Atlantic Intracoastal Waterway (AIWW) Maintenance Program Evaluation Study.

DTIC Science & Technology

1983-01-01

offset by rising sea levels. Few plant species can withstand the stress imposed by high salinity and daily inundation by tidal waters, and marsh...related to gradients in salinity and elevation. 7 K-e--.2 The wetlands through which the Atlantic intracoastal Water-day passes are fEeding and nursery...with wetland plant species dominated by salt marsh cotdgra-,s (Spartina alterniflora) in saline areas and giant cordgrass (Spar ti:: cynosurrides) in

Development of new sealed bipolar lead-acid battery

NASA Technical Reports Server (NTRS)

Attia, Alan I.; Rowlette, J. J.

1987-01-01

New light weight composite bipolar plates which can withstand the corrosive environment of the lead acid battery have made possible the construction of a sealed bipolar lead acid battery that promises to achieve very high specific power levels and substantially higher energy densities than conventional lead acid batteries. Performance projections based on preliminary experimental results show that the peak specific power of the battery can be as high as 90 kW/kg, and that a specific power of 5 kW/kg can be sustained over several thousand pulses.

The development of a new sealed bipolar lead-acid battery

NASA Technical Reports Server (NTRS)

Attia, A. I.; Rowlette, J. J.

1988-01-01

New light weight composite bipolar plates which can withstand the corrosive environment of the lead acid battery have made possible the construction of a sealed bipolar lead acid battery that promises to achieve very high specific power levels and substantially higher energy densities than conventional lead acid batteries. Performance projections based on preliminary experimental results show that the peak specific power of the battery can be as high as 90 kW/kg, and that a specific power of 5 kW/kg can be sustained over several thousand pulses.

Measurement technology of RF interference current in high current system

NASA Astrophysics Data System (ADS)

Zhao, Zhihua; Li, Jianxuan; Zhang, Xiangming; Zhang, Lei

2018-06-01

Current probe is a detection method commonly used in electromagnetic compatibility. With the development of power electronics technology, the power level of power conversion devices is constantly increasing, and the power current of the electric energy conversion device in the electromagnetic launch system can reach 10kA. Current probe conventionally used in EMC (electromagnetic compatibility) detection cannot meet the test requirements on high current system due to the magnetic saturation problem. The conventional high current sensor is also not suitable for the RF (Radio Frequency) interference current measurement in high current power device due to the high noise level in the output of active amplifier. In this paper, a passive flexible current probe based on Rogowski coil and matching resistance is proposed that can withstand high current and has low noise level, to solve the measurement problems of interference current in high current power converter. And both differential mode and common mode current detection can be easily carried out with the proposed probe because of the probe's flexible structure.

Wide Bandgap Extrinsic Photoconductive Switches

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

Sullivan, James S.

2012-01-20

Photoconductive semiconductor switches (PCSS) have been investigated since the late 1970s. Some devices have been developed that withstand tens of kilovolts and others that switch hundreds of amperes. However, no single device has been developed that can reliably withstand both high voltage and switch high current. Yet, photoconductive switches still hold the promise of reliable high voltage and high current operation with subnanosecond risetimes. Particularly since good quality, bulk, single crystal, wide bandgap semiconductor materials have recently become available. In this chapter we will review the basic operation of PCSS devices, status of PCSS devices and properties of the widemore » bandgap semiconductors 4H-SiC, 6H-SiC and 2H-GaN.« less

Active green wall plant health tolerance to diesel smoke exposure.

PubMed

Paull, Naomi J; Irga, Peter J; Torpy, Fraser R

2018-05-10

Poor air quality is an emerging world-wide problem, with most urban air pollutants arising from vehicular emissions. As such, localized high pollution environments, such as traffic tunnels pose a significant health risk. Phytoremediation, including the use of active (ventilated) green walls or botanical biofilters, is gaining recognition as a potentially effective method for air pollution control. Research to date has tested the capacity of these systems to remove low levels of pollutants from indoor environments. If botanical biofilters are to be used in highly polluted environments, the plants used in these systems must be resilient, however, this idea has received minimal research. Thus, testing was conducted to assess the hardiness of the vegetated component of a botanical biofilter to simulated street level air pollutant exposure. A range of morphological, physiological, and biochemical tests were conducted on 8 common green wall plant species prior to and post 5-week exposure to highly concentrated diesel fuel combustion effluent; as a pilot study to investigate viability in in situ conditions. The results indicated that species within the fig family were the most tolerant species of those assessed. It is likely that species within the fig family can withstand enhanced air pollutant conditions, potentially a result of its leaf morphology and physiology. Other species tested were all moderately tolerant to the pollution treatment. We conclude that most common green wall plant species have the capacity to withstand high pollutant environments, however, extended experimentation is needed to rule out potential long term effects along with potential decreases in filter efficiency from accumulative effects on the substrate. Copyright © 2018 Elsevier Ltd. All rights reserved.

Impact of UV-B exposure on amphibian embryos: linking species physiology and oviposition behaviour

PubMed Central

Palen, Wendy J; Williamson, Craig E; Clauser, Aaron A; Schindler, Daniel E

2005-01-01

Increasing ultraviolet-B radiation (UV-B) has recently captured the attention of ecologists as a key environmental stressor. Certain species may be particularly vulnerable as a result of either high natural exposure to UV-B or limited physiological capacity to withstand it. UV-B sensitivity has been examined at the cellular and individual level for a wide variety of taxa, but estimates of exposure to UV-B in natural systems are lacking and predictions of large-scale impacts are therefore limited. Here, we combine data on the physiological sensitivity to UV-B and patterns of field exposure across sites for embryos of several well-studied US Pacific Northwest amphibian species. We find substantial differences among species' physiological abilities to withstand UV-B and in the level of UV-B exposure of embryos in the field. More specifically, we find that species with the highest physiological sensitivity to UV-B are those with the lowest field exposures as a function of the location of embryos and the UV-B attenuation properties of water at each site. These results also suggest that conclusions made about species' vulnerability to UV-B in the absence of information on field exposures may often be misleading. PMID:16024386

Method of making a quartz resonator

DOEpatents

Vig, John R.; Filler, Raymond L.; Peters, R. Donald; Frank, James M.

1981-01-01

A quartz resonator is made from a chemically polished quartz plate. The plate is placed in an enclosure fitted with at least three mounting clips to receive the plate. The plate is secured to the clips with an electrically conductive adhesive capable of withstanding operation at 350 degrees C. The assembly is cleaned and a metallic electrode deposited onto the plate until the desired frequency is reached. The enclosure is then hermetically sealed. The resulting resonator can consistently withstand extremely high shocks.

Electrical Characterization Laboratory | Energy Systems Integration

Science.gov Websites

the ability of electrical equipment to withstand high-voltage surges and high-current faults. A capability. High-Voltage Characterization The high-voltage characterization hub offers a Class 1, Div 2 lab

The NASA thermionic-conversion (TEC-ART) program

NASA Technical Reports Server (NTRS)

Morris, J. F.

1977-01-01

The current emphasis is on out-of-core thermionic conversion (TEC). The additional degrees of freedom offer new potentialities, but high-temperature material effects determine the level and lifetime of TEC performance: New electrodes not only raise power outputs but also maintain them regardless of emitter-vapor deposition on collectors. In addition, effective electrodes serve compatibly with hot-shell alloys. Space TEC withstands external and internal high-temperature vaporization problems, and terrestrial TEC tolerates hot corrosive atmospheres outside and near-vacuum inside. Finally, reduction of losses between converter electrodes is essential even though rather demanding geometries appear to be required for some modes of enhanced operation.

Synergies Between ' and Cavity Formation in HT-9 Following High Dose Neutron Irradiation

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

Field, Kevin G.; Parish, Chad M.; Saleh, Tarik A.

Candidate cladding materials for advanced nuclear power reactors including fast reactor designs require materials capable of withstanding high dose neutron irradiation at elevated temperatures. One candidate material, HT-9, through various research programs have demonstrated the ability to withstand significant swelling and other radiation-induced degradation mechanisms in the high dose regime (>50 displacements per atom, dpa) at elevated temperatures (>300 C). Here, high efficiency multi-dimensional scanning transmission electron microscopy (STEM) acquisition with the aid of a three-dimensional (3D) reconstruction and modeling technique is used to probe the microstructural features that contribute to the exceptional swelling resistance of HT-9. In particular, themore » synergies between ' and fine-scale and moderate-scale cavity formation is investigated.« less

Report on Transport and Loading of Explosives in the Femtosecond Tank, Room 1711A HEAF 00-010

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

Hill, D L

2002-04-25

The current OSP associated with Room 1711A located in Building 191 (HEAF) sets a limit of 5 grams Net Explosive Weight (NEW) of explosives for the room. A question was raised as to the capability of that room to withstand the overpressure created by a detonation of 5 grams NEW of explosives. Calculations were inconclusive, but indicated the wallboard would not remain intact if there was a detonation of 5 grams NEW at a distance of eight feet from the wall. These calculations did not seem logical. To verify the hypothesis, a series of experiments were conducted in the 1more » Kilogram tank. The experiments consisted of exposing a pre-built double-sided wall with the same stud spacing and drywall thickness found in the walls of Room 1711A to various amounts of explosives to create expected overpressures. The objective of this test was to prove or disprove that the walls in room 1711A could withstand a detonation of 5 grams of high explosives and to determine if larger quantities of explosives could be worked on in the room while still providing the required level of protection for personnel outside the room. Testing has verified that not only can the walls withstand a 5 gram explosion, but a 10.75 gram explosion as well. A second test was conducted using 20 grams of explosive plus a detonator. Although the inner piece of drywall cracked, the outer piece of drywall maintained its integrity, thereby confining the effects of the anticipated overpressure to the room.« less

New adhesive withstands temperature extremes

NASA Technical Reports Server (NTRS)

Park, J. J.; Seidenberg, B.

1978-01-01

Adhesive, developed for high-temperature components aboard satellites, is useful at both high and low temperatures and exhibits low-vacuum volatility and low shrinkage. System uses polyfunctional epoxy with high aromatic content, low equivalent weight, and more compact polymer than conventional bisphenol A tape.

Design of high pressure oxygen filter for extravehicular activity life support system, volume 1

NASA Technical Reports Server (NTRS)

Wilson, B. A.

1977-01-01

The experience of the National Aeronautics and Space Administration (NASA) with extravehicular activity life support emergency oxygen supply subsystems has shown a large number of problems associated with particulate contamination. These problems have resulted in failures of high pressure oxygen component sealing surfaces. A high pressure oxygen filter was designed which would (a) control the particulate contamination level in the oxygen system to a five-micron glass bead rating, ten-micron absolute condition (b) withstand the dynamic shock condition resulting from the sudden opening of 8000 psi oxygen system shutoff valve. Results of the following program tasks are reported: (1) contaminant source identification tests, (2) dynamic system tests, (3) high pressure oxygen filter concept evaluation, (4) design, (5) fabrication, (6) test, and (7) application demonstration.

High Temperature Structural Foam

NASA Technical Reports Server (NTRS)

Weiser, Erik S.; Baillif, Faye F.; Grimsley, Brian W.; Marchello, Joseph M.

1997-01-01

The Aerospace Industry is experiencing growing demand for high performance polymer foam. The X-33 program needs structural foam insulation capable of retaining its strength over a wide range of environmental conditions. The High Speed Research Program has a need for low density core splice and potting materials. This paper reviews the state of the art in foam materials and describes experimental work to fabricate low density, high shear strength foam which can withstand temperatures from -220 C to 220 C. Commercially available polymer foams exhibit a wide range of physical properties. Some with densities as low as 0.066 g/cc are capable of co-curing at temperatures as high as 182 C. Rohacell foams can be resin transfer molded at temperatures up to 180 C. They have moduli of elasticity of 0.19 MPa, tensile strengths of 3.7 Mpa and compressive strengths of 3.6 MPa. The Rohacell foams cannot withstand liquid hydrogen temperatures, however Imi-Tech markets Solimide (trademark) foams which withstand temperatures from -250 C to 200 C, but they do not have the required structural integrity. The research activity at NASA Langley Research Center focuses on using chemical blowing agents to produce polyimide thermoplastic foams capable of meeting the above performance requirements. The combination of blowing agents that decompose at the minimum melt viscosity temperature together with plasticizers to lower the viscosity has been used to produce foams by both extrusion and oven heating. The foams produced exhibit good environmental stability while maintaining structural properties.

Transistor screening evaluation SJ6708H

NASA Technical Reports Server (NTRS)

Barton, J. L.

1978-01-01

A manufacturer was contracted to screen 125 transistors capable of withstanding the high level inductive voltages obtained when switching inductive loads. Planned differences included a change in die bonding to comply with NASA's desire for hard solder die attachment which further necessitated a change in package to conform to the required die mounting system. Evaluation of the electrical performance and recommended changes were made during the preliminary build phase of the program. The following sections are outlined: (1) narrative outline; (2) customer data summary and X-ray reports; (3) device specification; (4) failure analysis reports; (5) test facilities list; and (6) test measurement data.

Apparatus, components and operating methods for circulating fluidized bed transport gasifiers and reactors

DOEpatents

Vimalchand, Pannalal; Liu, Guohai; Peng, Wan Wang

2015-02-24

The improvements proposed in this invention provide a reliable apparatus and method to gasify low rank coals in a class of pressurized circulating fluidized bed reactors termed "transport gasifier." The embodiments overcome a number of operability and reliability problems with existing gasifiers. The systems and methods address issues related to distribution of gasification agent without the use of internals, management of heat release to avoid any agglomeration and clinker formation, specific design of bends to withstand the highly erosive environment due to high solid particles circulation rates, design of a standpipe cyclone to withstand high temperature gasification environment, compact design of seal-leg that can handle high mass solids flux, design of nozzles that eliminate plugging, uniform aeration of large diameter Standpipe, oxidant injection at the cyclone exits to effectively modulate gasifier exit temperature and reduction in overall height of the gasifier with a modified non-mechanical valve.

High energy forming facility

NASA Technical Reports Server (NTRS)

Ciurlionis, B.

1967-01-01

Watertight, high-explosive forming facility, 25 feet in diameter and 15 feet deep, withstands repeated explosions of 10 pounds of TNT equivalent. The shell is fabricated of high strength steel and allows various structural elements to deform or move elastically and independently while retaining structural integrity.

Development of integral covers on solar cells

NASA Technical Reports Server (NTRS)

Stella, P.; Somberg, H.

1971-01-01

The electron-beam technique for evaporating a dielectric material onto solar cells is investigated. A process has been developed which will provide a highly transparent, low stress, 2 mil thick cover capable of withstanding conventional space type qualification tests including humidity, thermal shock, and thermal cycling. The covers have demonstrated the ability to withstand 10 to the 15th power 1 MeV electrons and UV irradiation with minor darkening. Investigation of the cell AR coating has produced a space qualifiable titanium oxide coating which will give an additional 6% current output over similar silicon oxide coated cells when covered by glass.

49 CFR 399.207 - Truck and truck-tractor access requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... requirements: (1) Vertical height. All measurements of vertical height shall be made from ground level with the... vertical height of the first step shall be no more than 609 millimeters (24 inches) from ground level. (3... requirement. The step need not retain the disc at rest. (5) Step strength. Each step must withstand a vertical...

49 CFR 399.207 - Truck and truck-tractor access requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... requirements: (1) Vertical height. All measurements of vertical height shall be made from ground level with the... vertical height of the first step shall be no more than 609 millimeters (24 inches) from ground level. (3... requirement. The step need not retain the disc at rest. (5) Step strength. Each step must withstand a vertical...

49 CFR 399.207 - Truck and truck-tractor access requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... requirements: (1) Vertical height. All measurements of vertical height shall be made from ground level with the... vertical height of the first step shall be no more than 609 millimeters (24 inches) from ground level. (3... requirement. The step need not retain the disc at rest. (5) Step strength. Each step must withstand a vertical...

49 CFR 399.207 - Truck and truck-tractor access requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... requirements: (1) Vertical height. All measurements of vertical height shall be made from ground level with the... vertical height of the first step shall be no more than 609 millimeters (24 inches) from ground level. (3... requirement. The step need not retain the disc at rest. (5) Step strength. Each step must withstand a vertical...

Performance Specification for the Battery Monitoring System of the Program Executive Office Ground Combat Systems (PEO GCS)

DTIC Science & Technology

2009-10-26

14 3.3.4 Dielectric Withstanding Voltage and Insulation Resistance. ............................. 14...Grounding. .................................................................................................. 32 4.6.2.3 Dielectric Withstanding Voltage ...shall accommodate a non-painted 0.38” 8-32 screw. 3.3.4 Dielectric Withstanding Voltage and Insulation Resistance. Electrical connections

14 CFR 27.1461 - Equipment containing high energy rotors.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Equipment containing high energy rotors. 27... Equipment containing high energy rotors. (a) Equipment containing high energy rotors must meet paragraph (b), (c), or (d) of this section. (b) High energy rotors contained in equipment must be able to withstand...

14 CFR 27.1461 - Equipment containing high energy rotors.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Equipment containing high energy rotors. 27... Equipment containing high energy rotors. (a) Equipment containing high energy rotors must meet paragraph (b), (c), or (d) of this section. (b) High energy rotors contained in equipment must be able to withstand...

14 CFR 27.1461 - Equipment containing high energy rotors.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Equipment containing high energy rotors. 27... Equipment containing high energy rotors. (a) Equipment containing high energy rotors must meet paragraph (b), (c), or (d) of this section. (b) High energy rotors contained in equipment must be able to withstand...

14 CFR 27.1461 - Equipment containing high energy rotors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Equipment containing high energy rotors. 27... Equipment containing high energy rotors. (a) Equipment containing high energy rotors must meet paragraph (b), (c), or (d) of this section. (b) High energy rotors contained in equipment must be able to withstand...

14 CFR 27.1461 - Equipment containing high energy rotors.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Equipment containing high energy rotors. 27... Equipment containing high energy rotors. (a) Equipment containing high energy rotors must meet paragraph (b), (c), or (d) of this section. (b) High energy rotors contained in equipment must be able to withstand...

High temperature lightweight foamed cements

DOEpatents

Sugama, Toshifumi

1989-01-01

Cement slurries are disclosed which are suitable for use in geothermal wells since they can withstand high temperatures and high pressures. The formulation consists of cement, silica flour, water, a retarder, a foaming agent, a foam stabilizer, and a reinforcing agent. A process for producing these cements is also disclosed.

Performance of high performance concrete (HPC) in low pH and sulfate environment : [technical summary].

DOT National Transportation Integrated Search

2013-01-01

High-performance concrete (HPC) refers to any concrete formulation with enhanced characteristics, compared to normal concrete. One might think this refers to strength, but in Florida, the HPC standard emphasizes withstanding aggressive environments, ...

Erosion tests of materials by energetic particle beams

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

Schechter, D.E.; Tsai, C.C.; Sluss, F.

1985-01-01

The internal components of magnetic fusion devices must withstand erosion from and high heat flux of energetic plasma particles. The selection of materials for the construction of these components is important to minimize contamination of the plasma. In order to study various materials' comparative resistance to erosion by energetic particles and their ability to withstand high heat flux, water-cooled copper swirl tubes coated or armored with various materials were subjected to bombardment by hydrogen and helium particle beams. Materials tested were graphite, titanium carbide (TiC), chromium, nickel, copper, silver, gold, and aluminum. Details of the experimental arrangement and methods ofmore » application or attachment of the materials to the copper swirl tubes are presented. Results including survivability and mass losses are discussed.« less

High-Temperature Adhesives for Thermally Stable Aero-Assist Technologies

NASA Technical Reports Server (NTRS)

Eberts, Kenneth; Ou, Runqing

2013-01-01

Aero-assist technologies are used to control the velocity of exploration vehicles (EVs) when entering Earth or other planetary atmospheres. Since entry of EVs in planetary atmospheres results in significant heating, thermally stable aero-assist technologies are required to avoid the high heating rates while maintaining low mass. Polymer adhesives are used in aero-assist structures because of the need for high flexibility and good bonding between layers of polymer films or fabrics. However, current polymer adhesives cannot withstand temperatures above 400 C. This innovation utilizes nanotechnology capabilities to address this need, leading to the development of high-temperature adhesives that exhibit high thermal conductivity in addition to increased thermal decomposition temperature. Enhanced thermal conductivity will help to dissipate heat quickly and effectively to avoid temperature rising to harmful levels. This, together with increased thermal decomposition temperature, will enable the adhesives to sustain transient high-temperature conditions.

Using Large-Eddy Simulations to Define Spectral and Coherence Characteristics of the Hurricane Boundary Layer for Wind-Energy Applications

NASA Astrophysics Data System (ADS)

Worsnop, Rochelle P.; Bryan, George H.; Lundquist, Julie K.; Zhang, Jun A.

2017-10-01

Offshore wind-energy development is planned for regions where hurricanes commonly occur, such as the USA Atlantic Coast. Even the most robust wind-turbine design (IEC Class I) may be unable to withstand a Category-2 hurricane (hub-height wind speeds >50 m s^{-1}). Characteristics of the hurricane boundary layer that affect the structural integrity of turbines, especially in major hurricanes, are poorly understood, primarily due to a lack of adequate observations that span typical turbine heights (<200 m above sea level). To provide these data, we use large-eddy simulations to produce wind profiles of an idealized Category-5 hurricane at high spatial (10 m) and temporal (0.1 s) resolution. By comparison with unique flight-level observations from a field project, we find that a relatively simple configuration of the Cloud Model I model accurately represents the properties of Hurricane Isabel (2003) in terms of mean wind speeds, wind-speed variances, and power spectra. Comparisons of power spectra and coherence curves derived from our hurricane simulations to those used in current turbine design standards suggest that adjustments to these standards may be needed to capture characteristics of turbulence seen within the simulated hurricane boundary layer. To enable improved design standards for wind turbines to withstand hurricanes, we suggest modifications to account for shifts in peak power to higher frequencies and greater spectral coherence at large separations.

Using Large-Eddy Simulations to Define Spectral and Coherence Characteristics of the Hurricane Boundary Layer for Wind-Energy Applications

DOE PAGES

Worsnop, Rochelle P.; Bryan, George H.; Lundquist, Julie K.; ...

2017-06-08

Offshore wind-energy development is planned for regions where hurricanes commonly occur, such as the USA Atlantic Coast. Even the most robust wind-turbine design (IEC Class I) may be unable to withstand a Category-2 hurricane (hub-height wind speeds >50 m s -1). Characteristics of the hurricane boundary layer that affect the structural integrity of turbines, especially in major hurricanes, are poorly understood, primarily due to a lack of adequate observations that span typical turbine heights (<200 m above sea level). To provide these data, we use large-eddy simulations to produce wind profiles of an idealized Category-5 hurricane at high spatial (10more » m) and temporal (0.1 s) resolution. By comparison with unique flight-level observations from a field project, we find that a relatively simple configuration of the Cloud Model I model accurately represents the properties of Hurricane Isabel (2003) in terms of mean wind speeds, wind-speed variances, and power spectra. Comparisons of power spectra and coherence curves derived from our hurricane simulations to those used in current turbine design standards suggest that adjustments to these standards may be needed to capture characteristics of turbulence seen within the simulated hurricane boundary layer. To enable improved design standards for wind turbines to withstand hurricanes, we suggest modifications to account for shifts in peak power to higher frequencies and greater spectral coherence at large separations.« less

Using Large-Eddy Simulations to Define Spectral and Coherence Characteristics of the Hurricane Boundary Layer for Wind-Energy Applications

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

Worsnop, Rochelle P.; Bryan, George H.; Lundquist, Julie K.

Offshore wind-energy development is planned for regions where hurricanes commonly occur, such as the USA Atlantic Coast. Even the most robust wind-turbine design (IEC Class I) may be unable to withstand a Category-2 hurricane (hub-height wind speeds >50 m s -1). Characteristics of the hurricane boundary layer that affect the structural integrity of turbines, especially in major hurricanes, are poorly understood, primarily due to a lack of adequate observations that span typical turbine heights (<200 m above sea level). To provide these data, we use large-eddy simulations to produce wind profiles of an idealized Category-5 hurricane at high spatial (10more » m) and temporal (0.1 s) resolution. By comparison with unique flight-level observations from a field project, we find that a relatively simple configuration of the Cloud Model I model accurately represents the properties of Hurricane Isabel (2003) in terms of mean wind speeds, wind-speed variances, and power spectra. Comparisons of power spectra and coherence curves derived from our hurricane simulations to those used in current turbine design standards suggest that adjustments to these standards may be needed to capture characteristics of turbulence seen within the simulated hurricane boundary layer. To enable improved design standards for wind turbines to withstand hurricanes, we suggest modifications to account for shifts in peak power to higher frequencies and greater spectral coherence at large separations.« less

High temperature lightweight foamed cements

DOEpatents

Sugama, Toshifumi.

1989-10-03

Cement slurries are disclosed which are suitable for use in geothermal wells since they can withstand high temperatures and high pressures. The formulation consists of cement, silica flour, water, a retarder, a foaming agent, a foam stabilizer, and a reinforcing agent. A process for producing these cements is also disclosed. 3 figs.

Adapter assembly prevents damage to tubing during high pressure tests

NASA Technical Reports Server (NTRS)

Stinett, L. L.

1965-01-01

Portable adapter assembly prevents damage to tubing and injury to personnel when pressurizing a system or during high pressure tests. The assembly is capable of withstanding high pressure. It is securely attached to the tubing stub end and may be removed without brazing, cutting or cleaning the tube.

Modeling the Mechanical Behavior of Ceramic Matrix Composite Materials

NASA Technical Reports Server (NTRS)

Jordan, William

1998-01-01

Ceramic matrix composites are ceramic materials, such as SiC, that have been reinforced by high strength fibers, such as carbon. Designers are interested in using ceramic matrix composites because they have the capability of withstanding significant loads while at relatively high temperatures (in excess of 1,000 C). Ceramic matrix composites retain the ceramic materials ability to withstand high temperatures, but also possess a much greater ductility and toughness. Their high strength and medium toughness is what makes them of so much interest to the aerospace community. This work concentrated on two different tasks. The first task was to do an extensive literature search into the mechanical behavior of ceramic matrix composite materials. This report contains the results of this task. The second task was to use this understanding to help interpret the ceramic matrix composite mechanical test results that had already been obtained by NASA. Since the specific details of these test results are subject to the International Traffic in Arms Regulations (ITAR), they are reported in a separate document (Jordan, 1997).

Cork is used to make tooling patterns and molds

NASA Technical Reports Server (NTRS)

Hoffman, F. J.

1965-01-01

Sheet and waste cork are cemented together to provide a tooling pattern or mold. The cork form withstands moderately high temperatures under vacuum or pressure with minimum expansion, shrinkage, or distortion.

Aluminum-titanium hydride-boron carbide composite provides lightweight neutron shield material

NASA Technical Reports Server (NTRS)

Poindexter, A. M.

1967-01-01

Inexpensive lightweight neutron shield material has high strength and ductility and withstands high internal heat generation rates without excessive thermal stress. This composite material combines structural and thermal properties of aluminum, neutron moderating properties of titanium hydride, and neutron absorbing characteristics of boron carbide.

76 FR 38074 - Airworthiness Directives; The Boeing Company Model 747-100, 747-100B, 747-200B, 747-200C, 747...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-29

... withstand fail-safe loads. DATES: We must receive comments on this proposed AD by August 15, 2011. ADDRESSES... pressurization and the inability of the airplane fuselage to withstand fail-safe loads. Actions Since Existing AD... withstand fail-safe loads. Compliance (f) You are responsible for having the actions required by this AD...

The development of enabling technologies for producing active interrogation beams.

PubMed

Kwan, Thomas J T; Morgado, Richard E; Wang, Tai-Sen F; Vodolaga, B; Terekhin, V; Onischenko, L M; Vorozhtsov, S B; Samsonov, E V; Vorozhtsov, A S; Alenitsky, Yu G; Perpelkin, E E; Glazov, A A; Novikov, D L; Parkhomchuk, V; Reva, V; Vostrikov, V; Mashinin, V A; Fedotov, S N; Minayev, S A

2010-10-01

A U.S./Russian collaboration of accelerator scientists was directed to the development of high averaged-current (∼1 mA) and high-quality (emittance ∼15 πmm mrad; energy spread ∼0.1%) 1.75 MeV proton beams to produce active interrogation beams that could be applied to counterterrorism. Several accelerator technologies were investigated. These included an electrostatic tandem accelerator of novel design, a compact cyclotron, and a storage ring with energy compensation and electron cooling. Production targets capable of withstanding the beam power levels were designed, fabricated, and tested. The cyclotron/storage-ring system was theoretically studied and computationally designed, and the electrostatic vacuum tandem accelerator at BINP was demonstrated for its potential in active interrogation of explosives and special nuclear materials.

Light-intensity modulator withstands high heat fluxes

NASA Technical Reports Server (NTRS)

Maples, H. G.; Strass, H. K.

1966-01-01

Mechanism modulates and controls the intensity of luminous radiation in light beams associated with high-intensity heat flux. This modulator incorporates two fluid-cooled, externally grooved, contracting metal cylinders which when rotated about their longitudinal axes present a circular aperture of varying size depending on the degree of rotation.

9 CFR 93.106 - Quarantine requirements.

Code of Federal Regulations, 2010 CFR

2010-01-01

... FOR MEANS OF CONVEYANCE AND SHIPPING CONTAINERS Birds § 93.106 Quarantine requirements. (a) Birds... withstand continued cleaning and disinfection. All walls of the sun room must be at least 8 feet high. (1... high, impermeable to water, and able to prevent the escape of water, manure, and debris. (2) The sun...

Can plant-natural enemy communication withstand disruption by biotic and abiotic factors?

PubMed

Clavijo McCormick, Andrea

2016-12-01

The attraction of natural enemies towards herbivore-induced plant volatiles is a well-documented phenomenon. However, the majority of published studies are carried under optimal water and nutrient regimes and with just one herbivore. But what happens when additional levels of ecological complexity are added? Does the presence of a second herbivore, microorganisms, and abiotic stress interfere with plant-natural enemy communication? or is communication stable enough to withstand disruption by additional biotic and abiotic factors?Investigating the effects of these additional levels of ecological complexity is key to understanding the stability of tritrophic interactions in natural ecosystems and may aid to forecast the impact of environmental disturbances on these, especially in climate change scenarios, which are often associated with modifications in plant and arthropod species distribution and increased levels of abiotic stress.This review explores the literature on natural enemy attraction to herbivore-induced volatiles when, besides herbivory, plants are challenged by additional biotic and abiotic factors.The aim of this review was to establish the impact of different biotic and abiotic factors on plant-natural enemy communication and to highlight critical aspects to guide future research efforts.

Convergent evolution of plant and animal embryo defences by hyperstable non-digestible storage proteins.

PubMed

Pasquevich, María Yanina; Dreon, Marcos Sebastián; Qiu, Jian-Wen; Mu, Huawei; Heras, Horacio

2017-11-20

Plants have evolved sophisticated embryo defences by kinetically-stable non-digestible storage proteins that lower the nutritional value of seeds, a strategy that have not been reported in animals. To further understand antinutritive defences in animals, we analysed PmPV1, massively accumulated in the eggs of the gastropod Pomacea maculata, focusing on how its structure and structural stability features affected its capacity to withstand passage through predator guts. The native protein withstands >50 min boiling and resists the denaturing detergent sodium dodecyl sulphate (SDS), indicating an unusually high structural stability (i.e., kinetic stability). PmPV1 is highly resistant to in vitro proteinase digestion and displays structural stability between pH 2.0-12.0 and 25-85 °C. Furthermore, PmPV1 withstands in vitro and mice digestion and is recovered unchanged in faeces, supporting an antinutritive defensive function. Subunit sequence similarities suggest a common origin and tolerance to mutations. This is the first known animal genus that, like plant seeds, lowers the nutritional value of eggs by kinetically-stable non-digestible storage proteins that survive the gut of predators unaffected. The selective pressure of the harsh gastrointestinal environment would have favoured their appearance, extending by convergent evolution the presence of plant-like hyperstable antinutritive proteins to unattended reproductive stages in animals.

Vibrational Properties of Zr(Hf)B2-SiC UHTC Composites by Micro-Raman Spectroscopy

NASA Astrophysics Data System (ADS)

Donohue, M.; Carpenter, C.; Orlovskaya, N.

Development and characterization of novel materials that are lightweight, possess high mechanical properties, can withstand high temperatures, and provide superior thermal properties are crucial to meet the future demands of Air Force, Army, Navy, Missile Defense Agency (MDA), and other military and space agencies. Materials for such applications (hypersonic air-breathing vehicles, including Single-To-Orbit vehicles and Two-Stage-To-Orbit aerospace planes, fully reusable space transport vehicles, hypersonic cruise missiles) experience severe aero-thermal loads with nose-cone and nozzle temperatures in excess of 2,000°F and 4,000°F, respectively. High G acceleration is also a problem. Even the most advanced materials, such as Ti, Inconel X, carbon-carbon, and silicon carbide based composites cannot withstand the excessive heat generated, especially during re-entry, and they cannot meet the guidelines for future high performance aircrafts, kinetic energy interceptors and reusable space planes. Thus, the demand for low-cost, light weight high temperature materials for thermal protection systems (TPS) is expected to be on the significant rise in the near future.

An Assessment of Air Force Logistics Command’s Part Replication Program

DTIC Science & Technology

1987-09-01

ploycarabonates, ploysulfones, ployimides, and ploybenzimidazoles (Moseley, 1986:49). Thermoplastics derived from the condensation polymerization of...withstand a variety of harsh environments. Amoco’s Torlon is a ploymide-containing aromatic condensation polymer . It has such a high temperature...under conditions of both high temperature and high moisture (Moseley, 1986:51). Thermoplastics made out of polymer fibers have high strength

Producing Fe-W-Co-Cr-C Alloy Cutting Tool Material Through Powder Metallurgy Route

NASA Astrophysics Data System (ADS)

Datta Banik, Bibhas; Dutta, Debasish; Ray, Siddhartha

2017-04-01

High speed steel tools can withstand high impact forces as they are tough in nature. But they cannot retain their hardness at elevated temperature i.e. their hot hardness is low. Therefore permissible cutting speed is low and tools wear out easily. Use of lubricants is essential for HSS cutting tools. On the other hand cemented carbide tools can withstand greater compressive force, but due to lower toughness the tool can break easily. Moreover the cost of the tool is comparatively high. To achieve a better machining economy, Fe-W-Co-Cr-C alloys are being used nowadays. Their toughness is as good as HSS tools and hardness is very near to carbide tools. Even, at moderate cutting speeds they can be safely used in old machines having vibration. Moreover it is much cheaper than carbide tools. This paper highlights the Manufacturing Technology of the alloy and studies the comparative tribological properties of the alloy and tungsten mono carbide.

Steady State Structural Analysis of High Pressure Gas Turbine Blade using Finite Element Analysis

NASA Astrophysics Data System (ADS)

Mazarbhuiya, Hussain Mahamed Sahed Mostafa; Murari Pandey, Krishna

2017-08-01

In gas turbines the major portion of performance dependency lies upon turbine blade design. Turbine blades experience very high centrifugal, axial and tangential force during power generation. While withstanding these forces blades undergo elongation. Different methods have proposed for better enhancement of the mechanical properties of blade to withstand in extreme condition. Present paper describes the stress and elongation for blades having properties of different materials. Steady state structural analysis have performed in the present work for different materials (In 625, In 718, In 738, In 738 LC, MAR M246, Ni-Cr, Ti-alloy, Ti-Al, Ti-T6, U500). Remarkable finding is that the root of the blade is subjected to maximum stress for all blade materials and the blade made of MAR M246 has less stress and deformation among all other blade materials which can be selected as a suitable material for gas turbine blade.

Random vibration (stress screening) of printed wiring assemblies

NASA Technical Reports Server (NTRS)

Bastien, Gilbert J.

1988-01-01

The results of a random vibration test screening (RVSS) study of the determination of the upper and lower vibration limits on printed wiring assemblies (PWA) are summarized. The study results are intended to serve as a guide for engineers and designers who make decisions on PWA features that need to withstand the stresses of dynamic testing and screening. The maximum allowable PWA deflection, G levels, and PSD levels are compared to the expected or actual levels to determine if deleterious effects will occur.

Surface disinfection challenges for Candida auris: an in-vitro study.

PubMed

Kean, R; Sherry, L; Townsend, E; McKloud, E; Short, B; Akinbobola, A; Mackay, W G; Williams, C; Jones, B L; Ramage, G

2018-04-01

The emerging pathogenic multidrug-resistant yeast Candida auris is an important source of healthcare-associated infections and of growing global clinical concern. The ability of this organism to survive on surfaces and withstand environmental stressors creates a challenge for eradicating it from hospitals. A panel of C. auris clinical isolates was evaluated on different surface environments against the standard disinfectant sodium hypochlorite and high-level disinfectant peracetic acid. C. auris was shown to selectively tolerate clinically relevant concentrations of sodium hypochlorite and peracetic acid in a surface-dependent manner, which may explain its ability to successfully persist within the hospital environment. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

10 CFR 60.131 - General design criteria for the geologic repository operations area.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., systems, and components important to safety shall be designed to withstand dynamic effects such as missile... radioactivity areas; and (6) A radiation alarm system to warn of significant increases in radiation levels... system shall be designed with provisions for calibration and for testing its operability. (b) Protection...

JPL in-house fluidized bed reactor research

NASA Technical Reports Server (NTRS)

Rohatgi, N. K.

1985-01-01

The progress in the in-house program on the silane fluidized-bed system is reported. A seed-particle cleaning procedure was developed to obtain material purity near the level required to produce a semiconductor-grade product. The liner-seal design was consistently proven to withstand heating/cooling cycles in all of the experimental runs.

Thermosetting Phthalocyanine Polymers

NASA Technical Reports Server (NTRS)

Fohlen, G.; Parker, J.; Achar, B.

1985-01-01

Group of phthalocyanine polymers resist thermal degradation. Polymers expected semiconducting. Principal applications probably in molded or laminated parts that have to withstand high temperatures. Polymers made from either of two classes of monomer: Bisphthalonitriles with imide linkages or Bisphthalonitriles with ester-imide linkages.

Two-axis movable concentrating solar energy collector

NASA Technical Reports Server (NTRS)

Perkins, G. S.

1977-01-01

Proposed solar-tracker collector assembly with boiler in fixed position, allows use of hard line connections, capable of withstanding optimum high temperature fluid flow. System thereby eliminates need for flexible or slip connection previously used with solar collector systems.

ATLID beam steering mechanism and derived new piezoelectric-based devices for optical applications

NASA Astrophysics Data System (ADS)

Bourgain, F.; Barillot, F.; Belly, C.; Claeyssen, F.

2015-09-01

In Space & Defence (as well as in many others fields), there is a trend for miniaturisation in active optics requiring new actuators. Applications also often require the ability to withstand high vibrations and shocks levels, as well as vacuum compatibility for space applications. A new generation of small and smart actuators such as piezoelectric (piezo) actuators, are resolving this trend, thanks to their capacity to offer high energy density and to support both extreme and various requirements. This paper first presents the BSM mechanism and its requirements, the technologies involved in the design and the validation campaign results. Secondly, a derived XY piezoelectric positioning stage based on the same APA® and associated Strain Gage sensing technology is presented with its associated performances. Finally, a new piezoelectric motor based on the APA® technology, which allows the combination of long stroke while maintaining high resolution positioning of optical elements, is presented with experimental performances.

Development of a 1 kW, 200 C Mapham Inventor

NASA Technical Reports Server (NTRS)

Hammoud, Ahmad; Gerber, Scott; Bauman, Eric; Overton, Eric; Myers, Ira; Bercaw, Robert

1995-01-01

Electronic systems and components are often exposed to high temperature environment in space-based applications, nuclear power facilities, and geothermal energy extraction fields. A key requirement for these systems is, therefore, to withstand the high temperature exposure while maintaining efficient and reliable operation. Efforts were taken to design and develop a high temperature power inverter capable of 200 C operation. A 1 kW, 20 kHz Mapham inverter was designed and evaluated as a function of temperature at different load levels. The inverter system, excluding its input, control, and logic circuits, was characterized at temperatures from ambient to 200 C at 0%, 50%, and 100% resistive loading. With an applied input voltage of 75 VDC, the inverter produced an output of 250 VAC. The results obtained, which indicate good operational characteristics of the inverter up to 200 C, are presented and discussed.

Genetic diversity in peach [Prunus persica (L.) Batsch] at the University of Florida: past present and future

USDA-ARS?s Scientific Manuscript database

The University of Florida (UF) stone fruit breeding and genetics program was created in 1952 to develop early ripening stone fruit cultivars with high quality, adaptation to summer rainfall, low chilling requirements, and the ability to withstand high disease pressure. Diverse germplasm sources were...

High-Temperature Natural Antioxidant Improves Soy Oil for Frying

USDA-ARS?s Scientific Manuscript database

The objectives of this study were to determine the frying stability of soybean oil (SBO) treated with a natural citric acid-based antioxidant, EPT-OILShield able to withstand high temperatures and to establish the oxidative stability of food fried in the treated oil. Soybean oil with 0.05% and 0.5%...

Energy Systems Integration News | Energy Systems Integration Facility |

Science.gov Websites

NREL six people standing at a table with various containers of pet food. NREL's ESI program included with this release. Register for the webinar. Presentations Available from Last Month's High withstand the crucial first minute after severe grid disturbances with high penetrations of wind and solar

Strain tolerant microfilamentary superconducting wire

DOEpatents

Finnemore, D.K.; Miller, T.A.; Ostenson, J.E.; Schwartzkopf, L.A.; Sanders, S.C.

1993-02-23

A strain tolerant microfilamentary wire capable of carrying superconducting currents is provided comprising a plurality of discontinuous filaments formed from a high temperature superconducting material. The discontinuous filaments have a length at least several orders of magnitude greater than the filament diameter and are sufficiently strong while in an amorphous state to withstand compaction. A normal metal is interposed between and binds the discontinuous filaments to form a normal metal matrix capable of withstanding heat treatment for converting the filaments to a superconducting state. The geometry of the filaments within the normal metal matrix provides substantial filament-to-filament overlap, and the normal metal is sufficiently thin to allow supercurrent transfer between the overlapped discontinuous filaments but is also sufficiently thick to provide strain relief to the filaments.

Corrosion-Resistant Ball Bearings

NASA Technical Reports Server (NTRS)

Zdankiewicz, E. M.; Linaburg, E. L.; Lytle, L. J.

1990-01-01

Self-lubricating bearing system withstands highly corrosive environment of wastewater-recycling unit. New bearings contain cobalt-based-alloy balls and races, graphite/polyimide polymer ball cages, and single integral polytetrafluoroethylene seals on wet sides. Materials and design prevent corrosion by acids and provide lubrication.

A Taguchi approach on optimal process control parameters for HDPE pipe extrusion process

NASA Astrophysics Data System (ADS)

Sharma, G. V. S. S.; Rao, R. Umamaheswara; Rao, P. Srinivasa

2017-06-01

High-density polyethylene (HDPE) pipes find versatile applicability for transportation of water, sewage and slurry from one place to another. Hence, these pipes undergo tremendous pressure by the fluid carried. The present work entails the optimization of the withstanding pressure of the HDPE pipes using Taguchi technique. The traditional heuristic methodology stresses on a trial and error approach and relies heavily upon the accumulated experience of the process engineers for determining the optimal process control parameters. This results in setting up of less-than-optimal values. Hence, there arouse a necessity to determine optimal process control parameters for the pipe extrusion process, which can ensure robust pipe quality and process reliability. In the proposed optimization strategy, the design of experiments (DoE) are conducted wherein different control parameter combinations are analyzed by considering multiple setting levels of each control parameter. The concept of signal-to-noise ratio ( S/ N ratio) is applied and ultimately optimum values of process control parameters are obtained as: pushing zone temperature of 166 °C, Dimmer speed at 08 rpm, and Die head temperature to be 192 °C. Confirmation experimental run is also conducted to verify the analysis and research result and values proved to be in synchronization with the main experimental findings and the withstanding pressure showed a significant improvement from 0.60 to 1.004 Mpa.

Manufacturing and test of 2G-HTS coils for rotating machines: Challenges, conductor requirements, realization

NASA Astrophysics Data System (ADS)

Oomen, Marijn; Herkert, Werner; Bayer, Dietmar; Kummeth, Peter; Nick, Wolfgang; Arndt, Tabea

2012-11-01

We investigate the use of 2nd-generation High-Temperature Superconductors (2G-HTSs) in the rotors of electrical motors and generators. For these devices the conductor must be wound into robust impregnated coils, which are operated in vacuum at temperatures around 30 K, in strong magnetic fields of about 2T. Differences in thermal contraction between the coil former, conductor constituents, impregnation resin, bandage and heat-sink materials (assembled at room temperature) cause mechanical stresses at operating temperature. Rotating-machine operation adds Lorentz forces and challenging centripetal accelerations up to thousands of g. Second generation-HTS conductors withstand large tensile stresses in axial direction and compression in normal direction. However, shear stresses, axial compression, and tension normal to the conductor can cause degradation in superconducting properties. Such stresses can be mitigated by correct choice of materials, coil lay-out and manufacturing process. A certain stress level will remain, which the conductor must withstand. We have manufactured many impregnated round and race-track coils, using different 2G-HTS conductors, and tested them at temperatures from 25 K to 77 K. Degradation of the superconductor in early coils was traced to the mentioned differences in thermal contraction, and was completely avoided in coils produced later. We will discuss appropriate coil-winding techniques to assure robust and reliable superconductor performance.

Hierarchically porous materials from layer-by-layer photopolymerization of high internal phase emulsions.

PubMed

Sušec, Maja; Ligon, Samuel Clark; Stampfl, Jürgen; Liska, Robert; Krajnc, Peter

2013-06-13

A combination of high internal phase emulsion (HIPE) templating and additive manufacturing technology (AMT) is applied for creating hierarchical porosity within an acrylate and acrylate/thiol-based polymer network. The photopolymerizable formulation is optimized to produce emulsions with a volume fraction of droplet phase greater than 80 vol%. Kinetic stability of the emulsions is sufficient enough to withstand in-mold curing or computer-controlled layer-by-layer stereolithography without phase separation. By including macroscale cellular cavities within the build file, a level of controlled porosity is created simultaneous to the formation of the porous microstructure of the polyHIPE. The hybrid HIPE-AMT technique thus provides hierarchically porous materials with mechanical properties tailored by the addition of thiol chain transfer agent. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High power RF window deposition apparatus, method, and device

DOEpatents

Ives, Lawrence R.; Lucovsky, Gerald; Zeller, Daniel

2017-07-04

A process for forming a coating for an RF window which has improved secondary electron emission and reduced multipactor for high power RF waveguides is formed from a substrate with low loss tangent and desirable mechanical characteristics. The substrate has an RPAO deposition layer applied which oxygenates the surface of the substrate to remove carbon impurities, thereafter has an RPAN deposition layer applied to nitrogen activate the surface of the substrate, after which a TiN deposition layer is applied using Titanium tert-butoxide. The TiN deposition layer is capped with a final RPAN deposition layer of nitridation to reduce the bound oxygen in the TiN deposition layer. The resulting RF window has greatly improved titanium layer adhesion, reduced multipactor, and is able to withstand greater RF power levels than provided by the prior art.

