Recovery of cesium

DOEpatents

Izatt, Reed M.; Christensen, James J.; Hawkins, Richard T.

1984-01-01

A process of recovering cesium ions from mixtures of ions containing them and other ions, e.g., a solution of nuclear waste materials, which comprises establishing a separate source phase containing such a mixture of ions, establishing a separate recipient phase, establishing a liquid membrane phase in interfacial contact with said source and recipient phases, said membrane phase containing a ligand, preferably a selected calixarene as depicted in the drawing, maintaining said interfacial contact for a period of time long enough to transport by said ligand a substantial portion of the cesium ion from the source phase to the recipient phase, and recovering the cesium ion from the recipient phase. The separation of the source and recipient phases may be by the membrane phase only, e.g., where these aqueous phases are emulsified as dispersed phases in a continuous membrane phase, or may include a physical barrier as well, e.g., an open-top outer container with an inner open-ended container of smaller cross-section mounted in the outer container with its open bottom end spaced from and above the closed bottom of the outer container so that the membrane phase may fill the outer container to a level above the bottom of the inner container and have floating on its upper surface a source phase and a recipient phase separated by the wall of the inner container as a physical barrier. A preferred solvent for the ligand is a mixture of methylene chloride and carbon tetrachloride.

Plasma treatment of polyethylene tubes in continuous regime using surface dielectric barrier discharge with water electrodes

NASA Astrophysics Data System (ADS)

Galmiz, Oleksandr; Zemánek, Miroslav; Pavliňák, David; Černák, Mirko

2018-05-01

Combining the surface dielectric barrier discharges generated in contact with water based electrolytes, as the discharge electrodes, we have designed a new type of surface electric discharge, generating thin layers of plasma which propagate along the treated polymer surfaces. The technique was aimed to achieve uniform atmospheric pressure plasma treatment of polymeric tubes and other hollow bodies. The results presented in this work show the possibility of such system to treat outer surface of polymer materials in a continuous mode. The technical details of experimental setup are discussed as well as results of treatment of polyethylene tubes are shown.

Multilayer Composite Pressure Vessels

NASA Technical Reports Server (NTRS)

DeLay, Tom

2005-01-01

A method has been devised to enable the fabrication of lightweight pressure vessels from multilayer composite materials. This method is related to, but not the same as, the method described in gMaking a Metal- Lined Composite-Overwrapped Pressure Vessel h (MFS-31814), NASA Tech Briefs, Vol. 29, No. 3 (March 2005), page 59. The method is flexible in that it poses no major impediment to changes in tank design and is applicable to a wide range of tank sizes. The figure depicts a finished tank fabricated by this method, showing layers added at various stages of the fabrication process. In the first step of the process, a mandrel that defines the size and shape of the interior of the tank is machined from a polyurethane foam or other suitable lightweight tooling material. The mandrel is outfitted with metallic end fittings on a shaft. Each end fitting includes an outer flange that has a small step to accommodate a thin layer of graphite/epoxy or other suitable composite material. The outer surface of the mandrel (but not the fittings) is covered with a suitable release material. The composite material is filament- wound so as to cover the entire surface of the mandrel from the step on one end fitting to the step on the other end fitting. The composite material is then cured in place. The entire workpiece is cut in half in a plane perpendicular to the axis of symmetry at its mid-length point, yielding two composite-material half shells, each containing half of the foam mandrel. The halves of the mandrel are removed from within the composite shells, then the shells are reassembled and bonded together with a belly band of cured composite material. The resulting composite shell becomes a mandrel for the subsequent steps of the fabrication process and remains inside the final tank. The outer surface of the composite shell is covered with a layer of material designed to be impermeable by the pressurized fluid to be contained in the tank. A second step on the outer flange of each end fitting accommodates this layer. Depending on the application, this layer could be, for example, a layer of rubber, a polymer film, or an electrodeposited layer of metal. If the fluid to be contained in the tank is a gas, then the best permeation barrier is electrodeposited metal (typically copper or nickel), which can be effective at a thickness of as little as 0.005 in (.0.13 mm). The electrodeposited metal becomes molecularly bonded to the second step on each metallic end fitting. The permeation-barrier layer is covered with many layers of filament-wound composite material, which could be the same as, or different from, the composite material of the inner shell. Finally, the filament-wound composite material is cured in an ov

Modeling Holocene Barrier Island Morphodynamics and Potential Future Response to Sea- Level Rise, Outer Banks, North Carolina

NASA Astrophysics Data System (ADS)

Moore, L. J.; List, J. H.; Williams, S. J.; Stolper, D.

2006-12-01

A morphological-behavior model, GEOMBEST, which simulates the evolution of coastal morphology and stratigraphy resulting from changes in sea level and sediment supply provides insight into how barriers evolve over time scales ranging from decades to millenia. The model is based upon behavior rules originating from "Bruun rule" concepts, with additional parameters to allow simulation of more complex real-world scenarios. Morphological evolution in the model is driven by disequilibrium between the shoreface and a user-specified theoretical equilibrium profile that maintains its vertical position relative to sea level. As sea level continues rising to an estimated 48 cm above current MSL by AD 2100 (IPCC 2001) and hurricanes of potentially greater intensity impact the coast, barrier islands will respond either by transgressing across underlying strata or by disintegrating and ultimately submerging. Recent studies suggest that some barriers along the U.S. East Coast will break up and become submerged within decades. Other studies show that barriers in Louisiana have already submerged while others are in the process of narrowing in place and submerging. Several factors determine barrier island response to sea-level rise. These include initial topography and morphology of the barrier, underlying geologic framework, availability and supply of sediment, rate of sea-level rise, frequency and intensity of coastal storms, and anthropogenic modifications to the coast. Sensitivity analyses conducted in GEOMBEST suggest that of these factors, barrier-island response is most sensitive to the rate of sea-level rise. The Holocene evolution of the Outer Banks and potential future responses to sea-level rise are explored for a 25-km stretch of coast between Rodanthe and Cape Hatteras, NC using GEOMBEST. An 8500-year hindcast simulation for the study area reproduces closely the morphology and stratigraphy of the modern barrier with approximately 5 x 109 m3 excavated from the Pleistocene substrate, liberating a volume of material sufficient to construct Diamond Shoals. This hindcast simulation serves as the basis for forward simulations of potential future barrier island evolution. A series of model runs based on the low- (0.09 m), mid- (0.48 m) and upper- (0.88 m) range of IPCC (2001) estimates for sea-level rise by the year 2100, suggest the barrier would migrate at rates of approximately 2, 6 and 10 m/yr, respectively. The latter two results would represent an increase over modern long-term erosion rates in the study area, which serve as a proxy for migration rates. Model simulations of barrier response to 4 and 6 m of sea-level rise by AD 2100 (Overpeck et al., 2006), result in model-generated migration rates of 43 and 68 m/yr, respectively. These rates far exceed the highest average long-term barrier island erosion rates observed today along the Louisiana Coast where the Chandeleur Islands disintegrated in response to Hurricane Katrina. If observations in Louisiana can be applied to barrier islands in North Carolina, then we can expect the Outer Banks to become vulnerable to disintegration when migration rates reach approximately 15-20 m/yr. The five forward simulations for the study area suggest rates in this range may be achieved in the Outer Banks if sea-level rise by AD 2100 exceeds IPCC (2001) estimates.

Modeling barrier island response to sea-level rise in the Outer Banks, North Carolina

USGS Publications Warehouse

Moore, Laura J.; List, Jeffrey H.; Williams, S. Jeffress; Stolper, David

2007-01-01

An 8500-year Holocene simulation developed in GEOMBEST provides a possible scenario to explain the evolution of barrier coast between Rodanthe and Cape Hatteras, NC. Sensitivity analyses suggest that in the Outer Banks, the rate of sea-level rise is the most important factor in determining how barrier islands evolve. The Holocene simulation provides a basis for future simulations, which suggest that if sea level rises up to 0.88 m by AD 2100, as predicted by the highest estimates of the Intergovernmental Panel on Climate Change, the barrier in the study area may migrate on the order of 2.5 times more rapidly than at present. If sea level rises beyond IPCC predictions to reach 1.4–1.9 m above modern sea level by AD 2100, model results suggest that barrier islands in the Outer Banks may become vulnerable to threshold collapse, disintegrating during storm events, by the end of the next century. Consistent with sensitivity analyses, additional simulations indicate that anthropogenic activities, such as increasing the rate of sediment supply through beach nourishment, will only slightly affect barrier island migration rates and barrier island vulnerability to collapse.

A radio frequency coaxial feedthrough

DOEpatents

Owens, T.L.

1987-12-07

An improved radio frequency coaxial transmission line vacuum feedthrough is provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflection from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits the voltage and power handling capabilities of a feedthrough.

Radio frequency coaxial feedthrough

DOEpatents

Owens, Thomas L.

1989-01-17

An improved radio frequency coaxial transmission line vacuum feed-through provided based on the use of a half-wavelength annular dielectric pressure barrier disk, or multiple disks comprising an effective half wavelength structure to eliminate reflections from the barrier surfaces. Gas-tight seals are formed about the outer and inner diameter surfaces of the barrier disk using a sealing technique which generates radial forces sufficient to form seals by forcing the conductor walls against the surfaces of the barrier disks in a manner which does not deform the radii of the inner and outer conductors, thereby preventing enhancement of the electric field at the barrier faces which limits voltage and power handling capabilities of a feedthrough.

Controlling the hydration of the skin though the application of occluding barrier creams

PubMed Central

Sparr, Emma; Millecamps, Danielle; Isoir, Muriel; Burnier, Véronique; Larsson, Åsa; Cabane, Bernard

2013-01-01

The skin is a barrier membrane that separates environments with profoundly different water contents. The barrier properties are assured by the outer layer of the skin, the stratum corneum (SC), which controls the transepidermal water loss. The SC acts as a responding membrane, since its hydration and permeability vary with the boundary condition, which is the activity of water at the outer surface of the skin. We show how this boundary condition can be changed by the application of a barrier cream that makes a film with a high resistance to the transport of water. We present a quantitative model that predicts hydration and water transport in SC that is covered by such a film. We also develop an experimental method for measuring the specific resistance to water transport of films made of occluding barrier creams. Finally, we combine the theoretical model with the measured properties of the barrier creams to predict how a film of cream changes the activity of water at the outer surface of the SC. Using the known variations of SC permeability and hydration with the water activity in its environment (i.e. the relative humidity), we can thus predict how a film of barrier cream changes SC hydration. PMID:23269846

Controlling the hydration of the skin though the application of occluding barrier creams.

PubMed

Sparr, Emma; Millecamps, Danielle; Isoir, Muriel; Burnier, Véronique; Larsson, Åsa; Cabane, Bernard

2013-03-06

The skin is a barrier membrane that separates environments with profoundly different water contents. The barrier properties are assured by the outer layer of the skin, the stratum corneum (SC), which controls the transepidermal water loss. The SC acts as a responding membrane, since its hydration and permeability vary with the boundary condition, which is the activity of water at the outer surface of the skin. We show how this boundary condition can be changed by the application of a barrier cream that makes a film with a high resistance to the transport of water. We present a quantitative model that predicts hydration and water transport in SC that is covered by such a film. We also develop an experimental method for measuring the specific resistance to water transport of films made of occluding barrier creams. Finally, we combine the theoretical model with the measured properties of the barrier creams to predict how a film of cream changes the activity of water at the outer surface of the SC. Using the known variations of SC permeability and hydration with the water activity in its environment (i.e. the relative humidity), we can thus predict how a film of barrier cream changes SC hydration.

Outgassing of solid material into vacuum thermal insulation spaces

NASA Technical Reports Server (NTRS)

Wang, Pao-Lien

1994-01-01

Many cryogenic storage tanks use vacuum between inner and outer tank for thermal insulation. These cryogenic tanks also use a radiation shield barrier in the vacuum space to prevent radiation heat transfer. This shield is usually constructed by using multiple wraps of aluminized mylar and glass paper as inserts. For obtaining maximum thermal performance, a good vacuum level must be maintained with the insulation system. It has been found that over a period of time solid insulation materials will vaporize into the vacuum space and the vacuum will degrade. In order to determine the degradation of vacuum, the rate of outgassing of the insulation materials must be determined. Outgassing rate of several insulation materials obtained from literature search were listed in tabular form.

Lightweight flywheel containment

DOEpatents

Smith, James R.

2001-01-01

A lightweight flywheel containment composed of a combination of layers of various material which absorb the energy of a flywheel structural failure. The various layers of material act as a vacuum barrier, momentum spreader, energy absorber, and reaction plate. The flywheel containment structure has been experimentally demonstrated to contain carbon fiber fragments with a velocity of 1,000 m/s and has an aerial density of less than 6.5 g/square centimeters. The flywheel containment, may for example, be composed of an inner high toughness structural layer, and energy absorbing layer, and an outer support layer. Optionally, a layer of impedance matching material may be utilized intermediate the flywheel rotor and the inner high toughness layer.

Lightweight flywheel containment

DOEpatents

Smith, James R.

2004-06-29

A lightweight flywheel containment composed of a combination of layers of various material which absorb the energy of a flywheel structural failure. The various layers of material act as a vacuum barrier, momentum spreader, energy absorber, and reaction plate. The flywheel containment structure has been experimentally demonstrated to contain carbon fiber fragments with a velocity of 1,000 m/s and has an aerial density of less than 6.5 g/square centimeters. The flywheel containment, may for example, be composed of an inner high toughness structural layer, and energy absorbing layer, and an outer support layer. Optionally, a layer of impedance matching material may be utilized intermediate the flywheel rotor and the inner high toughness layer.

Slab edge insulating form system and methods

DOEpatents

Lee, Brain E [Corral de Tierra, CA; Barsun, Stephan K [Davis, CA; Bourne, Richard C [Davis, CA; Hoeschele, Marc A [Davis, CA; Springer, David A [Winters, CA

2009-10-06

A method of forming an insulated concrete foundation is provided comprising constructing a foundation frame, the frame comprising an insulating form having an opening, inserting a pocket former into the opening; placing concrete inside the foundation frame; and removing the pocket former after the placed concrete has set, wherein the concrete forms a pocket in the placed concrete that is accessible through the opening. The method may further comprise sealing the opening by placing a sealing plug or sealing material in the opening. A system for forming an insulated concrete foundation is provided comprising a plurality of interconnected insulating forms, the insulating forms having a rigid outer member protecting and encasing an insulating material, and at least one gripping lip extending outwardly from the outer member to provide a pest barrier. At least one insulating form has an opening into which a removable pocket former is inserted. The system may also provide a tension anchor positioned in the pocket former and a tendon connected to the tension anchor.

Multilayer Article Characterized by Low Coefficient of Thermal Expansion Outer Layer

NASA Technical Reports Server (NTRS)

Lee, Kang N. (Inventor)

2004-01-01

A multilayer article comprises a substrate comprising a ceramic or a silicon-containing metal alloy. The ceramic is a Si-containing ceramic or an oxide ceramic with or without silicon. An outer layer overlies the substrate and at least one intermediate layer is located between the outer layer and thc substrate. An optional bond layer is disposed between thc 1 least one intermediate layer and thc substrate. The at least one intermediate layer may comprise an optional chemical barrier layer adjacent the outer layer, a mullite-containing layer and an optional chemical barrier layer adjacent to the bond layer or substrate. The outer layer comprises a compound having a low coefficient of thermal expansion selected from one of the following systems: rare earth (RE) silicates; at least one of hafnia and hafnia-containing composite oxides; zirconia-containing composite oxides and combinations thereof.

Pseudomonas aeruginosa reveals high intrinsic resistance to penem antibiotics: penem resistance mechanisms and their interplay.

PubMed

Okamoto, K; Gotoh, N; Nishino, T

2001-07-01

Pseudomonas aeruginosa exhibits high intrinsic resistance to penem antibiotics such as faropenem, ritipenem, AMA3176, sulopenem, Sch29482, and Sch34343. To investigate the mechanisms contributing to penem resistance, we used the laboratory strain PAO1 to construct a series of isogenic mutants with an impaired multidrug efflux system MexAB-OprM and/or impaired chromosomal AmpC beta-lactamase. The outer membrane barrier of PAO1 was partially eliminated by inducing the expression of the plasmid-encoded Escherichia coli major porin OmpF. Susceptibility tests using the mutants and the OmpF expression plasmid showed that MexAB-OprM and the outer membrane barrier, but not AmpC beta-lactamase, are the main mechanisms involved in the high intrinsic penem resistance of PAO1. However, reducing the high intrinsic penem resistance of PAO1 to the same level as that of penem-susceptible gram-negative bacteria such as E. coli required the loss of either both MexAB-OprM and AmpC beta-lactamase or both MexAB-OprM and the outer membrane barrier. Competition experiments for penicillin-binding proteins (PBPs) revealed that the affinity of PBP 1b and PBP 2 for faropenem were about 1.8- and 1.5-fold lower, than the respective affinity for imipenem. Loss of the outer membrane barrier, MexAB, and AmpC beta-lactamase increased the susceptibility of PAO1 to almost all penems tested compared to the susceptibility of the AmpC-deficient PAO1 mutants to imipenem. Thus, it is suggested that the high intrinsic penem resistance of P. aeruginosa is generated from the interplay among the outer membrane barrier, the active efflux system, and AmpC beta-lactamase but not from the lower affinity of PBPs for penems.

Pseudomonas aeruginosa Reveals High Intrinsic Resistance to Penem Antibiotics: Penem Resistance Mechanisms and Their Interplay

PubMed Central

Okamoto, Kiyomi; Gotoh, Naomasa; Nishino, Takeshi

2001-01-01

Pseudomonas aeruginosa exhibits high intrinsic resistance to penem antibiotics such as faropenem, ritipenem, AMA3176, sulopenem, Sch29482, and Sch34343. To investigate the mechanisms contributing to penem resistance, we used the laboratory strain PAO1 to construct a series of isogenic mutants with an impaired multidrug efflux system MexAB-OprM and/or impaired chromosomal AmpC β-lactamase. The outer membrane barrier of PAO1 was partially eliminated by inducing the expression of the plasmid-encoded Escherichia coli major porin OmpF. Susceptibility tests using the mutants and the OmpF expression plasmid showed that MexAB-OprM and the outer membrane barrier, but not AmpC β-lactamase, are the main mechanisms involved in the high intrinsic penem resistance of PAO1. However, reducing the high intrinsic penem resistance of PAO1 to the same level as that of penem-susceptible gram-negative bacteria such as E. coli required the loss of either both MexAB-OprM and AmpC β-lactamase or both MexAB-OprM and the outer membrane barrier. Competition experiments for penicillin-binding proteins (PBPs) revealed that the affinity of PBP 1b and PBP 2 for faropenem were about 1.8- and 1.5-fold lower, than the respective affinity for imipenem. Loss of the outer membrane barrier, MexAB, and AmpC β-lactamase increased the susceptibility of PAO1 to almost all penems tested compared to the susceptibility of the AmpC-deficient PAO1 mutants to imipenem. Thus, it is suggested that the high intrinsic penem resistance of P. aeruginosa is generated from the interplay among the outer membrane barrier, the active efflux system, and AmpC β-lactamase but not from the lower affinity of PBPs for penems. PMID:11408209

When Might Barrier Island Chains 'Collapse'? An Initial Model Investigation

NASA Astrophysics Data System (ADS)

Slott, J. M.; Murray, A. B.

2007-12-01

There has been recent speculation that, in response to the accelerated sea-level rise and intensified storms expected over the coming century, barrier island chains such as those found on the US Atlantic and Gulf coastlines, could develop large (10-kilometer-scale) gaps in their most narrow stretches, or might disappear completely (Riggs, S. R., 2001). Such a collapse along the North Carolina Outer Banks barrier island chain, for example, would leave the mainland vulnerable to direct hits from Western Atlantic storm systems, and also would dramatically alter the estuarine system it encloses with potentially devastating effects to marine life. Concern for the future of the Outer Banks is also motivated by the decimation of the Chandeleur Islands in 2005 from Hurricane Katrina. We will present a series of initial numerical modeling experiments addressing how barrier island morphodynamics respond to the sudden creation of kilometer-scale gaps. Large-scale barrier island evolution is influenced by sea-level rise and barrier island overwash, alongshore sediment transport, tidal currents, and the availability of mobile sediment. Barrier islands transgress towards the mainland in response to sea-level rise through overwash: ocean-facing shorelines provide sediment that is transported onto the island to maintain its subaerial height and behind the island to maintain its width, while gradients in alongshore sediment transport typically dictate the large-scale shape of a coastline over long time frames (decades to millenia). Tidal currents also tend to scour inlet channels; the relative strength of this effect depends in part upon the width of the inlet channel. Our exploratory model includes both a one-line alongshore transport component and a cross-shore overwash component, as well as representations of underlying geology (weathering rates and material compositions). In our modeling experiments, we test the effects of perforating a 30 km barrier island chain with variable-sized gaps, ranging between 2.5-10 km. In preliminary model experiments, where we do not limit the availability of mobile sediment nor include tidal inlet dynamics, large gaps tend to close under all of the erosion rate scenarios and gap sizes. The ends of barrier islands extend to fill in the gaps and recurve landward. The rate of closure of gaps is unaffected by sea-level rise rates even under the most extreme cases; alongshore sediment fluxes exceed those associated with sea-level rise as highly curved isolated islands migrate rapidly landward before coalescing into an island chain again at a new location. In a natural setting, the overwash and spit-growth that maintain sub-aerial islands and tend to knit them back together (respectively) could be inhibited by a lack of mobile sediment. The shoreface of the Outer Banks, for example, consists of sometimes patchy Holocene sands perched atop a semi-lithified, sometimes more muddy Pleistocene substrate. Weathering of the Pleistocene substrate over long timescales generates mobile sediment consisting of both sands and muds. The fine-grained material, however, is typically lost to the nearshore system. The shoreface may not be able to weather fast enough to keep up with rapidly migrating islands. This effect, combined with that of substrate composition, will tend to limit the rate that sediment can be liberated, and, in turn, could prevent island-chain recovery. We conduct a series of model experiments to determine the combinations of geological parameters (weathering rates, composition) and forcing parameters (rate of sea-level rise, frequency of storms) that prevent barrier-island-chain recovery.

Integrated fuel cell stack shunt current prevention arrangement

DOEpatents

Roche, Robert P.; Nowak, Michael P.

1992-01-01

A fuel cell stack includes a plurality of fuel cells juxtaposed with one another in the stack and each including a pair of plate-shaped anode and cathode electrodes that face one another, and a quantity of liquid electrolyte present at least between the electrodes. A separator plate is interposed between each two successive electrodes of adjacent ones of the fuel cells and is unified therewith into an integral separator plate. Each integral separator plate is provided with a circumferentially complete barrier that prevents flow of shunt currents onto and on an outer peripheral surface of the separator plate. This barrier consists of electrolyte-nonwettable barrier members that are accommodated, prior to the formation of the integral separator plate, in corresponding edge recesses situated at the interfaces between the electrodes and the separator plate proper. Each barrier member extends over the entire length of the associated marginal portion and is flush with the outer periphery of the integral separator plate. This barrier also prevents cell-to-cell migration of any electrolyte that may be present at the outer periphery of the integral separator plate while the latter is incorporated in the fuel cell stack.

Particle trap with dielectric barrier for use in gas insulated transmission lines

DOEpatents

Dale, Steinar J.

1982-01-01

A gas-insulated transmission line includes an outer sheath, an inner conductor within the outer sheath, insulating supports supporting the inner conductor within the outer sheath, and an insulating gas electrically insulating the inner conductor from the outer sheath. An apertured particle trapping electrode is disposed within the outer sheath, and the electrode has a pair of dielectric members secured at each longitudinal end thereof, with the dielectric members extending outwardly from the apertured electrode.

Formation of ZrO{sub 2} in coating on Mg–3 wt.%Al–1 wt.%Zn alloy via plasma electrolytic oxidation: Phase and structure of zirconia

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

Lee, Kang Min; Kim, Yeon Sung; Yang, Hae Woong

2015-01-15

An investigation of the coating structure formed on Mg–3 wt.%Al–1 wt.%Zn alloy sample subjected to plasma electrolytic oxidation was examined by field-emission transmission electron microscopy. The plasma electrolytic oxidation process was conducted in a phosphoric acid electrolyte containing K{sub 2}ZrF{sub 6} for 600 s. Microstructural observations showed that the coating consisting of MgO, MgF{sub 2}, and ZrO{sub 2} phases was divided into three distinctive parts, the barrier, intermediate, and outer layers. Nanocrystalline MgO and MgF{sub 2} compounds were observed mainly in the barrier layer of ~ 1 μm thick near to the substrate. From the intermediate to outer layers, variousmore » ZrO{sub 2} polymorphs appeared due to the effects of the plasma arcing temperature on the phase transition of ZrO{sub 2} compounds during the plasma electrolytic oxidation process. In the outer layer, MgO compound grew in the form of a dendrite-like structure surrounded by cubic ZrO{sub 2}. - Highlights: • The barrier layer containing MgO and MgF{sub 2} was observed near to the Mg substrate. • In the intermediate layer, m-, t-, and o-ZrO{sub 2} compounds were additionally detected. • The outer layer contained MgO with the dendrite-like structure surrounded by c-ZrO{sub 2}. • The grain sizes of compounds in oxide layer increased from barrier to outer layer.« less

Particle trap with dielectric barrier for use in gas insulated transmission lines

DOEpatents

Dale, S.J.

1982-06-15

A gas-insulated transmission line includes an outer sheath, an inner conductor within the outer sheath, insulating supports supporting the inner conductor within the outer sheath, and an insulating gas electrically insulating the inner conductor from the outer sheath. An apertured particle trapping electrode is disposed within the outer sheath, and the electrode has a pair of dielectric members secured at each longitudinal end thereof, with the dielectric members extending outwardly from the apertured electrode. 7 figs.

Beyond the Barrier: Communication in the Root through the Endodermis1

PubMed Central

Robbins, Neil E.; Trontin, Charlotte; Duan, Lina; Dinneny, José R.

2014-01-01

The root endodermis is characterized by the Casparian strip and by the suberin lamellae, two hydrophobic barriers that restrict the free diffusion of molecules between the inner cell layers of the root and the outer environment. The presence of these barriers and the position of the endodermis between the inner and outer parts of the root require that communication between these two domains acts through the endodermis. Recent work on hormone signaling, propagation of calcium waves, and plant-fungal symbiosis has provided evidence in support of the hypothesis that the endodermis acts as a signaling center. The endodermis is also a unique mechanical barrier to organogenesis, which must be overcome through chemical and mechanical cross talk between cell layers to allow for development of new lateral organs while maintaining its barrier functions. In this review, we discuss recent findings regarding these two important aspects of the endodermis. PMID:25125504

All-Diamond Microelectrodes as Solid State Probes for Localized Electrochemical Sensing.

PubMed

Silva, Eduardo L; Gouvêa, Cristol P; Quevedo, Marcela C; Neto, Miguel A; Archanjo, Braulio S; Fernandes, António J S; Achete, Carlos A; Silva, Rui F; Zheludkevich, Mikhail L; Oliveira, Filipe J

2015-07-07

The fabrication of an all-diamond microprobe is demonstrated for the first time. This ME (microelectrode) assembly consists of an inner boron doped diamond (BDD) layer and an outer undoped diamond layer. Both layers were grown on a sharp tungsten tip by chemical vapor deposition (CVD) in a stepwise manner within a single deposition run. BDD is a material with proven potential as an electrochemical sensor. Undoped CVD diamond is an insulating material with superior chemical stability in comparison to conventional insulators. Focused ion beam (FIB) cutting of the apex of the ME was used to expose an electroactive BDD disk. By cyclic voltammetry, the redox reaction of ferrocenemethanol was shown to take place at the BDD microdisk surface. In order to ensure that the outer layer was nonelectrically conductive, a diffusion barrier for boron atoms was established seeking the formation of boron-hydrogen complexes at the interface between the doped and the undoped diamond layers. The applicability of the microelectrodes in localized corrosion was demonstrated by scanning amperometric measurements of oxygen distribution above an Al-Cu-CFRP (Carbon Fiber Reinforced Polymer) galvanic corrosion cell.

Explaining the apparent impenetrable barrier to ultra-relativistic electrons in the outer Van Allen belt.

PubMed

Ozeke, Louis G; Mann, Ian R; Murphy, Kyle R; Degeling, Alex W; Claudepierre, Seth G; Spence, Harlan E

2018-05-10

Recent observations have shown the existence of an apparent impenetrable barrier at the inner edge of the ultra-relativistic outer electron radiation belt. This apparent impenetrable barrier has not been explained. However, recent studies have suggested that fast loss, such as associated with scattering into the atmosphere from man-made very-low frequency transmissions, is required to limit the Earthward extent of the belt. Here we show that the steep flux gradient at the implied barrier location is instead explained as a natural consequence of ultra-low frequency wave radial diffusion. Contrary to earlier claims, sharp boundaries in fast loss processes at the barrier are not needed. Moreover, we show that penetration to the barrier can occur on the timescale of days rather than years as previously reported, with the Earthward extent of the belt being limited by the finite duration of strong solar wind driving, which can encompass only a single geomagnetic storm.

Microinjector for blasocysts

DOEpatents

Remenyik, Carl J.; Woychik, Richard P.; Patek, David R.; Hawk, James A.; Turner, John C.

1999-01-01

An electromechanical device for driving the tip of a microinjection cannula, or needle, through the outer barrier of a blastocyst, cell, or cell nucleus for the injection of cells or other bioactive materials. Either a flexible frame or a ram moving within a base member is employed. Cannula motion is achieved by means of a piezoelectric stack and spring return system. The thrust motion over a predetermined microscopic distance is achieved without cannula setback prior to the thrust movement. Instead of specially prepared beveled and tipped needles, standard unimproved cannulas or needles can be used.

Microinjector for blasocysts

DOEpatents

Remenyik, C.J.; Woychik, R.P.; Patek, D.R.; Hawk, J.A.; Turner, J.C.

1999-03-02

An electromechanical device is disclosed for driving the tip of a microinjection cannula, or needle, through the outer barrier of a blastocyst, cell, or cell nucleus for the injection of cells or other bioactive materials. Either a flexible frame or a ram moving within a base member is employed. Cannula motion is achieved by means of a piezoelectric stack and spring return system. The thrust motion over a predetermined microscopic distance is achieved without cannula setback prior to the thrust movement. Instead of specially prepared beveled and tipped needles, standard unimproved cannulas or needles can be used. 6 figs.

Penetration resistant barrier

DOEpatents

Hoover, William R.; Mead, Keith E.; Street, Henry K.

1977-01-01

The disclosure relates to a barrier for resisting penetration by such as hand tools and oxy-acetylene cutting torches. The barrier comprises a layer of firebrick, which is preferably epoxy impregnated sandwiched between inner and outer layers of steel. Between the firebrick and steel are layers of resilient rubber-like filler.

Method of Fabricating Protective Coating for a Crucible with the Coating Having Channels Formed Therein

NASA Technical Reports Server (NTRS)

Grugel, Richard N. (Inventor)

2004-01-01

A method is provided for the fabrication of a protective coating for a crucible with channels being formed in the coating. A material is adhered to the outer wall of the crucible to form a pattern thereon. The outer wall of the crucible along with the pattern of material adhered thereto is next coated with another material. The material used to form the pattern should extend through the outer material coating to define at least one port therein. Next, the crucible with its pattern of material and outer coating material is heated to a temperature of transformation at which the pattern of material is transformed to a fluidic state while the crucible and outer coating material maintain their solid integrity. Such transformation could also be accomplished by using a solvent that causes the pattern of material to dissolve. Finally, the material in its fluidic state is removed via the at least one port formed in the outer material coating thereby leaving channels defined in the coating adjacent the outer wall of the crucible.

Barrier properties of cultured retinal pigment epithelium.

PubMed

Rizzolo, Lawrence J

2014-09-01

The principal function of an epithelium is to form a dynamic barrier that regulates movement between body compartments. Each epithelium is specialized with barrier functions that are specific for the tissues it serves. The apical surface commonly faces a lumen, but the retinal pigment epithelium (RPE) appears to be unique by a facing solid tissue, the sensory retina. Nonetheless, there exists a thin (subretinal) space that can become fluid filled during pathology. RPE separates the subretinal space from the blood supply of the outer retina, thereby forming the outer blood-retinal barrier. The intricate interaction between the RPE and sensory retina presents challenges for learning how accurately culture models reflect native behavior. The challenge is heightened by findings that detail the variation of RPE barrier proteins both among species and at different stages of the life cycle. Among the striking differences is the expression of claudin family members. Claudins are the tight junction proteins that regulate ion diffusion across the spaces that lie between the cells of a monolayer. Claudin expression by RPE varies with species and life-stage, which implies functional differences among commonly used animal models. Investigators have turned to transcriptomics to supplement functional studies when comparing native and cultured tissue. The most detailed studies of the outer blood-retinal barrier have focused on human RPE with transcriptome and functional studies reported for human fetal, adult, and stem-cell derived RPE. Copyright © 2014 Elsevier Ltd. All rights reserved.

Luminescence dating of the barrier spit at Chilika Lake, Orissa, India.

PubMed

Murray, A S; Mohanti, M

2006-01-01

Optically stimulated luminescence dating has been used to investigate the chronological development of the outer barrier spit forming Chilika Lake (Orissa, India), the largest brackish-water lagoon in Asia. Sixteen samples were examined, and these yielded equivalent doses of between 153 +/- 3 mGy and 2.23 +/- 0.07 Gy, corresponding to ages from approximately 40 y at the top of the spit to approximately 300 y at the bottom. The youngest ages are consistent with the age of the overlying vegetation, and modern material taken from the sub-tidal beach gave a dose of 4 +/- 2 mGy (corresponding to an age of 0.7 +/- 0.4 y), confirming that any previous potential luminescence signal in the source sediment is completely set to zero before incorporation into the spit. A clearly defined period of >2.5 m of barrier construction approximately 40 y ago is identified; prior to that the deposition rate was relatively constant for approximately 300 y.

Inner Blood-Retinal Barrier Dominantly Expresses Breast Cancer Resistance Protein: Comparative Quantitative Targeted Absolute Proteomics Study of CNS Barriers in Pig.

PubMed

Zhang, Zhengyu; Uchida, Yasuo; Hirano, Satoshi; Ando, Daisuke; Kubo, Yoshiyuki; Auriola, Seppo; Akanuma, Shin-Ichi; Hosoya, Ken-Ichi; Urtti, Arto; Terasaki, Tetsuya; Tachikawa, Masanori

2017-11-06

The purpose of this study was to determine absolute protein expression levels of transporters at the porcine inner blood-retinal barrier (BRB) and to compare the transporter protein expression quantitatively among the inner BRB, outer BRB, blood-brain barrier (BBB), and blood-cerebrospinal fluid barrier (BCSFB). Crude membrane fractions of isolated retinal capillaries (inner BRB) and isolated retinal pigment epithelium (RPE, outer BRB) were prepared from porcine eyeballs, while plasma membrane fractions were prepared from isolated porcine brain capillaries (BBB) and isolated choroid plexus (BCSFB). Protein expression levels of 32 molecules, including 16 ATP-binding-cassette (ABC) transporters and 13 solute-carrier (SLC) transporters, were measured using a quantitative targeted absolute proteomic technique. At the inner BRB, five molecules were detected: breast cancer resistance protein (BCRP, ABCG2; 22.8 fmol/μg protein), multidrug resistance protein 1 (MDR1, ABCB1; 8.70 fmol/μg protein), monocarboxylate transporter 1 (MCT1, SLC16A1; 4.83 fmol/μg protein), glucose transporter 1 (GLUT1, SLC2A1; 168 fmol/μg protein), and sodium-potassium adenosine triphosphatase (Na + /K + -ATPase; 53.7 fmol/μg protein). Other proteins were under the limits of quantification. Expression of MCT1 was at least 17.6-, 11.0-, and 19.2-fold greater than those of MCT2, 3, and 4, respectively. The transporter protein expression at the inner BRB was most highly correlated with that at the BBB (R 2 = 0.8906), followed by outer BRB (R 2 = 0.7988) and BCSFB (R 2 = 0.4730). Sodium-dependent multivitamin transporter (SMVT, SLC5A6) and multidrug resistance-associated protein 1 (MRP1, ABCC1) were expressed at the outer BRB (0.378 and 1.03 fmol/μg protein, respectively) but were under the limit of quantification at the inner BRB. These findings may be helpful for understanding differential barrier function.

Extermophylic microorganisms: issue of interplanetary transfer on external spacecraft surfaces.

NASA Astrophysics Data System (ADS)

Novikova, N.; Deshevaya, E.; Polykarpov, N.; Svistunova, Y.; Grigoriev, A.

Interplanetary transfer of terrestrial microbes capable of surviving in extreme environments and planetary protection from accidental biocontamination by them are the issues of major practical rather than hypothetical value The natural resistance of microbes to extreme environments and a possibility of their transfer beyond geographical barriers of Earth on external spacecraft surfaces have brought forward a need in profound research into the likelihood of their survival in outer space Hardware and a program have been developed at the State Scientific Research Center of the Russian Federation -- Institute for Biomedical Problems with the goal of carrying out a space experiment Biorisk The experiment was aimed at assessing the possibility of long-term comparable with the duration of the Martian flight survival of microorganisms in outer space on materials used in space industry Samples of materials were contaminated with test cultures of bacteria Bacillus and fungi Aspergillus Penicillium Cladosporium known to be common residents of various environments on Earth and resistant to multiple alternation of high and low temperatures Materials used in the construction of external spacecraft surfaces such as steel aluminium alloy heat-insulating coating were chosen as test samples for the experiment Containers with materials and test microorganisms were placed on the external side of the Russian segment of the ISS Unique data have been accumulated after a 204 day exposure on the external side of the ISS which have proved that

The structure of anchovy outer retinae (Engraulididae, Clupeiformes) - a comparative light- and electron-microscopic study using museum-stored material.

PubMed

Hess, Martin; Melzer, Roland R; Eser, Roland; Smola, Ulrich

2006-11-01

The outer retinal architecture of Engraulididae is uncommon among vertebrates. In some anchovies, e.g., Anchoa, two cone types are arranged alternating in long photoreceptor chains, i.e., polycones. The cones have radially oriented outer segment lamellae in close contact with a complex guanine tapetum, most probably subserving polarization contrast vision. To clarify the distribution of the aberrant polycone architecture within the Engraulididae and to provide indications about polycone evolution, the outer retina morphology of 16 clupeoid species was investigated by light and electron microscopy, predominantly using museum-stored material. The outgroup representatives of four clupeid subfamilies (Clupeonella cultriventris, Dorosoma cepedianum, Ethmalosa fimbriata, Pellonula leonensis) show a row pattern of double cones, partially with single cones at defined positions and a pigment epithelium with lobopodial protrusions containing melanin. The pristigasterid Ilisha africana has double rows of single cones lying between linear curtains of pigment epithelium processes filled with minute crystallites and melanin concentrated near their vitreal tips. Within the Engraulididae, two main architectures are found: Coilia nasus and Thryssa setirostris have linear multiple cones or polycones separated by long pigment epithelium barriers containing tapetal crystallites and melanin in the tips (also found in Setipinna taty), whereas Anchoviella alleni, Encrasicholina heteroloba, Engraulis encrasicolus, Engraulis mordax, Lycengraulis batesii, and Stolephorus indicus exhibit the typical polycone architecture. Cetengraulis mysticetus and Lycothrissa crocodilus show cone patterns and pigment epithelium morphology differing from the other anchovy species. The sets of characters are compared, corroborated with the previous knowledge on clupeoid retinae and discussed in terms of functional morphology and visual ecology. A scenario on polycone evolution is developed that may serve as an aid for the reconstruction of engraulidid phylogeny. Furthermore, this study demonstrates the suitability of museum material for morphological studies, even at the electron microscopic level. Copyright 2006 Wiley-Liss, Inc.

Erosion resistant elbow for solids conveyance

DOEpatents

Everett, J.W.

1984-10-23

An elbow and process for fabrication for use in particulate material conveyancing comprises a curved outer pipe, a curved inner pipe having the same radius of curvature as the outer pipe, concentric with and internal to the outer pipe, comprising an outer layer comprised of a first material and an inner layer comprised of a second material wherein said first material is characterized by high erosion resistance when impinged by particulate material and wherein said second material is characterized by high tensile strength and flexibility, and an inner pipe supporting means for providing support to said inner pipe, disposed between said inner pipe and said outer pipe. 4 figs.

Erosion resistant elbow for solids conveyance

DOEpatents

Everett, James W.

1984-10-23

An elbow and process for fabrication for use in particulate material conveyancing comprising a curved outer pipe, a curved inner pipe having the same radius of curvature as the outer pipe, concentric with and internal to the outer pipe, comprising an outer layer comprised of a first material and an inner layer comprised of a second material wherein said first material is characterized by high erosion resistance when impinged by particulate material and wherein said second material is characterized by high tensile strength and flexibility, and an inner pipe supporting means for providing support to said inner pipe, disposed between said inner pipe and said outer pipe.

Erosion resistant elbow for solids conveyance

DOEpatents

Not Available

An elvow and process for fabrication for use in particulate material conveying comprising a curved outer pipe, a curved inner pipe having the same radius of curvature as the outer pipe, concentric with and internal to the outer pipe, comprising an outer layer comprised of a first material and an inner layer comprised of a second material wherein said first material is characterized by high erosion resistance when impinged by particulate material and wherein said second material is characterized by high tensile strength and flexibility, and an inner pipe supporting means for providing support to said inner pipe, disposed between said inner pipe and said outer pipe. 4 figures.

The Escherichia coli Phospholipase PldA Regulates Outer Membrane Homeostasis via Lipid Signaling.

PubMed

May, Kerrie L; Silhavy, Thomas J

2018-03-20

The outer membrane (OM) bilayer of Gram-negative bacteria is biologically unique in its asymmetrical organization of lipids, with an inner leaflet composed of glycerophospholipids (PLs) and a surface-exposed outer leaflet composed of lipopolysaccharide (LPS). This lipid organization is integral to the OM's barrier properties. Perturbations of the outer leaflet by antimicrobial peptides or defects in LPS biosynthesis or transport to the OM cause a compensatory flipping of PLs to the outer leaflet. As a result, lipid asymmetry is disrupted and OM integrity is compromised. Recently, we identified an Escherichia coli mutant that exhibits aberrant accumulation of surface PLs accompanied by a cellular increase in LPS production. Remarkably, the observed hyperproduction of LPS is PldA dependent. Here we provide evidence that the fatty acids generated by PldA at the OM are transported into the cytoplasm and simultaneously activated by thioesterification to coenzyme A (CoA) by FadD. The acyl-CoAs produced ultimately inhibit LpxC degradation by FtsH. The increased levels of LpxC, the enzyme that catalyzes the first committed step in LPS biosynthesis, increases the amount of LPS produced. Our data suggest that PldA acts as a sensor for lipid asymmetry in the OM. PldA protects the OM barrier by both degrading mislocalized PLs and generating lipid second messengers that enable long-distance signaling that prompts the cell to restore homeostasis at a distant organelle. IMPORTANCE The outer membrane of Gram-negative bacteria is an effective permeability barrier that protects the cell from toxic agents, including antibiotics. Barrier defects are often manifested by phospholipids present in the outer leaflet of this membrane that take up space normally occupied by lipopolysaccharide. We have discovered a signaling mechanism that operates across the entire cell envelope used by the cell to detect these outer membrane defects. A phospholipase, PldA, that functions to degrade these mislocalized phospholipids has a second, equally important function as a sensor. The fatty acids produced by hydrolysis of the phospholipids act as second messengers to signal the cell that more lipopolysaccharide is needed. These fatty acids diffuse across the periplasm and are transported into the cytoplasm by a process that attaches coenzyme A. The acyl-CoA molecule produces signals to inhibit the degradation of the critical enzyme LpxC by the ATP-dependent protease FtsH, increasing lipopolysaccharide production. Copyright © 2018 May and Silhavy.

Material with core-shell structure

DOEpatents

Luhrs, Claudia [Rio Rancho, NM; Richard, Monique N [Ann Arbor, MI; Dehne, Aaron [Maumee, OH; Phillips, Jonathan [Rio Rancho, NM; Stamm, Kimber L [Ann Arbor, MI; Fanson, Paul T [Brighton, MI

2011-11-15

Disclosed is a material having a composite particle, the composite particle including an outer shell and a core. The core is made from a lithium alloying material and the outer shell has an inner volume that is greater in size than the core of the lithium alloying material. In some instances, the outer mean diameter of the outer shell is less than 500 nanometers and the core occupies between 5 and 99% of the inner volume. In addition, the outer shell can have an average wall thickness of less than 100 nanometers.

Framework of barrier reefs threatened by ocean acidification.

PubMed

Comeau, Steeve; Lantz, Coulson A; Edmunds, Peter J; Carpenter, Robert C

2016-03-01

To date, studies of ocean acidification (OA) on coral reefs have focused on organisms rather than communities, and the few community effects that have been addressed have focused on shallow back reef habitats. The effects of OA on outer barrier reefs, which are the most striking of coral reef habitats and are functionally and physically different from back reefs, are unknown. Using 5-m long outdoor flumes to create treatment conditions, we constructed coral reef communities comprised of calcified algae, corals, and reef pavement that were assembled to match the community structure at 17 m depth on the outer barrier reef of Moorea, French Polynesia. Communities were maintained under ambient and 1200 μatm pCO2 for 7 weeks, and net calcification rates were measured at different flow speeds. Community net calcification was significantly affected by OA, especially at night when net calcification was depressed ~78% compared to ambient pCO2 . Flow speed (2-14 cm s(-1) ) enhanced net calcification only at night under elevated pCO2 . Reef pavement also was affected by OA, with dissolution ~86% higher under elevated pCO2 compared to ambient pCO2 . These results suggest that net accretion of outer barrier reef communities will decline under OA conditions predicted within the next 100 years, largely because of increased dissolution of reef pavement. Such extensive dissolution poses a threat to the carbonate foundation of barrier reef communities. © 2015 John Wiley & Sons Ltd.

Method for preparing a sodium/sulfur cell

DOEpatents

Weiner, Steven A.

1978-01-01

A method for preparing a sodium/sulfur cell comprising (A) inserting a solid sodium slug, adapted to be connected to an external circuit, into the anodic reaction zone of a cell subassembly maintained within an inert atmosphere, said cell subassembly comprising a cell container and a tubular cation-permeable barrier disposed within said container such that a first reaction zone is located within cation-permeable barrier and a second reaction zone is located between the outer surface of said cation-permeable barrier and the inner surface of said container, one of said reaction zones being said anodic reaction zone and the other of said reaction zone being a cathodic reaction zone containing a precast composite cathodic reactant comprising a sulfur impregnated porous conductive material connected to said cation permeable barrier and adapted to be connected to said external circuit; and (B) providing closure means for said subassembly and sealing the same to said subassembly at a temperature less than about 100.degree. C. The method of the invention overcomes deficiencies of the prior art methods by allowing preparation of a sodium/sulfur cell without the use of molten reactants and the fill spouts which are required when the cell is filled with molten reactants.

Vented Cavity Radiant Barrier Assembly And Method

DOEpatents

Dinwoodie, Thomas L.; Jackaway, Adam D.

2000-05-16

A vented cavity radiant barrier assembly (2) includes a barrier (12), typically a PV module, having inner and outer surfaces (18, 22). A support assembly (14) is secured to the barrier and extends inwardly from the inner surface of the barrier to a building surface (14) creating a vented cavity (24) between the building surface and the barrier inner surface. A low emissivity element (20) is mounted at or between the building surface and the barrier inner surface. At least part of the cavity exit (30) is higher than the cavity entrance (28) to promote cooling air flow through the cavity.

ELECTRON DISCHARGE DEVICE

DOEpatents

Graham, M.H.

1962-09-18

A barrier-grid storage tube and an improved means for writing and reading of information in such a tube are described. A triax cable is provided in the reading and writing circuit and includes a coiled portion. The inner conductor of the cable is connected to the back plate of the barrier grid target assembly of the storage tube, the middle conductor of the cable is connected to a shielding member encompassing the target assembly and this member supports the barrier grid of the assembly, and the outer conductor of the cable is connected to an external shreld surrounding the target assembly. A source of writing sr- gnals is connected between the rnner conductor and middle conductor of said cable. Both the middle and outer conductors are connected to ground at the source end, and a small trimmer condenser is connected between the external shield and the source end of the inner conductor of the cable to compensate for the direct back plate-to-ground capacity due to the imperfect shielding of the barrier grid. The coiled portion of the cable provides for an output signal to a secondary corl coupled thereto. The grounded outer conductor serves as a means for preventing an output signal being applied to the coiled portion of the cable on application of writing signals to the inner and middle conductors of the cable. (AEC)

Proton and hydrogen transport through two-dimensional monolayers

NASA Astrophysics Data System (ADS)

Seel, Max; Pandey, Ravindra

2016-06-01

Diffusion of protons and hydrogen atoms in representative two-dimensional materials is investigated. Specifically, density functional calculations were performed on graphene, hexagonal boron nitride (h-BN), phosphorene, silicene, and molybdenum disulfide (MoS2) monolayers to study the surface interaction and penetration barriers for protons and hydrogen atoms employing finite cluster models. The calculated barrier heights correlate approximately with the size of the opening formed by the three-fold open sites in the monolayers considered. They range from 1.56 eV (proton) and 4.61 eV (H) for graphene to 0.12 eV (proton) and 0.20 eV (H) for silicene. The results indicate that only graphene and h-BN monolayers have the potential for membranes with high selective permeability. The MoS2 monolayer behaves differently: protons and H atoms become trapped between the outer S layers in the Mo plane in a well with a depth of 1.56 eV (proton) and 1.5 eV (H atom), possibly explaining why no proton transport was detected, suggesting MoS2 as a hydrogen storage material instead. For graphene and h-BN, off-center proton penetration reduces the barrier to 1.38 eV for graphene and 0.11 eV for h-BN. Furthermore, Pt acting as a substrate was found to have a negligible effect on the barrier height. In defective graphene, the smallest barrier for proton diffusion (1.05 eV) is found for an oxygen-terminated defect. Therefore, it seems more likely that thermal protons can penetrate a monolayer of h-BN but not graphene and defects are necessary to facilitate the proton transport in graphene.

49 CFR 173.4a - Excepted quantities.

Code of Federal Regulations, 2014 CFR

2014-10-01

... this section; and (3) For gases a water capacity of 30 mL (1.8 cubic inches) or less. (d) Outer... outer packaging must not exceed the limits provided in the following paragraphs. For outer packagings..., rigid outer packaging. (5) Placement of the material in the package or packing different materials in...

49 CFR 173.4a - Excepted quantities.

Code of Federal Regulations, 2013 CFR

2013-10-01

... this section; and (3) For gases a water capacity of 30 mL (1.8 cubic inches) or less. (d) Outer... outer packaging must not exceed the limits provided in the following paragraphs. For outer packagings..., rigid outer packaging. (5) Placement of the material in the package or packing different materials in...

Autofluorescence from the outer retina and subretinal space: hypothesis and review.

PubMed

Spaide, Richard

2008-01-01

To review the pathophysiologic principles underlying increased autofluorescence from the outer retina and subretinal space using selected diseases as examples. The ocular imaging information and histopathologic features, when known, were integrated for diseases causing increased autofluorescence from the outer retina and subretinal space. Inferences were taken from this information and used to create a classification scheme. These diseases are principally those that cause separation of the outer retina from the retinal pigment epithelium, thereby preventing proper phagocytosis of photoreceptor outer segments. The separation can arise from increased exudation into the subretinal space or inadequate removal of fluid from the subretinal space. Lack of normal outer segment processing initially leads to increased accumulation of outer segments on the outer retina and subretinal space. Over time, this material is visible as an increasingly thick coating on the outer retina, is yellow, and is autofluorescent. Over time, atrophy develops with thinning of the deposited material and decreasing autofluorescence. The accumulated material is ultimately capable of inducing damage to the retinal pigment epithelium. Diseases causing accumulation of the material include central serous chorioretinopathy, vitelliform macular dystrophy, acute exudative polymorphous vitelliform maculopathy, choroidal tumors, and vitreomacular traction syndrome. The physical separation of the retinal outer segments from the retinal pigment epithelium hinders proper phagocytosis of the outer segments. Accumulation of the shed but not phagocytized outer segments plays a role in disease manifestations for a number of macular diseases.

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.

9 CFR 355.15 - Inedible material operating and storage rooms; outer premises, docks, driveways, etc.; fly...

Code of Federal Regulations, 2012 CFR

2012-01-01

... storage rooms; outer premises, docks, driveways, etc.; fly-breeding material; nuisances. 355.15 Section....15 Inedible material operating and storage rooms; outer premises, docks, driveways, etc.; fly... departments where certified products are prepared, handled, or stored. Docks and areas where cars and vehicles...

9 CFR 355.15 - Inedible material operating and storage rooms; outer premises, docks, driveways, etc.; fly...

Code of Federal Regulations, 2014 CFR

2014-01-01

... storage rooms; outer premises, docks, driveways, etc.; fly-breeding material; nuisances. 355.15 Section....15 Inedible material operating and storage rooms; outer premises, docks, driveways, etc.; fly... departments where certified products are prepared, handled, or stored. Docks and areas where cars and vehicles...

9 CFR 355.15 - Inedible material operating and storage rooms; outer premises, docks, driveways, etc.; fly...

Code of Federal Regulations, 2013 CFR

2013-01-01

... storage rooms; outer premises, docks, driveways, etc.; fly-breeding material; nuisances. 355.15 Section....15 Inedible material operating and storage rooms; outer premises, docks, driveways, etc.; fly... departments where certified products are prepared, handled, or stored. Docks and areas where cars and vehicles...

Electrochemical Testing of Ni-Cr-Mo-Gd Alloys

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

T. E. Lister; R. E. Mizia; H. Tian

2005-10-01

The waste package site recommendation design specified a boron-containing stainless steel, Neutronit 976/978, for fabrication of the internal baskets that will be used as a corrosion-resistant neutron-absorbing material. Recent corrosion test results gave higher-than-expected corrosion rates for this material. The material callout for these components has been changed to a Ni-Cr-Mo-Gd alloy (ASTM-B 932-04, UNS N06464) that is being developed at the Idaho National Laboratory. This report discusses the results of initial corrosion testing of this material in simulated in-package environments that could contact the fuel baskets after breach of the waste package outer barrier. The corrosion test matrix wasmore » executed using the potentiodynamic and potentiostatic electrochemical test techniques. The alloy performance shows low rates of general corrosion after initial removal of a gadolinium-rich second phase that intersects the surface. The high halide-containing test solutions exhibited greater tendencies toward initiation of crevice corrosion.« less

Fire-Resistant Reinforcement Makes Steel Structures Sturdier

NASA Technical Reports Server (NTRS)

2006-01-01

Built and designed by Avco Corporation, the Apollo heat shield was coated with an ablative material whose purpose was to burn and, thus, dissipate energy. The material charred to form a protective coating which blocked heat penetration beyond the outer surface. Avco Corporation subsequently entered into a contract with Ames Research Center to develop spinoff applications of the heat shield in the arena of fire protection, specifically for the development of fire-retardant paints and foams for aircraft. This experience led to the production of Chartek 59, manufactured by Avco Specialty Materials (a subsidiary of Avco Corporation eventually acquired by Textron, Inc.) and marketed as the world s first intumescent epoxy material. As an intumescent coating, Chartek 59 expanded in volume when exposed to heat or flames and acted as an insulating barrier. It also retained its space-age ablative properties and dissipated heat through burn-off. Further applications were discovered, and the fireproofing formulation found its way into oil refineries, chemical plants, and other industrial facilities working with highly flammable products.

Structural basis for maintenance of bacterial outer membrane lipid asymmetry.

PubMed

Abellón-Ruiz, Javier; Kaptan, Shreyas S; Baslé, Arnaud; Claudi, Beatrice; Bumann, Dirk; Kleinekathöfer, Ulrich; van den Berg, Bert

2017-12-01

The Gram-negative bacterial outer membrane (OM) is a unique bilayer that forms an efficient permeation barrier to protect the cell from noxious compounds 1 , 2 . The defining characteristic of the OM is lipid asymmetry, with phospholipids comprising the inner leaflet and lipopolysaccharides comprising the outer leaflet 1-3 . This asymmetry is maintained by the Mla pathway, a six-component system that is widespread in Gram-negative bacteria and is thought to mediate retrograde transport of misplaced phospholipids from the outer leaflet of the OM to the cytoplasmic membrane 4 . The OM lipoprotein MlaA performs the first step in this process via an unknown mechanism that does not require external energy input. Here we show, using X-ray crystallography, molecular dynamics simulations and in vitro and in vivo functional assays, that MlaA is a monomeric α-helical OM protein that functions as a phospholipid translocation channel, forming a ~20-Å-thick doughnut embedded in the inner leaflet of the OM with a central, amphipathic pore. This architecture prevents access of inner leaflet phospholipids to the pore, but allows outer leaflet phospholipids to bind to a pronounced ridge surrounding the channel, followed by diffusion towards the periplasmic space. Enterobacterial MlaA proteins form stable complexes with OmpF/C 5,6 , but the porins do not appear to play an active role in phospholipid transport. MlaA represents a lipid transport protein that selectively removes outer leaflet phospholipids to help maintain the essential barrier function of the bacterial OM.

A Multi-Level Examination of Stakeholder Perspectives of Implementation of Evidence-Based Practices in a Large Urban Publicly-Funded Mental Health System

PubMed Central

Beidas, Rinad S.; Stewart, Rebecca E.; Adams, Danielle R.; Fernandez, Tara; Lustbader, Susanna; Powell, Byron J.; Aarons, Gregory; Hoagwood, Kimberly E.; Evans, Arthur C.; Hurford, Matthew O.; Rubin, Ronnie; Hadley, Trevor; Mandell, David; Barg, Frances

2015-01-01

Our goal was to identify barriers and facilitators to the implementation of evidence-based practices from the perspectives of multiple stakeholders in a large publicly funded mental health system. We completed 56 interviews with three stakeholder groups: treatment developers (n = 7), agency administrators (n = 33), and system leadership (n = 16). The three stakeholder groups converged on the importance of inner (e.g., agency competing resources and demands, therapist educational background) and outer context (e.g., funding) factors as barriers to implementation. Potential threats to implementation and sustainability included the fiscal landscape of community mental health clinics and an evolving workforce. Intervention characteristics were rarely endorsed as barriers. Inner context, outer context, and intervention characteristics were all seen as important facilitators. All stakeholders endorsed the importance of coordinated collaboration across stakeholder groups within the system to successfully implement evidence-based practices. PMID:26658692

Spacecraft outer thermal blankets as hypervelocity impact bumpers

NASA Astrophysics Data System (ADS)

Cour-Palais, B. G.

