-stem wall (SSW) with floating slab (FS) construction practices, to measure radon transport and entry for model testing, to develop protocols relevant to depressurized radon measurements, and to determine...

Sub-slab vs. Near-slab Soil Vapor Profiles at a Chlorinated Solvent Site

EPA Science Inventory

A critical issue in assessing the vapor intrusion pathway is the distribution and migration of VOCs from the subsurface source to the near surface environment. Therefore, EPA/ORD funded a research project with the primary goal of comparing vertical profiles of soil gas concentrat...

Should we pretreat solid waste prior to anaerobic digestion? An assessment of its environmental cost.

PubMed

Carballa, Marta; Duran, Cecilia; Hospido, Almudena

2011-12-15

Many studies have shown the effectiveness of pretreatments prior to anaerobic digestion of solid wastes, but to our knowledge, none analyzes their environmental consequences/costs. In this work, seven different pretreatments applied to two types of waste (kitchen waste and sewage sludge) have been environmentally evaluated by using life cycle assessment (LCA) methodology. The results show that the environmental burdens associated to the application of pretreatments prior to anaerobic digestion cannot be excluded. Among the options tested, the pressurize-depressurize and chemical (acid or alkaline) pretreatments could be recommended on the basis of their beneficial net environmental performance, while thermal and ozonation alternatives require energy efficiency optimization to reduce their environmental burdens. Reconciling operational, economic and environmental aspects in a holistic approach for the selection of the most sustainable option, mechanical (e.g., pressurize-depressurize) and chemical methods appear to be the most appropriate alternatives at this stage.

MODELNG RADON ENTRY INTO FLORIDA HOUSES WITH CONCRETE SLABS AND CONCRETE-BLOCK STEM WALLS, FLORIDA RADON RESEARCH PROGRAM

EPA Science Inventory

The report discusses results of modeling radon entry into a typical Florida house whose interior is slightly depressurized. he model predicts that the total radon entry rate is relatively low unless the soil or backfill permeability or radium content is high. ost of the factors c...

10 CFR 50.34 - Contents of applications; technical information.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., and a program to ensure that the results of these studies are factored into the final design of the... assessment study to determine the optimum automatic depressurization system (ADS) design modifications that... capability for containment purging/venting designed to minimize the purging time consistent with ALARA...

10 CFR 50.34 - Contents of applications; technical information.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., and a program to ensure that the results of these studies are factored into the final design of the... assessment study to determine the optimum automatic depressurization system (ADS) design modifications that... capability for containment purging/venting designed to minimize the purging time consistent with ALARA...

Assessment of Literature Related to Combustion Appliance Venting Systems

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

Rapp, V. H.; Less, B. D.; Singer, B. C.

In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents theirmore » technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.« less

Recovery of nitrogen and light hydrocarbons from polyalkene purge gas

DOEpatents

Zwilling, Daniel Patrick; Golden, Timothy Christoph; Weist, Jr., Edward Landis; Ludwig, Keith Alan

2003-06-10

A method for the separation of a gas mixture comprises (a) obtaining a feed gas mixture comprising nitrogen and at least one hydrocarbon having two to six carbon atoms; (b) introducing the feed gas mixture at a temperature of about 60.degree. F. to about 105.degree. F. into an adsorbent bed containing adsorbent material which selectively adsorbs the hydrocarbon, and withdrawing from the adsorbent bed an effluent gas enriched in nitrogen; (c) discontinuing the flow of the feed gas mixture into the adsorbent bed and depressurizing the adsorbent bed by withdrawing depressurization gas therefrom; (d) purging the adsorbent bed by introducing a purge gas into the bed and withdrawing therefrom an effluent gas comprising the hydrocarbon, wherein the purge gas contains nitrogen at a concentration higher than that of the nitrogen in the feed gas mixture; (e) pressurizing the adsorbent bed by introducing pressurization gas into the bed; and (f) repeating (b) through (e) in a cyclic manner.

Decay Heat Removal in GEN IV Gas-Cooled Fast Reactors

DOE PAGES

Cheng, Lap-Yan; Wei, Thomas Y. C.

2009-01-01

The safety goal of the current designs of advanced high-temperature thermal gas-cooled reactors (HTRs) is that no core meltdown would occur in a depressurization event with a combination of concurrent safety system failures. This study focused on the analysis of passive decay heat removal (DHR) in a GEN IV direct-cycle gas-cooled fast reactor (GFR) which is based on the technology developments of the HTRs. Given the different criteria and design characteristics of the GFR, an approach different from that taken for the HTRs for passive DHR would have to be explored. Different design options based on maintaining core flow weremore » evaluated by performing transient analysis of a depressurization accident using the system code RELAP5-3D. The study also reviewed the conceptual design of autonomous systems for shutdown decay heat removal and recommends that future work in this area should be focused on the potential for Brayton cycle DHRs.« less

In situ studies of microbial inactivation during high pressure processing

NASA Astrophysics Data System (ADS)

Maldonado, Jose Antonio; Schaffner, Donald W.; Cuitiño, Alberto M.; Karwe, Mukund V.

2016-01-01

High pressure processing (HPP) has been shown to reduce microbial concentration in foods. The mechanisms of microbial inactivation by HPP have been associated with damage to cell membranes. The real-time response of bacteria to HPP was measured to elucidate the mechanisms of inactivation, which can aid in designing more effective processes. Different pressure cycling conditions were used to expose Enterobacter aerogenes cells to HPP. Propidium iodide (PI) was used as a probe, which fluoresces after penetrating cells with damaged membranes and binding with nucleic acids. A HPP vessel with sapphire windows was used for measuring fluorescence in situ. Membrane damage was detected during pressurization and hold time, but not during depressurization. The drop in fluorescence was larger than expected after pressure cycles at higher pressure and longer times. This indicated possible reversible disassociation of ribosomes resulting in additional binding of PI to exposed RNA under pressure and its release after depressurization.

On Small Disturbance Ascent Vent Behavior

NASA Technical Reports Server (NTRS)

Woronowicz, Michael

2015-01-01

As a spacecraft undergoes ascent in a launch vehicle, its ambient pressure environment transitions from one atmosphere to high vacuum in a matter of a few minutes. Venting of internal cavities is necessary to prevent the buildup of pressure differentials across cavity walls. These pressure differentials are often restricted to low levels to prevent violation of container integrity. Such vents usually consist of fixed orifices, ducts, or combinations of both. Duct conductance behavior is fundamentally different from that for orifices in pressure driven flows governing the launch vehicle ascent depressurization environment. Duct conductance is governed by the average pressure across its length, while orifice conductance is dictated by a pressure ratio. Hence, one cannot define a valid equivalent orifice for a given duct across a range of pressure levels. This presentation discusses development of expressions for these two types of vent elements in the limit of small pressure differentials, explores conditions for their validity, and compares their features regarding ascent depressurization performance.

76 FR 64857 - Airworthiness Directives; Bombardier, Inc. Model BD-100-1A10 (Challenger 300) Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-19

..., deformation was found at the neck of the pressure regulator body on the oxygen Cylinder and Regulator.... This may cause elongation of the pressure regulator neck, which could result in rupture of the oxygen cylinder and in the case of cabin depressurization, oxygen not being available when required. * * * * * The...

Encapsulation of lutein in liposomes using supercritical carbon dioxide.

PubMed

Zhao, Lisha; Temelli, Feral; Curtis, Jonathan M; Chen, Lingyun

2017-10-01

Liposomes loaded with lutein were prepared utilizing supercritical carbon dioxide (SC-CO 2 ). The effects of pressure, depressurization rate, temperature and lutein-to-lipid ratio on particle size distribution, zeta potential, encapsulation efficiency (EE), bioactive loading, morphology, phase transition and crystallinity were investigated. Liposomes prepared by the SC-CO 2 method had a particle size of 147.6±1.9nm-195.4±2.3nm, an encapsulation efficiency of 56.7±0.7%-97.0±0.8% and a zeta potential of -54.5±1.2mV to -61.7±0.6mV. A higher pressure (200-300bar) and depressurization rate (90-200bar/min) promoted a higher encapsulation of lutein whereas the lutein-to-lipid ratio had the dominant effect on the morphology of vesicles along with size distribution and EE. X-ray diffraction data implied a substantial drop in the crystallinity of lutein upon its redistribution in the liposome membranes. Differential scanning calorimetry indicated a broadened phase transition upon the simultaneous rearrangement of lutein and phospholipid molecules into liposomal vesicles. The SC-CO 2 method resulted in particle characteristics highly associated with the ability of CO 2 to disperse phospholipids and lutein molecules. It offers a promising approach to use dense phase CO 2 to homogenize hydrophobic or amphiphilic aggregates suspended in an aqueous medium and regulate the vesicular characteristics via pressure and depressurization rate. The SC-CO 2 method has potential for scalable production of liposomal nanovesicles with desirable characteristics and free of organic solvents. Copyright © 2017 Elsevier Ltd. All rights reserved.

76 FR 82207 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-30

... the flightcrew due to hypoxia (lack of oxygen in the body), and consequent loss of control of the... not aware of cabin depressurization. The flightcrew also were not aware that passenger oxygen masks... flightcrew due to hypoxia (lack of oxygen in the body), and consequent loss of control of the airplane...

Modeling of molecular and particulate transport in dry spent nuclear fuel canisters

NASA Astrophysics Data System (ADS)

Casella, Andrew M.

2007-09-01

The transportation and storage of spent nuclear fuel is one of the prominent issues facing the commercial nuclear industry today, as there is still no general consensus regarding the near- and long-term strategy for managing the back-end of the nuclear fuel cycle. The debate continues over whether the fuel cycle should remain open, in which case spent fuel will be stored at on-site reactor facilities, interim facilities, or a geologic repository; or if the fuel cycle should be closed, in which case spent fuel will be recycled. Currently, commercial spent nuclear fuel is stored at on-site reactor facilities either in pools or in dry storage containers. Increasingly, spent fuel is being moved to dry storage containers due to decreased costs relative to pools. As the number of dry spent fuel containers increases and the roles they play in the nuclear fuel cycle increase, more regulations will be enacted to ensure that they function properly. Accordingly, they will have to be carefully analyzed for normal conditions, as well as any off-normal conditions of concern. This thesis addresses the phenomena associated with one such concern; the formation of a microscopic through-wall breach in a dry storage container. Particular emphasis is placed on the depressurization of the canister, release of radioactivity, and plugging of the breach due to deposition of suspended particulates. The depressurization of a dry storage container upon the formation of a breach depends on the temperature and quantity of the fill gas, the pressure differential across the breach, and the size of the breach. The first model constructed in this thesis is capable of determining the depressurization time for a breached container as long as the associated parameters just identified allow for laminar flow through the breach. The parameters can be manipulated to quantitatively determine their effect on depressurization. This model is expanded to account for the presence of suspended particles. If

Sub-slab vs. Near-slab Soil Vapor Profiles at a Chlorinated Solvent Site (1)

EPA Science Inventory

A critical issue in assessing the vapor intrusion pathway is the distribution and migration of VOCs from the subsurface source to the near surface environment. Of particular importance is the influence of a slab. Therefore, EPA/ORD is funding a research program with the primary...

Recent Ground Hold and Rapid Depressurization Testing of Multilayer Systems

NASA Technical Reports Server (NTRS)

Johnson, Wesley L.

2014-01-01

In the development of flight insulation systems for large cryogenic orbital storage (spray on foam and multilayer insulation), testing need include all environments that are experienced during flight. While large efforts have been expended on studying, bounding, and modeling the orbital performance of the insulation systems, little effort has been expended on the ground hold and ascent phases of a mission. Historical cryogenic in-space systems that have flown have been able to ignore these phases of flight due to the insulation system being within a vacuum jacket. In the development phase of the Nuclear Mars Vehicle and the Shuttle Nuclear Vehicle, several insulation systems were evaluated for the full mission cycle. Since that time there had been minimal work on these phases of flight until the Constellation program began investigating cryogenic service modules and long duration upper stages. With the inception of the Cryogenic Propellant Storage and Transfer Technology Demonstration Mission, a specific need was seen for the data and as such, several tests were added to the Cryogenic Boil-off Reduction System liquid hydrogen test matrix to provide more data on a insulation system. Testing was attempted with both gaseous nitrogen (GN2) and gaseous helium (GHe) backfills. The initial tests with nitrogen backfill were not successfully completed due to nitrogen liquefaction and solidification preventing the rapid pumpdown of the vacuum chamber. Subsequent helium backfill tests were successful and showed minimal degradation. The results are compared to the historical data.

Modelling the effects of ice-sheet activity on CO2 outgassing by Icelandic volcanoes

NASA Astrophysics Data System (ADS)

Armitage, J. J.; Ferguson, D.; Petersen, K. D.; Creyts, T. T.

2017-12-01

Glacial cycles may play a significant role in mediating the flux of magmatic CO2 between the Earth's mantle and atmosphere. In Iceland, it is thought that late-Pleistocene deglaciation led to a significant volcanic pulse, evidenced by increased post-glacial lava volumes and changes in melt chemistry consistent with depressurization. Investigating the extent to which glacial activity may have affected volcanic CO2 emissions from Iceland, and crucially over what timescale, requires detailed knowledge of how the magma system responded to the growth and collapse of the ice-sheet before and after the LGM. To investigate this, we coupled a model of magma generation and transport with a history of ice-sheet activity. Our results show that the emplacement and removal of the LGM ice-sheet likely led to two significant pulses of magmatic CO2. The first, and most significant of these, is associated with ice-sheet growth and occurs as the magma system recovers from glacial loading. This recovery happens from the base of the melting region upwards, producing a pulse of CO2 rich magma that is predicted to reach the surface around 20 ka after the loading event, close in time to the LGM. The second peak in CO2 output occurs abruptly following deglaciation as a consequence of increased rates of melt generation and transport in the shallow mantle. Although these post-glacial melts are relatively depleted in CO2, the increase in magma flux leads to a short-lived period of elevated CO2 emissions. Our results therefore suggest a negative feedback, whereby ice-sheet growth produces a delayed pulse of magmatic CO2, which, in addition to increased geothermal heat flux, may contribute towards driving deglaciation, which itself then causes further magmatism and CO2 outgassing. This model is consistent with the seismic structure of the asthenosphere below Iceland, and the established compositional and volumetric trends for sub- and post-glacial volcanism in Iceland. These trends show that

Best-estimate coupled RELAP/CONTAIN analysis of inadvertent BWR ADS valve opening transient

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

Feltus, M.A.; Muftuoglu, A.K.

1993-01-01

Noncondensible gases may become dissolved in boiling water reactor (BWR) water-level instrumentation during normal operations. Any dissolved noncondensible gases inside these water columns may come out of solution during rapid depressurization events and displace water from the reference leg piping, resulting in a false high level. Significant errors in water-level indication are not expected to occur until the reactor pressure vessel (RPV) pressure has dropped below [approximately]450 psig. These water level errors may cause a delay or failure in emergency core cooling system (ECCS) actuation. The RPV water level is monitored using the pressure of a water column having amore » varying height (reactor water level) that is compared to the pressure of a water column maintained at a constant height (reference level). The reference legs have small-diameter pipes with varying lengths that provide a constant head of water and are located outside the drywell. The amount of noncondensible gases dissolved in each reference leg is very dependent on the amount of leakage from the reference leg and its geometry and interaction of the reactor coolant system with the containment, i.e., torus or suppression pool, and reactor building. If a rapid depressurization causes an erroneously high water level, preventing automatic ECCS actuation, it becomes important to determine if there would be other adequate indications for operator response. In the postulated inadvertent opening of all seven automatic depressurization system (ADS) valves, the ECCS signal on high drywell pressure would be circumvented because the ADS valves discharge directly into the suppression pool. A best-estimate analysis of such an inadvertent opening of all ADS valves would have to consider the thermal-hydraulic coupling between the pool, drywell, reactor building, and RPV.« less

Scaling and design analyses of a scaled-down, high-temperature test facility for experimental investigation of the initial stages of a VHTR air-ingress accident

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

Arcilesi, David J.; Ham, Tae Kyu; Kim, In Hun

2015-07-01

A critical event in the safety analysis of the very high-temperature gas-cooled reactor (VHTR) is an air-ingress accident. This accident is initiated, in its worst case scenario, by a double-ended guillotine break of the coaxial cross vessel, which leads to a rapid reactor vessel depressurization. In a VHTR, the reactor vessel is located within a reactor cavity that is filled with air during normal operating conditions. Following the vessel depressurization, the dominant mode of ingress of an air–helium mixture into the reactor vessel will either be molecular diffusion or density-driven stratified flow. The mode of ingress is hypothesized to dependmore » largely on the break conditions of the cross vessel. Since the time scales of these two ingress phenomena differ by orders of magnitude, it is imperative to understand under which conditions each of these mechanisms will dominate in the air ingress process. Computer models have been developed to analyze this type of accident scenario. There are, however, limited experimental data available to understand the phenomenology of the air-ingress accident and to validate these models. Therefore, there is a need to design and construct a scaled-down experimental test facility to simulate the air-ingress accident scenarios and to collect experimental data. The current paper focuses on the analyses performed for the design and operation of a 1/8th geometric scale (by height and diameter), high-temperature test facility. A geometric scaling analysis for the VHTR, a time scale analysis of the air-ingress phenomenon, a transient depressurization analysis of the reactor vessel, a hydraulic similarity analysis of the test facility, a heat transfer characterization of the hot plenum, a power scaling analysis for the reactor system, and a design analysis of the containment vessel are discussed.« less

Surface deformations as indicators of deep ebullition fluxes in a large northern peatland

USGS Publications Warehouse

Glaser, P.H.; Chanton, J.P.; Morin, P.; Rosenberry, D.O.; Siegel, D.I.; Ruud, O.; Chasar, L.I.; Reeve, A.S.

2004-01-01

Peatlands deform elastically during precipitation cycles by small (??3 cm) oscillations in surface elevation. In contrast, we used a Global Positioning System network to measure larger oscillations that exceeded 20 cm over periods of 4-12 hours during two seasonal droughts at a bog and fen site in northern Minnesota. The second summer drought also triggered 19 depressuring cycles in an overpressured stratum under the bog site. The synchronicity between the largest surface deformations and the depressuring cycles indicates that both phenomena are produced by the episodic release of large volumes of gas from deep semi-elastic compartments confined by dense wood layers. We calculate that the three largest surface deformations were associated with the release of 136 g CH4 m-2, which exceeds by an order of magnitude the annual average chamber fluxes measured at this site. Ebullition of gas from the deep peat may therefore be a large and previously unrecognized source of radiocarbon depleted methane emissions from northern peatlands. Copyright 2004 by the American Geophysical Union.

Preparation of Silica Aerogel from TEOS

PubMed

Tamon; Kitamura; Okazaki

1998-01-15

Silica alcogels were synthesized by the sol-gel polymerization of tetraethylorthosilicate (TEOS). In the synthesis, HCl and NH3 were used as hydrolysis and condensation catalysts. The gelation time became short and the visible light transmittance increased with increasing the amount of HCl or lengthening the hydrolysis time. The alcogels were dried under supercritical conditions with carbon dioxide, and silica aerogels were obtained. As a result of characterization by visible light transmission and N2 adsorption, the aerogels are mesoporous materials with high surface areas. The experimental results suggest that the aerogel properties are not influenced by the drying conditions such as extraction temperature, extraction time, depressurizing temperature, and depressurizing rate. On the other hand, the properties are changed under the conditions of sol-gel polymerization. In the preparation of highly transparent aerogels with high surface areas and large pore volumes, it is necessary to synthesize highly transparent alcogels. It is found that the visible light transmittance of alcogels is an index for preparing aerogels from TEOS. Copyright 1998 Academic Press. Copyright 1998Academic Press

Broadband measurements of the sources of explosions at Stromboli Volcano, Italy

USGS Publications Warehouse

Chouet, B.; Saccorotti, G.; Dawson, P.; Martini, M.; Scarpa, R.; De Luca, G.; Milana, G.; Cattaneo, M.

1999-01-01

During September-October 1997, 21 three-component broadband seismometers were deployed on Stromboli Volcano at radial distances of 0.3-2.2 km from the active crater to investigate the source mechanisms of Strombolian explosions. In the 2-50 s band, the very-long period (VLP) signals associated with explosions are consistent with two stationary sources repeatedly activated in time. VLP particle motions are essentially linear and analyses of semblance and particle motions are consistent with a source centroid offset 300 m beneath and 300 m northwest of the active vents. Similar VLP waveforms are observed at all 21 stations, indicating that the seismograms are source-dominated. The VLP ground displacement response to each explosion may be qualitatively interpreted as: (1) pressurization of the conduit associated with the ascent of a slug of gas; (2) depressurization of the conduit in response to mass withdrawal during the eruption; and (3) repressurization of the conduit associated with the replenishment of the source with fluid. Copyright 1999 by the American Geophysical Union.

[Electrochemical methods of control of iodine contents in drinks].

PubMed

Zakharova, E A; Slepchenko, G B; Kolpakova, E Iu

2001-01-01

The simple and express methods of determination of iodide ions (0.01-0.20 mg/decimeter3) in iodine-enriched drinks by potentiometry and inversion voltamperometry were developed. The studies on influencing a storage time hermetically packaged carbonated beverages, a storage time of the depressurized drinks, stuff of ware on the contents of iodine in drinks are held.

Effects of subduction and slab gaps on mantle flow beneath the Lesser Antilles based on observations of seismic anisotropy

NASA Astrophysics Data System (ADS)

Schlaphorst, David; Kendall, J.-Michael; Baptie, Brian; Latchman, Joan L.; Bouin, Marie-Paule

2016-04-01

Subduction is a key process in the formation of continental crust. However, the interaction of the mantle with the subducting slab is not fully understood and varies between subduction zones. The flow geometry and stress patterns influence seismic anisotropy; since anisotropic layers lead to variations in the speed of seismic waves as a function of the direction of wave propagation, mantle flow can be constrained by investigating the structure of these anisotropic layers. In this study we investigate seismic anisotropy in the eastern Greater and the Lesser Antilles along a subduction environment, including the crust and the upper mantle as regions of interest. We use a combination of teleseismic and local events recorded at three-component broadband seismic stations on every major island in the area to observe and distinguish between anisotropy in the crust, the mantle wedge and the sub-slab mantle. Local event delay times (0.21±0.12s) do not increase with depth, indicating a crustal origin and an isotropic mantle wedge. Teleseismic delay times are larger (1.34±0.47s), indicating sub-slab anisotropy. The results suggest trench-parallel mantle flow, with the exception of trench-perpendicular alignment in narrow regions east of Puerto Rico and south of Martinique, suggesting mantle flow through gaps in the slab. This agrees with the continuous northward mantle flow that is caused by the subducting slab proposed by previous studies of that region. We were able to identify a pattern previously unseen by other studies; on St. Lucia a trench-perpendicular trend also indicated by the stations around can be observed. This pattern can be explained by a mantle flow through a gap induced by the subduction of the boundary zone between the North and South American plates. This feature has been proposed for that area using tomographic modelling (van Benthem et al., 2013). It is based on previous results by Wadge & Shepherd (1984), who observed a vertical gap in the Wadati

Exploring the effect of anisotropy on body-wave tomography models: Rollback and subduction of the Alboran slab

NASA Astrophysics Data System (ADS)

Lee, H.; Bezada, M.

2017-12-01

Teleseismic P-wave tomography models often show low-velocity anomalies behind subducted slabs (i.e. opposite the direction of subduction). One such anomaly, behind the Alboran slab in the westernmost Mediterranean, requires partial melt in the mantle if taken at face-value. However, mantle anisotropy can cause low-velocity anomalies in tomographic models that assume isotropy. In fact, results from SKS splitting suggest rollback-induced anisotropy within the low-velocity region, and we investigate if this anisotropy can explain the sub-slab anomaly. We include anisotropy as an a priori constraint on the inversion and test different magnitudes, azimuths, and dips within the low-velocity region. We find that a range of anisotropic models can fit the travel time data as well as the isotropic models while significantly reducing or eliminating the low-velocity anomaly behind the slab. We conclude that this alternative interpretation (delays are caused by anisotropic structure) is as consistent with the travel time data as an isotropic low-velocity anomaly, and more consistent with SKS splitting observations and the known history of rollback. In addition, we find that models that include anisotropy with steeply dipping fast axes, meant to simulate the effect of downgoing entrained mantle, provide a poorer fit to the travel times than all the other models. This suggests that the slab may no longer be actively subducting.

Mantle flow through a tear in the Nazca slab inferred from shear wave splitting

NASA Astrophysics Data System (ADS)

Lynner, Colton; Anderson, Megan L.; Portner, Daniel E.; Beck, Susan L.; Gilbert, Hersh

2017-07-01

A tear in the subducting Nazca slab is located between the end of the Pampean flat slab and normally subducting oceanic lithosphere. Tomographic studies suggest mantle material flows through this opening. The best way to probe this hypothesis is through observations of seismic anisotropy, such as shear wave splitting. We examine patterns of shear wave splitting using data from two seismic deployments in Argentina that lay updip of the slab tear. We observe a simple pattern of plate-motion-parallel fast splitting directions, indicative of plate-motion-parallel mantle flow, beneath the majority of the stations. Our observed splitting contrasts previous observations to the north and south of the flat slab region. Since plate-motion-parallel splitting occurs only coincidentally with the slab tear, we propose mantle material flows through the opening resulting in Nazca plate-motion-parallel flow in both the subslab mantle and mantle wedge.

An Approach to the Flammability Testing of Aerospace Materials

NASA Technical Reports Server (NTRS)

Hirsch, David B.

2012-01-01

Presentation reviews: (1) Current approach to evaluation of spacecraft materials flammability (2) The need for and the approach to alternative routes (3) Examples of applications of the approach recommended a) Crew Module splash down b) Crew Module depressurization c) Applicability of NASA's flammability test data to other sample configurations d) Applicability of NASA's ground flammability test data to spacecraft environments

Numerical Modeling of Nanocellular Foams Using Classical Nucleation Theory and Influence Volume Approach

NASA Astrophysics Data System (ADS)

Khan, Irfan; Costeux, Stephane; Bunker, Shana; Moore, Jonathan; Kar, Kishore

2012-11-01

Nanocellular porous materials present unusual optical, dielectric, thermal and mechanical properties and are thus envisioned to find use in a variety of applications. Thermoplastic polymeric foams show considerable promise in achieving these properties. However, there are still considerable challenges in achieving nanocellular foams with densities as low as conventional foams. Lack of in-depth understanding of the effect of process parameters and physical properties on the foaming process is a major obstacle. A numerical model has been developed to simulate the simultaneous nucleation and bubble growth during depressurization of thermoplastic polymers saturated with supercritical blowing agents. The model is based on the popular ``Influence Volume Approach,'' which assumes a growing boundary layer with depleted blowing agent surrounds each bubble. Classical nucleation theory is used to predict the rate of nucleation of bubbles. By solving the mass balance, momentum balance and species conservation equations for each bubble, the model is capable of predicting average bubble size, bubble size distribution and bulk porosity. The model is modified to include mechanisms for Joule-Thompson cooling during depressurization and secondary foaming. Simulation results for polymer with and without nucleating agents will be discussed and compared with experimental data.

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

None, None

The most common method of measuring air leakage is to perform single (or solo) blower door pressurization and/or depressurization test. In detached housing, the single blower door test measures leakage to the outside. In attached housing, however, this "solo" test method measures both air leakage to the outside and air leakage between adjacent units through common surfaces. Although minimizing leakage to neighboring units is highly recommended to avoid indoor air quality issues between units, reduce pressure differentials between units, and control stack effect, the energy benefits of air sealing can be significantly overpredicted if the solo air leakage number ismore » used in the energy analysis. Guarded blower door testing is more appropriate for isolating and measuring leakage to the outside in attached housing. This method uses multiple blower doors to depressurize adjacent spaces to the same level as the unit being tested. Maintaining a neutral pressure across common walls, ceilings, and floors acts as a "guard" against air leakage between units. The resulting measured air leakage in the test unit is only air leakage to the outside. Although preferred for assessing energy impacts, the challenges of performing guarded testing can be daunting.« less

Evaluation of the Carefusion Alaris PC infusion pump for hyperbaric oxygen therapy conditions: Technical report.

PubMed

Smale, Andrew; Tsouras, Theo

2017-01-01

We present a standardized test methodology and results for our evaluation of the Carefusion Alaris PC infusion pump, comprising the model 8015 PC Unit and the model 8100 Large Volume Pump (LVP) module. The evaluation consisted of basic suitability testing, internal component inspection, surface temperature measurement of selected internal components, and critical performance testing (infusion rate accuracy and occlusion alarm pressure) during conditions of typical hyperbaric oxygen (HBO₂) treatment in our facility's class A multiplace chamber. We have found that the pumps pose no enhanced risk as an ignition source, and that the pumps operate within manufacturer's specifications for flow rate and occlusion alarms at all stages of HBO₂ treatments, up to 4.0 ATA and pressurization and depressurization rates up to 180 kPa/minute. The pumps do not require purging with air or nitrogen and can be used unmodified, subject to the following conditions: pumps are undamaged, clean, fully charged, and absent from alcohol cleaning residue; pumps are powered from the internal NiMH battery only; maximum pressure exposure 4.0 ATA; maximum pressurization and depressurization rate of 180 kPa/minute; LVP modules locked in place with retaining screws. Copyright© Undersea and Hyperbaric Medical Society.

Variable reluctance displacement transducer temperature compensated to 650$sup 0$F

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

None

In pressurized water reactor tests, compact instruments for accurate measurement of small displacements in a 650$sup 0$F environment are often required. In the case of blowdown tests such as the Loss of Fluid Test (LOFT) or Semiscale computer code development tests, not only is the initial environment water at 650$sup 0$F and 2200 psi but it undergoes a severe transient due to depressurization. Since the LOFT and Semiscale tests are run just for the purpose of obtaining data during the depressurization, instruments used to obtain the data must not give false outputs induced by the change in environment. A LOFTmore » rho v$sup 2$ probe and a Semiscale drag disk are described. Each utilizes a variable reluctance transducer (VRT) for indication of the drag-disk location and a torsion bar for drag-disk restoring force. The VRT, in addition to being thermally gain and null offset stable, is fabricated from materials known to be resistant to large nuclear radiation levels and has successfully passed a fast neutron radiation test of 2.7 x 10$sup 17$ nvt without failure. (auth)« less

Development and Application of a Three-Dimensional Finite Element Vapor Intrusion Model

PubMed Central

Pennell, Kelly G.; Bozkurt, Ozgur; Suuberg, Eric M.

2010-01-01

Details of a three-dimensional finite element model of soil vapor intrusion, including the overall modeling process and the stepwise approach, are provided. The model is a quantitative modeling tool that can help guide vapor intrusion characterization efforts. It solves the soil gas continuity equation coupled with the chemical transport equation, allowing for both advective and diffusive transport. Three-dimensional pressure, velocity, and chemical concentration fields are produced from the model. Results from simulations involving common site features, such as impervious surfaces, porous foundation sub-base material, and adjacent structures are summarized herein. The results suggest that site-specific features are important to consider when characterizing vapor intrusion risks. More importantly, the results suggest that soil gas or subslab gas samples taken without proper regard for particular site features may not be suitable for evaluating vapor intrusion risks; rather, careful attention needs to be given to the many factors that affect chemical transport into and around buildings. PMID:19418819

Irradiated ignition of solid materials in reduced pressure atmosphere with various oxygen concentrations for fire safety in space habitats

NASA Astrophysics Data System (ADS)

Nakamura, Y.; Aoki, A.

Effects of sub-atmospheric ambient pressure and oxygen content on irradiated ignition characteristics of solid combustibles were examined experimentally in order to elucidate the flammability and chance of fire in depressurized systems and give ideas for the fire safety and fire fighting strategies for such environments. Thin cellulosic paper was used as the solid combustible since cellulose is one of major organic compounds and flammables in the nature. Applied atmospheres consisted of inert gases (either CO 2 or N 2) and oxygen at various mixture ratios. Total ambient pressure ( P) was varied from 101 kPa (standard atmospheric pressure, P0) to 20 kPa. Ignition was initiated by external thermal radiation with CO 2 laser (10 W total; 21.3 W/cm 2 of the corresponding peak flux) onto the solid surface. Thermal degradation of the solid produced combustible gaseous products (e.g. CO, H 2, or other low weight of HCs) and these products mixed with ambient oxygen to form the combustible mixture over the solid. Heat transfer from the irradiated surface into the mixture accelerated the exothermic reaction in the gas phase and finally thermal runaway (ignition) was achieved. A digital video camera was used to analyze the ignition characteristics. Flammability maps in partial pressure of oxygen (ppO 2) and normalized ambient pressure ( P/ P0) plane were made to reveal the fire hazard in depressurized environments. Results showed that a wider flammable range was obtained in sub-atmospherics conditions. In middle pressure range (101-40 kPa), the required ppO 2 for ignition decreased almost linearly as the total pressure decreased, indicating that higher fire risk is expected. In lower pressure range (<40 kPa), the required partial pressure of oxygen increased dramatically, then ignition was eventually not achieved at pressures less than 20 kPa under the conditions studied here. The findings suggest that it might be difficult to satisfy safety in space agriculture since it has

Characterization via liquid chromatography coupled to diode array detector and tandem mass spectrometry of supercritical fluid antioxidant extracts of Spirulina platensis microalga.

PubMed

Mendiola, Jose A; Marín, Francisco R; Hernández, S Francisco; Arredondo, Bertha O; Señoráns, F Javier; Ibañez, Elena; Reglero, Guillermo

2005-06-01

Spirulina platensis microalga has been extracted on a pilot scale plant using supercritical fluid extraction (SFE) under various extraction conditions. The extraction yield and the antioxidant activity of the extracts were evaluated in order to select those extracts with both the highest antioxidant capacity and a good extraction yield. These extracts were characterized using LC coupled to diode array detection (DAD) and LC coupled to mass spectrometry (MS) with two different interfaces, atmospheric pressure chemical ionization (APCI) and electrospray (ESI) which allowed us to perform tandem MS by using an ion trap analyzer. The best extraction conditions were as follows: CO2 with 10% of modifier (ethanol) as extraction solvent, 55 degrees C (extraction temperature) and 220 bar (extraction pressure). Fractionation was achieved by cascade depressurization providing two extracts with different activity and chemical composition. Several compounds have been identified in the extracts, corresponding to different carotenoids previously identified in Spirulina platensis microalga along with chlorophyll a and some degradation products. Also, the structure of some phenolic compounds could be tentatively identified. The antioxidant activity of the extracts could be attributed to some of the above mentioned compounds.

The Dynamics of Solid Propellant Combustion.

DTIC Science & Technology

1980-12-31

review the theory and summarize most of the nume- rical and experimental findings by our research group . The complete literature so far published by this...deradiation reported by the Princeton group (Refs. 58-59). Ciepluch (Refs.20-22) conducted one of the first systematic experimental studies of depressurization...is the reaction order of the overall, one-step, irreversible kinetics controlling the gas phase heat release. Taking into account the quasi -steady

DTO 1118 - Damaged Spektr solar array

NASA Image and Video Library

1998-03-04

S89-E-5190 (25 Jan 1998) --- This Electronic Still Camera (ESC) image shows the Russian Mir Space Station's damaged solar array panel. The solar array panel was damaged as a result of an impact with an unmanned Progress re-supply ship which collided with the Mir on June 25, 1997, causing the Spektr Module to depressurize. This ESC view was taken on January 25, 1998 at 16:56:30 GMT.

Building America Case Study: Simplified Air Distribution, Desuperheaters, and Sub-Slab Geothermal Heat Exchangers, Pittsburgh, Pennsylvania

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

This report presents a cold-climate project that examines an alternative approach to ground source heat pump (GSHP) ground loop design. The innovative ground loop design is an attempt to reduce the installed cost of the ground loop heat exchange portion of the system by containing the entire ground loop within the excavated location beneath the basement slab.

INDOOR AIR SAMPLING, SUB-SLAB VAPOR SAMPLING, AND SLAB AIR-PERMEABILITY TESTING AT THE RAYMARK SITE

EPA Science Inventory

By 2005, U.S. EPA and its state, tribal and local partners must assess, reduce, and/or control the risk to human health and the environment at more than 374,000 contaminated Superfund, RCRA, underground storage tank (UST), brownfield and oil sites. U.S. EPA is currently developi...

INDOOR AIR SAMPLING, SUB-SLAB VAPOR SAMPLING, AND SLAB AIR PERMEABILITY TESTING AT THE RAYMARK SITE

EPA Science Inventory

By 2005, U.S. EPA and its state, tribal and local partners must assess, reduce, and/or control the risk to human health and the environment at more than 374,000 contaminated Superfund, RCRA, underground storage tank (UST), brownfield and oil sites. U.S. EPA is currently developi...

Comparison of V-4 and V-5 Exercise/Oxygen Prebreathe Protocols to Support Extravehicular Activity in Microgravity

NASA Technical Reports Server (NTRS)

Pollock, N. W.; Natoli, M. J.; Vann, R. D.; Gernhardt, M. L.; Conkin, Johnny

2007-01-01

The Prebreathe Reduction Program (PRP) used exercise during oxygen prebreathe to reduce necessary prebreathe time prior to depressurizing to work in a 4.3 psi suit during extravehicular activity (EVA). Initial testing produced a two-hour protocol incorporating ergometry exercise and a 30 min cycle of depress/repress to 10.2 psi where subjects breathed 26.5% oxygen/balance nitrogen (Phase II - 10 min at 75% peak oxygen consumption [VO2 peak] followed by 40 min intermittent light exercise [ILE] [approx. 5.8 mL-per kilogram- per minute], then 50 min of rest). The Phase II protocol (0/45 DCS) was approved for operations and has been used on 40 EVAs, providing significant time savings compared to the standard 4 h resting oxygen prebreathe. The Phase V effort focused on performing all light in-suit exercise. Two oxygen prebreathe protocols were tested sequentially: V-4) 160 min prebreathe with 150 min of continuous ILE. The entire protocol was completed at 14.7 psi. All exercise involved upper body effort. Exercise continued until decompression. V-5) 160 min prebreathe with 140 min of ILE - first 40 min at 14.7 psi, then 30 min at 10.2 psi (breathing 26.5% oxygen) after a 20 min depress, simulating a suit donning period. Subjects were then repressed to 14.7 psi and performed another 50 min of lower body ILE, followed by 50 min rest before decompression. The V-4 protocol was rejected with 3 DCS/6 person-exposures. Initial V-5 testing has produced 0 DCS/11 person-exposures (ongoing trials). The difference in DCS rate was significant (Fisher Exact p=0.029). The observations of DCS were significantly lower in early V-5 trials than in V-4 trials. Additional studies are required to evaluate the relative contribution of the variables in exercise distribution, the 10.2 psi depress/repress component, pre-decompression rest, or possible variation in total oxygen consumption.

Editors' Choice—Field Trials Testing of Mixed Potential Electrochemical Hydrogen Safety Sensors at Commercial California Hydrogen Filling Stations

DOE PAGES

Brosha, Eric Lanich; Romero, Christopher Jesse; Poppe, Daniel; ...

2017-10-27

Hydrogen safety sensors must meet specific performance requirements, mandated by the U.S. Department of Energy, for hydrogen fueling station monitoring. Here, we describe the long-term performance of two zirconia-based mixed potential electrochemical hydrogen gas sensors, developed specifically with a high sensitivity to hydrogen, low cross-sensitivity, and fast response time. Over a two-year period, sensors with tin-doped indium oxide and strontium doped lanthanum chromite electrodes were deployed at two stations in four field trials tests conducted in Los Angeles. The sensors documented the existence of hydrogen plumes ranging in concentration from 100 to as high as 2700 ppm in the areamore » surrounding the dispenser, consistent with depressurization from 700 bar following vehicle refueling. As expected, the hydrogen concentration reported by the mixed potential sensors was influenced by wind direction. Baseline stability testing at a Chino, CA station showed no measureable baseline drift throughout 206 days of uninterrupted data acquisition. The high baseline stability, excellent correlation with logged fueling/depressurization events, and absence of false alarms suggest that the zirconia-based mixed potential sensor platform is a good candidate for protecting hydrogen infrastructure where frequent calibrations or sensor replacement to reduce the false alarm frequency have been shown to be cost prohibitive.« less

Editors' Choice—Field Trials Testing of Mixed Potential Electrochemical Hydrogen Safety Sensors at Commercial California Hydrogen Filling Stations

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

Brosha, Eric Lanich; Romero, Christopher Jesse; Poppe, Daniel

Hydrogen safety sensors must meet specific performance requirements, mandated by the U.S. Department of Energy, for hydrogen fueling station monitoring. Here, we describe the long-term performance of two zirconia-based mixed potential electrochemical hydrogen gas sensors, developed specifically with a high sensitivity to hydrogen, low cross-sensitivity, and fast response time. Over a two-year period, sensors with tin-doped indium oxide and strontium doped lanthanum chromite electrodes were deployed at two stations in four field trials tests conducted in Los Angeles. The sensors documented the existence of hydrogen plumes ranging in concentration from 100 to as high as 2700 ppm in the areamore » surrounding the dispenser, consistent with depressurization from 700 bar following vehicle refueling. As expected, the hydrogen concentration reported by the mixed potential sensors was influenced by wind direction. Baseline stability testing at a Chino, CA station showed no measureable baseline drift throughout 206 days of uninterrupted data acquisition. The high baseline stability, excellent correlation with logged fueling/depressurization events, and absence of false alarms suggest that the zirconia-based mixed potential sensor platform is a good candidate for protecting hydrogen infrastructure where frequent calibrations or sensor replacement to reduce the false alarm frequency have been shown to be cost prohibitive.« less

Culturable prokaryotic diversity of deep, gas hydrate sediments: first use of a continuous high-pressure, anaerobic, enrichment and isolation system for subseafloor sediments (DeepIsoBUG)

PubMed Central

Parkes, R John; Sellek, Gerard; Webster, Gordon; Martin, Derek; Anders, Erik; Weightman, Andrew J; Sass, Henrik

2009-01-01

Deep subseafloor sediments may contain depressurization-sensitive, anaerobic, piezophilic prokaryotes. To test this we developed the DeepIsoBUG system, which when coupled with the HYACINTH pressure-retaining drilling and core storage system and the PRESS core cutting and processing system, enables deep sediments to be handled without depressurization (up to 25 MPa) and anaerobic prokaryotic enrichments and isolation to be conducted up to 100 MPa. Here, we describe the system and its first use with subsurface gas hydrate sediments from the Indian Continental Shelf, Cascadia Margin and Gulf of Mexico. Generally, highest cell concentrations in enrichments occurred close to in situ pressures (14 MPa) in a variety of media, although growth continued up to at least 80 MPa. Predominant sequences in enrichments were Carnobacterium, Clostridium, Marinilactibacillus and Pseudomonas, plus Acetobacterium and Bacteroidetes in Indian samples, largely independent of media and pressures. Related 16S rRNA gene sequences for all of these Bacteria have been detected in deep, subsurface environments, although isolated strains were piezotolerant, being able to grow at atmospheric pressure. Only the Clostridium and Acetobacterium were obligate anaerobes. No Archaea were enriched. It may be that these sediment samples were not deep enough (total depth 1126–1527 m) to obtain obligate piezophiles. PMID:19694787

Space suit glove design with advanced metacarpal phalangeal joints and robotic hand evaluation.

PubMed

Southern, Theodore; Roberts, Dustyn P; Moiseev, Nikolay; Ross, Amy; Kim, Joo H

2013-06-01

One area of space suits that is ripe for innovation is the glove. Existing models allow for some fine motor control, but the power grip--the act of grasping a bar--is cumbersome due to high torque requirements at the knuckle or metacarpal phalangeal joint (MCP). This area in particular is also a major source of complaints of pain and injury as reported by astronauts. This paper explores a novel fabrication and patterning technique that allows for more freedom of movement and less pain at this crucial joint in the manned space suit glove. The improvements are evaluated through unmanned testing, manned testing while depressurized in a vacuum glove box, and pressurized testing with a robotic hand. MCP joint flex score improved from 6 to 6.75 (out of 10) in the final glove relative to the baseline glove, and torque required for flexion decreased an average of 17% across all fingers. Qualitative assessments during unpressurized and depressurized manned testing also indicated the final glove was more comfortable than the baseline glove. The quantitative results from both human subject questionnaires and robotic torque evaluation suggest that the final iteration of the glove design enables flexion at the MCP joint with less torque and more comfort than the baseline glove.

An Assessment of Helium Evolution from Helium-Saturated Propellant Depressurization in Space

NASA Technical Reports Server (NTRS)

Nguyen, Bich N.; Best, Frederick; Wong, Tony; Kurwitz, Cable; McConnaughey, H. (Technical Monitor)

2001-01-01

Helium evolution from the transfer of helium-saturated propellant in space is quantified to assess its impacts from creating two-phase gas/liquid flow from the supply tank, gas injection into the receiving tank, and liquid discharge from the receiving tank. Propellant transfer takes place between two similar tanks whose maximum storage capacity is approximately 2.55 cubic meters each. The maximum on-orbit propellants transfer capability is 9000 lbm (fuel and oxidizer). The transfer line is approximately 1.27 cm in diameter and 6096 cm in length and comprised of the fluid interconnect system (FICS), the orbiter propellant transfer system (OPTS), and the International Space Station (ISS) propulsion module (ISSPM). The propellant transfer rate begins at approximately 11 liter per minute (lpm) and subsequently drops to approximately 0.5 lpm. The tank nominal operating pressure is approximately 1827 kPa (absolute). The line pressure drops for Monomethy1hydrazine (MMH) and Nitrogen tetroxide (NTO) at 11.3 lpm are approximately 202 kPa and 302 kPa, respectively. The pressure-drop results are based on a single-phase flow. The receiving tank is required to vent from approximately 1827 kPa to a lower pressure to affect propellant transfer. These pressure-drop scenarios cause the helium-saturated propellants to release excess helium. For tank ullage venting, the maximum volumes of helium evolved at tank pressure are approximately 0.5 ft3 for MMH and 2 ft3 for NTO. In microgravity environment, due to lack of body force, the helium evolution from a liquid body acts to propel it, which influences its fluid dynamics. For propellant transfer, the volume fractions of helium evolved at line pressure are 0.1% by volume for MMH and 0.6 % by volume for NTO at 11.3 lpm. The void fraction of helium evolved varies as an approximate second order power function of flow rate.

Fluidic self-actuating control assembly

DOEpatents

Grantz, Alan L.

1979-01-01

A fluidic self-actuating control assembly for use in a reactor wherein no external control inputs are required to actuate (scram) the system. The assembly is constructed to scram upon sensing either a sudden depressurization of reactor inlet flow or a sudden increase in core neutron flux. A fluidic control system senses abnormal flow or neutron flux transients and actuates the system, whereupon assembly coolant flow reverses, forcing absorber balls into the reactor core region.

A case of death of the driver due to environmental asphyxia by liquid nitrogen leakage in the cabin of the car during a road accident

PubMed

Raczkowska, Zuzanna; Samojłowicz, Dorota

2013-01-01

Nitrogen causes environmental asphyxia by displacing oxygen in the air leading to death. The study presents a case of a death of a driver death who was transporting flasks with liquid nitrogen that depressurized during an accident. The mechanism and cause of death were determined based on the result of the autopsy and histopathologic examination. The authors emphasize the relevance of accident scene inspection during establishing the cause of death in similar cases.

Using SA508/533 for the HTGR Vessel Material

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

Larry Demick

2012-06-01

This paper examines the influence of High Temperature Gas-cooled Reactor (HTGR) module power rating and normal operating temperatures on the use of SA508/533 material for the HTGR vessel system with emphasis on the calculated times at elevated temperatures approaching or exceeding ASME Code Service Limits (Levels B&C) to which the reactor pressure vessel could be exposed during postulated pressurized and depressurized conduction cooldown events over its design lifetime.

Aerospace applications of SINDA/FLUINT at the Johnson Space Center

NASA Technical Reports Server (NTRS)

Ewert, Michael K.; Bellmore, Phillip E.; Andish, Kambiz K.; Keller, John R.

1992-01-01

SINDA/FLUINT has been found to be a versatile code for modeling aerospace systems involving single or two-phase fluid flow and all modes of heat transfer. Several applications of SINDA/FLUINT are described in this paper. SINDA/FLUINT is being used extensively to model the single phase water loops and the two-phase ammonia loops of the Space Station Freedom active thermal control system (ATCS). These models range from large integrated system models with multiple submodels to very detailed subsystem models. An integrated Space Station ATCS model has been created with ten submodels representing five water loops, three ammonia loops, a Freon loop and a thermal submodel representing the air loop. The model, which has approximately 800 FLUINT lumps and 300 thermal nodes, is used to determine the interaction between the multiple fluid loops which comprise the Space Station ATCS. Several detailed models of the flow-through radiator subsystem of the Space Station ATCS have been developed. One model, which has approximately 70 FLUINT lumps and 340 thermal nodes, provides a representation of the ATCS low temperature radiator array with two fluid loops connected only by conduction through the radiator face sheet. The detailed models are used to determine parameters such as radiator fluid return temperature, fin efficiency, flow distribution and total heat rejection for the baseline design as well as proposed alternate designs. SINDA/FLUINT has also been used as a design tool for several systems using pressurized gasses. One model examined the pressurization and depressurization of the Space Station airlock under a variety of operating conditions including convection with the side walls and internal cooling. Another model predicted the performance of a new generation of manned maneuvering units. This model included high pressure gas depressurization, internal heat transfer and supersonic thruster equations. The results of both models were used to size components, such as the

Numerical simulation of gas hydrate exploitation from subsea reservoirs in the Black Sea

NASA Astrophysics Data System (ADS)

Janicki, Georg; Schlüter, Stefan; Hennig, Torsten; Deerberg, Görge

2017-04-01

Natural gas (methane) is the most environmental friendly source of fossil energy. When coal is replace by natural gas in power production the emission of carbon dioxide is reduced by 50 %. The vast amount of methane assumed in gas hydrate deposits can help to overcome a shortage of fossil energy resources in the future. To increase their potential for energy applications new technological approaches are being discussed and developed worldwide. Besides technical challenges that have to be overcome climate and safety issues have to be considered before a commercial exploitation of such unconventional reservoirs. The potential of producing natural gas from subsea gas hydrate deposits by various means (e. g. depressurization and/or carbon dioxide injection) is numerically studied in the frame of the German research project »SUGAR - Submarine Gas Hydrate Reservoirs«. In order to simulate the exploitation of hydrate-bearing sediments in the subsea, an in-house simulation model HyReS which is implemented in the general-purpose software COMSOL Multiphysics is used. This tool turned out to be especially suited for the flexible implementation of non-standard correlations concerning heat transfer, fluid flow, hydrate kinetics, and other relevant model data. Partially based on the simulation results, the development of a technical concept and its evaluation are the subject of ongoing investigations, whereby geological and ecological criteria are to be considered. The results illustrate the processes and effects occurring during the gas production from a subsea gas hydrate deposit by depressurization. The simulation results from a case study for a deposit located in the Black Sea reveal that the production of natural gas by simple depressurization is possible but with quite low rates. It can be shown that the hydrate decomposition and thus the gas production strongly depend on the geophysical properties of the reservoir, the mass and heat transport within the reservoir, and

Core-power and decay-time limits for disabled automatic-actuation of LOFT ECCS

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

Hanson, G.H.