G-Equivalent Acceleration Tolerance in the Eutardigrade Species Hypsibius dujardini

NASA Astrophysics Data System (ADS)

Vasanthan, Tarushika; Alejaldre, Lorea; Hider, Jessica; Patel, Shreya; Husain, Nabiha; Umapathisivam, Bavithra; Stone, Jonathon

2017-01-01

Tardigrades are microscopic organisms renowned for their ability to survive extreme environmental conditions. Tardigrade extreme-tolerance research has centered on the ability to withstand desiccation, low and high temperatures, and high hydrostatic pressure and radiation levels. Tardigrade tolerance to hypergravity, however, has yet to be described. We used the eutardigrade species Hypsibius dujardini to investigate short-term tolerance to g-equivalent accelerations (i.e., mimicking g-forces). Data obtained from specimens centrifuged between 3421g and 16,060g for 1 min inclusively reveal tolerance in an acceleration-dependent relation, with lower survivorship and egg production at higher accelerations. This is the first study to demonstrate tardigrade potential for tolerance to hypergravity and describe expected effects on tardigrade survival and reproduction. These findings will prove to be useful in lithopanspermia research (i.e., viable spread in meteoritic rocks).

Special features of large-size resistors for high-voltage pulsed installations

NASA Astrophysics Data System (ADS)

Minakova, N. N.; Ushakov, V. Ya.

2017-12-01

Many structural materials in pulsed power engineering operate under extreme conditions. For example, in high-voltage electrophysical installations among which there are multistage high-voltage pulse generators (HVPG), rigid requirements are imposed on characteristics of solid-state resistors that are more promising in comparison with widely used liquid resistors. Materials of such resistors shall be able to withstand strong electric fields, operate at elevated temperatures, in transformer oil, etc. Effective charge of high-voltage capacitors distributed over the HVPG steps (levels) requires uniform voltage distribution along the steps of the installation that can be obtained using large-size resistors. For such applications, polymer composite materials are considered rather promising. They can work in transformer oil and have small mass in comparison with bulky resistors on inorganic basis. This allows technical solutions already developed and implemented in HVPG with liquid resistors to be employed. This paper is devoted to the solution of some tasks related to the application of filled polymers in high-voltage engineering.

Experimental Equipment Design and Fabrication Study for Delta-G Experiment

NASA Technical Reports Server (NTRS)

1997-01-01

The Research Machine Shop at UAH did not develop any new technology in the performance of the following tasks. All tasks were performed as specified.UAH RMS shall design and fabricate a "poor" model of a silicon-carbide high-temperature crucible with dimensions of 8 inches in diameter and 4 inches high-temperature crucible for pouring liquid ceramic materials at 1200 C into molds from heating ovens. The crucible shall also be designed with a manipulation fixture to facilitate holding and pouring of the heated liquid material. UAH RMS shall investigate the availability of 400 Hz, high-current (65 volts @ 100 amperes) power systems for use in high-speed rotating disk experiments, UAH RMS shall investigate, develop a methodology, and experiment on the application of filament-wound carbon fibers to the periphery of ceramic superconductors to withstand high levels of rotational g-forces. UAH RMS shall provide analytical data to verify the resulting improved disc with carbon composite fibers.

Genome interrogation for novel salinity tolerant Arabidopsis mutants.

PubMed

van Tol, Niels; Pinas, Johan; Schat, Henk; Hooykaas, Paul J J; van der Zaal, Bert J

2016-12-01

Soil salinity is becoming an increasingly large problem in agriculture. In this study, we have investigated whether a capacity to withstand salinity can be induced in the salinity sensitive plant species Arabidopsis thaliana, and whether it can be maintained in subsequent generations. To this end, we have used zinc finger artificial transcription factor (ZF-ATFs) mediated genome interrogation. Already within a relatively small collection Arabidopsis lines expressing ZF-ATFs, we found 41 lines that were tolerant to 100 mM NaCl. Furthermore, ZF-ATF encoding gene constructs rescued from the most strongly salinity tolerant lines were indeed found to act as dominant and heritable agents for salinity tolerance. Altogether, our data provide evidence that a silent capacity to withstand normally lethal levels of salinity exists in Arabidopsis and can be evoked relatively easily by in trans acting transcription factors like ZF-ATFs. © 2016 John Wiley & Sons Ltd.

An Overview of Signaling Regulons During Cold Stress Tolerance in Plants

PubMed Central

Pareek, Amit; Khurana, Ashima; Sharma, Arun K.; Kumar, Rahul

2017-01-01

Plants, being sessile organisms, constantly withstand environmental fluctuations, including low-temperature, also referred as cold stress. Whereas cold poses serious challenges at both physiological and developmental levels to plants growing in tropical or sub-tropical regions, plants from temperate climatic regions can withstand chilling or freezing temperatures. Several cold inducible genes have already been isolated and used in transgenic approach to generate cold tolerant plants. The conventional breeding methods and marker assisted selection have helped in developing plant with improved cold tolerance, however, the development of freezing tolerant plants through cold acclimation remains an unaccomplished task. Therefore, it is essential to have a clear understanding of how low temperature sensing strategies and corresponding signal transduction act during cold acclimation process. Herein, we synthesize the available information on the molecular mechanisms underlying cold sensing and signaling with an aim that the summarized literature will help develop efficient strategies to obtain cold tolerant plants. PMID:29204079

KSC-04pd1716

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, modules and equipment are being covered in plastic in preparation for the expected impact of Hurricane Frances on Saturday. KSC workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

Solid state thin film battery having a high temperature lithium alloy anode

DOEpatents

Hobson, David O.

1998-01-01

An improved rechargeable thin-film lithium battery involves the provision of a higher melting temperature lithium anode. Lithium is alloyed with a suitable solute element to elevate the melting point of the anode to withstand moderately elevated temperatures.

Natural communities in catch basins in southern Rhode Island

USGS Publications Warehouse

Butler, M.; Ginsberg, H.S.; LeBrun, R.A.; Gettman, A.D.; Pollnak, F.

2007-01-01

Storm-water drainage catch basins are manmade structures that often contain water and organic matter, making them suitable environments for various organisms. We censused organisms inhabiting catch basins in southern Rhode Island in 2002 in an effort to begin to describe these communities. Catch-basin inhabitants were mostly detritivores, including annelids, arthropods, and mollusks that could withstand low oxygen levels and droughts. Our results suggest that catch-basin inhabitants were mostly washed in with rainwater, and populations increased over the summer season as biotic activity resulted in increased nutrient levels later in the summer. In contrast, mosquitoes and other Diptera larvae were abundant earlier in the summer because the adults actively sought catch basins for oviposition sites. Mosquito larvae were likely to be abundant in catch basins with shallow, stagnant water that had relatively low dissolved oxygen and pH, and relatively high total suspended solids, carbon, and nitrogen.

Standardized Laboratory Test Requirements for Hardening Equipment to Withstand Wave Impact Shock in Small High Speed Craft

DTIC Science & Technology

2017-02-06

and methodology for transitioning craft acceleration data to laboratory shock test requirements are summarized and example requirements for...engineering rationale, assumptions, and methodology for transitioning craft acceleration data to laboratory shock test requirements are summarized and... Methodologies for Small High-Speed Craft Structure, Equipment, Shock Isolation Seats, and Human Performance At-Sea, 10 th Symposium on High

Method for producing strain tolerant multifilamentary oxide superconducting wire

DOEpatents

Finnemore, D.K.; Miller, T.A.; Ostenson, J.E.; Schwartzkopf, L.A.; Sanders, S.C.

1994-07-19

A strain tolerant multifilamentary wire capable of carrying superconducting currents is provided comprising a plurality of discontinuous filaments formed from a high temperature superconducting material. The discontinuous filaments have a length at least several orders of magnitude greater than the filament diameter and are sufficiently strong while in an amorphous state to withstand compaction. A normal metal is interposed between and binds the discontinuous filaments to form a normal metal matrix capable of withstanding heat treatment for converting the filaments to a superconducting state. The geometry of the filaments within the normal metal matrix provides substantial filament-to-filament overlap, and the normal metal is sufficiently thin to allow supercurrent transfer between the overlapped discontinuous filaments but is also sufficiently thick to provide strain relief to the filaments. 6 figs.

Method for producing strain tolerant multifilamentary oxide superconducting wire

DOEpatents

Finnemore, Douglas K.; Miller, Theodore A.; Ostenson, Jerome E.; Schwartzkopf, Louis A.; Sanders, Steven C.

1994-07-19

A strain tolerant multifilamentary wire capable of carrying superconducting currents is provided comprising a plurality of discontinuous filaments formed from a high temperature superconducting material. The discontinuous filaments have a length at least several orders of magnitude greater than the filament diameter and are sufficiently strong while in an amorphous state to withstand compaction. A normal metal is interposed between and binds the discontinuous filaments to form a normal metal matrix capable of withstanding heat treatment for converting the filaments to a superconducting state. The geometry of the filaments within the normal metal matrix provides substantial filament-to-filament overlap, and the normal metal is sufficiently thin to allow supercurrent transfer between the overlapped discontinuous filaments but is also sufficiently thick to provide strain relief to the filaments.

Qualification and Testing of Quantum Cascade Lasers for Harsh Environments

NASA Astrophysics Data System (ADS)

Brauer, C. S.; Myers, T. L.; Cannon, B. D.; Anderson, C. G.; Crowther, B. G.; Hansen, S.

2014-12-01

Quantum cascade lasers (QCLs) offer the potential for the development of novel, laser-based instruments for both terrestrial and space applications. In order to withstand harsh conditions encountered in these environments, lasers must be robust, and rigorous testing is required before new systems can be utilized. A particular concern for space applications is the potential damage to laser performance caused by radiation exposure. While the effects of radiation exposure in diode lasers have been studied extensively, the effect on QCLs, which are fundamentally different from diode lasers, is not well known. We thus present work to quantify the performance of QCLs after exposure to moderate and high levels of radiation from different sources, including protons and gamma rays, to determine the effects of radiation damage.

14 CFR 25.875 - Reinforcement near propellers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... strong and stiff enough to withstand the effects of the induced vibration and of ice thrown from the propeller. (b) No window may be near the propeller tips unless it can withstand the most severe ice impact...

14 CFR 25.875 - Reinforcement near propellers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... strong and stiff enough to withstand the effects of the induced vibration and of ice thrown from the propeller. (b) No window may be near the propeller tips unless it can withstand the most severe ice impact...

14 CFR 25.875 - Reinforcement near propellers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... strong and stiff enough to withstand the effects of the induced vibration and of ice thrown from the propeller. (b) No window may be near the propeller tips unless it can withstand the most severe ice impact...

14 CFR 25.875 - Reinforcement near propellers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... strong and stiff enough to withstand the effects of the induced vibration and of ice thrown from the propeller. (b) No window may be near the propeller tips unless it can withstand the most severe ice impact...

14 CFR 25.875 - Reinforcement near propellers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... strong and stiff enough to withstand the effects of the induced vibration and of ice thrown from the propeller. (b) No window may be near the propeller tips unless it can withstand the most severe ice impact...

KSC-04pd1714

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers cover with plastic the Multi-Purpose Logistics Module Donatello in preparation for the expected impact of Hurricane Frances on Saturday. Other modules and equipment are being covered as well. Workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1712

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers cover with plastic the U.S. Node 2 in preparation for the expected impact of Hurricane Frances on Saturday. Other modules and equipment are being covered as well. Workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1713

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, workers cover with plastic the Multi-Purpose Logistics Module Raffaello in preparation for the expected impact of Hurricane Frances on Saturday. Other modules and equipment are being covered as well. Workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1715

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, modules wrapped in plastic line one wall. The modules and equipment are being covered in preparation for the expected impact of Hurricane Frances on Saturday. KSC workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

Solid state thin film battery having a high temperature lithium alloy anode

DOEpatents

Hobson, D.O.

1998-01-06

An improved rechargeable thin-film lithium battery involves the provision of a higher melting temperature lithium anode. Lithium is alloyed with a suitable solute element to elevate the melting point of the anode to withstand moderately elevated temperatures. 2 figs.

Oxidation resistant filler metals for direct brazing of structural ceramics

DOEpatents

Moorhead, Arthur J.

1986-01-01

A method of joining ceramics and metals to themselves and to one another is described using essentially pure trinickel aluminide and trinickel aluminide containing small amounts of carbon. This method produces strong joints that can withstand high service temperatures and oxidizing environments.

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons checks the electroweld he performed on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-16

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons checks the electroweld he performed on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons continues electrowelding on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-16

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons continues electrowelding on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons electrowelds a crack formed in the insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-16

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons electrowelds a crack formed in the insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons prepares to electroweld a crack formed in the insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-16

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons prepares to electroweld a crack formed in the insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons prepares to electroweld a crack found on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-16

KENNEDY SPACE CENTER, FLA. - United Space Alliance employee Anthony Simmons prepares to electroweld a crack found on an insulator inside a Reinforced Carbon Carbon panel. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (right) attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (right) attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (above) attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (above) attaches a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

Polyimide/Glass Composite High-Temperature Insulation

NASA Technical Reports Server (NTRS)

Pater, Ruth H.; Vasquez, Peter; Chatlin, Richard L.; Smith, Donald L.; Skalski, Thomas J.; Johnson, Gary S.; Chu, Sang-Hyon

2009-01-01

Lightweight composites of RP46 polyimide and glass fibers have been found to be useful as extraordinarily fire-resistant electrical-insulation materials. RP46 is a polyimide of the polymerization of monomeric reactants (PMR) type, developed by NASA Langley Research Center. RP46 has properties that make it attractive for use in electrical insulation at high temperatures. These properties include high-temperature resistance, low relative permittivity, low dissipation factor, outstanding mechanical properties, and excellent resistance to moisture and chemicals. Moreover, RP46 contains no halogen or other toxic materials and when burned it does not produce toxic fume or gaseous materials. The U. S. Navy has been seeking lightweight, high-temperature-resistant electrical-insulation materials in a program directed toward reducing fire hazards and weights in ship electrical systems. To satisfy the requirements of this program, an electrical-insulation material must withstand a 3-hour gas-flame test at 1,600 F (about 871 C). Prior to the development reported here, RP46 was rated for use at temperatures from -150 to +700 F (about -101 to 371 C), and no polymeric product - not even RP46 - was expected to withstand the Navy 3-hour gas-flame test.

Evolutionary Strategies of Viruses, Bacteria and Archaea in Hydrothermal Vent Ecosystems Revealed through Metagenomics

PubMed Central

Anderson, Rika E.; Sogin, Mitchell L.; Baross, John A.

2014-01-01

The deep-sea hydrothermal vent habitat hosts a diverse community of archaea and bacteria that withstand extreme fluctuations in environmental conditions. Abundant viruses in these systems, a high proportion of which are lysogenic, must also withstand these environmental extremes. Here, we explore the evolutionary strategies of both microorganisms and viruses in hydrothermal systems through comparative analysis of a cellular and viral metagenome, collected by size fractionation of high temperature fluids from a diffuse flow hydrothermal vent. We detected a high enrichment of mobile elements and proviruses in the cellular fraction relative to microorganisms in other environments. We observed a relatively high abundance of genes related to energy metabolism as well as cofactors and vitamins in the viral fraction compared to the cellular fraction, which suggest encoding of auxiliary metabolic genes on viral genomes. Moreover, the observation of stronger purifying selection in the viral versus cellular gene pool suggests viral strategies that promote prolonged host integration. Our results demonstrate that there is great potential for hydrothermal vent viruses to integrate into hosts, facilitate horizontal gene transfer, and express or transfer genes that manipulate the hosts’ functional capabilities. PMID:25279954

Precast concrete sandwich panels subjected to impact loading

NASA Astrophysics Data System (ADS)

Runge, Matthew W.

Precast concrete sandwich panels are a relatively new product in the construction industry. The design of these panels incorporates properties that allow for great resilience against temperature fluctuation as well as the very rapid and precise construction of facilities. The concrete sandwich panels investigated in this study represent the second generation of an ongoing research and development project. This second generation of panels have been engineered to construct midsized commercial buildings up to three stories in height as well as residential dwellings. The panels consist of a double-tee structural wythe, a foam core and a fascia wythe, joined by shear connectors. Structures constructed from these panels may be subjected to extreme loading including the effects of seismic and blast loading in addition to wind. The aim of this work was to investigate the behaviour of this particular sandwich panel when subjected to structural impact events. The experimental program consisted of fourteen concrete sandwich panels, five of which were considered full-sized specimens (2700 mm X 1200mm X 270 mm) and nine half-sized specimens (2700mm X 600mm X 270 mm) The panels were subjected to impact loads from a pendulum impact hammer where the total energy applied to the panels was varied by changing the mass of the hammer. The applied loads, displacements, accelerations, and strains at the mid-span of the panel as well as the reaction point forces were monitored during the impact. The behaviour of the panels was determined primarily from the experimental results. The applied loads at low energy levels that caused little to no residual deflection as well as the applied loads at high energy levels that represent catastrophic events and thus caused immediate failure were determined from an impact on the structural and the fascia wythes. Applied loads at intermediate energy levels representing extreme events were also used to determine whether or not the panels could withstand multiple impacts. It was shown that panels impacted on the fascia wythe are capable of withstanding multiple impacts of energy levels in excess of 16 000 J while panels that were impacted on the structural wythe are capable of resisting a single impact delivering an energy level of 10 000 J or multiple impacts from an energy level of 5 000 J. A Single Degree of Freedom (SDOF) model was developed to predict the maximum deflection of the panels and it provided a good approximation of the deflection observed during the experimental program. A high degree of composite action between the two wythes was determined to exist from the results of high speed video imaging and through SDOF modelling.

46 CFR 111.05-27 - Grounded neutral alternating current systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... the ground connection, is able to withstand the maximum available fault current without damage, and... 46 Shipping 4 2011-10-01 2011-10-01 false Grounded neutral alternating current systems. 111.05-27... Grounded neutral alternating current systems. Grounded neutral and high-impedance grounded neutral...

46 CFR 111.05-27 - Grounded neutral alternating current systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... the ground connection, is able to withstand the maximum available fault current without damage, and... 46 Shipping 4 2010-10-01 2010-10-01 false Grounded neutral alternating current systems. 111.05-27... Grounded neutral alternating current systems. Grounded neutral and high-impedance grounded neutral...

Lithium target for accelerator based BNCT neutron source: Influence by the proton irradiation on lithium

NASA Astrophysics Data System (ADS)

Fujii, R.; Imahori, Y.; Nakakmura, M.; Takada, M.; Kamada, S.; Hamano, T.; Hoshi, M.; Sato, H.; Itami, J.; Abe, Y.; Fuse, M.

2012-12-01

The neutron source for Boron Neutron Capture Therapy (BNCT) is in the transition stage from nuclear reactor to accelerator based neutron source. Generation of low energy neutron can be achieved by 7Li (p, n) 7Be reaction using accelerator based neutron source. Development of small-scale and safe neutron source is within reach. The melting point of lithium that is used for the target is low, and durability is questioned for an extended use at a high current proton beam. In order to test its durability, we have irradiated lithium with proton beam at the same level as the actual current density, and found no deterioration after 3 hours of continuous irradiation. As a result, it is suggested that lithium target can withstand proton irradiation at high current, confirming suitability as accelerator based neutron source for BNCT.

Evaluation of Ferrite Chip Beads as Surge Current Limiters in Circuits with Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2014-01-01

Limiting resistors are currently required to be connected in series with tantalum capacitors to reduce the risk of surge current failures. However, application of limiting resistors decreases substantially the efficiency of the power supply systems. An ideal surge current limiting device should have a negligible resistance for DC currents and high resistance at frequencies corresponding to transients in tantalum capacitors. This work evaluates the possibility of using chip ferrite beads (FB) as such devices. Twelve types of small size FBs from three manufacturers were used to evaluate their robustness under soldering stresses and at high surge current spikes associated with transients in tantalum capacitors. Results show that FBs are capable to withstand current pulses that are substantially greater than the specified current limits. However, due to a sharp decrease of impedance with current, FBs do not reduce surge currents to the required level that can be achieved with regular resistors.

A digital underwater video camera system for aquatic research in regulated rivers

USGS Publications Warehouse

Martin, Benjamin M.; Irwin, Elise R.

2010-01-01

We designed a digital underwater video camera system to monitor nesting centrarchid behavior in the Tallapoosa River, Alabama, 20 km below a peaking hydropower dam with a highly variable flow regime. Major components of the system included a digital video recorder, multiple underwater cameras, and specially fabricated substrate stakes. The innovative design of the substrate stakes allowed us to effectively observe nesting redbreast sunfish Lepomis auritus in a highly regulated river. Substrate stakes, which were constructed for the specific substratum complex (i.e., sand, gravel, and cobble) identified at our study site, were able to withstand a discharge level of approximately 300 m3/s and allowed us to simultaneously record 10 active nests before and during water releases from the dam. We believe our technique will be valuable for other researchers that work in regulated rivers to quantify behavior of aquatic fauna in response to a discharge disturbance.

G-Equivalent Acceleration Tolerance in the Eutardigrade Species Hypsibius dujardini.

PubMed

Vasanthan, Tarushika; Alejaldre, Lorea; Hider, Jessica; Patel, Shreya; Husain, Nabiha; Umapathisivam, Bavithra; Stone, Jonathon

2017-01-01

Tardigrades are microscopic organisms renowned for their ability to survive extreme environmental conditions. Tardigrade extreme-tolerance research has centered on the ability to withstand desiccation, low and high temperatures, and high hydrostatic pressure and radiation levels. Tardigrade tolerance to hypergravity, however, has yet to be described. We used the eutardigrade species Hypsibius dujardini to investigate short-term tolerance to g-equivalent accelerations (i.e., mimicking g-forces). Data obtained from specimens centrifuged between 3421g and 16,060g for 1 min inclusively reveal tolerance in an acceleration-dependent relation, with lower survivorship and egg production at higher accelerations. This is the first study to demonstrate tardigrade potential for tolerance to hypergravity and describe expected effects on tardigrade survival and reproduction. These findings will prove to be useful in lithopanspermia research (i.e., viable spread in meteoritic rocks). Key Words: Astrobiology-Extreme tolerance-Hypergravity-Tardigrade. Astrobiology 17, 55-60.

Intraspecific variation among Tetranychid mites for ability to detoxify and to induce plant defenses.

PubMed

Ozawa, Rika; Endo, Hiroki; Iijima, Mei; Sugimoto, Koichi; Takabayashi, Junji; Gotoh, Tetsuo; Arimura, Gen-Ichiro

2017-02-27

Two genotypes coexist among Kanzawa spider mites, one of which causes red scars and the other of which causes white scars on leaves, and they elicit different defense responses in host plants. Based on RNA-Seq analysis, we revealed here that the expression levels of genes involved in the detoxification system were higher in Red strains than White strains. The corresponding enzyme activities as well as performances for acaricide resistance and host adaptation toward Laminaceae were also higher in Red strains than White strains, indicating that Red strains were superior in trait(s) of the detox system. In subsequent generations of strains that had survived exposure to fenpyroximate, both strains showed similar resistance to this acaricide, as well as similar detoxification activities. The endogenous levels of salicylic acid and jasmonic acid were increased similarly in bean leaves damaged by original Red strains and their subsequent generations that inherited high detox activity. Jasmonic acid levels were increased in leaves damaged by original White strains, but not by their subsequent generations that inherited high detox activity. Together, these data suggest the existence of intraspecific variation - at least within White strains - with respect to their capacity to withstand acaricides and host plant defenses.

Study of Creep of Alumina-Forming Austenitic Stainless Steel for High-Temperature Energy Applications

NASA Astrophysics Data System (ADS)

Afonina, Natalie Petrovna

To withstand the high temperature (>700°C) and pressure demands of steam turbines and boilers used for energy applications, metal alloys must be economically viable and have the necessary material properties, such as high-temperature creep strength, oxidation and corrosion resistance, to withstand such conditions. One promising class of alloys potentially capable of withstanding the rigors of aggressive environments, are alumina-forming austenitic stainless steels (AFAs) alloyed with aluminum to improve corrosion and oxidation resistance. The effect of aging on the microstructure, high temperature constant-stress creep behavior and mechanical properties of the AFA-type alloy Fe-20Cr-30Ni-2Nb-5Al (at.%) were investigated in this study. The alloy's microstructural evolution with increased aging time was observed prior to creep testing. As aging time increased, the alloy exhibited increasing quantities of fine Fe2Nb Laves phase dispersions, with a precipitate-free zone appearing in samples with higher aging times. The presence of the L1 2 phase gamma'-Ni3Al precipitate was detected in the alloy's matrix at 760°C. A constant-stress creep rig was designed, built and its operation validated. Constant-stress creep tests were performed at 760°C and 35MPa, and the effects of different aging conditions on creep rate were investigated. Specimens aged for 240 h exhibited the highest creep rate by a factor of 5, with the homogenized sample having the second highest rate. Samples aged for 2.4 h and 24 h exhibited similar low secondary creep rates. Creep tests conducted at 700oC exhibited a significantly lower creep rate compared to those at 760oC. Microstructural analysis was performed on crept samples to explore high temperature straining properties. The quantity and size of Fe2Nb Laves phase and NiAl particles increased in the matrix and on grain boundaries with longer aging time. High temperature tensile tests were performed and compared to room temperature results. The high temperature results were significantly lower when compared to room temperature values. Higher creep rates were correlated with lower yield strengths.

29 CFR 1926.403 - General requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ready and safe operation and maintenance of such equipment. (i) Working clearances. Except as required... sufficient durability to withstand the environment involved. (h) Identification of disconnecting means and... sufficient durability to withstand the environment involved. (i) 600 Volts, nominal, or less. This paragraph...

The influence of matrix composition and reinforcement type on the properties of polysialate composites

NASA Astrophysics Data System (ADS)

Hammell, James A.

There is a critical need for the development of materials for eliminating fire as a cause of death in aircraft accidents. Currently available composites that use organic matrices not only deteriorate at temperatures above 300°C but also emit toxic fumes. The results presented in this dissertation focus on the development of an inorganic matrix that does not burn or emit toxic fumes. The matrix, known as polysialate, can withstand temperatures in excess of 1000°C. The matrix behaves like a ceramic, but does not need high curing temperatures, so it can be processed like many common organic matrices. The major parameters evaluated in this dissertation are: (i) Influence of reinforcement type, (ii) Matrix formulation for both wet-dry durability and high temperature resistance, (iii) Influence of processing variables such as moisture reduction and storage, (iv) Tensile strain capacity of modified matrices and matrices reinforced with ceramic microfibers and discrete carbon fibers, and (v) analytical modeling of mechanical properties. For the reinforcement type; carbon, glass, and stainless steel wire fabrics were investigated. Carbon fabrics with 1, 3, 12, and 50k tows were used. A matrix chemical formulation that can withstand wetting and drying was developed. This formulation was tested at high temperatures to ascertain its stability above 400°C. On the topic of processing, shelf life of prepregged fabric layers and efficient moisture removal methods were studied. An analytical model based on layered reinforcement was developed for analyzing flexural specimens. It is shown that the new inorganic matrix can withstand wetting and drying, and also high temperature. The layered reinforcement concept provides accurate prediction of strength and stiffness for composites reinforced with 1k and 3k tows. The prepregged fabric layers can be stored for 14 days at -15°C without losing strength.

Unique Reactivity of Transition Metal Atoms Embedded in Graphene to CO, NO, O₂ and O Adsorption: A First-Principles Investigation.

PubMed

Chu, Minmin; Liu, Xin; Sui, Yanhui; Luo, Jie; Meng, Changgong

2015-10-27

Taking the adsorption of CO, NO, O₂ and O as probes, we investigated the electronic structure of transition metal atoms (TM, TM = Fe, Co, Ni, Cu and Zn) embedded in graphene by first-principles-based calculations. We showed that these TM atoms can be effectively stabilized on monovacancy defects on graphene by forming plausible interactions with the C atoms associated with dangling bonds. These interactions not only give rise to high energy barriers for the diffusion and aggregation of the embedded TM atoms to withstand the interference of reaction environments, but also shift the energy levels of TM-d states and regulate the reactivity of the embedded TM atoms. The adsorption of CO, NO, O₂ and O correlates well with the weight averaged energy level of TM-d states, showing the crucial role of interfacial TM-C interactions on manipulating the reactivity of embedded TM atoms. These findings pave the way for the developments of effective monodispersed atomic TM composites with high stability and desired performance for gas sensing and catalytic applications.

Electromagnetic Pumps for Conductive-Propellant Feed Systems

NASA Technical Reports Server (NTRS)

Markusic, Thomas E.; Polzin, Kurt A.; Dehoyos, Amado

2005-01-01

Prototype electromagnetic pumps for use with lithium and bismuth propellants were constructed and tested. Such pumps may be used to pressurize future electric propulsion liquid metal feed systems, with the primary advantages being the compactness and simplicity versus alternative pressurization technologies. Design details for two different pumps are described: the first was designed to withstand (highly corrosive) lithium propellant, and t he second was designed to tolerate the high temperature required to pump liquid bismuth. Both qualitative and quantitative test results are presented. Open-loop tests demonstrated the capability of each device to electromagnetically pump its design propellant (lithium or bismuth). A second set of tests accurately quantified the pump pressure developed as a function of current. These experiments, which utilized a more easily handled material (gallium), demonstrated continuously-adjustable pump pressure levels ranging from 0-100 Torr for corresponding input current levels of 0-75 A. While the analysis and testing in this study specifically targeted lithium and bismuth propellants, the underlying design principles should be useful in implementing liquid metal pumps in any conductive-propellant feed system.

29 CFR 1926.1436 - Derricks.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and guying must be designed to withstand maximum horizontal and vertical forces encountered when... be designed to withstand maximum horizontal and vertical forces encountered when operating within...”). (D) Applicable terms in section 7-0.2 (“Definitions”). (ii) Load tests for new hoists. The employer...

29 CFR 1926.1436 - Derricks.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and guying must be designed to withstand maximum horizontal and vertical forces encountered when... be designed to withstand maximum horizontal and vertical forces encountered when operating within...”). (D) Applicable terms in section 7-0.2 (“Definitions”). (ii) Load tests for new hoists. The employer...

29 CFR 1926.1436 - Derricks.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and guying must be designed to withstand maximum horizontal and vertical forces encountered when... be designed to withstand maximum horizontal and vertical forces encountered when operating within...”). (D) Applicable terms in section 7-0.2 (“Definitions”). (ii) Load tests for new hoists. The employer...

29 CFR 1926.1436 - Derricks.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and guying must be designed to withstand maximum horizontal and vertical forces encountered when... be designed to withstand maximum horizontal and vertical forces encountered when operating within...”). (D) Applicable terms in section 7-0.2 (“Definitions”). (ii) Load tests for new hoists. The employer...

Design and Construction Guidance for Community Shelters. FEMA 361.

ERIC Educational Resources Information Center

Federal Emergency Management Agency, Washington, DC.

This manual presents guidance to engineers, architects, building officials, and prospective shelter owners concerning the design and construction of community shelters that will provide protection during tornado and hurricane events. The manual covers two types of community shelters: stand-alone shelters designed to withstand high winds and the…

46 CFR 177.900 - Deck rails.

Code of Federal Regulations, 2010 CFR

2010-10-01

... rails must be designed and constructed to withstand a point load of 91 kilograms (200 pounds) applied at... simultaneously. (c) Where space limitations make deck rails impractical for areas designed for crew use only...) high. (4) While engaged in big game angling, the minimum rail height may be reduced to not less than...

46 CFR 177.900 - Deck rails.

Code of Federal Regulations, 2012 CFR

2012-10-01

... rails must be designed and constructed to withstand a point load of 91 kilograms (200 pounds) applied at... simultaneously. (c) Where space limitations make deck rails impractical for areas designed for crew use only...) high. (4) While engaged in big game angling, the minimum rail height may be reduced to not less than...

46 CFR 177.900 - Deck rails.

Code of Federal Regulations, 2014 CFR

2014-10-01

... rails must be designed and constructed to withstand a point load of 91 kilograms (200 pounds) applied at... simultaneously. (c) Where space limitations make deck rails impractical for areas designed for crew use only...) high. (4) While engaged in big game angling, the minimum rail height may be reduced to not less than...

46 CFR 177.900 - Deck rails.

Code of Federal Regulations, 2011 CFR

2011-10-01

... rails must be designed and constructed to withstand a point load of 91 kilograms (200 pounds) applied at... simultaneously. (c) Where space limitations make deck rails impractical for areas designed for crew use only...) high. (4) While engaged in big game angling, the minimum rail height may be reduced to not less than...

46 CFR 177.900 - Deck rails.

Code of Federal Regulations, 2013 CFR

2013-10-01

... rails must be designed and constructed to withstand a point load of 91 kilograms (200 pounds) applied at... simultaneously. (c) Where space limitations make deck rails impractical for areas designed for crew use only...) high. (4) While engaged in big game angling, the minimum rail height may be reduced to not less than...

40 CFR 63.3561 - What definitions apply to this subpart?

Code of Federal Regulations, 2010 CFR

2010-07-01

... pressurized aerosol product is packaged. Aseptic coating means any coating that must withstand high... application with hand-held nonrefillable aerosol containers, touch-up markers, or marking pens is not a... equipment that may be required to meet the data acquisition and availability requirements of this subpart...

CMOS Ultra Low Power Radiation Tolerant (CULPRiT) Microelectronics

NASA Technical Reports Server (NTRS)

Yeh, Penshu; Maki, Gary

2007-01-01

Space Electronics needs Radiation Tolerance or hardness to withstand the harsh space environment: high-energy particles can change the state of the electronics or puncture transistors making them disfunctional. This viewgraph document reviews the use of CMOS Ultra Low Power Radiation Tolerant circuits for NASA's electronic requirements.

Locking Nut with Stress-Distributing Insert

NASA Technical Reports Server (NTRS)

Daniels, Christopher C.

2010-01-01

Reusable holders have been devised for evaluating high-temperature, plasma-resistant re-entry materials, especially fabrics. Typical material samples tested support thermal-protection-system damage repair requiring evaluation prior to re-entry into terrestrial atmosphere. These tests allow evaluation of each material to withstand the most severe predicted re-entry conditions.

14 CFR 25.1435 - Hydraulic systems.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... Pressure vessels containing gas: High pressure (e.g., accumulators) 3.0 4.0 Low pressure (e.g., reservoirs...) Element design. Each element of the hydraulic system must be designed to: (1) Withstand the proof pressure... ultimate pressure without rupture. The proof and ultimate pressures are defined in terms of the design...

Construction Carpentry. Secondary Schools. Curriculum Guide.

ERIC Educational Resources Information Center

Tellei, Patrick U.

This document is intended to help construction carpentry instructors in the State of Truk, Truk, Federated States of Micronesia, to prepare their senior high school students uniformly to design and build residential structures capable of withstanding typhoons. Because of the threat of typhoons, the carpentry curriculum contained in the guide has a…

NREL Investigates Coatings Needed for Concentrating Solar Power | News |

Science.gov Websites

these systems," said Johney Green, associate laboratory director for mechanical and thermal engineering sciences. CSP plants with low-cost thermal storage enable facilities to deliver electricity heat-transfer fluid and thermal energy storage because they can withstand high temperatures and retain

50 CFR 229.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... highest tensile force which an object can withstand before breaking. Bridle means the lines connecting a... individual authorized by NMFS, or a designated contractor, to record information on marine mammal... fastened to the deck, rail, or drum, and all buoys larger than 6 inches (15.24 cm) in diameter, high flyers...

High Voltage Hybrid Electric Propulsion - Multilayered Functional Insulation System (MFIS) NASA-GRC

NASA Technical Reports Server (NTRS)

Lizcano, M.

2017-01-01

High power transmission cables pose a key challenge in future Hybrid Electric Propulsion Aircraft. The challenge arises in developing safe transmission lines that can withstand the unique environment found in aircraft while providing megawatts of power. High voltage AC, variable frequency cables do not currently exist and present particular electrical insulation challenges since electrical arcing and high heating are more prevalent at higher voltages and frequencies. Identifying and developing materials that maintain their dielectric properties at high voltage and frequencies is crucial.

14 CFR 23.365 - Pressurized cabin loads.

Code of Federal Regulations, 2011 CFR

2011-01-01

... landing. (d) The airplane structure must be strong enough to withstand the pressure differential loads... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Flight Loads § 23... structure must be strong enough to withstand the flight loads combined with pressure differential loads from...

KSC-04pd1717

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Space Station Processing Facility, a worker wraps equipment in plastic in preparation for the expected impact of Hurricane Frances on Saturday. The various modules in the SSPF, such as the Japanese Experiment Module, U.S. Node 2 and Multi-Purpose Logistics Modules, are being covered as well. KSC workers also have powered down the Space Shuttle orbiters, closed their payload bay doors and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The SSPF can withstand sustained winds of 110 mph and wind gusts up to 132 mph. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

High temperature, flexible, fiber-preform seal

NASA Technical Reports Server (NTRS)

Steinetz, Bruce M. (Inventor); Strocky, Paul J. (Inventor)

1992-01-01

A seal is mounted in a rectangular groove in a movable structural panel. The seal comprises a fiber preform constructed of multiple layers of fiber having a uniaxial core. Helical fibers are wound over the core. The fibers are of materials capable of withstanding high temperatures and are both left-hand and right-hand wound. An outer layer wrapped over said helical fibers prevents abrasion damage.

Fast Magnetoresistive Random-Access Memory

NASA Technical Reports Server (NTRS)

Wu, Jiin-Chuan; Stadler, Henry L.; Katti, Romney R.

1991-01-01

Magnetoresistive binary digital memories of proposed new type expected to feature high speed, nonvolatility, ability to withstand ionizing radiation, high density, and low power. In memory cell, magnetoresistive effect exploited more efficiently by use of ferromagnetic material to store datum and adjacent magnetoresistive material to sense datum for readout. Because relative change in sensed resistance between "zero" and "one" states greater, shorter sampling and readout access times achievable.

HAN-Based Monopropellant Technology Development

NASA Technical Reports Server (NTRS)

Reed, Brian

2002-01-01

NASA Glenn Research Center is sponsoring efforts to develop technology for high-performance, high-density, low-freezing point, low-hazards monopropellant systems. The program is focused on a family of monopropellant formulations composed of an aqueous solution of hydroxylammonium nitrate (HAN) and a fuel component. HAN-based monopropellants offer significant mass and volume savings to small (less than 100 kg) satellite for orbit raising and on-orbit propulsion applications. The low-hazards characteristics of HAN-based monopropellants make them attractive for applications where ground processing costs are a significant concern. A 1-lbf thruster has been demonstrated to a 20-kg satellite orbit insertion duty cycle, using a formulation compatible with currently available catalysts. To achieve specific impulse levels above those of hydrazine, catalyst materials that can withstand the high-temperature, corrosive combustion environment of HAN-based monopropellants have to be developed. There also needs to be work done to characterize propellant properties, burning behavior, and material compatibility. NASA is coordinating their monopropellant efforts with those of the United States Air Force.

Evaluation of Venturi Oxygen Stripping (trademark) as a Ballast Water Treatment to Prevent Aquatic Invasions and Ship Corrosion

DTIC Science & Technology

2003-01-01

that can withstand low oxygen levels (e.g., resistant cysts of dinoflagellates, Hallegraeff 1998). Marine bacteria, in particular, will have...Chesapeake Bay zooplankton (copepods, barnacle larvae, polychaete larvae, cladocerans, crustacean nauplii, bivalve larvae, and nematodes ) in less than...zooplankton (copepods, barnacle larvae, polychaete larvae, cladocerans, crustacean nauplii, bivalve larvae, and nematodes ) in control and treated

30 CFR 75.1905-1 - Diesel fuel piping systems.

Code of Federal Regulations, 2010 CFR

2010-07-01

... storage facility. (h) The diesel fuel piping system must not be located in a borehole with electric power... Diesel fuel piping systems. (a) Diesel fuel piping systems from the surface must be designed and operated...) Capable of withstanding working pressures and stresses; (2) Capable of withstanding four times the static...

77 FR 29857 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-21

... of cabin pressurization and the inability of the fuselage to withstand fail-safe loads. DATES: This... cabin pressurization and the inability of the fuselage to withstand fail-safe loads. (f) Compliance You... reference of certain publications listed in the AD as of June 25, 2012. ADDRESSES: For service information...

30 CFR 57.4430 - Surface storage facilities.

Code of Federal Regulations, 2013 CFR

2013-07-01

... liquids shall be— (1) Capable of withstanding working pressures and stresses and compatible with the type.... These pressure relief requirements do not apply to tanks used for storage of Class IIIB liquids that are... withstanding working pressures and stresses; (2) Compatible with the type of liquid stored; and (3) Maintained...

30 CFR 57.4430 - Surface storage facilities.

Code of Federal Regulations, 2011 CFR

2011-07-01

... liquids shall be— (1) Capable of withstanding working pressures and stresses and compatible with the type.... These pressure relief requirements do not apply to tanks used for storage of Class IIIB liquids that are... withstanding working pressures and stresses; (2) Compatible with the type of liquid stored; and (3) Maintained...

Hurricane Proof This!

ERIC Educational Resources Information Center

Sterling, Donna R.

2010-01-01

While learning about the types of weather events that occur in the local area, students in grades 4-6 were asked to consider how structures can be built to withstand extreme weather conditions. Teams of students designed, constructed, and tested buildings to withstand hurricanes and designed the tests they would use to evaluate their structures.…

29 CFR 1926.97 - Electrical protective equipment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... glove. (2) Electrical requirements. (i) Equipment shall be capable of withstanding the ac proof-test voltage specified in Table E-1 or the dc proof-test voltage specified in Table E-2. (A) The proof test shall reliably indicate that the equipment can withstand the voltage involved. (B) The test voltage...

Superelastic Few-Layer Carbon Foam Made from Natural Cotton for All-Solid-State Electrochemical Capacitors.

PubMed

Lin, Tianquan; Liu, Fengxin; Xu, Feng; Bi, Hui; Du, Yahui; Tang, Yufeng; Huang, Fuqiang

2015-11-18

Flexible/stretchable devices for energy storage are essential for future wearable and flexible electronics. Electrochemical capacitors (ECs) are an important technology for supplement batteries in the energy storage and harvesting field, but they are limited by relatively low energy density. Herein, we report a superelastic foam consisting of few-layer carbon nanowalls made from natural cotton as a good scaffold to growth conductive polymer polyaniline for stretchable, lightweight, and flexible all-solid-state ECs. As-prepared superelastic bulk tubular carbon foam (surface area ∼950 m(2)/g) can withstand >90% repeated compression cycling and support >45,000 times its own weight but no damage. The flexible device has a high specific capacitance of 510 F g(-1), a specific energy of 25.5 Wh kg(-1) and a power density of 28.5 kW kg(-1) in weight of the total electrode materials and withstands 5,000 charging/discharging cycles.

THRUST BEARING

DOEpatents

Heller, P.R.

1958-09-16

A thrust bearing suitable for use with a rotor or blower that is to rotate about a vertical axis is descrihed. A centrifagal jack is provided so thnt the device may opernte on one hearing at starting and lower speeds, and transfer the load to another bearing at higher speeds. A low viscosity fluid is used to lubricate the higher speed operation bearing, in connection with broad hearing -surfaces, the ability to withstand great loads, and a relatively high friction loss, as contraated to the lower speed operatio;n bearing which will withstand only light thrust loads but is sufficiently frictionfree to avoid bearing seizure during slow speed or startup operation. An axially aligned shaft pin provides the bearing surface for low rotational speeds, but at higher speed, weights operating against spring tension withdraw nthe shaft pin into the bearing proper and the rotor shaft comes in contact with the large bearing surfaces.

Adaptable Holders for Arc-Jet Screening Candidate Thermal Protection System Repair Materials

NASA Technical Reports Server (NTRS)

Riccio, Joe; Milhoan, Jim D.

2010-01-01

Reusable holders have been devised for evaluating high-temperature, plasma-resistant re-entry materials, especially fabrics. Typical material samples tested support thermal-protection-system damage repair requiring evaluation prior to re-entry into terrestrial atmosphere. These tests allow evaluation of each material to withstand the most severe predicted re-entry conditions.

An improved magnetic tape recorder

NASA Technical Reports Server (NTRS)

Uber, P. W.

1968-01-01

Magnetic tape recorder employs a single capstan for simultaneously driving the supply and take-up reels in such a manner that the tape passing between the reels is kept under a predetermined constant tension. This recorder operates with little power and is sufficiently rugged to withstand the severe stresses encountered in high-altitude balloon flight tests.

De novo genome sequencing and comparative genomics of the date palm Phoenix dactylifera)

USDA-ARS?s Scientific Manuscript database

Date Palm has been vital to the Middle East and other arid regions of the world for more than 5000 years. The date palm's ability to withstand extremely harsh conditions, while producing highly nutritious fruit with relatively minimal care, makes it a good candidate for improving arid land agricultu...

How Should We Measure Psychological Resilience in Sport Performers?

ERIC Educational Resources Information Center

Sarkar, Mustafa; Fletcher, David

2013-01-01

Psychological resilience is important in sport because athletes must constantly withstand a wide range of pressures to attain and sustain high performance. To advance psychologists' understanding of this area, there exists an urgent need to develop a sport-specific measure of resilience. The purpose of this article is to review psychometric…

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Dan Kenna and Jim Landy prepare to examine a Reinforced Carbon Carbon panel using flash thermography. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Dan Kenna and Jim Landy prepare to examine a Reinforced Carbon Carbon panel using flash thermography. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (above) finishes installing a Reinforced Carbon Carbon (RCC) panel to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-08

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (above) finishes installing a Reinforced Carbon Carbon (RCC) panel to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Mike Hyatt (above), Saul Ngy (right) and Jerry Belt (below) install a Reinforced Carbon Carbon (RCC) panel to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-08

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Mike Hyatt (above), Saul Ngy (right) and Jerry Belt (below) install a Reinforced Carbon Carbon (RCC) panel to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (above) completes installation of a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt (above) completes installation of a Reinforced Carbon Carbon (RCC) panel onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt looks over a Reinforced Carbon Carbon (RCC) panel that will be attached to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-08

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Mike Hyatt looks over a Reinforced Carbon Carbon (RCC) panel that will be attached to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Mike Hyatt (above) and Saul Ngy (below right) finish installing a Reinforced Carbon Carbon (RCC) panel to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-08

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Mike Hyatt (above) and Saul Ngy (below right) finish installing a Reinforced Carbon Carbon (RCC) panel to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

High gradient rf gun studies of CsBr photocathodes

DOE PAGES

Vecchione, Theodore; Maldonado, Juan R.; Gierman, Stephen; ...

2015-04-03

CsBr photocathodes have 10 times higher quantum efficiency with only 3 times larger intrinsic transverse emittance than copper. They are robust and can withstand 80 MV/m fields without breaking down or emitting dark current. They can operate in 2×10⁻⁹ torr vacuum and survive exposure to air. They are well suited for generating high pulse charge in rf guns without a photocathode transfer system.