1996-05-01

A thermal barrier consisting of a woven fabric outer layer followed by several layers of aluminized mylar insulation has been the primary impact protection against micrometeoroid and orbital impacts for many spacecraft currently in orbit. This paper examines its effectiveness as a hypervelocity "bumper" based on the performance of a NASA space suit. In this case, the thermal barrier consisted of a fabric layer followed by five layers of the aluminized mylar, which shielded either an aluminum rear wall or a rubberized pressure garment. The total areal density of the fabric and mylar layers was 0.052 g/cm2 and the fabric stand-off was 4 mm from the protected surfaces, with the aluminized mylar filling the space. Test results obtained with hypervelocity aluminum projectile impacts up to 8.5 km/s on the thermal barrier and aluminum wall are described, and a semi-empirical equation for this type of shielding is suggested.

High Temperature Degradation of Advanced Thermal and Environmental Barrier Coatings (TEBCs) by CaO-MgO-Al2O3-SiO2 (CMAS)

NASA Technical Reports Server (NTRS)

Costa, Gustavo; Zhu, Dongming

2017-01-01

There is increasing interest in the degradation studies of thermal and environmental barrier coatings (TEBCs) of gas turbines by molten CaO-MgO-Al2O3-SiO2 (CMAS). CMAS minerals are usually referred as silica-containing sand dust and volcano ash materials that are carried by the intake air into gas turbines, e.g. aircraft engines. The low-melting deposits react at high temperatures (1000C) with the coating materials. This causes degradation and accelerated coating failure of the static and rotating components of the turbine engines. We discuss some preliminary results of the reactions between CMAS and Rare-Earth (RE Y, Yb, Dy, Gd, Nd and Sm) oxide stabilized ZrO2 or HfO2 systems, and the stability of the resulting oxides and silicates. Plasma sprayed hollow tube samples (outer diameter 4.7 mm, wall thickness 0.76 mm and 26 mm height) were half filled with CMAS powder, wrapped and sealed with platinum foil, and heat- treated at 1310 C for 5h. Samples were characterized by differential scanning calorimetry, X-ray diffraction and cross section electron microscopy analysis.

Experimental Design for Evaluation of Co-extruded Refractory Metal/Nickel Base Superalloy Joints

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

ME Petrichek

2005-12-16

Prior to the restructuring of the Prometheus Program, the NRPCT was tasked with delivering a nuclear space reactor. Potential NRPCT nuclear space reactor designs for the Prometheus Project required dissimilar materials to be in contact with each other while operating at extreme temperatures under irradiation. As a result of the high reactor core temperatures, refractory metals were the primary candidates for many of the reactor structural and cladding components. They included the tantalum-base alloys ASTAR-811C and Ta-10W, the niobium-base alloy FS-85, and the molybdenum base alloys Moly 41-47.5 Rhenium. The refractory metals were to be joined to candidate nickel basemore » alloys such as Haynes 230, Alloy 617, or Nimonic PE 16 either within the core if the nickel-base alloys were ultimately selected to form the outer core barrel, or at a location exterior to the core if the nickel-base alloys were limited to components exterior to the core. To support the need for dissimilar metal joints in the Prometheus Project, a co-extrusion experiment was proposed. There are several potential methods for the formation of dissimilar metal joints, including explosive bonding, friction stir welding, plasma spray, inertia welding, HIP, and co-extrusion. Most of these joining methods are not viable options because they result in the immediate formation of brittle intermetallics. Upon cooling, intermetallics form in the weld fusion zone between the joined metals. Because brittle intermetallics do not form during the initial bonding process associated with HIP, co-extrusion, and explosive bonding, these three joining procedures are preferred for forming dissimilar metal joints. In reference to a Westinghouse Astronuclear Laboratory report done under a NASA sponsored program, joints that were fabricated between similar materials via explosive bonding had strengths that were directly affected by the width of the diffusion barrier. It was determined that the diffusion zone should not exceed a critical thickness (0.0005 in.). A diffusion barrier that exceeded this thickness would likely fail. The joint fabrication method must therefore mechanically bond the two materials causing little or no interdiffusion upon formation. Co-extrusion fits this description since it forms a mechanical joint between two materials by using heat and pressure. The two materials to be extruded are first assembled and sealed within a co-extrusion billet which is subsequently heated and then extruded through a die. For a production application, once the joint is formed, it is dejacketed to remove the outer canister. The remaining piece consists of two materials bonded together with a thin diffusion barrier. Therefore, the long-term stability of the joint is determined primarily by the kinetics of interdiffusion reaction between the two materials. An experimental design for co-extrusion of refractory metals and nickel-based superalloys was developed to evaluate this joining process and determine the long-term stability of the joints.« less

Profound re-organization of cell surface proteome in equine retinal pigment epithelial cells in response to in vitro culturing.

PubMed

Szober, Christoph M; Hauck, Stefanie M; Euler, Kerstin N; Fröhlich, Kristina J H; Alge-Priglinger, Claudia; Ueffing, Marius; Deeg, Cornelia A

2012-10-31

The purpose of this study was to characterize the cell surface proteome of native compared to cultured equine retinal pigment epithelium (RPE) cells. The RPE plays an essential role in visual function and represents the outer blood-retinal barrier. We are investigating immunopathomechanisms of equine recurrent uveitis, an autoimmune inflammatory disease in horses leading to breakdown of the outer blood-retinal barrier and influx of autoreactive T-cells into affected horses' vitrei. Cell surface proteins of native and cultured RPE cells from eye-healthy horses were captured by biotinylation, analyzed by high resolution mass spectrometry coupled to liquid chromatography (LC MS/MS), and the most interesting candidates were validated by PCR, immunoblotting and immunocytochemistry. A total of 112 proteins were identified, of which 84% were cell surface membrane proteins. Twenty-three of these proteins were concurrently expressed by both cell states, 28 proteins exclusively by native RPE cells. Among the latter were two RPE markers with highly specialized RPE functions: cellular retinaldehyde-binding protein (CRALBP) and retinal pigment epithelium-specific protein 65kDa (RPE65). Furthermore, 61 proteins were only expressed by cultured RPE cells and absent in native cells. As we believe that initiating events, leading to the breakdown of the outer blood-retinal barrier, take place at the cell surface of RPE cells as a particularly exposed barrier structure, this differential characterization of cell surface proteomes of native and cultured equine RPE cells is a prerequisite for future studies.

Thermal insulating conformal blanket

NASA Technical Reports Server (NTRS)

Barney, Andrea (Inventor); Whittington, Charles A (Inventor); Eilertson, Bryan (Inventor); Siminski, Zenon (Inventor)

2003-01-01

The conformal thermal insulating blanket may have generally rigid batting material covered by an outer insulating layer formed of a high temperature resistant woven ceramic material and an inner insulating layer formed of a woven ceramic fiber material. The batting and insulating layers may be fastened together by sewing or stitching using an outer mold layer thread fabricated of a high temperature resistant material and an inner mold layer thread of a ceramic fiber material. The batting may be formed to a composite structure that may have a firmness factor sufficient to inhibit a pillowing effect after the stitching to not more than 0.03 inch. The outer insulating layer and an upper portion of the batting adjacent the outer insulating layer may be impregnated with a ceramic coating material.

Method of Fault Detection and Rerouting

NASA Technical Reports Server (NTRS)

Gibson, Tracy L. (Inventor); Medelius, Pedro J. (Inventor); Lewis, Mark E. (Inventor)

2013-01-01

A system and method for detecting damage in an electrical wire, including delivering at least one test electrical signal to an outer electrically conductive material in a continuous or non-continuous layer covering an electrically insulative material layer that covers an electrically conductive wire core. Detecting the test electrical signals in the outer conductive material layer to obtain data that is processed to identify damage in the outer electrically conductive material layer.

ROCK-1 mediates diabetes-induced retinal pigment epithelial and endothelial cell blebbing: Contribution to diabetic retinopathy.

PubMed

Rothschild, Pierre-Raphaël; Salah, Sawsen; Berdugo, Marianne; Gélizé, Emmanuelle; Delaunay, Kimberley; Naud, Marie-Christine; Klein, Christophe; Moulin, Alexandre; Savoldelli, Michèle; Bergin, Ciara; Jeanny, Jean-Claude; Jonet, Laurent; Arsenijevic, Yvan; Behar-Cohen, Francine; Crisanti, Patricia

2017-08-18

In diabetic retinopathy, the exact mechanisms leading to retinal capillary closure and to retinal barriers breakdown remain imperfectly understood. Rho-associated kinase (ROCK), an effector of the small GTPase Rho, involved in cytoskeleton dynamic regulation and cell polarity is activated by hyperglycemia. In one year-old Goto Kakizaki (GK) type 2 diabetic rats retina, ROCK-1 activation was assessed by its cellular distribution and by phosphorylation of its substrates, MYPT1 and MLC. In both GK rat and in human type 2 diabetic retinas, ROCK-1 is activated and associated with non-apoptotic membrane blebbing in retinal vessels and in retinal pigment epithelium (RPE) that respectively form the inner and the outer barriers. Activation of ROCK-1 induces focal vascular constrictions, endoluminal blebbing and subsequent retinal hypoxia. In RPE cells, actin cytoskeleton remodeling and membrane blebs in RPE cells contributes to outer barrier breakdown. Intraocular injection of fasudil, significantly reduces both retinal hypoxia and RPE barrier breakdown. Diabetes-induced cell blebbing may contribute to ischemic maculopathy and represent an intervention target.

Planar ceramic membrane assembly and oxidation reactor system

DOEpatents

Carolan, Michael Francis; Dyer, legal representative, Kathryn Beverly; Wilson, Merrill Anderson; Ohm, Ted R.; Kneidel, Kurt E.; Peterson, David; Chen, Christopher M.; Rackers, Keith Gerard; Dyer, deceased, Paul Nigel

2007-10-09

Planar ceramic membrane assembly comprising a dense layer of mixed-conducting multi-component metal oxide material, wherein the dense layer has a first side and a second side, a porous layer of mixed-conducting multi-component metal oxide material in contact with the first side of the dense layer, and a ceramic channeled support layer in contact with the second side of the dense layer. The planar ceramic membrane assembly can be used in a ceramic wafer assembly comprising a planar ceramic channeled support layer having a first side and a second side; a first dense layer of mixed-conducting multi-component metal oxide material having an inner side and an outer side, wherein the inner side is in contact with the first side of the ceramic channeled support layer; a first outer support layer comprising porous mixed-conducting multi-component metal oxide material and having an inner side and an outer side, wherein the inner side is in contact with the outer side of the first dense layer; a second dense layer of mixed-conducting multi-component metal oxide material having an inner side and an outer side, wherein the inner side is in contact with the second side of the ceramic channeled layer; and a second outer support layer comprising porous mixed-conducting multi-component metal oxide material and having an inner side and an outer side, wherein the inner side is in contact with the outer side of the second dense layer.

Planar ceramic membrane assembly and oxidation reactor system

DOEpatents

Carolan, Michael Francis; Dyer, legal representative, Kathryn Beverly; Wilson, Merrill Anderson; Ohrn, Ted R.; Kneidel, Kurt E.; Peterson, David; Chen, Christopher M.; Rackers, Keith Gerard; Dyer, Paul Nigel

2009-04-07

Planar ceramic membrane assembly comprising a dense layer of mixed-conducting multi-component metal oxide material, wherein the dense layer has a first side and a second side, a porous layer of mixed-conducting multi-component metal oxide material in contact with the first side of the dense layer, and a ceramic channeled support layer in contact with the second side of the dense layer. The planar ceramic membrane assembly can be used in a ceramic wafer assembly comprising a planar ceramic channeled support layer having a first side and a second side; a first dense layer of mixed-conducting multi-component metal oxide material having an inner side and an outer side, wherein the inner side is in contact with the first side of the ceramic channeled support layer; a first outer support layer comprising porous mixed-conducting multi-component metal oxide material and having an inner side and an outer side, wherein the inner side is in contact with the outer side of the first dense layer; a second dense layer of mixed-conducting multi-component metal oxide material having an inner side and an outer side, wherein the inner side is in contact with the second side of the ceramic channeled layer; and a second outer support layer comprising porous mixed-conducting multi-component metal oxide material and having an inner side and an outer side, wherein the inner side is in contact with the outer side of the second dense layer.

Morphological and chemical changes of aerosolized E. coli treated with a dielectric barrier discharge

DOE PAGES

Romero-Mangado, Jaione; Nordlund, Dennis; Soberon, Felipe; ...

2016-02-12

This paper presents the morphological and chemical modification of the cell structure of aerosolized Escherichia coli treated with a dielectric barrier discharge (DBD). Exposure to DBD results in severe oxidation of the bacteria, leading to the formation of hydroxyl groups and carbonyl groups and a significant reduction in amine functionalities and phosphate groups. Near edge x-ray absorption fine structure(NEXAFS) measurements confirm the presence of additional oxide bonds upon DBD treatment, suggesting oxidation of the outer layer of the cell wall. Electron microscopy images show that the bacteria undergo physical distortion to varying degrees, resulting in deformation of the bacterial structure.more » The electromagnetic field around the DBD coil causes severe damage to the cell structure, possibly resulting in leakage of vital cellular materials. The oxidation and chemical modification of the bacterial components are evident from the Fourier transform infrared spectroscopy and NEXAFS results. The bacterial reculture experiments confirm inactivation of airborne E. coli upon treating with DBD.« less

Thermal Insulation System for Non-Vacuum Applications Including a Multilayer Composite

NASA Technical Reports Server (NTRS)

Fesmire, James E. (Inventor)

2017-01-01

The thermal insulation system of the present invention is for non-vacuum applications and is specifically tailored to the ambient pressure environment with any level of humidity or moisture. The thermal insulation system includes a multilayered composite including i) at least one thermal insulation layer and at least one compressible barrier layer provided as alternating, successive layers, and ii) at least one reflective film provided on at least one surface of the thermal insulation layer and/or said compressible barrier layer. The different layers and materials and their combinations are designed to provide low effective thermal conductivity for the system by managing all modes of heat transfer. The thermal insulation system includes an optional outer casing surrounding the multilayered composite. The thermal insulation system is particularly suited for use in any sub-ambient temperature environment where moisture or its adverse effects are a concern. The thermal insulation system provides physical resilience against damaging mechanical effects including compression, flexure, impact, vibration, and thermal expansion/contraction.

Composite Pressure Vessel Including Crack Arresting Barrier

NASA Technical Reports Server (NTRS)

DeLay, Thomas K. (Inventor)

2013-01-01

A pressure vessel includes a ported fitting having an annular flange formed on an end thereof and a tank that envelopes the annular flange. A crack arresting barrier is bonded to and forming a lining of the tank within the outer surface thereof. The crack arresting barrier includes a cured resin having a post-curing ductility rating of at least approximately 60% through the cured resin, and further includes randomly-oriented fibers positioned in and throughout the cured resin.

Development of sputtered techniques for thrust chambers

NASA Technical Reports Server (NTRS)

Mullaly, J. R.; Hecht, R. J.; Schmid, T. E.; Torrey, C. T.

1975-01-01

Techniques and materials were developed and evaluated for the fabrication and coating of advanced, long life, regeneratively cooled thrust chambers. Materials were analyzed as fillers for sputter application of OFHC copper as a closeout layer to channeled inner structures; of the materials evaluated, aluminum was found to provide the highest bond strength and to be the most desirable for chamber fabrication. The structures and properties were investigated of thick sputtered OFHC copper, 0.15 Zr-Cu, Al2O3,-Cu, and SiC-Cu. Layered structures of OFHC copper and 0.15 Zr-Cu were investigated as means of improving chamber inner wall fatigue life. The evaluation of sputtered Ti-5Al-2.5Sn, NASA IIb-11, aluminum and Al2O3-Al alloys as high strength chamber outer jackets was performed. Techniques for refurbishing degraded thrust chambers with OFHC copper and coating thrust chambers with protective ZrO2 and graded ZrO2-copper thermal barrier coatings were developed.

Electron beam selectively seals porous metal filters

NASA Technical Reports Server (NTRS)

Snyder, J. A.; Tulisiak, G.

1968-01-01

Electron beam welding selectively seals the outer surfaces of porous metal filters and impedances used in fluid flow systems. The outer surface can be sealed by melting a thin outer layer of the porous material with an electron beam so that the melted material fills all surface pores.

Analytical investigation of thermal barrier coatings for advanced power generation combustion turbines

NASA Technical Reports Server (NTRS)

Amos, D. J.

1977-01-01

An analytical evaluation was conducted to determine quantitatively the improvement potential in cycle efficiency and cost of electricity made possible by the introduction of thermal barrier coatings to power generation combustion turbine systems. The thermal barrier system, a metallic bond coat and yttria stabilized zirconia outer layer applied by plasma spray techniques, acts as a heat insulator to provide substantial metal temperature reductions below that of the exposed thermal barrier surface. The study results show the thermal barrier to be a potentially attractive means for improving performance and reducing cost of electricity for the simple, recuperated, and combined cycles evaluated.

Promoting mechanism of N-doped single-walled carbon nanotubes for O2 dissociation and SO2 oxidation

NASA Astrophysics Data System (ADS)

Chen, Yanqiu; Yin, Shi; Chen, Yang; Cen, Wanglai; Li, Jianjun; Yin, Huaqiang

2018-03-01

Although heteroatom doping in carbon based catalysts have recently received intensive attentions, the role of the intrinsically porous structure of practical carbon materials and their potential synergy with doping atoms are still unclear. To investigate the complex effects, a range of N-doped single-walled carbon nanotubes (SWCNTs) were used to investigate their potential use for O2 dissociation and the subsequent SO2 oxidation using density functional theory. It is found that graphite N doping can synergize with the outer surface of SWCNTs to facilitate the dissociation of O2. The barrier for the dissociation on dual graphite N-doped SWCNT-(8, 8) is as low as 0.3 eV, and the subsequent SO2 oxidation is thermodynamically favorable and kinetically feasible. These results spotlight on developing promising carboncatalyst via utilization of porous gemometry and heteroatom-doping of carbon materials simultaneously.

A Multi-Level Examination of Stakeholder Perspectives of Implementation of Evidence-Based Practices in a Large Urban Publicly-Funded Mental Health System.

PubMed

Beidas, Rinad S; Stewart, Rebecca E; Adams, Danielle R; Fernandez, Tara; Lustbader, Susanna; Powell, Byron J; Aarons, Gregory A; Hoagwood, Kimberly E; Evans, Arthur C; Hurford, Matthew O; Rubin, Ronnie; Hadley, Trevor; Mandell, David S; Barg, Frances K

2016-11-01

Our goal was to identify barriers and facilitators to the implementation of evidence-based practices from the perspectives of multiple stakeholders in a large publicly funded mental health system. We completed 56 interviews with three stakeholder groups: treatment developers (n = 7), agency administrators (n = 33), and system leadership (n = 16). The three stakeholder groups converged on the importance of inner (e.g., agency competing resources and demands, therapist educational background) and outer context (e.g., funding) factors as barriers to implementation. Potential threats to implementation and sustainability included the fiscal landscape of community mental health clinics and an evolving workforce. Intervention characteristics were rarely endorsed as barriers. Inner context, outer context, and intervention characteristics were all seen as important facilitators. All stakeholders endorsed the importance of coordinated collaboration across stakeholder groups within the system to successfully implement evidence-based practices.

Determination of Time Required for Materials Exposed to Oxygen to Return to Reduced Flammability

NASA Technical Reports Server (NTRS)

Harper, Susana; Hirsch, David; Smith, Sarah

2009-01-01

Increased material flammability due to exposure to high oxygen concentrations is a concern from both a safety and operational perspective. Localized, high oxygen concentrations can occur when exiting a higher oxygen concentration environment due to material saturation, as well as oxygen entrapment between barrier materials. Understanding of oxygen diffusion and permeation and its correlation to flammability risks can reduce the likelihood of fires while improving procedures as NASA moves to longer missions with increased extravehicular activities in both spacecraft and off-Earth habitats. This paper examines the time required for common spacecraft materials exposed to oxygen to return to reduced flammability after removal from the increased oxygen concentration environment. Specifically, NASA-STD-6001A maximum oxygen concentration testing and ASTM F-1927 permeability testing were performed on Nomex 4 HT90-40, Tiburon 5 Surgical Drape, Cotton, Extravehicular Mobility Unit (EMU) Liquid-Cooled Ventilation Garment, EMU Thermal Comfort Undergarment, EMU Mosite Foam with Spandex Covering, Advanced Crew Escape Suit (ACES) Outer Cross-section, ACES Liquid Cooled Garment (LCG), ACES O2 Hose Material, Minicel 6 Polyethylene Foam, Minicel Polyethylene Foam with Nomex Covering, Pyrell Polyurethane Foam, and Zotek 7 F-30 Foam.

The Outer Banks of North Carolina

USGS Publications Warehouse

Dolan, Robert; Lins, Harry F.; Smith, Jodi Jones

2016-12-27

The Outer Banks of North Carolina are excellent examples of the nearly 300 barrier islands rimming the Atlantic and Gulf coasts of the United States. These low, sandy islands are among the most dynamic natural landscapes occupied by man. Beach sands move offshore, onshore, and along the shore in the direction of the prevailing longshore currents. In this way, sandy coasts continuously adjust to different tide, wave, and current conditions and to rising sea level that causes the islands to migrate landward.Despite such changes, barrier islands are of considerable environmental importance. The Outer Banks are home to diverse natural ecosystems that are adapted to the harsh coastal environment. Native species tend to be robust and many are specifically adapted to withstand salt spray, periodic saltwater flooding, and the islands’ well-drained sandy soil. The Outer Banks provide an important stopover for birds on the Atlantic flyway, and many species inhabit the islands year round. In addition, Outer Banks beaches provide an important nesting habitat for five endangered or threatened sea turtle species.European explorers discovered North Carolina’s barrier islands in the 16th century, although the islands were not permanently settled until the middle 17th century. By the early 19th century, shipbuilding and lumber industries were among the most successful, until forest resources were depleted. Commercial fishing eventually followed, and it expanded considerably after the Civil War. By the Great Depression, however, little industry existed on the Outer Banks. In response to the effects of a severe hurricane in 1933, the National Park Service and the Civilian Conservation Corps proposed a massive sand-fixation program to stabilize the moving sand and prevent storm waves from sweeping across the entire width of some sections of the islands. Between 1933 and 1940, this program constructed sand fencing on 185 kilometers (115 miles) of beach and planted grass seedlings, trees, and shrubs.In 1937, Congress authorized the Cape Hatteras National Seashore, which was established in 1953. The national seashore preserved one of the world’s best examples of a barrier island environment, and minimized the effect of erosion that was becoming a serious problem. In 1966, Congress authorized the Cape Lookout National Seashore to ensure that Core and Shackleford Banks would not undergo major development and could be preserved in their natural state.The rate of population growth along the Outer Banks in recent decades has been among the highest in North Carolina. More important, however, has been the growth in vacationers—in 2008, more than a quarter of a million visitors during a typical week. Municipalities now need to provide services to a transient population as much as six times as large as their permanent resident population.Although human activities have dominated the landscape changes observed on the Outer Banks for the past century or two, these changes must be understood in the context of the prevailing atmospheric, oceanic, and geologic processes that have governed the form and function of these islands for thousands of years. It is these natural processes that imbue the Outer Banks with their unique and dichotomous qualities of tranquility and tumult. In the presence of human occupation, it is these same processes that make the islands one of the highest natural-hazard risk zones along the Eastern Seaboard of the United States.

Extracellular accumulation of recombinant protein by Escherichia coli in a defined medium.

PubMed

Fu, Xiang-Yang

2010-09-01

Extracellular accumulation of recombinant proteins in the culture medium of Escherichia coli is desirable but difficult to obtain. The inner or cytoplasmic membrane and the outer membrane of E. coli are two barriers for releasing recombinant proteins expressed in the cytoplasm into the culture medium. Even if recombinant proteins have been exported into the periplasm, a space between the outer membrane and the inner membrane, the outer membrane remains the last barrier for their extracellular release. However, when E. coli was cultured in a particular defined medium, recombinant proteins exported into the periplasm could diffuse into the culture medium automatically. If a nonionic detergent, Triton X-100, was added in the medium, recombinant proteins expressed in the cytoplasm could also be released into the culture medium. It was then that extracellular accumulation of recombinant proteins could be obtained by exporting them into the periplasm or releasing them from the cytoplasm with Triton X-100 addition. The tactics described herein provided simple and valuable methods for achieving extracellular production of recombinant proteins in E. coli.

Radation shielding pellets

DOEpatents

Coomes, Edmund P.; Luksic, Andrzej T.

1988-12-06

Radiation pellets having an outer shell, preferably, of Mo, W or depleted U nd an inner filling of lithium hydride wherein the outer shell material has a greater melting point than does the inner filling material.

Great Barrier Reef, Australia

NASA Image and Video Library

1996-01-20

STS072-727-085 (11-20 Jan. 1996) --- The northern third of the Great Barrier Reef stretches 650 kilometers (km) along the coast of Queensland from south of Cairns to past Princess Charlotte Bay at the base of the Cape York Peninsula. The predominant westerly waves of the ocean create shallower (lighter-colored) convex-eastward rims to coral atolls along the outer edge of the barrier reef. In contrast, islands within the lagoon show the effect of predominant southerly, more-or-less offshore winds. Arcuate clouds suggest that winds were offshore at the time the photograph was taken.

Solar thermochemical reactor, methods of manufacture and use thereof and thermogravimeter

DOEpatents

Klausner, James F.; Petrasch, Joerg

2017-06-06

A solar thermochemical reactor contains an outer member, an inner member disposed within an outer member, wherein the outer member surrounds the inner member and wherein the outer member has an aperture for receiving solar radiation. An inner cavity and an outer cavity are formed by the inner member and outer member and a reactive material that is capable of being magnetically stabilized is disposed in the outer cavity between the inner member and the outer member.

Integration of air separation membrane and coalescing filter for use on an inlet air system of an engine

DOEpatents

Moncelle, Michael E.

2003-01-01

An intake air separation system suitable for combustion air of an internal combustion engine. An air separation device of the system includes a plurality of fibers, each fiber having a tube with a permeation barrier layer on the outer surface thereof and a coalescing layer on the inner surface thereof, to restrict fluid droplets from contacting the permeation barrier layer.

Biochemical and molecular characterization of rice (Oryza sativa L.) roots forming a barrier to radial oxygen loss.

PubMed

Kulichikhin, Konstantin; Yamauchi, Takaki; Watanabe, Kohtaro; Nakazono, Mikio

2014-10-01

The formation of a barrier to radial oxygen (O2 ) loss (ROL) in the root is an important adaptation of plants to root flooding, but the biochemical changes in plant roots where the barrier is formed are unclear. In this study, we analysed metabolic profiles and gene expression profiles in roots of rice (Oryza sativa L.) plants grown under stagnant deoxygenated conditions, which induce suberization in the outer cell layers of the roots and formation of barrier to ROL. Under these conditions, two distinctive biochemical features of the roots were the accumulations of malic acid and very long chain fatty acids (VLCFAs). We also showed that the expressions of some genes encoding plastid-localized enzymes, which convert malic acid to acetyl coenzyme A (AcCoA), were simultaneously up-regulated under stagnant conditions. The expression levels of these genes in specific root tissues isolated by laser microdissection suggested that malic acid is converted to AcCoA predominantly in the plastids in the outer cell layers of rice roots. We propose that the physiological role of malic acid accumulation in rice roots grown under stagnant conditions is to provide a substrate for the biosynthesis of fatty acids, which, in turn, are used in the biosynthesis of suberin. © 2014 John Wiley & Sons Ltd.

Compound design guidelines for evading the efflux and permeation barriers of Escherichia coli with the oxazolidinone class of antibacterials: Test case for a general approach to improving whole cell Gram-negative activity.

PubMed

Spaulding, Andrew; Takrouri, Khuloud; Mahalingam, Pornachandran; Cleary, Dillon C; Cooper, Harold D; Zucchi, Paola; Tear, Westley; Koleva, Bilyana; Beuning, Penny J; Hirsch, Elizabeth B; Aggen, James B

2017-12-01

Previously we reported the results from an effort to improve Gram-negative antibacterial activity in the oxazolidinone class of antibiotics via a systematic medicinal chemistry campaign focused entirely on C-ring modifications. In that series we set about testing if the efflux and permeation barriers intrinsic to the outer membrane of Escherichia coli could be rationally overcome by designing analogs to reside in specific property limits associated with Gram-negative activity: i) low MW (<400), ii) high polarity (clogD 7.4 <1), and iii) zwitterionic character at pH 7.4. Indeed, we observed that only analogs residing within these limits were able to overcome these barriers. Herein we report the results from a parallel effort where we explored structural changes throughout all three rings in the scaffold for the same purpose. Compounds were tested against a diagnostic MIC panel of Escherichia coli and Staphylococcus aureus strains to determine the impact of combining structural modifications in overcoming the OM barriers and in bridging the potency gap between the species. The results demonstrated that distributing the charge-carrying moieties across two rings was also beneficial for avoidance of the outer membrane barriers. Importantly, analysis of the structure-permeation relationship (SPR) obtained from this and the prior study indicated that in addition to MW, polarity, and zwitterionic character, having ≤4 rotatable bonds is also associated with evasion of the OM barriers. These combined results provide the medicinal chemist with a framework and strategy for overcoming the OM barriers in GNB in antibacterial drug discovery efforts. Copyright © 2017. Published by Elsevier Ltd.

Fast modification on wheat straw outer surface by water vapor plasma and its application on composite material.

PubMed

Chen, Weimin; Xu, Yicheng; Shi, Shukai; Cao, Yizhong; Chen, Minzhi; Zhou, Xiaoyan

2018-02-02

The presence of non-poplar extracts, cutin, and wax layer in the wheat straw outer surface (WOS) greatly limit its application in bio-composite preparation. In this study, a dielectric-barrier-discharge plasma using water vapor as feeding gas was used to fast modify the WOS. The morphology, free radical concentrations, surface chemical components, and contact angles of WOS before and after plasma modification were investigated. Wheat straw was further prepared into wheat straw-based composites (WSC) and its bonding strength was evaluated by a paper tension meter. The results showed that water vapor plasma leads to the appearance of surface roughness, the generation of massive free radicals, and the introduction of oxygen-containing groups. In addition, both initial and equilibrium contact angle and the surface total free energy were significantly increased after plasma modification. These results synergistically facilitate the spread and permeation of adhesive onto the WOS and thus improve the bonding strength of all prepared WSCs. A good linear relationship between bonding strength and surface roughness parameters, contact angles, and total free energy were observed. In general, this study provided a time-saving and cost-effective modification method to realize WSC manufacture.

Difference in radiocarbon ages of carbonized material from the inner and outer surfaces of pottery from a wetland archaeological site.

PubMed

Miyata, Yoshiki; Minami, Masayo; Onbe, Shin; Sakamoto, Minoru; Matsuzaki, Hiroyuki; Nakamura, Toshio; Imamura, Mineo

2011-01-01

AMS (Accelerator Mass Spectrometry) radiocarbon dates for eight potsherds from a single piece of pottery from a wetland archaeological site indicated that charred material from the inner pottery surfaces (5052 ± 12 BP; N = 5) is about 90 (14)C years older than that from the outer surfaces (4961 ± 22 BP; N = 7). We considered three possible causes of this difference: the old wood effect, reservoir effects, and diagenesis. We concluded that differences in the radiocarbon ages between materials from the inner and outer surfaces of the same pot were caused either by the freshwater reservoir effect or by diagenesis. Moreover, we found that the radiocarbon ages of carbonized material on outer surfaces (soot) of pottery from other wetland archaeological sites were the same as the ages of material on inner surfaces (charred food) of the same pot within error, suggesting absence of freshwater reservoir effect or diagenesis.

Electromagnetic valve for controlling the flow of molten, magnetic material

DOEpatents

Richter, T.

1998-06-16

An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell. 5 figs.

Electromagnetic valve for controlling the flow of molten, magnetic material

DOEpatents

Richter, Tomas

1998-01-01

An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell.

9 CFR 355.15 - Inedible material operating and storage rooms; outer premises, docks, driveways, etc.; fly...

Code of Federal Regulations, 2010 CFR

2010-01-01

...-breeding material; nuisances. All operating and storage rooms and departments of inspected plants used for... storage rooms; outer premises, docks, driveways, etc.; fly-breeding material; nuisances. 355.15 Section... premises of every inspected plant shall be kept in clean and orderly condition. All catchbasins on the...

9 CFR 355.15 - Inedible material operating and storage rooms; outer premises, docks, driveways, etc.; fly...

Code of Federal Regulations, 2011 CFR

2011-01-01

...-breeding material; nuisances. All operating and storage rooms and departments of inspected plants used for... storage rooms; outer premises, docks, driveways, etc.; fly-breeding material; nuisances. 355.15 Section... premises of every inspected plant shall be kept in clean and orderly condition. All catchbasins on the...

Temperature control transport system

DOEpatents

Schabron, John F; Sorini-Wong, Susan S

2014-12-09

Embodiments of the inventive technology may involve the use of layered, insulated PCM assemblage that itself comprises: modular insulating foam material 8 that, upon establishment as part of the assemblage, defines inner foam material sides 9 and outer foam material sides 10; thin reflective material 11 established against (whether directly in contact with or not) at least either the inner foam material sides or the outer foam materials sides, and modular, enclosed PCM sections 12 established between the modular insulating foam material and the interior center.

Barrier Requirements as the Evolutionary “Driver” of Epidermal Pigmentation in Humans

PubMed Central

ELIAS, PETER M.; MENON, GOPINATHAN; WETZEL, BRUCE K.; WILLIAMS, JOHN (JACK) W.

2011-01-01

Current explanations for the development of epidermal pigmentation during human evolution are not tenable as stand-alone hypotheses. Accordingly, we assessed instead whether xeric- and UV-B-induced stress to the epidermal permeability barrier, critical to survival in a terrestrial environment, could have “driven” the development of epidermal pigmentation. (1) Megadroughts prevailed in central Africa when hominids expanded into open savannahs [≈1.5–0.8 million years ago], resulting in sustained exposure to both extreme aridity and erythemogenic UV-B, correlating with genetic evidence that pigment developed ≈1.2 million years ago. (2) Pigmented skin is endowed with enhanced permeability barrier function, stratum corneum integrity/cohesion, and a reduced susceptibility to infections. The enhanced function of pigmented skin can be attributed to the lower pH of the outer epidermis, likely due to the persistence of (more-acidic) melanosomes into the outer epidermis, as well as the conservation of genes associated with eumelanin synthesis and melanosome acidification (e.g., TYR, OCA2 [p protein], SLC24A5, SLC45A2, MATP) in pigmented populations. Five keratinocyte-derived signals (stem cell factor⇒KIT; FOXn1⇒FGF2; IL-1α, NGF, and p53) are potential candidates to have stimulated the sequential development of epidermal pigmentation in response to stress to the barrier. We summarize evidence here that epidermal interfollicular pigmentation in early hominids likely evolved in response to stress to the permeability barrier. PMID:20209486

Turbine airfoil with outer wall thickness indicators

DOEpatents

Marra, John J; James, Allister W; Merrill, Gary B

2013-08-06

A turbine airfoil usable in a turbine engine and including a depth indicator for determining outer wall blade thickness. The airfoil may include an outer wall having a plurality of grooves in the outer surface of the outer wall. The grooves may have a depth that represents a desired outer surface and wall thickness of the outer wall. The material forming an outer surface of the outer wall may be removed to be flush with an innermost point in each groove, thereby reducing the wall thickness and increasing efficiency. The plurality of grooves may be positioned in a radially outer region of the airfoil proximate to the tip.

Bacterial RNA isolation.

PubMed

Ares, Manuel

2012-09-01

In this bacterial RNA isolation protocol, an "RNA-protective" treatment is followed by lysozyme digestion of the peptidoglycan component of the cell wall. EDTA promotes the loss of the outer membrane of Gram-negative bacteria and allows the lysozyme better access to the peptidoglycan. Cells begin to lyse during digestion in hypotonic lysozyme buffer and lysis is completed by sodium dodecyl sulfate (SDS) and hot phenol:chloroform:isoamyl alcohol (PCA) extraction. SDS and hot phenol disrupt membranes, denature protein (including RNase), and strip proteins from RNA. The separation of the organic phase from the aqueous phase is achieved using Phase Lock Gel, an inert material with a density intermediate between the organic and aqueous samples. The sample is split into three phases: from bottom to top, these are phenol and chloroform (organic phase), the inert gel with the interface material, and the aqueous phase with the RNA. The gel acts as a physical barrier between the sample and the organic phase plus interface. Following organic extraction, the RNA is concentrated by ethanol precipitation.

Bacterial communities in Great Barrier Reef calcareous sediments: Contrasting 16S rDNA libraries from nearshore and outer shelf reefs

NASA Astrophysics Data System (ADS)

Uthicke, S.; McGuire, K.

2007-03-01

Bacterial communities in eight 16S rDNA clone libraries from calcareous sediments were investigated to provide an assessment of the bacterial diversity on sediments of the Great Barrier Reef (GBR) and to investigate differences due to decreased water quality. Sample effort was spread across two locations on each of four coral reefs, with two reefs located nearshore and two reefs on the outer shelf to allow robust statistical comparison of nearshore reefs (subjected to enhanced runoff) and outer shelf reefs (pristine conditions). Out of 221 non-chimeric sequences, 189 (85.5%) were unique and only one sequence occurred in more than one library. Rarefaction analyses and coverage calculations indicated that only a small fraction of the diversity was sampled. Cluster analyses and comparison to published sequences indicated that sequences retrieved belonged to the α, γ and δ subdivision of the Proteobacteria (6.8, 29.4 and 13.6% of the total, respectively), Cytophaga-Flavobacteria-Bacteroidetes (CFB) group (20.4%), Cyanobacteria (5.4%), Planctomycetaceae (7.7%), Verrucomicrobiaceae (6.8%), Acidobacteriaceae (2.7%). Analysis of Similarity (ANOSIM, based on grouping all retrieved sequences into 9 phylogenetic groups) indicated that subtle differences do exist in the community composition between nearshore and outer shelf reefs. Similarity percentage analysis (SIMPER) indicated that Acidobacteriaceae and Cyanobacteriaceae were the main contributors to the dissimilarity. A significant difference between bacteria on nearshore and outer shelf reefs also existed on the molecular level ( FST = 0.008, p = 0.007 for all samples, 0.006, p = 0.022 when repeated sequences within libraries were removed). Thus, bacterial communities on carbonate sediments investigated were highly diverse and differences in community composition may provide important leads for the search for indicator species or communities for water quality differences.

Sprayed skin turbine component

DOEpatents

Allen, David B

2013-06-04

Fabricating a turbine component (50) by casting a core structure (30), forming an array of pits (24) in an outer surface (32) of the core structure, depositing a transient liquid phase (TLP) material (40) on the outer surface of the core structure, the TLP containing a melting-point depressant, depositing a skin (42) on the outer surface of the core structure over the TLP material, and heating the assembly, thus forming both a diffusion bond and a mechanical interlock between the skin and the core structure. The heating diffuses the melting-point depressant away from the interface. Subsurface cooling channels (35) may be formed by forming grooves (34) in the outer surface of the core structure, filling the grooves with a fugitive filler (36), depositing and bonding the skin (42), then removing the fugitive material.

Treatment of Gram-negative bacterial infections by potentiation of antibiotics.

PubMed

Zabawa, Thomas P; Pucci, Michael J; Parr, Thomas R; Lister, Troy

2016-10-01

Infections caused by antibiotic-resistant pathogens, particularly Gram-negative bacteria, represent significant treatment challenges for physicians resulting in high rates of morbidity and mortality. The outer membrane of Gram-negative bacteria acts as a permeability barrier to many compounds that would otherwise be effective antibacterial agents, including those effective against Gram-positive pathogens. Potentiator molecules disrupt this barrier allowing entry of otherwise impermeant molecules, thus providing a strategy to render multi-drug resistant pathogens susceptible to a broader range of antibiotics. Potentiator molecules are cationic and the mechanism of disruption involves interaction with the negatively charged outer membrane. This physical attribute, along with an often high degree of lipophilicity typically endears these molecules with unacceptable toxicity. Presented herein are examples of advanced potentiator molecules being evaluated for use in combination therapy for the treatment of resistant Gram-negative infections. Copyright © 2016 Elsevier Ltd. All rights reserved.

46 CFR 154.170 - Outer hull steel plating.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the outer hull steel plating, including the shell and deck plating must meet the material standards of the... 46 Shipping 5 2014-10-01 2014-10-01 false Outer hull steel plating. 154.170 Section 154.170...

46 CFR 154.170 - Outer hull steel plating.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the outer hull steel plating, including the shell and deck plating must meet the material standards of the... 46 Shipping 5 2012-10-01 2012-10-01 false Outer hull steel plating. 154.170 Section 154.170...

46 CFR 154.170 - Outer hull steel plating.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Structure § 154.170 Outer hull steel plating. (a) Except as required in paragraph (b) of this section, the outer hull steel plating, including the shell and deck plating must meet the material standards of the... 46 Shipping 5 2013-10-01 2013-10-01 false Outer hull steel plating. 154.170 Section 154.170...

Coated woven materials and method of preparation

DOEpatents

McCreary, W.J.; Carroll, D.W.

Coating of woven materials so that not only the outer surfaces are coated has been a problem. Now, a solution to that problem is by coating with materials, with metals or with pyrolytic carbon. Materials are deposited in Chemical Vapor Deposition (CND) reactions using a fluidized bed so that the porosity of the woven materials is retained and the tiny filaments which make up the strands which are woven (including inner as well as outer filaments) are substantially uniformly coated.

Valve assembly for use with high temperature and high pressure fluids

DOEpatents

De Feo, Angelo

1982-01-01

The valve assembly for use with high temperature and high pressure fluids has inner and outer spaced shells and a valve actuator support of inner and outer spaced members which are connected at their end portions to the inner and outer shells, respectively, to extend substantially normal to the longitudinal axis of the inner shell. A layer of resilient heat insulating material covers the outer surfaces of the inner shell and the inner actuator support member and is of a thickness to only occupy part of the spaces between the inner and outer shells and inner and outer actuator support members. The remaining portion of the space between the inner and outer shells and the space between the inner and outer members is substantially filled with a body of castable, rigid refractory material. A movable valve member is disposed in the inner shell. A valve actuator assembly is supported in the valve actuator support to extend into the inner shell for connection with the movable valve member for movement of the movable valve member to positions from a fully open to a fully closed position to control flow of fluid through the inner shell. An anchor mneans is disposed adjacent opposite sides of the axis of the valve actuator support and attached to the inner shell so that relative radial movement between the inner and outer shell is permitted by the layer of resilient heat insulating material and relative longitudinal movement of the inner shell to the outer shell is permitted in opposite directions from the anchor means to thereby maintain the functional integrity of the movable valve member by providing an area of the inner shell surrounding the movable valve member longitdinally stationary, but at the same time allowing radial movement.

A sphingolipid-dependent diffusion barrier confines ER stress to the yeast mother cell

PubMed Central

Clay, Lori; Caudron, Fabrice; Denoth-Lippuner, Annina; Boettcher, Barbara; Buvelot Frei, Stéphanie; Snapp, Erik Lee; Barral, Yves

2014-01-01

In many cell types, lateral diffusion barriers compartmentalize the plasma membrane and, at least in budding yeast, the endoplasmic reticulum (ER). However, the molecular nature of these barriers, their mode of action and their cellular functions are unclear. Here, we show that misfolded proteins of the ER remain confined into the mother compartment of budding yeast cells. Confinement required the formation of a lateral diffusion barrier in the form of a distinct domain of the ER-membrane at the bud neck, in a septin-, Bud1 GTPase- and sphingolipid-dependent manner. The sphingolipids, but not Bud1, also contributed to barrier formation in the outer membrane of the dividing nucleus. Barrier-dependent confinement of ER stress into the mother cell promoted aging. Together, our data clarify the physical nature of lateral diffusion barriers in the ER and establish the role of such barriers in the asymmetric segregation of proteotoxic misfolded proteins during cell division and aging. DOI: http://dx.doi.org/10.7554/eLife.01883.001 PMID:24843009

49 CFR 178.802 - Preparation of fiberboard IBCs for testing.

Code of Federal Regulations, 2010 CFR

2010-10-01

... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS... IBCs and composite IBCs with fiberboard outer packagings must be conditioned for at least 24 hours in..., fiberboard IBCs or composite IBCs with fiberboard outer packagings may be at ambient conditions. [Amdt. 178...

Recirculating electric air filter

DOEpatents

Bergman, Werner

1986-01-01

An electric air filter cartridge has a cylindrical inner high voltage eleode, a layer of filter material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert filter material. Air flows through the two electrodes and the filter material and is exhausted from the center of the inner electrode.

The processing of materials in outer space

NASA Technical Reports Server (NTRS)

Gelles, S. H.; Colling, E. W.

1977-01-01

Zero-gravity environment may lead to fabrication of new and improved materials. According to comprehensive study of application of this promising technology to superconducting and electrical contact materials, outer space processing could improve microstructure and homogeneity of many single and multicomponent systems formed from solidification of fluid phases. New structures that are impossible to form terrestrially may also be accessible in space environment.

Recirculating electric air filter

DOEpatents

Bergman, W.

1985-01-09

An electric air filter cartridge has a cylindrical inner high voltage electrode, a layer of filter material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert filter material. Air flows through the two electrodes and the filter material and is exhausted from the center of the inner electrode.

Puncture detecting barrier materials

DOEpatents

Hermes, R.E.; Ramsey, D.R.; Stampfer, J.F.; Macdonald, J.M.

1998-03-31

A method and apparatus for continuous real-time monitoring of the integrity of protective barrier materials, particularly protective barriers against toxic, radioactive and biologically hazardous materials has been developed. Conductivity, resistivity or capacitance between conductive layers in the multilayer protective materials is measured by using leads connected to electrically conductive layers in the protective barrier material. The measured conductivity, resistivity or capacitance significantly changes upon a physical breach of the protective barrier material. 4 figs.

Puncture detecting barrier materials

DOEpatents

Hermes, Robert E.; Ramsey, David R.; Stampfer, Joseph F.; Macdonald, John M.

1998-01-01

A method and apparatus for continuous real-time monitoring of the integrity of protective barrier materials, particularly protective barriers against toxic, radioactive and biologically hazardous materials has been developed. Conductivity, resistivity or capacitance between conductive layers in the multilayer protective materials is measured by using leads connected to electrically conductive layers in the protective barrier material. The measured conductivity, resistivity or capacitance significantly changes upon a physical breach of the protective barrier material.

Built-up outer wall and roofing sections for double walled envelope homes

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

Brodhead, B.

1980-01-01

A site built system that uses the inner envelope wall is described. Blocking and vertical nailers are attached to this wall and sheathed with foil faced drywall to create the envelope cavity. An outer layer of 3 1/2 in. of Expended Poly Styrene provides continuous solid insulation. The trusses are also sheathed in foil faced drywall and insulated with 5 1/2 in. of E.P.S. This effectively surrounds the building with a continuous vapor and infiltration barrier. Construction details as well as cost breakdowns are presented.

Resurrecting Inactive Antimicrobial Peptides from the Lipopolysaccharide Trap

PubMed Central

Mohanram, Harini

2014-01-01

Host defense antimicrobial peptides (AMPs) are a promising source of antibiotics for the treatment of multiple-drug-resistant pathogens. Lipopolysaccharide (LPS), the major component of the outer leaflet of the outer membrane of Gram-negative bacteria, functions as a permeability barrier against a variety of molecules, including AMPs. Further, LPS or endotoxin is the causative agent of sepsis killing 100,000 people per year in the United States alone. LPS can restrict the activity of AMPs inducing aggregations at the outer membrane, as observed for frog AMPs, temporins, and also in model AMPs. Aggregated AMPs, “trapped” by the outer membrane, are unable to traverse the cell wall, causing their inactivation. In this work, we show that these inactive AMPs can overcome LPS-induced aggregations while conjugated with a short LPS binding β-boomerang peptide motif and become highly bactericidal. The generated hybrid peptides exhibit activity against Gram-negative and Gram-positive bacteria in high-salt conditions and detoxify endotoxin. Structural and biophysical studies establish the mechanism of action of these peptides in LPS outer membrane. Most importantly, this study provides a new concept for the development of a potent broad-spectrum antibiotic with efficient outer membrane disruption as the mode of action. PMID:24419338

Durable metallized polymer mirror

DOEpatents

Schissel, Paul O.; Kennedy, Cheryl E.; Jorgensen, Gary J.; Shinton, Yvonne D.; Goggin, Rita M.

1994-01-01

A metallized polymer mirror construction having improved durability against delamination and tunneling, comprising: an outer layer of polymeric material; a metal oxide layer underlying the outer layer of polymeric material; a silver reflective layer underneath the metal oxide layer; and a layer of adhesive attaching the silver layer to a substrate.

Human Mission to Europa and Titan - Why Not? Executive Summary

NASA Technical Reports Server (NTRS)

Finarelli, Margaret G.

2005-01-01

Outline a step-by-step Development Plan of the key barriers and their solutions to enable human exploration of the outer solar system. Secondary: Perform a case study which supports and emphasizes the key elements of the Development Plan.

Cured composite materials for reactive metal battery electrolytes

DOEpatents

Harrup, Mason K.; Stewart, Frederick F.; Peterson, Eric S.

2006-03-07

A solid molecular composite polymer-based electrolyte is made for batteries, wherein silicate compositing produces a electrolytic polymer with a semi-rigid silicate condensate framework, and then mechanical-stabilization by radiation of the outer surface of the composited material is done to form a durable and non-tacky texture on the electrolyte. The preferred ultraviolet radiation produces this desirable outer surface by creating a thin, shallow skin of crosslinked polymer on the composite material. Preferably, a short-duration of low-medium range ultraviolet radiation is used to crosslink the polymers only a short distance into the polymer, so that the properties of the bulk of the polymer and the bulk of the molecular composite material remain unchanged, but the tough and stable skin formed on the outer surface lends durability and processability to the entire composite material product.

Coated woven materials and method of preparation

DOEpatents

McCreary, William J.; Carroll, David W.

1981-01-01

Coating of woven materials so that not only the outer surfaces are coated has been a problem. Now, a solution to that problem is the following: Woven materials are coated with materials, for example with metals or with pyrolytic carbon, which materials are deposited in Chemical Vapor Deposition (CVD) reactions using a fluidized bed so that the porosity of the woven material is retained and so that the tiny filaments which make up the strands which are woven (including inner as well as outer filaments) are substantially uniformly coated.

Protecting peroxidase activity of multilayer enzyme-polyion films using outer catalase layers.

PubMed

Lu, Haiyun; Rusling, James F; Hu, Naifei

2007-12-27

Films constructed layer-by-layer on electrodes with architecture {protein/hyaluronic acid (HA)}n containing myoglobin (Mb) or horseradish peroxidase (HRP) were protected against protein damage by H2O2 by using outer catalase layers. Peroxidase activity for substrate oxidation requires activation by H2O2, but {protein/HA}n films without outer catalase layers are damaged slowly and irreversibly by H2O2. The rate and extent of damage were decreased dramatically by adding outer catalase layers to decompose H2O2. Comparative studies suggest that protection results from catalase decomposing a fraction of the H2O2 as it enters the film, rather than by an in-film diffusion barrier. The outer catalase layers controlled the rate of H2O2 entry into inner regions of the film, and they biased the system to favor electrocatalytic peroxide reduction over enzyme damage. Catalase-protected {protein/HA}n films had an increased linear concentration range for H2O2 detection. This approach offers an effective way to protect biosensors from damage by H2O2.

Durable metallized polymer mirror

DOEpatents

Schissel, P.O.; Kennedy, C.E.; Jorgensen, G.J.; Shinton, Y.D.; Goggin, R.M.

1994-11-01

A metallized polymer mirror construction is disclosed having improved durability against delamination and tunneling, comprising: an outer layer of polymeric material; a metal oxide layer underlying the outer layer of polymeric material; a silver reflective layer underneath the metal oxide layer; and a layer of adhesive attaching the silver layer to a substrate. 6 figs.

49 CFR 173.154 - Exceptions for Class 8 (corrosive materials).

Code of Federal Regulations, 2012 CFR

2012-10-01

... solids, packed in a strong outer packaging. (2) For corrosive materials in Packing Group III, inner... capacity each for solids, packed in a strong outer packaging. (c) Consumer commodities. Until December 31... other requirements of this subchapter when transported by motor vehicle or rail car in a packaging...

Power inverters

DOEpatents

Miller, David H [Redondo Beach, CA; Korich, Mark D [Chino Hills, CA; Smith, Gregory S [Woodland Hills, CA

2011-11-15

Power inverters include a frame and a power module. The frame has a sidewall including an opening and defining a fluid passageway. The power module is coupled to the frame over the opening and includes a substrate, die, and an encasement. The substrate includes a first side, a second side, a center, an outer periphery, and an outer edge, and the first side of the substrate comprises a first outer layer including a metal material. The die are positioned in the substrate center and are coupled to the substrate first side. The encasement is molded over the outer periphery on the substrate first side, the substrate second side, and the substrate outer edge and around the die. The encasement, coupled to the substrate, forms a seal with the metal material. The second side of the substrate is positioned to directly contact a fluid flowing through the fluid passageway.

Method for measurement of radon diffusion and solubility in solid materials

NASA Astrophysics Data System (ADS)

Maier, Andreas; Weber, Uli; Dickmann, Jannis; Breckow, Joachim; van Beek, Patrick; Schardt, Dieter; Kraft, Gerhard; Fournier, Claudia

2018-02-01

In order to study the permeation i.e. the diffusion and solubility of radon gas in biological material, a new setup was constructed and a novel analysis was applied to obtain diffusion and solubility coefficients. Thin slabs of solid materials were installed between detector housing and the surrounding radon exposure chamber of 50 Ls volume. In this setup radon can diffuse through thin test samples into a cylindrical volume of 5 mm height and 20 mm diameter and reach an α-particle detector. There the 5.49 MeV α-decay of the penetrating radon atoms is measured by a silicon surface barrier detector. The time dependent activities inside the small detector volume are recorded after injection of a known radon activity concentration into the outer chamber. Analyzing the time behavior of the integral α-activity from radon in the small vessel, both, the diffusion coefficient and solubility of the test material can be determined, based on a new mathematical model of the diffusion process concerning the special boundary conditions given by the experimental setup. These first measurements were intended as proof of concept for the detection system and the data analysis. Thin polyethylene foils (LDPE) were selected as material for the diffusion measurements and the results were in agreement with data from literature. In further measurements, we will concentrate on biological material like bone, fat and other tissues.

Formation of the outer layer of the Dictyostelium spore coat depends on the inner-layer protein SP85/PsB.

PubMed

Metcalf, Talibah; Kelley, Karen; Erdos, Gregory W; Kaplan, Lee; West, Christopher M

2003-02-01

The Dictyostelium spore is surrounded by a 220 microm thick trilaminar coat that consists of inner and outer electron-dense layers surrounding a central region of cellulose microfibrils. In previous studies, a mutant strain (TL56) lacking three proteins associated with the outer layer exhibited increased permeability to macromolecular tracers, suggesting that this layer contributes to the coat permeability barrier. Electron microscopy now shows that the outer layer is incomplete in the coats of this mutant and consists of a residual regular array of punctate electron densities. The outer layer is also incomplete in a mutant lacking a cellulose-binding protein associated with the inner layer, and these coats are deficient in an outer-layer protein and another coat protein. To examine the mechanism by which this inner-layer protein, SP85, contributes to outer-layer formation, various domain fragments were overexpressed in forming spores. Most of these exert dominant negative effects similar to the deletion of outer-layer proteins, but one construct, consisting of a fusion of the N-terminal and Cys-rich C1 domain, induces a dense mat of novel filaments at the surface of the outer layer. Biochemical studies show that the C1 domain binds cellulose, and a combination of site-directed mutations that inhibits its cellulose-binding activity suppresses outer-layer filament induction. The results suggest that, in addition to a previously described early role in regulating cellulose synthesis, SP85 subsequently contributes a cross-bridging function between cellulose and other coat proteins to organize previously unrecognized structural elements in the outer layer of the coat.

Process for the manufacture of seamless metal-clad fiber-reinforced organic matrix composite structures

NASA Technical Reports Server (NTRS)

Bluck, Raymond M. (Inventor); Bush, Harold G. (Inventor); Johnson, Robert R. (Inventor)

1991-01-01

A process for producing seamless metal-clad composite structures includes providing a hollow, metallic inner member and an outer sleeve to surround the inner member and define an inner space therebetween. A plurality of continuous reinforcing fibers is attached to the distal end of the outside diameter of the inner member, and the inner member is then introduced, distal end first, into one end of the outer sleeve. The inner member is then moved, distal end first, into the outer sleeve until the inner member is completely enveloped by the outer sleeve. A liquid matrix material is then injected into the space containing the reinforcing fibers between the inner member and the outer sleeve. Next a pressurized heat transfer medium is passed through the inner member to cure the liquid matrix material. Finally, the wall thickness of both the inner member and the outer sleeve are reduced to desired dimensions by chemical etching, which adjusts the thermal expansion coefficient of the metal-clad composite structure to a desired value.

Reducing the effect of parasitic capacitance on implantable passive resonant sensors.

PubMed

Drazan, John F; Abdoun, Omar T; Wassick, Michael T; Marcus, George A; Dahle, Reena; Beardslee, Luke A; Cady, Nathaniel C; Ledet, Eric H

2016-08-01

Passive, LC resonators have the potential to serve as small, robust, low cost, implantable sensors to wirelessly monitor implants following orthopedic surgery. One significant barrier to using LC sensors is the influence on the sensor's resonance of the surrounding conductive high permittivity media in vivo. The surrounding media can detune the resonant frequency of the LC sensor resulting in a bias. To mitigate the effects of the surrounding media, we added a "capping layer" to LC sensors to isolate them from the surrounding media. Several capping materials and thicknesses were tested to determine effectiveness at reducing the sensor's interaction with the surrounding media. Results show that a 1 mm glass capping layer on the outer surfaces of the sensor was sufficient to reduce the effects of the media on sensor signal to less than 1%.