1978-06-05

The Emergency Core Cooling System (ECCS) for the LOFT reactor may need to be disabled for modifications or repairs of hardware or instrumentation or for component testing during periods when the reactor system is hot and pressurized, or it may be desirable to enable the ECCS to be disabled without the necessity of cooling down and depressurizing the reactor. LTR 113-47 has shown that the LOFT ECCS can be safely bypassed or disabled when the total core power does not exceed 25 kW. A modified policy involves disabling the automatic actuation of the LOFT ECCS, but still retaining the manualmore » activation capability. Disabling of the automatic actuation can be safely utilized, without subjecting the fuel cladding to unacceptable temperatures, when the LOFT power decays to 70 kW; this power level permits a maximum delay of 20 minutes following a LOCA for the manual actuation of ECCS.« less

Spatial and temporal seismic velocity changes on Kyushu Island during the 2016 Kumamoto earthquake

PubMed Central

Nimiya, Hiro; Ikeda, Tatsunori; Tsuji, Takeshi

2017-01-01

Monitoring of earthquake faults and volcanoes contributes to our understanding of their dynamic mechanisms and to our ability to predict future earthquakes and volcanic activity. We report here on spatial and temporal variations of seismic velocity around the seismogenic fault of the 2016 Kumamoto earthquake [moment magnitude (Mw) 7.0] based on ambient seismic noise. Seismic velocity near the rupture faults and Aso volcano decreased during the earthquake. The velocity reduction near the faults may have been due to formation damage, a change in stress state, and an increase in pore pressure. Further, we mapped the post-earthquake fault-healing process. The largest seismic velocity reduction observed at Aso volcano during the earthquake was likely caused by pressurized volcanic fluids, and the large increase in seismic velocity at the volcano’s magma body observed ~3 months after the earthquake may have been a response to depressurization caused by the eruption. This study demonstrates the usefulness of continuous monitoring of faults and volcanoes. PMID:29202026

Venous Gas Emboli and Ambulation at 4.3 PSIA (Preliminary)

NASA Technical Reports Server (NTRS)

Conkin, J.; Pollock, N. W.; Natoli, M. J.; Martina, S. D.; Wessel, J. H., III; Gernhardt, M. L.

2016-01-01

Ambulation imparts compressive and decompressive forces into the lower body, potentially creating quasi-stable micronuclei that influence the outcome of hypobaric depressurizations. Hypotheses: ambulation before the conclusion of a denitrogenation (prebreathe) protocol at 14.7 pounds per square inch absolute is not sufficient to increase the incidence of venous gas emboli (VGE) at 4.3 pounds per square inch absolute but is sufficient if performed after tissues become supersaturated with nitrogen at 4.3 pounds per square inch absolute.

Osmotically-assisted desalination method and system

DOEpatents

Achilli, Andrea; Childress, Amy E.; Cath, Tzahi Y.

2014-08-12

Systems and methods for osmotically assisted desalination include using a pressurized concentrate from a pressure desalination process to pressurize a feed to the desalination process. The depressurized concentrate thereby produced is used as a draw solution for a pressure-retarded osmosis process. The pressure-retarded osmosis unit produces a pressurized draw solution stream that is used to pressurize another feed to the desalination process. In one example, the feed to the pressure-retarded osmosis process is impaired water.

Survey views of the Mir space station

NASA Image and Video Library

1997-10-20

STS086-720-007 (25 Sept.-6 Oct. 1997) --- A 70mm view of Russia’s Mir Space Station’s Spektr Module shows the backside of a solar array panel and damage incurred by the impact of a Russian unmanned Progress re-supply ship which collided with the space station on June 25, 1997, causing Spektr to depressurize. A radiator, which also was struck by the Progress, is out of view from this angle. Photo credit: NASA

South-American plate advance and forced Andean trench retreat as drivers for transient flat subduction episodes.

PubMed

Schepers, Gerben; van Hinsbergen, Douwe J J; Spakman, Wim; Kosters, Martha E; Boschman, Lydian M; McQuarrie, Nadine

2017-05-16

At two trench segments below the Andes, the Nazca Plate is subducting sub-horizontally over ∼200-300 km, thought to result from a combination of buoyant oceanic-plateau subduction and hydrodynamic mantle-wedge suction. Whether the actual conditions for both processes to work in concert existed is uncertain. Here we infer from a tectonic reconstruction of the Andes constructed in a mantle reference frame that the Nazca slab has retreated at ∼2 cm per year since ∼50 Ma. In the flat slab portions, no rollback has occurred since their formation at ∼12 Ma, generating 'horse-shoe' slab geometries. We propose that, in concert with other drivers, an overpressured sub-slab mantle supporting the weight of the slab in an advancing upper plate-motion setting can locally impede rollback and maintain flat slabs until slab tearing releases the overpressure. Tear subduction re-establishes a continuous slab and allows the process to recur, providing a mechanism for the transient character of flat slabs.

Experimental and analytical study of cryogenic propellant boiloff to develop and verify alternate pressurization concepts for Space Shuttle external tank using a scaled down tank

NASA Technical Reports Server (NTRS)

Akyuzlu, K. M.; Jones, S.; Meredith, T.

1993-01-01

Self pressurization by propellant boiloff is experimentally studied as an alternate pressurization concept for the Space Shuttle external tank (ET). The experimental setup used in the study is an open flow system which is composed of a variable area test tank and a recovery tank. The vacuum jacketed test tank is geometrically similar to the external LOx tank for the Space Shuttle. It is equipped with instrumentation to measure the temperature and pressure histories within the liquid and vapor, and viewports to accommodate visual observations and Laser-Doppler Anemometry measurements of fluid velocities. A set of experiments were conducted using liquid Nitrogen to determine the temperature stratification in the liquid and vapor, and pressure histories of the vapor during sudden and continuous depressurization for various different boundary and initial conditions. The study also includes the development and calibration of a computer model to simulate the experiments. This model is a one-dimensional, multi-node type which assumes the liquid and the vapor to be under non-equilibrium conditions during the depressurization. It has been tested for a limited number of cases. The preliminary results indicate that the accuracy of the simulations is determined by the accuracy of the heat transfer coefficients for the vapor and the liquid at the interface which are taken to be the calibration parameters in the present model.

Applying large datasets to developing a better understanding of air leakage measurement in homes

DOE PAGES

Walker, I. S.; Sherman, M. H.; Joh, J.; ...

2013-03-01

Air tightness is an important property of building envelopes. It is a key factor in determining infiltration and related wall-performance properties such as indoor air quality, maintainability and moisture balance. Air leakage in U.S. houses consumes roughly 1/3 of the HVAC energy but provides most of the ventilation used to control IAQ. There are several methods for measuring air tightness that may result in different values and sometimes quite different uncertainties. The two main approaches trade off bias and precision errors and thus result indifferent outcomes for accuracy and repeatability. To interpret results from the two approaches, various questions needmore » to be addressed, such as the need to measure the flow exponent, the need to make both pressurization and depressurization measurements and the role of wind in determining the accuracy and precision of the results. This article uses two large datasets of blower door measurements to reach the following conclusions. For most tests the pressure exponent should be measured but for wind speeds greater than 6 m/s a fixed pressure exponent reduces experimental error. The variability in reported pressure exponents is mostly due to changes in envelope leakage characteristics. Finally, it is preferable to test in both pressurization and depressurization modes due to significant differences between the results in these two modes.« less

Rapid Evaporation of microbubbles

NASA Astrophysics Data System (ADS)

Gautam, Jitendra; Esmaeeli, Asghar

2008-11-01

When a liquid is heated to a temperature far above its boiling point, it evaporates abruptly. Boiling of liquid at high temperatures can be explosive and destructive, and poses a potential hazard for a host of industrial processes. Explosive boiling may occur if a cold and volatile liquid is brought into contact with a hot and non-volatile liquid, or if a liquid is superheated or depressurized rapidly. Such possibilities are realized, for example, in the depressurization of low boiling point liquefied natural gas (LNG) in the pipelines or storage tanks as a result of a leak. While boiling of highly heated liquids can be destructive at macroscale, the (nearly) instantaneous pace of the process and the release of large amount of kinetic energy make the phenomena extremely attractive at microscale where it is possible to utilize the released energy to derive micromechanical systems. For instance, there is currently a growing interest in micro-explosion of liquid for generation of micro bubbles for actuation purposes. The aim of the current study is to gain a fundamental understanding of the subject using direct numerical simulations. In particular, we seek to investigate the boundary between stable and unstable nucleus growth in terms of the degree of liquid superheat and to compare the dynamics of unstable and stable growth.

Summary of typical parameters that affect sound transmission through general aviation aircraft structures

NASA Technical Reports Server (NTRS)

Grosveld, F.; Navaneethan, R.; Roskam, J.

1981-01-01

This paper presents results of a systematic experimental investigation of parameters which affect sound transmission through general aviation structures. Parameters studied include angle of sound incidence, panel curvature, panel stresses, and edge conditions for bare panels; pane thickness, spacing, inclination of window panes, and depressurization for dual pane windows; densities of hard foam and sound absorption materials, air gaps, and trim panel thickness for multilayered panels. Based on the study, some promising methods for reducing interior noise in general aviation airplanes are discussed.

Final work plan : supplemental upward vapor intrusion investigation at the former CCC/USDA grain storage facility in Hanover, Kansas.

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

LaFreniere, L. M.; Environmental Science Division

and chloroform into four homes located on or adjacent to the former CCC/USDA facility. The technical objective will be accomplished by collecting sub-slab vapor samples. The preliminary data collected during the July 2007 investigation did not fully address the source of or migration pathway for the carbon tetrachloride detected in the four homes. The scope of work proposed here will generate additional data needed to help evaluate whether the source of the detected carbon tetrachloride is vapor intrusion attributable to activities of the CCC/USDA. The additional vapor sampling at Hanover will be performed, on behalf of the CCC/USDA, by the Environmental Science Division of Argonne National Laboratory and H&P Mobile Geochemistry of San Diego (http://www.handpmg.com). Argonne is a nonprofit, multidisciplinary research center operated by UChicago Argonne, LLC, for the U.S. Department of Energy (DOE). The CCC/USDA has entered into an interagency agreement with DOE, under which Argonne provides technical assistance to the CCC/USDA with environmental site characterization and remediation at its former grain storage facilities. The professional staff members of H&P Mobile Geochemistry are nationally leading experts in soil gas sampling and vapor intrusion investigations.« less

Tomographic imaging of the effects of Peruvian flat slab subduction on the Nazca slab and surrounding mantle under central and southern Peru

NASA Astrophysics Data System (ADS)

Scire, A. C.; Zandt, G.; Beck, S. L.; Bishop, B.; Biryol, C. B.; Wagner, L. S.; Long, M. D.; Minaya, E.; Tavera, H.

2014-12-01

directly below projection of the Nazca Ridge but descends to ~300 km depth in the mantle. This sub-slab slow anomaly may correlate with vertical mantle flow induced by movement of material through the inferred tear in the slab north of the Nazca Ridge or alternately may represent a long-lived feature of the sub-slab mantle possibly associated with the development of the Nazca Ridge at the Easter Island hot spot.

Continuous Removal of Coal-Gasification Residue

NASA Technical Reports Server (NTRS)

Collins, Earl R., Jr.; Suitor, J.; Dubis, D.

1986-01-01

Continuous-flow hopper processes solid residue from coal gasification, converting it from ashes, cinders, and clinkers to particles size of sand granules. Unit does not require repeated depressurization of lockhopper to admit and release materials. Therefore consumes less energy. Because unit has no airlock valves opened and closed repeatedly on hot, abrasive particles, subjected to lesser wear. Coal-gasification residue flows slowly through pressure-letdown device. Material enters and leaves continuously. Cleanout door on each pressure-letdown chamber allows access for maintenance and emergencies.

Process for operating equilibrium controlled reactions

DOEpatents

Nataraj, Shankar; Carvill, Brian Thomas; Hufton, Jeffrey Raymond; Mayorga, Steven Gerard; Gaffney, Thomas Richard; Brzozowski, Jeffrey Richard

2001-01-01

A cyclic process for operating an equilibrium controlled reaction in a plurality of reactors containing an admixture of an adsorbent and a reaction catalyst suitable for performing the desired reaction which is operated in a predetermined timed sequence wherein the heating and cooling requirements in a moving reaction mass transfer zone within each reactor are provided by indirect heat exchange with a fluid capable of phase change at temperatures maintained in each reactor during sorpreaction, depressurization, purging and pressurization steps during each process cycle.

Guest Molecule Exchange Kinetics for the 2012 Ignik Sikumi Gas Hydrate Field Trial

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

White, Mark D.; Lee, Won Suk

A commercially viable technology for producing methane from natural gas hydrate reservoirs remains elusive. Short-term depressurization field tests have demonstrated the potential for producing natural gas via dissociation of the clathrate structure, but the long-term performance of the depressurization technology ultimately requires a heat source to sustain the dissociation. A decade of laboratory experiments and theoretical studies have demonstrated the exchange of pure CO2 and N2-CO2 mixtures with CH4 in sI gas hydrates, yielding critical information about molecular mechanisms, recoveries, and exchange kinetics. Findings indicated the potential for producing natural gas with little to no production of water and rapidmore » exchange kinetics, generating sufficient interest in the guest-molecule exchange technology for a field test. In 2012 the U.S. DOE/NETL, ConocoPhillips Company, and Japan Oil, Gas and Metals National Corporation jointly sponsored the first field trial of injecting a mixture of N2-CO2 into a CH4-hydrate bearing formation beneath the permafrost on the Alaska North Slope. Known as the Ignik Sikumi #1 Gas Hydrate Field Trial, this experiment involved three stages: 1) the injection of a N2-CO2 mixture into a targeted hydrate-bearing layer, 2) a 4-day pressurized soaking period, and 3) a sustained depressurization and fluid production period. Data collected during the three stages of the field trial were made available after an extensive quality check. These data included continuous temperature and pressure logs, injected and recovered fluid compositions and volumes. The Ignik Sikumi #1 data set is extensive, but contains no direct evidence of the guest-molecule exchange process. This investigation is directed at using numerical simulation to provide an interpretation of the collected data. A numerical simulator, STOMP-HYDT-KE, was recently completed that solves conservation equations for energy, water, mobile fluid guest molecules, and hydrate

Introduction of the 2007-2008 JOGMEC/NRCan/Aurora Mallik Gas Hydrate Production Research Program, NWT, Canada

NASA Astrophysics Data System (ADS)

Yamamoto, K.; Dallimore, S. R.; Numasawa, M.; Yasuda, M.; Fujii, T.; Fujii, K.; Wright, J.; Nixon, F.

2007-12-01

Japan Oil, Gas and Metals National Corporation (JOGMEC) and Natural Resource Canada (NRCan) have embarked on a new research program to study the production potential of gas hydrates. The program is being carried out at the Mallik gas hydrate field in the Mackenzie Delta, a location where two previous scientific investigations have been carried in 1998 and 2002. In the 2002 program that was undertaken by seven partners from five countries, 468m3 of gas flow was measured during 124 hours of thermal stimulation using hot warm fluid. Small-scale pressure drawdown tests were also carried out using Schlumberger's Modular Dynamics Tester (MDT) wireline tool, gas flow was observed and the inferred formation permeabilities suggested the possible effectiveness of the simple depressurization method. While the testing undertaken in 2002 can be cited as the first well constrained gas production from a gas hydrate deposit, the results fell short of that required to fully calibrate reservoir simulation models or indeed establish the technical viability of long term production from gas hydrates. The objectives of the current JOGMEC/NRCan/Aurora Mallik production research program are to undertake longer term production testing to further constrain the scientific unknowns and to demonstrate the technical feasibility of sustained gas hydrate production using the depressurization method. A key priority is to accurately measure water and gas production using state-of-art production technologies. The primary production test well was established during the 2007 field season with the re-entry and deepening of JAPEX/JNOC/GSC Mallik 2L-38 well, originally drilled in 1998. Production testing was carried out in April of 2007 under a relatively low drawdown pressure condition. Flow of methane gas was measured from a 12m perforated interval of gas-hydrate-saturated sands from 1093 to 1105m. The results establish the potential of the depressurization method and provide a basis for future

Posttest analysis of MIST Test 320201 using TRAC-PF1/MOD1

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

Siebe, D.A.; Steiner, J.L.; Boyack, B.E.

A posttest calculation and analysis of Multi-Loop Integral System Test 320201, a small-break loss-of-coolant accident (SBLOCA) test with a scaled 50-cm{sup 2} cold-leg pump discharge leak, has been completed and is reported herein. It was one in a series of tests, with leak size varied parametrically. Scaled leak sizes included 5, 10, (the nominal, Test 3109AA), and 50 cm{sub 2}. The test exhibited the major post-SBLOCA phenomena, as expected, including depressurization to saturation, interruption of loop flow, boiler-condenser mode cooling, refill, and postrefill cooldown. Full high-pressure injection and auxiliary feedwater were available, reactor coolant pumps were not available, and reactor-vesselmore » vent valves and guard heaters were automatically controlled. Constant level control in the steam-generator (SG) secondaries was used after SG-secondary refill; and symmetric SG pressure control was also used. The sequence of events seen in this test was similar to the sequence of events for much of the nominal test except that events occurred in a shorter time frame as the system inventory was reduced and the system depressurized at a faster rate. The calculation was performed using TRAC-PFL/MOD 1. Agreement between test data and the calculation was generally reasonable. All major trends and phenomena were correctly predicted. We believe that the correct conclusions about trends and phenomena will be reached if the code is used in similar applications.« less

Posttest analysis of MIST Test 320201 using TRAC-PF1/MOD1

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

Siebe, D.A.; Steiner, J.L.; Boyack, B.E.

A posttest calculation and analysis of Multi-Loop Integral System Test 320201, a small-break loss-of-coolant accident (SBLOCA) test with a scaled 50-cm[sup 2] cold-leg pump discharge leak, has been completed and is reported herein. It was one in a series of tests, with leak size varied parametrically. Scaled leak sizes included 5, 10, (the nominal, Test 3109AA), and 50 cm[sub 2]. The test exhibited the major post-SBLOCA phenomena, as expected, including depressurization to saturation, interruption of loop flow, boiler-condenser mode cooling, refill, and postrefill cooldown. Full high-pressure injection and auxiliary feedwater were available, reactor coolant pumps were not available, and reactor-vesselmore » vent valves and guard heaters were automatically controlled. Constant level control in the steam-generator (SG) secondaries was used after SG-secondary refill; and symmetric SG pressure control was also used. The sequence of events seen in this test was similar to the sequence of events for much of the nominal test except that events occurred in a shorter time frame as the system inventory was reduced and the system depressurized at a faster rate. The calculation was performed using TRAC-PFL/MOD 1. Agreement between test data and the calculation was generally reasonable. All major trends and phenomena were correctly predicted. We believe that the correct conclusions about trends and phenomena will be reached if the code is used in similar applications.« less

Irradiated ignition over solid materials in reduce pressure environment: Fire safety issue in man-made enclosure system

NASA Astrophysics Data System (ADS)

Nakamura, N.; Aoki, A.

Effects of ambient pressure and oxygen yield on irradiated ignition characteristics over solid combustibles have been studied experimentally Aim of the present study is to elucidate the flammability and chance of fire in depressurized enclosure system and give ideas for the fire safety and fire fighting strategies in such environment Thin cellulosic paper is considered as the solid combustible since cellulose is one of major organic compounds and flammables in the nature Applied atmosphere consists of inert gas either CO2 or N2 and oxygen and various mixture ratios are of concerned Total ambient pressure level is varied from 0 1MPa standard atmospheric pressure to 0 02MPa Ignition is initiated by external thermal flux exposed into the solid surface as a model of unexpected thermal input to initiate the localized fire Thermal degradation of the solid induces combustible gaseous products e g CO H2 or other low class of HCs and the gas mixes with ambient oxygen to form the combustible mixture over the solid Heat transfer from the hot irradiated surface into the mixture accelerates the local exothermic reaction in the gas phase and finally thermal runaway ignition is achieved Ignition event is recorded by high-speed digital video camera to analyze the ignition characteristics Flammable map in partial pressure of oxygen Pox and total ambient pressure Pt plane is made to reveal the fire hazard in depressurized environment Results show that wider flammable range is obtained depending on the imposed ambient

Investigation of the Methane Hydrate Formation by Cavitation Jet

NASA Astrophysics Data System (ADS)

Morita, H.; Nagao, J.

2015-12-01

Methane hydrate (hereafter called "MH") is crystalline solid compound consisting of hydrogen-bonded water molecules forming cages and methane gas molecules enclosed in the cage. When using MH as an energy resource, MH is dissociated to methane gas and water and collect only the methane gas. The optimum MH production method was the "depressurization method". Here, the production of MH means dissociating MH in the geologic layers and collecting the resultant methane gas by production systems. In the production of MH by depressurization method, MH regeneration was consider to important problem for the flow assurance of MH production system. Therefore, it is necessary to clarify the effect of flow phenomena in the pipeline on hydrate regeneration. Cavitation is one of the flow phenomena which was considered a cause of MH regeneration. Large quantity of microbubbles are produced by cavitation in a moment, therefore, it is considered to promote MH formation. In order to verify the possible of MH regeneration by cavitation, it is necessary to detailed understanding the condition of MH formation by cavitation. As a part of a Japanese National hydrate research program (MH21, funded by METI), we performed a study on MH formation using by cavitation. The primary objective of this study is to demonstrate the formation MH by using cavitation in the various temperature and pressure condition, and to clarify the condition of MH formation by using observation results.

Method for Evaluating the Corrosion Resistance of Aluminum Metallization of Integrated Circuits under Multifactorial Influence

NASA Astrophysics Data System (ADS)

Kolomiets, V. I.

2018-03-01

The influence of complex influence of climatic factors (temperature, humidity) and electric mode (supply voltage) on the corrosion resistance of metallization of integrated circuits has been considered. The regression dependence of the average time of trouble-free operation t on the mentioned factors has been established in the form of a modified Arrhenius equation that is adequate in a wide range of factor values and is suitable for selecting accelerated test modes. A technique for evaluating the corrosion resistance of aluminum metallization of depressurized CMOS integrated circuits has been proposed.

Anxiety and anxiety disorders. Toward a conceptual reorientation.

PubMed

Curtis, G C

1985-03-01

Traditionally, it has been assumed that there is only one type of anxiety; recent pharmacologic evidence suggests that there may be several. The psychoanalytic concept of "neurotic" symptoms as depressurizing mechanisms is out of keeping with most evidence now available. Spontaneous or "free-floating" anxiety may be partly biologic and genetic in origin. Anxiety symptoms evoked by specific stimuli behave in part like conditioned responses. Where conditioning theory has failed to propose a plausible unconditioned stimulus for pathologic anxiety, biology, ethology, and psychoanalysis may have been more successful.

KSC-00padig050

NASA Image and Video Library

2000-10-18

This close-up shows the pager-sized Personal Cabin Pressure Altitude Monitor developed by Jan Zysko, chief of the KSC Spaceport Engineering and Technology directorate's data and electronic systems branch. The monitor alerts wearers of a potentially dangerous or deteriorating cabin pressure altitude condition, which can lead to life-threatening hypoxia. Zysko originally designed the monitor to offer Space Shuttle and Space Station crew members added independent notification about any depressurization. However, it has drawn the interest of such organizations as the Federal Aviation Administration for use in commercial airliners and private aircraft as well

Thin-metal lined PRD 49-III composite vessels. [evaluation of pressure vessels for burst strength and fatigue performance

NASA Technical Reports Server (NTRS)

Hoggatt, J. T.

1974-01-01

Filament wound pressure vessels of various configurations were evaluated for burst strength and fatigue performance. The dimensions and characteristics of the vessels are described. The types of tests conducted are explained. It was determined that all vessels leaked in a relatively few cycles (20 to 60 cycles) with failure occurring in all cases in the metallic liner. The thin liner would de-bond from the composite and buckling took place during depressurization. No composite failures or indications of impeding composite failures were obtained in the metal-lined vessels.

MEMS micromirror characterization in space environments.

PubMed

Yoo, Byung-Wook; Park, Jae-Hyoung; Park, I H; Lee, Jik; Kim, Minsoo; Jin, Joo-Young; Jeon, Jin-A; Kim, Sug-Whan; Kim, Yong-Kweon

2009-03-02

This paper describes MEMS micromirror characterization in space environments associated with our space applications in earth observation from the International Space Station and earth's orbit satellite. The performance of the micromirror was tested for shock and vibration, stiction, outgassing from depressurization and heating, and electrostatic charging effects. We demonstrated that there is no degradation of the micromirror performance after the space environment tests. A test bed instrument equipped with the micromirrors was delivered and tested in the ISS. The results demonstrate that the proposed micromirrors are suitable for optical space systems.

Energy flux and hydrogeology of thermal anomalies in the Gulf of Mexico Basin: South Texas example

NASA Astrophysics Data System (ADS)

Sharp, J. M., Jr.

1994-03-01

This report covers the period from 1 September 1993 through 28 February 1994. The last Technical Progress Report was submitted in September 1993. In this period, we have focused our efforts on the following activities: (1) Finalizing collection of radiogenic heat production data; (2) Evaluating petrographic controls on thermal conductivity; (3) Modeling one-dimensional heat conduction with sources; (4) Completing base geologic cross-section; (5) Acquiring pressure data to augment data base; (6) Putting map and well data into digital format for analysis; (7) Analyzing salinity, temperate and fluid potential data for propensity of free convection; (8) Finalizing preliminary investigation into depressurization of reservoirs; (9) Preparing presentations for AAPG meeting in Denver; (10) Presenting results at the Geological Society of America Meeting in Boston (October 1993); (11) Collaborating with project members of the DOE funded Global Basins Research Network who are working on a project in the Eugene Island Block, offshore Louisiana; and (12) Collaborating with others working on research in the Gulf of Mexico Basin in our Department and with CSIRO scientists in Adelaide, Australia.

Assessment of Mitigation Systems on Vapor Intrusion ...

EPA Pesticide Factsheets

Vapor intrusion is the migration of subsurface vapors, including radon and volatile organic compounds (VOCs), in soil gas from the subsurface to indoor air. Vapor intrusion happens because there are pressure and concentration differentials between indoor air and soil gas. Indoor environments are often negatively pressurized with respect to outdoor air and soil gas (for example, from exhaust fans or the stack effect), and this pressure difference allows soil gas containing subsurface vapors to flow into indoor air through advection. In addition, concentration differentials cause VOCs and radon to migrate from areas of higher to lower concentrations through diffusion, which is another cause of vapor intrusion. Current practice for evaluating the vapor intrusion pathway involves a multiple line of evidence approach based on direct measurements in groundwater, external soil gas, subslab soil gas, and/or indoor air. No single line of evidence is considered definitive, and direct measurements of vapor intrusion can be costly, especially where significant spatial and temporal variability require repeated measurements at multiple locations to accurately assess the chronic risks of long-term exposure to volatile organic compounds (VOCs) like chloroform, perchloroethylene (PCE), and trichloroethylene (TCE).

FINAL PROJECT REPORT - EVALUATION AND TESTING OF HTGR REACTOR BUILDING RESPONSE TO DEPRESSURIZATION ACCIDENTS

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

ALLIANCE LIMITED, NGNP INDUSTRY

This report provides a description of the project, summarizes each phase of the project, and ends with project conclusions. In addition, the report contains a descriptive index of the technical reports generated during the course of the project.

Release of Dissolved CO2 from Water in Laboratory Porous Media Following Rapid Depressurization

NASA Astrophysics Data System (ADS)

Crews, J. B.; Cooper, C. A.

2011-12-01

A bench-top laboratory study is undertaken to investigate the effects of seismic shocks on brine aquifers into which carbon dioxide has been injected for permanent storage. Long-term storage in deep saline aquifers has been proposed and studied as one of the most viable near-term options for sequestering fossil fuel-derived carbon dioxide from the atmosphere to curb anthropogenic climate change. Upon injection into the subsurface, it is expected that CO2, as either a gas or supercritical fluid, will mix convectively with the formation water. The possibility exists, however, that dissolved CO2 will come out of solution as a result of an earthquake. The effect is similar to that of slamming an unsealed container of carbonated beverage on a table; previously dissolved CO2 precipitates, forms bubbles, and rises due to buoyancy. In this study, we measure the change in gas-phase CO2 concentration as a function of the magnitude of the shock and the initial concentration of CO2. In addition, we investigate and seek to characterize the nucleation and transport of CO2 bubbles in a porous medium after a seismic shock. Experiments are conducted using a Hele-Shaw cell and a CCD camera to quantify the fraction of dissolved CO2 that comes out of solution as a result of a sharp mechanical impulse. The data are used to identify and constrain the conditions under which CO2 comes out of solution and, further, to understand the end-behavior of the precipitated gas-phase CO2 as it moves through or is immobilized in a porous medium.

Between-cycle laser system for depressurization and resealing of modified design nuclear fuel assemblies

DOEpatents

Bradley, John G.

1982-01-01

A laser beam is used to puncture fuel cladding for release of contained pressurized fission gas from plenum sections or irradiated fuel pins. Exhausted fission gases are collected and trapped for safe disposal. The laser beam, adjusted to welding mode, is subsequently used to reseal the puncture holes. The fuel assembly is returned to additional irradiation or, if at end of reactivity lifetime, is routed to reprocess. The fuel assembly design provides graded cladding lengths, by rows or arrays, such that the cladding of each component fuel element of the assembly is accessible to laser beam reception.

Mapping the hydraulic connection between a coalbed and adjacent aquifer: example of the coal-seam gas resource area, north Galilee Basin, Australia

NASA Astrophysics Data System (ADS)

Jiang, Zhenjiao; Mariethoz, Gregoire; Schrank, Christoph; Cox, Malcolm; Timms, Wendy

2016-12-01

Coal-seam gas production requires groundwater extraction from coal-bearing formations to reduce the hydraulic pressure and improve gas recovery. In layered sedimentary basins, the coalbeds are often separated from freshwater aquifers by low-permeability aquitards. However, hydraulic connection between the coalbed and aquifers is possible due to the heterogeneity in the aquitard such as the existence of conductive faults or sandy channel deposits. For coal-seam gas extraction operations, it is desirable to identify areas in a basin where the probability of hydraulic connection between the coalbed and aquifers is low in order to avoid unnecessary loss of groundwater from aquifers and gas production problems. A connection indicator, the groundwater age indictor (GAI), is proposed, to quantify the degree of hydraulic connection. The spatial distribution of GAI can indicate the optimum positions for gas/water extraction in the coalbed. Depressurizing the coalbed at locations with a low GAI would result in little or no interaction with the aquifer when compared to the other positions. The concept of GAI is validated on synthetic cases and is then applied to the north Galilee Basin, Australia, to assess the degree of hydraulic connection between the Aramac Coal Measure and the water-bearing formations in the Great Artesian Basin, which are separated by an aquitard, the Betts Creek Beds. It is found that the GAI is higher in the western part of the basin, indicating a higher risk to depressurization of the coalbed in this region due to the strong hydraulic connection between the coalbed and the overlying aquifer.

Non-Intrusive Velocity Measurements with MTV During DCC Event in the HTTF

NASA Technical Reports Server (NTRS)

Andre, M. A.; Bardet, P. M.; Cadell, S. R.; Woods, B.; Burns, R. A.; Danehy, P. M.

2017-01-01

Velocity profiles are measured using molecular tagging velocimetry (MTV) in the high temperature test facility (HTTF) at Oregon State University during a depressurized conduction cooldown (DCC) event. The HTTF is a quarter scale electrically heated nuclear reactor simulator designed to replicate various accident scenarios. During a DCC, a double ended guillotine break results in the reactor pressure vessel (RPV) depressurizing into the reactor cavity and ultimately leading to air ingress in the reactor core (lock-exchange and gas diffusion). It is critical to understand the resulting buoyancy-driven flow to characterize the reactor self-cooling capacity through natural circulation. During tests conducted at ambient pressure and temperature, the RPV containing helium is opened (via the hot and cold legs) to a large vessel filled with nitrogen to simulate the atmosphere. The velocity profile on the hot leg pipe centerline is recorded at 10 Hz with MTV based on NO tracers. The precision of the velocimetry was measured to be 0.02 m/s in quiescent flow prior to the tests. A helium flow from the RPV is initially observed in the top quarter of the pipe. During the first 20 seconds of the event, helium flows out of the RPV with a maximum velocity below 2 m/s. The velocity profile transitions from parabolic to linear in character and decays slowly over the rest of the recording; peak velocities of 0.2 m/s are observed after 30 min. A counter-flow of nitrogen is also observed intermittently, which occurs at lower velocities (>0.1 m/s).

Instability and thermal conductivity of pressure-densified and elastically altered orientational glass of Buckminsterfullerene

NASA Astrophysics Data System (ADS)

Johari, G. P.; Andersson, Ove; Sundqvist, Bertil

2018-04-01

We report on the temperature, pressure, and time (T, p, and t)-dependent features of thermal conductivity, κ, of partially ordered, non-equilibrium state of C60-OG, the orientational glass of Buckminsterfullerene (at T below the orientational freezing temperature Tog) made more unstable (i) by partially depressurizing its high-p formed state to elastically expand it and (ii) by further pressurizing that state to elastically contract it. The sub-Tog effects observed on heating of C60-OG differ from those of glasses because phonon propagation depends on the ratio of two well-defined orientational states of C60 molecules and the density of the solid. A broad peak-like feature appears at T near Tog in the κ-T plots of C60-OG formed at 0.7 GPa, depressurized to 0.2 GPa and heated at 0.2 GPa, which we attribute to partial overlap of the sub-Tog and Tog features. A sub-Tog local minimum appears in the κ-T plots at T well below Tog of C60-OG formed at 0.1 GPa, pressurized to 0.5 GPa and heated at 0.5 GPa and it corresponds to the state of maximum disorder. Although Buckminsterfullerene is regarded as an orientationally disordered crystal, variation of its properties with T and p is qualitatively different from other such crystals. We discuss the findings in terms of the nature of its disorder, sensitivity of its rotational dynamics to temperature, and the absence of the Johari-Goldstein relaxation. All seem to affect the phenomenology of its glass-like transition.

Effects of periodic atmospheric pressure variation on radon entry into buildings

NASA Astrophysics Data System (ADS)

Tsang, Y. W.; Narasimhan, T. N.

1992-06-01

Using a mathematical model, we have investigated the temporal variations of radon entry into a house basement in the presence of time-dependent periodic variations of barometric pressure as well as a persistent small steady depressurization within the basement. The tool for our investigation is an integral finite difference numerical code which can solve for both diffusive and advective flux of radon in the soil gas which is treated as a slightly compressible fluid. Two different boundary conditions at the house basement are considered: (1) a dirt floor basement so that diffusion is equally or more important than advective transport, and (2) an "impermeable" cement basement except for a 1-cm-wide crack near the perimeter of the basement floor; in which case, advective transport of radon flux dominates. Two frequencies of barometric pressure fluctuation with representative values of amplitudes, based on a Fourier decomposition of barometric pressure data, were chosen in this study: one with a short period of 0.5 hour with pressure amplitude of 50 Pa, the other a diurnal variation with a period of 24 hours with the typical pressure amplitude of 250 Pa. For a homogeneous soil medium with soil permeability to air between 10-13 and 10-10 m2, we predict that the barometric fluctuations increase the radon entry into the basement by up to 120% of the steady radon inflow into the basement owing to a steady depressurization of 5 Pa. If soil permeability heterogeneity is present, such as the presence of a thin layer of higher permeability aggregate immediately below the basement floor, radon flux due to atmospheric pumping is further increased. Effects of pressure pumping on radon entry are also compared to diffusion-only transport when the steady depressurization is absent. It is found that contribution to radon entry is significant for the basement crack configuration. In particular, for pressure pumping at 0.5-hour period and for a homogeneous medium of permeability of 10

Visualization of hydraulic connections using Borehole Array around LPG Underground Storage Cavern

NASA Astrophysics Data System (ADS)

Shimo, M.; Mashimo, H.; Maejima, T.; Aoki, K.

2006-12-01

This paper presents a systematic approach to visualize the hydraulic connections within the fractured rock mass around the underground LPG storage caverns using array of water injection boreholes. By taking advantage that water injection boreholes are located so as to cover the storage caverns, a complete sketch of hydraulic conditions around the caverns, such as locations of water conducting fractures, hydraulic conductivity and groundwater pressure can be obtained. Applicability of the proposed techniques have been tested in an on-going construction project operated by JOGMEC, Japan Oil, Gas and Metals National Corporation, at Namikata, Western part of Japan. Three 26m x 30m x 485m caverns, located at 150 - 200 m below the ground surface in a granitic rock, are under construction. By systematically monitoring the pressure responses between the neighboring boreholes during drilling of total 387 boreholes around the two propane caverns, a spatial profile of the hydraulic connections and hydraulic conductivity around the caverns has been successfully obtained. Locations of localized depressurized zones created during an arch excavation have been detected by monitoring pressure in each borehole after stopping water supply to that borehole temporarily. Measurement has been conducted using each one of the 302 boreholes, one at a time. Observation shows that there is a clear correlation between total pressure drop and pressure gradient versus time curve on semi-logarithmic plot, dH/log10t, as expected by the numerical prediction. Regions where dH/log10t is larger than a certain criteria, determined by a numerical simulation for flow around a cavern in a rock with uniform hydraulic conductivity, have been evaluated as a depressurized zone caused by insufficient water supply, possibly due to existence of the high permeable zones. Separate pore pressure measurement around the caverns also supports this interpretation that a low pressure is prevailing near the borehole

The rise and fall of periodic 'drumbeat' seismicity at Tungurahua volcano, Ecuador

NASA Astrophysics Data System (ADS)

Bell, Andrew F.; Hernandez, Stephen; Gaunt, H. Elizabeth; Mothes, Patricia; Ruiz, Mario; Sierra, Daniel; Aguaiza, Santiago

2017-10-01

Highly periodic 'drumbeat' long period (LP) earthquakes have been described from several andesitic and dacitic volcanoes, commonly accompanying incremental ascent and effusion of viscous magma. However, the processes controlling the occurrence and characteristics of drumbeat, and LP earthquakes more generally, remain contested. Here we use new quantitative tools to describe the emergence, evolution, and degradation of drumbeat LP seismicity at the andesitic Tungurahua volcano, Ecuador, in April 2015. The signals were recorded during an episode of minor explosive activity and ash emission, without lava effusion, and are the first to be reported at Tungurahua during the ongoing 17 yrs of eruption. Following four days of high levels of continuous and 'pulsed' tremor, highly-periodic LP earthquakes first appear on 10 April. Over the next four days, inter-event times and event amplitudes evolve through a series of step-wise transitions between stable behaviors, each involving a decrease in the degree of periodicity. Families of similar waveforms persist before, during, and after drumbeat activity, but the activity levels of different families change coincidentally with transitions in event rate, amplitude, and periodicity. A complex micro-seismicity 'initiation' sequence shows pulse-like and stepwise changes in inter-event times and amplitudes in the hours preceding the onset of drumbeat activity that indicate a partial de-coupling between event size and rate. The observations increase the phenomenology of drumbeat LP earthquakes, and suggest that at Tungurahua they result from gas flux and rapid depressurization controlled by shear failure of the margins of the ascending magma column.

Summary Report of Mission Acceleration Measurement for STS-87: Launched November 19, 1997

NASA Technical Reports Server (NTRS)

Rogers, Melissa J. B.; Hrovat, Kenneth; McPherson, Kevin; DeLombard, Richard; Reckart, Timothy

1999-01-01

Two accelerometer systems, the Orbital Acceleration Research Experiment and the Space Acceleration Measurement System, were used to measure and record the microgravity environment of the Orbiter Columbia during the STS-87 mission in November-December 1997. Data from two separate Space Acceleration Measurement System units were telemetered to the ground during the mission and data plots were displayed for investigators of the Fourth United States Microgravity Payload experiments in near real-time using the World Wide Web. Plots generated using Orbital Acceleration Research Experiment data (telemetered to the ground using a tape delay) were provided to the investigators using the World Wide Web approximately twelve hours after data recording. Disturbances in the microgravity environment as recorded by these instruments are grouped by source type: Orbiter systems, on-board activities, payload operations, and unknown sources. The environment related to the Ku-band antenna dither, Orbiter structural modes, attitude deadband collapses, water dump operations, crew sleep, and crew exercise was comparable to the effects of these sources on previous Orbiter missions. Disturbances related to operations of the Isothermal Dendritic Growth Experiment and Space Acceleration Measurement Systems that were not observed on previous missions are detailed. The effects of Orbiter cabin and airlock depressurization and extravehicular activities are also reported for the first time. A set of data plots representing the entire mission is included in the CD-ROM version of this report.

Shallow system rejuvenation and magma discharge trends at Piton de la Fournaise volcano (La Réunion Island)

NASA Astrophysics Data System (ADS)

Coppola, Diego; Di Muro, Andrea; Peltier, Aline; Villeneuve, Nicolas; Ferrazzini, Valerie; Favalli, Massimiliano; Bachèlery, Patrick; Gurioli, Lucia; Harris, Andrew; Moune, Séverine; Vlastélic, Ivan; Galle, Bo; Arellano, Santiago; Aiuppa, Alessandro

2017-04-01

During April 2007, the largest historical eruption of Piton de la Fournaise (Île de La Réunion, France) drained the shallow plumbing system and resulted in collapse of the summit crater. Following the 2007 eruption, Piton de la Fournaise entered a seven-year long period of near-continuous deflation interrupted, in June 2014, by a new phase of significant inflation. By integrating multiple datasets (lava discharge rates, deformation, seismicity, gas flux, gas composition, and lava chemistry), we here show that the progressive migration of magma from a deeper (below sea level) storage zone gradually rejuvenated and pressurized the above-sea-level portion of the magmatic system to provoke four small (<5 × 10 6 m3) eruptions from vents located close to the summit cone. Progressive increase in output rate between each eruption culminated, with the fifth, longest-lasting (August-October 2015) and largest-volume (45 ± 15 × 10 6 m3) eruption of the cycle. Activity observed in 2014 and 2015 points to a phase of shallow system rejuvenation and discharge, whereby continuous magma supply provoked eruptions from increasingly deeper and larger magma storage zones. Downward depressurization continued until unloading of the deepest, least differentiated magma triggered an "effusive paroxysm" that emptied the main shallow reservoir and terminated the cycle. Such an unloading process may characterize the evolution of shallow magmatic systems at other persistently active effusive centers.

Description of 103 Cases of Hypobaric Sickness from NASA-sponsored Research

NASA Technical Reports Server (NTRS)

Conkin, Johnny; Klein, Jill S.; Acock, Keena E.

2003-01-01

One hundred and three cases of hypobaric decompression sickness (DCS) are documented, with 6 classified as Type II DCS. The presence and grade of venous gas emboli (VGE) are part of the case descriptions. Cases were diagnosed from 731 exposures in 5 different altitude chambers from 4 different laboratories between the years 1982 and 1999. Research was funded by NASA to develop operational prebreathe (PB) procedures that would permit safe extravehicular activity from the Space Shuttle and International Space Station using an extravehicular mobility unit (spacesuit) operated at 4.3 psia. Both vehicles operate at 14.7 psia with an "air" atmosphere, so a PB procedure is required to reduce nitrogen partial pressure in the tissues to an acceptable level prior to depressurization to 4.3 psia. Thirty-two additional descriptions of symptoms that were not diagnosed as DCS together with VGE information are also included. The information for each case resides in logbooks from 32 different tests. Additional information is stored in the NASA Decompression Sickness Database and the Prebreathe Reduction Protocol Database, both maintained by the Environmental Physiology Laboratory at the Johnson Space Center. Both sources were reviewed to provide the narratives that follow.

STS-114: Discovery Post MMT Briefing

NASA Technical Reports Server (NTRS)

2005-01-01

On flight day 13, Leroy Cain, STS-114 Ascent/Entry Flight Director, discusses the condition of the Space Shuttle Discovery, and the weather outlook for landing. He answers questions from the news media about his feelings about re-entry since the Columbia tragedy, possible new information during re-entry, critical moments in the Mission Control Room during landing, and differences between night landing and day landing. Footage of the Mission Control Room and a talk with Soichi Noguchi in orbit is shown. Also, footage of the truss structure of the International Space Station, Destiny Laboratory, crew cabin of Discovery, and the Orbiter Docking System linked up to forward docking port on Discovery is shown. Eileen Collins and Wendy Lawrence are shown in the flight deck of Discovery. Charles Camarda is also shown in the mid-deck. Downlink television from Discovery shows spacewalk choreographer Andy Thomas with Stephen Robinson and Soichi Noguchi preparing for depressurization and pre-breathing activities that will lead to the opening of the hatch. The installation of a replacement GPS antenna, images of the port wing of Discovery and Canadarm moving with the Orbital Boom Sensor System (OBSS) extension is shown.

Sensitivity Studies on Productivity Performance from 3D Heterogeneous Reservoir Model Based on the L-Pad Gas Hydrate Accumulation in Prudhoe Bay Unit, North Slope Alaska

NASA Astrophysics Data System (ADS)

Myshakin, E. M.; Ajayi, T.; Seol, Y.; Boswell, R.

2016-12-01

Three-dimensional reservoir model of the "L-Pad" hydrate deposit located in the Prudhoe Bay region of the Alaska's North Slope was created including four stratigraphic units; silty shale overburden, hydrate-bearing D sand, inter-reservoir silty shale, hydrate-bearing C sand, and silty shale underburden. The model incorporates the actual geological settings, accounts for the presence of faults, reservoir dip, the hydrate-water contact in the C sand. Geostatistical porosity distributions in D and C sands conditioned to log data from 78 wells drilled in the vicinity of the Prudhoe Bay "L-pad" were developed providing vertical and lateral 3D heterogeneity in porosity and porosity-dependent hydrate saturation and intrinsic permeability. Gas production potential was estimated using a conventional vertical wellbore completion and a deviated toe-down wellbore perforated through both sand units to induce hydrate depressurization at a constant bottom-hole pressure. The results have shown the greater performance of the deviated well design over the vertical one. The scenarios involving simultaneous and sequential hydrate dissociation in sand units were explored and the effect of the underlying aquifer in the C sand was estimated. Sensitivity analysis has demonstrated that hydraulic communication with over- and underlying shale units affects production in the beginning of depressurization due to competitive water influx into producing mobile flow and could suppress efficient hydrate decomposition resulting in production lag. Another important factor greatly influencing the productivity performance is the effective permeability of hydrate-bearing sediment controlled by the relative permeability function. The results call for the necessity of thorough fundamental studies to understand multi-phase flow in hydrate-bearing sediments with different hydrate precipitation habits.

Near Space Lab-Rat Experimentation using Stratospheric Balloon

NASA Astrophysics Data System (ADS)

Buduru, Suneel Kumar; Reddy Vizapur, Anmi; Rao Tanneeru, Venkateswara; Trivedi, Dharmesh; Devarajan, Anand; Pandit Manikrao Kulkarni, MR..; Ojha, Devendra; Korra, Sakram; Neerudu, Nagendra; Seng, Lim; Godi, Stalin Peter

2016-07-01

First ever balloon borne lab-rat experiment up to near space stratospheric altitude levels carried out at TIFR Balloon Facility, Hydeabad using zero pressure balloons for the purpose of validating the life support system. A series of two balloon experiments conducted under joint collaboration with IN.Genius, Singapore in the year 2015. In these experiments, three lab-rats sent to stratosphere in a pressurized capsule designed to reach an altitude of 30 km by keeping constant pressure, temperature and maintained at a precise rate of oxygen supply inside the capsule. The first experiment conducted on 1 ^{st} February, 2015 with a total suspended weight of 225 kg. During the balloon ascent stage at 18 km altitude, sensors inside the capsule reported drastic drop in internal pressure while oxygen and temperatures maintained at correct levels resulted in premature fligt termination at 20.1 km. All the three lab-rats recovered without life due to the collapse of their lungs caused by the depressurization inside the capsule. The second experiment conducted on 14th March, 2015 using a newly developed capsule with rectification of depressurization fault by using improved sealing gaskets and hermitically sealed connectors for sending lab-rats again to stratosphere comprising a total suspended load of 122.3 kg. The balloon flight was terminated after reaching 29.5 km in 110 minutes and succesfully recovered all the three lab-rats alive. This paper focuses on lessons learnt of the development of the life support system as an integral pressurized vessel, flight control instrumentation, flight simulation tests using thermo-vaccum chamber with pre-flight operations.

Numerical studies of gas production from several CH4 hydrate zones at the Mallik site, Mackenzie Delta, Canada

USGS Publications Warehouse

Moridis, G.J.; Collett, T.S.; Dallimore, S.R.; Satoh, T.; Hancock, S.; Weatherill, B.