EMP Vulnerabilities of Telecommunications Facilities and Their Relevance to EMP Protection Standards

DTIC Science & Technology

1980-06-01

capacitor must be capable of withstanding surges of two and one-half times the rated voltage with a rise time of the surge to half crest voltage of 4...n Executive Summary This report identifies and categorizes the reasons for High Altitude Electromagnetic Pulse (HEMP) vulnerability of terrestrial...for the design, installation and maintenance of telecommunication facilities. 1.1 Background High- altitude EMP (HEMP) vulnerabilities and effects

Effects of High-Temperature Treatment on the Reaction Between Sn-3%Ag-0.5%Cu Solder and Sputtered Ni-V Film on Ferrite Substrate

NASA Astrophysics Data System (ADS)

Shen, Xiaohu; Jin, Hao; Dong, Shurong; Wong, Hei; Zhou, Jian; Guo, Zhaodi; Wang, Demiao

2012-11-01

We have demonstrated a novel sputtering method for lead-free thin metal films on ferrite substrates for surface-mount inductor applications. In a surface-mounting process, the cladding of enameled wire needs to be burnt off at high temperature, which requires the devices to withstand a high-temperature reliability test at 420°C for 10 s. There are no reports that a sputtered film of thickness less than 6 μm can withstand this test. In this work, we used Ag/Ni-7 wt.%V double metal layers for the metallization. The dissolution of Ni-7 wt.%V in Sn-3%Ag-0.5%Cu lead-free solder at various temperatures was studied in detail. Scanning electron microscopy with energy-dispersive x-ray spectroscopy was used to investigate the interfacial reaction between the sputtered films and the solder. The intermetallic compounds are mainly (Cu,Ni)6Sn5 at 250°C; however, (Ni,Cu)3Sn4 becomes the predominant composition at 420°C. In addition, although outdiffusion of V atoms from the Ni-V layer was observed, its effect on the intermetallic compound (IMC) was insignificant. We further confirmed that the proposed metallization is able to pass the aforementioned high-temperature reliability test.

Proceedings of the Particle Beam Research Workshop, Held at US Air Force Academy, Colorado, Springs, CO on 10-11 January 1980

DTIC Science & Technology

1980-05-01

Components 25 2.7.1 Transformers 25 2.7.2 Solid Dielectric 26 2.7.3 Cables and Connectors 27 III. SOURCES 29 3.1 Preface 29 3.2 Electron Sources 30 3.3 High...be developed which can withstand high voltages , high current densities, and pass large energies per pulse with high repetition rates, high reliability...Ceramics - high voltage hold-off 2) Dielectrics - hold-off recovery after breakdown 3) Metals - low erosion rates, higher j and esaturation 4) Degradation

Radioprotection in depressed metabolic states: The physiology of helium-cold hypothermia

NASA Technical Reports Server (NTRS)

Musacchia, X. J.

1973-01-01

The use of hypothermia as a means of radiation protection was studied on a variety of mammals exposed to 80% helium-20% oxygen atmospheres at low ambient temperatures. Results show that the LD for normothermic animals significantly increased compared with hypothermic animals; similar results were obtained for hibernating mammalians. Pre-exposure of animals to cold temperatures increased their ability to withstand radiation levels close to LD sub 50.

Advanced Protected Services: A Concept Paper on Survivable Service-Oriented Systems

DTIC Science & Technology

2010-05-07

resiliency and protection of such systems to a level where they can withstand sustained attacks from well-motivated adversaries. In this paper we...that are designed for the protection of systems that are based on service-oriented architectures. 15. SUBJECT TERMS 16. SECURITY CLASSIFICATION OF...resilient against malicious attacks , and to demonstrate the utility of the developed advanced protection techniques in settings that exhibit various

Analysis and Cost Optimization of a USCG Remote Hybrid Power System

DTIC Science & Technology

2002-06-01

finding a system that can withstand the extreme weather conditions at these two sites is limited. It is recommended that as technology advances the...sites be conducted. 2. Battery Technology There have been significant advances in battery technology during the recent past. As these advancements ...costs associated with advanced technology decrease to more affordable levels to help 98 identify replacement batteries for the VRLA batteries when

Insights into metazoan evolution from alvinella pompejana cDNAs

PubMed Central

2010-01-01

Background Alvinella pompejana is a representative of Annelids, a key phylum for evo-devo studies that is still poorly studied at the sequence level. A. pompejana inhabits deep-sea hydrothermal vents and is currently known as one of the most thermotolerant Eukaryotes in marine environments, withstanding the largest known chemical and thermal ranges (from 5 to 105°C). This tube-dwelling worm forms dense colonies on the surface of hydrothermal chimneys and can withstand long periods of hypo/anoxia and long phases of exposure to hydrogen sulphides. A. pompejana specifically inhabits chimney walls of hydrothermal vents on the East Pacific Rise. To survive, Alvinella has developed numerous adaptations at the physiological and molecular levels, such as an increase in the thermostability of proteins and protein complexes. It represents an outstanding model organism for studying adaptation to harsh physicochemical conditions and for isolating stable macromolecules resistant to high temperatures. Results We have constructed four full length enriched cDNA libraries to investigate the biology and evolution of this intriguing animal. Analysis of more than 75,000 high quality reads led to the identification of 15,858 transcripts and 9,221 putative protein sequences. Our annotation reveals a good coverage of most animal pathways and networks with a prevalence of transcripts involved in oxidative stress resistance, detoxification, anti-bacterial defence, and heat shock protection. Alvinella proteins seem to show a slow evolutionary rate and a higher similarity with proteins from Vertebrates compared to proteins from Arthropods or Nematodes. Their composition shows enrichment in positively charged amino acids that might contribute to their thermostability. The gene content of Alvinella reveals that an important pool of genes previously considered to be specific to Deuterostomes were in fact already present in the last common ancestor of the Bilaterian animals, but have been secondarily lost in model invertebrates. This pool is enriched in glycoproteins that play a key role in intercellular communication, hormonal regulation and immunity. Conclusions Our study starts to unravel the gene content and sequence evolution of a deep-sea annelid, revealing key features in eukaryote adaptation to extreme environmental conditions and highlighting the proximity of Annelids and Vertebrates. PMID:21080938

Design of surface acoustic wave filters for the multiplex transmission system of multilevel inverter circuits

NASA Astrophysics Data System (ADS)

Kubo, Keita; Kanai, Nanae; Kobayashi, Fumiya; Goka, Shigeyoshi; Wada, Keiji; Kakio, Shoji

2017-07-01

We designed surface acoustic wave (SAW) filters for a multiplex transmission system of multilevel inverter circuits, and applied them to a single-phase three-level inverter. To reduce the transmission delay time of the SAW filters, a four-channel SAW filter array was fabricated and its characteristics were measured. The delay time of the SAW filters was <350 ns, and the delay time difference was reduced to ≤184 ns, less than half that previously reported. The SAW filters withstood up to 990 V, which is sufficient for the inverters used in most domestic appliances. A single-phase three-level inverter with the fabricated SAW filters worked with a total delay time shorter than our target delay time of 2.5 µs. The delay time difference of the proposed system was 0.26 µs, which is sufficient for preventing the inverter circuit from short-circuiting. The SAW filters controlled a multilevel inverter system with simple signal wiring and high dielectric withstanding voltages.

Study Program to Determine the Acceleration Environment Capability of the GG159C Gas- Bearing Spinmotor Final Report

NASA Technical Reports Server (NTRS)

Erickson, G. J.

1964-01-01

The goal of this contract was to determine the g environment under which the GC159C Gas-Bearing Spinmotor (GBSM) could reliably operate. This was fulfilled by building and testing of four GBSM's, a test fixture, and a "dummy" gyro. The test program was divided into two phases when a gas bearing improvement was required to withstand JPL shock requirement of 200 g. Phase I determined existing g capabilities and performance of the GC159C GBSM and gimbal-case structure. Phase II increased GBSM capability to meet required JPL g environments. Life tests were run on two GBSM's which were shocked at a high level to obtain bearing contact while rotating at their operating speed of 23,000 rpm. A third (nonoperating) GBSM was exposed to JPL maximum shock levels, and a fourth (nonoperating) GBSM was exposed to random vibration. Both nonoperating GBSM's were then subjected to life testing.

Withstanding Our Status as Outsiders-Within: Professional Counterspaces for African American Women Student Affairs Administrators

ERIC Educational Resources Information Center

West, Nicole M.

2017-01-01

Although engagement in social and academic counterspaces has been studied as a strategy used by African American college students to withstand racially inhospitable campus climates, very little research documents the impact of professional counterspaces on African American women student affairs administrators. The purpose of this basic…

A highly stable minimally processed plant-derived recombinant acetylcholinesterase for nerve agent detection in adverse conditions

PubMed Central

Rosenberg, Yvonne J.; Walker, Jeremy; Jiang, Xiaoming; Donahue, Scott; Robosky, Jason; Sack, Markus; Lees, Jonathan; Urban, Lori

2015-01-01

Although recent innovations in transient plant systems have enabled gram quantities of proteins in 1–2 weeks, very few have been translated into applications due to technical challenges and high downstream processing costs. Here we report high-level production, using a Nicotiana benthamiana/p19 system, of an engineered recombinant human acetylcholinesterase (rAChE) that is highly stable in a minimally processed leaf extract. Lyophylized clarified extracts withstand prolonged storage at 70 °C and, upon reconstitution, can be used in several devices to detect organophosphate (OP) nerve agents and pesticides on surfaces ranging from 0 °C to 50 °C. The recent use of sarin in Syria highlights the urgent need for nerve agent detection and countermeasures necessary for preparedness and emergency responses. Bypassing cumbersome and expensive downstream processes has enabled us to fully exploit the speed, low cost and scalability of transient production systems resulting in the first successful implementation of plant-produced rAChE into a commercial biotechnology product. PMID:26268538

A highly stable minimally processed plant-derived recombinant acetylcholinesterase for nerve agent detection in adverse conditions.

PubMed

Rosenberg, Yvonne J; Walker, Jeremy; Jiang, Xiaoming; Donahue, Scott; Robosky, Jason; Sack, Markus; Lees, Jonathan; Urban, Lori

2015-08-13

Although recent innovations in transient plant systems have enabled gram quantities of proteins in 1-2 weeks, very few have been translated into applications due to technical challenges and high downstream processing costs. Here we report high-level production, using a Nicotiana benthamiana/p19 system, of an engineered recombinant human acetylcholinesterase (rAChE) that is highly stable in a minimally processed leaf extract. Lyophylized clarified extracts withstand prolonged storage at 70 °C and, upon reconstitution, can be used in several devices to detect organophosphate (OP) nerve agents and pesticides on surfaces ranging from 0 °C to 50 °C. The recent use of sarin in Syria highlights the urgent need for nerve agent detection and countermeasures necessary for preparedness and emergency responses. Bypassing cumbersome and expensive downstream processes has enabled us to fully exploit the speed, low cost and scalability of transient production systems resulting in the first successful implementation of plant-produced rAChE into a commercial biotechnology product.

Enabling propulsion materials for high-speed civil transport engines

NASA Technical Reports Server (NTRS)

Stephens, Joseph R.; Herbell, Thomas P.

1992-01-01

NASA Headquarters and LeRC have advocated an Enabling Propulsion Materials Program (EPM) to begin in FY-92. The High Speed Research Phase 1 program which began in FY-90 has focused on the environmental acceptability of a High Speed Civil Transport (HSCT). Studies by industry, including Boeing, McDonnell Douglas, GE Aircraft Engines, and Pratt & Whitney Aircraft, and in-house studies by NASA concluded that NO(x) emissions and airport noise reduction can only be economically achieved by revolutionary advancements in materials technologies. This is especially true of materials for the propulsion system where the combustor is the key to maintaining low emissions, and the exhaust nozzle is the key to reducing airport noise to an acceptable level. Both of these components will rely on high temperature composite materials that can withstand the conditions imposed by commercial aircraft operations. The proposed EPM program will operate in conjunction with the HSR Phase 1 Program and the planned HSR Phase 2 program slated to start in FY-93. Components and subcomponents developed from advanced materials will be evaluated in the HSR Phase 2 Program.

Aerogel-Based Multilayer Insulation with Micrometeoroid Protection

NASA Technical Reports Server (NTRS)

Begag, Redouane; White, Shannon

2013-01-01

Ultra-low-density, highly hydrophobic, fiber-reinforced aerogel material integrated with MLI (aluminized Mylar reflectors and B4A Dacron separators) offers a highly effective insulation package by providing unsurpassed thermal performance and significant robustness, delivering substantial MMOD protection via the addition of a novel, durable, external aerogel layer. The hydrophobic nature of the aerogel is an important property for maintaining thermal performance if the material is exposed to the environment (i.e. rain, snow, etc.) during ground installations. The hybrid aerogel/MLI/MMOD solution affords an attractive alternative because it will perform thermally in the same range as MLI at all vacuum levels (including high vacuum), and offers significant protection from micrometeoroid damage. During this effort, the required low-density and resilient aerogel materials have been developed that are needed to optimize the thermal performance for space (high vacuum) cryotank applications. The proposed insulation/MMOD package is composed of two sections: a stack of interleaved aerogel layers and MLI intended for cryotank thermal insulation, and a 1.5- to 1-in. (.2.5- to 3.8- cm) thick aerogel layer (on top of the insulation portion) for MMOD protection. Learning that low-density aerogel cannot withstand the hypervelocity impact test conditions, the innovators decided during the course of the program to fabricate a high-density and strong material based on a cross-linked aerogel (X-aerogel; developed elsewhere by the innovators) for MMOD protection. This system has shown a very high compressive strength that is capable of withstanding high-impact tests if a proper configuration of the MMOD aerogel layer is used. It was learned that by stacking two X-aerogel layers [1.5-in. (.3.8-cm) thick] separated by an air gap, the system would be able to hold the threat at a speed of 5 km/s and gpass h the test. The first aerogel panel stopped the projectile from damaging the second aerogel panel. The impacted X-aerogel (the back specimen from the successful test) was further tested in comparison to another similar sample (not impacted) at Kennedy Space Center for thermal conductivity evaluation at cryogenic conditions. The specimens were tested under high vacuum and cryogenic temperatures, using Cryostat 500. The results show that the specimen did not lose a significant amount of thermal performance due to the impact test, especially at high vacuum.

Enabling Technologies for Ceramic Hot Section Components

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

Venkat Vedula; Tania Bhatia

Silicon-based ceramics are attractive materials for use in gas turbine engine hot sections due to their high temperature mechanical and physical properties as well as lower density than metals. The advantages of utilizing ceramic hot section components include weight reduction, and improved efficiency as well as enhanced power output and lower emissions as a result of reducing or eliminating cooling. Potential gas turbine ceramic components for industrial, commercial and/or military high temperature turbine applications include combustor liners, vanes, rotors, and shrouds. These components require materials that can withstand high temperatures and pressures for long duration under steam-rich environments. For Navymore » applications, ceramic hot section components have the potential to increase the operation range. The amount of weight reduced by utilizing a lighter gas turbine can be used to increase fuel storage capacity while a more efficient gas turbine consumes less fuel. Both improvements enable a longer operation range for Navy ships and aircraft. Ceramic hot section components will also be beneficial to the Navy's Growth Joint Strike Fighter (JSF) and VAATE (Versatile Affordable Advanced Turbine Engines) initiatives in terms of reduced weight, cooling air savings, and capability/cost index (CCI). For DOE applications, ceramic hot section components provide an avenue to achieve low emissions while improving efficiency. Combustors made of ceramic material can withstand higher wall temperatures and require less cooling air. Ability of the ceramics to withstand high temperatures enables novel combustor designs that have reduced NO{sub x}, smoke and CO levels. In the turbine section, ceramic vanes and blades do not require sophisticated cooling schemes currently used for metal components. The saved cooling air could be used to further improve efficiency and power output. The objectives of this contract were to develop technologies critical for ceramic hot section components for gas turbine engines. Significant technical progress has been made towards maturation of the EBC and CMC technologies for incorporation into gas turbine engine hot-section. Promising EBC candidates for longer life and/or higher temperature applications relative to current state of the art BSAS-based EBCs have been identified. These next generation coating systems have been scaled-up from coupons to components and are currently being field tested in Solar Centaur 50S engine. CMC combustor liners were designed, fabricated and tested in a FT8 sector rig to demonstrate the benefits of a high temperature material system. Pretest predictions made through the use of perfectly stirred reactor models showed a 2-3x benefit in CO emissions for CMC versus metallic liners. The sector-rig test validated the pretest predictions with >2x benefit in CO at the same NOx levels at various load conditions. The CMC liners also survived several trip shut downs thereby validating the CMC design methodology. Significant technical progress has been made towards incorporation of ceramic matrix composites (CMC) and environmental barrier coatings (EBC) technologies into gas turbine engine hot-section. The second phase of the program focused on the demonstration of a reverse flow annular CMC combustor. This has included overcoming the challenges of design and fabrication of CMCs into 'complex' shapes; developing processing to apply EBCs to 'engine hardware'; testing of an advanced combustor enabled by CMCs in a PW206 rig; and the validation of performance benefits against a metal baseline. The rig test validated many of the pretest predictions with a 40-50% reduction in pattern factor compared to the baseline and reductions in NOx levels at maximum power conditions. The next steps are to develop an understanding of the life limiting mechanisms in EBC and CMC materials, developing a design system for EBC coated CMCs and durability testing in an engine environment.« less

Use of AIRS, OMI, MLS, and TES Data in Assessing Forest Ecosystem Exposure to Ozone

NASA Technical Reports Server (NTRS)

Spruce, Joseph P.

2007-01-01

Ground-level ozone at high levels poses health threats to exposed flora and fauna, including negative impacts to human health. While concern is common regarding depletion of ozone in the stratosphere, portions of the urban and rural United States periodically have high ambient levels of tropospheric ozone on the ground. Ozone pollution can cause a variety of impacts to susceptible vegetation (e.g., Ponderosa and Jeffrey pine species in the southwestern United States), such as stunted growth, alteration of growth form, needle or leaf chlorosis, and impaired ability to withstand drought-induced water stress. In addition, Southern Californian forests with high ozone exposures have been recently subject to multiyear droughts that have led to extensive forest overstory mortality from insect outbreaks and increased incidence of wildfires. Residual forests in these impacted areas may be more vulnerable to high ozone exposures and to other forest threats than ever before. NASA sensors collect a wealth of atmospheric data that have been used recently for mapping and monitoring regional tropospheric ozone levels. AIRS (Atmospheric Infrared Sounder), OMI (Ozone Monitoring Instrument), MLS (Microwave Limb Sounder), and TES (Tropospheric Emission Spectrometer) data could be used to assess forest ecosystem exposure to ozone. Such NASA data hold promise for providing better or at least complementary synoptic information on ground-level ozone levels that Federal agency partners can use to assess forest health trends and to mitigate the threats as needed in compliance with Federal laws and mandates. NASA data products on ozone concentrations may be able to aid applications of DSTs (decision support tools) adopted by the USDA FS (U.S. Department of Agriculture Forest Service) and by the NPS (National Park Service), such as the Ozone Calculator, in which ground ozone estimates are employed to assess ozone impacts to forested vegetation.

Intraspecific variation among Tetranychid mites for ability to detoxify and to induce plant defenses

PubMed Central

Ozawa, Rika; Endo, Hiroki; Iijima, Mei; Sugimoto, Koichi; Takabayashi, Junji; Gotoh, Tetsuo; Arimura, Gen-ichiro

2017-01-01

Two genotypes coexist among Kanzawa spider mites, one of which causes red scars and the other of which causes white scars on leaves, and they elicit different defense responses in host plants. Based on RNA-Seq analysis, we revealed here that the expression levels of genes involved in the detoxification system were higher in Red strains than White strains. The corresponding enzyme activities as well as performances for acaricide resistance and host adaptation toward Laminaceae were also higher in Red strains than White strains, indicating that Red strains were superior in trait(s) of the detox system. In subsequent generations of strains that had survived exposure to fenpyroximate, both strains showed similar resistance to this acaricide, as well as similar detoxification activities. The endogenous levels of salicylic acid and jasmonic acid were increased similarly in bean leaves damaged by original Red strains and their subsequent generations that inherited high detox activity. Jasmonic acid levels were increased in leaves damaged by original White strains, but not by their subsequent generations that inherited high detox activity. Together, these data suggest the existence of intraspecific variation - at least within White strains - with respect to their capacity to withstand acaricides and host plant defenses. PMID:28240222

Methods of Measurement of High Air Velocities by the Hot-wire Method

NASA Technical Reports Server (NTRS)

Weske, John R.

1943-01-01

Investigations of strengths of hot wires at high velocities were conducted with platinum, nickel, and tungsten at approximately 200 Degrees Celcius hot-wire temperature. The results appear to disqualify platinum for velocities approaching the sonic range; whereas nickel withstands sound velocity, and tungsten may be used for supersonic velocities under standard atmospheric conditions. Hot wires must be supported by rigid prolongs at high velocities to avoid wire breakage. Resting current measurements for constant temperature show agreement with King's relation.

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

Espinosa-Loza, Francisco; Ross, Timothy O.; Switzer, Vernon A.

An insert for a cryogenic capable pressure vessel for storage of hydrogen or other cryogenic gases at high pressure. The insert provides the interface between a tank and internal and external components of the tank system. The insert can be used with tanks with any or all combinations of cryogenic, high pressure, and highly diffusive fluids. The insert can be threaded into the neck of a tank with an inner liner. The threads withstand the majority of the stress when the fluid inside the tank that is under pressure.

A new lead-acid battery for high pulse power applications

NASA Technical Reports Server (NTRS)

Rowlette, J. J.; Attia, A. I.

1987-01-01

The development of new electronically conductive materials which can withstand the environment of the positive plates has made possible the construction of a high pulse power sealed bipolar lead-acid battery. The new battery is described and its advantages over other electrochemical systems are outlined. Performance projections show that the peak specific power of the battery can be as high as 90 kW/kg, and that a specific power of 5 kW/kg can be sustained over several thousand pulses.

Heat shock protein 70 in the rat nasal cavity: localisation and response to hyperthermia.

PubMed

Simpson, Sharon A; Alexander, David J; Reed, Celia J

2004-06-01

Heat shock proteins (HSPs) are a group of proteins that are rapidly induced in response to physiological stress, including hyperthermia and exposure to toxicants. Thus they may provide a useful index of toxicity in in vitro systems for screening for toxicity. We have recently developed a rat nasal explant system for investigating upper respiratory tract toxicity, and the aims of this study were to localise HSP70 within the rat nasal cavity and to characterise its response to hyperthermia. Constitutively, HSP70 was found to be predominantly localised to the sustentacular cells, basal cells and Bowman's glands of the olfactory epithelium (OE), with the most intense immunohistochemical staining at levels 3 and 4 of the posterior of the rat nasal cavity. Ethmoturbinates (ETs) and liver slices were exposed to heat shock (37 degrees and 43 degrees C, respectively) for 45 min and then returned to normal culture temperatures (31 degrees and 37 degrees C, respectively) for 24 h. In ETs, HSP72 was maximally induced 4-fold at 4 h after heat shock, and levels then returned to those of control tissue. ATP concentrations were markedly decreased up to 4 h after heat shock and then returned to control levels. In contrast, HSP72 levels in liver slices increased and ATP levels decreased steadily throughout the 24 h culture period. ETs were also able to withstand a 45-min heat shock at 43 degrees C, that is 12 degrees C above normal culture temperature. Incubation of ETs with cycloheximide prior to heat shock reduced the ability of the OE to recover from heat shock at 37 degrees C. Thus the OE of the rat nasal cavity expresses HSP72, and this protein appears to play an important role in the ability of the tissue to withstand hyperthermia.

Development of Fluidic Guidance for KEW (Kinetic Energy Weapon) Projectiles

DTIC Science & Technology

1988-12-30

commanded to a hit-to-kill on a hostile ICBK booster. A novel application of-the photo-acoustic effect is used for laser detection. An acoustic wave...Hughes High Endo-Atmospheric Interceptor Concept.. 2 3 Conceptual SDI KE projectile ........................ 3 4 Schematic of photo-acoustic effect ...practical, KEWs must be lightweight, able to withstand high "g" forces, and insensitive to nuclear and electro-magnetic effects . Laser command guidance can

Applying high-emittance and solar-absorptance coating to aluminum

NASA Technical Reports Server (NTRS)

Progar, D. J.

1973-01-01

Coated surface withstands space environment with negilgible change in radiation characteristics and physical properties. Process can be used with any porous substance, as long as pores are large enough to allow molecules of reacting solutions to enter and yet not so large as to allow nickel sulfide to be leached out of pores before sealing.

Copper-silver-titanium filler metal for direct brazing of structural ceramics

DOEpatents

Moorhead, Arthur J.

1987-01-01

A method of joining ceramics and metals to themselves and to one another is described using a brazing filler metal consisting essentially of 35 to 50 atomic percent copper, 15 to 50 atomic percent silver and 10 to 45 atomic percent titanium. This method produces strong joints that can withstand high service temperatures and oxidizing environments.

Development and Performance Evaluation of Optical Sensors for High Temperature Engine Applications

NASA Technical Reports Server (NTRS)

Adamovsky, G.; Varga, D.; Floyd, B.

2011-01-01

This paper discusses fiber optic sensors designed and constructed to withstand extreme temperatures of aircraft engine. The paper describes development and performance evaluation of fiber optic Bragg grating based sensors. It also describes the design and presents test results of packaged sensors subjected to temperatures up to 1000 C for prolonged periods of time.

Three-dimensional tracking solar energy concentrator and method for making same

NASA Technical Reports Server (NTRS)

Miller, C. G.; Pohl, J. G. (Inventor)

1977-01-01

A three dimensional tracking solar energy concentrator, consisting of a stretched aluminized polymeric membrane supported by a hoop, was presented. The system is sturdy enough to withstand expected windage forces and precipitation. It can provide the high temperature output needed by central station power plants for power production in the multi-megawatt range.

Industrial Tape

NASA Technical Reports Server (NTRS)

1986-01-01

Scotch Brand Tape 364 was developed for NASA by 3M Company to protect electrical instrumentation coils and fluid lines from rocket launch blast conditions. It is an aluminized glass cloth tape which can withstand very high temperatures, is easily applied to compound surfaces, has excellent solar energy reflectance, and does not present an electrostatic hazard. It has potential automotive, transportation, and building construction applications.

Mineral resource of the month: kyanite

USGS Publications Warehouse

Potter, Michael J.

2007-01-01

Kyanite and related minerals are used in making refractories, which are materials that can withstand high-temperature environments, generally in excess of 1,100 degrees Celsius. Refractories form an inner lining to furnaces, kilns and other containers with which molten metals and glass come into contact. Fifty to 70 percent of global refractory consumption is related to the steel industry.

Fiber optic sensor and method for making

DOEpatents

Vartuli, James Scott; Bousman, Kenneth Sherwood; Deng, Kung-Li; McEvoy, Kevin Paul; Xia, Hua

2010-05-18

A fiber optic sensor including a fiber having a modified surface integral with the fiber wherein the modified surface includes an open pore network with optical agents dispersed within the open pores of the open pore network. Methods for preparing the fiber optic sensor are also provided. The fiber optic sensors can withstand high temperatures and harsh environments.

49 CFR 195.205 - Repair, alteration and reconstruction of aboveground breakout tanks that have been in service.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., examination, and material requirements of those respective standards. (3) For high pressure tanks built to API... service must be capable of withstanding the internal pressure produced by the hazardous liquid to be... approximately atmospheric pressure constructed of carbon and low alloy steel, welded or riveted, and non...

49 CFR 173.467 - Tests for demonstrating the ability of Type B and fissile materials packagings to withstand...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 2 2014-10-01 2014-10-01 false Tests for demonstrating the ability of Type B and fissile materials packagings to withstand accident conditions in transportation. 173.467 Section 173.467 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION...

49 CFR 173.467 - Tests for demonstrating the ability of Type B and fissile materials packagings to withstand...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Tests for demonstrating the ability of Type B and fissile materials packagings to withstand accident conditions in transportation. 173.467 Section 173.467 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION...

46 CFR 162.028-3 - Requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... which are subjected to pressure, exclusive of the hose, shall be at least five times the maximum working... which will withstand a minimum bursting pressure of 6,000 p.s.i., and a discharge hose or tube which will withstand a minimum bursting pressure of 5,000 p.s.i. The hose shall be constructed with either a...

46 CFR 162.028-3 - Requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... which are subjected to pressure, exclusive of the hose, shall be at least five times the maximum working... which will withstand a minimum bursting pressure of 6,000 p.s.i., and a discharge hose or tube which will withstand a minimum bursting pressure of 5,000 p.s.i. The hose shall be constructed with either a...

46 CFR 162.028-3 - Requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... which are subjected to pressure, exclusive of the hose, shall be at least five times the maximum working... which will withstand a minimum bursting pressure of 6,000 p.s.i., and a discharge hose or tube which will withstand a minimum bursting pressure of 5,000 p.s.i. The hose shall be constructed with either a...

21 CFR 801.410 - Use of impact-resistant lenses in eyeglasses and sunglasses.

Code of Federal Regulations, 2010 CFR

2010-04-01

... potential eye injury, eyeglasses and sunglasses must be fitted with impact-resistant lenses, except in those... shall be capable of withstanding the impact test described in paragraph (d)(2) of this section. (3) Each... resistance and shall be capable of withstanding the impact test described in paragraph (d)(2) of this section...

21 CFR 801.410 - Use of impact-resistant lenses in eyeglasses and sunglasses.

Code of Federal Regulations, 2011 CFR

2011-04-01

... potential eye injury, eyeglasses and sunglasses must be fitted with impact-resistant lenses, except in those... shall be capable of withstanding the impact test described in paragraph (d)(2) of this section. (3) Each... resistance and shall be capable of withstanding the impact test described in paragraph (d)(2) of this section...

21 CFR 801.410 - Use of impact-resistant lenses in eyeglasses and sunglasses.

Code of Federal Regulations, 2013 CFR

2013-04-01

... potential eye injury, eyeglasses and sunglasses must be fitted with impact-resistant lenses, except in those... shall be capable of withstanding the impact test described in paragraph (d)(2) of this section. (3) Each... resistance and shall be capable of withstanding the impact test described in paragraph (d)(2) of this section...

21 CFR 801.410 - Use of impact-resistant lenses in eyeglasses and sunglasses.

Code of Federal Regulations, 2014 CFR

2014-04-01

... potential eye injury, eyeglasses and sunglasses must be fitted with impact-resistant lenses, except in those... shall be capable of withstanding the impact test described in paragraph (d)(2) of this section. (3) Each... resistance and shall be capable of withstanding the impact test described in paragraph (d)(2) of this section...

21 CFR 801.410 - Use of impact-resistant lenses in eyeglasses and sunglasses.

Code of Federal Regulations, 2012 CFR

2012-04-01

... potential eye injury, eyeglasses and sunglasses must be fitted with impact-resistant lenses, except in those... shall be capable of withstanding the impact test described in paragraph (d)(2) of this section. (3) Each... resistance and shall be capable of withstanding the impact test described in paragraph (d)(2) of this section...

Time-Dependent Temperature Measurements in Post-Detonation Combustion: Current State-of-the-Art Methods and Emerging Technologies

DTIC Science & Technology

2016-03-01

17 6. SENSOR PARTICLES...explosion also limit measurement options since any sensors employed must be able to withstand the extreme environment, or at least transmit the...in detonations and fireballs. On the other hand, temperature measurements have been less extensive, partly because sensors rugged enough to withstand

KSC-04pd1697

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, workers prepare to close the payload bay doors on Atlantis in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1692

NASA Image and Video Library

2004-08-31

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility prepare to stow the landing gear on the orbiter Atlantis in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters, and closing their payload bay doors. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1694

NASA Image and Video Library

2004-08-31

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility prepare the wheel bay to stow Atlantis’ landing gear in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters, and closing their payload bay doors. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1711

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility finish Hurricane preparations on the payload bay doors of Atlantis. Preparing for the expected impact of Hurricane Frances on Saturday, workers also powered down the Space Shuttle orbiters, and stowed the landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1691

NASA Image and Video Library

2004-08-31

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility prepare to close the nose wheel doors on Atlantis in preparation for the expected impact of Hurricane Frances on Saturday. Preparations at KSC include powering down the Space Shuttle orbiters, closing their payload bay doors and stowing their landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1688

NASA Image and Video Library

2004-08-31

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility prepare the orbiter Atlantis and related equipment for the expected impact of Hurricane Frances on Saturday. Preparations at KSC include powering down the Space Shuttle orbiters, closing their payload bay doors and stowing their landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1703

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the payload bay doors on Atlantis are being closed in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1710

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility cover up areas of Atlantis with plastic, preparing for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters, closing the payload bay doors and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1693

NASA Image and Video Library

2004-08-31

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility prepare to stow the landing gear on the orbiter Atlantis in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters, and closing their payload bay doors. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1699

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Atlantis’ payload bay doors are being closed in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1698

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, workers prepare to close the payload bay doors on Atlantis in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1690

NASA Image and Video Library

2004-08-31

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility prepare to close the nose wheel doors on Atlantis in preparation for the expected impact of Hurricane Frances on Saturday. Preparations at KSC include powering down the Space Shuttle orbiters, closing their payload bay doors and stowing their landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1689

NASA Image and Video Library

2004-08-31

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility prepare to close the nose wheel doors on Atlantis in preparation for the expected impact of Hurricane Frances on Saturday. Preparations at KSC include powering down the Space Shuttle orbiters, closing their payload bay doors and stowing their landing gear. They are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1708

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility cover up areas of Atlantis, preparing for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters, closing the payload bay doors and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1702

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the payload bay doors on Atlantis are being closed in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1700

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the payload bay doors on Atlantis are being closed in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1696

NASA Image and Video Library

2004-08-31

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Atlantis’ wheels are raised into their wheel bays in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters, and closing their payload bay doors. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1704

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, the payload bay doors on Atlantis are being closed in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1701

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, a worker checks out part of Atlantis after payload bay doors were closed in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1695

NASA Image and Video Library

2004-08-31

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Atlantis’ wheels are raised into their wheel bays in preparation for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters, and closing their payload bay doors. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

KSC-04pd1709

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility cover up areas of Atlantis with plastic, preparing for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters, closing the payload bay doors and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

Yeast Tolerance to Various Stresses Relies on the Trehalose-6P Synthase (Tps1) Protein, Not on Trehalose*

PubMed Central

Petitjean, Marjorie; Teste, Marie-Ange; François, Jean M.; Parrou, Jean-Luc

2015-01-01

Trehalose is a stable disaccharide commonly found in nature, from bacteria to fungi and plants. For the model yeast Saccharomyces cerevisiae, claims that trehalose is a stress protectant were based indirectly either on correlation between accumulation of trehalose and high resistance to various stresses or on stress hypersensitivity of mutants deleted for TPS1, which encodes the first enzyme in trehalose biosynthetic pathway. Our goal was to investigate more directly which one, between trehalose and/or the Tps1 protein, may serve yeast cells to withstand exposure to stress. By employing an original strategy that combined the use of mutant strains expressing catalytically inactive variants of Tps1, with MAL+ yeast strains able to accumulate trehalose from an exogenous supply, we bring for the first time unbiased proof that trehalose does not protect yeast cells from dying and that the stress-protecting role of trehalose in this eukaryotic model was largely overestimated. Conversely, we identified the Tps1 protein as a key player for yeast survival in response to temperature, oxidative, and desiccation stress. We also showed by robust RT-quantitative PCR and genetic interaction analysis that the role of Tps1 in thermotolerance is not dependent upon Hsf1-dependent transcription activity. Finally, our results revealed that the Tps1 protein is essential to maintain ATP levels during heat shock. Altogether, these findings supported the idea that Tps1 is endowed with a regulatory function in energy homeostasis, which is essential to withstand adverse conditions and maintain cellular integrity. PMID:25934390

Exploring the Genetic Signature of Body Size in Yucatan Miniature Pig

PubMed Central

Kim, Hyeongmin; Song, Ki Duk; Kim, Hyeon Jeong; Park, WonCheoul; Kim, Jaemin; Lee, Taeheon; Shin, Dong-Hyun; Kwak, Woori; Kwon, Young-jun; Sung, Samsun; Moon, Sunjin; Lee, Kyung-Tai; Kim, Namshin; Hong, Joon Ki; Eo, Kyung Yeon; Seo, Kang Seok; Kim, Girak; Park, Sungmoo; Yun, Cheol-Heui; Kim, Hyunil; Choi, Kimyung; Kim, Jiho; Lee, Woon Kyu; Kim, Duk-Kyung; Oh, Jae-Don; Kim, Eui-Soo; Cho, Seoae; Lee, Hak-Kyo; Kim, Tae-Hun; Kim, Heebal

2015-01-01

Since being domesticated about 10,000–12,000 years ago, domestic pigs (Sus scrofa domesticus) have been selected for traits of economic importance, in particular large body size. However, Yucatan miniature pigs have been selected for small body size to withstand high temperature environment and for laboratory use. This renders the Yucatan miniature pig a valuable model for understanding the evolution of body size. We investigate the genetic signature for selection of body size in the Yucatan miniature pig. Phylogenetic distance of Yucatan miniature pig was compared to other large swine breeds (Yorkshire, Landrace, Duroc and wild boar). By estimating the XP-EHH statistic using re-sequencing data derived from 70 pigs, we were able to unravel the signatures of selection of body size. We found that both selections at the level of organism, and at the cellular level have occurred. Selection at the higher levels include feed intake, regulation of body weight and increase in mass while selection at the molecular level includes cell cycle and cell proliferation. Positively selected genes probed by XP-EHH may provide insight into the docile character and innate immunity as well as body size of Yucatan miniature pig. PMID:25885114

Heavy Metal Pollution from Gold Mines: Environmental Effects and Bacterial Strategies for Resistance.

PubMed

Fashola, Muibat Omotola; Ngole-Jeme, Veronica Mpode; Babalola, Olubukola Oluranti

2016-10-26

Mining activities can lead to the generation of large quantities of heavy metal laden wastes which are released in an uncontrolled manner, causing widespread contamination of the ecosystem. Though some heavy metals classified as essential are important for normal life physiological processes, higher concentrations above stipulated levels have deleterious effects on human health and biota. Bacteria able to withstand high concentrations of these heavy metals are found in the environment as a result of various inherent biochemical, physiological, and/or genetic mechanisms. These mechanisms can serve as potential tools for bioremediation of heavy metal polluted sites. This review focuses on the effects of heavy metal wastes generated from gold mining activities on the environment and the various mechanisms used by bacteria to counteract the effect of these heavy metals in their immediate environment.

Heavy Metal Pollution from Gold Mines: Environmental Effects and Bacterial Strategies for Resistance

PubMed Central

Fashola, Muibat Omotola; Ngole-Jeme, Veronica Mpode; Babalola, Olubukola Oluranti

2016-01-01

Mining activities can lead to the generation of large quantities of heavy metal laden wastes which are released in an uncontrolled manner, causing widespread contamination of the ecosystem. Though some heavy metals classified as essential are important for normal life physiological processes, higher concentrations above stipulated levels have deleterious effects on human health and biota. Bacteria able to withstand high concentrations of these heavy metals are found in the environment as a result of various inherent biochemical, physiological, and/or genetic mechanisms. These mechanisms can serve as potential tools for bioremediation of heavy metal polluted sites. This review focuses on the effects of heavy metal wastes generated from gold mining activities on the environment and the various mechanisms used by bacteria to counteract the effect of these heavy metals in their immediate environment. PMID:27792205

Comparison of protection in rainbow trout (Salmo gairdneri) inoculated with and fed Hagerman redmouth bacterins

USGS Publications Warehouse

Anderson, D.P.; Nelson, J.R.

1974-01-01

Rainbow trout (Salmo gairdneri) fed 1.0 mg Hagerman redmouth bacterin per fish for 2 wk had no detectable specific, circulating, agglutinating antibody. In fish given a single subcutaneous inoculation of 1.0 mg of bacterin per fish, antibody was present from 3 wk later until 3 mo later, when the final sample was taken. Median lethal doses at various intervals after the bacterins were administered indicated that the inoculated fish could withstand a greater challenge by subcutaneous inoculation of the virulent bacteria than the orally immunized fish. The fish fed the vaccine lost their protection within 6 wk, whereas the inoculated fish had high levels of protection through 3 mo. The degree of protection was also confirmed by a "natural" exposure challenge.

Sedum-dominated green-roofs in a semi-arid region increase CO2 concentrations during the dry season.

PubMed

Agra, Har'el; Klein, Tamir; Vasl, Amiel; Shalom, Hadar; Kadas, Gyongyver; Blaustein, Leon

2017-04-15

Green roofs are expected to absorb and store carbon in plants and soils and thereby reduce the high CO 2 concentration levels in big cities. Sedum species, which are succulent perennials, are commonly used in extensive green roofs due to their shallow root system and ability to withstand long water deficiencies. Here we examined CO 2 fixation and emission rates for Mediterranean Sedum sediforme on green-roof experimental plots. During late winter to early spring, we monitored CO 2 concentrations inside transparent tents placed over 1m 2 plots and followed gas exchange at the leaf level using a portable gas-exchange system. We found high rates of CO 2 emission at daytime, which is when CO 2 concentration in the city is the highest. Both plot- and leaf-scale measurements showed that these CO 2 emissions were not fully compensated by the nighttime uptake. We conclude that although carbon sequestration may only be a secondary benefit of green roofs, for improving this ecosystem service, other plant species than Sedum should also be considered for use in green roofs, especially in Mediterranean and other semi-arid climates. Copyright © 2017 Elsevier B.V. All rights reserved.

High refractive index and temperature sensitivity LPGs for high temperature operation

NASA Astrophysics Data System (ADS)

Nascimento, I. M.; Gouveia, C.; Jana, Surnimal; Bera, Susanta; Baptista, J. M.; Moreira, Paulo; Biwas, Palas; Bandyopadhyay, Somnath; Jorge, Pedro A. S.

2013-11-01

A fiber optic sensor for high sensitivity refractive index and temperature measurement able to withstand temperature up to 450 °C is reported. Two identical LPG gratings were fabricated, whereas one was coated with a high refractive index (~1.78) sol-gel thin film in order to increase its sensitivity to the external refractive index. The two sensors were characterized and compared in refractive index and temperature. Sensitivities of 1063 nm/RIU (1.338 - 1.348) and 260 pm/°C were achieved for refractive index and temperature, respectively.

Radiation-Hardened Circuitry Using Mask-Programmable Analog Arrays. Final Report

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

Britton, Jr., Charles L.; Ericson, Milton Nance; Bobrek, Miljko

As the recent accident at Fukushima Daiichi so vividly demonstrated, telerobotic technologies capable of withstanding high radiation environments need to be readily available to enable operations, repair, and recovery under severe accident scenarios where human entry is extremely dangerous or not possible. Telerobotic technologies that enable remote operation in high dose rate environments have undergone revolutionary improvement over the past few decades. However, much of this technology cannot be employed in nuclear power environments due the radiation sensitivity of the electronics and the organic insulator materials currently in use. This is the final report of the activities involving the NEETmore » 2 project Radiation Hardened Circuitry Using Mask-Programmable Analog Arrays. We present a detailed functional block diagram of the proposed data acquisition system, the thought process leading to technical decisions, the implemented system, and the tested results from the systems. This system will be capable of monitoring at least three parameters of importance to nuclear reactor monitoring: temperature, radiation level, and pressure.« less

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

Maloy, Stuart Andrew; Pestovich, Kimberly Shay; Anderoglu, Osman

The Fuel Cycle Research and Development program is investigating methods of transmuting minor actinides in various fuel cycle options. To achieve this goal, new fuels and cladding materials must be developed and tested to high burnup levels (e.g. >20%) requiring cladding to withstand very high doses (greater than 200 dpa) while in contact with the coolant and the fuel. To develop and qualify materials to a total fluence greater than 200 dpa requires development of advanced alloys and irradiations in fast reactors to test these alloys. Recent results from testing numerous ferritic/martensitic steels at low temperatures suggest that improvements inmore » low temperature radiation tolerance can be achieved through carefully controlling the nitrogen content in these alloys. Thus, four new heats of HT-9 were produced with controlled nitrogen content: two by Metalwerks and two by Sophisticated Alloys. Initial results on these new alloys are presented including microstructural analysis and hardness testing. Future testing will include irradiation testing with ions and in reactor.« less

Cellulase applied to the leaves of sweet pepper (Capsicum annuum L. var. grossum) upregulates the production of salicylic and azelaic acids.

PubMed

Sato, Chizuru; Oka, Norikuni; Nabeta, Kensuke; Matsuura, Hideyuki

2011-01-01

Treating the leaves of sweet pepper (Capsicum annuum L. var. grossum) with an aqueous solution of cellulase resulted in a four-fold increase in the salicylic acid level compared to a control plant. The level of endogenous azelaic acid was also elevated by the cellulase treatment. Azelaic acid has recently been reported to act as a mobile "priming" agent to arm plants against pathogenic attack. Our results are consistent with this and that the cellulase treatment enhanced the ability of sweet pepper to withstand viral attack.

KSC-04pd1707

NASA Image and Video Library

2004-09-01

KENNEDY SPACE CENTER, FLA. - Workers in the Orbiter Processing Facility unwrap plastic for use in covering equipment as part of preparations for the expected impact of Hurricane Frances on Saturday. Other preparations at KSC include powering down the Space Shuttle orbiters, closing the payload bay doors and stowing the landing gear. Workers are also taking precautions against flooding by moving spacecraft hardware off the ground and sandbagging facilities. The Orbiter Processing Facility is constructed of concrete and steel and was designed to withstand winds of 105 mph. The Vehicle Assembly Building is constructed of concrete and steel and was designed to withstand winds of 125 mph. Other payload and flight hardware support facilities can endure winds of 110 mph. Launch pads and the Payload Hazardous Servicing Facility can withstand 125-mph winds.

[Research on partial least squares for determination of impurities in the presence of high concentration of matrix by ICP-AES].

PubMed

Wang, Yan-peng; Gong, Qi; Yu, Sheng-rong; Liu, You-yan

2012-04-01

A method for detecting trace impurities in high concentration matrix by ICP-AES based on partial least squares (PLS) was established. The research showed that PLS could effectively correct the interference caused by high level of matrix concentration error and could withstand higher concentrations of matrix than multicomponent spectral fitting (MSF). When the mass ratios of matrix to impurities were from 1 000 : 1 to 20 000 : 1, the recoveries of standard addition were between 95% and 105% by PLS. For the system in which interference effect has nonlinear correlation with the matrix concentrations, the prediction accuracy of normal PLS method was poor, but it can be improved greatly by using LIN-PPLS, which was based on matrix transformation of sample concentration. The contents of Co, Pb and Ga in stream sediment (GBW07312) were detected by MSF, PLS and LIN-PPLS respectively. The results showed that the prediction accuracy of LIN-PPLS was better than PLS, and the prediction accuracy of PLS was better than MSF.

Lightening Soldiers' Loads by Lifting PV Cells onto Flexible Surfaces |

Science.gov Websites

efficiency of cells grown on thick-glass substrates. Reese's challenge has been to combine the best of both CdTe solar cells on flexible glass. "When you grow a CdTe cell, you need to grow it for highest glass, which can withstand high temperatures, was promising, this approach had a drawback. Even flexible

Survivability of Mycobacterium avium subsp paratuberculosis in grass silage after fermentation and exposure to low pH and high organic acids

USDA-ARS?s Scientific Manuscript database

Mycobacterium avium subsp paratuberculosis (Map) is a pathogen of concern in dairy production due to its ability to withstand harsh conditions and cause new infections. Infection is a result of ingesting Map cells from contaminated feed, water, or manure. The goal of this research was to evaluate th...

Coatings Preserve Metal, Stone, Tile, and Concrete

NASA Technical Reports Server (NTRS)

2014-01-01

John B. Schutt, a chemist at Goddard Space Flight Center, created a coating for spacecraft that could resist corrosion and withstand high heat. After retiring from NASA, Schutt used his expertise to create new formulations for Daytona Beach, Florida-based Adsil Corporation, which now manufactures a family of coatings to preserve various surfaces. Adsil has created 150 jobs due to the products.