Hybrid Composite Cryogenic Tank Structure

NASA Technical Reports Server (NTRS)

DeLay, Thomas

2011-01-01

A hybrid lightweight composite tank has been created using specially designed materials and manufacturing processes. The tank is produced by using a hybrid structure consisting of at least two reinforced composite material systems. The inner composite layer comprises a distinct fiber and resin matrix suitable for cryogenic use that is a braided-sleeve (and/or a filamentwound layer) aramid fiber preform that is placed on a removable mandrel (outfitted with metallic end fittings) and is infused (vacuum-assisted resin transfer molded) with a polyurethane resin matrix with a high ductility at low temperatures. This inner layer is allowed to cure and is encapsulated with a filamentwound outer composite layer of a distinct fiber resin system. Both inner and outer layer are in intimate contact, and can also be cured at the same time. The outer layer is a material that performs well for low temperature pressure vessels, and it can rely on the inner layer to act as a liner to contain the fluids. The outer layer can be a variety of materials, but the best embodiment may be the use of a continuous tow of carbon fiber (T-1000 carbon, or others), or other high-strength fibers combined with a high ductility epoxy resin matrix, or a polyurethane matrix, which performs well at low temperatures. After curing, the mandrel can be removed from the outer layer. While the hybrid structure is not limited to two particular materials, a preferred version of the tank has been demonstrated on an actual test tank article cycled at high pressures with liquid nitrogen and liquid hydrogen, and the best version is an inner layer of PBO (poly-pphenylenebenzobisoxazole) fibers with a polyurethane matrix and an outer layer of T-1000 carbon with a high elongation epoxy matrix suitable for cryogenic temperatures. A polyurethane matrix has also been used for the outer layer. The construction method is ideal because the fiber and resin of the inner layer has a high strain to failure at cryogenic temperatures, and will not crack or produce leaks. The outer layer serves as more of a high-performance structural unit for the inner layer, and can handle external environments.

Description of an α-cluster tail in 8Be and 20Ne: Delocalization of the α cluster by quantum penetration

NASA Astrophysics Data System (ADS)

Kanada-En'yo, Yoshiko

2014-10-01

We analyze the α-cluster wave functions in cluster states of ^8Be and ^{20}Ne by comparing the exact relative wave function obtained by the generator coordinate method (GCM) with various types of trial functions. For the trial functions, we adopt the fixed range shifted Gaussian of the Brink-Bloch (BB) wave function, the spherical Gaussian with the adjustable range parameter of the spherical Tohsaki-Horiuchi-Schuck-Röpke (sTHSR), the deformed Gaussian of the deformed THSR (dTHSR), and a function with the Yukawa tail (YT). The quality of the description of the exact wave function with a trial function is judged by the squared overlap between the trial function and the GCM wave function. A better result is obtained with the sTHSR wave function than the BB wave function, and further improvement can be made with the dTHSR wave function because these wave functions can describe the outer tail better. The YT wave function gives almost an equal quality to or even better quality than the dTHSR wave function, indicating that the outer tail of α-cluster states is characterized by the Yukawa-like tail rather than the Gaussian tail. In weakly bound α-cluster states with small α separation energy and the low centrifugal and Coulomb barriers, the outer tail part is the slowly damping function described well by the quantum penetration through the effective barrier. This outer tail characterizes the almost zero-energy free α gas behavior, i.e., the delocalization of the cluster.

Abrasion Testing of Candidate Outer Layer Fabrics for Lunar EVA Space Suits

NASA Technical Reports Server (NTRS)

Mitchell, Kathryn

2009-01-01

During the Apollo program, the space suit outer layer fabrics were severely abraded after just a few Extravehicular Activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots, which penetrated the outer layer fabric into the thermal protection layers after less than eight hours of surface operations. Current plans for the Constellation Space Suit Element require the space suits to support hundreds of hours of EVA on the Lunar surface, creating a challenge for space suit designers to utilize materials advances made over the last forty years and improve upon the space suit fabrics used in the Apollo program. A test methodology has been developed by the NASA Johnson Space Center Crew and Thermal Systems Division for establishing comparative abrasion wear characteristics between various candidate space suit outer layer fabrics. The abrasion test method incorporates a large rotary drum tumbler with rocks and loose lunar simulant material to induce abrasion in fabric test cylinder elements, representative of what might occur during long term planetary surface EVAs. Preliminary materials screening activities were conducted to determine the degree of wear on representative space suit outer layer materials and the corresponding dust permeation encountered between subsequent sub-layers of thermal protective materials when exposed to a simulated worst case eight hour EVA. The test method was used to provide a preliminary evaluation of four candidate outer layer fabrics for future planetary surface space suit applications. This paper provides a review of previous abrasion studies on space suit fabrics, details the methodologies used for abrasion testing in this particular study, shares the results of the testing, and provides recommendations for future work.

Abrasion Testing of Candidate Outer Layer Fabrics for Lunar EVA Space Suits

NASA Technical Reports Server (NTRS)

Mitchell, Kathryn C.

2010-01-01

During the Apollo program, the space suit outer layer fabrics were badly abraded after just a few Extravehicular Activities (EVAs). For example, the Apollo 12 commander reported abrasive wear on the boots, which penetrated the outer layer fabric into the thermal protection layers after less than eight hours of surface operations. Current plans for the Constellation Space Suit Element require the space suits to support hundreds of hours of EVA on the Lunar surface, creating a challenge for space suit designers to utilize materials advances made over the last forty years and improve upon the space suit fabrics used in the Apollo program. A test methodology has been developed by the NASA Johnson Space Center Crew and Thermal Systems Division for establishing comparative abrasion wear characteristics between various candidate space suit outer layer fabrics. The abrasion test method incorporates a large rotary drum tumbler with rocks and loose lunar simulant material to induce abrasion in fabric test cylinder elements, representative of what might occur during long term planetary surface EVAs. Preliminary materials screening activities were conducted to determine the degree of wear on representative space suit outer layer materials and the corresponding dust permeation encountered between subsequent sub -layers of thermal protective materials when exposed to a simulated worst case eight hour EVA. The test method was used to provide a preliminary evaluation of four candidate outer layer fabrics for future planetary surface space suit applications. This Paper provides a review of previous abrasion studies on space suit fabrics, details the methodologies used for abrasion testing in this particular study, and shares the results and conclusions of the testing.

No barrier to emergence of bathyal king crabs on the Antarctic shelf.

PubMed

Aronson, Richard B; Smith, Kathryn E; Vos, Stephanie C; McClintock, James B; Amsler, Margaret O; Moksnes, Per-Olav; Ellis, Daniel S; Kaeli, Jeffrey; Singh, Hanumant; Bailey, John W; Schiferl, Jessica C; van Woesik, Robert; Martin, Michael A; Steffel, Brittan V; Deal, Michelle E; Lazarus, Steven M; Havenhand, Jonathan N; Swalethorp, Rasmus; Kjellerup, Sanne; Thatje, Sven

2015-10-20

Cold-water conditions have excluded durophagous (skeleton-breaking) predators from the Antarctic seafloor for millions of years. Rapidly warming seas off the western Antarctic Peninsula could now facilitate their return to the continental shelf, with profound consequences for the endemic fauna. Among the likely first arrivals are king crabs (Lithodidae), which were discovered recently on the adjacent continental slope. During the austral summer of 2010 ‒ 2011, we used underwater imagery to survey a slope-dwelling population of the lithodid Paralomis birsteini off Marguerite Bay, western Antarctic Peninsula for environmental or trophic impediments to shoreward expansion. The population density averaged ∼ 4.5 individuals × 1,000 m(-2) within a depth range of 1,100 ‒ 1,500 m (overall observed depth range 841-2,266 m). Images of juveniles, discarded molts, and precopulatory behavior, as well as gravid females in a trapping study, suggested a reproductively viable population on the slope. At the time of the survey, there was no thermal barrier to prevent the lithodids from expanding upward and emerging on the outer shelf (400- to 550-m depth); however, near-surface temperatures remained too cold for them to survive in inner-shelf and coastal environments (<200 m). Ambient salinity, composition of the substrate, and the depth distribution of potential predators likewise indicated no barriers to expansion of lithodids onto the outer shelf. Primary food resources for lithodids--echinoderms and mollusks--were abundant on the upper slope (550-800 m) and outer shelf. As sea temperatures continue to rise, lithodids will likely play an increasingly important role in the trophic structure of subtidal communities closer to shore.

No barrier to emergence of bathyal king crabs on the Antarctic shelf

PubMed Central

Aronson, Richard B.; Smith, Kathryn E.; Vos, Stephanie C.; McClintock, James B.; Amsler, Margaret O.; Moksnes, Per-Olav; Ellis, Daniel S.; Kaeli, Jeffrey; Singh, Hanumant; Bailey, John W.; Schiferl, Jessica C.; van Woesik, Robert; Martin, Michael A.; Steffel, Brittan V.; Deal, Michelle E.; Lazarus, Steven M.; Havenhand, Jonathan N.; Swalethorp, Rasmus; Kjellerup, Sanne; Thatje, Sven

2015-01-01

Cold-water conditions have excluded durophagous (skeleton-breaking) predators from the Antarctic seafloor for millions of years. Rapidly warming seas off the western Antarctic Peninsula could now facilitate their return to the continental shelf, with profound consequences for the endemic fauna. Among the likely first arrivals are king crabs (Lithodidae), which were discovered recently on the adjacent continental slope. During the austral summer of 2010‒2011, we used underwater imagery to survey a slope-dwelling population of the lithodid Paralomis birsteini off Marguerite Bay, western Antarctic Peninsula for environmental or trophic impediments to shoreward expansion. The population density averaged ∼4.5 individuals × 1,000 m−2 within a depth range of 1,100‒1,500 m (overall observed depth range 841–2,266 m). Images of juveniles, discarded molts, and precopulatory behavior, as well as gravid females in a trapping study, suggested a reproductively viable population on the slope. At the time of the survey, there was no thermal barrier to prevent the lithodids from expanding upward and emerging on the outer shelf (400- to 550-m depth); however, near-surface temperatures remained too cold for them to survive in inner-shelf and coastal environments (<200 m). Ambient salinity, composition of the substrate, and the depth distribution of potential predators likewise indicated no barriers to expansion of lithodids onto the outer shelf. Primary food resources for lithodids—echinoderms and mollusks—were abundant on the upper slope (550–800 m) and outer shelf. As sea temperatures continue to rise, lithodids will likely play an increasingly important role in the trophic structure of subtidal communities closer to shore. PMID:26417090

Mfsd2a Is a Transporter for the Essential ω-3 Fatty Acid Docosahexaenoic Acid (DHA) in Eye and Is Important for Photoreceptor Cell Development*

PubMed Central

Wong, Bernice H.; Chan, Jia Pei; Cazenave-Gassiot, Amaury; Poh, Rebecca W.; Foo, Juat Chin; Galam, Dwight L. A.; Ghosh, Sujoy; Nguyen, Long N.; Barathi, Veluchamy A.; Yeo, Sia W.; Luu, Chi D.; Wenk, Markus R.; Silver, David L.

2016-01-01

Eye photoreceptor membrane discs in outer rod segments are highly enriched in the visual pigment rhodopsin and the ω-3 fatty acid docosahexaenoic acid (DHA). The eye acquires DHA from blood, but transporters for DHA uptake across the blood-retinal barrier or retinal pigment epithelium have not been identified. Mfsd2a is a newly described sodium-dependent lysophosphatidylcholine (LPC) symporter expressed at the blood-brain barrier that transports LPCs containing DHA and other long-chain fatty acids. LPC transport via Mfsd2a has been shown to be necessary for human brain growth. Here we demonstrate that Mfsd2a is highly expressed in retinal pigment epithelium in embryonic eye, before the development of photoreceptors, and is the primary site of Mfsd2a expression in the eye. Eyes from whole body Mfsd2a-deficient (KO) mice, but not endothelium-specific Mfsd2a-deficient mice, were DHA-deficient and had significantly reduced LPC/DHA transport in vivo. Fluorescein angiography indicated normal blood-retinal barrier function. Histological and electron microscopic analysis indicated that Mfsd2a KO mice exhibited a specific reduction in outer rod segment length, disorganized outer rod segment discs, and mislocalization of and reduction in rhodopsin early in postnatal development without loss of photoreceptors. Minor photoreceptor cell loss occurred in adult Mfsd2a KO mice, but electroretinography indicated visual function was normal. The developing eyes of Mfsd2a KO mice had activated microglia and up-regulation of lipogenic and cholesterogenic genes, likely adaptations to loss of LPC transport. These findings identify LPC transport via Mfsd2a as an important pathway for DHA uptake in eye and for development of photoreceptor membrane discs. PMID:27008858

49 CFR 173.154 - Exceptions for Class 8 (corrosive materials).

Code of Federal Regulations, 2013 CFR

2013-10-01

... solids, packed in a strong outer packaging. (2) For corrosive materials in Packing Group III, inner... capacity each for solids, packed in a strong outer packaging. (c) Consumer commodities. Until December 31... subject to any other requirements of this subchapter when transported by motor vehicle or rail car in a...

Method and system including a double rotary kiln pyrolysis or gasification of waste material

DOEpatents

McIntosh, M.J.; Arzoumanidis, G.G.

1997-09-02

A method is described for destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500 C to heat the particulate material to a temperature in the range of from about 200 C to about 900 C in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet. 5 figs.

Method and system including a double rotary kiln pyrolysis or gasification of waste material

DOEpatents

McIntosh, Michael J.; Arzoumanidis, Gregory G.

1997-01-01

A method of destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500.degree. C. to heat the particulate material to a temperature in the range of from about 200.degree. C. to about 900.degree. C. in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet.

Breaking barriers: expansion of the use of endolysins as novel antibacterials against Gram-negative bacteria.

PubMed

Briers, Yves; Lavigne, Rob

2015-01-01

The emergence and spread of antibiotic-resistant bacteria drives the search for novel classes of antibiotics to replenish our armamentarium against bacterial infections. This is particularly critical for Gram-negative pathogens, which are intrinsically resistant to many existing classes of antibiotics due to the presence of a protective outer membrane. In addition, the antibiotics development pipeline is mainly oriented to Gram-positive pathogens such as methicillin-resistant Staphylococcus aureus. A promising novel class of antibacterials is endolysins. These enzymes encoded by bacterial viruses hydrolyze the peptidoglycan layer with high efficiency, resulting in abrupt osmotic lysis and cell death. Their potential as novel antibacterials to treat Gram-positive bacteria has been extensively demonstrated; however, the Gram-negative outer membrane has presented a formidable barrier for the use of endolysins against Gram-negatives until recently. This review reports on the most recent advances in the development of endolysins to kill Gram-negative species with a special focus on endolysin-engineered Artilysins(®).

Dissecting Escherichia coli Outer Membrane Biogenesis Using Differential Proteomics

PubMed Central

Martorana, Alessandra M.; Motta, Sara; Di Silvestre, Dario; Falchi, Federica; Dehò, Gianni; Mauri, Pierluigi; Sperandeo, Paola; Polissi, Alessandra

2014-01-01

The cell envelope of Gram-negative bacteria is a complex multi-layered structure comprising an inner cytoplasmic membrane and an additional asymmetric lipid bilayer, the outer membrane, which functions as a selective permeability barrier and is essential for viability. Lipopolysaccharide, an essential glycolipid located in the outer leaflet of the outer membrane, greatly contributes to the peculiar properties exhibited by the outer membrane. This complex molecule is transported to the cell surface by a molecular machine composed of seven essential proteins LptABCDEFG that form a transenvelope complex and function as a single device. While advances in understanding the mechanisms that govern the biogenesis of the cell envelope have been recently made, only few studies are available on how bacterial cells respond to severe envelope biogenesis defects on a global scale. Here we report the use of differential proteomics based on Multidimensional Protein Identification Technology (MudPIT) to investigate how Escherichia coli cells respond to a block of lipopolysaccharide transport to the outer membrane. We analysed the envelope proteome of a lptC conditional mutant grown under permissive and non permissive conditions and identified 123 proteins whose level is modulated upon LptC depletion. Most such proteins belong to pathways implicated in cell envelope biogenesis, peptidoglycan remodelling, cell division and protein folding. Overall these data contribute to our understanding on how E. coli cells respond to LPS transport defects to restore outer membrane functionality. PMID:24967819

Importance of Real-Time Assays To Distinguish Multidrug Efflux Pump-Inhibiting and Outer Membrane-Destabilizing Activities in Escherichia coli.

PubMed

Misra, Rajeev; Morrison, Keith D; Cho, Hyun Jae; Khuu, Thanh

2015-08-01

The constitutively expressed AcrAB multidrug efflux system of Escherichia coli shows a high degree of homology with the normally silent AcrEF system. Exposure of a strain with acrAB deleted to antibiotic selection pressure frequently leads to the insertion sequence-mediated activation of the homologous AcrEF system. In this study, we used strains constitutively expressing either AcrAB or AcrEF from their normal chromosomal locations to resolve a controversy about whether phenylalanylarginine β-naphthylamide (PAβN) inhibits the activities of AcrAB and AcrEF and/or acts synergistically with antibiotics by destabilizing the outer membrane permeability barrier. Real-time efflux assays allowed a clear distinction between the efflux pump-inhibiting activity of PAβN and the outer membrane-destabilizing action of polymyxin B nonapeptide (PMXBN). When added in equal amounts, PAβN, but not PMXBN, strongly inhibited the efflux activities of both AcrAB and AcrEF pumps. In contrast, when outer membrane destabilization was assessed by the nitrocefin hydrolysis assay, PMXBN exerted a much greater damaging effect than PAβN. Strong action of PAβN in inhibiting efflux activity compared to its weak action in destabilizing the outer membrane permeability barrier suggests that PAβN acts mainly by inhibiting efflux pumps. We concluded that at low concentrations, PAβN acts specifically as an inhibitor of both AcrAB and AcrEF efflux pumps; however, at high concentrations, PAβN in the efflux-proficient background not only inhibits efflux pump activity but also destabilizes the membrane. The effects of PAβN on membrane integrity are compounded in cells unable to extrude PAβN. The increase in multidrug-resistant bacterial pathogens at an alarming rate has accelerated the need for implementation of better antimicrobial stewardship, discovery of new antibiotics, and deeper understanding of the mechanism of drug resistance. The work carried out in this study highlights the importance of employing real-time fluorescence-based assays in differentiating multidrug efflux-inhibitory and outer membrane-destabilizing activities of antibacterial compounds. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Effects of materials and design on the criticality and shielding assessment of canister concepts for the disposal of spent nuclear fuel.

PubMed

Gutiérrez, Miguel Morales; Caruso, Stefano; Diomidis, Nikitas

2018-05-19

According to the Swiss disposal concept, the safety of a deep geological repository for spent nuclear fuel (SNF) is based on a multi-barrier system. The disposal canister is an important component of the engineered barrier system, aiming to provide containment of the SNF for thousands of years. This study evaluates the criticality safety and shielding of candidate disposal canister concepts, focusing on the fulfilment of the sub-criticality criterion and on limiting radiolysis processes at the outer surface of the canister which can enhance corrosion mechanisms. The effective neutron multiplication factor (k-eff) and the surface dose rates are calculated for three different canister designs and material combinations for boiling water reactor (BWR) canisters, containing 12 spent fuel assemblies (SFA), and pressurized water reactor (PWR) canisters, with 4 SFAs. For each configuration, individual criticality and shielding calculations were carried out. The results show that k-eff falls below the defined upper safety limit (USL) of 0.95 for all BWR configurations, while staying above USL for the PWR ones. Therefore, the application of a burnup credit methodology for the PWR case is required, being currently under development. Relevant is also the influence of canister material and internal geometry on criticality, enabling the identification of safer fuel arrangements. For a final burnup of 55MWd/kgHM and 30y cooling time, the combined photon-neutron surface dose rate is well below the threshold of 1 Gy/h defined to limit radiation-induced corrosion of the canister in all cases. Copyright © 2018 Elsevier Ltd. All rights reserved.

Law and politics in outer space: A bibliography.

NASA Technical Reports Server (NTRS)

White, I. L.; Wilson, C. E.; Vosburgh, J. A.

1972-01-01

The materials are categorized by specific topics and by types of materials. The sources are books, articles, reports, United Nations materials, U.S. Government documents, etc. Books are listed by geographical areas, and articles are divided into what are considered to be the major space topics. Book and article sections are also divided into English and foreign language entries. A bibliographical essay introduces the literature to those unacquainted with law and politics of outer space.

Outer-membrane translocation of bulky small molecules by passive diffusion

PubMed Central

van den Berg, Bert; Prathyusha Bhamidimarri, Satya; Dahyabhai Prajapati, Jigneshkumar; Kleinekathöfer, Ulrich; Winterhalter, Mathias

2015-01-01

The outer membrane (OM) of gram-negative bacteria forms a protective layer around the cell that serves as a permeability barrier to prevent unrestricted access of noxious substances. The permeability barrier of the OM results partly from the limited pore diameters of OM diffusion channels. As a consequence, there is an “OM size-exclusion limit,” and the uptake of bulky molecules with molecular masses of more than ∼600 Da is thought to be mediated by TonB-dependent, active transporters. Intriguingly, the OM protein CymA from Klebsiella oxytoca does not depend on TonB but nevertheless mediates efficient OM passage of cyclodextrins with diameters of up to ∼15 Å. Here we show, by using X-ray crystallography, molecular dynamics simulations, and single-channel electrophysiology, that CymA forms a monomeric 14-stranded β-barrel with a large pore that is occluded on the periplasmic side by the N-terminal 15 residues of the protein. Representing a previously unidentified paradigm in OM transport, CymA mediates the passive diffusion of bulky molecules via an elegant transport mechanism in which a mobile element formed by the N terminus acts as a ligand-expelled gate to preserve the permeability barrier of the OM. PMID:26015567

Extended-Release Naltrexone: A Qualitative Analysis of Barriers to Routine Use.

PubMed

Alanis-Hirsch, Kelly; Croff, Raina; Ford, James H; Johnson, Kim; Chalk, Mady; Schmidt, Laura; McCarty, Dennis

2016-03-01

The Medication Research Partnership (a national health plan and nine addiction treatment centers contracted with the health plan) sought to facilitate the adoption of pharmacotherapy for alcohol and opioid use disorders. Qualitative analysis of interviews with treatment center change leaders, individuals working for the manufacturer and its technical assistance contractor, and health plan managers extracted details on the processes used to order, store, bill for, and administer extended-release naltrexone. Qualitative themes were categorized using domains from the Consolidated Framework for Implementation Research (intervention characteristics, outer setting, inner setting, and provider characteristics). Characteristics of XR-NTX that inhibited use included the complexity of ordering and using the medication; cost was also a barrier. Outer setting barriers reflected patient needs and external health plan policies on formulary coverage, benefit management, and reimbursement. Program structures, the lack of physician linkages, a culture resistant to the use of medication, and unease with change were inner setting elements that limited use of XR-NTX. Patient stereotypes and a lack of knowledge about XR-NTX affected practitioner willingness to treat patients and prescribe XR-NTX. The Consolidated Framework for Implementation Research provided a useful lens to understand and interpret the processes affecting access to XR-NTX. Copyright © 2015 Elsevier Inc. All rights reserved.

Degradation of a two-layer thermal barrier coating under thermal cycling. [for superalloys of aircraft turbine engine blades

NASA Technical Reports Server (NTRS)

Maier, R. D.; Scheuermann, C. M.; Andrews, C. W.

1981-01-01

A two-layer plasma-sprayed thermal barrier coating on a directionally solidified nickel-base eutectic alloy substrate was characterized prior to and after thermal cycling to 1095 C in an accelerated furnace test. The coating was comprised of an inner layer of Ni-16.4Cr-5.1Al-0.15Y (wt%) bond coat and an outer layer of ZrO2-7.9Y2O3 (wt%) thermal barrier. Characterization of the bond coat revealed that substantial amounts of yttrium and aluminum were oxidized during plasma-spraying in air. The oxidation of these elements reduced the protective capacity of the bond coat so that, on thermal exposure, severe degradation of the bond coat resulted and large amounts of nickel oxide formed. This nickel oxide was demonstrated to grow outward into the thermal barrier, which appears to have increased the stresses in the thermal barrier and contributed to its failure near the thermal barrier-bond coat interface.

Outer Space...Calling All Readers. 1991 Summer Reading Program Manual.

ERIC Educational Resources Information Center

North Carolina State Dept. of Cultural Resources, Raleigh. Div. of State Library.

This manual provides guidelines and materials for librarians planning a summer reading program for children in North Carolina on the theme of outer space. An evaluation form to be returned to the State Library of North Carolina at the end of the summer is included. The introduction includes discussions of summer reading materials and programs;…

Radioactive waste disposal package

DOEpatents

Lampe, Robert F.

1986-11-04

A radioactive waste disposal package comprising a canister for containing vitrified radioactive waste material and a sealed outer shell encapsulating the canister. A solid block of filler material is supported in said shell and convertible into a liquid state for flow into the space between the canister and outer shell and subsequently hardened to form a solid, impervious layer occupying such space.

Radioactive waste disposal package

DOEpatents

Lampe, Robert F.

1986-01-01

A radioactive waste disposal package comprising a canister for containing vitrified radioactive waste material and a sealed outer shell encapsulating the canister. A solid block of filler material is supported in said shell and convertible into a liquid state for flow into the space between the canister and outer shell and subsequently hardened to form a solid, impervious layer occupying such space.

High-temperature, flexible, thermal barrier seal

NASA Technical Reports Server (NTRS)

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

1991-01-01

This device seals the sliding interfaces between structural panels that are roughly perpendicular to each other or whose edges are butted against one another. The nonuniformity of the gap between the panels requires significant flexibility along the seal length. The seal is mounted in a rectangular groove in a movable structural panel. A plurality of particles or balls is densely packed in an outer sheathing. The balls are laterally preloaded to maintain sealing contact with the adjacent wall using a pressurized linear bellows. Distortions in the adjacent panel are accommodated by rearrangement of the particles within the outer sheathing. Leakage through the seal is minimized by densely compacting the internal particles and by maintaining positive preload along the back side of the seal. The braid architecture of the outer sheathing is selected to minimize leakage through the seal and to resist mechanical abrasion.

In-situ vitrification of waste materials

DOEpatents

Powell, J.R.; Reich, M.; Barletta, R.

1997-10-14

A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed. 7 figs.

In-situ vitrification of waste materials

DOEpatents

Powell, James R.; Reich, Morris; Barletta, Robert

1997-11-14

A method for the in-situ vitrification of waste materials in a disposable can that includes an inner container and an outer container is disclosed. The method includes the steps of adding frit and waste materials to the inner container, removing any excess water, heating the inner container such that the frit and waste materials melt and vitrify after cooling, while maintaining the outer container at a significantly lower temperature than the inner container. The disposable can is then cooled to ambient temperatures and stored. A device for the in-situ vitrification of waste material in a disposable can is also disclosed.

75 FR 45195 - Office of Hazardous Materials Safety; Notice of Applications for Modification of Special Permit

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-02

... compressed oxygen without rigid outer packaging when no other means of transportation exist. 14860-M Alaska... authorizing the transportation in commerce of compressed oxygen without rigid outer packaging when no other... transportation in commerce of compressed oxygen without rigid outer packaging when no other means of...

Tri-membrane nanoparticles produced by combining liposome fusion and a novel patchwork of bicelles to overcome endosomal and nuclear membrane barriers to cargo delivery.

PubMed

Yamada, Asako; Mitsueda, Asako; Hasan, Mahadi; Ueda, Miho; Hama, Susumu; Warashina, Shota; Nakamura, Takashi; Harashima, Hideyoshi; Kogure, Kentaro

2016-03-01

Membrane fusion is a rational strategy for crossing intracellular membranes that present barriers to liposomal nanocarrier-mediated delivery of plasmid DNA into the nucleus of non-dividing cells, such as dendritic cells. Based on this strategy, we previously developed nanocarriers consisting of a nucleic acid core particle coated with four lipid membranes [Akita, et al., Biomaterials, 2009, 30, 2940-2949]. However, including the endosomal membrane and two nuclear membranes, cells possess three intracellular membranous barriers. Thus, after entering the nucleus, nanoparticles coated with four membranes would still have one lipid membrane remaining, and could impede cargo delivery. Until now, coating a core particle with an odd number of lipid membranes was challenging. To produce nanocarriers with an odd number of lipid membranes, we developed a novel coating method involving lipid nano-discs, also known as bicelles, as a material for packaging DNA in a carrier with an odd number of lipid membranes. In this procedure, bicelles fuse to form an outer coating that resembles a patchwork quilt, which allows the preparation of nanoparticles coated with only three lipid membranes. Moreover, the transfection activity of dendritic cells with these three-membrane nanoparticles was higher than that for nanoparticles coated with four lipid membranes. In summary, we developed novel nanoparticles coated with an odd number of lipid membranes using the novel "patchwork-packaging method" to deliver plasmid DNA into the nucleus via membrane fusion.

Seamless metal-clad fiber-reinforced organic matrix composite structures and process for their manufacture

NASA Technical Reports Server (NTRS)

Bluck, Raymond M. (Inventor); Bush, Harold G. (Inventor); Johnson, Robert R. (Inventor)

1990-01-01

A metallic outer sleeve is provided which is capable of enveloping a hollow metallic inner member having continuous reinforcing fibers attached to the distal end thereof. The inner member is then introduced into outer sleeve until inner member is completely enveloped by outer sleeve. A liquid matrix member is then injected into space between inner member and outer sleeve. A pressurized heat transfer medium is flowed through the inside of inner member, thereby forming a fiber reinforced matrix composite material. The wall thicknesses of both inner member and outer sleeve are then reduced to the appropriate size by chemical etching, to adjust the thermal expansion coefficient of the metal-clad composite structure to the desired value. thereby forming a fiber reinforced matrix composite material. The wall thicknesses of both inner member and outer sleeve are then reduced to the appropriate size by chemical etching, to adjust the thermal expansion coefficient of the metal-clad composite structure to the desired value. The novelty of this invention resides in the development of a efficient method of producing seamless metal clad fiber reinforced organic matrix composite structures.

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.

Photoconductive switch package

DOEpatents

Ca[rasp, George J

2013-10-22

A photoconductive switch is formed of a substrate that has a central portion of SiC or other photoconductive material and an outer portion of cvd-diamond or other suitable material surrounding the central portion. Conducting electrodes are formed on opposed sides of the substrate, with the electrodes extending beyond the central portion and the edges of the electrodes lying over the outer portion. Thus any high electric fields produced at the edges of the electrodes lie outside of and do not affect the central portion, which is the active switching element. Light is transmitted through the outer portion to the central portion to actuate the switch.

Accumulation of phosphatidic acid increases vancomycin resistance in Escherichia coli.

PubMed

Sutterlin, Holly A; Zhang, Sisi; Silhavy, Thomas J

2014-09-01

In Gram-negative bacteria, lipopolysaccharide (LPS) contributes to the robust permeability barrier of the outer membrane, preventing entry of toxic molecules such as antibiotics. Mutations in lptD, the beta-barrel component of the LPS transport and assembly machinery, compromise LPS assembly and result in increased antibiotic sensitivity. Here, we report rare vancomycin-resistant suppressors that improve barrier function of a subset of lptD mutations. We find that all seven suppressors analyzed mapped to the essential gene cdsA, which is responsible for the conversion of phosphatidic acid to CDP-diacylglycerol in phospholipid biosynthesis. These cdsA mutations cause a partial loss of function and, as expected, accumulate phosphatidic acid. We show that this suppression is not confined to mutations that cause defects in outer membrane biogenesis but rather that these cdsA mutations confer a general increase in vancomycin resistance, even in a wild-type cell. We use genetics and quadrupole time of flight (Q-TOF) liquid chromatography-mass spectrometry (LC-MS) to show that accumulation of phosphatidic acid by means other than cdsA mutations also increases resistance to vancomycin. We suggest that increased levels of phosphatidic acid change the physical properties of the outer membrane to impede entry of vancomycin into the periplasm, hindering access to its target, an intermediate required for the synthesis of the peptidoglycan cell wall. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Thermal barrier coating experience in the gas turbine engine

NASA Technical Reports Server (NTRS)

Bose, S.; Demasi-Marcin, J.

1995-01-01

Thermal Barrier Coatings (TBC), provide thermal insulation and oxidation resistance in an environment consisting of hot combustion gases. TBC's consist of a two layer system. The outer ceramic layer provides good thermal insulation due to the low thermal conductivity of the ceramic coatings used, while the inner metallic bond coat layer provides needed oxidation resistance to the underlying superalloy. Pratt & Whitney has over a decade of experience with several generations of TBC systems on turbine airfoils. This paper will focus on the latest TBC field experience along with a proposed durability model.

Method for contamination control and barrier apparatus with filter for containing waste materials that include dangerous particulate matter

DOEpatents

Pinson, Paul A.

1998-01-01

A container for hazardous waste materials that includes air or other gas carrying dangerous particulate matter has incorporated in barrier material, preferably in the form of a flexible sheet, one or more filters for the dangerous particulate matter sealably attached to such barrier material. The filter is preferably a HEPA type filter and is preferably chemically bonded to the barrier materials. The filter or filters are preferably flexibly bonded to the barrier material marginally and peripherally of the filter or marginally and peripherally of air or other gas outlet openings in the barrier material, which may be a plastic bag. The filter may be provided with a backing panel of barrier material having an opening or openings for the passage of air or other gas into the filter or filters. Such backing panel is bonded marginally and peripherally thereof to the barrier material or to both it and the filter or filters. A coupling or couplings for deflating and inflating the container may be incorporated. Confining a hazardous waste material in such a container, rapidly deflating the container and disposing of the container, constitutes one aspect of the method of the invention. The chemical bonding procedure for producing the container constitutes another aspect of the method of the invention.

Method for contamination control and barrier apparatus with filter for containing waste materials that include dangerous particulate matter

DOEpatents

Pinson, P.A.

1998-02-24

A container for hazardous waste materials that includes air or other gas carrying dangerous particulate matter has incorporated barrier material, preferably in the form of a flexible sheet, and one or more filters for the dangerous particulate matter sealably attached to such barrier material. The filter is preferably a HEPA type filter and is preferably chemically bonded to the barrier materials. The filter or filters are preferably flexibly bonded to the barrier material marginally and peripherally of the filter or marginally and peripherally of air or other gas outlet openings in the barrier material, which may be a plastic bag. The filter may be provided with a backing panel of barrier material having an opening or openings for the passage of air or other gas into the filter or filters. Such backing panel is bonded marginally and peripherally thereof to the barrier material or to both it and the filter or filters. A coupling or couplings for deflating and inflating the container may be incorporated. Confining a hazardous waste material in such a container, rapidly deflating the container and disposing of the container, constitutes one aspect of the method of the invention. The chemical bonding procedure for producing the container constitutes another aspect of the method of the invention. 3 figs.

Protective coating for ceramic materials

NASA Technical Reports Server (NTRS)

Kourtides, Demetrius A. (Inventor); Churchward, Rex A. (Inventor); Lowe, David M. (Inventor)

1994-01-01

A protective coating for ceramic materials such as those made of silicon carbide, aluminum oxide, zirconium oxide, aluminoborosilicate and silicon dioxide, and a thermal control structure comprising a ceramic material having coated thereon the protective coating. The protective coating contains, in admixture, silicon dioxide powder, colloidal silicon dioxide, water, and one or more emittance agents selected from silicon tetraboride, silicon hexaboride, silicon carbide, molybdenum disilicide, tungsten disilicide and zirconium diboride. In another aspect, the protective coating is coated on a flexible ceramic fabric which is the outer cover of a composite insulation. In yet another aspect, a metallic foil is bonded to the outer surface of a ceramic fabric outer cover of a composite insulation via the protective coating. A primary application of this invention is as a protective coating for ceramic materials used in a heat shield for space vehicles subjected to very high aero-convective heating environments.

Could tight junctions regulate the barrier function of the aged skin?

PubMed

Svoboda, Marek; Bílková, Zuzana; Muthný, Tomáš

2016-03-01

The skin is known to be the largest organ in human organism creating interface with outer environment. The skin provides protective barrier against pathogens, physical and chemical insults, and against uncontrolled loss of water. The barrier function was primarily attributed to the stratum corneum (SC) but recent studies confirmed that epidermal tight junctions (TJs) also play important role in maintaining barrier properties of the skin. Independent observations indicate that barrier function and its recovery is impaired in aged skin. However, trans-epidermal water loss (TEWL) values remains rather unchanged in elderly population. UV radiation as major factor of photoageing impairs TJ proteins, but TJs have great self-regenerative potential. Since it may be possible that TJs can compensate TEWL in elderly due to its regenerative and compensatory capabilities, important question remains to be answered: how are TJs regulated during skin ageing? This review provides an insight into TJs functioning as epidermal barrier and summarizes current knowledge about the impact of ageing on the barrier function of the skin and epidermal TJs. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Geographic Variation in Health Service Use and Perceived Access Barriers for Australian Adults with Chronic Non-Cancer Pain Receiving Opioid Therapy.

PubMed

Peacock, Amy; Nielsen, Suzanne; Bruno, Raimondo; Campbell, Gabrielle; Larance, Briony; Degenhardt, Louisa

2016-11-01

Rates of chronic non-cancer pain are increasing worldwide, with concerns regarding poorer access to specialist treatment services in remote areas. The current study comprised the first in-depth examination of use and barriers to access of health services in Australia according to remoteness. A cohort of Australian adults prescribed pharmaceutical opioids for chronic non-cancer pain (n = 1,235) were interviewed between August 2012 and April 2014, and grouped into 'major city' (49%), 'inner regional' (37%), and 'outer regional/remote' (14%) according to the Australian Standard Geographical Classification based on postcode. Multinomial logistic regression analyses were conducted to determine geographical differences in socio-demographic and clinical characteristics, health service use, and perceived barriers to health service access. The 'inner regional group' and 'outer regional/remote group' were more likely to be male (relative risk ratio (RRR)=1.38,95%CI 1.08-1.77 and RRR = 1.60, 95%CI 1.14-2.24) and have no private health insurance (RRR = 1.53, 95%CI 1.19-1.97 and RRR = 1.65, 95%CI 1.16-2.37) than the 'major city group' (49%). However, the 'inner regional group' reported lower pain severity and better mental health relative to the 'major city group' = 0.92, 95%CI 0.86-0.98 and RRR = 1.02, 95%CI 1.01-1.03, respectively). Although rates of health service access were generally similar, the 'outer regional/remote group' were more likely to report client-practitioner communication problems (RRR = 1.57, 95%CI 1.03-2.37), difficulties accessing specialists (RRR = 1.56, 95%CI 1.01-2.39), and perception of practitioner lack of confidence in prescribing pain medication (RRR = 1.73, 1.14-2.62), relative to both groups. Perceived communication, access, and financial barriers to healthcare indicate the need for increased efforts to address geographic inequality in pain treatment. © 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Pigmented-MDCK (P-MDCK) Cell Line with Tunable Melanin Expression: An In Vitro Model for the Outer Blood-Retinal-Barrier

PubMed Central

Kadam, Rajendra S.; Scheinman, Robert. I.; Kompella, Uday B.

2013-01-01

Purpose Retinal pigment epithelium, which forms the outer blood-retinal-barrier, is a critical barrier for transport of drugs to the retina. The purpose of this study was to develop a pigmented MDCK (P-MDCK) cell line as a rapidly established in vitro model for the outer blood-retinal-barrier to assess the influence of melanin pigment on solute permeability. Methods A melanin synthesizing P-MDCK cell line was developed by lentiviral transduction of human tyrosinase and p-protein genes in MDCK (NBL-2) cells. Melanin content, tyrosinase activity (conversion of L-dopa to dopachrome), and transepithelial electrical resistance (TEER) were measured. Expression of tyrosinase protein and p-protein in P-MDCK cells was confirmed by confocal microscopy. Effect of L-tyrosine (0 to 2 mM) in culture medium on melanin synthesis in P-MDCK cells was evaluated. Cell uptake and transepithelial transport of pigment-binding chloroquine (Log D = 1.59) and a negative control salicylic acid (Log D = −1.14) were investigated. Results P-MDCK cells expressed tyrosinase and p-protein. Tyrosinase activity was 4.5 fold higher in P-MDCK cells as compared to wild-type MDCK cells. The transepithelial electrical resistance stabilized by day 4 in both cell types, with the TEER being 871 ± 30 and 876 ± 53 Ω.cm2 for P-MDCK and wild-type cells, respectively. Melanin content in P-MDCK cells depended on the concentration of L-tyrosine in culture medium, and increased from 3 to 54 µg/mg protein with an increase in L-tyrosine content from 0 to 2 mM. When the cells were grown in 2 mM L-tyrosine, uptake of chloroquine was 2.3 fold higher and the transepithelial transport was 2.2 fold lower in P-MDCK cells when compared to wild-type MDCK cells. No significant difference was observed for both cell uptake and transport of salicylic acid. Conclusions We developed a P-MDCK cell line with tunable melanin synthesis as a rapidly developing surrogate for retinal pigment epithelium. PMID:23003570

Use of separate ZnTe interface layers to form ohmic contacts to p-CdTe films

DOEpatents

Gessert, T.A.

1999-06-01

A method of is disclosed improving electrical contact to a thin film of a p-type tellurium-containing II-VI semiconductor comprising: depositing a first undoped layer of ZnTe on a thin film of p-type tellurium containing II-VI semiconductor with material properties selected to limit the formation of potential barriers at the interface between the p-CdTe and the undoped layer, to a thickness sufficient to control diffusion of the metallic-doped ZnTe into the p-type tellurium-containing II-VI semiconductor, but thin enough to minimize affects of series resistance; depositing a second heavy doped p-type ZnTe layer to the first layer using an appropriate dopant; and depositing an appropriate metal onto the outer-most surface of the doped ZnTe layer for connecting an external electrical conductor to an ohmic contact. 11 figs.

Use of separate ZnTe interface layers to form OHMIC contacts to p-CdTe films

DOEpatents

Gessert, Timothy A.

1999-01-01

A method of improving electrical contact to a thin film of a p-type tellurium-containing II-VI semiconductor comprising: depositing a first undoped layer of ZnTe on a thin film of p-type tellurium containing II-VI semiconductor with material properties selected to limit the formation of potential barriers at the interface between the p-CdTe and the undoped layer, to a thickness sufficient to control diffusion of the metallic-doped ZnTe into the p-type tellurim-containing II-VI semiconductor, but thin enough to minimize affects of series resistance; depositing a second heavy doped p-type ZnTe layer to the first layer using an appropriate dopant; and depositing an appropriate metal onto the outer-most surface of the doped ZnTe layer for connecting an external electrical conductor to an ohmic contact.

Barrier Island Sensitivity to Sea-Level Rise: Insights from Numerical Model Experiments, North Carolina Outer Banks and Chandeleur Islands, LA U.S.A

NASA Astrophysics Data System (ADS)

Moore, L. J.; List, J. H.; Williams, S.; Patsch, K.

2009-12-01

As dynamic and low-lying coastal landforms, barrier islands are especially vulnerable to sea level rise, changes in sediment supply and coastal storms. Changes in these factors may ultimately result in new conditions that are sufficiently different from present to cause a shift in equilibrium state from landward-migrating to submerging, i.e., a threshold crossing. Because the loss of barrier islands would be extremely disruptive of human activities, an understanding of how barrier islands evolve under conditions of rising sea level is vital to the development of wise coastal management practices. To advance understanding of barrier island response to changing conditions, we apply the morphological-behavior model GEOMBEST (GEOmorphic Model of Barrier and EStuarine Translations; Stolper et al., 2005, Moore et al., 2007 and Moore et al., accepted pending minor revisions) to field sites in the North Carolina Outer Banks and the Chandeleur Islands of southeastern Louisiana. Sensitivity analyses reveal that, in general, substrate sand proportion, substrate slope, sea-level rise rate and sediment-supply rate are the most important factors in determining barrier island response to sea-level rise while shoreface erosion rates, substrate erodibility, and shoreface depth are often less important. More specifically, substrate composition appears to be the most important factor in muddy coastal environments, such as the Chandeleur Islands, where model results suggest that a threshold crossing may occur on the order of decades to a century from present, while the other three factors appear to be most important in North Carolina and other similar environments. When substrate sand proportions are low and/or sediment-loss rates are high, shoreface erosion rate and substrate erodibility may become important in limiting the rate at which sand can be liberated from the substrate, thereby increasing barrier island vulnerability to threshold crossing. Barrier system history (e.g., previous sediment supply rates, substrate slope) determines barrier island volume and the degree to which the shoreface extends into the substrate, and is therefore of critical importance in determining whether or not a barrier will persist as sea-level rises. Surprisingly, larger barriers, which are associated with little incision into the substrate, are more vulnerable to sea-level rise than smaller barriers that have been losing sand in the past, or that have encountered rapidly changing substrate slopes. Overall, our results indicate that barrier islands with muddy substrates, and barriers which are in near-equilibrium with substrate slope, will be most vulnerable to geomorphic threshold crossing as sea level rises. Plans to merge GEOMBEST with a marsh progradation model will allow a more detailed assessment of barrier island response where co-evolution of back-barrier marsh and barrier environments is critical in determining the conditions under which threshold crossings are most likely.

Low-Outgassing Photogrammetry Targets for Use in Outer Space

NASA Technical Reports Server (NTRS)

Gross, Jason N.; Sampler, Henry; Reed, Benjamin B.

2011-01-01

A short document discusses an investigation of materials for photogrammetry targets for highly sensitive optical scientific instruments to be operated in outer space and in an outer-space-environment- simulating thermal vacuum chamber on Earth. A key consideration in the selection of photogrammetry-target materials for vacuum environments is the need to prevent contamination that could degrade the optical responses of the instruments. Therefore, in addition to the high levels and uniformity of reflectivity required of photogrammetry-target materials suitable for use in air, the materials sought must exhibit minimal outgassing. Commercially available photogrammetry targets were found to outgas excessively under the thermal and vacuum conditions of interest; this finding prompted the investigators to consider optically equivalent or superior, lower-outgassing alternative target materials. The document lists several materials found to satisfy the requirements, but does not state explicitly whether the materials can be used individually or must be combined in the proper sequence into layered target structures. The materials in question are an aluminized polyimide tape, an acrylic pressure- sensitive adhesive, a 500-A-thick layer of vapor-deposited aluminum, and spherical barium titanate glass beads having various diameters from 20 to 63 microns..

ETR, TRA642. ON GROUND FLOOR. WITH OUTER THERMAL RING IN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

ETR, TRA-642. ON GROUND FLOOR. WITH OUTER THERMAL RING IN PLACE AND CONDUIT PRESERVED, HIGH-DENSITY CONCRETE IS PLACED BETWEEN THE THERMAL RING AND THE OUTER REACTOR FORM. INL NEGATIVE NO. 56-2400. Jack L. Anderson, Photographer, 6/10/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Studies of volatiles and organic materials in early terrestrial and present-day outer solar system environments

NASA Technical Reports Server (NTRS)

Sagan, Carl; Thompson, W. Reid; Chyba, Christopher F.; Khare, B. N.

1991-01-01

A review and partial summary of projects within several areas of research generally involving the origin, distribution, chemistry, and spectral/dielectric properties of volatiles and organic materials in the outer solar system and early terrestrial environments are presented. The major topics covered include: (1) impact delivery of volatiles and organic compounds to the early terrestrial planets; (2) optical constants measurements; (3) spectral classification, chemical processes, and distribution of materials; and (4) radar properties of ice, hydrocarbons, and organic heteropolymers.

Basic approaches to and tasks of space technology

NASA Technical Reports Server (NTRS)

Okhotin, A. S.

1978-01-01

The high vacuum and weightlessness of outer space offer great possibilities for the new field of space technology. To take advantage of this, it is necessary to study such physical and chemical phenomena as diffusion, surface tension, heat exchange, and crystallization. The research shows the possibility of obtaining materials with a more perfect structure. Methods of treating materials can be used in space which are impossible on earth. Achievements in material science in outer space will have a large impact on the national economy.

Role of Geologic Framework, Paleotopography, Sediment Supply, and Human Modification in the Evolutionary Development of the Northeastern North Carolina Barrier Island System

NASA Astrophysics Data System (ADS)

Riggs, S. R.; Thieler, E. R.; Mallinson, D. A.; Culver, S. J.; Corbett, D. R.; Hoffman, C. W.

2002-12-01

The NE North Carolina coastal system contains an exceptionally thick and well preserved Quaternary stratigraphic record that is the focus of a five-year Cooperative Coastal Geology Program between the USGS, several academic institutions, and state agencies. The major goal is to map this Quaternary section on the inner continental shelf, Outer Banks barrier islands, Albemarle-Pamlico estuarine system, and adjacent land areas. The program objectives are to define the geologic framework, develop the detailed evolutionary history, and understand the ongoing process dynamics driving this large, complex, and rapidly changing, high-energy coastal system. Preliminary data synthesis demonstrates that the major controls dictating the present health and future evolution of this coastal system include the following. 1) The regional late Pleistocene morphology constitutes the underlying geologic framework that the Holocene system has inherited. 2) The controlling paleotopography is a series of lowstand drainage basins consisting of trunk and tributary streams and associated interstream divides that are being drowned. 3) Three major sediment sources dictate the highly variable sand resources available to specific barrier segments and include riverine channel and deltaic deposits associated with lowstand trunk streams, the large cross-shelf cape shoal sand deposits, and sand-rich units occurring within the adjacent shoreface and inner-self strata. 4) Wherever large sand supplies have historically been available, the barrier segments occur as complex islands with large sand volumes producing high and wide barriers, whereas barrier segments without adequate sand supplies are sediment starved and occur as simple overwash barriers. 5) Human modification of the barrier islands over the past seven decades represents a major force that has significantly changed the barrier island dynamics and evolution. 6) The Albemarle Embayment appears to have a slightly higher rate of sea-level rise than adjacent regions due to a slow rate of regional subsidence. Consequently, if the ongoing pattern of storm activity and sea-level rise either continues or increases during the next few decades to centuries, several simple overwash barrier segments on the Outer Banks, that are currently disintegrating, will ultimately collapse into Pamlico Sound. These barrier segments will likely back-step across the open marine Pamlico Embayment and reform on the landward side. A few sand-rich complex barrier segments will persist as isolated, but perched and eroding islands for some longer period of time. In contrast, simple overwash barrier segments that have received minimal human modification and are associated with narrow and shallow back-barrier sounds, appear to be maintaining themselves in their upward and landward migration in response to ongoing storms and sea-level rise.

Nose-only exposure system

DOEpatents

Cannon, William C.; Bass, Edward W.; Decker, Jr., John R.

1988-01-01

An exposure system for supplying a gaseous material, i.e. an aerosol, gas or a vapor, directly to the noses of experimental animals includes concentric vertical inner and outer manifolds. The outer manifold connects with the necks of a large number of bottles in which the animals are confined with their noses adjacent the bottle necks. Readily detachable small tubes communicate with the inner manifold and extend to the necks of the bottles. The upper end of the outer manifold and the lower end of the inner manifold are closed. Gaseous material is supplied to the upper end of the inner manifold, flows through the small tubes to points adjacent the noses of the individual animals, then is drawn out through the bottom of the outer manifold. The bottles are readily removable and the device can be disassembled, e.g., for cleaning, by removing the bottles, removing the small tubes, and lifting the inner manifold from the outer manifold. The bottles are supported by engagement of their necks with the outer manifold supplemented, if additional support is required, by individual wire cradles. The outer ends of the bottles are closed by plugs, through which pass metal tubes which receive the tails of the animals (usually rodents) and which serve to dissipate body heat. The entire device is mounted for rotation on turntable bearings.

Method for forming a liquid cooled airfoil for a gas turbine

DOEpatents

Grondahl, Clayton M.; Willmott, Leo C.; Muth, Myron C.

1981-01-01

A method for forming a liquid cooled airfoil for a gas turbine is disclosed. A plurality of holes are formed at spaced locations in an oversized airfoil blank. A pre-formed composite liquid coolant tube is bonded into each of the holes. The composite tube includes an inner member formed of an anti-corrosive material and an outer member formed of a material exhibiting a high degree of thermal conductivity. After the coolant tubes have been bonded to the airfoil blank, the airfoil blank is machined to a desired shape, such that a portion of the outer member of each of the composite tubes is contiguous with the outer surface of the machined airfoil blank. Finally, an external skin is bonded to the exposed outer surface of both the machined airfoil blank and the composite tubes.

Photoconductive switch package

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

Caporaso, George J.

2015-10-27

A photoconductive switch is formed of a substrate that has a central portion of SiC or other photoconductive material and an outer portion of cvd-diamond or other suitable material surrounding the central portion. Conducting electrodes are formed on opposed sides of the substrate, with the electrodes extending beyond the central portion and the edges of the electrodes lying over the outer portion. Thus any high electric fields produced at the edges of the electrodes lie outside of and do not affect the central portion, which is the active switching element. Light is transmitted through the outer portion to the centralmore » portion to actuate the switch.« less

The Free Energy of Small Solute Permeation through the Escherichia coli Outer Membrane Has a Distinctly Asymmetric Profile

DOE PAGES

Carpenter, Timothy S.; Parkin, Jamie; Khalid, Syma

2016-08-12

Permeation of small molecules across cell membranes is a ubiquitous process in biology and is dependent on the principles of physical chemistry at the molecular level. Here we use atomistic molecular dynamics simulations to calculate the free energy of permeation of a range of small molecules through a model of the outer membrane of Escherichia coli, an archetypical Gram-negative bacterium. The model membrane contains lipopolysaccharide (LPS) molecules in the outer leaflet and phospholipids in the inner leaflet. Our results show that the energetic barriers to permeation through the two leaflets of the membrane are distinctly asymmetric; the LPS headgroups providemore » a less energetically favorable environment for organic compounds than do phospholipids. In summary, we provide the first reported estimates of the relative free energies associated with the different chemical environments experienced by solutes as they attempt to cross the outer membrane of a Gram-negative bacterium. Furthermore, these results provide key insights for the development of novel antibiotics that target these bacteria.« less

The Free Energy of Small Solute Permeation through the Escherichia coli Outer Membrane Has a Distinctly Asymmetric Profile

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

Carpenter, Timothy S.; Parkin, Jamie; Khalid, Syma

Permeation of small molecules across cell membranes is a ubiquitous process in biology and is dependent on the principles of physical chemistry at the molecular level. Here we use atomistic molecular dynamics simulations to calculate the free energy of permeation of a range of small molecules through a model of the outer membrane of Escherichia coli, an archetypical Gram-negative bacterium. The model membrane contains lipopolysaccharide (LPS) molecules in the outer leaflet and phospholipids in the inner leaflet. Our results show that the energetic barriers to permeation through the two leaflets of the membrane are distinctly asymmetric; the LPS headgroups providemore » a less energetically favorable environment for organic compounds than do phospholipids. In summary, we provide the first reported estimates of the relative free energies associated with the different chemical environments experienced by solutes as they attempt to cross the outer membrane of a Gram-negative bacterium. Furthermore, these results provide key insights for the development of novel antibiotics that target these bacteria.« less

Suppressing electron turbulence and triggering internal transport barriers with reversed magnetic shear in the National Spherical Torus Experimenta)

NASA Astrophysics Data System (ADS)

Peterson, J. L.; Bell, R.; Candy, J.; Guttenfelder, W.; Hammett, G. W.; Kaye, S. M.; LeBlanc, B.; Mikkelsen, D. R.; Smith, D. R.; Yuh, H. Y.

2012-05-01

The National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 (2000)] can achieve high electron plasma confinement regimes that are super-critically unstable to the electron temperature gradient driven (ETG) instability. These plasmas, dubbed electron internal transport barriers (e-ITBs), occur when the magnetic shear becomes strongly negative. Using the gyrokinetic code GYRO [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)], the first nonlinear ETG simulations of NSTX e-ITB plasmas reinforce this observation. Local simulations identify a strongly upshifted nonlinear critical gradient for thermal transport that depends on magnetic shear. Global simulations show e-ITB formation can occur when the magnetic shear becomes strongly negative. While the ETG-driven thermal flux at the outer edge of the barrier is large enough to be experimentally relevant, the turbulence cannot propagate past the barrier into the plasma interior.

In situ cell surface proteomics reveals differentially expressed membrane proteins in retinal pigment epithelial cells during autoimmune uveitis.

PubMed

Uhl, P B; Szober, C M; Amann, B; Alge-Priglinger, C; Ueffing, M; Hauck, S M; Deeg, C A

2014-09-23

Retinal pigment epithelium (RPE) builds the outer blood-retinal barrier of the eye and plays an important role in pathogenesis of the sight threatening disease equine recurrent uveitis (ERU). ERU is a spontaneous autoimmune mediated inflammatory disease characterised by the breakdown of the outer blood-retinal barrier and an influx of autoaggressive T-cells into the inner eye. Therefore, identification of molecular mechanisms contributing to changed function of blood-retinal barrier in ERU is important for the understanding of pathophysiology. Cell surface proteins of RPE collected from healthy horses and horses with ERU were captured by in situ biotinylation and analysed with high resolution mass spectrometry coupled to liquid chromatography (LC-MS/MS) to identify differentially expressed proteins. With label free differential proteomics, a total of 27 differently expressed cell surface proteins in diseased RPE could be detected. Significant down-regulation of three very interesting proteins, synaptotagmin 1, basigin and collectrin was verified and further characterised. We applied an innovative and successful method to detect changes in the plasma cell surface proteome of RPE cells in a spontaneous inflammatory eye disease, serving as a valuable model for human autoimmune uveitis. We were able to identify 27 differentially expressed plasma cell membrane proteins, including synaptotagmin 1, basigin and collectrin, which play important roles in cell adhesion, transport and cell communication. Copyright © 2014 Elsevier B.V. All rights reserved.

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants.

PubMed

Simal-Gándara, J; Sarria-Vidal, M; Koorevaar, A; Rijk, R

2000-08-01

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick oriented PP) into the food stimulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.

Barriers on the brink? The complex intertwined roles of geologic framework, sediment availability and sea-level rise in island evolution

USGS Publications Warehouse

Moore, Laura; List, Jeffrey H.; Williams, S. Jeffress; Patsch, Kiki; Rosati, Julie D.; Wang, Ping; Roberts, Tiffany M.

2011-01-01

Sensitivity experiments in the North Carolina Outer Banks (OBX) have previously revealed that substrate sand proportion, followed by substrate slope, sea-level rise rate and sediment-loss rate are the most important factors in determining how barrier islands respond to sea-level rise. High sediment-loss rates and low substrate sand proportions cause barriers to be smaller and more deeply incised. Thus, as sea level rise rates increase, more deeply incised barriers do not need to migrate as far landward as larger, less-incised barriers to liberate sand from the shoreface. However, if the combination of sand losses and substrate sand proportions requires a barrier to migrate landward faster than the shoreface can erode to replenish losses, a barrier will change state and begin to disintegrate. Because the substrate of the OBXis sand-rich, these barriers are likely to persist in the near-term. In contrast, model simulations for the Chandeleur Islands, Louisiana suggest sediment loss rates are too high and/or substrate sand proportions are too low to be matched by liberation of shoreface sand. These simulations further suggest that a state change, from a landward-migrating barrier system to a subaqueous shoal complex, is either already underway or imminent.