2004-01-01

The Mallik site represents an onshore permafrost-associated gas hydrate accumulation in the Mackenzie Delta, Northwest Territories, Canada. A gas hydrate research well was drilled at the site in 1998. The objective of this study is the analysis of various gas production scenarios from five methane hydrate-bearing zones at the Mallik site. In Zone #1, numerical simulations using the EOSHYDR2 model indicated that gas production from hydrates at the Mallik site was possible by depressurizing a thin free gas zone at the base of the hydrate stability field. Horizontal wells appeared to have a slight advantage over vertical wells, while multiwell systems involving a combination of depressurization and thermal stimulation offered superior performance, especially when a hot noncondensible gas was injected. Zone #2, which involved a gas hydrate layer with an underlying aquifer, could yield significant amounts of gas originating entirely from gas hydrates, the volumes of which increased with the production rate. However, large amounts of water were also produced. Zones #3, #4 and #5 were lithologically isolated gas hydrate-bearing deposits with no underlying zones of mobile gas or water. In these zones, thermal stimulation by circulating hot water in the well was used to induce dissociation. Sensitivity studies indicated that the methane release from the hydrate accumulations increased with the gas hydrate saturation, the initial formation temperature, the temperature of the circulating water in the well, and the formation thermal conductivity. Methane production appears to be less sensitive to the specific heat of the rock and of the hydrate, and to the permeability of the formation. ?? 2004 Published by Elsevier B.V.

Triaxial testing system for pressure core analysis using image processing technique

NASA Astrophysics Data System (ADS)

Yoneda, J.; Masui, A.; Tenma, N.; Nagao, J.

2013-11-01

In this study, a newly developed innovative triaxial testing system to investigate strength, deformation behavior, and/or permeability of gas hydrate bearing-sediments in deep sea is described. Transport of the pressure core from the storage chamber to the interior of the sealing sleeve of a triaxial cell without depressurization was achieved. An image processing technique was used to capture the motion and local deformation of a specimen in a transparent acrylic triaxial pressure cell and digital photographs were obtained at each strain level during the compression test. The material strength was successfully measured and the failure mode was evaluated under high confining and pore water pressures.

Environmental risks of the gas hydrate field development in the Eastern Nankai Trough

NASA Astrophysics Data System (ADS)

Yamamoto, K.; Nagakubo, S.

2009-12-01

To establish any kinds of new energy resources, environmental impacts of the technology should be well understood before full industrial implementation. Methane hydrate (MH), a relatively clean fossil energy with low CO2 and no SOx emission, is not an exception. Because methane gas itself has strong greenhouse gas effect, and methane hydrate is not stable under the atmospheric pressure and room temperature, public image of MH field development is very risky game and potentially disastrous to the global climate. However, the real physics of the MH bearing sediments is far different from such images. MH21 Research Consortium in Japan has studied about the resource assessment and production techniques to develop MH since 2001. As the results, we found several gas hydrate concentrated zones with pore filling type hydrate in sandy layers of turbidite sediment in the Eastern Nankai Trough area off coasts of the Central Japan. The depressurization technique, in the other word, in-situ MH dissociation by water production and natural heat supply from surrounding formation, will be used as the basic method to produce methane gas from MH. Under the conditions, we have evaluated realistic environmental risk of the MH production. Because the most MH found in the Eastern Nankai Trough are composed of biogenic and almost pure methane, there is no concern of sea water contamination by oil releases that is the most common environmental disaster caused by misconducts of the oil industry. Also MH reservoirs there are not pressurized, and blowout of wells during drilling is very unlikely. Endothermic MH dissociation process decreases formation temperature with depressurization, and give negative feedback, then, there is no chance of chain reaction. Heat supply from surrounding formations is necessary for continuous dissociation, but heat transfer in the formations is relatively slow, and the dissociation rate is limited. Once the operation to pump water in boreholes for

Seismic anisotropy and mantle flow in the Hellenic subduction zone: The possible effects of trench retreat and slab tear at both ends.

NASA Astrophysics Data System (ADS)

Evangelidis, Christos

2017-04-01

region nearest to the trench. The fast splitting directions change abruptly to trench-parallel above the corner of the mantle wedge and rotate back to trench-normal over the back-arc. Additionally, beneath western Greece, between the western Gulf of Corinth in the south and the Epirus-Thessaly area in the north, a transitional anisotropy pattern emerges that possibly depicts the passage from the continental to the oceanic subducted slabs and the subslab mantle flow due to the trench retreat. At the eastern side of the Hellenic arc, from eastern Crete to the Dodecanese Islands, the inferred subslab measurements of anisotropy show a general trench perpendicular pattern. This area is characterized as a STEP fault region with multiple trench normal strike slip faults. The difference between the fast roll-back in the Aegean and the slow lithospheric processes in the western Anatolia is accommodated by a broad shear zone of lithospheric deformation and a possible slab tear inferred from seismic tomography and geophysical studies but with a relative unknown geometry. Thus, the observed anisotropy pattern possibly resembles the 3D return flow around the slab edge that is caused by the inferred slab break.

Structural relaxation and thermal conductivity of high-pressure formed, high-density di-n-butyl phthalate glass and pressure induced departures from equilibrium state

NASA Astrophysics Data System (ADS)

Johari, G. P.; Andersson, Ove

2017-06-01

We report a study of structural relaxation of high-density glasses of di-n-butyl phthalate (DBP) by measuring thermal conductivity, κ, under conditions of pressure and temperature (p,T) designed to modify both the vibrational and configurational states of a glass. Various high-density glassy states of DBP were formed by (i) cooling the liquid under a fixed high p and partially depressurizing the glass, (ii) isothermal annealing of the depressurized glass, and (iii) pressurizing the glass formed by cooling the liquid under low p. At a given low p, κ of the glass formed by cooling under high p is higher than that of the glass formed by cooling under low p, and the difference increases as glass formation p is increased. κ of the glass formed under 1 GPa is ˜20% higher at ambient p than κ of the glass formed at ambient p. On heating at low p, κ decreases until the glass to liquid transition range is reached. This is the opposite of the increase in κ observed when a glass formed under a certain p is heated under the same p. At a given high p, κ of the low-density glass formed by cooling at low p is lower than that of the high-density glass formed by cooling at that high p. On heating at high p, κ increases until the glass to liquid transition range is reached. The effects observed are due to a thermally assisted approach toward equilibrium at p different from the glass formation p. In all cases, the density, enthalpy, and entropy would change until the glasses become metastable liquids at a fixed p, thus qualitatively relating κ to variation in these properties.

Japan's Methane Hydrate R&D Program, Accomplishments and Future Challenges

NASA Astrophysics Data System (ADS)

Shimada, T.

2009-12-01

JOGMEC have been searching for methane hydrate offshore around Japan for use as a future energy resource as a member of the research consortium of methane hydrate resources in Japan (MH21 Research Consortium). The MH21 Research Consortium was established in 2002 to carry out "Japan's Methane Hydrate R&D Program" published by the Ministry of Economy, Trade and Industry (METI) in July 2001. The program has been extended over 18 years (until 2018) and is divided into three phases. During phase 1, the following key accomplishments had been achieved. Revealed and confirmed the occurrence of methane hydrate filling pore spaces of sand layers in the marine environment for the first time in the eastern Nankai Trough. Established methodology to delineate the thick methane hydrate concentrated zones composed of alternations of highly hydrate-saturated turbidite sand mainly by geophysical measures. Evaluated the amount of gas trapped in the eastern Nankai Trough, applied a probabilistic method based on the borehole data and seismic data, contained in methane hydrate-bearing layers. Tested and achieved substantial methane gas production through the wellbore from subsurface hydrate-bearing layers by dissociating hydrates in Canadian arctic area under international collaboration. Both depressurization method and hot water circulation method were successfully conducted to produce methane gas, and the depressurization method was proved to be effective as a production method that could be utilized in the future. We accumulated a significant amount of knowledge and experience during phase 1. However, many technical and economic challenges still remain for the development of methane hydrate. The research program proceeded to phase 2 in 2009. This time we would like to present summary of phase 1 and challenges during phase 2. The author would like to express sincere appreciation to MH21 Research Consortium and METI for permission for this presentation.

Effect of mechanical disruption on the effectiveness of three reactors used for dilute acid pretreatment of corn stover Part 1: chemical and physical substrate analysis

PubMed Central

2014-01-01

Background There is considerable interest in the conversion of lignocellulosic biomass to liquid fuels to provide substitutes for fossil fuels. Pretreatments, conducted to reduce biomass recalcitrance, usually remove at least some of the hemicellulose and/or lignin in cell walls. The hypothesis that led to this research was that reactor type could have a profound effect on the properties of pretreated materials and impact subsequent cellulose hydrolysis. Results Corn stover was dilute-acid pretreated using commercially relevant reactor types (ZipperClave® (ZC), Steam Gun (SG) and Horizontal Screw (HS)) under the same nominal conditions. Samples produced in the SG and HS achieved much higher cellulose digestibilities (88% and 95%, respectively), compared to the ZC sample (68%). Characterization, by chemical, physical, spectroscopic and electron microscopy methods, was used to gain an understanding of the effects causing the digestibility differences. Chemical differences were small; however, particle size differences appeared significant. Sum-frequency generation vibrational spectra indicated larger inter-fibrillar spacing or randomization of cellulose microfibrils in the HS sample. Simons’ staining indicated increased cellulose accessibility for the SG and HS samples. Electron microscopy showed that the SG and HS samples were more porous and fibrillated because of mechanical grinding and explosive depressurization occurring with these two reactors. These structural changes most likely permitted increased cellulose accessibility to enzymes, enhancing saccharification. Conclusions Dilute-acid pretreatment of corn stover using three different reactors under the same nominal conditions gave samples with very different digestibilities, although chemical differences in the pretreated substrates were small. The results of the physical and chemical analyses of the samples indicate that the explosive depressurization and mechanical grinding with these reactors increased

Break modeling for RELAP5 analyses of ISP-27 Bethsy

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

Petelin, S.; Gortnar, O.; Mavko, B.

This paper presents pre- and posttest analyses of International Standard Problem (ISP) 27 on the Bethsy facility and separate RELAP5 break model tests considering the measured boundary condition at break inlet. This contribution also demonstrates modifications which have assured the significant improvement of model response in posttest simulations. Calculations were performed using the RELAP5/MOD2/36.05 and RELAP5/MOD3.5M5 codes on the MicroVAX, SUN, and CONVEX computers. Bethsy is an integral test facility that simulates a typical 900-MW (electric) Framatome pressurized water reactor. The ISP-27 scenario involves a 2-in. cold-leg break without HPSI and with delayed operator procedures for secondary system depressurization.

Pretest and posttest calculations of Semiscale Test S-07-10D with the TRAC computer program. [PWR

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

Duerre, K.H.; Cort, G.E.; Knight, T.D.

The Transient Reactor Analysis Code (TRAC) developed at the Los Alamos National Laboratory was used to predict the behavior of the small-break experiment designated Semiscale S-07-10D. This test simulates a 10 per cent communicative cold-leg break with delayed Emergency Core Coolant injection and blowdown of the broken-loop steam generator secondary. Both pretest calculations that incorporated measured initial conditions and posttest calculations that incorporated measured initial conditions and measured transient boundary conditions were completed. The posttest calculated parameters were generally between those obtained from pretest calculations and those from the test data. The results are strongly dependent on depressurization rate and,more » hence, on break flow.« less

Assessment of the leak tightness integrity of the steam generator tubes affected by ODSCC at the tube support plates

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

Cuvelliez, Ch.; Roussel, G.

1997-02-01

An EPRI report gives a method for predicting a conservative value of the total primary-to-secondary leak rate which may occur during, a postulated steam generator depressurization accident such as a Main Steam Line Break (MSLB) in a steam generator with axial through-wall ODSCC at the TSP intersections. The Belgian utility defined an alternative method deviating somewhat from the EPRI method. When reviewing this proposed method, the Belgian safety authorities performed some calculations to investigate its conservatism. This led them to recommend some modifications to the EPRI method which should reduce its undue conservatism while maintaining the objective of conservatism inmore » the offsite dose calculations.« less

KSC00padig049

NASA Image and Video Library

2000-10-01

Jan Zysko (left) and Rich Mizell (right) test a Personal Cabin Pressure Altitude Monitor in an altitude chamber at Tyndall Air Force Base in Florida. Zysko invented the pager-sized monitor that alerts wearers of a potentially dangerous or deteriorating cabin pressure altitude condition, which can lead to life-threatening hypoxia. Zysko is chief of the KSC Spaceport Engineering and Technology directorate's data and electronic systems branch. Mizell is a Shuttle processing engineer. The monitor, which has drawn the interest of such organizations as the Federal Aviation Administration for use in commercial airliners and private aircraft, was originally designed to offer Space Shuttle and Space Station crew members added independent notification about any depressurization

KSC-00padig049

NASA Image and Video Library

2000-10-01

Jan Zysko (left) and Rich Mizell (right) test a Personal Cabin Pressure Altitude Monitor in an altitude chamber at Tyndall Air Force Base in Florida. Zysko invented the pager-sized monitor that alerts wearers of a potentially dangerous or deteriorating cabin pressure altitude condition, which can lead to life-threatening hypoxia. Zysko is chief of the KSC Spaceport Engineering and Technology directorate's data and electronic systems branch. Mizell is a Shuttle processing engineer. The monitor, which has drawn the interest of such organizations as the Federal Aviation Administration for use in commercial airliners and private aircraft, was originally designed to offer Space Shuttle and Space Station crew members added independent notification about any depressurization

Method of filtering a target compound from a first solvent that is above its critical density

DOEpatents

Phelps, Max R [Richland, WA; Yonker, Clement R [Kennewick, WA; Fulton, John L [Richland, WA; Bowman, Lawrence E [Richland, WA

2001-07-24

The present invention is a method of separating a first compound having a macromolecular structure from a mixture. The first solvent is a fluid that is a gas at standard temperature and pressure and is at a density greater than a critical density of the fluid. A macromolecular structure containing a first compound is dissolved therein as a mixture. The mixture is contacted onto a selective barrier and the first solvent passed through the selective barrier thereby retaining the first compound, followed by recovering the first compound. By using a fluid that is a gas at standard temperature and pressure at a density greater than its critical density, separation without depressurization is fast and efficient.

Bill Dana in front of HL-10 after flight H-24-37

NASA Image and Video Library

1969-09-03

NASA research pilot Bill Dana after his fourth free flight (1 glide and 3 powered) in the HL-10. This particular flight reached a maximum speed of Mach 1.45. Dana made a total of nine HL-10 flights (1 glide and 8 powered), and his lifting body experience as a whole included several car tow and 1 air tow flights in the M2-F1; 4 glide and 15 powered flights in the M2-F3; and 2 powered flights in the X-24B. He is wearing a pressure suit for protection against the cockpit depressurizing at high altitudes. The air conditioner box held by the ground crewman provides cool air to prevent overheating.

Retrogradation of Maize Starch after High Hydrostatic Pressure Gelation: Effect of Amylose Content and Depressurization Rate.

PubMed

Yang, Zhi; Swedlund, Peter; Gu, Qinfen; Hemar, Yacine; Chaieb, Sahraoui

2016-01-01

High hydrostatic pressure (HHP) has been employed to gelatinize or physically modify starch dispersions. In this study, waxy maize starch, normal maize starch, and two high amylose content starch were processed by a HHP of the order of 600 MPa, at 25°C for 15min. The effect of HHP processing on the crystallization of maize starches with various amylose content during storage at 4°C was investigated. Crystallization kinetics of HHP treated starch gels were investigated using rheology and FTIR. The effect of crystallization on the mechanical properties of starch gel network were evaluated in terms of dynamic complex modulus (G*). The crystallization induced increase of short-range helices structures were investigated using FTIR. The pressure releasing rate does not affect the starch retrogradation behaviour. The rate and extent of retrogradation depends on the amylose content of amylose starch. The least retrogradation was observed in HHP treated waxy maize starch. The rate of retrogradation is higher for HHP treated high amylose maize starch than that of normal maize starch. A linear relationship between the extent of retrogradation (phase distribution) measured by FTIR and G* is proposed.

Retrogradation of Maize Starch after High Hydrostatic Pressure Gelation: Effect of Amylose Content and Depressurization Rate

PubMed Central

Yang, Zhi; Swedlund, Peter; Gu, Qinfen; Hemar, Yacine; Chaieb, Sahraoui

2016-01-01

High hydrostatic pressure (HHP) has been employed to gelatinize or physically modify starch dispersions. In this study, waxy maize starch, normal maize starch, and two high amylose content starch were processed by a HHP of the order of 600 MPa, at 25°C for 15min. The effect of HHP processing on the crystallization of maize starches with various amylose content during storage at 4°C was investigated. Crystallization kinetics of HHP treated starch gels were investigated using rheology and FTIR. The effect of crystallization on the mechanical properties of starch gel network were evaluated in terms of dynamic complex modulus (G*). The crystallization induced increase of short-range helices structures were investigated using FTIR. The pressure releasing rate does not affect the starch retrogradation behaviour. The rate and extent of retrogradation depends on the amylose content of amylose starch. The least retrogradation was observed in HHP treated waxy maize starch. The rate of retrogradation is higher for HHP treated high amylose maize starch than that of normal maize starch. A linear relationship between the extent of retrogradation (phase distribution) measured by FTIR and G* is proposed. PMID:27219066

KSC-98pc1186

NASA Image and Video Library

1998-09-30

The open doors of the payload bay on Space Shuttle Discovery await the transfer of four of the payloads on mission STS-95: the SPACEHAB single module, Spartan, the Hubble Space Telescope Orbiting Systems Test Platform (HOST), and the International Extreme Ultraviolet Hitchhiker (IEH-3). At the top of bay are the airlock (used for depressurization and repressurization during extravehicular activity and transfer to Mir) and the tunnel adapter (enables the flight crew members to transfer from the pressurized middeck crew compartment to Spacelab's pressurized shirt-sleeve environment). SPACEHAB involves experiments on space flight and the aging process. Spartan is a solar physics spacecraft designed to perform remote sensing of the hot outer layers of the sun's atmosphere or corona. HOST carries four experiments to validate components planned for installation during the third Hubble Space Telescope servicing mission and to evaluate new technologies in an Earth-orbiting environment. IEH-3 comprises several experiments that will study the Jovian planetary system, hot stars, planetary and reflection nebulae, other stellar objects and their environments through remote observation of EUV/FUV emissions; study spacecraft interactions, Shuttle glow, thruster firings, and contamination; and measure the solar constant and identify variations in the value during a solar cycle. Discovery is scheduled to launch on Oct. 29, 1998

Dome-like behaviour at Mt. Etna: The case of the 28 December 2014 South East Crater paroxysm.

PubMed

Ferlito, C; Bruno, V; Salerno, G; Caltabiano, T; Scandura, D; Mattia, M; Coltorti, M

2017-07-13

On the 28 December 2014, a violent and short paroxysmal eruption occurred at the South East Crater (SEC) of Mount Etna that led to the formation of huge niches on the SW and NE flanks of the SEC edifice from which a volume of ~3 × 10 6  m 3 of lava was erupted. Two basaltic lava flows discharged at a rate of ~370 m 3 /s, reaching a maximum distance of ~5 km. The seismicity during the event was scarce and the eruption was not preceded by any notable ground deformation, which instead was dramatic during and immediately after the event. The SO 2 flux associated with the eruption was relatively low and even decreased few days before. Observations suggest that the paroxysm was not related to the ascent of volatile-rich fresh magma from a deep reservoir (dyke intrusion), but instead to a collapse of a portion of SEC, similar to what happens on exogenous andesitic domes. The sudden and fast discharge eventually triggered a depressurization in the shallow volcano plumbing system that drew up fresh magma from depth. Integration of data and observations has allowed to formulate a novel interpretation of mechanism leading volcanic activity at Mt. Etna and on basaltic volcanoes worldwide.

Process and apparatus for the production of hydrogen by steam reforming of hydrocarbon

DOEpatents

Sircar, Shivaji; Hufton, Jeffrey Raymond; Nataraj, Shankar

2000-01-01

In the steam reforming of hydrocarbon, particularly methane, under elevated temperature and pressure to produce hydrogen, a feed of steam and hydrocarbon is fed into a first reaction volume containing essentially only reforming catalyst to partially reform the feed. The balance of the feed and the reaction products of carbon dioxide and hydrogen are then fed into a second reaction volume containing a mixture of catalyst and adsorbent which removes the carbon dioxide from the reaction zone as it is formed. The process is conducted in a cycle which includes these reactions followed by countercurrent depressurization and purge of the adsorbent to regenerate it and repressurization of the reaction volumes preparatory to repeating the reaction-sorption phase of the cycle.

Report on JANNAF panel on shotgun/relative quickness testing

NASA Technical Reports Server (NTRS)

Gould, R. A.

1980-01-01

As the need for more energetic solid propellants continues, a number of problems arises. One of these is the tendency of high energy propellants to transition from burning (deflagration) to detonation in regions where the propellant is present in small particle sizes; e.g., in case bonding areas of a motor after a rapid depressurization causes a shear zone at the bond interface as the stressed propellant and motor case relax at different rates. In an effort to determine the susceptibility of propellants to high strain rate break up (friability), and subsequent DDT, the propulsion community uses the shotgun/relative quickness test as one of a number of screening tests for new propellant formulations. Efforts to standardize test techniques and equipment are described.

International Space Station Environmental Control and Life Support Emergency Response Verification for Node 1

NASA Technical Reports Server (NTRS)

Williams, David E.

2008-01-01

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 Emergency Response capability, which includes nominal and off-nominal FDS operation, off nominal ACS operation, and off-nominal THC operation. These subsystems provide the capability to help aid the crew members during an emergency cabin depressurization, a toxic spill, or a fire. The paper will also provide a discussion of the detailed Node 1 ECLS Element Verification methodologies for operation of the Node 1 Emergency Response hardware operations utilized during the Qualification phase.

Overview of Fuel Rod Simulator Usage at ORNL

NASA Astrophysics Data System (ADS)

Ott, Larry J.; McCulloch, Reg

2004-02-01

During the 1970s and early 1980s, the Oak Ridge National Laboratory (ORNL) operated large out-of-reactor experimental facilities to resolve thermal-hydraulic safety issues in nuclear reactors. The fundamental research ranged from material mechanical behavior of fuel cladding during the depressurization phase of a loss-of-coolant accident (LOCA) to basic heat transfer research in gas- or sodium-cooled cores. The largest facility simulated the initial phase (less than 1 min. of transient time) of a LOCA in a commercial pressurized-water reactor. The nonnuclear reactor cores of these facilities were mimicked via advanced, highly instrumented electric fuel rod simulators locally manufactured at ORNL. This paper provides an overview of these experimental facilities with an emphasis on the fuel rod simulators.

Thermal-hydraulic modeling needs for passive reactors

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

Kelly, J.M.

1997-07-01

The U.S. Nuclear Regulatory Commission has received an application for design certification from the Westinghouse Electric Corporation for an Advanced Light Water Reactor design known as the AP600. As part of the design certification process, the USNRC uses its thermal-hydraulic system analysis codes to independently audit the vendor calculations. The focus of this effort has been the small break LOCA transients that rely upon the passive safety features of the design to depressurize the primary system sufficiently so that gravity driven injection can provide a stable source for long term cooling. Of course, large break LOCAs have also been considered,more » but as the involved phenomena do not appear to be appreciably different from those of current plants, they were not discussed in this paper. Although the SBLOCA scenario does not appear to threaten core coolability - indeed, heatup is not even expected to occur - there have been concerns as to the performance of the passive safety systems. For example, the passive systems drive flows with small heads, consequently requiring more precision in the analysis compared to active systems methods for passive plants as compared to current plants with active systems. For the analysis of SBLOCAs and operating transients, the USNRC uses the RELAP5 thermal-hydraulic system analysis code. To assure the applicability of RELAP5 to the analysis of these transients for the AP600 design, a four year long program of code development and assessment has been undertaken.« less

Initial characterization of the microgravity environment of the international space station: increments 2 through 4

NASA Technical Reports Server (NTRS)

Jules, Kenol; McPherson, Kevin; Hrovat, Kenneth; Kelly, Eric

2004-01-01

The primary objective of the International Space Station (ISS) is to provide a long-term quiescent environment for the conduct of scientific research for a variety of microgravity science disciplines. This paper reports to the microgravity scientific community the results of an initial characterization of the microgravity environment on the International Space Station for increments 2 through 4. During that period almost 70,000 hours of station operations and scientific experiments were conducted. 720 hours of crew research time were logged aboard the orbiting laboratory and over half a terabyte of acceleration data were recorded and much of that was analyzed. The results discussed in this paper cover both the quasi-steady and vibratory acceleration environment of the station during its first year of scientific operation. For the quasi-steady environment, results are presented and discussed for the following: the space station attitudes Torque Equilibrium Attitude and the X-Axis Perpendicular to the Orbital Plane; station docking attitude maneuvers; Space Shuttle joint operation with the station; cabin de-pressurizations and the station water dumps. For the vibratory environment, results are presented for the following: crew exercise, docking events, and the activation/de-activation of both station life support system hardware and experiment hardware. Finally, a grand summary of all the data collected aboard the station during the 1-year period is presented showing where the overall quasi-steady and vibratory acceleration magnitude levels fall over that period of time using a 95th percentile benchmark. Published by Elsevier Ltd.

EVALUATION OF ACTIVATED BIOFILTRATION AND ACTIVATED BIOFILTRATION/ACTIVATED SLUDGE TECHNOLOGIES

EPA Science Inventory

The paper presents the results of a review and investigation of the activated biofilter (ABF) and activated biofilter/activated sludge (ABF/AS) technologies and a review of operating records of several municipal plants in the U.S. using these technologies. The overall objective o...

Surface Deformation by Thermo-capillary Convection -Sounding Rocket COMPERE Experiment SOURCE

NASA Astrophysics Data System (ADS)

Fuhrmann, Eckart; Dreyer, Michael E.

The sounding rocket COMPERE experiment SOURCE was successfully flown on MASER 11, launched in Kiruna (ESRANGE), May 15th, 2008. SOURCE has been intended to partly ful-fill the scientific objectives of the European Space Agency (ESA) Microgravity Applications Program (MAP) project AO-2004-111 (Convective boiling and condensation). Three parties of principle investigators have been involved to design the experiment set-up: ZARM for thermo-capillary flows, IMFT (Toulouse, France) for boiling studies, EADS Astrium (Bremen, Ger-many) for depressurization. The scientific aims are to study the effect of wall heat flux on the contact line of the free liquid surface and to obtain a correlation for a convective heat transfer coefficient. The experiment has been conducted along a predefined time line. A preheating sequence at ground was the first operation to achieve a well defined temperature evolution within the test cell and its environment inside the rocket. Nearly one minute after launch, the pressurized test cell was filled with the test liquid HFE-7000 until a certain fill level was reached. Then the free surface could be observed for 120 s without distortion. Afterwards, the first depressurization was started to induce subcooled boiling, the second one to start saturated boiling. The data from the flight consists of video images and temperature measurements in the liquid, the solid, and the gaseous phase. Data analysis provides the surface shape versus time and the corresponding apparent contact angle. Computational analysis provides information for the determination of the heat transfer coefficient in a compensated gravity environment where a flow is caused by the temperature difference between the hot wall and the cold liquid. Correlations for the effective contact angle and the heat transfer coefficient shall be delivered as a function of the relevant dimensionsless parameters. The data will be used for benchmarking of commercial CFD codes and the tank design

Fluid Flow Patterns During Production from Gas Hydrates in the Laboratory compared to Field Settings: LARS vs. Mallik

NASA Astrophysics Data System (ADS)

Strauch, B.; Heeschen, K. U.; Priegnitz, M.; Abendroth, S.; Spangenberg, E.; Thaler, J.; Schicks, J. M.

2015-12-01

The GFZ's LArge Reservoir Simulator LARS allows for the simulation of the 2008 Mallik gas hydrate production test and the comparison of fluid flow patterns and their driving forces. Do we see the gas flow pattern described for Mallik [Uddin, M. et al., J. Can. Petrol Tech, 50, 70-89, 2011] in a pilot scale test? If so, what are the driving forces? LARS has a network of temperature sensors and an electric resistivity tomography (ERT) enabling a good spatial resolution of gas hydrate occurrences, water and gas distribution, and changes in temperature in the sample. A gas flow meter and a water trap record fluid flow patterns and a backpressure valve has controlled the depressurization equivalent to the three pressure stages (7.0 - 5.0 - 4.2 MPa) applied in the Mallik field test. The environmental temperature (284 K) and confining pressure (13 MPa) have been constant. The depressurization induced immediate endothermic gas hydrate dissociation until re-establishment of the stability conditions by a consequent temperature decrease. Slight gas hydrate dissociation continued at the top and upper lateral border due to the constant heat input from the environment. Here transport pathways were short and permeability higher due to lower gas hydrate saturation. At pressures of 7.0 and 5.0 MPa the LARS tests showed high water flow rates and short irregular spikes of gas production. The gas flow patterns at 4.2 MPa and 3.0MPa resembled those of the Mallik test. In LARS the initial gas surges overlap with times of hydrate instability while water content and lengths of pathways had increased. Water production was at a minimum. A rapidly formed continuous gas phase caused the initial gas surges and only after gas hydrate dissociation decreased to a minimum the single gas bubbles get trapped before slowly coalescing again. In LARS, where pathways were short and no additional water was added, a transport of microbubbles is unlikely to cause a gas surge as suggested for Mallik.

Density structure of submarine slump and normal sediments of the first gas production test site at Daini-Atsumi Knoll near Nankai Trough, estimated by LWD logging data

NASA Astrophysics Data System (ADS)

Suzuki, K.; Takayama, T.; Fujii, T.; Yamamoto, K.

2014-12-01

Many geologists have discussed slope instability caused by gas-hydrate dissociation, which could make movable fluid in pore space of sediments. However, physical property changes caused by gas hydrate dissociation would not be so simple. Moreover, during the period of natural gas-production from gas-hydrate reservoir applying depressurization method would be completely different phenomena from dissociation processes in nature, because it could not be caused excess pore pressure, even though gas and water exist. Hence, in all cases, physical properties of gas-hydrate bearing sediments and that of their cover sediments are quite important to consider this phenomena, and to carry out simulation to solve focusing phenomena during gas hydrate dissociation periods. Daini-Atsumi knoll that was the first offshore gas-production test site from gas-hydrate is partially covered by slumps. Fortunately, one of them was penetrated by both Logging-While-Drilling (LWD) hole and pressure-coring hole. As a result of LWD data analyses and core analyses, we have understood density structure of sediments from seafloor to Bottom Simulating Reflector (BSR). The results are mentioned as following. ・Semi-confined slump showed high-density, relatively. It would be explained by over-consolidation that was result of layer-parallel compression caused by slumping. ・Bottom sequence of slump has relative high-density zones. It would be explained by shear-induced compaction along slide plane. ・Density below slump tends to increase in depth. It is reasonable that sediments below slump deposit have been compacting as normal consolidation. ・Several kinds of log-data for estimating physical properties of gas-hydrate reservoir sediments have been obtained. It will be useful for geological model construction from seafloor until BSR. We can use these results to consider geological model not only for slope instability at slumping, but also for slope stability during depressurized period of gas

Hydro-mechanical properties of pressure core sediments recovered from the Krishna-Godavari Basin during India's National Gas Hydrate Program Expedition NGHP-02

NASA Astrophysics Data System (ADS)

Yoneda, J.; Oshima, M.; Kida, M.; Kato, A.; Konno, Y.; Jin, Y.; Waite, W. F.; Jang, J.; Kumar, P.; Tenma, N.

2017-12-01

Pressure coring and analysis technology allows for gas hydrate to be recovered from the deep seabed, transferred to the laboratory and characterized while continuously maintaining gas hydrate stability. For this study, dozens of hydrate-bearing pressure core sediment subsections recovered from the Krishna-Godavari Basin during India's National Gas Hydrate Program Expedition NGHP-02 were tested with Pressure Core Non-destructive Analysis Tools (PNATs) through a collaboration between Japan and India. PNATs, originally developed by AIST as a part of the Japanese National hydrate research program (MH21, funded by METI) conducted permeability, compression and consolidation tests under various effective stress conditions, including the in situ stress state estimated from downhole bulk density measurements. At the in situ effective stress, gas hydrate-bearing sediments had an effective permeability range of 0.01-10mD even at pore-space hydrate saturations above 60%. Permeability increased by 10 to 100 times after hydrate dissociation at the same effective stress, but these post-dissociation gains were erased when effective stress was increased from in situ values ( 1 MPa) to 10MPa in a simulation of the depressurization method for methane extraction from hydrate. Vertical-to-horizontal permeability anisotropy was also investigated. First-ever multi-stage loading tests and strain-rate alternation compression tests were successfully conducted for evaluating sediment strengthening dependence on the rate and magnitude of effective confining stress changes. In addition, oedometer tests were performed up to 40MPa of consolidation stress to simulate the depressurization method in ultra-deep sea environments. Consolidation curves measured with and without gas hydrate were investigated over a wide range of effective confining stresses. Compression curves for gas hydrate-bearing sediments were convex downward due to high hydrate saturations. Consolidation tests show that

Simulation of Unique Pressure Changing Steps and Situations in Psa Processes

NASA Technical Reports Server (NTRS)

Ebner, Armin D.; Mehrotra, Amal; Knox, James C.; LeVan, Douglas; Ritter, James A.

2007-01-01

A more rigorous cyclic adsorption process simulator is being developed for use in the development and understanding of new and existing PSA processes. Unique features of this new version of the simulator that Ritter and co-workers have been developing for the past decade or so include: multiple absorbent layers in each bed, pressure drop in the column, valves for entering and exiting flows and predicting real-time pressurization and depressurization rates, ability to account for choked flow conditions, ability to pressurize and depressurize simultaneously from both ends of the columns, ability to equalize between multiple pairs of columns, ability to equalize simultaneously from both ends of pairs of columns, and ability to handle very large pressure ratios and hence velocities associated with deep vacuum systems. These changes to the simulator now provide for unique opportunities to study the effects of novel pressure changing steps and extreme process conditions on the performance of virtually any commercial or developmental PSA process. This presentation will provide an overview of the cyclic adsorption process simulator equations and algorithms used in the new adaptation. It will focus primarily on the novel pressure changing steps and their effects on the performance of a PSA system that epitomizes the extremes of PSA process design and operation. This PSA process is a sorbent-based atmosphere revitalization (SBAR) system that NASA is developing for new manned exploration vehicles. This SBAR system consists of a 2-bed 3-step 3-layer system that operates between atmospheric pressure and the vacuum of space, evacuates from both ends of the column simultaneously, experiences choked flow conditions during pressure changing steps, and experiences a continuously changing feed composition, as it removes metabolic CO2 and H20 from a closed and fixed volume, i.e., the spacecraft cabin. Important process performance indicators of this SBAR system are size, and the

Cascade Storage and Delivery System for a Multi Mission Space Exploration Vehicle (MMSEV)

NASA Technical Reports Server (NTRS)

Yagoda, Evan; Swickrath, Michael; Stambaugh, Imelda

2012-01-01

NASA is developing a Multi Mission Space Exploration Vehicle (MMSEV) for missions beyond Low Earth Orbit (LEO). The MMSEV is a pressurized vehicle used to extend the human exploration envelope for Lunar, Near Earth Object (NEO), and Deep Space missions. The Johnson Space Center is developing the Environmental Control and Life Support System (ECLSS) for the MMSEV. The MMSEV s intended use is to support longer sortie lengths with multiple Extra Vehicular Activities (EVAs) on a higher magnitude than any previous vehicle. This paper presents an analysis of a high pressure oxygen cascade storage and delivery system that will accommodate the crew during long duration Intra Vehicular Activity (IVA) and capable of multiple high pressure oxygen fills to the Portable Life Support System (PLSS) worn by the crew during EVAs. A cascade is a high pressure gas cylinder system used for the refilling of smaller compressed gas cylinders. Each of the large cylinders are filled by a compressor, but the cascade system allows small cylinders to be filled without the need of a compressor. In addition, the cascade system is useful as a "reservoir" to accommodate low pressure needs. A regression model was developed to provide the mechanism to size the cascade systems subject to constraints such as number of crew, extravehicular activity duration and frequency, and ullage gas requirements under contingency scenarios. The sizing routine employed a numerical integration scheme to determine gas compressibility changes during depressurization and compressibility effects were captured using the Soave-Redlich-Kwong (SRK) equation of state. A multi-dimensional nonlinear optimization routine was used to find the minimum cascade tank system mass that meets the mission requirements. The sizing algorithms developed in this analysis provide a powerful framework to assess cascade filling, compressor, and hybrid systems to design long duration vehicle ECLSS architecture. 1

Interaction between regional and magma-induced stresses and their impact on volcano-tectonic seismicity

NASA Astrophysics Data System (ADS)

Vargas-Bracamontes, D. M.; Neuberg, J. W.

2012-10-01

Recent seismological observations have reported volcano-tectonic (VT) earthquakes with fault-plane solutions exhibiting a change of ~ 90° in their pressure axes relative to the regional stress field. Interestingly, they are recorded mainly during periods preceding eruptive activity and coexisting with those VTs showing a regional trend. This study explains the occurrence of such trends in VT seismicity and discusses the possible patterns of earthquake locations related to the interaction of regional and magma-induced stresses caused by pressurization or depressurization of magmatic sources. Our analysis shows that in the presence of a dominant regional stress field, faulting will occur on faults whose associated slip direction is close to or in agreement with the background regional stress. Failure on faults with an opposite slip direction is unlikely to occur. As magma pressure starts counter-acting the regional stresses, the likelihood of faults to slip in either a regional or opposite sense of slip relative to regional maximum compression increases, allowing the co-existence of possible failure with both slip tendencies, however the spatial distribution of possible faulting differs. As the pressure is progressively increased, the stress patterns gradually approach those corresponding to the absence of a regional stress field. The presented modeling results have implications for volcanic monitoring routines aiming to detect changes in stress patterns. They will ultimately help to improve the correct interpretation of volcano-tectonic seismicity.

Experiment data report for Semiscale Mod-1 Test S-05-1 (alternate ECC injection test)

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

Feldman, E. M.; Patton, Jr., M. L.; Sackett, K. E.

Recorded test data are presented for Test S-05-1 of the Semiscale Mod-1 alternate ECC injection test series. These tests are among several Semiscale Mod-1 experiments conducted to investigate the thermal and hydraulic phenomena accompanying a hypothesized loss-of-coolant accident in a pressurized water reactor (PWR) system. Test S-05-1 was conducted from initial conditions of 2263 psia and 544/sup 0/F to investigate the response of the Semiscale Mod-1 system to a depressurization and reflood transient following a simulated double-ended offset shear of the cold leg broken loop piping. During the test, cooling water was injected into the vessel lower plenum to simulatemore » emergency core coolant injection in a PWR, with the flow rate based on system volume scaling.« less

Functional wettability in carbonate reservoirs

DOE PAGES

Brady, Patrick V.; Thyne, Geoffrey

2016-10-11

Oil adsorbs to carbonate reservoirs indirectly through a relatively thick separating water layer, and directly to the surface through a relatively thin intervening water layer. Whereas directly sorbed oil desorbs slowly and incompletely in response to changes in reservoir conditions, indirectly sorbed oil can be rapidly desorbed by changing the chemistry of the separating water layer. The additional recovery might be as much as 30% original oil in place (OOIP) above the ~30% OOIP recovered from carbonates through reservoir depressurization (primary production) and viscous displacement (waterflooding). Electrostatic adhesive forces are the dominant control over carbonate reservoir wettability. A surface complexationmore » model that quantifies electrostatic adhesion accurately predicts oil recovery trends for carbonates. Furthermore, the approach should therefore be useful for estimating initial wettability and designing fluids that improve oil recovery.« less

Characterization and physical properties of hydrate bearing sediments

NASA Astrophysics Data System (ADS)

Terzariol, M.; Santamarina, C.

2016-12-01

The amount of carbon trapped in hydrates is estimated to be larger than in conventional oil and gas reservoirs, thus methane hydrate is a promising energy resource. The high water pressure and the relatively low temperature needed for hydrate stability restrict the distribution of methane hydrates to continental shelves and permafrost regions. Stability conditions add inherent complexity to coring, sampling, handling, testing and data interpretation, have profound implications on potential production strategies. Thus a novel technology is developed for handling, transferring, and testing of natural hydrate bearing sediments without depressurization in order to preserve the sediment structure. Results from the first deployment of these tools on natural samples from Nankai Trough, Japan will also be summarized. Finally, to avoid consequences of poor sampling, a new multi-sensor in-situ characterization tool will be introduced.

A User's Guide for the Spacecraft Fire Safety Facility

NASA Technical Reports Server (NTRS)

Goldmeer, Jeffrey S.

2000-01-01

The Spacecraft Fire Safety Facility (SFSF) is a test facility that can be flown on NASA's reduced gravity aircraft to perform various types of combustion experiments under a variety of experimental conditions. To date, this facility has flown numerous times on the aircraft and has been used to perform experiments ranging from an examination of the effects transient depressurization on combustion, to ignition and flame spread. A list of pubfications/presentations based on experiments performed in the SFSF is included in the reference section. This facility consists of five main subsystems: combustion chamber, sample holders, gas flow system, imaging system, and the data acquisition/control system. Each of these subsystems will be reviewed in more detail. These subsystems provide the experiment operator with the ability to monitor and/or control numerous experimental parameters.

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

Kastenberg, W.E.; Apostolakis, G.; Dhir, V.K.

Severe accident management can be defined as the use of existing and/or altemative resources, systems and actors to prevent or mitigate a core-melt accident. For each accident sequence and each combination of severe accident management strategies, there may be several options available to the operator, and each involves phenomenological and operational considerations regarding uncertainty. Operational uncertainties include operator, system and instrumentation behavior during an accident. A framework based on decision trees and influence diagrams has been developed which incorporates such criteria as feasibility, effectiveness, and adverse effects, for evaluating potential severe accident management strategies. The framework is also capable ofmore » propagating both data and model uncertainty. It is applied to several potential strategies including PWR cavity flooding, BWR drywell flooding, PWR depressurization and PWR feed and bleed.« less

Seismological aspects of the 1989-1990 eruptions at redoubt volcano, Alaska: the SSAM perspective

USGS Publications Warehouse

Stephens, C.D.; Chouet, B.A.; Page, R.A.; Lahr, J.C.; Power, J.A.

1994-01-01

become progressively shorter for successive swarms. These trends in the relative onset times and intensities of successive precursory LP swarms are consistent with an overall depressurization of the magmatic system through time. In general, each of the swarms had an emergent onset, but the intensities did not always increase steadily until the eruptions. Instead, as the time of an eruption approached the intensity usually increased more rapidly before peaking and then declining prior to the eruption; for three of the swarms, two distinct peaks in intensity were apparent. The time intervals between final peaks in swarm intensity and ensuing eruptions ranged from about 2 hours to almost 2 days, but the peaks always occurred closer to the eruptions than to the swarm onsets. Both the onset of LP swarm activity and a decline in intensity prior to an eruption may represent critical points in the process of pressurization that drives the flow of fluids and gas in a sealed magmatic system. A notable exception to this pattern is the eruption of March 9 which lacked a detectable precursory LP swarm, but was followed by an unusually long period of strong LP seismicity that may have been stimulated by a depressurization of the magmatic system resulting from dome failure. On both December 14 and January 2, the spectra of early syn-eruptive signals have peaked signatures much like those of the spectra of precursory LP activity from shortly before the eruptions; these similarities may indicate that the source of precursory seismicity continued to be active during at least the early part of each eruption. In syn-eruptive signals from March and April recorded at stations on the volcanic edifice, the dominant spectral energy progressively shifts with time during the eruption to lower frequencies; at least part of the energy in these signals may have been generated by the debris flows associated with dome failures. ?? 1994.

Quantification of vapor intrusion pathways into a slab-on-ground building under varying environmental conditions.

PubMed

Patterson, Bradley M; Davis, Greg B

2009-02-01

Potential hydrocarbon-vapor intrusion pathways into a building through a concrete slab-on-ground were investigated and quantified under a variety of environmental conditions to elucidate the potential mechanisms for indoor air contamination. Vapor discharge from the uncovered open ground soil adjacent to the building and subsequent advection into the building was unlikely due to the low soil-gas concentrations at the edge of the building as a result of aerobic biodegradation of hydrocarbon vapors. When the building's interior was under ambient pressure, a flux of vapors into the building due to molecular diffusion of vapors through the building's concrete slab (cyclohexane 11 and methylcyclohexane 31 mg m(-2) concrete slab day(-1)) and short-term (up to 8 h) cyclical pressure-driven advection of vapors through an artificial crack (cyclohexane 4.2 x 10(3) and methylcyclohexane 1.2 x 10(4) mg m(-2) cracks day(-1)) was observed. The average subslab vapor concentration under the center of the building was 25,000 microg L(-1). Based on the measured building's interiorvapor concentrations and the building's air exchange rate of 0.66 h(-1), diffusion of vapors through the concrete slab was the dominantvapor intrusion pathway and cyclical pressure exchanges resulted in a near zero advective flux. When the building's interior was under a reduced pressure (-12 Pa), advective transport through cracks or gaps in the concrete slab (cyclohexane 340 and methylcyclohexane 1100 mg m(-2) cracks day(-1)) was the dominant vapor intrusion pathway.

Gaps, tears and seismic anisotropy around the subducting slabs of the Antilles

NASA Astrophysics Data System (ADS)

Schlaphorst, David; Kendall, J.-Michael; Baptie, Brian; Latchman, Joan L.; Tait, Steve

2017-02-01

Seismic anisotropy in and beneath the subducting slabs of the Antilles is investigated using observations of shear-wave splitting. We use a combination of teleseismic and local events recorded at three-component broadband seismic stations on every major island in the area to map anisotropy in the crust, the mantle wedge and the slab/sub-slab mantle. To date this is the most comprehensive study of anisotropy in this region, involving 52 stations from 8 seismic networks. Local event delay times (0.21 ± 0.12 s) do not increase with depth, indicating a crustal origin in anisotropy and an isotropic mantle wedge. Teleseismic delay times are much larger (1.34 ± 0.47 s), with fast shear-wave polarisations that are predominantly parallel to trend of the arc. These observations can be interpreted three ways: (1) the presence of pre-existing anisotropy in the subducting slab; (2) anisotropy due to sub-slab mantle flow around the eastern margin of the nearly stationary Caribbean plate; (3) some combination of both mechanisms. However, there are two notable variations in the trench-parallel pattern of anisotropy - trench-perpendicular alignment is observed in narrow regions east of Puerto Rico and south of Martinique. These observations support previously proposed ideas of eastward sublithospheric mantle flow through gaps in the slab. Furthermore, the pattern of anisotropy south of Martinique, near Saint Lucia is consistent with a previously proposed location for the boundary between the North and South American plates.

Indoor Radon Concentration Related to Different Radon Areas and Indoor Radon Prediction

NASA Astrophysics Data System (ADS)

Juhásová Šenitková, Ingrid; Šál, Jiří

2017-12-01

Indoor radon has been observed in the buildings at areas with different radon risk potential. Preventive measures are based on control of main potential radon sources (soil gas, building material and supplied water) to avoid building of new houses above recommended indoor radon level 200 Bq/m3. Radon risk (index) estimation of individual building site bedrock in case of new house siting and building protection according technical building code are obligatory. Remedial actions in buildings built at high radon risk areas were carried out principally by unforced ventilation and anti-radon insulation. Significant differences were found in the level of radon concentration between rooms where radon reduction techniques were designed and those where it was not designed. The mathematical model based on radon exhalation from soil has been developed to describe the physical processes determining indoor radon concentration. The model is focused on combined radon diffusion through the slab and advection through the gap from sub-slab soil. In this model, radon emanated from building materials is considered not having a significant contribution to indoor radon concentration. Dimensional analysis and Gauss-Newton nonlinear least squares parametric regression were used to simplify the problem, identify essential input variables and find parameter values. The presented verification case study is introduced for real buildings with respect to various underground construction types. Presented paper gives picture of possible mathematical approach to indoor radon concentration prediction.

Active-oxygen scavenging activity of plant extracts.

PubMed

Masaki, H; Sakaki, S; Atsumi, T; Sakurai, H

1995-01-01

To find antioxidative compounds present in plants, 65 types of plant extract were tested using the neotetrazolium method for evidence of superoxide anion-scavenging effects and 7 plant extracts were selected for further investigation. The activity of active-oxygen scavengers such as superoxide anion radicals, hydroxyl radicals, singlet oxygens and lipid peroxides in the 7 plant extracts (Aeseclus hippocastanum L., Hamamelis virginiana L. Polygonum cuspidatum Sieb., Quercus robur L., Rosemarinous officinalis L., Salvia officinalis L. and Sanguisorba officinalis L.) was examined in detail by both ESR spin-trapping and malondialdehyde generation. Furthermore, the active-oxygen scavenging activity of these plant extracts was evaluated using a murine dermal fibroblast culture system. Both Aeseclus hippocastanum L. and Hamamelis virginia L. were found to have strong active-oxygen scavenging activity of and protective activity against cell damage induced by active oxygen. Both Aeseclus hippocastanum L. and Hamamelis virginiana L. are proposed as potent plant extracts with potential application as anti-aging or anti-wrinkle material for the skin.

Automated activity-aware prompting for activity initiation.

PubMed

Holder, Lawrence B; Cook, Diane J

2013-01-01

Performing daily activities without assistance is important to maintaining an independent functional lifestyle. As a result, automated activity prompting systems can potentially extend the period of time that adults can age in place. In this paper we introduce AP, an algorithm to automate activity prompting based on smart home technology. AP learns prompt rules based on the time when activities are typically performed as well as the relationship between activities that normally occur in a sequence. We evaluate the AP algorithm based on smart home datasets and demonstrate its ability to operate within a physical smart environment.

The Interplay Between Saline Fluid Flow and Dynamic Permeability in Magmatic-Hydrothermal Systems

NASA Astrophysics Data System (ADS)

Weis, P.