Research on Nitride Thin Films, Advanced Plasma Diagnostics, and Charged-Particle Processes

DTIC Science & Technology

2006-07-01

Additionally, these components are being placed closer to the point of use--requiring that they operate in extreme temperature environments ...reasons for component failure. To operate in extreme temperature environments , electronic and electrical components must withstand higher ambient...hybrid and plug-in hybrid-powered automobiles, heart defibrillators , and industrial equipment will benefit from a new generation of capacitors. High

KENNEDY SPACE CENTER, FLA. - Billy Witt, a midbody shop mechanic with United Space Alliance, checks a part used for installation of a Reinforced Carbon Carbon (RCC) panel to the leading edge of the wing of an orbiter. Above him is an RCC panel just installed on Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-08

KENNEDY SPACE CENTER, FLA. - Billy Witt, a midbody shop mechanic with United Space Alliance, checks a part used for installation of a Reinforced Carbon Carbon (RCC) panel to the leading edge of the wing of an orbiter. Above him is an RCC panel just installed on Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers share the task of examining a Reinforced Carbon Carbon panel using flash thermography. From left are Paul Ogletree, Jim Landy (kneeling), Dan Phillips and Dan Kenna. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers share the task of examining a Reinforced Carbon Carbon panel using flash thermography. From left are Paul Ogletree, Jim Landy (kneeling), Dan Phillips and Dan Kenna. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Jim Landy, NDE specialist with United Space Alliance (USA), watches a monitor off-screen to examine a Reinforced Carbon Carbon panel using flash thermography. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Jim Landy, NDE specialist with United Space Alliance (USA), watches a monitor off-screen to examine a Reinforced Carbon Carbon panel using flash thermography. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers share the task of examining a Reinforced Carbon Carbon panel using flash thermography. From left are Dan Kenna, Jim Landy, Paul Ogletree and Dan Phillips. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers share the task of examining a Reinforced Carbon Carbon panel using flash thermography. From left are Dan Kenna, Jim Landy, Paul Ogletree and Dan Phillips. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Dan Kenna (right) positions a Reinforced Carbon Carbon panel on the table to perform flash thermography. In the background, Paul Ogletree observes the monitor. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance worker Dan Kenna (right) positions a Reinforced Carbon Carbon panel on the table to perform flash thermography. In the background, Paul Ogletree observes the monitor. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Mike Hyatt (left) Saul Ngy (center) and Jerry Belt (right) lift a Reinforced Carbon Carbon (RCC) panel to attach onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Mike Hyatt (left) Saul Ngy (center) and Jerry Belt (right) lift a Reinforced Carbon Carbon (RCC) panel to attach onto the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Mike Hyatt (left), Saul Ngy (center) and Jerry Belt (right) prepare to install a Reinforced Carbon Carbon (RCC) panel to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-08

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Mike Hyatt (left), Saul Ngy (center) and Jerry Belt (right) prepare to install a Reinforced Carbon Carbon (RCC) panel to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Mike Hyatt (left) Jerry Belt (center), and Saul Ngy (right), lift a Reinforced Carbon Carbon (RCC) panel they will attach to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Mike Hyatt (left) Jerry Belt (center), and Saul Ngy (right), lift a Reinforced Carbon Carbon (RCC) panel they will attach to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Jerry Belt, with United Space Alliance, checks a spar attachment on the wing of the orbiter Atlantis before installing Reinforced Carbon Carbon (RCC) panels on the wing. The spars - floating joints - reduce loading on the panels caused by wing deflections. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Jerry Belt, with United Space Alliance, checks a spar attachment on the wing of the orbiter Atlantis before installing Reinforced Carbon Carbon (RCC) panels on the wing. The spars - floating joints - reduce loading on the panels caused by wing deflections. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Jim Landy (front), Dan Phillips and Dan Kenna watch a monitor showing results of flash thermography on the Reinforced Carbon Carbon panel on the table (foreground). Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers Jim Landy (front), Dan Phillips and Dan Kenna watch a monitor showing results of flash thermography on the Reinforced Carbon Carbon panel on the table (foreground). Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers, from center, left to right, Saul Ngy, Jerry Belt and Mike Hyatt, prepare to attach a Reinforced Carbon Carbon (RCC) panel (on the table) to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers, from center, left to right, Saul Ngy, Jerry Belt and Mike Hyatt, prepare to attach a Reinforced Carbon Carbon (RCC) panel (on the table) to the leading edge of the wing of the orbiter Atlantis. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

High temperature thermo-physical properties of SPS-ed W-Cu functional gradient materials

NASA Astrophysics Data System (ADS)

Galatanu, Magdalena; Enculescu, Monica; Galatanu, Andrei

2018-02-01

The divertor of a fusion reactor like DEMO requires materials able to withstand high heat fluxes and neutron irradiation for several years. For the water cooling concept of this essential part of the reactor, the most likely plasma facing material will be W, while the heatsink material considered is CuCrZr or an improved version of such a Cu-based alloy. To realize W-Cu alloy joints able to withstand thousands of thermal cycles can be difficult due to the difference between the thermal expansion coefficients of these materials. In this work we investigate the possibility to realize such joints by using W-Cu functional gradient materials (FGMs) produced from nanometric and micrometric metallic powders mixtures and consolidated by spark plasma sintering at about 900 °C. Morphological and thermal properties investigations, performed for typical compositions, shows that the best results are obtained using powders with micrometric dimensions. A resulting 1 mm thick, 3 layers W-Cu FGM produced by this simple method shows a remarkable almost constant thermal conductivity value of 200 W m-1 K-1, from room temperature up to 1000 °C.

Air-assisted liquid-liquid microextraction integrated with QuEChERS for determining endocrine-disrupting compounds in fish by high-performance liquid chromatography-tandem mass spectrometry.

PubMed

Luo, Zhoufei; Lu, Jing; Li, Haipu; Tu, Yi; Wan, Yuehao; Yang, Zhaoguang

2018-09-15

A new, sensitive, and rapid method based on the Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) approach and air-assisted liquid-liquid microextraction (AALLME) technology was developed for the determination of 20 endocrine-disrupting compounds (EDCs) in fish by high-performance liquid chromatography-tandem mass spectrometry. The method first integrates AALLME into QuEChERS to achieve clean-up and enrichment of the EDCs in one step. A self-made glass tube was enfolded with plasticine to withstand the high centrifugal force. The established method was developed by optimization of the parameters. High linearities (R 2  > 0.9924) and recoveries (78.2-118.6%) at three spiked levels (5, 10, and 20 ng g -1 ), and low relative standard deviation values (1.1-14.5%) and limits of detection (0.03-0.80 ng g -1 ) were obtained. The method comparison shows that the proposed method is superior as it involves less organic solvent usage, simple operation and high efficiency. This method was successfully applied to different fishes for analyzing EDCs. Copyright © 2018 Elsevier Ltd. All rights reserved.

Qualification of Electrical Ground Support Equipment for New Space Programs

NASA Technical Reports Server (NTRS)

SotoToro, Felix A.; Vu, Bruce T.; Hamilton, Mark S.

2011-01-01

With the Space Shuttle program coming to an end, the National Aeronautics and Space Administration (NASA) is moving to a new space flight program that will allow expeditions beyond low earth orbit. The space vehicles required to comply with these missions will be carrying heavy payloads. This implies that the Earth departure stage capabilities must be of higher magnitudes, given the current propulsion technology. The engineering design of the new flight hardware comes with some structural, thermal, propulsion and other subsystems' challenges. Meanwhile, the necessary ground support equipment (GSE) used to test, validate, verify and process the flight hardware must withstand the new program specifications. This paper intends to provide the qualification considerations during implementation of new electrical GSE for space programs. A team of engineers was formed to embark on this task, and facilitate the logistics process and ensure that the electrical, mechanical and fluids subsystems conduct the proper level of testing. Ultimately, each subsystem must certify that each piece of ground support equipment used in the field is capable of withstanding the strenuous vibration, acoustics, environmental, thermal and Electromagnetic Interference (EMf) levels experienced during pre-launch, launch and post-launch activities. The benefits of capturing and sharing these findings will provide technical, cost savings and schedule impacts infon11ation to both the technical and management community. Keywords: Qualification; Testing; Ground Support Equipment; Electromagnetic Interference Testing; Vibration Testing; Acoustic Testing; Power Spectral Density.

Fiberoptic characteristics for extreme operating environments

NASA Technical Reports Server (NTRS)

Delcher, R. C.

1992-01-01

Fiberoptics could offer several major benefits for cryogenic liquid-fueled rocket engines, including lightning immunity, weight reduction, and the possibility of implementing a number of new measurements for engine condition monitoring. The technical feasibility of using fiberoptics in the severe environments posed by cryogenic liquid-fueled rocket engines was determined. The issues of importance and subsequent requirements for this use of fiberoptics were compiled. These included temperature ranges, moisture embrittlement succeptability, and the ability to withstand extreme shock and vibration levels. Different types of optical fibers were evaluated and several types of optical fibers' ability to withstand use in cryogenic liquid-fueled rocket engines was demonstrated through environmental testing of samples. This testing included: cold-bend testing, moisture embrittlement testing, temperature cycling, temperature extremes testing, vibration testing, and shock testing. Three of five fiber samples withstood the tests to a level proving feasibility, and two of these remained intact in all six of the tests. A fiberoptic bundle was also tested, and completed testing without breakage. Preliminary cabling and harnessing for fiber protection was also demonstrated. According to cable manufacturers, the successful -300 F cold bend, vibration, and shock tests are the first instance of any major fiberoptic cable testing below roughly -55 F. This program has demonstrated the basic technical feasibility of implementing optical fibers on cryogenic liquid-fueled rocket engines, and a development plan is included highlighting requirements and issues for such an implementation.

Alleviating brain stress: what alternative animal models have revealed about therapeutic targets for hypoxia and anoxia

PubMed Central

Milton, Sarah L; Dawson-Scully, Ken

2014-01-01

While the mammalian brain is highly dependent on oxygen, and can withstand only a few minutes without air, there are both vertebrate and invertebrate examples of anoxia tolerance. One example is the freshwater turtle, which can withstand days without oxygen, thus providing a vertebrate model with which to examine the physiology of anoxia tolerance without the pathology seen in mammalian ischemia/reperfusion studies. Insect models such as Drosophila melanogaster have additional advantages, such as short lifespans, low cost and well-described genetics. These models of anoxia tolerance share two common themes that enable survival without oxygen: entrance into a state of deep hypometabolism, and the suppression of cellular injury during anoxia and upon restoration of oxygen. The study of such models of anoxia tolerance, adapted through millions of years of evolution, may thus suggest protective pathways that could serve as therapeutic targets for diseases characterized by oxygen deprivation and ischemic/reperfusion injuries. PMID:25264428

Pivots - A Bottom-Up Approach to Enhance Resilience

DTIC Science & Technology

2015-12-01

similar to a business incubator) to provide entrepreneurs with tools and resources to withstand disaster. Case studies and best practices identify...Salve Regina University, 2013 Submitted in partial fulfillment of the requirements for the degree of MASTER OF ARTS IN SECURITY STUDIES ...business incubator) to provide entrepreneurs with tools and resources to withstand disaster. Case studies and best practices identify and inform models of

The research progress of large-aperture fused silica for high power laser

NASA Astrophysics Data System (ADS)

Shao, Zhufeng; Wang, Yufen; Xiang, Zaikui; Rao, Chuandong

2016-03-01

Because of its excellent optical performance, the fused silica is widely used in laser industry. In addition, the fused silica can withstand high power laser, due to its pure component, and the performance is most outstanding within all types of glasses. So fused silica can be used for optical lens in high power laser field. From the manufacturing process stand point, the fused silica can be categorized to four types: type Ⅰ, type Ⅱ, type Ⅲ, and type Ⅳ. The fused silica of type Ⅰand type Ⅱ is made through melting silica sand in graphite furnace or oxyhydrogen flame. There are many defects in these types of fused silica, for example, the air bubbles, inclusions and metallic impurity. The other two types are made by synthetic reaction of SiCl4 with water in oxyhydrogen or plasma flame. Both type Ⅲ and Ⅳ have excellent performance in transmittance and internal quality. However, type Ⅳof fused silica has disadvantage in small aperture and overall high manufacturing cost. Take the transmittance and internal quality into consideration, the type Ⅲ fused silica is the most suitable for large-aperture lens, and can withstand high power laser. The systemic studies of manufacturing process were done to improve the performance of type Ⅲ fused silica in various areas, for instance, the optical homogeneity, the stress birefringence, the absorption coefficient and the damage threshold. There are four steps in manufacturing process of type Ⅲ fused silica, ingot production, reshaping, annealing and cold-working. The critical factors of ingot production, like the flame of burner and the structure of furnace, were deeply studied in this paper to improve the performance of fused silica. On the basis of the above research, the performance and quality of the fused silica measured up to advanced world levels. For instance, the result of optical homogeneity can be controlled to 2-5 ppm, the stress birefringence is better than 4 nm/cm, the absorption coefficient is about 5.971ppm cm-1 (1ω), the damage threshold is greater than 80, 25 and 23 J/cm2 with the wavelength at 1064, 532 and 351nm respectively, the bandwidth used for measuring is 3ns.The fused silica has already been used in the area of high power laser facilities, aerospace industry, primary lens of interferometer based on its excellent performance.

High-Resolution Protein Structure Determination by Serial Femtosecond Crystallography

PubMed Central

Boutet, Sébastien; Lomb, Lukas; Williams, Garth J.; Barends, Thomas R. M.; Aquila, Andrew; Doak, R. Bruce; Weierstall, Uwe; DePonte, Daniel P.; Steinbrener, Jan; Shoeman, Robert L.; Messerschmidt, Marc; Barty, Anton; White, Thomas A.; Kassemeyer, Stephan; Kirian, Richard A.; Seibert, M. Marvin; Montanez, Paul A.; Kenney, Chris; Herbst, Ryan; Hart, Philip; Pines, Jack; Haller, Gunther; Gruner, Sol M.; Philipp, Hugh T.; Tate, Mark W.; Hromalik, Marianne; Koerner, Lucas J.; van Bakel, Niels; Morse, John; Ghonsalves, Wilfred; Arnlund, David; Bogan, Michael J.; Caleman, Carl; Fromme, Raimund; Hampton, Christina Y.; Hunter, Mark S.; Johansson, Linda C.; Katona, Gergely; Kupitz, Christopher; Liang, Mengning; Martin, Andrew V.; Nass, Karol; Redecke, Lars; Stellato, Francesco; Timneanu, Nicusor; Wang, Dingjie; Zatsepin, Nadia A.; Schafer, Donald; Defever, James; Neutze, Richard; Fromme, Petra; Spence, John C. H.; Chapman, Henry N.; Schlichting, Ilme

2013-01-01

Structure determination of proteins and other macromolecules has historically required the growth of high-quality crystals sufficiently large to diffract x-rays efficiently while withstanding radiation damage. We applied serial femtosecond crystallography (SFX) using an x-ray free-electron laser (XFEL) to obtain high-resolution structural information from microcrystals (less than 1 micrometer by 1 micrometer by 3 micrometers) of the well-characterized model protein lysozyme. The agreement with synchrotron data demonstrates the immediate relevance of SFX for analyzing the structure of the large group of difficult-to-crystallize molecules. PMID:22653729

Experimental validation of prototype high voltage bushing

NASA Astrophysics Data System (ADS)

Shah, Sejal; Tyagi, H.; Sharma, D.; Parmar, D.; M. N., Vishnudev; Joshi, K.; Patel, K.; Yadav, A.; Patel, R.; Bandyopadhyay, M.; Rotti, C.; Chakraborty, A.

2017-08-01

Prototype High voltage bushing (PHVB) is a scaled down configuration of DNB High Voltage Bushing (HVB) of ITER. It is designed for operation at 50 kV DC to ensure operational performance and thereby confirming the design configuration of DNB HVB. Two concentric insulators viz. Ceramic and Fiber reinforced polymer (FRP) rings are used as double layered vacuum boundary for 50 kV isolation between grounded and high voltage flanges. Stress shields are designed for smooth electric field distribution. During ceramic to Kovar brazing, spilling cannot be controlled which may lead to high localized electrostatic stress. To understand spilling phenomenon and precise stress calculation, quantitative analysis was performed using Scanning Electron Microscopy (SEM) of brazed sample and similar configuration modeled while performing the Finite Element (FE) analysis. FE analysis of PHVB is performed to find out electrical stresses on different areas of PHVB and are maintained similar to DNB HV Bushing. With this configuration, the experiment is performed considering ITER like vacuum and electrical parameters. Initial HV test is performed by temporary vacuum sealing arrangements using gaskets/O-rings at both ends in order to achieve desired vacuum and keep the system maintainable. During validation test, 50 kV voltage withstand is performed for one hour. Voltage withstand test for 60 kV DC (20% higher rated voltage) have also been performed without any breakdown. Successful operation of PHVB confirms the design of DNB HV Bushing. In this paper, configuration of PHVB with experimental validation data is presented.

Electroforming of a throat nozzle for a combustion facility (NASA Langley Reimbursable Program)

NASA Technical Reports Server (NTRS)

Dini, J. W.; Johnson, H. R.

1976-01-01

Special procedures were developed and then utilized for plating nickel over channels of a throat nozzle section of a NASA Langley combustor facility. When tested hydrostatically, the part failed in the stainless-steel substrate and not at the interface between the plating and substrate. The procedures used for plating the part are detailed as are high-temperature property data which show that the part can withstand long-term, high-temperature exposure without suffering degradation of the plated bond.

Adaptable, Deployable Entry and Placement Technology (ADEPT) Overview of FY15 Accomplishments

NASA Technical Reports Server (NTRS)

Wercinski, P.; Brivkalns, C.; Cassell, A.; Chen, Y.-K.; Boghozian, T.; Chinnapongse, R.; Gasch, M.; Kruger, C.; Makino, A.; Milos, F.;

BAKABLE ULTRA-HIGH VACUUM VALVE

DOEpatents

Mark, J.T.; Gantz, I.H.

1962-07-10

S>This patent relates to a valve useful in applications involving successively closing and opening a communication between a chamber evacuated to an ultra-high vacuum condition of the order of 10/sup -10/ millimeters of mercury and another chamber or the ambient. The valve is capable of withstanding extended baking at 450 deg C and repeated opening and closing without repiacement of the valve seat (approximately 200 cycle limit). The seal is formed by mutual interdiffusion weld, coerced by a pneumatic actuator. (AEC)

Fiber-Reinforced Superalloys For Rocket Engines

NASA Technical Reports Server (NTRS)

Lewis, Jack R.; Yuen, Jim L.; Petrasek, Donald W.; Stephens, Joseph R.

1990-01-01

Report discusses experimental studies of fiber-reinforced superalloy (FRS) composite materials for use in turbine blades in rocket engines. Intended to withstand extreme conditions of high temperature, thermal shock, atmospheres containing hydrogen, high cycle fatigue loading, and thermal fatigue, which tax capabilities of even most-advanced current blade material - directionally-solidified, hafnium-modified MAR M-246 {MAR M-246 (Hf) (DS)}. FRS composites attractive combination of properties for use in turbopump blades of advanced rocket engines at temperatures from 870 to 1,100 degrees C.

MOSFET Power Controller

NASA Technical Reports Server (NTRS)

Mitchell, J.; Jones, K.

1986-01-01

High current and voltage controlled remotely. Remote Power Conroller includes two series-connected banks of parallel-connected MOSFET's to withstand high current and voltage. Voltage sharing between switch banks, low-impedance, gate-drive circuits used. Provided controlled range for turn on. Individually trimmable to insure simultaneous switching within few nanoseconds during both turn on and turn off. Control circuit for each switch bank and over-current trip circuit float independently and supplied power via transformer T1 from inverter. Control of floating stages by optocouplers.

MOCVD Process Technology for Affordable, High-Yield, High-Performance MESFET Structures. MIMIC Phase 3

DTIC Science & Technology

1993-01-26

by an optical pyrometer that views the inside of the susceptor through a sapphire light pipe. The gas delivery system is of standard commercial design ...of the operating conditions for MESFET growth. 2.2.2 Modifications to the Apparatus for MIMIC Spire designed and installed a bell jar capable of...withstanding, without water cooling, the 500 to 1 100’C temperatures needed for MOCVD growth. The bell jar features a flow disrupter of proprietary design

Thermodynamic, Transport and Chemical Properties of Reference JP-8

DTIC Science & Technology

2006-06-01

external diameter, 0.18 cm internal diameter) that are sealed on one end with a stainless steel plug welded by a clean tungsten-inert-gas ( TIG ) 15...tubing with an internal diameter of 0.02 cm, also TIG welded to the cell. Each cell and valve is capable of withstanding a pressure in excess of 105... process . Each cell is connected to a high-pressure high-temperature valve at the other end with a short length of 0.16 cm diameter 316 stainless steel

Boundary Layer Transition Flight Experiment Overview and In-Situ Measurements

NASA Technical Reports Server (NTRS)

Berger, Karen T.; Anderson, Brian P.; Campbell, Charles H.; Garske, Michael T.; Saucedo, Luis A.; Kinder, Gerald R.

2010-01-01

In support of the Boundary Layer Transition Flight Experiment (BLT FE) Project, a manufactured protuberance tile was installed on the port wing of Space Shuttle Orbiter Discovery for the flights of STS-119, STS-128 and STS-131. Additional instrumentation was installed in order to obtain more spatially resolved measurements downstream of the protuberance. This paper provides an overview of the BLT FE Project. Significant efforts were made to place the protuberance at an appropriate location on the Orbiter and to design the protuberance to withstand the expected environments. A high-level overview of the in-situ flight data is presented, along with a summary of the comparisons between pre- and post-flight analysis predictions and flight data. Comparisons show that predictions for boundary layer transition onset time closely match the flight data, while predicted temperatures were significantly higher than observed flight temperatures.

Aerocoat 7 Replacement Coatings

NASA Technical Reports Server (NTRS)

2008-01-01

Kennedy Space Center has used Aerocoat 7 (AR-7) to protect stainless-steel flex hoses at Launch Complex (LC-39) and hydraulic lines of the Mobile Launcher Platform (MLP) because it provides excellent corrosion protection in low-temperature applications. The Sovereign Company produced AR-7 exclusively for NASA but discontinued production because the coating released high levels of volatile organic compounds (VOCs) and had a significant environmental impact. The purpose of this project was to select and evaluate potential replacement coatings for AR-7 that would be more environmentally sound. The physical and mechanical properties of commercially available coatings were investigated through the Internet. The ideal coating would be fluid enough to penetrate the outer mesh of a stainless-steel flex hose and coat the inner hose, and flexible enough to withstand the movement of the hose, as well as the expansion and contraction of its metal caused by changes in temperature.

The FE-I4 Pixel Readout Chip and the IBL Module

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

Barbero, Marlon; Arutinov, David; Backhaus, Malte

2012-05-01

FE-I4 is the new ATLAS pixel readout chip for the upgraded ATLAS pixel detector. Designed in a CMOS 130 nm feature size process, the IC is able to withstand higher radiation levels compared to the present generation of ATLAS pixel Front-End FE-I3, and can also cope with higher hit rate. It is thus suitable for intermediate radii pixel detector layers in the High Luminosity LHC environment, but also for the inserted layer at 3.3 cm known as the 'Insertable B-Layer' project (IBL), at a shorter timescale. In this paper, an introduction to the FE-I4 will be given, focusing on testmore » results from the first full size FE-I4A prototype which has been available since fall 2010. The IBL project will be introduced, with particular emphasis on the FE-I4-based module concept.« less

BLT Flight Experiment Overview and In-Situ Measurements

NASA Technical Reports Server (NTRS)

Anderson, Brian P.; Campbell, Charles H.; Saucedo, Luis A.; Kinder, Gerald R.

2010-01-01

In support of the Boundary Layer Transition Flight Experiment (BLT FE) Project, a manufactured protuberance tile was installed on the port wing of Space Shuttle Orbiter Discovery for the flight of STS-119. Additional instrumentation was also installed in order to obtain more spatially resolved measurements. This paper will provide an overview of the BLT FE Project, including the project history, organizations involved, and motivations for the flight experiment. Significant efforts were made to place the protuberance at an appropriate location on the Orbiter and to design the protuberance to withstand the expected environments. Efforts were also extended to understand the as-fabricated shape of the protuberance and the thermal protection system tile configuration surrounding the protuberance. A high level overview of the in-situ flight data will be presented, along with a summary of the comparisons between pre- and post-flight analysis predictions and flight data.

Comparison of Several Selective Media for Isolation and Differentiation of Coagulase-Positive Strains of Staphylococcus aureus1

PubMed Central

McDivitt, Maxine E.; Topp, Eleanor B.

1964-01-01

Six coagulase-positive strains of Staphylococcus aureus which had been cultivated in Brain Heart Infusion broth, milk, and brine were plated on seven isolation media. A significant difference in the growth patterns of the individual strains was found as well as a significant effect resulting from the previous cultivation history before plating. Brine and, to a lesser extent, milk were found to reduce maximal cell concentrations attained, but strains grown in brine and milk showed greater ability to withstand the selective action of the isolation media. Fibrinogen applied to the surface of five of the media allowed the formation of characteristic halos by coagulase-positive strains of S. aureus. Only half of the strains studied produced a zone of precipitation on SM110-Egg Yolk agar. The isolation medium containing cycloheximide and a high level of polymxin B was most inhibitory to the organisms. PMID:14131367

Factors associated with the use of violence among urban black adolescents.

PubMed

DuRant, R H; Cadenhead, C; Pendergrast, R A; Slavens, G; Linder, C W

1994-04-01

The purpose of this study was to examine social and psychological factors associated with the use and nonuse of violence among Black adolescents living in a community with a high level of violent crime. Adolescents (n = 225, 44% male) 11 to 19 years of age living in or around nine housing projects in an urban area were administered an anonymous questionnaire. Self-reported use of violence was associated with exposure to violence and personal victimization, hopelessness, depression, family conflict, previous corporal punishment, purpose in life, self-assessment of the probability of being alive at age 25, and age and was higher among males. These data support the hypothesis that exposure to violence is associated with adolescents' self-reported use of violence. However, adolescents with a higher sense of purpose in life and less depression were better able to withstand the influence of exposure to violence in the home and in the community.

Overview of the Acoustic Testing of the European Service Module Structural Test Article (E-STA)

NASA Technical Reports Server (NTRS)

Hughes, William; Fogt, Vince; Le Plenier, Cyprien; Duval, Francois; Durand, Jean-Francois; Staab, Lucas D.; Hozman, Aron; Mcnelis, Anne; Bittinger, Samantha; Thirkettle, Anthony;

Overview of the Acoustic Testing of the European Service Module Structural Test Article (E-STA)

NASA Technical Reports Server (NTRS)

Hughes, William; Le Plenier, Cyprien; Duval, Francois; Staab, Lucas; Hozman, Aron; Thirkettle, Anthony; Fogt, Vincent; Durand, Jean-Francois; McNelis, Anne; Bittinger, Samantha;

Diamond Microchannel Heat Sink Designs For High Heat Flux Thermal Control

NASA Astrophysics Data System (ADS)

Corbin, Michael V.; DeBenedictis, Matthew M.; James, David B.; LeBlanc, Stephen P.; Paradis, Leo R.

2002-08-01

Directed energy weapons, wide band gap semiconductor based radars, and other powerful systems present significant thermal control challenges to component designers. heat Flux levels approaching 2000 W/cm(2) are encountered at the base of laser diodes, and levels as high as 500 WI /cm(2) are expected in laser slabs and power amplifier tube collectors. These impressive heat flux levels frequently combine with strict operating temperature requirements to further compound the thermal control problem. Many investigators have suggested the use of diamond heat spreaders to reduce flux levels at or near to its source, and some have suggested that diamond microchannel heat sinks ultimately may play a significant role in the solution of these problems. Design engineers at Raytheon Company have investigated the application of all-diamond microchannel heat sinks to representative high heat flux problems and have found the approach promising. Diamond microchannel fabrication feasibility has been demonstrated; integration into packaging systems and the accompanying material compatibility issues have been addressed; and thermal and hydrodynamic performance predictions have been made for selected, possible applications. An example of a practical, all diamond microchannel heat sink has been fabricated, and another is in process and will be performance tested. The heat sink assembly is made entirely of optical quality, CVD diamond and is of sufficient strength to withstand the thermal and pressure-induced mechanical loads associated with manufacture and use in tactical weapons environment. The work presented describes the development program's accomplishments to date, and highlights many of the areas for future study.

DS-2 Mars Microprobe Battery

NASA Technical Reports Server (NTRS)

Frank, H.; Kindler, A.; Deligiannis, F.; Davies, E.; Blankevoort, J.; Ratnakumar, B. V.; Surampudi, S.

1999-01-01

In January of 1999 the NM DS-2 Mars microprobe will be launched to impact on Mars in December. The technical objectives of the missions are to demonstrate: key technologies, a passive atmospheric entry, highly integrated microelectronics which can withstand both low temperatures and high decelerations, and the capability to conduct in-situ, surface and subsurface science data acquisition. The scientific objectives are to determine if ice is present below the Martian surface, measure the local atmospheric pressure, characterize the thermal properties of the martian subsurface soil, and to estimate the vertical temperature gradient of the Martian soil. The battery requirements are 2-4 cell batteries, with voltage of 6-14 volts, capacity of 550 mAh at 80C, and 2Ah at 25C, shelf life of 2.5 years, an operating temperature of 60C and below, and the ability to withstand shock impact of 80,000 g's. The technical challenges and the approach is reviewed. The Li-SOCL2 system is reviewed, and graphs showing the current and voltage is displayed, along with the voltage over discharge time. The problems encountered during the testing were: (1) impact sensitivity, (2) cracking of the seals, and (3) delay in voltage. A new design resulted in no problems in the impact testing phase. The corrective actions for the seal problems involved: (1) pre weld fill tube, (2) an improved heat sink during case to cover weld and (3) change the seal dimensions to reduce stress. To correct the voltage delay problem the solutions involved: (1) drying the electrodes to reduce contamination by water, (2) assemblage of the cells within a week of electrode manufacture, (3) ensure electrolyte purity, and (4) provide second depassivation pulse after landing. The conclusions on further testing were that the battery can: (1) withstand anticipated shock of up to 80,000 g, (2) meet the discharge profile post shock at Mars temperatures, (3) meet the required self discharge rate and (4) meet environmental requirements.

Moisture properties

Treesearch

Roger M. Rowell

2005-01-01

Wood was designed by nature over millions of years to perform in a wet environment. The wood structure is formed in a water-saturated environment in the living tree, and the water in the living tree keeps the wood elastic and able to withstand environmental strain such as high wind loads. We cut down a tree, dry the wood, and mainly use it in its dry state. But wood in...

Quantification of the Sensitivity of Mycobacterium avium subsp paratuberculosis and Salmonella enterica subsp enterica to Low pH and High Organic Acids using Propidium Monoazide and Quantitative PCR

USDA-ARS?s Scientific Manuscript database

Mycobacterium avium subsp paratuberculosis (Map) and Salmonella enterica subsp enterica (S. enterica) are two pathogens that are a concern to food and animal safety due to their ability to withstand harsh conditions encountered in the natural environment and within the host during pathogenesis. Acid...

Improved Fiber-Optic-Coupled Pressure And Vibration Sensors

NASA Technical Reports Server (NTRS)

Zuckerwar, Allan J.; Cuomo, Frank W.

1994-01-01

Improved fiber-optic coupler enables use of single optical fiber to carry light to and from sensor head. Eliminates problem of alignment of multiple fibers in sensor head and simplifies calibration by making performance both more predictable and more stable. Sensitivities increased, sizes reduced. Provides increased margin for design of compact sensor heads not required to contain amplifier circuits and withstand high operating temperatures.

Target seedling strategies for intensively managed plantations in the Oregon Coast Range

Treesearch

Mark Wall

2011-01-01

The target Douglas-fir seedling for outplanting on Roseburg Resources Company timberlands is a least-cost, large [stem] caliper 1- to 2-year old bareroot (>8 mm) or container (>6 mm) seedling with good form, high root growth potential, and the ability to withstand browse without the use of browse deterrents. This target is achieved through the use of large cell...

Copper-silver-titanium-tin filler metal for direct brazing of structural ceramics

DOEpatents

Moorhead, Arthur J.

1988-04-05

A method of joining ceramics and metals to themselves and to one another at about 800.degree. C. is described using a brazing filler metal consisting essentially of 35 to 50 at. % copper, 40 to 50 at. % silver, 1 to 15 at. % titanium, and 2 to 8 at. % tin. This method produces strong joints that can withstand high service temperatures and oxidizing environments.

Yeast Tolerance to Various Stresses Relies on the Trehalose-6P Synthase (Tps1) Protein, Not on Trehalose.

PubMed

Petitjean, Marjorie; Teste, Marie-Ange; François, Jean M; Parrou, Jean-Luc

2015-06-26

Trehalose is a stable disaccharide commonly found in nature, from bacteria to fungi and plants. For the model yeast Saccharomyces cerevisiae, claims that trehalose is a stress protectant were based indirectly either on correlation between accumulation of trehalose and high resistance to various stresses or on stress hypersensitivity of mutants deleted for TPS1, which encodes the first enzyme in trehalose biosynthetic pathway. Our goal was to investigate more directly which one, between trehalose and/or the Tps1 protein, may serve yeast cells to withstand exposure to stress. By employing an original strategy that combined the use of mutant strains expressing catalytically inactive variants of Tps1, with MAL(+) yeast strains able to accumulate trehalose from an exogenous supply, we bring for the first time unbiased proof that trehalose does not protect yeast cells from dying and that the stress-protecting role of trehalose in this eukaryotic model was largely overestimated. Conversely, we identified the Tps1 protein as a key player for yeast survival in response to temperature, oxidative, and desiccation stress. We also showed by robust RT-quantitative PCR and genetic interaction analysis that the role of Tps1 in thermotolerance is not dependent upon Hsf1-dependent transcription activity. Finally, our results revealed that the Tps1 protein is essential to maintain ATP levels during heat shock. Altogether, these findings supported the idea that Tps1 is endowed with a regulatory function in energy homeostasis, which is essential to withstand adverse conditions and maintain cellular integrity. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Effect of high CO{sub 2} on cold acclimation and deacclimation of three conifers

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

Tinus, R.W.; Greer, D.H.; Robinson, L.A.

1995-12-31

Atmospheric CO{sub 2} levels are rising, and whether or not this leads to a climate change, high CO{sub 2} is known to have some direct effects of plants. One aspect that has only begun to be explored is possible effects on cold hardiness. Well adapted woody plants can tolerate the lowest temperatures to which they may be exposed at all times of the year. Every year temperate and boral woody plants must cold harden in a timely manner in autumn, become hardy enough to withstand the coldest winter temperatures, and not lose their hardiness prematurely in the spring. The authorsmore » objective was to determine the effect of elevated CO{sub 2} on cold acclimation and deacclimation of three commercially important conifers. Seedlings of three conifers were cold hardened and dehardened in growth rooms under 350 or 700 ppm CO{sub 2}. High CO{sub 2} had little effect on cold hardiness of radiata pine, but increased autumn and spring hardiness of Douglas-fir. High CO{sub 2} increased hardiness of ponderosa pine in autumn and decreased it in the spring.« less

Novel Synthesis and Characterization of Inorganic Fullerene Type WS2 and Graphene Hybrids

DTIC Science & Technology

2013-03-01

Figure 1.   Photograph of two sailors wearing a “light” version of body armor (Image used with permission from LT Melanie Chambers and LT Kathryn...protection body armor in use is a vast improvement over the animal hides and chain mail our descendants wore many years ago [1]. Today’s body armor...worn, but lowers the level of threats the body armor will be able to withstand. Often such operating environments force soldiers to choose between

Pleiotropic roles of the matricellular protein Sparc in tendon maturation and ageing

PubMed Central

Gehwolf, Renate; Wagner, Andrea; Lehner, Christine; Bradshaw, Amy D.; Scharler, Cornelia; Niestrawska, Justyna A.; Holzapfel, Gerhard A.; Bauer, Hans-Christian; Tempfer, Herbert; Traweger, Andreas

2016-01-01

Acute and chronic tendinopathies remain clinically challenging and tendons are predisposed to degeneration or injury with age. Despite the high prevalence of tendon disease in the elderly, our current understanding of the mechanisms underlying the age-dependent deterioration of tendon function remains very limited. Here, we show that Secreted protein acidic and rich in cysteine (Sparc) expression significantly decreases in healthy-aged mouse Achilles tendons. Loss of Sparc results in tendon collagen fibrillogenesis defects and Sparc−/− tendons are less able to withstand force in comparison with their respective wild type counterparts. On the cellular level, Sparc-null and healthy-aged tendon-derived cells exhibited a more contracted phenotype and an altered actin cytoskeleton. Additionally, an elevated expression of the adipogenic marker genes PPARγ and Cebpα with a concomitant increase in lipid deposits in aged and Sparc−/− tendons was observed. In summary, we propose that Sparc levels in tendons are critical for proper collagen fibril maturation and its age-related decrease, together with a change in ECM properties favors lipid accretion in tendons. PMID:27586416

Water-use efficiency and relative growth rate mediate competitive interactions in Sonoran Desert winter annual plants.

PubMed

Gremer, Jennifer R; Kimball, Sarah; Keck, Katie R; Huxman, Travis E; Angert, Amy L; Venable, D Lawrence

2013-10-01

A functional approach to investigating competitive interactions can provide a mechanistic understanding of processes driving population dynamics, community assembly, and the maintenance of biodiversity. In Sonoran Desert annual plants, a trade-off between relative growth rate (RGR) and water-use efficiency (WUE) contributes to species differences in population dynamics that promote long-term coexistence. Traits underlying this trade-off explain variation in demographic responses to precipitation as well as life history and phenological patterns. Here, we ask how these traits mediate competitive interactions. • We conducted competition trials for three species occupying different positions along the RGR-WUE trade-off axis and compared the effects of competition at high and low soil moisture. We compared competitive effect (ability to suppress neighbors) and competitive response (ability to withstand competition from neighbors) among species. • The RGR-WUE trade-off predicted shifts in competitive responses at different soil moistures. The high-RGR species was more resistant to competition in high water conditions, while the opposite was true for the high-WUE species. The intermediate RGR species tended to have the strongest impact on all neighbors, so competitive effects did not scale directly with differences in RGR and WUE among competitors. • Our results reveal mechanisms underlying long-term variation in fitness: high-RGR species perform better in years with large, frequent rain events and can better withstand competition under wetter conditions. The opposite is true for high-WUE species. Such resource-dependent responses strongly influence community dynamics and can promote coexistence in variable environments.

Advanced Control Surface Seal Development for Future Space Vehicles

NASA Technical Reports Server (NTRS)

DeMange, Jeffrey J.; Dunlap, Patrick H., Jr.; Steinetz, Bruce M.

2004-01-01

High temperature control surface seals have been identified as a critical technology in the development of future space vehicles. These seals must withstand temperatures of up to 2600 F and protect underlying temperature-sensitive structures (such as actuators and sealing capability by remaining resilient during flight conditions. The current baseline seal, used on the Shuttle orbiters and the X-38 vehicle, consists of a Nextel 312 sheath, an internal Inconel X-750 knitted spring tube, and hand-stuffed Saffil batting. Unfortunately at high temperatures (> 1500 F), the seal resiliency significantly degrades due to yielding and creep of the spring tube element. The permanent set in the seals can result in flow passing over the seals and subsequent damage to temperature sensitive components downstream of the seals. Another shortcoming of the baseline seal is that instances have been reported on Shuttle flights where some of the hand-stuffed Saffil batting insulation has been extracted, thus potentially compromising the seal. In vehicles where the thermal protection systems are delicate (such as with Shuttle tiles), the control surface seals must also limit the amount of force applied to the opposing surfaces. Additionally, in many applications the seals are subjected to scrubbing as control surfaces are actuated. The seals must be able to withstand any damage resulting from this high temperature scrubbing and retain their heat/flow blocking abilities.

Atoms for Peace Initiative for the 21st Century

DTIC Science & Technology

2011-05-01

Daiichi after the Earthquake and Tsunami. Natural disasters lead to nuclear emergency at Japan’s Fukushima Daiichi ” Nuclear News (April 2011), 18...that affected the six Fukushima Daiichi nuclear power plants in northeast Japan on Friday, March 11, 2011 have yet to be fully understood. Some... Fukushima Daiichi was originally designed to withstand a 3-meter tsunami but later the seawall off- shore was increased to withstand a design basis 5.7

Surface modification of epoxy resin using He/CF4 atmospheric pressure plasma jet for flashover withstanding characteristics improvement in vacuum

NASA Astrophysics Data System (ADS)

Chen, Sile; Wang, Shuai; Wang, Yibo; Guo, Baohong; Li, Guoqiang; Chang, Zhengshi; Zhang, Guan-Jun

2017-08-01

For enhancing the surface electric withstanding strength of insulating materials, epoxy resin (EP) samples are treated by atmospheric pressure plasma jet (APPJ) with different time interval from 0 to 300s. Helium (He) and tetrafluoromethane (CF4) mixtures are used as working gases with the concentration of CF4 ranging 0%-5%, and when CF4 is ∼3%, the APPJ exhibits an optimal steady state. The flashover withstanding characteristics of modified EP in vacuum are greatly improved under appropriate APPJ treatment conditions. The surface properties of EP samples are evaluated by surface roughness, scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and water contact angle. It is considered that both physical and chemical effects lead to the enhancement of flashover strength. The physical effect is reflected in the increase of surface roughness, while the chemical effect is reflected in the graft of fluorine groups.

Miniaturized Single-Shot Valve and its Application to the ExoMars Pasteur Payload

NASA Technical Reports Server (NTRS)

Muller, Pierre; Henkel, Hartmut; Klinkner, Sabine

2010-01-01

Hermetically sealing a gas tank and opening it into tubing under telecommand control is a function required in various space instruments. There are a number of space valves that are power saving, withstand vibration, and do not contaminate the gas. But none of them combines these features with low mass and the ability to withstand temperatures of 130 C during the sterilization process mandatory for planetary missions. In this paper, a novel miniature valve is presented, which is particularly adapted to space applications. It is electrically actuated, utilizing a bimetallic snap-disc that pierces a metallic membrane by a needle pin, thereby opening the valve. The design of this single-shot valve is such that it allows it to withstand a temperature of 130 C and a pressure of 50 bars. The valve is also lightweight (6.62 g) and it requires only 9 W to operate.

High-Temperature Optical Window Design

NASA Technical Reports Server (NTRS)

Roeloffs, Norman; Taranto, Nick

1995-01-01

A high-temperature optical window is essential to the optical diagnostics of high-temperature combustion rigs. Laser Doppler velocimetry, schlieren photography, light sheet visualization, and laser-induced fluorescence spectroscopy are a few of the tests that require optically clear access to the combustor flow stream. A design was developed for a high-temperature window that could withstand the severe environment of the NASA Lewis 3200 F Lean Premixed Prevaporized (LPP) Flame Tube Test Rig. The development of this design was both time consuming and costly. This report documents the design process and the lessons learned, in an effort to reduce the cost of developing future designs for high-temperature optical windows.

NDE standards for high temperature materials

NASA Technical Reports Server (NTRS)

Vary, Alex

1991-01-01

High temperature materials include monolithic ceramics for automotive gas turbine engines and also metallic/intermetallic and ceramic matrix composites for a range of aerospace applications. These are materials that can withstand extreme operating temperatures that will prevail in advanced high-efficiency gas turbine engines. High temperature engine components are very likely to consist of complex composite structures with three-dimensionality interwoven and various intermixed ceramic fibers. The thermomechanical properties of components made of these materials are actually created in-place during processing and fabrication stages. The complex nature of these new materials creates strong incentives for exact standards for unambiguous evaluations of defects and microstructural characteristics. NDE techniques and standards that will ultimately be applicable to production and quality control of high temperature materials and structures are still emerging. The needs range from flaw detection to below 100 micron levels in monolithic ceramics to global imaging of fiber architecture and matrix densification anomalies in composites. The needs are different depending on the processing stage, fabrication method, and nature of the finished product. The standards are discussed that must be developed in concert with advances in NDE technology, materials processing research, and fabrication development. High temperature materials and structures that fail to meet stringent specifications and standards are unlikely to compete successfully either technologically or in international markets.

Weather Typing-Based Flood Frequency Analysis Verified for Exceptional Historical Events of Past 500 Years Along the Meuse River

NASA Astrophysics Data System (ADS)

De Niel, J.; Demarée, G.; Willems, P.

2017-10-01

Governments, policy makers, and water managers are pushed by recent socioeconomic developments such as population growth and increased urbanization inclusive of occupation of floodplains to impose very stringent regulations on the design of hydrological structures. These structures need to withstand storms with return periods typically ranging between 1,250 and 10,000 years. Such quantification involves extrapolations of systematically measured instrumental data, possibly complemented by quantitative and/or qualitative historical data and paleoflood data. The accuracy of the extrapolations is, however, highly unclear in practice. In order to evaluate extreme river peak flow extrapolation and accuracy, we studied historical and instrumental data of the past 500 years along the Meuse River. We moreover propose an alternative method for the estimation of the extreme value distribution of river peak flows, based on weather types derived by sea level pressure reconstructions. This approach results in a more accurate estimation of the tail of the distribution, where current methods are underestimating the design levels related to extreme high return periods. The design flood for a 1,250 year return period is estimated at 4,800 m3 s-1 for the proposed method, compared with 3,450 and 3,900 m3 s-1 for a traditional method and a previous study.

High-Temperature Alloys for Automotive Stirling Engines

NASA Technical Reports Server (NTRS)

Stephens, J. R.; Titran, R. H.

1986-01-01

Stirling engine is external-combustion engine that offers fuel economy, low emissions, low noise, and low vibrations. One of most critical areas in engine development concerns material selection for component parts. Alloys CG-27 and XF-818 identified capable of withstanding rigorous requirements of automotive Stirling engine. Alloys chosen for availability, performance, and manufacturability. Advanced iron-base alloys have potential for variety of applications, including stationary solar-power systems.

Fabrication of prepackaged superalloy honeycomb Thermal Protection System (TPS) panels

NASA Technical Reports Server (NTRS)

Blair, W.; Meaney, J. E.; Rosenthal, H. A.

1985-01-01

High temperature materials were surveyed, and Inconel 617 and titanium were selected for application to a honeycomb TPS configuration designed to withstand 2000 F. The configuration was analyzed both thermally and structurally. Component and full-sized panels were fabricated and tested to obtain data for comparison with analysis. Results verified the panel design. Twenty five panels were delivered to NASA Langley Research Center for additional evaluation.

Spark-integrated propellant injector head with flashback barrier

NASA Technical Reports Server (NTRS)

Mungas, Gregory Stuart (Inventor); Fisher, David James (Inventor); Mungas, Christopher (Inventor)

2012-01-01

High performance propellants flow through specialized mechanical hardware that allows for effective and safe thermal decomposition and/or combustion of the propellants. By integrating a sintered metal component between a propellant feed source and the combustion chamber, an effective and reliable fuel injector head may be implemented. Additionally the fuel injector head design integrates a spark ignition mechanism that withstands extremely hot running conditions without noticeable spark mechanism degradation.