Impact of energetic-particle-driven geodesic acoustic modes on turbulence.

PubMed

Zarzoso, D; Sarazin, Y; Garbet, X; Dumont, R; Strugarek, A; Abiteboul, J; Cartier-Michaud, T; Dif-Pradalier, G; Ghendrih, Ph; Grandgirard, V; Latu, G; Passeron, C; Thomine, O

2013-03-22

The impact on turbulent transport of geodesic acoustic modes excited by energetic particles is evidenced for the first time in flux-driven 5D gyrokinetic simulations using the Gysela code. Energetic geodesic acoustic modes (EGAMs) are excited in a regime with a transport barrier in the outer radial region. The interaction between EGAMs and turbulence is such that turbulent transport can be enhanced in the presence of EGAMs, with the subsequent destruction of the transport barrier. This scenario could be particularly critical in those plasmas, such as burning plasmas, exhibiting a rich population of suprathermal particles capable of exciting energetic modes.

Outer Membrane Permeability of Cyanobacterium Synechocystis sp. Strain PCC 6803: Studies of Passive Diffusion of Small Organic Nutrients Reveal the Absence of Classical Porins and Intrinsically Low Permeability

PubMed Central

Kowata, Hikaru; Tochigi, Saeko; Takahashi, Hideyuki

2017-01-01

ABSTRACT The outer membrane of heterotrophic Gram-negative bacteria plays the role of a selective permeability barrier that prevents the influx of toxic compounds while allowing the nonspecific passage of small hydrophilic nutrients through porin channels. Compared with heterotrophic Gram-negative bacteria, the outer membrane properties of cyanobacteria, which are Gram-negative photoautotrophs, are not clearly understood. In this study, using small carbohydrates, amino acids, and inorganic ions as permeation probes, we determined the outer membrane permeability of Synechocystis sp. strain PCC 6803 in intact cells and in proteoliposomes reconstituted with outer membrane proteins. The permeability of this cyanobacterium was >20-fold lower than that of Escherichia coli. The predominant outer membrane proteins Slr1841, Slr1908, and Slr0042 were not permeable to organic nutrients and allowed only the passage of inorganic ions. Only the less abundant outer membrane protein Slr1270, a homolog of the E. coli export channel TolC, was permeable to organic solutes. The activity of Slr1270 as a channel was verified in a recombinant Slr1270-producing E. coli outer membrane. The lack of putative porins and the low outer membrane permeability appear to suit the cyanobacterial autotrophic lifestyle; the highly impermeable outer membrane would be advantageous to cellular survival by protecting the cell from toxic compounds, especially when the cellular physiology is not dependent on the uptake of organic nutrients. IMPORTANCE Because the outer membrane of Gram-negative bacteria affects the flux rates for various substances into and out of the cell, its permeability is closely associated with cellular physiology. The outer membrane properties of cyanobacteria, which are photoautotrophic Gram-negative bacteria, are not clearly understood. Here, we examined the outer membrane of Synechocystis sp. strain PCC 6803. We revealed that it is relatively permeable to inorganic ions but is markedly less permeable to organic nutrients, with >20-fold lower permeability than the outer membrane of Escherichia coli. Such permeability appears to fit the cyanobacterial lifestyle, in which the diffusion pathway for inorganic solutes may suffice to sustain the autotrophic physiology, illustrating a link between outer membrane permeability and the cellular lifestyle. PMID:28696278

Impacts and recovery from severe tropical cyclone Yasi on the Great Barrier Reef.

PubMed

Beeden, Roger; Maynard, Jeffrey; Puotinen, Marjetta; Marshall, Paul; Dryden, Jen; Goldberg, Jeremy; Williams, Gareth

2015-01-01

Full recovery of coral reefs from tropical cyclone (TC) damage can take decades, making cyclones a major driver of habitat condition where they occur regularly. Since 1985, 44 TCs generated gale force winds (≥17 metres/second) within the Great Barrier Reef Marine Park (GBRMP). Of the hurricane strength TCs (≥H1-Saffir Simpson scale; ≥ category 3 Australian scale), TC Yasi (February, 2011) was the largest. In the weeks after TC Yasi crossed the GBRMP, participating researchers, managers and rangers assessed the extent and severity of reef damage via 841 Reef Health and Impact Surveys at 70 reefs. Records were scaled into five damage levels representing increasingly widespread colony-level damage (1, 2, 3) and reef structural damage (4, 5). Average damage severity was significantly affected by direction (north vs south of the cyclone track), reef shelf position (mid-shelf vs outer-shelf) and habitat type. More outer-shelf reefs suffered structural damage than mid-shelf reefs within 150 km of the track. Structural damage spanned a greater latitudinal range for mid-shelf reefs than outer-shelf reefs (400 vs 300 km). Structural damage was patchily distributed at all distances, but more so as distance from the track increased. Damage extended much further from the track than during other recent intense cyclones that had smaller circulation sizes. Just over 15% (3,834 km2) of the total reef area of the GBRMP is estimated to have sustained some level of coral damage, with ~4% (949 km2) sustaining a degree of structural damage. TC Yasi likely caused the greatest loss of coral cover on the GBR in a 24-hour period since 1985. Severely impacted reefs have started to recover; coral cover increased an average of 4% between 2011 and 2013 at re-surveyed reefs. The in situ assessment of impacts described here is the largest in scale ever conducted on the Great Barrier Reef following a reef health disturbance.

Impacts and Recovery from Severe Tropical Cyclone Yasi on the Great Barrier Reef

PubMed Central

Beeden, Roger; Maynard, Jeffrey; Puotinen, Marjetta; Marshall, Paul; Dryden, Jen; Goldberg, Jeremy; Williams, Gareth

2015-01-01

Full recovery of coral reefs from tropical cyclone (TC) damage can take decades, making cyclones a major driver of habitat condition where they occur regularly. Since 1985, 44 TCs generated gale force winds (≥17 metres/second) within the Great Barrier Reef Marine Park (GBRMP). Of the hurricane strength TCs (≥H1—Saffir Simpson scale; ≥ category 3 Australian scale), TC Yasi (February, 2011) was the largest. In the weeks after TC Yasi crossed the GBRMP, participating researchers, managers and rangers assessed the extent and severity of reef damage via 841 Reef Health and Impact Surveys at 70 reefs. Records were scaled into five damage levels representing increasingly widespread colony-level damage (1, 2, 3) and reef structural damage (4, 5). Average damage severity was significantly affected by direction (north vs south of the cyclone track), reef shelf position (mid-shelf vs outer-shelf) and habitat type. More outer-shelf reefs suffered structural damage than mid-shelf reefs within 150 km of the track. Structural damage spanned a greater latitudinal range for mid-shelf reefs than outer-shelf reefs (400 vs 300 km). Structural damage was patchily distributed at all distances, but more so as distance from the track increased. Damage extended much further from the track than during other recent intense cyclones that had smaller circulation sizes. Just over 15% (3,834 km2) of the total reef area of the GBRMP is estimated to have sustained some level of coral damage, with ~4% (949 km2) sustaining a degree of structural damage. TC Yasi likely caused the greatest loss of coral cover on the GBR in a 24-hour period since 1985. Severely impacted reefs have started to recover; coral cover increased an average of 4% between 2011 and 2013 at re-surveyed reefs. The in situ assessment of impacts described here is the largest in scale ever conducted on the Great Barrier Reef following a reef health disturbance. PMID:25874718

Mfsd2a Is a Transporter for the Essential ω-3 Fatty Acid Docosahexaenoic Acid (DHA) in Eye and Is Important for Photoreceptor Cell Development.

PubMed

Wong, Bernice H; Chan, Jia Pei; Cazenave-Gassiot, Amaury; Poh, Rebecca W; Foo, Juat Chin; Galam, Dwight L A; Ghosh, Sujoy; Nguyen, Long N; Barathi, Veluchamy A; Yeo, Sia W; Luu, Chi D; Wenk, Markus R; Silver, David L

2016-05-13

Eye photoreceptor membrane discs in outer rod segments are highly enriched in the visual pigment rhodopsin and the ω-3 fatty acid docosahexaenoic acid (DHA). The eye acquires DHA from blood, but transporters for DHA uptake across the blood-retinal barrier or retinal pigment epithelium have not been identified. Mfsd2a is a newly described sodium-dependent lysophosphatidylcholine (LPC) symporter expressed at the blood-brain barrier that transports LPCs containing DHA and other long-chain fatty acids. LPC transport via Mfsd2a has been shown to be necessary for human brain growth. Here we demonstrate that Mfsd2a is highly expressed in retinal pigment epithelium in embryonic eye, before the development of photoreceptors, and is the primary site of Mfsd2a expression in the eye. Eyes from whole body Mfsd2a-deficient (KO) mice, but not endothelium-specific Mfsd2a-deficient mice, were DHA-deficient and had significantly reduced LPC/DHA transport in vivo Fluorescein angiography indicated normal blood-retinal barrier function. Histological and electron microscopic analysis indicated that Mfsd2a KO mice exhibited a specific reduction in outer rod segment length, disorganized outer rod segment discs, and mislocalization of and reduction in rhodopsin early in postnatal development without loss of photoreceptors. Minor photoreceptor cell loss occurred in adult Mfsd2a KO mice, but electroretinography indicated visual function was normal. The developing eyes of Mfsd2a KO mice had activated microglia and up-regulation of lipogenic and cholesterogenic genes, likely adaptations to loss of LPC transport. These findings identify LPC transport via Mfsd2a as an important pathway for DHA uptake in eye and for development of photoreceptor membrane discs. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Preparation of clenbuterol imprinted monolithic polymer with hydrophilic outer layers by reversible addition-fragmentation chain transfer radical polymerization and its application in the clenbuterol determination from human serum by on-line solid-phase extraction/HPLC analysis.

PubMed

Li, Xiaobing; Zhou, Man; Turson, Mamat; Lin, Shen; Jiang, Ping; Dong, Xiangchao

2013-05-21

A novel imprinted monolithic material with the ability of protein exclusion was developed for the selective extraction of clenbuterol (CLE) from biological samples by direct injection in the HPLC analysis. The material has an imprinted inner structure and hydrophilic outer layer. The reversible addition-fragmentation chain transfer (RAFT) polymerization was employed in the material preparation by a two-step procedure. In the first step, clenbuterol imprinted monolithic polymer was synthesized by combining the molecular imprinting and the RAFT polymerization techniques. The resulting monolithic polymer has a RAFT chain transfer agent (trithioester groups) in its structure, which was used to graft poly(glycerol mono-methacrylate) [pGMMA] in the second step by post-RAFT polymerization. The hydrophilic pGMMA layers grafted on the surface of the imprinted monolith created barriers for protein diffusion. More than 90% of bovine serum albumin can be excluded from the pGMMA coated monolithic column. Meanwhile the clenbuterol was retained selectively with a large retention factor. The result indicated that the column, denoted as RA-MIM, has both the merits of a molecularly imprinted polymer and restricted access material. By using RA-MIM as the solid-phase extraction pre-column, an on-line column-switching HPLC method for the determination of clenbuterol in human serum has been established and validated. The recoveries of clenbuterol from the serum were 87.3-96.9% in the spiked level 2-1000 ng mL(-1). Both good linearity (R = 0.999) and acceptable reproducibility (RSD < 7.0%) were obtained. The limit of detection and the limit of quantitation were 0.7 ng mL(-1) and 2.0 ng mL(-1) respectively, which is sensitive in terms of UV detection. The results have demonstrated that the RAFT polymerization can be used to synthesize bi-functional monolithic columns by using its living reaction property. The resulting RA-MIM in this research can be used for efficient clenbuterol determination by HPLC from biological samples.

Apparatus for assembling space structure

NASA Technical Reports Server (NTRS)

Johnston, J. D.; Tuggle, R. H., Jr.; Burch, J. L.; Clark, K. H. (Inventor)

1978-01-01

An apparatus for producing a structure in outer space from rolls of prepunched ribbon or sheet material that are transported from the earth to the apparatus located in outer space is described. The apparatus spins the space structure similar to a spider spinning a web utilizing the prepunched ribbon material. The prepunched ribbon material is fed through the apparatus and is shaped into a predetermined channel-shaped configuration. Trusses are punched out of the ribbon and are bent downwardly and attached to a track which normally is a previously laid sheet of material. The size of the overall space structure may be increased by merely attaching an additional roll of sheet material to the apparatus.

Disk filter

DOEpatents

Bergman, Werner

1986-01-01

An electric disk filter provides a high efficiency at high temperature. A hollow outer filter of fibrous stainless steel forms the ground electrode. A refractory filter material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer filter surfaces through the electrified refractory filter media and between the high voltage electrodes and is removed from a space in the high voltage electrode.

Glass/Epoxy Door Panel for Automobiles

NASA Technical Reports Server (NTRS)

Bauer, J. L. JR.

1985-01-01

Lightweight panel cost-effective. Integrally-molded intrusion strap key feature of composite outer door panel. Strap replaces bulky and heavy steel instrusion beam of conventional door. Standard steel inner panel used for demonstration purposes. Door redesigned to exploit advantages of composite outer panel thinner. Outer panel for automobilie door, made of glass/epoxy composite material, lighter than conventional steel door panel, meets same strength requirements, and less expensive.

Disk filter

DOEpatents

Bergman, W.

1985-01-09

An electric disk filter provides a high efficiency at high temperature. A hollow outer filter of fibrous stainless steel forms the ground electrode. A refractory filter material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer filter surfaces through the electrified refractory filter media and between the high voltage electrodes and is removed from a space in the high voltage electrode.

Test device for measuring permeability of a barrier material

DOEpatents

Reese, Matthew; Dameron, Arrelaine; Kempe, Michael

2014-03-04

A test device for measuring permeability of a barrier material. An exemplary device comprises a test card having a thin-film conductor-pattern formed thereon and an edge seal which seals the test card to the barrier material. Another exemplary embodiment is an electrical calcium test device comprising: a test card an impermeable spacer, an edge seal which seals the test card to the spacer and an edge seal which seals the spacer to the barrier material.

Cryovolcanism in the outer solar system

USGS Publications Warehouse

Geissler, Paul E.

2015-01-01

Cryovolcanism is defined as the extrusion of liquids and vapors of materials that would be frozen solid at the planetary surface temperatures of the icy bodies of the outer solar system. Active cryovolcanism is now known to occur on Saturn's moon Enceladus and on Neptune's moon Triton and is suspected on Jupiter's moon Europa, while evidence for past cryovolcanic activity is widespread throughout the outer solar system. This chapter examines the mechanisms and manifestations of cryovolcanism, beginning with a review of the materials that make up these unusual ‘‘magmas’’ and the means by which they might erupt and concluding with a volcanologist's tour of the farthest reaches of the solar system.

10 CFR 71.55 - General requirements for fissile material packages.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the outer surface of the packaging; and (iii) No occurrence of an aperture in the outer surface of the... spaces is prevented following application of the tests in paragraphs (f)(1) and (f)(2) of this section...

Mechanically expandable annular seal

DOEpatents

Gilmore, R.F.

1983-07-19

A mechanically expandable annular reusable seal assembly to form an annular hermetic barrier between two stationary, parallel, and planar containment surfaces is described. A rotatable ring, attached to the first surface, has ring wedges resembling the saw-tooth array of a hole saw. Matching seal wedges are slidably attached to the ring wedges and have their motion restricted to be perpendicular to the second surface. Each seal wedge has a face parallel to the second surface. An annular elastomer seal has a central annular region attached to the seal wedges' parallel faces and has its inner and outer circumferences attached to the first surface. A rotation of the ring extends the elastomer seal's central region perpendicularly towards the second surface to create the fluid tight barrier. A counter rotation removes the barrier. 6 figs.

Protective coatings for sensitive materials

DOEpatents

Egert, Charles M.

1997-01-01

An enhanced protective coating to prevent interaction between constituents of the environment and devices that can be damaged by those constituents. This coating is provided by applying a synergistic combination of diffusion barrier and physical barrier materials. These materials can be, for example, in the form of a plurality of layers of a diffusion barrier and a physical barrier, with these barrier layers being alternated. Further protection in certain instances is provided by including at least one layer of a getter material to actually react with one or more of the deleterious constituents. The coating is illustrated by using alternating layers of an organic coating (such as Parylene-C.TM.) as the diffusion barrier, and a metal coating (such as aluminum) as the physical barrier. For best results there needs to be more than one of at least one of the constituent layers.

In-situ formation of multiphase air plasma sprayed barrier coatings for turbine components

DOEpatents

Subramanian, Ramesh

2001-01-01

A turbine component (10), such as a turbine blade, is provided which is made of a metal alloy (22) and a base, planar-grained thermal barrier layer (28) applied by air plasma spraying on the alloy surface, where a heat resistant ceramic oxide overlay material (32') covers the bottom thermal barrier coating (28), and the overlay material is the reaction product of the precursor ceramic oxide overlay material (32) and the base thermal barrier coating material (28).

Shoreline configuration and shoreline dynamics: A mesoscale analysis. [Assateague Island and Outer Banks of North Carolina

NASA Technical Reports Server (NTRS)

Dolan, R. (Principal Investigator); Hayden, B. P.; Heywood, J. E.

1975-01-01

The author has identified the following significant results. Atlantic coast barrier island shorelines are seldom straight, but rather sinuous. These shoreline curvatures range in size from cusps to capes. Significant relationships exist between the orientation of shoreline segments within the larger of these sinuous features and shoreline dynamics, with coefficients ranging up to .9. Orientation of the shoreline segments of Assateague Island (60 km) and the Outer Banks of North Carolina (130 km) was measured from LANDSAT 2 imagery (1:80,000) and high altitude aerial photography (1:120,000). Long term trends in shoreline dynamics were established by mapping shoreline and storm-surge penetration changes.

Organic Solid Matter as a Coloring Agent in Outer Solar System Bodies

NASA Technical Reports Server (NTRS)

Cruikshank, D. P.; DalleOre, C. M.; Roush, T. L.; Khare, B. N.; Fonda, Mark (Technical Monitor)

2002-01-01

Small bodies in the outer Solar System OSS, exhibit a range of color, or slope of the reflectance in the photovisual spectral region, ranging from neutral to very red, sometimes with and sometimes without distinct absorption bands. These objects range in geometric albedo from 0.03 to 1.0, with the higher albedo objects typically showing clear evidence of water ice. Water ice has also been found in a few objects with albedo 0. 1 or less. We explore here the identification of the material or materials that color these icy and non-icy surfaces through scattering models that incorporate minerals, meteoritic material, and organic solids (tholins) produced ID the laboratory by energy deposition in ices and gases. These models must match not only the color in the photovisual region, but the spectral reflectance properties throughout the near-infrared. Among some classes of objects, such as Kuiper Belt objects, the coloring agent may be a single material that is present in greater or lesser abundance, thus accounting for the range in color from neutral to very red. This may also apply to the Centaur objects, the Jovian Trojans, and the outer-main belt asteroids, each taken as a separate class. If so, each class may be colored to varying degrees by a different material, or they all might be colored by a common material that is widespread throughout the OSS, from 3 to 50 AU, and beyond. In this paper, we model the reflectances of "Kuiper Belt objects, Centaurs, Trojans, outer ARAB asteroids, and planetary satellites. Our models show that the reddest surfaces cannot be colored by minerals or meteoritic materials, but can be matched throughout the photovisual and near-infrared by organic solids, specifically certain tholins.

Probing effects of pH change on dynamic response of Claudin-2 mediated adhesion using single molecule force spectroscopy.

PubMed

Lim, Tong Seng; Vedula, Sri Ram Krishna; Hui, Shi; Kausalya, P Jaya; Hunziker, Walter; Lim, Chwee Teck

2008-08-15

Claudins belong to a large family of transmembrane proteins that localize at tight junctions (TJs) where they play a central role in regulating paracellular transport of solutes and nutrients across epithelial monolayers. Their ability to regulate the paracellular pathway is highly influenced by changes in extracellular pH. However, the effect of changes in pH on the strength and kinetics of claudin mediated adhesion is poorly understood. Using atomic force microscopy, we characterized the kinetic properties of homophilic trans-interactions between full length recombinant GST tagged Claudin-2 (Cldn2) under different pH conditions. In measurements covering three orders of magnitude change in force loading rate of 10(2)-10(4) pN/s, the Cldn2/Cldn2 force spectrum (i.e., unbinding force versus loading rate) revealed a fast and a slow loading regime that characterized a steep inner activation barrier and a wide outer activation barrier throughout pH range of 4.5-8. Comparing to the neutral condition (pH 6.9), differences in the inner energy barriers for the dissociation of Cldn2/Cldn2 mediated interactions at acidic and alkaline environments were found to be <0.65 k(B)T, which is much lower than the outer dissociation energy barrier (>1.37 k(B)T). The relatively stable interaction of Cldn2/Cldn2 in neutral environment suggests that electrostatic interactions may contribute to the overall adhesion strength of Cldn2 interactions. Our results provide an insight into the changes in the inter-molecular forces and adhesion kinetics of Cldn2 mediated interactions in acidic, neutral and alkaline environments.

Development of Thermal Bridging Factors for Use in Energy Models

DTIC Science & Technology

2015-06-20

assemblies. 5.2.2 Drainage : Drained systems Drained (Figure 5-6) and screened enclosures assume some rainwater will penetrate the outer surface...38 5.2.2 Drainage : Drained systems ...layer (e.g., drainage plane and gap or waterproofing) 2. Airflow control layer (e.g., an air barrier system ) 3. Thermal control layer (e.g., insulation

Shakeoff Ionization near the Coulomb Barrier Energy.

PubMed

Sharma, Prashant; Nandi, T

2017-11-17

We measure the projectile K x-ray spectra as a function of the beam energies around the Coulomb barrier in different collision systems. The energy is scanned in small steps around the barrier aiming to explore the nuclear effects on the elastically scattered projectile ions. The variation of the projectile x-ray energy with the ion-beam energies exhibits an unusual increase in between the interaction barrier and fusion barrier energies. This additional contribution to the projectile ionization can be attributed to the shakeoff of outer-shell electrons of the projectile ions due to the sudden nuclear recoil (∼10^{-21}  sec) caused by the attractive nuclear potential, which gets switched on near the interaction barrier energy. In the sudden approximation limit, the theoretical shakeoff probability calculation due to the nuclear recoil explains the observed data well. In addition to its fundamental interest, such processes can play a significant role in dark matter detection through the possible mechanism of x-ray emissions, where the weakly interacting massive particle-nucleus elastic scattering can lead to the nuclear-recoil-induced inner-shell vacancy creations. Furthermore, the present work may provide new prospects for atomic physics research at barrier energies as well as provide a novel technique to perform barrier distribution studies for two-body systems.

Shakeoff Ionization near the Coulomb Barrier Energy

NASA Astrophysics Data System (ADS)

Sharma, Prashant; Nandi, T.

2017-11-01

We measure the projectile K x-ray spectra as a function of the beam energies around the Coulomb barrier in different collision systems. The energy is scanned in small steps around the barrier aiming to explore the nuclear effects on the elastically scattered projectile ions. The variation of the projectile x-ray energy with the ion-beam energies exhibits an unusual increase in between the interaction barrier and fusion barrier energies. This additional contribution to the projectile ionization can be attributed to the shakeoff of outer-shell electrons of the projectile ions due to the sudden nuclear recoil (˜10-21 sec ) caused by the attractive nuclear potential, which gets switched on near the interaction barrier energy. In the sudden approximation limit, the theoretical shakeoff probability calculation due to the nuclear recoil explains the observed data well. In addition to its fundamental interest, such processes can play a significant role in dark matter detection through the possible mechanism of x-ray emissions, where the weakly interacting massive particle-nucleus elastic scattering can lead to the nuclear-recoil-induced inner-shell vacancy creations. Furthermore, the present work may provide new prospects for atomic physics research at barrier energies as well as provide a novel technique to perform barrier distribution studies for two-body systems.

Catalytic thermal barrier coatings

DOEpatents

Kulkarni, Anand A.; Campbell, Christian X.; Subramanian, Ramesh

2009-06-02

A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

Transmission electron microscopy of coatings formed by plasma electrolytic oxidation of titanium.

PubMed

Matykina, E; Arrabal, R; Skeldon, P; Thompson, G E

2009-05-01

Transmission electron microscopy and supporting film analyses are used to investigate the changes in composition, morphology and structure of coatings formed on titanium during DC plasma electrolytic oxidation in a calcium- and phosphorus-containing electrolyte. The coatings are of potential interest as bioactive surfaces. The initial barrier film, of mixed amorphous and nanocrystalline structure, formed below the sparking voltage of 180 V, incorporates small amounts of phosphorus and calcium species, with phosphorus confined to the outer approximately 63% of the coating thickness. On commencement of sparking, calcium- and phosphorus-rich amorphous material forms at the coating surface, with local heating promoting crystallization in underlying and adjacent anodic titania. The amorphous material thickens with increased treatment time, comprising almost the whole of the approximately 5.7-microm-thick coating formed at 340 V. At this stage, the coating is approximately 4.4 times thicker than the oxidized titanium, with a near-surface composition of about 12 at.% Ti, 58 at.% O, 19 at.% P and 11 at.% Ca. Further, the amount of titanium consumed in forming the coating is similar to that calculated from the anodizing charge, although there may be non-Faradaic contributions to the coating growth.

Functions of an engineered barrier system for a nuclear waste repository in basalt

NASA Astrophysics Data System (ADS)

Coons, W. E.; Moore, E. L.; Smith, M. J.; Kaser, J. D.

1980-01-01

The functions of components selected for an engineered barrier system for a nuclear waste repository in basalt are defined providing a focal point for barrier material research and development by delineating the purpose and operative lifetime of each component of the engineered system. A five component system (comprised of waste form, canister, buffer, overpack, and tailored backfill) is discussed. Redundancy is provided by subsystems of physical and chemical barriers which act in concert with the geology to provide a formidable barrier to transport of hazardous materials to the biosphere. The barrier system is clarified by examples pertinent to storage in basalt, and a technical approach to barrier design and material selection is proposed.

Positive contact, self retaining bearing seals

DOEpatents

Johnson, Bruce H.; Larsen, Lawrence E.; Welch, Edmund F.

1992-05-05

An ultra-low friction bearing including an inner race, an outer race, bearing elements engaged between the inner and outer races and a seal between the inner and outer races is disclosed. The seal includes first and second sealing washers. The first washer has an outer diameter greater than an inner diameter of the outer race and an inner diameter greater than the outer diameter of the inner race. The second washer has an inner diameter less than the outer diameter of the inner race and an outer diameter less than the inner diameter of the outer race. The first washer slidably engages the outer race, the second washer slidably engages the inner race and the washers overlap and slidably engage one another. One of the washers snap fits into its respective inner or outer race while the other washer engages a stepped surface of the other of the inner and outer races. The grooved and stepped surface are offset from one another in a longitudinal direction of the races such that the washers are conically loaded thus providing a seal between the inner and outer races sufficient to prevent lubricant and contaminating particles from passing therethrough. The washers are made from a non-metallic semi-flexible low-modulus material.

Protective coatings for sensitive materials

DOEpatents

Egert, C.M.

1997-08-05

An enhanced protective coating is disclosed to prevent interaction between constituents of the environment and devices that can be damaged by those constituents. This coating is provided by applying a synergistic combination of diffusion barrier and physical barrier materials. These materials can be, for example, in the form of a plurality of layers of a diffusion barrier and a physical barrier, with these barrier layers being alternated. Further protection in certain instances is provided by including at least one layer of a getter material to actually react with one or more of the deleterious constituents. The coating is illustrated by using alternating layers of an organic coating (such as Parylene-C{trademark}) as the diffusion barrier, and a metal coating (such as aluminum) as the physical barrier. For best results there needs to be more than one of at least one of the constituent layers. 4 figs.

Lih thermal energy storage device

DOEpatents

Olszewski, Mitchell; Morris, David G.

1994-01-01

A thermal energy storage device for use in a pulsed power supply to store waste heat produced in a high-power burst operation utilizes lithium hydride as the phase change thermal energy storage material. The device includes an outer container encapsulating the lithium hydride and an inner container supporting a hydrogen sorbing sponge material such as activated carbon. The inner container is in communication with the interior of the outer container to receive hydrogen dissociated from the lithium hydride at elevated temperatures.

Global Evolution of Plasmaspheric Plasma: Spacecraft-Model Reconstructions

NASA Astrophysics Data System (ADS)

Walsh, B.; Welling, D. T.; Morley, S.

2017-12-01

During times of geomagnetic disturbance, material from the plasmasphere will move radially outward into the magnetosphere. Once introduced to the outer magnetosphere, this material has been shown to impact a variety of plasma populations as well as the coupling of energy from the solar wind into the magnetosphere and ionosphere. The magnitude of any of these effects is inherently linked to the density and evolution of the plasmaspheric plasma. Much of our idea of how this population behaves in the outer-magnetosphere is however based on statistical pictures and model results. Here, in-situ measurements from 10 spacecraft are used to constrain a coupled, global numerical modeling in order to identify true spatial extents, time histories, and densities of the plasmasphere and plumes in the outer magnetosphere.

Methods and Apparatus for Detecting Defects in an Object of Interest

NASA Technical Reports Server (NTRS)

Hartman, John K. (Inventor); Pearson, Lee H (Inventor)

2017-01-01

A method for detecting defects in an object of interest comprises applying an ultrasonic signal including a tone burst having a predetermined frequency and number of cycles into an object of interest, receiving a return signal reflected from the object of interest, and processing the return signal to detect defects in at least one inner material. The object may have an outer material and the at least one inner material that have different acoustic impedances. An ultrasonic sensor system includes an ultrasonic sensor configured to generate an ultrasonic signal having a tone burst at a predetermined frequency corresponding to a resonant frequency of an outer material of an object of interest.

Electrodes for microfluidic applications

DOEpatents

Crocker, Robert W [Fremont, CA; Harnett, Cindy K [Livermore, CA; Rognlien, Judith L [Livermore, CA

2006-08-22

An electrode device for high pressure applications. These electrodes, designed to withstand pressure of greater than 10,000 psi, are adapted for use in microfluidic devices that employ electrokinetic or electrophoretic flow. The electrode is composed, generally, of an outer electrically insulating tubular body having a porous ceramic frit material disposed in one end of the outer body. The pores of the porous ceramic material are filled with an ion conductive polymer resin. A conductive material situated on the upper surface of the porous ceramic frit material and, thus isolated from direct contact with the electrolyte, forms a gas diffusion electrode. A metal current collector, in contact with the gas diffusion electrode, provides connection to a voltage source.

VARIABLE-THROW CAM

DOEpatents

Godsil, E.C.; Robinson, E.Y.

1963-07-16

A variable-throw cam comprising inner and outer eccentric sleeves which are adjustably locked together is described. The cam throw is varied by unlocking the inner and outer sleeves, rotating the outer sleeve relative to the inner one until the desired throw is obtained, and locking the sleeves together again. The cam is useful in applications wherein a continuously-variable throw is required, e.g., ram-and-die pressing operations, cyclic fatigue testing of materials, etc. (AEC)

Remote vacuum compaction of compressible hazardous waste

DOEpatents

Coyne, M.J.; Fiscus, G.M.; Sammel, A.G.

1998-10-06

A system is described for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut. 8 figs.

Remote vacuum compaction of compressible hazardous waste

DOEpatents

Coyne, Martin J.; Fiscus, Gregory M.; Sammel, Alfred G.

1998-01-01

A system for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut.

Remote vacuum compaction of compressible hazardous waste

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

Coyne, M.J.; Fiscus, G.M.; Sammel, A.G.

1996-12-31

A system is described for remote vacuum compaction and containment of low-level radioactive or hazardous waste comprising a vacuum source, a sealable first flexible container, and a sealable outer flexible container for receiving one or more first flexible containers. A method for compacting low level radioactive or hazardous waste materials at the point of generation comprising the steps of sealing the waste in a first flexible container, sealing one or more first containers within an outer flexible container, breaching the integrity of the first containers, evacuating the air from the inner and outer containers, and sealing the outer container shut.

A Transposon Screen Identifies Genetic Determinants of Vibrio cholerae Resistance to High-Molecular-Weight Antibiotics

PubMed Central

Delgado, Fernanda; Umans, Benjamin D.; Gerding, Matthew A.; Davis, Brigid M.

2016-01-01

Gram-negative bacteria are notoriously resistant to a variety of high-molecular-weight antibiotics due to the limited permeability of their outer membrane (OM). The basis of OM barrier function and the genetic factors required for its maintenance remain incompletely understood. Here, we employed transposon insertion sequencing to identify genes required for Vibrio cholerae resistance to vancomycin and bacitracin, antibiotics that are thought to be too large to efficiently penetrate the OM. The screen yielded several genes whose protein products are predicted to participate in processes important for OM barrier functions and for biofilm formation. In addition, we identified a novel factor, designated vigA (for vancomycin inhibits growth), that has not previously been characterized or linked to outer membrane function. The vigA open reading frame (ORF) codes for an inner membrane protein, and in its absence, cells became highly sensitive to glycopeptide antibiotics (vancomycin and ramoplanin) and bacitracin but not to other large antibiotics or detergents. In contrast to wild-type (WT) cells, the vigA mutant was stained with fluorescent vancomycin. These observations suggest that VigA specifically prevents the periplasmic accumulation of certain large antibiotics without exerting a general role in the maintenance of OM integrity. We also observed marked interspecies variability in the susceptibilities of Gram-negative pathogens to glycopeptides and bacitracin. Collectively, our findings suggest that the OM barrier is not absolute but rather depends on specific OM-antibiotic interactions. PMID:27216069

Barriers to Implementing Person-Centered Recovery Planning in Public Mental Health Organizations in Texas: Results from Nine Focus Groups.

PubMed

Lodge, Amy C; Kaufman, Laura; Stevens Manser, Stacey

2017-05-01

Despite being an established practice in the disabilities service systems, person-centered planning is a relatively new practice in the behavioral health system. As a result, little is known about the barriers that mental health organizations face in implementing person-centered recovery planning (PCRP). To fill this gap, results are presented from a qualitative analysis of nine focus groups at three public mental health organizations in Texas that have been implementing PCRP for at least 2 years. Findings suggest that organizations experienced 12 distinct barriers to PCRP implementation which were categorized into the Consolidated Framework for Implementation Research domains of intervention characteristics, the outer setting, the inner setting, characteristics of individuals, and the implementation process. Half of these 12 barriers fell within the inner setting domain, suggesting that implementation efforts should be flexible and adaptable to organizational culture and context. One-quarter of the barriers fell into the domain of characteristics of individuals involved in the intervention, which further suggests implementation efforts should assess the impact that both staff and consumers have on implementation success.

Passive environmental temperature control system

DOEpatents

Corliss, John M.; Stickford, George H.

1981-01-01

Passive environmental heating and cooling systems are described, which utilize heat pipes to transmit heat to or from a thermal reservoir. In a solar heating system, a heat pipe is utilized to carry heat from a solar heat absorber plate that receives sunlight, through a thermal insulation barrier, to a heat storage wall, with the outer end of the pipe which is in contact with the solar absorber being lower than the inner end. The inclining of the heat pipe assures that the portion of working fluid, such as Freon, which is in a liquid phase will fall by gravity to the outer end of the pipe, thereby assuring diode action that prevents the reverse transfer of heat from the reservoir to the outside on cool nights. In a cooling system, the outer end of the pipe which connects to a heat dissipator, is higher than the inner end that is coupled to a cold reservoir, to allow heat transfer only out of the reservoir to the heat dissipator, and not in the reverse direction.

The Antibiotic Novobiocin Binds and Activates the ATPase That Powers Lipopolysaccharide Transport.

PubMed

May, Janine M; Owens, Tristan W; Mandler, Michael D; Simpson, Brent W; Lazarus, Michael B; Sherman, David J; Davis, Rebecca M; Okuda, Suguru; Massefski, Walter; Ruiz, Natividad; Kahne, Daniel

2017-12-06

Novobiocin is an orally active antibiotic that inhibits DNA gyrase by binding the ATP-binding site in the ATPase subunit. Although effective against Gram-positive pathogens, novobiocin has limited activity against Gram-negative organisms due to the presence of the lipopolysaccharide-containing outer membrane, which acts as a permeability barrier. Using a novobiocin-sensitive Escherichia coli strain with a leaky outer membrane, we identified a mutant with increased resistance to novobiocin. Unexpectedly, the mutation that increases novobiocin resistance was not found to alter gyrase, but the ATPase that powers lipopolysaccharide (LPS) transport. Co-crystal structures, biochemical, and genetic evidence show novobiocin directly binds this ATPase. Novobiocin does not bind the ATP binding site but rather the interface between the ATPase subunits and the transmembrane subunits of the LPS transporter. This interaction increases the activity of the LPS transporter, which in turn alters the permeability of the outer membrane. We propose that novobiocin will be a useful tool for understanding how ATP hydrolysis is coupled to LPS transport.

Infectious polymorphic toxins delivered by outer membrane exchange discriminate kin in myxobacteria.

PubMed

Vassallo, Christopher N; Cao, Pengbo; Conklin, Austin; Finkelstein, Hayley; Hayes, Christopher S; Wall, Daniel

2017-08-18

Myxobacteria are known for complex social behaviors including outer membrane exchange (OME), in which cells exchange large amounts of outer membrane lipids and proteins upon contact. The TraA cell surface receptor selects OME partners based on a variable domain. However, traA polymorphism alone is not sufficient to precisely discriminate kin. Here, we report a novel family of OME-delivered toxins that promote kin discrimination of OME partners. These SitA lipoprotein toxins are polymorphic and widespread in myxobacteria. Each sitA is associated with a cognate sitI immunity gene, and in some cases a sitB accessory gene. Remarkably, we show that SitA is transferred serially between target cells, allowing the toxins to move cell-to-cell like an infectious agent. Consequently, SitA toxins define strong identity barriers between strains and likely contribute to population structure, maintenance of cooperation, and strain diversification. Moreover, these results highlight the diversity of systems evolved to deliver toxins between bacteria.

The complex that inserts lipopolysaccharide into the bacterial outer membrane forms a two-protein plug-and-barrel.

PubMed

Freinkman, Elizaveta; Chng, Shu-Sin; Kahne, Daniel

2011-02-08

The cell surfaces of Gram-negative bacteria are composed of lipopolysaccharide (LPS). This glycolipid is found exclusively in the outer leaflet of the asymmetric outer membrane (OM), where it forms a barrier to the entry of toxic hydrophobic molecules into the cell. LPS typically contains six fatty acyl chains and up to several hundred sugar residues. It is biosynthesized in the cytosol and must then be transported across two membranes and an aqueous intermembrane space to the cell surface. These processes are required for the viability of most Gram-negative organisms. The integral membrane β-barrel LptD and the lipoprotein LptE form an essential complex in the OM, which is necessary for LPS assembly. It is not known how this complex translocates large, amphipathic LPS molecules across the OM to the outer leaflet. Here, we show that LptE resides within the LptD β-barrel both in vitro and in vivo. LptD/E associate via an extensive interface; in one specific interaction, LptE contacts a predicted extracellular loop of LptD through the lumen of the β-barrel. Disrupting this interaction site compromises the biogenesis of LptD. This unprecedented two-protein plug-and-barrel architecture suggests how LptD/E can insert LPS from the periplasm directly into the outer leaflet of the OM to establish the asymmetry of the bilayer.

Anisotropy of low-energy Galactic cosmic rays in the outer heliosheath

NASA Astrophysics Data System (ADS)

Zhang, M.; Pogorelov, N.

2017-12-01

Since Voyager 1 crossed the heliopause into the local interstellar medium in August 2012, it has been observing nearly unmodulated low-energy Galactic cosmic rays for over 5 years and 18 AU beyond the heliopause. The angular distribution of these cosmic rays is not isotropic, showing a slight depletion at 90-degree pitch-angle to the magnetic field lines. The anisotropy was interrupted episodically by solar disturbances transmitting through the heliopause into the local interstellar medium of outer heliosheath. These observations indicate the heliosphere still affects cosmic rays in the local interstellar medium. The paper presents a theoretical analysis of the particle transport mechanisms responsible for the observed anisotropy. In order to explain the phenomenon, we argue that cosmic rays of near 90-degree pitch angles do not a quick access to the interstellar cosmic-ray source and in the meantime, they experience some loss in the outer heliosheath. Magnetic field barriers on the both sides of the observer may reduce the access to cosmic ray source, but it still requires that pitch scattering of these particles is very weak in the magnetic field of the outer heliosheath. A possible particle loss mechanism is diffusion into the heliospheric magnetic field where they get modulated by the solar wind plasma. Our model simulation will put constraints on the rates of particle scattering and cross-field diffusion in the interstellar magnetic field of the outer heliosheath.

75 FR 18882 - Certain Footwear: Recommendations For Modifying the Harmonized Tariff Schedule of the United States

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-13

... featuring outer soles of rubber or plastic to which a layer of textile material has been added. DATES: May... the HTSUS relating to certain footwear featuring outer soles of rubber or plastics to which a layer of...

Heat exchanger efficiently operable alternatively as evaporator or condenser

DOEpatents

Ecker, Amir L.

1981-01-01

A heat exchanger adapted for efficient operation alternatively as evaporator or condenser and characterized by flexible outer tube having a plurality of inner conduits and check valves sealingly disposed within the outer tube and connected with respective inlet and outlet master flow conduits and configured so as to define a parallel flow path for a first fluid such as a refrigerant when flowed in one direction and to define a serpentine and series flow path for the first fluid when flowed in the opposite direction. The flexible outer tube has a heat exchange fluid, such as water, flowed therethrough by way of suitable inlet and outlet connections. The inner conduits and check valves form a package that is twistable so as to define a spiral annular flow path within the flexible outer tube for the heat exchange fluid. The inner conduits have thin walls of highly efficient heat transfer material for transferring heat between the first and second fluids. Also disclosed are specific materials and configurations.

Method of synthesizing small-diameter carbon nanotubes with electron field emission properties

NASA Technical Reports Server (NTRS)

Liu, Jie (Inventor); Du, Chunsheng (Inventor); Qian, Cheng (Inventor); Gao, Bo (Inventor); Qiu, Qi (Inventor); Zhou, Otto Z. (Inventor)

2009-01-01

Carbon nanotube material having an outer diameter less than 10 nm and a number of walls less than ten are disclosed. Also disclosed are an electron field emission device including a substrate, an optionally layer of adhesion-promoting layer, and a layer of electron field emission material. The electron field emission material includes a carbon nanotube having a number of concentric graphene shells per tube of from two to ten, an outer diameter from 2 to 8 nm, and a nanotube length greater than 0.1 microns. One method to fabricate carbon nanotubes includes the steps of (a) producing a catalyst containing Fe and Mo supported on MgO powder, (b) using a mixture of hydrogen and carbon containing gas as precursors, and (c) heating the catalyst to a temperature above 950.degree. C. to produce a carbon nanotube. Another method of fabricating an electron field emission cathode includes the steps of (a) synthesizing electron field emission materials containing carbon nanotubes with a number of concentric graphene shells per tube from two to ten, an outer diameter of from 2 to 8 nm, and a length greater than 0.1 microns, (b) dispersing the electron field emission material in a suitable solvent, (c) depositing the electron field emission materials onto a substrate, and (d) annealing the substrate.

Long-lived thermal control materials for high temperature and deep space applications

NASA Technical Reports Server (NTRS)

Whitt, Robin; O'Donnell, Tim

1988-01-01

Considerable effort has been put into developing thermal-control materials for the Galileo space-craft. This paper presents a summary of these findings to date with emphasis on requirements, testing and results for the post-Challenger Galileo mission. Polyimide film (Kapton), due to its inherent stability in vacuum, UV, and radiation environments, combined with good mechanical properties over a large temperature range, has been the preferred substrate for spacecraft thermal control materials. Composite outer layers, using Kapton substrates, can be fabricated to meet the requirements of severe space environments. Included in the processing of Kapton-based composite outer layers can be the deposition of metal oxide, metallic and/or polymeric thin-film coatings to provide desirable electrical, optical and thermo-optical properties. In addition, reinforcement of Kapton substrates with fabrics and films is done to improve mechanical properties. Also these substrates can be filled with varying amounts of carbon to achieve particular electrical properties. The investigation and material development reported on here has led to improved thermo-gravimetric stability, surface conductivity, RF transparency, radiation and UV stability, flammability and handle-ability of outer layer thermal control materials for deep space and near-sun spacecraft. Designing, testing, and qualifying composite thermal-control film materials to meet the requirements of the Galileo spacecraft is the scope of this paper.

Double copper sheath multiconductor instrumentation cable is durable and easily installed in high thermal or nuclear radiation area

NASA Technical Reports Server (NTRS)

Mc Crae, A. W., Jr.

1967-01-01

Multiconductor instrumentation cable in which the conducting wires are routed through two concentric copper tube sheaths, employing a compressed insulator between the conductors and between the inner and outer sheaths, is durable and easily installed in high thermal or nuclear radiation area. The double sheath is a barrier against moisture, abrasion, and vibration.

Snapshot recordings provide a first description of the acoustic signatures of deeper habitats adjacent to coral reefs of Moorea.

PubMed

Bertucci, Frédéric; Parmentier, Eric; Berthe, Cécile; Besson, Marc; Hawkins, Anthony D; Aubin, Thierry; Lecchini, David

2017-01-01

Acoustic recording has been recognized as a valuable tool for non-intrusive monitoring of the marine environment, complementing traditional visual surveys. Acoustic surveys conducted on coral ecosystems have so far been restricted to barrier reefs and to shallow depths (10-30 m). Since they may provide refuge for coral reef organisms, the monitoring of outer reef slopes and describing of the soundscapes of deeper environment could provide insights into the characteristics of different biotopes of coral ecosystems. In this study, the acoustic features of four different habitats, with different topographies and substrates, located at different depths from 10 to 100 m, were recorded during day-time on the outer reef slope of the north Coast of Moorea Island (French Polynesia). Barrier reefs appeared to be the noisiest habitats whereas the average sound levels at other habitats decreased with their distance from the reef and with increasing depth. However, sound levels were higher than expected by propagation models, supporting that these habitats possess their own sound sources. While reef sounds are known to attract marine larvae, sounds from deeper habitats may then also have a non-negligible attractive potential, coming into play before the reef itself.

LiH thermal energy storage device

DOEpatents

Olszewski, M.; Morris, D.G.

1994-06-28

A thermal energy storage device for use in a pulsed power supply to store waste heat produced in a high-power burst operation utilizes lithium hydride as the phase change thermal energy storage material. The device includes an outer container encapsulating the lithium hydride and an inner container supporting a hydrogen sorbing sponge material such as activated carbon. The inner container is in communication with the interior of the outer container to receive hydrogen dissociated from the lithium hydride at elevated temperatures. 5 figures.

Dark matter in the outer solar system

NASA Technical Reports Server (NTRS)

Owen, T.; Cruikshank, D.; De Bergh, C.; Geballe, T.

1994-01-01

There are now a large number of small bodies in the outer solar system that are known to be covered with dark material. Attempts to identify that material have been thwarted by the absence of discrete absorption features in the reflection spectra of these planetesimals. An absorption at 2.2 micrometers that appeared to be present in several objects has not been confirmed by new observations. Three absorptions in the spectrum of the unusually red planetesimal 5145 Pholus are well-established, but their identity remains a mystery.

Thermal insulating barrier and neutron shield providing integrated protection for a nuclear reactor vessel

DOEpatents

Schreiber, R.B.; Fero, A.H.; Sejvar, J.

1997-12-16

The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel to form a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive valving also includes bistable vents at the upper end of the thermal insulating barrier for releasing steam. A removable, modular neutron shield extending around the upper end of the reactor cavity below the nozzles forms with the upwardly and outwardly tapered transition on the outer surface of the reactor vessel, a labyrinthine channel which reduces neutron streaming while providing a passage for the escape of steam during a severe accident, and for the cooling air which is circulated along the reactor cavity walls outside the thermal insulating barrier during normal operation of the reactor. 8 figs.

Thermal insulating barrier and neutron shield providing integrated protection for a nuclear reactor vessel

DOEpatents

Schreiber, Roger B.; Fero, Arnold H.; Sejvar, James

1997-01-01

The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel to form a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive valving also includes bistable vents at the upper end of the thermal insulating barrier for releasing steam. A removable, modular neutron shield extending around the upper end of the reactor cavity below the nozzles forms with the upwardly and outwardly tapered transition on the outer surface of the reactor vessel, a labyrinthine channel which reduces neutron streaming while providing a passage for the escape of steam during a severe accident, and for the cooling air which is circulated along the reactor cavity walls outside the thermal insulating barrier during normal operation of the reactor.

Electrochemical cell design

DOEpatents

Arntzen, John D.

1978-01-01

An electrochemical cell includes two outer electrodes and a central electrode of opposite polarity, all nested within a housing having two symmetrical halves which together form an offset configuration. The outer electrodes are nested within raised portions within the side walls of each housing half while the central electrode sealingly engages the perimetric margins of the side-wall internal surfaces. Suitable interelectrode separators and electrical insulating material electrically isolate the central electrode from the housing and the outer electrodes. The outer electrodes are electrically connected to the internal surfaces of the cell housing to provide current collection. The nested structure minimizes void volume that would otherwise be filled with gas or heavy electrolyte and also provides perimetric edge surfaces for sealing and supporting at the outer margins of frangible interelectrode separator layers.

Evaluation of vegetables in Tsukuba for contamination with radioactive materials from the accident at Fukushima Daiichi nuclear power plant.

PubMed

Isobe, Tomonori; Mori, Yutaro; Takada, Kenta; Sato, Eisuke; Takahashi, Hideki; Sekiguchi, Takao; Yoshimura, Yousuke; Sakurai, Hideyuki; Sakae, Takeji

2013-10-01

A large amount of radioactive material was released into the atmosphere after the accident of the Fukushima Daiichi Nuclear Power Plant following the Tohoku earthquake on 11 March 2011, and traces of these materials were detected in Tsukuba. Because radioactive materials can adhere to vegetables, the authors made a qualitative evaluation of vegetables in Tsukuba, estimated internal exposure dose based on quantitative measurement results, and investigated several decontamination methods. Qualitative analysis of vegetable contamination was done by autoradiography. Quantitative analysis was done using a high-purity germanium detector. To assess decontamination, two methods were tested: one with running water and the other with boiling water. In addition, boiled soup stock was measured. In the qualitative evaluation by autoradiography, radioactive materials were not uniformly distributed but adhered to vegetables in clumps and hot spots. In the quantitative evaluation to measure contamination of outer and inner leaves of sanchu lettuce, it was observed that the concentration of I was 8,031.35 ± 764.79 Bq kg in the outer leaves and 115.28 ± 20.63 Bq kg in the inner leaves. In addition, the concentration of Cs was 1,371.93 ± 366.45 Bq kg in the outer leaves and 9.68 ± 15.03 Bq kg in the inner leaves. This suggests that one can greatly reduce internal exposure dose by removing the outer leaves if one has to eat vegetables just after a nuclear accident. In the decontamination assessment, a decontamination efficiency of up to 70% was achieved by boiling vegetables for 20 min.

Power recovery system for coal liquefaction process

DOEpatents

Horton, J.R.; Eissenberg, D.M.

A flow work exchanger for use in feeding a reactant material to a high-pressure reactor vessel comprises an outer shell, an inner shell concentrically disposed within said outer shell, means for conducting said reactant into the lower end of said lower shell and thence to said reactor vessel, and means for conducting a hotter product effluent from said reactor vessel into the upper end of said inner shell and out of the annulus between said inner and outer shells.

Power recovery system for coal liquefaction process

DOEpatents

Horton, Joel R.; Eissenberg, David M.

1985-01-01

A flow work exchanger for use in feeding a reactant material to a high-pressure reactor vessel comprises an outer shell, an inner shell concentrically disposed within said outer shell, means for conducting said reactant into the lower end of said lower shell and then to said reactor vessel, and means for conducting a hotter product effluent from said reactor vessel into the upper end of said inner shell and out of the annulus between said inner and outer shells.

A preliminary study of aquaporin 1 immunolocalization in chronic subdural hematoma membranes.

PubMed

Basaldella, Luca; Perin, Alessandro; Orvieto, Enrico; Marton, Elisabetta; Itskevich, David; Dei Tos, Angelo Paolo; Longatti, Pierluigi

2010-07-01

Aquaporin 1 (AQP1) is a molecular water channel expressed in many anatomical locations, particularly in epithelial barriers specialized in water transport. The aim of this study was to investigate AQP1 expression in chronic subdural hematoma (CSDH) membranes. In this preliminary study, 11 patients with CSDH underwent burr hole craniectomy and drainage. Membrane specimens were stained with a monoclonal antibody targeting AQP1 for immunohistochemical analysis. The endothelial cells of the sinusoid capillaries of the outer membranes exhibited an elevated immunoreactivity to AQP1 antibody compared to the staining intensity of specimens from the inner membrane and normal dura. These findings suggest that the outer membrane might be the source of the increased fluid accumulation responsible for chronic hematoma enlargement.

Suburban noise control with plant materials and solid barriers

Treesearch

David I. Cook; David F. Van Haverbeke

1977-01-01

Studies were conducted in suburban settings with specially designed noise screens consisting of combinations of plant materials and solid barriers. The amount of reduction in sound level due to the presence of the plant materials and barriers is reported. Observations and conclusions for the measured phenomena are offered, as well as tentative recommendations for the...

Scintillator reflective layer coextrusion

DOEpatents

Yun, Jae-Chul; Para, Adam

2001-01-01

A polymeric scintillator has a reflective layer adhered to the exterior surface thereof. The reflective layer comprises a reflective pigment and an adhesive binder. The adhesive binder includes polymeric material from which the scintillator is formed. A method of forming the polymeric scintillator having a reflective layer adhered to the exterior surface thereof is also provided. The method includes the steps of (a) extruding an inner core member from a first amount of polymeric scintillator material, and (b) coextruding an outer reflective layer on the exterior surface of the inner core member. The outer reflective layer comprises a reflective pigment and a second amount of the polymeric scintillator material.

Method of making a sodium sulfur battery

DOEpatents

Elkins, Perry E.

1981-01-01

A method of making a portion of a sodium sulfur battery is disclosed. The battery portion made is a portion of the container which defines the volume for the cathodic reactant materials which are sulfur and sodium polysulfide materials. The container portion is defined by an outer metal casing with a graphite liner contained therein, the graphite liner having a coating on its internal diameter for sealing off the porosity thereof. The steel outer container and graphite pipe are united by a method which insures that at the operating temperature of the battery, relatively low electrical resistance exists between the two materials because they are in intimate contact with one another.

FUEL ELEMENT FOR NUCLEAR REACTORS

DOEpatents

Bassett, C.H.

1961-07-11

Nuclear reactor fuel elements of the type in which the flssionsble material is in ceramic form, such as uranium dioxide, are described. The fuel element is comprised of elongated inner and outer concentric spaced tubular members providing an annular space therebetween for receiving the fissionable material, the annular space being closed at both ends and the inner tube being open at both ends. The fuel is in the form of compressed pellets of ceramic fissionsble material having the configuration of split bushings formed with wedge surfaces and arranged in seriated inner and outer concentric groups which are urged against the respective tubes in response to relative axial movement of the pellets in the direction toward each other. The pairs of pellets are axially urged together by a resilient means also enclosed within the annulus. This arrangement-permits relative axial displacement of the pellets during use dial stresses on the inner and outer tube members and yet maintains the fuel pellets in good thermal conductive relationship therewith.

Intermediate-band photosensitive device with quantum dots embedded in energy fence barrier

DOEpatents

Forrest, Stephen R.; Wei, Guodan

2010-07-06

A plurality of layers of a first semiconductor material and a plurality of dots-in-a-fence barriers disposed in a stack between a first electrode and a second electrode. Each dots-in-a-fence barrier consists essentially of a plurality of quantum dots of a second semiconductor material embedded between and in direct contact with two layers of a third semiconductor material. Wave functions of the quantum dots overlap as at least one intermediate band. The layers of the third semiconductor material are arranged as tunneling barriers to require a first electron and/or a first hole in a layer of the first material to perform quantum mechanical tunneling to reach the second material within a respective quantum dot, and to require a second electron and/or a second hole in a layer of the first semiconductor material to perform quantum mechanical tunneling to reach another layer of the first semiconductor material.

The Evaluation and Validation of New Creep Barrier Films for Prevention of Oil Loss by Migration

NASA Astrophysics Data System (ADS)

Hampson, Matthew R.; Wardzinski, Ben

2015-09-01

Creep barrier films are used to prevent loss of oil by surface migration. This paper gives an overview of studies to select, characterise and validate creep barrier materials for spacecraft mechanisms [1].One of the more commonly used materials, Fluorad FC- 725, is no longer manufactured, and there is a need to identify a replacement.A survey of available materials was carried out, and after a series of trial tests, three materials were down- selected for the validation exercise: two new materials - 3M Novec 2708 and Dr Tillwich E2 Concentrate - alongside the obsolete Fluorad FC-725 used as a baseline.A validation procedure is defined, which may be applied to other new creep barrier materials in future. Testing confirmed that either of the new materials would be suitable for use.

Organic Materials Ionizing Radiation Susceptibility for the Outer Planet/Solar Probe Radioisotope Power Source

NASA Technical Reports Server (NTRS)

Golliher, Eric L.; Pepper, Stephen V.

2001-01-01

The Department of Energy is considering the current Stirling Technology Corporation 55 We Stirling Technology Demonstration Convertor as a baseline option for an advanced radioisotope power source for the Outer Planets/Solar Probe project of Jet Propulsion Laboratory and other missions. However, since the Technology Demonstration Convertor contains organic materials chosen without any special consideration of flight readiness, and without any consideration of the extremely high radiation environment of Europa, a preliminary investigation was performed to address the radiation susceptibility of the current organic materials used in the Technology Demonstration Convertor. This report documents the results of the investigation. The results of the investigation show that candidate replacement materials have been identified to be acceptable in the harsh Europa radiation environment.

Splaying of aliphatic tails plays a central role in barrier crossing during liposome fusion.