2014-12-01

Magmatic-hydrothermal ore deposits document the interplay between saline fluid flow and rock permeability. Numerical simulations of multi-phase flow of variably miscible, compressible H20-NaCl fluids in concert with a dynamic permeability model can reproduce characteristics of porphyry copper and epithermal gold systems. This dynamic permeability model incorporates depth-dependent permeability profiles characteristic for tectonically active crust as well as pressure- and temperature-dependent relationships describing hydraulic fracturing and the transition from brittle to ductile rock behavior. In response to focused expulsion of magmatic fluids from a crystallizing upper crustal magma chamber, the hydrothermal system self-organizes into a hydrological divide, separating an inner part dominated by ascending magmatic fluids under near-lithostatic pressures from a surrounding outer part dominated by convection of colder meteoric fluids under near-hydrostatic pressures. This hydrological divide also provides a mechanism to transport magmatic salt through the crust, and prevents the hydrothermal system to become "clogged" by precipitation of solid halite due to depressurization of saline, high-temperature magmatic fluids. The same physical processes at similar permeability ranges, crustal depths and flow rates are relevant for a number of active systems, including geothermal resources and excess degassing at volcanos. The simulations further suggest that the described mechanism can separate the base of free convection in high-enthalpy geothermal systems from the magma chamber as a driving heat source by several kilometers in the vertical direction in tectonic settings with hydrous magmatism. This hydrology would be in contrast to settings with anhydrous magmatism, where the base of the geothermal systems may be closer to the magma chamber.

Large-scale physical activity data reveal worldwide activity inequality

PubMed Central

Althoff, Tim; Sosič, Rok; Hicks, Jennifer L.; King, Abby C.; Delp, Scott L.; Leskovec, Jure

2018-01-01

Understanding the basic principles that govern physical activity is needed to curb the global pandemic of physical inactivity1–7 and the 5.3 million deaths per year associated with in-activity2. Our knowledge, however, remains limited owing to the lack of large-scale measurements of physical activity patterns across free-living populations worldwide1, 6. Here, we leverage the wide usage of smartphones with built-in accelerometry to measure physical activity at planetary scale. We study a dataset consisting of 68 million days of physical activity for 717,527 people, giving us a window into activity in 111 countries across the globe. We find inequality in how activity is distributed within countries and that this inequality is a better predictor of obesity prevalence in the population than average activity volume. Reduced activity in females contributes to a large portion of the observed activity inequality. Aspects of the built environment, such as the walkability of a city, were associated with less gender gap in activity and activity inequality. In more walkable cities, activity is greater throughout the day and throughout the week, across age, gender, and body mass index (BMI) groups, with the greatest increases in activity for females. Our findings have implications for global public health policy and urban planning and highlight the role of activity inequality and the built environment for improving physical activity and health. PMID:28693034

Is Enhanced Physical Activity Possible Using Active Videogames?

PubMed

Baranowski, Tom; Baranowski, Janice; O'Connor, Teresia; Lu, Amy Shirong; Thompson, Debbe

2012-06-01

Our research indicated that 10-12-year-old children receiving two active Wii ™ (Nintendo ® ; Nintendo of America, Inc., Redmond, WA) console videogames were no more physically active than children receiving two inactive videogames. Research is needed on how active videogames may increase physical activity.

Is active travel associated with greater physical activity? The contribution of commuting and non-commuting active travel to total physical activity in adults.

PubMed

Sahlqvist, Shannon; Song, Yena; Ogilvie, David

2012-09-01

To complement findings that active travel reduces the risk of morbidity and mortality from chronic diseases, an understanding of the mechanisms through which active travel may lead to improved health is required. The aim of this study is to examine the descriptive epidemiology of all active travel and its associations with recreational and total physical activity in a sample of adults in the UK. In April 2010, data were collected from 3516 adults as part of the baseline survey for the iConnect study in the UK. Travel and recreational physical activity were assessed using detailed seven-day recall instruments. Linear regression analyses, controlling for demographic characteristics, examined associations between active travel, defined as any walking and cycling for transport, and recreational and total physical activity. 65% of respondents (mean age 50.5 years) reported some form of active travel, accumulating an average of 195 min/week (standard deviation=188.6). There were no differences in the recreational physical activity levels of respondents by travel mode category. Adults who used active travel did however report significantly higher total physical activity than those who did not. Substantial physical activity can be accumulated through active travel which also contributes to greater total physical activity. Copyright © 2012 Elsevier Inc. All rights reserved.

Is Enhanced Physical Activity Possible Using Active Videogames?

PubMed Central

Baranowski, Janice; O'Connor, Teresia; Lu, Amy Shirong; Thompson, Debbe

2012-01-01

Abstract Our research indicated that 10–12-year-old children receiving two active Wii™ (Nintendo®; Nintendo of America, Inc., Redmond, WA) console videogames were no more physically active than children receiving two inactive videogames. Research is needed on how active videogames may increase physical activity. PMID:24416640

Crack propagation and arrest in pressurized containers

NASA Technical Reports Server (NTRS)

Erdogan, F.; Delale, F.; Owczarek, J. A.

1976-01-01

The problem of crack propagation and arrest in a finite volume cylindrical container filled with pressurized gas is considered. It is assumed that the cylinder contains a symmetrically located longitudinal part-through crack with a relatively small net ligament. The net ligament suddenly ruptures initiating the process of fracture propagation and depressurization in the cylinder. Thus the problem is a coupled gas dynamics and solid mechanics problem the exact formulation of which does not seem to be possible. The problem is reduced to a proper initial value problem by introducing a dynamic fracture criterion which relates the crack acceleration to the difference between a load factor and the corresponding strength parameter. The results indicate that generally in gas filled cylinders fracture arrest is not possible unless the material behaves in a ductile manner and the container is relatively long.

Periodic buckling of constrained cylindrical elastic shells

NASA Astrophysics Data System (ADS)

Marthelot, Joel; Brun, Pierre-Thomas; Lopez Jimenez, Francisco; Reis, Pedro M.

We revisit the classic problem of buckling of a thin cylindrical elastic shell loaded either by pneumatic depressurization or axial compression. The control of the resulting dimpled pattern is achieved by using a concentric inner rigid mandrel that constrains and stabilizes the post-buckling response. Under axial compression, a regular lattice of diamond-like dimples appears sequentially on the surface of the shell to form a robust spatially extended periodic pattern. Under pressure loading, a periodic array of ridges facets the surface of the elastic cylindrical shell. The sharpness of these ridges can be readily varied and controlled through a single scalar parameter, the applied pressure. A combination of experiments, simulations and scaling analyses is used to rationalize the combined role of geometry and mechanics in the nucleation and evolution of the diamond-like dimples and ridges networks.

SRB frustrum 'smiley' cracking phenomenon study

NASA Technical Reports Server (NTRS)

Cruse, Thomas A.

1993-01-01

The thermal protection system installed on the SRB frustrums incurs the formation of debonds between the MSA-2 TPS material and the substrate. The debonds can lead to surface penetrating cracks, called 'smileys' near sealed fasteners and other surface discontinuities. The study concluded that the 'smileys' were caused as the result of stress risers caused by excess fastener sealant (PR-1422) and weakly bonded surfaces. Once the debond occurs, 'smileys' form when the debond area is sufficiently large. The loading for the debond and 'smiley' formation is seen to be depressurization at the vacuum conditions near the end of powered boost. The porous nature of the MSA-2 material covered by a vapor barrier paint provides internal pressure loading of the MSA-2 material. Recommendations for eliminating the problem include elimination of excess PR-1422 sealant and improved attention to bonding surface preparation.

Potential radiological impact of tornadoes on the safety of Nuclear Fuel Services' West Valley Fuel Reprocessing Plant. 2. Reentrainment and discharge of radioactive materials

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

Davis, W Jr

1981-07-01

This report describes results of a parametric study of quantities of radioactive materials that might be discharged by a tornado-generated depressurization on contaminated process cells within the presently inoperative Nuclear Fuel Services' (NFS) fuel reprocessing facility near West Valley, New York. The study involved the following tasks: determining approximate quantities of radioactive materials in the cells and characterizing particle-size distribution; estimating the degree of mass reentrainment from particle-size distribution and from air speed data presented in Part 1; and estimating the quantities of radioactive material (source term) released from the cells to the atmosphere. The study has shown that improperlymore » sealed manipulator ports in the Process Mechanical Cell (PMC) present the most likely pathway for release of substantial quantities of radioactive material in the atmosphere under tornado accident conditions at the facility.« less

Study of noise transmission through double wall aircraft windows

NASA Technical Reports Server (NTRS)

Vaicaitis, R.

1983-01-01

Analytical and experimental procedures were used to predict the noise transmitted through double wall windows into the cabin of a twin-engine G/A aircraft. The analytical model was applied to optimize cabin noise through parametric variation of the structural and acoustic parameters. The parametric study includes mass addition, increase in plexiglass thickness, decrease in window size, increase in window cavity depth, depressurization of the space between the two window plates, replacement of the air cavity with a transparent viscoelastic material, change in stiffness of the plexiglass material, and different absorptive materials for the interior walls of the cabin. It was found that increasing the exterior plexiglass thickness and/or decreasing the total window size could achieve the proper amount of noise reduction for this aircraft. The total added weight to the aircraft is then about 25 lbs.

CD18 activation epitopes induced by leukocyte activation.

PubMed

Beals, C R; Edwards, A C; Gottschalk, R J; Kuijpers, T W; Staunton, D E

2001-12-01

The cell surface adhesion molecule LFA-1 coordinates leukocyte trafficking and is a costimulatory molecule for T cell activation. We developed a panel of mAbs that recognize activation epitopes on the CD18 subunit, and show that stimulation of T lymphocytes appears to be accompanied by a conformational change in a subpopulation of LFA-1 that does not require ligand binding. Activation epitope up-regulation requires divalent cations, is sensitive to cellular signal transduction events, and correlates with cell adhesion. In addition, the stimulated appearance of these activation epitopes is absent in cell lines from patients with leukocyte adhesion deficiency-1/variant that has previously been shown to be defective in LFA-1 activation. Thus, these activation epitope Abs can be used to dissect signal transmission to CD18. Evidence suggests that these CD18 activation epitopes are induced early in cellular activation and are independent of actin rearrangement necessary for avid adhesion. We have also determined that function-blocking CD18 Abs inhibit the induction of activation epitopes. One activation epitope Ab binds to a site on CD18 distinct from that of the blocking Abs, indicating that the blocking Abs suppress a conformational change in LFA-1. We also find that these neoepitopes are present on rLFA-1 with high affinity for ICAM-1 and their binding is modulated in parallel with the affinity of LFA-1 for ICAM-1. Collectively, these neoepitope Abs identify a subpopulation of LFA-1 most likely with high affinity for ICAM-1 and necessary for LFA-1 function.

Active nematic gels as active relaxing solids

NASA Astrophysics Data System (ADS)

Turzi, Stefano S.

2017-11-01

I propose a continuum theory for active nematic gels, defined as fluids or suspensions of orientable rodlike objects endowed with active dynamics, that is based on symmetry arguments and compatibility with thermodynamics. The starting point is our recent theory that models (passive) nematic liquid crystals as relaxing nematic elastomers. The interplay between viscoelastic response and active dynamics of the microscopic constituents is naturally taken into account. By contrast with standard theories, activity is not introduced as an additional term of the stress tensor, but it is added as an external remodeling force that competes with the passive relaxation dynamics and drags the system out of equilibrium. In a simple one-dimensional channel geometry, we show that the interaction between nonuniform nematic order and activity results in either a spontaneous flow of particles or a self-organization into subchannels flowing in opposite directions.

Gamma Band Activity in the Reticular Activating System

PubMed Central

Urbano, Francisco J.; Kezunovic, Nebojsa; Hyde, James; Simon, Christen; Beck, Paige; Garcia-Rill, Edgar

2012-01-01

This review considers recent evidence showing that cells in three regions of the reticular activating system (RAS) exhibit gamma band activity, and describes the mechanisms behind such manifestation. Specifically, we discuss how cells in the mesopontine pedunculopontine nucleus (PPN), intralaminar parafascicular nucleus (Pf), and pontine subcoeruleus nucleus dorsalis (SubCD) all fire in the beta/gamma band range when maximally activated, but no higher. The mechanisms behind this ceiling effect have been recently elucidated. We describe recent findings showing that every cell in the PPN have high-threshold, voltage-dependent P/Q-type calcium channels that are essential, while N-type calcium channels are permissive, to gamma band activity. Every cell in the Pf also showed that P/Q-type and N-type calcium channels are responsible for this activity. On the other hand, every SubCD cell exhibited sodium-dependent subthreshold oscillations. A novel mechanism for sleep–wake control based on well-known transmitter interactions, electrical coupling, and gamma band activity is described. The data presented here on inherent gamma band activity demonstrates the global nature of sleep–wake oscillation that is orchestrated by brainstem–thalamic mechanism, and questions the undue importance given to the hypothalamus for regulation of sleep–wakefulness. The discovery of gamma band activity in the RAS follows recent reports of such activity in other subcortical regions like the hippocampus and cerebellum. We hypothesize that, rather than participating in the temporal binding of sensory events as seen in the cortex, gamma band activity manifested in the RAS may help stabilize coherence related to arousal, providing a stable activation state during waking and paradoxical sleep. Most of our thoughts and actions are driven by pre-conscious processes. We speculate that continuous sensory input will induce gamma band activity in the RAS that could participate in the processes of

Potent antitumor activity of a urokinase-activated engineered anthrax toxin

NASA Astrophysics Data System (ADS)

Liu, Shihui; Aaronson, Hannah; Mitola, David J.; Leppla, Stephen H.; Bugge, Thomas H.

2003-01-01

The acquisition of cell-surface urokinase plasminogen activator activity is a hallmark of malignancy. We generated an engineered anthrax toxin that is activated by cell-surface urokinase in vivo and displays limited toxicity to normal tissue but broad and potent tumoricidal activity. Native anthrax toxin protective antigen, when administered with a chimeric anthrax toxin lethal factor, Pseudomonas exotoxin fusion protein, was extremely toxic to mice, causing rapid and fatal organ damage. Replacing the furin activation sequence in anthrax toxin protective antigen with an artificial peptide sequence efficiently activated by urokinase greatly attenuated toxicity to mice. In addition, the mutation conferred cell-surface urokinase-dependent toxin activation in vivo, as determined by using a panel of plasminogen, plasminogen activator, plasminogen activator receptor, and plasminogen activator inhibitor-deficient mice. Surprisingly, toxin activation critically depended on both urokinase plasminogen activator receptor and plasminogen in vivo, showing that both proteins are essential cofactors for the generation of cell-surface urokinase. The engineered toxin displayed potent tumor cell cytotoxicity to a spectrum of transplanted tumors of diverse origin and could eradicate established solid tumors. This tumoricidal activity depended strictly on tumor cell-surface plasminogen activation. The data show that a simple change of protease activation specificity converts anthrax toxin from a highly lethal to a potent tumoricidal agent.

Evaluating Active U: an internet-mediated physical activity program

PubMed Central

Buis, Lorraine R; Poulton, Timothy A; Holleman, Robert G; Sen, Ananda; Resnick, Paul J; Goodrich, David E; Palma-Davis, LaVaughn; Richardson, Caroline R

2009-01-01

Background Engaging in regular physical activity can be challenging, particularly during the winter months. To promote physical activity at the University of Michigan during the winter months, an eight-week Internet-mediated program (Active U) was developed providing participants with an online physical activity log, goal setting, motivational emails, and optional team participation and competition. Methods This study is a program evaluation of Active U. Approximately 47,000 faculty, staff, and graduate students were invited to participate in the online Active U intervention in the winter of 2007. Participants were assigned a physical activity goal and were asked to record each physical activity episode into the activity log for eight weeks. Statistics for program reach, effectiveness, adoption, and implementation were calculated using the Re-Aim framework. Multilevel regression analyses were used to assess the decline in rates of data entry and goal attainment during the program, to assess the likelihood of joining a team by demographic characteristics, to test the association between various predictors and the number of weeks an individual met his or her goal, and to analyze server load. Results Overall, 7,483 individuals registered with the Active U website (≈16% of eligible), and 79% participated in the program by logging valid data at least once. Staff members, older participants, and those with a BMI < 25 were more likely to meet their weekly physical activity goals, and average rate of meeting goals was higher among participants who joined a competitive team compared to those who participated individually (IRR = 1.28, P < .001). Conclusion Internet-mediated physical activity interventions that focus on physical activity logging and goal setting while incorporating team competition may help a significant percentage of the target population maintain their physical activity during the winter months. PMID:19744311

Youth Physical Activity Resources Use and Activity Measured by Accelerometry

PubMed Central

Maslow, Andréa L.; Colabianchi, Natalie

2014-01-01

Objectives To examine whether utilization of physical activity resources (eg, parks) was associated with daily physical activity measured by accelerometry. Methods 111 adolescents completed a travel diary with concurrent accelerometry. The main exposure was self-reported utilization of a physical activity resource (none/1+ resources). The main outcomes were total minutes spent in daily 1) moderate-vigorous physical activity and 2) vigorous physical activity. Results Utilizing a physical activity resource was significantly associated with total minutes in moderate-vigorous physical activity. African-Americans and males had significantly greater moderate-vigorous physical activity. Conclusions Results from this study support the development and use of physical activity resources. PMID:21204684

Youth physical activity resource use and activity measured by accelerometry.

PubMed

Maslow, Andréa L; Colabianchi, Natalie

2011-01-01

To examine whether use of physical activity resources (eg, parks) was associated with daily physical activity measured by accelerometry. One hundred eleven adolescents completed a travel diary with concurrent accelerometry. The main exposure was self-reported use of a physical activity resource (none /1+ resources). The main outcomes were total minutes spent in daily (1) moderate-vigorous physical activity and (2) vigorous physical activity. Using a physical activity resource was significantly associated with total minutes in moderate-vigorous physical activity. African Americans and males had significantly greater moderate-vigorous physical activity. Results from this study support the development and use of physical activity resources.

Prothrombin activation on the activated platelet surface optimizes expression of procoagulant activity

PubMed Central

Wood, Jeremy P.; Silveira, Jay R.; Maille, Nicole M.; Haynes, Laura M.

2011-01-01

Effective hemostasis relies on the timely formation of α-thrombin via prothrombinase, a Ca2+-dependent complex of factors Va and Xa assembled on the activated platelet surface, which cleaves prothrombin at Arg271 and Arg320. Whereas initial cleavage at Arg271 generates the inactive intermediate prethrombin-2, initial cleavage at Arg320 generates the enzymatically active intermediate meizothrombin. To determine which of these intermediates is formed when prothrombin is processed on the activated platelet surface, the cleavage of prothrombin, and prothrombin mutants lacking either one of the cleavage sites, was monitored on the surface of either thrombin- or collagen-activated platelets. Regardless of the agonist used, prothrombin was initially cleaved at Arg271 generating prethrombin-2, with α-thrombin formation quickly after via cleavage at Arg320. The pathway used was independent of the source of factor Va (plasma- or platelet-derived) and was unaffected by soluble components of the platelet releasate. When both cleavage sites are presented within the same substrate molecule, Arg271 effectively competes against Arg320 (with an apparent IC50 = 0.3μM), such that more than 90% to 95% of the initial cleavage occurs at Arg271. We hypothesize that use of the prethrombin-2 pathway serves to optimize the procoagulant activity expressed by activated platelets, by limiting the anticoagulant functions of the alternate intermediate, meizothrombin. PMID:21131592

Prothrombin activation on the activated platelet surface optimizes expression of procoagulant activity.

PubMed

Wood, Jeremy P; Silveira, Jay R; Maille, Nicole M; Haynes, Laura M; Tracy, Paula B

2011-02-03

Effective hemostasis relies on the timely formation of α-thrombin via prothrombinase, a Ca(2+)-dependent complex of factors Va and Xa assembled on the activated platelet surface, which cleaves prothrombin at Arg271 and Arg320. Whereas initial cleavage at Arg271 generates the inactive intermediate prethrombin-2, initial cleavage at Arg320 generates the enzymatically active intermediate meizothrombin. To determine which of these intermediates is formed when prothrombin is processed on the activated platelet surface, the cleavage of prothrombin, and prothrombin mutants lacking either one of the cleavage sites, was monitored on the surface of either thrombin- or collagen-activated platelets. Regardless of the agonist used, prothrombin was initially cleaved at Arg271 generating prethrombin-2, with α-thrombin formation quickly after via cleavage at Arg320. The pathway used was independent of the source of factor Va (plasma- or platelet-derived) and was unaffected by soluble components of the platelet releasate. When both cleavage sites are presented within the same substrate molecule, Arg271 effectively competes against Arg320 (with an apparent IC(50) = 0.3μM), such that more than 90% to 95% of the initial cleavage occurs at Arg271. We hypothesize that use of the prethrombin-2 pathway serves to optimize the procoagulant activity expressed by activated platelets, by limiting the anticoagulant functions of the alternate intermediate, meizothrombin.

Stated Uptake of Physical Activity Rewards Programmes Among Active and Insufficiently Active Full-Time Employees.

PubMed

Ozdemir, Semra; Bilger, Marcel; Finkelstein, Eric A

2017-10-01

Employers are increasingly relying on rewards programmes in an effort to promote greater levels of activity among employees; however, if enrolment in these programmes is dominated by active employees, then they are unlikely to be a good use of resources. This study uses a stated-preference survey to better understand who participates in rewards-based physical activity programmes, and to quantify stated uptake by active and insufficiently active employees. The survey was fielded to a national sample of 950 full-time employees in Singapore between 2012 and 2013. Participants were asked to choose between hypothetical rewards programmes that varied along key dimensions and whether or not they would join their preferred programme if given the opportunity. A mixed logit model was used to analyse the data and estimate predicted uptake for specific programmes. We then simulated employer payments based on predictions for the percentage of each type of employee likely to meet the activity goal. Stated uptake ranged from 31 to 67% of employees, depending on programme features. For each programme, approximately two-thirds of those likely to enrol were insufficiently active. Results showed that insufficiently active employees, who represent the majority, are attracted to rewards-based physical activity programmes, and at approximately the same rate as active employees, even when enrolment fees are required. This suggests that a programme with generous rewards and a modest enrolment fee may have strong employee support and be within the range of what employers may be willing to spend.

Activated coconut shell charcoal carbon using chemical-physical activation

NASA Astrophysics Data System (ADS)

Budi, Esmar; Umiatin, Nasbey, Hadi; Bintoro, Ridho Akbar; Wulandari, Futri; Erlina

2016-02-01

The use of activated carbon from natural material such as coconut shell charcoal as metal absorbance of the wastewater is a new trend. The activation of coconut shell charcoal carbon by using chemical-physical activation has been investigated. Coconut shell was pyrolized in kiln at temperature about 75 - 150 °C for about 6 hours in producing charcoal. The charcoal as the sample was shieved into milimeter sized granule particle and chemically activated by immersing in various concentration of HCl, H3PO4, KOH and NaOH solutions. The samples then was physically activated using horizontal furnace at 400°C for 1 hours in argon gas environment with flow rate of 200 kg/m3. The surface morphology and carbon content of activated carbon were characterized by using SEM/EDS. The result shows that the pores of activated carbon are openned wider as the chemical activator concentration is increased due to an excessive chemical attack. However, the pores tend to be closed as further increasing in chemical activator concentration due to carbon collapsing.

Activity flow over resting-state networks shapes cognitive task activations.

PubMed

Cole, Michael W; Ito, Takuya; Bassett, Danielle S; Schultz, Douglas H

2016-12-01

Resting-state functional connectivity (FC) has helped reveal the intrinsic network organization of the human brain, yet its relevance to cognitive task activations has been unclear. Uncertainty remains despite evidence that resting-state FC patterns are highly similar to cognitive task activation patterns. Identifying the distributed processes that shape localized cognitive task activations may help reveal why resting-state FC is so strongly related to cognitive task activations. We found that estimating task-evoked activity flow (the spread of activation amplitudes) over resting-state FC networks allowed prediction of cognitive task activations in a large-scale neural network model. Applying this insight to empirical functional MRI data, we found that cognitive task activations can be predicted in held-out brain regions (and held-out individuals) via estimated activity flow over resting-state FC networks. This suggests that task-evoked activity flow over intrinsic networks is a large-scale mechanism explaining the relevance of resting-state FC to cognitive task activations.

Activity flow over resting-state networks shapes cognitive task activations

PubMed Central

Cole, Michael W.; Ito, Takuya; Bassett, Danielle S.; Schultz, Douglas H.

2016-01-01

Resting-state functional connectivity (FC) has helped reveal the intrinsic network organization of the human brain, yet its relevance to cognitive task activations has been unclear. Uncertainty remains despite evidence that resting-state FC patterns are highly similar to cognitive task activation patterns. Identifying the distributed processes that shape localized cognitive task activations may help reveal why resting-state FC is so strongly related to cognitive task activations. We found that estimating task-evoked activity flow (the spread of activation amplitudes) over resting-state FC networks allows prediction of cognitive task activations in a large-scale neural network model. Applying this insight to empirical functional MRI data, we found that cognitive task activations can be predicted in held-out brain regions (and held-out individuals) via estimated activity flow over resting-state FC networks. This suggests that task-evoked activity flow over intrinsic networks is a large-scale mechanism explaining the relevance of resting-state FC to cognitive task activations. PMID:27723746

Effects of Geomechanical Mechanism on the Gas Production Behavior: A Simulation Study of Class-3 Type Four-Way-Closure Ridge Hydrate Deposit Offshore Southwestern Taiwan

NASA Astrophysics Data System (ADS)

Wu, Cheng-Yueh; Chiu, Yung-Cheng; Huang, Yi-Jyun; Hsieh, Bieng-Zih

2017-04-01

The future energy police of Taiwan will heavily rely on the clean energy, including renewable energy and low-carbon energy, to meet the target of mitigating CO2 emission. In addition to developing the renewable energies like solar and wind resources, Taiwan will increase the natural gas consumption to obtain enough electrical power with low-carbon emission. The vast resources of gas hydrates recognized in southwestern offshore Taiwan makes a great opportunity for Taiwan to have own energy resources in the future. Therefore, Taiwan put significant efforts on the evaluation of gas hydrate reserves recently. Production behavior of natural gas dissociated from gas hydrate deposits is an important issue to the hydrate reserves evaluation. The depressurization method is a useful engineering recovery method for gas production from a class-3 type hydrate deposit. The dissociation efficiency will be affected by the pressure drawdown disturbance. However, when the pore pressure of hydrate deposits is depressurized for gas production, the rock matrix will surfer more stresses and the formation deformation might be occurred. The purpose of this study was to investigate the effects of geomechanical mechanism on the gas production from a class-3 hydrate deposit using depressurization method. The case of a class-3 type hydrate deposit of Four-Way-Closure Ridge was studied. In this study a reservoir simulator, STARS, was used. STARS is a multiphase flow, heat transfer, geo-chemical and geo-mechanical mechanisms coupling simulator which is capable to simulate the dissociation/reformation of gas hydrate and the deformation of hydrate reservoirs and overburdens. The simulating ability of STARTS simulator was validated by duplicating the hydrate comparison projects of National Energy Technology Lab. The study target, Four-Way-Closure (FWC) Ridge hydrate deposit, was discovered by the bottom simulating reflectors (BSRs). The geological parameters were collected from the geological and

Modeling Patterns of Activities using Activity Curves

PubMed Central

Dawadi, Prafulla N.; Cook, Diane J.; Schmitter-Edgecombe, Maureen

2016-01-01

Pervasive computing offers an unprecedented opportunity to unobtrusively monitor behavior and use the large amount of collected data to perform analysis of activity-based behavioral patterns. In this paper, we introduce the notion of an activity curve, which represents an abstraction of an individual’s normal daily routine based on automatically-recognized activities. We propose methods to detect changes in behavioral routines by comparing activity curves and use these changes to analyze the possibility of changes in cognitive or physical health. We demonstrate our model and evaluate our change detection approach using a longitudinal smart home sensor dataset collected from 18 smart homes with older adult residents. Finally, we demonstrate how big data-based pervasive analytics such as activity curve-based change detection can be used to perform functional health assessment. Our evaluation indicates that correlations do exist between behavior and health changes and that these changes can be automatically detected using smart homes, machine learning, and big data-based pervasive analytics. PMID:27346990

Modeling Patterns of Activities using Activity Curves.

PubMed

Dawadi, Prafulla N; Cook, Diane J; Schmitter-Edgecombe, Maureen

2016-06-01

Pervasive computing offers an unprecedented opportunity to unobtrusively monitor behavior and use the large amount of collected data to perform analysis of activity-based behavioral patterns. In this paper, we introduce the notion of an activity curve , which represents an abstraction of an individual's normal daily routine based on automatically-recognized activities. We propose methods to detect changes in behavioral routines by comparing activity curves and use these changes to analyze the possibility of changes in cognitive or physical health. We demonstrate our model and evaluate our change detection approach using a longitudinal smart home sensor dataset collected from 18 smart homes with older adult residents. Finally, we demonstrate how big data-based pervasive analytics such as activity curve-based change detection can be used to perform functional health assessment. Our evaluation indicates that correlations do exist between behavior and health changes and that these changes can be automatically detected using smart homes, machine learning, and big data-based pervasive analytics.

Parents’ Activity-Related Parenting Practices Predict Girls’ Physical Activity

PubMed Central

DAVISON, KIRSTEN KRAHNSTOEVER; CUTTING, TANJA M.; BIRCH, LEANN L.

2008-01-01

Purpose Using a sample of 180 9-yr-old girls and their parents, this study examined (a) parents’ activity-related parenting strategies and similarities and differences in such strategies for mothers and fathers, and (b) links between activity-related parenting strategies and girls’ physical activity patterns. Methods Measures of girls’ physical activity included the Children’s Physical Activity scale, participation in organized sports, and physical fitness. We developed a questionnaire to assess ways in which parents promote physical activity among their children. Results Exploratory and confirmatory factor analyses identified two factors for each parent including logistic support of girls’ activity (i.e., enrolling girls in sports and driving them to events) and parents’ explicit modeling (i.e., the extent to which parents used their own behavior to encourage their daughters to be active). Mothers reported significantly higher levels of logistic support than fathers, whereas fathers reported higher levels of explicit modeling than mothers. Although mothers and fathers tended to report different methods of support, both methods were associated with higher physical activity among girls. Finally, girls reported significantly higher levels of physical activity when at least one parent reported high levels of overall support in comparison to no parents; no significant differences were identified for support from one versus two parents. Conclusion Results from this study indicate the positive contribution that parents can have on activity practices of their young daughters. PMID:12972881

Incorporation of Socio-scientific Content into Active Learning Activities

NASA Astrophysics Data System (ADS)

King, D. B.; Lewis, J. E.; Anderson, K.; Latch, D.; Sutheimer, S.; Webster, G.; Moog, R.

2014-12-01

Active learning has gained increasing support as an effective pedagogical technique to improve student learning. One way to promote active learning in the classroom is the use of in-class activities in place of lecturing. As part of an NSF-funded project, a set of in-class activities have been created that use climate change topics to teach chemistry content. These activities use the Process Oriented Guided Inquiry Learning (POGIL) methodology. In this pedagogical approach a set of models and a series of critical thinking questions are used to guide students through the introduction to or application of course content. Students complete the activities in their groups, with the faculty member as a facilitator of learning. Through assigned group roles and intentionally designed activity structure, process skills, such as teamwork, communication, and information processing, are developed during completion of the activity. Each of these climate change activities contains a socio-scientific component, e.g., social, ethical and economic data. In one activity, greenhouse gases are used to explain the concept of dipole moment. Data about natural and anthropogenic production rates, global warming potential and atmospheric lifetimes for a list of greenhouse gases are presented. The students are asked to identify which greenhouse gas they would regulate, with a corresponding explanation for their choice. They are also asked to identify the disadvantages of regulating the gas they chose in the previous question. In another activity, where carbon sequestration is used to demonstrate the utility of a phase diagram, students use economic and environmental data to choose the best location for sequestration. Too often discussions about climate change (both in and outside the classroom) consist of purely emotional responses. These activities force students to use data to support their arguments and hypothesize about what other data could be used in the corresponding discussion to

Seismic studies in the southern Puna plateau and the Peruvian Andes

NASA Astrophysics Data System (ADS)

Calixto Mory, Frank Jimmy

I present three studies in two regions, both within the Central Andes. In both regions it is clear that there are significant variations in the subduction geometry. I have used surface wave tomography to investigate the shear wave velocity structure beneath the southern Puna plateau and found evidence of widespread melting of the crust beneath the high elevations which correlates with a gap in intermediate depth seismicity and the recent eruptions of ignimbrite complexes. All of these observations can be explained by the delamination of the lithospheric mantle beneath it. I measured Rayleigh wave phase velocities as a function of frequency and inverted then to obtain shear wave velocities as a function of depth. The results show a high velocity body sitting above the subducting Nazca plate beneath the northern edge of the Cerro Galan ignimbrite. This high velocity body is interpreted to be the delaminated piece of lithosphere that detached and sank leading to a localized upwelling of asthenosphere that, in turn, caused widespread crustal melting leading to the eruption of the most recent ignimbrite complexes. Furthermore it is possible that this upwelling also thermally eroded the slab in this region. It is apparent that there is a significant slab gap or hole where there are very few intermediate depth earthquakes. In addition, I have used shear wave splitting analysis and shear wave splitting tomography in the southern Puna plateau to investigate the patterns of seismic anisotropy and mantle flow. The results show very complex shear wave splitting and seismic anisotropy patterns throughout the southern Puna plateau. The observations suggest that different mechanisms are driving the mantle flow from region to region. The subslab mantle outside the region where delamination took place is mostly driven by slab roll back and small degree of coupling between the subducting slab and the mantle below it. In the region apparently dominated by delamination, the subslab

Activity computer program for calculating ion irradiation activation

NASA Astrophysics Data System (ADS)

Palmer, Ben; Connolly, Brian; Read, Mark

2017-07-01

A computer program, Activity, was developed to predict the activity and gamma lines of materials irradiated with an ion beam. It uses the TENDL (Koning and Rochman, 2012) [1] proton reaction cross section database, the Stopping and Range of Ions in Matter (SRIM) (Biersack et al., 2010) code, a Nuclear Data Services (NDS) radioactive decay database (Sonzogni, 2006) [2] and an ENDF gamma decay database (Herman and Chadwick, 2006) [3]. An extended version of Bateman's equation is used to calculate the activity at time t, and this equation is solved analytically, with the option to also solve by numeric inverse Laplace Transform as a failsafe. The program outputs the expected activity and gamma lines of the activated material.

Sirtuin activators.

PubMed

Alcaín, Francisco J; Villalba, José M

2009-04-01

Sirtuin 1-7 (SIRT1-7) are deacetylases that are dependent on NAD(+) for their activity. SIRT1 down-regulates p53 activity, increasing lifespan, cell survival, and neuroprotection; it also deacetylates peroxisome proliferator-activated receptor-gamma and its coactivator 1alpha, promoting fat mobilization, increasing mitochondrial size and number, and positively regulating insulin secretion. Sirtuins link nutrient availability and energy metabolism. Calorie restriction, which increases lifespan and is beneficial in age-related disorders, activates sirtuin. Major efforts are thus focused to developing sirtuin activators. After discussing the potential involvement of sirtuins in pathophysiological processes, this review looks at new, synthetic sirtuin activators. To date, resveratrol is the most potent natural compound able to activate SIRT1, mimicking the positive effect of calorie restriction. Resveratrol might help in the treatment or prevention of obesity and in preventing the aging-related decline in heart function and neuronal loss. As resveratrol has low bioavailability and interacts with multiple molecular targets, the development of new molecules with better bioavailability and targeting sirtuin at lower concentrations is a promising field of the medicinal chemistry. New SIRT1 activators that are up to 1000 times more effective than resveratrol have recently been identified. These improve the response to insulin and increase the number and activity of mitochondria in obese mice. Human trials with a formulation of resveratrol with improved bioavailability and with a synthetic SIRT1 activator are in progress.

Older people and 'active ageing': Subjective aspects of ageing actively.

PubMed

Stenner, Paul; McFarquhar, Tara; Bowling, Ann

2011-04-01

Following a critical overview of the active ageing concept, a thematic decomposition of 42 transcribed interviews with British people aged 72 years and over indicates that active ageing is understood in relation to physical, cognitive, psychological and social factors, but that these co-exist in complex combinations. The notion of activity in active ageing is grasped in relation to an active/passive distinction which emphasizes the enhancement or diminishment of concrete powers of activity. A 'challenge and response' framework is suggested for future research on active ageing.

Space Suit Environment Testing of the Orion Atmosphere Revitalization Technology

NASA Technical Reports Server (NTRS)

Lin, Amy; Sweterlitsch, Jeffrey; Cox, Marlon

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 two 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 human metabolic loads. Another paper at this year s conference discusses similar testing with real human metabolic loads, including some closed-loop testing with emergency breathing masks. The Orion ARS is designed to also support extravehicular activity operations from a depressurized cabin. The next step in developmental testing at JSC was, therefore, to test this ARS technology in a typical closed space suit loop environment with low-pressure pure oxygen inside the process loop and vacuum outside the loop. This was the first instance of low-pressure oxygen loop testing of a new Orion ARS technology, and was conducted with simulated human metabolic loads in December 2008. The test investigated pressure drops through two different styles of prototype suit umbilical connectors and general swing-bed performance with both umbilical configurations as well as with a short jumper line installed in place of the umbilicals. Other interesting results include observations on the thermal effects of swing-bed operation in a vacuum environment and a recommendation of cycle time to maintain acceptable atmospheric CO2 and moisture levels.

Active-R filter

DOEpatents

Soderstrand, Michael A.

1976-01-01

An operational amplifier-type active filter in which the only capacitor in the circuit is the compensating capacitance of the operational amplifiers, the various feedback and coupling elements being essentially solely resistive.

Is enhanced physical activity possible using active videogames?

USDA-ARS?s Scientific Manuscript database

Our research indicated that 10– to 12-year-old children receiving two active Wii (TM)(Nintendo (R); Nintendo of America, Inc., Redmond, WA) console videogames were no more physically active than children receiving two inactive videogames. Research is needed on how active videogames may increase phys...

101 Environmental Education Activities. Booklet 4--Science Activities.

ERIC Educational Resources Information Center

Whitney, Helen, Comp.

Fourth in the series "101 Environmental Education Activities" by the Upper Mississippi River ECO-Center, the booklet contains 39 environment-based science activities directed to students in primary, intermediate, and junior high classes. Organization of the activities usually includes grade level, objectives, procedures, and materials,…

Migration Imaging of the Java Subduction Zones

NASA Astrophysics Data System (ADS)

Dokht, Ramin M. H.; Gu, Yu Jeffrey; Sacchi, Mauricio D.

2018-02-01

Imaging of tectonically complex regions can greatly benefit from dense network data and resolution enhancement techniques. Conventional methods in the analysis of SS precursors stack the waveforms to obtain an average discontinuity depth, but smearing due to large Fresnel zones can degrade the fine-scale topography on the discontinuity. To provide a partial solution, we introduce a depth migration algorithm based on the common scattering point method while considering nonspecular diffractions from mantle transition zone discontinuities. Our analysis indicates that, beneath the Sunda arc, the depth of the 410 km discontinuity (the 410) is elevated by 30 km and the 660 km discontinuity (the 660) is depressed by 20-40 km; the region of the strongest anticorrelation is correlated with the morphology of the subducting Indo-Australian slab. In eastern Java, a "flat" 410 coincides with a documented slab gap, showing length scales greater than 400 km laterally and 200 km vertically. This observation could be explained by the arrival of a buoyant oceanic plateau at the Java trench at approximately 8 Ma ago, which may have caused a temporary cessation of subduction and formed a tear in the subducting slab. Our results highlight contrasting depths of the 410 and 660 along the shallow-dipping slab below the Banda trench. The 660, however, becomes significantly uplifted beneath the Banda Sea, which is accompanied by enhanced reflection amplitudes. We interpret these observations as evidence for a subslab low-velocity zone, possibly related to the lower mantle upwelling beneath the subducting slab.

Microfabricated gas chromatograph for on-site determinations of TCE in indoor air arising from vapor intrusion. 2. Spatial/temporal monitoring.

PubMed

Kim, Sun Kyu; Burris, David R; Bryant-Genevier, Jonathan; Gorder, Kyle A; Dettenmaier, Erik M; Zellers, Edward T

2012-06-05

We demonstrate the use of two prototype Si-microfabricated gas chromatographs (μGC) for continuous, short-term measurements of indoor trichloroethylene (TCE) vapor concentrations related to the investigation of TCE vapor intrusion (VI) in two houses. In the first house, with documented TCE VI, temporal variations in TCE air concentrations were monitored continuously for up to 48 h near the primary VI entry location under different levels of induced differential pressure (relative to the subslab). Concentrations ranged from 0.23 to 27 ppb by volume (1.2-150 μg/m(3)), and concentration trends agreed closely with those determined from concurrent reference samples. The sensitivity and temporal resolution of the measurements were sufficiently high to detect transient fluctuations in concentration resulting from short-term changes in variables affecting the extent of VI. Spatial monitoring showed a decreasing TCE concentration gradient with increasing distance from the primary VI entry location. In the second house, with no TCE VI, spatial profiles derived from the μGC prototype data revealed an intentionally hidden source of TCE within a closet, demonstrating the capability for locating non-VI sources. Concentrations measured in this house ranged from 0.51 to 56 ppb (2.7-300 μg/m(3)), in good agreement with reference method values. This first field demonstration of μGC technology for automated, near-real-time, selective VOC monitoring at low- or subppb levels augurs well for its use in short- and long-term on-site analysis of indoor air in support of VI assessments.

Regimes of plume-slab interaction and consequences for hotspot volcanism

NASA Astrophysics Data System (ADS)

Druken, Kelsey; Stegman, Dave; Kincaid, Christopher; Griffiths, Ross

2013-04-01

"Hotspot" volcanism is generally attributed to upwelling of anomalously warm mantle plumes, the intra-plate Hawaiian island chain and its simple age progression serving as an archetypal example. However, interactions of such plumes with plate margins, and in particular with subduction zones, is likely to have been a common occurrence and leads to more complicated geological records. Here we present results from a series of complementary, three-dimensional numerical and laboratory experiments that examine the dynamic interaction between negatively buoyant subducting slabs and positively buoyant mantle plumes. Slab-driven flow is shown to significantly influence the evolution and morphology of nearby plumes, which leads to a range of deformation regimes of the plume head and conduit. The success or failure of an ascending plume head to reach the lithosphere depends on the combination of plume buoyancy and position within the subduction system, where the mantle flow owing to downdip and rollback components of slab motion entrain plume material both vertically and laterally. Plumes rising within the sub-slab region tend to be suppressed by the surrounding flow field, while wedge-side plumes experience a slight enhancement before ultimately being entrained by subduction. Hotspot motion is more complex than that expected at intraplate settings and is primarily controlled by position alone. Regimes include severely deflected conduits as well as retrograde (corkscrew) motion from rollback-driven flow, often with weak and variable age-progression. The interaction styles and surface manifestations of plumes can be predicted from these models, and the results have important implications for potential hotspot evolution near convergent margins.

Subduction disfigured mantle plumes: Plumes that are not plumes?

NASA Astrophysics Data System (ADS)

Druken, K. A.; Stegman, D. R.; Kincaid, C. R.; Griffiths, R. W.

2012-12-01

"Hotspot" volcanism is generally attributed to upwelling of anomalously warm mantle plumes, the intra-plate Hawaiian island chain and its simple age progression serving as an archetypal example. However, interactions of such plumes with plate margins, and in particular with subduction zones, is likely to have been a common occurrence and leads to more complicated geological records. Here we present results from a series of complementary, three-dimensional numerical and laboratory experiments that examine the dynamic interaction between negatively buoyant subducting slabs and positively buoyant mantle plumes. Slab-driven flow is shown to significantly influence the evolution and morphology of nearby plumes, which leads to a range of deformation regimes of the plume head and conduit. The success or failure of an ascending plume head to reach the lithosphere depends on the combination of plume buoyancy and position within the subduction system, where the mantle flow owing to downdip and rollback components of slab motion entrain plume material both vertically and laterally. Plumes rising within the sub-slab region tend to be suppressed by the surrounding flow field, while wedge-side plumes experience a slight enhancement before ultimately being entrained by subduction. Hotspot motion is more complex than that expected at intraplate settings and is primarily controlled by position alone. Regimes include severely deflected conduits as well as retrograde (corkscrew) motion from rollback-driven flow, often with weak and variable age-progression. The interaction styles and surface manifestations of plumes can be predicted from these models, and the results have important implications for potential hotspot evolution near convergent margins.

Lipid-induced NOX2 activation inhibits autophagic flux by impairing lysosomal enzyme activity[S

PubMed Central

Jaishy, Bharat; Zhang, Quanjiang; Chung, Heaseung S.; Riehle, Christian; Soto, Jamie; Jenkins, Stephen; Abel, Patrick; Cowart, L. Ashley; Van Eyk, Jennifer E.; Abel, E. Dale

2015-01-01

Autophagy is a catabolic process involved in maintaining energy and organelle homeostasis. The relationship between obesity and the regulation of autophagy is cell type specific. Despite adverse consequences of obesity on cardiac structure and function, the contribution of altered cardiac autophagy in response to fatty acid overload is incompletely understood. Here, we report the suppression of autophagosome clearance and the activation of NADPH oxidase (Nox)2 in both high fat-fed murine hearts and palmitate-treated H9C2 cardiomyocytes (CMs). Defective autophagosome clearance is secondary to superoxide-dependent impairment of lysosomal acidification and enzyme activity in palmitate-treated CMs. Inhibition of Nox2 prevented superoxide overproduction, restored lysosome acidification and enzyme activity, and reduced autophagosome accumulation in palmitate-treated CMs. Palmitate-induced Nox2 activation was dependent on the activation of classical protein kinase Cs (PKCs), specifically PKCβII. These findings reveal a novel mechanism linking lipotoxicity with a PKCβ-Nox2-mediated impairment in pH-dependent lysosomal enzyme activity that diminishes autophagic turnover in CMs. PMID:25529920

Plant cysteine proteases that evoke itch activate protease-activated receptors

PubMed Central

Reddy, V.B.; Lerner, E.A.

2013-01-01

Background Bromelain, ficin and papain are cysteine proteases from plants that produce itch upon injection into skin. Their mechanism of action has not been considered previously. Objectives To determine the mechanism by which these proteases function. Methods The ability of these proteases to activate protease-activated receptors was determined by ratiometric calcium imaging. Results We show here that bromelain, ficin and papain activate protease-activated receptors 2 and 4. Conclusions Bromelain, ficin and papain function as signalling molecules and activate protease-activated receptors. Activation of these receptors is the likely mechanism by which these proteases evoke itch. PMID:20491769

Global optogenetic activation of inhibitory interneurons during epileptiform activity.

PubMed

Ledri, Marco; Madsen, Marita Grønning; Nikitidou, Litsa; Kirik, Deniz; Kokaia, Merab

2014-02-26

Optogenetic techniques provide powerful tools for bidirectional control of neuronal activity and investigating alterations occurring in excitability disorders, such as epilepsy. In particular, the possibility to specifically activate by light-determined interneuron populations expressing channelrhodopsin-2 provides an unprecedented opportunity of exploring their contribution to physiological and pathological network activity. There are several subclasses of interneurons in cortical areas with different functional connectivity to the principal neurons (e.g., targeting their perisomatic or dendritic compartments). Therefore, one could optogenetically activate specific or a mixed population of interneurons and dissect their selective or concerted inhibitory action on principal cells. We chose to explore a conceptually novel strategy involving simultaneous activation of mixed populations of interneurons by optogenetics and study their impact on ongoing epileptiform activity in mouse acute hippocampal slices. Here we demonstrate that such approach results in a brief initial action potential discharge in CA3 pyramidal neurons, followed by prolonged suppression of ongoing epileptiform activity during light exposure. Such sequence of events was caused by massive light-induced release of GABA from ChR2-expressing interneurons. The inhibition of epileptiform activity was less pronounced if only parvalbumin- or somatostatin-expressing interneurons were activated by light. Our data suggest that global optogenetic activation of mixed interneuron populations is a more effective approach for development of novel therapeutic strategies for epilepsy, but the initial action potential generation in principal neurons needs to be taken in consideration.

Activation of peroxisome proliferator-activated receptors (PPARs) by their ligands and protein kinase A activators

PubMed Central

Lazennec, Gwendal; Canaple, Laurence; Saugy, Damien; Wahli, Walter

2000-01-01

The nuclear peroxisome proliferator-activated receptors (PPARs) α, β and γ activate the transcription of multiple genes involved in lipid metabolism. Several natural and synthetic ligands have been identified for each PPAR isotype but little is known about the phosphorylation state of these receptors. We show here that activators of protein kinase A (PKA) can enhance mouse PPAR activity in the absence and the presence of exogenous ligands in transient transfection experiments. The activation function 1 (AF-1) of PPARs was dispensable for transcriptional enhancement, whereas the activation function 2 (AF-2) was required for this effect. We also show that several domains of PPAR can be phosphorylated by PKA in vitro. Moreover, gel experiments suggest that PKA stabilizes binding of the liganded PPAR to DNA. PKA inhibitors decreased not only the kinase dependent induction of PPARs but also their ligand-dependent induction, suggesting that the ligands may also mobilize the PKA pathway to lead to maximal transcriptional induction by PPARs. Moreover, comparing PPARα KO with PPARα wild-type mice, we show that the expression of the ACO gene can be regulated by PKA-activated PPARα in liver. These data demonstrate that the PKA pathway is an important modulator of PPAR activity and we propose a model associating this pathway in the control of fatty acid β-oxidation under conditions of fasting, stress and exercise. PMID:11117527

Simulation of natural gas production from submarine gas hydrate deposits combined with carbon dioxide storage

NASA Astrophysics Data System (ADS)

Janicki, Georg; Schlüter, Stefan; Hennig, Torsten; Deerberg, Görge

2013-04-01

potential from turbidites and their ability for carbon dioxide storage. The effects occurring during gas production and CO2 storage within a hydrate deposit are identified and described for various scenarios. The behaviour of relevant process parameters such as pressure, temperature and phase saturations is discussed and compared for different production strategies: depressurization, CO2 injection after depressurization and simultaneous methane production and CO2 injection.