Heat Shield Paves the Way for Commercial Space

NASA Technical Reports Server (NTRS)

2014-01-01

The Phenolic-Impregnated Carbon Ablator (PICA) heat shield, a lightweight material designed to withstand high temperatures, was used for the Stardust’s reentry into Earth’s atmosphere. Hawthorne, California-based SpaceX later worked with the inventors at Ames Research Center to outfit PICA on its Dragon capsule, which is now delivering cargo to and from the International Space Station through NASA’s Commercial Resupply Services contracts program.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Jim Landy (left), NDE specialist with United Space Alliance (USA), prepares to examine a Reinforced Carbon Carbon panel using flash thermography. Helping out, at right, is Dan Phillips, also with USA. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, Jim Landy (left), NDE specialist with United Space Alliance (USA), prepares to examine a Reinforced Carbon Carbon panel using flash thermography. Helping out, at right, is Dan Phillips, also with USA. Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, astronaut Michael E. Lopez-Alegria looks at the Reinforced Carbon Carbon panels used on the leading edge of the wing of the orbiters. He and engineers from around the Agency are on a fact-finding tour for improving the RCC panels used on the wing leading edge. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-12-08

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, astronaut Michael E. Lopez-Alegria looks at the Reinforced Carbon Carbon panels used on the leading edge of the wing of the orbiters. He and engineers from around the Agency are on a fact-finding tour for improving the RCC panels used on the wing leading edge. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - - In the Orbiter Processing Facility astronaut Danny Olivas listens to Greg Grantham (left) talking about the Reinforced Carbon Carbon panels used on the leading edge of the wing of the orbiters. Behind Olivas are engineers from around the Agency who are working on improving the RCC panels used on the wing leading edge. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-12-08

KENNEDY SPACE CENTER, FLA. - - In the Orbiter Processing Facility astronaut Danny Olivas listens to Greg Grantham (left) talking about the Reinforced Carbon Carbon panels used on the leading edge of the wing of the orbiters. Behind Olivas are engineers from around the Agency who are working on improving the RCC panels used on the wing leading edge. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, astronaut Scott E. Parazynski points to the Reinforced Carbon Carbon panels used on the leading edge of the wing of the orbiters. With Parazynski are engineers from around the Agency who are working on improving the RCC panels used on the wing leading edge. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-12-08

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, astronaut Scott E. Parazynski points to the Reinforced Carbon Carbon panels used on the leading edge of the wing of the orbiters. With Parazynski are engineers from around the Agency who are working on improving the RCC panels used on the wing leading edge. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, astronaut Scott E. Parazynski discusses the Reinforced Carbon Carbon panels used on the leading edge of the wing of the orbiters. With him are engineers from around the Agency who are working on improving the RCC panels used on the wing leading edge. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-12-08

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, astronaut Scott E. Parazynski discusses the Reinforced Carbon Carbon panels used on the leading edge of the wing of the orbiters. With him are engineers from around the Agency who are working on improving the RCC panels used on the wing leading edge. The gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

Highly Robust Neutral Plane Oxide TFTs Withstanding 0.25 mm Bending Radius for Stretchable Electronics

PubMed Central

Kim, Yong-Hwan; Lee, Eunji; Um, Jae Gwang; Mativenga, Mallory; Jang, Jin

2016-01-01

Advancements in thin-film transistor (TFT) technology have extended to electronics that can withstand extreme bending or even folding. Although the use of ultrathin plastic substrates has achieved considerable advancement towards this end, free-standing ultrathin plastics inevitably suffer from mechanical instability and are very difficult to handle during TFT fabrication. Here, in addition to the use of a 1.5 μm-thick polyimide (PI) substrate, a 1.5 μm-thick PI film is also deposited on top of the TFT devices to ensure that the devices are located at the neutral plane of the two PI films for high folding stability. For mechanical support during TFT fabrication up to the deposition of the top PI film, the PI substrate is spin coated on top of a carrier glass that is coated with a mixture of carbon nanotubes (CNTs) and graphene oxide (GO). The mixture of CNT and GO facilitates mechanical detachment of the neutral plane (NP) TFTs from the carrier glass before they are transferred to a polydimethylsiloxane (PDMS) substrate as islands. Being located in the neutral bending plane, the NP TFT can be transferred to the PDMS without performance degradation and exhibit excellent mechanical stability after stretching the PDMS substrate up to a 25% elastic elongation. PMID:27165715

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers (left to right) Jim Landy, Dan Phillips, Paul Ogletree and Dan Kenna check results of flash thermography on the Reinforced Carbon Carbon panel on the table (foreground). Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers (left to right) Jim Landy, Dan Phillips, Paul Ogletree and Dan Kenna check results of flash thermography on the Reinforced Carbon Carbon panel on the table (foreground). Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers (left to right) Jim Landy, Paul Ogletree, Dan Kenna and Dan Phillips check results of flash thermography on the Reinforced Carbon Carbon panel on the table (foreground). Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

NASA Image and Video Library

2003-09-09

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, United Space Alliance workers (left to right) Jim Landy, Paul Ogletree, Dan Kenna and Dan Phillips check results of flash thermography on the Reinforced Carbon Carbon panel on the table (foreground). Attached to the leading edge of the wing of the orbiters, the gray carbon composite RCC panels have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry.

Modal Analysis with the Mobile Modal Testing Unit

NASA Technical Reports Server (NTRS)

Wilder, Andrew J.

2013-01-01

Recently, National Aeronautics and Space Administration's (NASA's) White Sands Test Facility (WSTF) has tested rocket engines with high pulse frequencies. This has resulted in the use of some of WSTF's existing thrust stands, which were designed for static loading, in tests with large dynamic forces. In order to ensure that the thrust stands can withstand the dynamic loading of high pulse frequency engines while still accurately reporting the test data, their vibrational modes must be characterized. If it is found that they have vibrational modes with frequencies near the pulsing frequency of the test, then they must be modified to withstand the dynamic forces from the pulsing rocket engines. To make this determination the Mobile Modal Testing Unit (MMTU), a system capable of determining the resonant frequencies and mode shapes of a structure, was used on the test stands at WSTF. Once the resonant frequency has been determined for a test stand, it can be compared to the pulse frequency of a test engine to determine whether or not that stand can avoid resonance and reliably test that engine. After analysis of test stand 406 at White Sands Test Facility, it was determined that natural frequencies for the structure are located around 75, 125, and 240 Hz, and thus should be avoided during testing.

High-Temperature Surface-Acoustic-Wave Transducer

NASA Technical Reports Server (NTRS)

Zhao, Xiaoliang; Tittmann, Bernhard R.

2010-01-01

Aircraft-engine rotating equipment usually operates at high temperature and stress. Non-invasive inspection of microcracks in those components poses a challenge for the non-destructive evaluation community. A low-profile ultrasonic guided wave sensor can detect cracks in situ. The key feature of the sensor is that it should withstand high temperatures and excite strong surface wave energy to inspect surface/subsurface cracks. As far as the innovators know at the time of this reporting, there is no existing sensor that is mounted to the rotor disks for crack inspection; the most often used technology includes fluorescent penetrant inspection or eddy-current probes for disassembled part inspection. An efficient, high-temperature, low-profile surface acoustic wave transducer design has been identified and tested for nondestructive evaluation of structures or materials. The development is a Sol-Gel bismuth titanate-based surface-acoustic-wave (SAW) sensor that can generate efficient surface acoustic waves for crack inspection. The produced sensor is very thin (submillimeter), and can generate surface waves up to 540 C. Finite element analysis of the SAW transducer design was performed to predict the sensor behavior, and experimental studies confirmed the results. One major uniqueness of the Sol-Gel bismuth titanate SAW sensor is that it is easy to implement to structures of various shapes. With a spray coating process, the sensor can be applied to surfaces of large curvatures. Second, the sensor is very thin (as a coating) and has very minimal effect on airflow or rotating equipment imbalance. Third, it can withstand temperatures up to 530 C, which is very useful for engine applications where high temperature is an issue.

Estimation of genetic parameters and breeding values across challenged environments to select for robust pigs.

PubMed

Herrero-Medrano, J M; Mathur, P K; ten Napel, J; Rashidi, H; Alexandri, P; Knol, E F; Mulder, H A

2015-04-01

Robustness is an important issue in the pig production industry. Since pigs from international breeding organizations have to withstand a variety of environmental challenges, selection of pigs with the inherent ability to sustain their productivity in diverse environments may be an economically feasible approach in the livestock industry. The objective of this study was to estimate genetic parameters and breeding values across different levels of environmental challenge load. The challenge load (CL) was estimated as the reduction in reproductive performance during different weeks of a year using 925,711 farrowing records from farms distributed worldwide. A wide range of levels of challenge, from favorable to unfavorable environments, was observed among farms with high CL values being associated with confirmed situations of unfavorable environment. Genetic parameters and breeding values were estimated in high- and low-challenge environments using a bivariate analysis, as well as across increasing levels of challenge with a random regression model using Legendre polynomials. Although heritability estimates of number of pigs born alive were slightly higher in environments with extreme CL than in those with intermediate levels of CL, the heritabilities of number of piglet losses increased progressively as CL increased. Genetic correlations among environments with different levels of CL suggest that selection in environments with extremes of low or high CL would result in low response to selection. Therefore, selection programs of breeding organizations that are commonly conducted under favorable environments could have low response to selection in commercial farms that have unfavorable environmental conditions. Sows that had experienced high levels of challenge at least once during their productive life were ranked according to their EBV. The selection of pigs using EBV ignoring environmental challenges or on the basis of records from only favorable environments resulted in a sharp decline in productivity as the level of challenge increased. In contrast, selection using the random regression approach resulted in limited change in productivity with increasing levels of challenge. Hence, we demonstrate that the use of a quantitative measure of environmental CL and a random regression approach can be comprehensively combined for genetic selection of pigs with enhanced ability to maintain high productivity in harsh environments.

Redox signaling and stress tolerance in plants: a focus on vitamin E.

PubMed

Miret, Javier A; Munné-Bosch, Sergi

2015-03-01

Plants are subject to specific redox processes, in which photosynthesis plays a prominent role. Chloroplasts function in light at high oxygen tensions and are enormous generators of reactive oxygen species, mainly singlet oxygen. This side product of photosynthesis inflicts damage to thylakoid membranes at high concentrations, but at the same time it is an essential component of cellular signaling. Detoxification of singlet oxygen is achieved by different means, including quenching and scavenging by tocopherols, responsible for controlling singlet oxygen levels, and the extent of lipid peroxidation in chloroplasts. Here, environmental conditions leading to excess light in chloroplasts will be used to show the importance of singlet oxygen, tocopherols, and lipid peroxidation in cell signaling. Defects in antioxidant protection (e.g., tocopherol deficiency) can lead to increased photo-oxidative damage, but also to the activation of defense pathways, illustrating the phenotypic plasticity evolved by plants to withstand stress. Most importantly, these studies show how redox signaling processes are integrated within the cell and illustrate the great capacity of plants to adapt to their environment. © 2015 New York Academy of Sciences.

Damage of actively cooled plasma facing components of magnetic confinement controlled fusion machines

NASA Astrophysics Data System (ADS)

Chevet, G.; Schlosser, J.; Martin, E.; Herb, V.; Camus, G.

2009-03-01

Plasma facing components (PFCs) of magnetic fusion machines have high manufactured residual stresses and have to withstand important stress ranges during operation. These actively cooled PFCs have a carbon fibre composite (CFC) armour and a copper alloy heat sink. Cracks mainly appear in the CFC near the composite/copper interface. In order to analyse damage mechanisms, it is important to well simulate the damage mechanisms both of the CFC and the CFC/Cu interface. This study focuses on the mechanical behaviour of the N11 material for which the scalar ONERA damage model was used. The damage parameters of this model were identified by similarity to a neighbour material, which was extensively analysed, according to the few characterization test results available for the N11. The finite elements calculations predict a high level of damage of the CFC at the interface zone explaining the encountered difficulties in the PFCs fabrication. These results suggest that the damage state of the CFC cells is correlated with a conductivity decrease to explain the temperature increase of the armour surface under fatigue heat load.

Final Environmental Impact Statement (EIS) for the Space Nuclear Thermal Propulsion (SNTP) program

NASA Astrophysics Data System (ADS)

1991-09-01

A program has been proposed to develop the technology and demonstrate the feasibility of a high-temperature particle bed reactor (PBR) propulsion system to be used to power an advanced second stage nuclear rocket engine. The purpose of this Final Environmental Impact Statement (FEIS) is to assess the potential environmental impacts of component development and testing, construction of ground test facilities, and ground testing. Major issues and goals of the program include the achievement and control of predicted nuclear power levels; the development of materials that can withstand the extremely high operating temperatures and hydrogen flow environments; and the reliable control of cryogenic hydrogen and hot gaseous hydrogen propellant. The testing process is designed to minimize radiation exposure to the environment. Environmental impact and mitigation planning are included for the following areas of concern: (1) Population and economy; (2) Land use and infrastructure; (3) Noise; (4) Cultural resources; (5) Safety (non-nuclear); (6) Waste; (7) Topography; (8) Geology; (9) Seismic activity; (10) Water resources; (11) Meteorology/Air quality; (12) Biological resources; (13) Radiological normal operations; (14) Radiological accidents; (15) Soils; and (16) Wildlife habitats.

A highly stable monolithic enhancement cavity for second harmonic generation in the ultraviolet

NASA Astrophysics Data System (ADS)

Hannig, S.; Mielke, J.; Fenske, J. A.; Misera, M.; Beev, N.; Ospelkaus, C.; Schmidt, P. O.

2018-01-01

We present a highly stable bow-tie power enhancement cavity for critical second harmonic generation (SHG) into the UV using a Brewster-cut β-BaB2O4 (BBO) nonlinear crystal. The cavity geometry is suitable for all UV wavelengths reachable with BBO and can be modified to accommodate anti-reflection coated crystals, extending its applicability to the entire wavelength range accessible with non-linear frequency conversion. The cavity is length-stabilized using a fast general purpose digital PI controller based on the open source STEMlab 125-14 (formerly Red Pitaya) system acting on a mirror mounted on a fast piezo actuator. We observe 130 h uninterrupted operation without decay in output power at 313 nm. The robustness of the system has been confirmed by exposing it to accelerations of up to 1 g with less than 10% in-lock output power variations. Furthermore, the cavity can withstand 30 min of acceleration exposure at a level of 3 grms without substantial change in the SHG output power, demonstrating that the design is suitable for transportable setups.

Development of a low loss magnetic composite utilizing amorphous metal flake. Second semi-annual progress report, March 19-September 18, 1979

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

Not Available

1979-10-01

Composite specimens of amorphous metal flakes have been made using several different binders and several different compaction parameters. The binders have included epoxies, anaerobic adhesives, polyimides, polyamideimides, polyeherimides, and polyesterimides. Compaction variables included the time, temperature and pressure of compaction; flake size, and flake alignment. The best results were achieved using a polyetherimide and aligned flake. Packing factors of 87% were achieved in specimens which also exhibited high mechanical integrity and the ability to withstand a high temperature anneal.

Broadband low-dispersion low-nonlinearity photonic crystal fiber dedicated to near-infrared high-power femtosecond pulse delivery

NASA Astrophysics Data System (ADS)

Hoang, Van Thuy; Siwicki, Bartłomiej; Franczyk, Marcin; Stępniewski, Grzegorz; Van, Hieu Le; Long, Van Cao; Klimczak, Mariusz; Buczyński, Ryszard

2018-05-01

A low-dispersion and low-nonlinearity silica photonic crystal fiber is designed and developed. The investigated fiber is effectively single-mode and has low dispersion -20 to 40 ps/nm/km in the 1-1.7 μm wavelength range. The silica PCF can withstand a 1017 nm QCW laser beam with a maximum tested power of 9.1 W. The investigated PCF with NA = 0.15 is suggested as a promising medium for a high-power femtosecond undistorted pulse delivery in the near-infrared region.

Comparison of alcogas aviation fuel with export aviation gasoline

NASA Technical Reports Server (NTRS)

Gage, V R; Sparrow, S W; Harper, D R

1921-01-01

Mixtures of gasoline and alcohol when used in internal combustion engines designed for gasoline have been found to possess the advantage of alcohol in withstanding high compression without "knock" while retaining advantages of gasoline with regard to starting characteristics. Test of such fuels for maximum power-producing ability and fuel economy at various rates of consumption are thus of practical importance, with especial reference to high-compression engine development. This report discusses the results of tests which compares the performance of alcogas with x gasoline (export grade) as a standard.

METHOD AND APPARATUS FOR PRODUCING POWER

DOEpatents

Wollan, E.O.

1961-06-27

A neutronic reactor comprising two discrete zones; namely, an inner zone containing fissionable material and an outer zone containing fertile material is described. The inner zone is operated at a low temperature and is cooled by pressurized water. The outer zone is operated at a substantially higher temperature and is cooled by steam flashed from the inner zone. The reactor is particularly advantageous in that it produces high temperature steam; yet the materials of construction in the core (inner zone) are not restricted to materials capable of withstanding high temperature operation.

High temperature antenna development for space shuttle, volume 2. [space environment simulation effects on antenna radiation patterns

NASA Technical Reports Server (NTRS)

Kuhlman, E. A.

1974-01-01

An S-band antenna system and a group of off-the-shelf aircraft antenna were exposed to temperatures simulating shuttle orbital cold soak and entry heating. Radiation pattern and impedance measurements before and after exposure to the thermal environments were used to evaluate the electrical performance. The results of the electrical and thermal testing are given. Test data showed minor changes in electrical performance and established the capability of these antenna to withstand both the low temperatures of space flight and the high temperatures of entry.

CFD and Thermo Mechanical Analysis on Effect of Curved vs Step Surface in IC Engine Cylinder Head

NASA Astrophysics Data System (ADS)

Balaji, S.; Ganesh, N.; Kumarasamy, A.

2017-05-01

Current research in IC engines mainly focus on various methods to achieve higher efficiency and high specific power. As a single design parameter, combustion chamber peak spring pressure has increased more than before. Apart from the structural aspects of withstanding these loads, designer faces challenges of resolving thermal aspects of cylinder head. Methods to enhance the heat transfer without compromising load withstanding capability are being constantly explored. Conventional cylinder heads have got sat inner surface. In this paper we have suggested a modification in inner surface to enhance the heat transfer capability. To increase the heat transfer rate, inner same deck surface is configured as a curved and stepped surface instead of sat. We have reported the effectiveness of extend of curvature in the inner same deck surface in a different technical paper. Here, we are making a direct comparison between stepped and curved surface only. From this analysis it has been observed that curved surface reduces the ame deck temperature considerably without compromising the structural strength factors compared to step and sat surface.

PHOSPHO1 is essential for mechanically competent mineralization and the avoidance of spontaneous fractures

PubMed Central

Huesa, Carmen; Yadav, Manisha C.; Finnilä, Mikko A.J.; Goodyear, Simon R.; Robins, Simon P.; Tanner, K. Elizabeth; Aspden, Richard M.; Millán, José Luis; Farquharson, Colin

2011-01-01

Phosphatases are essential for the mineralization of the extracellular matrix within the skeleton. Their precise identities and functions however remain unclear. PHOSPHO1 is a phosphoethanolamine/phosphocholine phosphatase involved in the generation of inorganic phosphate for bone mineralization. It is highly expressed at sites of mineralization in bone and cartilage. The bones of Phospho1−/− mice are hypomineralized, bowed and present with spontaneous greenstick fractures at birth. In this study we show that PHOSPHO1 is essential for mechanically competent mineralization that is able to withstand habitual load. Long bones from Phospho1−/− mice did not fracture during 3- point bending but deformed plastically. With dynamic loading nanoindentation the elastic modulus and hardness of Phospho1−/− tibiae were significantly lower than wild-type tibia. Raman microscopy revealed significantly lower mineral:matrix ratios and lower carbonate substitutions in Phospho1−/− tibia. The altered dihydroxylysinonorleucine/hydroxyllysinonorleucine and pyridoline/deoxypyridinoline collagen crosslink ratios indicated possible changes in lysyl hydroxylase-1 activity and/or bone mineralization status. The bone formation and resorption markers, N-terminal propeptide and C-terminal telopeptide of Type I collagen, were both increased in Phospho1−/− mice and this we associated with increased bone remodelling during fracture repair or an attempt to remodel a mechanically competent bone capable of withstanding physiological load. In summary these data indicate that Phospho1−/− bones are hypomineralized and, consequently, are softer and more flexible. An inability to withstand physiological loading may explain the deformations noted. We hypothesize that this phenotype is due to the reduced availability of inorganic phosphate to form hydroxyapatite during mineralization, creating an undermineralized yet active bone. PMID:21272676

The feasibility of a high-altitude aircraft platform with consideration of technological and societal constraints. Thesis - Kansas Univ.

NASA Technical Reports Server (NTRS)

Graves, E. B.

1982-01-01

The feasibility of remotely piloted aircraft performing year around missions at an altitude of 70,000 feet is determined. Blimp and airplane type vehicles employing solar-voltaic, microwave, or nuclear propulsion systems were considered. A payload weighing 100 pounds and requiring 1000 watts of continuous power was assumed for analysis purposes. Results indicate that a solar powered aircraft requires more solar cell area than is available on conventional aircraft configurations if designed for the short days and high wind speeds associated with the winter season. A conventionally shaped blimp that uses solar power appears feasible if maximum airspeed is limited to about 100 ft/s. No viable airplane configuration that uses solar power and designed to withstand the winter environment was found. Both a conventionally shaped blimp and airplane appear feasible using microwave power. Nuclear powered aircraft of these type are also feasible. Societal attitudes toward the use of solar power in high altitude aircraft appear favorable. The use of microwave power for this purpose is controversial, even though the ground station required would transmit power at levels comparable to existing satellite communications stations.

Process for diffusing metallic coatings into ceramics to improve their voltage withstanding capabilities

DOEpatents

Miller, H. Craig; Zuhr, Herbert F.

1978-01-01

The disclosure relates to a method for diffusing a coating of manganese powder and titanium powder into a ceramic to improve its voltage hold off withstanding capability. The powder coated ceramic is fired for from about 30 to about 90 minutes within about one atmosphere of wet hydrogen at a temperature within the range of from about 1450.degree. to about 1520.degree. C to cause the mixture to penetrate into the ceramic to a depth on the order of a millimeter.

Habitat traits and food availability determine the response of marine invertebrates to ocean acidification.

PubMed

Pansch, Christian; Schaub, Iris; Havenhand, Jonathan; Wahl, Martin

2014-03-01

Energy availability and local adaptation are major components in mediating the effects of ocean acidification (OA) on marine species. In a long-term study, we investigated the effects of food availability and elevated pCO2 (ca. 400, 1000 and 3000 μatm) on growth of newly settled Amphibalanus (Balanus) improvisus to reproduction, and on their offspring. We also compared two different populations, which were presumed to differ in their sensitivity to pCO2 due to differing habitat conditions: Kiel Fjord, Germany (Western Baltic Sea) with naturally strong pCO2 fluctuations, and the Tjärnö Archipelago, Sweden (Skagerrak) with far lower fluctuations. Over 20 weeks, survival, growth, reproduction and shell strength of Kiel barnacles were all unaffected by elevated pCO2 , regardless of food availability. Moulting frequency and shell corrosion increased with increasing pCO2 in adults. Larval development and juvenile growth of the F1 generation were tolerant to increased pCO2 , irrespective of parental treatment. In contrast, elevated pCO2 had a strong negative impact on survival of Tjärnö barnacles. Specimens from this population were able to withstand moderate levels of elevated pCO2 over 5 weeks when food was plentiful but showed reduced growth under food limitation. Severe levels of elevated pCO2 negatively impacted growth of Tjärnö barnacles in both food treatments. We demonstrate a conspicuously higher tolerance to elevated pCO2 in Kiel barnacles than in Tjärnö barnacles. This tolerance was carried over from adults to their offspring. Our findings indicate that populations from fluctuating pCO2 environments are more tolerant to elevated pCO2 than populations from more stable pCO2 habitats. We furthermore provide evidence that energy availability can mediate the ability of barnacles to withstand moderate CO2 stress. Considering the high tolerance of Kiel specimens and the possibility to adapt over many generations, near future OA alone does not seem to present a major threat for A. improvisus. © 2013 John Wiley & Sons Ltd.

Survival in Nuclear Waste, Extreme Resistance, and Potential Applications Gleaned from the Genome Sequence of Kineococcus radiotolerans SRS30216

PubMed Central

Bagwell, Christopher E.; Bhat, Swapna; Hawkins, Gary M.; Smith, Bryan W.; Biswas, Tapan; Hoover, Timothy R.; Saunders, Elizabeth; Han, Cliff S.; Tsodikov, Oleg V.; Shimkets, Lawrence J.

2008-01-01

Kineococcus radiotolerans SRS30216 was isolated from a high-level radioactive environment at the Savannah River Site (SRS) and exhibits γ-radiation resistance approaching that of Deinococcus radiodurans. The genome was sequenced by the U.S. Department of Energy's Joint Genome Institute which suggested the existence of three replicons, a 4.76 Mb linear chromosome, a 0.18 Mb linear plasmid, and a 12.92 Kb circular plasmid. Southern hybridization confirmed that the chromosome is linear. The K. radiotolerans genome sequence was examined to learn about the physiology of the organism with regard to ionizing radiation resistance, the potential for bioremediation of nuclear waste, and the dimorphic life cycle. K. radiotolerans may have a unique genetic toolbox for radiation protection as it lacks many of the genes known to confer radiation resistance in D. radiodurans. Additionally, genes involved in the detoxification of reactive oxygen species and the excision repair pathway are overrepresented. K. radiotolerans appears to lack degradation pathways for pervasive soil and groundwater pollutants. However, it can respire on two organic acids found in SRS high-level nuclear waste, formate and oxalate, which promote the survival of cells during prolonged periods of starvation. The dimorphic life cycle involves the production of motile zoospores. The flagellar biosynthesis genes are located on a motility island, though its regulation could not be fully discerned. These results highlight the remarkable ability of K radiotolerans to withstand environmental extremes and suggest that in situ bioremediation of organic complexants from high level radioactive waste may be feasible. PMID:19057647

Forming Refractory Insulation On Copper Wire

NASA Technical Reports Server (NTRS)

Setlock, J.; Roberts, G.

1995-01-01

Alternative insulating process forms flexible coat of uncured refractory insulating material on copper wire. Coated wire formed into coil or other complex shape. Wire-coating apparatus forms "green" coat on copper wire. After wire coiled, heating converts "green" coat to refractory electrical insulator. When cured to final brittle form, insulating material withstands temperatures above melting temperature of wire. Process used to make coils for motors, solenoids, and other electrical devices to be operated at high temperatures.

Method for fabricating a seal between a ceramic and a metal alloy

DOEpatents

Kelsey, Jr., Paul V.; Siegel, William T.

1983-01-01

A method of fabricating a seal between a ceramic and an alloy comprising the steps of prefiring the alloy in an atmosphere with a very low partial pressure of oxygen, firing the assembled alloy and ceramic in air, and gradually cooling the fired assembly to avoid the formation of thermal stress in the ceramic. The method forms a bond between the alloy and the ceramic capable of withstanding the environment of a pressurized water reactor and suitable for use in an electrical conductivity sensitive liquid level transducer.

Structural interaction with transportation and handling systems

NASA Technical Reports Server (NTRS)

1973-01-01

Problems involved in the handling and transportation of finished space vehicles from the factory to the launch site are presented, in addition to recommendations for properly accounting for in space vehicle structural design, adverse interactions during transportation. Emphasis is given to the protection of vehicle structures against those environments and loads encountered during transportation (including temporary storage) which would exceed the levels that the vehicle can safely withstand. Current practices for verifying vehicle safety are appraised, and some of the capabilities and limitations of transportation and handling systems are summarized.

Method for fabricating a seal between a ceramic and a metal alloy

DOEpatents

Kelsey, P.V. Jr.; Siegel, W.T.

1983-08-16

A method of fabricating a seal between a ceramic and an alloy comprising the steps of prefiring the alloy in an atmosphere with a very low partial pressure of oxygen, firing the assembled alloy and ceramic in air, and gradually cooling the fired assembly to avoid the formation of thermal stress in the ceramic. The method forms a bond between the alloy and the ceramic capable of withstanding the environment of a pressurized water reactor and suitable for use in an electrical conductivity sensitive liquid level transducer.

Smart-actuated continuous moldline technology (CMT) mini wind tunnel test

NASA Astrophysics Data System (ADS)

Pitt, Dale M.; Dunne, James P.; Kilian, Kevin J.

1999-07-01

The Smart Aircraft and Marine Propulsion System Demonstration (SAMPSON) Program will culminate in two separate demonstrations of the application of Smart Materials and Structures technology. One demonstration will be for an aircraft application and the other for marine vehicles. The aircraft portion of the program will examine the application of smart materials to aircraft engine inlets which will deform the inlet in-flight in order to regulate the airflow rate into the engine. Continuous Moldline Technology (CMT), a load-bearing reinforced elastomer, will enable the use of smart materials in this application. The capabilities of CMT to withstand high-pressure subsonic and supersonic flows were tested in a sub-scale mini wind- tunnel. The fixture, used as the wind-tunnel test section, was designed to withstand pressure up to 100 psi. The top and bottom walls were 1-inch thick aluminum and the side walls were 1-inch thick LEXAN. High-pressure flow was introduced from the Boeing St. Louis poly-sonic wind tunnel supply line. CMT walls, mounted conformal to the upper and lower surfaces, were deflected inward to obtain a converging-diverging nozzle. The CMT walls were instrumented for vibration and deflection response. Schlieren photography was used to establish shock wave motion. Static pressure taps, embedded within one of the LEXAN walls, monitored pressure variation in the mini-wind tunnel. High mass flow in the exit region. This test documented the response of CMT technology in the presence of high subsonic flow and provided data to be used in the design of the SAMPSON Smart Inlet.

Hypolipidaemic and anti-oxidative potential of encapsulated herb (Terminalia arjuna) added vanilla chocolate milk in high cholesterol fed rats.

PubMed

Sawale, Pravin Digambar; Pothuraju, Ramesh; Abdul Hussain, Shaik; Kumar, Anuj; Kapila, Suman; Patil, Girdhari Ramdas

2016-03-15

Atherosclerosis is associated with coronary artery disease and occurs in developing as well as developed countries. In the present investigation, hypolipidaemic and anti-oxidative properties of encapsulated herb (Terminalia arjuna, 1.8%) added vanilla chocolate dairy drink was evaluated in high cholesterol fed Wistar rats for 60 days. At the end of the experimental period, a significant decrease in the body weight gain by rats receiving the encapsulated herb extract was noted as compared to high cholesterol fed rats. Administration of microencapsulated herb showed a statistically significant decrease in organ weights (epididymal fat and liver). Moreover, a significant decrease in serum lipids such as triglycerides, total cholesterol, low-density lipoprotein cholesterol, very-low-density lipoprotein cholesterol and atherogenic index was observed with encapsulated Terminalia arjuna extract in high cholesterol fed group. Increases in reduced glutathione and decreases in TBARS levels were also reported in both liver and red blood cell lysates with encapsulated herb supplementation. The results demonstrated that the bioactive components (phytosterols, flavanoids, saponins and tannins etc.) which are present in the encapsulated T. arjuna not only withstand the processing conditions but also are effectively released in the intestine and show their effects, such as hypolipidaemic and antioxidant activities, for better treating cardiovascular disease. © 2015 Society of Chemical Industry.

Studies of $${\\rm Nb}_{3}{\\rm Sn}$$ Strands Based on the Restacked-Rod Process for High Field Accelerator Magnets

DOE PAGES

Barzi, E.; Bossert, M.; Gallo, G.; ...

2011-12-21

A major thrust in Fermilab's accelerator magnet R&D program is the development of Nb 3Sn wires which meet target requirements for high field magnets, such as high critical current density, low effective filament size, and the capability to withstand the cabling process. The performance of a number of strands with 150/169 restack design produced by Oxford Superconducting Technology was studied for round and deformed wires. To optimize the maximum plastic strain, finite element modeling was also used as an aid in the design. Results of mechanical, transport and metallographic analyses are presented for round and deformed wires.

Fault current limiter

DOEpatents

Darmann, Francis Anthony

2013-10-08

A fault current limiter (FCL) includes a series of high permeability posts for collectively define a core for the FCL. A DC coil, for the purposes of saturating a portion of the high permeability posts, surrounds the complete structure outside of an enclosure in the form of a vessel. The vessel contains a dielectric insulation medium. AC coils, for transporting AC current, are wound on insulating formers and electrically interconnected to each other in a manner such that the senses of the magnetic field produced by each AC coil in the corresponding high permeability core are opposing. There are insulation barriers between phases to improve dielectric withstand properties of the dielectric medium.

Development of CVD mullite coatings for Si-based ceramics

NASA Astrophysics Data System (ADS)

Auger, Michael Lawrence

1999-09-01

To raise fuel efficiencies, the next generation of engines and fuel systems must be lighter and operate at higher temperatures. Ceramic-based materials, which are considerably lighter than metals and can withstand working temperatures of up to 1400sp°C, have been targeted to replace traditional metal-based components. The materials used in combustion environments must also be capable of withstanding erosion and corrosion caused by combustion gases, particulates, and deposit-forming corrodants. With these demanding criteria, silicon-based ceramics are the leading candidate materials for high temperature engine and heat exchanger structural components. However, these materials are limited in gaseous environments and in the presence of molten salts since they form liquid silicates on exposed surfaces at temperatures as low as 800sp°C. Protective coatings that can withstand higher operating temperatures and corrosive atmospheres must be developed for silicon-based ceramics. Mullite (3Alsb2Osb3{*}2SiOsb2) was targeted as a potential coating material due to its unique ability to resist corrosion, retain its strength, resist creep, and avoid thermal shock failure at elevated temperatures. Several attempts to deposit mullite coatings by various processing methods have met with limited success and usually resulted in coatings that have had pores, cracks, poor adherence, and required thermal post-treatments. To overcome these deficiencies, the direct formation of chemically vapor deposited (CVD) mullite coatings has been developed. CVD is a high temperature atomistic deposition technique that results in dense, adherent crystalline coatings. The object of this dissertation was to further the understanding of the CVD mullite deposition process and resultant coating. The kinetics of CVD mullite deposition were investigated as a function of the following process parameters: temperature, pressure, and the deposition reactor system. An empirical kinetic model was developed indicating that an intermediate gaseous reaction is significant to the growth rate of mullite. CVD mullite coatings were deposited on SiC and Sisb3Nsb4 substrates and subjected to both simulated coal gasification and simulated jet fuel combustion conditions. Corrosion resistance of CVD mullite coated ceramics was superior to traditional refractory materials including alumina, solid mullite, Sisb3Nsb4, and silicon carbide.

Making Ceramic Components For Advanced Aircraft Engines

NASA Technical Reports Server (NTRS)

Franklin, J. E.; Ezis, A.

1994-01-01

Lightweight, oxidation-resistant silicon nitride components containing intricate internal cooling and hydraulic passages and capable of withstanding high operating temperatures made by ceramic-platelet technology. Used to fabricate silicon nitride test articles of two types: components of methane-cooled regenerator for air turbo ramjet engine and components of bipropellant injector for rocket engine. Procedures for development of more complex and intricate components established. Technology has commercial utility in automotive, aircraft, and environmental industries for manufacture of high-temperature components for use in regeneration of fuels, treatment of emissions, high-temperature combustion devices, and application in which other high-temperature and/or lightweight components needed. Potential use in fabrication of combustors and high-temperature acoustic panels for suppression of noise in future high-speed aircraft.

New Data for Modeling Hypersonic Entry into Earth's Atmosphere: Electron-impact Ionization of Atomic Nitrogen

NASA Astrophysics Data System (ADS)

Savin, Daniel Wolf; Ciccarino, Christopher

2017-06-01

Meteors passing through Earth’s atmosphere and space vehicles returning to Earth from beyond orbit enter the atmosphere at hypersonic velocities (greater than Mach 5). The resulting shock front generates a high temperature reactive plasma around the meteor or vehicle (with temperatures greater than 10,000 K). This intense heat is transferred to the entering object by radiative and convective processes. Modeling the processes a meteor undergoes as it passes through the atmosphere and designing vehicles to withstand these conditions requires an accurate understanding of the underlying non-equilibrium high temperature chemistry. Nitrogen chemistry is particularly important given the abundance of nitrogen in Earth's atmosphere. Line emission by atomic nitrogen is a major source of radiative heating during atomspheric entry. Our ability to accurately calculate this heating is hindered by uncertainties in the electron-impact ionization (EII) rate coefficient for atomic nitrogen.Here we present new EII calculations for atomic nitrogen. The atom is treated as a 69 level system, incorporating Rydberg values up to n=20. Level-specific cross sections are from published B-Spline R-Matrix-with-Pseudostates results for the first three levels and binary-encounter Bethe (BEB) calculations that we have carried out for the remaining 59 levels. These cross section data have been convolved into level-specific rate coefficients and fit with the commonly-used Arrhenius-Kooij formula for ease of use in hypersonic chemical models. The rate coefficient data can be readily scaled by the relevant atomic nitrogen partition function which varies in time and space around the meteor or reentry vehicle. Providing data up to n=20 also enables modelers to account for the density-dependent lowering of the continuum.

Microvascular responses to (hyper-)gravitational stress by short-arm human centrifuge: arteriolar vasoconstriction and venous pooling.

PubMed

Habazettl, H; Stahn, Alexander; Nitsche, Andrea; Nordine, Michael; Pries, A R; Gunga, H-C; Opatz, O

2016-01-01

We hypothesized that lower body microvessels are particularly challenged during exposure to gravity and hypergravity leading to failure of resistance vessels to withstand excessive transmural pressure during hypergravitation and gravitation-dependent microvascular blood pooling. Using a short-arm human centrifuge (SAHC), 12 subjects were exposed to +1Gz, +2Gz and +1Gz, all at foot level, for 4 min each. Laser Doppler imaging and near-infrared spectroscopy were used to measure skin perfusion and tissue haemoglobin concentrations, respectively. Pretibial skin perfusion decreased by 19% during +1Gz and remained at this level during +2Gz. In the dilated area, skin perfusion increased by 24 and 35% during +1Gz and +2Gz, respectively. In the upper arm, oxygenated haemoglobin (Hb) decreased, while deoxy Hb increased with little change in total Hb. In the calf muscle, O2Hb and deoxy Hb increased, resulting in total Hb increase by 7.5 ± 1.4 and 26.6 ± 2.6 µmol/L at +1Gz and +2Gz, respectively. The dynamics of Hb increase suggests a fast and a slow component. Despite transmural pressures well beyond the upper myogenic control limit, intact lower body resistance vessels withstand these pressures up to +2Gz, suggesting that myogenic control may contribute only little to increased vascular resistance. The fast component of increasing total Hb indicates microvascular blood pooling contributing to soft tissue capacitance. Future research will have to address possible alterations of these acute adaptations to gravity after deconditioning by exposure to micro-g.

High pressure, energy, and impulse loading of the wall in a 1-GJ Laboratory Microfusion Facility

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

Harrach, R.J.

1989-07-24

A proposed Laboratory Microfusion Facility (LMF) must be able to withstand repeated, low-repetition-rate fusion explosions at the 1-GJ (one-quarter ton) yield level. The energy release will occur at the center of a chamber only a few meters in radius, subjecting the interior or first wall to severe levels of temperature, pressure, and impulse. We show by theory and computation that the wall loading can be ameliorated by interposing a spherical shell of low-Z material between the fuel and the wall. This sacrificial shield converts the source energy components that are most damaging to the wall (soft x-rays and fast ions)more » to more benign plasma kinetic energy from the vaporized shield, and stretches the time duration over which this energy is delivered to the wall from nanoseconds to microseconds. Numerical calculations emphasize thin, volleyball-sized plastic shields, and much thicker ones of frozen nitrogen. Wall shielding criteria of small (or no) amount of surface ablation, low impulse and pressure loading, minimal shrapnel danger, small expense, and convenience in handling all favor the thin plastic shields. 7 refs., 4 figs.« less

Multigenerational exposure to ocean acidification during food limitation reveals consequences for copepod scope for growth and vital rates.

PubMed

Pedersen, Sindre A; Håkedal, Ole Jacob; Salaberria, Iurgi; Tagliati, Alice; Gustavson, Liv Marie; Jenssen, Bjørn Munro; Olsen, Anders J; Altin, Dag

2014-10-21

The copepod Calanus finmarchicus is a key component of northern Atlantic food webs, linking energy-transfer from phytoplankton to higher trophic levels. We examined the effect of different ocean acidification (OA) scenarios (i.e., ambient, 1080, 2080, and 3080 μatm CO2) over two subsequent generations under limited food availability. Determination of metabolic and feeding rates, and estimations of the scope for growth, suggests that negative effects observed on vital rates (ontogenetic development, somatic growth, fecundity) may be a consequence of energy budget constraints due to higher maintenance costs under high pCO2-environments. A significant delay in development rate among the parental generation animals exposed to 2080 μatm CO2, but not in the following F1 generation under the same conditions, suggests that C. finmarchicus may have adaptive potential to withstand the direct long-term effects of even the more pessimistic future OA scenarios but underlines the importance of transgenerational experiments. The results also indicate that in a more acidic ocean, increased energy expenditure through rising respiration could lower the energy transfer to higher trophic levels and thus hamper the productivity of the northern Atlantic ecosystem.

Experimental investigation of active rib stitch knitted architecture for flow control applications

NASA Astrophysics Data System (ADS)

Abel, Julianna M.; Mane, Poorna; Pascoe, Benjamin; Luntz, Jonathan; Brei, Diann

2010-04-01

Actively manipulating flow characteristics around the wing can enhance the high-lift capability and reduce drag; thereby, increasing fuel economy, improving maneuverability and operation over diverse flight conditions which enables longer, more varied missions. Active knits, a novel class of cellular structural smart material actuator architectures created by continuous, interlocked loops of stranded active material, produce distributed actuation that can actively manipulate the local surface of the aircraft wing to improve flow characteristics. Rib stitch active knits actuate normal to the surface, producing span-wise discrete periodic arrays that can withstand aerodynamic forces while supplying the necessary displacement for flow control. This paper presents a preliminary experimental investigation of the pressuredisplacement actuation performance capabilities of a rib stitch active knit based upon shape memory alloy (SMA) wire. SMA rib stitch prototypes in both individual form and in stacked and nestled architectures were experimentally tested for their quasi-static load-displacement characteristics, verifying the parallel and series relationships of the architectural configurations. The various configurations tested demonstrated the potential of active knits to generate the required level of distributed surface displacements while under aerodynamic level loads for various forms of flow control.

Effect of 25 cycles of launch pad exposure and simulated mission heating on space shuttle reusable surface insulation coated with reaction cured glass

NASA Technical Reports Server (NTRS)

Ransone, P. O.; Morrison, J. D.; Minster, J. E.

1979-01-01

Tiles of space shuttle reusable surface insulation coated with reaction cured glass were subjected to 25 cycles of launch pad exposure and simulated mission heating. The coating could not withstand the environment without cracking. Water absorption after cracking reached as high as 150 weight percent. Exposure of insulation fibers beneath the coating to contaminants dissolved in absorbed water initiated fiber degradation.

PROGRAM ASTEC (ADVANCED SOLAR TURBO ELECTRIC CONCEPT). PART 1. CANDIDATE MATERIALS LABORATORY TESTS

DTIC Science & Technology

A space power system of the type envisioned by the ASTEC program requires the development of a lightweight solar collector of high reflectance...capable of withstanding the space environment for an extended period. A survey of the environment of interest for ASTEC purposes revealed 4 potential...developed by the solar-collector industry for use in the ASTEC program, and to test the effects of space environment on these materials. Of 6 material

Microbiological evaluation of the mobile biological isolator system

NASA Technical Reports Server (NTRS)

Taylor, D. M.; Morelli, F.; Neiderheiser, W.; Tratz, W. M.

1979-01-01

Evaluations on critical components of the mobile biological isolation system were performed. High efficiency particulate air filter efficiency and suit integrity were found to withstand repeated ethylene oxide (ETO) sterilizations. The minimum ETO sterilization time required to inactivate all contaminant organisms was established at four hours. Two days of aerating at 120 F was found to dissipate all harmful ETO residuals from the suit. Donning and doffing procedures were clarified and written specifically for isolation rooms.

What you thought you knew about motion sickness isn't necessarily so

NASA Technical Reports Server (NTRS)

Cowings, P. S.; Malmstrom, F. V.

1984-01-01

Motion sickness symptoms, stimuli, and drug therapy are discussed. Autogenic feedback training (AFT) methods of preventing motion sickness are explained. Research with AFT indicates that participants who had AFT could withstand longer periods of Coriolis acceleration, participants with high or low susceptibility to motion sickness could control their symptoms with AFT, AFT for Coriolis acceleration is transferable to other motion sickness stimuli, and most people can learn AFT, though with varying rates of learning.

Factors associated with the use of violence among urban black adolescents.

PubMed Central

DuRant, R H; Cadenhead, C; Pendergrast, R A; Slavens, G; Linder, C W

1994-01-01

OBJECTIVES. The purpose of this study was to examine social and psychological factors associated with the use and nonuse of violence among Black adolescents living in a community with a high level of violent crime. METHODS. Adolescents (n = 225, 44% male) 11 to 19 years of age living in or around nine housing projects in an urban area were administered an anonymous questionnaire. RESULTS. Self-reported use of violence was associated with exposure to violence and personal victimization, hopelessness, depression, family conflict, previous corporal punishment, purpose in life, self-assessment of the probability of being alive at age 25, and age and was higher among males. CONCLUSIONS. These data support the hypothesis that exposure to violence is associated with adolescents' self-reported use of violence. However, adolescents with a higher sense of purpose in life and less depression were better able to withstand the influence of exposure to violence in the home and in the community. PMID:8154565

An Evolvable Multi-Agent Approach to Space Operations Engineering

NASA Technical Reports Server (NTRS)

Mandutianu, Sanda; Stoica, Adrian

1999-01-01

A complex system of spacecraft and ground tracking stations, as well as a constellation of satellites or spacecraft, has to be able to reliably withstand sudden environment changes, resource fluctuations, dynamic resource configuration, limited communication bandwidth, etc., while maintaining the consistency of the system as a whole. It is not known in advance when a change in the environment might occur or when a particular exchange will happen. A higher degree of sophistication for the communication mechanisms between different parts of the system is required. The actual behavior has to be determined while the system is performing and the course of action can be decided at the individual level. Under such circumstances, the solution will highly benefit from increased on-board and on the ground adaptability and autonomy. An evolvable architecture based on intelligent agents that communicate and cooperate with each other can offer advantages in this direction. This paper presents an architecture of an evolvable agent-based system (software and software/hardware hybrids) as well as some plans for further implementation.

Selection and Application of Sulfide Oxidizing Microorganisms Able to Withstand Thiols in Gas Biodesulfurization Systems.

PubMed

Roman, Pawel; Klok, Johannes B M; Sousa, João A B; Broman, Elias; Dopson, Mark; Van Zessen, Erik; Bijmans, Martijn F M; Sorokin, Dimitry Y; Janssen, Albert J H

2016-12-06

After the first commercial applications of a new biological process for the removal of hydrogen sulfide (H 2 S) from low pressure biogas, the need arose to broaden the operating window to also enable the removal of organosulfur compounds from high pressure sour gases. In this study we have selected microorganisms from a full-scale biodesulfurization system that are capable of withstanding the presence of thiols. This full-scale unit has been in stable operation for more than 10 years. We investigated the microbial community by using high-throughput sequencing of 16S rRNA gene amplicons which showed that methanethiol gave a competitive advantage to bacteria belonging to the genera Thioalkalibacter (Halothiobacillaceae family) and Alkalilimnicola (Ectothiorhosdospiraceae family). The sulfide-oxidizing potential of the acclimatized population was investigated under elevated thiol loading rates (4.5-9.1 mM d -1 ), consisting of a mix of methanethiol, ethanethiol, and propanethiol. With this biomass, it was possible to achieve a stable bioreactor operation at which 80% of the supplied H 2 S (61 mM d -1 ) was biologically oxidized to elemental sulfur. The remainder was chemically produced thiosulfate. Moreover, we found that a conventionally applied method for controlling the oxygen supply to the bioreactor, that is, by maintaining a redox potential set-point value, appeared to be ineffective in the presence of thiols.