PubMed

Mirjanian, Dina; Dickey, Allison N; Hoh, Jan H; Woolf, Thomas B; Stevens, Mark J

2010-09-02

The fusion between two lipid bilayers involves crossing a complicated energy landscape. The limiting barrier in the process appears to be between two closely opposed bilayers and the intermediate state where the outer leaflets are fused. We have performed molecular dynamics simulations to characterize the free energy barrier for the fusion of two liposomes and to examine the molecular details of barrier crossing. To capture the slow dynamics of fusion, a model using coarse-grained representations of lipids was used. The fusion between pairs of liposomes was simulated for four systems: DPPC, DOPC, a 3:1 mixture of DPPC/DPPE, and an asymmetric lipid tail system in which one tail of DPPC was reduced to half the length (ASTail). The weighted histogram method was used to compute the free energy as a function of separation distance. The relative barrier heights for these systems was found to be ASTail > DPPC > DPPC/DPPE > DOPC, in agreement with experimental observations. Further, the free energy curves for all four can be overlaid on a single curve by plotting the free energy versus the surface separation (differing only in the point of fusion). These simulations also confirm that the two main contributions to the free energy barrier are the removal of water between the vesicles and the deformation of the vesicle. The most prominent molecular detail of barrier crossing in all cases examined was the splaying of lipid tails, where initially a single splayed lipid formed a bridge between the two outer leaflets that promotes additional lipid mixing between the vesicles and eventually leads to fusion. The tail splay appears to be closely connected to the energetics of the process. For example, the high barrier for the ASTail is the result of a smaller distance between terminal methyl groups in the splayed molecule. The shortening of this distance requires the liposomes to be closer together, which significantly increases the cost of water removal and bilayer deformation. Before tail splay can initiate fusion, contact must occur between a tail end and the external water. In isolated vesicles, the contact fraction is correlated to the fusogenicity difference between DPPC and DOPC. Moreover, for planar bilayers, the contact fraction is much lower for DPPC, which is consistent with its lack of fusion in giant vesicles. The simulation results show the key roles of lipid tail dynamics in governing the fusion energy landscape.

In-situ formation of multiphase electron beam physical vapor deposited barrier coatings for turbine components

DOEpatents

Subramanian, Ramesh

2001-01-01

A turbine component (10), such as a turbine blade, is provided which is made of a metal alloy (22) and a base columnar thermal barrier coating (20) on the alloy surface, where a heat resistant ceramic oxide sheath material (32' or 34') covers the columns (28), and the sheath material is the reaction product of a precursor ceramic oxide sheath material and the base thermal barrier coating material.

NEUTRON COUNTER

DOEpatents

Curtis, C.D.; Carlson, R.L.; Tubinis, M.P.

1958-07-29

An ionization chamber instrument is described for cylindrical electrodes with an ionizing gag filling the channber. The inner electrode is held in place by a hermetic insulating seal at one end of the outer electrode, the other end of the outer electrode being closed by a gas filling tube. The outer surface of the inner electrode is coated with an active material which is responsive to neutron bombardment, such as uranium235 or boron-10, to produce ionizing radiations in the gas. The transverse cross sectional area of the inner electrode is small in relation to that of the channber whereby substantially all of the radiations are directed toward the outer electrode.

9 CFR 108.10 - Outer premises and stables.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Outer premises and stables. 108.10 Section 108.10 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF... premises of an establishment, of any material in which flies or other vermin may breed is forbidden...

Avian inhalation exposure chamber

DOEpatents

Briant, James K.; Driver, Crystal J.

1992-01-01

An exposure system for delivering gaseous material ranging in particle size from 0.4 micrometers to 20.0 micrometers uniformly to the heads of experimental animals, primarily birds. The system includes a vertical outer cylinder and a central chimney with animal holding bottles connected to exposure ports on the vertical outer cylinder.

49 CFR Appendix D to Part 178 - Thermal Resistance Test

Code of Federal Regulations, 2013 CFR

2013-10-01

... large enough in size to fully house the test outer package without clearance problems. The test oven....3Instrumentation. A calibrated recording device or a computerized data acquisition system with an appropriate range... Configuration. Each outer package material type and design must be tested, including any features such as...

49 CFR Appendix D to Part 178 - Thermal Resistance Test

Code of Federal Regulations, 2014 CFR

2014-10-01

... large enough in size to fully house the test outer package without clearance problems. The test oven....3Instrumentation. A calibrated recording device or a computerized data acquisition system with an appropriate range... Configuration. Each outer package material type and design must be tested, including any features such as...

49 CFR Appendix D to Part 178 - Thermal Resistance Test

Code of Federal Regulations, 2011 CFR

2011-10-01

... large enough in size to fully house the test outer package without clearance problems. The test oven....3Instrumentation. A calibrated recording device or a computerized data acquisition system with an appropriate range... Configuration. Each outer package material type and design must be tested, including any features such as...

49 CFR Appendix D to Part 178 - Thermal Resistance Test

Code of Federal Regulations, 2012 CFR

2012-10-01

... large enough in size to fully house the test outer package without clearance problems. The test oven....3Instrumentation. A calibrated recording device or a computerized data acquisition system with an appropriate range... Configuration. Each outer package material type and design must be tested, including any features such as...

Characterization of a major 31-kilodalton peptidoglycan-bound protein of Legionella pneumophila

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

Butler, C.A.; Hoffman, P.S.

1990-05-01

A 31-kilodalton (kDa) protein was solubilized from the peptidoglycan (PG) fraction of Legionella pneumophila after treatment with either N-acetylmuramidase from the fungus Chalaropsis sp. or with mutanolysin from Streptomyces globisporus. The protein exhibited a ladderlike banding pattern by autoradiography when radiolabeled ((35S)cysteine or (35S)methionine) PG material was extensively treated with hen lysozyme. The banding patterns ranging between 31 and 45 kDa and between 55 and 60 kDa resolved as a single 31-kDa protein when the material was subsequently treated with N-acetylmuramidase. Analysis of the purified 31-kDa protein for diaminopimelic acid by gas chromatography revealed 1 mol of diaminopimelic acid permore » mol of protein. When outer membrane PG material containing the major outer membrane porin protein was treated with N-acetylmuramidase or mutanolysin, both the 28.5-kDa major outer membrane protein and the 31-kDa protein were solubilized from the PG material under reducing conditions. In the absence of 2-mercaptoethanol, a high-molecular-mass complex (100 kDa) was resolved. The results of this study indicate that a 31-kDa PG-bound protein is a major component of the cell wall of L. pneumophila whose function may be to anchor the major outer membrane protein to PG. Finally, a survey of other Legionella species and other serogroups of L. pneumophila suggested that PG-bound proteins may be a common feature of this genus.« less

Influence of niacinamide containing formulations on the molecular and biophysical properties of the stratum corneum.

PubMed

Mohammed, D; Crowther, J M; Matts, P J; Hadgraft, J; Lane, M E

2013-01-30

Niacinamide-containing moisturisers are known be efficacious in alleviating dry skin conditions and improving stratum corneum (SC) barrier function. However, the mechanisms of action of niacinamide at the molecular level in the SC are still not well understood. Previously, we have reported the development of novel methods to probe SC barrier properties in vivo. The aim of the present study was to characterise changes in Trans Epidermal Water Loss (TEWL), corneocyte surface area and maturity, selected protease activities and SC thickness after repeated application of a simple vehicle containing niacinamide. A commercial formulation was also included as a reference. The left and right mid-volar forearms of 20 healthy volunteers were used as study sites, to which topical formulations were applied twice daily for 28 days. After successive tape-stripping, corneocyte maturity and surface area were assessed. In addition, activity of the desquamatory kallikrein (KLK) protease enzymes KLK5 and KLK7, and tryptase and plasmin (implicated in inflammatory process) were measured using a fluorogenic probe assay. The amount of protein removed and TEWL were also recorded. SC thickness before and after treatment was determined using Confocal Raman Spectroscopy (CRS). Overall (i) corneocyte maturity and surface area decreased with increasing number of tape strips, (ii) activity of both the desquamatory and inflammatory enzymes was highest in the outer layers of the SC and decreased with depth (iii) TEWL increased as more SC layers were removed. Furthermore, areas treated with formulations containing niacinamide were significantly different to pre-treatment baseline and untreated/vehicle-control treated sites, with larger and more mature corneocytes, decreased inflammatory activity, decreased TEWL and increased SC thickness. These data (a) confirm the utility of measures and metrics developed previously for the non-invasive assay of SC barrier function, (b) present an holistic picture of a SC compartment managing barrier function through dynamic optimisation of pathlength and quality of building materials used, and (c) shed new light on niacinamide as a topical formulation adjunct with unique SC barrier-augmentation properties. Copyright © 2012 Elsevier B.V. All rights reserved.

Photovoltaic and thermophotovoltaic devices with quantum barriers

DOEpatents

Wernsman, Bernard R [Jefferson Hills, PA

2007-04-10

A photovoltaic or thermophotovoltaic device includes a diode formed by p-type material and n-type material joined at a p-n junction and including a depletion region adjacent to said p-n junction, and a quantum barrier disposed near or in the depletion region of the p-n junction so as to decrease device reverse saturation current density while maintaining device short circuit current density. In one embodiment, the quantum barrier is disposed on the n-type material side of the p-n junction and decreases the reverse saturation current density due to electrons while in another, the barrier is disposed on the p-type material side of the p-n junction and decreases the reverse saturation current density due to holes. In another embodiment, both types of quantum barriers are used.

Comparison and testing of various noise wall materials.

DOT National Transportation Integrated Search

2014-06-01

Noise barriers are a necessary structure along the highway to protect the local residents from excessive : road noise. There are many different materials from which noise barriers can be constructed. As of 2004, the : most widely used noise barrier m...

Large size self-assembled quantum rings: quantum size effect and modulation on the surface diffusion.

PubMed

Tong, Cunzhu; Yoon, Soon Fatt; Wang, Lijun

2012-09-24

We demonstrate experimentally the submicron size self-assembled (SA) GaAs quantum rings (QRs) by quantum size effect (QSE). An ultrathin In0.1 Ga0.9As layer with different thickness is deposited on the GaAs to modulate the surface nucleus diffusion barrier, and then the SA QRs are grown. It is found that the density of QRs is affected significantly by the thickness of inserted In0.1 Ga0.9As, and the diffusion barrier modulation reflects mainly on the first five monolayer . The physical mechanism behind is discussed. The further analysis shows that about 160 meV decrease in diffusion barrier can be achieved, which allows the SA QRs with density of as low as one QR per 6 μm2. Finally, the QRs with diameters of 438 nm and outer diameters of 736 nm are fabricated using QSE.

An Electrostatic-Barrier-Forming Window that Captures Airborne Pollen Grains to Prevent Pollinosis

PubMed Central

Takikawa, Yoshihiro; Matsuda, Yoshinori; Nonomura, Teruo; Kakutani, Koji; Kusakari, Shin-Ichi; Toyoda, Hideyoshi

2017-01-01

An electrostatic-barrier-forming window (EBW) was devised to capture airborne pollen, which can cause allergic pollinosis. The EBW consisted of three layers of insulated conductor wires (ICWs) and two voltage generators that supplied negative charges to the two outer ICW layers and a positive charge to the middle ICW layer. The ICWs generated an attractive force that captured pollen of the Japanese cedar, Cryptomeria japonica, from air blown through the EBW. The attractive force was directly proportional to the applied voltage. At ≥3.5 kV, the EBW exerted sufficient force to capture all pollen carried at an air flow of 3 m/s, and pollen-free air passed through the EBW. The findings demonstrated that the electrostatic barrier that formed inside the EBW was very effective at capturing airborne pollen; thus, it could allow a home to remain pollen-free and healthy despite continuous pollen exposure. PMID:28098835

Concerted regulation of retinal pigment epithelium basement membrane and barrier function by angiocrine factors.

PubMed

Benedicto, Ignacio; Lehmann, Guillermo L; Ginsberg, Michael; Nolan, Daniel J; Bareja, Rohan; Elemento, Olivier; Salfati, Zelda; Alam, Nazia M; Prusky, Glen T; Llanos, Pierre; Rabbany, Sina Y; Maminishkis, Arvydas; Miller, Sheldon S; Rafii, Shahin; Rodriguez-Boulan, Enrique

2017-05-19

The outer blood-retina barrier is established through the coordinated terminal maturation of the retinal pigment epithelium (RPE), fenestrated choroid endothelial cells (ECs) and Bruch's membrane, a highly organized basement membrane that lies between both cell types. Here we study the contribution of choroid ECs to this process by comparing their gene expression profile before (P5) and after (P30) the critical postnatal period when mice acquire mature visual function. Transcriptome analyses show that expression of extracellular matrix-related genes changes dramatically over this period. Co-culture experiments support the existence of a novel regulatory pathway: ECs secrete factors that remodel RPE basement membrane, and integrin receptors sense these changes triggering Rho GTPase signals that modulate RPE tight junctions and enhance RPE barrier function. We anticipate our results will spawn a search for additional roles of choroid ECs in RPE physiology and disease.

Concerted regulation of retinal pigment epithelium basement membrane and barrier function by angiocrine factors

PubMed Central

Benedicto, Ignacio; Lehmann, Guillermo L.; Ginsberg, Michael; Nolan, Daniel J.; Bareja, Rohan; Elemento, Olivier; Salfati, Zelda; Alam, Nazia M.; Prusky, Glen T.; Llanos, Pierre; Rabbany, Sina Y.; Maminishkis, Arvydas; Miller, Sheldon S.; Rafii, Shahin; Rodriguez-Boulan, Enrique

2017-01-01

The outer blood-retina barrier is established through the coordinated terminal maturation of the retinal pigment epithelium (RPE), fenestrated choroid endothelial cells (ECs) and Bruch's membrane, a highly organized basement membrane that lies between both cell types. Here we study the contribution of choroid ECs to this process by comparing their gene expression profile before (P5) and after (P30) the critical postnatal period when mice acquire mature visual function. Transcriptome analyses show that expression of extracellular matrix-related genes changes dramatically over this period. Co-culture experiments support the existence of a novel regulatory pathway: ECs secrete factors that remodel RPE basement membrane, and integrin receptors sense these changes triggering Rho GTPase signals that modulate RPE tight junctions and enhance RPE barrier function. We anticipate our results will spawn a search for additional roles of choroid ECs in RPE physiology and disease. PMID:28524846

An Electrostatic-Barrier-Forming Window that Captures Airborne Pollen Grains to Prevent Pollinosis.

PubMed

Takikawa, Yoshihiro; Matsuda, Yoshinori; Nonomura, Teruo; Kakutani, Koji; Kusakari, Shin-Ichi; Toyoda, Hideyoshi

2017-01-15

An electrostatic-barrier-forming window (EBW) was devised to capture airborne pollen, which can cause allergic pollinosis. The EBW consisted of three layers of insulated conductor wires (ICWs) and two voltage generators that supplied negative charges to the two outer ICW layers and a positive charge to the middle ICW layer. The ICWs generated an attractive force that captured pollen of the Japanese cedar, Cryptomeria japonica , from air blown through the EBW. The attractive force was directly proportional to the applied voltage. At ≥3.5 kV, the EBW exerted sufficient force to capture all pollen carried at an air flow of 3 m/s, and pollen-free air passed through the EBW. The findings demonstrated that the electrostatic barrier that formed inside the EBW was very effective at capturing airborne pollen; thus, it could allow a home to remain pollen-free and healthy despite continuous pollen exposure.

Nuclear reactor vessel fuel thermal insulating barrier

DOEpatents

Keegan, C. Patrick; Scobel, James H.; Wright, Richard F.

2013-03-19

The reactor vessel of a nuclear reactor installation which is suspended from the cold leg nozzles in a reactor cavity is provided with a lower thermal insulating barrier spaced from the reactor vessel that has a hemispherical lower section that increases in volume from the center line of the reactor to the outer extent of the diameter of the thermal insulating barrier and smoothly transitions up the side walls of the vessel. The space between the thermal insulating harrier and the reactor vessel forms a chamber which can be flooded with cooling water through passive valving to directly cool the reactor vessel in the event of a severe accident. The passive inlet valve for the cooling water includes a buoyant door that is normally maintained sealed under its own weight and floats open when the cavity is Hooded. Passively opening steam vents are also provided.

Shaft/shaft-seal interface characteristics of a multiple disk centrifugal blood pump.

PubMed

Manning, K B; Miller, G E

1999-06-01

A multiple disk centrifugal pump (MDCP) is under investigation as a potential left ventricular assist device. As is the case with most shaft driven pumps, leakage problems around the shaft/shaft seal interface are of major interest. If leakage were to occur during or after implantation, potential events such as blood loss, clotting, blood damage, and/or infections might result in adverse effects for the patient. Because these effects could be quite disastrous, potential shaft and shaft seal materials have been investigated to determine the most appropriate course to limit these effects. Teflon and nylon shaft seals were analyzed as potential candidates along with a stainless steel shaft and a Melonite coated shaft. The materials and shafts were evaluated under various time durations (15, 30, 45, and 60 min), motor speeds (800, 1,000, 1,200, and 1,400 rpm), and outer diameters (1/2 and 3/4 inches). The motor speed and geometrical configurations were typical for the MDCP under normal physiologic conditions. An air and water study was conducted to analyze the inner diameter wear, the inner temperature values, and the outer temperature values. Statistical comparisons were computed for the shaft seal materials, the shafts, and the outer diameters along with the inner and outer temperatures. The conclusions made from the results indicate that both the tested shaft seal materials and shaft materials are not ideal candidates to be used for the MDCP. Teflon experienced a significant amount of wear in air and water studies. Nylon did experience little wear, but heat generation was an evident problem. A water study on nylon was not conducted because of its molecular structure.

Ice detector

NASA Technical Reports Server (NTRS)

Weinstein, Leonard M. (Inventor)

1988-01-01

An ice detector is provided for the determination of the thickness of ice on the outer surface on an object (e.g., aircraft) independently of temperature or the composition of the ice. First capacitive gauge, second capacitive gauge, and temperature gauge are embedded in embedding material located within a hollowed out portion of the outer surface. This embedding material is flush with the outer surface to prevent undesirable drag. The first capacitive gauge, second capacitive gauge, and the temperature gauge are respectively connected to first capacitive measuring circuit, second capacitive measuring circuit, and temperature measuring circuit. The geometry of the first and second capacitive gauges is such that the ratio of the voltage outputs of the first and second capacitance measuring circuits is proportional to the thickness of ice, regardless of ice temperature or composition. This ratio is determined by offset and dividing circuit.

Avian inhalation exposure chamber

DOEpatents

Briant, J.K.; Driver, C.J.

1992-05-05

An exposure system is designed for delivering gaseous material ranging in particle size from 0.4 micrometers to 20.0 micrometers uniformly to the heads of experimental animals, primarily birds. The system includes a vertical outer cylinder and a central chimney with animal holding bottles connected to exposure ports on the vertical outer cylinder. 2 figs.

49 CFR Appendix D to Part 178 - Thermal Resistance Test

Code of Federal Regulations, 2010 CFR

2010-10-01

... must be large enough in size to fully house the test outer package without clearance problems. The test....3Instrumentation. A calibrated recording device or a computerized data acquisition system with an appropriate range... Configuration. Each outer package material type and design must be tested, including any features such as...

High-performance, lightweight coaxial cable from carbon nanotube conductors.

PubMed

Jarosz, Paul R; Shaukat, Aalyia; Schauerman, Christopher M; Cress, Cory D; Kladitis, Paul E; Ridgley, Richard D; Landi, Brian J

2012-02-01

Coaxial cables have been constructed with carbon nanotube (CNT) materials serving as both the inner and outer conductors. Treatment of the CNT outer and inner conductors with KAuBr(4) was found to significantly reduce the attenuation of these cables, which demonstrates that chemical agents can be used to improve power transmission through CNT networks at high frequencies (150 kHz-3 GHz). For cables constructed with a KAuBr(4)-treated CNT outer conductor, power attenuation per length approaches parity with cables constructed from metallic conductors at significantly lower weight per length (i.e., 7.1 g/m for CNT designs compared to 38.8 g/m for an RG-58 design). A relationship between the thickness of the CNT outer conductor and the cable attenuation was observed and used to estimate the effective skin depth at high frequency. These results establish reliable, reproducible methods for the construction of coaxial cables from CNT materials that can facilitate further investigation of their performance in high-frequency transmission structures, and highlight a specific opportunity for significant reduction in coaxial cable mass.

Method of making a sodium sulfur battery

DOEpatents

Elkins, P. E.

1981-09-22

A method of making a portion of a sodium sulfur battery is disclosed. The battery portion made is a portion of the container which defines the volume for the cathodic reactant materials which are sulfur and sodium polysulfide materials. The container portion is defined by an outer metal casing with a graphite liner contained therein, the graphite liner having a coating on its internal diameter for sealing off the porosity thereof. The steel outer container and graphite pipe are united by a method which insures that at the operating temperature of the battery, relatively low electrical resistance exists between the two materials because they are in intimate contact with one another. 3 figs.

[Carrier-mediated Transport of Cationic Drugs across the Blood-Tissue Barrier].

PubMed

Kubo, Yoshiyuki

2015-01-01

Studies of neurological dysfunction have revealed the neuroprotective effect of several cationic drugs, suggesting their usefulness in the treatment of neurological diseases. In the brain and retina, blood-tissue barriers such as blood-brain barrier (BBB) and blood-retinal barrier (BRB) are formed to restrict nonspecific solute transport between the circulating blood and neural tissues. Therefore study of cationic drug transport at these barriers is essential to achieve systemic delivery of neuroprotective agents into the neural tissues. In the retina, severe diseases such as diabetic retinopathy and macular degeneration can cause neurological dysfunction that dramatically affects patients' QOL. The BRB is formed by retinal capillary endothelial cells (inner BRB) and retinal pigment epithelial cells (outer BRB). Blood-to-retina transport of cationic drugs was investigated at the inner BRB, which is known to nourish two thirds of the retina. Blood-to-retinal transport of verapamil suggested that the barrier function of the BRB differs from that of the BBB. Moreover, carrier-mediated transport of verapamil and pyrilamine revealed the involvement of novel organic cation transporters at the inner BRB. The identified transport systems for cationic drugs are sensitive to several cationic neuroprotective and anti-angiogenic agents such as clonidine and propranolol, and the involvement of novel transporters was also suggested in their blood-to-retina transport across the inner BRB.

Self-sterilization of bodies during outer planet entry

NASA Technical Reports Server (NTRS)

Hoffman, A. R.; Jaworski, W.; Taylor, D. M.

1974-01-01

A body encountering the atmosphere of an outer planet is subjected to heat loads which could result in high temperature conditions that render terrestrial organisms on or within the body nonviable. To determine whether an irregularly shaped entering body, consisting of several different materials, would be sterilized during inadvertent entry at high velocity, the thermal response of a typical outer planet spacecraft instrument was studied. The results indicate that the Teflon insulated cable and electronic circuit boards may not experience sterilizing temperatures during a Jupiter, Saturn, or Titan entry. Another conclusion of the study is that small plastic particles entering Saturn from outer space have wider survival corridors than do those at Jupiter.

Barriers and facilitators to HPV vaccination in primary care practices: a mixed methods study using the Consolidated Framework for Implementation Research.

PubMed

Garbutt, Jane M; Dodd, Sherry; Walling, Emily; Lee, Amanda A; Kulka, Katharine; Lobb, Rebecca

2018-05-07

In the United States, the effective, safe huma papilloma virus (HPV) vaccine is underused and opportunities to prevent cancer continue to be missed. National guidelines recommend completing the 2-3 dose HPV vaccine series by age 13, well before exposure to the sexually transmitted virus. Accurate characterization of the facilitators and barriers to full implementation of HPV vaccine recommendations in the primary care setting could inform effective implementation strategies. We used the Consolidated Framework for Implementation Research (CFIR) to systematically investigate and characterize factors that influence HPV vaccine use in 10 primary care practices (16 providers) using a concurrent mixed methods design. The CFIR was used to guide collection and analysis of qualitative data collected through in-person semi-structured interviews with the primary care providers. We analyzed HPV vaccine use with data abstracted from medical charts. Constructs that most strongly influenced vaccine use were identified by integrating the qualitative and quantitative data. Of the 72 CFIR constructs assessed, seven strongly distinguished and seven weakly distinguished between providers with higher versus lower HPV vaccine coverage. The majority of strongly distinguishing constructs were facilitators and were related to characteristics of the providers (knowledge and beliefs; self-efficacy; readiness for change), their perception of the intervention (relative advantage of vaccinating younger vs. older adolescents), and their process to deliver the vaccine (executing). Additional weakly distinguishing constructs that were facilitators were from outer setting (peer pressure; financial incentives), inner setting (networks and communications and readiness for implementation) and process (planning; engaging, and reflecting and evaluating). Two strongly distinguishing constructs were barriers to use, one from the intervention (adaptability of the age of initiation) and the other from outer setting (patient needs and resources). Using CFIR to systematically examine the use of this vaccine in independent primary care practices enabled us to identify facilitators and barriers at the provider, interpersonal and practice level that need to be addressed in future efforts to increase vaccine use in such settings. Our findings suggest that implementation strategies that target the provider and help them to address multi-level barriers to HPV vaccine use merit further investigation.

77 FR 22504 - Hazardous Materials; Packages Intended for Transport by Aircraft

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-16

... material to absorb the entire contents of the inner packaging, before being placed in its outer package... combination packaging intended for the air transportation of liquid hazardous materials is capable of..., leakproof receptacle or intermediate packaging containing sufficient absorbent material to absorb the entire...

Liposomes and nanotechnology in drug development: focus on ocular targets

PubMed Central

Honda, Miki; Asai, Tomohiro; Oku, Naoto; Araki, Yoshihiko; Tanaka, Minoru; Ebihara, Nobuyuki

2013-01-01

Poor drug delivery to lesions in patients’ eyes is a major obstacle to the treatment of ocular diseases. The accessibility of these areas to drugs is highly restricted by the presence of barriers, including the corneal barrier, aqueous barrier, and the inner and outer blood–retinal barriers. In particular, the posterior segment is difficult to reach for drugs because of its structural peculiarities. This review discusses various barriers to drug delivery and provides comprehensive information for designing nanoparticle-mediated drug delivery systems for the treatment of ocular diseases. Nanoparticles can be designed to improve penetration, controlled release, and drug targeting. As highlighted in this review, the therapeutic efficacy of drugs in ocular diseases has been reported to be enhanced by the use of nanoparticles such as liposomes, micro/nanospheres, microemulsions, and dendrimers. Our recent data show that intravitreal injection of targeted liposomes encapsulating an angiogenesis inhibitor caused significantly greater suppression of choroidal neovascularization than did the injection of free drug. Recent progress in ocular drug delivery systems research has provided new insights into drug development, and the use of nanoparticles for drug delivery is thus a promising approach for advanced therapy of ocular diseases. PMID:23439842

Review of potential subsurface permeable barrier emplacement and monitoring technologies

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

Riggsbee, W.H.; Treat, R.L.; Stansfield, H.J.

1994-02-01

This report focuses on subsurface permeable barrier technologies potentially applicable to existing waste disposal sites. This report describes candidate subsurface permeable barriers, methods for emplacing these barriers, and methods used to monitor the barrier performance. Two types of subsurface barrier systems are described: those that apply to contamination.in the unsaturated zone, and those that apply to groundwater and to mobile contamination near the groundwater table. These barriers may be emplaced either horizontally or vertically depending on waste and site characteristics. Materials for creating permeable subsurface barriers are emplaced using one of three basic methods: injection, in situ mechanical mixing, ormore » excavation-insertion. Injection is the emplacement of dissolved reagents or colloidal suspensions into the soil at elevated pressures. In situ mechanical mixing is the physical blending of the soil and the barrier material underground. Excavation-insertion is the removal of a soil volume and adding barrier materials to the space created. Major vertical barrier emplacement technologies include trenching-backfilling; slurry trenching; and vertical drilling and injection, including boring (earth augering), cable tool drilling, rotary drilling, sonic drilling, jetting methods, injection-mixing in drilled holes, and deep soil mixing. Major horizontal barrier emplacement technologies include horizontal drilling, microtunneling, compaction boring, horizontal emplacement, longwall mining, hydraulic fracturing, and jetting methods.« less

Efficient gas barrier properties of multi-layer films based on poly(lactic acid) and fish gelatin.

PubMed

Hosseini, Seyed Fakhreddin; Javidi, Zahra; Rezaei, Masoud

2016-11-01

Multi-layer film structures of poly(lactic acid) (PLA) and fish gelatin (FG), prepared using the solvent casting technique, were studied in an effort to produce bio-based films with low oxygen (OP) and water vapor permeability (WVP). The scanning electron microscopy (SEM) images of triple-layer film showed that the outer PLA layers are being closely attached to the inner FG layer to make continuous film. The OP of multi-layer film (5.02cm 3 /m 2 daybar) decreased more than 8-fold compared with that of the PLA film, and the WVP of multi-layer film (0.125gmm/kPah m 2 ) also decreased 11-fold compared with that of the FG film. Lamination with PLA profoundly increased the water resistance of the bare gelatin film. Meanwhile, the tensile strength of the triple-layer film (25±2.13MPa) was greater than that of FG film (7.48±1.70MPa). At the same time, the resulting film maintains high optical clarity. Differential scanning calorimetry (DSC) analysis also revealed that the materials were compatible showing only one T g which decreased with FG deposition. This material exhibits an environmental-friendliness potential and a high versatility in food packaging. Copyright © 2016 Elsevier B.V. All rights reserved.

InP-InxGa1-xAs core-multi-shell nanowire quantum wells with tunable emission in the 1.3-1.55 μm wavelength range.

PubMed

Fonseka, H A; Ameruddin, A S; Caroff, P; Tedeschi, D; De Luca, M; Mura, F; Guo, Y; Lysevych, M; Wang, F; Tan, H H; Polimeni, A; Jagadish, C

2017-09-21

The usability and tunability of the essential InP-InGaAs material combination in nanowire-based quantum wells (QWs) are assessed. The wurtzite phase core-multi-shell InP-InGaAs-InP nanowire QWs are characterised using cross-section transmission electron microscopy and photoluminescence measurements. The InP-InGaAs direct interface is found to be sharp while the InGaAs-InP inverted interface is more diffused, in agreement with their planar counterpart. Bright emission is observed from the single nanowires containing the QWs at room temperature, with no emission from the InP core or outer barrier. The tunability of the QW emission wavelength in the 1.3-1.55 μm communication wavelength range is demonstrated by varying the QW thickness and in the 1.3 μm range by varying the composition. The experiments are supported by simulation of the emission wavelength of the wurtzite phase InP-InGaAs QWs in the thickness range considered. The radial heterostructure is further extended to design multiple QWs with bright emission, therefore establishing the capability of this material system for nanowire based optical devices for communication applications.

Parametric design analysis of a hybrid composite flywheel using a laminated central disc and a filament wound outer ring

NASA Astrophysics Data System (ADS)

Nimmer, R. P.

1980-09-01

A hybrid flywheel design concept based on the use of a laminated central disk with a filament-wound outer ring is analyzed for several different combinations of composite materials. Some of the results of this study are: (1) an optimized E-glass disk with Kevlar-49 outer ring offers the prospect of 30% additional energy density over a laminated disk without a ring; (2) a laminated S2-glass disk is capable of storing more energy per unit mass than an E-glass disk because of its higher tensile strength; and (3) the use of wound graphite outer rings with S2-glass disks leads to substantial reductions in the size of the interference fit while offering still higher energy densities than for a Kevlar-49 outer ring.

Effect of Divalent Cation Removal on the Structure of Gram-Negative Bacterial Outer Membrane Models

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

Clifton, Luke A.; Skoda, Maximilian W. A.; Le Brun, Anton P.

The Gram-negative bacterial outer membrane (GNB-OM) is asymmetric in its lipid composition with a phospholipid-rich inner leaflet and an outer leaflet predominantly composed of lipopolysaccharides (LPS). LPS are polyanionic molecules, with numerous phosphate groups present in the lipid A and core oligosaccharide regions. The repulsive forces due to accumulation of the negative charges are screened and bridged by the divalent cations (Mg 2+ and Ca 2+) that are known to be crucial for the integrity of the bacterial OM. Indeed, chelation of divalent cations is a well-established method to permeabilize Gram-negative bacteria such as Escherichia coli. Here, we use X-raymore » and neutron reflectivity (XRR and NR, respectively) techniques to examine the role of calcium ions in the stability of a model GNB-OM. Using XRR we show that Ca 2+ binds to the core region of the rough mutant LPS (RaLPS) films, producing more ordered structures in comparison to divalent cation free monolayers. Using recently developed solid-supported models of the GNB-OM, we study the effect of calcium removal on the asymmetry of DPPC:RaLPS bilayers. We show that without the charge screening effect of divalent cations, the LPS is forced to overcome the thermodynamically unfavorable energy barrier and flip across the hydrophobic bilayer to minimize the repulsive electrostatic forces, resulting in about 20% mixing of LPS and DPPC between the inner and outer bilayer leaflets. These results reveal for the first time the molecular details behind the well-known mechanism of outer membrane stabilization by divalent cations. This confirms the relevance of the asymmetric models for future studies of outer membrane stability and antibiotic penetration.« less

Effect of Divalent Cation Removal on the Structure of Gram-Negative Bacterial Outer Membrane Models

DOE PAGES

Clifton, Luke A.; Skoda, Maximilian W. A.; Le Brun, Anton P.; ...

2014-12-09

The Gram-negative bacterial outer membrane (GNB-OM) is asymmetric in its lipid composition with a phospholipid-rich inner leaflet and an outer leaflet predominantly composed of lipopolysaccharides (LPS). LPS are polyanionic molecules, with numerous phosphate groups present in the lipid A and core oligosaccharide regions. The repulsive forces due to accumulation of the negative charges are screened and bridged by the divalent cations (Mg 2+ and Ca 2+) that are known to be crucial for the integrity of the bacterial OM. Indeed, chelation of divalent cations is a well-established method to permeabilize Gram-negative bacteria such as Escherichia coli. Here, we use X-raymore » and neutron reflectivity (XRR and NR, respectively) techniques to examine the role of calcium ions in the stability of a model GNB-OM. Using XRR we show that Ca 2+ binds to the core region of the rough mutant LPS (RaLPS) films, producing more ordered structures in comparison to divalent cation free monolayers. Using recently developed solid-supported models of the GNB-OM, we study the effect of calcium removal on the asymmetry of DPPC:RaLPS bilayers. We show that without the charge screening effect of divalent cations, the LPS is forced to overcome the thermodynamically unfavorable energy barrier and flip across the hydrophobic bilayer to minimize the repulsive electrostatic forces, resulting in about 20% mixing of LPS and DPPC between the inner and outer bilayer leaflets. These results reveal for the first time the molecular details behind the well-known mechanism of outer membrane stabilization by divalent cations. This confirms the relevance of the asymmetric models for future studies of outer membrane stability and antibiotic penetration.« less

Effect of Divalent Cation Removal on the Structure of Gram-Negative Bacterial Outer Membrane Models

PubMed Central

2014-01-01

The Gram-negative bacterial outer membrane (GNB-OM) is asymmetric in its lipid composition with a phospholipid-rich inner leaflet and an outer leaflet predominantly composed of lipopolysaccharides (LPS). LPS are polyanionic molecules, with numerous phosphate groups present in the lipid A and core oligosaccharide regions. The repulsive forces due to accumulation of the negative charges are screened and bridged by the divalent cations (Mg2+ and Ca2+) that are known to be crucial for the integrity of the bacterial OM. Indeed, chelation of divalent cations is a well-established method to permeabilize Gram-negative bacteria such as Escherichia coli. Here, we use X-ray and neutron reflectivity (XRR and NR, respectively) techniques to examine the role of calcium ions in the stability of a model GNB-OM. Using XRR we show that Ca2+ binds to the core region of the rough mutant LPS (RaLPS) films, producing more ordered structures in comparison to divalent cation free monolayers. Using recently developed solid-supported models of the GNB-OM, we study the effect of calcium removal on the asymmetry of DPPC:RaLPS bilayers. We show that without the charge screening effect of divalent cations, the LPS is forced to overcome the thermodynamically unfavorable energy barrier and flip across the hydrophobic bilayer to minimize the repulsive electrostatic forces, resulting in about 20% mixing of LPS and DPPC between the inner and outer bilayer leaflets. These results reveal for the first time the molecular details behind the well-known mechanism of outer membrane stabilization by divalent cations. This confirms the relevance of the asymmetric models for future studies of outer membrane stability and antibiotic penetration. PMID:25489959

Tissue response to five commercially available peritoneal adhesion barriers-A systematic histological evaluation.

PubMed

Schmitt, Volker H; Mamilos, Andreas; Schmitt, Christine; Neitzer-Planck, Constanze N E; Rajab, Taufiek K; Hollemann, David; Wagner, Willi; Krämer, Bernhard; Hierlemann, Helmut; James Kirkpatrick, C; Brochhausen, Christoph

2018-02-01

Separating wounded serosa by physical barriers is the only clinically approved adjunct for postoperative adhesion prevention. Since the optimal adhesion barrier has not been found, it is essential to improve our pathogenic understanding of adhesion formation and to compare the effects of different barrier materials on tissue and cells. Wistar rats underwent standardized peritoneal damage and were treated either with Seprafilm, Adept, Intercoat, Spraygel, SupraSeal or remained untreated as a control. 14 days postoperatively, the lesions were explanted and histomorphologically analyzed using the European ISO score to evaluate material implants. Striking differences between the material groups were present regarding the inflammation, fibrosis, and foreign body reaction. According to the ISO score, Intercoat and Spraygel were considered as nonirritating to tissue. Adept, Seprafilm, and SupraSeal were assessed as mild-irritating materials. Interestingly, the most effective material in adhesion prevention revealed moderate inflammation accompanied by minor fibrosis. The degree of inflammation to barrier materials does not predict the efficacy in the prevention of adhesions. Histopathological investigations are crucial to improve our understanding of the cellular mechanisms during adhesion formation and elucidate the tissue response to material approaches used in adhesion prevention. This will lead to improved antiadhesive strategies and the development of functional barrier biomaterials. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 598-609, 2018. © 2017 Wiley Periodicals, Inc.

Quantification of pore clogging characteristics in potential permeable reactive barrier (PRB) substrates using image analysis.

PubMed

Wantanaphong, J; Mooney, S J; Bailey, E H

2006-08-10

Permeable reactive barriers (PRBs) are now an established approach for groundwater remediation. However, one concern is the deterioration of barrier material performance due to pore clogging. This study sought to quantify the effect of pore clogging on the alteration of the physical porous architecture of two novel potential PRB materials (clinoptilolite and calcified seaweed) using image analysis of SEM-derived images. Results after a water treatment contaminated with heavy metals over periods of up to 10 months identified a decrease in porosity from c. 22% to c. 15% for calcified seaweed and from c. 22% to c. 18% for clinoptilolite. Porosity was reduced by as much as 37% in a calcified seaweed column that clogged. The mean pore size (2D) of both materials slightly decreased after water treatment with c. 11% reduction in calcified seaweed and c. 7% reduction in clinoptilolite. An increase in the proportion of crack-shaped pores was observed in both materials after the contaminated water treatment, most noticeably in the bottom of columns where contaminated water first reacted with the material. The distribution of pores (within a given image) derived from the distance transform indicated the largest morphological differences in materials was recorded in calcified seaweed columns, which is likely to impact significantly on their performance as barrier materials. The magnitude of porosity reduction over a short time period in relation to predicted barrier longevity suggest these and similar materials may be unsuited for barrier installation in their present form.

Wzi is an outer membrane lectin that underpins group 1 capsule assembly in Escherichia coli.

PubMed

Bushell, Simon R; Mainprize, Iain L; Wear, Martin A; Lou, Hubing; Whitfield, Chris; Naismith, James H

2013-05-07

Many pathogenic bacteria encase themselves in a polysaccharide capsule that provides a barrier to the physical and immunological challenges of the host. The mechanism by which the capsule assembles around the bacterial cell is unknown. Wzi, an integral outer-membrane protein from Escherichia coli, has been implicated in the formation of group 1 capsules. The 2.6 Å resolution structure of Wzi reveals an 18-stranded β-barrel fold with a novel arrangement of long extracellular loops that blocks the extracellular entrance and a helical bundle that plugs the periplasmic end. Mutagenesis shows that specific extracellular loops are required for in vivo capsule assembly. The data show that Wzi binds the K30 carbohydrate polymer and, crucially, that mutants functionally deficient in vivo show no binding to K30 polymer in vitro. We conclude that Wzi is a novel outer-membrane lectin that assists in the formation of the bacterial capsule via direct interaction with capsular polysaccharides. Copyright © 2013 Elsevier Ltd. All rights reserved.

A comparison of the endotoxin biosynthesis and protein oxidation pathways in the biogenesis of the outer membrane of Escherichia coli and Neisseria meningitidis

PubMed Central

Piek, Susannah; Kahler, Charlene M.

2012-01-01

The Gram-negative bacterial cell envelope consists of an inner membrane (IM) that surrounds the cytoplasm and an asymmetrical outer-membrane (OM) that forms a protective barrier to the external environment. The OM consists of lipopolysaccahride (LPS), phospholipids, outer membrane proteins (OMPs), and lipoproteins. Oxidative protein folding mediated by periplasmic oxidoreductases is required for the biogenesis of the protein components, mainly constituents of virulence determinants such as pili, flagella, and toxins, of the Gram-negative OM. Recently, periplasmic oxidoreductases have been implicated in LPS biogenesis of Escherichia coli and Neisseria meningitidis. Differences in OM biogenesis, in particular the transport pathways for endotoxin to the OM, the composition and role of the protein oxidation, and isomerization pathways and the regulatory networks that control them have been found in these two Gram-negative species suggesting that although form and function of the OM is conserved, the pathways required for the biosynthesis of the OM and the regulatory circuits that control them have evolved to suit the lifestyle of each organism. PMID:23267440

Control of Growth Within Drosophila Peripheral Nerves by Ras and Protein Kinase A

DTIC Science & Technology

2008-02-01

assistance and Kei Ito, Vanessa Auld, Marc Tatar, Hideyuki Okano, Sally Leevers, Ernst Hafen, Exelixis Corporation, and the Bloomington Drosophila Stock...and Auld, 1999) and were provided by Van - essa Auld (University of British Columbia, Vancouver, British Columbia, Canada) and Kei Ito (National...nerve barrier (Auld et al., 1995) and an outer, meso- dermally derived perineurial glia ( Edwards et al., 1993). A trans- mission electron micrograph

Transmission line component testing for the ITER Ion Cyclotron Heating and Current Drive System

NASA Astrophysics Data System (ADS)

Goulding, Richard; Bell, G. L.; Deibele, C. E.; McCarthy, M. P.; Rasmussen, D. A.; Swain, D. W.; Barber, G. C.; Barbier, C. N.; Cambell, I. H.; Moon, R. L.; Pesavento, P. V.; Fredd, E.; Greenough, N.; Kung, C.

2014-10-01

High power RF testing is underway to evaluate transmission line components for the ITER Ion Cyclotron Heating and Current Drive System. The transmission line has a characteristic impedance Z0 = 50 Ω and a nominal outer diameter of 305 mm. It is specified to carry up to 6 MW at VSWR = 1.5 for 3600 s pulses, with transient voltages up to 40 kV. The transmission line is actively cooled, with turbulent gas flow (N2) used to transfer heat from the inner to outer conductor, which is water cooled. High voltage and high current testing of components has been performed using resonant lines generating steady state voltages of 35 kV and transient voltages up to 60 kV. A resonant ring, which has operated with circulating power of 6 MW for 1 hr pulses, is being used to test high power, low VSWR operation. Components tested to date include gas barriers, straight sections of various lengths, and 90 degree elbows. Designs tested include gas barriers fabricated from quartz and aluminum nitride, and transmission lines with quartz and alumina inner conductor supports. The latest results will be presented. This manuscript has been authored by UT-Battelle, LLC, under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy.

Snapshot recordings provide a first description of the acoustic signatures of deeper habitats adjacent to coral reefs of Moorea

PubMed Central

Parmentier, Eric; Berthe, Cécile; Besson, Marc; Hawkins, Anthony D.; Aubin, Thierry; Lecchini, David

2017-01-01

Acoustic recording has been recognized as a valuable tool for non-intrusive monitoring of the marine environment, complementing traditional visual surveys. Acoustic surveys conducted on coral ecosystems have so far been restricted to barrier reefs and to shallow depths (10–30 m). Since they may provide refuge for coral reef organisms, the monitoring of outer reef slopes and describing of the soundscapes of deeper environment could provide insights into the characteristics of different biotopes of coral ecosystems. In this study, the acoustic features of four different habitats, with different topographies and substrates, located at different depths from 10 to 100 m, were recorded during day-time on the outer reef slope of the north Coast of Moorea Island (French Polynesia). Barrier reefs appeared to be the noisiest habitats whereas the average sound levels at other habitats decreased with their distance from the reef and with increasing depth. However, sound levels were higher than expected by propagation models, supporting that these habitats possess their own sound sources. While reef sounds are known to attract marine larvae, sounds from deeper habitats may then also have a non-negligible attractive potential, coming into play before the reef itself. PMID:29158970

Radiolysis and Photolysis of Icy Satellite Surfaces: Experiments and Theory

NASA Technical Reports Server (NTRS)

Cassidy, T.; Coll, P.; Raulin, F.; Carlson, R. W.; Hand, K. P.; Johnson, R. E.; Loeffler, M. J.; Baragiola, R. A.

2010-01-01

The transport and exchange of material between bodies in the outer solar system is often facilitated by their exposure to ionizing radiation. With this in mind we review the effects of energetic ions, electrons and UV photons on materials present in the outer solar system. We consider radiolysis, photolysis, and sputtering of low temperature solids. Radiolysis and photolysis are the chemistry that follows the bond breaking and ionization produced by incident radiation, producing, e.g., O2 and H2 from irradiated H2O ice. Sputtering is the ejection of molecules by incident radiation. Both processes are particularly effective on ices in the outer solar system. Materials reviewed include H2O ice, sulfur-containing compounds (such as S02 and S8), carboncontajning compounds (such as CH4), nitrogen-containing compounds (such as NH3 and N2), and mixtures of those compounds. We also review the effects of ionizing radiation on a mixture of N2 and CH4 gases, as appropriate to Titan's upper atmosphere, where radiolysis and photolysis produce complex organic compounds (tholins).

Rescue of compromised lysosomes enhances degradation of photoreceptor outer segments and reduces lipofuscin-like autofluorescence in retinal pigmented epithelial cells.

PubMed

Guha, Sonia; Liu, Ji; Baltazar, Gabe; Laties, Alan M; Mitchell, Claire H

2014-01-01

Healthful cell maintenance requires the efficient degradative processing and removal of waste material. Retinal pigmented epithelial (RPE) cells have the onerous task of degrading both internal cellular debris generated through autophagy as well as phagocytosed photoreceptor outer segments. We propose that the inadequate processing material with the resulting accumulation of cellular waste contributes to the downstream pathologies characterized as age-related macular degeneration (AMD). The lysosomal enzymes responsible for clearance function optimally over a narrow range of acidic pH values; elevation of lysosomal pH by compounds like chloroquine or A2E can impair degradative enzyme activity and lead to a lipofuscin-like autofluorescence. Restoring acidity to the lysosomes of RPE cells can enhance activity of multiple degradative enzymes and is therefore a logical target in early AMD. We have identified several approaches to reacidify lysosomes of compromised RPE cells; stimulation of beta-adrenergic, A2A adenosine and D5 dopamine receptors each lowers lysosomal pH and improves degradation of outer segments. Activation of the CFTR chloride channel also reacidifies lysosomes and increases degradation. These approaches also restore the lysosomal pH of RPE cells from aged ABCA4(-/-) mice with chronically high levels of A2E, suggesting that functional signaling pathways to reacidify lysosomes are retained in aged cells like those in patients with AMD. Acidic nanoparticles transported to RPE lysosomes also lower pH and improve degradation of outer segments. In summary, the ability of diverse approaches to lower lysosomal pH and enhance outer segment degradation support the proposal that lysosomal acidification can prevent the accumulation of lipofuscin-like material in RPE cells.

49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

Code of Federal Regulations, 2010 CFR

2010-10-01

... Part 178 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR... Acceptance. (1) At least three specimens of the outer packaging materials must be tested; (2) Each test must...

Fireproof impact limiter aggregate packaging inside shipping containers

DOEpatents

Byington, Gerald A.; Oakes, Jr., Raymon Edgar; Feldman, Matthew Rookes

2001-01-01

The invention is a product and a process for making a fireproof, impact limiter, homogeneous aggregate material for casting inside a hazardous material shipping container, or a double-contained Type-B nuclear shipping container. The homogeneous aggregate material is prepared by mixing inorganic compounds with water, pouring the mixture into the void spaces between an inner storage containment vessel and an outer shipping container, vibrating the mixture inside the shipping container, with subsequent curing, baking, and cooling of the mixture to form a solidified material which encapsulates an inner storage containment vessel inside an outer shipping container. The solidified material forms a protective enclosure around an inner storage containment vessel which may store hazardous, toxic, or radioactive material. The solidified material forms a homogeneous fire-resistant material that does not readily transfer heat, and provides general shock and specific point-impact protection, providing protection to the interior storage containment vessel. The material is low cost, may contain neutron absorbing compounds, and is easily formed into a variety of shapes to fill the interior void spaces of shipping containers.

Elevated land runoff after European settlement perturbs persistent foraminiferal assemblages on the Great Barrier Reef.

PubMed

Uthicke, S; Patel, F; Ditchburn, R

2012-01-01

Coral reefs are under pressure from a variety of human-induced disturbances, but demonstration of ecosystem changes and identification of stressors are often difficult. We tested whether global change or increased agricultural runoff after European settlement of Northeast Australia (ca. 1860) has affected inshore reefs of the Great Barrier Reef. Eleven sediment cores were retrieved from inner reefs, intermediate reefs, and outer-island reefs, and benthic foraminiferal assemblages were analyzed in dated (14C, 210Pb, 137Cs) core sections (N = 82 samples). Data were grouped into six age bands (< 55, 55-150, 150-500, 500-1000, 1000-1500, and > 1500 yr). Principal component analysis and two-factor (Zone and Age) permutational analysis of variance (PERMANOVA) suggested that assemblages from the three zones were significantly different from each other over several millennia, with symbiont-bearing (mixotrophic) species dominating the outer reefs. A significant interaction term indicated that within-zone patterns varied. Assemblages in outer reefs unaffected from increased land runoff were persistent until present times. In both other zones, assemblages were also persistent until 150 yr ago, suggesting that benthic foraminiferal assemblages are naturally highly persistent over long (> 2000 yr) timescales. Assemblages in core sections < 55 yr old from inner reefs were significantly (post hoc t test) different from those older than 150 yr. Similarly, assemblages < 55 yr old from intermediate reefs were significantly different compared to older assemblages. A multivariate regression tree (environmental variables: Zone and Age) explained 56.8% of the variance in foraminiferal assemblages and confirmed patterns identified by PERMANOVA. With some exceptions, changes on the inner and intermediate reefs were consistent with a model predicting that increased nutrients and higher turbidity enhance relative abundance of heterotrophic species. Given that assemblages did not change in outer-island reefs (not impacted by runoff) we argue that changes in assemblages due to global change can be rejected as an explanation. Thus, the findings are more consistent with the hypothesis that agricultural runoff since European settlement altered foraminiferal assemblages than with the hypothesis that global forcing caused changes.

Citizen's dosimeter

DOEpatents

Klemic, Gladys [Naperville, IL; Bailey, Paul [Chicago, IL; Breheny, Cecilia [Yonkers, NY

2008-09-02

The present invention relates to a citizen's dosimeter. More specifically, the invention relates to a small, portable, personal dosimetry device designed to be used in the wake of a event involving a Radiological Dispersal Device (RDD), Improvised Nuclear Device (IND), or other event resulting in the contamination of large area with radioactive material or where on site personal dosimetry is required. The card sized dosimeter generally comprises: a lower card layer, the lower card body having an inner and outer side; a upper card layer, the layer card having an inner and outer side; an optically stimulated luminescent material (OSLM), wherein the OSLM is sandwiched between the inner side of the lower card layer and the inner side of the upper card layer during dosimeter radiation recording, a shutter means for exposing at least one side of the OSLM for dosimeter readout; and an energy compensation filter attached to the outer sides of the lower and upper card layers.

Heat gain from thermal radiation through protective clothing with different insulation, reflectivity and vapour permeability.

PubMed

Bröde, Peter; Kuklane, Kalev; Candas, Victor; Den Hartog, Emiel A; Griefahn, Barbara; Holmér, Ingvar; Meinander, Harriet; Nocker, Wolfgang; Richards, Mark; Havenith, George

2010-01-01

The heat transferred through protective clothing under long wave radiation compared to a reference condition without radiant stress was determined in thermal manikin experiments. The influence of clothing insulation and reflectivity, and the interaction with wind and wet underclothing were considered. Garments with different outer materials and colours and additionally an aluminised reflective suit were combined with different number and types of dry and pre-wetted underwear layers. Under radiant stress, whole body heat loss decreased, i.e., heat gain occurred compared to the reference. This heat gain increased with radiation intensity, and decreased with air velocity and clothing insulation. Except for the reflective outer layer that showed only minimal heat gain over the whole range of radiation intensities, the influence of the outer garments' material and colour was small with dry clothing. Wetting the underclothing for simulating sweat accumulation, however, caused differing effects with higher heat gain in less permeable garments.

Helmet of a laminate construction of polycarbonate and polysulfone polymeric material

NASA Technical Reports Server (NTRS)

Kosmo, Joseph J. (Inventor); Dawn, Frederic S. (Inventor)

1991-01-01

An article of laminate construction is disclosed which is comprised of an underlayer of polycarbonate polymer material to which is applied a chemically resistant outer layer of polysulfone. The layers which are joined by compression-heat molding, are molded to form the shape of a body protective shell such as a space helmet comprising a shell of polycarbonate, polysulfone laminate construction attached at its open end to a sealing ring adapted for connection to a space suit. The front portion of the shell provides a transparent visor for the helmet. An outer visor of polycarbonate polysulfone laminate construction is pivotally mounted to the sealing ring for covering the transparent visor portion of the shell during extravehicular activities. The polycarbonate under layer of the outer visor is coated on its inner surface with a vacuum deposit of gold to provide additional thermal radiation resistance.

Development of a high speed extrusion concept using a floating screw sleeve for solid-melt-separation

NASA Astrophysics Data System (ADS)

Karrenberg, Gregor; Wortberg, Johannes

2015-05-01

The High-Speed-S-Truder with floating screw sleeve is an alternative extrusion concept with solid-melt-separation. A fairly conventional 35 mm screw with a length of 21 D, which is accelerated by a 75 kW gearless, water cooled synchronous drive, conveys the resin into a 60 mm screw sleeve with a length of 10 D. Inside the sleeve the material is plasticizied and discharged into the outer screw channel of the sleeve through radial bores. Only the solid bed remains inside. The development of a melt pool - and thus a decrease of the plasticizing capacity - is avoided. The sleeve is rotated by drag forces only (approximately 10 - 15 % of the screw speed). Due to the low speed of the screw sleeve molten material is conveyed to a 4 D Dynamic Mixing Ring in a gentle manner. The DMRs floating ring and the screw sleeve are directly coupled. The granules in the screw channel are stopped by a barrier on the screw in front of the mixing device. So nearly no unmelted material can pass the system. For temperature management in the plastification and mixing zone a 3-zone heating/air-cooling system is used. Various kinds of experiments with the High-Speed S-Truder were conducted. Reachable throughputs with different types of material (LDPE, LLDPE, PP, PS) have been tested. Also three screw geometries, which are mainly varying in the channel depth, were compared. Experimental results and theoretical background will be described in this paper.

Historical changes in the Mississippi-Alabama barrier-island chain and the roles of extreme storms, sea level, and human activities

USGS Publications Warehouse

Morton, R.A.

2008-01-01

Barrier-island chains worldwide are undergoing substantial changes, and their futures remain uncertain. An historical analysis of a barrier-island chain in the north-central Gulf of Mexico shows that the Mississippi barriers are undergoing rapid systematic land loss and translocation associated with: (1) unequal lateral transfer of sand related to greater updrift erosion compared to downdrift deposition; (2) barrier narrowing resulting from simultaneous erosion of shores along the Gulf and Mississippi Sound; and (3) barrier segmentation related to storm breaching. Dauphin Island, Alabama, is also losing land for some of the same reasons as it gradually migrates landward. The principal causes of land loss are frequent intense storms, a relative rise in sea level, and a sediment-budget deficit. Considering the predicted trends for storms and sea level related to global warming, it is certain that the Mississippi-Alabama (MS-AL) barrier islands will continue to lose land area at a rapid rate unless the trend of at least one causal factor reverses. Historical land-loss trends and engineering records show that progressive increases in land-loss rate correlate with nearly simultaneous deepening of channels dredged across the outer bars of the three tidal inlets maintained for deep-draft shipping. This correlation indicates that channel-maintenance activities along the MS-AL barriers have impacted the sediment budget by disrupting the alongshore sediment transport system and progressively reducing sand supply. Direct management of this causal factor can be accomplished by strategically placing dredged sediment where adjacent barrier-island shores will receive it for island nourishment and rebuilding.

Understanding barriers to fruit and vegetable intake in the Australian Longitudinal Study of Indigenous Children: a mixed-methods approach.

PubMed

Thurber, Katherine Ann; Banwell, Cathy; Neeman, Teresa; Dobbins, Timothy; Pescud, Melanie; Lovett, Raymond; Banks, Emily

2017-04-01

To identify barriers to fruit and vegetable intake for Indigenous Australian children and quantify factors related to these barriers, to help understand why children do not meet recommendations for fruit and vegetable intake. We examined factors related to carer-reported barriers using multilevel Poisson models (robust variance); a key informant focus group guided our interpretation of findings. Eleven diverse sites across Australia. Australian Indigenous children and their carers (N 1230) participating in the Longitudinal Study of Indigenous Children. Almost half (45 %; n 555/1230) of carers reported barriers to their children's fruit and vegetable intake. Dislike of fruit and vegetables was the most common barrier, reported by 32·9 % of carers; however, we identified few factors associated with dislike. Carers were more than ten times less likely to report barriers to accessing fruit and vegetables if they lived large cities v. very remote areas. Within urban and inner regional areas, child and carer well-being, financial security, suitable housing and community cohesion promoted access to fruit and vegetables. In this national Indigenous Australian sample, almost half of carers faced barriers to providing their children with a healthy diet. Both remote/outer regional carers and disadvantaged urban/inner regional carers faced problems accessing fruit and vegetables for their children. Where vegetables were accessible, children's dislike was a substantial barrier. Nutrition promotion must address the broader family, community, environmental and cultural contexts that impact nutrition, and should draw on the strengths of Indigenous families and communities.