In situ XRD Study of Ca2+ Saturated Montmorillonite (STX-1) Exposed to Anhydrous and Wet Supercritical Carbon Dioxide

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

Schaef, Herbert T.; Ilton, Eugene S.; Qafoku, Odeta

2012-01-09

Reactions involving scCO2 and a calcium saturated dioctahedral smectite (Ca-STX-1) were examined by in situ high-pressure x-ray diffraction over a range of temperatures (50° to 100°C) and pressures (90, 125, and 180 bar) relevant to long term geologic storage of CO2. Exposure of Ca-STX-1 containing one water of hydration (1W) to anhydrous scCO2 at 50°C and 90 bar produced an immediate increase of ~0.8 Å in the d001 basal reflection that was sustained for the length of the experiment (~44 hours). Higher ordered basal reflections displayed similar shifts. Following depressurization, positions of basal reflections and FWHM values (d001) returned tomore » initial values, with no measurable modification to the clay structure or water content. Similar results were obtained for tests conducted at 50°C and higher pressures (125 and 180 bar). Exposure of Ca-STX-1 containing two waters of hydration (2W) to scCO2 resulted in a decrease in the d001 reflection from 14.48 Å to 12.52 Å, after pressurization, indicating a partial loss of interlayer water. In addition, the hydration state of the clay became more homogeneous during contact with anhydrous scCO2 and after depressurization. In the presence of scCO2 and water, the clay achieved a 3W hydration state, based on a d001 spacing of 18.8 Å. In contrast to scCO2, comparable testing with N2 gas indicated trivial changes in the d001 series regardless of hydration state (1W or 2W). In the presence of free water and N2, the basal spacing for the Ca-STX-1 expanded slightly, but remained in the 2W hydration state. These experiments indicate that scCO2 can intercalate hydrated clays, where the 1W hydrate state is stable when exposed to anhydrous scCO2 under conditions proposed for geologic storage of CO2. Consequently, clays can act as secondary CO2 traps where potential collapse or expansion of the interlayer spacing depends on the initial hydration state of the clay and scCO2.« less

Heat Transfer by Thermo-capillary Convection -Sounding Rocket COMPERE Experiment SOURCE

NASA Astrophysics Data System (ADS)

Dreyer, Michael; Fuhrmann, Eckart

The sounding rocket COMPERE experiment SOURCE was successfully flown on MASER 11, launched in Kiruna (ESRANGE), May 15th, 2008. SOURCE has been intended to partly ful-fill the scientific objectives of the European Space Agency (ESA) Microgravity Applications Program (MAP) project AO-2004-111 (Convective boiling and condensation). Three parties of principle investigators have been involved to design the experiment set-up: ZARM for thermo-capillary flows, IMFT (Toulouse, France) for boiling studies, EADS Astrium (Bremen, Ger-many) for depressurization. The topic of this paper is to study the effect of wall heat flux on the contact line of the free liquid surface and to obtain a correlation for a convective heat trans-fer coefficient. The experiment has been conducted along a predefined time line. A preheating sequence at ground was the first operation to achieve a well defined temperature evolution within the test cell and its environment inside the rocket. Nearly one minute after launch, the pressurized test cell was filled with the test liquid HFE-7000 until a certain fill level was reached. Then the free surface could be observed for 120 s without distortion. Afterwards, the first depressurization was started to induce subcooled boiling, the second one to start saturated boiling. The data from the flight consists of video images and temperature measurements in the liquid, the solid, and the gaseous phase. Data analysis provides the surface shape versus time and the corresponding apparent contact angle. Computational analysis provides information for the determination of the heat transfer coefficient in a compensated gravity environment where a flow is caused by the temperature difference between the hot wall and the cold liquid. The paper will deliver correlations for the effective contact angle and the heat transfer coefficient as a function of the relevant dimensionsless parameters as well as physical explanations for the observed behavior. The data will be used

Calibration and validation of a numerical model against experimental data of methane hydrate formation and dissociation in a sandy porous medium

NASA Astrophysics Data System (ADS)

Yin, Z.; Moridis, G. J.; Chong, Z. R.; Linga, P.

2017-12-01

Methane hydrates (MH) are known to trap enormous amounts of CH4 in oceanic and permafrost-associated deposits, and are being considered as a potential future energy source. Several powerful numerical simulators were developed to describe the behavior of natural hydrate-bearing sediments (HBS). The complexity and strong nonlinearities in HBS do not allow analytical solutions for code validation. The only reliable method to develop confidence in these models is through comparisons to laboratory and/or field experiments. The objective of this study is to reproduce numerically the results from earlier experiments of MH formation and depressurization (and the corresponding fluid production) in 1.0L reactor involving unconsolidated sand, thus validating and calibrating the TOUGH+Hydrate v1.5 simulator. We faithfully describe the reactor geometry and the experimental process that involves both hydrate formation and dissociation. We demonstrate that the laboratory experiments can only be captured by a kinetic hydration model. There is an excellent agreement between observations and predictions (a) of the cumulative gas depletion (during formation) and production (during dissociation) and (b) of pressure over time. The temperature agreement is less satisfactory, and the deviations are attributed to the fixed locations of the limited number of sensors that cannot fully capture the hydrate heterogeneity. We also predict the spatial distributions over time of the various phase (gas, aqueous and hydrate) saturations. Thus, hydrates form preferentially along the outer boundary of the sand core, and the hydrate front moves inward leaving a significant portion of the sand at the center hydrate-free. During depressurization, dissociation advances again inward from the reactor boundary to the center of the reactor. As expected, methane gas accumulates initially at the locations of most intense dissociation, and then gradually migrates to the upper section of the reactor because of

Parental Activity as a Determinant of Activity Level and Patterns of Activity in Obese Children.

ERIC Educational Resources Information Center

Kalakanis, Lisa E.; Goldfield, Gary S.; Paluch, Rocco A.; Epstein, Leonard H.

2001-01-01

Investigated the level and pattern of moderate-to-vigorous physical activity (MVPA) in obese children, examining predictors of their activity. Children and their parents wore accelerometers for several days and provided demographic data. Parental activity levels significantly and independently predicted and improved the prediction of children's…

Impact of Activity Behaviors on Physical Activity Identity and Self-Efficacy.

ERIC Educational Resources Information Center

Miller, Kim H.; Ogletree, Robert J.; Welshimer, Kathleen

2002-01-01

Examined the relationship of physical activity level and length of time of adherence to physical activity with physical activity identity (PAI) and physical activity self-efficacy (PASE). Surveys of 409 adult university employees indicated that vigorous activity related to higher PAI and PASE scores, and activity level contributed significantly…

In vivo imaging of protease activity by Probody therapeutic activation

PubMed Central

Wong, Kenneth R.; Menendez, Elizabeth; Craik, Charles S.; Kavanaugh, W. Michael; Vasiljeva, Olga

2017-01-01

Probody™ therapeutics are recombinant, proteolytically-activated antibody prodrugs, engineered to remain inert until activated locally by tumor-associated proteases. Probody therapeutics exploit the fundamental dysregulation of extracellular protease activity that exists in tumors relative to healthy tissue. Leveraging the ability of a Probody therapeutic to bind its target at the site of disease after proteolytic cleavage, we developed a novel method for profiling protease activity in living animals. Using NIR optical imaging, we demonstrated that a non-labeled anti-EGFR Probody therapeutic can become activated and compete for binding to tumor cells in vivo with a labeled anti-EGFR monoclonal antibody. Furthermore, by inhibiting matriptase activity in vivo with a blocking-matriptase antibody, we show that the ability of the Probody therapeutic to bind EGFR in vivo was dependent on protease activity. These results demonstrate that in vivo imaging of Probody therapeutic activation can be used for screening and characterization of protease activity in living animals, and provide a method that avoids some of the limitations of prior methods. This approach can improve our understanding of the activity of proteases in disease models and help to develop efficient strategies for cancer diagnosis and treatment. PMID:26546838

Physical Activity and Health: The Benefits of Physical Activity

MedlinePlus

... State and Local Programs Related Topics Diabetes Nutrition Physical Activity and Health Recommend on Facebook Tweet Share Compartir ... Your Chances of Living Longer The Benefits of Physical Activity Regular physical activity is one of the most ...

Assessing physical activity using wearable monitors: measures of physical activity.

PubMed

Butte, Nancy F; Ekelund, Ulf; Westerterp, Klaas R

2012-01-01

Physical activity may be defined broadly as "all bodily actions produced by the contraction of skeletal muscle that increase energy expenditure above basal level." Physical activity is a complex construct that can be classified into major categories qualitatively, quantitatively, or contextually. The quantitative assessment of physical activity using wearable monitors is grounded in the measurement of energy expenditure. Six main categories of wearable monitors are currently available to investigators: pedometers, load transducers/foot-contact monitors, accelerometers, HR monitors, combined accelerometer and HR monitors, and multiple sensor systems. Currently available monitors are capable of measuring total physical activity as well as components of physical activity that play important roles in human health. The selection of wearable monitors for measuring physical activity will depend on the physical activity component of interest, study objectives, characteristics of the target population, and study feasibility in terms of cost and logistics. Future development of sensors and analytical techniques for assessing physical activity should focus on the dynamic ranges of sensors, comparability for sensor output across manufacturers, and the application of advanced modeling techniques to predict energy expenditure and classify physical activities. New approaches for qualitatively classifying physical activity should be validated using direct observation or recording. New sensors and methods for quantitatively assessing physical activity should be validated in laboratory and free-living populations using criterion methods of calorimetry or doubly labeled water.

Is a Perceived Activity-Friendly Environment Associated with More Physical Activity and Fewer Screen-Based Activities in Adolescents?

PubMed

Kopcakova, Jaroslava; Dankulincova Veselska, Zuzana; Madarasova Geckova, Andrea; Bucksch, Jens; Nalecz, Hanna; Sigmundova, Dagmar; van Dijk, Jitse P; Reijneveld, Sijmen A

2017-01-03

Background: The aim of this study is to explore if perception of an activity-friendly environment is associated with more physical activity and fewer screen-based activities among adolescents. Methods: We collected self-reported data in 2014 via the Health Behavior in School-aged Children cross-sectional study from four European countries ( n = 13,800, mean age = 14.4, 49.4% boys). We explored the association of perceived environment (e.g., "There are other children nearby home to go out and play with") with physical activity and screen-based activities using a binary logistic regression model adjusted for age, gender, family affluence and country. Results: An environment perceived as activity-friendly was associated with higher odds that adolescents meet recommendations for physical activity (odds ratio (OR) for one standard deviation (SD) change = 1.11, 95% confidence interval (CI) 1.05-1.18) and lower odds for excessive screen-based activities (OR for 1 SD better = 0.93, 95% CI 0.88-0.98). Conclusions: Investment into an activity-friendly environment may support the promotion of active life styles in adolescence.

Research of working pulsation in closed angle based on rotating-sleeve distributing-flow system

NASA Astrophysics Data System (ADS)

Zhang, Yanjun; Zhang, Hongxin; Zhao, Qinghai; Jiang, Xiaotian; Cheng, Qianchang

2017-08-01

In order to reduce negative effects including hydraulic impact, noise and mechanical vibration, compression and expansion of piston pump in closed volume are used to optimize the angle between valve port and chamber. In addition, the mathematical model about pressurization and depressurization in pump chamber are analyzed based on distributing-flow characteristic, and it is necessary to use simulation software Fluent to simulate the distributing-flow fluid model so as to select the most suitable closed angle. As a result, when compression angle is 3°, the angle is closest to theoretical analysis and has the minimum influence on flow and pump pressure characteristic. Meanwhile, cavitation phenomenon appears in pump chamber in different closed angle on different degrees. Besides the flow pulsation is increasingly smaller with increasing expansion angle. Thus when expansion angle is 2°, the angle is more suitable for distributing-flow system.

Secondary migration and leakage of methane from a major tight-gas system

NASA Astrophysics Data System (ADS)

Wood, James M.; Sanei, Hamed

2016-11-01

Tight-gas and shale-gas systems can undergo significant depressurization during basin uplift and erosion of overburden due primarily to the natural leakage of hydrocarbon fluids. To date, geologic factors governing hydrocarbon leakage from such systems are poorly documented and understood. Here we show, in a study of produced natural gas from 1,907 petroleum wells drilled into a Triassic tight-gas system in western Canada, that hydrocarbon fluid loss is focused along distinct curvilinear pathways controlled by stratigraphic trends with superior matrix permeability and likely also structural trends with enhanced fracture permeability. Natural gas along these pathways is preferentially enriched in methane because of selective secondary migration and phase separation processes. The leakage and secondary migration of thermogenic methane to surficial strata is part of an ongoing carbon cycle in which organic carbon in the deep sedimentary basin transforms into methane, and ultimately reaches the near-surface groundwater and atmosphere.

Emergency egress requirements for Space Station Freedom

NASA Technical Reports Server (NTRS)

Ray, Paul S.

1990-01-01

There is a real concern regarding the requirements for safe emergency egress from the Space Station Freedom (SSF). The possible causes of emergency are depressurization due to breach of the station hull by space debris, meteoroids, seal failure, or vent failure; chemical toxicity; and a large fire. The objectives of the current study are to identify the tasks required to be performed in emergencies, establish the time required to perform these tasks, and to review the human equipment interface in emergencies. It was found that a fixed time value specified for egress has shifted focus from the basic requirements of safe egress, that in some situations the crew members may not be able to complete the emergency egress tasks in three minutes without sacrificing more than half of the station, and that increased focus should be given to human factors aspects of space station design.

Oxygen Generation Assembly Technology Development

NASA Technical Reports Server (NTRS)

Bagdigian, Robert; Cloud, Dale

1999-01-01

Hamilton Standard Space Systems International (HSSI) is under contract to NASA Marshall Space Flight Center (MSFC) to develop an Oxygen Generation Assembly (OGA) for the International Space Station (ISS). The International Space Station Oxygen Generation Assembly (OGA) electrolyzes potable water from the Water Recovery System (WRS) to provide gaseous oxygen to the Space Station module atmosphere. The OGA produces oxygen for metabolic consumption by crew and biological specimens. The OGA also replenishes oxygen lost by experiment ingestion, airlock depressurization, CO2 venting, and leakage. As a byproduct, gaseous hydrogen is generated. The hydrogen will be supplied at a specified pressure range above ambient to support future utilization. Initially, the hydrogen will be vented overboard to space vacuum. This paper describes the OGA integration into the ISS Node 3. It details the development history supporting the design and describes the OGA System characteristics and its physical layout.

Aneurysm Shrinkage Is Compatible With Massive Endoleak in the Presence of an Aortocaval Fistula: Potential Therapeutic Implications for Endoleaks and Spinal Cord Ischemia.

PubMed

Sveinsson, Magnus; Sonesson, Björn; Resch, Timothy A; Dias, Nuno V; Holst, Jan; Malina, Martin

2016-06-01

To present a patient with ruptured abdominal aortic aneurysm (AAA) and aortocaval fistula who was successfully treated with endovascular aneurysm repair in spite of developing a massive endoleak. A 70-year-old man with ruptured AAA and aortocaval fistula was treated with endovascular aneurysm repair (EVAR). During 8 years of follow-up, he had massive perfusion of the aneurysm sac by retrograde flow from the inferior mesenteric artery into the caval vein through the aortocaval fistula. The aneurysm diameter decreased continuously in spite of the type II endoleak. This observation illustrates the mechanisms of sac expansion and may have therapeutic implications for complicated type II endoleaks and prevention of spinal cord ischemia in thoracic stent-grafting. EVAR can be applied in this rare setting because the ensuing high-flow endoleak is associated with sac shrinkage owing to depressurization by the caval shunt. © The Author(s) 2016.

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

Wagner, J.; Sullivan, D.P.; Faulkner, D.

The purpose of this study is to quantify the effect ofvarious design and operating parameters on smoking room performance.Twenty-eight experiments were conducted in a simulated smoking room witha smoking machine and an automatic door opener. Measurements were made ofair flows, pressures, temperatures, two particle-phase ETS tracers, twogas-phase ETS tracers, and sulfur hexafluoride. Quantification of leakageflows, the effect of these leaks on smoking room performance andnon-smoker exposure, and the relative importance of each leakagemechanism are presented. The results indicate that the first priority foran effective smoking room is to depressurize it with respect to adjoiningnon-smoking areas. Another important ETS leakage mechanismmore » is the pumpingaction of the smoking room door. Substituting a sliding door for astandard swing-type door reduced this source of ETS leakagesignificantly. Measured results correlated well with model predictions(R2 = 0.82-0.99).« less

Triggering and dynamic evolution of the LUSI mud volcano, Indonesia

NASA Astrophysics Data System (ADS)

Mazzini, A.; Svensen, H.; Akhmanov, G. G.; Aloisi, G.; Planke, S.; Malthe-Sørenssen, A.; Istadi, B.

2007-09-01

Mud volcanoes are geologically important manifestations of vertical fluid flow and mud eruption in sedimentary basins worldwide. Their formation is predominantly ascribed to release of overpressure from clay- and organic-rich sediments, leading to impressive build-up of mud mountains in submarine and subaerial settings. Here we report on a newly born mud volcano appearing close to an active magmatic complex in a backarc sedimentary basin in Indonesia. The location of the mud volcano close to magmatic volcanoes results in a high background temperature gradient that triggers mineralogical transformations and geochemical reactions at shallow depth. The eruption of 100 °C mud and gas that started the 29th of May 2006 flooded a large area within the Sidoarjo village in Northeast Java. Thousands of people have so far been evacuated due to the mud flood hazards from the eruption. Since the initial eruption, the flow rate escalated from 5000 to 120,000 m 3/d during the first eleven weeks. Then the erupted volume started to pulsate between almost zero and 120,000 m 3/d in the period August 14 to September 10, whereas it increased dramatically following swarms of earthquakes in September, before reaching almost 180,000 m 3/d in December 2006. Sampling and observations were completed during two fieldwork campaigns on the site. The eruption of boiling water is accompanied by mud, aqueous vapour, CO 2 and CH 4. Based on geochemical and field results, we propose a mechanism where the eruptions started following the 27th of May earthquake due to fracturing and accompanied depressurization of > 100 °C pore fluids from > 1700 m depth. This resulted in the formation of a quasi-hydrothermal system with a geyser-like surface expression and with an activity influenced by the regional seismicity.

Triggering and dynamic evolution of the LUSI mud volcano, Indonesia

NASA Astrophysics Data System (ADS)

Svensen, H.; Mazzini, A.; Akhmanov, G. G.; Aloisi, G.; Planke, S.; Sørenssen, A.; Istadi, B.

2007-12-01

Mud volcanoes are geologically important manifestations of vertical fluid flow and mud eruption in sedimentary basins worldwide. Their formation is predominantly ascribed to release of overpressure from clay- and organic- rich sediments, leading to impressive buildup of mud mountains in submarine and subaerial settings. Here we report data from two fieldworks on a newly born mud volcano named LUSI eruption in Eastern Java (Indonesia). The eruption site appears close to an active magmatic complex in a backarc sedimentary basin in Indonesia. Its specific location results in a high background temperature gradient that triggers mineralogical transformations and geochemical reactions at shallow depth. The eruption of 100 deg.C mud and gas that started the 29th of May 2006 flooded a large area within the Sidoarjo village in Northeast Java. Thousands of people have so far been evacuated and, since the initial eruption, the flow rate escalated from 5000 to 120,000 m3/d during the first eleven weeks. Then the erupted volume started to pulsate between almost zero and 120,000 m3/d in the period August-September, whereas it increased dramatically following swarms of earthquakes in September, before reaching almost 180,000 m3/d in December 2006. Fifteen months after the initial burst, LUSI is still vigorously erupting up to 111,000 m3/d, the average subsidence of the area reached 11 m. Seismic images show that a pre-existing structure was present before the eruption. Based on geochemical and field results, we propose a mechanism where the eruptions started following the 27th of May earthquake due to fracturing and accompanied depressurization of >100 deg.C pore fluids from > 1700 m depth released from a structure in already critical conditions. This resulted in the formation of a quasi-hydrothermal system with a geyser-like surface expression and with an activity influenced by the regional seismicity.

Pulmonary Toxicity Studies of Lunar Dusts in Rodents

NASA Technical Reports Server (NTRS)

Lam, C.-W.; James, J. T.; Taylor, L.; Zeidler-Erdely, P. C.; Castranova, V.

2009-01-01

NASA will build an outpost on the Moon for prolonged human habitation and research. The lunar surface is covered by a layer of fine, reactive dust. Astronauts on the Moon will go in and out of the base for various activities, and will inevitably bring some dust into the living quarters. Depressurizing the airlock so that astronauts can exit for outdoor activities could also bring dust inside the airlock to the habitable area. Concerned about the potential health effects on astronauts exposed to airborne lunar dust, NASA directed the JSC Toxicology Laboratory to determine the pulmonary toxicity of lunar dust. The toxicity data also will be needed by toxicologists to establish safe exposure limits for astronauts residing in the lunar habitat and by environmental engineers to design an appropriate dust mitigation strategy. We conducted a study to examine biomarkers of toxicity (inflammation and cytotoxicity) in lung lavage fluids from mice intrapharyngeally instilled with lunar dust samples; we also collected lung tissue from the mice for histopathological examination 3 months after the dust instillation. Reference dusts (TiO2 and quartz) having known toxicities and industrial exposure limits were studied in parallel with lunar dust so that the relative toxicity of lunar dust can be determined. A 6-month histopathology study has been planned. These instillation experiments will be followed by inhalation studies, which are more labor intensive and technologically difficult. The animal inhalation studies will be conducted first with an appropriate lunar dust simulant to ensure that the exposure techniques to be used with actual lunar dust will be successful. The results of these studies collectively will reveal the toxicological risk of exposures and enable us to establish exposure limits on lunar dust for astronauts living in the lunar habitat.

Probabilistic short-term forecasting of eruption rate at Kīlauea Volcano using a physics-based model

NASA Astrophysics Data System (ADS)

Anderson, K. R.

2016-12-01

Deterministic models of volcanic eruptions yield predictions of future activity conditioned on uncertainty in the current state of the system. Physics-based eruption models are well-suited for deterministic forecasting as they can relate magma physics with a wide range of observations. Yet, physics-based eruption forecasting is strongly limited by an inadequate understanding of volcanic systems, and the need for eruption models to be computationally tractable. At Kīlauea Volcano, Hawaii, episodic depressurization-pressurization cycles of the magma system generate correlated, quasi-exponential variations in ground deformation and surface height of the active summit lava lake. Deflations are associated with reductions in eruption rate, or even brief eruptive pauses, and thus partly control lava flow advance rates and associated hazard. Because of the relatively well-understood nature of Kīlauea's shallow magma plumbing system, and because more than 600 of these events have been recorded to date, they offer a unique opportunity to refine a physics-based effusive eruption forecasting approach and apply it to lava eruption rates over short (hours to days) time periods. A simple physical model of the volcano ascribes observed data to temporary reductions in magma supply to an elastic reservoir filled with compressible magma. This model can be used to predict the evolution of an ongoing event, but because the mechanism that triggers events is unknown, event durations are modeled stochastically from previous observations. A Bayesian approach incorporates diverse data sets and prior information to simultaneously estimate uncertain model parameters and future states of the system. Forecasts take the form of probability distributions for eruption rate or cumulative erupted volume at some future time. Results demonstrate the significant uncertainties that still remain even for short-term eruption forecasting at a well-monitored volcano - but also the value of a physics

Antioxidant activity of taxifolin: an activity-structure relationship.

PubMed

Topal, Fevzi; Nar, Meryem; Gocer, Hulya; Kalin, Pınar; Kocyigit, Umit M; Gülçin, İlhami; Alwasel, Saleh H

2016-08-01

Taxifolin is a kind of flavanonol, whose biological ability. The objectives of this study were to investigate the antioxidants and antiradical activities of taxifolin by using different in vitro bioanalytical antioxidant methods including DMPD√(+), ABTS√(+), [Formula: see text], and DPPH√-scavenging effects, the total antioxidant influence, reducing capabilities, and Fe(2+)-chelating activities. Taxifolin demonstrated 81.02% inhibition of linoleic acid emulsion peroxidation at 30 µg/mL concentration. At the same concentration, standard antioxidants including trolox, α-tocopherol, BHT, and BHA exhibited inhibitions of linoleic acid emulsion as 88.57, 73.88, 94.29, and 90.12%, respectively. Also, taxifolin exhibited effective DMPD√(+), ABTS√(+), [Formula: see text], and DPPH√-scavenging effects, reducing capabilities, and Fe(2+)-chelating effects. The results obtained from this study clearly showed that taxifolin had marked antioxidant, reducing ability, radical scavenging and metal-chelating activities. Also, this study exhibits a scientific shore for the significant antioxidant activity of taxifolin and its structure-activity insight.

Dutch children and parents' views on active and non-active video gaming.

PubMed

De Vet, Emely; Simons, Monique; Wesselman, Maarten

2014-06-01

Active video games that require whole body movement to play the game may be an innovative health promotion tool to substitute sedentary pastime with more active time and may therefore contribute to children's health. To inform strategies aimed at reducing sedentary behavior by replacing non-active by active gaming, opinions about active and non-active video games are explored among 8- to 12-year-old children and their parents. Six qualitative, semi-structured focus groups were held with 8- to 12-year-old children (n = 46) and four with their parents (n = 19) at three different primary schools in The Netherlands. The focus groups with children discussed game preferences, gaming context and perceived game-related parenting. The focus groups with parents addressed considerations in purchasing video games, perceived positive and negative consequences of gaming, and game-related parenting. Both children and their parents were very positive about active video games and preferred active games over non-active games. Active video games were considered more social than non-active video games, and active games were played more often together with friends and family than non-active video games. Parenting practices did not differ for active and non-active video games, although some parents were less strict regarding active games. Two conditions for practical implementation were met: children enjoyed active video games, and parents were willing to buy active video games. Active video games were preferred to non-active video games, illustrating that using active video games is a promising health promotion tool to reduce sedentary pastime in youth.

Active Brownian particles with velocity-alignment and active fluctuations

NASA Astrophysics Data System (ADS)

Großmann, R.; Schimansky-Geier, L.; Romanczuk, P.

2012-07-01

We consider a model of active Brownian particles (ABPs) with velocity alignment in two spatial dimensions with passive and active fluctuations. Here, active fluctuations refers to purely non-equilibrium stochastic forces correlated with the heading of an individual active particle. In the simplest case studied here, they are assumed to be independent stochastic forces parallel (speed noise) and perpendicular (angular noise) to the velocity of the particle. On the other hand, passive fluctuations are defined by a noise vector independent of the direction of motion of a particle, and may account, for example, for thermal fluctuations. We derive a macroscopic description of the ABP gas with velocity-alignment interaction. Here, we start from the individual-based description in terms of stochastic differential equations (Langevin equations) and derive equations of motion for the coarse-grained kinetic variables (density, velocity and temperature) via a moment expansion of the corresponding probability density function. We focus here on the different impact of active and passive fluctuations on onset of collective motion and show how active fluctuations in the active Brownian dynamics can change the phase-transition behaviour of the system. In particular, we show that active angular fluctuations lead to an earlier breakdown of collective motion and to the emergence of a new bistable regime in the mean-field case.

29 CFR 779.208 - Auxiliary activities which are “related activities.”

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 3 2010-07-01 2010-07-01 false Auxiliary activities which are ârelated activities.â 779...; Enterprise Coverage Related Activities § 779.208 Auxiliary activities which are “related activities.” As... activities, such as central office and warehousing activities and bookkeeping, auditing, purchasing...

Weekday and weekend sedentary time and physical activity in differentially active children.

PubMed

Fairclough, Stuart J; Boddy, Lynne M; Mackintosh, Kelly A; Valencia-Peris, Alexandra; Ramirez-Rico, Elena

2015-07-01

To investigate whether weekday-weekend differences in sedentary time and specific intensities of physical activity exist among children categorised by physical activity levels. Cross-sectional observational study. Seven-day accelerometer data were obtained from 810 English children (n=420 girls) aged 10-11 years. Daily average minday(-1) spent in moderate to vigorous physical activity were calculated for each child. Sex-specific moderate to vigorous physical activity quartile cut-off values categorised boys and girls separately into four graded groups representing the least (Q1) through to the most active (Q4) children. Sex- and activity quartile-specific multilevel linear regression analyses analysed differences in sedentary time, light physical activity, moderate physical activity, vigorous physical activity, and moderate to vigorous physical activity between weekdays and weekends. On weekdays Q2 boys spent longer in light physical activity (p<0.05), Q1 (p<0.001), Q2 boys (p<0.01) did significantly more moderate physical activity, and Q1-Q3 boys accumulated significantly more vigorous physical activity and moderate to vigorous physical activity than at weekends. There were no significant differences in weekday and weekend sedentary time or physical activity for Q4 boys. On weekdays Q2 and Q3 girls accumulated more sedentary time (p<0.05), Q1 and Q2 girls did significantly more moderate physical activity (p<0.05), and Q1-Q3 girls engaged in more vigorous physical activity (p<0.05) and more moderate to vigorous physical activity (p<0.01) than at weekends. Q4 girls' sedentary time and physical activity varied little between weekdays and weekends. The most active children maintained their sedentary time and physical activity levels at weekends, while among less active peers weekend sedentary time and physical activity at all intensities was lower. Low active children may benefit most from weekend intervention strategies. Copyright © 2014 Sports Medicine Australia

Comparison of the performance of the activPAL Professional physical activity logger to a discrete accelerometer-based activity monitor.

PubMed

Godfrey, A; Culhane, K M; Lyons, G M

2007-10-01

The aim of this study was to assess the accuracy of the 'activPAL Professional' physical activity logger by comparing its output to that of a proven discrete accelerometer-based activity monitor during extended measurements on healthy subjects while performing activities of daily living (ADL). Ten healthy adults, with unrestricted mobility, wore both the activPAL and the discrete dual accelerometer (Analog Devices ADXL202)-based activity monitor that recorded in synchronization with each other. The accelerometer derived data were then compared to that generated by the activPAL and a complete statistical and error analysis was performed using a Matlab program. This program determined trunk and thigh inclination angles to distinguish between sitting/lying, standing and stepping for the discrete accelerometer device and amount of time spent on each activity. Analysis was performed on a second-by-second basis and then categorized at 15s intervals in direct comparison with the activPAL generated data. Of the total time monitored (approximately 60 h) the detection accuracies for static and dynamic activities were approximately 98%. In a population of healthy adults, the data obtained from the activPAL Professional physical activity logger for both static and dynamic activities showed a close match to a proven discrete accelerometer data with an offset of approximately 2% between the two systems.

Integration of Active Video Games in Extracurricular Activity at Schools

ERIC Educational Resources Information Center

Lee, Jung Eun; Huang, Charles; Pope, Zachary; Gao, Zan

2015-01-01

Active video games require players to be physically active. Dance Dance Revolution (DDR) is an interactive dancing game that requires fast-foot movement coordinated with energetic music and visuals. The Wii and Xbox Kinect games have also become good active video games for the promotion of physical activity participation. These games are much more…

Retro-binding thrombin active site inhibitors: identification of an orally active inhibitor of thrombin catalytic activity.

PubMed

Iwanowicz, Edwin J; Kimball, S David; Lin, James; Lau, Wan; Han, W-C; Wang, Tammy C; Roberts, Daniel G M; Schumacher, W A; Ogletree, Martin L; Seiler, Steven M

2002-11-04

A series of retro-binding inhibitors of human alpha-thrombin was prepared to elucidate structure-activity relationships (SAR) and optimize in vivo performance. Compounds 9 and 11, orally active inhibitors of thrombin catalytic activity, were identified to be efficacious in a thrombin-induced lethality model in mice.

Unconventional Oil and Gas Resources in Texas and Other Mining Activities: the Water Challenge

NASA Astrophysics Data System (ADS)

Nicot, J.

2011-12-01

A recent study, sponsored by the Texas Water Development Board, considered current and projected water use in the mining industry. It looked at the upstream segment of the oil and gas industry (that is, water used to extract the commodity until it leaves the wellhead), the aggregate, and coal industry, and other substances (industrial sand, lime, etc.). We obtained data through state databases, data collection from private vendors, and direct surveys of the various sectors of the industry. Overall, in 2008, we estimated that the state consumed ~160 thousand acre-feet (AF) in the mining industry, including 35.8 thousand AF for fracing wells (mostly in the Barnett Shale/Fort Worth area) and ~21.0 thousand AF for other purposes in the oil and gas industry, although more spread out across the state, with a higher demand in the Permian Basin area in West Texas. The coal industry used 20.0 thousand AF along the lignite belt from Central to East Texas. The 71.6 thousand AF used by the aggregate industry is distributed over most of the state, but with a clear concentration around major metropolitan areas. The remainder amounts to 11.0 thousand AF and is dominated by industrial sand production (~80% of total). Water is used mostly for drilling wells, stimulating/fracing wells, and secondary and tertiary recovery processes (oil and gas industry); for dewatering and depressurizing pits, with a small amount used for dust control (coal industry); and for dust control and washing (aggregate industry and industrial sand). Reuse/recycling has already been accounted for in water-use values, as well as opportunity usages, such as stormwater collection (aggregates). The split between surface water and groundwater is difficult to assess but it is estimated at ~56% groundwater in 2008. Projections for future use were done by extrapolating current trends, mainly for coal (same energy mix) and aggregates (following population growth). Projections for the oil and gas industry (Barnett

Mutagenic activation reduces carcinogenic activity of ortho-aminoazotoluene for mouse liver.

PubMed

Ovchinnikova, L P; Bogdanova, L A; Kaledin, V I

2013-03-01

Pentachlorophenol (aromatic amine and azo stain metabolic stimulation inhibitor) reduced the hepatocarcinogenic activity of 4-aminoazobenzene and reduced that of ortho-aminoazotoluene in suckling mice. Both 4-aminoazobenzene and ortho-aminoazotoluene exhibited mutagenic activity in Ames' test in vitro on S. typhimurium TA 98 strain with activation with liver enzymes; this mutagenic activity was similarly suppressed by adding pentachlorophenol into activation medium. Induction of xenobiotic metabolism enzymes, stimulating the mutagenic activity of ortho-aminoazotoluene, suppressed its carcinogenic effect on mouse liver. Hence, ortho-aminotoluene (the initial compound), but not its mutagenic metabolites, was the direct active hepatocarcinogen for mice.

Assessing adult leisure activities: an extension of a self-report activity questionnaire.

PubMed

Jopp, Daniela S; Hertzog, Christopher

2010-03-01

Everyday leisure activities in adulthood and old age have been investigated with respect to constructs such as successful aging, an engaged lifestyle, and prevention of age-related cognitive decline. They also relate to mental health and have clinical value, as they can inform diagnosis and interventions. In the present study, the authors enhanced the content validity of the Victoria Longitudinal Study activity questionnaire by adding items on physical and social activities and validated a shortened version of the questionnaire. The proposed leisure activity model included 11 activity categories: 3 types of social activities (i.e., activities with close social partners, group-centered public activity, religious activities), physical activities, developmental activities, experiential activities, crafts, game playing, TV watching, travel, and technology use. Confirmatory factor analyses validated the proposed factor structure in 2 independent samples. A higher order model with a general activity factor fitted the activity factor correlations with relatively little loss of fit. Convergent and discriminant validity for the activity scales were supported by patterns of their correlations with education, health, depression, cognition, and personality. In sum, the scores derived from of the augmented Victoria Longitudinal Study activity questionnaire demonstrate good reliability, and validity evidence supports their use as measures of leisure activities in young, middle-aged, and older individuals. PsycINFO Database Record (c) 2010 APA, all rights reserved.

Physical Activity Guidelines

MedlinePlus

... use this site. health.gov Physical Activity Guidelines Physical Activity Physical activity is key to improving the health of the Nation. Based on the latest science, the Physical Activity Guidelines for Americans is an essential resource for ...

Elevation of oleate-activated phospholipase D activity during thymic atrophy

PubMed Central

Lee, Youngkyun; Song, Soo-Mee; Park, Heung Soon; Kim, Sungyeol; Koh, Eun-Hee; Choi, Myung Sun; Choi, Myung-Un

2002-01-01

Various phospholipases are thought to be associated with the in vitro apoptosis of thymocytes. In the present study, the in vivo phospholipase D (PLD) activity of rat thymus was studied after whole-body X-irradiation or injection of dexamethasone (DEX). Using exogenous [14C]dipalmitoyl phosphatidylcholine (PC) as the substrate, an elevation of oleate-activated PLD activity was observed during thymic atrophy. The activity increases were sevenfold at 48 hr after 5-Gy irradiation and fourfold at 72 hr after injection of 5 mg/kg DEX. The elevation of PLD activity appeared to parallel extensive thymus shrinkage. An increased level of thymic phosphatidic acid (PA), the presumed physiological product of PLD action on PC, was also detected. By comparing the acyl chains of PA with those of other phospholipids, PA appeared to originate from PC. To assess the role of PLD during thymic atrophy, thymocytes and stromal cells were isolated. Although thymocytes themselves exhibited significant PLD activation, the major elevation in PLD activity (greater than fourfold) was found in isolated stromal cells. PLD was also activated during in vitro phagocytosis of apoptotic thymocytes by the macrophage-like cell line P388D1. This in vitro phagocytosis was significantly inhibited by PLD action blockers, such as 2,3-diphosphoglycerate and 1-butanol. These observations strongly suggest that the alteration of oleate-activated PLD activity is part of an in vivo event in the progression of thymic atrophy, including phagocytic clearance of apoptotic thymocytes. PMID:12460188

Active nematic emulsions

PubMed Central

Hardoüin, Jérôme; Sagués, Francesc

2018-01-01

The formation of emulsions from multiple immiscible fluids is governed by classical concepts such as surface tension, differential chemical affinity and viscosity, and the action of surface-active agents. Much less is known about emulsification when one of the components is active and thus inherently not constrained by the laws of thermodynamic equilibrium. We demonstrate one such realization consisting in the encapsulation of an active liquid crystal (LC)–like gel, based on microtubules and kinesin molecular motors, into a thermotropic LC. These active nematic emulsions exhibit a variety of dynamic behaviors that arise from the cross-talk between topological defects separately residing in the active and passive components. Using numerical simulations, we show a feedback mechanism by which active flows continuously drive the passive defects that, in response, resolve the otherwise degenerated trajectories of the active defects. Our experiments show that the choice of surfactant, which stabilizes the active/passive interface, allows tuning the regularity of the self-sustained dynamic events. The hybrid active-passive system demonstrated here provides new perspectives for dynamic self-assembly driven by an active material but regulated by the equilibrium properties of the passive component. PMID:29740605

Active nematic emulsions.

PubMed

Guillamat, Pau; Kos, Žiga; Hardoüin, Jérôme; Ignés-Mullol, Jordi; Ravnik, Miha; Sagués, Francesc

2018-04-01

The formation of emulsions from multiple immiscible fluids is governed by classical concepts such as surface tension, differential chemical affinity and viscosity, and the action of surface-active agents. Much less is known about emulsification when one of the components is active and thus inherently not constrained by the laws of thermodynamic equilibrium. We demonstrate one such realization consisting in the encapsulation of an active liquid crystal (LC)-like gel, based on microtubules and kinesin molecular motors, into a thermotropic LC. These active nematic emulsions exhibit a variety of dynamic behaviors that arise from the cross-talk between topological defects separately residing in the active and passive components. Using numerical simulations, we show a feedback mechanism by which active flows continuously drive the passive defects that, in response, resolve the otherwise degenerated trajectories of the active defects. Our experiments show that the choice of surfactant, which stabilizes the active/passive interface, allows tuning the regularity of the self-sustained dynamic events. The hybrid active-passive system demonstrated here provides new perspectives for dynamic self-assembly driven by an active material but regulated by the equilibrium properties of the passive component.

A Youth Compendium of Physical Activities: Activity Codes and Metabolic Intensities

PubMed Central

BUTTE, NANCY F.; WATSON, KATHLEEN B.; RIDLEY, KATE; ZAKERI, ISSA F.; MCMURRAY, ROBERT G.; PFEIFFER, KARIN A.; CROUTER, SCOTT E.; HERRMANN, STEPHEN D.; BASSETT, DAVID R.; LONG, ALEXANDER; BERHANE, ZEKARIAS; TROST, STEWART G.; AINSWORTH, BARBARA E.; BERRIGAN, DAVID; FULTON, JANET E.

2018-01-01

ABSTRACT Purpose A Youth Compendium of Physical Activities (Youth Compendium) was developed to estimate the energy costs of physical activities using data on youth only. Methods On the basis of a literature search and pooled data of energy expenditure measurements in youth, the energy costs of 196 activities were compiled in 16 activity categories to form a Youth Compendium of Physical Activities. To estimate the intensity of each activity, measured oxygen consumption (V˙O2) was divided by basal metabolic rate (Schofield age-, sex-, and mass-specific equations) to produce a youth MET (METy). A mixed linear model was developed for each activity category to impute missing values for age ranges with no observations for a specific activity. Results This Youth Compendium consists of METy values for 196 specific activities classified into 16 major categories for four age-groups, 6–9, 10–12, 13–15, and 16–18 yr. METy values in this Youth Compendium were measured (51%) or imputed (49%) from youth data. Conclusion This Youth Compendium of Physical Activities uses pediatric data exclusively, addresses the age dependency of METy, and imputes missing METy values and thus represents advancement in physical activity research and practice. This Youth Compendium will be a valuable resource for stakeholders interested in evaluating interventions, programs, and policies designed to assess and encourage physical activity in youth. PMID:28938248

Vestibular activation of sympathetic nerve activity

NASA Technical Reports Server (NTRS)

Ray, C. A.; Carter, J. R.

2003-01-01

AIM: The vestibulosympathetic reflex refers to sympathetic nerve activation by the vestibular system. Animal studies indicate that the vestibular system assists in blood pressure regulation during orthostasis. Although human studies clearly demonstrate activation of muscle sympathetic nerve activity (MSNA) during engagement of the otolith organs, the role of the vestibulosympathetic reflex in maintaining blood pressure during orthostasis is not well-established. Examination of the vestibulosympathetic reflex with other cardiovascular reflexes indicates that it is a powerful and independent reflex. Ageing, which is associated with an increased risk for orthostatic hypotension, attenuates the vestibulosympathetic reflex. The attenuated reflex is associated with a reduction in arterial pressure. CONCLUSION: These findings suggest that the vestibulosympathetic reflex assists in blood pressure regulation in humans, but future studies examining this reflex in other orthostatically intolerant populations are necessary to address this hypothesis.

Increasing Youth Physical Activity with Activity Calendars

ERIC Educational Resources Information Center

Eckler, Seth

2016-01-01

Physical educators often struggle with ways to get their students to be active beyond the school day. One strategy to accomplish this is the use of physical activity calendars (PACs). The purpose of this article is to support the use of PACs and give practical advice for creating effective PACs.

Activating AMP-activated protein kinase by an α1 selective activator compound 13 attenuates dexamethasone-induced osteoblast cell death

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

Guo, Shiguang; Mao, Li; Ji, Feng, E-mail: huaiaifengjidr@163.com

Excessive glucocorticoid (GC) usage may lead to non-traumatic femoral head osteonecrosis. Dexamethasone (Dex) exerts cytotoxic effect to cultured osteoblasts. Here, we investigated the potential activity of Compound 13 (C13), a novel α1 selective AMP-activated protein kinase (AMPK) activator, against the process. Our data revealed that C13 pretreatment significantly attenuated Dex-induced apoptosis and necrosis in both osteoblastic-like MC3T3-E1 cells and primary murine osteoblasts. AMPK activation mediated C13′ cytoprotective effect in osteoblasts. The AMPK inhibitor Compound C, shRNA-mediated knockdown of AMPKα1, or dominant negative mutation of AMPKα1 (T172A) almost abolished C13-induced AMPK activation and its pro-survival effect in osteoblasts. On the othermore » hand, forced AMPK activation by adding AMPK activator A-769662 or exogenous expression a constitutively-active (ca) AMPKα1 (T172D) mimicked C13's actions and inhibited Dex-induced osteoblast cell death. Meanwhile, A-769662 or ca-AMPKα1 almost nullified C13's activity in osteoblast. Further studies showed that C13 activated AMPK-dependent nicotinamide adenine dinucleotide phosphate (NADPH) pathway to inhibit Dex-induced reactive oxygen species (ROS) production in MC3T3-E1 cells and primary murine osteoblasts. Such effects by C13 were almost reversed by Compound C or AMPKα1 depletion/mutation. Together, these results suggest that C13 alleviates Dex-induced osteoblast cell death via activating AMPK signaling pathway. - Highlights: • Compound 13 (C13) attenuates dexamethasone (Dex)-induced osteoblast cell death. • C13-induced cytoprotective effect against Dex in osteoblasts requires AMPK activation. • Forced AMPK activation protects osteoblasts from Dex, nullifying C13's activities. • C13 increases NADPH activity and inhibits Dex-induced oxidative stress in osteoblasts.« less

Adolescents' Views on Active and Non-Active Videogames: A Focus Group Study.

PubMed

Simons, Monique; de Vet, Emely; Hoornstra, Sjoukje; Brug, Johannes; Seidell, Jaap; Chinapaw, Mai

2012-06-01

Active games require whole-body movement and may be an innovative tool to substitute sedentary pastime with more active time and may therefore contribute to adolescents' health. To inform strategies aimed at reducing sedentary behavior by replacing non-active with active gaming, perceptions and context of active and non-active gaming are explored. Six focus groups were conducted with adolescents 12-16 years old representing a range of education levels. A semistructured question route was used containing questions about perceptions and the context of gaming. The adolescents had positive attitudes toward active gaming, especially the social interactive aspect, which was greatly appreciated. A substantial number of adolescents enjoyed non-active games more than active ones, mainly because of better game controls and more diversity in non-active games. Active games were primarily played when there was a social gathering. Few game-related rules and restrictions at home were reported. Given the positive attitudes of adolescents and the limited restrictions for gaming at home, active videogames may potentially be used in a home setting as a tool to reduce sedentary behavior. However, to make active games as appealing as non-active games, attention should be paid to the quality, diversity, and sustainability of active games, as these aspects are currently inferior to those of traditional non-active games.

Assessing Adult Leisure Activities: An Extension of a Self-Report Activity Questionnaire

PubMed Central

Jopp, Daniela; Hertzog, Christopher

2009-01-01

Everyday leisure activities in adulthood and old age have been investigated with respect to constructs such as successful aging, an engaged lifestyle, and prevention of age-related cognitive decline. They also relate to mental health and have clinical value as they can inform diagnosis and interventions. In the present study, we enhanced the content validity of the Victoria Longitudinal Study activity questionnaire by adding items on physical and social activities, and validated a shortened version of the questionnaire. Our proposed leisure activity model included 11 activity categories: three types of social activities (i.e., activities with close social partners, group-centered public activity, religious activities), physical, developmental, and experiential activities, crafts, game playing, TV watching, travel, and technology use. Confirmatory factor analyses validated the proposed factor structure in two independent samples. A higher-order model with a general activity factor fitted the activity factor correlations with relatively little loss of fit. Convergent and discriminant validity for the activity scales were supported by patterns of their correlations with education, health, depression, cognition, and personality. In sum, the scores derived from of the augmented VLS activity questionnaire demonstrate good reliability, and validity evidence supports their use as measure of leisure activities in young, middle-aged, and older individuals. PMID:20230157

What Is an Activity? Appropriating an Activity-Centric System

NASA Astrophysics Data System (ADS)

Yarosh, Svetlana; Matthews, Tara; Moran, Thomas P.; Smith, Barton

Activity-Centric Computing (ACC) systems seek to address the fragmentation of office work across tools and documents by allowing users to organize work around the computational construct of an Activity. Defining and structuring appropriate Activities within a system poses a challenge for users that must be overcome in order to benefit from ACC support. We know little about how knowledge workers appropriate the Activity construct. To address this, we studied users’ appropriation of a production-quality ACC system, Lotus Activities, for everyday work by employees in a large corporation. We contribute to a better understanding of how users articulate their individual and collaborative work in the system by providing empirical evidence of their patterns of appropriation. We conclude by discussing how our findings can inform the design of other ACC systems for the workplace.

Active compounds, antioxidant activity and α-glucosidase inhibitory activity of different varieties of Chaenomeles fruits.

PubMed

Miao, Jing; Li, Xia; Zhao, Chengcheng; Gao, Xiaoxiao; Wang, Ying; Gao, Wenyuan

2018-05-15

Chaenomeles is an important source for food industry in China, and its planting area is expanding year by year. This study was conducted to evaluate different varieties of Chaenomeles by comparing the chemical compositions, antioxidant activity and α-glucosidase inhibitory activity of peels and fleshes from twelve varieties of Chaenomeles. In the results, peels of Chaenomeles contain more phenolics, flavonoids and triterpenes, and show better antioxidant activity and α-glucosidase inhibitory activity than their fleshes. All varieties of Chaenomeles perform different depend on cultivar and climatic conditions. Oleanolic acid, ursolic acid, protocatechuic acid, rutin, catechin, caffeic acid, syringic acid, epicatechin, hyperin, quercetin, kaempferol and chlorogenic acid are main active compounds in Chaenomeles. Zheng'an, Liufu, Zimugua1, Qijiang and Changjun get Top five scores. This is the first study on the peels and fleshes of twelve varieties of Chaenomeles, and it gives insights into variety selection in the planting and production of Chaenomeles. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immotile Active Matter: Activity from Death and Reproduction.