Evaluation of slim-edge, multi-guard, and punch-through-protection structures before and after proton irradiation

NASA Astrophysics Data System (ADS)

Mitsui, S.; Unno, Y.; Ikegami, Y.; Takubo, Y.; Terada, S.; Hara, K.; Takahashi, Y.; Jinnouchi, O.; Nagai, R.; Kishida, T.; Yorita, K.; Hanagaki, K.; Takashima, R.; Kamada, S.; Yamamura, K.

2013-01-01

Planar geometry silicon pixel and strip sensors for the high luminosity upgrade of the LHC (HL-LHC) require a high bias voltage of 1000 V in order to withstand a radiation damage caused by particle fluences of 1×1016 1 MeV neq/cm2 and 1×1015 1 MeV neq/cm2 for pixel and strip detectors, respectively. In order to minimize the inactive edge space that can withstand a bias voltage of 1000 V, edge regions susceptible to microdischarge (MD) should be carefully optimized. We fabricated diodes with various edge distances (slim-edge diodes) and with 1-3 multiple guard rings (multi-guard diodes). AC coupling insulators of strip sensors are vulnerable to sudden heavy charge deposition, such as an accidental beam splash, which may destroy the readout AC capacitors. Thus various types of punch-through-protection (PTP) structures were implemented in order to find the most effective structure to protect against heavy charge deposition. These samples were irradiated with 70 MeV protons at fluences of 5×1012 1 MeV neq/cm2-1×1016 1 MeV neq/cm2. Their performances were evaluated before and after irradiation in terms of an onset voltage of the MD, a turn-on voltage of the PTP, and PTP saturation resistance.

The Voltage Distribution Characteristics of a Hybrid Circuit Breaker During High Current Interruption

NASA Astrophysics Data System (ADS)

Cheng, Xian; Duan, Xiongying; Liao, Minfu; Huang, Zhihui; Luo, Yan; Zou, Jiyan

2013-08-01

Hybrid circuit breaker (HCB) technology based on a vacuum interrupter and a SF6 interrupter in series has become a new research direction because of the low-carbon requirements for high voltage switches. The vacuum interrupter has an excellent ability to deal with the steep rising part of the transient recovery voltage (TRV), while the SF6 interrupter can withstand the peak part of the voltage easily. An HCB can take advantage of the interrupters in the current interruption process. In this study, an HCB model based on the vacuum ion diffusion equations, ion density equation, and modified Cassie-Mayr arc equation is explored. A simulation platform is constructed by using a set of software called the alternative transient program (ATP). An HCB prototype is also designed, and the short circuit current is interrupted by the HCB under different action sequences of contacts. The voltage distribution of the HCB is analyzed through simulations and tests. The results demonstrate that if the vacuum interrupter withstands the initial TRV and interrupts the post-arc current first, then the recovery speed of the dielectric strength of the SF6 interrupter will be fast. The voltage distribution between two interrupters is determined by their post-arc resistance, which happens after current-zero, and subsequently, it is determined by the capacitive impedance after the post-arc current decays to zero.

Heat Flux Sensor

NASA Technical Reports Server (NTRS)

1994-01-01

A heat flux microsensor developed under a NASP Small Business Innovation Research (SBIR) has a wide range of potential commercial applications. Vatell Corporation originally designed microsensors for use in very high temperatures. The company then used the technology to develop heat flux sensors to measure the rate of heat energy flowing in and out of a surface as well as readings on the surface temperature. Additional major advantages include response to heat flux in less than 10 microseconds and the ability to withstand temperatures up to 1,200 degrees centigrade. Commercial applications are used in high speed aerodynamics, supersonic combustion, blade cooling, and mass flow measurements, etc.

Stable Boron Nitride Interphases for Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Morscher, Gregory N.

1999-01-01

Ceramic matrix composites (CMC's) require strong fibers for good toughness and weak interphases so that cracks which are formed in the matrix debond and deflect around the fibers. If the fibers are strongly bonded to the matrix, CMC's behave like monolithic ceramics (e.g., a ceramic coffee cup), and when subjected to mechanical loads that induce cracking, such CMC's fail catastrophically. Since CMC's are being developed for high temperature corrosive environments such as the combustor liner for advanced High Speed Civil Transport aircraft, the interphases need to be able to withstand the environment when the matrix cracks.

Fusion power: a challenge for materials science.

PubMed

Duffy, D M

2010-07-28

The selection and design of materials that will withstand the extreme conditions of a fusion power plant has been described as one of the greatest materials science challenges in history. The high particle flux, high thermal load, thermal mechanical stress and the production of transmutation elements combine to produce a uniquely hostile environment. In this paper, the materials favoured for the diverse roles in a fusion power plant are discussed, along with the experimental and modelling techniques that are used to advance the understanding of radiation damage in materials. Areas where further research is necessary are highlighted.

High performing actuation system for use with a louver array for satellite thermal control. [design and performance tests on prototype Bourdon spiral configuration

NASA Technical Reports Server (NTRS)

Reusser, P. U.; Coebergh, J. A. F.

1973-01-01

A high performing actuation system has been developed to drive one pair or a set of 9 pairs of louver blades. The system uses a Bourdon spiral as the driving member. The response time of the liquid expansion of the spiral system is in the order of three seconds. Besides performance tests, qualification tests have been carried out on a prototype system, demonstrating that the actuation system withstands normal launching conditions; projected operating life of 7 years with more than 7000 cycles can be expected.

High-energy synchrotron x-ray techniques for studying irradiated materials

DOE PAGES

Park, Jun-Sang; Zhang, Xuan; Sharma, Hemant; ...

2015-03-20

High performance materials that can withstand radiation, heat, multiaxial stresses, and corrosive environment are necessary for the deployment of advanced nuclear energy systems. Nondestructive in situ experimental techniques utilizing high energy x-rays from synchrotron sources can be an attractive set of tools for engineers and scientists to investigate the structure–processing–property relationship systematically at smaller length scales and help build better material models. In this paper, two unique and interconnected experimental techniques, namely, simultaneous small-angle/wide-angle x-ray scattering (SAXS/WAXS) and far-field high-energy diffraction microscopy (FF-HEDM) are presented. Finally, the changes in material state as Fe-based alloys are heated to high temperatures ormore » subject to irradiation are examined using these techniques.« less

Low level tumor necrosis factor-alpha protects cardiomyocytes against high level tumor necrosis factor-alpha: brief insight into a beneficial paradox.

PubMed

Cacciapaglia, Fabio; Salvatorelli, Emanuela; Minotti, Giorgio; Afeltra, Antonella; Menna, Pierantonio

2014-12-01

Whether tumor necrosis factor-alpha (TNFα) caused beneficial or detrimental cardiovascular effects remains poorly defined. Anti-TNFα agents improved cardiac end points in chronic rheumatic diseases characterized by progressive deterioration of cardiac function. In contrast, anti-TNFα agents did not always improve but actually worsened cardiac function in non-rheumatic patients with heart failure (HF), in spite of that HF usually accompanies with high circulating levels of TNFα. To shed light on these mixed findings, we characterized the effects of TNFα in H9c2 cardiomyocytes. Cells were incubated for 24 h with increasing concentrations of TNFα, hydrogen peroxide, aminotriazole, or etoposide. Posttreatment cell viability was assessed by antimycin A-inhibitable reduction of 3-(4,dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, and the IC50 value of each test compound was defined. H9c2 cells were also preconditioned with a low non-toxic concentration of TNFα and then re-challenged with increasing concentrations of TNFα and other stressor agents. In re-challenge experiments, all of the IC50 values increased significantly, with the IC50 value of TNFα increasing approximately 16-fold. TNFα preconditioning increased cardiomyocytes shedding of the external portion of transmembrane type 1 and type 2 TNFα receptors [(soluble TNFα receptors (sTNFR)]. Levels of survival-oriented soluble TNFR2 (sTNFR2) always exceeded those of death-oriented sTNFR1. When exposed to TNFα at its IC50 value, preconditioned cardiomyocytes showed an increased release of sTNFR2 but not sTNFR1. These results denoted that preconditioning by "low TNFα" helped cardiomyocyte to withstand toxicity from "high TNFα" or other agents. These results also suggested that beneficial or detrimental effects of anti-TNFα agents might well depend on whether these agents spared or intercepted discrete amounts of TNFα that preconditioned cardiomyocytes and made them more resistant to high concentrations of TNFα.

Explosive and pyrotechnic aging demonstration

NASA Technical Reports Server (NTRS)

Rouch, L. L., Jr.; Maycock, J. N.

1976-01-01

The survivability was experimentally verified of fine selected explosive and pyrotechnic propellant materials when subjected to sterilization, and prolonged exposure to space environments. This verification included thermal characterization, sterilization heat cycling, sublimation measurements, isothermal decomposition measurements, and accelerated aging at a preselected elevated temperature. Temperatures chosen for sublimation and isothermal decomposition measurements were those in which the decomposition processess occurring would be the same as those taking place in real-time aging. The elevated temperature selected (84 C) for accelerated aging was based upon the parameters calculated from the kinetic data obtained in the isothermal measurement tests and was such that one month of accelerated aging in the laboratory approximated one year of real-time aging at 66 C. Results indicate that HNS-IIA, pure PbN6, KDNBF, and Zr/KC10 are capable of withstanding sterilization. The accelerated aging tests indicated that unsterilized HNS-IIA and Zr/KC104 can withstand the 10 year, elevated temperature exposure, pure PbN6 and KDNBF exhibit small weight losses (less than 2 percent) and B/KC104 exhibits significant changes in its thermal characteristics. Accelerated aging tests after sterilization indicated that only HNS-IIA exhibited high stability.

Development Testing and Subsequent Failure Investigation of a Spring Strut Mechanism

NASA Technical Reports Server (NTRS)

Dervan, Jared; Robertson, Brandan; Staab, Lucas; Culberson, Michael; Pellicciotti, Joseph

2014-01-01

The NASA Engineering and Safety Center (NESC) and Lockheed Martin (LM) performed random vibration testing on a single spring strut development unit to assess its ability to withstand qualification level random vibration environments. Failure of the strut while exposed to random vibration resulted in a follow-on failure investigation, design changes, and additional development tests. This paper focuses on the results of the failure investigations referenced in detail in the NESC final report [1] including identified lessons learned to aid in future design iterations of the spring strut and to help other mechanism developers avoid similar pitfalls.

Development Testing and Subsequent Failure Investigation of a Spring Strut Mechanism

NASA Technical Reports Server (NTRS)

Dervan, Jared; Robertson, Brandon; Staab, Lucas; Culberson, Michael; Pellicciotti, Joseph

2014-01-01

The NASA Engineering and Safety Center (NESC) and Lockheed Martin (LM) performed random vibration testing on a single spring strut development unit to assess its ability to withstand qualification level random vibration environments. Failure of the strut while exposed to random vibration resulted in a follow-on failure investigation, design changes, and additional development tests. This paper focuses on the results of the failure investigations referenced in detail in the NESC final report including identified lessons learned to aid in future design iterations of the spring strut and to help other mechanism developers avoid similar pitfalls.

Analysis on Flexural Strength of A36 Mild Steel by Design of Experiment (DOE)

NASA Astrophysics Data System (ADS)

Nurulhuda, A.; Hafizzal, Y.; Izzuddin, MZM; Sulawati, MRN; Rafidah, A.; Suhaila, Y.; Fauziah, AR

2017-08-01

Nowadays demand for high quality and reliable components and materials are increasing so flexural tests have become vital test method in both the research and manufacturing process and development to explain in details about the material’s ability to withstand deformation under load. Recently, there are lack research studies on the effect of thickness, welding type and joint design on the flexural condition by DOE approach method. Therefore, this research will come out with the flexural strength of mild steel since it is not well documented. By using Design of Experiment (DOE), a full factorial design with two replications has been used to study the effects of important parameters which are welding type, thickness and joint design. The measurement of output response is identified as flexural strength value. Randomize experiments was conducted based on table generated via Minitab software. A normal probability test was carried out using Anderson Darling Test and show that the P-value is <0.005. Thus, the data is not normal since there is significance different between the actual data with the ideal data. Referring to the ANOVA, only factor joint design is significant since the P-value is less than 0.05. From the main plot and interaction plot, the recommended setting for each of parameters were suggested as high level for welding type, high level for thickness and low level for joint design. The prediction model was developed thru regression in order to measure effect of output response for any changes on parameters setting. In the future, the experiments can be enhanced using Taguchi methods in order to do verification of result.

Design and Testing of a Solid-Liquid Interface Monitor for High-Level Waste Tanks

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

McDaniel, D.; Awwad, A.; Roelant, D.

2008-07-01

A high-level waste (HLW) monitor has been designed, fabricated and tested at full-scale for deployment inside a Hanford tank. The Solid-Liquid Interface Monitor (SLIM) integrates a commercial sonar system with a mechanical deployment system for deploying into an underground waste tank. The system has undergone several design modifications based upon changing requirements at Hanford. We will present the various designs of the monitor from first to last and will present performance data from the various prototype systems. We will also present modeling of stresses in the enclosure under 85 mph wind loading. The system must be able to function atmore » winds up to 15 mph and must withstand a maximum loading of 85 mph. There will be several examples presented of engineering tradeoffs made as FIU analyzed new requirements and modified the design to accommodate. We will present our current plans for installing into the Cold Test Facility at Hanford and into a double-shelled tank at Hanford. Finally, we will present our vision for how this technology can be used at Hanford and Savannah River Site to improve the filling and emptying of high-level waste tanks. In conclusion: 1. The manually operated first-generation SLIM is a viable option on tanks where personnel are allowed to work on top of the tank. 2. The remote controlled second-generation SLIM can be utilized on tanks where personnel access is limited. 3. The totally enclosed fourth-generation SLIM, when the design is finalized, can be used when the possibility exists for wind dispersion of any HLW that maybe on the system. 4. The profiling sonar can be used effectively for real-time monitoring of the solid-liquid interface over a large area. (authors)« less

Room-Temperature Deformation and Martensitic Transformation of Two Co-Cr-Based Alloys

NASA Astrophysics Data System (ADS)

Cai, S.; Schaffer, J. E.; Huang, D.; Gao, J.; Ren, Y.

2018-05-01

Deformation of two Co-Cr alloys was studied by in situ synchrotron X-ray diffraction. Both alloys show stress-induced martensite transformation, which is affected by phase stabilities and transformation strains. Crystal structure of WC in Co-20Cr-15W-10Ni is identified. Compared with other phases present, it is elastically isotropic, exhibits high strength, and can elastically withstand strains exceeding 1 pct. Texture change during phase transformation is explained based on the crystal orientation relationship between γ- and ɛ-phases.

Edge attachment study for fire-resistant canopies

NASA Technical Reports Server (NTRS)

Wintermute, G. E.

1982-01-01

Twenty-two resin systems were evaluated in laminate form for possible use as edge attachment material for fire-resistant canopies. The evaluation uncovered an unexpected development when the laminates were subjected to an intense flame: (1) the high-heat-resistant materials could withstand the flame test quite well, but experienced rapid heat transfer through the test specimen; (2) the laminates which exhibited a low rate of heat transfer were materials which lost strength rapidly in the presence of the flame by decomposition, delamination, and blistering.

An intelligent inspection and survey robot. Volume 2

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

NONE

1995-12-15

Radioactive materials make up a significant part of the hazardous-material inventory of the Department of Energy. Much of the radioactive material will be inspected or handled by robotic systems that contain electronic circuits that may be damaged by gamma radiation and other particles emitted from radioactive material. This report examines several scenarios, the damage that may be inflicted, and methods that may be used to protect radiation-hardened robot control systems. Commercial sources of components and microcomputers that can withstand high radiation exposure are identified.

The Effects of Warhead-Induced Damage on the Aeroelastic Characteristics of Lifting Surfaces. Volume I. Aeroelastic Effects.

DTIC Science & Technology

1980-07-01

Arnold. Some further insight into the problem is obtained here, however, when it is demonstrated that highly optimized structural designs may...aircraft of this type are normally designed to withstand loads up to 1.5 times the maximum limit load (load factor 8.0 to 8.67), the structure should...on the wing, for example, give rise to concentrated drag and chordwise loadings as does the recoil from firing wing mounted gun systems . The drag on

Mechanical beam isolator for high-power laser systems

DOEpatents

Post, Richard F.; Vann, Charles S.

1998-01-01

A mechanical beam isolator uses rod-shaped elements having a Gaussian configuration to interrupt the path of a beam of photons or particles when the time-scale of the needed interruption is of the order of a microsecond or less. One or more of these rods is mounted transversely to, and penetrates through, a rotating shaft supported by bearings. Owing to the Gaussian geometry of the rods, they are able to withstand much higher rotation speeds, without tensile failure, than rods having any other geometrical shape.

Annual Report to the Strategic Defense Initiative Organization on the Free-Electron Laser Driven by the NIST CW Microtron

DTIC Science & Technology

1986-05-05

design of the injector for the method selected was completed. A study on the problem of mirror damage has been completed, and commercial suppliers of... mirrors that can withstand the high intracavity power of the FEL have been identified. The design of the room in which the FEL is located has been...Appendices ............ ............................. .25 A. Design Note 10 - Mirror Damage B. Design Note 11 - Wiggler Field Errors C. Design Note 12

Room-Temperature Deformation and Martensitic Transformation of Two Co-Cr-Based Alloys

NASA Astrophysics Data System (ADS)

Cai, S.; Schaffer, J. E.; Huang, D.; Gao, J.; Ren, Y.

2018-07-01

Deformation of two Co-Cr alloys was studied by in situ synchrotron X-ray diffraction. Both alloys show stress-induced martensite transformation, which is affected by phase stabilities and transformation strains. Crystal structure of WC in Co-20Cr-15W-10Ni is identified. Compared with other phases present, it is elastically isotropic, exhibits high strength, and can elastically withstand strains exceeding 1 pct. Texture change during phase transformation is explained based on the crystal orientation relationship between γ- and ɛ-phases.

VHF (Very High Frequency)-AM Communications Equipment Selection and Installation Practices for Helicopters.

DTIC Science & Technology

1985-09-01

available for VHF ground stations. It examines In detail the options available in the avionics market place, and the problems associated with comparing...Appendix A presents the results of a survey of manufacturer’s specifications for 49 different models of airborne VHF communicatons avionics. A review...aimed primarily at the ’rbine aircraft market ). They are much stronger than "cat’s whisker" types and are capable of withstanding the drag and g

A Methodology for the Evaluation of Alternative Offshore Container Discharge Systems.

DTIC Science & Technology

1982-04-01

effects of sea induced motions . These in- clude the use of larger capacity cranes to withstand the extra loads , structural modifications or add-on...relative motion between ships at sea. (39,40) Solutions include: a) Accelerometers mounted in the load block, crane boom tip, and on the deck of the...between the vertical motion of the crane boom and the load has the char- I acteristics of a high pass filter. That is, low frequency excursions of

Potential of Aerostats for the Recovery of Disabled Main Battle Tanks and Other Heavy Military Vehicles and Equipment

DTIC Science & Technology

2007-08-01

designs and operates numerous passenger airships. The envelope structure consists of a laminated fabric envelope. This envelope is a large bag...Layered Aerostat Fabric This multi-layered laminate is designed to withstand the sun’s UV rays, acid rain and other environmental concerns. It is...a tough laminate , which inhibits gas loss while providing a high strength-to-weight ratio. The CL75 envelope used a laminate material woven with

Heavily loaded joints for assembling aerobrake support trusses

NASA Technical Reports Server (NTRS)

Bandel, Hannskarl; Olsson, Nils; Levintov, Boris

1990-01-01

The major emphasis was to develop erectable joints for large aerobrake support trusses. The truss joints must be able to withstand the large forces experienced by the truss during the aero-pass, as well as be easily assembled and disassembled on orbit by astronauts or robots. Other important design considerations include; strength, stiffness, and allowable error in strut length. Six mechanical joint designs, as well as a seventh joint design, where a high strength epoxy is injected to make the connection rigid, are presented.

Hydraulic lift and tolerance to salinity of semiarid species: consequences for species interactions.

PubMed

Armas, Cristina; Padilla, Francisco M; Pugnaire, Francisco I; Jackson, Robert B

2010-01-01

The different abilities of plant species to use ephemeral or permanent water sources strongly affect physiological performance and species coexistence in water-limited ecosystems. In addition to withstanding drought, plants in coastal habitats often have to withstand highly saline soils, an additional ecological stress. Here we tested whether observed competitive abilities and C-water relations of two interacting shrub species from an arid coastal system were more related to differences in root architecture or salinity tolerance. We explored water sources of interacting Juniperus phoenicea Guss. and Pistacia lentiscus L. plants by conducting physiology measurements, including water relations, CO2 exchange, photochemical efficiency, sap osmolality, and water and C isotopes. We also conducted parallel soil analyses that included electrical conductivity, humidity, and water isotopes. During drought, Pistacia shrubs relied primarily on permanent salty groundwater, while isolated Juniperus plants took up the scarce and relatively fresh water stored in upper soil layers. As drought progressed further, the physiological activity of Juniperus plants nearly stopped while Pistacia plants were only slightly affected. Juniperus plants growing with Pistacia had stem-water isotopes that matched Pistacia, unlike values for isolated Juniperus plants. This result suggests that Pistacia shrubs supplied water to nearby Juniperus plants through hydraulic lift. This lifted water, however, did not appear to benefit Juniperus plants, as their physiological performance with co-occurring Pistacia plants was poor, including lower water potentials and rates of photosynthesis than isolated plants. Juniperus was more salt sensitive than Pistacia, which withstood salinity levels similar to that of groundwater. Overall, the different abilities of the two species to use salty water appear to drive the outcome of their interaction, resulting in asymmetric competition where Juniperus is negatively affected by Pistacia. Salt also seems to mediate the interaction between the two species, negating the potential positive effects of an additional water source via hydraulic lift.

KENNEDY SPACE CENTER, FLA. - Jim Landy, NDE specialist with United Space Alliance (USA), prepares equipment to examine a Reinforced Carbon Carbon panel using flash thermography. A relatively new procedure at KSC, thermography uses high intensity light to heat areas of the panels. The panels are then immediately scanned with an infrared camera. As the panels cool, any internal flaws are revealed. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters. They have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry. The panels will be installed on the orbiter Discovery, designated for the first Return to Flight mission, STS-114.

NASA Image and Video Library

2004-03-10

KENNEDY SPACE CENTER, FLA. - Jim Landy, NDE specialist with United Space Alliance (USA), prepares equipment to examine a Reinforced Carbon Carbon panel using flash thermography. A relatively new procedure at KSC, thermography uses high intensity light to heat areas of the panels. The panels are then immediately scanned with an infrared camera. As the panels cool, any internal flaws are revealed. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters. They have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry. The panels will be installed on the orbiter Discovery, designated for the first Return to Flight mission, STS-114.

KENNEDY SPACE CENTER, FLA. - Jim Landy, NDE specialist with USA, points to an area of a Reinforced Carbon Carbon panel just examined using flash thermography. A relatively new procedure at KSC, thermography uses high intensity light to heat areas of the panels. The panels are then immediately scanned with an infrared camera. As the panels cool, any internal flaws are revealed. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters. They have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry. The panels will be installed on the orbiter Discovery, designated for the first Return to Flight mission, STS-114.

NASA Image and Video Library

2004-03-10

KENNEDY SPACE CENTER, FLA. - Jim Landy, NDE specialist with USA, points to an area of a Reinforced Carbon Carbon panel just examined using flash thermography. A relatively new procedure at KSC, thermography uses high intensity light to heat areas of the panels. The panels are then immediately scanned with an infrared camera. As the panels cool, any internal flaws are revealed. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters. They have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry. The panels will be installed on the orbiter Discovery, designated for the first Return to Flight mission, STS-114.

KENNEDY SPACE CENTER, FLA. - Jim Landy, NDE specialist with United Space Alliance (USA), examines a Reinforced Carbon Carbon panel using flash thermography. A relatively new procedure at KSC, thermography uses high intensity light to heat areas of the panels. The panels are then immediately scanned with an infrared camera. As the panels cool, any internal flaws are revealed. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters. They have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry. The panels will be installed on the orbiter Discovery, designated for the first Return to Flight mission, STS-114.

NASA Image and Video Library

2004-03-10

KENNEDY SPACE CENTER, FLA. - Jim Landy, NDE specialist with United Space Alliance (USA), examines a Reinforced Carbon Carbon panel using flash thermography. A relatively new procedure at KSC, thermography uses high intensity light to heat areas of the panels. The panels are then immediately scanned with an infrared camera. As the panels cool, any internal flaws are revealed. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters. They have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry. The panels will be installed on the orbiter Discovery, designated for the first Return to Flight mission, STS-114.

KENNEDY SPACE CENTER, FLA. - Jim Landy, NDE specialist with United Space Alliance, sets up equipment to examine a Reinforced Carbon Carbon panel using flash thermography. A relatively new procedure at KSC, thermography uses high intensity light to heat areas of the panels. The panels are then immediately scanned with an infrared camera. As the panels cool, any internal flaws are revealed. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters. They have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry. The panels will be installed on the orbiter Discovery, designated for the first Return to Flight mission, STS-114.

NASA Image and Video Library

2004-03-10

KENNEDY SPACE CENTER, FLA. - Jim Landy, NDE specialist with United Space Alliance, sets up equipment to examine a Reinforced Carbon Carbon panel using flash thermography. A relatively new procedure at KSC, thermography uses high intensity light to heat areas of the panels. The panels are then immediately scanned with an infrared camera. As the panels cool, any internal flaws are revealed. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters. They have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry. The panels will be installed on the orbiter Discovery, designated for the first Return to Flight mission, STS-114.

Advanced High-Temperature Flexible TPS for Inflatable Aerodynamic Decelerators

NASA Technical Reports Server (NTRS)

DelCorso, Joseph A.; Cheatwood, F. McNeil; Bruce, Walter E., III; Hughes, Stephen J.; Calomino, Anthony M.

2011-01-01

Typical entry vehicle aeroshells are limited in size by the launch vehicle shroud. Inflatable aerodynamic decelerators allow larger aeroshell diameters for entry vehicles because they are not constrained to the launch vehicle shroud diameter. During launch, the hypersonic inflatable aerodynamic decelerator (HIAD) is packed in a stowed configuration. Prior to atmospheric entry, the HIAD is deployed to produce a drag device many times larger than the launch shroud diameter. The large surface area of the inflatable aeroshell provides deceleration of high-mass entry vehicles at relatively low ballistic coefficients. Even for these low ballistic coefficients there is still appreciable heating, requiring the HIAD to employ a thermal protection system (TPS). This TPS must be capable of surviving the heat pulse, and the rigors of fabrication handling, high density packing, deployment, and aerodynamic loading. This paper provides a comprehensive overview of flexible TPS tests and results, conducted over the last three years. This paper also includes an overview of each test facility, the general approach for testing flexible TPS, the thermal analysis methodology and results, and a comparison with 8-foot High Temperature Tunnel, Laser-Hardened Materials Evaluation Laboratory, and Panel Test Facility test data. Results are presented for a baseline TPS layup that can withstand a 20 W/cm2 heat flux, silicon carbide (SiC) based TPS layup, and polyimide insulator TPS layup. Recent work has focused on developing material layups expected to survive heat flux loads up to 50 W/cm2 (which is adequate for many potential applications), future work will consider concepts capable of withstanding more than 100 W/cm2 incident radiant heat flux. This paper provides an overview of the experimental setup, material layup configurations, facility conditions, and planned future flexible TPS activities.

Flywheel containment technology assessment

NASA Astrophysics Data System (ADS)

Coppa, A. P.; Zweben, C. H.; Mirandy, L.

1980-07-01

The important effect of containment weight on the density of a flywheel was examined for a selection of flywheel designs incorporating metallic and composite construction as contained by steel housings. Three different flywheel constructions are presented, namely laminated rotor, shaped disk, and multirim. Materials are steel for the first two types and E glass, S glass and Kevlar composites for the third type. All of the flywheels were comparable in that their stress levels were based on long term high cycle operation. All of the specific energy values were penalized heavily by the containment weight, the least being the laminated rotor (-29 percent) and the greatest being the shaped disk (-72 percent). The penalties for the multirim designs are -45 percent (E glass), -55 percent (S glass), and -60 percent (Kevlar). The low penalty of the laminated steel rotor was due to the fact that the containment weight was based on withstanding the rupture of only one of the constituent disks. The high penalty of the shaped steel disk, on the other hand, reflects the severe containment action that resulted from its bursting into large, hard, and axially narrow fragments. The intermediate but nevertheless substantial containment penalty of the multidrum composite rotors resulted from their relatively mild containment behavior.

Dominance of Saccharomyces cerevisiae in alcoholic fermentation processes: role of physiological fitness and microbial interactions.

PubMed

Albergaria, Helena; Arneborg, Nils

2016-03-01

Winemaking, brewing and baking are some of the oldest biotechnological processes. In all of them, alcoholic fermentation is the main biotransformation and Saccharomyces cerevisiae the primary microorganism. Although a wide variety of microbial species may participate in alcoholic fermentation and contribute to the sensory properties of end-products, the yeast S. cerevisiae invariably dominates the final stages of fermentation. The ability of S. cerevisiae to outcompete other microbial species during alcoholic fermentation processes, such as winemaking, has traditionally been ascribed to its high fermentative power and capacity to withstand the harsh environmental conditions, i.e. high levels of ethanol and organic acids, low pH values, scarce oxygen availability and depletion of certain nutrients. However, in recent years, several studies have raised evidence that S. cerevisiae, beyond its remarkable fitness for alcoholic fermentation, also uses defensive strategies mediated by different mechanisms, such as cell-to-cell contact and secretion of antimicrobial peptides, to combat other microorganisms. In this paper, we review the main physiological features underlying the special aptitude of S. cerevisiae for alcoholic fermentation and discuss the role of microbial interactions in its dominance during alcoholic fermentation, as well as its relevance for winemaking.

A Sub-Orbital Platform for Flight Tests of Small Space Capsules

NASA Astrophysics Data System (ADS)

Pereira, P. Moraes A. L., Jr.; Silva, C. R.; Villas Bôas, D. J.; Corrêa, F., Jr.; Miyoshi, J. H.; Loures da Costa, L. E.

2002-01-01

In the development of a small recoverable space capsule, flight tests using sub-orbital rockets are considered. For this test series, a platform for aerodynamic and thermal measurements as also for qualification tests of onboard sub-systems and equipment was specified and is actually under development. This platform, known as SARA Suborbital, is specified to withstand a sub-orbital flight with the high performance sounding rocket VS40 and to be recovered at the sea. To perform the testing program, a flight trajectory with adequate aeroballistic parameters, as for instance high velocities in dense atmosphere and average re-entry velocity, is considered. The testing program includes measurements of aerodynamic pressures and thermal characteristics, three- axis acceleration, acoustic pressure level inside the platform and vibration environment. Beside this, tests to characterise the performance of the data acquisition and transmission system, the micro-gravity environment and to qualify the recovery system will be carried out. During the return flight, the dynamics of parachutes deployment and platform water impact, as also rescue procedures will also be observed. The present article shows the concept of the platform, describes in detail the experiments, and concludes with a discussion on the flight trajectory and recovery procedure.

Microfluidic Flame Barrier

NASA Technical Reports Server (NTRS)

Mungas, Gregory S. (Inventor); Fisher, David J. (Inventor); Mungas, Christopher (Inventor)

2013-01-01

Propellants flow through specialized mechanical hardware that is designed for effective and safe ignition and sustained combustion of the propellants. By integrating a micro-fluidic porous media element between a propellant feed source and the combustion chamber, an effective and reliable propellant injector head may be implemented that is capable of withstanding transient combustion and detonation waves that commonly occur during an ignition event. The micro-fluidic porous media element is of specified porosity or porosity gradient selected to be appropriate for a given propellant. Additionally the propellant injector head design integrates a spark ignition mechanism that withstands extremely hot running conditions without noticeable spark mechanism degradation.

Micro Penning Trap for Continuous Magnetic Field Monitoring in High Radiation Environments

NASA Astrophysics Data System (ADS)

Latorre, Javiera; Bollen, Georg; Gulyuz, Kerim; Ringle, Ryan; Bado, Philippe; Dugan, Mark; Lebit Team; Translume Collaboration

2016-09-01

As new facilities for rare isotope beams, like FRIB at MSU, are constructed, there is a need for new instrumentation to monitor magnetic fields in beam magnets that can withstand the higher radiation level. Currently NMR probes, the instruments used extensively to monitor magnetic fields, do not have a long lifespans in radiation-high environments. Therefore, a radiation-hard replacement is needed. We propose to use Penning trap mass spectrometry techniques to make high precision magnetic field measurements. Our Penning microtrap will be radiation resistant as all of the vital electronics will be at a safe distance from the radiation. The trap itself is made from materials not subject to radiation damage. Penning trap mass spectrometers can determine the magnetic field by measuring the cyclotron frequency of an ion with a known mass and charge. This principle is used on the Low Energy Beam Ion Trap (LEBIT) minitrap at NSCL which is the foundation for the microtrap. We have partnered with Translume, who specialize in glass micro-fabrication, to develop a microtrap in fused-silica glass. A microtrap is finished and ready for testing at NSCL with all of the electronic and hardware components setup. DOE Phase II SBIR Award No. DE-SC0011313, NSF Award Number 1062410 REU in Physics, NSF under Grant No. PHY-1102511.

Ground/bonding for Large Space System Technology (LSST). [of metallic and nonmetallic structures

NASA Technical Reports Server (NTRS)

Dunbar, W. G.

1980-01-01

The influence of the environment and extravehicular activity remote assembly operations on the grounding and bonding of metallic and nonmetallic structures is discussed. Grounding and bonding philosophy is outlined for the electrical systems and electronic compartments which contain high voltage, high power electrical and electronic equipment. The influence of plasma and particulate on the system was analyzed and the effects of static buildup on the spacecraft electrical system discussed. Conceptual grounding bonding designs are assessed for capability to withstand high current arcs to ground from a high voltage conductor and electromagnetic interference. Also shown were the extravehicular activities required of the space station and or supply spacecraft crew members to join and inspect the ground system using manual on remote assembly construction.

Cables and connectors for Large Space System Technology (LSST)

NASA Technical Reports Server (NTRS)

Dunbar, W. G.

1980-01-01

The effect of the environment and extravehicular activity/remote assembly operations on the cables and connectors for spacecraft with metallic and/or nonmetallic structures was examined. Cable and connector philosophy was outlined for the electrical systems and electronic compartments which contain high-voltage, high-power electrical and electronic equipment. The influence of plasma and particulates on the system is analyzed and the effect of static buildup on the spacecraft electrical system discussed. Conceptual cable and connector designs are assessed for capability to withstand high current and high voltage without danger of arcs and electromagnetic interference. The extravehicular activites required of the space station and/or supply spacecraft crew members to join and inspect the electrical system, using manual or remote assembly construction are also considered.

Design requirements for plasma facing materials in ITER

NASA Astrophysics Data System (ADS)

Matera, R.; Federici, G.; ITER Joint Central Team

1996-10-01

After the official approval of the Interim Design Report, the ITER project enters the final phase of the EDA. With the definition of the design requirements of the high heat flux components, the structural and armor materials' working domain is better specified, allowing to focus the R & D program on the most critical issues and to orient the design of divertor and first wall components towards those concepts which potentially have a better chance to withstand normal and off-normal operating conditions. Among the latter, slow, high-power, high recycling transient are at present driving the design of high heat flux components. Examples of possible design solution under experimental validation in the R & D program are presented and discussed in this paper.

Ground/bonding for Large Space System Technology (LSST)

NASA Astrophysics Data System (ADS)

Dunbar, W. G.

1980-04-01

The influence of the environment and extravehicular activity remote assembly operations on the grounding and bonding of metallic and nonmetallic structures is discussed. Grounding and bonding philosophy is outlined for the electrical systems and electronic compartments which contain high voltage, high power electrical and electronic equipment. The influence of plasma and particulate on the system was analyzed and the effects of static buildup on the spacecraft electrical system discussed. Conceptual grounding bonding designs are assessed for capability to withstand high current arcs to ground from a high voltage conductor and electromagnetic interference. Also shown were the extravehicular activities required of the space station and or supply spacecraft crew members to join and inspect the ground system using manual on remote assembly construction.

How the charge-neutrality level of interface states controls energy level alignment in cathode contacts of organic bulk-heterojunction solar cells.

PubMed

Guerrero, Antonio; Marchesi, Luís F; Boix, Pablo P; Ruiz-Raga, Sonia; Ripolles-Sanchis, Teresa; Garcia-Belmonte, Germà; Bisquert, Juan

2012-04-24

Electronic equilibration at the metal-organic interface, leading to equalization of the Fermi levels, is a key process in organic optoelectronic devices. How the energy levels are set across the interface determines carrier extraction at the contact and also limits the achievable open-circuit voltage under illumination. Here, we report an extensive investigation of the cathode energy equilibration of organic bulk-heterojunction solar cells. We show that the potential to balance the mismatch between the cathode metal and the organic layer Fermi levels is divided into two contributions: spatially extended band bending in the organic bulk and voltage drop at the interface dipole layer caused by a net charge transfer. We scan the operation of the cathode under a varied set of conditions, using metals of different work functions in the range of ∼2 eV, different fullerene acceptors, and several cathode interlayers. The measurements allow us to locate the charge-neutrality level within the interface density of sates and calculate the corresponding dipole layer strength. The dipole layer withstands a large part of the total Fermi level mismatch when the polymer:fullerene blend ratio approaches ∼1:1, producing the practical alignment between the metal Fermi level and the charge-neutrality level. Origin of the interface states is linked with fullerene reduced molecules covering the metal contact. The dipole contribution, and consequently the band bending, is highly sensitive to the nature and amount of fullerene molecules forming the interface density of states. Our analysis provides a detailed picture of the evolution of the potentials in the bulk and the interface of the solar cell when forward voltage is applied or when photogeneration takes place.

Ocean acidification effects on calcification in Caribbean scleractinian coral exposed to elevated pCO2: a potential for acclimation

NASA Astrophysics Data System (ADS)

Hankins, C.

2016-02-01

Ocean acidification (OA) is projected to increase the acidity of coral reef habitats 2-3 times that of present day pCO2 levels. Many studies have shown the adverse effects on scleractinian calcification when exposed to elevated pCO2 levels, however, no such effects were seen in this study whereby corals were exposed for three months to elevated pCO2 levels. In this study, all corals were kept in culture for one year prior to being used in experimental trials. Data from culture systems shows coral experience a range of pCO2 from 300-600 µatm over the course of a day. This range is attributed to respiration and photosynthesis which also naturally occurs in a reef habitat. Montastrea cavernosa, Orbicella faveolata, and Pseudodiploria clivosa were exposed to their ambient culture conditions (control) or to elevated pCO2 levels of 1000 µatm (IPCC A1F1 scenario). By combining photographic analysis of live tissue area or exposed skeleton with the buoyant weight technique, an area density of each coral fragment was obtained to infer rates of calcification or erosion of skeleton. After three months of experimental exposure, preliminary results suggest that there is no significant difference in calcification or erosion in any of the species tested. Acclimation in the elevated pCO2 culture environment may have conditioned the coral to better withstand high pCO2 levels. Long acclimation periods of coral to near term future pCO2 levels may more accurately predict calcification responses in corals of the future.

Influence of tools geometry and processing conditions on behavior of a difficult-to-work Al-Mg alloy during equal channel angular pressing

NASA Astrophysics Data System (ADS)

Comǎneci, Radu Ioachim; Nedelcu, Dumitru; Bujoreanu, Leandru Gheorghe

2017-10-01

Equal channel angular pressing (ECAP) is a well-established method for grain refinement in metallic materials by large shear plastic deformation, being the most promising and effective severe plastic deformation (SPD) technique. ECAP is a discontinuous process, so the billet removal implies a new development of the procedure: the new sample pushes out the previous sample. In resuming the process the head and the tail ends of the work piece which becomes strongly distorted and receiving different amount of strain have to be removed. Due to the path difference in material flow between upper and lower region of the outlet channel, a non-uniform strain and stress distribution across the width of the workpiece leaving the plastic deformation zone (PDZ) is achieved. A successful ECAP requires surpassing two obstacles: the necessary load level which directly affects tools and a favorable stress distribution so the material withstanding the accumulated strain of repeated deformation. Under back pressure (BP), materials have shown to be able to withstand more passes. As soon as the billet passes the PDZ along the bisector plane of the two channels, the compressive mean stress changes to tensile (leading to crack initiation), while in the presence of BP, a negative (compressive) stress is applied during the process. In this paper a comparative tridimensional finite element analysis (FEA) is performed to evaluate the behavior of a difficult-to-work Al-Mg alloy depending on tools geometry and process parameters. The results in terms of load level and strain distribution show the influence of the punch geometry and BP on the material behavior.

Containment Safety Of Super Phenix : Essai Mars

NASA Astrophysics Data System (ADS)

Falgayrettes, M. F.; Fiche, C.; Hamon, P.

1985-02-01

The protection of people and property must be assured by every situation around an industrial power plant. That is why the FRENCH Commissariat a l'Energie Atomique has defined the size of the confinement of Super Phenix to withstand the worst highly hypothetical accident. The study of the strength of the confinement has been carried out by two complementary means : - Calculation (Display poster # 491 188), - Experiment : reactor mock-up. The latter is presented in the film. The solution which have been adopted for the problems encountered are emphasied ; the work with high speed camera is presented. The film is illustrated with some fast movie sequences.

High resolution temperature mapping of gas turbine combustor simulator exhaust with femtosecond laser induced fiber Bragg gratings

NASA Astrophysics Data System (ADS)

Walker, Robert B.; Yun, Sangsig; Ding, Huimin; Charbonneau, Michel; Coulas, David; Lu, Ping; Mihailov, Stephen J.; Ramachandran, Nanthan

2017-04-01

Femtosecond infrared (fs-IR) laser written fiber Bragg gratings (FBGs), have demonstrated great potential for extreme sensing. Such conditions are inherent in advanced gas turbine engines under development to reduce greenhouse gas emissions; and the ability to measure temperature gradients in these harsh environments is currently limited by the lack of sensors and controls capable of withstanding the high temperature, pressure and corrosive conditions present. This paper discusses fabrication and deployment of several fs-IR written FBG arrays, for monitoring exhaust temperature gradients of a gas turbine combustor simulator. Results include: contour plots of measured temperature gradients, contrast with thermocouple data.

High temperature insulation barrier composite

NASA Technical Reports Server (NTRS)

Onstott, Joseph W. (Inventor)

1989-01-01

A composite material suitable for providing insulation for the nozzle structure of the Space Shuttle and other similar surfaces is disclosed. The composite layer is comprised of an outer skin layer of nickel chromium and an interleaved inner region comprising a top layer of nickel chromium foil which acts as a primary convective shield. There are at least two layers of alumina batting adjacent to the layers of silicon carbide fabric. An additional layer of nickel chromium foil is used as a secondary convective shield. The composite is particularly advantageous for use as nozzle insulation because of its ability to withstand high reentry temperatures, its flexibility, oxidation resistance, low conductivity, and light weight.

Practical Possibilities of High-Altitude Flight with Exhaust-Gas Turbines in Connection with Spark Ignition Engines Comparative Thermodynamic and Flight Mechanical Investigations

NASA Technical Reports Server (NTRS)

Weise, A.

1947-01-01

As a means of preparing for high-altitude flight with spark-ignition engines in conjunction with exhaust-gas turbosuperchargers, various methods of modifying the exhaust-gas temperatures, which are initially higher than a turbine can withstand are mathematically compared. The thermodynamic results first obtained are then examined with respect to the effect on flight speed, climbing speed, ceiling, economy, and cruising range. The results are so presented in a generalized form that they may be applied to every appropriate type of aircraft design and a comparison with the supercharged engine without exhaust-gas turbine can be made.

Oxygen-Permeable, Hydrophobic Membranes of Silanized alpha-Al2O3

NASA Technical Reports Server (NTRS)

Atwater, James E.; Akse, James R.

2006-01-01

Membranes made of silanized alumina have been prepared and tested as prototypes of derivatized ceramic membranes that are both highly permeable to oxygen and hydrophobic. Improved oxygen-permeable, hydrophobic membranes would be attractive for use in several technological disciplines, including supporting high-temperature aqueousphase oxidation in industrial production of chemicals, oxygenation of aqueous streams for bioreactors, and oxygenation of blood during open-heart surgery and in cases of extreme pulmonary dysfunction. In comparison with organic polymeric oxygen-permeable membranes now commercially available, the derivatized ceramic membranes are more chemically robust, are capable of withstanding higher temperatures, and exhibit higher oxygen-diffusion coefficients.

Interface structure for hub and mass attachment in flywheel rotors

DOEpatents

Deteresa, S.J.; Groves, S.E.

1998-06-02

An interface structure is described for hub and mass attachment in flywheel rotors. The interface structure efficiently transmits high radial compression forces and withstands both large circumferential elongation and local stresses generated by mass-loading and hub attachments. The interface structure is comprised of high-strength fiber, such as glass and carbon, woven into an angle pattern which is about 45{degree} with respect to the rotor axis. The woven fiber is bonded by a ductile matrix material which is compatible with and adheres to the rotor material. This woven fiber is able to elongate in the circumferential direction to match the rotor growth during spinning. 2 figs.

Interface structure for hub and mass attachment in flywheel rotors

DOEpatents

Deteresa, Steven J.; Groves, Scott E.

1998-06-02

An interface structure for hub and mass attachment in flywheel rotors. The interface structure efficiently transmits high radial compression forces and withstands both large circumferential elongation and local stresses generated by mass-loading and hub attachments. The interface structure is comprised of high-strength fiber, such as glass and carbon, woven into an angle pattern which is about 45.degree. with respect to the rotor axis. The woven fiber is bonded by a ductile matrix material which is compatible with and adheres to the rotor material. This woven fiber is able to elongate in the circumferential direction to match the rotor growth during spinning.

High Reliability R-10 Windows Using Vacuum Insulating Glass Units

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

Stark, David

2012-08-16

The objective of this effort was for EverSealed Windows (“EverSealed” or “ESW”) to design, assemble, thermally and environmentally test and demonstrate a Vacuum Insulating Glass Unit (“VIGU” or “VIG”) that would enable a whole window to meet or exceed the an R-10 insulating value (U-factor ≤ 0.1). To produce a VIGU that could withstand any North American environment, ESW believed it needed to design, produce and use a flexible edge seal system. This is because a rigid edge seal, used by all other know VIG producers and developers, limits the size and/or thermal environment of the VIG to where themore » unit is not practical for typical IG sizes and cannot withstand severe outdoor environments. The rigid-sealed VIG’s use would be limited to mild climates where it would not have a reasonable economic payback when compared to traditional double-pane or triple-pane IGs. ESW’s goals, in addition to achieving a sufficiently high R-value to enable a whole window to achieve R-10, included creating a VIG design that could be produced for a cost equal to or lower than a traditional triple-pane IG (low-e, argon filled). ESW achieved these goals. EverSealed produced, tested and demonstrated a flexible edge-seal VIG that had an R-13 insulating value and the edge-seal system durability to operate reliably for at least 40 years in the harshest climates of North America.« less

Effect of different seasons on concentration of plasma luteinizing hormone and seminal quality vis-à-vis freezability of buffalo bulls ( Bubalus bubalis)

NASA Astrophysics Data System (ADS)

Bahga, C. S.; Khokar, B. S.