Impact of Hurricane Sandy on the Shoreface and Inner Shelf, Offshore Long Island: Evidence for Ravinement?

NASA Astrophysics Data System (ADS)

Goff, J. A.; Austin, J. A.; Flood, R. D.; Schwab, W. C.; Denny, J. F.; Christensen, B. A.; Browne, C. M.; Saustrup, S.

2013-12-01

In January 2013, approximately two months after Hurricane Sandy made landfall in the Mid-Atlantic Bight, a scientific team from the University of Texas Institute for Geophysics, partnering with colleagues at Adelphi and Stony Brook universities and the USGS, conducted marine geophysical and surficial sampling surveys both offshore and in the inshore bays of Long Island, NY. The primary scientific goal was to assess the impact of the storm on the shoreface and inner shelf. Sandy made landfall as a post-tropical cyclone near Brigantine, NJ, with 70-kt maximum sustained winds. However, its unusual trajectory and massive size created record storm surges along the heavily-populated NJ and NY coastlines. As a result, infrastructure in the NY metropolitan area was damaged, and the Long Island barrier island system was both breached in places and elsewhere seriously eroded. The surveys included ten days of operations aboard Stony Brook's R/V Seawolf, offshore of Long Beach and Fire Island, barrier islands south of Long Island, complementing ongoing land-based studies of Sandy's impact on the NY-NJ barrier island system. Data collection involved multibeam bathymetric swath mapping, CHIRP very high resolution acoustic subbottom profiling, and surface sediment (grab) sampling to provide ground truth for the geophysical data. We surveyed regions that had been previously surveyed, both by Stony Brook in 2001 and 2005 to support reef management, and by the USGS for coastal sedimentary research, most recently in 2011 offshore Fire Island. These areas include shoreface-attached sand ridges that may be exchanging sand with the barrier island shoreface. We focus on before-and-after data comparisons on the shoreface and inner shelf, searching in particular for evidence that the storm contributed significantly to ravinement, either by wave- or current-forced erosion along the shoreface or via migration of shoreface-attached or detached sand ridges on the inner shelf. The interpreted (Holocene) transgressive ravinement surface, which may have been modified in part by Sandy, is frequently well-imaged in CHIRP data on the inner- to outer shelf; it represents the physical contrast between Holocene sands above and either Holocene estuarine (often residing in buried river channels) or older (Pleistocene) material below, typically with coarser-grained lag material at the interface. However, the process of ravinement in response to shelf-wide base-level changes is not well understood, and is also difficult to observe because it presumably happens during the most inclement of conditions. Our study provides an opportunity to investigate the ravinement process directly in response to a specific event, to link that process to the stratigraphic record, and therefore to gauge one large storm's contribution to this important part of the sediment budget for inner shelf/beach barrier systems.

Absorbent product and articles made therefrom

NASA Technical Reports Server (NTRS)

Dawn, F. S.; Correale, J. V. (Inventor)

1982-01-01

A multilayer absorbent product for use in contact with the skin to absorb fluids is described. The product has a water pervious facing layer for contacting the skin, and a first fibrous wicking layer overlaying the water pervious layer. A first container section is defined by inner and outer layers of a water pervious wicking material in between a first absorbent mass and a second container section defined by inner and outer layers of a water pervious wicking material between what is disposed a second absorbent mass, and a liquid impermeable/gas permeable layer overlaying the second fibrous wicking layer.

Shipping container for fissile material

DOEpatents

Crowder, H.E.

1984-12-17

The present invention is directed to a shipping container for the interstate transportation of enriched uranium materials. The shipping container is comprised of a rigid, high-strength, cylindrical-shaped outer vessel lined with thermal insulation. Disposed inside the thermal insulation and spaced apart from the inner walls of the outer vessel is a rigid, high-strength, cylindrical inner vessel impervious to liquid and gaseous substances and having the inner surfaces coated with a layer of cadmium to prevent nuclear criticality. The cadmium is, in turn, lined with a protective shield of high-density urethane for corrosion and wear protection. 2 figs.

Urey Prize Lecture - Planetary evolution and the origin of life

NASA Technical Reports Server (NTRS)

Mckay, Christopher P.

1991-01-01

One of the principal questions concerning planetary evolution and life's origins relates to the early-earth organic material's origination in situ, outer solar system importation, or simple irrelevance to the emergence of organisms. Additional considerations encompass the character of interstellar organic material and its relationship to outer solar system organic compounds, and the possibility of life's emergence in the early Mars. Attention is given to the essentiality of liquid water for life-forms, in the role not only of a reaction medium among molecules but that of a basis for hydrophylic and hydrophobic groups' bonding.

Multi-modality nanoparticles having optically responsive shape

DOEpatents

Chen, Fanqing; Bouchard, Louis-Serge

2015-05-19

In certain embodiments novel nanoparticles (nanowontons) are provided that are suitable for multimodal imaging and/or therapy. In one embodiment, the nanoparticles include a first biocompatible (e.g., gold) layer, an inner core layer (e.g., a non-biocompatible material), and a biocompatible (e.g., gold) layer. The first gold layer includes a concave surface that forms a first outer surface of the layered nanoparticle. The second gold layer includes a convex surface that forms a second outer surface of the layered nanoparticle. The first and second gold layers encapsulate the inner core material layer. Methods of fabricating such nanoparticles are also provided.

Reflectance spectrophotometry (about 0.5-1.0 micron) of oute-belt asteroids - Implications for primitive, organic solar system material

NASA Technical Reports Server (NTRS)

Vilas, F.; Smith, B. A.

1985-01-01

The surface compositions of outer-belt asteroids were used to obtain information about the origin of these asteroids. High-resolution CCD reflectance spectra of 21 asteroids, primarily P class, were examined for compositional information. Distinct slope changes are observed that suggest that these asteroids are the remnants of a compositional gradation of planetesimals in the outer solar system, which were retained selectively in location when other material was ejected from the solar system. Other data suggest that this gradation could extend through the orbits of Uranus and Neptune.

Hubble Space Telescope Thermal Blanket Repair Design and Implementation

NASA Technical Reports Server (NTRS)

Ousley, Wes; Skladany, Joseph; Dell, Lawrence

2000-01-01

Substantial damage to the outer layer of Hubble Space Telescope (HST) thermal blankets was observed during the February 1997 servicing mission. After six years in LEO, many areas of the aluminized Teflon(R) outer blanket layer had significant cracks, and some material was peeled away to expose inner layers to solar flux. After the mission, the failure mechanism was determined, and repair materials and priorities were selected for follow-on missions. This paper focuses on the thermal, mechanical, and EVA design requirements for the blanket repair, the creative solutions developed for these unique problems, hardware development, and testing.

Element of an inductive coupler

DOEpatents

Hall, David R.; Fox, Joe

2006-08-15

An element for an inductive coupler in a downhole component comprises magnetically conductive material, which is disposed in a recess in annular housing. The magnetically conductive material forms a generally circular trough. The circular trough comprises an outer generally U-shaped surface, an inner generally U-shaped surface, and two generally planar surfaces joining the inner and outer surfaces. The element further comprises pressure relief grooves in at least one of the surfaces of the circular trough. The pressure relief grooves may be scored lines. Preferably the pressure relief grooves are parallel to the magnetic field generated by the magnetically conductive material. The magnetically conductive material is selected from the group consisting of soft iron, ferrite, a nickel iron alloy, a silicon iron alloy, a cobalt iron alloy, and a mu-metal. Preferably, the annular housing is a metal ring.

Material Barriers to Diffusive Mixing

NASA Astrophysics Data System (ADS)

Haller, George; Karrasch, Daniel

2017-11-01

Transport barriers, as zero-flux surfaces, are ill-defined in purely advective mixing in which the flux of any passive scalar is zero through all material surfaces. For this reason, Lagrangian Coherent Structures (LCSs) have been argued to play the role of mixing barriers as most repelling, attracting or shearing material lines. These three kinematic concepts, however, can also be defined in different ways, both within rigorous mathematical treatments and within the realm of heuristic diagnostics. This has lead to a an ever-growing number of different LCS methods, each generally identifying different objects as transport barriers. In this talk, we examine which of these methods have actual relevance for diffusive transport barriers. The latter barriers are arguably the practically relevant inhibitors in the mixing of physically relevant tracers, such as temperature, salinity, vorticity or potential vorticity. We demonstrate the role of the most effective diffusion barriers in analytical examples and observational data. Supported in part by the DFG Priority Program on Turbulent Superstructures.

Self sterilization of bodies during outer planet entry. [atmospheric temperature effects

NASA Technical Reports Server (NTRS)

Hoffman, A. R.; Jaworski, W.; Taylor, D. M.

1975-01-01

As a body encounters the atmosphere of an outer planet, whether accidentally or by plan, it will be subjected to heat loads which could result in high temperature conditions that render terrestrial organisms on or within the body non-viable. To determine whether an irregularly shaped entering body, consisting of several different materials, would be sterilized during inadvertent entry at high velocity, the thermal response of a typical outer planet spacecraft instrument was studied. The results indicate that the Teflon-insulated cable and electronic circuit boards may not experience sterilizing temperatures during a Jupiter, Saturn, or Titan entry. Another conclusion of the study is that small plastic particles entering Saturn from outer space have wider survival corridors than do those at Jupiter.

Inner- and outer-wall sorting of double-walled carbon nanotubes

NASA Astrophysics Data System (ADS)

Li, Han; Gordeev, Georgy; Wasserroth, Sören; Chakravadhanula, Venkata Sai Kiran; Neelakandhan, Shyam Kumar Chethala; Hennrich, Frank; Jorio, Ado; Reich, Stephanie; Krupke, Ralph; Flavel, Benjamin Scott

2017-12-01

Double-walled carbon nanotubes (DWCNTs) consist of two coaxially aligned single-walled carbon nanotubes (SWCNTs), and previous sorting methods only achieved outer-wall electronic-type selectivity. Here, a separation technique capable of sorting DWCNTs by semiconducting (S) or metallic (M) inner- and outer-wall electronic type is presented. Electronic coupling between the inner and outer wall is used to alter the surfactant coating around each of the DWCNT types, and aqueous gel permeation is used to separate them. Aqueous methods are used to remove SWCNT species from the raw material and prepare enriched DWCNT fractions. The enriched DWCNT fractions are then transferred into either chlorobenzene or toluene using the copolymer PFO-BPy to yield the four inner@outer combinations of M@M, M@S, S@M and S@S. The high purity of the resulting fractions is verified by absorption measurements, transmission electron microscopy, atomic force microscopy, resonance Raman mapping and high-density field-effect transistor devices.

Turbine vane with high temperature capable skins

DOEpatents

Morrison, Jay A [Oviedo, FL

2012-07-10

A turbine vane assembly includes an airfoil extending between an inner shroud and an outer shroud. The airfoil can include a substructure having an outer peripheral surface. At least a portion of the outer peripheral surface is covered by an external skin. The external skin can be made of a high temperature capable material, such as oxide dispersion strengthened alloys, intermetallic alloys, ceramic matrix composites or refractory alloys. The external skin can be formed, and the airfoil can be subsequently bi-cast around or onto the skin. The skin and the substructure can be attached by a plurality of attachment members extending between the skin and the substructure. The skin can be spaced from the outer peripheral surface of the substructure such that a cavity is formed therebetween. Coolant can be supplied to the cavity. Skins can also be applied to the gas path faces of the inner and outer shrouds.

Electronic transport properties of inner and outer shells in near ohmic-contacted double-walled carbon nanotube transistors

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

Zhang, Yuchun; Zhou, Liyan; Zhao, Shangqian

2014-06-14

We investigate electronic transport properties of field-effect transistors based on double-walled carbon nanotubes, of which inner shells are metallic and outer shells are semiconducting. When both shells are turned on, electron-phonon scattering is found to be the dominant phenomenon. On the other hand, when outer semiconducting shells are turned off, a zero-bias anomaly emerges in the dependence of differential conductance on the bias voltage, which is characterized according to the Tomonaga-Luttinger liquid model describing tunneling into one-dimensional materials. We attribute these behaviors to different contact conditions for outer and inner shells of the double-walled carbon nanotubes. A simple model combiningmore » Luttinger liquid model for inner metallic shells and electron-phonon scattering in outer semiconducting shells is given here to explain our transport data at different temperatures.« less

Inner- and outer-wall sorting of double-walled carbon nanotubes.

PubMed

Li, Han; Gordeev, Georgy; Wasserroth, Sören; Chakravadhanula, Venkata Sai Kiran; Neelakandhan, Shyam Kumar Chethala; Hennrich, Frank; Jorio, Ado; Reich, Stephanie; Krupke, Ralph; Flavel, Benjamin Scott

2017-12-01

Double-walled carbon nanotubes (DWCNTs) consist of two coaxially aligned single-walled carbon nanotubes (SWCNTs), and previous sorting methods only achieved outer-wall electronic-type selectivity. Here, a separation technique capable of sorting DWCNTs by semiconducting (S) or metallic (M) inner- and outer-wall electronic type is presented. Electronic coupling between the inner and outer wall is used to alter the surfactant coating around each of the DWCNT types, and aqueous gel permeation is used to separate them. Aqueous methods are used to remove SWCNT species from the raw material and prepare enriched DWCNT fractions. The enriched DWCNT fractions are then transferred into either chlorobenzene or toluene using the copolymer PFO-BPy to yield the four inner@outer combinations of M@M, M@S, S@M and S@S. The high purity of the resulting fractions is verified by absorption measurements, transmission electron microscopy, atomic force microscopy, resonance Raman mapping and high-density field-effect transistor devices.

Densification control and analysis of outer shell of new high-temperature vacuum insulated composite

NASA Astrophysics Data System (ADS)

Wang, Yang; Chen, Zhaofeng; Jiang, Yun; Yu, Shengjie; Xu, Tengzhou; Li, Binbin; Chen, Zhou

2017-11-01

A novel high temperature vacuum insulated composite with low thermal conductivity composed of SiC foam core material and sealing outer shell is discussed, which will have a great potential to be used as thermal protection system material. In this composite, the outer shell is the key to maintain its internal vacuum, which is consisted of 2.5D C/C and SiC coating. So the densification processes of outer shell, including 2.5D braiding process, chemical vapor infiltration (CVI) pyrolytic carbon (PyC) process, polymer infiltration and pyrolysis (PIP) glassy carbon (GC) process and chemical vapor deposition (CVD) SiC process, are focused in this paper. The measuring result of the gas transmission quantity of outer shell is only 0.14 cm3/m2 · d · Pa after 5 times CVD processes, which is two order of magnitude lower than that sample deposited one time. After 10 times thermal shock cycles, the gas transmission quantity increases to 1.2 cm3/m2 · d · Pa. The effective thermal conductivity of high temperature vacuum insulated composite ranged from 0.19 W m-1 K-1 to 0.747 W m-1 K-1 within the temperature from 20 °C to 900 °C. Even after 10 thermal shock cycles, the variation of the effective thermal conductivity is still consistent with that without treatments.

40 CFR 265.1100 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

...: (1) A primary barrier designed and constructed of materials to prevent migration of hazardous... constructed of materials to prevent migration of hazardous constituents into the barrier, with a leak...

40 CFR 265.1100 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

...: (1) A primary barrier designed and constructed of materials to prevent migration of hazardous... constructed of materials to prevent migration of hazardous constituents into the barrier, with a leak...

40 CFR 265.1100 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

...: (1) A primary barrier designed and constructed of materials to prevent migration of hazardous... constructed of materials to prevent migration of hazardous constituents into the barrier, with a leak...

40 CFR 265.1100 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

...: (1) A primary barrier designed and constructed of materials to prevent migration of hazardous... constructed of materials to prevent migration of hazardous constituents into the barrier, with a leak...

40 CFR 265.1100 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

...: (1) A primary barrier designed and constructed of materials to prevent migration of hazardous... constructed of materials to prevent migration of hazardous constituents into the barrier, with a leak...

46 CFR 38.05-1 - Design and construction of vessels-general-TB/ALL.

Code of Federal Regulations, 2012 CFR

2012-10-01

... so arranged as to prevent the flow of cargo vapor from the weather deck into such spaces. In this... secondary barrier is required, the material of that barrier and of contiguous hull structure shall have... within the secondary barrier. Materials used in the fabrication of the cargo containment and handling...

46 CFR 38.05-1 - Design and construction of vessels-general-TB/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... so arranged as to prevent the flow of cargo vapor from the weather deck into such spaces. In this... secondary barrier is required, the material of that barrier and of contiguous hull structure shall have... within the secondary barrier. Materials used in the fabrication of the cargo containment and handling...

46 CFR 38.05-1 - Design and construction of vessels-general-TB/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... so arranged as to prevent the flow of cargo vapor from the weather deck into such spaces. In this... secondary barrier is required, the material of that barrier and of contiguous hull structure shall have... within the secondary barrier. Materials used in the fabrication of the cargo containment and handling...

Sensitization by heat treatment of Escherichia coli K-12 cells to hydrophobic antibacterial compounds.

PubMed Central

Tsuchido, T; Takano, M

1988-01-01

The sensitivities of intact and heat-injured cells of Escherichia coli K-12 to several antibacterial compounds were measured by the prolongation of growth delay. Cells exposed to sublethal heat became more sensitive to various hydrophobic compounds, such as medium-chain fatty acids, alkyl esters of p-hydroxybenzoic acid, and some kinds of antibiotics or dyes, than unheated cells; but there was a smaller or no increase in sensitivity to short-chain fatty acids, chloramphenicol, and vancomycin. The destruction by heat of a permeability barrier of the outer membrane may have sensitized the cells to hydrophobic compounds. The sensitization was much lower for a strain defective in lipopolysaccharide, which is important as a barrier against hydrophobic compounds. PMID:3075437

Diffusion barriers

NASA Technical Reports Server (NTRS)

Nicolet, M. A.

1983-01-01

The choice of the metallic film for the contact to a semiconductor device is discussed. One way to try to stabilize a contact is by interposing a thin film of a material that has low diffusivity for the atoms in question. This thin film application is known as a diffusion barrier. Three types of barriers can be distinguished. The stuffed barrier derives its low atomic diffusivity to impurities that concentrate along the extended defects of a polycrystalline layer. Sacrificial barriers exploit the fact that some (elemental) thin films react in a laterally uniform and reproducible fashion. Sacrificial barriers have the advantage that the point of their failure is predictable. Passive barriers are those most closely approximating an ideal barrier. The most-studied case is that of sputtered TiN films. Stuffed barriers may be viewed as passive barriers whose low diffusivity material extends along the defects of the polycrystalline host.

Impact of initial catalyst form on the 3D structure and performance of ball-milled Ni-catalyzed MgH 2 for hydrogen storage

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

House, Stephen D.; Vajo, John J.; Ren, Chai

Although it has been shown that the hydrogen storage kinetics of metal hydrides can be significantly improved by the addition of transition metal-based catalysts, relatively little attention has been paid to the impact that the form in which these catalysts are introduced during synthesis has on the resulting structure and how this alters performance. Two mixtures of MgH 2 doped with Ni were prepared via high-energy ball-milling under identical conditions, one using a pure Ni nanopowder catalyst and the other using anhydrous NiCl 2. The resulting Ni catalyst particles of the NiCl 2-doped material were 10-100 times smaller, as wellmore » as more uniform in size and shape. Electron tomography revealed that the additive form also altered its incorporation and 3D spatial distribution, with Ni particles limited to the outer surface in the NiCl 2-doped case. The significantly lower desorption performance measured in the NiCl 2-doped material is attributed to regions of MgCl 2 acting as barriers between the MgH 2 and Ni, hindering the ability of the latter to effectively catalyze the reactions. Finally, this work demonstrates the hazards in assuming different catalyst forms produce similar final structures and highlights the potential of catalyst form as a synthesis tool for optimizing the material structure and performance.« less

Impact of initial catalyst form on the 3D structure and performance of ball-milled Ni-catalyzed MgH 2 for hydrogen storage

DOE PAGES

House, Stephen D.; Vajo, John J.; Ren, Chai; ...

2017-02-24

Although it has been shown that the hydrogen storage kinetics of metal hydrides can be significantly improved by the addition of transition metal-based catalysts, relatively little attention has been paid to the impact that the form in which these catalysts are introduced during synthesis has on the resulting structure and how this alters performance. Two mixtures of MgH 2 doped with Ni were prepared via high-energy ball-milling under identical conditions, one using a pure Ni nanopowder catalyst and the other using anhydrous NiCl 2. The resulting Ni catalyst particles of the NiCl 2-doped material were 10-100 times smaller, as wellmore » as more uniform in size and shape. Electron tomography revealed that the additive form also altered its incorporation and 3D spatial distribution, with Ni particles limited to the outer surface in the NiCl 2-doped case. The significantly lower desorption performance measured in the NiCl 2-doped material is attributed to regions of MgCl 2 acting as barriers between the MgH 2 and Ni, hindering the ability of the latter to effectively catalyze the reactions. Finally, this work demonstrates the hazards in assuming different catalyst forms produce similar final structures and highlights the potential of catalyst form as a synthesis tool for optimizing the material structure and performance.« less

Thermoelastic analysis of non-uniform pressurized functionally graded cylinder with variable thickness using first order shear deformation theory(FSDT) and perturbation method

NASA Astrophysics Data System (ADS)

Khoshgoftar, M. J.; Mirzaali, M. J.; Rahimi, G. H.

2015-11-01

Recently application of functionally graded materials(FGMs) have attracted a great deal of interest. These materials are composed of various materials with different micro-structures which can vary spatially in FGMs. Such composites with varying thickness and non-uniform pressure can be used in the aerospace engineering. Therefore, analysis of such composite is of high importance in engineering problems. Thermoelastic analysis of functionally graded cylinder with variable thickness under non-uniform pressure is considered. First order shear deformation theory and total potential energy approach is applied to obtain the governing equations of non-homogeneous cylinder. Considering the inner and outer solutions, perturbation series are applied to solve the governing equations. Outer solution for out of boundaries and more sensitive variable in inner solution at the boundaries are considered. Combining of inner and outer solution for near and far points from boundaries leads to high accurate displacement field distribution. The main aim of this paper is to show the capability of matched asymptotic solution for different non-homogeneous cylinders with different shapes and different non-uniform pressures. The results can be used to design the optimum thickness of the cylinder and also some properties such as high temperature residence by applying non-homogeneous material.

40 CFR 264.1100 - Applicability.

Code of Federal Regulations, 2014 CFR

2014-07-01

... designed and constructed of materials to prevent migration of hazardous constituents into the barrier; (2... materials to prevent migration of hazardous constituents into the barrier, with a leak detection and liquid...

40 CFR 264.1100 - Applicability.

Code of Federal Regulations, 2013 CFR

2013-07-01

... designed and constructed of materials to prevent migration of hazardous constituents into the barrier; (2... materials to prevent migration of hazardous constituents into the barrier, with a leak detection and liquid...

40 CFR 264.1100 - Applicability.

Code of Federal Regulations, 2012 CFR

2012-07-01

... designed and constructed of materials to prevent migration of hazardous constituents into the barrier; (2... materials to prevent migration of hazardous constituents into the barrier, with a leak detection and liquid...

40 CFR 264.1100 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-07-01

... designed and constructed of materials to prevent migration of hazardous constituents into the barrier; (2... materials to prevent migration of hazardous constituents into the barrier, with a leak detection and liquid...

40 CFR 264.1100 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... designed and constructed of materials to prevent migration of hazardous constituents into the barrier; (2... materials to prevent migration of hazardous constituents into the barrier, with a leak detection and liquid...

Cryogenic Insulation System

NASA Technical Reports Server (NTRS)

Davis, Randall C. (Inventor); Taylor, Allan H. (Inventor); Jackson, L. Robert (Inventor); Mcauliffe, Patrick S. (Inventor)

1988-01-01

This invention relates to reusable, low density, high temperature cryogenic foam insulation systems and the process for their manufacture. A pacing technology for liquid hydrogen fueled, high speed aircraft is the development of a fully reusable, flight weight cryogenic insulation system for propellant tank structures. In the invention cryogenic foam insulation is adhesively bonded to the outer wall of the fuel tank structure. The cryogenic insulation consists of square sheets fabricated from an array of abutting square blocks. Each block consists of a sheet of glass cloth adhesively bonded between two layers of polymethacrylimide foam. Each block is wrapped in a vapor impermeable membrane, such as Kapton(R) aluminum Kapton(R), to provide a vapor barrier. Very beneficial results can be obtained by employing the present invention in conjunction with fibrous insulation and an outer aeroshell, a hot fuselage structure with an internal thermal protection system.

On the characteristics and scales of outer bank roughness on large meander bends: the influence of bank material properties, floodplain vegetation and flow inundation

USDA-ARS?s Scientific Manuscript database

This paper explores the scales and characteristics of form roughness along the outer banks of two bends on a large meandering river through investigation of irregularities in bank contours and local topographic variability on the bank face. The analysis also examines how roughness varies over the ve...

Blowout Surge due to Interaction between a Solar Filament and Coronal Loops

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

Li, Haidong; Jiang, Yunchun; Yang, Jiayan

2017-06-20

We present an observation of the interaction between a filament and the outer spine-like loops that produces a blowout surge within one footpoint of large-scale coronal loops on 2015 February 6. Based the observation of the AIA 304 and 94 Å, the activated filament is initially embedded below a dome of a fan-spine configuration. Due to the ascending motion, the erupting filament reconnects with the outer spine-like field. We note that the material in the filament blows out along the outer spine-like field to form the surge with a wider spire, and a two-ribbon flare appears at the site ofmore » the filament eruption. In this process, small bright blobs appear at the interaction region and stream up along the outer spine-like field and down along the eastern fan-like field. As a result, a leg of the filament becomes radial and the material in it erupts, while another leg forms the new closed loops. Our results confirm that the successive reconnection occurring between the erupting filament and the coronal loops may lead to a strong thermal/magnetic pressure imbalance, resulting in a blowout surge.« less

Histochemistry and ultrastructure of the metacercarial cysts of blackspot trematodes Uvulifer ambloplitis and Neascus pyriformis.

PubMed

Wittrock, D D; Bruce, C S; Johnson, A D

1991-06-01

Cysts of Uvulifer ambloplitis from green sunfish, Lepomis cyanellus, and Neascus pyriformis from red shiners, Notropis lutrensis, were studied with light-level histochemistry and scanning and transmission electron microscopy. Cysts of both species are bilayered, consisting of an outer host capsule and an inner parasite cyst; the space between these layers is filled with a viscous material. The outer portion of the host capsule of both species is composed of fibrocytes, melanin granules, and collagen fibrils, and the inner portion of layers of flattened fibrocytes. The parasite cyst of U. ambloplitis is formed of 2 layers, an outer dense layer and an inner light layer, whereas the parasite cyst of N. pyriformis is made of 3 layers. A thin outer light-staining layer is present in addition to the 2 layers observed in U. ambloplitis. Results of histochemical staining were the same for both species. The host capsule stained positively for proteins and neutral and acid mucopolysaccharides. The viscous material was positive for neutral and acid mucopolysaccharides but not for proteins. The parasite cyst gave a strong positive reaction for neutral mucopolysaccharides but was negative for acid mucopolysaccharides and proteins.

Vasoinhibins regulate the inner and outer blood-retinal barrier and limit retinal oxidative stress.

PubMed

Arredondo Zamarripa, David; Díaz-Lezama, Nundehui; Meléndez García, Rodrigo; Chávez Balderas, Jesús; Adán, Norma; Ledesma-Colunga, Maria G; Arnold, Edith; Clapp, Carmen; Thebault, Stéphanie

2014-01-01

Vasoinhibins are prolactin fragments present in the retina, where they have been shown to prevent the hypervasopermeability associated with diabetes. Enhanced bradykinin (BK) production contributes to the increased transport through the blood-retina barrier (BRB) in diabetes. Here, we studied if vasoinhibins regulate BRB permeability by targeting the vascular endothelium and retinal pigment epithelium (RPE) components of this barrier. Intravitreal injection of BK in male rats increased BRB permeability. Vasoinhibins prevented this effect, as did the B2 receptor antagonist Hoe-140. BK induced a transient decrease in mouse retinal and brain capillary endothelial monolayer resistance that was blocked by vasoinhibins. Both vasoinhibins and the nitric oxide (NO) synthase inhibitor L-NAME, but not the antioxidant N-acetyl cysteine (NAC), blocked the transient decrease in bovine umbilical vein endothelial cell (BUVEC) monolayer resistance induced by BK; this block was reversed by the NO donor DETANONOate. Vasoinhibins also prevented the BK-induced actin cytoskeleton redistribution, as did L-NAME. BK transiently decreased human RPE (ARPE-19) cell monolayer resistance, and this effect was blocked by vasoinhibins, L-NAME, and NAC. DETANONOate reverted the blocking effect of vasoinhibins. Similar to BK, the radical initiator Luperox induced a reduction in ARPE-19 cell monolayer resistance, which was prevented by vasoinhibins. These effects on RPE resistance coincided with actin cytoskeleton redistribution. Intravitreal injection of vasoinhibins reduced the levels of reactive oxygen species (ROS) in retinas of streptozotocin-induced diabetic rats, particularly in the RPE and capillary-containing layers. Thus, vasoinhibins reduce BRB permeability by targeting both its main inner and outer components through NO- and ROS-dependent pathways, offering potential treatment strategies against diabetic retinopathies.

Vasoinhibins regulate the inner and outer blood-retinal barrier and limit retinal oxidative stress

PubMed Central

Arredondo Zamarripa, David; Díaz-Lezama, Nundehui; Meléndez García, Rodrigo; Chávez Balderas, Jesús; Adán, Norma; Ledesma-Colunga, Maria G.; Arnold, Edith; Clapp, Carmen; Thebault, Stéphanie

2014-01-01

Vasoinhibins are prolactin fragments present in the retina, where they have been shown to prevent the hypervasopermeability associated with diabetes. Enhanced bradykinin (BK) production contributes to the increased transport through the blood-retina barrier (BRB) in diabetes. Here, we studied if vasoinhibins regulate BRB permeability by targeting the vascular endothelium and retinal pigment epithelium (RPE) components of this barrier. Intravitreal injection of BK in male rats increased BRB permeability. Vasoinhibins prevented this effect, as did the B2 receptor antagonist Hoe-140. BK induced a transient decrease in mouse retinal and brain capillary endothelial monolayer resistance that was blocked by vasoinhibins. Both vasoinhibins and the nitric oxide (NO) synthase inhibitor L-NAME, but not the antioxidant N-acetyl cysteine (NAC), blocked the transient decrease in bovine umbilical vein endothelial cell (BUVEC) monolayer resistance induced by BK; this block was reversed by the NO donor DETANONOate. Vasoinhibins also prevented the BK-induced actin cytoskeleton redistribution, as did L-NAME. BK transiently decreased human RPE (ARPE-19) cell monolayer resistance, and this effect was blocked by vasoinhibins, L-NAME, and NAC. DETANONOate reverted the blocking effect of vasoinhibins. Similar to BK, the radical initiator Luperox induced a reduction in ARPE-19 cell monolayer resistance, which was prevented by vasoinhibins. These effects on RPE resistance coincided with actin cytoskeleton redistribution. Intravitreal injection of vasoinhibins reduced the levels of reactive oxygen species (ROS) in retinas of streptozotocin-induced diabetic rats, particularly in the RPE and capillary-containing layers. Thus, vasoinhibins reduce BRB permeability by targeting both its main inner and outer components through NO- and ROS-dependent pathways, offering potential treatment strategies against diabetic retinopathies. PMID:25368550

Alumina Paste Sublimation Suppression Barrier for Thermoelectric Device

NASA Technical Reports Server (NTRS)

Caillat, Thierry (Inventor); Paik, Jong-Ah (Inventor)

2014-01-01

Alumina as a sublimation suppression barrier for a Zintl thermoelectric material in a thermoelectric power generation device operating at high temperature, e.g. at or above 1000K, is disclosed. The Zintl thermoelectric material may comprise Yb.sub.14MnSb.sub.11. The alumina may be applied as an adhesive paste dried and cured on a substantially oxide free surface of the Zintl thermoelectric material and polished to a final thickness. The sublimation suppression barrier may be finalized by baking out the alumina layer on the Zintl thermoelectric material until it becomes substantially clogged with ytterbia.

Respiration of metal (hydr)oxides by Shewanella and Geobacter: a key role for multihaem c-type cytochromes

PubMed Central

Shi, Liang; Squier, Thomas C; Zachara, John M; Fredrickson, James K

2007-01-01

Dissimilatory reduction of metal (e.g. Fe, Mn) (hydr)oxides represents a challenge for microorganisms, as their cell envelopes are impermeable to metal (hydr)oxides that are poorly soluble in water. To overcome this physical barrier, the Gram-negative bacteria Shewanella oneidensis MR-1 and Geobacter sulfurreducens have developed electron transfer (ET) strategies that require multihaem c-type cytochromes (c-Cyts). In S. oneidensis MR-1, multihaem c-Cyts CymA and MtrA are believed to transfer electrons from the inner membrane quinone/quinol pool through the periplasm to the outer membrane. The type II secretion system of S. oneidensis MR-1 has been implicated in the reduction of metal (hydr)oxides, most likely by translocating decahaem c-Cyts MtrC and OmcA across outer membrane to the surface of bacterial cells where they form a protein complex. The extracellular MtrC and OmcA can directly reduce solid metal (hydr)oxides. Likewise, outer membrane multihaem c-Cyts OmcE and OmcS of G. sulfurreducens are suggested to transfer electrons from outer membrane to type IV pili that are hypothesized to relay the electrons to solid metal (hydr)oxides. Thus, multihaem c-Cyts play critical roles in S. oneidensis MR-1- and G. sulfurreducens-mediated dissimilatory reduction of solid metal (hydr)oxides by facilitating ET across the bacterial cell envelope. PMID:17581116

The unexpected mechanism underlying the high-valent mono-oxo-rhenium(V) hydride catalyzed hydrosilylation of C=N functionalities: insights from a DFT study.

PubMed

Wang, Jiandi; Wang, Wenmin; Huang, Liangfang; Yang, Xiaodi; Wei, Haiyan

2015-04-07

In this study, we theoretically investigated the mechanism underlying the high-valent mono-oxo-rhenium(V) hydride Re(O)HCl2(PPh3)2 (1) catalyzed hydrosilylation of C=N functionalities. Our results suggest that an ionic S(N)2-Si outer-sphere pathway involving the heterolytic cleavage of the Si-H bond competes with the hydride pathway involving the C=N bond inserted into the Re-H bond for the rhenium hydride (1) catalyzed hydrosilylation of the less steric C=N functionalities (phenylmethanimine, PhCH=NH, and N-phenylbenzylideneimine, PhCH=NPh). The rate-determining free-energy barriers for the ionic outer-sphere pathway are calculated to be ∼28.1 and 27.6 kcal mol(-1), respectively. These values are slightly more favorable than those obtained for the hydride pathway (by ∼1-3 kcal mol(-1)), whereas for the large steric C=N functionality of N,1,1-tri(phenyl)methanimine (PhCPh=NPh), the ionic outer-sphere pathway (33.1 kcal mol(-1)) is more favorable than the hydride pathway by as much as 11.5 kcal mol(-1). Along the ionic outer-sphere pathway, neither the multiply bonded oxo ligand nor the inherent hydride moiety participate in the activation of the Si-H bond. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Underground waste barrier structure

DOEpatents

Saha, Anuj J.; Grant, David C.

1988-01-01

Disclosed is an underground waste barrier structure that consists of waste material, a first container formed of activated carbonaceous material enclosing the waste material, a second container formed of zeolite enclosing the first container, and clay covering the second container. The underground waste barrier structure is constructed by forming a recessed area within the earth, lining the recessed area with a layer of clay, lining the clay with a layer of zeolite, lining the zeolite with a layer of activated carbonaceous material, placing the waste material within the lined recessed area, forming a ceiling over the waste material of a layer of activated carbonaceous material, a layer of zeolite, and a layer of clay, the layers in the ceiling cojoining with the respective layers forming the walls of the structure, and finally, covering the ceiling with earth.

Influence of depressed-index outer ring on evanescent tunneling loss in tapered double-cladding fibers.

PubMed

Chen, Nan-Kuang; Hsu, Kuei-Chu; Liaw, Shien-Kuei; Lai, Yinchieh; Chi, Sien

2008-08-01

A tapered fiber with a depressed-index outer ring is fabricated and dispersion engineered to generate a widely tunable (1250-1650 nm) fundamental-mode leakage loss with a high cutoff slope (-1.2 dB/nm) and a high attenuation for stop band (>50 dB) by modification of both waveguide and material dispersions. The higher cutoff slope is achieved with a larger cross angle between the two refractive index dispersion curves of the tapered fiber and surrounding optical liquids through the use of depressed-index outer ring structures in double-cladding fibers.

Experimental Study on the Interaction Between Contacting Barrier Materials for Containment of Radioactive Wastes

NASA Astrophysics Data System (ADS)

Huang, W. H.; Chang, H. C.

2017-12-01

The disposal of low- and intermediate-level radioactive wastes requires use of multi-barriers for isolation of the wastes from the biosphere. Typically, the engineered barriers are composed of a concrete vault, buffer and backfill materials. Zhishin clay and Black Hill bentonite were used as raw clay material in making buffer and backfill materials in this study. These clays were compacted to make buffer material, or mixed with Taitung area argillite to produce backfill material for potential application as barriers for the disposal of low- and intermediate-level radioactive wastes. The interaction between concrete barrier and the buffer/backfill material is simulated by an accelerated migration test to investigate the effect of contacting concrete on the expected functions of buffer/backfill material. The results show buffer material close to the contact with concrete exhibits significant change in the ratio of calcium/sodium exchange capacity, due to the move of calcium ions released from the concrete. The shorter the distance from the contacting interface, the ratio of the calcium/sodium concentration in buffer/backfill materials increases. The longer the distance from the interface, the effect of the contact on alteration in clays become less significant. Also, some decreases in swelling capacity in the buffer/backfill material near the concrete-backfill interface are noted. Finally, a comparison is made between Zhisin clay and Balck Hill bentonite on the interaction between concrete and the two clays. Black Hill bentonite was found to be influenced more by the interaction, because of the higher content of montmorillonite. On the other hand, being a mixture of clay and sand, backfill material is less affected by the decalsification of concrete at the contact than buffer material.

Barriers to Liposomal Gene Delivery: from Application Site to the Target.

PubMed

Saffari, Mostafa; Moghimi, Hamid Reza; Dass, Crispin R

2016-01-01

Gene therapy is a therapeutic approach to deliver genetic material into cells to alter their function in entire organism. One promising form of gene delivery system (DDS) is liposomes. The success of liposome-mediated gene delivery is a multifactorial issue and well-designed liposomal systems might lead to optimized gene transfection particularly in vivo. Liposomal gene delivery systems face different barriers from their site of application to their target, which is inside the cells. These barriers include presystemic obstacles (epithelial barriers), systemic barriers in blood circulation and cellular barriers. Epithelial barriers differ depending on the route of administration. Systemic barriers include enzymatic degradation, binding and opsonisation. Both of these barriers can act as limiting hurdles that genetic material and their vector should overcome before reaching the cells. Finally liposomes should overcome cellular barriers that include cell entrance, endosomal escape and nuclear uptake. These barriers and their impact on liposomal gene delivery will be discussed in this review.

Restricted ADP movement in cardiomyocytes: Cytosolic diffusion obstacles are complemented with a small number of open mitochondrial voltage-dependent anion channels.

PubMed

Simson, Päivo; Jepihhina, Natalja; Laasmaa, Martin; Peterson, Pearu; Birkedal, Rikke; Vendelin, Marko

2016-08-01

Adequate intracellular energy transfer is crucial for proper cardiac function. In energy starved failing hearts, partial restoration of energy transfer can rescue mechanical performance. There are two types of diffusion obstacles that interfere with energy transfer from mitochondria to ATPases: mitochondrial outer membrane (MOM) with voltage-dependent anion channel (VDAC) permeable to small hydrophilic molecules and cytoplasmatic diffusion barriers grouping ATP-producers and -consumers. So far, there is no method developed to clearly distinguish the contributions of cytoplasmatic barriers and MOM to the overall diffusion restriction. Furthermore, the number of open VDACs in vivo remains unknown. The aim of this work was to establish the partitioning of intracellular diffusion obstacles in cardiomyocytes. We studied the response of mitochondrial oxidative phosphorylation of permeabilized rat cardiomyocytes to changes in extracellular ADP by recording 3D image stacks of NADH autofluorescence. Using cell-specific mathematical models, we determined the permeability of MOM and cytoplasmatic barriers. We found that only ~2% of VDACs are accessible to cytosolic ADP and cytoplasmatic diffusion barriers reduce the apparent diffusion coefficient by 6-10×. In cardiomyocytes, diffusion barriers in the cytoplasm and by the MOM restrict ADP/ATP diffusion to similar extents suggesting a major role of both barriers in energy transfer and other intracellular processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ice chemistry on outer solar system bodies: Carboxylic acids, nitriles, and urea detected in refractory residues produced from the UV photolysis of N{sub 2}:CH{sub 4}:CO-containing ices

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

Materese, Christopher K.; Cruikshank, Dale P.; Sandford, Scott A.

Radiation processing of the surface ices of outer solar system bodies may result in the production of new chemical species even at low temperatures. Many of the smaller, more volatile molecules that are likely produced by the photolysis of these ices have been well characterized by laboratory experiments. However, the more complex refractory material formed in these experiments remains largely uncharacterized. In this work, we present a series of laboratory experiments in which low-temperature (15-20 K) N{sub 2}:CH{sub 4}:CO ices in relative proportions 100:1:1 are subjected to UV irradiation, and the resulting materials are studied with a variety of analyticalmore » techniques including infrared spectroscopy, X-ray absorption near-edge structure spectroscopy, gas chromatography coupled with mass spectrometry, and high-resolution mass spectroscopy. Despite the simplicity of the reactants, these experiments result in the production of a highly complex mixture of molecules from relatively low-mass volatiles (tens of daltons) to high-mass refractory materials (hundreds of daltons). These products include various carboxylic acids, nitriles, and urea, which are also expected to be present on the surface of outer solar system bodies, including Pluto and other transneptunian objects. If these compounds occur in sufficient concentrations in the ices of outer solar system bodies, their characteristic bands may be detectable in the near-infrared spectra of these objects.« less

Structural and Thermodynamic Factors of Suppressed Interdiffusion Kinetics in Multi-component High-entropy Materials

PubMed Central

Chang, Shou-Yi; Li, Chen-En; Huang, Yi-Chung; Hsu, Hsun-Feng; Yeh, Jien-Wei; Lin, Su-Jien

2014-01-01

We report multi-component high-entropy materials as extraordinarily robust diffusion barriers and clarify the highly suppressed interdiffusion kinetics in the multi-component materials from structural and thermodynamic perspectives. The failures of six alloy barriers with different numbers of elements, from unitary Ti to senary TiTaCrZrAlRu, against the interdiffusion of Cu and Si were characterized, and experimental results indicated that, with more elements incorporated, the failure temperature of the barriers increased from 550 to 900°C. The activation energy of Cu diffusion through the alloy barriers was determined to increase from 110 to 163 kJ/mole. Mechanistic analyses suggest that, structurally, severe lattice distortion strains and a high packing density caused by different atom sizes, and, thermodynamically, a strengthened cohesion provide a total increase of 55 kJ/mole in the activation energy of substitutional Cu diffusion, and are believed to be the dominant factors of suppressed interdiffusion kinetics through the multi-component barrier materials. PMID:24561911

Large thermal protection system panel

NASA Technical Reports Server (NTRS)

Weinberg, David J. (Inventor); Myers, Franklin K. (Inventor); Tran, Tu T. (Inventor)

2003-01-01

A protective panel for a reusable launch vehicle provides enhanced moisture protection, simplified maintenance, and increased temperature resistance. The protective panel includes an outer ceramic matrix composite (CMC) panel, and an insulative bag assembly coupled to the outer CMC panel for isolating the launch vehicle from elevated temperatures and moisture. A standoff attachment system attaches the outer CMC panel and the bag assembly to the primary structure of the launch vehicle. The insulative bag assembly includes a foil bag having a first opening shrink fitted to the outer CMC panel such that the first opening and the outer CMC panel form a water tight seal at temperatures below a desired temperature threshold. Fibrous insulation is contained within the foil bag for protecting the launch vehicle from elevated temperatures. The insulative bag assembly further includes a back panel coupled to a second opening of the foil bag such that the fibrous insulation is encapsulated by the back panel, the foil bag, and the outer CMC panel. The use of a CMC material for the outer panel in conjunction with the insulative bag assembly eliminates the need for waterproofing processes, and ultimately allows for more efficient reentry profiles.

Assessing the value of silicone and hydrocolloid products in stoma care.

PubMed

Berry, Jeanette; Black, Pat; Smith, Rory; Stuchfield, Barbara

Intact skin among many other functions provides a protective barrier between the body and its environment, which is critical in regulating transepidermal water loss (Wilkinson and Moor, 1982). The frequent application and removal of adhesives can damage skin by stripping away the outer epidermal layers. Older people, very young children and those with an underlying skin disorder may be particularly at risk (Gibelli et al, 1999; Lyons and Smith, 2003). Hydrocolloid adhesives, which hold moisture in the adhesive mass, are more skin friendly than the acrylic adhesives they now replace and have now become the material of choice for ostomy flanges and flange extenders (Smith et al, 2007). To understand stoma care nurses' awareness of the value of technologically advanced silicone and hydrocolloid products, the authors undertook a nationwide postal survey. The survey, commissioned by four companies in the United Kingdom, who make silicone and hydrocolloid products that can be used in stoma care, were keen to evaluate the awareness of these products to confirm their importance to the patient and why they should be appropriately categorized for reimbursement by the Department of Health.

Preparation and characterization of HA microflowers coating on AZ31 magnesium alloy by micro-arc oxidation and a solution treatment

NASA Astrophysics Data System (ADS)

Tang, Hui; Yu, Dezhen; Luo, Yan; Wang, Fuping

2013-01-01

Magnesium and its alloys are potential biodegradable implant materials due to their attractive biological properties. But the use of magnesium is still hampered by its poor corrosion resistance in physiological fluids. In this work, hydroxyapatite microflowers coating is fabricated by micro-arc oxidation and a solution treatment on AZ31 magnesium alloy. The microstructure and composition are analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). The potentiodynamic polarization and electrochemical impedance spectroscopy are studied in simulated body fluid (SBF) solution, and the apatite-forming ability is studied also. The results show that the corrosion resistance of the magnesium alloy has been enhanced by MAO coating. And the solution treatment can improve the corrosion resistance of the MAO sample, by forming a barrier layer on the surface of the MAO coating, and by penetrating into the outer layer of the MAO film, sealing the micropores and micro-cracks existed in the MAO coating. In addition, the MAO-ST coating also exhibits a high ability to form apatite.

Acoustic Test Results of Melamine Foam with Application to Payload Fairing Acoustic Attenuation Systems

NASA Technical Reports Server (NTRS)

Hughes, William O.; McNelis, Anne M.

2014-01-01

A spacecraft at launch is subjected to a harsh acoustic and vibration environment resulting from the passage of acoustic energy, created during the liftoff of a launch vehicle, through the vehicle's payload fairing. In order to ensure the mission success of the spacecraft it is often necessary to reduce the resulting internal acoustic sound pressure levels through the usage of acoustic attenuation systems. Melamine foam, lining the interior walls of the payload fairing, is often utilized as the main component of such a system. In order to better understand the acoustic properties of melamine foam, with the goal of developing improved acoustic attenuation systems, NASA has recently performed panel level testing on numerous configurations of melamine foam acoustic treatments at the Riverbank Acoustical Laboratory. Parameters assessed included the foam's thickness and density, as well as the effects of a top outer cover sheet material and mass barriers embedded within the foam. This testing followed the ASTM C423 standard for absorption and the ASTM E90 standard for transmission loss. The acoustic test data obtained and subsequent conclusions are the subjects of this paper.

49 CFR 179.220-25 - Stamping.

Code of Federal Regulations, 2010 CFR

2010-10-01

...: Material ASTM A240-316L. Shell thickness Shell 0.167 in. Head thickness Head 0.150 in. Tank builders initials ABC. Date of original test 00-0000. Outer shell: Material ASTM A285-C. Tank builders initials WYZ...

Non-animal models of epithelial barriers (skin, intestine and lung) in research, industrial applications and regulatory toxicology.

PubMed

Gordon, Sarah; Daneshian, Mardas; Bouwstra, Joke; Caloni, Francesca; Constant, Samuel; Davies, Donna E; Dandekar, Gudrun; Guzman, Carlos A; Fabian, Eric; Haltner, Eleonore; Hartung, Thomas; Hasiwa, Nina; Hayden, Patrick; Kandarova, Helena; Khare, Sangeeta; Krug, Harald F; Kneuer, Carsten; Leist, Marcel; Lian, Guoping; Marx, Uwe; Metzger, Marco; Ott, Katharina; Prieto, Pilar; Roberts, Michael S; Roggen, Erwin L; Tralau, Tewes; van den Braak, Claudia; Walles, Heike; Lehr, Claus-Michael

2015-01-01

Models of the outer epithelia of the human body - namely the skin, the intestine and the lung - have found valid applications in both research and industrial settings as attractive alternatives to animal testing. A variety of approaches to model these barriers are currently employed in such fields, ranging from the utilization of ex vivo tissue to reconstructed in vitro models, and further to chip-based technologies, synthetic membrane systems and, of increasing current interest, in silico modeling approaches. An international group of experts in the field of epithelial barriers was convened from academia, industry and regulatory bodies to present both the current state of the art of non-animal models of the skin, intestinal and pulmonary barriers in their various fields of application, and to discuss research-based, industry-driven and regulatory-relevant future directions for both the development of new models and the refinement of existing test methods. Issues of model relevance and preference, validation and standardization, acceptance, and the need for simplicity versus complexity were focal themes of the discussions. The outcomes of workshop presentations and discussions, in relation to both current status and future directions in the utilization and development of epithelial barrier models, are presented by the attending experts in the current report.

49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

Code of Federal Regulations, 2011 CFR

2011-10-01

... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Pt...) At least three specimens of the outer packaging materials must be tested; (2) Each test must be... of cargo compartment lining materials to resist flame penetration with a 2 gallon per hour (GPH) #2...

49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

Code of Federal Regulations, 2012 CFR

2012-10-01

... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Pt...) At least three specimens of the outer packaging materials must be tested; (2) Each test must be... of cargo compartment lining materials to resist flame penetration with a 2 gallon per hour (GPH) #2...

49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

Code of Federal Regulations, 2013 CFR

2013-10-01

... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Pt...) At least three specimens of the outer packaging materials must be tested; (2) Each test must be... of cargo compartment lining materials to resist flame penetration with a 2 gallon per hour (GPH) #2...

49 CFR Appendix E to Part 178 - Flame Penetration Resistance Test

Code of Federal Regulations, 2014 CFR

2014-10-01

... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR PACKAGINGS Pt...) At least three specimens of the outer packaging materials must be tested; (2) Each test must be... of cargo compartment lining materials to resist flame penetration with a 2 gallon per hour (GPH) #2...

Dielectric Barrier Discharge based Mercury-free plasma UV-lamp for efficient water disinfection.

PubMed

Prakash, Ram; Hossain, Afaque M; Pal, U N; Kumar, N; Khairnar, K; Mohan, M Krishna

2017-12-12

A structurally simple dielectric barrier discharge based mercury-free plasma UV-light source has been developed for efficient water disinfection. The source comprises of a dielectric barrier discharge arrangement between two co-axial quartz tubes with an optimized gas gap. The outer electrode is an aluminium baked foil tape arranged in a helical form with optimized pitch, while the inner electrode is a hollow aluminium metallic rod, hermetically sealed. Strong bands peaking at wavelengths 172 nm and 253 nm, along with a weak band peaking at wavelength 265 nm have been simultaneously observed due to plasma radiation from the admixture of xenon and iodine gases. The developed UV source has been used for bacterial deactivation studies using an experimental setup that is an equivalent of the conventional house-hold water purifier system. Deactivation studies for five types of bacteria, i.e., E. coli, Shigella boydii, Vibrio, Coliforms and Fecal coliform have been demonstrated with 4 log reductions in less than ten seconds.

Determination of Urea Permeability in Red Cells by Minimum Method

PubMed Central

Sha'afi, R. I.; Rich, G. T.; Mikulecky, D. C.; Solomon, A. K.

1970-01-01

A new method has been developed for measuring the permeability coefficient, ω, of small nonelectrolytes. The method depends upon a mathematical analysis of the time course of cell volume changes in the neighborhood of the minimum volume following addition of a permeating solute to an isosmolal buffer. Coefficients determined by the minimum volume method agree with those obtained using radioactive tracers. ω for urea in human red cells was found to decrease as the volume flow, Jv, into the cell increased. Such behavior is entirely unexpected for a single uniform rate-limiting barrier on the basis of the linear phenomenological equations derived from irreversible thermodynamics. However, the present findings are consonant with a complex membrane system consisting of a tight barrier on the outer face of the human red cell membrane and a somewhat less restrictive barrier behind it closer to the inner membrane face. A theoretical analysis of such a series model has been made which makes predictions consistent with the experimental findings. PMID:5435779

Degradation of Hubble Space Telescope Metallized Teflon(trademark) FEP Thermal Control Materials

NASA Technical Reports Server (NTRS)

Hansen, Patricia A.; Townsend, Jacqueline A.; Yoshikawa, Yukio; Castro, J. David; Triolo, Jack J.; Peters, Wanda C.

1998-01-01

The mechanical and optical properties of the metallized Teflon Fluorinated Ethylene Propylene (FEP) thermal control materials on the Hubble Space Telescope (HST) have degraded over the seven years the telescope has been in orbit. Astronaut observations and photographic documentation from the Second Servicing Mission revealed severe cracks of the multi-layer insulation (MLI) blanket outer layer in many locations around the telescope, particularly on solar facing surfaces. Two samples, the outer Teflon FEP MLI layer and radiator surfaces, were characterized post- mission through exhaustive mechanical, thermal, chemical, and optical testing. The observed damage to the thermal control materials, the sample retrieval and handling, and the significant changes to the radiator surfaces of HST will be discussed. Each of these issues is addressed with respect to current and future mission requirements.

Influence of polydimethylsiloxane outer coating and packing material on analyte recovery in dual-phase headspace sorptive extraction.

PubMed

Bicchi, Carlo; Cordero, Chiara; Liberto, Erica; Sgorbini, Barbara; David, Frank; Sandra, Pat; Rubiolo, Patrizia

2007-09-14

Dual phase twisters (DP twisters), consisting of a polydimethylsiloxane (PDMS) outer coating and a second complementary (ad)sorbent as inner packing, have recently been shown to extend the applicability of headspace sorptive extraction (HSSE). In comparison to HSSE using PDMS only, the recovery of analytes from the headspace of a solid or liquid matrix is increased by combining the concentration capabilities of two sampling materials operating on different mechanisms (sorption and adsorption). This study compares the performance of DP twisters consisting of different PDMS outer coatings and different packing materials, including Tenax GC, a bisphenol-PDMS copolymer, Carbopack coated with 5% of Carbowax and beta-cyclodextrin, for the analysis of the headspace of roasted Arabica coffee, dried sage leaves and an aqueous test mixture containing compounds with different water solubility, acidity, polarity and volatility as test samples. In general, DP twisters showed a higher concentration capability than the corresponding conventional PDMS twisters for the analytes considered. The highest recoveries were obtained with DP twisters consisting of 0.2mm thick PDMS coating combined with Tenax GC, a bisphenol-PDMS copolymer and Carbopack coated with 5% of Carbowax as inner adsorption phase.

CORNER OF SUBPILE ROOM: NORTH AND EAST SIDES. STEEL OUTER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CORNER OF SUBPILE ROOM: NORTH AND EAST SIDES. STEEL OUTER SHELL HAS BEEN AFFIXED. SIGN SAYS "HERRICK IRON WORKS STEEL, OAKLAND, CALIFORNIA." NOTE CONDUIT FOR FUTURE INSTRUMENTATION. TOP OF STEEL CASE WILL BE LEVEL WITH BASEMENT CEILING. CAMERA FACES SOUTHEAST. INL NEGATIVE NO. 734. Unknown Photographer, 10/6/1950 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Water and Volatiles in the Outer Solar System

NASA Astrophysics Data System (ADS)

Grasset, O.; Castillo-Rogez, J.; Guillot, T.; Fletcher, L. N.; Tosi, F.

2017-10-01

Space exploration and ground-based observations have provided outstanding evidence of the diversity and the complexity of the outer solar system. This work presents our current understanding of the nature and distribution of water and water-rich materials from the water snow line to the Kuiper Belt. This synthesis is timely, since a thorough exploration of at least one object in each region of the outer solar system has now been achieved. Next steps, starting with the Juno mission now in orbit around Jupiter, will be more focused on understanding the processes at work than on describing the general characteristics of each giant planet systems. This review is organized in three parts. First, the nature and the distribution of water and volatiles in giant and intermediary planets are described from their inner core to their outer envelopes. A special focus is given to Jupiter and Saturn, which are much better understood than the two ice giants (Uranus and Neptune) thanks to the Galileo and Cassini missions. Second, the icy moons will be discussed. Space missions and ground-based observations have revealed the variety of icy surfaces in the outer system. While Europa, Enceladus, and maybe Titan present past or even active tectonic and volcanic activities, many other moons have been dead worlds for more than 3 billion years. Ice compositions found at these bodies are also complex and it is now commonly admitted that icy surfaces are never composed of pure ices. A detailed review of the distribution of non-ice materials on the surfaces and in the tenuous atmospheres of the moons is proposed, followed by a more focused discussion on the nature and the characteristics of the liquid layers trapped below the cold icy crusts that have been suggested in the icy Galilean moons, and in Enceladus, Dione, and Titan at Saturn. Finally, the recent observations collected by Dawn at Ceres and New Horizons at Pluto, as well as the state of knowledge of other transneptunian objects, are summarized, and complete this overview of the nature and distribution of ice-rich material in the outer solar system.

Ethylene vinyl alcohol: a review of barrier properties for packaging shelf stable foods.