PubMed

Kalziqi, Arben; Yanni, David; Thomas, Jacob; Ng, Siu Lung; Vivek, Skanda; Hammer, Brian K; Yunker, Peter J

2018-01-05

Unlike equilibrium atomic solids, biofilms-soft solids composed of bacterial cells-do not experience significant thermal fluctuations at the constituent level. However, living cells stochastically reproduce and die, provoking a mechanical response. We investigate the mechanical consequences of cellular death and reproduction by measuring surface-height fluctuations of biofilms containing two mutually antagonistic strains of Vibrio cholerae that kill one another on contact via the type VI secretion system. While studies of active matter typically focus on activity via constituent mobility, here, activity is mediated by reproduction and death events in otherwise immobilized cells. Biofilm surface topography is measured in the nearly homeostatic limit via white light interferometry. Although biofilms are far from equilibrium systems, measured surface-height fluctuation spectra resemble the spectra of thermal permeable membranes but with an activity-mediated effective temperature, as predicted by Risler, Peilloux, and Prost [Phys. Rev. Lett. 115, 258104 (2015)PRLTAO0031-900710.1103/PhysRevLett.115.258104]. By comparing the activity of killer strains of V. cholerae with that of genetically modified strains that cannot kill each other and validating with individual-based simulations, we demonstrate that extracted effective temperatures increase with the amount of death and reproduction and that death and reproduction can fluidize biofilms. Together, these observations demonstrate the unique physical consequences of activity mediated by death and reproduction events.

Immotile Active Matter: Activity from Death and Reproduction

NASA Astrophysics Data System (ADS)

Kalziqi, Arben; Yanni, David; Thomas, Jacob; Ng, Siu Lung; Vivek, Skanda; Hammer, Brian K.; Yunker, Peter J.

2018-01-01

Unlike equilibrium atomic solids, biofilms—soft solids composed of bacterial cells—do not experience significant thermal fluctuations at the constituent level. However, living cells stochastically reproduce and die, provoking a mechanical response. We investigate the mechanical consequences of cellular death and reproduction by measuring surface-height fluctuations of biofilms containing two mutually antagonistic strains of Vibrio cholerae that kill one another on contact via the type VI secretion system. While studies of active matter typically focus on activity via constituent mobility, here, activity is mediated by reproduction and death events in otherwise immobilized cells. Biofilm surface topography is measured in the nearly homeostatic limit via white light interferometry. Although biofilms are far from equilibrium systems, measured surface-height fluctuation spectra resemble the spectra of thermal permeable membranes but with an activity-mediated effective temperature, as predicted by Risler, Peilloux, and Prost [Phys. Rev. Lett. 115, 258104 (2015), 10.1103/PhysRevLett.115.258104]. By comparing the activity of killer strains of V. cholerae with that of genetically modified strains that cannot kill each other and validating with individual-based simulations, we demonstrate that extracted effective temperatures increase with the amount of death and reproduction and that death and reproduction can fluidize biofilms. Together, these observations demonstrate the unique physical consequences of activity mediated by death and reproduction events.

Macrophage activating activity of pyrrole alkaloids from Morus alba fruits.

PubMed

Kim, Seon Beom; Chang, Bo Yoon; Jo, Yang Hee; Lee, Sang Hoon; Han, Sang-Bae; Hwang, Bang Yeon; Kim, Sung Yeon; Lee, Mi Kyeong

2013-01-09

The fruits of Morus alba have been traditionally used as a tonic to enhance immune responses. The macrophage activating constituents of Morus alba fruits were purified using various column chromatography techniques. The structures of isolated compounds were determined on the basis of spectroscopic data interpretation such as 1D and 2D NMR analysis. The macrophage activating activities of isolated compounds were evaluated by measuring the production of nitric oxide, TNF-α and IL-12 in RAW 264.7 cells. The phagocytic activity was also evaluated. Five pyrrole alkaloids, 5-(hydroxymethyl)-1H-pyrrole-2-carboxaldehyde (1), 2-formyl-1H-pyrrole-1-butanoic acid (2), 2-formyl-5-(hydroxymethyl)-1H-pyrrole-1-butanoic acid (3), 2-formyl-5-(methoxymethyl)-1H-pyrrole-1-butanoic acid (4) and Morrole A (5) were isolated from the fruits of Morus alba. Morrole A (5) is first reported in nature and other pyrrole alkaloids (1-4) are first reported from Morus species. Among the isolated compounds, compounds 3 and 4 significantly activated macrophage activity by the enhancement of nitric oxide, TNF-α and IL-12 production, and the stimulation of phagocytic activity in RAW 264.7 cells. Pyrrole alkaloids, including a new compound, were isolated from Morus alba fruits. These compounds activated macrophage activity in RAW 264.7 cells. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Is constipation associated with decreased physical activity in normally active subjects?

PubMed

Tuteja, Ashok K; Talley, Nicholas J; Joos, Sandra K; Woehl, James V; Hickam, David H

2005-01-01

The effectiveness of physical activity in the management of constipation remains controversial. We examined the associations among physical activity, constipation, and quality of life (QoL) in a population of employed adults to determine whether the risk of constipation is related to physical activity. A total of 1,069 employees (age range 24-77) of the Veterans Affairs (VA) Black Hills Health Care System were mailed validated questionnaires (response rate 72%), inquiring about bowel habits, QoL (SF 36), and physical activity (modified Baecke questionnaire). Constipation was defined using the Rome I criteria. One hundred and forty (19.4%, 95% CI 16.2-22.4) employees reported constipation. The average total physical activity and all subscales of physical activity were not significantly different in subjects with and without constipation (all p > or = 0.2). Subjects with constipation had lower QoL scores than subjects without constipation, and physical activity was positively correlated with physical functioning and health perception. Physical activity appears to be unrelated to the risk of constipation in employed adults, but higher physical activity was associated with improved QoL. Recommendations to increase physical activity may not alter symptoms of constipation but may improve overall well-being.

Comparison of passive and active leisure activities and life satisfaction with aging.

PubMed

Cho, Dongwook; Post, Jay; Kim, Sung Kyeom

2018-03-01

Many older adults face limitations to participating in active leisure activities as a result of their physical constraints from aging. Passive leisure activities become alternative leisure activities for older adults as a result of limited physical capacity. The present study sought to determine whether there exists a difference in the frequency of participation in passive and active leisure activities, and the effect of participation in passive and active leisure activities on the life satisfaction level of old adults. A total of 460 participants aged 60-95 years were randomly selected from 21 sites in the USA. The Life Satisfaction Index - Z and the Meaningful Activity Participation Assessment were analyzed to examine older adults' life satisfaction and frequency of active or passive activities. The results showed that participation in passive leisure activities, such reading, talking on the telephone and watching TV/listening to the radio, is more frequent among older adults (P = 0.000). The regression coefficient found that club/organization or volunteering (P = 0.008), homemaking/maintenance (P = 0.017) and traveling (P = 0.017) for active leisure activities were statistically significant predictors of Life Satisfaction Index - Z for older adults. The current study shows that older adults spent much more times participating in passive leisure activities, such as radio/watching TV, talking on the phone and reading. The result also showed that active leisure activities, such as club/organization or volunteering, home making/maintenance and traveling, were significant predictors of life satisfaction for older adults controlling for covariates. The current study suggests marketing and programming plans to overcome the constraints that influence older adults' life satisfaction. Geriatr Gerontol Int 2018; 18: 380-386. © 2017 Japan Geriatrics Society.

Transcriptional activation of peroxisome proliferator-activated receptor-{gamma} requires activation of both protein kinase A and Akt during adipocyte differentiation

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

Kim, Sang-pil; Ha, Jung Min; Yun, Sung Ji

2010-08-13

Research highlights: {yields} Elevated cAMP activates both PKA and Epac. {yields} PKA activates CREB transcriptional factor and Epac activates PI3K/Akt pathway via Rap1. {yields} Akt modulates PPAR-{gamma} transcriptional activity in concert with CREB. -- Abstract: Peroxisome proliferator-activated receptor-{gamma} (PPAR-{gamma}) is required for the conversion of pre-adipocytes. However, the mechanism underlying activation of PPAR-{gamma} is unclear. Here we showed that cAMP-induced activation of protein kinase A (PKA) and Akt is essential for the transcriptional activation of PPAR-{gamma}. Hormonal induction of adipogenesis was blocked by a phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002), by a protein kinase A (PKA) inhibitor (H89), and by amore » Rap1 inhibitor (GGTI-298). Transcriptional activity of PPAR-{gamma} was markedly enhanced by 3-isobutyl-1-methylxanthine (IBMX), but not insulin and dexamethasone. In addition, IBMX-induced PPAR-{gamma} transcriptional activity was blocked by PI3K/Akt, PKA, or Rap1 inhibitors. 8-(4-Chlorophenylthio)-2'-O-methyl-cAMP (8-pCPT-2'-O-Me-cAMP) which is a specific agonist for exchanger protein directly activated by cAMP (Epac) significantly induced the activation of Akt. Furthermore, knock-down of Akt1 markedly attenuated PPAR-{gamma} transcriptional activity. These results indicate that both PKA and Akt signaling pathways are required for transcriptional activation of PPAR-{gamma}, suggesting post-translational activation of PPAR-{gamma} might be critical step for adipogenic gene expression.« less

Activity Engagement and Activity-Related Experiences: The Role of Personality.

PubMed

Newton, Nicky J; Pladevall-Guyer, Jana; Gonzalez, Richard; Smith, Jacqui

2016-08-12

The associations of personality with activity participation and well-being have been well studied. However, less is known concerning the relationship between personality and specific aspects of activity engagement in older adults. We conducted a fine-grained examination of the effects of extraversion and conscientiousness on reported activity engagement-which we define as participation, time allocated, and affective experience-during 8 everyday activities. Data were obtained using a day reconstruction measure from a subgroup of participants in the 2012 Health and Retirement Study (HRS: N = 5,484; mean age = 67.98 years). We found mixed support for hypotheses suggesting that specific personality traits would be associated with activity participation, time allocated, and activity-affective experience. For example, extraverts were more likely to socialize and experienced higher socializing-related positive affect, but did not spend more time socializing. Results are discussed in light of the value of including personality in, and its contribution to, studies of activity engagement in later life. In addition, the need to acknowledge the complexity of the concept of activity engagement in future research is highlighted. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Multi-day activity scheduling reactions to planned activities and future events in a dynamic model of activity-travel behavior

NASA Astrophysics Data System (ADS)

Nijland, Linda; Arentze, Theo; Timmermans, Harry

2014-01-01

Modeling multi-day planning has received scarce attention in activity-based transport demand modeling so far. However, new dynamic activity-based approaches are being developed at the current moment. The frequency and inflexibility of planned activities and events in activity schedules of individuals indicate the importance of incorporating those pre-planned activities in the new generation of dynamic travel demand models. Elaborating and combining previous work on event-driven activity generation, the aim of this paper is to develop and illustrate an extension of a need-based model of activity generation that takes into account possible influences of pre-planned activities and events. This paper describes the theory and shows the results of simulations of the extension. The simulation was conducted for six different activities, and the parameter values used were consistent with an earlier estimation study. The results show that the model works well and that the influences of the parameters are consistent, logical, and have clear interpretations. These findings offer further evidence of face and construct validity to the suggested modeling approach.

Toxicity tests, antioxidant activity, and antimicrobial activity of chitosan

NASA Astrophysics Data System (ADS)

Kurniasih, M.; Purwati; Dewi, R. S.

2018-04-01

Chitosan is a naturally occurring cationic biopolymer, obtained by alkaline deacetylation of chitin. This research aims to investigate the toxicity, antioxidant activity and antibacterial activity of chitosan from shrimp chitin. In this study, chitin extracted from shrimp waste material. Chitin is then deacetylation with 60% NaOH so that chitosan produced. Degrees of deacetylation, molecular weight, toxicity test, antioxidant activity and antimicrobial activity of chitosan then evaluated. Toxicity test using Brine Shrimp Lethality Test. The antioxidant analysis was performed using DPPH method (2, 2-diphenyl-1-picrylhydrazyl) and FTC method (ferric thiocyanate) in which the radical formed will reduce Ferro to Ferri resulting in a complex with thiocyanate. To determine the antibacterial activity of Staphylococcus aureus, antifungal in Candida albicans and Aspergillus niger by measuring antimicrobial effects and minimum inhibitory concentrations (MIC). Based on the result of research, the value of degrees of deacetylation, molecular weight, and LC50 values of chitosan synthesis was 94,32, 1052.93 g/mol and 1364.41 ppm, respectively. In general, the antioxidative activities increased as the concentration of chitosan increased. MIC value of chitosan against S. aureus, C. albicans, and A. niger was 10 ppm, 15.6 ppm, and 5 ppm, respectively.

Differential Activity-Driven Instabilities in Biphasic Active Matter

NASA Astrophysics Data System (ADS)

Weber, Christoph A.; Rycroft, Chris H.; Mahadevan, L.

2018-06-01

Active stresses can cause instabilities in contractile gels and living tissues. Here we provide a generic hydrodynamic theory that treats these systems as a mixture of two phases of varying activity and different mechanical properties. We find that differential activity between the phases causes a uniform mixture to undergo a demixing instability. We follow the nonlinear evolution of the instability and characterize a phase diagram of the resulting patterns. Our study complements other instability mechanisms in mixtures driven by differential adhesion, differential diffusion, differential growth, and differential motion.

Physical activity behavior and related characteristics of highly active eighth-grade girls.

PubMed

Taverno Ross, Sharon E; Dowda, Marsha; Beets, Michael W; Pate, Russell R

2013-06-01

Although girls are generally less physically active than boys, some girls regularly engage in high levels of physical activity (PA); however, very little is known about these girls and how they differ from those who are less physically active. This study examined the PA behavior and related characteristics of highly active adolescent girls and compared them with those who are less active. Data from 1,866 eighth-grade girls from six field centers across the United States participating in the Trial of Activity for Adolescent Girls (TAAG) were included in the present analysis. Mixed-model analysis of variance examined differences in sociodemographic, anthropometric, psychosocial, and physical activity (accelerometry and self-report) variables between high- and low-active girls; effect sizes were calculated for the differences. High-active girls were taller, had lower body mass indices and body fat, and were less sedentary. High-active girls scored higher on self-efficacy, enjoyment of PA, self-management strategies, outcome-expectancy value, and support from family and friends than low-active girls. Low-active girls participated in more leisure time and educational sedentary activities than high-active girls. High-active girls participated in more PA classes/lessons outside of school, team sports, and individual sports. They were also more likely to participate in sports in an organized setting in the community or at school than low-active girls. Health promotion efforts should focus on decreasing the amount of time girls spend in sedentary activities and replacing that time with organized PA opportunities; such efforts should seek to minimize perceived barriers and increase self-efficacy and support for PA. Copyright © 2013 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Physical activity energy expenditure in Dutch adolescents: contribution of active transport to school, physical education, and leisure time activities.

PubMed

Slingerland, Menno; Borghouts, Lars B; Hesselink, Matthijs K C

2012-05-01

Detailed knowledge about physical activity energy expenditure (PAEE) can guide the development of school interventions aimed at reducing overweight in adolescents. However, relevant components of PAEE have never been objectively quantified in this population. This study investigated the contribution of active transport to and from school, physical education (PE), and leisure time activities to total PAEE during a regular school week in adolescents. Seventy-three adolescents (mean age: 15.7 years) wore an individually calibrated combined heart rate-acceleration monitor and kept an activity diary during a regular school week. Branched equation modeling was used to calculate PAEE of the specific activity categories, and their relative contribution to total PAEE was determined. Active transport and PE contributed 30.0% and 17.4%, respectively, to school-related PAEE. Active transport to and from school contributed 15% to total PAEE. Youth with a high physical activity level (PAL) spent 4 hours less in sedentary behavior than subjects with a medium or low PAL (F = 77.415 (2.70), p < .001) and had higher PAEE during leisure time sports (F = 9.135 (2.70), p < .001) and work-related activities (F = 10.583 (2.70), p < .001) than youth with medium or low PAL values. Active transport and PE contribute significantly to PAEE during school hours in adolescents. To achieve an increase in total PAEE in the least active group of adolescents, promising strategies might be to reduce inactive behavior, increase participation in leisure time sports, and possibly to replace inactive for active jobs. © 2012, American School Health Association.

Nursing activities score.

PubMed

Miranda, Dinis Reis; Nap, Raoul; de Rijk, Angelique; Schaufeli, Wilmar; Iapichino, Gaetano

2003-02-01

The instruments used for measuring nursing workload in the intensive care unit (e.g., Therapeutic Intervention Scoring System-28) are based on therapeutic interventions related to severity of illness. Many nursing activities are not necessarily related to severity of illness, and cost-effectiveness studies require the accurate evaluation of nursing activities. The aim of the study was to determine the nursing activities that best describe workload in the intensive care unit and to attribute weights to these activities so that the score describes average time consumption instead of severity of illness. To define by consensus a list of nursing activities, to determine the average time consumption of these activities by use of a 1-wk observational cross-sectional study, and to compare these results with those of the Therapeutic Intervention Scoring System-28. A total of 99 intensive care units in 15 countries. Consecutive admissions to the intensive care units. Daily recording of nursing activities at a patient level and random multimoment recording of these activities. A total of five new items and 14 subitems describing nursing activities in the intensive care unit (e.g., monitoring, care of relatives, administrative tasks) were added to the list of therapeutic interventions in Therapeutic Intervention Scoring System-28. Data from 2,041 patients (6,451 nursing days and 127,951 multimoment recordings) were analyzed. The new activities accounted for 60% of the average nursing time; the new scoring system (Nursing Activities Score) explained 81% of the nursing time (vs. 43% in Therapeutic Intervention Scoring System-28). The weights in the Therapeutic Intervention Scoring System-28 are not derived from the use of nursing time. Our study suggests that the Nursing Activities Score measures the consumption of nursing time in the intensive care unit. These results should be validated in independent databases.

[Positive Activities Campaign.

ERIC Educational Resources Information Center

Substance Abuse and Mental Health Services Administration (DHHS/PHS), Rockville, MD. Center for Substance Abuse Prevention.

This packet contains four pamphlets that are part of a campaign to encourage adults to provide and promote positive activities for youth and to serve as role models for young people. "Positive Activities: A Campaign for Youth" includes information on what positive activities are, how to get involved in helping to provide positive activities for…

Active Volcanism on Io: Global Distribution and Variations in Activity

USGS Publications Warehouse

Lopes-Gautier, R.; McEwen, A.S.; Smythe, W.B.; Geissler, P.E.; Kamp, L.; Davies, A.G.; Spencer, J.R.; Keszthelyi, L.; Carlson, R.; Leader, F.E.; Mehlman, R.; Soderblom, L.

1999-01-01

Io's volcanic activity has been monitored by instruments aboard the Galileo spacecraft since June 28, 1996. We present results from observations by the near-infrared mapping spectrometer (NIMS) for the first 10 orbits of Galileo, correlate them with results from the Solid State Imaging System (SSI) and from groundbased observations, and compare them to what was known about Io's volcanic activity from observations made during the two Voyager flybys in 1979. A total of 61 active volcanic centers have been identified from Voyager, groundbased, and Galileo observations. Of these, 41 are hot spots detected by NIMS and/or SSI. Another 25 locations were identified as possible active volcanic centers, mostly on the basis of observed surface changes. Hot spots are correlated with surface colors, particularly dark and red deposits, and generally anti-correlated with white, SO2-rich areas. Surface features corresponding to the hot spots, mostly calderas or flows, were identified from Galileo and Voyager images. Hot spot temperatures obtained from both NIMS and SSI are consistent with silicate volcanism, which appears to be widespread on Io. Two types of hot spot activity are present: persistent-type activity, lasting from months to years, and sporadic events, which may represent either short-lived activity or low-level activity that occasionally flares up. Sporadic events are not often detected, but may make an important contribution to Io's heat flow and resurfacing. The distribution of active volcanic centers on the surface does not show any clear correlation with latitude, longitude, Voyager-derived global topography, or heat flow patterns predicted by the asthenosphere and deep mantle tidal dissipation models. However, persistent hot spots and active plumes are concentrated toward lower latitudes, and this distribution favors the asthenosphere rather than the deep mantle tidal dissipation model. ?? 1999 Academic Press.

Association between sedentary behavior, physical activity, and obesity: inactivity among active kids.

PubMed

Wong, Suzy L; Leatherdale, Scott T

2009-01-01

Sedentary behavior and physical activity are not mutually exclusive behaviors. The relative risk of overweight for adolescents who are highly sedentary and highly physically active is unclear. A better understanding of the relationship between sedentary behaviors, physical activity, and body mass index (BMI) would provide insight for developing interventions to prevent or reduce overweight. Using the physical activity module of the School Health Action, Planning and Evaluation System (SHAPES), we collected data from 25,060 students in grades 9 through 12 from 76 secondary schools in Ontario, Canada. Sex-specific logistic regression analyses were performed to examine how BMI, weight perceptions, social influences, team sports participation, and smoking behavior were associated with being 1) high active-high sedentary, 2) low active-low sedentary, and 3) low active-high sedentary. Low active-high sedentary boys were more likely to be overweight than high active-low sedentary boys (adjusted odds ratio [AOR], 1.60; 95% confidence interval [CI], 1.01-2.58). When compared with high active-low sedentary girls, girls who were low active-high sedentary (OR, 2.24; 95% CI, 1.23-4.09) or high active-high sedentary (OR, 1.91; 95% CI, 1.01-3.61) were more likely to be overweight. Sedentary behavior may moderate the relationship between physical activity and overweight. Developing a better understanding of sedentary behavior in relation to physical activity and overweight is critical for preventing and reducing overweight among youth.

Worksite physical activity policies and environments in relation to employee physical activity.

PubMed

Crespo, Noe C; Sallis, James F; Conway, Terry L; Saelens, Brian E; Frank, Lawrence D

2011-01-01

Examine associations between worksite physical activity promotion strategies and employees' physical activity and sedentary behaviors. Cross-sectional. Seattle-King County, Washington and Baltimore, Maryland-Washington, D.C. regions. Adults working outside the home (n = 1313). Mean age was 45 ± 10 years, 75.8% of participants were non-Hispanic white, 56% were male, and 51% had income ≥$70,000/year. Participants reported demographic characteristics and presence/absence of nine physical activity promotion environment and policy strategies in their work environment (e.g., showers, lockers, physical activity programs). A worksite physical activity promotion index was a tally of strategies. Total sedentary and moderate-to-vigorous physical activity (MVPA) min/d were objectively assessed via 7-day accelerometry. Total job-related physical activity minutes and recreational physical activity minutes were self-reported with the International Physical Activity Questionnaire. Mixed-effects models and generalized estimating equations evaluated the association of the worksite promotion index with physical activity and sedentary behavior, adjusting for demographics. A higher worksite promotion index was significantly associated with higher total sedentary behavior (β = 3.97), MVPA (β = 1.04), recreational physical activity (β = 1.1 and odds ratio = 1.39; away from work and at work, respectively) and negatively with job-related physical activity (β = .90). Multiple worksite physical activity promotion strategies based on environmental supports and policies may increase recreational physical activity and should be evaluated in controlled trials. These findings are particularly important given the increasingly sedentary nature of employment.

Forum: Communication Activism Pedagogy. Turning Communication Activism Pedagogy Teaching into Communication Activism Pedagogy Research

ERIC Educational Resources Information Center

Frey, Lawrence R.; Palmer, David L.

2017-01-01

In this rejoinder to this forum's respondents to the stimulus essay, "Communication Activism Pedagogy and Research: Communication Education Scholarship to Promote Social Justice," Lawrence Frey and David Palmer state that the forum editors asked them and the invited respondents to focus on communication activism pedagogy (CAP) research…

Leisure-time physical activity in relation to occupational physical activity among women.

PubMed

Ekenga, Christine C; Parks, Christine G; Wilson, Lauren E; Sandler, Dale P

2015-05-01

The objective of this study is to examine the association between occupational physical activity and leisure-time physical activity among US women in the Sister Study. We conducted a cross-sectional study of 26,334 women who had been employed in their current job for at least 1 year at baseline (2004-2009). Occupational physical activity was self-reported and leisure-time physical activity was estimated in metabolic equivalent hours per week. Log multinomial regression was used to evaluate associations between occupational (sitting, standing, manually active) and leisure-time (insufficient, moderate, high) activity. Models were adjusted for age, race/ethnicity, education, income, geographic region, and body mass index. Only 54% of women met or exceeded minimum recommended levels of leisure-time physical activity (moderate 32% and high 22%). Women who reported sitting (prevalence ratio (PR)=0.82, 95% confidence interval (CI): 0.74-0.92) or standing (PR=0.84, 95% CI: 0.75-0.94) most of the time at work were less likely to meet the requirements for high leisure-time physical activity than manually active workers. Associations were strongest among women living in the Northeast and the South. In this nationwide study, low occupational activity was associated with lower leisure-time physical activity. Women who are not active in the workplace may benefit from strategies to promote leisure-time physical activity. Published by Elsevier Inc.

Leisure-time physical activity in relation to occupational physical activity among women

PubMed Central

Ekenga, Christine C.; Parks, Christine G.; Wilson, Lauren E.; Sandler, Dale P.

2017-01-01

Objective To examine the association between occupational physical activity and leisure-time physical activity among US women in the Sister Study. Methods We conducted a cross-sectional study of 26,334 women who had been employed in their current job for at least 1 year at baseline (2004–2009). Occupational physical activity was self-reported and leisure-time physical activity was estimated in metabolic equivalent hours per week. Log multinomial regression was used to evaluate associations between occupational (sitting, standing, manually active) and leisure-time (insufficient, moderate, high) activity. Models were adjusted for age, race/ethnicity, education, income, geographic region, and body mass index. Results Only 54% of women met or exceeded minimum recommended levels of leisure-time physical activity (moderate 32% and high 22%). Women who reported sitting (PR = 0.82, 95% CI: 0.74–0.92) or standing (PR = 0.84, 95% CI: 0.75–0.94) most of the time at work were less likely to meet the requirements for high leisure-time physical activity than manually active workers. Associations were strongest among women living in the Northeast and the South. Conclusion In this nationwide study, low occupational activity was associated with lower leisure-time physical activity. Women who are not active in the workplace may benefit from strategies to promote leisure-time physical activity. PMID:25773471

Emodin Regulates Glucose Utilization by Activating AMP-activated Protein Kinase*

PubMed Central

Song, Parkyong; Kim, Jong Hyun; Ghim, Jaewang; Yoon, Jong Hyuk; Lee, Areum; Kwon, Yonghoon; Hyun, Hyunjung; Moon, Hyo-Youl; Choi, Hueng-Sik; Berggren, Per-Olof; Suh, Pann-Ghill; Ryu, Sung Ho

2013-01-01

AMP-activated protein kinase has been described as a key signaling protein that can regulate energy homeostasis. Here, we aimed to characterize novel AMP-activated kinase (AMPK)-activating compounds that have a much lower effective concentration than metformin. As a result, emodin, a natural anthraquinone derivative, was shown to stimulate AMPK activity in skeletal muscle and liver cells. Emodin enhanced GLUT4 translocation and [14C]glucose uptake into the myotube in an AMPK-dependent manner. Also, emodin inhibited glucose production by suppressing the expression of key gluconeogenic genes, such as phosphoenolpyruvate carboxykinase and glucose-6-phosphatase, in hepatocytes. Furthermore, we found that emodin can activate AMPK by inhibiting mitochondrial respiratory complex I activity, leading to increased reactive oxygen species and Ca2+/calmodulin-dependent protein kinase kinase activity. Finally, we confirmed that a single dose administration of emodin significantly decreased the fasting plasma glucose levels and improved glucose tolerance in C57Bl/6J mice. Increased insulin sensitivity was also confirmed after daily injection of emodin for 8 days using an insulin tolerance test and insulin-stimulated PI3K phosphorylation in wild type and high fat diet-induced diabetic mouse models. Our study suggests that emodin regulates glucose homeostasis in vivo by AMPK activation and that this may represent a novel therapeutic principle in the treatment of type 2 diabetic models. PMID:23303186

Lactate dehydrogenase activity drives hair follicle stem cell activation

PubMed Central

Aimee, Flores; John, Schell; Abby, Krall; David, Jelinek; Matilde, Miranda; Melina, Grigorian; Daniel, Braas; White Andrew, C; Jessica, Zhou; Nick, Graham; Thomas, Graeber; Pankaj, Seth; Denis, Evseenko; Hilary, Coller; Jared, Rutter; Heather, Christofk; Lowry William, E

2017-01-01

Summary While normally dormant, Hair Follicle Stem Cells (HFSCs) quickly become activated to divide during a new hair cycle. The quiescence of HFSCs is known to be regulated by a number of intrinsic and extrinsic mechanisms. Here we provide several lines of evidence to demonstrate that HFSCs utilize glycolytic metabolism and produce significantly more lactate than other cells in the epidermis. Furthermore, lactate generation appears to be critical for the activation of HFSCs as deletion of lactate dehydrogenase (Ldha) prevented their activation. Conversely, genetically promoting lactate production in HFSCs through mitochondrial pyruvate carrier (Mpc1) deletion accelerated their activation and the hair cycle. Finally, we identify small molecules that increase lactate production by stimulating Myc levels or inhibiting Mpc1 carrier activity and can topically induce the hair cycle. These data suggest that HFSCs maintain a metabolic state that allow them to remain dormant and yet quickly respond to appropriate proliferative stimuli. PMID:28812580

Physical Activity Basics

MedlinePlus

... Weight Breastfeeding Micronutrient Malnutrition State and Local Programs Physical Activity Basics Recommend on Facebook Tweet Share Compartir How much physical activity do you need? Regular physical activity helps improve ...

Riluzole activates TRPC5 channels independently of PLC activity

PubMed Central

Richter, Julia M; Schaefer, Michael; Hill, Kerstin

2014-01-01

BACKGROUND AND PURPOSE The transient receptor potential channel C5 (TRPC5) is a Ca2+-permeable cation channel, which is predominantly expressed in the brain. TRPC5 is activated in a PLC-dependent manner by, as yet, unidentified endogenous messengers. Recently, modulators of TRPC5, like Ca2+, pH and phospholipids, have been identified. However, the role of TRPC5 in vivo is only poorly understood. Novel specific modulators of TRPC5 might help to elucidate its function. EXPERIMENTAL APPROACH Novel modulators of TRPC5 were identified in a compound screening of approved drugs and natural compounds. The potency and selectivity of TRPC5-activating compounds were determined by fluorometric calcium imaging. The biophysical properties of channel activation by these compounds were analysed using electrophysiological measurements. KEY RESULTS Riluzole was identified as a novel activator of TRPC5 (EC50 9.2 ± 0.5 μM) and its mechanism of action was shown to be independent of G protein signalling and PLC activity. Riluzole-induced TRPC5 currents were potentiated by La3+ and, utilizing TRPC5 mutants that lack La3+ binding sites, it was confirmed that riluzole and La3+ activate TRPC5 by different mechanisms. Recordings of excised inside-out patches revealed a relatively direct effect of riluzole on TRPC5. CONCLUSIONS AND IMPLICATIONS Riluzole can activate TRPC5 heterologously expressed in HEK293 cells as well as those endogenously expressed in the U-87 glioblastoma cell line. Riluzole does not activate any other member of the TRPC family and could, therefore, despite its action on other ion channels, be a useful pharmacological tool for identifying TRPC5-specific currents in immortalized cell lines or in acutely isolated primary cells. PMID:24117252

Requirement of GM2 ganglioside activator for phospholipase D activation

PubMed Central

Nakamura, Shun-ichi; Akisue, Toshihiro; Jinnai, Hitoshi; Hitomi, Tomohiro; Sarkar, Sukumar; Miwa, Noriko; Okada, Taro; Yoshida, Kimihisa; Kuroda, Shun’ichi; Kikkawa, Ushio; Nishizuka, Yasutomi

1998-01-01

Sequence analysis of a heat-stable protein necessary for the activation of ADP ribosylation factor-dependent phospholipase D (PLD) reveals that this protein has a structure highly homologous to the previously known GM2 ganglioside activator whose deficiency results in the AB-variant of GM2 gangliosidosis. The heat-stable activator protein indeed has the capacity to enhance enzymatic conversion of GM2 to GM3 ganglioside that is catalyzed by β-hexosaminidase A. Inversely, GM2 ganglioside activator purified separately from tissues as described earlier [Conzelmann, E. & Sandhoff, K. (1987) Methods Enzymol. 138, 792–815] stimulates ADP ribosylation factor-dependent PLD in a dose-dependent manner. At higher concentrations of ammonium sulfate, the PLD activator protein apparently substitutes for protein kinase C and phosphatidylinositol 4,5-bisphosphate, both of which are known as effective stimulators of the PLD reaction. The mechanism of action of the heat-stable PLD activator protein remains unknown. PMID:9770472

Activity Based Curriculum for Elementary Education. Additional Activities, K-6.

ERIC Educational Resources Information Center

Wichita Public Schools, KS.

This elementary curriculum is a vehicle to provide manipulative activities that reinforce academic skills through meaningful, relevant, activity-based awareness of modern society. The twenty-six activity plans included in the curriculum place a major emphasis upon realistic or concrete experiences that deal with the manipulation and exploration of…

Demo of Active Resonators on the Active Noise Control Fan

NASA Image and Video Library

1998-10-01

NASA has been involved in several projects to reduce aircraft engine noise. In the 1990s Active Noise Control was investigated as a potential method to reduce aircraft engine noise. A description and demonstration of Active Resonators on the Active Noise Control Fan is shown in this video.

Examining Activism in Practice: A Qualitative Study of Archival Activism

ERIC Educational Resources Information Center

Novak, Joy Rainbow

2013-01-01

While archival literature has increasingly discussed activism in the context of archives, there has been little examination of the extent to which archivists in the field have accepted or incorporated archival activism into practice. Scholarship that has explored the practical application of archival activism has predominately focused on case…

Active8! Technology-Based Intervention to Promote Physical Activity in Hospital Employees.

PubMed

Blake, Holly; Suggs, L Suzanne; Coman, Emil; Aguirre, Lucia; Batt, Mark E

2017-03-01

Increase physical activity in health care employees using health messaging, and compare e-mail with mobile phone short-message service (SMS) as delivery channels. Randomized controlled trial Setting. U.K. hospital workplace. Two hundred ninety-six employees (19-67 years, 53% of study Web site visitors). Twelve-week messaging intervention designed to increase physical activity and delivered via SMS (n =147) or e-mail (n =149); content tailored using theory of planned behavior (TPB) and limited to 160 characters. Baseline and 6, 12, and 16 weeks. Online measures included TPB constructs, physical activity behavior on the Global Physical Activity Questionnaire, and health-related quality of life on the Short-Form 12. General linear models for repeated measures. Increase in duration (mean h/d) of moderate work-related activity and moderate recreational activity from baseline to 16 weeks. Short-lived increase in frequency (d/wk) of vigorous recreational activity from baseline to 6 weeks. Increase in duration and frequency of active travel from baseline to 16 weeks. E-mails generated greater changes than SMS in active travel and moderate activity (work and recreational). Minimal physical activity promotion delivered by SMS or e-mail can increase frequency and duration of active travel and duration of moderate intensity physical activity at work and for leisure, which is maintained up to 1 month after messaging ends. Both channels were useful platforms for health communication; e-mails were particularly beneficial with hospital employees.

Activated carbon from peach stones using phosphoric acid activation at medium temperatures.

PubMed

Kim, Dong-Su

2004-01-01

In the present study, the activation features of phosphoric acid have been investigated using waste peach stones as the raw material in the production of granular activated carbon. Thermogravimetry/differential thermal analysis was conducted to characterize the thermal behavior of peach stone and titration method was used to evaluate the adsorption capacity of the produced activated carbon. It was observed that the iodine value of the activated carbon increased with activation temperature. However, temperatures higher than 500 degrees C caused a thermal destruction, which resulted in the decrease of the adsorption capacity. Activation longer than 1.5 h at 500 degrees C resulted in thermal degradation of the porous structure of the activated carbon. The adsorption capacity was enhanced with increasing of amounts of phosphoric acid, however, excessive phosphoric acid caused a decrease in the iodine value. In addition, it was found that the carbon yields generally decreased with activation temperature and activation time. Scanning electron microscopy analysis was conducted to observe the changes in the poros structure of the activated carbon produced in different temperatures. Activation of carbon by phosphoric acid was found to be superior to that by CaCl2 and gas activation. The activated carbon produced from peach stone was applied as an adsorbent in the treatment of synthesized wastewater containing cadmium ion and its adsorption capacity was found to be as good as that of the commercial one.

Simultaneous Fluorescent Gram Staining and Activity Assessment of Activated Sludge Bacteria

PubMed Central

Forster, Scott; Snape, Jason R.; Lappin-Scott, Hilary M.; Porter, Jonathan

2002-01-01

Wastewater treatment is one of the most important commercial biotechnological processes, and yet the component bacterial populations and their associated metabolic activities are poorly understood. The novel fluorescent dye hexidium iodide allows assessment of Gram status by differential absorption through bacterial cell walls. Differentiation between gram-positive and gram-negative wastewater bacteria was achieved after flow cytometric analysis. This study shows that the relative proportions of gram-positive and gram-negative bacterial cells identified by traditional microscopy and hexidium iodide staining were not significantly different. Dual staining of cells for Gram status and activity proved effective in analyzing mixtures of cultured bacteria and wastewater populations. Levels of highly active organisms at two wastewater treatment plants, both gram positive and gram negative, ranged from 1.5% in activated sludge flocs to 16% in the activated sludge fluid. Gram-positive organisms comprised <5% of the total bacterial numbers but accounted for 19 and 55% of the highly active organisms within flocs at the two plants. Assessment of Gram status and activity within activated sludge samples over a 4-day period showed significant differences over time. This method provides a rapid, quantitative measure of Gram status linked with in situ activity within wastewater systems. PMID:12324319

Simultaneous fluorescent gram staining and activity assessment of activated sludge bacteria.

PubMed

Forster, Scott; Snape, Jason R; Lappin-Scott, Hilary M; Porter, Jonathan

2002-10-01

Wastewater treatment is one of the most important commercial biotechnological processes, and yet the component bacterial populations and their associated metabolic activities are poorly understood. The novel fluorescent dye hexidium iodide allows assessment of Gram status by differential absorption through bacterial cell walls. Differentiation between gram-positive and gram-negative wastewater bacteria was achieved after flow cytometric analysis. This study shows that the relative proportions of gram-positive and gram-negative bacterial cells identified by traditional microscopy and hexidium iodide staining were not significantly different. Dual staining of cells for Gram status and activity proved effective in analyzing mixtures of cultured bacteria and wastewater populations. Levels of highly active organisms at two wastewater treatment plants, both gram positive and gram negative, ranged from 1.5% in activated sludge flocs to 16% in the activated sludge fluid. Gram-positive organisms comprised <5% of the total bacterial numbers but accounted for 19 and 55% of the highly active organisms within flocs at the two plants. Assessment of Gram status and activity within activated sludge samples over a 4-day period showed significant differences over time. This method provides a rapid, quantitative measure of Gram status linked with in situ activity within wastewater systems.

Pharmacological Activation of Peroxisome Proliferator-Activated Receptor {Delta} Increases Sphingomyelin Synthase Activity in THP-1 Macrophage-Derived Foam Cell.

PubMed

Mou, Dongsheng; Yang, Hua; Qu, Changhua; Chen, Juan; Zhang, Chaogui

2016-08-01

Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors, which mediate glucose and lipid homeostasis by regulating the expression of a large number of transcription factors. Sphingomyelin synthase (SMS) is a key enzyme in the synthesis of sphingomyelin (SM), and its expression and activity have been reported to be associated with atherosclerosis (AS). Although there have been many functional PPAR and SMS studies on atherosclerosis in recent years, few have investigated the correlation between the activation of PPARδ and the activity of SMS. In his study, macrophage-induced foam cells were utilized to model important pathological changes that occur in AS. The influence of PPARδ agonism by GW501516 on SMS and its product molecule SM were measured. Results indicated that the activation of PPARδ was correlated in a positive manner with the activity of SMS2, and the content of SM was dose dependently increased by GW501516. Together, this study represents the first to suggest that PPARδ activation may be a potential risk of AS through enhancing activity of SMS2.

Rethinking food anticipatory activity in the activity-based anorexia rat model.

PubMed

Wu, Hemmings; van Kuyck, Kris; Tambuyzer, Tim; Luyten, Laura; Aerts, Jean-Marie; Nuttin, Bart

2014-01-29

When a rat is on a limited fixed-time food schedule with full access to a running wheel (activity-based anorexia model, ABA), its activity level will increase hours prior to the feeding period. This activity, called food-anticipatory activity (FAA), is a hypothesized parallel to the hyperactivity symptom in human anorexia nervosa. To investigate in depth the characteristics of FAA, we retrospectively analyzed the level of FAA and activities during other periods in ABA rats. To our surprise, rats with the most body weight loss have the lowest level of FAA, which contradicts the previously established link between FAA and the severity of ABA symptoms. On the contrary, our study shows that postprandial activities are more directly related to weight loss. We conclude that FAA alone may not be sufficient to reflect model severity, and activities during other periods may be of potential value in studies using ABA model.

The effect of physical activity homework on physical activity among college students.

PubMed

Claxton, David; Wells, Gayle M

2009-03-01

This study examined the effect of using physical activity homework on physical activity levels of college students. Students in randomly assigned sections of a university health course were assigned 30 minutes of physical activity homework 3 days a week or no homework for 12 weeks. Participants completed self-reports of physical activity before the homework intervention and again at the conclusion of the 12 weeks of physical activity homework. Participants in all course sections reported significant increases in the number of days per week of moderate and vigorous physical activity. Participants in homework sections additionally showed significant increases in the days they engaged in muscular strength/endurance training and activities to manage weight. Participants in sections without homework showed a significant increase in the number of days engaged in flexibility training. Comparison of gain scores showed statistically significant increases by the homework group in the days they participated in activities designed to manage weight. Physical activity homework was deemed to be an effective method of increasing college students' levels of physical activity.

Don't worry, be active: positive affect and habitual physical activity.

PubMed

Pasco, Julie A; Jacka, Felice N; Williams, Lana J; Brennan, Sharon L; Leslie, Eva; Berk, Michael

2011-12-01

The aim of ths study was to examine the association between habitual physical activity and positive and negative affect. This cross-sectional study included 276 women aged 20 +, from the Geelong Osteoporosis Study. Habitual physical activity and other lifestyle exposures were assessed by questionnaire, concurrent with anthropometric assessments. Physical activity was categorized as very active, moderately active or sedentary. Positive and negative affect scores were derived from the validated 20 item Positive and Negative Affect Schedule (PANAS) self-report and were categorized into tertiles. There was a pattern of lower positive affect scores for lower levels of physical activity. With very active as the reference category, the odds for having a positive affect score in the highest tertile were sequentially lower for those who were moderately active (OR = 0.53, 95%CI 0.28-1.01) and sedentary (OR = 0.28, 95%CI 0.10-0.75). Associations were sustained after adjusting for body mass index and polypharmacy (OR = 0.50, 95%CI 0.26-0.96 and OR = 0.25, 95%CI 0.09-0.72, respectively). These associations were not explained by age, negative affect score or other exposures. No association was detected between physical activity and negative affect scores. This study reports that higher positive affect scores, encompassing emotions such as interest, excitement, enthusiasm and alertness, are associated with higher levels of habitual physical activity. These observations warrant further investigations into possible mechanistic interplay between neurobiological and psychosocial factors that underpin this association.

Youth Physical Activity Resource Use and Activity Measured by Accelerometry

ERIC Educational Resources Information Center

Maslow, Andra L.; Colabianchi, Natalie

2011-01-01

Objectives: To examine whether use of physical activity resources (e.g., parks) was associated with daily physical activity measured by accelerometry. Methods: One hundred eleven adolescents completed a travel diary with concurrent accelerometry. The main exposure was self-reported use of a physical activity resource (none /1 resources). The main…

Predicting Activity Energy Expenditure Using the Actical[R] Activity Monitor

ERIC Educational Resources Information Center

Heil, Daniel P.

2006-01-01

This study developed algorithms for predicting activity energy expenditure (AEE) in children (n = 24) and adults (n = 24) from the Actical[R] activity monitor. Each participant performed 10 activities (supine resting, three sitting, three house cleaning, and three locomotion) while wearing monitors on the ankle, hip, and wrist; AEE was computed…

Factors influencing the purity of electronic grade phosphine delivered to MOCVD tools

NASA Astrophysics Data System (ADS)

Feng, Jun; Owens, Mitch; Raynor, Mark W.

2010-04-01

Increasing mobility of InP films with usage time of one PH 3 cylinder prompted an investigation into factors influencing the purity of delivered PH 3. The presence of hygroscopic H xPO y residues in a delivery system greatly increases the dry-down time compared to that of a clean system. Static delivery system tests show increasing H 2O concentration with time and twice the increase in PH 3 versus N 2 over 48 h indicating reaction of metal oxides in components with PH 3 to generate H 2O. Gas purity may also vary during cylinder usage. Depletion of a high-purity PH 3 cylinder shows consistently low gas phase H 2O levels before phase-break but increasing levels after phase-break, as the cylinder depressurizes. The results highlight the importance of using pure PH 3, employing rigorous cycle-purging procedures to prevent H xPO y contamination, switching out cylinders in good time and using purification technology to control H 2O.

Autoclave method for rapid preparation of bacterial PCR-template DNA.

PubMed

Simmon, Keith E; Steadman, Dewey D; Durkin, Sarah; Baldwin, Amy; Jeffrey, Wade H; Sheridan, Peter; Horton, Rene; Shields, Malcolm S

2004-02-01

An autoclave method for preparing bacterial DNA for PCR template is presented, it eliminates the use of detergents, organic solvents, and mechanical cellular disruption approaches, thereby significantly reducing processing time and costs while increasing reproducibility. Bacteria are lysed by rapid heating and depressurization in an autoclave. The lysate, cleared by microcentrifugation, was either used directly in the PCR reaction, or concentrated by ultrafiltration. This approach was compared with seven established methods of DNA template preparation from four bacterial sources which included boiling Triton X-100 and SDS, bead beating, lysozyme/proteinase K, and CTAB lysis method components. Bacteria examined were Enterococcus and Escherichia coli, a natural marine bacterial community and an Antarctic cyanobacterial-mat. DNAs were tested for their suitability as PCR templates by repetitive element random amplified polymorphic DNA (RAPD) and denaturing gradient gel electrophoresis (DGGE) analysis. The autoclave method produced PCR amplifiable template comparable or superior to the other methods, with greater reproducibility, much shorter processing time, and at a significantly lower cost.

Transport critical current measurement apparatus using liquid nitrogen cooled high-T(c) superconducting magnet with variable temperature insert.

PubMed

Nishijima, G; Kitaguchi, H; Tshuchiya, Y; Nishimura, T; Kato, T

2013-01-01

We have developed an apparatus to investigate transport critical current (I(c)) as a function of magnetic field and temperature using only liquid nitrogen. The apparatus consists of a (Bi,Pb)(2)Sr(2)Ca(2)Cu(3)O(10) (Bi-2223) superconducting magnet, an outer dewar, and a variable temperature insert (VTI). The magnet, which is operated in depressurized liquid nitrogen, generates magnetic field up to 1.26 T. The sample is also immersed in liquid nitrogen. The pressure in the VTI is controlled from 0.02 to 0.3 MPa, which corresponds to temperature ranging from 66 to 88 K. We have confirmed the long-term stable operation of the Bi-2223 magnet at 1 T. The temperature stability of the sample at high transport current was also demonstrated. The apparatus provides easy-operating I(c) measurement environment for a high-T(c) superconductor up to 500 A in magnetic fields up to 1 T and in temperatures ranging from 66 to 88 K.

Headward growth of chasmata by volatile outbursts, collapse, and drainage: Evidence from ganges chaos, Mars

USGS Publications Warehouse

Rodriguez, J.A.P.; Kargel, J.; Crown, D.A.; Bleamaster, L. F.; Tanaka, K.L.; Baker, V.; Miyamoto, H.; Dohm, J.M.; Sasaki, S.; Komatsu, G.

2006-01-01

The nature and significance of collapse processes in Capri, Eos, and Ganges Chasmata remain poorly understood. Using Ganges Chasma as a type locality, these chasmata are interpreted to be the result of clustering and assimilation of multiple chaotic terrains, which primarily formed by localized depressurization-induced or thermally-triggered dissociation of buried gas clathrate hydrates and explosive eruption of gas-saturated ground water. Such crustal destabilization could have been triggered by (1) deep fracture propagation from the Martian surface, (2) magmatic intrusions and associated heating and inflation-induced terrain fracturing, and/or (3) climatic thaw and thinning/weakening of the permafrost over the clathrate and gas-rich groundwater zones. Volume increases associated with release of gases contributed to the xpulsion of groundwater and fluidized sediments at the surface, thereby carving the higher outflow channels peripheral to the chasmata and the lower outflow channel floors of the chasmata and outflow channels. Copyright 2006 by the American Geophysical Union.

First experiment on liquid hydrogen transportation by ship inside Osaka bay

NASA Astrophysics Data System (ADS)

Maekawa, K.; Takeda, M.; Hamaura, T.; Suzuki, K.; Miyake, Y.; Matsuno, Y.; Fujikawa, S.; Kumakura, H.

2017-12-01

A project to import a large amount of liquid hydrogen (LH2) from Australia by a cargo carrier, which is equipped with two 1250 m3 tanks, is underway in Japan. It is important to understand sloshing and boil-off characteristics inside the LH2 tank during marine transportation. However, the LH2 sloshing and boil-off characteristics on the sea have not yet been clarified. First experiment on the LH2 transportation of 20 liter with magnesium diboride (MgB2) level sensors by the training ship “Fukae-maru”, which has 50 m long and 449 ton gross weight, was carried out successfully inside Osaka bay on February 2, 2017. In the experiment, synchronous measurements of liquid level, temperature, pressure, ship motions, and accelerations as well as the rapid depressurization test were done. The increase rate of the temperature and the pressure inside the LH2 tank were discussed under the rolling and the pitching conditions.

Designing an antibacterial acrylic resin using the cosolvent method -Effect of ethanol on the optical and mechanical properties of a cold-cure acrylic resin.

PubMed

Nezu, Takashi; Nagano-Takebe, Futami; Endo, Kazuhiko

2017-09-26

Antimicrobial cetylpyridinium chloride (CPC) has low miscibility with acrylic resin monomer but can be homogeneously mixed using ethanol as a cosolvent. This study investigated the effects of ethanol addition on the properties of a cold-cure acrylic resin. Ethanol was an excellent cosolvent for CPC and methyl methacrylate monomer (MMA), but the cured resin exhibited a strong change in coloration to yellow (ΔE* ab >8) and a drastically reduced bending strength (from 97 to 25 MPa) and elastic modulus (from 2.7 to 0.6 GPa) when equal volumes of ethanol and monomer were used together, possibly due to the solvation and deactivation of radicals by ethanol. However, these unfavorable effects diminished when the ethanol/MMA ratio was reduced to 0.25, and became smaller when each specimen was depressurized and excess ethanol was removed. Thus, it may be possible to develop a molecularly uniform antibacterial acrylic resin with acceptable color and strength using this simple technique.