1991-12-01

Seasonal variations in semen quality, freezability and plasma luteinizing hormone (LH) levels were studied between summer and spring. Semen volume, density and initial sperm motility did not differ significantly between different seasons. Plasma LH decreased between summer and spring but the differences were, however, not significant. Pre-freezing motility did not differ significantly but post-freezing motility varied significantly ( P<0.01) between seasons. Post-freezing motility was lowest during summer and highest during winter. It can be concluded that summer spermatozoa may be fragile and cannot withstand freezing stress. To increase reproductive efficiency in buffalo during summer, semen should be frozen during winter and spring and used during hot weather conditions. Seasonal variations in plasma LH levels were insignificant.

New fixed-point mini-cell to investigate thermocouple drift in a high-temperature environment under neutron irradiation

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

Laurie, M.; Vlahovic, L.; Rondinella, V.V.

Temperature measurements in the nuclear field require a high degree of reliability and accuracy. Despite their sheathed form, thermocouples subjected to nuclear radiations undergo changes due to radiation damage and transmutation that lead to significant EMF drift during long-term fuel irradiation experiment. For the purpose of a High Temperature Reactor fuel irradiation to take place in the High Flux Reactor Petten, a dedicated fixed-point cell was jointly developed by LNE-Cnam and JRC-IET. The developed cell to be housed in the irradiation rig was tailor made to quantify the thermocouple drift during the irradiation (about two year duration) and withstand highmore » temperature (in the range 950 deg. C - 1100 deg. C) in the presence of contaminated helium in a graphite environment. Considering the different levels of temperature achieved in the irradiation facility and the large palette of thermocouple types aimed at surveying the HTR fuel pebble during the qualification test both copper (1084.62 deg. C) and gold (1064.18 deg. C) fixed-point materials were considered. The aim of this paper is to first describe the fixed-point mini-cell designed to be embedded in the reactor rig and to discuss the preliminary results achieved during some out of pile tests as much as some robustness tests representative of the reactor scram scenarios. (authors)« less

High Temperature Thermographic Phosphor Coatings Development

NASA Technical Reports Server (NTRS)

Goedeke, Shawn; Allison, S. W.; Beshears, D. L.; Bencic, T.; Cates, M. R.; Hollerman, W. A.; Guidry, R.

2003-01-01

For many years, phosphor thermometry has been used for non-contact temperature measurements. A large number of applications have been associated with high temperatures, especially for aerospace systems where blackbody radiation backgrounds are large and in challenging environments, such as vibration, rotation, flame, or noise. These environments restrict the use of more common thermocouples or infrared thermometric techniques. In particular, temperature measurements inside jet turbines, rocket engines, or similar devices are especially amenable to phosphor techniques. Often the fluorescent materials are used as powders, either suspended in binders and applied like paint or applied as high-temperature sprays. Thin coatings that are less than 50 m thick are used on the surfaces of interest. These coatings will quickly assume the same temperature as the surface to which they are applied. The temperature dependence of fluorescent materials is a function of the base matrix atoms and a small quantity of added activator or dopant ions. Often for high temperature applications, the selected materials are refractory and include rare earth ions. Phosphors like Y3Al5O12 (YAG) doped with Eu, Dy, or Tm, Y2O3 doped with Eu, or similar rare earth compounds, will survive high temperatures and can be configured to emit light that changes rapidly in lifetime and intensity. For example, researchers at Oak Ridge National Laboratory recently observed fluorescence from YAG:Dy and YAG:Tm at temperatures above 1400 C. One of the biggest challenges is to locate a binder material that can withstand tremendous variations in temperature in an adverse aerospace environment. This poster will provide an overview into our attempt to utilize phosphors for thermometry purposes. Emphasis will be placed on the use of selected binder materials that can withstand high temperatures. This research was completed for the National Aeronautics and Space Administration's Glenn Research Center in Cleveland, Ohio.

Estimating genetic potential of biofuel forest hardwoods to withstand metal toxicity in industrial effluent under dry tropical conditions.

PubMed

Manzoor, S A; Mirza, S N; Zubair, M; Nouman, W; Hussain, S B; Mehmood, S; Irshad, A; Sarwar, N; Ammar, A; Iqbal, M F; Asim, A; Chattha, M U; Chattha, M B; Zafar, A; Abid, R

2015-08-14

Biofuel tree species are recognized as a promising alternative source of fuel to conventional forms. Additionally, these tree species are also effective in accumulating toxic heavy metals present in some industrial effluents. In developing countries such as Pakistan, the use of biofuel tree species is gaining popularity not only for harvesting economical and environmentally friendly biofuel, but also to sequester poisonous heavy metals from industrial wastewater. This study was aimed at evaluating the genetic potential of two biofuel species, namely, Jatropha curcas and Pongamia pinnata, to grow when irrigated with industrial effluent from the Pak-Arab Fertilizer Factory Multan, Southern Punjab, Pakistan. The growth performances of one-year-old seedlings of both species were compared in soil with adverse physiochemical properties. It was found that J. curcas was better able to withstand the toxicity of the heavy metals present in the fertilizer factory effluent. J. curcas showed maximum gain in height, diameter, and biomass production in soil irrigated with 75% concentrated industrial effluent. In contrast, P. pinnata showed a significant reduction in growth in soil irrigated with more than 50% concentrated industrial effluent, indicating that this species is less tolerant to higher toxicity levels of industrial effluent. This study identifies J. curcas as a promising biofuel tree species that can be grown using industrial wastewater.

Rocket engine injectorhead with flashback barrier

NASA Technical Reports Server (NTRS)

Mungas, Gregory S. (Inventor); Fisher, David J. (Inventor); Mungas, Christopher (Inventor)

2012-01-01

Propellants flow through specialized mechanical hardware that is designed for effective and safe ignition and sustained combustion of the propellants. By integrating a micro-fluidic porous media element between a propellant feed source and the combustion chamber, an effective and reliable propellant injector head may be implemented that is capable of withstanding transient combustion and detonation waves that commonly occur during an ignition event. The micro-fluidic porous media element is of specified porosity or porosity gradient selected to be appropriate for a given propellant. Additionally the propellant injector head design integrates a spark ignition mechanism that withstands extremely hot running conditions without noticeable spark mechanism degradation.

SEALED INSULATOR BUSHING

DOEpatents

Carmichael, H.

1952-11-11

The manufacture of electrode insulators that are mechanically strong, shock-proof, vacuum tight, and are capable of withstanding gas pressures of many atmospheres under intense neutron bombardment, such as may be needed in an ionization chamber, is described. The ansulator comprises a bolt within a quartz tube, surrounded by a bushing held in place by two quartz rings, and tightened to a pressure of 1,000 pounds per square inch by a nut and washer. Quartz is the superior material to meet these conditions, however, to withstand this pressure the quartz must be fire polished, lapped to form smooth and parallel surfaces, and again fire polished to form an extremely smooth and fracture resistant mating surface.

Robustness and Recovery of Lifeline Infrastructure and Ecosystem Networks

NASA Astrophysics Data System (ADS)

Bhatia, U.; Ganguly, A. R.

2015-12-01

Disruptive events, both natural and man-made, can have widespread impacts on both natural systems and lifeline infrastructure networks leading to the loss of biodiversity and essential functionality, respectively. Projected sea-level rise and climate change can further increase the frequency and severity of large-scale floods on urban-coastal megacities. Nevertheless, Failure in infrastructure systems can trigger cascading impacts on dependent ecosystems, and vice-versa. An important consideration in the behavior of the isolated networks and inter-connected networks following disruptive events is their resilience, or the ability of the network to "bounce back" to a pre-disaster state. Conventional risk analysis and subsequent risk management frameworks have focused on identifying the components' vulnerability and strengthening of the isolated components to withstand these disruptions. But high interconnectedness of these systems, and evolving nature of hazards, particularly in the context of climate extremes, make the component level analysis unrealistic. In this study, we discuss the complex network-based resilience framework to understand fragility and recovery strategies for infrastructure systems impacted by climate-related hazards. We extend the proposed framework to assess the response of ecological networks to multiple species loss and design the restoration management framework to identify the most efficient restoration sequence of species, which can potentially lead to disproportionate gains in biodiversity.

Sensing and Responding to UV-A in Cyanobacteria

PubMed Central

Moon, Yoon-Jung; Kim, Seung Il; Chung, Young-Ho

2012-01-01

Ultraviolet (UV) radiation can cause stresses or act as a photoregulatory signal depending on its wavelengths and fluence rates. Although the most harmful effects of UV on living cells are generally attributed to UV-B radiation, UV-A radiation can also affect many aspects of cellular processes. In cyanobacteria, most studies have concentrated on the damaging effect of UV and defense mechanisms to withstand UV stress. However, little is known about the activation mechanism of signaling components or their pathways which are implicated in the process following UV irradiation. Motile cyanobacteria use a very precise negative phototaxis signaling system to move away from high levels of solar radiation, which is an effective escape mechanism to avoid the detrimental effects of UV radiation. Recently, two different UV-A-induced signaling systems for regulating cyanobacterial phototaxis were characterized at the photophysiological and molecular levels. Here, we review the current understanding of the UV-A mediated signaling pathways in the context of the UV-A perception mechanism, early signaling components, and negative phototactic responses. In addition, increasing evidences supporting a role of pterins in response to UV radiation are discussed. We outline the effect of UV-induced cell damage, associated signaling molecules, and programmed cell death under UV-mediated oxidative stress. PMID:23208372

Summary of Uranium Solubility Studies in Concrete Waste Forms and Vadose Zone Environments

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

Golovich, Elizabeth C.; Wellman, Dawn M.; Serne, R. Jeffrey

2011-09-30

One of the methods being considered for safely disposing of Category 3 low-level radioactive wastes is to encase the waste in concrete. Concrete encasement would contain and isolate the waste packages from the hydrologic environment and act as an intrusion barrier. The current plan for waste isolation consists of stacking low-level waste packages on a trench floor, surrounding the stacks with reinforced steel, and encasing these packages in concrete. These concrete-encased waste stacks are expected to vary in size with maximum dimensions of 6.4 m long, 2.7 m wide, and 4 m high. The waste stacks are expected to havemore » a surrounding minimum thickness of 15 cm of concrete encasement. These concrete-encased waste packages are expected to withstand environmental exposure (solar radiation, temperature variations, and precipitation) until an interim soil cover or permanent closure cover is installed and to remain largely intact thereafter. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. This report presents the results of investigations elucidating the uranium mineral phases controlling the long-term fate of uranium within concrete waste forms and the solubility of these phases in concrete pore waters and alkaline, circum-neutral vadose zone environments.« less

Graphite and ablative material response to CO2 laser, carbon-arc, and xenon-arc radiation

NASA Technical Reports Server (NTRS)

Brewer, W. D.

1976-01-01

The behavior was investigated of graphite and several charring ablators in a variety of high-radiative heat-flux environments. A commercial-grade graphite and nine state-of-the-art charring ablators were subjected to various radiative environments produced by a CO2 laser and a carbon arc. Graphite was also tested in xenon-arc radiation. Heat-flux levels ranged from 10 to 47 MW/sq m. Tests were conducted in air, nitrogen, helium, and a CO2-N2 mixture which simulated the Venus atmosphere. The experimental results were compared with theoretical results obtained with a one-dimensional charring-ablator analysis and a two-dimensional subliming-ablator analysis. Neither the graphite nor the charring ablators showed significant differences in appearance or microstructure after testing in the different radiative environments. The performance of phenolic nylon and graphite was predicted satisfactorily with existing analyses and published material property data. Good agreement between experimental and analytical results was obtained by using sublimation parameters from a chemical nonequilibrium analysis of graphite sublimation. Some charring ablators performed reasonably well and could withstand radiative fluxes of the level encountered in certain planetary entries. Other materials showed excessive surface recession and/or large amounts of cracking and spalling, and appear to be unsuitable for severe radiative environments.

Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology

NASA Technical Reports Server (NTRS)

Chullen, Cinda

2015-01-01

Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology" project will investigate newly developed optic gas sensors delivered from a Small Business Innovative Research (SBIR) Phase II effort. A ventilation test rig will be designed and fabricated to test the sensors while integrated with a Suited Manikin Test Apparatus (SMTA). Once the sensors are integrated, a series of test points will be completed to verify that the sensors can withstand Advanced Suit Portable Life Support System (PLSS) environments and associated human metabolic profiles for changes in pressure and levels of Oxygen (ppO2), carbon dioxide (ppCO2), and humidity (ppH2O).

Measuring Fluctuating Pressure Levels and Vibration Response in a Jet Plume

NASA Technical Reports Server (NTRS)

Osterholt, Douglas J.; Knox, Douglas M.

2011-01-01

The characterization of loads due to solid rocket motor plume impingement allows for moreaccurate analyses of components subjected to such an environment. Typically, test verification of predicted loads due to these conditions is widely overlooked or unsuccessful. ATA Engineering, Inc., performed testing during a solid rocket motor firing to obtain acceleration and pressure responses in the hydrodynamic field surrounding the jet plume. The test environment necessitated a robust design to facilitate measurements being made in close proximity to the jet plume. This paper presents the process of designing a test fixture and an instrumentation package that could withstand the solid rocket plume environment and protect the required instrumentation.

Electromagnetic Pumps for Liquid Metal-Fed Electric Thrusters

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Markusic, Thomas E.

2007-01-01

Prototype designs of two separate pumps for use in electric propulsion systems with liquid lithium and bismuth propellants are presented. Both pumps are required to operate at elevated temperatures, and the lithium pump must additionally withstand the corrosive nature of the propellant. Compatibility of the pump materials and seals with lithium and bismuth were demonstrated through proof-of-concept experiments followed by post-experiment visual inspections. The pressure rise produced by the bismuth pump was found to be linear with input current and ranged from 0-9 kPa for corresponding input current levels of 0-30 A, showing good quantitative agreement with theoretical analysis.

2008 United States National Seismic Hazard Maps

USGS Publications Warehouse

Petersen, M.D.; ,

2008-01-01

The U.S. Geological Survey recently updated the National Seismic Hazard Maps by incorporating new seismic, geologic, and geodetic information on earthquake rates and associated ground shaking. The 2008 versions supersede those released in 1996 and 2002. These maps are the basis for seismic design provisions of building codes, insurance rate structures, earthquake loss studies, retrofit priorities, and land-use planning. Their use in design of buildings, bridges, highways, and critical infrastructure allows structures to better withstand earthquake shaking, saving lives and reducing disruption to critical activities following a damaging event. The maps also help engineers avoid costs from over-design for unlikely levels of ground motion.

Biaxial Testing of High-Strength Fabric Improves Design of Inflatable Radar Domes

NASA Technical Reports Server (NTRS)

Krause, David L.; Bartolotta, Paul A.

2001-01-01

Large radar installations around the globe continuously watch the skies, unobtrusively providing security to the United States; these systems have been in active use for the past 50 years. Often situated in extreme environments, the radar dishes require shielding from the harsh elements. Air-inflated domes (over 100 ft in diameter) are one structure of choice for providing this essential protection. The radomes are constructed from highstrength fabric that is strong enough to withstand the inflation pressure, high winds, and other environmental loads, yet transparent to the microwave signal to allow precise radar mapping. This fabric is woven from glass fibers for high strength and embedded in a polytetrafluoroethylene resin matrix, akin to the nonstick coatings used on cookware.

Thermal stability of carbon nanotubes probed by anchored tungsten nanoparticles

PubMed Central

Wei, Xianlong; Wang, Ming-Sheng; Bando, Yoshio; Golberg, Dmitri

2011-01-01

The thermal stability of multiwalled carbon nanotubes (CNTs) was studied in high vacuum using tungsten nanoparticles as miniaturized thermal probes. The particles were placed on CNTs inside a high-resolution transmission electron microscope equipped with a scanning tunneling microscope unit. The setup allowed manipulating individual nanoparticles and heating individual CNTs by applying current to them. CNTs were found to withstand high temperatures, up to the melting point of 60-nm-diameter W particles (∼3400 K). The dynamics of W particles on a hot CNT, including particle crystallization, quasimelting, melting, sublimation and intradiffusion, were observed in real time and recorded as a video. Graphite layers reel off CNTs when melted or premelted W particles revolve along the tube axis. PMID:27877413

Multi-party quantum private comparison based on the entanglement swapping of d-level cat states and d-level Bell states

NASA Astrophysics Data System (ADS)

Zhao-Xu, Ji; Tian-Yu, Ye

2017-07-01

In this paper, a novel multi-party quantum private comparison protocol with a semi-honest third party (TP) is proposed based on the entanglement swapping of d-level cat states and d-level Bell states. Here, TP is allowed to misbehave on his own, but will not conspire with any party. In our protocol, n parties employ unitary operations to encode their private secrets and can compare the equality of their private secrets within one time execution of the protocol. Our protocol can withstand both the outside attacks and the participant attacks on the condition that none of the QKD methods is adopted to generate keys for security. One party cannot obtain other parties' secrets except for the case that their secrets are identical. The semi-honest TP cannot learn any information about these parties' secrets except the end comparison result on whether all private secrets from n parties are equal.

Irish nursing students' changing levels of assertiveness during their pre-registration programme.

PubMed

Begley, Cecily M; Glacken, Michèle

2004-10-01

Stress and bullying have been found to be common problems in a number of studies of Irish nursing and midwifery. Victims of bullying need high levels of assertiveness to enable them to withstand the stress of victimization. It was deemed important to measure nursing students' level of assertiveness prior to, and near completion of, their pre-registration education programme. Aim. To ascertain nursing students' perceived levels of assertiveness prior to, and nearing the completion of, their three-year pre-registration programme. Ethical approval was given. The students commencing general nurse education programmes in two schools in Southern Ireland agreed to take part (n=72). A questionnaire adapted from a number of assertiveness scales, and tested for validity and reliability in this population, was used to collect data. In general, students' reported assertiveness levels rose as they approached completion of their three-year education programme. The resource constrained health service of the 21st century requires nurses who are assertive to meet the needs of its users. Nursing students' assertiveness skills could be augmented through concentrated efforts from nurse educationalists and clinicians to reduce the communication theory practice gap in nurse education today. To address the multi-dimensional nature of assertiveness, strategies to increase assertiveness should operate at the individual, interface and organisational level. The students in this study reported an increase in levels of assertiveness as they approached completion of their three-year education programme. To function as effective, safe practitioners registered nurses need to be assertive, therefore education in assertiveness should be an integral part of their preparation. The precise composition and mode of delivery of this education requires exploration and evaluation.

Modeling warming predicts a physiological threshold for the extinction of the living fossil frog Calyptocephalella gayi.

PubMed

Vidal, Marcela A; Novoa-Muñoz, Francisco; Werner, Enrique; Torres, Cristian; Nova, Ricardo

2017-10-01

Global climate change will have a greater impact on ectotherms in tropical and subtropical communities than at higher latitudes, because ambient temperatures are closer to the upper thermal limits of species. Amphibian species are highly dependent on external weather conditions, and the effect of global warming on these has been evaluated recently. The Great Chilean frog (Calyptocephalella gayi) is an endemic, monotypic species and genus whose conservation status is considered Vulnerable because of high extraction pressure for human consumption, lack of regulatory measures and comprehension by its consumers. Their populations have also declined due to the loss and destruction of their habitats. C. gayi has not been considered as an object of physiological study, so this large species is not known as one that can adapt to current environmental changes. In this study we analyze the thermoregulatory capacity and thermal efficiency of C. gayi to determine its potential for climatic adaptation. The results indicate that this species is strictly a thermal-conformer; its thermal efficiency and its ability to withstand high temperatures allow it to sustain itself under a climate change scenario, however, it has thermal constraints that do not allow it to withstand temperatures greater than 30°C. By modeling its ontogenetic conditions mathematically, we project that the larvae are not in danger, although there is a group of around 4% which is very close to 30°C, which is the highest temperature recorded for the species. However, about 40% of subadults and approximately 47% of adult frogs will not survive the change of ~7°C projected for the following 85 years, which will affect future generations. Copyright © 2017 Elsevier Ltd. All rights reserved.

NTREES Testing and Operations Status

NASA Technical Reports Server (NTRS)

Emrich, Bill

2007-01-01

Nuclear Thermal Rockets or NTR's have been suggested as a propulsion system option for vehicles traveling to the moon or Mars. These engines are capable of providing high thrust at specific impulses at least twice that of today's best chemical engines. The performance constraints on these engines are mainly the result of temperature limitations on the fuel coupled with a limited ability to withstand chemical attack by the hot hydrogen propellant. To operate at maximum efficiency, fuel forms are desired which can withstand the extremely hot, hostile environment characteristic of NTR operation for at least several hours. The simulation of such an environment would require an experimental device which could simultaneously approximate the power, flow, and temperature conditions which a nuclear fuel element (or partial element) would encounter during NTR operation. Such a simulation would allow detailed studies of the fuel behavior and hydrogen flow characteristics under reactor like conditions to be performed. Currently, the construction of such a simulator has been completed at the Marshall Space Flight Center, and will be used in the future to evaluate a wide variety of fuel element designs and the materials of which they are fabricated. This present work addresses the operational status of the Nuclear Thermal Rocket Element Environmental Simulator or NTREES and some of the design considerations which were considered prior to and during its construction.

Dentinal tubules occluded by bioactive glass-containing toothpaste exhibit high resistance toward acidic soft drink challenge.

PubMed

Bakri, M M; Hossain, M Z; Razak, F A; Saqina, Z H; Misroni, A A; Ab-Murat, N; Kitagawa, J; Saub, R B

2017-06-01

Dentine hypersensitivity is a common problem attributed by patent dentinal tubules. Ingredients incorporated in toothpastes aim to occlude patent dentinal tubules to minimize the dentine hypersensitivity. However, frequent consumption of acidic soft drinks may reverse the dentinal tubules' occlusion. In this in vitro study, the efficacy of dentinal tubules occluded by commercially available toothpastes to withstand different durations of an acidic soft drink challenge was investigated. One hundred and twenty dentine discs were divided into three groups. The discs from each group were brushed with toothpaste containing bioactive glass, arginine and control toothpaste. Each group was then divided into four subgroups and exposed to acidic soft drink over four different time durations. The scoring and the percentage of occluded dentinal tubules by Novamin-containing toothpaste was significantly better compared with arginine or the control toothpaste. Acidic soft drink challenge reduced the extent of dentinal tubules occlusion along with time. Dentinal tubules occluded by Novamin-containing toothpaste withstand the acidic challenge comparatively for a longer period. The findings demonstrated that occlusion of dentinal tubules is more efficient by the bioactive glass-containing toothpaste and thus may contribute to its better resistance to acidic soft drink challenge. © 2016 Australian Dental Association.

Analysis of thermal radiation in coal-fired furnaces

NASA Astrophysics Data System (ADS)

Miles, Jonathan J.; Hammaker, Robert G.; Madding, Robert P.; Sunderland, J. E.

1997-04-01

Many utilities throughout the United States have added infrared scanning to their arsenal of techniques for inspection and predictive maintenance programs. Commercial infrared scanners are not designed, however, to withstand the searing interiors of boilers, which can exceed 2500 degrees Fahrenheit. Two high-temperature lenses designed to withstand the hostile environment inside a boiler for extended periods of time were developed by the EPRI M&D Center, thus permitting real-time measurement of steam tube temperatures and subsequent analysis of tube condition, inspection of burners, and identification of hot spots. A study was conducted by Sunderland Engineering, Inc. and EPRI M&D in order to characterize the radiative interactions that affect infrared measurements made inside a commercial, coal- fired, water-tube boiler. A comprehensive literature search exploring the existing record of results pertaining to analytical and experimental determination of radiative properties of coal-combustion byproducts was performed. An experimental component intended to provide data for characterization of the optical properties of hot combustion byproducts inside a coal-fired furnace was carried out. The results of the study indicate that hot gases, carbon particles, and fly ash, which together compose the medium inside a boiler, affect to varying degrees the transport of infrared radiation across a furnace. Techniques for improved infrared measurement across a coal-fired furnace are under development.

Development of a Thin Film Solar Cell Interconnect for the Powersphere Concept

NASA Technical Reports Server (NTRS)

Simburger, Edward J.; Matsumoto, James H.; Giants, Thomas W.; Garcia, Alexander, III; Liu, Simon; Rawal, Suraj P.; Perry, Alan R.; Marshall, Craig H.; Lin, John K.; Scarborough, Stephen

2003-01-01

Progressive development of microsatellite technologies has resulted in increased demand for lightweight electrical power subsystems including solar arrays. The use of thin film photovoltaics has been recognized as a key solution to meet the power needs. The lightweight cells can generate sufficient power and still meet critical mass requirements. Commercially available solar cells produced on lightweight substrates are being studied as an option to fulfill the power needs. The commercially available solar cells are relatively inexpensive and have a high payoff potential. Commercially available thin film solar cells are primarily being produced for terrestrial applications. The need to convert the solar cell from a terrestrial to a space compatible application is the primary challenge. Solar cell contacts, grids and interconnects need to be designed to be atomic oxygen resistant and withstand rapid thermal cycling environments. A mechanically robust solar cell interconnect is also required in order to withstand handling during fabrication and survive during launch. The need to produce the solar cell interconnects has been identified as a primary goal of the Powersphere program and is the topic of this paper. Details of the trade study leading to the final design involving the solar cell wrap around contact, flex blanket, welding process, and frame will be presented at the conference.

Robust, Thin Optical Films for Extreme Environments

NASA Technical Reports Server (NTRS)

2006-01-01

The environment of space presents scientists and engineers with the challenges of a harsh, unforgiving laboratory in which to conduct their scientific research. Solar astronomy and X-ray astronomy are two of the more challenging areas into which NASA scientists delve, as the optics for this high-tech work must be extremely sensitive and accurate, yet also be able to withstand the battering dished out by radiation, extreme temperature swings, and flying debris. Recent NASA work on this rugged equipment has led to the development of a strong, thin film for both space and laboratory use.

Woven Hybrid Composites - Tensile and Flexural Properties of Jute Mat Fibres with Epoxy Composites

NASA Astrophysics Data System (ADS)

Gopal, P.; Bupesh Raja, V. K.; Chandrasekaran, M.; Dhanasekaran, C.

2017-03-01

The jute mat fibers are fabricated with several layers of fiber with opposite orientation in addition with coconut shell powder and resins. In current trends, metallic components are replaced by natural fibers because of the inherent properties such as light in weight, easy to fabricate, less cost and easy availability. This material has high strength and withstands the load. In this investigation the plates are made without stitching the fiber. The result of tensile strength and flexural strength are compared with nano material (coconut shell powder).

Planarised optical fiber composite using flame hydrolysis deposition demonstrating an integrated FBG anemometer.

PubMed

Holmes, Christopher; Gates, James C; Smith, Peter G R

2014-12-29

This paper reports for the first time a planarised optical fiber composite formed using Flame Hydrolysis Deposition (FHD). As a way of format demonstration a Micro-Opto-Electro-Mechanical (MOEMS) hot wire anemometer is formed using micro-fabrication processing. The planarised device is rigidly secured to a silicon wafer using optical quality doped silica that has been deposited using flame hydrolysis and consolidated at high temperature. The resulting structure can withstand temperatures exceeding 580K and is sensitive enough to resolve free and forced convection interactions at low fluid velocity.

Mechanical beam isolator for high-power laser systems

DOEpatents

Post, R.F.; Vann, C.S.

1998-07-07

A mechanical beam isolator uses rod-shaped elements having a Gaussian configuration to interrupt the path of a beam of photons or particles when the time-scale of the needed interruption is of the order of a microsecond or less. One or more of these rods is mounted transversely to, and penetrates through, a rotating shaft supported by bearings. Owing to the Gaussian geometry of the rods, they are able to withstand much higher rotation speeds, without tensile failure, than rods having any other geometrical shape. 3 figs.

Thermally Stable Nanocrystalline Steel

NASA Astrophysics Data System (ADS)

Hulme-Smith, Christopher Neil; Ooi, Shgh Woei; Bhadeshia, Harshad K. D. H.

2017-10-01

Two novel nanocrystalline steels were designed to withstand elevated temperatures without catastrophic microstructural changes. In the most successful alloy, a large quantity of nickel was added to stabilize austenite and allow a reduction in the carbon content. A 50 kg cast of the novel alloy was produced and used to verify the formation of nanocrystalline bainite. Synchrotron X-ray diffractometry using in situ heating showed that austenite was able to survive more than 1 hour at 773 K (500 °C) and subsequent cooling to ambient temperature. This is the first reported nanocrystalline steel with high-temperature capability.

Formal design and verification of a reliable computing platform for real-time control. Phase 2: Results

NASA Technical Reports Server (NTRS)

Butler, Ricky W.; Divito, Ben L.

1992-01-01

The design and formal verification of the Reliable Computing Platform (RCP), a fault tolerant computing system for digital flight control applications is presented. The RCP uses N-Multiply Redundant (NMR) style redundancy to mask faults and internal majority voting to flush the effects of transient faults. The system is formally specified and verified using the Ehdm verification system. A major goal of this work is to provide the system with significant capability to withstand the effects of High Intensity Radiated Fields (HIRF).

Echo 30" Sub Satellite

NASA Image and Video Library

2012-09-07

James Hansen describes the work on Project Echo s air density experiment known as the Sub-Satellite. Before launch engineers subjected the sub-satellite to many tests. Here, the sub-satellite is shown prior to tests to determine the capacity of the 30-inch Sub-Satellite to withstand the high temperature of direct sunlight in space, Langley researchers subjected it to 450 F heat test. Results indicated that the aluminum-covered Mylar plastic would effectively reflect the dangerous heat. -- Published in James R. Hansen, Spaceflight Revolution: NASA Langley Research Center From Sputnik to Apollo, NASA SP-4308, p. 168.

Critical concerns, solutions and guidelines for use of plastic encapsulated microcircuits for space flight applications

NASA Technical Reports Server (NTRS)

Virmani, Nick; Shaw, Jack

1997-01-01

Some of the concerns and risk mitigation procedures for using plastic encapsulated microcircuits (PEMs) for space applications are discussed. Despite their advantages, PEMs cannot be implemented in all space applications by replacing military parts numbers with their commercial counterparts in product designs and part lists. The technical and procurement concerns are summarized, and suggestions for high reliability procurements are given. The ability to withstand deleterious environmental effects and to meet mission critical reliability is the key to the successful use of PEMs for space applications.

Robust, directed assembly of fluorescent nanodiamonds.

PubMed

Kianinia, Mehran; Shimoni, Olga; Bendavid, Avi; Schell, Andreas W; Randolph, Steven J; Toth, Milos; Aharonovich, Igor; Lobo, Charlene J

2016-10-27

Arrays of fluorescent nanoparticles are highly sought after for applications in sensing, nanophotonics and quantum communications. Here we present a simple and robust method of assembling fluorescent nanodiamonds into macroscopic arrays. Remarkably, the yield of this directed assembly process is greater than 90% and the assembled patterns withstand ultra-sonication for more than three hours. The assembly process is based on covalent bonding of carboxyl to amine functional carbon seeds and is applicable to any material, and to non-planar surfaces. Our results pave the way to directed assembly of sensors and nanophotonics devices.

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

Rice, John A.

A new, all ceramic magnet insulation system has been developed that can withstand the high radiation doses without significant damage. The insulation can be applied directly onto a Nb3Sn or copper cable as a ceramic based prepreg system using the same equipment and procedures used for the traditional epoxy systems. Excessive porosity was eliminated and compressions strength increased. Thermal expansion nearly matches the expansion of niobium tin conductor wire. A radiation test program has been defined and magnet fabrication issues have been identified. This report covers the results of the Phase I research program.

Doctor, where is my iris?

PubMed

Sophocleous, Sophocles

2016-05-05

Phacoemulsification cataract surgery with small clear corneal incision (CCI) is the standard of care for cataract treatment. Self-sealing, clear corneal wounds have been found to be stable and able to withstand high pressures. Nevertheless, there are a few cases published describing patients with previous cataract surgery and manually performed CCI who sustained blunt trauma with associated wound dehiscence, iris disinsertion and expulsion through the wound. The case described here demonstrates an eye that had traumatic aniridia post-blunt trauma, while the intraocular lens and the rest of the ocular structures remained intact. 2016 BMJ Publishing Group Ltd.

Highly conductive metal interconnects on three-dimensional objects fabricated with omnidirectional ink jet printing technology

NASA Astrophysics Data System (ADS)

Yoshida, Yasunori; Wada, Hikaru; Izumi, Konami; Tokito, Shizuo

2017-05-01

In this work, we demonstrate that highly conductive metal interconnects can be fabricated on the surface of three-dimensional objects using “omnidirectional ink jet” (OIJ) printing technology. OIJ printing technology makes it possible to perform ink jet printing in all directions by combining the motion of a 6-axis vertically articulated robot with precise positioning and a thermal drying process, which allows for the printing of stacked layers. By using OIJ technology, we were the first to successfully fabricate printed interconnect layers having a very low electrical resistance of 12 mΩ over a 10 mm length. Moreover, the results of the high-current test demonstrated that the printed interconnects can withstand high-current-flow of 5 A for 30 min or more.

Optimization of a high-pressure pore water extraction device.

PubMed

Cyr, Martin; Daidié, Alain

2007-02-01

High-pressure squeezing is a technique used for the extraction of the pore water of porous materials such as sediments, soils, rocks, and concrete. The efficiency of extraction depends on the maximum pressures on the materials. This article presents the design of a high-pressure device reaching an axial pressure of 1000 MPa which has been developed to improve the efficiency of extraction. The increase in squeezing pressure implies high stresses inside the chamber, so specialized expertise was required to design a safe, functional device that could withstand pressures significantly higher than common laboratory equipment. The design includes finite element calculations, selection of appropriate materials, and descriptive construction details for the apparatus. It also includes an experimental study of the performance of the apparatus in terms of extraction efficiency.

Laser-machined microcavities for simultaneous measurement of high-temperature and high-pressure.

PubMed

Ran, Zengling; Liu, Shan; Liu, Qin; Huang, Ya; Bao, Haihong; Wang, Yanjun; Luo, Shucheng; Yang, Huiqin; Rao, Yunjiang

2014-08-07

Laser-machined microcavities for simultaneous measurement of high-temperature and high-pressure are demonstrated. These two cascaded microcavities are an air cavity and a composite cavity including a section of fiber and an air cavity. They are both placed into a pressure chamber inside a furnace to perform simultaneous pressure and high-temperature tests. The thermal and pressure coefficients of the short air cavity are ~0.0779 nm/°C and ~1.14 nm/MPa, respectively. The thermal and pressure coefficients of the composite cavity are ~32.3 nm/°C and ~24.4 nm/MPa, respectively. The sensor could be used to separate temperature and pressure due to their different thermal and pressure coefficients. The excellent feature of such a sensor head is that it can withstand high temperatures of up to 400 °C and achieve precise measurement of high-pressure under high temperature conditions.

Considerations in development and implementation of elasto-viscoplastic constitutive model for high temperature applications

NASA Technical Reports Server (NTRS)

Riff, Richard

1988-01-01

The prediction of inelastic behavior of metallic materials at elevated temperatures has increased in importance in recent years. The operating conditions within the hot section of a rocket motor or a modern gas turbine engine present an extremely harsh thermomechanical environment. Large thermal transients are induced each time the engine is started or shut down. Additional thermal transients from an elevated ambient occur whenever the engine power level is adjusted to meet flight requirements. The structural elements employed in such hot sections, as well as any engine components located therein, must be capable of withstanding such extreme conditions. Failure of a component would, due to the critical nature of the hot section, lead to an immediate and catastrophic loss in power. Consequently, assuring satisfactory long term performance for such components is a major concern. Nonisothermal loading of structures often causes excursion of stress well into the inelastic range. Moreover, the influence of geometry changes on the response is also significant in most cases. Therefore, both material and geometric nonlinear effects are considered.

Relationship Between Resilience and Coping Strategies in Competitive Sport.

PubMed

Secades, Xabel García; Molinero, Olga; Salguero, Alfonso; Barquín, Roberto Ruíz; de la Vega, Ricardo; Márquez, Sara

2016-02-01

Resilience is important in sport performers to withstand the pressure they experience. This study analyzed the relationship among resilient qualities and coping strategies in 235 Spanish athletes (126 males, 109 females; M age = 20.7 yr) who practiced different sports (79.1% team sports, 20.9% individual sports). They were evaluated at the beginning of the last competitive mesocycle and after an important competition. Coping strategies and level of resilient qualities were measured by the Coping Inventory for Competitive Sport and the Resilience Scale. There was no significant difference in resilience scores between evaluations performed during the last mesocycle or competition. A significant increase occurred in the scores for emotion-oriented and distraction-oriented coping during competition. Resilience scores correlated positively to task-oriented coping and negatively to disengagement- and distraction-oriented coping during both periods. Analysis of variance indicated that athletes with high individual resilient qualities reached higher scores in task-oriented coping, using to a lower extent disengagement- and distraction-oriented coping. Results obtained suggest that resilient characteristics may associate in athletes to the use of more potentially adaptative coping strategies. © The Author(s) 2016.

Not All Smokers Die Young: A Model for Hidden Heterogeneity within the Human Population

PubMed Central

Levine, Morgan; Crimmins, Eileen

2014-01-01

The ability of some individuals to reach extreme old age in the presence of clearly high exposure to damaging factors may signal an innate biological advantage. For this study we used data on 4,655 current and never smokers, ages 50 and above, from NHANES III to examine whether long-lived smokers represent a biologically resilient phenotype that could facilitate our understanding of heterogeneity in the aging process. Using a proportional hazards model, our results showed that while smoking significantly increased mortality in most age groups, it did not increase the mortality risk for those who were age 80 and over at baseline. Additionally when comparing the adjusted means of biomarkers between never and current smokers, we found that long-lived smokers (80+) had similar inflammation, HDL, and lung function levels to never smokers. Given that factors which allow some individuals to withstand smoking may also enable others to cope with everyday biological stressors, the investigation of long-lived smokers may eventually allow us to identify molecular and genetic mechanisms which enable longevity extension. PMID:24520332

CIP (cleaning-in-place) stability of AlGaN/GaN pH sensors.

PubMed

Linkohr, St; Pletschen, W; Schwarz, S U; Anzt, J; Cimalla, V; Ambacher, O

2013-02-20

The CIP stability of pH sensitive ion-sensitive field-effect transistors based on AlGaN/GaN heterostructures was investigated. For epitaxial AlGaN/GaN films with high structural quality, CIP tests did not degrade the sensor surface and pH sensitivities of 55-58 mV/pH were achieved. Several different passivation schemes based on SiO(x), SiN(x), AlN, and nanocrystalline diamond were compared with special attention given to compatibility to standard microelectronic device technologies as well as biocompatibility of the passivation films. The CIP stability was evaluated with a main focus on the morphological stability. All stacks containing a SiO₂ or an AlN layer were etched by the NaOH solution in the CIP process. Reliable passivations withstanding the NaOH solution were provided by stacks of ICP-CVD grown and sputtered SiN(x) as well as diamond reinforced passivations. Drift levels about 0.001 pH/h and stable sensitivity over several CIP cycles were achieved for optimized sensor structures. Copyright © 2012 Elsevier B.V. All rights reserved.

Plant Tolerance: A Unique Approach to Control Hemipteran Pests.

PubMed

Koch, Kyle G; Chapman, Kaitlin; Louis, Joe; Heng-Moss, Tiffany; Sarath, Gautam

2016-01-01

Plant tolerance to insect pests has been indicated to be a unique category of resistance, however, very little information is available on the mechanism of tolerance against insect pests. Tolerance is distinctive in terms of the plant's ability to withstand or recover from herbivore injury through growth and compensatory physiological processes. Because plant tolerance involves plant compensatory characteristics, the plant is able to harbor large numbers of herbivores without interfering with the insect pest's physiology or behavior. Some studies have observed that tolerant plants can compensate photosynthetically by avoiding feedback inhibition and impaired electron flow through photosystem II that occurs as a result of insect feeding. Similarly, the up-regulation of peroxidases and other oxidative enzymes during insect feeding, in conjunction with elevated levels of phytohormones can play an important role in providing plant tolerance to insect pests. Hemipteran insects comprise some of the most economically important plant pests (e.g., aphids, whiteflies), due to their ability to achieve high population growth and their potential to transmit plant viruses. In this review, results from studies on plant tolerance to hemipterans are summarized, and potential models to understand tolerance are presented.

Supplementing zinc oxide nanoparticles to cryopreservation medium minimizes the freeze-thaw-induced damage to spermatozoa.

PubMed

Isaac, Ann V; Kumari, Sandhya; Nair, Ramya; Urs, Deepak Raj; Salian, Sujith Raj; Kalthur, Guruprasad; Adiga, Satish Kumar; Manikkath, Jyothsna; Mutalik, Srinivas; Sachdev, Divya; Pasricha, Renu

2017-12-16

The sperm DNA integrity post cryopreservation of human semen samples is one of the serious concerns in human infertility treatment. In the present study, the beneficial effects of zinc oxide nanoparticles in preserving the functional ability of spermatozoa was explored. Ejaculates of normozoospermic men cryopreserved along with Zinc oxide nanoparticles (ZnONPs) exhibited non-significantly higher percentage of total and progressive motility in frozen-thawed samples compared to control. The sperm chromatin damage and malondialdehyde (MDA) level was significantly lower in ZnONPs group (P < 0.01 and P < 0.05 respectively) and the spermatozoa's ability to undergo acrosome reaction was also unaltered. Fluorescence microscopy and High resolution transmission electron microscopy analysis demonstrated that the ZnONPs do not penetrate the membrane of spermatozoa but stay around the spermatozoa. In conclusion, the presence of ZnONPs during cryopreservation appears to be beneficial to the spermatozoa as they withstand freeze-thaw process competently better than control, without any adverse effect shown. Copyright © 2017 Elsevier Inc. All rights reserved.

Ocean acidification narrows the acute thermal and salinity tolerance of the Sydney rock oyster Saccostrea glomerata.

PubMed

Parker, Laura M; Scanes, Elliot; O'Connor, Wayne A; Coleman, Ross A; Byrne, Maria; Pörtner, Hans-O; Ross, Pauline M

2017-09-15

Coastal and estuarine environments are characterised by acute changes in temperature and salinity. Organisms living within these environments are adapted to withstand such changes, yet near-future ocean acidification (OA) may challenge their physiological capacity to respond. We tested the impact of CO 2 -induced OA on the acute thermal and salinity tolerance, energy metabolism and acid-base regulation capacity of the oyster Saccostrea glomerata. Adult S. glomerata were acclimated to three CO 2 levels (ambient 380μatm, moderate 856μatm, high 1500μatm) for 5weeks (24°C, salinity 34.6) before being exposed to a series of acute temperature (15-33°C) and salinity (34.2-20) treatments. Oysters acclimated to elevated CO 2 showed a significant metabolic depression and extracellular acidosis with acute exposure to elevated temperature and reduced salinity, especially at the highest CO 2 of 1500μatm. Our results suggest that the acute thermal and salinity tolerance of S. glomerata and thus its distribution will reduce as OA continues to worsen. Copyright © 2017 Elsevier Ltd. All rights reserved.

Boundary Layer Transition Flight Experiment Overview and In-Situ Measurements

NASA Technical Reports Server (NTRS)

Anderson, Brian P.; Campbell, Charles H.; Saucedo, Luis A.; Kinder, Gerald R.; Berger, Karen T.

2010-01-01

In support of the Boundary Layer Transition Flight Experiment (BLTFE) Project, a manufactured protuberance tile was installed on the port wing of Space Shuttle Orbiter Discovery for the flights of STS-119 and STS-128. Additional instrumentation was also installed in order to obtain more spatially resolved measurements downstream of the protuberance. This paper provides an overview of the BLTFE Project, including the project history, organizations involved, and motivations for the flight experiment. Significant efforts were made to place the protuberance at an appropriate location on the Orbiter and to design the protuberance to withstand the expected environments. Efforts were also extended to understand the as-fabricated shape of the protuberance and the thermal protection system tile configuration surrounding the protuberance. A high-level overview of the in-situ flight data is presented, along with a summary of the comparisons between pre- and post-flight analysis predictions and flight data. Comparisons show that predictions for boundary layer transition onset time closely match the flight data, while predicted temperatures were significantly higher than observed flight temperatures.

Hardy exotics species in temperate zone: can “warm water” crayfish invaders establish regardless of low temperatures?

PubMed Central

Veselý, Lukáš; Buřič, Miloš; Kouba, Antonín

2015-01-01

The spreading of new crayfish species poses a serious risk for freshwater ecosystems; because they are omnivores they influence more than one level in the trophic chain and they represent a significant part of the benthic biomass. Both the environmental change through global warming and the expansion of the pet trade increase the possibilities of their spreading. We investigated the potential of four “warm water” highly invasive crayfish species to overwinter in the temperate zone, so as to predict whether these species pose a risk for European freshwaters. We used 15 specimens of each of the following species: the red swamp crayfish (Procambarus clarkii), the marbled crayfish (Procambarus fallax f. virginalis), the yabby (Cherax destructor), and the redclaw (Cherax quadricarinatus). Specimens were acclimatized and kept for 6.5 months at temperatures simulating the winter temperature regime of European temperate zone lentic ecosystems. We conclude that the red swamp crayfish, marbled crayfish and yabby have the ability to withstand low winter temperatures relevant for lentic habitats in the European temperate zone, making them a serious invasive threat to freshwater ecosystems. PMID:26572317

Polycrystalline CdTe detectors: A luminosity monitor for the LHC

NASA Astrophysics Data System (ADS)

Gschwendtner, E.; Placidia, M.; Schmicklera, H.

2003-09-01

The luminosity at the four interaction points of the Large Hadron Collider must be continuously monitored in order to provide an adequate tool for the control and optimization of the collision parameters and the beam optics. At both sides of the interaction points absorbers are installed to protect the super-conducting accelerator elements from quenches caused by the deposited energy of collision products. The luminosity detectors will be installed in the copper core of these absorbers to measure the electromagnetic and hadronic showers caused by neutral particles that are produced at the proton-proton collision in the interaction points. The detectors have to withstand extreme radiation levels (108 Gy/yr at the design luminosity) and their long-term operation has to be assured without requiring human intervention. In addition the demand for bunch-by-bunch luminosity measurements, i.e. 40 MHz detection speed, puts severe constraints on the detectors. Polycrystalline CdTe detectors have a high potential to fulfill the requirements and are considered as LHC luminosity monitors. In this paper the interaction region is shown and the characteristics of the CdTe detectors are presented.

A Network Access Control Framework for 6LoWPAN Networks

PubMed Central

Oliveira, Luís M. L.; Rodrigues, Joel J. P. C.; de Sousa, Amaro F.; Lloret, Jaime

2013-01-01

Low power over wireless personal area networks (LoWPAN), in particular wireless sensor networks, represent an emerging technology with high potential to be employed in critical situations like security surveillance, battlefields, smart-grids, and in e-health applications. The support of security services in LoWPAN is considered a challenge. First, this type of networks is usually deployed in unattended environments, making them vulnerable to security attacks. Second, the constraints inherent to LoWPAN, such as scarce resources and limited battery capacity, impose a careful planning on how and where the security services should be deployed. Besides protecting the network from some well-known threats, it is important that security mechanisms be able to withstand attacks that have not been identified before. One way of reaching this goal is to control, at the network access level, which nodes can be attached to the network and to enforce their security compliance. This paper presents a network access security framework that can be used to control the nodes that have access to the network, based on administrative approval, and to enforce security compliance to the authorized nodes. PMID:23334610

Application of N-Doped Three-Dimensional Reduced Graphene Oxide Aerogel to Thin Film Loudspeaker.