PubMed

Mokwena, K Khanah; Tang, Juming

2012-01-01

Ethylene vinyl alcohol (EVOH) is one of the best known flexible thermoplastic oxygen barrier materials in use today. It is especially important for refrigerated and shelf-stable foods where oxygen deteriorates the quality of packaged products and reduces their shelf life. EVOH accounts for a majority of thermoplastic barrier materials used for rigid or semi-rigid retortable food containers. However. it is of limited use in flexible packages or lid films for rigid trays used for packaging thermally processed shelf-stable low acid foods due to its moisture sensitivity. Nevertheless, current use of other oxygen barrier materials such as polyvinylidene chloride and aluminum foil creates environmental concerns. Innovations in food processing technologies provide opportunities for increased use of EVOH in food packaging. The aim of this review is to give an overview of research on the oxygen barrier properties of EVOH from the perspective of structure-barrier property relationships and the consequences of food processing conditions.

Method of Suppressing Sublimation in Advanced Thermoelectric Devices

NASA Technical Reports Server (NTRS)

Sakamoto, Jeffrey S. (Inventor); Caillat, Thierry (Inventor); Fleurial, Jean-Pierre (Inventor); Snyder, G. Jeffrey (Inventor)

2009-01-01

A method of applying a physical barrier to suppress thermal decomposition near a surface of a thermoelectric material including applying a continuous metal foil to a predetermined portion of the surface of the thermoelectric material, physically binding the continuous metal foil to the surface of the thermoelectric material using a binding member, and heating in a predetermined atmosphere the applied and physically bound continuous metal foil and the thermoelectric material to a sufficient temperature in order to promote bonding between the continuous metal foil and the surface of the thermoelectric material. The continuous metal foil forms a physical barrier to enclose a predetermined portion of the surface. Thermal decomposition is suppressed at the surface of the thermoelectric material enclosed by the physical barrier when the thermoelectric element is in operation.

Coastal Environment, Bathymetry and Physical Oceanography along the Beaufort, Chukchi and Bering Seas.

DTIC Science & Technology

1980-01-01

Unit No. 347 , Vol. III, Chukchi-Beaufort Sea, 409 pp. 3. Hopkins, D.M. and R.W. Hartz, 1978, Coastal morphology, coastal erosion, and barrier islands of...U.S. Department of Commerce, Alaska Outer Continental Shelf Environmental Assessment Program Final Report, Research Unit No. 347 , vol. III, Chukchi...Assessment Program Final Report, Research Univ No. 347 , vol. II, Bering Sea, 443 pp. 3. U.S. Department of Commerce, 1964, Pacific and Arctic Coasts

AGARD Corrosion Handbook. Volume 1. Aircraft Corrosion: Causes and Case Histories

DTIC Science & Technology

1985-07-01

Anodic coatings can be formed in chromic acid, sulphuric acid, phosphoric acid or oxalic acid solutions. Chromic acid anodizing is widely used with...and consists of a thin non-porous barrier layer next to the metal with a porous outer layer that can be sealed by hydrothermal treatment in steam...anaerobic) or an oxidative (aerobic) mechanism. Various organic acids such as citric acid, oxalic acid, gluconic acid, dodecanoic acid, etc., which may be

Negative Charge Neutralization in the Loops and Turns of Outer Membrane Phospholipase A Impacts Folding Hysteresis at Neutral pH.

PubMed

McDonald, Sarah K; Fleming, Karen G

2016-11-08

Hysteresis in equilibrium protein folding titrations is an experimental barrier that must be overcome to extract meaningful thermodynamic quantities. Traditional approaches to solving this problem involve testing a spectrum of solution conditions to find ones that achieve path independence. Through this procedure, a specific pH of 3.8 was required to achieve path independence for the water-to-bilayer equilibrium folding of outer membrane protein OmpLA. We hypothesized that the neutralization of negatively charged side chains (Asp and Glu) at pH 3.8 could be the physical basis for path-independent folding at this pH. To test this idea, we engineered variants of OmpLA with Asp → Asn and Glu → Gln mutations to neutralize the negative charges within various regions of the protein and tested for reversible folding at neutral pH. Although not fully resolved, our results show that these mutations in the periplasmic turns and extracellular loops are responsible for 60% of the hysteresis in wild-type folding. Overall, our study suggests that negative charges impact the folding hysteresis in outer membrane proteins and their neutralization may aid in protein engineering applications.

Porins Increase Copper Susceptibility of Mycobacterium tuberculosis

PubMed Central

Speer, Alexander; Rowland, Jennifer L.; Haeili, Mehri; Niederweis, Michael

2013-01-01

Copper resistance mechanisms are crucial for many pathogenic bacteria, including Mycobacterium tuberculosis, during infection because the innate immune system utilizes copper ions to kill bacterial intruders. Despite several studies detailing responses of mycobacteria to copper, the pathways by which copper ions cross the mycobacterial cell envelope are unknown. Deletion of porin genes in Mycobacterium smegmatis leads to a severe growth defect on trace copper medium but simultaneously increases tolerance for copper at elevated concentrations, indicating that porins mediate copper uptake across the outer membrane. Heterologous expression of the mycobacterial porin gene mspA reduced growth of M. tuberculosis in the presence of 2.5 μM copper by 40% and completely suppressed growth at 15 μM copper, while wild-type M. tuberculosis reached its normal cell density at that copper concentration. Moreover, the polyamine spermine, a known inhibitor of porin activity in Gram-negative bacteria, enhanced tolerance of M. tuberculosis for copper, suggesting that copper ions utilize endogenous outer membrane channel proteins of M. tuberculosis to gain access to interior cellular compartments. In summary, these findings highlight the outer membrane as the first barrier against copper ions and the role of porins in mediating copper uptake in M. smegmatis and M. tuberculosis. PMID:24013632

Antibacterial Activity of a Novel Peptide-Modified Lysin Against Acinetobacter baumannii and Pseudomonas aeruginosa

PubMed Central

Yang, Hang; Wang, Mengyue; Yu, Junping; Wei, Hongping

2015-01-01

The global emergence of multidrug-resistant (MDR) bacteria is a growing threat to public health worldwide. Natural bacteriophage lysins are promising alternatives in the treatment of infections caused by Gram-positive pathogens, but not Gram-negative ones, like Acinetobacter baumannii and Pseudomonas aeruginosa, due to the barriers posed by their outer membranes. Recently, modifying a natural lysin with an antimicrobial peptide was found able to break the barriers, and to kill Gram-negative pathogens. Herein, a new peptide-modified lysin (PlyA) was constructed by fusing the cecropin A peptide residues 1–8 (KWKLFKKI) with the OBPgp279 lysin and its antibacterial activity was studied. PlyA showed good and broad antibacterial activities against logarithmic phase A. baumannii and P. aeruginosa, but much reduced activities against the cells in stationary phase. Addition of outer membrane permeabilizers (EDTA and citric acid) could enhance the antibacterial activity of PlyA against stationary phase cells. Finally, no antibacterial activity of PlyA could be observed in some bio-matrices, such as culture media, milk, and sera. In conclusion, we reported here a novel peptide-modified lysin with significant antibacterial activity against both logarithmic (without OMPs) and stationary phase (with OMPs) A. baumannii and P. aeruginosa cells in buffer, but further optimization is needed to achieve broad activity in diverse bio-matrices. PMID:26733995

Controlled modulation of hard and soft X-ray induced tunneling currents utilizing coaxial metal-insulator-metal probe tips

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

Cummings, Marvin; Shirato, Nozomi; Kersell, Heath

Here, the effect of a local external electric field on the barrier potential of a tunneling gap is studied utilizing an emerging technique, synchrotron x-ray scanning tunneling microscopy. Here, we demonstrate that the shape of the potential barrier in the tunneling gap can be altered by a localized external electric field, generated by voltages placed on the metallic outer shield of a nanofabricated coaxial metal-insulator-metal tip, resulting in a controlled linear modulation of the tunneling current. Experiments at hard and soft x-ray synchrotron beamlines reveal that both the chemical contrast and magnetic contrast signals measured by the tip can bemore » drastically enhanced, resulting in improved local detection of chemistry and magnetization at the surface.« less

Controlled modulation of hard and soft X-ray induced tunneling currents utilizing coaxial metal-insulator-metal probe tips

DOE PAGES

Cummings, Marvin; Shirato, Nozomi; Kersell, Heath; ...

2017-01-05

Here, the effect of a local external electric field on the barrier potential of a tunneling gap is studied utilizing an emerging technique, synchrotron x-ray scanning tunneling microscopy. Here, we demonstrate that the shape of the potential barrier in the tunneling gap can be altered by a localized external electric field, generated by voltages placed on the metallic outer shield of a nanofabricated coaxial metal-insulator-metal tip, resulting in a controlled linear modulation of the tunneling current. Experiments at hard and soft x-ray synchrotron beamlines reveal that both the chemical contrast and magnetic contrast signals measured by the tip can bemore » drastically enhanced, resulting in improved local detection of chemistry and magnetization at the surface.« less

Evolution of space food in Nostoc sp. HK-01

NASA Astrophysics Data System (ADS)

Tomita-Yokotani, Kaori; Yamashita, Masamichi; Hashimoto, Hirofumi; Sato, Seigo; Kimura, Yasuko; Katoh, Hiroshi; Arai, Mayumi

2012-07-01

Habitation in outer space is one of our challenges. We have been studying future space agriculture to provide food and oxygen for the habitation area in the space environment, on Mars. A cyanobacteria, Nostoc sp. HK-01, has high several outer space environmental tolerance. We have already confirmed that Nostoc sp.HK-01 had an ability to grow for over several years on the Martian regolith simulant in a laboratory experiment. Nostoc sp HK-01 would have high contribution to change the atmosphere in Mars as a photosynthetic creature. In outer environment, all of materials have to circulate for all of creature living in artificial eco-systems on Mars. This material has several functions as the utilization in space agriculture. Here, we are proposing using them as a food after its growing on Mars. We are trying to determine the best conditions and evolution for space food using Nostoc sp.HK-01 and studying the proposal of utilization of cyanobacteria, Nostoc sp HK-01, for the variation of meal as space agriculture.

A Distant Solar System Artist Concept

NASA Image and Video Library

2004-12-09

This artist concept depicts a distant hypothetical solar system, similar in age to our own. Looking inward from the system outer fringes, a ring of dusty debris can be seen, and within it, planets circling a star the size of our Sun. This debris is all that remains of the planet-forming disk from which the planets evolved. Planets are formed when dusty material in a large disk surrounding a young star clumps together. Leftover material is eventually blown out by solar wind or pushed out by gravitational interactions with planets. Billions of years later, only an outer disk of debris remains. These outer debris disks are too faint to be imaged by visible-light telescopes. They are washed out by the glare of the Sun. However, NASA's Spitzer Space Telescope can detect their heat, or excess thermal emission, in infrared light. This allows astronomers to study the aftermath of planet building in distant solar systems like our own. http://photojournal.jpl.nasa.gov/catalog/PIA07096

Explosion containment device

DOEpatents

Benedick, William B.; Daniel, Charles J.

1977-01-01

The disclosure relates to an explosives storage container for absorbing and containing the blast, fragments and detonation products from a possible detonation of a contained explosive. The container comprises a layer of distended material having sufficient thickness to convert a portion of the kinetic energy of the explosion into thermal energy therein. A continuous wall of steel sufficiently thick to absorb most of the remaining kinetic energy by stretching and expanding, thereby reducing the momentum of detonation products and high velocity fragments, surrounds the layer of distended material. A crushable layer surrounds the continuous steel wall and accommodates the stretching and expanding thereof, transmitting a moderate load to the outer enclosure. These layers reduce the forces of the explosion and the momentum of the products thereof to zero. The outer enclosure comprises a continuous pressure wall enclosing all of the layers. In one embodiment, detonation of the contained explosive causes the outer enclosure to expand which indicates to a visual observer that a detonation has occurred.

Spontaneous Fission Barriers Based on a Generalized Liquid Drop Model

NASA Astrophysics Data System (ADS)

Guo, Shu-Qing; Bao, Xiao-Jun; Li, Jun-Qing; Zhang, Hong-Fei

2014-05-01

The barrier against the spontaneous fission has been determined within the Generalized Liquid Drop Model (GLDM) including the mass and charge asymmetry, and the proximity energy. The shell correction of the spherical parent nucleus is calculated by using the Strutinsky method, and the empirical shape-dependent shell correction is employed during the deformation process. A quasi-molecular shape sequence has been defined to describe the whole process from one-body shape to two-body shape system, and a two-touching-ellipsoid is adopted when the superdeformed one-body system reaches the rupture point. On these bases the spontaneous fission barriers are systematically studied for nuclei from 230Th to 249Cm for different possible exiting channels with the different mass and charge asymmetries. The double, and triple bumps are found in the fission potential energy in this region, which roughly agree with the experimental results. It is found that at around Sn-like fragment the outer fission barriers are lower, while the partner of the Sn-like fragment is in the range near 108Ru where the ground-state mass is lowered by allowing axially symmetric shapes. The preferable fission channels are distinctly pronounced, which should be corresponding to the fragment mass distributions.

Application of diffusion barriers to high modulus fibers

NASA Technical Reports Server (NTRS)

Veltri, R. D.; Douglas, F. C.; Paradis, E. L.; Galasso, F. S.

1977-01-01

Barrier layers were coated onto high-modulus fibers, and nickel and titanium layers were overcoated as simulated matrix materials. The objective was to coat the high-strength fibers with unreactive selected materials without degrading the fibers. The fibers were tungsten, niobium, and single-crystal sapphire, while the materials used as barrier coating layers were Al2O3, Y2O3, TiC, ZrC, WC with 14% Co, and HfO2. An ion-plating technique was used to coat the fibers. The fibers were subjected to high-temperature heat treatments to evaluate the effectiveness of the barrier layer in preventing fiber-metal interactions. Results indicate that Al2O3, Y2O3, and HfO2 can be used as barrier layers to minimize the nickel-tungsten interaction. Further investigation, including thermal cycling tests at 1090 C, revealed that HfO2 is probably the best of the three.

Vapor-barrier Vacuum Isolation System

NASA Technical Reports Server (NTRS)

Weinstein, Leonard M. (Inventor); Taminger, Karen M. (Inventor)

2014-01-01

A system includes a collimated beam source within a vacuum chamber, a condensable barrier gas, cooling material, a pump, and isolation chambers cooled by the cooling material to condense the barrier gas. Pressure levels of each isolation chamber are substantially greater than in the vacuum chamber. Coaxially-aligned orifices connect a working chamber, the isolation chambers, and the vacuum chamber. The pump evacuates uncondensed barrier gas. The barrier gas blocks entry of atmospheric vapor from the working chamber into the isolation chambers, and undergoes supersonic flow expansion upon entering each isolation chamber. A method includes connecting the isolation chambers to the vacuum chamber, directing vapor to a boundary with the working chamber, and supersonically expanding the vapor as it enters the isolation chambers via the orifices. The vapor condenses in each isolation chamber using the cooling material, and uncondensed vapor is pumped out of the isolation chambers via the pump.

Quercetin and isorhamnetin glycosides in onion (Allium cepa L.): varietal comparison, physical distribution, coproduct evaluation, and long-term storage stability.

PubMed

Lee, Jihyun; Mitchell, Alyson E

2011-02-09

During onion processing, the outer dried protective layer (outer paper layer) and first two fleshy leaf layers are removed. This coproduct material is a potential commercial source of flavonoids especially quercetin. In the following study, the flavonoid composition was determined in coproduct materials and the press cake (material generated after juice extraction) in several commercially important onion varieties grown in California. Flavonoids were characterized and quantified using LC-(ESI)MS/MS and HPLC. The long-term stability of quercetin glycosides was assessed in dried coproduct materials stored at 4 and 22 °C over a 12 month period. In all varieties, the predominant forms of quercetin were the quercetin 3,4'-O-glucoside and 4'-O-glucoside. The first layer had significantly higher levels of flavonoids than the outer paper, second, and inner flesh layers on a DW basis (p < 0.05). Allium cepa "Milestone" contained the highest levels (p < 0.05) of flavonoids (1703 mg/100 g on a dry weight basis (DW). Onion press cake had significantly higher levels of total quercetin as compared with fresh onions (p < 0.05). The levels of 4'-O-glucoside significantly decreased during the first month of storage and remained stable for 12 months of storage at either 4 or 22 °C (p < 0.05).

Intraperitoneal adhesions--an ongoing challenge between biomedical engineering and the life sciences.

PubMed

Brochhausen, Christoph; Schmitt, Volker H; Rajab, Taufiek K; Planck, Constanze N E; Krämer, Bernhard; Wallwiener, Markus; Hierlemann, Helmut; Kirkpatrick, C James

2011-07-01

Peritoneal adhesions remain a relevant clinical problem despite the currently available prophylactic barrier materials. So far, the physical separation of traumatized serosa areas using barriers represents the most important clinical strategy for adhesion prevention. However, the optimal material has not yet been found. Further optimization or pharmacological functionalization of these barriers could give an innovative input for peritoneal adhesion prevention. Therefore, a more complete understanding of pathogenesis is required. On the basis of the pathophysiology of adhesion formation the main barriers currently in clinical practice as well as new innovations are discussed in the present review. Physiologically, mesothelial cells play a decisive role in providing a frictionless gliding surface on the serosa. Adhesion formation results from a cascade of events and is regulated by a variety of cellular and humoral factors. The main clinically applied strategy for adhesion prevention is based on the use of liquid or solid adhesion barriers to separate physically any denuded tissue. Both animal and human trials have not yet been able to identify the optimal barrier to prevent adhesion formation in a sustainable way. Therefore, further developments are required for effective prevention of postoperative adhesion formation. To reach this goal the combination of structural modification and pharmacological functionalization of barrier materials should be addressed. Achieving this aim requires the interaction between basic research, materials science and clinical expertise. Copyright © 2011 Wiley Periodicals, Inc.

49 CFR 587.5 - Incorporated materials.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) DEFORMABLE BARRIERS Side Impact Moving Deformable Barrier § 587.5 Incorporated materials. (a) The drawings and specifications referred to in this regulation...

Method of controlling the side wall thickness of a turbine nozzle segment for improved cooling

DOEpatents

Burdgick, Steven Sebastian

2002-01-01

A gas turbine nozzle segment has outer and inner bands and a vane extending therebetween. Each band has a side wall, a cover and an impingement plate between the cover and nozzle wall defining two cavities on opposite sides of the impingement plate. Cooling steam is supplied to one cavity for flow through apertures of the impingement plate to cool the nozzle wall. The side wall of the band has an inturned flange defining with the nozzle wall an undercut region. The outer surface of the side wall is provided with a step prior to welding the cover to the side wall. A thermal barrier coating is applied in the step and, after the cover is welded to the side wall, the side wall is finally machined to a controlled thickness removing all, some or none of the coating.

[Healthy eating according to teenagers: perceptions, barriers, and expected characteristics of teaching materials].

PubMed

Toral, Natacha; Conti, Maria Aparecida; Slater, Betzabeth

2009-11-01

The aim of this study was to evaluate perceptions, barriers, and characteristics of teaching materials to promote healthy eating, as described by teenagers. Four focus groups were conducted with 25 adolescents, including questions on: perceptions regarding diet and motivations to change; concepts of (and barriers to) healthy eating; and characteristics needed for teaching materials to promote healthy eating. The teens were often undecided when attempting to classify a diet as healthy. They generally reported feeling insecure about making dietary changes, but showed adequate notions of healthy eating. The main barriers involved personal and social characteristics: temptation, food flavors, parental influence, and lack of time and options for healthy snacks at school. According to these teenagers, educational materials for promotion of healthy eating should emphasize the immediate benefits and emphasize high-impact messages on the health risks of unhealthy diet.

Device and method for producing a containment barrier underneath and around in-situ buried waste

DOEpatents

Gardner, Bradley M.; Smith, Ann M.; Hanson, Richard W.; Hodges, Richard T.

1998-01-01

An apparatus for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably on which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment.

Underground barrier construction apparatus with soil-retaining shield

DOEpatents

Gardner, Bradley M.; Smith, Ann Marie; Hanson, Richard W.; Hodges, Richard T.

1998-01-01

An apparatus for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably one which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground, a shield means for maintaining the void, and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment.

Gut barrier in health and disease: focus on childhood.

PubMed

Viggiano, D; Ianiro, G; Vanella, G; Bibbò, S; Bruno, G; Simeone, G; Mele, G

2015-01-01

The gut barrier is a functional unit, organized as a multi-layer system, made up of two main components: a physical barrier surface, which prevents bacterial adhesion and regulates paracellular diffusion to the host tissues, and a deep functional barrier, that is able to discriminate between pathogens and commensal microorganisms, organizing the immune tolerance and the immune response to pathogens. Other mechanisms, such as gastric juice and pancreatic enzymes (which both have antibacterial properties) participate in the luminal integrity of the gut barrier. From the outer layer to the inner layer, the physical barrier is composed of gut microbiota (that competes with pathogens to gain space and energy resources, processes the molecules necessary to mucosal integrity and modulates the immunological activity of deep barrier), mucus (which separates the intraluminal content from more internal layers and contains antimicrobial products and secretory IgA), epithelial cells (which form a physical and immunological barrier) and the innate and adaptive immune cells forming the gut-associated lymphoid tissue (which is responsible for antigen sampling and immune responses). Disruption of the gut barrier has been associated with many gastrointestinal diseases, but also with extra-intestinal pathological condition, such as type 1 diabetes mellitus, allergic diseases or autism spectrum disorders. The maintenance of a healthy intestinal barrier is therefore of paramount importance in children, for both health and economic reasons. Many drugs or compounds used in the treatment of gastrointestinal disorders act through the restoration of a normal intestinal permeability. Several studies have highlighted the role of probiotics in the modulation and reduction of intestinal permeability, considering the strong influence of gut microbiota in the modulation of the function and structure of gut barrier, but also on the immune response of the host. To date, available weapons for the maintenance and repair of gut barrier are however few, even if promising. Considerable efforts, including both a better understanding of the gut barrier features and mechanisms in health and disease, and the development of new pharmacological approaches for the modulation of gut barrier components, are needed for the prevention and treatment of gastrointestinal and extraintestinal diseases associated with gut barrier impairment.

Cooking utensil with improved heat retention

DOEpatents

Potter, Thomas F.; Benson, David K.; Burch, Steven D.

1997-01-01

A cooking utensil with improved heat retention includes an inner pot received within an outer pot and separated in a closely spaced-apart relationship to form a volume or chamber therebetween. The chamber is evacuated and sealed with foil leaves at the upper edges of the inner and outer pot. The vacuum created between the inner and outer pot, along with the minimum of thermal contact between the inner and outer pot, and the reduced radiative heat transfer due to low emissivity coatings on the inner and outer pot, provide for a highly insulated cooking utensil. Any combination of a plurality of mechanisms for selectively disabling and re-enabling the insulating properties of the pot are provided within the chamber. These mechanisms may include: a hydrogen gas producing and reabsorbing device such as a metal hydride, a plurality of metal contacts which can be adjusted to bridge the gap between the inner and outer pot, and a plurality of bimetallic switches which can selectively bridge the gap between the inner and outer pot. In addition, phase change materials with superior heat retention characteristics may be provided within the cooking utensil. Further, automatic and programmable control of the cooking utensil can be provided through a microprocessor and associated hardware for controlling the vacuum disable/enable mechanisms to automatically cook and save food.

Cooking utensil with improved heat retention

DOEpatents

Potter, T.F.; Benson, D.K.; Burch, S.D.

1997-07-01

A cooking utensil with improved heat retention includes an inner pot received within an outer pot and separated in a closely spaced-apart relationship to form a volume or chamber there between. The chamber is evacuated and sealed with foil leaves at the upper edges of the inner and outer pot. The vacuum created between the inner and outer pot, along with the minimum of thermal contact between the inner and outer pot, and the reduced radiative heat transfer due to low emissivity coatings on the inner and outer pot, provide for a highly insulated cooking utensil. Any combination of a plurality of mechanisms for selectively disabling and re-enabling the insulating properties of the pot are provided within the chamber. These mechanisms may include: a hydrogen gas producing and reabsorbing device such as a metal hydride, a plurality of metal contacts which can be adjusted to bridge the gap between the inner and outer pot, and a plurality of bimetallic switches which can selectively bridge the gap between the inner and outer pot. In addition, phase change materials with superior heat retention characteristics may be provided within the cooking utensil. Further, automatic and programmable control of the cooking utensil can be provided through a microprocessor and associated hardware for controlling the vacuum disable/enable mechanisms to automatically cook and save food. 26 figs.

Comparison of comet 81P/Wild 2 dust with interplanetary dust from comets.

PubMed

Ishii, Hope A; Bradley, John P; Dai, Zu Rong; Chi, Miaofang; Kearsley, Anton T; Burchell, Mark J; Browning, Nigel D; Molster, Frank

2008-01-25

The Stardust mission returned the first sample of a known outer solar system body, comet 81P/Wild 2, to Earth. The sample was expected to resemble chondritic porous interplanetary dust particles because many, and possibly all, such particles are derived from comets. Here, we report that the most abundant and most recognizable silicate materials in chondritic porous interplanetary dust particles appear to be absent from the returned sample, indicating that indigenous outer nebula material is probably rare in 81P/Wild 2. Instead, the sample resembles chondritic meteorites from the asteroid belt, composed mostly of inner solar nebula materials. This surprising finding emphasizes the petrogenetic continuum between comets and asteroids and elevates the astrophysical importance of stratospheric chondritic porous interplanetary dust particles as a precious source of the most cosmically primitive astromaterials.

Cell and current collector felt arrangement for solid oxide electrochemical cell combinations

DOEpatents

Reichner, Philip

1988-01-01

A solid electrolyte electrochemical cell combination 1 is made, comprising an annular, axially elongated, inner electrode 2 containing at least one interior gas feed conduit 3; annular solid electrolyte segments 4 around and covering portions of the inner electrode; annular outer electrode segments 6 around and covering portions of the electrolyte segments; electronically conducting, non-porous, interconnection material 5 disposed between electrolyte segments and in contact with the inner electrode, and electronically conducting, porous, metal fiber current collector felts 7 disposed on top of the non-porous interconnect material and outer electrode segments, where both the non-porous interconnect material and the porous metal felts are disposed circumferentially about the cell, transversely to the axial length of the cell and the inner electrode is continuous for the entire axial length of the cell combination.

BIFUNCTIONAL ALUMINUN: A PERMEABLE BARRIER MATERIAL FOR THE DEGRADATION OF MTBE

EPA Science Inventory

Bifunctional aluminum is an innovative remedial material for the treatment of gasoline oxygenates in permeable reactive barriers (PRBs). PRBs represent a promising environmental technology for remediation of groundwater contamination. Although zero-valent metals (ZVM) have been...

Silicon oxide permeation barrier coating of PET bottles and foils

NASA Astrophysics Data System (ADS)

Steves, Simon; Deilmann, Michael; Awakowicz, Peter

2009-10-01

Modern packaging materials such as polyethylene terephthalate (PET) have displaced established materials in many areas of food and beverage packaging. Plastic packing materials offer are various advantages concerning production and handling. PET bottles for instance are non-breakable and lightweight compared to glass and metal containers. However, PET offers poor barrier properties against gas permeation. Therefore, the shelf live of packaged food is reduced. Permeation of gases can be reduced by depositing transparent plasma polymerized silicon oxide (SiOx) barrier coatings. A microwave (2.45 GHz) driven low pressure plasma reactor is developed based on a modified Plasmaline antenna to treat PET foils or bottles. To increase the barrier properties of the coatings furthermore a RF substrate bias (13.56 MHz) is applied. The composition of the coatings is analyzed by means of Fourier transform infrared (FTIR) spectroscopy regarding carbon and hydrogen content. Influence of gas phase composition and substrate bias on chemical composition of the coatings is discussed. A strong relation between barrier properties and film composition is found: good oxygen barriers are observed as carbon content is reduced and films become quartz-like. Regarding oxygen permeation a barrier improvement factor (BIF) of 70 is achieved.

Electronic Devices with Diffusion Barrier and Process for Making Same

DTIC Science & Technology

2001-05-09

conductivity metallization materials such as gold , silver, and platinum. As can be appreciated from the foregoing, a barrier film is needed which... gold ), as well as platinum. These metals are highly attractive 10 for interconnect strategies on account of there intrinsic low resistivity and...the monolayer portion of the barrier -7- material. The monolayer ( monoatomic ) layer of metal atoms and the homoepitaxial film of metal halide

Encapsulation of organic light emitting diodes

NASA Astrophysics Data System (ADS)

Visweswaran, Bhadri

Organic Light Emitting Diodes (OLEDs) are extremely attractive candidates for flexible display and lighting panels due to their high contrast ratio, light weight and flexible nature. However, the materials in an OLED get oxidized by extremely small quantities of atmospheric moisture and oxygen. To obtain a flexible OLED device, a flexible thin-film barrier encapsulation with low permeability for water is necessary. Water permeates through a thin-film barrier by 4 modes: microcracks, contaminant particles, along interfaces, and through the bulk of the material. We have developed a flexible barrier film made by Plasma Enhanced Chemical Vapor Deposition (PECVD) that is devoid of any microcracks. In this work we have systematically reduced the permeation from the other three modes to come up with a barrier film design for an operating lifetime of over 10 years. To provide quantitative feedback during barrier material development, techniques for measuring low diffusion coefficient and solubility of water in a barrier material have been developed. The mechanism of water diffusion in the barrier has been identified. From the measurements, we have created a model for predicting the operating lifetime from accelerated tests when the lifetime is limited by bulk diffusion. To prevent the particle induced water permeation, we have encapsulated artificial particles and have studied their cross section. A three layer thin-film that can coat a particle at thicknesses smaller than the particle diameter is identified. It is demonstrated to protect a bottom emission OLED device that was contaminated with standard sized glass beads. The photoresist and the organic layers below the barrier film causes sideways permeation that can reduce the lifetime set by permeation through the bulk of the barrier. To prevent the sideways permeation, an impermeable inorganic grid made of the same barrier material is designed. The reduction in sideways permeation due to the impermeable inorganic grid is demonstrated in an encapsulated OLED. In this work, we have dealt with three permeation mechanisms and shown solution to each of them. These steps give us reliable flexible encapsulation that has a lifetime of greater than 10 years.

Tunneling effect on double potential barriers GaAs and PbS

NASA Astrophysics Data System (ADS)

Prastowo, S. H. B.; Supriadi, B.; Ridlo, Z. R.; Prihandono, T.

2018-04-01

A simple model of transport phenomenon tunnelling effect through double barrier structure was developed. In this research we concentrate on the variation of electron energy which entering double potential barriers to transmission coefficient. The barriers using semiconductor materials GaAs (Galium Arsenide) with band-gap energy 1.424 eV, distance of lattice 0.565 nm, and PbS (Lead Sulphide) with band gap energy 0.41 eV distance of lattice is 18 nm. The Analysisof tunnelling effect on double potentials GaAs and PbS using Schrodinger’s equation, continuity, and matrix propagation to get transmission coefficient. The maximum energy of electron that we use is 1.0 eV, and observable from 0.0025 eV- 1.0 eV. The shows the highest transmission coefficient is0.9982 from electron energy 0.5123eV means electron can pass the barriers with probability 99.82%. Semiconductor from materials GaAs and PbS is one of selected material to design semiconductor device because of transmission coefficient directly proportional to bias the voltage of semiconductor device. Application of the theoretical analysis of resonant tunnelling effect on double barriers was used to design and develop new structure and combination of materials for semiconductor device (diode, transistor, and integrated circuit).

Potential Applications of Phyto-Derived Ceramides in Improving Epidermal Barrier Function.

PubMed

Tessema, Efrem N; Gebre-Mariam, Tsige; Neubert, Reinhard H H; Wohlrab, Johannes

2017-01-01

The outer most layer of the skin, the stratum corneum, consists of corneocytes which are coated by a cornified envelope and embedded in a lipid matrix of ordered lamellar structure. It is responsible for the skin barrier function. Ceramides (CERs) are the backbone of the intercellular lipid membranes. Skin diseases such as atopic dermatitis and psoriasis and aged skin are characterized by dysfunctional skin barrier and dryness which are associated with reduced levels of CERs. Previously, the effectiveness of supplementation of synthetic and animal-based CERs in replenishing the depleted natural skin CERs and restoring the skin barrier function have been investigated. Recently, however, the barrier function improving effect of plant-derived CERs has attracted much attention. Phyto-derived CERs (phytoCERs) are preferable due to their assumed higher safety as they are mostly isolated from dietary sources. The beneficial effects of phytoCER-based oral dietary supplements for skin hydration and skin barrier reinforcement have been indicated in several studies involving animal models as well as human subjects. Ingestible dietary supplements containing phytoCERs are also widely available on the market. Nonetheless, little effort has been made to investigate the potential cosmetic applications of topically administered phytoCERs. Therefore, summarizing the foregoing investigations and identifying the gap in the scientific data on plant-derived CERs intended for skin-health benefits are of paramount importance. In this review, an attempt is made to synthesize the information available in the literature regarding the effects of phytoCER-based oral dietary supplements on skin hydration and barrier function with the underlying mechanisms. © 2017 S. Karger AG, Basel.

Algal Turf Sediments and Sediment Production by Parrotfishes across the Continental Shelf of the Northern Great Barrier Reef

PubMed Central

Goatley, Christopher H. R.; Bellwood, David R.

2017-01-01

Sediments are found in the epilithic algal matrix (EAM) of all coral reefs and play important roles in ecological processes. Although we have some understanding of patterns of EAM sediments across individual reefs, our knowledge of patterns across broader spatial scales is limited. We used an underwater vacuum sampler to quantify patterns in two of the most ecologically relevant factors of EAM sediments across the Great Barrier Reef: total load and grain size distribution. We compare these patterns with rates of sediment production and reworking by parrotfishes to gain insights into the potential contribution of parrotfishes to EAM sediments. Inner-shelf reef EAMs had the highest sediment loads with a mean of 864.1 g m-2, compared to 126.8 g m-2 and 287.4 g m-2 on mid- and outer-shelf reefs, respectively. High sediment loads were expected on inner-shelf reefs due to their proximity to the mainland, however, terrigenous siliceous sediments only accounted for 13–24% of total mass. On inner-shelf reef crests parrotfishes would take three months to produce the equivalent mass of sediment found in the EAM. On the outer-shelf it would take just three days, suggesting that inner-shelf EAMs are characterised by low rates of sediment turnover. By contrast, on-reef sediment production by parrotfishes is high on outer-shelf crests. However, exposure to oceanic swells means that much of this production is likely to be lost. Hydrodynamic activity also appears to structure sediment patterns at within-reef scales, with coarser sediments (> 250 μm) typifying exposed reef crest EAMs, and finer sediments (< 250 μm) typifying sheltered back-reef EAMs. As both the load and grain size of EAM sediments mediate a number of important ecological processes on coral reefs, the observed sediment gradients are likely to play a key role in the structure and function of the associated coral reef communities. PMID:28122042

A test of trophic cascade theory: fish and benthic assemblages across a predator density gradient on coral reefs.

PubMed

Casey, Jordan M; Baird, Andrew H; Brandl, Simon J; Hoogenboom, Mia O; Rizzari, Justin R; Frisch, Ashley J; Mirbach, Christopher E; Connolly, Sean R

2017-01-01

Removal of predators is often hypothesized to alter community structure through trophic cascades. However, despite recent advances in our understanding of trophic cascades, evidence is often circumstantial on coral reefs because fishing pressure frequently co-varies with other anthropogenic effects, such as fishing for herbivorous fishes and changes in water quality due to pollution. Australia's outer Great Barrier Reef (GBR) has experienced fishing-induced declines of apex predators and mesopredators, but pollution and targeting of herbivorous fishes are minimal. Here, we quantify fish and benthic assemblages across a fishing-induced predator density gradient on the outer GBR, including apex predators and mesopredators to herbivores and benthic assemblages, to test for evidence of trophic cascades and alternative hypotheses to trophic cascade theory. Using structural equation models, we found no cascading effects from apex predators to lower trophic levels: a loss of apex predators did not lead to higher levels of mesopredators, and this did not suppress mobile herbivores and drive algal proliferation. Likewise, we found no effects of mesopredators on lower trophic levels: a decline of mesopredators was not associated with higher abundances of algae-farming damselfishes and algae-dominated reefs. These findings indicate that top-down forces on coral reefs are weak, at least on the outer GBR. We conclude that predator-mediated trophic cascades are probably the exception rather than the rule in complex ecosystems such as the outer GBR.

Self-actuated nuclear reactor shutdown system using induction pump to facilitate sensing of core coolant temperature

DOEpatents

Sievers, Robert K.; Cooper, Martin H.; Tupper, Robert B.

1987-01-01

A self-actuated shutdown system incorporated into a reactivity control assembly in a nuclear reactor includes pumping means for creating an auxiliary downward flow of a portion of the heated coolant exiting from the fuel assemblies disposed adjacent to the control assembly. The shutdown system includes a hollow tubular member which extends through the outlet of the control assembly top nozzle so as to define an outer annular flow channel through the top nozzle outlet separate from an inner flow channel for primary coolant flow through the control assembly. Also, a latching mechanism is disposed in an inner duct of the control assembly and is operable for holding absorber bundles in a raised position in the control assembly and for releasing them to drop them into the core of the reactor for shutdown purposes. The latching mechanism has an inner flow passage extending between and in flow communication with the absorber bundles and the inner flow channel of the top nozzle for accommodating primary coolant flow upwardly through the control assembly. Also, an outer flow passage separate from the inner flow passage extends through the latching mechanism between and in flow communication with the inner duct and the outer flow channel of the top nozzle for accommodating inflow of a portion of the heated coolant from the adjacent fuel assemblies. The latching mechanism contains a magnetic material sensitive to temperature and operable to cause mating or latching together of the components of the latching mechanism when the temperature sensed is below a known temperature and unmating or unlatching thereof when the temperature sensed is above a given temperature. The temperature sensitive magnetic material is positioned in communication with the heated coolant flow through the outer flow passage for directly sensing the temperature thereof. Finally, the pumping means includes a jet induction pump nozzle and diffuser disposed adjacent the bottom nozzle of the control assembly and in flow communication with the inlet thereof. The pump nozzle is operable to create an upward driving flow of primary coolant through the pump diffuser and then to the absorber bundles. The upward driving flow of primary coolant, in turn, creates a suction head within the outer flow channel of the top nozzle and thereby an auxiliary downward flow of the heated coolant portion exiting from the upper end of the adjacent fuel assemblies through the outer flow channel to the pump nozzle via the outer flow passage of the latching mechanism and an annular space between the outer and inner spaced ducts of the control assembly housing. The temperature of the heated coolant exiting from the adjacent fuel assemblies can thereby be sensed directly by the temperature sensitive magnetic material in the latching mechanism.

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

Bazzarella, Ricardo; Slocum, Alexander H.; Doherty, Tristan

Electrochemical cells and methods of making electrochemical cells are described herein. In some embodiments, an apparatus includes a multi-layer sheet for encasing an electrode material for an electrochemical cell. The multi-layer sheet including an outer layer, an intermediate layer that includes a conductive substrate, and an inner layer disposed on a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer. The inner layer defines an opening through which a conductive region of the intermediate layer is exposed such that the electrode material can be electrically connected to the conductive region. Thus,more » the intermediate layer can serve as a current collector for the electrochemical cell.« less

Electrochemical cells and methods of manufacturing the same

DOEpatents

Bazzarella, Ricardo; Slocum, Alexander H; Doherty, Tristan; Cross, III, James C

2015-11-03

Electrochemical cells and methods of making electrochemical cells are described herein. In some embodiments, an apparatus includes a multi-layer sheet for encasing an electrode material for an electrochemical cell. The multi-layer sheet including an outer layer, an intermediate layer that includes a conductive substrate, and an inner layer disposed on a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer. The inner layer defines an opening through which a conductive region of the intermediate layer is exposed such that the electrode material can be electrically connected to the conductive region. Thus, the intermediate layer can serve as a current collector for the electrochemical cell.

Portable heatable container

NASA Technical Reports Server (NTRS)

Yang, L. C. (Inventor)

1980-01-01

A container is provided which can be designed to heat its outer surface to sterilize it, or to heat its inner surface and any contents therewithin. In a container that self sterilizes its outer surface, the container includes a combustible layer of thermite-type pyrotechnic material which can be ignited to generate considerable heat, and a thin casing around the combustible layer which is of highly thermally conductive materials such as aluminum which can be heated to a high temperature by the ignited combustible layer. A buffer layer which may be of metal, lies within the combustible layer, and a layer of insulation such as Teflon lies within the buffer layer to insulate the contents of the container from the heat.

Portable heatable container

NASA Astrophysics Data System (ADS)

Yang, L. C.

1980-03-01

A container is provided which can be designed to heat its outer surface to sterilize it, or to heat its inner surface and any contents therewithin. In a container that self sterilizes its outer surface, the container includes a combustible layer of thermite-type pyrotechnic material which can be ignited to generate considerable heat, and a thin casing around the combustible layer which is of highly thermally conductive materials such as aluminum which can be heated to a high temperature by the ignited combustible layer. A buffer layer which may be of metal, lies within the combustible layer, and a layer of insulation such as Teflon lies within the buffer layer to insulate the contents of the container from the heat.

Application of CFRP with High Hydrogen Gas Barrier Characteristics to Fuel Tanks of Space Transportation System

NASA Astrophysics Data System (ADS)

Yonemoto, Koichi; Yamamoto, Yuta; Okuyama, Keiichi; Ebina, Takeo

In the future, carbon fiber reinforced plastics (CFRPs) with high hydrogen gas barrier performance will find wide applications in all industrial hydrogen tanks that aim at weight reduction; the use of such materials will be preferred to the use of conventional metallic materials such as stainless steel or aluminum. The hydrogen gas barrier performance of CFRP will become an important issue with the introduction of hydrogen-fuel aircraft. It will also play an important role in realizing fully reusable space transportation system that will have high specific tensile CFRP structures. Such materials are also required for the manufacture of high-pressure hydrogen gas vessels for use in the fuel cell systems of automobiles. This paper introduces a new composite concept that can be used to realize CFRPs with high hydrogen gas barrier performance for applications in the cryogenic tanks of fully reusable space transportation system by the incorporation of a nonmetallic crystal layer, which is actually a dense and highly oriented clay crystal laminate. The preliminary test results show that the hydrogen gas barrier characteristics of this material after cryogenic heat shocks and cyclic loads are still better than those of other polymer materials by approximately two orders of magnitude.

Device and method for producing a containment barrier underneath and around in-situ buried waste

DOEpatents

Gardner, B.M.; Smith, A.M.; Hanson, R.W.; Hodges, R.T.

1998-08-11

An apparatus is described for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably on which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment. 15 figs.

Underground barrier construction apparatus with soil-retaining shield

DOEpatents

Gardner, B.M.; Smith, A.M.; Hanson, R.W.; Hodges, R.T.

1998-08-04

An apparatus is described for building a horizontal underground barrier by cutting through soil and depositing a slurry, preferably one which cures into a hardened material. The apparatus includes a digging means for cutting and removing soil to create a void under the surface of the ground, a shield means for maintaining the void, and injection means for inserting barrier-forming material into the void. In one embodiment, the digging means is a continuous cutting chain. Mounted on the continuous cutting chain are cutter teeth for cutting through soil and discharge paddles for removing the loosened soil. This invention includes a barrier placement machine, a method for building an underground horizontal containment barrier using the barrier placement machine, and the underground containment system. Preferably the underground containment barrier goes underneath and around the site to be contained in a bathtub-type containment. 17 figs.

Isotopic evidence for primordial molecular cloud material in metal-rich carbonaceous chondrites.

PubMed

Van Kooten, Elishevah M M E; Wielandt, Daniel; Schiller, Martin; Nagashima, Kazuhide; Thomen, Aurélien; Larsen, Kirsten K; Olsen, Mia B; Nordlund, Åke; Krot, Alexander N; Bizzarro, Martin

2016-02-23

The short-lived (26)Al radionuclide is thought to have been admixed into the initially (26)Al-poor protosolar molecular cloud before or contemporaneously with its collapse. Bulk inner Solar System reservoirs record positively correlated variability in mass-independent (54)Cr and (26)Mg*, the decay product of (26)Al. This correlation is interpreted as reflecting progressive thermal processing of in-falling (26)Al-rich molecular cloud material in the inner Solar System. The thermally unprocessed molecular cloud matter reflecting the nucleosynthetic makeup of the molecular cloud before the last addition of stellar-derived (26)Al has not been identified yet but may be preserved in planetesimals that accreted in the outer Solar System. We show that metal-rich carbonaceous chondrites and their components have a unique isotopic signature extending from an inner Solar System composition toward a (26)Mg*-depleted and (54)Cr-enriched component. This composition is consistent with that expected for thermally unprocessed primordial molecular cloud material before its pollution by stellar-derived (26)Al. The (26)Mg* and (54)Cr compositions of bulk metal-rich chondrites require significant amounts (25-50%) of primordial molecular cloud matter in their precursor material. Given that such high fractions of primordial molecular cloud material are expected to survive only in the outer Solar System, we infer that, similarly to cometary bodies, metal-rich carbonaceous chondrites are samples of planetesimals that accreted beyond the orbits of the gas giants. The lack of evidence for this material in other chondrite groups requires isolation from the outer Solar System, possibly by the opening of disk gaps from the early formation of gas giants.

Isotopic evidence for primordial molecular cloud material in metal-rich carbonaceous chondrites

PubMed Central

Van Kooten, Elishevah M. M. E.; Wielandt, Daniel; Schiller, Martin; Nagashima, Kazuhide; Thomen, Aurélien; Olsen, Mia B.; Nordlund, Åke; Krot, Alexander N.; Bizzarro, Martin

2016-01-01

The short-lived 26Al radionuclide is thought to have been admixed into the initially 26Al-poor protosolar molecular cloud before or contemporaneously with its collapse. Bulk inner Solar System reservoirs record positively correlated variability in mass-independent 54Cr and 26Mg*, the decay product of 26Al. This correlation is interpreted as reflecting progressive thermal processing of in-falling 26Al-rich molecular cloud material in the inner Solar System. The thermally unprocessed molecular cloud matter reflecting the nucleosynthetic makeup of the molecular cloud before the last addition of stellar-derived 26Al has not been identified yet but may be preserved in planetesimals that accreted in the outer Solar System. We show that metal-rich carbonaceous chondrites and their components have a unique isotopic signature extending from an inner Solar System composition toward a 26Mg*-depleted and 54Cr-enriched component. This composition is consistent with that expected for thermally unprocessed primordial molecular cloud material before its pollution by stellar-derived 26Al. The 26Mg* and 54Cr compositions of bulk metal-rich chondrites require significant amounts (25–50%) of primordial molecular cloud matter in their precursor material. Given that such high fractions of primordial molecular cloud material are expected to survive only in the outer Solar System, we infer that, similarly to cometary bodies, metal-rich carbonaceous chondrites are samples of planetesimals that accreted beyond the orbits of the gas giants. The lack of evidence for this material in other chondrite groups requires isolation from the outer Solar System, possibly by the opening of disk gaps from the early formation of gas giants. PMID:26858438

Multifunctional reference electrode

DOEpatents

Redey, Laszlo; Vissers, Donald R.

1983-01-01

A multifunctional, low mass reference electrode of a nickel tube, thermocouple means inside the nickel tube electrically insulated therefrom for measuring the temperature thereof, a housing surrounding the nickel tube, an electrolyte having a fixed sulfide ion activity between the housing and the outer surface of the nickel tube forming the nickel/nickel sulfide/sulfide half-cell. An ion diffusion barrier is associated with the housing in contact with the electrolyte. Also disclosed is a cell using the reference electrode to measure characteristics of a working electrode.

Formation and distribution of fragments in the spontaneous fission of 240 Pu

DOE PAGES

Sadhukhan, Jhilam; Zhang, Chunli; Nazarewicz, Witold; ...

2017-12-18

We use the stochastic Langevin framework to simulate the nuclear evolution after the system tunnels through the multidimensional potential barrier. For a representative sample of different initial configurations along the outer turning-point line, we define effective fission paths by computing a large number of Langevin trajectories. We extract the relative contribution of each such path to the fragment distribution. We then use nucleon localization functions along effective fission pathways to analyze the characteristics of prefragments at prescission configurations.

The target of daptomycin is absent from Escherichia coli and other gram-negative pathogens.

PubMed

Randall, Christopher P; Mariner, Katherine R; Chopra, Ian; O'Neill, Alex J

2013-01-01

Antistaphylococcal agents commonly lack activity against Gram-negative bacteria like Escherichia coli owing to the permeability barrier presented by the outer membrane and/or the action of efflux transporters. When these intrinsic resistance mechanisms are artificially compromised, such agents almost invariably demonstrate antibacterial activity against Gram negatives. Here we show that this is not the case for the antibiotic daptomycin, whose target appears to be absent from E. coli and other Gram-negative pathogens.

Multifunctional reference electrode

DOEpatents

Redey, L.; Vissers, D.R.

1981-12-30

A multifunctional, low mass reference electrode of a nickel tube, thermocouple means inside the nickel tube electrically insulated therefrom for measuring the temperature thereof, a housing surrounding the nickel tube, an electrolyte having a fixed sulfide ion activity between the housing and the outer surface of the nickel tube forming the nickel/nickel sulfide/sulfide half-cell are described. An ion diffusion barrier is associated with the housing in contact with the electrolyte. Also disclosed is a cell using the reference electrode to measure characteristics of a working electrode.

ATS-6 - Synchronous orbit trapped radiation studies with an electron-proton spectrometer

NASA Technical Reports Server (NTRS)

Walker, R. J.; Swanson, R. L.; Winckler, J. R.; Erickson, K. N.

1975-01-01

The paper discusses the University of Minnesota experiment on ATS-6 designed to study the origin and dynamics of high-energy electrons and protons in the outer radiation belt and in the near-earth plasma sheet. The experiment consists of two nearly identical detector assemblies, each of which is a magnetic spectrometer containing four gold-silicon surface barrier detectors. The instrument provides a clean separation between protons and electrons by the combination of pulse height analysis and magnetic deflection.

Study of Plasma Flow Modes in Imploding Nested Arrays

NASA Astrophysics Data System (ADS)

Mitrofanov, K. N.; Aleksandrov, V. V.; Gritsuk, A. N.; Branitsky, A. V.; Frolov, I. N.; Grabovski, E. V.; Sasorov, P. V.; Ol'khovskaya, O. G.; Zaitsev, V. I.

2018-02-01

Results from experimental studies of implosion of nested wire and fiber arrays at currents of up to 4 MA at the Angara-5-1 facility are presented. Depending on the ratio between the radii of the inner and outer arrays, different modes of the plasma flow in the space between the inner and outer arrays were implemented: the sub-Alfvénic ( V r < V A ) and super-Alfvénic ( V r > V A ) modes and a mode with the formation of the transition shock wave (SW) region between the cascades. By varying the material of the outer array (tungsten wires or kapron fibers), it is shown that the plasma flow mode between the inner and outer arrays depends on the ratio between the plasma production rates ṁ in / ṁ out in the inner and outer arrays. The obtained experimental results are compared with the results of one-dimensional MHD simulation of the plasma flow between the arrays. Stable implosion of the inner array plasma was observed in experiments with combined nested arrays consisting of a fiber outer array and a tungsten inner array. The growth rates of magnetic Rayleigh-Taylor (MRT) instability in the inner array plasma at different numbers of fibers in the outer array and different ratios between the radii of the inner and outer arrays are compared. Suppression of MRT instability during the implosion of the inner array plasma results in the formation of a stable compact Z-pinch and generation of a soft X-ray pulse. A possible scenario of interaction between the plasmas of the inner and outer arrays is offered. The stability of the inner array plasma in the stage of final compression depends on the character of interaction of plasma jets from the outer array with the magnetic field of the inner array.

Assessment of Residual Stresses in 3013 Inner and Outer Containers and Teardrop Samples

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

Stroud, Mary Ann; Prime, Michael Bruce; Veirs, Douglas Kirk

2015-12-08

This report is an assessment performed by LANL that examines packaging for plutonium-bearing materials and the resilience of its design. This report discusses residual stresses in the 3013 outer, the SRS/Hanford and RFETS/LLNL inner containers, and teardrop samples used in studies to assess the potential for SCC in 3013 containers. Residual tensile stresses in the heat affected zones of the closure welds are of particular concern.

Time and materials needed to survey, inject systemic fungicides, and install root-graft barriers for Dutch elm disease management

Treesearch

William N., Jr. Cannon; Jack H. Barger; Charles J. Kostichka; Charles J. Kostichka

1986-01-01

Dutch elm disease control practice in 15 communities showed a wide range of time and material required to apply control methods. The median time used for each method was: sanitation survey, 9.8 hours per square mile; symptom survey, 96 hours per thousand elms; systemic fungicide injection, 1.4 hours per elm; and root-graft barrier installation, 2.2 hours per barrier (5...

Analytical instrument with apparatus and method for sample concentrating

DOEpatents

Zaromb, S.

1986-08-04

A system for analysis of trace concentrations of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

Analytical instrument with apparatus for sample concentrating

DOEpatents

Zaromb, Solomon

1989-01-01

A system for analysis of trace concentrations of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

Method for preconcentrating a sample for subsequent analysis

DOEpatents

Zaromb, Solomon

1990-01-01

A system for analysis of trace concentration of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

Noble Gas Inventory of Micrometeorites Collected at the Transantarctic Mountains (TAM) and Indications for Their Provenance

NASA Technical Reports Server (NTRS)

Ott, U.; Baecker, B.; Folco, L.; Cordier, C.

2016-01-01

A variety of processes have been considered possibly contributing the volatiles including noble gases to the atmospheres of the terrestrial planets (e.g., [1-3]). Special consideration has been given to the concept of accretion of volatile-rich materials by the forming planets. This might include infalling planetesimals and dust, and could include material from the outer asteroid belt, as well as cometary material from the outer solar system. Currently, the dominant source of extraterrestrial material accreted by the Earth is represented by micrometeorites (MMs) with sizes mostly in the 100-300 micron range [3, 4]). Their role has been assessed by [3], who conclude that accretion of early micrometeorites played a major role in the formation of the terrestrial atmosphere and oceans. We have therefore set out to investigate in more detail the inventory of noble gases in MMs. Here we summarize some of our results obtained on MMs collected in micrometeorite traps of the Transantarctic Mountains [5].

Conduit for high temperature transfer of molten semiconductor crystalline material

NASA Technical Reports Server (NTRS)

Fiegl, George (Inventor); Torbet, Walter (Inventor)

1983-01-01

A conduit for high temperature transfer of molten semiconductor crystalline material consists of a composite structure incorporating a quartz transfer tube as the innermost member, with an outer thermally insulating layer designed to serve the dual purposes of minimizing heat losses from the quartz tube and maintaining mechanical strength and rigidity of the conduit at the elevated temperatures encountered. The composite structure ensures that the molten semiconductor material only comes in contact with a material (quartz) with which it is compatible, while the outer layer structure reinforces the quartz tube, which becomes somewhat soft at molten semiconductor temperatures. To further aid in preventing cooling of the molten semiconductor, a distributed, electric resistance heater is in contact with the surface of the quartz tube over most of its length. The quartz tube has short end portions which extend through the surface of the semiconductor melt and which are lef bare of the thermal insulation. The heater is designed to provide an increased heat input per unit area in the region adjacent these end portions.

FY2016 Propulsion Materials Annual Progress Report

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

None, None

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines and Fuels) teams to develop strategies thatmore » overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.« less

The Gulliver Mission: A Short-Cut to Primitive Body and Mars Sample Return

NASA Astrophysics Data System (ADS)

Britt, D. T.

2003-05-01

The Martian moon Deimos has extraordinary potential for future sample return missions. Deimos is spectrally similar to D-type asteroids and may be a captured primitive asteroid that originated in the outer asteroid belt. This capture probably took place in the earliest periods of Martian history, over 4.4 Gyrs ago [1], and Deimos has been accumulating material ejected from the Martian surface ever since. Analysis of Martian ejecta, material accumulation, capture cross-section, regolith over-turn, and Deimos's albedo suggest that Mars material may make up as much as 10% of Deimos's regolith. The Martian material on Deimos would be dominated by ejecta from the ancient crust of Mars, delivered during the Noachian Period of basin-forming impacts and heavy bombardment. Deimos could be a repository of samples from ancient Mars, including the full range of Martian crustal and upper mantle material from the early differentiation and crustal-forming epoch as well as samples from the era of high volatile flux, thick atmosphere, and possible surface water. In addition to Martian ejecta, 90% of the Deimos sample will be spectral type D asteroidal material. D-type asteroids are thought to be highly primitive and are most common in the difficult to access outer asteroid belt and the Jupiter Trojans. The Gulliver Mission proposes to directly collect up to 10 kilograms of Deimos regolith and return it to Earth. This sample may contain up to 1000 grams of Martian material along with up to 9 kilograms of primitive asteroidal material. Because of stochastic processes of regolith mixing over 4.4 Gyrs, the rock fragments and grains will likely sample the diversity of the Martian ancient surface as well as the asteroid. In essence, Gulliver represents two shortcuts, to Mars sample return and to the outer asteroid belt. References: [1] Burns J. A. (1992) Mars (Kieffer H. H. et al., eds), 1283-1302.

Vacuum barrier for excimer lasers

DOEpatents

Shurter, Roger P.

1992-01-01

A barrier for separating the vacuum area of a diode from the pressurized gas area of an excimer laser. The barrier is a composite material comprising layers of a metal such as copper, along with layers of polyimide, and a matrix of graphite fiber yarns impregnated with epoxy. The barrier is stronger than conventional foil barriers, and allows greater electron throughput.

[Moisture and mold on the inner walls of prefabricated building slabs--investigating a strange cause].

PubMed

Kaufhold, T; Fiedler, K; Jung, G; Lindner, M; Gassel, R P

1997-04-01

Reasons for indoor-moisture beyond the normal level can be caused by penetrating dampness, condensation-water, and apartment misuse. A fall in the air temperature below the dew point in connection with moulding inside buildings becomes evident mostly at places like badly insulated outer-walls or room-corners. In a number of houses built between 1980 and 1983 in the so called "Plattenbauweise" (prefabricated slabs), exclusively the inner-walls were covered in mould around cracks in the walls. Examinations showed connections between the apartment and the outer-corridor with a slight exchange of air through the cracks. Warm, wet air escaped from the apartment into the outer-corridor, and cold air entered the apartment from the outer-corridor. This temporary fall below the dewpoint caused by suitable variation of temperature probably resulted in the building materials and wallpapers becoming damp, as well as the growth of mould.