Secondary migration and leakage of methane from a major tight-gas system

PubMed Central

Wood, James M.; Sanei, Hamed

2016-01-01

Tight-gas and shale-gas systems can undergo significant depressurization during basin uplift and erosion of overburden due primarily to the natural leakage of hydrocarbon fluids. To date, geologic factors governing hydrocarbon leakage from such systems are poorly documented and understood. Here we show, in a study of produced natural gas from 1,907 petroleum wells drilled into a Triassic tight-gas system in western Canada, that hydrocarbon fluid loss is focused along distinct curvilinear pathways controlled by stratigraphic trends with superior matrix permeability and likely also structural trends with enhanced fracture permeability. Natural gas along these pathways is preferentially enriched in methane because of selective secondary migration and phase separation processes. The leakage and secondary migration of thermogenic methane to surficial strata is part of an ongoing carbon cycle in which organic carbon in the deep sedimentary basin transforms into methane, and ultimately reaches the near-surface groundwater and atmosphere. PMID:27874012

Supercritical Carbon Dioxide-Assisted Decellularization of Aorta and Cornea.

PubMed

Guler, Selcan; Aslan, Bahar; Hosseinian, Pezhman; Aydin, Halil Murat

2017-09-01

Tissue engineering approaches utilize both natural and synthetic materials in the repair and regeneration processes. A naturally sourced material for this purpose is required to be free from any antigenic matter such as cells or cellular components. Decellularization of tissues may be achieved through chemical or physical removal agents. Supercritical carbon dioxide (sc-CO 2 ) has been used on the purpose of removing bioburden from tissues and offers an alternative to the traditionally used treatment methods. In addition to many advantages it offers with regard to the successful decellularization of tissues, it is known to have a sterilization effect. This study provides an insight into sc-CO 2 -assisted decellularization trials of corneal and aortic tissues. Results showed that high pressure of the fluid bursts the cells during the treatment and rapid depressurization was found to be effective in the removal of the cells from the tissues. sc-CO 2 decellularization offers significantly reduced treatment times, complete decellularization, and preserved extracellular matrix structure.

Simulations of nanocrystals under pressure: combining electronic enthalpy and linear-scaling density-functional theory.

PubMed

Corsini, Niccolò R C; Greco, Andrea; Hine, Nicholas D M; Molteni, Carla; Haynes, Peter D

2013-08-28

We present an implementation in a linear-scaling density-functional theory code of an electronic enthalpy method, which has been found to be natural and efficient for the ab initio calculation of finite systems under hydrostatic pressure. Based on a definition of the system volume as that enclosed within an electronic density isosurface [M. Cococcioni, F. Mauri, G. Ceder, and N. Marzari, Phys. Rev. Lett. 94, 145501 (2005)], it supports both geometry optimizations and molecular dynamics simulations. We introduce an approach for calibrating the parameters defining the volume in the context of geometry optimizations and discuss their significance. Results in good agreement with simulations using explicit solvents are obtained, validating our approach. Size-dependent pressure-induced structural transformations and variations in the energy gap of hydrogenated silicon nanocrystals are investigated, including one comparable in size to recent experiments. A detailed analysis of the polyamorphic transformations reveals three types of amorphous structures and their persistence on depressurization is assessed.

Simulations of nanocrystals under pressure: Combining electronic enthalpy and linear-scaling density-functional theory

NASA Astrophysics Data System (ADS)

Corsini, Niccolò R. C.; Greco, Andrea; Hine, Nicholas D. M.; Molteni, Carla; Haynes, Peter D.

2013-08-01

We present an implementation in a linear-scaling density-functional theory code of an electronic enthalpy method, which has been found to be natural and efficient for the ab initio calculation of finite systems under hydrostatic pressure. Based on a definition of the system volume as that enclosed within an electronic density isosurface [M. Cococcioni, F. Mauri, G. Ceder, and N. Marzari, Phys. Rev. Lett. 94, 145501 (2005)], 10.1103/PhysRevLett.94.145501, it supports both geometry optimizations and molecular dynamics simulations. We introduce an approach for calibrating the parameters defining the volume in the context of geometry optimizations and discuss their significance. Results in good agreement with simulations using explicit solvents are obtained, validating our approach. Size-dependent pressure-induced structural transformations and variations in the energy gap of hydrogenated silicon nanocrystals are investigated, including one comparable in size to recent experiments. A detailed analysis of the polyamorphic transformations reveals three types of amorphous structures and their persistence on depressurization is assessed.

Automation under suspicion--case flight AF-447 Air France.

PubMed

Martins, Edgard; Soares, Marcelo

2012-01-01

The probes allow the pilot to control the aircraft speed was essential to the balance of the flight. Opinions of experts who claim that "the design of the plane would have exercised a not inconsiderable role in the occurrence of a disaster." These messages revealed a series of important operating errors in a zone of turbulence, "making the plane uncontrollable, leading to a rapid depressurization device, according to these reports. A lawsuit in Toulouse and in Brazil aims to recognition of the liability of Air France and Airbus not insignificant role in the design and operation of the aircraft in the event of catastrophe. Opinions are taken from senior pilots that no commercial aviation training for certain situations abnormal flight that, if realized, could have influenced the pilots of the AF-447 to remove the plane's fatal dive show what experiments performed in simulators for military pilots, who are permanently subject to critical flight situations.

Autonomous healing materials based on epoxidized natural rubber and ethylene methacrylic acid ionomers

NASA Astrophysics Data System (ADS)

Arifur Rahman, Md; Penco, Maurizio; Peroni, Isabella; Ramorino, Giorgio; Janszen, Gerardus; Di Landro, Luca

2012-03-01

The development of autonomous healing material has an enormous scientific and technological interest. In this context, this research work deals with the investigation of autonomous healing behavior of epoxidized natural rubber (ENR) and its blends with ethylene methacrylic acid ionomers. The autonomous healing behavior of ENR and its blends containing two different ionomers [poly(ethylene-co-methacrylic acid sodium salt) (EMNa) and poly(ethylene-co-methacrylic acid zinc salt) (EMZn)] has been studied by ballistic puncture tests. Interestingly, EMNa/ENR blends exhibit complete healing just after the ballistic test but EMZn/ENR blends do not show full self-repairing. The healing efficiency has been evaluated by optical microscopy and a depressurized air-flow test. The healing mechanism has been investigated by characterizing thermal and mechanical properties of the blends. The chemical structure studied by FTIR and thermal analysis show that the ion content of ionomers and functionality of ENR has a significant influence on the self-healing behavior.

Dense CO2 as a Solute, Co-Solute or Co-Solvent in Particle Formation Processes: A Review

PubMed Central

Nunes, Ana V. M.; Duarte, Catarina M. M.

2011-01-01

The application of dense gases in particle formation processes has attracted great attention due to documented advantages over conventional technologies. In particular, the use of dense CO2 in the process has been subject of many works and explored in a variety of different techniques. This article presents a review of the current available techniques in use in particle formation processes, focusing exclusively on those employing dense CO2 as a solute, co-solute or co-solvent during the process, such as PGSS (Particles from gas-saturated solutions®), CPF (Concentrated Powder Form®), CPCSP (Continuous Powder Coating Spraying Process), CAN-BD (Carbon dioxide Assisted Nebulization with a Bubble Dryer®), SEA (Supercritical Enhanced Atomization), SAA (Supercritical Fluid-Assisted Atomization), PGSS-Drying and DELOS (Depressurization of an Expanded Liquid Organic Solution). Special emphasis is given to modifications introduced in the different techniques, as well as the limitations that have been overcome. PMID:28824121

Utilization of Sunlight into Methane Hydrate Production: Feasibility Study Based on Energy Balance Estimation

NASA Astrophysics Data System (ADS)

Shimada, J.; Shimada, M.; Tsunashima, K.; Aoyama, C.

2017-12-01

Methane hydrate is gaining remarkable attention as future natural gas resource. Collection procedures such as heating, depressurization, and chemical intrusion are being tested, but because of its high cost, they are still under development and not yet implemented. Cost reduction of the procedures cannot be expected as long as fossil fuel is used as power and heat source to extract methane gas from methane hydrate. In this regard, natural energy such as sunlight, wind, tidal, and wave powers should be implemented as energy resources as alternatives of fossil fuels. Using natural energy instead of fossil fuel will also help to prevent global warming. However, only a few proposals have been made regarding extraction methods to use clean natural energy effectively. In this study, authors will present a new extraction method using optical fibers to expose direct sunlight onto methane hydrate, and verify from various standpoints such as energy balance during extraction process and dependency of the environment.

CFD Modeling of Helium Pressurant Effects on Cryogenic Tank Pressure Rise Rates in Normal Gravity

NASA Technical Reports Server (NTRS)

Grayson, Gary; Lopez, Alfredo; Chandler, Frank; Hastings, Leon; Hedayat, Ali; Brethour, James

2007-01-01

A recently developed computational fluid dynamics modeling capability for cryogenic tanks is used to simulate both self-pressurization from external heating and also depressurization from thermodynamic vent operation. Axisymmetric models using a modified version of the commercially available FLOW-3D software are used to simulate actual physical tests. The models assume an incompressible liquid phase with density that is a function of temperature only. A fully compressible formulation is used for the ullage gas mixture that contains both condensable vapor and a noncondensable gas component. The tests, conducted at the NASA Marshall Space Flight Center, include both liquid hydrogen and nitrogen in tanks with ullage gas mixtures of each liquid's vapor and helium. Pressure and temperature predictions from the model are compared to sensor measurements from the tests and a good agreement is achieved. This further establishes the accuracy of the developed FLOW-3D based modeling approach for cryogenic systems.

Radon in Wisconsin.

PubMed

Weiffenbach, C; Anderson, H A

2000-11-01

Owners of about 15% to 20% of the homes in Wisconsin have tested their indoor air for the carcinogenic gas radon. Five percent to 10% of homes have year-average main-floor radon levels that exceed the US Environmental Protection Agency (EPA) exposure guideline, and they are found in most regions of the state. Attempting to retroactively seal foundations to keep radon from the ground out of a home is largely ineffective. However, a soil-depressurization radon mitigation system is highly effective for existing houses, and new homes can easily be built radon-resistant. As the number of homeowners obtaining needed repairs increases, significant lung cancer risk reduction is being achieved in a voluntary, non-regulatory setting. In coming years, as radon in community drinking water supplies becomes regulated under the federal 1996 Safe Drinking Water Act, the "multimedia" option of the act may result in additional attention to mitigation of radon in indoor air.

Fundamental challenges to methane recovery from gas hydrates

USGS Publications Warehouse

Servio, P.; Eaton, M.W.; Mahajan, D.; Winters, W.J.

2005-01-01

The fundamental challenges, the location, magnitude, and feasibility of recovery, which must be addressed to recover methane from dispersed hydrate sources, are presented. To induce dissociation of gas hydrate prior to methane recovery, two potential methods are typically considered. Because thermal stimulation requires a large energy input, it is less economically feasible than depressurization. The new data will allow the study of the effect of pressure, temperature, diffusion, porosity, tortuosity, composition of gas and water, and porous media on gas-hydrate production. These data also will allow one to improve existing models related to the stability and dissociation of sea floor hydrates. The reproducible kinetic data from the planned runs together with sediment properties will aid in developing a process to economically recover methane from a potential untapped hydrate source. The availability of plentiful methane will allow economical and large-scale production of methane-derived clean fuels to help avert future energy crises.

Technology Solutions Case Study: Predicting Envelope Leakage in Attached Dwellings

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

None

2013-11-01

The most common method of measuring air leakage is to perform single (or solo) blower door pressurization and/or depressurization test. In detached housing, the single blower door test measures leakage to the outside. In attached housing, however, this “solo” test method measures both air leakage to the outside and air leakage between adjacent units through common surfaces. In an attempt to create a simplified tool for predicting leakage to the outside, Building America team Consortium for Advanced Residential Buildings (CARB) performed a preliminary statistical analysis on blower door test results from 112 attached dwelling units in four apartment complexes. Althoughmore » the subject data set is limited in size and variety, the preliminary analyses suggest significant predictors are present and support the development of a predictive model. Further data collection is underway to create a more robust prediction tool for use across different construction types, climate zones, and unit configurations.« less

Transport critical current measurement apparatus using liquid nitrogen cooled high-Tc superconducting magnet with variable temperature insert

NASA Astrophysics Data System (ADS)

Nishijima, G.; Kitaguchi, H.; Tshuchiya, Y.; Nishimura, T.; Kato, T.

2013-01-01

We have developed an apparatus to investigate transport critical current (Ic) as a function of magnetic field and temperature using only liquid nitrogen. The apparatus consists of a (Bi,Pb)2Sr2Ca2Cu3O10 (Bi-2223) superconducting magnet, an outer dewar, and a variable temperature insert (VTI). The magnet, which is operated in depressurized liquid nitrogen, generates magnetic field up to 1.26 T. The sample is also immersed in liquid nitrogen. The pressure in the VTI is controlled from 0.02 to 0.3 MPa, which corresponds to temperature ranging from 66 to 88 K. We have confirmed the long-term stable operation of the Bi-2223 magnet at 1 T. The temperature stability of the sample at high transport current was also demonstrated. The apparatus provides easy-operating Ic measurement environment for a high-Tc superconductor up to 500 A in magnetic fields up to 1 T and in temperatures ranging from 66 to 88 K.

Structure-activity analysis of synthetic alpha-thrombin-receptor-activating peptides.

PubMed

Van Obberghen-Schilling, E; Rasmussen, U B; Vouret-Craviari, V; Lentes, K U; Pavirani, A; Pouysségur, J

1993-06-15

alpha-Thrombin stimulates G-protein-coupled effectors leading to secretion and aggregation in human platelets, and to a mitogenic response in CCL39 hamster fibroblasts. alpha-Thrombin receptors can be activated by synthetic peptides corresponding to the receptor sequence starting with serine-42, at the proposed cleavage site. We have previously determined that the agonist domain of receptor-activating peptides resides within the five N-terminal residues [Vouret-Craviari, Van Obberghen-Schilling, Rasmussen, Pavirani, Lecocq and Pouysségur (1992) Mol. Biol. Cell. 3, 95-102], although the 7-residue peptide (SFFLRNP) corresponding to the hamster alpha-thrombin receptor was 10 times more potent than the 5-residue peptide for activation of human platelets. In the present study we have analysed the role of individual amino acids in receptor activation by using a series of modified hexa- or hepta-peptides derived from the human alpha-thrombin-receptor sequence. Cellular events examined here include phospholipase C activation, adenylyl cyclase inhibition and DNA synthesis stimulation in non-transformed CCL39 fibroblasts and a tumorigenic variant of that line (A71 cells). Modification of the peptide sequence had similar functional consequence for each of the assays described, indicating that either a unique receptor or pharmacologically indistinguishable receptor subtypes activate distinct G-protein signalling pathways. Furthermore, we found that: (1) the N-terminal serine can be replaced by small or intermediately sized amino acids (+/- hydroxyl groups) without loss of activity. However, its replacement by an aromatic side-chain or omission of the N-terminal amino group severely reduces activity. (2) An aromatic side-chain on the penultimate N-terminal residue appears to play a critical role since phenylalanine in this position can be substituted by tyrosine without complete loss of activity whereas an alanine in its place is not tolerated. (3) Deletion of the first

Structure-activity analysis of synthetic alpha-thrombin-receptor-activating peptides.

PubMed Central

Van Obberghen-Schilling, E; Rasmussen, U B; Vouret-Craviari, V; Lentes, K U; Pavirani, A; Pouysségur, J

1993-01-01

alpha-Thrombin stimulates G-protein-coupled effectors leading to secretion and aggregation in human platelets, and to a mitogenic response in CCL39 hamster fibroblasts. alpha-Thrombin receptors can be activated by synthetic peptides corresponding to the receptor sequence starting with serine-42, at the proposed cleavage site. We have previously determined that the agonist domain of receptor-activating peptides resides within the five N-terminal residues [Vouret-Craviari, Van Obberghen-Schilling, Rasmussen, Pavirani, Lecocq and Pouysségur (1992) Mol. Biol. Cell. 3, 95-102], although the 7-residue peptide (SFFLRNP) corresponding to the hamster alpha-thrombin receptor was 10 times more potent than the 5-residue peptide for activation of human platelets. In the present study we have analysed the role of individual amino acids in receptor activation by using a series of modified hexa- or hepta-peptides derived from the human alpha-thrombin-receptor sequence. Cellular events examined here include phospholipase C activation, adenylyl cyclase inhibition and DNA synthesis stimulation in non-transformed CCL39 fibroblasts and a tumorigenic variant of that line (A71 cells). Modification of the peptide sequence had similar functional consequence for each of the assays described, indicating that either a unique receptor or pharmacologically indistinguishable receptor subtypes activate distinct G-protein signalling pathways. Furthermore, we found that: (1) the N-terminal serine can be replaced by small or intermediately sized amino acids (+/- hydroxyl groups) without loss of activity. However, its replacement by an aromatic side-chain or omission of the N-terminal amino group severely reduces activity. (2) An aromatic side-chain on the penultimate N-terminal residue appears to play a critical role since phenylalanine in this position can be substituted by tyrosine without complete loss of activity whereas an alanine in its place is not tolerated. (3) Deletion of the first

Transcription co-activator SAYP mediates the action of STAT activator

PubMed Central

Panov, Vladislav V.; Kuzmina, Julia L.; Doronin, Semen A.; Kopantseva, Marina R.; Nabirochkina, Elena N.; Georgieva, Sofia G.; Vorobyeva, Nadezhda E.; Shidlovskii, Yulii V.

2012-01-01

Jak/STAT is an important signaling pathway mediating multiple events in development. We describe participation of metazoan co-activator SAYP/PHF10 in this pathway downstream of STAT. The latter, via its activation domain, interacts with the conserved core of SAYP. STAT is associated with the SAYP-containing co-activator complex BTFly and recruits BTFly onto genes. SAYP is necessary for stimulating STAT-driven transcription of numerous genes. Mutation of SAYP leads to maldevelopments similar to those observed in STAT mutants. Thus, SAYP is a novel co-activator mediating the action of STAT. PMID:22123744

Transcription co-activator SAYP mediates the action of STAT activator.

PubMed

Panov, Vladislav V; Kuzmina, Julia L; Doronin, Semen A; Kopantseva, Marina R; Nabirochkina, Elena N; Georgieva, Sofia G; Vorobyeva, Nadezhda E; Shidlovskii, Yulii V

2012-03-01

Jak/STAT is an important signaling pathway mediating multiple events in development. We describe participation of metazoan co-activator SAYP/PHF10 in this pathway downstream of STAT. The latter, via its activation domain, interacts with the conserved core of SAYP. STAT is associated with the SAYP-containing co-activator complex BTFly and recruits BTFly onto genes. SAYP is necessary for stimulating STAT-driven transcription of numerous genes. Mutation of SAYP leads to maldevelopments similar to those observed in STAT mutants. Thus, SAYP is a novel co-activator mediating the action of STAT.

Physical Activity Assessment

Cancer.gov

Current evidence convincingly indicates that physical activity reduces the risk of colon and breast cancer. Physical activity may also reduce risk of prostate cancer. Scientists are also evaluating potential relationships between physical activity and other cancers.

Integration of active pauses and pattern of muscular activity during computer work.

PubMed

St-Onge, Nancy; Samani, Afshin; Madeleine, Pascal

2017-09-01

Submaximal isometric muscle contractions have been reported to increase variability of muscle activation during computer work; however, other types of active contractions may be more beneficial. Our objective was to determine which type of active pause vs. rest is more efficient in changing muscle activity pattern during a computer task. Asymptomatic regular computer users performed a standardised 20-min computer task four times, integrating a different type of pause: sub-maximal isometric contraction, dynamic contraction, postural exercise and rest. Surface electromyographic (SEMG) activity was recorded bilaterally from five neck/shoulder muscles. Root-mean-square decreased with isometric pauses in the cervical paraspinals, upper trapezius and middle trapezius, whereas it increased with rest. Variability in the pattern of muscular activity was not affected by any type of pause. Overall, no detrimental effects on the level of SEMG during active pauses were found suggesting that they could be implemented without a cost on activation level or variability. Practitioner Summary: We aimed to determine which type of active pause vs. rest is best in changing muscle activity pattern during a computer task. Asymptomatic computer users performed a standardised computer task integrating different types of pauses. Muscle activation decreased with isometric pauses in neck/shoulder muscles, suggesting their implementation during computer work.

syk kinase activation by a src kinase-initiated activation loop phosphorylation chain reaction

PubMed Central

El-Hillal, O.; Kurosaki, T.; Yamamura, H.; Kinet, J.-P.; Scharenberg, A. M.

1997-01-01

Activation of the syk tyrosine kinase occurs almost immediately following engagement of many types of antigen receptors, including Fc receptors, but the mechanism through which syk is activated is currently unclear. Here we demonstrate that Fc receptor-induced syk activation occurs as the result of phosphorylation of the syk activation loop by both src family kinases and other molecules of activated syk, suggesting that syk activation occurs as the result of a src kinase-initiated activation loop phosphorylation chain reaction. This type of activation mechanism predicts that syk activation would exhibit exponential kinetics, providing a potential explanation for its rapid and robust activation by even weak antigen receptor stimuli. We propose that a similar mechanism may be responsible for generating rapid activation of other cytoplasmic tyrosine kinases, such as those of the Bruton tyrosine kinase/tec family, as well. PMID:9050880

Activity of antimicrobial peptide mimetics in the oral cavity: II. Activity against periopathogenic biofilms and anti-inflammatory activity

PubMed Central

Hua, J; Scott, R.W.; Diamond, G

2011-01-01

Whereas periodontal disease is ultimately of bacterial etiology, from multispecies biofilms of gram-negative anaerobic microorganisms, much of the deleterious effects are caused by the resultant epithelial inflammatory response. Hence, development of a treatment that combines anti-biofilm antibiotic activity with anti-inflammatory activity would be of great utility. Antimicrobial peptides (AMPs) such as defensins are naturally occurring peptides that exhibit broad-spectrum activity as well as a variety of immunomodulatory activities. Furthermore, bacteria do not readily develop resistance to these agents. However, clinical studies have suggested that they do not represent optimal candidates for exogenous therapeutic agents. Small-molecule mimetics of these AMPs exhibit similar activities to the parent peptides, in addition to having low toxicity, high stability and low cost. To determine whether AMP mimetics have the potential for treatment of periodontal disease, we examined the activity of one mimetic, mPE, against biofilm cultures of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. Metabolic assays as well as culture and biomass measurement assays demonstrated that mPE exhibits potent activity against biofilm cultures of both species. Furthermore, as little as 2 µg ml−1 mPE was sufficient to inhibit interleukin-1β-induced secretion of interleukin-8 in both gingival epithelial cells and THP-1 cells. This anti-inflammatory activity is associated with a reduction in activation of nuclear factor-κB, suggesting that mPE can act both as an anti-biofilm agent in an anaerobic environment and as an anti-inflammatory agent in infected tissues. PMID:21040516

Recess, Extracurricular Activities, and Active Classrooms: Means for Increasing Elementary School Students' Physical Activity

ERIC Educational Resources Information Center

Kahan, David

2008-01-01

Physical education is traditionally thought of as the primary means of providing physical activity in the school environment. However, only 17 to 22 percent of elementary schools offer daily physical education with a cumulative duration of about 85 to 98 minutes per week. Based on pedometer counts of weekday physical activity, lunch recess and…

Glycogen synthase kinase 3β promotes liver innate immune activation by restraining AMP-activated protein kinase activation.

PubMed

Zhou, Haoming; Wang, Han; Ni, Ming; Yue, Shi; Xia, Yongxiang; Busuttil, Ronald W; Kupiec-Weglinski, Jerzy W; Lu, Ling; Wang, Xuehao; Zhai, Yuan

2018-07-01

Glycogen synthase kinase 3β (Gsk3β [Gsk3b]) is a ubiquitously expressed kinase with distinctive functions in different types of cells. Although its roles in regulating innate immune activation and ischaemia and reperfusion injuries (IRIs) have been well documented, the underlying mechanisms remain ambiguous, in part because of the lack of cell-specific tools in vivo. We created a myeloid-specific Gsk3b knockout (KO) strain to study the function of Gsk3β in macrophages in a murine liver partial warm ischaemia model. Compared with controls, myeloid Gsk3b KO mice were protected from IRI, with diminished proinflammatory but enhanced anti-inflammatory immune responses in livers. In bone marrow-derived macrophages, Gsk3β deficiency resulted in an early reduction of Tnf gene transcription but sustained increase of Il10 gene transcription on Toll-like receptor 4 stimulation in vitro. These effects were associated with enhanced AMP-activated protein kinase (AMPK) activation, which led to an accelerated and higher level of induction of the novel innate immune negative regulator small heterodimer partner (SHP [Nr0b2]). The regulatory function of Gsk3β on AMPK activation and SHP induction was confirmed in wild-type bone marrow-derived macrophages with a Gsk3 inhibitor. Furthermore, we found that this immune regulatory mechanism was independent of Gsk3β Ser9 phosphorylation and the phosphoinositide 3-kinase-Akt signalling pathway. In vivo, myeloid Gsk3β deficiency facilitated SHP upregulation by ischaemia-reperfusion in liver macrophages. Treatment of Gsk3b KO mice with either AMPK inhibitor or SHP small interfering RNA before the onset of liver ischaemia restored liver proinflammatory immune activation and IRI in these otherwise protected hosts. Additionally, pharmacological activation of AMPK protected wild-type mice from liver IRI, with reduced proinflammatory immune activation. Inhibition of the AMPK-SHP pathway by liver ischaemia was demonstrated in tumour resection

Antioxidative activities and active compounds of extracts from Catalpa plant leaves.

PubMed

Xu, Hongyu; Hu, Gege; Dong, Juane; Wei, Qin; Shao, Hongbo; Lei, Ming

2014-01-01

In order to screen the Catalpa plant with high antioxidant activity and confirm the corresponding active fractions from Catalpa ovata G. Don, C. fargesii Bur., and C. bungei C. A. Mey., total flavonoid contents and antioxidant activities of the extracts/fractions of Catalpa plant leaves were determined. The determined total flavonoid content and antioxidant activity were used as assessment criteria. Those compounds with antioxidant activity were isolated with silica gel column chromatography and ODS column chromatography. Our results showed that the total flavonoid content in C. bungei C. A. Mey. (30.07 mg/g · DW) was the highest, followed by those in C. fargesii Bur. (25.55 mg/g · DW) and C. ovata G. Don (24.96 mg/g · DW). According to the determination results of total flavonoid content and antioxidant activity in 3 clones of leaves of C. bungei C. A. Mey., the total flavonoid content and antioxidant activity in crude extracts from C. bungei C. A. Mey. 6 (CA6) leaves were the highest. Moreover, the results showed that the total flavonoid content and antioxidant activities of ethyl acetate (EA) fraction in ethanol crude extracts in CA6 leaves were the highest, followed by n-butanol, petroleum ether (PE), and water fractions. Two flavonoid compounds with antioxidant activity were firstly isolated based on EA fraction. The two compounds were luteolin (1) and apigenin (2), respectively.

Activated AMPK inhibits PPAR-{alpha} and PPAR-{gamma} transcriptional activity in hepatoma cells.

PubMed

Sozio, Margaret S; Lu, Changyue; Zeng, Yan; Liangpunsakul, Suthat; Crabb, David W

2011-10-01

AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor-α (PPAR-α) are critical regulators of short-term and long-term fatty acid oxidation, respectively. We examined whether the activities of these molecules were coordinately regulated. H4IIEC3 cells were transfected with PPAR-α and PPAR-γ expression plasmids and a peroxisome-proliferator-response element (PPRE) luciferase reporter plasmid. The cells were treated with PPAR agonists (WY-14,643 and rosiglitazone), AMPK activators 5-aminoimidazole-4-carboxamide riboside (AICAR) and metformin, and the AMPK inhibitor compound C. Both AICAR and metformin decreased basal and WY-14,643-stimulated PPAR-α activity; compound C increased agonist-stimulated reporter activity and partially reversed the effect of the AMPK activators. Similar effects on PPAR-γ were seen, with both AICAR and metformin inhibiting PPRE reporter activity. Compound C increased basal PPAR-γ activity and rosiglitazone-stimulated activity. In contrast, retinoic acid receptor-α (RAR-α), another nuclear receptor that dimerizes with retinoid X receptor (RXR), was largely unaffected by the AMPK activators. Compound C modestly increased AM580 (an RAR agonist)-stimulated activity. The AMPK activators did not affect PPAR-α binding to DNA, and there was no consistent correlation between effects of the AMPK activators and inhibitor on PPAR and the nuclear localization of AMPK-α subunits. Expression of either a constitutively active or dominant negative AMPK-α inhibited basal and WY-14,643-stimulated PPAR-α activity and basal and rosiglitazone-stimulated PPAR-γ activity. We concluded that the AMPK activators AICAR and metformin inhibited transcriptional activities of PPAR-α and PPAR-γ, whereas inhibition of AMPK with compound C activated both PPARs. The effects of AMPK do not appear to be mediated through effects on RXR or on PPAR/RXR binding to DNA. These effects are independent of kinase activity and instead appear to

Get Active Orlando: changing the built environment to increase physical activity.

PubMed

McCreedy, Malisa; Leslie, Jill G

2009-12-01

Active Living by Design's Get Active Orlando partnership (GAO) focused on downtown Orlando's Community Redevelopment Area, including the Parramore Heritage District, home to many low-income and ethnically diverse residents, including many seniors. The area had undergone substantial development, and GAO aimed to incorporate active living considerations into the city's changing landscape. Get Active Orlando conducted a baseline survey of all streets, sidewalks, and bicycle lanes in the project area and identified a sequence of plans and policies in which to incorporate changes identified in the assessment. To create more immediate opportunities for active living, the partnership initiated a senior walking program, a bicycle refurbishment and giveaway program, and community bicycle-riding events, and led a social-marketing campaign that emphasized simple lifestyle changes. Get Active Orlando influenced adoption of public policies supporting active living in Orlando, including the Downtown Transportation Plan, Streetscape Guidelines, Design Standards Review Checklist, and growth management policies. Establishment of the Mayor's Advisory Council on Active Living is testament to the heightened significance of active living in Orlando. Initial assessment data served as a strong platform for policy change. Creating connections across disciplines including land-use planning, transportation, public health, and economic development allowed GAO to secure substantial policy change to influence design of the built environment. Engaging community members, including youth, as leaders was an important factor in program success. The physical environment in Orlando's Community Redevelopment Area is beginning to change as a reflection of a new policy framework designed to support active living.

Curcumin Suppresses T Cell Activation by Blocking Ca2+ Mobilization and Nuclear Factor of Activated T Cells (NFAT) Activation

PubMed Central

Kliem, Christian; Merling, Anette; Giaisi, Marco; Köhler, Rebecca; Krammer, Peter H.; Li-Weber, Min

2012-01-01

Curcumin is the active ingredient of the spice turmeric and has been shown to have a number of pharmacologic and therapeutic activities including antioxidant, anti-microbial, anti-inflammatory, and anti-carcinogenic properties. The anti-inflammatory effects of curcumin have primarily been attributed to its inhibitory effect on NF-κB activity due to redox regulation. In this study, we show that curcumin is an immunosuppressive phytochemical that blocks T cell-activation-induced Ca2+ mobilization with IC50 = ∼12.5 μm and thereby prevents NFAT activation and NFAT-regulated cytokine expression. This finding provides a new mechanism for curcumin-mediated anti-inflammatory and immunosuppressive function. We also show that curcumin can synergize with CsA to enhance immunosuppressive activity because of different inhibitory mechanisms. Furthermore, because Ca2+ is also the secondary messenger crucial for the TCR-induced NF-κB signaling pathway, our finding also provides another mechanism by which curcumin suppresses NF-κB activation. PMID:22303019

Homogeneous near surface activity distribution by double energy activation for TLA

NASA Astrophysics Data System (ADS)

Takács, S.; Ditrói, F.; Tárkányi, F.

2007-10-01

Thin layer activation (TLA) is a versatile tool for activating thin surface layers in order to study real-time the surface loss by wear, corrosion or erosion processes of the activated parts, without disassembling or stopping running mechanical structures or equipment. The research problem is the determination of the irradiation parameters to produce point-like or large area optimal activity-depth distribution in the sample. Different activity-depth profiles can be produced depending on the type of the investigated material and the nuclear reaction used. To produce activity that is independent of the depth up to a certain depth is desirable when the material removed from the surface by wear, corrosion or erosion can be collected completely. By applying dual energy irradiation the thickness of this quasi-constant activity layer can be increased or the deviation of the activity distribution from a constant value can be minimized. In the main, parts made of metals and alloys are suitable for direct activation, but by using secondary particle implantation the wear of other materials can also be studied in a surface range a few micrometers thick. In most practical cases activation of a point-like spot (several mm2) is enough to monitor the wear, corrosion or erosion, but for special problems relatively large surfaces areas of complicated spatial geometry need to be activated uniformly. Two ways are available for fulfilling this task, (1) production of large area beam spot or scanning the beam over the surface in question from the accelerator side, or (2) a programmed 3D movement of the sample from the target side. Taking into account the large variability of tasks occurring in practice, the latter method was chosen as the routine solution in our cyclotron laboratory.

Activation of Neurotensin Receptor Type 1 Attenuates Locomotor Activity

PubMed Central

Vadnie, Chelsea A.; Hinton, David J.; Choi, Sun; Choi, YuBin; Ruby, Christina L.; Oliveros, Alfredo; Prieto, Miguel L.; Park, Jun Hyun; Choi, Doo-Sup

2014-01-01

Intracerebroventricular administration of neurotensin (NT) suppresses locomotor activity. However, the brain regions that mediate the locomotor depressant effect of NT and receptor subtype-specific mechanisms involved are unclear. Using a brain-penetrating, selective NT receptor type 1 (NTS1) agonist PD149163, we investigated the effect of systemic and brain region-specific NTS1 activation on locomotor activity. Systemic administration of PD149163 attenuated the locomotor activity of C57BL/6J mice both in a novel environment and in their homecage. However, mice developed tolerance to the hypolocomotor effect of PD149163 (0.1 mg/kg, i.p.). Since NTS1 is known to modulate dopaminergic signaling, we examined whether PD149163 blocks dopamine receptor-mediated hyperactivity. Pretreatment with PD149163 (0.1 or 0.05 mg/kg, i.p.) inhibited D2R agonist bromocriptine (8 mg/kg, i.p.)-mediated hyperactivity. D1R agonist SKF81297 (8 mg/kg, i.p.)-induced hyperlocomotion was only inhibited by 0.1 mg/kg of PD149163. Since the nucleus accumbens (NAc) and medial prefrontal cortex (mPFC) have been implicated in the behavioral effects of NT, we examined whether microinjection of PD149163 into these regions reduces locomotion. Microinjection of PD149163 (2 pmol) into the NAc, but not the mPFC suppressed locomotor activity. In summary, our results indicate that systemic and intra-NAc activation of NTS1 is sufficient to reduce locomotion and NTS1 activation inhibits D2R-mediated hyperactivity. Our study will be helpful to identify pharmacological factors and a possible therapeutic window for NTS1-targeted therapies for movement disorders. PMID:24929110

Mars Surface Tunnel Element Concept

NASA Technical Reports Server (NTRS)

Rucker, Michelle A.

2016-01-01

How crews get into or out of their ascent vehicle has profound implications for Mars surface architecture. Extravehicular Activity (EVA) hatches and Airlocks have the benefit of relatively low mass and high Technology Readiness Level (TRL), but waste consumables with a volume depressurization for every ingress/egress. Perhaps the biggest drawback to EVA hatches or Airlocks is that they make it difficult to keep Martian dust from being tracked back into the ascent vehicle, in violation of planetary protection protocols. Suit ports offer the promise of dust mitigation by keeping dusty suits outside the cabin, but require significant cabin real estate, are relatively high mass, and current operational concepts still require an EVA hatch to get the suits outside for the first EVA, and back inside after the final EVA. This is primarily because current designs don't provide enough structural support to protect the suits from ascent/descent loads or potential thruster plume impingement. For architectures involving more than one surface element-such as an ascent vehicle and a rover or surface habitat-a retractable tunnel is an attractive option. By pushing spacesuit don/doff and EVA operations to an element that remains on the surface, ascended vehicle mass and dust can be minimized. What's more, retractable tunnels provide operational flexibility by allowing surface assets to be re-configured or built up over time. Retractable tunnel functional requirements and design concepts being developed as part of the National Aeronautics and Space Administration's (NASA) Evolvable Mars Campaign (EMC) work will add a new ingress/egress option to the surface architecture trade space.

Stimuli-Responsive/Rheoreversible Hydraulic Fracturing Fluids as a Greener Alternative to Support Geothermal and Fossil Energy Production

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

Jung, Hun Bok; Carroll, KC; Kabilan, Senthil

2015-01-01

Cost-effective yet safe creation of high-permeability reservoirs within deep bedrock is the primary challenge for the viability of enhanced geothermal systems (EGS) and unconventional oil/gas recovery. Although fracturing fluids are commonly used for oil/gas, standard fracturing methods are not developed or proven for EGS temperatures and pressures. Furthermore, the environmental impacts of currently used fracturing methods are only recently being determined. Widespread concerns about the environmental contamination have resulted in a number of regulations for fracturing fluids advocating for greener fracturing processes. To enable EGS feasibility and lessen environmental impact of reservoir stimulation, an environmentally benign, CO2-activated, rheoreversible fracturing fluidmore » that enhances permeability through fracturing (at significantly lower effective stress than standard fracturing fluids) due to in situ volume expansion and gel formation is investigated herein. The chemical mechanism, stability, phase-change behavior, and rheology for a novel polyallylamine (PAA)-CO2 fracturing fluid was characterized at EGS temperatures and pressures. Hydrogel is formed upon reaction with CO2 and this process is reversible (via CO2 depressurization or solubilizing with a mild acid) allowing removal from the formation and recycling, decreasing environmental impact. Rock obtained from the Coso geothermal field was fractured in laboratory experiments under various EGS temperatures and pressures with comparison to standard fracturing fluids, and the fractures were characterized with imaging, permeability measurement, and flow modeling. This novel fracturing fluid and process may vastly reduce water usage and the environmental impact of fracturing practices and effectively make EGS production and unconventional oil/gas exploitation cost-effective and cleaner.« less

A multiscale approach to determine hydraulic conductivity in thick claystone aquitards using field, laboratory, and numerical modeling methods

NASA Astrophysics Data System (ADS)

Smith, L. A.; Barbour, S. L.; Hendry, M. J.; Novakowski, K.; van der Kamp, G.

2016-07-01

Characterizing the hydraulic conductivity (K) of aquitards is difficult due to technical and logistical difficulties associated with field-based methods as well as the cost and challenge of collecting representative and competent core samples for laboratory analysis. The objective of this study was to produce a multiscale comparison of vertical and horizontal hydraulic conductivity (Kv and Kh, respectively) of a regionally extensive Cretaceous clay-rich aquitard in southern Saskatchewan. Ten vibrating wire pressure transducers were lowered into place at depths between 25 and 325 m, then the annular was space was filled with a cement-bentonite grout. The in situ Kh was estimated at the location of each transducer by simulating the early-time pore pressure measurements following setting of the grout using a 2-D axisymmetric, finite element, numerical model. Core samples were collected during drilling for conventional laboratory testing for Kv to compare with the transducer-determined in situ Kh. Results highlight the importance of scale and consideration of the presence of possible secondary features (e.g., fractures) in the aquitard. The proximity of the transducers to an active potash mine (˜1 km) where depressurization of an underlying aquifer resulted in drawdown through the aquitard provided a unique opportunity to model the current hydraulic head profile using both the Kh and Kv estimates. Results indicate that the transducer-determined Kh estimates would allow for the development of the current hydraulic head distribution, and that simulating the pore pressure recovery can be used to estimate moderately low in situ Kh (<10-11 m s-1).

Volcano dome dynamics at Mount St. Helens: Deformation and intermittent subsidence monitored by seismicity and camera imagery pixel offsets

USGS Publications Warehouse

Salzer, Jacqueline T.; Thelen, Weston A.; James, Mike R.; Walter, Thomas R.; Moran, Seth C.; Denlinger, Roger P.

2016-01-01

The surface deformation field measured at volcanic domes provides insights into the effects of magmatic processes, gravity- and gas-driven processes, and the development and distribution of internal dome structures. Here we study short-term dome deformation associated with earthquakes at Mount St. Helens, recorded by a permanent optical camera and seismic monitoring network. We use Digital Image Correlation (DIC) to compute the displacement field between successive images and compare the results to the occurrence and characteristics of seismic events during a 6 week period of dome growth in 2006. The results reveal that dome growth at Mount St. Helens was repeatedly interrupted by short-term meter-scale downward displacements at the dome surface, which were associated in time with low-frequency, large-magnitude seismic events followed by a tremor-like signal. The tremor was only recorded by the seismic stations closest to the dome. We find a correlation between the magnitudes of the camera-derived displacements and the spectral amplitudes of the associated tremor. We use the DIC results from two cameras and a high-resolution topographic model to derive full 3-D displacement maps, which reveals internal dome structures and the effect of the seismic activity on daily surface velocities. We postulate that the tremor is recording the gravity-driven response of the upper dome due to mechanical collapse or depressurization and fault-controlled slumping. Our results highlight the different scales and structural expressions during growth and disintegration of lava domes and the relationships between seismic and deformation signals.

Parent and child physical activity and sedentary time: do active parents foster active children?

PubMed

Jago, Russell; Fox, Kenneth R; Page, Angie S; Brockman, Rowan; Thompson, Janice L

2010-04-15

Physical activity has many positive effects on children's health while TV viewing has been associated with adverse health outcomes. Many children do not meet physical activity recommendations and exceed TV viewing guidelines. Parents are likely to be an important influence on their children's behaviour. There is an absence of information about the associations between parents' and children's physical activity and TV viewing. Year 6 children and their parent were recruited from 40 primary schools. Results are presented for the 340 parent-child dyads with accelerometer data that met a > or = 3 day inclusion criteria and the 431 parent-child dyads with complete self-reported TV viewing. Over 80% of the dyads with valid TV viewing data included mothers and their child. Mean minutes of moderate to vigorous physical activity (MVPA), minutes of sedentary time per day and counts per minute were assessed by accelerometer. Self-reported hours of TV viewing were coded into 3 groups (< 2 hours per day, 2-4 hours per day and >4 hours per day. Linear and multi-nominal regression models were run by child gender to examine parent-child associations. In linear regression models there was an association for the overall sedentary time of girls and their parents (t = 2.04. p = .020) but there was no association between girls' and parents' physical activity. There were no associations between parents' and boys' sedentary or physical activity time. For girls, the risk of watching more than 4 hours of TV per day, (reference = 2 hours of TV per day), was 3.67 times higher if the girl's parent watched 2-4 hours of TV per day (p = 0.037). For boys, the risk of watching more than 4 hours of TV per day, was 10.47 times higher if the boy's parent watched more than 4 hours of TV per day (p = 0.038). There are associations in the sedentary time of parents and daughters. Higher parental TV viewing was associated with an increased risk of high levels of TV viewing for both boys and girls. There

Shear wave anisotropy in northwestern South America and its link to the Caribbean and Nazca subduction geodynamics

NASA Astrophysics Data System (ADS)

Idárraga-García, J.; Kendall, J.-M.; Vargas, C. A.

2016-09-01

To investigate the subduction dynamics in northwestern South America, we measured SKS and slab-related local S splitting at 38 seismic stations. Comparison between the delay times of both phases shows that most of the SKS splitting is due to entrained mantle flow beneath the subducting Nazca and Caribbean slabs. On the other hand, the fast polarizations of local S-waves are consistently aligned with regional faults, which implies the existence of a lithosphere-confined anisotropy in the overriding plate, and that the mantle wedge is not contributing significantly to the splitting. Also, we identified a clear change in SKS fast directions at the trace of the Caldas Tear (˜5°N), which represents a variation in the subduction style. To the north of ˜5°N, fast directions are consistently parallel to the flat subduction of the Caribbean plate-Panama arc beneath South America, while to the south fast polarizations are subparallel to the Nazca-South America subduction direction. A new change in the SKS splitting pattern is detected at ˜2.8°N, which is related to another variation in the subduction geometry marked by the presence of a lithosphere-scale tearing structure, named here as Malpelo Tear; in this region, NE-SW-oriented SKS fast directions are consistent with the general dip direction of the underthrusting of the Carnegie Ridge beneath South America. Further inland, this NE-SW-trending mantle flow continues beneath the Eastern Cordillera of Colombia and Merida Andes of Venezuela. Finally, our results suggest that the subslab mantle flow in northwestern South America is strongly controlled by the presence of lithospheric tearing structures.

Pronounced zonation of seismic anisotropy in the Western Hellenic subduction zone and its geodynamic significance

NASA Astrophysics Data System (ADS)

Olive, Jean-Arthur; Pearce, Frederick; Rondenay, Stéphane; Behn, Mark D.

2014-04-01

Many subduction zones exhibit significant retrograde motion of their arc and trench. The observation of fast shear-wave velocities parallel to the trench in such settings has been inferred to represent trench-parallel mantle flow beneath a retreating slab. Here, we investigate this process by measuring seismic anisotropy in the shallow Aegean mantle. We carry out shear-wave splitting analysis on a dense array of seismometers across the Western Hellenic Subduction Zone, and find a pronounced zonation of anisotropy at the scale of the subduction zone. Fast SKS splitting directions subparallel to the trench-retreat direction dominate the region nearest to the trench. Fast splitting directions abruptly transition to trench-parallel above the corner of the mantle wedge, and rotate back to trench-normal over the back-arc. We argue that the trench-normal anisotropy near the trench is explained by entrainment of an asthenospheric layer beneath the shallow-dipping portion of the slab. Toward the volcanic arc this signature is overprinted by trench-parallel anisotropy in the mantle wedge, likely caused by a layer of strained serpentine immediately above the slab. Arcward steepening of the slab and horizontal divergence of mantle flow due to rollback may generate an additional component of sub-slab trench-parallel anisotropy in this region. Poloidal flow above the retreating slab is likely the dominant source of back-arc trench-normal anisotropy. We hypothesize that trench-normal anisotropy associated with significant entrainment of the asthenospheric mantle near the trench may be widespread but only observable at shallow-dipping subduction zones where stations nearest the trench do not overlie the mantle wedge.

Slab anisotropy from subduction zone guided waves in Taiwan

NASA Astrophysics Data System (ADS)

Chen, K. H.; Tseng, Y. L.; Hu, J. C.

2014-12-01

Frozen-in anisotropic structure in the oceanic lithosphere and faulting/hydration in the upper layer of the slab are expected to play an important role in anisotropic signature of the subducted slab. Over the past several decades, despite the advances in characterizing anisotropy using shear wave splitting method and its developments, the character of slab anisotropy remains poorly understood. In this study we investigate the slab anisotropy using subduction zone guided waves characterized by long path length in the slab. In the southernmost Ryukyu subduction zone, seismic waves from events deeper than 100 km offshore northern Taiwan reveal wave guide behavior: (1) a low-frequency (< 1 Hz) first arrival recognized on vertical and radial components but not transverse component (2) large, sustained high-frequency (3-10 Hz) signal in P and S wave trains. The depth dependent high-frequency content (3-10Hz) confirms the association with a waveguide effect in the subducting slab rather than localized site amplification effects. Using the selected subduction zone guided wave events, we further analyzed the shear wave splitting for intermediate-depth earthquakes in different frequency bands, to provide the statistically meaningful shear wave splitting parameters. We determine shear wave splitting parameters from the 34 PSP guided events that are deeper than 100 km with ray path traveling along the subducted slab. From shear wave splitting analysis, the slab and crust effects reveal consistent polarization pattern of fast directions of EN-WS and delay time of 0.13 - 0.27 sec. This implies that slab anisotropy is stronger than the crust effect (<0.1 s) but weaker than the mantle wedge and sub-slab mantle effect (0.3-1.3 s) in Taiwan.

Active Play: Exploring the Influences on Children's School Playground Activities

ERIC Educational Resources Information Center

Hyndman, Brendon; Benson, Amanda; Telford, Amanda

2016-01-01

Because children spend so much of their time in schools, their playgrounds offer a good setting for promoting active play in young lives. Teachers, instead of considering active play a taxing demand on their busy day, have begun to develop an informal curriculum for it. The authors review the research on children's active play and explores its…

4-Aminoquinolines Active against Chloroquine-Resistant Plasmodium falciparum: Basis of Antiparasite Activity and Quantitative Structure-Activity Relationship Analyses▿

PubMed Central

Hocart, Simon J.; Liu, Huayin; Deng, Haiyan; De, Dibyendu; Krogstad, Frances M.; Krogstad, Donald J.

2011-01-01

Chloroquine (CQ) is a safe and economical 4-aminoquinoline (AQ) antimalarial. However, its value has been severely compromised by the increasing prevalence of CQ resistance. This study examined 108 AQs, including 68 newly synthesized compounds. Of these 108 AQs, 32 (30%) were active only against CQ-susceptible Plasmodium falciparum strains and 59 (55%) were active against both CQ-susceptible and CQ-resistant P. falciparum strains (50% inhibitory concentrations [IC50s], ≤25 nM). All AQs active against both CQ-susceptible and CQ-resistant P. falciparum strains shared four structural features: (i) an AQ ring without alkyl substitution, (ii) a halogen at position 7 (Cl, Br, or I but not F), (iii) a protonatable nitrogen at position 1, and (iv) a second protonatable nitrogen at the end of the side chain distal from the point of attachment to the AQ ring via the nitrogen at position 4. For activity against CQ-resistant parasites, side chain lengths of ≤3 or ≥10 carbons were necessary but not sufficient; they were identified as essential factors by visual comparison of 2-dimensional (2-D) structures in relation to the antiparasite activities of the AQs and were confirmed by computer-based 3-D comparisons and differential contour plots of activity against P. falciparum. The advantage of the method reported here (refinement of quantitative structure-activity relationship [QSAR] descriptors by random assignment of compounds to multiple training and test sets) is that it retains QSAR descriptors according to their abilities to predict the activities of unknown test compounds rather than according to how well they fit the activities of the compounds in the training sets. PMID:21383099

Structure-activity relationships of rosiglitazone for peroxisome proliferator-activated receptor gamma transrepression.