PubMed

Kim, Choong Sun; Lee, Kyung Eun; Lee, Jung-Min; Kim, Sang Ouk; Cho, Byung Jin; Choi, Jung-Woo

2016-08-31

We built a thermoacoustic loudspeaker employing N-doped three-dimensional reduced graphene oxide aerogel (N-rGOA) based on a simple template-free fabrication method. A two-step fabrication process, which includes freeze-drying and reduction/doping, was used to realize a three-dimensional, freestanding, and porous graphene-based loudspeaker, whose macroscopic structure can be easily modulated. The simplified fabrication process also allows the control of structural properties of the N-rGOAs, including density and area. Taking advantage of the facile fabrication process, we fabricated and analyzed thermoacoustic loudspeakers with different structural properties. The anlayses showed that a N-rGOA with lower density and larger area can produce a higher sound pressure level (SPL). Furthermore, the resistance of the proposed loudspeaker can be easily controlled through heteroatom doping, thereby helping to generate higher SPL per unit driving voltage. Our success in constructing an array of optimized N-rGOAs able to withstand input power as high as 40 W demonstrates that a practical thermoacoustic loudspeaker can be fabricated using the proposed mass-producible solution-based process.

Crosslinked polymer nanoparticles containing single conjugated polymer chains

NASA Astrophysics Data System (ADS)

Ponzio, Rodrigo A.; Marcato, Yésica L.; Gómez, María L.; Waiman, Carolina V.; Chesta, Carlos A.; Palacios, Rodrigo E.

2017-06-01

Conjugated polymer nanoparticles are widely used in fluorescent labeling and sensing, as they have mean radii between 5 and 100 nm, narrow size dispersion, high brightness, and are photochemically stable, allowing single particle detection with high spatial and temporal resolution. Highly crosslinked polymers formed by linking individual chains through covalent bonds yield high-strength rigid materials capable of withstanding dissolution by organic solvents. Hence, the combination of crosslinked polymers and conjugated polymers in a nanoparticulated material presents the possibility of interesting applications that require the combined properties of constituent polymers and nanosized dimension. In the present work, F8BT@pEGDMA nanoparticles composed of poly(ethylene glycol dimethacrylate) (pEGDMA; a crosslinked polymer) and containing the commercial conjugated polymer poly(9,9-dioctylfluorene-alt-benzothiadiazole) (F8BT) were synthesized and characterized. Microemulsion polymerization was applied to produce F8BT@pEDGMA particles with nanosized dimensions in a ∼25% yield. Photophysical and size distribution properties of F8BT@pEDGMA nanoparticles were evaluated by various methods, in particular single particle fluorescence microscopy techniques. The results demonstrate that the crosslinking/polymerization process imparts structural rigidity to the F8BT@pEDGMA particles by providing resistance against dissolution/disintegration in organic solvents. The synthesized fluorescent crosslinked nanoparticles contain (for the most part) single F8BT chains and can be detected at the single particle level, using fluorescence microscopy, which bodes well for their potential application as molecularly imprinted polymer fluorescent nanosensors with high spatial and temporal resolution.

Highly Stretchable Fully-Printed CNT-Based Electrochemical Sensors and Biofuel Cells: Combining Intrinsic and Design-Induced Stretchability.

PubMed

Bandodkar, Amay J; Jeerapan, Itthipon; You, Jung-Min; Nuñez-Flores, Rogelio; Wang, Joseph

2016-01-13

We present the first example of an all-printed, inexpensive, highly stretchable CNT-based electrochemical sensor and biofuel cell array. The synergistic effect of utilizing specially tailored screen printable stretchable inks that combine the attractive electrical and mechanical properties of CNTs with the elastomeric properties of polyurethane as a binder along with a judiciously designed free-standing serpentine pattern enables the printed device to possess two degrees of stretchability. Owing to these synergistic design and nanomaterial-based ink effects, the device withstands extremely large levels of strains (up to 500% strain) with negligible effect on its structural integrity and performance. This represents the highest stretchability offered by a printed device reported to date. Extensive electrochemical characterization of the printed device reveal that repeated stretching, torsional twisting, and indenting stress has negligible impact on its electrochemical properties. The wide-range applicability of this platform to realize highly stretchable CNT-based electrochemical sensors and biofuel cells has been demonstrated by fabricating and characterizing potentiometric ammonium sensor, amperometric enzyme-based glucose sensor, enzymatic glucose biofuel cell, and self-powered biosensor. Highly stretchable printable multianalyte sensor, multifuel biofuel cell, or any combination thereof can thus be realized using the printed CNT array. Such combination of intrinsically stretchable printed nanomaterial-based electrodes and strain-enduring design patterns holds considerable promise for creating an attractive class of inexpensive multifunctional, highly stretchable printed devices that satisfy the requirements of diverse healthcare and energy fields wherein resilience toward extreme mechanical deformations is mandatory.

Investigation of nickel hydrogen battery technology for the RADARSAT spacecraft

NASA Technical Reports Server (NTRS)

Mccoy, D. A.; Lackner, J. L.

1986-01-01

The low Earth orbit (LEO) operations of the RADARSAT spacecraft require high performance batteries to provide energy to the payload and platform during eclipse period. Nickel Hydrogen cells are currently competing with the more traditional Nickel Cadmium cells for high performance spacecraft applications at geostationary Earth orbit (GEO) and Leo. Nickel Hydrogen cells appear better suited for high power applications where high currents and high Depths of Discharge are required. Although a number of GEO missions have flown with Nickel Hydrogen batteries, it is not readily apparent that the LEO version of the Nickel Hydrogen cell is able to withstand the extended cycle lifetime (5 years) of the RADARSAT mission. The problems associated with Nickel Hydrogen cells are discussed in the contex of RADARSAT mission and a test program designed to characterize cell performance is presented.

Stiff, Thermally Stable and Highly Anisotropic Wood-Derived Carbon Composite Monoliths for Electromagnetic Interference Shielding.

PubMed

Yuan, Ye; Sun, Xianxian; Yang, Minglong; Xu, Fan; Lin, Zaishan; Zhao, Xu; Ding, Yujie; Li, Jianjun; Yin, Weilong; Peng, Qingyu; He, Xiaodong; Li, Yibin

2017-06-28

Electromagnetic interference (EMI) shielding materials for electronic devices in aviation and aerospace not only need lightweight and high shielding effectiveness, but also should withstand harsh environments. Traditional EMI shielding materials often show heavy weight, poor thermal stability, short lifetime, poor tolerance to chemicals, and are hard-to-manufacture. Searching for high-efficiency EMI shielding materials overcoming the above weaknesses is still a great challenge. Herein, inspired by the unique structure of natural wood, lightweight and highly anisotropic wood-derived carbon composite EMI shielding materials have been prepared which possess not only high EMI shielding performance and mechanical stable characteristics, but also possess thermally stable properties, outperforming those metals, conductive polymers, and their composites. The newly developed low-cost materials are promising for specific applications in aerospace electronic devices, especially regarding extreme temperatures.

Flexible radiator thermal vacuum test report

NASA Technical Reports Server (NTRS)

Oren, J. A.; Hixon, C. W.

1982-01-01

Two flexible, deployable/retraction radiators were designed and fabricated. The two radiator panels are distinguishable by their mission life design. One panel is designed with a 90 percent probability of withstanding the micrometeoroid environment of a low earth orbit for 30 days. This panel is designated the soft tube radiator after the PFA Teflon tubes which distribute the transport fluid over the panel. The second panel is designed with armored flow tubes to withstand the same micrometeoroid environment for 5 years. It is designated the hard tube radiator after its stainless steel flow tubes. The thermal performance of the radiators was tested under anticipated environmental conditions. The two deployment systems of the radiators were evaluated in a thermal vacuum environment.

Ballistic and Cyclic Rig Testing of Braided Composite Fan Case Structures

NASA Technical Reports Server (NTRS)

Watson, William R.; Roberts, Gary D.; Pereira, J. Michael; Braley, Michael S.

2015-01-01

FAA fan blade-out certification testing on turbofan engines occurs very late in an engine's development program and is very costly. It is of utmost importance to approach the FAA Certification engine test with a high degree of confidence that the containment structure will not only contain the high-energy debris, but that it will also withstand the cyclic loads that occur with engine spooldown and continued rotation as the non-running engine maintains a low rotor RPM due to forced airflow as the engine-out aircraft returns to an airport. Accurate rig testing is needed for predicting and understanding material behavior of the fan case structure during all phases of this fan blade-out event.

Accelerations in Flight

NASA Technical Reports Server (NTRS)

Doolittle, J H

1925-01-01

This work on accelerometry was done at McCook Field for the purpose of continuing the work done by other investigators and obtaining the accelerations which occur when a high-speed pursuit airplane is subjected to the more common maneuvers. The accelerations obtained in suddenly pulling out of a dive with well-balanced elevators are shown to be within 3 or 4 per cent of the theoretically possible accelerations. The maximum acceleration which a pilot can withstand depends upon the length of time the acceleration is continued. It is shown that he experiences no difficulty under the instantaneous accelerations as high as 7.8 G., but when under accelerations in excess of 4.5 G., continued for several seconds, he quickly loses his faculties.

Atomic bonding effects in annular dark field scanning transmission electron microscopy. II. Experiments

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

Odlyzko, Michael L.; Held, Jacob T.; Mkhoyan, K. Andre, E-mail: mkhoyan@umn.edu

2016-07-15

Quantitatively calibrated annular dark field scanning transmission electron microscopy (ADF-STEM) imaging experiments were compared to frozen phonon multislice simulations adapted to include chemical bonding effects. Having carefully matched simulation parameters to experimental conditions, a depth-dependent bonding effect was observed for high-angle ADF-STEM imaging of aluminum nitride. This result is explained by computational predictions, systematically examined in the preceding portion of this study, showing the propagation of the converged STEM beam to be highly sensitive to net interatomic charge transfer. Thus, although uncertainties in experimental conditions and simulation accuracy remain, the computationally predicted experimental bonding effect withstands the experimental testing reportedmore » here.« less

Influencing Factors and Workpiece's Microstructure in Laser-Assisted Milling of Titanium

NASA Astrophysics Data System (ADS)

Wiedenmann, R.; Liebl, S.; Zaeh, M. F.

Today's lightweight components have to withstand increasing mechanical and thermal loads. Therefore, advanced materials substitute conventional materials like steel or aluminum alloys. Using these high-performance materials the associated costs become prohibitively high. This paper presents the newest fundamental investigations on the hybrid process 'laser-assisted milling' which is an innovative technique to process such materials. The focus is on the validation of a numerical database for a CAD/CAM process control unit which is calculated by using simulation. Prior to that, the influencing factors on a laser-assisted milling process are systematically investigated using Design of Experiments (DoE) to identify the main influencing parameters coming from the laser and the milling operation.

Modelling structural and plasma facing materials for fusion power plants: Recent advances and outstanding issues in the EURATOM fusion materials programme

NASA Astrophysics Data System (ADS)

Boutard, Jean-Louis; Dudarev, Sergei; Rieth, Michael

2011-10-01

EFDA Fusion Materials Topical Group was established at the end of 2007 to coordinate the EU effort on the development of structural and protection materials able to withstand the very demanding operating conditions of a future DEMO power plant. Focusing on a selection of well identified materials issues, including the behaviour of Reduced Activation Ferritic-Martensitic steels, and W-alloys under the foreseen operation conditions in a future DEMO, this paper describes recent advances in physical modelling and experimental validation, contributing to the definition of chemical composition and microstructure of materials with improved in-service stability at high temperature, high neutron flux and intense ion bombardment.

Ultra high vacuum heating and rotating specimen stage

DOEpatents

Coombs, III, Arthur W.

1995-01-01

A heating and rotating specimen stage provides for simultaneous specimen heating and rotating. The stage is ideally suited for operation in ultrahigh vacuum (1.times.10.sup.-9 torr or less), but is useful at atmosphere and in pressurized systems as well. A specimen is placed on a specimen holder that is attached to a heater that, in turn, is attached to a top housing. The top housing is rotated relative to a bottom housing and electrically connected thereto by electrically conductive brushes. This stage is made of materials that are compatible with UHV, able to withstand high temperatures, possess low outgassing rates, are gall and seize resistant, and are able to carry substantial electrical loading without overheating.

Arabidopsis Glutathione Transferases U24 and U25 Exhibit a Range of Detoxification Activities with the Environmental Pollutant and Explosive, 2,4,6-Trinitrotoluene1[C][W][OPEN

PubMed Central

Gunning, Vanda; Tzafestas, Kyriakos; Sparrow, Helen; Johnston, Emily J.; Brentnall, Andrew S.; Potts, Jennifer R.; Rylott, Elizabeth L.; Bruce, Neil C.

2014-01-01

The explosive 2,4,6-trinitrotoluene (TNT) is a major worldwide military pollutant. The presence of this toxic and highly persistent pollutant, particularly at military sites and former manufacturing facilities, presents various health and environmental concerns. Due to the chemically resistant structure of TNT, it has proven to be highly recalcitrant to biodegradation in the environment. Here, we demonstrate the importance of two glutathione transferases (GSTs), GST-U24 and GST-U25, from Arabidopsis (Arabidopsis thaliana) that are specifically up-regulated in response to TNT exposure. To assess the role of GST-U24 and GST-U25, we purified and characterized recombinant forms of both enzymes and demonstrated the formation of three TNT glutathionyl products. Importantly, GST-U25 catalyzed the denitration of TNT to form 2-glutathionyl-4,6-dinitrotoluene, a product that is likely to be more amenable to subsequent biodegradation in the environment. Despite the presence of this biochemical detoxification pathway in plants, physiological concentrations of GST-U24 and GST-U25 result in only a limited innate ability to cope with the levels of TNT found at contaminated sites. We demonstrate that Arabidopsis plants overexpressing GST-U24 and GST-U25 exhibit significantly enhanced ability to withstand and detoxify TNT, properties that could be applied for in planta detoxification of TNT in the field. The overexpressing lines removed significantly more TNT from soil and exhibited a corresponding reduction in glutathione levels when compared with wild-type plants. However, in the absence of TNT, overexpression of these GSTs reduces root and shoot biomass, and although glutathione levels are not affected, this effect has implications for xenobiotic detoxification. PMID:24733884

Intraspecific Variation in Physiological Condition of Reef-Building Corals Associated with Differential Levels of Chronic Disturbance

PubMed Central

Pisapia, Chiara; Anderson, Kristen; Pratchett, Morgan S.

2014-01-01

Even in the absence of major disturbances (e.g., cyclones, bleaching), corals are subject to high levels of partial or whole-colony mortality, often caused by chronic and small-scale disturbances. Depending on levels of background mortality, these chronic disturbances may undermine individual fitness and have significant consequences on the ability of colonies to withstand subsequent acute disturbances or environmental change. This study quantified intraspecific variations in physiological condition (measured based on total lipid content and zooxanthellae density) through time in adult colonies of two common and widespread coral species (Acropora spathulata and Pocillopora damicornis), subject to different levels of biological and physical disturbances along the most disturbed reef habitat, the crest. Marked intraspecific variation in the physiological condition of A. spathulata was clearly linked to differences in local disturbance regimes and habitat. Specifically, zooxanthellae density decreased (r2 = 26, df = 5,42, p<0.02, B =  −121255, p = 0.03) and total lipid content increased (r2 = 14, df = 5,42, p = 0.01, B = 0.9, p = 0.01) with increasing distance from exposed crests. Moreover, zooxanthellae density was strongly and negatively correlated with the individual level of partial mortality (r2 = 26, df = 5,42, p<0.02, B =  −7386077, p = 0.01). Conversely, P. damicornis exhibited very limited intraspecific variation in physiological condition, despite marked differences in levels of partial mortality. This is the first study to relate intraspecific variation in the condition of corals to localized differences in chronic disturbance regimes. The next step is to ascertain whether these differences have further ramifications for susceptibility to periodic acute disturbances, such as climate-induced coral bleaching. PMID:24626395

Intraspecific variation in physiological condition of reef-building corals associated with differential levels of chronic disturbance.

PubMed

Pisapia, Chiara; Anderson, Kristen; Pratchett, Morgan S

2014-01-01

Even in the absence of major disturbances (e.g., cyclones, bleaching), corals are subject to high levels of partial or whole-colony mortality, often caused by chronic and small-scale disturbances. Depending on levels of background mortality, these chronic disturbances may undermine individual fitness and have significant consequences on the ability of colonies to withstand subsequent acute disturbances or environmental change. This study quantified intraspecific variations in physiological condition (measured based on total lipid content and zooxanthellae density) through time in adult colonies of two common and widespread coral species (Acropora spathulata and Pocillopora damicornis), subject to different levels of biological and physical disturbances along the most disturbed reef habitat, the crest. Marked intraspecific variation in the physiological condition of A. spathulata was clearly linked to differences in local disturbance regimes and habitat. Specifically, zooxanthellae density decreased (r2 = 26, df = 5,42, p<0.02, B =  -121255, p = 0.03) and total lipid content increased (r2 = 14, df = 5,42, p = 0.01, B = 0.9, p = 0.01) with increasing distance from exposed crests. Moreover, zooxanthellae density was strongly and negatively correlated with the individual level of partial mortality (r2 = 26, df = 5,42, p<0.02, B =  -7386077, p = 0.01). Conversely, P. damicornis exhibited very limited intraspecific variation in physiological condition, despite marked differences in levels of partial mortality. This is the first study to relate intraspecific variation in the condition of corals to localized differences in chronic disturbance regimes. The next step is to ascertain whether these differences have further ramifications for susceptibility to periodic acute disturbances, such as climate-induced coral bleaching.

[Improving pre- and perioperative hospital care : Major elective surgery].

PubMed

Punt, Ilona M; van der Most, Roel; Bongers, Bart C; Didden, Anouk; Hulzebos, Erik H J; Dronkers, Jaap J; van Meeteren, Nico L U

2017-04-01

Surgery is aimed at improving a patient's health. However, surgery is plagued with a risk of negative consequences, such as perioperative complications and prolonged hospitalization. Also, achieving preoperative levels of physical functionality may be delayed. Above all, the "waiting" period before the operation and the period of hospitalisation endanger the state of health, especially in frail patients.The Better in Better out™ (BiBo™) strategy is aimed at reducing the risk of a complicated postoperative course through the optimisation and professionalisation of perioperative treatment strategies in a physiotherapy activating context. BiBo™ includes four steps towards optimising personalised health care in patients scheduled for elective surgery: 1) preoperative risk assessment, 2) preoperative patient education, 3) preoperative exercise therapy for high-risk patients (prehabilitation) and 4) postoperative mobilisation and functional exercise therapy.Preoperative screening is aimed at identifying frail, high-risk patients at an early stage, and advising these high-risk patients to participate in outpatient exercise training (prehabilitation) as soon as possible. By improving preoperative physical fitness, a patient is able to better withstand the impact of major surgery and this will lead to both a reduced risk of negative side effects and better short-term outcomes as a result. Besides prehabilitation, treatment culture and infrastructure should be inherently changing in such a way that patients stay as active as they can, socially, mentally and physically after discharge.

Multilevel robustness

NASA Astrophysics Data System (ADS)

Girard, Henri-Louis; Khan, Sami; Varanasi, Kripa K.

2018-03-01

A combination of hard, soft and nanoscale organic components results in robust superhydrophobic surfaces that can withstand mechanical abrasion and chemical oxidation, and exhibit excellent substrate adhesion.

Evaluation of engineering plastic for rollover protective structure (ROPS) mounting.

PubMed

Comer, R S; Ayers, P D; Liu, J

2007-04-01

Agriculture has one of the highest fatality rates of any industry in America. Tractor rollovers are a significant contributor to the high death rate. Rollover protective structures (ROPS) have helped lower these high fatality rates on full-size tractors. However, a large number of older tractors still do not use ROPS due to the difficulty of designing and creating a mounting structure. To help reduce this difficulty, engineering plastics were evaluated for use in a ROPS mounting structure on older tractors. The use of engineering plastics around axle housings could provide a uniform mounting configuration as well as lower costs for aftermarket ROPS. Various plastics were examined through shear testing, scale model testing, and compressive strength testing. Once a material was chosen based upon strength and cost, full-scale testing of the plastic's strength on axle housings was conducted. Finally, a mounting structure was tested in static ROPS tests, and field upset tests were performed in accordance with SAE Standard J2194. Initial tests revealed that the ROPS mounting structure and axle housing combination had higher torsional strength with less twisting than the axle housing alone. An engineering plastic ROPS mounting structure was easily successful in withstanding the forces applied during the static longitudinal and lateral ROPS tests. Field upset testing revealed that the mounting structure could withstand the impact loads seen during actual upsets without a failure. During both static testing and field upset testing, no permanent twisting of the mounting structure was found. Engineering plastic could therefore be a viable option for a universal ROPS mounting structure for older tractors.

A new JPEG-based steganographic algorithm for mobile devices

NASA Astrophysics Data System (ADS)

Agaian, Sos S.; Cherukuri, Ravindranath C.; Schneider, Erik C.; White, Gregory B.

2006-05-01

Currently, cellular phones constitute a significant portion of the global telecommunications market. Modern cellular phones offer sophisticated features such as Internet access, on-board cameras, and expandable memory which provide these devices with excellent multimedia capabilities. Because of the high volume of cellular traffic, as well as the ability of these devices to transmit nearly all forms of data. The need for an increased level of security in wireless communications is becoming a growing concern. Steganography could provide a solution to this important problem. In this article, we present a new algorithm for JPEG-compressed images which is applicable to mobile platforms. This algorithm embeds sensitive information into quantized discrete cosine transform coefficients obtained from the cover JPEG. These coefficients are rearranged based on certain statistical properties and the inherent processing and memory constraints of mobile devices. Based on the energy variation and block characteristics of the cover image, the sensitive data is hidden by using a switching embedding technique proposed in this article. The proposed system offers high capacity while simultaneously withstanding visual and statistical attacks. Based on simulation results, the proposed method demonstrates an improved retention of first-order statistics when compared to existing JPEG-based steganographic algorithms, while maintaining a capacity which is comparable to F5 for certain cover images.

Miniature Convection Cooled Plug-type Heat Flux Gauges

NASA Technical Reports Server (NTRS)

Liebert, Curt H.

1994-01-01

Tests and analysis of a new miniature plug-type heat flux gauge configuration are described. This gauge can simultaneously measure heat flux on two opposed active surfaces when heat flux levels are equal to or greater than about 0.2 MW/m(sup 2). The performance of this dual active surface gauge was investigated over a wide transient and steady heat flux and temperature range. The tests were performed by radiatively heating the front surface with an argon arc lamp while the back surface was convection cooled with air. Accuracy is about +20 percent. The gauge is responsive to fast heat flux transients and is designed to withstand the high temperature (1300 K), high pressure (15 MPa), erosive and corrosive environments in modern engines. This gauge can be used to measure heat flux on the surfaces of internally cooled apparatus such as turbine blades and combustors used in jet propulsion systems and on the surfaces of hypersonic vehicles. Heat flux measurement accuracy is not compromised when design considerations call for various size gauges to be fabricated into alloys of various shapes and properties. Significant gauge temperature reductions (120 K), which can lead to potential gauge durability improvement, were obtained when the gauges were air-cooled by forced convection.

Ancestral genetic diversity associated with the rapid spread of stress-tolerant coral symbionts in response to Holocene climate change.

PubMed

Hume, Benjamin C C; Voolstra, Christian R; Arif, Chatchanit; D'Angelo, Cecilia; Burt, John A; Eyal, Gal; Loya, Yossi; Wiedenmann, Jörg

2016-04-19

Coral communities in the Persian/Arabian Gulf (PAG) withstand unusually high salinity levels and regular summer temperature maxima of up to ∼35 °C that kill conspecifics elsewhere. Due to the recent formation of the PAG and its subsequent shift to a hot climate, these corals have had only <6,000 y to adapt to these extreme conditions and can therefore inform on how coral reefs may respond to global warming. One key to coral survival in the world's warmest reefs are symbioses with a newly discovered alga,Symbiodinium thermophilum Currently, it is unknown whether this symbiont originated elsewhere or emerged from unexpectedly fast evolution catalyzed by the extreme environment. Analyzing genetic diversity of symbiotic algae across >5,000 km of the PAG, the Gulf of Oman, and the Red Sea coastline, we show thatS. thermophilumis a member of a highly diverse, ancient group of symbionts cryptically distributed outside the PAG. We argue that the adjustment to temperature extremes by PAG corals was facilitated by the positive selection of preadapted symbionts. Our findings suggest that maintaining the largest possible pool of potentially stress-tolerant genotypes by protecting existing biodiversity is crucial to promote rapid adaptation to present-day climate change, not only for coral reefs, but for ecosystems in general.

High-Voltage-Input Level Translator Using Standard CMOS

NASA Technical Reports Server (NTRS)

Yager, Jeremy A.; Mojarradi, Mohammad M.; Vo, Tuan A.; Blalock, Benjamin J.

2011-01-01

proposed integrated circuit would translate (1) a pair of input signals having a low differential potential and a possibly high common-mode potential into (2) a pair of output signals having the same low differential potential and a low common-mode potential. As used here, "low" and "high" refer to potentials that are, respectively, below or above the nominal supply potential (3.3 V) at which standard complementary metal oxide/semiconductor (CMOS) integrated circuits are designed to operate. The input common-mode potential could lie between 0 and 10 V; the output common-mode potential would be 2 V. This translation would make it possible to process the pair of signals by use of standard 3.3-V CMOS analog and/or mixed-signal (analog and digital) circuitry on the same integrated-circuit chip. A schematic of the circuit is shown in the figure. Standard 3.3-V CMOS circuitry cannot withstand input potentials greater than about 4 V. However, there are many applications that involve low-differential-potential, high-common-mode-potential input signal pairs and in which standard 3.3-V CMOS circuitry, which is relatively inexpensive, would be the most appropriate circuitry for performing other functions on the integrated-circuit chip that handles the high-potential input signals. Thus, there is a need to combine high-voltage input circuitry with standard low-voltage CMOS circuitry on the same integrated-circuit chip. The proposed circuit would satisfy this need. In the proposed circuit, the input signals would be coupled into both a level-shifting pair and a common-mode-sensing pair of CMOS transistors. The output of the level-shifting pair would be fed as input to a differential pair of transistors. The resulting differential current output would pass through six standoff transistors to be mirrored into an output branch by four heterojunction bipolar transistors. The mirrored differential current would be converted back to potential by a pair of diode-connected transistors, which, by virtue of being identical to the input transistors, would reproduce the input differential potential at the output

Summary Report: NMSBA CY 2016 - AEgis Technologies Group Inc. #12458.

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

Bellum, John Curtis; Field, Ella Suzanne

2016-12-01

AEgis requires large area partial mirror optics consisting of partially reflecting optical coatings on large dimension substrates for high energy laser (HEL) applications. The partial mirrors should transmit nearly the same small fraction of HEL radiation incident from a wide range of angles of incidence (AOIs), and the laser-induced damage threshold (LIDT) of the coatings should be high enough for them to be able to withstand direct exposure to near infrared CW HEL radiation at multi-kilowatt/cm2 power levels. The transmitted fraction of incident HEL radiation should reach an array of detectors at power levels high enough for reliable detection butmore » low enough to not damage the detectors. The reflected fraction of incident HEL radiation should scatter into a divergent pattern so as to be eye safe at a distance of ~ 200 m from the mirror in the case of 100 kilowatt incident laser power. The detector array together with the partial mirror optic and possible additional optics that provide divergent scattering of reflected HEL radiation constitute what AEgis refers to as a target board. The target board use environment may vary from benign, indoor laboratory conditions to harsh, outdoor conditions in tests on the ground as well as in air. Under this NMSBA project, Sandia agreed to apply its extensive expertise and capability in the design and production of high LIDT coatings on large dimension optics for high power pulsed laser radiation to advise and assist AEgis in the design and development of high LIDT coatings for the partial mirror optic. Sandia and AEgis met several times to discuss the partial mirror and target board requirements, and Sandia was guided in its work by these discussions as well as by the partial mirror and target board requirement summaries of Tables 1 and 2, respectively, that were provided by AEgis.« less

Effectiveness of multidisciplinary team case management: difference-in-differences analysis.

PubMed

Stokes, Jonathan; Kristensen, Søren Rud; Checkland, Kath; Bower, Peter

2016-04-15

To evaluate a multidisciplinary team (MDT) case management intervention, at the individual (direct effects of intervention) and practice levels (potential spillover effects). Difference-in-differences design with multiple intervention start dates, analysing hospital admissions data. In secondary analyses, we stratified individual-level results by risk score. Single clinical commissioning group (CCG) in the UK's National Health Service (NHS). At the individual level, we matched 2049 intervention patients using propensity scoring one-to-one with control patients. At the practice level, 30 practices were compared using a natural experiment through staged implementation. Practice Integrated Care Teams (PICTs), using MDT case management of high-risk patients together with a summary record of care versus usual care. Primary measures of intervention effects were accident and emergency (A&E) visits; inpatient non-elective stays, 30-day re-admissions; inpatient elective stays; outpatient visits; and admissions for ambulatory care sensitive conditions. Secondary measures included inpatient length of stay; total cost of secondary care services; and patient satisfaction (at the practice level only). At the individual level, we found slight, clinically trivial increases in inpatient non-elective admissions (+0.01 admissions per patient per month; 95% CI 0.00 to 0.01. Effect size (ES): 0.02) and 30-day re-admissions (+0.00; 0.00 to 0.01. ES: 0.03). We found no indication that highest risk patients benefitted more from the intervention. At the practice level, we found a small decrease in inpatient non-elective admissions (-0.63 admissions per 1000 patients per month; -1.17 to -0.09. ES: -0.24). However, this result did not withstand a robustness check; the estimate may have absorbed some differences in underlying practice trends. The intervention does not meet its primary aim, and the clinical significance and cost-effectiveness of these small practice-level effects is debatable. There is an ongoing need to develop effective ways to reduce unnecessary attendances in secondary care for the high-risk population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Effectiveness of multidisciplinary team case management: difference-in-differences analysis

PubMed Central

Kristensen, Søren Rud; Checkland, Kath; Bower, Peter

2016-01-01

Objectives To evaluate a multidisciplinary team (MDT) case management intervention, at the individual (direct effects of intervention) and practice levels (potential spillover effects). Design Difference-in-differences design with multiple intervention start dates, analysing hospital admissions data. In secondary analyses, we stratified individual-level results by risk score. Setting Single clinical commissioning group (CCG) in the UK's National Health Service (NHS). Participants At the individual level, we matched 2049 intervention patients using propensity scoring one-to-one with control patients. At the practice level, 30 practices were compared using a natural experiment through staged implementation. Intervention Practice Integrated Care Teams (PICTs), using MDT case management of high-risk patients together with a summary record of care versus usual care. Direct and indirect outcome measures Primary measures of intervention effects were accident and emergency (A&E) visits; inpatient non-elective stays, 30-day re-admissions; inpatient elective stays; outpatient visits; and admissions for ambulatory care sensitive conditions. Secondary measures included inpatient length of stay; total cost of secondary care services; and patient satisfaction (at the practice level only). Results At the individual level, we found slight, clinically trivial increases in inpatient non-elective admissions (+0.01 admissions per patient per month; 95% CI 0.00 to 0.01. Effect size (ES): 0.02) and 30-day re-admissions (+0.00; 0.00 to 0.01. ES: 0.03). We found no indication that highest risk patients benefitted more from the intervention. At the practice level, we found a small decrease in inpatient non-elective admissions (−0.63 admissions per 1000 patients per month; −1.17 to −0.09. ES: −0.24). However, this result did not withstand a robustness check; the estimate may have absorbed some differences in underlying practice trends. Conclusions The intervention does not meet its primary aim, and the clinical significance and cost-effectiveness of these small practice-level effects is debatable. There is an ongoing need to develop effective ways to reduce unnecessary attendances in secondary care for the high-risk population. PMID:27084278

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

Edwards, Timothy S.

Normal tolerance limits are frequently used in dynamic environments specifications of aerospace systems as a method to account for aleatory variability in the environments. Upper tolerance limits, when used in this way, are computed from records of the environment and used to enforce conservatism in the specification by describing upper extreme values the environment may take in the future. Components and systems are designed to withstand these extreme loads to ensure they do not fail under normal use conditions. The degree of conservatism in the upper tolerance limits is controlled by specifying the coverage and confidence level (usually written inmore » “coverage/confidence” form). Moreover, in high-consequence systems it is common to specify tolerance limits at 95% or 99% coverage and confidence at the 50% or 90% level. Despite the ubiquity of upper tolerance limits in the aerospace community, analysts and decision-makers frequently misinterpret their meaning. The misinterpretation extends into the standards that govern much of the acceptance and qualification of commercial and government aerospace systems. As a result, the risk of a future observation of the environment exceeding the upper tolerance limit is sometimes significantly underestimated by decision makers. This note explains the meaning of upper tolerance limits and a related measure, the upper prediction limit. So, the objective of this work is to clarify the probability of exceeding these limits in flight so that decision-makers can better understand the risk associated with exceeding design and test levels during flight and balance the cost of design and development with that of mission failure.« less

Intramuscular Electrical Stimulation for Muscle Activation of the Tibialis Anterior After Surgical Repair: A Case Report.

PubMed

Hollis, Sharon; McClure, Philip

2017-12-01

Background Loss of voluntary activation of musculature can result in muscle weakness. External neuromuscular stimulation can be utilized to improve voluntary activation but is often poorly tolerated because of pain associated with required stimulus level. Intramuscular electrical stimulation requires much lower voltage and may be better tolerated, and therefore more effective at restoring voluntary muscle activation. Case Description A 71-year-old man sustained a rupture of the distal attachment of the tibialis anterior tendon. Thirty-two weeks after surgical repair, there was no palpable or visible tension development in the muscle belly or tendon. Dorsiflexion was dependent on toe extensors. Electrical stimulation applied via a dry needling placement in the muscle belly was utilized to induce an isometric contraction. Outcomes Five sessions of intramuscular electrical stimulation were delivered. By day 4 (second visit), the patient was able to dorsiflex without prominent use of the extensor hallucis longus. By day 6 (third visit), active-range-of-motion dorsiflexion with toes flexed increased 20° (-10° to 10°). Eighteen days after the initial treatment, the patient walked without his previous high-step gait pattern, and the tibialis anterior muscle test improved to withstanding moderate resistance (manual muscle test score, 4/5). Discussion The rapid change in muscle function observed suggests that intramuscular electrical stimulation may facilitate voluntary muscle activation. Level of Evidence Therapy, level 5. J Orthop Sports Phys Ther 2017;47(12):965-969. Epub 15 Oct 2017. doi:10.2519/jospt.2017.7368.

High-temperature, high-pressure optical port for rocket engine applications

NASA Technical Reports Server (NTRS)

Delcher, Ray; Nemeth, ED; Powers, W. T.

1993-01-01

This paper discusses the design, fabrication, and test of a window assembly for instrumentation of liquid-fueled rocket engine hot gas systems. The window was designed to allow optical measurements of hot gas in the SSME fuel preburner and appears to be the first window designed for application in a rocket engine hot gas system. Such a window could allow the use of a number of remote optical measurement technologies including: Raman temperature and species concentration measurement, Raleigh temperature measurements, flame emission monitoring, flow mapping, laser-induced florescence, and hardware imaging during engine operation. The window assembly has been successfully tested to 8,000 psi at 1000 F and over 11,000 psi at room temperature. A computer stress analysis shows the window will withstand high temperature and cryogenic thermal shock.

Initiated chemical vapor deposition polymers for high peak-power laser targets

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

Baxamusa, Salmaan H.; Lepro, Xavier; Lee, Tom

2016-12-05

Here, we report two examples of initiated chemical vapor deposition (iCVD) polymers being developed for use in laser targets for high peak-power laser systems. First, we show that iCVD poly(divinylbenzene) is more photo-oxidatively stable than the plasma polymers currently used in laser targets. Thick layers (10–12 μm) of this highly crosslinked polymer can be deposited with near-zero intrinsic film stress. Second, we show that iCVD epoxy polymers can be crosslinked after deposition to form thin adhesive layers for assembling precision laser targets. The bondlines can be made as thin as ~ 1 μm, approximately a factor of 2 thinner thanmore » achievable using viscous resin-based adhesives. These bonds can withstand downstream coining and stamping processes.« less

Mechanical Properties and Real-Time Damage Evaluations of Environmental Barrier Coated SiC/SiC CMCs Subjected to Tensile Loading Under Thermal Gradients

NASA Technical Reports Server (NTRS)

Appleby, Matthew; Zhu, Dongming; Morscher, Gregory

2015-01-01

SiC/SiC ceramic matrix composites (CMCs) require new state-of-the art environmental barrier coatings (EBCs) to withstand increased temperature requirements and high velocity combustion corrosive combustion gasses. The present work compares the response of coated and uncoated SiC/SiC CMC substrates subjected to simulated engine environments followed by high temperature mechanical testing to asses retained properties and damage mechanisms. Our focus is to explore the capabilities of electrical resistance (ER) measurements as an NDE technique for testing of retained properties under combined high heat-flux and mechanical loading conditions. Furthermore, Acoustic Emission (AE) measurements and Digital Image Correlation (DIC) were performed to determine material damage onset and accumulation.

High temperature probe

DOEpatents

Swan, Raymond A.

1994-01-01

A high temperature probe for sampling, for example, smokestack fumes, and is able to withstand temperatures of 3000.degree. F. The probe is constructed so as to prevent leakage via the seal by placing the seal inside the water jacket whereby the seal is not exposed to high temperature, which destroys the seal. The sample inlet of the probe is also provided with cooling fins about the area of the seal to provide additional cooling to prevent the seal from being destroyed. Also, a heated jacket is provided for maintaining the temperature of the gas being tested as it passes through the probe. The probe includes pressure sensing means for determining the flow velocity of an efficient being sampled. In addition, thermocouples are located in various places on the probe to monitor the temperature of the gas passing there through.

Synthesis and Characterization of High-Dielectric-Constant Nanographite-Polyurethane Composite

NASA Astrophysics Data System (ADS)

Mishra, Praveen; Bhat, Badekai Ramachandra; Bhattacharya, B.; Mehra, R. M.

2018-05-01

In the face of ever-growing demand for capacitors and energy storage devices, development of high-dielectric-constant materials is of paramount importance. Among various dielectric materials available, polymer dielectrics are preferred for their good processability. We report herein synthesis and characterization of nanographite-polyurethane composite with high dielectric constant. Nanographite showed good dispersibility in the polyurethane matrix. The thermosetting nature of polyurethane gives the composite the ability to withstand higher temperature without melting. The resultant composite was studied for its dielectric constant (ɛ) as a function of frequency. The composite exhibited logarithmic variation of ɛ from 3000 at 100 Hz to 225 at 60 kHz. The material also exhibited stable dissipation factor (tan δ) across the applied frequencies, suggesting its ability to resist current leakage.

Electrical characterization of glass, teflon, and tantalum capacitors at high temperatures

NASA Technical Reports Server (NTRS)

Hammoud, A. N.; Baumann, E. D.; Myers, I. T.; Overton, E.

1991-01-01

Dielectric materials and electrical components and devices employed in radiation fields and the space environment are often exposed to elevated temperatures among other things. Therefore, these systems must withstand the high temperature exposure while still providing good electrical and other functional properties. Experiments were carried out to evaluate glass, teflon, and tantalum capacitors for potential use in high temperature applications. The capacitors were characterized in terms of their capacitance and dielectric loss as a function of temperature up to 200 C. At a given temperature, these properties were obtained in a frequency range of 50 Hz to 100 kHz. The DC leakage current measurements were also performed in a temperature range from 20 to 200 C. The obtained results are discussed and conclusions are made concerning the suitability of the capacitors investigated for high temperature applications.

KENNEDY SPACE CENTER, FLA. - Dan Phillips (left) and Donald Nielen, with United Space Alliance, watch a monitor as Jim Landy, NDE specialist with USA, prepares to examine a Reinforced Carbon Carbon panel (on the table, center) using flash thermography. A relatively new procedure at KSC, thermography uses high intensity light to heat areas of the panels. The panels are then immediately scanned with an infrared camera. As the panels cool, any internal flaws are revealed. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters. They have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry. The panels will be installed on the orbiter Discovery, designated for the first Return to Flight mission, STS-114.

NASA Image and Video Library

2004-03-10

KENNEDY SPACE CENTER, FLA. - Dan Phillips (left) and Donald Nielen, with United Space Alliance, watch a monitor as Jim Landy, NDE specialist with USA, prepares to examine a Reinforced Carbon Carbon panel (on the table, center) using flash thermography. A relatively new procedure at KSC, thermography uses high intensity light to heat areas of the panels. The panels are then immediately scanned with an infrared camera. As the panels cool, any internal flaws are revealed. The gray carbon composite RCC panels are attached to the leading edge of the wing of the orbiters. They have sufficient strength to withstand the aerodynamic forces experienced during launch and reentry, which can reach as high as 800 pounds per square foot. The operating range of RCC is from minus 250º F to about 3,000º F, the temperature produced by friction with the atmosphere during reentry. The panels will be installed on the orbiter Discovery, designated for the first Return to Flight mission, STS-114.

Improving Thermomechanical Properties of SiC/SiC Composites

NASA Technical Reports Server (NTRS)

DiCarlo, James A.; Bhatt, Ramakrishna T.

2006-01-01

Today, a major thrust toward improving the thermomechanical properties of engine components lies in the development of fiber-reinforced silicon carbide matrix composite materials, including SiC-fiber/SiC-matrix composites. These materials are lighter in weight and capable of withstanding higher temperatures, relative to state-of-the-art metallic alloys and oxide-matrix composites for which maximum use temperatures are in the vicinity of 1,100 C. In addition, the toughness or damage tolerance of the SiC-matrix composites is significantly greater than that of unreinforced silicon-based monolithic ceramics. For successful application in advanced engine systems, the SiC-matrix composites should be able to withstand component service stresses and temperatures for the desired component lifetimes. Inasmuch as the high-temperature structural lives of ceramic materials are typically limited by creep-induced growth of flaws, a key property required of such composite materials is high resistance to creep under conditions of use. Also, the thermal conductivity of the materials should be as high as possible so as to minimize component thermal gradients and thermal stresses. A state-of-the-art SiC-matrix composite is typically fabricated in a three-step process: (1) fabrication of a component-shaped architectural preform reinforced by thermally stable high-performance fibers, (2) chemical-vapor infiltration (CVI) of a fiber-coating material such as boron nitride (BN) into the preform, and (3) infiltration of an SiC-based matrix into the remaining porosity in the preform. Generally, the matrices of the highest-performing composites are fabricated by initial use of a CVI SiC matrix component that is typically more thermally stable and denser than matrix components formed by processes other than CVI. As such, the initial SiC matrix component made by CVI provides better environmental protection to the coated fibers embedded within it. Also, the denser CVI SiC imparts to the composite better resistance to propagation of cracks, enhanced thermal conductivity, and higher creep resistance.

Identification and characterization of a mesophilic phytase highly resilient to high-temperatures from a fungus-garden associated metagenome.

PubMed

Tan, Hao; Wu, Xiang; Xie, Liyuan; Huang, Zhongqian; Peng, Weihong; Gan, Bingcheng

2016-03-01

Phytases are enzymes degrading phytic acid and thereby releasing inorganic phosphate. While the phytases reported to date are majorly from culturable microorganisms, the fast-growing quantity of publicly available metagenomic data generated in the last decade has enabled bioinformatic mining of phytases in numerous data mines derived from a variety of ecosystems throughout the world. In this study, we are interested in the histidine acid phosphatase (HAP) family phytases present in insect-cultivated fungus gardens. Using bioinformatic approaches, 11 putative HAP phytase genes were initially screened from 18 publicly available metagenomes of fungus gardens and were further overexpressed in Escherichia coli. One phytase from a south pine beetle fungus garden showed the highest activity and was then chosen for further study. Biochemical characterization showed that the phytase is mesophilic but possesses strong ability to withstand high temperatures. To our knowledge, it has the longest half-life time at 100 °C (27 min) and at 80 °C (2.1 h) as compared to all the thermostable phytases publicly reported to date. After 100 °C incubation for 15 min, more than 93 % of the activity was retained. The activity was 3102 μmol P/min/mg at 37 °C and 4135 μmol P/min/mg at 52.5 °C, which is higher than all the known thermostable phytases. For the high activity level demonstrated at mesophilic temperatures as well as the high resilience to high temperatures, the phytase might be promising for potential application as an additive enzyme in animal feed.

Structural weights analysis of advanced aerospace vehicles using finite element analysis

NASA Technical Reports Server (NTRS)

Bush, Lance B.; Lentz, Christopher A.; Rehder, John J.; Naftel, J. Chris; Cerro, Jeffrey A.

1989-01-01

A conceptual/preliminary level structural design system has been developed for structural integrity analysis and weight estimation of advanced space transportation vehicles. The system includes a three-dimensional interactive geometry modeler, a finite element pre- and post-processor, a finite element analyzer, and a structural sizing program. Inputs to the system include the geometry, surface temperature, material constants, construction methods, and aerodynamic and inertial loads. The results are a sized vehicle structure capable of withstanding the static loads incurred during assembly, transportation, operations, and missions, and a corresponding structural weight. An analysis of the Space Shuttle external tank is included in this paper as a validation and benchmark case of the system.

Shelter from the Storm.

ERIC Educational Resources Information Center

Urbaniak, Al; Farber, Yuriy

2002-01-01

Discusses how door manufacturers are introducing products designed to pass the rigorous tests needed to withstand tornadoes, including the Federal Emergency Management Agency's 320 and 361 directives. (EV)

Electrodynamic Dust Shield Technology for Thermal Radiators Used in Lunar Exploration

NASA Technical Reports Server (NTRS)

Calle, Carlos I.; Hogue, Michael D.; Snyder, Sarah J.; Clements, Sidney J.; Johansen, Michael R.; Chen, Albert

2011-01-01

Two general types of thermal radiators are being considered for lunar missions: coated metallic surfaces and Second Surface Mirrors. Metallic surfaces are coated with a specially formulated white paint that withstands the space environment and adheres well to aluminium, the most common metal used in space hardware. AZ-93 White Thermal Control Paint, developed for the space program, is an electrically conductive inorganic coating that offers thermal control for spacecraft. It is currently in use on satellite surfaces (Fig 1). This paint withstands exposure to atomic oxygen, charged particle radiation, and vacuum ultraviolet radiation form 118 nm to 170 nm while reflecting 84 to 85% of the incident solar radiation and emitting 89-93% of the internal heat generated inside the spacecraft.

Biomechanics: no force limit on greyhound sprint speed.

PubMed

Usherwood, James R; Wilson, Alan M

2005-12-08

Maximum running speed is constrained by the speed at which the limbs can be swung forwards and backwards, and by the force they can withstand while in contact with the ground. Humans sprinting around banked bends change the duration of foot contact to spread the time over which the load is applied, thereby keeping the force on their legs constant. We show here that, on entering a tight bend, greyhounds do not change their foot-contact timings, and so have to withstand a 65% increase in limb forces. This supports the idea that greyhounds power locomotion by torque about the hips, so--just as in cycling humans--the muscles that provide the power are mechanically divorced from the structures that support weight.

Beam heating of thick targets for on-line mass separators

NASA Astrophysics Data System (ADS)

Eaton, T. W.; Ravn, H. L.; Isolde Collaboration

1987-05-01

Energy deposition computations have been made on a variety of target materials utilized for the production of radioisotopes by means of 600-MeV protons. Results have shown that, when a proton current of 100 μA is assumed, dispersed target materials, such as uranium carbide powder and magnesium oxide, are best able to withstand the energy absorption and consequent beam heating without the need of additional cooling. Modified foil targets of titanium, zirconium and tantalum also appear capable of withstanding a full beam current, whilst liquid metal targets in their present form appear to have limitations in terms of the maximum allowable beam current. A redesign of the target container is proposed which allows higher proton currents to be used with these targets also.