Load-resistant coaxial transmission line

DOEpatents

Hall, David R.; Fox, Joe

2006-01-03

A transmission line for downhole tools that make up all or part of a tool string for drilling and production of oil, gas, and geothermal wells that can withstand the dynamic gravitational forces and other accelerations associated with downhole excavations. The transmission line has a metal tube, or outer conductor, that houses a coaxial wire inner conductor. A non-metallic dielectric material is interposed between the inner and outer conductors. The outer and inner conductors and the dielectric are sufficiently compressed together so that independent motion between them is abated. Compression of the components of the transmission line may be achieved by drawing the transmission through one or more dies in order to draw down the outer conductor onto the dielectric, or by expanding the inner conductor against the dielectric using a mandrel or hydraulic pressure. Non-metallic bead segments may be used in aid of the compression necessary to resist the dynamic forces and accelerations of drilling.

Le concept suédois pour stockage définitif des déchets nucléaires

NASA Astrophysics Data System (ADS)

Hedman, Tommy; Nyström, Anders; Thegerström, Claes

2002-10-01

The purpose of a disposal is to isolate the radioactive waste from man and the environment. If the isolation is broken, the leakage and transport of radioactive substances must be retarded. The package is one of several barriers, used to achieve these two main functions. For short-lived, low and intermediate level waste four standard containers of steel and concrete are used. Spent fuel will be placed in a canister consisting of a pressure-bearing insert of cast nodular iron and an outer corrosion barrier of copper before it is deposited in a deep geological repository. In particular, the development of a high integrity copper canister for the isolation of spent nuclear fuel is described in this paper. To cite this article: T. Hedman et al., C. R. Physique 3 (2002) 903-913.

Multi-layer waste containment barrier

DOEpatents

Smith, Ann Marie; Gardner, Bradley M.; Nickelson, David F.

1999-01-01

An apparatus for constructing an underground containment barrier for containing an in-situ portion of earth. The apparatus includes an excavating device for simultaneously (i) excavating earthen material from beside the in-situ portion of earth without removing the in-situ portion and thereby forming an open side trench defined by opposing earthen sidewalls, and (ii) excavating earthen material from beneath the in-situ portion of earth without removing the in-situ portion and thereby forming a generally horizontal underground trench beneath the in-situ portion defined by opposing earthen sidewalls. The apparatus further includes a barrier-forming device attached to the excavating device for simultaneously forming a side barrier within the open trench and a generally horizontal, multi-layer barrier within the generally horizontal trench. The multi-layer barrier includes at least a first layer and a second layer.

Core-Cutoff Tool

NASA Technical Reports Server (NTRS)

Gheen, Darrell

2007-01-01

A tool makes a cut perpendicular to the cylindrical axis of a core hole at a predetermined depth to free the core at that depth. The tool does not damage the surrounding material from which the core was cut, and it operates within the core-hole kerf. Coring usually begins with use of a hole saw or a hollow cylindrical abrasive cutting tool to make an annular hole that leaves the core (sometimes called the plug ) in place. In this approach to coring as practiced heretofore, the core is removed forcibly in a manner chosen to shear the core, preferably at or near the greatest depth of the core hole. Unfortunately, such forcible removal often damages both the core and the surrounding material (see Figure 1). In an alternative prior approach, especially applicable to toxic or fragile material, a core is formed and freed by means of milling operations that generate much material waste. In contrast, the present tool eliminates the damage associated with the hole-saw approach and reduces the extent of milling operations (and, hence, reduces the waste) associated with the milling approach. The present tool (see Figure 2) includes an inner sleeve and an outer sleeve and resembles the hollow cylindrical tool used to cut the core hole. The sleeves are thin enough that this tool fits within the kerf of the core hole. The inner sleeve is attached to a shaft that, in turn, can be attached to a drill motor or handle for turning the tool. This tool also includes a cutting wire attached to the distal ends of both sleeves. The cutting wire is long enough that with sufficient relative rotation of the inner and outer sleeves, the wire can cut all the way to the center of the core. The tool is inserted in the kerf until its distal end is seated at the full depth. The inner sleeve is then turned. During turning, frictional drag on the outer core pulls the cutting wire into contact with the core. The cutting force of the wire against the core increases with the tension in the wire and, hence, with the frictional drag acting on the outer sleeve. As the wire cuts toward the center of the core, the inner sleeve rotates farther with respect to the outer sleeve. Once the wire has cut to the center of the core, the tool and the core can be removed from the hole. The proper choice of cutting wire depends on the properties of the core material. For a sufficiently soft core material, a nonmetallic monofilament can be used. For a rubber-like core material, a metal wire can be used. For a harder core material, it is necessary to use an abrasive wire, and the efficiency of the tool can be increased greatly by vacuuming away the particles generated during cutting. For a core material that can readily be melted or otherwise cut by use of heat, it could be preferable to use an electrically heated cutting wire. In such a case, electric current can be supplied to the cutting wire, from an electrically isolated source, via rotating contact rings mounted on the sleeves.

Dose Rate Calculation of TRU Metal Ingot in Pyroprocessing - 12202

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

Lee, Yoon Hee; Lee, Kunjai

Spent fuel management has been a main problem to be solved for continuous utilization of nuclear energy. Spent fuel management policy of Korea is 'Wait and See'. It is focused on Pyro-process and SFR (Sodium-cooled Fast Reactor) for closed-fuel cycle research and development in Korea. For peaceful use of nuclear facilities, the proliferation resistance has to be proved. Proliferation resistance is one of key constraints in the deployment of advanced nuclear energy systems. Non-proliferation and safeguard issues have been strengthening internationally. Barriers to proliferation are that reduces desirability or attractiveness as an explosive and makes it difficult to gain accessmore » to the materials, or makes it difficult to misuse facilities and/or technologies for weapons applications. Barriers to proliferation are classified into intrinsic and extrinsic barriers. Intrinsic barrier is inherent quality of reactor materials or the fuel cycle that is built into the reactor design and operation such as material and technical barriers. As one of the intrinsic measures, the radiation from the material is considered significantly. Therefore the radiation of TRU metal ingot from the pyro-process was calculated using ORIGEN and MCNP code. (authors)« less

Theoretical analysis of compatibility of several reinforcement materials with NiAl and FeAl matrices

NASA Technical Reports Server (NTRS)

Misra, Ajay K.

1989-01-01

Several potential reinforcement materials were assessed for their chemical, coefficient of thermal expansion (CTE), and mechanical compatibility with the intermetallic matrices based on NiAl and FeAl. Among the ceramic reinforcement materials, Al2O3, TiC, and TiB2, appear to be the optimum choices for NiAl and FeAl matrices. However, the problem of CTE mismatch with the matrix needs to be solved for these three reinforcement materials. Beryllium-rich intermetallic compounds can be considered as potential reinforcement materials provided suitable reaction barrier coatings can be developed for these. Based on preliminary thermodynamic calculations, Sc2O3 and TiC appear to be suitable as reaction barrier coatings for the beryllides. Several reaction barrier coatings are also suggested for the currently available SiC fibers.

X-ray photoelectron spectroscopy characterization of a nonsuperconducting Y-Ba-Cu-O superconductor-normal-metal-superconductor barrier material

NASA Technical Reports Server (NTRS)

Vasquez, R. P.; Hunt, B. D.; Foote, M. C.; Bajuk, L. J.

1992-01-01

A film of a novel nonsuperconducting Y-Ba-Cu-O (YBCO) barrier material was grown using conditions similar to those reported by Agostinelli et al. (1991) for forming a cubic semiconducting (c-YBCO) phase, and the material was characterized using X-ray photoelectron spectroscopy (XPS). A comparison of the XPS spectra of this material to those obtained from the orthorhombic and tetragonal phases of YBCO (o-YBCO and t-YBCO, respectively) showed that the barrier material had spectral characteristics different from those of o-YBCO and t-YBCO, particularly in the O 1s region. Features associated with the Cu-O chain and surface-reconstructed Cu-O planes were absent, consistent with expectations for the simple perovskite crystal structure of c-YBCO proposed by Agostinelli et al.

Observations and Laboratory Data of Planetary Organics

NASA Technical Reports Server (NTRS)

Roush, Ted L.

2002-01-01

Many efforts are underway to search for evidence of prebiotic materials in the outer solar system. Current and planned Mars missions obtain remote sensing observations that can be used to address the potential presence of prebiotic materials. Additional missions to, and continuing earth-based observations of, more distant solar system objects will also provide remote sensing observations that can be used to address the potential presence of prebiotic materials. I will present an overview of on-going observations, associated laboratory investigations of candidate materials, and theoretical modeling of observational data. In the past the room temperature reflectance spectra of many residues created from HC-bearing gases and solids have been reported. The results of an investigation of what effect temperatures more representative of outer solar system surfaces (50-140K) have on the reflectance spectra of these residues, and the associated interpretations, will be presented. The relatively organic-rich Tagish Lake Meteorite has been suggested as a spectral analog for Dtype asteroids. Using a new approach that relies upon iterative use of Hapke theory and Kraniers-Kronig analysis the optical constants of TLM were estimated. The approach and results of the analysis will be presented. Use of optical constants in scattering theories, such as the Hapke theory, provide the ability to determine quantitative estimates of the relative abundances and grain sizes of candidate surface components. This approach has been applied to interpret the reflectance spectra of several outer solar system surfaces. A summary will be provided describing the results of such modeling efforts.

Process for making ceramic hot gas filter

DOEpatents

Connolly, Elizabeth Sokolinski; Forsythe, George Daniel; Domanski, Daniel Matthew; Chambers, Jeffrey Allen; Rajendran, Govindasamy Paramasivam

2001-01-01

A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

Ceramic hot-gas filter

DOEpatents

Connolly, Elizabeth Sokolinski; Forsythe, George Daniel; Domanski, Daniel Matthew; Chambers, Jeffrey Allen; Rajendran, Govindasamy Paramasivam

1999-01-01

A ceramic hot-gas candle filter having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during backpulse cleaning and is resistant to chemical degradation at high temperatures.

Fused silica reflecting heat shields for outer planet entry probes

NASA Technical Reports Server (NTRS)

Congdon, W. M.; Peterson, D. L.

1975-01-01

The development of slip-cast fused silica is discussed as a heat shield designed to meet the needs of outer-planet entry probes. The distinguishing feature of silica is its ability to reflect the radiation imposed by planetary-entry environments. This reflectivity is particularly sensitive to degradation by the presence of trace amounts of contaminants introduced by the starting materials or by processing. The microstructure of a silica configuration also significantly influences the reflectivity and other thermomechanical properties. The processing techniques attendant on controlling microstructure while maintaining purity are discussed. The selection of a starting material of essential purity precludes the use of purified natural quartz and requires the use of synthetic fused silica. The silica is characterized in a limited combined heating test environment. The surface mass loss is controlled by liquid runoff from a relatively low-temperature melt layer; the reflectance is basically maintained and the material achieves a surprisingly high heat of ablation.

Method to produce large, uniform hollow spherical shells

DOEpatents

Hendricks, C.D.

1983-09-26

The invention is a method to produce large uniform hollow spherical shells by (1) forming uniform size drops of heat decomposable or vaporizable material, (2) evaporating the drops to form dried particles, (3) coating the dried particles with a layer of shell forming material and (4) heating the composite particles to melt the outer layer and to decompose or vaporize the inner particle to form an expanding inner gas bubble. The expanding gas bubble forms the molten outer layer into a shell of relatively large diameter. By cycling the temperature and pressure on the molten shell, nonuniformities in wall thickness can be reduced. The method of the invention is utilized to produce large uniform spherical shells, in the millimeter to centimeter diameter size range, from a variety of materials and of high quality, including sphericity, concentricity and surface smoothness, for use as laser fusion or other inertial confinement fusion targets as well as other applications.

Development of improved amorphous materials for laser systems

NASA Technical Reports Server (NTRS)

Neilson, G. F.; Weinberg, M. C.

1974-01-01

Crystallization calculations were performed in order to determine the possibility of forming a particular type of laser glass with the avoidance of devitrification in an outer space laboratory. It was demonstrated that under the homogenuous nucleating conditions obtainable in a zero gravity laboratory this laser glass may be easily quenched to a virtually crystal-free product. Experimental evidence is provided that use of this material as a host in a neodymium glass laser would result in more than a 10 percent increase in efficiency when compared to laser glass rods of a similar composition currently commercially available. Differential thermal analysis, thermal gradient oven, X-ray diffraction, and liquidus determination experiments were carried out to determine the basics of the crystallization behavior of the glass, and small-angle X-ray scattering and splat-cooling experiments were performed in order to provide additional evidence for the feasibility of producing this laser glass material, crystal free, in an outer space environment.

Ceramic hot-gas filter

DOEpatents

Connolly, E.S.; Forsythe, G.D.; Domanski, D.M.; Chambers, J.A.; Rajendran, G.P.

1999-05-11

A ceramic hot-gas candle filter is described having a porous support of filament-wound oxide ceramic yarn at least partially surrounded by a porous refractory oxide ceramic matrix, and a membrane layer on at least one surface thereof. The membrane layer may be on the outer surface, the inner surface, or both the outer and inner surface of the porous support. The membrane layer may be formed of an ordered arrangement of circularly wound, continuous filament oxide ceramic yarn, a ceramic filler material which is less permeable than the filament-wound support structure, or some combination of continuous filament and filler material. A particularly effective membrane layer features circularly wound filament with gaps intentionally placed between adjacent windings, and a filler material of ceramic particulates uniformly distributed throughout the gap region. The filter can withstand thermal cycling during back pulse cleaning and is resistant to chemical degradation at high temperatures.

Method of making dense, conformal, ultra-thin cap layers for nanoporous low-k ILD by plasma assisted atomic layer deposition

DOEpatents

Jiang, Ying-Bing [Albuquerque, NM; Cecchi, Joseph L [Albuquerque, NM; Brinker, C Jeffrey [Albuquerque, NM

2011-05-24

Barrier layers and methods for forming barrier layers on a porous layer are provided. The methods can include chemically adsorbing a plurality of first molecules on a surface of the porous layer in a chamber and forming a first layer of the first molecules on the surface of the porous layer. A plasma can then be used to react a plurality of second molecules with the first layer of first molecules to form a first layer of a barrier layer. The barrier layers can seal the pores of the porous material, function as a diffusion barrier, be conformal, and/or have a negligible impact on the overall ILD k value of the porous material.

Outer retinal corrugations in age-related macular degeneration.

PubMed

Ooto, Sotaro; Vongkulsiri, Sritatath; Sato, Taku; Suzuki, Mihoko; Curcio, Christine A; Spaide, Richard F

2014-07-01

Optical coherence tomography (OCT) abnormalities of age-related macular degeneration (AMD) have not been fully characterized because of the complex morphology and a lack of correlative histologic studies. Expansion of our ability to interpret increasing attributes brings us closer to the goal of in vivo histologic analysis of the eye by OCT. To describe a new outer retinal finding of AMD using spectral-domain (SD) OCT and suggest histopathologic correlates. Twenty-five eyes of 16 patients with AMD with severe atrophy due to either choroidal neovascularization (CNV) or geographic atrophy (GA) and 53 donor eyes of 53 patients with late AMD were included. Imaging studies were conducted at a referral retinal practice and histopathology was done at a university research laboratory. Findings in the outer retina were evaluated in SD-OCT images in eyes with atrophy of the retinal pigment epithelium (RPE) and compared with histopathologic findings in eyes with GA or CNV that also showed loss of the RPE. Spectral-domain OCT and histologic characteristics of the outer retina. The mean (SD) age of the 16 patients was 82.7 (7.9) years. Twenty eyes had CNV and 5 eyes had GA. The mean best-corrected visual acuity was 0.800 logMAR (interquartile range, 0.350-1.000 logMAR), a Snellen equivalent of 20/126. A curvilinear hyperreflective density was identified above the Bruch membrane line within the atrophic area in the SD-OCT images. At the internal border, the material was contiguous with the outer portion of the RPE band. Below the material was a relatively hyporeflective space. The material was thrown into folds in cases with atrophy following CNV or was seen as a sheet with numerous bumps in eyes with GA. Review of histopathologic findings of eyes with advanced GA and CNV revealed a rippled layer of basal laminar deposits in an area of RPE atrophy that was located in the same level as the curvilinear line seen in the OCT images. We have described a new entity, termed outer retinal corrugations, which may correspond to histological findings of basal laminar deposits, extracellular deposits that persist in eyes with late AMD. Observation of this undulating band does not necessarily mean there is exudation or leakage; as a consequence, these patients do not need treatment based on this solitary finding.

49 CFR 173.4a - Excepted quantities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of withstanding without leakage the pressure differential specified in § 173.27(c) of this part. (b... ice), and lithium batteries and cells. (c) Inner packaging limits. The maximum quantity of hazardous..., rigid outer packaging. (5) Placement of the material in the package or packing different materials in...

49 CFR 178.609 - Test requirements for packagings for infectious substances.

Code of Federal Regulations, 2010 CFR

2010-10-01

... paragraph (c), which, for test purposes, categorizes packagings according to their material characteristics... performance may be rapidly affected by moisture; plastics that may embrittle at low temperature; and other... the appropriate test. Table I—Tests Required Material of Outer packaging Fiberboard Plastics Other...

5 CFR 1312.28 - Transmission of classified material.

Code of Federal Regulations, 2012 CFR

2012-01-01

... CLASSIFICATION, DOWNGRADING, DECLASSIFICATION AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION Control and... outer covers or envelopes. The inner cover will be sealed and marked with the classification, and the... Confidential material) will be attached to or placed within the inner envelope to be signed by the recipient...

5 CFR 1312.28 - Transmission of classified material.

Code of Federal Regulations, 2011 CFR

2011-01-01

... CLASSIFICATION, DOWNGRADING, DECLASSIFICATION AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION Control and... outer covers or envelopes. The inner cover will be sealed and marked with the classification, and the... Confidential material) will be attached to or placed within the inner envelope to be signed by the recipient...

5 CFR 1312.28 - Transmission of classified material.

Code of Federal Regulations, 2013 CFR

2013-01-01

... CLASSIFICATION, DOWNGRADING, DECLASSIFICATION AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION Control and... outer covers or envelopes. The inner cover will be sealed and marked with the classification, and the... Confidential material) will be attached to or placed within the inner envelope to be signed by the recipient...

5 CFR 1312.28 - Transmission of classified material.

Code of Federal Regulations, 2014 CFR

2014-01-01

... CLASSIFICATION, DOWNGRADING, DECLASSIFICATION AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION Control and... outer covers or envelopes. The inner cover will be sealed and marked with the classification, and the... Confidential material) will be attached to or placed within the inner envelope to be signed by the recipient...

Characterization of the interaction between two food aroma components, alpha-pinene and ethyl butyrate, and ethylene-vinyl alcohol copolymer (EVOH) packaging films as a function of environmental humidity.

PubMed

López-Carballo, Gracia; Cava, David; Lagarón, Jose M; Catalá, Ramón; Gavara, Rafael

2005-09-07

The ethylene-vinyl alcohol copolymers (EVOHs) are well-known high oxygen barrier materials that are being used successfully in the design of packaging structures for oxygen-sensitive food or pharmaceutical products. Recently, there has been increasing interest in using EVOH materials to provide a high barrier to organic compounds as a means to reduce food aroma scalping. However, the barrier function of this family of materials diminishes significantly in humid environments, and it is supposed that so does the organic vapor barrier. In this work, a new sorption-based method to characterize the interaction between food aroma and polymer films for packaging as a function of relative humidity is presented and is used to determine the barrier to ethyl butyrate and alpha-pinene of EVOH at 23 degrees C. The results show that although EVOH is an excellent barrier to food aroma when dry, a property that even improves at low relative humidity (RH), the solubility and diffusivity of the compounds tested increase dramatically with humidity at medium to high water activities. However, even in the worst case (100% RH), EVOH outperforms low-density polyethylene (LDPE) as a barrier to organic vapors at least 500,000-fold.

Kinetic Monte Carlo Simulation of Oxygen Diffusion in Ytterbium Disilicate

NASA Astrophysics Data System (ADS)

Good, Brian

2015-03-01

Ytterbium disilicate is of interest as a potential environmental barrier coating for aerospace applications, notably for use in next generation jet turbine engines. In such applications, the diffusion of oxygen and water vapor through these coatings is undesirable if high temperature corrosion is to be avoided. In an effort to understand the diffusion process in these materials, we have performed kinetic Monte Carlo simulations of vacancy-mediated oxygen diffusion in Ytterbium Disilicate. Oxygen vacancy site energies and diffusion barrier energies are computed using Density Functional Theory. We find that many potential diffusion paths involve large barrier energies, but some paths have barrier energies smaller than one electron volt. However, computed vacancy formation energies suggest that the intrinsic vacancy concentration is small in the pure material, with the result that the material is unlikely to exhibit significant oxygen permeability.

The Li And Be Dips Revisited: The Role Of Gyroscopic Pumping.

NASA Astrophysics Data System (ADS)

Garaud, Pascale; Bodenheimer, P.

2011-01-01

The existence of a dip in the observed abundances of Li and Be in young stars in the mass range 1.3 to 1.5 solar masses strongly suggests the presence of an additional mixing mechanism to transport these elements from the outer convection zone down to the region where they are destroyed. However, no simple model to date has been able to reproduce simultaneously the respective amplitudes of the Li and the Be dips, as well as their shapes. We study here the effect of an important new mechanism for rotational mixing called "gyroscopic pumping", first noted for its importance in the dynamics of the solar interior, and find that it does indeed provide an elegant answer to this long-standing problem. Gyroscopic pumping is a simple and very generic consequence of angular momentum conservation in differentially rotating convective regions. The perpetual azimuthal force driving the differential rotation also drives a large-scale meridional circulation through angular momentum conservation. We show here how, specifically for the mass range of the Li-dip stars, the flows thus pumped form a slow, large-scale "conveyor belt" between the inner convective core and the outer convection zone. Li- and Be-rich material flowing down from the outer regions is slowly replaced by Li- and Be-poor material flowing up from the inner regions. Meanwhile, turbulent mixing in the thin overshoot layer also replenishes the outer convection zone with Li- and Be-rich material. Overall, the balance between advection by gyroscopic pumping and turbulent mixing by overshooting motions is found to provide a rather good agreement with observations of Li and Be, within a single and very simple framework. This work was funded by an NSF CAREER award of the presenting author.

Escherichia coli K1 Modulates Peroxisome Proliferator–Activated Receptor γ and Glucose Transporter 1 at the Blood-Brain Barrier in Neonatal Meningitis

PubMed Central

Krishnan, Subramanian; Chang, Alexander C.; Stoltz, Brian M.; Prasadarao, Nemani V.

2016-01-01

Escherichia coli K1 meningitis continues to be a major threat to neonatal health. Previous studies demonstrated that outer membrane protein A (OmpA) of E. coli K1 interacts with endothelial cell glycoprotein 96 (Ecgp96) in the blood-brain barrier to enter the central nervous system. Here we show that the interaction between OmpA and Ecgp96 downregulates peroxisome proliferator–activated receptor γ (PPAR-γ) and glucose transporter 1 (GLUT-1) levels in human brain microvascular endothelial cells, causing disruption of barrier integrity and inhibition of glucose uptake. The suppression of PPAR-γ and GLUT-1 by the bacteria in the brain microvessels of newborn mice causes extensive pathophysiology owing to interleukin 6 production. Pretreatment with partial or selective PPAR-γ agonists ameliorate the pathological outcomes of infection by suppressing interleukin 6 production in the brain. Thus, inhibition of PPAR-γ and GLUT-1 by E. coli K1 is a novel pathogenic mechanism in meningitis, and pharmacological upregulation of PPAR-γ and GLUT-1 levels may provide novel therapeutic avenues. PMID:27456707

Vacuum barrier for excimer lasers

DOEpatents

Shurter, R.P.

1992-09-15

A barrier for separating the vacuum area of a diode from the pressurized gas area of an excimer laser. The barrier is a composite material comprising layers of a metal such as copper, along with layers of polyimide, and a matrix of graphite fiber yarns impregnated with epoxy. The barrier is stronger than conventional foil barriers, and allows greater electron throughput. 3 figs.

Hermetic aluminum radio frequency interconnection and method for making

DOEpatents

Kilgo, Riley D.; Kovacic, Larry; Brow, Richard K.

2000-01-01

The present invention provides a light-weight, hermetic coaxial radio-frequency (RF) interconnection having an electrically conductive outer housing made of aluminum or an aluminum alloy, a central electrical conductor made of ferrous or non-ferrous material, and a cylinder of dielectric material comprising a low-melting-temperature, high-thermal-expansion aluminophosphate glass composition for hermetically sealing between the aluminum-alloy outer housing and the ferrous or non-ferrous center conductor. The entire RF interconnection assembly is made permanently hermetic by thermally fusing the center conductor, glass, and housing concurrently by bringing the glass to the melt point by way of exposure to an atmospheric temperature sufficient to melt the glass, less than 540.degree. C., but that does not melt the center conductor or the outer aluminum or aluminum alloy housing. The composition of the glass used is controlled to provide a suitable low dielectric constant so that an appropriate electrical characteristic impedance, for example 50 ohms, can be achieved for an electrical interconnection that performs well at high radio frequencies and also provides an interconnection maintaining a relatively small physical size.

[Shaping ability of two nickel-titanium rotary systems in simulated S-shaped canals].

PubMed

Luo, Hong-xia; Huang, Ding-ming; Zhang, Fu-hua; Tan, Hong; Zhou, Xue-dong

2008-01-01

To evaluate the shaping ability of two nickel-titanium rotary systems (ProTaper and Hero642) in simulated S-shaped canals. Thirty simulated S-shaped canals were randomly divided into three groups and prepared by ProTaper, Hero642, ProTaper combined with Hero642 respectively. All the canals were scanned before and after instrumentation, and the amount of material removed in the inner and outer wall and the canal width after instrumentation were measured with a computer image analysis program. There was significant difference in the amount of material removed at the inner side of apical curvature and outer side of apex between ProTaper combined with Hero642 and ProTaper files (P < 0.05) at the same tip size. The inner and outer wall of the canals were evenly prepared by ProTaper combined with Hero642, and the taper of canals were better than those prepared by Hero642. ProTaper combined with Hero 642 had better shaping ability to maintain the original shape and could create good taper canals in the simulated S-shaped canal model.

Photothermal characterization of encapsulant materials for photovoltaic modules

NASA Technical Reports Server (NTRS)

Liang, R. H.; Gupta, A.; Distefano, S.

1982-01-01

A photothermal test matrix and a low cost testing apparatus for encapsulant materials of photovoltaic modules were defined. Photothermal studies were conducted to screen and rank existing as well as future encapsulant candidate materials and/or material formulations in terms of their long term physiochemical stability under accelerated photothermal aging conditions. Photothermal characterization of six candidate pottant materials and six candidate outer cover materials were carried out. Principal products of photothermal degradation are identified. Certain critical properties are also monitored as a function of photothermal aging.

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

Vinegar, Harold J.; Carter, Ernest E.; Son, Jaime Santos

Methods for forming a barrier around at least a portion of a treatment area in a subsurface formation are described herein. A material including wax may be introduced into one or more wellbores. The material introduced into two or more wells may mix in the formation and congeal to form a barrier to fluid flow.

Comparison of Performance of Experimental and Conventional Cage Designs and Materials for 75-millimeter-bore Cylindrical Roller Bearings at High Speed

NASA Technical Reports Server (NTRS)

Anderson, William J; Macks, E Fred; Nemeth, Zolton N

1954-01-01

The results of two investigations, one to determine the relative merits of four experimental and two conventional design 75-millimeter-bore (size 215) cylindrical roller bearings and one to determine the relative merits of nodular iron and bronze as cage materials for this size and type of bearing, are presented in this report. Nine test bearings were operated over a range of dn values (product of bearing bore in mm and shaft speed in r.p.m) from 0.3 x 10(6) to 2.3 x 20(6), radial loads for 7 to 1613 pounds, and oil flows from 2 to 8 pounds per minute with a single-jet circulatory oil feed. Of the six bearings used to evaluate designs, four were experimental types with outer-race-riding cages and inner-race-guided rollers, and two were conventional types, one with outer-race-guided rollers and cage and one with inner-race-guided rollers and cage. Each of these six test bearings was equipped with a different design cage made of nodular iron. The experimental combination of an outer-race-riding cage with a straight-through outer race and inner-race-guided rollers was found to give the best over-all performance based on limiting dn values and bearing temperatures.

Glove and gown effects on intraoperative bacterial contamination.

PubMed

Ward, William G; Cooper, Joshua M; Lippert, Dylan; Kablawi, Rawan O; Neiberg, Rebecca H; Sherertz, Robert J

2014-03-01

Experiments were performed to determine the risk of bacterial contamination associated with changing outer gloves and using disposable spunlace paper versus reusable cloth gowns. Despite decades of research, there remains a lack of consensus regarding certain aspects of optimal aseptic technique including outer glove exchange while double-gloving and surgical gown type selection. In an initial glove study, 102 surgical team members were randomized to exchange or retain outer gloves 1 hour into clean orthopedic procedures; cultures were obtained 15 minutes later from the palm of the surgeon's dominant gloved hand and from the surgical gown sleeve. Surgical gown type selection was recorded. A laboratory strike-through study investigating bacterial transmission through cloth and paper gowns was performed with coagulase-negative staphylococci. In a follow-up glove study, 251 surgical team members, all wearing paper gowns, were randomized as in the first glove study. Glove study 1 revealed 4-fold higher levels of baseline bacterial contamination (31% vs 7%) on the sleeve of surgical team members wearing cloth gowns than those using paper gowns [odds ratio (95% confidence interval): 4.64 (1.72-12.53); P = 0.0016]. The bacterial strike-through study revealed that 26 of 27 cloth gowns allowed bacterial transmission through the material compared with 0 of 27 paper gowns (P < 0.001). In glove study 2, surgeons retaining outer gloves 1 hour into the case had a subsequent positive glove contamination rate of 23% compared with 13% among surgeons exchanging their original outer glove [odds ratio (95% confidence interval): 1.97 (1.02-3.80); P = 0.0419]. Paper gowns demonstrated less bacterial transmission in the laboratory and lower rates of contamination in the operating room. Disposable paper gowns are recommended for all surgical cases, especially those involving implants, because of the heightened risk of infection. Outer glove exchange just before handling implant materials is also recommended to minimize intraoperative contamination.

NASA Examines Technology To Fold Aircraft Wings In Flight

NASA Image and Video Library

2018-01-17

NASA conducts a flight test series to investigate the ability of an innovative technology to fold the outer portions of wings in flight as part of the Spanwise Adaptive Wing project, or SAW. Flight tests took place at NASA Armstrong Flight Research Center in California, using a subscale UAV called Prototype Technology-Evaluation Research Aircraft, or PTERA, provided by Area-I. NASA Glenn Research Center in Cleveland developed the alloy material, and worked with Boeing Research & Technology to integrate the material into an actuator. The alloy is triggered by temperature to move the outer portions of wings up or down in flight. The ability to fold wings to the ideal position of various flight conditions may produce several aerodynamic benefits for both subsonic and supersonic aircraft.

Electrochemical cells and methods of manufacturing the same

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

Bazzarella, Ricardo; Slocum, Alexander H.; Doherty, Tristan

2016-07-26

Electrochemical cells and methods of making electrochemical cells are described herein. In some embodiments, an apparatus includes a multi-layer sheet for encasing an electrode material for an electrochemical cell. The multi-layer sheet including an outer layer, an intermediate layer that includes a conductive substrate, and an inner layer disposed on a portion of the conductive substrate. The intermediate layer is disposed between the outer layer and the inner layer. The inner layer defines an opening through which a conductive region of the intermediate layer is exposed such that the electrode material can be electrically connected to the conductive region. Thus,more » the intermediate layer can serve as a current collector for the electrochemical cell.« less

FUEL ELEMENT FOR NUCLEAR REACTORS

DOEpatents

Bassett, C.H.

1961-11-21

A fuel element is designed which is particularly adapted for reactors of high power density used to generate steam for the production of electricity. The fuel element consists of inner and outer concentric tubes forming an annular chamber within which is contained fissionable fuel pellet segments, wedge members interposed between the fuel segments, and a spring which, acting with wedge members, urges said fuel pellets radially into contact against the inner surface of the outer tube. The wedge members may be a fertile material convertible into fissionable fuel material by absorbing neutrons emitted from the fissionable fuel pellet segments. The costly grinding of cylindrical fuel pellets to close tolerances for snug engagement is reduced because the need to finish the exact size is eliminated. (AEC)

Chondrulelike objects in short-period comet 81P/Wild 2.

PubMed

Nakamura, Tomoki; Noguchi, Takaaki; Tsuchiyama, Akira; Ushikubo, Takayuki; Kita, Noriko T; Valley, John W; Zolensky, Michael E; Kakazu, Yuki; Sakamoto, Kanako; Mashio, Etsuko; Uesugi, Kentaro; Nakano, Tsukasa

2008-09-19

The Stardust spacecraft returned cometary samples that contain crystalline material, but the origin of the material is not yet well understood. We found four crystalline particles from comet 81P/Wild 2 that were apparently formed by flash-melting at a high temperature and are texturally, mineralogically, and compositionally similar to chondrules. Chondrules are submillimeter particles that dominate chondrites and are believed to have formed in the inner solar nebula. The comet particles show oxygen isotope compositions similar to chondrules in carbonaceous chondrites that compose the middle-to-outer asteroid belt. The presence of the chondrulelike objects in the comet suggests that chondrules have been transported out to the cold outer solar nebula and spread widely over the early solar system.

What Happens during Natural Protein Fibre Dissolution in Ionic Liquids.

PubMed

Chen, Jingyu; Vongsanga, Kylie; Wang, Xungai; Byrne, Nolene

2014-08-28

Here, we monitor the dissolution of several natural protein fibres such as wool, human hair and silk, in various ionic liquids (ILs). The dissolution of protein-based materials using ILs is an emerging area exploring the production of new materials from waste products. Wool is a keratin fibre, which is extensively used in the textiles industry and as a result has considerable amounts of waste produced each year. Wool, along with human hair, has a unique morphology whereby the outer layer, the cuticle, is heavily cross linked with disulphide bonds, whereas silk does not have this outer layer. Here we show how ILs dissolve natural protein fibres and how the mechanism of dissolution is directly related to the structure and morphology of the wool fibre.

Identification of two inner-membrane proteins required for the transport of lipopolysaccharide to the outer membrane of Escherichia coli

PubMed Central

Ruiz, Natividad; Gronenberg, Luisa S.; Kahne, Daniel; Silhavy, Thomas J.

2008-01-01

The outer membrane (OM) of most Gram-negative bacteria contains lipopolysaccharide (LPS) in the outer leaflet. LPS, or endotoxin, is a molecule of important biological activities. In the host, LPS elicits a potent immune response, while in the bacterium, it plays a crucial role by establishing a barrier to limit entry of hydrophobic molecules. Before LPS is assembled at the OM, it must be synthesized at the inner membrane (IM) and transported across the aqueous periplasmic compartment. Much is known about the biosynthesis of LPS but, until recently, little was known about its transport and assembly. We applied a reductionist bioinformatic approach that takes advantage of the small size of the proteome of the Gram-negative endosymbiont Blochmannia floridanus to search for novel factors involved in OM biogenesis. This led to the discovery of two essential Escherichia coli IM proteins of unknown function, YjgP and YjgQ, which are required for the transport of LPS to the cell surface. We propose that these two proteins, which we have renamed LptF and LptG, respectively, are the missing transmembrane components of the ABC transporter that, together with LptB, functions to extract LPS from the IM en route to the OM. PMID:18375759

Identification of two inner-membrane proteins required for the transport of lipopolysaccharide to the outer membrane of Escherichia coli.

PubMed

Ruiz, Natividad; Gronenberg, Luisa S; Kahne, Daniel; Silhavy, Thomas J

2008-04-08

The outer membrane (OM) of most Gram-negative bacteria contains lipopolysaccharide (LPS) in the outer leaflet. LPS, or endotoxin, is a molecule of important biological activities. In the host, LPS elicits a potent immune response, while in the bacterium, it plays a crucial role by establishing a barrier to limit entry of hydrophobic molecules. Before LPS is assembled at the OM, it must be synthesized at the inner membrane (IM) and transported across the aqueous periplasmic compartment. Much is known about the biosynthesis of LPS but, until recently, little was known about its transport and assembly. We applied a reductionist bioinformatic approach that takes advantage of the small size of the proteome of the Gram-negative endosymbiont Blochmannia floridanus to search for novel factors involved in OM biogenesis. This led to the discovery of two essential Escherichia coli IM proteins of unknown function, YjgP and YjgQ, which are required for the transport of LPS to the cell surface. We propose that these two proteins, which we have renamed LptF and LptG, respectively, are the missing transmembrane components of the ABC transporter that, together with LptB, functions to extract LPS from the IM en route to the OM.

Mechanics of a gaseous film barrier to lubricant wetting of elastohydrodynamically lubricated conjunctions

NASA Technical Reports Server (NTRS)

Prahl, J. M.; Hamrock, B. J.

1985-01-01

Two analytical models, one based on simple hydrodynamic lubrication and the other on soft elastohydrodynamic lubrication, are presented and compared to delineate the dominant physical parameters that govern the mechanics of a gaseous film between a small droplet of lubricant and the outer race of a ball bearing. Both models are based on the balance of gravity forces, air drag forces, and air film lubrication forces and incorporate a drag coefficient C sub D and a lubrication coefficient C sub L to be determined from experiment. The soft elastohydrodynamic lubrication (EHL) model considers the effects of droplet deformation and solid-surface geometry; the simpler hydrodynamic lubrication (HL) model assumes that the droplet remains essentially spherical. The droplet's angular position depended primarily on the ratio of gas inertia to droplet gravity forces and on the gas Reynolds number and weakly on the ratio of droplet gravity forces to surface tension forces (Bond number) and geometric ratios for the soft EHL. An experimental configuration in which an oil droplet is supported by an air film on the rotating outer race of a ball bearing within a pressure-controlled chamber produced measurements of droplet angular position as a function of outer-race velocity droplet size and type, and chamber pressure.

Classical and alternative complement activation on photoreceptor outer segments drives monocyte-dependent retinal atrophy.

PubMed

Katschke, Kenneth J; Xi, Hongkang; Cox, Christian; Truong, Tom; Malato, Yann; Lee, Wyne P; McKenzie, Brent; Arceo, Rommel; Tao, Jianhua; Rangell, Linda; Reichelt, Mike; Diehl, Lauri; Elstrott, Justin; Weimer, Robby M; Campagne, Menno van Lookeren

2018-05-09

Geographic atrophy (GA), the advanced form of dry age-related macular degeneration (AMD), is characterized by progressive loss of retinal pigment epithelium cells and photoreceptors in the setting of characteristic extracellular deposits and remains a serious unmet medical need. While genetic predisposition to AMD is dominated by polymorphisms in complement genes, it remains unclear how complement activation contributes to retinal atrophy. Here we demonstrate that complement is activated on photoreceptor outer segments (POS) in the retina peripheral to atrophic lesions associated with GA. When exposed to human serum following outer blood-retinal barrier breakdown, POS act as potent activators of the classical and alternative complement pathway. In mouse models of retinal degeneration, classical and alternative pathway complement activation on photoreceptors contributed to the loss of photoreceptor function. This was dependent on C5a-mediated recruitment of peripheral blood monocytes but independent of resident microglia. Genetic or pharmacologic inhibition of both classical and alternative complement C3 and C5 convertases was required to reduce progressive degeneration of photoreceptor rods and cones. Our study implicates systemic classical and alternative complement proteins and peripheral blood monocytes as critical effectors of localized retinal degeneration with potential relevance for the contribution of complement activation to GA.

A Peptidomimetic Antibiotic Targets Outer Membrane Proteins and Disrupts Selectively the Outer Membrane in Escherichia coli*

PubMed Central

Urfer, Matthias; Bogdanovic, Jasmina; Lo Monte, Fabio; Moehle, Kerstin; Zerbe, Katja; Omasits, Ulrich; Ahrens, Christian H.; Pessi, Gabriella; Eberl, Leo; Robinson, John A.

2016-01-01

Increasing antibacterial resistance presents a major challenge in antibiotic discovery. One attractive target in Gram-negative bacteria is the unique asymmetric outer membrane (OM), which acts as a permeability barrier that protects the cell from external stresses, such as the presence of antibiotics. We describe a novel β-hairpin macrocyclic peptide JB-95 with potent antimicrobial activity against Escherichia coli. This peptide exhibits no cellular lytic activity, but electron microscopy and fluorescence studies reveal an ability to selectively disrupt the OM but not the inner membrane of E. coli. The selective targeting of the OM probably occurs through interactions of JB-95 with selected β-barrel OM proteins, including BamA and LptD as shown by photolabeling experiments. Membrane proteomic studies reveal rapid depletion of many β-barrel OM proteins from JB-95-treated E. coli, consistent with induction of a membrane stress response and/or direct inhibition of the Bam folding machine. The results suggest that lethal disruption of the OM by JB-95 occurs through a novel mechanism of action at key interaction sites within clusters of β-barrel proteins in the OM. These findings open new avenues for developing antibiotics that specifically target β-barrel proteins and the integrity of the Gram-negative OM. PMID:26627837

Asymmetric phospholipid: lipopolysaccharide bilayers; a Gram-negative bacterial outer membrane mimic

PubMed Central

Clifton, Luke A.; Skoda, Maximilian W. A.; Daulton, Emma L.; Hughes, Arwel V.; Le Brun, Anton P.; Lakey, Jeremy H.; Holt, Stephen A.

2013-01-01

The Gram-negative bacterial outer membrane (OM) is a complex and highly asymmetric biological barrier but the small size of bacteria has hindered advances in in vivo examination of membrane dynamics. Thus, model OMs, amenable to physical study, are important sources of data. Here, we present data from asymmetric bilayers which emulate the OM and are formed by a simple two-step approach. The bilayers were deposited on an SiO2 surface by Langmuir–Blodgett deposition of phosphatidylcholine as the inner leaflet and, via Langmuir–Schaefer deposition, an outer leaflet of either Lipid A or Escherichia coli rough lipopolysaccharides (LPS). The membranes were examined using neutron reflectometry (NR) to examine the coverage and mixing of lipids between the bilayer leaflets. NR data showed that in all cases, the initial deposition asymmetry was mostly maintained for more than 16 h. This stability enabled the sizes of the headgroups and bilayer roughness of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and Lipid A, Rc-LPS and Ra-LPS to be clearly resolved. The results show that rough LPS can be manipulated like phospholipids and used to fabricate advanced asymmetric bacterial membrane models using well-known bilayer deposition techniques. Such models will enable OM dynamics and interactions to be studied under in vivo-like conditions. PMID:24132206

Radiation Insulation

NASA Technical Reports Server (NTRS)

1993-01-01

An aluminized polymer film is a highly effective radiation barrier for both manned and unmanned spacecraft. Variations of this space-devised material are also used as an energy conservation technique for homes and offices. One commercial company, Tech 2000 (formerly Buckeye Radiant Barrier), markets 'Super R' Radiant Barrier, which finds its origins in the Apollo Mission programs. The material is placed between wall studs and exterior facing before siding or in new roof installation, between roof support and roof sheathing. Successful retrofit installations have included schools and shrink wrap ovens. The radiant barrier blocks 95 percent of radiant energy, thus retaining summer heat and blocking winter cold. Suppliers claim utility bill reductions of 20 percent or more.

P-Compensated and P-Doped Superlattice Infrared Detectors

NASA Technical Reports Server (NTRS)

Khoshakhlagh, Arezou (Inventor); Ting, David Z. (Inventor); Gunapala, Sarath D. (Inventor)

2017-01-01

Barrier infrared detectors configured to operate in the long-wave (LW) infrared regime are provided. The barrier infrared detector systems may be configured as pin, pbp, barrier and double heterostructrure infrared detectors incorporating optimized p-doped absorbers capable of taking advantage of high mobility (electron) minority carriers. The absorber may be a p-doped Ga-free InAs/InAsSb material. The p-doping may be accomplished by optimizing the Be doping levels used in the absorber material. The barrier infrared detectors may incorporate individual superlattice layers having narrower periodicity and optimization of Sb composition to achieve cutoff wavelengths of.about.10.mu.m.

Membrane organization determines barrier properties of endothelial cells and short-chain sphingolipid-facilitated doxorubicin influx.

PubMed

van Hell, A J; Klymchenko, A; Gueth, D M; van Blitterswijk, W J; Koning, G A; Verheij, M

2014-09-01

The endothelial lining and its outer lipid membrane are the first major barriers drug molecules encounter upon intravenous administration. Our previous work identified lipid analogs that counteract plasma membrane barrier function for a series of amphiphilic drugs. For example, short-chain sphingolipids (SCS), like N-octanoyl-glucosylceramide, effectively elevated doxorubicin accumulation in tumor cells, both in vitro and in vivo, and in endothelial cells, whereas other (normal) cells remained unaffected. We hypothesize here that local membrane lipid composition and the degree of lipid ordering define SCS efficacy in individual cells. To this end, we study the differential effect of SCS on bovine aortic endothelial cells (BAEC) in its confluent versus proliferative state, as a model system. While their (plasma membrane) lipidome stays remarkably unaltered when BAECs reach confluency, their lipids segregate to form apical and basolateral domains. Using probe NR12S, we reveal that lipids in the apical membrane are more condensed/liquid-ordered. SCS preferentially attenuate the barrier posed by these condensed membranes and facilitate doxorubicin influx in these particular membrane regions. We confirm these findings in MDCK cells and artificial membranes. In conclusion, SCS-facilitated drug traversal acts on condensed membrane domains, elicited by confluency in resting endothelium. Copyright © 2014 Elsevier B.V. All rights reserved.

Corrosion and runoff rates of Cu and three Cu-alloys in marine environments with increasing chloride deposition rate.

PubMed

Odnevall Wallinder, Inger; Zhang, Xian; Goidanich, Sara; Le Bozec, Nathalie; Herting, Gunilla; Leygraf, Christofer

2014-02-15

Bare copper sheet and three commercial Cu-based alloys, Cu15Zn, Cu4Sn and Cu5Al5Zn, have been exposed to four test sites in Brest, France, with strongly varying chloride deposition rates. The corrosion rates of all four materials decrease continuously with distance from the coast, i.e. with decreasing chloride load, and in the following order: Cu4Sn>Cu sheet>Cu15Zn>Cu5Al5Zn. The patina on all materials was composed of two main layers, Cu2O as the inner layer and Cu2(OH)3Cl as the outer layer, and with a discontinuous presence of CuCl in between. Additional minor patina constituents are SnO2 (Cu4Sn), Zn5(OH)6(CO3)2 (Cu15Zn and Cu5Al5Zn) and Zn6Al2(OH)16CO3·4H2O/Zn2Al(OH)6Cl·2H2O/Zn5Cl2(OH)8·H2O and Al2O3 (Cu5Al5Zn). The observed Zn- and Zn/Al-containing corrosion products might be important factors for the lower sensitivity of Cu15Zn and Cu5Al5Zn against chloride-induced atmospheric corrosion compared with Cu sheet and Cu4Sn. Decreasing corrosion rates with exposure time were observed for all materials and chloride loads and attributed to an improved adherence with time of the outer patina to the underlying inner oxide. Flaking of the outer patina layer was mainly observed on Cu4Sn and Cu sheet and associated with the gradual transformation of CuCl to Cu2(OH)3Cl of larger volume. After three years only Cu5Al5Zn remains lustrous because of a patina compared with the other materials that appeared brownish-reddish. Significantly lower release rates of metals compared with corresponding corrosion rates were observed for all materials. Very similar release rates of copper from all four materials were observed during the fifth year of marine exposure due to an outer surface patina that with time revealed similar constituents and solubility properties. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Sandwich-Architectured Poly(lactic acid)-Graphene Composite Food Packaging Films.

PubMed

Goh, Kunli; Heising, Jenneke K; Yuan, Yang; Karahan, Huseyin E; Wei, Li; Zhai, Shengli; Koh, Jia-Xuan; Htin, Nanda M; Zhang, Feimo; Wang, Rong; Fane, Anthony G; Dekker, Matthijs; Dehghani, Fariba; Chen, Yuan

2016-04-20

Biodegradable food packaging promises a more sustainable future. Among the many different biopolymers used, poly(lactic acid) (PLA) possesses the good mechanical property and cost-effectiveness necessary of a biodegradable food packaging. However, PLA food packaging suffers from poor water vapor and oxygen barrier properties compared to many petroleum-derived ones. A key challenge is, therefore, to simultaneously enhance both the water vapor and oxygen barrier properties of the PLA food packaging. To address this issue, we design a sandwich-architectured PLA-graphene composite film, which utilizes an impermeable reduced graphene oxide (rGO) as the core barrier and commercial PLA films as the outer protective encapsulation. The synergy between the barrier and the protective encapsulation results in a significant 87.6% reduction in the water vapor permeability. At the same time, the oxygen permeability is reduced by two orders of magnitude when evaluated under both dry and humid conditions. The excellent barrier properties can be attributed to the compact lamellar microstructure and the hydrophobicity of the rGO core barrier. Mechanistic analysis shows that the large rGO lateral dimension and the small interlayer spacing between the rGO sheets have created an extensive and tortuous diffusion pathway, which is up to 1450-times the thickness of the rGO barrier. In addition, the sandwiched architecture has imbued the PLA-rGO composite film with good processability, which increases the manageability of the film and its competency to be tailored. Simulations using the PLA-rGO composite food packaging film for edible oil and potato chips also exhibit at least eight-fold extension in the shelf life of these oxygen and moisture sensitive food products. Overall, these qualities have demonstrated the high potential of a sandwich-architectured PLA-graphene composite film for food packaging applications.

49 CFR 173.6 - Materials of trade exceptions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... SHIPMENTS AND PACKAGINGS General § 173.6 Materials of trade exceptions. When transported by motor vehicle in... solids, liquids, and sharps, the outer packaging must be a strong, tight packaging securely closed and...) Packagings must be leak tight for liquids and gases, sift proof for solids, and be securely closed, secured...

49 CFR 173.6 - Materials of trade exceptions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... SHIPMENTS AND PACKAGINGS General § 173.6 Materials of trade exceptions. When transported by motor vehicle in... solids, liquids, and sharps, the outer packaging must be a strong, tight packaging securely closed and...) Packagings must be leak tight for liquids and gases, sift proof for solids, and be securely closed, secured...

49 CFR 173.6 - Materials of trade exceptions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... SHIPMENTS AND PACKAGINGS General § 173.6 Materials of trade exceptions. When transported by motor vehicle in... outer packaging must be securely closed to prevent leaks or punctures. For solids, liquids, and sharps...) Packaging. (1) Packagings must be leak tight for liquids and gases, sift proof for solids, and be securely...

49 CFR 173.6 - Materials of trade exceptions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... SHIPMENTS AND PACKAGINGS General § 173.6 Materials of trade exceptions. When transported by motor vehicle in... solids, liquids, and sharps, the outer packaging must be a strong, tight packaging securely closed and...) Packagings must be leak tight for liquids and gases, sift proof for solids, and be securely closed, secured...

Highway noise reduction barriers : a literature review.

DOT National Transportation Integrated Search

1973-01-01

This report describes the various parameters that must be considered in evaluating highway noise barriers. The information presented is based on the current state of the art and covers the effectiveness, designs, materials and costs of barriers.

Cuprous selenide and sulfide form improved photovoltaic barriers

NASA Technical Reports Server (NTRS)

1966-01-01

Photovoltaic barriers formed by depositing a layer of polycrystalline cuprous sulfide or cuprous selenide on gallium arsenide are chemically and electrically stable. The stability of these barrier materials is significantly greater than that of cuprous iodide.

Physical barrier to reduce WP mortalities of foraging waterfowl

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

Pochop, P.A.; Cummings, J.L.; Yoder, C.A.

White phosphorus (WP) has been identified as the cause of mortality to certain species of water-fowl at Eagle River Flats, a tidal marsh in Alaska, used as an ordinance impact area by the US Army. A blend of calcium bentonite/organo clays, gravel, and binding polymers was tested for effectiveness as a barrier to reduce duck foraging and mortality. Following the application of the barrier to one of two contaminated ponds, the authors observed greater duck foraging and higher mortality in the untreated pond and no mortality in the treated pond after a year of tidal inundations and ice effects. Emergentmore » vegetation recovered within a year of treatment. WP levels in the barrier were less than the method limit of detection, indicating no migration of WP into the materials. Barrier thickness remained relatively stable over a period of 4 years, and vegetation was found to be important in stabilizing the barrier material.« less

Organic materials in planetary and protoplanetary systems: nature or nurture?

NASA Astrophysics Data System (ADS)

Dalle Ore, C. M.; Fulchignoni, M.; Cruikshank, D. P.; Barucci, M. A.; Brunetto, R.; Campins, H.; de Bergh, C.; Debes, J. H.; Dotto, E.; Emery, J. P.; Grundy, W. M.; Jones, A. P.; Mennella, V.; Orthous-Daunay, F. R.; Owen, T.; Pascucci, I.; Pendleton, Y. J.; Pinilla-Alonso, N.; Quirico, E.; Strazzulla, G.

2011-09-01

Aims: The objective of this work is to summarize the discussion of a workshop aimed at investigating the properties, origins, and evolution of the materials that are responsible for the red coloration of the small objects in the outer parts of the solar system. Because of limitations or inconsistencies in the observations and, until recently, the limited availability of laboratory data, there are still many questions on the subject. Our goal is to approach two of the main questions in a systematic way: - Is coloring an original signature of materials that are presolar in origin ("nature") or stems from post-formational chemical alteration, or weathering ("nurture")? - What is the chemical signature of the material that causes spectra to be sloped towards the red in the visible? We examine evidence available both from the laboratory and from observations sampling different parts of the solar system and circumstellar regions (disks). Methods: We present a compilation of brief summaries gathered during the workshop and describe the evidence towards a primordial vs. evolutionary origin for the material that reddens the small objects in the outer parts of our, as well as in other, planetary systems. We proceed by first summarizing laboratory results followed by observational data collected at various distances from the Sun. Results: While laboratory experiments show clear evidence of irradiation effects, particularly from ion bombardment, the first obstacle often resides in the ability to unequivocally identify the organic material in the observations. The lack of extended spectral data of good quality and resolution is at the base of this problem. Furthermore, that both mechanisms, weathering and presolar, act on the icy materials in a spectroscopically indistinguishable way makes our goal of defining the impact of each mechanism challenging. Conclusions: Through a review of some of the workshop presentations and discussions, encompassing laboratory experiments as well as observational data, we infer that both "nature" and "nurture" are instrumental in the coloration of small objects in the outer parts

HST Multi Layer Insulation Failure Review Board Findings

NASA Technical Reports Server (NTRS)

Townsend, Jacqueline; Hansen, Patricia

1998-01-01

The mechanical and optical properties of the thermal control materials on the Hubble Space Telescope (HST) have degraded over the nearly seven years the telescope has been in orbit. Astronaut observations and photographs from the Second Servicing Mission (SM2) revealed large cracks in the metallized Teflon fluorinated ethylene propylene (FEP), the outer layer of the multi-layer insulation (MLI), in many locations around the telescope. Also, the absorptance of the bonded metallized Teflon FEP radiator surfaces of the telescope has increased over time. A Failure Review Board was established to determine the damage mechanism and to identify a replacement material. Samples of the top layer of the MLI and radiator material were retrieved during SM2, and a thorough investigation into the degradation followed in order to determine the primary cause of the damage. Mapping of the cracks on HST and the ground testing showed that thermal cycling with deep-layer damage from electron and proton radiation are necessary to cause the observed embrittlement. Further, strong evidence was found indicating that chain scission (reduced molecular weight) is the dominant form of damage to the metallized Teflon FEP. Given the damage to the outer layer of the multi-layer insulation (MLI) that was apparent during the second servicing mission (SM2), the decision was made to replace the outer layer during subsequent servicing missions. The replacement material had to meet the stringent thermal requirements of the spacecraft and maintain structural integrity for at least ten years. Ten candidate materials were exposed to simulated orbital environments and a replacement material was selected. This presentation will summarize the FRB results, in particular, the analysis of the retrieved specimens, the results of the simulated environmental exposures, and the selection of the replacement material. The NASA Space Environments and Effects community needs to hear these results because they reveal that Teflon (FEP) films should not be used in LEO as routinely as they are today.

IPE : EVALUATION OF ORTHOTROPIC ELASTIC PROPERTIES AND ITS APPLICATION IN ROADSIDE BARRIERS

DOT National Transportation Integrated Search

2017-12-24

Roadside barriers are the primary structural safety devices on surface roads. They can be made from any material as long as they can absorb the energy involved in an impact scenario. One material that has that potential is Ipe, which is a hardwood ma...

SPATIAL DISTRIBUTION OF CARBON AND SULFUR PRECIPITATING WITHIN PERMEABLE REACTIVE BARRIERS: DEVELOPMENT OF ANALYTICAL METHODS

EPA Science Inventory

A permeable reactive barrier (PRB) is a wall of porous reactive material placed in the path of a dissolved contaminant plume for the purpose of removing contaminants from ground water. Chemical processes within these reactive materials remove both inorganic and organic contamina...

Evaluation of critical current density and residual resistance ratio limits in powder in tube Nb 3Sn conductors

DOE PAGES

Segal, Christopher; Tarantini, Chiara; Sung, Zu Hawn; ...

2016-06-10

High critical current density (Jc) Nb 3Sn A15 multifilamentary wires require a large volume fraction of small grain, superconducting A15 phase, as well as Cu stabilizer with high Residual Resistance Ratio (RRR) to provide electromagnetic stabilization and protection. In Powder-in-Tube (PIT) wires the unreacted Nb7.5wt.%Ta outer layer of the tubular filaments acts as a diffusion barrier and protects the interfilamentary Cu stabilizer from Sn contamination. A high RRR requirement generally imposes a restricted A15 reaction heat treatment (HT) to prevent localized full reaction of the filament that could allow Sn to reach the Cu. In this paper we investigate recentmore » high quality PIT wires that achieve a J c(12 T, 4.2 K) up to ~2500 A/mm -2 and find that the minimum diffusion barrier thickness decreases as the filament aspect ratio increases from ~1 in the inner rings of filaments to 1.3 in the outer filament rings. We found that just 2-3 diffusion barrier breaches can degrade RRR from 300 to 150 or less. Using progressive etching of the Cu we also found that the RRR degradation is localized near the external filaments where deformation is highest. Consequently minimizing filament distortion during strand fabrication is important for reducing RRR degradation. The additional challenge of developing the highest possible J c must be addressed by forming the maximum fraction of high J c small-grain (SG) A15 and minimizing low J c large-grain (LG) A15 morphologies. Finally, in one wire we found that 15% of the filaments had a significantly enhanced SG/LG A15 ratio and no residual A15 in the core, a feature that opens a path to substantial J c improvement.« less