PubMed

Toyota, Yosuke; Nomura, Sayaka; Makishima, Makoto; Hashimoto, Yuichi; Ishikawa, Minoru

2017-06-15

Anti-inflammatory effects of peroxisome proliferator-activated receptor gamma (PPRAγ) ligands are thought to be largely due to PPARγ-mediated transrepression. Thus, transrepression-selective PPARγ ligands without agonistic activity or with only partial agonistic activity should exhibit anti-inflammatory properties with reduced side effects. Here, we investigated the structure-activity relationships (SARs) of PPARγ agonist rosiglitazone, focusing on transrepression activity. Alkenic analogs showed slightly more potent transrepression with reduced efficacy of transactivating agonistic activity. Removal of the alkyl group on the nitrogen atom improved selectivity for transrepression over transactivation. Among the synthesized compounds, 3l exhibited stronger transrepressional activity (IC 50 : 14μM) and weaker agonistic efficacy (11%) than rosiglitazone or pioglitazone. Copyright © 2017 Elsevier Ltd. All rights reserved.

Intrinsic resting-state activity predicts working memory brain activation and behavioral performance.

PubMed

Zou, Qihong; Ross, Thomas J; Gu, Hong; Geng, Xiujuan; Zuo, Xi-Nian; Hong, L Elliot; Gao, Jia-Hong; Stein, Elliot A; Zang, Yu-Feng; Yang, Yihong

2013-12-01

Although resting-state brain activity has been demonstrated to correspond with task-evoked brain activation, the relationship between intrinsic and evoked brain activity has not been fully characterized. For example, it is unclear whether intrinsic activity can also predict task-evoked deactivation and whether the rest-task relationship is dependent on task load. In this study, we addressed these issues on 40 healthy control subjects using resting-state and task-driven [N-back working memory (WM) task] functional magnetic resonance imaging data collected in the same session. Using amplitude of low-frequency fluctuation (ALFF) as an index of intrinsic resting-state activity, we found that ALFF in the middle frontal gyrus and inferior/superior parietal lobules was positively correlated with WM task-evoked activation, while ALFF in the medial prefrontal cortex, posterior cingulate cortex, superior frontal gyrus, superior temporal gyrus, and fusiform gyrus was negatively correlated with WM task-evoked deactivation. Further, the relationship between the intrinsic resting-state activity and task-evoked activation in lateral/superior frontal gyri, inferior/superior parietal lobules, superior temporal gyrus, and midline regions was stronger at higher WM task loads. In addition, both resting-state activity and the task-evoked activation in the superior parietal lobule/precuneus were significantly correlated with the WM task behavioral performance, explaining similar portions of intersubject performance variance. Together, these findings suggest that intrinsic resting-state activity facilitates or is permissive of specific brain circuit engagement to perform a cognitive task, and that resting activity can predict subsequent task-evoked brain responses and behavioral performance. Copyright © 2012 Wiley Periodicals, Inc.

Antioxidative Activities and Active Compounds of Extracts from Catalpa Plant Leaves

PubMed Central

Xu, Hongyu; Hu, Gege; Dong, Juane; Wei, Qin; Shao, Hongbo; Lei, Ming

2014-01-01

In order to screen the Catalpa plant with high antioxidant activity and confirm the corresponding active fractions from Catalpa ovata G. Don, C. fargesii Bur., and C. bungei C. A. Mey., total flavonoid contents and antioxidant activities of the extracts/fractions of Catalpa plant leaves were determined. The determined total flavonoid content and antioxidant activity were used as assessment criteria. Those compounds with antioxidant activity were isolated with silica gel column chromatography and ODS column chromatography. Our results showed that the total flavonoid content in C. bungei C. A. Mey. (30.07 mg/g·DW) was the highest, followed by those in C. fargesii Bur. (25.55 mg/g·DW) and C. ovata G. Don (24.96 mg/g·DW). According to the determination results of total flavonoid content and antioxidant activity in 3 clones of leaves of C. bungei C. A. Mey., the total flavonoid content and antioxidant activity in crude extracts from C. bungei C. A. Mey. 6 (CA6) leaves were the highest. Moreover, the results showed that the total flavonoid content and antioxidant activities of ethyl acetate (EA) fraction in ethanol crude extracts in CA6 leaves were the highest, followed by n-butanol, petroleum ether (PE), and water fractions. Two flavonoid compounds with antioxidant activity were firstly isolated based on EA fraction. The two compounds were luteolin (1) and apigenin (2), respectively. PMID:25431795

Impact of an active video game on healthy children's physical activity.

PubMed

Baranowski, Tom; Abdelsamad, Dina; Baranowski, Janice; O'Connor, Teresia Margareta; Thompson, Debbe; Barnett, Anthony; Cerin, Ester; Chen, Tzu-An

2012-03-01

This naturalistic study tests whether children receiving a new (to them) active video game spontaneously engage in more physical activity than those receiving an inactive video game, and whether the effect would be greater among children in unsafe neighborhoods, who might not be allowed to play outside. Participants were children 9 to 12 years of age, with a BMI >50th percentile, but <99th percentile; none of these children a medical condition that would preclude physical activity or playing video games. A randomized clinical trial assigned children to receiving 2 active or 2 inactive video games, the peripherals necessary to run the games, and a Wii console. Physical activity was monitored by using accelerometers for 5 weeks over the course of a 13-week experiment. Neighborhood safety was assessed with a 12 item validated questionnaire. There was no evidence that children receiving the active video games were more active in general, or at anytime, than children receiving the inactive video games. The outcomes were not moderated by parent perceived neighborhood safety, child BMI z score, or other demographic characteristics. These results provide no reason to believe that simply acquiring an active video game under naturalistic circumstances provides a public health benefit to children.

Evaluation of a novel canine activity monitor for at-home physical activity analysis.

PubMed

Yashari, Jonathan M; Duncan, Colleen G; Duerr, Felix M

2015-07-04

Accelerometers are motion-sensing devices that have been used to assess physical activity in dogs. However, the lack of a user-friendly, inexpensive accelerometer has hindered the widespread use of this objective outcome measure in veterinary research. Recently, a smartphone-based, affordable activity monitor (Whistle) has become available for measurement of at-home physical activity in dogs. The aim of this research was to evaluate this novel accelerometer. Eleven large breed, privately owned dogs wore a collar fitted with both the Whistle device and a previously validated accelerometer-based activity monitor (Actical) for a 24-h time period. Owners were asked to have their dogs resume normal daily activities. Total activity time obtained from the Whistle device in minutes was compared to the total activity count from the Actical device. Activity intensity from the Whistle device was calculated manually from screenshots of the activity bars displayed in the smartphone-application and compared to the activity count recorded by the Actical in the same 3-min time period. A total of 3740 time points were compared. There was a strong correlation between activity intensity of both devices for individual time points (Pearson's correlation coefficient 0.81, p < 0.0001). An even stronger correlation was observed between the total activity data between the two devices (Pearson's correlation coefficient 0.925, p < 0.0001). Activity data provided by the Whistle activity monitor may be used as an objective outcome measurement in dogs. The total activity time provided by the Whistle application offers an inexpensive method for obtaining at-home, canine, real-time physical activity data. Limitations of the Whistle device include the limited battery life, the need for manual derivation of activity intensity data and data transfer, and the requirement of Wi-Fi and Bluetooth availability for data transmission.

Serotonin Activates Overall Feeding by Activating Two Separate Neural Pathways in Caenorhabditis elegans

PubMed Central

Song, Bo-mi; Avery, Leon

2012-01-01

Food intake in the nematode Caenorhabditis elegans requires two distinct feeding motions, pharyngeal pumping and isthmus peristalsis. Bacteria, the natural food of C. elegans, activate both feeding motions (Croll, 1978; Horvitz et al., 1982; Chiang et al., 2006). The mechanisms by which bacteria activate the feeding motions are largely unknown. To understand the process, we studied how serotonin, an endogenous pharyngeal pumping activator whose action is triggered by bacteria, activates feeding motions. Here, we show that serotonin, like bacteria, activates overall feeding by activating isthmus peristalsis as well as pharyngeal pumping. During active feeding, the frequencies and the timing of onset of the two motions were distinct, but each isthmus peristalsis was coupled to the preceding pump. We found that serotonin activates the two feeding motions mainly by activating two separate neural pathways in response to bacteria. For activating pumping, the SER-7 serotonin receptor in the MC motor neurons in the feeding organ activated cholinergic transmission from MC to the pharyngeal muscles by activating the Gsα signaling pathway. For activating isthmus peristalsis, SER-7 in the M4 (and possibly M2) motor neuron in the feeding organ activated the G12α signaling pathway in a cell-autonomous manner, which presumably activates neurotransmission from M4 to the pharyngeal muscles. Based on our results and previous calcium imaging of pharyngeal muscles (Shimozono et al., 2004), we propose a model that explains how the two feeding motions are separately regulated yet coupled. The feeding organ may have evolved this way to support efficient feeding. PMID:22323705

Activation of neurotensin receptor type 1 attenuates locomotor activity.

PubMed

Vadnie, Chelsea A; Hinton, David J; Choi, Sun; Choi, YuBin; Ruby, Christina L; Oliveros, Alfredo; Prieto, Miguel L; Park, Jun Hyun; Choi, Doo-Sup

2014-10-01

Intracerebroventricular administration of neurotensin (NT) suppresses locomotor activity. However, the brain regions that mediate the locomotor depressant effect of NT and receptor subtype-specific mechanisms involved are unclear. Using a brain-penetrating, selective NT receptor type 1 (NTS1) agonist PD149163, we investigated the effect of systemic and brain region-specific NTS1 activation on locomotor activity. Systemic administration of PD149163 attenuated the locomotor activity of C57BL/6J mice both in a novel environment and in their homecage. However, mice developed tolerance to the hypolocomotor effect of PD149163 (0.1 mg/kg, i.p.). Since NTS1 is known to modulate dopaminergic signaling, we examined whether PD149163 blocks dopamine receptor-mediated hyperactivity. Pretreatment with PD149163 (0.1 or 0.05 mg/kg, i.p.) inhibited D2R agonist bromocriptine (8 mg/kg, i.p.)-mediated hyperactivity. D1R agonist SKF-81297 (8 mg/kg, i.p.)-induced hyperlocomotion was only inhibited by 0.1 mg/kg of PD149163. Since the nucleus accumbens (NAc) and medial prefrontal cortex (mPFC) have been implicated in the behavioral effects of NT, we examined whether microinjection of PD149163 into these regions reduces locomotion. Microinjection of PD149163 (2 pmol) into the NAc, but not the mPFC suppressed locomotor activity. In summary, our results indicate that systemic and intra-NAc activation of NTS1 is sufficient to reduce locomotion and NTS1 activation inhibits D2R-mediated hyperactivity. Our study will be helpful to identify pharmacological factors and a possible therapeutic window for NTS1-targeted therapies for movement disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

Vision Drives Correlated Activity without Patterned Spontaneous Activity in Developing Xenopus Retina

PubMed Central

Demas, James A.; Payne, Hannah; Cline, Hollis T.

2011-01-01

Developing amphibians need vision to avoid predators and locate food before visual system circuits fully mature. Xenopus tadpoles can respond to visual stimuli as soon as retinal ganglion cells (RGCs) innervate the brain, however, in mammals, chicks and turtles, RGCs reach their central targets many days, or even weeks, before their retinas are capable of vision. In the absence of vision, activity-dependent refinement in these amniote species is mediated by waves of spontaneous activity that periodically spread across the retina, correlating the firing of action potentials in neighboring RGCs. Theory suggests that retinorecipient neurons in the brain use patterned RGC activity to sharpen the retinotopy first established by genetic cues. We find that in both wild type and albino Xenopus tadpoles, RGCs are spontaneously active at all stages of tadpole development studied, but their population activity never coalesces into waves. Even at the earliest stages recorded, visual stimulation dominates over spontaneous activity and can generate patterns of RGC activity similar to the locally correlated spontaneous activity observed in amniotes. In addition, we show that blocking AMPA and NMDA type glutamate receptors significantly decreases spontaneous activity in young Xenopus retina, but that blocking GABAA receptor blockers does not. Our findings indicate that vision drives correlated activity required for topographic map formation. They further suggest that developing retinal circuits in the two major subdivisions of tetrapods, amphibians and amniotes, evolved different strategies to supply appropriately patterned RGC activity to drive visual circuit refinement. PMID:21312343

Active, capable, and potentially active faults - a paleoseismic perspective

USGS Publications Warehouse

Machette, M.N.

2000-01-01

Maps of faults (geologically defined source zones) may portray seismic hazards in a wide range of completeness depending on which types of faults are shown. Three fault terms - active, capable, and potential - are used in a variety of ways for different reasons or applications. Nevertheless, to be useful for seismic-hazards analysis, fault maps should encompass a time interval that includes several earthquake cycles. For example, if the common recurrence in an area is 20,000-50,000 years, then maps should include faults that are 50,000-100,000 years old (two to five typical earthquake cycles), thus allowing for temporal variability in slip rate and recurrence intervals. Conversely, in more active areas such as plate boundaries, maps showing faults that are <10,000 years old should include those with at least 2 to as many as 20 paleoearthquakes. For the International Lithosphere Programs' Task Group II-2 Project on Major Active Faults of the World our maps and database will show five age categories and four slip rate categories that allow one to select differing time spans and activity rates for seismic-hazard analysis depending on tectonic regime. The maps are accompanied by a database that describes evidence for Quaternary faulting, geomorphic expression, and paleoseismic parameters (slip rate, recurrence interval and time of most recent surface faulting). These maps and databases provide an inventory of faults that would be defined as active, capable, and potentially active for seismic-hazard assessments.

Light and dark-activated biocidal activity of conjugated polyelectrolytes.

PubMed

Ji, Eunkyung; Corbitt, Thomas S; Parthasarathy, Anand; Schanze, Kirk S; Whitten, David G

2011-08-01

This Spotlight on Applications provides an overview of a research program that has focused on the development and mechanistic study of cationic conjugated polyelectrolytes (CPEs) that function as light- and dark-active biocidal agents. Investigation has centered on poly-(phenylene ethynylene) (PPE) type conjugated polymers that are functionalized with cationic quaternary ammonium solubilizing groups. These polymers are found to interact strongly with Gram-positive and Gram-negative bacteria, and upon illumination with near-UV and visible light act to rapidly kill the bacteria. Mechanistic studies suggest that the cationic PPE-type polymers efficiently sensitize singlet oxygen ((1)O(2)), and this cytotoxic agent is responsible for initiating the sequence of events that lead to light-activated bacterial killing. Specific CPEs also exhibit dark-active antimicrobial activity, and this is believed to arise due to interactions between the cationic/lipophilic polymers and the negatively charged outer membrane characteristic of Gram-negative bacteria. Specific results are shown where a cationic CPE with a degree of polymerization of 49 exhibits pronounced light-activated killing of E. coli when present in the cell suspension at a concentration of 1 μg mL(-1).

Forecasting Occurrences of Activities.

PubMed

Minor, Bryan; Cook, Diane J

2017-07-01

While activity recognition has been shown to be valuable for pervasive computing applications, less work has focused on techniques for forecasting the future occurrence of activities. We present an activity forecasting method to predict the time that will elapse until a target activity occurs. This method generates an activity forecast using a regression tree classifier and offers an advantage over sequence prediction methods in that it can predict expected time until an activity occurs. We evaluate this algorithm on real-world smart home datasets and provide evidence that our proposed approach is most effective at predicting activity timings.

Theory-based physical activity beliefs by race and activity levels among older adults.

PubMed

Kosma, Maria; Cardinal, Bradley J

2016-01-01

Given the benefits of physical activity and the high proportion of inactivity among older adults, the purpose was to elicit theory-based behavioral, normative, and control physical activity beliefs among 140 educationally and economically diverse older adults and compare their beliefs by race (Blacks vs. Whites) and physical activity levels (inactive/underactive vs. highly active individuals). This was an elicitation study that took place in eight, mostly rural community settings in a Southeastern US state, such as Council of Aging Offices, retirement centers, and churches. Participants' behavioral, normative, and control beliefs were elicited via in person interviews. A valid and reliable questionnaire was also used to assess their physical activity levels. According to the content analysis, inactive/underactive participants reported fewer physical activity advantages than highly active participants. Common physical activity advantages between the two groups were overall health, emotional functioning, and physical functioning. Similar physical activity advantages were reported among Blacks and Whites with overall health being the most important advantage. The most common physical activity disadvantages and barriers for all four groups were falls, injuries, pain, and health issues. Inactive/underactive individuals and Blacks tended to report more disadvantages and barriers than their peers. Common physical activity supporters were family members, friends and peers, and health-care professionals. In their physical activity motivational programs, health promoters should reinforce physical activity benefits, social support, access to activity programs, and safety when intervening among older adults.

College Student Environmental Activism: How Experiences and Identities Influence Environmental Activism Approaches

ERIC Educational Resources Information Center

King, Laura A. H.

2016-01-01

College student environmental activism is one way students civically engage in addressing social issues. This study explores the environmental activism of twelve college students and how their experiences outside of college and in college influenced their activism. In addition, how students' identities influenced their approach to activism was…

The Role of Physical Activity Assessments for School-Based Physical Activity Promotion

ERIC Educational Resources Information Center

Welk, Gregory J.

2008-01-01

The emphasis in public health on lifestyle physical activity in recent years has focused attention on the promotion of lifetime physical activity as the primary objective of physical education. If used properly, physical activity and physical fitness assessments can enhance individual promotion of physical activity and also provide valuable…

Ladders to Literacy: A Preschool Activity Book [and] A Kindergarten Activity Book.

ERIC Educational Resources Information Center

Notari-Syverson, Angela; O'Connor, Rollanda E.; Vadasy, Patricia F.

This preschool activity book and kindergarten activity book set provide a curriculum of 114 activities to develop emergent literacy skills in preschool and kindergarten children. The curriculum is based on research findings and is intended to be ecologically valid, embedding activities into developmentally appropriate, daily classroom routines and…

Active Cytokinins

PubMed Central

Mornet, René; Theiler, Jane B.; Leonard, Nelson J.; Schmitz, Ruth Y.; Moore, F. Hardy; Skoog, Folke

1979-01-01

Four series of azidopurines have been synthesized and tested for cytokinin activity in the tobacco callus bioassay: 2- and 8-azido-N6-benzyladenines, -N6-(Δ2-isopentenyl)adenines, and -zeatins, and N6-(2- and 4-azidobenzyl)adenines. The compounds having 2-azido substitution on the adenine ring are as active as the corresponding parent compounds, while those with 8-azido substitution are about 10 or more times as active. The 8-azidozeatin, which is the most active cytokinin observed, exhibited higher than minimal detectable activity at 1.2 × 10−5 micromolar, the lowest concentration tested. The shape of the growth curve indicates that even a concentration as low as 5 × 10−6 micromolar would probably be effective. By comparison, the lowest active concentration ever reported for zeatin has been 5 × 10−5 micromolar, representing a sensitivity rarely attained. All of the azido compounds have been submitted to photolysis in aqueous ethanol, and the photoproducts have been detected and identified by low and high resolution mass spectrometry. They are rationalized as products of abstraction and insertion reactions of the intermediate nitrenes. The potential of the major released products as cytokinins was also assessed by bioassay. 2-Azido-N6-(Δ2-isopentenyl)adenine competed with [14C]kinetin for the cytokinin-binding protein isolated from wheat germ. When the azido compound was photolysed in the presence of this protein, its attachment effectively blocked the binding of [14C]kinetin. PMID:16661017

Computer-aided drug design for AMP-activated protein kinase activators.

PubMed

Wang, Zhanli; Huo, Jianxin; Sun, Lidan; Wang, Yongfu; Jin, Hongwei; Yu, Hui; Zhang, Liangren; Zhou, Lishe

2011-09-01

AMP-activated protein kinase (AMPK) is an important therapeutic target for the potential treatment of metabolic disorders, cardiovascular disease and cancer. Recently, various classes of compounds that activate AMPK by direct or indirect interactions have been reported. The importance of computer-aided drug design approaches in the search for potent activators of AMPK is now established, including structure-based design, ligand-based design, fragment-based design, as well as structural analysis. This review article highlights the computer-aided drug design approaches utilized to discover of activators targeting AMPK. The principles, advantages or limitation of the different methods are also being discussed together with examples of applications taken from the literatures.

Inferring deep-brain activity from cortical activity using functional near-infrared spectroscopy

PubMed Central

Liu, Ning; Cui, Xu; Bryant, Daniel M.; Glover, Gary H.; Reiss, Allan L.

2015-01-01

Functional near-infrared spectroscopy (fNIRS) is an increasingly popular technology for studying brain function because it is non-invasive, non-irradiating and relatively inexpensive. Further, fNIRS potentially allows measurement of hemodynamic activity with high temporal resolution (milliseconds) and in naturalistic settings. However, in comparison with other imaging modalities, namely fMRI, fNIRS has a significant drawback: limited sensitivity to hemodynamic changes in deep-brain regions. To overcome this limitation, we developed a computational method to infer deep-brain activity using fNIRS measurements of cortical activity. Using simultaneous fNIRS and fMRI, we measured brain activity in 17 participants as they completed three cognitive tasks. A support vector regression (SVR) learning algorithm was used to predict activity in twelve deep-brain regions using information from surface fNIRS measurements. We compared these predictions against actual fMRI-measured activity using Pearson’s correlation to quantify prediction performance. To provide a benchmark for comparison, we also used fMRI measurements of cortical activity to infer deep-brain activity. When using fMRI-measured activity from the entire cortex, we were able to predict deep-brain activity in the fusiform cortex with an average correlation coefficient of 0.80 and in all deep-brain regions with an average correlation coefficient of 0.67. The top 15% of predictions using fNIRS signal achieved an accuracy of 0.7. To our knowledge, this study is the first to investigate the feasibility of using cortical activity to infer deep-brain activity. This new method has the potential to extend fNIRS applications in cognitive and clinical neuroscience research. PMID:25798327

Tea enhances insulin activity.

PubMed

Anderson, Richard A; Polansky, Marilyn M

2002-11-20

The most widely known health benefits of tea relate to the polyphenols as the principal active ingredients in protection against oxidative damage and in antibacterial, antiviral, anticarcinogenic, and antimutagenic activities, but polyphenols in tea may also increase insulin activity. The objective of this study was to determine the insulin-enhancing properties of tea and its components. Tea, as normally consumed, was shown to increase insulin activity >15-fold in vitro in an epididymal fat cell assay. Black, green, and oolong teas but not herbal teas, which are not teas in the traditional sense because they do not contain leaves of Camellia senensis, were all shown to increase insulin activity. High-performance liquid chromatography fractionation of tea extracts utilizing a Waters SymmetryPrep C18 column showed that the majority of the insulin-potentiating activity for green and oolong teas was due to epigallocatechin gallate. For black tea, the activity was present in several regions of the chromatogram corresponding to, in addition to epigallocatechin gallate, tannins, theaflavins, and other undefined compounds. Several known compounds found in tea were shown to enhance insulin with the greatest activity due to epigallocatechin gallate followed by epicatechin gallate, tannins, and theaflavins. Caffeine, catechin, and epicatechin displayed insignificant insulin-enhancing activities. Addition of lemon to the tea did not affect the insulin-potentiating activity. Addition of 5 g of 2% milk per cup decreased the insulin-potentiating activity one-third, and addition of 50 g of milk per cup decreased the insulin-potentiating activity approximately 90%. Nondairy creamers and soy milk also decreased the insulin-enhancing activity. These data demonstrate that tea contains in vitro insulin-enhancing activity and the predominant active ingredient is epigallocatechin gallate.

Bonus Activity Book.

ERIC Educational Resources Information Center

Learning, 1992

1992-01-01

Provides on-task activities to fill in unexpected extra moments in elementary classes. The activities require little preparation and take 5-15 minutes to complete. There are activities for math, language arts, social science, science, critical thinking, and computer. An outer space board game is also included. (SM)

Active chiral fluids.

PubMed

Fürthauer, S; Strempel, M; Grill, S W; Jülicher, F

2012-09-01

Active processes in biological systems often exhibit chiral asymmetries. Examples are the chirality of cytoskeletal filaments which interact with motor proteins, the chirality of the beat of cilia and flagella as well as the helical trajectories of many biological microswimmers. Here, we derive constitutive material equations for active fluids which account for the effects of active chiral processes. We identify active contributions to the antisymmetric part of the stress as well as active angular momentum fluxes. We discuss four types of elementary chiral motors and their effects on a surrounding fluid. We show that large-scale chiral flows can result from the collective behavior of such motors even in cases where isolated motors do not create a hydrodynamic far field.

Porous properties of activated carbons from waste newspaper prepared by chemical and physical activation.

PubMed

Okada, Kiyoshi; Yamamoto, Nobuo; Kameshima, Yoshikazu; Yasumori, Atsuo

2003-06-01

Activated carbons were prepared from old newspaper and paper prepared from simulated paper sludge by chemical activation using various alkali carbonates and hydroxides as activating reagents and also by physical activation using steam. In the chemical activation, the influence of oxidation, carbonization, and activation on the porous properties of the resulting activated carbons was investigated. The specific surface areas (S(BET)) of the activated carbons prepared by single-step activation (direct activation without oxidation and carbonization) were higher than those resulting from two-step activation (oxidation-activation and carbonization-activation) and three-step activation (oxidation-carbonization-activation) methods. The S(BET) values were strongly dependent on the activating reagents and the activating conditions, being >1000 m(2)/g using K(2)CO(3), Rb(2)CO(3), Cs(2)CO(3), and KOH as activating reagents but <1000 m(2)/g using Li(2)CO(3), Na(2)CO(3), and NaOH. These differences in S(BET) values are suggested to be related to the ionic radii of the alkalis used as activating reagents. The microstructures of the higher S(BET) samples show a complete loss of fiber shape but those of the lower S(BET) samples maintain the shape. In the physical activation, the porous properties of the activated carbons prepared by the single-step method were examined as a function of the production conditions such as activation temperature, activation time, steam concentration, and flow rate of the carrier gas. The maximum S(BET) and total pore volume (V(P)) were 1086 m(2)/g and 1.01 ml/g, obtained by activation at 850 degrees C for 2 h, flowing 20 mol% of steam in nitrogen gas at 0.5 l/min. A correlation was found between S(BET) and the yield of the product, the maximum S(BET) value corresponding to a product yield of about 10%. This result is suggested to result from competition between pore formation and surface erosion. Compared with chemically activated carbons using K(2)CO

Trunk muscle activation during dynamic weight-training exercises and isometric instability activities.

PubMed

Hamlyn, Nicolle; Behm, David G; Young, Warren B

2007-11-01

The purpose of this study was to examine the extent of activation in various trunk muscles during dynamic weight-training and isometric instability exercises. Sixteen subjects performed squats and deadlifts with 80% 1 repetition maximum (1RM), as well as with body weight as resistance and 2 unstable calisthenic-type exercises (superman and sidebridge). Electromyographic (EMG) activity was measured from the lower abdominals (LA), external obliques (EO), upper lumbar erector spinae (ULES), and lumbar-sacral erector spinae (LSES) muscle groups. Results indicated that the LSES EMG activity during the 80% 1RM squat significantly exceeded 80% 1RM deadlift LSES EMG activity by 34.5%. The LSES EMG activity of the 80% 1RM squat also exceeded the body weight squat, deadlift, superman, and sidebridge by 56, 56.6, 65.5, and 53.1%, respectively. The 80% 1RM deadlift ULES EMG activity significantly exceeded the 80% 1RM squat exercise by 12.9%. In addition, the 80% 1RM deadlift ULES EMG activity also exceeded the body weight squat, deadlift, superman, and sidebridge exercises by 66.7, 65.5, 69.3, and 68.6%, respectively. There were no significant changes in EO or LA activity. Therefore, the augmented activity of the LSES and ULES during 80% 1RM squat and deadlift resistance exercises exceeded the activation levels achieved with the same exercises performed with body weight and selected instability exercises. Individuals performing upright, resisted, dynamic exercises can achieve high trunk muscle activation and thus may not need to add instability device exercises to augment core stability training.

Physical activity during hospitalization: Activities and preferences of adults versus older adults.

PubMed

Meesters, Jorit; Conijn, D; Vermeulen, H M; Vliet Vlieland, Tpm

2018-04-16

Inactivity during hospitalization leads to a functional decline and an increased risk of complications. To date, studies focused on older adults. This study aims to compare the physical activities performed by older adult and adult hospitalized patients. Patients hospitalized for >3 days at a university hospital completed a questionnaire regarding their physical activities (% of days on which an activity was performed divided by the length of stay) and physical activity needs during hospitalization. Crude and adjusted comparisons of older adult (>60 years) and adult (≤60 years) patients were performed using parametric testing and regression analyses. Of 524 patients, 336 (64%) completed the questionnaire, including 166 (49%) older adult patients. On average, the patients were physically active on 35% or less of the days during their hospitalization. Linear regression analysis showed no significant associations between being an older adult and performing physical activities after adjusting for gender, length of stay, surgical intervention, and meeting physical activity recommendations prior to hospitalization. Most patients were well informed regarding physical activity during hospitalization; however, the older adult patients reported a need for information regarding physical activities after hospitalization more frequently (odds ratios, 2.47) after adjusting for educational level, gender, and physical therapy during hospitalization. Both older adult and adult patients are physically inactive during hospitalization, and older adult patients express a greater need for additional information regarding physical activity after hospitalization than adult patients. Therefore, personalized strategies that inform and motivate patients to resume physical activities during hospitalization are needed regardless of age.

Association between recent sports activity, sports activity in young adulthood, and stroke.

PubMed

Grau, Armin J; Barth, Cordula; Geletneky, Beate; Ling, Paul; Palm, Frederik; Lichy, Christoph; Becher, Heiko; Buggle, Florian

2009-02-01

Leisure-time physical activity protects from stroke. It is insufficiently established whether early lifetime physical activity is independently protective and whether some etiologic stroke subgroups particularly benefit from physical activity. We tested the hypothesis that both recent and early-adulthood sports activities are associated with reduced odds of stroke and analyzed their effects in stroke subtypes. We performed a case-control study of 370 patients with acute stroke or transient ischemic attack (TIA) and 370 age- and sex-matched control subjects randomly selected from the population and assessed recent and young adulthood sports activities and their weekly duration in standardized interviews. Recent regular sports activities were less often reported by patients (94/370, 25.4%) than by control subjects (162/370, 43.8%; P<0.0001). After adjustment for vascular risk factors, education, and other factors, recent participation in sports was significantly associated with reduced odds of stroke/TIA (odds ratio=0.64; 95% CI, 0.43 to 0.96). Both groups did not differ with regard to sports activities in young adulthood. More control subjects (69/365, 18.9%) than patients (25/361, 6.9%) participated in sports recently after not having been active in young adulthood, and such a pattern was associated with reduced odds of stroke/TIA in multivariable analysis (odds ratio=0.37; 95% CI, 0.21 to 0.85). Our study supports previous results that have shown stroke protection by physical activity. Results suggest that continuous lifetime activity or starting activities during later adulthood is required to reduce stroke risk.

Control of Promatrilysin (MMP7) Activation and Substrate-specific Activity by Sulfated Glycosaminoglycans*

PubMed Central

Ra, Hyun-Jeong; Harju-Baker, Susanna; Zhang, Fuming; Linhardt, Robert J.; Wilson, Carole L.; Parks, William C.

2009-01-01

Matrix metalloproteinases are maintained in an inactive state by a bond between the thiol of a conserved cysteine in the prodomain and a zinc atom in the catalytic domain. Once this bond is disrupted, MMPs become active proteinases and can act on a variety of extracellular protein substrates. In vivo, matrilysin (MMP7) activates pro-α-defensins (procryptdins), but in vitro, processing of these peptides is slow, with about 50% conversion in 8–12 h. Similarly, autolytic activation of promatrilysin in vitro can take up to 12–24 h for 50% conversion. These inefficient reactions suggest that natural cofactors enhance the activation and activity of matrilysin. We determined that highly sulfated glycosaminoglycans (GAG), such as heparin, chondroitin-4,6-sulfate (CS-E), and dermatan sulfate, markedly enhanced (>50-fold) the intermolecular autolytic activation of promatrilysin and the activity of fully active matrilysin to cleave specific physiologic substrates. In contrast, heparan sulfate and less sulfated forms of chondroitin sulfate did not augment matrilysin activation or activity. Chondroitin-2,6-sulfate (CS-D) also did not enhance matrilysin activity, suggesting that the presentation of sulfates is more important than the overall degree of sulfation. Surface plasmon resonance demonstrated that promatrilysin bound heparin (KD, 400 nm) and CS-E (KD, 630 nm). Active matrilysin bound heparin (KD, 150 nm) but less so to CS-E (KD, 60 μm). Neither form bound heparan sulfate. These observations demonstrate that sulfated GAGs regulate matrilysin activation and its activity against specific substrates. PMID:19654318

Strand displacement activated peroxidase activity of hemin for fluorescent DNA sensing.

PubMed

Wang, Quanbo; Xu, Nan; Gui, Zhen; Lei, Jianping; Ju, Huangxian; Yan, Feng

2015-10-07

To efficiently regulate the catalytic activity of the peroxidase mimic hemin, this work designs a double-stranded DNA probe containing an intermolecular dimer of hemin, whose peroxidase activity can be activated by a DNA strand displacement reaction. The double-stranded probe is prepared by annealing two strands of hemin labelled DNA oligonucleotides. Using the fluorescent oxidation product of tyramine by H2O2 as a tracing molecule, the low peroxidase activity of the hemin dimer ensures a low fluorescence background. The strand displacement reaction of the target DNA dissociates the hemin dimer and thus significantly increases the catalytic activity of hemin to produce a large amount of dityramine for fluorescence signal readout. Based on the strand displacement regulated peroxidase activity, a simple and sensitive homogeneous fluorescent DNA sensing method is proposed. The detection can conveniently be carried out in a 96-well plate within 20 min with a detection limit of 0.18 nM. This method shows high specificity, which can effectively distinguish single-base mismatched DNA from perfectly matched target DNA. The DNA strand displacement regulated catalytic activity of hemin has promising application in the determination of various DNA analytes.

Influence of plasma-activated compounds on melanogenesis and tyrosinase activity

PubMed Central

Ali, Anser; Ashraf, Zaman; Kumar, Naresh; Rafiq, Muhammad; Jabeen, Farukh; Park, Ji Hoon; Choi, Ki Hong; Lee, SeungHyun; Seo, Sung-Yum; Choi, Eun Ha; Attri, Pankaj

2016-01-01

Many organic chemists around the world synthesize medicinal compounds or extract multiple compounds from plants in order to increase the activity and quality of medicines. In this work, we synthesized new eugenol derivatives (ED) and then treated them with an N2 feeding gas atmospheric pressure plasma jet (APPJ) to increase their utility. We studied the tyrosinase-inhibition activity (activity test) and structural changes (circular dichroism) of tyrosinase with ED and plasma activated eugenol derivatives (PAED) in a cell-free environment. Later, we used docking studies to determine the possible interaction sites of ED and PAED compounds with tyrosinase enzyme. Moreover, we studied the possible effect of ED and PAED on melanin synthesis and its mechanism in melanoma (B16F10) cells. Additionally, we investigated the structural changes that occurred in activated ED after plasma treatment using nuclear magnetic resonance (NMR). Hence, this study provides a new perspective on PAED for the field of plasma medicine. PMID:26931617

Antioxidant activity and antibacterial activity of peach gum derived oligosaccharides.

PubMed

Yao, Xing-Cun; Cao, Yan; Wu, Sheng-Jun

2013-11-01

In this study, peach gum derived oligosaccharides (PGDO) were prepared from peach gum polysaccharides by hydrolysis using hydrogen peroxide (H2O2) under following conditions: time, 8h; temperature, 55 °C; H2O2 concentration, 4% (v/v); and NaOH concentration, 2.0 M. The antioxidant activity and antibacterial activity of PGDO were estimated. There were no significant chemical changes in the backbones of the peach gum polysaccharides treated with H2O2. The PGDO showed high hydroxyl radical scavenging activity (86.12%) and 2, 2-diphenyl-β-picrylhydrazyl radical scavenging activity (91.70%) at the concentration of 100 μg/mL as well as high reducing capacity at the concentration of 50 μg/mL. In addition the PGDO had high antibacterial activity against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli at the concentration of 100 μg/mL. Copyright © 2013 Elsevier B.V. All rights reserved.

Active Flow Control Activities at NASA Langley

NASA Technical Reports Server (NTRS)

Anders, Scott G.; Sellers, William L., III; Washburn, Anthony E.

2004-01-01

NASA Langley continues to aggressively investigate the potential advantages of active flow control over more traditional aerodynamic techniques. This paper provides an update to a previous paper and describes both the progress in the various research areas and the significant changes in the NASA research programs. The goals of the topics presented are focused on advancing the state of knowledge and understanding of controllable fundamental mechanisms in fluids as well as to address engineering challenges. An organizational view of current research activities at NASA Langley in active flow control as supported by several projects is presented. On-center research as well as NASA Langley funded contracts and grants are discussed at a relatively high level. The products of this research are to be demonstrated either in bench-top experiments, wind-tunnel investigations, or in flight as part of the fundamental NASA R&D program and then transferred to more applied research programs within NASA, DOD, and U.S. industry.

Optimizing post activation potentiation for explosive activities in competitive sports

PubMed Central

Gołaś, Artur; Maszczyk, Adam; Mikołajec, Kazimierz; Stastny, Petr

2016-01-01

Abstract Post activation potentiation (PAP) has shown improved performance during movements requiring large muscular power output following contractions under near maximal load conditions. PAP can be described as an acute enhancement of performance or an enhancement of factors determining an explosive sports activity following a preload stimulus. In practice, PAP has been achieved by complex training, which involves a combination of a heavy loaded exercise followed by a biomechanically similar explosive activity, best if specific for a particular sport discipline. The main objective of this study was to investigate the effects of PAP on performance in explosive motor activities specific for basketball, luge and athletics throws. The novel approach to the experiments included individualized recovery time (IRT) between the conditioning exercise and the explosive activity. Additionally, the research groups were homogenous and included only competitive athletes of similar age and training experience. Thirty one well trained athletes from 3 different sport disciplines participated in the study. All athletes performed a heavy loaded conditioning activity (80-130%1RM) followed by a biomechanically similar explosive exercise, during which power (W) or the rate of power development (W/s/kg) was evaluated. The results of our experiment confirmed the effectiveness of PAP with well-trained athlets during explosive motor activities such as jumping, throwing and pushing. Additionally, our research showed that eccentric supramaximal intensities (130% 1RM) can be effective in eliciting PAP in strength trained athletes. Our experiments also showed that the IRT should be individualized because athletes differ in the strength level, training experience and muscle fiber structure. In the three experiments conducted with basketball players, track and field athletes and luge athletes, the optimal IRT equaled 6 min. This justifies the need to individualize the volume and intensity of the

The Use of Multiple Slate Devices to Support Active Reading Activities

ERIC Educational Resources Information Center

Chen, Nicholas Yen-Cherng

2012-01-01

Reading activities in the classroom and workplace occur predominantly on paper. Since existing electronic devices do not support these reading activities as well as paper, users have difficulty taking full advantage of the affordances of electronic documents. This dissertation makes three main contributions toward supporting active reading…

An Active Learning Activity to Reinforce the Design Components of the Corticosteroids

PubMed Central

Mandela, Prashant

2018-01-01

Despite the popularity of active learning applications over the past few decades, few activities have been reported for the field of medicinal chemistry. The purpose of this study is to report a new active learning activity, describe participant contributions, and examine participant performance on the assessment questions mapped to the objective covered by the activity. In this particular activity, students are asked to design two novel corticosteroids as a group (6–8 students per group) based on the design characteristics of marketed corticosteroids covered in lecture coupled with their pharmaceutics knowledge from the previous semester and then defend their design to the class through an interactive presentation model. Although class performance on the objective mapped to this material on the assessment did not reach statistical significance, use of this activity has allowed fruitful discussion of misunderstood concepts and facilitated multiple changes to the lecture presentation. As pharmacy schools continue to emphasize alternative learning pedagogies, publication of previously implemented activities demonstrating their use will help others apply similar methodologies. PMID:29401733

An Active Learning Activity to Reinforce the Design Components of the Corticosteroids.

PubMed

Slauson, Stephen R; Mandela, Prashant

2018-02-05

Despite the popularity of active learning applications over the past few decades, few activities have been reported for the field of medicinal chemistry. The purpose of this study is to report a new active learning activity, describe participant contributions, and examine participant performance on the assessment questions mapped to the objective covered by the activity. In this particular activity, students are asked to design two novel corticosteroids as a group (6-8 students per group) based on the design characteristics of marketed corticosteroids covered in lecture coupled with their pharmaceutics knowledge from the previous semester and then defend their design to the class through an interactive presentation model. Although class performance on the objective mapped to this material on the assessment did not reach statistical significance, use of this activity has allowed fruitful discussion of misunderstood concepts and facilitated multiple changes to the lecture presentation. As pharmacy schools continue to emphasize alternative learning pedagogies, publication of previously implemented activities demonstrating their use will help others apply similar methodologies.

Active touch sensing

PubMed Central

Prescott, Tony J.; Diamond, Mathew E.; Wing, Alan M.

2011-01-01

Active sensing systems are purposive and information-seeking sensory systems. Active sensing usually entails sensor movement, but more fundamentally, it involves control of the sensor apparatus, in whatever manner best suits the task, so as to maximize information gain. In animals, active sensing is perhaps most evident in the modality of touch. In this theme issue, we look at active touch across a broad range of species from insects, terrestrial and marine mammals, through to humans. In addition to analysing natural touch, we also consider how engineering is beginning to exploit physical analogues of these biological systems so as to endow robots with rich tactile sensing capabilities. The different contributions show not only the varieties of active touch—antennae, whiskers and fingertips—but also their commonalities. They explore how active touch sensing has evolved in different animal lineages, how it serves to provide rapid and reliable cues for controlling ongoing behaviour, and even how it can disintegrate when our brains begin to fail. They demonstrate that research on active touch offers a means both to understand this essential and primary sensory modality, and to investigate how animals, including man, combine movement with sensing so as to make sense of, and act effectively in, the world. PMID:21969680

FL Activities & Festivals.

ERIC Educational Resources Information Center

American Council on the Teaching of Foreign Languages, Hastings-on-Hudson, NY.

A collection of student, class, and school foreign language activities suggests a variety of projects and describes three specific school efforts. The suggested activities include: (1) individual student efforts such as writing to pen-pals; (2) group activities such as a foreign language auction or sing-along; (3) group projects for the school…

Comparison of laser-activated tissue solders and thrombin-activated cryoprecipitate for wound closure

NASA Astrophysics Data System (ADS)

Kayton, Mark L.; Libutti, Steven K.; Bessler, Marc; Allendorf, John D. F.; Eiref, Simon D.; Marx, Gerard; Mou, Xiaode; Morales, Alfredo M.; Treat, Michael R.; Nowygrod, Roman

1994-09-01

To determine the relative strengths of various biologic adhesives at several timepoints, we compared thrombin-activated SD (solvent-detergent treated) cryoprecipitate with laser- activated SD cryoprecipitate and a laser-activated, albumin-based glue. Male Sprague-Dawley rats (n equals 79) received four, 3-cm, dorsal skin incisions which were closed with either laser- activated cryoprecipitate, laser-activated albumin solder, thrombin-activated cryoprecipitate, or standard skin staples. The cryoprecipitate was derived from pooled human plasma and was treated with a solvent-detergent process, rendering it free of envelope-coated viruses (i.e., HBV, HIV). An 808-nm diode laser was used to activate each solder with an average duration of exposure of 75 seconds per incision. Animals were sacrificed for evaluation of wound tensile strength and histology at 0 hours, 2 hours, 4 hours, and 4 days. At all timepoints tested, laser-activated solders were significantly stronger than thrombin-activated cryoprecipitate (p < 0.03) and control wounds (p < 0.003). There was no significant difference in tensile strength between the two types of laser-activated solder at any timepoint.

Perceiving active listening activates the reward system and improves the impression of relevant experiences.

PubMed

Kawamichi, Hiroaki; Yoshihara, Kazufumi; Sasaki, Akihiro T; Sugawara, Sho K; Tanabe, Hiroki C; Shinohara, Ryoji; Sugisawa, Yuka; Tokutake, Kentaro; Mochizuki, Yukiko; Anme, Tokie; Sadato, Norihiro

2015-01-01

Although active listening is an influential behavior, which can affect the social responses of others, the neural correlates underlying its perception have remained unclear. Sensing active listening in social interactions is accompanied by an improvement in the recollected impressions of relevant experiences and is thought to arouse positive feelings. We therefore hypothesized that the recognition of active listening activates the reward system, and that the emotional appraisal of experiences that had been subject to active listening would be improved. To test these hypotheses, we conducted functional magnetic resonance imaging (fMRI) on participants viewing assessments of their own personal experiences made by evaluators with or without active listening attitude. Subjects rated evaluators who showed active listening more positively. Furthermore, they rated episodes more positively when they were evaluated by individuals showing active listening. Neural activation in the ventral striatum was enhanced by perceiving active listening, suggesting that this was processed as rewarding. It also activated the right anterior insula, representing positive emotional reappraisal processes. Furthermore, the mentalizing network was activated when participants were being evaluated, irrespective of active listening behavior. Therefore, perceiving active listening appeared to result in positive emotional appraisal and to invoke mental state attribution to the active listener.

Perceiving active listening activates the reward system and improves the impression of relevant experiences

PubMed Central

Kawamichi, Hiroaki; Yoshihara, Kazufumi; Sasaki, Akihiro T.; Sugawara, Sho K.; Tanabe, Hiroki C.; Shinohara, Ryoji; Sugisawa, Yuka; Tokutake, Kentaro; Mochizuki, Yukiko; Anme, Tokie; Sadato, Norihiro

2015-01-01

Although active listening is an influential behavior, which can affect the social responses of others, the neural correlates underlying its perception have remained unclear. Sensing active listening in social interactions is accompanied by an improvement in the recollected impressions of relevant experiences and is thought to arouse positive feelings. We therefore hypothesized that the recognition of active listening activates the reward system, and that the emotional appraisal of experiences that had been subject to active listening would be improved. To test these hypotheses, we conducted functional magnetic resonance imaging (fMRI) on participants viewing assessments of their own personal experiences made by evaluators with or without active listening attitude. Subjects rated evaluators who showed active listening more positively. Furthermore, they rated episodes more positively when they were evaluated by individuals showing active listening. Neural activation in the ventral striatum was enhanced by perceiving active listening, suggesting that this was processed as rewarding. It also activated the right anterior insula, representing positive emotional reappraisal processes. Furthermore, the mentalizing network was activated when participants were being evaluated, irrespective of active listening behavior. Therefore, perceiving active listening appeared to result in positive emotional appraisal and to invoke mental state attribution to the active listener. PMID:25188354

101 Environmental Education Activities. Booklet 5--Science & Social Studies (Interdisciplinary) Activities.

ERIC Educational Resources Information Center

Whitney, Helen, Comp.

Forestry is the main focus of this fifth booklet in the series "101 Environmental Education Activities" by the Upper Mississippi River ECO-Center. Designed for students in the intermediate grades and junior high school, the booklet contains 9 science and social studies activities and 5 interdisciplinary activities. Most activity…

Cultural Activation of Consumers.

PubMed

Siegel, Carole E; Reid-Rose, Lenora; Joseph, Adriana M; Hernandez, Jennifer C; Haugland, Gary

2016-02-01

This column discusses "cultural activation," defined as a consumer's recognition of the importance of providing cultural information to providers about cultural affiliations, challenges, views about, and attitudes toward behavioral health and general medical health care, as well as the consumer's confidence in his or her ability to provide this information. An aid to activation, "Cultural Activation Prompts," and a scale that measures a consumer's level of activation, the Cultural Activation Measurement Scale, are described. Suggestions are made about ways to introduce cultural activation as a component of usual care.

TRAF6 and Src kinase activity regulates Cot activation by IL-1.

PubMed

Rodríguez, Cristina; Pozo, Maite; Nieto, Elvira; Fernández, Margarita; Alemany, Susana

2006-09-01

Cot is one of the MAP kinase kinase kinases that regulates the ERK1/ERK2 pathway under physiological conditions. Cot is activated by LPS, by inducing its dissociation from the inactive p105 NFkappaB-Cot complex in macrophages. Here, we show that IL-1 promotes a 10-fold increase in endogenous Cot activity and that Cot is the only MAP kinase kinase kinase that activates ERK1/ERK2 in response to this cytokine. Moreover, in cells where the expression of Cot is blocked, IL-1 fails to induce an increase in IL-8 and MIP-1betamRNA levels. The activation of Cot-MKK1-ERK1/ERK2 signalling pathway by IL-1 is dependent on the activity of the transducer protein TRAF6. Most important, IL-1-induced ERK1/ERK2 activation is inhibited by PP1, a known inhibitor of Src tyrosine kinases, but this tyrosine kinase activity is not required for IL-1 to activate other MAP kinases such as p38 and JNK. This Src kinases inhibitor does not block the dissociation and subsequently degradation of Cot in response to IL-1, indicating that other events besides Cot dissociation are required to activate Cot. All these data highlight the specific requirements for activation of the Cot-MKK1-ERK1/ERK2 pathway and provide evidence that Cot controls the functions of IL-1 that are mediated by ERK1/ERK2.